Linux Networking and Network Devices APIs¶
Linux Networking¶
Networking Base Types¶
-
enum
sock_type¶ Socket types
Constants
SOCK_STREAM- stream (connection) socket
SOCK_DGRAM- datagram (conn.less) socket
SOCK_RAW- raw socket
SOCK_RDM- reliably-delivered message
SOCK_SEQPACKET- sequential packet socket
SOCK_DCCP- Datagram Congestion Control Protocol socket
SOCK_PACKET- linux specific way of getting packets at the dev level. For writing rarp and other similar things on the user level.
Description
When adding some new socket type please grep ARCH_HAS_SOCKET_TYPE include/asm-* /socket.h, at least MIPS overrides this enum for binary compat reasons.
-
enum
sock_shutdown_cmd¶ Shutdown types
Constants
SHUT_RD- shutdown receptions
SHUT_WR- shutdown transmissions
SHUT_RDWR- shutdown receptions/transmissions
-
struct
socket¶ general BSD socket
Definition
struct socket {
socket_state state;
short type;
unsigned long flags;
struct file *file;
struct sock *sk;
const struct proto_ops *ops;
struct socket_wq wq;
};
Members
state- socket state (
SS_CONNECTED, etc) type- socket type (
SOCK_STREAM, etc) flags- socket flags (
SOCK_NOSPACE, etc) file- File back pointer for gc
sk- internal networking protocol agnostic socket representation
ops- protocol specific socket operations
wq- wait queue for several uses
Socket Buffer Functions¶
-
unsigned int
skb_frag_size(const skb_frag_t * frag)¶ Returns the size of a skb fragment
Parameters
const skb_frag_t * frag- skb fragment
-
void
skb_frag_size_set(skb_frag_t * frag, unsigned int size)¶ Sets the size of a skb fragment
Parameters
skb_frag_t * frag- skb fragment
unsigned int size- size of fragment
-
void
skb_frag_size_add(skb_frag_t * frag, int delta)¶ Incrementes the size of a skb fragment by
delta
Parameters
skb_frag_t * frag- skb fragment
int delta- value to add
-
void
skb_frag_size_sub(skb_frag_t * frag, int delta)¶ Decrements the size of a skb fragment by
delta
Parameters
skb_frag_t * frag- skb fragment
int delta- value to subtract
-
bool
skb_frag_must_loop(struct page * p)¶ Test if
pis a high memory page
Parameters
struct page * p- fragment’s page
-
skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied)¶ loop over pages in a fragment
Parameters
f- skb frag to operate on
f_off- offset from start of f->page.p
f_len- length from f_off to loop over
p- (temp var) current page
p_off- (temp var) offset from start of current page, non-zero only on first page.
p_len- (temp var) length in current page, < PAGE_SIZE only on first and last page.
copied- (temp var) length so far, excluding current p_len.
Description
A fragment can hold a compound page, in which case per-page operations, notably kmap_atomic, must be called for each regular page.
hardware time stamps
Definition
struct skb_shared_hwtstamps {
ktime_t hwtstamp;
};
Members
hwtstamp- hardware time stamp transformed into duration since arbitrary point in time
Description
Software time stamps generated by ktime_get_real() are stored in
skb->tstamp.
hwtstamps can only be compared against other hwtstamps from the same device.
This structure is attached to packets as part of the
skb_shared_info. Use skb_hwtstamps() to get a pointer.
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struct
sk_buff¶ socket buffer
Definition
struct sk_buff {
union {
struct {
struct sk_buff *next;
struct sk_buff *prev;
union {
struct net_device *dev;
unsigned long dev_scratch;
};
};
struct rb_node rbnode;
struct list_head list;
};
union {
struct sock *sk;
int ip_defrag_offset;
};
union {
ktime_t tstamp;
u64 skb_mstamp_ns;
};
char cb[48];
union {
struct {
unsigned long _skb_refdst;
void (*destructor)(struct sk_buff *skb);
};
struct list_head tcp_tsorted_anchor;
};
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE);
unsigned long _nfct;
#endif;
unsigned int len, data_len;
__u16 mac_len, hdr_len;
__u16 queue_mapping;
#ifdef __BIG_ENDIAN_BITFIELD;
#define CLONED_MASK (1 << 7);
#else;
#define CLONED_MASK 1;
#endif;
#define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset);
__u8 __cloned_offset[0];
__u8 cloned:1,nohdr:1,fclone:2,peeked:1,head_frag:1, pfmemalloc:1;
#ifdef CONFIG_SKB_EXTENSIONS;
__u8 active_extensions;
#endif;
#ifdef __BIG_ENDIAN_BITFIELD;
#define PKT_TYPE_MAX (7 << 5);
#else;
#define PKT_TYPE_MAX 7;
#endif;
#define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset);
__u8 __pkt_type_offset[0];
__u8 pkt_type:3;
__u8 ignore_df:1;
__u8 nf_trace:1;
__u8 ip_summed:2;
__u8 ooo_okay:1;
__u8 l4_hash:1;
__u8 sw_hash:1;
__u8 wifi_acked_valid:1;
__u8 wifi_acked:1;
__u8 no_fcs:1;
__u8 encapsulation:1;
__u8 encap_hdr_csum:1;
__u8 csum_valid:1;
#ifdef __BIG_ENDIAN_BITFIELD;
#define PKT_VLAN_PRESENT_BIT 7;
#else;
#define PKT_VLAN_PRESENT_BIT 0;
#endif;
#define PKT_VLAN_PRESENT_OFFSET() offsetof(struct sk_buff, __pkt_vlan_present_offset);
__u8 __pkt_vlan_present_offset[0];
__u8 vlan_present:1;
__u8 csum_complete_sw:1;
__u8 csum_level:2;
__u8 csum_not_inet:1;
__u8 dst_pending_confirm:1;
#ifdef CONFIG_IPV6_NDISC_NODETYPE;
__u8 ndisc_nodetype:2;
#endif;
__u8 ipvs_property:1;
__u8 inner_protocol_type:1;
__u8 remcsum_offload:1;
#ifdef CONFIG_NET_SWITCHDEV;
__u8 offload_fwd_mark:1;
__u8 offload_l3_fwd_mark:1;
#endif;
#ifdef CONFIG_NET_CLS_ACT;
__u8 tc_skip_classify:1;
__u8 tc_at_ingress:1;
__u8 tc_redirected:1;
__u8 tc_from_ingress:1;
#endif;
#ifdef CONFIG_TLS_DEVICE;
__u8 decrypted:1;
#endif;
#ifdef CONFIG_NET_SCHED;
__u16 tc_index;
#endif;
union {
__wsum csum;
struct {
__u16 csum_start;
__u16 csum_offset;
};
};
__u32 priority;
int skb_iif;
__u32 hash;
__be16 vlan_proto;
__u16 vlan_tci;
#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS);
union {
unsigned int napi_id;
unsigned int sender_cpu;
};
#endif;
#ifdef CONFIG_NETWORK_SECMARK;
__u32 secmark;
#endif;
union {
__u32 mark;
__u32 reserved_tailroom;
};
union {
__be16 inner_protocol;
__u8 inner_ipproto;
};
__u16 inner_transport_header;
__u16 inner_network_header;
__u16 inner_mac_header;
__be16 protocol;
__u16 transport_header;
__u16 network_header;
__u16 mac_header;
sk_buff_data_t tail;
sk_buff_data_t end;
unsigned char *head, *data;
unsigned int truesize;
refcount_t users;
#ifdef CONFIG_SKB_EXTENSIONS;
struct skb_ext *extensions;
#endif;
};
Members
{unnamed_union}- anonymous
{unnamed_struct}- anonymous
next- Next buffer in list
prev- Previous buffer in list
{unnamed_union}- anonymous
dev- Device we arrived on/are leaving by
rbnode- RB tree node, alternative to next/prev for netem/tcp
{unnamed_union}- anonymous
sk- Socket we are owned by
{unnamed_union}- anonymous
tstamp- Time we arrived/left
cb- Control buffer. Free for use by every layer. Put private vars here
{unnamed_union}- anonymous
{unnamed_struct}- anonymous
_skb_refdst- destination entry (with norefcount bit)
destructor- Destruct function
tcp_tsorted_anchor- list structure for TCP (tp->tsorted_sent_queue)
_nfct- Associated connection, if any (with nfctinfo bits)
len- Length of actual data
data_len- Data length
mac_len- Length of link layer header
hdr_len- writable header length of cloned skb
queue_mapping- Queue mapping for multiqueue devices
cloned- Head may be cloned (check refcnt to be sure)
nohdr- Payload reference only, must not modify header
fclone- skbuff clone status
peeked- this packet has been seen already, so stats have been done for it, don’t do them again
pfmemalloc- skbuff was allocated from PFMEMALLOC reserves
active_extensions- active extensions (skb_ext_id types)
pkt_type- Packet class
ignore_df- allow local fragmentation
nf_trace- netfilter packet trace flag
ip_summed- Driver fed us an IP checksum
ooo_okay- allow the mapping of a socket to a queue to be changed
l4_hash- indicate hash is a canonical 4-tuple hash over transport ports.
sw_hash- indicates hash was computed in software stack
wifi_acked_valid- wifi_acked was set
wifi_acked- whether frame was acked on wifi or not
no_fcs- Request NIC to treat last 4 bytes as Ethernet FCS
csum_not_inet- use CRC32c to resolve CHECKSUM_PARTIAL
dst_pending_confirm- need to confirm neighbour
ndisc_nodetype- router type (from link layer)
ipvs_property- skbuff is owned by ipvs
offload_fwd_mark- Packet was L2-forwarded in hardware
offload_l3_fwd_mark- Packet was L3-forwarded in hardware
tc_skip_classify- do not classify packet. set by IFB device
tc_at_ingress- used within tc_classify to distinguish in/egress
tc_redirected- packet was redirected by a tc action
tc_from_ingress- if tc_redirected, tc_at_ingress at time of redirect
decrypted- Decrypted SKB
tc_index- Traffic control index
{unnamed_union}- anonymous
csum- Checksum (must include start/offset pair)
{unnamed_struct}- anonymous
csum_start- Offset from skb->head where checksumming should start
csum_offset- Offset from csum_start where checksum should be stored
priority- Packet queueing priority
skb_iif- ifindex of device we arrived on
hash- the packet hash
vlan_proto- vlan encapsulation protocol
vlan_tci- vlan tag control information
{unnamed_union}- anonymous
napi_id- id of the NAPI struct this skb came from
secmark- security marking
{unnamed_union}- anonymous
mark- Generic packet mark
{unnamed_union}- anonymous
inner_protocol- Protocol (encapsulation)
inner_transport_header- Inner transport layer header (encapsulation)
inner_network_header- Network layer header (encapsulation)
inner_mac_header- Link layer header (encapsulation)
protocol- Packet protocol from driver
transport_header- Transport layer header
network_header- Network layer header
mac_header- Link layer header
tail- Tail pointer
end- End pointer
head- Head of buffer
data- Data head pointer
truesize- Buffer size
users- User count - see {datagram,tcp}.c
extensions- allocated extensions, valid if active_extensions is nonzero
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bool
skb_pfmemalloc(const struct sk_buff * skb)¶ Test if the skb was allocated from PFMEMALLOC reserves
Parameters
const struct sk_buff * skb- buffer
Parameters
const struct sk_buff * skb- buffer
Description
Returns skb dst_entry, regardless of reference taken or not.
Parameters
struct sk_buff * skb- buffer
struct dst_entry * dst- dst entry
Description
Sets skb dst, assuming a reference was taken on dst and should be released by skb_dst_drop()
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void
skb_dst_set_noref(struct sk_buff * skb, struct dst_entry * dst)¶ sets skb dst, hopefully, without taking reference
Parameters
struct sk_buff * skb- buffer
struct dst_entry * dst- dst entry
Description
Sets skb dst, assuming a reference was not taken on dst. If dst entry is cached, we do not take reference and dst_release will be avoided by refdst_drop. If dst entry is not cached, we take reference, so that last dst_release can destroy the dst immediately.
Parameters
const struct sk_buff * skb- buffer
Parameters
const struct sk_buff * skb- buffer
Parameters
const struct sk_buff * skb- buffer
Parameters
struct sk_buff * skb- buffer
Description
Returns true if we can free the skb.
Parameters
unsigned int size- size to allocate
gfp_t priority- allocation mask
Description
This function is a convenient wrapper around __alloc_skb().
Parameters
const struct sock * sk- socket
const struct sk_buff * skb- buffer
Description
Returns true if skb is a fast clone, and its clone is not freed.
Some drivers call skb_orphan() in their ndo_start_xmit(),
so we also check that this didnt happen.
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struct sk_buff *
alloc_skb_fclone(unsigned int size, gfp_t priority)¶ allocate a network buffer from fclone cache
Parameters
unsigned int size- size to allocate
gfp_t priority- allocation mask
Description
This function is a convenient wrapper around __alloc_skb().
Parameters
struct sk_buff * skb- buffer to pad
int pad- space to pad
Description
Ensure that a buffer is followed by a padding area that is zero filled. Used by network drivers which may DMA or transfer data beyond the buffer end onto the wire.
May return error in out of memory cases. The skb is freed on error.
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int
skb_queue_empty(const struct sk_buff_head * list)¶ check if a queue is empty
Parameters
const struct sk_buff_head * list- queue head
Description
Returns true if the queue is empty, false otherwise.
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bool
skb_queue_is_last(const struct sk_buff_head * list, const struct sk_buff * skb)¶ check if skb is the last entry in the queue
Parameters
const struct sk_buff_head * list- queue head
const struct sk_buff * skb- buffer
Description
Returns true if skb is the last buffer on the list.
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bool
skb_queue_is_first(const struct sk_buff_head * list, const struct sk_buff * skb)¶ check if skb is the first entry in the queue
Parameters
const struct sk_buff_head * list- queue head
const struct sk_buff * skb- buffer
Description
Returns true if skb is the first buffer on the list.
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struct sk_buff *
skb_queue_next(const struct sk_buff_head * list, const struct sk_buff * skb)¶ return the next packet in the queue
Parameters
const struct sk_buff_head * list- queue head
const struct sk_buff * skb- current buffer
Description
Return the next packet in list after skb. It is only valid to call this ifskb_queue_is_last()evaluates to false.
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struct sk_buff *
skb_queue_prev(const struct sk_buff_head * list, const struct sk_buff * skb)¶ return the prev packet in the queue
Parameters
const struct sk_buff_head * list- queue head
const struct sk_buff * skb- current buffer
Description
Return the prev packet in list before skb. It is only valid to call this ifskb_queue_is_first()evaluates to false.
Parameters
struct sk_buff * skb- buffer to reference
Description
Makes another reference to a socket buffer and returns a pointer to the buffer.
Parameters
const struct sk_buff * skb- buffer to check
Description
Returns true if the buffer was generated withskb_clone()and is one of multiple shared copies of the buffer. Cloned buffers are shared data so must not be written to under normal circumstances.
Parameters
const struct sk_buff * skb- buffer to check
Description
Returns true if modifying the header part of the buffer requires the data to be copied.
Parameters
struct sk_buff * skb- buffer to operate on
is the buffer shared
Parameters
const struct sk_buff * skb- buffer to check
Description
Returns true if more than one person has a reference to this buffer.
check if buffer is shared and if so clone it
Parameters
struct sk_buff * skb- buffer to check
gfp_t pri- priority for memory allocation
Description
If the buffer is shared the buffer is cloned and the old copy drops a reference. A new clone with a single reference is returned. If the buffer is not shared the original buffer is returned. When being called from interrupt status or with spinlocks held pri must be GFP_ATOMIC.
NULL is returned on a memory allocation failure.
make a copy of a shared buffer
Parameters
struct sk_buff * skb- buffer to check
gfp_t pri- priority for memory allocation
Description
If the socket buffer is a clone then this function creates a new copy of the data, drops a reference count on the old copy and returns the new copy with the reference count at 1. If the buffer is not a clone the original buffer is returned. When called with a spinlock held or from interrupt state pri must be
GFP_ATOMIC
NULLis returned on a memory allocation failure.
Parameters
const struct sk_buff_head * list_- list to peek at
Description
Peek an
sk_buff. Unlike most other operations you _MUST_ be careful with this one. A peek leaves the buffer on the list and someone else may run off with it. You must hold the appropriate locks or have a private queue to do this.Returns
NULLfor an empty list or a pointer to the head element. The reference count is not incremented and the reference is therefore volatile. Use with caution.
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struct sk_buff *
__skb_peek(const struct sk_buff_head * list_)¶ peek at the head of a non-empty
sk_buff_head
Parameters
const struct sk_buff_head * list_- list to peek at
Description
Likeskb_peek(), but the caller knows that the list is not empty.
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struct sk_buff *
skb_peek_next(struct sk_buff * skb, const struct sk_buff_head * list_)¶ peek skb following the given one from a queue
Parameters
struct sk_buff * skb- skb to start from
const struct sk_buff_head * list_- list to peek at
Description
ReturnsNULLwhen the end of the list is met or a pointer to the next element. The reference count is not incremented and the reference is therefore volatile. Use with caution.
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struct sk_buff *
skb_peek_tail(const struct sk_buff_head * list_)¶ peek at the tail of an
sk_buff_head
Parameters
const struct sk_buff_head * list_- list to peek at
Description
Peek an
sk_buff. Unlike most other operations you _MUST_ be careful with this one. A peek leaves the buffer on the list and someone else may run off with it. You must hold the appropriate locks or have a private queue to do this.Returns
NULLfor an empty list or a pointer to the tail element. The reference count is not incremented and the reference is therefore volatile. Use with caution.
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__u32
skb_queue_len(const struct sk_buff_head * list_)¶ get queue length
Parameters
const struct sk_buff_head * list_- list to measure
Description
Return the length of ansk_buffqueue.
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void
__skb_queue_head_init(struct sk_buff_head * list)¶ initialize non-spinlock portions of sk_buff_head
Parameters
struct sk_buff_head * list- queue to initialize
Description
This initializes only the list and queue length aspects of an sk_buff_head object. This allows to initialize the list aspects of an sk_buff_head without reinitializing things like the spinlock. It can also be used for on-stack sk_buff_head objects where the spinlock is known to not be used.
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void
skb_queue_splice(const struct sk_buff_head * list, struct sk_buff_head * head)¶ join two skb lists, this is designed for stacks
Parameters
const struct sk_buff_head * list- the new list to add
struct sk_buff_head * head- the place to add it in the first list
-
void
skb_queue_splice_init(struct sk_buff_head * list, struct sk_buff_head * head)¶ join two skb lists and reinitialise the emptied list
Parameters
struct sk_buff_head * list- the new list to add
struct sk_buff_head * head- the place to add it in the first list
Description
The list at list is reinitialised
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void
skb_queue_splice_tail(const struct sk_buff_head * list, struct sk_buff_head * head)¶ join two skb lists, each list being a queue
Parameters
const struct sk_buff_head * list- the new list to add
struct sk_buff_head * head- the place to add it in the first list
-
void
skb_queue_splice_tail_init(struct sk_buff_head * list, struct sk_buff_head * head)¶ join two skb lists and reinitialise the emptied list
Parameters
struct sk_buff_head * list- the new list to add
struct sk_buff_head * head- the place to add it in the first list
Description
Each of the lists is a queue. The list at list is reinitialised
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void
__skb_queue_after(struct sk_buff_head * list, struct sk_buff * prev, struct sk_buff * newsk)¶ queue a buffer at the list head
Parameters
struct sk_buff_head * list- list to use
struct sk_buff * prev- place after this buffer
struct sk_buff * newsk- buffer to queue
Description
Queue a buffer int the middle of a list. This function takes no locks and you must therefore hold required locks before calling it.
A buffer cannot be placed on two lists at the same time.
-
void
__skb_queue_head(struct sk_buff_head * list, struct sk_buff * newsk)¶ queue a buffer at the list head
Parameters
struct sk_buff_head * list- list to use
struct sk_buff * newsk- buffer to queue
Description
Queue a buffer at the start of a list. This function takes no locks and you must therefore hold required locks before calling it.
A buffer cannot be placed on two lists at the same time.
-
void
__skb_queue_tail(struct sk_buff_head * list, struct sk_buff * newsk)¶ queue a buffer at the list tail
Parameters
struct sk_buff_head * list- list to use
struct sk_buff * newsk- buffer to queue
Description
Queue a buffer at the end of a list. This function takes no locks and you must therefore hold required locks before calling it.
A buffer cannot be placed on two lists at the same time.
Parameters
struct sk_buff_head * list- list to dequeue from
Description
Remove the head of the list. This function does not take any locks so must be used with appropriate locks held only. The head item is returned orNULLif the list is empty.
Parameters
struct sk_buff_head * list- list to dequeue from
Description
Remove the tail of the list. This function does not take any locks so must be used with appropriate locks held only. The tail item is returned orNULLif the list is empty.
-
void
__skb_fill_page_desc(struct sk_buff * skb, int i, struct page * page, int off, int size)¶ initialise a paged fragment in an skb
Parameters
struct sk_buff * skb- buffer containing fragment to be initialised
int i- paged fragment index to initialise
struct page * page- the page to use for this fragment
int off- the offset to the data with page
int size- the length of the data
Description
Initialises the i’th fragment of skb to point to size bytes at
offset off within page.
Does not take any additional reference on the fragment.
-
void
skb_fill_page_desc(struct sk_buff * skb, int i, struct page * page, int off, int size)¶ initialise a paged fragment in an skb
Parameters
struct sk_buff * skb- buffer containing fragment to be initialised
int i- paged fragment index to initialise
struct page * page- the page to use for this fragment
int off- the offset to the data with page
int size- the length of the data
Description
As per __skb_fill_page_desc() – initialises the i’th fragment of
skb to point to size bytes at offset off within page. In
addition updates skb such that i is the last fragment.
Does not take any additional reference on the fragment.
Parameters
const struct sk_buff * skb- buffer to check
Description
Return the number of bytes of free space at the head of ansk_buff.
Parameters
const struct sk_buff * skb- buffer to check
Description
Return the number of bytes of free space at the tail of an sk_buff
Parameters
const struct sk_buff * skb- buffer to check
Description
Return the number of bytes of free space at the tail of an sk_buff allocated by sk_stream_alloc()
Parameters
struct sk_buff * skb- buffer to alter
int len- bytes to move
Description
Increase the headroom of an emptysk_buffby reducing the tail room. This is only allowed for an empty buffer.
-
void
skb_tailroom_reserve(struct sk_buff * skb, unsigned int mtu, unsigned int needed_tailroom)¶ adjust reserved_tailroom
Parameters
struct sk_buff * skb- buffer to alter
unsigned int mtu- maximum amount of headlen permitted
unsigned int needed_tailroom- minimum amount of reserved_tailroom
Description
Set reserved_tailroom so that headlen can be as large as possible but not larger than mtu and tailroom cannot be smaller than needed_tailroom. The required headroom should already have been reserved before using this function.
-
void
pskb_trim_unique(struct sk_buff * skb, unsigned int len)¶ remove end from a paged unique (not cloned) buffer
Parameters
struct sk_buff * skb- buffer to alter
unsigned int len- new length
Description
This is identical to pskb_trim except that the caller knows that the skb is not cloned so we should never get an error due to out- of-memory.
Parameters
struct sk_buff * skb- buffer to orphan
Description
If a buffer currently has an owner then we call the owner’s destructor function and make the skb unowned. The buffer continues to exist but is no longer charged to its former owner.
Parameters
struct sk_buff * skb- buffer to orphan frags from
gfp_t gfp_mask- allocation mask for replacement pages
Description
For each frag in the SKB which needs a destructor (i.e. has an owner) create a copy of that frag and release the original page by calling the destructor.
-
void
__skb_queue_purge(struct sk_buff_head * list)¶ empty a list
Parameters
struct sk_buff_head * list- list to empty
Description
Delete all buffers on ansk_bufflist. Each buffer is removed from the list and one reference dropped. This function does not take the list lock and the caller must hold the relevant locks to use it.
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struct sk_buff *
netdev_alloc_skb(struct net_device * dev, unsigned int length)¶ allocate an skbuff for rx on a specific device
Parameters
struct net_device * dev- network device to receive on
unsigned int length- length to allocate
Description
Allocate a new
sk_buffand assign it a usage count of one. The buffer has unspecified headroom built in. Users should allocate the headroom they think they need without accounting for the built in space. The built in space is used for optimisations.
NULLis returned if there is no free memory. Although this function allocates memory it can be called from an interrupt.
-
struct page *
__dev_alloc_pages(gfp_t gfp_mask, unsigned int order)¶ allocate page for network Rx
Parameters
gfp_t gfp_mask- allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
unsigned int order- size of the allocation
Description
Allocate a new page.
NULL is returned if there is no free memory.
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struct page *
__dev_alloc_page(gfp_t gfp_mask)¶ allocate a page for network Rx
Parameters
gfp_t gfp_mask- allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
Description
Allocate a new page.
NULL is returned if there is no free memory.
-
void
skb_propagate_pfmemalloc(struct page * page, struct sk_buff * skb)¶ Propagate pfmemalloc if skb is allocated after RX page
Parameters
struct page * page- The page that was allocated from skb_alloc_page
struct sk_buff * skb- The skb that may need pfmemalloc set
-
struct page *
skb_frag_page(const skb_frag_t * frag)¶ retrieve the page referred to by a paged fragment
Parameters
const skb_frag_t * frag- the paged fragment
Description
Returns the struct page associated with frag.
-
void
__skb_frag_ref(skb_frag_t * frag)¶ take an addition reference on a paged fragment.
Parameters
skb_frag_t * frag- the paged fragment
Description
Takes an additional reference on the paged fragment frag.
-
void
skb_frag_ref(struct sk_buff * skb, int f)¶ take an addition reference on a paged fragment of an skb.
Parameters
struct sk_buff * skb- the buffer
int f- the fragment offset.
Description
Takes an additional reference on the f’th paged fragment of skb.
-
void
__skb_frag_unref(skb_frag_t * frag)¶ release a reference on a paged fragment.
Parameters
skb_frag_t * frag- the paged fragment
Description
Releases a reference on the paged fragment frag.
-
void
skb_frag_unref(struct sk_buff * skb, int f)¶ release a reference on a paged fragment of an skb.
Parameters
struct sk_buff * skb- the buffer
int f- the fragment offset
Description
Releases a reference on the f’th paged fragment of skb.
-
void *
skb_frag_address(const skb_frag_t * frag)¶ gets the address of the data contained in a paged fragment
Parameters
const skb_frag_t * frag- the paged fragment buffer
Description
Returns the address of the data within frag. The page must already be mapped.
-
void *
skb_frag_address_safe(const skb_frag_t * frag)¶ gets the address of the data contained in a paged fragment
Parameters
const skb_frag_t * frag- the paged fragment buffer
Description
Returns the address of the data within frag. Checks that the page
is mapped and returns NULL otherwise.
-
void
__skb_frag_set_page(skb_frag_t * frag, struct page * page)¶ sets the page contained in a paged fragment
Parameters
skb_frag_t * frag- the paged fragment
struct page * page- the page to set
Description
Sets the fragment frag to contain page.
-
void
skb_frag_set_page(struct sk_buff * skb, int f, struct page * page)¶ sets the page contained in a paged fragment of an skb
Parameters
struct sk_buff * skb- the buffer
int f- the fragment offset
struct page * page- the page to set
Description
Sets the f’th fragment of skb to contain page.
-
dma_addr_t
skb_frag_dma_map(struct device * dev, const skb_frag_t * frag, size_t offset, size_t size, enum dma_data_direction dir)¶ maps a paged fragment via the DMA API
Parameters
struct device * dev- the device to map the fragment to
const skb_frag_t * frag- the paged fragment to map
size_t offset- the offset within the fragment (starting at the fragment’s own offset)
size_t size- the number of bytes to map
enum dma_data_direction dir- the direction of the mapping (
PCI_DMA_*)
Description
Maps the page associated with frag to device.
-
int
skb_clone_writable(const struct sk_buff * skb, unsigned int len)¶ is the header of a clone writable
Parameters
const struct sk_buff * skb- buffer to check
unsigned int len- length up to which to write
Description
Returns true if modifying the header part of the cloned buffer does not requires the data to be copied.
Parameters
struct sk_buff * skb- buffer to cow
unsigned int headroom- needed headroom
Description
If the skb passed lacks sufficient headroom or its data part is shared, data is reallocated. If reallocation fails, an error is returned and original skb is not changed.
The result is skb with writable area skb->head…skb->tail and at least headroom of space at head.
-
int
skb_cow_head(struct sk_buff * skb, unsigned int headroom)¶ skb_cow but only making the head writable
Parameters
struct sk_buff * skb- buffer to cow
unsigned int headroom- needed headroom
Description
This function is identical to skb_cow except that we replace the skb_cloned check by skb_header_cloned. It should be used when you only need to push on some header and do not need to modify the data.
Parameters
struct sk_buff * skb- buffer to pad
unsigned int len- minimal length
Description
Pads up a buffer to ensure the trailing bytes exist and are blanked. If the buffer already contains sufficient data it is untouched. Otherwise it is extended. Returns zero on success. The skb is freed on error.
-
int
__skb_put_padto(struct sk_buff * skb, unsigned int len, bool free_on_error)¶ increase size and pad an skbuff up to a minimal size
Parameters
struct sk_buff * skb- buffer to pad
unsigned int len- minimal length
bool free_on_error- free buffer on error
Description
Pads up a buffer to ensure the trailing bytes exist and are blanked. If the buffer already contains sufficient data it is untouched. Otherwise it is extended. Returns zero on success. The skb is freed on error if free_on_error is true.
-
int
skb_put_padto(struct sk_buff * skb, unsigned int len)¶ increase size and pad an skbuff up to a minimal size
Parameters
struct sk_buff * skb- buffer to pad
unsigned int len- minimal length
Description
Pads up a buffer to ensure the trailing bytes exist and are blanked. If the buffer already contains sufficient data it is untouched. Otherwise it is extended. Returns zero on success. The skb is freed on error.
Parameters
struct sk_buff * skb- buffer to linarize
Description
If there is no free memory -ENOMEM is returned, otherwise zero is returned and the old skb data released.
can any frag be overwritten
Parameters
const struct sk_buff * skb- buffer to test
Description
Return true if the skb has at least one frag that might be modified by an external entity (as in vmsplice()/sendfile())
Parameters
struct sk_buff * skb- buffer to process
Description
If there is no free memory -ENOMEM is returned, otherwise zero is returned and the old skb data released.
-
void
skb_postpull_rcsum(struct sk_buff * skb, const void * start, unsigned int len)¶ update checksum for received skb after pull
Parameters
struct sk_buff * skb- buffer to update
const void * start- start of data before pull
unsigned int len- length of data pulled
Description
After doing a pull on a received packet, you need to call this to update the CHECKSUM_COMPLETE checksum, or set ip_summed to CHECKSUM_NONE so that it can be recomputed from scratch.
-
void
skb_postpush_rcsum(struct sk_buff * skb, const void * start, unsigned int len)¶ update checksum for received skb after push
Parameters
struct sk_buff * skb- buffer to update
const void * start- start of data after push
unsigned int len- length of data pushed
Description
After doing a push on a received packet, you need to call this to update the CHECKSUM_COMPLETE checksum.
Parameters
struct sk_buff * skb- buffer to update
unsigned int len- length of data pulled
Description
This function performs an skb_push on the packet and updates the CHECKSUM_COMPLETE checksum. It should be used on receive path processing instead of skb_push unless you know that the checksum difference is zero (e.g., a valid IP header) or you are setting ip_summed to CHECKSUM_NONE.
Parameters
struct sk_buff * skb- buffer to trim
unsigned int len- new length
Description
This is exactly the same as pskb_trim except that it ensures the checksum of received packets are still valid after the operation. It can change skb pointers.
-
bool
skb_needs_linearize(struct sk_buff * skb, netdev_features_t features)¶ check if we need to linearize a given skb depending on the given device features.
Parameters
struct sk_buff * skb- socket buffer to check
netdev_features_t features- net device features
Description
Returns true if either: 1. skb has frag_list and the device doesn’t support FRAGLIST, or 2. skb is fragmented and the device does not support SG.
-
void
skb_get_timestamp(const struct sk_buff * skb, struct __kernel_old_timeval * stamp)¶ get timestamp from a skb
Parameters
const struct sk_buff * skb- skb to get stamp from
struct __kernel_old_timeval * stamp- pointer to struct __kernel_old_timeval to store stamp in
Description
Timestamps are stored in the skb as offsets to a base timestamp. This function converts the offset back to a struct timeval and stores it in stamp.
-
void
skb_complete_tx_timestamp(struct sk_buff * skb, struct skb_shared_hwtstamps * hwtstamps)¶ deliver cloned skb with tx timestamps
Parameters
struct sk_buff * skb- clone of the the original outgoing packet
struct skb_shared_hwtstamps * hwtstamps- hardware time stamps
Description
PHY drivers may accept clones of transmitted packets for timestamping via their phy_driver.txtstamp method. These drivers must call this function to return the skb back to the stack with a timestamp.
-
void
skb_tstamp_tx(struct sk_buff * orig_skb, struct skb_shared_hwtstamps * hwtstamps)¶ queue clone of skb with send time stamps
Parameters
struct sk_buff * orig_skb- the original outgoing packet
struct skb_shared_hwtstamps * hwtstamps- hardware time stamps, may be NULL if not available
Description
If the skb has a socket associated, then this function clones the skb (thus sharing the actual data and optional structures), stores the optional hardware time stamping information (if non NULL) or generates a software time stamp (otherwise), then queues the clone to the error queue of the socket. Errors are silently ignored.
