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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, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Authors
19 *
20 * Mitsuru KANDA @USAGI : IPv6 Support
21 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
23 *
24 * This file is derived from net/ipv4/esp.c
25 */
26
27#include <crypto/aead.h>
28#include <crypto/authenc.h>
29#include <linux/err.h>
30#include <linux/module.h>
31#include <net/ip.h>
32#include <net/xfrm.h>
33#include <net/esp.h>
34#include <linux/scatterlist.h>
35#include <linux/kernel.h>
36#include <linux/pfkeyv2.h>
37#include <linux/random.h>
38#include <linux/slab.h>
39#include <linux/spinlock.h>
40#include <net/icmp.h>
41#include <net/ipv6.h>
42#include <net/protocol.h>
43#include <linux/icmpv6.h>
44
45struct esp_skb_cb {
46 struct xfrm_skb_cb xfrm;
47 void *tmp;
48};
49
50#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
51
52static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
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_givcrypt_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 __be32 *esp_tmp_seqhi(void *tmp)
86{
87 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
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_givcrypt_request *esp_tmp_givreq(
98 struct crypto_aead *aead, u8 *iv)
99{
100 struct aead_givcrypt_request *req;
101
102 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
103 crypto_tfm_ctx_alignment());
104 aead_givcrypt_set_tfm(req, aead);
105 return req;
106}
107
108static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
109{
110 struct aead_request *req;
111
112 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
113 crypto_tfm_ctx_alignment());
114 aead_request_set_tfm(req, aead);
115 return req;
116}
117
118static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
119 struct aead_request *req)
120{
121 return (void *)ALIGN((unsigned long)(req + 1) +
122 crypto_aead_reqsize(aead),
123 __alignof__(struct scatterlist));
124}
125
126static inline struct scatterlist *esp_givreq_sg(
127 struct crypto_aead *aead, struct aead_givcrypt_request *req)
128{
129 return (void *)ALIGN((unsigned long)(req + 1) +
130 crypto_aead_reqsize(aead),
131 __alignof__(struct scatterlist));
132}
133
134static void esp_output_done(struct crypto_async_request *base, int err)
135{
136 struct sk_buff *skb = base->data;
137
138 kfree(ESP_SKB_CB(skb)->tmp);
139 xfrm_output_resume(skb, err);
140}
141
142static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
143{
144 int err;
145 struct ip_esp_hdr *esph;
146 struct crypto_aead *aead;
147 struct aead_givcrypt_request *req;
148 struct scatterlist *sg;
149 struct scatterlist *asg;
150 struct sk_buff *trailer;
151 void *tmp;
152 int blksize;
153 int clen;
154 int alen;
155 int plen;
156 int tfclen;
157 int nfrags;
158 int assoclen;
159 int sglists;
160 int seqhilen;
161 u8 *iv;
162 u8 *tail;
163 __be32 *seqhi;
164 struct esp_data *esp = x->data;
165
166 /* skb is pure payload to encrypt */
167 err = -ENOMEM;
168
169 aead = esp->aead;
170 alen = crypto_aead_authsize(aead);
171
172 tfclen = 0;
173 if (x->tfcpad) {
174 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
175 u32 padto;
176
177 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
178 if (skb->len < padto)
179 tfclen = padto - skb->len;
180 }
181 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
182 clen = ALIGN(skb->len + 2 + tfclen, blksize);
183 if (esp->padlen)
184 clen = ALIGN(clen, esp->padlen);
185 plen = clen - skb->len - tfclen;
186
187 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
188 if (err < 0)
189 goto error;
190 nfrags = err;
191
192 assoclen = sizeof(*esph);
193 sglists = 1;
194 seqhilen = 0;
195
196 if (x->props.flags & XFRM_STATE_ESN) {
197 sglists += 2;
198 seqhilen += sizeof(__be32);
199 assoclen += seqhilen;
200 }
201
202 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
203 if (!tmp)
204 goto error;
205
206 seqhi = esp_tmp_seqhi(tmp);
207 iv = esp_tmp_iv(aead, tmp, seqhilen);
208 req = esp_tmp_givreq(aead, iv);
209 asg = esp_givreq_sg(aead, req);
210 sg = asg + sglists;
211
212 /* Fill padding... */
213 tail = skb_tail_pointer(trailer);
214 if (tfclen) {
215 memset(tail, 0, tfclen);
216 tail += tfclen;
217 }
218 do {
219 int i;
220 for (i = 0; i < plen - 2; i++)
221 tail[i] = i + 1;
222 } while (0);
223 tail[plen - 2] = plen - 2;
224 tail[plen - 1] = *skb_mac_header(skb);
225 pskb_put(skb, trailer, clen - skb->len + alen);
226
227 skb_push(skb, -skb_network_offset(skb));
228 esph = ip_esp_hdr(skb);
229 *skb_mac_header(skb) = IPPROTO_ESP;
230
231 esph->spi = x->id.spi;
232 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
233
234 sg_init_table(sg, nfrags);
235 skb_to_sgvec(skb, sg,
