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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
47#include <linux/highmem.h>
48
49struct esp_skb_cb {
50 struct xfrm_skb_cb xfrm;
51 void *tmp;
52};
53
54#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
55
56static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
57
58/*
59 * Allocate an AEAD request structure with extra space for SG and IV.
60 *
61 * For alignment considerations the upper 32 bits of the sequence number are
62 * placed at the front, if present. Followed by the IV, the request and finally
63 * the SG list.
64 *
65 * TODO: Use spare space in skb for this where possible.
66 */
67static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
68{
69 unsigned int len;
70
71 len = seqihlen;
72
73 len += crypto_aead_ivsize(aead);
74
75 if (len) {
76 len += crypto_aead_alignmask(aead) &
77 ~(crypto_tfm_ctx_alignment() - 1);
78 len = ALIGN(len, crypto_tfm_ctx_alignment());
79 }
80
81 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
82 len = ALIGN(len, __alignof__(struct scatterlist));
83
84 len += sizeof(struct scatterlist) * nfrags;
85
86 return kmalloc(len, GFP_ATOMIC);
87}
88
89static inline __be32 *esp_tmp_seqhi(void *tmp)
90{
91 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
92}
93
94static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
95{
96 return crypto_aead_ivsize(aead) ?
97 PTR_ALIGN((u8 *)tmp + seqhilen,
98 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
99}
100
101static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
102{
103 struct aead_request *req;
104
105 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
106 crypto_tfm_ctx_alignment());
107 aead_request_set_tfm(req, aead);
108 return req;
109}
110
111static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
112 struct aead_request *req)
113{
114 return (void *)ALIGN((unsigned long)(req + 1) +
115 crypto_aead_reqsize(aead),
116 __alignof__(struct scatterlist));
117}
118
119static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
120{
121 struct crypto_aead *aead = x->data;
122 int seqhilen = 0;
123 u8 *iv;
124 struct aead_request *req;
125 struct scatterlist *sg;
126
127 if (x->props.flags & XFRM_STATE_ESN)
128 seqhilen += sizeof(__be32);
129
130 iv = esp_tmp_iv(aead, tmp, seqhilen);
131 req = esp_tmp_req(aead, iv);
132
133 /* Unref skb_frag_pages in the src scatterlist if necessary.
134 * Skip the first sg which comes from skb->data.
135 */
136 if (req->src != req->dst)
137 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
138 put_page(sg_page(sg));
139}
140
141static void esp_output_done(struct crypto_async_request *base, int err)
142{
143 struct sk_buff *skb = base->data;
144 struct xfrm_offload *xo = xfrm_offload(skb);
145 void *tmp;
146 struct xfrm_state *x;
147
148 if (xo && (xo->flags & XFRM_DEV_RESUME))
149 x = skb->sp->xvec[skb->sp->len - 1];
150 else
151 x = skb_dst(skb)->xfrm;
152
153 tmp = ESP_SKB_CB(skb)->tmp;
154 esp_ssg_unref(x, tmp);
155 kfree(tmp);
156
157 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
158 if (err) {
159 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
160 kfree_skb(skb);
161 return;
162 }
163
164 skb_push(skb, skb->data - skb_mac_header(skb));
165 secpath_reset(skb);
166 xfrm_dev_resume(skb);
167 } else {
168 xfrm_output_resume(skb, err);
169 }
170}
171
172/* Move ESP header back into place. */
173static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
174{
175 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
176 void *tmp = ESP_SKB_CB(skb)->tmp;
177 __be32 *seqhi = esp_tmp_seqhi(tmp);
178
179 esph->seq_no = esph->spi;
180 esph->spi = *seqhi;
181}
182
183static void esp_output_restore_header(struct sk_buff *skb)
184{
185 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
186}
187
188static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
189 struct xfrm_state *x,
190 struct ip_esp_hdr *esph,
191 __be32 *seqhi)
192{
193 /* For ESN we move the header forward by 4 bytes to
194 * accomodate the high bits. We will move it back after
195 * encryption.
