1 /*
2 * Copyright 1995-2023 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 #define OPENSSL_SUPPRESS_DEPRECATED
11
12 #include <stdio.h>
13 #include <errno.h>
14 #include "bio_local.h"
15
16 #ifndef OPENSSL_NO_SOCK
17
18 typedef struct bio_accept_st {
19 int state;
20 int accept_family;
21 int bind_mode; /* Socket mode for BIO_listen */
22 int accepted_mode; /* Socket mode for BIO_accept (set on accepted sock) */
23 char *param_addr;
24 char *param_serv;
25
26 int accept_sock;
27
28 BIO_ADDRINFO *addr_first;
29 const BIO_ADDRINFO *addr_iter;
30 BIO_ADDR cache_accepting_addr; /* Useful if we asked for port 0 */
31 char *cache_accepting_name, *cache_accepting_serv;
32 BIO_ADDR cache_peer_addr;
33 char *cache_peer_name, *cache_peer_serv;
34
35 BIO *bio_chain;
36 } BIO_ACCEPT;
37
38 static int acpt_write(BIO *h, const char *buf, int num);
39 static int acpt_read(BIO *h, char *buf, int size);
40 static int acpt_puts(BIO *h, const char *str);
41 static long acpt_ctrl(BIO *h, int cmd, long arg1, void *arg2);
42 static int acpt_new(BIO *h);
43 static int acpt_free(BIO *data);
44 static int acpt_state(BIO *b, BIO_ACCEPT *c);
45 static void acpt_close_socket(BIO *data);
46 static BIO_ACCEPT *BIO_ACCEPT_new(void);
47 static void BIO_ACCEPT_free(BIO_ACCEPT *a);
48
49 # define ACPT_S_BEFORE 1
50 # define ACPT_S_GET_ADDR 2
51 # define ACPT_S_CREATE_SOCKET 3
52 # define ACPT_S_LISTEN 4
53 # define ACPT_S_ACCEPT 5
54 # define ACPT_S_OK 6
55
56 static const BIO_METHOD methods_acceptp = {
57 BIO_TYPE_ACCEPT,
58 "socket accept",
59 bwrite_conv,
60 acpt_write,
61 bread_conv,
62 acpt_read,
63 acpt_puts,
64 NULL, /* connect_gets, */
65 acpt_ctrl,
66 acpt_new,
67 acpt_free,
68 NULL, /* connect_callback_ctrl */
69 };
70
BIO_s_accept(void)71 const BIO_METHOD *BIO_s_accept(void)
72 {
73 return &methods_acceptp;
74 }
75
acpt_new(BIO * bi)76 static int acpt_new(BIO *bi)
77 {
78 BIO_ACCEPT *ba;
79
80 bi->init = 0;
81 bi->num = (int)INVALID_SOCKET;
82 bi->flags = 0;
83 if ((ba = BIO_ACCEPT_new()) == NULL)
84 return 0;
85 bi->ptr = (char *)ba;
86 ba->state = ACPT_S_BEFORE;
87 bi->shutdown = 1;
88 return 1;
89 }
90
BIO_ACCEPT_new(void)91 static BIO_ACCEPT *BIO_ACCEPT_new(void)
92 {
93 BIO_ACCEPT *ret;
94
95 if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL)
96 return NULL;
97 ret->accept_family = BIO_FAMILY_IPANY;
98 ret->accept_sock = (int)INVALID_SOCKET;
