blob: 6a924be66e37384b5f98fe223109e2464b4cb250 [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
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
Herbert Xu000ae7b2015-05-27 16:03:47 +080079 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
Herbert Xu38320c72008-01-28 19:35:05 -080080 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
Herbert Xu38320c72008-01-28 19:35:05 -080099static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
100{
101 struct aead_request *req;
102
103 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
104 crypto_tfm_ctx_alignment());
105 aead_request_set_tfm(req, aead);
106 return req;
107}
108
109static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
110 struct aead_request *req)
111{
112 return (void *)ALIGN((unsigned long)(req + 1) +
113 crypto_aead_reqsize(aead),
114 __alignof__(struct scatterlist));
115}
116
Herbert Xu38320c72008-01-28 19:35:05 -0800117static void esp_output_done(struct crypto_async_request *base, int err)
118{
119 struct sk_buff *skb = base->data;
120
121 kfree(ESP_SKB_CB(skb)->tmp);
122 xfrm_output_resume(skb, err);
123}
124
Herbert Xu000ae7b2015-05-27 16:03:47 +0800125/* Move ESP header back into place. */
126static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
127{
128 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
129 void *tmp = ESP_SKB_CB(skb)->tmp;
130 __be32 *seqhi = esp_tmp_seqhi(tmp);
131
132 esph->seq_no = esph->spi;
133 esph->spi = *seqhi;
134}
135
136static void esp_output_restore_header(struct sk_buff *skb)
137{
138 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
139}
140
141static void esp_output_done_esn(struct crypto_async_request *base, int err)
142{
143 struct sk_buff *skb = base->data;
144
145 esp_output_restore_header(skb);
146 esp_output_done(base, err);
147}
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
150{
151 int err;
Herbert Xu87bdc482007-10-10 15:45:25 -0700152 struct ip_esp_hdr *esph;
Herbert Xu38320c72008-01-28 19:35:05 -0800153 struct crypto_aead *aead;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800154 struct aead_request *req;
Herbert Xu38320c72008-01-28 19:35:05 -0800155 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 struct sk_buff *trailer;
Herbert Xu38320c72008-01-28 19:35:05 -0800157 void *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 int blksize;
159 int clen;
160 int alen;
Martin Willi040253c2010-12-08 04:37:51 +0000161 int plen;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800162 int ivlen;
Martin Willi040253c2010-12-08 04:37:51 +0000163 int tfclen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000165 int assoclen;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000166 int seqhilen;
Herbert Xu38320c72008-01-28 19:35:05 -0800167 u8 *iv;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700168 u8 *tail;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000169 __be32 *seqhi;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800170 __be64 seqno;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Herbert Xu7b277b12007-10-10 15:44:06 -0700172 /* skb is pure payload to encrypt */
Mathias Krause1c5ad132013-10-18 12:09:05 +0200173 aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800174 alen = crypto_aead_authsize(aead);
Herbert Xu000ae7b2015-05-27 16:03:47 +0800175 ivlen = crypto_aead_ivsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Martin Willi040253c2010-12-08 04:37:51 +0000177 tfclen = 0;
178 if (x->tfcpad) {
179 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
180 u32 padto;
181
182 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
183 if (skb->len < padto)
184 tfclen = padto - skb->len;
185 }
Herbert Xu38320c72008-01-28 19:35:05 -0800186 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Martin Willi040253c2010-12-08 04:37:51 +0000187 clen = ALIGN(skb->len + 2 + tfclen, blksize);
Martin Willi040253c2010-12-08 04:37:51 +0000188 plen = clen - skb->len - tfclen;
Herbert Xu38320c72008-01-28 19:35:05 -0800189
Martin Willi040253c2010-12-08 04:37:51 +0000190 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
191 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800193 nfrags = err;
194
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000195 assoclen = sizeof(*esph);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000196 seqhilen = 0;
197
198 if (x->props.flags & XFRM_STATE_ESN) {
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000199 seqhilen += sizeof(__be32);
