1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, 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 https://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 "curl_setup.h"
24#include "strtoofft.h"
25
26#ifdef HAVE_NETINET_IN_H
27#include <netinet/in.h>
28#endif
29#ifdef HAVE_NETDB_H
30#include <netdb.h>
31#endif
32#ifdef HAVE_ARPA_INET_H
33#include <arpa/inet.h>
34#endif
35#ifdef HAVE_NET_IF_H
36#include <net/if.h>
37#endif
38#ifdef HAVE_SYS_IOCTL_H
39#include <sys/ioctl.h>
40#endif
41#ifdef HAVE_SIGNAL_H
42#include <signal.h>
43#endif
44
45#ifdef HAVE_SYS_PARAM_H
46#include <sys/param.h>
47#endif
48
49#ifdef HAVE_SYS_SELECT_H
50#include <sys/select.h>
51#endif
52
53#ifndef HAVE_SOCKET
54#error "We can't compile without socket() support!"
55#endif
56
57#include "urldata.h"
58#include <curl/curl.h>
59#include "netrc.h"
60
61#include "content_encoding.h"
62#include "hostip.h"
63#include "transfer.h"
64#include "sendf.h"
65#include "speedcheck.h"
66#include "progress.h"
67#include "http.h"
68#include "url.h"
69#include "getinfo.h"
70#include "vtls/vtls.h"
71#include "select.h"
72#include "multiif.h"
73#include "connect.h"
74#include "non-ascii.h"
75#include "http2.h"
76
77/* The last 3 #include files should be in this order */
78#include "curl_printf.h"
79#include "curl_memory.h"
80#include "memdebug.h"
81
82/*
83 * This function will call the read callback to fill our buffer with data
84 * to upload.
85 */
86CURLcode Curl_fillreadbuffer(struct connectdata *conn, int bytes, int *nreadp)
87{
88  struct Curl_easy *data = conn->data;
89  size_t buffersize = (size_t)bytes;
90  int nread;
91#ifdef CURL_DOES_CONVERSIONS
92  bool sending_http_headers = FALSE;
93
94  if(conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_RTSP)) {
95    const struct HTTP *http = data->req.protop;
96
97    if(http->sending == HTTPSEND_REQUEST)
98      /* We're sending the HTTP request headers, not the data.
99         Remember that so we don't re-translate them into garbage. */
100      sending_http_headers = TRUE;
101  }
102#endif
103
104  if(data->req.upload_chunky) {
105    /* if chunked Transfer-Encoding */
106    buffersize -= (8 + 2 + 2);   /* 32bit hex + CRLF + CRLF */
107    data->req.upload_fromhere += (8 + 2); /* 32bit hex + CRLF */
108  }
109
110  /* this function returns a size_t, so we typecast to int to prevent warnings
111     with picky compilers */
112  nread = (int)data->state.fread_func(data->req.upload_fromhere, 1,
113                                      buffersize, data->state.in);
114
115  if(nread == CURL_READFUNC_ABORT) {
116    failf(data, "operation aborted by callback");
117    *nreadp = 0;
118    return CURLE_ABORTED_BY_CALLBACK;
119  }
120  else if(nread == CURL_READFUNC_PAUSE) {
121
122    if(conn->handler->flags & PROTOPT_NONETWORK) {
123      /* protocols that work without network cannot be paused. This is
124         actually only FILE:// just now, and it can't pause since the transfer
125         isn't done using the "normal" procedure. */
126      failf(data, "Read callback asked for PAUSE when not supported!");
127      return CURLE_READ_ERROR;
128    }
129    else {
130      struct SingleRequest *k = &data->req;
131      /* CURL_READFUNC_PAUSE pauses read callbacks that feed socket writes */
132      k->keepon |= KEEP_SEND_PAUSE; /* mark socket send as paused */
133      if(data->req.upload_chunky) {
134        /* Back out the preallocation done above */
135        data->req.upload_fromhere -= (8 + 2);
136      }
137      *nreadp = 0;
138    }
139    return CURLE_OK; /* nothing was read */
140  }
141  else if((size_t)nread > buffersize) {
142    /* the read function returned a too large value */
143    *nreadp = 0;
144    failf(data, "read function returned funny value");
145    return CURLE_READ_ERROR;
146  }
147
148  if(!data->req.forbidchunk && data->req.upload_chunky) {
149    /* if chunked Transfer-Encoding
150     *    build chunk:
151     *
152     *        <HEX SIZE> CRLF
153     *        <DATA> CRLF
154     */
155    /* On non-ASCII platforms the <DATA> may or may not be
156       translated based on set.prefer_ascii while the protocol
157       portion must always be translated to the network encoding.
158       To further complicate matters, line end conversion might be
159       done later on, so we need to prevent CRLFs from becoming
160       CRCRLFs if that's the case.  To do this we use bare LFs
161       here, knowing they'll become CRLFs later on.
162     */
163
164    char hexbuffer[11];
165    const char *endofline_native;
166    const char *endofline_network;
167    int hexlen;
168
169    if(
170#ifdef CURL_DO_LINEEND_CONV
171       (data->set.prefer_ascii) ||
172#endif
173       (data->set.crlf)) {
174      /* \n will become \r\n later on */
175      endofline_native  = "\n";
176      endofline_network = "\x0a";
177    }
178    else {
179      endofline_native  = "\r\n";
180      endofline_network = "\x0d\x0a";
181    }
182    hexlen = snprintf(hexbuffer, sizeof(hexbuffer),
183                      "%x%s", nread, endofline_native);
184
185    /* move buffer pointer */
186    data->req.upload_fromhere -= hexlen;
187    nread += hexlen;
188
189    /* copy the prefix to the buffer, leaving out the NUL */
190    memcpy(data->req.upload_fromhere, hexbuffer, hexlen);
191
192    /* always append ASCII CRLF to the data */
193    memcpy(data->req.upload_fromhere + nread,
194           endofline_network,
195           strlen(endofline_network));
196
197#ifdef CURL_DOES_CONVERSIONS
198    CURLcode result;
199    int length;
200    if(data->set.prefer_ascii) {
201      /* translate the protocol and data */
202      length = nread;
203    }
204    else {
205      /* just translate the protocol portion */
206      length = strlen(hexbuffer);
207    }
208    result = Curl_convert_to_network(data, data->req.upload_fromhere, length);
209    /* Curl_convert_to_network calls failf if unsuccessful */
210    if(result)
211      return result;
212#endif /* CURL_DOES_CONVERSIONS */
213
214    if((nread - hexlen) == 0)
215      /* mark this as done once this chunk is transferred */
216      data->req.upload_done = TRUE;
217
218    nread+=(int)strlen(endofline_native); /* for the added end of line */
219  }
220#ifdef CURL_DOES_CONVERSIONS
221  else if((data->set.prefer_ascii) && (!sending_http_headers)) {
222    CURLcode result;
223    result = Curl_convert_to_network(data, data->req.upload_fromhere, nread);
224    /* Curl_convert_to_network calls failf if unsuccessful */
225    if(result)
226      return result;
227  }
228#endif /* CURL_DOES_CONVERSIONS */
229
230  *nreadp = nread;
231
232  return CURLE_OK;
233}
234
235
236/*
237 * Curl_readrewind() rewinds the read stream. This is typically used for HTTP
238 * POST/PUT with multi-pass authentication when a sending was denied and a
239 * resend is necessary.
