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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |
GETPEERNAME(2) Linux Programmer's Manual GETPEERNAME(2)
getpeername - get name of connected peer socket
#include <sys/socket.h>
int getpeername(int sockfd, struct sockaddr *addr, socklen_t
*addrlen);
getpeername() returns the address of the peer connected to the socket
sockfd, in the buffer pointed to by addr. The addrlen argument
should be initialized to indicate the amount of space pointed to by
addr. On return it contains the actual size of the name returned (in
bytes). The name is truncated if the buffer provided is too small.
The returned address is truncated if the buffer provided is too
small; in this case, addrlen will return a value greater than was
supplied to the call.
On success, zero is returned. On error, -1 is returned, and errno is
set appropriately.
EBADF The argument sockfd is not a valid file descriptor.
EFAULT The addr argument points to memory not in a valid part of the
process address space.
EINVAL addrlen is invalid (e.g., is negative).
ENOBUFS
Insufficient resources were available in the system to perform
the operation.
ENOTCONN
The socket is not connected.
ENOTSOCK
The file descriptor sockfd does not refer to a socket.
POSIX.1-2001, POSIX.1-2008, SVr4, 4.4BSD (getpeername() first
appeared in 4.2BSD).
For background on the socklen_t type, see accept(2).
For stream sockets, once a connect(2) has been performed, either
socket can call getpeername() to obtain the address of the peer
socket. On the other hand, datagram sockets are connectionless.
Calling connect(2) on a datagram socket merely sets the peer address
for outgoing datagrams sent with write(2) or recv(2). The caller of
connect(2) can use getpeername() to obtain the peer address that it
earlier set for the socket. However, the peer socket is unaware of
this information, and calling getpeername() on the peer socket will
return no useful information (unless a connect(2) call was also
executed on the peer). Note also that the receiver of a datagram can
obtain the address of the sender when using recvfrom(2).
accept(2), bind(2), getsockname(2), ip(7), socket(7), unix(7)
This page is part of release 4.12 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.
Linux 2016-12-12 GETPEERNAME(2)
Pages that refer to this page: socket(2), socketcall(2), syscalls(2), getnameinfo(3), signal-safety(7), socket(7), unix(7)