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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
Jeff Kirshera99421d2013-12-06 09:13:39 -080015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 *
17 * Authors
18 *
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090019 * Mitsuru KANDA @USAGI : IPv6 Support
Ian Morris67ba4152014-08-24 21:53:10 +010020 * Kazunori MIYAZAWA @USAGI :
21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090022 *
Ian Morris67ba4152014-08-24 21:53:10 +010023 * This file is derived from net/ipv4/esp.c
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 */
25
Joe Perchesf3213832012-05-15 14:11:53 +000026#define pr_fmt(fmt) "IPv6: " fmt
27
Herbert Xu38320c72008-01-28 19:35:05 -080028#include <crypto/aead.h>
29#include <crypto/authenc.h>
Herbert Xu6b7326c2006-07-30 15:41:01 +100030#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/module.h>
32#include <net/ip.h>
33#include <net/xfrm.h>
34#include <net/esp.h>
Adrian Bunk72998d82007-10-26 22:53:58 -070035#include <linux/scatterlist.h>
Herbert Xua02a6422005-10-10 21:11:08 -070036#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/pfkeyv2.h>
38#include <linux/random.h>
Herbert Xu38320c72008-01-28 19:35:05 -080039#include <linux/slab.h>
Herbert Xub7c65382007-10-09 13:33:35 -070040#include <linux/spinlock.h>
David S. Miller81aded22012-06-15 14:54:11 -070041#include <net/ip6_route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#include <net/icmp.h>
43#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020044#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#include <linux/icmpv6.h>
46
Herbert Xu38320c72008-01-28 19:35:05 -080047struct esp_skb_cb {
48 struct xfrm_skb_cb xfrm;
49 void *tmp;
50};
51
52#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
53
Martin Willi040253c2010-12-08 04:37:51 +000054static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
55
Herbert Xu38320c72008-01-28 19:35:05 -080056/*
57 * Allocate an AEAD request structure with extra space for SG and IV.
58 *
Steffen Klassertd212a4c2011-03-08 00:07:51 +000059 * For alignment considerations the upper 32 bits of the sequence number are
60 * placed at the front, if present. Followed by the IV, the request and finally
61 * the SG list.
Herbert Xu38320c72008-01-28 19:35:05 -080062 *
63 * TODO: Use spare space in skb for this where possible.
64 */
Steffen Klassertd212a4c2011-03-08 00:07:51 +000065static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
Herbert Xu38320c72008-01-28 19:35:05 -080066{
67 unsigned int len;
68
Steffen Klassertd212a4c2011-03-08 00:07:51 +000069 len = seqihlen;
70
71 len += crypto_aead_ivsize(aead);
72
Herbert Xu38320c72008-01-28 19:35:05 -080073 if (len) {
74 len += crypto_aead_alignmask(aead) &
75 ~(crypto_tfm_ctx_alignment() - 1);
76 len = ALIGN(len, crypto_tfm_ctx_alignment());
77 }
78
79 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
80 len = ALIGN(len, __alignof__(struct scatterlist));
81
82 len += sizeof(struct scatterlist) * nfrags;
83
84 return kmalloc(len, GFP_ATOMIC);
85}
86
Steffen Klassertd212a4c2011-03-08 00:07:51 +000087static inline __be32 *esp_tmp_seqhi(void *tmp)
88{
89 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
90}
91
92static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
Herbert Xu38320c72008-01-28 19:35:05 -080093{
94 return crypto_aead_ivsize(aead) ?
