2 * Copyright (C)2002 USAGI/WIDE Project
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.
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.
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
20 * Mitsuru KANDA @USAGI : IPv6 Support
21 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
24 * This file is derived from net/ipv4/esp.c
27 #include <linux/err.h>
28 #include <linux/module.h>
32 #include <asm/scatterlist.h>
33 #include <linux/crypto.h>
34 #include <linux/kernel.h>
35 #include <linux/pfkeyv2.h>
36 #include <linux/random.h>
39 #include <net/protocol.h>
40 #include <linux/icmpv6.h>
42 static int esp6_output(struct xfrm_state
*x
, struct sk_buff
*skb
)
46 struct ipv6hdr
*top_iph
;
47 struct ipv6_esp_hdr
*esph
;
48 struct crypto_blkcipher
*tfm
;
49 struct blkcipher_desc desc
;
51 struct sk_buff
*trailer
;
58 hdr_len
= skb
->h
.raw
- skb
->data
+
59 sizeof(*esph
) + esp
->conf
.ivlen
;
61 /* Strip IP+ESP header. */
62 __skb_pull(skb
, hdr_len
);
64 /* Now skb is pure payload to encrypt */
67 /* Round to block size */
70 alen
= esp
->auth
.icv_trunc_len
;
74 blksize
= ALIGN(crypto_blkcipher_blocksize(tfm
), 4);
75 clen
= ALIGN(clen
+ 2, blksize
);
77 clen
= ALIGN(clen
, esp
->conf
.padlen
);
79 if ((nfrags
= skb_cow_data(skb
, clen
-skb
->len
+alen
, &trailer
)) < 0) {
86 for (i
=0; i
<clen
-skb
->len
- 2; i
++)
87 *(u8
*)(trailer
->tail
+ i
) = i
+1;
89 *(u8
*)(trailer
->tail
+ clen
-skb
->len
- 2) = (clen
- skb
->len
)-2;
90 pskb_put(skb
, trailer
, clen
- skb
->len
);
92 top_iph
= (struct ipv6hdr
*)__skb_push(skb
, hdr_len
);
93 esph
= (struct ipv6_esp_hdr
*)skb
->h
.raw
;
94 top_iph
->payload_len
= htons(skb
->len
+ alen
- sizeof(*top_iph
));
95 *(u8
*)(trailer
->tail
- 1) = *skb
->nh
.raw
;
96 *skb
->nh
.raw
= IPPROTO_ESP
;
98 esph
->spi
= x
->id
.spi
;
99 esph
->seq_no
= htonl(++x
->replay
.oseq
);
100 xfrm_aevent_doreplay(x
);
103 crypto_blkcipher_set_iv(tfm
, esp
->conf
.ivec
, esp
->conf
.ivlen
);
106 struct scatterlist
*sg
= &esp
->sgbuf
[0];
108 if (unlikely(nfrags
> ESP_NUM_FAST_SG
)) {
109 sg
= kmalloc(sizeof(struct scatterlist
)*nfrags
, GFP_ATOMIC
);
113 skb_to_sgvec(skb
, sg
, esph
->enc_data
+esp
->conf
.ivlen
-skb
->data
, clen
);
114 err
= crypto_blkcipher_encrypt(&desc
, sg
, sg
, clen
);
115 if (unlikely(sg
!= &esp
->sgbuf
[0]))
122 if (esp
->conf
.ivlen
) {
123 memcpy(esph
->enc_data
, esp
->conf
.ivec
, esp
->conf
.ivlen
);
124 crypto_blkcipher_get_iv(tfm
, esp
->conf
.ivec
, esp
->conf
.ivlen
);
127 if (esp
->auth
.icv_full_len
) {
128 err
= esp_mac_digest(esp
, skb
, (u8
*)esph
- skb
->data
,
129 sizeof(*esph
) + esp
->conf
.ivlen
+ clen
);
130 memcpy(pskb_put(skb
, trailer
, alen
), esp
->auth
.work_icv
, alen
);
137 static int esp6_input(struct xfrm_state
*x
, struct sk_buff
*skb
)
140 struct ipv6_esp_hdr
*esph
;
