granicus.if.org Git - strace/blob - bpf_seccomp_filter.c

   1 /*
   2  * Decoder of seccomp filter programs.
   3  *
   4  * Copyright (c) 2015-2018 Dmitry V. Levin <ldv@altlinux.org>
   5  * All rights reserved.
   6  *
   7  * SPDX-License-Identifier: LGPL-2.1-or-later
   8  */
   9
  10 #include "defs.h"
  11
  12 #include "bpf_filter.h"
  13
  14 #include <linux/filter.h>
  15 #ifdef HAVE_LINUX_SECCOMP_H
  16 # include <linux/seccomp.h>
  17 #endif
  18 #ifndef SECCOMP_RET_ACTION_FULL
  19 # define SECCOMP_RET_ACTION_FULL 0xffff0000U
  20 #endif
  21 #include "xlat/seccomp_ret_action.h"
  22
  23 static bool
  24 print_seccomp_filter_k(const struct bpf_filter_block *const fp)
  25 {
  26         if (BPF_CLASS(fp->code) == BPF_RET) {
  27                 unsigned int action = SECCOMP_RET_ACTION_FULL & fp->k;
  28                 unsigned int data = fp->k & ~action;
  29
  30                 printxval(seccomp_ret_action, action, "SECCOMP_RET_???");
  31                 if (data)
  32                         tprintf("|%#x", data);
  33
  34                 return true;
  35         }
  36
  37         return false;
  38 }
  39
  40 void
  41 print_seccomp_fprog(struct tcb *const tcp, const kernel_ulong_t addr,
  42                     const unsigned short len)
  43 {
  44         print_bpf_fprog(tcp, addr, len, print_seccomp_filter_k);
  45 }
  46
  47 void
  48 decode_seccomp_fprog(struct tcb *const tcp, const kernel_ulong_t addr)
  49 {
  50         decode_bpf_fprog(tcp, addr, print_seccomp_filter_k);
  51 }