200 assoclen += seqhilen;
201 }
202
Herbert Xu000ae7b2015-05-27 16:03:47 +0800203 tmp = esp_alloc_tmp(aead, nfrags, 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 Xu000ae7b2015-05-27 16:03:47 +0800211 req = esp_tmp_req(aead, iv);
212 sg = esp_req_sg(aead, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 /* Fill padding... */
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700215 tail = skb_tail_pointer(trailer);
Martin Willi040253c2010-12-08 04:37:51 +0000216 if (tfclen) {
217 memset(tail, 0, tfclen);
218 tail += tfclen;
219 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 do {
221 int i;
Martin Willi040253c2010-12-08 04:37:51 +0000222 for (i = 0; i < plen - 2; i++)
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700223 tail[i] = i + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 } while (0);
Martin Willi040253c2010-12-08 04:37:51 +0000225 tail[plen - 2] = plen - 2;
226 tail[plen - 1] = *skb_mac_header(skb);
Herbert Xu38320c72008-01-28 19:35:05 -0800227 pskb_put(skb, trailer, clen - skb->len + alen);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Herbert Xu7b277b12007-10-10 15:44:06 -0700229 skb_push(skb, -skb_network_offset(skb));
Herbert Xu87bdc482007-10-10 15:45:25 -0700230 esph = ip_esp_hdr(skb);
Herbert Xu007f0212007-10-09 13:25:59 -0700231 *skb_mac_header(skb) = IPPROTO_ESP;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
Steffen Klassert1ce36442011-03-08 00:06:31 +0000233 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Herbert Xu000ae7b2015-05-27 16:03:47 +0800235 aead_request_set_callback(req, 0, esp_output_done, skb);
236
237 /* For ESN we move the header forward by 4 bytes to
238 * accomodate the high bits. We will move it back after
239 * encryption.
240 */
241 if ((x->props.flags & XFRM_STATE_ESN)) {
242 esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
243 *seqhi = esph->spi;
244 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
245 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
246 }
247
248 esph->spi = x->id.spi;
249
Herbert Xu38320c72008-01-28 19:35:05 -0800250 sg_init_table(sg, nfrags);
Jason A. Donenfeld753b04d2017-06-04 04:16:23 +0200251 err = skb_to_sgvec(skb, sg,
252 (unsigned char *)esph - skb->data,
253 assoclen + ivlen + clen + alen);
254 if (unlikely(err < 0))
255 goto error;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000256
Herbert Xu000ae7b2015-05-27 16:03:47 +0800257 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
258 aead_request_set_ad(req, assoclen);
Herbert Xub7c65382007-10-09 13:33:35 -0700259
Herbert Xu000ae7b2015-05-27 16:03:47 +0800260 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
261 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
262
263 memset(iv, 0, ivlen);
264 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
265 min(ivlen, 8));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
Herbert Xu38320c72008-01-28 19:35:05 -0800267 ESP_SKB_CB(skb)->tmp = tmp;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800268 err = crypto_aead_encrypt(req);
269
270 switch (err) {
271 case -EINPROGRESS:
Herbert Xu38320c72008-01-28 19:35:05 -0800272 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
Herbert Xu000ae7b2015-05-27 16:03:47 +0800274 case -EBUSY:
Herbert Xu38320c72008-01-28 19:35:05 -0800275 err = NET_XMIT_DROP;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800276 break;
277
278 case 0:
279 if ((x->props.flags & XFRM_STATE_ESN))
280 esp_output_restore_header(skb);
281 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
Herbert Xu38320c72008-01-28 19:35:05 -0800283 kfree(tmp);
Herbert Xub7c65382007-10-09 13:33:35 -0700284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285error:
286 return err;
287}
288
Herbert Xu38320c72008-01-28 19:35:05 -0800289static int esp_input_done2(struct sk_buff *skb, int err)
290{
291 struct xfrm_state *x = xfrm_input_state(skb);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200292 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800293 int alen = crypto_aead_authsize(aead);
294 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
295 int elen = skb->len - hlen;
296 int hdr_len = skb_network_header_len(skb);
297 int padlen;
298 u8 nexthdr[2];
299
300 kfree(ESP_SKB_CB(skb)->tmp);
301
302 if (unlikely(err))
303 goto out;
304
305 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
306 BUG();
307
308 err = -EINVAL;
309 padlen = nexthdr[0];
310 if (padlen + 2 + alen >= elen) {
