git-svn-id: svn://10.65.10.50/branches/R_10_00@23289 c028cbd2-c16b-5b4b-a496-9718f37d4682
		
			
				
	
	
		
			880 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			880 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/***************************************************************************
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 *                                  _   _ ____  _
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 *  Project                     ___| | | |  _ \| |
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 *                             / __| | | | |_) | |
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 *                            | (__| |_| |  _ <| |___
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 *                             \___|\___/|_| \_\_____|
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 *
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 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
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 *
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 * This software is licensed as described in the file COPYING, which
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 * you should have received as part of this distribution. The terms
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 * are also available at http://curl.haxx.se/docs/copyright.html.
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 *
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 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
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 * copies of the Software, and permit persons to whom the Software is
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 * furnished to do so, under the terms of the COPYING file.
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 *
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 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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 * KIND, either express or implied.
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 *
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 ***************************************************************************/
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#include "curl_setup.h"
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#ifdef HAVE_NETINET_IN_H
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#include <netinet/in.h>
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#endif
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#ifdef HAVE_NETDB_H
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#include <netdb.h>
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#endif
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#ifdef HAVE_ARPA_INET_H
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#include <arpa/inet.h>
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#endif
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#ifdef __VMS
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#include <in.h>
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#include <inet.h>
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#endif
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#ifdef HAVE_SETJMP_H
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#include <setjmp.h>
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#endif
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#ifdef HAVE_SIGNAL_H
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#include <signal.h>
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#endif
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#ifdef HAVE_PROCESS_H
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#include <process.h>
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#endif
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#include "urldata.h"
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#include "sendf.h"
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#include "hostip.h"
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#include "hash.h"
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#include "share.h"
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#include "strerror.h"
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#include "url.h"
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#include "inet_ntop.h"
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#include "warnless.h"
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#include "curl_printf.h"
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#include "curl_memory.h"
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/* The last #include file should be: */
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#include "memdebug.h"
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#if defined(CURLRES_SYNCH) && \
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    defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP)
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/* alarm-based timeouts can only be used with all the dependencies satisfied */
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#define USE_ALARM_TIMEOUT
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#endif
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/*
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 * hostip.c explained
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 * ==================
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 *
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 * The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c
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 * source file are these:
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 *
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 * CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use
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 * that. The host may not be able to resolve IPv6, but we don't really have to
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 * take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4
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 * defined.
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 *
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 * CURLRES_ARES - is defined if libcurl is built to use c-ares for
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 * asynchronous name resolves. This can be Windows or *nix.
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 *
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 * CURLRES_THREADED - is defined if libcurl is built to run under (native)
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 * Windows, and then the name resolve will be done in a new thread, and the
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 * supported API will be the same as for ares-builds.
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 *
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 * If any of the two previous are defined, CURLRES_ASYNCH is defined too. If
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 * libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is
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 * defined.
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 *
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 * The host*.c sources files are split up like this:
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 *
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 * hostip.c   - method-independent resolver functions and utility functions
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 * hostasyn.c - functions for asynchronous name resolves
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 * hostsyn.c  - functions for synchronous name resolves
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 * hostip4.c  - IPv4 specific functions
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 * hostip6.c  - IPv6 specific functions
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 *
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 * The two asynchronous name resolver backends are implemented in:
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 * asyn-ares.c   - functions for ares-using name resolves
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 * asyn-thread.c - functions for threaded name resolves
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 * The hostip.h is the united header file for all this. It defines the
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 * CURLRES_* defines based on the config*.h and curl_setup.h defines.
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 */
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/* These two symbols are for the global DNS cache */
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static struct curl_hash hostname_cache;
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static int host_cache_initialized;
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static void freednsentry(void *freethis);
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/*
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 * Curl_global_host_cache_init() initializes and sets up a global DNS cache.
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 * Global DNS cache is general badness. Do not use. This will be removed in
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 * a future version. Use the share interface instead!
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 *
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 * Returns a struct curl_hash pointer on success, NULL on failure.
