rtspserver.cpp.save

流媒体传输协议的实现代码,非常有用.可以支持rtsp mms等流媒体传输协议

	   cseq, dateHeader(), allowedCommandNames);
}

void RTSPServer::RTSPClientSession
::handleCmd_DESCRIBE(char const* cseq, char const* urlSuffix,
		     char const* fullRequestStr) {
  char* sdpDescription = NULL;
  char* rtspURL = NULL;
  do {
    if (!authenticationOK("DESCRIBE", cseq, fullRequestStr)) break;

    // We should really check that the request contains an "Accept:" #####
    // for "application/sdp", because that's what we're sending back #####

    // Begin by looking up the "ServerMediaSession" object for the
    // specified "urlSuffix":
    ServerMediaSession* session = fOurServer.lookupServerMediaSession(urlSuffix);
    if (session == NULL) {
      handleCmd_notFound(cseq);
      break;
    }

    // Then, assemble a SDP description for this session:
    sdpDescription = session->generateSDPDescription();
    if (sdpDescription == NULL) {
      // This usually means that a file name that was specified for a
      // "ServerMediaSubsession" does not exist.
      snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	       "RTSP/1.0 404 File Not Found, Or In Incorrect Format\r\n"
	       "CSeq: %s\r\n"
	       "%s\r\n",
	       cseq,
	       dateHeader());
     break;
    }
    unsigned sdpDescriptionSize = strlen(sdpDescription);

    // Also, generate our RTSP URL, for the "Content-Base:" header
    // (which is necessary to ensure that the correct URL gets used in
    // subsequent "SETUP" requests).
    rtspURL = fOurServer.rtspURL(session);

    snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	     "RTSP/1.0 200 OK\r\nCSeq: %s\r\n"
	     "%s"
	     "Content-Base: %s/\r\n"
	     "Content-Type: application/sdp\r\n"
	     "Content-Length: %d\r\n\r\n"
	     "%s",
	     cseq,
	     dateHeader(),
	     rtspURL,
	     sdpDescriptionSize,
	     sdpDescription);
  } while (0);

  delete[] sdpDescription;
  delete[] rtspURL;
}

typedef enum StreamingMode {
  RTP_UDP,
  RTP_TCP,
  RAW_UDP
};

static void parseTransportHeader(char const* buf,
				 StreamingMode& streamingMode,
				 char*& streamingModeString,
				 char*& destinationAddressStr,
				 u_int8_t& destinationTTL,
				 portNumBits& clientRTPPortNum, // if UDP
				 portNumBits& clientRTCPPortNum, // if UDP
				 unsigned char& rtpChannelId, // if TCP
				 unsigned char& rtcpChannelId // if TCP
				 ) {
  // Initialize the result parameters to default values:
  streamingMode = RTP_UDP;
  streamingModeString = NULL;
  destinationAddressStr = NULL;
  destinationTTL = 255;
  clientRTPPortNum = 0;
  clientRTCPPortNum = 1; 
  rtpChannelId = rtcpChannelId = 0xFF;

  portNumBits p1, p2;
  unsigned ttl, rtpCid, rtcpCid;

  // First, find "Transport:"
  while (1) {
    if (*buf == '\0') return; // not found
    if (_strncasecmp(buf, "Transport: ", 11) == 0) break;
    ++buf;
  }

  // Then, run through each of the fields, looking for ones we handle:
  char const* fields = buf + 11;
  char* field = strDupSize(fields);
  while (sscanf(fields, "%[^;]", field) == 1) {
    if (strcmp(field, "RTP/AVP/TCP") == 0) {
      streamingMode = RTP_TCP;
    } else if (strcmp(field, "RAW/RAW/UDP") == 0 ||
	       strcmp(field, "MP2T/H2221/UDP") == 0) {
      streamingMode = RAW_UDP;
      streamingModeString = strDup(field);
    } else if (_strncasecmp(field, "destination=", 12) == 0) {
      delete[] destinationAddressStr;
      destinationAddressStr = strDup(field+12);
    } else if (sscanf(field, "ttl%u", &ttl) == 1) {
      destinationTTL = (u_int8_t)ttl;
    } else if (sscanf(field, "client_port=%hu-%hu", &p1, &p2) == 2) {
	clientRTPPortNum = p1;
	clientRTCPPortNum = p2;
    } else if (sscanf(field, "client_port=%hu", &p1) == 1) {
	clientRTPPortNum = p1;
	clientRTCPPortNum = streamingMode == RAW_UDP ? 0 : p1 + 1;
    } else if (sscanf(field, "interleaved=%u-%u", &rtpCid, &rtcpCid) == 2) {
      rtpChannelId = (unsigned char)rtpCid;
      rtcpChannelId = (unsigned char)rtcpCid;
    }

