bridge: Reconfigure when system interfaces change.

Whenever system interfaces are removed, added or change state, reconfigure
bridge. This allows late interfaces to be added to the datapath when they are
added to the system after ovs-vswitchd is started.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@redhat.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

lib/if-notifier-bsd.c

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include "if-notifier.h"
+#include "rtbsd.h"
+#include "util.h"
+
+struct if_notifier {
+    struct rtbsd_notifier notifier;
+    if_notify_func *cb;
+    void *aux;
+};
+
+static void
+if_notifier_cb(const struct rtbsd_change *change OVS_UNUSED, void *aux)
+{
+    struct if_notifier *notifier;
+    notifier = aux;
+    notifier->cb(notifier->aux);
+}
+
+struct if_notifier *
+if_notifier_create(if_notify_func *cb, void *aux)
+{
+    struct if_notifier *notifier;
+    int ret;
+    notifier = xzalloc(sizeof *notifier);
+    notifier->cb = cb;
+    notifier->aux = aux;
+    ret = rtbsd_notifier_register(&notifier->notifier, if_notifier_cb,
+                                  notifier);
+    if (ret) {
+        free(notifier);
+        return NULL;
+    }
+    return notifier;
+}
+
+void
+if_notifier_destroy(struct if_notifier *notifier)
+{
+    if (notifier) {
+        rtbsd_notifier_unregister(&notifier->notifier);
+        free(notifier);
+    }
+}
+
+void
+if_notifier_run(void)
+{
+    rtbsd_notifier_run();
+}
+
+void
+if_notifier_wait(void)
+{
+    rtbsd_notifier_wait();
+}