seccomp_merge(3)					     libseccomp Documentation						  seccomp_merge(3)

NAME

       seccomp_merge - Merge two seccomp filters

SYNOPSIS

       #include <seccomp.h>

       typedef void * scmp_filter_ctx;

       int seccomp_merge(scmp_filter_ctx dst, scmp_filter_ctx src);

       Link with -lseccomp.

DESCRIPTION

       The  seccomp_merge()  function merges the seccomp filter in src with the filter in dst and stores the resulting in the dst filter.  If suc-
       cessfull, the src seccomp filter is released and all internal memory assocated with the filter is freed; there is  no  need  to	call  sec-
       comp_release(3) on src and the caller should discard any references to the filter.

       In order to merge two seccomp filters, both filters must have the same attribute values and no overlapping architectures.

RETURN VALUE

       Returns zero on success and negative values on failure.

EXAMPLES

       #include <seccomp.h>

       int main(int argc, char *argv[])
       {
	    int rc = -1;
	    scmp_filter_ctx ctx_32, ctx_64;

	    ctx_32 = seccomp_init(SCMP_ACT_KILL);
	    if (ctx_32 == NULL)
		 goto out_all;
	    ctx_64 = seccomp_init(SCMP_ACT_KILL);
	    if (ctx_64 == NULL)
		 goto out_all;

	    if (seccomp_arch_exist(ctx_32, SCMP_ARCH_X86) == -EEXIST) {
		 rc = seccomp_arch_add(ctx_32, SCMP_ARCH_X86);
		 if (rc != 0)
		      goto out_all;
		 rc = seccomp_arch_remove(ctx_32, SCMP_ARCH_NATIVE);
		 if (rc != 0)
		      goto out_all;
	    }
	    if (seccomp_arch_exist(ctx_64, SCMP_ARCH_X86_64) == -EEXIST) {
		 rc = seccomp_arch_add(ctx_64, SCMP_ARCH_X86_64);
		 if (rc != 0)
		      goto out_all;
		 rc = seccomp_arch_remove(ctx_64, SCMP_ARCH_NATIVE);
		 if (rc != 0)
		      goto out_all;
	    }

	    /* ... */

	    rc = seccomp_merge(ctx_64, ctx_32);
	    if (rc != 0)
		 goto out_all;

	    /* NOTE: the 'ctx_32' filter is no longer valid at this point */

	    /* ... */

       out:
	    seccomp_release(ctx_64);
	    return -rc;
       out_all:
	    seccomp_release(ctx_32);
	    goto out;
       }

NOTES

       While the seccomp filter can be generated independent of the kernel, kernel support is required to load and enforce the seccomp filter gen-
       erated by libseccomp.

       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.

AUTHOR

       Paul Moore <paul@paul-moore.com>

SEE ALSO

       seccomp_init(3), seccomp_reset(3), seccomp_arch_add(3), seccomp_arch_remove(3), seccomp_attr_get(3), seccomp_attr_set(3)

paul@paul-moore.com						 28 September 2012						  seccomp_merge(3)