236 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
237 clen + alen);
238
239 if ((x->props.flags & XFRM_STATE_ESN)) {
240 sg_init_table(asg, 3);
241 sg_set_buf(asg, &esph->spi, sizeof(__be32));
242 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
243 sg_set_buf(asg + 1, seqhi, seqhilen);
244 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
245 } else
246 sg_init_one(asg, esph, sizeof(*esph));
247
248 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
249 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
250 aead_givcrypt_set_assoc(req, asg, assoclen);
251 aead_givcrypt_set_giv(req, esph->enc_data,
252 XFRM_SKB_CB(skb)->seq.output.low);
253
254 ESP_SKB_CB(skb)->tmp = tmp;
255 err = crypto_aead_givencrypt(req);
256 if (err == -EINPROGRESS)
257 goto error;
258
259 if (err == -EBUSY)
260 err = NET_XMIT_DROP;
261
262 kfree(tmp);
263
264error:
265 return err;
266}
267
268static int esp_input_done2(struct sk_buff *skb, int err)
269{
270 struct xfrm_state *x = xfrm_input_state(skb);
271 struct esp_data *esp = x->data;
272 struct crypto_aead *aead = esp->aead;
273 int alen = crypto_aead_authsize(aead);
274 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
275 int elen = skb->len - hlen;
276 int hdr_len = skb_network_header_len(skb);
277 int padlen;
278 u8 nexthdr[2];
279
280 kfree(ESP_SKB_CB(skb)->tmp);
281
282 if (unlikely(err))
283 goto out;
284
285 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
286 BUG();
287
288 err = -EINVAL;
289 padlen = nexthdr[0];
290 if (padlen + 2 + alen >= elen) {
291 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
292 "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
293 goto out;
294 }
295
296 /* ... check padding bits here. Silly. :-) */
297
298 pskb_trim(skb, skb->len - alen - padlen - 2);
299 __skb_pull(skb, hlen);
300 skb_set_transport_header(skb, -hdr_len);
301
302 err = nexthdr[1];
303
304 /* RFC4303: Drop dummy packets without any error */
305 if (err == IPPROTO_NONE)
306 err = -EINVAL;
307
308out:
309 return err;
310}
311
312static void esp_input_done(struct crypto_async_request *base, int err)
313{
314 struct sk_buff *skb = base->data;
315
316 xfrm_input_resume(skb, esp_input_done2(skb, err));
317}
318
319static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
320{
321 struct ip_esp_hdr *esph;
322 struct esp_data *esp = x->data;
323 struct crypto_aead *aead = esp->aead;
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 esp_data *esp = x->data;
412 u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
413 u32 align = max_t(u32, blksize, esp->padlen);
414 u32 rem;
415
416 mtu -= x->props.header_len + crypto_aead_authsize(esp->aead);
417 rem = mtu & (align - 1);
418 mtu &= ~(align - 1);
419
420 if (x->props.mode != XFRM_MODE_TUNNEL) {
421 u32 padsize = ((blksize - 1) & 7) + 1;
422 mtu -= blksize - padsize;
423 mtu += min_t(u32, blksize - padsize, rem);
424 }
425
426 return mtu - 2;
427}
428
429static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
430 u8 type, u8 code, int offset, __be32 info)
431{
432 struct net *net = dev_net(skb->dev);
433 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
434 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
435 struct xfrm_state *x;
436
437 if (type != ICMPV6_DEST_UNREACH &&
438 type != ICMPV6_PKT_TOOBIG)
439 return;
440
441 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
442 esph->spi, IPPROTO_ESP, AF_INET6);
443 if (!x)
444 return;
445 printk(KERN_DEBUG "pmtu discovery on SA ESP/%08x/%pI6\n",
446 ntohl(esph->spi), &iph->daddr);
447 xfrm_state_put(x);
448}
449
450static void esp6_destroy(struct xfrm_state *x)
451{
452 struct esp_data *esp = x->data;
453
454 if (!esp)
455 return;
456
457 crypto_free_aead(esp->aead);
458 kfree(esp);
459}
460
461static int esp_init_aead(struct xfrm_state *x)
462{
463 struct esp_data *esp = x->data;
464 struct crypto_aead *aead;
465 int err;
466
467 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
468 err = PTR_ERR(aead);
469 if (IS_ERR(aead))
470 goto error;
471
472 esp->aead = aead;
473
474 err = crypto_aead_setkey(aead, x->aead->alg_key,
475 (x->aead->alg_key_len + 7) / 8);
476 if (err)
477 goto error;
478
479 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
480 if (err)
481 goto error;
482
483error:
484 return err;
485}
486
487static int esp_init_authenc(struct xfrm_state *x)
488{
489 struct esp_data *esp = x->data;
490 struct crypto_aead *aead;
491 struct crypto_authenc_key_param *param;
492 struct rtattr *rta;
493 char *key;
494 char *p;
495 char authenc_name[CRYPTO_MAX_ALG_NAME];
496 unsigned int keylen;
497 int err;
498
499 err = -EINVAL;
500 if (x->ealg == NULL)
501 goto error;
502
503 err = -ENAMETOOLONG;
504
505 if ((x->props.flags & XFRM_STATE_ESN)) {
506 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
