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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C)2002 USAGI/WIDE Project
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090013 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 * 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 *
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090020 * Mitsuru KANDA @USAGI : IPv6 Support
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090023 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * This file is derived from net/ipv4/esp.c
25 */
26
Joe Perchesf3213832012-05-15 14:11:53 +000027#define pr_fmt(fmt) "IPv6: " fmt
28
Herbert Xu38320c72008-01-28 19:35:05 -080029#include <crypto/aead.h>
30#include <crypto/authenc.h>
Herbert Xu6b7326c2006-07-30 15:41:01 +100031#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/module.h>
33#include <net/ip.h>
34#include <net/xfrm.h>
35#include <net/esp.h>
Adrian Bunk72998d82007-10-26 22:53:58 -070036#include <linux/scatterlist.h>
Herbert Xua02a6422005-10-10 21:11:08 -070037#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <linux/pfkeyv2.h>
39#include <linux/random.h>
Herbert Xu38320c72008-01-28 19:35:05 -080040#include <linux/slab.h>
Herbert Xub7c65382007-10-09 13:33:35 -070041#include <linux/spinlock.h>
David S. Miller81aded22012-06-15 14:54:11 -070042#include <net/ip6_route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <net/icmp.h>
44#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020045#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/icmpv6.h>
47
Herbert Xu38320c72008-01-28 19:35:05 -080048struct esp_skb_cb {
49 struct xfrm_skb_cb xfrm;
50 void *tmp;
51};
52
53#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
54
Martin Willi040253c2010-12-08 04:37:51 +000055static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
56
Herbert Xu38320c72008-01-28 19:35:05 -080057/*
58 * Allocate an AEAD request structure with extra space for SG and IV.
59 *
Steffen Klassertd212a4c2011-03-08 00:07:51 +000060 * For alignment considerations the upper 32 bits of the sequence number are
61 * placed at the front, if present. Followed by the IV, the request and finally
62 * the SG list.
Herbert Xu38320c72008-01-28 19:35:05 -080063 *
64 * TODO: Use spare space in skb for this where possible.
65 */
Steffen Klassertd212a4c2011-03-08 00:07:51 +000066static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
Herbert Xu38320c72008-01-28 19:35:05 -080067{
68 unsigned int len;
69
Steffen Klassertd212a4c2011-03-08 00:07:51 +000070 len = seqihlen;
71
72 len += crypto_aead_ivsize(aead);
73
Herbert Xu38320c72008-01-28 19:35:05 -080074 if (len) {
75 len += crypto_aead_alignmask(aead) &
76 ~(crypto_tfm_ctx_alignment() - 1);
77 len = ALIGN(len, crypto_tfm_ctx_alignment());
78 }
79
80 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
81 len = ALIGN(len, __alignof__(struct scatterlist));
82
83 len += sizeof(struct scatterlist) * nfrags;
84
85 return kmalloc(len, GFP_ATOMIC);
86}
87
Steffen Klassertd212a4c2011-03-08 00:07:51 +000088static inline __be32 *esp_tmp_seqhi(void *tmp)
89{
90 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
91}
92
93static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080094{
95 return crypto_aead_ivsize(aead) ?
