From 88e48d7b3340ef07b108eb8a8b3813dd093cc7f7 Mon Sep 17 00:00:00 2001 From: Antonio Quartulli Date: Thu, 9 May 2013 09:35:45 +0200 Subject: [PATCH] batman-adv: make DAT drop ARP requests targeting local clients In the outgoing ARP request snooping routine in DAT, ARP Request sent by local clients which are supposed to be replied by other local clients can be silently dropped. The destination host will reply by itself through the LAN and therefore there is no need to involve DAT. Reported-by: Carlos Quijano Signed-off-by: Antonio Quartulli Tested-by: Carlos Quijano Signed-off-by: Marek Lindner --- net/batman-adv/distributed-arp-table.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 8e15d966d9b0..239992021b1d 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -837,6 +837,19 @@ bool batadv_dat_snoop_outgoing_arp_request(struct batadv_priv *bat_priv, dat_entry = batadv_dat_entry_hash_find(bat_priv, ip_dst); if (dat_entry) { + /* If the ARP request is destined for a local client the local + * client will answer itself. DAT would only generate a + * duplicate packet. + * + * Moreover, if the soft-interface is enslaved into a bridge, an + * additional DAT answer may trigger kernel warnings about + * a packet coming from the wrong port. + */ + if (batadv_is_my_client(bat_priv, dat_entry->mac_addr)) { + ret = true; + goto out; + } + skb_new = arp_create(ARPOP_REPLY, ETH_P_ARP, ip_src, bat_priv->soft_iface, ip_dst, hw_src, dat_entry->mac_addr, hw_src); -- 2.20.1