library/net_sockets.c - mirror/mbed-tls - TrustedFirmware Git Browser

 /*
  *  TCP/IP or UDP/IP networking functions
  *
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
  *  not use this file except in compliance with the License.
  *  You may obtain a copy of the License at
  *
  *  http://www.apache.org/licenses/LICENSE-2.0
  *
  *  Unless required by applicable law or agreed to in writing, software
  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */

 /* Enable definition of getaddrinfo() even when compiling with -std=c99. Must
  * be set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
  * Harmless on other platforms. */
 #ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200112L
 #endif
 #ifndef _XOPEN_SOURCE
 #define _XOPEN_SOURCE 600 /* sockaddr_storage */
 #endif

 #include "common.h"

 #if defined(MBEDTLS_NET_C)

 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
     !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
     !defined(__HAIKU__) && !defined(__midipix__)
 #error "This module only works on Unix and Windows, see MBEDTLS_NET_C in mbedtls_config.h"
 #endif

 #include "mbedtls/platform.h"

 #include "mbedtls/net_sockets.h"
 #include "mbedtls/error.h"

 #include <string.h>

 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)

 #define IS_EINTR(ret) ((ret) == WSAEINTR)

 #if !defined(_WIN32_WINNT)
 /* Enables getaddrinfo() & Co */
 #define _WIN32_WINNT 0x0501
 #endif

 #include <ws2tcpip.h>

 #include <winsock2.h>
 #include <windows.h>
 #if (_WIN32_WINNT < 0x0501)
 #include <wspiapi.h>
 #endif

 #if defined(_MSC_VER)
 #if defined(_WIN32_WCE)
 #pragma comment( lib, "ws2.lib" )
 #else
 #pragma comment( lib, "ws2_32.lib" )
 #endif
 #endif /* _MSC_VER */

 #define read(fd, buf, len)        recv(fd, (char *) (buf), (int) (len), 0)
 #define write(fd, buf, len)       send(fd, (char *) (buf), (int) (len), 0)
 #define close(fd)               closesocket(fd)

 static int wsa_init_done = 0;

 #else /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */

 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <sys/time.h>
 #include <unistd.h>
 #include <signal.h>
 #include <fcntl.h>
 #include <netdb.h>
 #include <errno.h>

 #define IS_EINTR(ret) ((ret) == EINTR)

 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */

 /* Some MS functions want int and MSVC warns if we pass size_t,
  * but the standard functions use socklen_t, so cast only for MSVC */
 #if defined(_MSC_VER)
 #define MSVC_INT_CAST   (int)
 #else
 #define MSVC_INT_CAST
 #endif

 #include <stdio.h>

 #if defined(MBEDTLS_HAVE_TIME)
 #include <time.h>
 #endif

 #include <stdint.h>

 /*
  * Prepare for using the sockets interface
  */
 static int net_prepare(void)
 {
 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)
     WSADATA wsaData;

     if (wsa_init_done == 0) {
         if (WSAStartup(MAKEWORD(2, 0), &wsaData) != 0) {
             return MBEDTLS_ERR_NET_SOCKET_FAILED;
         }

         wsa_init_done = 1;
     }
 #else
 #if !defined(EFIX64) && !defined(EFI32)
     signal(SIGPIPE, SIG_IGN);
 #endif
 #endif
     return 0;
 }

 /*
  * Return 0 if the file descriptor is valid, an error otherwise.
  * If for_select != 0, check whether the file descriptor is within the range
  * allowed for fd_set used for the FD_xxx macros and the select() function.
  */
 static int check_fd(int fd, int for_select)
 {
     if (fd < 0) {
         return MBEDTLS_ERR_NET_INVALID_CONTEXT;
     }

 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)
     (void) for_select;
 #else
     /* A limitation of select() is that it only works with file descriptors
      * that are strictly less than FD_SETSIZE. This is a limitation of the
      * fd_set type. Error out early, because attempting to call FD_SET on a
      * large file descriptor is a buffer overflow on typical platforms. */
     if (for_select && fd >= FD_SETSIZE) {
         return MBEDTLS_ERR_NET_POLL_FAILED;
     }
 #endif

     return 0;
 }

 /*
  * Initialize a context
  */
 void mbedtls_net_init(mbedtls_net_context *ctx)
 {
     ctx->fd = -1;
 }

 /*
  * Initiate a TCP connection with host:port and the given protocol
  */
 int mbedtls_net_connect(mbedtls_net_context *ctx, const char *host,
                         const char *port, int proto)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     struct addrinfo hints, *addr_list, *cur;

     if ((ret = net_prepare()) != 0) {
         return ret;
     }

     /* Do name resolution with both IPv6 and IPv4 */
     memset(&hints, 0, sizeof(hints));
     hints.ai_family = AF_UNSPEC;
     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;

     if (getaddrinfo(host, port, &hints, &addr_list) != 0) {
         return MBEDTLS_ERR_NET_UNKNOWN_HOST;
     }

