/** Implements notification in order to track socket state. */
@Override
public synchronized void onSctpNotification(SctpSocket socket, SctpNotification notification) {
if (logger.isDebugEnabled()) {
logger.debug("socket=" + socket + "; notification=" + notification);
}
switch (notification.sn_type) {
case SctpNotification.SCTP_ASSOC_CHANGE:
SctpNotification.AssociationChange assocChange =
(SctpNotification.AssociationChange) notification;
switch (assocChange.state) {
case SctpNotification.AssociationChange.SCTP_COMM_UP:
if (!assocIsUp) {
boolean wasReady = isReady();
assocIsUp = true;
if (isReady() && !wasReady) notifySctpConnectionReady();
}
break;
case SctpNotification.AssociationChange.SCTP_COMM_LOST:
case SctpNotification.AssociationChange.SCTP_SHUTDOWN_COMP:
case SctpNotification.AssociationChange.SCTP_CANT_STR_ASSOC:
try {
closeStream();
} catch (IOException e) {
logger.error("Error closing SCTP socket", e);
}
break;
}
break;
}
}
/**
* Sends acknowledgment for open channel request on given SCTP stream ID.
*
* @param sid SCTP stream identifier to be used for sending ack.
*/
private void sendOpenChannelAck(int sid) throws IOException {
// Send ACK
byte[] ack = MSG_CHANNEL_ACK_BYTES;
int sendAck = sctpSocket.send(ack, true, sid, WEB_RTC_PPID_CTRL);
if (sendAck != ack.length) {
logger.error("Failed to send open channel confirmation");
}
}
/**
* {@inheritDoc}
*
* <p>SCTP input data callback.
*/
@Override
public void onSctpPacket(
byte[] data, int sid, int ssn, int tsn, long ppid, int context, int flags) {
if (ppid == WEB_RTC_PPID_CTRL) {
// Channel control PPID
try {
onCtrlPacket(data, sid);
} catch (IOException e) {
logger.error("IOException when processing ctrl packet", e);
}
} else if (ppid == WEB_RTC_PPID_STRING || ppid == WEB_RTC_PPID_BIN) {
WebRtcDataStream channel;
synchronized (this) {
channel = channels.get(sid);
}
if (channel == null) {
logger.error("No channel found for sid: " + sid);
return;
}
if (ppid == WEB_RTC_PPID_STRING) {
// WebRTC String
String str;
String charsetName = "UTF-8";
try {
str = new String(data, charsetName);
} catch (UnsupportedEncodingException uee) {
logger.error("Unsupported charset encoding/name " + charsetName, uee);
str = null;
}
channel.onStringMsg(str);
} else {
// WebRTC Binary
channel.onBinaryMsg(data);
}
} else {
logger.warn("Got message on unsupported PPID: " + ppid);
}
}
/**
* Handles control packet.
*
* @param data raw packet data that arrived on control PPID.
* @param sid SCTP stream id on which the data has arrived.
*/
private synchronized void onCtrlPacket(byte[] data, int sid) throws IOException {
ByteBuffer buffer = ByteBuffer.wrap(data);
int messageType = /* 1 byte unsigned integer */ 0xFF & buffer.get();
if (messageType == MSG_CHANNEL_ACK) {
if (logger.isDebugEnabled()) {
logger.debug(getEndpoint().getID() + " ACK received SID: " + sid);
}
// Open channel ACK
WebRtcDataStream channel = channels.get(sid);
if (channel != null) {
// Ack check prevents from firing multiple notifications
// if we get more than one ACKs (by mistake/bug).
if (!channel.isAcknowledged()) {
channel.ackReceived();
notifyChannelOpened(channel);
} else {
logger.warn("Redundant ACK received for SID: " + sid);
}
} else {
logger.error("No channel exists on sid: " + sid);
}
} else if (messageType == MSG_OPEN_CHANNEL) {
int channelType = /* 1 byte unsigned integer */ 0xFF & buffer.get();
int priority = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
long reliability = /* 4 bytes unsigned integer */ 0xFFFFFFFFL & buffer.getInt();
int labelLength = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
int protocolLength = /* 2 bytes unsigned integer */ 0xFFFF & buffer.getShort();
String label;
String protocol;
if (labelLength == 0) {
label = "";
} else {
byte[] labelBytes = new byte[labelLength];
buffer.get(labelBytes);
label = new String(labelBytes, "UTF-8");
}
if (protocolLength == 0) {
protocol = "";
} else {
byte[] protocolBytes = new byte[protocolLength];
buffer.get(protocolBytes);
protocol = new String(protocolBytes, "UTF-8");
}
if (logger.isDebugEnabled()) {
logger.debug(
"!!! "
+ getEndpoint().getID()
+ " data channel open request on SID: "
+ sid
+ " type: "
+ channelType
+ " prio: "
+ priority
+ " reliab: "
+ reliability
+ " label: "
+ label
+ " proto: "
+ protocol);
}
if (channels.containsKey(sid)) {
logger.error("Channel on sid: " + sid + " already exists");
}
WebRtcDataStream newChannel = new WebRtcDataStream(sctpSocket, sid, label, true);
channels.put(sid, newChannel);
sendOpenChannelAck(sid);
notifyChannelOpened(newChannel);
} else {
logger.error("Unexpected ctrl msg type: " + messageType);
}
}