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 14 namespace playground2 { 15 16 class Verifier { 17 public: 18 // Evaluate the BPF program for all possible inputs and verify that it 19 // computes the correct result. We use the "evaluators" to determine 20 // the full set of possible inputs that we have to iterate over. 21 // Returns success, if the BPF filter accurately reflects the rules 22 // set by the "evaluators". 23 // Upon success, "err" is set to NULL. Upon failure, it contains a static 24 // error message that does not need to be free()'d. 25 static bool VerifyBPF(Sandbox *sandbox, 26 const std::vector<struct sock_filter>& program, 27 const Sandbox::Evaluators& evaluators, 28 const char **err); 29 30 // Evaluate a given BPF program for a particular set of system call 31 // parameters. If evaluation failed for any reason, "err" will be set to 32 // a non-NULL error string. Otherwise, the BPF program's result will be 33 // returned by the function and "err" is NULL. 34 // We do not actually implement the full BPF state machine, but only the 35 // parts that can actually be generated by our BPF compiler. If this code 36 // is used for purposes other than verifying the output of the sandbox's 37 // BPF compiler, we might have to extend this BPF interpreter. 38 static uint32_t EvaluateBPF(const std::vector<struct sock_filter>& program, 39 const struct arch_seccomp_data& data, 40 const char **err); 41 42 private: 43 DISALLOW_IMPLICIT_CONSTRUCTORS(Verifier); 44 }; 45 46 } // namespace 47 48 #endif // SANDBOX_LINUX_SECCOMP_BPF_VERIFIER_H__ 49