map: honor pre-resolve param in map-t

With this commit, forward the translated packet directly to the
specified next-hop if pre-resolve param is enabled in MAP-T.

Type: fix

Change-Id: Ie26080c7820318c7982599577a4af6e4d01a0574
Signed-off-by: Alexander Chernavin <achernavin@netgate.com>
(cherry picked from commit f145c15631ba62e798395499f83a2f8a91ae83c7)
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

6 files changed, 153 insertions, 30 deletions

diff --git a/src/plugins/map/ip4_map.c b/src/plugins/map/ip4_map.c
index 64da602e838..f92438e9161 100644
--- a/src/plugins/map/ip4_map.c
+++ b/src/plugins/map/ip4_map.c
@@ -123,20 +123,6 @@ ip4_map_vtcfl (ip4_header_t * ip4, vlib_buffer_t * p)
   return (clib_host_to_net_u32 (vtcfl));
 }
 
-static_always_inline bool
-ip4_map_ip6_lookup_bypass (vlib_buffer_t * p0, ip4_header_t * ip)
-{
-#ifdef MAP_SKIP_IP6_LOOKUP
-  if (FIB_NODE_INDEX_INVALID != pre_resolved[FIB_PROTOCOL_IP6].fei)
-    {
-      vnet_buffer (p0)->ip.adj_index[VLIB_TX] =
-	pre_resolved[FIB_PROTOCOL_IP6].dpo.dpoi_index;
-      return (true);
-    }
-#endif
-  return (false);
-}
-
 /*
  * ip4_map_ttl
  */
diff --git a/src/plugins/map/ip4_map_t.c b/src/plugins/map/ip4_map_t.c
index 21d17d77910..127a97e85e9 100644
--- a/src/plugins/map/ip4_map_t.c
+++ b/src/plugins/map/ip4_map_t.c
@@ -29,6 +29,7 @@ typedef enum
 typedef enum
 {
   IP4_MAPT_ICMP_NEXT_IP6_LOOKUP,
+  IP4_MAPT_ICMP_NEXT_IP6_REWRITE,
   IP4_MAPT_ICMP_NEXT_IP6_FRAG,
   IP4_MAPT_ICMP_NEXT_DROP,
   IP4_MAPT_ICMP_N_NEXT
@@ -37,6 +38,7 @@ typedef enum
 typedef enum
 {
   IP4_MAPT_TCP_UDP_NEXT_IP6_LOOKUP,
+  IP4_MAPT_TCP_UDP_NEXT_IP6_REWRITE,
   IP4_MAPT_TCP_UDP_NEXT_IP6_FRAG,
   IP4_MAPT_TCP_UDP_NEXT_DROP,
   IP4_MAPT_TCP_UDP_N_NEXT
@@ -45,6 +47,7 @@ typedef enum
 typedef enum
 {
   IP4_MAPT_FRAGMENTED_NEXT_IP6_LOOKUP,
+  IP4_MAPT_FRAGMENTED_NEXT_IP6_REWRITE,
   IP4_MAPT_FRAGMENTED_NEXT_IP6_FRAG,
   IP4_MAPT_FRAGMENTED_NEXT_DROP,
   IP4_MAPT_FRAGMENTED_N_NEXT
@@ -206,6 +209,11 @@ ip4_map_t_icmp (vlib_main_t * vm,
 	      vnet_buffer (p0)->ip_frag.next_index = IP6_FRAG_NEXT_IP6_LOOKUP;
 	      next0 = IP4_MAPT_ICMP_NEXT_IP6_FRAG;
 	    }
+	  else
+	    {
+	      next0 = ip4_map_ip6_lookup_bypass (p0, NULL) ?
+		IP4_MAPT_ICMP_NEXT_IP6_REWRITE : next0;
+	    }
 	err0:
 	  if (PREDICT_TRUE (error0 == MAP_ERROR_NONE))
 	    {
@@ -325,6 +333,11 @@ ip4_map_t_fragmented (vlib_main_t * vm,
 		    IP6_FRAG_NEXT_IP6_LOOKUP;
 		  next0 = IP4_MAPT_FRAGMENTED_NEXT_IP6_FRAG;
 		}
+	      else
+		{
+		  next0 = ip4_map_ip6_lookup_bypass (p0, NULL) ?
+		    IP4_MAPT_FRAGMENTED_NEXT_IP6_REWRITE : next0;
+		}
 	    }
 