240 */
241CURLcode Curl_readrewind(struct connectdata *conn)
242{
243  struct Curl_easy *data = conn->data;
244
245  conn->bits.rewindaftersend = FALSE; /* we rewind now */
246
247  /* explicitly switch off sending data on this connection now since we are
248     about to restart a new transfer and thus we want to avoid inadvertently
249     sending more data on the existing connection until the next transfer
250     starts */
251  data->req.keepon &= ~KEEP_SEND;
252
253  /* We have sent away data. If not using CURLOPT_POSTFIELDS or
254     CURLOPT_HTTPPOST, call app to rewind
255  */
256  if(data->set.postfields ||
257     (data->set.httpreq == HTTPREQ_POST_FORM))
258    ; /* do nothing */
259  else {
260    if(data->set.seek_func) {
261      int err;
262
263      err = (data->set.seek_func)(data->set.seek_client, 0, SEEK_SET);
264      if(err) {
265        failf(data, "seek callback returned error %d", (int)err);
266        return CURLE_SEND_FAIL_REWIND;
267      }
268    }
269    else if(data->set.ioctl_func) {
270      curlioerr err;
271
272      err = (data->set.ioctl_func)(data, CURLIOCMD_RESTARTREAD,
273                                   data->set.ioctl_client);
274      infof(data, "the ioctl callback returned %d\n", (int)err);
275
276      if(err) {
277        /* FIXME: convert to a human readable error message */
278        failf(data, "ioctl callback returned error %d", (int)err);
279        return CURLE_SEND_FAIL_REWIND;
280      }
281    }
282    else {
283      /* If no CURLOPT_READFUNCTION is used, we know that we operate on a
284         given FILE * stream and we can actually attempt to rewind that
285         ourselves with fseek() */
286      if(data->state.fread_func == (curl_read_callback)fread) {
287        if(-1 != fseek(data->state.in, 0, SEEK_SET))
288          /* successful rewind */
289          return CURLE_OK;
290      }
291
292      /* no callback set or failure above, makes us fail at once */
293      failf(data, "necessary data rewind wasn't possible");
294      return CURLE_SEND_FAIL_REWIND;
295    }
296  }
297  return CURLE_OK;
298}
299
300static int data_pending(const struct connectdata *conn)
301{
302  /* in the case of libssh2, we can never be really sure that we have emptied
303     its internal buffers so we MUST always try until we get EAGAIN back */
304  return conn->handler->protocol&(CURLPROTO_SCP|CURLPROTO_SFTP) ||
305#if defined(USE_NGHTTP2)
306    Curl_ssl_data_pending(conn, FIRSTSOCKET) ||
307    /* For HTTP/2, we may read up everything including responde body
308       with header fields in Curl_http_readwrite_headers. If no
309       content-length is provided, curl waits for the connection
310       close, which we emulate it using conn->proto.httpc.closed =
311       TRUE. The thing is if we read everything, then http2_recv won't
312       be called and we cannot signal the HTTP/2 stream has closed. As
313       a workaround, we return nonzero here to call http2_recv. */
314    ((conn->handler->protocol&PROTO_FAMILY_HTTP) && conn->httpversion == 20);
315#else
316    Curl_ssl_data_pending(conn, FIRSTSOCKET);
317#endif
318}
319
320static void read_rewind(struct connectdata *conn,
321                        size_t thismuch)
322{
323  DEBUGASSERT(conn->read_pos >= thismuch);
324
325  conn->read_pos -= thismuch;
326  conn->bits.stream_was_rewound = TRUE;
327
328#ifdef DEBUGBUILD
329  {
330    char buf[512 + 1];
331    size_t show;
332
333    show = CURLMIN(conn->buf_len - conn->read_pos, sizeof(buf)-1);
334    if(conn->master_buffer) {
335      memcpy(buf, conn->master_buffer + conn->read_pos, show);
336      buf[show] = '\0';
337    }
338    else {
339      buf[0] = '\0';
340    }
341
342    DEBUGF(infof(conn->data,
343                 "Buffer after stream rewind (read_pos = %zu): [%s]\n",
344                 conn->read_pos, buf));
345  }
346#endif
347}
348
349/*
350 * Check to see if CURLOPT_TIMECONDITION was met by comparing the time of the
351 * remote document with the time provided by CURLOPT_TIMEVAL
352 */
353bool Curl_meets_timecondition(struct Curl_easy *data, time_t timeofdoc)
354{
355  if((timeofdoc == 0) || (data->set.timevalue == 0))
356    return TRUE;
357
358  switch(data->set.timecondition) {
359  case CURL_TIMECOND_IFMODSINCE:
360  default:
361    if(timeofdoc <= data->set.timevalue) {
362      infof(data,
363            "The requested document is not new enough\n");
364      data->info.timecond = TRUE;
365      return FALSE;
366    }
367    break;
368  case CURL_TIMECOND_IFUNMODSINCE:
369    if(timeofdoc >= data->set.timevalue) {
370      infof(data,
371            "The requested document is not old enough\n");
372      data->info.timecond = TRUE;
373      return FALSE;
374    }
375    break;
376  }
377
378  return TRUE;
379}
380
381/*
382 * Go ahead and do a read if we have a readable socket or if
383 * the stream was rewound (in which case we have data in a
384 * buffer)
385 *
386 * return '*comeback' TRUE if we didn't properly drain the socket so this
387 * function should get called again without select() or similar in between!
388 */
389static CURLcode readwrite_data(struct Curl_easy *data,
390                               struct connectdata *conn,
391                               struct SingleRequest *k,
392                               int *didwhat, bool *done,
393                               bool *comeback)
394{
395  CURLcode result = CURLE_OK;
396  ssize_t nread; /* number of bytes read */
397  size_t excess = 0; /* excess bytes read */
398  bool is_empty_data = FALSE;
399  bool readmore = FALSE; /* used by RTP to signal for more data */
400  int maxloops = 100;
401
402  *done = FALSE;
403  *comeback = FALSE;
404
405  /* This is where we loop until we have read everything there is to
406     read or we get a CURLE_AGAIN */
407  do {
408    size_t buffersize = data->set.buffer_size?
409      data->set.buffer_size : BUFSIZE;
410    size_t bytestoread = buffersize;
411
412    if(
413#if defined(USE_NGHTTP2)
414       /* For HTTP/2, read data without caring about the content
415          length. This is safe because body in HTTP/2 is always
416          segmented thanks to its framing layer. Meanwhile, we have to
417          call Curl_read to ensure that http2_handle_stream_close is
418          called when we read all incoming bytes for a particular
419          stream. */
420       !((conn->handler->protocol & PROTO_FAMILY_HTTP) &&
421         conn->httpversion == 20) &&
422#endif
423       k->size != -1 && !k->header) {
424      /* make sure we don't read "too much" if we can help it since we
425         might be pipelining and then someone else might want to read what
426         follows! */
427      curl_off_t totalleft = k->size - k->bytecount;
428      if(totalleft < (curl_off_t)bytestoread)
429        bytestoread = (size_t)totalleft;
430    }
431
432    if(bytestoread) {
433      /* receive data from the network! */
434      result = Curl_read(conn, conn->sockfd, k->buf, bytestoread, &nread);
435
436      /* read would've blocked */
437      if(CURLE_AGAIN == result)
438        break; /* get out of loop */
439
440      if(result>0)
441        return result;
442    }
443    else {
444      /* read nothing but since we wanted nothing we consider this an OK
445         situation to proceed from */
446      DEBUGF(infof(data, "readwrite_data: we're done!\n"));
447      nread = 0;
448    }
449
450    if((k->bytecount == 0) && (k->writebytecount == 0)) {
451      Curl_pgrsTime(data, TIMER_STARTTRANSFER);
452      if(k->exp100 > EXP100_SEND_DATA)
453        /* set time stamp to compare with when waiting for the 100 */
454        k->start100 = Curl_tvnow();
455    }
456
457    *didwhat |= KEEP_RECV;
458    /* indicates data of zero size, i.e. empty file */
459    is_empty_data = ((nread == 0) && (k->bodywrites == 0)) ? TRUE : FALSE;
460
461    /* NUL terminate, allowing string ops to be used */
462    if(0 < nread || is_empty_data) {
463      k->buf[nread] = 0;
464    }
465    else if(0 >= nread) {
466      /* if we receive 0 or less here, the server closed the connection
467         and we bail out from this! */
468      DEBUGF(infof(data, "nread <= 0, server closed connection, bailing\n"));
469      k->keepon &= ~KEEP_RECV;
470      break;
471    }
472
473    /* Default buffer to use when we write the buffer, it may be changed
474       in the flow below before the actual storing is done. */
475    k->str = k->buf;
476
477    if(conn->handler->readwrite) {
478      result = conn->handler->readwrite(data, conn, &nread, &readmore);
479      if(result)
480        return result;
481      if(readmore)
482        break;
483    }
484
485#ifndef CURL_DISABLE_HTTP
486    /* Since this is a two-state thing, we check if we are parsing
487       headers at the moment or not. */
488    if(k->header) {
489      /* we are in parse-the-header-mode */
490      bool stop_reading = FALSE;
491      result = Curl_http_readwrite_headers(data, conn, &nread, &stop_reading);
492      if(result)
493        return result;
494
495      if(conn->handler->readwrite &&
496         (k->maxdownload <= 0 && nread > 0)) {
497        result = conn->handler->readwrite(data, conn, &nread, &readmore);
498        if(result)
499          return result;
500        if(readmore)
501          break;
502      }
503
504      if(stop_reading) {
505        /* We've stopped dealing with input, get out of the do-while loop */
506
507        if(nread > 0) {
508          if(Curl_pipeline_wanted(conn->data->multi, CURLPIPE_HTTP1)) {
509            infof(data,
510                  "Rewinding stream by : %zd"
511                  " bytes on url %s (zero-length body)\n",
512                  nread, data->state.path);
