[deliverable/linux.git] / net / ipv6 / esp6.c

/*
 * Copyright (C)2002 USAGI/WIDE Project
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Authors
 *
 *	Mitsuru KANDA @USAGI       : IPv6 Support 
 * 	Kazunori MIYAZAWA @USAGI   :
 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 * 	
 * 	This file is derived from net/ipv4/esp.c
 */

#include <linux/config.h>
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/esp.h>
#include <asm/scatterlist.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <linux/icmpv6.h>

static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;
	int hdr_len;
	struct ipv6hdr *top_iph;
	struct ipv6_esp_hdr *esph;
	struct crypto_tfm *tfm;
	struct esp_data *esp;
	struct sk_buff *trailer;
	int blksize;
	int clen;
	int alen;
	int nfrags;

	esp = x->data;
	hdr_len = skb->h.raw - skb->data +
		  sizeof(*esph) + esp->conf.ivlen;

	/* Strip IP+ESP header. */
	__skb_pull(skb, hdr_len);

	/* Now skb is pure payload to encrypt */
	err = -ENOMEM;

	/* Round to block size */
	clen = skb->len;

	alen = esp->auth.icv_trunc_len;
	tfm = esp->conf.tfm;
	blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
	clen = ALIGN(clen + 2, blksize);
	if (esp->conf.padlen)
		clen = ALIGN(clen, esp->conf.padlen);

	if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
		goto error;
	}

	/* Fill padding... */
	do {
		int i;
		for (i=0; i<clen-skb->len - 2; i++)
			*(u8*)(trailer->tail + i) = i+1;
	} while (0);
	*(u8*)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
	pskb_put(skb, trailer, clen - skb->len);

	top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
	esph = (struct ipv6_esp_hdr *)skb->h.raw;
	top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
	*(u8*)(trailer->tail - 1) = *skb->nh.raw;
	*skb->nh.raw = IPPROTO_ESP;

	esph->spi = x->id.spi;
	esph->seq_no = htonl(++x->replay.oseq);

	if (esp->conf.ivlen)
		crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));

	do {
		struct scatterlist *sg = &esp->sgbuf[0];

		if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
			sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
			if (!sg)
				goto error;
		}
		skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
		crypto_cipher_encrypt(tfm, sg, sg, clen);
		if (unlikely(sg != &esp->sgbuf[0]))
			kfree(sg);
	} while (0);

	if (esp->conf.ivlen) {
		memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
		crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
	}

	if (esp->auth.icv_full_len) {
		esp->auth.icv(esp, skb, (u8*)esph-skb->data,
			sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
		pskb_put(skb, trailer, alen);
	}

	err = 0;

error:
	return err;
}

static int esp6_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
	struct ipv6hdr *iph;
	struct ipv6_esp_hdr *esph;
	struct esp_data *esp = x->data;
	struct sk_buff *trailer;
	int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
	int alen = esp->auth.icv_trunc_len;
	int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;

	int hdr_len = skb->h.raw - skb->nh.raw;
	int nfrags;
	unsigned char *tmp_hdr = NULL;
	int ret = 0;

	if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
		ret = -EINVAL;
		goto out_nofree;
	}

	if (elen <= 0 || (elen & (blksize-1))) {
		ret = -EINVAL;
		goto out_nofree;
	}

	tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
	if (!tmp_hdr) {
		ret = -ENOMEM;
		goto out_nofree;
	}
	memcpy(tmp_hdr, skb->nh.raw, hdr_len);

	/* If integrity check is required, do this. */
        if (esp->auth.icv_full_len) {
		u8 sum[esp->auth.icv_full_len];
		u8 sum1[alen];

		esp->auth.icv(esp, skb, 0, skb->len-alen, sum);

		if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
			BUG();

		if (unlikely(memcmp(sum, sum1, alen))) {
			x->stats.integrity_failed++;
			ret = -EINVAL;
			goto out;
		}
	}

	if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
		ret = -EINVAL;
		goto out;
	}

	skb->ip_summed = CHECKSUM_NONE;

	esph = (struct ipv6_esp_hdr*)skb->data;
	iph = skb->nh.ipv6h;