Joe Perchesba7a46f2014-11-11 10:59:17 -0800311 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
312 padlen + 2, elen - alen);
Herbert Xu38320c72008-01-28 19:35:05 -0800313 goto out;
314 }
315
316 /* ... check padding bits here. Silly. :-) */
317
318 pskb_trim(skb, skb->len - alen - padlen - 2);
319 __skb_pull(skb, hlen);
Li RongQinga9403f82013-01-08 15:41:12 +0800320 if (x->props.mode == XFRM_MODE_TUNNEL)
321 skb_reset_transport_header(skb);
322 else
323 skb_set_transport_header(skb, -hdr_len);
Herbert Xu38320c72008-01-28 19:35:05 -0800324
325 err = nexthdr[1];
326
327 /* RFC4303: Drop dummy packets without any error */
328 if (err == IPPROTO_NONE)
329 err = -EINVAL;
330
331out:
332 return err;
333}
334
335static void esp_input_done(struct crypto_async_request *base, int err)
336{
337 struct sk_buff *skb = base->data;
338
339 xfrm_input_resume(skb, esp_input_done2(skb, err));
340}
341
Herbert Xu000ae7b2015-05-27 16:03:47 +0800342static void esp_input_restore_header(struct sk_buff *skb)
343{
344 esp_restore_header(skb, 0);
345 __skb_pull(skb, 4);
346}
347
348static void esp_input_done_esn(struct crypto_async_request *base, int err)
349{
350 struct sk_buff *skb = base->data;
351
352 esp_input_restore_header(skb);
353 esp_input_done(base, err);
354}
355
Herbert Xue6956332006-04-01 00:52:46 -0800356static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357{
Herbert Xu87bdc482007-10-10 15:45:25 -0700358 struct ip_esp_hdr *esph;
Mathias Krause1c5ad132013-10-18 12:09:05 +0200359 struct crypto_aead *aead = x->data;
Herbert Xu38320c72008-01-28 19:35:05 -0800360 struct aead_request *req;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 struct sk_buff *trailer;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800362 int ivlen = crypto_aead_ivsize(aead);
363 int elen = skb->len - sizeof(*esph) - ivlen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 int nfrags;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000365 int assoclen;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000366 int seqhilen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 int ret = 0;
Herbert Xu38320c72008-01-28 19:35:05 -0800368 void *tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000369 __be32 *seqhi;
Herbert Xu38320c72008-01-28 19:35:05 -0800370 u8 *iv;
371 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
Herbert Xu000ae7b2015-05-27 16:03:47 +0800373 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700375 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 }
377
Herbert Xu38320c72008-01-28 19:35:05 -0800378 if (elen <= 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 ret = -EINVAL;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700380 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 }
382
Ian Morrise5d08d72014-11-23 21:28:43 +0000383 nfrags = skb_cow_data(skb, 0, &trailer);
384 if (nfrags < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 ret = -EINVAL;
386 goto out;
387 }
388
Herbert Xu38320c72008-01-28 19:35:05 -0800389 ret = -ENOMEM;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000390
391 assoclen = sizeof(*esph);
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000392 seqhilen = 0;
393
394 if (x->props.flags & XFRM_STATE_ESN) {
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000395 seqhilen += sizeof(__be32);
396 assoclen += seqhilen;
397 }
398
Herbert Xu000ae7b2015-05-27 16:03:47 +0800399 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800400 if (!tmp)
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800401 goto out;
402
Herbert Xu38320c72008-01-28 19:35:05 -0800403 ESP_SKB_CB(skb)->tmp = tmp;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000404 seqhi = esp_tmp_seqhi(tmp);
405 iv = esp_tmp_iv(aead, tmp, seqhilen);
Herbert Xu38320c72008-01-28 19:35:05 -0800406 req = esp_tmp_req(aead, iv);
Herbert Xu000ae7b2015-05-27 16:03:47 +0800407 sg = esp_req_sg(aead, req);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408
Herbert Xu38320c72008-01-28 19:35:05 -0800409 skb->ip_summed = CHECKSUM_NONE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410
Herbert Xu38320c72008-01-28 19:35:05 -0800411 esph = (struct ip_esp_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Herbert Xu000ae7b2015-05-27 16:03:47 +0800413 aead_request_set_callback(req, 0, esp_input_done, skb);
414
415 /* For ESN we move the header forward by 4 bytes to
416 * accomodate the high bits. We will move it back after
417 * decryption.
