1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2011, 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 ***************************************************************************/ 22 23#include "setup.h" 24 25#include <string.h> 26 27#ifdef HAVE_SYS_SOCKET_H 28#include <sys/socket.h> 29#endif 30#ifdef HAVE_NETINET_IN_H 31#include <netinet/in.h> 32#endif 33#ifdef HAVE_NETDB_H 34#include <netdb.h> 35#endif 36#ifdef HAVE_ARPA_INET_H 37#include <arpa/inet.h> 38#endif 39#ifdef HAVE_STDLIB_H 40#include <stdlib.h> /* required for free() prototypes */ 41#endif 42#ifdef HAVE_UNISTD_H 43#include <unistd.h> /* for the close() proto */ 44#endif 45#ifdef __VMS 46#include <in.h> 47#include <inet.h> 48#include <stdlib.h> 49#endif 50 51#ifdef HAVE_SETJMP_H 52#include <setjmp.h> 53#endif 54#ifdef HAVE_SIGNAL_H 55#include <signal.h> 56#endif 57 58#ifdef HAVE_PROCESS_H 59#include <process.h> 60#endif 61 62#include "urldata.h" 63#include "sendf.h" 64#include "hostip.h" 65#include "hash.h" 66#include "share.h" 67#include "strerror.h" 68#include "url.h" 69#include "inet_ntop.h" 70#include "warnless.h" 71 72#define _MPRINTF_REPLACE /* use our functions only */ 73#include <curl/mprintf.h> 74 75#include "curl_memory.h" 76/* The last #include file should be: */ 77#include "memdebug.h" 78 79#if defined(CURLRES_SYNCH) && \ 80 defined(HAVE_ALARM) && defined(SIGALRM) && defined(HAVE_SIGSETJMP) 81/* alarm-based timeouts can only be used with all the dependencies satisfied */ 82#define USE_ALARM_TIMEOUT 83#endif 84 85/* 86 * hostip.c explained 87 * ================== 88 * 89 * The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c 90 * source file are these: 91 * 92 * CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use 93 * that. The host may not be able to resolve IPv6, but we don't really have to 94 * take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4 95 * defined. 96 * 97 * CURLRES_ARES - is defined if libcurl is built to use c-ares for 98 * asynchronous name resolves. This can be Windows or *nix. 99 * 100 * CURLRES_THREADED - is defined if libcurl is built to run under (native) 101 * Windows, and then the name resolve will be done in a new thread, and the 102 * supported API will be the same as for ares-builds. 103 * 104 * If any of the two previous are defined, CURLRES_ASYNCH is defined too. If 105 * libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is 106 * defined. 107 * 108 * The host*.c sources files are split up like this: 109 * 110 * hostip.c - method-independent resolver functions and utility functions 111 * hostasyn.c - functions for asynchronous name resolves 112 * hostsyn.c - functions for synchronous name resolves 113 * hostip4.c - ipv4-specific functions 114 * hostip6.c - ipv6-specific functions 115 * 116 * The two asynchronous name resolver backends are implemented in: 117 * asyn-ares.c - functions for ares-using name resolves 118 * asyn-thread.c - functions for threaded name resolves 119 120 * The hostip.h is the united header file for all this. It defines the 121 * CURLRES_* defines based on the config*.h and setup.h defines. 122 */ 123 124/* These two symbols are for the global DNS cache */ 125static struct curl_hash hostname_cache; 126static int host_cache_initialized; 127 128static void freednsentry(void *freethis); 129 130/* 131 * Curl_global_host_cache_init() initializes and sets up a global DNS cache. 132 * Global DNS cache is general badness. Do not use. This will be removed in 133 * a future version. Use the share interface instead! 