1 /* Host name resolution and matching.
2 Copyright (C) 1995, 1996, 1997, 2000, 2001 Free Software Foundation, Inc.
4 This file is part of GNU Wget.
6 GNU Wget is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 GNU Wget is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with Wget; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 In addition, as a special exception, the Free Software Foundation
21 gives permission to link the code of its release of Wget with the
22 OpenSSL project's "OpenSSL" library (or with modified versions of it
23 that use the same license as the "OpenSSL" library), and distribute
24 the linked executables. You must obey the GNU General Public License
25 in all respects for all of the code used other than "OpenSSL". If you
26 modify this file, you may extend this exception to your version of the
27 file, but you are not obligated to do so. If you do not wish to do
28 so, delete this exception statement from your version. */
44 #include <sys/types.h>
48 # define SET_H_ERRNO(err) WSASetLastError (err)
50 # include <sys/socket.h>
51 # include <netinet/in.h>
53 # include <arpa/inet.h>
56 # define SET_H_ERRNO(err) ((void)(h_errno = (err)))
60 # define NO_ADDRESS NO_DATA
81 /* Mapping between known hosts and to lists of their addresses. */
83 static struct hash_table *host_name_addresses_map;
85 /* Lists of addresses. This should eventually be extended to handle
89 int count; /* number of adrresses */
90 ip_address *addresses; /* pointer to the string of addresses */
92 int faulty; /* number of addresses known not to work. */
93 int connected; /* whether we were able to connect to
94 one of the addresses in the list,
97 int refcount; /* reference count; when it drops to
98 0, the entry is freed. */
101 /* Get the bounds of the address list. */
104 address_list_get_bounds (const struct address_list *al, int *start, int *end)
110 /* Return a pointer to the address at position POS. */
113 address_list_address_at (const struct address_list *al, int pos)
115 assert (pos >= al->faulty && pos < al->count);
116 return al->addresses + pos;
119 /* Return 1 if IP is one of the addresses in AL. */
122 address_list_find (const struct address_list *al, const ip_address *ip)
128 for (i = 0; i < al->count; i++)
130 ip_address *cur = al->addresses + i;
131 if (cur->type == IPV4_ADDRESS
132 && (ADDRESS_IPV4_IN_ADDR (cur).s_addr
134 ADDRESS_IPV4_IN_ADDR (ip).s_addr))
140 for (i = 0; i < al->count; i++)
142 ip_address *cur = al->addresses + i;
143 if (cur->type == IPV6_ADDRESS
144 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
145 && ADDRESS_IPV6_SCOPE (cur) == ADDRESS_IPV6_SCOPE (ip)
147 && IN6_ARE_ADDR_EQUAL (&ADDRESS_IPV6_IN6_ADDR (cur),
148 &ADDRESS_IPV6_IN6_ADDR (ip)))
152 #endif /* ENABLE_IPV6 */
159 /* Mark the INDEXth element of AL as faulty, so that the next time
160 this address list is used, the faulty element will be skipped. */
163 address_list_set_faulty (struct address_list *al, int index)
165 /* We assume that the address list is traversed in order, so that a
166 "faulty" attempt is always preceded with all-faulty addresses,
167 and this is how Wget uses it. */
168 assert (index == al->faulty);
171 if (al->faulty >= al->count)
172 /* All addresses have been proven faulty. Since there's not much
173 sense in returning the user an empty address list the next
174 time, we'll rather make them all clean, so that they can be
179 /* Set the "connected" flag to true. This flag used by connect.c to
180 see if the host perhaps needs to be resolved again. */
183 address_list_set_connected (struct address_list *al)
188 /* Return the value of the "connected" flag. */
191 address_list_connected_p (const struct address_list *al)
193 return al->connected;
