ofproto-dpif: Fix tunnel with different name del/add failure.

Reproduce:
  ovs-vsctl add-port br-int p0 \
    -- set interface p0 type=vxlan options:remote_ip=10.10.10.1

  sleep 2

  ovs-vsctl --if-exists del-port p0 \
    -- add-port br-int p1 \
    -- set interface p1 type=vxlan options:remote_ip=10.10.10.1
  ovs-vsctl: Error detected while setting up 'p1': could not add
  network device p1 to ofproto (File exists).

vswitchd log:
  bridge|INFO|bridge br-int: added interface p0 on port 1106
  bridge|INFO|bridge br-int: deleted interface p0 on port 1106
  tunnel|WARN|p1: attempting to add tunnel port with same config as
              port 'p0' (::->10.10.10.1, key=0, legacy_l2, dp port=122)
  ofproto|WARN|br-int: could not add port p1 (File exists)
  bridge|WARN|could not add network device p1 to ofproto (File exists)

CallTrace:
  bridge_reconfigure
    bridge_del_ports
      port_destroy
        iface_destroy__
          netdev_remove		<------ netdev p0 removed
    bridge_delete_or_reconfigure_ports
      OFPROTO_PORT_FOR_EACH
        ofproto_port_dump_next
          port_dump_next
          port_query_by_name	<------ netdev_shash do not contain p0
        ofproto_port_del	<------ p0 do not del in ofproto
    bridge_add_ports
      bridge_add_ports__
        iface_create
          iface_do_create
            ofproto_port_add	<------ p1 add failed

Fixes: fe83f81 ("netdev: Remove netdev from global shash when the user is changing interface configuration.")
Acked-by: Han Zhou <[email protected]>
Tested-by: Han Zhou <[email protected]>
Signed-off-by: Tao Liu <[email protected]>
Signed-off-by: Ilya Maximets <[email protected]>

ofproto/ofproto-dpif.c

@@ -3904,15 +3904,21 @@ port_query_by_name(const struct ofproto *ofproto_, const char *devname,
     int error;
 
     if (sset_contains(&ofproto->ghost_ports, devname)) {
-        const char *type = netdev_get_type_from_name(devname);
-
         /* We may be called before ofproto->up.port_by_name is populated with
          * the appropriate ofport.  For this reason, we must get the name and
-         * type from the netdev layer directly. */
-        if (type) {
-            const struct ofport *ofport;
+         * type from the netdev layer directly.
+         * However, when a port deleted, the corresponding netdev is also
+         * removed from netdev_shash. netdev_get_type_from_name returns NULL
+         * in such case and we should try to get type from ofport->netdev. */
+        const char *type = netdev_get_type_from_name(devname);
+        const struct ofport *ofport =
+                        shash_find_data(&ofproto->up.port_by_name, devname);
 
-            ofport = shash_find_data(&ofproto->up.port_by_name, devname);
+        if (!type && ofport && ofport->netdev) {
+            type = netdev_get_type(ofport->netdev);
+        }
+
+        if (type) {
             ofproto_port->ofp_port = ofport ? ofport->ofp_port : OFPP_NONE;
             ofproto_port->name = xstrdup(devname);
             ofproto_port->type = xstrdup(type);

tests/tunnel.at

@@ -1269,6 +1269,18 @@ OVS_APP_EXIT_AND_WAIT([ovs-vswitchd])
 OVS_APP_EXIT_AND_WAIT([ovsdb-server])]
 AT_CLEANUP
 
+AT_SETUP([tunnel - re-create port with different name])
+OVS_VSWITCHD_START(
+  [add-port br0 p0 -- set int p0 type=vxlan options:remote_ip=10.10.10.1])
+
+AT_CHECK([ovs-vsctl --if-exists del-port p0 -- \
+          add-port br0 p1 -- \
+          set int p1 type=vxlan options:remote_ip=10.10.10.1])
+
+OVS_APP_EXIT_AND_WAIT([ovs-vswitchd])
+OVS_APP_EXIT_AND_WAIT([ovsdb-server])]
+AT_CLEANUP
+
 AT_SETUP([tunnel - SRV6 basic])
 OVS_VSWITCHD_START([add-port br0 p1 -- set Interface p1 type=dummy \
                     ofport_request=1 \