bridge: Enable RSTP if both STP and RSTP are enabled.

Until now, if both STP and RSTP were enabled, ovs-vswitchd would actually
enable only the one it first noticed to be enabled, and actually turn off
the setting for the other one in the database (!).  This doesn't match
ovs-vswitchd behavior for other contradictory configurations, so this
commit changes its behavior so that, if both are enabled, RSTP takes
precedence.

Reported-by: Daniele Venturino <[email protected]>
Signed-off-by: Ben Pfaff <[email protected]>
Acked-by: Ansis Atteka <[email protected]>

vswitchd/bridge.c

@@ -248,8 +248,7 @@ static void bridge_configure_mac_table(struct bridge *);
 static void bridge_configure_mcast_snooping(struct bridge *);
 static void bridge_configure_sflow(struct bridge *, int *sflow_bridge_number);
 static void bridge_configure_ipfix(struct bridge *);
-static void bridge_configure_stp(struct bridge *);
-static void bridge_configure_rstp(struct bridge *);
+static void bridge_configure_spanning_tree(struct bridge *);
 static void bridge_configure_tables(struct bridge *);
 static void bridge_configure_dp_desc(struct bridge *);
 static void bridge_configure_aa(struct bridge *);
@@ -668,8 +667,7 @@ bridge_reconfigure(const struct ovsrec_open_vswitch *ovs_cfg)
         bridge_configure_netflow(br);
         bridge_configure_sflow(br, &sflow_bridge_number);
         bridge_configure_ipfix(br);
-        bridge_configure_stp(br);
-        bridge_configure_rstp(br);
+        bridge_configure_spanning_tree(br);
         bridge_configure_tables(br);
         bridge_configure_dp_desc(br);
         bridge_configure_aa(br);
@@ -1444,18 +1442,10 @@ port_configure_rstp(const struct ofproto *ofproto, struct port *port,
 
 /* Set spanning tree configuration on 'br'. */
 static void
-bridge_configure_stp(struct bridge *br)
+bridge_configure_stp(struct bridge *br, bool enable_stp)
 {
-    struct ofproto_rstp_status rstp_status;
-
-    ofproto_get_rstp_status(br->ofproto, &rstp_status);
-    if (!br->cfg->stp_enable) {
-        ofproto_set_stp(br->ofproto, NULL);
-    } else if (rstp_status.enabled) {
-        /* Do not activate STP if RSTP is enabled. */
-        VLOG_ERR("STP cannot be enabled if RSTP is running.");
+    if (!enable_stp) {
         ofproto_set_stp(br->ofproto, NULL);
-        ovsrec_bridge_set_stp_enable(br->cfg, false);
     } else {
         struct ofproto_stp_settings br_s;
         const char *config_str;
@@ -1546,18 +1536,10 @@ bridge_configure_stp(struct bridge *br)
 }
 
 static void
-bridge_configure_rstp(struct bridge *br)
+bridge_configure_rstp(struct bridge *br, bool enable_rstp)
 {
-    struct ofproto_stp_status stp_status;
-
-    ofproto_get_stp_status(br->ofproto, &stp_status);
-    if (!br->cfg->rstp_enable) {
+    if (!enable_rstp) {
         ofproto_set_rstp(br->ofproto, NULL);
-    } else if (stp_status.enabled) {
-        /* Do not activate RSTP if STP is enabled. */
-        VLOG_ERR("RSTP cannot be enabled if STP is running.");
-        ofproto_set_rstp(br->ofproto, NULL);
-        ovsrec_bridge_set_rstp_enable(br->cfg, false);
     } else {
         struct ofproto_rstp_settings br_s;
         const char *config_str;
@@ -1652,6 +1634,22 @@ bridge_configure_rstp(struct bridge *br)
     }
 }
 
+static void
+bridge_configure_spanning_tree(struct bridge *br)
+{
+    bool enable_rstp = br->cfg->rstp_enable;
+    bool enable_stp = br->cfg->stp_enable;
+
+    if (enable_rstp && enable_stp) {
+        VLOG_WARN("%s: RSTP and STP are mutually exclusive but both are "
+                  "configured; enabling RSTP", br->name);
+        enable_stp = false;
+    }
+
+    bridge_configure_stp(br, enable_stp);
+    bridge_configure_rstp(br, enable_rstp);
+}
+
 static bool
 bridge_has_bond_fake_iface(const struct bridge *br, const char *name)
 {