rtspclient.cpp

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

      + strlen(subsession.sessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    prefix, separator, suffix,
	    ++fCSeq,
	    subsession.sessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "RECORD")) break;

    // Get the response from the server:
    unsigned bytesRead; unsigned responseCode;
    char* firstLine; char* nextLineStart;
    if (!getResponse("RECORD", bytesRead, responseCode, firstLine, nextLineStart)) break;

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::setMediaSessionParameter(MediaSession& /*session*/,
					     char const* parameterName,
					     char const* parameterValue) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progress
    if (fLastSessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the SET_PARAMETER command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator,
				  "SET_PARAMETER", fBaseURL);

    char* const cmdFmt =
      "SET_PARAMETER %s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "%s: %s\r\n"
      "\r\n";

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(fBaseURL)
      + 20 /* max int len */
      + strlen(fLastSessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize
      + strlen(parameterName) + strlen(parameterValue);
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    fBaseURL,
	    ++fCSeq,
	    fLastSessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr,
	    parameterName, parameterValue);
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "SET_PARAMETER")) break;

    // Get the response from the server:
    unsigned bytesRead; unsigned responseCode;
    char* firstLine; char* nextLineStart;
    if (!getResponse("SET_PARAMETER", bytesRead, responseCode, firstLine, nextLineStart)) break;

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::teardownMediaSession(MediaSession& /*session*/) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progreee
    if (fLastSessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the TEARDOWN command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator,
				  "TEARDOWN", fBaseURL);

    char* const cmdFmt =
      "TEARDOWN %s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "\r\n";

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(fBaseURL)
      + 20 /* max int len */
      + strlen(fLastSessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    fBaseURL,
	    ++fCSeq,
	    fLastSessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "TEARDOWN")) break;

    if (fTCPStreamIdCount == 0) { // When TCP streaming, don't look for a response
      // Get the response from the server:
      unsigned bytesRead; unsigned responseCode;
      char* firstLine; char* nextLineStart;
      if (!getResponse("TEARDOWN", bytesRead, responseCode, firstLine, nextLineStart)) break;
      
      delete[] fLastSessionId; fLastSessionId = NULL;
      // we're done with this session
    }
      
    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::teardownMediaSubsession(MediaSubsession& subsession) {
  char* cmd = NULL;
  do {
    // First, make sure that we have a RTSP session in progreee
    if (subsession.sessionId == NULL) {
      envir().setResultMsg(NoSessionErr);
      break;
    }

    // Send the TEARDOWN command:

    // First, construct an authenticator string:
    char* authenticatorStr
      = createAuthenticatorString(&fCurrentAuthenticator,
				  "TEARDOWN", fBaseURL);

    char* const cmdFmt =
      "TEARDOWN %s%s%s RTSP/1.0\r\n"
      "CSeq: %d\r\n"
      "Session: %s\r\n"
      "%s"
      "%s"
      "\r\n";

    char const *prefix, *separator, *suffix;
    constructSubsessionURL(subsession, prefix, separator, suffix);

    unsigned cmdSize = strlen(cmdFmt)
      + strlen(prefix) + strlen(separator) + strlen(suffix)
      + 20 /* max int len */
      + strlen(subsession.sessionId)
      + strlen(authenticatorStr)
      + fUserAgentHeaderStrSize;
    cmd = new char[cmdSize];
    sprintf(cmd, cmdFmt,
	    prefix, separator, suffix,
	    ++fCSeq,
	    subsession.sessionId,
	    authenticatorStr,
	    fUserAgentHeaderStr);
    delete[] authenticatorStr;

    if (!sendRequest(cmd, "TEARDOWN")) break;

    if (fTCPStreamIdCount == 0) { // When TCP streaming, don't look for a response
      // Get the response from the server:
      unsigned bytesRead; unsigned responseCode;
      char* firstLine; char* nextLineStart;
      if (!getResponse("TEARDOWN", bytesRead, responseCode, firstLine, nextLineStart)) break;
    }
      
    delete[] (char*)subsession.sessionId;
    subsession.sessionId = NULL;
    // we're done with this session

    delete[] cmd;
    return True;
  } while (0);

  delete[] cmd;
  return False;
}

Boolean RTSPClient::openConnectionFromURL(char const* url) {
  do {
    // Set this as our base URL:
    delete[] fBaseURL; fBaseURL = strDup(url); if (fBaseURL == NULL) break;

