Add MAC address check in ethernet-input node if interface in L3 mode

Interface can be in promiscuous mode if more than one of its sub-
interface is in L2 mode. In promiscuous mode, L3 interface need to
verify DMAC of packet to match that of the interface and drop if not.
This check was done on sub-interface only and now also added to main
interface path.

Fix incorrect MAC addresses in the flow-per-pkt plugin test, which
caused it to fail.

Fix MAC address usage in BFD tests.

Change-Id: I12a17ec05c7ab298ad10d400c90d082c97eca521
Signed-off-by: John Lo <loj@cisco.com>
Signed-off-by: Klement Sekera <ksekera@cisco.com>

3 files changed, 28 insertions, 8 deletions

diff --git a/src/vnet/ethernet/node.c b/src/vnet/ethernet/node.c
index 6d57da31708..b699e381f91 100755
--- a/src/vnet/ethernet/node.c
+++ b/src/vnet/ethernet/node.c
@@ -294,6 +294,7 @@ ethernet_input_inline (vlib_main_t * vm,
   u32 cpu_index = os_get_cpu_number ();
   u32 cached_sw_if_index = ~0;
   u32 cached_is_l2 = 0;		/* shut up gcc */
+  vnet_hw_interface_t *hi = NULL;	/* used for main interface only */
 
   if (variant != ETHERNET_INPUT_VARIANT_ETHERNET)
     error_node = vlib_node_get_runtime (vm, ethernet_input_node.index);
@@ -386,11 +387,12 @@ ethernet_input_inline (vlib_main_t * vm,
 	      if (PREDICT_FALSE (sw_if_index0 != sw_if_index1))
 		goto slowpath;
 
+	      /* Now sw_if_index0 == sw_if_index1  */
 	      if (PREDICT_FALSE (cached_sw_if_index != sw_if_index0))
 		{
 		  cached_sw_if_index = sw_if_index0;
-		  hi0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
-		  intf0 = vec_elt_at_index (em->main_intfs, hi0->hw_if_index);
+		  hi = vnet_get_sup_hw_interface (vnm, sw_if_index0);
+		  intf0 = vec_elt_at_index (em->main_intfs, hi->hw_if_index);
 		  subint0 = &intf0->untagged_subint;
 		  cached_is_l2 = is_l20 = subint0->flags & SUBINT_CONFIG_L2;
 		}
@@ -409,6 +411,12 @@ ethernet_input_inline (vlib_main_t * vm,
 		}
 	      else
 		{
+		  if (!ethernet_address_cast (e0->dst_address) &&
+		      !eth_mac_equal ((u8 *) e0, hi->hw_address))
+		    error0 = ETHERNET_ERROR_L3_MAC_MISMATCH;
+		  if (!ethernet_address_cast (e1->dst_address) &&
+		      !eth_mac_equal ((u8 *) e1, hi->hw_address))
+		    error1 = ETHERNET_ERROR_L3_MAC_MISMATCH;
 		  determine_next_node (em, variant, 0, type0, b0,
 				       &error0, &next0);
 		  vlib_buffer_advance (b0, sizeof (ethernet_header_t));
@@ -540,10 +548,10 @@ ethernet_input_inline (vlib_main_t * vm,
 	  determine_next_node (em, variant, is_l21, type1, b1, &error1,
 			       &next1);
 
+	ship_it01:
 	  b0->error = error_node->errors[error0];
 	  b1->error = error_node->errors[error1];
 
-	ship_it01:
 	  // verify speculative enqueue
 	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index, to_next,
 					   n_left_to_next, bi0, bi1, next0,
@@ -603,8 +611,8 @@ ethernet_input_inline (vlib_main_t * vm,
 	      if (PREDICT_FALSE (cached_sw_if_index != sw_if_index0))
 		{
 		  cached_sw_if_index = sw_if_index0;
-		  hi0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
-		  intf0 = vec_elt_at_index (em->main_intfs, hi0->hw_if_index);
+		  hi = vnet_get_sup_hw_interface (vnm, sw_if_index0);
+		  intf0 = vec_elt_at_index (em->main_intfs, hi->hw_if_index);
 		  subint0 = &intf0->untagged_subint;
 		  cached_is_l2 = is_l20 = subint0->flags & SUBINT_CONFIG_L2;
 		}
@@ -619,6 +627,9 @@ ethernet_input_inline (vlib_main_t * vm,
 		}
 	      else
 		{
+		  if (!ethernet_address_cast (e0->dst_address) &&
+		      !eth_mac_equal ((u8 *) e0, hi->hw_address))
+		    error0 = ETHERNET_ERROR_L3_MAC_MISMATCH;
 		  determine_next_node (em, variant, 0, type0, b0,
 				       &error0, &next0);
 		  vlib_buffer_advance (b0, sizeof (ethernet_header_t));
@@ -705,10 +716,10 @@ ethernet_input_inline (vlib_main_t * vm,
 	  determine_next_node (em, variant, is_l20, type0, b0, &error0,
 			       &next0);
 