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 */
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struct curl_hash *Curl_global_host_cache_init(void)
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{
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  int rc = 0;
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  if(!host_cache_initialized) {
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    rc = Curl_hash_init(&hostname_cache, 7, Curl_hash_str,
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                        Curl_str_key_compare, freednsentry);
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    if(!rc)
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      host_cache_initialized = 1;
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  }
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  return rc?NULL:&hostname_cache;
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}
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/*
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 * Destroy and cleanup the global DNS cache
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 */
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void Curl_global_host_cache_dtor(void)
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{
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  if(host_cache_initialized) {
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    Curl_hash_clean(&hostname_cache);
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    host_cache_initialized = 0;
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  }
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}
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/*
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 * Return # of adresses in a Curl_addrinfo struct
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 */
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int Curl_num_addresses(const Curl_addrinfo *addr)
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{
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  int i = 0;
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  while(addr) {
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    addr = addr->ai_next;
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    i++;
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  }
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  return i;
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}
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/*
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 * Curl_printable_address() returns a printable version of the 1st address
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 * given in the 'ai' argument. The result will be stored in the buf that is
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 * bufsize bytes big.
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 *
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 * If the conversion fails, it returns NULL.
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 */
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const char *
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Curl_printable_address(const Curl_addrinfo *ai, char *buf, size_t bufsize)
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{
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  const struct sockaddr_in *sa4;
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  const struct in_addr *ipaddr4;
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#ifdef ENABLE_IPV6
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  const struct sockaddr_in6 *sa6;
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  const struct in6_addr *ipaddr6;
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#endif
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  switch (ai->ai_family) {
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    case AF_INET:
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      sa4 = (const void *)ai->ai_addr;
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      ipaddr4 = &sa4->sin_addr;
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      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf,
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                            bufsize);
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#ifdef ENABLE_IPV6
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    case AF_INET6:
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      sa6 = (const void *)ai->ai_addr;
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      ipaddr6 = &sa6->sin6_addr;
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      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf,
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                            bufsize);
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#endif
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    default:
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      break;
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  }
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  return NULL;
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}
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/*
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 * Return a hostcache id string for the provided host + port, to be used by
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 * the DNS caching.
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 */
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static char *
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create_hostcache_id(const char *name, int port)
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{
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  /* create and return the new allocated entry */
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  char *id = aprintf("%s:%d", name, port);
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  char *ptr = id;
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  if(ptr) {
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    /* lower case the name part */
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    while(*ptr && (*ptr != ':')) {
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      *ptr = (char)TOLOWER(*ptr);
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      ptr++;
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    }
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  }
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  return id;
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}
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struct hostcache_prune_data {
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  long cache_timeout;
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  time_t now;
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};
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/*
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 * This function is set as a callback to be called for every entry in the DNS
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 * cache when we want to prune old unused entries.
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 *
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 * Returning non-zero means remove the entry, return 0 to keep it in the
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 * cache.
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 */
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static int
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hostcache_timestamp_remove(void *datap, void *hc)
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{
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  struct hostcache_prune_data *data =
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    (struct hostcache_prune_data *) datap;
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  struct Curl_dns_entry *c = (struct Curl_dns_entry *) hc;
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  return (0 != c->timestamp)
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    && (data->now - c->timestamp >= data->cache_timeout);
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}
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/*
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 * Prune the DNS cache. This assumes that a lock has already been taken.
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 */
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static void
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hostcache_prune(struct curl_hash *hostcache, long cache_timeout, time_t now)
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{
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  struct hostcache_prune_data user;
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  user.cache_timeout = cache_timeout;
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  user.now = now;
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  Curl_hash_clean_with_criterium(hostcache,
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                                 (void *) &user,
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                                 hostcache_timestamp_remove);
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}
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/*
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 * Library-wide function for pruning the DNS cache. This function takes and
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 * returns the appropriate locks.
