Ignore unexpected ICMPv6 Neighbor Discovery - Neighbor Solicitation packets

[csit.git] / resources / traffic_scripts / ipv6_ns.py

diff --git a/resources/traffic_scripts/ipv6_ns.py b/resources/traffic_scripts/ipv6_ns.py
index 70c6ab4..5852e63 100755 (executable)
--- a/resources/traffic_scripts/ipv6_ns.py
+++ b/resources/traffic_scripts/ipv6_ns.py
@@ -17,13 +17,18 @@
 
 import sys
 import logging
+
+# pylint: disable=no-name-in-module
+# pylint: disable=import-error
 logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
-from resources.libraries.python.PacketVerifier import RxQueue, TxQueue,\
-    checksum_equal
-from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
+
+from scapy.all import Ether
 from scapy.layers.inet6 import IPv6, ICMPv6ND_NA, ICMPv6ND_NS
 from scapy.layers.inet6 import ICMPv6NDOptDstLLAddr, ICMPv6NDOptSrcLLAddr
-from scapy.all import Ether
+
+from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
+from resources.libraries.python.PacketVerifier import checksum_equal
+from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
 
 
 def main():
@@ -41,57 +46,67 @@ def main():
 
     # send ICMPv6 neighbor solicitation message
     pkt_send = (Ether(src=src_mac, dst='ff:ff:ff:ff:ff:ff') /
-                      IPv6(src=src_ip, dst='ff02::1:ff00:2') /
-                      ICMPv6ND_NS(tgt=dst_ip) /
-                      ICMPv6NDOptSrcLLAddr(lladdr=src_mac))
+                IPv6(src=src_ip, dst='ff02::1:ff00:2') /
+                ICMPv6ND_NS(tgt=dst_ip) /
+                ICMPv6NDOptSrcLLAddr(lladdr=src_mac))
     sent_packets.append(pkt_send)
     txq.send(pkt_send)
 
     # receive ICMPv6 neighbor advertisement message
-    ether = rxq.recv(2, sent_packets)
+    while True:
+        ether = rxq.recv(2, sent_packets)
+        if ether is None:
+            raise RuntimeError('ICMPv6 echo reply Rx timeout')
+
+        if ether.haslayer(ICMPv6ND_NS):
+            # read another packet in the queue if the current one is ICMPv6ND_NS
+            continue
+        else:
+            # otherwise process the current packet
+            break
+
     if ether is None:
         raise RuntimeError('ICMPv6 echo reply Rx timeout')
 
     if not ether.haslayer(IPv6):
-        raise RuntimeError('Unexpected packet with no IPv6 received {0}'.format(
-            ether.__repr__()))
+        raise RuntimeError('Unexpected packet with no IPv6 received {0}'.
+                           format(ether.__repr__()))
 
-    ipv6 = ether['IPv6']
+    ipv6 = ether[IPv6]
 
     if not ipv6.haslayer(ICMPv6ND_NA):
-        raise RuntimeError(
-            'Unexpected packet with no ICMPv6 ND-NA received {0}'.format(
-                ipv6.__repr__()))
+        raise RuntimeError('Unexpected packet with no ICMPv6 ND-NA received '
+                           '{0}'.format(ipv6.__repr__()))
 
-    icmpv6_na = ipv6['ICMPv6 Neighbor Discovery - Neighbor Advertisement']
+    icmpv6_na = ipv6[ICMPv6ND_NA]
 
     # verify target address
     if icmpv6_na.tgt != dst_ip:
-        raise RuntimeError('Invalid target address {0} should be {1}'.format(
-            icmpv6_na.tgt, dst_ip))
+        raise RuntimeError('Invalid target address {0} should be {1}'.
+                           format(icmpv6_na.tgt, dst_ip))
 
     if not icmpv6_na.haslayer(ICMPv6NDOptDstLLAddr):
-        raise RuntimeError(
-            'Missing Destination Link-Layer Address option in ICMPv6 ' +
-            'Neighbor Advertisement {0}'.format(icmpv6_na.__repr__()))
+        raise RuntimeError('Missing Destination Link-Layer Address option in '
+                           'ICMPv6 Neighbor Advertisement {0}'.
+                           format(icmpv6_na.__repr__()))
 
-    option = 'ICMPv6 Neighbor Discovery Option - Destination Link-Layer Address'
-    dst_ll_addr = icmpv6_na[option]
+    dst_ll_addr = icmpv6_na[ICMPv6NDOptDstLLAddr]
 
     # verify destination link-layer address field
     if dst_ll_addr.lladdr != dst_mac:
-        raise RuntimeError('Invalid lladdr {0} should be {1}'.format(
-            dst_ll_addr.lladdr, dst_mac))
+        raise RuntimeError('Invalid lladdr {0} should be {1}'.
+                           format(dst_ll_addr.lladdr, dst_mac))
 
     # verify checksum
     cksum = icmpv6_na.cksum
     del icmpv6_na.cksum
     tmp = ICMPv6ND_NA(str(icmpv6_na))
     if not checksum_equal(tmp.cksum, cksum):
-        raise RuntimeError(
-            'Invalid checksum {0} should be {1}'.format(cksum, tmp.cksum))
+        raise RuntimeError('Invalid checksum {0} should be {1}'.
+                           format(cksum, tmp.cksum))
 
     sys.exit(0)
 
+
 if __name__ == "__main__":
     main()