Support offloading for hardware scapy tests

docs/testing/mellanox.md

@@ -27,7 +27,7 @@ If you set two VMs like this, they should be able to connect to each other (ping
 ### Pytest suite
 As `scapy` cannot directly communicate with VFs, running VMs with two anonymous bridged interfaces are needed. One interface is connected to Mellanox VF using VFIO and the other is a simple TAP device created by KVM. Then dp-service communicates using the VF and test suite uses the TAP device, e.g.
 ```
--net none -device vfio-pci,host=03:00.02 -device e1000,netdev=tap0 -netdev tap,id=tap0,script=no,downscript=no
+qemu-system-x86_64 -enable-kvm -drive media=disk,if=virtio,index=0,file=./kvm/onmetal_tap.qcow2 -m 2G -cpu host -smp 2 -nographic -net none -device vfio-pci,host=03:00.2 -device e1000,netdev=tap2 -netdev tap,id=tap2,script=no,downscript=no
 ```
 
 Tests have been done using basic Debian 11 installation, but any fresh distro should work, just configure interface like this:

test/local/dp_service.py

@@ -24,12 +24,8 @@ def __init__(self, build_path, port_redundancy, fast_flow_timeout,
 		self.hardware = hardware
 
 		if self.hardware:
-			# TODO test without pf1-tap
-			# if self.port_redundancy:
-				# raise ValueError("Port redundancy is not supported when testing on actual hardware")
 			self.reconfigure_tests(DpService.DP_SERVICE_CONF)
 		else:
-			# TODO needs testing
 			if offloading:
 				raise ValueError("Offloading is only possible when testing on actual hardware")
 

test/local/tcp_tester.py

@@ -66,13 +66,17 @@ def reply_tcp(self):
 			self.tcp_receiver_seq += 1
 
 		# Application-level reply
-		if pkt[TCP].payload != None and len(pkt[TCP].payload) > 0:
-			if pkt[TCP].payload == Raw(_TCPTester.TCP_RESET_REQUEST):
+		payload = pkt[TCP].payload
+		if payload != None and len(payload) > 0:
+			if Padding in payload:
+				length = len(payload) - len(payload[Padding])
+				payload = payload.__class__(raw(payload)[0:length])
+			if payload == Raw(_TCPTester.TCP_RESET_REQUEST):
 				reply_pkt = (self.get_server_l3_reply(pkt) /
 							 TCP(dport=pkt[TCP].sport, sport=pkt[TCP].dport, seq=self.tcp_receiver_seq, flags="R"))
 				delayed_sendp(reply_pkt, self.server_tap)
 				return
-			elif pkt[TCP].payload == Raw(_TCPTester.TCP_NORMAL_REQUEST):
+			elif payload == Raw(_TCPTester.TCP_NORMAL_REQUEST):
 				reply_pkt = (self.get_server_l3_reply(pkt) /
 							 TCP(dport=pkt[TCP].sport, sport=pkt[TCP].dport, seq=self.tcp_receiver_seq, flags="") /
 							 Raw(_TCPTester.TCP_NORMAL_RESPONSE))