[B.A.T.M.A.N.] [PATCH 02/11] batman-adv: Adding workqueue for new ndp packets

["Linus Lüssing" <linus.luessing@ascom.ch>]

The new neighbor discovery packets will later need their own interval
per interface. For instance on a wifi interface which has regularly
changing link qualities the ndp interval should be faster than on a
static cable link where we would need some probes from time to time
only.

This patch adds a workqueue per interface used by batman-adv. When an
interface is active, a ndp_send() with the according batman_if structure
will be called every second now.

Signed-off-by: Linus Lüssing <linus.luessing@ascom.ch>
---
 Makefile.kbuild  |    1 +
 hard-interface.c |    9 +++++++
 ndp.c            |   71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 ndp.h            |   31 +++++++++++++++++++++++
 types.h          |    3 ++
 5 files changed, 115 insertions(+), 0 deletions(-)
 create mode 100644 ndp.c
 create mode 100644 ndp.h

diff --git a/batman-adv/Makefile.kbuild b/batman-adv/Makefile.kbuild
index e99c198..094eb31 100644
--- a/batman-adv/Makefile.kbuild
+++ b/batman-adv/Makefile.kbuild
@@ -42,6 +42,7 @@ batman-adv-y += hard-interface.o
 batman-adv-y += hash.o
 batman-adv-y += icmp_socket.o
 batman-adv-y += main.o
+batman-adv-y += ndp.o
 batman-adv-y += originator.o
 batman-adv-y += ring_buffer.o
 batman-adv-y += routing.o
diff --git a/batman-adv/hard-interface.c b/batman-adv/hard-interface.c
index a992113..aba895f 100644
--- a/batman-adv/hard-interface.c
+++ b/batman-adv/hard-interface.c
@@ -26,6 +26,7 @@
 #include "translation-table.h"
 #include "routing.h"
 #include "bat_sysfs.h"
+#include "ndp.h"
 #include "originator.h"
 #include "hash.h"
 
@@ -260,6 +261,7 @@ static void hardif_activate_interface(struct batman_if *batman_if)
 		 batman_if->net_dev->name);
 
 	update_min_mtu(batman_if->soft_iface);
+	ndp_start_timer(batman_if);
 	return;
 }
 
@@ -274,6 +276,7 @@ static void hardif_deactivate_interface(struct batman_if *batman_if)
 	bat_info(batman_if->soft_iface, "Interface deactivated: %s\n",
 		 batman_if->net_dev->name);
 
+	ndp_stop_timer(batman_if);
 	update_min_mtu(batman_if->soft_iface);
 }
 
@@ -328,6 +331,8 @@ int hardif_enable_interface(struct batman_if *batman_if, char *iface_name)
 
 	atomic_set(&batman_if->seqno, 1);
 	atomic_set(&batman_if->frag_seqno, 1);
+	ndp_init(batman_if);
+
 	bat_info(batman_if->soft_iface, "Adding interface: %s\n",
 		 batman_if->net_dev->name);
 
@@ -381,6 +386,7 @@ void hardif_disable_interface(struct batman_if *batman_if)
 
 	bat_info(batman_if->soft_iface, "Removing interface: %s\n",
 		 batman_if->net_dev->name);
+	ndp_free(batman_if);
 	dev_remove_pack(&batman_if->batman_adv_ptype);
 	kref_put(&batman_if->refcount, hardif_free_ref);
 
@@ -435,6 +441,9 @@ static struct batman_if *hardif_add_interface(struct net_device *net_dev)
 	if (ret)
 		goto free_if;
 
+	atomic_set(&batman_if->ndp_interval, 500);
+	atomic_set(&batman_if->ndp_seqno, 0);
+
 	batman_if->if_num = -1;
 	batman_if->net_dev = net_dev;
 	batman_if->soft_iface = NULL;
diff --git a/batman-adv/ndp.c b/batman-adv/ndp.c
new file mode 100644
index 0000000..60631b0
--- /dev/null
+++ b/batman-adv/ndp.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2010 B.A.T.M.A.N. contributors:
+ *
+ * Linus Lüssing
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#include "main.h"
+#include "send.h"
+#include "ndp.h"
+
+/* when do we schedule our own neighbor discovery packet to be sent */
+static unsigned long own_ndp_send_time(struct batman_if *batman_if)
+{
+	return jiffies + msecs_to_jiffies(
+		   atomic_read(&batman_if->ndp_interval) -
+		   JITTER + (random32() % 2*JITTER));
+}
+
+void ndp_start_timer(struct batman_if *batman_if)
+{
+	/* adding some jitter */
+	unsigned long ndp_interval = own_ndp_send_time(batman_if);
+	queue_delayed_work(bat_event_workqueue, &batman_if->ndp_wq,
+			   ndp_interval - jiffies);
+}
+
+void ndp_stop_timer(struct batman_if *batman_if)
+{
+	cancel_delayed_work_sync(&batman_if->ndp_wq);
+}
+
+static void ndp_send(struct work_struct *work)
+{
+	struct batman_if *batman_if = container_of(work, struct batman_if,
+							ndp_wq.work);
+	struct bat_priv *bat_priv = netdev_priv(batman_if->soft_iface);
+
+	bat_dbg(DBG_BATMAN, bat_priv,
+		"batman-adv:Sending ndp packet on interface %s, seqno %d\n",
+		batman_if->net_dev, atomic_read(&batman_if->ndp_seqno));
+
+	atomic_inc(&batman_if->ndp_seqno);
+	ndp_start_timer(batman_if);
+}
+
+int ndp_init(struct batman_if *batman_if)
+{
+	INIT_DELAYED_WORK(&batman_if->ndp_wq, ndp_send);
+
+	return 0;
+}
+
+void ndp_free(struct batman_if *batman_if)
+{
+	ndp_stop_timer(batman_if);
+}
diff --git a/batman-adv/ndp.h b/batman-adv/ndp.h
new file mode 100644
index 0000000..1405e6b
--- /dev/null
+++ b/batman-adv/ndp.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2010 B.A.T.M.A.N. contributors:
+ *
+ * Linus Lüssing
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#ifndef _NET_BATMAN_ADV_NDP_H_
+#define _NET_BATMAN_ADV_NDP_H_
+
+void ndp_start_timer(struct batman_if *batman_if);
+void ndp_stop_timer(struct batman_if *batman_if);
+
+int ndp_init(struct batman_if *batman_if);
+void ndp_free(struct batman_if *batman_if);
+
+#endif /* _NET_BATMAN_ADV_NDP_H_ */
diff --git a/batman-adv/types.h b/batman-adv/types.h
index 09d18d8..3ef48a6 100644
--- a/batman-adv/types.h
+++ b/batman-adv/types.h
@@ -47,6 +47,9 @@ struct batman_if {
 	struct packet_type batman_adv_ptype;
 	struct net_device *soft_iface;
 	struct rcu_head rcu;
+	atomic_t ndp_interval;
+	atomic_t ndp_seqno;
+	struct delayed_work ndp_wq;
 };
 
 /**
-- 
1.7.1