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -491,6 +504,11 @@ ip4_map_t_tcp_udp (vlib_main_t * vm,
 		    IP6_FRAG_NEXT_IP6_LOOKUP;
 		  next0 = IP4_MAPT_TCP_UDP_NEXT_IP6_FRAG;
 		}
+	      else
+		{
+		  next0 = ip4_map_ip6_lookup_bypass (p0, NULL) ?
+		    IP4_MAPT_TCP_UDP_NEXT_IP6_REWRITE : next0;
+		}
 	    }
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
 					   to_next, n_left_to_next, pi0,
@@ -692,6 +710,7 @@ VLIB_REGISTER_NODE(ip4_map_t_fragmented_node) = {
   .n_next_nodes = IP4_MAPT_FRAGMENTED_N_NEXT,
   .next_nodes = {
       [IP4_MAPT_FRAGMENTED_NEXT_IP6_LOOKUP] = "ip6-lookup",
+      [IP4_MAPT_FRAGMENTED_NEXT_IP6_REWRITE] = "ip6-load-balance",
       [IP4_MAPT_FRAGMENTED_NEXT_IP6_FRAG] = IP6_FRAG_NODE_NAME,
       [IP4_MAPT_FRAGMENTED_NEXT_DROP] = "error-drop",
   },
@@ -712,6 +731,7 @@ VLIB_REGISTER_NODE(ip4_map_t_icmp_node) = {
   .n_next_nodes = IP4_MAPT_ICMP_N_NEXT,
   .next_nodes = {
       [IP4_MAPT_ICMP_NEXT_IP6_LOOKUP] = "ip6-lookup",
+      [IP4_MAPT_ICMP_NEXT_IP6_REWRITE] = "ip6-load-balance",
       [IP4_MAPT_ICMP_NEXT_IP6_FRAG] = IP6_FRAG_NODE_NAME,
       [IP4_MAPT_ICMP_NEXT_DROP] = "error-drop",
   },
@@ -732,6 +752,7 @@ VLIB_REGISTER_NODE(ip4_map_t_tcp_udp_node) = {
   .n_next_nodes = IP4_MAPT_TCP_UDP_N_NEXT,
   .next_nodes = {
       [IP4_MAPT_TCP_UDP_NEXT_IP6_LOOKUP] = "ip6-lookup",
+      [IP4_MAPT_TCP_UDP_NEXT_IP6_REWRITE] = "ip6-load-balance",
       [IP4_MAPT_TCP_UDP_NEXT_IP6_FRAG] = IP6_FRAG_NODE_NAME,
       [IP4_MAPT_TCP_UDP_NEXT_DROP] = "error-drop",
   },
diff --git a/src/plugins/map/ip6_map.c b/src/plugins/map/ip6_map.c
index d9db602bad8..303ccf00ead 100644
--- a/src/plugins/map/ip6_map.c
+++ b/src/plugins/map/ip6_map.c
@@ -149,20 +149,6 @@ ip6_map_security_check (map_domain_t * d, ip4_header_t * ip4,
     }
 }
 
-static_always_inline bool
-ip6_map_ip4_lookup_bypass (vlib_buffer_t * p0, ip4_header_t * ip)
-{
-#ifdef MAP_SKIP_IP6_LOOKUP
-  if (FIB_NODE_INDEX_INVALID != pre_resolved[FIB_PROTOCOL_IP4].fei)
-    {
-      vnet_buffer (p0)->ip.adj_index[VLIB_TX] =
-	pre_resolved[FIB_PROTOCOL_IP4].dpo.dpoi_index;
-      return (true);
-    }
-#endif
-  return (false);
-}
-
 /*
  * ip6_map
  */
diff --git a/src/plugins/map/ip6_map_t.c b/src/plugins/map/ip6_map_t.c
index 5e2b63def8d..6757163bb1e 100644
--- a/src/plugins/map/ip6_map_t.c
+++ b/src/plugins/map/ip6_map_t.c
@@ -30,6 +30,7 @@ typedef enum
 typedef enum
 {
   IP6_MAPT_ICMP_NEXT_IP4_LOOKUP,
+  IP6_MAPT_ICMP_NEXT_IP4_REWRITE,
   IP6_MAPT_ICMP_NEXT_IP4_FRAG,
   IP6_MAPT_ICMP_NEXT_DROP,
   IP6_MAPT_ICMP_N_NEXT
@@ -38,6 +39,7 @@ typedef enum
 typedef enum
 {
   IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP,
+  IP6_MAPT_TCP_UDP_NEXT_IP4_REWRITE,
   IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG,
   IP6_MAPT_TCP_UDP_NEXT_DROP,
   IP6_MAPT_TCP_UDP_N_NEXT
@@ -46,6 +48,7 @@ typedef enum
 typedef enum
 {
   IP6_MAPT_FRAGMENTED_NEXT_IP4_LOOKUP,
+  IP6_MAPT_FRAGMENTED_NEXT_IP4_REWRITE,
   IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG,
   IP6_MAPT_FRAGMENTED_NEXT_DROP,
   IP6_MAPT_FRAGMENTED_N_NEXT
@@ -211,6 +214,11 @@ ip6_map_t_icmp (vlib_main_t * vm,
 	      vnet_buffer (p0)->ip_frag.next_index = IP4_FRAG_NEXT_IP4_LOOKUP;
 	      next0 = IP6_MAPT_ICMP_NEXT_IP4_FRAG;
 	    }
+	  else
+	    {
+	      next0 = ip6_map_ip4_lookup_bypass (p0, NULL) ?
+		IP6_MAPT_ICMP_NEXT_IP4_REWRITE : next0;
+	    }
 	err0:
 	  if (PREDICT_TRUE (error0 == MAP_ERROR_NONE))
 	    {
@@ -311,8 +319,7 @@ ip6_map_t_fragmented (vlib_main_t * vm,
 	  n_left_from -= 1;
 	  to_next += 1;
 	  n_left_to_next -= 1;
-
-	  next0 = IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP;
+	  next0 = IP6_MAPT_FRAGMENTED_NEXT_IP4_LOOKUP;
 	  p0 = vlib_get_buffer (vm, pi0);
 
