1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23 #include "curl_setup.h"
24
25 #ifdef HAVE_NETINET_IN_H
26 #include <netinet/in.h>
27 #endif
28 #ifdef HAVE_NETDB_H
29 #include <netdb.h>
30 #endif
31 #ifdef HAVE_ARPA_INET_H
32 #include <arpa/inet.h>
33 #endif
34 #ifdef __VMS
35 #include <in.h>
36 #include <inet.h>
37 #endif
38
39 #if defined(USE_THREADS_POSIX)
40 # ifdef HAVE_PTHREAD_H
41 # include <pthread.h>
42 # endif
43 #elif defined(USE_THREADS_WIN32)
44 # ifdef HAVE_PROCESS_H
45 # include <process.h>
46 # endif
47 #endif
48
49 #if (defined(NETWARE) && defined(__NOVELL_LIBC__))
50 #undef in_addr_t
51 #define in_addr_t unsigned long
52 #endif
53
54 #ifdef HAVE_GETADDRINFO
55 # define RESOLVER_ENOMEM EAI_MEMORY
56 #else
57 # define RESOLVER_ENOMEM ENOMEM
58 #endif
59
60 #include "urldata.h"
61 #include "sendf.h"
62 #include "hostip.h"
63 #include "hash.h"
64 #include "share.h"
65 #include "strerror.h"
66 #include "url.h"
67 #include "multiif.h"
68 #include "inet_pton.h"
69 #include "inet_ntop.h"
70 #include "curl_threads.h"
71 #include "connect.h"
72 #include "curl_printf.h"
73 #include "curl_memory.h"
74
75 /* The last #include file should be: */
76 #include "memdebug.h"
77
78 /***********************************************************************
79 * Only for threaded name resolves builds
80 **********************************************************************/
81 #ifdef CURLRES_THREADED
82
83 /*
84 * Curl_resolver_global_init()
85 * Called from curl_global_init() to initialize global resolver environment.
86 * Does nothing here.
87 */
Curl_resolver_global_init(void)88 int Curl_resolver_global_init(void)
89 {
90 return CURLE_OK;
91 }
92
93 /*
94 * Curl_resolver_global_cleanup()
95 * Called from curl_global_cleanup() to destroy global resolver environment.
96 * Does nothing here.
97 */
Curl_resolver_global_cleanup(void)98 void Curl_resolver_global_cleanup(void)
99 {
100 }
101
102 /*
103 * Curl_resolver_init()
104 * Called from curl_easy_init() -> Curl_open() to initialize resolver
105 * URL-state specific environment ('resolver' member of the UrlState
106 * structure). Does nothing here.
107 */
Curl_resolver_init(void ** resolver)108 CURLcode Curl_resolver_init(void **resolver)
109 {
110 (void)resolver;
111 return CURLE_OK;
112 }
113
114 /*
115 * Curl_resolver_cleanup()
116 * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver
117 * URL-state specific environment ('resolver' member of the UrlState
118 * structure). Does nothing here.
119 */
Curl_resolver_cleanup(void * resolver)120 void Curl_resolver_cleanup(void *resolver)
121 {
122 (void)resolver;
123 }
124
125 /*
126 * Curl_resolver_duphandle()
127 * Called from curl_easy_duphandle() to duplicate resolver URL state-specific
128 * environment ('resolver' member of the UrlState structure). Does nothing
129 * here.
130 */
Curl_resolver_duphandle(void ** to,void * from)131 int Curl_resolver_duphandle(void **to, void *from)
132 {
133 (void)to;
134 (void)from;
135 return CURLE_OK;
136 }
137
138 static void destroy_async_data(struct Curl_async *);
139
140 /*
141 * Cancel all possibly still on-going resolves for this connection.