Parameters
struct sk_buff * skb- A socket buffer.
Description
Ethernet MAC Drivers should call this function in their hard_xmit() function immediately before giving the sk_buff to the MAC hardware.
Specifically, one should make absolutely sure that this function is called before TX completion of this packet can trigger. Otherwise the packet could potentially already be freed.
Parameters
struct sk_buff * skb- the original outgoing packet
bool acked- ack status
Parameters
struct sk_buff * skb- packet to process
Description
This function calculates the checksum over the entire packet plus the value of skb->csum. The latter can be used to supply the checksum of a pseudo header as used by TCP/UDP. It returns the checksum.
For protocols that contain complete checksums such as ICMP/TCP/UDP, this function can be used to verify that checksum on received packets. In that case the function should return zero if the checksum is correct. In particular, this function will return zero if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the hardware has already verified the correctness of the checksum.
-
struct
skb_ext¶ sk_buff extensions
Definition
struct skb_ext {
refcount_t refcnt;
u8 offset[SKB_EXT_NUM];
u8 chunks;
char data[0];
};
Members
refcnt- 1 on allocation, deallocated on 0
offset- offset to add to data to obtain extension address
chunks- size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
data- start of extension data, variable sized
Note
- offsets/lengths are stored in chunks of 8 bytes, this allows
- to use ‘u8’ types while allowing up to 2kb worth of extension data.
Parameters
const struct sk_buff * skb- skb to check
Description
fresh skbs have their ip_summed set to CHECKSUM_NONE. Instead of forcing ip_summed to CHECKSUM_NONE, we can use this helper, to document places where we make this assertion.
Parameters
const struct sk_buff * skb- skb to check
Description
The head on skbs build around a head frag can be removed if they are not cloned. This function returns true if the skb head is locked down due to either being allocated via kmalloc, or by being a clone with multiple references to the head.
-
struct
sock_common¶ minimal network layer representation of sockets
Definition
struct sock_common {
union {
__addrpair skc_addrpair;
struct {
__be32 skc_daddr;
__be32 skc_rcv_saddr;
};
};
union {
unsigned int skc_hash;
__u16 skc_u16hashes[2];
};
union {
__portpair skc_portpair;
struct {
__be16 skc_dport;
__u16 skc_num;
};
};
unsigned short skc_family;
volatile unsigned char skc_state;
unsigned char skc_reuse:4;
unsigned char skc_reuseport:1;
unsigned char skc_ipv6only:1;
unsigned char skc_net_refcnt:1;
int skc_bound_dev_if;
union {
struct hlist_node skc_bind_node;
struct hlist_node skc_portaddr_node;
};
struct proto *skc_prot;
possible_net_t skc_net;
#if IS_ENABLED(CONFIG_IPV6);
struct in6_addr skc_v6_daddr;
struct in6_addr skc_v6_rcv_saddr;
#endif;
atomic64_t skc_cookie;
union {
unsigned long skc_flags;
struct sock *skc_listener;
struct inet_timewait_death_row *skc_tw_dr;
};
union {
struct hlist_node skc_node;
struct hlist_nulls_node skc_nulls_node;
};
unsigned short skc_tx_queue_mapping;
#ifdef CONFIG_XPS;
unsigned short skc_rx_queue_mapping;
#endif;
union {
int skc_incoming_cpu;
u32 skc_rcv_wnd;
u32 skc_tw_rcv_nxt;
};
refcount_t skc_refcnt;
};
Members
{unnamed_union}- anonymous
{unnamed_struct}- anonymous
skc_daddr- Foreign IPv4 addr
skc_rcv_saddr- Bound local IPv4 addr
{unnamed_union}- anonymous
skc_hash- hash value used with various protocol lookup tables
skc_u16hashes- two u16 hash values used by UDP lookup tables
{unnamed_union}- anonymous
{unnamed_struct}- anonymous
skc_dport- placeholder for inet_dport/tw_dport
skc_num- placeholder for inet_num/tw_num
skc_family- network address family
skc_state- Connection state
skc_reuseSO_REUSEADDRsettingskc_reuseportSO_REUSEPORTsettingskc_bound_dev_if- bound device index if != 0
{unnamed_union}- anonymous
skc_bind_node- bind hash linkage for various protocol lookup tables
skc_portaddr_node- second hash linkage for UDP/UDP-Lite protocol
skc_prot- protocol handlers inside a network family
skc_net- reference to the network namespace of this socket
{unnamed_union}- anonymous
skc_flags- place holder for sk_flags
SO_LINGER(l_onoff),SO_BROADCAST,SO_KEEPALIVE,SO_OOBINLINEsettings,SO_TIMESTAMPINGsettings {unnamed_union}- anonymous
skc_node- main hash linkage for various protocol lookup tables
skc_nulls_node- main hash linkage for TCP/UDP/UDP-Lite protocol
skc_tx_queue_mapping- tx queue number for this connection
skc_rx_queue_mapping- rx queue number for this connection
{unnamed_union}- anonymous
skc_incoming_cpu- record/match cpu processing incoming packets
skc_refcnt- reference count
Description
This is the minimal network layer representation of sockets, the header for struct sock and struct inet_timewait_sock.
-
struct
sock¶ network layer representation of sockets
Definition
struct sock {
struct sock_common __sk_common;
#define sk_node __sk_common.skc_node;
#define sk_nulls_node __sk_common.skc_nulls_node;
#define sk_refcnt __sk_common.skc_refcnt;
#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping;
#ifdef CONFIG_XPS;
#define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping;
#endif;
#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin;
#define sk_dontcopy_end __sk_common.skc_dontcopy_end;
#define sk_hash __sk_common.skc_hash;
#define sk_portpair __sk_common.skc_portpair;
#define sk_num __sk_common.skc_num;
#define sk_dport __sk_common.skc_dport;
#define sk_addrpair __sk_common.skc_addrpair;
#define sk_daddr __sk_common.skc_daddr;
#define sk_rcv_saddr __sk_common.skc_rcv_saddr;
#define sk_family __sk_common.skc_family;
#define sk_state __sk_common.skc_state;
#define sk_reuse __sk_common.skc_reuse;
#define sk_reuseport __sk_common.skc_reuseport;
#define sk_ipv6only __sk_common.skc_ipv6only;
#define sk_net_refcnt __sk_common.skc_net_refcnt;
#define sk_bound_dev_if __sk_common.skc_bound_dev_if;
#define sk_bind_node __sk_common.skc_bind_node;
#define sk_prot __sk_common.skc_prot;
#define sk_net __sk_common.skc_net;
#define sk_v6_daddr __sk_common.skc_v6_daddr;
#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr;
#define sk_cookie __sk_common.skc_cookie;
#define sk_incoming_cpu __sk_common.skc_incoming_cpu;
#define sk_flags __sk_common.skc_flags;
#define sk_rxhash __sk_common.skc_rxhash;
socket_lock_t sk_lock;
atomic_t sk_drops;
int sk_rcvlowat;
struct sk_buff_head sk_error_queue;
struct sk_buff *sk_rx_skb_cache;
struct sk_buff_head sk_receive_queue;
struct {
atomic_t rmem_alloc;
int len;
struct sk_buff *head;
struct sk_buff *tail;
} sk_backlog;
#define sk_rmem_alloc sk_backlog.rmem_alloc;
int sk_forward_alloc;
#ifdef CONFIG_NET_RX_BUSY_POLL;
unsigned int sk_ll_usec;
unsigned int sk_napi_id;
#endif;
int sk_rcvbuf;
struct sk_filter __rcu *sk_filter;
union {
struct socket_wq __rcu *sk_wq;
struct socket_wq *sk_wq_raw;
};
#ifdef CONFIG_XFRM;
struct xfrm_policy __rcu *sk_policy[2];
#endif;
struct dst_entry *sk_rx_dst;
struct dst_entry __rcu *sk_dst_cache;
atomic_t sk_omem_alloc;
int sk_sndbuf;
int sk_wmem_queued;
refcount_t sk_wmem_alloc;
unsigned long sk_tsq_flags;
union {
struct sk_buff *sk_send_head;
struct rb_root tcp_rtx_queue;
};
struct sk_buff *sk_tx_skb_cache;
struct sk_buff_head sk_write_queue;
__s32 sk_peek_off;
int sk_write_pending;
__u32 sk_dst_pending_confirm;
u32 sk_pacing_status;
long sk_sndtimeo;
struct timer_list sk_timer;
__u32 sk_priority;
__u32 sk_mark;
unsigned long sk_pacing_rate;
unsigned long sk_max_pacing_rate;
struct page_frag sk_frag;
netdev_features_t sk_route_caps;
netdev_features_t sk_route_nocaps;
netdev_features_t sk_route_forced_caps;
int sk_gso_type;
unsigned int sk_gso_max_size;
gfp_t sk_allocation;
__u32 sk_txhash;
unsigned int __sk_flags_offset[0];
#ifdef __BIG_ENDIAN_BITFIELD;
#define SK_FL_PROTO_SHIFT 16;
#define SK_FL_PROTO_MASK 0x00ff0000;
#define SK_FL_TYPE_SHIFT 0;
#define SK_FL_TYPE_MASK 0x0000ffff;
#else;
#define SK_FL_PROTO_SHIFT 8;
#define SK_FL_PROTO_MASK 0x0000ff00;
#define SK_FL_TYPE_SHIFT 16;
#define SK_FL_TYPE_MASK 0xffff0000;
#endif;
unsigned int sk_padding : 1,sk_kern_sock : 1,sk_no_check_tx : 1,sk_no_check_rx : 1,sk_userlocks : 4,sk_protocol : 8, sk_type : 16;
#define SK_PROTOCOL_MAX U8_MAX;
u16 sk_gso_max_segs;
u8 sk_pacing_shift;
unsigned long sk_lingertime;
struct proto *sk_prot_creator;
rwlock_t sk_callback_lock;
int sk_err, sk_err_soft;
u32 sk_ack_backlog;
u32 sk_max_ack_backlog;
kuid_t sk_uid;
struct pid *sk_peer_pid;
const struct cred *sk_peer_cred;
long sk_rcvtimeo;
ktime_t sk_stamp;
#if BITS_PER_LONG==32;
seqlock_t sk_stamp_seq;
#endif;
u16 sk_tsflags;
u8 sk_shutdown;
u32 sk_tskey;
atomic_t sk_zckey;
u8 sk_clockid;
u8 sk_txtime_deadline_mode : 1,sk_txtime_report_errors : 1, sk_txtime_unused : 6;
struct socket *sk_socket;
void *sk_user_data;
#ifdef CONFIG_SECURITY;
void *sk_security;
#endif;
struct sock_cgroup_data sk_cgrp_data;
struct mem_cgroup *sk_memcg;
void (*sk_state_change)(struct sock *sk);
void (*sk_data_ready)(struct sock *sk);
void (*sk_write_space)(struct sock *sk);
void (*sk_error_report)(struct sock *sk);
int (*sk_backlog_rcv)(struct sock *sk, struct sk_buff *skb);
#ifdef CONFIG_SOCK_VALIDATE_XMIT;
struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk,struct net_device *dev, struct sk_buff *skb);
#endif;
void (*sk_destruct)(struct sock *sk);
struct sock_reuseport __rcu *sk_reuseport_cb;
#ifdef CONFIG_BPF_SYSCALL;
struct bpf_sk_storage __rcu *sk_bpf_storage;
#endif;
struct rcu_head sk_rcu;
};
Members
__sk_common- shared layout with inet_timewait_sock
sk_lock- synchronizer
sk_drops- raw/udp drops counter
sk_rcvlowatSO_RCVLOWATsettingsk_error_queue- rarely used
sk_receive_queue- incoming packets
sk_backlog- always used with the per-socket spinlock held
sk_forward_alloc- space allocated forward
sk_ll_usec- usecs to busypoll when there is no data
sk_napi_id- id of the last napi context to receive data for sk
sk_rcvbuf- size of receive buffer in bytes
sk_filter- socket filtering instructions
{unnamed_union}- anonymous
sk_wq- sock wait queue and async head
sk_policy- flow policy
sk_rx_dst- receive input route used by early demux
sk_dst_cache- destination cache
sk_omem_alloc- “o” is “option” or “other”
sk_sndbuf- size of send buffer in bytes
sk_wmem_queued- persistent queue size
sk_wmem_alloc- transmit queue bytes committed
sk_tsq_flags- TCP Small Queues flags
{unnamed_union}- anonymous
sk_send_head- front of stuff to transmit
sk_write_queue- Packet sending queue
sk_peek_off- current peek_offset value
sk_write_pending- a write to stream socket waits to start
sk_dst_pending_confirm- need to confirm neighbour
sk_pacing_status- Pacing status (requested, handled by sch_fq)
sk_sndtimeoSO_SNDTIMEOsettingsk_timer- sock cleanup timer
sk_prioritySO_PRIORITYsettingsk_mark- generic packet mark
sk_pacing_rate- Pacing rate (if supported by transport/packet scheduler)
sk_max_pacing_rate- Maximum pacing rate (
SO_MAX_PACING_RATE) sk_frag- cached page frag
sk_route_caps- route capabilities (e.g.
NETIF_F_TSO) sk_route_nocaps- forbidden route capabilities (e.g NETIF_F_GSO_MASK)
sk_gso_type- GSO type (e.g.
SKB_GSO_TCPV4) sk_gso_max_size- Maximum GSO segment size to build
sk_allocation- allocation mode
sk_txhash- computed flow hash for use on transmit
__sk_flags_offset- empty field used to determine location of bitfield
sk_padding- unused element for alignment
sk_kern_sock- True if sock is using kernel lock classes
sk_no_check_txSO_NO_CHECKsetting, set checksum in TX packetssk_no_check_rx- allow zero checksum in RX packets
sk_userlocksSO_SNDBUFandSO_RCVBUFsettingssk_protocol- which protocol this socket belongs in this network family
sk_type- socket type (
SOCK_STREAM, etc) sk_gso_max_segs- Maximum number of GSO segments
sk_pacing_shift- scaling factor for TCP Small Queues
sk_lingertimeSO_LINGERl_linger settingsk_prot_creator- sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
sk_callback_lock- used with the callbacks in the end of this struct
sk_err- last error
sk_err_soft- errors that don’t cause failure but are the cause of a persistent failure not just ‘timed out’
sk_ack_backlog- current listen backlog
sk_max_ack_backlog- listen backlog set in listen()
sk_uid- user id of owner
sk_peer_pidstruct pidfor this socket’s peersk_peer_credSO_PEERCREDsettingsk_rcvtimeoSO_RCVTIMEOsettingsk_stamp- time stamp of last packet received
sk_stamp_seq- lock for accessing sk_stamp on 32 bit architectures only
sk_tsflags- SO_TIMESTAMPING socket options
sk_shutdown- mask of
SEND_SHUTDOWNand/orRCV_SHUTDOWN sk_tskey- counter to disambiguate concurrent tstamp requests
sk_zckey- counter to order MSG_ZEROCOPY notifications
sk_clockid- clockid used by time-based scheduling (SO_TXTIME)
sk_txtime_deadline_mode- set deadline mode for SO_TXTIME
sk_txtime_unused- unused txtime flags
sk_socket- Identd and reporting IO signals
sk_user_data- RPC layer private data
sk_security- used by security modules
sk_cgrp_data- cgroup data for this cgroup
sk_memcg- this socket’s memory cgroup association
sk_state_change- callback to indicate change in the state of the sock
sk_data_ready- callback to indicate there is data to be processed
sk_write_space- callback to indicate there is bf sending space available
sk_error_report- callback to indicate errors (e.g.
MSG_ERRQUEUE) sk_backlog_rcv- callback to process the backlog
sk_destruct- called at sock freeing time, i.e. when all refcnt == 0
sk_reuseport_cb- reuseport group container
sk_rcu- used during RCU grace period
-
sk_for_each_entry_offset_rcu(tpos, pos, head, offset)¶ iterate over a list at a given struct offset
Parameters
tpos- the type * to use as a loop cursor.
pos- the
struct hlist_nodeto use as a loop cursor. head- the head for your list.
offset- offset of hlist_node within the struct.
Parameters
struct sock * sk- socket
bool slow- slow mode
Description
fast unlock socket for user context. If slow mode is on, we call regular release_sock()
Parameters
const struct sock * sk- socket
Description
Returns sk_wmem_alloc minus initial offset of one
Parameters
const struct sock * sk- socket
Description
Returns sk_rmem_alloc
Parameters
const struct sock * sk- socket
Description
Returns true if socket has write or read allocations
-
bool
skwq_has_sleeper(struct socket_wq * wq)¶ check if there are any waiting processes
Parameters
struct socket_wq * wq- struct socket_wq
Description
Returns true if socket_wq has waiting processes
The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory barrier call. They were added due to the race found within the tcp code.
Consider following tcp code paths:
CPU1 CPU2
sys_select receive packet
... ...
__add_wait_queue update tp->rcv_nxt
... ...
tp->rcv_nxt check sock_def_readable
... {
schedule rcu_read_lock();
wq = rcu_dereference(sk->sk_wq);
if (wq && waitqueue_active(&wq->wait))
wake_up_interruptible(&wq->wait)
...
}
The race for tcp fires when the __add_wait_queue changes done by CPU1 stay in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1 could then endup calling schedule and sleep forever if there are no more data on the socket.
-
void
sock_poll_wait(struct file * filp, struct socket * sock, poll_table * p)¶ place memory barrier behind the poll_wait call.
Parameters
struct file * filp- file
struct socket * sock- socket to wait on
poll_table * p- poll_table
Description
See the comments in the wq_has_sleeper function.
Parameters
struct sock * sk- socket
Description
If socket allocation mode allows current thread to sleep, it means its safe to use the per task page_frag instead of the per socket one.
-
void
_sock_tx_timestamp(struct sock * sk, __u16 tsflags, __u8 * tx_flags, __u32 * tskey)¶ checks whether the outgoing packet is to be time stamped
Parameters
struct sock * sk- socket sending this packet
__u16 tsflags- timestamping flags to use
__u8 * tx_flags- completed with instructions for time stamping
__u32 * tskey- filled in with next sk_tskey (not for TCP, which uses seqno)
Note
callers should take care of initial *tx_flags value (usually 0)
-
DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key)¶ Release a skb if it is no longer needed
Parameters
tcp_rx_skb_cache_key- undescribed
Description
This routine must be called with interrupts disabled or with the socket locked so that the sk_buff queue operation is ok.
-
struct file *
sock_alloc_file(struct socket * sock, int flags, const char * dname)¶ Bind a
socketto afile
Parameters
struct socket * sock- socket
int flags- file status flags
const char * dname- protocol name
Description
Returns thefilebound with sock, implicitly storing it in sock->file. If dname isNULL, sets to “”. On failure the return is a ERR pointer (see linux/err.h). This function uses GFP_KERNEL internally.
Parameters
struct file * file- file
int * err- pointer to an error code return
Description
On failure returnsNULLand assigns -ENOTSOCK to err.
Parameters
int fd- file handle
int * err- pointer to an error code return
Description
The file handle passed in is locked and the socket it is bound to is returned. If an error occurs the err pointer is overwritten with a negative errno code and NULL is returned. The function checks for both invalid handles and passing a handle which is not a socket.
On a success the socket object pointer is returned.
Parameters
void- no arguments
Description
Allocate a new inode and socket object. The two are bound together and initialised. The socket is then returned. If we are out of inodes NULL is returned. This functions uses GFP_KERNEL internally.
Parameters
struct socket * sock- socket
struct msghdr * msg- message to send
Description
Sends msg through sock, passing through LSM. Returns the number of bytes sent, or an error code.
-
int
kernel_sendmsg(struct socket * sock, struct msghdr * msg, struct kvec * vec, size_t num, size_t size)¶ send a message through sock (kernel-space)
Parameters
struct socket * sock- socket
struct msghdr * msg- message header
struct kvec * vec- kernel vec
size_t num- vec array length
size_t size- total message data size
Description
Builds the message data with vec and sends it through sock. Returns the number of bytes sent, or an error code.
-
int
kernel_sendmsg_locked(struct sock * sk, struct msghdr * msg, struct kvec * vec, size_t num, size_t size)¶ send a message through sock (kernel-space)
Parameters
struct sock * sk- sock
struct msghdr * msg- message header
struct kvec * vec- output s/g array
size_t num- output s/g array length
size_t size- total message data size
Description
Builds the message data with vec and sends it through sock. Returns the number of bytes sent, or an error code. Caller must hold sk.
Parameters
struct socket * sock- socket
struct msghdr * msg- message to receive
int flags- message flags
Description
Receives msg from sock, passing through LSM. Returns the total number of bytes received, or an error.
-
int
kernel_recvmsg(struct socket * sock, struct msghdr * msg, struct kvec * vec, size_t num, size_t size, int flags)¶ Receive a message from a socket (kernel space)
Parameters
struct socket * sock- The socket to receive the message from
struct msghdr * msg- Received message
struct kvec * vec- Input s/g array for message data
size_t num- Size of input s/g array
size_t size- Number of bytes to read
int flags- Message flags (MSG_DONTWAIT, etc…)
Description
On return the msg structure contains the scatter/gather array passed in the vec argument. The array is modified so that it consists of the unfilled portion of the original array.
The returned value is the total number of bytes received, or an error.
-
struct ns_common *
get_net_ns(struct ns_common * ns)¶ increment the refcount of the network namespace
Parameters
struct ns_common * ns- common namespace (net)
Description
Returns the net’s common namespace.
Parameters
int family- protocol family (AF_INET, …)
int type- communication type (SOCK_STREAM, …)
int protocol- protocol (0, …)
struct socket ** res- new socket
Description
Creates a new socket and assigns it to res, passing through LSM. The new socket initialization is not complete, seekernel_accept(). Returns 0 or an error. On failure res is set toNULL. This function internally uses GFP_KERNEL.
-
int
__sock_create(struct net * net, int family, int type, int protocol, struct socket ** res, int kern)¶ creates a socket
Parameters
struct net * net- net namespace
int family- protocol family (AF_INET, …)
int type- communication type (SOCK_STREAM, …)
int protocol- protocol (0, …)
struct socket ** res- new socket
int kern- boolean for kernel space sockets
Description
Creates a new socket and assigns it to res, passing through LSM. Returns 0 or an error. On failure res is set toNULL. kern must be set to true if the socket resides in kernel space. This function internally uses GFP_KERNEL.
Parameters
int family- protocol family (AF_INET, …)
int type- communication type (SOCK_STREAM, …)
int protocol- protocol (0, …)
struct socket ** res- new socket
Description
A wrapper around__sock_create(). Returns 0 or an error. This function internally uses GFP_KERNEL.
-
int
sock_create_kern(struct net * net, int family, int type, int protocol, struct socket ** res)¶ creates a socket (kernel space)
Parameters
struct net * net- net namespace
int family- protocol family (AF_INET, …)
int type- communication type (SOCK_STREAM, …)
int protocol- protocol (0, …)
struct socket ** res- new socket
Description
A wrapper around__sock_create(). Returns 0 or an error. This function internally uses GFP_KERNEL.
-
int
sock_register(const struct net_proto_family * ops)¶ add a socket protocol handler
Parameters
const struct net_proto_family * ops- description of protocol
Description
This function is called by a protocol handler that wants to advertise its address family, and have it linked into the socket interface. The value ops->family corresponds to the socket system call protocol family.
-
void
sock_unregister(int family)¶ remove a protocol handler
Parameters
int family- protocol family to remove
Description
This function is called by a protocol handler that wants to remove its address family, and have it unlinked from the new socket creation.
If protocol handler is a module, then it can use module reference counts to protect against new references. If protocol handler is not a module then it needs to provide its own protection in the ops->create routine.
-
int
kernel_bind(struct socket * sock, struct sockaddr * addr, int addrlen)¶ bind an address to a socket (kernel space)
Parameters
struct socket * sock- socket
struct sockaddr * addr- address
int addrlen- length of address
Description
Returns 0 or an error.
Parameters
struct socket * sock- socket
int backlog- pending connections queue size
Description
Returns 0 or an error.
-
int
kernel_accept(struct socket * sock, struct socket ** newsock, int flags)¶ accept a connection (kernel space)
Parameters
struct socket * sock- listening socket
struct socket ** newsock- new connected socket
int flags- flags
Description
flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0. If it fails, newsock is guaranteed to beNULL. Returns 0 or an error.
-
int
kernel_connect(struct socket * sock, struct sockaddr * addr, int addrlen, int flags)¶ connect a socket (kernel space)
Parameters
struct socket * sock- socket
struct sockaddr * addr- address
int addrlen- address length
int flags- flags (O_NONBLOCK, …)
Description
For datagram sockets, addr is the addres to which datagrams are sent by default, and the only address from which datagrams are received. For stream sockets, attempts to connect to addr. Returns 0 or an error code.
-
int
kernel_getsockname(struct socket * sock, struct sockaddr * addr)¶ get the address which the socket is bound (kernel space)
Parameters
struct socket * sock- socket
struct sockaddr * addr- address holder
Description
Fills the addr pointer with the address which the socket is bound. Returns 0 or an error code.
-
int
kernel_getpeername(struct socket * sock, struct sockaddr * addr)¶ get the address which the socket is connected (kernel space)
Parameters
struct socket * sock- socket
struct sockaddr * addr- address holder
Description
Fills the addr pointer with the address which the socket is connected. Returns 0 or an error code.
-
int
kernel_getsockopt(struct socket * sock, int level, int optname, char * optval, int * optlen)¶ get a socket option (kernel space)
Parameters
struct socket * sock- socket
int level- API level (SOL_SOCKET, …)
int optname- option tag
char * optval- option value
int * optlen- option length
Description
Assigns the option length to optlen. Returns 0 or an error.
-
int
kernel_setsockopt(struct socket * sock, int level, int optname, char * optval, unsigned int optlen)¶ set a socket option (kernel space)
Parameters
struct socket * sock- socket
int level- API level (SOL_SOCKET, …)
int optname- option tag
char * optval- option value
unsigned int optlen- option length
Description
Returns 0 or an error.
-
int
kernel_sendpage(struct socket * sock, struct page * page, int offset, size_t size, int flags)¶ send a
pagethrough a socket (kernel space)
Parameters
struct socket * sock- socket
struct page * page- page
int offset- page offset
size_t size- total size in bytes
int flags- flags (MSG_DONTWAIT, …)
Description
Returns the total amount sent in bytes or an error.
-
int
kernel_sendpage_locked(struct sock * sk, struct page * page, int offset, size_t size, int flags)¶ send a
pagethrough the locked sock (kernel space)
Parameters
struct sock * sk- sock
struct page * page- page
int offset- page offset
size_t size- total size in bytes
int flags- flags (MSG_DONTWAIT, …)
Description
Returns the total amount sent in bytes or an error. Caller must hold sk.
-
int
kernel_sock_shutdown(struct socket * sock, enum sock_shutdown_cmd how)¶ shut down part of a full-duplex connection (kernel space)
Parameters
struct socket * sock- socket
enum sock_shutdown_cmd how- connection part
Description
Returns 0 or an error.
Parameters
struct sock * sk- socket
Description
This routine returns the IP overhead imposed by a socket i.e. the length of the underlying IP header, depending on whether this is an IPv4 or IPv6 socket and the length from IP options turned on at the socket. Assumes that the caller has a lock on the socket.
-
struct sk_buff *
__alloc_skb(unsigned int size, gfp_t gfp_mask, int flags, int node)¶ allocate a network buffer
Parameters
unsigned int size- size to allocate
gfp_t gfp_mask- allocation mask
int flags- If SKB_ALLOC_FCLONE is set, allocate from fclone cache instead of head cache and allocate a cloned (child) skb. If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for allocations in case the data is required for writeback
int node- numa node to allocate memory on
Description
Allocate a new
sk_buff. The returned buffer has no headroom and a tail room of at least size bytes. The object has a reference count of one. The return is the buffer. On a failure the return isNULL.Buffers may only be allocated from interrupts using a gfp_mask of
GFP_ATOMIC.
-
struct sk_buff *
build_skb_around(struct sk_buff * skb, void * data, unsigned int frag_size)¶ build a network buffer around provided skb
Parameters
struct sk_buff * skb- sk_buff provide by caller, must be memset cleared
void * data- data buffer provided by caller
unsigned int frag_size- size of data, or 0 if head was kmalloced
-
void *
netdev_alloc_frag(unsigned int fragsz)¶ allocate a page fragment
Parameters
unsigned int fragsz- fragment size
Description
Allocates a frag from a page for receive buffer. Uses GFP_ATOMIC allocations.
-
struct sk_buff *
__netdev_alloc_skb(struct net_device * dev, unsigned int len, gfp_t gfp_mask)¶ allocate an skbuff for rx on a specific device
Parameters
struct net_device * dev- network device to receive on
unsigned int len- length to allocate
gfp_t gfp_mask- get_free_pages mask, passed to alloc_skb
Description
Allocate a new
sk_buffand assign it a usage count of one. The buffer has NET_SKB_PAD headroom built in. Users should allocate the headroom they think they need without accounting for the built in space. The built in space is used for optimisations.
NULLis returned if there is no free memory.
-
struct sk_buff *
__napi_alloc_skb(struct napi_struct * napi, unsigned int len, gfp_t gfp_mask)¶ allocate skbuff for rx in a specific NAPI instance
Parameters
struct napi_struct * napi- napi instance this buffer was allocated for
unsigned int len- length to allocate
gfp_t gfp_mask- get_free_pages mask, passed to alloc_skb and alloc_pages
Description
Allocate a new sk_buff for use in NAPI receive. This buffer will attempt to allocate the head from a special reserved region used only for NAPI Rx allocation. By doing this we can save several CPU cycles by avoiding having to disable and re-enable IRQs.
NULLis returned if there is no free memory.
Parameters
struct sk_buff * skb- buffer
Description
Free an sk_buff. Release anything attached to the buffer. Clean the state. This is an internal helper function. Users should always call kfree_skb
Parameters
struct sk_buff * skb- buffer to free
Description
Drop a reference to the buffer and free it if the usage count has hit zero.
Parameters
struct sk_buff * skb- buffer that triggered an error
Description
Report xmit error if a device callback is tracking this skb. skb must be freed afterwards.
Parameters
struct sk_buff * skb- buffer to free
Description
Drop a ref to the buffer and free it if the usage count has hit zero Functions identically to kfree_skb, but kfree_skb assumes that the frame is being dropped after a failure and notes that
-
struct sk_buff *
alloc_skb_for_msg(struct sk_buff * first)¶ allocate sk_buff to wrap frag list forming a msg
Parameters
struct sk_buff * first- first sk_buff of the msg
Parameters
struct sk_buff * dst- the skb to receive the contents
struct sk_buff * src- the skb to supply the contents
Description
This is identical to skb_clone except that the target skb is supplied by the user.
The target skb is returned upon exit.
-
int
skb_copy_ubufs(struct sk_buff * skb, gfp_t gfp_mask)¶ copy userspace skb frags buffers to kernel
Parameters
struct sk_buff * skb- the skb to modify
gfp_t gfp_mask- allocation priority
Description
This must be called on SKBTX_DEV_ZEROCOPY skb. It will copy all frags into kernel and drop the reference to userspace pages.
If this function is called from an interrupt gfp_mask() must be
GFP_ATOMIC.Returns 0 on success or a negative error code on failure to allocate kernel memory to copy to.
Parameters
struct sk_buff * skb- buffer to clone
gfp_t gfp_mask- allocation priority
Description
Duplicate an
sk_buff. The new one is not owned by a socket. Both copies share the same packet data but not structure. The new buffer has a reference count of 1. If the allocation fails the function returnsNULLotherwise the new buffer is returned.If this function is called from an interrupt gfp_mask() must be
GFP_ATOMIC.
-
struct sk_buff *
skb_copy(const struct sk_buff * skb, gfp_t gfp_mask)¶ create private copy of an sk_buff
Parameters
const struct sk_buff * skb- buffer to copy
gfp_t gfp_mask- allocation priority
Description
Make a copy of both an
sk_buffand its data. This is used when the caller wishes to modify the data and needs a private copy of the data to alter. ReturnsNULLon failure or the pointer to the buffer on success. The returned buffer has a reference count of 1.As by-product this function converts non-linear
sk_buffto linear one, so thatsk_buffbecomes completely private and caller is allowed to modify all the data of returned buffer. This means that this function is not recommended for use in circumstances when only header is going to be modified. Use pskb_copy() instead.
-
struct sk_buff *
__pskb_copy_fclone(struct sk_buff * skb, int headroom, gfp_t gfp_mask, bool fclone)¶ create copy of an sk_buff with private head.
Parameters
struct sk_buff * skb- buffer to copy
int headroom- headroom of new skb
gfp_t gfp_mask- allocation priority
bool fclone- if true allocate the copy of the skb from the fclone cache instead of the head cache; it is recommended to set this to true for the cases where the copy will likely be cloned
Description
Make a copy of both ansk_buffand part of its data, located in header. Fragmented data remain shared. This is used when the caller wishes to modify only header ofsk_buffand needs private copy of the header to alter. ReturnsNULLon failure or the pointer to the buffer on success. The returned buffer has a reference count of 1.
-
int
pskb_expand_head(struct sk_buff * skb, int nhead, int ntail, gfp_t gfp_mask)¶ reallocate header of
sk_buff
Parameters
struct sk_buff * skb- buffer to reallocate
int nhead- room to add at head
int ntail- room to add at tail
gfp_t gfp_mask- allocation priority
Description
Expands (or creates identical copy, if nhead and ntail are zero) header of skb.
sk_buffitself is not changed.sk_buffMUST have reference count of 1. Returns zero in the case of success or error, if expansion failed. In the last case,sk_buffis not changed.All the pointers pointing into skb header may change and must be reloaded after call to this function.
