tnl-neigh-cache: Purge learnt neighbors when port/bridge is deleted

Say an ARP entry is learnt on a OVS port and when such a port is deleted,
learnt entry should be removed from the port. It would have be aged out after
ARP ageout time. This code will clean up immediately.

Added test case(tunnel - neighbor entry add and deletion) in tunnel.at, to
verify neighbors are added and removed on deletion of a ports and bridges.

Discussion for this addition is at:
https://mail.openvswitch.org/pipermail/ovs-discuss/2019-June/048754.html

Signed-off-by: Vasu Dasari <vdasari@gmail.com>
Reviewed-by: Flavio Fernandes <flavio@flaviof.com>
Reviewed-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>

2 files changed, 21 insertions, 0 deletions

diff --git a/lib/tnl-neigh-cache.c b/lib/tnl-neigh-cache.c
index b28f9f1bb..5bda4af7e 100644
--- a/lib/tnl-neigh-cache.c
+++ b/lib/tnl-neigh-cache.c
@@ -220,6 +220,26 @@ tnl_neigh_cache_run(void)
     }
 }
 
+void
+tnl_neigh_flush(const char br_name[IFNAMSIZ])
+{
+    struct tnl_neigh_entry *neigh;
+    bool changed = false;
+
+    ovs_mutex_lock(&mutex);
+    CMAP_FOR_EACH (neigh, cmap_node, &table) {
+        if (!strcmp(neigh->br_name, br_name)) {
+            tnl_neigh_delete(neigh);
+            changed = true;
+        }
+    }
+    ovs_mutex_unlock(&mutex);
+
+    if (changed) {
+        seq_change(tnl_conf_seq);
+    }
+}
+
 static void
 tnl_neigh_cache_flush(struct unixctl_conn *conn, int argc OVS_UNUSED,
                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
diff --git a/lib/tnl-neigh-cache.h b/lib/tnl-neigh-cache.h
index fee8e6a6f..ded9c2f86 100644
--- a/lib/tnl-neigh-cache.h
+++ b/lib/tnl-neigh-cache.h
@@ -37,5 +37,6 @@ int tnl_neigh_lookup(const char dev_name[], const struct in6_addr *dst,
                      struct eth_addr *mac);
 void tnl_neigh_cache_init(void);
 void tnl_neigh_cache_run(void);
+void tnl_neigh_flush(const char dev_name[]);
 
 #endif