Utilities/cmcurl/hostthre.c

   1 /***************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * Copyright (C) 1998 - 2006, Daniel Stenberg, <daniel@haxx.se>, et al.
   9  *
  10  * This software is licensed as described in the file COPYING, which
  11  * you should have received as part of this distribution. The terms
  12  * are also available at http://curl.haxx.se/docs/copyright.html.
  13  *
  14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15  * copies of the Software, and permit persons to whom the Software is
  16  * furnished to do so, under the terms of the COPYING file.
  17  *
  18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19  * KIND, either express or implied.
  20  *
  21  * $Id: hostthre.c,v 1.2 2007-03-15 19:22:13 andy Exp $
  22  ***************************************************************************/
  23
  24 #include "setup.h"
  25
  26 #include <string.h>
  27 #include <errno.h>
  28
  29 #ifdef NEED_MALLOC_H
  30 #include <malloc.h>
  31 #endif
  32 #ifdef HAVE_SYS_TYPES_H
  33 #include <sys/types.h>
  34 #endif
  35 #ifdef HAVE_SYS_SOCKET_H
  36 #include <sys/socket.h>
  37 #endif
  38 #ifdef HAVE_NETINET_IN_H
  39 #include <netinet/in.h>
  40 #endif
  41 #ifdef HAVE_NETDB_H
  42 #include <netdb.h>
  43 #endif
  44 #ifdef HAVE_ARPA_INET_H
  45 #include <arpa/inet.h>
  46 #endif
  47 #ifdef HAVE_STDLIB_H
  48 #include <stdlib.h>     /* required for free() prototypes */
  49 #endif
  50 #ifdef HAVE_UNISTD_H
  51 #include <unistd.h>     /* for the close() proto */
  52 #endif
  53 #ifdef  VMS
  54 #include <in.h>
  55 #include <inet.h>
  56 #include <stdlib.h>
  57 #endif
  58
  59 #ifdef HAVE_SETJMP_H
  60 #include <setjmp.h>
  61 #endif
  62
  63 #ifdef HAVE_PROCESS_H
  64 #include <process.h>
  65 #endif
  66
  67 #if (defined(NETWARE) && defined(__NOVELL_LIBC__))
  68 #undef in_addr_t
  69 #define in_addr_t unsigned long
  70 #endif
  71
  72 #include "urldata.h"
  73 #include "sendf.h"
  74 #include "hostip.h"
  75 #include "hash.h"
  76 #include "share.h"
  77 #include "strerror.h"
  78 #include "url.h"
  79 #include "multiif.h"
  80
  81 #define _MPRINTF_REPLACE /* use our functions only */
  82 #include <curl/mprintf.h>
  83
  84 #include "inet_ntop.h"
  85
  86 #include "memory.h"
  87 /* The last #include file should be: */
  88 #include "memdebug.h"
  89
  90 #if defined(_MSC_VER) && defined(CURL_NO__BEGINTHREADEX)
  91 #pragma message ("No _beginthreadex() available in this RTL")
  92 #endif
  93
  94 /***********************************************************************
  95  * Only for Windows threaded name resolves builds
  96  **********************************************************************/
  97 #ifdef CURLRES_THREADED
  98
  99 /* This function is used to init a threaded resolve */
 100 static bool init_resolve_thread(struct connectdata *conn,
 101                                 const char *hostname, int port,
 102                                 const Curl_addrinfo *hints);
 103
 104 #ifdef CURLRES_IPV4
 105   #define THREAD_FUNC  gethostbyname_thread
 106   #define THREAD_NAME "gethostbyname_thread"
 107 #else
 108   #define THREAD_FUNC  getaddrinfo_thread
 109   #define THREAD_NAME "getaddrinfo_thread"
 110 #endif
 111
 112 #if defined(DEBUG_THREADING_GETHOSTBYNAME) || \
 113     defined(DEBUG_THREADING_GETADDRINFO)
 114 /* If this is defined, provide tracing */
 115 #define TRACE(args)  \
 116  do { trace_it("%u: ", __LINE__); trace_it args; } while (0)
 117
 118 static void trace_it (const char *fmt, ...)
