#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>
-# define SET_H_ERRNO(err) WSASetLastError (err)
-#else
+#ifndef WINDOWS
# include <sys/socket.h>
# include <netinet/in.h>
# 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
-
#include <errno.h>
#include "wget.h"
#include "hash.h"
#include "connect.h" /* for socket_has_inet6 */
-#ifndef errno
-extern int errno;
-#endif
-
-#ifndef h_errno
-# ifndef __CYGWIN__
-extern int h_errno;
-# endif
+#ifndef NO_ADDRESS
+# define NO_ADDRESS NO_DATA
#endif
/* Lists of IP addresses that result from running DNS queries. See
return al->addresses + pos;
}
-/* Return 1 if IP is one of the addresses in AL. */
+/* Return non-zero if AL contains IP, zero otherwise. */
int
-address_list_find (const struct address_list *al, const ip_address *ip)
+address_list_contains (const struct address_list *al, const ip_address *ip)
{
int i;
switch (ip->type)
#endif /* ENABLE_IPV6 */
default:
abort ();
- return 1;
}
}
return NULL;
al = xnew0 (struct address_list);
- al->addresses = xnew_array (ip_address, cnt);
- al->count = cnt;
- al->refcount = 1;
+ 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)
return al;
}
+#define IS_IPV4(addr) (((const ip_address *) addr)->type == IPV4_ADDRESS)
+
+/* Compare two IP addresses by type, 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)
+{
+ return !IS_IPV4 (addr1) - !IS_IPV4 (addr2);
+}
+
+#define IS_IPV6(addr) (((const ip_address *) addr)->type == IPV6_ADDRESS)
+
+/* Like the above, but give preference to the IPv6 address. */
+
+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
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);
}
}
#endif
}
abort ();
- return NULL;
+}
+
+/* The following two functions were adapted from glibc. */
+
+static int
+is_valid_ipv4_address (const char *str, const char *end)
+{
+ int saw_digit = 0;
+ int octets = 0;
+ int val = 0;
+
+ while (str < end)
+ {
+ int ch = *str++;
+
+ if (ch >= '0' && ch <= '9')
+ {
+ val = val * 10 + (ch - '0');
+
+ if (val > 255)
+ return 0;
+ if (saw_digit == 0)
+ {
+ if (++octets > 4)
+ return 0;
+ saw_digit = 1;
+ }
+ }
+ else if (ch == '.' && saw_digit == 1)
+ {
+ if (octets == 4)
+ return 0;
+ val = 0;
+ saw_digit = 0;
+ }
+ else
+ return 0;
+ }
+ if (octets < 4)
+ return 0;
+
+ return 1;
+}
+
+int
+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;
+ int saw_xdigit;
+ unsigned int val;
+
+ tp = 0;
+ colonp = NULL;
+
+ if (str == end)
+ return 0;
+
+ /* Leading :: requires some special handling. */
+ if (*str == ':')
+ {
+ ++str;
+ if (str == end || *str != ':')
+ return 0;
+ }
+
+ curtok = str;
+ saw_xdigit = 0;
+ 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 0;
+ saw_xdigit = 1;
+ continue;
+ }
+
+ /* if ch is a colon ... */
+ if (ch == ':')
+ {
+ curtok = str;
+ if (saw_xdigit == 0)
+ {
+ if (colonp != NULL)
+ return 0;
+ colonp = str + tp;
+ continue;
+ }
+ else if (str == end)
+ return 0;
+ if (tp > ns_in6addrsz - ns_int16sz)
+ return 0;
+ tp += ns_int16sz;
+ saw_xdigit = 0;
+ 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 = 0;
+ break;
+ }
+
+ return 0;
+ }
+
+ if (saw_xdigit == 1)
+ {
+ if (tp > ns_in6addrsz - ns_int16sz)
+ return 0;
+ tp += ns_int16sz;
+ }
+
+ if (colonp != NULL)
+ {
+ if (tp == ns_in6addrsz)
+ return 0;
+ tp = ns_in6addrsz;
+ }
+
+ if (tp != ns_in6addrsz)
+ return 0;
+
+ return 1;
}
\f
/* Simple host cache, used by lookup_host to speed up resolving. The
}
}
\f
-/* Look up HOST in DNS and return a list of IP addresses. The
- addresses in the list are in the same order in which
- gethostbyname/getaddrinfo returned them.
+/* 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
struct address_list *
lookup_host (const char *host, int flags)
{
- struct address_list *al = NULL;
+ struct address_list *al;
int silent = flags & LH_SILENT;
int use_cache;
+ int numeric_address = 0;
+ double timeout = opt.dns_timeout;
#ifndef ENABLE_IPV6
/* If we're not using getaddrinfo, first check if HOST specifies a
- numeric IPv4 address. gethostbyname is not required to accept
- dotted-decimal IPv4 addresses, and some implementations (e.g. the
- Ultrix one and possibly Winsock) indeed don't. */
+ 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)
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 = 1;
+ }
#endif
/* 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)
+ if ((flags & LH_BIND) || numeric_address)
use_cache = 0;
#endif
/* No luck with the cache; resolve HOST. */
- if (!silent)
- logprintf (LOG_VERBOSE, _("Resolving %s... "), host);
+ if (!silent && !numeric_address)
+ logprintf (LOG_VERBOSE, _("Resolving %s... "), escnonprint (host));
#ifdef ENABLE_IPV6
{
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;
-#ifdef HAVE_GETADDRINFO_AI_ADDRCONFIG
- hints.ai_flags |= AI_ADDRCONFIG;
-#else
- /* On systems without AI_ADDRCONFIG, emulate it by manually
- checking whether the system supports IPv6 sockets and. */
- if (!socket_has_inet6 ())
- hints.ai_family = AF_INET;
-#endif
- }
+
if (flags & LH_BIND)
hints.ai_flags |= AI_PASSIVE;
- err = getaddrinfo_with_timeout (host, NULL, &hints, &res, opt.dns_timeout);
+#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)
_("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
+#else /* not ENABLE_IPV6 */
{
- struct hostent *hptr = gethostbyname_with_timeout (host, opt.dns_timeout);
+ struct hostent *hptr = gethostbyname_with_timeout (host, timeout);
if (!hptr)
{
if (!silent)
/* Do older systems have h_addr_list? */
al = address_list_from_ipv4_addresses (hptr->h_addr_list);
}
-#endif
+#endif /* not ENABLE_IPV6 */
/* Print the addresses determined by DNS lookup, but no more than
three. */
- if (!silent)
+ if (!silent && !numeric_address)
{
int i;
int printmax = al->count <= 3 ? al->count : 3;
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