IP6 forward: Add ND route when next-hop is unknown link local
[vpp.git] / vnet / vnet / ip / ip6_forward.c
index 5ad26df..80156e0 100644 (file)
@@ -297,6 +297,102 @@ void ip6_add_del_route (ip6_main_t * im, ip6_add_del_route_args_t * a)
   }
 }
 
+u32
+ip6_route_get_next_hop_adj (ip6_main_t * im,
+                           u32 fib_index,
+                           ip6_address_t *next_hop,
+                           u32 next_hop_sw_if_index,
+                           u32 explicit_fib_index)
+{
+  ip_lookup_main_t * lm = &im->lookup_main;
+  vnet_main_t * vnm = vnet_get_main();
+  int is_interface_next_hop;
+  uword * nh_result;
+  u32 nh_adj_index;
+  ip6_fib_t * fib;
+
+  fib = vec_elt_at_index (im->fibs, fib_index);
+
+  is_interface_next_hop = ip6_address_is_zero (next_hop);
+
+  if (is_interface_next_hop)
+    {
+      nh_result = hash_get (im->interface_route_adj_index_by_sw_if_index,
+                           next_hop_sw_if_index);
+      if (nh_result)
+         nh_adj_index = *nh_result;
+      else
+        {
+         ip_adjacency_t * adj;
+         adj = ip_add_adjacency (lm, /* template */ 0, /* block size */ 1,
+                                 &nh_adj_index);
+         ip6_adjacency_set_interface_route (vnm, adj,
+                                            next_hop_sw_if_index, ~0);
+         ip_call_add_del_adjacency_callbacks
+             (lm, next_hop_sw_if_index, /* is_del */ 0);
+         hash_set (im->interface_route_adj_index_by_sw_if_index,
+                   next_hop_sw_if_index, nh_adj_index);
+       }
+    }
+  else if (next_hop_sw_if_index == ~0)
+    {
+      /* next-hop is recursive. we always need a indirect adj
+       * for recursive paths. Any LPM we perform now will give
+       * us a valid adj, but without tracking the next-hop we
+       * have no way to keep it valid.
+       */
+      ip_adjacency_t add_adj;
+      memset (&add_adj, 0, sizeof(add_adj));
+      add_adj.n_adj = 1;
+      add_adj.lookup_next_index = IP_LOOKUP_NEXT_INDIRECT;
+      add_adj.indirect.next_hop.ip6.as_u64[0] = next_hop->as_u64[0];
+      add_adj.indirect.next_hop.ip6.as_u64[1] = next_hop->as_u64[1];
+      add_adj.explicit_fib_index = explicit_fib_index;
+      ip_add_adjacency (lm, &add_adj, 1, &nh_adj_index);
+    }
+  else
+    {
+      BVT(clib_bihash_kv) kv, value;
+
+      /* Look for the interface /128 route */
+      kv.key[0] = next_hop->as_u64[0];
+      kv.key[1] = next_hop->as_u64[1];
+      kv.key[2] = ((u64)((fib - im->fibs))<<32) | 128;
+after_nd:
+      if (BV(clib_bihash_search)(&im->ip6_lookup_table, &kv, &value) < 0)
+        {
+          ip_adjacency_t * adj;
+          nh_adj_index = ip6_fib_lookup_with_table (im, fib_index, next_hop);
+          adj = ip_get_adjacency (lm, nh_adj_index);
+          /* if ND interface adjacencty is present, we need to
+           install ND adjaceny for specific next hop */
+          if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP &&
+              adj->arp.next_hop.ip6.as_u64[0] == 0 &&
+              adj->arp.next_hop.ip6.as_u64[1] == 0)
+            {
+              nh_adj_index = vnet_ip6_neighbor_glean_add(fib_index, next_hop);
+            }
+          else if (next_hop->as_u8[0] == 0xfe)
+            {
+              //Next hop is link-local. No indirect in this case.
+              //Let's add it as a possible neighbor on this interface
+              ip6_address_t null_addr= {};
+              ip6_add_del_route_next_hop (im, IP6_ROUTE_FLAG_ADD,
+                                          next_hop, 128,
+                                          &null_addr, next_hop_sw_if_index,
+                                          1, ~0, fib_index);
+              goto after_nd;
+            }
+        }
+      else
+        {
+          nh_adj_index = value.value;
+        }
+    }
+
+  return (nh_adj_index);
+}
+
 void
 ip6_add_del_route_next_hop (ip6_main_t * im,
                            u32 flags,
@@ -318,9 +414,7 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
   ip_adjacency_t * dst_adj;
   ip_multipath_adjacency_t * old_mp, * new_mp;
   int is_del = (flags & IP6_ROUTE_FLAG_DEL) != 0;
-  int is_interface_next_hop;
   clib_error_t * error = 0;
-  uword * nh_result;
   BVT(clib_bihash_kv) kv, value;
 
   vlib_smp_unsafe_warning();
@@ -333,64 +427,12 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
   fib = vec_elt_at_index (im->fibs, fib_index);
 