 119 {
 120   static int do_trace = -1;
 121   va_list args;
 122
 123   if (do_trace == -1) {
 124     const char *env = getenv("CURL_TRACE");
 125     do_trace = (env && atoi(env) > 0);
 126   }
 127   if (!do_trace)
 128     return;
 129   va_start (args, fmt);
 130   vfprintf (stderr, fmt, args);
 131   fflush (stderr);
 132   va_end (args);
 133 }
 134 #else
 135 #define TRACE(x)
 136 #endif
 137
 138 #ifdef DEBUG_THREADING_GETADDRINFO
 139 static void dump_addrinfo (struct connectdata *conn, const struct addrinfo *ai)
 140 {
 141   TRACE(("dump_addrinfo:\n"));
 142   for ( ; ai; ai = ai->ai_next) {
 143     char  buf [INET6_ADDRSTRLEN];
 144
 145     trace_it("    fam %2d, CNAME %s, ",
 146              ai->ai_family, ai->ai_canonname ? ai->ai_canonname : "<none>");
 147     if (Curl_printable_address(ai, buf, sizeof(buf)))
 148       trace_it("%s\n", buf);
 149     else
 150       trace_it("failed; %s\n", Curl_strerror(conn,WSAGetLastError()));
 151   }
 152 }
 153 #endif
 154
 155 struct thread_data {
 156   HANDLE thread_hnd;
 157   unsigned thread_id;
 158   DWORD  thread_status;
 159   curl_socket_t dummy_sock;   /* dummy for Curl_resolv_fdset() */
 160   HANDLE mutex_waiting;  /* marks that we are still waiting for a resolve */
 161   HANDLE event_resolved; /* marks that the thread obtained the information */
 162   HANDLE event_thread_started; /* marks that the thread has initialized and
 163                                   started */
 164   HANDLE mutex_terminate; /* serializes access to flag_terminate */
 165   HANDLE event_terminate; /* flag for thread to terminate instead of calling
 166                              callbacks */
 167 #ifdef CURLRES_IPV6
 168   struct addrinfo hints;
 169 #endif
 170 };
 171
 172 /* Data for synchronization between resolver thread and its parent */
 173 struct thread_sync_data {
 174   HANDLE mutex_waiting;   /* thread_data.mutex_waiting duplicate */
 175   HANDLE mutex_terminate; /* thread_data.mutex_terminate duplicate */
 176   HANDLE event_terminate; /* thread_data.event_terminate duplicate */
 177   char * hostname;        /* hostname to resolve, Curl_async.hostname
 178                              duplicate */
 179 };
 180
 181 /* Destroy resolver thread synchronization data */
 182 static
 183 void destroy_thread_sync_data(struct thread_sync_data * tsd)
 184 {
 185   if (tsd->hostname) {
 186     free(tsd->hostname);
 187     tsd->hostname = NULL;
 188   }
 189   if (tsd->event_terminate) {
 190     CloseHandle(tsd->event_terminate);
 191     tsd->event_terminate = NULL;
 192   }
 193   if (tsd->mutex_terminate) {
 194     CloseHandle(tsd->mutex_terminate);
 195     tsd->mutex_terminate = NULL;
 196   }
 197   if (tsd->mutex_waiting) {
 198     CloseHandle(tsd->mutex_waiting);
 199     tsd->mutex_waiting = NULL;
 200   }
 201 }
 202
 203 /* Initialize resolver thread synchronization data */
 204 static
 205 BOOL init_thread_sync_data(struct thread_data * td,
 206                            char * hostname,
 207                            struct thread_sync_data * tsd)
 208 {
 209   HANDLE curr_proc = GetCurrentProcess();
 210
 211   memset(tsd, 0, sizeof(*tsd));
 212   if (!DuplicateHandle(curr_proc, td->mutex_waiting,
 213                        curr_proc, &tsd->mutex_waiting, 0, FALSE,
 214                        DUPLICATE_SAME_ACCESS)) {
 215     /* failed to duplicate the mutex, no point in continuing */
 216     destroy_thread_sync_data(tsd);
 217     return FALSE;
 218   }
 219   if (!DuplicateHandle(curr_proc, td->mutex_terminate,
 220                        curr_proc, &tsd->mutex_terminate, 0, FALSE,
 221                        DUPLICATE_SAME_ACCESS)) {
 222     /* failed to duplicate the mutex, no point in continuing */
 223     destroy_thread_sync_data(tsd);
 224     return FALSE;
 225   }
 226   if (!DuplicateHandle(curr_proc, td->event_terminate,
 227                        curr_proc, &tsd->event_terminate, 0, FALSE,
 228                        DUPLICATE_SAME_ACCESS)) {
 229     /* failed to duplicate the event, no point in continuing */
 230     destroy_thread_sync_data(tsd);
 231     return FALSE;
 232   }
 233   /* Copying hostname string because original can be destroyed by parent
 234    * thread during gethostbyname execution.
