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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_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_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
117static 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
125/* 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
149static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
150{
151 int err;
152 struct ip_esp_hdr *esph;
153 struct crypto_aead *aead;
154 struct aead_request *req;
155 struct scatterlist *sg;
156 struct sk_buff *trailer;
157 void *tmp;
158 int blksize;
159 int clen;
160 int alen;
161 int plen;
162 int ivlen;
163 int tfclen;
164 int nfrags;
165 int assoclen;
166 int seqhilen;
167 u8 *iv;
168 u8 *tail;
169 __be32 *seqhi;
170 __be64 seqno;
171
172 /* skb is pure payload to encrypt */
173 aead = x->data;
174 alen = crypto_aead_authsize(aead);
175 ivlen = crypto_aead_ivsize(aead);
176
177 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 }
186 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
187 clen = ALIGN(skb->len + 2 + tfclen, blksize);
188 plen = clen - skb->len - tfclen;
189
190 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
191 if (err < 0)
192 goto error;
193 nfrags = err;
194
195 assoclen = sizeof(*esph);
196 seqhilen = 0;
197
198 if (x->props.flags & XFRM_STATE_ESN) {
199 seqhilen += sizeof(__be32);
200 assoclen += seqhilen;
201 }
202
203 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
204 if (!tmp) {
205 err = -ENOMEM;
206 goto error;
207 }
208
209 seqhi = esp_tmp_seqhi(tmp);
210 iv = esp_tmp_iv(aead, tmp, seqhilen);
211 req = esp_tmp_req(aead, iv);
212 sg = esp_req_sg(aead, req);
213
214 /* Fill padding... */
215 tail = skb_tail_pointer(trailer);
216 if (tfclen) {
217 memset(tail, 0, tfclen);
218 tail += tfclen;
219 }
220 do {
221 int i;
222 for (i = 0; i < plen - 2; i++)
223 tail[i] = i + 1;
224 } while (0);
225 tail[plen - 2] = plen - 2;
226 tail[plen - 1] = *skb_mac_header(skb);
227 pskb_put(skb, trailer, clen - skb->len + alen);
228
229 skb_push(skb, -skb_network_offset(skb));
230 esph = ip_esp_hdr(skb);
231 *skb_mac_header(skb) = IPPROTO_ESP;
232
233 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
234
235 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
250 sg_init_table(sg, nfrags);
251 skb_to_sgvec(skb, sg,
252 (unsigned char *)esph - skb->data,
253 assoclen + ivlen + clen + alen);
254
255 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
256 aead_request_set_ad(req, assoclen);
257
258 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
259 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
260
261 memset(iv, 0, ivlen);
262 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
263 min(ivlen, 8));
264
265 ESP_SKB_CB(skb)->tmp = tmp;
266 err = crypto_aead_encrypt(req);
267
268 switch (err) {
269 case -EINPROGRESS:
270 goto error;
271
272 case -EBUSY:
273 err = NET_XMIT_DROP;
274 break;
275
276 case 0:
277 if ((x->props.flags & XFRM_STATE_ESN))
278 esp_output_restore_header(skb);
279 }
280
281 kfree(tmp);
282
283error:
284 return err;
285}
286
287static int esp_input_done2(struct sk_buff *skb, int err)
288{
289 struct xfrm_state *x = xfrm_input_state(skb);
290 struct crypto_aead *aead = x->data;
291 int alen = crypto_aead_authsize(aead);
292 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
293 int elen = skb->len - hlen;
294 int hdr_len = skb_network_header_len(skb);
295 int padlen;
296 u8 nexthdr[2];
297
298 kfree(ESP_SKB_CB(skb)->tmp);
299
300 if (unlikely(err))
301 goto out;
302
303 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
304 BUG();
305
306 err = -EINVAL;
307 padlen = nexthdr[0];
308 if (padlen + 2 + alen >= elen) {
309 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
310 padlen + 2, elen - alen);
311 goto out;
312 }
313
314 /* ... check padding bits here. Silly. :-) */
315
316 pskb_trim(skb, skb->len - alen - padlen - 2);
317 __skb_pull(skb, hlen);
318 if (x->props.mode == XFRM_MODE_TUNNEL)
319 skb_reset_transport_header(skb);
320 else
321 skb_set_transport_header(skb, -hdr_len);
322
323 err = nexthdr[1];
324
325 /* RFC4303: Drop dummy packets without any error */
326 if (err == IPPROTO_NONE)
327 err = -EINVAL;
328
329out:
330 return err;
331}
332
333static void esp_input_done(struct crypto_async_request *base, int err)
334{
335 struct sk_buff *skb = base->data;
336
337 xfrm_input_resume(skb, esp_input_done2(skb, err));
338}
339
340static void esp_input_restore_header(struct sk_buff *skb)
341{
342 esp_restore_header(skb, 0);
343 __skb_pull(skb, 4);
344}
345
346static void esp_input_done_esn(struct crypto_async_request *base, int err)
347{
348 struct sk_buff *skb = base->data;
