blob: d3618a78fcac4b1f6e606a904196de79235833b1 [file] [log] [blame]
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;
Arnaldo Carvalho de Meloea2ae172007-04-25 17:55:53 -0700167 struct esp_data *esp = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168
Herbert Xu7b277b12007-10-10 15:44:06 -0700169 /* skb is pure payload to encrypt */
Herbert Xu38320c72008-01-28 19:35:05 -0800170 aead = esp->aead;
171 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Martin Willi040253c2010-12-08 04:37:51 +0000173 tfclen = 0;
174 if (x->tfcpad) {
175 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
176 u32 padto;
177
178 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
179 if (skb->len < padto)
180 tfclen = padto - skb->len;
181 }
Herbert Xu38320c72008-01-28 19:35:05 -0800182 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willi040253c2010-12-08 04:37:51 +0000183 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Herbert Xu38320c72008-01-28 19:35:05 -0800184 if (esp->padlen)
185 clen = ALIGN(clen, esp->padlen);
Martin Willi040253c2010-12-08 04:37:51 +0000186 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800187
Martin Willi040253c2010-12-08 04:37:51 +0000188 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
189 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800191 nfrags = err;
192
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000193 assoclen = sizeof(*esph);
194 sglists = 1;
195 seqhilen = 0;
196
197 if (x->props.flags & XFRM_STATE_ESN) {
198 sglists += 2;
199 seqhilen += sizeof(__be32);
200 assoclen += seqhilen;
201 }
202
203 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Julia Lawall48f125c2012-08-29 06:49:12 +0000204 if (!tmp) {
205 err = -ENOMEM;
Herbert Xu38320c72008-01-28 19:35:05 -0800206 goto error;
Julia Lawall48f125c2012-08-29 06:49:12 +0000207 }
Herbert Xu38320c72008-01-28 19:35:05 -0800208
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000209 seqhi = esp_tmp_seqhi(tmp);
210 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800211 req = esp_tmp_givreq(aead, iv);
212 asg = esp_givreq_sg(aead, req);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000213 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700216 tail = skb_tail_pointer(trailer);
Martin Willi040253c2010-12-08 04:37:51 +0000217 if (tfclen) {
218 memset(tail, 0, tfclen);
219 tail += tfclen;
220 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 do {
222 int i;
Martin Willi040253c2010-12-08 04:37:51 +0000223 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700224 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 } while (0);
Martin Willi040253c2010-12-08 04:37:51 +0000226 tail[plen - 2] = plen - 2;
227 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800228 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Herbert Xu7b277b12007-10-10 15:44:06 -0700230 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700231 esph = ip_esp_hdr(skb);
Herbert Xu007f0212007-10-09 13:25:59 -0700232 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
234 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000235 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236
Herbert Xu38320c72008-01-28 19:35:05 -0800237 sg_init_table(sg, nfrags);
238 skb_to_sgvec(skb, sg,
239 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
240 clen + alen);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000241
242 if ((x->props.flags & XFRM_STATE_ESN)) {
243 sg_init_table(asg, 3);
244 sg_set_buf(asg, &esph->spi, sizeof(__be32));
245 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
246 sg_set_buf(asg + 1, seqhi, seqhilen);
247 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
248 } else
249 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xub7c65382007-10-09 13:33:35 -0700250
Herbert Xu38320c72008-01-28 19:35:05 -0800251 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
252 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000253 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800254 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000255 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Herbert Xu38320c72008-01-28 19:35:05 -0800257 ESP_SKB_CB(skb)->tmp = tmp;
258 err = crypto_aead_givencrypt(req);
259 if (err == -EINPROGRESS)
260 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261
Herbert Xu38320c72008-01-28 19:35:05 -0800262 if (err == -EBUSY)
263 err = NET_XMIT_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
Herbert Xu38320c72008-01-28 19:35:05 -0800265 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267error:
268 return err;
269}
270
Herbert Xu38320c72008-01-28 19:35:05 -0800271static int esp_input_done2(struct sk_buff *skb, int err)
272{
273 struct xfrm_state *x = xfrm_input_state(skb);
274 struct esp_data *esp = x->data;
275 struct crypto_aead *aead = esp->aead;
