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Merge tag 'mips_fixes_5.2_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips...
[linux-2.6/linux-2.6-arm.git] / net / ipv6 / esp6.c
blobae6a739c5f52873d0535998323a04d0f7b3c26c8
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 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
45
46 /*
47 * Allocate an AEAD request structure with extra space for SG and IV.
48 *
49 * For alignment considerations the upper 32 bits of the sequence number are
50 * placed at the front, if present. Followed by the IV, the request and finally
51 * the SG list.
52 *
53 * TODO: Use spare space in skb for this where possible.
54 */
55 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
56 {
57 unsigned int len;
58
59 len = seqihlen;
60
61 len += crypto_aead_ivsize(aead);
62
63 if (len) {
64 len += crypto_aead_alignmask(aead) &
65 ~(crypto_tfm_ctx_alignment() - 1);
66 len = ALIGN(len, crypto_tfm_ctx_alignment());
67 }
68
69 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
70 len = ALIGN(len, __alignof__(struct scatterlist));
71
72 len += sizeof(struct scatterlist) * nfrags;
73
74 return kmalloc(len, GFP_ATOMIC);
75 }
76
77 static inline __be32 *esp_tmp_seqhi(void *tmp)
78 {
79 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
80 }
81
82 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
83 {
84 return crypto_aead_ivsize(aead) ?
85 PTR_ALIGN((u8 *)tmp + seqhilen,
86 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
87 }
88
89 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
90 {
91 struct aead_request *req;
92
93 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
94 crypto_tfm_ctx_alignment());
95 aead_request_set_tfm(req, aead);
96 return req;
97 }
98
99 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
100 struct aead_request *req)
101 {
102 return (void *)ALIGN((unsigned long)(req + 1) +
103 crypto_aead_reqsize(aead),
104 __alignof__(struct scatterlist));
105 }
106
107 static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
108 {
109 struct crypto_aead *aead = x->data;
110 int seqhilen = 0;
111 u8 *iv;
112 struct aead_request *req;
113 struct scatterlist *sg;
114
115 if (x->props.flags & XFRM_STATE_ESN)
116 seqhilen += sizeof(__be32);
117
118 iv = esp_tmp_iv(aead, tmp, seqhilen);
119 req = esp_tmp_req(aead, iv);
120
121 /* Unref skb_frag_pages in the src scatterlist if necessary.
122 * Skip the first sg which comes from skb->data.
123 */
124 if (req->src != req->dst)
125 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
126 put_page(sg_page(sg));
127 }
128
129 static void esp_output_done(struct crypto_async_request *base, int err)
130 {
131 struct sk_buff *skb = base->data;
132 struct xfrm_offload *xo = xfrm_offload(skb);
133 void *tmp;
134 struct xfrm_state *x;
135
136 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
137 struct sec_path *sp = skb_sec_path(skb);
138
139 x = sp->xvec[sp->len - 1];
140 } else {
141 x = skb_dst(skb)->xfrm;
142 }
143
144 tmp = ESP_SKB_CB(skb)->tmp;
145 esp_ssg_unref(x, tmp);
146 kfree(tmp);
147
148 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
149 if (err) {
150 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
151 kfree_skb(skb);
152 return;
153 }
154
155 skb_push(skb, skb->data - skb_mac_header(skb));
156 secpath_reset(skb);
157 xfrm_dev_resume(skb);
158 } else {
159 xfrm_output_resume(skb, err);
160 }
161 }
162
163 /* Move ESP header back into place. */
164 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
165 {
166 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
167 void *tmp = ESP_SKB_CB(skb)->tmp;
168 __be32 *seqhi = esp_tmp_seqhi(tmp);
169
170 esph->seq_no = esph->spi;
171 esph->spi = *seqhi;
172 }
173
174 static void esp_output_restore_header(struct sk_buff *skb)
175 {
176 esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
177 }
178
179 static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
180 struct xfrm_state *x,
181 struct ip_esp_hdr *esph,
182 __be32 *seqhi)
183 {
184 /* For ESN we move the header forward by 4 bytes to
185 * accomodate the high bits. We will move it back after
186 * encryption.