     /* Try the sockaddrs until a connection succeeds */
     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
     for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
         ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
                                cur->ai_protocol);
         if (ctx->fd < 0) {
             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
             continue;
         }

         if (connect(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) == 0) {
             ret = 0;
             break;
         }

         close(ctx->fd);
         ret = MBEDTLS_ERR_NET_CONNECT_FAILED;
     }

     freeaddrinfo(addr_list);

     return ret;
 }

 /*
  * Create a listening socket on bind_ip:port
  */
 int mbedtls_net_bind(mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto)
 {
     int n, ret;
     struct addrinfo hints, *addr_list, *cur;

     if ((ret = net_prepare()) != 0) {
         return ret;
     }

     /* Bind to IPv6 and/or IPv4, but only in the desired protocol */
     memset(&hints, 0, sizeof(hints));
     hints.ai_family = AF_UNSPEC;
     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
     if (bind_ip == NULL) {
         hints.ai_flags = AI_PASSIVE;
     }

     if (getaddrinfo(bind_ip, port, &hints, &addr_list) != 0) {
         return MBEDTLS_ERR_NET_UNKNOWN_HOST;
     }

     /* Try the sockaddrs until a binding succeeds */
     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
     for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
         ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
                                cur->ai_protocol);
         if (ctx->fd < 0) {
             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
             continue;
         }

         n = 1;
         if (setsockopt(ctx->fd, SOL_SOCKET, SO_REUSEADDR,
                        (const char *) &n, sizeof(n)) != 0) {
             close(ctx->fd);
             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
             continue;
         }

         if (bind(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) != 0) {
             close(ctx->fd);
             ret = MBEDTLS_ERR_NET_BIND_FAILED;
             continue;
         }

         /* Listen only makes sense for TCP */
         if (proto == MBEDTLS_NET_PROTO_TCP) {
             if (listen(ctx->fd, MBEDTLS_NET_LISTEN_BACKLOG) != 0) {
                 close(ctx->fd);
                 ret = MBEDTLS_ERR_NET_LISTEN_FAILED;
                 continue;
             }
         }

         /* Bind was successful */
         ret = 0;
         break;
     }

     freeaddrinfo(addr_list);

     return ret;

 }

 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)
 /*
  * Check if the requested operation would be blocking on a non-blocking socket
  * and thus 'failed' with a negative return value.
  */
 static int net_would_block(const mbedtls_net_context *ctx)
 {
     ((void) ctx);
     return WSAGetLastError() == WSAEWOULDBLOCK;
 }
 #else
 /*
  * Check if the requested operation would be blocking on a non-blocking socket
  * and thus 'failed' with a negative return value.
  *
  * Note: on a blocking socket this function always returns 0!
  */
 static int net_would_block(const mbedtls_net_context *ctx)
 {
     int err = errno;

     /*
      * Never return 'WOULD BLOCK' on a blocking socket
      */
     if ((fcntl(ctx->fd, F_GETFL) & O_NONBLOCK) != O_NONBLOCK) {
         errno = err;
         return 0;
     }

     switch (errno = err) {
 #if defined EAGAIN
         case EAGAIN:
 #endif
 #if defined EWOULDBLOCK && EWOULDBLOCK != EAGAIN
         case EWOULDBLOCK:
 #endif
     return 1;
     }
     return 0;
 }
 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */

 /*
  * Accept a connection from a remote client
  */
 int mbedtls_net_accept(mbedtls_net_context *bind_ctx,
                        mbedtls_net_context *client_ctx,
                        void *client_ip, size_t buf_size, size_t *ip_len)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int type;

     struct sockaddr_storage client_addr;

 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
     defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t) || \
     defined(socklen_t) || (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L)
     socklen_t n = (socklen_t) sizeof(client_addr);
     socklen_t type_len = (socklen_t) sizeof(type);
 #else
     int n = (int) sizeof(client_addr);
     int type_len = (int) sizeof(type);
 #endif

     /* Is this a TCP or UDP socket? */
     if (getsockopt(bind_ctx->fd, SOL_SOCKET, SO_TYPE,
                    (void *) &type, &type_len) != 0 ||
         (type != SOCK_STREAM && type != SOCK_DGRAM)) {
         return MBEDTLS_ERR_NET_ACCEPT_FAILED;
     }

     if (type == SOCK_STREAM) {
         /* TCP: actual accept() */
         ret = client_ctx->fd = (int) accept(bind_ctx->fd,
                                             (struct sockaddr *) &client_addr, &n);
     } else {
         /* UDP: wait for a message, but keep it in the queue */
         char buf[1] = { 0 };

         ret = (int) recvfrom(bind_ctx->fd, buf, sizeof(buf), MSG_PEEK,
                              (struct sockaddr *) &client_addr, &n);