513            read_rewind(conn, (size_t)nread);
514          }
515          else {
516            infof(data,
517                  "Excess found in a non pipelined read:"
518                  " excess = %zd"
519                  " url = %s (zero-length body)\n",
520                  nread, data->state.path);
521          }
522        }
523
524        break;
525      }
526    }
527#endif /* CURL_DISABLE_HTTP */
528
529
530    /* This is not an 'else if' since it may be a rest from the header
531       parsing, where the beginning of the buffer is headers and the end
532       is non-headers. */
533    if(k->str && !k->header && (nread > 0 || is_empty_data)) {
534
535      if(data->set.opt_no_body) {
536        /* data arrives although we want none, bail out */
537        streamclose(conn, "ignoring body");
538        *done = TRUE;
539        return CURLE_WEIRD_SERVER_REPLY;
540      }
541
542#ifndef CURL_DISABLE_HTTP
543      if(0 == k->bodywrites && !is_empty_data) {
544        /* These checks are only made the first time we are about to
545           write a piece of the body */
546        if(conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_RTSP)) {
547          /* HTTP-only checks */
548
549          if(data->req.newurl) {
550            if(conn->bits.close) {
551              /* Abort after the headers if "follow Location" is set
552                 and we're set to close anyway. */
553              k->keepon &= ~KEEP_RECV;
554              *done = TRUE;
555              return CURLE_OK;
556            }
557            /* We have a new url to load, but since we want to be able
558               to re-use this connection properly, we read the full
559               response in "ignore more" */
560            k->ignorebody = TRUE;
561            infof(data, "Ignoring the response-body\n");
562          }
563          if(data->state.resume_from && !k->content_range &&
564             (data->set.httpreq==HTTPREQ_GET) &&
565             !k->ignorebody) {
566
567            if(k->size == data->state.resume_from) {
568              /* The resume point is at the end of file, consider this fine
569                 even if it doesn't allow resume from here. */
570              infof(data, "The entire document is already downloaded");
571              connclose(conn, "already downloaded");
572              /* Abort download */
573              k->keepon &= ~KEEP_RECV;
574              *done = TRUE;
575              return CURLE_OK;
576            }
577
578            /* we wanted to resume a download, although the server doesn't
579             * seem to support this and we did this with a GET (if it
580             * wasn't a GET we did a POST or PUT resume) */
581            failf(data, "HTTP server doesn't seem to support "
582                  "byte ranges. Cannot resume.");
583            return CURLE_RANGE_ERROR;
584          }
585
586          if(data->set.timecondition && !data->state.range) {
587            /* A time condition has been set AND no ranges have been
588               requested. This seems to be what chapter 13.3.4 of
589               RFC 2616 defines to be the correct action for a
590               HTTP/1.1 client */
591
592            if(!Curl_meets_timecondition(data, k->timeofdoc)) {
593              *done = TRUE;
594              /* We're simulating a http 304 from server so we return
595                 what should have been returned from the server */
596              data->info.httpcode = 304;
597              infof(data, "Simulate a HTTP 304 response!\n");
598              /* we abort the transfer before it is completed == we ruin the
599                 re-use ability. Close the connection */
600              connclose(conn, "Simulated 304 handling");
601              return CURLE_OK;
602            }
603          } /* we have a time condition */
604
605        } /* this is HTTP or RTSP */
606      } /* this is the first time we write a body part */
607#endif /* CURL_DISABLE_HTTP */
608
609      k->bodywrites++;
610
611      /* pass data to the debug function before it gets "dechunked" */
612      if(data->set.verbose) {
613        if(k->badheader) {
614          Curl_debug(data, CURLINFO_DATA_IN, data->state.headerbuff,
615                     (size_t)k->hbuflen, conn);
616          if(k->badheader == HEADER_PARTHEADER)
617            Curl_debug(data, CURLINFO_DATA_IN,
618                       k->str, (size_t)nread, conn);
619        }
620        else
621          Curl_debug(data, CURLINFO_DATA_IN,
622                     k->str, (size_t)nread, conn);
623      }
624
625#ifndef CURL_DISABLE_HTTP
626      if(k->chunk) {
627        /*
628         * Here comes a chunked transfer flying and we need to decode this
629         * properly.  While the name says read, this function both reads
630         * and writes away the data. The returned 'nread' holds the number
631         * of actual data it wrote to the client.
632         */
633
634        CHUNKcode res =
635          Curl_httpchunk_read(conn, k->str, nread, &nread);
636
637        if(CHUNKE_OK < res) {
638          if(CHUNKE_WRITE_ERROR == res) {
639            failf(data, "Failed writing data");
640            return CURLE_WRITE_ERROR;
641          }
642          failf(data, "%s in chunked-encoding", Curl_chunked_strerror(res));
643          return CURLE_RECV_ERROR;
644        }
645        else if(CHUNKE_STOP == res) {
646          size_t dataleft;
647          /* we're done reading chunks! */
648          k->keepon &= ~KEEP_RECV; /* read no more */
649
650          /* There are now possibly N number of bytes at the end of the
651             str buffer that weren't written to the client.
652
653             We DO care about this data if we are pipelining.
654             Push it back to be read on the next pass. */
655
656          dataleft = conn->chunk.dataleft;
657          if(dataleft != 0) {
658            infof(conn->data, "Leftovers after chunking: %zu bytes\n",
659                  dataleft);
660            if(Curl_pipeline_wanted(conn->data->multi, CURLPIPE_HTTP1)) {
661              /* only attempt the rewind if we truly are pipelining */
662              infof(conn->data, "Rewinding %zu bytes\n",dataleft);
663              read_rewind(conn, dataleft);
664            }
665          }
666        }
667        /* If it returned OK, we just keep going */
668      }
669#endif   /* CURL_DISABLE_HTTP */
670
671      /* Account for body content stored in the header buffer */
672      if(k->badheader && !k->ignorebody) {
673        DEBUGF(infof(data, "Increasing bytecount by %zu from hbuflen\n",
674                     k->hbuflen));
675        k->bytecount += k->hbuflen;
676      }
677
678      if((-1 != k->maxdownload) &&
679         (k->bytecount + nread >= k->maxdownload)) {
680
681        excess = (size_t)(k->bytecount + nread - k->maxdownload);
682        if(excess > 0 && !k->ignorebody) {
683          if(Curl_pipeline_wanted(conn->data->multi, CURLPIPE_HTTP1)) {
684            /* The 'excess' amount below can't be more than BUFSIZE which
685               always will fit in a size_t */
686            infof(data,
687                  "Rewinding stream by : %zu"
688                  " bytes on url %s (size = %" CURL_FORMAT_CURL_OFF_T
689                  ", maxdownload = %" CURL_FORMAT_CURL_OFF_T
690                  ", bytecount = %" CURL_FORMAT_CURL_OFF_T ", nread = %zd)\n",
691                  excess, data->state.path,
692                  k->size, k->maxdownload, k->bytecount, nread);
693            read_rewind(conn, excess);
694          }
695          else {
696            infof(data,
697                  "Excess found in a non pipelined read:"
698                  " excess = %zu"
699                  ", size = %" CURL_FORMAT_CURL_OFF_T
700                  ", maxdownload = %" CURL_FORMAT_CURL_OFF_T
701                  ", bytecount = %" CURL_FORMAT_CURL_OFF_T "\n",
702                  excess, k->size, k->maxdownload, k->bytecount);
703          }
704        }
705
706        nread = (ssize_t) (k->maxdownload - k->bytecount);
707        if(nread < 0) /* this should be unusual */
708          nread = 0;
709
710        k->keepon &= ~KEEP_RECV; /* we're done reading */
711      }
712
713      k->bytecount += nread;
714
715      Curl_pgrsSetDownloadCounter(data, k->bytecount);
716
717      if(!k->chunk && (nread || k->badheader || is_empty_data)) {
718        /* If this is chunky transfer, it was already written */
719
720        if(k->badheader && !k->ignorebody) {
721          /* we parsed a piece of data wrongly assuming it was a header
722             and now we output it as body instead */
723
724          /* Don't let excess data pollute body writes */
725          if(k->maxdownload == -1 || (curl_off_t)k->hbuflen <= k->maxdownload)
726            result = Curl_client_write(conn, CLIENTWRITE_BODY,
727                                       data->state.headerbuff,
728                                       k->hbuflen);
729          else
730            result = Curl_client_write(conn, CLIENTWRITE_BODY,
731                                       data->state.headerbuff,
732                                       (size_t)k->maxdownload);
733
734          if(result)
735            return result;
736        }
737        if(k->badheader < HEADER_ALLBAD) {
738          /* This switch handles various content encodings. If there's an
739             error here, be sure to check over the almost identical code
740             in http_chunks.c.
741             Make sure that ALL_CONTENT_ENCODINGS contains all the
742             encodings handled here. */
743#ifdef HAVE_LIBZ
744          switch (conn->data->set.http_ce_skip ?