 235    */
 236   tsd->hostname = strdup(hostname);
 237   if (!tsd->hostname) {
 238     /* Memory allocation failed */
 239     destroy_thread_sync_data(tsd);
 240     return FALSE;
 241   }
 242   return TRUE;
 243 }
 244
 245 /* acquire resolver thread synchronization */
 246 static
 247 BOOL acquire_thread_sync(struct thread_sync_data * tsd)
 248 {
 249   /* is the thread initiator still waiting for us ? */
 250   if (WaitForSingleObject(tsd->mutex_waiting, 0) == WAIT_TIMEOUT) {
 251     /* yes, it is */
 252
 253     /* Waiting access to event_terminate */
 254     if (WaitForSingleObject(tsd->mutex_terminate, INFINITE) != WAIT_OBJECT_0) {
 255       /* Something went wrong - now just ignoring */
 256     }
 257     else {
 258       if (WaitForSingleObject(tsd->event_terminate, 0) != WAIT_TIMEOUT) {
 259         /* Parent thread signaled us to terminate.
 260          * This means that all data in conn->async is now destroyed
 261          * and we cannot use it.
 262          */
 263       }
 264       else {
 265         return TRUE;
 266       }
 267     }
 268   }
 269   return FALSE;
 270 }
 271
 272 /* release resolver thread synchronization */
 273 static
 274 void release_thread_sync(struct thread_sync_data * tsd)
 275 {
 276   ReleaseMutex(tsd->mutex_terminate);
 277 }
 278
 279 #if defined(CURLRES_IPV4)
 280 /*
 281  * gethostbyname_thread() resolves a name, calls the Curl_addrinfo4_callback
 282  * and then exits.
 283  *
 284  * For builds without ARES/ENABLE_IPV6, create a resolver thread and wait on
 285  * it.
 286  */
 287 static unsigned __stdcall gethostbyname_thread (void *arg)
 288 {
 289   struct connectdata *conn = (struct connectdata*) arg;
 290   struct thread_data *td = (struct thread_data*) conn->async.os_specific;
 291   struct hostent *he;
 292   int    rc = 0;
 293
 294   /* Duplicate the passed mutex and event handles.
 295    * This allows us to use it even after the container gets destroyed
 296    * due to a resolver timeout.
 297    */
 298   struct thread_sync_data tsd = { 0,0,0,NULL };
 299   if (!init_thread_sync_data(td, conn->async.hostname, &tsd)) {
 300     /* thread synchronization data initialization failed */
 301     return (unsigned)-1;
 302   }
 303
 304   WSASetLastError (conn->async.status = NO_DATA); /* pending status */
 305
 306   /* Signaling that we have initialized all copies of data and handles we
 307      need */
 308   SetEvent(td->event_thread_started);
 309
 310   he = gethostbyname (tsd.hostname);
 311
 312   /* is parent thread waiting for us and are we able to access conn members? */
 313   if (acquire_thread_sync(&tsd)) {
 314     /* Mark that we have obtained the information, and that we are calling
 315      * back with it. */
 316     SetEvent(td->event_resolved);
 317     if (he) {
 318       rc = Curl_addrinfo4_callback(conn, CURL_ASYNC_SUCCESS, he);
 319     }
 320     else {
 321       rc = Curl_addrinfo4_callback(conn, (int)WSAGetLastError(), NULL);
 322     }
 323     TRACE(("Winsock-error %d, addr %s\n", conn->async.status,
 324            he ? inet_ntoa(*(struct in_addr*)he->h_addr) : "unknown"));
 325     release_thread_sync(&tsd);
 326   }
 327
 328   /* clean up */
 329   destroy_thread_sync_data(&tsd);
 330
 331   return (rc);
 332   /* An implicit _endthreadex() here */
 333 }
 334
 335 #elif defined(CURLRES_IPV6)
 336
 337 /*
 338  * getaddrinfo_thread() resolves a name, calls Curl_addrinfo6_callback and then
 339  * exits.
