1 /*
2 * Copyright 1995-2026 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 /* socket-related functions used by s_client and s_server */
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <errno.h>
15 #include <signal.h>
16 #include <openssl/opensslconf.h>
17
18 /*
19 * With IPv6, it looks like Digital has mixed up the proper order of
20 * recursive header file inclusion, resulting in the compiler complaining
21 * that u_int isn't defined, but only if _POSIX_C_SOURCE is defined, which is
22 * needed to have fileno() declared correctly... So let's define u_int
23 */
24 #if defined(OPENSSL_SYS_VMS_DECC) && !defined(__U_INT)
25 #define __U_INT
26 typedef unsigned int u_int;
27 #endif
28
29 #ifdef _WIN32
30 #include <process.h>
31
32 /* MSVC renamed some POSIX functions to have an underscore prefix. */
33 #ifdef _MSC_VER
34 #define getpid _getpid
35 #endif
36 #endif
37
38 #ifndef OPENSSL_NO_SOCK
39
40 #include "internal/e_os.h"
41 #include "apps.h"
42 #include "s_apps.h"
43 #include "internal/sockets.h" /* for openssl_fdset() */
44
45 #include <openssl/bio.h>
46 #include <openssl/err.h>
47
48 /* Keep track of our peer's address for the cookie callback */
49 BIO_ADDR *ourpeer = NULL;
50
51 /*
52 * init_client - helper routine to set up socket communication
53 * @sock: pointer to storage of resulting socket.
54 * @host: the hostname or path (for AF_UNIX) to connect to.
55 * @port: the port to connect to (ignored for AF_UNIX).
56 * @bindhost: source host or path (for AF_UNIX).
57 * @bindport: source port (ignored for AF_UNIX).
58 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
59 * AF_UNSPEC
60 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
61 * @protocol: socket protocol, e.g. IPPROTO_TCP or IPPROTO_UDP (or 0 for any)
62 * @tfo: flag to enable TCP Fast Open
63 * @doconn: whether we should call BIO_connect() on the socket
64 * @ba_ret: BIO_ADDR for the remote peer, to be freed by caller
65 *
66 * This will create a socket and use it to connect to a host:port, or if
67 * family == AF_UNIX, to the path found in host.
68 *
69 * If the host has more than one address, it will try them one by one until
70 * a successful connection is established. The resulting socket will be
71 * found in *sock on success, it will be given INVALID_SOCKET otherwise.
72 *
73 * Returns 1 on success, 0 on failure.
74 */
init_client(int * sock,const char * host,const char * port,const char * bindhost,const char * bindport,int family,int type,int protocol,int tfo,int doconn,BIO_ADDR ** ba_ret)75 int init_client(int *sock, const char *host, const char *port,
76 const char *bindhost, const char *bindport,
77 int family, int type, int protocol, int tfo, int doconn,
78 BIO_ADDR **ba_ret)
79 {
80 BIO_ADDRINFO *res = NULL;
81 BIO_ADDRINFO *bindaddr = NULL;
82 const BIO_ADDRINFO *ai = NULL;
83 const BIO_ADDRINFO *bi = NULL;
84 int found = 0;
85 int ret;
86 int options = 0;
87
88 if (BIO_sock_init() != 1)
89 return 0;
90
91 ret = BIO_lookup_ex(host, port, BIO_LOOKUP_CLIENT, family, type, protocol,
92 &res);
93 if (ret == 0) {
94 ERR_print_errors(bio_err);
95 return 0;
96 }
97
98 if (bindhost != NULL || bindport != NULL) {
99 ret = BIO_lookup_ex(bindhost, bindport, BIO_LOOKUP_CLIENT,
100 family, type, protocol, &bindaddr);
101 if (ret == 0) {
102 ERR_print_errors(bio_err);
103 goto out;
104 }
105 }
106
107 ret = 0;
108 for (ai = res; ai != NULL; ai = BIO_ADDRINFO_next(ai)) {
109 /* Admittedly, these checks are quite paranoid, we should not get
110 * anything in the BIO_ADDRINFO chain that we haven't
111 * asked for. */
112 OPENSSL_assert((family == AF_UNSPEC
113 || family == BIO_ADDRINFO_family(ai))
114 && (type == 0 || type == BIO_ADDRINFO_socktype(ai))
115 && (protocol == 0
116 || protocol == BIO_ADDRINFO_protocol(ai)));
117
118 if (bindaddr != NULL) {
119 for (bi = bindaddr; bi != NULL; bi = BIO_ADDRINFO_next(bi)) {
120 if (BIO_ADDRINFO_family(bi) == BIO_ADDRINFO_family(ai))
121 break;
122 }
123 if (bi == NULL)
124 continue;
125 ++found;
126 }
127
128 *sock = BIO_socket(BIO_ADDRINFO_family(ai), BIO_ADDRINFO_socktype(ai),
129 BIO_ADDRINFO_protocol(ai), 0);
130 if (*sock == INVALID_SOCKET) {
131 /* Maybe the kernel doesn't support the socket family, even if
132 * BIO_lookup() added it in the returned result...
