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net: Save software checksum complete

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In skb_checksum complete, if we need to compute the checksum for the
packet (via skb_checksum) save the result as CHECKSUM_COMPLETE.
Subsequent checksum verification can use this.

Also, added csum_complete_sw flag to distinguish between software and
hardware generated checksum complete, we should always be able to trust
the software computation.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2014-06-10 18:54:19 -07:00 committed by David S. Miller
parent 5d0c2b95bc
commit 7e3cead517
4 changed files with 17 additions and 9 deletions
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3
include/linux/skbuff.h
View file

@ -573,7 +573,8 @@ struct sk_buff {
__u8 encapsulation:1; __u8 encapsulation:1;
__u8 encap_hdr_csum:1; __u8 encap_hdr_csum:1;
__u8 csum_valid:1; __u8 csum_valid:1;
/* 4/6 bit hole (depending on ndisc_nodetype presence) */ __u8 csum_complete_sw:1;
/* 3/5 bit hole (depending on ndisc_nodetype presence) */
kmemcheck_bitfield_end(flags2); kmemcheck_bitfield_end(flags2);
#if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL

14
net/core/datagram.c
View file

@ -739,11 +739,15 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len)
__sum16 sum; __sum16 sum;
sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); sum = csum_fold(skb_checksum(skb, 0, len, skb->csum));
if (likely(!sum)) { if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && !sum &&
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) !skb->csum_complete_sw)
netdev_rx_csum_fault(skb->dev); netdev_rx_csum_fault(skb->dev);
skb->ip_summed = CHECKSUM_UNNECESSARY;
} /* Save checksum complete for later use */
skb->csum = sum;
skb->ip_summed = CHECKSUM_COMPLETE;
skb->csum_complete_sw = 1;
return sum; return sum;
} }
EXPORT_SYMBOL(__skb_checksum_complete_head); EXPORT_SYMBOL(__skb_checksum_complete_head);

6
net/ipv4/gre_offload.c
View file

@ -131,10 +131,12 @@ static __sum16 gro_skb_checksum(struct sk_buff *skb)
csum_partial(skb->data, skb_gro_offset(skb), 0)); csum_partial(skb->data, skb_gro_offset(skb), 0));
sum = csum_fold(NAPI_GRO_CB(skb)->csum); sum = csum_fold(NAPI_GRO_CB(skb)->csum);
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) { if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) {
if (unlikely(!sum)) if (unlikely(!sum) && !skb->csum_complete_sw)
netdev_rx_csum_fault(skb->dev); netdev_rx_csum_fault(skb->dev);
} else } else {
skb->ip_summed = CHECKSUM_COMPLETE; skb->ip_summed = CHECKSUM_COMPLETE;
skb->csum_complete_sw = 1;
}
return sum; return sum;
} }

3
net/sunrpc/socklib.c
View file

@ -173,7 +173,8 @@ int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
return -1; return -1;
if (csum_fold(desc.csum)) if (csum_fold(desc.csum))
return -1; return -1;
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
!skb->csum_complete_sw)
netdev_rx_csum_fault(skb->dev); netdev_rx_csum_fault(skb->dev);
return 0; return 0;
no_checksum: no_checksum: