1 /*
2  *  TCP/IP or UDP/IP networking functions
3  *
4  *  Copyright The Mbed TLS Contributors
5  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6  */
7 
8 /* Enable definition of getaddrinfo() even when compiling with -std=c99. Must
9  * be set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
10  * Harmless on other platforms. */
11 #ifndef _POSIX_C_SOURCE
12 #define _POSIX_C_SOURCE 200112L
13 #endif
14 #ifndef _XOPEN_SOURCE
15 #define _XOPEN_SOURCE 600 /* sockaddr_storage */
16 #endif
17 
18 #include "common.h"
19 
20 #if defined(MBEDTLS_NET_C)
21 
22 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
23     !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
24     !defined(__HAIKU__) && !defined(__midipix__)
25 #error "This module only works on Unix and Windows, see MBEDTLS_NET_C in mbedtls_config.h"
26 #endif
27 
28 #include "mbedtls/platform.h"
29 
30 #include "mbedtls/net_sockets.h"
31 #include "mbedtls/error.h"
32 
33 #include <string.h>
34 
35 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
36     !defined(EFI32)
37 
38 #define IS_EINTR(ret) ((ret) == WSAEINTR)
39 
40 #include <ws2tcpip.h>
41 
42 #include <winsock2.h>
43 #include <windows.h>
44 #if (_WIN32_WINNT < 0x0501)
45 #include <wspiapi.h>
46 #endif
47 
48 #if defined(_MSC_VER)
49 #if defined(_WIN32_WCE)
50 #pragma comment( lib, "ws2.lib" )
51 #else
52 #pragma comment( lib, "ws2_32.lib" )
53 #endif
54 #endif /* _MSC_VER */
55 
56 #define read(fd, buf, len)        recv(fd, (char *) (buf), (int) (len), 0)
57 #define write(fd, buf, len)       send(fd, (char *) (buf), (int) (len), 0)
58 #define close(fd)               closesocket(fd)
59 
60 static int wsa_init_done = 0;
61 
62 #else /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
63 
64 #include <sys/types.h>
65 #include <sys/socket.h>
66 #include <netinet/in.h>
67 #include <arpa/inet.h>
68 #include <sys/time.h>
69 #include <unistd.h>
70 #include <signal.h>
71 #include <fcntl.h>
72 #include <netdb.h>
73 #include <errno.h>
74 
75 #define IS_EINTR(ret) ((ret) == EINTR)
76 #define SOCKET int
77 
78 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
79 
80 /* Some MS functions want int and MSVC warns if we pass size_t,
81  * but the standard functions use socklen_t, so cast only for MSVC */
82 #if defined(_MSC_VER)
83 #define MSVC_INT_CAST   (int)
84 #else
85 #define MSVC_INT_CAST
86 #endif
87 
88 #include <stdio.h>
89 
90 #if defined(MBEDTLS_HAVE_TIME)
91 #include <time.h>
92 #endif
93 
94 #include <stdint.h>
95 
96 /*
97  * Prepare for using the sockets interface
98  */
net_prepare(void)99 static int net_prepare(void)
100 {
101 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
102     !defined(EFI32)
103     WSADATA wsaData;
104 
105     if (wsa_init_done == 0) {
106         if (WSAStartup(MAKEWORD(2, 0), &wsaData) != 0) {
107             return MBEDTLS_ERR_NET_SOCKET_FAILED;
108         }
109 
110         wsa_init_done = 1;
111     }
112 #else
113 #if !defined(EFIX64) && !defined(EFI32)
114     signal(SIGPIPE, SIG_IGN);
115 #endif
116 #endif
117     return 0;
118 }
119 
120 /*
121  * Return 0 if the file descriptor is valid, an error otherwise.
122  * If for_select != 0, check whether the file descriptor is within the range
123  * allowed for fd_set used for the FD_xxx macros and the select() function.
