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/ah.c.
12 */
13
14#define pr_fmt(fmt) "IPv6: " fmt
15
16#include <crypto/hash.h>
17#include <crypto/utils.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20#include <net/ip.h>
21#include <net/ah.h>
22#include <linux/crypto.h>
23#include <linux/pfkeyv2.h>
24#include <linux/string.h>
25#include <linux/scatterlist.h>
26#include <net/ip6_route.h>
27#include <net/icmp.h>
28#include <net/ipv6.h>
29#include <net/protocol.h>
30#include <net/xfrm.h>
31
32#define IPV6HDR_BASELEN 8
33
34struct tmp_ext {
35#if IS_ENABLED(CONFIG_IPV6_MIP6)
36 struct in6_addr saddr;
37#endif
38 struct in6_addr daddr;
39 char hdrs[];
40};
41
42struct ah_skb_cb {
43 struct xfrm_skb_cb xfrm;
44 void *tmp;
45};
46
47#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
48
49/* Helper to save IPv6 addresses and extension headers to temporary storage */
50static inline void ah6_save_hdrs(struct tmp_ext *iph_ext,
51 struct ipv6hdr *top_iph, int extlen)
52{
53 if (!extlen)
54 return;
55
56#if IS_ENABLED(CONFIG_IPV6_MIP6)
57 iph_ext->saddr = top_iph->saddr;
58#endif
59 iph_ext->daddr = top_iph->daddr;
60 memcpy(to: &iph_ext->hdrs, from: top_iph + 1, len: extlen - sizeof(*iph_ext));
61}
62
63/* Helper to restore IPv6 addresses and extension headers from temporary storage */
64static inline void ah6_restore_hdrs(struct ipv6hdr *top_iph,
65 struct tmp_ext *iph_ext, int extlen)
66{
67 if (!extlen)
68 return;
69
70#if IS_ENABLED(CONFIG_IPV6_MIP6)
71 top_iph->saddr = iph_ext->saddr;
72#endif
73 top_iph->daddr = iph_ext->daddr;
74 memcpy(to: top_iph + 1, from: &iph_ext->hdrs, len: extlen - sizeof(*iph_ext));
75}
76
77static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
78 unsigned int size)
79{
80 unsigned int len;
81
82 len = size + crypto_ahash_digestsize(tfm: ahash);
83
84 len = ALIGN(len, crypto_tfm_ctx_alignment());
85
86 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(tfm: ahash);
87 len = ALIGN(len, __alignof__(struct scatterlist));
88
89 len += sizeof(struct scatterlist) * nfrags;
90
91 return kmalloc(len, GFP_ATOMIC);
92}
93
94static inline struct tmp_ext *ah_tmp_ext(void *base)
95{
96 return base + IPV6HDR_BASELEN;
97}
98
99static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
100{
101 return tmp + offset;
102}
103
104static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset)
105{
106 return tmp + offset;
107}
108
109static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
110 u8 *icv)
111{
112 struct ahash_request *req;
113
114 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
115 crypto_tfm_ctx_alignment());
116
117 ahash_request_set_tfm(req, tfm: ahash);
118
119 return req;
120}
121
122static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
123 struct ahash_request *req)
124{
125 return (void *)ALIGN((unsigned long)(req + 1) +
126 crypto_ahash_reqsize(ahash),
127 __alignof__(struct scatterlist));
128}
129
130static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
131{
132 u8 *opt = (u8 *)opthdr;
133 int len = ipv6_optlen(opthdr);
134 int off = 0;
135 int optlen = 0;
136
137 off += 2;
138 len -= 2;
139
140 while (len > 0) {
141
142 switch (opt[off]) {
143
144 case IPV6_TLV_PAD1:
145 optlen = 1;
146 break;
147 default:
148 if (len < 2)
149 goto bad;
150 optlen = opt[off+1]+2;
151 if (len < optlen)
152 goto bad;
153 if (opt[off] & 0x20)
154 memset(s: &opt[off+2], c: 0, n: opt[off+1]);
155 break;
156 }
157
158 off += optlen;
159 len -= optlen;
160 }
161 if (len == 0)
162 return true;
163
164bad:
165 return false;
166}
167
168#if IS_ENABLED(CONFIG_IPV6_MIP6)
169/**
170 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
171 * @iph: IPv6 header
172 * @destopt: destionation options header
173 */
174static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
175{
176 u8 *opt = (u8 *)destopt;
177 int len = ipv6_optlen(destopt);
178 int off = 0;
179 int optlen = 0;
180
181 off += 2;
182 len -= 2;
183
184 while (len > 0) {
185
186 switch (opt[off]) {
187
188 case IPV6_TLV_PAD1:
189 optlen = 1;
190 break;
191 default:
192 if (len < 2)
193 goto bad;
194 optlen = opt[off+1]+2;
195 if (len < optlen)
196 goto bad;
197
198 /* Rearrange the source address in @iph and the
199 * addresses in home address option for final source.