187 */
188 if ((x->props.flags & XFRM_STATE_ESN)) {
189 struct xfrm_offload *xo = xfrm_offload(skb);
190
191 esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
192 *seqhi = esph->spi;
193 if (xo)
194 esph->seq_no = htonl(xo->seq.hi);
195 else
196 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
197 }
198
199 esph->spi = x->id.spi;
200
201 return esph;
202 }
203
204 static void esp_output_done_esn(struct crypto_async_request *base, int err)
205 {
206 struct sk_buff *skb = base->data;
207
208 esp_output_restore_header(skb);
209 esp_output_done(base, err);
210 }
211
212 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
213 {
214 /* Fill padding... */
215 if (tfclen) {
216 memset(tail, 0, tfclen);
217 tail += tfclen;
218 }
219 do {
220 int i;
221 for (i = 0; i < plen - 2; i++)
222 tail[i] = i + 1;
223 } while (0);
224 tail[plen - 2] = plen - 2;
225 tail[plen - 1] = proto;
226 }
227
228 int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
229 {
230 u8 *tail;
231 u8 *vaddr;
232 int nfrags;
233 struct page *page;
234 struct sk_buff *trailer;
235 int tailen = esp->tailen;
236
237 if (!skb_cloned(skb)) {
238 if (tailen <= skb_tailroom(skb)) {
239 nfrags = 1;
240 trailer = skb;
241 tail = skb_tail_pointer(trailer);
242
243 goto skip_cow;
244 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
245 && !skb_has_frag_list(skb)) {
246 int allocsize;
247 struct sock *sk = skb->sk;
248 struct page_frag *pfrag = &x->xfrag;
249
250 esp->inplace = false;
251
252 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
253
254 spin_lock_bh(&x->lock);
255
256 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
257 spin_unlock_bh(&x->lock);
258 goto cow;
259 }
260
261 page = pfrag->page;
262 get_page(page);
263
264 vaddr = kmap_atomic(page);
265
266 tail = vaddr + pfrag->offset;
267
268 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
269
270 kunmap_atomic(vaddr);
271
272 nfrags = skb_shinfo(skb)->nr_frags;
273
274 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
275 tailen);
276 skb_shinfo(skb)->nr_frags = ++nfrags;
277
278 pfrag->offset = pfrag->offset + allocsize;
279
280 spin_unlock_bh(&x->lock);
281
282 nfrags++;
283
284 skb->len += tailen;
285 skb->data_len += tailen;
286 skb->truesize += tailen;
287 if (sk && sk_fullsock(sk))
288 refcount_add(tailen, &sk->sk_wmem_alloc);
289
290 goto out;
291 }
292 }
293
294 cow:
295 nfrags = skb_cow_data(skb, tailen, &trailer);
296 if (nfrags < 0)
297 goto out;
298 tail = skb_tail_pointer(trailer);
299
300 skip_cow:
301 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
302 pskb_put(skb, trailer, tailen);
303
304 out:
305 return nfrags;
306 }
307 EXPORT_SYMBOL_GPL(esp6_output_head);
308
309 int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
310 {
311 u8 *iv;
312 int alen;
313 void *tmp;
314 int ivlen;
315 int assoclen;
316 int seqhilen;
317 __be32 *seqhi;
318 struct page *page;
319 struct ip_esp_hdr *esph;
320 struct aead_request *req;
321 struct crypto_aead *aead;
322 struct scatterlist *sg, *dsg;
323 int err = -ENOMEM;
324
325 assoclen = sizeof(struct ip_esp_hdr);
326 seqhilen = 0;
327
328 if (x->props.flags & XFRM_STATE_ESN) {
329 seqhilen += sizeof(__be32);
330 assoclen += sizeof(__be32);
331 }
332
333 aead = x->data;
334 alen = crypto_aead_authsize(aead);
335 ivlen = crypto_aead_ivsize(aead);
336
337 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
338 if (!tmp)
339 goto error;
340
341 seqhi = esp_tmp_seqhi(tmp);
342 iv = esp_tmp_iv(aead, tmp, seqhilen);
343 req = esp_tmp_req(aead, iv);
344 sg = esp_req_sg(aead, req);
345
346 if (esp->inplace)
347 dsg = sg;
348 else
349 dsg = &sg[esp->nfrags];
350
351 esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
352
353 sg_init_table(sg, esp->nfrags);
354 err = skb_to_sgvec(skb, sg,