-
struct sk_buff *
skb_copy_expand(const struct sk_buff * skb, int newheadroom, int newtailroom, gfp_t gfp_mask)¶ copy and expand sk_buff
Parameters
const struct sk_buff * skb- buffer to copy
int newheadroom- new free bytes at head
int newtailroom- new free bytes at tail
gfp_t gfp_mask- allocation priority
Description
Make a copy of both an
sk_buffand its data and while doing so allocate additional space.This is used when the caller wishes to modify the data and needs a private copy of the data to alter as well as more space for new fields. Returns
NULLon failure or the pointer to the buffer on success. The returned buffer has a reference count of 1.You must pass
GFP_ATOMICas the allocation priority if this function is called from an interrupt.
Parameters
struct sk_buff * skb- buffer to pad
int pad- space to pad
bool free_on_error- free buffer on error
Description
Ensure that a buffer is followed by a padding area that is zero filled. Used by network drivers which may DMA or transfer data beyond the buffer end onto the wire.
May return error in out of memory cases. The skb is freed on error if free_on_error is true.
-
void *
pskb_put(struct sk_buff * skb, struct sk_buff * tail, int len)¶ add data to the tail of a potentially fragmented buffer
Parameters
struct sk_buff * skb- start of the buffer to use
struct sk_buff * tail- tail fragment of the buffer to use
int len- amount of data to add
Description
This function extends the used data area of the potentially fragmented buffer. tail must be the last fragment of skb – or skb itself. If this would exceed the total buffer size the kernel will panic. A pointer to the first byte of the extra data is returned.
Parameters
struct sk_buff * skb- buffer to use
unsigned int len- amount of data to add
Description
This function extends the used data area of the buffer. If this would exceed the total buffer size the kernel will panic. A pointer to the first byte of the extra data is returned.
Parameters
struct sk_buff * skb- buffer to use
unsigned int len- amount of data to add
Description
This function extends the used data area of the buffer at the buffer start. If this would exceed the total buffer headroom the kernel will panic. A pointer to the first byte of the extra data is returned.
Parameters
struct sk_buff * skb- buffer to use
unsigned int len- amount of data to remove
Description
This function removes data from the start of a buffer, returning the memory to the headroom. A pointer to the next data in the buffer is returned. Once the data has been pulled future pushes will overwrite the old data.
Parameters
struct sk_buff * skb- buffer to alter
unsigned int len- new length
Description
Cut the length of a buffer down by removing data from the tail. If the buffer is already under the length specified it is not modified. The skb must be linear.
Parameters
struct sk_buff * skb- buffer to reallocate
int delta- number of bytes to advance tail
Description
The function makes a sense only on a fragmented
sk_buff, it expands header moving its tail forward and copying necessary data from fragmented part.
sk_buffMUST have reference count of 1.Returns
NULL(andsk_buffdoes not change) if pull failed or value of new tail of skb in the case of success.All the pointers pointing into skb header may change and must be reloaded after call to this function.
-
int
skb_copy_bits(const struct sk_buff * skb, int offset, void * to, int len)¶ copy bits from skb to kernel buffer
Parameters
const struct sk_buff * skb- source skb
int offset- offset in source
void * to- destination buffer
int len- number of bytes to copy
Description
Copy the specified number of bytes from the source skb to the destination buffer.
- CAUTION ! :
- If its prototype is ever changed, check arch/{*}/net/{*}.S files, since it is called from BPF assembly code.
-
int
skb_store_bits(struct sk_buff * skb, int offset, const void * from, int len)¶ store bits from kernel buffer to skb
Parameters
struct sk_buff * skb- destination buffer
int offset- offset in destination
const void * from- source buffer
int len- number of bytes to copy
Description
Copy the specified number of bytes from the source buffer to the destination skb. This function handles all the messy bits of traversing fragment lists and such.
-
int
skb_zerocopy(struct sk_buff * to, struct sk_buff * from, int len, int hlen)¶ Zero copy skb to skb
Parameters
struct sk_buff * to- destination buffer
struct sk_buff * from- source buffer
int len- number of bytes to copy from source buffer
int hlen- size of linear headroom in destination buffer
Description
Copies up to len bytes from from to to by creating references to the frags in the source buffer.
The hlen as calculated by skb_zerocopy_headlen() specifies the headroom in the to buffer.
Return value: 0: everything is OK -ENOMEM: couldn’t orphan frags of from due to lack of memory -EFAULT:
skb_copy_bits()found some problem with skb geometry
Parameters
struct sk_buff_head * list- list to dequeue from
Description
Remove the head of the list. The list lock is taken so the function may be used safely with other locking list functions. The head item is returned orNULLif the list is empty.
Parameters
struct sk_buff_head * list- list to dequeue from
Description
Remove the tail of the list. The list lock is taken so the function may be used safely with other locking list functions. The tail item is returned orNULLif the list is empty.
-
void
skb_queue_purge(struct sk_buff_head * list)¶ empty a list
Parameters
struct sk_buff_head * list- list to empty
Description
Delete all buffers on ansk_bufflist. Each buffer is removed from the list and one reference dropped. This function takes the list lock and is atomic with respect to other list locking functions.
-
void
skb_queue_head(struct sk_buff_head * list, struct sk_buff * newsk)¶ queue a buffer at the list head
Parameters
struct sk_buff_head * list- list to use
struct sk_buff * newsk- buffer to queue
Description
Queue a buffer at the start of the list. This function takes the list lock and can be used safely with other locking
sk_bufffunctions safely.A buffer cannot be placed on two lists at the same time.
-
void
skb_queue_tail(struct sk_buff_head * list, struct sk_buff * newsk)¶ queue a buffer at the list tail
Parameters
struct sk_buff_head * list- list to use
struct sk_buff * newsk- buffer to queue
Description
Queue a buffer at the tail of the list. This function takes the list lock and can be used safely with other locking
sk_bufffunctions safely.A buffer cannot be placed on two lists at the same time.
Parameters
struct sk_buff * skb- buffer to remove
struct sk_buff_head * list- list to use
Description
Remove a packet from a list. The list locks are taken and this function is atomic with respect to other list locked calls
You must know what list the SKB is on.
-
void
skb_append(struct sk_buff * old, struct sk_buff * newsk, struct sk_buff_head * list)¶ append a buffer
Parameters
struct sk_buff * old- buffer to insert after
struct sk_buff * newsk- buffer to insert
struct sk_buff_head * list- list to use
Description
Place a packet after a given packet in a list. The list locks are taken and this function is atomic with respect to other list locked calls. A buffer cannot be placed on two lists at the same time.
-
void
skb_split(struct sk_buff * skb, struct sk_buff * skb1, const u32 len)¶ Split fragmented skb to two parts at length len.
Parameters
struct sk_buff * skb- the buffer to split
struct sk_buff * skb1- the buffer to receive the second part
const u32 len- new length for skb
-
void
skb_prepare_seq_read(struct sk_buff * skb, unsigned int from, unsigned int to, struct skb_seq_state * st)¶ Prepare a sequential read of skb data
Parameters
struct sk_buff * skb- the buffer to read
unsigned int from- lower offset of data to be read
unsigned int to- upper offset of data to be read
struct skb_seq_state * st- state variable
Description
Initializes the specified state variable. Must be called before
invoking skb_seq_read() for the first time.
-
unsigned int
skb_seq_read(unsigned int consumed, const u8 ** data, struct skb_seq_state * st)¶ Sequentially read skb data
Parameters
unsigned int consumed- number of bytes consumed by the caller so far
const u8 ** data- destination pointer for data to be returned
struct skb_seq_state * st- state variable
Description
Reads a block of skb data at consumed relative to the
lower offset specified to skb_prepare_seq_read(). Assigns
the head of the data block to data and returns the length
of the block or 0 if the end of the skb data or the upper
offset has been reached.
The caller is not required to consume all of the data
returned, i.e. consumed is typically set to the number
of bytes already consumed and the next call to
skb_seq_read() will return the remaining part of the block.
- Note 1: The size of each block of data returned can be arbitrary,
- this limitation is the cost for zerocopy sequential reads of potentially non linear data.
- Note 2: Fragment lists within fragments are not implemented
- at the moment, state->root_skb could be replaced with a stack for this purpose.
-
void
skb_abort_seq_read(struct skb_seq_state * st)¶ Abort a sequential read of skb data
Parameters
struct skb_seq_state * st- state variable
Description
Must be called if skb_seq_read() was not called until it
returned 0.
-
unsigned int
skb_find_text(struct sk_buff * skb, unsigned int from, unsigned int to, struct ts_config * config)¶ Find a text pattern in skb data
Parameters
struct sk_buff * skb- the buffer to look in
unsigned int from- search offset
unsigned int to- search limit
struct ts_config * config- textsearch configuration
Description
Finds a pattern in the skb data according to the specified
textsearch configuration. Use textsearch_next() to retrieve
subsequent occurrences of the pattern. Returns the offset
to the first occurrence or UINT_MAX if no match was found.
Parameters
struct sk_buff * skb- buffer to update
unsigned int len- length of data pulled
Description
This function performs an skb_pull on the packet and updates the CHECKSUM_COMPLETE checksum. It should be used on receive path processing instead of skb_pull unless you know that the checksum difference is zero (e.g., a valid IP header) or you are setting ip_summed to CHECKSUM_NONE.
-
struct sk_buff *
skb_segment(struct sk_buff * head_skb, netdev_features_t features)¶ Perform protocol segmentation on skb.
Parameters
struct sk_buff * head_skb- buffer to segment
netdev_features_t features- features for the output path (see dev->features)
Description
This function performs segmentation on the given skb. It returns a pointer to the first in a list of new skbs for the segments. In case of error it returns ERR_PTR(err).
-
int
skb_to_sgvec(struct sk_buff * skb, struct scatterlist * sg, int offset, int len)¶ Fill a scatter-gather list from a socket buffer
Parameters
struct sk_buff * skb- Socket buffer containing the buffers to be mapped
struct scatterlist * sg- The scatter-gather list to map into
int offset- The offset into the buffer’s contents to start mapping
int len- Length of buffer space to be mapped
Description
Fill the specified scatter-gather list with mappings/pointers into a region of the buffer space attached to a socket buffer. Returns either the number of scatterlist items used, or -EMSGSIZE if the contents could not fit.
-
int
skb_cow_data(struct sk_buff * skb, int tailbits, struct sk_buff ** trailer)¶ Check that a socket buffer’s data buffers are writable
Parameters
struct sk_buff * skb- The socket buffer to check.
int tailbits- Amount of trailing space to be added
struct sk_buff ** trailer- Returned pointer to the skb where the tailbits space begins
Description
Make sure that the data buffers attached to a socket buffer are writable. If they are not, private copies are made of the data buffers and the socket buffer is set to use these instead.
If tailbits is given, make sure that there is space to write tailbits bytes of data beyond current end of socket buffer. trailer will be set to point to the skb in which this space begins.
The number of scatterlist elements required to completely map the COW’d and extended socket buffer will be returned.
-
struct sk_buff *
skb_clone_sk(struct sk_buff * skb)¶ create clone of skb, and take reference to socket
Parameters
struct sk_buff * skb- the skb to clone
Description
This function creates a clone of a buffer that holds a reference on sk_refcnt. Buffers created via this function are meant to be returned using sock_queue_err_skb, or free via kfree_skb.
When passing buffers allocated with this function to sock_queue_err_skb it is necessary to wrap the call with sock_hold/sock_put in order to prevent the socket from being released prior to being enqueued on the sk_error_queue.
-
bool
skb_partial_csum_set(struct sk_buff * skb, u16 start, u16 off)¶ set up and verify partial csum values for packet
Parameters
struct sk_buff * skb- the skb to set
u16 start- the number of bytes after skb->data to start checksumming.
u16 off- the offset from start to place the checksum.
Description
For untrusted partially-checksummed packets, we need to make sure the values for skb->csum_start and skb->csum_offset are valid so we don’t oops.
This function checks and sets those values and skb->ip_summed: if this returns false you should drop the packet.
Parameters
struct sk_buff * skb- the skb to set up
bool recalculate- if true the pseudo-header checksum will be recalculated
-
struct sk_buff *
skb_checksum_trimmed(struct sk_buff * skb, unsigned int transport_len, __sum16(*skb_chkf) (struct sk_buff *skb)¶ validate checksum of an skb
Parameters
struct sk_buff * skb- the skb to check
unsigned int transport_len- the data length beyond the network header
__sum16(*)(struct sk_buff *skb) skb_chkf- checksum function to use
Description
Applies the given checksum function skb_chkf to the provided skb. Returns a checked and maybe trimmed skb. Returns NULL on error.
If the skb has data beyond the given transport length, then a trimmed & cloned skb is checked and returned.
Caller needs to set the skb transport header and free any returned skb if it differs from the provided skb.
-
bool
skb_try_coalesce(struct sk_buff * to, struct sk_buff * from, bool * fragstolen, int * delta_truesize)¶ try to merge skb to prior one
Parameters
struct sk_buff * to- prior buffer
struct sk_buff * from- buffer to add
bool * fragstolen- pointer to boolean
int * delta_truesize- how much more was allocated than was requested
Parameters
struct sk_buff * skb- buffer to clean
bool xnet- packet is crossing netns
Description
skb_scrub_packet can be used after encapsulating or decapsulting a packet into/from a tunnel. Some information have to be cleared during these operations. skb_scrub_packet can also be used to clean a skb before injecting it in another namespace (xnet == true). We have to clear all information in the skb that could impact namespace isolation.
-
bool
skb_gso_validate_network_len(const struct sk_buff * skb, unsigned int mtu)¶ Will a split GSO skb fit into a given MTU?
Parameters
const struct sk_buff * skb- GSO skb
unsigned int mtu- MTU to validate against
Description
skb_gso_validate_network_len validates if a given skb will fit a wanted MTU once split. It considers L3 headers, L4 headers, and the payload.
-
bool
skb_gso_validate_mac_len(const struct sk_buff * skb, unsigned int len)¶ Will a split GSO skb fit in a given length?
Parameters
const struct sk_buff * skb- GSO skb
unsigned int len- length to validate against
Description
skb_gso_validate_mac_len validates if a given skb will fit a wanted length once split, including L2, L3 and L4 headers and the payload.
-
int
skb_mpls_push(struct sk_buff * skb, __be32 mpls_lse, __be16 mpls_proto)¶ push a new MPLS header after the mac header
Parameters
struct sk_buff * skb- buffer
__be32 mpls_lse- MPLS label stack entry to push
__be16 mpls_proto- ethertype of the new MPLS header (expects 0x8847 or 0x8848)
Description
Expects skb->data at mac header.
Returns 0 on success, -errno otherwise.
Parameters
struct sk_buff * skb- buffer
__be16 next_proto- ethertype of header after popped MPLS header
Description
Expects skb->data at mac header.
Returns 0 on success, -errno otherwise.
-
int
skb_mpls_update_lse(struct sk_buff * skb, __be32 mpls_lse)¶ modify outermost MPLS header and update csum
Parameters
struct sk_buff * skb- buffer
__be32 mpls_lse- new MPLS label stack entry to update to
Description
Expects skb->data at mac header.
Returns 0 on success, -errno otherwise.
Parameters
struct sk_buff * skb- buffer
Description
Expects skb->data at mac header.
Returns 0 on success, -errno otherwise.
-
struct sk_buff *
alloc_skb_with_frags(unsigned long header_len, unsigned long data_len, int max_page_order, int * errcode, gfp_t gfp_mask)¶ allocate skb with page frags
Parameters
unsigned long header_len- size of linear part
unsigned long data_len- needed length in frags
int max_page_order- max page order desired.
int * errcode- pointer to error code if any
gfp_t gfp_mask- allocation mask
Description
This can be used to allocate a paged skb, given a maximal order for frags.
-
void *
skb_ext_add(struct sk_buff * skb, enum skb_ext_id id)¶ allocate space for given extension, COW if needed
Parameters
struct sk_buff * skb- buffer
enum skb_ext_id id- extension to allocate space for
Description
Allocates enough space for the given extension. If the extension is already present, a pointer to that extension is returned.
If the skb was cloned, COW applies and the returned memory can be modified without changing the extension space of clones buffers.
Returns pointer to the extension or NULL on allocation failure.
-
bool
sk_ns_capable(const struct sock * sk, struct user_namespace * user_ns, int cap)¶ General socket capability test
Parameters
const struct sock * sk- Socket to use a capability on or through
struct user_namespace * user_ns- The user namespace of the capability to use
int cap- The capability to use
Description
Test to see if the opener of the socket had when the socket was created and the current process has the capability cap in the user namespace user_ns.
Parameters
const struct sock * sk- Socket to use a capability on or through
int cap- The global capability to use
Description
Test to see if the opener of the socket had when the socket was created and the current process has the capability cap in all user namespaces.
Parameters
const struct sock * sk- Socket to use a capability on or through
int cap- The capability to use
Description
Test to see if the opener of the socket had when the socket was created and the current process has the capability cap over the network namespace the socket is a member of.
Parameters
struct sock * sk- socket to set it on
Description
Set SOCK_MEMALLOC on a socket for access to emergency reserves.
It’s the responsibility of the admin to adjust min_free_kbytes
to meet the requirements
-
struct sock *
sk_alloc(struct net * net, int family, gfp_t priority, struct proto * prot, int kern)¶ All socket objects are allocated here
Parameters
struct net * net- the applicable net namespace
int family- protocol family
gfp_t priority- for allocation (
GFP_KERNEL,GFP_ATOMIC, etc) struct proto * prot- struct proto associated with this new sock instance
int kern- is this to be a kernel socket?
-
struct sock *
sk_clone_lock(const struct sock * sk, const gfp_t priority)¶ clone a socket, and lock its clone
Parameters
const struct sock * sk- the socket to clone
const gfp_t priority- for allocation (
GFP_KERNEL,GFP_ATOMIC, etc)
Description
Caller must unlock socket even in error path (bh_unlock_sock(newsk))
-
bool
skb_page_frag_refill(unsigned int sz, struct page_frag * pfrag, gfp_t gfp)¶ check that a page_frag contains enough room
Parameters
unsigned int sz- minimum size of the fragment we want to get
struct page_frag * pfrag- pointer to page_frag
gfp_t gfp- priority for memory allocation
Note
While this allocator tries to use high order pages, there is no guarantee that allocations succeed. Therefore, sz MUST be less or equal than PAGE_SIZE.
-
int
sk_wait_data(struct sock * sk, long * timeo, const struct sk_buff * skb)¶ wait for data to arrive at sk_receive_queue
Parameters
struct sock * sk- sock to wait on
long * timeo- for how long
const struct sk_buff * skb- last skb seen on sk_receive_queue
Description
Now socket state including sk->sk_err is changed only under lock, hence we may omit checks after joining wait queue. We check receive queue before schedule() only as optimization; it is very likely that release_sock() added new data.
-
int
__sk_mem_raise_allocated(struct sock * sk, int size, int amt, int kind)¶ increase memory_allocated
Parameters
struct sock * sk- socket
int size- memory size to allocate
int amt- pages to allocate
int kind- allocation type
Description
Similar to__sk_mem_schedule(), but does not update sk_forward_alloc
-
int
__sk_mem_schedule(struct sock * sk, int size, int kind)¶ increase sk_forward_alloc and memory_allocated
Parameters
struct sock * sk- socket
int size- memory size to allocate
int kind- allocation type
Description
If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means rmem allocation. This function assumes that protocols which have memory_pressure use sk_wmem_queued as write buffer accounting.
Parameters
struct sock * sk- socket
int amount- number of quanta
Description
Similar to__sk_mem_reclaim(), but does not update sk_forward_alloc
Parameters
struct sock * sk- socket
int amount- number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
Parameters
struct sock * sk- socket
Description
This version should be used for very small section, where process wont block return false if fast path is taken:
sk_lock.slock locked, owned = 0, BH disabled
return true if slow path is taken:
sk_lock.slock unlocked, owned = 1, BH enabled
-
struct sk_buff *
__skb_try_recv_datagram(struct sock * sk, unsigned int flags, void (*destructor) (struct sock *sk, struct sk_buff *skb, int * off, int * err, struct sk_buff ** last)¶ Receive a datagram skbuff
Parameters
struct sock * sk- socket
unsigned int flags- MSG_ flags
void (*)(struct sock *sk, struct sk_buff *skb) destructor- invoked under the receive lock on successful dequeue
int * off- an offset in bytes to peek skb from. Returns an offset within an skb where data actually starts
int * err- error code returned
struct sk_buff ** last- set to last peeked message to inform the wait function what to look for when peeking
Description
Get a datagram skbuff, understands the peeking, nonblocking wakeups and possible races. This replaces identical code in packet, raw and udp, as well as the IPX AX.25 and Appletalk. It also finally fixes the long standing peek and read race for datagram sockets. If you alter this routine remember it must be re-entrant.
This function will lock the socket if a skb is returned, so the caller needs to unlock the socket in that case (usually by calling skb_free_datagram). Returns NULL with err set to -EAGAIN if no data was available or to some other value if an error was detected.
- It does not lock socket since today. This function is
- free of race conditions. This measure should/can improve
- significantly datagram socket latencies at high loads,
- when data copying to user space takes lots of time.
- (BTW I’ve just killed the last cli() in IP/IPv6/core/netlink/packet
- Great win.)
- –ANK (980729)
The order of the tests when we find no data waiting are specified quite explicitly by POSIX 1003.1g, don’t change them without having the standard around please.
-
int
skb_kill_datagram(struct sock * sk, struct sk_buff * skb, unsigned int flags)¶ Free a datagram skbuff forcibly
Parameters
struct sock * sk- socket
struct sk_buff * skb- datagram skbuff
unsigned int flags- MSG_ flags
Description
This function frees a datagram skbuff that was received by skb_recv_datagram. The flags argument must match the one used for skb_recv_datagram.
If the MSG_PEEK flag is set, and the packet is still on the receive queue of the socket, it will be taken off the queue before it is freed.
This function currently only disables BH when acquiring the sk_receive_queue lock. Therefore it must not be used in a context where that lock is acquired in an IRQ context.
It returns 0 if the packet was removed by us.
-
int
skb_copy_and_hash_datagram_iter(const struct sk_buff * skb, int offset, struct iov_iter * to, int len, struct ahash_request * hash)¶ Copy datagram to an iovec iterator and update a hash.
Parameters
const struct sk_buff * skb- buffer to copy
int offset- offset in the buffer to start copying from
struct iov_iter * to- iovec iterator to copy to
int len- amount of data to copy from buffer to iovec
struct ahash_request * hash- hash request to update
-
int
skb_copy_datagram_iter(const struct sk_buff * skb, int offset, struct iov_iter * to, int len)¶ Copy a datagram to an iovec iterator.
Parameters
const struct sk_buff * skb- buffer to copy
int offset- offset in the buffer to start copying from
struct iov_iter * to- iovec iterator to copy to
int len- amount of data to copy from buffer to iovec
-
int
skb_copy_datagram_from_iter(struct sk_buff * skb, int offset, struct iov_iter * from, int len)¶ Copy a datagram from an iov_iter.
Parameters
struct sk_buff * skb- buffer to copy
int offset- offset in the buffer to start copying to
struct iov_iter * from- the copy source
int len- amount of data to copy to buffer from iovec
Description
Returns 0 or -EFAULT.
-
int
zerocopy_sg_from_iter(struct sk_buff * skb, struct iov_iter * from)¶ Build a zerocopy datagram from an iov_iter
Parameters
struct sk_buff * skb- buffer to copy
struct iov_iter * from- the source to copy from
Description
The function will first copy up to headlen, and then pin the userspace pages and build frags through them.
Returns 0, -EFAULT or -EMSGSIZE.
-
int
skb_copy_and_csum_datagram_msg(struct sk_buff * skb, int hlen, struct msghdr * msg)¶ Copy and checksum skb to user iovec.
Parameters
struct sk_buff * skb- skbuff
int hlen- hardware length
struct msghdr * msg- destination
Description
Caller _must_ check that skb will fit to this iovec.
Return
- 0 - success.
- -EINVAL - checksum failure. -EFAULT - fault during copy.
-
__poll_t
datagram_poll(struct file * file, struct socket * sock, poll_table * wait)¶ generic datagram poll
Parameters
struct file * file- file struct
struct socket * sock- socket
poll_table * wait- poll table
Description
Datagram poll: Again totally generic. This also handles sequenced packet sockets providing the socket receive queue is only ever holding data ready to receive.
Note
- when you don’t use this routine for this protocol,
- and you use a different write policy from sock_writeable() then please supply your own write_space callback.
-
int
sk_stream_wait_connect(struct sock * sk, long * timeo_p)¶ Wait for a socket to get into the connected state
Parameters
struct sock * sk- sock to wait on
long * timeo_p- for how long to wait
Description
Must be called with the socket locked.
Parameters
struct sock * sk- socket to wait for memory
long * timeo_p- for how long
Socket Filter¶
-
int
sk_filter_trim_cap(struct sock * sk, struct sk_buff * skb, unsigned int cap)¶ run a packet through a socket filter
Parameters
struct sock * sk- sock associated with
sk_buff struct sk_buff * skb- buffer to filter
unsigned int cap- limit on how short the eBPF program may trim the packet
Description
Run the eBPF program and then cut skb->data to correct size returned by the program. If pkt_len is 0 we toss packet. If skb->len is smaller than pkt_len we keep whole skb->data. This is the socket level wrapper to BPF_PROG_RUN. It returns 0 if the packet should be accepted or -EPERM if the packet should be tossed.
-
int
bpf_prog_create(struct bpf_prog ** pfp, struct sock_fprog_kern * fprog)¶ create an unattached filter
Parameters
struct bpf_prog ** pfp- the unattached filter that is created
struct sock_fprog_kern * fprog- the filter program
Description
Create a filter independent of any socket. We first run some sanity checks on it to make sure it does not explode on us later. If an error occurs or there is insufficient memory for the filter a negative errno code is returned. On success the return is zero.
-
int
bpf_prog_create_from_user(struct bpf_prog ** pfp, struct sock_fprog * fprog, bpf_aux_classic_check_t trans, bool save_orig)¶ create an unattached filter from user buffer
Parameters
struct bpf_prog ** pfp- the unattached filter that is created
struct sock_fprog * fprog- the filter program
bpf_aux_classic_check_t trans- post-classic verifier transformation handler
bool save_orig- save classic BPF program
Description
This function effectively does the same as bpf_prog_create(), only
that it builds up its insns buffer from user space provided buffer.
It also allows for passing a bpf_aux_classic_check_t handler.
Parameters
struct sock_fprog * fprog- the filter program
struct sock * sk- the socket to use
Description
Attach the user’s filter code. We first run some sanity checks on it to make sure it does not explode on us later. If an error occurs or there is insufficient memory for the filter a negative errno code is returned. On success the return is zero.
Generic Network Statistics¶
-
struct
gnet_stats_basic¶ byte/packet throughput statistics
Definition
struct gnet_stats_basic {
__u64 bytes;
__u32 packets;
};
Members
bytes- number of seen bytes
packets- number of seen packets
-
struct
gnet_stats_rate_est¶ rate estimator
Definition
struct gnet_stats_rate_est {
__u32 bps;
__u32 pps;
};
Members
bps- current byte rate
pps- current packet rate
-
struct
gnet_stats_rate_est64¶ rate estimator
Definition
struct gnet_stats_rate_est64 {
__u64 bps;
__u64 pps;
};
Members
bps- current byte rate
pps- current packet rate
-
struct
gnet_stats_queue¶ queuing statistics
Definition
struct gnet_stats_queue {
__u32 qlen;
__u32 backlog;
__u32 drops;
__u32 requeues;
__u32 overlimits;
};
Members
qlen- queue length
backlog- backlog size of queue
drops- number of dropped packets
requeues- number of requeues
overlimits- number of enqueues over the limit
-
struct
gnet_estimator¶ rate estimator configuration
Definition
struct gnet_estimator {
signed char interval;
unsigned char ewma_log;
};
Members
interval- sampling period
ewma_log- the log of measurement window weight
-
int
gnet_stats_start_copy_compat(struct sk_buff * skb, int type, int tc_stats_type, int xstats_type, spinlock_t * lock, struct gnet_dump * d, int padattr)¶ start dumping procedure in compatibility mode
Parameters
struct sk_buff * skb- socket buffer to put statistics TLVs into
int type- TLV type for top level statistic TLV
int tc_stats_type- TLV type for backward compatibility struct tc_stats TLV
int xstats_type- TLV type for backward compatibility xstats TLV
spinlock_t * lock- statistics lock
struct gnet_dump * d- dumping handle
int padattr- padding attribute
Description
Initializes the dumping handle, grabs the statistic lock and appends an empty TLV header to the socket buffer for use a container for all other statistic TLVS.
The dumping handle is marked to be in backward compatibility mode telling all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
-
int
gnet_stats_start_copy(struct sk_buff * skb, int type, spinlock_t * lock, struct gnet_dump * d, int padattr)¶ start dumping procedure in compatibility mode
Parameters
struct sk_buff * skb- socket buffer to put statistics TLVs into
int type- TLV type for top level statistic TLV
spinlock_t * lock- statistics lock
struct gnet_dump * d- dumping handle
int padattr- padding attribute
Description
Initializes the dumping handle, grabs the statistic lock and appends an empty TLV header to the socket buffer for use a container for all other statistic TLVS.
Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
-
int
gnet_stats_copy_basic(const seqcount_t * running, struct gnet_dump * d, struct gnet_stats_basic_cpu __percpu * cpu, struct gnet_stats_basic_packed * b)¶ copy basic statistics into statistic TLV
Parameters
const seqcount_t * running- seqcount_t pointer
struct gnet_dump * d- dumping handle
struct gnet_stats_basic_cpu __percpu * cpu- copy statistic per cpu
struct gnet_stats_basic_packed * b- basic statistics
Description
Appends the basic statistics to the top level TLV created by
gnet_stats_start_copy().
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gnet_stats_copy_basic_hw(const seqcount_t * running, struct gnet_dump * d, struct gnet_stats_basic_cpu __percpu * cpu, struct gnet_stats_basic_packed * b)¶ copy basic hw statistics into statistic TLV
Parameters
const seqcount_t * running- seqcount_t pointer
struct gnet_dump * d- dumping handle
struct gnet_stats_basic_cpu __percpu * cpu- copy statistic per cpu
struct gnet_stats_basic_packed * b- basic statistics
Description
Appends the basic statistics to the top level TLV created by
gnet_stats_start_copy().
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gnet_stats_copy_rate_est(struct gnet_dump * d, struct net_rate_estimator __rcu ** rate_est)¶ copy rate estimator statistics into statistics TLV
Parameters
struct gnet_dump * d- dumping handle
struct net_rate_estimator __rcu ** rate_est- rate estimator
Description
Appends the rate estimator statistics to the top level TLV created by
gnet_stats_start_copy().
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gnet_stats_copy_queue(struct gnet_dump * d, struct gnet_stats_queue __percpu * cpu_q, struct gnet_stats_queue * q, __u32 qlen)¶ copy queue statistics into statistics TLV
Parameters
struct gnet_dump * d- dumping handle
struct gnet_stats_queue __percpu * cpu_q- per cpu queue statistics
struct gnet_stats_queue * q- queue statistics
__u32 qlen- queue length statistics
Description
Appends the queue statistics to the top level TLV created by
gnet_stats_start_copy(). Using per cpu queue statistics if
they are available.
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gnet_stats_copy_app(struct gnet_dump * d, void * st, int len)¶ copy application specific statistics into statistics TLV
Parameters
struct gnet_dump * d- dumping handle
void * st- application specific statistics data
int len- length of data
Description
Appends the application specific statistics to the top level TLV created by
gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
handle is in backward compatibility mode.
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gnet_stats_finish_copy(struct gnet_dump * d)¶ finish dumping procedure
Parameters
struct gnet_dump * d- dumping handle
Description
Corrects the length of the top level TLV to include all TLVs added
by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
if gnet_stats_start_copy_compat() was used and releases the statistics
lock.
Returns 0 on success or -1 with the statistic lock released if the room in the socket buffer was not sufficient.
-
int
gen_new_estimator(struct gnet_stats_basic_packed * bstats, struct gnet_stats_basic_cpu __percpu * cpu_bstats, struct net_rate_estimator __rcu ** rate_est, spinlock_t * lock, seqcount_t * running, struct nlattr * opt)¶ create a new rate estimator
Parameters
struct gnet_stats_basic_packed * bstats- basic statistics
struct gnet_stats_basic_cpu __percpu * cpu_bstats- bstats per cpu
struct net_rate_estimator __rcu ** rate_est- rate estimator statistics
spinlock_t * lock- lock for statistics and control path
seqcount_t * running- qdisc running seqcount
struct nlattr * opt- rate estimator configuration TLV
Description
Creates a new rate estimator with bstats as source and rate_est
as destination. A new timer with the interval specified in the
configuration TLV is created. Upon each interval, the latest statistics
will be read from bstats and the estimated rate will be stored in
rate_est with the statistics lock grabbed during this period.
Returns 0 on success or a negative error code.
-
void
gen_kill_estimator(struct net_rate_estimator __rcu ** rate_est)¶ remove a rate estimator
Parameters
struct net_rate_estimator __rcu ** rate_est- rate estimator
Description
Removes the rate estimator.