124  */
check_fd(int fd,int for_select)125 static int check_fd(int fd, int for_select)
126 {
127     if (fd < 0) {
128         return MBEDTLS_ERR_NET_INVALID_CONTEXT;
129     }
130 
131 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
132     !defined(EFI32)
133     (void) for_select;
134 #else
135     /* A limitation of select() is that it only works with file descriptors
136      * that are strictly less than FD_SETSIZE. This is a limitation of the
137      * fd_set type. Error out early, because attempting to call FD_SET on a
138      * large file descriptor is a buffer overflow on typical platforms. */
139     if (for_select && fd >= FD_SETSIZE) {
140         return MBEDTLS_ERR_NET_POLL_FAILED;
141     }
142 #endif
143 
144     return 0;
145 }
146 
147 /*
148  * Initialize a context
149  */
mbedtls_net_init(mbedtls_net_context * ctx)150 void mbedtls_net_init(mbedtls_net_context *ctx)
151 {
152     ctx->fd = -1;
153 }
154 
155 /*
156  * Initiate a TCP connection with host:port and the given protocol
157  */
mbedtls_net_connect(mbedtls_net_context * ctx,const char * host,const char * port,int proto)158 int mbedtls_net_connect(mbedtls_net_context *ctx, const char *host,
159                         const char *port, int proto)
160 {
161     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
162     struct addrinfo hints, *addr_list, *cur;
163 
164     if ((ret = net_prepare()) != 0) {
165         return ret;
166     }
167 
168     /* Do name resolution with both IPv6 and IPv4 */
169     memset(&hints, 0, sizeof(hints));
170     hints.ai_family = AF_UNSPEC;
171     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
172     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
173 
174     if (getaddrinfo(host, port, &hints, &addr_list) != 0) {
175         return MBEDTLS_ERR_NET_UNKNOWN_HOST;
176     }
177 
178     /* Try the sockaddrs until a connection succeeds */
179     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
180     for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
181         ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
182                                cur->ai_protocol);
183         if (ctx->fd < 0) {
184             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
185             continue;
186         }
187 
188         if (connect(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) == 0) {
189             ret = 0;
190             break;
191         }
192 
193         close(ctx->fd);
194         ret = MBEDTLS_ERR_NET_CONNECT_FAILED;
195     }
196 
197     freeaddrinfo(addr_list);
198 
199     return ret;
200 }
201 
202 /*
203  * Create a listening socket on bind_ip:port
204  */
mbedtls_net_bind(mbedtls_net_context * ctx,const char * bind_ip,const char * port,int proto)205 int mbedtls_net_bind(mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto)
206 {
207     int n, ret;
208     struct addrinfo hints, *addr_list, *cur;
209 
210     if ((ret = net_prepare()) != 0) {
211         return ret;
212     }
213 
214     /* Bind to IPv6 and/or IPv4, but only in the desired protocol */
215     memset(&hints, 0, sizeof(hints));
216     hints.ai_family = AF_UNSPEC;
217     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
218     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
219     if (bind_ip == NULL) {
220         hints.ai_flags = AI_PASSIVE;
221     }
222 
223     if (getaddrinfo(bind_ip, port, &hints, &addr_list) != 0) {
224         return MBEDTLS_ERR_NET_UNKNOWN_HOST;
225     }
226 
227     /* Try the sockaddrs until a binding succeeds */
228     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
229     for (cur = addr_list; cur != NULL; cur = cur->ai_next) {
230         ctx->fd = (int) socket(cur->ai_family, cur->ai_socktype,
231                                cur->ai_protocol);
232         if (ctx->fd < 0) {
233             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
234             continue;
235         }
236 
237         n = 1;
238         if (setsockopt(ctx->fd, SOL_SOCKET, SO_REUSEADDR,
239                        (const char *) &n, sizeof(n)) != 0) {
240             close(ctx->fd);
241             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
242             continue;
243         }
244 
245         if (bind(ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen) != 0) {
246             close(ctx->fd);
247             ret = MBEDTLS_ERR_NET_BIND_FAILED;
248             continue;
249         }
250 
251         /* Listen only makes sense for TCP */
252         if (proto == MBEDTLS_NET_PROTO_TCP) {
253             if (listen(ctx->fd, MBEDTLS_NET_LISTEN_BACKLOG) != 0) {
254                 close(ctx->fd);
255                 ret = MBEDTLS_ERR_NET_LISTEN_FAILED;
256                 continue;
257             }
258         }
259 
260         /* Bind was successful */
261         ret = 0;
262         break;
263     }
264 
265     freeaddrinfo(addr_list);
266 
267     return ret;
268 
269 }
270 
271 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
272     !defined(EFI32)
273 /*
274  * Check if the requested operation would be blocking on a non-blocking socket
275  * and thus 'failed' with a negative return value.