355 (unsigned char *)esph - skb->data,
356 assoclen + ivlen + esp->clen + alen);
357 if (unlikely(err < 0))
358 goto error_free;
359
360 if (!esp->inplace) {
361 int allocsize;
362 struct page_frag *pfrag = &x->xfrag;
363
364 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
365
366 spin_lock_bh(&x->lock);
367 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
368 spin_unlock_bh(&x->lock);
369 goto error_free;
370 }
371
372 skb_shinfo(skb)->nr_frags = 1;
373
374 page = pfrag->page;
375 get_page(page);
376 /* replace page frags in skb with new page */
377 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
378 pfrag->offset = pfrag->offset + allocsize;
379 spin_unlock_bh(&x->lock);
380
381 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
382 err = skb_to_sgvec(skb, dsg,
383 (unsigned char *)esph - skb->data,
384 assoclen + ivlen + esp->clen + alen);
385 if (unlikely(err < 0))
386 goto error_free;
387 }
388
389 if ((x->props.flags & XFRM_STATE_ESN))
390 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
391 else
392 aead_request_set_callback(req, 0, esp_output_done, skb);
393
394 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
395 aead_request_set_ad(req, assoclen);
396
397 memset(iv, 0, ivlen);
398 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
399 min(ivlen, 8));
400
401 ESP_SKB_CB(skb)->tmp = tmp;
402 err = crypto_aead_encrypt(req);
403
404 switch (err) {
405 case -EINPROGRESS:
406 goto error;
407
408 case -ENOSPC:
409 err = NET_XMIT_DROP;
410 break;
411
412 case 0:
413 if ((x->props.flags & XFRM_STATE_ESN))
414 esp_output_restore_header(skb);
415 }
416
417 if (sg != dsg)
418 esp_ssg_unref(x, tmp);
419
420 error_free:
421 kfree(tmp);
422 error:
423 return err;
424 }
425 EXPORT_SYMBOL_GPL(esp6_output_tail);
426
427 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
428 {
429 int alen;
430 int blksize;
431 struct ip_esp_hdr *esph;
432 struct crypto_aead *aead;
433 struct esp_info esp;
434
435 esp.inplace = true;
436
437 esp.proto = *skb_mac_header(skb);
438 *skb_mac_header(skb) = IPPROTO_ESP;
439
440 /* skb is pure payload to encrypt */
441
442 aead = x->data;
443 alen = crypto_aead_authsize(aead);
444
445 esp.tfclen = 0;
446 if (x->tfcpad) {
447 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
448 u32 padto;
449
450 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
451 if (skb->len < padto)
452 esp.tfclen = padto - skb->len;
453 }
454 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
455 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
456 esp.plen = esp.clen - skb->len - esp.tfclen;
457 esp.tailen = esp.tfclen + esp.plen + alen;
458
459 esp.nfrags = esp6_output_head(x, skb, &esp);
460 if (esp.nfrags < 0)
461 return esp.nfrags;
462
463 esph = ip_esp_hdr(skb);
464 esph->spi = x->id.spi;
465
466 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
467 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
468 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
469
470 skb_push(skb, -skb_network_offset(skb));
471
472 return esp6_output_tail(x, skb, &esp);
473 }
474
475 static inline int esp_remove_trailer(struct sk_buff *skb)
476 {
477 struct xfrm_state *x = xfrm_input_state(skb);
478 struct xfrm_offload *xo = xfrm_offload(skb);
479 struct crypto_aead *aead = x->data;
480 int alen, hlen, elen;
481 int padlen, trimlen;
482 __wsum csumdiff;
483 u8 nexthdr[2];
484 int ret;
485
486 alen = crypto_aead_authsize(aead);
487 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
488 elen = skb->len - hlen;
489
490 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
491 ret = xo->proto;
492 goto out;
493 }
494
495 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
496 BUG_ON(ret);
497
498 ret = -EINVAL;
499 padlen = nexthdr[0];
