From e1bdd7ce1e40812b265c295f88c57764fdec8c82 Mon Sep 17 00:00:00 2001
From: Denis Kenzior <denkenz@gmail.com>
Date: Mon, 28 Sep 2015 19:44:26 -0500
Subject: [PATCH] netdev: Add netdev watch infrastructure

---
 src/netdev.c | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/netdev.h | 13 ++++++++
 2 files changed, 101 insertions(+)

diff --git a/src/netdev.c b/src/netdev.c
index 2a9028b7..0f7b48d4 100644
--- a/src/netdev.c
+++ b/src/netdev.c
@@ -39,9 +39,20 @@ struct netdev_data {
 	char ifname[IF_NAMESIZE];
 };
 
+struct netdev_watchlist_item {
+	uint32_t id;
+	netdev_watch_func_t added;
+	netdev_watch_func_t removed;
+	void *userdata;
+	netdev_destroy_func_t destroy;
+};
+
 static struct l_netlink *rtnl = NULL;
 static struct l_hashmap *netdev_list = NULL;
 
+static struct l_queue *netdev_watches = NULL;
+static uint32_t netdev_next_watch_id = 0;
+
 static void do_debug(const char *str, void *user_data)
 {
 	const char *prefix = user_data;
@@ -188,6 +199,79 @@ static void link_notify(uint16_t type, const void *data, uint32_t len,
 	}
 }
 
+static void netdev_watchlist_item_free(void *userdata)
+{
+	struct netdev_watchlist_item *item = userdata;
+
+	if (item->destroy)
+		item->destroy(item->userdata);
+
+	l_free(item);
+}
+
+static bool netdev_watchlist_item_match(const void *a, const void *b)
+{
+	const struct netdev_watchlist_item *item = a;
+	uint32_t id = L_PTR_TO_UINT(b);
+
+	return item->id == id;
+}
+
+uint32_t netdev_watch_add(netdev_watch_func_t added,
+				netdev_watch_func_t removed,
+				void *userdata, netdev_destroy_func_t destroy)
+{
+	struct netdev_watchlist_item *item;
+
+	item = l_new(struct netdev_watchlist_item, 1);
+	item->id = ++netdev_next_watch_id;
+	item->added = added;
+	item->removed = removed;
+	item->userdata = userdata;
+	item->destroy = destroy;
+
+	l_queue_push_tail(netdev_watches, item);
+
+	return item->id;
+}
+
+bool netdev_watch_remove(uint32_t id)
+{
+	struct netdev_watchlist_item *item;
+
+	item = l_queue_remove_if(netdev_watches, netdev_watchlist_item_match,
+							L_UINT_TO_PTR(id));
+	if (!item)
+		return false;
+
+	netdev_watchlist_item_free(item);
+	return true;
+}
+
+void __netdev_watch_call_added(struct netdev *netdev)
+{
+	const struct l_queue_entry *e;
+
+	for (e = l_queue_get_entries(netdev_watches); e; e = e->next) {
+		struct netdev_watchlist_item *item = e->data;
+
+		if (item->added)
+			item->added(netdev, item->userdata);
+	}
+}
+
+void __netdev_watch_call_removed(struct netdev *netdev)
+{
+	const struct l_queue_entry *e;
+
+	for (e = l_queue_get_entries(netdev_watches); e; e = e->next) {
+		struct netdev_watchlist_item *item = e->data;
+
+		if (item->removed)
+			item->removed(netdev, item->userdata);
+	}
+}
+
 static void netdev_destroy(void)
 {
 	/*
@@ -225,6 +309,8 @@ bool netdev_init(void)
 		goto destroy;
 	}
 
+	netdev_watches = l_queue_new();
+
 	return true;
 
 destroy:
@@ -242,5 +328,7 @@ bool netdev_exit(void)
 
 	netdev_destroy();
 
+	l_queue_destroy(netdev_watches, netdev_watchlist_item_free);
+
 	return true;
 }
diff --git a/src/netdev.h b/src/netdev.h
index d15c8636..72c39df5 100644
--- a/src/netdev.h
+++ b/src/netdev.h
@@ -22,6 +22,11 @@
 
 #include <stdbool.h>
 
+struct netdev;
+
+typedef void (*netdev_watch_func_t)(struct netdev *netdev, void *userdata);
+typedef void (*netdev_destroy_func_t)(void *userdata);
+
 typedef void (*netdev_command_func_t) (bool result, void *user_data);
 
 enum netdev_state {
@@ -36,5 +41,13 @@ void netdev_set_linkmode_and_operstate(uint32_t ifindex,
 				uint8_t linkmode, uint8_t operstate,
 				netdev_command_func_t cb, void *user_data);
 
+uint32_t netdev_watch_add(netdev_watch_func_t added,
+				netdev_watch_func_t removed,
+				void *userdata, netdev_destroy_func_t destroy);
+bool netdev_watch_remove(uint32_t id);
+
+void __netdev_watch_call_added(struct netdev *netdev);
+void __netdev_watch_call_removed(struct netdev *netdev);
+
 bool netdev_init(void);
 bool netdev_exit(void);