-
int
gen_replace_estimator(struct gnet_stats_basic_packed * bstats, struct gnet_stats_basic_cpu __percpu * cpu_bstats, struct net_rate_estimator __rcu ** rate_est, spinlock_t * lock, seqcount_t * running, struct nlattr * opt)¶ replace rate estimator configuration
Parameters
struct gnet_stats_basic_packed * bstats- basic statistics
struct gnet_stats_basic_cpu __percpu * cpu_bstats- bstats per cpu
struct net_rate_estimator __rcu ** rate_est- rate estimator statistics
spinlock_t * lock- lock for statistics and control path
seqcount_t * running- qdisc running seqcount (might be NULL)
struct nlattr * opt- rate estimator configuration TLV
Description
Replaces the configuration of a rate estimator by calling
gen_kill_estimator() and gen_new_estimator().
Returns 0 on success or a negative error code.
-
bool
gen_estimator_active(struct net_rate_estimator __rcu ** rate_est)¶ test if estimator is currently in use
Parameters
struct net_rate_estimator __rcu ** rate_est- rate estimator
Description
Returns true if estimator is active, and false if not.
SUN RPC subsystem¶
-
__be32 *
xdr_encode_opaque_fixed(__be32 * p, const void * ptr, unsigned int nbytes)¶ Encode fixed length opaque data
Parameters
__be32 * p- pointer to current position in XDR buffer.
const void * ptr- pointer to data to encode (or NULL)
unsigned int nbytes- size of data.
Description
Copy the array of data of length nbytes at ptr to the XDR buffer at position p, then align to the next 32-bit boundary by padding with zero bytes (see RFC1832).
Note
if ptr is NULL, only the padding is performed.
Returns the updated current XDR buffer position
-
__be32 *
xdr_encode_opaque(__be32 * p, const void * ptr, unsigned int nbytes)¶ Encode variable length opaque data
Parameters
__be32 * p- pointer to current position in XDR buffer.
const void * ptr- pointer to data to encode (or NULL)
unsigned int nbytes- size of data.
Description
Returns the updated current XDR buffer position
-
void
xdr_terminate_string(struct xdr_buf * buf, const u32 len)¶ ‘0’-terminate a string residing in an xdr_buf
Parameters
struct xdr_buf * buf- XDR buffer where string resides
const u32 len- length of string, in bytes
-
void
xdr_inline_pages(struct xdr_buf * xdr, unsigned int offset, struct page ** pages, unsigned int base, unsigned int len)¶ Prepare receive buffer for a large reply
Parameters
struct xdr_buf * xdr- xdr_buf into which reply will be placed
unsigned int offset- expected offset where data payload will start, in bytes
struct page ** pages- vector of struct page pointers
unsigned int base- offset in first page where receive should start, in bytes
unsigned int len- expected size of the upper layer data payload, in bytes
-
void
_copy_from_pages(char * p, struct page ** pages, size_t pgbase, size_t len)¶
Parameters
char * p- pointer to destination
struct page ** pages- array of pages
size_t pgbase- offset of source data
size_t len- length
Description
Copies data into an arbitrary memory location from an array of pages The copy is assumed to be non-overlapping.
-
unsigned int
xdr_stream_pos(const struct xdr_stream * xdr)¶ Return the current offset from the start of the xdr_stream
Parameters
const struct xdr_stream * xdr- pointer to struct xdr_stream
-
void
xdr_init_encode(struct xdr_stream * xdr, struct xdr_buf * buf, __be32 * p, struct rpc_rqst * rqst)¶ Initialize a struct xdr_stream for sending data.
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
struct xdr_buf * buf- pointer to XDR buffer in which to encode data
__be32 * p- current pointer inside XDR buffer
struct rpc_rqst * rqst- pointer to controlling rpc_rqst, for debugging
Note
- at the moment the RPC client only passes the length of our
- scratch buffer in the xdr_buf’s header kvec. Previously this meant we needed to call xdr_adjust_iovec() after encoding the data. With the new scheme, the xdr_stream manages the details of the buffer length, and takes care of adjusting the kvec length for us.
-
void
xdr_commit_encode(struct xdr_stream * xdr)¶ Ensure all data is written to buffer
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
Description
We handle encoding across page boundaries by giving the caller a temporary location to write to, then later copying the data into place; xdr_commit_encode does that copying.
Normally the caller doesn’t need to call this directly, as the following xdr_reserve_space will do it. But an explicit call may be required at the end of encoding, or any other time when the xdr_buf data might be read.
-
__be32 *
xdr_reserve_space(struct xdr_stream * xdr, size_t nbytes)¶ Reserve buffer space for sending
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
size_t nbytes- number of bytes to reserve
Description
Checks that we have enough buffer space to encode ‘nbytes’ more bytes of data. If so, update the total xdr_buf length, and adjust the length of the current kvec.
-
void
xdr_truncate_encode(struct xdr_stream * xdr, size_t len)¶ truncate an encode buffer
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
size_t len- new length of buffer
Description
Truncates the xdr stream, so that xdr->buf->len == len, and xdr->p points at offset len from the start of the buffer, and head, tail, and page lengths are adjusted to correspond.
If this means moving xdr->p to a different buffer, we assume that that the end pointer should be set to the end of the current page, except in the case of the head buffer when we assume the head buffer’s current length represents the end of the available buffer.
This is not safe to use on a buffer that already has inlined page cache pages (as in a zero-copy server read reply), except for the simple case of truncating from one position in the tail to another.
-
int
xdr_restrict_buflen(struct xdr_stream * xdr, int newbuflen)¶ decrease available buffer space
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
int newbuflen- new maximum number of bytes available
Description
Adjust our idea of how much space is available in the buffer. If we’ve already used too much space in the buffer, returns -1. If the available space is already smaller than newbuflen, returns 0 and does nothing. Otherwise, adjusts xdr->buf->buflen to newbuflen and ensures xdr->end is set at most offset newbuflen from the start of the buffer.
-
void
xdr_write_pages(struct xdr_stream * xdr, struct page ** pages, unsigned int base, unsigned int len)¶ Insert a list of pages into an XDR buffer for sending
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
struct page ** pages- list of pages
unsigned int base- offset of first byte
unsigned int len- length of data in bytes
-
void
xdr_init_decode(struct xdr_stream * xdr, struct xdr_buf * buf, __be32 * p, struct rpc_rqst * rqst)¶ Initialize an xdr_stream for decoding data.
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
struct xdr_buf * buf- pointer to XDR buffer from which to decode data
__be32 * p- current pointer inside XDR buffer
struct rpc_rqst * rqst- pointer to controlling rpc_rqst, for debugging
-
void
xdr_init_decode_pages(struct xdr_stream * xdr, struct xdr_buf * buf, struct page ** pages, unsigned int len)¶ Initialize an xdr_stream for decoding into pages
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
struct xdr_buf * buf- pointer to XDR buffer from which to decode data
struct page ** pages- list of pages to decode into
unsigned int len- length in bytes of buffer in pages
-
void
xdr_set_scratch_buffer(struct xdr_stream * xdr, void * buf, size_t buflen)¶ Attach a scratch buffer for decoding data.
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
void * buf- pointer to an empty buffer
size_t buflen- size of ‘buf’
Description
The scratch buffer is used when decoding from an array of pages.
If an xdr_inline_decode() call spans across page boundaries, then
we copy the data into the scratch buffer in order to allow linear
access.
-
__be32 *
xdr_inline_decode(struct xdr_stream * xdr, size_t nbytes)¶ Retrieve XDR data to decode
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
size_t nbytes- number of bytes of data to decode
Description
Check if the input buffer is long enough to enable us to decode ‘nbytes’ more bytes of data starting at the current position. If so return the current pointer, then update the current pointer position.
-
unsigned int
xdr_read_pages(struct xdr_stream * xdr, unsigned int len)¶ Ensure page-based XDR data to decode is aligned at current pointer position
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
unsigned int len- number of bytes of page data
Description
Moves data beyond the current pointer position from the XDR head[] buffer into the page list. Any data that lies beyond current position + “len” bytes is moved into the XDR tail[].
Returns the number of XDR encoded bytes now contained in the pages
-
void
xdr_enter_page(struct xdr_stream * xdr, unsigned int len)¶ decode data from the XDR page
Parameters
struct xdr_stream * xdr- pointer to xdr_stream struct
unsigned int len- number of bytes of page data
Description
Moves data beyond the current pointer position from the XDR head[] buffer into the page list. Any data that lies beyond current position + “len” bytes is moved into the XDR tail[]. The current pointer is then repositioned at the beginning of the first XDR page.
-
int
xdr_buf_subsegment(struct xdr_buf * buf, struct xdr_buf * subbuf, unsigned int base, unsigned int len)¶ set subbuf to a portion of buf
Parameters
struct xdr_buf * buf- an xdr buffer
struct xdr_buf * subbuf- the result buffer
unsigned int base- beginning of range in bytes
unsigned int len- length of range in bytes
Description
sets subbuf to an xdr buffer representing the portion of buf of length len starting at offset base.
buf and subbuf may be pointers to the same struct xdr_buf.
Returns -1 if base of length are out of bounds.
-
ssize_t
xdr_stream_decode_opaque(struct xdr_stream * xdr, void * ptr, size_t size)¶ Decode variable length opaque
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
void * ptr- location to store opaque data
size_t size- size of storage buffer ptr
Description
- Return values:
- On success, returns size of object stored in *ptr
-EBADMSGon XDR buffer overflow-EMSGSIZEon overflow of storage buffer ptr
-
ssize_t
xdr_stream_decode_opaque_dup(struct xdr_stream * xdr, void ** ptr, size_t maxlen, gfp_t gfp_flags)¶ Decode and duplicate variable length opaque
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
void ** ptr- location to store pointer to opaque data
size_t maxlen- maximum acceptable object size
gfp_t gfp_flags- GFP mask to use
Description
- Return values:
- On success, returns size of object stored in *ptr
-EBADMSGon XDR buffer overflow-EMSGSIZEif the size of the object would exceed maxlen-ENOMEMon memory allocation failure
-
ssize_t
xdr_stream_decode_string(struct xdr_stream * xdr, char * str, size_t size)¶ Decode variable length string
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
char * str- location to store string
size_t size- size of storage buffer str
Description
- Return values:
- On success, returns length of NUL-terminated string stored in *str
-EBADMSGon XDR buffer overflow-EMSGSIZEon overflow of storage buffer str
-
ssize_t
xdr_stream_decode_string_dup(struct xdr_stream * xdr, char ** str, size_t maxlen, gfp_t gfp_flags)¶ Decode and duplicate variable length string
Parameters
struct xdr_stream * xdr- pointer to xdr_stream
char ** str- location to store pointer to string
size_t maxlen- maximum acceptable string length
gfp_t gfp_flags- GFP mask to use
Description
- Return values:
- On success, returns length of NUL-terminated string stored in *ptr
-EBADMSGon XDR buffer overflow-EMSGSIZEif the size of the string would exceed maxlen-ENOMEMon memory allocation failure
-
char *
svc_print_addr(struct svc_rqst * rqstp, char * buf, size_t len)¶ Format rq_addr field for printing
Parameters
struct svc_rqst * rqstp- svc_rqst struct containing address to print
char * buf- target buffer for formatted address
size_t len- length of target buffer
-
void
svc_reserve(struct svc_rqst * rqstp, int space)¶ change the space reserved for the reply to a request.
Parameters
struct svc_rqst * rqstp- The request in question
int space- new max space to reserve
Description
Each request reserves some space on the output queue of the transport to make sure the reply fits. This function reduces that reserved space to be the amount of space used already, plus space.
-
struct svc_xprt *
svc_find_xprt(struct svc_serv * serv, const char * xcl_name, struct net * net, const sa_family_t af, const unsigned short port)¶ find an RPC transport instance
Parameters
struct svc_serv * serv- pointer to svc_serv to search
const char * xcl_name- C string containing transport’s class name
struct net * net- owner net pointer
const sa_family_t af- Address family of transport’s local address
const unsigned short port- transport’s IP port number
Description
Return the transport instance pointer for the endpoint accepting connections/peer traffic from the specified transport class, address family and port.
Specifying 0 for the address family or port is effectively a wild-card, and will result in matching the first transport in the service’s list that has a matching class name.
-
int
svc_xprt_names(struct svc_serv * serv, char * buf, const int buflen)¶ format a buffer with a list of transport names
Parameters
struct svc_serv * serv- pointer to an RPC service
char * buf- pointer to a buffer to be filled in
const int buflen- length of buffer to be filled in
Description
Fills in buf with a string containing a list of transport names, each name terminated with ‘n’.
Returns positive length of the filled-in string on success; otherwise a negative errno value is returned if an error occurs.
-
int
xprt_register_transport(struct xprt_class * transport)¶ register a transport implementation
Parameters
struct xprt_class * transport- transport to register
Description
If a transport implementation is loaded as a kernel module, it can call this interface to make itself known to the RPC client.
Return
0: transport successfully registered -EEXIST: transport already registered -EINVAL: transport module being unloaded
-
int
xprt_unregister_transport(struct xprt_class * transport)¶ unregister a transport implementation
Parameters
struct xprt_class * transport- transport to unregister
Return
0: transport successfully unregistered -ENOENT: transport never registered
-
int
xprt_load_transport(const char * transport_name)¶ load a transport implementation
Parameters
const char * transport_name- transport to load
Return
0: transport successfully loaded -ENOENT: transport module not available
-
int
xprt_reserve_xprt(struct rpc_xprt * xprt, struct rpc_task * task)¶ serialize write access to transports
Parameters
struct rpc_xprt * xprt- pointer to the target transport
struct rpc_task * task- task that is requesting access to the transport
Description
This prevents mixing the payload of separate requests, and prevents transport connects from colliding with writes. No congestion control is provided.
-
void
xprt_release_xprt(struct rpc_xprt * xprt, struct rpc_task * task)¶ allow other requests to use a transport
Parameters
struct rpc_xprt * xprt- transport with other tasks potentially waiting
struct rpc_task * task- task that is releasing access to the transport
Description
Note that “task” can be NULL. No congestion control is provided.
-
void
xprt_release_xprt_cong(struct rpc_xprt * xprt, struct rpc_task * task)¶ allow other requests to use a transport
Parameters
struct rpc_xprt * xprt- transport with other tasks potentially waiting
struct rpc_task * task- task that is releasing access to the transport
Description
Note that “task” can be NULL. Another task is awoken to use the transport if the transport’s congestion window allows it.
-
bool
xprt_request_get_cong(struct rpc_xprt * xprt, struct rpc_rqst * req)¶ Request congestion control credits
Parameters
struct rpc_xprt * xprt- pointer to transport
struct rpc_rqst * req- pointer to RPC request
Description
Useful for transports that require congestion control.
-
void
xprt_release_rqst_cong(struct rpc_task * task)¶ housekeeping when request is complete
Parameters
struct rpc_task * task- RPC request that recently completed
Description
Useful for transports that require congestion control.
-
void
xprt_adjust_cwnd(struct rpc_xprt * xprt, struct rpc_task * task, int result)¶ adjust transport congestion window
Parameters
struct rpc_xprt * xprt- pointer to xprt
struct rpc_task * task- recently completed RPC request used to adjust window
int result- result code of completed RPC request
Description
The transport code maintains an estimate on the maximum number of out- standing RPC requests, using a smoothed version of the congestion avoidance implemented in 44BSD. This is basically the Van Jacobson congestion algorithm: If a retransmit occurs, the congestion window is halved; otherwise, it is incremented by 1/cwnd when
- a reply is received and
- a full number of requests are outstanding and
- the congestion window hasn’t been updated recently.
-
void
xprt_wake_pending_tasks(struct rpc_xprt * xprt, int status)¶ wake all tasks on a transport’s pending queue
Parameters
struct rpc_xprt * xprt- transport with waiting tasks
int status- result code to plant in each task before waking it
-
void
xprt_wait_for_buffer_space(struct rpc_xprt * xprt)¶ wait for transport output buffer to clear
Parameters
struct rpc_xprt * xprt- transport
Description
Note that we only set the timer for the case of RPC_IS_SOFT(), since we don’t in general want to force a socket disconnection due to an incomplete RPC call transmission.
-
bool
xprt_write_space(struct rpc_xprt * xprt)¶ wake the task waiting for transport output buffer space
Parameters
struct rpc_xprt * xprt- transport with waiting tasks
Description
Can be called in a soft IRQ context, so xprt_write_space never sleeps.
-
void
xprt_disconnect_done(struct rpc_xprt * xprt)¶ mark a transport as disconnected
Parameters
struct rpc_xprt * xprt- transport to flag for disconnect
-
void
xprt_force_disconnect(struct rpc_xprt * xprt)¶ force a transport to disconnect
Parameters
struct rpc_xprt * xprt- transport to disconnect
-
unsigned long
xprt_reconnect_delay(const struct rpc_xprt * xprt)¶ compute the wait before scheduling a connect
Parameters
const struct rpc_xprt * xprt- transport instance
-
void
xprt_reconnect_backoff(struct rpc_xprt * xprt, unsigned long init_to)¶ compute the new re-establish timeout
Parameters
struct rpc_xprt * xprt- transport instance
unsigned long init_to- initial reestablish timeout
-
struct rpc_rqst *
xprt_lookup_rqst(struct rpc_xprt * xprt, __be32 xid)¶ find an RPC request corresponding to an XID
Parameters
struct rpc_xprt * xprt- transport on which the original request was transmitted
__be32 xid- RPC XID of incoming reply
Description
Caller holds xprt->queue_lock.
-
void
xprt_pin_rqst(struct rpc_rqst * req)¶ Pin a request on the transport receive list
Parameters
struct rpc_rqst * req- Request to pin
Description
Caller must ensure this is atomic with the call to xprt_lookup_rqst()
so should be holding xprt->queue_lock.
-
void
xprt_unpin_rqst(struct rpc_rqst * req)¶ Unpin a request on the transport receive list
Parameters
struct rpc_rqst * req- Request to pin
Description
Caller should be holding xprt->queue_lock.
-
void
xprt_update_rtt(struct rpc_task * task)¶ Update RPC RTT statistics
Parameters
struct rpc_task * task- RPC request that recently completed
Description
Caller holds xprt->queue_lock.
-
void
xprt_complete_rqst(struct rpc_task * task, int copied)¶ called when reply processing is complete
Parameters
struct rpc_task * task- RPC request that recently completed
int copied- actual number of bytes received from the transport
Description
Caller holds xprt->queue_lock.
-
void
xprt_wait_for_reply_request_def(struct rpc_task * task)¶ wait for reply
Parameters
struct rpc_task * task- pointer to rpc_task
Description
Set a request’s retransmit timeout based on the transport’s default timeout parameters. Used by transports that don’t adjust the retransmit timeout based on round-trip time estimation, and put the task to sleep on the pending queue.
-
void
xprt_wait_for_reply_request_rtt(struct rpc_task * task)¶ wait for reply using RTT estimator
Parameters
struct rpc_task * task- pointer to rpc_task
Description
Set a request’s retransmit timeout using the RTT estimator, and put the task to sleep on the pending queue.
-
struct rpc_xprt *
xprt_get(struct rpc_xprt * xprt)¶ return a reference to an RPC transport.
Parameters
struct rpc_xprt * xprt- pointer to the transport
-
void
xprt_put(struct rpc_xprt * xprt)¶ release a reference to an RPC transport.
Parameters
struct rpc_xprt * xprt- pointer to the transport
-
void
rpc_wake_up(struct rpc_wait_queue * queue)¶ wake up all rpc_tasks
Parameters
struct rpc_wait_queue * queue- rpc_wait_queue on which the tasks are sleeping
Description
Grabs queue->lock
-
void
rpc_wake_up_status(struct rpc_wait_queue * queue, int status)¶ wake up all rpc_tasks and set their status value.
Parameters
struct rpc_wait_queue * queue- rpc_wait_queue on which the tasks are sleeping
int status- status value to set
Description
Grabs queue->lock
-
int
rpc_malloc(struct rpc_task * task)¶ allocate RPC buffer resources
Parameters
struct rpc_task * task- RPC task
Description
A single memory region is allocated, which is split between the RPC call and RPC reply that this task is being used for. When this RPC is retired, the memory is released by calling rpc_free.
To prevent rpciod from hanging, this allocator never sleeps, returning -ENOMEM and suppressing warning if the request cannot be serviced immediately. The caller can arrange to sleep in a way that is safe for rpciod.
Most requests are ‘small’ (under 2KiB) and can be serviced from a mempool, ensuring that NFS reads and writes can always proceed, and that there is good locality of reference for these buffers.
-
void
rpc_free(struct rpc_task * task)¶ free RPC buffer resources allocated via rpc_malloc
Parameters
struct rpc_task * task- RPC task
Parameters
struct xdr_buf * xdr- target XDR buffer
struct sk_buff * skb- source skb
Description
We have set things up such that we perform the checksum of the UDP packet in parallel with the copies into the RPC client iovec. -DaveM
-
struct rpc_iostats *
rpc_alloc_iostats(struct rpc_clnt * clnt)¶ allocate an rpc_iostats structure
Parameters
struct rpc_clnt * clnt- RPC program, version, and xprt
-
void
rpc_free_iostats(struct rpc_iostats * stats)¶ release an rpc_iostats structure
Parameters
struct rpc_iostats * stats- doomed rpc_iostats structure
-
void
rpc_count_iostats_metrics(const struct rpc_task * task, struct rpc_iostats * op_metrics)¶ tally up per-task stats
Parameters
const struct rpc_task * task- completed rpc_task
struct rpc_iostats * op_metrics- stat structure for OP that will accumulate stats from task
-
void
rpc_count_iostats(const struct rpc_task * task, struct rpc_iostats * stats)¶ tally up per-task stats
Parameters
const struct rpc_task * task- completed rpc_task
struct rpc_iostats * stats- array of stat structures
Description
Uses the statidx from task
-
int
rpc_queue_upcall(struct rpc_pipe * pipe, struct rpc_pipe_msg * msg)¶ queue an upcall message to userspace
Parameters
struct rpc_pipe * pipe- upcall pipe on which to queue given message
struct rpc_pipe_msg * msg- message to queue
Description
Call with an inode created by rpc_mkpipe() to queue an upcall. A userspace process may then later read the upcall by performing a read on an open file for this inode. It is up to the caller to initialize the fields of msg (other than msg->list) appropriately.
-
struct dentry *
rpc_mkpipe_dentry(struct dentry * parent, const char * name, void * private, struct rpc_pipe * pipe)¶ make an rpc_pipefs file for kernel<->userspace communication
Parameters
struct dentry * parent- dentry of directory to create new “pipe” in
const char * name- name of pipe
void * private- private data to associate with the pipe, for the caller’s use
struct rpc_pipe * piperpc_pipecontaining input parameters
Description
Data is made available for userspace to read by calls to
rpc_queue_upcall(). The actual reads will result in calls to
ops->upcall, which will be called with the file pointer,
message, and userspace buffer to copy to.
Writes can come at any time, and do not necessarily have to be responses to upcalls. They will result in calls to msg->downcall.
The private argument passed here will be available to all these methods from the file pointer, via RPC_I(file_inode(file))->private.
-
int
rpc_unlink(struct dentry * dentry)¶ remove a pipe
Parameters
struct dentry * dentry- dentry for the pipe, as returned from rpc_mkpipe
Description
After this call, lookups will no longer find the pipe, and any attempts to read or write using preexisting opens of the pipe will return -EPIPE.
-
void
rpc_init_pipe_dir_head(struct rpc_pipe_dir_head * pdh)¶ initialise a struct rpc_pipe_dir_head
Parameters
struct rpc_pipe_dir_head * pdh- pointer to struct rpc_pipe_dir_head
-
void
rpc_init_pipe_dir_object(struct rpc_pipe_dir_object * pdo, const struct rpc_pipe_dir_object_ops * pdo_ops, void * pdo_data)¶ initialise a struct rpc_pipe_dir_object
Parameters
struct rpc_pipe_dir_object * pdo- pointer to struct rpc_pipe_dir_object
const struct rpc_pipe_dir_object_ops * pdo_ops- pointer to const struct rpc_pipe_dir_object_ops
void * pdo_data- pointer to caller-defined data
-
int
rpc_add_pipe_dir_object(struct net * net, struct rpc_pipe_dir_head * pdh, struct rpc_pipe_dir_object * pdo)¶ associate a rpc_pipe_dir_object to a directory
Parameters
struct net * net- pointer to struct net
struct rpc_pipe_dir_head * pdh- pointer to struct rpc_pipe_dir_head
struct rpc_pipe_dir_object * pdo- pointer to struct rpc_pipe_dir_object
-
void
rpc_remove_pipe_dir_object(struct net * net, struct rpc_pipe_dir_head * pdh, struct rpc_pipe_dir_object * pdo)¶ remove a rpc_pipe_dir_object from a directory
Parameters
struct net * net- pointer to struct net
struct rpc_pipe_dir_head * pdh- pointer to struct rpc_pipe_dir_head
struct rpc_pipe_dir_object * pdo- pointer to struct rpc_pipe_dir_object
-
struct rpc_pipe_dir_object *
rpc_find_or_alloc_pipe_dir_object(struct net * net, struct rpc_pipe_dir_head * pdh, int (*match) (struct rpc_pipe_dir_object *, void *, struct rpc_pipe_dir_object *(*alloc) (void *, void * data)¶
Parameters
struct net * net- pointer to struct net
struct rpc_pipe_dir_head * pdh- pointer to struct rpc_pipe_dir_head
int (*)(struct rpc_pipe_dir_object *, void *) match- match struct rpc_pipe_dir_object to data
struct rpc_pipe_dir_object *(*)(void *) alloc- allocate a new struct rpc_pipe_dir_object
void * data- user defined data for match() and alloc()
-
void
rpcb_getport_async(struct rpc_task * task)¶ obtain the port for a given RPC service on a given host
Parameters
struct rpc_task * task- task that is waiting for portmapper request
Description
This one can be called for an ongoing RPC request, and can be used in an async (rpciod) context.
-
struct rpc_clnt *
rpc_create(struct rpc_create_args * args)¶ create an RPC client and transport with one call
Parameters
struct rpc_create_args * args- rpc_clnt create argument structure
Description
Creates and initializes an RPC transport and an RPC client.
It can ping the server in order to determine if it is up, and to see if it supports this program and version. RPC_CLNT_CREATE_NOPING disables this behavior so asynchronous tasks can also use rpc_create.
-
struct rpc_clnt *
rpc_clone_client(struct rpc_clnt * clnt)¶ Clone an RPC client structure
Parameters
struct rpc_clnt * clnt- RPC client whose parameters are copied
Description
Returns a fresh RPC client or an ERR_PTR.
-
struct rpc_clnt *
rpc_clone_client_set_auth(struct rpc_clnt * clnt, rpc_authflavor_t flavor)¶ Clone an RPC client structure and set its auth
Parameters
struct rpc_clnt * clnt- RPC client whose parameters are copied
rpc_authflavor_t flavor- security flavor for new client
Description
Returns a fresh RPC client or an ERR_PTR.
-
int
rpc_switch_client_transport(struct rpc_clnt * clnt, struct xprt_create * args, const struct rpc_timeout * timeout)¶
Parameters
struct rpc_clnt * clnt- pointer to a struct rpc_clnt
struct xprt_create * args- pointer to the new transport arguments
const struct rpc_timeout * timeout- pointer to the new timeout parameters
Description
This function allows the caller to switch the RPC transport for the rpc_clnt structure ‘clnt’ to allow it to connect to a mirrored NFS server, for instance. It assumes that the caller has ensured that there are no active RPC tasks by using some form of locking.
Returns zero if “clnt” is now using the new xprt. Otherwise a negative errno is returned, and “clnt” continues to use the old xprt.
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int
rpc_clnt_iterate_for_each_xprt(struct rpc_clnt * clnt, int (*fn) (struct rpc_clnt *, struct rpc_xprt *, void *, void * data)¶ Apply a function to all transports
Parameters
struct rpc_clnt * clnt- pointer to client
int (*)(struct rpc_clnt *, struct rpc_xprt *, void *) fn- function to apply
void * data- void pointer to function data
Description
Iterates through the list of RPC transports currently attached to the client and applies the function fn(clnt, xprt, data).
On error, the iteration stops, and the function returns the error value.
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struct rpc_clnt *
rpc_bind_new_program(struct rpc_clnt * old, const struct rpc_program * program, u32 vers)¶ bind a new RPC program to an existing client
Parameters
struct rpc_clnt * old- old rpc_client
const struct rpc_program * program- rpc program to set
u32 vers- rpc program version
Description
Clones the rpc client and sets up a new RPC program. This is mainly of use for enabling different RPC programs to share the same transport. The Sun NFSv2/v3 ACL protocol can do this.
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struct rpc_task *
rpc_run_task(const struct rpc_task_setup * task_setup_data)¶ Allocate a new RPC task, then run rpc_execute against it
Parameters
const struct rpc_task_setup * task_setup_data- pointer to task initialisation data
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int
rpc_call_sync(struct rpc_clnt * clnt, const struct rpc_message * msg, int flags)¶ Perform a synchronous RPC call
Parameters
struct rpc_clnt * clnt- pointer to RPC client
const struct rpc_message * msg- RPC call parameters
int flags- RPC call flags
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int
rpc_call_async(struct rpc_clnt * clnt, const struct rpc_message * msg, int flags, const struct rpc_call_ops * tk_ops, void * data)¶ Perform an asynchronous RPC call
Parameters
struct rpc_clnt * clnt- pointer to RPC client
const struct rpc_message * msg- RPC call parameters
int flags- RPC call flags
const struct rpc_call_ops * tk_ops- RPC call ops
void * data- user call data
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void
rpc_prepare_reply_pages(struct rpc_rqst * req, struct page ** pages, unsigned int base, unsigned int len, unsigned int hdrsize)¶ Prepare to receive a reply data payload into pages
Parameters
struct rpc_rqst * req- RPC request to prepare
struct page ** pages- vector of struct page pointers
unsigned int base- offset in first page where receive should start, in bytes
unsigned int len- expected size of the upper layer data payload, in bytes
unsigned int hdrsize- expected size of upper layer reply header, in XDR words
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size_t
rpc_peeraddr(struct rpc_clnt * clnt, struct sockaddr * buf, size_t bufsize)¶ extract remote peer address from clnt’s xprt
Parameters
struct rpc_clnt * clnt- RPC client structure
struct sockaddr * buf- target buffer
size_t bufsize- length of target buffer
Description
Returns the number of bytes that are actually in the stored address.
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const char *
rpc_peeraddr2str(struct rpc_clnt * clnt, enum rpc_display_format_t format)¶ return remote peer address in printable format
Parameters
struct rpc_clnt * clnt- RPC client structure
enum rpc_display_format_t format- address format
Description
NB: the lifetime of the memory referenced by the returned pointer is the same as the rpc_xprt itself. As long as the caller uses this pointer, it must hold the RCU read lock.
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int
rpc_localaddr(struct rpc_clnt * clnt, struct sockaddr * buf, size_t buflen)¶ discover local endpoint address for an RPC client
Parameters
struct rpc_clnt * clnt- RPC client structure
struct sockaddr * buf- target buffer
size_t buflen- size of target buffer, in bytes
Description
Returns zero and fills in “buf” and “buflen” if successful; otherwise, a negative errno is returned.
This works even if the underlying transport is not currently connected, or if the upper layer never previously provided a source address.
The result of this function call is transient: multiple calls in succession may give different results, depending on how local networking configuration changes over time.
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struct net *
rpc_net_ns(struct rpc_clnt * clnt)¶ Get the network namespace for this RPC client
Parameters
struct rpc_clnt * clnt- RPC client to query
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size_t
rpc_max_payload(struct rpc_clnt * clnt)¶ Get maximum payload size for a transport, in bytes
Parameters
struct rpc_clnt * clnt- RPC client to query
Description
For stream transports, this is one RPC record fragment (see RFC 1831), as we don’t support multi-record requests yet. For datagram transports, this is the size of an IP packet minus the IP, UDP, and RPC header sizes.
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size_t
rpc_max_bc_payload(struct rpc_clnt * clnt)¶ Get maximum backchannel payload size, in bytes
Parameters
struct rpc_clnt * clnt- RPC client to query
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void
rpc_force_rebind(struct rpc_clnt * clnt)¶ force transport to check that remote port is unchanged
Parameters
struct rpc_clnt * clnt- client to rebind
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int
rpc_clnt_test_and_add_xprt(struct rpc_clnt * clnt, struct rpc_xprt_switch * xps, struct rpc_xprt * xprt, void * dummy)¶ Test and add a new transport to a rpc_clnt
Parameters
struct rpc_clnt * clnt- pointer to struct rpc_clnt
struct rpc_xprt_switch * xps- pointer to struct rpc_xprt_switch,
struct rpc_xprt * xprt- pointer struct rpc_xprt
void * dummy- unused
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int
rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt * clnt, struct rpc_xprt_switch * xps, struct rpc_xprt * xprt, void * data)¶
Parameters
struct rpc_clnt * clnt- struct rpc_clnt to get the new transport
struct rpc_xprt_switch * xps- the rpc_xprt_switch to hold the new transport
struct rpc_xprt * xprt- the rpc_xprt to test
void * data- a struct rpc_add_xprt_test pointer that holds the test function and test function call data
Description
- This is an rpc_clnt_add_xprt setup() function which returns 1 so:
- 1) caller of the test function must dereference the rpc_xprt_switch and the rpc_xprt. 2) test function must call rpc_xprt_switch_add_xprt, usually in the rpc_call_done routine.
