xref: /third_party/curl/lib/rtsp.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25#include "curl_setup.h"
26
27#if !defined(CURL_DISABLE_RTSP) && !defined(USE_HYPER)
28
29#include "urldata.h"
30#include <curl/curl.h>
31#include "transfer.h"
32#include "sendf.h"
33#include "multiif.h"
34#include "http.h"
35#include "url.h"
36#include "progress.h"
37#include "rtsp.h"
38#include "strcase.h"
39#include "select.h"
40#include "connect.h"
41#include "cfilters.h"
42#include "strdup.h"
43/* The last 3 #include files should be in this order */
44#include "curl_printf.h"
45#include "curl_memory.h"
46#include "memdebug.h"
47
48#define RTP_PKT_LENGTH(p) ((((unsigned int)((unsigned char)((p)[2]))) << 8) | \
49                            ((unsigned int)((unsigned char)((p)[3]))))
50
51/* protocol-specific functions set up to be called by the main engine */
52static CURLcode rtsp_do(struct Curl_easy *data, bool *done);
53static CURLcode rtsp_done(struct Curl_easy *data, CURLcode, bool premature);
54static CURLcode rtsp_connect(struct Curl_easy *data, bool *done);
55static CURLcode rtsp_disconnect(struct Curl_easy *data,
56                                struct connectdata *conn, bool dead);
57static int rtsp_getsock_do(struct Curl_easy *data,
58                           struct connectdata *conn, curl_socket_t *socks);
59
60/*
61 * Parse and write out an RTSP response.
62 * @param data     the transfer
63 * @param conn     the connection
64 * @param buf      data read from connection
65 * @param blen     amount of data in buf
66 * @param is_eos   TRUE iff this is the last write
67 * @param readmore out, TRUE iff complete buf was consumed and more data
68 *                 is needed
69 */
70static CURLcode rtsp_rtp_write_resp(struct Curl_easy *data,
71                                    const char *buf,
72                                    size_t blen,
73                                    bool is_eos,
74                                    bool *done);
75
76static CURLcode rtsp_setup_connection(struct Curl_easy *data,
77                                      struct connectdata *conn);
78static unsigned int rtsp_conncheck(struct Curl_easy *data,
79                                   struct connectdata *check,
80                                   unsigned int checks_to_perform);
81
82/* this returns the socket to wait for in the DO and DOING state for the multi
83   interface and then we're always _sending_ a request and thus we wait for
84   the single socket to become writable only */
85static int rtsp_getsock_do(struct Curl_easy *data, struct connectdata *conn,
86                           curl_socket_t *socks)
87{
88  /* write mode */
89  (void)data;
90  socks[0] = conn->sock[FIRSTSOCKET];
91  return GETSOCK_WRITESOCK(0);
92}
93
94static
95CURLcode rtp_client_write(struct Curl_easy *data, const char *ptr, size_t len);
96static
97CURLcode rtsp_parse_transport(struct Curl_easy *data, char *transport);
98
99
100/*
101 * RTSP handler interface.
102 */
103const struct Curl_handler Curl_handler_rtsp = {
104  "RTSP",                               /* scheme */
105  rtsp_setup_connection,                /* setup_connection */
106  rtsp_do,                              /* do_it */
107  rtsp_done,                            /* done */
108  ZERO_NULL,                            /* do_more */
109  rtsp_connect,                         /* connect_it */
110  ZERO_NULL,                            /* connecting */
111  ZERO_NULL,                            /* doing */
112  ZERO_NULL,                            /* proto_getsock */
113  rtsp_getsock_do,                      /* doing_getsock */
114  ZERO_NULL,                            /* domore_getsock */
115  ZERO_NULL,                            /* perform_getsock */
116  rtsp_disconnect,                      /* disconnect */
117  rtsp_rtp_write_resp,                  /* write_resp */
118  rtsp_conncheck,                       /* connection_check */
119  ZERO_NULL,                            /* attach connection */
120  PORT_RTSP,                            /* defport */
121  CURLPROTO_RTSP,                       /* protocol */
122  CURLPROTO_RTSP,                       /* family */
123  PROTOPT_NONE                          /* flags */
124};
125
126#define MAX_RTP_BUFFERSIZE 1000000 /* arbitrary */
127
128static CURLcode rtsp_setup_connection(struct Curl_easy *data,
129                                      struct connectdata *conn)
130{
131  struct RTSP *rtsp;
132  (void)conn;
133
134  data->req.p.rtsp = rtsp = calloc(1, sizeof(struct RTSP));
135  if(!rtsp)
136    return CURLE_OUT_OF_MEMORY;
137
138  Curl_dyn_init(&conn->proto.rtspc.buf, MAX_RTP_BUFFERSIZE);
139  return CURLE_OK;
140}
141
142
143/*
144 * Function to check on various aspects of a connection.