    fields += strlen(field);
    while (*fields == ';') ++fields; // skip over separating ';' chars
    if (*fields == '\0' || *fields == '\r' || *fields == '\n') break;
  }
  delete[] field;
}

static Boolean parseRangeHeader(char const* buf, float& rangeStart, float& rangeEnd) {
  // Initialize the result parameters to default values:
  rangeStart = rangeEnd = 0.0;

  // First, find "Range:"
  while (1) {
    if (*buf == '\0') return False; // not found
    if (_strncasecmp(buf, "Range: ", 7) == 0) break;
    ++buf;
  }

  // Then, run through each of the fields, looking for ones we handle:
  char const* fields = buf + 7;
  while (*fields == ' ') ++fields;
  float start, end;
  if (sscanf(fields, "npt = %f - %f", &start, &end) == 2) {
    rangeStart = start;
    rangeEnd = end;
  } else if (sscanf(fields, "npt = %f -", &start) == 1) {
    rangeStart = start;
  } else {
    return False; // The header is malformed
  }

  return True;
}

void RTSPServer::RTSPClientSession
::handleCmd_SETUP(char const* cseq,
		  char const* urlPreSuffix, char const* urlSuffix,
		  char const* fullRequestStr) {
  // "urlPreSuffix" should be the session (stream) name, and
  // "urlSuffix" should be the subsession (track) name.
  char const* streamName = urlPreSuffix;
  char const* trackId = urlSuffix;

  // Check whether we have existing session state, and, if so, whether it's
  // for the session that's named in "streamName".  (Note that we don't
  // support more than one concurrent session on the same client connection.) #####
  if (fOurServerMediaSession != NULL
      && strcmp(streamName, fOurServerMediaSession->streamName()) != 0) {
    fOurServerMediaSession = NULL;
  }
  if (fOurServerMediaSession == NULL) {
    // Set up this session's state.

    // Look up the "ServerMediaSession" object for the specified stream:
    if (streamName[0] != '\0' ||
	fOurServer.lookupServerMediaSession("") != NULL) { // normal case
    } else { // weird case: there was no track id in the URL
      streamName = urlSuffix;
      trackId = NULL;
    }
    fOurServerMediaSession = fOurServer.lookupServerMediaSession(streamName);
    if (fOurServerMediaSession == NULL) {
      handleCmd_notFound(cseq);
      return;
    }

    fOurServerMediaSession->incrementReferenceCount();

    // Set up our array of states for this session's subsessions (tracks):
    reclaimStreamStates();
    ServerMediaSubsessionIterator iter(*fOurServerMediaSession);
    for (fNumStreamStates = 0; iter.next() != NULL; ++fNumStreamStates) {}
    fStreamStates = new struct streamState[fNumStreamStates];
    iter.reset();
    ServerMediaSubsession* subsession;
    for (unsigned i = 0; i < fNumStreamStates; ++i) {
      subsession = iter.next();
      fStreamStates[i].subsession = subsession;
      fStreamStates[i].streamToken = NULL; // for now; reset by SETUP later
    }
  }

  // Look up information for the specified subsession (track):
  ServerMediaSubsession* subsession = NULL;
  unsigned streamNum;
  if (trackId != NULL) { // normal case
    for (streamNum = 0; streamNum < fNumStreamStates; ++streamNum) {
      subsession = fStreamStates[streamNum].subsession;
      if (subsession != NULL && strcmp(trackId, subsession->trackId()) == 0) break;
    }
    if (streamNum >= fNumStreamStates) {
      // The specified track id doesn't exist, so this request fails:
      handleCmd_notFound(cseq);
      return;
    }
  } else {
    // Weird case: there was no track id in the URL.
    // This works only if we have only one subsession:
    if (fNumStreamStates != 1) {
      handleCmd_bad(cseq);
      return;
    }
    streamNum = 0;
    subsession = fStreamStates[streamNum].subsession;
  }
  // ASSERT: subsession != NULL

  // Look for a "Transport:" header in the request string,
  // to extract client parameters:
  StreamingMode streamingMode;
  char* streamingModeString; // set when RAW_UDP streaming is specified
  char* clientsDestinationAddressStr;
  u_int8_t clientsDestinationTTL;
  portNumBits clientRTPPortNum, clientRTCPPortNum;
  unsigned char rtpChannelId, rtcpChannelId;
  parseTransportHeader(fullRequestStr, streamingMode, streamingModeString,
		       clientsDestinationAddressStr, clientsDestinationTTL,
		       clientRTPPortNum, clientRTCPPortNum,
		       rtpChannelId, rtcpChannelId);
  if (streamingMode == RTP_TCP && rtpChannelId == 0xFF) {
    // TCP streaming was requested, but with no "interleaving=" fields.
    // (QuickTime Player sometimes does this.)  Set the RTP and RTCP channel ids to
    // proper values:
    rtpChannelId = fTCPStreamIdCount; rtcpChannelId = fTCPStreamIdCount+1;
  }
  fTCPStreamIdCount += 2;

  Port clientRTPPort(clientRTPPortNum);
  Port clientRTCPPort(clientRTCPPortNum);

  // Next, check whether a "Range:" header is present in the request.
  // This isn't legal, but some clients do this to combine "SETUP" and "PLAY":
  float rangeStart, rangeEnd;
  fStreamAfterSETUP = parseRangeHeader(fullRequestStr, rangeStart, rangeEnd);

  // Then, get server parameters from the 'subsession':
  int tcpSocketNum = streamingMode == RTP_TCP ? fClientSocket : -1;
  netAddressBits destinationAddress = 0;
  u_int8_t destinationTTL = 255;
#ifdef RTSP_ALLOW_CLIENT_DESTINATION_SETTING
  if (clientsDestinationAddressStr != NULL) {
    // Use the client-provided "destination" address.
    // Note: This potentially allows the server to be used in denial-of-service
    // attacks, so don't enable this code unless you're sure that clients are
    // trusted.
    destinationAddress = our_inet_addr(clientsDestinationAddressStr);
  }
  // Also use the client-provided TTL.
  destinationTTL = clientsDestinationTTL;
#endif
  delete[] clientsDestinationAddressStr;
  Boolean isMulticast;
  Port serverRTPPort(0);
  Port serverRTCPPort(0);
  subsession->getStreamParameters(fOurSessionId, fClientAddr.sin_addr.s_addr,
				  clientRTPPort, clientRTCPPort,
				  tcpSocketNum, rtpChannelId, rtcpChannelId,
				  destinationAddress, destinationTTL, isMulticast,
				  serverRTPPort, serverRTCPPort,
				  fStreamStates[streamNum].streamToken);
  struct in_addr destinationAddr; destinationAddr.s_addr = destinationAddress;
  if (isMulticast) {
    if (streamingMode == RTP_TCP) {
      // multicast streams can't be sent via TCP
      handleCmd_unsupportedTransport(cseq);
      return;
    }
    snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	     "RTSP/1.0 200 OK\r\n"
	     "CSeq: %s\r\n"
	     "%s"
	     "Transport: RTP/AVP;multicast;destination=%s;port=%d;ttl=%d\r\n"
	     "Session: %d\r\n\r\n",
	     cseq,
	     dateHeader(),
	     our_inet_ntoa(destinationAddr), ntohs(serverRTPPort.num()), destinationTTL,
	     fOurSessionId);
  } else {
    switch (streamingMode) {
    case RTP_UDP: {
      snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	       "RTSP/1.0 200 OK\r\n"
	       "CSeq: %s\r\n"
	       "%s"
	       "Transport: RTP/AVP;unicast;destination=%s;client_port=%d-%d;server_port=%d-%d\r\n"
	       "Session: %d\r\n\r\n",
	       cseq,
	       dateHeader(),
	       our_inet_ntoa(destinationAddr), ntohs(clientRTPPort.num()), ntohs(clientRTCPPort.num()), ntohs(serverRTPPort.num()), ntohs(serverRTCPPort.num()),
	       fOurSessionId);
      break;
    }
    case RTP_TCP: {
      snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	       "RTSP/1.0 200 OK\r\n"
	       "CSeq: %s\r\n"
	       "%s"
	       "Transport: RTP/AVP/TCP;unicast;destination=%s;interleaved=%d-%d\r\n"
	       "Session: %d\r\n\r\n",
	       cseq,
	       dateHeader(),
	       our_inet_ntoa(destinationAddr), rtpChannelId, rtcpChannelId,
	       fOurSessionId);
      break;
    }
    case RAW_UDP: {
      snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	       "RTSP/1.0 200 OK\r\n"
	       "CSeq: %s\r\n"
	       "%s"
	       "Transport: %s;unicast;destination=%s;client_port=%d;server_port=%d\r\n"
	       "Session: %d\r\n\r\n",
	       cseq,
	       dateHeader(),
	       streamingModeString, our_inet_ntoa(destinationAddr), ntohs(clientRTPPort.num()), ntohs(serverRTPPort.num()),
	       fOurSessionId);
      delete[] streamingModeString;
      break;
    }
    }
  }
}

