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1/*
2 * Copyright (C)2002 USAGI/WIDE Project
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 *
17 * Authors
18 *
19 * Mitsuru KANDA @USAGI : IPv6 Support
20 * Kazunori MIYAZAWA @USAGI :
21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
22 *
23 * This file is derived from net/ipv4/esp.c
24 */
25
26#define pr_fmt(fmt) "IPv6: " fmt
27
28#include <crypto/aead.h>
29#include <crypto/authenc.h>
30#include <linux/err.h>
31#include <linux/module.h>
32#include <net/ip.h>
33#include <net/xfrm.h>
34#include <net/esp.h>
35#include <linux/scatterlist.h>
36#include <linux/kernel.h>
37#include <linux/pfkeyv2.h>
38#include <linux/random.h>
39#include <linux/slab.h>
40#include <linux/spinlock.h>
41#include <net/ip6_route.h>
42#include <net/icmp.h>
43#include <net/ipv6.h>
44#include <net/protocol.h>
45#include <linux/icmpv6.h>
46
47struct 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
54static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
55
56/*
57 * Allocate an AEAD request structure with extra space for SG and IV.
58 *
59 * 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.
62 *
63 * TODO: Use spare space in skb for this where possible.
64 */
65static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
66{
67 unsigned int len;
68
69 len = seqihlen;
70
71 len += crypto_aead_ivsize(aead);
72
73 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
87static 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)
93{
94 return crypto_aead_ivsize(aead) ?
95 PTR_ALIGN((u8 *)tmp + seqhilen,
96 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
97}
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
144static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
145{
146 int err;
147 struct ip_esp_hdr *esph;
148 struct crypto_aead *aead;
149 struct aead_givcrypt_request *req;
150 struct scatterlist *sg;
151 struct scatterlist *asg;
152 struct sk_buff *trailer;
153 void *tmp;
154 int blksize;
155 int clen;
156 int alen;
157 int plen;
158 int tfclen;
159 int nfrags;
160 int assoclen;
161 int sglists;
162 int seqhilen;
163 u8 *iv;
164 u8 *tail;
165 __be32 *seqhi;
166
167 /* skb is pure payload to encrypt */
168 aead = x->data;
169 alen = crypto_aead_authsize(aead);
170
171 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 }
180 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
181 clen = ALIGN(skb->len + 2 + tfclen, blksize);
182 plen = clen - skb->len - tfclen;
183
184 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
185 if (err < 0)
186 goto error;
187 nfrags = err;
188
189 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);
200 if (!tmp) {
201 err = -ENOMEM;
202 goto error;
203 }
204
205 seqhi = esp_tmp_seqhi(tmp);
206 iv = esp_tmp_iv(aead, tmp, seqhilen);
207 req = esp_tmp_givreq(aead, iv);
208 asg = esp_givreq_sg(aead, req);
209 sg = asg + sglists;
210
211 /* Fill padding... */
212 tail = skb_tail_pointer(trailer);
213 if (tfclen) {
214 memset(tail, 0, tfclen);
215 tail += tfclen;
216 }
217 do {
218 int i;
219 for (i = 0; i < plen - 2; i++)
220 tail[i] = i + 1;
221 } while (0);
222 tail[plen - 2] = plen - 2;
223 tail[plen - 1] = *skb_mac_header(skb);
224 pskb_put(skb, trailer, clen - skb->len + alen);
225
226 skb_push(skb, -skb_network_offset(skb));
227 esph = ip_esp_hdr(skb);
228 *skb_mac_header(skb) = IPPROTO_ESP;
229
230 esph->spi = x->id.spi;
231 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
232
233 sg_init_table(sg, nfrags);
234 skb_to_sgvec(skb, sg,
235 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
236 clen + alen);
237
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));
246
247 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
248 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
249 aead_givcrypt_set_assoc(req, asg, assoclen);
250 aead_givcrypt_set_giv(req, esph->enc_data,
251 XFRM_SKB_CB(skb)->seq.output.low);
252
253 ESP_SKB_CB(skb)->tmp = tmp;
254 err = crypto_aead_givencrypt(req);
255 if (err == -EINPROGRESS)
256 goto error;
257
258 if (err == -EBUSY)
259 err = NET_XMIT_DROP;
260
261 kfree(tmp);
262
263error:
264 return err;
265}
266
267static int esp_input_done2(struct sk_buff *skb, int err)
268{
269 struct xfrm_state *x = xfrm_input_state(skb);
270 struct crypto_aead *aead = x->data;
271 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) {
289 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
290 "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
291 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);
298 if (x->props.mode == XFRM_MODE_TUNNEL)
299 skb_reset_transport_header(skb);
300 else
301 skb_set_transport_header(skb, -hdr_len);
302
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
320static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
321{
322 struct ip_esp_hdr *esph;
323 struct crypto_aead *aead = x->data;
324 struct aead_request *req;
325 struct sk_buff *trailer;
326 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
327 int nfrags;
328 int assoclen;
329 int sglists;
330 int seqhilen;
331 int ret = 0;
332 void *tmp;
333 __be32 *seqhi;
334 u8 *iv;
335 struct scatterlist *sg;
336 struct scatterlist *asg;
337
338 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
339 ret = -EINVAL;
340 goto out;
341 }
342
343 if (elen <= 0) {
344 ret = -EINVAL;
345 goto out;
346 }
347
348 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
349 ret = -EINVAL;
350 goto out;
351 }
352
353 ret = -ENOMEM;
354
355 assoclen = sizeof(*esph);
356 sglists = 1;
357 seqhilen = 0;
358
