-/* Dealing with host names.
- Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
+/* Host name resolution and matching.
+ Copyright (C) 1996-2006 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.
+the Free Software Foundation; either version 3 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
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. */
+along with Wget. If not, see <http://www.gnu.org/licenses/>.
+
+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 <config.h>
#include <stdio.h>
#include <stdlib.h>
-#ifdef HAVE_STRING_H
-# include <string.h>
-#else
-# include <strings.h>
-#endif
+#include <string.h>
#include <assert.h>
-#include <sys/types.h>
-#ifdef WINDOWS
-# include <winsock.h>
-#else
+#ifndef WINDOWS
# include <sys/socket.h>
# include <netinet/in.h>
-#ifndef __BEOS__
-# include <arpa/inet.h>
-#endif
+# ifndef __BEOS__
+# endif
# include <netdb.h>
+# define SET_H_ERRNO(err) ((void)(h_errno = (err)))
+#else /* WINDOWS */
+# define SET_H_ERRNO(err) WSASetLastError (err)
#endif /* WINDOWS */
-#ifndef NO_ADDRESS
-#define NO_ADDRESS NO_DATA
-#endif
-
-#ifdef HAVE_SYS_UTSNAME_H
-# include <sys/utsname.h>
-#endif
#include <errno.h>
#include "wget.h"
#include "url.h"
#include "hash.h"
-#ifndef errno
-extern int errno;
+#ifndef NO_ADDRESS
+# define NO_ADDRESS NO_DATA
#endif
-#define IP4_ADDRESS_LENGTH 4
-
-/* Mapping between known hosts and to lists of their addresses. */
-
-struct hash_table *host_name_addresses_map;
-\f
-/* Lists of addresses. This should eventually be extended to handle
- IPv6. */
+/* Lists of IP addresses that result from running DNS queries. See
+ lookup_host for details. */
struct address_list {
int count; /* number of adrresses */
- unsigned char *buffer; /* buffer which holds all of them. */
+ ip_address *addresses; /* pointer to the string of addresses */
+
+ int faulty; /* number of addresses known not to work. */
+ bool connected; /* whether we were able to connect to
+ one of the addresses in the list,
+ at least once. */
- int refcount; /* so we know whether to free it or
- not. */
+ int refcount; /* reference count; when it drops to
+ 0, the entry is freed. */
};
-#define ADDR_LOCATION(al, index) ((al)->buffer + index * IP4_ADDRESS_LENGTH)
+/* Get the bounds of the address list. */
+
+void
+address_list_get_bounds (const struct address_list *al, int *start, int *end)
+{
+ *start = al->faulty;
+ *end = al->count;
+}
+
+/* Return a pointer to the address at position POS. */
+
+const ip_address *
+address_list_address_at (const struct address_list *al, int pos)
+{
+ assert (pos >= al->faulty && pos < al->count);
+ return al->addresses + pos;
+}
+
+/* Return true if AL contains IP, false otherwise. */
+
+bool
+address_list_contains (const struct address_list *al, const ip_address *ip)
+{
+ int i;
+ switch (ip->family)
+ {
+ case AF_INET:
+ for (i = 0; i < al->count; i++)
+ {
+ ip_address *cur = al->addresses + i;
+ if (cur->family == AF_INET
+ && (cur->data.d4.s_addr == ip->data.d4.s_addr))
+ return true;
+ }
+ return false;
+#ifdef ENABLE_IPV6
+ case AF_INET6:
+ for (i = 0; i < al->count; i++)
+ {
+ ip_address *cur = al->addresses + i;
