933 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			933 lines
		
	
	
		
			28 KiB
		
	
	
	
		
			C
		
	
	
	
| /***************************************************************************
 | |
|  *                                  _   _ ____  _
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|  *  Project                     ___| | | |  _ \| |
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|  *                             / __| | | | |_) | |
 | |
|  *                            | (__| |_| |  _ <| |___
 | |
|  *                             \___|\___/|_| \_\_____|
 | |
|  *
 | |
|  * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
 | |
|  *
 | |
|  * This software is licensed as described in the file COPYING, which
 | |
|  * you should have received as part of this distribution. The terms
 | |
|  * are also available at https://curl.se/docs/copyright.html.
 | |
|  *
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|  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 | |
|  * copies of the Software, and permit persons to whom the Software is
 | |
|  * furnished to do so, under the terms of the COPYING file.
 | |
|  *
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|  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 | |
|  * KIND, either express or implied.
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|  *
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|  ***************************************************************************/
 | |
| 
 | |
| #include "curl_setup.h"
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| 
 | |
| /***********************************************************************
 | |
|  * Only for ares-enabled builds
 | |
|  * And only for functions that fulfill the asynch resolver backend API
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|  * as defined in asyn.h, nothing else belongs in this file!
 | |
|  **********************************************************************/
 | |
| 
 | |
| #ifdef CURLRES_ARES
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| 
 | |
| #include <limits.h>
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| #ifdef HAVE_NETINET_IN_H
 | |
| #include <netinet/in.h>
 | |
| #endif
 | |
| #ifdef HAVE_NETDB_H
 | |
| #include <netdb.h>
 | |
| #endif
 | |
| #ifdef HAVE_ARPA_INET_H
 | |
| #include <arpa/inet.h>
 | |
| #endif
 | |
| #ifdef __VMS
 | |
| #include <in.h>
 | |
| #include <inet.h>
 | |
| #endif
 | |
| 
 | |
| #ifdef HAVE_PROCESS_H
 | |
| #include <process.h>
 | |
| #endif
 | |
| 
 | |
| #if (defined(NETWARE) && defined(__NOVELL_LIBC__))
 | |
| #undef in_addr_t
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| #define in_addr_t unsigned long
 | |
| #endif
 | |
| 
 | |
| #include "urldata.h"
 | |
| #include "sendf.h"
 | |
| #include "hostip.h"
 | |
| #include "hash.h"
 | |
| #include "share.h"
 | |
| #include "url.h"
 | |
| #include "multiif.h"
 | |
| #include "inet_pton.h"
 | |
| #include "connect.h"
 | |
| #include "select.h"
 | |
| #include "progress.h"
 | |
| 
 | |
| #  if defined(CURL_STATICLIB) && !defined(CARES_STATICLIB) &&   \
 | |
|   defined(WIN32)
 | |
| #    define CARES_STATICLIB
 | |
| #  endif
 | |
| #  include <ares.h>
 | |
| #  include <ares_version.h> /* really old c-ares didn't include this by
 | |
|                                itself */
 | |
| 
 | |
| #if ARES_VERSION >= 0x010500
 | |
| /* c-ares 1.5.0 or later, the callback proto is modified */
 | |
| #define HAVE_CARES_CALLBACK_TIMEOUTS 1
 | |
| #endif
 | |
| 
 | |
| #if ARES_VERSION >= 0x010601
 | |
| /* IPv6 supported since 1.6.1 */
 | |
| #define HAVE_CARES_IPV6 1
 | |
| #endif
 | |
| 
 | |
| #if ARES_VERSION >= 0x010704
 | |
| #define HAVE_CARES_SERVERS_CSV 1
 | |
| #define HAVE_CARES_LOCAL_DEV 1
 | |
| #define HAVE_CARES_SET_LOCAL 1
 | |
| #endif
 | |
| 
 | |
| #if ARES_VERSION >= 0x010b00
 | |
| #define HAVE_CARES_PORTS_CSV 1
 | |
| #endif
 | |
| 
 | |
| #if ARES_VERSION >= 0x011000
 | |
| /* 1.16.0 or later has ares_getaddrinfo */
 | |
| #define HAVE_CARES_GETADDRINFO 1
 | |
| #endif
 | |
| 
 | |
| /* The last 3 #include files should be in this order */
 | |
| #include "curl_printf.h"
 | |
| #include "curl_memory.h"
 | |
| #include "memdebug.h"
 | |
| 
 | |
| struct thread_data {
 | |
|   int num_pending; /* number of outstanding c-ares requests */
 | |
|   struct Curl_addrinfo *temp_ai; /* intermediary result while fetching c-ares
 | |
|                                     parts */
 | |
|   int last_status;
 | |
|   struct curltime happy_eyeballs_dns_time; /* when this timer started, or 0 */
 | |
| };
 | |
| 
 | |
| /* How long we are willing to wait for additional parallel responses after
 | |
|    obtaining a "definitive" one.
 | |
| 
 | |
|    This is intended to equal the c-ares default timeout.  cURL always uses that
 | |
|    default value.  Unfortunately, c-ares doesn't expose its default timeout in
 | |
|    its API, but it is officially documented as 5 seconds.
 | |
| 
 | |
|    See query_completed_cb() for an explanation of how this is used.