 #if defined(_WIN32)
         if (ret == SOCKET_ERROR &&
             WSAGetLastError() == WSAEMSGSIZE) {
             /* We know buf is too small, thanks, just peeking here */
             ret = 0;
         }
 #endif
     }

     if (ret < 0) {
         if (net_would_block(bind_ctx) != 0) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }

         return MBEDTLS_ERR_NET_ACCEPT_FAILED;
     }

     /* UDP: hijack the listening socket to communicate with the client,
      * then bind a new socket to accept new connections */
     if (type != SOCK_STREAM) {
         struct sockaddr_storage local_addr;
         int one = 1;

         if (connect(bind_ctx->fd, (struct sockaddr *) &client_addr, n) != 0) {
             return MBEDTLS_ERR_NET_ACCEPT_FAILED;
         }

         client_ctx->fd = bind_ctx->fd;
         bind_ctx->fd   = -1; /* In case we exit early */

         n = sizeof(struct sockaddr_storage);
         if (getsockname(client_ctx->fd,
                         (struct sockaddr *) &local_addr, &n) != 0 ||
             (bind_ctx->fd = (int) socket(local_addr.ss_family,
                                          SOCK_DGRAM, IPPROTO_UDP)) < 0 ||
             setsockopt(bind_ctx->fd, SOL_SOCKET, SO_REUSEADDR,
                        (const char *) &one, sizeof(one)) != 0) {
             return MBEDTLS_ERR_NET_SOCKET_FAILED;
         }

         if (bind(bind_ctx->fd, (struct sockaddr *) &local_addr, n) != 0) {
             return MBEDTLS_ERR_NET_BIND_FAILED;
         }
     }

     if (client_ip != NULL) {
         if (client_addr.ss_family == AF_INET) {
             struct sockaddr_in *addr4 = (struct sockaddr_in *) &client_addr;
             *ip_len = sizeof(addr4->sin_addr.s_addr);

             if (buf_size < *ip_len) {
                 return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
             }

             memcpy(client_ip, &addr4->sin_addr.s_addr, *ip_len);
         } else {
             struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &client_addr;
             *ip_len = sizeof(addr6->sin6_addr.s6_addr);

             if (buf_size < *ip_len) {
                 return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
             }

             memcpy(client_ip, &addr6->sin6_addr.s6_addr, *ip_len);
         }
     }

     return 0;
 }

 /*
  * Set the socket blocking or non-blocking
  */
 int mbedtls_net_set_block(mbedtls_net_context *ctx)
 {
 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)
     u_long n = 0;
     return ioctlsocket(ctx->fd, FIONBIO, &n);
 #else
     return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) & ~O_NONBLOCK);
 #endif
 }

 int mbedtls_net_set_nonblock(mbedtls_net_context *ctx)
 {
 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
     !defined(EFI32)
     u_long n = 1;
     return ioctlsocket(ctx->fd, FIONBIO, &n);
 #else
     return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) | O_NONBLOCK);
 #endif
 }

 /*
  * Check if data is available on the socket
  */

 int mbedtls_net_poll(mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     struct timeval tv;

     fd_set read_fds;
     fd_set write_fds;

     int fd = ctx->fd;

     ret = check_fd(fd, 1);
     if (ret != 0) {
         return ret;
     }

 #if defined(__has_feature)
 #if __has_feature(memory_sanitizer)
     /* Ensure that memory sanitizers consider read_fds and write_fds as
      * initialized even on platforms such as Glibc/x86_64 where FD_ZERO
      * is implemented in assembly. */
     memset(&read_fds, 0, sizeof(read_fds));
     memset(&write_fds, 0, sizeof(write_fds));
 #endif
 #endif

     FD_ZERO(&read_fds);
     if (rw & MBEDTLS_NET_POLL_READ) {
         rw &= ~MBEDTLS_NET_POLL_READ;
         FD_SET(fd, &read_fds);
     }

     FD_ZERO(&write_fds);
     if (rw & MBEDTLS_NET_POLL_WRITE) {
         rw &= ~MBEDTLS_NET_POLL_WRITE;
         FD_SET(fd, &write_fds);
     }

     if (rw != 0) {
         return MBEDTLS_ERR_NET_BAD_INPUT_DATA;
     }

     tv.tv_sec  = timeout / 1000;
     tv.tv_usec = (timeout % 1000) * 1000;

     do {
         ret = select(fd + 1, &read_fds, &write_fds, NULL,
                      timeout == (uint32_t) -1 ? NULL : &tv);
     } while (IS_EINTR(ret));