200 * See 11.3.2 of RFC 3775 for details.
201 */
202 if (opt[off] == IPV6_TLV_HAO) {
203 struct ipv6_destopt_hao *hao;
204
205 hao = (struct ipv6_destopt_hao *)&opt[off];
206 if (hao->length != sizeof(hao->addr)) {
207 net_warn_ratelimited("destopt hao: invalid header length: %u\n",
208 hao->length);
209 goto bad;
210 }
211 swap(hao->addr, iph->saddr);
212 }
213 break;
214 }
215
216 off += optlen;
217 len -= optlen;
218 }
219 /* Note: ok if len == 0 */
220bad:
221 return;
222}
223#else
224static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
225#endif
226
227/**
228 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
229 * @iph: IPv6 header
230 * @rthdr: routing header
231 *
232 * Rearrange the destination address in @iph and the addresses in @rthdr
233 * so that they appear in the order they will at the final destination.
234 * See Appendix A2 of RFC 2402 for details.
235 */
236static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
237{
238 int segments, segments_left;
239 struct in6_addr *addrs;
240 struct in6_addr final_addr;
241
242 segments_left = rthdr->segments_left;
243 if (segments_left == 0)
244 return;
245 rthdr->segments_left = 0;
246
247 /* The value of rthdr->hdrlen has been verified either by the system
248 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
249 * packets. So we can assume that it is even and that segments is
250 * greater than or equal to segments_left.
251 *
252 * For the same reason we can assume that this option is of type 0.
253 */
254 segments = rthdr->hdrlen >> 1;
255
256 addrs = ((struct rt0_hdr *)rthdr)->addr;
257 final_addr = addrs[segments - 1];
258
259 addrs += segments - segments_left;
260 memmove(dest: addrs + 1, src: addrs, count: (segments_left - 1) * sizeof(*addrs));
261
262 addrs[0] = iph->daddr;
263 iph->daddr = final_addr;
264}
265
266static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
267{
268 union {
269 struct ipv6hdr *iph;
270 struct ipv6_opt_hdr *opth;
271 struct ipv6_rt_hdr *rth;
272 char *raw;
273 } exthdr = { .iph = iph };
274 char *end = exthdr.raw + len;
275 int nexthdr = iph->nexthdr;
276
277 exthdr.iph++;
278
279 while (exthdr.raw < end) {
280 switch (nexthdr) {
281 case NEXTHDR_DEST:
282 if (dir == XFRM_POLICY_OUT)
283 ipv6_rearrange_destopt(iph, destopt: exthdr.opth);
284 fallthrough;
285 case NEXTHDR_HOP:
286 if (!zero_out_mutable_opts(opthdr: exthdr.opth)) {
287 net_dbg_ratelimited("overrun %sopts\n",
288 nexthdr == NEXTHDR_HOP ?
