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_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: Andreas Langer an.langer@gmx.de Cc: Martin Hundeboll martin@hundeboll.net Cc: Marek Lindner mareklindner@neomailbox.ch --- include/uapi/linux/batman_adv.h | 7 +++++++ net/batman-adv/netlink.c | 12 ++++++++++++ 2 files changed, 19 insertions(+)
diff --git a/include/uapi/linux/batman_adv.h b/include/uapi/linux/batman_adv.h index f303a149..847841b8 100644 --- a/include/uapi/linux/batman_adv.h +++ b/include/uapi/linux/batman_adv.h @@ -396,6 +396,13 @@ enum batadv_nl_attrs { */ BATADV_ATTR_DISTRIBUTED_ARP_TABLE_ENABLED,
+ /** + * @BATADV_ATTR_FRAGMENTATION_ENABLED: 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_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 68440d2f..45f6aee5 100644 --- a/net/batman-adv/netlink.c +++ b/net/batman-adv/netlink.c @@ -146,6 +146,7 @@ static const struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = { [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 }, + [BATADV_ATTR_FRAGMENTATION_ENABLED] = { .type = NLA_U8 }, };
/** @@ -298,6 +299,10 @@ 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_ENABLED, + !!atomic_read(&bat_priv->fragmentation))) + goto nla_put_failure; + if (primary_if) batadv_hardif_put(primary_if);
@@ -432,6 +437,13 @@ 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_ENABLED]) { + attr = info->attrs[BATADV_ATTR_FRAGMENTATION_ENABLED]; + + 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;