Upon success (return of 1), the test function adds the new transport to the rpc_clnt xprt switch
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int
rpc_clnt_add_xprt(struct rpc_clnt * clnt, struct xprt_create * xprtargs, int (*setup) (struct rpc_clnt *, struct rpc_xprt_switch *, struct rpc_xprt *, void *, void * data)¶ Add a new transport to a rpc_clnt
Parameters
struct rpc_clnt * clnt- pointer to struct rpc_clnt
struct xprt_create * xprtargs- pointer to struct xprt_create
int (*)(struct rpc_clnt *, struct rpc_xprt_switch *, struct rpc_xprt *, void *) setup- callback to test and/or set up the connection
void * data- pointer to setup function data
Description
Creates a new transport using the parameters set in args and adds it to clnt. If ping is set, then test that connectivity succeeds before adding the new transport.
WiMAX¶
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struct sk_buff *
wimax_msg_alloc(struct wimax_dev * wimax_dev, const char * pipe_name, const void * msg, size_t size, gfp_t gfp_flags)¶ Create a new skb for sending a message to userspace
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
const char * pipe_name- “named pipe” the message will be sent to
const void * msg- pointer to the message data to send
size_t size- size of the message to send (in bytes), including the header.
gfp_t gfp_flags- flags for memory allocation.
Return
0 if ok, negative errno code on error
Description
Allocates an skb that will contain the message to send to user space over the messaging pipe and initializes it, copying the payload.
Once this call is done, you can deliver it with
wimax_msg_send().
IMPORTANT:
Don’t use skb_push()/skb_pull()/skb_reserve() on the skb, as
wimax_msg_send() depends on skb->data being placed at the
beginning of the user message.
Unlike other WiMAX stack calls, this call can be used way early,
even before wimax_dev_add() is called, as long as the
wimax_dev->net_dev pointer is set to point to a proper
net_dev. This is so that drivers can use it early in case they need
to send stuff around or communicate with user space.
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const void *
wimax_msg_data_len(struct sk_buff * msg, size_t * size)¶ Return a pointer and size of a message’s payload
Parameters
struct sk_buff * msg- Pointer to a message created with
wimax_msg_alloc() size_t * size- Pointer to where to store the message’s size
Description
Returns the pointer to the message data.
Parameters
struct sk_buff * msg- Pointer to a message created with
wimax_msg_alloc()
Parameters
struct sk_buff * msg- Pointer to a message created with
wimax_msg_alloc()
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int
wimax_msg_send(struct wimax_dev * wimax_dev, struct sk_buff * skb)¶ Send a pre-allocated message to user space
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
struct sk_buff * skbstruct sk_buffreturned bywimax_msg_alloc(). Note the ownership of skb is transferred to this function.
Return
0 if ok, < 0 errno code on error
Description
Sends a free-form message that was preallocated with
wimax_msg_alloc() and filled up.
Assumes that once you pass an skb to this function for sending, it owns it and will release it when done (on success).
IMPORTANT:
Don’t use skb_push()/skb_pull()/skb_reserve() on the skb, as
wimax_msg_send() depends on skb->data being placed at the
beginning of the user message.
Unlike other WiMAX stack calls, this call can be used way early,
even before wimax_dev_add() is called, as long as the
wimax_dev->net_dev pointer is set to point to a proper
net_dev. This is so that drivers can use it early in case they need
to send stuff around or communicate with user space.
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int
wimax_msg(struct wimax_dev * wimax_dev, const char * pipe_name, const void * buf, size_t size, gfp_t gfp_flags)¶ Send a message to user space
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor (properly referenced)
const char * pipe_name- “named pipe” the message will be sent to
const void * buf- pointer to the message to send.
size_t size- size of the buffer pointed to by buf (in bytes).
gfp_t gfp_flags- flags for memory allocation.
Return
0 if ok, negative errno code on error.
Description
Sends a free-form message to user space on the device wimax_dev.
NOTES
Once the skb is given to this function, who will own it and will release it when done (unless it returns error).
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
Return
0 if ok and a warm reset was done (the device still exists in
the system).
-ENODEV if a cold/bus reset had to be done (device has
disconnected and reconnected, so current handle is not valid
any more).
-EINVAL if the device is not even registered.
Any other negative error code shall be considered as non-recoverable.
Description
Called when wanting to reset the device for any reason. Device is taken back to power on status.
This call blocks; on successful return, the device has completed the reset process and is ready to operate.
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void
wimax_report_rfkill_hw(struct wimax_dev * wimax_dev, enum wimax_rf_state state)¶ Reports changes in the hardware RF switch
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
enum wimax_rf_state state- New state of the RF Kill switch.
WIMAX_RF_ONradio on,WIMAX_RF_OFFradio off.
Description
When the device detects a change in the state of thehardware RF switch, it must call this function to let the WiMAX kernel stack know that the state has changed so it can be properly propagated.
The WiMAX stack caches the state (the driver doesn’t need to). As well, as the change is propagated it will come back as a request to change the software state to mirror the hardware state.
If the device doesn’t have a hardware kill switch, just report
it on initialization as always on (WIMAX_RF_ON, radio on).
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void
wimax_report_rfkill_sw(struct wimax_dev * wimax_dev, enum wimax_rf_state state)¶ Reports changes in the software RF switch
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
enum wimax_rf_state state- New state of the RF kill switch.
WIMAX_RF_ONradio on,WIMAX_RF_OFFradio off.
Description
Reports changes in the software RF switch state to the WiMAX stack.
The main use is during initialization, so the driver can query the device for its current software radio kill switch state and feed it to the system.
On the side, the device does not change the software state by itself. In practice, this can happen, as the device might decide to switch (in software) the radio off for different reasons.
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int
wimax_rfkill(struct wimax_dev * wimax_dev, enum wimax_rf_state state)¶ Set the software RF switch state for a WiMAX device
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
enum wimax_rf_state state- New RF state.
Return
>= 0 toggle state if ok, < 0 errno code on error. The toggle state is returned as a bitmap, bit 0 being the hardware RF state, bit 1 the software RF state.
0 means disabled (WIMAX_RF_ON, radio on), 1 means enabled radio
off (WIMAX_RF_OFF).
Description
Called by the user when he wants to request the WiMAX radio to be
switched on (WIMAX_RF_ON) or off (WIMAX_RF_OFF). With
WIMAX_RF_QUERY, just the current state is returned.
NOTE
This call will block until the operation is complete.
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void
wimax_state_change(struct wimax_dev * wimax_dev, enum wimax_st new_state)¶ Set the current state of a WiMAX device
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor (properly referenced)
enum wimax_st new_state- New state to switch to
Description
This implements the state changes for the wimax devices. It will
- verify that the state transition is legal (for now it’ll just print a warning if not) according to the table in linux/wimax.h’s documentation for ‘enum wimax_st’.
- perform the actions needed for leaving the current state and whichever are needed for entering the new state.
- issue a report to user space indicating the new state (and an optional payload with information about the new state).
NOTE
wimax_dev must be locked
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enum wimax_st
wimax_state_get(struct wimax_dev * wimax_dev)¶ Return the current state of a WiMAX device
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
Return
Current state of the device according to its driver.
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor to initialize.
Description
Initializes fields of a freshly allocated wimax_dev instance. This function assumes that after allocation, the memory occupied by wimax_dev was zeroed.
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int
wimax_dev_add(struct wimax_dev * wimax_dev, struct net_device * net_dev)¶ Register a new WiMAX device
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor (as embedded in your net_dev’s
priv data). You must have called
wimax_dev_init()on it before. struct net_device * net_dev- net device the wimax_dev is associated with. The
function expects SET_NETDEV_DEV() and
register_netdev()were already called on it.
Description
Registers the new WiMAX device, sets up the user-kernel control interface (generic netlink) and common WiMAX infrastructure.
Note that the parts that will allow interaction with user space are setup at the very end, when the rest is in place, as once that happens, the driver might get user space control requests via netlink or from debugfs that might translate into calls into wimax_dev->op_*().
Parameters
struct wimax_dev * wimax_dev- WiMAX device descriptor
Description
Unregisters a WiMAX device previously registered for use with wimax_add_rm().
IMPORTANT! Must call before calling unregister_netdev().
After this function returns, you will not get any more user space control requests (via netlink or debugfs) and thus to wimax_dev->ops.
Reentrancy control is ensured by setting the state to
__WIMAX_ST_QUIESCING. rfkill operations coming through
wimax_*rfkill*() will be stopped by the quiescing state; ops coming
from the rfkill subsystem will be stopped by the support being
removed by wimax_rfkill_rm().
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struct
wimax_dev¶ Generic WiMAX device
Definition
struct wimax_dev {
struct net_device *net_dev;
struct list_head id_table_node;
struct mutex mutex;
struct mutex mutex_reset;
enum wimax_st state;
int (*op_msg_from_user)(struct wimax_dev *wimax_dev,const char *,const void *, size_t, const struct genl_info *info);
int (*op_rfkill_sw_toggle)(struct wimax_dev *wimax_dev, enum wimax_rf_state);
int (*op_reset)(struct wimax_dev *wimax_dev);
struct rfkill *rfkill;
unsigned int rf_hw;
unsigned int rf_sw;
char name[32];
struct dentry *debugfs_dentry;
};
Members
net_dev- [fill] Pointer to the
struct net_devicethis WiMAX device implements. id_table_node- [private] link to the list of wimax devices kept by id-table.c. Protected by it’s own spinlock.
mutex- [private] Serializes all concurrent access and execution of operations.
mutex_reset- [private] Serializes reset operations. Needs to be a different mutex because as part of the reset operation, the driver has to call back into the stack to do things such as state change, that require wimax_dev->mutex.
state- [private] Current state of the WiMAX device.
op_msg_from_user- [fill] Driver-specific operation to handle a raw message from user space to the driver. The driver can send messages to user space using with wimax_msg_to_user().
op_rfkill_sw_toggle- [fill] Driver-specific operation to act on userspace (or any other agent) requesting the WiMAX device to change the RF Kill software switch (WIMAX_RF_ON or WIMAX_RF_OFF). If such hardware support is not present, it is assumed the radio cannot be switched off and it is always on (and the stack will error out when trying to switch it off). In such case, this function pointer can be left as NULL.
op_reset- [fill] Driver specific operation to reset the device. This operation should always attempt first a warm reset that does not disconnect the device from the bus and return 0. If that fails, it should resort to some sort of cold or bus reset (even if it implies a bus disconnection and device disappearance). In that case, -ENODEV should be returned to indicate the device is gone. This operation has to be synchronous, and return only when the reset is complete. In case of having had to resort to bus/cold reset implying a device disconnection, the call is allowed to return immediately.
rfkill- [private] integration into the RF-Kill infrastructure.
rf_hw- [private] State of the hardware radio switch (OFF/ON)
rf_sw- [private] State of the software radio switch (OFF/ON)
name- [fill] A way to identify this device. We need to register a
name with many subsystems (rfkill, workqueue creation, etc).
We can’t use the network device name as that
might change and in some instances we don’t know it yet (until
we don’t call
register_netdev()). So we generate an unique one using the driver name and device bus id, place it here and use it across the board. Recommended naming: DRIVERNAME-BUSNAME:BUSID (dev->bus->name, dev->bus_id). debugfs_dentry- [private] Used to hook up a debugfs entry. This shows up in the debugfs root as wimax:DEVICENAME.
NOTE
- wimax_dev->mutex is NOT locked when this op is being
- called; however, wimax_dev->mutex_reset IS locked to ensure
serialization of calls to
wimax_reset(). Seewimax_reset()’s documentation.
Description
This structure defines a common interface to access all WiMAX devices from different vendors and provides a common API as well as a free-form device-specific messaging channel.
- Usage:
- Embed a
struct wimax_devat the beginning the network device structure so thatnetdev_priv()points to it. memset()it to zero- Initialize with
wimax_dev_init(). This will leave the WiMAX device in the__WIMAX_ST_NULLstate. - Fill all the fields marked with [fill]; once called
wimax_dev_add(), those fields CANNOT be modified. - Call
wimax_dev_add()after registering the network device. This will leave the WiMAX device in theWIMAX_ST_DOWNstate. Protect the driver’s net_device->open() against succeeding if the wimax device state is lower thanWIMAX_ST_DOWN. - Select when the device is going to be turned on/initialized; for example, it could be initialized on ‘ifconfig up’ (when the netdev op ‘open()’ is called on the driver).
- Embed a
When the device is initialized (at ifconfig up time, or right
after calling wimax_dev_add() from _probe(), make sure the
following steps are taken
- Move the device to
WIMAX_ST_UNINITIALIZED. This is needed so some API calls that shouldn’t work until the device is ready can be blocked.- Initialize the device. Make sure to turn the SW radio switch off and move the device to state
WIMAX_ST_RADIO_OFFwhen done. When just initialized, a device should be left in RADIO OFF state until user space devices to turn it on.- Query the device for the state of the hardware rfkill switch and call wimax_rfkill_report_hw() and wimax_rfkill_report_sw() as needed. See below.
wimax_dev_rm() undoes before unregistering the network device. Once
wimax_dev_add() is called, the driver can get called on the
wimax_dev->op_* function pointers
CONCURRENCY:
The stack provides a mutex for each device that will disallow API calls happening concurrently; thus, op calls into the driver through the wimax_dev->op*() function pointers will always be serialized and never concurrent.
For locking, take wimax_dev->mutex is taken; (most) operations in the API have to check for wimax_dev_is_ready() to return 0 before continuing (this is done internally).
REFERENCE COUNTING:
The WiMAX device is reference counted by the associated network device. The only operation that can be used to reference the device is wimax_dev_get_by_genl_info(), and the reference it acquires has to be released with dev_put(wimax_dev->net_dev).
RFKILL:
At startup, both HW and SW radio switchess are assumed to be off.
At initialization time [after calling wimax_dev_add()], have the
driver query the device for the status of the software and hardware
RF kill switches and call wimax_report_rfkill_hw() and
wimax_rfkill_report_sw() to indicate their state. If any is
missing, just call it to indicate it is ON (radio always on).
Whenever the driver detects a change in the state of the RF kill
switches, it should call wimax_report_rfkill_hw() or
wimax_report_rfkill_sw() to report it to the stack.
-
enum
wimax_st¶ The different states of a WiMAX device
Constants
__WIMAX_ST_NULL- The device structure has been allocated and zeroed,
but still
wimax_dev_add()hasn’t been called. There is no state. WIMAX_ST_DOWN- The device has been registered with the WiMAX and
networking stacks, but it is not initialized (normally that is
done with ‘ifconfig DEV up’ [or equivalent], which can upload
firmware and enable communications with the device).
In this state, the device is powered down and using as less
power as possible.
This state is the default after a call to
wimax_dev_add(). It is ok to have drivers move directly toWIMAX_ST_UNINITIALIZEDorWIMAX_ST_RADIO_OFFin _probe() after the call towimax_dev_add(). It is recommended that the driver leaves this state when calling ‘ifconfig DEV up’ and enters it back on ‘ifconfig DEV down’. __WIMAX_ST_QUIESCING- The device is being torn down, so no API operations are allowed to proceed except the ones needed to complete the device clean up process.
WIMAX_ST_UNINITIALIZED- [optional] Communication with the device is setup, but the device still requires some configuration before being operational. Some WiMAX API calls might work.
WIMAX_ST_RADIO_OFF- The device is fully up; radio is off (wether by hardware or software switches). It is recommended to always leave the device in this state after initialization.
WIMAX_ST_READY- The device is fully up and radio is on.
WIMAX_ST_SCANNING- [optional] The device has been instructed to scan. In this state, the device cannot be actively connected to a network.
WIMAX_ST_CONNECTING- The device is connecting to a network. This state exists because in some devices, the connect process can include a number of negotiations between user space, kernel space and the device. User space needs to know what the device is doing. If the connect sequence in a device is atomic and fast, the device can transition directly to CONNECTED
WIMAX_ST_CONNECTED- The device is connected to a network.
__WIMAX_ST_INVALID- This is an invalid state used to mark the maximum numeric value of states.
Description
Transitions from one state to another one are atomic and can only
be caused in kernel space with wimax_state_change(). To read the
state, use wimax_state_get().
States starting with __ are internal and shall not be used or referred to by drivers or userspace. They look ugly, but that’s the point – if any use is made non-internal to the stack, it is easier to catch on review.
All API operations [with well defined exceptions] will take the
device mutex before starting and then check the state. If the state
is __WIMAX_ST_NULL, WIMAX_ST_DOWN, WIMAX_ST_UNINITIALIZED or
__WIMAX_ST_QUIESCING, it will drop the lock and quit with
-EINVAL, -ENOMEDIUM, -ENOTCONN or -ESHUTDOWN.
The order of the definitions is important, so we can do numerical
comparisons (eg: < WIMAX_ST_RADIO_OFF means the device is not ready
to operate).
Network device support¶
Driver Support¶
-
void
dev_add_pack(struct packet_type * pt)¶ add packet handler
Parameters
struct packet_type * pt- packet type declaration
Description
Add a protocol handler to the networking stack. The passed
packet_typeis linked into kernel lists and may not be freed until it has been removed from the kernel lists.This call does not sleep therefore it can not guarantee all CPU’s that are in middle of receiving packets will see the new packet type (until the next received packet).
-
void
__dev_remove_pack(struct packet_type * pt)¶ remove packet handler
Parameters
struct packet_type * pt- packet type declaration
Description
Remove a protocol handler that was previously added to the kernel protocol handlers by
dev_add_pack(). The passedpacket_typeis removed from the kernel lists and can be freed or reused once this function returns.The packet type might still be in use by receivers and must not be freed until after all the CPU’s have gone through a quiescent state.
-
void
dev_remove_pack(struct packet_type * pt)¶ remove packet handler
Parameters
struct packet_type * pt- packet type declaration
Description
Remove a protocol handler that was previously added to the kernel protocol handlers by
dev_add_pack(). The passedpacket_typeis removed from the kernel lists and can be freed or reused once this function returns.This call sleeps to guarantee that no CPU is looking at the packet type after return.
-
void
dev_add_offload(struct packet_offload * po)¶ register offload handlers
Parameters
struct packet_offload * po- protocol offload declaration
Description
Add protocol offload handlers to the networking stack. The passed
proto_offloadis linked into kernel lists and may not be freed until it has been removed from the kernel lists.This call does not sleep therefore it can not guarantee all CPU’s that are in middle of receiving packets will see the new offload handlers (until the next received packet).
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void
dev_remove_offload(struct packet_offload * po)¶ remove packet offload handler
Parameters
struct packet_offload * po- packet offload declaration
Description
Remove a packet offload handler that was previously added to the kernel offload handlers by
dev_add_offload(). The passedoffload_typeis removed from the kernel lists and can be freed or reused once this function returns.This call sleeps to guarantee that no CPU is looking at the packet type after return.
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int
netdev_boot_setup_check(struct net_device * dev)¶ check boot time settings
Parameters
struct net_device * dev- the netdevice
Description
Check boot time settings for the device. The found settings are set for the device to be used later in the device probing. Returns 0 if no settings found, 1 if they are.
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int
dev_get_iflink(const struct net_device * dev)¶ get ‘iflink’ value of a interface
Parameters
const struct net_device * dev- targeted interface
Description
Indicates the ifindex the interface is linked to. Physical interfaces have the same ‘ifindex’ and ‘iflink’ values.
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int
dev_fill_metadata_dst(struct net_device * dev, struct sk_buff * skb)¶ Retrieve tunnel egress information.
Parameters
struct net_device * dev- targeted interface
struct sk_buff * skb- The packet.
Description
For better visibility of tunnel traffic OVS needs to retrieve egress tunnel information for a packet. Following API allows user to get this info.
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struct net_device *
__dev_get_by_name(struct net * net, const char * name)¶ find a device by its name
Parameters
struct net * net- the applicable net namespace
const char * name- name to find
Description
Find an interface by name. Must be called under RTNL semaphore or dev_base_lock. If the name is found a pointer to the device is returned. If the name is not found thenNULLis returned. The reference counters are not incremented so the caller must be careful with locks.
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struct net_device *
dev_get_by_name_rcu(struct net * net, const char * name)¶ find a device by its name
Parameters
struct net * net- the applicable net namespace
const char * name- name to find
Description
Find an interface by name.
If the name is found a pointer to the device is returned.
If the name is not found then NULL is returned.
The reference counters are not incremented so the caller must be
careful with locks. The caller must hold RCU lock.
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struct net_device *
dev_get_by_name(struct net * net, const char * name)¶ find a device by its name
Parameters
struct net * net- the applicable net namespace
const char * name- name to find
Description
Find an interface by name. This can be called from any context and does its own locking. The returned handle has the usage count incremented and the caller must usedev_put()to release it when it is no longer needed.NULLis returned if no matching device is found.
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struct net_device *
__dev_get_by_index(struct net * net, int ifindex)¶ find a device by its ifindex
Parameters
struct net * net- the applicable net namespace
int ifindex- index of device
Description
Search for an interface by index. ReturnsNULLif the device is not found or a pointer to the device. The device has not had its reference counter increased so the caller must be careful about locking. The caller must hold either the RTNL semaphore or dev_base_lock.
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struct net_device *
dev_get_by_index_rcu(struct net * net, int ifindex)¶ find a device by its ifindex
Parameters
struct net * net- the applicable net namespace
int ifindex- index of device
Description
Search for an interface by index. ReturnsNULLif the device is not found or a pointer to the device. The device has not had its reference counter increased so the caller must be careful about locking. The caller must hold RCU lock.
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struct net_device *
dev_get_by_index(struct net * net, int ifindex)¶ find a device by its ifindex
Parameters
struct net * net- the applicable net namespace
int ifindex- index of device
Description
Search for an interface by index. Returns NULL if the device is not found or a pointer to the device. The device returned has had a reference added and the pointer is safe until the user calls dev_put to indicate they have finished with it.
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struct net_device *
dev_get_by_napi_id(unsigned int napi_id)¶ find a device by napi_id
Parameters
unsigned int napi_id- ID of the NAPI struct
Description
Search for an interface by NAPI ID. ReturnsNULLif the device is not found or a pointer to the device. The device has not had its reference counter increased so the caller must be careful about locking. The caller must hold RCU lock.
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struct net_device *
dev_getbyhwaddr_rcu(struct net * net, unsigned short type, const char * ha)¶ find a device by its hardware address
Parameters
struct net * net- the applicable net namespace
unsigned short type- media type of device
const char * ha- hardware address
Description
Search for an interface by MAC address. Returns NULL if the device is not found or a pointer to the device. The caller must hold RCU or RTNL. The returned device has not had its ref count increased and the caller must therefore be careful about locking
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struct net_device *
__dev_get_by_flags(struct net * net, unsigned short if_flags, unsigned short mask)¶ find any device with given flags
Parameters
struct net * net- the applicable net namespace
unsigned short if_flags- IFF_* values
unsigned short mask- bitmask of bits in if_flags to check
Description
Search for any interface with the given flags. Returns NULL if a device is not found or a pointer to the device. Must be called inside rtnl_lock(), and result refcount is unchanged.
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bool
dev_valid_name(const char * name)¶ check if name is okay for network device
Parameters
const char * name- name string
Description
Network device names need to be valid file names to to allow sysfs to work. We also disallow any kind of whitespace.
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int
dev_alloc_name(struct net_device * dev, const char * name)¶ allocate a name for a device
Parameters
struct net_device * dev- device
const char * name- name format string
Description
Passed a format string - eg “lt``d``” it will try and find a suitable id. It scans list of devices to build up a free map, then chooses the first empty slot. The caller must hold the dev_base or rtnl lock while allocating the name and adding the device in order to avoid duplicates. Limited to bits_per_byte * page size devices (ie 32K on most platforms). Returns the number of the unit assigned or a negative errno code.
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int
dev_set_alias(struct net_device * dev, const char * alias, size_t len)¶ change ifalias of a device
Parameters
struct net_device * dev- device
const char * alias- name up to IFALIASZ
size_t len- limit of bytes to copy from info
Description
Set ifalias for a device,
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void
netdev_features_change(struct net_device * dev)¶ device changes features
Parameters
struct net_device * dev- device to cause notification
Description
Called to indicate a device has changed features.
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void
netdev_state_change(struct net_device * dev)¶ device changes state
Parameters
struct net_device * dev- device to cause notification
Description
Called to indicate a device has changed state. This function calls the notifier chains for netdev_chain and sends a NEWLINK message to the routing socket.
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void
netdev_notify_peers(struct net_device * dev)¶ notify network peers about existence of dev
Parameters
struct net_device * dev- network device
Description
Generate traffic such that interested network peers are aware of dev, such as by generating a gratuitous ARP. This may be used when a device wants to inform the rest of the network about some sort of reconfiguration such as a failover event or virtual machine migration.
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int
dev_open(struct net_device * dev, struct netlink_ext_ack * extack)¶ prepare an interface for use.
Parameters
struct net_device * dev- device to open
struct netlink_ext_ack * extack- netlink extended ack
Description
Takes a device from down to up state. The device’s private open function is invoked and then the multicast lists are loaded. Finally the device is moved into the up state and a
NETDEV_UPmessage is sent to the netdev notifier chain.Calling this function on an active interface is a nop. On a failure a negative errno code is returned.
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void
dev_close(struct net_device * dev)¶ shutdown an interface.
Parameters
struct net_device * dev- device to shutdown
Description
This function moves an active device into down state. ANETDEV_GOING_DOWNis sent to the netdev notifier chain. The device is then deactivated and finally aNETDEV_DOWNis sent to the notifier chain.
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void
dev_disable_lro(struct net_device * dev)¶ disable Large Receive Offload on a device
Parameters
struct net_device * dev- device
Description
Disable Large Receive Offload (LRO) on a net device. Must be called under RTNL. This is needed if received packets may be forwarded to another interface.
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int
register_netdevice_notifier(struct notifier_block * nb)¶ register a network notifier block
Parameters
struct notifier_block * nb- notifier
Description
Register a notifier to be called when network device events occur. The notifier passed is linked into the kernel structures and must not be reused until it has been unregistered. A negative errno code is returned on a failure.
When registered all registration and up events are replayed to the new notifier to allow device to have a race free view of the network device list.
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int
unregister_netdevice_notifier(struct notifier_block * nb)¶ unregister a network notifier block
Parameters
struct notifier_block * nb- notifier
Description
Unregister a notifier previously registered by
register_netdevice_notifier(). The notifier is unlinked into the
kernel structures and may then be reused. A negative errno code
is returned on a failure.
After unregistering unregister and down device events are synthesized for all devices on the device list to the removed notifier to remove the need for special case cleanup code.
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int
call_netdevice_notifiers(unsigned long val, struct net_device * dev)¶ call all network notifier blocks
Parameters
unsigned long val- value passed unmodified to notifier function
struct net_device * dev- net_device pointer passed unmodified to notifier function
Description
Call all network notifier blocks. Parameters and return value are as for raw_notifier_call_chain().
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int
dev_forward_skb(struct net_device * dev, struct sk_buff * skb)¶ loopback an skb to another netif
Parameters
struct net_device * dev- destination network device
struct sk_buff * skb- buffer to forward
Description
- return values:
- NET_RX_SUCCESS (no congestion) NET_RX_DROP (packet was dropped, but freed)
dev_forward_skb can be used for injecting an skb from the start_xmit function of one device into the receive queue of another device.
The receiving device may be in another namespace, so we have to clear all information in the skb that could impact namespace isolation.
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bool
dev_nit_active(struct net_device * dev)¶ return true if any network interface taps are in use
Parameters
struct net_device * dev- network device to check for the presence of taps
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int
netif_set_real_num_rx_queues(struct net_device * dev, unsigned int rxq)¶ set actual number of RX queues used
Parameters
struct net_device * dev- Network device
unsigned int rxq- Actual number of RX queues
Description
This must be called either with the rtnl_lock held or before registration of the net device. Returns 0 on success, or a negative error code. If called before registration, it always succeeds.
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int
netif_get_num_default_rss_queues(void)¶ default number of RSS queues
Parameters
void- no arguments
Description
This routine should set an upper limit on the number of RSS queues used by default by multiqueue devices.
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void
netif_device_detach(struct net_device * dev)¶ mark device as removed
Parameters
struct net_device * dev- network device
Description
Mark device as removed from system and therefore no longer available.
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void
netif_device_attach(struct net_device * dev)¶ mark device as attached
Parameters
struct net_device * dev- network device
Description
Mark device as attached from system and restart if needed.
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struct sk_buff *
skb_mac_gso_segment(struct sk_buff * skb, netdev_features_t features)¶ mac layer segmentation handler.
Parameters
struct sk_buff * skb- buffer to segment
netdev_features_t features- features for the output path (see dev->features)
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struct sk_buff *
__skb_gso_segment(struct sk_buff * skb, netdev_features_t features, bool tx_path)¶ Perform segmentation on skb.
Parameters
struct sk_buff * skb- buffer to segment
netdev_features_t features- features for the output path (see dev->features)
bool tx_path- whether it is called in TX path
Description
This function segments the given skb and returns a list of segments.
It may return NULL if the skb requires no segmentation. This is only possible when GSO is used for verifying header integrity.
Segmentation preserves SKB_SGO_CB_OFFSET bytes of previous skb cb.
Parameters
struct net * net- network namespace this loopback is happening in
struct sock * sk- sk needed to be a netfilter okfn
struct sk_buff * skb- buffer to transmit
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bool
rps_may_expire_flow(struct net_device * dev, u16 rxq_index, u32 flow_id, u16 filter_id)¶ check whether an RFS hardware filter may be removed
Parameters
struct net_device * dev- Device on which the filter was set
u16 rxq_index- RX queue index
u32 flow_id- Flow ID passed to ndo_rx_flow_steer()
u16 filter_id- Filter ID returned by ndo_rx_flow_steer()
Description
Drivers that implement ndo_rx_flow_steer() should periodically call
this function for each installed filter and remove the filters for
which it returns true.
Parameters
struct sk_buff * skb- buffer to post
Description
This function receives a packet from a device driver and queues it for the upper (protocol) levels to process. It always succeeds. The buffer may be dropped during processing for congestion control or by the protocol layers.
return values: NET_RX_SUCCESS (no congestion) NET_RX_DROP (packet was dropped)
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bool
netdev_is_rx_handler_busy(struct net_device * dev)¶ check if receive handler is registered
Parameters
struct net_device * dev- device to check
Description
Check if a receive handler is already registered for a given device. Return true if there one.
The caller must hold the rtnl_mutex.
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int
netdev_rx_handler_register(struct net_device * dev, rx_handler_func_t * rx_handler, void * rx_handler_data)¶ register receive handler
Parameters
struct net_device * dev- device to register a handler for
rx_handler_func_t * rx_handler- receive handler to register
void * rx_handler_data- data pointer that is used by rx handler
Description
Register a receive handler for a device. This handler will then be called from __netif_receive_skb. A negative errno code is returned on a failure.
The caller must hold the rtnl_mutex.
For a general description of rx_handler, see enum rx_handler_result.
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void
netdev_rx_handler_unregister(struct net_device * dev)¶ unregister receive handler
Parameters
struct net_device * dev- device to unregister a handler from
Description
Unregister a receive handler from a device.
The caller must hold the rtnl_mutex.
Parameters
struct sk_buff * skb- buffer to process
Description
More direct receive version of
netif_receive_skb(). It should only be used by callers that have a need to skip RPS and Generic XDP. Caller must also take care of handling if (page_is_)pfmemalloc.This function may only be called from softirq context and interrupts should be enabled.
Return values (usually ignored): NET_RX_SUCCESS: no congestion NET_RX_DROP: packet was dropped
Parameters
struct sk_buff * skb- buffer to process
Description
netif_receive_skb()is the main receive data processing function. It always succeeds. The buffer may be dropped during processing for congestion control or by the protocol layers.This function may only be called from softirq context and interrupts should be enabled.
Return values (usually ignored): NET_RX_SUCCESS: no congestion NET_RX_DROP: packet was dropped
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void
netif_receive_skb_list(struct list_head * head)¶ process many receive buffers from network
Parameters
struct list_head * head- list of skbs to process.
Description
Since return value of
netif_receive_skb()is normally ignored, and wouldn’t be meaningful for a list, this function returns void.This function may only be called from softirq context and interrupts should be enabled.
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void
__napi_schedule(struct napi_struct * n)¶ schedule for receive
Parameters
struct napi_struct * n- entry to schedule
Description
The entry’s receive function will be scheduled to run.
Consider using __napi_schedule_irqoff() if hard irqs are masked.
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bool
napi_schedule_prep(struct napi_struct * n)¶ check if napi can be scheduled
Parameters
struct napi_struct * n- napi context
Description
Test if NAPI routine is already running, and if not mark it as running. This is used as a condition variable insure only one NAPI poll instance runs. We also make sure there is no pending NAPI disable.
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void
__napi_schedule_irqoff(struct napi_struct * n)¶ schedule for receive
Parameters
struct napi_struct * n- entry to schedule
Description
Variant of __napi_schedule() assuming hard irqs are masked
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bool
netdev_has_upper_dev(struct net_device * dev, struct net_device * upper_dev)¶ Check if device is linked to an upper device
Parameters
struct net_device * dev- device
struct net_device * upper_dev- upper device to check
Description
Find out if a device is linked to specified upper device and return true in case it is. Note that this checks only immediate upper device, not through a complete stack of devices. The caller must hold the RTNL lock.
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bool
netdev_has_upper_dev_all_rcu(struct net_device * dev, struct net_device * upper_dev)¶ Check if device is linked to an upper device
Parameters
struct net_device * dev- device
struct net_device * upper_dev- upper device to check
Description
Find out if a device is linked to specified upper device and return true in case it is. Note that this checks the entire upper device chain. The caller must hold rcu lock.
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bool
netdev_has_any_upper_dev(struct net_device * dev)¶ Check if device is linked to some device
Parameters
struct net_device * dev- device
Description
Find out if a device is linked to an upper device and return true in case it is. The caller must hold the RTNL lock.
