Ignore unexpected ICMPv6 Neighbor Discovery - Neighbor Solicitation packets

We need to adapt all functional traffic scripts related to functional
IPv6 tests to ingore receiving of unexpected ICMPv6ND_NS
(ICMPv6 Neighbor Discovery - Neighbor Solicitation) packets that are
sent automatically and we cannot avoid to receive them.

The reason is to prevent false negative test results in case of csit
functional tests that could block creation of new operational branch
(csit weekly jobs), usage of new vpp builds (csit semiweekly jobs)
and merging patches - csit as well as vpp.

Change-Id: I43c90e7c766762fa769a81661338759a11b401a1
Signed-off-by: Jan Gelety <jgelety@cisco.com>

1 files changed, 22 insertions, 11 deletions

diff --git a/resources/traffic_scripts/send_icmp_check_multipath.py b/resources/traffic_scripts/send_icmp_check_multipath.py
index 4e39efdfcd..5da3b7b096 100755
--- a/resources/traffic_scripts/send_icmp_check_multipath.py
+++ b/resources/traffic_scripts/send_icmp_check_multipath.py
@@ -18,10 +18,9 @@ and check if it is divided into two paths."""
 import sys
 import ipaddress
 
-from scapy.layers.inet import ICMP, IP
-from scapy.layers.inet6 import IPv6
 from scapy.all import Ether
-from scapy.layers.inet6 import ICMPv6EchoRequest
+from scapy.layers.inet import ICMP, IP
+from scapy.layers.inet6 import IPv6, ICMPv6EchoRequest, ICMPv6ND_NS
 
 from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
 from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
@@ -94,27 +93,38 @@ def main():
 
         sent_packets.append(pkt_raw)
         txq.send(pkt_raw)
-        ether = rxq.recv(2)
+
+        while True:
+            ether = rxq.recv(2)
+            if ether is None:
+                raise RuntimeError('ICMPv6 echo reply Rx timeout')
+
+            if ether.haslayer(ICMPv6ND_NS):
+                # read another packet in the queue in case of ICMPv6ND_NS packet
+                continue
+            else:
+                # otherwise process the current packet
+                break
 
         if ether is None:
             raise RuntimeError("ICMP echo Rx timeout")
         if not ether.haslayer(ip_format):
-            raise RuntimeError("Not an IP packet received {0}"
-                               .format(ether.__repr__()))
+            raise RuntimeError("Not an IP packet received {0}".
+                               format(ether.__repr__()))
 
-        if ether['Ethernet'].src != dut_if2_mac:
+        if ether[Ether].src != dut_if2_mac:
             raise RuntimeError("Source MAC address error")
 
-        if ether['Ethernet'].dst == path_1_mac:
+        if ether[Ether].dst == path_1_mac:
             path_1_counter += 1
-        elif ether['Ethernet'].dst == path_2_mac:
+        elif ether[Ether].dst == path_2_mac:
             path_2_counter += 1
         else:
             raise RuntimeError("Destination MAC address error")
 
     if (path_1_counter + path_2_counter) != 100:
-        raise RuntimeError("Packet loss: recevied only {} packets of 100 "
-                           .format(path_1_counter + path_2_counter))
+        raise RuntimeError("Packet loss: recevied only {} packets of 100 ".
+                           format(path_1_counter + path_2_counter))
 
     if path_1_counter == 0:
         raise RuntimeError("Path 1 error!")
@@ -127,5 +137,6 @@ def main():
 
     sys.exit(0)
 
+
 if __name__ == "__main__":
     main()