Steffen Klassertd212a4c2011-03-08 00:07:51 +000095 PTR_ALIGN((u8 *)tmp + seqhilen,
96 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -080097}
98
99static inline struct aead_givcrypt_request *esp_tmp_givreq(
100 struct crypto_aead *aead, u8 *iv)
101{
102 struct aead_givcrypt_request *req;
103
104 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
105 crypto_tfm_ctx_alignment());
106 aead_givcrypt_set_tfm(req, aead);
107 return req;
108}
109
110static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
111{
112 struct aead_request *req;
113
114 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
115 crypto_tfm_ctx_alignment());
116 aead_request_set_tfm(req, aead);
117 return req;
118}
119
120static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
121 struct aead_request *req)
122{
123 return (void *)ALIGN((unsigned long)(req + 1) +
124 crypto_aead_reqsize(aead),
125 __alignof__(struct scatterlist));
126}
127
128static inline struct scatterlist *esp_givreq_sg(
129 struct crypto_aead *aead, struct aead_givcrypt_request *req)
130{
131 return (void *)ALIGN((unsigned long)(req + 1) +
132 crypto_aead_reqsize(aead),
133 __alignof__(struct scatterlist));
134}
135
136static void esp_output_done(struct crypto_async_request *base, int err)
137{
138 struct sk_buff *skb = base->data;
139
140 kfree(ESP_SKB_CB(skb)->tmp);
141 xfrm_output_resume(skb, err);
142}
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
145{
146 int err;
Herbert Xu87bdc482007-10-10 15:45:25 -0700147 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800148 struct crypto_aead *aead;
149 struct aead_givcrypt_request *req;
150 struct scatterlist *sg;
151 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800153 void *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 int blksize;
155 int clen;
156 int alen;
Martin Willi040253c2010-12-08 04:37:51 +0000157 int plen;
158 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000160 int assoclen;
161 int sglists;
162 int seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -0800163 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700164 u8 *tail;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000165 __be32 *seqhi;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166
Herbert Xu7b277b12007-10-10 15:44:06 -0700167 /* skb is pure payload to encrypt */
Mathias Krause1c5ad132013-10-18 12:09:05 +0200168 aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800169 alen = crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Martin Willi040253c2010-12-08 04:37:51 +0000171 tfclen = 0;
172 if (x->tfcpad) {
173 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
174 u32 padto;
175
176 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
177 if (skb->len < padto)
178 tfclen = padto - skb->len;
179 }
Herbert Xu38320c72008-01-28 19:35:05 -0800180 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willi040253c2010-12-08 04:37:51 +0000181 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Martin Willi040253c2010-12-08 04:37:51 +0000182 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800183
Martin Willi040253c2010-12-08 04:37:51 +0000184 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
185 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800187 nfrags = err;
188
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000189 assoclen = sizeof(*esph);
190 sglists = 1;
191 seqhilen = 0;
192
193 if (x->props.flags & XFRM_STATE_ESN) {
194 sglists += 2;
195 seqhilen += sizeof(__be32);
196 assoclen += seqhilen;
197 }
198
199 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
Julia Lawall48f125c2012-08-29 06:49:12 +0000200 if (!tmp) {
201 err = -ENOMEM;
Herbert Xu38320c72008-01-28 19:35:05 -0800202 goto error;
Julia Lawall48f125c2012-08-29 06:49:12 +0000203 }
Herbert Xu38320c72008-01-28 19:35:05 -0800204
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000205 seqhi = esp_tmp_seqhi(tmp);
206 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800207 req = esp_tmp_givreq(aead, iv);
208 asg = esp_givreq_sg(aead, req);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000209 sg = asg + sglists;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700212 tail = skb_tail_pointer(trailer);
Martin Willi040253c2010-12-08 04:37:51 +0000213 if (tfclen) {
214 memset(tail, 0, tfclen);
215 tail += tfclen;
216 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 do {
218 int i;
Martin Willi040253c2010-12-08 04:37:51 +0000219 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700220 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 } while (0);
Martin Willi040253c2010-12-08 04:37:51 +0000222 tail[plen - 2] = plen - 2;