500 if (padlen + 2 + alen >= elen) {
501 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
502 padlen + 2, elen - alen);
503 goto out;
504 }
505
506 trimlen = alen + padlen + 2;
507 if (skb->ip_summed == CHECKSUM_COMPLETE) {
508 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
509 skb->csum = csum_block_sub(skb->csum, csumdiff,
510 skb->len - trimlen);
511 }
512 pskb_trim(skb, skb->len - trimlen);
513
514 ret = nexthdr[1];
515
516 out:
517 return ret;
518 }
519
520 int esp6_input_done2(struct sk_buff *skb, int err)
521 {
522 struct xfrm_state *x = xfrm_input_state(skb);
523 struct xfrm_offload *xo = xfrm_offload(skb);
524 struct crypto_aead *aead = x->data;
525 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
526 int hdr_len = skb_network_header_len(skb);
527
528 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
529 kfree(ESP_SKB_CB(skb)->tmp);
530
531 if (unlikely(err))
532 goto out;
533
534 err = esp_remove_trailer(skb);
535 if (unlikely(err < 0))
536 goto out;
537
538 skb_postpull_rcsum(skb, skb_network_header(skb),
539 skb_network_header_len(skb));
540 skb_pull_rcsum(skb, hlen);
541 if (x->props.mode == XFRM_MODE_TUNNEL)
542 skb_reset_transport_header(skb);
543 else
544 skb_set_transport_header(skb, -hdr_len);
545
546 /* RFC4303: Drop dummy packets without any error */
547 if (err == IPPROTO_NONE)
548 err = -EINVAL;
549
550 out:
551 return err;
552 }
553 EXPORT_SYMBOL_GPL(esp6_input_done2);
554
555 static void esp_input_done(struct crypto_async_request *base, int err)
556 {
557 struct sk_buff *skb = base->data;
558
559 xfrm_input_resume(skb, esp6_input_done2(skb, err));
560 }
561
562 static void esp_input_restore_header(struct sk_buff *skb)
563 {
564 esp_restore_header(skb, 0);
565 __skb_pull(skb, 4);
566 }
567
568 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
569 {
570 struct xfrm_state *x = xfrm_input_state(skb);
571
572 /* For ESN we move the header forward by 4 bytes to
573 * accomodate the high bits. We will move it back after
574 * decryption.
575 */
576 if ((x->props.flags & XFRM_STATE_ESN)) {
577 struct ip_esp_hdr *esph = skb_push(skb, 4);
578
579 *seqhi = esph->spi;
580 esph->spi = esph->seq_no;
581 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
582 }
583 }
584
585 static void esp_input_done_esn(struct crypto_async_request *base, int err)
586 {
587 struct sk_buff *skb = base->data;
588
589 esp_input_restore_header(skb);
590 esp_input_done(base, err);
591 }
592
593 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
594 {
595 struct crypto_aead *aead = x->data;
596 struct aead_request *req;
597 struct sk_buff *trailer;
598 int ivlen = crypto_aead_ivsize(aead);
599 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
600 int nfrags;
601 int assoclen;
602 int seqhilen;
603 int ret = 0;
604 void *tmp;
605 __be32 *seqhi;
606 u8 *iv;
607 struct scatterlist *sg;
608
609 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
610 ret = -EINVAL;
611 goto out;
612 }
613
614 if (elen <= 0) {
615 ret = -EINVAL;
616 goto out;
617 }
618
619 assoclen = sizeof(struct ip_esp_hdr);
620 seqhilen = 0;
621
622 if (x->props.flags & XFRM_STATE_ESN) {
623 seqhilen += sizeof(__be32);
624 assoclen += seqhilen;
625 }
626
627 if (!skb_cloned(skb)) {
628 if (!skb_is_nonlinear(skb)) {
629 nfrags = 1;
630
631 goto skip_cow;
632 } else if (!skb_has_frag_list(skb)) {
633 nfrags = skb_shinfo(skb)->nr_frags;
634 nfrags++;
635
636 goto skip_cow;
637 }
638 }
639
640 nfrags = skb_cow_data(skb, 0, &trailer);
641 if (nfrags < 0) {
642 ret = -EINVAL;
643 goto out;
644 }
645
646 skip_cow:
647 ret = -ENOMEM;
648 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
649 if (!tmp)
650 goto out;
651
652 ESP_SKB_CB(skb)->tmp = tmp;
653 seqhi = esp_tmp_seqhi(tmp);
654 iv = esp_tmp_iv(aead, tmp, seqhilen);