289 "hop" : "dest");
290 return -EINVAL;
291 }
292 break;
293
294 case NEXTHDR_ROUTING:
295 ipv6_rearrange_rthdr(iph, rthdr: exthdr.rth);
296 break;
297
298 default:
299 return 0;
300 }
301
302 nexthdr = exthdr.opth->nexthdr;
303 exthdr.raw += ipv6_optlen(exthdr.opth);
304 }
305
306 return 0;
307}
308
309static void ah6_output_done(void *data, int err)
310{
311 int extlen;
312 u8 *iph_base;
313 u8 *icv;
314 struct sk_buff *skb = data;
315 struct xfrm_state *x = skb_dst(skb)->xfrm;
316 struct ah_data *ahp = x->data;
317 struct ipv6hdr *top_iph = ipv6_hdr(skb);
318 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
319 struct tmp_ext *iph_ext;
320
321 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
322 if (extlen)
323 extlen += sizeof(*iph_ext);
324
325 iph_base = AH_SKB_CB(skb)->tmp;
326 iph_ext = ah_tmp_ext(base: iph_base);
327 icv = ah_tmp_icv(tmp: iph_ext, offset: extlen);
328
329 memcpy(to: ah->auth_data, from: icv, len: ahp->icv_trunc_len);
330 memcpy(to: top_iph, from: iph_base, IPV6HDR_BASELEN);
331
332 ah6_restore_hdrs(top_iph, iph_ext, extlen);
333
334 kfree(AH_SKB_CB(skb)->tmp);
335 xfrm_output_resume(sk: skb->sk, skb, err);
336}
337
338static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
339{
340 int err;
341 int nfrags;
342 int extlen;
343 u8 *iph_base;
344 u8 *icv;
345 u8 nexthdr;
346 struct sk_buff *trailer;
347 struct crypto_ahash *ahash;
348 struct ahash_request *req;
349 struct scatterlist *sg;
350 struct ipv6hdr *top_iph;
351 struct ip_auth_hdr *ah;
352 struct ah_data *ahp;
353 struct tmp_ext *iph_ext;
354 int seqhi_len = 0;
355 __be32 *seqhi;
356 int sglists = 0;
357 struct scatterlist *seqhisg;
358
359 ahp = x->data;
360 ahash = ahp->ahash;
361
362 err = skb_cow_data(skb, tailbits: 0, trailer: &trailer);
363 if (err < 0)
364 goto out;
365 nfrags = err;
366
367 skb_push(skb, len: -skb_network_offset(skb));
368 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
369 if (extlen)
370 extlen += sizeof(*iph_ext);
371
372 if (x->props.flags & XFRM_STATE_ESN) {
373 sglists = 1;
374 seqhi_len = sizeof(*seqhi);
375 }
376 err = -ENOMEM;
377 iph_base = ah_alloc_tmp(ahash, nfrags: nfrags + sglists, IPV6HDR_BASELEN +
378 extlen + seqhi_len);
379 if (!iph_base)
380 goto out;
381
382 iph_ext = ah_tmp_ext(base: iph_base);
383 seqhi = (__be32 *)((char *)iph_ext + extlen);
384 icv = ah_tmp_icv(tmp: seqhi, offset: seqhi_len);
385 req = ah_tmp_req(ahash, icv);
386 sg = ah_req_sg(ahash, req);
387 seqhisg = sg + nfrags;
388
389 ah = ip_auth_hdr(skb);
390 memset(s: ah->auth_data, c: 0, n: ahp->icv_trunc_len);
391
392 top_iph = ipv6_hdr(skb);
393 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
394
395 nexthdr = *skb_mac_header(skb);
396 *skb_mac_header(skb) = IPPROTO_AH;
397
398 /* When there are no extension headers, we only need to save the first
399 * 8 bytes of the base IP header.
400 */
401 memcpy(to: iph_base, from: top_iph, IPV6HDR_BASELEN);
402
403 ah6_save_hdrs(iph_ext, top_iph, extlen);
404 if (extlen) {
405 err = ipv6_clear_mutable_options(iph: top_iph,
406 len: extlen - sizeof(*iph_ext) +
407 sizeof(*top_iph),
408 dir: XFRM_POLICY_OUT);
409 if (err)
410 goto out_free;
411 }
412
413 ah->nexthdr = nexthdr;
414
415 top_iph->priority = 0;
416 top_iph->flow_lbl[0] = 0;
417 top_iph->flow_lbl[1] = 0;
418 top_iph->flow_lbl[2] = 0;
419 top_iph->hop_limit = 0;
420
421 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
422
423 ah->reserved = 0;
424 ah->spi = x->id.spi;
425 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
426
427 sg_init_table(sg, nfrags + sglists);
428 err = skb_to_sgvec_nomark(skb, sg, offset: 0, len: skb->len);
429 if (unlikely(err < 0))
430 goto out_free;
431
432 if (x->props.flags & XFRM_STATE_ESN) {
433 /* Attach seqhi sg right after packet payload */
434 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
435 sg_set_buf(sg: seqhisg, buf: seqhi, buflen: seqhi_len);
436 }
437 ahash_request_set_crypt(req, src: sg, result: icv, nbytes: skb->len + seqhi_len);
