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Linux 5.4.12
[linux/fpc-iii.git] / net / ipv6 / esp6.c
bloba3b403ba8f8f00124a4eac73e6dab0ad65ea0f64
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
37 struct 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 */
53 static 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
75 static inline __be32 *esp_tmp_seqhi(void *tmp)
76 {
77 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
78 }
79
80 static 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
87 static 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
97 static 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
105 static 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
127 static 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. */
162 static 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
172 static void esp_output_restore_header(struct sk_buff *skb)
173 {
174 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
175 }
176
177 static 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
202 static 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
210 static 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
226 int 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
292 cow:
293 nfrags = skb_cow_data(skb, tailen, &trailer);
294 if (nfrags < 0)
295 goto out;
296 tail = skb_tail_pointer(trailer);
297
298 skip_cow:
299 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
300 pskb_put(skb, trailer, tailen);
301
302 out:
303 return nfrags;
304 }
305 EXPORT_SYMBOL_GPL(esp6_output_head);
306
307 int 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
418 error_free:
419 kfree(tmp);
420 error:
421 return err;
422 }
423 EXPORT_SYMBOL_GPL(esp6_output_tail);
424
425 static 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
473 static 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
514 out:
515 return ret;
516 }
517
518 int 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
548 out:
549 return err;
550 }
551 EXPORT_SYMBOL_GPL(esp6_input_done2);
552
553 static 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
560 static void esp_input_restore_header(struct sk_buff *skb)
561 {
562 esp_restore_header(skb, 0);
563 __skb_pull(skb, 4);
564 }
565
566 static 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
583 static 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
591 static 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
644 skip_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
684 out:
685 return ret;
686 }
687
688 static 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
715 static 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
725 static 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
752 error:
753 return err;
754 }
755
756 static 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
842 free_key:
843 kfree(key);
844
845 error:
846 return err;
847 }
848
849 static 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
889 error:
890 return err;
891 }
892
893 static int esp6_rcv_cb(struct sk_buff *skb, int err)
894 {
895 return 0;
896 }
897
898 static 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
910 static 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
917 static 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
932 static 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
939 module_init(esp6_init);
940 module_exit(esp6_fini);
941
942 MODULE_LICENSE("GPL");
943 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
Linux with added FPC-III support