655 req = esp_tmp_req(aead, iv);
656 sg = esp_req_sg(aead, req);
657
658 esp_input_set_header(skb, seqhi);
659
660 sg_init_table(sg, nfrags);
661 ret = skb_to_sgvec(skb, sg, 0, skb->len);
662 if (unlikely(ret < 0)) {
663 kfree(tmp);
664 goto out;
665 }
666
667 skb->ip_summed = CHECKSUM_NONE;
668
669 if ((x->props.flags & XFRM_STATE_ESN))
670 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
671 else
672 aead_request_set_callback(req, 0, esp_input_done, skb);
673
674 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
675 aead_request_set_ad(req, assoclen);
676
677 ret = crypto_aead_decrypt(req);
678 if (ret == -EINPROGRESS)
679 goto out;
680
681 if ((x->props.flags & XFRM_STATE_ESN))
682 esp_input_restore_header(skb);
683
684 ret = esp6_input_done2(skb, ret);
685
686 out:
687 return ret;
688 }
689
690 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
691 {
692 struct crypto_aead *aead = x->data;
693 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
694 unsigned int net_adj;
695
696 if (x->props.mode != XFRM_MODE_TUNNEL)
697 net_adj = sizeof(struct ipv6hdr);
698 else
699 net_adj = 0;
700
701 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
702 net_adj) & ~(blksize - 1)) + net_adj - 2;
703 }
704
705 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
706 u8 type, u8 code, int offset, __be32 info)
707 {
708 struct net *net = dev_net(skb->dev);
709 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
710 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
711 struct xfrm_state *x;
712
713 if (type != ICMPV6_PKT_TOOBIG &&
714 type != NDISC_REDIRECT)
715 return 0;
716
717 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
718 esph->spi, IPPROTO_ESP, AF_INET6);
719 if (!x)
720 return 0;
721
722 if (type == NDISC_REDIRECT)
723 ip6_redirect(skb, net, skb->dev->ifindex, 0,
724 sock_net_uid(net, NULL));
725 else
726 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
727 xfrm_state_put(x);
728
729 return 0;
730 }
731
732 static void esp6_destroy(struct xfrm_state *x)
733 {
734 struct crypto_aead *aead = x->data;
735
736 if (!aead)
737 return;
738
739 crypto_free_aead(aead);
740 }
741
742 static int esp_init_aead(struct xfrm_state *x)
743 {
744 char aead_name[CRYPTO_MAX_ALG_NAME];
745 struct crypto_aead *aead;
746 int err;
747
748 err = -ENAMETOOLONG;
749 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
750 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
751 goto error;
752
753 aead = crypto_alloc_aead(aead_name, 0, 0);
754 err = PTR_ERR(aead);
755 if (IS_ERR(aead))
756 goto error;
757
758 x->data = aead;
759
760 err = crypto_aead_setkey(aead, x->aead->alg_key,
761 (x->aead->alg_key_len + 7) / 8);
762 if (err)
763 goto error;
764
765 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
766 if (err)
767 goto error;
768
769 error:
770 return err;
771 }
772
773 static int esp_init_authenc(struct xfrm_state *x)
774 {
775 struct crypto_aead *aead;
776 struct crypto_authenc_key_param *param;
777 struct rtattr *rta;
778 char *key;
779 char *p;
780 char authenc_name[CRYPTO_MAX_ALG_NAME];
781 unsigned int keylen;
782 int err;
783
784 err = -EINVAL;
785 if (!x->ealg)
786 goto error;
787
788 err = -ENAMETOOLONG;
789
790 if ((x->props.flags & XFRM_STATE_ESN)) {
791 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
792 "%s%sauthencesn(%s,%s)%s",
793 x->geniv ?: "", x->geniv ? "(" : "",
794 x->aalg ? x->aalg->alg_name : "digest_null",
795 x->ealg->alg_name,
796 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
797 goto error;
798 } else {
799 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
800 "%s%sauthenc(%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 }
807
808 aead = crypto_alloc_aead(authenc_name, 0, 0);
809 err = PTR_ERR(aead);
810 if (IS_ERR(aead))
