libseccomp/doc/man/man3/seccomp_merge.3

   1 .TH "seccomp_merge" 3 "28 September 2012" "paul@paul-moore.com" "libseccomp Documentation"
   2 .\" //////////////////////////////////////////////////////////////////////////
   3 .SH NAME
   4 .\" //////////////////////////////////////////////////////////////////////////
   5 seccomp_merge \- Merge two seccomp filters
   6 .\" //////////////////////////////////////////////////////////////////////////
   7 .SH SYNOPSIS
   8 .\" //////////////////////////////////////////////////////////////////////////
   9 .nf
  10 .B #include <seccomp.h>
  11 .sp
  12 .B typedef void * scmp_filter_ctx;
  13 .sp
  14 .BI "int seccomp_merge(scmp_filter_ctx " dst ", scmp_filter_ctx " src ");"
  15 .sp
  16 Link with \fI\-lseccomp\fP.
  17 .fi
  18 .\" //////////////////////////////////////////////////////////////////////////
  19 .SH DESCRIPTION
  20 .\" //////////////////////////////////////////////////////////////////////////
  21 .P
  22 The
  23 .BR seccomp_merge ()
  24 function merges the seccomp filter in
  25 .I src
  26 with the filter in
  27 .I dst
  28 and stores the resulting in the
  29 .I dst
  30 filter.  If successfull, the
  31 .I src
  32 seccomp filter is released and all internal memory assocated with the filter
  33 is freed; there is no need to call
  34 .BR seccomp_release (3)
  35 on
  36 .I src
  37 and the caller should discard any references to the filter.
  38 .P
  39 In order to merge two seccomp filters, both filters must have the same
  40 attribute values and no overlapping architectures.
  41 .\" //////////////////////////////////////////////////////////////////////////
  42 .SH RETURN VALUE
  43 .\" //////////////////////////////////////////////////////////////////////////
  44 Returns zero on success and negative values on failure.
  45 .\" //////////////////////////////////////////////////////////////////////////
  46 .SH EXAMPLES
  47 .\" //////////////////////////////////////////////////////////////////////////
  48 .nf
  49 #include <seccomp.h>
  50
  51 int main(int argc, char *argv[])
  52 {
  53         int rc = \-1;
  54         scmp_filter_ctx ctx_32, ctx_64;
  55
  56         ctx_32 = seccomp_init(SCMP_ACT_KILL);
  57         if (ctx_32 == NULL)
  58                 goto out_all;
  59         ctx_64 = seccomp_init(SCMP_ACT_KILL);
  60         if (ctx_64 == NULL)
  61                 goto out_all;
  62
  63         if (seccomp_arch_exist(ctx_32, SCMP_ARCH_X86) == \-EEXIST) {
  64                 rc = seccomp_arch_add(ctx_32, SCMP_ARCH_X86);
  65                 if (rc != 0)
  66                         goto out_all;
  67                 rc = seccomp_arch_remove(ctx_32, SCMP_ARCH_NATIVE);
  68                 if (rc != 0)
  69                         goto out_all;
  70         }
  71         if (seccomp_arch_exist(ctx_64, SCMP_ARCH_X86_64) == \-EEXIST) {
  72                 rc = seccomp_arch_add(ctx_64, SCMP_ARCH_X86_64);
  73                 if (rc != 0)
  74                         goto out_all;
  75                 rc = seccomp_arch_remove(ctx_64, SCMP_ARCH_NATIVE);
  76                 if (rc != 0)
  77                         goto out_all;
  78         }
  79
  80         /* ... */
  81
  82         rc = seccomp_merge(ctx_64, ctx_32);
  83         if (rc != 0)
  84                 goto out_all;
  85
  86         /* NOTE: the 'ctx_32' filter is no longer valid at this point */
  87
  88         /* ... */
  89
  90 out:
  91         seccomp_release(ctx_64);
  92         return \-rc;
  93 out_all:
  94         seccomp_release(ctx_32);
  95         goto out;
  96 }
  97 .fi
  98 .\" //////////////////////////////////////////////////////////////////////////
  99 .SH NOTES
 100 .\" //////////////////////////////////////////////////////////////////////////
 101 .P
 102 While the seccomp filter can be generated independent of the kernel, kernel
 103 support is required to load and enforce the seccomp filter generated by
 104 libseccomp.
 105 .P
 106 The libseccomp project site, with more information and the source code
 107 repository, can be found at https://github.com/seccomp/libseccomp.  This tool,
 108 as well as the libseccomp library, is currently under development, please
 109 report any bugs at the project site or directly to the author.
 110 .\" //////////////////////////////////////////////////////////////////////////
 111 .SH AUTHOR
 112 .\" //////////////////////////////////////////////////////////////////////////
 113 Paul Moore <paul@paul-moore.com>
 114 .\" //////////////////////////////////////////////////////////////////////////
 115 .SH SEE ALSO
 116 .\" //////////////////////////////////////////////////////////////////////////
 117 .BR seccomp_init (3),
 118 .BR seccomp_reset (3),
 119 .BR seccomp_arch_add (3),
 120 .BR seccomp_arch_remove (3),
 121 .BR seccomp_attr_get (3),
 122 .BR seccomp_attr_set (3)