349
350 esp_input_restore_header(skb);
351 esp_input_done(base, err);
352}
353
354static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
355{
356 struct ip_esp_hdr *esph;
357 struct crypto_aead *aead = x->data;
358 struct aead_request *req;
359 struct sk_buff *trailer;
360 int ivlen = crypto_aead_ivsize(aead);
361 int elen = skb->len - sizeof(*esph) - ivlen;
362 int nfrags;
363 int assoclen;
364 int seqhilen;
365 int ret = 0;
366 void *tmp;
367 __be32 *seqhi;
368 u8 *iv;
369 struct scatterlist *sg;
370
371 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
372 ret = -EINVAL;
373 goto out;
374 }
375
376 if (elen <= 0) {
377 ret = -EINVAL;
378 goto out;
379 }
380
381 nfrags = skb_cow_data(skb, 0, &trailer);
382 if (nfrags < 0) {
383 ret = -EINVAL;
384 goto out;
385 }
386
387 ret = -ENOMEM;
388
389 assoclen = sizeof(*esph);
390 seqhilen = 0;
391
392 if (x->props.flags & XFRM_STATE_ESN) {
393 seqhilen += sizeof(__be32);
394 assoclen += seqhilen;
395 }
396
397 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
398 if (!tmp)
399 goto out;
400
401 ESP_SKB_CB(skb)->tmp = tmp;
402 seqhi = esp_tmp_seqhi(tmp);
403 iv = esp_tmp_iv(aead, tmp, seqhilen);
404 req = esp_tmp_req(aead, iv);
405 sg = esp_req_sg(aead, req);
406
407 skb->ip_summed = CHECKSUM_NONE;
408
409 esph = (struct ip_esp_hdr *)skb->data;
410
411 aead_request_set_callback(req, 0, esp_input_done, skb);
412
413 /* For ESN we move the header forward by 4 bytes to
414 * accomodate the high bits. We will move it back after
415 * decryption.
416 */
417 if ((x->props.flags & XFRM_STATE_ESN)) {
418 esph = (void *)skb_push(skb, 4);
419 *seqhi = esph->spi;
420 esph->spi = esph->seq_no;
421 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.input.hi);
422 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
423 }
424
425 sg_init_table(sg, nfrags);
426 skb_to_sgvec(skb, sg, 0, skb->len);
427
428 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
429 aead_request_set_ad(req, assoclen);
430
431 ret = crypto_aead_decrypt(req);
432 if (ret == -EINPROGRESS)
433 goto out;
434
435 if ((x->props.flags & XFRM_STATE_ESN))
436 esp_input_restore_header(skb);
437
438 ret = esp_input_done2(skb, ret);
439
440out:
441 return ret;
442}
443
444static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
445{
446 struct crypto_aead *aead = x->data;
447 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
448 unsigned int net_adj;
449
450 if (x->props.mode != XFRM_MODE_TUNNEL)
451 net_adj = sizeof(struct ipv6hdr);
452 else
453 net_adj = 0;
454
455 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
456 net_adj) & ~(blksize - 1)) + net_adj - 2;
457}
458
459static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
460 u8 type, u8 code, int offset, __be32 info)
461{
462 struct net *net = dev_net(skb->dev);
463 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
464 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
465 struct xfrm_state *x;
466
467 if (type != ICMPV6_PKT_TOOBIG &&
468 type != NDISC_REDIRECT)
469 return 0;
470
471 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
472 esph->spi, IPPROTO_ESP, AF_INET6);
473 if (!x)
474 return 0;
475
476 if (type == NDISC_REDIRECT)
477 ip6_redirect(skb, net, skb->dev->ifindex, 0);
478 else
479 ip6_update_pmtu(skb, net, info, 0, 0);
480 xfrm_state_put(x);
481
482 return 0;
483}
484
485static void esp6_destroy(struct xfrm_state *x)
486{
487 struct crypto_aead *aead = x->data;
488
489 if (!aead)
490 return;
491
492 crypto_free_aead(aead);
493}
494
495static int esp_init_aead(struct xfrm_state *x)
496{
497 char aead_name[CRYPTO_MAX_ALG_NAME];
498 struct crypto_aead *aead;
499 int err;
500
501 err = -ENAMETOOLONG;
502 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
503 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
504 goto error;
505
506 aead = crypto_alloc_aead(aead_name, 0, 0);
507 err = PTR_ERR(aead);
508 if (IS_ERR(aead))
509 goto error;
510
511 x->data = aead;
512
513 err = crypto_aead_setkey(aead, x->aead->alg_key,
514 (x->aead->alg_key_len + 7) / 8);
515 if (err)
516 goto error;
517
518 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
519 if (err)
520 goto error;
521
522error:
523 return err;
524}
525
526static int esp_init_authenc(struct xfrm_state *x)
527{
528 struct crypto_aead *aead;
529 struct crypto_authenc_key_param *param;
530 struct rtattr *rta;
531 char *key;
532 char *p;
533 char authenc_name[CRYPTO_MAX_ALG_NAME];
534 unsigned int keylen;
535 int err;
536
537 err = -EINVAL;
538 if (!x->ealg)
539 goto error;
540
541 err = -ENAMETOOLONG;
542
543 if ((x->props.flags & XFRM_STATE_ESN)) {
544 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
