The mesh interface can fragment unicast packets when the packet size
exceeds the outgoing slave/hard-interface MTU.
The BATADV_CMD_SET_MESH/BATADV_CMD_GET_MESH commands allow to set/get the
configuration of this feature using the BATADV_ATTR_FRAGMENTATION
attribute. Setting the u8 to zero will disable this feature and setting it
to something else is enabling this feature.
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
include/uapi/linux/batman_adv.h | 7 +++++++
net/batman-adv/netlink.c | 12 ++++++++++++
2 files changed, 19 insertions(+)
@@ -395,6 +395,13 @@ enum batadv_nl_attrs {
*/
BATADV_ATTR_DISTRIBUTED_ARP_TABLE,
+ /**
+ * @BATADV_ATTR_FRAGMENTATION: whether the data traffic going through
+ * the mesh will be fragmented or silently discarded if the packet size
+ * exceeds the outgoing interface MTU.
+ */
+ BATADV_ATTR_FRAGMENTATION,
+
/* add attributes above here, update the policy in netlink.c */
/**
@@ -146,6 +146,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_BONDING] = { .type = NLA_U8 },
[BATADV_ATTR_BRIDGE_LOOP_AVOIDANCE] = { .type = NLA_U8 },
[BATADV_ATTR_DISTRIBUTED_ARP_TABLE] = { .type = NLA_U8 },
+ [BATADV_ATTR_FRAGMENTATION] = { .type = NLA_U8 },
};
/**
@@ -297,6 +298,10 @@ static int batadv_netlink_mesh_put(struct sk_buff *msg,
goto nla_put_failure;
#endif /* CONFIG_BATMAN_ADV_DAT */
+ if (nla_put_u8(msg, BATADV_ATTR_FRAGMENTATION,
+ !!atomic_read(&bat_priv->fragmentation)))
+ goto nla_put_failure;
+
batadv_hardif_put(primary_if);
genlmsg_end(msg, hdr);
@@ -430,6 +435,13 @@ static int batadv_netlink_set_mesh(struct sk_buff *skb, struct genl_info *info)
}
#endif /* CONFIG_BATMAN_ADV_DAT */
+ if (info->attrs[BATADV_ATTR_FRAGMENTATION]) {
+ attr = info->attrs[BATADV_ATTR_FRAGMENTATION];
+
+ atomic_set(&bat_priv->fragmentation, !!nla_get_u8(attr));
+ batadv_update_min_mtu(bat_priv->soft_iface);
+ }
+
batadv_netlink_notify_mesh(bat_priv);
return 0;