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 OR GPL-2.0-or-later 25 * 26 * This file is provided under the Apache License 2.0, or the 27 * GNU General Public License v2.0 or later. 28 * 29 * ********** 30 * Apache License 2.0: 31 * 32 * Licensed under the Apache License, Version 2.0 (the "License"); you may 33 * not use this file except in compliance with the License. 34 * You may obtain a copy of the License at 35 * 36 * http://www.apache.org/licenses/LICENSE-2.0 37 * 38 * Unless required by applicable law or agreed to in writing, software 39 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 40 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 41 * See the License for the specific language governing permissions and 42 * limitations under the License. 43 * 44 * ********** 45 * 46 * ********** 47 * GNU General Public License v2.0 or later: 48 * 49 * This program is free software; you can redistribute it and/or modify 50 * it under the terms of the GNU General Public License as published by 51 * the Free Software Foundation; either version 2 of the License, or 52 * (at your option) any later version. 53 * 54 * This program is distributed in the hope that it will be useful, 55 * but WITHOUT ANY WARRANTY; without even the implied warranty of 56 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 57 * GNU General Public License for more details. 58 * 59 * You should have received a copy of the GNU General Public License along 60 * with this program; if not, write to the Free Software Foundation, Inc., 61 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 62 * 63 * ********** 64 */ 65 #ifndef MBEDTLS_NET_SOCKETS_H 66 #define MBEDTLS_NET_SOCKETS_H 67 68 #if !defined(MBEDTLS_CONFIG_FILE) 69 #include "config.h" 70 #else 71 #include MBEDTLS_CONFIG_FILE 72 #endif 73 74 #include "ssl.h" 75 76 #include <stddef.h> 77 #include <stdint.h> 78 79 #define MBEDTLS_ERR_NET_SOCKET_FAILED -0x0042 /**< Failed to open a socket. */ 80 #define MBEDTLS_ERR_NET_CONNECT_FAILED -0x0044 /**< The connection to the given server / port failed. */ 81 #define MBEDTLS_ERR_NET_BIND_FAILED -0x0046 /**< Binding of the socket failed. */ 82 #define MBEDTLS_ERR_NET_LISTEN_FAILED -0x0048 /**< Could not listen on the socket. */ 83 #define MBEDTLS_ERR_NET_ACCEPT_FAILED -0x004A /**< Could not accept the incoming connection. */ 84 #define MBEDTLS_ERR_NET_RECV_FAILED -0x004C /**< Reading information from the socket failed. */ 85 #define MBEDTLS_ERR_NET_SEND_FAILED -0x004E /**< Sending information through the socket failed. */ 86 #define MBEDTLS_ERR_NET_CONN_RESET -0x0050 /**< Connection was reset by peer. */ 87 #define MBEDTLS_ERR_NET_UNKNOWN_HOST -0x0052 /**< Failed to get an IP address for the given hostname. */ 88 #define MBEDTLS_ERR_NET_BUFFER_TOO_SMALL -0x0043 /**< Buffer is too small to hold the data. */ 89 #define MBEDTLS_ERR_NET_INVALID_CONTEXT -0x0045 /**< The context is invalid, eg because it was free()ed. */ 90 #define MBEDTLS_ERR_NET_POLL_FAILED -0x0047 /**< Polling the net context failed. */ 91 #define MBEDTLS_ERR_NET_BAD_INPUT_DATA -0x0049 /**< Input invalid. */ 92 93 #define MBEDTLS_NET_LISTEN_BACKLOG 10 /**< The backlog that listen() should use. */ 94 95 #define MBEDTLS_NET_PROTO_TCP 0 /**< The TCP transport protocol */ 96 #define MBEDTLS_NET_PROTO_UDP 1 /**< The UDP transport protocol */ 97 98 #define MBEDTLS_NET_POLL_READ 1 /**< Used in \c mbedtls_net_poll to check for pending data */ 99 #define MBEDTLS_NET_POLL_WRITE 2 /**< Used in \c mbedtls_net_poll to check if write possible */ 100 101 #ifdef __cplusplus 102 extern "C" { 103 #endif 104 105 /** 106 * Wrapper type for sockets. 107 * 108 * Currently backed by just a file descriptor, but might be more in the future 109 * (eg two file descriptors for combined IPv4 + IPv6 support, or additional 110 * structures for hand-made UDP demultiplexing). 111 */ 112 typedef struct mbedtls_net_context 113 { 114 int fd; /**< The underlying file descriptor */ 115 } 116 mbedtls_net_context; 117 118 /** 119 * \brief Initialize a context 120 * Just makes the context ready to be used or freed safely. 121 * 122 * \param ctx Context to initialize 123 */ 124 void mbedtls_net_init( mbedtls_net_context *ctx ); 125 126 /** 127 * \brief Initiate a connection with host:port in the given protocol 128 * 129 * \param ctx Socket to use 130 * \param host Host to connect to 131 * \param port Port to connect to 132 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 133 * 134 * \return 0 if successful, or one of: 135 * MBEDTLS_ERR_NET_SOCKET_FAILED, 136 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 137 * MBEDTLS_ERR_NET_CONNECT_FAILED 138 * 139 * \note Sets the socket in connected mode even with UDP. 140 */ 141 int mbedtls_net_connect( mbedtls_net_context *ctx, const char *host, const char *port, int proto ); 142 143 /** 144 * \brief Create a receiving socket on bind_ip:port in the chosen 145 * protocol. If bind_ip == NULL, all interfaces are bound. 