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 The Mbed TLS Contributors 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 #ifndef MBEDTLS_NET_SOCKETS_H 39 #define MBEDTLS_NET_SOCKETS_H 40 41 #if !defined(MBEDTLS_CONFIG_FILE) 42 #include "mbedtls/config.h" 43 #else 44 #include MBEDTLS_CONFIG_FILE 45 #endif 46 47 #include "mbedtls/ssl.h" 48 49 #include <stddef.h> 50 #include <stdint.h> 51 52 #define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042 /**< Failed to open a socket. */ 53 #define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044 /**< The connection to the given server / port failed. */ 54 #define MBEDTLS_ERR_NET_BIND_FAILED -0x0046 /**< Binding of the socket failed. */ 55 #define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048 /**< Could not listen on the socket. */ 56 #define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A /**< Could not accept the incoming connection. */ 57 #define MBEDTLS_ERR_NET_RECV_FAILED -0x004C /**< Reading information from the socket failed. */ 58 #define MBEDTLS_ERR_NET_SEND_FAILED -0x004E /**< Sending information through the socket failed. */ 59 #define MBEDTLS_ERR_NET_CONN_RESET -0x0050 /**< Connection was reset by peer. */ 60 #define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052 /**< Failed to get an IP address for the given hostname. */ 61 #define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043 /**< Buffer is too small to hold the data. */ 62 #define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045 /**< The context is invalid, eg because it was free()ed. */ 63 #define MBEDTLS_ERR_NET_POLL_FAILED -0x0047 /**< Polling the net context failed. */ 64 #define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049 /**< Input invalid. */ 65 66 #define MBEDTLS_NET_LISTEN_BACKLOG 10 /**< The backlog that listen() should use. */ 67 68 #define MBEDTLS_NET_PROTO_TCP 0 /**< The TCP transport protocol */ 69 #define MBEDTLS_NET_PROTO_UDP 1 /**< The UDP transport protocol */ 70 71 #define MBEDTLS_NET_POLL_READ 1 /**< Used in \c mbedtls_net_poll to check for pending data */ 72 #define MBEDTLS_NET_POLL_WRITE 2 /**< Used in \c mbedtls_net_poll to check if write possible */ 73 74 #ifdef __cplusplus 75 extern "C" { 76 #endif 77 78 /** 79 * Wrapper type for sockets. 80 * 81 * Currently backed by just a file descriptor, but might be more in the future 82 * (eg two file descriptors for combined IPv4 + IPv6 support, or additional 83 * structures for hand-made UDP demultiplexing). 84 */ 85 typedef struct mbedtls_net_context 86 { 87 int fd; /**< The underlying file descriptor */ 88 } 89 mbedtls_net_context; 90 91 /** 92 * \brief Initialize a context 93 * Just makes the context ready to be used or freed safely. 94 * 95 * \param ctx Context to initialize 96 */ 97 void mbedtls_net_init( mbedtls_net_context *ctx ); 98 99 /** 100 * \brief Initiate a connection with host:port in the given protocol 101 * 102 * \param ctx Socket to use 103 * \param host Host to connect to 104 * \param port Port to connect to 105 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 106 * 107 * \return 0 if successful, or one of: 108 * MBEDTLS_ERR_NET_SOCKET_FAILED, 109 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 110 * MBEDTLS_ERR_NET_CONNECT_FAILED 111 * 112 * \note Sets the socket in connected mode even with UDP. 113 */ 114 int mbedtls_net_connect( mbedtls_net_context *ctx, const char *host, const char *port, int proto ); 115 116 /** 117 * \brief Create a receiving socket on bind_ip:port in the chosen 118 * protocol. If bind_ip == NULL, all interfaces are bound. 119 * 120 * \param ctx Socket to use 121 * \param bind_ip IP to bind to, can be NULL 122 * \param port Port number to use 123 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 124 * 125 * \return 0 if successful, or one of: 126 * MBEDTLS_ERR_NET_SOCKET_FAILED, 127 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 128 * MBEDTLS_ERR_NET_BIND_FAILED, 129 * MBEDTLS_ERR_NET_LISTEN_FAILED 130 * 131 * \note Regardless of the protocol, opens the sockets and binds it. 132 * In addition, make the socket listening if protocol is TCP. 133 */ 134 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto ); 135 136 /** 137 * \brief Accept a connection from a remote client 138 * 139 * \param bind_ctx Relevant socket 140 * \param client_ctx Will contain the connected client socket 141 * \param client_ip Will contain the client IP address, can be NULL 142 * \param buf_size Size of the client_ip buffer 143 * \param ip_len Will receive the size of the client IP written, 144 * can be NULL if client_ip is null 145 * 146 * \return 0 if successful, or 147 * MBEDTLS_ERR_NET_SOCKET_FAILED, 148 * MBEDTLS_ERR_NET_BIND_FAILED, 149 * MBEDTLS_ERR_NET_ACCEPT_FAILED, or 150 * MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, 151 * MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to 152 * non-blocking and accept() would block. 