bridge: Tolerate missing Port and Interface records for local port.

Until now, ovs-vswitchd has been unable to configure IP addresses and
routes for bridges whose Bridge records lack a Port and an Interface
record for the bridge's local port (e.g. OFPP_LOCAL, the port with the
same name as the bridge itself).  When such a bridge was reconfigured,
ovs-vswitchd would output a log message that worried people.

This commit fixes the internal limitation that led to the message being
printed.

Bug #5385.

lib/ovsdb-idl.c

@@ -1108,6 +1108,15 @@ ovsdb_idl_get(const struct ovsdb_idl_row *row,
 
     return ovsdb_idl_read(row, column);
 }
+
+/* Returns false if 'row' was obtained from the IDL, true if it was initialized
+ * to all-zero-bits by some other entity.  If 'row' was set up some other way
+ * then the return value is indeterminate. */
+bool
+ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *row)
+{
+    return row->table == NULL;
+}
 
 /* Transactions. */
 

lib/ovsdb-idl.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2009, 2010 Nicira Networks.
+/* Copyright (c) 2009, 2010, 2011 Nicira Networks.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -105,6 +105,8 @@ const struct ovsdb_datum *ovsdb_idl_get(const struct ovsdb_idl_row *,
                                         const struct ovsdb_idl_column *,
                                         enum ovsdb_atomic_type key_type,
                                         enum ovsdb_atomic_type value_type);
+
+bool ovsdb_idl_row_is_synthetic(const struct ovsdb_idl_row *);
 
 /* Transactions. */
 

vswitchd/bridge.c

@@ -185,6 +185,11 @@ struct bridge {
 
     /* Port mirroring. */
     struct mirror *mirrors[MAX_MIRRORS];
+
+    /* Synthetic local port if necessary. */
+    struct ovsrec_port synth_local_port;
+    struct ovsrec_interface synth_local_iface;
+    struct ovsrec_interface *synth_local_ifacep;
 };
 
 /* List of all bridges. */
@@ -264,6 +269,7 @@ static void iface_update_qos(struct iface *, const struct ovsrec_qos *);
 static void iface_update_cfm(struct iface *);
 static bool iface_refresh_cfm_stats(struct iface *iface);
 static bool iface_get_carrier(const struct iface *);
+static bool iface_is_synthetic(const struct iface *);
 
 static void shash_from_ovs_idl_map(char **keys, char **values, size_t n,
                                    struct shash *);
@@ -1140,6 +1146,10 @@ iface_refresh_status(struct iface *iface)
     int64_t mtu_64;
     int error;
 
+    if (iface_is_synthetic(iface)) {
+        return;
+    }
+
     shash_init(&sh);
 
     if (!netdev_get_status(iface->netdev, &sh)) {
@@ -1282,6 +1292,10 @@ iface_refresh_stats(struct iface *iface)
 
     struct netdev_stats stats;
 
+    if (iface_is_synthetic(iface)) {
+        return;
+    }
+
     /* Intentionally ignore return value, since errors will set 'stats' to
      * all-1s, and we will deal with that correctly below. */
     netdev_get_stats(iface->netdev, &stats);
@@ -1716,6 +1730,7 @@ bridge_destroy(struct bridge *br)
         hmap_destroy(&br->ifaces);
         hmap_destroy(&br->ports);
         shash_destroy(&br->iface_by_name);
+        free(br->synth_local_iface.type);
         free(br->name);
         free(br);
     }
@@ -1841,22 +1856,28 @@ bridge_reconfigure_one(struct bridge *br)
                       br->name, name);
         }
     }
+    if (!shash_find(&new_ports, br->name)) {
+        struct dpif_port dpif_port;
+        char *type;
 
-    /* If we have a controller, then we need a local port.  Complain if the
-     * user didn't specify one.
-     *
-     * XXX perhaps we should synthesize a port ourselves in this case. */
-    if (bridge_get_controllers(br, NULL)) {
-        char local_name[IF_NAMESIZE];
-        int error;
+        VLOG_WARN("bridge %s: no port named %s, synthesizing one",
+                  br->name, br->name);
 
-        error = dpif_port_get_name(br->dpif, ODPP_LOCAL,
-                                   local_name, sizeof local_name);
-        if (!error && !shash_find(&new_ports, local_name)) {
-            VLOG_WARN("bridge %s: controller specified but no local port "
-                      "(port named %s) defined",
-                      br->name, local_name);
-        }
+        dpif_port_query_by_number(br->dpif, ODPP_LOCAL, &dpif_port);
+        type = xstrdup(dpif_port.type ? dpif_port.type : "internal");
+        dpif_port_destroy(&dpif_port);
+
+        br->synth_local_port.interfaces = &br->synth_local_ifacep;
+        br->synth_local_port.n_interfaces = 1;
+        br->synth_local_port.name = br->name;
+
+        br->synth_local_iface.name = br->name;
+        free(br->synth_local_iface.type);
+        br->synth_local_iface.type = type;
+
+        br->synth_local_ifacep = &br->synth_local_iface;
+
+        shash_add(&new_ports, br->name, &br->synth_local_port);
     }
 
     /* Get rid of deleted ports.
@@ -3405,7 +3426,7 @@ iface_set_mac(struct iface *iface)
 static void
 iface_set_ofport(const struct ovsrec_interface *if_cfg, int64_t ofport)
 {
-    if (if_cfg) {
+    if (if_cfg && !ovsdb_idl_row_is_synthetic(&if_cfg->header_)) {
         ovsrec_interface_set_ofport(if_cfg, &ofport, 1);
     }
 }
@@ -3565,6 +3586,14 @@ iface_get_carrier(const struct iface *iface)
     /* XXX */
     return netdev_get_carrier(iface->netdev);
 }
+
+/* Returns true if 'iface' is synthetic, that is, if we constructed it locally
+ * instead of obtaining it from the database. */
+static bool
+iface_is_synthetic(const struct iface *iface)
+{
+    return ovsdb_idl_row_is_synthetic(&iface->cfg->header_);
+}
 
 /* Port mirroring. */