Ignore unexpected ICMPv6 Neighbor Discovery - Neighbor Solicitation packets

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

diff --git a/resources/traffic_scripts/policer.py b/resources/traffic_scripts/policer.py
index ee9fa29..62c397d 100755 (executable)
--- a/resources/traffic_scripts/policer.py
+++ b/resources/traffic_scripts/policer.py
@@ -21,7 +21,10 @@ import logging
 # pylint: disable=no-name-in-module
 # pylint: disable=import-error
 logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
-from scapy.all import Ether, IP, IPv6, TCP
+
+from scapy.all import Ether
+from scapy.layers.inet import IP, TCP
+from scapy.layers.inet6 import IPv6, ICMPv6ND_NS
 from ipaddress import ip_address
 
 from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
@@ -38,17 +41,17 @@ def check_ipv4(pkt_recv, dscp):
     :raises RuntimeError: If received packet is invalid.
     """
     if not pkt_recv.haslayer(IP):
-        raise RuntimeError(
-            'Not an IPv4 packet received: {0}'.format(pkt_recv.__repr__()))
+        raise RuntimeError('Not an IPv4 packet received: {0}'.
+                           format(pkt_recv.__repr__()))
 
-    rx_dscp = pkt_recv['IP'].tos >> 2
+    rx_dscp = pkt_recv[IP].tos >> 2
     if rx_dscp != dscp:
-        raise RuntimeError(
-            'Invalid DSCP {0} should be {1}'.format(rx_dscp, dscp))
+        raise RuntimeError('Invalid DSCP {0} should be {1}'.
+                           format(rx_dscp, dscp))
 
     if not pkt_recv.haslayer(TCP):
-        raise RuntimeError(
-            'Not a TCP packet received: {0}'.format(pkt_recv.__repr__()))
+        raise RuntimeError('Not a TCP packet received: {0}'.
+                           format(pkt_recv.__repr__()))
 
 
 def check_ipv6(pkt_recv, dscp):
@@ -61,17 +64,17 @@ def check_ipv6(pkt_recv, dscp):
     :raises RuntimeError: If received packet is invalid.
     """
     if not pkt_recv.haslayer(IPv6):
-        raise RuntimeError(
-            'Not an IPv6 packet received: {0}'.format(pkt_recv.__repr__()))
+        raise RuntimeError('Not an IPv6 packet received: {0}'.
+                           format(pkt_recv.__repr__()))
 
-    rx_dscp = pkt_recv['IPv6'].tc >> 2
+    rx_dscp = pkt_recv[IPv6].tc >> 2
     if rx_dscp != dscp:
-        raise RuntimeError(
-            'Invalid DSCP {0} should be {1}'.format(rx_dscp, dscp))
+        raise RuntimeError('Invalid DSCP {0} should be {1}'.
+                           format(rx_dscp, dscp))
 
     if not pkt_recv.haslayer(TCP):
-        raise RuntimeError(
-            'Not a TCP packet received: {0}'.format(pkt_recv.__repr__()))
+        raise RuntimeError('Not a TCP packet received: {0}'.
+                           format(pkt_recv.__repr__()))
 
 
 # pylint: disable=too-many-locals
@@ -97,19 +100,29 @@ def main():
     sent_packets = []
 
     if is_ipv4:
-        ip_pkt = IP(src=src_ip, dst=dst_ip) / \
-                 TCP()
+        ip_pkt = (IP(src=src_ip, dst=dst_ip) /
+                  TCP())
     else:
-        ip_pkt = IPv6(src=src_ip, dst=dst_ip) / \
-                 TCP()
+        ip_pkt = (IPv6(src=src_ip, dst=dst_ip) /
+                  TCP())
 
-    pkt_send = Ether(src=src_mac, dst=dst_mac) / \
-               ip_pkt
+    pkt_send = (Ether(src=src_mac, dst=dst_mac) /
+                ip_pkt)
 
     sent_packets.append(pkt_send)
     txq.send(pkt_send)
 
-    pkt_recv = rxq.recv(2, sent_packets)
+    while True:
+        pkt_recv = rxq.recv(2, sent_packets)
+        if pkt_recv is None:
+            raise RuntimeError('ICMPv6 echo reply Rx timeout')
+
+        if pkt_recv.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 pkt_recv is None:
         raise RuntimeError('Rx timeout')
@@ -121,5 +134,6 @@ def main():
 
     sys.exit(0)
 
+
 if __name__ == "__main__":
     main()