196 */
197 if ((x->props.flags & XFRM_STATE_ESN)) {
198 struct xfrm_offload *xo = xfrm_offload(skb);
199
200 esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
201 *seqhi = esph->spi;
202 if (xo)
203 esph->seq_no = htonl(xo->seq.hi);
204 else
205 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
206 }
207
208 esph->spi = x->id.spi;
209
210 return esph;
211}
212
213static void esp_output_done_esn(struct crypto_async_request *base, int err)
214{
215 struct sk_buff *skb = base->data;
216
217 esp_output_restore_header(skb);
218 esp_output_done(base, err);
219}
220
221static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
222{
223 /* Fill padding... */
224 if (tfclen) {
225 memset(tail, 0, tfclen);
226 tail += tfclen;
227 }
228 do {
229 int i;
230 for (i = 0; i < plen - 2; i++)
231 tail[i] = i + 1;
232 } while (0);
233 tail[plen - 2] = plen - 2;
234 tail[plen - 1] = proto;
235}
236
237int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
238{
239 u8 *tail;
240 u8 *vaddr;
241 int nfrags;
242 struct page *page;
243 struct sk_buff *trailer;
244 int tailen = esp->tailen;
245
246 if (!skb_cloned(skb)) {
247 if (tailen <= skb_tailroom(skb)) {
248 nfrags = 1;
249 trailer = skb;
250 tail = skb_tail_pointer(trailer);
251
252 goto skip_cow;
253 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
254 && !skb_has_frag_list(skb)) {
255 int allocsize;
256 struct sock *sk = skb->sk;
257 struct page_frag *pfrag = &x->xfrag;
258
259 esp->inplace = false;
260
261 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
262
263 spin_lock_bh(&x->lock);
264
265 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
266 spin_unlock_bh(&x->lock);
267 goto cow;
268 }
269
270 page = pfrag->page;
271 get_page(page);
272
273 vaddr = kmap_atomic(page);
274
275 tail = vaddr + pfrag->offset;
276
277 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
278
279 kunmap_atomic(vaddr);
280
281 nfrags = skb_shinfo(skb)->nr_frags;
282
283 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
284 tailen);
285 skb_shinfo(skb)->nr_frags = ++nfrags;
286
287 pfrag->offset = pfrag->offset + allocsize;
288
289 spin_unlock_bh(&x->lock);
290
291 nfrags++;
292
293 skb->len += tailen;
294 skb->data_len += tailen;
295 skb->truesize += tailen;
296 if (sk)
297 refcount_add(tailen, &sk->sk_wmem_alloc);
298
299 goto out;
300 }
301 }
302
303cow:
304 nfrags = skb_cow_data(skb, tailen, &trailer);
305 if (nfrags < 0)
306 goto out;
307 tail = skb_tail_pointer(trailer);
308
309skip_cow:
310 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
311 pskb_put(skb, trailer, tailen);
312
313out:
314 return nfrags;
315}
316EXPORT_SYMBOL_GPL(esp6_output_head);
317
318int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
319{
320 u8 *iv;
321 int alen;
322 void *tmp;
323 int ivlen;
324 int assoclen;
325 int seqhilen;
326 __be32 *seqhi;
327 struct page *page;
328 struct ip_esp_hdr *esph;
329 struct aead_request *req;
330 struct crypto_aead *aead;
331 struct scatterlist *sg, *dsg;
332 int err = -ENOMEM;
333
334 assoclen = sizeof(struct ip_esp_hdr);
335 seqhilen = 0;
336
337 if (x->props.flags & XFRM_STATE_ESN) {
338 seqhilen += sizeof(__be32);
339 assoclen += sizeof(__be32);
340 }
341
342 aead = x->data;
343 alen = crypto_aead_authsize(aead);
344 ivlen = crypto_aead_ivsize(aead);
345
346 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
347 if (!tmp)
348 goto error;
349
350 seqhi = esp_tmp_seqhi(tmp);
351 iv = esp_tmp_iv(aead, tmp, seqhilen);
352 req = esp_tmp_req(aead, iv);
353 sg = esp_req_sg(aead, req);
354
355 if (esp->inplace)
356 dsg = sg;
357 else
358 dsg = &sg[esp->nfrags];
359
360 esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
361
362 sg_init_table(sg, esp->nfrags);
363 err = skb_to_sgvec(skb, sg,
364 (unsigned char *)esph - skb->data,