223 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800224 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Herbert Xu7b277b12007-10-10 15:44:06 -0700226 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700227 esph = ip_esp_hdr(skb);
Herbert Xu007f0212007-10-09 13:25:59 -0700228 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 esph->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000231 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
Herbert Xu38320c72008-01-28 19:35:05 -0800233 sg_init_table(sg, nfrags);
234 skb_to_sgvec(skb, sg,
235 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
236 clen + alen);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000237
238 if ((x->props.flags & XFRM_STATE_ESN)) {
239 sg_init_table(asg, 3);
240 sg_set_buf(asg, &esph->spi, sizeof(__be32));
241 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
242 sg_set_buf(asg + 1, seqhi, seqhilen);
243 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
244 } else
245 sg_init_one(asg, esph, sizeof(*esph));
Herbert Xub7c65382007-10-09 13:33:35 -0700246
Herbert Xu38320c72008-01-28 19:35:05 -0800247 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
248 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000249 aead_givcrypt_set_assoc(req, asg, assoclen);
Herbert Xub318e0e2008-02-12 22:50:35 -0800250 aead_givcrypt_set_giv(req, esph->enc_data,
Steffen Klassert1ce36442011-03-08 00:06:31 +0000251 XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
Herbert Xu38320c72008-01-28 19:35:05 -0800253 ESP_SKB_CB(skb)->tmp = tmp;
254 err = crypto_aead_givencrypt(req);
255 if (err == -EINPROGRESS)
256 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
Herbert Xu38320c72008-01-28 19:35:05 -0800258 if (err == -EBUSY)
259 err = NET_XMIT_DROP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Herbert Xu38320c72008-01-28 19:35:05 -0800261 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263error:
264 return err;
265}
266
Herbert Xu38320c72008-01-28 19:35:05 -0800267static int esp_input_done2(struct sk_buff *skb, int err)
268{
269 struct xfrm_state *x = xfrm_input_state(skb);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200270 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800271 int alen = crypto_aead_authsize(aead);
272 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
273 int elen = skb->len - hlen;
274 int hdr_len = skb_network_header_len(skb);
275 int padlen;
276 u8 nexthdr[2];
277
278 kfree(ESP_SKB_CB(skb)->tmp);
279
280 if (unlikely(err))
281 goto out;
282
283 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
284 BUG();
285
286 err = -EINVAL;
287 padlen = nexthdr[0];
288 if (padlen + 2 + alen >= elen) {
Joe Perchesba7a46f2014-11-11 10:59:17 -0800289 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
290 padlen + 2, elen - alen);
Herbert Xu38320c72008-01-28 19:35:05 -0800291 goto out;
292 }
293
294 /* ... check padding bits here. Silly. :-) */
295
296 pskb_trim(skb, skb->len - alen - padlen - 2);
297 __skb_pull(skb, hlen);
Li RongQinga9403f82013-01-08 15:41:12 +0800298 if (x->props.mode == XFRM_MODE_TUNNEL)
299 skb_reset_transport_header(skb);
300 else
301 skb_set_transport_header(skb, -hdr_len);
Herbert Xu38320c72008-01-28 19:35:05 -0800302
303 err = nexthdr[1];
304
305 /* RFC4303: Drop dummy packets without any error */
306 if (err == IPPROTO_NONE)
307 err = -EINVAL;
308
309out:
310 return err;
311}
312
313static void esp_input_done(struct crypto_async_request *base, int err)
314{
315 struct sk_buff *skb = base->data;
316
317 xfrm_input_resume(skb, esp_input_done2(skb, err));
318}
319
Herbert Xue6956332006-04-01 00:52:46 -0800320static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321{
Herbert Xu87bdc482007-10-10 15:45:25 -0700322 struct ip_esp_hdr *esph;
Mathias Krause1c5ad132013-10-18 12:09:05 +0200323 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800324 struct aead_request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800326 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000328 int assoclen;
329 int sglists;
330 int seqhilen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 int ret = 0;
Herbert Xu38320c72008-01-28 19:35:05 -0800332 void *tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000333 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800334 u8 *iv;
335 struct scatterlist *sg;
336 struct scatterlist *asg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337
Thomas Graf920fc942008-03-27 16:08:03 -0700338 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700340 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 }
