text: // Copyright 2014 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "sandbox/linux/bpf_dsl/dump_bpf.h"
  
  #include <stdio.h>
  
  #include "sandbox/linux/bpf_dsl/codegen.h"
  #include "sandbox/linux/bpf_dsl/trap_registry.h"
  #include "sandbox/linux/system_headers/linux_seccomp.h"
  
  namespace sandbox {
  namespace bpf_dsl {
  
  void DumpBPF::PrintProgram(const CodeGen::Program& program) {
    for (CodeGen::Program::const_iterator iter = program.begin();
         iter != program.end();
         ++iter) {
      int ip = (int)(iter - program.begin());
      fprintf(stderr, "%3d) ", ip);
      switch (BPF_CLASS(iter->code)) {
        case BPF_LD:
          if (iter->code == BPF_LD + BPF_W + BPF_ABS) {
            fprintf(stderr, "LOAD %d  // ", (int)iter->k);
            if (iter->k == offsetof(struct arch_seccomp_data, nr)) {
              fprintf(stderr, "System call number\n");
            } else if (iter->k == offsetof(struct arch_seccomp_data, arch)) {
              fprintf(stderr, "Architecture\n");
            } else if (iter->k ==
                       offsetof(struct arch_seccomp_data, instruction_pointer)) {
              fprintf(stderr, "Instruction pointer (LSB)\n");
            } else if (iter->k ==
                       offsetof(struct arch_seccomp_data, instruction_pointer) +
                           4) {
              fprintf(stderr, "Instruction pointer (MSB)\n");
            } else if (iter->k >= offsetof(struct arch_seccomp_data, args) &&
                       iter->k < offsetof(struct arch_seccomp_data, args) + 48 &&
                       (iter->k - offsetof(struct arch_seccomp_data, args)) % 4 ==
                           0) {
              fprintf(
                  stderr,
                  "Argument %d (%cSB)\n",
                  (int)(iter->k - offsetof(struct arch_seccomp_data, args)) / 8,
                  (iter->k - offsetof(struct arch_seccomp_data, args)) % 8 ? 'M'
                                                                           : 'L');
            } else {
              fprintf(stderr, "???\n");
            }
          } else {
            fprintf(stderr, "LOAD ???\n");
          }
          break;
        case BPF_JMP:
          if (BPF_OP(iter->code) == BPF_JA) {
            fprintf(stderr, "JMP %d\n", ip + iter->k + 1);
          } else {
            fprintf(stderr, "if A %s 0x%x; then JMP %d else JMP %d\n",
                BPF_OP(iter->code) == BPF_JSET ? "&" :
                BPF_OP(iter->code) == BPF_JEQ ? "==" :
                BPF_OP(iter->code) == BPF_JGE ? ">=" :
                BPF_OP(iter->code) == BPF_JGT ? ">"  : "???",
                (int)iter->k,
                ip + iter->jt + 1, ip + iter->jf + 1);
          }
          break;
        case BPF_RET:
          fprintf(stderr, "RET 0x%x  // ", iter->k);
          if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRAP) {
            fprintf(stderr, "Trap #%d\n", iter->k & SECCOMP_RET_DATA);
          } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_ERRNO) {
            fprintf(stderr, "errno = %d\n", iter->k & SECCOMP_RET_DATA);
          } else if ((iter->k & SECCOMP_RET_ACTION) == SECCOMP_RET_TRACE) {
            fprintf(stderr, "Trace #%d\n", iter->k & SECCOMP_RET_DATA);
          } else if (iter->k == SECCOMP_RET_ALLOW) {
            fprintf(stderr, "Allowed\n");
          } else {
            fprintf(stderr, "???\n");
          }
          break;
        case BPF_ALU:
          fprintf(stderr, BPF_OP(iter->code) == BPF_NEG
              ? "A := -A\n" : "A := A %s 0x%x\n",
              BPF_OP(iter->code) == BPF_ADD ? "+"  :
              BPF_OP(iter->code) == BPF_SUB ? "-"  :
              BPF_OP(iter->code) == BPF_MUL ? "*"  :
              BPF_OP(iter->code) == BPF_DIV ? "/"  :
              BPF_OP(iter->code) == BPF_MOD ? "%"  :
              BPF_OP(iter->code) == BPF_OR  ? "|"  :
              BPF_OP(iter->code) == BPF_XOR ? "^"  :
              BPF_OP(iter->code) == BPF_AND ? "&"  :
              BPF_OP(iter->code) == BPF_LSH ? "<<" :
              BPF_OP(iter->code) == BPF_RSH ? ">>" : "???",
              (int)iter->k);
          break;
        default:
          fprintf(stderr, "???\n");
          break;
      }
    }
    return;
  }
  
  }  // namespace bpf_dsl
  }  // namespace sandbox
  