745                  IDENTITY : k->auto_decoding) {
746          case IDENTITY:
747#endif
748            /* This is the default when the server sends no
749               Content-Encoding header. See Curl_readwrite_init; the
750               memset() call initializes k->auto_decoding to zero. */
751            if(!k->ignorebody) {
752
753#ifndef CURL_DISABLE_POP3
754              if(conn->handler->protocol&PROTO_FAMILY_POP3)
755                result = Curl_pop3_write(conn, k->str, nread);
756              else
757#endif /* CURL_DISABLE_POP3 */
758
759                result = Curl_client_write(conn, CLIENTWRITE_BODY, k->str,
760                                           nread);
761            }
762#ifdef HAVE_LIBZ
763            break;
764
765          case DEFLATE:
766            /* Assume CLIENTWRITE_BODY; headers are not encoded. */
767            if(!k->ignorebody)
768              result = Curl_unencode_deflate_write(conn, k, nread);
769            break;
770
771          case GZIP:
772            /* Assume CLIENTWRITE_BODY; headers are not encoded. */
773            if(!k->ignorebody)
774              result = Curl_unencode_gzip_write(conn, k, nread);
775            break;
776
777          default:
778            failf (data, "Unrecognized content encoding type. "
779                   "libcurl understands `identity', `deflate' and `gzip' "
780                   "content encodings.");
781            result = CURLE_BAD_CONTENT_ENCODING;
782            break;
783          }
784#endif
785        }
786        k->badheader = HEADER_NORMAL; /* taken care of now */
787
788        if(result)
789          return result;
790      }
791
792    } /* if(!header and data to read) */
793
794    if(conn->handler->readwrite &&
795       (excess > 0 && !conn->bits.stream_was_rewound)) {
796      /* Parse the excess data */
797      k->str += nread;
798      nread = (ssize_t)excess;
799
800      result = conn->handler->readwrite(data, conn, &nread, &readmore);
801      if(result)
802        return result;
803
804      if(readmore)
805        k->keepon |= KEEP_RECV; /* we're not done reading */
806      break;
807    }
808
809    if(is_empty_data) {
810      /* if we received nothing, the server closed the connection and we
811         are done */
812      k->keepon &= ~KEEP_RECV;
813    }
814
815  } while(data_pending(conn) && maxloops--);
816
817  if(maxloops <= 0) {
818    /* we mark it as read-again-please */
819    conn->cselect_bits = CURL_CSELECT_IN;
820    *comeback = TRUE;
821  }
822
823  if(((k->keepon & (KEEP_RECV|KEEP_SEND)) == KEEP_SEND) &&
824     conn->bits.close) {
825    /* When we've read the entire thing and the close bit is set, the server
826       may now close the connection. If there's now any kind of sending going
827       on from our side, we need to stop that immediately. */
828    infof(data, "we are done reading and this is set to close, stop send\n");
829    k->keepon &= ~KEEP_SEND; /* no writing anymore either */
830  }
831
832  return CURLE_OK;
833}
834
835static CURLcode done_sending(struct connectdata *conn,
836                             struct SingleRequest *k)
837{
838  k->keepon &= ~KEEP_SEND; /* we're done writing */
839
840  Curl_http2_done_sending(conn);
841
842  if(conn->bits.rewindaftersend) {
843    CURLcode result = Curl_readrewind(conn);
844    if(result)
845      return result;
846  }
847  return CURLE_OK;
848}
849
850
851/*
852 * Send data to upload to the server, when the socket is writable.
853 */
854static CURLcode readwrite_upload(struct Curl_easy *data,
855                                 struct connectdata *conn,
856                                 struct SingleRequest *k,
857                                 int *didwhat)
858{
859  ssize_t i, si;
860  ssize_t bytes_written;
861  CURLcode result;
862  ssize_t nread; /* number of bytes read */
863  bool sending_http_headers = FALSE;
864
865  if((k->bytecount == 0) && (k->writebytecount == 0))
866    Curl_pgrsTime(data, TIMER_STARTTRANSFER);
867
868  *didwhat |= KEEP_SEND;
869
870  do {
871
872    /* only read more data if there's no upload data already
873       present in the upload buffer */
874    if(0 == data->req.upload_present) {
875      /* init the "upload from here" pointer */
876      data->req.upload_fromhere = k->uploadbuf;
877
878      if(!k->upload_done) {
879        /* HTTP pollution, this should be written nicer to become more
880           protocol agnostic. */
881        int fillcount;
882        struct HTTP *http = data->req.protop;
883
884        if((k->exp100 == EXP100_SENDING_REQUEST) &&
885           (http->sending == HTTPSEND_BODY)) {
886          /* If this call is to send body data, we must take some action:
887             We have sent off the full HTTP 1.1 request, and we shall now
888             go into the Expect: 100 state and await such a header */
889          k->exp100 = EXP100_AWAITING_CONTINUE; /* wait for the header */
890          k->keepon &= ~KEEP_SEND;         /* disable writing */
891          k->start100 = Curl_tvnow();       /* timeout count starts now */
892          *didwhat &= ~KEEP_SEND;  /* we didn't write anything actually */
893
894          /* set a timeout for the multi interface */
895          Curl_expire(data, data->set.expect_100_timeout);
896          break;
897        }
898
899        if(conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_RTSP)) {
900          if(http->sending == HTTPSEND_REQUEST)
901            /* We're sending the HTTP request headers, not the data.
902               Remember that so we don't change the line endings. */
903            sending_http_headers = TRUE;
904          else
905            sending_http_headers = FALSE;
906        }
907
908        result = Curl_fillreadbuffer(conn, BUFSIZE, &fillcount);
909        if(result)
910          return result;
911
912        nread = (ssize_t)fillcount;
913      }
914      else
915        nread = 0; /* we're done uploading/reading */
916
917      if(!nread && (k->keepon & KEEP_SEND_PAUSE)) {
918        /* this is a paused transfer */
919        break;
920      }
921      else if(nread<=0) {
922        result = done_sending(conn, k);
923        if(result)
924          return result;
925        break;
926      }
927
928      /* store number of bytes available for upload */
929      data->req.upload_present = nread;
930
931      /* convert LF to CRLF if so asked */
932      if((!sending_http_headers) && (
933#ifdef CURL_DO_LINEEND_CONV
934         /* always convert if we're FTPing in ASCII mode */
935         (data->set.prefer_ascii) ||
936#endif
937         (data->set.crlf))) {
938        /* Do we need to allocate a scratch buffer? */
939        if(!data->state.scratch) {
940          data->state.scratch = malloc(2 * BUFSIZE);
941          if(!data->state.scratch) {
942            failf(data, "Failed to alloc scratch buffer!");
943
944            return CURLE_OUT_OF_MEMORY;
945          }
946        }
947
948        /*
949         * ASCII/EBCDIC Note: This is presumably a text (not binary)
950         * transfer so the data should already be in ASCII.
951         * That means the hex values for ASCII CR (0x0d) & LF (0x0a)
952         * must be used instead of the escape sequences \r & \n.
953         */
954        for(i = 0, si = 0; i < nread; i++, si++) {
955          if(data->req.upload_fromhere[i] == 0x0a) {
956            data->state.scratch[si++] = 0x0d;
957            data->state.scratch[si] = 0x0a;
958            if(!data->set.crlf) {
959              /* we're here only because FTP is in ASCII mode...
960                 bump infilesize for the LF we just added */
961              if(data->state.infilesize != -1)
962                data->state.infilesize++;
963            }
964          }
965          else
966            data->state.scratch[si] = data->req.upload_fromhere[i];
967        }
968
969        if(si != nread) {
970          /* only perform the special operation if we really did replace
971             anything */
972          nread = si;
973
974          /* upload from the new (replaced) buffer instead */
975          data->req.upload_fromhere = data->state.scratch;
976
977          /* set the new amount too */
978          data->req.upload_present = nread;
979        }
980      }
981
982#ifndef CURL_DISABLE_SMTP
983      if(conn->handler->protocol & PROTO_FAMILY_SMTP) {
984        result = Curl_smtp_escape_eob(conn, nread);
985        if(result)
986          return result;
987      }
988#endif /* CURL_DISABLE_SMTP */
989    } /* if 0 == data->req.upload_present */
990    else {
991      /* We have a partial buffer left from a previous "round". Use
992         that instead of reading more data */
993    }
994
995    /* write to socket (send away data) */
996    result = Curl_write(conn,
997                        conn->writesockfd,     /* socket to send to */
998                        data->req.upload_fromhere, /* buffer pointer */
999                        data->req.upload_present,  /* buffer size */
1000                        &bytes_written);           /* actually sent */
1001
1002    if(result)
1003      return result;
1004
1005    if(data->set.verbose)
1006      /* show the data before we change the pointer upload_fromhere */
1007      Curl_debug(data, CURLINFO_DATA_OUT, data->req.upload_fromhere,
1008                 (size_t)bytes_written, conn);
1009
1010    k->writebytecount += bytes_written;
1011
1012    if(k->writebytecount == data->state.infilesize) {
1013      /* we have sent all data we were supposed to */
1014      k->upload_done = TRUE;
1015      infof(data, "We are completely uploaded and fine\n");
1016    }
1017
1018    if(data->req.upload_present != bytes_written) {
1019      /* we only wrote a part of the buffer (if anything), deal with it! */
1020
1021      /* store the amount of bytes left in the buffer to write */
1022      data->req.upload_present -= bytes_written;
1023
1024      /* advance the pointer where to find the buffer when the next send
1025         is to happen */
1026      data->req.upload_fromhere += bytes_written;
1027    }
1028    else {
1029      /* we've uploaded that buffer now */
1030      data->req.upload_fromhere = k->uploadbuf;
1031      data->req.upload_present = 0; /* no more bytes left */
1032
1033      if(k->upload_done) {
1034        result = done_sending(conn, k);
1035        if(result)
1036          return result;
1037      }
1038    }
1039
1040    Curl_pgrsSetUploadCounter(data, k->writebytecount);
1041
1042  } WHILE_FALSE; /* just to break out from! */
1043
1044  return CURLE_OK;
1045}
1046
1047/*
1048 * Curl_readwrite() is the low-level function to be called when data is to
1049 * be read and written to/from the connection.
