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esp4: Add support for IPsec extended sequence numbers

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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 <steffen.klassert@secunet.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Steffen Klassert 2011-03-08 00:07:14 +00:00 committed by David S. Miller
parent 1ce3644ade
commit 0dc49e9b28
1 changed files with 82 additions and 18 deletions
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90
net/ipv4/esp4.c
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@ -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);
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);
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)",
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);