342
Herbert Xu38320c72008-01-28 19:35:05 -0800343 if (elen <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700345 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 }
347
Ian Morrise5d08d72014-11-23 21:28:43 +0000348 nfrags = skb_cow_data(skb, 0, &trailer);
349 if (nfrags < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 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
Steffen Klassertd5860c52014-03-14 07:28:07 +0100425static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
426 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)
Steffen Klassertd5860c52014-03-14 07:28:07 +0100435 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
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)
Steffen Klassertd5860c52014-03-14 07:28:07 +0100440 return 0;
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);
Steffen Klassertd5860c52014-03-14 07:28:07 +0100447
448 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449}
450
451static void esp6_destroy(struct xfrm_state *x)
452{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200453 struct crypto_aead *aead = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
Mathias Krause1c5ad132013-10-18 12:09:05 +0200455 if (!aead)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 return;
457
Mathias Krause1c5ad132013-10-18 12:09:05 +0200458 crypto_free_aead(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459}
460
Herbert Xu1a6509d2008-01-28 19:37:29 -0800461static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800463 struct crypto_aead *aead;
464 int err;
465
466 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
467 err = PTR_ERR(aead);
468 if (IS_ERR(aead))
469 goto error;
470
Mathias Krause1c5ad132013-10-18 12:09:05 +0200471 x->data = aead;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800472
473 err = crypto_aead_setkey(aead, x->aead->alg_key,
474 (x->aead->alg_key_len + 7) / 8);
475 if (err)
476 goto error;
477
478 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
479 if (err)
480 goto error;
481
482error:
483 return err;
484}
485
486static int esp_init_authenc(struct xfrm_state *x)
487{
Herbert Xu38320c72008-01-28 19:35:05 -0800488 struct crypto_aead *aead;
489 struct crypto_authenc_key_param *param;
490 struct rtattr *rta;
491 char *key;
492 char *p;
493 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800494 unsigned int keylen;
495 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
Herbert Xu1a6509d2008-01-28 19:37:29 -0800497 err = -EINVAL;
Ian Morris63159f22015-03-29 14:00:04 +0100498 if (!x->ealg)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800499 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500
Herbert Xu1a6509d2008-01-28 19:37:29 -0800501 err = -ENAMETOOLONG;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000502
503 if ((x->props.flags & XFRM_STATE_ESN)) {
504 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
505 "authencesn(%s,%s)",
506 x->aalg ? x->aalg->alg_name : "digest_null",
507 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
508 goto error;
509 } else {
510 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
511 "authenc(%s,%s)",
512 x->aalg ? x->aalg->alg_name : "digest_null",
513 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
514 goto error;
515 }
Herbert Xu38320c72008-01-28 19:35:05 -0800516
517 aead = crypto_alloc_aead(authenc_name, 0, 0);
518 err = PTR_ERR(aead);
519 if (IS_ERR(aead))
520 goto error;
521
Mathias Krause1c5ad132013-10-18 12:09:05 +0200522 x->data = aead;
Herbert Xu38320c72008-01-28 19:35:05 -0800523
524 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
525 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
526 err = -ENOMEM;
527 key = kmalloc(keylen, GFP_KERNEL);
528 if (!key)
529 goto error;
530
531 p = key;
532 rta = (void *)p;
533 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
534 rta->rta_len = RTA_LENGTH(sizeof(*param));
535 param = RTA_DATA(rta);
536 p += RTA_SPACE(sizeof(*param));
537
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 if (x->aalg) {
539 struct xfrm_algo_desc *aalg_desc;
540
Herbert Xu38320c72008-01-28 19:35:05 -0800541 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
542 p += (x->aalg->alg_key_len + 7) / 8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
545 BUG_ON(!aalg_desc);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900546
Herbert Xu38320c72008-01-28 19:35:05 -0800547 err = -EINVAL;
Joe Perches45083492014-11-05 15:36:08 -0800548 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800549 crypto_aead_authsize(aead)) {