359 if (x->props.flags & XFRM_STATE_ESN) {
360 sglists += 2;
361 seqhilen += sizeof(__be32);
362 assoclen += seqhilen;
363 }
364
365 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
366 if (!tmp)
367 goto out;
368
369 ESP_SKB_CB(skb)->tmp = tmp;
370 seqhi = esp_tmp_seqhi(tmp);
371 iv = esp_tmp_iv(aead, tmp, seqhilen);
372 req = esp_tmp_req(aead, iv);
373 asg = esp_req_sg(aead, req);
374 sg = asg + sglists;
375
376 skb->ip_summed = CHECKSUM_NONE;
377
378 esph = (struct ip_esp_hdr *)skb->data;
379
380 /* Get ivec. This can be wrong, check against another impls. */
381 iv = esph->enc_data;
382
383 sg_init_table(sg, nfrags);
384 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
385
386 if ((x->props.flags & XFRM_STATE_ESN)) {
387 sg_init_table(asg, 3);
388 sg_set_buf(asg, &esph->spi, sizeof(__be32));
389 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
390 sg_set_buf(asg + 1, seqhi, seqhilen);
391 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
392 } else
393 sg_init_one(asg, esph, sizeof(*esph));
394
395 aead_request_set_callback(req, 0, esp_input_done, skb);
396 aead_request_set_crypt(req, sg, sg, elen, iv);
397 aead_request_set_assoc(req, asg, assoclen);
398
399 ret = crypto_aead_decrypt(req);
400 if (ret == -EINPROGRESS)
401 goto out;
402
403 ret = esp_input_done2(skb, ret);
404
405out:
406 return ret;
407}
408
409static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
410{
411 struct crypto_aead *aead = x->data;
412 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
413 unsigned int net_adj;
414
415 if (x->props.mode != XFRM_MODE_TUNNEL)
416 net_adj = sizeof(struct ipv6hdr);
417 else
418 net_adj = 0;
419
420 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
421 net_adj) & ~(blksize - 1)) + net_adj - 2;
422}
423
424static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
425 u8 type, u8 code, int offset, __be32 info)
426{
427 struct net *net = dev_net(skb->dev);
428 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
429 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
430 struct xfrm_state *x;
431
432 if (type != ICMPV6_PKT_TOOBIG &&
433 type != NDISC_REDIRECT)
434 return 0;
435
436 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
437 esph->spi, IPPROTO_ESP, AF_INET6);
438 if (!x)
439 return 0;
440
441 if (type == NDISC_REDIRECT)
442 ip6_redirect(skb, net, skb->dev->ifindex, 0);
443 else
444 ip6_update_pmtu(skb, net, info, 0, 0);
445 xfrm_state_put(x);
446
447 return 0;
448}
449
450static void esp6_destroy(struct xfrm_state *x)
451{
452 struct crypto_aead *aead = x->data;
453
454 if (!aead)
455 return;
456
457 crypto_free_aead(aead);
458}
459
460static int esp_init_aead(struct xfrm_state *x)
461{
462 struct crypto_aead *aead;
463 int err;
464
465 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
466 err = PTR_ERR(aead);
467 if (IS_ERR(aead))
468 goto error;
469
470 x->data = aead;
471
472 err = crypto_aead_setkey(aead, x->aead->alg_key,
473 (x->aead->alg_key_len + 7) / 8);
474 if (err)
475 goto error;
476
477 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
478 if (err)
479 goto error;
480
481error:
482 return err;
483}
484
485static int esp_init_authenc(struct xfrm_state *x)
486{
487 struct crypto_aead *aead;
488 struct crypto_authenc_key_param *param;
489 struct rtattr *rta;
490 char *key;
491 char *p;
492 char authenc_name[CRYPTO_MAX_ALG_NAME];
493 unsigned int keylen;
494 int err;
495
496 err = -EINVAL;
497 if (x->ealg == NULL)
498 goto error;
499
500 err = -ENAMETOOLONG;
501
502 if ((x->props.flags & XFRM_STATE_ESN)) {
503 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
504 "authencesn(%s,%s)",
505 x->aalg ? x->aalg->alg_name : "digest_null",
506 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
507 goto error;
508 } else {
509 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
510 "authenc(%s,%s)",
511 x->aalg ? x->aalg->alg_name : "digest_null",
512 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
513 goto error;
514 }
515
516 aead = crypto_alloc_aead(authenc_name, 0, 0);
517 err = PTR_ERR(aead);
518 if (IS_ERR(aead))
519 goto error;
520
521 x->data = aead;
522
523 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
524 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
525 err = -ENOMEM;
526 key = kmalloc(keylen, GFP_KERNEL);
527 if (!key)
528 goto error;
529
530 p = key;
531 rta = (void *)p;
532 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
533 rta->rta_len = RTA_LENGTH(sizeof(*param));
534 param = RTA_DATA(rta);
535 p += RTA_SPACE(sizeof(*param));
536
537 if (x->aalg) {
538 struct xfrm_algo_desc *aalg_desc;
539
540 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
541 p += (x->aalg->alg_key_len + 7) / 8;
542
543 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
544 BUG_ON(!aalg_desc);
545
546 err = -EINVAL;
547 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
548 crypto_aead_authsize(aead)) {
549 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
550 x->aalg->alg_name,
551 crypto_aead_authsize(aead),
552 aalg_desc->uinfo.auth.icv_fullbits/8);
553 goto free_key;
554 }
555
556 err = crypto_aead_setauthsize(
557 aead, x->aalg->alg_trunc_len / 8);
558 if (err)
559 goto free_key;
560 }
561
562 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
563 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
564
565 err = crypto_aead_setkey(aead, key, keylen);
566
567free_key:
568 kfree(key);
569
570error:
571 return err;
572}
573
574static int esp6_init_state(struct xfrm_state *x)
575{
576 struct crypto_aead *aead;
577 u32 align;
578 int err;
579