    // Begin by parsing the URL:

    NetAddress destAddress;
    portNumBits urlPortNum;
    char const* urlSuffix;
    if (!parseRTSPURL(envir(), url, destAddress, urlPortNum, &urlSuffix)) break;
    portNumBits destPortNum
      = fTunnelOverHTTPPortNum == 0 ? urlPortNum : fTunnelOverHTTPPortNum;
    
    if (fInputSocketNum < 0) {
      // We don't yet have a TCP socket.  Set one up (blocking) now:
      fInputSocketNum = fOutputSocketNum
	= setupStreamSocket(envir(), 0, False /* =>blocking */);
      if (fInputSocketNum < 0) break;
    
      // Connect to the remote endpoint:
      struct sockaddr_in remoteName;
      remoteName.sin_family = AF_INET;
      remoteName.sin_port = htons(destPortNum);
      remoteName.sin_addr.s_addr = fServerAddress
	= *(unsigned*)(destAddress.data());
      if (connect(fInputSocketNum, (struct sockaddr*)&remoteName, sizeof remoteName)
	  != 0) {
	envir().setResultErrMsg("connect() failed: ");
	break;
      }
      
      if (fTunnelOverHTTPPortNum != 0 && !setupHTTPTunneling(urlSuffix)) break;
    }

    return True; 
  } while (0);

  fDescribeStatusCode = 1;
  resetTCPSockets();
  return False;
}

Boolean RTSPClient::parseRTSPURL(UsageEnvironment& env, char const* url,
				 NetAddress& address,
				 portNumBits& portNum,
				 char const** urlSuffix) {
  do {
    // Parse the URL as "rtsp://<address>:<port>/<etc>"
    // (with ":<port>" and "/<etc>" optional)
    // Also, skip over any "<username>[:<password>]@" preceding <address>
    char const* prefix = "rtsp://";
    unsigned const prefixLength = 7;
    if (_strncasecmp(url, prefix, prefixLength) != 0) {
      env.setResultMsg("URL is not of the form \"", prefix, "\"");
      break;
    }

    unsigned const parseBufferSize = 100;
    char parseBuffer[parseBufferSize];
    char const* from = &url[prefixLength];

    // Skip over any "<username>[:<password>]@"
    char const* from1 = from;
    while (*from1 != '\0' && *from1 != '/') {
      if (*from1 == '@') {
	from = ++from1;
	break;
      }
      ++from1;
    }

    char* to = &parseBuffer[0];
    unsigned i;
    for (i = 0; i < parseBufferSize; ++i) {
      if (*from == '\0' || *from == ':' || *from == '/') {
	// We've completed parsing the address
	*to = '\0';
	break;
      }
      *to++ = *from++;
    }
    if (i == parseBufferSize) {
      env.setResultMsg("URL is too long");
      break;
    }

    NetAddressList addresses(parseBuffer);
    if (addresses.numAddresses() == 0) {
      env.setResultMsg("Failed to find network address for \"",
		       parseBuffer, "\"");
      break;
    }
    address = *(addresses.firstAddress());

    portNum = 554; // default value
    char nextChar = *from;
    if (nextChar == ':') {
      int portNumInt;
      if (sscanf(++from, "%d", &portNumInt) != 1) {
	env.setResultMsg("No port number follows ':'");
	break;
      }
      if (portNumInt < 1 || portNumInt > 65535) {
	env.setResultMsg("Bad port number");
	break;
      }
      portNum = (portNumBits)portNumInt;
      while (*from >= '0' && *from <= '9') ++from; // skip over port number
    }