1050 *
1051 * return '*comeback' TRUE if we didn't properly drain the socket so this
1052 * function should get called again without select() or similar in between!
1053 */
1054CURLcode Curl_readwrite(struct connectdata *conn,
1055                        struct Curl_easy *data,
1056                        bool *done,
1057                        bool *comeback)
1058{
1059  struct SingleRequest *k = &data->req;
1060  CURLcode result;
1061  int didwhat=0;
1062
1063  curl_socket_t fd_read;
1064  curl_socket_t fd_write;
1065  int select_res = conn->cselect_bits;
1066
1067  conn->cselect_bits = 0;
1068
1069  /* only use the proper socket if the *_HOLD bit is not set simultaneously as
1070     then we are in rate limiting state in that transfer direction */
1071
1072  if((k->keepon & KEEP_RECVBITS) == KEEP_RECV)
1073    fd_read = conn->sockfd;
1074  else
1075    fd_read = CURL_SOCKET_BAD;
1076
1077  if((k->keepon & KEEP_SENDBITS) == KEEP_SEND)
1078    fd_write = conn->writesockfd;
1079  else
1080    fd_write = CURL_SOCKET_BAD;
1081
1082  if(conn->data->state.drain) {
1083    select_res |= CURL_CSELECT_IN;
1084    DEBUGF(infof(data, "Curl_readwrite: forcibly told to drain data\n"));
1085  }
1086
1087  if(!select_res) /* Call for select()/poll() only, if read/write/error
1088                     status is not known. */
1089    select_res = Curl_socket_check(fd_read, CURL_SOCKET_BAD, fd_write, 0);
1090
1091  if(select_res == CURL_CSELECT_ERR) {
1092    failf(data, "select/poll returned error");
1093    return CURLE_SEND_ERROR;
1094  }
1095
1096  /* We go ahead and do a read if we have a readable socket or if
1097     the stream was rewound (in which case we have data in a
1098     buffer) */
1099  if((k->keepon & KEEP_RECV) &&
1100     ((select_res & CURL_CSELECT_IN) || conn->bits.stream_was_rewound)) {
1101
1102    result = readwrite_data(data, conn, k, &didwhat, done, comeback);
1103    if(result || *done)
1104      return result;
1105  }
1106
1107  /* If we still have writing to do, we check if we have a writable socket. */
1108  if((k->keepon & KEEP_SEND) && (select_res & CURL_CSELECT_OUT)) {
1109    /* write */
1110
1111    result = readwrite_upload(data, conn, k, &didwhat);
1112    if(result)
1113      return result;
1114  }
1115
1116  k->now = Curl_tvnow();
1117  if(didwhat) {
1118    /* Update read/write counters */
1119    if(k->bytecountp)
1120      *k->bytecountp = k->bytecount; /* read count */
1121    if(k->writebytecountp)
1122      *k->writebytecountp = k->writebytecount; /* write count */
1123  }
1124  else {
1125    /* no read no write, this is a timeout? */
1126    if(k->exp100 == EXP100_AWAITING_CONTINUE) {
1127      /* This should allow some time for the header to arrive, but only a
1128         very short time as otherwise it'll be too much wasted time too
1129         often. */
1130
1131      /* Quoting RFC2616, section "8.2.3 Use of the 100 (Continue) Status":
1132
1133         Therefore, when a client sends this header field to an origin server
1134         (possibly via a proxy) from which it has never seen a 100 (Continue)
1135         status, the client SHOULD NOT wait for an indefinite period before
1136         sending the request body.
1137
1138      */
1139
1140      time_t ms = Curl_tvdiff(k->now, k->start100);
1141      if(ms >= data->set.expect_100_timeout) {
1142        /* we've waited long enough, continue anyway */
1143        k->exp100 = EXP100_SEND_DATA;
1144        k->keepon |= KEEP_SEND;
1145        infof(data, "Done waiting for 100-continue\n");
1146      }
1147    }
1148  }
1149
1150  if(Curl_pgrsUpdate(conn))
1151    result = CURLE_ABORTED_BY_CALLBACK;
1152  else
1153    result = Curl_speedcheck(data, k->now);
1154  if(result)
1155    return result;
1156
1157  if(k->keepon) {
1158    if(0 > Curl_timeleft(data, &k->now, FALSE)) {
1159      if(k->size != -1) {
1160        failf(data, "Operation timed out after %ld milliseconds with %"
1161              CURL_FORMAT_CURL_OFF_T " out of %"
1162              CURL_FORMAT_CURL_OFF_T " bytes received",
1163              Curl_tvdiff(k->now, data->progress.t_startsingle), k->bytecount,
1164              k->size);
1165      }
1166      else {
1167        failf(data, "Operation timed out after %ld milliseconds with %"
1168              CURL_FORMAT_CURL_OFF_T " bytes received",
1169              Curl_tvdiff(k->now, data->progress.t_startsingle), k->bytecount);
1170      }
1171      return CURLE_OPERATION_TIMEDOUT;
1172    }
1173  }
1174  else {
1175    /*
1176     * The transfer has been performed. Just make some general checks before
1177     * returning.
1178     */
1179
1180    if(!(data->set.opt_no_body) && (k->size != -1) &&
1181       (k->bytecount != k->size) &&
1182#ifdef CURL_DO_LINEEND_CONV
1183       /* Most FTP servers don't adjust their file SIZE response for CRLFs,
1184          so we'll check to see if the discrepancy can be explained
1185          by the number of CRLFs we've changed to LFs.
1186       */
1187       (k->bytecount != (k->size + data->state.crlf_conversions)) &&
1188#endif /* CURL_DO_LINEEND_CONV */
1189       !data->req.newurl) {
1190      failf(data, "transfer closed with %" CURL_FORMAT_CURL_OFF_T
1191            " bytes remaining to read",
1192            k->size - k->bytecount);
1193      return CURLE_PARTIAL_FILE;
1194    }
1195    else if(!(data->set.opt_no_body) &&
1196            k->chunk &&
1197            (conn->chunk.state != CHUNK_STOP)) {
1198      /*
1199       * In chunked mode, return an error if the connection is closed prior to
1200       * the empty (terminating) chunk is read.
1201       *
1202       * The condition above used to check for
1203       * conn->proto.http->chunk.datasize != 0 which is true after reading
1204       * *any* chunk, not just the empty chunk.
1205       *
1206       */
1207      failf(data, "transfer closed with outstanding read data remaining");
1208      return CURLE_PARTIAL_FILE;
1209    }
1210    if(Curl_pgrsUpdate(conn))
1211      return CURLE_ABORTED_BY_CALLBACK;
1212  }
1213
1214  /* Now update the "done" boolean we return */
1215  *done = (0 == (k->keepon&(KEEP_RECV|KEEP_SEND|
1216                            KEEP_RECV_PAUSE|KEEP_SEND_PAUSE))) ? TRUE : FALSE;
1217
1218  return CURLE_OK;
1219}
1220
1221/*
1222 * Curl_single_getsock() gets called by the multi interface code when the app
1223 * has requested to get the sockets for the current connection. This function
1224 * will then be called once for every connection that the multi interface
1225 * keeps track of. This function will only be called for connections that are
1226 * in the proper state to have this information available.