507 "authencesn(%s,%s)",
508 x->aalg ? x->aalg->alg_name : "digest_null",
509 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
510 goto error;
511 } else {
512 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
513 "authenc(%s,%s)",
514 x->aalg ? x->aalg->alg_name : "digest_null",
515 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
516 goto error;
517 }
518
519 aead = crypto_alloc_aead(authenc_name, 0, 0);
520 err = PTR_ERR(aead);
521 if (IS_ERR(aead))
522 goto error;
523
524 esp->aead = aead;
525
526 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
527 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
528 err = -ENOMEM;
529 key = kmalloc(keylen, GFP_KERNEL);
530 if (!key)
531 goto error;
532
533 p = key;
534 rta = (void *)p;
535 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
536 rta->rta_len = RTA_LENGTH(sizeof(*param));
537 param = RTA_DATA(rta);
538 p += RTA_SPACE(sizeof(*param));
539
540 if (x->aalg) {
541 struct xfrm_algo_desc *aalg_desc;
542
543 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
544 p += (x->aalg->alg_key_len + 7) / 8;
545
546 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
547 BUG_ON(!aalg_desc);
548
549 err = -EINVAL;
550 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
551 crypto_aead_authsize(aead)) {
552 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
553 x->aalg->alg_name,
554 crypto_aead_authsize(aead),
555 aalg_desc->uinfo.auth.icv_fullbits/8);
556 goto free_key;
557 }
558
559 err = crypto_aead_setauthsize(
560 aead, x->aalg->alg_trunc_len / 8);
561 if (err)
562 goto free_key;
563 }
564
565 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
566 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
567
568 err = crypto_aead_setkey(aead, key, keylen);
569
570free_key:
571 kfree(key);
572
573error:
574 return err;
575}
576
577static int esp6_init_state(struct xfrm_state *x)
578{
579 struct esp_data *esp;
580 struct crypto_aead *aead;
581 u32 align;
582 int err;
583
584 if (x->encap)
585 return -EINVAL;
586
587 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
588 if (esp == NULL)
589 return -ENOMEM;
590
591 x->data = esp;
592
593 if (x->aead)
594 err = esp_init_aead(x);
595 else
596 err = esp_init_authenc(x);
597
598 if (err)
599 goto error;
600
601 aead = esp->aead;
602
603 esp->padlen = 0;
604
605 x->props.header_len = sizeof(struct ip_esp_hdr) +
606 crypto_aead_ivsize(aead);
607 switch (x->props.mode) {
608 case XFRM_MODE_BEET:
609 if (x->sel.family != AF_INET6)
610 x->props.header_len += IPV4_BEET_PHMAXLEN +
611 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
612 break;
613 case XFRM_MODE_TRANSPORT:
614 break;
615 case XFRM_MODE_TUNNEL:
616 x->props.header_len += sizeof(struct ipv6hdr);
617 break;
618 default:
619 goto error;
620 }
621
622 align = ALIGN(crypto_aead_blocksize(aead), 4);
623 if (esp->padlen)
624 align = max_t(u32, align, esp->padlen);
625 x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
626
627error:
628 return err;
629}
630
631static const struct xfrm_type esp6_type =
632{
633 .description = "ESP6",
634 .owner = THIS_MODULE,
635 .proto = IPPROTO_ESP,
636 .flags = XFRM_TYPE_REPLAY_PROT,
637 .init_state = esp6_init_state,
638 .destructor = esp6_destroy,
639 .get_mtu = esp6_get_mtu,
640 .input = esp6_input,
641 .output = esp6_output,
642 .hdr_offset = xfrm6_find_1stfragopt,
643};
644
645static const struct inet6_protocol esp6_protocol = {
646 .handler = xfrm6_rcv,
647 .err_handler = esp6_err,
648 .flags = INET6_PROTO_NOPOLICY,
649};
650
651static int __init esp6_init(void)
652{
653 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
654 printk(KERN_INFO "ipv6 esp init: can't add xfrm type\n");
655 return -EAGAIN;
656 }
657 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
658 printk(KERN_INFO "ipv6 esp init: can't add protocol\n");
659 xfrm_unregister_type(&esp6_type, AF_INET6);
660 return -EAGAIN;
661 }
662
663 return 0;
664}
665
666static void __exit esp6_fini(void)
667{
668 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
669 printk(KERN_INFO "ipv6 esp close: can't remove protocol\n");
670 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
671 printk(KERN_INFO "ipv6 esp close: can't remove xfrm type\n");
672}
673
674module_init(esp6_init);
675module_exit(esp6_fini);
676
677MODULE_LICENSE("GPL");
678MODULE_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 crypto_aead *aead = x->data;
118 int extralen = 0;
119 u8 *iv;
120 struct aead_request *req;
121 struct scatterlist *sg;
122
123 if (x->props.flags & XFRM_STATE_ESN)
124 extralen += sizeof(struct esp_output_extra);
125
126 iv = esp_tmp_iv(aead, tmp, extralen);
127 req = esp_tmp_req(aead, iv);
128
129 /* Unref skb_frag_pages in the src scatterlist if necessary.
