[B.A.T.M.A.N.] [RFC v4 08/19] batman-adv: Add bridge_loop_avoidance mesh genl configuration

Sven Eckelmann
2019-01-19T15:56:15Z

The mesh interface can try to detect loops in the same mesh caused by
(indirectly) bridged mesh/soft-interfaces of different nodes. Some of the
loops can also be resolved without breaking the mesh.

The BATADV_CMD_SET_MESH/BATADV_CMD_GET_MESH commands allow to set/get the
configuration of this feature using the
BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED attribute. Setting the u8 to zero
will disable this feature and setting it to something else is enabling this
feature.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
Cc: Simon Wunderlich <sw@simonwunderlich.de>
---
include/uapi/linux/batman_adv.h | 7 +++++++
net/batman-adv/netlink.c | 17 +++++++++++++++++
2 files changed, 24 insertions(+)

diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index f74ff261..3cb35c66 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -381,6 +381,13 @@ enum batadv_nl_attrs {
*/
BATADV_ATTR_BONDING_ENABLED,

+ /**
+ * @BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED: whether the bridge loop
+ * avoidance feature is enabled. This feature detects and avoids loops
+ * between the mesh and devices bridged with the soft interface
+ */
+ BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED,
+
/* add attributes above here, update the policy in netlink.c */

/**
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 8a309c78..0a29dc75 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -144,6 +144,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_ISOLATION_MARK] = { .type = NLA_U32 },
[BATADV_ATTR_ISOLATION_MASK] = { .type = NLA_U32 },
[BATADV_ATTR_BONDING_ENABLED] = { .type = NLA_U8 },
+ [BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED] = { .type = NLA_U8 },
};

/**
@@ -284,6 +285,12 @@ static int batadv_netlink_mesh_put(struct sk_buff *msg,
!!atomic_read(&bat_priv->bonding)))
goto nla_put_failure;

+#ifdef CONFIG_BATMAN_ADV_BLA
+ if (nla_put_u8(msg, BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED,
+ !!atomic_read(&bat_priv->bridge_loop_avoidance)))
+ goto nla_put_failure;
+#endif /* CONFIG_BATMAN_ADV_BLA */
+
if (primary_if)
batadv_hardif_put(primary_if);

@@ -398,6 +405,16 @@ static int batadv_netlink_set_mesh(struct sk_buff *skb, struct genl_info *info)
atomic_set(&bat_priv->bonding, !!nla_get_u8(attr));
}

+#ifdef CONFIG_BATMAN_ADV_BLA
+ if (info->attrs[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED]) {
+ attr = info->attrs[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED];
+
+ atomic_set(&bat_priv->bridge_loop_avoidance,
+ !!nla_get_u8(attr));
+ batadv_bla_status_update(bat_priv->soft_iface);
+ }
+#endif /* CONFIG_BATMAN_ADV_BLA */
+
batadv_netlink_notify_mesh(bat_priv);

return 0;
--
2.20.1