ipvs: generalize app registration in netns

Get rid of the ftp_app pointer and allow applications
to be registered without adding fields in the netns_ipvs structure.

v2: fix coding style as suggested by Pablo Neira Ayuso <[e-mail]>

Signed-off-by: Julian Anastasov <[e-mail]>
Signed-off-by: Simon Horman <[e-mail]>

include/net/ip_vs.h

···
 	struct list_head	rs_table[IP_VS_RTAB_SIZE];
 	/* ip_vs_app */
 	struct list_head	app_list;
-	/* ip_vs_ftp */
-	struct ip_vs_app	*ftp_app;
 	/* ip_vs_proto */
 	#define IP_VS_PROTO_TAB_SIZE	32	/* must be power of 2 */
 	struct ip_vs_proto_data *proto_data_table[IP_VS_PROTO_TAB_SIZE];
···
  *      (from ip_vs_app.c)
  */
 #define IP_VS_APP_MAX_PORTS  8
-extern int register_ip_vs_app(struct net *net, struct ip_vs_app *app);
+extern struct ip_vs_app *register_ip_vs_app(struct net *net,
+					    struct ip_vs_app *app);
 extern void unregister_ip_vs_app(struct net *net, struct ip_vs_app *app);
 extern int ip_vs_bind_app(struct ip_vs_conn *cp, struct ip_vs_protocol *pp);
 extern void ip_vs_unbind_app(struct ip_vs_conn *cp);

net/netfilter/ipvs/ip_vs_app.c

···
 }
 
 
-/*
- *	ip_vs_app registration routine
- */
-int register_ip_vs_app(struct net *net, struct ip_vs_app *app)
+/* Register application for netns */
+struct ip_vs_app *register_ip_vs_app(struct net *net, struct ip_vs_app *app)
 {
 	struct netns_ipvs *ipvs = net_ipvs(net);
-	/* increase the module use count */
-	ip_vs_use_count_inc();
+	struct ip_vs_app *a;
+	int err = 0;
+
+	if (!ipvs)
+		return ERR_PTR(-ENOENT);
 
 	mutex_lock(&__ip_vs_app_mutex);
 
-	list_add(&app->a_list, &ipvs->app_list);
+	list_for_each_entry(a, &ipvs->app_list, a_list) {
+		if (!strcmp(app->name, a->name)) {
+			err = -EEXIST;
+			goto out_unlock;
+		}
+	}
+	a = kmemdup(app, sizeof(*app), GFP_KERNEL);
+	if (!a) {
+		err = -ENOMEM;
+		goto out_unlock;
+	}
+	INIT_LIST_HEAD(&a->incs_list);
+	list_add(&a->a_list, &ipvs->app_list);
+	/* increase the module use count */
+	ip_vs_use_count_inc();
 
+out_unlock:
 	mutex_unlock(&__ip_vs_app_mutex);
 
-	return 0;
+	return err ? ERR_PTR(err) : a;
 }
 
 
···
  */
 void unregister_ip_vs_app(struct net *net, struct ip_vs_app *app)
 {
-	struct ip_vs_app *inc, *nxt;
+	struct netns_ipvs *ipvs = net_ipvs(net);
+	struct ip_vs_app *a, *anxt, *inc, *nxt;
+
+	if (!ipvs)
+		return;
 
 	mutex_lock(&__ip_vs_app_mutex);
 
-	list_for_each_entry_safe(inc, nxt, &app->incs_list, a_list) {
-		ip_vs_app_inc_release(net, inc);
+	list_for_each_entry_safe(a, anxt, &ipvs->app_list, a_list) {
+		if (app && strcmp(app->name, a->name))
+			continue;
+		list_for_each_entry_safe(inc, nxt, &a->incs_list, a_list) {
+			ip_vs_app_inc_release(net, inc);
+		}
+
+		list_del(&a->a_list);
+		kfree(a);
+
+		/* decrease the module use count */
+		ip_vs_use_count_dec();
 	}
 
-	list_del(&app->a_list);
-
 	mutex_unlock(&__ip_vs_app_mutex);
-
-	/* decrease the module use count */
-	ip_vs_use_count_dec();
 }
 
 
···
 
 void __net_exit ip_vs_app_net_cleanup(struct net *net)
 {
+	unregister_ip_vs_app(net, NULL /* all */);
 	proc_net_remove(net, "ip_vs_app");
 }

net/netfilter/ipvs/ip_vs_ftp.c

···
 
 	if (!ipvs)
 		return -ENOENT;
-	app = kmemdup(&ip_vs_ftp, sizeof(struct ip_vs_app), GFP_KERNEL);
-	if (!app)
-		return -ENOMEM;
-	INIT_LIST_HEAD(&app->a_list);
-	INIT_LIST_HEAD(&app->incs_list);
-	ipvs->ftp_app = app;
 
-	ret = register_ip_vs_app(net, app);
-	if (ret)
-		goto err_exit;
+	app = register_ip_vs_app(net, &ip_vs_ftp);
+	if (IS_ERR(app))
+		return PTR_ERR(app);
 
 	for (i = 0; i < ports_count; i++) {
 		if (!ports[i])
···
 	return 0;
 
 err_unreg:
-	unregister_ip_vs_app(net, app);
-err_exit:
-	kfree(ipvs->ftp_app);
+	unregister_ip_vs_app(net, &ip_vs_ftp);
 	return ret;
 }
 /*
···
  */
 static void __ip_vs_ftp_exit(struct net *net)
 {
-	struct netns_ipvs *ipvs = net_ipvs(net);
-
-	unregister_ip_vs_app(net, ipvs->ftp_app);
-	kfree(ipvs->ftp_app);
+	unregister_ip_vs_app(net, &ip_vs_ftp);
 }
 
 static struct pernet_operations ip_vs_ftp_ops = {