142 */
Curl_resolver_cancel(struct connectdata * conn)143 void Curl_resolver_cancel(struct connectdata *conn)
144 {
145 destroy_async_data(&conn->async);
146 }
147
148 /* This function is used to init a threaded resolve */
149 static bool init_resolve_thread(struct connectdata *conn,
150 const char *hostname, int port,
151 const struct addrinfo *hints);
152
153
154 /* Data for synchronization between resolver thread and its parent */
155 struct thread_sync_data {
156 curl_mutex_t * mtx;
157 int done;
158
159 char * hostname; /* hostname to resolve, Curl_async.hostname
160 duplicate */
161 int port;
162 int sock_error;
163 Curl_addrinfo *res;
164 #ifdef HAVE_GETADDRINFO
165 struct addrinfo hints;
166 #endif
167 struct thread_data *td; /* for thread-self cleanup */
168 };
169
170 struct thread_data {
171 curl_thread_t thread_hnd;
172 unsigned int poll_interval;
173 long interval_end;
174 struct thread_sync_data tsd;
175 };
176
conn_thread_sync_data(struct connectdata * conn)177 static struct thread_sync_data *conn_thread_sync_data(struct connectdata *conn)
178 {
179 return &(((struct thread_data *)conn->async.os_specific)->tsd);
180 }
181
182 #define CONN_THREAD_SYNC_DATA(conn) &(((conn)->async.os_specific)->tsd);
183
184 /* Destroy resolver thread synchronization data */
185 static
destroy_thread_sync_data(struct thread_sync_data * tsd)186 void destroy_thread_sync_data(struct thread_sync_data * tsd)
187 {
188 if(tsd->mtx) {
189 Curl_mutex_destroy(tsd->mtx);
190 free(tsd->mtx);
191 }
192
193 free(tsd->hostname);
194
195 if(tsd->res)
196 Curl_freeaddrinfo(tsd->res);
197
198 memset(tsd, 0, sizeof(*tsd));
199 }
200
201 /* Initialize resolver thread synchronization data */
202 static
init_thread_sync_data(struct thread_data * td,const char * hostname,int port,const struct addrinfo * hints)203 int init_thread_sync_data(struct thread_data * td,
204 const char * hostname,
205 int port,
206 const struct addrinfo *hints)
207 {
208 struct thread_sync_data *tsd = &td->tsd;
209
210 memset(tsd, 0, sizeof(*tsd));
211
212 tsd->td = td;
213 tsd->port = port;
214 #ifdef HAVE_GETADDRINFO
215 DEBUGASSERT(hints);
216 tsd->hints = *hints;
217 #else
218 (void) hints;
219 #endif
220
221 tsd->mtx = malloc(sizeof(curl_mutex_t));
222 if(tsd->mtx == NULL)
223 goto err_exit;
224
225 Curl_mutex_init(tsd->mtx);
226
227 tsd->sock_error = CURL_ASYNC_SUCCESS;
228
229 /* Copying hostname string because original can be destroyed by parent
230 * thread during gethostbyname execution.
231 */
232 tsd->hostname = strdup(hostname);
233 if(!tsd->hostname)
234 goto err_exit;
235
236 return 1;
237
238 err_exit:
239 /* Memory allocation failed */
240 destroy_thread_sync_data(tsd);
241 return 0;
242 }
243
getaddrinfo_complete(struct connectdata * conn)244 static int getaddrinfo_complete(struct connectdata *conn)
245 {
246 struct thread_sync_data *tsd = conn_thread_sync_data(conn);
247 int rc;
248
249 rc = Curl_addrinfo_callback(conn, tsd->sock_error, tsd->res);
250 /* The tsd->res structure has been copied to async.dns and perhaps the DNS
251 cache. Set our copy to NULL so destroy_thread_sync_data doesn't free it.
252 */
253 tsd->res = NULL;
254
255 return rc;
256 }
257
258
259 #ifdef HAVE_GETADDRINFO
260
261 /*
262 * getaddrinfo_thread() resolves a name and then exits.
263 *
264 * For builds without ARES, but with ENABLE_IPV6, create a resolver thread
265 * and wait on it.
266 */
getaddrinfo_thread(void * arg)267 static unsigned int CURL_STDCALL getaddrinfo_thread (void *arg)
268 {
269 struct thread_sync_data *tsd = (struct thread_sync_data*)arg;
270 struct thread_data *td = tsd->td;
271 char service[12];
272 int rc;
273
274 snprintf(service, sizeof(service), "%d", tsd->port);
275
276 rc = Curl_getaddrinfo_ex(tsd->hostname, service, &tsd->hints, &tsd->res);
277
278 if(rc != 0) {
279 tsd->sock_error = SOCKERRNO?SOCKERRNO:rc;
280 if(tsd->sock_error == 0)
281 tsd->sock_error = RESOLVER_ENOMEM;
282 }
283
284 Curl_mutex_acquire(tsd->mtx);
285 if(tsd->done) {
286 /* too late, gotta clean up the mess */
287 Curl_mutex_release(tsd->mtx);
288 destroy_thread_sync_data(tsd);
289 free(td);
290 }
291 else {
292 tsd->done = 1;
293 Curl_mutex_release(tsd->mtx);
294 }
295
296 return 0;
297 }
298
299 #else /* HAVE_GETADDRINFO */
300
301 /*
302 * gethostbyname_thread() resolves a name and then exits.