 | |
|  */
 | |
| #define HAPPY_EYEBALLS_DNS_TIMEOUT 5000
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_global_init() - the generic low-level asynchronous name
 | |
|  * resolve API.  Called from curl_global_init() to initialize global resolver
 | |
|  * environment.  Initializes ares library.
 | |
|  */
 | |
| int Curl_resolver_global_init(void)
 | |
| {
 | |
| #ifdef CARES_HAVE_ARES_LIBRARY_INIT
 | |
|   if(ares_library_init(ARES_LIB_INIT_ALL)) {
 | |
|     return CURLE_FAILED_INIT;
 | |
|   }
 | |
| #endif
 | |
|   return CURLE_OK;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_global_cleanup()
 | |
|  *
 | |
|  * Called from curl_global_cleanup() to destroy global resolver environment.
 | |
|  * Deinitializes ares library.
 | |
|  */
 | |
| void Curl_resolver_global_cleanup(void)
 | |
| {
 | |
| #ifdef CARES_HAVE_ARES_LIBRARY_CLEANUP
 | |
|   ares_library_cleanup();
 | |
| #endif
 | |
| }
 | |
| 
 | |
| 
 | |
| static void sock_state_cb(void *data, ares_socket_t socket_fd,
 | |
|                           int readable, int writable)
 | |
| {
 | |
|   struct Curl_easy *easy = data;
 | |
|   if(!readable && !writable) {
 | |
|     DEBUGASSERT(easy);
 | |
|     Curl_multi_closed(easy, socket_fd);
 | |
|   }
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_init()
 | |
|  *
 | |
|  * Called from curl_easy_init() -> Curl_open() to initialize resolver
 | |
|  * URL-state specific environment ('resolver' member of the UrlState
 | |
|  * structure).  Fills the passed pointer by the initialized ares_channel.
 | |
|  */
 | |
| CURLcode Curl_resolver_init(struct Curl_easy *easy, void **resolver)
 | |
| {
 | |
|   int status;
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|   struct ares_options options;
 | |
|   int optmask = ARES_OPT_SOCK_STATE_CB;
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|   options.sock_state_cb = sock_state_cb;
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|   options.sock_state_cb_data = easy;
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|   status = ares_init_options((ares_channel*)resolver, &options, optmask);
 | |
|   if(status != ARES_SUCCESS) {
 | |
|     if(status == ARES_ENOMEM)
 | |
|       return CURLE_OUT_OF_MEMORY;
 | |
|     else
 | |
|       return CURLE_FAILED_INIT;
 | |
|   }
 | |
|   return CURLE_OK;
 | |
|   /* make sure that all other returns from this function should destroy the
 | |
|      ares channel before returning error! */
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_cleanup()
 | |
|  *
 | |
|  * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver
 | |
|  * URL-state specific environment ('resolver' member of the UrlState
 | |
|  * structure).  Destroys the ares channel.
 | |
|  */
 | |
| void Curl_resolver_cleanup(void *resolver)
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| {
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|   ares_destroy((ares_channel)resolver);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_duphandle()
 | |
|  *
 | |
|  * Called from curl_easy_duphandle() to duplicate resolver URL-state specific
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|  * environment ('resolver' member of the UrlState structure).  Duplicates the
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|  * 'from' ares channel and passes the resulting channel to the 'to' pointer.
 | |
|  */
 | |
| CURLcode Curl_resolver_duphandle(struct Curl_easy *easy, void **to, void *from)
 | |
| {
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|   (void)from;
 | |
|   /*
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|    * it would be better to call ares_dup instead, but right now
 | |
|    * it is not possible to set 'sock_state_cb_data' outside of
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|    * ares_init_options
 | |
|    */
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|   return Curl_resolver_init(easy, to);
 | |
| }
 | |
| 
 | |
| static void destroy_async_data(struct Curl_async *async);
 | |
| 
 | |
| /*
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|  * Cancel all possibly still on-going resolves for this connection.
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|  */
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| void Curl_resolver_cancel(struct Curl_easy *data)
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| {
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|   DEBUGASSERT(data);
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|   if(data->state.async.resolver)
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|     ares_cancel((ares_channel)data->state.async.resolver);
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|   destroy_async_data(&data->state.async);
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| }
 | |
| 
 | |
| /*
 | |
|  * We're equivalent to Curl_resolver_cancel() for the c-ares resolver.  We
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|  * never block.
 | |
|  */
 | |
| void Curl_resolver_kill(struct Curl_easy *data)
 | |
| {
 | |
|   /* We don't need to check the resolver state because we can be called safely
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|      at any time and we always do the same thing. */
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|   Curl_resolver_cancel(data);
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * destroy_async_data() cleans up async resolver data.
 | |
|  */
 | |
| static void destroy_async_data(struct Curl_async *async)
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| {
 | |
|   free(async->hostname);
 | |
| 
 | |
|   if(async->tdata) {
 | |
|     struct thread_data *res = async->tdata;
 | |
|     if(res) {
 | |
|       if(res->temp_ai) {
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|         Curl_freeaddrinfo(res->temp_ai);
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|         res->temp_ai = NULL;
 | |
|       }
 | |
|       free(res);
 | |
|     }
 | |
|     async->tdata = NULL;
 | |
|   }
 | |
| 
 | |
|   async->hostname = NULL;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_getsock() is called when someone from the outside world
 | |
|  * (using curl_multi_fdset()) wants to get our fd_set setup and we're talking
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|  * with ares. The caller must make sure that this function is only called when
 | |
|  * we have a working ares channel.