+ if (cur->family == AF_INET6
+#ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
+ && cur->ipv6_scope == ip->ipv6_scope
+#endif
+ && IN6_ARE_ADDR_EQUAL (&cur->data.d6, &ip->data.d6))
+ return true;
+ }
+ return false;
+#endif /* ENABLE_IPV6 */
+ default:
+ abort ();
+ }
+}
-/* Return the number of addresses in the list. */
+/* Mark the INDEXth element of AL as faulty, so that the next time
+ this address list is used, the faulty element will be skipped. */
-int
-address_list_count (struct address_list *al)
+void
+address_list_set_faulty (struct address_list *al, int index)
{
- return al->count;
+ /* 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;
}
-/* Copy address number INDEX to IP_STORE. */
+/* Set the "connected" flag to true. This flag used by connect.c to
+ see if the host perhaps needs to be resolved again. */
void
-address_list_copy_one (struct address_list *al, int index,
- unsigned char *ip_store)
+address_list_set_connected (struct address_list *al)
{
- memcpy (ip_store, ADDR_LOCATION (al, index), IP4_ADDRESS_LENGTH);
+ al->connected = true;
}
-/* Check whether two address lists have all their IPs in common. */
+/* Return the value of the "connected" flag. */
-int
-address_list_match_all (struct address_list *al1, struct address_list *al2)
+bool
+address_list_connected_p (const struct address_list *al)
{
- if (al1 == al2)
- return 1;
- if (al1->count != al2->count)
- return 0;
- return 0 == memcmp (al1->buffer, al2->buffer,
- al1->count * IP4_ADDRESS_LENGTH);
+ return al->connected;
}
-/* Create an address_list out of a NULL-terminated list of addresses,
- as returned by gethostbyname. */
+#ifdef ENABLE_IPV6
+
+/* Create an address_list from the addresses in the given struct
+ addrinfo. */
static struct address_list *
-address_list_new (char **h_addr_list)
+address_list_from_addrinfo (const struct addrinfo *ai)
+{
+ struct address_list *al;
+ const struct addrinfo *ptr;
+ int cnt;
+ ip_address *ip;
+
+ cnt = 0;
+ for (ptr = ai; ptr != NULL ; ptr = ptr->ai_next)
+ if (ptr->ai_family == AF_INET || ptr->ai_family == AF_INET6)
+ ++cnt;
+ if (cnt == 0)
+ return NULL;
+
+ al = xnew0 (struct address_list);
+ al->addresses = xnew_array (ip_address, cnt);
+ al->count = cnt;
+ al->refcount = 1;
+
+ ip = al->addresses;
+ for (ptr = ai; ptr != NULL; ptr = ptr->ai_next)
+ if (ptr->ai_family == AF_INET6)
+ {
+ const struct sockaddr_in6 *sin6 =
+ (const struct sockaddr_in6 *)ptr->ai_addr;
+ ip->family = AF_INET6;
+ ip->data.d6 = sin6->sin6_addr;
+#ifdef HAVE_SOCKADDR_IN6_SCOPE_ID
+ ip->ipv6_scope = sin6->sin6_scope_id;
+#endif
+ ++ip;
+ }
+ else if (ptr->ai_family == AF_INET)
+ {
+ const struct sockaddr_in *sin =
+ (const struct sockaddr_in *)ptr->ai_addr;
+ ip->family = AF_INET;
+ ip->data.d4 = sin->sin_addr;
+ ++ip;
+ }
+ assert (ip - al->addresses == cnt);
+ return al;
+}
+
+#define IS_IPV4(addr) (((const ip_address *) addr)->family == AF_INET)
+
+/* Compare two IP addresses by family, giving preference to the IPv4
+ address (sorting it first). In other words, return -1 if ADDR1 is
+ IPv4 and ADDR2 is IPv6, +1 if ADDR1 is IPv6 and ADDR2 is IPv4, and
+ 0 otherwise.
