From: Matthias Schiffer Date: Tue, 23 Jan 2018 09:59:49 +0000 (+0100) Subject: batman-adv: fix packet checksum in receive path X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b6aa03f189cde8996534ca55e8b8e15c719359ed;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git batman-adv: fix packet checksum in receive path [ 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 Signed-off-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 49e16b6e0ba3..84c1b388d9ed 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -448,13 +448,7 @@ void batadv_interface_rx(struct net_device *soft_iface, /* 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,