properly handle data frames with sequence numbers

1 files changed, 45 insertions, 4 deletions

diff --git a/sapsocket.cc b/sapsocket.cc
index ce85c0c..472865c 100644
--- a/sapsocket.cc
+++ b/sapsocket.cc
@@ -4,8 +4,9 @@
 #include "sapconnection.h"
 #include "sapsocket.h"
 
-SAPSocket::SAPSocket(SAPConnection *conn, int sessionId) :
-    QObject(conn), _sessionId(sessionId), _open(false)
+SAPSocket::SAPSocket(SAPConnection *conn, int sessionId, const SAPChannelInfo &chanInfo) :
+	QObject(conn), _sessionId(sessionId), _info(chanInfo), _open(false),
+	_seqNum(0), _expectedSeqNum(0)
 {
 }
 
@@ -19,6 +20,11 @@ SAPConnection * SAPSocket::connection()
 	return static_cast<SAPConnection*>(parent());
 }
 
+SAPChannelInfo SAPSocket::channelInfo() const
+{
+	return _info;
+}
+
 bool SAPSocket::isOpen() const
 {
 	return _open;
@@ -40,7 +46,18 @@ QByteArray SAPSocket::receive()
 
 bool SAPSocket::send(const QByteArray &data)
 {
-	return peer()->writeToSession(_sessionId, data);
+	SAProtocol::DataFrame frame;
+
+	frame.withSeqNum = isWithSeqNum();
+	if (isReliable()) {
+		frame.seqNum = _seqNum++;
+	} else {
+		frame.seqNum = 0;
+	}
+	frame.unk_1 = 0;
+	frame.data = data;
+
+	return peer()->writeToSession(_sessionId, SAProtocol::packDataFrame(frame));
 }
 
 void SAPSocket::setOpen(bool open)
@@ -51,7 +68,20 @@ void SAPSocket::setOpen(bool open)
 void SAPSocket::acceptIncomingData(const QByteArray &data)
 {
 	if (data.isEmpty()) return;
-	_in.enqueue(data);
+	SAProtocol::DataFrame frame = SAProtocol::unpackDataFrame(data, isWithSeqNum());
+
+	if (isReliable()) {
+		if (frame.seqNum != _expectedSeqNum) {
+			qWarning() << "Unexpected sequence number" << frame.seqNum
+					   << "on session" << _sessionId
+					   << "(expected " << _expectedSeqNum << ")";
+		}
+		_expectedSeqNum = frame.seqNum + 1;
+
+		// TODO Do we actually need to ack this somehow?
+	}
+
+	_in.enqueue(frame.data);
 
 	emit messageReceived();
 }
@@ -60,3 +90,14 @@ int SAPSocket::sessionId() const
 {
 	return _sessionId;
 }
+
+bool SAPSocket::isReliable() const
+{
+	return _info.qosType() == SAPChannelInfo::QoSReliabilityEnable;
+}
+
+bool SAPSocket::isWithSeqNum() const
+{
+	return _info.qosType() == SAPChannelInfo::QoSReliabilityDisable ||
+		   _info.qosType() == SAPChannelInfo::QoSReliabilityEnable;
+}