276 int alen = crypto_aead_authsize(aead);
277 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
278 int elen = skb->len - hlen;
279 int hdr_len = skb_network_header_len(skb);
280 int padlen;
281 u8 nexthdr[2];
282
283 kfree(ESP_SKB_CB(skb)->tmp);
284
285 if (unlikely(err))
286 goto out;
287
288 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
289 BUG();
290
291 err = -EINVAL;
292 padlen = nexthdr[0];
293 if (padlen + 2 + alen >= elen) {
294 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
295 "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
296 goto out;
297 }
298
299 /* ... check padding bits here. Silly. :-) */
300
301 pskb_trim(skb, skb->len - alen - padlen - 2);
302 __skb_pull(skb, hlen);
Li RongQinga9403f82013-01-08 15:41:12 +0800303 if (x->props.mode == XFRM_MODE_TUNNEL)
304 skb_reset_transport_header(skb);
305 else
306 skb_set_transport_header(skb, -hdr_len);
Herbert Xu38320c72008-01-28 19:35:05 -0800307
308 err = nexthdr[1];
309
310 /* RFC4303: Drop dummy packets without any error */
311 if (err == IPPROTO_NONE)
312 err = -EINVAL;
313
314out:
315 return err;
316}
317
318static void esp_input_done(struct crypto_async_request *base, int err)
319{
320 struct sk_buff *skb = base->data;
321
322 xfrm_input_resume(skb, esp_input_done2(skb, err));
323}
324
Herbert Xue6956332006-04-01 00:52:46 -0800325static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326{
Herbert Xu87bdc482007-10-10 15:45:25 -0700327 struct ip_esp_hdr *esph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800329 struct crypto_aead *aead = esp->aead;
330 struct aead_request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800332 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000334 int assoclen;
335 int sglists;
336 int seqhilen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 int ret = 0;
Herbert Xu38320c72008-01-28 19:35:05 -0800338 void *tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000339 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800340 u8 *iv;
341 struct scatterlist *sg;
342 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
Thomas Graf920fc942008-03-27 16:08:03 -0700344 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
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
Herbert Xu38320c72008-01-28 19:35:05 -0800349 if (elen <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700351 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 }
353
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
355 ret = -EINVAL;
356 goto out;
357 }
358
Herbert Xu38320c72008-01-28 19:35:05 -0800359 ret = -ENOMEM;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000360
361 assoclen = sizeof(*esph);
362 sglists = 1;
363 seqhilen = 0;
364
365 if (x->props.flags & XFRM_STATE_ESN) {
366 sglists += 2;
367 seqhilen += sizeof(__be32);
368 assoclen += seqhilen;
369 }
370
371 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800372 if (!tmp)
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800373 goto out;
374
Herbert Xu38320c72008-01-28 19:35:05 -0800375 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000376 seqhi = esp_tmp_seqhi(tmp);
377 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800378 req = esp_tmp_req(aead, iv);
379 asg = esp_req_sg(aead, req);
Steffen Klassertc0a56e62011-04-25 19:40:23 +0000380 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
Herbert Xu38320c72008-01-28 19:35:05 -0800382 skb->ip_summed = CHECKSUM_NONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Herbert Xu38320c72008-01-28 19:35:05 -0800384 esph = (struct ip_esp_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385
Herbert Xu38320c72008-01-28 19:35:05 -0800386 /* Get ivec. This can be wrong, check against another impls. */
387 iv = esph->enc_data;
Thomas Graf95a02cf2007-12-10 16:53:29 -0800388
Herbert Xu38320c72008-01-28 19:35:05 -0800389 sg_init_table(sg, nfrags);
390 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000391
392 if ((x->props.flags & XFRM_STATE_ESN)) {
393 sg_init_table(asg, 3);
394 sg_set_buf(asg, &esph->spi, sizeof(__be32));
395 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
396 sg_set_buf(asg + 1, seqhi, seqhilen);
397 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
398 } else
399 sg_init_one(asg, esph, sizeof(*esph));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
Herbert Xu38320c72008-01-28 19:35:05 -0800401 aead_request_set_callback(req, 0, esp_input_done, skb);
402 aead_request_set_crypt(req, sg, sg, elen, iv);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000403 aead_request_set_assoc(req, asg, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800404
405 ret = crypto_aead_decrypt(req);
406 if (ret == -EINPROGRESS)
407 goto out;
408
409 ret = esp_input_done2(skb, ret);
410
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 return ret;
413}
414