     if (ret < 0) {
         return MBEDTLS_ERR_NET_POLL_FAILED;
     }

     ret = 0;
     if (FD_ISSET(fd, &read_fds)) {
         ret |= MBEDTLS_NET_POLL_READ;
     }
     if (FD_ISSET(fd, &write_fds)) {
         ret |= MBEDTLS_NET_POLL_WRITE;
     }

     return ret;
 }

 /*
  * Portable usleep helper
  */
 void mbedtls_net_usleep(unsigned long usec)
 {
 #if defined(_WIN32)
     Sleep((usec + 999) / 1000);
 #else
     struct timeval tv;
     tv.tv_sec  = usec / 1000000;
 #if defined(__unix__) || defined(__unix) || \
     (defined(__APPLE__) && defined(__MACH__))
     tv.tv_usec = (suseconds_t) usec % 1000000;
 #else
     tv.tv_usec = usec % 1000000;
 #endif
     select(0, NULL, NULL, NULL, &tv);
 #endif
 }

 /*
  * Read at most 'len' characters
  */
 int mbedtls_net_recv(void *ctx, unsigned char *buf, size_t len)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int fd = ((mbedtls_net_context *) ctx)->fd;

     ret = check_fd(fd, 0);
     if (ret != 0) {
         return ret;
     }

     ret = (int) read(fd, buf, len);

     if (ret < 0) {
         if (net_would_block(ctx) != 0) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }

 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
         !defined(EFI32)
         if (WSAGetLastError() == WSAECONNRESET) {
             return MBEDTLS_ERR_NET_CONN_RESET;
         }
 #else
         if (errno == EPIPE || errno == ECONNRESET) {
             return MBEDTLS_ERR_NET_CONN_RESET;
         }

         if (errno == EINTR) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }
 #endif

         return MBEDTLS_ERR_NET_RECV_FAILED;
     }

     return ret;
 }

 /*
  * Read at most 'len' characters, blocking for at most 'timeout' ms
  */
 int mbedtls_net_recv_timeout(void *ctx, unsigned char *buf,
                              size_t len, uint32_t timeout)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     struct timeval tv;
     fd_set read_fds;
     int fd = ((mbedtls_net_context *) ctx)->fd;

     ret = check_fd(fd, 1);
     if (ret != 0) {
         return ret;
     }

     FD_ZERO(&read_fds);
     FD_SET(fd, &read_fds);

     tv.tv_sec  = timeout / 1000;
     tv.tv_usec = (timeout % 1000) * 1000;

     ret = select(fd + 1, &read_fds, NULL, NULL, timeout == 0 ? NULL : &tv);

     /* Zero fds ready means we timed out */
     if (ret == 0) {
         return MBEDTLS_ERR_SSL_TIMEOUT;
     }

     if (ret < 0) {
 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
         !defined(EFI32)
         if (WSAGetLastError() == WSAEINTR) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }
 #else
         if (errno == EINTR) {
             return MBEDTLS_ERR_SSL_WANT_READ;
         }
 #endif

         return MBEDTLS_ERR_NET_RECV_FAILED;
     }

     /* This call will not block */
     return mbedtls_net_recv(ctx, buf, len);
 }

 /*
  * Write at most 'len' characters
  */
 int mbedtls_net_send(void *ctx, const unsigned char *buf, size_t len)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     int fd = ((mbedtls_net_context *) ctx)->fd;

     ret = check_fd(fd, 0);
     if (ret != 0) {
         return ret;
     }

     ret = (int) write(fd, buf, len);

     if (ret < 0) {
         if (net_would_block(ctx) != 0) {
             return MBEDTLS_ERR_SSL_WANT_WRITE;
         }

 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
         !defined(EFI32)
         if (WSAGetLastError() == WSAECONNRESET) {
             return MBEDTLS_ERR_NET_CONN_RESET;
         }
 #else
         if (errno == EPIPE || errno == ECONNRESET) {
             return MBEDTLS_ERR_NET_CONN_RESET;
         }

         if (errno == EINTR) {
             return MBEDTLS_ERR_SSL_WANT_WRITE;
         }
 #endif

         return MBEDTLS_ERR_NET_SEND_FAILED;
     }

     return ret;
 }

 /*
  * Close the connection
  */
 void mbedtls_net_close(mbedtls_net_context *ctx)
 {
     if (ctx->fd == -1) {
         return;
     }

     close(ctx->fd);

     ctx->fd = -1;
 }

 /*
  * Gracefully close the connection
  */
 void mbedtls_net_free(mbedtls_net_context *ctx)
 {
     if (ctx->fd == -1) {
         return;
     }

     shutdown(ctx->fd, 2);
     close(ctx->fd);

     ctx->fd = -1;
 }

 #endif /* MBEDTLS_NET_C */
	/*
	* TCP/IP or UDP/IP networking functions
	*
	* Copyright The Mbed TLS Contributors
	* SPDX-License-Identifier: Apache-2.0
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may
	* not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	/* Enable definition of getaddrinfo() even when compiling with -std=c99. Must
	* be set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
	* Harmless on other platforms. */
	#ifndef _POSIX_C_SOURCE
	#define _POSIX_C_SOURCE 200112L
	#endif
	#ifndef _XOPEN_SOURCE
	#define _XOPEN_SOURCE 600 /* sockaddr_storage */
	#endif