	/* Get ivec. This can be wrong, check against another impls. */
	if (esp->conf.ivlen)
		crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));

        {
		u8 nexthdr[2];
		struct scatterlist *sg = &esp->sgbuf[0];
		u8 padlen;

		if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
			sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
			if (!sg) {
				ret = -ENOMEM;
				goto out;
			}
		}
		skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
		crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
		if (unlikely(sg != &esp->sgbuf[0]))
			kfree(sg);

		if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
			BUG();

		padlen = nexthdr[0];
		if (padlen+2 >= elen) {
			LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
			ret = -EINVAL;
			goto out;
		}
		/* ... check padding bits here. Silly. :-) */ 

		pskb_trim(skb, skb->len - alen - padlen - 2);
		skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
		skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
		memcpy(skb->nh.raw, tmp_hdr, hdr_len);
		skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
		ret = nexthdr[1];
	}

out:
	kfree(tmp_hdr);
out_nofree:
	return ret;
}

static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
{
	struct esp_data *esp = x->data;
	u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);

	if (x->props.mode) {
		mtu = ALIGN(mtu + 2, blksize);
	} else {
		/* The worst case. */
		u32 padsize = ((blksize - 1) & 7) + 1;
		mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
	}
	if (esp->conf.padlen)
		mtu = ALIGN(mtu, esp->conf.padlen);

	return mtu + x->props.header_len + esp->auth.icv_trunc_len;
}

static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                     int type, int code, int offset, __u32 info)
{
	struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
	struct ipv6_esp_hdr *esph = (struct ipv6_esp_hdr*)(skb->data+offset);
	struct xfrm_state *x;

	if (type != ICMPV6_DEST_UNREACH && 
	    type != ICMPV6_PKT_TOOBIG)
		return;

	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
	if (!x)
		return;
	printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
			"%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n", 
			ntohl(esph->spi), NIP6(iph->daddr));
	xfrm_state_put(x);
}

static void esp6_destroy(struct xfrm_state *x)
{
	struct esp_data *esp = x->data;

	if (!esp)
		return;

	crypto_free_tfm(esp->conf.tfm);
	esp->conf.tfm = NULL;
	kfree(esp->conf.ivec);
	esp->conf.ivec = NULL;
	crypto_free_tfm(esp->auth.tfm);
	esp->auth.tfm = NULL;
	kfree(esp->auth.work_icv);
	esp->auth.work_icv = NULL;
	kfree(esp);
}

static int esp6_init_state(struct xfrm_state *x)
{
	struct esp_data *esp = NULL;

	/* null auth and encryption can have zero length keys */
	if (x->aalg) {
		if (x->aalg->alg_key_len > 512)
			goto error;
	}
	if (x->ealg == NULL)
		goto error;

	if (x->encap)
		goto error;

	esp = kmalloc(sizeof(*esp), GFP_KERNEL);
	if (esp == NULL)
		return -ENOMEM;

	memset(esp, 0, sizeof(*esp));

	if (x->aalg) {
		struct xfrm_algo_desc *aalg_desc;

		esp->auth.key = x->aalg->alg_key;
		esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
		esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
		if (esp->auth.tfm == NULL)
			goto error;
		esp->auth.icv = esp_hmac_digest;
 
		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
		BUG_ON(!aalg_desc);
 
		if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
			crypto_tfm_alg_digestsize(esp->auth.tfm)) {
				printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
					x->aalg->alg_name,
					crypto_tfm_alg_digestsize(esp->auth.tfm),
					aalg_desc->uinfo.auth.icv_fullbits/8);
				goto error;
		}
 
		esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
		esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
 
		esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
		if (!esp->auth.work_icv)
			goto error;
	}
	esp->conf.key = x->ealg->alg_key;
	esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
	if (x->props.ealgo == SADB_EALG_NULL)
		esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
	else
		esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
	if (esp->conf.tfm == NULL)
		goto error;
	esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
	esp->conf.padlen = 0;
	if (esp->conf.ivlen) {
		esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
		if (unlikely(esp->conf.ivec == NULL))
			goto error;
		get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
	}
	if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
		goto error;
	x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
	if (x->props.mode)
		x->props.header_len += sizeof(struct ipv6hdr);
	x->data = esp;
	return 0;

