sandbox: extract PrintProgram() into a separate DumpBPF class

Removes some dependencies from codegen.cc as it now only deals with
emitting programs, not with disassembling them too.

BUG=414363

Review URL: https://codereview.chromium.org/694013002

Cr-Commit-Position: refs/heads/master@{#302323}

3 files changed, 3 insertions, 95 deletions

diff --git a/sandbox/linux/seccomp-bpf/codegen.cc b/sandbox/linux/seccomp-bpf/codegen.cc
index 8169840..1ee79b6 100644
--- a/sandbox/linux/seccomp-bpf/codegen.cc
+++ b/sandbox/linux/seccomp-bpf/codegen.cc
@@ -4,7 +4,7 @@
 
 #include "sandbox/linux/seccomp-bpf/codegen.h"
 
-#include <stdio.h>
+#include <linux/filter.h>
 
 #include <set>
 
@@ -12,8 +12,6 @@
 #include "sandbox/linux/seccomp-bpf/basicblock.h"
 #include "sandbox/linux/seccomp-bpf/die.h"
 #include "sandbox/linux/seccomp-bpf/instruction.h"
-#include "sandbox/linux/seccomp-bpf/linux_seccomp.h"
-#include "sandbox/linux/seccomp-bpf/trap.h"
 
 namespace sandbox {
 
@@ -32,93 +30,6 @@ CodeGen::~CodeGen() {
   }
 }
 
-void CodeGen::PrintProgram(const Program& program) {
-  for (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;
-}
-
 Instruction* CodeGen::MakeInstruction(uint16_t code,
                                       uint32_t k,
                                       Instruction* next) {
diff --git a/sandbox/linux/seccomp-bpf/codegen.h b/sandbox/linux/seccomp-bpf/codegen.h
index 817b17c..671b09e 100644
--- a/sandbox/linux/seccomp-bpf/codegen.h
+++ b/sandbox/linux/seccomp-bpf/codegen.h
@@ -63,10 +63,6 @@ class SANDBOX_EXPORT CodeGen {
   CodeGen();
   ~CodeGen();
 
-  // This is a helper method that can be used for debugging purposes. It is
-  // not normally called.
-  static void PrintProgram(const Program& program);
-
   // Create a new instruction. Instructions form a DAG. The instruction objects
   // are owned by the CodeGen object. They do not need to be explicitly
   // deleted.
diff --git a/sandbox/linux/seccomp-bpf/sandbox_bpf.cc b/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
index 8292ae6..d5a5d4d 100644
--- a/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
+++ b/sandbox/linux/seccomp-bpf/sandbox_bpf.cc
@@ -29,6 +29,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/posix/eintr_wrapper.h"
 #include "sandbox/linux/bpf_dsl/bpf_dsl.h"
+#include "sandbox/linux/bpf_dsl/dump_bpf.h"
 #include "sandbox/linux/bpf_dsl/policy.h"
 #include "sandbox/linux/bpf_dsl/policy_compiler.h"
 #include "sandbox/linux/seccomp-bpf/codegen.h"
@@ -495,7 +496,7 @@ scoped_ptr<CodeGen::Program> SandboxBPF::AssembleFilter(
 
     const char* err = NULL;
     if (!Verifier::VerifyBPF(&compiler, *program, *policy_, &err)) {
-      CodeGen::PrintProgram(*program);
+      bpf_dsl::DumpBPF::PrintProgram(*program);
       SANDBOX_DIE(err);
     }
   }