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 #include "mbedtls/private_access.h" 41 42 #include "mbedtls/build_info.h" 43 44 #include "mbedtls/ssl.h" 45 46 #include <stddef.h> 47 #include <stdint.h> 48 49 /** Failed to open a socket. */ 50 #define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042 51 /** The connection to the given server / port failed. */ 52 #define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044 53 /** Binding of the socket failed. */ 54 #define MBEDTLS_ERR_NET_BIND_FAILED -0x0046 55 /** Could not listen on the socket. */ 56 #define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048 57 /** Could not accept the incoming connection. */ 58 #define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A 59 /** Reading information from the socket failed. */ 60 #define MBEDTLS_ERR_NET_RECV_FAILED -0x004C 61 /** Sending information through the socket failed. */ 62 #define MBEDTLS_ERR_NET_SEND_FAILED -0x004E 63 /** Connection was reset by peer. */ 64 #define MBEDTLS_ERR_NET_CONN_RESET -0x0050 65 /** Failed to get an IP address for the given hostname. */ 66 #define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052 67 /** Buffer is too small to hold the data. */ 68 #define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043 69 /** The context is invalid, eg because it was free()ed. */ 70 #define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045 71 /** Polling the net context failed. */ 72 #define MBEDTLS_ERR_NET_POLL_FAILED -0x0047 73 /** Input invalid. */ 74 #define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049 75 76 #define MBEDTLS_NET_LISTEN_BACKLOG 10 /**< The backlog that listen() should use. */ 77 78 #define MBEDTLS_NET_PROTO_TCP 0 /**< The TCP transport protocol */ 79 #define MBEDTLS_NET_PROTO_UDP 1 /**< The UDP transport protocol */ 80 81 #define MBEDTLS_NET_POLL_READ 1 /**< Used in \c mbedtls_net_poll to check for pending data */ 82 #define MBEDTLS_NET_POLL_WRITE 2 /**< Used in \c mbedtls_net_poll to check if write possible */ 83 84 #ifdef __cplusplus 85 extern "C" { 86 #endif 87 88 /** 89 * Wrapper type for sockets. 90 * 91 * Currently backed by just a file descriptor, but might be more in the future 92 * (eg two file descriptors for combined IPv4 + IPv6 support, or additional 93 * structures for hand-made UDP demultiplexing). 94 */ 95 typedef struct mbedtls_net_context { 96 /** The underlying file descriptor. 97 * 98 * This field is only guaranteed to be present on POSIX/Unix-like platforms. 99 * On other platforms, it may have a different type, have a different 100 * meaning, or be absent altogether. 101 */ 102 int fd; 103 } 104 mbedtls_net_context; 105 106 /** 107 * \brief Initialize a context 108 * Just makes the context ready to be used or freed safely. 109 * 110 * \param ctx Context to initialize 111 */ 112 void mbedtls_net_init(mbedtls_net_context *ctx); 113 114 /** 115 * \brief Initiate a connection with host:port in the given protocol 116 * 117 * \param ctx Socket to use 118 * \param host Host to connect to 119 * \param port Port to connect to 120 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 121 * 122 * \return 0 if successful, or one of: 123 * MBEDTLS_ERR_NET_SOCKET_FAILED, 124 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 125 * MBEDTLS_ERR_NET_CONNECT_FAILED 126 * 127 * \note Sets the socket in connected mode even with UDP. 128 */ 129 int mbedtls_net_connect(mbedtls_net_context *ctx, const char *host, const char *port, int proto); 130 131 /** 132 * \brief Create a receiving socket on bind_ip:port in the chosen 133 * protocol. If bind_ip == NULL, all interfaces are bound. 134 * 135 * \param ctx Socket to use 136 * \param bind_ip IP to bind to, can be NULL 137 * \param port Port number to use 138 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 139 * 140 * \return 0 if successful, or one of: 141 * MBEDTLS_ERR_NET_SOCKET_FAILED, 142 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 143 * MBEDTLS_ERR_NET_BIND_FAILED, 144 * MBEDTLS_ERR_NET_LISTEN_FAILED 145 * 146 * \note Regardless of the protocol, opens the sockets and binds it. 147 * In addition, make the socket listening if protocol is TCP. 148 */ 149 int mbedtls_net_bind(mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto); 150 151 /** 152 * \brief Accept a connection from a remote client 153 * 154 * \param bind_ctx Relevant socket 155 * \param client_ctx Will contain the connected client socket 156 * \param client_ip Will contain the client IP address, can be NULL 157 * \param buf_size Size of the client_ip buffer 158 * \param ip_len Will receive the size of the client IP written, 159 * can be NULL if client_ip is null 160 * 161 * \return 0 if successful, or 162 * MBEDTLS_ERR_NET_SOCKET_FAILED, 163 * MBEDTLS_ERR_NET_BIND_FAILED, 164 * MBEDTLS_ERR_NET_ACCEPT_FAILED, or 165 * MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, 166 * MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to 167 * non-blocking and accept() would block. 