error:
	x->data = esp;
	esp6_destroy(x);
	x->data = NULL;
	return -EINVAL;
}

static struct xfrm_type esp6_type =
{
	.description	= "ESP6",
	.owner	     	= THIS_MODULE,
	.proto	     	= IPPROTO_ESP,
	.init_state	= esp6_init_state,
	.destructor	= esp6_destroy,
	.get_max_size	= esp6_get_max_size,
	.input		= esp6_input,
	.output		= esp6_output
};

static struct inet6_protocol esp6_protocol = {
	.handler 	=	xfrm6_rcv,
	.err_handler	=	esp6_err,
	.flags		=	INET6_PROTO_NOPOLICY,
};

static int __init esp6_init(void)
{
	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
		printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
		return -EAGAIN;
	}
	if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
		printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
		xfrm_unregister_type(&esp6_type, AF_INET6);
		return -EAGAIN;
	}

	return 0;
}

static void __exit esp6_fini(void)
{
	if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
		printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
		printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
}

module_init(esp6_init);
module_exit(esp6_fini);

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C)2002 USAGI/WIDE Project
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*
	18	* Authors
	19	*
	20	* Mitsuru KANDA @USAGI : IPv6 Support
	21	* Kazunori MIYAZAWA @USAGI :
	22	* Kunihiro Ishiguro <kunihiro@ipinfusion.com>
	23	*
	24	* This file is derived from net/ipv4/esp.c
	25	*/
	26
	27	#include <linux/config.h>
	28	#include <linux/module.h>
	29	#include <net/ip.h>
	30	#include <net/xfrm.h>
	31	#include <net/esp.h>
	32	#include <asm/scatterlist.h>
	33	#include <linux/crypto.h>
a02a6422	34	#include <linux/kernel.h>
1da177e4 LT	35	#include <linux/pfkeyv2.h>
	36	#include <linux/random.h>
	37	#include <net/icmp.h>
	38	#include <net/ipv6.h>
	39	#include <linux/icmpv6.h>
	40
	41	static int esp6_output(struct xfrm_state x, struct sk_buff skb)
	42	{
	43	int err;
	44	int hdr_len;
	45	struct ipv6hdr *top_iph;
	46	struct ipv6_esp_hdr *esph;
	47	struct crypto_tfm *tfm;
	48	struct esp_data *esp;
	49	struct sk_buff *trailer;
	50	int blksize;
	51	int clen;
	52	int alen;
	53	int nfrags;
	54
	55	esp = x->data;
	56	hdr_len = skb->h.raw - skb->data +
	57	sizeof(*esph) + esp->conf.ivlen;
	58
	59	/* Strip IP+ESP header. */
	60	__skb_pull(skb, hdr_len);
	61
	62	/* Now skb is pure payload to encrypt */
	63	err = -ENOMEM;
	64
	65	/* Round to block size */
	66	clen = skb->len;
	67
	68	alen = esp->auth.icv_trunc_len;
	69	tfm = esp->conf.tfm;
a02a6422 HX	70	blksize = ALIGN(crypto_tfm_alg_blocksize(tfm), 4);
a02a6422 HX	71	clen = ALIGN(clen + 2, blksize);
1da177e4	72	if (esp->conf.padlen)
a02a6422	73	clen = ALIGN(clen, esp->conf.padlen);
1da177e4 LT	74
	75	if ((nfrags = skb_cow_data(skb, clen-skb->len+alen, &trailer)) < 0) {
	76	goto error;
	77	}
	78
	79	/* Fill padding... */
	80	do {
	81	int i;
	82	for (i=0; i<clen-skb->len - 2; i++)
	83	(u8)(trailer->tail + i) = i+1;
	84	} while (0);
	85	(u8)(trailer->tail + clen-skb->len - 2) = (clen - skb->len)-2;
	86	pskb_put(skb, trailer, clen - skb->len);
	87
	88	top_iph = (struct ipv6hdr *)__skb_push(skb, hdr_len);
	89	esph = (struct ipv6_esp_hdr *)skb->h.raw;
	90	top_iph->payload_len = htons(skb->len + alen - sizeof(*top_iph));