545 "%s%sauthencesn(%s,%s)%s",
546 x->geniv ?: "", x->geniv ? "(" : "",
547 x->aalg ? x->aalg->alg_name : "digest_null",
548 x->ealg->alg_name,
549 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
550 goto error;
551 } else {
552 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
553 "%s%sauthenc(%s,%s)%s",
554 x->geniv ?: "", x->geniv ? "(" : "",
555 x->aalg ? x->aalg->alg_name : "digest_null",
556 x->ealg->alg_name,
557 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
558 goto error;
559 }
560
561 aead = crypto_alloc_aead(authenc_name, 0, 0);
562 err = PTR_ERR(aead);
563 if (IS_ERR(aead))
564 goto error;
565
566 x->data = aead;
567
568 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
569 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
570 err = -ENOMEM;
571 key = kmalloc(keylen, GFP_KERNEL);
572 if (!key)
573 goto error;
574
575 p = key;
576 rta = (void *)p;
577 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
578 rta->rta_len = RTA_LENGTH(sizeof(*param));
579 param = RTA_DATA(rta);
580 p += RTA_SPACE(sizeof(*param));
581
582 if (x->aalg) {
583 struct xfrm_algo_desc *aalg_desc;
584
585 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
586 p += (x->aalg->alg_key_len + 7) / 8;
587
588 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
589 BUG_ON(!aalg_desc);
590
591 err = -EINVAL;
592 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
593 crypto_aead_authsize(aead)) {
594 pr_info("ESP: %s digestsize %u != %hu\n",
595 x->aalg->alg_name,
596 crypto_aead_authsize(aead),
597 aalg_desc->uinfo.auth.icv_fullbits / 8);
598 goto free_key;
599 }
600
601 err = crypto_aead_setauthsize(
602 aead, x->aalg->alg_trunc_len / 8);
603 if (err)
604 goto free_key;
605 }
606
607 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
608 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
609
610 err = crypto_aead_setkey(aead, key, keylen);
611
612free_key:
613 kfree(key);
614
615error:
616 return err;
617}
618
619static int esp6_init_state(struct xfrm_state *x)
620{
621 struct crypto_aead *aead;
622 u32 align;
623 int err;
624
625 if (x->encap)
626 return -EINVAL;
627
628 x->data = NULL;
629
630 if (x->aead)
631 err = esp_init_aead(x);
632 else
633 err = esp_init_authenc(x);
634
635 if (err)
636 goto error;
637
638 aead = x->data;
639
640 x->props.header_len = sizeof(struct ip_esp_hdr) +
641 crypto_aead_ivsize(aead);
642 switch (x->props.mode) {
643 case XFRM_MODE_BEET:
644 if (x->sel.family != AF_INET6)
645 x->props.header_len += IPV4_BEET_PHMAXLEN +
646 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
647 break;
648 case XFRM_MODE_TRANSPORT:
649 break;
650 case XFRM_MODE_TUNNEL:
651 x->props.header_len += sizeof(struct ipv6hdr);
652 break;
653 default:
654 goto error;
655 }
656
657 align = ALIGN(crypto_aead_blocksize(aead), 4);
658 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
659
660error:
661 return err;
662}
663
664static int esp6_rcv_cb(struct sk_buff *skb, int err)
665{
666 return 0;
667}
668
669static const struct xfrm_type esp6_type = {
670 .description = "ESP6",
671 .owner = THIS_MODULE,
672 .proto = IPPROTO_ESP,
673 .flags = XFRM_TYPE_REPLAY_PROT,
674 .init_state = esp6_init_state,
675 .destructor = esp6_destroy,
676 .get_mtu = esp6_get_mtu,
677 .input = esp6_input,
678 .output = esp6_output,
679 .hdr_offset = xfrm6_find_1stfragopt,
680};
681
682static struct xfrm6_protocol esp6_protocol = {
683 .handler = xfrm6_rcv,
684 .cb_handler = esp6_rcv_cb,
685 .err_handler = esp6_err,
686 .priority = 0,
687};
688
689static int __init esp6_init(void)
690{
691 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
692 pr_info("%s: can't add xfrm type\n", __func__);
693 return -EAGAIN;
694 }
695 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
696 pr_info("%s: can't add protocol\n", __func__);
697 xfrm_unregister_type(&esp6_type, AF_INET6);
698 return -EAGAIN;
699 }
700
701 return 0;
702}
703
704static void __exit esp6_fini(void)
705{
706 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
707 pr_info("%s: can't remove protocol\n", __func__);
708 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
709 pr_info("%s: can't remove xfrm type\n", __func__);
710}
711
712module_init(esp6_init);
713module_exit(esp6_fini);
714
715MODULE_LICENSE("GPL");
716MODULE_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_route.h>
30#include <net/icmp.h>
31#include <net/ipv6.h>
32#include <net/protocol.h>
33#include <linux/icmpv6.h>
34
35#include <linux/highmem.h>
36
37struct esp_skb_cb {
38 struct xfrm_skb_cb xfrm;
39 void *tmp;
40};
41
42#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
43
44/*
45 * Allocate an AEAD request structure with extra space for SG and IV.