Steffen Klassertd212a4c2011-03-08 00:07:51 +000096 PTR_ALIGN((u8 *)tmp + seqhilen,
97 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -080098}
99
100static inline struct aead_givcrypt_request *esp_tmp_givreq(
101 struct crypto_aead *aead, u8 *iv)
102{
103 struct aead_givcrypt_request *req;
104
105 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
106 crypto_tfm_ctx_alignment());
107 aead_givcrypt_set_tfm(req, aead);
108 return req;
109}
110
111static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
112{
113 struct aead_request *req;
114
115 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
116 crypto_tfm_ctx_alignment());
117 aead_request_set_tfm(req, aead);
118 return req;
119}
120
121static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
122 struct aead_request *req)
123{
124 return (void *)ALIGN((unsigned long)(req + 1) +
125 crypto_aead_reqsize(aead),
126 __alignof__(struct scatterlist));
127}
128
129static inline struct scatterlist *esp_givreq_sg(
130 struct crypto_aead *aead, struct aead_givcrypt_request *req)
131{
132 return (void *)ALIGN((unsigned long)(req + 1) +
133 crypto_aead_reqsize(aead),
134 __alignof__(struct scatterlist));
135}
136
137static void esp_output_done(struct crypto_async_request *base, int err)
138{
139 struct sk_buff *skb = base->data;
140
141 kfree(ESP_SKB_CB(skb)->tmp);
142 xfrm_output_resume(skb, err);
143}
144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
146{
147 int err;
Herbert Xu87bdc482007-10-10 15:45:25 -0700148 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800149 struct crypto_aead *aead;
150 struct aead_givcrypt_request *req;
151 struct scatterlist *sg;
152 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800154 void *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 int blksize;
156 int clen;
157 int alen;
Martin Willi040253c2010-12-08 04:37:51 +0000158 int plen;
159 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000161 int assoclen;
162 int sglists;
163 int seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -0800164 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700165 u8 *tail;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000166 __be32 *seqhi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Herbert Xu7b277b12007-10-10 15:44:06 -0700168 /* skb is pure payload to encrypt */
Mathias Krause1c5ad132013-10-18 12:09:05 +0200169 aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800170 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Martin Willi040253c2010-12-08 04:37:51 +0000172 tfclen = 0;
173 if (x->tfcpad) {
174 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
175 u32 padto;
176
177 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
178 if (skb->len < padto)
179 tfclen = padto - skb->len;
180 }
Herbert Xu38320c72008-01-28 19:35:05 -0800181 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willi040253c2010-12-08 04:37:51 +0000182 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Martin Willi040253c2010-12-08 04:37:51 +0000183 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800184
Martin Willi040253c2010-12-08 04:37:51 +0000185 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
186 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800188 nfrags = err;
189
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000190 assoclen = sizeof(*esph);
191 sglists = 1;
192 seqhilen = 0;
193
194 if (x->props.flags & XFRM_STATE_ESN) {
195 sglists += 2;
196 seqhilen += sizeof(__be32);
197 assoclen += seqhilen;
198 }
199
200 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Julia Lawall48f125c2012-08-29 06:49:12 +0000201 if (!tmp) {
202 err = -ENOMEM;
Herbert Xu38320c72008-01-28 19:35:05 -0800203 goto error;
Julia Lawall48f125c2012-08-29 06:49:12 +0000204 }
Herbert Xu38320c72008-01-28 19:35:05 -0800205
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000206 seqhi = esp_tmp_seqhi(tmp);
207 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800208 req = esp_tmp_givreq(aead, iv);
209 asg = esp_givreq_sg(aead, req);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000210 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700213 tail = skb_tail_pointer(trailer);
Martin Willi040253c2010-12-08 04:37:51 +0000214 if (tfclen) {
215 memset(tail, 0, tfclen);
216 tail += tfclen;
217 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 do {
219 int i;
Martin Willi040253c2010-12-08 04:37:51 +0000220 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700221 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 } while (0);
Martin Willi040253c2010-12-08 04:37:51 +0000223 tail[plen - 2] = plen - 2;
224 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800225 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Herbert Xu7b277b12007-10-10 15:44:06 -0700227 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700228 esph = ip_esp_hdr(skb);
Herbert Xu007f0212007-10-09 13:25:59 -0700229 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
231 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000232 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Herbert Xu38320c72008-01-28 19:35:05 -0800234 sg_init_table(sg, nfrags);
235 skb_to_sgvec(skb, sg,
236 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
237 clen + alen);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000238
239 if ((x->props.flags & XFRM_STATE_ESN)) {
240 sg_init_table(asg, 3);
