batman-adv: add generic netlink family for batman-adv

debugfs is currently severely broken virtually everywhere in the kernel
where files are dynamically added and removed (see
http://lkml.iu.edu/hypermail/linux/kernel/1506.1/02196.html for some
details). In addition to that, debugfs is not namespace-aware.

Instead of adding new debugfs entries, the whole infrastructure should be
moved to netlink. This will fix the long standing problem of large buffers
for debug tables and hard to parse text files.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
[sven.eckelmann@open-mesh.com: Strip down patch to only add genl family,
add missing kerneldoc]
Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

4 files changed, 87 insertions, 0 deletions

diff --git a/net/batman-adv/Makefile b/net/batman-adv/Makefile
index a55f4ec97068..7da59014e134 100644
--- a/net/batman-adv/Makefile
+++ b/net/batman-adv/Makefile
@@ -35,6 +35,7 @@ batman-adv-y += icmp_socket.o
 batman-adv-$(CONFIG_BATMAN_ADV_DEBUG) += log.o
 batman-adv-y += main.o
 batman-adv-$(CONFIG_BATMAN_ADV_MCAST) += multicast.o
+batman-adv-y += netlink.o
 batman-adv-$(CONFIG_BATMAN_ADV_NC) += network-coding.o
 batman-adv-y += originator.o
 batman-adv-y += routing.o
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index eab9d1b8a6eb..275604b7c64e 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -57,6 +57,7 @@
 #include "icmp_socket.h"
 #include "log.h"
 #include "multicast.h"
+#include "netlink.h"
 #include "network-coding.h"
 #include "originator.h"
 #include "packet.h"
@@ -99,6 +100,7 @@ static int __init batadv_init(void)
 
 	register_netdevice_notifier(&batadv_hard_if_notifier);
 	rtnl_link_register(&batadv_link_ops);
+	batadv_netlink_register();
 
 	pr_info("B.A.T.M.A.N. advanced %s (compatibility version %i) loaded\n",
 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
@@ -109,6 +111,7 @@ static int __init batadv_init(void)
 static void __exit batadv_exit(void)
 {
 	batadv_debugfs_destroy();
+	batadv_netlink_unregister();
 	rtnl_link_unregister(&batadv_link_ops);
 	unregister_netdevice_notifier(&batadv_hard_if_notifier);
 	batadv_hardif_remove_interfaces();
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
new file mode 100644
index 000000000000..9e4c865a9cc0
--- /dev/null
+++ b/net/batman-adv/netlink.c
@@ -0,0 +1,57 @@
+/* Copyright (C) 2016 B.A.T.M.A.N. contributors:
+ *
+ * Matthias Schiffer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "netlink.h"
+#include "main.h"
+
+#include <linux/genetlink.h>
+#include <linux/init.h>
+#include <linux/printk.h>
+#include <net/genetlink.h>
+#include <uapi/linux/batman_adv.h>
+
+static struct genl_family batadv_netlink_family = {
+	.id = GENL_ID_GENERATE,
+	.hdrsize = 0,
+	.name = BATADV_NL_NAME,
+	.version = 1,
+	.maxattr = BATADV_ATTR_MAX,
+};
+
+static struct genl_ops batadv_netlink_ops[] = {
+};
+
+/**
+ * batadv_netlink_register - register batadv genl netlink family
+ */
+void __init batadv_netlink_register(void)
+{
+	int ret;
+
+	ret = genl_register_family_with_ops(&batadv_netlink_family,
+					    batadv_netlink_ops);
+	if (ret)
+		pr_warn("unable to register netlink family");
+}
+
+/**
+ * batadv_netlink_unregister - unregister batadv genl netlink family
+ */
+void batadv_netlink_unregister(void)
+{
+	genl_unregister_family(&batadv_netlink_family);
+}
diff --git a/net/batman-adv/netlink.h b/net/batman-adv/netlink.h
new file mode 100644
index 000000000000..39044ccff662
--- /dev/null
+++ b/net/batman-adv/netlink.h
@@ -0,0 +1,26 @@
+/* Copyright (C) 2016 B.A.T.M.A.N. contributors:
+ *
+ * Matthias Schiffer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _NET_BATMAN_ADV_NETLINK_H_
+#define _NET_BATMAN_ADV_NETLINK_H_
+
+#include "main.h"
+
+void batadv_netlink_register(void);
+void batadv_netlink_unregister(void);
+
+#endif /* _NET_BATMAN_ADV_NETLINK_H_ */