141 struct esp_data
*esp
= x
->data
;
142 struct crypto_blkcipher
*tfm
= esp
->conf
.tfm
;
143 struct blkcipher_desc desc
= { .tfm
= tfm
};
144 struct sk_buff
*trailer
;
145 int blksize
= ALIGN(crypto_blkcipher_blocksize(tfm
), 4);
146 int alen
= esp
->auth
.icv_trunc_len
;
147 int elen
= skb
->len
- sizeof(struct ipv6_esp_hdr
) - esp
->conf
.ivlen
- alen
;
149 int hdr_len
= skb
->h
.raw
- skb
->nh
.raw
;
153 if (!pskb_may_pull(skb
, sizeof(struct ipv6_esp_hdr
))) {
158 if (elen
<= 0 || (elen
& (blksize
-1))) {
163 /* If integrity check is required, do this. */
164 if (esp
->auth
.icv_full_len
) {
167 ret
= esp_mac_digest(esp
, skb
, 0, skb
->len
- alen
);
171 if (skb_copy_bits(skb
, skb
->len
- alen
, sum
, alen
))
174 if (unlikely(memcmp(esp
->auth
.work_icv
, sum
, alen
))) {
175 x
->stats
.integrity_failed
++;
181 if ((nfrags
= skb_cow_data(skb
, 0, &trailer
)) < 0) {
186 skb
->ip_summed
= CHECKSUM_NONE
;
188 esph
= (struct ipv6_esp_hdr
*)skb
->data
;
191 /* Get ivec. This can be wrong, check against another impls. */
193 crypto_blkcipher_set_iv(tfm
, esph
->enc_data
, esp
->conf
.ivlen
);
197 struct scatterlist
*sg
= &esp
->sgbuf
[0];
200 if (unlikely(nfrags
> ESP_NUM_FAST_SG
)) {
201 sg
= kmalloc(sizeof(struct scatterlist
)*nfrags
, GFP_ATOMIC
);
207 skb_to_sgvec(skb
, sg
, sizeof(struct ipv6_esp_hdr
) + esp
->conf
.ivlen
, elen
);
208 ret
= crypto_blkcipher_decrypt(&desc
, sg
, sg
, elen
);
209 if (unlikely(sg
!= &esp
->sgbuf
[0]))
214 if (skb_copy_bits(skb
, skb
->len
-alen
-2, nexthdr
, 2))
218 if (padlen
+2 >= elen
) {
219 LIMIT_NETDEBUG(KERN_WARNING
"ipsec esp packet is garbage padlen=%d, elen=%d\n", padlen
+2, elen
);
223 /* ... check padding bits here. Silly. :-) */
225 pskb_trim(skb
, skb
->len
- alen
- padlen
- 2);
229 skb
->h
.raw
= __skb_pull(skb
, sizeof(*esph
) + esp
->conf
.ivlen
) - hdr_len
;
235 static u32
esp6_get_max_size(struct xfrm_state
*x
, int mtu
)
237 struct esp_data
*esp
= x
->data
;
238 u32 blksize
= ALIGN(crypto_blkcipher_blocksize(esp
->conf
.tfm
), 4);
241 mtu
= ALIGN(mtu
+ 2, blksize
);
243 /* The worst case. */
244 u32 padsize
= ((blksize
- 1) & 7) + 1;
245 mtu
= ALIGN(mtu
+ 2, padsize
) + blksize
- padsize
;
247 if (esp
->conf
.padlen
)
248 mtu
= ALIGN(mtu
, esp
->conf
.padlen
);
250 return mtu
+ x
->props
.header_len
+ esp
->auth
.icv_trunc_len
;
253 static void esp6_err(struct sk_buff
*skb
, struct inet6_skb_parm
*opt
,
254 int type
, int code
, int offset
, __u32 info
)
256 struct ipv6hdr
*iph
= (struct ipv6hdr
*)skb
->data
;
257 struct ipv6_esp_hdr
*esph
= (struct ipv6_esp_hdr
*)(skb
->data
+offset
);
258 struct xfrm_state
*x
;
260 if (type
!= ICMPV6_DEST_UNREACH
&&
261 type
!= ICMPV6_PKT_TOOBIG
)
264 x
= xfrm_state_lookup((xfrm_address_t
*)&iph
->daddr
, esph
->spi
, IPPROTO_ESP
, AF_INET6
);
267 printk(KERN_DEBUG
"pmtu discovery on SA ESP/%08x/" NIP6_FMT
"\n",
268 ntohl(esph
->spi
), NIP6(iph
->daddr
));
272 static void esp6_destroy(struct xfrm_state
*x
)
274 struct esp_data
*esp
= x
->data
;
279 crypto_free_blkcipher(esp
->conf
.tfm
);
280 esp
->conf
.tfm
= NULL
;
281 kfree(esp
->conf
.ivec
);
282 esp
->conf
.ivec
= NULL
;
283 crypto_free_hash(esp
->auth
.tfm
);
284 esp
->auth
.tfm
= NULL
;
285 kfree(esp
->auth
.work_icv
);
286 esp
->auth
.work_icv
= NULL
;
290 static int esp6_init_state(struct xfrm_state
*x
)
292 struct esp_data
*esp
= NULL
;
293 struct crypto_blkcipher
*tfm
;
295 /* null auth and encryption can have zero length keys */
297 if (x
->aalg
->alg_key_len
> 512)
306 esp
= kzalloc(sizeof(*esp
), GFP_KERNEL
);
311 struct xfrm_algo_desc
*aalg_desc
;
312 struct crypto_hash
*hash
;
314 esp
->auth
.key
= x
->aalg
->alg_key
;
315 esp
->auth
.key_len
= (x
->aalg
->alg_key_len
+7)/8;
316 hash
= crypto_alloc_hash(x
->aalg
->alg_name
, 0,
321 esp
->auth
.tfm
= hash
;
322 if (crypto_hash_setkey(hash
, esp
->auth
.key
, esp
->auth
.key_len
))
325 aalg_desc
= xfrm_aalg_get_byname(x
->aalg
->alg_name
, 0);
328 if (aalg_desc
->uinfo
.auth
.icv_fullbits
/8 !=
329 crypto_hash_digestsize(hash
)) {
330 NETDEBUG(KERN_INFO
"ESP: %s digestsize %u != %hu\n",
332 crypto_hash_digestsize(hash
),
333 aalg_desc
->uinfo
.auth
.icv_fullbits
/8);
337 esp
->auth
.icv_full_len
= aalg_desc
->uinfo
.auth
.icv_fullbits
/8;
338 esp
->auth
.icv_trunc_len
= aalg_desc
->uinfo
.auth
.icv_truncbits
/8;
340 esp
->auth
.work_icv
= kmalloc(esp
->auth
.icv_full_len
, GFP_KERNEL
);
341 if (!esp
->auth
.work_icv
)
344 esp
->conf
.key
= x
->ealg
->alg_key
;
345 esp
->conf
.key_len
= (x
->ealg
->alg_key_len
+7)/8;
346 tfm
= crypto_alloc_blkcipher(x
->ealg
->alg_name
, 0, CRYPTO_ALG_ASYNC
);
350 esp
->conf
.ivlen
= crypto_blkcipher_ivsize(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
))
356 get_random_bytes(esp
->conf
.ivec
, esp
->conf
.ivlen
);
358 if (crypto_blkcipher_setkey(tfm
, esp
->conf
.key
, esp
->conf
.key_len
))
360 x
->props
.header_len
= sizeof(struct ipv6_esp_hdr
) + esp
->conf
.ivlen
;
362 x
->props
.header_len
+= sizeof(struct ipv6hdr
);
373 static struct xfrm_type esp6_type
=
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
,
382 .output
= esp6_output
385 static struct inet6_protocol esp6_protocol
= {
386 .handler
= xfrm6_rcv
,
387 .err_handler
= esp6_err
,
388 .flags
= INET6_PROTO_NOPOLICY
,
391 static int __init
esp6_init(void)
393 if (xfrm_register_type(&esp6_type
, AF_INET6
) < 0) {
394 printk(KERN_INFO
"ipv6 esp init: can't add xfrm type\n");
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
);
406 static void __exit
esp6_fini(void)
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");
414 module_init(esp6_init
);
415 module_exit(esp6_fini
);
417 MODULE_LICENSE("GPL");