?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Linux 4.13.16
[linux/fpc-iii.git] / net / ipv6 / ah6.c
blob7802b72196f32efb7a838d47f7e3cc27654cbc6e
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/algapi.h>
29 #include <crypto/hash.h>
30 #include <linux/module.h>
31 #include <linux/slab.h>
32 #include <net/ip.h>
33 #include <net/ah.h>
34 #include <linux/crypto.h>
35 #include <linux/pfkeyv2.h>
36 #include <linux/string.h>
37 #include <linux/scatterlist.h>
38 #include <net/ip6_route.h>
39 #include <net/icmp.h>
40 #include <net/ipv6.h>
41 #include <net/protocol.h>
42 #include <net/xfrm.h>
43
44 #define IPV6HDR_BASELEN 8
45
46 struct tmp_ext {
47 #if IS_ENABLED(CONFIG_IPV6_MIP6)
48 struct in6_addr saddr;
49 #endif
50 struct in6_addr daddr;
51 char hdrs[0];
52 };
53
54 struct ah_skb_cb {
55 struct xfrm_skb_cb xfrm;
56 void *tmp;
57 };
58
59 #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
60
61 static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
62 unsigned int size)
63 {
64 unsigned int len;
65
66 len = size + crypto_ahash_digestsize(ahash) +
67 (crypto_ahash_alignmask(ahash) &
68 ~(crypto_tfm_ctx_alignment() - 1));
69
70 len = ALIGN(len, crypto_tfm_ctx_alignment());
71
72 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
73 len = ALIGN(len, __alignof__(struct scatterlist));
74
75 len += sizeof(struct scatterlist) * nfrags;
76
77 return kmalloc(len, GFP_ATOMIC);
78 }
79
80 static inline struct tmp_ext *ah_tmp_ext(void *base)
81 {
82 return base + IPV6HDR_BASELEN;
83 }
84
85 static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
86 {
87 return tmp + offset;
88 }
89
90 static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
91 unsigned int offset)
92 {
93 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
94 }
95
96 static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
97 u8 *icv)
98 {
99 struct ahash_request *req;
100
101 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
102 crypto_tfm_ctx_alignment());
103
104 ahash_request_set_tfm(req, ahash);
105
106 return req;
107 }
108
109 static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
110 struct ahash_request *req)
111 {
112 return (void *)ALIGN((unsigned long)(req + 1) +
113 crypto_ahash_reqsize(ahash),
114 __alignof__(struct scatterlist));
115 }
116
117 static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
118 {
119 u8 *opt = (u8 *)opthdr;
120 int len = ipv6_optlen(opthdr);
121 int off = 0;
122 int optlen = 0;
123
124 off += 2;
125 len -= 2;
126
127 while (len > 0) {
128
129 switch (opt[off]) {
130
131 case IPV6_TLV_PAD1:
132 optlen = 1;
133 break;
134 default:
135 if (len < 2)
136 goto bad;
137 optlen = opt[off+1]+2;
138 if (len < optlen)
139 goto bad;
140 if (opt[off] & 0x20)
141 memset(&opt[off+2], 0, opt[off+1]);
142 break;
143 }
144
145 off += optlen;
146 len -= optlen;
147 }
148 if (len == 0)
149 return true;
150
151 bad:
152 return false;
153 }
154
155 #if IS_ENABLED(CONFIG_IPV6_MIP6)
156 /**
157 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
158 * @iph: IPv6 header
159 * @destopt: destionation options header
160 */
161 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
162 {
163 u8 *opt = (u8 *)destopt;
164 int len = ipv6_optlen(destopt);
165 int off = 0;
166 int optlen = 0;
167
168 off += 2;
169 len -= 2;
170
171 while (len > 0) {
172
173 switch (opt[off]) {
174
175 case IPV6_TLV_PAD1:
176 optlen = 1;
177 break;
178 default:
179 if (len < 2)
180 goto bad;
181 optlen = opt[off+1]+2;
182 if (len < optlen)
183 goto bad;
184
185 /* Rearrange the source address in @iph and the
186 * addresses in home address option for final source.
187 * See 11.3.2 of RFC 3775 for details.
