Commit 8d6da6f3 authored by Fan Du's avatar Fan Du Committed by Steffen Klassert
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{IPv6,xfrm} Add ESN support for AH ingress part 



This patch add esn support for AH input stage by attaching upper 32bits
sequence number right after packet payload as specified by RFC 4302.

Then the ICV value will guard upper 32bits sequence number as well when
packet going in.

Signed-off-by: default avatarFan Du <fan.du@windriver.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent 26dd70c3

net/ipv6/ah6.c

+24 −6
Original line number Diff line number Diff line
@@ -530,6 +530,10 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 
	int nexthdr;

	int nfrags;

	int err = -ENOMEM;

	int seqhi_len = 0;

	__be32 *seqhi;

	int sglists = 0;

	struct scatterlist *seqhisg;



	if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))

		goto out;
@@ -566,14 +570,22 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 


	skb_push(skb, hdr_len);



	work_iph = ah_alloc_tmp(ahash, nfrags, hdr_len + ahp->icv_trunc_len);

	if (x->props.flags & XFRM_STATE_ESN) {

		sglists = 1;

		seqhi_len = sizeof(*seqhi);

	}



	work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +

				ahp->icv_trunc_len + seqhi_len);

	if (!work_iph)

		goto out;



	auth_data = ah_tmp_auth(work_iph, hdr_len);

	icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);

	auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);

	seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);

	icv = ah_tmp_icv(ahash, seqhi, seqhi_len);

	req = ah_tmp_req(ahash, icv);

	sg = ah_req_sg(ahash, req);

	seqhisg = sg + nfrags;



	memcpy(work_iph, ip6h, hdr_len);

	memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
@@ -588,10 +600,16 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) 
	ip6h->flow_lbl[2] = 0;

	ip6h->hop_limit   = 0;



	sg_init_table(sg, nfrags);

	skb_to_sgvec(skb, sg, 0, skb->len);

	sg_init_table(sg, nfrags + sglists);

	skb_to_sgvec_nomark(skb, sg, 0, skb->len);



	if (x->props.flags & XFRM_STATE_ESN) {

		/* Attach seqhi sg right after packet payload */

		*seqhi = XFRM_SKB_CB(skb)->seq.input.hi;

		sg_set_buf(seqhisg, seqhi, seqhi_len);

	}



	ahash_request_set_crypt(req, sg, icv, skb->len);

	ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);

	ahash_request_set_callback(req, 0, ah6_input_done, skb);



	AH_SKB_CB(skb)->tmp = work_iph;

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