1 /*
2 * Copyright 1995-2025 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 ERR_print_errors(bio_err);
158 return 0;
159 }
160 BIO_free(tmpbio);
161 }
162 #endif
163 if (BIO_ADDRINFO_protocol(ai) == IPPROTO_TCP) {
164 options |= BIO_SOCK_NODELAY;
165 if (tfo)
166 options |= BIO_SOCK_TFO;
167 }
168
169 if (doconn && !BIO_connect(*sock, BIO_ADDRINFO_address(ai), options)) {
170 BIO_closesocket(*sock);
171 *sock = INVALID_SOCKET;
172 continue;
173 }
174
175 /* Save the address */
176 if (tfo || !doconn) {
177 if (ba_ret == NULL) {
178 BIO_printf(bio_err, "Internal error\n");
179 BIO_closesocket(*sock);
180 *sock = INVALID_SOCKET;
181 goto out;
182 }
183
184 *ba_ret = BIO_ADDR_dup(BIO_ADDRINFO_address(ai));
185 }
186
187 /* Success, don't try any more addresses */
188 break;
189 }
190
191 if (*sock == INVALID_SOCKET) {
192 if (bindaddr != NULL && !found) {
193 BIO_printf(bio_err, "Can't bind %saddress for %s%s%s\n",
194 #ifdef AF_INET6
195 BIO_ADDRINFO_family(res) == AF_INET6 ? "IPv6 " :
196 #endif
197 BIO_ADDRINFO_family(res) == AF_INET ? "IPv4 " :
198 BIO_ADDRINFO_family(res) == AF_UNIX ? "unix " : "",
199 bindhost != NULL ? bindhost : "",
200 bindport != NULL ? ":" : "",
201 bindport != NULL ? bindport : "");
202 ERR_clear_error();
203 ret = 0;
204 }
205 ERR_print_errors(bio_err);
206 } else {
207 char *hostname = NULL;
208
209 hostname = BIO_ADDR_hostname_string(BIO_ADDRINFO_address(ai), 1);
210 if (hostname != NULL) {
211 BIO_printf(bio_err, "Connecting to %s\n", hostname);
212 OPENSSL_free(hostname);
213 }
214 /* Remove any stale errors from previous connection attempts */
215 ERR_clear_error();
216 ret = 1;
217 }
218 out:
219 if (bindaddr != NULL) {
220 BIO_ADDRINFO_free (bindaddr);
221 }
222 BIO_ADDRINFO_free(res);
223 return ret;
224 }
225
get_sock_info_address(int asock,char ** hostname,char ** service)226 void get_sock_info_address(int asock, char **hostname, char **service)
227 {
228 union BIO_sock_info_u info;
229
230 if (hostname != NULL)
231 *hostname = NULL;
232 if (service != NULL)
233 *service = NULL;
234
235 if ((info.addr = BIO_ADDR_new()) != NULL
236 && BIO_sock_info(asock, BIO_SOCK_INFO_ADDRESS, &info)) {
237 if (hostname != NULL)
238 *hostname = BIO_ADDR_hostname_string(info.addr, 1);
239 if (service != NULL)
240 *service = BIO_ADDR_service_string(info.addr, 1);
241 }
242 BIO_ADDR_free(info.addr);
243 }
244
report_server_accept(BIO * out,int asock,int with_address,int with_pid)245 int report_server_accept(BIO *out, int asock, int with_address, int with_pid)
246 {
247 int success = 1;
248
249 if (BIO_printf(out, "ACCEPT") <= 0)
250 return 0;
251 if (with_address) {
252 char *hostname, *service;
253
254 get_sock_info_address(asock, &hostname, &service);
255 success = hostname != NULL && service != NULL;
256 if (success)
257 success = BIO_printf(out,
258 strchr(hostname, ':') == NULL
259 ? /* IPv4 */ " %s:%s"
260 : /* IPv6 */ " [%s]:%s",
261 hostname, service) > 0;
262 else
263 (void)BIO_printf(out, "unknown:error\n");
264 OPENSSL_free(hostname);
265 OPENSSL_free(service);
266 }
267 if (with_pid)
268 success *= BIO_printf(out, " PID=%d", getpid()) > 0;
269 success *= BIO_printf(out, "\n") > 0;
270 (void)BIO_flush(out);
271
272 return success;
273 }
274
275 /*
276 * do_server - helper routine to perform a server operation
277 * @accept_sock: pointer to storage of resulting socket.