 | |
|  *
 | |
|  * Returns: sockets-in-use-bitmap
 | |
|  */
 | |
| 
 | |
| int Curl_resolver_getsock(struct Curl_easy *data,
 | |
|                           curl_socket_t *socks)
 | |
| {
 | |
|   struct timeval maxtime;
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|   struct timeval timebuf;
 | |
|   struct timeval *timeout;
 | |
|   long milli;
 | |
|   int max = ares_getsock((ares_channel)data->state.async.resolver,
 | |
|                          (ares_socket_t *)socks, MAX_SOCKSPEREASYHANDLE);
 | |
| 
 | |
|   maxtime.tv_sec = CURL_TIMEOUT_RESOLVE;
 | |
|   maxtime.tv_usec = 0;
 | |
| 
 | |
|   timeout = ares_timeout((ares_channel)data->state.async.resolver, &maxtime,
 | |
|                          &timebuf);
 | |
|   milli = (timeout->tv_sec * 1000) + (timeout->tv_usec/1000);
 | |
|   if(milli == 0)
 | |
|     milli += 10;
 | |
|   Curl_expire(data, milli, EXPIRE_ASYNC_NAME);
 | |
| 
 | |
|   return max;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * waitperform()
 | |
|  *
 | |
|  * 1) Ask ares what sockets it currently plays with, then
 | |
|  * 2) wait for the timeout period to check for action on ares' sockets.
 | |
|  * 3) tell ares to act on all the sockets marked as "with action"
 | |
|  *
 | |
|  * return number of sockets it worked on
 | |
|  */
 | |
| 
 | |
| static int waitperform(struct Curl_easy *data, timediff_t timeout_ms)
 | |
| {
 | |
|   int nfds;
 | |
|   int bitmask;
 | |
|   ares_socket_t socks[ARES_GETSOCK_MAXNUM];
 | |
|   struct pollfd pfd[ARES_GETSOCK_MAXNUM];
 | |
|   int i;
 | |
|   int num = 0;
 | |
| 
 | |
|   bitmask = ares_getsock((ares_channel)data->state.async.resolver, socks,
 | |
|                          ARES_GETSOCK_MAXNUM);
 | |
| 
 | |
|   for(i = 0; i < ARES_GETSOCK_MAXNUM; i++) {
 | |
|     pfd[i].events = 0;
 | |
|     pfd[i].revents = 0;
 | |
|     if(ARES_GETSOCK_READABLE(bitmask, i)) {
 | |
|       pfd[i].fd = socks[i];
 | |
|       pfd[i].events |= POLLRDNORM|POLLIN;
 | |
|     }
 | |
|     if(ARES_GETSOCK_WRITABLE(bitmask, i)) {
 | |
|       pfd[i].fd = socks[i];
 | |
|       pfd[i].events |= POLLWRNORM|POLLOUT;
 | |
|     }
 | |
|     if(pfd[i].events)
 | |
|       num++;
 | |
|     else
 | |
|       break;
 | |
|   }
 | |
| 
 | |
|   if(num)
 | |
|     nfds = Curl_poll(pfd, num, timeout_ms);
 | |
|   else
 | |
|     nfds = 0;
 | |
| 
 | |
|   if(!nfds)
 | |
|     /* Call ares_process() unconditionally here, even if we simply timed out
 | |
|        above, as otherwise the ares name resolve won't timeout! */
 | |
|     ares_process_fd((ares_channel)data->state.async.resolver, ARES_SOCKET_BAD,
 | |
|                     ARES_SOCKET_BAD);
 | |
|   else {
 | |
|     /* move through the descriptors and ask for processing on them */
 | |
|     for(i = 0; i < num; i++)
 | |
|       ares_process_fd((ares_channel)data->state.async.resolver,
 | |
|                       (pfd[i].revents & (POLLRDNORM|POLLIN))?
 | |
|                       pfd[i].fd:ARES_SOCKET_BAD,
 | |
|                       (pfd[i].revents & (POLLWRNORM|POLLOUT))?
 | |
|                       pfd[i].fd:ARES_SOCKET_BAD);
 | |
|   }
 | |
|   return nfds;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_is_resolved() is called repeatedly to check if a previous
 | |
|  * name resolve request has completed. It should also make sure to time-out if
 | |
|  * the operation seems to take too long.
 | |
|  *
 | |
|  * Returns normal CURLcode errors.