+
+ This is intended to be used as the comparator arg to a qsort-like
+ sorting function, which is why it accepts generic pointers. */
+
+static int
+cmp_prefer_ipv4 (const void *addr1, const void *addr2)
{
- int count = 0, i;
+ return !IS_IPV4 (addr1) - !IS_IPV4 (addr2);
+}
+
+#define IS_IPV6(addr) (((const ip_address *) addr)->family == AF_INET6)
- struct address_list *al = xmalloc (sizeof (struct address_list));
+/* Like the above, but give preference to the IPv6 address. */
- while (h_addr_list[count])
+static int
+cmp_prefer_ipv6 (const void *addr1, const void *addr2)
+{
+ return !IS_IPV6 (addr1) - !IS_IPV6 (addr2);
+}
+
+#else /* not ENABLE_IPV6 */
+
+/* Create an address_list from a NULL-terminated vector of IPv4
+ addresses. This kind of vector is returned by gethostbyname. */
+
+static struct address_list *
+address_list_from_ipv4_addresses (char **vec)
+{
+ int count, i;
+ struct address_list *al = xnew0 (struct address_list);
+
+ count = 0;
+ while (vec[count])
++count;
assert (count > 0);
- al->count = count;
- al->buffer = xmalloc (count * IP4_ADDRESS_LENGTH);
- al->refcount = 1;
+
+ al->addresses = xnew_array (ip_address, count);
+ al->count = count;
+ al->refcount = 1;
for (i = 0; i < count; i++)
- memcpy (ADDR_LOCATION (al, i), h_addr_list[i], IP4_ADDRESS_LENGTH);
+ {
+ ip_address *ip = &al->addresses[i];
+ ip->family = AF_INET;
+ memcpy (IP_INADDR_DATA (ip), vec[i], 4);
+ }
return al;
}
+#endif /* not ENABLE_IPV6 */
+
static void
address_list_delete (struct address_list *al)
{
- xfree (al->buffer);
+ xfree (al->addresses);
xfree (al);
}
+/* Mark the address list as being no longer in use. This will reduce
+ its reference count which will cause the list to be freed when the
+ count reaches 0. */
+
void
address_list_release (struct address_list *al)
{
--al->refcount;
- DEBUGP (("Releasing %p (new refcount %d).\n", al, al->refcount));
+ DEBUGP (("Releasing 0x%0*lx (new refcount %d).\n", PTR_FORMAT (al),
+ al->refcount));
if (al->refcount <= 0)
{
- DEBUGP (("Deleting unused %p.\n", al));
+ DEBUGP (("Deleting unused 0x%0*lx.\n", PTR_FORMAT (al)));
address_list_delete (al);
}
}
\f
-/* The same as inet_ntoa, but without the need for a cast, or for
- #including the netinet stuff. */
+/* Versions of gethostbyname and getaddrinfo that support timeout. */
+
+#ifndef ENABLE_IPV6
-char *
-pretty_print_address (const unsigned char *addr)
+struct ghbnwt_context {
+ const char *host_name;
+ struct hostent *hptr;
+};
+
+static void
+gethostbyname_with_timeout_callback (void *arg)
{
- return inet_ntoa (*(struct in_addr *)addr);
+ struct ghbnwt_context *ctx = (struct ghbnwt_context *)arg;
+ ctx->hptr = gethostbyname (ctx->host_name);
}
-/* 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. */
+/* 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, double 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;
+}
+
+/* Print error messages for host errors. */
+static char *
+host_errstr (int error)
+{
+ /* Can't use switch since some of these constants can be equal,
+ which makes the compiler complain about duplicate case
+ values. */
+ if (error == HOST_NOT_FOUND
+ || error == NO_RECOVERY
+ || error == NO_DATA
+ || error == NO_ADDRESS)
+ return _("Unknown host");
+ else if (error == TRY_AGAIN)
+ /* Message modeled after what gai_strerror returns in similar
+ circumstances. */
+ return _("Temporary failure in name resolution");
+ else
+ return _("Unknown error");
+}
+
+#else /* ENABLE_IPV6 */
+
+struct gaiwt_context {
+ const char *node;
