Re: [BUG] sky2 broken for Yukon PCI-E Gigabit Ethernet Controller11ab:4362 (rev 19)

From: Patrick McHardy
Date: Fri Jan 27 2006 - 10:26:47 EST


Herbert Xu wrote:
> On Fri, Jan 27, 2006 at 07:07:34AM +0100, Knut Petersen wrote:
>
>>Well, there are no problems if SuSEfirewall2 is disabled. But have a look
>>at the loaded modules:
>>
>>ipt_MASQUERADE 3968 1
>>pppoe 15360 2
>>pppox 4616 1 pppoe
>
>
> OK, although we can't rule out sky2/netfilter from the enquiry, I've
> identified two bugs in ppp/pppoe that may be responsible for what you
> are seeing. So please try the following patch and let us know if the
> problem still exists (or deteriorates/improves).
>
> [PPP]: Fixed hardware RX checksum handling
>
> When we pull the PPP protocol off the skb, we forgot to update the
> hardware RX checksum. This may lead to messages such as
>
> dsl0: hw csum failure.
>
> Similarly, we need to clear the hardware checksum flag when we use
> the existing packet to store the decompressed result.

We had a couple of reports of incorrect hardware checksums with
PPPoE. KdF, can you test Herbert's patch (attached again to this
mail) please?
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -1610,6 +1610,8 @@ ppp_receive_nonmp_frame(struct ppp *ppp,
}
else if (!pskb_may_pull(skb, skb->len))
goto err;
+ else
+ skb->ip_summed = CHECKSUM_NONE;

len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2);
if (len <= 0) {
@@ -1690,6 +1692,7 @@ ppp_receive_nonmp_frame(struct ppp *ppp,
kfree_skb(skb);
} else {
skb_pull(skb, 2); /* chop off protocol */
+ skb_postpull_rcsum(skb, skb->data - 2, 2);
skb->dev = ppp->dev;
skb->protocol = htons(npindex_to_ethertype[npi]);
skb->mac.raw = skb->data;