 | |
|  */
 | |
| CURLcode Curl_resolver_is_resolved(struct Curl_easy *data,
 | |
|                                    struct Curl_dns_entry **dns)
 | |
| {
 | |
|   struct thread_data *res = data->state.async.tdata;
 | |
|   CURLcode result = CURLE_OK;
 | |
| 
 | |
|   DEBUGASSERT(dns);
 | |
|   *dns = NULL;
 | |
| 
 | |
|   waitperform(data, 0);
 | |
| 
 | |
|   /* Now that we've checked for any last minute results above, see if there are
 | |
|      any responses still pending when the EXPIRE_HAPPY_EYEBALLS_DNS timer
 | |
|      expires. */
 | |
|   if(res
 | |
|      && res->num_pending
 | |
|      /* This is only set to non-zero if the timer was started. */
 | |
|      && (res->happy_eyeballs_dns_time.tv_sec
 | |
|          || res->happy_eyeballs_dns_time.tv_usec)
 | |
|      && (Curl_timediff(Curl_now(), res->happy_eyeballs_dns_time)
 | |
|          >= HAPPY_EYEBALLS_DNS_TIMEOUT)) {
 | |
|     /* Remember that the EXPIRE_HAPPY_EYEBALLS_DNS timer is no longer
 | |
|        running. */
 | |
|     memset(
 | |
|       &res->happy_eyeballs_dns_time, 0, sizeof(res->happy_eyeballs_dns_time));
 | |
| 
 | |
|     /* Cancel the raw c-ares request, which will fire query_completed_cb() with
 | |
|        ARES_ECANCELLED synchronously for all pending responses.  This will
 | |
|        leave us with res->num_pending == 0, which is perfect for the next
 | |
|        block. */
 | |
|     ares_cancel((ares_channel)data->state.async.resolver);
 | |
|     DEBUGASSERT(res->num_pending == 0);
 | |
|   }
 | |
| 
 | |
|   if(res && !res->num_pending) {
 | |
|     (void)Curl_addrinfo_callback(data, res->last_status, res->temp_ai);
 | |
|     /* temp_ai ownership is moved to the connection, so we need not free-up
 | |
|        them */
 | |
|     res->temp_ai = NULL;
 | |
| 
 | |
|     if(!data->state.async.dns)
 | |
|       result = Curl_resolver_error(data);
 | |
|     else
 | |
|       *dns = data->state.async.dns;
 | |
| 
 | |
|     destroy_async_data(&data->state.async);
 | |
|   }
 | |
| 
 | |
|   return result;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Curl_resolver_wait_resolv()
 | |
|  *
 | |
|  * Waits for a resolve to finish. This function should be avoided since using
 | |
|  * this risk getting the multi interface to "hang".
 | |
|  *
 | |
|  * 'entry' MUST be non-NULL.
 | |
|  *
 | |
|  * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved,
 | |
|  * CURLE_OPERATION_TIMEDOUT if a time-out occurred, or other errors.
 | |
|  */
 | |
| CURLcode Curl_resolver_wait_resolv(struct Curl_easy *data,
 | |
|                                    struct Curl_dns_entry **entry)
 | |
| {
 | |
|   CURLcode result = CURLE_OK;
 | |
|   timediff_t timeout;
 | |
|   struct curltime now = Curl_now();
 | |
| 
 | |
|   DEBUGASSERT(entry);
 | |
|   *entry = NULL; /* clear on entry */
 | |
| 
 | |
|   timeout = Curl_timeleft(data, &now, TRUE);
 | |
|   if(timeout < 0) {
 | |
|     /* already expired! */
 | |
|     connclose(data->conn, "Timed out before name resolve started");
 | |
|     return CURLE_OPERATION_TIMEDOUT;
 | |
|   }
 | |
|   if(!timeout)
 | |
|     timeout = CURL_TIMEOUT_RESOLVE * 1000; /* default name resolve timeout */
 | |
| 
 | |
|   /* Wait for the name resolve query to complete. */
 | |
|   while(!result) {
 | |
|     struct timeval *tvp, tv, store;
 | |
|     int itimeout;
 | |
|     timediff_t timeout_ms;
 | |
| 
 | |
| #if TIMEDIFF_T_MAX > INT_MAX
 | |
|     itimeout = (timeout > INT_MAX) ? INT_MAX : (int)timeout;
 | |
| #else
 | |
|     itimeout = (int)timeout;
 | |
| #endif
 | |
| 
 | |
|     store.tv_sec = itimeout/1000;
 | |
|     store.tv_usec = (itimeout%1000)*1000;
 | |
| 
 | |
|     tvp = ares_timeout((ares_channel)data->state.async.resolver, &store, &tv);
 | |
| 
 | |
|     /* use the timeout period ares returned to us above if less than one
 | |
|        second is left, otherwise just use 1000ms to make sure the progress
 | |
|        callback gets called frequent enough */
 | |
|     if(!tvp->tv_sec)
 | |
|       timeout_ms = (timediff_t)(tvp->tv_usec/1000);
 | |
|     else
 | |
|       timeout_ms = 1000;
 | |
| 
 | |
|     waitperform(data, timeout_ms);
 | |
|     result = Curl_resolver_is_resolved(data, entry);
 | |
| 
 | |
|     if(result || data->state.async.done)
 | |
|       break;
 | |
| 
 | |
|     if(Curl_pgrsUpdate(data))
 | |
|       result = CURLE_ABORTED_BY_CALLBACK;
 | |
|     else {
 | |
|       struct curltime now2 = Curl_now();
 | |
|       timediff_t timediff = Curl_timediff(now2, now); /* spent time */
 | |
|       if(timediff <= 0)
 | |
|         timeout -= 1; /* always deduct at least 1 */
 | |
|       else if(timediff > timeout)
 | |
|         timeout = -1;
 | |
|       else
 | |
|         timeout -= timediff;
 | |
|       now = now2; /* for next loop */
 | |
|     }
 | |