365 assoclen + ivlen + esp->clen + alen);
366 if (unlikely(err < 0))
367 goto error_free;
368
369 if (!esp->inplace) {
370 int allocsize;
371 struct page_frag *pfrag = &x->xfrag;
372
373 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
374
375 spin_lock_bh(&x->lock);
376 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
377 spin_unlock_bh(&x->lock);
378 goto error_free;
379 }
380
381 skb_shinfo(skb)->nr_frags = 1;
382
383 page = pfrag->page;
384 get_page(page);
385 /* replace page frags in skb with new page */
386 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
387 pfrag->offset = pfrag->offset + allocsize;
388 spin_unlock_bh(&x->lock);
389
390 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
391 err = skb_to_sgvec(skb, dsg,
392 (unsigned char *)esph - skb->data,
393 assoclen + ivlen + esp->clen + alen);
394 if (unlikely(err < 0))
395 goto error_free;
396 }
397
398 if ((x->props.flags & XFRM_STATE_ESN))
399 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
400 else
401 aead_request_set_callback(req, 0, esp_output_done, skb);
402
403 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
404 aead_request_set_ad(req, assoclen);
405
406 memset(iv, 0, ivlen);
407 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
408 min(ivlen, 8));
409
410 ESP_SKB_CB(skb)->tmp = tmp;
411 err = crypto_aead_encrypt(req);
412
413 switch (err) {
414 case -EINPROGRESS:
415 goto error;
416
417 case -ENOSPC:
418 err = NET_XMIT_DROP;
419 break;
420
421 case 0:
422 if ((x->props.flags & XFRM_STATE_ESN))
423 esp_output_restore_header(skb);
424 }
425
426 if (sg != dsg)
427 esp_ssg_unref(x, tmp);
428
429error_free:
430 kfree(tmp);
431error:
432 return err;
433}
434EXPORT_SYMBOL_GPL(esp6_output_tail);
435
436static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
437{
438 int alen;
439 int blksize;
440 struct ip_esp_hdr *esph;
441 struct crypto_aead *aead;
442 struct esp_info esp;
443
444 esp.inplace = true;
445
446 esp.proto = *skb_mac_header(skb);
447 *skb_mac_header(skb) = IPPROTO_ESP;
448
449 /* skb is pure payload to encrypt */
450
451 aead = x->data;
452 alen = crypto_aead_authsize(aead);
453
454 esp.tfclen = 0;
455 if (x->tfcpad) {
456 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
457 u32 padto;
458
459 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
460 if (skb->len < padto)
461 esp.tfclen = padto - skb->len;
462 }
463 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
464 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
465 esp.plen = esp.clen - skb->len - esp.tfclen;
466 esp.tailen = esp.tfclen + esp.plen + alen;
467
468 esp.nfrags = esp6_output_head(x, skb, &esp);
469 if (esp.nfrags < 0)
470 return esp.nfrags;
471
472 esph = ip_esp_hdr(skb);
473 esph->spi = x->id.spi;
474
475 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
476 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
477 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
478
479 skb_push(skb, -skb_network_offset(skb));
480
481 return esp6_output_tail(x, skb, &esp);
482}
483
484static inline int esp_remove_trailer(struct sk_buff *skb)
485{
486 struct xfrm_state *x = xfrm_input_state(skb);
487 struct xfrm_offload *xo = xfrm_offload(skb);
488 struct crypto_aead *aead = x->data;
489 int alen, hlen, elen;
490 int padlen, trimlen;
491 __wsum csumdiff;
492 u8 nexthdr[2];
493 int ret;
494
495 alen = crypto_aead_authsize(aead);
496 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
497 elen = skb->len - hlen;
498
499 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
500 ret = xo->proto;
501 goto out;
502 }
503
504 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
505 BUG_ON(ret);
506
507 ret = -EINVAL;
508 padlen = nexthdr[0];
509 if (padlen + 2 + alen >= elen) {