134 * 135 * Returns a struct curl_hash pointer on success, NULL on failure. 136 */ 137struct curl_hash *Curl_global_host_cache_init(void) 138{ 139 int rc = 0; 140 if(!host_cache_initialized) { 141 rc = Curl_hash_init(&hostname_cache, 7, Curl_hash_str, 142 Curl_str_key_compare, freednsentry); 143 if(!rc) 144 host_cache_initialized = 1; 145 } 146 return rc?NULL:&hostname_cache; 147} 148 149/* 150 * Destroy and cleanup the global DNS cache 151 */ 152void Curl_global_host_cache_dtor(void) 153{ 154 if(host_cache_initialized) { 155 Curl_hash_clean(&hostname_cache); 156 host_cache_initialized = 0; 157 } 158} 159 160/* 161 * Return # of adresses in a Curl_addrinfo struct 162 */ 163int Curl_num_addresses(const Curl_addrinfo *addr) 164{ 165 int i = 0; 166 while(addr) { 167 addr = addr->ai_next; 168 i++; 169 } 170 return i; 171} 172 173/* 174 * Curl_printable_address() returns a printable version of the 1st address 175 * given in the 'ai' argument. The result will be stored in the buf that is 176 * bufsize bytes big. 177 * 178 * If the conversion fails, it returns NULL. 179 */ 180const char * 181Curl_printable_address(const Curl_addrinfo *ai, char *buf, size_t bufsize) 182{ 183 const struct sockaddr_in *sa4; 184 const struct in_addr *ipaddr4; 185#ifdef ENABLE_IPV6 186 const struct sockaddr_in6 *sa6; 187 const struct in6_addr *ipaddr6; 188#endif 189 190 switch (ai->ai_family) { 191 case AF_INET: 192 sa4 = (const void *)ai->ai_addr; 193 ipaddr4 = &sa4->sin_addr; 194 return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf, 195 bufsize); 196#ifdef ENABLE_IPV6 197 case AF_INET6: 198 sa6 = (const void *)ai->ai_addr; 199 ipaddr6 = &sa6->sin6_addr; 200 return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf, 201 bufsize); 202#endif 203 default: 204 break; 205 } 206 return NULL; 207} 208 209/* 210 * Return a hostcache id string for the providing host + port, to be used by 211 * the DNS caching. 212 */ 213static char * 214create_hostcache_id(const char *server, int port) 215{ 216 /* create and return the new allocated entry */ 217 return aprintf("%s:%d", server, port); 218} 219 220struct hostcache_prune_data { 221 long cache_timeout; 222 time_t now; 223}; 224 225/* 226 * This function is set as a callback to be called for every entry in the DNS 227 * cache when we want to prune old unused entries. 228 * 229 * Returning non-zero means remove the entry, return 0 to keep it in the 230 * cache. 231 */ 232static int 233hostcache_timestamp_remove(void *datap, void *hc) 234{ 235 struct hostcache_prune_data *data = 236 (struct hostcache_prune_data *) datap; 237 struct Curl_dns_entry *c = (struct Curl_dns_entry *) hc; 238 239 return (data->now - c->timestamp >= data->cache_timeout); 240} 241 242/* 243 * Prune the DNS cache. This assumes that a lock has already been taken. 244 */ 245static void 246hostcache_prune(struct curl_hash *hostcache, long cache_timeout, time_t now) 247{ 248 struct hostcache_prune_data user; 249 250 user.cache_timeout = cache_timeout; 251 user.now = now; 252 253 Curl_hash_clean_with_criterium(hostcache, 254 (void *) &user, 255 hostcache_timestamp_remove); 256} 257 258/* 259 * Library-wide function for pruning the DNS cache. This function takes and 260 * returns the appropriate locks. 