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
49 struct 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
56 static 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 */
esp_alloc_tmp(struct crypto_aead * aead,int nfrags,int seqihlen)67 static 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
esp_tmp_seqhi(void * tmp)89 static inline __be32 *esp_tmp_seqhi(void *tmp)
90 {
91 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
92 }
93
esp_tmp_iv(struct crypto_aead * aead,void * tmp,int seqhilen)94 static 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
esp_tmp_req(struct crypto_aead * aead,u8 * iv)101 static 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
esp_req_sg(struct crypto_aead * aead,struct aead_request * req)111 static 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
esp_ssg_unref(struct xfrm_state * x,void * tmp)119 static 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
esp_output_done(struct crypto_async_request * base,int err)141 static 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. */
esp_restore_header(struct sk_buff * skb,unsigned int offset)173 static 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
esp_output_restore_header(struct sk_buff * skb)183 static void esp_output_restore_header(struct sk_buff *skb)
184 {
185 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
186 }
187
esp_output_set_esn(struct sk_buff * skb,struct xfrm_state * x,struct ip_esp_hdr * esph,__be32 * seqhi)188 static 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
esp_output_done_esn(struct crypto_async_request * base,int err)213 static 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
esp_output_fill_trailer(u8 * tail,int tfclen,int plen,__u8 proto)221 static 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
esp6_output_head(struct xfrm_state * x,struct sk_buff * skb,struct esp_info * esp)237 int 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
303 cow:
304 nfrags = skb_cow_data(skb, tailen, &trailer);
305 if (nfrags < 0)
306 goto out;
307 tail = skb_tail_pointer(trailer);
308
309 skip_cow:
310 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
311 pskb_put(skb, trailer, tailen);
312
313 out:
314 return nfrags;
315 }
316 EXPORT_SYMBOL_GPL(esp6_output_head);
317
esp6_output_tail(struct xfrm_state * x,struct sk_buff * skb,struct esp_info * esp)318 int 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
429 error_free:
430 kfree(tmp);
431 error:
432 return err;
433 }
434 EXPORT_SYMBOL_GPL(esp6_output_tail);
435
esp6_output(struct xfrm_state * x,struct sk_buff * skb)436 static 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
esp_remove_trailer(struct sk_buff * skb)484 static 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
525 out:
526 return ret;
527 }
528
esp6_input_done2(struct sk_buff * skb,int err)529 int 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
559 out:
560 return err;
561 }
562 EXPORT_SYMBOL_GPL(esp6_input_done2);
563
esp_input_done(struct crypto_async_request * base,int err)564 static 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
esp_input_restore_header(struct sk_buff * skb)571 static void esp_input_restore_header(struct sk_buff *skb)
572 {
573 esp_restore_header(skb, 0);
574 __skb_pull(skb, 4);
575 }
576
esp_input_set_header(struct sk_buff * skb,__be32 * seqhi)577 static 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
esp_input_done_esn(struct crypto_async_request * base,int err)594 static 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
esp6_input(struct xfrm_state * x,struct sk_buff * skb)602 static 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
656 skip_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 kfree(tmp);
674 goto out;
675 }
676
677 skb->ip_summed = CHECKSUM_NONE;
678
679 if ((x->props.flags & XFRM_STATE_ESN))
680 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
681 else
682 aead_request_set_callback(req, 0, esp_input_done, skb);
683
684 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
685 aead_request_set_ad(req, assoclen);
686
687 ret = crypto_aead_decrypt(req);
688 if (ret == -EINPROGRESS)
689 goto out;
690
691 if ((x->props.flags & XFRM_STATE_ESN))
692 esp_input_restore_header(skb);
693
694 ret = esp6_input_done2(skb, ret);
695
696 out:
697 return ret;
698 }
699
esp6_get_mtu(struct xfrm_state * x,int mtu)700 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
701 {
702 struct crypto_aead *aead = x->data;
703 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
704 unsigned int net_adj;
705
706 if (x->props.mode != XFRM_MODE_TUNNEL)
707 net_adj = sizeof(struct ipv6hdr);
708 else
709 net_adj = 0;
710
711 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
712 net_adj) & ~(blksize - 1)) + net_adj - 2;
713 }
714
esp6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)715 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
716 u8 type, u8 code, int offset, __be32 info)
717 {
718 struct net *net = dev_net(skb->dev);
719 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
720 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
721 struct xfrm_state *x;
722
723 if (type != ICMPV6_PKT_TOOBIG &&
724 type != NDISC_REDIRECT)
725 return 0;
726
727 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
728 esph->spi, IPPROTO_ESP, AF_INET6);
729 if (!x)
730 return 0;
731
732 if (type == NDISC_REDIRECT)
733 ip6_redirect(skb, net, skb->dev->ifindex, 0,
734 sock_net_uid(net, NULL));
735 else
736 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
737 xfrm_state_put(x);
738
739 return 0;
740 }
741
esp6_destroy(struct xfrm_state * x)742 static void esp6_destroy(struct xfrm_state *x)
743 {
744 struct crypto_aead *aead = x->data;
745
746 if (!aead)
747 return;