580 if (x->encap)
581 return -EINVAL;
582
583 x->data = NULL;
584
585 if (x->aead)
586 err = esp_init_aead(x);
587 else
588 err = esp_init_authenc(x);
589
590 if (err)
591 goto error;
592
593 aead = x->data;
594
595 x->props.header_len = sizeof(struct ip_esp_hdr) +
596 crypto_aead_ivsize(aead);
597 switch (x->props.mode) {
598 case XFRM_MODE_BEET:
599 if (x->sel.family != AF_INET6)
600 x->props.header_len += IPV4_BEET_PHMAXLEN +
601 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
602 break;
603 case XFRM_MODE_TRANSPORT:
604 break;
605 case XFRM_MODE_TUNNEL:
606 x->props.header_len += sizeof(struct ipv6hdr);
607 break;
608 default:
609 goto error;
610 }
611
612 align = ALIGN(crypto_aead_blocksize(aead), 4);
613 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
614
615error:
616 return err;
617}
618
619static int esp6_rcv_cb(struct sk_buff *skb, int err)
620{
621 return 0;
622}
623
624static const struct xfrm_type esp6_type =
625{
626 .description = "ESP6",
627 .owner = THIS_MODULE,
628 .proto = IPPROTO_ESP,
629 .flags = XFRM_TYPE_REPLAY_PROT,
630 .init_state = esp6_init_state,
631 .destructor = esp6_destroy,
632 .get_mtu = esp6_get_mtu,
633 .input = esp6_input,
634 .output = esp6_output,
635 .hdr_offset = xfrm6_find_1stfragopt,
636};
637
638static struct xfrm6_protocol esp6_protocol = {
639 .handler = xfrm6_rcv,
640 .cb_handler = esp6_rcv_cb,
641 .err_handler = esp6_err,
642 .priority = 0,
643};
644
645static int __init esp6_init(void)
646{
647 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
648 pr_info("%s: can't add xfrm type\n", __func__);
649 return -EAGAIN;
650 }
651 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
652 pr_info("%s: can't add protocol\n", __func__);
653 xfrm_unregister_type(&esp6_type, AF_INET6);
654 return -EAGAIN;
655 }
656
657 return 0;
658}
659
660static void __exit esp6_fini(void)
661{
662 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
663 pr_info("%s: can't remove protocol\n", __func__);
664 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
665 pr_info("%s: can't remove xfrm type\n", __func__);
666}
667
668module_init(esp6_init);
669module_exit(esp6_fini);
670
671MODULE_LICENSE("GPL");
672MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C)2002 USAGI/WIDE Project
4 *
5 * Authors
6 *
7 * Mitsuru KANDA @USAGI : IPv6 Support
8 * Kazunori MIYAZAWA @USAGI :
9 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
10 *
11 * This file is derived from net/ipv4/esp.c
12 */
13
14#define pr_fmt(fmt) "IPv6: " fmt
15
16#include <crypto/aead.h>
17#include <crypto/authenc.h>
18#include <linux/err.h>
19#include <linux/module.h>
20#include <net/ip.h>
21#include <net/xfrm.h>
22#include <net/esp.h>
23#include <linux/scatterlist.h>
24#include <linux/kernel.h>
25#include <linux/pfkeyv2.h>
26#include <linux/random.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29#include <net/ip6_checksum.h>
30#include <net/ip6_route.h>
31#include <net/icmp.h>
32#include <net/ipv6.h>
33#include <net/protocol.h>
34#include <net/udp.h>
35#include <linux/icmpv6.h>
36#include <net/tcp.h>
37#include <net/espintcp.h>
38#include <net/inet6_hashtables.h>
39
40#include <linux/highmem.h>
41
42struct esp_skb_cb {
43 struct xfrm_skb_cb xfrm;
44 void *tmp;
45};
46
47struct esp_output_extra {
48 __be32 seqhi;
49 u32 esphoff;
50};
51
52#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
53
54/*
55 * Allocate an AEAD request structure with extra space for SG and IV.
56 *
57 * For alignment considerations the upper 32 bits of the sequence number are
58 * placed at the front, if present. Followed by the IV, the request and finally
59 * the SG list.
60 *
61 * TODO: Use spare space in skb for this where possible.
62 */
63static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
64{
65 unsigned int len;
66
67 len = seqihlen;
68
69 len += crypto_aead_ivsize(aead);
70
71 if (len) {
72 len += crypto_aead_alignmask(aead) &
73 ~(crypto_tfm_ctx_alignment() - 1);
74 len = ALIGN(len, crypto_tfm_ctx_alignment());
75 }
76
77 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
78 len = ALIGN(len, __alignof__(struct scatterlist));
79
80 len += sizeof(struct scatterlist) * nfrags;
81
82 return kmalloc(len, GFP_ATOMIC);
83}
84
85static inline void *esp_tmp_extra(void *tmp)
86{
87 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
88}
89
90static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
91{
92 return crypto_aead_ivsize(aead) ?
93 PTR_ALIGN((u8 *)tmp + seqhilen,
94 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
95}
96
97static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
98{
99 struct aead_request *req;
100
101 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
102 crypto_tfm_ctx_alignment());
103 aead_request_set_tfm(req, aead);
104 return req;
105}
106
107static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
108 struct aead_request *req)
109{
110 return (void *)ALIGN((unsigned long)(req + 1) +
111 crypto_aead_reqsize(aead),
112 __alignof__(struct scatterlist));
113}
114
115static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
116{
117 struct esp_output_extra *extra = esp_tmp_extra(tmp);
118 struct crypto_aead *aead = x->data;
119 int extralen = 0;
120 u8 *iv;
121 struct aead_request *req;
122 struct scatterlist *sg;
123
124 if (x->props.flags & XFRM_STATE_ESN)
125 extralen += sizeof(*extra);
126
127 iv = esp_tmp_iv(aead, tmp, extralen);
128 req = esp_tmp_req(aead, iv);
129
130 /* Unref skb_frag_pages in the src scatterlist if necessary.
131 * Skip the first sg which comes from skb->data.