|     if(timeout < 0)
 | |
|       result = CURLE_OPERATION_TIMEDOUT;
 | |
|   }
 | |
|   if(result)
 | |
|     /* failure, so we cancel the ares operation */
 | |
|     ares_cancel((ares_channel)data->state.async.resolver);
 | |
| 
 | |
|   /* Operation complete, if the lookup was successful we now have the entry
 | |
|      in the cache. */
 | |
|   if(entry)
 | |
|     *entry = data->state.async.dns;
 | |
| 
 | |
|   if(result)
 | |
|     /* close the connection, since we can't return failure here without
 | |
|        cleaning up this connection properly. */
 | |
|     connclose(data->conn, "c-ares resolve failed");
 | |
| 
 | |
|   return result;
 | |
| }
 | |
| 
 | |
| #ifndef HAVE_CARES_GETADDRINFO
 | |
| 
 | |
| /* Connects results to the list */
 | |
| static void compound_results(struct thread_data *res,
 | |
|                              struct Curl_addrinfo *ai)
 | |
| {
 | |
|   if(!ai)
 | |
|     return;
 | |
| 
 | |
| #ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
 | |
|   if(res->temp_ai && res->temp_ai->ai_family == PF_INET6) {
 | |
|     /* We have results already, put the new IPv6 entries at the head of the
 | |
|        list. */
 | |
|     struct Curl_addrinfo *temp_ai_tail = res->temp_ai;
 | |
| 
 | |
|     while(temp_ai_tail->ai_next)
 | |
|       temp_ai_tail = temp_ai_tail->ai_next;
 | |
| 
 | |
|     temp_ai_tail->ai_next = ai;
 | |
|   }
 | |
|   else
 | |
| #endif /* CURLRES_IPV6 */
 | |
|   {
 | |
|     /* Add the new results to the list of old results. */
 | |
|     struct Curl_addrinfo *ai_tail = ai;
 | |
|     while(ai_tail->ai_next)
 | |
|       ai_tail = ai_tail->ai_next;
 | |
| 
 | |
|     ai_tail->ai_next = res->temp_ai;
 | |
|     res->temp_ai = ai;
 | |
|   }
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * ares_query_completed_cb() is the callback that ares will call when
 | |
|  * the host query initiated by ares_gethostbyname() from Curl_getaddrinfo(),
 | |
|  * when using ares, is completed either successfully or with failure.
 | |
|  */
 | |
| static void query_completed_cb(void *arg,  /* (struct connectdata *) */
 | |
|                                int status,
 | |
| #ifdef HAVE_CARES_CALLBACK_TIMEOUTS
 | |
|                                int timeouts,
 | |
| #endif
 | |
|                                struct hostent *hostent)
 | |
| {
 | |
|   struct Curl_easy *data = (struct Curl_easy *)arg;
 | |
|   struct thread_data *res;
 | |
| 
 | |
| #ifdef HAVE_CARES_CALLBACK_TIMEOUTS
 | |
|   (void)timeouts; /* ignored */
 | |
| #endif
 | |
| 
 | |
|   if(ARES_EDESTRUCTION == status)
 | |
|     /* when this ares handle is getting destroyed, the 'arg' pointer may not
 | |
|        be valid so only defer it when we know the 'status' says its fine! */
 | |
|     return;
 | |
| 
 | |
|   res = data->state.async.tdata;
 | |
|   if(res) {
 | |
|     res->num_pending--;
 | |
| 
 | |
|     if(CURL_ASYNC_SUCCESS == status) {
 | |
|       struct Curl_addrinfo *ai = Curl_he2ai(hostent, data->state.async.port);
 | |
|       if(ai) {
 | |
|         compound_results(res, ai);
 | |
|       }
 | |
|     }
 | |
|     /* A successful result overwrites any previous error */
 | |
|     if(res->last_status != ARES_SUCCESS)
 | |
|       res->last_status = status;
 | |
| 
 | |
|     /* If there are responses still pending, we presume they must be the
 | |
|        complementary IPv4 or IPv6 lookups that we started in parallel in
 | |
|        Curl_resolver_getaddrinfo() (for Happy Eyeballs).  If we've got a
 | |
|        "definitive" response from one of a set of parallel queries, we need to
 | |
|        think about how long we're willing to wait for more responses. */
 | |
|     if(res->num_pending
 | |
|        /* Only these c-ares status values count as "definitive" for these
 | |
|           purposes.  For example, ARES_ENODATA is what we expect when there is
 | |
|           no IPv6 entry for a domain name, and that's not a reason to get more
 | |
|           aggressive in our timeouts for the other response.  Other errors are
 | |
|           either a result of bad input (which should affect all parallel
 | |
|           requests), local or network conditions, non-definitive server
 | |
|           responses, or us cancelling the request. */
 | |
|        && (status == ARES_SUCCESS || status == ARES_ENOTFOUND)) {
 | |
|       /* Right now, there can only be up to two parallel queries, so don't
 | |
|          bother handling any other cases. */
 | |
|       DEBUGASSERT(res->num_pending == 1);
 | |
| 
 | |
|       /* It's possible that one of these parallel queries could succeed
 | |
|          quickly, but the other could always fail or timeout (when we're
 | |
|          talking to a pool of DNS servers that can only successfully resolve
 | |
|          IPv4 address, for example).
