From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Fri, 22 Aug 2014 13:52:42 +0200
Subject: batman-adv: introduce 'no_rebroadcast' option
diff --git a/batman-adv/patches/0001-batman-adv-introduce-no_rebroadcast-option.patch b/batman-adv/patches/0001-batman-adv-introduce-no_rebroadcast-option.patch
new file mode 100644
index 0000000..4f2da9a
--- /dev/null
+++ b/batman-adv/patches/0001-batman-adv-introduce-no_rebroadcast-option.patch
@@ -0,0 +1,185 @@
+From 382460a7114b734581970076d4dfe3011381e339 Mon Sep 17 00:00:00 2001
+Message-Id: <382460a7114b734581970076d4dfe3011381e339.1408708010.git.mschiffer@universe-factory.net>
+From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@web.de>
+Date: Tue, 24 Sep 2013 04:36:27 +0200
+Subject: [PATCH] batman-adv: introduce 'no_rebroadcast' option
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This patch introduces a new sysfs option named "no_rebroadcast" on
+a per hard interface basis. It allows manually enabling a split-horizon
+like behaviour for the layer 2 multicast payload frames, in that
+incoming multicast payload frames on such a hard interface are only
+being rebroadcasted on all interfaces except the incoming one instead
+of being rebroadcasted on all interfaces.
+
+Such an option should only be enabled if you are certain that these
+rebroadcasts are unnecessary. This is usually the case for instance
+for point-to-point wifi longshots or wired links.
+
+This option can especially safe a significant amount of upload overhead
+if the neighbourhood on a link is rather large, for instance in some
+transitive, symmetric VPN configurations.
+
+Using this option wrongly will break your mesh network, use this option
+wisely and at your own risk!
+
+Signed-off-by: Linus Lüssing <linus.luessing@web.de>
+---
+ hard-interface.c | 2 ++
+ send.c | 4 ++++
+ sysfs-class-net-batman-adv | 10 ++++++++
+ sysfs.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++
+ types.h | 1 +
+ 5 files changed, 76 insertions(+)
+
+diff --git a/hard-interface.c b/hard-interface.c
+index b851cc5..b222d82 100644
+--- a/hard-interface.c
++++ b/hard-interface.c
+@@ -591,6 +591,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
+ /* extra reference for return */
+ atomic_set(&hard_iface->refcount, 2);
+
++ atomic_set(&hard_iface->no_rebroadcast, 0);
++
+ batadv_check_known_mac_addr(hard_iface->net_dev);
+ list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
+
+diff --git a/send.c b/send.c
+index d27161e..4383a66 100644
+--- a/send.c
++++ b/send.c
+@@ -513,6 +513,10 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
+ if (forw_packet->num_packets >= hard_iface->num_bcasts)
+ continue;
+
++ if (atomic_read(&hard_iface->no_rebroadcast) &&
++ forw_packet->skb->dev == hard_iface->net_dev)
++ continue;
++
+ /* send a copy of the saved skb */
+ skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
+ if (skb1)
+diff --git a/sysfs-class-net-batman-adv b/sysfs-class-net-batman-adv
+index 7f34a95..cf7fe00 100644
+--- a/sysfs-class-net-batman-adv
++++ b/sysfs-class-net-batman-adv
+@@ -13,3 +13,13 @@ Description:
+ displays the batman mesh interface this <iface>
+ currently is associated with.
+
++What: /sys/class/net/<iface>/batman-adv/no_rebroadcast
++Date: Sep 2013
++Contact: Linus Lüssing <linus.luessing@web.de>
++Description:
++ With this option set incoming multicast payload frames on
++ <iface> are not being rebroadcasted on <iface> again. This
++ option should be set on links which are known to be transitive
++ and symmetric only, for instance point-to-point wifi longshots
++ or wired links. Using this option wrongly is going to
++ break your mesh network, use at your own risk!