46 *
47 * For alignment considerations the upper 32 bits of the sequence number are
48 * placed at the front, if present. Followed by the IV, the request and finally
49 * the SG list.
50 *
51 * TODO: Use spare space in skb for this where possible.
52 */
53static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
54{
55 unsigned int len;
56
57 len = seqihlen;
58
59 len += crypto_aead_ivsize(aead);
60
61 if (len) {
62 len += crypto_aead_alignmask(aead) &
63 ~(crypto_tfm_ctx_alignment() - 1);
64 len = ALIGN(len, crypto_tfm_ctx_alignment());
65 }
66
67 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
68 len = ALIGN(len, __alignof__(struct scatterlist));
69
70 len += sizeof(struct scatterlist) * nfrags;
71
72 return kmalloc(len, GFP_ATOMIC);
73}
74
75static inline __be32 *esp_tmp_seqhi(void *tmp)
76{
77 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
78}
79
80static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
81{
82 return crypto_aead_ivsize(aead) ?
83 PTR_ALIGN((u8 *)tmp + seqhilen,
84 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
85}
86
87static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
88{
89 struct aead_request *req;
90
91 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
92 crypto_tfm_ctx_alignment());
93 aead_request_set_tfm(req, aead);
94 return req;
95}
96
97static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
98 struct aead_request *req)
99{
100 return (void *)ALIGN((unsigned long)(req + 1) +
101 crypto_aead_reqsize(aead),
102 __alignof__(struct scatterlist));
103}
104
105static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
106{
107 struct crypto_aead *aead = x->data;
108 int seqhilen = 0;
109 u8 *iv;
110 struct aead_request *req;
111 struct scatterlist *sg;
112
113 if (x->props.flags & XFRM_STATE_ESN)
114 seqhilen += sizeof(__be32);
115
116 iv = esp_tmp_iv(aead, tmp, seqhilen);
117 req = esp_tmp_req(aead, iv);
118
119 /* Unref skb_frag_pages in the src scatterlist if necessary.
120 * Skip the first sg which comes from skb->data.
121 */
122 if (req->src != req->dst)
123 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
124 put_page(sg_page(sg));
125}
126
127static void esp_output_done(struct crypto_async_request *base, int err)
128{
129 struct sk_buff *skb = base->data;
130 struct xfrm_offload *xo = xfrm_offload(skb);
131 void *tmp;
132 struct xfrm_state *x;
133
134 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
135 struct sec_path *sp = skb_sec_path(skb);
136
137 x = sp->xvec[sp->len - 1];
138 } else {
139 x = skb_dst(skb)->xfrm;
140 }
141
142 tmp = ESP_SKB_CB(skb)->tmp;
143 esp_ssg_unref(x, tmp);
144 kfree(tmp);
145
146 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
147 if (err) {
148 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
149 kfree_skb(skb);
150 return;
151 }
152
153 skb_push(skb, skb->data - skb_mac_header(skb));
154 secpath_reset(skb);
155 xfrm_dev_resume(skb);
156 } else {
157 xfrm_output_resume(skb, err);
158 }
159}
160
161/* Move ESP header back into place. */
162static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
163{
164 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
165 void *tmp = ESP_SKB_CB(skb)->tmp;
166 __be32 *seqhi = esp_tmp_seqhi(tmp);
167
168 esph->seq_no = esph->spi;
169 esph->spi = *seqhi;
170}
171
172static void esp_output_restore_header(struct sk_buff *skb)
173{
174 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
175}
176
177static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
178 struct xfrm_state *x,
179 struct ip_esp_hdr *esph,
180 __be32 *seqhi)
181{
182 /* For ESN we move the header forward by 4 bytes to
183 * accomodate the high bits. We will move it back after
184 * encryption.