+ const char *service;
+ const struct addrinfo *hints;
+ struct addrinfo **res;
+ int exit_code;
+};
static void
-cache_host_lookup (const char *host, struct address_list *al)
+getaddrinfo_with_timeout_callback (void *arg)
{
- if (!host_name_addresses_map)
- host_name_addresses_map = make_nocase_string_hash_table (0);
+ struct gaiwt_context *ctx = (struct gaiwt_context *)arg;
+ ctx->exit_code = getaddrinfo (ctx->node, ctx->service, ctx->hints, ctx->res);
+}
- ++al->refcount;
- hash_table_put (host_name_addresses_map, xstrdup_lower (host), al);
+/* 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,
+ double timeout)
+{
+ struct gaiwt_context ctx;
+ ctx.node = node;
+ ctx.service = service;
+ ctx.hints = hints;
+ ctx.res = res;
-#ifdef DEBUG
- if (opt.debug)
+ if (run_with_timeout (timeout, getaddrinfo_with_timeout_callback, &ctx))
{
- int i;
- debug_logprintf ("Caching %s =>", host);
- for (i = 0; i < al->count; i++)
- debug_logprintf (" %s",
- pretty_print_address (ADDR_LOCATION (al, i)));
- debug_logprintf ("\n");
+ errno = ETIMEDOUT;
+ return EAI_SYSTEM;
}
+ return ctx.exit_code;
+}
+
+#endif /* ENABLE_IPV6 */
+\f
+/* Return a textual representation of ADDR, i.e. the dotted quad for
+ IPv4 addresses, and the colon-separated list of hex words (with all
+ zeros omitted, etc.) for IPv6 addresses. */
+
+const char *
+print_address (const ip_address *addr)
+{
+#ifdef ENABLE_IPV6
+ static char buf[64];
+ if (!inet_ntop (addr->family, IP_INADDR_DATA (addr), buf, sizeof buf))
+ snprintf (buf, sizeof buf, "<error: %s>", strerror (errno));
+ return buf;
+#else
+ return inet_ntoa (addr->data.d4);
#endif
}
-struct address_list *
-lookup_host (const char *host, int silent)
+/* The following two functions were adapted from glibc's
+ implementation of inet_pton, written by Paul Vixie. */
+
+static bool
+is_valid_ipv4_address (const char *str, const char *end)
{
- struct address_list *al = NULL;
- unsigned long addr;
- struct hostent *hptr;
+ bool saw_digit = false;
+ int octets = 0;
+ int val = 0;
- /* If the address is of the form d.d.d.d, no further lookup is
- needed. */
- addr = (unsigned long)inet_addr (host);
- if ((int)addr != -1)
+ while (str < end)
{
- unsigned char tmpstore[IP4_ADDRESS_LENGTH];
- char *lst[] = { tmpstore, NULL };
-
- /* 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;
-#ifdef WORDS_BIGENDIAN
- offset = sizeof (unsigned long) - IP4_ADDRESS_LENGTH;
-#else
- offset = 0;
-#endif
- memcpy (tmpstore, (char *)&addr + offset, IP4_ADDRESS_LENGTH);
- return address_list_new (lst);
+ int ch = *str++;
+
+ if (ch >= '0' && ch <= '9')
+ {
+ val = val * 10 + (ch - '0');
+
+ if (val > 255)
+ return false;
+ if (!saw_digit)
+ {
+ if (++octets > 4)
+ return false;
+ saw_digit = true;
+ }
+ }
+ else if (ch == '.' && saw_digit)
+ {
+ if (octets == 4)
+ return false;
+ val = 0;
+ saw_digit = false;
+ }
+ else
+ return false;
}
+ if (octets < 4)
+ return false;
+
+ return true;
+}
- /* By now we know that the host name we got is not of the form
- d.d.d.d. Try to find it in our cache of host names. */
- if (host_name_addresses_map)
- al = hash_table_get (host_name_addresses_map, host);
+bool
+is_valid_ipv6_address (const char *str, const char *end)
+{
+ /* Use lower-case for these to avoid clash with system headers. */
+ enum {
+ ns_inaddrsz = 4,
+ ns_in6addrsz = 16,
+ ns_int16sz = 2
+ };
+
+ const char *curtok;
+ int tp;
+ const char *colonp;
+ bool saw_xdigit;
+ unsigned int val;
+
+ tp = 0;
+ colonp = NULL;
+
+ if (str == end)
