/**
* we have a packet that belongs to the passed in connection. process the packet for the
* connection. It returns true if the connection is open and the packet was a data packet
*/
boolean processExistingConnection(RDPConnection con, RDPPacket packet) {
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: con state=" + con + ", packet=" + packet);
packetCounter.add();
int state = con.getState();
if (state == RDPConnection.LISTEN) {
// something is wrong, we shouldn't be here
// we get to this method after looking in the connections map
// but all LISTEN connections should be listed direct
// from serversockets
Log.error("RDPServer.processExistingConnection: connection shouldnt be in LISTEN state");
return false;
}
if (state == RDPConnection.SYN_SENT) {
if (!packet.isAck()) {
Log.warn("got a non-ack packet when we're in SYN_SENT");
return false;
}
if (!packet.isSyn()) {
Log.warn("got a non-syn packet when we're in SYN_SENT");
return false;
}
if (Log.loggingNet) Log.net("good: got syn-ack packet in syn_sent");
// make sure its acking our initial segment #
if (packet.getAckNum() != con.getInitialSendSeqNum()) {
if (Log.loggingNet) Log.net("syn's ack number does not match initial seq #");
return false;
}
con.setRcvCur(packet.getSeqNum());
con.setRcvIrs(packet.getSeqNum());
con.setMaxSendUnacks(packet.getSendUnacks());
con.setMaxReceiveSegmentSize(packet.getMaxRcvSegmentSize());
con.setSendUnackd(packet.getAckNum() + 1);
// ack first before setting state to open
// otherwise some other thread will get woken up and send data
// before we send the ack
if (Log.loggingNet) Log.net("new connection state: " + con);
RDPPacket replyPacket = new RDPPacket(con);
con.sendPacketImmediate(replyPacket, false);
con.setState(RDPConnection.OPEN);
return false;
}
if (state == RDPConnection.SYN_RCVD) {
if (packet.getSeqNum() <= con.getRcvIrs()) {
Log.error("seqnum is not above rcv initial seq num");
return false;
}
if (packet.getSeqNum() > (con.getRcvCur() + (con.getRcvMax() * 2))) {
Log.error("seqnum is too big");
return false;
}
if (packet.isAck()) {
if (packet.getAckNum() == con.getInitialSendSeqNum()) {
if (Log.loggingNet) Log.net("got ack for our syn - setting state to open");
con.setState(RDPConnection.OPEN); // this will notify()
// call the accept callback
// first find the serversocket
DatagramChannel dc = con.getDatagramChannel();
if (dc == null) {
throw new MVRuntimeException(
"RDPServer.processExistingConnection: no datagramchannel for connection that just turned OPEN");
}
RDPServerSocket rdpSocket = RDPServer.getRDPSocket(dc);
if (rdpSocket == null) {
throw new MVRuntimeException(
"RDPServer.processExistingConnection: no socket for connection that just turned OPEN");
}
ClientConnection.AcceptCallback acceptCB = rdpSocket.getAcceptCallback();
if (acceptCB != null) {
acceptCB.acceptConnection(con);
} else {
Log.warn("serversocket has no accept callback");
}
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: got ACK, removing from unack list: "
+ packet.getSeqNum());
con.removeUnackPacket(packet.getSeqNum());
}
}
}
if (state == RDPConnection.CLOSE_WAIT) {
// reply with a reset on all packets
if (!packet.isRst()) {
RDPPacket rstPacket = RDPPacket.makeRstPacket();
con.sendPacketImmediate(rstPacket, false);
}
}
if (state == RDPConnection.OPEN) {
if (packet.isRst()) {
// the other side wants to close the connection
// set the state,
// dont call con.close() since that will send a reset packet
if (Log.loggingDebug)
Log.debug("RDPServer.processExistingConnection: got reset packet for con " + con);
if (con.getState() != RDPConnection.CLOSE_WAIT) {
con.setState(RDPConnection.CLOSE_WAIT);
con.setCloseWaitTimer();
// Only invoke callback when moving into CLOSE_WAIT
// state. This prevents two calls to connectionReset.
Log.net("RDPServer.processExistingConnection: calling reset callback");
ClientConnection.MessageCallback pcb = con.getCallback();
pcb.connectionReset(con);
}
return false;
}
if (packet.isSyn()) {
// this will close the connection (put into CLOSE_WAIT)
// send a reset packet and call the connectionReset callback
Log.error(
"RDPServer.processExistingConnection: closing connection because we got a syn packet, con="
+ con);
con.close();
return false;
}
// TODO: shouldnt it be ok for it to have same seq num?