145 */
146static unsigned int rtsp_conncheck(struct Curl_easy *data,
147                                   struct connectdata *conn,
148                                   unsigned int checks_to_perform)
149{
150  unsigned int ret_val = CONNRESULT_NONE;
151  (void)data;
152
153  if(checks_to_perform & CONNCHECK_ISDEAD) {
154    bool input_pending;
155    if(!Curl_conn_is_alive(data, conn, &input_pending))
156      ret_val |= CONNRESULT_DEAD;
157  }
158
159  return ret_val;
160}
161
162
163static CURLcode rtsp_connect(struct Curl_easy *data, bool *done)
164{
165  CURLcode httpStatus;
166
167  httpStatus = Curl_http_connect(data, done);
168
169  /* Initialize the CSeq if not already done */
170  if(data->state.rtsp_next_client_CSeq == 0)
171    data->state.rtsp_next_client_CSeq = 1;
172  if(data->state.rtsp_next_server_CSeq == 0)
173    data->state.rtsp_next_server_CSeq = 1;
174
175  data->conn->proto.rtspc.rtp_channel = -1;
176
177  return httpStatus;
178}
179
180static CURLcode rtsp_disconnect(struct Curl_easy *data,
181                                struct connectdata *conn, bool dead)
182{
183  (void) dead;
184  (void) data;
185  Curl_dyn_free(&conn->proto.rtspc.buf);
186  return CURLE_OK;
187}
188
189
190static CURLcode rtsp_done(struct Curl_easy *data,
191                          CURLcode status, bool premature)
192{
193  struct RTSP *rtsp = data->req.p.rtsp;
194  CURLcode httpStatus;
195
196  /* Bypass HTTP empty-reply checks on receive */
197  if(data->set.rtspreq == RTSPREQ_RECEIVE)
198    premature = TRUE;
199
200  httpStatus = Curl_http_done(data, status, premature);
201
202  if(rtsp && !status && !httpStatus) {
203    /* Check the sequence numbers */
204    long CSeq_sent = rtsp->CSeq_sent;
205    long CSeq_recv = rtsp->CSeq_recv;
206    if((data->set.rtspreq != RTSPREQ_RECEIVE) && (CSeq_sent != CSeq_recv)) {
207      failf(data,
208            "The CSeq of this request %ld did not match the response %ld",
209            CSeq_sent, CSeq_recv);
210      return CURLE_RTSP_CSEQ_ERROR;
211    }
212    if(data->set.rtspreq == RTSPREQ_RECEIVE &&
213       (data->conn->proto.rtspc.rtp_channel == -1)) {
214      infof(data, "Got an RTP Receive with a CSeq of %ld", CSeq_recv);
215    }
216  }
217
218  return httpStatus;
219}
220
221static CURLcode rtsp_do(struct Curl_easy *data, bool *done)
222{
223  struct connectdata *conn = data->conn;
224  CURLcode result = CURLE_OK;
225  Curl_RtspReq rtspreq = data->set.rtspreq;
226  struct RTSP *rtsp = data->req.p.rtsp;
227  struct dynbuf req_buffer;
228  curl_off_t postsize = 0; /* for ANNOUNCE and SET_PARAMETER */
229  curl_off_t putsize = 0; /* for ANNOUNCE and SET_PARAMETER */
230
231  const char *p_request = NULL;
232  const char *p_session_id = NULL;
233  const char *p_accept = NULL;
234  const char *p_accept_encoding = NULL;
235  const char *p_range = NULL;
236  const char *p_referrer = NULL;
237  const char *p_stream_uri = NULL;
238  const char *p_transport = NULL;
239  const char *p_uagent = NULL;
240  const char *p_proxyuserpwd = NULL;
241  const char *p_userpwd = NULL;
242
243  *done = TRUE;
244
245  rtsp->CSeq_sent = data->state.rtsp_next_client_CSeq;
246  rtsp->CSeq_recv = 0;
247
248  /* Setup the first_* fields to allow auth details get sent
249     to this origin */
250
251  if(!data->state.first_host) {
252    data->state.first_host = strdup(conn->host.name);
253    if(!data->state.first_host)
254      return CURLE_OUT_OF_MEMORY;
255
256    data->state.first_remote_port = conn->remote_port;
257    data->state.first_remote_protocol = conn->handler->protocol;
258  }
259
260  /* Setup the 'p_request' pointer to the proper p_request string
261   * Since all RTSP requests are included here, there is no need to
262   * support custom requests like HTTP.