188 */
189 if (opt[off] == IPV6_TLV_HAO) {
190 struct in6_addr final_addr;
191 struct ipv6_destopt_hao *hao;
192
193 hao = (struct ipv6_destopt_hao *)&opt[off];
194 if (hao->length != sizeof(hao->addr)) {
195 net_warn_ratelimited("destopt hao: invalid header length: %u\n",
196 hao->length);
197 goto bad;
198 }
199 final_addr = hao->addr;
200 hao->addr = iph->saddr;
201 iph->saddr = final_addr;
202 }
203 break;
204 }
205
206 off += optlen;
207 len -= optlen;
208 }
209 /* Note: ok if len == 0 */
210 bad:
211 return;
212 }
213 #else
214 static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
215 #endif
216
217 /**
218 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
219 * @iph: IPv6 header
220 * @rthdr: routing header
221 *
222 * Rearrange the destination address in @iph and the addresses in @rthdr
223 * so that they appear in the order they will at the final destination.
224 * See Appendix A2 of RFC 2402 for details.
225 */
226 static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
227 {
228 int segments, segments_left;
229 struct in6_addr *addrs;
230 struct in6_addr final_addr;
231
232 segments_left = rthdr->segments_left;
233 if (segments_left == 0)
234 return;
235 rthdr->segments_left = 0;
236
237 /* The value of rthdr->hdrlen has been verified either by the system
238 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
239 * packets. So we can assume that it is even and that segments is
240 * greater than or equal to segments_left.
241 *
242 * For the same reason we can assume that this option is of type 0.
243 */
244 segments = rthdr->hdrlen >> 1;
245
246 addrs = ((struct rt0_hdr *)rthdr)->addr;
247 final_addr = addrs[segments - 1];
248
249 addrs += segments - segments_left;
250 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
251
252 addrs[0] = iph->daddr;
253 iph->daddr = final_addr;
254 }
255
256 static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
257 {
258 union {
259 struct ipv6hdr *iph;
260 struct ipv6_opt_hdr *opth;
261 struct ipv6_rt_hdr *rth;
262 char *raw;
263 } exthdr = { .iph = iph };
264 char *end = exthdr.raw + len;
265 int nexthdr = iph->nexthdr;
266
267 exthdr.iph++;
268
269 while (exthdr.raw < end) {
270 switch (nexthdr) {
271 case NEXTHDR_DEST:
272 if (dir == XFRM_POLICY_OUT)
273 ipv6_rearrange_destopt(iph, exthdr.opth);
274 case NEXTHDR_HOP:
275 if (!zero_out_mutable_opts(exthdr.opth)) {
276 net_dbg_ratelimited("overrun %sopts\n",
277 nexthdr == NEXTHDR_HOP ?
278 "hop" : "dest");
279 return -EINVAL;
280 }
281 break;
282
283 case NEXTHDR_ROUTING:
284 ipv6_rearrange_rthdr(iph, exthdr.rth);
285 break;
286
287 default:
288 return 0;
289 }
290
291 nexthdr = exthdr.opth->nexthdr;
292 exthdr.raw += ipv6_optlen(exthdr.opth);
293 }
294
295 return 0;
296 }
297
298 static void ah6_output_done(struct crypto_async_request *base, int err)
299 {
300 int extlen;
301 u8 *iph_base;
302 u8 *icv;
303 struct sk_buff *skb = base->data;
304 struct xfrm_state *x = skb_dst(skb)->xfrm;
305 struct ah_data *ahp = x->data;
306 struct ipv6hdr *top_iph = ipv6_hdr(skb);
307 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
308 struct tmp_ext *iph_ext;
309
310 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
311 if (extlen)
312 extlen += sizeof(*iph_ext);
313
314 iph_base = AH_SKB_CB(skb)->tmp;
315 iph_ext = ah_tmp_ext(iph_base);
316 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
317
318 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
319 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
320
321 if (extlen) {
322 #if IS_ENABLED(CONFIG_IPV6_MIP6)
323 memcpy(&top_iph->saddr, iph_ext, extlen);
324 #else
325 memcpy(&top_iph->daddr, iph_ext, extlen);
326 #endif
327 }
328
329 kfree(AH_SKB_CB(skb)->tmp);
330 xfrm_output_resume(skb, err);
331 }
332
333 static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
334 {
335 int err;
336 int nfrags;
337 int extlen;
338 u8 *iph_base;
339 u8 *icv;
340 u8 nexthdr;
341 struct sk_buff *trailer;
342 struct crypto_ahash *ahash;
343 struct ahash_request *req;
344 struct scatterlist *sg;
345 struct ipv6hdr *top_iph;
346 struct ip_auth_hdr *ah;
347 struct ah_data *ahp;
348 struct tmp_ext *iph_ext;
349 int seqhi_len = 0;
350 __be32 *seqhi;
351 int sglists = 0;
352 struct scatterlist *seqhisg;
353
354 ahp = x->data;
355 ahash = ahp->ahash;
356
357 err = skb_cow_data(skb, 0, &trailer);
358 if (err < 0)
359 goto out;
360 nfrags = err;
361
362 skb_push(skb, -skb_network_offset(skb));
363 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
364 if (extlen)
365 extlen += sizeof(*iph_ext);
366
367 if (x->props.flags & XFRM_STATE_ESN) {
368 sglists = 1;
369 seqhi_len = sizeof(*seqhi);
370 }
371 err = -ENOMEM;
372 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN +
373 extlen + seqhi_len);
374 if (!iph_base)
375 goto out;
376
377 iph_ext = ah_tmp_ext(iph_base);
378 seqhi = (__be32 *)((char *)iph_ext + extlen);
379 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
380 req = ah_tmp_req(ahash, icv);
381 sg = ah_req_sg(ahash, req);
382 seqhisg = sg + nfrags;
383
384 ah = ip_auth_hdr(skb);
385 memset(ah->auth_data, 0, ahp->icv_trunc_len);
386
387 top_iph = ipv6_hdr(skb);
388 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
389
390 nexthdr = *skb_mac_header(skb);
391 *skb_mac_header(skb) = IPPROTO_AH;
392
393 /* When there are no extension headers, we only need to save the first
394 * 8 bytes of the base IP header.
395 */
396 memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
397
398 if (extlen) {
399 #if IS_ENABLED(CONFIG_IPV6_MIP6)
400 memcpy(iph_ext, &top_iph->saddr, extlen);
401 #else
402 memcpy(iph_ext, &top_iph->daddr, extlen);
403 #endif
404 err = ipv6_clear_mutable_options(top_iph,
405 extlen - sizeof(*iph_ext) +
406 sizeof(*top_iph),
407 XFRM_POLICY_OUT);
408 if (err)
409 goto out_free;
410 }
411
412 ah->nexthdr = nexthdr;
413
414 top_iph->priority = 0;
415 top_iph->flow_lbl[0] = 0;
416 top_iph->flow_lbl[1] = 0;
417 top_iph->flow_lbl[2] = 0;
418 top_iph->hop_limit = 0;
419
420 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
421
422 ah->reserved = 0;
423 ah->spi = x->id.spi;
424 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
425
426 sg_init_table(sg, nfrags + sglists);
427 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
428 if (unlikely(err < 0))
429 goto out_free;
430
431 if (x->props.flags & XFRM_STATE_ESN) {
432 /* Attach seqhi sg right after packet payload */
433 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
434 sg_set_buf(seqhisg, seqhi, seqhi_len);
435 }
436 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
437 ahash_request_set_callback(req, 0, ah6_output_done, skb);
438
439 AH_SKB_CB(skb)->tmp = iph_base;
440
441 err = crypto_ahash_digest(req);
442 if (err) {
443 if (err == -EINPROGRESS)
444 goto out;
445
446 if (err == -EBUSY)
447 err = NET_XMIT_DROP;
448 goto out_free;
449 }
450
451 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
452 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
453
454 if (extlen) {
455 #if IS_ENABLED(CONFIG_IPV6_MIP6)
456 memcpy(&top_iph->saddr, iph_ext, extlen);
457 #else
458 memcpy(&top_iph->daddr, iph_ext, extlen);
459 #endif
460 }
461
462 out_free:
463 kfree(iph_base);
464 out:
465 return err;
466 }
467
468 static void ah6_input_done(struct crypto_async_request *base, int err)
469 {
470 u8 *auth_data;
471 u8 *icv;
472 u8 *work_iph;
473 struct sk_buff *skb = base->data;
474 struct xfrm_state *x = xfrm_input_state(skb);
475 struct ah_data *ahp = x->data;
476 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
477 int hdr_len = skb_network_header_len(skb);
478 int ah_hlen = (ah->hdrlen + 2) << 2;
479
480 if (err)
481 goto out;
482
483 work_iph = AH_SKB_CB(skb)->tmp;
484 auth_data = ah_tmp_auth(work_iph, hdr_len);
485 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
486
487 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
488 if (err)
489 goto out;
490
491 err = ah->nexthdr;
492
493 skb->network_header += ah_hlen;
494 memcpy(skb_network_header(skb), work_iph, hdr_len);
495 __skb_pull(skb, ah_hlen + hdr_len);
496 if (x->props.mode == XFRM_MODE_TUNNEL)
497 skb_reset_transport_header(skb);
498 else
499 skb_set_transport_header(skb, -hdr_len);
500 out:
501 kfree(AH_SKB_CB(skb)->tmp);
502 xfrm_input_resume(skb, err);
503 }
504
505
506
507 static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
508 {
509 /*
510 * Before process AH
511 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
512 * |<-------------->| hdr_len
513 *
514 * To erase AH:
515 * Keeping copy of cleared headers. After AH processing,
516 * Moving the pointer of skb->network_header by using skb_pull as long
517 * as AH header length. Then copy back the copy as long as hdr_len
518 * If destination header following AH exists, copy it into after [Ext2].
