1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__ 6 #define SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__ 7 8 #include <linux/filter.h> 9 10 #include <utility> 11 #include <vector> 12 13 namespace sandbox { 14 15 class SandboxBPFPolicy; 16 17 class Verifier { 18 public: 19 // Evaluate the BPF program for all possible inputs and verify that it 20 // computes the correct result. We use the "evaluators" to determine 21 // the full set of possible inputs that we have to iterate over. 22 // Returns success, if the BPF filter accurately reflects the rules 23 // set by the "evaluators". 24 // Upon success, "err" is set to NULL. Upon failure, it contains a static 25 // error message that does not need to be free()'d. 26 static bool VerifyBPF(SandboxBPF* sandbox, 27 const std::vector<struct sock_filter>& program, 28 const SandboxBPFPolicy& policy, 29 const char** err); 30 31 // Evaluate a given BPF program for a particular set of system call 32 // parameters. If evaluation failed for any reason, "err" will be set to 33 // a non-NULL error string. Otherwise, the BPF program's result will be 34 // returned by the function and "err" is NULL. 35 // We do not actually implement the full BPF state machine, but only the 36 // parts that can actually be generated by our BPF compiler. If this code 37 // is used for purposes other than verifying the output of the sandbox's 38 // BPF compiler, we might have to extend this BPF interpreter. 39 static uint32_t EvaluateBPF(const std::vector<struct sock_filter>& program, 40 const struct arch_seccomp_data& data, 41 const char** err); 42 43 private: 44 DISALLOW_IMPLICIT_CONSTRUCTORS(Verifier); 45 }; 46 47 } // namespace sandbox 48 49 #endif // SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__ 50