278 * @host: the hostname or path (for AF_UNIX) to connect to.
279 * @port: the port to connect to (ignored for AF_UNIX).
280 * @family: desired socket family, may be AF_INET, AF_INET6, AF_UNIX or
281 * AF_UNSPEC
282 * @type: socket type, must be SOCK_STREAM or SOCK_DGRAM
283 * @cb: pointer to a function that receives the accepted socket and
284 * should perform the communication with the connecting client.
285 * @context: pointer to memory that's passed verbatim to the cb function.
286 * @naccept: number of times an incoming connect should be accepted. If -1,
287 * unlimited number.
288 *
289 * This will create a socket and use it to listen to a host:port, or if
290 * family == AF_UNIX, to the path found in host, then start accepting
291 * incoming connections and run cb on the resulting socket.
292 *
293 * 0 on failure, something other on success.
294 */
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)295 int do_server(int *accept_sock, const char *host, const char *port,
296 int family, int type, int protocol, do_server_cb cb,
297 unsigned char *context, int naccept, BIO *bio_s_out,
298 int tfo)
299 {
300 int asock = 0;
301 int sock;
302 int i;
303 BIO_ADDRINFO *res = NULL;
304 const BIO_ADDRINFO *next;
305 int sock_family, sock_type, sock_protocol, sock_port;
306 const BIO_ADDR *sock_address;
307 int sock_family_fallback = AF_UNSPEC;
308 const BIO_ADDR *sock_address_fallback = NULL;
309 int sock_options = BIO_SOCK_REUSEADDR;
310 int ret = 0;
311
312 if (BIO_sock_init() != 1)
313 return 0;
314
315 if (!BIO_lookup_ex(host, port, BIO_LOOKUP_SERVER, family, type, protocol,
316 &res)) {
317 ERR_print_errors(bio_err);
318 return 0;
319 }
320
321 /* Admittedly, these checks are quite paranoid, we should not get
322 * anything in the BIO_ADDRINFO chain that we haven't asked for */
323 OPENSSL_assert((family == AF_UNSPEC || family == BIO_ADDRINFO_family(res))
324 && (type == 0 || type == BIO_ADDRINFO_socktype(res))
325 && (protocol == 0 || protocol == BIO_ADDRINFO_protocol(res)));
326
327 sock_family = BIO_ADDRINFO_family(res);
328 sock_type = BIO_ADDRINFO_socktype(res);
329 sock_protocol = BIO_ADDRINFO_protocol(res);
330 sock_address = BIO_ADDRINFO_address(res);
331 next = BIO_ADDRINFO_next(res);
332 if (tfo && sock_type == SOCK_STREAM)
333 sock_options |= BIO_SOCK_TFO;
334 #ifdef AF_INET6
335 if (sock_family == AF_INET6)
336 sock_options |= BIO_SOCK_V6_ONLY;
337 if (next != NULL
338 && BIO_ADDRINFO_socktype(next) == sock_type
339 && BIO_ADDRINFO_protocol(next) == sock_protocol) {
340 if (sock_family == AF_INET
341 && BIO_ADDRINFO_family(next) == AF_INET6) {
342 /* In case AF_INET6 is returned but not supported by the
343 * kernel, retry with the first detected address family */
344 sock_family_fallback = sock_family;
345 sock_address_fallback = sock_address;
346 sock_family = AF_INET6;
347 sock_address = BIO_ADDRINFO_address(next);
348 } else if (sock_family == AF_INET6
349 && BIO_ADDRINFO_family(next) == AF_INET) {
350 sock_options &= ~BIO_SOCK_V6_ONLY;
351 }
352 }
353 #endif
354
355 asock = BIO_socket(sock_family, sock_type, sock_protocol, 0);
356 if (asock == INVALID_SOCKET && sock_family_fallback != AF_UNSPEC) {
357 asock = BIO_socket(sock_family_fallback, sock_type, sock_protocol, 0);
358 sock_address = sock_address_fallback;
359 }
360 if (asock == INVALID_SOCKET
361 || !BIO_listen(asock, sock_address, sock_options)) {
362 BIO_ADDRINFO_free(res);
363 ERR_print_errors(bio_err);
364 if (asock != INVALID_SOCKET)
365 BIO_closesocket(asock);
366 goto end;
367 }
368
369 #ifndef OPENSSL_NO_SCTP
370 if (protocol == IPPROTO_SCTP) {
371 /*
372 * For SCTP we have to set various options on the socket prior to
373 * accepting. This is done automatically by BIO_new_dgram_sctp().