	91	(u8)(trailer->tail - 1) = *skb->nh.raw;
	92	*skb->nh.raw = IPPROTO_ESP;
	93
	94	esph->spi = x->id.spi;
	95	esph->seq_no = htonl(++x->replay.oseq);
	96
	97	if (esp->conf.ivlen)
	98	crypto_cipher_set_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
	99
	100	do {
	101	struct scatterlist *sg = &esp->sgbuf[0];
	102
	103	if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
	104	sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
	105	if (!sg)
	106	goto error;
	107	}
	108	skb_to_sgvec(skb, sg, esph->enc_data+esp->conf.ivlen-skb->data, clen);
	109	crypto_cipher_encrypt(tfm, sg, sg, clen);
	110	if (unlikely(sg != &esp->sgbuf[0]))
	111	kfree(sg);
	112	} while (0);
	113
	114	if (esp->conf.ivlen) {
	115	memcpy(esph->enc_data, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
	116	crypto_cipher_get_iv(tfm, esp->conf.ivec, crypto_tfm_alg_ivsize(tfm));
	117	}
	118
	119	if (esp->auth.icv_full_len) {
	120	esp->auth.icv(esp, skb, (u8*)esph-skb->data,
	121	sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen+clen, trailer->tail);
	122	pskb_put(skb, trailer, alen);
	123	}
	124
	125	err = 0;
	126
	127	error:
	128	return err;
	129	}
	130
	131	static int esp6_input(struct xfrm_state x, struct xfrm_decap_state decap, struct sk_buff *skb)
	132	{
	133	struct ipv6hdr *iph;
	134	struct ipv6_esp_hdr *esph;
	135	struct esp_data *esp = x->data;
	136	struct sk_buff *trailer;
d4875b04	137	int blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
1da177e4 LT	138	int alen = esp->auth.icv_trunc_len;
	139	int elen = skb->len - sizeof(struct ipv6_esp_hdr) - esp->conf.ivlen - alen;
	140
	141	int hdr_len = skb->h.raw - skb->nh.raw;
	142	int nfrags;
	143	unsigned char *tmp_hdr = NULL;
	144	int ret = 0;
	145
	146	if (!pskb_may_pull(skb, sizeof(struct ipv6_esp_hdr))) {
	147	ret = -EINVAL;
	148	goto out_nofree;
	149	}
	150
	151	if (elen <= 0 \|\| (elen & (blksize-1))) {
	152	ret = -EINVAL;
	153	goto out_nofree;
	154	}
	155
	156	tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
	157	if (!tmp_hdr) {
	158	ret = -ENOMEM;
	159	goto out_nofree;
	160	}
	161	memcpy(tmp_hdr, skb->nh.raw, hdr_len);
	162
	163	/* If integrity check is required, do this. */
	164	if (esp->auth.icv_full_len) {
	165	u8 sum[esp->auth.icv_full_len];
	166	u8 sum1[alen];
	167
	168	esp->auth.icv(esp, skb, 0, skb->len-alen, sum);
	169
	170	if (skb_copy_bits(skb, skb->len-alen, sum1, alen))
	171	BUG();
	172
	173	if (unlikely(memcmp(sum, sum1, alen))) {
	174	x->stats.integrity_failed++;
	175	ret = -EINVAL;
	176	goto out;
	177	}
	178	}
	179
	180	if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
	181	ret = -EINVAL;
	182	goto out;
	183	}
	184
	185	skb->ip_summed = CHECKSUM_NONE;
	186
	187	esph = (struct ipv6_esp_hdr*)skb->data;
	188	iph = skb->nh.ipv6h;
	189
	190	/* Get ivec. This can be wrong, check against another impls. */
	191	if (esp->conf.ivlen)
	192	crypto_cipher_set_iv(esp->conf.tfm, esph->enc_data, crypto_tfm_alg_ivsize(esp->conf.tfm));
	193
	194	{
	195	u8 nexthdr[2];
	196	struct scatterlist *sg = &esp->sgbuf[0];
	197	u8 padlen;
	198
	199	if (unlikely(nfrags > ESP_NUM_FAST_SG)) {
	200	sg = kmalloc(sizeof(struct scatterlist)*nfrags, GFP_ATOMIC);
	201	if (!sg) {
202	ret = -ENOMEM;
203	goto out;
204	}
205	}