519 *
520 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
521 * There is offset of AH before IPv6 header after the process.
522 */
523
524 u8 *auth_data;
525 u8 *icv;
526 u8 *work_iph;
527 struct sk_buff *trailer;
528 struct crypto_ahash *ahash;
529 struct ahash_request *req;
530 struct scatterlist *sg;
531 struct ip_auth_hdr *ah;
532 struct ipv6hdr *ip6h;
533 struct ah_data *ahp;
534 u16 hdr_len;
535 u16 ah_hlen;
536 int nexthdr;
537 int nfrags;
538 int err = -ENOMEM;
539 int seqhi_len = 0;
540 __be32 *seqhi;
541 int sglists = 0;
542 struct scatterlist *seqhisg;
543
544 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
545 goto out;
546
547 /* We are going to _remove_ AH header to keep sockets happy,
548 * so... Later this can change. */
549 if (skb_unclone(skb, GFP_ATOMIC))
550 goto out;
551
552 skb->ip_summed = CHECKSUM_NONE;
553
554 hdr_len = skb_network_header_len(skb);
555 ah = (struct ip_auth_hdr *)skb->data;
556 ahp = x->data;
557 ahash = ahp->ahash;
558
559 nexthdr = ah->nexthdr;
560 ah_hlen = (ah->hdrlen + 2) << 2;
561
562 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
563 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
564 goto out;
565
566 if (!pskb_may_pull(skb, ah_hlen))
567 goto out;
568
569 err = skb_cow_data(skb, 0, &trailer);
570 if (err < 0)
571 goto out;
572 nfrags = err;
573
574 ah = (struct ip_auth_hdr *)skb->data;
575 ip6h = ipv6_hdr(skb);
576
577 skb_push(skb, hdr_len);
578
579 if (x->props.flags & XFRM_STATE_ESN) {
580 sglists = 1;
581 seqhi_len = sizeof(*seqhi);
582 }
583
584 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
585 ahp->icv_trunc_len + seqhi_len);
586 if (!work_iph) {
587 err = -ENOMEM;
588 goto out;
589 }
590
591 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
592 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
593 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
594 req = ah_tmp_req(ahash, icv);
595 sg = ah_req_sg(ahash, req);
596 seqhisg = sg + nfrags;
597
598 memcpy(work_iph, ip6h, hdr_len);
599 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
600 memset(ah->auth_data, 0, ahp->icv_trunc_len);
601
602 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
603 goto out_free;
604
605 ip6h->priority = 0;
606 ip6h->flow_lbl[0] = 0;
607 ip6h->flow_lbl[1] = 0;
608 ip6h->flow_lbl[2] = 0;
609 ip6h->hop_limit = 0;
610
611 sg_init_table(sg, nfrags + sglists);
612 err = skb_to_sgvec_nomark(skb, sg, 0, skb->len);
613 if (unlikely(err < 0))
614 goto out_free;
615
616 if (x->props.flags & XFRM_STATE_ESN) {
617 /* Attach seqhi sg right after packet payload */
618 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
619 sg_set_buf(seqhisg, seqhi, seqhi_len);
620 }
621
622 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
623 ahash_request_set_callback(req, 0, ah6_input_done, skb);
624
625 AH_SKB_CB(skb)->tmp = work_iph;
626
627 err = crypto_ahash_digest(req);
628 if (err) {
629 if (err == -EINPROGRESS)
630 goto out;
631
632 goto out_free;
633 }
634
635 err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0;
636 if (err)
637 goto out_free;
638
639 skb->network_header += ah_hlen;
640 memcpy(skb_network_header(skb), work_iph, hdr_len);
641 __skb_pull(skb, ah_hlen + hdr_len);
642
643 if (x->props.mode == XFRM_MODE_TUNNEL)
644 skb_reset_transport_header(skb);
645 else
646 skb_set_transport_header(skb, -hdr_len);
647
648 err = nexthdr;
649
650 out_free:
651 kfree(work_iph);
652 out:
653 return err;
654 }
655
656 static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
657 u8 type, u8 code, int offset, __be32 info)
658 {
659 struct net *net = dev_net(skb->dev);
660 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
661 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset);
662 struct xfrm_state *x;
663