+diff --git a/sysfs.c b/sysfs.c
+index 1ebb0d9..780c52e 100644
+--- a/sysfs.c
++++ b/sysfs.c
+@@ -108,6 +108,17 @@ struct batadv_attribute batadv_attr_vlan_##_name = { \
+ .store = _store, \
+ };
+
++/* Use this, if you have customized show and store functions
++ * for hard interface attrs
++ */
++#define BATADV_ATTR_HIF(_name, _mode, _show, _store) \
++struct batadv_attribute batadv_attr_hif_##_name = { \
++ .attr = {.name = __stringify(_name), \
++ .mode = _mode }, \
++ .show = _show, \
++ .store = _store, \
++};
++
+ /* Use this, if you have customized show and store functions */
+ #define BATADV_ATTR(_name, _mode, _show, _store) \
+ struct batadv_attribute batadv_attr_##_name = { \
+@@ -213,6 +224,52 @@ ssize_t batadv_show_vlan_##_name(struct kobject *kobj, \
+ static BATADV_ATTR_VLAN(_name, _mode, batadv_show_vlan_##_name, \
+ batadv_store_vlan_##_name)
+
++#define BATADV_ATTR_HIF_STORE_BOOL(_name, _post_func) \
++ssize_t batadv_store_hif_##_name(struct kobject *kobj, \
++ struct attribute *attr, char *buff, \
++ size_t count) \
++{ \
++ struct net_device *net_dev = batadv_kobj_to_netdev(kobj); \
++ struct batadv_hard_iface *hard_iface; \
++ size_t res; \
++ \
++ hard_iface = batadv_hardif_get_by_netdev(net_dev); \
++ if (!hard_iface) \
++ return 0; \
++ \
++ res = __batadv_store_bool_attr(buff, count, _post_func, \
++ attr, &hard_iface->_name, \
++ hard_iface->soft_iface); \
++ batadv_hardif_free_ref(hard_iface); \
++ return res; \
++}
++
++#define BATADV_ATTR_HIF_SHOW_BOOL(_name) \
++ssize_t batadv_show_hif_##_name(struct kobject *kobj, \
++ struct attribute *attr, char *buff) \
++{ \
++ struct net_device *net_dev = batadv_kobj_to_netdev(kobj); \
++ struct batadv_hard_iface *hard_iface; \
++ size_t res; \
++ \
++ hard_iface = batadv_hardif_get_by_netdev(net_dev); \
++ if (!hard_iface) \
++ return 0; \
++ \
++ res = sprintf(buff, "%s\n", \
++ atomic_read(&hard_iface->_name) == 0 ? \
++ "disabled" : "enabled"); \
++ batadv_hardif_free_ref(hard_iface); \
++ return res; \
++}
++
++/* Use this, if you are going to turn a [name] in the vlan struct on or off */
++#define BATADV_ATTR_HIF_BOOL(_name, _mode, _post_func) \
++ static BATADV_ATTR_HIF_STORE_BOOL(_name, _post_func) \
++ static BATADV_ATTR_HIF_SHOW_BOOL(_name) \
++ static BATADV_ATTR_HIF(_name, _mode, batadv_show_hif_##_name, \
++ batadv_store_hif_##_name)
++
+ static int batadv_store_bool_attr(char *buff, size_t count,
+ struct net_device *net_dev,
+ const char *attr_name, atomic_t *attr)
+@@ -834,10 +891,12 @@ static ssize_t batadv_show_iface_status(struct kobject *kobj,
+ static BATADV_ATTR(mesh_iface, S_IRUGO | S_IWUSR, batadv_show_mesh_iface,
+ batadv_store_mesh_iface);
+ static BATADV_ATTR(iface_status, S_IRUGO, batadv_show_iface_status, NULL);
++BATADV_ATTR_HIF_BOOL(no_rebroadcast, S_IRUGO | S_IWUSR, NULL);
+
+ static struct batadv_attribute *batadv_batman_attrs[] = {
+ &batadv_attr_mesh_iface,
+ &batadv_attr_iface_status,
++ &batadv_attr_hif_no_rebroadcast,
+ NULL,
+ };
+
+diff --git a/types.h b/types.h
+index 8854c05..39619fb 100644
+--- a/types.h
++++ b/types.h
+@@ -101,6 +101,7 @@ struct batadv_hard_iface {
+ struct batadv_hard_iface_bat_iv bat_iv;
+ struct work_struct cleanup_work;
+ struct dentry *debug_dir;
++ atomic_t no_rebroadcast;
+ };
+
+ /**
+--
+2.1.0
+