261 */ 262void Curl_hostcache_prune(struct SessionHandle *data) 263{ 264 time_t now; 265 266 if((data->set.dns_cache_timeout == -1) || !data->dns.hostcache) 267 /* cache forever means never prune, and NULL hostcache means 268 we can't do it */ 269 return; 270 271 if(data->share) 272 Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); 273 274 time(&now); 275 276 /* Remove outdated and unused entries from the hostcache */ 277 hostcache_prune(data->dns.hostcache, 278 data->set.dns_cache_timeout, 279 now); 280 281 if(data->share) 282 Curl_share_unlock(data, CURL_LOCK_DATA_DNS); 283} 284 285/* 286 * Check if the entry should be pruned. Assumes a locked cache. 287 */ 288static int 289remove_entry_if_stale(struct SessionHandle *data, struct Curl_dns_entry *dns) 290{ 291 struct hostcache_prune_data user; 292 293 if(!dns || (data->set.dns_cache_timeout == -1) || !data->dns.hostcache) 294 /* cache forever means never prune, and NULL hostcache means 295 we can't do it */ 296 return 0; 297 298 time(&user.now); 299 user.cache_timeout = data->set.dns_cache_timeout; 300 301 if(!hostcache_timestamp_remove(&user,dns) ) 302 return 0; 303 304 Curl_hash_clean_with_criterium(data->dns.hostcache, 305 (void *) &user, 306 hostcache_timestamp_remove); 307 308 return 1; 309} 310 311 312#ifdef HAVE_SIGSETJMP 313/* Beware this is a global and unique instance. This is used to store the 314 return address that we can jump back to from inside a signal handler. This 315 is not thread-safe stuff. */ 316sigjmp_buf curl_jmpenv; 317#endif 318 319 320/* 321 * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache. 322 * 323 * When calling Curl_resolv() has resulted in a response with a returned 324 * address, we call this function to store the information in the dns 325 * cache etc 326 * 327 * Returns the Curl_dns_entry entry pointer or NULL if the storage failed. 328 */ 329struct Curl_dns_entry * 330Curl_cache_addr(struct SessionHandle *data, 331 Curl_addrinfo *addr, 332 const char *hostname, 333 int port) 334{ 335 char *entry_id; 336 size_t entry_len; 337 struct Curl_dns_entry *dns; 338 struct Curl_dns_entry *dns2; 339 340 /* Create an entry id, based upon the hostname and port */ 341 entry_id = create_hostcache_id(hostname, port); 342 /* If we can't create the entry id, fail */ 343 if(!entry_id) 344 return NULL; 345 entry_len = strlen(entry_id); 346 347 /* Create a new cache entry */ 348 dns = calloc(1, sizeof(struct Curl_dns_entry)); 349 if(!dns) { 350 free(entry_id); 351 return NULL; 352 } 353 354 dns->inuse = 0; /* init to not used */ 355 dns->addr = addr; /* this is the address(es) */ 356 time(&dns->timestamp); 357 if(dns->timestamp == 0) 358 dns->timestamp = 1; /* zero indicates that entry isn't in hash table */ 359 360 /* Store the resolved data in our DNS cache. */ 361 dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len+1, 362 (void *)dns); 363 if(!dns2) { 364 free(dns); 365 free(entry_id); 366 return NULL; 367 } 368 369 dns = dns2; 370 dns->inuse++; /* mark entry as in-use */ 371 372 /* free the allocated entry_id */ 373 free(entry_id); 374 375 return dns; 376} 377 378/* 379 * Curl_resolv() is the main name resolve function within libcurl. It resolves 380 * a name and returns a pointer to the entry in the 'entry' argument (if one 381 * is provided). This function might return immediately if we're using asynch 382 * resolves. See the return codes. 383 * 384 * The cache entry we return will get its 'inuse' counter increased when this 385 * function is used. You MUST call Curl_resolv_unlock() later (when you're 386 * done using this struct) to decrease the counter again. 