510 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
511 padlen + 2, elen - alen);
512 goto out;
513 }
514
515 trimlen = alen + padlen + 2;
516 if (skb->ip_summed == CHECKSUM_COMPLETE) {
517 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
518 skb->csum = csum_block_sub(skb->csum, csumdiff,
519 skb->len - trimlen);
520 }
521 pskb_trim(skb, skb->len - trimlen);
522
523 ret = nexthdr[1];
524
525out:
526 return ret;
527}
528
529int esp6_input_done2(struct sk_buff *skb, int err)
530{
531 struct xfrm_state *x = xfrm_input_state(skb);
532 struct xfrm_offload *xo = xfrm_offload(skb);
533 struct crypto_aead *aead = x->data;
534 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
535 int hdr_len = skb_network_header_len(skb);
536
537 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
538 kfree(ESP_SKB_CB(skb)->tmp);
539
540 if (unlikely(err))
541 goto out;
542
543 err = esp_remove_trailer(skb);
544 if (unlikely(err < 0))
545 goto out;
546
547 skb_postpull_rcsum(skb, skb_network_header(skb),
548 skb_network_header_len(skb));
549 skb_pull_rcsum(skb, hlen);
550 if (x->props.mode == XFRM_MODE_TUNNEL)
551 skb_reset_transport_header(skb);
552 else
553 skb_set_transport_header(skb, -hdr_len);
554
555 /* RFC4303: Drop dummy packets without any error */
556 if (err == IPPROTO_NONE)
557 err = -EINVAL;
558
559out:
560 return err;
561}
562EXPORT_SYMBOL_GPL(esp6_input_done2);
563
564static void esp_input_done(struct crypto_async_request *base, int err)
565{
566 struct sk_buff *skb = base->data;
567
568 xfrm_input_resume(skb, esp6_input_done2(skb, err));
569}
570
571static void esp_input_restore_header(struct sk_buff *skb)
572{
573 esp_restore_header(skb, 0);
574 __skb_pull(skb, 4);
575}
576
577static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
578{
579 struct xfrm_state *x = xfrm_input_state(skb);
580
581 /* For ESN we move the header forward by 4 bytes to
582 * accomodate the high bits. We will move it back after
583 * decryption.
584 */
585 if ((x->props.flags & XFRM_STATE_ESN)) {
586 struct ip_esp_hdr *esph = skb_push(skb, 4);
587
588 *seqhi = esph->spi;
589 esph->spi = esph->seq_no;
590 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
591 }
592}
593
594static void esp_input_done_esn(struct crypto_async_request *base, int err)
595{
596 struct sk_buff *skb = base->data;
597
598 esp_input_restore_header(skb);
599 esp_input_done(base, err);
600}
601
602static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
603{
604 struct ip_esp_hdr *esph;
605 struct crypto_aead *aead = x->data;
606 struct aead_request *req;
607 struct sk_buff *trailer;
608 int ivlen = crypto_aead_ivsize(aead);
609 int elen = skb->len - sizeof(*esph) - ivlen;
610 int nfrags;
611 int assoclen;
612 int seqhilen;
613 int ret = 0;
614 void *tmp;
615 __be32 *seqhi;
616 u8 *iv;
617 struct scatterlist *sg;
618
619 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
620 ret = -EINVAL;
621 goto out;
622 }
623
624 if (elen <= 0) {
625 ret = -EINVAL;
626 goto out;
627 }
628
629 assoclen = sizeof(*esph);
630 seqhilen = 0;
631
632 if (x->props.flags & XFRM_STATE_ESN) {
633 seqhilen += sizeof(__be32);
634 assoclen += seqhilen;
635 }
636
637 if (!skb_cloned(skb)) {
638 if (!skb_is_nonlinear(skb)) {
639 nfrags = 1;
640
641 goto skip_cow;
642 } else if (!skb_has_frag_list(skb)) {
643 nfrags = skb_shinfo(skb)->nr_frags;
644 nfrags++;
645
646 goto skip_cow;
647 }
648 }
649
650 nfrags = skb_cow_data(skb, 0, &trailer);
651 if (nfrags < 0) {
652 ret = -EINVAL;
653 goto out;
654 }
655
656skip_cow:
657 ret = -ENOMEM;
658 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
659 if (!tmp)
660 goto out;
661
662 ESP_SKB_CB(skb)->tmp = tmp;
663 seqhi = esp_tmp_seqhi(tmp);
664 iv = esp_tmp_iv(aead, tmp, seqhilen);
665 req = esp_tmp_req(aead, iv);
