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Commit 0dc49e9b authored by Steffen Klassert's avatar Steffen Klassert Committed by David S. Miller
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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: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1ce3644a

net/ipv4/esp4.c

+82 −18
Original line number Diff line number Diff line
@@ -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);