ip: allow addrs from the same prefix on intf

Type: feature

Adding a prefix to an interface was not permitted if it overlapped
with another prefix on an interface which used the same FIB.

Loosen the restriction. Allow 2 or more addresses from the same
prefix on a single interface. Reference count the prefix to figure
out when a glean/connected route for the prefix needs to be added
or removed.

Added unit tests to check that the route is only removed when all
addresses in the prefix are removed from the interface.

Change-Id: I1a962ecb5e1ee65fc6d41f98a4cc097a51a55321
Signed-off-by: Matthew Smith <mgsmith@netgate.com>

1 files changed, 77 insertions, 2 deletions

diff --git a/test/test_ip6.py b/test/test_ip6.py
index f8295513516..f2c4c00424e 100644
--- a/test/test_ip6.py
+++ b/test/test_ip6.py
@@ -20,10 +20,11 @@ from six import moves
 
 from framework import VppTestCase, VppTestRunner
 from util import ppp, ip6_normalize, mk_ll_addr
-from vpp_ip import DpoProto
+from vpp_ip import DpoProto, VppIpAddress
 from vpp_ip_route import VppIpRoute, VppRoutePath, find_route, VppIpMRoute, \
     VppMRoutePath, MRouteItfFlags, MRouteEntryFlags, VppMplsIpBind, \
-    VppMplsRoute, VppMplsTable, VppIpTable, FibPathType
+    VppMplsRoute, VppMplsTable, VppIpTable, FibPathType, \
+    VppIpInterfaceAddress
 from vpp_neighbor import find_nbr, VppNeighbor
 from vpp_pg_interface import is_ipv6_misc
 from vpp_sub_interface import VppSubInterface, VppDot1QSubint
@@ -935,6 +936,80 @@ class TestIPv6(TestIPv6ND):
         self.pg0.ip6_ra_config(no=1, suppress=1, send_unicast=0)
 
 
+class TestIPv6IfAddrRoute(VppTestCase):
+    """ IPv6 Interface Addr Route Test Case """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPv6IfAddrRoute, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPv6IfAddrRoute, cls).tearDownClass()
+
+    def setUp(self):
+        super(TestIPv6IfAddrRoute, self).setUp()
+
+        # create 1 pg interface
+        self.create_pg_interfaces(range(1))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip6()
+            i.resolve_ndp()
+
+    def tearDown(self):
+        super(TestIPv6IfAddrRoute, self).tearDown()
+        for i in self.pg_interfaces:
+            i.unconfig_ip6()
+            i.admin_down()
+
+    def test_ipv6_ifaddrs_same_prefix(self):
+        """ IPv6 Interface Addresses Same Prefix test
+
+        Test scenario:
+
+            - Verify no route in FIB for prefix 2001:10::/64
+            - Configure IPv4 address 2001:10::10/64  on an interface
+            - Verify route in FIB for prefix 2001:10::/64
+            - Configure IPv4 address 2001:10::20/64 on an interface
+            - Delete 2001:10::10/64 from interface
+            - Verify route in FIB for prefix 2001:10::/64
+            - Delete 2001:10::20/64 from interface
+            - Verify no route in FIB for prefix 2001:10::/64
+        """
+
+        addr1 = "2001:10::10"
+        addr2 = "2001:10::20"
+
+        if_addr1 = VppIpInterfaceAddress(self, self.pg0,
+                                         VppIpAddress(addr1), 64)
+        if_addr2 = VppIpInterfaceAddress(self, self.pg0,
+                                         VppIpAddress(addr2), 64)
+        self.assertFalse(if_addr1.query_vpp_config())  # 2001:10::/64
+        self.assertFalse(find_route(self, addr1, 128))
+        self.assertFalse(find_route(self, addr2, 128))
+
+        # configure first address, verify route present
+        if_addr1.add_vpp_config()
+        self.assertTrue(if_addr1.query_vpp_config())  # 2001:10::/64
+        self.assertTrue(find_route(self, addr1, 128))
+        self.assertFalse(find_route(self, addr2, 128))
+
+        # configure second address, delete first, verify route not removed
+        if_addr2.add_vpp_config()
+        if_addr1.remove_vpp_config()
+        self.assertTrue(if_addr1.query_vpp_config())  # 2001:10::/64
+        self.assertFalse(find_route(self, addr1, 128))
+        self.assertTrue(find_route(self, addr2, 128))
+
+        # delete second address, verify route removed
+        if_addr2.remove_vpp_config()
+        self.assertFalse(if_addr1.query_vpp_config())  # 2001:10::/64
+        self.assertFalse(find_route(self, addr1, 128))
+        self.assertFalse(find_route(self, addr2, 128))
+
+
 class TestICMPv6Echo(VppTestCase):
     """ ICMPv6 Echo Test Case """