extract streaming packet fields

Streaming.cpp

@@ -31,26 +31,12 @@ namespace stream
 		
 	void Stream::HandleNextPacket (Packet * packet)
 	{
-		const uint8_t * buf = packet->buf;
-		buf += 4; // sendStreamID
 		if (!m_SendStreamID)
-			m_SendStreamID = be32toh (*(uint32_t *)buf);
+			m_SendStreamID = packet->GetReceiveStreamID ();
-		buf += 4; // receiveStreamID	
-		uint32_t receivedSeqn = be32toh (*(uint32_t *)buf);
-		buf += 4; // sequenceNum
-		buf += 4; // ackThrough
-		int nackCount = buf[0];
-		buf++; // NACK count
-		buf += 4*nackCount; // NACKs
-		buf++; // resendDelay 
-		uint16_t flags = be16toh (*(uint16_t *)buf);
-		buf += 2; // flags
-		uint16_t optionalSize = be16toh (*(uint16_t *)buf);	
-		buf += 2; // optional size
-		const uint8_t * optionalData = buf;
-		buf += optionalSize;
 		
 		// process flags
+		uint16_t flags = packet->GetFlags ();
+		const uint8_t * optionData = packet->GetOptionData ();
 		if (flags & PACKET_FLAG_SYNCHRONIZE)
 		{
 			LogPrint ("Synchronize");
@@ -59,21 +45,21 @@ namespace stream
 		if (flags & PACKET_FLAG_SIGNATURE_INCLUDED)
 		{
 			LogPrint ("Signature");
-			optionalData += 40;
+			optionData += 40;
 		}	
 
 		if (flags & PACKET_FLAG_FROM_INCLUDED)
 		{
 			LogPrint ("From identity");
-			optionalData += sizeof (i2p::data::Identity);
+			optionData += sizeof (i2p::data::Identity);
 		}	
 		
-		// we have reached payload section
+		uint32_t receivedSeqn = packet->GetSeqn ();
 		LogPrint ("seqn=", receivedSeqn, ", flags=", flags); 
 		if (!receivedSeqn || receivedSeqn == m_LastReceivedSequenceNumber + 1)
 		{			
 			// we have received next message
-			packet->offset = buf - packet->buf;
+			packet->offset = packet->GetPayload () - packet->buf;
 			if (packet->GetLength () > 0)
 				m_ReceiveQueue.Put (packet);
 			else
@@ -85,12 +71,12 @@ namespace stream
 			// we should also try stored messages if any
 			for (auto it = m_SavedPackets.begin (); it != m_SavedPackets.end ();)
 			{			
-				if ((*it)->GetReceivedSeqn () == m_LastReceivedSequenceNumber + 1)
+				if ((*it)->GetSeqn () == m_LastReceivedSequenceNumber + 1)
 				{
 					Packet * packet = *it;
 					m_SavedPackets.erase (it++);
 
-					LogPrint ("Process saved packet seqn=", packet->GetReceivedSeqn ());
+					LogPrint ("Process saved packet seqn=", packet->GetSeqn ());
 					if (packet->GetLength () > 0)
 						m_ReceiveQueue.Put (packet);
 					else

Streaming.h

@@ -40,14 +40,23 @@ namespace stream
 		uint8_t * GetBuffer () { return buf + offset; };
 		size_t GetLength () const { return len - offset; };
 
-		uint32_t GetReceivedSeqn () const { return be32toh (*(uint32_t *)(buf + 8)); };
+		uint32_t GetSendStreamID () const { return be32toh (*(uint32_t *)buf); };
+		uint32_t GetReceiveStreamID () const { return be32toh (*(uint32_t *)(buf + 4)); };
+		uint32_t GetSeqn () const { return be32toh (*(uint32_t *)(buf + 8)); };
+		uint32_t GetAckThrough () const { return be32toh (*(uint32_t *)(buf + 12)); };
+		uint8_t GetNACKCount () const { return buf[16]; };
+		const uint8_t * GetOption () const { return buf + 17 + GetNACKCount ()*4 + 3; }; // 3 = resendDelay + flags
+		uint16_t GetFlags () const { return be16toh (*(uint16_t *)(GetOption () - 2)); };
+		uint16_t GetOptionSize () const { return be16toh (*(uint16_t *)GetOption ()); };
+		const uint8_t * GetOptionData () const { return GetOption () + 2; };
+		const uint8_t * GetPayload () const { return GetOptionData () + GetOptionSize (); };
 	};	
 
 	struct PacketCmp
 	{
 		bool operator() (const Packet * p1, const Packet * p2) const
   		{	
-			return p1->GetReceivedSeqn () < p2->GetReceivedSeqn (); 
+			return p1->GetSeqn () < p2->GetSeqn (); 
 		};
 	};