net: Allow GRO to use and set levels of checksum unnecessary
authorTom Herbert <therbert@google.com>
Thu, 28 Aug 2014 04:26:56 +0000 (21:26 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sat, 30 Aug 2014 03:41:11 +0000 (20:41 -0700)
commit662880f4420340aad4f9a62a349c6c9d4faa1a5d
treed62876eeef140de3256a22f0632571dc00c9745c
parent77cffe23c1f88835f6bd7b47bfa0c060c2969828
net: Allow GRO to use and set levels of checksum unnecessary

Allow GRO path to "consume" checksums provided in CHECKSUM_UNNECESSARY
and to report new checksums verfied for use in fallback to normal
path.

Change GRO checksum path to track csum_level using a csum_cnt field
in NAPI_GRO_CB. On GRO initialization, if ip_summed is
CHECKSUM_UNNECESSARY set NAPI_GRO_CB(skb)->csum_cnt to
skb->csum_level + 1. For each checksum verified, decrement
NAPI_GRO_CB(skb)->csum_cnt while its greater than zero. If a checksum
is verfied and NAPI_GRO_CB(skb)->csum_cnt == 0, we have verified a
deeper checksum than originally indicated in skbuf so increment
csum_level (or initialize to CHECKSUM_UNNECESSARY if ip_summed is
CHECKSUM_NONE or CHECKSUM_COMPLETE).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/netdevice.h
net/core/dev.c
net/ipv4/gre_offload.c
net/ipv4/udp_offload.c