206	skb_to_sgvec(skb, sg, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen, elen);
207	crypto_cipher_decrypt(esp->conf.tfm, sg, sg, elen);
208	if (unlikely(sg != &esp->sgbuf[0]))
209	kfree(sg);
210
211	if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
212	BUG();
213
214	padlen = nexthdr[0];
215	if (padlen+2 >= elen) {
64ce2073	216	LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen+2, elen);
1da177e4 LT	217	ret = -EINVAL;
	218	goto out;
	219	}
	220	/* ... check padding bits here. Silly. :-) */
	221
	222	pskb_trim(skb, skb->len - alen - padlen - 2);
	223	skb->h.raw = skb_pull(skb, sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen);
	224	skb->nh.raw += sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
	225	memcpy(skb->nh.raw, tmp_hdr, hdr_len);
	226	skb->nh.ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	227	ret = nexthdr[1];
	228	}
	229
	230	out:
	231	kfree(tmp_hdr);
	232	out_nofree:
	233	return ret;
	234	}
	235
	236	static u32 esp6_get_max_size(struct xfrm_state *x, int mtu)
	237	{
	238	struct esp_data *esp = x->data;
d4875b04	239	u32 blksize = ALIGN(crypto_tfm_alg_blocksize(esp->conf.tfm), 4);
1da177e4 LT	240
1da177e4 LT	241	if (x->props.mode) {
a02a6422	242	mtu = ALIGN(mtu + 2, blksize);
1da177e4 LT	243	} else {
1da177e4 LT	244	/* The worst case. */
d4875b04 HX	245	u32 padsize = ((blksize - 1) & 7) + 1;
d4875b04 HX	246	mtu = ALIGN(mtu + 2, padsize) + blksize - padsize;
1da177e4 LT	247	}
1da177e4 LT	248	if (esp->conf.padlen)
a02a6422	249	mtu = ALIGN(mtu, esp->conf.padlen);
1da177e4	250
73d4f84f	251	return mtu + x->props.header_len + esp->auth.icv_trunc_len;
1da177e4 LT	252	}
	253
	254	static void esp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
	255	int type, int code, int offset, __u32 info)
	256	{
	257	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
	258	struct ipv6_esp_hdr esph = (struct ipv6_esp_hdr)(skb->data+offset);
	259	struct xfrm_state *x;
	260
	261	if (type != ICMPV6_DEST_UNREACH &&
	262	type != ICMPV6_PKT_TOOBIG)
	263	return;
	264
	265	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, esph->spi, IPPROTO_ESP, AF_INET6);
	266	if (!x)
	267	return;
	268	printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/"
	269	"%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
	270	ntohl(esph->spi), NIP6(iph->daddr));
	271	xfrm_state_put(x);
	272	}
	273
	274	static void esp6_destroy(struct xfrm_state *x)
	275	{
	276	struct esp_data *esp = x->data;
	277
	278	if (!esp)
	279	return;
	280
573dbd95 JJ	281	crypto_free_tfm(esp->conf.tfm);
	282	esp->conf.tfm = NULL;
	283	kfree(esp->conf.ivec);
	284	esp->conf.ivec = NULL;
	285	crypto_free_tfm(esp->auth.tfm);
	286	esp->auth.tfm = NULL;
	287	kfree(esp->auth.work_icv);
	288	esp->auth.work_icv = NULL;
1da177e4 LT	289	kfree(esp);
	290	}
	291
72cb6962	292	static int esp6_init_state(struct xfrm_state *x)
1da177e4 LT	293	{
	294	struct esp_data *esp = NULL;
	295
	296	/* null auth and encryption can have zero length keys */
	297	if (x->aalg) {
	298	if (x->aalg->alg_key_len > 512)
	299	goto error;
	300	}
	301	if (x->ealg == NULL)
	302	goto error;
	303
	304	if (x->encap)
	305	goto error;
	306
	307	esp = kmalloc(sizeof(*esp), GFP_KERNEL);
	308	if (esp == NULL)
	309	return -ENOMEM;
	310
	311	memset(esp, 0, sizeof(*esp));