276  */
net_would_block(const mbedtls_net_context * ctx)277 static int net_would_block(const mbedtls_net_context *ctx)
278 {
279     ((void) ctx);
280     return WSAGetLastError() == WSAEWOULDBLOCK;
281 }
282 #else
283 /*
284  * Check if the requested operation would be blocking on a non-blocking socket
285  * and thus 'failed' with a negative return value.
286  *
287  * Note: on a blocking socket this function always returns 0!
288  */
net_would_block(const mbedtls_net_context * ctx)289 static int net_would_block(const mbedtls_net_context *ctx)
290 {
291     int err = errno;
292 
293     /*
294      * Never return 'WOULD BLOCK' on a blocking socket
295      */
296     if ((fcntl(ctx->fd, F_GETFL) & O_NONBLOCK) != O_NONBLOCK) {
297         errno = err;
298         return 0;
299     }
300 
301     switch (errno = err) {
302 #if defined EAGAIN
303         case EAGAIN:
304 #endif
305 #if defined EWOULDBLOCK && EWOULDBLOCK != EAGAIN
306         case EWOULDBLOCK:
307 #endif
308     return 1;
309     }
310     return 0;
311 }
312 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
313 
314 /*
315  * Accept a connection from a remote client
316  */
mbedtls_net_accept(mbedtls_net_context * bind_ctx,mbedtls_net_context * client_ctx,void * client_ip,size_t buf_size,size_t * ip_len)317 int mbedtls_net_accept(mbedtls_net_context *bind_ctx,
318                        mbedtls_net_context *client_ctx,
319                        void *client_ip, size_t buf_size, size_t *ip_len)
320 {
321     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
322     int type;
323 
324     struct sockaddr_storage client_addr;
325 
326 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
327     defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t) || \
328     defined(socklen_t) || (defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L)
329     socklen_t n = (socklen_t) sizeof(client_addr);
330     socklen_t type_len = (socklen_t) sizeof(type);
331 #else
332     int n = (int) sizeof(client_addr);
333     int type_len = (int) sizeof(type);
334 #endif
335 
336     /* Is this a TCP or UDP socket? */
337     if (getsockopt(bind_ctx->fd, SOL_SOCKET, SO_TYPE,
338                    (void *) &type, &type_len) != 0 ||
339         (type != SOCK_STREAM && type != SOCK_DGRAM)) {
340         return MBEDTLS_ERR_NET_ACCEPT_FAILED;
341     }
342 
343     if (type == SOCK_STREAM) {
344         /* TCP: actual accept() */
345         ret = client_ctx->fd = (int) accept(bind_ctx->fd,
346                                             (struct sockaddr *) &client_addr, &n);
347     } else {
348         /* UDP: wait for a message, but keep it in the queue */
349         char buf[1] = { 0 };
350 
351         ret = (int) recvfrom(bind_ctx->fd, buf, sizeof(buf), MSG_PEEK,
352                              (struct sockaddr *) &client_addr, &n);
353 
354 #if defined(_WIN32)
355         if (ret == SOCKET_ERROR &&
356             WSAGetLastError() == WSAEMSGSIZE) {
357             /* We know buf is too small, thanks, just peeking here */
358             ret = 0;
359         }
360 #endif
361     }
362 
363     if (ret < 0) {
364         if (net_would_block(bind_ctx) != 0) {
365             return MBEDTLS_ERR_SSL_WANT_READ;
366         }
367 