185 */
186 if ((x->props.flags & XFRM_STATE_ESN)) {
187 struct xfrm_offload *xo = xfrm_offload(skb);
188
189 esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
190 *seqhi = esph->spi;
191 if (xo)
192 esph->seq_no = htonl(xo->seq.hi);
193 else
194 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
195 }
196
197 esph->spi = x->id.spi;
198
199 return esph;
200}
201
202static void esp_output_done_esn(struct crypto_async_request *base, int err)
203{
204 struct sk_buff *skb = base->data;
205
206 esp_output_restore_header(skb);
207 esp_output_done(base, err);
208}
209
210static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
211{
212 /* Fill padding... */
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] = proto;
224}
225
226int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
227{
228 u8 *tail;
229 u8 *vaddr;
230 int nfrags;
231 struct page *page;
232 struct sk_buff *trailer;
233 int tailen = esp->tailen;
234
235 if (!skb_cloned(skb)) {
236 if (tailen <= skb_tailroom(skb)) {
237 nfrags = 1;
238 trailer = skb;
239 tail = skb_tail_pointer(trailer);
240
241 goto skip_cow;
242 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
243 && !skb_has_frag_list(skb)) {
244 int allocsize;
245 struct sock *sk = skb->sk;
246 struct page_frag *pfrag = &x->xfrag;
247
248 esp->inplace = false;
249
250 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
251
252 spin_lock_bh(&x->lock);
253
254 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
255 spin_unlock_bh(&x->lock);
256 goto cow;
257 }
258
259 page = pfrag->page;
260 get_page(page);
261
262 vaddr = kmap_atomic(page);
263
264 tail = vaddr + pfrag->offset;
265
266 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
267
268 kunmap_atomic(vaddr);
269
270 nfrags = skb_shinfo(skb)->nr_frags;
271
272 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
273 tailen);
274 skb_shinfo(skb)->nr_frags = ++nfrags;
275
276 pfrag->offset = pfrag->offset + allocsize;
277
278 spin_unlock_bh(&x->lock);
279
280 nfrags++;
281
282 skb->len += tailen;
283 skb->data_len += tailen;
284 skb->truesize += tailen;
285 if (sk && sk_fullsock(sk))
286 refcount_add(tailen, &sk->sk_wmem_alloc);
287
288 goto out;
289 }
290 }
291
292cow:
293 nfrags = skb_cow_data(skb, tailen, &trailer);
294 if (nfrags < 0)
295 goto out;
296 tail = skb_tail_pointer(trailer);
297
298skip_cow:
299 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
300 pskb_put(skb, trailer, tailen);
301
302out:
303 return nfrags;
304}
305EXPORT_SYMBOL_GPL(esp6_output_head);
306
307int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
308{
309 u8 *iv;
310 int alen;
311 void *tmp;
312 int ivlen;
313 int assoclen;
314 int seqhilen;
315 __be32 *seqhi;
316 struct page *page;
317 struct ip_esp_hdr *esph;
318 struct aead_request *req;
319 struct crypto_aead *aead;
320 struct scatterlist *sg, *dsg;
321 int err = -ENOMEM;
322
323 assoclen = sizeof(struct ip_esp_hdr);
324 seqhilen = 0;
325
326 if (x->props.flags & XFRM_STATE_ESN) {
327 seqhilen += sizeof(__be32);
328 assoclen += sizeof(__be32);
329 }
330
331 aead = x->data;
332 alen = crypto_aead_authsize(aead);
333 ivlen = crypto_aead_ivsize(aead);
334
335 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
336 if (!tmp)
337 goto error;
338
339 seqhi = esp_tmp_seqhi(tmp);
340 iv = esp_tmp_iv(aead, tmp, seqhilen);
341 req = esp_tmp_req(aead, iv);
342 sg = esp_req_sg(aead, req);
343
344 if (esp->inplace)
345 dsg = sg;
346 else
347 dsg = &sg[esp->nfrags];
348
349 esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
350
351 sg_init_table(sg, esp->nfrags);
352 err = skb_to_sgvec(skb, sg,
353 (unsigned char *)esph - skb->data,
354 assoclen + ivlen + esp->clen + alen);
355 if (unlikely(err < 0))
356 goto error_free;
357
358 if (!esp->inplace) {
359 int allocsize;
360 struct page_frag *pfrag = &x->xfrag;
361
362 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
363
364 spin_lock_bh(&x->lock);
365 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
366 spin_unlock_bh(&x->lock);
367 goto error_free;
368 }
369
370 skb_shinfo(skb)->nr_frags = 1;
371
372 page = pfrag->page;
373 get_page(page);
374 /* replace page frags in skb with new page */
375 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
376 pfrag->offset = pfrag->offset + allocsize;
377 spin_unlock_bh(&x->lock);
378
379 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
380 err = skb_to_sgvec(skb, dsg,
381 (unsigned char *)esph - skb->data,
382 assoclen + ivlen + esp->clen + alen);
383 if (unlikely(err < 0))
384 goto error_free;
385 }
386
387 if ((x->props.flags & XFRM_STATE_ESN))
388 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
389 else
390 aead_request_set_callback(req, 0, esp_output_done, skb);