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 */
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void Curl_hostcache_prune(struct SessionHandle *data)
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{
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  time_t now;
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  if((data->set.dns_cache_timeout == -1) || !data->dns.hostcache)
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    /* cache forever means never prune, and NULL hostcache means
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       we can't do it */
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    return;
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  if(data->share)
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    Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
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  time(&now);
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  /* Remove outdated and unused entries from the hostcache */
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  hostcache_prune(data->dns.hostcache,
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                  data->set.dns_cache_timeout,
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                  now);
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  if(data->share)
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    Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
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}
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#ifdef HAVE_SIGSETJMP
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/* Beware this is a global and unique instance. This is used to store the
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   return address that we can jump back to from inside a signal handler. This
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   is not thread-safe stuff. */
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sigjmp_buf curl_jmpenv;
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#endif
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/* lookup address, returns entry if found and not stale */
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static struct Curl_dns_entry *
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fetch_addr(struct connectdata *conn,
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                const char *hostname,
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                int port)
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{
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  char *entry_id = NULL;
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  struct Curl_dns_entry *dns = NULL;
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						|
  size_t entry_len;
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  struct SessionHandle *data = conn->data;
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  /* Create an entry id, based upon the hostname and port */
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  entry_id = create_hostcache_id(hostname, port);
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  /* If we can't create the entry id, fail */
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						|
  if(!entry_id)
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    return dns;
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  entry_len = strlen(entry_id);
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  /* See if its already in our dns cache */
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  dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
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  if(dns && (data->set.dns_cache_timeout != -1))  {
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    /* See whether the returned entry is stale. Done before we release lock */
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    struct hostcache_prune_data user;
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    time(&user.now);
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    user.cache_timeout = data->set.dns_cache_timeout;
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    if(hostcache_timestamp_remove(&user, dns)) {
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      infof(data, "Hostname in DNS cache was stale, zapped\n");
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      dns = NULL; /* the memory deallocation is being handled by the hash */
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      Curl_hash_delete(data->dns.hostcache, entry_id, entry_len+1);
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    }
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  }
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  /* free the allocated entry_id again */
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  free(entry_id);
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  return dns;
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}
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 | 
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/*
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 * Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache.
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 *
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 * Curl_resolv() checks initially and multi_runsingle() checks each time
 | 
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 * it discovers the handle in the state WAITRESOLVE whether the hostname
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 * has already been resolved and the address has already been stored in
 | 
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 * the DNS cache. This short circuits waiting for a lot of pending
 | 
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 * lookups for the same hostname requested by different handles.
 | 
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 *
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 * Returns the Curl_dns_entry entry pointer or NULL if not in the cache.
 | 
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 *
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 * The returned data *MUST* be "unlocked" with Curl_resolv_unlock() after
 | 
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 * use, or we'll leak memory!
 | 
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 */
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struct Curl_dns_entry *
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Curl_fetch_addr(struct connectdata *conn,
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                const char *hostname,
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                int port)
 | 
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{
 | 
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  struct SessionHandle *data = conn->data;
 | 
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  struct Curl_dns_entry *dns = NULL;
 | 
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 | 
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  if(data->share)
 | 
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    Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
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  dns = fetch_addr(conn, hostname, port);
 | 
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 | 
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  if(dns) dns->inuse++; /* we use it! */
 | 
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 | 
						|
  if(data->share)
 | 
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    Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
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 | 
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  return dns;
 | 
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}
 | 
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 | 
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/*
 | 
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 * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
 | 
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 *
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 * When calling Curl_resolv() has resulted in a response with a returned
 | 
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 * address, we call this function to store the information in the dns
 | 
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 * cache etc
 | 
						|
 *
 | 
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 * Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
 | 
						|
 */
 | 
						|
struct Curl_dns_entry *
 | 
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Curl_cache_addr(struct SessionHandle *data,
 | 
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                Curl_addrinfo *addr,
 | 
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                const char *hostname,
 | 
						|
                int port)
 | 
						|
{
 | 
						|
  char *entry_id;
 | 
						|
  size_t entry_len;
 | 
						|
  struct Curl_dns_entry *dns;
 | 
						|
  struct Curl_dns_entry *dns2;
 | 
						|
 | 
						|
  /* Create an entry id, based upon the hostname and port */
 | 
						|
  entry_id = create_hostcache_id(hostname, port);
 | 
						|
  /* If we can't create the entry id, fail */
 | 
						|
  if(!entry_id)
 | 
						|
    return NULL;
 | 
						|
  entry_len = strlen(entry_id);
 | 
						|
 | 
						|
  /* Create a new cache entry */
 | 
						|
  dns = calloc(1, sizeof(struct Curl_dns_entry));
 | 
						|
  if(!dns) {
 | 
						|
    free(entry_id);
 | 
						|
    return NULL;
 | 
						|
  }
 | 
						|
 | 
						|
  dns->inuse = 1;   /* the cache has the first reference */
 | 
						|
  dns->addr = addr; /* this is the address(es) */
 | 
						|
  time(&dns->timestamp);
 | 
						|
  if(dns->timestamp == 0)
 | 
						|
    dns->timestamp = 1;   /* zero indicates CURLOPT_RESOLVE entry */
 | 
						|
 | 
						|
  /* Store the resolved data in our DNS cache. */
 | 
						|
  dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len+1,
 | 
						|
                       (void *)dns);
 | 
						|
  if(!dns2) {
 | 
						|
    free(dns);
 | 
						|
    free(entry_id);
 | 
						|
    return NULL;
 | 
						|
  }
 | 
						|
 | 
						|
  dns = dns2;
 | 
						|
  dns->inuse++;         /* mark entry as in-use */
 | 
						|
 | 
						|
  /* free the allocated entry_id */
 | 
						|
  free(entry_id);
 | 
						|
 | 
						|
  return dns;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Curl_resolv() is the main name resolve function within libcurl. It resolves
 | 
						|
 * a name and returns a pointer to the entry in the 'entry' argument (if one
 | 
						|
 * is provided). This function might return immediately if we're using asynch
 | 
						|
 * resolves. See the return codes.