198 /* Create an address_list from the addresses in the given struct
201 static struct address_list *
202 address_list_from_addrinfo (const struct addrinfo *ai)
204 struct address_list *al;
205 const struct addrinfo *ptr;
210 for (ptr = ai; ptr != NULL ; ptr = ptr->ai_next)
211 if (ptr->ai_family == AF_INET || ptr->ai_family == AF_INET6)
216 al = xnew0 (struct address_list);
217 al->addresses = xnew_array (ip_address, cnt);
222 for (ptr = ai; ptr != NULL; ptr = ptr->ai_next)
223 if (ptr->ai_family == AF_INET6)
225 const struct sockaddr_in6 *sin6 =
226 (const struct sockaddr_in6 *)ptr->ai_addr;
227 ip->type = IPV6_ADDRESS;
228 ADDRESS_IPV6_IN6_ADDR (ip) = sin6->sin6_addr;
229 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
230 ADDRESS_IPV6_SCOPE (ip) = sin6->sin6_scope_id;
234 else if (ptr->ai_family == AF_INET)
236 const struct sockaddr_in *sin =
237 (const struct sockaddr_in *)ptr->ai_addr;
238 ip->type = IPV4_ADDRESS;
239 ADDRESS_IPV4_IN_ADDR (ip) = sin->sin_addr;
242 assert (ip - al->addresses == cnt);
246 #else /* not ENABLE_IPV6 */
248 /* Create an address_list from a NULL-terminated vector of IPv4
249 addresses. This kind of vector is returned by gethostbyname. */
251 static struct address_list *
252 address_list_from_ipv4_addresses (char **vec)
255 struct address_list *al = xnew0 (struct address_list);
262 al->addresses = xnew_array (ip_address, count);
266 for (i = 0; i < count; i++)
268 ip_address *ip = &al->addresses[i];
269 ip->type = IPV4_ADDRESS;
270 memcpy (ADDRESS_IPV4_DATA (ip), vec[i], 4);
276 #endif /* not ENABLE_IPV6 */
279 address_list_delete (struct address_list *al)
281 xfree (al->addresses);
285 /* Mark the address list as being no longer in use. This will reduce
286 its reference count which will cause the list to be freed when the
290 address_list_release (struct address_list *al)
293 DEBUGP (("Releasing %p (new refcount %d).\n", al, al->refcount));
294 if (al->refcount <= 0)
296 DEBUGP (("Deleting unused %p.\n", al));
297 address_list_delete (al);
301 /* Versions of gethostbyname and getaddrinfo that support timeout. */
305 struct ghbnwt_context {
306 const char *host_name;
307 struct hostent *hptr;
311 gethostbyname_with_timeout_callback (void *arg)
313 struct ghbnwt_context *ctx = (struct ghbnwt_context *)arg;
314 ctx->hptr = gethostbyname (ctx->host_name);
317 /* Just like gethostbyname, except it times out after TIMEOUT seconds.
318 In case of timeout, NULL is returned and errno is set to ETIMEDOUT.
319 The function makes sure that when NULL is returned for reasons
320 other than timeout, errno is reset. */
322 static struct hostent *
323 gethostbyname_with_timeout (const char *host_name, double timeout)
325 struct ghbnwt_context ctx;
326 ctx.host_name = host_name;
327 if (run_with_timeout (timeout, gethostbyname_with_timeout_callback, &ctx))
329 SET_H_ERRNO (HOST_NOT_FOUND);
338 /* Print error messages for host errors. */
340 host_errstr (int error)
342 /* Can't use switch since some of these constants can be equal,
343 which makes the compiler complain about duplicate case
345 if (error == HOST_NOT_FOUND
346 || error == NO_RECOVERY
348 || error == NO_ADDRESS)
349 return _("Unknown host");
350 else if (error == TRY_AGAIN)
351 /* Message modeled after what gai_strerror returns in similar
353 return _("Temporary failure in name resolution");
355 return _("Unknown error");
358 #else /* ENABLE_IPV6 */
360 struct gaiwt_context {
363 const struct addrinfo *hints;
364 struct addrinfo **res;
369 getaddrinfo_with_timeout_callback (void *arg)
371 struct gaiwt_context *ctx = (struct gaiwt_context *)arg;
372 ctx->exit_code = getaddrinfo (ctx->node, ctx->service, ctx->hints, ctx->res);
375 /* Just like getaddrinfo, except it times out after TIMEOUT seconds.
