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 successful, the src seccomp filter is released
       and  all  internal  memory  associated  with the filter is freed; there is no need to call
       seccomp_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 or one of the following error codes on failure:

       -EDOM  Unable  to  merge  the  filters  due  to  architecture  issues,  e.g.  byte  endian
              mismatches.

       -EEXIST
              The architecture already exists in the filter.

       -EINVAL
              One of the filters is invalid.

       -ENOMEM
              The library was unable to allocate enough memory.

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            /* NOTE: the 'ctx_32' filter is no longer valid at this point */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

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)