ip: The check for 'same packet' must include the FIB index

Type: fix

otherwise if two packets arrive with the same source address but from different VRFs, then they are treated as the same and they use the same LB and thus share the same fate. but the lookup, when done, results in two different LBs, and hence the fate can be different.

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Id6e16f7c577a561d9ddd7066339fa4385361d07f

src/vnet/ip/ip4_forward.c

@@ -1517,7 +1517,9 @@ ip4_local_set_next_and_error (vlib_node_runtime_t * error_node,
 
 typedef struct
 {
+  /* The src and fib-index together determine if packet n is the same as n-1 */
   ip4_address_t src;
+  u32 fib_index;
   u32 lbi;
   u8 error;
   u8 first;
@@ -1551,7 +1553,8 @@ ip4_local_check_src (vlib_buffer_t *b, ip4_header_t *ip0,
    * vnet_buffer()->ip.adj_index[VLIB_TX] will be set to the index of the
    *  adjacency for the source address (the remote sender's address)
    */
-  if (PREDICT_TRUE (last_check->src.as_u32 != ip0->src_address.as_u32) ||
+  if (PREDICT_TRUE ((last_check->src.as_u32 != ip0->src_address.as_u32)) ||
+      (last_check->fib_index != vnet_buffer (b)->ip.fib_index) ||
       last_check->first)
     {
       lbi0 = ip4_fib_forwarding_lookup (vnet_buffer (b)->ip.fib_index,
@@ -1587,6 +1590,7 @@ ip4_local_check_src (vlib_buffer_t *b, ip4_header_t *ip0,
       last_check->lbi = lbi0;
       last_check->error = *error0;
       last_check->first = 0;
+      last_check->fib_index = vnet_buffer (b)->ip.fib_index;
     }
   else
     {
@@ -1621,6 +1625,9 @@ ip4_local_check_src_x2 (vlib_buffer_t **b, ip4_header_t **ip,
     vnet_buffer (b[1])->sw_if_index[VLIB_TX] :
     vnet_buffer (b[1])->ip.fib_index;
 
+  not_last_hit |= vnet_buffer (b[0])->ip.fib_index ^ last_check->fib_index;
+  not_last_hit |= vnet_buffer (b[1])->ip.fib_index ^ last_check->fib_index;
+
   if (is_receive_dpo)
     {
       const receive_dpo_t *rd0, *rd1;
@@ -1683,6 +1690,7 @@ ip4_local_check_src_x2 (vlib_buffer_t **b, ip4_header_t **ip,
       last_check->lbi = lbi[1];
       last_check->error = error[1];
       last_check->first = 0;
+      last_check->fib_index = vnet_buffer (b[1])->ip.fib_index;
     }
   else
     {
@@ -1752,10 +1760,11 @@ ip4_local_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
      * member to make sure the .lbi is initialised for the first
      * packet.
      */
-    .src = {.as_u32 = 0},
+    .src = { .as_u32 = 0 },
     .lbi = ~0,
     .error = IP4_ERROR_UNKNOWN_PROTOCOL,
     .first = 1,
+    .fib_index = 0,
   };
 
   from = vlib_frame_vector_args (frame);

test/test_ip4.py

@@ -7,6 +7,7 @@ import unittest
 import scapy.compat
 from scapy.contrib.mpls import MPLS
 from scapy.layers.inet import IP, UDP, TCP, ICMP, icmptypes, icmpcodes
+from scapy.layers.inet6 import IPv6
 from scapy.layers.l2 import Ether, Dot1Q, ARP
 from scapy.packet import Raw
 from six import moves
@@ -1460,6 +1461,20 @@ class IPPuntSetup(object):
 
         self.vapi.set_punt(is_add=1, punt=punt_udp)
 
+        af_ip6 = VppEnum.vl_api_address_family_t.ADDRESS_IP6
+        punt_udp = {
+            'type': pt_l4,
+            'punt': {
+                'l4': {
+                    'af': af_ip6,
+                    'protocol': udp_proto,
+                    'port': 1236,
+                }
+            }
+        }
+
+        self.vapi.set_punt(is_add=1, punt=punt_udp)
+
         self.pkt = (Ether(src=self.pg0.remote_mac,
                           dst=self.pg0.local_mac) /
                     IP(src=self.pg0.remote_ip4, dst=self.pg0.local_ip4) /
@@ -1569,6 +1584,172 @@ class TestIPPunt(IPPuntSetup, VppTestCase):
         self.send_and_expect(self.pg0, pkts, self.pg1)
         ip_punt_redirect.remove_vpp_config()
 