391
392 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
393 aead_request_set_ad(req, assoclen);
394
395 memset(iv, 0, ivlen);
396 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
397 min(ivlen, 8));
398
399 ESP_SKB_CB(skb)->tmp = tmp;
400 err = crypto_aead_encrypt(req);
401
402 switch (err) {
403 case -EINPROGRESS:
404 goto error;
405
406 case -ENOSPC:
407 err = NET_XMIT_DROP;
408 break;
409
410 case 0:
411 if ((x->props.flags & XFRM_STATE_ESN))
412 esp_output_restore_header(skb);
413 }
414
415 if (sg != dsg)
416 esp_ssg_unref(x, tmp);
417
418error_free:
419 kfree(tmp);
420error:
421 return err;
422}
423EXPORT_SYMBOL_GPL(esp6_output_tail);
424
425static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
426{
427 int alen;
428 int blksize;
429 struct ip_esp_hdr *esph;
430 struct crypto_aead *aead;
431 struct esp_info esp;
432
433 esp.inplace = true;
434
435 esp.proto = *skb_mac_header(skb);
436 *skb_mac_header(skb) = IPPROTO_ESP;
437
438 /* skb is pure payload to encrypt */
439
440 aead = x->data;
441 alen = crypto_aead_authsize(aead);
442
443 esp.tfclen = 0;
444 if (x->tfcpad) {
445 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
446 u32 padto;
447
448 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
449 if (skb->len < padto)
450 esp.tfclen = padto - skb->len;
451 }
452 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
453 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
454 esp.plen = esp.clen - skb->len - esp.tfclen;
455 esp.tailen = esp.tfclen + esp.plen + alen;
456
457 esp.nfrags = esp6_output_head(x, skb, &esp);
458 if (esp.nfrags < 0)
459 return esp.nfrags;
460
461 esph = ip_esp_hdr(skb);
462 esph->spi = x->id.spi;
463
464 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
465 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
466 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
467
468 skb_push(skb, -skb_network_offset(skb));
469
470 return esp6_output_tail(x, skb, &esp);
471}
472
473static inline int esp_remove_trailer(struct sk_buff *skb)
474{
475 struct xfrm_state *x = xfrm_input_state(skb);
476 struct xfrm_offload *xo = xfrm_offload(skb);
477 struct crypto_aead *aead = x->data;
478 int alen, hlen, elen;
479 int padlen, trimlen;
480 __wsum csumdiff;
481 u8 nexthdr[2];
482 int ret;
483
484 alen = crypto_aead_authsize(aead);
485 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
486 elen = skb->len - hlen;
487
488 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
489 ret = xo->proto;
490 goto out;
491 }
492
493 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
494 BUG_ON(ret);
495
496 ret = -EINVAL;
497 padlen = nexthdr[0];
498 if (padlen + 2 + alen >= elen) {
499 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
500 padlen + 2, elen - alen);
501 goto out;
502 }
503
504 trimlen = alen + padlen + 2;
505 if (skb->ip_summed == CHECKSUM_COMPLETE) {
506 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
507 skb->csum = csum_block_sub(skb->csum, csumdiff,
508 skb->len - trimlen);
509 }
510 pskb_trim(skb, skb->len - trimlen);
511
512 ret = nexthdr[1];
513
514out:
515 return ret;
516}
517
518int esp6_input_done2(struct sk_buff *skb, int err)
519{
520 struct xfrm_state *x = xfrm_input_state(skb);
521 struct xfrm_offload *xo = xfrm_offload(skb);
522 struct crypto_aead *aead = x->data;
523 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
524 int hdr_len = skb_network_header_len(skb);
525
526 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
527 kfree(ESP_SKB_CB(skb)->tmp);
528
529 if (unlikely(err))
530 goto out;
531
532 err = esp_remove_trailer(skb);
533 if (unlikely(err < 0))
534 goto out;
535
536 skb_postpull_rcsum(skb, skb_network_header(skb),
537 skb_network_header_len(skb));
538 skb_pull_rcsum(skb, hlen);
539 if (x->props.mode == XFRM_MODE_TUNNEL)
540 skb_reset_transport_header(skb);
541 else
542 skb_set_transport_header(skb, -hdr_len);
543
544 /* RFC4303: Drop dummy packets without any error */
545 if (err == IPPROTO_NONE)
546 err = -EINVAL;
547
548out:
549 return err;
550}
551EXPORT_SYMBOL_GPL(esp6_input_done2);
552
553static void esp_input_done(struct crypto_async_request *base, int err)
554{
555 struct sk_buff *skb = base->data;
556
557 xfrm_input_resume(skb, esp6_input_done2(skb, err));
558}
559
560static void esp_input_restore_header(struct sk_buff *skb)
561{
562 esp_restore_header(skb, 0);
563 __skb_pull(skb, 4);
564}
565
566static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
567{
568 struct xfrm_state *x = xfrm_input_state(skb);
569
570 /* For ESN we move the header forward by 4 bytes to
571 * accomodate the high bits. We will move it back after
572 * decryption.
