Repository : ssh://git@open-mesh.org/batman-adv
On branch : master
commit 2c1bce065baa688bc1eca4116f83ca3b790432a5 Author: Matthias Schiffer mschiffer@universe-factory.net Date: Tue Jan 23 10:59:50 2018 +0100
batman-adv: invalidate checksum on fragment reassembly
A more sophisticated implementation could try to combine fragment checksums when all fragments have CHECKSUM_COMPLETE and are split at even offsets. For now, we just set ip_summed to CHECKSUM_NONE to avoid "hw csum failure" warnings in the kernel log when fragmented frames are received. In consequence, skb_pull_rcsum() can be replaced with skb_pull().
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: 9b3eab61754d ("batman-adv: Receive fragmented packets and merge") Signed-off-by: Matthias Schiffer mschiffer@universe-factory.net Signed-off-by: Sven Eckelmann sven@narfation.org
2c1bce065baa688bc1eca4116f83ca3b790432a5 net/batman-adv/fragmentation.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index ebe6e38..1bb2b43 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -287,7 +287,8 @@ batadv_frag_merge_packets(struct hlist_head *chain) /* Move the existing MAC header to just before the payload. (Override * the fragment header.) */ - skb_pull_rcsum(skb_out, hdr_size); + skb_pull(skb_out, hdr_size); + skb_out->ip_summed = CHECKSUM_NONE; memmove(skb_out->data - ETH_HLEN, skb_mac_header(skb_out), ETH_HLEN); skb_set_mac_header(skb_out, -ETH_HLEN); skb_reset_network_header(skb_out);