133 */
134 continue;
135 }
136
137 if (bi != NULL) {
138 if (!BIO_bind(*sock, BIO_ADDRINFO_address(bi),
139 BIO_SOCK_REUSEADDR)) {
140 BIO_closesocket(*sock);
141 *sock = INVALID_SOCKET;
142 break;
143 }
144 }
145
146 #ifndef OPENSSL_NO_SCTP
147 if (protocol == IPPROTO_SCTP) {
148 /*
149 * For SCTP we have to set various options on the socket prior to
150 * connecting. This is done automatically by BIO_new_dgram_sctp().
151 * We don't actually need the created BIO though so we free it again
152 * immediately.
153 */
154 BIO *tmpbio = BIO_new_dgram_sctp(*sock, BIO_NOCLOSE);
155
156 if (tmpbio == NULL) {
157 BIO_closesocket(*sock);
158 *sock = INVALID_SOCKET;
159 continue;
160 }
161 BIO_free(tmpbio);
162 }
163 #endif
164 if (BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP) {
165 options |= BIO_SOCK_NODELAY;
166 if (tfo)
167 options |= BIO_SOCK_TFO;
168 }
169
170 if (doconn && !BIO_connect(*sock, BIO_ADDRINFO_address(ai), options)) {
171 BIO_closesocket(*sock);
172 *sock = INVALID_SOCKET;
173 continue;
174 }
175
176 /* Save the address */
177 if (tfo || !doconn) {
178 if (ba_ret == NULL) {
179 BIO_printf(bio_err, "Internal error\n");
180 BIO_closesocket(*sock);
181 *sock = INVALID_SOCKET;
182 goto out;
183 }
184
185 *ba_ret = BIO_ADDR_dup(BIO_ADDRINFO_address(ai));
186 }
187
188 /* Success, don't try any more addresses */
189 break;
190 }
191
192 if (*sock == INVALID_SOCKET) {
193 if (bindaddr != NULL && !found) {
194 BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
195 #ifdef AF_INET6
196 BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
197 #endif
198 BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 "
199 : BIO_ADDRINFO_family(res) == AF_UNIX ? "unix "
200 : "",
201 bindhost != NULL ? bindhost : "",
202 bindport != NULL ? ":" : "",
203 bindport != NULL ? bindport : "");
204 ERR_clear_error();
205 ret = 0;
206 }
207 ERR_print_errors(bio_err);
208 } else {
209 char *hostname = NULL;
210
211 hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1);
212 if (hostname != NULL) {
213 BIO_printf(bio_err, "Connecting to %s\n", hostname);
214 OPENSSL_free(hostname);
215 }
216 /* Remove any stale errors from previous connection attempts */
217 ERR_clear_error();
218 ret = 1;
219 }
220 out:
221 if (bindaddr != NULL) {
222 BIO_ADDRINFO_free(bindaddr);
223 }
224 BIO_ADDRINFO_free(res);
225 return ret;
226 }
227
get_sock_info_address(int asock,char ** hostname,char ** service)228 void get_sock_info_address(int asock, char **hostname, char **service)
229 {
230 union BIO_sock_info_u info;
231
232 if (hostname != NULL)
233 *hostname = NULL;
234 if (service != NULL)
235 *service = NULL;
236
237 if ((info.addr = BIO_ADDR_new()) != NULL
238 && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)) {
239 if (hostname != NULL)
240 *hostname = BIO_ADDR_hostname_string(info.addr, 1);
241 if (service != NULL)
242 *service = BIO_ADDR_service_string(info.addr, 1);
243 }
244 BIO_ADDR_free(info.addr);
245 }
246
report_server_accept(BIO * out,int asock,int with_address,int with_pid)247 int report_server_accept(BIO *out, int asock, int with_address, int with_pid)
248 {
249 int success = 1;
250
251 if (BIO_printf(out, "ACCEPT") <= 0)
252 return 0;
253 if (with_address) {
254 char *hostname, *service;
255
256 get_sock_info_address(asock, &hostname, &service);
257 success = hostname != NULL && service != NULL;
258 if (success)
259 success = BIO_printf(out,
260 strchr(hostname, ':') == NULL
261 ? /* IPv4 */ " %s:%s"
262 : /* IPv6 */ " [%s]:%s",
263 hostname, service)
264 > 0;
265 else
266 (void)BIO_printf(out, "unknown:error\n");
267 OPENSSL_free(hostname);
268 OPENSSL_free(service);
269 }
270 if (with_pid)
271 success *= BIO_printf(out, " PID=%d", getpid()) > 0;
272 success *= BIO_printf(out, "\n") > 0;
273 (void)BIO_flush(out);
274
275 return success;
276 }
277
278 /*
279 * do_server - helper routine to perform a server operation
280 * @accept_sock: pointer to storage of resulting socket.