132 */
133 if (req->src != req->dst)
134 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
135 put_page(sg_page(sg));
136}
137
138#ifdef CONFIG_INET6_ESPINTCP
139struct esp_tcp_sk {
140 struct sock *sk;
141 struct rcu_head rcu;
142};
143
144static void esp_free_tcp_sk(struct rcu_head *head)
145{
146 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
147
148 sock_put(esk->sk);
149 kfree(esk);
150}
151
152static struct sock *esp6_find_tcp_sk(struct xfrm_state *x)
153{
154 struct xfrm_encap_tmpl *encap = x->encap;
155 struct esp_tcp_sk *esk;
156 __be16 sport, dport;
157 struct sock *nsk;
158 struct sock *sk;
159
160 sk = rcu_dereference(x->encap_sk);
161 if (sk && sk->sk_state == TCP_ESTABLISHED)
162 return sk;
163
164 spin_lock_bh(&x->lock);
165 sport = encap->encap_sport;
166 dport = encap->encap_dport;
167 nsk = rcu_dereference_protected(x->encap_sk,
168 lockdep_is_held(&x->lock));
169 if (sk && sk == nsk) {
170 esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
171 if (!esk) {
172 spin_unlock_bh(&x->lock);
173 return ERR_PTR(-ENOMEM);
174 }
175 RCU_INIT_POINTER(x->encap_sk, NULL);
176 esk->sk = sk;
177 call_rcu(&esk->rcu, esp_free_tcp_sk);
178 }
179 spin_unlock_bh(&x->lock);
180
181 sk = __inet6_lookup_established(xs_net(x), &tcp_hashinfo, &x->id.daddr.in6,
182 dport, &x->props.saddr.in6, ntohs(sport), 0, 0);
183 if (!sk)
184 return ERR_PTR(-ENOENT);
185
186 if (!tcp_is_ulp_esp(sk)) {
187 sock_put(sk);
188 return ERR_PTR(-EINVAL);
189 }
190
191 spin_lock_bh(&x->lock);
192 nsk = rcu_dereference_protected(x->encap_sk,
193 lockdep_is_held(&x->lock));
194 if (encap->encap_sport != sport ||
195 encap->encap_dport != dport) {
196 sock_put(sk);
197 sk = nsk ?: ERR_PTR(-EREMCHG);
198 } else if (sk == nsk) {
199 sock_put(sk);
200 } else {
201 rcu_assign_pointer(x->encap_sk, sk);
202 }
203 spin_unlock_bh(&x->lock);
204
205 return sk;
206}
207
208static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
209{
210 struct sock *sk;
211 int err;
212
213 rcu_read_lock();
214
215 sk = esp6_find_tcp_sk(x);
216 err = PTR_ERR_OR_ZERO(sk);
217 if (err)
218 goto out;
219
220 bh_lock_sock(sk);
221 if (sock_owned_by_user(sk))
222 err = espintcp_queue_out(sk, skb);
223 else
224 err = espintcp_push_skb(sk, skb);
225 bh_unlock_sock(sk);
226
227out:
228 rcu_read_unlock();
229 return err;
230}
231
232static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
233 struct sk_buff *skb)
234{
235 struct dst_entry *dst = skb_dst(skb);
236 struct xfrm_state *x = dst->xfrm;
237
238 return esp_output_tcp_finish(x, skb);
239}
240
241static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
242{
243 int err;
244
245 local_bh_disable();
246 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
247 local_bh_enable();
248
249 /* EINPROGRESS just happens to do the right thing. It
250 * actually means that the skb has been consumed and
251 * isn't coming back.
252 */
253 return err ?: -EINPROGRESS;
254}
255#else
256static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
257{
258 kfree_skb(skb);
259
260 return -EOPNOTSUPP;
261}
262#endif
263
264static void esp_output_encap_csum(struct sk_buff *skb)
265{
266 /* UDP encap with IPv6 requires a valid checksum */
267 if (*skb_mac_header(skb) == IPPROTO_UDP) {
268 struct udphdr *uh = udp_hdr(skb);
269 struct ipv6hdr *ip6h = ipv6_hdr(skb);
270 int len = ntohs(uh->len);
271 unsigned int offset = skb_transport_offset(skb);
272 __wsum csum = skb_checksum(skb, offset, skb->len - offset, 0);
273
274 uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
275 len, IPPROTO_UDP, csum);
276 if (uh->check == 0)
277 uh->check = CSUM_MANGLED_0;
278 }
279}
280
281static void esp_output_done(struct crypto_async_request *base, int err)
282{
283 struct sk_buff *skb = base->data;
284 struct xfrm_offload *xo = xfrm_offload(skb);
285 void *tmp;
286 struct xfrm_state *x;
287
288 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
289 struct sec_path *sp = skb_sec_path(skb);
290
291 x = sp->xvec[sp->len - 1];
292 } else {
293 x = skb_dst(skb)->xfrm;
294 }
295
296 tmp = ESP_SKB_CB(skb)->tmp;
297 esp_ssg_unref(x, tmp);
298 kfree(tmp);
299
300 esp_output_encap_csum(skb);
301
302 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
303 if (err) {
304 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
305 kfree_skb(skb);
306 return;
307 }
308
309 skb_push(skb, skb->data - skb_mac_header(skb));
310 secpath_reset(skb);
311 xfrm_dev_resume(skb);
312 } else {
313 if (!err &&
314 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
315 esp_output_tail_tcp(x, skb);
316 else
317 xfrm_output_resume(skb, err);
318 }
319}
320
321/* Move ESP header back into place. */
322static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
323{
324 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
325 void *tmp = ESP_SKB_CB(skb)->tmp;
326 __be32 *seqhi = esp_tmp_extra(tmp);
327
328 esph->seq_no = esph->spi;
329 esph->spi = *seqhi;
330}
331
332static void esp_output_restore_header(struct sk_buff *skb)
333{
334 void *tmp = ESP_SKB_CB(skb)->tmp;
335 struct esp_output_extra *extra = esp_tmp_extra(tmp);
336
337 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
338 sizeof(__be32));
339}
340
341static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
342 struct xfrm_state *x,
343 struct ip_esp_hdr *esph,
344 struct esp_output_extra *extra)
345{
346 /* For ESN we move the header forward by 4 bytes to
347 * accomodate the high bits. We will move it back after
348 * encryption.
