[PATCH 0/2] pull request for net: batman-adv 2017-03-16

[PATCH 0/2] pull request for net: batman-adv 2017-03-16

[Simon Wunderlich]

Hi David,

here are two bugfixes for batman-adv which we would like to see integrated into net.

Please pull or let me know of any problem!

Thank you,
      Simon

The following changes since commit 51c6b429c0c95e67edd1cb0b548c5cf6a6604763:

  batman-adv: Fix transmission of final, 16th fragment (2017-02-21 18:33:35 +0100)

are available in the git repository at:

  git://git.open-mesh.org/linux-merge.git tags/batadv-net-for-davem-20170316

for you to fetch changes up to 1a9070ec91b37234fe915849b767c61584c64a44:

  batman-adv: Initialize gw sel_class via batadv_algo (2017-03-04 17:32:06 +0100)

----------------------------------------------------------------
Here are two batman-adv bugfixes:

 - Keep fragments equally sized, avoids some problems with too small fragments,
   by Sven Eckelmann

 - Initialize gateway class correctly when BATMAN V is compiled in,
   by Sven Eckelmann

----------------------------------------------------------------
Sven Eckelmann (2):
      batman-adv: Keep fragments equally sized
      batman-adv: Initialize gw sel_class via batadv_algo

 net/batman-adv/bat_iv_ogm.c     | 11 +++++++++++
 net/batman-adv/bat_v.c          | 14 +++++++++++---
 net/batman-adv/fragmentation.c  | 20 +++++++++++++-------
 net/batman-adv/gateway_common.c |  5 +++++
 net/batman-adv/soft-interface.c |  1 -
 net/batman-adv/types.h          |  2 ++
 6 files changed, 42 insertions(+), 11 deletions(-)

[B.A.T.M.A.N.] [PATCH 0/2] pull request for net: batman-adv 2017-03-16

[Simon Wunderlich]

Hi David,

here are two bugfixes for batman-adv which we would like to see integrated into net.

Please pull or let me know of any problem!

Thank you,
      Simon

The following changes since commit 51c6b429c0c95e67edd1cb0b548c5cf6a6604763:

  batman-adv: Fix transmission of final, 16th fragment (2017-02-21 18:33:35 +0100)

are available in the git repository at:

  git://git.open-mesh.org/linux-merge.git tags/batadv-net-for-davem-20170316

for you to fetch changes up to 1a9070ec91b37234fe915849b767c61584c64a44:

  batman-adv: Initialize gw sel_class via batadv_algo (2017-03-04 17:32:06 +0100)

----------------------------------------------------------------
Here are two batman-adv bugfixes:

 - Keep fragments equally sized, avoids some problems with too small fragments,
   by Sven Eckelmann

 - Initialize gateway class correctly when BATMAN V is compiled in,
   by Sven Eckelmann

----------------------------------------------------------------
Sven Eckelmann (2):
      batman-adv: Keep fragments equally sized
      batman-adv: Initialize gw sel_class via batadv_algo

 net/batman-adv/bat_iv_ogm.c     | 11 +++++++++++
 net/batman-adv/bat_v.c          | 14 +++++++++++---
 net/batman-adv/fragmentation.c  | 20 +++++++++++++-------
 net/batman-adv/gateway_common.c |  5 +++++
 net/batman-adv/soft-interface.c |  1 -
 net/batman-adv/types.h          |  2 ++
 6 files changed, 42 insertions(+), 11 deletions(-)

[PATCH 1/2] batman-adv: Keep fragments equally sized

[Simon Wunderlich]

From: Sven Eckelmann <sven-KaDOiPu9UxWEi8DpZVb4nw@public.gmane.org>

The batman-adv fragmentation packets have the design problem that they
cannot be refragmented and cannot handle padding by the underlying link.
The latter often leads to problems when networks are incorrectly configured
and don't use a common MTU.

