Added a new Verifier class to the BPF compiler.

sandbox/linux/seccomp-bpf/verifier.h

Index: sandbox/linux/seccomp-bpf/verifier.h
diff --git a/sandbox/linux/seccomp-bpf/verifier.h b/sandbox/linux/seccomp-bpf/verifier.h
new file mode 100644
index 0000000000000000000000000000000000000000..f189251a0c763358d3499675a03554b5533d73bf
--- /dev/null
+++ b/sandbox/linux/seccomp-bpf/verifier.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2012 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.
+
+#ifndef VERIFIER_H__
+#define VERIFIER_H__
+
+#include <linux/filter.h>
+
+#include <utility>
+#include <vector>
+
+#include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
+
+
+namespace playground2 {
+
+class Verifier {
+ public:

[jln (very slow on Chromium), 2012/06/07 22:55:17]

I would really prefer if this returned a bool or an int.

We really want the caller to be able to make the decision of what to do next.

There are two likely callers:
1. our own code in sandbox_bpf.cc -> we can handle error fine
2. tests -> It's nice if we can put some stuff in automated tests. die() / exit
make this really painful.

+  static void verifyBPF(const std::vector<struct sock_filter>& program,
+                        const Sandbox::Evaluators& evaluators);
+
+ private:
+  struct State {
+    State(const std::vector<struct sock_filter>& p,
+          int s, Sandbox::ErrorCode e) :
+      program(p),
+      sysnum(s),
+      err(e),
+      ip(0),
+      accumulator(0),
+      accIsValid(false) {
+    }
+    const std::vector<struct sock_filter>& program;
+    int                                    sysnum;
+    Sandbox::ErrorCode                     err;
+    unsigned int                           ip;
+    uint32_t                               accumulator;
+    bool                                   accIsValid;
+  };
+
+  static void ld (State *state, const struct sock_filter& insn);
+  static void jmp(State *state, const struct sock_filter& insn);
+  static void ret(State *state, const struct sock_filter& insn);

[jln (very slow on Chromium), 2012/06/07 22:55:17]

Looks like Verifier is not meant to be instanciated. Do you mind to make the
constructor private etc? Chrome provides helpers for this.

+};
+
+}  // namespace
+
+#endif  // VERIFIER_H__