/* Host name resolution and matching. Copyright (C) 1995, 1996, 1997, 2000, 2001 Free Software Foundation, Inc. This file is part of GNU Wget. GNU Wget is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. GNU Wget is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Wget; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. In addition, as a special exception, the Free Software Foundation gives permission to link the code of its release of Wget with the OpenSSL project's "OpenSSL" library (or with modified versions of it that use the same license as the "OpenSSL" library), and distribute the linked executables. You must obey the GNU General Public License in all respects for all of the code used other than "OpenSSL". If you modify this file, you may extend this exception to your version of the file, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ #include #ifndef WINDOWS #include #endif #include #include #ifdef HAVE_STRING_H # include #else # include #endif #include #include #ifdef WINDOWS # include # define SET_H_ERRNO(err) WSASetLastError(err) #else # include # include # ifndef __BEOS__ # include # endif # include # define SET_H_ERRNO(err) ((void)(h_errno = (err))) #endif /* WINDOWS */ #ifndef NO_ADDRESS #define NO_ADDRESS NO_DATA #endif #ifdef HAVE_SYS_UTSNAME_H # include #endif #include #include "wget.h" #include "utils.h" #include "host.h" #include "url.h" #include "hash.h" #ifndef errno extern int errno; #endif #ifndef h_errno # ifndef __CYGWIN__ extern int h_errno; # endif #endif #ifdef ENABLE_IPV6 int ip_default_family = AF_INET6; #else int ip_default_family = AF_INET; #endif /* Mapping between known hosts and to lists of their addresses. */ static struct hash_table *host_name_addresses_map; /* Lists of addresses. This should eventually be extended to handle IPv6. */ struct address_list { int count; /* number of adrresses */ ip_address *addresses; /* pointer to the string of addresses */ int faulty; /* number of addresses known not to work. */ int refcount; /* so we know whether to free it or not. */ }; /* Get the bounds of the address list. */ void address_list_get_bounds (struct address_list *al, int *start, int *end) { *start = al->faulty; *end = al->count; } /* Copy address number INDEX to IP_STORE. */ void address_list_copy_one (struct address_list *al, int index, ip_address *ip_store) { assert (index >= al->faulty && index < al->count); memcpy (ip_store, al->addresses + index, sizeof (ip_address)); } /* Check whether two address lists have all their IPs in common. */ int address_list_match_all (struct address_list *al1, struct address_list *al2) { if (al1 == al2) return 1; if (al1->count != al2->count) return 0; return 0 == memcmp (al1->addresses, al2->addresses, al1->count * sizeof (ip_address)); } /* Mark the INDEXth element of AL as faulty, so that the next time this address list is used, the faulty element will be skipped. */ void address_list_set_faulty (struct address_list *al, int index) { /* We assume that the address list is traversed in order, so that a "faulty" attempt is always preceded with all-faulty addresses, and this is how Wget uses it. */ assert (index == al->faulty); ++al->faulty; if (al->faulty >= al->count) /* All addresses have been proven faulty. Since there's not much sense in returning the user an empty address list the next time, we'll rather make them all clean, so that they can be retried anew. */ al->faulty = 0; } #ifdef HAVE_GETADDRINFO /** * address_list_from_addrinfo * * This function transform an addrinfo links list in and address_list. * * Input: * addrinfo* Linkt list of addrinfo * * Output: * address_list* New allocated address_list */ static struct address_list * address_list_from_addrinfo (struct addrinfo *ai) { struct address_list *al; struct addrinfo *ai_head = ai; int cnt = 0; int i; for (ai = ai_head; ai; ai = ai->ai_next) if (ai->ai_family == AF_INET || ai->ai_family == AF_INET6) ++cnt; if (cnt == 0) return NULL; al = xmalloc (sizeof (struct address_list)); al->addresses = xmalloc (cnt * sizeof (ip_address)); al->count = cnt; al->faulty = 0; al->refcount = 1; for (i = 0, ai = ai_head; ai; ai = ai->ai_next) if (ai->ai_family == AF_INET6) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai->ai_addr; memcpy (al->addresses + i, &sin6->sin6_addr, 