1 /** 2 * \file net_sockets.h 3 * 4 * \brief Network sockets abstraction layer to integrate Mbed TLS into a 5 * BSD-style sockets API. 6 * 7 * The network sockets module provides an example integration of the 8 * Mbed TLS library into a BSD sockets implementation. The module is 9 * intended to be an example of how Mbed TLS can be integrated into a 10 * networking stack, as well as to be Mbed TLS's network integration 11 * for its supported platforms. 12 * 13 * The module is intended only to be used with the Mbed TLS library and 14 * is not intended to be used by third party application software 15 * directly. 16 * 17 * The supported platforms are as follows: 18 * * Microsoft Windows and Windows CE 19 * * POSIX/Unix platforms including Linux, OS X 20 * 21 */ 22 /* 23 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved 24 * SPDX-License-Identifier: Apache-2.0 25 * 26 * Licensed under the Apache License, Version 2.0 (the "License"); you may 27 * not use this file except in compliance with the License. 28 * You may obtain a copy of the License at 29 * 30 * http://www.apache.org/licenses/LICENSE-2.0 31 * 32 * Unless required by applicable law or agreed to in writing, software 33 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 34 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 35 * See the License for the specific language governing permissions and 36 * limitations under the License. 37 * 38 * This file is part of mbed TLS (https://tls.mbed.org) 39 */ 40 #ifndef MBEDTLS_NET_SOCKETS_H 41 #define MBEDTLS_NET_SOCKETS_H 42 43 #if !defined(MBEDTLS_CONFIG_FILE) 44 #include "config.h" 45 #else 46 #include MBEDTLS_CONFIG_FILE 47 #endif 48 49 #include "ssl.h" 50 51 #include <stddef.h> 52 #include <stdint.h> 53 54 #define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042 /**< Failed to open a socket. */ 55 #define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044 /**< The connection to the given server / port failed. */ 56 #define MBEDTLS_ERR_NET_BIND_FAILED -0x0046 /**< Binding of the socket failed. */ 57 #define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048 /**< Could not listen on the socket. */ 58 #define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A /**< Could not accept the incoming connection. */ 59 #define MBEDTLS_ERR_NET_RECV_FAILED -0x004C /**< Reading information from the socket failed. */ 60 #define MBEDTLS_ERR_NET_SEND_FAILED -0x004E /**< Sending information through the socket failed. */ 61 #define MBEDTLS_ERR_NET_CONN_RESET -0x0050 /**< Connection was reset by peer. */ 62 #define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052 /**< Failed to get an IP address for the given hostname. */ 63 #define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043 /**< Buffer is too small to hold the data. */ 64 #define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045 /**< The context is invalid, eg because it was free()ed. */ 65 #define MBEDTLS_ERR_NET_POLL_FAILED -0x0047 /**< Polling the net context failed. */ 66 #define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049 /**< Input invalid. */ 67 68 #define MBEDTLS_NET_LISTEN_BACKLOG 10 /**< The backlog that listen() should use. */ 69 70 #define MBEDTLS_NET_PROTO_TCP 0 /**< The TCP transport protocol */ 71 #define MBEDTLS_NET_PROTO_UDP 1 /**< The UDP transport protocol */ 72 73 #define MBEDTLS_NET_POLL_READ 1 /**< Used in \c mbedtls_net_poll to check for pending data */ 74 #define MBEDTLS_NET_POLL_WRITE 2 /**< Used in \c mbedtls_net_poll to check if write possible */ 75 76 #ifdef __cplusplus 77 extern "C" { 78 #endif 79 80 /** 81 * Wrapper type for sockets. 82 * 83 * Currently backed by just a file descriptor, but might be more in the future 84 * (eg two file descriptors for combined IPv4 + IPv6 support, or additional 85 * structures for hand-made UDP demultiplexing). 86 */ 87 typedef struct mbedtls_net_context 88 { 89 int fd; /**< The underlying file descriptor */ 90 } 91 mbedtls_net_context; 92 93 /** 94 * \brief Initialize a context 95 * Just makes the context ready to be used or freed safely. 96 * 97 * \param ctx Context to initialize 98 */ 99 void mbedtls_net_init( mbedtls_net_context *ctx ); 100 101 /** 102 * \brief Initiate a connection with host:port in the given protocol 103 * 104 * \param ctx Socket to use 105 * \param host Host to connect to 106 * \param port Port to connect to 107 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 108 * 109 * \return 0 if successful, or one of: 110 * MBEDTLS_ERR_NET_SOCKET_FAILED, 111 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 112 * MBEDTLS_ERR_NET_CONNECT_FAILED 113 * 114 * \note Sets the socket in connected mode even with UDP. 115 */ 116 int mbedtls_net_connect( mbedtls_net_context *ctx, const char *host, const char *port, int proto ); 117 118 /** 119 * \brief Create a receiving socket on bind_ip:port in the chosen 120 * protocol. If bind_ip == NULL, all interfaces are bound. 