 	  if (map_ip6_to_ip4_fragmented (p0))
@@ -330,6 +337,11 @@ ip6_map_t_fragmented (vlib_main_t * vm,
 		    IP4_FRAG_NEXT_IP4_LOOKUP;
 		  next0 = IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG;
 		}
+	      else
+		{
+		  next0 = ip6_map_ip4_lookup_bypass (p0, NULL) ?
+		    IP6_MAPT_FRAGMENTED_NEXT_IP4_REWRITE : next0;
+		}
 	    }
 
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -495,6 +507,11 @@ ip6_map_t_tcp_udp (vlib_main_t * vm,
 		    IP4_FRAG_NEXT_IP4_LOOKUP;
 		  next0 = IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG;
 		}
+	      else
+		{
+		  next0 = ip6_map_ip4_lookup_bypass (p0, NULL) ?
+		    IP6_MAPT_TCP_UDP_NEXT_IP4_REWRITE : next0;
+		}
 	    }
 
 	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
@@ -729,6 +746,7 @@ VLIB_REGISTER_NODE(ip6_map_t_fragmented_node) = {
   .next_nodes =
   {
     [IP6_MAPT_FRAGMENTED_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [IP6_MAPT_FRAGMENTED_NEXT_IP4_REWRITE] = "ip4-load-balance",
     [IP6_MAPT_FRAGMENTED_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
     [IP6_MAPT_FRAGMENTED_NEXT_DROP] = "error-drop",
   },
@@ -750,6 +768,7 @@ VLIB_REGISTER_NODE(ip6_map_t_icmp_node) = {
   .next_nodes =
   {
     [IP6_MAPT_ICMP_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [IP6_MAPT_ICMP_NEXT_IP4_REWRITE] = "ip4-load-balance",
     [IP6_MAPT_ICMP_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
     [IP6_MAPT_ICMP_NEXT_DROP] = "error-drop",
   },
@@ -771,6 +790,7 @@ VLIB_REGISTER_NODE(ip6_map_t_tcp_udp_node) = {
   .next_nodes =
   {
     [IP6_MAPT_TCP_UDP_NEXT_IP4_LOOKUP] = "ip4-lookup",
+    [IP6_MAPT_TCP_UDP_NEXT_IP4_REWRITE] = "ip4-load-balance",
     [IP6_MAPT_TCP_UDP_NEXT_IP4_FRAG] = IP4_FRAG_NODE_NAME,
     [IP6_MAPT_TCP_UDP_NEXT_DROP] = "error-drop",
   },
diff --git a/src/plugins/map/map.h b/src/plugins/map/map.h
index a65a16a06d5..91732390cd2 100644
--- a/src/plugins/map/map.h
+++ b/src/plugins/map/map.h
@@ -673,6 +673,34 @@ map_mss_clamping (tcp_header_t * tcp, ip_csum_t * sum, u16 mss_clamping)
     }
 }
 
+static_always_inline bool
+ip4_map_ip6_lookup_bypass (vlib_buffer_t * p0, ip4_header_t * ip)
+{
+#ifdef MAP_SKIP_IP6_LOOKUP
+  if (FIB_NODE_INDEX_INVALID != pre_resolved[FIB_PROTOCOL_IP6].fei)
+    {
+      vnet_buffer (p0)->ip.adj_index[VLIB_TX] =
+	pre_resolved[FIB_PROTOCOL_IP6].dpo.dpoi_index;
+      return (true);
+    }
+#endif
+  return (false);
+}
+
+static_always_inline bool
+ip6_map_ip4_lookup_bypass (vlib_buffer_t * p0, ip4_header_t * ip)
+{
+#ifdef MAP_SKIP_IP6_LOOKUP
+  if (FIB_NODE_INDEX_INVALID != pre_resolved[FIB_PROTOCOL_IP4].fei)
+    {
+      vnet_buffer (p0)->ip.adj_index[VLIB_TX] =
+	pre_resolved[FIB_PROTOCOL_IP4].dpo.dpoi_index;
+      return (true);
+    }
+#endif
+  return (false);
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/plugins/map/test/test_map.py b/src/plugins/map/test/test_map.py
index f1388b39c65..31575fa58ca 100644
--- a/src/plugins/map/test/test_map.py
+++ b/src/plugins/map/test/test_map.py
@@ -35,6 +35,8 @@ class TestMAP(VppTestCase):
         self.pg0.admin_up()
         self.pg0.config_ip4()
         self.pg0.resolve_arp()
+        self.pg0.generate_remote_hosts(2)
+        self.pg0.configure_ipv4_neighbors()
 