	#include "common.h"

	#if defined(MBEDTLS_NET_C)

	#if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
	!defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
	!defined(__HAIKU__) && !defined(__midipix__)
	#error "This module only works on Unix and Windows, see MBEDTLS_NET_C in mbedtls_config.h"
	#endif

	#include "mbedtls/platform.h"

	#include "mbedtls/net_sockets.h"
	#include "mbedtls/error.h"

	#include <string.h>

	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)

	#define IS_EINTR(ret) ((ret) == WSAEINTR)

	#if !defined(_WIN32_WINNT)
	/* Enables getaddrinfo() & Co */
	#define _WIN32_WINNT 0x0501
	#endif

	#include <ws2tcpip.h>

	#include <winsock2.h>
	#include <windows.h>
	#if (_WIN32_WINNT < 0x0501)
	#include <wspiapi.h>
	#endif

	#if defined(_MSC_VER)
	#if defined(_WIN32_WCE)
	#pragma comment( lib, "ws2.lib" )
	#else
	#pragma comment( lib, "ws2_32.lib" )
	#endif
	#endif /* _MSC_VER */

	#define read(fd, buf, len) recv(fd, (char *) (buf), (int) (len), 0)
	#define write(fd, buf, len) send(fd, (char *) (buf), (int) (len), 0)
	#define close(fd) closesocket(fd)

	static int wsa_init_done = 0;

	#else /* ( _WIN32 \|\| _WIN32_WCE ) && !EFIX64 && !EFI32 */

	#include <sys/types.h>
	#include <sys/socket.h>
	#include <netinet/in.h>
	#include <arpa/inet.h>
	#include <sys/time.h>
	#include <unistd.h>
	#include <signal.h>
	#include <fcntl.h>
	#include <netdb.h>
	#include <errno.h>

	#define IS_EINTR(ret) ((ret) == EINTR)

	#endif /* ( _WIN32 \|\| _WIN32_WCE ) && !EFIX64 && !EFI32 */

	/* Some MS functions want int and MSVC warns if we pass size_t,
	* but the standard functions use socklen_t, so cast only for MSVC */
	#if defined(_MSC_VER)
	#define MSVC_INT_CAST (int)
	#else
	#define MSVC_INT_CAST
	#endif

	#include <stdio.h>

	#if defined(MBEDTLS_HAVE_TIME)
	#include <time.h>
	#endif

	#include <stdint.h>

	/*
	* Prepare for using the sockets interface
	*/
	static int net_prepare(void)
	{
	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	WSADATA wsaData;

	if (wsa_init_done == 0) {
	if (WSAStartup(MAKEWORD(2, 0), &wsaData) != 0) {
	return MBEDTLS_ERR_NET_SOCKET_FAILED;
	}

	wsa_init_done = 1;
	}
	#else
	#if !defined(EFIX64) && !defined(EFI32)
	signal(SIGPIPE, SIG_IGN);
	#endif
	#endif
	return 0;
	}

	/*
	* Return 0 if the file descriptor is valid, an error otherwise.
	* If for_select != 0, check whether the file descriptor is within the range
	* allowed for fd_set used for the FD_xxx macros and the select() function.
	*/
	static int check_fd(int fd, int for_select)
	{
	if (fd < 0) {
	return MBEDTLS_ERR_NET_INVALID_CONTEXT;
	}

	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	(void) for_select;
	#else
	/* A limitation of select() is that it only works with file descriptors
	* that are strictly less than FD_SETSIZE. This is a limitation of the
	* fd_set type. Error out early, because attempting to call FD_SET on a
	* large file descriptor is a buffer overflow on typical platforms. */
	if (for_select && fd >= FD_SETSIZE) {
	return MBEDTLS_ERR_NET_POLL_FAILED;
	}
	#endif

	return 0;
	}

	/*
	* Initialize a context
	*/
	void mbedtls_net_init(mbedtls_net_context *ctx)
	{
	ctx->fd = -1;
	}

	/*
	* Initiate a TCP connection with host:port and the given protocol
	*/
	int mbedtls_net_connect(mbedtls_net_context ctx, const char host,
	const char *port, int proto)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	struct addrinfo hints, addr_list, cur;

	if ((ret = net_prepare()) != 0) {
	return ret;
	}

	/* Do name resolution with both IPv6 and IPv4 */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
	hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;

	if (getaddrinfo(host, port, &hints, &addr_list) != 0) {
	return MBEDTLS_ERR_NET_UNKNOWN_HOST;
	}

