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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXAMPLES | NOTES | AUTHOR | SEE ALSO | COLOPHON |
seccomp_attr_set(3) libseccomp Documentation seccomp_attr_set(3)
seccomp_attr_set, seccomp_attr_get - Manage the seccomp filter
attributes
#include <seccomp.h>
typedef void * scmp_filter_ctx;
enum scmp_filter_attr;
int seccomp_attr_set(scmp_filter_ctx ctx,
enum scmp_filter_attr attr, uint32_t value);
int seccomp_attr_get(scmp_filter_ctx ctx,
enum scmp_filter_attr attr, uint32_t *value);
Link with -lseccomp.
The seccomp_attr_set() function sets the different seccomp filter
attributes while the seccomp_attr_get() function fetches the filter
attributes. The seccomp filter attributes are tunable values that
affect how the library behaves when generating and loading the
seccomp filter into the kernel. The attributes are reset to their
default values whenever the filter is initialized or reset via
seccomp_filter_init(3) or seccomp_filter_reset(3).
The filter context ctx is the value returned by the call to
seccomp_init(3).
Valid attr values are as follows:
SCMP_FLTATR_ACT_DEFAULT
The default filter action as specified in the call to
seccomp_filter_init(3) or seccomp_filter_reset(3). This
attribute is read-only.
SCMP_FLTATR_ACT_BADARCH
The filter action taken when the loaded filter does not match
the architecture of the executing application. Defaults to
the SCMP_ACT_KILL action.
SCMP_FLTATR_CTL_NNP
A flag to specify if the NO_NEW_PRIVS functionality should be
enabled before loading the seccomp filter into the kernel.
Setting this to off ( value == 0) results in no action,
meaning that loading the seccomp filter into the kernel will
fail if CAP_SYS_ADMIN is missing and NO_NEW_PRIVS has not been
externally set. Defaults to on ( value == 1).
SCMP_FLTATR_CTL_TSYNC
A flag to specify if the kernel should attempt to synchronize
the filters across all threads on seccomp_load(3). If the
kernel is unable to synchronize all of the thread then the
load operation will fail. This flag is only available on
Linux Kernel 3.17 or greater; attempting to enable this flag
on earlier kernels will result in an error being returned.
Defaults to off ( value == 0).
SCMP_FLTATR_ATL_TSKIP
A flag to specify if libseccomp should allow filter rules to
be created for the -1 syscall. The -1 syscall value can be
used by tracer programs to skip specific syscall invocations,
see seccomp(2) for more information. Defaults to off ( value
== 0).
Returns zero on success, negative errno values on failure.
#include <seccomp.h>
int main(int argc, char *argv[])
{
int rc = -1;
scmp_filter_ctx ctx;
ctx = seccomp_init(SCMP_ACT_ALLOW);
if (ctx == NULL)
goto out;
/* ... */
rc = seccomp_attr_set(ctx, SCMP_FLTATR_ACT_BADARCH, SCMP_ACT_TRAP);
if (rc < 0)
goto out;
/* ... */
out:
seccomp_release(ctx);
return -rc;
}
While the seccomp filter can be generated independent of the kernel,
kernel support is required to load and enforce the seccomp filter
generated by libseccomp.
The libseccomp project site, with more information and the source
code repository, can be found at
https://github.com/seccomp/libseccomp. This tool, as well as the
libseccomp library, is currently under development, please report any
bugs at the project site or directly to the author.
Paul Moore <paul@paul-moore.com>
seccomp_init(3), seccomp_reset(3), seccomp_load(3), seccomp(2)
This page is part of the libseccomp (high-level API to the Linux
Kernel's seccomp filter) project. Information about the project can
be found at ⟨https://github.com/seccomp/libseccomp⟩. If you have a
bug report for this manual page, see
⟨https://groups.google.com/d/forum/libseccomp⟩. This page was
obtained from the project's upstream Git repository
⟨https://github.com/seccomp/libseccomp⟩ on 2017-07-05. If you dis‐
cover any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
paul@paul-moore.com 21 August 2014 seccomp_attr_set(3)
Pages that refer to this page: seccomp_merge(3), seccomp_rule_add(3)