263   **/
264  data->req.no_body = TRUE; /* most requests don't contain a body */
265  switch(rtspreq) {
266  default:
267    failf(data, "Got invalid RTSP request");
268    return CURLE_BAD_FUNCTION_ARGUMENT;
269  case RTSPREQ_OPTIONS:
270    p_request = "OPTIONS";
271    break;
272  case RTSPREQ_DESCRIBE:
273    p_request = "DESCRIBE";
274    data->req.no_body = FALSE;
275    break;
276  case RTSPREQ_ANNOUNCE:
277    p_request = "ANNOUNCE";
278    break;
279  case RTSPREQ_SETUP:
280    p_request = "SETUP";
281    break;
282  case RTSPREQ_PLAY:
283    p_request = "PLAY";
284    break;
285  case RTSPREQ_PAUSE:
286    p_request = "PAUSE";
287    break;
288  case RTSPREQ_TEARDOWN:
289    p_request = "TEARDOWN";
290    break;
291  case RTSPREQ_GET_PARAMETER:
292    /* GET_PARAMETER's no_body status is determined later */
293    p_request = "GET_PARAMETER";
294    data->req.no_body = FALSE;
295    break;
296  case RTSPREQ_SET_PARAMETER:
297    p_request = "SET_PARAMETER";
298    break;
299  case RTSPREQ_RECORD:
300    p_request = "RECORD";
301    break;
302  case RTSPREQ_RECEIVE:
303    p_request = "";
304    /* Treat interleaved RTP as body */
305    data->req.no_body = FALSE;
306    break;
307  case RTSPREQ_LAST:
308    failf(data, "Got invalid RTSP request: RTSPREQ_LAST");
309    return CURLE_BAD_FUNCTION_ARGUMENT;
310  }
311
312  if(rtspreq == RTSPREQ_RECEIVE) {
313    Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE, -1);
314
315    return result;
316  }
317
318  p_session_id = data->set.str[STRING_RTSP_SESSION_ID];
319  if(!p_session_id &&
320     (rtspreq & ~(RTSPREQ_OPTIONS | RTSPREQ_DESCRIBE | RTSPREQ_SETUP))) {
321    failf(data, "Refusing to issue an RTSP request [%s] without a session ID.",
322          p_request);
323    return CURLE_BAD_FUNCTION_ARGUMENT;
324  }
325
326  /* Stream URI. Default to server '*' if not specified */
327  if(data->set.str[STRING_RTSP_STREAM_URI]) {
328    p_stream_uri = data->set.str[STRING_RTSP_STREAM_URI];
329  }
330  else {
331    p_stream_uri = "*";
332  }
333
334  /* Transport Header for SETUP requests */
335  p_transport = Curl_checkheaders(data, STRCONST("Transport"));
336  if(rtspreq == RTSPREQ_SETUP && !p_transport) {
337    /* New Transport: setting? */
338    if(data->set.str[STRING_RTSP_TRANSPORT]) {
339      Curl_safefree(data->state.aptr.rtsp_transport);
340
341      data->state.aptr.rtsp_transport =
342        aprintf("Transport: %s\r\n",
343                data->set.str[STRING_RTSP_TRANSPORT]);
344      if(!data->state.aptr.rtsp_transport)
345        return CURLE_OUT_OF_MEMORY;
346    }
347    else {
348      failf(data,
349            "Refusing to issue an RTSP SETUP without a Transport: header.");
350      return CURLE_BAD_FUNCTION_ARGUMENT;
351    }
352
353    p_transport = data->state.aptr.rtsp_transport;
354  }
355
356  /* Accept Headers for DESCRIBE requests */
357  if(rtspreq == RTSPREQ_DESCRIBE) {
358    /* Accept Header */
359    p_accept = Curl_checkheaders(data, STRCONST("Accept"))?
