net_sockets.h 11 KB

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