1 /* Copyright 2016 The TensorFlow Authors. All Rights Reserved. 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 http://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 16 #include "tensorflow/core/platform/net.h" 17 18 #include <cerrno> 19 #include <cstdlib> 20 #include <unordered_set> 21 22 #include <netinet/in.h> 23 #include <sys/socket.h> 24 #include <sys/types.h> 25 #include <unistd.h> 26 27 #include "tensorflow/core/lib/strings/strcat.h" 28 #include "tensorflow/core/platform/logging.h" 29 30 namespace tensorflow { 31 namespace internal { 32 33 namespace { 34 bool IsPortAvailable(int* port, bool is_tcp) { 35 const int protocol = is_tcp ? IPPROTO_TCP : 0; 36 const int fd = socket(AF_INET, is_tcp ? SOCK_STREAM : SOCK_DGRAM, protocol); 37 38 struct sockaddr_in addr; 39 socklen_t addr_len = sizeof(addr); 40 int actual_port; 41 42 CHECK_GE(*port, 0); 43 CHECK_LE(*port, 65535); 44 if (fd < 0) { 45 LOG(ERROR) << "socket() failed: " << strerror(errno); 46 return false; 47 } 48 49 // SO_REUSEADDR lets us start up a server immediately after it exists. 50 int one = 1; 51 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) { 52 LOG(ERROR) << "setsockopt() failed: " << strerror(errno); 53 close(fd); 54 return false; 55 } 56 57 // Try binding to port. 58 addr.sin_family = AF_INET; 59 addr.sin_addr.s_addr = INADDR_ANY; 60 addr.sin_port = htons(static_cast<uint16_t>(*port)); 61 if (bind(fd, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)) < 0) { 62 LOG(WARNING) << "bind(port=" << *port << ") failed: " << strerror(errno); 63 close(fd); 64 return false; 65 } 66 67 // Get the bound port number. 68 if (getsockname(fd, reinterpret_cast<struct sockaddr*>(&addr), &addr_len) < 69 0) { 70 LOG(WARNING) << "getsockname() failed: " << strerror(errno); 71 close(fd); 72 return false; 73 } 74 CHECK_LE(addr_len, sizeof(addr)); 75 actual_port = ntohs(addr.sin_port); 76 CHECK_GT(actual_port, 0); 77 if (*port == 0) { 78 *port = actual_port; 79 } else { 80 CHECK_EQ(*port, actual_port); 81 } 82 close(fd); 83 return true; 84 } 85 86 const int kNumRandomPortsToPick = 100; 87 const int kMaximumTrials = 1000; 88 89 } // namespace 90 91 int PickUnusedPortOrDie() { 92 static std::unordered_set<int> chosen_ports; 93 94 // Type of port to first pick in the next iteration. 95 bool is_tcp = true; 96 int trial = 0; 97 while (true) { 98 int port; 99 trial++; 100 CHECK_LE(trial, kMaximumTrials) 101 << "Failed to pick an unused port for testing."; 102 if (trial == 1) { 103 port = getpid() % (65536 - 30000) + 30000; 104 } else if (trial <= kNumRandomPortsToPick) { 105 port = rand() % (65536 - 30000) + 30000; 106 } else { 107 port = 0; 108 } 109 110 if (chosen_ports.find(port) != chosen_ports.end()) { 111 continue; 112 } 113 if (!IsPortAvailable(&port, is_tcp)) { 114 continue; 115 } 116 117 CHECK_GT(port, 0); 118 if (!IsPortAvailable(&port, !is_tcp)) { 119 is_tcp = !is_tcp; 120 continue; 121 } 122 123 chosen_ports.insert(port); 124 return port; 125 } 126 127 return 0; 128 } 129 130 } // namespace internal 131 } // namespace tensorflow 132