130 * Skip the first sg which comes from skb->data.
131 */
132 if (req->src != req->dst)
133 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
134 put_page(sg_page(sg));
135}
136
137#ifdef CONFIG_INET6_ESPINTCP
138struct esp_tcp_sk {
139 struct sock *sk;
140 struct rcu_head rcu;
141};
142
143static void esp_free_tcp_sk(struct rcu_head *head)
144{
145 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
146
147 sock_put(esk->sk);
148 kfree(esk);
149}
150
151static struct sock *esp6_find_tcp_sk(struct xfrm_state *x)
152{
153 struct xfrm_encap_tmpl *encap = x->encap;
154 struct net *net = xs_net(x);
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(net, net->ipv4.tcp_death_row.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->sk, 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 * accommodate 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 int nfrags;
482 int esph_offset;
483 struct page *page;
484 struct sk_buff *trailer;
485 int tailen = esp->tailen;
486
487 if (x->encap) {
488 int err = esp6_output_encap(x, skb, esp);
489
490 if (err < 0)
491 return err;
492 }
493
494 if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE ||
495 ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE)
496 goto cow;
497
498 if (!skb_cloned(skb)) {
499 if (tailen <= skb_tailroom(skb)) {
500 nfrags = 1;
501 trailer = skb;
502 tail = skb_tail_pointer(trailer);
503
504 goto skip_cow;
505 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
506 && !skb_has_frag_list(skb)) {
507 int allocsize;
508 struct sock *sk = skb->sk;
509 struct page_frag *pfrag = &x->xfrag;
510
511 esp->inplace = false;
512
513 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
514
515 spin_lock_bh(&x->lock);
516
517 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
518 spin_unlock_bh(&x->lock);
519 goto cow;
520 }
521
522 page = pfrag->page;
523 get_page(page);
524
525 tail = page_address(page) + pfrag->offset;
526
527 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
528
529 nfrags = skb_shinfo(skb)->nr_frags;
530
531 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
532 tailen);
533 skb_shinfo(skb)->nr_frags = ++nfrags;
534
535 pfrag->offset = pfrag->offset + allocsize;
536
537 spin_unlock_bh(&x->lock);
538
539 nfrags++;
540
541 skb->len += tailen;
542 skb->data_len += tailen;
543 skb->truesize += tailen;
544 if (sk && sk_fullsock(sk))
545 refcount_add(tailen, &sk->sk_wmem_alloc);
546
547 goto out;
548 }
549 }
550
551cow:
552 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
553
554 nfrags = skb_cow_data(skb, tailen, &trailer);
555 if (nfrags < 0)
556 goto out;
557 tail = skb_tail_pointer(trailer);
558 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
559
560skip_cow:
561 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
562 pskb_put(skb, trailer, tailen);
563
564out:
565 return nfrags;
566}
567EXPORT_SYMBOL_GPL(esp6_output_head);
568
569int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
570{
571 u8 *iv;
572 int alen;
573 void *tmp;
574 int ivlen;
575 int assoclen;
576 int extralen;
577 struct page *page;
578 struct ip_esp_hdr *esph;
579 struct aead_request *req;
580 struct crypto_aead *aead;
581 struct scatterlist *sg, *dsg;
582 struct esp_output_extra *extra;
583 int err = -ENOMEM;
584
585 assoclen = sizeof(struct ip_esp_hdr);
586 extralen = 0;
587
588 if (x->props.flags & XFRM_STATE_ESN) {
589 extralen += sizeof(*extra);
590 assoclen += sizeof(__be32);
591 }
592
593 aead = x->data;
594 alen = crypto_aead_authsize(aead);
595 ivlen = crypto_aead_ivsize(aead);
596
597 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
598 if (!tmp)
599 goto error;
600
601 extra = esp_tmp_extra(tmp);
602 iv = esp_tmp_iv(aead, tmp, extralen);
603 req = esp_tmp_req(aead, iv);
604 sg = esp_req_sg(aead, req);
605
606 if (esp->inplace)
607 dsg = sg;
608 else
609 dsg = &sg[esp->nfrags];
610
611 esph = esp_output_set_esn(skb, x, esp->esph, extra);
612 esp->esph = esph;
613
614 sg_init_table(sg, esp->nfrags);
615 err = skb_to_sgvec(skb, sg,
616 (unsigned char *)esph - skb->data,
617 assoclen + ivlen + esp->clen + alen);
618 if (unlikely(err < 0))
619 goto error_free;
620
621 if (!esp->inplace) {
622 int allocsize;
623 struct page_frag *pfrag = &x->xfrag;
624
625 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
626
627 spin_lock_bh(&x->lock);
628 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
629 spin_unlock_bh(&x->lock);
630 goto error_free;
631 }
632
633 skb_shinfo(skb)->nr_frags = 1;
634
635 page = pfrag->page;
636 get_page(page);
637 /* replace page frags in skb with new page */
638 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
639 pfrag->offset = pfrag->offset + allocsize;
640 spin_unlock_bh(&x->lock);
641
642 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
643 err = skb_to_sgvec(skb, dsg,
644 (unsigned char *)esph - skb->data,