303 */
gethostbyname_thread(void * arg)304 static unsigned int CURL_STDCALL gethostbyname_thread (void *arg)
305 {
306 struct thread_sync_data *tsd = (struct thread_sync_data *)arg;
307 struct thread_data *td = tsd->td;
308
309 tsd->res = Curl_ipv4_resolve_r(tsd->hostname, tsd->port);
310
311 if(!tsd->res) {
312 tsd->sock_error = SOCKERRNO;
313 if(tsd->sock_error == 0)
314 tsd->sock_error = RESOLVER_ENOMEM;
315 }
316
317 Curl_mutex_acquire(tsd->mtx);
318 if(tsd->done) {
319 /* too late, gotta clean up the mess */
320 Curl_mutex_release(tsd->mtx);
321 destroy_thread_sync_data(tsd);
322 free(td);
323 }
324 else {
325 tsd->done = 1;
326 Curl_mutex_release(tsd->mtx);
327 }
328
329 return 0;
330 }
331
332 #endif /* HAVE_GETADDRINFO */
333
334 /*
335 * destroy_async_data() cleans up async resolver data and thread handle.
336 */
destroy_async_data(struct Curl_async * async)337 static void destroy_async_data (struct Curl_async *async)
338 {
339 if(async->os_specific) {
340 struct thread_data *td = (struct thread_data*) async->os_specific;
341 int done;
342
343 /*
344 * if the thread is still blocking in the resolve syscall, detach it and
345 * let the thread do the cleanup...
346 */
347 Curl_mutex_acquire(td->tsd.mtx);
348 done = td->tsd.done;
349 td->tsd.done = 1;
350 Curl_mutex_release(td->tsd.mtx);
351
352 if(!done) {
353 Curl_thread_destroy(td->thread_hnd);
354 }
355 else {
356 if(td->thread_hnd != curl_thread_t_null)
357 Curl_thread_join(&td->thread_hnd);
358
359 destroy_thread_sync_data(&td->tsd);
360
361 free(async->os_specific);
362 }
363 }
364 async->os_specific = NULL;
365
366 free(async->hostname);
367 async->hostname = NULL;
368 }
369
370 /*
371 * init_resolve_thread() starts a new thread that performs the actual
372 * resolve. This function returns before the resolve is done.
373 *
374 * Returns FALSE in case of failure, otherwise TRUE.
375 */
init_resolve_thread(struct connectdata * conn,const char * hostname,int port,const struct addrinfo * hints)376 static bool init_resolve_thread (struct connectdata *conn,
377 const char *hostname, int port,
378 const struct addrinfo *hints)
379 {
380 struct thread_data *td = calloc(1, sizeof(struct thread_data));
381 int err = RESOLVER_ENOMEM;
382
383 conn->async.os_specific = (void*) td;
384 if(!td)
385 goto err_exit;
386
387 conn->async.port = port;
388 conn->async.done = FALSE;
389 conn->async.status = 0;
390 conn->async.dns = NULL;
391 td->thread_hnd = curl_thread_t_null;
392
393 if(!init_thread_sync_data(td, hostname, port, hints))
394 goto err_exit;
395
396 free(conn->async.hostname);
397 conn->async.hostname = strdup(hostname);
398 if(!conn->async.hostname)
399 goto err_exit;
400
401 #ifdef HAVE_GETADDRINFO
402 td->thread_hnd = Curl_thread_create(getaddrinfo_thread, &td->tsd);
403 #else
404 td->thread_hnd = Curl_thread_create(gethostbyname_thread, &td->tsd);
405 #endif
406
407 if(!td->thread_hnd) {
408 #ifndef _WIN32_WCE
409 err = errno;
410 #endif
411 goto err_exit;
412 }
413
414 return TRUE;
415
416 err_exit:
417 destroy_async_data(&conn->async);
418
419 SET_ERRNO(err);
420
421 return FALSE;
422 }
423
424 /*
425 * resolver_error() calls failf() with the appropriate message after a resolve
426 * error
427 */
428
resolver_error(struct connectdata * conn)429 static CURLcode resolver_error(struct connectdata *conn)
430 {
431 const char *host_or_proxy;
432 CURLcode result;
433
434 if(conn->bits.httpproxy) {
435 host_or_proxy = "proxy";
436 result = CURLE_COULDNT_RESOLVE_PROXY;
437 }
438 else {
439 host_or_proxy = "host";
440 result = CURLE_COULDNT_RESOLVE_HOST;
441 }
442
443 failf(conn->data, "Could not resolve %s: %s", host_or_proxy,
444 conn->async.hostname);
445
446 return result;
447 }
448
449 /*
450 * Curl_resolver_wait_resolv()
451 *
452 * waits for a resolve to finish. This function should be avoided since using
453 * this risk getting the multi interface to "hang".
454 *
455 * If 'entry' is non-NULL, make it point to the resolved dns entry
456 *
457 * This is the version for resolves-in-a-thread.
458 */
Curl_resolver_wait_resolv(struct connectdata * conn,struct Curl_dns_entry ** entry)459 CURLcode Curl_resolver_wait_resolv(struct connectdata *conn,
460 struct Curl_dns_entry **entry)
461 {
462 struct thread_data *td = (struct thread_data*) conn->async.os_specific;
463 CURLcode result = CURLE_OK;
464
465 DEBUGASSERT(conn && td);
466
467 /* wait for the thread to resolve the name */
468 if(Curl_thread_join(&td->thread_hnd))
469 result = getaddrinfo_complete(conn);
470 else
471 DEBUGASSERT(0);
472
473 conn->async.done = TRUE;
474
475 if(entry)
476 *entry = conn->async.dns;
477
478 if(!conn->async.dns)
479 /* a name was not resolved, report error */
480 result = resolver_error(conn);
481
482 destroy_async_data(&conn->async);
483
484 if(!conn->async.dns)
485 connclose(conn, "asynch resolve failed");
486
487 return result;
488 }
489
490 /*
491 * Curl_resolver_is_resolved() is called repeatedly to check if a previous
492 * name resolve request has completed. It should also make sure to time-out if
493 * the operation seems to take too long.
494 */
Curl_resolver_is_resolved(struct connectdata * conn,struct Curl_dns_entry ** entry)495 CURLcode Curl_resolver_is_resolved(struct connectdata *conn,
496 struct Curl_dns_entry **entry)
497 {
498 struct SessionHandle *data = conn->data;
499 struct thread_data *td = (struct thread_data*) conn->async.os_specific;
500 int done = 0;
501
502 *entry = NULL;
503
504 if(!td) {
505 DEBUGASSERT(td);
506 return CURLE_COULDNT_RESOLVE_HOST;
507 }
508
509 Curl_mutex_acquire(td->tsd.mtx);
510 done = td->tsd.done;
511 Curl_mutex_release(td->tsd.mtx);
512
513 if(done) {
514 getaddrinfo_complete(conn);
515
516 if(!conn->async.dns) {
517 CURLcode result = resolver_error(conn);
518 destroy_async_data(&conn->async);
519 return result;
520 }
521 destroy_async_data(&conn->async);
522 *entry = conn->async.dns;
523 }
524 else {
525 /* poll for name lookup done with exponential backoff up to 250ms */
526 long elapsed = Curl_tvdiff(Curl_tvnow(), data->progress.t_startsingle);
527 if(elapsed < 0)
528 elapsed = 0;
529
530 if(td->poll_interval == 0)
531 /* Start at 1ms poll interval */
532 td->poll_interval = 1;
533 else if(elapsed >= td->interval_end)
534 /* Back-off exponentially if last interval expired */
535 td->poll_interval *= 2;
536
537 if(td->poll_interval > 250)
538 td->poll_interval = 250;
539
540 td->interval_end = elapsed + td->poll_interval;
541 Curl_expire(conn->data, td->poll_interval);
542 }
543
544 return CURLE_OK;
545 }
546
Curl_resolver_getsock(struct connectdata * conn,curl_socket_t * socks,int numsocks)547 int Curl_resolver_getsock(struct connectdata *conn,
548 curl_socket_t *socks,
549 int numsocks)
550 {
551 (void)conn;
552 (void)socks;
553 (void)numsocks;
554 return 0;
555 }
556
557 #ifndef HAVE_GETADDRINFO
558 /*
559 * Curl_getaddrinfo() - for platforms without getaddrinfo
560 */
Curl_resolver_getaddrinfo(struct connectdata * conn,const char * hostname,int port,int * waitp)561 Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
562 const char *hostname,
563 int port,
564 int *waitp)
565 {
566 struct in_addr in;
567
568 *waitp = 0; /* default to synchronous response */
569
570 if(Curl_inet_pton(AF_INET, hostname, &in) > 0)
571 /* This is a dotted IP address 123.123.123.123-style */
572 return Curl_ip2addr(AF_INET, &in, hostname, port);
573
574 /* fire up a new resolver thread! */
