Add IRB test

- JIRA: CSIT-255
- create loopback interfaces
- move pg-interface specific arp and neighbor discovery from vpp_interface to vpp_pg_interface
- base configuration of IRB tests
- IP test scenario

Change-Id: I9945a188163652a4e22325877aef008c4d029557
Signed-off-by: Matej Klotton <mklotton@cisco.com>

test/vpp_pg_interface.py

@@ -1,9 +1,12 @@
 import os
 import time
-from logging import error
+from logging import error, info
 from scapy.utils import wrpcap, rdpcap
 from vpp_interface import VppInterface
 
+from scapy.layers.l2 import Ether, ARP
+from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_NA, ICMPv6NDOptSrcLLAddr, ICMPv6NDOptDstLLAddr
+
 
 class VppPGInterface(VppInterface):
     """
@@ -130,3 +133,89 @@ class VppPGInterface(VppInterface):
                   " packets arrived" % self.out_path)
             return []
         return output
+
+    def create_arp_req(self):
+        """Create ARP request applicable for this interface"""
+        return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
+                ARP(op=ARP.who_has, pdst=self.local_ip4,
+                    psrc=self.remote_ip4, hwsrc=self.remote_mac))
+
+    def create_ndp_req(self):
+        """Create NDP - NS applicable for this interface"""
+        return (Ether(dst="ff:ff:ff:ff:ff:ff", src=self.remote_mac) /
+              IPv6(src=self.remote_ip6, dst=self.local_ip6) /
+              ICMPv6ND_NS(tgt=self.local_ip6) /
+              ICMPv6NDOptSrcLLAddr(lladdr=self.remote_mac))
+
+    def resolve_arp(self, pg_interface=None):
+        """Resolve ARP using provided packet-generator interface
+
+        :param pg_interface: interface used to resolve, if None then this
+            interface is used
+
+        """
+        if pg_interface is None:
+            pg_interface = self
+        info("Sending ARP request for %s on port %s" %
+             (self.local_ip4, pg_interface.name))
+        arp_req = self.create_arp_req()
+        pg_interface.add_stream(arp_req)
+        pg_interface.enable_capture()
+        self.test.pg_start()
+        info(self.test.vapi.cli("show trace"))
+        arp_reply = pg_interface.get_capture()
+        if arp_reply is None or len(arp_reply) == 0:
+            info("No ARP received on port %s" % pg_interface.name)
+            return
+        arp_reply = arp_reply[0]
+        # Make Dot1AD packet content recognizable to scapy
+        if arp_reply.type == 0x88a8:
+            arp_reply.type = 0x8100
+            arp_reply = Ether(str(arp_reply))
+        try:
+            if arp_reply[ARP].op == ARP.is_at:
+                info("VPP %s MAC address is %s " %
+                     (self.name, arp_reply[ARP].hwsrc))
+                self._local_mac = arp_reply[ARP].hwsrc
+            else:
+                info("No ARP received on port %s" % pg_interface.name)
+        except:
+            error("Unexpected response to ARP request:")
+            error(arp_reply.show())
+            raise
+
+    def resolve_ndp(self, pg_interface=None):
+        """Resolve NDP using provided packet-generator interface
+
+        :param pg_interface: interface used to resolve, if None then this
+            interface is used
+
+        """
+        if pg_interface is None:
+            pg_interface = self
+        info("Sending NDP request for %s on port %s" %
+             (self.local_ip6, pg_interface.name))
+        ndp_req = self.create_ndp_req()
+        pg_interface.add_stream(ndp_req)
+        pg_interface.enable_capture()
+        self.test.pg_start()
+        info(self.test.vapi.cli("show trace"))
+        ndp_reply = pg_interface.get_capture()
+        if ndp_reply is None or len(ndp_reply) == 0:
+            info("No NDP received on port %s" % pg_interface.name)
+            return
+        ndp_reply = ndp_reply[0]
+        # Make Dot1AD packet content recognizable to scapy
+        if ndp_reply.type == 0x88a8:
+            ndp_reply.type = 0x8100
+            ndp_reply = Ether(str(ndp_reply))
+        try:
+            ndp_na = ndp_reply[ICMPv6ND_NA]
+            opt = ndp_na[ICMPv6NDOptDstLLAddr]
+            info("VPP %s MAC address is %s " %
+                 (self.name, opt.lladdr))
+            self._local_mac = opt.lladdr
+        except:
+            error("Unexpected response to NDP request:")
+            error(ndp_reply.show())
+            raise