241 sg_set_buf(asg, &esph->spi, sizeof(__be32));
242 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
243 sg_set_buf(asg + 1, seqhi, seqhilen);
244 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
245 } else
246 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xub7c65382007-10-09 13:33:35 -0700247
Herbert Xu38320c72008-01-28 19:35:05 -0800248 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
249 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000250 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800251 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000252 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253
Herbert Xu38320c72008-01-28 19:35:05 -0800254 ESP_SKB_CB(skb)->tmp = tmp;
255 err = crypto_aead_givencrypt(req);
256 if (err == -EINPROGRESS)
257 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
Herbert Xu38320c72008-01-28 19:35:05 -0800259 if (err == -EBUSY)
260 err = NET_XMIT_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
Herbert Xu38320c72008-01-28 19:35:05 -0800262 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700263
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264error:
265 return err;
266}
267
Herbert Xu38320c72008-01-28 19:35:05 -0800268static int esp_input_done2(struct sk_buff *skb, int err)
269{
270 struct xfrm_state *x = xfrm_input_state(skb);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200271 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800272 int alen = crypto_aead_authsize(aead);
273 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
274 int elen = skb->len - hlen;
275 int hdr_len = skb_network_header_len(skb);
276 int padlen;
277 u8 nexthdr[2];
278
279 kfree(ESP_SKB_CB(skb)->tmp);
280
281 if (unlikely(err))
282 goto out;
283
284 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
285 BUG();
286
287 err = -EINVAL;
288 padlen = nexthdr[0];
289 if (padlen + 2 + alen >= elen) {
290 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
291 "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
292 goto out;
293 }
294
295 /* ... check padding bits here. Silly. :-) */
296
297 pskb_trim(skb, skb->len - alen - padlen - 2);
298 __skb_pull(skb, hlen);
Li RongQinga9403f82013-01-08 15:41:12 +0800299 if (x->props.mode == XFRM_MODE_TUNNEL)
300 skb_reset_transport_header(skb);
301 else
302 skb_set_transport_header(skb, -hdr_len);
Herbert Xu38320c72008-01-28 19:35:05 -0800303
304 err = nexthdr[1];
305
306 /* RFC4303: Drop dummy packets without any error */
307 if (err == IPPROTO_NONE)
308 err = -EINVAL;
309
310out:
311 return err;
312}
313
314static void esp_input_done(struct crypto_async_request *base, int err)
315{
316 struct sk_buff *skb = base->data;
317
318 xfrm_input_resume(skb, esp_input_done2(skb, err));
319}
320
Herbert Xue6956332006-04-01 00:52:46 -0800321static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322{
Herbert Xu87bdc482007-10-10 15:45:25 -0700323 struct ip_esp_hdr *esph;
Mathias Krause1c5ad132013-10-18 12:09:05 +0200324 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800325 struct aead_request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800327 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000329 int assoclen;
330 int sglists;
331 int seqhilen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 int ret = 0;
Herbert Xu38320c72008-01-28 19:35:05 -0800333 void *tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000334 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800335 u8 *iv;
336 struct scatterlist *sg;
337 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Thomas Graf920fc942008-03-27 16:08:03 -0700339 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700341 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 }
343
Herbert Xu38320c72008-01-28 19:35:05 -0800344 if (elen <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700346 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 }
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
350 ret = -EINVAL;
351 goto out;
352 }
353
Herbert Xu38320c72008-01-28 19:35:05 -0800354 ret = -ENOMEM;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000355
356 assoclen = sizeof(*esph);
357 sglists = 1;
358 seqhilen = 0;
359
360 if (x->props.flags & XFRM_STATE_ESN) {
361 sglists += 2;
362 seqhilen += sizeof(__be32);
363 assoclen += seqhilen;
364 }
365
366 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800367 if (!tmp)
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800368 goto out;
369
Herbert Xu38320c72008-01-28 19:35:05 -0800370 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000371 seqhi = esp_tmp_seqhi(tmp);
372 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800373 req = esp_tmp_req(aead, iv);
374 asg = esp_req_sg(aead, req);
Steffen Klassertc0a56e62011-04-25 19:40:23 +0000375 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
Herbert Xu38320c72008-01-28 19:35:05 -0800377 skb->ip_summed = CHECKSUM_NONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
Herbert Xu38320c72008-01-28 19:35:05 -0800379 esph = (struct ip_esp_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Herbert Xu38320c72008-01-28 19:35:05 -0800381 /* Get ivec. This can be wrong, check against another impls. */
382 iv = esph->enc_data;
Thomas Graf95a02cf2007-12-10 16:53:29 -0800383
Herbert Xu38320c72008-01-28 19:35:05 -0800384 sg_init_table(sg, nfrags);
