1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "sysdeps/network.h" 18 19 #include <errno.h> 20 #include <netinet/in.h> 21 #include <sys/socket.h> 22 23 #include <string> 24 25 #include "adb_unique_fd.h" 26 27 static void set_error(std::string* error) { 28 if (error) { 29 *error = strerror(errno); 30 } 31 } 32 33 static sockaddr* loopback_addr4(sockaddr_storage* addr, socklen_t* addrlen, int port) { 34 struct sockaddr_in* addr4 = reinterpret_cast<sockaddr_in*>(addr); 35 *addrlen = sizeof(*addr4); 36 37 addr4->sin_family = AF_INET; 38 addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK); 39 addr4->sin_port = htons(port); 40 return reinterpret_cast<sockaddr*>(addr); 41 } 42 43 static sockaddr* loopback_addr6(sockaddr_storage* addr, socklen_t* addrlen, int port) { 44 struct sockaddr_in6* addr6 = reinterpret_cast<sockaddr_in6*>(addr); 45 *addrlen = sizeof(*addr6); 46 47 addr6->sin6_family = AF_INET6; 48 addr6->sin6_addr = in6addr_loopback; 49 addr6->sin6_port = htons(port); 50 return reinterpret_cast<sockaddr*>(addr); 51 } 52 53 static int _network_loopback_client(bool ipv6, int port, int type, std::string* error) { 54 unique_fd s(socket(ipv6 ? AF_INET6 : AF_INET, type, 0)); 55 if (s == -1) { 56 set_error(error); 57 return -1; 58 } 59 60 struct sockaddr_storage addr_storage = {}; 61 socklen_t addrlen = sizeof(addr_storage); 62 sockaddr* addr = (ipv6 ? loopback_addr6 : loopback_addr4)(&addr_storage, &addrlen, 0); 63 64 if (bind(s.get(), addr, addrlen) != 0) { 65 set_error(error); 66 return -1; 67 } 68 69 addr = (ipv6 ? loopback_addr6 : loopback_addr4)(&addr_storage, &addrlen, port); 70 71 if (connect(s.get(), addr, addrlen) != 0) { 72 set_error(error); 73 return -1; 74 } 75 76 return s.release(); 77 } 78 79 int network_loopback_client(int port, int type, std::string* error) { 80 // Try IPv4 first, use IPv6 as a fallback. 81 int rc = _network_loopback_client(false, port, type, error); 82 if (rc == -1) { 83 return _network_loopback_client(true, port, type, error); 84 } 85 return rc; 86 } 87 88 static int _network_loopback_server(bool ipv6, int port, int type, std::string* error) { 89 unique_fd s(socket(ipv6 ? AF_INET6 : AF_INET, type, 0)); 90 if (s == -1) { 91 set_error(error); 92 return -1; 93 } 94 95 int n = 1; 96 setsockopt(s.get(), SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n)); 97 98 struct sockaddr_storage addr_storage = {}; 99 socklen_t addrlen = sizeof(addr_storage); 100 sockaddr* addr = (ipv6 ? loopback_addr6 : loopback_addr4)(&addr_storage, &addrlen, port); 101 102 if (bind(s, addr, addrlen) != 0) { 103 set_error(error); 104 return -1; 105 } 106 107 if (type == SOCK_STREAM || type == SOCK_SEQPACKET) { 108 // Arbitrarily selected value, ported from libcutils. 109 if (listen(s, 4) != 0) { 110 set_error(error); 111 return -1; 112 } 113 } 114 115 return s.release(); 116 } 117 118 int network_loopback_server(int port, int type, std::string* error) { 119 int rc = _network_loopback_server(false, port, type, error); 120 121 // Only attempt to listen on IPv6 if IPv4 is unavailable. 122 // We don't want to start an IPv6 server if there's already an IPv4 one running. 123 if (rc == -1 && (errno == EADDRNOTAVAIL || errno == EAFNOSUPPORT)) { 124 return _network_loopback_server(true, port, type, error); 125 } 126 return rc; 127 } 128
