[B.A.T.M.A.N.] [RFC v4 09/19] batman-adv: Add distributed_arp_table mesh genl configuration

Sven Eckelmann
2019-01-19T15:56:16Z

The mesh interface can use a distributed hash table to answer ARP requests
without flooding the request through the whole mesh.

The BATADV_CMD_SET_MESH/BATADV_CMD_GET_MESH commands allow to set/get the
configuration of this feature using the
BATADV_ATTR_DISTRIBUTED_ARP_TABLE_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: Antonio Quartulli <a@unstable.cc>
---
include/uapi/linux/batman_adv.h | 8 ++++++++
net/batman-adv/netlink.c | 17 +++++++++++++++++
2 files changed, 25 insertions(+)

diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h
index 3cb35c66..f303a149 100644
--- a/include/uapi/linux/batman_adv.h
+++ b/include/uapi/linux/batman_adv.h
@@ -388,6 +388,14 @@ enum batadv_nl_attrs {
*/
BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED,

+ /**
+ * @BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED: whether the distributed
+ * arp table feature is enabled. This feature uses a distributed hash
+ * table to answer ARP requests without flooding the request through
+ * the whole mesh.
+ */
+ BATADV_ATTR_DISTRIBUTED_ARP_TABLE_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 0a29dc75..68440d2f 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -145,6 +145,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_ISOLATION_MASK] = { .type = NLA_U32 },
[BATADV_ATTR_BONDING_ENABLED] = { .type = NLA_U8 },
[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE_ENABLED] = { .type = NLA_U8 },
+ [BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED] = { .type = NLA_U8 },
};

/**
@@ -291,6 +292,12 @@ static int batadv_netlink_mesh_put(struct sk_buff *msg,
goto nla_put_failure;
#endif /* CONFIG_BATMAN_ADV_BLA */

+#ifdef CONFIG_BATMAN_ADV_DAT
+ if (nla_put_u8(msg, BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED,
+ !!atomic_read(&bat_priv->distributed_arp_table)))
+ goto nla_put_failure;
+#endif /* CONFIG_BATMAN_ADV_DAT */
+
if (primary_if)
batadv_hardif_put(primary_if);

@@ -415,6 +422,16 @@ static int batadv_netlink_set_mesh(struct sk_buff *skb, struct genl_info *info)
}
#endif /* CONFIG_BATMAN_ADV_BLA */

+#ifdef CONFIG_BATMAN_ADV_DAT
+ if (info->attrs[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED]) {
+ attr = info->attrs[BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED];
+
+ atomic_set(&bat_priv->distributed_arp_table,
+ !!nla_get_u8(attr));
+ batadv_dat_status_update(bat_priv->soft_iface);
+ }
+#endif /* CONFIG_BATMAN_ADV_DAT */
+
batadv_netlink_notify_mesh(bat_priv);

return 0;
--
2.20.1