 | 
						|
 *
 | 
						|
 * The cache entry we return will get its 'inuse' counter increased when this
 | 
						|
 * function is used. You MUST call Curl_resolv_unlock() later (when you're
 | 
						|
 * done using this struct) to decrease the counter again.
 | 
						|
 *
 | 
						|
 * In debug mode, we specifically test for an interface name "LocalHost"
 | 
						|
 * and resolve "localhost" instead as a means to permit test cases
 | 
						|
 * to connect to a local test server with any host name.
 | 
						|
 *
 | 
						|
 * Return codes:
 | 
						|
 *
 | 
						|
 * CURLRESOLV_ERROR   (-1) = error, no pointer
 | 
						|
 * CURLRESOLV_RESOLVED (0) = OK, pointer provided
 | 
						|
 * CURLRESOLV_PENDING  (1) = waiting for response, no pointer
 | 
						|
 */
 | 
						|
 | 
						|
int Curl_resolv(struct connectdata *conn,
 | 
						|
                const char *hostname,
 | 
						|
                int port,
 | 
						|
                struct Curl_dns_entry **entry)
 | 
						|
{
 | 
						|
  struct Curl_dns_entry *dns = NULL;
 | 
						|
  struct SessionHandle *data = conn->data;
 | 
						|
  CURLcode result;
 | 
						|
  int rc = CURLRESOLV_ERROR; /* default to failure */
 | 
						|
 | 
						|
  *entry = NULL;
 | 
						|
 | 
						|
  if(data->share)
 | 
						|
    Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
  dns = fetch_addr(conn, hostname, port);
 | 
						|
 | 
						|
  if(dns) {
 | 
						|
    infof(data, "Hostname %s was found in DNS cache\n", hostname);
 | 
						|
    dns->inuse++; /* we use it! */
 | 
						|
    rc = CURLRESOLV_RESOLVED;
 | 
						|
  }
 | 
						|
 | 
						|
  if(data->share)
 | 
						|
    Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
 | 
						|
  if(!dns) {
 | 
						|
    /* The entry was not in the cache. Resolve it to IP address */
 | 
						|
 | 
						|
    Curl_addrinfo *addr;
 | 
						|
    int respwait;
 | 
						|
 | 
						|
    /* Check what IP specifics the app has requested and if we can provide it.
 | 
						|
     * If not, bail out. */
 | 
						|
    if(!Curl_ipvalid(conn))
 | 
						|
      return CURLRESOLV_ERROR;
 | 
						|
 | 
						|
    /* If Curl_getaddrinfo() returns NULL, 'respwait' might be set to a
 | 
						|
       non-zero value indicating that we need to wait for the response to the
 | 
						|
       resolve call */
 | 
						|
    addr = Curl_getaddrinfo(conn,
 | 
						|
#ifdef DEBUGBUILD
 | 
						|
                            (data->set.str[STRING_DEVICE]
 | 
						|
                             && !strcmp(data->set.str[STRING_DEVICE],
 | 
						|
                                        "LocalHost"))?"localhost":
 | 
						|
#endif
 | 
						|
                            hostname, port, &respwait);
 | 
						|
 | 
						|
    if(!addr) {
 | 
						|
      if(respwait) {
 | 
						|
        /* the response to our resolve call will come asynchronously at
 | 
						|
           a later time, good or bad */
 | 
						|
        /* First, check that we haven't received the info by now */
 | 
						|
        result = Curl_resolver_is_resolved(conn, &dns);
 | 
						|
        if(result) /* error detected */
 | 
						|
          return CURLRESOLV_ERROR;
 | 
						|
        if(dns)
 | 
						|
          rc = CURLRESOLV_RESOLVED; /* pointer provided */
 | 
						|
        else
 | 
						|
          rc = CURLRESOLV_PENDING; /* no info yet */
 | 
						|
      }
 | 
						|
    }
 | 
						|
    else {
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
      /* we got a response, store it in the cache */
 | 
						|
      dns = Curl_cache_addr(data, addr, hostname, port);
 | 
						|
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
 | 
						|
      if(!dns)
 | 
						|
        /* returned failure, bail out nicely */
 | 
						|
        Curl_freeaddrinfo(addr);
 | 
						|
      else
 | 
						|
        rc = CURLRESOLV_RESOLVED;
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  *entry = dns;
 | 
						|
 | 
						|
  return rc;
 | 
						|
}
 | 
						|
 | 
						|
#ifdef USE_ALARM_TIMEOUT
 | 
						|
/*
 | 
						|
 * This signal handler jumps back into the main libcurl code and continues
 | 
						|
 * execution.  This effectively causes the remainder of the application to run
 | 
						|
 * within a signal handler which is nonportable and could lead to problems.