99 return ret;
100 }
101
BIO_ACCEPT_free(BIO_ACCEPT * a)102 static void BIO_ACCEPT_free(BIO_ACCEPT *a)
103 {
104 if (a == NULL)
105 return;
106 OPENSSL_free(a->param_addr);
107 OPENSSL_free(a->param_serv);
108 BIO_ADDRINFO_free(a->addr_first);
109 OPENSSL_free(a->cache_accepting_name);
110 OPENSSL_free(a->cache_accepting_serv);
111 OPENSSL_free(a->cache_peer_name);
112 OPENSSL_free(a->cache_peer_serv);
113 BIO_free(a->bio_chain);
114 OPENSSL_free(a);
115 }
116
acpt_close_socket(BIO * bio)117 static void acpt_close_socket(BIO *bio)
118 {
119 BIO_ACCEPT *c;
120
121 c = (BIO_ACCEPT *)bio->ptr;
122 if (c->accept_sock != (int)INVALID_SOCKET) {
123 shutdown(c->accept_sock, 2);
124 closesocket(c->accept_sock);
125 c->accept_sock = (int)INVALID_SOCKET;
126 bio->num = (int)INVALID_SOCKET;
127 }
128 }
129
acpt_free(BIO * a)130 static int acpt_free(BIO *a)
131 {
132 BIO_ACCEPT *data;
133
134 if (a == NULL)
135 return 0;
136 data = (BIO_ACCEPT *)a->ptr;
137
138 if (a->shutdown) {
139 acpt_close_socket(a);
140 BIO_ACCEPT_free(data);
141 a->ptr = NULL;
142 a->flags = 0;
143 a->init = 0;
144 }
145 return 1;
146 }
147
acpt_state(BIO * b,BIO_ACCEPT * c)148 static int acpt_state(BIO *b, BIO_ACCEPT *c)
149 {
150 BIO *bio = NULL, *dbio;
151 int s = -1, ret = -1;
152
153 for (;;) {
154 switch (c->state) {
155 case ACPT_S_BEFORE:
156 if (c->param_addr == NULL && c->param_serv == NULL) {
157 ERR_raise_data(ERR_LIB_BIO,
158 BIO_R_NO_ACCEPT_ADDR_OR_SERVICE_SPECIFIED,
159 "hostname=%s, service=%s",
160 c->param_addr, c->param_serv);
161 goto exit_loop;
162 }
163
164 /* Because we're starting a new bind, any cached name and serv
165 * are now obsolete and need to be cleaned out.
166 * QUESTION: should this be done in acpt_close_socket() instead?
167 */
168 OPENSSL_free(c->cache_accepting_name);
169 c->cache_accepting_name = NULL;
170 OPENSSL_free(c->cache_accepting_serv);
171 c->cache_accepting_serv = NULL;
172 OPENSSL_free(c->cache_peer_name);
173 c->cache_peer_name = NULL;
174 OPENSSL_free(c->cache_peer_serv);
175 c->cache_peer_serv = NULL;
176
177 c->state = ACPT_S_GET_ADDR;
178 break;
179
180 case ACPT_S_GET_ADDR:
181 {
182 int family = AF_UNSPEC;
183 switch (c->accept_family) {
184 case BIO_FAMILY_IPV6:
185 if (1) { /* This is a trick we use to avoid bit rot.
186 * at least the "else" part will always be
187 * compiled.
