seccomp_merge(3) — Linux manual page

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 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)

COLOPHON

       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 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-04-18.)  If you discover 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            30 May 2020              seccomp_merge(3)

Pages that refer to this page: seccomp_arch_add(3)

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