fib: During the mfib lookup set the unicast FIB index in the packet so that a uRPF check on a for-us packet is done in the correct VRF

Type: fix

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Iafa6efea0d96962aa9136dccefc148a961f74476

2 files changed, 67 insertions, 28 deletions

diff --git a/src/vnet/mfib/mfib_forward.c b/src/vnet/mfib/mfib_forward.c
index e02c1d87f56..a7b7a6bed4b 100644
--- a/src/vnet/mfib/mfib_forward.c
+++ b/src/vnet/mfib/mfib_forward.c
@@ -150,32 +150,34 @@ mfib_forward_lookup (vlib_main_t * vm,
             {
                 ip4_header_t * ip0;
 
-                fib_index0 = vec_elt (ip4_main.mfib_index_by_sw_if_index,
-                                      vnet_buffer(p0)->sw_if_index[VLIB_RX]);
-                ip0 = vlib_buffer_get_current (p0);
-                mfei0 = ip4_mfib_table_lookup(ip4_mfib_get(fib_index0),
-                                              &ip0->src_address,
-                                              &ip0->dst_address,
-                                              64);
-            }
-            else
-            {
-                ip6_header_t * ip0;
-
-                fib_index0 = vec_elt (ip6_main.mfib_index_by_sw_if_index,
-                                      vnet_buffer(p0)->sw_if_index[VLIB_RX]);
-                ip0 = vlib_buffer_get_current (p0);
-                mfei0 = ip6_mfib_table_fwd_lookup(ip6_mfib_get(fib_index0),
-                                                  &ip0->src_address,
-                                                  &ip0->dst_address);
-            }
-
-            vnet_buffer (p0)->ip.adj_index[VLIB_TX] = mfei0;
-        }
-
-        vlib_put_next_frame(vm, node,
-                            MFIB_FORWARD_LOOKUP_NEXT_RPF,
-                            n_left_to_next);
+		ip_lookup_set_buffer_fib_index (
+		  ip4_main.fib_index_by_sw_if_index, p0);
+		fib_index0 = vec_elt (ip4_main.mfib_index_by_sw_if_index,
+				      vnet_buffer (p0)->sw_if_index[VLIB_RX]);
+		ip0 = vlib_buffer_get_current (p0);
+		mfei0 = ip4_mfib_table_lookup (ip4_mfib_get (fib_index0),
+					       &ip0->src_address,
+					       &ip0->dst_address, 64);
+	    }
+	    else
+	      {
+		ip6_header_t *ip0;
+
+		ip_lookup_set_buffer_fib_index (
+		  ip6_main.fib_index_by_sw_if_index, p0);
+		fib_index0 = vec_elt (ip6_main.mfib_index_by_sw_if_index,
+				      vnet_buffer (p0)->sw_if_index[VLIB_RX]);
+		ip0 = vlib_buffer_get_current (p0);
+		mfei0 = ip6_mfib_table_fwd_lookup (ip6_mfib_get (fib_index0),
+						   &ip0->src_address,
+						   &ip0->dst_address);
+	      }
+
+	    vnet_buffer (p0)->ip.adj_index[VLIB_TX] = mfei0;
+	}
+
+	vlib_put_next_frame (vm, node, MFIB_FORWARD_LOOKUP_NEXT_RPF,
+			     n_left_to_next);
     }
 
     if (node->flags & VLIB_NODE_FLAG_TRACE)
diff --git a/test/test_ip_mcast.py b/test/test_ip_mcast.py
index 2799218125c..20079aa27d5 100644
--- a/test/test_ip_mcast.py
+++ b/test/test_ip_mcast.py
@@ -6,13 +6,13 @@ from framework import tag_fixme_vpp_workers
 from framework import VppTestCase, VppTestRunner
 from vpp_ip import DpoProto
 from vpp_ip_route import VppIpMRoute, VppMRoutePath, VppMFibSignal, \
-    VppIpTable, FibPathProto
+    VppIpTable, FibPathProto, FibPathType
 from vpp_gre_interface import VppGreInterface
 from vpp_papi import VppEnum
 
 from scapy.packet import Raw
 from scapy.layers.l2 import Ether, GRE
-from scapy.layers.inet import IP, UDP, getmacbyip
+from scapy.layers.inet import IP, UDP, getmacbyip, ICMP
 from scapy.layers.inet6 import IPv6, getmacbyip6
 
 #
@@ -846,6 +846,43 @@ class TestIPMcast(VppTestCase):
         self.verify_capture_ip4(self.pg1, tx)
         self.verify_capture_ip4(self.pg2, tx)
 
+        #
+        # An (S,G). for for-us
+        #
+        route_0_0_0_0_224_0_0_5 = VppIpMRoute(
+            self,
+            "0.0.0.0",
+            "224.0.0.5", 32,
+            MRouteEntryFlags.MFIB_API_ENTRY_FLAG_NONE,
+            [VppMRoutePath(self.pg8.sw_if_index,
+                           MRouteItfFlags.MFIB_API_ITF_FLAG_ACCEPT),
+             VppMRoutePath(0xffffffff,
+                           MRouteItfFlags.MFIB_API_ITF_FLAG_FORWARD,
+                           type=FibPathType.FIB_PATH_TYPE_LOCAL)],
+            table_id=10)
+        route_0_0_0_0_224_0_0_5.add_vpp_config()
+
+        #
+        # a stream that matches the route for (0.0.0.0, 224.0.0.5)
+        #  small packets
+        #
+        self.vapi.cli("clear trace")
+        self.pg8.resolve_arp()
+
+        #
+        # send a ping to mcast address from peer on pg8
+        #  expect a response
+        #
+        icmp_id = 0xb
+        icmp_seq = 5
+        icmp_load = b'\x0a' * 18
+        tx = (Ether(dst=getmacbyip("224.0.0.5"), src=self.pg8.remote_mac) /
+              IP(src=self.pg8.remote_ip4, dst="224.0.0.5") /
+              ICMP(id=icmp_id, seq=icmp_seq) /
+              Raw(load=icmp_load)) * 2
+
+        self.send_and_expect(self.pg8, tx, self.pg8)
+
     def test_ip_mcast_gre(self):
         """ IP Multicast Replication over GRE"""