{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: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 7179026..c6accac 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -155,6 +155,10 @@
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 @@
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 @@
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;