811 goto error;
812
813 x->data = aead;
814
815 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
816 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
817 err = -ENOMEM;
818 key = kmalloc(keylen, GFP_KERNEL);
819 if (!key)
820 goto error;
821
822 p = key;
823 rta = (void *)p;
824 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
825 rta->rta_len = RTA_LENGTH(sizeof(*param));
826 param = RTA_DATA(rta);
827 p += RTA_SPACE(sizeof(*param));
828
829 if (x->aalg) {
830 struct xfrm_algo_desc *aalg_desc;
831
832 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
833 p += (x->aalg->alg_key_len + 7) / 8;
834
835 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
836 BUG_ON(!aalg_desc);
837
838 err = -EINVAL;
839 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
840 crypto_aead_authsize(aead)) {
841 pr_info("ESP: %s digestsize %u != %hu\n",
842 x->aalg->alg_name,
843 crypto_aead_authsize(aead),
844 aalg_desc->uinfo.auth.icv_fullbits / 8);
845 goto free_key;
846 }
847
848 err = crypto_aead_setauthsize(
849 aead, x->aalg->alg_trunc_len / 8);
850 if (err)
851 goto free_key;
852 }
853
854 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
855 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
856
857 err = crypto_aead_setkey(aead, key, keylen);
858
859 free_key:
860 kfree(key);
861
862 error:
863 return err;
864 }
865
866 static int esp6_init_state(struct xfrm_state *x)
867 {
868 struct crypto_aead *aead;
869 u32 align;
870 int err;
871
872 if (x->encap)
873 return -EINVAL;
874
875 x->data = NULL;
876
877 if (x->aead)
878 err = esp_init_aead(x);
879 else
880 err = esp_init_authenc(x);
881
882 if (err)
883 goto error;
884
885 aead = x->data;
886
887 x->props.header_len = sizeof(struct ip_esp_hdr) +
888 crypto_aead_ivsize(aead);
889 switch (x->props.mode) {
890 case XFRM_MODE_BEET:
891 if (x->sel.family != AF_INET6)
892 x->props.header_len += IPV4_BEET_PHMAXLEN +
893 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
894 break;
895 default:
896 case XFRM_MODE_TRANSPORT:
897 break;
898 case XFRM_MODE_TUNNEL:
899 x->props.header_len += sizeof(struct ipv6hdr);
900 break;
901 }
902
903 align = ALIGN(crypto_aead_blocksize(aead), 4);
904 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
905
906 error:
907 return err;
908 }
909
910 static int esp6_rcv_cb(struct sk_buff *skb, int err)
911 {
912 return 0;
913 }
914
915 static const struct xfrm_type esp6_type = {
916 .description = "ESP6",
917 .owner = THIS_MODULE,
918 .proto = IPPROTO_ESP,
919 .flags = XFRM_TYPE_REPLAY_PROT,
920 .init_state = esp6_init_state,
921 .destructor = esp6_destroy,
922 .get_mtu = esp6_get_mtu,
923 .input = esp6_input,
924 .output = esp6_output,
925 .hdr_offset = xfrm6_find_1stfragopt,
926 };
927
928 static struct xfrm6_protocol esp6_protocol = {
929 .handler = xfrm6_rcv,
930 .cb_handler = esp6_rcv_cb,
931 .err_handler = esp6_err,
932 .priority = 0,
933 };
934
935 static int __init esp6_init(void)
936 {
937 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
938 pr_info("%s: can't add xfrm type\n", __func__);
939 return -EAGAIN;
940 }
941 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
942 pr_info("%s: can't add protocol\n", __func__);
943 xfrm_unregister_type(&esp6_type, AF_INET6);
944 return -EAGAIN;
945 }
946
947 return 0;
948 }
949
950 static void __exit esp6_fini(void)
951 {
952 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
953 pr_info("%s: can't remove protocol\n", __func__);
954 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
955 pr_info("%s: can't remove xfrm type\n", __func__);
956 }
957
958 module_init(esp6_init);
959 module_exit(esp6_fini);
960
961 MODULE_LICENSE("GPL");
962 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
Mirror of linux-2.6-arm at arm.linux.org.uk