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 /** Failed to open a socket. */ 53 #define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042 54 /** The connection to the given server / port failed. */ 55 #define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044 56 /** Binding of the socket failed. */ 57 #define MBEDTLS_ERR_NET_BIND_FAILED -0x0046 58 /** Could not listen on the socket. */ 59 #define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048 60 /** Could not accept the incoming connection. */ 61 #define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A 62 /** Reading information from the socket failed. */ 63 #define MBEDTLS_ERR_NET_RECV_FAILED -0x004C 64 /** Sending information through the socket failed. */ 65 #define MBEDTLS_ERR_NET_SEND_FAILED -0x004E 66 /** Connection was reset by peer. */ 67 #define MBEDTLS_ERR_NET_CONN_RESET -0x0050 68 /** Failed to get an IP address for the given hostname. */ 69 #define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052 70 /** Buffer is too small to hold the data. */ 71 #define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043 72 /** The context is invalid, eg because it was free()ed. */ 73 #define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045 74 /** Polling the net context failed. */ 75 #define MBEDTLS_ERR_NET_POLL_FAILED -0x0047 76 /** Input invalid. */ 77 #define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049 78 79 #define MBEDTLS_NET_LISTEN_BACKLOG 10 /**< The backlog that listen() should use. */ 80 81 #define MBEDTLS_NET_PROTO_TCP 0 /**< The TCP transport protocol */ 82 #define MBEDTLS_NET_PROTO_UDP 1 /**< The UDP transport protocol */ 83 84 #define MBEDTLS_NET_POLL_READ 1 /**< Used in \c mbedtls_net_poll to check for pending data */ 85 #define MBEDTLS_NET_POLL_WRITE 2 /**< Used in \c mbedtls_net_poll to check if write possible */ 86 87 #ifdef __cplusplus 88 extern "C" { 89 #endif 90 91 /** 92 * Wrapper type for sockets. 93 * 94 * Currently backed by just a file descriptor, but might be more in the future 95 * (eg two file descriptors for combined IPv4 + IPv6 support, or additional 96 * structures for hand-made UDP demultiplexing). 97 */ 98 typedef struct mbedtls_net_context 99 { 100 int fd; /**< The underlying file descriptor */ 101 } 102 mbedtls_net_context; 103 104 /** 105 * \brief Initialize a context 106 * Just makes the context ready to be used or freed safely. 107 * 108 * \param ctx Context to initialize 109 */ 110 void mbedtls_net_init( mbedtls_net_context *ctx ); 111 112 /** 113 * \brief Initiate a connection with host:port in the given protocol 114 * 115 * \param ctx Socket to use 116 * \param host Host to connect to 117 * \param port Port to connect to 118 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 119 * 120 * \return 0 if successful, or one of: 121 * MBEDTLS_ERR_NET_SOCKET_FAILED, 122 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 123 * MBEDTLS_ERR_NET_CONNECT_FAILED 124 * 125 * \note Sets the socket in connected mode even with UDP. 126 */ 127 int mbedtls_net_connect( mbedtls_net_context *ctx, const char *host, const char *port, int proto ); 128 129 /** 130 * \brief Create a receiving socket on bind_ip:port in the chosen 131 * protocol. If bind_ip == NULL, all interfaces are bound. 132 * 133 * \param ctx Socket to use 134 * \param bind_ip IP to bind to, can be NULL 135 * \param port Port number to use 136 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 137 * 138 * \return 0 if successful, or one of: 139 * MBEDTLS_ERR_NET_SOCKET_FAILED, 140 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 141 * MBEDTLS_ERR_NET_BIND_FAILED, 142 * MBEDTLS_ERR_NET_LISTEN_FAILED 143 * 144 * \note Regardless of the protocol, opens the sockets and binds it. 145 * In addition, make the socket listening if protocol is TCP. 146 */ 147 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto ); 148 149 /** 150 * \brief Accept a connection from a remote client 151 * 152 * \param bind_ctx Relevant socket 153 * \param client_ctx Will contain the connected client socket 154 * \param client_ip Will contain the client IP address, can be NULL 155 * \param buf_size Size of the client_ip buffer 156 * \param ip_len Will receive the size of the client IP written, 157 * can be NULL if client_ip is null 158 * 159 * \return 0 if successful, or 160 * MBEDTLS_ERR_NET_SOCKET_FAILED, 161 * MBEDTLS_ERR_NET_BIND_FAILED, 162 * MBEDTLS_ERR_NET_ACCEPT_FAILED, or 163 * MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, 164 * MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to 165 * non-blocking and accept() would block. 