rtsp.c

vlc源码

/*****************************************************************************
 * rtsp.c: minimalistic implementation of rtsp protocol.
 *         Not RFC 2326 compilant yet and only handle REAL RTSP.
 *****************************************************************************
 * Copyright (C) 2002-2004 the xine project
 * Copyright (C) 2005 VideoLAN
 * $Id$
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Adapted from xine which itself adapted it from joschkas real tools.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <vlc_common.h>

#include "rtsp.h"

#define BUF_SIZE 4096
#define HEADER_SIZE 1024
#define MAX_FIELDS 256

struct rtsp_s {

  int           s;

  char         *host;
  int           port;
  char         *path;
  char         *mrl;
  char         *user_agent;

  char         *server;
  unsigned int  server_state;
  uint32_t      server_caps;

  unsigned int  cseq;
  char         *session;

  char        *answers[MAX_FIELDS];   /* data of last message */
  char        *scheduled[MAX_FIELDS]; /* will be sent with next message */
};

/*
 * constants
 */

const char rtsp_protocol_version[]="RTSP/1.0";

/* server states */
#define RTSP_CONNECTED 1
#define RTSP_INIT      2
#define RTSP_READY     4
#define RTSP_PLAYING   8
#define RTSP_RECORDING 16

/* server capabilities */
#define RTSP_OPTIONS       0x001
#define RTSP_DESCRIBE      0x002
#define RTSP_ANNOUNCE      0x004
#define RTSP_SETUP         0x008
#define RTSP_GET_PARAMETER 0x010
#define RTSP_SET_PARAMETER 0x020
#define RTSP_TEARDOWN      0x040
#define RTSP_PLAY          0x080
#define RTSP_RECORD        0x100

/*
 * rtsp_get gets a line from stream
 * and returns a null terminated string (must be freed).
 */
 
static char *rtsp_get( rtsp_client_t *rtsp )
{
  char *psz_buffer = malloc( BUF_SIZE );
  char *psz_string = NULL;

  if( rtsp->pf_read_line( rtsp->p_userdata, (uint8_t*)psz_buffer, (unsigned int)BUF_SIZE ) >= 0 )
  {
    //printf( "<< '%s'\n", psz_buffer );
      psz_string = strdup( psz_buffer );
  }

  free( psz_buffer );
  return psz_string;
}


/*
 * rtsp_put puts a line on stream
 */

static int rtsp_put( rtsp_client_t *rtsp, const char *psz_string )
{
    unsigned int i_buffer = strlen( psz_string );
    char *psz_buffer = malloc( i_buffer + 3 );
    int i_ret;

    strcpy( psz_buffer, psz_string );
    psz_buffer[i_buffer] = '\r'; psz_buffer[i_buffer+1] = '\n';
    psz_buffer[i_buffer+2] = 0;

    i_ret = rtsp->pf_write( rtsp->p_userdata, (uint8_t*)psz_buffer, i_buffer + 2 );

    free( psz_buffer );
    return i_ret;
}

/*
 * extract server status code
 */

static int rtsp_get_status_code( rtsp_client_t *rtsp, const char *psz_string )
{
    char psz_buffer[4];
    int i_code = 0;

    if( !strncmp( psz_string, "RTSP/1.0", sizeof("RTSP/1.0") - 1 ) )
    {
        memcpy( psz_buffer, psz_string + sizeof("RTSP/1.0"), 3 );
        psz_buffer[3] = 0;
        i_code = atoi( psz_buffer );
    }
    else if( !strncmp( psz_string, "SET_PARAMETER", 8 ) )
    {
        return RTSP_STATUS_SET_PARAMETER;
    }

    if( i_code != 200 )
    {
        //fprintf( stderr, "librtsp: server responds: '%s'\n", psz_string );
    }

    return i_code;
}

/*
 * send a request
 */

static int rtsp_send_request( rtsp_client_t *rtsp, const char *psz_type,
                              const char *psz_what )
{
    char **ppsz_payload = rtsp->p_private->scheduled;
    char *psz_buffer;
    int i_ret;

    psz_buffer = malloc( strlen(psz_type) + strlen(psz_what) +
                         sizeof("RTSP/1.0") + 2 );

    sprintf( psz_buffer, "%s %s %s", psz_type, psz_what, "RTSP/1.0" );
    i_ret = rtsp_put( rtsp, psz_buffer );
    free( psz_buffer );

    if( ppsz_payload )
        while( *ppsz_payload )
        {
            rtsp_put( rtsp, *ppsz_payload );
            ppsz_payload++;
        }
    rtsp_put( rtsp, "" );
    rtsp_unschedule_all( rtsp );

    return i_ret;
}

/*
 * schedule standard fields
 */

static void rtsp_schedule_standard( rtsp_client_t *rtsp )
{
    char tmp[17];

    sprintf( tmp, "Cseq: %u", rtsp->p_private->cseq);
    rtsp_schedule_field( rtsp, tmp );

    if( rtsp->p_private->session )
    {
        char *buf;
        buf = malloc( strlen(rtsp->p_private->session) + 15 );
        sprintf( buf, "Session: %s", rtsp->p_private->session );
        rtsp_schedule_field( rtsp, buf );
        free( buf );
    }
}

/*
 * get the answers, if server responses with something != 200, return NULL
 */

static int rtsp_get_answers( rtsp_client_t *rtsp )
{
    char *answer = NULL;
    unsigned int answer_seq;
    char **answer_ptr = rtsp->p_private->answers;
    int code;
    int ans_count = 0;

    answer = rtsp_get( rtsp );
    if( !answer ) return 0;
    code = rtsp_get_status_code( rtsp, answer );
    free( answer );

    rtsp_free_answers( rtsp );

    do { /* while we get answer lines */

      answer = rtsp_get( rtsp );
      if( !answer ) return 0;

      if( !strncasecmp( answer, "Cseq:", 5 ) )
      {
          sscanf( answer, "%*s %u", &answer_seq );
          if( rtsp->p_private->cseq != answer_seq )
          {
            //fprintf( stderr, "warning: Cseq mismatch. got %u, assumed %u",
            //       answer_seq, rtsp->p_private->cseq );

              rtsp->p_private->cseq = answer_seq;
          }
      }
      if( !strncasecmp( answer, "Server:", 7 ) )
      {
          char *buf = malloc( strlen(answer) );
          sscanf( answer, "%*s %s", buf );
          free( rtsp->p_private->server );
          rtsp->p_private->server = buf;
      }
      if( !strncasecmp( answer, "Session:", 8 ) )
      {
          char *buf = malloc( strlen(answer) );
          sscanf( answer, "%*s %s", buf );
          if( rtsp->p_private->session )
          {
              if( strcmp( buf, rtsp->p_private->session ) )
              {
                  //fprintf( stderr,
                  //         "rtsp: warning: setting NEW session: %s\n", buf );
                  free( rtsp->p_private->session );
                  rtsp->p_private->session = strdup( buf );
              }
          }
          else
          {
              //fprintf( stderr, "setting session id to: %s\n", buf );
              rtsp->p_private->session = strdup( buf );
          }
          free( buf );
      }

      *answer_ptr = answer;
      answer_ptr++;
    } while( (strlen(answer) != 0) && (++ans_count < MAX_FIELDS) );

    rtsp->p_private->cseq++;

    *answer_ptr = NULL;
    rtsp_schedule_standard( rtsp );

    return code;
}

/*
 * send an ok message
 */

int rtsp_send_ok( rtsp_client_t *rtsp )
{
    char cseq[16];

    rtsp_put( rtsp, "RTSP/1.0 200 OK" );
    sprintf( cseq, "CSeq: %u", rtsp->p_private->cseq );
    rtsp_put( rtsp, cseq );
    rtsp_put( rtsp, "" );
    return 0;
}

/*
 * implementation of must-have rtsp requests; functions return
 * server status code.
 */

int rtsp_request_options( rtsp_client_t *rtsp, const char *what )
{
    char *buf;

    if( what ) buf = strdup(what);
    else
    {
        buf = malloc( strlen(rtsp->p_private->host) + 16 );
        sprintf( buf, "rtsp://%s:%i", rtsp->p_private->host,
                 rtsp->p_private->port );
    }
    rtsp_send_request( rtsp, "OPTIONS", buf );
    free( buf );

    return rtsp_get_answers( rtsp );
}

int rtsp_request_describe( rtsp_client_t *rtsp, const char *what )
{
    char *buf;

    if( what )
    {
        buf = strdup(what);
    }
    else
    {
        buf = malloc( strlen(rtsp->p_private->host) +
                      strlen(rtsp->p_private->path) + 16 );
        sprintf( buf, "rtsp://%s:%i/%s", rtsp->p_private->host,
                 rtsp->p_private->port, rtsp->p_private->path );
    }
    rtsp_send_request( rtsp, "DESCRIBE", buf );
    free( buf );

    return rtsp_get_answers( rtsp );
}

int rtsp_request_setup( rtsp_client_t *rtsp, const char *what )
{
    rtsp_send_request( rtsp, "SETUP", what );
    return rtsp_get_answers( rtsp );
}

int rtsp_request_setparameter( rtsp_client_t *rtsp, const char *what )
{
    char *buf;