 340  *
 341  * For builds without ARES, but with ENABLE_IPV6, create a resolver thread
 342  * and wait on it.
 343  */
 344 static unsigned __stdcall getaddrinfo_thread (void *arg)
 345 {
 346   struct connectdata *conn = (struct connectdata*) arg;
 347   struct thread_data *td   = (struct thread_data*) conn->async.os_specific;
 348   struct addrinfo    *res;
 349   char   service [NI_MAXSERV];
 350   int    rc;
 351   struct addrinfo hints = td->hints;
 352
 353   /* Duplicate the passed mutex handle.
 354    * This allows us to use it even after the container gets destroyed
 355    * due to a resolver timeout.
 356    */
 357   struct thread_sync_data tsd = { 0,0,0,NULL };
 358   if (!init_thread_sync_data(td, conn->async.hostname, &tsd)) {
 359     /* thread synchronization data initialization failed */
 360     return -1;
 361   }
 362
 363   itoa(conn->async.port, service, 10);
 364
 365   WSASetLastError(conn->async.status = NO_DATA); /* pending status */
 366
 367   /* Signaling that we have initialized all copies of data and handles we
 368      need */
 369   SetEvent(td->event_thread_started);
 370
 371   rc = getaddrinfo(tsd.hostname, service, &hints, &res);
 372
 373   /* is parent thread waiting for us and are we able to access conn members? */
 374   if (acquire_thread_sync(&tsd)) {
 375     /* Mark that we have obtained the information, and that we are calling
 376        back with it. */
 377     SetEvent(td->event_resolved);
 378
 379     if (rc == 0) {
 380 #ifdef DEBUG_THREADING_GETADDRINFO
 381       dump_addrinfo (conn, res);
 382 #endif
 383       rc = Curl_addrinfo6_callback(conn, CURL_ASYNC_SUCCESS, res);
 384     }
 385     else {
 386       rc = Curl_addrinfo6_callback(conn, (int)WSAGetLastError(), NULL);
 387       TRACE(("Winsock-error %d, no address\n", conn->async.status));
 388     }
 389     release_thread_sync(&tsd);
 390   }
 391
 392   /* clean up */
 393   destroy_thread_sync_data(&tsd);
 394
 395   return (rc);
 396   /* An implicit _endthreadex() here */
 397 }
 398 #endif
 399
 400 /*
 401  * Curl_destroy_thread_data() cleans up async resolver data and thread handle.
 402  * Complementary of ares_destroy.
