// 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 SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__
#define SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__
#include <linux/filter.h>
#include <utility>
#include <vector>
namespace sandbox {
class SandboxBPFPolicy;
class Verifier {
public:
// Evaluate the BPF program for all possible inputs and verify that it
// computes the correct result. We use the "evaluators" to determine
// the full set of possible inputs that we have to iterate over.
// Returns success, if the BPF filter accurately reflects the rules
// set by the "evaluators".
// Upon success, "err" is set to NULL. Upon failure, it contains a static
// error message that does not need to be free()'d.
static bool VerifyBPF(SandboxBPF* sandbox,
const std::vector<struct sock_filter>& program,
const SandboxBPFPolicy& policy,
const char** err);
// Evaluate a given BPF program for a particular set of system call
// parameters. If evaluation failed for any reason, "err" will be set to
// a non-NULL error string. Otherwise, the BPF program's result will be
// returned by the function and "err" is NULL.
// We do not actually implement the full BPF state machine, but only the
// parts that can actually be generated by our BPF compiler. If this code
// is used for purposes other than verifying the output of the sandbox's
// BPF compiler, we might have to extend this BPF interpreter.
static uint32_t EvaluateBPF(const std::vector<struct sock_filter>& program,
const struct arch_seccomp_data& data,
const char** err);
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(Verifier);
};
} // namespace sandbox
#endif // SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__