349 */
350 if ((x->props.flags & XFRM_STATE_ESN)) {
351 __u32 seqhi;
352 struct xfrm_offload *xo = xfrm_offload(skb);
353
354 if (xo)
355 seqhi = xo->seq.hi;
356 else
357 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
358
359 extra->esphoff = (unsigned char *)esph -
360 skb_transport_header(skb);
361 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
362 extra->seqhi = esph->spi;
363 esph->seq_no = htonl(seqhi);
364 }
365
366 esph->spi = x->id.spi;
367
368 return esph;
369}
370
371static void esp_output_done_esn(struct crypto_async_request *base, int err)
372{
373 struct sk_buff *skb = base->data;
374
375 esp_output_restore_header(skb);
376 esp_output_done(base, err);
377}
378
379static struct ip_esp_hdr *esp6_output_udp_encap(struct sk_buff *skb,
380 int encap_type,
381 struct esp_info *esp,
382 __be16 sport,
383 __be16 dport)
384{
385 struct udphdr *uh;
386 __be32 *udpdata32;
387 unsigned int len;
388
389 len = skb->len + esp->tailen - skb_transport_offset(skb);
390 if (len > U16_MAX)
391 return ERR_PTR(-EMSGSIZE);
392
393 uh = (struct udphdr *)esp->esph;
394 uh->source = sport;
395 uh->dest = dport;
396 uh->len = htons(len);
397 uh->check = 0;
398
399 *skb_mac_header(skb) = IPPROTO_UDP;
400
401 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
402 udpdata32 = (__be32 *)(uh + 1);
403 udpdata32[0] = udpdata32[1] = 0;
404 return (struct ip_esp_hdr *)(udpdata32 + 2);
405 }
406
407 return (struct ip_esp_hdr *)(uh + 1);
408}
409
410#ifdef CONFIG_INET6_ESPINTCP
411static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x,
412 struct sk_buff *skb,
413 struct esp_info *esp)
414{
415 __be16 *lenp = (void *)esp->esph;
416 struct ip_esp_hdr *esph;
417 unsigned int len;
418 struct sock *sk;
419
420 len = skb->len + esp->tailen - skb_transport_offset(skb);
421 if (len > IP_MAX_MTU)
422 return ERR_PTR(-EMSGSIZE);
423
424 rcu_read_lock();
425 sk = esp6_find_tcp_sk(x);
426 rcu_read_unlock();
427
428 if (IS_ERR(sk))
429 return ERR_CAST(sk);
430
431 *lenp = htons(len);
432 esph = (struct ip_esp_hdr *)(lenp + 1);
433
434 return esph;
435}
436#else
437static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x,
438 struct sk_buff *skb,
439 struct esp_info *esp)
440{
441 return ERR_PTR(-EOPNOTSUPP);
442}
443#endif
444
445static int esp6_output_encap(struct xfrm_state *x, struct sk_buff *skb,
446 struct esp_info *esp)
447{
448 struct xfrm_encap_tmpl *encap = x->encap;
449 struct ip_esp_hdr *esph;
450 __be16 sport, dport;
451 int encap_type;
452
453 spin_lock_bh(&x->lock);
454 sport = encap->encap_sport;
455 dport = encap->encap_dport;
456 encap_type = encap->encap_type;
457 spin_unlock_bh(&x->lock);
458
459 switch (encap_type) {
460 default:
461 case UDP_ENCAP_ESPINUDP:
462 case UDP_ENCAP_ESPINUDP_NON_IKE:
463 esph = esp6_output_udp_encap(skb, encap_type, esp, sport, dport);
464 break;
465 case TCP_ENCAP_ESPINTCP:
466 esph = esp6_output_tcp_encap(x, skb, esp);
467 break;
468 }
469
470 if (IS_ERR(esph))
471 return PTR_ERR(esph);
472
473 esp->esph = esph;
474
475 return 0;
476}
477
478int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
479{
480 u8 *tail;
481 u8 *vaddr;
482 int nfrags;
483 int esph_offset;
484 struct page *page;
485 struct sk_buff *trailer;
486 int tailen = esp->tailen;
487
488 if (x->encap) {
489 int err = esp6_output_encap(x, skb, esp);
490
491 if (err < 0)
492 return err;
493 }
494
495 if (!skb_cloned(skb)) {
496 if (tailen <= skb_tailroom(skb)) {
497 nfrags = 1;
498 trailer = skb;
499 tail = skb_tail_pointer(trailer);
500
501 goto skip_cow;
502 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
503 && !skb_has_frag_list(skb)) {
504 int allocsize;
505 struct sock *sk = skb->sk;
506 struct page_frag *pfrag = &x->xfrag;
507
508 esp->inplace = false;
509
510 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
511
512 spin_lock_bh(&x->lock);
513
514 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
515 spin_unlock_bh(&x->lock);
516 goto cow;
517 }
518
519 page = pfrag->page;
520 get_page(page);
521
522 vaddr = kmap_atomic(page);
523
524 tail = vaddr + pfrag->offset;
525
526 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
527
528 kunmap_atomic(vaddr);
529
530 nfrags = skb_shinfo(skb)->nr_frags;
531
532 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
533 tailen);
534 skb_shinfo(skb)->nr_frags = ++nfrags;
535
536 pfrag->offset = pfrag->offset + allocsize;
537
538 spin_unlock_bh(&x->lock);
539
540 nfrags++;
541
542 skb->len += tailen;
543 skb->data_len += tailen;
544 skb->truesize += tailen;
545 if (sk && sk_fullsock(sk))
546 refcount_add(tailen, &sk->sk_wmem_alloc);
547
548 goto out;
549 }
550 }
551
552cow:
553 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
554
555 nfrags = skb_cow_data(skb, tailen, &trailer);
556 if (nfrags < 0)
557 goto out;
558 tail = skb_tail_pointer(trailer);
559 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
560
561skip_cow:
562 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
563 pskb_put(skb, trailer, tailen);
564
565out:
566 return nfrags;
567}
568EXPORT_SYMBOL_GPL(esp6_output_head);
569
570int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
571{
572 u8 *iv;
573 int alen;
574 void *tmp;
575 int ivlen;
576 int assoclen;
577 int extralen;
578 struct page *page;
579 struct ip_esp_hdr *esph;
580 struct aead_request *req;
581 struct crypto_aead *aead;
582 struct scatterlist *sg, *dsg;
583 struct esp_output_extra *extra;
584 int err = -ENOMEM;
585
586 assoclen = sizeof(struct ip_esp_hdr);
587 extralen = 0;
588
589 if (x->props.flags & XFRM_STATE_ESN) {
590 extralen += sizeof(*extra);
591 assoclen += sizeof(__be32);
592 }
593
594 aead = x->data;
595 alen = crypto_aead_authsize(aead);
596 ivlen = crypto_aead_ivsize(aead);
597
598 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
599 if (!tmp)
600 goto error;
601
602 extra = esp_tmp_extra(tmp);
603 iv = esp_tmp_iv(aead, tmp, extralen);
604 req = esp_tmp_req(aead, iv);
605 sg = esp_req_sg(aead, req);
606
607 if (esp->inplace)
608 dsg = sg;
609 else
610 dsg = &sg[esp->nfrags];
611
612 esph = esp_output_set_esn(skb, x, esp->esph, extra);
613 esp->esph = esph;
614
615 sg_init_table(sg, esp->nfrags);
616 err = skb_to_sgvec(skb, sg,
617 (unsigned char *)esph - skb->data,
618 assoclen + ivlen + esp->clen + alen);
619 if (unlikely(err < 0))
620 goto error_free;
621
622 if (!esp->inplace) {
623 int allocsize;
624 struct page_frag *pfrag = &x->xfrag;
625
626 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
627
628 spin_lock_bh(&x->lock);
629 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
630 spin_unlock_bh(&x->lock);
631 goto error_free;
632 }
633
634 skb_shinfo(skb)->nr_frags = 1;
635
636 page = pfrag->page;
637 get_page(page);
638 /* replace page frags in skb with new page */
639 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
640 pfrag->offset = pfrag->offset + allocsize;
641 spin_unlock_bh(&x->lock);
642
643 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
644 err = skb_to_sgvec(skb, dsg,
645 (unsigned char *)esph - skb->data,
646 assoclen + ivlen + esp->clen + alen);
647 if (unlikely(err < 0))
648 goto error_free;
649 }
650
651 if ((x->props.flags & XFRM_STATE_ESN))
652 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
653 else
654 aead_request_set_callback(req, 0, esp_output_done, skb);
655
656 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
657 aead_request_set_ad(req, assoclen);
658
659 memset(iv, 0, ivlen);
660 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
661 min(ivlen, 8));
662
663 ESP_SKB_CB(skb)->tmp = tmp;
664 err = crypto_aead_encrypt(req);
665
666 switch (err) {
667 case -EINPROGRESS:
668 goto error;
669
670 case -ENOSPC:
671 err = NET_XMIT_DROP;
672 break;
673
674 case 0:
675 if ((x->props.flags & XFRM_STATE_ESN))
676 esp_output_restore_header(skb);
677 esp_output_encap_csum(skb);
678 }
679
680 if (sg != dsg)
681 esp_ssg_unref(x, tmp);
682
683 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
684 err = esp_output_tail_tcp(x, skb);
685
686error_free:
687 kfree(tmp);
688error:
689 return err;
690}
691EXPORT_SYMBOL_GPL(esp6_output_tail);
692
693static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
694{
695 int alen;
696 int blksize;
697 struct ip_esp_hdr *esph;
698 struct crypto_aead *aead;
699 struct esp_info esp;
700
701 esp.inplace = true;
702
703 esp.proto = *skb_mac_header(skb);
704 *skb_mac_header(skb) = IPPROTO_ESP;
705
706 /* skb is pure payload to encrypt */
707
708 aead = x->data;
709 alen = crypto_aead_authsize(aead);
710
711 esp.tfclen = 0;
712 if (x->tfcpad) {
713 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
714 u32 padto;
715
716 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
717 if (skb->len < padto)
718 esp.tfclen = padto - skb->len;
719 }
720 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
721 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
722 esp.plen = esp.clen - skb->len - esp.tfclen;
723 esp.tailen = esp.tfclen + esp.plen + alen;
724
725 esp.esph = ip_esp_hdr(skb);
726
727 esp.nfrags = esp6_output_head(x, skb, &esp);
728 if (esp.nfrags < 0)
729 return esp.nfrags;
730
731 esph = esp.esph;
732 esph->spi = x->id.spi;
733
734 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
735 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
736 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
737
738 skb_push(skb, -skb_network_offset(skb));
739
740 return esp6_output_tail(x, skb, &esp);
741}
742
743static inline int esp_remove_trailer(struct sk_buff *skb)
744{
745 struct xfrm_state *x = xfrm_input_state(skb);
746 struct xfrm_offload *xo = xfrm_offload(skb);
747 struct crypto_aead *aead = x->data;
748 int alen, hlen, elen;
749 int padlen, trimlen;
750 __wsum csumdiff;
751 u8 nexthdr[2];
752 int ret;
753
754 alen = crypto_aead_authsize(aead);
755 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
756 elen = skb->len - hlen;
757
758 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
759 ret = xo->proto;
760 goto out;
761 }
762
763 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
764 BUG_ON(ret);
765
766 ret = -EINVAL;
767 padlen = nexthdr[0];
768 if (padlen + 2 + alen >= elen) {
769 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
770 padlen + 2, elen - alen);
771 goto out;
772 }
773
774 trimlen = alen + padlen + 2;
775 if (skb->ip_summed == CHECKSUM_COMPLETE) {
776 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
777 skb->csum = csum_block_sub(skb->csum, csumdiff,
778 skb->len - trimlen);
779 }
780 pskb_trim(skb, skb->len - trimlen);
781
782 ret = nexthdr[1];
783
784out:
785 return ret;
786}
787
788int esp6_input_done2(struct sk_buff *skb, int err)
789{
790 struct xfrm_state *x = xfrm_input_state(skb);
791 struct xfrm_offload *xo = xfrm_offload(skb);
792 struct crypto_aead *aead = x->data;
793 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
794 int hdr_len = skb_network_header_len(skb);
795
796 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
797 kfree(ESP_SKB_CB(skb)->tmp);
798
799 if (unlikely(err))
800 goto out;
801
802 err = esp_remove_trailer(skb);
803 if (unlikely(err < 0))
804 goto out;
805
806 if (x->encap) {
807 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
808 int offset = skb_network_offset(skb) + sizeof(*ip6h);
809 struct xfrm_encap_tmpl *encap = x->encap;
810 u8 nexthdr = ip6h->nexthdr;
811 __be16 frag_off, source;
812 struct udphdr *uh;
813 struct tcphdr *th;
814
815 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
816 uh = (void *)(skb->data + offset);
817 th = (void *)(skb->data + offset);
818 hdr_len += offset;
819
820 switch (x->encap->encap_type) {
821 case TCP_ENCAP_ESPINTCP:
822 source = th->source;
823 break;
824 case UDP_ENCAP_ESPINUDP:
825 case UDP_ENCAP_ESPINUDP_NON_IKE:
826 source = uh->source;
827 break;
828 default:
829 WARN_ON_ONCE(1);
830 err = -EINVAL;
831 goto out;
832 }
833
834 /*
835 * 1) if the NAT-T peer's IP or port changed then
836 * advertize the change to the keying daemon.
837 * This is an inbound SA, so just compare
838 * SRC ports.
839 */
840 if (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) ||
841 source != encap->encap_sport) {
842 xfrm_address_t ipaddr;
843
844 memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6));
845 km_new_mapping(x, &ipaddr, source);
846
847 /* XXX: perhaps add an extra
848 * policy check here, to see
849 * if we should allow or
850 * reject a packet from a
851 * different source
852 * address/port.
853 */
854 }
855
856 /*
857 * 2) ignore UDP/TCP checksums in case
858 * of NAT-T in Transport Mode, or
859 * perform other post-processing fixes
860 * as per draft-ietf-ipsec-udp-encaps-06,
861 * section 3.1.2
862 */
863 if (x->props.mode == XFRM_MODE_TRANSPORT)
864 skb->ip_summed = CHECKSUM_UNNECESSARY;
865 }
866
867 skb_postpull_rcsum(skb, skb_network_header(skb),
868 skb_network_header_len(skb));
869 skb_pull_rcsum(skb, hlen);
870 if (x->props.mode == XFRM_MODE_TUNNEL)
871 skb_reset_transport_header(skb);
872 else
873 skb_set_transport_header(skb, -hdr_len);
874
875 /* RFC4303: Drop dummy packets without any error */
876 if (err == IPPROTO_NONE)
877 err = -EINVAL;
878
879out:
880 return err;
881}
882EXPORT_SYMBOL_GPL(esp6_input_done2);
883
884static void esp_input_done(struct crypto_async_request *base, int err)
885{
886 struct sk_buff *skb = base->data;
887
888 xfrm_input_resume(skb, esp6_input_done2(skb, err));
889}
890
891static void esp_input_restore_header(struct sk_buff *skb)
892{
893 esp_restore_header(skb, 0);
894 __skb_pull(skb, 4);
895}
896
897static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
898{
899 struct xfrm_state *x = xfrm_input_state(skb);
900
901 /* For ESN we move the header forward by 4 bytes to
902 * accomodate the high bits. We will move it back after
903 * decryption.
904 */
905 if ((x->props.flags & XFRM_STATE_ESN)) {
906 struct ip_esp_hdr *esph = skb_push(skb, 4);
907
908 *seqhi = esph->spi;
909 esph->spi = esph->seq_no;
910 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
911 }
912}
913
914static void esp_input_done_esn(struct crypto_async_request *base, int err)
915{
916 struct sk_buff *skb = base->data;
917
918 esp_input_restore_header(skb);
919 esp_input_done(base, err);
920}
921
922static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
923{
924 struct crypto_aead *aead = x->data;
925 struct aead_request *req;
926 struct sk_buff *trailer;
927 int ivlen = crypto_aead_ivsize(aead);
928 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
929 int nfrags;
930 int assoclen;
931 int seqhilen;
932 int ret = 0;
933 void *tmp;
934 __be32 *seqhi;
935 u8 *iv;
936 struct scatterlist *sg;
937
938 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
939 ret = -EINVAL;
940 goto out;
941 }
942
943 if (elen <= 0) {
944 ret = -EINVAL;
945 goto out;
946 }
947
948 assoclen = sizeof(struct ip_esp_hdr);
949 seqhilen = 0;
950
951 if (x->props.flags & XFRM_STATE_ESN) {
952 seqhilen += sizeof(__be32);
953 assoclen += seqhilen;
954 }
955
956 if (!skb_cloned(skb)) {
957 if (!skb_is_nonlinear(skb)) {
958 nfrags = 1;
959
960 goto skip_cow;
961 } else if (!skb_has_frag_list(skb)) {
962 nfrags = skb_shinfo(skb)->nr_frags;
963 nfrags++;
964
965 goto skip_cow;
966 }
967 }
968
969 nfrags = skb_cow_data(skb, 0, &trailer);
970 if (nfrags < 0) {
971 ret = -EINVAL;
972 goto out;
973 }
974
975skip_cow:
976 ret = -ENOMEM;
977 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
978 if (!tmp)
979 goto out;
980
981 ESP_SKB_CB(skb)->tmp = tmp;
982 seqhi = esp_tmp_extra(tmp);
983 iv = esp_tmp_iv(aead, tmp, seqhilen);
984 req = esp_tmp_req(aead, iv);
985 sg = esp_req_sg(aead, req);
986
987 esp_input_set_header(skb, seqhi);
988
989 sg_init_table(sg, nfrags);
990 ret = skb_to_sgvec(skb, sg, 0, skb->len);
991 if (unlikely(ret < 0)) {
992 kfree(tmp);
993 goto out;
994 }
995
996 skb->ip_summed = CHECKSUM_NONE;
997
998 if ((x->props.flags & XFRM_STATE_ESN))
999 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
1000 else
1001 aead_request_set_callback(req, 0, esp_input_done, skb);
1002
1003 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
1004 aead_request_set_ad(req, assoclen);
1005
1006 ret = crypto_aead_decrypt(req);
1007 if (ret == -EINPROGRESS)
1008 goto out;
1009
1010 if ((x->props.flags & XFRM_STATE_ESN))
1011 esp_input_restore_header(skb);
1012
1013 ret = esp6_input_done2(skb, ret);
1014
1015out:
1016 return ret;
1017}
1018
1019static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
1020 u8 type, u8 code, int offset, __be32 info)
1021{
1022 struct net *net = dev_net(skb->dev);
1023 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
1024 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
1025 struct xfrm_state *x;
1026
1027 if (type != ICMPV6_PKT_TOOBIG &&
1028 type != NDISC_REDIRECT)
1029 return 0;
1030
1031 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
1032 esph->spi, IPPROTO_ESP, AF_INET6);
1033 if (!x)
1034 return 0;
1035
1036 if (type == NDISC_REDIRECT)
1037 ip6_redirect(skb, net, skb->dev->ifindex, 0,
1038 sock_net_uid(net, NULL));
1039 else
1040 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
1041 xfrm_state_put(x);
1042
1043 return 0;
1044}
1045
1046static void esp6_destroy(struct xfrm_state *x)
1047{
1048 struct crypto_aead *aead = x->data;
1049
1050 if (!aead)
1051 return;
1052
1053 crypto_free_aead(aead);
1054}
1055
1056static int esp_init_aead(struct xfrm_state *x)
1057{
1058 char aead_name[CRYPTO_MAX_ALG_NAME];
1059 struct crypto_aead *aead;
1060 int err;
1061
1062 err = -ENAMETOOLONG;
1063 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1064 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
1065 goto error;
1066
1067 aead = crypto_alloc_aead(aead_name, 0, 0);
1068 err = PTR_ERR(aead);
1069 if (IS_ERR(aead))
1070 goto error;
1071
1072 x->data = aead;
1073
1074 err = crypto_aead_setkey(aead, x->aead->alg_key,
1075 (x->aead->alg_key_len + 7) / 8);
1076 if (err)
1077 goto error;
1078
1079 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
1080 if (err)
1081 goto error;
1082
1083error:
1084 return err;
1085}
1086
1087static int esp_init_authenc(struct xfrm_state *x)
1088{
1089 struct crypto_aead *aead;
1090 struct crypto_authenc_key_param *param;
1091 struct rtattr *rta;
1092 char *key;
1093 char *p;
1094 char authenc_name[CRYPTO_MAX_ALG_NAME];
1095 unsigned int keylen;
1096 int err;
1097
1098 err = -EINVAL;
1099 if (!x->ealg)
1100 goto error;
1101
1102 err = -ENAMETOOLONG;
1103
1104 if ((x->props.flags & XFRM_STATE_ESN)) {
1105 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1106 "%s%sauthencesn(%s,%s)%s",
1107 x->geniv ?: "", x->geniv ? "(" : "",
1108 x->aalg ? x->aalg->alg_name : "digest_null",
1109 x->ealg->alg_name,
1110 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1111 goto error;
1112 } else {
1113 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1114 "%s%sauthenc(%s,%s)%s",
1115 x->geniv ?: "", x->geniv ? "(" : "",
1116 x->aalg ? x->aalg->alg_name : "digest_null",
1117 x->ealg->alg_name,
1118 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1119 goto error;
1120 }
1121
1122 aead = crypto_alloc_aead(authenc_name, 0, 0);
1123 err = PTR_ERR(aead);
1124 if (IS_ERR(aead))
1125 goto error;
1126
1127 x->data = aead;
1128
1129 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
1130 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
1131 err = -ENOMEM;
1132 key = kmalloc(keylen, GFP_KERNEL);
1133 if (!key)
1134 goto error;
1135
1136 p = key;
1137 rta = (void *)p;
1138 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1139 rta->rta_len = RTA_LENGTH(sizeof(*param));
1140 param = RTA_DATA(rta);
1141 p += RTA_SPACE(sizeof(*param));
1142
1143 if (x->aalg) {
1144 struct xfrm_algo_desc *aalg_desc;
1145
1146 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1147 p += (x->aalg->alg_key_len + 7) / 8;
1148
1149 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1150 BUG_ON(!aalg_desc);
1151
1152 err = -EINVAL;
1153 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1154 crypto_aead_authsize(aead)) {
1155 pr_info("ESP: %s digestsize %u != %hu\n",
1156 x->aalg->alg_name,
1157 crypto_aead_authsize(aead),
1158 aalg_desc->uinfo.auth.icv_fullbits / 8);
1159 goto free_key;
1160 }
1161
1162 err = crypto_aead_setauthsize(
1163 aead, x->aalg->alg_trunc_len / 8);
1164 if (err)
1165 goto free_key;
1166 }
1167
1168 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1169 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1170
1171 err = crypto_aead_setkey(aead, key, keylen);
1172
1173free_key:
1174 kfree(key);
1175
1176error:
1177 return err;
1178}
1179
1180static int esp6_init_state(struct xfrm_state *x)
1181{
1182 struct crypto_aead *aead;
1183 u32 align;
1184 int err;
1185
1186 x->data = NULL;
1187
1188 if (x->aead)
1189 err = esp_init_aead(x);
1190 else
1191 err = esp_init_authenc(x);
1192
1193 if (err)
1194 goto error;
1195
1196 aead = x->data;
1197
1198 x->props.header_len = sizeof(struct ip_esp_hdr) +
1199 crypto_aead_ivsize(aead);
1200 switch (x->props.mode) {
1201 case XFRM_MODE_BEET:
1202 if (x->sel.family != AF_INET6)
1203 x->props.header_len += IPV4_BEET_PHMAXLEN +
1204 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
1205 break;
1206 default:
1207 case XFRM_MODE_TRANSPORT:
1208 break;
1209 case XFRM_MODE_TUNNEL:
1210 x->props.header_len += sizeof(struct ipv6hdr);
1211 break;
1212 }
1213
1214 if (x->encap) {
1215 struct xfrm_encap_tmpl *encap = x->encap;
1216
1217 switch (encap->encap_type) {
1218 default:
1219 err = -EINVAL;
1220 goto error;
1221 case UDP_ENCAP_ESPINUDP:
1222 x->props.header_len += sizeof(struct udphdr);
1223 break;
1224 case UDP_ENCAP_ESPINUDP_NON_IKE:
1225 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1226 break;
1227#ifdef CONFIG_INET6_ESPINTCP
1228 case TCP_ENCAP_ESPINTCP:
1229 /* only the length field, TCP encap is done by
1230 * the socket
1231 */
1232 x->props.header_len += 2;
1233 break;
1234#endif
1235 }
1236 }
1237
1238 align = ALIGN(crypto_aead_blocksize(aead), 4);
1239 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1240
1241error:
1242 return err;
1243}
1244
1245static int esp6_rcv_cb(struct sk_buff *skb, int err)
1246{
1247 return 0;
1248}
1249
1250static const struct xfrm_type esp6_type = {
1251 .description = "ESP6",
1252 .owner = THIS_MODULE,
1253 .proto = IPPROTO_ESP,
1254 .flags = XFRM_TYPE_REPLAY_PROT,
1255 .init_state = esp6_init_state,
1256 .destructor = esp6_destroy,
1257 .input = esp6_input,
1258 .output = esp6_output,
1259 .hdr_offset = xfrm6_find_1stfragopt,
1260};
1261
1262static struct xfrm6_protocol esp6_protocol = {
1263 .handler = xfrm6_rcv,
1264 .input_handler = xfrm_input,
1265 .cb_handler = esp6_rcv_cb,
1266 .err_handler = esp6_err,
1267 .priority = 0,
1268};
1269
1270static int __init esp6_init(void)
1271{
1272 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
1273 pr_info("%s: can't add xfrm type\n", __func__);
1274 return -EAGAIN;
1275 }
1276 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
1277 pr_info("%s: can't add protocol\n", __func__);
1278 xfrm_unregister_type(&esp6_type, AF_INET6);
1279 return -EAGAIN;
1280 }
1281
1282 return 0;
1283}
1284
1285static void __exit esp6_fini(void)
1286{
1287 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
1288 pr_info("%s: can't remove protocol\n", __func__);
1289 xfrm_unregister_type(&esp6_type, AF_INET6);
1290}
1291
1292module_init(esp6_init);
1293module_exit(esp6_fini);
1294
1295MODULE_LICENSE("GPL");
1296MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);