The sender could for example fragment a 1271 byte frame (plus external
ethernet header (14) and batadv unicast header (10)) to fit in a 1280 bytes
large MTU of the underlying link (max. 1294 byte frames). This would create
a 1294 bytes large frame (fragment 2) and a 55 bytes large frame
(fragment 1). The extra 54 bytes are the fragment header (20) added to each
fragment and the external ethernet header (14) for the second fragment.

Let us assume that the next hop is then not able to transport 1294 bytes to
its next hop. The 1294 byte large frame will be dropped but the 55 bytes
large fragment will still be forwarded to its destination.

Or let us assume that the underlying hardware requires that each frame has
a minimum size (e.g. 60 bytes). Then it will pad the 55 bytes frame to 60
bytes. The receiver of the 60 bytes frame will no longer be able to
correctly assemble the two frames together because it is not aware that 5
bytes of the 60 bytes frame are padding and don't belong to the reassembled
frame.

This can partly be avoided by splitting frames more equally. In this
example, the 675 and 674 bytes large fragment frames could both potentially
reach its destination without being too large or too small.

Reported-by: Martin Weinelt <martin-VjL1Zewfs7ir2odhgoY7gCae+QG6wtwz@public.gmane.org>
Fixes: ee75ed88879a ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven-KaDOiPu9UxWEi8DpZVb4nw@public.gmane.org>
Acked-by: Linus Lüssing <linus.luessing-djzkFPsfvsizQB+pC5nmwQ@public.gmane.org>
Signed-off-by: Simon Wunderlich <sw-2YrNx6rUIHYiY0qSoAWiAoQuADTiUCJX@public.gmane.org>
---
 net/batman-adv/fragmentation.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index 11149e5be4e0..106bda56ec98 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -404,7 +404,7 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb,
  * batadv_frag_create - create a fragment from skb
  * @skb: skb to create fragment from
  * @frag_head: header to use in new fragment
- * @mtu: size of new fragment
+ * @fragment_size: size of new fragment
  *
  * Split the passed skb into two fragments: A new one with size matching the
  * passed mtu and the old one with the rest. The new skb contains data from the
@@ -414,11 +414,11 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb,
  */
 static struct sk_buff *batadv_frag_create(struct sk_buff *skb,
 					  struct batadv_frag_packet *frag_head,
-					  unsigned int mtu)
+					  unsigned int fragment_size)
 {
 	struct sk_buff *skb_fragment;
 	unsigned int header_size = sizeof(*frag_head);
-	unsigned int fragment_size = mtu - header_size;
+	unsigned int mtu = fragment_size + header_size;
 
 	skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN);
 	if (!skb_fragment)
@@ -456,7 +456,7 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 	struct sk_buff *skb_fragment;
 	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;
 	unsigned int header_size = sizeof(frag_header);
-	unsigned int max_fragment_size, max_packet_size;
+	unsigned int max_fragment_size, num_fragments;
 	int ret;
 
 	/* To avoid merge and refragmentation at next-hops we never send
@@ -464,10 +464,15 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 	 */
 	mtu = min_t(unsigned int, mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 	max_fragment_size = mtu - header_size;
-	max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS;
+
+	if (skb->len == 0 || max_fragment_size == 0)
+		return -EINVAL;
+
+	num_fragments = (skb->len - 1) / max_fragment_size + 1;
+	max_fragment_size = (skb->len - 1) / num_fragments + 1;
 
 	/* Don't even try to fragment, if we need more than 16 fragments */
-	if (skb->len > max_packet_size) {
+	if (num_fragments > BATADV_FRAG_MAX_FRAGMENTS) {
 		ret = -EAGAIN;
 		goto free_skb;
 	}
@@ -507,7 +512,8 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 			goto put_primary_if;
 		}
 
-		skb_fragment = batadv_frag_create(skb, &frag_header, mtu);
+		skb_fragment = batadv_frag_create(skb, &frag_header,
+						  max_fragment_size);
 		if (!skb_fragment) {
 			ret = -ENOMEM;
 			goto put_primary_if;
-- 
2.11.0

[B.A.T.M.A.N.] [PATCH 1/2] batman-adv: Keep fragments equally sized

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

The batman-adv fragmentation packets have the design problem that they
cannot be refragmented and cannot handle padding by the underlying link.
The latter often leads to problems when networks are incorrectly configured
and don't use a common MTU.