438 ahash_request_set_callback(req, flags: 0, compl: ah6_output_done, data: skb);
439
440 AH_SKB_CB(skb)->tmp = iph_base;
441
442 err = crypto_ahash_digest(req);
443 if (err) {
444 if (err == -EINPROGRESS)
445 goto out;
446
447 if (err == -ENOSPC)
448 err = NET_XMIT_DROP;
449 goto out_free;
450 }
451
452 memcpy(to: ah->auth_data, from: icv, len: ahp->icv_trunc_len);
453 memcpy(to: top_iph, from: iph_base, IPV6HDR_BASELEN);
454
455 ah6_restore_hdrs(top_iph, iph_ext, extlen);
456
457out_free:
458 kfree(objp: iph_base);
459out:
460 return err;
461}
462
463static void ah6_input_done(void *data, int err)
464{
465 u8 *auth_data;
466 u8 *icv;
467 u8 *work_iph;
468 struct sk_buff *skb = data;
469 struct xfrm_state *x = xfrm_input_state(skb);
470 struct ah_data *ahp = x->data;
471 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
472 int hdr_len = skb_network_header_len(skb);
473 int ah_hlen = ipv6_authlen(ah);
474
475 if (err)
476 goto out;
477
478 work_iph = AH_SKB_CB(skb)->tmp;
479 auth_data = ah_tmp_auth(tmp: work_iph, offset: hdr_len);
480 icv = ah_tmp_icv(tmp: auth_data, offset: ahp->icv_trunc_len);
481
482 err = crypto_memneq(a: icv, b: auth_data, size: ahp->icv_trunc_len) ? -EBADMSG : 0;
483 if (err)
484 goto out;
485
486 err = ah->nexthdr;
487
488 skb->network_header += ah_hlen;
489 memcpy(to: skb_network_header(skb), from: work_iph, len: hdr_len);
490 __skb_pull(skb, len: ah_hlen + hdr_len);
491 if (x->props.mode == XFRM_MODE_TUNNEL)
492 skb_reset_transport_header(skb);
493 else
494 skb_set_transport_header(skb, offset: -hdr_len);
495out:
496 kfree(AH_SKB_CB(skb)->tmp);
497 xfrm_input_resume(skb, nexthdr: err);
498}
499
500
501
502static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
503{
504 /*
505 * Before process AH
506 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
507 * |<-------------->| hdr_len
508 *
509 * To erase AH:
510 * Keeping copy of cleared headers. After AH processing,
511 * Moving the pointer of skb->network_header by using skb_pull as long
512 * as AH header length. Then copy back the copy as long as hdr_len
513 * If destination header following AH exists, copy it into after [Ext2].
514 *
515 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
516 * There is offset of AH before IPv6 header after the process.
517 */
518
519 u8 *auth_data;
520 u8 *icv;
521 u8 *work_iph;
522 struct sk_buff *trailer;
523 struct crypto_ahash *ahash;
524 struct ahash_request *req;
525 struct scatterlist *sg;
526 struct ip_auth_hdr *ah;
527 struct ipv6hdr *ip6h;
528 struct ah_data *ahp;
529 u16 hdr_len;
530 u16 ah_hlen;
531 int nexthdr;
532 int nfrags;
533 int err = -ENOMEM;
534 int seqhi_len = 0;
535 __be32 *seqhi;
536 int sglists = 0;
537 struct scatterlist *seqhisg;
538
539 if (!pskb_may_pull(skb, len: sizeof(struct ip_auth_hdr)))
540 goto out;
541
542 /* We are going to _remove_ AH header to keep sockets happy,
543 * so... Later this can change. */
544 if (skb_unclone(skb, GFP_ATOMIC))
545 goto out;
546
547 skb->ip_summed = CHECKSUM_NONE;
548
549 hdr_len = skb_network_header_len(skb);
550 ah = (struct ip_auth_hdr *)skb->data;
551 ahp = x->data;
552 ahash = ahp->ahash;
553
554 nexthdr = ah->nexthdr;
555 ah_hlen = ipv6_authlen(ah);
556
557 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
558 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
559 goto out;
560
561 if (!pskb_may_pull(skb, len: ah_hlen))
562 goto out;
563
564 err = skb_cow_data(skb, tailbits: 0, trailer: &trailer);
565 if (err < 0)
566 goto out;
567 nfrags = err;
568
569 ah = (struct ip_auth_hdr *)skb->data;
570 ip6h = ipv6_hdr(skb);
571
572 skb_push(skb, len: hdr_len);
573
574 if (x->props.flags & XFRM_STATE_ESN) {
575 sglists = 1;
576 seqhi_len = sizeof(*seqhi);
577 }
578
579 work_iph = ah_alloc_tmp(ahash, nfrags: nfrags + sglists, size: hdr_len +
580 ahp->icv_trunc_len + seqhi_len);
581 if (!work_iph) {
582 err = -ENOMEM;
583 goto out;
584 }
585