	312
	313	if (x->aalg) {
	314	struct xfrm_algo_desc *aalg_desc;
	315
	316	esp->auth.key = x->aalg->alg_key;
	317	esp->auth.key_len = (x->aalg->alg_key_len+7)/8;
	318	esp->auth.tfm = crypto_alloc_tfm(x->aalg->alg_name, 0);
	319	if (esp->auth.tfm == NULL)
	320	goto error;
	321	esp->auth.icv = esp_hmac_digest;
	322
	323	aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
	324	BUG_ON(!aalg_desc);
	325
	326	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
	327	crypto_tfm_alg_digestsize(esp->auth.tfm)) {
	328	printk(KERN_INFO "ESP: %s digestsize %u != %hu\n",
	329	x->aalg->alg_name,
	330	crypto_tfm_alg_digestsize(esp->auth.tfm),
	331	aalg_desc->uinfo.auth.icv_fullbits/8);
	332	goto error;
	333	}
	334
	335	esp->auth.icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
	336	esp->auth.icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
	337
	338	esp->auth.work_icv = kmalloc(esp->auth.icv_full_len, GFP_KERNEL);
	339	if (!esp->auth.work_icv)
	340	goto error;
	341	}
	342	esp->conf.key = x->ealg->alg_key;
	343	esp->conf.key_len = (x->ealg->alg_key_len+7)/8;
	344	if (x->props.ealgo == SADB_EALG_NULL)
	345	esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_ECB);
	346	else
	347	esp->conf.tfm = crypto_alloc_tfm(x->ealg->alg_name, CRYPTO_TFM_MODE_CBC);
	348	if (esp->conf.tfm == NULL)
	349	goto error;
	350	esp->conf.ivlen = crypto_tfm_alg_ivsize(esp->conf.tfm);
	351	esp->conf.padlen = 0;
	352	if (esp->conf.ivlen) {
	353	esp->conf.ivec = kmalloc(esp->conf.ivlen, GFP_KERNEL);
	354	if (unlikely(esp->conf.ivec == NULL))
	355	goto error;
	356	get_random_bytes(esp->conf.ivec, esp->conf.ivlen);
357	}
358	if (crypto_cipher_setkey(esp->conf.tfm, esp->conf.key, esp->conf.key_len))
359	goto error;
360	x->props.header_len = sizeof(struct ipv6_esp_hdr) + esp->conf.ivlen;
361	if (x->props.mode)
362	x->props.header_len += sizeof(struct ipv6hdr);
363	x->data = esp;
364	return 0;
365
366	error:
367	x->data = esp;
368	esp6_destroy(x);
369	x->data = NULL;
370	return -EINVAL;
371	}
372
373	static struct xfrm_type esp6_type =
374	{
375	.description = "ESP6",
376	.owner = THIS_MODULE,
377	.proto = IPPROTO_ESP,
378	.init_state = esp6_init_state,
379	.destructor = esp6_destroy,
380	.get_max_size = esp6_get_max_size,
381	.input = esp6_input,
382	.output = esp6_output
383	};
384
385	static struct inet6_protocol esp6_protocol = {
386	.handler = xfrm6_rcv,
387	.err_handler = esp6_err,
388	.flags = INET6_PROTO_NOPOLICY,
389	};
390
391	static int __init esp6_init(void)
392	{
393	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
394	printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
395	return -EAGAIN;
396	}
397	if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
398	printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
399	xfrm_unregister_type(&esp6_type, AF_INET6);
400	return -EAGAIN;
401	}
402
403	return 0;
404	}
405
406	static void __exit esp6_fini(void)
407	{
408	if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
409	printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
410	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
411	printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
412	}
413
414	module_init(esp6_init);
415	module_exit(esp6_fini);
416
417	MODULE_LICENSE("GPL");