summaryrefslogtreecommitdiff
path: root/lib/http_proxy.c
blob: 814c572f6f7e63301a175e8d3b50e32fd9af77d2 (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
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2016, 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.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 "curl_setup.h"

#if !defined(CURL_DISABLE_PROXY) && !defined(CURL_DISABLE_HTTP)

#include "urldata.h"
#include <curl/curl.h>
#include "http_proxy.h"
#include "sendf.h"
#include "http.h"
#include "url.h"
#include "select.h"
#include "rawstr.h"
#include "progress.h"
#include "non-ascii.h"
#include "connect.h"
#include "curlx.h"

/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"

CURLcode Curl_proxy_connect(struct connectdata *conn)
{
  if(conn->bits.tunnel_proxy && conn->bits.httpproxy) {
#ifndef CURL_DISABLE_PROXY
    /* for [protocol] tunneled through HTTP proxy */
    struct HTTP http_proxy;
    void *prot_save;
    const char *hostname;
    int remote_port;
    CURLcode result;

    /* BLOCKING */
    /* We want "seamless" operations through HTTP proxy tunnel */

    /* Curl_proxyCONNECT is based on a pointer to a struct HTTP at the
     * member conn->proto.http; we want [protocol] through HTTP and we have
     * to change the member temporarily for connecting to the HTTP
     * proxy. After Curl_proxyCONNECT we have to set back the member to the
     * original pointer
     *
     * This function might be called several times in the multi interface case
     * if the proxy's CONNTECT response is not instant.
     */
    prot_save = conn->data->req.protop;
    memset(&http_proxy, 0, sizeof(http_proxy));
    conn->data->req.protop = &http_proxy;
    connkeep(conn, "HTTP proxy CONNECT");
    if(conn->bits.conn_to_host)
      hostname = conn->conn_to_host.name;
    else
      hostname = conn->host.name;
    if(conn->bits.conn_to_port)
      remote_port = conn->conn_to_port;
    else
      remote_port = conn->remote_port;
    result = Curl_proxyCONNECT(conn, FIRSTSOCKET, hostname,
                               remote_port, FALSE);
    conn->data->req.protop = prot_save;
    if(CURLE_OK != result)
      return result;
    Curl_safefree(conn->allocptr.proxyuserpwd);
#else
    return CURLE_NOT_BUILT_IN;
#endif
  }
  /* no HTTP tunnel proxy, just return */
  return CURLE_OK;
}

/*
 * Curl_proxyCONNECT() requires that we're connected to a HTTP proxy. This
 * function will issue the necessary commands to get a seamless tunnel through
 * this proxy. After that, the socket can be used just as a normal socket.
 *
 * 'blocking' set to TRUE means that this function will do the entire CONNECT
 * + response in a blocking fashion. Should be avoided!
 */

CURLcode Curl_proxyCONNECT(struct connectdata *conn,
                           int sockindex,
                           const char *hostname,
                           int remote_port,
                           bool blocking)
{
  int subversion=0;
  struct SessionHandle *data=conn->data;
  struct SingleRequest *k = &data->req;
  CURLcode result;
  curl_socket_t tunnelsocket = conn->sock[sockindex];
  curl_off_t cl=0;
  bool closeConnection = FALSE;
  bool chunked_encoding = FALSE;
  long check;

#define SELECT_OK      0
#define SELECT_ERROR   1
#define SELECT_TIMEOUT 2
  int error = SELECT_OK;

  if(conn->tunnel_state[sockindex] == TUNNEL_COMPLETE)
    return CURLE_OK; /* CONNECT is already completed */

  conn->bits.proxy_connect_closed = FALSE;

  do {
    if(TUNNEL_INIT == conn->tunnel_state[sockindex]) {
      /* BEGIN CONNECT PHASE */
      char *host_port;
      Curl_send_buffer *req_buffer;

      infof(data, "Establish HTTP proxy tunnel to %s:%hu\n",
            hostname, remote_port);