360      NULL:"Accept: application/sdp\r\n";
361
362    /* Accept-Encoding header */
363    if(!Curl_checkheaders(data, STRCONST("Accept-Encoding")) &&
364       data->set.str[STRING_ENCODING]) {
365      Curl_safefree(data->state.aptr.accept_encoding);
366      data->state.aptr.accept_encoding =
367        aprintf("Accept-Encoding: %s\r\n", data->set.str[STRING_ENCODING]);
368
369      if(!data->state.aptr.accept_encoding)
370        return CURLE_OUT_OF_MEMORY;
371
372      p_accept_encoding = data->state.aptr.accept_encoding;
373    }
374  }
375
376  /* The User-Agent string might have been allocated in url.c already, because
377     it might have been used in the proxy connect, but if we have got a header
378     with the user-agent string specified, we erase the previously made string
379     here. */
380  if(Curl_checkheaders(data, STRCONST("User-Agent")) &&
381     data->state.aptr.uagent) {
382    Curl_safefree(data->state.aptr.uagent);
383  }
384  else if(!Curl_checkheaders(data, STRCONST("User-Agent")) &&
385          data->set.str[STRING_USERAGENT]) {
386    p_uagent = data->state.aptr.uagent;
387  }
388
389  /* setup the authentication headers */
390  result = Curl_http_output_auth(data, conn, p_request, HTTPREQ_GET,
391                                 p_stream_uri, FALSE);
392  if(result)
393    return result;
394
395  p_proxyuserpwd = data->state.aptr.proxyuserpwd;
396  p_userpwd = data->state.aptr.userpwd;
397
398  /* Referrer */
399  Curl_safefree(data->state.aptr.ref);
400  if(data->state.referer && !Curl_checkheaders(data, STRCONST("Referer")))
401    data->state.aptr.ref = aprintf("Referer: %s\r\n", data->state.referer);
402
403  p_referrer = data->state.aptr.ref;
404
405  /*
406   * Range Header
407   * Only applies to PLAY, PAUSE, RECORD
408   *
409   * Go ahead and use the Range stuff supplied for HTTP
410   */
411  if(data->state.use_range &&
412     (rtspreq  & (RTSPREQ_PLAY | RTSPREQ_PAUSE | RTSPREQ_RECORD))) {
413
414    /* Check to see if there is a range set in the custom headers */
415    if(!Curl_checkheaders(data, STRCONST("Range")) && data->state.range) {
416      Curl_safefree(data->state.aptr.rangeline);
417      data->state.aptr.rangeline = aprintf("Range: %s\r\n", data->state.range);
418      p_range = data->state.aptr.rangeline;
419    }
420  }
421
422  /*
423   * Sanity check the custom headers
424   */
425  if(Curl_checkheaders(data, STRCONST("CSeq"))) {
426    failf(data, "CSeq cannot be set as a custom header.");
427    return CURLE_RTSP_CSEQ_ERROR;
428  }
429  if(Curl_checkheaders(data, STRCONST("Session"))) {
430    failf(data, "Session ID cannot be set as a custom header.");
431    return CURLE_BAD_FUNCTION_ARGUMENT;
432  }
433
434  /* Initialize a dynamic send buffer */
435  Curl_dyn_init(&req_buffer, DYN_RTSP_REQ_HEADER);
436
437  result =
438    Curl_dyn_addf(&req_buffer,
439                  "%s %s RTSP/1.0\r\n" /* Request Stream-URI RTSP/1.0 */
440                  "CSeq: %ld\r\n", /* CSeq */
441                  p_request, p_stream_uri, rtsp->CSeq_sent);
442  if(result)
443    return result;
444
445  /*
446   * Rather than do a normal alloc line, keep the session_id unformatted
447   * to make comparison easier
448   */
449  if(p_session_id) {
450    result = Curl_dyn_addf(&req_buffer, "Session: %s\r\n", p_session_id);
451    if(result)
452      return result;
453  }
454
455  /*
456   * Shared HTTP-like options
457   */
458  result = Curl_dyn_addf(&req_buffer,
459                         "%s" /* transport */
460                         "%s" /* accept */
461                         "%s" /* accept-encoding */
462                         "%s" /* range */
463                         "%s" /* referrer */
464                         "%s" /* user-agent */
465                         "%s" /* proxyuserpwd */
466                         "%s" /* userpwd */
467                         ,
468                         p_transport ? p_transport : "",
469                         p_accept ? p_accept : "",
470                         p_accept_encoding ? p_accept_encoding : "",
471                         p_range ? p_range : "",
472                         p_referrer ? p_referrer : "",
473                         p_uagent ? p_uagent : "",
474                         p_proxyuserpwd ? p_proxyuserpwd : "",
475                         p_userpwd ? p_userpwd : "");
476
477  /*
478   * Free userpwd now --- cannot reuse this for Negotiate and possibly NTLM
479   * with basic and digest, it will be freed anyway by the next request
480   */
481  Curl_safefree(data->state.aptr.userpwd);
482
483  if(result)
484    return result;
485
486  if((rtspreq == RTSPREQ_SETUP) || (rtspreq == RTSPREQ_DESCRIBE)) {
487    result = Curl_add_timecondition(data, &req_buffer);
488    if(result)
489      return result;
490  }
491
492  result = Curl_add_custom_headers(data, FALSE, &req_buffer);
493  if(result)
494    return result;
495
496  if(rtspreq == RTSPREQ_ANNOUNCE ||
497     rtspreq == RTSPREQ_SET_PARAMETER ||
498     rtspreq == RTSPREQ_GET_PARAMETER) {
499
500    if(data->state.upload) {
501      putsize = data->state.infilesize;
502      data->state.httpreq = HTTPREQ_PUT;
503
504    }
505    else {
506      postsize = (data->state.infilesize != -1)?
507        data->state.infilesize:
508        (data->set.postfields? (curl_off_t)strlen(data->set.postfields):0);
509      data->state.httpreq = HTTPREQ_POST;
510    }
511
512    if(putsize > 0 || postsize > 0) {
513      /* As stated in the http comments, it is probably not wise to
514       * actually set a custom Content-Length in the headers */
515      if(!Curl_checkheaders(data, STRCONST("Content-Length"))) {
516        result =
517          Curl_dyn_addf(&req_buffer,
518                        "Content-Length: %" CURL_FORMAT_CURL_OFF_T"\r\n",
519                        (data->state.upload ? putsize : postsize));
520        if(result)
521          return result;
522      }
523
524      if(rtspreq == RTSPREQ_SET_PARAMETER ||
525         rtspreq == RTSPREQ_GET_PARAMETER) {
526        if(!Curl_checkheaders(data, STRCONST("Content-Type"))) {
527          result = Curl_dyn_addn(&req_buffer,
528                                 STRCONST("Content-Type: "
529                                          "text/parameters\r\n"));
530          if(result)
531            return result;
532        }
533      }
534
535      if(rtspreq == RTSPREQ_ANNOUNCE) {
536        if(!Curl_checkheaders(data, STRCONST("Content-Type"))) {
537          result = Curl_dyn_addn(&req_buffer,
538                                 STRCONST("Content-Type: "
539                                          "application/sdp\r\n"));
540          if(result)
541            return result;
542        }
543      }
544
545      data->state.expect100header = FALSE; /* RTSP posts are simple/small */
546    }
547    else if(rtspreq == RTSPREQ_GET_PARAMETER) {
548      /* Check for an empty GET_PARAMETER (heartbeat) request */
549      data->state.httpreq = HTTPREQ_HEAD;
550      data->req.no_body = TRUE;
551    }
552  }
553
554  /* RTSP never allows chunked transfer */
555  data->req.forbidchunk = TRUE;
556  /* Finish the request buffer */
557  result = Curl_dyn_addn(&req_buffer, STRCONST("\r\n"));
558  if(result)
559    return result;
560
561  if(postsize > 0) {
562    result = Curl_dyn_addn(&req_buffer, data->set.postfields,
563                           (size_t)postsize);
564    if(result)
565      return result;
566  }
567
568  /* issue the request */
569  result = Curl_buffer_send(&req_buffer, data, data->req.p.http,
570                            &data->info.request_size, 0, FIRSTSOCKET);
571  if(result) {
572    failf(data, "Failed sending RTSP request");
573    return result;
574  }
575
576  Curl_setup_transfer(data, FIRSTSOCKET, -1, TRUE, putsize?FIRSTSOCKET:-1);
577
578  /* Increment the CSeq on success */
579  data->state.rtsp_next_client_CSeq++;
580
581  if(data->req.writebytecount) {
582    /* if a request-body has been sent off, we make sure this progress is
583       noted properly */
584    Curl_pgrsSetUploadCounter(data, data->req.writebytecount);
585    if(Curl_pgrsUpdate(data))
586      result = CURLE_ABORTED_BY_CALLBACK;
587  }
588
589  return result;
590}
591
592/**
593 * write any BODY bytes missing to the client, ignore the rest.
594 */
595static CURLcode rtp_write_body_junk(struct Curl_easy *data,
596                                    const char *buf,
597                                    size_t blen)
598{
599  struct rtsp_conn *rtspc = &(data->conn->proto.rtspc);
600  curl_off_t body_remain;
601  bool in_body;
602
603  in_body = (data->req.headerline && !rtspc->in_header) &&
604            (data->req.size >= 0) &&
605            (data->req.bytecount < data->req.size);
606  body_remain = in_body? (data->req.size - data->req.bytecount) : 0;
607  DEBUGASSERT(body_remain >= 0);
608  if(body_remain) {
609    if((curl_off_t)blen > body_remain)
610      blen = (size_t)body_remain;
611    return Curl_client_write(data, CLIENTWRITE_BODY, (char *)buf, blen);
612  }
613  return CURLE_OK;
614}
615
616static CURLcode rtsp_filter_rtp(struct Curl_easy *data,
617                                     const char *buf,
618                                     size_t blen,
619                                     size_t *pconsumed)
620{
621  struct rtsp_conn *rtspc = &(data->conn->proto.rtspc);
622  CURLcode result = CURLE_OK;
623  size_t skip_len = 0;
624
625  *pconsumed = 0;
626  while(blen) {
627    bool in_body = (data->req.headerline && !rtspc->in_header) &&
628                   (data->req.size >= 0) &&
629                   (data->req.bytecount < data->req.size);
630    switch(rtspc->state) {
631
632    case RTP_PARSE_SKIP: {
