From f876254b373a883499a3b15733e26c777d6f3665 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Tue, 18 Oct 2011 17:06:17 +0200
Subject: [PATCH] add interface users (similar to device users)

---
 interface.c | 27 +++++++++++++++++++++++++++
 interface.h | 11 +++++++++++
 2 files changed, 38 insertions(+)

diff --git a/interface.c b/interface.c
index 9d6a7c1..0a2afd0 100644
--- a/interface.c
+++ b/interface.c
@@ -79,6 +79,11 @@ void interface_add_error(struct interface *iface, const char *subsystem,
 static void
 interface_event(struct interface *iface, enum interface_event ev)
 {
+	struct interface_user *dep, *tmp;
+
+	list_for_each_entry_safe(dep, tmp, &iface->users, list)
+		dep->cb(dep, IFEV_UP);
+
 	interface_queue_event(iface, ev);
 }
 
@@ -168,6 +173,22 @@ interface_set_available(struct interface *iface, bool new_state)
 		__interface_set_down(iface, true);
 }
 
+void
+interface_add_user(struct interface_user *dep, struct interface *iface)
+{
+	dep->iface = iface;
+	list_add(&dep->list, &iface->users);
+	if (iface->state == IFS_UP)
+		dep->cb(dep, IFEV_UP);
+}
+
+void
+interface_remove_user(struct interface_user *dep)
+{
+	list_del_init(&dep->list);
+	dep->iface = NULL;
+}
+
 static void
 interface_claim_device(struct interface *iface)
 {
@@ -185,6 +206,11 @@ interface_claim_device(struct interface *iface)
 static void
 interface_cleanup(struct interface *iface)
 {
+	struct interface_user *dep, *tmp;
+
+	list_for_each_entry_safe(dep, tmp, &iface->users, list)
+		interface_remove_user(dep);
+
 	interface_clear_dns(iface);
 	interface_clear_errors(iface);
 	if (iface->main_dev.dev)
@@ -290,6 +316,7 @@ interface_init(struct interface *iface, const char *name,
 
 	strncpy(iface->name, name, sizeof(iface->name) - 1);
 	INIT_LIST_HEAD(&iface->errors);
+	INIT_LIST_HEAD(&iface->users);
 	INIT_LIST_HEAD(&iface->hotplug_list);
 	INIT_LIST_HEAD(&iface->proto_dns_search);
 	INIT_LIST_HEAD(&iface->proto_dns_servers);
diff --git a/interface.h b/interface.h
index 6620796..7f84060 100644
--- a/interface.h
+++ b/interface.h
@@ -33,6 +33,12 @@ struct interface_error {
 	const char *data[];
 };
 
+struct interface_user {
+	struct list_head list;
+	struct interface *iface;
+	void (*cb)(struct interface_user *dep, enum interface_event ev);
+};
+
 /*
  * interface configuration
  */
@@ -52,6 +58,8 @@ struct interface {
 	enum interface_state state;
 	enum interface_config_state config_state;
 
+	struct list_head users;
+
 	/* main interface that the interface is bound to */
 	struct device_user main_dev;
 
@@ -91,6 +99,9 @@ void interface_set_available(struct interface *iface, bool new_state);
 int interface_set_up(struct interface *iface);
 int interface_set_down(struct interface *iface);
 
+void interface_add_user(struct interface_user *dep, struct interface *iface);
+void interface_remove_user(struct interface_user *dep);
+
 int interface_add_link(struct interface *iface, struct device *llif);
 void interface_remove_link(struct interface *iface, struct device *llif);
 
-- 
2.30.2