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struct net_device *
netdev_master_upper_dev_get(struct net_device * dev)¶ Get master upper device
Parameters
struct net_device * dev- device
Description
Find a master upper device and return pointer to it or NULL in case it’s not there. The caller must hold the RTNL lock.
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struct net_device *
netdev_upper_get_next_dev_rcu(struct net_device * dev, struct list_head ** iter)¶ Get the next dev from upper list
Parameters
struct net_device * dev- device
struct list_head ** iter- list_head ** of the current position
Description
Gets the next device from the dev’s upper list, starting from iter position. The caller must hold RCU read lock.
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void *
netdev_lower_get_next_private(struct net_device * dev, struct list_head ** iter)¶ Get the next ->private from the lower neighbour list
Parameters
struct net_device * dev- device
struct list_head ** iter- list_head ** of the current position
Description
Gets the next netdev_adjacent->private from the dev’s lower neighbour list, starting from iter position. The caller must hold either hold the RTNL lock or its own locking that guarantees that the neighbour lower list will remain unchanged.
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void *
netdev_lower_get_next_private_rcu(struct net_device * dev, struct list_head ** iter)¶ Get the next ->private from the lower neighbour list, RCU variant
Parameters
struct net_device * dev- device
struct list_head ** iter- list_head ** of the current position
Description
Gets the next netdev_adjacent->private from the dev’s lower neighbour list, starting from iter position. The caller must hold RCU read lock.
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void *
netdev_lower_get_next(struct net_device * dev, struct list_head ** iter)¶ Get the next device from the lower neighbour list
Parameters
struct net_device * dev- device
struct list_head ** iter- list_head ** of the current position
Description
Gets the next netdev_adjacent from the dev’s lower neighbour list, starting from iter position. The caller must hold RTNL lock or its own locking that guarantees that the neighbour lower list will remain unchanged.
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void *
netdev_lower_get_first_private_rcu(struct net_device * dev)¶ Get the first ->private from the lower neighbour list, RCU variant
Parameters
struct net_device * dev- device
Description
Gets the first netdev_adjacent->private from the dev’s lower neighbour list. The caller must hold RCU read lock.
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struct net_device *
netdev_master_upper_dev_get_rcu(struct net_device * dev)¶ Get master upper device
Parameters
struct net_device * dev- device
Description
Find a master upper device and return pointer to it or NULL in case it’s not there. The caller must hold the RCU read lock.
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int
netdev_upper_dev_link(struct net_device * dev, struct net_device * upper_dev, struct netlink_ext_ack * extack)¶ Add a link to the upper device
Parameters
struct net_device * dev- device
struct net_device * upper_dev- new upper device
struct netlink_ext_ack * extack- netlink extended ack
Description
Adds a link to device which is upper to this one. The caller must hold the RTNL lock. On a failure a negative errno code is returned. On success the reference counts are adjusted and the function returns zero.
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int
netdev_master_upper_dev_link(struct net_device * dev, struct net_device * upper_dev, void * upper_priv, void * upper_info, struct netlink_ext_ack * extack)¶ Add a master link to the upper device
Parameters
struct net_device * dev- device
struct net_device * upper_dev- new upper device
void * upper_priv- upper device private
void * upper_info- upper info to be passed down via notifier
struct netlink_ext_ack * extack- netlink extended ack
Description
Adds a link to device which is upper to this one. In this case, only one master upper device can be linked, although other non-master devices might be linked as well. The caller must hold the RTNL lock. On a failure a negative errno code is returned. On success the reference counts are adjusted and the function returns zero.
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void
netdev_upper_dev_unlink(struct net_device * dev, struct net_device * upper_dev)¶ Removes a link to upper device
Parameters
struct net_device * dev- device
struct net_device * upper_dev- new upper device
Description
Removes a link to device which is upper to this one. The caller must hold the RTNL lock.
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void
netdev_bonding_info_change(struct net_device * dev, struct netdev_bonding_info * bonding_info)¶ Dispatch event about slave change
Parameters
struct net_device * dev- device
struct netdev_bonding_info * bonding_info- info to dispatch
Description
Send NETDEV_BONDING_INFO to netdev notifiers with info. The caller must hold the RTNL lock.
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void
netdev_lower_state_changed(struct net_device * lower_dev, void * lower_state_info)¶ Dispatch event about lower device state change
Parameters
struct net_device * lower_dev- device
void * lower_state_info- state to dispatch
Description
Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info. The caller must hold the RTNL lock.
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int
dev_set_promiscuity(struct net_device * dev, int inc)¶ update promiscuity count on a device
Parameters
struct net_device * dev- device
int inc- modifier
Description
Add or remove promiscuity from a device. While the count in the device remains above zero the interface remains promiscuous. Once it hits zero the device reverts back to normal filtering operation. A negative inc value is used to drop promiscuity on the device. Return 0 if successful or a negative errno code on error.
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int
dev_set_allmulti(struct net_device * dev, int inc)¶ update allmulti count on a device
Parameters
struct net_device * dev- device
int inc- modifier
Description
Add or remove reception of all multicast frames to a device. While the count in the device remains above zero the interface remains listening to all interfaces. Once it hits zero the device reverts back to normal filtering operation. A negative inc value is used to drop the counter when releasing a resource needing all multicasts. Return 0 if successful or a negative errno code on error.
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unsigned int
dev_get_flags(const struct net_device * dev)¶ get flags reported to userspace
Parameters
const struct net_device * dev- device
Description
Get the combination of flag bits exported through APIs to userspace.
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int
dev_change_flags(struct net_device * dev, unsigned int flags, struct netlink_ext_ack * extack)¶ change device settings
Parameters
struct net_device * dev- device
unsigned int flags- device state flags
struct netlink_ext_ack * extack- netlink extended ack
Description
Change settings on device based state flags. The flags are in the userspace exported format.
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void
dev_set_group(struct net_device * dev, int new_group)¶ Change group this device belongs to
Parameters
struct net_device * dev- device
int new_group- group this device should belong to
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int
dev_pre_changeaddr_notify(struct net_device * dev, const char * addr, struct netlink_ext_ack * extack)¶ Call NETDEV_PRE_CHANGEADDR.
Parameters
struct net_device * dev- device
const char * addr- new address
struct netlink_ext_ack * extack- netlink extended ack
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int
dev_set_mac_address(struct net_device * dev, struct sockaddr * sa, struct netlink_ext_ack * extack)¶ Change Media Access Control Address
Parameters
struct net_device * dev- device
struct sockaddr * sa- new address
struct netlink_ext_ack * extack- netlink extended ack
Description
Change the hardware (MAC) address of the device
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int
dev_change_carrier(struct net_device * dev, bool new_carrier)¶ Change device carrier
Parameters
struct net_device * dev- device
bool new_carrier- new value
Description
Change device carrier
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int
dev_get_phys_port_id(struct net_device * dev, struct netdev_phys_item_id * ppid)¶ Get device physical port ID
Parameters
struct net_device * dev- device
struct netdev_phys_item_id * ppid- port ID
Description
Get device physical port ID
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int
dev_get_phys_port_name(struct net_device * dev, char * name, size_t len)¶ Get device physical port name
Parameters
struct net_device * dev- device
char * name- port name
size_t len- limit of bytes to copy to name
Description
Get device physical port name
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int
dev_get_port_parent_id(struct net_device * dev, struct netdev_phys_item_id * ppid, bool recurse)¶ Get the device’s port parent identifier
Parameters
struct net_device * dev- network device
struct netdev_phys_item_id * ppid- pointer to a storage for the port’s parent identifier
bool recurse- allow/disallow recursion to lower devices
Description
Get the devices’s port parent identifier
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bool
netdev_port_same_parent_id(struct net_device * a, struct net_device * b)¶ Indicate if two network devices have the same port parent identifier
Parameters
struct net_device * a- first network device
struct net_device * b- second network device
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int
dev_change_proto_down(struct net_device * dev, bool proto_down)¶ update protocol port state information
Parameters
struct net_device * dev- device
bool proto_down- new value
Description
This info can be used by switch drivers to set the phys state of the port.
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int
dev_change_proto_down_generic(struct net_device * dev, bool proto_down)¶ generic implementation for ndo_change_proto_down that sets carrier according to proto_down.
Parameters
struct net_device * dev- device
bool proto_down- new value
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void
netdev_update_features(struct net_device * dev)¶ recalculate device features
Parameters
struct net_device * dev- the device to check
Description
Recalculate dev->features set and send notifications if it has changed. Should be called after driver or hardware dependent conditions might have changed that influence the features.
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void
netdev_change_features(struct net_device * dev)¶ recalculate device features
Parameters
struct net_device * dev- the device to check
Description
Recalculate dev->features set and send notifications even if they have not changed. Should be called instead ofnetdev_update_features()if also dev->vlan_features might have changed to allow the changes to be propagated to stacked VLAN devices.
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void
netif_stacked_transfer_operstate(const struct net_device * rootdev, struct net_device * dev)¶ transfer operstate
Parameters
const struct net_device * rootdev- the root or lower level device to transfer state from
struct net_device * dev- the device to transfer operstate to
Description
Transfer operational state from root to device. This is normally called when a stacking relationship exists between the root device and the device(a leaf device).
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int
register_netdevice(struct net_device * dev)¶ register a network device
Parameters
struct net_device * dev- device to register
Description
Take a completed network device structure and add it to the kernel interfaces. A
NETDEV_REGISTERmessage is sent to the netdev notifier chain. 0 is returned on success. A negative errno code is returned on a failure to set up the device, or if the name is a duplicate.Callers must hold the rtnl semaphore. You may want
register_netdev()instead of this.BUGS: The locking appears insufficient to guarantee two parallel registers will not get the same name.
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int
init_dummy_netdev(struct net_device * dev)¶ init a dummy network device for NAPI
Parameters
struct net_device * dev- device to init
Description
This takes a network device structure and initialize the minimum amount of fields so it can be used to schedule NAPI polls without registering a full blown interface. This is to be used by drivers that need to tie several hardware interfaces to a single NAPI poll scheduler due to HW limitations.
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int
register_netdev(struct net_device * dev)¶ register a network device
Parameters
struct net_device * dev- device to register
Description
Take a completed network device structure and add it to the kernel interfaces. A
NETDEV_REGISTERmessage is sent to the netdev notifier chain. 0 is returned on success. A negative errno code is returned on a failure to set up the device, or if the name is a duplicate.This is a wrapper around register_netdevice that takes the rtnl semaphore and expands the device name if you passed a format string to alloc_netdev.
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struct rtnl_link_stats64 *
dev_get_stats(struct net_device * dev, struct rtnl_link_stats64 * storage)¶ get network device statistics
Parameters
struct net_device * dev- device to get statistics from
struct rtnl_link_stats64 * storage- place to store stats
Description
Get network statistics from device. Return storage. The device driver may provide its own method by setting dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats; otherwise the internal statistics structure is used.
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struct net_device *
alloc_netdev_mqs(int sizeof_priv, const char * name, unsigned char name_assign_type, void (*setup) (struct net_device *, unsigned int txqs, unsigned int rxqs)¶ allocate network device
Parameters
int sizeof_priv- size of private data to allocate space for
const char * name- device name format string
unsigned char name_assign_type- origin of device name
void (*)(struct net_device *) setup- callback to initialize device
unsigned int txqs- the number of TX subqueues to allocate
unsigned int rxqs- the number of RX subqueues to allocate
Description
Allocates a struct net_device with private data area for driver use and performs basic initialization. Also allocates subqueue structs for each queue on the device.
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void
free_netdev(struct net_device * dev)¶ free network device
Parameters
struct net_device * dev- device
Description
This function does the last stage of destroying an allocated device interface. The reference to the device object is released. If this is the last reference then it will be freed.Must be called in process context.
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void
synchronize_net(void)¶ Synchronize with packet receive processing
Parameters
void- no arguments
Description
Wait for packets currently being received to be done. Does not block later packets from starting.
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void
unregister_netdevice_queue(struct net_device * dev, struct list_head * head)¶ remove device from the kernel
Parameters
struct net_device * dev- device
struct list_head * head- list
Description
This function shuts down a device interface and removes it from the kernel tables. If head not NULL, device is queued to be unregistered later.
Callers must hold the rtnl semaphore. You may want
unregister_netdev()instead of this.
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void
unregister_netdevice_many(struct list_head * head)¶ unregister many devices
Parameters
struct list_head * head- list of devices
Note
- As most callers use a stack allocated list_head,
- we force a list_del() to make sure stack wont be corrupted later.
-
void
unregister_netdev(struct net_device * dev)¶ remove device from the kernel
Parameters
struct net_device * dev- device
Description
This function shuts down a device interface and removes it from the kernel tables.
This is just a wrapper for unregister_netdevice that takes the rtnl semaphore. In general you want to use this and not unregister_netdevice.
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int
dev_change_net_namespace(struct net_device * dev, struct net * net, const char * pat)¶ move device to different nethost namespace
Parameters
struct net_device * dev- device
struct net * net- network namespace
const char * pat- If not NULL name pattern to try if the current device name is already taken in the destination network namespace.
Description
This function shuts down a device interface and moves it to a new network namespace. On success 0 is returned, on a failure a netagive errno code is returned.
Callers must hold the rtnl semaphore.
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netdev_features_t
netdev_increment_features(netdev_features_t all, netdev_features_t one, netdev_features_t mask)¶ increment feature set by one
Parameters
netdev_features_t all- current feature set
netdev_features_t one- new feature set
netdev_features_t mask- mask feature set
Description
Computes a new feature set after adding a device with feature set one to the master device with current feature set all. Will not enable anything that is off in mask. Returns the new feature set.
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int
eth_header(struct sk_buff * skb, struct net_device * dev, unsigned short type, const void * daddr, const void * saddr, unsigned int len)¶ create the Ethernet header
Parameters
struct sk_buff * skb- buffer to alter
struct net_device * dev- source device
unsigned short type- Ethernet type field
const void * daddr- destination address (NULL leave destination address)
const void * saddr- source address (NULL use device source address)
unsigned int len- packet length (<= skb->len)
Description
Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length in here instead.
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u32
eth_get_headlen(const struct net_device * dev, void * data, unsigned int len)¶ determine the length of header for an ethernet frame
Parameters
const struct net_device * dev- pointer to network device
void * data- pointer to start of frame
unsigned int len- total length of frame
Description
Make a best effort attempt to pull the length for all of the headers for a given frame in a linear buffer.
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__be16
eth_type_trans(struct sk_buff * skb, struct net_device * dev)¶ determine the packet’s protocol ID.
Parameters
struct sk_buff * skb- received socket data
struct net_device * dev- receiving network device
Description
The rule here is that we assume 802.3 if the type field is short enough to be a length. This is normal practice and works for any ‘now in use’ protocol.
-
int
eth_header_parse(const struct sk_buff * skb, unsigned char * haddr)¶ extract hardware address from packet
Parameters
const struct sk_buff * skb- packet to extract header from
unsigned char * haddr- destination buffer
-
int
eth_header_cache(const struct neighbour * neigh, struct hh_cache * hh, __be16 type)¶ fill cache entry from neighbour
Parameters
const struct neighbour * neigh- source neighbour
struct hh_cache * hh- destination cache entry
__be16 type- Ethernet type field
Description
Create an Ethernet header template from the neighbour.
-
void
eth_header_cache_update(struct hh_cache * hh, const struct net_device * dev, const unsigned char * haddr)¶ update cache entry
Parameters
struct hh_cache * hh- destination cache entry
const struct net_device * dev- network device
const unsigned char * haddr- new hardware address
Description
Called by Address Resolution module to notify changes in address.
Parameters
const struct sk_buff * skb- packet to extract protocol from
-
int
eth_prepare_mac_addr_change(struct net_device * dev, void * p)¶ prepare for mac change
Parameters
struct net_device * dev- network device
void * p- socket address
-
void
eth_commit_mac_addr_change(struct net_device * dev, void * p)¶ commit mac change
Parameters
struct net_device * dev- network device
void * p- socket address
-
int
eth_mac_addr(struct net_device * dev, void * p)¶ set new Ethernet hardware address
Parameters
struct net_device * dev- network device
void * p- socket address
Description
Change hardware address of device.
This doesn’t change hardware matching, so needs to be overridden for most real devices.
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int
eth_change_mtu(struct net_device * dev, int new_mtu)¶ set new MTU size
Parameters
struct net_device * dev- network device
int new_mtu- new Maximum Transfer Unit
Description
Allow changing MTU size. Needs to be overridden for devices supporting jumbo frames.
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void
ether_setup(struct net_device * dev)¶ setup Ethernet network device
Parameters
struct net_device * dev- network device
Description
Fill in the fields of the device structure with Ethernet-generic values.
-
struct net_device *
alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, unsigned int rxqs)¶ Allocates and sets up an Ethernet device
Parameters
int sizeof_priv- Size of additional driver-private structure to be allocated for this Ethernet device
unsigned int txqs- The number of TX queues this device has.
unsigned int rxqs- The number of RX queues this device has.
Description
Fill in the fields of the device structure with Ethernet-generic values. Basically does everything except registering the device.
Constructs a new net device, complete with a private data area of size (sizeof_priv). A 32-byte (not bit) alignment is enforced for this private data area.
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int
nvmem_get_mac_address(struct device * dev, void * addrbuf)¶ address’ associated with given device.
Parameters
struct device * dev- Device with which the mac-address cell is associated.
void * addrbuf- Buffer to which the MAC address will be copied on success.
Description
Returns 0 on success or a negative error number on failure.
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void
netif_carrier_on(struct net_device * dev)¶ set carrier
Parameters
struct net_device * dev- network device
Description
Device has detected acquisition of carrier.
-
void
netif_carrier_off(struct net_device * dev)¶ clear carrier
Parameters
struct net_device * dev- network device
Description
Device has detected loss of carrier.
-
bool
is_link_local_ether_addr(const u8 * addr)¶ Determine if given Ethernet address is link-local
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if address is link local reserved addr (01:80:c2:00:00:0X) per IEEE 802.1Q 8.6.3 Frame filtering.
Please note: addr must be aligned to u16.
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bool
is_zero_ether_addr(const u8 * addr)¶ Determine if give Ethernet address is all zeros.
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if the address is all zeroes.
Please note: addr must be aligned to u16.
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bool
is_multicast_ether_addr(const u8 * addr)¶ Determine if the Ethernet address is a multicast.
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if the address is a multicast address. By definition the broadcast address is also a multicast address.
-
bool
is_local_ether_addr(const u8 * addr)¶ Determine if the Ethernet address is locally-assigned one (IEEE 802).
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if the address is a local address.
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bool
is_broadcast_ether_addr(const u8 * addr)¶ Determine if the Ethernet address is broadcast
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if the address is the broadcast address.
Please note: addr must be aligned to u16.
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bool
is_unicast_ether_addr(const u8 * addr)¶ Determine if the Ethernet address is unicast
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return true if the address is a unicast address.
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bool
is_valid_ether_addr(const u8 * addr)¶ Determine if the given Ethernet address is valid
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not a multicast address, and is not FF:FF:FF:FF:FF:FF.
Return true if the address is valid.
Please note: addr must be aligned to u16.
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bool
eth_proto_is_802_3(__be16 proto)¶ Determine if a given Ethertype/length is a protocol
Parameters
__be16 proto- Ethertype/length value to be tested
Description
Check that the value from the Ethertype/length field is a valid Ethertype.
Return true if the valid is an 802.3 supported Ethertype.
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void
eth_random_addr(u8 * addr)¶ Generate software assigned random Ethernet address
Parameters
u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Generate a random Ethernet address (MAC) that is not multicast and has the local assigned bit set.
-
void
eth_broadcast_addr(u8 * addr)¶ Assign broadcast address
Parameters
u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Assign the broadcast address to the given address array.
-
void
eth_zero_addr(u8 * addr)¶ Assign zero address
Parameters
u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Assign the zero address to the given address array.
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void
eth_hw_addr_random(struct net_device * dev)¶ Generate software assigned random Ethernet and set device flag
Parameters
struct net_device * dev- pointer to net_device structure
Description
Generate a random Ethernet address (MAC) to be used by a net device and set addr_assign_type so the state can be read by sysfs and be used by userspace.
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void
ether_addr_copy(u8 * dst, const u8 * src)¶ Copy an Ethernet address
Parameters
u8 * dst- Pointer to a six-byte array Ethernet address destination
const u8 * src- Pointer to a six-byte array Ethernet address source
Description
Please note: dst & src must both be aligned to u16.
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void
eth_hw_addr_inherit(struct net_device * dst, struct net_device * src)¶ Copy dev_addr from another net_device
Parameters
struct net_device * dst- pointer to net_device to copy dev_addr to
struct net_device * src- pointer to net_device to copy dev_addr from
Description
Copy the Ethernet address from one net_device to another along with the address attributes (addr_assign_type).
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bool
ether_addr_equal(const u8 * addr1, const u8 * addr2)¶ Compare two Ethernet addresses
Parameters
const u8 * addr1- Pointer to a six-byte array containing the Ethernet address
const u8 * addr2- Pointer other six-byte array containing the Ethernet address
Description
Compare two Ethernet addresses, returns true if equal
Please note: addr1 & addr2 must both be aligned to u16.
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bool
ether_addr_equal_64bits(const u8 addr1, const u8 addr2)¶ Compare two Ethernet addresses
Parameters
const u8 addr1- Pointer to an array of 8 bytes
const u8 addr2- Pointer to an other array of 8 bytes
Description
Compare two Ethernet addresses, returns true if equal, false otherwise.
The function doesn’t need any conditional branches and possibly uses word memory accesses on CPU allowing cheap unaligned memory reads. arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
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bool
ether_addr_equal_unaligned(const u8 * addr1, const u8 * addr2)¶ Compare two not u16 aligned Ethernet addresses
Parameters
const u8 * addr1- Pointer to a six-byte array containing the Ethernet address
const u8 * addr2- Pointer other six-byte array containing the Ethernet address
Description
Compare two Ethernet addresses, returns true if equal
Please note: Use only when any Ethernet address may not be u16 aligned.
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bool
ether_addr_equal_masked(const u8 * addr1, const u8 * addr2, const u8 * mask)¶ Compare two Ethernet addresses with a mask
Parameters
const u8 * addr1- Pointer to a six-byte array containing the 1st Ethernet address
const u8 * addr2- Pointer to a six-byte array containing the 2nd Ethernet address
const u8 * mask- Pointer to a six-byte array containing the Ethernet address bitmask
Description
Compare two Ethernet addresses with a mask, returns true if for every bit set in the bitmask the equivalent bits in the ethernet addresses are equal. Using a mask with all bits set is a slower ether_addr_equal.
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u64
ether_addr_to_u64(const u8 * addr)¶ Convert an Ethernet address into a u64 value.
Parameters
const u8 * addr- Pointer to a six-byte array containing the Ethernet address
Description
Return a u64 value of the address
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void
u64_to_ether_addr(u64 u, u8 * addr)¶ Convert a u64 to an Ethernet address.
Parameters
u64 u- u64 to convert to an Ethernet MAC address
u8 * addr- Pointer to a six-byte array to contain the Ethernet address
-
void
eth_addr_dec(u8 * addr)¶ Decrement the given MAC address
Parameters
u8 * addr- Pointer to a six-byte array containing Ethernet address to decrement
-
void
eth_addr_inc(u8 * addr)¶ Increment the given MAC address.
Parameters
u8 * addr- Pointer to a six-byte array containing Ethernet address to increment.
-
bool
is_etherdev_addr(const struct net_device * dev, const u8 addr)¶ Tell if given Ethernet address belongs to the device.
Parameters
const struct net_device * dev- Pointer to a device structure
const u8 addr- Pointer to a six-byte array containing the Ethernet address
Description
Compare passed address with all addresses of the device. Return true if the address if one of the device addresses.
Note that this function calls ether_addr_equal_64bits() so take care of
the right padding.
-
unsigned long
compare_ether_header(const void * a, const void * b)¶ Compare two Ethernet headers
Parameters
const void * a- Pointer to Ethernet header
const void * b- Pointer to Ethernet header
Description
Compare two Ethernet headers, returns 0 if equal. This assumes that the network header (i.e., IP header) is 4-byte aligned OR the platform can handle unaligned access. This is the case for all packets coming into netif_receive_skb or similar entry points.
Parameters
struct sk_buff * skb- Buffer to pad
Description
An Ethernet frame should have a minimum size of 60 bytes. This function takes short frames and pads them with zeros up to the 60 byte limit.
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void
napi_schedule(struct napi_struct * n)¶ schedule NAPI poll
Parameters
struct napi_struct * n- NAPI context
Description
Schedule NAPI poll routine to be called if it is not already running.
-
void
napi_schedule_irqoff(struct napi_struct * n)¶ schedule NAPI poll
Parameters
struct napi_struct * n- NAPI context
Description
Variant of napi_schedule(), assuming hard irqs are masked.
-
bool
napi_complete(struct napi_struct * n)¶ NAPI processing complete
Parameters
struct napi_struct * n- NAPI context
Description
Mark NAPI processing as complete. Consider using napi_complete_done() instead. Return false if device should avoid rearming interrupts.
-
bool
napi_hash_del(struct napi_struct * napi)¶ remove a NAPI from global table
Parameters
struct napi_struct * napi- NAPI context
Description
Warning: caller must observe RCU grace period before freeing memory containing napi, if this function returns true.
Note
core networking stack automatically calls it
from netif_napi_del().
Drivers might want to call this helper to combine all
the needed RCU grace periods into a single one.
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void
napi_disable(struct napi_struct * n)¶ prevent NAPI from scheduling
Parameters
struct napi_struct * n- NAPI context
Description
Stop NAPI from being scheduled on this context. Waits till any outstanding processing completes.
-
void
napi_enable(struct napi_struct * n)¶ enable NAPI scheduling
Parameters
struct napi_struct * n- NAPI context
Description
Resume NAPI from being scheduled on this context. Must be paired with napi_disable.
-
void
napi_synchronize(const struct napi_struct * n)¶ wait until NAPI is not running
Parameters
const struct napi_struct * n- NAPI context
Description
Wait until NAPI is done being scheduled on this context. Waits till any outstanding processing completes but does not disable future activations.
-
bool
napi_if_scheduled_mark_missed(struct napi_struct * n)¶ if napi is running, set the NAPIF_STATE_MISSED
Parameters
struct napi_struct * n- NAPI context
Description
If napi is running, set the NAPIF_STATE_MISSED, and return true if NAPI is scheduled.
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enum
netdev_priv_flags¶ struct net_devicepriv_flags
Constants
IFF_802_1Q_VLAN- 802.1Q VLAN device
IFF_EBRIDGE- Ethernet bridging device
IFF_BONDING- bonding master or slave
IFF_ISATAP- ISATAP interface (RFC4214)
IFF_WAN_HDLC- WAN HDLC device
IFF_XMIT_DST_RELEASE- dev_hard_start_xmit() is allowed to release skb->dst
IFF_DONT_BRIDGE- disallow bridging this ether dev
IFF_DISABLE_NETPOLL- disable netpoll at run-time
IFF_MACVLAN_PORT- device used as macvlan port
IFF_BRIDGE_PORT- device used as bridge port
IFF_OVS_DATAPATH- device used as Open vSwitch datapath port
IFF_TX_SKB_SHARING- The interface supports sharing skbs on transmit
IFF_UNICAST_FLT- Supports unicast filtering
IFF_TEAM_PORT- device used as team port
IFF_SUPP_NOFCS- device supports sending custom FCS
IFF_LIVE_ADDR_CHANGE- device supports hardware address change when it’s running
IFF_MACVLAN- Macvlan device
IFF_XMIT_DST_RELEASE_PERM- IFF_XMIT_DST_RELEASE not taking into account underlying stacked devices
IFF_L3MDEV_MASTER- device is an L3 master device
IFF_NO_QUEUE- device can run without qdisc attached
IFF_OPENVSWITCH- device is a Open vSwitch master
IFF_L3MDEV_SLAVE- device is enslaved to an L3 master device
IFF_TEAM- device is a team device
IFF_RXFH_CONFIGURED- device has had Rx Flow indirection table configured
IFF_PHONY_HEADROOM- the headroom value is controlled by an external entity (i.e. the master device for bridged veth)
IFF_MACSEC- device is a MACsec device
IFF_NO_RX_HANDLER- device doesn’t support the rx_handler hook
IFF_FAILOVER- device is a failover master device
IFF_FAILOVER_SLAVE- device is lower dev of a failover master device
IFF_L3MDEV_RX_HANDLER- only invoke the rx handler of L3 master device
IFF_LIVE_RENAME_OK- rename is allowed while device is up and running
Description
These are the struct net_device, they are only set internally
by drivers and used in the kernel. These flags are invisible to
userspace; this means that the order of these flags can change
during any kernel release.
You should have a pretty good reason to be extending these flags.
-
struct
net_device¶ The DEVICE structure.
