CMakeLua/Utilities/cmcurl/hostip.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: hostip.c,v 1.2 2007/03/15 19:22:13 andy Exp $
  22  ***************************************************************************/
  23
  24 #include "setup.h"
  25
  26 #include <string.h>
  27
  28 #ifdef NEED_MALLOC_H
  29 #include <malloc.h>
  30 #endif
  31 #ifdef HAVE_SYS_TYPES_H
  32 #include <sys/types.h>
  33 #endif
  34 #ifdef HAVE_SYS_SOCKET_H
  35 #include <sys/socket.h>
  36 #endif
  37 #ifdef HAVE_NETINET_IN_H
  38 #include <netinet/in.h>
  39 #endif
  40 #ifdef HAVE_NETDB_H
  41 #include <netdb.h>
  42 #endif
  43 #ifdef HAVE_ARPA_INET_H
  44 #include <arpa/inet.h>
  45 #endif
  46 #ifdef HAVE_STDLIB_H
  47 #include <stdlib.h>     /* required for free() prototypes */
  48 #endif
  49 #ifdef HAVE_UNISTD_H
  50 #include <unistd.h>     /* for the close() proto */
  51 #endif
  52 #ifdef  VMS
  53 #include <in.h>
  54 #include <inet.h>
  55 #include <stdlib.h>
  56 #endif
  57
  58 #ifdef HAVE_SETJMP_H
  59 #include <setjmp.h>
  60 #endif
  61
  62 #ifdef HAVE_PROCESS_H
  63 #include <process.h>
  64 #endif
  65
  66 #include "urldata.h"
  67 #include "sendf.h"
  68 #include "hostip.h"
  69 #include "hash.h"
  70 #include "share.h"
  71 #include "strerror.h"
  72 #include "url.h"
  73 #include "inet_ntop.h"
  74
  75 #define _MPRINTF_REPLACE /* use our functions only */
  76 #include <curl/mprintf.h>
  77
  78 #if defined(HAVE_INET_NTOA_R) && !defined(HAVE_INET_NTOA_R_DECL)
  79 #include "inet_ntoa_r.h"
  80 #endif
  81
  82 #include "memory.h"
  83 /* The last #include file should be: */
  84 #include "memdebug.h"
  85
  86 /*
  87  * hostip.c explained
  88  * ==================
  89  *
  90  * The main COMPILE-TIME DEFINES to keep in mind when reading the host*.c
  91  * source file are these:
  92  *
  93  * CURLRES_IPV6 - this host has getaddrinfo() and family, and thus we use
  94  * that. The host may not be able to resolve IPv6, but we don't really have to
  95  * take that into account. Hosts that aren't IPv6-enabled have CURLRES_IPV4
  96  * defined.
  97  *
  98  * CURLRES_ARES - is defined if libcurl is built to use c-ares for
  99  * asynchronous name resolves. This can be Windows or *nix.
 100  *
 101  * CURLRES_THREADED - is defined if libcurl is built to run under (native)
 102  * Windows, and then the name resolve will be done in a new thread, and the
 103  * supported API will be the same as for ares-builds.
 104  *
 105  * If any of the two previous are defined, CURLRES_ASYNCH is defined too. If
 106  * libcurl is not built to use an asynchronous resolver, CURLRES_SYNCH is
 107  * defined.
 108  *
 109  * The host*.c sources files are split up like this:
 110  *
 111  * hostip.c   - method-independent resolver functions and utility functions
 112  * hostasyn.c - functions for asynchronous name resolves
 113  * hostsyn.c  - functions for synchronous name resolves
 114  * hostares.c - functions for ares-using name resolves
 115  * hostthre.c - functions for threaded name resolves
 116  * hostip4.c  - ipv4-specific functions
 117  * hostip6.c  - ipv6-specific functions
 118  *
 119  * The hostip.h is the united header file for all this. It defines the
 120  * CURLRES_* defines based on the config*.h and setup.h defines.
 121  */
 122
 123 /* These two symbols are for the global DNS cache */
 124 static struct curl_hash hostname_cache;
 125 static int host_cache_initialized;
 126
 127 static void freednsentry(void *freethis);
 128
 129 /*
 130  * Curl_global_host_cache_init() initializes and sets up a global DNS cache.
