1 /* 2 * Copyright (C) 2006 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 #ifndef __CUTILS_SOCKETS_H 18 #define __CUTILS_SOCKETS_H 19 20 #include <errno.h> 21 #include <stdio.h> 22 #include <stdlib.h> 23 #include <string.h> 24 #include <stdbool.h> 25 26 #if defined(_WIN32) 27 28 #include <winsock2.h> 29 #include <ws2tcpip.h> 30 31 typedef int socklen_t; 32 typedef SOCKET cutils_socket_t; 33 34 #else 35 36 #include <sys/socket.h> 37 38 typedef int cutils_socket_t; 39 #define INVALID_SOCKET (-1) 40 41 #endif 42 43 #define ANDROID_SOCKET_ENV_PREFIX "ANDROID_SOCKET_" 44 #define ANDROID_SOCKET_DIR "/dev/socket" 45 46 #ifdef __cplusplus 47 extern "C" { 48 #endif 49 50 /* 51 * android_get_control_socket - simple helper function to get the file 52 * descriptor of our init-managed Unix domain socket. `name' is the name of the 53 * socket, as given in init.rc. Returns -1 on error. 54 * 55 * This is inline and not in libcutils proper because we want to use this in 56 * third-party daemons with minimal modification. 57 */ 58 static inline int android_get_control_socket(const char* name) 59 { 60 char key[64]; 61 snprintf(key, sizeof(key), ANDROID_SOCKET_ENV_PREFIX "%s", name); 62 63 const char* val = getenv(key); 64 if (!val) { 65 return -1; 66 } 67 68 errno = 0; 69 int fd = strtol(val, NULL, 10); 70 if (errno) { 71 return -1; 72 } 73 74 return fd; 75 } 76 77 /* 78 * See also android.os.LocalSocketAddress.Namespace 79 */ 80 // Linux "abstract" (non-filesystem) namespace 81 #define ANDROID_SOCKET_NAMESPACE_ABSTRACT 0 82 // Android "reserved" (/dev/socket) namespace 83 #define ANDROID_SOCKET_NAMESPACE_RESERVED 1 84 // Normal filesystem namespace 85 #define ANDROID_SOCKET_NAMESPACE_FILESYSTEM 2 86 87 /* 88 * Functions to create sockets for some common usages. 89 * 90 * All these functions are implemented for Unix, but only a few are implemented 91 * for Windows. Those which are can be identified by the cutils_socket_t 92 * return type. The idea is to be able to use this return value with the 93 * standard Unix socket functions on any platform. 94 * 95 * On Unix the returned cutils_socket_t is a standard int file descriptor and 96 * can always be used as normal with all file descriptor functions. 97 * 98 * On Windows utils_socket_t is an unsigned int pointer, and is only valid 99 * with functions that specifically take a socket, e.g. send(), sendto(), 100 * recv(), and recvfrom(). General file descriptor functions such as read(), 101 * write(), and close() will not work with utils_socket_t and will require 102 * special handling. 103 * 104 * These functions return INVALID_SOCKET (-1) on failure for all platforms. 105 */ 106 int socket_loopback_client(int port, int type); 107 cutils_socket_t socket_network_client(const char* host, int port, int type); 108 int socket_network_client_timeout(const char* host, int port, int type, 109 int timeout, int* getaddrinfo_error); 110 int socket_loopback_server(int port, int type); 111 int socket_local_server(const char* name, int namespaceId, int type); 112 int socket_local_server_bind(int s, const char* name, int namespaceId); 113 int socket_local_client_connect(int fd, const char *name, int namespaceId, 114 int type); 115 int socket_local_client(const char* name, int namespaceId, int type); 116 cutils_socket_t socket_inaddr_any_server(int port, int type); 117 118 /* 119 * Closes a cutils_socket_t. Windows doesn't allow calling close() on a socket 120 * so this is a cross-platform way to close a cutils_socket_t. 121 * 122 * Returns 0 on success. 123 */ 124 int socket_close(cutils_socket_t sock); 125 126 /* 127 * Sets socket receive timeout using SO_RCVTIMEO. Setting |timeout_ms| to 0 128 * disables receive timeouts. 129 * 130 * Return 0 on success. 131 */ 132 int socket_set_receive_timeout(cutils_socket_t sock, int timeout_ms); 133 134 /* 135 * Returns the local port the socket is bound to or -1 on error. 136 */ 137 int socket_get_local_port(cutils_socket_t sock); 138 139 /* 140 * Sends to a socket from multiple buffers; wraps writev() on Unix or WSASend() 141 * on Windows. This can give significant speedup compared to calling send() 142 * multiple times. 143 * 144 * Example usage: 145 * cutils_socket_buffer_t buffers[2] = { {data0, len0}, {data1, len1} }; 146 * socket_send_buffers(sock, buffers, 2); 147 * 148 * If you try to pass more than SOCKET_SEND_BUFFERS_MAX_BUFFERS buffers into 149 * this function it will return -1 without sending anything. 150 * 151 * Returns the number of bytes written or -1 on error. 152 */ 153 typedef struct { 154 const void* data; 155 size_t length; 156 } cutils_socket_buffer_t; 157 158 #define SOCKET_SEND_BUFFERS_MAX_BUFFERS 16 159 160 ssize_t socket_send_buffers(cutils_socket_t sock, 161 const cutils_socket_buffer_t* buffers, 162 size_t num_buffers); 163 164 /* 165 * socket_peer_is_trusted - Takes a socket which is presumed to be a 166 * connected local socket (e.g. AF_LOCAL) and returns whether the peer 167 * (the userid that owns the process on the other end of that socket) 168 * is one of the two trusted userids, root or shell. 169 * 170 * Note: This only works as advertised on the Android OS and always 171 * just returns true when called on other operating systems. 172 */ 173 extern bool socket_peer_is_trusted(int fd); 174 175 #ifdef __cplusplus 176 } 177 #endif 178 179 #endif /* __CUTILS_SOCKETS_H */ 180