573 */
574 if ((x->props.flags & XFRM_STATE_ESN)) {
575 struct ip_esp_hdr *esph = skb_push(skb, 4);
576
577 *seqhi = esph->spi;
578 esph->spi = esph->seq_no;
579 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
580 }
581}
582
583static void esp_input_done_esn(struct crypto_async_request *base, int err)
584{
585 struct sk_buff *skb = base->data;
586
587 esp_input_restore_header(skb);
588 esp_input_done(base, err);
589}
590
591static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
592{
593 struct crypto_aead *aead = x->data;
594 struct aead_request *req;
595 struct sk_buff *trailer;
596 int ivlen = crypto_aead_ivsize(aead);
597 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
598 int nfrags;
599 int assoclen;
600 int seqhilen;
601 int ret = 0;
602 void *tmp;
603 __be32 *seqhi;
604 u8 *iv;
605 struct scatterlist *sg;
606
607 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
608 ret = -EINVAL;
609 goto out;
610 }
611
612 if (elen <= 0) {
613 ret = -EINVAL;
614 goto out;
615 }
616
617 assoclen = sizeof(struct ip_esp_hdr);
618 seqhilen = 0;
619
620 if (x->props.flags & XFRM_STATE_ESN) {
621 seqhilen += sizeof(__be32);
622 assoclen += seqhilen;
623 }
624
625 if (!skb_cloned(skb)) {
626 if (!skb_is_nonlinear(skb)) {
627 nfrags = 1;
628
629 goto skip_cow;
630 } else if (!skb_has_frag_list(skb)) {
631 nfrags = skb_shinfo(skb)->nr_frags;
632 nfrags++;
633
634 goto skip_cow;
635 }
636 }
637
638 nfrags = skb_cow_data(skb, 0, &trailer);
639 if (nfrags < 0) {
640 ret = -EINVAL;
641 goto out;
642 }
643
644skip_cow:
645 ret = -ENOMEM;
646 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
647 if (!tmp)
648 goto out;
649
650 ESP_SKB_CB(skb)->tmp = tmp;
651 seqhi = esp_tmp_seqhi(tmp);
652 iv = esp_tmp_iv(aead, tmp, seqhilen);
653 req = esp_tmp_req(aead, iv);
654 sg = esp_req_sg(aead, req);
655
656 esp_input_set_header(skb, seqhi);
657
658 sg_init_table(sg, nfrags);
659 ret = skb_to_sgvec(skb, sg, 0, skb->len);
660 if (unlikely(ret < 0)) {
661 kfree(tmp);
662 goto out;
663 }
664
665 skb->ip_summed = CHECKSUM_NONE;
666
667 if ((x->props.flags & XFRM_STATE_ESN))
668 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
669 else
670 aead_request_set_callback(req, 0, esp_input_done, skb);
671
672 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
673 aead_request_set_ad(req, assoclen);
674
675 ret = crypto_aead_decrypt(req);
676 if (ret == -EINPROGRESS)
677 goto out;
678
679 if ((x->props.flags & XFRM_STATE_ESN))
680 esp_input_restore_header(skb);
681
682 ret = esp6_input_done2(skb, ret);
683
684out:
685 return ret;
686}
687
688static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
689 u8 type, u8 code, int offset, __be32 info)
690{
691 struct net *net = dev_net(skb->dev);
692 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
693 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
694 struct xfrm_state *x;
695
696 if (type != ICMPV6_PKT_TOOBIG &&
697 type != NDISC_REDIRECT)
698 return 0;
699
700 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
701 esph->spi, IPPROTO_ESP, AF_INET6);
702 if (!x)
703 return 0;
704
705 if (type == NDISC_REDIRECT)
706 ip6_redirect(skb, net, skb->dev->ifindex, 0,
707 sock_net_uid(net, NULL));
708 else
709 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
710 xfrm_state_put(x);
711
712 return 0;
713}
714
715static void esp6_destroy(struct xfrm_state *x)
716{
717 struct crypto_aead *aead = x->data;
718
719 if (!aead)
720 return;
721
722 crypto_free_aead(aead);
723}
724
725static int esp_init_aead(struct xfrm_state *x)
726{
727 char aead_name[CRYPTO_MAX_ALG_NAME];
728 struct crypto_aead *aead;
729 int err;
730
731 err = -ENAMETOOLONG;
732 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
733 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
734 goto error;
735
736 aead = crypto_alloc_aead(aead_name, 0, 0);
737 err = PTR_ERR(aead);
738 if (IS_ERR(aead))
739 goto error;
740
741 x->data = aead;
742
743 err = crypto_aead_setkey(aead, x->aead->alg_key,
744 (x->aead->alg_key_len + 7) / 8);
745 if (err)
746 goto error;
747
748 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
749 if (err)
750 goto error;
751
752error:
753 return err;
754}
755
756static int esp_init_authenc(struct xfrm_state *x)
757{
758 struct crypto_aead *aead;
759 struct crypto_authenc_key_param *param;
760 struct rtattr *rta;
761 char *key;
762 char *p;
763 char authenc_name[CRYPTO_MAX_ALG_NAME];
764 unsigned int keylen;
