2007-02-03 02:45:18

by Chris Wright

[permalink] [raw]
Subject: [patch 53/59] TCP: rare bad TCP checksum with 2.6.19

-stable review patch. If anyone has any objections, please let us know.
------------------

From: Jarek Poplawski <[email protected]>

The patch "Replace CHECKSUM_HW by CHECKSUM_PARTIAL/CHECKSUM_COMPLETE"
changed to unconditional copying of ip_summed field from collapsed
skb. This patch reverts this change.

The majority of substantial work including heavy testing
and diagnosing by: Michael Tokarev <[email protected]>
Possible reasons pointed by: Herbert Xu and Patrick McHardy.

Signed-off-by: Jarek Poplawski <[email protected]>
Acked-by: Herbert Xu <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
net/ipv4/tcp_output.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- linux-2.6.19.2.orig/net/ipv4/tcp_output.c
+++ linux-2.6.19.2/net/ipv4/tcp_output.c
@@ -1590,7 +1590,8 @@ static void tcp_retrans_try_collapse(str

memcpy(skb_put(skb, next_skb_size), next_skb->data, next_skb_size);

- skb->ip_summed = next_skb->ip_summed;
+ if (next_skb->ip_summed == CHECKSUM_PARTIAL)
+ skb->ip_summed = CHECKSUM_PARTIAL;

if (skb->ip_summed != CHECKSUM_PARTIAL)
skb->csum = csum_block_add(skb->csum, next_skb->csum, skb_size);

--