387 * 388 * In debug mode, we specifically test for an interface name "LocalHost" 389 * and resolve "localhost" instead as a means to permit test cases 390 * to connect to a local test server with any host name. 391 * 392 * Return codes: 393 * 394 * CURLRESOLV_ERROR (-1) = error, no pointer 395 * CURLRESOLV_RESOLVED (0) = OK, pointer provided 396 * CURLRESOLV_PENDING (1) = waiting for response, no pointer 397 */ 398 399int Curl_resolv(struct connectdata *conn, 400 const char *hostname, 401 int port, 402 struct Curl_dns_entry **entry) 403{ 404 char *entry_id = NULL; 405 struct Curl_dns_entry *dns = NULL; 406 size_t entry_len; 407 struct SessionHandle *data = conn->data; 408 CURLcode result; 409 int rc = CURLRESOLV_ERROR; /* default to failure */ 410 411 *entry = NULL; 412 413 /* Create an entry id, based upon the hostname and port */ 414 entry_id = create_hostcache_id(hostname, port); 415 /* If we can't create the entry id, fail */ 416 if(!entry_id) 417 return rc; 418 419 entry_len = strlen(entry_id); 420 421 if(data->share) 422 Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); 423 424 /* See if its already in our dns cache */ 425 dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1); 426 427 /* free the allocated entry_id again */ 428 free(entry_id); 429 430 /* See whether the returned entry is stale. Done before we release lock */ 431 if(remove_entry_if_stale(data, dns)) 432 dns = NULL; /* the memory deallocation is being handled by the hash */ 433 434 if(dns) { 435 dns->inuse++; /* we use it! */ 436 rc = CURLRESOLV_RESOLVED; 437 } 438 439 if(data->share) 440 Curl_share_unlock(data, CURL_LOCK_DATA_DNS); 441 442 if(!dns) { 443 /* The entry was not in the cache. Resolve it to IP address */ 444 445 Curl_addrinfo *addr; 446 int respwait; 447 448 /* Check what IP specifics the app has requested and if we can provide it. 449 * If not, bail out. */ 450 if(!Curl_ipvalid(conn)) 451 return CURLRESOLV_ERROR; 452 453 /* If Curl_getaddrinfo() returns NULL, 'respwait' might be set to a 454 non-zero value indicating that we need to wait for the response to the 455 resolve call */ 456 addr = Curl_getaddrinfo(conn, 457#ifdef DEBUGBUILD 458 (data->set.str[STRING_DEVICE] 459 && !strcmp(data->set.str[STRING_DEVICE], 460 "LocalHost"))?"localhost": 461#endif 462 hostname, port, &respwait); 463 464 if(!addr) { 465 if(respwait) { 466 /* the response to our resolve call will come asynchronously at 467 a later time, good or bad */ 468 /* First, check that we haven't received the info by now */ 469 result = Curl_resolver_is_resolved(conn, &dns); 470 if(result) /* error detected */ 471 return CURLRESOLV_ERROR; 472 if(dns) 473 rc = CURLRESOLV_RESOLVED; /* pointer provided */ 474 else 475 rc = CURLRESOLV_PENDING; /* no info yet */ 476 } 477 } 478 else { 479 if(data->share) 480 Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); 481 482 /* we got a response, store it in the cache */ 483 dns = Curl_cache_addr(data, addr, hostname, port); 484 485 if(data->share) 486 Curl_share_unlock(data, CURL_LOCK_DATA_DNS); 487 488 if(!dns) 489 /* returned failure, bail out nicely */ 490 Curl_freeaddrinfo(addr); 491 else 492 rc = CURLRESOLV_RESOLVED; 493 } 494 } 495 496 *entry = dns; 497 498 return rc; 499} 500 501#ifdef USE_ALARM_TIMEOUT 502/* 503 * This signal handler jumps back into the main libcurl code and continues 504 * execution. This effectively causes the remainder of the application to run 505 * within a signal handler which is nonportable and could lead to problems. 