From 0dc49e9b28a7253ff05be2794d747f8ea5f1f423 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Tue, 8 Mar 2011 00:07:14 +0000 Subject: [PATCH] esp4: Add support for IPsec extended sequence numbers This patch adds IPsec extended sequence numbers support to esp4. We use the authencesn crypto algorithm to handle esp with separate encryption/authentication algorithms. Signed-off-by: Steffen Klassert Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/esp4.c | 100 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 82 insertions(+), 18 deletions(-) diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 882dbbb7d799..03f994bcf7de 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -33,11 +33,14 @@ static u32 esp4_get_mtu(struct xfrm_state *x, int mtu); * * TODO: Use spare space in skb for this where possible. */ -static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags) +static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen) { unsigned int len; - len = crypto_aead_ivsize(aead); + len = seqhilen; + + len += crypto_aead_ivsize(aead); + if (len) { len += crypto_aead_alignmask(aead) & ~(crypto_tfm_ctx_alignment() - 1); @@ -52,10 +55,15 @@ static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags) return kmalloc(len, GFP_ATOMIC); } -static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp) +static inline __be32 *esp_tmp_seqhi(void *tmp) +{ + return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); +} +static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) { return crypto_aead_ivsize(aead) ? - PTR_ALIGN((u8 *)tmp, crypto_aead_alignmask(aead) + 1) : tmp; + PTR_ALIGN((u8 *)tmp + seqhilen, + crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; } static inline struct aead_givcrypt_request *esp_tmp_givreq( @@ -122,6 +130,10 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) int plen; int tfclen; int nfrags; + int assoclen; + int sglists; + int seqhilen; + __be32 *seqhi; /* skb is pure payload to encrypt */ @@ -151,14 +163,25 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) goto error; nfrags = err; - tmp = esp_alloc_tmp(aead, nfrags + 1); + assoclen = sizeof(*esph); + sglists = 1; + seqhilen = 0; + + if (x->props.flags & XFRM_STATE_ESN) { + sglists += 2; + seqhilen += sizeof(__be32); + assoclen += seqhilen; + } + + tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen); if (!tmp) goto error; - iv = esp_tmp_iv(aead, tmp); + seqhi = esp_tmp_seqhi(tmp); + iv = esp_tmp_iv(aead, tmp, seqhilen); req = esp_tmp_givreq(aead, iv); asg = esp_givreq_sg(aead, req); - sg = asg + 1; + sg = asg + sglists; /* Fill padding... */ tail = skb_tail_pointer(trailer); @@ -221,11 +244,19 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) skb_to_sgvec(skb, sg, esph->enc_data + crypto_aead_ivsize(aead) - skb->data, clen + alen); - sg_init_one(asg, esph, sizeof(*esph)); + + if ((x->props.flags & XFRM_STATE_ESN)) { + sg_init_table(asg, 3); + sg_set_buf(asg, &esph->spi, sizeof(__be32)); + *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); + sg_set_buf(asg + 1, seqhi, seqhilen); + sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32)); + } else + sg_init_one(asg, esph, sizeof(*esph)); aead_givcrypt_set_callback(req, 0, esp_output_done, skb); aead_givcrypt_set_crypt(req, sg, sg, clen, iv); - aead_givcrypt_set_assoc(req, asg, sizeof(*esph)); + aead_givcrypt_set_assoc(req, asg, assoclen); aead_givcrypt_set_giv(req, esph->enc_data, XFRM_SKB_CB(skb)->seq.output.low); @@ -346,6 +377,10 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb) struct sk_buff *trailer; int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead); int nfrags; + int assoclen; + int sglists; + int seqhilen; + __be32 *seqhi; void *tmp; u8 *iv; struct scatterlist *sg; @@ -362,16 +397,27 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb) goto out; nfrags = err; + assoclen = sizeof(*esph); + sglists = 1; + seqhilen = 0; + + if (x->props.flags & XFRM_STATE_ESN) { + sglists += 2; + seqhilen += sizeof(__be32); + assoclen += seqhilen; + } + err = -ENOMEM; - tmp = esp_alloc_tmp(aead, nfrags + 1); + tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen); if (!tmp) goto out; ESP_SKB_CB(skb)->tmp = tmp; - iv = esp_tmp_iv(aead, tmp); + seqhi = esp_tmp_seqhi(tmp); + iv = esp_tmp_iv(aead, tmp, seqhilen); req = esp_tmp_req(aead, iv); asg = esp_req_sg(aead, req); - sg = asg + 1; + sg = asg + sglists; skb->ip_summed = CHECKSUM_NONE; @@ -382,11 +428,19 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb) sg_init_table(sg, nfrags); skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen); - sg_init_one(asg, esph, sizeof(*esph)); + + if ((x->props.flags & XFRM_STATE_ESN)) { + sg_init_table(asg, 3); + sg_set_buf(asg, &esph->spi, sizeof(__be32)); + *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; + sg_set_buf(asg + 1, seqhi, seqhilen); + sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32)); + } else + sg_init_one(asg, esph, sizeof(*esph)); aead_request_set_callback(req, 0, esp_input_done, skb); aead_request_set_crypt(req, sg, sg, elen, iv); - aead_request_set_assoc(req, asg, sizeof(*esph)); + aead_request_set_assoc(req, asg, assoclen); err = crypto_aead_decrypt(req); if (err == -EINPROGRESS) @@ -500,10 +554,20 @@ static int esp_init_authenc(struct xfrm_state *x) goto error; err = -ENAMETOOLONG; - if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, "authenc(%s,%s)", - x->aalg ? x->aalg->alg_name : "digest_null", - x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME) - goto error; + + if ((x->props.flags & XFRM_STATE_ESN)) { + if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, + "authencesn(%s,%s)", + x->aalg ? x->aalg->alg_name : "digest_null", + x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME) + goto error; + } else { + if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, + "authenc(%s,%s)", + x->aalg ? x->aalg->alg_name : "digest_null", + x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME) + goto error; + } aead = crypto_alloc_aead(authenc_name, 0, 0); err = PTR_ERR(aead); -- 2.20.1