Definition
struct net_device {
char name[IFNAMSIZ];
struct hlist_node name_hlist;
struct dev_ifalias __rcu *ifalias;
unsigned long mem_end;
unsigned long mem_start;
unsigned long base_addr;
int irq;
unsigned long state;
struct list_head dev_list;
struct list_head napi_list;
struct list_head unreg_list;
struct list_head close_list;
struct list_head ptype_all;
struct list_head ptype_specific;
struct {
struct list_head upper;
struct list_head lower;
} adj_list;
netdev_features_t features;
netdev_features_t hw_features;
netdev_features_t wanted_features;
netdev_features_t vlan_features;
netdev_features_t hw_enc_features;
netdev_features_t mpls_features;
netdev_features_t gso_partial_features;
int ifindex;
int group;
struct net_device_stats stats;
atomic_long_t rx_dropped;
atomic_long_t tx_dropped;
atomic_long_t rx_nohandler;
atomic_t carrier_up_count;
atomic_t carrier_down_count;
#ifdef CONFIG_WIRELESS_EXT;
const struct iw_handler_def *wireless_handlers;
struct iw_public_data *wireless_data;
#endif;
const struct net_device_ops *netdev_ops;
const struct ethtool_ops *ethtool_ops;
#ifdef CONFIG_NET_L3_MASTER_DEV;
const struct l3mdev_ops *l3mdev_ops;
#endif;
#if IS_ENABLED(CONFIG_IPV6);
const struct ndisc_ops *ndisc_ops;
#endif;
#ifdef CONFIG_XFRM_OFFLOAD;
const struct xfrmdev_ops *xfrmdev_ops;
#endif;
#if IS_ENABLED(CONFIG_TLS_DEVICE);
const struct tlsdev_ops *tlsdev_ops;
#endif;
const struct header_ops *header_ops;
unsigned int flags;
unsigned int priv_flags;
unsigned short gflags;
unsigned short padded;
unsigned char operstate;
unsigned char link_mode;
unsigned char if_port;
unsigned char dma;
unsigned int mtu;
unsigned int min_mtu;
unsigned int max_mtu;
unsigned short type;
unsigned short hard_header_len;
unsigned char min_header_len;
unsigned short needed_headroom;
unsigned short needed_tailroom;
unsigned char perm_addr[MAX_ADDR_LEN];
unsigned char addr_assign_type;
unsigned char addr_len;
unsigned short neigh_priv_len;
unsigned short dev_id;
unsigned short dev_port;
spinlock_t addr_list_lock;
unsigned char name_assign_type;
bool uc_promisc;
struct netdev_hw_addr_list uc;
struct netdev_hw_addr_list mc;
struct netdev_hw_addr_list dev_addrs;
#ifdef CONFIG_SYSFS;
struct kset *queues_kset;
#endif;
unsigned int promiscuity;
unsigned int allmulti;
#if IS_ENABLED(CONFIG_VLAN_8021Q);
struct vlan_info __rcu *vlan_info;
#endif;
#if IS_ENABLED(CONFIG_NET_DSA);
struct dsa_port *dsa_ptr;
#endif;
#if IS_ENABLED(CONFIG_TIPC);
struct tipc_bearer __rcu *tipc_ptr;
#endif;
#if IS_ENABLED(CONFIG_IRDA) || IS_ENABLED(CONFIG_ATALK);
void *atalk_ptr;
#endif;
struct in_device __rcu *ip_ptr;
#if IS_ENABLED(CONFIG_DECNET);
struct dn_dev __rcu *dn_ptr;
#endif;
struct inet6_dev __rcu *ip6_ptr;
#if IS_ENABLED(CONFIG_AX25);
void *ax25_ptr;
#endif;
struct wireless_dev *ieee80211_ptr;
struct wpan_dev *ieee802154_ptr;
#if IS_ENABLED(CONFIG_MPLS_ROUTING);
struct mpls_dev __rcu *mpls_ptr;
#endif;
unsigned char *dev_addr;
struct netdev_rx_queue *_rx;
unsigned int num_rx_queues;
unsigned int real_num_rx_queues;
struct bpf_prog __rcu *xdp_prog;
unsigned long gro_flush_timeout;
rx_handler_func_t __rcu *rx_handler;
void __rcu *rx_handler_data;
#ifdef CONFIG_NET_CLS_ACT;
struct mini_Qdisc __rcu *miniq_ingress;
#endif;
struct netdev_queue __rcu *ingress_queue;
#ifdef CONFIG_NETFILTER_INGRESS;
struct nf_hook_entries __rcu *nf_hooks_ingress;
#endif;
unsigned char broadcast[MAX_ADDR_LEN];
#ifdef CONFIG_RFS_ACCEL;
struct cpu_rmap *rx_cpu_rmap;
#endif;
struct hlist_node index_hlist;
struct netdev_queue *_tx ____cacheline_aligned_in_smp;
unsigned int num_tx_queues;
unsigned int real_num_tx_queues;
struct Qdisc *qdisc;
#ifdef CONFIG_NET_SCHED;
unsigned long qdisc_hash[1 << ((4) - 1)];
#endif;
unsigned int tx_queue_len;
spinlock_t tx_global_lock;
int watchdog_timeo;
#ifdef CONFIG_XPS;
struct xps_dev_maps __rcu *xps_cpus_map;
struct xps_dev_maps __rcu *xps_rxqs_map;
#endif;
#ifdef CONFIG_NET_CLS_ACT;
struct mini_Qdisc __rcu *miniq_egress;
#endif;
struct timer_list watchdog_timer;
int __percpu *pcpu_refcnt;
struct list_head todo_list;
struct list_head link_watch_list;
enum {
NETREG_UNINITIALIZED=0,
NETREG_REGISTERED,
NETREG_UNREGISTERING,
NETREG_UNREGISTERED,
NETREG_RELEASED,
NETREG_DUMMY,
} reg_state:8;
bool dismantle;
enum {
RTNL_LINK_INITIALIZED,
RTNL_LINK_INITIALIZING,
} rtnl_link_state:16;
bool needs_free_netdev;
void (*priv_destructor)(struct net_device *dev);
#ifdef CONFIG_NETPOLL;
struct netpoll_info __rcu *npinfo;
#endif;
possible_net_t nd_net;
union {
void *ml_priv;
struct pcpu_lstats __percpu *lstats;
struct pcpu_sw_netstats __percpu *tstats;
struct pcpu_dstats __percpu *dstats;
};
#if IS_ENABLED(CONFIG_GARP);
struct garp_port __rcu *garp_port;
#endif;
#if IS_ENABLED(CONFIG_MRP);
struct mrp_port __rcu *mrp_port;
#endif;
struct device dev;
const struct attribute_group *sysfs_groups[4];
const struct attribute_group *sysfs_rx_queue_group;
const struct rtnl_link_ops *rtnl_link_ops;
#define GSO_MAX_SIZE 65536;
unsigned int gso_max_size;
#define GSO_MAX_SEGS 65535;
u16 gso_max_segs;
#ifdef CONFIG_DCB;
const struct dcbnl_rtnl_ops *dcbnl_ops;
#endif;
s16 num_tc;
struct netdev_tc_txq tc_to_txq[TC_MAX_QUEUE];
u8 prio_tc_map[TC_BITMASK + 1];
#if IS_ENABLED(CONFIG_FCOE);
unsigned int fcoe_ddp_xid;
#endif;
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO);
struct netprio_map __rcu *priomap;
#endif;
struct phy_device *phydev;
struct sfp_bus *sfp_bus;
struct lock_class_key *qdisc_tx_busylock;
struct lock_class_key *qdisc_running_key;
bool proto_down;
unsigned wol_enabled:1;
};
Members
name- This is the first field of the “visible” part of this structure (i.e. as seen by users in the “Space.c” file). It is the name of the interface.
name_hlist- Device name hash chain, please keep it close to name[]
ifalias- SNMP alias
mem_end- Shared memory end
mem_start- Shared memory start
base_addr- Device I/O address
irq- Device IRQ number
state- Generic network queuing layer state, see netdev_state_t
dev_list- The global list of network devices
napi_list- List entry used for polling NAPI devices
unreg_list- List entry when we are unregistering the device; see the function unregister_netdev
close_list- List entry used when we are closing the device
ptype_all- Device-specific packet handlers for all protocols
ptype_specific- Device-specific, protocol-specific packet handlers
adj_list- Directly linked devices, like slaves for bonding
features- Currently active device features
hw_features- User-changeable features
wanted_features- User-requested features
vlan_features- Mask of features inheritable by VLAN devices
hw_enc_features- Mask of features inherited by encapsulating devices This field indicates what encapsulation offloads the hardware is capable of doing, and drivers will need to set them appropriately.
mpls_features- Mask of features inheritable by MPLS
ifindex- interface index
group- The group the device belongs to
stats- Statistics struct, which was left as a legacy, use rtnl_link_stats64 instead
rx_dropped- Dropped packets by core network, do not use this in drivers
tx_dropped- Dropped packets by core network, do not use this in drivers
rx_nohandler- nohandler dropped packets by core network on inactive devices, do not use this in drivers
carrier_up_count- Number of times the carrier has been up
carrier_down_count- Number of times the carrier has been down
wireless_handlers- List of functions to handle Wireless Extensions, instead of ioctl, see <net/iw_handler.h> for details.
wireless_data- Instance data managed by the core of wireless extensions
netdev_ops- Includes several pointers to callbacks, if one wants to override the ndo_*() functions
ethtool_ops- Management operations
ndisc_ops- Includes callbacks for different IPv6 neighbour discovery handling. Necessary for e.g. 6LoWPAN.
header_ops- Includes callbacks for creating,parsing,caching,etc of Layer 2 headers.
flags- Interface flags (a la BSD)
priv_flags- Like ‘flags’ but invisible to userspace, see if.h for the definitions
gflags- Global flags ( kept as legacy )
padded- How much padding added by alloc_netdev()
operstate- RFC2863 operstate
link_mode- Mapping policy to operstate
if_port- Selectable AUI, TP, …
dma- DMA channel
mtu- Interface MTU value
min_mtu- Interface Minimum MTU value
max_mtu- Interface Maximum MTU value
type- Interface hardware type
hard_header_len- Maximum hardware header length.
min_header_len- Minimum hardware header length
needed_headroom- Extra headroom the hardware may need, but not in all cases can this be guaranteed
needed_tailroom- Extra tailroom the hardware may need, but not in all cases can this be guaranteed. Some cases also use LL_MAX_HEADER instead to allocate the skb
perm_addr- Permanent hw address
addr_assign_type- Hw address assignment type
addr_len- Hardware address length
neigh_priv_len- Used in neigh_alloc()
dev_id- Used to differentiate devices that share the same link layer address
dev_port- Used to differentiate devices that share the same function
addr_list_lock- XXX: need comments on this one
uc_promisc- Counter that indicates promiscuous mode has been enabled due to the need to listen to additional unicast addresses in a device that does not implement ndo_set_rx_mode()
uc- unicast mac addresses
mc- multicast mac addresses
dev_addrs- list of device hw addresses
queues_kset- Group of all Kobjects in the Tx and RX queues
promiscuity- Number of times the NIC is told to work in promiscuous mode; if it becomes 0 the NIC will exit promiscuous mode
allmulti- Counter, enables or disables allmulticast mode
vlan_info- VLAN info
dsa_ptr- dsa specific data
tipc_ptr- TIPC specific data
atalk_ptr- AppleTalk link
ip_ptr- IPv4 specific data
dn_ptr- DECnet specific data
ip6_ptr- IPv6 specific data
ax25_ptr- AX.25 specific data
ieee80211_ptr- IEEE 802.11 specific data, assign before registering
dev_addr- Hw address (before bcast, because most packets are unicast)
_rx- Array of RX queues
num_rx_queues- Number of RX queues
allocated at
register_netdev()time real_num_rx_queues- Number of RX queues currently active in device
rx_handler- handler for received packets
rx_handler_data- XXX: need comments on this one
miniq_ingress- ingress/clsact qdisc specific data for ingress processing
ingress_queue- XXX: need comments on this one
broadcast- hw bcast address
rx_cpu_rmap- CPU reverse-mapping for RX completion interrupts, indexed by RX queue number. Assigned by driver. This must only be set if the ndo_rx_flow_steer operation is defined
index_hlist- Device index hash chain
num_tx_queues- Number of TX queues allocated at alloc_netdev_mq() time
real_num_tx_queues- Number of TX queues currently active in device
qdisc- Root qdisc from userspace point of view
tx_queue_len- Max frames per queue allowed
tx_global_lock- XXX: need comments on this one
watchdog_timeo- Represents the timeout that is used by the watchdog (see dev_watchdog())
miniq_egress- clsact qdisc specific data for egress processing
watchdog_timer- List of timers
pcpu_refcnt- Number of references to this device
todo_list- Delayed register/unregister
link_watch_list- XXX: need comments on this one
reg_state- Register/unregister state machine
dismantle- Device is going to be freed
rtnl_link_state- This enum represents the phases of creating a new link
needs_free_netdev- Should unregister perform free_netdev?
priv_destructor- Called from unregister
npinfo- XXX: need comments on this one
nd_net- Network namespace this network device is inside
{unnamed_union}- anonymous
ml_priv- Mid-layer private
lstats- Loopback statistics
tstats- Tunnel statistics
dstats- Dummy statistics
garp_port- GARP
mrp_port- MRP
dev- Class/net/name entry
sysfs_groups- Space for optional device, statistics and wireless sysfs groups
sysfs_rx_queue_group- Space for optional per-rx queue attributes
rtnl_link_ops- Rtnl_link_ops
gso_max_size- Maximum size of generic segmentation offload
gso_max_segs- Maximum number of segments that can be passed to the NIC for GSO
dcbnl_ops- Data Center Bridging netlink ops
num_tc- Number of traffic classes in the net device
tc_to_txq- XXX: need comments on this one
prio_tc_map- XXX: need comments on this one
fcoe_ddp_xid- Max exchange id for FCoE LRO by ddp
priomap- XXX: need comments on this one
phydev- Physical device may attach itself for hardware timestamping
sfp_bus- attached
struct sfp_busstructure. qdisc_tx_busylock- lockdep class annotating Qdisc->busylock spinlock
qdisc_running_key- lockdep class annotating Qdisc->running seqcount
proto_down- protocol port state information can be sent to the switch driver and used to set the phys state of the switch port.
wol_enabled- Wake-on-LAN is enabled
Description
Actually, this whole structure is a big mistake. It mixes I/O data with strictly “high-level” data, and it has to know about almost every data structure used in the INET module.
interface address info:
FIXME: cleanup struct net_device such that network protocol info moves out.
-
void *
netdev_priv(const struct net_device * dev)¶ access network device private data
Parameters
const struct net_device * dev- network device
Description
Get network device private data
-
void
netif_napi_add(struct net_device * dev, struct napi_struct * napi, int (*poll) (struct napi_struct *, int, int weight)¶ initialize a NAPI context
Parameters
struct net_device * dev- network device
struct napi_struct * napi- NAPI context
int (*)(struct napi_struct *, int) poll- polling function
int weight- default weight
Description
netif_napi_add() must be used to initialize a NAPI context prior to calling
any of the other NAPI-related functions.
-
void
netif_tx_napi_add(struct net_device * dev, struct napi_struct * napi, int (*poll) (struct napi_struct *, int, int weight)¶ initialize a NAPI context
Parameters
struct net_device * dev- network device
struct napi_struct * napi- NAPI context
int (*)(struct napi_struct *, int) poll- polling function
int weight- default weight
Description
This variant of netif_napi_add() should be used from drivers using NAPI
to exclusively poll a TX queue.
This will avoid we add it into napi_hash[], thus polluting this hash table.
-
void
netif_napi_del(struct napi_struct * napi)¶ remove a NAPI context
Parameters
struct napi_struct * napi- NAPI context
Description
netif_napi_del()removes a NAPI context from the network device NAPI list
-
void
netif_start_queue(struct net_device * dev)¶ allow transmit
Parameters
struct net_device * dev- network device
Description
Allow upper layers to call the device hard_start_xmit routine.
-
void
netif_wake_queue(struct net_device * dev)¶ restart transmit
Parameters
struct net_device * dev- network device
Description
Allow upper layers to call the device hard_start_xmit routine. Used for flow control when transmit resources are available.
-
void
netif_stop_queue(struct net_device * dev)¶ stop transmitted packets
Parameters
struct net_device * dev- network device
Description
Stop upper layers calling the device hard_start_xmit routine. Used for flow control when transmit resources are unavailable.
-
bool
netif_queue_stopped(const struct net_device * dev)¶ test if transmit queue is flowblocked
Parameters
const struct net_device * dev- network device
Description
Test if transmit queue on device is currently unable to send.
-
void
netdev_txq_bql_enqueue_prefetchw(struct netdev_queue * dev_queue)¶ prefetch bql data for write
Parameters
struct netdev_queue * dev_queue- pointer to transmit queue
Description
BQL enabled drivers might use this helper in their ndo_start_xmit(), to give appropriate hint to the CPU.
-
void
netdev_txq_bql_complete_prefetchw(struct netdev_queue * dev_queue)¶ prefetch bql data for write
Parameters
struct netdev_queue * dev_queue- pointer to transmit queue
Description
BQL enabled drivers might use this helper in their TX completion path, to give appropriate hint to the CPU.
-
void
netdev_sent_queue(struct net_device * dev, unsigned int bytes)¶ report the number of bytes queued to hardware
Parameters
struct net_device * dev- network device
unsigned int bytes- number of bytes queued to the hardware device queue
Description
Report the number of bytes queued for sending/completion to the network device hardware queue. bytes should be a good approximation and should exactly matchnetdev_completed_queue()bytes
-
void
netdev_completed_queue(struct net_device * dev, unsigned int pkts, unsigned int bytes)¶ report bytes and packets completed by device
Parameters
struct net_device * dev- network device
unsigned int pkts- actual number of packets sent over the medium
unsigned int bytes- actual number of bytes sent over the medium
Description
Report the number of bytes and packets transmitted by the network device hardware queue over the physical medium, bytes must exactly match the bytes amount passed tonetdev_sent_queue()
-
void
netdev_reset_queue(struct net_device * dev_queue)¶ reset the packets and bytes count of a network device
Parameters
struct net_device * dev_queue- network device
Description
Reset the bytes and packet count of a network device and clear the software flow control OFF bit for this network device
-
u16
netdev_cap_txqueue(struct net_device * dev, u16 queue_index)¶ check if selected tx queue exceeds device queues
Parameters
struct net_device * dev- network device
u16 queue_index- given tx queue index
Description
Returns 0 if given tx queue index >= number of device tx queues, otherwise returns the originally passed tx queue index.
-
bool
netif_running(const struct net_device * dev)¶ test if up
Parameters
const struct net_device * dev- network device
Description
Test if the device has been brought up.
-
void
netif_start_subqueue(struct net_device * dev, u16 queue_index)¶ allow sending packets on subqueue
Parameters
struct net_device * dev- network device
u16 queue_index- sub queue index
Description
Start individual transmit queue of a device with multiple transmit queues.
-
void
netif_stop_subqueue(struct net_device * dev, u16 queue_index)¶ stop sending packets on subqueue
Parameters
struct net_device * dev- network device
u16 queue_index- sub queue index
Description
Stop individual transmit queue of a device with multiple transmit queues.
-
bool
__netif_subqueue_stopped(const struct net_device * dev, u16 queue_index)¶ test status of subqueue
Parameters
const struct net_device * dev- network device
u16 queue_index- sub queue index
Description
Check individual transmit queue of a device with multiple transmit queues.
-
void
netif_wake_subqueue(struct net_device * dev, u16 queue_index)¶ allow sending packets on subqueue
Parameters
struct net_device * dev- network device
u16 queue_index- sub queue index
Description
Resume individual transmit queue of a device with multiple transmit queues.
-
bool
netif_attr_test_mask(unsigned long j, const unsigned long * mask, unsigned int nr_bits)¶ Test a CPU or Rx queue set in a mask
Parameters
unsigned long j- CPU/Rx queue index
const unsigned long * mask- bitmask of all cpus/rx queues
unsigned int nr_bits- number of bits in the bitmask
Description
Test if a CPU or Rx queue index is set in a mask of all CPU/Rx queues.
-
bool
netif_attr_test_online(unsigned long j, const unsigned long * online_mask, unsigned int nr_bits)¶ Test for online CPU/Rx queue
Parameters
unsigned long j- CPU/Rx queue index
const unsigned long * online_mask- bitmask for CPUs/Rx queues that are online
unsigned int nr_bits- number of bits in the bitmask
Description
Returns true if a CPU/Rx queue is online.
-
unsigned int
netif_attrmask_next(int n, const unsigned long * srcp, unsigned int nr_bits)¶ get the next CPU/Rx queue in a cpu/Rx queues mask
Parameters
int n- CPU/Rx queue index
const unsigned long * srcp- the cpumask/Rx queue mask pointer
unsigned int nr_bits- number of bits in the bitmask
Description
Returns >= nr_bits if no further CPUs/Rx queues set.
-
int
netif_attrmask_next_and(int n, const unsigned long * src1p, const unsigned long * src2p, unsigned int nr_bits)¶
Parameters
int n- CPU/Rx queue index
const unsigned long * src1p- the first CPUs/Rx queues mask pointer
const unsigned long * src2p- the second CPUs/Rx queues mask pointer
unsigned int nr_bits- number of bits in the bitmask
Description
Returns >= nr_bits if no further CPUs/Rx queues set in both.
-
bool
netif_is_multiqueue(const struct net_device * dev)¶ test if device has multiple transmit queues
Parameters
const struct net_device * dev- network device
Description
Check if device has multiple transmit queues
-
void
dev_put(struct net_device * dev)¶ release reference to device
Parameters
struct net_device * dev- network device
Description
Release reference to device to allow it to be freed.
-
void
dev_hold(struct net_device * dev)¶ get reference to device
Parameters
struct net_device * dev- network device
Description
Hold reference to device to keep it from being freed.
-
bool
netif_carrier_ok(const struct net_device * dev)¶ test if carrier present
Parameters
const struct net_device * dev- network device
Description
Check if carrier is present on device
-
void
netif_dormant_on(struct net_device * dev)¶ mark device as dormant.
Parameters
struct net_device * dev- network device
Description
Mark device as dormant (as per RFC2863).
The dormant state indicates that the relevant interface is not actually in a condition to pass packets (i.e., it is not ‘up’) but is in a “pending” state, waiting for some external event. For “on- demand” interfaces, this new state identifies the situation where the interface is waiting for events to place it in the up state.
-
void
netif_dormant_off(struct net_device * dev)¶ set device as not dormant.
Parameters
struct net_device * dev- network device
Description
Device is not in dormant state.
-
bool
netif_dormant(const struct net_device * dev)¶ test if device is dormant
Parameters
const struct net_device * dev- network device
Description
Check if device is dormant.
-
bool
netif_oper_up(const struct net_device * dev)¶ test if device is operational
Parameters
const struct net_device * dev- network device
Description
Check if carrier is operational
-
bool
netif_device_present(struct net_device * dev)¶ is device available or removed
Parameters
struct net_device * dev- network device
Description
Check if device has not been removed from system.
-
void
netif_tx_lock(struct net_device * dev)¶ grab network device transmit lock
Parameters
struct net_device * dev- network device
Description
Get network device transmit lock
-
int
__dev_uc_sync(struct net_device * dev, int (*sync) (struct net_device *, const unsigned char *, int (*unsync) (struct net_device *, const unsigned char *)¶ Synchonize device’s unicast list
Parameters
struct net_device * dev- device to sync
int (*)(struct net_device *, const unsigned char *) sync- function to call if address should be added
int (*)(struct net_device *, const unsigned char *) unsync- function to call if address should be removed
Description
Add newly added addresses to the interface, and release addresses that have been deleted.
-
void
__dev_uc_unsync(struct net_device * dev, int (*unsync) (struct net_device *, const unsigned char *)¶ Remove synchronized addresses from device
Parameters
struct net_device * dev- device to sync
int (*)(struct net_device *, const unsigned char *) unsync- function to call if address should be removed
Description
Remove all addresses that were added to the device by dev_uc_sync().
-
int
__dev_mc_sync(struct net_device * dev, int (*sync) (struct net_device *, const unsigned char *, int (*unsync) (struct net_device *, const unsigned char *)¶ Synchonize device’s multicast list
Parameters
struct net_device * dev- device to sync
int (*)(struct net_device *, const unsigned char *) sync- function to call if address should be added
int (*)(struct net_device *, const unsigned char *) unsync- function to call if address should be removed
Description
Add newly added addresses to the interface, and release addresses that have been deleted.
-
void
__dev_mc_unsync(struct net_device * dev, int (*unsync) (struct net_device *, const unsigned char *)¶ Remove synchronized addresses from device
Parameters
struct net_device * dev- device to sync
int (*)(struct net_device *, const unsigned char *) unsync- function to call if address should be removed
Description
Remove all addresses that were added to the device by dev_mc_sync().
PHY Support¶
-
void
phy_print_status(struct phy_device * phydev)¶ Convenience function to print out the current phy status
Parameters
struct phy_device * phydev- the phy_device struct
-
int
phy_restart_aneg(struct phy_device * phydev)¶ restart auto-negotiation
Parameters
struct phy_device * phydev- target phy_device struct
Description
Restart the autonegotiation on phydev. Returns >= 0 on success or negative errno on error.
-
int
phy_aneg_done(struct phy_device * phydev)¶ return auto-negotiation status
Parameters
struct phy_device * phydev- target phy_device struct
Description
Return the auto-negotiation status from this phydev Returns > 0 on success or < 0 on error. 0 means that auto-negotiation is still pending.
-
int
phy_ethtool_sset(struct phy_device * phydev, struct ethtool_cmd * cmd)¶ generic ethtool sset function, handles all the details
Parameters
struct phy_device * phydev- target phy_device struct
struct ethtool_cmd * cmd- ethtool_cmd
Description
A few notes about parameter checking:
- We don’t set port or transceiver, so we don’t care what they were set to.
phy_start_aneg()will make sure forced settings are sane, and choose the next best ones from the ones selected, so we don’t care if ethtool tries to give us bad values.
-
int
phy_mii_ioctl(struct phy_device * phydev, struct ifreq * ifr, int cmd)¶ generic PHY MII ioctl interface
Parameters
struct phy_device * phydev- the phy_device struct
struct ifreq * ifrstruct ifreqfor socket ioctl’sint cmd- ioctl cmd to execute
Description
Note that this function is currently incompatible with the PHYCONTROL layer. It changes registers without regard to current state. Use at own risk.
-
int
phy_start_aneg(struct phy_device * phydev)¶ start auto-negotiation for this PHY device
Parameters
struct phy_device * phydev- the phy_device struct
Description
- Sanitizes the settings (if we’re not autonegotiating
- them), and then calls the driver’s config_aneg function. If the PHYCONTROL Layer is operating, we change the state to reflect the beginning of Auto-negotiation or forcing.
-
int
phy_speed_down(struct phy_device * phydev, bool sync)¶ set speed to lowest speed supported by both link partners
Parameters
struct phy_device * phydev- the phy_device struct
bool sync- perform action synchronously
Description
Typically used to save energy when waiting for a WoL packet
WARNING: Setting sync to false may cause the system being unable to suspend in case the PHY generates an interrupt when finishing the autonegotiation. This interrupt may wake up the system immediately after suspend. Therefore use sync = false only if you’re sure it’s safe with the respective network chip.
-
int
phy_speed_up(struct phy_device * phydev)¶ (re)set advertised speeds to all supported speeds
Parameters
struct phy_device * phydev- the phy_device struct
Description
Used to revert the effect of phy_speed_down
-
void
phy_start_machine(struct phy_device * phydev)¶ start PHY state machine tracking
Parameters
struct phy_device * phydev- the phy_device struct
Description
- The PHY infrastructure can run a state machine
- which tracks whether the PHY is starting up, negotiating, etc. This function starts the delayed workqueue which tracks the state of the PHY. If you want to maintain your own state machine, do not call this function.
-
void
phy_request_interrupt(struct phy_device * phydev)¶ request and enable interrupt for a PHY device
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Request and enable the interrupt for the given PHY.
- If this fails, then we set irq to PHY_POLL. This should only be called with a valid IRQ number.
-
void
phy_free_interrupt(struct phy_device * phydev)¶ disable and free interrupt for a PHY device
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Disable and free the interrupt for the given PHY.
- This should only be called with a valid IRQ number.
-
void
phy_stop(struct phy_device * phydev)¶ Bring down the PHY link, and stop checking the status
Parameters
struct phy_device * phydev- target phy_device struct
-
void
phy_start(struct phy_device * phydev)¶ start or restart a PHY device
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Indicates the attached device’s readiness to
- handle PHY-related work. Used during startup to start the
PHY, and after a call to
phy_stop()to resume operation. Also used to indicate the MDIO bus has cleared an error condition.
-
void
phy_mac_interrupt(struct phy_device * phydev)¶ MAC says the link has changed
Parameters
struct phy_device * phydev- phy_device struct with changed link
Description
The MAC layer is able to indicate there has been a change in the PHY link status. Trigger the state machine and work a work queue.
-
int
phy_init_eee(struct phy_device * phydev, bool clk_stop_enable)¶ init and check the EEE feature
Parameters
struct phy_device * phydev- target phy_device struct
bool clk_stop_enable- PHY may stop the clock during LPI
Description
it checks if the Energy-Efficient Ethernet (EEE) is supported by looking at the MMD registers 3.20 and 7.60/61 and it programs the MMD register 3.0 setting the “Clock stop enable” bit if required.
-
int
phy_get_eee_err(struct phy_device * phydev)¶ report the EEE wake error count
Parameters
struct phy_device * phydev- target phy_device struct
Description
it is to report the number of time where the PHY failed to complete its normal wake sequence.
-
int
phy_ethtool_get_eee(struct phy_device * phydev, struct ethtool_eee * data)¶ get EEE supported and status
Parameters
struct phy_device * phydev- target phy_device struct
struct ethtool_eee * data- ethtool_eee data
Description
it reportes the Supported/Advertisement/LP Advertisement capabilities.
-
int
phy_ethtool_set_eee(struct phy_device * phydev, struct ethtool_eee * data)¶ set EEE supported and status
Parameters
struct phy_device * phydev- target phy_device struct
struct ethtool_eee * data- ethtool_eee data
Description
it is to program the Advertisement EEE register.
-
int
phy_clear_interrupt(struct phy_device * phydev)¶ Ack the phy device’s interrupt
Parameters
struct phy_device * phydev- the phy_device struct
Description
If the phydev driver has an ack_interrupt function, call it to ack and clear the phy device’s interrupt.
Returns 0 on success or < 0 on error.
-
int
phy_config_interrupt(struct phy_device * phydev, bool interrupts)¶ configure the PHY device for the requested interrupts
Parameters
struct phy_device * phydev- the phy_device struct
bool interrupts- interrupt flags to configure for this phydev
Description
Returns 0 on success or < 0 on error.
-
const struct phy_setting *
phy_find_valid(int speed, int duplex, unsigned long * supported)¶ find a PHY setting that matches the requested parameters
Parameters
int speed- desired speed
int duplex- desired duplex
unsigned long * supported- mask of supported link modes
Description
Locate a supported phy setting that is, in priority order:
- an exact match for the specified speed and duplex mode
- a match for the specified speed, or slower speed
- the slowest supported speed
Returns the matched phy_setting entry, or NULL if no supported phy
settings were found.
-
unsigned int
phy_supported_speeds(struct phy_device * phy, unsigned int * speeds, unsigned int size)¶ return all speeds currently supported by a phy device
Parameters
struct phy_device * phy- The phy device to return supported speeds of.
unsigned int * speeds- buffer to store supported speeds in.
unsigned int size- size of speeds buffer.
Description
Returns the number of supported speeds, and fills the speeds buffer with the supported speeds. If speeds buffer is too small to contain all currently supported speeds, will return as many speeds as can fit.
-
bool
phy_check_valid(int speed, int duplex, unsigned long * features)¶ check if there is a valid PHY setting which matches speed, duplex, and feature mask
Parameters
int speed- speed to match
int duplex- duplex to match
unsigned long * features- A mask of the valid settings
Description
Returns true if there is a valid setting, false otherwise.
-
void
phy_sanitize_settings(struct phy_device * phydev)¶ make sure the PHY is set to supported speed and duplex
Parameters
struct phy_device * phydev- the target phy_device struct
Description
- Make sure the PHY is set to supported speeds and
- duplexes. Drop down by one in this order: 1000/FULL, 1000/HALF, 100/FULL, 100/HALF, 10/FULL, 10/HALF.
-
int
phy_check_link_status(struct phy_device * phydev)¶ check link status and set state accordingly
Parameters
struct phy_device * phydev- the phy_device struct
Description
Check for link and whether autoneg was triggered / is running and set state accordingly
-
void
phy_stop_machine(struct phy_device * phydev)¶ stop the PHY state machine tracking
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Stops the state machine delayed workqueue, sets the
- state to UP (unless it wasn’t up yet). This function must be called BEFORE phy_detach.
-
void
phy_error(struct phy_device * phydev)¶ enter HALTED state for this PHY device
Parameters
struct phy_device * phydev- target phy_device struct
Description
Moves the PHY to the HALTED state in response to a read or write error, and tells the controller the link is down. Must not be called from interrupt context, or while the phydev->lock is held.
-
int
phy_disable_interrupts(struct phy_device * phydev)¶ Disable the PHY interrupts from the PHY side
Parameters
struct phy_device * phydev- target phy_device struct
-
irqreturn_t
phy_interrupt(int irq, void * phy_dat)¶ PHY interrupt handler
Parameters
int irq- interrupt line
void * phy_dat- phy_device pointer
Description
Handle PHY interrupt
-
int
phy_enable_interrupts(struct phy_device * phydev)¶ Enable the interrupts from the PHY side
Parameters
struct phy_device * phydev- target phy_device struct
-
void
phy_state_machine(struct work_struct * work)¶ Handle the state machine
Parameters
struct work_struct * work- work_struct that describes the work to be done
-
int
phy_register_fixup(const char * bus_id, u32 phy_uid, u32 phy_uid_mask, int (*run) (struct phy_device *)¶ creates a new phy_fixup and adds it to the list
Parameters
const char * bus_id- A string which matches phydev->mdio.dev.bus_id (or PHY_ANY_ID)
u32 phy_uid- Used to match against phydev->phy_id (the UID of the PHY) It can also be PHY_ANY_UID
u32 phy_uid_mask- Applied to phydev->phy_id and fixup->phy_uid before comparison
int (*)(struct phy_device *) run- The actual code to be run when a matching PHY is found
-
int
phy_unregister_fixup(const char * bus_id, u32 phy_uid, u32 phy_uid_mask)¶ remove a phy_fixup from the list
Parameters
const char * bus_id- A string matches fixup->bus_id (or PHY_ANY_ID) in phy_fixup_list
u32 phy_uid- A phy id matches fixup->phy_id (or PHY_ANY_UID) in phy_fixup_list
u32 phy_uid_mask- Applied to phy_uid and fixup->phy_uid before comparison
-
struct phy_device *
get_phy_device(struct mii_bus * bus, int addr, bool is_c45)¶ reads the specified PHY device and returns its phy_device struct
Parameters
struct mii_bus * bus- the target MII bus
int addr- PHY address on the MII bus
bool is_c45- If true the PHY uses the 802.3 clause 45 protocol
Description
- Reads the ID registers of the PHY at addr on the
- bus, then allocates and returns the phy_device to represent it.
-
int
phy_device_register(struct phy_device * phydev)¶ Register the phy device on the MDIO bus
Parameters
struct phy_device * phydev- phy_device structure to be added to the MDIO bus
-
void
phy_device_remove(struct phy_device * phydev)¶ Remove a previously registered phy device from the MDIO bus
Parameters
struct phy_device * phydev- phy_device structure to remove
Description
This doesn’t free the phy_device itself, it merely reverses the effects
of phy_device_register(). Use phy_device_free() to free the device
after calling this function.
-
struct phy_device *
phy_find_first(struct mii_bus * bus)¶ finds the first PHY device on the bus
Parameters
struct mii_bus * bus- the target MII bus
-
int
phy_connect_direct(struct net_device * dev, struct phy_device * phydev, void (*handler) (struct net_device *, phy_interface_t interface)¶ connect an ethernet device to a specific phy_device
Parameters
struct net_device * dev- the network device to connect
struct phy_device * phydev- the pointer to the phy device
void (*)(struct net_device *) handler- callback function for state change notifications
phy_interface_t interface- PHY device’s interface
-
struct phy_device *
phy_connect(struct net_device * dev, const char * bus_id, void (*handler) (struct net_device *, phy_interface_t interface)¶ connect an ethernet device to a PHY device
Parameters
struct net_device * dev- the network device to connect
const char * bus_id- the id string of the PHY device to connect
void (*)(struct net_device *) handler- callback function for state change notifications
phy_interface_t interface- PHY device’s interface
Description
- Convenience function for connecting ethernet
- devices to PHY devices. The default behavior is for the PHY infrastructure to handle everything, and only notify the connected driver when the link status changes. If you don’t want, or can’t use the provided functionality, you may choose to call only the subset of functions which provide the desired functionality.
-
void
phy_disconnect(struct phy_device * phydev)¶ disable interrupts, stop state machine, and detach a PHY device
Parameters
struct phy_device * phydev- target phy_device struct
-
int
phy_attach_direct(struct net_device * dev, struct phy_device * phydev, u32 flags, phy_interface_t interface)¶ attach a network device to a given PHY device pointer
Parameters
struct net_device * dev- network device to attach
struct phy_device * phydev- Pointer to phy_device to attach
u32 flags- PHY device’s dev_flags
phy_interface_t interface- PHY device’s interface
Description
- Called by drivers to attach to a particular PHY
- device. The phy_device is found, and properly hooked up to the phy_driver. If no driver is attached, then a generic driver is used. The phy_device is given a ptr to the attaching device, and given a callback for link status change. The phy_device is returned to the attaching driver. This function takes a reference on the phy device.
-
struct phy_device *
phy_attach(struct net_device * dev, const char * bus_id, phy_interface_t interface)¶ attach a network device to a particular PHY device
Parameters
struct net_device * dev- network device to attach
const char * bus_id- Bus ID of PHY device to attach
phy_interface_t interface- PHY device’s interface
Description
- Same as phy_attach_direct() except that a PHY bus_id
- string is passed instead of a pointer to a struct phy_device.