void RTSPServer::RTSPClientSession
::handleCmd_withinSession(char const* cmdName,
			  char const* urlPreSuffix, char const* urlSuffix,
			  char const* cseq, char const* fullRequestStr) {
  // This will either be:
  // - a non-aggregated operation, if "urlPreSuffix" is the session (stream)
  //   name and "urlSuffix" is the subsession (track) name, or
  // - a aggregated operation, if "urlSuffix" is the session (stream) name,
  //   or "urlPreSuffix" is the session (stream) name, and "urlSuffix"
  //   is empty.
  // First, figure out which of these it is:
  if (fOurServerMediaSession == NULL) { // There wasn't a previous SETUP!
    handleCmd_notSupported(cseq);
    return;
  }
  ServerMediaSubsession* subsession;
  if (urlSuffix[0] != '\0' &&
      strcmp(fOurServerMediaSession->streamName(), urlPreSuffix) == 0) {
    // Non-aggregated operation.
    // Look up the media subsession whose track id is "urlSuffix":
    ServerMediaSubsessionIterator iter(*fOurServerMediaSession);
    while ((subsession = iter.next()) != NULL) {
      if (strcmp(subsession->trackId(), urlSuffix) == 0) break; // success
    }
    if (subsession == NULL) { // no such track!
      handleCmd_notFound(cseq);
      return;
    }
  } else if (strcmp(fOurServerMediaSession->streamName(), urlSuffix) == 0 ||
	     strcmp(fOurServerMediaSession->streamName(), urlPreSuffix) == 0) {
    // Aggregated operation
    subsession = NULL;
  } else { // the request doesn't match a known stream and/or track at all!
    handleCmd_notFound(cseq);
    return;
  }

  if (strcmp(cmdName, "TEARDOWN") == 0) {
    handleCmd_TEARDOWN(subsession, cseq);
  } else if (strcmp(cmdName, "PLAY") == 0) {
    handleCmd_PLAY(subsession, cseq, fullRequestStr);
  } else if (strcmp(cmdName, "PAUSE") == 0) {
    handleCmd_PAUSE(subsession, cseq);
  } else if (strcmp(cmdName, "GET_PARAMETER") == 0) {
    handleCmd_GET_PARAMETER(subsession, cseq, fullRequestStr);
  }
}

void RTSPServer::RTSPClientSession
::handleCmd_TEARDOWN(ServerMediaSubsession* /*subsession*/, char const* cseq) {
  snprintf((char*)fResponseBuffer, sizeof fResponseBuffer,
	   "RTSP/1.0 200 OK\r\nCSeq: %s\r\n%s\r\n",
	   cseq, dateHeader());
  fSessionIsActive = False; // triggers deletion of ourself after responding
}

static Boolean parseScaleHeader(char const* buf, float& scale) {
  // Initialize the result parameter to a default value:
  scale = 1.0;

  // First, find "Scale:"
  while (1) {
    if (*buf == '\0') return False; // not found
    if (_strncasecmp(buf, "Scale: ", 7) == 0) break;
    ++buf;
  }

  // Then, run through each of the fields, looking for ones we handle:
  char const* fields = buf + 7;
  while (*fields == ' ') ++fields;
  float sc;
  if (sscanf(fields, "%f", &sc) == 1) {
    scale = sc;
  } else {
    return False; // The header is malformed
  }

  return True;
}

void RTSPServer::RTSPClientSession
  ::handleCmd_PLAY(ServerMediaSubsession* subsession, char const* cseq,
		   char const* fullRequestStr) {
  char* rtspURL = fOurServer.rtspURL(fOurServerMediaSession);
  unsigned rtspURLSize = strlen(rtspURL);

  //// Parse the client's "Scale:" header, if any: 
  float scale;
  Boolean sawScaleHeader = parseScaleHeader(fullRequestStr, scale);