 | 
						|
 */
 | 
						|
static
 | 
						|
RETSIGTYPE alarmfunc(int sig)
 | 
						|
{
 | 
						|
  /* this is for "-ansi -Wall -pedantic" to stop complaining!   (rabe) */
 | 
						|
  (void)sig;
 | 
						|
  siglongjmp(curl_jmpenv, 1);
 | 
						|
  return;
 | 
						|
}
 | 
						|
#endif /* USE_ALARM_TIMEOUT */
 | 
						|
 | 
						|
/*
 | 
						|
 * Curl_resolv_timeout() is the same as Curl_resolv() but specifies a
 | 
						|
 * timeout.  This function might return immediately if we're using asynch
 | 
						|
 * resolves. See the return codes.
 | 
						|
 *
 | 
						|
 * The cache entry we return will get its 'inuse' counter increased when this
 | 
						|
 * function is used. You MUST call Curl_resolv_unlock() later (when you're
 | 
						|
 * done using this struct) to decrease the counter again.
 | 
						|
 *
 | 
						|
 * If built with a synchronous resolver and use of signals is not
 | 
						|
 * disabled by the application, then a nonzero timeout will cause a
 | 
						|
 * timeout after the specified number of milliseconds. Otherwise, timeout
 | 
						|
 * is ignored.
 | 
						|
 *
 | 
						|
 * Return codes:
 | 
						|
 *
 | 
						|
 * CURLRESOLV_TIMEDOUT(-2) = warning, time too short or previous alarm expired
 | 
						|
 * CURLRESOLV_ERROR   (-1) = error, no pointer
 | 
						|
 * CURLRESOLV_RESOLVED (0) = OK, pointer provided
 | 
						|
 * CURLRESOLV_PENDING  (1) = waiting for response, no pointer
 | 
						|
 */
 | 
						|
 | 
						|
int Curl_resolv_timeout(struct connectdata *conn,
 | 
						|
                        const char *hostname,
 | 
						|
                        int port,
 | 
						|
                        struct Curl_dns_entry **entry,
 | 
						|
                        long timeoutms)
 | 
						|
{
 | 
						|
#ifdef USE_ALARM_TIMEOUT
 | 
						|
#ifdef HAVE_SIGACTION
 | 
						|
  struct sigaction keep_sigact;   /* store the old struct here */
 | 
						|
  volatile bool keep_copysig = FALSE; /* wether old sigact has been saved */
 | 
						|
  struct sigaction sigact;
 | 
						|
#else
 | 
						|
#ifdef HAVE_SIGNAL
 | 
						|
  void (*keep_sigact)(int);       /* store the old handler here */
 | 
						|
#endif /* HAVE_SIGNAL */
 | 
						|
#endif /* HAVE_SIGACTION */
 | 
						|
  volatile long timeout;
 | 
						|
  volatile unsigned int prev_alarm = 0;
 | 
						|
  struct SessionHandle *data = conn->data;
 | 
						|
#endif /* USE_ALARM_TIMEOUT */
 | 
						|
  int rc;
 | 
						|
 | 
						|
  *entry = NULL;
 | 
						|
 | 
						|
  if(timeoutms < 0)
 | 
						|
    /* got an already expired timeout */
 | 
						|
    return CURLRESOLV_TIMEDOUT;
 | 
						|
 | 
						|
#ifdef USE_ALARM_TIMEOUT
 | 
						|
  if(data->set.no_signal)
 | 
						|
    /* Ignore the timeout when signals are disabled */
 | 
						|
    timeout = 0;
 | 
						|
  else
 | 
						|
    timeout = timeoutms;
 | 
						|
 | 
						|
  if(!timeout)
 | 
						|
    /* USE_ALARM_TIMEOUT defined, but no timeout actually requested */
 | 
						|
    return Curl_resolv(conn, hostname, port, entry);
 | 
						|
 | 
						|
  if(timeout < 1000)
 | 
						|
    /* The alarm() function only provides integer second resolution, so if
 | 
						|
       we want to wait less than one second we must bail out already now. */
 | 
						|
    return CURLRESOLV_TIMEDOUT;
 | 
						|
 | 
						|
  /* This allows us to time-out from the name resolver, as the timeout
 | 
						|
     will generate a signal and we will siglongjmp() from that here.