633      DEBUGASSERT(Curl_dyn_len(&rtspc->buf) == 0);
634      while(blen && buf[0] != '$') {
635        if(!in_body && buf[0] == 'R' &&
636           data->set.rtspreq != RTSPREQ_RECEIVE) {
637          if(strncmp(buf, "RTSP/", (blen < 5) ? blen : 5) == 0) {
638            /* This could be the next response, no consume and return */
639            if(*pconsumed) {
640              DEBUGF(infof(data, "RTP rtsp_filter_rtp[SKIP] RTSP/ prefix, "
641                           "skipping %zd bytes of junk", *pconsumed));
642            }
643            rtspc->state = RTP_PARSE_SKIP;
644            rtspc->in_header = TRUE;
645            goto out;
646          }
647        }
648        /* junk/BODY, consume without buffering */
649        *pconsumed += 1;
650        ++buf;
651        --blen;
652        ++skip_len;
653      }
654      if(blen && buf[0] == '$') {
655        /* possible start of an RTP message, buffer */
656        if(skip_len) {
657          /* end of junk/BODY bytes, flush */
658          result = rtp_write_body_junk(data,
659                                       (char *)(buf - skip_len), skip_len);
660          skip_len = 0;
661          if(result)
662            goto out;
663        }
664        if(Curl_dyn_addn(&rtspc->buf, buf, 1)) {
665          result = CURLE_OUT_OF_MEMORY;
666          goto out;
667        }
668        *pconsumed += 1;
669        ++buf;
670        --blen;
671        rtspc->state = RTP_PARSE_CHANNEL;
672      }
673      break;
674    }
675
676    case RTP_PARSE_CHANNEL: {
677      int idx = ((unsigned char)buf[0]) / 8;
678      int off = ((unsigned char)buf[0]) % 8;
679      DEBUGASSERT(Curl_dyn_len(&rtspc->buf) == 1);
680      if(!(data->state.rtp_channel_mask[idx] & (1 << off))) {
681        /* invalid channel number, junk or BODY data */
682        rtspc->state = RTP_PARSE_SKIP;
683        DEBUGASSERT(skip_len == 0);
684        /* we do not consume this byte, it is BODY data */
685        DEBUGF(infof(data, "RTSP: invalid RTP channel %d, skipping", idx));
686        if(*pconsumed == 0) {
687          /* We did not consume the initial '$' in our buffer, but had
688           * it from an earlier call. We cannot un-consume it and have
689           * to write it directly as BODY data */
690          result = rtp_write_body_junk(data, Curl_dyn_ptr(&rtspc->buf), 1);
691          if(result)
692            goto out;
693        }
694        else {
695          /* count the '$' as skip and continue */
696          skip_len = 1;
697        }
698        Curl_dyn_free(&rtspc->buf);
699        break;
700      }
701      /* a valid channel, so we expect this to be a real RTP message */
702      rtspc->rtp_channel = (unsigned char)buf[0];
703      if(Curl_dyn_addn(&rtspc->buf, buf, 1)) {
704        result = CURLE_OUT_OF_MEMORY;
705        goto out;
706      }
707      *pconsumed += 1;
708      ++buf;
709      --blen;
710      rtspc->state = RTP_PARSE_LEN;
711      break;
712    }
713
714    case RTP_PARSE_LEN: {
715      size_t rtp_len = Curl_dyn_len(&rtspc->buf);
716      const char *rtp_buf;
717      DEBUGASSERT(rtp_len >= 2 && rtp_len < 4);
718      if(Curl_dyn_addn(&rtspc->buf, buf, 1)) {
719        result = CURLE_OUT_OF_MEMORY;
720        goto out;
721      }
722      *pconsumed += 1;
723      ++buf;
724      --blen;
725      if(rtp_len == 2)
726        break;
727      rtp_buf = Curl_dyn_ptr(&rtspc->buf);
728      rtspc->rtp_len = RTP_PKT_LENGTH(rtp_buf) + 4;
729      rtspc->state = RTP_PARSE_DATA;
730      break;
731    }
732
733    case RTP_PARSE_DATA: {
734      size_t rtp_len = Curl_dyn_len(&rtspc->buf);
735      size_t needed;
736      DEBUGASSERT(rtp_len < rtspc->rtp_len);
737      needed = rtspc->rtp_len - rtp_len;
738      if(needed <= blen) {
739        if(Curl_dyn_addn(&rtspc->buf, buf, needed)) {
740          result = CURLE_OUT_OF_MEMORY;
741          goto out;
742        }
743        *pconsumed += needed;
744        buf += needed;
745        blen -= needed;
746        /* complete RTP message in buffer */
747        DEBUGF(infof(data, "RTP write channel %d rtp_len %zu",
748                     rtspc->rtp_channel, rtspc->rtp_len));
749        result = rtp_client_write(data, Curl_dyn_ptr(&rtspc->buf),
750                                  rtspc->rtp_len);
751        Curl_dyn_free(&rtspc->buf);
752        rtspc->state = RTP_PARSE_SKIP;
753        if(result)
754          goto out;
755      }
756      else {
757        if(Curl_dyn_addn(&rtspc->buf, buf, blen)) {