166 */ 167 int mbedtls_net_accept( mbedtls_net_context *bind_ctx, 168 mbedtls_net_context *client_ctx, 169 void *client_ip, size_t buf_size, size_t *ip_len ); 170 171 /** 172 * \brief Check and wait for the context to be ready for read/write 173 * 174 * \note The current implementation of this function uses 175 * select() and returns an error if the file descriptor 176 * is \c FD_SETSIZE or greater. 177 * 178 * \param ctx Socket to check 179 * \param rw Bitflag composed of MBEDTLS_NET_POLL_READ and 180 * MBEDTLS_NET_POLL_WRITE specifying the events 181 * to wait for: 182 * - If MBEDTLS_NET_POLL_READ is set, the function 183 * will return as soon as the net context is available 184 * for reading. 185 * - If MBEDTLS_NET_POLL_WRITE is set, the function 186 * will return as soon as the net context is available 187 * for writing. 188 * \param timeout Maximal amount of time to wait before returning, 189 * in milliseconds. If \c timeout is zero, the 190 * function returns immediately. If \c timeout is 191 * -1u, the function blocks potentially indefinitely. 192 * 193 * \return Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE 194 * on success or timeout, or a negative return code otherwise. 195 */ 196 int mbedtls_net_poll( mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout ); 197 198 /** 199 * \brief Set the socket blocking 200 * 201 * \param ctx Socket to set 202 * 203 * \return 0 if successful, or a non-zero error code 204 */ 205 int mbedtls_net_set_block( mbedtls_net_context *ctx ); 206 207 /** 208 * \brief Set the socket non-blocking 209 * 210 * \param ctx Socket to set 211 * 212 * \return 0 if successful, or a non-zero error code 213 */ 214 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx ); 215 216 /** 217 * \brief Portable usleep helper 218 * 219 * \param usec Amount of microseconds to sleep 220 * 221 * \note Real amount of time slept will not be less than 222 * select()'s timeout granularity (typically, 10ms). 223 */ 224 void mbedtls_net_usleep( unsigned long usec ); 225 226 /** 227 * \brief Read at most 'len' characters. If no error occurs, 228 * the actual amount read is returned. 229 * 230 * \param ctx Socket 231 * \param buf The buffer to write to 232 * \param len Maximum length of the buffer 233 * 234 * \return the number of bytes received, 235 * or a non-zero error code; with a non-blocking socket, 236 * MBEDTLS_ERR_SSL_WANT_READ indicates read() would block. 237 */ 238 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len ); 239 240 /** 241 * \brief Write at most 'len' characters. If no error occurs, 242 * the actual amount read is returned. 243 * 244 * \param ctx Socket 245 * \param buf The buffer to read from 246 * \param len The length of the buffer 247 * 248 * \return the number of bytes sent, 249 * or a non-zero error code; with a non-blocking socket, 250 * MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block. 251 */ 252 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len ); 253 254 /** 255 * \brief Read at most 'len' characters, blocking for at most 256 * 'timeout' seconds. If no error occurs, the actual amount 257 * read is returned. 258 * 259 * \note The current implementation of this function uses 260 * select() and returns an error if the file descriptor 261 * is \c FD_SETSIZE or greater. 262 * 263 * \param ctx Socket 264 * \param buf The buffer to write to 265 * \param len Maximum length of the buffer 266 * \param timeout Maximum number of milliseconds to wait for data 267 * 0 means no timeout (wait forever) 268 * 269 * \return The number of bytes received if successful. 270 * MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out. 271 * MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. 272 * Another negative error code (MBEDTLS_ERR_NET_xxx) 273 * for other failures. 274 * 275 * \note This function will block (until data becomes available or 276 * timeout is reached) even if the socket is set to 277 * non-blocking. Handling timeouts with non-blocking reads 278 * requires a different strategy. 279 */ 280 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len, 281 uint32_t timeout ); 282 283 /** 284 * \brief Closes down the connection and free associated data 285 * 286 * \param ctx The context to close 287 */ 288 void mbedtls_net_close( mbedtls_net_context *ctx ); 289 290 /** 291 * \brief Gracefully shutdown the connection and free associated data 292 * 293 * \param ctx The context to free 294 */ 295 void mbedtls_net_free( mbedtls_net_context *ctx ); 296 297 #ifdef __cplusplus 298 } 299 #endif 300 301 #endif /* net_sockets.h */ 302