1227 */
1228int Curl_single_getsock(const struct connectdata *conn,
1229                        curl_socket_t *sock, /* points to numsocks number
1230                                                of sockets */
1231                        int numsocks)
1232{
1233  const struct Curl_easy *data = conn->data;
1234  int bitmap = GETSOCK_BLANK;
1235  unsigned sockindex = 0;
1236
1237  if(conn->handler->perform_getsock)
1238    return conn->handler->perform_getsock(conn, sock, numsocks);
1239
1240  if(numsocks < 2)
1241    /* simple check but we might need two slots */
1242    return GETSOCK_BLANK;
1243
1244  /* don't include HOLD and PAUSE connections */
1245  if((data->req.keepon & KEEP_RECVBITS) == KEEP_RECV) {
1246
1247    DEBUGASSERT(conn->sockfd != CURL_SOCKET_BAD);
1248
1249    bitmap |= GETSOCK_READSOCK(sockindex);
1250    sock[sockindex] = conn->sockfd;
1251  }
1252
1253  /* don't include HOLD and PAUSE connections */
1254  if((data->req.keepon & KEEP_SENDBITS) == KEEP_SEND) {
1255
1256    if((conn->sockfd != conn->writesockfd) ||
1257       bitmap == GETSOCK_BLANK) {
1258      /* only if they are not the same socket and we have a readable
1259         one, we increase index */
1260      if(bitmap != GETSOCK_BLANK)
1261        sockindex++; /* increase index if we need two entries */
1262
1263      DEBUGASSERT(conn->writesockfd != CURL_SOCKET_BAD);
1264
1265      sock[sockindex] = conn->writesockfd;
1266    }
1267
1268    bitmap |= GETSOCK_WRITESOCK(sockindex);
1269  }
1270
1271  return bitmap;
1272}
1273
1274/* Curl_init_CONNECT() gets called each time the handle switches to CONNECT
1275   which means this gets called once for each subsequent redirect etc */
1276void Curl_init_CONNECT(struct Curl_easy *data)
1277{
1278  data->state.fread_func = data->set.fread_func_set;
1279  data->state.in = data->set.in_set;
1280}
1281
1282/*
1283 * Curl_pretransfer() is called immediately before a transfer starts, and only
1284 * once for one transfer no matter if it has redirects or do multi-pass
1285 * authentication etc.
1286 */
1287CURLcode Curl_pretransfer(struct Curl_easy *data)
1288{
1289  CURLcode result;
1290  if(!data->change.url) {
1291    /* we can't do anything without URL */
1292    failf(data, "No URL set!");
1293    return CURLE_URL_MALFORMAT;
1294  }
1295
1296  /* Init the SSL session ID cache here. We do it here since we want to do it
1297     after the *_setopt() calls (that could specify the size of the cache) but
1298     before any transfer takes place. */
1299  result = Curl_ssl_initsessions(data, data->set.general_ssl.max_ssl_sessions);
1300  if(result)
1301    return result;
1302
1303  data->set.followlocation=0; /* reset the location-follow counter */
1304  data->state.this_is_a_follow = FALSE; /* reset this */
1305  data->state.errorbuf = FALSE; /* no error has occurred */
1306  data->state.httpversion = 0; /* don't assume any particular server version */
1307
1308  data->state.authproblem = FALSE;
1309  data->state.authhost.want = data->set.httpauth;
1310  data->state.authproxy.want = data->set.proxyauth;
1311  Curl_safefree(data->info.wouldredirect);
1312  data->info.wouldredirect = NULL;
1313
1314  if(data->set.httpreq == HTTPREQ_PUT)
1315    data->state.infilesize = data->set.filesize;
1316  else
1317    data->state.infilesize = data->set.postfieldsize;
1318
1319  /* If there is a list of cookie files to read, do it now! */
1320  if(data->change.cookielist)
1321    Curl_cookie_loadfiles(data);
1322
1323  /* If there is a list of host pairs to deal with */
1324  if(data->change.resolve)
1325    result = Curl_loadhostpairs(data);
1326
1327  if(!result) {
1328    /* Allow data->set.use_port to set which port to use. This needs to be
1329     * disabled for example when we follow Location: headers to URLs using
1330     * different ports! */
1331    data->state.allow_port = TRUE;
1332
1333#if defined(HAVE_SIGNAL) && defined(SIGPIPE) && !defined(HAVE_MSG_NOSIGNAL)
1334    /*************************************************************
1335     * Tell signal handler to ignore SIGPIPE
1336     *************************************************************/
1337    if(!data->set.no_signal)
1338      data->state.prev_signal = signal(SIGPIPE, SIG_IGN);
1339#endif
1340
1341    Curl_initinfo(data); /* reset session-specific information "variables" */
1342    Curl_pgrsResetTimesSizes(data);
1343    Curl_pgrsStartNow(data);
1344
1345    if(data->set.timeout)
1346      Curl_expire(data, data->set.timeout);
1347
1348    if(data->set.connecttimeout)
1349      Curl_expire(data, data->set.connecttimeout);
1350
1351    /* In case the handle is re-used and an authentication method was picked
1352       in the session we need to make sure we only use the one(s) we now
1353       consider to be fine */
1354    data->state.authhost.picked &= data->state.authhost.want;
1355    data->state.authproxy.picked &= data->state.authproxy.want;
1356
1357    if(data->set.wildcardmatch) {
1358      struct WildcardData *wc = &data->wildcard;
1359      if(!wc->filelist) {
1360        result = Curl_wildcard_init(wc); /* init wildcard structures */
1361        if(result)
1362          return CURLE_OUT_OF_MEMORY;
1363      }
1364    }
1365
1366  }
1367
1368  return result;
1369}
1370
1371/*
1372 * Curl_posttransfer() is called immediately after a transfer ends
1373 */
1374CURLcode Curl_posttransfer(struct Curl_easy *data)
1375{
1376#if defined(HAVE_SIGNAL) && defined(SIGPIPE) && !defined(HAVE_MSG_NOSIGNAL)
1377  /* restore the signal handler for SIGPIPE before we get back */
1378  if(!data->set.no_signal)
1379    signal(SIGPIPE, data->state.prev_signal);
1380#else
1381  (void)data; /* unused parameter */
1382#endif
1383
1384  return CURLE_OK;
1385}
1386
1387#ifndef CURL_DISABLE_HTTP
1388/*
1389 * strlen_url() returns the length of the given URL if the spaces within the
1390 * URL were properly URL encoded.
1391 */
1392static size_t strlen_url(const char *url)
1393{
1394  const unsigned char *ptr;
1395  size_t newlen=0;
1396  bool left=TRUE; /* left side of the ? */
1397
1398  for(ptr=(unsigned char *)url; *ptr; ptr++) {
1399    switch(*ptr) {
1400    case '?':
1401      left=FALSE;
1402      /* fall through */
1403    default:
1404      if(*ptr >= 0x80)
1405        newlen += 2;
1406      newlen++;
1407      break;
1408    case ' ':
1409      if(left)
1410        newlen+=3;
1411      else
1412        newlen++;
1413      break;
1414    }
1415  }
1416  return newlen;
1417}
1418
1419/* strcpy_url() copies a url to a output buffer and URL-encodes the spaces in
1420 * the source URL accordingly.
1421 */
1422static void strcpy_url(char *output, const char *url)
1423{
1424  /* we must add this with whitespace-replacing */
1425  bool left=TRUE;
1426  const unsigned char *iptr;
1427  char *optr = output;
1428  for(iptr = (unsigned char *)url;    /* read from here */
1429      *iptr;         /* until zero byte */
1430      iptr++) {
1431    switch(*iptr) {
1432    case '?':
1433      left=FALSE;
1434      /* fall through */
1435    default:
1436      if(*iptr >= 0x80) {
1437        snprintf(optr, 4, "%%%02x", *iptr);
1438        optr += 3;
1439      }
1440      else
1441        *optr++=*iptr;
1442      break;
1443    case ' ':
1444      if(left) {
1445        *optr++='%'; /* add a '%' */
1446        *optr++='2'; /* add a '2' */
1447        *optr++='0'; /* add a '0' */
1448      }
1449      else
1450        *optr++='+'; /* add a '+' here */
1451      break;
1452    }
1453  }
1454  *optr=0; /* zero terminate output buffer */
1455
1456}
1457
1458/*
1459 * Returns true if the given URL is absolute (as opposed to relative)
1460 */
1461static bool is_absolute_url(const char *url)
1462{
1463  char prot[16]; /* URL protocol string storage */
1464  char letter;   /* used for a silly sscanf */
1465
1466  return (2 == sscanf(url, "%15[^?&/:]://%c", prot, &letter)) ? TRUE : FALSE;
1467}
1468
1469/*
1470 * Concatenate a relative URL to a base URL making it absolute.
1471 * URL-encodes any spaces.
1472 * The returned pointer must be freed by the caller unless NULL
1473 * (returns NULL on out of memory).
1474 */
1475static char *concat_url(const char *base, const char *relurl)
1476{
1477  /***
1478   TRY to append this new path to the old URL
1479   to the right of the host part. Oh crap, this is doomed to cause
1480   problems in the future...