368         return MBEDTLS_ERR_NET_ACCEPT_FAILED;
369     }
370 
371     /* UDP: hijack the listening socket to communicate with the client,
372      * then bind a new socket to accept new connections */
373     if (type != SOCK_STREAM) {
374         struct sockaddr_storage local_addr;
375         int one = 1;
376 
377         if (connect(bind_ctx->fd, (struct sockaddr *) &client_addr, n) != 0) {
378             return MBEDTLS_ERR_NET_ACCEPT_FAILED;
379         }
380 
381         client_ctx->fd = bind_ctx->fd;
382         bind_ctx->fd   = -1; /* In case we exit early */
383 
384         n = sizeof(struct sockaddr_storage);
385         if (getsockname(client_ctx->fd,
386                         (struct sockaddr *) &local_addr, &n) != 0 ||
387             (bind_ctx->fd = (int) socket(local_addr.ss_family,
388                                          SOCK_DGRAM, IPPROTO_UDP)) < 0 ||
389             setsockopt(bind_ctx->fd, SOL_SOCKET, SO_REUSEADDR,
390                        (const char *) &one, sizeof(one)) != 0) {
391             return MBEDTLS_ERR_NET_SOCKET_FAILED;
392         }
393 
394         if (bind(bind_ctx->fd, (struct sockaddr *) &local_addr, n) != 0) {
395             return MBEDTLS_ERR_NET_BIND_FAILED;
396         }
397     }
398 
399     if (client_ip != NULL) {
400         if (client_addr.ss_family == AF_INET) {
401             struct sockaddr_in *addr4 = (struct sockaddr_in *) &client_addr;
402             *ip_len = sizeof(addr4->sin_addr.s_addr);
403 
404             if (buf_size < *ip_len) {
405                 return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
406             }
407 
408             memcpy(client_ip, &addr4->sin_addr.s_addr, *ip_len);
409         } else {
410             struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &client_addr;
411             *ip_len = sizeof(addr6->sin6_addr.s6_addr);
412 
413             if (buf_size < *ip_len) {
414                 return MBEDTLS_ERR_NET_BUFFER_TOO_SMALL;
415             }
416 
417             memcpy(client_ip, &addr6->sin6_addr.s6_addr, *ip_len);
418         }
419     }
420 
421     return 0;
422 }
423 
424 /*
425  * Set the socket blocking or non-blocking
426  */
mbedtls_net_set_block(mbedtls_net_context * ctx)427 int mbedtls_net_set_block(mbedtls_net_context *ctx)
428 {
429 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
430     !defined(EFI32)
431     u_long n = 0;
432     return ioctlsocket(ctx->fd, FIONBIO, &n);
433 #else
434     return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) & ~O_NONBLOCK);
435 #endif
436 }
437 
mbedtls_net_set_nonblock(mbedtls_net_context * ctx)438 int mbedtls_net_set_nonblock(mbedtls_net_context *ctx)
439 {
440 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
441     !defined(EFI32)
442     u_long n = 1;
443     return ioctlsocket(ctx->fd, FIONBIO, &n);
444 #else
445     return fcntl(ctx->fd, F_SETFL, fcntl(ctx->fd, F_GETFL) | O_NONBLOCK);
446 #endif
447 }
448 
449 /*
450  * Check if data is available on the socket
451  */
452 
mbedtls_net_poll(mbedtls_net_context * ctx,uint32_t rw,uint32_t timeout)453 int mbedtls_net_poll(mbedtls_net_context *ctx, uint32_t rw, uint32_t timeout)
454 {
455     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
