aboutsummaryrefslogtreecommitdiff
path: root/lib/hostares.c
blob: e31a677dac130ce796043f88a4b98ec00c4a7d6f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2010, 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 http://curl.haxx.se/docs/copyright.html.
 *
 * 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.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "setup.h"

#include <string.h>

#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#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 HAVE_STDLIB_H
#include <stdlib.h>     /* required for free() prototypes */
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>     /* for the close() proto */
#endif
#ifdef __VMS
#include <in.h>
#include <inet.h>
#include <stdlib.h>
#endif

#ifdef HAVE_PROCESS_H
#include <process.h>
#endif

#if (defined(NETWARE) && defined(__NOVELL_LIBC__))
#undef in_addr_t
#define in_addr_t unsigned long
#endif

#include "urldata.h"
#include "sendf.h"
#include "hostip.h"
#include "hash.h"
#include "share.h"
#include "strerror.h"
#include "url.h"
#include "multiif.h"
#include "inet_pton.h"
#include "connect.h"
#include "select.h"
#include "progress.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"

/***********************************************************************
 * Only for ares-enabled builds
 **********************************************************************/

#ifdef CURLRES_ARES

/*
 * Curl_resolv_fdset() is called when someone from the outside world (using
 * curl_multi_fdset()) wants to get our fd_set setup and we're talking with
 * ares. The caller must make sure that this function is only called when we
 * have a working ares channel.
 *
 * Returns: CURLE_OK always!
 */

int Curl_resolv_getsock(struct connectdata *conn,
                        curl_socket_t *socks,
                        int numsocks)

{
  struct timeval maxtime;
  struct timeval timebuf;
  struct timeval *timeout;
  int max = ares_getsock(conn->data->state.areschannel,
                         (ares_socket_t *)socks, numsocks);


  maxtime.tv_sec = CURL_TIMEOUT_RESOLVE;
  maxtime.tv_usec = 0;

  timeout = ares_timeout(conn->data->state.areschannel, &maxtime, &timebuf);

  Curl_expire(conn->data,
              (timeout->tv_sec * 1000) + (timeout->tv_usec/1000));

  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 connectdata *conn, int timeout_ms)
{
  struct SessionHandle *data = conn->data;
  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(data->state.areschannel, 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 != 0)
      num++;
    else
      break;
  }

  if(num)
    nfds = Curl_poll(pfd, num, timeout_ms);
  else
    nfds = 0;

  if(!nfds)
    /* Call ares_process() unconditonally here, even if we simply timed out
       above, as otherwise the ares name resolve won't timeout! */
    ares_process_fd(data->state.areschannel, 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(data->state.areschannel,
                      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_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_is_resolved(struct connectdata *conn,
                          struct Curl_dns_entry **dns)
{
  struct SessionHandle *data = conn->data;

  *dns = NULL;

  waitperform(conn, 0);

  if(conn->async.done) {
    /* we're done, kill the ares handle */
    if(!conn->async.dns) {
      failf(data, "Could not resolve host: %s (%s)", conn->host.dispname,
            ares_strerror(conn->async.status));
      return CURLE_COULDNT_RESOLVE_HOST;
    }
    *dns = conn->async.dns;
  }

  return CURLE_OK;
}

/*
 * Curl_wait_for_resolv() waits for a resolve to finish. This function should
 * be avoided since using this risk getting the multi interface to "hang".
 *
 * If 'entry' is non-NULL, make it point to the resolved dns entry
 *
 * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved, and
 * CURLE_OPERATION_TIMEDOUT if a time-out occurred.
 */
CURLcode Curl_wait_for_resolv(struct connectdata *conn,
                              struct Curl_dns_entry **entry)
{
  CURLcode rc=CURLE_OK;
  struct SessionHandle *data = conn->data;
  long timeout;
  struct timeval now = Curl_tvnow();

  /* now, see if there's a connect timeout or a regular timeout to
     use instead of the default one */
  if(conn->data->set.connecttimeout)
    timeout = conn->data->set.connecttimeout;
  else if(conn->data->set.timeout)
    timeout = conn->data->set.timeout;
  else
    timeout = CURL_TIMEOUT_RESOLVE * 1000; /* default name resolve timeout */

  /* Wait for the name resolve query to complete. */
  for(;;) {
    struct timeval *tvp, tv, store;
    long timediff;
    int itimeout;
    int timeout_ms;

    itimeout = (timeout > (long)INT_MAX) ? INT_MAX : (int)timeout;

    store.tv_sec = itimeout/1000;
    store.tv_usec = (itimeout%1000)*1000;

    tvp = ares_timeout(data->state.areschannel, &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 = (int)(tvp->tv_usec/1000);
    else
      timeout_ms = 1000;

    waitperform(conn, timeout_ms);

    if(conn->async.done)
      break;

    if(Curl_pgrsUpdate(conn)) {
      rc = CURLE_ABORTED_BY_CALLBACK;
      timeout = -1; /* trigger the cancel below */
    }
    else {
      timediff = Curl_tvdiff(Curl_tvnow(), now); /* spent time */
      timeout -= timediff?timediff:1; /* always deduct at least 1 */
    }
    if(timeout < 0) {
      /* our timeout, so we cancel the ares operation */
      ares_cancel(data->state.areschannel);
      break;
    }
  }

  /* Operation complete, if the lookup was successful we now have the entry
     in the cache. */

  if(entry)
    *entry = conn->async.dns;

  if(!conn->async.dns) {
    /* a name was not resolved */
    if((timeout < 0) || (conn->async.status == ARES_ETIMEOUT)) {
      if (conn->bits.httpproxy) {
        failf(data, "Resolving proxy timed out: %s", conn->proxy.dispname);
        rc = CURLE_COULDNT_RESOLVE_PROXY;
      }
      else {
        failf(data, "Resolving host timed out: %s", conn->host.dispname);
        rc = CURLE_COULDNT_RESOLVE_HOST;
      }
    }
    else if(conn->async.done) {
      if (conn->bits.httpproxy) {
        failf(data, "Could not resolve proxy: %s (%s)", conn->proxy.dispname,
              ares_strerror(conn->async.status));
        rc = CURLE_COULDNT_RESOLVE_PROXY;
      }
      else {
        failf(data, "Could not resolve host: %s (%s)", conn->host.dispname,
              ares_strerror(conn->async.status));
        rc = CURLE_COULDNT_RESOLVE_HOST;
      }
    }
    else
      rc = CURLE_OPERATION_TIMEDOUT;

    /* close the connection, since we can't return failure here without
       cleaning up this connection properly */
    conn->bits.close = TRUE;
  }

  return rc;
}

/*
 * 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 ares_query_completed_cb(void *arg,  /* (struct connectdata *) */
                                    int status,
#ifdef HAVE_CARES_CALLBACK_TIMEOUTS
                                    int timeouts,
#endif
                                    struct hostent *hostent)
{
  struct connectdata *conn = (struct connectdata *)arg;
  struct Curl_addrinfo * ai = NULL;

#ifdef HAVE_CARES_CALLBACK_TIMEOUTS
  (void)timeouts; /* ignored */
#endif

  if (status == CURL_ASYNC_SUCCESS) {
    ai = Curl_he2ai(hostent, conn->async.port);
  }

  (void)Curl_addrinfo_callback(arg, status, ai);
}

/*
 * Curl_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.
 */
Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
                                const char *hostname,
                                int port,
                                int *waitp)
{
  char *bufp;
  struct SessionHandle *data = conn->data;
  struct in_addr in;
  int family = PF_INET;
#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
  struct in6_addr in6;
#endif /* CURLRES_IPV6 */

  *waitp = 0; /* default to synchronous response */

  /* First check if this is an IPv4 address string */
  if(Curl_inet_pton(AF_INET, hostname, &in) > 0) {
    /* This is a dotted IP address 123.123.123.123-style */
    return Curl_ip2addr(AF_INET, &in, hostname, port);
  }

#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */
  /* Otherwise, check if this is an IPv6 address string */
  if (Curl_inet_pton (AF_INET6, hostname, &in6) > 0) {
    /* This must be an IPv6 address literal.  */
    return Curl_ip2addr(AF_INET6, &in6, hostname, port);
  }

  switch(conn->ip_version) {
  default:
#if ARES_VERSION >= 0x010601
    family = PF_UNSPEC; /* supported by c-ares since 1.6.1, so for older
                           c-ares versions this just falls through and defaults
                           to PF_INET */
    break;
#endif
  case CURL_IPRESOLVE_V4:
    family = PF_INET;
    break;
  case CURL_IPRESOLVE_V6:
    family = PF_INET6;
    break;
  }
#endif /* CURLRES_IPV6 */

  bufp = strdup(hostname);

  if(bufp) {
    Curl_safefree(conn->async.hostname);
    conn->async.hostname = bufp;
    conn->async.port = port;
    conn->async.done = FALSE; /* not done */
    conn->async.status = 0;   /* clear */
    conn->async.dns = NULL;   /* clear */

    /* areschannel is already setup in the Curl_open() function */
    ares_gethostbyname(data->state.areschannel, hostname, family,
                       (ares_host_callback)ares_query_completed_cb, conn);

    *waitp = 1; /* expect asynchronous response */
  }
  return NULL; /* no struct yet */
}
#endif /* CURLRES_ARES */