1481  */
1482  char *newest;
1483  char *protsep;
1484  char *pathsep;
1485  size_t newlen;
1486
1487  const char *useurl = relurl;
1488  size_t urllen;
1489
1490  /* we must make our own copy of the URL to play with, as it may
1491     point to read-only data */
1492  char *url_clone=strdup(base);
1493
1494  if(!url_clone)
1495    return NULL; /* skip out of this NOW */
1496
1497  /* protsep points to the start of the host name */
1498  protsep=strstr(url_clone, "//");
1499  if(!protsep)
1500    protsep=url_clone;
1501  else
1502    protsep+=2; /* pass the slashes */
1503
1504  if('/' != relurl[0]) {
1505    int level=0;
1506
1507    /* First we need to find out if there's a ?-letter in the URL,
1508       and cut it and the right-side of that off */
1509    pathsep = strchr(protsep, '?');
1510    if(pathsep)
1511      *pathsep=0;
1512
1513    /* we have a relative path to append to the last slash if there's one
1514       available, or if the new URL is just a query string (starts with a
1515       '?')  we append the new one at the end of the entire currently worked
1516       out URL */
1517    if(useurl[0] != '?') {
1518      pathsep = strrchr(protsep, '/');
1519      if(pathsep)
1520        *pathsep=0;
1521    }
1522
1523    /* Check if there's any slash after the host name, and if so, remember
1524       that position instead */
1525    pathsep = strchr(protsep, '/');
1526    if(pathsep)
1527      protsep = pathsep+1;
1528    else
1529      protsep = NULL;
1530
1531    /* now deal with one "./" or any amount of "../" in the newurl
1532       and act accordingly */
1533
1534    if((useurl[0] == '.') && (useurl[1] == '/'))
1535      useurl+=2; /* just skip the "./" */
1536
1537    while((useurl[0] == '.') &&
1538          (useurl[1] == '.') &&
1539          (useurl[2] == '/')) {
1540      level++;
1541      useurl+=3; /* pass the "../" */
1542    }
1543
1544    if(protsep) {
1545      while(level--) {
1546        /* cut off one more level from the right of the original URL */
1547        pathsep = strrchr(protsep, '/');
1548        if(pathsep)
1549          *pathsep=0;
1550        else {
1551          *protsep=0;
1552          break;
1553        }
1554      }
1555    }
1556  }
1557  else {
1558    /* We got a new absolute path for this server */
1559
1560    if((relurl[0] == '/') && (relurl[1] == '/')) {
1561      /* the new URL starts with //, just keep the protocol part from the
1562         original one */
1563      *protsep=0;
1564      useurl = &relurl[2]; /* we keep the slashes from the original, so we
1565                              skip the new ones */
1566    }
1567    else {
1568      /* cut off the original URL from the first slash, or deal with URLs
1569         without slash */
1570      pathsep = strchr(protsep, '/');
1571      if(pathsep) {
1572        /* When people use badly formatted URLs, such as
1573           "http://www.url.com?dir=/home/daniel" we must not use the first
1574           slash, if there's a ?-letter before it! */
1575        char *sep = strchr(protsep, '?');
1576        if(sep && (sep < pathsep))
1577          pathsep = sep;
1578        *pathsep=0;
1579      }
1580      else {
1581        /* There was no slash. Now, since we might be operating on a badly
1582           formatted URL, such as "http://www.url.com?id=2380" which doesn't
1583           use a slash separator as it is supposed to, we need to check for a
1584           ?-letter as well! */
1585        pathsep = strchr(protsep, '?');
1586        if(pathsep)
1587          *pathsep=0;
1588      }
1589    }
1590  }
1591
1592  /* If the new part contains a space, this is a mighty stupid redirect
1593     but we still make an effort to do "right". To the left of a '?'
1594     letter we replace each space with %20 while it is replaced with '+'
1595     on the right side of the '?' letter.
1596  */
1597  newlen = strlen_url(useurl);
1598
1599  urllen = strlen(url_clone);
1600
1601  newest = malloc(urllen + 1 + /* possible slash */
1602                  newlen + 1 /* zero byte */);
1603
1604  if(!newest) {
1605    free(url_clone); /* don't leak this */
1606    return NULL;
1607  }
1608
1609  /* copy over the root url part */
1610  memcpy(newest, url_clone, urllen);
1611
1612  /* check if we need to append a slash */
1613  if(('/' == useurl[0]) || (protsep && !*protsep) || ('?' == useurl[0]))
1614    ;
1615  else
1616    newest[urllen++]='/';
1617
1618  /* then append the new piece on the right side */
1619  strcpy_url(&newest[urllen], useurl);
1620
1621  free(url_clone);
1622
1623  return newest;
1624}
1625#endif /* CURL_DISABLE_HTTP */
1626
1627/*
1628 * Curl_follow() handles the URL redirect magic. Pass in the 'newurl' string
1629 * as given by the remote server and set up the new URL to request.
1630 */
1631CURLcode Curl_follow(struct Curl_easy *data,
1632                     char *newurl, /* this 'newurl' is the Location: string,
1633                                      and it must be malloc()ed before passed
1634                                      here */
1635                     followtype type) /* see transfer.h */
1636{
1637#ifdef CURL_DISABLE_HTTP
1638  (void)data;
1639  (void)newurl;
1640  (void)type;
1641  /* Location: following will not happen when HTTP is disabled */
1642  return CURLE_TOO_MANY_REDIRECTS;
1643#else
1644
1645  /* Location: redirect */
1646  bool disallowport = FALSE;
1647
1648  if(type == FOLLOW_REDIR) {
1649    if((data->set.maxredirs != -1) &&
1650        (data->set.followlocation >= data->set.maxredirs)) {
1651      failf(data, "Maximum (%ld) redirects followed", data->set.maxredirs);
1652      return CURLE_TOO_MANY_REDIRECTS;
1653    }
1654
1655    /* mark the next request as a followed location: */
1656    data->state.this_is_a_follow = TRUE;
1657
1658    data->set.followlocation++; /* count location-followers */
1659
1660    if(data->set.http_auto_referer) {
1661      /* We are asked to automatically set the previous URL as the referer
1662         when we get the next URL. We pick the ->url field, which may or may
1663         not be 100% correct */
1664
1665      if(data->change.referer_alloc) {
1666        Curl_safefree(data->change.referer);
1667        data->change.referer_alloc = FALSE;
1668      }
1669
1670      data->change.referer = strdup(data->change.url);
1671      if(!data->change.referer)
1672        return CURLE_OUT_OF_MEMORY;
1673      data->change.referer_alloc = TRUE; /* yes, free this later */
1674    }
1675  }
1676
1677  if(!is_absolute_url(newurl))  {
1678    /***
1679     *DANG* this is an RFC 2068 violation. The URL is supposed
1680     to be absolute and this doesn't seem to be that!
1681     */
1682    char *absolute = concat_url(data->change.url, newurl);
1683    if(!absolute)
1684      return CURLE_OUT_OF_MEMORY;
1685    free(newurl);
1686    newurl = absolute;
1687  }
1688  else {
1689    /* The new URL MAY contain space or high byte values, that means a mighty
1690       stupid redirect URL but we still make an effort to do "right". */
1691    char *newest;
1692    size_t newlen = strlen_url(newurl);
1693
1694    /* This is an absolute URL, don't allow the custom port number */
1695    disallowport = TRUE;
1696
1697    newest = malloc(newlen+1); /* get memory for this */
1698    if(!newest)
1699      return CURLE_OUT_OF_MEMORY;
1700    strcpy_url(newest, newurl); /* create a space-free URL */
1701
1702    free(newurl); /* that was no good */
1703    newurl = newest; /* use this instead now */
1704
1705  }
1706
1707  if(type == FOLLOW_FAKE) {
1708    /* we're only figuring out the new url if we would've followed locations
1709       but now we're done so we can get out! */
1710    data->info.wouldredirect = newurl;
1711    return CURLE_OK;
1712  }
1713
1714  if(disallowport)
1715    data->state.allow_port = FALSE;
1716
1717  if(data->change.url_alloc) {
1718    Curl_safefree(data->change.url);
1719    data->change.url_alloc = FALSE;
1720  }
1721
1722  data->change.url = newurl;
1723  data->change.url_alloc = TRUE;
1724  newurl = NULL; /* don't free! */
1725
1726  infof(data, "Issue another request to this URL: '%s'\n", data->change.url);
1727
1728  /*
1729   * We get here when the HTTP code is 300-399 (and 401). We need to perform
1730   * differently based on exactly what return code there was.
1731   *
1732   * News from 7.10.6: we can also get here on a 401 or 407, in case we act on
1733   * a HTTP (proxy-) authentication scheme other than Basic.
1734   */
1735  switch(data->info.httpcode) {
1736    /* 401 - Act on a WWW-Authenticate, we keep on moving and do the
1737       Authorization: XXXX header in the HTTP request code snippet */
1738    /* 407 - Act on a Proxy-Authenticate, we keep on moving and do the
1739       Proxy-Authorization: XXXX header in the HTTP request code snippet */
1740    /* 300 - Multiple Choices */
1741    /* 306 - Not used */
1742    /* 307 - Temporary Redirect */
1743  default:  /* for all above (and the unknown ones) */
1744    /* Some codes are explicitly mentioned since I've checked RFC2616 and they
1745     * seem to be OK to POST to.