418 */
419 if ((x->props.flags & XFRM_STATE_ESN)) {
420 esph = (void *)skb_push(skb, 4);
421 *seqhi = esph->spi;
422 esph->spi = esph->seq_no;
Tobias Brunnera55e2382016-11-29 17:05:25 +0100423 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
Herbert Xu000ae7b2015-05-27 16:03:47 +0800424 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
425 }
Thomas Graf95a02cf2007-12-10 16:53:29 -0800426
Herbert Xu38320c72008-01-28 19:35:05 -0800427 sg_init_table(sg, nfrags);
Jason A. Donenfeld753b04d2017-06-04 04:16:23 +0200428 ret = skb_to_sgvec(skb, sg, 0, skb->len);
429 if (unlikely(ret < 0))
430 goto out;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000431
Herbert Xu000ae7b2015-05-27 16:03:47 +0800432 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
433 aead_request_set_ad(req, assoclen);
Herbert Xu38320c72008-01-28 19:35:05 -0800434
435 ret = crypto_aead_decrypt(req);
436 if (ret == -EINPROGRESS)
437 goto out;
438
Herbert Xu000ae7b2015-05-27 16:03:47 +0800439 if ((x->props.flags & XFRM_STATE_ESN))
440 esp_input_restore_header(skb);
441
Herbert Xu38320c72008-01-28 19:35:05 -0800442 ret = esp_input_done2(skb, ret);
443
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return ret;
446}
447
Patrick McHardyc5c25232007-04-09 11:47:18 -0700448static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200450 struct crypto_aead *aead = x->data;
451 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000452 unsigned int net_adj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
Benjamin Poirier91657ea2012-05-24 11:32:38 +0000454 if (x->props.mode != XFRM_MODE_TUNNEL)
455 net_adj = sizeof(struct ipv6hdr);
456 else
457 net_adj = 0;
Patrick McHardyc5c25232007-04-09 11:47:18 -0700458
Mathias Krause1c5ad132013-10-18 12:09:05 +0200459 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
Mathias Krause123b0d12013-10-18 12:09:04 +0200460 net_adj) & ~(blksize - 1)) + net_adj - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461}
462
Steffen Klassertd5860c52014-03-14 07:28:07 +0100463static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
464 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800466 struct net *net = dev_net(skb->dev);
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000467 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
Herbert Xu87bdc482007-10-10 15:45:25 -0700468 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 struct xfrm_state *x;
470
Steffen Klassertb3b2b9e2013-09-10 13:43:09 +0200471 if (type != ICMPV6_PKT_TOOBIG &&
David S. Millerec18d9a2012-07-12 00:25:15 -0700472 type != NDISC_REDIRECT)
Steffen Klassertd5860c52014-03-14 07:28:07 +0100473 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474
Eric Dumazetb71d1d42011-04-22 04:53:02 +0000475 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
476 esph->spi, IPPROTO_ESP, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 if (!x)
Steffen Klassertd5860c52014-03-14 07:28:07 +0100478 return 0;
David S. Millerec18d9a2012-07-12 00:25:15 -0700479
480 if (type == NDISC_REDIRECT)
Duan Jiongb55b76b2013-09-04 19:44:21 +0800481 ip6_redirect(skb, net, skb->dev->ifindex, 0);
David S. Millerec18d9a2012-07-12 00:25:15 -0700482 else
483 ip6_update_pmtu(skb, net, info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 xfrm_state_put(x);
Steffen Klassertd5860c52014-03-14 07:28:07 +0100485
486 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487}
488
489static void esp6_destroy(struct xfrm_state *x)
490{
Mathias Krause1c5ad132013-10-18 12:09:05 +0200491 struct crypto_aead *aead = x->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492
Mathias Krause1c5ad132013-10-18 12:09:05 +0200493 if (!aead)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 return;
495
Mathias Krause1c5ad132013-10-18 12:09:05 +0200496 crypto_free_aead(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497}
498
Herbert Xu1a6509d2008-01-28 19:37:29 -0800499static int esp_init_aead(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500{
Herbert Xu000ae7b2015-05-27 16:03:47 +0800501 char aead_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu1a6509d2008-01-28 19:37:29 -0800502 struct crypto_aead *aead;
503 int err;
504
Herbert Xu000ae7b2015-05-27 16:03:47 +0800505 err = -ENAMETOOLONG;