The sender could for example fragment a 1271 byte frame (plus external
ethernet header (14) and batadv unicast header (10)) to fit in a 1280 bytes
large MTU of the underlying link (max. 1294 byte frames). This would create
a 1294 bytes large frame (fragment 2) and a 55 bytes large frame
(fragment 1). The extra 54 bytes are the fragment header (20) added to each
fragment and the external ethernet header (14) for the second fragment.

Let us assume that the next hop is then not able to transport 1294 bytes to
its next hop. The 1294 byte large frame will be dropped but the 55 bytes
large fragment will still be forwarded to its destination.

Or let us assume that the underlying hardware requires that each frame has
a minimum size (e.g. 60 bytes). Then it will pad the 55 bytes frame to 60
bytes. The receiver of the 60 bytes frame will no longer be able to
correctly assemble the two frames together because it is not aware that 5
bytes of the 60 bytes frame are padding and don't belong to the reassembled
frame.

This can partly be avoided by splitting frames more equally. In this
example, the 675 and 674 bytes large fragment frames could both potentially
reach its destination without being too large or too small.

Reported-by: Martin Weinelt <martin@darmstadt.freifunk.net>
Fixes: ee75ed88879a ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/fragmentation.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index 11149e5be4e0..106bda56ec98 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -404,7 +404,7 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb,
  * batadv_frag_create - create a fragment from skb
  * @skb: skb to create fragment from
  * @frag_head: header to use in new fragment
- * @mtu: size of new fragment
+ * @fragment_size: size of new fragment
  *
  * Split the passed skb into two fragments: A new one with size matching the
  * passed mtu and the old one with the rest. The new skb contains data from the
@@ -414,11 +414,11 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb,
  */
 static struct sk_buff *batadv_frag_create(struct sk_buff *skb,
 					  struct batadv_frag_packet *frag_head,
-					  unsigned int mtu)
+					  unsigned int fragment_size)
 {
 	struct sk_buff *skb_fragment;
 	unsigned int header_size = sizeof(*frag_head);
-	unsigned int fragment_size = mtu - header_size;
+	unsigned int mtu = fragment_size + header_size;
 
 	skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN);
 	if (!skb_fragment)
@@ -456,7 +456,7 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 	struct sk_buff *skb_fragment;
 	unsigned int mtu = neigh_node->if_incoming->net_dev->mtu;
 	unsigned int header_size = sizeof(frag_header);
-	unsigned int max_fragment_size, max_packet_size;
+	unsigned int max_fragment_size, num_fragments;
 	int ret;
 
 	/* To avoid merge and refragmentation at next-hops we never send
@@ -464,10 +464,15 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 	 */
 	mtu = min_t(unsigned int, mtu, BATADV_FRAG_MAX_FRAG_SIZE);
 	max_fragment_size = mtu - header_size;
-	max_packet_size = max_fragment_size * BATADV_FRAG_MAX_FRAGMENTS;
+
+	if (skb->len == 0 || max_fragment_size == 0)
+		return -EINVAL;
+
+	num_fragments = (skb->len - 1) / max_fragment_size + 1;
+	max_fragment_size = (skb->len - 1) / num_fragments + 1;
 
 	/* Don't even try to fragment, if we need more than 16 fragments */
-	if (skb->len > max_packet_size) {
+	if (num_fragments > BATADV_FRAG_MAX_FRAGMENTS) {
 		ret = -EAGAIN;
 		goto free_skb;
 	}
@@ -507,7 +512,8 @@ int batadv_frag_send_packet(struct sk_buff *skb,
 			goto put_primary_if;
 		}
 
-		skb_fragment = batadv_frag_create(skb, &frag_header, mtu);
+		skb_fragment = batadv_frag_create(skb, &frag_header,
+						  max_fragment_size);
 		if (!skb_fragment) {
 			ret = -ENOMEM;
 			goto put_primary_if;
-- 
2.11.0

[PATCH 2/2] batman-adv: Initialize gw sel_class via batadv_algo

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

The gateway selection class variable is shared between different algorithm
versions. But the interpretation of the content is algorithm specific. The
initialization is therefore also algorithm specific.