121 * 122 * \param ctx Socket to use 123 * \param bind_ip IP to bind to, can be NULL 124 * \param port Port number to use 125 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 126 * 127 * \return 0 if successful, or one of: 128 * MBEDTLS_ERR_NET_SOCKET_FAILED, 129 * MBEDTLS_ERR_NET_BIND_FAILED, 130 * MBEDTLS_ERR_NET_LISTEN_FAILED 131 * 132 * \note Regardless of the protocol, opens the sockets and binds it. 133 * In addition, make the socket listening if protocol is TCP. 134 */ 135 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto ); 136 137 /** 138 * \brief Accept a connection from a remote client 139 * 140 * \param bind_ctx Relevant socket 141 * \param client_ctx Will contain the connected client socket 142 * \param client_ip Will contain the client IP address, can be NULL 143 * \param buf_size Size of the client_ip buffer 144 * \param ip_len Will receive the size of the client IP written, 145 * can be NULL if client_ip is null 146 * 147 * \return 0 if successful, or 148 * MBEDTLS_ERR_NET_ACCEPT_FAILED, or 149 * MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, 150 * MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to 151 * non-blocking and accept() would block. 152 */ 153 int mbedtls_net_accept( mbedtls_net_context *bind_ctx, 154 mbedtls_net_context *client_ctx, 155 void *client_ip, size_t buf_size, size_t *ip_len ); 156 157 /** 158 * \brief Check and wait for the context to be ready for read/write 159 * 160 * \param ctx Socket to check 161 * \param rw Bitflag composed of MBEDTLS_NET_POLL_READ and 162 * MBEDTLS_NET_POLL_WRITE specifying the events 163 * to wait for: 164 * - If MBEDTLS_NET_POLL_READ is set, the function 165 * will return as soon as the net context is available 166 * for reading. 167 * - If MBEDTLS_NET_POLL_WRITE is set, the function 168 * will return as soon as the net context is available 169 * for writing. 170 * \param timeout Maximal amount of time to wait before returning, 171 * in milliseconds. If \c timeout is zero, the 172 * function returns immediately. If \c timeout is 173 * -1u, the function blocks potentially indefinitely. 174 * 175 * \return Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE 176 * on success or timeout, or a negative return code otherwise. 177 */ 178 int mbedtls_net_poll( mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout ); 179 180 /** 181 * \brief Set the socket blocking 182 * 183 * \param ctx Socket to set 184 * 185 * \return 0 if successful, or a non-zero error code 186 */ 187 int mbedtls_net_set_block( mbedtls_net_context *ctx ); 188 189 /** 190 * \brief Set the socket non-blocking 191 * 192 * \param ctx Socket to set 193 * 194 * \return 0 if successful, or a non-zero error code 195 */ 196 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx ); 197 198 /** 199 * \brief Portable usleep helper 200 * 201 * \param usec Amount of microseconds to sleep 202 * 203 * \note Real amount of time slept will not be less than 204 * select()'s timeout granularity (typically, 10ms). 205 */ 206 void mbedtls_net_usleep( unsigned long usec ); 207 208 /** 209 * \brief Read at most 'len' characters. If no error occurs, 210 * the actual amount read is returned. 211 * 212 * \param ctx Socket 213 * \param buf The buffer to write to 214 * \param len Maximum length of the buffer 215 * 216 * \return the number of bytes received, 217 * or a non-zero error code; with a non-blocking socket, 218 * MBEDTLS_ERR_SSL_WANT_READ indicates read() would block. 219 */ 220 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len ); 221 222 /** 223 * \brief Write at most 'len' characters. If no error occurs, 224 * the actual amount read is returned. 225 * 226 * \param ctx Socket 227 * \param buf The buffer to read from 228 * \param len The length of the buffer 229 * 230 * \return the number of bytes sent, 231 * or a non-zero error code; with a non-blocking socket, 232 * MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block. 233 */ 234 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len ); 235 236 /** 237 * \brief Read at most 'len' characters, blocking for at most 238 * 'timeout' seconds. If no error occurs, the actual amount 239 * read is returned. 240 * 241 * \param ctx Socket 242 * \param buf The buffer to write to 243 * \param len Maximum length of the buffer 244 * \param timeout Maximum number of milliseconds to wait for data 245 * 0 means no timeout (wait forever) 246 * 247 * \return the number of bytes received, 248 * or a non-zero error code: 249 * MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out, 250 * MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. 251 * 252 * \note This function will block (until data becomes available or 253 * timeout is reached) even if the socket is set to 254 * non-blocking. Handling timeouts with non-blocking reads 255 * requires a different strategy. 256 */ 257 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len, 258 uint32_t timeout ); 259 260 /** 261 * \brief Gracefully shutdown the connection and free associated data 262 * 263 * \param ctx The context to free 264 */ 265 void mbedtls_net_free( mbedtls_net_context *ctx ); 266 267 #ifdef __cplusplus 268 } 269 #endif 270 271 #endif /* net_sockets.h */ 272