586 auth_data = ah_tmp_auth(tmp: (u8 *)work_iph, offset: hdr_len);
587 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
588 icv = ah_tmp_icv(tmp: seqhi, offset: seqhi_len);
589 req = ah_tmp_req(ahash, icv);
590 sg = ah_req_sg(ahash, req);
591 seqhisg = sg + nfrags;
592
593 memcpy(to: work_iph, from: ip6h, len: hdr_len);
594 memcpy(to: auth_data, from: ah->auth_data, len: ahp->icv_trunc_len);
595 memset(s: ah->auth_data, c: 0, n: ahp->icv_trunc_len);
596
597 err = ipv6_clear_mutable_options(iph: ip6h, len: hdr_len, dir: XFRM_POLICY_IN);
598 if (err)
599 goto out_free;
600
601 ip6h->priority = 0;
602 ip6h->flow_lbl[0] = 0;
603 ip6h->flow_lbl[1] = 0;
604 ip6h->flow_lbl[2] = 0;
605 ip6h->hop_limit = 0;
606
607 sg_init_table(sg, nfrags + sglists);
608 err = skb_to_sgvec_nomark(skb, sg, offset: 0, len: skb->len);
609 if (unlikely(err < 0))
610 goto out_free;
611
612 if (x->props.flags & XFRM_STATE_ESN) {
613 /* Attach seqhi sg right after packet payload */
614 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
615 sg_set_buf(sg: seqhisg, buf: seqhi, buflen: seqhi_len);
616 }
617
618 ahash_request_set_crypt(req, src: sg, result: icv, nbytes: skb->len + seqhi_len);
619 ahash_request_set_callback(req, flags: 0, compl: ah6_input_done, data: skb);
620
621 AH_SKB_CB(skb)->tmp = work_iph;
622
623 err = crypto_ahash_digest(req);
624 if (err) {
625 if (err == -EINPROGRESS)
626 goto out;
627
628 goto out_free;
629 }
630
631 err = crypto_memneq(a: icv, b: auth_data, size: ahp->icv_trunc_len) ? -EBADMSG : 0;
632 if (err)
633 goto out_free;
634
635 skb->network_header += ah_hlen;
636 memcpy(to: skb_network_header(skb), from: work_iph, len: hdr_len);
637 __skb_pull(skb, len: ah_hlen + hdr_len);
638
639 if (x->props.mode == XFRM_MODE_TUNNEL)
640 skb_reset_transport_header(skb);
641 else
642 skb_set_transport_header(skb, offset: -hdr_len);
643
644 err = nexthdr;
645
646out_free:
647 kfree(objp: work_iph);
648out:
649 return err;
650}
651
652static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
653 u8 type, u8 code, int offset, __be32 info)
654{
655 struct net *net = dev_net(dev: skb->dev);
656 struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
657 struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset);
658 struct xfrm_state *x;
659
660 if (type != ICMPV6_PKT_TOOBIG &&
661 type != NDISC_REDIRECT)
662 return 0;
663
664 x = xfrm_state_lookup(net, mark: skb->mark, daddr: (xfrm_address_t *)&iph->daddr, spi: ah->spi, IPPROTO_AH, AF_INET6);
665 if (!x)
666 return 0;
667
668 if (type == NDISC_REDIRECT)
669 ip6_redirect(skb, net, oif: skb->dev->ifindex, mark: 0,
670 uid: sock_net_uid(net, NULL));
671 else
672 ip6_update_pmtu(skb, net, mtu: info, oif: 0, mark: 0, uid: sock_net_uid(net, NULL));
673 xfrm_state_put(x);
674
675 return 0;
676}
677
678static int ah6_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
679{
680 struct ah_data *ahp = NULL;
681 struct xfrm_algo_desc *aalg_desc;
682 struct crypto_ahash *ahash;
683
684 if (!x->aalg) {
685 NL_SET_ERR_MSG(extack, "AH requires a state with an AUTH algorithm");
686 goto error;
687 }
688
689 if (x->encap) {
690 NL_SET_ERR_MSG(extack, "AH is not compatible with encapsulation");
691 goto error;
692 }
693
694 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
695 if (!ahp)
696 return -ENOMEM;
697
698 ahash = crypto_alloc_ahash(alg_name: x->aalg->alg_name, type: 0, mask: 0);
699 if (IS_ERR(ptr: ahash)) {
700 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
701 goto error;
702 }
703
704 ahp->ahash = ahash;
705 if (crypto_ahash_setkey(tfm: ahash, key: x->aalg->alg_key,
706 keylen: (x->aalg->alg_key_len + 7) / 8)) {
707 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
708 goto error;
709 }
710
711 /*
712 * Lookup the algorithm description maintained by xfrm_algo,
713 * verify crypto transform properties, and store information
714 * we need for AH processing. This lookup cannot fail here
715 * after a successful crypto_alloc_hash().