Joe Perches45083492014-11-05 15:36:08 -0800550 pr_info("ESP: %s digestsize %u != %hu\n",
551 x->aalg->alg_name,
552 crypto_aead_authsize(aead),
553 aalg_desc->uinfo.auth.icv_fullbits / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800554 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900556
Herbert Xu38320c72008-01-28 19:35:05 -0800557 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000558 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800559 if (err)
560 goto free_key;
561 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900562
Herbert Xu38320c72008-01-28 19:35:05 -0800563 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
564 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
565
566 err = crypto_aead_setkey(aead, key, keylen);
567
568free_key:
569 kfree(key);
570
Herbert Xu1a6509d2008-01-28 19:37:29 -0800571error:
572 return err;
573}
574
575static int esp6_init_state(struct xfrm_state *x)
576{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800577 struct crypto_aead *aead;
578 u32 align;
579 int err;
580
581 if (x->encap)
582 return -EINVAL;
583
Mathias Krause1c5ad132013-10-18 12:09:05 +0200584 x->data = NULL;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800585
586 if (x->aead)
587 err = esp_init_aead(x);
588 else
589 err = esp_init_authenc(x);
590
Herbert Xu38320c72008-01-28 19:35:05 -0800591 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800593
Mathias Krause1c5ad132013-10-18 12:09:05 +0200594 aead = x->data;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800595
Herbert Xu38320c72008-01-28 19:35:05 -0800596 x->props.header_len = sizeof(struct ip_esp_hdr) +
597 crypto_aead_ivsize(aead);
Herbert Xuca681452007-10-17 21:35:15 -0700598 switch (x->props.mode) {
599 case XFRM_MODE_BEET:
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700600 if (x->sel.family != AF_INET6)
601 x->props.header_len += IPV4_BEET_PHMAXLEN +
Ian Morris67ba4152014-08-24 21:53:10 +0100602 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700603 break;
Herbert Xuca681452007-10-17 21:35:15 -0700604 case XFRM_MODE_TRANSPORT:
605 break;
606 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700608 break;
Herbert Xuca681452007-10-17 21:35:15 -0700609 default:
610 goto error;
611 }
Herbert Xu38320c72008-01-28 19:35:05 -0800612
613 align = ALIGN(crypto_aead_blocksize(aead), 4);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200614 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
616error:
Herbert Xu38320c72008-01-28 19:35:05 -0800617 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618}
619
Steffen Klassertd5860c52014-03-14 07:28:07 +0100620static int esp6_rcv_cb(struct sk_buff *skb, int err)
621{
622 return 0;
623}
624
Ian Morriscc24bec2014-08-24 21:53:11 +0100625static const struct xfrm_type esp6_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 .description = "ESP6",
Ian Morriscc24bec2014-08-24 21:53:11 +0100627 .owner = THIS_MODULE,
628 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700629 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 .init_state = esp6_init_state,
631 .destructor = esp6_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700632 .get_mtu = esp6_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 .input = esp6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700634 .output = esp6_output,
635 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636};
637
Steffen Klassertd5860c52014-03-14 07:28:07 +0100638static struct xfrm6_protocol esp6_protocol = {
639 .handler = xfrm6_rcv,
640 .cb_handler = esp6_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 .err_handler = esp6_err,
Steffen Klassertd5860c52014-03-14 07:28:07 +0100642 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643};
644
645static int __init esp6_init(void)
646{
647 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000648 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 return -EAGAIN;
650 }
Steffen Klassertd5860c52014-03-14 07:28:07 +0100651 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000652 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 xfrm_unregister_type(&esp6_type, AF_INET6);
654 return -EAGAIN;
655 }
656
657 return 0;
658}
659
660static void __exit esp6_fini(void)
661{
Steffen Klassertd5860c52014-03-14 07:28:07 +0100662 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000663 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000665 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666}
667
668module_init(esp6_init);
669module_exit(esp6_fini);
670
671MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700672MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);