188 */
189 #if OPENSSL_USE_IPV6
190 family = AF_INET6;
191 } else {
192 #endif
193 ERR_raise(ERR_LIB_BIO, BIO_R_UNAVAILABLE_IP_FAMILY);
194 goto exit_loop;
195 }
196 break;
197 case BIO_FAMILY_IPV4:
198 family = AF_INET;
199 break;
200 case BIO_FAMILY_IPANY:
201 family = AF_UNSPEC;
202 break;
203 default:
204 ERR_raise(ERR_LIB_BIO, BIO_R_UNSUPPORTED_IP_FAMILY);
205 goto exit_loop;
206 }
207 if (BIO_lookup(c->param_addr, c->param_serv, BIO_LOOKUP_SERVER,
208 family, SOCK_STREAM, &c->addr_first) == 0)
209 goto exit_loop;
210 }
211 if (c->addr_first == NULL) {
212 ERR_raise(ERR_LIB_BIO, BIO_R_LOOKUP_RETURNED_NOTHING);
213 goto exit_loop;
214 }
215 c->addr_iter = c->addr_first;
216 c->state = ACPT_S_CREATE_SOCKET;
217 break;
218
219 case ACPT_S_CREATE_SOCKET:
220 ERR_set_mark();
221 s = BIO_socket(BIO_ADDRINFO_family(c->addr_iter),
222 BIO_ADDRINFO_socktype(c->addr_iter),
223 BIO_ADDRINFO_protocol(c->addr_iter), 0);
224 if (s == (int)INVALID_SOCKET) {
225 if ((c->addr_iter = BIO_ADDRINFO_next(c->addr_iter)) != NULL) {
226 /*
227 * if there are more addresses to try, do that first
228 */
229 ERR_pop_to_mark();
230 break;
231 }
232 ERR_clear_last_mark();
233 ERR_raise_data(ERR_LIB_SYS, get_last_socket_error(),
234 "calling socket(%s, %s)",
235 c->param_addr, c->param_serv);
236 ERR_raise(ERR_LIB_BIO, BIO_R_UNABLE_TO_CREATE_SOCKET);
237 goto exit_loop;
238 }
239 c->accept_sock = s;
240 b->num = s;
241 c->state = ACPT_S_LISTEN;
242 s = -1;
243 break;
244
245 case ACPT_S_LISTEN:
246 {
247 if (!BIO_listen(c->accept_sock,
248 BIO_ADDRINFO_address(c->addr_iter),
249 c->bind_mode)) {
250 BIO_closesocket(c->accept_sock);
251 goto exit_loop;
252 }
253 }
254
255 {
256 union BIO_sock_info_u info;
257
258 info.addr = &c->cache_accepting_addr;
259 if (!BIO_sock_info(c->accept_sock, BIO_SOCK_INFO_ADDRESS,
260 &info)) {
261 BIO_closesocket(c->accept_sock);
262 goto exit_loop;
263 }
264 }
265
266 c->cache_accepting_name =
267 BIO_ADDR_hostname_string(&c->cache_accepting_addr, 1);
268 c->cache_accepting_serv =
269 BIO_ADDR_service_string(&c->cache_accepting_addr, 1);
270 c->state = ACPT_S_ACCEPT;
271 s = -1;
272 ret = 1;
273 goto end;
274
275 case ACPT_S_ACCEPT:
276 if (b->next_bio != NULL) {
277 c->state = ACPT_S_OK;
278 break;
279 }
280 BIO_clear_retry_flags(b);
281 b->retry_reason = 0;
282
283 OPENSSL_free(c->cache_peer_name);
284 c->cache_peer_name = NULL;
285 OPENSSL_free(c->cache_peer_serv);
286 c->cache_peer_serv = NULL;
287
288 s = BIO_accept_ex(c->accept_sock, &c->cache_peer_addr,
289 c->accepted_mode);
290
291 /* If the returned socket is invalid, this might still be
292 * retryable
293 */
294 if (s < 0) {
295 if (BIO_sock_should_retry(s)) {
296 BIO_set_retry_special(b);
297 b->retry_reason = BIO_RR_ACCEPT;
298 goto end;
299 }
300 }
301
302 /* If it wasn't retryable, we fail */
303 if (s < 0) {
304 ret = s;
305 goto exit_loop;
306 }
307
308 bio = BIO_new_socket(s, BIO_CLOSE);
309 if (bio == NULL)
310 goto exit_loop;
311
312 BIO_set_callback_ex(bio, BIO_get_callback_ex(b));
313 #ifndef OPENSSL_NO_DEPRECATED_3_0
314 BIO_set_callback(bio, BIO_get_callback(b));
315 #endif
316 BIO_set_callback_arg(bio, BIO_get_callback_arg(b));
317 /*
318 * If the accept BIO has an bio_chain, we dup it and put the new
319 * socket at the end.