+ return false;
+
+ /* Leading :: requires some special handling. */
+ if (*str == ':')
+ {
+ ++str;
+ if (str == end || *str != ':')
+ return false;
+ }
+
+ curtok = str;
+ saw_xdigit = false;
+ val = 0;
+
+ while (str < end)
+ {
+ int ch = *str++;
+
+ /* if ch is a number, add it to val. */
+ if (ISXDIGIT (ch))
+ {
+ val <<= 4;
+ val |= XDIGIT_TO_NUM (ch);
+ if (val > 0xffff)
+ return false;
+ saw_xdigit = true;
+ continue;
+ }
+
+ /* if ch is a colon ... */
+ if (ch == ':')
+ {
+ curtok = str;
+ if (!saw_xdigit)
+ {
+ if (colonp != NULL)
+ return false;
+ colonp = str + tp;
+ continue;
+ }
+ else if (str == end)
+ return false;
+ if (tp > ns_in6addrsz - ns_int16sz)
+ return false;
+ tp += ns_int16sz;
+ saw_xdigit = false;
+ val = 0;
+ continue;
+ }
+
+ /* if ch is a dot ... */
+ if (ch == '.' && (tp <= ns_in6addrsz - ns_inaddrsz)
+ && is_valid_ipv4_address (curtok, end) == 1)
+ {
+ tp += ns_inaddrsz;
+ saw_xdigit = false;
+ break;
+ }
+
+ return false;
+ }
+
+ if (saw_xdigit)
+ {
+ if (tp > ns_in6addrsz - ns_int16sz)
+ return false;
+ tp += ns_int16sz;
+ }
+
+ if (colonp != NULL)
+ {
+ if (tp == ns_in6addrsz)
+ return false;
+ tp = ns_in6addrsz;
+ }
+
+ if (tp != ns_in6addrsz)
+ return false;
+
+ return true;
+}
+\f
+/* Simple host cache, used by lookup_host to speed up resolving. The
+ cache doesn't handle TTL because Wget is a fairly short-lived
+ application. Refreshing is attempted when connect fails, though --
+ see connect_to_host. */
+/* Mapping between known hosts and to lists of their addresses. */
+static struct hash_table *host_name_addresses_map;
+
+
+/* Return the host's resolved addresses from the cache, if
+ available. */
+
+static struct address_list *
+cache_query (const char *host)
+{
+ struct address_list *al;
+ if (!host_name_addresses_map)
+ return NULL;
+ 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;
}
+ return NULL;
+}
+
+/* Cache the DNS lookup of HOST. Subsequent invocations of
+ lookup_host will return the cached value. */
+
+static void
+cache_store (const char *host, struct address_list *al)
+{
+ if (!host_name_addresses_map)
+ host_name_addresses_map = make_nocase_string_hash_table (0);
- if (!silent)
- logprintf (LOG_VERBOSE, _("Resolving %s... "), host);
+ ++al->refcount;
+ hash_table_put (host_name_addresses_map, xstrdup_lower (host), al);
- /* Look up the host using gethostbyname(). Note that we use
- gethostbyname() rather than ngethostbyname(), because we already
- know that the address is not numerical. */
- hptr = gethostbyname (host);
- if (!hptr)
+ IF_DEBUG
{
- if (!silent)
- logprintf (LOG_VERBOSE, _("failed: %s.\n"), herrmsg (h_errno));
- return NULL;
+ int i;
+ debug_logprintf ("Caching %s =>", host);
+ for (i = 0; i < al->count; i++)
+ debug_logprintf (" %s", print_address (al->addresses + i));
+ debug_logprintf ("\n");
+ }
+}
+
+/* Remove HOST from the DNS cache. Does nothing is HOST is not in
+ the cache. */
+
+static void
+cache_remove (const char *host)
+{
+ struct address_list *al;
+ if (!host_name_addresses_map)
+ return;
+ al = hash_table_get (host_name_addresses_map, host);
+ if (al)
+ {
+ address_list_release (al);
+ hash_table_remove (host_name_addresses_map, host);
}
+}
+\f
+/* Look up HOST in DNS and return a list of IP addresses.
+
+ This function caches its result so that, if the same host is passed
+ the second time, the addresses are returned without DNS lookup.
+ (Use LH_REFRESH to force lookup, or set opt.dns_cache to 0 to
+ globally disable caching.)