   /* Lookup next hop to be added or deleted. */
-  is_interface_next_hop = ip6_address_is_zero (next_hop);
   if (adj_index == (u32)~0)
     {
-      if (is_interface_next_hop)
-        {
-          nh_result = hash_get (im->interface_route_adj_index_by_sw_if_index, 
-                                next_hop_sw_if_index);
-          if (nh_result)
-            nh_adj_index = *nh_result;
-          else
-            {
-              ip_adjacency_t * adj;
-              adj = ip_add_adjacency (lm, /* template */ 0, /* block size */ 1,
-                                      &nh_adj_index);
-              ip6_adjacency_set_interface_route (vnm, adj, 
-                                                 next_hop_sw_if_index, ~0);
-              ip_call_add_del_adjacency_callbacks 
-                (lm, nh_adj_index, /* is_del */ 0);
-              hash_set (im->interface_route_adj_index_by_sw_if_index, 
-                        next_hop_sw_if_index, nh_adj_index);
-            }
-        }
-      else
-        {
-          /* Look for the interface /128 route */
-          kv.key[0] = next_hop->as_u64[0];
-          kv.key[1] = next_hop->as_u64[1];
-          kv.key[2] = ((u64)((fib - im->fibs))<<32) | 128;
-
-          if (BV(clib_bihash_search)(&im->ip6_lookup_table, &kv, &value) < 0)
-          {
-            ip_adjacency_t * adj;
-            nh_adj_index = ip6_fib_lookup_with_table (im, fib_index, next_hop);
-            adj = ip_get_adjacency (lm, nh_adj_index);
-            /* if ND interface adjacencty is present, we need to
-                             install ND adjaceny for specific next hop */
-            if (adj->lookup_next_index == IP_LOOKUP_NEXT_ARP &&
-                adj->arp.next_hop.ip6.as_u64[0] == 0 &&
-                adj->arp.next_hop.ip6.as_u64[1] == 0)
-            {
-              nh_adj_index = vnet_ip6_neighbor_glean_add(fib_index, next_hop);
-            }
-            else
-            {
-             ip_adjacency_t add_adj;
-             memset (&add_adj, 0, sizeof(add_adj));
-             add_adj.n_adj = 1;
-             add_adj.lookup_next_index = IP_LOOKUP_NEXT_INDIRECT;
-             add_adj.indirect.next_hop.ip6.as_u64[0] = next_hop->as_u64[0];
-             add_adj.indirect.next_hop.ip6.as_u64[1] = next_hop->as_u64[1];
-             add_adj.explicit_fib_index = explicit_fib_index;
-             ip_add_adjacency (lm, &add_adj, 1, &nh_adj_index);
-            }
-          }
-          else
-            nh_adj_index = value.value;
-
-        }
+      nh_adj_index = ip6_route_get_next_hop_adj(im, fib_index,
+                                               next_hop,
+                                               next_hop_sw_if_index,
+                                               explicit_fib_index);
     }
   else
     {
@@ -457,8 +499,10 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
      to existing non-multipath adjacency */
   if (dst_adj_index == ~0 && next_hop_weight == 1 && next_hop_sw_if_index == ~0)
   {
-    /* create new adjacency */
+    /* create / delete additional mapping of existing adjacency */
     ip6_add_del_route_args_t a;
+    ip_adjacency_t * nh_adj = ip_get_adjacency (lm, nh_adj_index);
+
     a.table_index_or_table_id = fib_index;
     a.flags = ((is_del ? IP6_ROUTE_FLAG_DEL : IP6_ROUTE_FLAG_ADD)
         | IP6_ROUTE_FLAG_FIB_INDEX
@@ -472,6 +516,9 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
     a.n_add_adj = 0;
 
     ip6_add_del_route (im, &a);
+    /* adjust share count. This cannot be the only use of the adjacency */
+    nh_adj->share_count += is_del ? -1 : 1;
+
     goto done;
   }
 
@@ -500,6 +547,8 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
   if (old_mp != new_mp)
     {
       ip6_add_del_route_args_t a;
+      ip_adjacency_t * adj;
+
       a.table_index_or_table_id = fib_index;
       a.flags = ((is_del ? IP6_ROUTE_FLAG_DEL : IP6_ROUTE_FLAG_ADD)
                 | IP6_ROUTE_FLAG_FIB_INDEX
@@ -512,6 +561,10 @@ ip6_add_del_route_next_hop (ip6_main_t * im,
       a.n_add_adj = 0;
 
       ip6_add_del_route (im, &a);
+
+      adj = ip_get_adjacency (lm, new_mp ? new_mp->adj_index : dst_adj_index);
+      if (adj->n_adj == 1)
+        adj->share_count += is_del ? -1 : 1;
     }
 
  done: