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Linux 4.8.3
[linux/fpc-iii.git] / net / ipv6 / ah6.c
blob0630a4d5daaabaf9a294c18c398ab569ed74661c
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/ah.c.
24 */
25
26 #define pr_fmt(fmt) "IPv6: " fmt
27
28 #include <crypto/hash.h>
29 #include <linux/module.h>
30 #include <linux/slab.h>
31 #include <net/ip.h>
32 #include <net/ah.h>
33 #include <linux/crypto.h>
34 #include <linux/pfkeyv2.h>
35 #include <linux/string.h>
36 #include <linux/scatterlist.h>
37 #include <net/ip6_route.h>
38 #include <net/icmp.h>
39 #include <net/ipv6.h>
40 #include <net/protocol.h>
41 #include <net/xfrm.h>
42
43 #define IPV6HDR_BASELEN 8
44
45 struct tmp_ext {
46 #if IS_ENABLED(CONFIG_IPV6_MIP6)
47 struct in6_addr saddr;
48 #endif
49 struct in6_addr daddr;
50 char hdrs[0];
51 };
52
53 struct ah_skb_cb {
54 struct xfrm_skb_cb xfrm;
55 void *tmp;
56 };
57
58 #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
59
60 static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
61 unsigned int size)
62 {
63 unsigned int len;
64
65 len = size + crypto_ahash_digestsize(ahash) +
66 (crypto_ahash_alignmask(ahash) &
67 ~(crypto_tfm_ctx_alignment() - 1));
68
69 len = ALIGN(len, crypto_tfm_ctx_alignment());
70
71 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
72 len = ALIGN(len, __alignof__(struct scatterlist));
73
74 len += sizeof(struct scatterlist) * nfrags;
75
76 return kmalloc(len, GFP_ATOMIC);
77 }
78
79 static inline struct tmp_ext *ah_tmp_ext(void *base)
80 {
81 return base + IPV6HDR_BASELEN;
82 }
83
84 static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
85 {
86 return tmp + offset;
87 }
88
89 static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
90 unsigned int offset)
91 {
92 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
93 }
94
95 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
96 u8 *icv)
97 {
98 struct ahash_request *req;
99
100 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
101 crypto_tfm_ctx_alignment());
102
103 ahash_request_set_tfm(req, ahash);
104
105 return req;
106 }
107
108 static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
109 struct ahash_request *req)
110 {
111 return (void *)ALIGN((unsigned long)(req + 1) +
112 crypto_ahash_reqsize(ahash),
113 __alignof__(struct scatterlist));
114 }
115
116 static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
117 {
118 u8 *opt = (u8 *)opthdr;
119 int len = ipv6_optlen(opthdr);
120 int off = 0;
121 int optlen = 0;
122
123 off += 2;
124 len -= 2;
125
126 while (len > 0) {
127
128 switch (opt[off]) {
129
130 case IPV6_TLV_PAD1:
131 optlen = 1;
132 break;
133 default:
134 if (len < 2)
135 goto bad;
136 optlen = opt[off+1]+2;
137 if (len < optlen)
138 goto bad;
139 if (opt[off] & 0x20)
140 memset(&opt[off+2], 0, opt[off+1]);
141 break;
142 }
143
144 off += optlen;
145 len -= optlen;
146 }
147 if (len == 0)
148 return true;
149
150 bad:
151 return false;
152 }
153
154 #if IS_ENABLED(CONFIG_IPV6_MIP6)
155 /**
156 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
157 * @iph: IPv6 header
158 * @destopt: destionation options header
159 */
160 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
161 {
162 u8 *opt = (u8 *)destopt;
163 int len = ipv6_optlen(destopt);
164 int off = 0;
165 int optlen = 0;
166
167 off += 2;
168 len -= 2;
169
170 while (len > 0) {
171
172 switch (opt[off]) {
173
174 case IPV6_TLV_PAD1:
175 optlen = 1;
176 break;
177 default:
178 if (len < 2)
179 goto bad;
180 optlen = opt[off+1]+2;
181 if (len < optlen)
182 goto bad;
183
184 /* Rearrange the source address in @iph and the
185 * addresses in home address option for final source.
186 * See 11.3.2 of RFC 3775 for details.
187 */
188 if (opt[off] == IPV6_TLV_HAO) {
189 struct in6_addr final_addr;
190 struct ipv6_destopt_hao *hao;
191
192 hao = (struct ipv6_destopt_hao *)&opt[off];
193 if (hao->length != sizeof(hao->addr)) {
194 net_warn_ratelimited("destopt hao: invalid header length: %u\n",
195 hao->length);
196 goto bad;
197 }
198 final_addr = hao->addr;
199 hao->addr = iph->saddr;
200 iph->saddr = final_addr;
201 }
202 break;
203 }
204
205 off += optlen;
206 len -= optlen;
207 }
208 /* Note: ok if len == 0 */
209 bad:
210 return;
211 }
212 #else
213 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
214 #endif
215
216 /**
217 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
218 * @iph: IPv6 header
219 * @rthdr: routing header
220 *
221 * Rearrange the destination address in @iph and the addresses in @rthdr
222 * so that they appear in the order they will at the final destination.
223 * See Appendix A2 of RFC 2402 for details.
224 */
225 static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
226 {
227 int segments, segments_left;
228 struct in6_addr *addrs;
229 struct in6_addr final_addr;
230
231 segments_left = rthdr->segments_left;
232 if (segments_left == 0)
233 return;
234 rthdr->segments_left = 0;
235
236 /* The value of rthdr->hdrlen has been verified either by the system
237 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
238 * packets. So we can assume that it is even and that segments is
239 * greater than or equal to segments_left.
240 *
241 * For the same reason we can assume that this option is of type 0.
242 */
243 segments = rthdr->hdrlen >> 1;
244
245 addrs = ((struct rt0_hdr *)rthdr)->addr;
246 final_addr = addrs[segments - 1];
247
248 addrs += segments - segments_left;
249 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
250
251 addrs[0] = iph->daddr;
252 iph->daddr = final_addr;
253 }
254
255 static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
256 {
257 union {
258 struct ipv6hdr *iph;
259 struct ipv6_opt_hdr *opth;
260 struct ipv6_rt_hdr *rth;
261 char *raw;
262 } exthdr = { .iph = iph };
263 char *end = exthdr.raw + len;
264 int nexthdr = iph->nexthdr;
265
266 exthdr.iph++;
267
268 while (exthdr.raw < end) {
269 switch (nexthdr) {
270 case NEXTHDR_DEST:
271 if (dir == XFRM_POLICY_OUT)
272 ipv6_rearrange_destopt(iph, exthdr.opth);
273 case NEXTHDR_HOP:
274 if (!zero_out_mutable_opts(exthdr.opth)) {
275 net_dbg_ratelimited("overrun %sopts\n",
276 nexthdr == NEXTHDR_HOP ?
277 "hop" : "dest");
278 return -EINVAL;
279 }
280 break;
281
282 case NEXTHDR_ROUTING:
283 ipv6_rearrange_rthdr(iph, exthdr.rth);
284 break;
285
286 default:
287 return 0;
288 }
289
290 nexthdr = exthdr.opth->nexthdr;
291 exthdr.raw += ipv6_optlen(exthdr.opth);
292 }
293
294 return 0;
295 }
296
297 static void ah6_output_done(struct crypto_async_request *base, int err)
298 {
299 int extlen;
300 u8 *iph_base;
301 u8 *icv;
302 struct sk_buff *skb = base->data;
303 struct xfrm_state *x = skb_dst(skb)->xfrm;
304 struct ah_data *ahp = x->data;
305 struct ipv6hdr *top_iph = ipv6_hdr(skb);
306 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
307 struct tmp_ext *iph_ext;
308
309 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
310 if (extlen)
311 extlen += sizeof(*iph_ext);
312
313 iph_base = AH_SKB_CB(skb)->tmp;
314 iph_ext = ah_tmp_ext(iph_base);
315 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
316
317 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
318 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
319
320 if (extlen) {
321 #if IS_ENABLED(CONFIG_IPV6_MIP6)
322 memcpy(&top_iph->saddr, iph_ext, extlen);
323 #else
324 memcpy(&top_iph->daddr, iph_ext, extlen);
325 #endif
326 }
327
328 kfree(AH_SKB_CB(skb)->tmp);
329 xfrm_output_resume(skb, err);
330 }
331
332 static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
333 {
334 int err;
335 int nfrags;
336 int extlen;
337 u8 *iph_base;
338 u8 *icv;
339 u8 nexthdr;
340 struct sk_buff *trailer;
341 struct crypto_ahash *ahash;
342 struct ahash_request *req;
343 struct scatterlist *sg;
344 struct ipv6hdr *top_iph;
345 struct ip_auth_hdr *ah;
346 struct ah_data *ahp;
347 struct tmp_ext *iph_ext;
348 int seqhi_len = 0;
349 __be32 *seqhi;
350 int sglists = 0;
351 struct scatterlist *seqhisg;
352
353 ahp = x->data;
354 ahash = ahp->ahash;
355
356 err = skb_cow_data(skb, 0, &trailer);
357 if (err < 0)
358 goto out;
359 nfrags = err;
360
361 skb_push(skb, -skb_network_offset(skb));
362 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
363 if (extlen)
364 extlen += sizeof(*iph_ext);
365
366 if (x->props.flags & XFRM_STATE_ESN) {
367 sglists = 1;
368 seqhi_len = sizeof(*seqhi);
369 }
370 err = -ENOMEM;
371 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN +
372 extlen + seqhi_len);
373 if (!iph_base)
374 goto out;
375
376 iph_ext = ah_tmp_ext(iph_base);
377 seqhi = (__be32 *)((char *)iph_ext + extlen);
378 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
379 req = ah_tmp_req(ahash, icv);
380 sg = ah_req_sg(ahash, req);
381 seqhisg = sg + nfrags;
382
383 ah = ip_auth_hdr(skb);
384 memset(ah->auth_data, 0, ahp->icv_trunc_len);
385
386 top_iph = ipv6_hdr(skb);
387 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
388
389 nexthdr = *skb_mac_header(skb);
390 *skb_mac_header(skb) = IPPROTO_AH;
391
392 /* When there are no extension headers, we only need to save the first
393 * 8 bytes of the base IP header.
394 */
395 memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
396
397 if (extlen) {
398 #if IS_ENABLED(CONFIG_IPV6_MIP6)
399 memcpy(iph_ext, &top_iph->saddr, extlen);
400 #else
401 memcpy(iph_ext, &top_iph->daddr, extlen);
402 #endif
403 err = ipv6_clear_mutable_options(top_iph,
404 extlen - sizeof(*iph_ext) +
405 sizeof(*top_iph),
406 XFRM_POLICY_OUT);
407 if (err)
408 goto out_free;
409 }
410
411 ah->nexthdr = nexthdr;
412
413 top_iph->priority = 0;
414 top_iph->flow_lbl[0] = 0;
415 top_iph->flow_lbl[1] = 0;
416 top_iph->flow_lbl[2] = 0;
417 top_iph->hop_limit = 0;
418
419 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
420
421 ah->reserved = 0;
422 ah->spi = x->id.spi;
423 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
424
425 sg_init_table(sg, nfrags + sglists);
426 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
427
428 if (x->props.flags & XFRM_STATE_ESN) {
429 /* Attach seqhi sg right after packet payload */
430 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
431 sg_set_buf(seqhisg, seqhi, seqhi_len);
432 }
433 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
434 ahash_request_set_callback(req, 0, ah6_output_done, skb);
435
436 AH_SKB_CB(skb)->tmp = iph_base;
437
438 err = crypto_ahash_digest(req);
439 if (err) {
440 if (err == -EINPROGRESS)
441 goto out;
442
443 if (err == -EBUSY)
444 err = NET_XMIT_DROP;
445 goto out_free;
446 }
447
448 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
449 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
450
451 if (extlen) {
452 #if IS_ENABLED(CONFIG_IPV6_MIP6)
453 memcpy(&top_iph->saddr, iph_ext, extlen);
454 #else
455 memcpy(&top_iph->daddr, iph_ext, extlen);
456 #endif
457 }
458
459 out_free:
460 kfree(iph_base);
461 out:
462 return err;
463 }
464
465 static void ah6_input_done(struct crypto_async_request *base, int err)
466 {
467 u8 *auth_data;
468 u8 *icv;
469 u8 *work_iph;
470 struct sk_buff *skb = base->data;
471 struct xfrm_state *x = xfrm_input_state(skb);
472 struct ah_data *ahp = x->data;
473 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
474 int hdr_len = skb_network_header_len(skb);
475 int ah_hlen = (ah->hdrlen + 2) << 2;
476
477 work_iph = AH_SKB_CB(skb)->tmp;
478 auth_data = ah_tmp_auth(work_iph, hdr_len);
479 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
480
481 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
482 if (err)
483 goto out;
484
485 err = ah->nexthdr;
486
487 skb->network_header += ah_hlen;
488 memcpy(skb_network_header(skb), work_iph, hdr_len);
489 __skb_pull(skb, ah_hlen + hdr_len);
490 if (x->props.mode == XFRM_MODE_TUNNEL)
491 skb_reset_transport_header(skb);
492 else
493 skb_set_transport_header(skb, -hdr_len);
494 out:
495 kfree(AH_SKB_CB(skb)->tmp);
496 xfrm_input_resume(skb, err);
497 }
498
499
500
501 static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
502 {
503 /*
504 * Before process AH
505 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
506 * |<-------------->| hdr_len
507 *
508 * To erase AH:
509 * Keeping copy of cleared headers. After AH processing,
510 * Moving the pointer of skb->network_header by using skb_pull as long
511 * as AH header length. Then copy back the copy as long as hdr_len
512 * If destination header following AH exists, copy it into after [Ext2].
513 *
514 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
515 * There is offset of AH before IPv6 header after the process.
516 */
517
518 u8 *auth_data;
519 u8 *icv;
520 u8 *work_iph;
521 struct sk_buff *trailer;
522 struct crypto_ahash *ahash;
523 struct ahash_request *req;
524 struct scatterlist *sg;
525 struct ip_auth_hdr *ah;
526 struct ipv6hdr *ip6h;
527 struct ah_data *ahp;
528 u16 hdr_len;
529 u16 ah_hlen;
530 int nexthdr;
531 int nfrags;
532 int err = -ENOMEM;
533 int seqhi_len = 0;
534 __be32 *seqhi;
535 int sglists = 0;
536 struct scatterlist *seqhisg;
537
538 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
539 goto out;
540
541 /* We are going to _remove_ AH header to keep sockets happy,
542 * so... Later this can change. */
543 if (skb_unclone(skb, GFP_ATOMIC))
544 goto out;
545
546 skb->ip_summed = CHECKSUM_NONE;
547
548 hdr_len = skb_network_header_len(skb);
549 ah = (struct ip_auth_hdr *)skb->data;
550 ahp = x->data;
551 ahash = ahp->ahash;
552
553 nexthdr = ah->nexthdr;
554 ah_hlen = (ah->hdrlen + 2) << 2;
555
556 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
557 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
558 goto out;
559
560 if (!pskb_may_pull(skb, ah_hlen))
561 goto out;
562
563 err = skb_cow_data(skb, 0, &trailer);
564 if (err < 0)
565 goto out;
566 nfrags = err;
567
568 ah = (struct ip_auth_hdr *)skb->data;
569 ip6h = ipv6_hdr(skb);
570
571 skb_push(skb, hdr_len);
572
573 if (x->props.flags & XFRM_STATE_ESN) {
574 sglists = 1;
575 seqhi_len = sizeof(*seqhi);
576 }
577
578 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
579 ahp->icv_trunc_len + seqhi_len);
580 if (!work_iph) {
581 err = -ENOMEM;
582 goto out;
583 }
584
585 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
586 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
587 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
588 req = ah_tmp_req(ahash, icv);
589 sg = ah_req_sg(ahash, req);
590 seqhisg = sg + nfrags;
591
592 memcpy(work_iph, ip6h, hdr_len);
593 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
594 memset(ah->auth_data, 0, ahp->icv_trunc_len);
595
596 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
597 goto out_free;
598
599 ip6h->priority = 0;
600 ip6h->flow_lbl[0] = 0;
601 ip6h->flow_lbl[1] = 0;
602 ip6h->flow_lbl[2] = 0;
603 ip6h->hop_limit = 0;
604
605 sg_init_table(sg, nfrags + sglists);
606 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
607
608 if (x->props.flags & XFRM_STATE_ESN) {
609 /* Attach seqhi sg right after packet payload */
610 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
611 sg_set_buf(seqhisg, seqhi, seqhi_len);
612 }
613
614 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
615 ahash_request_set_callback(req, 0, ah6_input_done, skb);
616
617 AH_SKB_CB(skb)->tmp = work_iph;
618
619 err = crypto_ahash_digest(req);
620 if (err) {
621 if (err == -EINPROGRESS)
622 goto out;
623
624 goto out_free;
625 }
626
627 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
628 if (err)
629 goto out_free;
630
631 skb->network_header += ah_hlen;
632 memcpy(skb_network_header(skb), work_iph, hdr_len);
633 __skb_pull(skb, ah_hlen + hdr_len);
634
635 if (x->props.mode == XFRM_MODE_TUNNEL)
636 skb_reset_transport_header(skb);
637 else
638 skb_set_transport_header(skb, -hdr_len);
639
640 err = nexthdr;
641
642 out_free:
643 kfree(work_iph);
644 out:
645 return err;
646 }
647
648 static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
649 u8 type, u8 code, int offset, __be32 info)
650 {
651 struct net *net = dev_net(skb->dev);
652 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
653 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset);
654 struct xfrm_state *x;
655
656 if (type != ICMPV6_PKT_TOOBIG &&
657 type != NDISC_REDIRECT)
658 return 0;
659
660 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
661 if (!x)
662 return 0;
663
664 if (type == NDISC_REDIRECT)
665 ip6_redirect(skb, net, skb->dev->ifindex, 0);
666 else
667 ip6_update_pmtu(skb, net, info, 0, 0);
668 xfrm_state_put(x);
669
670 return 0;
671 }
672
673 static int ah6_init_state(struct xfrm_state *x)
674 {
675 struct ah_data *ahp = NULL;
676 struct xfrm_algo_desc *aalg_desc;
677 struct crypto_ahash *ahash;
678
679 if (!x->aalg)
680 goto error;
681
682 if (x->encap)
683 goto error;
684
685 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
686 if (!ahp)
687 return -ENOMEM;
688
689 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
690 if (IS_ERR(ahash))
691 goto error;
692
693 ahp->ahash = ahash;
694 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
695 (x->aalg->alg_key_len + 7) / 8))
696 goto error;
697
698 /*
699 * Lookup the algorithm description maintained by xfrm_algo,
700 * verify crypto transform properties, and store information
701 * we need for AH processing. This lookup cannot fail here
702 * after a successful crypto_alloc_hash().
703 */
704 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
705 BUG_ON(!aalg_desc);
706
707 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
708 crypto_ahash_digestsize(ahash)) {
709 pr_info("AH: %s digestsize %u != %hu\n",
710 x->aalg->alg_name, crypto_ahash_digestsize(ahash),
711 aalg_desc->uinfo.auth.icv_fullbits/8);
712 goto error;
713 }
714
715 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
716 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
717
718 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
719 ahp->icv_trunc_len);
720 switch (x->props.mode) {
721 case XFRM_MODE_BEET:
722 case XFRM_MODE_TRANSPORT:
723 break;
724 case XFRM_MODE_TUNNEL:
725 x->props.header_len += sizeof(struct ipv6hdr);
726 break;
727 default:
728 goto error;
729 }
730 x->data = ahp;
731
732 return 0;
733
734 error:
735 if (ahp) {
736 crypto_free_ahash(ahp->ahash);
737 kfree(ahp);
738 }
739 return -EINVAL;
740 }
741
742 static void ah6_destroy(struct xfrm_state *x)
743 {
744 struct ah_data *ahp = x->data;
745
746 if (!ahp)
747 return;
748
749 crypto_free_ahash(ahp->ahash);
750 kfree(ahp);
751 }
752
753 static int ah6_rcv_cb(struct sk_buff *skb, int err)
754 {
755 return 0;
756 }
757
758 static const struct xfrm_type ah6_type = {
759 .description = "AH6",
760 .owner = THIS_MODULE,
761 .proto = IPPROTO_AH,
762 .flags = XFRM_TYPE_REPLAY_PROT,
763 .init_state = ah6_init_state,
764 .destructor = ah6_destroy,
765 .input = ah6_input,
766 .output = ah6_output,
767 .hdr_offset = xfrm6_find_1stfragopt,
768 };
769
770 static struct xfrm6_protocol ah6_protocol = {
771 .handler = xfrm6_rcv,
772 .cb_handler = ah6_rcv_cb,
773 .err_handler = ah6_err,
774 .priority = 0,
775 };
776
777 static int __init ah6_init(void)
778 {
779 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
780 pr_info("%s: can't add xfrm type\n", __func__);
781 return -EAGAIN;
782 }
783
784 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) {
785 pr_info("%s: can't add protocol\n", __func__);
786 xfrm_unregister_type(&ah6_type, AF_INET6);
787 return -EAGAIN;
788 }
789
790 return 0;
791 }
792
793 static void __exit ah6_fini(void)
794 {
795 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0)
796 pr_info("%s: can't remove protocol\n", __func__);
797
798 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
799 pr_info("%s: can't remove xfrm type\n", __func__);
800
801 }
802
803 module_init(ah6_init);
804 module_exit(ah6_fini);
805
806 MODULE_LICENSE("GPL");
807 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);
Linux with added FPC-III support