456     struct timeval tv;
457 
458     fd_set read_fds;
459     fd_set write_fds;
460 
461     int fd = ctx->fd;
462 
463     ret = check_fd(fd, 1);
464     if (ret != 0) {
465         return ret;
466     }
467 
468 #if defined(__has_feature)
469 #if __has_feature(memory_sanitizer)
470     /* Ensure that memory sanitizers consider read_fds and write_fds as
471      * initialized even on platforms such as Glibc/x86_64 where FD_ZERO
472      * is implemented in assembly. */
473     memset(&read_fds, 0, sizeof(read_fds));
474     memset(&write_fds, 0, sizeof(write_fds));
475 #endif
476 #endif
477 
478     FD_ZERO(&read_fds);
479     if (rw & MBEDTLS_NET_POLL_READ) {
480         rw &= ~MBEDTLS_NET_POLL_READ;
481         FD_SET((SOCKET) fd, &read_fds);
482     }
483 
484     FD_ZERO(&write_fds);
485     if (rw & MBEDTLS_NET_POLL_WRITE) {
486         rw &= ~MBEDTLS_NET_POLL_WRITE;
487         FD_SET((SOCKET) fd, &write_fds);
488     }
489 
490     if (rw != 0) {
491         return MBEDTLS_ERR_NET_BAD_INPUT_DATA;
492     }
493 
494     tv.tv_sec  = timeout / 1000;
495     tv.tv_usec = (timeout % 1000) * 1000;
496 
497     do {
498         ret = select(fd + 1, &read_fds, &write_fds, NULL,
499                      timeout == (uint32_t) -1 ? NULL : &tv);
500     } while (IS_EINTR(ret));
501 
502     if (ret < 0) {
503         return MBEDTLS_ERR_NET_POLL_FAILED;
504     }
505 
506     ret = 0;
507     if (FD_ISSET(fd, &read_fds)) {
508         ret |= MBEDTLS_NET_POLL_READ;
509     }
510     if (FD_ISSET(fd, &write_fds)) {
511         ret |= MBEDTLS_NET_POLL_WRITE;
512     }
513 
514     return ret;
515 }
516 
517 /*
518  * Portable usleep helper
519  */
mbedtls_net_usleep(unsigned long usec)520 void mbedtls_net_usleep(unsigned long usec)
521 {
522 #if defined(_WIN32)
523     Sleep((usec + 999) / 1000);
524 #else
525     struct timeval tv;
526     tv.tv_sec  = usec / 1000000;
527 #if defined(__unix__) || defined(__unix) || \
528     (defined(__APPLE__) && defined(__MACH__))
529     tv.tv_usec = (suseconds_t) usec % 1000000;
530 #else
531     tv.tv_usec = usec % 1000000;
532 #endif
533     select(0, NULL, NULL, NULL, &tv);
534 #endif
535 }
536 
537 /*
538  * Read at most 'len' characters
539  */
mbedtls_net_recv(void * ctx,unsigned char * buf,size_t len)540 int mbedtls_net_recv(void *ctx, unsigned char *buf, size_t len)
541 {
542     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
543     int fd = ((mbedtls_net_context *) ctx)->fd;
544 
545     ret = check_fd(fd, 0);
546     if (ret != 0) {
547         return ret;
548     }
549 
550     ret = (int) read(fd, buf, len);
551 
552     if (ret < 0) {
553         if (net_would_block(ctx) != 0) {
554             return MBEDTLS_ERR_SSL_WANT_READ;
555         }
556 
557 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
558         !defined(EFI32)
559         if (WSAGetLastError() == WSAECONNRESET) {
560             return MBEDTLS_ERR_NET_CONN_RESET;
561         }
562 #else
563         if (errno == EPIPE || errno == ECONNRESET) {
564             return MBEDTLS_ERR_NET_CONN_RESET;
565         }
566 
567         if (errno == EINTR) {
568             return MBEDTLS_ERR_SSL_WANT_READ;
569         }
570 #endif
571 
572         return MBEDTLS_ERR_NET_RECV_FAILED;
573     }