 | 
						|
     This technique has problems (see alarmfunc).
 | 
						|
     This should be the last thing we do before calling Curl_resolv(),
 | 
						|
     as otherwise we'd have to worry about variables that get modified
 | 
						|
     before we invoke Curl_resolv() (and thus use "volatile"). */
 | 
						|
  if(sigsetjmp(curl_jmpenv, 1)) {
 | 
						|
    /* this is coming from a siglongjmp() after an alarm signal */
 | 
						|
    failf(data, "name lookup timed out");
 | 
						|
    rc = CURLRESOLV_ERROR;
 | 
						|
    goto clean_up;
 | 
						|
  }
 | 
						|
  else {
 | 
						|
    /*************************************************************
 | 
						|
     * Set signal handler to catch SIGALRM
 | 
						|
     * Store the old value to be able to set it back later!
 | 
						|
     *************************************************************/
 | 
						|
#ifdef HAVE_SIGACTION
 | 
						|
    sigaction(SIGALRM, NULL, &sigact);
 | 
						|
    keep_sigact = sigact;
 | 
						|
    keep_copysig = TRUE; /* yes, we have a copy */
 | 
						|
    sigact.sa_handler = alarmfunc;
 | 
						|
#ifdef SA_RESTART
 | 
						|
    /* HPUX doesn't have SA_RESTART but defaults to that behaviour! */
 | 
						|
    sigact.sa_flags &= ~SA_RESTART;
 | 
						|
#endif
 | 
						|
    /* now set the new struct */
 | 
						|
    sigaction(SIGALRM, &sigact, NULL);
 | 
						|
#else /* HAVE_SIGACTION */
 | 
						|
    /* no sigaction(), revert to the much lamer signal() */
 | 
						|
#ifdef HAVE_SIGNAL
 | 
						|
    keep_sigact = signal(SIGALRM, alarmfunc);
 | 
						|
#endif
 | 
						|
#endif /* HAVE_SIGACTION */
 | 
						|
 | 
						|
    /* alarm() makes a signal get sent when the timeout fires off, and that
 | 
						|
       will abort system calls */
 | 
						|
    prev_alarm = alarm(curlx_sltoui(timeout/1000L));
 | 
						|
  }
 | 
						|
 | 
						|
#else
 | 
						|
#ifndef CURLRES_ASYNCH
 | 
						|
  if(timeoutms)
 | 
						|
    infof(conn->data, "timeout on name lookup is not supported\n");
 | 
						|
#else
 | 
						|
  (void)timeoutms; /* timeoutms not used with an async resolver */
 | 
						|
#endif
 | 
						|
#endif /* USE_ALARM_TIMEOUT */
 | 
						|
 | 
						|
  /* Perform the actual name resolution. This might be interrupted by an
 | 
						|
   * alarm if it takes too long.