+
+ The order of the returned addresses is affected by the setting of
+ opt.prefer_family: if it is set to prefer_ipv4, IPv4 addresses are
+ placed at the beginning; if it is prefer_ipv6, IPv6 ones are placed
+ at the beginning; otherwise, the order is left intact. The
+ relative order of addresses with the same family is left
+ undisturbed in either case.
+
+ FLAGS can be a combination of:
+ LH_SILENT - don't print the "resolving ... done" messages.
+ LH_BIND - resolve addresses for use with bind, which under
+ IPv6 means to use AI_PASSIVE flag to getaddrinfo.
+ Passive lookups are not cached under IPv6.
+ LH_REFRESH - if HOST is cached, remove the entry from the cache
+ and resolve it anew. */
+
+struct address_list *
+lookup_host (const char *host, int flags)
+{
+ struct address_list *al;
+ bool silent = !!(flags & LH_SILENT);
+ bool use_cache;
+ bool numeric_address = false;
+ double timeout = opt.dns_timeout;
+
+#ifndef ENABLE_IPV6
+ /* If we're not using getaddrinfo, first check if HOST specifies a
+ numeric IPv4 address. Some implementations of gethostbyname
+ (e.g. the Ultrix one and possibly Winsock) don't accept
+ dotted-decimal IPv4 addresses. */
+ {
+ uint32_t addr_ipv4 = (uint32_t)inet_addr (host);
+ if (addr_ipv4 != (uint32_t) -1)
+ {
+ /* No need to cache host->addr relation, just return the
+ address. */
+ char *vec[2];
+ vec[0] = (char *)&addr_ipv4;
+ vec[1] = NULL;
+ return address_list_from_ipv4_addresses (vec);
+ }
+ }
+#else /* ENABLE_IPV6 */
+ /* If we're using getaddrinfo, at least check whether the address is
+ already numeric, in which case there is no need to print the
+ "Resolving..." output. (This comes at no additional cost since
+ the is_valid_ipv*_address are already required for
+ url_parse.) */
+ {
+ const char *end = host + strlen (host);
+ if (is_valid_ipv4_address (host, end) || is_valid_ipv6_address (host, end))
+ numeric_address = true;
+ }
+#endif
- if (!silent)
- logprintf (LOG_VERBOSE, _("done.\n"));
+ /* Cache is normally on, but can be turned off with --no-dns-cache.
+ Don't cache passive lookups under IPv6. */
+ use_cache = opt.dns_cache;
+#ifdef ENABLE_IPV6
+ if ((flags & LH_BIND) || numeric_address)
+ use_cache = false;
+#endif
- al = address_list_new (hptr->h_addr_list);
+ /* Try to find the host in the cache so we don't need to talk to the
+ resolver. If LH_REFRESH is requested, remove HOST from the cache
+ instead. */
+ if (use_cache)
+ {
+ if (!(flags & LH_REFRESH))
+ {
+ al = cache_query (host);
+ if (al)
+ return al;
+ }
+ else
+ cache_remove (host);
+ }
+
+ /* No luck with the cache; resolve HOST. */
+
+ if (!silent && !numeric_address)
+ logprintf (LOG_VERBOSE, _("Resolving %s... "), escnonprint (host));
+
+#ifdef ENABLE_IPV6
+ {
+ int err;
+ struct addrinfo hints, *res;
+
+ xzero (hints);
+ hints.ai_socktype = SOCK_STREAM;
+ if (opt.ipv4_only)
+ hints.ai_family = AF_INET;
+ else if (opt.ipv6_only)
+ hints.ai_family = AF_INET6;
+ else
+ /* We tried using AI_ADDRCONFIG, but removed it because: it
+ misinterprets IPv6 loopbacks, it is broken on AIX 5.1, and
+ it's unneeded since we sort the addresses anyway. */
+ hints.ai_family = AF_UNSPEC;
+
+ if (flags & LH_BIND)
+ hints.ai_flags |= AI_PASSIVE;
+
+#ifdef AI_NUMERICHOST
+ if (numeric_address)
+ {
+ /* Where available, the AI_NUMERICHOST hint can prevent costly