         # pg1 is 'outside' IPv6
         self.pg1.admin_up()
@@ -432,6 +434,86 @@ class TestMAP(VppTestCase):
         for p in rx:
             self.validate(p[1], p4_translated)
 
+    def test_map_t_pre_resolve(self):
+        """ MAP-T pre-resolve"""
+
+        # Add a domain that maps from pg0 to pg1
+        map_dst = '2001:db8::/32'
+        map_src = '1234:5678:90ab:cdef::/64'
+        ip4_pfx = '192.168.0.0/24'
+        tag = 'MAP-T Test Domain.'
+
+        self.vapi.map_add_domain(ip6_prefix=map_dst,
+                                 ip4_prefix=ip4_pfx,
+                                 ip6_src=map_src,
+                                 ea_bits_len=16,
+                                 psid_offset=6,
+                                 psid_length=4,
+                                 mtu=1500,
+                                 tag=tag)
+
+        # Enable MAP-T on interfaces.
+        self.vapi.map_if_enable_disable(is_enable=1,
+                                        sw_if_index=self.pg0.sw_if_index,
+                                        is_translation=1)
+        self.vapi.map_if_enable_disable(is_enable=1,
+                                        sw_if_index=self.pg1.sw_if_index,
+                                        is_translation=1)
+
+        # Enable pre-resolve option
+        self.vapi.map_param_add_del_pre_resolve(ip4_nh_address="10.1.2.3",
+                                                ip6_nh_address="4001::1",
+                                                is_add=1)
+
+        # Add a route to 4001::1 and expect the translated traffic to be
+        # sent via that route next-hop.
+        pre_res_route6 = VppIpRoute(self, "4001::1", 128,
+                                    [VppRoutePath(self.pg1.remote_hosts[2].ip6,
+                                                  self.pg1.sw_if_index)])
+        pre_res_route6.add_vpp_config()
+
+        # Add a route to 10.1.2.3 and expect the "untranslated" traffic to be
+        # sent via that route next-hop.
+        pre_res_route4 = VppIpRoute(self, "10.1.2.3", 32,
+                                    [VppRoutePath(self.pg0.remote_hosts[1].ip4,
+                                                  self.pg0.sw_if_index)])
+        pre_res_route4.add_vpp_config()
+
+        # Send an IPv4 packet that will be translated
+        p_ether = Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+        p_ip4 = IP(src=self.pg0.remote_ip4, dst='192.168.0.1')
+        payload = TCP(sport=0xabcd, dport=0xabcd)
+        p4 = (p_ether / p_ip4 / payload)
+
+        p6_translated = (IPv6(src="1234:5678:90ab:cdef:ac:1001:200:0",
+                              dst="2001:db8:1f0::c0a8:1:f") / payload)
+        p6_translated.hlim -= 1
+
+        rx = self.send_and_expect(self.pg0, p4*1, self.pg1)
+        for p in rx:
+            self.assertEqual(p[Ether].dst, self.pg1.remote_hosts[2].mac)
+            self.validate(p[1], p6_translated)
+
+        # Send back an IPv6 packet that will be "untranslated"
+        p_ether6 = Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+        p_ip6 = IPv6(src='2001:db8:1f0::c0a8:1:f',
+                     dst='1234:5678:90ab:cdef:ac:1001:200:0')
+        p6 = (p_ether6 / p_ip6 / payload)
+
+        p4_translated = (IP(src='192.168.0.1',
+                            dst=self.pg0.remote_ip4) / payload)
+        p4_translated.id = 0
+        p4_translated.ttl -= 1
+
+        rx = self.send_and_expect(self.pg1, p6*1, self.pg0)
+        for p in rx:
+            self.assertEqual(p[Ether].dst, self.pg0.remote_hosts[1].mac)
+            self.validate(p[1], p4_translated)
+
+        # Cleanup pre-resolve option
+        self.vapi.map_param_add_del_pre_resolve(ip4_nh_address="10.1.2.3",
+                                                ip6_nh_address="4001::1",
+                                                is_add=0)
 
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)