 | |
| 
 | |
|          It's also possible that the other request could always just take
 | |
|          longer because it needs more time or only the second DNS server can
 | |
|          fulfill it successfully.  But, to align with the philosophy of Happy
 | |
|          Eyeballs, we don't want to wait _too_ long or users will think
 | |
|          requests are slow when IPv6 lookups don't actually work (but IPv4 ones
 | |
|          do).
 | |
| 
 | |
|          So, now that we have a usable answer (some IPv4 addresses, some IPv6
 | |
|          addresses, or "no such domain"), we start a timeout for the remaining
 | |
|          pending responses.  Even though it is typical that this resolved
 | |
|          request came back quickly, that needn't be the case.  It might be that
 | |
|          this completing request didn't get a result from the first DNS server
 | |
|          or even the first round of the whole DNS server pool.  So it could
 | |
|          already be quite some time after we issued the DNS queries in the
 | |
|          first place.  Without modifying c-ares, we can't know exactly where in
 | |
|          its retry cycle we are.  We could guess based on how much time has
 | |
|          gone by, but it doesn't really matter.  Happy Eyeballs tells us that,
 | |
|          given usable information in hand, we simply don't want to wait "too
 | |
|          much longer" after we get a result.
 | |
| 
 | |
|          We simply wait an additional amount of time equal to the default
 | |
|          c-ares query timeout.  That is enough time for a typical parallel
 | |
|          response to arrive without being "too long".  Even on a network
 | |
|          where one of the two types of queries is failing or timing out
 | |
|          constantly, this will usually mean we wait a total of the default
 | |
|          c-ares timeout (5 seconds) plus the round trip time for the successful
 | |
|          request, which seems bearable.  The downside is that c-ares might race
 | |
|          with us to issue one more retry just before we give up, but it seems
 | |
|          better to "waste" that request instead of trying to guess the perfect
 | |
|          timeout to prevent it.  After all, we don't even know where in the
 | |
|          c-ares retry cycle each request is.
 | |
|       */
 | |
|       res->happy_eyeballs_dns_time = Curl_now();
 | |
|       Curl_expire(data, HAPPY_EYEBALLS_DNS_TIMEOUT,
 | |
|                   EXPIRE_HAPPY_EYEBALLS_DNS);
 | |
|     }
 | |
|   }
 | |
| }
 | |
| #else
 | |
| /* c-ares 1.16.0 or later */
 | |
| 
 | |
| /*
 | |
|  * ares2addr() converts an address list provided by c-ares to an internal
 | |
|  * libcurl compatible list
 | |
|  */
 | |
| static struct Curl_addrinfo *ares2addr(struct ares_addrinfo_node *node)
 | |
| {
 | |
|   /* traverse the ares_addrinfo_node list */
 | |
|   struct ares_addrinfo_node *ai;
 | |
|   struct Curl_addrinfo *cafirst = NULL;
 | |
|   struct Curl_addrinfo *calast = NULL;
 | |
|   int error = 0;
 | |
| 
 | |
|   for(ai = node; ai != NULL; ai = ai->ai_next) {
 | |
|     size_t ss_size;
 | |
|     struct Curl_addrinfo *ca;
 | |
|     /* ignore elements with unsupported address family, */
 | |
|     /* settle family-specific sockaddr structure size.  */
 | |
|     if(ai->ai_family == AF_INET)
 | |
|       ss_size = sizeof(struct sockaddr_in);
 | |
| #ifdef ENABLE_IPV6
 | |
|     else if(ai->ai_family == AF_INET6)
 | |
|       ss_size = sizeof(struct sockaddr_in6);
 | |
| #endif
 | |
|     else
 | |
|       continue;
 | |
| 
 | |
|     /* ignore elements without required address info */
 | |
|     if(!ai->ai_addr || !(ai->ai_addrlen > 0))
 | |
|       continue;
 | |
| 
 | |
|     /* ignore elements with bogus address size */
 | |
|     if((size_t)ai->ai_addrlen < ss_size)
 | |
|       continue;
 | |
| 
 | |
|     ca = malloc(sizeof(struct Curl_addrinfo) + ss_size);
 | |
|     if(!ca) {
 | |
|       error = EAI_MEMORY;
 | |
|       break;
 | |
|     }
 | |
| 
 | |
|     /* copy each structure member individually, member ordering, */
 | |
|     /* size, or padding might be different for each platform.    */
 | |
| 
 | |
|     ca->ai_flags     = ai->ai_flags;
 | |
|     ca->ai_family    = ai->ai_family;
 | |
|     ca->ai_socktype  = ai->ai_socktype;
 | |
|     ca->ai_protocol  = ai->ai_protocol;
 | |
|     ca->ai_addrlen   = (curl_socklen_t)ss_size;
 | |
|     ca->ai_addr      = NULL;
 | |
|     ca->ai_canonname = NULL;
 | |
|     ca->ai_next      = NULL;
 | |
| 
 | |
|     ca->ai_addr = (void *)((char *)ca + sizeof(struct Curl_addrinfo));
 | |
|     memcpy(ca->ai_addr, ai->ai_addr, ss_size);
 | |
| 
 | |
|     /* if the return list is empty, this becomes the first element */
