Sub-net broadcast addresses for IPv4

Change-Id: Ib2189d01e8bc61de57404159690fb70f89c47277
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 124 insertions, 1 deletions

diff --git a/test/test_ip4.py b/test/test_ip4.py
index 79af5492e18..ed364b62cbb 100644
--- a/test/test_ip4.py
+++ b/test/test_ip4.py
@@ -9,7 +9,7 @@ from vpp_ip_route import VppIpRoute, VppRoutePath, VppIpMRoute, \
     VppMRoutePath, MRouteItfFlags, MRouteEntryFlags
 
 from scapy.packet import Raw
-from scapy.layers.l2 import Ether, Dot1Q
+from scapy.layers.l2 import Ether, Dot1Q, ARP
 from scapy.layers.inet import IP, UDP, ICMP, icmptypes, icmpcodes
 from util import ppp
 
@@ -643,5 +643,128 @@ class TestIPDisabled(VppTestCase):
         self.send_and_assert_no_replies(self.pg1, pm, "IP disabled")
 
 
+class TestIPSubNets(VppTestCase):
+    """ IPv4 Subnets """
+
+    def setUp(self):
+        super(TestIPSubNets, self).setUp()
+
+        # create a 2 pg interfaces
+        self.create_pg_interfaces(range(2))
+
+        # pg0 we will use to experiemnt
+        self.pg0.admin_up()
+
+        # pg1 is setup normally
+        self.pg1.admin_up()
+        self.pg1.config_ip4()
+        self.pg1.resolve_arp()
+
+    def tearDown(self):
+        super(TestIPSubNets, self).tearDown()
+        for i in self.pg_interfaces:
+            i.admin_down()
+
+    def send_and_assert_no_replies(self, intf, pkts, remark):
+        intf.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        for i in self.pg_interfaces:
+            i.get_capture(0)
+            i.assert_nothing_captured(remark=remark)
+
+    def test_ip_sub_nets(self):
+        """ IP Sub Nets """
+
+        #
+        # Configure a covering route to forward so we know
+        # when we are dropping
+        #
+        cover_route = VppIpRoute(self, "10.0.0.0", 8,
+                                 [VppRoutePath(self.pg1.remote_ip4,
+                                               self.pg1.sw_if_index)])
+        cover_route.add_vpp_config()
+
+        p = (Ether(src=self.pg1.remote_mac,
+                   dst=self.pg1.local_mac) /
+             IP(dst="10.10.10.10", src=self.pg0.local_ip4) /
+             UDP(sport=1234, dport=1234) /
+             Raw('\xa5' * 100))
+
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = self.pg1.get_capture(1)
+
+        #
+        # Configure some non-/24 subnets on an IP interface
+        #
+        ip_addr_n = socket.inet_pton(socket.AF_INET, "10.10.10.10")
+
+        self.vapi.sw_interface_add_del_address(self.pg0.sw_if_index,
+                                               ip_addr_n,
+                                               16)
+
+        pn = (Ether(src=self.pg1.remote_mac,
+                    dst=self.pg1.local_mac) /
+              IP(dst="10.10.0.0", src=self.pg0.local_ip4) /
+              UDP(sport=1234, dport=1234) /
+              Raw('\xa5' * 100))
+        pb = (Ether(src=self.pg1.remote_mac,
+                    dst=self.pg1.local_mac) /
+              IP(dst="10.10.255.255", src=self.pg0.local_ip4) /
+              UDP(sport=1234, dport=1234) /
+              Raw('\xa5' * 100))
+
+        self.send_and_assert_no_replies(self.pg1, pn, "IP Network address")
+        self.send_and_assert_no_replies(self.pg1, pb, "IP Broadcast address")
+
+        # remove the sub-net and we are forwarding via the cover again
+        self.vapi.sw_interface_add_del_address(self.pg0.sw_if_index,
+                                               ip_addr_n,
+                                               16,
+                                               is_add=0)
+        self.pg1.add_stream(pn)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = self.pg1.get_capture(1)
+        self.pg1.add_stream(pb)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = self.pg1.get_capture(1)
+
+        #
+        # A /31 is a special case where the 'other-side' is an attached host
+        # packets to that peer generate ARP requests
+        #
+        ip_addr_n = socket.inet_pton(socket.AF_INET, "10.10.10.10")
+
+        self.vapi.sw_interface_add_del_address(self.pg0.sw_if_index,
+                                               ip_addr_n,
+                                               31)
+
+        pn = (Ether(src=self.pg1.remote_mac,
+                    dst=self.pg1.local_mac) /
+              IP(dst="10.10.10.11", src=self.pg0.local_ip4) /
+              UDP(sport=1234, dport=1234) /
+              Raw('\xa5' * 100))
+
+        self.pg1.add_stream(pn)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = self.pg0.get_capture(1)
+        rx[ARP]
+
+        # remove the sub-net and we are forwarding via the cover again
+        self.vapi.sw_interface_add_del_address(self.pg0.sw_if_index,
+                                               ip_addr_n,
+                                               31,
+                                               is_add=0)
+        self.pg1.add_stream(pn)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = self.pg1.get_capture(1)
+
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)