+	ship_it0:
 	  b0->error = error_node->errors[error0];
 
 	  // verify speculative enqueue
-	ship_it0:
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next,
 					   bi0, next0);
diff --git a/test/test_bfd.py b/test/test_bfd.py
index 5460a2b5589..4e3f688b462 100644
--- a/test/test_bfd.py
+++ b/test/test_bfd.py
@@ -1090,6 +1090,9 @@ class BFD4TestCase(VppTestCase):
                     self.assertNotEqual(p[IP].src, self.loopback0.local_ip4,
                                         "BFD ECHO src IP equal to loopback IP")
                     self.logger.debug(ppp("Looping back packet:", p))
+                    self.assert_equal(p[Ether].dst, self.pg0.remote_mac,
+                                      "ECHO packet destination MAC address")
+                    p[Ether].dst = self.pg0.local_mac
                     self.pg0.add_stream(p)
                     self.pg_start()
                 elif p.haslayer(BFD):
@@ -1159,6 +1162,7 @@ class BFD4TestCase(VppTestCase):
             self.logger.debug(ppp("Got packet:", p))
             if p[UDP].dport == BFD.udp_dport_echo:
                 self.logger.debug(ppp("Looping back packet:", p))
+                p[Ether].dst = self.pg0.local_mac
                 self.pg0.add_stream(p)
                 self.pg_start()
                 break
@@ -1190,6 +1194,7 @@ class BFD4TestCase(VppTestCase):
             self.logger.debug(ppp("Got packet:", p))
             if p[UDP].dport == BFD.udp_dport_echo:
                 self.logger.debug(ppp("Looping back packet:", p))
+                p[Ether].dst = self.pg0.local_mac
                 self.pg0.add_stream(p)
                 self.pg_start()
                 break
@@ -1230,6 +1235,7 @@ class BFD4TestCase(VppTestCase):
                 else:
                     self.logger.debug(ppp("Got followup echo packet:", p))
                 self.logger.debug(ppp("Looping back first echo packet:", p))
+                echo_packet[Ether].dst = self.pg0.local_mac
                 self.pg0.add_stream(echo_packet)
                 self.pg_start()
             elif p.haslayer(BFD):
@@ -1278,6 +1284,7 @@ class BFD4TestCase(VppTestCase):
                     timeout_at = time.time() + self.vpp_session.detect_mult * \
                         self.test_session.required_min_echo_rx / USEC_IN_SEC
                 p[BFD_vpp_echo].checksum = getrandbits(64)
+                p[Ether].dst = self.pg0.local_mac
                 self.logger.debug(ppp("Looping back modified echo packet:", p))
                 self.pg0.add_stream(p)
                 self.pg_start()
@@ -1523,7 +1530,6 @@ class BFD6TestCase(VppTestCase):
         self.assert_equal(udp_sport_tx, udp_sport_rx, "UDP source port (== "
                           "ECHO packet identifier for test purposes)")
 
-    @unittest.skipUnless(running_extended_tests(), "part of extended tests")
     def test_echo(self):
         """ echo function used """
         bfd_session_up(self)
@@ -1554,6 +1560,9 @@ class BFD6TestCase(VppTestCase):
                     self.assertNotEqual(p[IPv6].src, self.loopback0.local_ip6,
                                         "BFD ECHO src IP equal to loopback IP")
                     self.logger.debug(ppp("Looping back packet:", p))
+                    self.assert_equal(p[Ether].dst, self.pg0.remote_mac,
+                                      "ECHO packet destination MAC address")
+                    p[Ether].dst = self.pg0.local_mac
                     self.pg0.add_stream(p)
                     self.pg_start()
                 elif p.haslayer(BFD):
diff --git a/test/test_flowperpkt.py b/test/test_flowperpkt.py
index f16bfb7eb5b..b13d0c63a1b 100644
--- a/test/test_flowperpkt.py
+++ b/test/test_flowperpkt.py
@@ -43,7 +43,7 @@ class TestFlowperpkt(VppTestCase):
         for size in packet_sizes:
             info = self.create_packet_info(src_if, dst_if)
             payload = self.info_to_payload(info)
-            p = (Ether(src=src_if.local_mac, dst=dst_if.remote_mac) /
+            p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
                  IP(src=src_if.remote_ip4, dst=dst_if.remote_ip4) /
                  UDP(sport=1234, dport=4321) /
                  Raw(payload))