758          result = CURLE_OUT_OF_MEMORY;
759          goto out;
760        }
761        *pconsumed += blen;
762        buf += blen;
763        blen = 0;
764      }
765      break;
766    }
767
768    default:
769      DEBUGASSERT(0);
770      return CURLE_RECV_ERROR;
771    }
772  }
773out:
774  if(!result && skip_len)
775    result = rtp_write_body_junk(data, (char *)(buf - skip_len), skip_len);
776  return result;
777}
778
779static CURLcode rtsp_rtp_write_resp(struct Curl_easy *data,
780                                    const char *buf,
781                                    size_t blen,
782                                    bool is_eos,
783                                    bool *done)
784{
785  struct rtsp_conn *rtspc = &(data->conn->proto.rtspc);
786  CURLcode result = CURLE_OK;
787  size_t consumed = 0;
788
789  if(!data->req.header)
790    rtspc->in_header = FALSE;
791  *done = FALSE;
792  if(!blen) {
793    goto out;
794  }
795
796  DEBUGF(infof(data, "rtsp_rtp_write_resp(len=%zu, in_header=%d, eos=%d)",
797               blen, rtspc->in_header, is_eos));
798
799  /* If header parsing is not onging, extract RTP messages */
800  if(!rtspc->in_header) {
801    result = rtsp_filter_rtp(data, buf, blen, &consumed);
802    if(result)
803      goto out;
804    buf += consumed;
805    blen -= consumed;
806    /* either we consumed all or are at the start of header parsing */
807    if(blen && !data->req.header)
808      DEBUGF(infof(data, "RTSP: %zu bytes, possibly excess in response body",
809                   blen));
810  }
811
812  /* we want to parse headers, do so */
813  if(data->req.header && blen) {
814    rtspc->in_header = TRUE;
815    result = Curl_http_write_resp_hds(data, buf, blen, &consumed, done);
816    if(result)
817      goto out;
818
819    buf += consumed;
820    blen -= consumed;
821
822    if(!data->req.header)
823      rtspc->in_header = FALSE;
824
825    if(!rtspc->in_header) {
826      /* If header parsing is done, extract interleaved RTP messages */
827      if(data->req.size <= -1) {
828        /* Respect section 4.4 of rfc2326: If the Content-Length header is
829           absent, a length 0 must be assumed. */
830        data->req.size = 0;
831        data->req.download_done = TRUE;
832      }
833      result = rtsp_filter_rtp(data, buf, blen, &consumed);
834      if(result)
835        goto out;
836      blen -= consumed;
837    }
838  }
839
840  if(rtspc->state != RTP_PARSE_SKIP)
841    *done = FALSE;
842  /* we SHOULD have consumed all bytes, unless the response is borked.
843   * In which case we write out the left over bytes, letting the client
844   * writer deal with it (it will report EXCESS and fail the transfer). */
845  DEBUGF(infof(data, "rtsp_rtp_write_resp(len=%zu, in_header=%d, done=%d "
846               " rtspc->state=%d, req.size=%" CURL_FORMAT_CURL_OFF_T ")",
847               blen, rtspc->in_header, *done, rtspc->state, data->req.size));
848  if(!result && (is_eos || blen)) {
849    result = Curl_client_write(data, CLIENTWRITE_BODY|
850                               (is_eos? CLIENTWRITE_EOS:0),
851                               (char *)buf, blen);
852  }
853
854out:
855  if((data->set.rtspreq == RTSPREQ_RECEIVE) &&
856     (rtspc->state == RTP_PARSE_SKIP)) {
857    /* In special mode RECEIVE, we just process one chunk of network
858     * data, so we stop the transfer here, if we have no incomplete
859     * RTP message pending. */
860    data->req.download_done = TRUE;
861  }
862  return result;
863}
864
865static
866CURLcode rtp_client_write(struct Curl_easy *data, const char *ptr, size_t len)
867{
868  size_t wrote;
869  curl_write_callback writeit;
870  void *user_ptr;
871
872  if(len == 0) {
873    failf(data, "Cannot write a 0 size RTP packet.");
874    return CURLE_WRITE_ERROR;
875  }
876
877  /* If the user has configured CURLOPT_INTERLEAVEFUNCTION then use that
878     function and any configured CURLOPT_INTERLEAVEDATA to write out the RTP
879     data. Otherwise, use the CURLOPT_WRITEFUNCTION with the CURLOPT_WRITEDATA
880     pointer to write out the RTP data. */
881  if(data->set.fwrite_rtp) {
882    writeit = data->set.fwrite_rtp;
883    user_ptr = data->set.rtp_out;
884  }
885  else {
886    writeit = data->set.fwrite_func;
887    user_ptr = data->set.out;
888  }
889
890  Curl_set_in_callback(data, true);
891  wrote = writeit((char *)ptr, 1, len, user_ptr);
892  Curl_set_in_callback(data, false);
893
