1 files changed, 131 insertions, 0 deletions
diff --git a/alias.c b/alias.c
new file mode 100644
index 0000000..338ece6
--- /dev/null
+++ b/alias.c
@@ -0,0 +1,131 @@
+/*
+ * netifd - network interface daemon
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "netifd.h"
+#include "device.h"
+
+static struct avl_tree aliases;
+
+struct alias_device {
+	struct avl_node avl;
+	struct device dev;
+	struct device_user dep;
+	bool cleanup;
+	char name[];
+};
+
+static const struct device_type alias_device_type;
+
+static int
+alias_device_set_state(struct device *dev, bool state)
+{
+	struct alias_device *alias;
+
+	alias = container_of(dev, struct alias_device, dev);
+	if (!alias->dep.dev)
+		return -1;
+
+	if (state)
+		return device_claim(&alias->dep);
+
+	device_release(&alias->dep);
+	if (alias->cleanup)
+		device_remove_user(&alias->dep);
+	return 0;
+}
+
+static struct device *
+alias_device_create(const char *name, struct blob_attr *attr)
+{
+	struct alias_device *alias;
+
+	alias = calloc(1, sizeof(*alias) + strlen(name) + 1);
+	strcpy(alias->name, name);
+	alias->dev.set_state = alias_device_set_state;
+	alias->dev.hidden = true;
+	device_init_virtual(&alias->dev, &alias_device_type, NULL);
+	alias->avl.key = alias->name;
+	avl_insert(&aliases, &alias->avl);
+
+	return &alias->dev;
+}
+
+static void alias_device_free(struct device *dev)
+{
+	struct alias_device *alias;
+
+	alias = container_of(dev, struct alias_device, dev);
+	avl_delete(&aliases, &alias->avl);
+	free(alias);
+}
+
+static const struct device_type alias_device_type = {
+	.name = "Network alias",
+	.create = alias_device_create,
+	.free = alias_device_free,
+};
+
+void
+alias_notify_device(const char *name, struct device *dev)
+{
+	struct alias_device *alias;
+
+	device_lock();
+
+	alias = avl_find_element(&aliases, name, alias, avl);
+	if (!alias)
+		return;
+
+	alias->cleanup = !dev;
+	if (dev) {
+		if (dev != alias->dep.dev) {
+			device_remove_user(&alias->dep);
+			strcpy(alias->dev.ifname, dev->ifname);
+			device_add_user(&alias->dep, dev);
+			alias->dev.hidden = false;
+			device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
+		}
+	}
+
+	device_set_present(&alias->dev, !!dev);
+
+	if (!dev && alias->dep.dev && !alias->dep.dev->active) {
+		device_remove_user(&alias->dep);
+		alias->dev.hidden = true;
+		alias->dev.ifname[0] = 0;
+		device_broadcast_event(&alias->dev, DEV_EVENT_UPDATE_IFNAME);
+	}
+
+	device_unlock();
+}
+
+struct device *
+device_alias_get(const char *name)
+{
+	struct alias_device *alias;
+
+	alias = avl_find_element(&aliases, name, alias, avl);
+	if (alias)
+		return &alias->dev;
+
+	return alias_device_create(name, NULL);
+}
+
+static void __init alias_init(void)
+{
+	avl_init(&aliases, avl_strcmp, false, NULL);
+}