        /* This only happens if we've looped here due to authentication
           reasons, and we don't really use the newly cloned URL here
           then. Just free() it. */
      free(data->req.newurl);
      data->req.newurl = NULL;

      /* initialize a dynamic send-buffer */
      req_buffer = Curl_add_buffer_init();

      if(!req_buffer)
        return CURLE_OUT_OF_MEMORY;

      host_port = aprintf("%s:%hu", hostname, remote_port);
      if(!host_port) {
        Curl_add_buffer_free(req_buffer);
        return CURLE_OUT_OF_MEMORY;
      }

      /* Setup the proxy-authorization header, if any */
      result = Curl_http_output_auth(conn, "CONNECT", host_port, TRUE);

      free(host_port);

      if(!result) {
        char *host=(char *)"";
        const char *useragent="";
        const char *http = (conn->proxytype == CURLPROXY_HTTP_1_0) ?
          "1.0" : "1.1";
        bool ipv6_ip = conn->bits.ipv6_ip;
        char *hostheader;

        /* the hostname may be different */
        if(hostname != conn->host.name)
          ipv6_ip = (strchr(hostname, ':') != NULL);
        hostheader= /* host:port with IPv6 support */
          aprintf("%s%s%s:%hu", ipv6_ip?"[":"", hostname, ipv6_ip?"]":"",
                  remote_port);
        if(!hostheader) {
          Curl_add_buffer_free(req_buffer);
          return CURLE_OUT_OF_MEMORY;
        }

        if(!Curl_checkProxyheaders(conn, "Host:")) {
          host = aprintf("Host: %s\r\n", hostheader);
          if(!host) {
            free(hostheader);
            Curl_add_buffer_free(req_buffer);
            return CURLE_OUT_OF_MEMORY;
          }
        }
        if(!Curl_checkProxyheaders(conn, "User-Agent:") &&
           data->set.str[STRING_USERAGENT])
          useragent = conn->allocptr.uagent;

        result =
          Curl_add_bufferf(req_buffer,
                           "CONNECT %s HTTP/%s\r\n"
                           "%s"  /* Host: */
                           "%s"  /* Proxy-Authorization */
                           "%s", /* User-Agent */
                           hostheader,
                           http,
                           host,
                           conn->allocptr.proxyuserpwd?
                           conn->allocptr.proxyuserpwd:"",
                           useragent);

        if(host && *host)
          free(host);
        free(hostheader);

        if(!result)
          result = Curl_add_custom_headers(conn, TRUE, req_buffer);

        if(!result)
          /* CRLF terminate the request */
          result = Curl_add_bufferf(req_buffer, "\r\n");

        if(!result) {
          /* Send the connect request to the proxy */
          /* BLOCKING */
          result =
            Curl_add_buffer_send(req_buffer, conn,
                                 &data->info.request_size, 0, sockindex);
        }
        req_buffer = NULL;
        if(result)
          failf(data, "Failed sending CONNECT to proxy");
      }

      Curl_add_buffer_free(req_buffer);
      if(result)
        return result;

      conn->tunnel_state[sockindex] = TUNNEL_CONNECT;
    } /* END CONNECT PHASE */

    check = Curl_timeleft(data, NULL, TRUE);
    if(check <= 0) {
      failf(data, "Proxy CONNECT aborted due to timeout");
      return CURLE_RECV_ERROR;
    }

    if(!blocking) {
      if(0 == Curl_socket_ready(tunnelsocket, CURL_SOCKET_BAD, 0))
        /* return so we'll be called again polling-style */
        return CURLE_OK;
      else {
        DEBUGF(infof(data,
               "Read response immediately from proxy CONNECT\n"));
      }
    }