506 */ 507static 508RETSIGTYPE alarmfunc(int sig) 509{ 510 /* this is for "-ansi -Wall -pedantic" to stop complaining! (rabe) */ 511 (void)sig; 512 siglongjmp(curl_jmpenv, 1); 513 return; 514} 515#endif /* USE_ALARM_TIMEOUT */ 516 517/* 518 * Curl_resolv_timeout() is the same as Curl_resolv() but specifies a 519 * timeout. This function might return immediately if we're using asynch 520 * resolves. See the return codes. 521 * 522 * The cache entry we return will get its 'inuse' counter increased when this 523 * function is used. You MUST call Curl_resolv_unlock() later (when you're 524 * done using this struct) to decrease the counter again. 525 * 526 * If built with a synchronous resolver and use of signals is not 527 * disabled by the application, then a nonzero timeout will cause a 528 * timeout after the specified number of milliseconds. Otherwise, timeout 529 * is ignored. 530 * 531 * Return codes: 532 * 533 * CURLRESOLV_TIMEDOUT(-2) = warning, time too short or previous alarm expired 534 * CURLRESOLV_ERROR (-1) = error, no pointer 535 * CURLRESOLV_RESOLVED (0) = OK, pointer provided 536 * CURLRESOLV_PENDING (1) = waiting for response, no pointer 537 */ 538 539int Curl_resolv_timeout(struct connectdata *conn, 540 const char *hostname, 541 int port, 542 struct Curl_dns_entry **entry, 543 long timeoutms) 544{ 545#ifdef USE_ALARM_TIMEOUT 546#ifdef HAVE_SIGACTION 547 struct sigaction keep_sigact; /* store the old struct here */ 548 volatile bool keep_copysig = FALSE; /* wether old sigact has been saved */ 549 struct sigaction sigact; 550#else 551#ifdef HAVE_SIGNAL 552 void (*keep_sigact)(int); /* store the old handler here */ 553#endif /* HAVE_SIGNAL */ 554#endif /* HAVE_SIGACTION */ 555 volatile long timeout; 556 volatile unsigned int prev_alarm = 0; 557 struct SessionHandle *data = conn->data; 558#endif /* USE_ALARM_TIMEOUT */ 559 int rc; 560 561 *entry = NULL; 562 563#ifdef USE_ALARM_TIMEOUT 564 if(data->set.no_signal) 565 /* Ignore the timeout when signals are disabled */ 566 timeout = 0; 567 else 568 timeout = timeoutms; 569 570 if(!timeout) 571 /* USE_ALARM_TIMEOUT defined, but no timeout actually requested */ 572 return Curl_resolv(conn, hostname, port, entry); 573 574 if(timeout < 1000) 575 /* The alarm() function only provides integer second resolution, so if 576 we want to wait less than one second we must bail out already now. */ 577 return CURLRESOLV_TIMEDOUT; 578 579 /************************************************************* 580 * Set signal handler to catch SIGALRM 581 * Store the old value to be able to set it back later! 582 *************************************************************/ 583#ifdef HAVE_SIGACTION 584 sigaction(SIGALRM, NULL, &sigact); 585 keep_sigact = sigact; 586 keep_copysig = TRUE; /* yes, we have a copy */ 587 sigact.sa_handler = alarmfunc; 588#ifdef SA_RESTART 589 /* HPUX doesn't have SA_RESTART but defaults to that behaviour! */ 590 sigact.sa_flags &= ~SA_RESTART; 591#endif 592 /* now set the new struct */ 593 sigaction(SIGALRM, &sigact, NULL); 594#else /* HAVE_SIGACTION */ 595 /* no sigaction(), revert to the much lamer signal() */ 596#ifdef HAVE_SIGNAL 597 keep_sigact = signal(SIGALRM, alarmfunc); 598#endif 599#endif /* HAVE_SIGACTION */ 600 601 /* alarm() makes a signal get sent when the timeout fires off, and that 602 will abort system calls */ 603 prev_alarm = alarm(curlx_sltoui(timeout/1000L)); 604 605 /* This allows us to time-out from the name resolver, as the timeout 606 will generate a signal and we will siglongjmp() from that here. 607 This technique has problems (see alarmfunc). 