zebra: Refactor kernel_rtm to be a bit smarter about how it handles options

[mirror_frr.git] / zebra / interface.c

diff --git a/zebra/interface.c b/zebra/interface.c
index 5b866baaacdc172b520cb78c7ed62676c539b10c..ac765e7846375a2adc108155e9cd73400eb9c55d 100644 (file)
--- a/zebra/interface.c
+++ b/zebra/interface.c
@@ -806,19 +806,6 @@ static void ipv6_ll_address_to_mac(struct in6_addr *address, uint8_t *mac)
        mac[5] = address->s6_addr[15];
 }
 
-static bool mac_is_same(char *mac1, char *mac2)
-{
-       if (mac1[0] == mac2[0] &&
-           mac1[1] == mac2[1] &&
-           mac1[2] == mac2[2] &&
-           mac1[3] == mac2[3] &&
-           mac1[4] == mac2[4] &&
-           mac1[5] == mac2[5])
-               return true;
-       else
-               return false;
-}
-
 void if_nbr_mac_to_ipv4ll_neigh_update(struct interface *ifp,
                                       char mac[6],
                                       struct in6_addr *address,
@@ -835,19 +822,23 @@ void if_nbr_mac_to_ipv4ll_neigh_update(struct interface *ifp,
        ns_id = zvrf->zns->ns_id;
 
        /*
-        * Remove existed arp record for the interface as netlink
-        * protocol does not have update message types
-        *
-        * supported message types are RTM_NEWNEIGH and RTM_DELNEIGH
+        * Remove and re-add any existing neighbor entry for this address,
+        * since Netlink doesn't currently offer update message types.
         */
-       if (!mac_is_same(zif->neigh_mac, mac)) {
-               kernel_neigh_update(0, ifp->ifindex, ipv4_ll.s_addr,
-                                   mac, 6, ns_id);
+       kernel_neigh_update(0, ifp->ifindex, ipv4_ll.s_addr, mac, 6, ns_id);
 
-               /* Add arp record */
-               kernel_neigh_update(add, ifp->ifindex, ipv4_ll.s_addr,
-                                   mac, 6, ns_id);
-       }
+       /* Add new neighbor entry.
+        *
+        * We force installation even if current neighbor entry is the same.
+        * Since this function is used to refresh our MAC entries after an
+        * interface flap, if we don't force in our custom entries with their
+        * state set to PERMANENT or REACHABLE then the kernel will attempt to
+        * resolve our leftover entries, fail, mark them unreachable and then
+        * they'll be useless to us.
+        */
+       if (add)
+               kernel_neigh_update(add, ifp->ifindex, ipv4_ll.s_addr, mac, 6,
+                                   ns_id);
 
        memcpy(&zif->neigh_mac[0], &mac[0], 6);