168 */ 169 int mbedtls_net_accept(mbedtls_net_context *bind_ctx, 170 mbedtls_net_context *client_ctx, 171 void *client_ip, size_t buf_size, size_t *ip_len); 172 173 /** 174 * \brief Check and wait for the context to be ready for read/write 175 * 176 * \note The current implementation of this function uses 177 * select() and returns an error if the file descriptor 178 * is \c FD_SETSIZE or greater. 179 * 180 * \param ctx Socket to check 181 * \param rw Bitflag composed of MBEDTLS_NET_POLL_READ and 182 * MBEDTLS_NET_POLL_WRITE specifying the events 183 * to wait for: 184 * - If MBEDTLS_NET_POLL_READ is set, the function 185 * will return as soon as the net context is available 186 * for reading. 187 * - If MBEDTLS_NET_POLL_WRITE is set, the function 188 * will return as soon as the net context is available 189 * for writing. 190 * \param timeout Maximal amount of time to wait before returning, 191 * in milliseconds. If \c timeout is zero, the 192 * function returns immediately. If \c timeout is 193 * -1u, the function blocks potentially indefinitely. 194 * 195 * \return Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE 196 * on success or timeout, or a negative return code otherwise. 197 */ 198 int mbedtls_net_poll(mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout); 199 200 /** 201 * \brief Set the socket blocking 202 * 203 * \param ctx Socket to set 204 * 205 * \return 0 if successful, or a non-zero error code 206 */ 207 int mbedtls_net_set_block(mbedtls_net_context *ctx); 208 209 /** 210 * \brief Set the socket non-blocking 211 * 212 * \param ctx Socket to set 213 * 214 * \return 0 if successful, or a non-zero error code 215 */ 216 int mbedtls_net_set_nonblock(mbedtls_net_context *ctx); 217 218 /** 219 * \brief Portable usleep helper 220 * 221 * \param usec Amount of microseconds to sleep 222 * 223 * \note Real amount of time slept will not be less than 224 * select()'s timeout granularity (typically, 10ms). 225 */ 226 void mbedtls_net_usleep(unsigned long usec); 227 228 /** 229 * \brief Read at most 'len' characters. If no error occurs, 230 * the actual amount read is returned. 231 * 232 * \param ctx Socket 233 * \param buf The buffer to write to 234 * \param len Maximum length of the buffer 235 * 236 * \return the number of bytes received, 237 * or a non-zero error code; with a non-blocking socket, 238 * MBEDTLS_ERR_SSL_WANT_READ indicates read() would block. 239 */ 240 int mbedtls_net_recv(void *ctx, unsigned char *buf, size_t len); 241 242 /** 243 * \brief Write at most 'len' characters. If no error occurs, 244 * the actual amount read is returned. 245 * 246 * \param ctx Socket 247 * \param buf The buffer to read from 248 * \param len The length of the buffer 249 * 250 * \return the number of bytes sent, 251 * or a non-zero error code; with a non-blocking socket, 252 * MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block. 253 */ 254 int mbedtls_net_send(void *ctx, const unsigned char *buf, size_t len); 255 256 /** 257 * \brief Read at most 'len' characters, blocking for at most 258 * 'timeout' seconds. If no error occurs, the actual amount 259 * read is returned. 260 * 261 * \note The current implementation of this function uses 262 * select() and returns an error if the file descriptor 263 * is \c FD_SETSIZE or greater. 264 * 265 * \param ctx Socket 266 * \param buf The buffer to write to 267 * \param len Maximum length of the buffer 268 * \param timeout Maximum number of milliseconds to wait for data 269 * 0 means no timeout (wait forever) 270 * 271 * \return The number of bytes received if successful. 272 * MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out. 273 * MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. 274 * Another negative error code (MBEDTLS_ERR_NET_xxx) 275 * for other failures. 276 * 277 * \note This function will block (until data becomes available or 278 * timeout is reached) even if the socket is set to 279 * non-blocking. Handling timeouts with non-blocking reads 280 * requires a different strategy. 281 */ 282 int mbedtls_net_recv_timeout(void *ctx, unsigned char *buf, size_t len, 283 uint32_t timeout); 284 285 /** 286 * \brief Closes down the connection and free associated data 287 * 288 * \param ctx The context to close 289 */ 290 void mbedtls_net_close(mbedtls_net_context *ctx); 291 292 /** 293 * \brief Gracefully shutdown the connection and free associated data 294 * 295 * \param ctx The context to free 296 */ 297 void mbedtls_net_free(mbedtls_net_context *ctx); 298 299 #ifdef __cplusplus 300 } 301 #endif 302 303 #endif /* net_sockets.h */ 304