+ access to DNS servers. */
+ hints.ai_flags |= AI_NUMERICHOST;
+ timeout = 0; /* no timeout needed when "resolving"
+ numeric hosts -- avoid setting up
+ signal handlers and such. */
+ }
+#endif
+
+ err = getaddrinfo_with_timeout (host, NULL, &hints, &res, timeout);
+ if (err != 0 || res == NULL)
+ {
+ if (!silent)
+ logprintf (LOG_VERBOSE, _("failed: %s.\n"),
+ err != EAI_SYSTEM ? gai_strerror (err) : strerror (errno));
+ return NULL;
+ }
+ al = address_list_from_addrinfo (res);
+ freeaddrinfo (res);
+ if (!al)
+ {
+ logprintf (LOG_VERBOSE,
+ _("failed: No IPv4/IPv6 addresses for host.\n"));
+ return NULL;
+ }
+
+ /* Reorder addresses so that IPv4 ones (or IPv6 ones, as per
+ --prefer-family) come first. Sorting is stable so the order of
+ the addresses with the same family is undisturbed. */
+ if (al->count > 1 && opt.prefer_family != prefer_none)
+ stable_sort (al->addresses, al->count, sizeof (ip_address),
+ opt.prefer_family == prefer_ipv4
+ ? cmp_prefer_ipv4 : cmp_prefer_ipv6);
+ }
+#else /* not ENABLE_IPV6 */
+ {
+ struct hostent *hptr = gethostbyname_with_timeout (host, timeout);
+ if (!hptr)
+ {
+ if (!silent)
+ {
+ if (errno != ETIMEDOUT)
+ logprintf (LOG_VERBOSE, _("failed: %s.\n"),
+ host_errstr (h_errno));
+ else
+ logputs (LOG_VERBOSE, _("failed: timed out.\n"));
+ }
+ return NULL;
+ }
+ /* Do older systems have h_addr_list? */
+ al = address_list_from_ipv4_addresses (hptr->h_addr_list);
+ }
+#endif /* not ENABLE_IPV6 */
+
+ /* Print the addresses determined by DNS lookup, but no more than
+ three. */
+ if (!silent && !numeric_address)
+ {
+ int i;
+ int printmax = al->count <= 3 ? al->count : 3;
+ for (i = 0; i < printmax; i++)
+ {
+ logputs (LOG_VERBOSE, print_address (al->addresses + i));
+ if (i < printmax - 1)
+ logputs (LOG_VERBOSE, ", ");
+ }
+ if (printmax != al->count)
+ logputs (LOG_VERBOSE, ", ...");
+ logputs (LOG_VERBOSE, "\n");
+ }
/* Cache the lookup information. */
- cache_host_lookup (host, al);
+ if (use_cache)
+ cache_store (host, al);
return al;
}
\f
/* Determine whether a URL is acceptable to be followed, according to
a list of domains to accept. */
-int
+bool
accept_domain (struct url *u)
{
assert (u->host != NULL);
if (opt.domains)
{
if (!sufmatch ((const char **)opt.domains, u->host))
- return 0;
+ return false;
}
if (opt.exclude_domains)
{
if (sufmatch ((const char **)opt.exclude_domains, u->host))
- return 0;
+ return false;
}
- return 1;
+ return true;
}
/* Check whether WHAT is matched in LIST, each element of LIST being a
match_backwards() in utils.c).
If an element of LIST matched, 1 is returned, 0 otherwise. */
-int
+bool
sufmatch (const char **list, const char *what)
{
int i, j, k, lw;
break;
/* The domain must be first to reach to beginning. */
if (j == -1)
- return 1;
+ return true;
}
- 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;
+ return false;
}
void
{
if (host_name_addresses_map)
{
- hash_table_map (host_name_addresses_map, host_cleanup_mapper, NULL);
+ hash_table_iterator iter;
+ for (hash_table_iterate (host_name_addresses_map, &iter);
+ hash_table_iter_next (&iter);
+ )
+ {
+ char *host = iter.key;
+ struct address_list *al = iter.value;
+ xfree (host);
+ assert (al->refcount == 1);
+ address_list_delete (al);
+ }
hash_table_destroy (host_name_addresses_map);
host_name_addresses_map = NULL;
}
projects / wget / blobdiff