lkml.org 
[lkml]   [2018]   [May]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 142/496] batman-adv: fix packet checksum in receive path
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Matthias Schiffer <mschiffer@universe-factory.net>

[ Upstream commit abd6360591d3f8259f41c34e31ac4826dfe621b8 ]

eth_type_trans() internally calls skb_pull(), which does not adjust the
skb checksum; skb_postpull_rcsum() is necessary to avoid log spam of the
form "bat0: hw csum failure" when packets with CHECKSUM_COMPLETE are
received.

Note that in usual setups, packets don't reach batman-adv with
CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see
batadv's ethtype?), which is why the log messages do not occur on every
system using batman-adv. I could reproduce this issue by stacking
batman-adv on top of a VXLAN interface.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Tested-by: Maximilian Wilhelm <max@sdn.clinic>
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/batman-adv/soft-interface.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)

--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -451,13 +451,7 @@ void batadv_interface_rx(struct net_devi

/* skb->dev & skb->pkt_type are set here */
skb->protocol = eth_type_trans(skb, soft_iface);
-
- /* should not be necessary anymore as we use skb_pull_rcsum()
- * TODO: please verify this and remove this TODO
- * -- Dec 21st 2009, Simon Wunderlich
- */
-
- /* skb->ip_summed = CHECKSUM_UNNECESSARY; */
+ skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);

batadv_inc_counter(bat_priv, BATADV_CNT_RX);
batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,

\
 
 \ /
  Last update: 2018-05-28 15:23    [W:0.882 / U:0.140 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site