 403  */
 404 void Curl_destroy_thread_data (struct Curl_async *async)
 405 {
 406   if (async->hostname)
 407     free(async->hostname);
 408
 409   if (async->os_specific) {
 410     struct thread_data *td = (struct thread_data*) async->os_specific;
 411     curl_socket_t sock = td->dummy_sock;
 412
 413     if (td->mutex_terminate && td->event_terminate) {
 414       /* Signaling resolver thread to terminate */
 415       if (WaitForSingleObject(td->mutex_terminate, INFINITE) == WAIT_OBJECT_0) {
 416         SetEvent(td->event_terminate);
 417         ReleaseMutex(td->mutex_terminate);
 418       }
 419       else {
 420         /* Something went wrong - just ignoring it */
 421       }
 422     }
 423
 424     if (td->mutex_terminate)
 425       CloseHandle(td->mutex_terminate);
 426     if (td->event_terminate)
 427       CloseHandle(td->event_terminate);
 428     if (td->event_thread_started)
 429       CloseHandle(td->event_thread_started);
 430
 431     if (sock != CURL_SOCKET_BAD)
 432       sclose(sock);
 433
 434     /* destroy the synchronization objects */
 435     if (td->mutex_waiting)
 436       CloseHandle(td->mutex_waiting);
 437     td->mutex_waiting = NULL;
 438     if (td->event_resolved)
 439       CloseHandle(td->event_resolved);
 440
 441     if (td->thread_hnd)
 442       CloseHandle(td->thread_hnd);
 443
 444     free(async->os_specific);
 445   }
 446   async->hostname = NULL;
 447   async->os_specific = NULL;
 448 }
 449
 450 /*
 451  * init_resolve_thread() starts a new thread that performs the actual
 452  * resolve. This function returns before the resolve is done.
 453  *
 454  * Returns FALSE in case of failure, otherwise TRUE.
 455  */
 456 static bool init_resolve_thread (struct connectdata *conn,
 457                                  const char *hostname, int port,
 458                                  const Curl_addrinfo *hints)
 459 {
 460   struct thread_data *td = calloc(sizeof(*td), 1);
 461   HANDLE thread_and_event[2] = {0};
 462
 463   if (!td) {
 464     SetLastError(ENOMEM);
 465     return FALSE;
 466   }
 467
 468   Curl_safefree(conn->async.hostname);
 469   conn->async.hostname = strdup(hostname);
 470   if (!conn->async.hostname) {
 471     free(td);
 472     SetLastError(ENOMEM);
 473     return FALSE;
 474   }
 475
 476   conn->async.port = port;
 477   conn->async.done = FALSE;
 478   conn->async.status = 0;
 479   conn->async.dns = NULL;
 480   conn->async.os_specific = (void*) td;
 481   td->dummy_sock = CURL_SOCKET_BAD;
 482
 483   /* Create the mutex used to inform the resolver thread that we're
 484    * still waiting, and take initial ownership.
 485    */
 486   td->mutex_waiting = CreateMutex(NULL, TRUE, NULL);
 487   if (td->mutex_waiting == NULL) {
 488     Curl_destroy_thread_data(&conn->async);
 489     SetLastError(EAGAIN);
 490     return FALSE;
 491   }
 492
 493   /* Create the event that the thread uses to inform us that it's
 494    * done resolving. Do not signal it.
 495    */
 496   td->event_resolved = CreateEvent(NULL, TRUE, FALSE, NULL);
 497   if (td->event_resolved == NULL) {
 498     Curl_destroy_thread_data(&conn->async);
 499     SetLastError(EAGAIN);
 500     return FALSE;
 501   }
 502   /* Create the mutex used to serialize access to event_terminated
 503    * between us and resolver thread.
 504    */
 505   td->mutex_terminate = CreateMutex(NULL, FALSE, NULL);
 506   if (td->mutex_terminate == NULL) {
 507     Curl_destroy_thread_data(&conn->async);
 508     SetLastError(EAGAIN);
 509     return FALSE;
 510   }
 511   /* Create the event used to signal thread that it should terminate.
 512    */
 513   td->event_terminate = CreateEvent(NULL, TRUE, FALSE, NULL);
 514   if (td->event_terminate == NULL) {
 515     Curl_destroy_thread_data(&conn->async);
 516     SetLastError(EAGAIN);
 517     return FALSE;
 518   }
 519   /* Create the event used by thread to inform it has initialized its own data.