    // The remainder of the URL is the suffix:
    if (urlSuffix != NULL) *urlSuffix = from;

    return True;
  } while (0);

  return False;
}

Boolean RTSPClient::parseRTSPURLUsernamePassword(char const* url,
						 char*& username,
						 char*& password) {
  username = password = NULL; // by default
  do {
    // Parse the URL as "rtsp://<username>[:<password>]@<whatever>"
    char const* prefix = "rtsp://";
    unsigned const prefixLength = 7;
    if (_strncasecmp(url, prefix, prefixLength) != 0) break;

    // Look for the ':' and '@':
    unsigned usernameIndex = prefixLength;
    unsigned colonIndex = 0, atIndex = 0;
    for (unsigned i = usernameIndex; url[i] != '\0' && url[i] != '/'; ++i) {
      if (url[i] == ':' && colonIndex == 0) {
	colonIndex = i;
      } else if (url[i] == '@') {
	atIndex = i;
	break; // we're done
      }
    }
    if (atIndex == 0) break; // no '@' found

    char* urlCopy = strDup(url);
    urlCopy[atIndex] = '\0';
    if (colonIndex > 0) {
      urlCopy[colonIndex] = '\0';
      password = strDup(&urlCopy[colonIndex+1]);
    } else {
      password = strDup("");
    }
    username = strDup(&urlCopy[usernameIndex]);
    delete[] urlCopy;

    return True;
  } while (0);

  return False;
}

static const char base64Char[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static char* base64Encode(char const* orig) {
  if (orig == NULL) return NULL;

  unsigned const origLength = strlen(orig);
  unsigned const numOrig24BitValues = origLength/3;
  Boolean havePadding = origLength > numOrig24BitValues*3;
  Boolean havePadding2 = origLength == numOrig24BitValues*3 + 2;
  unsigned const numResultBytes = 4*(numOrig24BitValues + havePadding);
  char* result = new char[numResultBytes+1]; // allow for trailing '\0'
  
  // Map each full group of 3 input bytes into 4 output base-64 characters:
  unsigned i;
  for (i = 0; i < numOrig24BitValues; ++i) {
    result[4*i+0] = base64Char[(orig[3*i]>>2)&0x3F];
    result[4*i+1] = base64Char[(((orig[3*i]&0x3)<<4) | (orig[3*i+1]>>4))&0x3F];
    result[4*i+2] = base64Char[((orig[3*i+1]<<2) | (orig[3*i+2]>>6))&0x3F];
    result[4*i+3] = base64Char[orig[3*i+2]&0x3F];
  }

  // Now, take padding into account.  (Note: i == numOrig24BitValues)
  if (havePadding) {
    result[4*i+0] = base64Char[(orig[3*i]>>2)&0x3F];
    result[4*i+1] = base64Char[(((orig[3*i]&0x3)<<4) | (orig[3*i+1]>>4))&0x3F];
    if (havePadding2) {
      result[4*i+2] = base64Char[(orig[3*i+1]<<2)&0x3F];
    } else {
      result[4*i+2] = '=';
    }
    result[4*i+3] = '=';
  }

  result[numResultBytes] = '\0';
  return result;
}

char*
RTSPClient::createAuthenticatorString(Authenticator const* authenticator,
				      char const* cmd, char const* url) {
  if (authenticator != NULL && authenticator->realm() != NULL
      && authenticator->username() != NULL && authenticator->password() != NULL) {
    // We've been provided a filled-in authenticator, so use it:
    char* authenticatorStr;
    if (authenticator->nonce() != NULL) { // Digest authentication
      char* const authFmt =
	"Authorization: Digest username=\"%s\", realm=\"%s\", "
	"nonce=\"%s\", uri=\"%s\", response=\"%s\"\r\n";