281 * @host: the hostname or path (for AF_UNIX) to connect to.
282 * @port: the port to connect to (ignored for AF_UNIX).
283 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
284 * AF_UNSPEC
285 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
286 * @cb: pointer to a function that receives the accepted socket and
287 * should perform the communication with the connecting client.
288 * @context: pointer to memory that's passed verbatim to the cb function.
289 * @naccept: number of times an incoming connect should be accepted. If -1,
290 * unlimited number.
291 *
292 * This will create a socket and use it to listen to a host:port, or if
293 * family == AF_UNIX, to the path found in host, then start accepting
294 * incoming connections and run cb on the resulting socket.
295 *
296 * 0 on failure, something other on success.
297 */
do_server(int * accept_sock,const char * host,const char * port,int family,int type,int protocol,do_server_cb cb,unsigned char * context,int naccept,BIO * bio_s_out,int tfo)298 int do_server(int *accept_sock, const char *host, const char *port,
299 int family, int type, int protocol, do_server_cb cb,
300 unsigned char *context, int naccept, BIO *bio_s_out,
301 int tfo)
302 {
303 int asock = 0;
304 int sock;
305 int i;
306 BIO_ADDRINFO *res = NULL;
307 const BIO_ADDRINFO *next;
308 int sock_family, sock_type, sock_protocol, sock_port;
309 const BIO_ADDR *sock_address;
310 int sock_family_fallback = AF_UNSPEC;
311 const BIO_ADDR *sock_address_fallback = NULL;
312 int sock_options = BIO_SOCK_REUSEADDR;
313 int ret = 0;
314
315 if (BIO_sock_init() != 1)
316 return 0;
317
318 if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
319 &res)) {
320 ERR_print_errors(bio_err);
321 return 0;
322 }
323
324 /* Admittedly, these checks are quite paranoid, we should not get
325 * anything in the BIO_ADDRINFO chain that we haven't asked for */
326 OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
327 && (type == 0 || type == BIO_ADDRINFO_socktype(res))
328 && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
329
330 sock_family = BIO_ADDRINFO_family(res);
331 sock_type = BIO_ADDRINFO_socktype(res);
332 sock_protocol = BIO_ADDRINFO_protocol(res);
333 sock_address = BIO_ADDRINFO_address(res);
334 next = BIO_ADDRINFO_next(res);
335 if (tfo && sock_type == SOCK_STREAM)
336 sock_options |= BIO_SOCK_TFO;
337 #ifdef AF_INET6
338 if (sock_family == AF_INET6)
339 sock_options |= BIO_SOCK_V6_ONLY;
340 if (next != NULL
341 && BIO_ADDRINFO_socktype(next) == sock_type
342 && BIO_ADDRINFO_protocol(next) == sock_protocol) {
343 if (sock_family == AF_INET
344 && BIO_ADDRINFO_family(next) == AF_INET6) {
345 /* In case AF_INET6 is returned but not supported by the
346 * kernel, retry with the first detected address family */
347 sock_family_fallback = sock_family;
348 sock_address_fallback = sock_address;
349 sock_family = AF_INET6;
350 sock_address = BIO_ADDRINFO_address(next);
351 } else if (sock_family == AF_INET6
352 && BIO_ADDRINFO_family(next) == AF_INET) {
353 sock_options &= ~BIO_SOCK_V6_ONLY;
354 }
355 }
356 #endif
357
358 asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
359 if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) {
360 asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0);
361 sock_address = sock_address_fallback;
362 }
363 if (asock == INVALID_SOCKET
364 || !BIO_listen(asock, sock_address, sock_options)) {
365 BIO_ADDRINFO_free(res);
366 ERR_print_errors(bio_err);
367 if (asock != INVALID_SOCKET)
368 BIO_closesocket(asock);
369 goto end;
370 }
371
372 #ifndef OPENSSL_NO_SCTP
373 if (protocol == IPPROTO_SCTP) {
374 /*
375 * For SCTP we have to set various options on the socket prior to
376 * accepting. This is done automatically by BIO_new_dgram_sctp().
