Commit d4d573d0 authored by Fan Du's avatar Fan Du Committed by Steffen Klassert

{IPv4,xfrm} Add ESN support for AH egress part

This patch add esn support for AH output 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 out.
Signed-off-by: default avatarFan Du <fan.du@windriver.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent 25a91d8d
......@@ -155,6 +155,10 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
struct iphdr *iph, *top_iph;
struct ip_auth_hdr *ah;
struct ah_data *ahp;
int seqhi_len = 0;
__be32 *seqhi;
int sglists = 0;
struct scatterlist *seqhisg;
ahp = x->data;
ahash = ahp->ahash;
......@@ -167,14 +171,19 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
ah = ip_auth_hdr(skb);
ihl = ip_hdrlen(skb);
if (x->props.flags & XFRM_STATE_ESN) {
sglists = 1;
seqhi_len = sizeof(*seqhi);
}
err = -ENOMEM;
iph = ah_alloc_tmp(ahash, nfrags, ihl);
iph = ah_alloc_tmp(ahash, nfrags + sglists, ihl + seqhi_len);
if (!iph)
goto out;
icv = ah_tmp_icv(ahash, iph, ihl);
seqhi = (__be32 *)((char *)iph + ihl);
icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
req = ah_tmp_req(ahash, icv);
sg = ah_req_sg(ahash, req);
seqhisg = sg + nfrags;
memset(ah->auth_data, 0, ahp->icv_trunc_len);
......@@ -210,10 +219,15 @@ static int ah_output(struct xfrm_state *x, struct sk_buff *skb)
ah->spi = x->id.spi;
ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
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);
ahash_request_set_crypt(req, sg, icv, skb->len);
if (x->props.flags & XFRM_STATE_ESN) {
/* Attach seqhi sg right after packet payload */
*seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
sg_set_buf(seqhisg, seqhi, seqhi_len);
}
ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
ahash_request_set_callback(req, 0, ah_output_done, skb);
AH_SKB_CB(skb)->tmp = iph;
......
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