575 if(init_resolve_thread(conn, hostname, port, NULL)) {
576 *waitp = 1; /* expect asynchronous response */
577 return NULL;
578 }
579
580 /* fall-back to blocking version */
581 return Curl_ipv4_resolve_r(hostname, port);
582 }
583
584 #else /* !HAVE_GETADDRINFO */
585
586 /*
587 * Curl_resolver_getaddrinfo() - for getaddrinfo
588 */
Curl_resolver_getaddrinfo(struct connectdata * conn,const char * hostname,int port,int * waitp)589 Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn,
590 const char *hostname,
591 int port,
592 int *waitp)
593 {
594 struct addrinfo hints;
595 struct in_addr in;
596 Curl_addrinfo *res;
597 int error;
598 char sbuf[12];
599 int pf = PF_INET;
600 #ifdef CURLRES_IPV6
601 struct in6_addr in6;
602 #endif /* CURLRES_IPV6 */
603
604 *waitp = 0; /* default to synchronous response */
605
606 /* First check if this is an IPv4 address string */
607 if(Curl_inet_pton(AF_INET, hostname, &in) > 0)
608 /* This is a dotted IP address 123.123.123.123-style */
609 return Curl_ip2addr(AF_INET, &in, hostname, port);
610
611 #ifdef CURLRES_IPV6
612 /* check if this is an IPv6 address string */
613 if(Curl_inet_pton (AF_INET6, hostname, &in6) > 0)
614 /* This is an IPv6 address literal */
615 return Curl_ip2addr(AF_INET6, &in6, hostname, port);
616
617 /*
618 * Check if a limited name resolve has been requested.
619 */
620 switch(conn->ip_version) {
621 case CURL_IPRESOLVE_V4:
622 pf = PF_INET;
623 break;
624 case CURL_IPRESOLVE_V6:
625 pf = PF_INET6;
626 break;
627 default:
628 pf = PF_UNSPEC;
629 break;
630 }
631
632 if((pf != PF_INET) && !Curl_ipv6works())
633 /* The stack seems to be a non-IPv6 one */
634 pf = PF_INET;
635
636 #endif /* CURLRES_IPV6 */
637
638 memset(&hints, 0, sizeof(hints));
639 hints.ai_family = pf;
640 hints.ai_socktype = conn->socktype;
641
642 snprintf(sbuf, sizeof(sbuf), "%d", port);
643
644 /* fire up a new resolver thread! */
645 if(init_resolve_thread(conn, hostname, port, &hints)) {
646 *waitp = 1; /* expect asynchronous response */
647 return NULL;
648 }
649
650 /* fall-back to blocking version */
651 infof(conn->data, "init_resolve_thread() failed for %s; %s\n",
652 hostname, Curl_strerror(conn, ERRNO));
653
654 error = Curl_getaddrinfo_ex(hostname, sbuf, &hints, &res);
655 if(error) {
656 infof(conn->data, "getaddrinfo() failed for %s:%d; %s\n",
657 hostname, port, Curl_strerror(conn, SOCKERRNO));
658 return NULL;
659 }
660 return res;
661 }
662
663 #endif /* !HAVE_GETADDRINFO */
664
Curl_set_dns_servers(struct SessionHandle * data,char * servers)665 CURLcode Curl_set_dns_servers(struct SessionHandle *data,
666 char *servers)
667 {
668 (void)data;
669 (void)servers;
670 return CURLE_NOT_BUILT_IN;
671
672 }
673
Curl_set_dns_interface(struct SessionHandle * data,const char * interf)674 CURLcode Curl_set_dns_interface(struct SessionHandle *data,
675 const char *interf)
676 {
677 (void)data;
678 (void)interf;
679 return CURLE_NOT_BUILT_IN;
680 }
681
Curl_set_dns_local_ip4(struct SessionHandle * data,const char * local_ip4)682 CURLcode Curl_set_dns_local_ip4(struct SessionHandle *data,
683 const char *local_ip4)
684 {
685 (void)data;
686 (void)local_ip4;
687 return CURLE_NOT_BUILT_IN;
688 }
689
Curl_set_dns_local_ip6(struct SessionHandle * data,const char * local_ip6)690 CURLcode Curl_set_dns_local_ip6(struct SessionHandle *data,
691 const char *local_ip6)
692 {
693 (void)data;
694 (void)local_ip6;
695 return CURLE_NOT_BUILT_IN;
696 }
697
698 #endif /* CURLRES_THREADED */
699