16); ++i; } else if (ai->ai_family == AF_INET) { struct sockaddr_in *sin = (struct sockaddr_in *)ai->ai_addr; map_ipv4_to_ip ((ip4_address *)&sin->sin_addr, al->addresses + i); ++i; } assert (i == cnt); return al; } #else /* Create an address_list out of a NULL-terminated list of addresses, as returned by gethostbyname. */ static struct address_list * address_list_new (char **h_addr_list) { int count = 0, i; struct address_list *al = xmalloc (sizeof (struct address_list)); while (h_addr_list[count]) ++count; assert (count > 0); al->count = count; al->faulty = 0; al->addresses = xmalloc (count * sizeof (ip_address)); al->refcount = 1; for (i = 0; i < count; i++) map_ipv4_to_ip ((ip4_address *)h_addr_list[i], al->addresses + i); return al; } #endif /* Like address_list_new, but initialized with only one address. */ static struct address_list * address_list_new_one (ip_address *addr) { struct address_list *al = xmalloc (sizeof (struct address_list)); al->count = 1; al->faulty = 0; al->addresses = xmalloc (sizeof (ip_address)); al->refcount = 1; memcpy (al->addresses, addr, sizeof (ip_address)); return al; } static void address_list_delete (struct address_list *al) { xfree (al->addresses); xfree (al); } void address_list_release (struct address_list *al) { --al->refcount; DEBUGP (("Releasing %p (new refcount %d).\n", al, al->refcount)); if (al->refcount <= 0) { DEBUGP (("Deleting unused %p.\n", al)); address_list_delete (al); } } /** * wget_sockaddr_set_address * * This function takes an wget_sockaddr and fill in the protocol type, * the port number and the address, there NULL in address means wildcard. * Unsuported adress family will abort the whole programm. * * Input: * wget_sockaddr* The space to be filled * int The wished protocol * unsigned short The port * const ip_address The Binary IP adress * * Return: * - Only modify 1. param */ void wget_sockaddr_set_address (wget_sockaddr *sa, int ip_family, unsigned short port, ip_address *addr) { if (ip_family == AF_INET) { sa->sin.sin_family = ip_family; sa->sin.sin_port = htons (port); if (addr == NULL) memset (&sa->sin.sin_addr, 0, sizeof(ip4_address)); else { ip4_address addr4; if (!map_ip_to_ipv4 (addr, &addr4)) /* should the callers have prevented this? */ abort (); memcpy (&sa->sin.sin_addr, &addr4, sizeof(ip4_address)); } return; } #ifdef ENABLE_IPV6 if (ip_family == AF_INET6) { sa->sin6.sin6_family = ip_family; sa->sin6.sin6_port = htons (port); if (addr == NULL) memset (&sa->sin6.sin6_addr, 0 , 16); else memcpy (&sa->sin6.sin6_addr, addr, 16); return; } #endif abort(); } /** * wget_sockaddr_set_port * * This funtion only fill the port of the socket information. * If the protocol is not supported nothing is done. * Unsuported adress family will abort the whole programm. * * Require: * that the IP-Protocol already is set. * * Input: * wget_sockaddr* The space there port should be entered * unsigned int The port that should be entered in host order * * Return: * - Only modify 1. param */ void wget_sockaddr_set_port (wget_sockaddr *sa, unsigned short port) { if (sa->sa.sa_family == AF_INET) { sa->sin.sin_port = htons (port); return; } #ifdef ENABLE_IPV6 if (sa->sa.sa_family == AF_INET6) { sa->sin6.sin6_port = htons (port); return; } #endif abort(); } /** * wget_sockaddr_get_addr * * This function return the adress from an sockaddr as byte string. * Unsuported adress family will abort the whole programm. * * Require: * that the IP-Protocol already is set. * * Input: * wget_sockaddr* Socket Information * * Output: * unsigned char * IP address as byte string. */ void * wget_sockaddr_get_addr (wget_sockaddr *sa) { if (sa->sa.sa_family == AF_INET) return &sa->sin.sin_addr; #ifdef ENABLE_IPV6 if (sa->sa.sa_family == AF_INET6) return &sa->sin6.sin6_addr; #endif abort(); /* unreached */ return NULL; } /** * wget_sockaddr_get_port * * This function only return the port from the input structure * Unsuported adress family will abort the whole programm. * * Require: * that the IP-Protocol already is set. * * Input: * wget_sockaddr* Information where to get the port * * Output: * unsigned short Port Number in host order. */ unsigned short wget_sockaddr_get_port (const wget_sockaddr *sa) { if (sa->sa.sa_family == AF_INET) return htons (sa->sin.sin_port); #ifdef ENABLE_IPV6 