Subject: Re: [PATCHv3 net-next 2/5] {IPv4,xfrm} Add ESN support for AH ingress part

From: Steffen Klassert <[email-masked]>
Date: Tue, 14 Jan 2014 11:34:27 +0100

On Tue, Jan 14, 2014 at 06:17:26PM +0800, Fan Du wrote:
> 
> 
> On 2014年01月14日 18:09, Steffen Klassert wrote:
> >On Tue, Jan 14, 2014 at 06:01:32PM +0800, Fan Du wrote:
> >>
> >>
> >>On 2014年01月14日 17:54, Steffen Klassert wrote:
> >>>On Tue, Jan 14, 2014 at 09:39:09AM +0800, Fan Du wrote:
> >>>>@@ -381,7 +393,14 @@ static int ah_input(struct xfrm_state *x, struct sk_buff *skb)
> >>>>  	sg_init_table(sg, nfrags);
> >>>>  	skb_to_sgvec(skb, sg, 0, skb->len);
> >>>>
> >>>>-	ahash_request_set_crypt(req, sg, icv, skb->len);
> >>>>+	if (x->props.flags&   XFRM_STATE_ESN) {
> >>>>+		sg_unmark_end(&sg[nfrags - 1]);
> >>>>+		/* Attach seqhi sg right after packet payload */
> >>>>+		*seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
> >>>
> >>>This is ah_input(), so you should use the high bits of the input
> >>>sequence number here. The ipv6 patch has the same problem.
> >>
> >>ok, I will fix this.
> >>
> >>>
> >>>>+		sg_init_table(seqhisg, sglists);
> >>>
> >>>Why do you add a separate SG table for this?
> >>
> >>It just initialize a single seqhisg, which is actually followed behind packet payload sg table.
> >>initialized seqhisg actually mark itself as the end of sg list.
> >>
> >
> >Why don't you just add this entry to the existing SG table?
> >
> 
> Do you mean scatterwalk_crypto_chain ?

No, I mean something like:

sg_init_table(sg, nfrags + sglists)

if (x->props.flags & XFRM_STATE_ESN) {
	*seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
	sg_set_buf(sg + nfrags, seqhi, seqhi_len);
}