765 int err;
766
767 err = -EINVAL;
768 if (!x->ealg)
769 goto error;
770
771 err = -ENAMETOOLONG;
772
773 if ((x->props.flags & XFRM_STATE_ESN)) {
774 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
775 "%s%sauthencesn(%s,%s)%s",
776 x->geniv ?: "", x->geniv ? "(" : "",
777 x->aalg ? x->aalg->alg_name : "digest_null",
778 x->ealg->alg_name,
779 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
780 goto error;
781 } else {
782 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
783 "%s%sauthenc(%s,%s)%s",
784 x->geniv ?: "", x->geniv ? "(" : "",
785 x->aalg ? x->aalg->alg_name : "digest_null",
786 x->ealg->alg_name,
787 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
788 goto error;
789 }
790
791 aead = crypto_alloc_aead(authenc_name, 0, 0);
792 err = PTR_ERR(aead);
793 if (IS_ERR(aead))
794 goto error;
795
796 x->data = aead;
797
798 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
799 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
800 err = -ENOMEM;
801 key = kmalloc(keylen, GFP_KERNEL);
802 if (!key)
803 goto error;
804
805 p = key;
806 rta = (void *)p;
807 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
808 rta->rta_len = RTA_LENGTH(sizeof(*param));
809 param = RTA_DATA(rta);
810 p += RTA_SPACE(sizeof(*param));
811
812 if (x->aalg) {
813 struct xfrm_algo_desc *aalg_desc;
814
815 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
816 p += (x->aalg->alg_key_len + 7) / 8;
817
818 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
819 BUG_ON(!aalg_desc);
820
821 err = -EINVAL;
822 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
823 crypto_aead_authsize(aead)) {
824 pr_info("ESP: %s digestsize %u != %hu\n",
825 x->aalg->alg_name,
826 crypto_aead_authsize(aead),
827 aalg_desc->uinfo.auth.icv_fullbits / 8);
828 goto free_key;
829 }
830
831 err = crypto_aead_setauthsize(
832 aead, x->aalg->alg_trunc_len / 8);
833 if (err)
834 goto free_key;
835 }
836
837 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
838 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
839
840 err = crypto_aead_setkey(aead, key, keylen);
841
842free_key:
843 kfree(key);
844
845error:
846 return err;
847}
848
849static int esp6_init_state(struct xfrm_state *x)
850{
851 struct crypto_aead *aead;
852 u32 align;
853 int err;
854
855 if (x->encap)
856 return -EINVAL;
857
858 x->data = NULL;
859
860 if (x->aead)
861 err = esp_init_aead(x);
862 else
863 err = esp_init_authenc(x);
864
865 if (err)
866 goto error;
867
868 aead = x->data;
869
870 x->props.header_len = sizeof(struct ip_esp_hdr) +
871 crypto_aead_ivsize(aead);
872 switch (x->props.mode) {
873 case XFRM_MODE_BEET:
874 if (x->sel.family != AF_INET6)
875 x->props.header_len += IPV4_BEET_PHMAXLEN +
876 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
877 break;
878 default:
879 case XFRM_MODE_TRANSPORT:
880 break;
881 case XFRM_MODE_TUNNEL:
882 x->props.header_len += sizeof(struct ipv6hdr);
883 break;
884 }
885
886 align = ALIGN(crypto_aead_blocksize(aead), 4);
887 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
888
889error:
890 return err;
891}
892
893static int esp6_rcv_cb(struct sk_buff *skb, int err)
894{
895 return 0;
896}
897
898static const struct xfrm_type esp6_type = {
899 .description = "ESP6",
900 .owner = THIS_MODULE,
901 .proto = IPPROTO_ESP,
902 .flags = XFRM_TYPE_REPLAY_PROT,
903 .init_state = esp6_init_state,
904 .destructor = esp6_destroy,
905 .input = esp6_input,
906 .output = esp6_output,
907 .hdr_offset = xfrm6_find_1stfragopt,
908};
909
910static struct xfrm6_protocol esp6_protocol = {
911 .handler = xfrm6_rcv,
912 .cb_handler = esp6_rcv_cb,
913 .err_handler = esp6_err,
914 .priority = 0,
915};
916
917static int __init esp6_init(void)
918{
919 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
920 pr_info("%s: can't add xfrm type\n", __func__);
921 return -EAGAIN;
922 }
923 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
924 pr_info("%s: can't add protocol\n", __func__);
925 xfrm_unregister_type(&esp6_type, AF_INET6);
926 return -EAGAIN;
927 }
928
929 return 0;
930}
931
932static void __exit esp6_fini(void)
933{
934 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
935 pr_info("%s: can't remove protocol\n", __func__);
936 xfrm_unregister_type(&esp6_type, AF_INET6);
937}
938
939module_init(esp6_init);
940module_exit(esp6_fini);
941
942MODULE_LICENSE("GPL");
943MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);