	/* Try the sockaddrs until a connection succeeds */
	ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
	for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
	ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
	cur->ai_protocol);
	if (ctx->fd < 0) {
	ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
	continue;
	}

	if (connect(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) == 0) {
	ret = 0;
	break;
	}

	close(ctx->fd);
	ret = MBEDTLS_ERR_NET_CONNECT_FAILED;
	}

	freeaddrinfo(addr_list);

	return ret;
	}

	/*
	* Create a listening socket on bind_ip:port
	*/
	int mbedtls_net_bind(mbedtls_net_context ctx, const char bind_ip, const char *port, int proto)
	{
	int n, ret;
	struct addrinfo hints, addr_list, cur;

	if ((ret = net_prepare()) != 0) {
	return ret;
	}

	/* Bind to IPv6 and/or IPv4, but only in the desired protocol */
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
	hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
	if (bind_ip == NULL) {
	hints.ai_flags = AI_PASSIVE;
	}

	if (getaddrinfo(bind_ip, port, &hints, &addr_list) != 0) {
	return MBEDTLS_ERR_NET_UNKNOWN_HOST;
	}

	/* Try the sockaddrs until a binding succeeds */
	ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
	for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
	ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
	cur->ai_protocol);
	if (ctx->fd < 0) {
	ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
	continue;
	}

	n = 1;
	if (setsockopt(ctx->fd, SOL_SOCKET, SO_REUSEADDR,
	(const char *) &n, sizeof(n)) != 0) {
	close(ctx->fd);
	ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
	continue;
	}

	if (bind(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) != 0) {
	close(ctx->fd);
	ret = MBEDTLS_ERR_NET_BIND_FAILED;
	continue;
	}

	/* Listen only makes sense for TCP */
	if (proto == MBEDTLS_NET_PROTO_TCP) {
	if (listen(ctx->fd, MBEDTLS_NET_LISTEN_BACKLOG) != 0) {
	close(ctx->fd);
	ret = MBEDTLS_ERR_NET_LISTEN_FAILED;
	continue;
	}
	}

	/* Bind was successful */
	ret = 0;
	break;
	}

	freeaddrinfo(addr_list);

	return ret;

	}

	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	/*
	* Check if the requested operation would be blocking on a non-blocking socket
	* and thus 'failed' with a negative return value.
	*/
	static int net_would_block(const mbedtls_net_context *ctx)
	{
	((void) ctx);
	return WSAGetLastError() == WSAEWOULDBLOCK;
	}
	#else
	/*
	* Check if the requested operation would be blocking on a non-blocking socket
	* and thus 'failed' with a negative return value.
	*
	* Note: on a blocking socket this function always returns 0!
	*/
	static int net_would_block(const mbedtls_net_context *ctx)
	{
	int err = errno;

	/*
	* Never return 'WOULD BLOCK' on a blocking socket
	*/
	if ((fcntl(ctx->fd, F_GETFL) & O_NONBLOCK) != O_NONBLOCK) {
	errno = err;
	return 0;
	}

	switch (errno = err) {
	#if defined EAGAIN
	case EAGAIN:
	#endif
	#if defined EWOULDBLOCK && EWOULDBLOCK != EAGAIN
	case EWOULDBLOCK:
	#endif
	return 1;
	}
	return 0;
	}
	#endif /* ( _WIN32 \|\| _WIN32_WCE ) && !EFIX64 && !EFI32 */

	/*
	* Accept a connection from a remote client
	*/
	int mbedtls_net_accept(mbedtls_net_context *bind_ctx,
	mbedtls_net_context *client_ctx,
	void client_ip, size_t buf_size, size_t ip_len)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	int type;

	struct sockaddr_storage client_addr;

	#if defined(__socklen_t_defined) \|\| defined(_SOCKLEN_T) \|\| \
	defined(_SOCKLEN_T_DECLARED) \|\| defined(__DEFINED_socklen_t) \|\| \
	defined(socklen_t) \|\| (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L)
	socklen_t n = (socklen_t) sizeof(client_addr);
	socklen_t type_len = (socklen_t) sizeof(type);
	#else
	int n = (int) sizeof(client_addr);
	int type_len = (int) sizeof(type);
	#endif

	/* Is this a TCP or UDP socket? */
	if (getsockopt(bind_ctx->fd, SOL_SOCKET, SO_TYPE,
	(void *) &type, &type_len) != 0 \|\|
	(type != SOCK_STREAM && type != SOCK_DGRAM)) {
	return MBEDTLS_ERR_NET_ACCEPT_FAILED;
	}

	if (type == SOCK_STREAM) {
	/* TCP: actual accept() */
	ret = client_ctx->fd = (int) accept(bind_ctx->fd,
	(struct sockaddr *) &client_addr, &n);
	} else {
	/* UDP: wait for a message, but keep it in the queue */
	char buf[1] = { 0 };

	ret = (int) recvfrom(bind_ctx->fd, buf, sizeof(buf), MSG_PEEK,
	(struct sockaddr *) &client_addr, &n);

