diff options
author | Steffen Klassert <steffen.klassert@secunet.com> | 2011-03-08 00:07:51 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2011-03-13 20:22:29 -0700 |
commit | d212a4c29096484e5e83b5006e695add126260af (patch) | |
tree | 00f5c3bcbc7560591820070364d78e21c241be34 /net/ipv6 | |
parent | 0dc49e9b28a7253ff05be2794d747f8ea5f1f423 (diff) |
esp6: Add support for IPsec extended sequence numbers
This patch adds IPsec extended sequence numbers support to esp6.
We use the authencesn crypto algorithm to handle esp with separate
encryption/authentication algorithms.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
-rw-r--r-- | net/ipv6/esp6.c | 105 |
1 files changed, 86 insertions, 19 deletions
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index c7b5d5ee0de..5aa8ec88f19 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -54,16 +54,20 @@ static u32 esp6_get_mtu(struct xfrm_state *x, int mtu); /* * Allocate an AEAD request structure with extra space for SG and IV. * - * For alignment considerations the IV is placed at the front, followed - * by the request and finally the SG list. + * For alignment considerations the upper 32 bits of the sequence number are + * placed at the front, if present. Followed by the IV, the request and finally + * the SG list. * * 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 seqihlen) { unsigned int len; - len = crypto_aead_ivsize(aead); + len = seqihlen; + + len += crypto_aead_ivsize(aead); + if (len) { len += crypto_aead_alignmask(aead) & ~(crypto_tfm_ctx_alignment() - 1); @@ -78,10 +82,16 @@ 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( @@ -145,8 +155,12 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) int plen; int tfclen; int nfrags; + int assoclen; + int sglists; + int seqhilen; u8 *iv; u8 *tail; + __be32 *seqhi; struct esp_data *esp = x->data; /* skb is pure payload to encrypt */ @@ -175,14 +189,25 @@ static int esp6_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); @@ -210,11 +235,19 @@ static int esp6_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); @@ -292,8 +325,12 @@ static int esp6_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; int ret = 0; void *tmp; + __be32 *seqhi; u8 *iv; struct scatterlist *sg; struct scatterlist *asg; @@ -314,12 +351,24 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) } ret = -ENOMEM; - 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 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; @@ -333,11 +382,19 @@ static int esp6_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); ret = crypto_aead_decrypt(req); if (ret == -EINPROGRESS) @@ -443,10 +500,20 @@ 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); |