608 This should be the last thing we do before calling Curl_resolv(), 609 as otherwise we'd have to worry about variables that get modified 610 before we invoke Curl_resolv() (and thus use "volatile"). */ 611 if(sigsetjmp(curl_jmpenv, 1)) { 612 /* this is coming from a siglongjmp() after an alarm signal */ 613 failf(data, "name lookup timed out"); 614 rc = CURLRESOLV_ERROR; 615 goto clean_up; 616 } 617 618#else 619#ifndef CURLRES_ASYNCH 620 if(timeoutms) 621 infof(conn->data, "timeout on name lookup is not supported\n"); 622#else 623 (void)timeoutms; /* timeoutms not used with an async resolver */ 624#endif 625#endif /* USE_ALARM_TIMEOUT */ 626 627 /* Perform the actual name resolution. This might be interrupted by an 628 * alarm if it takes too long. 629 */ 630 rc = Curl_resolv(conn, hostname, port, entry); 631 632#ifdef USE_ALARM_TIMEOUT 633clean_up: 634 635 if(!prev_alarm) 636 /* deactivate a possibly active alarm before uninstalling the handler */ 637 alarm(0); 638 639#ifdef HAVE_SIGACTION 640 if(keep_copysig) { 641 /* we got a struct as it looked before, now put that one back nice 642 and clean */ 643 sigaction(SIGALRM, &keep_sigact, NULL); /* put it back */ 644 } 645#else 646#ifdef HAVE_SIGNAL 647 /* restore the previous SIGALRM handler */ 648 signal(SIGALRM, keep_sigact); 649#endif 650#endif /* HAVE_SIGACTION */ 651 652 /* switch back the alarm() to either zero or to what it was before minus 653 the time we spent until now! */ 654 if(prev_alarm) { 655 /* there was an alarm() set before us, now put it back */ 656 unsigned long elapsed_ms = Curl_tvdiff(Curl_tvnow(), conn->created); 657 658 /* the alarm period is counted in even number of seconds */ 659 unsigned long alarm_set = prev_alarm - elapsed_ms/1000; 660 661 if(!alarm_set || 662 ((alarm_set >= 0x80000000) && (prev_alarm < 0x80000000)) ) { 663 /* if the alarm time-left reached zero or turned "negative" (counted 664 with unsigned values), we should fire off a SIGALRM here, but we 665 won't, and zero would be to switch it off so we never set it to 666 less than 1! */ 667 alarm(1); 668 rc = CURLRESOLV_TIMEDOUT; 669 failf(data, "Previous alarm fired off!"); 670 } 671 else 672 alarm((unsigned int)alarm_set); 673 } 674#endif /* USE_ALARM_TIMEOUT */ 675 676 return rc; 677} 678 679/* 680 * Curl_resolv_unlock() unlocks the given cached DNS entry. When this has been 681 * made, the struct may be destroyed due to pruning. It is important that only 682 * one unlock is made for each Curl_resolv() call. 683 */ 684void Curl_resolv_unlock(struct SessionHandle *data, struct Curl_dns_entry *dns) 685{ 686 DEBUGASSERT(dns && (dns->inuse>0)); 687 688 if(data->share) 689 Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE); 690 691 dns->inuse--; 692 /* only free if nobody is using AND it is not in hostcache (timestamp == 693 0) */ 694 if(dns->inuse == 0 && dns->timestamp == 0) { 695 Curl_freeaddrinfo(dns->addr); 696 free(dns); 697 } 698 699 if(data->share) 700 Curl_share_unlock(data, CURL_LOCK_DATA_DNS); 701} 702 703/* 704 * File-internal: free a cache dns entry. 705 */ 706static void freednsentry(void *freethis) 707{ 708 struct Curl_dns_entry *p = (struct Curl_dns_entry *) freethis; 709 710 /* mark the entry as not in hostcache */ 711 p->timestamp = 0; 712 if(p->inuse == 0) { 713 Curl_freeaddrinfo(p->addr); 714 free(p); 715 } 716} 717 718/* 719 * Curl_mk_dnscache() creates a new DNS cache and returns the handle for it. 720 */ 721struct curl_hash *Curl_mk_dnscache(void) 722{ 723 return Curl_hash_alloc(7, Curl_hash_str, Curl_str_key_compare, freednsentry); 724} 725 726 727