	#if defined(_WIN32)
	if (ret == SOCKET_ERROR &&
	WSAGetLastError() == WSAEMSGSIZE) {
	/* We know buf is too small, thanks, just peeking here */
	ret = 0;
	}
	#endif
	}

	if (ret < 0) {
	if (net_would_block(bind_ctx) != 0) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}

	return MBEDTLS_ERR_NET_ACCEPT_FAILED;
	}

	/* UDP: hijack the listening socket to communicate with the client,
	* then bind a new socket to accept new connections */
	if (type != SOCK_STREAM) {
	struct sockaddr_storage local_addr;
	int one = 1;

	if (connect(bind_ctx->fd, (struct sockaddr *) &client_addr, n) != 0) {
	return MBEDTLS_ERR_NET_ACCEPT_FAILED;
	}

	client_ctx->fd = bind_ctx->fd;
	bind_ctx->fd = -1; /* In case we exit early */

	n = sizeof(struct sockaddr_storage);
	if (getsockname(client_ctx->fd,
	(struct sockaddr *) &local_addr, &n) != 0 \|\|
	(bind_ctx->fd = (int) socket(local_addr.ss_family,
	SOCK_DGRAM, IPPROTO_UDP)) < 0 \|\|
	setsockopt(bind_ctx->fd, SOL_SOCKET, SO_REUSEADDR,
	(const char *) &one, sizeof(one)) != 0) {
	return MBEDTLS_ERR_NET_SOCKET_FAILED;
	}

	if (bind(bind_ctx->fd, (struct sockaddr *) &local_addr, n) != 0) {
	return MBEDTLS_ERR_NET_BIND_FAILED;
	}
	}

	if (client_ip != NULL) {
	if (client_addr.ss_family == AF_INET) {
	struct sockaddr_in addr4 = (struct sockaddr_in ) &client_addr;
	*ip_len = sizeof(addr4->sin_addr.s_addr);

	if (buf_size < *ip_len) {
	return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
	}

	memcpy(client_ip, &addr4->sin_addr.s_addr, *ip_len);
	} else {
	struct sockaddr_in6 addr6 = (struct sockaddr_in6 ) &client_addr;
	*ip_len = sizeof(addr6->sin6_addr.s6_addr);

	if (buf_size < *ip_len) {
	return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
	}

	memcpy(client_ip, &addr6->sin6_addr.s6_addr, *ip_len);
	}
	}

	return 0;
	}

	/*
	* Set the socket blocking or non-blocking
	*/
	int mbedtls_net_set_block(mbedtls_net_context *ctx)
	{
	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	u_long n = 0;
	return ioctlsocket(ctx->fd, FIONBIO, &n);
	#else
	return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) & ~O_NONBLOCK);
	#endif
	}

	int mbedtls_net_set_nonblock(mbedtls_net_context *ctx)
	{
	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	u_long n = 1;
	return ioctlsocket(ctx->fd, FIONBIO, &n);
	#else
	return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) \| O_NONBLOCK);
	#endif
	}

	/*
	* Check if data is available on the socket
	*/

	int mbedtls_net_poll(mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	struct timeval tv;

	fd_set read_fds;
	fd_set write_fds;

	int fd = ctx->fd;

	ret = check_fd(fd, 1);
	if (ret != 0) {
	return ret;
	}

	#if defined(__has_feature)
	#if __has_feature(memory_sanitizer)
	/* Ensure that memory sanitizers consider read_fds and write_fds as
	* initialized even on platforms such as Glibc/x86_64 where FD_ZERO
	* is implemented in assembly. */
	memset(&read_fds, 0, sizeof(read_fds));
	memset(&write_fds, 0, sizeof(write_fds));
	#endif
	#endif

	FD_ZERO(&read_fds);
	if (rw & MBEDTLS_NET_POLL_READ) {
	rw &= ~MBEDTLS_NET_POLL_READ;
	FD_SET(fd, &read_fds);
	}