 520    */
 521   td->event_thread_started = CreateEvent(NULL, TRUE, FALSE, NULL);
 522   if (td->event_thread_started == NULL) {
 523     Curl_destroy_thread_data(&conn->async);
 524     SetLastError(EAGAIN);
 525     return FALSE;
 526   }
 527
 528 #ifdef _WIN32_WCE
 529   td->thread_hnd = (HANDLE) CreateThread(NULL, 0,
 530                                          (LPTHREAD_START_ROUTINE) THREAD_FUNC,
 531                                          conn, 0, &td->thread_id);
 532 #else
 533   td->thread_hnd = (HANDLE) _beginthreadex(NULL, 0, THREAD_FUNC,
 534                                            conn, 0, &td->thread_id);
 535 #endif
 536
 537 #ifdef CURLRES_IPV6
 538   curlassert(hints);
 539   td->hints = *hints;
 540 #else
 541   (void) hints;
 542 #endif
 543
 544   if (!td->thread_hnd) {
 545 #ifdef _WIN32_WCE
 546      TRACE(("CreateThread() failed; %s\n", Curl_strerror(conn,GetLastError())));
 547 #else
 548      SetLastError(errno);
 549      TRACE(("_beginthreadex() failed; %s\n", Curl_strerror(conn,errno)));
 550 #endif
 551      Curl_destroy_thread_data(&conn->async);
 552      return FALSE;
 553   }
 554   /* Waiting until the thread will initialize its data or it will exit due errors.
 555    */
 556   thread_and_event[0] = td->thread_hnd;
 557   thread_and_event[1] = td->event_thread_started;
 558   if (WaitForMultipleObjects(sizeof(thread_and_event) /
 559                              sizeof(thread_and_event[0]),
 560                              (const HANDLE*)thread_and_event, FALSE,
 561                              INFINITE) == WAIT_FAILED) {
 562     /* The resolver thread has been created,
 563      * most probably it works now - ignoring this "minor" error
 564      */
 565   }
 566   /* This socket is only to keep Curl_resolv_fdset() and select() happy;
 567    * should never become signalled for read/write since it's unbound but
 568    * Windows needs atleast 1 socket in select().
 569    */
 570   td->dummy_sock = socket(AF_INET, SOCK_DGRAM, 0);
 571   return TRUE;
 572 }
 573
 574
 575 /*
 576  * Curl_wait_for_resolv() waits for a resolve to finish. This function should
 577  * be avoided since using this risk getting the multi interface to "hang".
 578  *
 579  * If 'entry' is non-NULL, make it point to the resolved dns entry
 580  *
 581  * This is the version for resolves-in-a-thread.
 582  */
 583 CURLcode Curl_wait_for_resolv(struct connectdata *conn,
 584                               struct Curl_dns_entry **entry)
 585 {
 586   struct thread_data   *td = (struct thread_data*) conn->async.os_specific;
 587   struct SessionHandle *data = conn->data;
 588   long   timeout;
 589   DWORD  status, ticks;
 590   CURLcode rc;
 591
 592   curlassert (conn && td);
 593
 594   /* now, see if there's a connect timeout or a regular timeout to
 595      use instead of the default one */
 596   timeout =
 597     conn->data->set.connecttimeout ? conn->data->set.connecttimeout :
 598     conn->data->set.timeout ? conn->data->set.timeout :
 599     CURL_TIMEOUT_RESOLVE; /* default name resolve timeout */
 600   ticks = GetTickCount();
 601
 602   /* wait for the thread to resolve the name */
 603   status = WaitForSingleObject(td->event_resolved, 1000UL*timeout);
 604
 605   /* mark that we are now done waiting */
 606   ReleaseMutex(td->mutex_waiting);
 607
 608   /* close our handle to the mutex, no point in hanging on to it */
 609   CloseHandle(td->mutex_waiting);
 610   td->mutex_waiting = NULL;
 611
 612   /* close the event handle, it's useless now */
 613   CloseHandle(td->event_resolved);
 614   td->event_resolved = NULL;
 615
 616   /* has the resolver thread succeeded in resolving our query ? */
 617   if (status == WAIT_OBJECT_0) {
 618     /* wait for the thread to exit, it's in the callback sequence */
 619     if (WaitForSingleObject(td->thread_hnd, 5000) == WAIT_TIMEOUT) {
 620       TerminateThread(td->thread_hnd, 0);
 621       conn->async.done = TRUE;
 622       td->thread_status = (DWORD)-1;
 623       TRACE(("%s() thread stuck?!, ", THREAD_NAME));
 624     }
 625     else {
 626       /* Thread finished before timeout; propagate Winsock error to this
 627        * thread.  'conn->async.done = TRUE' is set in
 628        * Curl_addrinfo4/6_callback().
