On Fri, Jan 19, 2007 at 01:14:52PM +0100, Patrick McHardy wrote: > Jarek Poplawski wrote: > > Here is my patch proposal. If I'm not totally wrong, > > there is a possibility that, during collapsing, empty > > skb with FIN is added to "normal" packet and changes > > its ip_summed field to CHECKSUM_NONE. > > > > diff -Nurp linux-2.6.19-/net/ipv4/tcp_output.c > > linux-2.6.19/net/ipv4/tcp_output.c > > --- linux-2.6.19-/net/ipv4/tcp_output.c 2006-11-29 22:57:37.000000000 > > +0100 > > +++ linux-2.6.19/net/ipv4/tcp_output.c 2007-01-19 07:58:39.000000000 > > +0100 > > @@ -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); > > > > I noticed this too, but I can't see how it could lead to > a partial checksum on the wire since the checksumming is > done after changing ip_summed to CHECKSUM_NONE. Is this > patch verified to fix Michael's problem?
No, this was intended as a proposal for testing. I didn't verify all the checksum path here, but I guessed such change during the summing could matter (probably for skb_copy_and_csum_dev and maybe earlier) and I couldn't find more suspicious change since 2.6.17 near this FINs. But if it really works, it shoudn't be so hard to verify the mechanism, I hope. Jarek P. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