645 assoclen + ivlen + esp->clen + alen);
646 if (unlikely(err < 0))
647 goto error_free;
648 }
649
650 if ((x->props.flags & XFRM_STATE_ESN))
651 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
652 else
653 aead_request_set_callback(req, 0, esp_output_done, skb);
654
655 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
656 aead_request_set_ad(req, assoclen);
657
658 memset(iv, 0, ivlen);
659 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
660 min(ivlen, 8));
661
662 ESP_SKB_CB(skb)->tmp = tmp;
663 err = crypto_aead_encrypt(req);
664
665 switch (err) {
666 case -EINPROGRESS:
667 goto error;
668
669 case -ENOSPC:
670 err = NET_XMIT_DROP;
671 break;
672
673 case 0:
674 if ((x->props.flags & XFRM_STATE_ESN))
675 esp_output_restore_header(skb);
676 esp_output_encap_csum(skb);
677 }
678
679 if (sg != dsg)
680 esp_ssg_unref(x, tmp);
681
682 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
683 err = esp_output_tail_tcp(x, skb);
684
685error_free:
686 kfree(tmp);
687error:
688 return err;
689}
690EXPORT_SYMBOL_GPL(esp6_output_tail);
691
692static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
693{
694 int alen;
695 int blksize;
696 struct ip_esp_hdr *esph;
697 struct crypto_aead *aead;
698 struct esp_info esp;
699
700 esp.inplace = true;
701
702 esp.proto = *skb_mac_header(skb);
703 *skb_mac_header(skb) = IPPROTO_ESP;
704
705 /* skb is pure payload to encrypt */
706
707 aead = x->data;
708 alen = crypto_aead_authsize(aead);
709
710 esp.tfclen = 0;
711 if (x->tfcpad) {
712 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
713 u32 padto;
714
715 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
716 if (skb->len < padto)
717 esp.tfclen = padto - skb->len;
718 }
719 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
720 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
721 esp.plen = esp.clen - skb->len - esp.tfclen;
722 esp.tailen = esp.tfclen + esp.plen + alen;
723
724 esp.esph = ip_esp_hdr(skb);
725
726 esp.nfrags = esp6_output_head(x, skb, &esp);
727 if (esp.nfrags < 0)
728 return esp.nfrags;
729
730 esph = esp.esph;
731 esph->spi = x->id.spi;
732
733 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
734 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
735 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
736
737 skb_push(skb, -skb_network_offset(skb));
738
739 return esp6_output_tail(x, skb, &esp);
740}
741
742static inline int esp_remove_trailer(struct sk_buff *skb)
743{
744 struct xfrm_state *x = xfrm_input_state(skb);
745 struct crypto_aead *aead = x->data;
746 int alen, hlen, elen;
747 int padlen, trimlen;
748 __wsum csumdiff;
749 u8 nexthdr[2];
750 int ret;
751
752 alen = crypto_aead_authsize(aead);
753 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
754 elen = skb->len - hlen;
755
756 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
757 BUG_ON(ret);
758
759 ret = -EINVAL;
760 padlen = nexthdr[0];
761 if (padlen + 2 + alen >= elen) {
762 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
763 padlen + 2, elen - alen);
764 goto out;
765 }
766
767 trimlen = alen + padlen + 2;
768 if (skb->ip_summed == CHECKSUM_COMPLETE) {
769 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
770 skb->csum = csum_block_sub(skb->csum, csumdiff,
771 skb->len - trimlen);
772 }
773 pskb_trim(skb, skb->len - trimlen);
774
775 ret = nexthdr[1];
776
777out:
778 return ret;
779}
780
781int esp6_input_done2(struct sk_buff *skb, int err)
782{
783 struct xfrm_state *x = xfrm_input_state(skb);
784 struct xfrm_offload *xo = xfrm_offload(skb);
785 struct crypto_aead *aead = x->data;
786 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
787 int hdr_len = skb_network_header_len(skb);
788
789 if (!xo || !(xo->flags & CRYPTO_DONE))
790 kfree(ESP_SKB_CB(skb)->tmp);
791
792 if (unlikely(err))
793 goto out;
794
795 err = esp_remove_trailer(skb);
796 if (unlikely(err < 0))
797 goto out;
798
799 if (x->encap) {
800 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
801 int offset = skb_network_offset(skb) + sizeof(*ip6h);
802 struct xfrm_encap_tmpl *encap = x->encap;
803 u8 nexthdr = ip6h->nexthdr;
804 __be16 frag_off, source;
805 struct udphdr *uh;
806 struct tcphdr *th;
807
808 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
809 if (offset == -1) {
810 err = -EINVAL;
811 goto out;
812 }
813
814 uh = (void *)(skb->data + offset);
815 th = (void *)(skb->data + offset);
816 hdr_len += offset;
817
818 switch (x->encap->encap_type) {
819 case TCP_ENCAP_ESPINTCP:
820 source = th->source;
821 break;
822 case UDP_ENCAP_ESPINUDP:
823 case UDP_ENCAP_ESPINUDP_NON_IKE:
824 source = uh->source;
825 break;
826 default:
827 WARN_ON_ONCE(1);
828 err = -EINVAL;
829 goto out;
830 }
831
832 /*
833 * 1) if the NAT-T peer's IP or port changed then
834 * advertize the change to the keying daemon.