But this was implemented incorrectly and the initialization for BATMAN_V
always overwrote the value previously written for BATMAN_IV. This could
only be avoided when BATMAN_V was disabled during compile time.

Using a special batadv_algo hook for this initialization avoids this
problem.

Fixes: 50164d8f500f ("batman-adv: B.A.T.M.A.N. V - implement GW selection logic")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/bat_iv_ogm.c     | 11 +++++++++++
 net/batman-adv/bat_v.c          | 14 +++++++++++---
 net/batman-adv/gateway_common.c |  5 +++++
 net/batman-adv/soft-interface.c |  1 -
 net/batman-adv/types.h          |  2 ++
 5 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index f00f666e2ccd..7bfd0d7ef49d 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -2477,6 +2477,16 @@ static void batadv_iv_iface_activate(struct batadv_hard_iface *hard_iface)
 	batadv_iv_ogm_schedule(hard_iface);
 }
 
+/**
+ * batadv_iv_init_sel_class - initialize GW selection class
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_iv_init_sel_class(struct batadv_priv *bat_priv)
+{
+	/* set default TQ difference threshold to 20 */
+	atomic_set(&bat_priv->gw.sel_class, 20);
+}
+
 static struct batadv_gw_node *
 batadv_iv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 {
@@ -2823,6 +2833,7 @@ static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
 		.del_if = batadv_iv_ogm_orig_del_if,
 	},
 	.gw = {
+		.init_sel_class = batadv_iv_init_sel_class,
 		.get_best_gw_node = batadv_iv_gw_get_best_gw_node,
 		.is_eligible = batadv_iv_gw_is_eligible,
 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index 2ac612d7bab4..2e2471ca84e3 100644
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -668,6 +668,16 @@ static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
 	return ret;
 }
 
+/**
+ * batadv_v_init_sel_class - initialize GW selection class
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_v_init_sel_class(struct batadv_priv *bat_priv)
+{
+	/* set default throughput difference threshold to 5Mbps */
+	atomic_set(&bat_priv->gw.sel_class, 50);
+}
+
 static ssize_t batadv_v_store_sel_class(struct batadv_priv *bat_priv,
 					char *buff, size_t count)
 {
@@ -1052,6 +1062,7 @@ static struct batadv_algo_ops batadv_batman_v __read_mostly = {
 		.dump = batadv_v_orig_dump,
 	},
 	.gw = {
+		.init_sel_class = batadv_v_init_sel_class,
 		.store_sel_class = batadv_v_store_sel_class,
 		.show_sel_class = batadv_v_show_sel_class,
 		.get_best_gw_node = batadv_v_gw_get_best_gw_node,
@@ -1092,9 +1103,6 @@ int batadv_v_mesh_init(struct batadv_priv *bat_priv)
 	if (ret < 0)
 		return ret;
 
-	/* set default throughput difference threshold to 5Mbps */
-	atomic_set(&bat_priv->gw.sel_class, 50);
-
 	return 0;
 }
 
diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
index 21184810d89f..3e3f91ab694f 100644
--- a/net/batman-adv/gateway_common.c
+++ b/net/batman-adv/gateway_common.c
@@ -253,6 +253,11 @@ static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
  */
 void batadv_gw_init(struct batadv_priv *bat_priv)
 {
+	if (bat_priv->algo_ops->gw.init_sel_class)
+		bat_priv->algo_ops->gw.init_sel_class(bat_priv);
+	else
+		atomic_set(&bat_priv->gw.sel_class, 1);
+
 	batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 				     NULL, BATADV_TVLV_GW, 1,
 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 7b3494ae6ad9..2e0b3463ab4a 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -820,7 +820,6 @@ static int batadv_softif_init_late(struct net_device *dev)
 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
 #endif
 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
-	atomic_set(&bat_priv->gw.sel_class, 20);
 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
 	atomic_set(&bat_priv->orig_interval, 1000);
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index e913aee28c98..5137d859694c 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1489,6 +1489,7 @@ struct batadv_algo_orig_ops {
 