+    def test_ip_punt_vrf(self):
+        """ IP punt/local with VRFs """
+
+        # use a punt redirect to test if for-us  packets are accepted
+        pkts = self.pkt * 1025
+
+        vlans_pg0 = [VppDot1QSubint(self, self.pg0, v)
+                     for v in range(100, 104)]
+        vlans_pg1 = [VppDot1QSubint(self, self.pg1, v)
+                     for v in range(100, 104)]
+        tbl4 = [VppIpTable(self, v).add_vpp_config()
+                for v in range(100, 104)]
+        tbl6 = [VppIpTable(self, v, True).add_vpp_config()
+                for v in range(100, 104)]
+
+        for v in vlans_pg0 + vlans_pg1:
+            v.admin_up()
+            v.set_table_ip4(v.vlan)
+            v.set_table_ip6(v.vlan)
+            v.config_ip4()
+            v.config_ip6()
+            v.resolve_arp()
+            v.resolve_ndp()
+
+        [VppIpPuntRedirect
+         (self,
+          vlans_pg0[i].sw_if_index,
+          vlans_pg1[i].sw_if_index,
+          vlans_pg1[i].remote_ip4).add_vpp_config()
+         for i in range(4)]
+        [VppIpPuntRedirect
+         (self,
+          vlans_pg0[i].sw_if_index,
+          vlans_pg1[i].sw_if_index,
+          vlans_pg1[i].remote_ip6).add_vpp_config()
+         for i in range(4)]
+
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IP(src=i.remote_ip4,
+                    dst=i.local_ip4) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+
+        self.send_and_expect(self.pg0, pkts, self.pg1)
+
+        #
+        # IPv4
+        #
+
+        # we reject packets for source addresses in the wrong vlan/VRF
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IP(src="1.1.1.1",
+                    dst=i.local_ip4) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+        # single and dual loop
+        self.send_and_assert_no_replies(self.pg0, [pkts[0]])
+        self.send_and_assert_no_replies(self.pg0, pkts)
+
+        self.assert_error_counter_equal(
+            "/err/ip4-local/ip4 source lookup miss",
+            len(pkts) + 1)
+
+        # using the same source in different tables, should reject
+        # for the table that the source is not present in
+        # the first packet in the stream is drop
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IP(src=vlans_pg0[0].remote_ip4,
+                    dst=i.local_ip4) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+        # single loop accept and drop
+        # followed by both in the same frame/loop
+        self.send_and_expect(self.pg0, [pkts[0]], self.pg1)
+        self.send_and_assert_no_replies(self.pg0, [pkts[1]])
+        self.send_and_expect(self.pg0, pkts * 4, self.pg1, n_rx=4)
+
+        # using the same source in different tables, should reject
+        # for the table that the source is not present in
+        # the first packet in the stream is accept
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IP(src=vlans_pg0[3].remote_ip4,
+                    dst=i.local_ip4) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+
+        # single loop accept and drop
+        # followed by both in the same frame/loop
+        self.send_and_expect(self.pg0, [pkts[3]], self.pg1)
+        self.send_and_assert_no_replies(self.pg0, [pkts[1]])
+        self.send_and_expect(self.pg0, pkts * 4, self.pg1, n_rx=4)
+
+        #
+        # IPv6
+        #
+
+        # we reject packets for source addresses in the wrong vlan/VRF
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IPv6(src="1::1",
+                      dst=i.local_ip6) /
+                 UDP(sport=1236, dport=1236) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+        # single and dual loop
+        self.send_and_assert_no_replies(self.pg0, [pkts[0]])
+        self.send_and_assert_no_replies(self.pg0, pkts)
+
+        self.assert_error_counter_equal(
+            "/err/ip6-input/ip6 source lookup miss",
+            len(pkts) + 1)
+
+        # using the same source in different tables, should reject
+        # for the table that the source is not present in
+        # the first packet in the stream is drop
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IPv6(src=vlans_pg0[0].remote_ip6,
+                      dst=i.local_ip6) /
+                 UDP(sport=1236, dport=1236) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+        # single loop accept and drop
+        # followed by both in the same frame/loop
+        self.send_and_expect(self.pg0, [pkts[0]], self.pg1)
+        self.send_and_assert_no_replies(self.pg0, [pkts[1]])
+        self.send_and_expect(self.pg0, pkts * 4, self.pg1, n_rx=4)
+
+        # using the same source in different tables, should reject
+        # for the table that the source is not present in
+        # the first packet in the stream is accept
+        pkts = [(Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 Dot1Q(vlan=i.vlan) /
+                 IPv6(src=vlans_pg0[3].remote_ip6,
+                      dst=i.local_ip6) /
+                 UDP(sport=1236, dport=1236) /
+                 Raw(b'\xa5' * 100))
+                for i in vlans_pg0]
+
+        # single loop accept and drop
+        # followed by both in the same frame/loop
+        self.send_and_expect(self.pg0, [pkts[3]], self.pg1)
+        self.send_and_assert_no_replies(self.pg0, [pkts[1]])
+        self.send_and_expect(self.pg0, pkts * 4, self.pg1, n_rx=4)
+
+        for v in vlans_pg0 + vlans_pg1:
+            v.unconfig_ip4()
+            v.unconfig_ip6()
+            v.set_table_ip4(0)
+            v.set_table_ip6(0)
+
     def test_ip_punt_dump(self):
         """ IP4 punt redirect dump"""
 

test/vpp_ip.py

@@ -168,6 +168,7 @@ class VppIpPuntRedirect(VppObject):
     def add_vpp_config(self):
         self._test.vapi.ip_punt_redirect(punt=self.encode(), is_add=True)
         self._test.registry.register(self, self._test.logger)
+        return self
 
     def remove_vpp_config(self):
         self._test.vapi.ip_punt_redirect(punt=self.encode(), is_add=False)