 131  * Global DNS cache is general badness. Do not use. This will be removed in
 132  * a future version. Use the share interface instead!
 133  */
 134 void Curl_global_host_cache_init(void)
 135 {
 136   if (!host_cache_initialized) {
 137     Curl_hash_init(&hostname_cache, 7, freednsentry);
 138     host_cache_initialized = 1;
 139   }
 140 }
 141
 142 /*
 143  * Return a pointer to the global cache
 144  */
 145 struct curl_hash *Curl_global_host_cache_get(void)
 146 {
 147   return &hostname_cache;
 148 }
 149
 150 /*
 151  * Destroy and cleanup the global DNS cache
 152  */
 153 void Curl_global_host_cache_dtor(void)
 154 {
 155   if (host_cache_initialized) {
 156     Curl_hash_clean(&hostname_cache);
 157     host_cache_initialized = 0;
 158   }
 159 }
 160
 161 /*
 162  * Return # of adresses in a Curl_addrinfo struct
 163  */
 164 int Curl_num_addresses(const Curl_addrinfo *addr)
 165 {
 166   int i;
 167   for (i = 0; addr; addr = addr->ai_next, i++)
 168     ;  /* empty loop */
 169   return i;
 170 }
 171
 172 /*
 173  * Curl_printable_address() returns a printable version of the 1st address
 174  * given in the 'ip' argument. The result will be stored in the buf that is
 175  * bufsize bytes big.
 176  *
 177  * If the conversion fails, it returns NULL.
 178  */
 179 const char *Curl_printable_address(const Curl_addrinfo *ip,
 180                                    char *buf, size_t bufsize)
 181 {
 182   const void *ip4 = &((const struct sockaddr_in*)ip->ai_addr)->sin_addr;
 183   int af = ip->ai_family;
 184 #ifdef CURLRES_IPV6
 185   const void *ip6 = &((const struct sockaddr_in6*)ip->ai_addr)->sin6_addr;
 186 #else
 187   const void *ip6 = NULL;
 188 #endif
 189
 190   return Curl_inet_ntop(af, af == AF_INET ? ip4 : ip6, buf, bufsize);
 191 }
 192
 193 /*
 194  * Return a hostcache id string for the providing host + port, to be used by
 195  * the DNS caching.
 196  */
 197 static char *
 198 create_hostcache_id(const char *server, int port)
 199 {
 200   /* create and return the new allocated entry */
 201   return aprintf("%s:%d", server, port);
 202 }
 203
 204 struct hostcache_prune_data {
 205   int cache_timeout;
 206   time_t now;
 207 };
 208
 209 /*
 210  * This function is set as a callback to be called for every entry in the DNS
 211  * cache when we want to prune old unused entries.
 212  *
 213  * Returning non-zero means remove the entry, return 0 to keep it in the
 214  * cache.
 215  */
 216 static int
 217 hostcache_timestamp_remove(void *datap, void *hc)
 218 {
 219   struct hostcache_prune_data *data =
 220     (struct hostcache_prune_data *) datap;
 221   struct Curl_dns_entry *c = (struct Curl_dns_entry *) hc;
 222
 223   if ((data->now - c->timestamp < data->cache_timeout) ||
 224       c->inuse) {
 225     /* please don't remove */
 226     return 0;
 227   }
 228
 229   /* fine, remove */
 230   return 1;
 231 }
 232
 233 /*
 234  * Prune the DNS cache. This assumes that a lock has already been taken.
 235  */
 236 static void
 237 hostcache_prune(struct curl_hash *hostcache, int cache_timeout, time_t now)
 238 {
 239   struct hostcache_prune_data user;
 240
 241   user.cache_timeout = cache_timeout;
 242   user.now = now;
 243
 244   Curl_hash_clean_with_criterium(hostcache,
 245                                  (void *) &user,
 246                                  hostcache_timestamp_remove);
 247 }
 248
 249 /*
 250  * Library-wide function for pruning the DNS cache. This function takes and
 251  * returns the appropriate locks.