 /**
  * struct batadv_algo_gw_ops - mesh algorithm callbacks (GW specific)
+ * @init_sel_class: initialize GW selection class (optional)
  * @store_sel_class: parse and stores a new GW selection class (optional)
  * @show_sel_class: prints the current GW selection class (optional)
  * @get_best_gw_node: select the best GW from the list of available nodes
@@ -1499,6 +1500,7 @@ struct batadv_algo_orig_ops {
  * @dump: dump gateways to a netlink socket (optional)
  */
 struct batadv_algo_gw_ops {
+	void (*init_sel_class)(struct batadv_priv *bat_priv);
 	ssize_t (*store_sel_class)(struct batadv_priv *bat_priv, char *buff,
 				   size_t count);
 	ssize_t (*show_sel_class)(struct batadv_priv *bat_priv, char *buff);
-- 
2.11.0

[B.A.T.M.A.N.] [PATCH 2/2] batman-adv: Initialize gw sel_class via batadv_algo

[Simon Wunderlich]

From: Sven Eckelmann <sven@narfation.org>

The gateway selection class variable is shared between different algorithm
versions. But the interpretation of the content is algorithm specific. The
initialization is therefore also algorithm specific.

But this was implemented incorrectly and the initialization for BATMAN_V
always overwrote the value previously written for BATMAN_IV. This could
only be avoided when BATMAN_V was disabled during compile time.

Using a special batadv_algo hook for this initialization avoids this
problem.

Fixes: 50164d8f500f ("batman-adv: B.A.T.M.A.N. V - implement GW selection logic")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/bat_iv_ogm.c     | 11 +++++++++++
 net/batman-adv/bat_v.c          | 14 +++++++++++---
 net/batman-adv/gateway_common.c |  5 +++++
 net/batman-adv/soft-interface.c |  1 -
 net/batman-adv/types.h          |  2 ++
 5 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index f00f666e2ccd..7bfd0d7ef49d 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -2477,6 +2477,16 @@ static void batadv_iv_iface_activate(struct batadv_hard_iface *hard_iface)
 	batadv_iv_ogm_schedule(hard_iface);
 }
 
+/**
+ * batadv_iv_init_sel_class - initialize GW selection class
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_iv_init_sel_class(struct batadv_priv *bat_priv)
+{
+	/* set default TQ difference threshold to 20 */
+	atomic_set(&bat_priv->gw.sel_class, 20);
+}
+
 static struct batadv_gw_node *
 batadv_iv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
 {
@@ -2823,6 +2833,7 @@ static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
 		.del_if = batadv_iv_ogm_orig_del_if,
 	},
 	.gw = {
+		.init_sel_class = batadv_iv_init_sel_class,
 		.get_best_gw_node = batadv_iv_gw_get_best_gw_node,
 		.is_eligible = batadv_iv_gw_is_eligible,
 #ifdef CONFIG_BATMAN_ADV_DEBUGFS
diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c
index 2ac612d7bab4..2e2471ca84e3 100644
--- a/net/batman-adv/bat_v.c
+++ b/net/batman-adv/bat_v.c
@@ -668,6 +668,16 @@ static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
 	return ret;
 }
 
+/**
+ * batadv_v_init_sel_class - initialize GW selection class
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_v_init_sel_class(struct batadv_priv *bat_priv)
+{
+	/* set default throughput difference threshold to 5Mbps */
+	atomic_set(&bat_priv->gw.sel_class, 50);
+}
+
 static ssize_t batadv_v_store_sel_class(struct batadv_priv *bat_priv,
 					char *buff, size_t count)
 {
@@ -1052,6 +1062,7 @@ static struct batadv_algo_ops batadv_batman_v __read_mostly = {
 		.dump = batadv_v_orig_dump,
 	},
 	.gw = {
+		.init_sel_class = batadv_v_init_sel_class,
 		.store_sel_class = batadv_v_store_sel_class,
 		.show_sel_class = batadv_v_show_sel_class,
 		.get_best_gw_node = batadv_v_gw_get_best_gw_node,
@@ -1092,9 +1103,6 @@ int batadv_v_mesh_init(struct batadv_priv *bat_priv)
 	if (ret < 0)
 		return ret;
 
-	/* set default throughput difference threshold to 5Mbps */
-	atomic_set(&bat_priv->gw.sel_class, 50);
-
 	return 0;
 }
 
diff --git a/net/batman-adv/gateway_common.c b/net/batman-adv/gateway_common.c
index 21184810d89f..3e3f91ab694f 100644
--- a/net/batman-adv/gateway_common.c
+++ b/net/batman-adv/gateway_common.c
@@ -253,6 +253,11 @@ static void batadv_gw_tvlv_ogm_handler_v1(struct batadv_priv *bat_priv,
  */
 void batadv_gw_init(struct batadv_priv *bat_priv)
 {
+	if (bat_priv->algo_ops->gw.init_sel_class)
+		bat_priv->algo_ops->gw.init_sel_class(bat_priv);
+	else
+		atomic_set(&bat_priv->gw.sel_class, 1);
+
 	batadv_tvlv_handler_register(bat_priv, batadv_gw_tvlv_ogm_handler_v1,
 				     NULL, BATADV_TVLV_GW, 1,
 				     BATADV_TVLV_HANDLER_OGM_CIFNOTFND);
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 7b3494ae6ad9..2e0b3463ab4a 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -820,7 +820,6 @@ static int batadv_softif_init_late(struct net_device *dev)
 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
 #endif
 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
-	atomic_set(&bat_priv->gw.sel_class, 20);
 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
 	atomic_set(&bat_priv->orig_interval, 1000);
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index e913aee28c98..5137d859694c 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -1489,6 +1489,7 @@ struct batadv_algo_orig_ops {
 
 /**
  * struct batadv_algo_gw_ops - mesh algorithm callbacks (GW specific)
+ * @init_sel_class: initialize GW selection class (optional)
  * @store_sel_class: parse and stores a new GW selection class (optional)
  * @show_sel_class: prints the current GW selection class (optional)
  * @get_best_gw_node: select the best GW from the list of available nodes
@@ -1499,6 +1500,7 @@ struct batadv_algo_orig_ops {
  * @dump: dump gateways to a netlink socket (optional)
  */
 struct batadv_algo_gw_ops {
+	void (*init_sel_class)(struct batadv_priv *bat_priv);
 	ssize_t (*store_sel_class)(struct batadv_priv *bat_priv, char *buff,
 				   size_t count);
 	ssize_t (*show_sel_class)(struct batadv_priv *bat_priv, char *buff);
-- 
2.11.0

Re: [PATCH 0/2] pull request for net: batman-adv 2017-03-16

[David Miller]

From: Simon Wunderlich <sw@simonwunderlich.de>
Date: Thu, 16 Mar 2017 13:55:10 +0100

> here are two bugfixes for batman-adv which we would like to see
> integrated into net.
> 
> Please pull or let me know of any problem!

Pulled, thanks Simon.

Re: [B.A.T.M.A.N.] [PATCH 0/2] pull request for net: batman-adv 2017-03-16

[David Miller]

From: Simon Wunderlich <sw@simonwunderlich.de>
Date: Thu, 16 Mar 2017 13:55:10 +0100

> here are two bugfixes for batman-adv which we would like to see
> integrated into net.
> 
> Please pull or let me know of any problem!

Pulled, thanks Simon.