1746     */
1747    break;
1748  case 301: /* Moved Permanently */
1749    /* (quote from RFC7231, section 6.4.2)
1750     *
1751     * Note: For historical reasons, a user agent MAY change the request
1752     * method from POST to GET for the subsequent request.  If this
1753     * behavior is undesired, the 307 (Temporary Redirect) status code
1754     * can be used instead.
1755     *
1756     * ----
1757     *
1758     * Many webservers expect this, so these servers often answers to a POST
1759     * request with an error page. To be sure that libcurl gets the page that
1760     * most user agents would get, libcurl has to force GET.
1761     *
1762     * This behaviour is forbidden by RFC1945 and the obsolete RFC2616, and
1763     * can be overridden with CURLOPT_POSTREDIR.
1764     */
1765    if((data->set.httpreq == HTTPREQ_POST
1766        || data->set.httpreq == HTTPREQ_POST_FORM)
1767       && !(data->set.keep_post & CURL_REDIR_POST_301)) {
1768      infof(data, "Switch from POST to GET\n");
1769      data->set.httpreq = HTTPREQ_GET;
1770    }
1771    break;
1772  case 302: /* Found */
1773    /* (quote from RFC7231, section 6.4.3)
1774     *
1775     * Note: For historical reasons, a user agent MAY change the request
1776     * method from POST to GET for the subsequent request.  If this
1777     * behavior is undesired, the 307 (Temporary Redirect) status code
1778     * can be used instead.
1779     *
1780     * ----
1781     *
1782     * Many webservers expect this, so these servers often answers to a POST
1783     * request with an error page. To be sure that libcurl gets the page that
1784     * most user agents would get, libcurl has to force GET.
1785     *
1786     * This behaviour is forbidden by RFC1945 and the obsolete RFC2616, and
1787     * can be overridden with CURLOPT_POSTREDIR.
1788     */
1789    if((data->set.httpreq == HTTPREQ_POST
1790        || data->set.httpreq == HTTPREQ_POST_FORM)
1791       && !(data->set.keep_post & CURL_REDIR_POST_302)) {
1792      infof(data, "Switch from POST to GET\n");
1793      data->set.httpreq = HTTPREQ_GET;
1794    }
1795    break;
1796
1797  case 303: /* See Other */
1798    /* Disable both types of POSTs, unless the user explicitely
1799       asks for POST after POST */
1800    if(data->set.httpreq != HTTPREQ_GET
1801      && !(data->set.keep_post & CURL_REDIR_POST_303)) {
1802      data->set.httpreq = HTTPREQ_GET; /* enforce GET request */
1803      infof(data, "Disables POST, goes with %s\n",
1804            data->set.opt_no_body?"HEAD":"GET");
1805    }
1806    break;
1807  case 304: /* Not Modified */
1808    /* 304 means we did a conditional request and it was "Not modified".
1809     * We shouldn't get any Location: header in this response!
1810     */
1811    break;
1812  case 305: /* Use Proxy */
1813    /* (quote from RFC2616, section 10.3.6):
1814     * "The requested resource MUST be accessed through the proxy given
1815     * by the Location field. The Location field gives the URI of the
1816     * proxy.  The recipient is expected to repeat this single request
1817     * via the proxy. 305 responses MUST only be generated by origin
1818     * servers."
1819     */
1820    break;
1821  }
1822  Curl_pgrsTime(data, TIMER_REDIRECT);
1823  Curl_pgrsResetTimesSizes(data);
1824
1825  return CURLE_OK;
1826#endif /* CURL_DISABLE_HTTP */
1827}
1828
1829/* Returns CURLE_OK *and* sets '*url' if a request retry is wanted.
1830
1831   NOTE: that the *url is malloc()ed. */
1832CURLcode Curl_retry_request(struct connectdata *conn,
1833                            char **url)
1834{
1835  struct Curl_easy *data = conn->data;
1836
1837  *url = NULL;
1838
1839  /* if we're talking upload, we can't do the checks below, unless the protocol
1840     is HTTP as when uploading over HTTP we will still get a response */
1841  if(data->set.upload &&
1842     !(conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_RTSP)))
1843    return CURLE_OK;
1844
1845  if((data->req.bytecount + data->req.headerbytecount == 0) &&
1846     conn->bits.reuse &&
1847     (data->set.rtspreq != RTSPREQ_RECEIVE)) {
1848    /* We didn't get a single byte when we attempted to re-use a
1849       connection. This might happen if the connection was left alive when we
1850       were done using it before, but that was closed when we wanted to use it
1851       again. Bad luck. Retry the same request on a fresh connect! */
1852    infof(conn->data, "Connection died, retrying a fresh connect\n");
1853    *url = strdup(conn->data->change.url);
1854    if(!*url)
1855      return CURLE_OUT_OF_MEMORY;
1856
1857    connclose(conn, "retry"); /* close this connection */
1858    conn->bits.retry = TRUE; /* mark this as a connection we're about
1859                                to retry. Marking it this way should
1860                                prevent i.e HTTP transfers to return
1861                                error just because nothing has been
1862                                transferred! */
1863
1864
1865    if(conn->handler->protocol&PROTO_FAMILY_HTTP) {
1866      struct HTTP *http = data->req.protop;
1867      if(http->writebytecount)
1868        return Curl_readrewind(conn);
1869    }
1870  }
1871  return CURLE_OK;
1872}
1873
1874/*
1875 * Curl_setup_transfer() is called to setup some basic properties for the
1876 * upcoming transfer.
1877 */
1878void
1879Curl_setup_transfer(
1880  struct connectdata *conn, /* connection data */
1881  int sockindex,            /* socket index to read from or -1 */
1882  curl_off_t size,          /* -1 if unknown at this point */
1883  bool getheader,           /* TRUE if header parsing is wanted */
1884  curl_off_t *bytecountp,   /* return number of bytes read or NULL */
1885  int writesockindex,       /* socket index to write to, it may very well be
1886                               the same we read from. -1 disables */
1887  curl_off_t *writecountp   /* return number of bytes written or NULL */
1888  )
1889{
1890  struct Curl_easy *data;
1891  struct SingleRequest *k;
1892
1893  DEBUGASSERT(conn != NULL);
1894
1895  data = conn->data;
1896  k = &data->req;
1897
1898  DEBUGASSERT((sockindex <= 1) && (sockindex >= -1));
1899
1900  /* now copy all input parameters */
1901  conn->sockfd = sockindex == -1 ?
1902      CURL_SOCKET_BAD : conn->sock[sockindex];
1903  conn->writesockfd = writesockindex == -1 ?
1904      CURL_SOCKET_BAD:conn->sock[writesockindex];
1905  k->getheader = getheader;
1906
1907  k->size = size;
1908  k->bytecountp = bytecountp;
1909  k->writebytecountp = writecountp;
1910
1911  /* The code sequence below is placed in this function just because all
1912     necessary input is not always known in do_complete() as this function may
1913     be called after that */
1914
1915  if(!k->getheader) {
1916    k->header = FALSE;
1917    if(size > 0)
1918      Curl_pgrsSetDownloadSize(data, size);
1919  }
1920  /* we want header and/or body, if neither then don't do this! */
1921  if(k->getheader || !data->set.opt_no_body) {
1922
1923    if(conn->sockfd != CURL_SOCKET_BAD)
1924      k->keepon |= KEEP_RECV;
1925
1926    if(conn->writesockfd != CURL_SOCKET_BAD) {
1927      struct HTTP *http = data->req.protop;
1928      /* HTTP 1.1 magic:
1929
1930         Even if we require a 100-return code before uploading data, we might
1931         need to write data before that since the REQUEST may not have been
1932         finished sent off just yet.
1933
1934         Thus, we must check if the request has been sent before we set the
1935         state info where we wait for the 100-return code
1936      */
1937      if((data->state.expect100header) &&
1938         (conn->handler->protocol&PROTO_FAMILY_HTTP) &&
1939         (http->sending == HTTPSEND_BODY)) {
1940        /* wait with write until we either got 100-continue or a timeout */
1941        k->exp100 = EXP100_AWAITING_CONTINUE;
1942        k->start100 = Curl_tvnow();
1943
1944        /* Set a timeout for the multi interface. Add the inaccuracy margin so
1945           that we don't fire slightly too early and get denied to run. */
1946        Curl_expire(data, data->set.expect_100_timeout);
1947      }
1948      else {
1949        if(data->state.expect100header)
1950          /* when we've sent off the rest of the headers, we must await a
1951             100-continue but first finish sending the request */
1952          k->exp100 = EXP100_SENDING_REQUEST;
1953
1954        /* enable the write bit when we're not waiting for continue */
1955        k->keepon |= KEEP_SEND;
1956      }
1957    } /* if(conn->writesockfd != CURL_SOCKET_BAD) */
1958  } /* if(k->getheader || !data->set.opt_no_body) */
1959
1960}
1961