374 * We don't actually need the created BIO though so we free it again
375 * immediately.
376 */
377 BIO *tmpbio = BIO_new_dgram_sctp(asock, BIO_NOCLOSE);
378
379 if (tmpbio == NULL) {
380 BIO_closesocket(asock);
381 ERR_print_errors(bio_err);
382 goto end;
383 }
384 BIO_free(tmpbio);
385 }
386 #endif
387
388 sock_port = BIO_ADDR_rawport(sock_address);
389
390 BIO_ADDRINFO_free(res);
391 res = NULL;
392
393 if (!report_server_accept(bio_s_out, asock, sock_port == 0, 0)) {
394 BIO_closesocket(asock);
395 ERR_print_errors(bio_err);
396 goto end;
397 }
398
399 if (accept_sock != NULL)
400 *accept_sock = asock;
401 for (;;) {
402 char sink[64];
403 struct timeval timeout;
404 fd_set readfds;
405
406 if (type == SOCK_STREAM) {
407 BIO_ADDR_free(ourpeer);
408 ourpeer = BIO_ADDR_new();
409 if (ourpeer == NULL) {
410 BIO_closesocket(asock);
411 ERR_print_errors(bio_err);
412 goto end;
413 }
414 do {
415 sock = BIO_accept_ex(asock, ourpeer, 0);
416 } while (sock < 0 && BIO_sock_should_retry(sock));
417 if (sock < 0) {
418 ERR_print_errors(bio_err);
419 BIO_closesocket(asock);
420 break;
421 }
422
423 if (naccept != -1)
424 naccept--;
425 if (naccept == 0)
426 BIO_closesocket(asock);
427
428 BIO_set_tcp_ndelay(sock, 1);
429 i = (*cb)(sock, type, protocol, context);
430
431 /*
432 * If we ended with an alert being sent, but still with data in the
433 * network buffer to be read, then calling BIO_closesocket() will
434 * result in a TCP-RST being sent. On some platforms (notably
435 * Windows) then this will result in the peer immediately abandoning
436 * the connection including any buffered alert data before it has
437 * had a chance to be read. Shutting down the sending side first,
438 * and then closing the socket sends TCP-FIN first followed by
439 * TCP-RST. This seems to allow the peer to read the alert data.
440 */
441 shutdown(sock, 1); /* SHUT_WR */
442 /*
443 * We just said we have nothing else to say, but it doesn't mean
444 * that the other side has nothing. It's even recommended to
445 * consume incoming data. [In testing context this ensures that
446 * alerts are passed on...]
447 */
448 timeout.tv_sec = 0;
449 timeout.tv_usec = 500000; /* some extreme round-trip */
450 do {
451 FD_ZERO(&readfds);
452 openssl_fdset(sock, &readfds);
453 } while (select(sock + 1, &readfds, NULL, NULL, &timeout) > 0
454 && readsocket(sock, sink, sizeof(sink)) > 0);
455
456 BIO_closesocket(sock);
457 } else {
458 if (naccept != -1)
459 naccept--;
460
461 i = (*cb)(asock, type, protocol, context);
462 }
463
464 if (i < 0 || naccept == 0) {
465 BIO_closesocket(asock);
466 ret = i;
467 break;
468 }
469 }
470 end:
471 # ifdef AF_UNIX
472 if (family == AF_UNIX)
473 unlink(host);
474 # endif
475 BIO_ADDR_free(ourpeer);
476 ourpeer = NULL;
477 return ret;
478 }
479
do_ssl_shutdown(SSL * ssl)480 void do_ssl_shutdown(SSL *ssl)
481 {
482 int ret;
483
484 do {
485 /* We only do unidirectional shutdown */
486 ret = SSL_shutdown(ssl);
487 if (ret < 0) {
488 switch (SSL_get_error(ssl, ret)) {
489 case SSL_ERROR_WANT_READ:
490 case SSL_ERROR_WANT_WRITE:
491 case SSL_ERROR_WANT_ASYNC:
492 case SSL_ERROR_WANT_ASYNC_JOB:
493 /* We just do busy waiting. Nothing clever */
494 continue;
495 }
496 ret = 0;
497 }
498 } while (ret < 0);
499 }
500
501 #endif /* OPENSSL_NO_SOCK */
502