506 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
507 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
508 goto error;
509
510 aead = crypto_alloc_aead(aead_name, 0, 0);
Herbert Xu1a6509d2008-01-28 19:37:29 -0800511 err = PTR_ERR(aead);
512 if (IS_ERR(aead))
513 goto error;
514
Mathias Krause1c5ad132013-10-18 12:09:05 +0200515 x->data = aead;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800516
517 err = crypto_aead_setkey(aead, x->aead->alg_key,
518 (x->aead->alg_key_len + 7) / 8);
519 if (err)
520 goto error;
521
522 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
523 if (err)
524 goto error;
525
526error:
527 return err;
528}
529
530static int esp_init_authenc(struct xfrm_state *x)
531{
Herbert Xu38320c72008-01-28 19:35:05 -0800532 struct crypto_aead *aead;
533 struct crypto_authenc_key_param *param;
534 struct rtattr *rta;
535 char *key;
536 char *p;
537 char authenc_name[CRYPTO_MAX_ALG_NAME];
Herbert Xu38320c72008-01-28 19:35:05 -0800538 unsigned int keylen;
539 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Herbert Xu1a6509d2008-01-28 19:37:29 -0800541 err = -EINVAL;
Ian Morris63159f22015-03-29 14:00:04 +0100542 if (!x->ealg)
Herbert Xu1a6509d2008-01-28 19:37:29 -0800543 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544
Herbert Xu1a6509d2008-01-28 19:37:29 -0800545 err = -ENAMETOOLONG;
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000546
547 if ((x->props.flags & XFRM_STATE_ESN)) {
548 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu000ae7b2015-05-27 16:03:47 +0800549 "%s%sauthencesn(%s,%s)%s",
550 x->geniv ?: "", x->geniv ? "(" : "",
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000551 x->aalg ? x->aalg->alg_name : "digest_null",
Herbert Xu000ae7b2015-05-27 16:03:47 +0800552 x->ealg->alg_name,
553 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000554 goto error;
555 } else {
556 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
Herbert Xu000ae7b2015-05-27 16:03:47 +0800557 "%s%sauthenc(%s,%s)%s",
558 x->geniv ?: "", x->geniv ? "(" : "",
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000559 x->aalg ? x->aalg->alg_name : "digest_null",
Herbert Xu000ae7b2015-05-27 16:03:47 +0800560 x->ealg->alg_name,
561 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
Steffen Klassertd212a4c2011-03-08 00:07:51 +0000562 goto error;
563 }
Herbert Xu38320c72008-01-28 19:35:05 -0800564
565 aead = crypto_alloc_aead(authenc_name, 0, 0);
566 err = PTR_ERR(aead);
567 if (IS_ERR(aead))
568 goto error;
569
Mathias Krause1c5ad132013-10-18 12:09:05 +0200570 x->data = aead;
Herbert Xu38320c72008-01-28 19:35:05 -0800571
572 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
573 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
574 err = -ENOMEM;
575 key = kmalloc(keylen, GFP_KERNEL);
576 if (!key)
577 goto error;
578
579 p = key;
580 rta = (void *)p;
581 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
582 rta->rta_len = RTA_LENGTH(sizeof(*param));
583 param = RTA_DATA(rta);
584 p += RTA_SPACE(sizeof(*param));
585
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 if (x->aalg) {
587 struct xfrm_algo_desc *aalg_desc;
588
Herbert Xu38320c72008-01-28 19:35:05 -0800589 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
590 p += (x->aalg->alg_key_len + 7) / 8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
593 BUG_ON(!aalg_desc);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900594
Herbert Xu38320c72008-01-28 19:35:05 -0800595 err = -EINVAL;
Joe Perches45083492014-11-05 15:36:08 -0800596 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
Herbert Xu38320c72008-01-28 19:35:05 -0800597 crypto_aead_authsize(aead)) {
Joe Perches45083492014-11-05 15:36:08 -0800598 pr_info("ESP: %s digestsize %u != %hu\n",
599 x->aalg->alg_name,
600 crypto_aead_authsize(aead),
601 aalg_desc->uinfo.auth.icv_fullbits / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800602 goto free_key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900604
Herbert Xu38320c72008-01-28 19:35:05 -0800605 err = crypto_aead_setauthsize(
Martin Willi8f8a0882009-11-25 00:29:53 +0000606 aead, x->aalg->alg_trunc_len / 8);
Herbert Xu38320c72008-01-28 19:35:05 -0800607 if (err)
608 goto free_key;
