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.TH "seccomp_export_bpf" 3 "15 April 2012" "paul@paul-moore.com" "libseccomp Documentation"
.//////////////////////////////////////////////////////////////////////////////
.SH NAME
.//////////////////////////////////////////////////////////////////////////////
seccomp_export_bpf, seccomp_export_pfc \- Export the seccomp filter
.//////////////////////////////////////////////////////////////////////////////
.SH SYNOPSIS
.//////////////////////////////////////////////////////////////////////////////
.nf
.B #include <seccomp.h>
.sp
.BI "int seccomp_export_bpf(int " fd ");"
.BI "int seccomp_export_pfc(int " fd ");"
.fi
.//////////////////////////////////////////////////////////////////////////////
.SH DESCRIPTION
.//////////////////////////////////////////////////////////////////////////////
.P
The
.BR seccomp_export_bpf ()
and
.BR seccomp_export_pfc ()
functions generate and output the current seccomp filter in either BPF (Berkley
Packet Filter) or PFC (Pseudo Filter Code). The output of
.BR seccomp_export_bpf ()
is suitable for loading into the kernel, while the output of
.BR seccomp_export_pfc ()
is human readable and is intended primarily as a debugging tool for developers
using libseccomp. Both functions write the filter to the
.I fd
file descriptor.
.P
While the two output formats are guaranteed to be functionally equivalent for
the given seccomp filter configuration, the filter instructions, and their
ordering, are not guaranteed to be the same in both the BPF and PFC formats.
.//////////////////////////////////////////////////////////////////////////////
.SH RETURN VALUE
.//////////////////////////////////////////////////////////////////////////////
Returns zero on success, negative errno values on failure.
.//////////////////////////////////////////////////////////////////////////////
.SH EXAMPLES
.//////////////////////////////////////////////////////////////////////////////
.nf
#include <seccomp.h>
int main(int argc, char *argv[])
{
int rc;
int filter_fd;
rc = seccomp_init(SCMP_ACT_KILL);
if (rc < 0)
goto out;
/* ... */
filter_fd = open("/tmp/seccomp_filter.bpf", O_WRONLY);
if (filter_fd == -1) {
rc = -errno;
goto out;
}
rc = seccomp_export_bpf(filter_fd);
if (rc < 0) {
close(filter_fd);
goto out;
}
close(filter_fd);
/* ... */
out:
seccomp_release();
return -rc;
}
.fi
.//////////////////////////////////////////////////////////////////////////////
.SH NOTES
.//////////////////////////////////////////////////////////////////////////////
.P
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.
.P
The libseccomp project site, with more information and the source code
repository, can be found at http://libseccomp.sf.net. This library is currently
under development, please report any bugs at the project site or directly to
the author.
.//////////////////////////////////////////////////////////////////////////////
.SH AUTHOR
.//////////////////////////////////////////////////////////////////////////////
Paul Moore <paul@paul-moore.com>
.//////////////////////////////////////////////////////////////////////////////
.SH SEE ALSO
.//////////////////////////////////////////////////////////////////////////////
.BR seccomp_init (3),
.BR seccomp_release (3)
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