 252  */
 253 void Curl_hostcache_prune(struct SessionHandle *data)
 254 {
 255   time_t now;
 256
 257   if((data->set.dns_cache_timeout == -1) || !data->dns.hostcache)
 258     /* cache forever means never prune, and NULL hostcache means
 259        we can't do it */
 260     return;
 261
 262   if(data->share)
 263     Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 264
 265   time(&now);
 266
 267   /* Remove outdated and unused entries from the hostcache */
 268   hostcache_prune(data->dns.hostcache,
 269                   data->set.dns_cache_timeout,
 270                   now);
 271
 272   if(data->share)
 273     Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 274 }
 275
 276 static int
 277 remove_entry_if_stale(struct SessionHandle *data, struct Curl_dns_entry *dns)
 278 {
 279   struct hostcache_prune_data user;
 280
 281   if( !dns || (data->set.dns_cache_timeout == -1) || !data->dns.hostcache)
 282     /* cache forever means never prune, and NULL hostcache means
 283        we can't do it */
 284     return 0;
 285
 286   time(&user.now);
 287   user.cache_timeout = data->set.dns_cache_timeout;
 288
 289   if ( !hostcache_timestamp_remove(&user,dns) )
 290     return 0;
 291
 292   /* ok, we do need to clear the cache. although we need to remove just a
 293      single entry we clean the entire hash, as no explicit delete function
 294      is provided */
 295   if(data->share)
 296     Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 297
 298   Curl_hash_clean_with_criterium(data->dns.hostcache,
 299                                  (void *) &user,
 300                                  hostcache_timestamp_remove);
 301
 302   if(data->share)
 303     Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 304
 305   return 1;
 306 }
 307
 308
 309 #ifdef HAVE_SIGSETJMP
 310 /* Beware this is a global and unique instance. This is used to store the
 311    return address that we can jump back to from inside a signal handler. This
 312    is not thread-safe stuff. */
 313 sigjmp_buf curl_jmpenv;
 314 #endif
 315
 316
 317 /*
 318  * Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
 319  *
 320  * When calling Curl_resolv() has resulted in a response with a returned
 321  * address, we call this function to store the information in the dns
 322  * cache etc
 323  *
 324  * Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
 325  */
 326 struct Curl_dns_entry *
 327 Curl_cache_addr(struct SessionHandle *data,
 328                 Curl_addrinfo *addr,
 329                 const char *hostname,
 330                 int port)
 331 {
 332   char *entry_id;
 333   size_t entry_len;
 334   struct Curl_dns_entry *dns;
 335   struct Curl_dns_entry *dns2;
 336   time_t now;
 337
 338   /* Create an entry id, based upon the hostname and port */
 339   entry_id = create_hostcache_id(hostname, port);
 340   /* If we can't create the entry id, fail */
 341   if (!entry_id)
 342     return NULL;
 343   entry_len = strlen(entry_id);
 344
 345   /* Create a new cache entry */
 346   dns = (struct Curl_dns_entry *) calloc(sizeof(struct Curl_dns_entry), 1);
 347   if (!dns) {
 348     free(entry_id);
 349     return NULL;
 350   }
 351
 352   dns->inuse = 0;   /* init to not used */
 353   dns->addr = addr; /* this is the address(es) */
 354
 355   /* Store the resolved data in our DNS cache. This function may return a
 356      pointer to an existing struct already present in the hash, and it may
 357      return the same argument we pass in. Make no assumptions. */
 358   dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len+1,
 359                        (void *)dns);
 360   if(!dns2) {
 361     /* Major badness, run away. */
 362     free(dns);
 363     free(entry_id);
 364     return NULL;
 365   }
 366   time(&now);
 367   dns = dns2;
 368
 369   dns->timestamp = now; /* used now */
 370   dns->inuse++;         /* mark entry as in-use */
 371
 372   /* free the allocated entry_id again */
 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  * Return codes:
 389  *
 390  * CURLRESOLV_ERROR   (-1) = error, no pointer
 391  * CURLRESOLV_RESOLVED (0) = OK, pointer provided
 392  * CURLRESOLV_PENDING  (1) = waiting for response, no pointer
 393  */
 394
 395 int Curl_resolv(struct connectdata *conn,
 396                 const char *hostname,