 | |
|     if(!cafirst)
 | |
|       cafirst = ca;
 | |
| 
 | |
|     /* add this element last in the return list */
 | |
|     if(calast)
 | |
|       calast->ai_next = ca;
 | |
|     calast = ca;
 | |
|   }
 | |
| 
 | |
|   /* if we failed, destroy the Curl_addrinfo list */
 | |
|   if(error) {
 | |
|     Curl_freeaddrinfo(cafirst);
 | |
|     cafirst = NULL;
 | |
|   }
 | |
| 
 | |
|   return cafirst;
 | |
| }
 | |
| 
 | |
| static void addrinfo_cb(void *arg, int status, int timeouts,
 | |
|                         struct ares_addrinfo *result)
 | |
| {
 | |
|   struct Curl_easy *data = (struct Curl_easy *)arg;
 | |
|   struct thread_data *res = data->state.async.tdata;
 | |
|   (void)timeouts;
 | |
|   if(ARES_SUCCESS == status) {
 | |
|     res->temp_ai = ares2addr(result->nodes);
 | |
|     res->last_status = CURL_ASYNC_SUCCESS;
 | |
|     ares_freeaddrinfo(result);
 | |
|   }
 | |
|   res->num_pending--;
 | |
| }
 | |
| 
 | |
| #endif
 | |
| /*
 | |
|  * Curl_resolver_getaddrinfo() - when using ares
 | |
|  *
 | |
|  * Returns name information about the given hostname and port number. If
 | |
|  * successful, the 'hostent' is returned and the forth argument will point to
 | |
|  * memory we need to free after use. That memory *MUST* be freed with
 | |
|  * Curl_freeaddrinfo(), nothing else.
 | |
|  */
 | |
| struct Curl_addrinfo *Curl_resolver_getaddrinfo(struct Curl_easy *data,
 | |
|                                                 const char *hostname,
 | |
|                                                 int port,
 | |
|                                                 int *waitp)
 | |
| {
 | |
|   char *bufp;
 | |
| 
 | |
|   *waitp = 0; /* default to synchronous response */
 | |
| 
 | |
|   bufp = strdup(hostname);
 | |
|   if(bufp) {
 | |
|     struct thread_data *res = NULL;
 | |
|     free(data->state.async.hostname);
 | |
|     data->state.async.hostname = bufp;
 | |
|     data->state.async.port = port;
 | |
|     data->state.async.done = FALSE;   /* not done */
 | |
|     data->state.async.status = 0;     /* clear */
 | |
|     data->state.async.dns = NULL;     /* clear */
 | |
|     res = calloc(sizeof(struct thread_data), 1);
 | |
|     if(!res) {
 | |
|       free(data->state.async.hostname);
 | |
|       data->state.async.hostname = NULL;
 | |
|       return NULL;
 | |
|     }
 | |
|     data->state.async.tdata = res;
 | |
| 
 | |
|     /* initial status - failed */
 | |
|     res->last_status = ARES_ENOTFOUND;
 | |
| 
 | |
| #ifdef HAVE_CARES_GETADDRINFO
 | |
|     {
 | |
|       struct ares_addrinfo_hints hints;
 | |
|       char service[12];
 | |
|       int pf = PF_INET;
 | |
|       memset(&hints, 0, sizeof(hints));
 | |
| #ifdef CURLRES_IPV6
 | |
|       if(Curl_ipv6works(data))
 | |
|         /* The stack seems to be IPv6-enabled */
 | |
|         pf = PF_UNSPEC;
 | |
| #endif /* CURLRES_IPV6 */
 | |
|       hints.ai_family = pf;
 | |
|       hints.ai_socktype = (data->conn->transport == TRNSPRT_TCP)?
 | |
|         SOCK_STREAM : SOCK_DGRAM;
 | |
|       msnprintf(service, sizeof(service), "%d", port);
 | |
|       res->num_pending = 1;
 | |
|       ares_getaddrinfo((ares_channel)data->state.async.resolver, hostname,
 | |
|                        service, &hints, addrinfo_cb, data);
 | |
|     }
 | |
| #else
 | |
| 
 | |
| #ifdef HAVE_CARES_IPV6
 | |
|     if(Curl_ipv6works(data)) {
 | |
|       /* The stack seems to be IPv6-enabled */
 | |
|       res->num_pending = 2;
 | |
| 
 | |
|       /* areschannel is already setup in the Curl_open() function */
 | |
|       ares_gethostbyname((ares_channel)data->state.async.resolver, hostname,
 | |
|                           PF_INET, query_completed_cb, data);
 | |
|       ares_gethostbyname((ares_channel)data->state.async.resolver, hostname,
 | |
|                           PF_INET6, query_completed_cb, data);
 | |
|     }
 | |
|     else
 | |
| #endif
 | |
|     {
 | |
|       res->num_pending = 1;
 | |
| 
 | |
|       /* areschannel is already setup in the Curl_open() function */
 | |
|       ares_gethostbyname((ares_channel)data->state.async.resolver,
 | |
|                          hostname, PF_INET,
 | |
|                          query_completed_cb, data);
 | |
|     }
 | |
| #endif
 | |
|     *waitp = 1; /* expect asynchronous response */
 | |
|   }
 | |
|   return NULL; /* no struct yet */
 | |
| }
 | |
| 
 | |
| CURLcode Curl_set_dns_servers(struct Curl_easy *data,
 | |
|                               char *servers)
 | |
| {
 | |
|   CURLcode result = CURLE_NOT_BUILT_IN;
 | |
|   int ares_result;
 | |
| 
 | |
|   /* If server is NULL or empty, this would purge all DNS servers
 | |
|    * from ares library, which will cause any and all queries to fail.
 | |
|    * So, just return OK if none are configured and don't actually make
 | |
|    * any changes to c-ares.  This lets c-ares use it's defaults, which
 | |
|    * it gets from the OS (for instance from /etc/resolv.conf on Linux).
 | |
|    */
 | |
|   if(!(servers && servers[0]))
 | |
|     return CURLE_OK;
 | |
| 
 | |
| #ifdef HAVE_CARES_SERVERS_CSV
 | |
| #ifdef HAVE_CARES_PORTS_CSV
 | |
|   ares_result = ares_set_servers_ports_csv(data->state.async.resolver,
 | |
|                                            servers);
 | |
| #else
 | |
|   ares_result = ares_set_servers_csv(data->state.async.resolver, servers);
 | |
| #endif
 | |
|   switch(ares_result) {
 | |
|   case ARES_SUCCESS:
 | |
|     result = CURLE_OK;
 | |
|     break;
 | |
|   case ARES_ENOMEM:
 | |
|     result = CURLE_OUT_OF_MEMORY;
 | |
|     break;
 | |
|   case ARES_ENOTINITIALIZED:
 | |
|   case ARES_ENODATA:
 | |
|   case ARES_EBADSTR:
 | |
|   default:
 | |
|     result = CURLE_BAD_FUNCTION_ARGUMENT;
 | |
|     break;
 | |
|   }
 | |
| #else /* too old c-ares version! */
 | |
|   (void)data;
 | |
|   (void)(ares_result);
 | |
| #endif
 | |
|   return result;
 | |
| }
 | |
| 
 | |
| CURLcode Curl_set_dns_interface(struct Curl_easy *data,
 | |
|                                 const char *interf)
 | |
| {
 | |
| #ifdef HAVE_CARES_LOCAL_DEV
 | |
|   if(!interf)
 | |
|     interf = "";
 | |
| 
 | |
|   ares_set_local_dev((ares_channel)data->state.async.resolver, interf);
 | |
| 
 | |
|   return CURLE_OK;
 | |
| #else /* c-ares version too old! */
 | |
|   (void)data;
 | |
|   (void)interf;
 | |
|   return CURLE_NOT_BUILT_IN;
 | |
| #endif
 | |
| }
 | |
| 
 | |
| CURLcode Curl_set_dns_local_ip4(struct Curl_easy *data,
 | |
|                                 const char *local_ip4)
 | |
| {
 | |
| #ifdef HAVE_CARES_SET_LOCAL
 | |
|   struct in_addr a4;
 | |
| 
 | |
|   if((!local_ip4) || (local_ip4[0] == 0)) {
 | |
|     a4.s_addr = 0; /* disabled: do not bind to a specific address */
 | |
|   }
 | |
|   else {
 | |
|     if(Curl_inet_pton(AF_INET, local_ip4, &a4) != 1) {
 | |
|       return CURLE_BAD_FUNCTION_ARGUMENT;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   ares_set_local_ip4((ares_channel)data->state.async.resolver,
 | |
|                      ntohl(a4.s_addr));
 | |
| 
 | |
|   return CURLE_OK;
 | |
| #else /* c-ares version too old! */
 | |
|   (void)data;
 | |
|   (void)local_ip4;
 | |
|   return CURLE_NOT_BUILT_IN;
 | |
| #endif
 | |
| }
 | |
| 
 | |
| CURLcode Curl_set_dns_local_ip6(struct Curl_easy *data,
 | |
|                                 const char *local_ip6)
 | |
| {
 | |
| #if defined(HAVE_CARES_SET_LOCAL) && defined(ENABLE_IPV6)
 | |
|   unsigned char a6[INET6_ADDRSTRLEN];
 | |
| 
 | |
|   if((!local_ip6) || (local_ip6[0] == 0)) {
 | |
|     /* disabled: do not bind to a specific address */
 | |
|     memset(a6, 0, sizeof(a6));
 | |
|   }
 | |
|   else {
 | |
|     if(Curl_inet_pton(AF_INET6, local_ip6, a6) != 1) {
 | |
|       return CURLE_BAD_FUNCTION_ARGUMENT;
 | |
|     }
 | |
|   }
 | |
| 
 | |
|   ares_set_local_ip6((ares_channel)data->state.async.resolver, a6);
 | |
| 
 | |
|   return CURLE_OK;
 | |
| #else /* c-ares version too old! */
 | |
|   (void)data;
 | |
|   (void)local_ip6;
 | |
|   return CURLE_NOT_BUILT_IN;
 | |
| #endif
 | |
| }
 | |
| #endif /* CURLRES_ARES */
 |