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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | EXAMPLES | NOTES | AUTHOR | SEE ALSO | COLOPHON |
seccomp_init(3) libseccomp Documentation seccomp_init(3)
seccomp_init, seccomp_reset - Initialize the seccomp filter state
#include <seccomp.h>
typedef void * scmp_filter_ctx;
scmp_filter_ctx seccomp_init(uint32_t def_action);
int seccomp_reset(scmp_filter_ctx ctx, uint32_t def_action);
Link with -lseccomp.
The seccomp_init() and seccomp_reset() functions (re)initialize the
internal seccomp filter state, prepares it for use, and sets the
default action based on the def_action parameter. The seccomp_init()
function must be called before any other libseccomp functions as the
rest of the library API will fail if the filter context is not
initialized properly. The seccomp_reset() function releases the
existing filter context state before reinitializing it and can only
be called after a call to seccomp_init() has succeeded.
When the caller is finished configuring the seccomp filter and has
loaded it into the kernel, the caller should call seccomp_release(3)
to release all of the filter context state.
Valid def_action values are as follows:
SCMP_ACT_KILL
The thread will be terminated by the kernel with SIGSYS when
it calls a syscall that does not match any of the configured
seccomp filter rules. The thread will not be able to catch
the signal.
SCMP_ACT_TRAP
The thread will be sent a SIGSYS signal when it calls a
syscall that does not match any of the configured seccomp
filter rules. It may catch this and change its behavior
accordingly. When using SA_SIGINFO with sigaction(2), si_code
will be set to SYS_SECCOMP, si_syscall will be set to the
syscall that failed the rules, and si_arch will be set to the
AUDIT_ARCH for the active ABI.
SCMP_ACT_ERRNO(uint16_t errno)
The thread will receive a return value of errno when it calls
a syscall that does not match any of the configured seccomp
filter rules.
SCMP_ACT_TRACE(uint16_t msg_num)
If the thread is being traced and the tracing process
specified the PTRACE_O_TRACESECCOMP option in the call to
ptrace(2), the tracing process will be notified, via
PTRACE_EVENT_SECCOMP, and the value provided in msg_num can be
retrieved using the PTRACE_GETEVENTMSG option.
SCMP_ACT_ALLOW
The seccomp filter will have no effect on the thread calling
the syscall if it does not match any of the configured seccomp
filter rules.
The seccomp_init() function returns a filter context on success, NULL
on failure. The seccomp_reset() function 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_KILL);
if (ctx == NULL)
goto out;
/* ... */
rc = seccomp_reset(ctx, SCMP_ACT_KILL);
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_release(3)
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 25 July 2012 seccomp_init(3)
Pages that refer to this page: seccomp(2), seccomp_arch_add(3), seccomp_attr_set(3), seccomp_export_bpf(3), seccomp_load(3), seccomp_merge(3), seccomp_release(3), seccomp_rule_add(3)