diff options
| author | Tom Herbert <therbert@google.com> | 2014-06-14 23:24:03 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-06-15 01:00:49 -0700 |
| commit | 46fb51eb96cafb2c148b7b5119adb5e31a2bf3c4 (patch) | |
| tree | 8deefff573270378b056f6f0915068a33578b2ad /net | |
| parent | 4b28252cada3d0521ab59751f4240ecdfb9bba18 (diff) | |
net: Fix save software checksum complete
Geert reported issues regarding checksum complete and UDP.
The logic introduced in commit 7e3cead5172927732f51fde
("net: Save software checksum complete") is not correct.
This patch:
1) Restores code in __skb_checksum_complete_header except for setting
CHECKSUM_UNNECESSARY. This function may be calculating checksum on
something less than skb->len.
2) Adds saving checksum to __skb_checksum_complete. The full packet
checksum 0..skb->len is calculated without adding in pseudo header.
This value is saved in skb->csum and then the pseudo header is added
to that to derive the checksum for validation.
3) In both __skb_checksum_complete_header and __skb_checksum_complete,
set skb->csum_valid to whether checksum of zero was computed. This
allows skb_csum_unnecessary to return true without changing to
CHECKSUM_UNNECESSARY which was done previously.
4) Copy new csum related bits in __copy_skb_header.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/datagram.c | 36 | ||||
| -rw-r--r-- | net/core/skbuff.c | 3 |
2 files changed, 29 insertions, 10 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 6b1c04ca1d50..488dd1a825c0 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -739,22 +739,38 @@ __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len) __sum16 sum; sum = csum_fold(skb_checksum(skb, 0, len, skb->csum)); - if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && !sum && - !skb->csum_complete_sw) - netdev_rx_csum_fault(skb->dev); - - /* Save checksum complete for later use */ - skb->csum = sum; - skb->ip_summed = CHECKSUM_COMPLETE; - skb->csum_complete_sw = 1; - + if (likely(!sum)) { + if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && + !skb->csum_complete_sw) + netdev_rx_csum_fault(skb->dev); + } + skb->csum_valid = !sum; return sum; } EXPORT_SYMBOL(__skb_checksum_complete_head); __sum16 __skb_checksum_complete(struct sk_buff *skb) { - return __skb_checksum_complete_head(skb, skb->len); + __wsum csum; + __sum16 sum; + + csum = skb_checksum(skb, 0, skb->len, 0); + + /* skb->csum holds pseudo checksum */ + sum = csum_fold(csum_add(skb->csum, csum)); + if (likely(!sum)) { + if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) && + !skb->csum_complete_sw) + netdev_rx_csum_fault(skb->dev); + } + + /* Save full packet checksum */ + skb->csum = csum; + skb->ip_summed = CHECKSUM_COMPLETE; + skb->csum_complete_sw = 1; + skb->csum_valid = !sum; + + return sum; } EXPORT_SYMBOL(__skb_checksum_complete); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index bf92824af3f7..9cd5344fad73 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -689,6 +689,9 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) new->ooo_okay = old->ooo_okay; new->no_fcs = old->no_fcs; new->encapsulation = old->encapsulation; + new->encap_hdr_csum = old->encap_hdr_csum; + new->csum_valid = old->csum_valid; + new->csum_complete_sw = old->csum_complete_sw; #ifdef CONFIG_XFRM new->sp = secpath_get(old->sp); #endif |