 629        */
 630       WSASetLastError(conn->async.status);
 631       GetExitCodeThread(td->thread_hnd, &td->thread_status);
 632       TRACE(("%s() status %lu, thread retval %lu, ",
 633              THREAD_NAME, status, td->thread_status));
 634     }
 635   }
 636   else {
 637     conn->async.done = TRUE;
 638     td->thread_status = (DWORD)-1;
 639     TRACE(("%s() timeout, ", THREAD_NAME));
 640   }
 641
 642   TRACE(("elapsed %lu ms\n", GetTickCount()-ticks));
 643
 644   if(entry)
 645     *entry = conn->async.dns;
 646
 647   rc = CURLE_OK;
 648
 649   if (!conn->async.dns) {
 650     /* a name was not resolved */
 651     if (td->thread_status == CURLE_OUT_OF_MEMORY) {
 652       rc = CURLE_OUT_OF_MEMORY;
 653       failf(data, "Could not resolve host: %s", curl_easy_strerror(rc));
 654     }
 655     else if(conn->async.done) {
 656       if(conn->bits.httpproxy) {
 657         failf(data, "Could not resolve proxy: %s; %s",
 658               conn->proxy.dispname, Curl_strerror(conn, conn->async.status));
 659         rc = CURLE_COULDNT_RESOLVE_PROXY;
 660       }
 661       else {
 662         failf(data, "Could not resolve host: %s; %s",
 663               conn->host.name, Curl_strerror(conn, conn->async.status));
 664         rc = CURLE_COULDNT_RESOLVE_HOST;
 665       }
 666     }
 667     else if (td->thread_status == (DWORD)-1 || conn->async.status == NO_DATA) {
 668       failf(data, "Resolving host timed out: %s", conn->host.name);
 669       rc = CURLE_OPERATION_TIMEDOUT;
 670     }
 671     else
 672       rc = CURLE_OPERATION_TIMEDOUT;
 673   }
 674
 675   Curl_destroy_thread_data(&conn->async);
 676
 677   if(!conn->async.dns)
 678     conn->bits.close = TRUE;
 679
 680   return (rc);
 681 }
 682
 683 /*
 684  * Curl_is_resolved() is called repeatedly to check if a previous name resolve
 685  * request has completed. It should also make sure to time-out if the
 686  * operation seems to take too long.
 687  */
 688 CURLcode Curl_is_resolved(struct connectdata *conn,
 689                           struct Curl_dns_entry **entry)
 690 {
 691   *entry = NULL;
 692
 693   if (conn->async.done) {
 694     /* we're done */
 695     Curl_destroy_thread_data(&conn->async);
 696     if (!conn->async.dns) {
 697       TRACE(("Curl_is_resolved(): CURLE_COULDNT_RESOLVE_HOST\n"));
 698       return CURLE_COULDNT_RESOLVE_HOST;
 699     }
 700     *entry = conn->async.dns;
 701     TRACE(("resolved okay, dns %p\n", *entry));
 702   }
 703   return CURLE_OK;
 704 }
 705
 706 int Curl_resolv_getsock(struct connectdata *conn,
 707                         curl_socket_t *socks,
 708                         int numsocks)
 709 {
 710   const struct thread_data *td =
 711     (const struct thread_data *) conn->async.os_specific;
 712
 713   if (td && td->dummy_sock != CURL_SOCKET_BAD) {
 714     if(numsocks) {
 715       /* return one socket waiting for writable, even though this is just
 716          a dummy */
 717       socks[0] = td->dummy_sock;
 718       return GETSOCK_WRITESOCK(0);
 719     }
 720   }
 721   return 0;
 722 }
 723
 724 #ifdef CURLRES_IPV4
 725 /*
 726  * Curl_getaddrinfo() - for Windows threading without ENABLE_IPV6.