666 sg = esp_req_sg(aead, req);
667
668 esp_input_set_header(skb, seqhi);
669
670 sg_init_table(sg, nfrags);
671 ret = skb_to_sgvec(skb, sg, 0, skb->len);
672 if (unlikely(ret < 0))
673 goto out;
674
675 skb->ip_summed = CHECKSUM_NONE;
676
677 if ((x->props.flags & XFRM_STATE_ESN))
678 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
679 else
680 aead_request_set_callback(req, 0, esp_input_done, skb);
681
682 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
683 aead_request_set_ad(req, assoclen);
684
685 ret = crypto_aead_decrypt(req);
686 if (ret == -EINPROGRESS)
687 goto out;
688
689 if ((x->props.flags & XFRM_STATE_ESN))
690 esp_input_restore_header(skb);
691
692 ret = esp6_input_done2(skb, ret);
693
694out:
695 return ret;
696}
697
698static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
699{
700 struct crypto_aead *aead = x->data;
701 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
702 unsigned int net_adj;
703
704 if (x->props.mode != XFRM_MODE_TUNNEL)
705 net_adj = sizeof(struct ipv6hdr);
706 else
707 net_adj = 0;
708
709 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
710 net_adj) & ~(blksize - 1)) + net_adj - 2;
711}
712
713static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
714 u8 type, u8 code, int offset, __be32 info)
715{
716 struct net *net = dev_net(skb->dev);
717 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
718 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
719 struct xfrm_state *x;
720
721 if (type != ICMPV6_PKT_TOOBIG &&
722 type != NDISC_REDIRECT)
723 return 0;
724
725 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
726 esph->spi, IPPROTO_ESP, AF_INET6);
727 if (!x)
728 return 0;
729
730 if (type == NDISC_REDIRECT)
731 ip6_redirect(skb, net, skb->dev->ifindex, 0,
732 sock_net_uid(net, NULL));
733 else
734 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
735 xfrm_state_put(x);
736
737 return 0;
738}
739
740static void esp6_destroy(struct xfrm_state *x)
741{
742 struct crypto_aead *aead = x->data;
743
744 if (!aead)
745 return;
746
747 crypto_free_aead(aead);
748}
749
750static int esp_init_aead(struct xfrm_state *x)
751{
752 char aead_name[CRYPTO_MAX_ALG_NAME];
753 struct crypto_aead *aead;
754 int err;
755
756 err = -ENAMETOOLONG;
757 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
758 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
759 goto error;
760
761 aead = crypto_alloc_aead(aead_name, 0, 0);
762 err = PTR_ERR(aead);
763 if (IS_ERR(aead))
764 goto error;
765
766 x->data = aead;
767
768 err = crypto_aead_setkey(aead, x->aead->alg_key,
769 (x->aead->alg_key_len + 7) / 8);
770 if (err)
771 goto error;
772
773 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
774 if (err)
775 goto error;
776
777error:
778 return err;
779}
780
781static int esp_init_authenc(struct xfrm_state *x)
782{
783 struct crypto_aead *aead;
784 struct crypto_authenc_key_param *param;
785 struct rtattr *rta;
786 char *key;
787 char *p;
788 char authenc_name[CRYPTO_MAX_ALG_NAME];
789 unsigned int keylen;
790 int err;
791
792 err = -EINVAL;
793 if (!x->ealg)
794 goto error;
795
796 err = -ENAMETOOLONG;
797
798 if ((x->props.flags & XFRM_STATE_ESN)) {
799 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
800 "%s%sauthencesn(%s,%s)%s",
801 x->geniv ?: "", x->geniv ? "(" : "",
802 x->aalg ? x->aalg->alg_name : "digest_null",
803 x->ealg->alg_name,
804 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
805 goto error;
806 } else {
807 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
808 "%s%sauthenc(%s,%s)%s",
809 x->geniv ?: "", x->geniv ? "(" : "",
810 x->aalg ? x->aalg->alg_name : "digest_null",
811 x->ealg->alg_name,
812 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
813 goto error;
814 }
815
816 aead = crypto_alloc_aead(authenc_name, 0, 0);