835 * This is an inbound SA, so just compare
836 * SRC ports.
837 */
838 if (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) ||
839 source != encap->encap_sport) {
840 xfrm_address_t ipaddr;
841
842 memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6));
843 km_new_mapping(x, &ipaddr, source);
844
845 /* XXX: perhaps add an extra
846 * policy check here, to see
847 * if we should allow or
848 * reject a packet from a
849 * different source
850 * address/port.
851 */
852 }
853
854 /*
855 * 2) ignore UDP/TCP checksums in case
856 * of NAT-T in Transport Mode, or
857 * perform other post-processing fixes
858 * as per draft-ietf-ipsec-udp-encaps-06,
859 * section 3.1.2
860 */
861 if (x->props.mode == XFRM_MODE_TRANSPORT)
862 skb->ip_summed = CHECKSUM_UNNECESSARY;
863 }
864
865 skb_postpull_rcsum(skb, skb_network_header(skb),
866 skb_network_header_len(skb));
867 skb_pull_rcsum(skb, hlen);
868 if (x->props.mode == XFRM_MODE_TUNNEL)
869 skb_reset_transport_header(skb);
870 else
871 skb_set_transport_header(skb, -hdr_len);
872
873 /* RFC4303: Drop dummy packets without any error */
874 if (err == IPPROTO_NONE)
875 err = -EINVAL;
876
877out:
878 return err;
879}
880EXPORT_SYMBOL_GPL(esp6_input_done2);
881
882static void esp_input_done(struct crypto_async_request *base, int err)
883{
884 struct sk_buff *skb = base->data;
885
886 xfrm_input_resume(skb, esp6_input_done2(skb, err));
887}
888
889static void esp_input_restore_header(struct sk_buff *skb)
890{
891 esp_restore_header(skb, 0);
892 __skb_pull(skb, 4);
893}
894
895static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
896{
897 struct xfrm_state *x = xfrm_input_state(skb);
898
899 /* For ESN we move the header forward by 4 bytes to
900 * accommodate the high bits. We will move it back after
901 * decryption.
902 */
903 if ((x->props.flags & XFRM_STATE_ESN)) {
904 struct ip_esp_hdr *esph = skb_push(skb, 4);
905
906 *seqhi = esph->spi;
907 esph->spi = esph->seq_no;
908 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
909 }
910}
911
912static void esp_input_done_esn(struct crypto_async_request *base, int err)
913{
914 struct sk_buff *skb = base->data;
915
916 esp_input_restore_header(skb);
917 esp_input_done(base, err);
918}
919
920static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
921{
922 struct crypto_aead *aead = x->data;
923 struct aead_request *req;
924 struct sk_buff *trailer;
925 int ivlen = crypto_aead_ivsize(aead);
926 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
927 int nfrags;
928 int assoclen;
929 int seqhilen;
930 int ret = 0;
931 void *tmp;
932 __be32 *seqhi;
933 u8 *iv;
934 struct scatterlist *sg;
935
936 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
937 ret = -EINVAL;
938 goto out;
939 }
940
941 if (elen <= 0) {
942 ret = -EINVAL;
943 goto out;
944 }
945
946 assoclen = sizeof(struct ip_esp_hdr);
947 seqhilen = 0;
948
949 if (x->props.flags & XFRM_STATE_ESN) {
950 seqhilen += sizeof(__be32);
951 assoclen += seqhilen;
952 }
953
954 if (!skb_cloned(skb)) {
955 if (!skb_is_nonlinear(skb)) {
956 nfrags = 1;
957
958 goto skip_cow;
959 } else if (!skb_has_frag_list(skb)) {
960 nfrags = skb_shinfo(skb)->nr_frags;
961 nfrags++;
962
963 goto skip_cow;
964 }
965 }
966
967 nfrags = skb_cow_data(skb, 0, &trailer);
968 if (nfrags < 0) {
969 ret = -EINVAL;
970 goto out;
971 }
972
973skip_cow:
974 ret = -ENOMEM;
975 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
976 if (!tmp)
977 goto out;
978
979 ESP_SKB_CB(skb)->tmp = tmp;
980 seqhi = esp_tmp_extra(tmp);
981 iv = esp_tmp_iv(aead, tmp, seqhilen);
982 req = esp_tmp_req(aead, iv);
983 sg = esp_req_sg(aead, req);
984
985 esp_input_set_header(skb, seqhi);
986
987 sg_init_table(sg, nfrags);
988 ret = skb_to_sgvec(skb, sg, 0, skb->len);
989 if (unlikely(ret < 0)) {
990 kfree(tmp);
991 goto out;
992 }
993
994 skb->ip_summed = CHECKSUM_NONE;
995
996 if ((x->props.flags & XFRM_STATE_ESN))
997 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
998 else