 727  */
 728 Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
 729                                 const char *hostname,
 730                                 int port,
 731                                 int *waitp)
 732 {
 733   struct hostent *h = NULL;
 734   struct SessionHandle *data = conn->data;
 735   in_addr_t in;
 736
 737   *waitp = 0; /* don't wait, we act synchronously */
 738
 739   in = inet_addr(hostname);
 740   if (in != CURL_INADDR_NONE)
 741     /* This is a dotted IP address 123.123.123.123-style */
 742     return Curl_ip2addr(in, hostname, port);
 743
 744   /* fire up a new resolver thread! */
 745   if (init_resolve_thread(conn, hostname, port, NULL)) {
 746     *waitp = TRUE;  /* please wait for the response */
 747     return NULL;
 748   }
 749
 750   /* fall-back to blocking version */
 751   infof(data, "init_resolve_thread() failed for %s; %s\n",
 752         hostname, Curl_strerror(conn,GetLastError()));
 753
 754   h = gethostbyname(hostname);
 755   if (!h) {
 756     infof(data, "gethostbyname(2) failed for %s:%d; %s\n",
 757           hostname, port, Curl_strerror(conn,WSAGetLastError()));
 758     return NULL;
 759   }
 760   return Curl_he2ai(h, port);
 761 }
 762 #endif /* CURLRES_IPV4 */
 763
 764 #ifdef CURLRES_IPV6
 765 /*
 766  * Curl_getaddrinfo() - for Windows threading IPv6 enabled
 767  */
 768 Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
 769                                 const char *hostname,
 770                                 int port,
 771                                 int *waitp)
 772 {
 773   struct addrinfo hints, *res;
 774   int error;
 775   char sbuf[NI_MAXSERV];
 776   curl_socket_t s;
 777   int pf;
 778   struct SessionHandle *data = conn->data;
 779
 780   *waitp = FALSE; /* default to synch response */
 781
 782   /* see if we have an IPv6 stack */
 783   s = socket(PF_INET6, SOCK_DGRAM, 0);
 784   if (s == CURL_SOCKET_BAD) {
 785     /* Some non-IPv6 stacks have been found to make very slow name resolves
 786      * when PF_UNSPEC is used, so thus we switch to a mere PF_INET lookup if
 787      * the stack seems to be a non-ipv6 one. */
 788
 789     pf = PF_INET;
 790   }
 791   else {
 792     /* This seems to be an IPv6-capable stack, use PF_UNSPEC for the widest
 793      * possible checks. And close the socket again.
 794      */
 795     sclose(s);
 796
 797     /*
 798      * Check if a more limited name resolve has been requested.
 799      */
 800     switch(data->set.ip_version) {
 801     case CURL_IPRESOLVE_V4:
 802       pf = PF_INET;
 803       break;
 804     case CURL_IPRESOLVE_V6:
 805       pf = PF_INET6;
 806       break;
 807     default:
 808       pf = PF_UNSPEC;
 809       break;
 810     }
 811   }
 812
 813   memset(&hints, 0, sizeof(hints));
 814   hints.ai_family = pf;
 815   hints.ai_socktype = conn->socktype;
 816 #if 0 /* removed nov 8 2005 before 7.15.1 */
 817   hints.ai_flags = AI_CANONNAME;
 818 #endif
 819   itoa(port, sbuf, 10);
 820
 821   /* fire up a new resolver thread! */
 822   if (init_resolve_thread(conn, hostname, port, &hints)) {
 823     *waitp = TRUE;  /* please wait for the response */
 824     return NULL;
 825   }
 826
 827   /* fall-back to blocking version */
 828   infof(data, "init_resolve_thread() failed for %s; %s\n",
 829         hostname, Curl_strerror(conn,GetLastError()));
 830
 831   error = getaddrinfo(hostname, sbuf, &hints, &res);
 832   if (error) {
 833     infof(data, "getaddrinfo() failed for %s:%d; %s\n",
 834           hostname, port, Curl_strerror(conn,WSAGetLastError()));
 835     return NULL;
 836   }
 837   return res;
 838 }
 839 #endif /* CURLRES_IPV6 */
 840 #endif /* CURLRES_THREADED */