817 err = PTR_ERR(aead);
818 if (IS_ERR(aead))
819 goto error;
820
821 x->data = aead;
822
823 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
824 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
825 err = -ENOMEM;
826 key = kmalloc(keylen, GFP_KERNEL);
827 if (!key)
828 goto error;
829
830 p = key;
831 rta = (void *)p;
832 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
833 rta->rta_len = RTA_LENGTH(sizeof(*param));
834 param = RTA_DATA(rta);
835 p += RTA_SPACE(sizeof(*param));
836
837 if (x->aalg) {
838 struct xfrm_algo_desc *aalg_desc;
839
840 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
841 p += (x->aalg->alg_key_len + 7) / 8;
842
843 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
844 BUG_ON(!aalg_desc);
845
846 err = -EINVAL;
847 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
848 crypto_aead_authsize(aead)) {
849 pr_info("ESP: %s digestsize %u != %hu\n",
850 x->aalg->alg_name,
851 crypto_aead_authsize(aead),
852 aalg_desc->uinfo.auth.icv_fullbits / 8);
853 goto free_key;
854 }
855
856 err = crypto_aead_setauthsize(
857 aead, x->aalg->alg_trunc_len / 8);
858 if (err)
859 goto free_key;
860 }
861
862 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
863 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
864
865 err = crypto_aead_setkey(aead, key, keylen);
866
867free_key:
868 kfree(key);
869
870error:
871 return err;
872}
873
874static int esp6_init_state(struct xfrm_state *x)
875{
876 struct crypto_aead *aead;
877 u32 align;
878 int err;
879
880 if (x->encap)
881 return -EINVAL;
882
883 x->data = NULL;
884
885 if (x->aead)
886 err = esp_init_aead(x);
887 else
888 err = esp_init_authenc(x);
889
890 if (err)
891 goto error;
892
893 aead = x->data;
894
895 x->props.header_len = sizeof(struct ip_esp_hdr) +
896 crypto_aead_ivsize(aead);
897 switch (x->props.mode) {
898 case XFRM_MODE_BEET:
899 if (x->sel.family != AF_INET6)
900 x->props.header_len += IPV4_BEET_PHMAXLEN +
901 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
902 break;
903 default:
904 case XFRM_MODE_TRANSPORT:
905 break;
906 case XFRM_MODE_TUNNEL:
907 x->props.header_len += sizeof(struct ipv6hdr);
908 break;
909 }
910
911 align = ALIGN(crypto_aead_blocksize(aead), 4);
912 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
913
914error:
915 return err;
916}
917
918static int esp6_rcv_cb(struct sk_buff *skb, int err)
919{
920 return 0;
921}
922
923static const struct xfrm_type esp6_type = {
924 .description = "ESP6",
925 .owner = THIS_MODULE,
926 .proto = IPPROTO_ESP,
927 .flags = XFRM_TYPE_REPLAY_PROT,
928 .init_state = esp6_init_state,
929 .destructor = esp6_destroy,
930 .get_mtu = esp6_get_mtu,
931 .input = esp6_input,
932 .output = esp6_output,
933 .hdr_offset = xfrm6_find_1stfragopt,
934};
935
936static struct xfrm6_protocol esp6_protocol = {
937 .handler = xfrm6_rcv,
938 .cb_handler = esp6_rcv_cb,
939 .err_handler = esp6_err,
940 .priority = 0,
941};
942
943static int __init esp6_init(void)
944{
945 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
946 pr_info("%s: can't add xfrm type\n", __func__);
947 return -EAGAIN;
948 }
949 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
950 pr_info("%s: can't add protocol\n", __func__);
951 xfrm_unregister_type(&esp6_type, AF_INET6);
952 return -EAGAIN;
953 }
954
955 return 0;
956}
957
958static void __exit esp6_fini(void)
959{
960 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
961 pr_info("%s: can't remove protocol\n", __func__);
962 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
963 pr_info("%s: can't remove xfrm type\n", __func__);
964}
965
966module_init(esp6_init);
967module_exit(esp6_fini);
968
969MODULE_LICENSE("GPL");
970MODULE_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);