999 aead_request_set_callback(req, 0, esp_input_done, skb);
1000
1001 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
1002 aead_request_set_ad(req, assoclen);
1003
1004 ret = crypto_aead_decrypt(req);
1005 if (ret == -EINPROGRESS)
1006 goto out;
1007
1008 if ((x->props.flags & XFRM_STATE_ESN))
1009 esp_input_restore_header(skb);
1010
1011 ret = esp6_input_done2(skb, ret);
1012
1013out:
1014 return ret;
1015}
1016
1017static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
1018 u8 type, u8 code, int offset, __be32 info)
1019{
1020 struct net *net = dev_net(skb->dev);
1021 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
1022 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
1023 struct xfrm_state *x;
1024
1025 if (type != ICMPV6_PKT_TOOBIG &&
1026 type != NDISC_REDIRECT)
1027 return 0;
1028
1029 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
1030 esph->spi, IPPROTO_ESP, AF_INET6);
1031 if (!x)
1032 return 0;
1033
1034 if (type == NDISC_REDIRECT)
1035 ip6_redirect(skb, net, skb->dev->ifindex, 0,
1036 sock_net_uid(net, NULL));
1037 else
1038 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
1039 xfrm_state_put(x);
1040
1041 return 0;
1042}
1043
1044static void esp6_destroy(struct xfrm_state *x)
1045{
1046 struct crypto_aead *aead = x->data;
1047
1048 if (!aead)
1049 return;
1050
1051 crypto_free_aead(aead);
1052}
1053
1054static int esp_init_aead(struct xfrm_state *x, struct netlink_ext_ack *extack)
1055{
1056 char aead_name[CRYPTO_MAX_ALG_NAME];
1057 struct crypto_aead *aead;
1058 int err;
1059
1060 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1061 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) {
1062 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1063 return -ENAMETOOLONG;
1064 }
1065
1066 aead = crypto_alloc_aead(aead_name, 0, 0);
1067 err = PTR_ERR(aead);
1068 if (IS_ERR(aead))
1069 goto error;
1070
1071 x->data = aead;
1072
1073 err = crypto_aead_setkey(aead, x->aead->alg_key,
1074 (x->aead->alg_key_len + 7) / 8);
1075 if (err)
1076 goto error;
1077
1078 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
1079 if (err)
1080 goto error;
1081
1082 return 0;
1083
1084error:
1085 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1086 return err;
1087}
1088
1089static int esp_init_authenc(struct xfrm_state *x,
1090 struct netlink_ext_ack *extack)
1091{
1092 struct crypto_aead *aead;
1093 struct crypto_authenc_key_param *param;
1094 struct rtattr *rta;
1095 char *key;
1096 char *p;
1097 char authenc_name[CRYPTO_MAX_ALG_NAME];
1098 unsigned int keylen;
1099 int err;
1100
1101 err = -ENAMETOOLONG;
1102
1103 if ((x->props.flags & XFRM_STATE_ESN)) {
1104 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1105 "%s%sauthencesn(%s,%s)%s",
1106 x->geniv ?: "", x->geniv ? "(" : "",
1107 x->aalg ? x->aalg->alg_name : "digest_null",
1108 x->ealg->alg_name,
1109 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) {
1110 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1111 goto error;
1112 }
1113 } else {
1114 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1115 "%s%sauthenc(%s,%s)%s",
1116 x->geniv ?: "", x->geniv ? "(" : "",
1117 x->aalg ? x->aalg->alg_name : "digest_null",
1118 x->ealg->alg_name,
1119 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) {
1120 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1121 goto error;
1122 }
1123 }
1124
1125 aead = crypto_alloc_aead(authenc_name, 0, 0);
1126 err = PTR_ERR(aead);
1127 if (IS_ERR(aead)) {
1128 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1129 goto error;
1130 }
1131
1132 x->data = aead;
1133
1134 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
1135 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
1136 err = -ENOMEM;
1137 key = kmalloc(keylen, GFP_KERNEL);
1138 if (!key)
1139 goto error;
1140
1141 p = key;
1142 rta = (void *)p;
1143 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1144 rta->rta_len = RTA_LENGTH(sizeof(*param));
1145 param = RTA_DATA(rta);
1146 p += RTA_SPACE(sizeof(*param));