320 */
321 if (c->bio_chain != NULL) {
322 if ((dbio = BIO_dup_chain(c->bio_chain)) == NULL)
323 goto exit_loop;
324 if (!BIO_push(dbio, bio))
325 goto exit_loop;
326 bio = dbio;
327 }
328 if (BIO_push(b, bio) == NULL)
329 goto exit_loop;
330
331 c->cache_peer_name =
332 BIO_ADDR_hostname_string(&c->cache_peer_addr, 1);
333 c->cache_peer_serv =
334 BIO_ADDR_service_string(&c->cache_peer_addr, 1);
335 c->state = ACPT_S_OK;
336 bio = NULL;
337 ret = 1;
338 goto end;
339
340 case ACPT_S_OK:
341 if (b->next_bio == NULL) {
342 c->state = ACPT_S_ACCEPT;
343 break;
344 }
345 ret = 1;
346 goto end;
347
348 default:
349 ret = 0;
350 goto end;
351 }
352 }
353
354 exit_loop:
355 if (bio != NULL)
356 BIO_free(bio);
357 else if (s >= 0)
358 BIO_closesocket(s);
359 end:
360 return ret;
361 }
362
acpt_read(BIO * b,char * out,int outl)363 static int acpt_read(BIO *b, char *out, int outl)
364 {
365 int ret = 0;
366 BIO_ACCEPT *data;
367
368 BIO_clear_retry_flags(b);
369 data = (BIO_ACCEPT *)b->ptr;
370
371 while (b->next_bio == NULL) {
372 ret = acpt_state(b, data);
373 if (ret <= 0)
374 return ret;
375 }
376
377 ret = BIO_read(b->next_bio, out, outl);
378 BIO_copy_next_retry(b);
379 return ret;
380 }
381
acpt_write(BIO * b,const char * in,int inl)382 static int acpt_write(BIO *b, const char *in, int inl)
383 {
384 int ret;
385 BIO_ACCEPT *data;
386
387 BIO_clear_retry_flags(b);
388 data = (BIO_ACCEPT *)b->ptr;
389
390 while (b->next_bio == NULL) {
391 ret = acpt_state(b, data);
392 if (ret <= 0)
393 return ret;
394 }
395
396 ret = BIO_write(b->next_bio, in, inl);
397 BIO_copy_next_retry(b);
398 return ret;
399 }
400
acpt_ctrl(BIO * b,int cmd,long num,void * ptr)401 static long acpt_ctrl(BIO *b, int cmd, long num, void *ptr)
402 {
403 int *ip;
404 long ret = 1;
405 BIO_ACCEPT *data;
406 char **pp;
407
408 data = (BIO_ACCEPT *)b->ptr;
409
410 switch (cmd) {
411 case BIO_CTRL_RESET:
412 ret = 0;
413 data->state = ACPT_S_BEFORE;
414 acpt_close_socket(b);
415 BIO_ADDRINFO_free(data->addr_first);
416 data->addr_first = NULL;
417 b->flags = 0;
418 break;
419 case BIO_C_DO_STATE_MACHINE:
420 /* use this one to start the connection */
421 ret = (long)acpt_state(b, data);
422 break;
423 case BIO_C_SET_ACCEPT:
424 if (ptr != NULL) {
425 if (num == 0) {
426 char *hold_serv = data->param_serv;
427 /* We affect the hostname regardless. However, the input
428 * string might contain a host:service spec, so we must
429 * parse it, which might or might not affect the service
430 */
431 OPENSSL_free(data->param_addr);
432 data->param_addr = NULL;
433 ret = BIO_parse_hostserv(ptr,
434 &data->param_addr,
435 &data->param_serv,
436 BIO_PARSE_PRIO_SERV);
437 if (hold_serv != data->param_serv)
438 OPENSSL_free(hold_serv);
439 b->init = 1;
440 } else if (num == 1) {
441 OPENSSL_free(data->param_serv);
442 if ((data->param_serv = OPENSSL_strdup(ptr)) == NULL)
443 ret = 0;
444 else
445 b->init = 1;