Patrick McHardyc5c25232007-04-09 11:47:18 -0700415static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416{
417 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800418 u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
419 u32 align = max_t(u32, blksize, esp->padlen);
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000420 unsigned int net_adj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000422 if (x->props.mode != XFRM_MODE_TUNNEL)
423 net_adj = sizeof(struct ipv6hdr);
424 else
425 net_adj = 0;
Patrick McHardyc5c25232007-04-09 11:47:18 -0700426
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000427 return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
Daniel Borkmann79218952013-08-05 12:49:35 +0200428 net_adj) & ~(align - 1)) + net_adj - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429}
430
431static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
Brian Haleyd5fdd6b2009-06-23 04:31:07 -0700432 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800434 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000435 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
Herbert Xu87bdc482007-10-10 15:45:25 -0700436 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 struct xfrm_state *x;
438
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900439 if (type != ICMPV6_DEST_UNREACH &&
David S. Millerec18d9a2012-07-12 00:25:15 -0700440 type != ICMPV6_PKT_TOOBIG &&
441 type != NDISC_REDIRECT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 return;
443
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000444 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
445 esph->spi, IPPROTO_ESP, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 if (!x)
447 return;
David S. Millerec18d9a2012-07-12 00:25:15 -0700448
449 if (type == NDISC_REDIRECT)
Duan Jiongb55b76b2013-09-04 19:44:21 +0800450 ip6_redirect(skb, net, skb->dev->ifindex, 0);
David S. Millerec18d9a2012-07-12 00:25:15 -0700451 else
452 ip6_update_pmtu(skb, net, info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 xfrm_state_put(x);
454}
455
456static void esp6_destroy(struct xfrm_state *x)
457{
458 struct esp_data *esp = x->data;
459
460 if (!esp)
461 return;
462
Herbert Xu38320c72008-01-28 19:35:05 -0800463 crypto_free_aead(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 kfree(esp);
465}
466
Herbert Xu1a6509d2008-01-28 19:37:29 -0800467static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800469 struct esp_data *esp = x->data;
470 struct crypto_aead *aead;
471 int err;
472
473 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
474 err = PTR_ERR(aead);
475 if (IS_ERR(aead))
476 goto error;
477
478 esp->aead = aead;
479
480 err = crypto_aead_setkey(aead, x->aead->alg_key,
481 (x->aead->alg_key_len + 7) / 8);
482 if (err)
483 goto error;
484
485 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
486 if (err)
487 goto error;
488
489error:
490 return err;
491}
492
493static int esp_init_authenc(struct xfrm_state *x)
494{
495 struct esp_data *esp = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800496 struct crypto_aead *aead;
497 struct crypto_authenc_key_param *param;
498 struct rtattr *rta;
499 char *key;
500 char *p;
501 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800502 unsigned int keylen;
503 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
Herbert Xu1a6509d2008-01-28 19:37:29 -0800505 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 if (x->ealg == NULL)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800507 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508
Herbert Xu1a6509d2008-01-28 19:37:29 -0800509 err = -ENAMETOOLONG;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000510
511 if ((x->props.flags & XFRM_STATE_ESN)) {
512 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
513 "authencesn(%s,%s)",
514 x->aalg ? x->aalg->alg_name : "digest_null",
515 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
516 goto error;
517 } else {
518 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
519 "authenc(%s,%s)",
520 x->aalg ? x->aalg->alg_name : "digest_null",
521 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
522 goto error;
523 }
Herbert Xu38320c72008-01-28 19:35:05 -0800524
525 aead = crypto_alloc_aead(authenc_name, 0, 0);
526 err = PTR_ERR(aead);
527 if (IS_ERR(aead))
528 goto error;
529
530 esp->aead = aead;
531
532 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
533 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
534 err = -ENOMEM;
535 key = kmalloc(keylen, GFP_KERNEL);
536 if (!key)
537 goto error;
538
539 p = key;
540 rta = (void *)p;
541 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
542 rta->rta_len = RTA_LENGTH(sizeof(*param));
543 param = RTA_DATA(rta);
544 p += RTA_SPACE(sizeof(*param));
545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 if (x->aalg) {