 397                 int port,
 398                 struct Curl_dns_entry **entry)
 399 {
 400   char *entry_id = NULL;
 401   struct Curl_dns_entry *dns = NULL;
 402   size_t entry_len;
 403   int wait;
 404   struct SessionHandle *data = conn->data;
 405   CURLcode result;
 406   int rc;
 407   *entry = NULL;
 408
 409 #ifdef HAVE_SIGSETJMP
 410   /* this allows us to time-out from the name resolver, as the timeout
 411      will generate a signal and we will siglongjmp() from that here */
 412   if(!data->set.no_signal) {
 413     if (sigsetjmp(curl_jmpenv, 1)) {
 414       /* this is coming from a siglongjmp() */
 415       failf(data, "name lookup timed out");
 416       return CURLRESOLV_ERROR;
 417     }
 418   }
 419 #endif
 420
 421   /* Create an entry id, based upon the hostname and port */
 422   entry_id = create_hostcache_id(hostname, port);
 423   /* If we can't create the entry id, fail */
 424   if (!entry_id)
 425     return CURLRESOLV_ERROR;
 426
 427   entry_len = strlen(entry_id);
 428
 429   if(data->share)
 430     Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 431
 432   /* See if its already in our dns cache */
 433   dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
 434
 435   if(data->share)
 436     Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 437
 438   /* free the allocated entry_id again */
 439   free(entry_id);
 440
 441   /* See whether the returned entry is stale. Deliberately done after the
 442      locked block */
 443   if ( remove_entry_if_stale(data,dns) )
 444     dns = NULL; /* the memory deallocation is being handled by the hash */
 445
 446   rc = CURLRESOLV_ERROR; /* default to failure */
 447
 448   if (!dns) {
 449     /* The entry was not in the cache. Resolve it to IP address */
 450
 451     Curl_addrinfo *addr;
 452
 453     /* Check what IP specifics the app has requested and if we can provide it.
 454      * If not, bail out. */
 455     if(!Curl_ipvalid(data))
 456       return CURLRESOLV_ERROR;
 457
 458     /* If Curl_getaddrinfo() returns NULL, 'wait' might be set to a non-zero
 459        value indicating that we need to wait for the response to the resolve
 460        call */
 461     addr = Curl_getaddrinfo(conn, hostname, port, &wait);
 462
 463     if (!addr) {
 464       if(wait) {
 465         /* the response to our resolve call will come asynchronously at
 466            a later time, good or bad */
 467         /* First, check that we haven't received the info by now */
 468         result = Curl_is_resolved(conn, &dns);
 469         if(result) /* error detected */
 470           return CURLRESOLV_ERROR;
 471         if(dns)
 472           rc = CURLRESOLV_RESOLVED; /* pointer provided */
 473         else
 474           rc = CURLRESOLV_PENDING; /* no info yet */
 475       }
 476     }
 477     else {
 478       if(data->share)
 479         Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 480
 481       /* we got a response, store it in the cache */
 482       dns = Curl_cache_addr(data, addr, hostname, port);
 483
 484       if(data->share)
 485         Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 486
 487       if(!dns)
 488         /* returned failure, bail out nicely */
 489         Curl_freeaddrinfo(addr);
 490       else
 491         rc = CURLRESOLV_RESOLVED;
 492     }
 493   }
 494   else {
 495     if(data->share)
 496       Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 497     dns->inuse++; /* we use it! */
 498     if(data->share)
 499       Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 500     rc = CURLRESOLV_RESOLVED;
 501   }
 502
 503   *entry = dns;
 504
 505   return rc;
 506 }
 507
 508 /*
 509  * Curl_resolv_unlock() unlocks the given cached DNS entry. When this has been
 510  * made, the struct may be destroyed due to pruning. It is important that only
 511  * one unlock is made for each Curl_resolv() call.
 512  */
 513 void Curl_resolv_unlock(struct SessionHandle *data, struct Curl_dns_entry *dns)
 514 {
 515   curlassert(dns && (dns->inuse>0));
 516
 517   if(data->share)
 518     Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
 519
 520   dns->inuse--;
 521
 522   if(data->share)
 523     Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
 524 }
 525
 526 /*
 527  * File-internal: free a cache dns entry.