609 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900610
Herbert Xu38320c72008-01-28 19:35:05 -0800611 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
612 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
613
614 err = crypto_aead_setkey(aead, key, keylen);
615
616free_key:
617 kfree(key);
618
Herbert Xu1a6509d2008-01-28 19:37:29 -0800619error:
620 return err;
621}
622
623static int esp6_init_state(struct xfrm_state *x)
624{
Herbert Xu1a6509d2008-01-28 19:37:29 -0800625 struct crypto_aead *aead;
626 u32 align;
627 int err;
628
629 if (x->encap)
630 return -EINVAL;
631
Mathias Krause1c5ad132013-10-18 12:09:05 +0200632 x->data = NULL;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800633
634 if (x->aead)
635 err = esp_init_aead(x);
636 else
637 err = esp_init_authenc(x);
638
Herbert Xu38320c72008-01-28 19:35:05 -0800639 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 goto error;
Herbert Xu38320c72008-01-28 19:35:05 -0800641
Mathias Krause1c5ad132013-10-18 12:09:05 +0200642 aead = x->data;
Herbert Xu1a6509d2008-01-28 19:37:29 -0800643
Herbert Xu38320c72008-01-28 19:35:05 -0800644 x->props.header_len = sizeof(struct ip_esp_hdr) +
645 crypto_aead_ivsize(aead);
Herbert Xuca681452007-10-17 21:35:15 -0700646 switch (x->props.mode) {
647 case XFRM_MODE_BEET:
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700648 if (x->sel.family != AF_INET6)
649 x->props.header_len += IPV4_BEET_PHMAXLEN +
Ian Morris67ba4152014-08-24 21:53:10 +0100650 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
Joakim Koskelaabf5cdb2008-08-06 02:40:25 -0700651 break;
Herbert Xuca681452007-10-17 21:35:15 -0700652 case XFRM_MODE_TRANSPORT:
653 break;
654 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700656 break;
Herbert Xuca681452007-10-17 21:35:15 -0700657 default:
658 goto error;
659 }
Herbert Xu38320c72008-01-28 19:35:05 -0800660
661 align = ALIGN(crypto_aead_blocksize(aead), 4);
Mathias Krause1c5ad132013-10-18 12:09:05 +0200662 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663
664error:
Herbert Xu38320c72008-01-28 19:35:05 -0800665 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666}
667
Steffen Klassertd5860c52014-03-14 07:28:07 +0100668static int esp6_rcv_cb(struct sk_buff *skb, int err)
669{
670 return 0;
671}
672
Ian Morriscc24bec2014-08-24 21:53:11 +0100673static const struct xfrm_type esp6_type = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 .description = "ESP6",
Ian Morriscc24bec2014-08-24 21:53:11 +0100675 .owner = THIS_MODULE,
676 .proto = IPPROTO_ESP,
Herbert Xu436a0a42007-10-08 17:25:53 -0700677 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 .init_state = esp6_init_state,
679 .destructor = esp6_destroy,
Patrick McHardyc5c25232007-04-09 11:47:18 -0700680 .get_mtu = esp6_get_mtu,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 .input = esp6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700682 .output = esp6_output,
683 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684};
685
Steffen Klassertd5860c52014-03-14 07:28:07 +0100686static struct xfrm6_protocol esp6_protocol = {
687 .handler = xfrm6_rcv,
688 .cb_handler = esp6_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 .err_handler = esp6_err,
Steffen Klassertd5860c52014-03-14 07:28:07 +0100690 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691};
692
693static int __init esp6_init(void)
694{
695 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000696 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 return -EAGAIN;
698 }
Steffen Klassertd5860c52014-03-14 07:28:07 +0100699 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000700 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 xfrm_unregister_type(&esp6_type, AF_INET6);
702 return -EAGAIN;
703 }
704
705 return 0;
706}
707
708static void __exit esp6_fini(void)
709{
Steffen Klassertd5860c52014-03-14 07:28:07 +0100710 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000711 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000713 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714}
715
716module_init(esp6_init);
717module_exit(esp6_fini);
718
719MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700720MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);