716 */
717 aalg_desc = xfrm_aalg_get_byname(name: x->aalg->alg_name, probe: 0);
718 BUG_ON(!aalg_desc);
719
720 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
721 crypto_ahash_digestsize(tfm: ahash)) {
722 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
723 goto error;
724 }
725
726 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
727 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
728
729 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
730 ahp->icv_trunc_len);
731 switch (x->props.mode) {
732 case XFRM_MODE_BEET:
733 case XFRM_MODE_TRANSPORT:
734 break;
735 case XFRM_MODE_TUNNEL:
736 x->props.header_len += sizeof(struct ipv6hdr);
737 break;
738 default:
739 NL_SET_ERR_MSG(extack, "Invalid mode requested for AH, must be one of TRANSPORT, TUNNEL, BEET");
740 goto error;
741 }
742 x->data = ahp;
743
744 return 0;
745
746error:
747 if (ahp) {
748 crypto_free_ahash(tfm: ahp->ahash);
749 kfree(objp: ahp);
750 }
751 return -EINVAL;
752}
753
754static void ah6_destroy(struct xfrm_state *x)
755{
756 struct ah_data *ahp = x->data;
757
758 if (!ahp)
759 return;
760
761 crypto_free_ahash(tfm: ahp->ahash);
762 kfree(objp: ahp);
763}
764
765static int ah6_rcv_cb(struct sk_buff *skb, int err)
766{
767 return 0;
768}
769
770static const struct xfrm_type ah6_type = {
771 .owner = THIS_MODULE,
772 .proto = IPPROTO_AH,
773 .flags = XFRM_TYPE_REPLAY_PROT,
774 .init_state = ah6_init_state,
775 .destructor = ah6_destroy,
776 .input = ah6_input,
777 .output = ah6_output,
778};
779
780static struct xfrm6_protocol ah6_protocol = {
781 .handler = xfrm6_rcv,
782 .input_handler = xfrm_input,
783 .cb_handler = ah6_rcv_cb,
784 .err_handler = ah6_err,
785 .priority = 0,
786};
787
788static int __init ah6_init(void)
789{
790 if (xfrm_register_type(type: &ah6_type, AF_INET6) < 0) {
791 pr_info("%s: can't add xfrm type\n", __func__);
792 return -EAGAIN;
793 }
794
795 if (xfrm6_protocol_register(handler: &ah6_protocol, IPPROTO_AH) < 0) {
796 pr_info("%s: can't add protocol\n", __func__);
797 xfrm_unregister_type(type: &ah6_type, AF_INET6);
798 return -EAGAIN;
799 }
800
801 return 0;
802}
803
804static void __exit ah6_fini(void)
805{
806 if (xfrm6_protocol_deregister(handler: &ah6_protocol, IPPROTO_AH) < 0)
807 pr_info("%s: can't remove protocol\n", __func__);
808
809 xfrm_unregister_type(type: &ah6_type, AF_INET6);
810}
811
812module_init(ah6_init);
813module_exit(ah6_fini);
814
815MODULE_DESCRIPTION("IPv6 AH transformation helpers");
816MODULE_LICENSE("GPL");
817MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);
818