// if it is a 0 data packet?
long rcvCur = con.getRcvCur();
if (packet.getSeqNum() <= rcvCur) {
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: seqnum too small - acking/not process");
if (packet.getData() != null) {
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: sending ack even though seqnum out of range");
RDPPacket replyPacket = new RDPPacket(con);
con.sendPacketImmediate(replyPacket, false);
}
return false;
}
if (packet.getSeqNum() > (rcvCur + (con.getRcvMax() * 2))) {
Log.error("RDPServer.processExistingConnection: seqnum too big - discarding");
return false;
}
if (packet.isAck()) {
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: processing ack " + packet.getAckNum());
// lock for race condition (read then set)
con.getLock().lock();
try {
if (packet.getAckNum() >= con.getSendNextSeqNum()) {
// acking something we didnt even send yet
Log.error(
"RDPServer.processExistingConnection: discarding -- got ack #"
+ packet.getAckNum()
+ ", but our next send seqnum is "
+ con.getSendNextSeqNum()
+ " -- "
+ con);
return false;
}
if (con.getSendUnackd() <= packet.getAckNum()) {
con.setSendUnackd(packet.getAckNum() + 1);
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: updated send_unackd num to "
+ con.getSendUnackd()
+ " (one greater than packet ack) - "
+ con);
con.removeUnackPacketUpTo(packet.getAckNum());
}
if (packet.isEak()) {
List eackList = packet.getEackList();
Iterator iter = eackList.iterator();
while (iter.hasNext()) {
Long seqNum = (Long) iter.next();
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: got EACK: " + seqNum);
con.removeUnackPacket(seqNum.longValue());
}
}
} finally {
con.getLock().unlock();
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: processed ack " + packet.getAckNum());
}
}
// process the data
byte[] data = packet.getData();
if ((data != null) || packet.isNul()) {
dataCounter.add();
// lock - since racecondition: we read then set
con.getLock().lock();
try {
rcvCur = con.getRcvCur(); // update rcvCur
if (Log.loggingNet) Log.net("RDPServer.processExistingConnection: rcvcur is " + rcvCur);
ClientConnection.MessageCallback pcb = con.getCallback();
if (pcb == null) {
Log.warn("RDPServer.processExistingConnection: no packet callback registered");
}
// call callback only if we havent seen it already - eackd
if (!con.hasEack(packet.getSeqNum())) {
if (con.isSequenced()) {
// this is a sequential connection,
// make sure this is the 'next' packet
// is this the next sequential packet
if (packet.getSeqNum() == (rcvCur + 1)) {
// this is the next packet
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: conn is sequenced and received next packet, rcvCur="
+ rcvCur
+ ", packet="
+ packet);
if ((pcb != null) && (data != null)) {
queueForCallbackProcessing(pcb, con, packet);
}
} else {
// not the next packet, place it in queue
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: conn is sequenced, BUT PACKET is OUT OF ORDER: rcvcur="
+ rcvCur
+ ", packet="
+ packet);
con.addSequencePacket(packet);
}
} else {
if ((pcb != null) && (data != null)) {
// make sure we havent already processed packet
queueForCallbackProcessing(pcb, con, packet);
}
}
} else {
if (Log.loggingNet) Log.net(con.toString() + " already seen this packet");
}
// is this the next sequential packet
if (packet.getSeqNum() == (rcvCur + 1)) {
con.setRcvCur(rcvCur + 1);
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection RCVD: incremented last sequenced rcvd: "
+ (rcvCur + 1));
// packet in order - dont add to eack
// Take any additional sequential packets off eack
long seqNum = rcvCur + 2;
while (con.removeEack(seqNum)) {
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: removing/collapsing eack: " + seqNum);
con.setRcvCur(seqNum++);
}
if (con.isSequenced()) {
rcvCur++; // since we just process the last one
Log.net(
"RDPServer.processExistingConnection: connection is sequenced, processing collapsed packets.");
// send any saved sequential packets also
Iterator iter = con.getSequencePackets().iterator();
while (iter.hasNext()) {
RDPPacket p = (RDPPacket) iter.next();
if (Log.loggingNet)
Log.net(
"rdpserver: stored packet seqnum="
+ p.getSeqNum()
+ ", if equal to (rcvcur + 1)="
+ (rcvCur + 1));
if (p.getSeqNum() == (rcvCur + 1)) {
Log.net(
"RDPServer.processExistingConnection: this is the next packet, processing");
// this is the next packet - update rcvcur
rcvCur++;
// process this packet
Log.net(
"RDPServer.processExistingConnection: processing stored sequential packet "
+ p);
byte[] storedData = p.getData();
if (pcb != null && storedData != null) {
queueForCallbackProcessing(pcb, con, packet);
}
iter.remove();
}
}
} else {
if (Log.loggingNet)
Log.net("RDPServer.processExistingConnection: connection is not sequenced");
}
} else {
if (Log.loggingNet)
Log.net(
"RDPServer.processExistingConnection: RCVD OUT OF ORDER: packet seq#: "
+ packet.getSeqNum()
+ ", but last sequential rcvd packet was: "
+ con.getRcvCur()
+ " -- not incrementing counter");
if (packet.getSeqNum() > rcvCur) {
// must be at least + 2 larger than rcvCur
if (Log.loggingNet) Log.net("adding to eack list " + packet);
con.addEack(packet);
}
}
} finally {
con.getLock().unlock();
}
return true;
}
}
return false;
}