    /* at this point, the tunnel_connecting phase is over. */

    { /* READING RESPONSE PHASE */
      size_t nread;   /* total size read */
      int perline; /* count bytes per line */
      int keepon=TRUE;
      ssize_t gotbytes;
      char *ptr;
      char *line_start;

      ptr=data->state.buffer;
      line_start = ptr;

      nread=0;
      perline=0;

      while((nread<BUFSIZE) && (keepon && !error)) {

        check = Curl_timeleft(data, NULL, TRUE);
        if(check <= 0) {
          failf(data, "Proxy CONNECT aborted due to timeout");
          error = SELECT_TIMEOUT; /* already too little time */
          break;
        }

        /* loop every second at least, less if the timeout is near */
        switch (Curl_socket_ready(tunnelsocket, CURL_SOCKET_BAD,
                                  check<1000L?check:1000)) {
        case -1: /* select() error, stop reading */
          error = SELECT_ERROR;
          failf(data, "Proxy CONNECT aborted due to select/poll error");
          break;
        case 0: /* timeout */
          break;
        default:
          DEBUGASSERT(ptr+BUFSIZE-nread <= data->state.buffer+BUFSIZE+1);
          result = Curl_read(conn, tunnelsocket, ptr, BUFSIZE-nread,
                             &gotbytes);
          if(result==CURLE_AGAIN)
            continue; /* go loop yourself */
          else if(result)
            keepon = FALSE;
          else if(gotbytes <= 0) {
            keepon = FALSE;
            if(data->set.proxyauth && data->state.authproxy.avail) {
              /* proxy auth was requested and there was proxy auth available,
                 then deem this as "mere" proxy disconnect */
              conn->bits.proxy_connect_closed = TRUE;
              infof(data, "Proxy CONNECT connection closed\n");
            }
            else {
              error = SELECT_ERROR;
              failf(data, "Proxy CONNECT aborted");
            }
          }
          else {
            /*
             * We got a whole chunk of data, which can be anything from one
             * byte to a set of lines and possibly just a piece of the last
             * line.
             */
            int i;

            nread += gotbytes;

            if(keepon > TRUE) {
              /* This means we are currently ignoring a response-body */

              nread = 0; /* make next read start over in the read buffer */
              ptr=data->state.buffer;
              if(cl) {
                /* A Content-Length based body: simply count down the counter
                   and make sure to break out of the loop when we're done! */
                cl -= gotbytes;
                if(cl<=0) {
                  keepon = FALSE;
                  break;
                }
              }
              else {
                /* chunked-encoded body, so we need to do the chunked dance
                   properly to know when the end of the body is reached */
                CHUNKcode r;
                ssize_t tookcareof=0;

                /* now parse the chunked piece of data so that we can
                   properly tell when the stream ends */
                r = Curl_httpchunk_read(conn, ptr, gotbytes, &tookcareof);
                if(r == CHUNKE_STOP) {
                  /* we're done reading chunks! */
                  infof(data, "chunk reading DONE\n");
                  keepon = FALSE;
                  /* we did the full CONNECT treatment, go COMPLETE */
                  conn->tunnel_state[sockindex] = TUNNEL_COMPLETE;
                }
                else
                  infof(data, "Read %zd bytes of chunk, continue\n",
                        tookcareof);
              }
            }
            else
              for(i = 0; i < gotbytes; ptr++, i++) {
                perline++; /* amount of bytes in this line so far */
                if(*ptr == 0x0a) {
                  char letter;
                  int writetype;

                  /* convert from the network encoding */
                  result = Curl_convert_from_network(data, line_start,
                                                     perline);
                  /* Curl_convert_from_network calls failf if unsuccessful */
                  if(result)
                    return result;

                  /* output debug if that is requested */
                  if(data->set.verbose)
                    Curl_debug(data, CURLINFO_HEADER_IN,
                               line_start, (size_t)perline, conn);

                  /* send the header to the callback */
                  writetype = CLIENTWRITE_HEADER;
                  if(data->set.include_header)
                    writetype |= CLIENTWRITE_BODY;

                  result = Curl_client_write(conn, writetype, line_start,
                                             perline);

                  data->info.header_size += (long)perline;
                  data->req.headerbytecount += (long)perline;

                  if(result)
                    return result;