 528  */
 529 static void freednsentry(void *freethis)
 530 {
 531   struct Curl_dns_entry *p = (struct Curl_dns_entry *) freethis;
 532
 533   Curl_freeaddrinfo(p->addr);
 534
 535   free(p);
 536 }
 537
 538 /*
 539  * Curl_mk_dnscache() creates a new DNS cache and returns the handle for it.
 540  */
 541 struct curl_hash *Curl_mk_dnscache(void)
 542 {
 543   return Curl_hash_alloc(7, freednsentry);
 544 }
 545
 546 #ifdef CURLRES_ADDRINFO_COPY
 547
 548 /* align on even 64bit boundaries */
 549 #define MEMALIGN(x) ((x)+(8-(((unsigned long)(x))&0x7)))
 550
 551 /*
 552  * Curl_addrinfo_copy() performs a "deep" copy of a hostent into a buffer and
 553  * returns a pointer to the malloc()ed copy. You need to call free() on the
 554  * returned buffer when you're done with it.
 555  */
 556 Curl_addrinfo *Curl_addrinfo_copy(const void *org, int port)
 557 {
 558   const struct hostent *orig = org;
 559
 560   return Curl_he2ai(orig, port);
 561 }
 562 #endif /* CURLRES_ADDRINFO_COPY */
 563
 564 /***********************************************************************
 565  * Only for plain-ipv4 and c-ares builds
 566  **********************************************************************/
 567
 568 #if defined(CURLRES_IPV4) || defined(CURLRES_ARES)
 569 /*
 570  * This is a function for freeing name information in a protocol independent
 571  * way.
 572  */
 573 void Curl_freeaddrinfo(Curl_addrinfo *ai)
 574 {
 575   Curl_addrinfo *next;
 576
 577   /* walk over the list and free all entries */
 578   while(ai) {
 579     next = ai->ai_next;
 580     free(ai);
 581     ai = next;
 582   }
 583 }
 584
 585 struct namebuf {
 586   struct hostent hostentry;
 587   char *h_addr_list[2];
 588   struct in_addr addrentry;
 589   char h_name[16]; /* 123.123.123.123 = 15 letters is maximum */
 590 };
 591
 592 /*
 593  * Curl_ip2addr() takes a 32bit ipv4 internet address as input parameter
 594  * together with a pointer to the string version of the address, and it
 595  * returns a Curl_addrinfo chain filled in correctly with information for this
 596  * address/host.
 597  *
 598  * The input parameters ARE NOT checked for validity but they are expected
 599  * to have been checked already when this is called.
 600  */
 601 Curl_addrinfo *Curl_ip2addr(in_addr_t num, const char *hostname, int port)
 602 {
 603   Curl_addrinfo *ai;
 604   struct hostent *h;
 605   struct in_addr *addrentry;
 606   struct namebuf buffer;
 607   struct namebuf *buf = &buffer;
 608
 609   h = &buf->hostentry;
 610   h->h_addr_list = &buf->h_addr_list[0];
 611   addrentry = &buf->addrentry;
 612 #ifdef _CRAYC
 613   /* On UNICOS, s_addr is a bit field and for some reason assigning to it
 614    * doesn't work.  There must be a better fix than this ugly hack.
 615    */
 616   memcpy(addrentry, &num, SIZEOF_in_addr);
 617 #else
 618   addrentry->s_addr = num;
 619 #endif
 620   h->h_addr_list[0] = (char*)addrentry;
 621   h->h_addr_list[1] = NULL;
 622   h->h_addrtype = AF_INET;
 623   h->h_length = sizeof(*addrentry);
 624   h->h_name = &buf->h_name[0];
 625   h->h_aliases = NULL;
 626
 627   /* Now store the dotted version of the address */
 628   snprintf((char *)h->h_name, 16, "%s", hostname);
 629
 630   ai = Curl_he2ai(h, port);
 631
 632   return ai;
 633 }
 634 #endif
 635
 636