 | 
						|
   */
 | 
						|
  rc = Curl_resolv(conn, hostname, port, entry);
 | 
						|
 | 
						|
#ifdef USE_ALARM_TIMEOUT
 | 
						|
clean_up:
 | 
						|
 | 
						|
  if(!prev_alarm)
 | 
						|
    /* deactivate a possibly active alarm before uninstalling the handler */
 | 
						|
    alarm(0);
 | 
						|
 | 
						|
#ifdef HAVE_SIGACTION
 | 
						|
  if(keep_copysig) {
 | 
						|
    /* we got a struct as it looked before, now put that one back nice
 | 
						|
       and clean */
 | 
						|
    sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */
 | 
						|
  }
 | 
						|
#else
 | 
						|
#ifdef HAVE_SIGNAL
 | 
						|
  /* restore the previous SIGALRM handler */
 | 
						|
  signal(SIGALRM, keep_sigact);
 | 
						|
#endif
 | 
						|
#endif /* HAVE_SIGACTION */
 | 
						|
 | 
						|
  /* switch back the alarm() to either zero or to what it was before minus
 | 
						|
     the time we spent until now! */
 | 
						|
  if(prev_alarm) {
 | 
						|
    /* there was an alarm() set before us, now put it back */
 | 
						|
    unsigned long elapsed_ms = Curl_tvdiff(Curl_tvnow(), conn->created);
 | 
						|
 | 
						|
    /* the alarm period is counted in even number of seconds */
 | 
						|
    unsigned long alarm_set = prev_alarm - elapsed_ms/1000;
 | 
						|
 | 
						|
    if(!alarm_set ||
 | 
						|
       ((alarm_set >= 0x80000000) && (prev_alarm < 0x80000000)) ) {
 | 
						|
      /* if the alarm time-left reached zero or turned "negative" (counted
 | 
						|
         with unsigned values), we should fire off a SIGALRM here, but we
 | 
						|
         won't, and zero would be to switch it off so we never set it to
 | 
						|
         less than 1! */
 | 
						|
      alarm(1);
 | 
						|
      rc = CURLRESOLV_TIMEDOUT;
 | 
						|
      failf(data, "Previous alarm fired off!");
 | 
						|
    }
 | 
						|
    else
 | 
						|
      alarm((unsigned int)alarm_set);
 | 
						|
  }
 | 
						|
#endif /* USE_ALARM_TIMEOUT */
 | 
						|
 | 
						|
  return rc;
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Curl_resolv_unlock() unlocks the given cached DNS entry. When this has been
 | 
						|
 * made, the struct may be destroyed due to pruning. It is important that only
 | 
						|
 * one unlock is made for each Curl_resolv() call.
 | 
						|
 *
 | 
						|
 * May be called with 'data' == NULL for global cache.
 | 
						|
 */
 | 
						|
void Curl_resolv_unlock(struct SessionHandle *data, struct Curl_dns_entry *dns)
 | 
						|
{
 | 
						|
  if(data && data->share)
 | 
						|
    Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
  freednsentry(dns);
 | 
						|
 | 
						|
  if(data && data->share)
 | 
						|
    Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * File-internal: release cache dns entry reference, free if inuse drops to 0
 | 
						|
 */
 | 
						|
static void freednsentry(void *freethis)
 | 
						|
{
 | 
						|
  struct Curl_dns_entry *dns = (struct Curl_dns_entry *) freethis;
 | 
						|
  DEBUGASSERT(dns && (dns->inuse>0));
 | 
						|
 | 
						|
  dns->inuse--;
 | 
						|
  if(dns->inuse == 0) {
 | 
						|
    Curl_freeaddrinfo(dns->addr);
 | 
						|
    free(dns);
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Curl_mk_dnscache() creates a new DNS cache and returns the handle for it.
 | 
						|
 */
 | 
						|
struct curl_hash *Curl_mk_dnscache(void)
 | 
						|
{
 | 
						|
  return Curl_hash_alloc(7, Curl_hash_str, Curl_str_key_compare, freednsentry);
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
 * Curl_hostcache_clean()
 | 
						|
 *
 | 
						|
 * This _can_ be called with 'data' == NULL but then of course no locking
 | 
						|
 * can be done!