664 if (type != ICMPV6_PKT_TOOBIG &&
665 type != NDISC_REDIRECT)
666 return 0;
667
668 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
669 if (!x)
670 return 0;
671
672 if (type == NDISC_REDIRECT)
673 ip6_redirect(skb, net, skb->dev->ifindex, 0,
674 sock_net_uid(net, NULL));
675 else
676 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
677 xfrm_state_put(x);
678
679 return 0;
680 }
681
682 static int ah6_init_state(struct xfrm_state *x)
683 {
684 struct ah_data *ahp = NULL;
685 struct xfrm_algo_desc *aalg_desc;
686 struct crypto_ahash *ahash;
687
688 if (!x->aalg)
689 goto error;
690
691 if (x->encap)
692 goto error;
693
694 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
695 if (!ahp)
696 return -ENOMEM;
697
698 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
699 if (IS_ERR(ahash))
700 goto error;
701
702 ahp->ahash = ahash;
703 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
704 (x->aalg->alg_key_len + 7) / 8))
705 goto error;
706
707 /*
708 * Lookup the algorithm description maintained by xfrm_algo,
709 * verify crypto transform properties, and store information
710 * we need for AH processing. This lookup cannot fail here
711 * after a successful crypto_alloc_hash().
712 */
713 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
714 BUG_ON(!aalg_desc);
715
716 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
717 crypto_ahash_digestsize(ahash)) {
718 pr_info("AH: %s digestsize %u != %hu\n",
719 x->aalg->alg_name, crypto_ahash_digestsize(ahash),
720 aalg_desc->uinfo.auth.icv_fullbits/8);
721 goto error;
722 }
723
724 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
725 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
726
727 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
728 ahp->icv_trunc_len);
729 switch (x->props.mode) {
730 case XFRM_MODE_BEET:
731 case XFRM_MODE_TRANSPORT:
732 break;
733 case XFRM_MODE_TUNNEL:
734 x->props.header_len += sizeof(struct ipv6hdr);
735 break;
736 default:
737 goto error;
738 }
739 x->data = ahp;
740
741 return 0;
742
743 error:
744 if (ahp) {
745 crypto_free_ahash(ahp->ahash);
746 kfree(ahp);
747 }
748 return -EINVAL;
749 }
750
751 static void ah6_destroy(struct xfrm_state *x)
752 {
753 struct ah_data *ahp = x->data;
754
755 if (!ahp)
756 return;
757
758 crypto_free_ahash(ahp->ahash);
759 kfree(ahp);
760 }
761
762 static int ah6_rcv_cb(struct sk_buff *skb, int err)
763 {
764 return 0;
765 }
766
767 static const struct xfrm_type ah6_type = {
768 .description = "AH6",
769 .owner = THIS_MODULE,
770 .proto = IPPROTO_AH,
771 .flags = XFRM_TYPE_REPLAY_PROT,
772 .init_state = ah6_init_state,
773 .destructor = ah6_destroy,
774 .input = ah6_input,
775 .output = ah6_output,
776 .hdr_offset = xfrm6_find_1stfragopt,
777 };
778
779 static struct xfrm6_protocol ah6_protocol = {
780 .handler = xfrm6_rcv,
781 .cb_handler = ah6_rcv_cb,
782 .err_handler = ah6_err,
783 .priority = 0,
784 };
785
786 static int __init ah6_init(void)
787 {
788 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
789 pr_info("%s: can't add xfrm type\n", __func__);
790 return -EAGAIN;
791 }
792
793 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) {
794 pr_info("%s: can't add protocol\n", __func__);
795 xfrm_unregister_type(&ah6_type, AF_INET6);
796 return -EAGAIN;
797 }
798
799 return 0;
800 }
801
802 static void __exit ah6_fini(void)
803 {
804 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0)
805 pr_info("%s: can't remove protocol\n", __func__);
806
807 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
808 pr_info("%s: can't remove xfrm type\n", __func__);
809
810 }
811
812 module_init(ah6_init);
813 module_exit(ah6_fini);
814
815 MODULE_LICENSE("GPL");
816 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);
Linux with added FPC-III support