1147
1148 if (x->aalg) {
1149 struct xfrm_algo_desc *aalg_desc;
1150
1151 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1152 p += (x->aalg->alg_key_len + 7) / 8;
1153
1154 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1155 BUG_ON(!aalg_desc);
1156
1157 err = -EINVAL;
1158 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1159 crypto_aead_authsize(aead)) {
1160 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1161 goto free_key;
1162 }
1163
1164 err = crypto_aead_setauthsize(
1165 aead, x->aalg->alg_trunc_len / 8);
1166 if (err) {
1167 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1168 goto free_key;
1169 }
1170 }
1171
1172 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1173 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1174
1175 err = crypto_aead_setkey(aead, key, keylen);
1176
1177free_key:
1178 kfree(key);
1179
1180error:
1181 return err;
1182}
1183
1184static int esp6_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
1185{
1186 struct crypto_aead *aead;
1187 u32 align;
1188 int err;
1189
1190 x->data = NULL;
1191
1192 if (x->aead) {
1193 err = esp_init_aead(x, extack);
1194 } else if (x->ealg) {
1195 err = esp_init_authenc(x, extack);
1196 } else {
1197 NL_SET_ERR_MSG(extack, "ESP: AEAD or CRYPT must be provided");
1198 err = -EINVAL;
1199 }
1200
1201 if (err)
1202 goto error;
1203
1204 aead = x->data;
1205
1206 x->props.header_len = sizeof(struct ip_esp_hdr) +
1207 crypto_aead_ivsize(aead);
1208 switch (x->props.mode) {
1209 case XFRM_MODE_BEET:
1210 if (x->sel.family != AF_INET6)
1211 x->props.header_len += IPV4_BEET_PHMAXLEN +
1212 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
1213 break;
1214 default:
1215 case XFRM_MODE_TRANSPORT:
1216 break;
1217 case XFRM_MODE_TUNNEL:
1218 x->props.header_len += sizeof(struct ipv6hdr);
1219 break;
1220 }
1221
1222 if (x->encap) {
1223 struct xfrm_encap_tmpl *encap = x->encap;
1224
1225 switch (encap->encap_type) {
1226 default:
1227 NL_SET_ERR_MSG(extack, "Unsupported encapsulation type for ESP");
1228 err = -EINVAL;
1229 goto error;
1230 case UDP_ENCAP_ESPINUDP:
1231 x->props.header_len += sizeof(struct udphdr);
1232 break;
1233 case UDP_ENCAP_ESPINUDP_NON_IKE:
1234 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1235 break;
1236#ifdef CONFIG_INET6_ESPINTCP
1237 case TCP_ENCAP_ESPINTCP:
1238 /* only the length field, TCP encap is done by
1239 * the socket
1240 */
1241 x->props.header_len += 2;
1242 break;
1243#endif
1244 }
1245 }
1246
1247 align = ALIGN(crypto_aead_blocksize(aead), 4);
1248 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1249
1250error:
1251 return err;
1252}
1253
1254static int esp6_rcv_cb(struct sk_buff *skb, int err)
1255{
1256 return 0;
1257}
1258
1259static const struct xfrm_type esp6_type = {
1260 .owner = THIS_MODULE,
1261 .proto = IPPROTO_ESP,
1262 .flags = XFRM_TYPE_REPLAY_PROT,
1263 .init_state = esp6_init_state,
1264 .destructor = esp6_destroy,
1265 .input = esp6_input,
1266 .output = esp6_output,
1267};
1268
1269static struct xfrm6_protocol esp6_protocol = {
1270 .handler = xfrm6_rcv,
1271 .input_handler = xfrm_input,
1272 .cb_handler = esp6_rcv_cb,
1273 .err_handler = esp6_err,
1274 .priority = 0,
1275};
1276
1277static int __init esp6_init(void)
1278{
1279 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
1280 pr_info("%s: can't add xfrm type\n", __func__);
1281 return -EAGAIN;
1282 }
1283 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
1284 pr_info("%s: can't add protocol\n", __func__);
1285 xfrm_unregister_type(&esp6_type, AF_INET6);
1286 return -EAGAIN;
1287 }
1288
1289 return 0;
1290}
1291
1292static void __exit esp6_fini(void)
1293{
1294 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
1295 pr_info("%s: can't remove protocol\n", __func__);
1296 xfrm_unregister_type(&esp6_type, AF_INET6);
1297}
1298
1299module_init(esp6_init);
1300module_exit(esp6_fini);
1301
1302MODULE_LICENSE("GPL");
1303MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);