153 */ 154 int mbedtls_net_accept( mbedtls_net_context *bind_ctx, 155 mbedtls_net_context *client_ctx, 156 void *client_ip, size_t buf_size, size_t *ip_len ); 157 158 /** 159 * \brief Check and wait for the context to be ready for read/write 160 * 161 * \note The current implementation of this function uses 162 * select() and returns an error if the file descriptor 163 * is \c FD_SETSIZE or greater. 164 * 165 * \param ctx Socket to check 166 * \param rw Bitflag composed of MBEDTLS_NET_POLL_READ and 167 * MBEDTLS_NET_POLL_WRITE specifying the events 168 * to wait for: 169 * - If MBEDTLS_NET_POLL_READ is set, the function 170 * will return as soon as the net context is available 171 * for reading. 172 * - If MBEDTLS_NET_POLL_WRITE is set, the function 173 * will return as soon as the net context is available 174 * for writing. 175 * \param timeout Maximal amount of time to wait before returning, 176 * in milliseconds. If \c timeout is zero, the 177 * function returns immediately. If \c timeout is 178 * -1u, the function blocks potentially indefinitely. 179 * 180 * \return Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE 181 * on success or timeout, or a negative return code otherwise. 182 */ 183 int mbedtls_net_poll( mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout ); 184 185 /** 186 * \brief Set the socket blocking 187 * 188 * \param ctx Socket to set 189 * 190 * \return 0 if successful, or a non-zero error code 191 */ 192 int mbedtls_net_set_block( mbedtls_net_context *ctx ); 193 194 /** 195 * \brief Set the socket non-blocking 196 * 197 * \param ctx Socket to set 198 * 199 * \return 0 if successful, or a non-zero error code 200 */ 201 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx ); 202 203 /** 204 * \brief Portable usleep helper 205 * 206 * \param usec Amount of microseconds to sleep 207 * 208 * \note Real amount of time slept will not be less than 209 * select()'s timeout granularity (typically, 10ms). 210 */ 211 void mbedtls_net_usleep( unsigned long usec ); 212 213 /** 214 * \brief Read at most 'len' characters. If no error occurs, 215 * the actual amount read is returned. 216 * 217 * \param ctx Socket 218 * \param buf The buffer to write to 219 * \param len Maximum length of the buffer 220 * 221 * \return the number of bytes received, 222 * or a non-zero error code; with a non-blocking socket, 223 * MBEDTLS_ERR_SSL_WANT_READ indicates read() would block. 224 */ 225 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len ); 226 227 /** 228 * \brief Write at most 'len' characters. If no error occurs, 229 * the actual amount read is returned. 230 * 231 * \param ctx Socket 232 * \param buf The buffer to read from 233 * \param len The length of the buffer 234 * 235 * \return the number of bytes sent, 236 * or a non-zero error code; with a non-blocking socket, 237 * MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block. 238 */ 239 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len ); 240 241 /** 242 * \brief Read at most 'len' characters, blocking for at most 243 * 'timeout' seconds. If no error occurs, the actual amount 244 * read is returned. 245 * 246 * \note The current implementation of this function uses 247 * select() and returns an error if the file descriptor 248 * is \c FD_SETSIZE or greater. 249 * 250 * \param ctx Socket 251 * \param buf The buffer to write to 252 * \param len Maximum length of the buffer 253 * \param timeout Maximum number of milliseconds to wait for data 254 * 0 means no timeout (wait forever) 255 * 256 * \return The number of bytes received if successful. 257 * MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out. 258 * MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. 259 * Another negative error code (MBEDTLS_ERR_NET_xxx) 260 * for other failures. 261 * 262 * \note This function will block (until data becomes available or 263 * timeout is reached) even if the socket is set to 264 * non-blocking. Handling timeouts with non-blocking reads 265 * requires a different strategy. 266 */ 267 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len, 268 uint32_t timeout ); 269 270 /** 271 * \brief Closes down the connection and free associated data 272 * 273 * \param ctx The context to close 274 */ 275 void mbedtls_net_close( mbedtls_net_context *ctx ); 276 277 /** 278 * \brief Gracefully shutdown the connection and free associated data 279 * 280 * \param ctx The context to free 281 */ 282 void mbedtls_net_free( mbedtls_net_context *ctx ); 283 284 #ifdef __cplusplus 285 } 286 #endif 287 288 #endif /* net_sockets.h */ 289