385 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000386
387 if ((x->props.flags & XFRM_STATE_ESN)) {
388 sg_init_table(asg, 3);
389 sg_set_buf(asg, &esph->spi, sizeof(__be32));
390 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
391 sg_set_buf(asg + 1, seqhi, seqhilen);
392 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
393 } else
394 sg_init_one(asg, esph, sizeof(*esph));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
Herbert Xu38320c72008-01-28 19:35:05 -0800396 aead_request_set_callback(req, 0, esp_input_done, skb);
397 aead_request_set_crypt(req, sg, sg, elen, iv);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000398 aead_request_set_assoc(req, asg, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800399
400 ret = crypto_aead_decrypt(req);
401 if (ret == -EINPROGRESS)
402 goto out;
403
404 ret = esp_input_done2(skb, ret);
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 return ret;
408}
409
Patrick McHardyc5c25232007-04-09 11:47:18 -0700410static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200412 struct crypto_aead *aead = x->data;
413 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000414 unsigned int net_adj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000416 if (x->props.mode != XFRM_MODE_TUNNEL)
417 net_adj = sizeof(struct ipv6hdr);
418 else
419 net_adj = 0;
Patrick McHardyc5c25232007-04-09 11:47:18 -0700420
Mathias Krause1c5ad132013-10-18 12:09:05 +0200421 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
Mathias Krause123b0d12013-10-18 12:09:04 +0200422 net_adj) & ~(blksize - 1)) + net_adj - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423}
424
425static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
Brian Haleyd5fdd6b2009-06-23 04:31:07 -0700426 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800428 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000429 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
Herbert Xu87bdc482007-10-10 15:45:25 -0700430 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 struct xfrm_state *x;
432
Steffen Klassertb3b2b9e2013-09-10 13:43:09 +0200433 if (type != ICMPV6_PKT_TOOBIG &&
David S. Millerec18d9a2012-07-12 00:25:15 -0700434 type != NDISC_REDIRECT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 return;
436
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000437 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
438 esph->spi, IPPROTO_ESP, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 if (!x)
440 return;
David S. Millerec18d9a2012-07-12 00:25:15 -0700441
442 if (type == NDISC_REDIRECT)
Duan Jiongb55b76b2013-09-04 19:44:21 +0800443 ip6_redirect(skb, net, skb->dev->ifindex, 0);
David S. Millerec18d9a2012-07-12 00:25:15 -0700444 else
445 ip6_update_pmtu(skb, net, info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 xfrm_state_put(x);
447}
448
449static void esp6_destroy(struct xfrm_state *x)
450{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200451 struct crypto_aead *aead = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
Mathias Krause1c5ad132013-10-18 12:09:05 +0200453 if (!aead)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 return;
455
Mathias Krause1c5ad132013-10-18 12:09:05 +0200456 crypto_free_aead(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457}
458
Herbert Xu1a6509d2008-01-28 19:37:29 -0800459static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800461 struct crypto_aead *aead;
462 int err;
463
464 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
465 err = PTR_ERR(aead);
466 if (IS_ERR(aead))
467 goto error;
468
Mathias Krause1c5ad132013-10-18 12:09:05 +0200469 x->data = aead;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800470
471 err = crypto_aead_setkey(aead, x->aead->alg_key,
472 (x->aead->alg_key_len + 7) / 8);
473 if (err)
474 goto error;
475
476 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
477 if (err)
478 goto error;
479
480error:
481 return err;
482}
483
484static int esp_init_authenc(struct xfrm_state *x)
485{
Herbert Xu38320c72008-01-28 19:35:05 -0800486 struct crypto_aead *aead;
487 struct crypto_authenc_key_param *param;
488 struct rtattr *rta;
489 char *key;
490 char *p;
491 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800492 unsigned int keylen;
493 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
Herbert Xu1a6509d2008-01-28 19:37:29 -0800495 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 if (x->ealg == NULL)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800497 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
Herbert Xu1a6509d2008-01-28 19:37:29 -0800499 err = -ENAMETOOLONG;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000500
501 if ((x->props.flags & XFRM_STATE_ESN)) {
502 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
503 "authencesn(%s,%s)",
504 x->aalg ? x->aalg->alg_name : "digest_null",
505 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
506 goto error;
507 } else {
508 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
509 "authenc(%s,%s)",
510 x->aalg ? x->aalg->alg_name : "digest_null",
511 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
512 goto error;
513 }
Herbert Xu38320c72008-01-28 19:35:05 -0800514
515 aead = crypto_alloc_aead(authenc_name, 0, 0);
516 err = PTR_ERR(aead);
517 if (IS_ERR(aead))
518 goto error;
519
Mathias Krause1c5ad132013-10-18 12:09:05 +0200520 x->data = aead;