146 * 147 * \param ctx Socket to use 148 * \param bind_ip IP to bind to, can be NULL 149 * \param port Port number to use 150 * \param proto Protocol: MBEDTLS_NET_PROTO_TCP or MBEDTLS_NET_PROTO_UDP 151 * 152 * \return 0 if successful, or one of: 153 * MBEDTLS_ERR_NET_SOCKET_FAILED, 154 * MBEDTLS_ERR_NET_UNKNOWN_HOST, 155 * MBEDTLS_ERR_NET_BIND_FAILED, 156 * MBEDTLS_ERR_NET_LISTEN_FAILED 157 * 158 * \note Regardless of the protocol, opens the sockets and binds it. 159 * In addition, make the socket listening if protocol is TCP. 160 */ 161 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto ); 162 163 /** 164 * \brief Accept a connection from a remote client 165 * 166 * \param bind_ctx Relevant socket 167 * \param client_ctx Will contain the connected client socket 168 * \param client_ip Will contain the client IP address, can be NULL 169 * \param buf_size Size of the client_ip buffer 170 * \param ip_len Will receive the size of the client IP written, 171 * can be NULL if client_ip is null 172 * 173 * \return 0 if successful, or 174 * MBEDTLS_ERR_NET_SOCKET_FAILED, 175 * MBEDTLS_ERR_NET_BIND_FAILED, 176 * MBEDTLS_ERR_NET_ACCEPT_FAILED, or 177 * MBEDTLS_ERR_NET_BUFFER_TOO_SMALL if buf_size is too small, 178 * MBEDTLS_ERR_SSL_WANT_READ if bind_fd was set to 179 * non-blocking and accept() would block. 180 */ 181 int mbedtls_net_accept( mbedtls_net_context *bind_ctx, 182 mbedtls_net_context *client_ctx, 183 void *client_ip, size_t buf_size, size_t *ip_len ); 184 185 /** 186 * \brief Check and wait for the context to be ready for read/write 187 * 188 * \note The current implementation of this function uses 189 * select() and returns an error if the file descriptor 190 * is \c FD_SETSIZE or greater. 191 * 192 * \param ctx Socket to check 193 * \param rw Bitflag composed of MBEDTLS_NET_POLL_READ and 194 * MBEDTLS_NET_POLL_WRITE specifying the events 195 * to wait for: 196 * - If MBEDTLS_NET_POLL_READ is set, the function 197 * will return as soon as the net context is available 198 * for reading. 199 * - If MBEDTLS_NET_POLL_WRITE is set, the function 200 * will return as soon as the net context is available 201 * for writing. 202 * \param timeout Maximal amount of time to wait before returning, 203 * in milliseconds. If \c timeout is zero, the 204 * function returns immediately. If \c timeout is 205 * -1u, the function blocks potentially indefinitely. 206 * 207 * \return Bitmask composed of MBEDTLS_NET_POLL_READ/WRITE 208 * on success or timeout, or a negative return code otherwise. 209 */ 210 int mbedtls_net_poll( mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout ); 211 212 /** 213 * \brief Set the socket blocking 214 * 215 * \param ctx Socket to set 216 * 217 * \return 0 if successful, or a non-zero error code 218 */ 219 int mbedtls_net_set_block( mbedtls_net_context *ctx ); 220 221 /** 222 * \brief Set the socket non-blocking 223 * 224 * \param ctx Socket to set 225 * 226 * \return 0 if successful, or a non-zero error code 227 */ 228 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx ); 229 230 /** 231 * \brief Portable usleep helper 232 * 233 * \param usec Amount of microseconds to sleep 234 * 235 * \note Real amount of time slept will not be less than 236 * select()'s timeout granularity (typically, 10ms). 237 */ 238 void mbedtls_net_usleep( unsigned long usec ); 239 240 /** 241 * \brief Read 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 write to 246 * \param len Maximum length of the buffer 247 * 248 * \return the number of bytes received, 249 * or a non-zero error code; with a non-blocking socket, 250 * MBEDTLS_ERR_SSL_WANT_READ indicates read() would block. 251 */ 252 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len ); 253 254 /** 255 * \brief Write at most 'len' characters. If no error occurs, 256 * the actual amount read is returned. 257 * 258 * \param ctx Socket 259 * \param buf The buffer to read from 260 * \param len The length of the buffer 261 * 262 * \return the number of bytes sent, 263 * or a non-zero error code; with a non-blocking socket, 264 * MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block. 265 */ 266 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len ); 267 268 /** 269 * \brief Read at most 'len' characters, blocking for at most 270 * 'timeout' seconds. If no error occurs, the actual amount 271 * read is returned. 272 * 273 * \note The current implementation of this function uses 274 * select() and returns an error if the file descriptor 275 * is \c FD_SETSIZE or greater. 276 * 277 * \param ctx Socket 278 * \param buf The buffer to write to 279 * \param len Maximum length of the buffer 280 * \param timeout Maximum number of milliseconds to wait for data 281 * 0 means no timeout (wait forever) 282 * 283 * \return The number of bytes received if successful. 284 * MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out. 285 * MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal. 286 * Another negative error code (MBEDTLS_ERR_NET_xxx) 287 * for other failures. 288 * 289 * \note This function will block (until data becomes available or 290 * timeout is reached) even if the socket is set to 291 * non-blocking. Handling timeouts with non-blocking reads 292 * requires a different strategy. 293 */ 294 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len, 295 uint32_t timeout ); 296 297 /** 298 * \brief Gracefully shutdown the connection and free associated data 299 * 300 * \param ctx The context to free 301 */ 302 void mbedtls_net_free( mbedtls_net_context *ctx ); 303 304 #ifdef __cplusplus 305 } 306 #endif 307 308 #endif /* net_sockets.h */ 309