-
void
phy_detach(struct phy_device * phydev)¶ detach a PHY device from its network device
Parameters
struct phy_device * phydev- target phy_device struct
Description
This detaches the phy device from its network device and the phy
driver, and drops the reference count taken in phy_attach_direct().
-
int
phy_reset_after_clk_enable(struct phy_device * phydev)¶ perform a PHY reset if needed
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Some PHYs are known to need a reset after their refclk was
- enabled. This function evaluates the flags and perform the reset if it’s needed. Returns < 0 on error, 0 if the phy wasn’t reset and 1 if the phy was reset.
-
int
genphy_config_eee_advert(struct phy_device * phydev)¶ disable unwanted eee mode advertisement
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Writes MDIO_AN_EEE_ADV after disabling unsupported energy
- efficent ethernet modes. Returns 0 if the PHY’s advertisement hasn’t changed, and 1 if it has changed.
-
int
genphy_setup_forced(struct phy_device * phydev)¶ configures/forces speed/duplex from phydev
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Configures MII_BMCR to force speed/duplex
- to the values in phydev. Assumes that the values are valid.
Please see
phy_sanitize_settings().
-
int
genphy_restart_aneg(struct phy_device * phydev)¶ Enable and Restart Autonegotiation
Parameters
struct phy_device * phydev- target phy_device struct
-
int
genphy_config_aneg(struct phy_device * phydev)¶ restart auto-negotiation or write BMCR
Parameters
struct phy_device * phydev- target phy_device struct
Description
- If auto-negotiation is enabled, we configure the
- advertising, and then restart auto-negotiation. If it is not enabled, then we write the BMCR.
-
int
genphy_aneg_done(struct phy_device * phydev)¶ return auto-negotiation status
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Reads the status register and returns 0 either if
- auto-negotiation is incomplete, or if there was an error. Returns BMSR_ANEGCOMPLETE if auto-negotiation is done.
-
int
genphy_update_link(struct phy_device * phydev)¶ update link status in phydev
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Update the value in phydev->link to reflect the
- current link value. In order to do this, we need to read the status register twice, keeping the second value.
-
int
genphy_read_status(struct phy_device * phydev)¶ check the link status and update current link state
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Check the link, then figure out the current state
- by comparing what we advertise with what the link partner advertises. Start by checking the gigabit possibilities, then move on to 10/100.
-
int
genphy_soft_reset(struct phy_device * phydev)¶ software reset the PHY via BMCR_RESET bit
Parameters
struct phy_device * phydev- target phy_device struct
Description
Perform a software PHY reset using the standard BMCR_RESET bit and poll for the reset bit to be cleared.
Return
0 on success, < 0 on failure
-
int
genphy_read_abilities(struct phy_device * phydev)¶ read PHY abilities from Clause 22 registers
Parameters
struct phy_device * phydev- target phy_device struct
Description
Reads the PHY’s abilities and populates phydev->supported accordingly.
Return
0 on success, < 0 on failure
-
void
phy_remove_link_mode(struct phy_device * phydev, u32 link_mode)¶ Remove a supported link mode
Parameters
struct phy_device * phydev- phy_device structure to remove link mode from
u32 link_mode- Link mode to be removed
Description
Some MACs don’t support all link modes which the PHY does. e.g. a 1G MAC often does not support 1000Half. Add a helper to remove a link mode.
-
void
phy_advertise_supported(struct phy_device * phydev)¶ Advertise all supported modes
Parameters
struct phy_device * phydev- target phy_device struct
Description
Called to advertise all supported modes, doesn’t touch pause mode advertising.
-
void
phy_support_sym_pause(struct phy_device * phydev)¶ Enable support of symmetrical pause
Parameters
struct phy_device * phydev- target phy_device struct
Description
Called by the MAC to indicate is supports symmetrical Pause, but not asym pause.
-
void
phy_support_asym_pause(struct phy_device * phydev)¶ Enable support of asym pause
Parameters
struct phy_device * phydev- target phy_device struct
Description
Called by the MAC to indicate is supports Asym Pause.
-
void
phy_set_sym_pause(struct phy_device * phydev, bool rx, bool tx, bool autoneg)¶ Configure symmetric Pause
Parameters
struct phy_device * phydev- target phy_device struct
bool rx- Receiver Pause is supported
bool tx- Transmit Pause is supported
bool autoneg- Auto neg should be used
Description
Configure advertised Pause support depending on if receiver pause and pause auto neg is supported. Generally called from the set_pauseparam .ndo.
-
void
phy_set_asym_pause(struct phy_device * phydev, bool rx, bool tx)¶ Configure Pause and Asym Pause
Parameters
struct phy_device * phydev- target phy_device struct
bool rx- Receiver Pause is supported
bool tx- Transmit Pause is supported
Description
Configure advertised Pause support depending on if transmit and receiver pause is supported. If there has been a change in adverting, trigger a new autoneg. Generally called from the set_pauseparam .ndo.
-
bool
phy_validate_pause(struct phy_device * phydev, struct ethtool_pauseparam * pp)¶ Test if the PHY/MAC support the pause configuration
Parameters
struct phy_device * phydev- phy_device struct
struct ethtool_pauseparam * pp- requested pause configuration
Description
Test if the PHY/MAC combination supports the Pause configuration the user is requesting. Returns True if it is supported, false otherwise.
-
int
phy_driver_register(struct phy_driver * new_driver, struct module * owner)¶ register a phy_driver with the PHY layer
Parameters
struct phy_driver * new_driver- new phy_driver to register
struct module * owner- module owning this PHY
-
int
get_phy_c45_ids(struct mii_bus * bus, int addr, u32 * phy_id, struct phy_c45_device_ids * c45_ids)¶ reads the specified addr for its 802.3-c45 IDs.
Parameters
struct mii_bus * bus- the target MII bus
int addr- PHY address on the MII bus
u32 * phy_id- where to store the ID retrieved.
struct phy_c45_device_ids * c45_ids- where to store the c45 ID information.
Description
If the PHY devices-in-package appears to be valid, it and the corresponding identifiers are stored in c45_ids, zero is stored in phy_id. Otherwise 0xffffffff is stored in phy_id. Returns zero on success.
-
int
get_phy_id(struct mii_bus * bus, int addr, u32 * phy_id, bool is_c45, struct phy_c45_device_ids * c45_ids)¶ reads the specified addr for its ID.
Parameters
struct mii_bus * bus- the target MII bus
int addr- PHY address on the MII bus
u32 * phy_id- where to store the ID retrieved.
bool is_c45- If true the PHY uses the 802.3 clause 45 protocol
struct phy_c45_device_ids * c45_ids- where to store the c45 ID information.
Description
- In the case of a 802.3-c22 PHY, reads the ID registers
of the PHY at addr on the bus, stores it in phy_id and returns zero on success.
In the case of a 802.3-c45 PHY,
get_phy_c45_ids()is invoked, and its return value is in turn returned.
-
void
phy_prepare_link(struct phy_device * phydev, void (*handler) (struct net_device *)¶ prepares the PHY layer to monitor link status
Parameters
struct phy_device * phydev- target phy_device struct
void (*)(struct net_device *) handler- callback function for link status change notifications
Description
- Tells the PHY infrastructure to handle the
- gory details on monitoring link status (whether through polling or an interrupt), and to call back to the connected device driver when the link status changes. If you want to monitor your own link state, don’t call this function.
-
int
phy_poll_reset(struct phy_device * phydev)¶ Safely wait until a PHY reset has properly completed
Parameters
struct phy_device * phydev- The PHY device to poll
Description
- According to IEEE 802.3, Section 2, Subsection 22.2.4.1.1, as
published in 2008, a PHY reset may take up to 0.5 seconds. The MII BMCR register must be polled until the BMCR_RESET bit clears.
Furthermore, any attempts to write to PHY registers may have no effect or even generate MDIO bus errors until this is complete.
Some PHYs (such as the Marvell 88E1111) don’t entirely conform to the standard and do not fully reset after the BMCR_RESET bit is set, and may even REQUIRE a soft-reset to properly restart autonegotiation. In an effort to support such broken PHYs, this function is separate from the standard phy_init_hw() which will zero all the other bits in the BMCR and reapply all driver-specific and board-specific fixups.
-
int
genphy_config_advert(struct phy_device * phydev)¶ sanitize and advertise auto-negotiation parameters
Parameters
struct phy_device * phydev- target phy_device struct
Description
- Writes MII_ADVERTISE with the appropriate values,
- after sanitizing the values to make sure we only advertise what is supported. Returns < 0 on error, 0 if the PHY’s advertisement hasn’t changed, and > 0 if it has changed.
Parameters
struct device * dev- device to probe and init
Description
- Take care of setting up the phy_device structure,
- set the state to READY (the driver’s init function should set it to STARTING if needed).
-
struct mii_bus *
mdiobus_alloc_size(size_t size)¶ allocate a mii_bus structure
Parameters
size_t size- extra amount of memory to allocate for private storage. If non-zero, then bus->priv is points to that memory.
Description
called by a bus driver to allocate an mii_bus structure to fill in.
-
struct mii_bus *
devm_mdiobus_alloc_size(struct device * dev, int sizeof_priv)¶ Resource-managed
mdiobus_alloc_size()
Parameters
struct device * dev- Device to allocate mii_bus for
int sizeof_priv- Space to allocate for private structure.
Description
Managed mdiobus_alloc_size. mii_bus allocated with this function is automatically freed on driver detach.
If an mii_bus allocated with this function needs to be freed separately,
devm_mdiobus_free() must be used.
Return
Pointer to allocated mii_bus on success, NULL on failure.
-
void
devm_mdiobus_free(struct device * dev, struct mii_bus * bus)¶ Resource-managed
mdiobus_free()
Parameters
struct device * dev- Device this mii_bus belongs to
struct mii_bus * bus- the mii_bus associated with the device
Description
Free mii_bus allocated with devm_mdiobus_alloc_size().
-
struct mii_bus *
of_mdio_find_bus(struct device_node * mdio_bus_np)¶ Given an mii_bus node, find the mii_bus.
Parameters
struct device_node * mdio_bus_np- Pointer to the mii_bus.
Description
Returns a reference to the mii_bus, or NULL if none found. The embedded struct device will have its reference count incremented, and this must be put once the bus is finished with.
Because the association of a device_node and mii_bus is made via of_mdiobus_register(), the mii_bus cannot be found before it is registered with of_mdiobus_register().
-
int
__mdiobus_register(struct mii_bus * bus, struct module * owner)¶ bring up all the PHYs on a given bus and attach them to bus
Parameters
struct mii_bus * bus- target mii_bus
struct module * owner- module containing bus accessor functions
Description
- Called by a bus driver to bring up all the PHYs
- on a given bus, and attach them to the bus. Drivers should use
mdiobus_register() rather than
__mdiobus_register()unless they need to pass a specific owner module. MDIO devices which are not PHYs will not be brought up by this function. They are expected to to be explicitly listed in DT and instantiated by of_mdiobus_register().
Returns 0 on success or < 0 on error.
-
void
mdiobus_free(struct mii_bus * bus)¶ free a struct mii_bus
Parameters
struct mii_bus * bus- mii_bus to free
Description
This function releases the reference to the underlying device object in the mii_bus. If this is the last reference, the mii_bus will be freed.
-
struct phy_device *
mdiobus_scan(struct mii_bus * bus, int addr)¶ scan a bus for MDIO devices.
Parameters
struct mii_bus * bus- mii_bus to scan
int addr- address on bus to scan
Description
This function scans the MDIO bus, looking for devices which can be identified using a vendor/product ID in registers 2 and 3. Not all MDIO devices have such registers, but PHY devices typically do. Hence this function assumes anything found is a PHY, or can be treated as a PHY. Other MDIO devices, such as switches, will probably not be found during the scan.
-
int
__mdiobus_read(struct mii_bus * bus, int addr, u32 regnum)¶ Unlocked version of the mdiobus_read function
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to read
Description
Read a MDIO bus register. Caller must hold the mdio bus lock.
NOTE
MUST NOT be called from interrupt context.
-
int
__mdiobus_write(struct mii_bus * bus, int addr, u32 regnum, u16 val)¶ Unlocked version of the mdiobus_write function
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to write
u16 val- value to write to regnum
Description
Write a MDIO bus register. Caller must hold the mdio bus lock.
NOTE
MUST NOT be called from interrupt context.
-
int
mdiobus_read_nested(struct mii_bus * bus, int addr, u32 regnum)¶ Nested version of the mdiobus_read function
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to read
Description
In case of nested MDIO bus access avoid lockdep false positives by using mutex_lock_nested().
NOTE
MUST NOT be called from interrupt context, because the bus read/write functions may wait for an interrupt to conclude the operation.
-
int
mdiobus_read(struct mii_bus * bus, int addr, u32 regnum)¶ Convenience function for reading a given MII mgmt register
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to read
NOTE
MUST NOT be called from interrupt context, because the bus read/write functions may wait for an interrupt to conclude the operation.
-
int
mdiobus_write_nested(struct mii_bus * bus, int addr, u32 regnum, u16 val)¶ Nested version of the mdiobus_write function
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to write
u16 val- value to write to regnum
Description
In case of nested MDIO bus access avoid lockdep false positives by using mutex_lock_nested().
NOTE
MUST NOT be called from interrupt context, because the bus read/write functions may wait for an interrupt to conclude the operation.
-
int
mdiobus_write(struct mii_bus * bus, int addr, u32 regnum, u16 val)¶ Convenience function for writing a given MII mgmt register
Parameters
struct mii_bus * bus- the mii_bus struct
int addr- the phy address
u32 regnum- register number to write
u16 val- value to write to regnum
NOTE
MUST NOT be called from interrupt context, because the bus read/write functions may wait for an interrupt to conclude the operation.
Parameters
struct device * d- the target struct device that contains the mii_bus
Description
called when the last reference to an mii_bus is dropped, to free the underlying memory.
-
int
mdiobus_create_device(struct mii_bus * bus, struct mdio_board_info * bi)¶ create a full MDIO device given a mdio_board_info structure
Parameters
struct mii_bus * bus- MDIO bus to create the devices on
struct mdio_board_info * bi- mdio_board_info structure describing the devices
Description
Returns 0 on success or < 0 on error.
-
int
mdio_bus_match(struct device * dev, struct device_driver * drv)¶ determine if given MDIO driver supports the given MDIO device
Parameters
struct device * dev- target MDIO device
struct device_driver * drv- given MDIO driver
Description
- Given a MDIO device, and a MDIO driver, return 1 if
- the driver supports the device. Otherwise, return 0. This may require calling the devices own match function, since different classes of MDIO devices have different match criteria.
PHYLINK¶
PHYLINK interfaces traditional network drivers with PHYLIB, fixed-links, and SFF modules (eg, hot-pluggable SFP) that may contain PHYs. PHYLINK provides management of the link state and link modes.
-
struct
phylink_link_state¶ link state structure
Definition
struct phylink_link_state {
__ETHTOOL_DECLARE_LINK_MODE_MASK(advertising);
__ETHTOOL_DECLARE_LINK_MODE_MASK(lp_advertising);
phy_interface_t interface;
int speed;
int duplex;
int pause;
unsigned int link:1;
unsigned int an_enabled:1;
unsigned int an_complete:1;
};
Members
interface- link
typedef phy_interface_tmode speed- link speed, one of the SPEED_* constants.
duplex- link duplex mode, one of DUPLEX_* constants.
pause- link pause state, described by MLO_PAUSE_* constants.
link- true if the link is up.
an_enabled- true if autonegotiation is enabled/desired.
an_complete- true if autonegotiation has completed.
-
struct
phylink_config¶ PHYLINK configuration structure
Definition
struct phylink_config {
struct device *dev;
enum phylink_op_type type;
};
Members
dev- a pointer to a struct device associated with the MAC
type- operation type of PHYLINK instance
-
struct
phylink_mac_ops¶ MAC operations structure.
Definition
struct phylink_mac_ops {
void (*validate)(struct phylink_config *config,unsigned long *supported, struct phylink_link_state *state);
int (*mac_link_state)(struct phylink_config *config, struct phylink_link_state *state);
void (*mac_config)(struct phylink_config *config, unsigned int mode, const struct phylink_link_state *state);
void (*mac_an_restart)(struct phylink_config *config);
void (*mac_link_down)(struct phylink_config *config, unsigned int mode, phy_interface_t interface);
void (*mac_link_up)(struct phylink_config *config, unsigned int mode,phy_interface_t interface, struct phy_device *phy);
};
Members
validate- Validate and update the link configuration.
mac_link_state- Read the current link state from the hardware.
mac_config- configure the MAC for the selected mode and state.
mac_an_restart- restart 802.3z BaseX autonegotiation.
mac_link_down- take the link down.
mac_link_up- allow the link to come up.
Description
The individual methods are described more fully below.
-
void
validate(struct phylink_config * config, unsigned long * supported, struct phylink_link_state * state)¶ Validate and update the link configuration
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config. unsigned long * supported- ethtool bitmask for supported link modes.
struct phylink_link_state * state- a pointer to a
struct phylink_link_state.
Description
Clear bits in the supported and state->advertising masks that are not supportable by the MAC.
Note that the PHY may be able to transform from one connection
technology to another, so, eg, don’t clear 1000BaseX just
because the MAC is unable to BaseX mode. This is more about
clearing unsupported speeds and duplex settings. The port modes
should not be cleared; phylink_set_port_modes() will help with this.
If the state->interface mode is PHY_INTERFACE_MODE_1000BASEX
or PHY_INTERFACE_MODE_2500BASEX, select the appropriate mode
based on state->advertising and/or state->speed and update
state->interface accordingly. See phylink_helper_basex_speed().
When state->interface is PHY_INTERFACE_MODE_NA, phylink expects the
MAC driver to return all supported link modes.
If the state->interface mode is not supported, then the supported mask must be cleared.
-
int
mac_link_state(struct phylink_config * config, struct phylink_link_state * state)¶ Read the current link state from the hardware
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config. struct phylink_link_state * state- a pointer to a
struct phylink_link_state.
Description
Read the current link state from the MAC, reporting the current
speed in state->speed, duplex mode in state->duplex, pause mode
in state->pause using the MLO_PAUSE_RX and MLO_PAUSE_TX bits,
negotiation completion state in state->an_complete, and link
up state in state->link.
-
void
mac_config(struct phylink_config * config, unsigned int mode, const struct phylink_link_state * state)¶ configure the MAC for the selected mode and state
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config. unsigned int mode- one of
MLO_AN_FIXED,MLO_AN_PHY,MLO_AN_INBAND. const struct phylink_link_state * state- a pointer to a
struct phylink_link_state.
Description
Note - not all members of state are valid. In particular,
state->lp_advertising, state->link, state->an_complete are never
guaranteed to be correct, and so any mac_config() implementation must
never reference these fields.
The action performed depends on the currently selected mode:
MLO_AN_FIXED,MLO_AN_PHY:Configure the specified state->speed, state->duplex and state->pause (
MLO_PAUSE_TX/MLO_PAUSE_RX) modes over a link specified by state->interface. state->advertising may be used, but is not required. Other members of state must be ignored.Valid state members: interface, speed, duplex, pause, advertising.
MLO_AN_INBAND:place the link in an inband negotiation mode (such as 802.3z 1000base-X or Cisco SGMII mode depending on the state->interface mode). In both cases, link state management (whether the link is up or not) is performed by the MAC, and reported via the
mac_link_state()callback. Changes in link state must be made by callingphylink_mac_change().If in 802.3z mode, the link speed is fixed, dependent on the state->interface. Duplex is negotiated, and pause is advertised according to state->an_enabled, state->pause and state->advertising flags. Beware of MACs which only support full duplex at gigabit and higher speeds.
If in Cisco SGMII mode, the link speed and duplex mode are passed in the serial bitstream 16-bit configuration word, and the MAC should be configured to read these bits and acknowledge the configuration word. Nothing is advertised by the MAC. The MAC is responsible for reading the configuration word and configuring itself accordingly.
Valid state members: interface, an_enabled, pause, advertising.
Implementations are expected to update the MAC to reflect the requested settings - i.o.w., if nothing has changed between two calls, no action is expected. If only flow control settings have changed, flow control should be updated without taking the link down. This “update” behaviour is critical to avoid bouncing the link up status.
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void
mac_an_restart(struct phylink_config * config)¶ restart 802.3z BaseX autonegotiation
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config.
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void
mac_link_down(struct phylink_config * config, unsigned int mode, phy_interface_t interface)¶ take the link down
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config. unsigned int mode- link autonegotiation mode
phy_interface_t interface- link
typedef phy_interface_tmode
Description
If mode is not an in-band negotiation mode (as defined by
phylink_autoneg_inband()), force the link down and disable any
Energy Efficient Ethernet MAC configuration. Interface type
selection must be done in mac_config().
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void
mac_link_up(struct phylink_config * config, unsigned int mode, phy_interface_t interface, struct phy_device * phy)¶ allow the link to come up
Parameters
struct phylink_config * config- a pointer to a
struct phylink_config. unsigned int mode- link autonegotiation mode
phy_interface_t interface- link
typedef phy_interface_tmode struct phy_device * phy- any attached phy
Description
If mode is not an in-band negotiation mode (as defined by
phylink_autoneg_inband()), allow the link to come up. If phy
is non-NULL, configure Energy Efficient Ethernet by calling
phy_init_eee() and perform appropriate MAC configuration for EEE.
Interface type selection must be done in mac_config().
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struct
phylink¶ internal data type for phylink
Definition
struct phylink {
};
Members
-
void
phylink_set_port_modes(unsigned long * mask)¶ set the port type modes in the ethtool mask
Parameters
unsigned long * mask- ethtool link mode mask
Description
Sets all the port type modes in the ethtool mask. MAC drivers should use this in their ‘validate’ callback.
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struct phylink *
phylink_create(struct phylink_config * config, struct fwnode_handle * fwnode, phy_interface_t iface, const struct phylink_mac_ops * ops)¶ create a phylink instance
Parameters
struct phylink_config * config- undescribed
struct fwnode_handle * fwnode- a pointer to a
struct fwnode_handledescribing the network interface phy_interface_t iface- the desired link mode defined by
typedef phy_interface_t const struct phylink_mac_ops * ops- a pointer to a
struct phylink_mac_opsfor the MAC.
Description
Create a new phylink instance, and parse the link parameters found in np. This will parse in-band modes, fixed-link or SFP configuration.
Returns a pointer to a struct phylink, or an error-pointer value. Users
must use IS_ERR() to check for errors from this function.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create()
Description
Destroy a phylink instance. Any PHY that has been attached must have been
cleaned up via phylink_disconnect_phy() prior to calling this function.
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int
phylink_connect_phy(struct phylink * pl, struct phy_device * phy)¶ connect a PHY to the phylink instance
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct phy_device * phy- a pointer to a
struct phy_device.
Description
Connect phy to the phylink instance specified by pl by calling
phy_attach_direct(). Configure the phy according to the MAC driver’s
capabilities, start the PHYLIB state machine and enable any interrupts
that the PHY supports.
This updates the phylink’s ethtool supported and advertising link mode masks.
Returns 0 on success or a negative errno.
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int
phylink_of_phy_connect(struct phylink * pl, struct device_node * dn, u32 flags)¶ connect the PHY specified in the DT mode.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct device_node * dn- a pointer to a
struct device_node. u32 flags- PHY-specific flags to communicate to the PHY device driver
Description
Connect the phy specified in the device node dn to the phylink instance
specified by pl. Actions specified in phylink_connect_phy() will be
performed.
Returns 0 on success or a negative errno.
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void
phylink_disconnect_phy(struct phylink * pl)¶ disconnect any PHY attached to the phylink instance.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create()
Description
Disconnect any current PHY from the phylink instance described by pl.
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int
phylink_fixed_state_cb(struct phylink * pl, void (*cb) (struct net_device *dev, struct phylink_link_state *state)¶ allow setting a fixed link callback
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() void (*)(struct net_device *dev, struct phylink_link_state *state) cb- callback to execute to determine the fixed link state.
Description
The MAC driver should call this driver when the state of its link can be determined through e.g: an out of band MMIO register.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() bool up- indicates whether the link is currently up.
Description
The MAC driver should call this driver when the state of its link changes (eg, link failure, new negotiation results, etc.)
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create()
Description
Start the phylink instance specified by pl, configuring the MAC for the
desired link mode(s) and negotiation style. This should be called from the
network device driver’s struct net_device_ops ndo_open() method.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create()
Description
Stop the phylink instance specified by pl. This should be called from the
network device driver’s struct net_device_ops ndo_stop() method. The
network device’s carrier state should not be changed prior to calling this
function.
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void
phylink_ethtool_get_wol(struct phylink * pl, struct ethtool_wolinfo * wol)¶ get the wake on lan parameters for the PHY
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_wolinfo * wol- a pointer to
struct ethtool_wolinfoto hold the read parameters
Description
Read the wake on lan parameters from the PHY attached to the phylink instance specified by pl. If no PHY is currently attached, report no support for wake on lan.
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int
phylink_ethtool_set_wol(struct phylink * pl, struct ethtool_wolinfo * wol)¶ set wake on lan parameters
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_wolinfo * wol- a pointer to
struct ethtool_wolinfofor the desired parameters
Description
Set the wake on lan parameters for the PHY attached to the phylink
instance specified by pl. If no PHY is attached, returns EOPNOTSUPP
error.
Returns zero on success or negative errno code.
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int
phylink_ethtool_ksettings_get(struct phylink * pl, struct ethtool_link_ksettings * kset)¶ get the current link settings
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_link_ksettings * kset- a pointer to a
struct ethtool_link_ksettingsto hold link settings
Description
Read the current link settings for the phylink instance specified by pl. This will be the link settings read from the MAC, PHY or fixed link settings depending on the current negotiation mode.
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int
phylink_ethtool_ksettings_set(struct phylink * pl, const struct ethtool_link_ksettings * kset)¶ set the link settings
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() const struct ethtool_link_ksettings * kset- a pointer to a
struct ethtool_link_ksettingsfor the desired modes
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create()
Description
Restart negotiation for the phylink instance specified by pl. This will cause any attached phy to restart negotiation with the link partner, and if the MAC is in a BaseX mode, the MAC will also be requested to restart negotiation.
Returns zero on success, or negative error code.
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void
phylink_ethtool_get_pauseparam(struct phylink * pl, struct ethtool_pauseparam * pause)¶ get the current pause parameters
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_pauseparam * pause- a pointer to a
struct ethtool_pauseparam
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int
phylink_ethtool_set_pauseparam(struct phylink * pl, struct ethtool_pauseparam * pause)¶ set the current pause parameters
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_pauseparam * pause- a pointer to a
struct ethtool_pauseparam
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create().
Description
Read the Energy Efficient Ethernet error counter from the PHY associated with the phylink instance specified by pl.
Returns positive error counter value, or negative error code.
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() bool clk_stop_enable- allow PHY to stop receive clock
Description
Must be called either with RTNL held or within mac_link_up()
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int
phylink_ethtool_get_eee(struct phylink * pl, struct ethtool_eee * eee)¶ read the energy efficient ethernet parameters
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_eee * eee- a pointer to a
struct ethtool_eeefor the read parameters
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int
phylink_ethtool_set_eee(struct phylink * pl, struct ethtool_eee * eee)¶ set the energy efficient ethernet parameters
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ethtool_eee * eee- a pointer to a
struct ethtool_eeefor the desired parameters
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int
phylink_mii_ioctl(struct phylink * pl, struct ifreq * ifr, int cmd)¶ generic mii ioctl interface
Parameters
struct phylink * pl- a pointer to a
struct phylinkreturned fromphylink_create() struct ifreq * ifr- a pointer to a
struct ifreqfor socket ioctls int cmd- ioctl cmd to execute
Description
Perform the specified MII ioctl on the PHY attached to the phylink instance specified by pl. If no PHY is attached, emulate the presence of the PHY.
Return
zero on success or negative error code.
SIOCGMIIPHY:- read register from the current PHY.
SIOCGMIIREG:- read register from the specified PHY.
SIOCSMIIREG:- set a register on the specified PHY.
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void
phylink_helper_basex_speed(struct phylink_link_state * state)¶ 1000BaseX/2500BaseX helper
Parameters
struct phylink_link_state * state- a pointer to a
struct phylink_link_state
Description
Inspect the interface mode, advertising mask or forced speed and decide whether to run at 2.5Gbit or 1Gbit appropriately, switching the interface mode to suit. state->interface is appropriately updated, and the advertising mask has the “other” baseX_Full flag cleared.
SFP support¶
-
struct
sfp_bus¶ internal representation of a sfp bus
Definition
struct sfp_bus {
};
Members
-
struct
sfp_eeprom_id¶ raw SFP module identification information
Definition
struct sfp_eeprom_id {
struct sfp_eeprom_base base;
struct sfp_eeprom_ext ext;
};
Members
base- base SFP module identification structure
ext- extended SFP module identification structure
Description
See the SFF-8472 specification and related documents for the definition of these structure members. This can be obtained from https://www.snia.org/technology-communities/sff/specifications
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struct
sfp_upstream_ops¶ upstream operations structure
Definition
struct sfp_upstream_ops {
void (*attach)(void *priv, struct sfp_bus *bus);
void (*detach)(void *priv, struct sfp_bus *bus);
int (*module_insert)(void *priv, const struct sfp_eeprom_id *id);
void (*module_remove)(void *priv);
void (*link_down)(void *priv);
void (*link_up)(void *priv);
int (*connect_phy)(void *priv, struct phy_device *);
void (*disconnect_phy)(void *priv);
};
Members
attach- called when the sfp socket driver is bound to the upstream (mandatory).
detach- called when the sfp socket driver is unbound from the upstream (mandatory).
module_insert- called after a module has been detected to determine whether the module is supported for the upstream device.
module_remove- called after the module has been removed.
link_down- called when the link is non-operational for whatever reason.
link_up- called when the link is operational.
connect_phy- called when an I2C accessible PHY has been detected on the module.
disconnect_phy- called when a module with an I2C accessible PHY has been removed.
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int
sfp_parse_port(struct sfp_bus * bus, const struct sfp_eeprom_id * id, unsigned long * support)¶ Parse the EEPROM base ID, setting the port type
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module const struct sfp_eeprom_id * id- a pointer to the module’s
struct sfp_eeprom_id unsigned long * support- optional pointer to an array of unsigned long for the ethtool support mask
Description
Parse the EEPROM identification given in id, and return one of
PORT_TP, PORT_FIBRE or PORT_OTHER. If support is non-NULL,
also set the ethtool ETHTOOL_LINK_MODE_xxx_BIT corresponding with
the connector type.
If the port type is not known, returns PORT_OTHER.
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void
sfp_parse_support(struct sfp_bus * bus, const struct sfp_eeprom_id * id, unsigned long * support)¶ Parse the eeprom id for supported link modes
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module const struct sfp_eeprom_id * id- a pointer to the module’s
struct sfp_eeprom_id unsigned long * support- pointer to an array of unsigned long for the ethtool support mask
Description
Parse the EEPROM identification information and derive the supported ethtool link modes for the module.
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phy_interface_t
sfp_select_interface(struct sfp_bus * bus, const struct sfp_eeprom_id * id, unsigned long * link_modes)¶ Select appropriate phy_interface_t mode
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module const struct sfp_eeprom_id * id- a pointer to the module’s
struct sfp_eeprom_id unsigned long * link_modes- ethtool link modes mask
Description
Derive the phy_interface_t mode for the information found in the module’s identifying EEPROM and the link modes mask. There is no standard or defined way to derive this information, so we decide based upon the link mode mask.
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int
sfp_get_module_info(struct sfp_bus * bus, struct ethtool_modinfo * modinfo)¶ Get the ethtool_modinfo for a SFP module
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module struct ethtool_modinfo * modinfo- a
struct ethtool_modinfo
Description
Fill in the type and eeprom_len parameters in modinfo for a module on the sfp bus specified by bus.
Returns 0 on success or a negative errno number.
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int
sfp_get_module_eeprom(struct sfp_bus * bus, struct ethtool_eeprom * ee, u8 * data)¶ Read the SFP module EEPROM
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module struct ethtool_eeprom * ee- a
struct ethtool_eeprom u8 * data- buffer to contain the EEPROM data (must be at least ee->len bytes)
Description
Read the EEPROM as specified by the supplied ee. See the documentation
for struct ethtool_eeprom for the region to be read.
Returns 0 on success or a negative errno number.
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module
Description
Inform the SFP socket that the network device is now up, so that the
module can be enabled by allowing TX_DISABLE to be deasserted. This
should be called from the network device driver’s struct net_device_ops
ndo_open() method.
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module
Description
Inform the SFP socket that the network device is now up, so that the
module can be disabled by asserting TX_DISABLE, disabling the laser
in optical modules. This should be called from the network device
driver’s struct net_device_ops ndo_stop() method.
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struct sfp_bus *
sfp_register_upstream(struct fwnode_handle * fwnode, void * upstream, const struct sfp_upstream_ops * ops)¶ Register the neighbouring device
Parameters
struct fwnode_handle * fwnode- firmware node for the SFP bus
void * upstream- the upstream private data
const struct sfp_upstream_ops * ops- the upstream’s
struct sfp_upstream_ops
Description
Register the upstream device (eg, PHY) with the SFP bus. MAC drivers
should use phylink, which will call this function for them. Returns
a pointer to the allocated struct sfp_bus.
On error, returns NULL.
Parameters
struct sfp_bus * bus- a pointer to the
struct sfp_busstructure for the sfp module
Description
Unregister a previously registered upstream connection for the SFP
module. bus is returned from sfp_register_upstream().