894  if(CURL_WRITEFUNC_PAUSE == wrote) {
895    failf(data, "Cannot pause RTP");
896    return CURLE_WRITE_ERROR;
897  }
898
899  if(wrote != len) {
900    failf(data, "Failed writing RTP data");
901    return CURLE_WRITE_ERROR;
902  }
903
904  return CURLE_OK;
905}
906
907CURLcode Curl_rtsp_parseheader(struct Curl_easy *data, char *header)
908{
909  if(checkprefix("CSeq:", header)) {
910    long CSeq = 0;
911    char *endp;
912    char *p = &header[5];
913    while(ISBLANK(*p))
914      p++;
915    CSeq = strtol(p, &endp, 10);
916    if(p != endp) {
917      struct RTSP *rtsp = data->req.p.rtsp;
918      rtsp->CSeq_recv = CSeq; /* mark the request */
919      data->state.rtsp_CSeq_recv = CSeq; /* update the handle */
920    }
921    else {
922      failf(data, "Unable to read the CSeq header: [%s]", header);
923      return CURLE_RTSP_CSEQ_ERROR;
924    }
925  }
926  else if(checkprefix("Session:", header)) {
927    char *start;
928    char *end;
929    size_t idlen;
930
931    /* Find the first non-space letter */
932    start = header + 8;
933    while(*start && ISBLANK(*start))
934      start++;
935
936    if(!*start) {
937      failf(data, "Got a blank Session ID");
938      return CURLE_RTSP_SESSION_ERROR;
939    }
940
941    /* Find the end of Session ID
942     *
943     * Allow any non whitespace content, up to the field separator or end of
944     * line. RFC 2326 isn't 100% clear on the session ID and for example
945     * gstreamer does url-encoded session ID's not covered by the standard.
946     */
947    end = start;
948    while(*end && *end != ';' && !ISSPACE(*end))
949      end++;
950    idlen = end - start;
951
952    if(data->set.str[STRING_RTSP_SESSION_ID]) {
953
954      /* If the Session ID is set, then compare */
955      if(strlen(data->set.str[STRING_RTSP_SESSION_ID]) != idlen ||
956         strncmp(start, data->set.str[STRING_RTSP_SESSION_ID], idlen)) {
957        failf(data, "Got RTSP Session ID Line [%s], but wanted ID [%s]",
958              start, data->set.str[STRING_RTSP_SESSION_ID]);
959        return CURLE_RTSP_SESSION_ERROR;
960      }
961    }
962    else {
963      /* If the Session ID is not set, and we find it in a response, then set
964       * it.
965       */
966
967      /* Copy the id substring into a new buffer */
968      data->set.str[STRING_RTSP_SESSION_ID] = Curl_memdup0(start, idlen);
969      if(!data->set.str[STRING_RTSP_SESSION_ID])
970        return CURLE_OUT_OF_MEMORY;
971    }
972  }
973  else if(checkprefix("Transport:", header)) {
974    CURLcode result;
975    result = rtsp_parse_transport(data, header + 10);
976    if(result)
977      return result;
978  }
979  return CURLE_OK;
980}
981
982static
983CURLcode rtsp_parse_transport(struct Curl_easy *data, char *transport)
984{
985  /* If we receive multiple Transport response-headers, the linterleaved
986     channels of each response header is recorded and used together for
987     subsequent data validity checks.*/
988  /* e.g.: ' RTP/AVP/TCP;unicast;interleaved=5-6' */
989  char *start;
990  char *end;
991  start = transport;
992  while(start && *start) {
993    while(*start && ISBLANK(*start) )
994      start++;
995    end = strchr(start, ';');
996    if(checkprefix("interleaved=", start)) {
997      long chan1, chan2, chan;
998      char *endp;
999      char *p = start + 12;
1000      chan1 = strtol(p, &endp, 10);
1001      if(p != endp && chan1 >= 0 && chan1 <= 255) {
1002        unsigned char *rtp_channel_mask = data->state.rtp_channel_mask;
1003        chan2 = chan1;
1004        if(*endp == '-') {
1005          p = endp + 1;
1006          chan2 = strtol(p, &endp, 10);
1007          if(p == endp || chan2 < 0 || chan2 > 255) {
1008            infof(data, "Unable to read the interleaved parameter from "
1009                  "Transport header: [%s]", transport);
1010            chan2 = chan1;
1011          }
1012        }
1013        for(chan = chan1; chan <= chan2; chan++) {
1014          long idx = chan / 8;
1015          long off = chan % 8;
1016          rtp_channel_mask[idx] |= (unsigned char)(1 << off);
1017        }
1018      }
1019      else {
1020        infof(data, "Unable to read the interleaved parameter from "
1021              "Transport header: [%s]", transport);
1022      }
1023      break;
1024    }
1025    /* skip to next parameter */
1026    start = (!end) ? end : (end + 1);
1027  }
1028  return CURLE_OK;
1029}
1030
1031
1032#endif /* CURL_DISABLE_RTSP or using Hyper */
1033