446 } else if (num == 2) {
447 data->bind_mode |= BIO_SOCK_NONBLOCK;
448 } else if (num == 3) {
449 BIO_free(data->bio_chain);
450 data->bio_chain = (BIO *)ptr;
451 } else if (num == 4) {
452 data->accept_family = *(int *)ptr;
453 } else if (num == 5) {
454 data->bind_mode |= BIO_SOCK_TFO;
455 }
456 } else {
457 if (num == 2) {
458 data->bind_mode &= ~BIO_SOCK_NONBLOCK;
459 } else if (num == 5) {
460 data->bind_mode &= ~BIO_SOCK_TFO;
461 }
462 }
463 break;
464 case BIO_C_SET_NBIO:
465 if (num != 0)
466 data->accepted_mode |= BIO_SOCK_NONBLOCK;
467 else
468 data->accepted_mode &= ~BIO_SOCK_NONBLOCK;
469 break;
470 case BIO_C_SET_FD:
471 b->num = *((int *)ptr);
472 data->accept_sock = b->num;
473 data->state = ACPT_S_ACCEPT;
474 b->shutdown = (int)num;
475 b->init = 1;
476 break;
477 case BIO_C_GET_FD:
478 if (b->init) {
479 ip = (int *)ptr;
480 if (ip != NULL)
481 *ip = data->accept_sock;
482 ret = data->accept_sock;
483 } else
484 ret = -1;
485 break;
486 case BIO_C_GET_ACCEPT:
487 if (b->init) {
488 if (num == 0 && ptr != NULL) {
489 pp = (char **)ptr;
490 *pp = data->cache_accepting_name;
491 } else if (num == 1 && ptr != NULL) {
492 pp = (char **)ptr;
493 *pp = data->cache_accepting_serv;
494 } else if (num == 2 && ptr != NULL) {
495 pp = (char **)ptr;
496 *pp = data->cache_peer_name;
497 } else if (num == 3 && ptr != NULL) {
498 pp = (char **)ptr;
499 *pp = data->cache_peer_serv;
500 } else if (num == 4) {
501 switch (BIO_ADDRINFO_family(data->addr_iter)) {
502 #if OPENSSL_USE_IPV6
503 case AF_INET6:
504 ret = BIO_FAMILY_IPV6;
505 break;
506 #endif
507 case AF_INET:
508 ret = BIO_FAMILY_IPV4;
509 break;
510 case 0:
511 ret = data->accept_family;
512 break;
513 default:
514 ret = -1;
515 break;
516 }
517 } else
518 ret = -1;
519 } else
520 ret = -1;
521 break;
522 case BIO_CTRL_GET_CLOSE:
523 ret = b->shutdown;
524 break;
525 case BIO_CTRL_SET_CLOSE:
526 b->shutdown = (int)num;
527 break;
528 case BIO_CTRL_PENDING:
529 case BIO_CTRL_WPENDING:
530 ret = 0;
531 break;
532 case BIO_CTRL_FLUSH:
533 break;
534 case BIO_C_SET_BIND_MODE:
535 data->bind_mode = (int)num;
536 break;
537 case BIO_C_GET_BIND_MODE:
538 ret = (long)data->bind_mode;
539 break;
540 case BIO_CTRL_DUP:
541 break;
542 case BIO_CTRL_EOF:
543 if (b->next_bio == NULL)
544 ret = 0;
545 else
546 ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
547 break;
548 default:
549 ret = 0;
550 break;
551 }
552 return ret;
553 }
554
acpt_puts(BIO * bp,const char * str)555 static int acpt_puts(BIO *bp, const char *str)
556 {
557 int n, ret;
558
559 n = strlen(str);
560 ret = acpt_write(bp, str, n);
561 return ret;
562 }
563
BIO_new_accept(const char * str)564 BIO *BIO_new_accept(const char *str)
565 {
566 BIO *ret;
567
568 ret = BIO_new(BIO_s_accept());
569 if (ret == NULL)
570 return NULL;
571 if (BIO_set_accept_name(ret, str) > 0)
572 return ret;
573 BIO_free(ret);
574 return NULL;
575 }
576
577 #endif
578