574 
575     return ret;
576 }
577 
578 /*
579  * Read at most 'len' characters, blocking for at most 'timeout' ms
580  */
mbedtls_net_recv_timeout(void * ctx,unsigned char * buf,size_t len,uint32_t timeout)581 int mbedtls_net_recv_timeout(void *ctx, unsigned char *buf,
582                              size_t len, uint32_t timeout)
583 {
584     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
585     struct timeval tv;
586     fd_set read_fds;
587     int fd = ((mbedtls_net_context *) ctx)->fd;
588 
589     ret = check_fd(fd, 1);
590     if (ret != 0) {
591         return ret;
592     }
593 
594     FD_ZERO(&read_fds);
595     FD_SET((SOCKET) fd, &read_fds);
596 
597     tv.tv_sec  = timeout / 1000;
598     tv.tv_usec = (timeout % 1000) * 1000;
599 
600     ret = select(fd + 1, &read_fds, NULL, NULL, timeout == 0 ? NULL : &tv);
601 
602     /* Zero fds ready means we timed out */
603     if (ret == 0) {
604         return MBEDTLS_ERR_SSL_TIMEOUT;
605     }
606 
607     if (ret < 0) {
608 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
609         !defined(EFI32)
610         if (WSAGetLastError() == WSAEINTR) {
611             return MBEDTLS_ERR_SSL_WANT_READ;
612         }
613 #else
614         if (errno == EINTR) {
615             return MBEDTLS_ERR_SSL_WANT_READ;
616         }
617 #endif
618 
619         return MBEDTLS_ERR_NET_RECV_FAILED;
620     }
621 
622     /* This call will not block */
623     return mbedtls_net_recv(ctx, buf, len);
624 }
625 
626 /*
627  * Write at most 'len' characters
628  */
mbedtls_net_send(void * ctx,const unsigned char * buf,size_t len)629 int mbedtls_net_send(void *ctx, const unsigned char *buf, size_t len)
630 {
631     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
632     int fd = ((mbedtls_net_context *) ctx)->fd;
633 
634     ret = check_fd(fd, 0);
635     if (ret != 0) {
636         return ret;
637     }
638 
639     ret = (int) write(fd, buf, len);
640 
641     if (ret < 0) {
642         if (net_would_block(ctx) != 0) {
643             return MBEDTLS_ERR_SSL_WANT_WRITE;
644         }
645 
646 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
647         !defined(EFI32)
648         if (WSAGetLastError() == WSAECONNRESET) {
649             return MBEDTLS_ERR_NET_CONN_RESET;
650         }
651 #else
652         if (errno == EPIPE || errno == ECONNRESET) {
653             return MBEDTLS_ERR_NET_CONN_RESET;
654         }
655 
656         if (errno == EINTR) {
657             return MBEDTLS_ERR_SSL_WANT_WRITE;
658         }
659 #endif
660 
661         return MBEDTLS_ERR_NET_SEND_FAILED;
662     }
663 
664     return ret;
665 }
666 
667 /*
668  * Close the connection
669  */
mbedtls_net_close(mbedtls_net_context * ctx)670 void mbedtls_net_close(mbedtls_net_context *ctx)
671 {
672     if (ctx->fd == -1) {
673         return;
674     }
675 
676     close(ctx->fd);
677 
678     ctx->fd = -1;
679 }
680 
681 /*
682  * Gracefully close the connection
683  */
mbedtls_net_free(mbedtls_net_context * ctx)684 void mbedtls_net_free(mbedtls_net_context *ctx)
685 {
686     if (ctx->fd == -1) {
687         return;
688     }
689 
690     shutdown(ctx->fd, 2);
691     close(ctx->fd);
692 
693     ctx->fd = -1;
694 }
695 
696 #endif /* MBEDTLS_NET_C */
697