547 struct xfrm_algo_desc *aalg_desc;
548
Herbert Xu38320c72008-01-28 19:35:05 -0800549 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
550 p += (x->aalg->alg_key_len + 7) / 8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900551
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
553 BUG_ON(!aalg_desc);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900554
Herbert Xu38320c72008-01-28 19:35:05 -0800555 err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800557 crypto_aead_authsize(aead)) {
Herbert Xu07d4ee52006-08-20 14:24:50 +1000558 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
559 x->aalg->alg_name,
Herbert Xu38320c72008-01-28 19:35:05 -0800560 crypto_aead_authsize(aead),
Herbert Xu07d4ee52006-08-20 14:24:50 +1000561 aalg_desc->uinfo.auth.icv_fullbits/8);
Herbert Xu38320c72008-01-28 19:35:05 -0800562 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900564
Herbert Xu38320c72008-01-28 19:35:05 -0800565 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000566 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800567 if (err)
568 goto free_key;
569 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900570
Herbert Xu38320c72008-01-28 19:35:05 -0800571 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
572 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
573
574 err = crypto_aead_setkey(aead, key, keylen);
575
576free_key:
577 kfree(key);
578
Herbert Xu1a6509d2008-01-28 19:37:29 -0800579error:
580 return err;
581}
582
583static int esp6_init_state(struct xfrm_state *x)
584{
585 struct esp_data *esp;
586 struct crypto_aead *aead;
587 u32 align;
588 int err;
589
590 if (x->encap)
591 return -EINVAL;
592
593 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
594 if (esp == NULL)
595 return -ENOMEM;
596
597 x->data = esp;
598
599 if (x->aead)
600 err = esp_init_aead(x);
601 else
602 err = esp_init_authenc(x);
603
Herbert Xu38320c72008-01-28 19:35:05 -0800604 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800606
Herbert Xu1a6509d2008-01-28 19:37:29 -0800607 aead = esp->aead;
608
609 esp->padlen = 0;
610
Herbert Xu38320c72008-01-28 19:35:05 -0800611 x->props.header_len = sizeof(struct ip_esp_hdr) +
612 crypto_aead_ivsize(aead);
Herbert Xuca681452007-10-17 21:35:15 -0700613 switch (x->props.mode) {
614 case XFRM_MODE_BEET:
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700615 if (x->sel.family != AF_INET6)
616 x->props.header_len += IPV4_BEET_PHMAXLEN +
617 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
618 break;
Herbert Xuca681452007-10-17 21:35:15 -0700619 case XFRM_MODE_TRANSPORT:
620 break;
621 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700623 break;
Herbert Xuca681452007-10-17 21:35:15 -0700624 default:
625 goto error;
626 }
Herbert Xu38320c72008-01-28 19:35:05 -0800627
628 align = ALIGN(crypto_aead_blocksize(aead), 4);
629 if (esp->padlen)
630 align = max_t(u32, align, esp->padlen);
631 x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633error:
Herbert Xu38320c72008-01-28 19:35:05 -0800634 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635}
636
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800637static const struct xfrm_type esp6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638{
639 .description = "ESP6",
640 .owner = THIS_MODULE,
641 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700642 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 .init_state = esp6_init_state,
644 .destructor = esp6_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700645 .get_mtu = esp6_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 .input = esp6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700647 .output = esp6_output,
648 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649};
650
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000651static const struct inet6_protocol esp6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 .handler = xfrm6_rcv,
653 .err_handler = esp6_err,
654 .flags = INET6_PROTO_NOPOLICY,
655};
656
657static int __init esp6_init(void)
658{
659 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000660 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 return -EAGAIN;
662 }
663 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000664 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 xfrm_unregister_type(&esp6_type, AF_INET6);
666 return -EAGAIN;
667 }
668
669 return 0;
670}
671
672static void __exit esp6_fini(void)
673{
674 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000675 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000677 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678}
679
680module_init(esp6_init);
681module_exit(esp6_fini);
682
683MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700684MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);