	FD_ZERO(&write_fds);
	if (rw & MBEDTLS_NET_POLL_WRITE) {
	rw &= ~MBEDTLS_NET_POLL_WRITE;
	FD_SET(fd, &write_fds);
	}

	if (rw != 0) {
	return MBEDTLS_ERR_NET_BAD_INPUT_DATA;
	}

	tv.tv_sec = timeout / 1000;
	tv.tv_usec = (timeout % 1000) * 1000;

	do {
	ret = select(fd + 1, &read_fds, &write_fds, NULL,
	timeout == (uint32_t) -1 ? NULL : &tv);
	} while (IS_EINTR(ret));

	if (ret < 0) {
	return MBEDTLS_ERR_NET_POLL_FAILED;
	}

	ret = 0;
	if (FD_ISSET(fd, &read_fds)) {
	ret \|= MBEDTLS_NET_POLL_READ;
	}
	if (FD_ISSET(fd, &write_fds)) {
	ret \|= MBEDTLS_NET_POLL_WRITE;
	}

	return ret;
	}

	/*
	* Portable usleep helper
	*/
	void mbedtls_net_usleep(unsigned long usec)
	{
	#if defined(_WIN32)
	Sleep((usec + 999) / 1000);
	#else
	struct timeval tv;
	tv.tv_sec = usec / 1000000;
	#if defined(__unix__) \|\| defined(__unix) \|\| \
	(defined(__APPLE__) && defined(__MACH__))
	tv.tv_usec = (suseconds_t) usec % 1000000;
	#else
	tv.tv_usec = usec % 1000000;
	#endif
	select(0, NULL, NULL, NULL, &tv);
	#endif
	}

	/*
	* Read at most 'len' characters
	*/
	int mbedtls_net_recv(void ctx, unsigned char buf, size_t len)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	int fd = ((mbedtls_net_context *) ctx)->fd;

	ret = check_fd(fd, 0);
	if (ret != 0) {
	return ret;
	}

	ret = (int) read(fd, buf, len);

	if (ret < 0) {
	if (net_would_block(ctx) != 0) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}

	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	if (WSAGetLastError() == WSAECONNRESET) {
	return MBEDTLS_ERR_NET_CONN_RESET;
	}
	#else
	if (errno == EPIPE \|\| errno == ECONNRESET) {
	return MBEDTLS_ERR_NET_CONN_RESET;
	}

	if (errno == EINTR) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}
	#endif

	return MBEDTLS_ERR_NET_RECV_FAILED;
	}

	return ret;
	}

	/*
	* Read at most 'len' characters, blocking for at most 'timeout' ms
	*/
	int mbedtls_net_recv_timeout(void ctx, unsigned char buf,
	size_t len, uint32_t timeout)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	struct timeval tv;
	fd_set read_fds;
	int fd = ((mbedtls_net_context *) ctx)->fd;

	ret = check_fd(fd, 1);
	if (ret != 0) {
	return ret;
	}

	FD_ZERO(&read_fds);
	FD_SET(fd, &read_fds);

	tv.tv_sec = timeout / 1000;
	tv.tv_usec = (timeout % 1000) * 1000;

	ret = select(fd + 1, &read_fds, NULL, NULL, timeout == 0 ? NULL : &tv);

	/* Zero fds ready means we timed out */
	if (ret == 0) {
	return MBEDTLS_ERR_SSL_TIMEOUT;
	}

	if (ret < 0) {
	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	if (WSAGetLastError() == WSAEINTR) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}
	#else
	if (errno == EINTR) {
	return MBEDTLS_ERR_SSL_WANT_READ;
	}
	#endif

	return MBEDTLS_ERR_NET_RECV_FAILED;
	}

	/* This call will not block */
	return mbedtls_net_recv(ctx, buf, len);
	}

	/*
	* Write at most 'len' characters
	*/
	int mbedtls_net_send(void ctx, const unsigned char buf, size_t len)
	{
	int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
	int fd = ((mbedtls_net_context *) ctx)->fd;

	ret = check_fd(fd, 0);
	if (ret != 0) {
	return ret;
	}

	ret = (int) write(fd, buf, len);

	if (ret < 0) {
	if (net_would_block(ctx) != 0) {
	return MBEDTLS_ERR_SSL_WANT_WRITE;
	}

	#if (defined(_WIN32) \|\| defined(_WIN32_WCE)) && !defined(EFIX64) && \
	!defined(EFI32)
	if (WSAGetLastError() == WSAECONNRESET) {
	return MBEDTLS_ERR_NET_CONN_RESET;
	}
	#else
	if (errno == EPIPE \|\| errno == ECONNRESET) {
	return MBEDTLS_ERR_NET_CONN_RESET;
	}

	if (errno == EINTR) {
	return MBEDTLS_ERR_SSL_WANT_WRITE;
	}
	#endif

	return MBEDTLS_ERR_NET_SEND_FAILED;
	}

	return ret;
	}

	/*
	* Close the connection
	*/
	void mbedtls_net_close(mbedtls_net_context *ctx)
	{
	if (ctx->fd == -1) {
	return;
	}

	close(ctx->fd);

	ctx->fd = -1;
	}

	/*
	* Gracefully close the connection
	*/
	void mbedtls_net_free(mbedtls_net_context *ctx)
	{
	if (ctx->fd == -1) {
	return;
	}

	shutdown(ctx->fd, 2);
	close(ctx->fd);

	ctx->fd = -1;
	}

	#endif /* MBEDTLS_NET_C */