Add tests for TAP sockets & bridge_and_sniff()

.appveyor.yml

@@ -29,7 +29,7 @@ test_script:
   - 'del test\regression.uts'
 
   # Secondary and contrib unit tests
-  - 'del test\bpf.uts test\linux.uts' # Don't bother with OS dependent regression tests
+  - 'del test\bpf.uts test\linux.uts test\sendsniff.uts' # Don't bother with OS dependent regression tests
   - "%PYTHON%\\python -m coverage run --parallel-mode bin\\UTscapy -c test\\configs\\windows.utsc || exit /b 42"
   
   # TLS unit tests

test/sendsniff.uts

@@ -0,0 +1,75 @@
+% send, sniff, sr* tests for Scapy
+
+~ netaccess
+
+############
+############
++ Bridge using tap interfaces
+
+~ tap linux
+
+= Create two tap interfaces
+tap0, tap1 = [TunTapInterface("tap%d" % i, create=True) for i in range(2)]
+from threading import Thread
+
+= Run a sniff thread on the tap1 **interface**
+t_sniff = Thread(
+    target=sniff,
+    kwargs={"iface": "tap1", "count": 5, "prn": Packet.summary,
+	    "lfilter": lambda p: IP in p and p[IP].src == "1.2.3.4"}
+)
+t_sniff.start()
+
+= Run a bridge_and_sniff thread between the taps **sockets**
+t_bridge = Thread(target=bridge_and_sniff, args=(tap0, tap1),
+                  kwargs={"store": False, "count": 5, 'prn': Packet.summary,
+                          "lfilter": lambda p: IP in p and p[IP].src == "1.2.3.4"})
+t_bridge.start()
+
+= Send five packets to the tap0 **interface**
+time.sleep(1)
+sendp([Ether(dst=ETHER_BROADCAST) / IP(src="1.2.3.4") / ICMP()], iface="tap0",
+      count=5)
+
+= Wait for the threads
+t_bridge.join()
+t_sniff.join()
+
+# Same tests, with "NAT" using xfrm function
+
+= Run a sniff thread on the tap1 **interface**
+t_sniff = Thread(
+    target=sniff,
+    kwargs={"iface": "tap1", "count": 5, "prn": Packet.summary,
+	    "lfilter": lambda p: IP in p and p[IP].src == "2.3.4.5"}
+)
+t_sniff.start()
+
+= Run a bridge_and_sniff thread between the taps **sockets**
+def nat_1_2(pkt):
+    if IP in pkt and pkt[IP].src == "1.2.3.4":
+        pkt[IP].src = "2.3.4.5"
+        del pkt[IP].chksum
+        return pkt
+    return False
+
+t_bridge = Thread(target=bridge_and_sniff, args=(tap0, tap1),
+                  kwargs={"store": False, "count": 5, 'prn': Packet.summary,
+                          "xfrm12": nat_1_2,
+                          "lfilter": lambda p: IP in p and p[IP].src == "1.2.3.4"})
+t_bridge.start()
+
+= Send five packets to the tap0 **interface**
+time.sleep(1)
+sendp([Ether(dst=ETHER_BROADCAST) / IP(src="1.2.3.4") / ICMP()], iface="tap0",
+      count=5)
+
+= Wait for the threads
+t_bridge.join()
+t_sniff.join()
+
+= Delete the tap interfaces
+tap0.close()
+tap1.close()
+tap0.delete()
+tap1.delete()