 | 
						|
 */
 | 
						|
 | 
						|
void Curl_hostcache_clean(struct SessionHandle *data,
 | 
						|
                          struct curl_hash *hash)
 | 
						|
{
 | 
						|
  if(data && data->share)
 | 
						|
    Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
  Curl_hash_clean(hash);
 | 
						|
 | 
						|
  if(data && data->share)
 | 
						|
    Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
CURLcode Curl_loadhostpairs(struct SessionHandle *data)
 | 
						|
{
 | 
						|
  struct curl_slist *hostp;
 | 
						|
  char hostname[256];
 | 
						|
  char address[256];
 | 
						|
  int port;
 | 
						|
 | 
						|
  for(hostp = data->change.resolve; hostp; hostp = hostp->next ) {
 | 
						|
    if(!hostp->data)
 | 
						|
      continue;
 | 
						|
    if(hostp->data[0] == '-') {
 | 
						|
      char *entry_id;
 | 
						|
      size_t entry_len;
 | 
						|
 | 
						|
      if(2 != sscanf(hostp->data + 1, "%255[^:]:%d", hostname, &port)) {
 | 
						|
        infof(data, "Couldn't parse CURLOPT_RESOLVE removal entry '%s'!\n",
 | 
						|
              hostp->data);
 | 
						|
        continue;
 | 
						|
      }
 | 
						|
 | 
						|
      /* Create an entry id, based upon the hostname and port */
 | 
						|
      entry_id = create_hostcache_id(hostname, port);
 | 
						|
      /* If we can't create the entry id, fail */
 | 
						|
      if(!entry_id) {
 | 
						|
        return CURLE_OUT_OF_MEMORY;
 | 
						|
      }
 | 
						|
 | 
						|
      entry_len = strlen(entry_id);
 | 
						|
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
      /* delete entry, ignore if it didn't exist */
 | 
						|
      Curl_hash_delete(data->dns.hostcache, entry_id, entry_len+1);
 | 
						|
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
 | 
						|
      /* free the allocated entry_id again */
 | 
						|
      free(entry_id);
 | 
						|
    }
 | 
						|
    else {
 | 
						|
      struct Curl_dns_entry *dns;
 | 
						|
      Curl_addrinfo *addr;
 | 
						|
      char *entry_id;
 | 
						|
      size_t entry_len;
 | 
						|
 | 
						|
      if(3 != sscanf(hostp->data, "%255[^:]:%d:%255s", hostname, &port,
 | 
						|
                     address)) {
 | 
						|
        infof(data, "Couldn't parse CURLOPT_RESOLVE entry '%s'!\n",
 | 
						|
              hostp->data);
 | 
						|
        continue;
 | 
						|
      }
 | 
						|
 | 
						|
      addr = Curl_str2addr(address, port);
 | 
						|
      if(!addr) {
 | 
						|
        infof(data, "Address in '%s' found illegal!\n", hostp->data);
 | 
						|
        continue;
 | 
						|
      }
 | 
						|
 | 
						|
      /* Create an entry id, based upon the hostname and port */
 | 
						|
      entry_id = create_hostcache_id(hostname, port);
 | 
						|
      /* If we can't create the entry id, fail */
 | 
						|
      if(!entry_id) {
 | 
						|
        Curl_freeaddrinfo(addr);
 | 
						|
        return CURLE_OUT_OF_MEMORY;
 | 
						|
      }
 | 
						|
 | 
						|
      entry_len = strlen(entry_id);
 | 
						|
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 | 
						|
 | 
						|
      /* See if its already in our dns cache */
 | 
						|
      dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
 | 
						|
 | 
						|
      /* free the allocated entry_id again */
 | 
						|
      free(entry_id);
 | 
						|
 | 
						|
      if(!dns) {
 | 
						|
        /* if not in the cache already, put this host in the cache */
 | 
						|
        dns = Curl_cache_addr(data, addr, hostname, port);
 | 
						|
        if(dns) {
 | 
						|
          dns->timestamp = 0; /* mark as added by CURLOPT_RESOLVE */
 | 
						|
          /* release the returned reference; the cache itself will keep the
 | 
						|
           * entry alive: */
 | 
						|
          dns->inuse--;
 | 
						|
        }
 | 
						|
      }
 | 
						|
      else
 | 
						|
        /* this is a duplicate, free it again */
 | 
						|
        Curl_freeaddrinfo(addr);
 | 
						|
 | 
						|
      if(data->share)
 | 
						|
        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 | 
						|
 | 
						|
      if(!dns) {
 | 
						|
        Curl_freeaddrinfo(addr);
 | 
						|
        return CURLE_OUT_OF_MEMORY;
 | 
						|
      }
 | 
						|
      infof(data, "Added %s:%d:%s to DNS cache\n",
 | 
						|
            hostname, port, address);
 | 
						|
    }
 | 
						|
  }
 | 
						|
  data->change.resolve = NULL; /* dealt with now */
 | 
						|
 | 
						|
  return CURLE_OK;
 | 
						|
}
 |