376 In case of timeout, the EAI_SYSTEM error code is returned and errno
377 is set to ETIMEDOUT. */
380 getaddrinfo_with_timeout (const char *node, const char *service,
381 const struct addrinfo *hints, struct addrinfo **res,
384 struct gaiwt_context ctx;
386 ctx.service = service;
390 if (run_with_timeout (timeout, getaddrinfo_with_timeout_callback, &ctx))
395 return ctx.exit_code;
398 #endif /* ENABLE_IPV6 */
400 /* Pretty-print ADDR. When compiled without IPv6, this is the same as
401 inet_ntoa. With IPv6, it either prints an IPv6 address or an IPv4
405 pretty_print_address (const ip_address *addr)
410 return inet_ntoa (ADDRESS_IPV4_IN_ADDR (addr));
414 static char buf[128];
415 inet_ntop (AF_INET6, &ADDRESS_IPV6_IN6_ADDR (addr), buf, sizeof (buf));
417 #ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
419 /* append "%SCOPE_ID" for all ?non-global? addresses */
420 char *p = buf + strlen (buf);
422 number_to_string (p, ADDRESS_IPV6_SCOPE (addr));
426 buf[sizeof (buf) - 1] = '\0';
435 /* Add host name HOST with the address ADDR_TEXT to the cache.
436 ADDR_LIST is a NULL-terminated list of addresses, as in struct
440 cache_host_lookup (const char *host, struct address_list *al)
442 if (!host_name_addresses_map)
443 host_name_addresses_map = make_nocase_string_hash_table (0);
446 hash_table_put (host_name_addresses_map, xstrdup_lower (host), al);
452 debug_logprintf ("Caching %s =>", host);
453 for (i = 0; i < al->count; i++)
454 debug_logprintf (" %s", pretty_print_address (al->addresses + i));
455 debug_logprintf ("\n");
460 /* Remove HOST from Wget's DNS cache. Does nothing is HOST is not in
464 forget_host_lookup (const char *host)
466 struct address_list *al = hash_table_get (host_name_addresses_map, host);
469 address_list_release (al);
470 hash_table_remove (host_name_addresses_map, host);
474 /* Look up HOST in DNS and return a list of IP addresses.
476 This function caches its result so that, if the same host is passed
477 the second time, the addresses are returned without the DNS lookup.
478 If you want to force lookup, call forget_host_lookup() prior to
479 this function, or set opt.dns_cache to 0 to globally disable
482 If SILENT is non-zero, progress messages are not printed. */
484 struct address_list *
485 lookup_host (const char *host, int silent)
487 struct address_list *al = NULL;
490 /* If we're not using getaddrinfo, first check if HOST names a
491 numeric IPv4 address. gethostbyname is not required to accept
492 dotted-decimal IPv4 addresses, and some older implementations
493 (e.g. the Ultrix one) indeed didn't. */
495 uint32_t addr_ipv4 = (uint32_t)inet_addr (host);
496 if (addr_ipv4 != (uint32_t) -1)
498 /* No need to cache host->addr relation, just return the
501 vec[0] = (char *)&addr_ipv4;
503 return address_list_from_ipv4_addresses (vec);
508 /* Try to find the host in the cache. */
510 if (host_name_addresses_map)
512 al = hash_table_get (host_name_addresses_map, host);
515 DEBUGP (("Found %s in host_name_addresses_map (%p)\n", host, al));
521 /* No luck with the cache; resolve the host name. */
524 logprintf (LOG_VERBOSE, _("Resolving %s... "), host);
529 struct addrinfo hints, *res;
532 hints.ai_socktype = SOCK_STREAM;
533 hints.ai_family = AF_UNSPEC; /* #### should look at opt.ipv4_only
537 err = getaddrinfo_with_timeout (host, NULL, &hints, &res, opt.dns_timeout);