377 * We don't actually need the created BIO though so we free it again
378 * immediately.
379 */
380 BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
381
382 if (tmpbio == NULL) {
383 BIO_ADDRINFO_free(res);
384 BIO_closesocket(asock);
385 ERR_print_errors(bio_err);
386 goto end;
387 }
388 BIO_free(tmpbio);
389 }
390 #endif
391
392 sock_port = BIO_ADDR_rawport(sock_address);
393
394 BIO_ADDRINFO_free(res);
395 res = NULL;
396
397 if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) {
398 BIO_closesocket(asock);
399 ERR_print_errors(bio_err);
400 goto end;
401 }
402
403 if (accept_sock != NULL)
404 *accept_sock = asock;
405 for (;;) {
406 char sink[64];
407 struct timeval timeout;
408 fd_set readfds;
409
410 if (type == SOCK_STREAM) {
411 BIO_ADDR_free(ourpeer);
412 ourpeer = BIO_ADDR_new();
413 if (ourpeer == NULL) {
414 BIO_closesocket(asock);
415 ERR_print_errors(bio_err);
416 goto end;
417 }
418 do {
419 sock = BIO_accept_ex(asock, ourpeer, 0);
420 } while (sock < 0 && BIO_sock_should_retry(sock));
421 if (sock < 0) {
422 ERR_print_errors(bio_err);
423 BIO_closesocket(asock);
424 break;
425 }
426
427 if (naccept != -1)
428 naccept--;
429
430 BIO_set_tcp_ndelay(sock, 1);
431 i = (*cb)(sock, type, protocol, context);
432
433 /*
434 * If we ended with an alert being sent, but still with data in the
435 * network buffer to be read, then calling BIO_closesocket() will
436 * result in a TCP-RST being sent. On some platforms (notably
437 * Windows) then this will result in the peer immediately abandoning
438 * the connection including any buffered alert data before it has
439 * had a chance to be read. Shutting down the sending side first,
440 * and then closing the socket sends TCP-FIN first followed by
441 * TCP-RST. This seems to allow the peer to read the alert data.
442 */
443 shutdown(sock, 1); /* SHUT_WR */
444 /*
445 * We just said we have nothing else to say, but it doesn't mean
446 * that the other side has nothing. It's even recommended to
447 * consume incoming data. [In testing context this ensures that
448 * alerts are passed on...]
449 */
450 timeout.tv_sec = 0;
451 timeout.tv_usec = 500000; /* some extreme round-trip */
452 do {
453 FD_ZERO(&readfds);
454 openssl_fdset(sock, &readfds);
455 } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
456 && readsocket(sock, sink, sizeof(sink)) > 0);
457
458 BIO_closesocket(sock);
459 } else {
460 if (naccept != -1)
461 naccept--;
462
463 i = (*cb)(asock, type, protocol, context);
464 }
465
466 if (i < 0 || naccept == 0) {
467 BIO_closesocket(asock);
468 asock = INVALID_SOCKET;
469 ret = i;
470 break;
471 }
472 }
473 end:
474 #ifdef AF_UNIX
475 if (family == AF_UNIX)
476 unlink(host);
477 #endif
478 BIO_ADDR_free(ourpeer);
479 ourpeer = NULL;
480 return ret;
481 }
482
do_ssl_shutdown(SSL * ssl)483 void do_ssl_shutdown(SSL *ssl)
484 {
485 int ret;
486
487 do {
488 /* We only do unidirectional shutdown */
489 ret = SSL_shutdown(ssl);
490 if (ret < 0) {
491 switch (SSL_get_error(ssl, ret)) {
492 case SSL_ERROR_WANT_READ:
493 case SSL_ERROR_WANT_WRITE:
494 case SSL_ERROR_WANT_ASYNC:
495 case SSL_ERROR_WANT_ASYNC_JOB:
496 /* We just do busy waiting. Nothing clever */
497 continue;
498 }
499 ret = 0;
500 }
501 } while (ret < 0);
502 }
503
504 #endif /* OPENSSL_NO_SOCK */
505