Herbert Xu38320c72008-01-28 19:35:05 -0800521
522 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
523 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
524 err = -ENOMEM;
525 key = kmalloc(keylen, GFP_KERNEL);
526 if (!key)
527 goto error;
528
529 p = key;
530 rta = (void *)p;
531 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
532 rta->rta_len = RTA_LENGTH(sizeof(*param));
533 param = RTA_DATA(rta);
534 p += RTA_SPACE(sizeof(*param));
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 if (x->aalg) {
537 struct xfrm_algo_desc *aalg_desc;
538
Herbert Xu38320c72008-01-28 19:35:05 -0800539 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
540 p += (x->aalg->alg_key_len + 7) / 8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900541
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
543 BUG_ON(!aalg_desc);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900544
Herbert Xu38320c72008-01-28 19:35:05 -0800545 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800547 crypto_aead_authsize(aead)) {
Herbert Xu07d4ee52006-08-20 14:24:50 +1000548 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
549 x->aalg->alg_name,
Herbert Xu38320c72008-01-28 19:35:05 -0800550 crypto_aead_authsize(aead),
Herbert Xu07d4ee52006-08-20 14:24:50 +1000551 aalg_desc->uinfo.auth.icv_fullbits/8);
Herbert Xu38320c72008-01-28 19:35:05 -0800552 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900554
Herbert Xu38320c72008-01-28 19:35:05 -0800555 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000556 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800557 if (err)
558 goto free_key;
559 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900560
Herbert Xu38320c72008-01-28 19:35:05 -0800561 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
562 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
563
564 err = crypto_aead_setkey(aead, key, keylen);
565
566free_key:
567 kfree(key);
568
Herbert Xu1a6509d2008-01-28 19:37:29 -0800569error:
570 return err;
571}
572
573static int esp6_init_state(struct xfrm_state *x)
574{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800575 struct crypto_aead *aead;
576 u32 align;
577 int err;
578
579 if (x->encap)
580 return -EINVAL;
581
Mathias Krause1c5ad132013-10-18 12:09:05 +0200582 x->data = NULL;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800583
584 if (x->aead)
585 err = esp_init_aead(x);
586 else
587 err = esp_init_authenc(x);
588
Herbert Xu38320c72008-01-28 19:35:05 -0800589 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800591
Mathias Krause1c5ad132013-10-18 12:09:05 +0200592 aead = x->data;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800593
Herbert Xu38320c72008-01-28 19:35:05 -0800594 x->props.header_len = sizeof(struct ip_esp_hdr) +
595 crypto_aead_ivsize(aead);
Herbert Xuca681452007-10-17 21:35:15 -0700596 switch (x->props.mode) {
597 case XFRM_MODE_BEET:
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700598 if (x->sel.family != AF_INET6)
599 x->props.header_len += IPV4_BEET_PHMAXLEN +
600 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
601 break;
Herbert Xuca681452007-10-17 21:35:15 -0700602 case XFRM_MODE_TRANSPORT:
603 break;
604 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700606 break;
Herbert Xuca681452007-10-17 21:35:15 -0700607 default:
608 goto error;
609 }
Herbert Xu38320c72008-01-28 19:35:05 -0800610
611 align = ALIGN(crypto_aead_blocksize(aead), 4);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200612 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613
614error:
Herbert Xu38320c72008-01-28 19:35:05 -0800615 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616}
617
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800618static const struct xfrm_type esp6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619{
620 .description = "ESP6",
621 .owner = THIS_MODULE,
622 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700623 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 .init_state = esp6_init_state,
625 .destructor = esp6_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700626 .get_mtu = esp6_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 .input = esp6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700628 .output = esp6_output,
629 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630};
631
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000632static const struct inet6_protocol esp6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 .handler = xfrm6_rcv,
634 .err_handler = esp6_err,
635 .flags = INET6_PROTO_NOPOLICY,
636};
637
638static int __init esp6_init(void)
639{
640 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000641 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 return -EAGAIN;
643 }
644 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000645 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 xfrm_unregister_type(&esp6_type, AF_INET6);
647 return -EAGAIN;
648 }
649
650 return 0;
651}
652
653static void __exit esp6_fini(void)
654{
655 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000656 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000658 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
661module_init(esp6_init);
662module_exit(esp6_fini);
663
664MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700665MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);