748
749 crypto_free_aead(aead);
750 }
751
esp_init_aead(struct xfrm_state * x)752 static int esp_init_aead(struct xfrm_state *x)
753 {
754 char aead_name[CRYPTO_MAX_ALG_NAME];
755 struct crypto_aead *aead;
756 int err;
757
758 err = -ENAMETOOLONG;
759 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
760 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
761 goto error;
762
763 aead = crypto_alloc_aead(aead_name, 0, 0);
764 err = PTR_ERR(aead);
765 if (IS_ERR(aead))
766 goto error;
767
768 x->data = aead;
769
770 err = crypto_aead_setkey(aead, x->aead->alg_key,
771 (x->aead->alg_key_len + 7) / 8);
772 if (err)
773 goto error;
774
775 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
776 if (err)
777 goto error;
778
779 error:
780 return err;
781 }
782
esp_init_authenc(struct xfrm_state * x)783 static int esp_init_authenc(struct xfrm_state *x)
784 {
785 struct crypto_aead *aead;
786 struct crypto_authenc_key_param *param;
787 struct rtattr *rta;
788 char *key;
789 char *p;
790 char authenc_name[CRYPTO_MAX_ALG_NAME];
791 unsigned int keylen;
792 int err;
793
794 err = -EINVAL;
795 if (!x->ealg)
796 goto error;
797
798 err = -ENAMETOOLONG;
799
800 if ((x->props.flags & XFRM_STATE_ESN)) {
801 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
802 "%s%sauthencesn(%s,%s)%s",
803 x->geniv ?: "", x->geniv ? "(" : "",
804 x->aalg ? x->aalg->alg_name : "digest_null",
805 x->ealg->alg_name,
806 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
807 goto error;
808 } else {
809 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
810 "%s%sauthenc(%s,%s)%s",
811 x->geniv ?: "", x->geniv ? "(" : "",
812 x->aalg ? x->aalg->alg_name : "digest_null",
813 x->ealg->alg_name,
814 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
815 goto error;
816 }
817
818 aead = crypto_alloc_aead(authenc_name, 0, 0);
819 err = PTR_ERR(aead);
820 if (IS_ERR(aead))
821 goto error;
822
823 x->data = aead;
824
825 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
826 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
827 err = -ENOMEM;
828 key = kmalloc(keylen, GFP_KERNEL);
829 if (!key)
830 goto error;
831
832 p = key;
833 rta = (void *)p;
834 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
835 rta->rta_len = RTA_LENGTH(sizeof(*param));
836 param = RTA_DATA(rta);
837 p += RTA_SPACE(sizeof(*param));
838
839 if (x->aalg) {
840 struct xfrm_algo_desc *aalg_desc;
841
842 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
843 p += (x->aalg->alg_key_len + 7) / 8;
844
845 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
846 BUG_ON(!aalg_desc);
847
848 err = -EINVAL;
849 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
850 crypto_aead_authsize(aead)) {
851 pr_info("ESP: %s digestsize %u != %hu\n",
852 x->aalg->alg_name,
853 crypto_aead_authsize(aead),
854 aalg_desc->uinfo.auth.icv_fullbits / 8);
855 goto free_key;
856 }
857
858 err = crypto_aead_setauthsize(
859 aead, x->aalg->alg_trunc_len / 8);
860 if (err)
861 goto free_key;
862 }
863
864 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
865 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
866
867 err = crypto_aead_setkey(aead, key, keylen);
868
869 free_key:
870 kfree(key);
871
872 error:
873 return err;
874 }
875
esp6_init_state(struct xfrm_state * x)876 static int esp6_init_state(struct xfrm_state *x)
877 {
878 struct crypto_aead *aead;
879 u32 align;
880 int err;
881
882 if (x->encap)
883 return -EINVAL;
884
885 x->data = NULL;
886
887 if (x->aead)
888 err = esp_init_aead(x);
889 else
890 err = esp_init_authenc(x);
891
892 if (err)
893 goto error;
894
895 aead = x->data;
896
897 x->props.header_len = sizeof(struct ip_esp_hdr) +
898 crypto_aead_ivsize(aead);
899 switch (x->props.mode) {
900 case XFRM_MODE_BEET:
901 if (x->sel.family != AF_INET6)
902 x->props.header_len += IPV4_BEET_PHMAXLEN +
903 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
904 break;
905 default:
906 case XFRM_MODE_TRANSPORT:
907 break;
908 case XFRM_MODE_TUNNEL:
909 x->props.header_len += sizeof(struct ipv6hdr);
910 break;
911 }
912
913 align = ALIGN(crypto_aead_blocksize(aead), 4);
914 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
915
916 error:
917 return err;
918 }
919
esp6_rcv_cb(struct sk_buff * skb,int err)920 static int esp6_rcv_cb(struct sk_buff *skb, int err)
921 {
922 return 0;
923 }
924
925 static const struct xfrm_type esp6_type = {
926 .description = "ESP6",
927 .owner = THIS_MODULE,
928 .proto = IPPROTO_ESP,
929 .flags = XFRM_TYPE_REPLAY_PROT,
930 .init_state = esp6_init_state,
931 .destructor = esp6_destroy,
932 .get_mtu = esp6_get_mtu,
933 .input = esp6_input,
934 .output = esp6_output,
935 .hdr_offset = xfrm6_find_1stfragopt,
936 };
937
938 static struct xfrm6_protocol esp6_protocol = {
939 .handler = xfrm6_rcv,
940 .cb_handler = esp6_rcv_cb,
941 .err_handler = esp6_err,
942 .priority = 0,
943 };
944
esp6_init(void)945 static int __init esp6_init(void)
946 {
947 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
948 pr_info("%s: can't add xfrm type\n", __func__);
949 return -EAGAIN;
950 }
951 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
952 pr_info("%s: can't add protocol\n", __func__);
953 xfrm_unregister_type(&esp6_type, AF_INET6);
954 return -EAGAIN;
955 }
956
957 return 0;
958 }
959
esp6_fini(void)960 static void __exit esp6_fini(void)
961 {
962 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
963 pr_info("%s: can't remove protocol\n", __func__);
964 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
965 pr_info("%s: can't remove xfrm type\n", __func__);
966 }
967
968 module_init(esp6_init);
969 module_exit(esp6_fini);
970
971 MODULE_LICENSE("GPL");
972 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
973
