ARP reply: use interface to build rewrite string

Change-Id: I488965e78d0b3291af4c82902098ca666317a22e
Signed-off-by: Neale Ranns <nranns@cisco.com>

diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c
index 8a39400..c8d1578 100644 (file)
--- a/src/vnet/ethernet/arp.c
+++ b/src/vnet/ethernet/arp.c
@@ -787,7 +787,6 @@ typedef enum
   _ (opcode_not_request, "ARP opcode not request")                      \
   _ (proxy_arp_replies_sent, "Proxy ARP replies sent")                 \
   _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
-  _ (missing_interface_address, "ARP missing interface address") \
   _ (gratuitous_arp, "ARP probe or announcement dropped") \
   _ (interface_no_table, "Interface is not mapped to an IP table") \
   _ (interface_not_ip_enabled, "Interface is not IP enabled") \
@@ -906,8 +905,7 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
          fib_node_index_t dst_fei, src_fei;
          fib_prefix_t pfx0;
          fib_entry_flag_t src_flags, dst_flags;
-         ip_adjacency_t *adj0 = NULL;
-         adj_index_t ai;
+         u8 *rewrite0, rewrite0_len;
 
          pi0 = from[0];
          to_next[0] = pi0;
@@ -1105,20 +1103,18 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
              goto drop1;
            }
 
-         /* Send a reply. */
        send_reply:
-         ai = fib_entry_get_adj (src_fei);
-         if (ADJ_INDEX_INVALID != ai)
-           {
-             adj0 = adj_get (ai);
-           }
-         else
-           {
-             error0 = ETHERNET_ARP_ERROR_missing_interface_address;
-             goto drop2;
-           }
+         /* Send a reply.
+            An adjacency to the sender is not always present,
+            so we use the interface to build us a rewrite string
+            which will contain all the necessary tags. */
+         rewrite0 = ethernet_build_rewrite (vnm, sw_if_index0,
+                                            VNET_LINK_ARP,
+                                            eth_rx->src_address);
+         rewrite0_len = vec_len (rewrite0);
+
          /* Figure out how much to rewind current data from adjacency. */
-         vlib_buffer_advance (p0, -adj0->rewrite_header.data_bytes);
+         vlib_buffer_advance (p0, -rewrite0_len);
          eth_tx = vlib_buffer_get_current (p0);
 
          vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
@@ -1143,8 +1139,8 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
          /* the rx nd tx ethernet headers wil overlap in the case
           * when we received a tagged VLAN=0 packet, but we are sending
           * back untagged */
-         memmove (eth_tx->dst_address, eth_rx->src_address, 6);
-         clib_memcpy (eth_tx->src_address, hw_if0->hw_address, 6);
+         clib_memcpy (eth_tx, rewrite0, vec_len (rewrite0));
+         vec_free (rewrite0);
 
          if (NULL == pa)
            {