                  /* Newlines are CRLF, so the CR is ignored as the line isn't
                     really terminated until the LF comes. Treat a following CR
                     as end-of-headers as well.*/

                  if(('\r' == line_start[0]) ||
                     ('\n' == line_start[0])) {
                    /* end of response-headers from the proxy */
                    nread = 0; /* make next read start over in the read
                                  buffer */
                    ptr=data->state.buffer;
                    if((407 == k->httpcode) && !data->state.authproblem) {
                      /* If we get a 407 response code with content length
                         when we have no auth problem, we must ignore the
                         whole response-body */
                      keepon = 2;

                      if(cl) {
                        infof(data, "Ignore %" CURL_FORMAT_CURL_OFF_T
                              " bytes of response-body\n", cl);

                        /* remove the remaining chunk of what we already
                           read */
                        cl -= (gotbytes - i);

                        if(cl<=0)
                          /* if the whole thing was already read, we are done!
                           */
                          keepon=FALSE;
                      }
                      else if(chunked_encoding) {
                        CHUNKcode r;
                        /* We set ignorebody true here since the chunked
                           decoder function will acknowledge that. Pay
                           attention so that this is cleared again when this
                           function returns! */
                        k->ignorebody = TRUE;
                        infof(data, "%zd bytes of chunk left\n", gotbytes-i);

                        if(line_start[1] == '\n') {
                          /* this can only be a LF if the letter at index 0
                             was a CR */
                          line_start++;
                          i++;
                        }

                        /* now parse the chunked piece of data so that we can
                           properly tell when the stream ends */
                        r = Curl_httpchunk_read(conn, line_start+1,
                                                  gotbytes -i, &gotbytes);
                        if(r == CHUNKE_STOP) {
                          /* we're done reading chunks! */
                          infof(data, "chunk reading DONE\n");
                          keepon = FALSE;
                          /* we did the full CONNECT treatment, go to
                             COMPLETE */
                          conn->tunnel_state[sockindex] = TUNNEL_COMPLETE;
                        }
                        else
                          infof(data, "Read %zd bytes of chunk, continue\n",
                                gotbytes);
                      }
                      else {
                        /* without content-length or chunked encoding, we
                           can't keep the connection alive since the close is
                           the end signal so we bail out at once instead */
                        keepon=FALSE;
                      }
                    }
                    else {
                      keepon = FALSE;
                      if(200 == data->info.httpproxycode) {
                        if(gotbytes - (i+1))
                          failf(data, "Proxy CONNECT followed by %zd bytes "
                                "of opaque data. Data ignored (known bug #39)",
                                gotbytes - (i+1));
                      }
                    }
                    /* we did the full CONNECT treatment, go to COMPLETE */
                    conn->tunnel_state[sockindex] = TUNNEL_COMPLETE;
                    break; /* breaks out of for-loop, not switch() */
                  }

                  /* keep a backup of the position we are about to blank */
                  letter = line_start[perline];
                  line_start[perline]=0; /* zero terminate the buffer */
                  if((checkprefix("WWW-Authenticate:", line_start) &&
                      (401 == k->httpcode)) ||
                     (checkprefix("Proxy-authenticate:", line_start) &&
                      (407 == k->httpcode))) {

                    bool proxy = (k->httpcode == 407) ? TRUE : FALSE;
                    char *auth = Curl_copy_header_value(line_start);
                    if(!auth)
                      return CURLE_OUT_OF_MEMORY;

                    result = Curl_http_input_auth(conn, proxy, auth);

                    free(auth);

                    if(result)
                      return result;
                  }
                  else if(checkprefix("Content-Length:", line_start)) {
                    cl = curlx_strtoofft(line_start +
                                         strlen("Content-Length:"), NULL, 10);
                  }
                  else if(Curl_compareheader(line_start,
                                             "Connection:", "close"))
                    closeConnection = TRUE;
                  else if(Curl_compareheader(line_start,
                                             "Transfer-Encoding:",
                                             "chunked")) {
                    infof(data, "CONNECT responded chunked\n");
                    chunked_encoding = TRUE;
                    /* init our chunky engine */
                    Curl_httpchunk_init(conn);
                  }
                  else if(Curl_compareheader(line_start,
                                             "Proxy-Connection:", "close"))
                    closeConnection = TRUE;
                  else if(2 == sscanf(line_start, "HTTP/1.%d %d",
                                      &subversion,
                                      &k->httpcode)) {
                    /* store the HTTP code from the proxy */
                    data->info.httpproxycode = k->httpcode;
                  }
                  /* put back the letter we blanked out before */
                  line_start[perline]= letter;

                  perline=0; /* line starts over here */
                  line_start = ptr+1; /* this skips the zero byte we wrote */
                }
              }
          }
          break;
        } /* switch */
        if(Curl_pgrsUpdate(conn))
          return CURLE_ABORTED_BY_CALLBACK;
      } /* while there's buffer left and loop is requested */

      if(error)
        return CURLE_RECV_ERROR;

      if(data->info.httpproxycode != 200) {
        /* Deal with the possibly already received authenticate
           headers. 'newurl' is set to a new URL if we must loop. */
        result = Curl_http_auth_act(conn);
        if(result)
          return result;

        if(conn->bits.close)
          /* the connection has been marked for closure, most likely in the
             Curl_http_auth_act() function and thus we can kill it at once
             below
          */
          closeConnection = TRUE;
      }

      if(closeConnection && data->req.newurl) {
        /* Connection closed by server. Don't use it anymore */
        Curl_closesocket(conn, conn->sock[sockindex]);
        conn->sock[sockindex] = CURL_SOCKET_BAD;
        break;
      }
    } /* END READING RESPONSE PHASE */

    /* If we are supposed to continue and request a new URL, which basically
     * means the HTTP authentication is still going on so if the tunnel
     * is complete we start over in INIT state */
    if(data->req.newurl &&
       (TUNNEL_COMPLETE == conn->tunnel_state[sockindex])) {
      conn->tunnel_state[sockindex] = TUNNEL_INIT;
      infof(data, "TUNNEL_STATE switched to: %d\n",
            conn->tunnel_state[sockindex]);
    }

  } while(data->req.newurl);

  if(200 != data->req.httpcode) {
    if(closeConnection && data->req.newurl) {
      conn->bits.proxy_connect_closed = TRUE;
      infof(data, "Connect me again please\n");
    }
    else {
      free(data->req.newurl);
      data->req.newurl = NULL;
      /* failure, close this connection to avoid re-use */
      connclose(conn, "proxy CONNECT failure");
      Curl_closesocket(conn, conn->sock[sockindex]);
      conn->sock[sockindex] = CURL_SOCKET_BAD;
    }

    /* to back to init state */
    conn->tunnel_state[sockindex] = TUNNEL_INIT;

    if(conn->bits.proxy_connect_closed)
      /* this is not an error, just part of the connection negotiation */
      return CURLE_OK;
    else {
      failf(data, "Received HTTP code %d from proxy after CONNECT",
            data->req.httpcode);
      return CURLE_RECV_ERROR;
    }
  }

  conn->tunnel_state[sockindex] = TUNNEL_COMPLETE;

  /* If a proxy-authorization header was used for the proxy, then we should
     make sure that it isn't accidentally used for the document request
     after we've connected. So let's free and clear it here. */
  Curl_safefree(conn->allocptr.proxyuserpwd);
  conn->allocptr.proxyuserpwd = NULL;

  data->state.authproxy.done = TRUE;

  infof (data, "Proxy replied OK to CONNECT request\n");
  data->req.ignorebody = FALSE; /* put it (back) to non-ignore state */
  conn->bits.rewindaftersend = FALSE; /* make sure this isn't set for the
                                         document request  */
  return CURLE_OK;
}
#endif /* CURL_DISABLE_PROXY */