538 if (err != 0 || res == NULL)
541 logprintf (LOG_VERBOSE, _("failed: %s.\n"),
542 err != EAI_SYSTEM ? gai_strerror (err) : strerror (errno));
545 al = address_list_from_addrinfo (res);
549 logprintf (LOG_VERBOSE, _("failed: No IPv4/IPv6 addresses.\n"));
555 struct hostent *hptr = gethostbyname_with_timeout (host, opt.dns_timeout);
560 if (errno != ETIMEDOUT)
561 logprintf (LOG_VERBOSE, _("failed: %s.\n"),
562 host_errstr (h_errno));
564 logputs (LOG_VERBOSE, _("failed: timed out.\n"));
568 /* Do older systems have h_addr_list? */
569 al = address_list_from_ipv4_addresses (hptr->h_addr_list);
573 /* Print the addresses determined by DNS lookup, but no more than
578 int printmax = al->count <= 3 ? al->count : 3;
579 for (i = 0; i < printmax; i++)
581 logprintf (LOG_VERBOSE, "%s",
582 pretty_print_address (al->addresses + i));
583 if (i < printmax - 1)
584 logputs (LOG_VERBOSE, ", ");
586 if (printmax != al->count)
587 logputs (LOG_VERBOSE, ", ...");
588 logputs (LOG_VERBOSE, "\n");
591 /* Cache the lookup information. */
593 cache_host_lookup (host, al);
598 /* Resolve HOST to get an address for use with bind(2). Do *not* use
599 this for sockets to be used with connect(2).
601 This is a function separate from lookup_host because the results it
602 returns are different -- it uses the AI_PASSIVE flag to
603 getaddrinfo. Because of this distinction, it doesn't store the
604 results in the cache. It prints nothing and implements no timeouts
605 because it should normally only be used with local addresses
606 (typically "localhost" or numeric addresses of different local
609 Without IPv6, this function just calls lookup_host. */
611 struct address_list *
612 lookup_host_passive (const char *host)
615 struct address_list *al = NULL;
617 struct addrinfo hints, *res;
620 hints.ai_socktype = SOCK_STREAM;
621 hints.ai_family = AF_UNSPEC; /* #### should look at opt.ipv4_only
623 hints.ai_flags = AI_PASSIVE;
625 err = getaddrinfo (host, NULL, &hints, &res);
626 if (err != 0 || res == NULL)
628 al = address_list_from_addrinfo (res);
632 return lookup_host (host, 1);
636 /* Determine whether a URL is acceptable to be followed, according to
637 a list of domains to accept. */
639 accept_domain (struct url *u)
641 assert (u->host != NULL);
644 if (!sufmatch ((const char **)opt.domains, u->host))
647 if (opt.exclude_domains)
649 if (sufmatch ((const char **)opt.exclude_domains, u->host))
655 /* Check whether WHAT is matched in LIST, each element of LIST being a
656 pattern to match WHAT against, using backward matching (see
657 match_backwards() in utils.c).
659 If an element of LIST matched, 1 is returned, 0 otherwise. */
661 sufmatch (const char **list, const char *what)
666 for (i = 0; list[i]; i++)
668 for (j = strlen (list[i]), k = lw; j >= 0 && k >= 0; j--, k--)
669 if (TOLOWER (list[i][j]) != TOLOWER (what[k]))
671 /* The domain must be first to reach to beginning. */
679 host_cleanup_mapper (void *key, void *value, void *arg_ignored)
681 struct address_list *al;
683 xfree (key); /* host */
685 al = (struct address_list *)value;
686 assert (al->refcount == 1);
687 address_list_delete (al);
695 if (host_name_addresses_map)
697 hash_table_map (host_name_addresses_map, host_cleanup_mapper, NULL);
698 hash_table_destroy (host_name_addresses_map);
699 host_name_addresses_map = NULL;