1 // Copyright 2019 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #include "sandboxed_api/sandbox2/forkingclient.h" 16 17 #include <unistd.h> 18 19 #include <cstdlib> 20 #include <memory> 21 22 #include "absl/log/check.h" 23 #include "absl/log/log.h" 24 #include "sandboxed_api/sandbox2/forkserver.h" 25 #include "sandboxed_api/sandbox2/sanitizer.h" 26 27 namespace sandbox2 { 28 WaitAndFork()29pid_t ForkingClient::WaitAndFork() { 30 // We don't instantiate the Fork-Server until the first Fork() call takes 31 // place (in order to conserve resources, and avoid calling Fork-Server 32 // initialization routines). 33 if (!fork_server_worker_) { 34 sanitizer::WaitForSanitizer(); 35 // Perform that check once only, because it's quite CPU-expensive. 36 int n = sanitizer::GetNumberOfThreads(getpid()); 37 CHECK_NE(n, -1) << "sanitizer::GetNumberOfThreads failed"; 38 CHECK_EQ(n, 1) << "Too many threads (" << n 39 << ") during sandbox2::Client::WaitAndFork()"; 40 fork_server_worker_ = std::make_unique<ForkServer>(comms_); 41 } 42 pid_t pid = fork_server_worker_->ServeRequest(); 43 if (pid == -1 && fork_server_worker_->IsTerminated()) { 44 VLOG(1) << "ForkServer Comms closed. Exiting"; 45 exit(0); 46 } 47 return pid; 48 } 49 50 } // namespace sandbox2 51