if (sa->sa.sa_family == AF_INET6) return htons (sa->sin6.sin6_port); #endif abort(); /* do not complain about return nothing */ return -1; } /** * sockaddr_len * * This function return the length of the sockaddr corresponding to * the acutall prefered protocol for (bind, connect etc...) * Unsuported adress family will abort the whole programm. * * Require: * that the IP-Protocol already is set. * * Input: * - Public IP-Family Information * * Output: * int structure length for socket options */ int sockaddr_len () { if (ip_default_family == AF_INET) return sizeof (struct sockaddr_in); #ifdef ENABLE_IPV6 if (ip_default_family == AF_INET6) return sizeof (struct sockaddr_in6); #endif abort(); /* do not complain about return nothing */ return 0; } /** * Map an IPv4 adress to the internal adress format. */ void map_ipv4_to_ip (ip4_address *ipv4, ip_address *ip) { #ifdef ENABLE_IPV6 static unsigned char ipv64[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}; memcpy ((char *)ip + 12, ipv4 , 4); memcpy ((char *)ip + 0, ipv64, 12); #else if ((char *)ip != (char *)ipv4) memcpy (ip, ipv4, 4); #endif } /* Detect whether an IP adress represents an IPv4 address and, if so, copy it to IPV4. 0 is returned on failure. This operation always succeeds when Wget is compiled without IPv6. If IPV4 is NULL, don't copy, just detect. */ int map_ip_to_ipv4 (ip_address *ip, ip4_address *ipv4) { #ifdef ENABLE_IPV6 static unsigned char ipv64[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff}; if (0 != memcmp (ip, ipv64, 12)) return 0; if (ipv4) memcpy (ipv4, (char *)ip + 12, 4); #else if (ipv4) memcpy (ipv4, (char *)ip, 4); #endif return 1; } /* Versions of gethostbyname and getaddrinfo that support timeout. */ #ifndef ENABLE_IPV6 struct ghbnwt_context { const char *host_name; struct hostent *hptr; }; static void gethostbyname_with_timeout_callback (void *arg) { struct ghbnwt_context *ctx = (struct ghbnwt_context *)arg; ctx->hptr = gethostbyname (ctx->host_name); } /* Just like gethostbyname, except it times out after TIMEOUT seconds. In case of timeout, NULL is returned and errno is set to ETIMEDOUT. The function makes sure that when NULL is returned for reasons other than timeout, errno is reset. */ static struct hostent * gethostbyname_with_timeout (const char *host_name, int timeout) { struct ghbnwt_context ctx; ctx.host_name = host_name; if (run_with_timeout (timeout, gethostbyname_with_timeout_callback, &ctx)) { SET_H_ERRNO (HOST_NOT_FOUND); errno = ETIMEDOUT; return NULL; } if (!ctx.hptr) errno = 0; return ctx.hptr; } #else /* ENABLE_IPV6 */ struct gaiwt_context { const char *node; const char *service; const struct addrinfo *hints; struct addrinfo **res; int exit_code; }; static void getaddrinfo_with_timeout_callback (void *arg) { struct gaiwt_context *ctx = (struct gaiwt_context *)arg; ctx->exit_code = getaddrinfo (ctx->node, ctx->service, ctx->hints, ctx->res); } /* Just like getaddrinfo, except it times out after TIMEOUT seconds. In case of timeout, the EAI_SYSTEM error code is returned and errno is set to ETIMEDOUT. */ static int getaddrinfo_with_timeout (const char *node, const char *service, const struct addrinfo *hints, struct addrinfo **res, int timeout) { struct gaiwt_context ctx; ctx.node = node; ctx.service = service; ctx.hints = hints; ctx.res = res; if (run_with_timeout (timeout, getaddrinfo_with_timeout_callback, &ctx)) { errno = ETIMEDOUT; return EAI_SYSTEM; } return ctx.exit_code; } #endif /* ENABLE_IPV6 */ /* Pretty-print ADDR. When compiled without IPv6, this is the same as inet_ntoa. With IPv6, it either prints an IPv6 address or an IPv4 address. */ char * pretty_print_address (ip_address *addr) { #ifdef ENABLE_IPV6 ip4_address addr4; static char buf[128]; if (map_ip_to_ipv4 (addr, &addr4)) return inet_ntoa (*(struct in_addr *)&addr4); if (!inet_ntop (AF_INET6, addr, buf, sizeof (buf))) return ""; return buf; #endif return inet_ntoa (*(struct in_addr *)addr); } /* Add host name HOST with the address ADDR_TEXT to the cache. ADDR_LIST is a NULL-terminated list of addresses, as in struct hostent. */ static void cache_host_lookup (const char *host, struct address_list *al) { if (!host_name_addresses_map) host_name_addresses_map = make_nocase_string_hash_table (0); ++al->refcount; hash_table_put (host_name_addresses_map, xstrdup_lower (host), al); #ifdef DEBUG if (opt.debug) { int i; debug_logprintf ("Caching %s =>", host); for (i = 0; i < al->count; i++) debug_logprintf (" %s", pretty_print_address (al->addresses + i)); debug_logprintf ("\n"); } #endif } struct address_list * lookup_host (const char *host, int silent) { struct address_list *al = NULL; unsigned long addr_ipv4; /* #### use a 32-bit type here. */ ip_address addr; /* First, try to check whether the address is already a numeric address. */ #ifdef ENABLE_IPV6 if (inet_pton (AF_INET6, host, &addr) > 0) return address_list_new_one (&addr); #endif addr_ipv4 = (unsigned long)inet_addr (host); if ((int)addr_ipv4 != -1) { /* ADDR is defined to be in network byte order, which is what this returns, so we can just copy it to STORE_IP. However, on big endian 64-bit architectures the value will be stored in the *last*, not first four bytes. OFFSET makes sure that we copy the correct four bytes. */ int offset = 0; #ifdef WORDS_BIGENDIAN offset = sizeof (unsigned long) - sizeof (ip4_address); #endif map_ipv4_to_ip ((ip4_address *)((char *)&addr_ipv4 + offset), &addr); return address_list_new_one (&addr); } if (host_name_addresses_map) { al = hash_table_get (host_name_addresses_map, host); if (al) { DEBUGP (("Found %s in host_name_addresses_map (%p)\n", host, al)); ++al->refcount; return al; } } if (!silent) logprintf (LOG_VERBOSE, _("Resolving %s... "), host); /* Host name lookup goes on below. */ #ifdef HAVE_GETADDRINFO { struct addrinfo hints, *ai; int err; memset (&hints, 0, sizeof (hints)); if (ip_default_family == AF_INET) hints.ai_family = AF_INET; else hints.ai_family = PF_UNSPEC; hints.ai_socktype = SOCK_STREAM; err = getaddrinfo_with_timeout (host, NULL, &hints, &ai, opt.timeout); if (err != 0 || ai == NULL) { if (!silent) logprintf (LOG_VERBOSE, _("failed: %s.\n"), err != EAI_SYSTEM ? gai_strerror (err) : strerror (errno)); return NULL; } al = address_list_from_addrinfo (ai); freeaddrinfo (ai); } #else { struct hostent *hptr = gethostbyname_with_timeout (host, opt.timeout); if (!hptr) { if (!silent) { if (errno != ETIMEDOUT) logprintf (LOG_VERBOSE, _("failed: %s.\n"), herrmsg (h_errno)); else logputs (LOG_VERBOSE, _("failed: timed out.\n")); } return NULL; } /* Do all systems have h_addr_list, or is it a newer thing? If the latter, use address_list_new_one. */ al = address_list_new (hptr->h_addr_list); } #endif if (!silent) logprintf (LOG_VERBOSE, _("done.\n")); /* Cache the lookup information. */ if (opt.dns_cache) cache_host_lookup (host, al); return al; } /* Determine whether a URL is acceptable to be followed, according to a list of domains to accept. */ int accept_domain (struct url *u) { assert (u->host != NULL); if (opt.domains) { if (!sufmatch ((const char **)opt.domains, u->host)) return 0; } if (opt.exclude_domains) { if (sufmatch ((const char **)opt.exclude_domains, u->host)) return 0; } return 1; } /* Check whether WHAT is matched in LIST, each element of LIST being a pattern to match WHAT against, using backward matching (see match_backwards() in utils.c). If an element of LIST matched, 1 is returned, 0 otherwise. */ int sufmatch (const char **list, const char *what) { int i, j, k, lw; lw = strlen (what); for (i = 0; list[i]; i++) { for (j = strlen (list[i]), k = lw; j >= 0 && k >= 0; j--, k--) if (TOLOWER (list[i][j]) != TOLOWER (what[k])) break; /* The domain must be first to reach to beginning. */ if (j == -1) return 1; } return 0; } /* Print error messages for host errors. */ char * herrmsg (int error) { /* Can't use switch since some constants are equal (at least on my system), and the compiler signals "duplicate case value". */ if (error == HOST_NOT_FOUND || error == NO_RECOVERY || error == NO_DATA || error == NO_ADDRESS || error == TRY_AGAIN) return _("Host not found"); else return _("Unknown error"); } static int host_cleanup_mapper (void *key, void *value, void *arg_ignored) { struct address_list *al; xfree (key); /* host */ al = (struct address_list *)value; assert (al->refcount == 1); address_list_delete (al); return 0; } void host_cleanup (void) { if (host_name_addresses_map) { hash_table_map (host_name_addresses_map, host_cleanup_mapper, NULL); hash_table_destroy (host_name_addresses_map); host_name_addresses_map = NULL; } }