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, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17 *
18 * Authors
19 *
20 *	Mitsuru KANDA @USAGI       : IPv6 Support
21 * 	Kazunori MIYAZAWA @USAGI   :
22 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
23 *
24 * 	This file is derived from net/ipv4/ah.c.
25 */
26
27#include <crypto/hash.h>
28#include <linux/module.h>
29#include <linux/slab.h>
30#include <net/ip.h>
31#include <net/ah.h>
32#include <linux/crypto.h>
33#include <linux/pfkeyv2.h>
34#include <linux/string.h>
35#include <linux/scatterlist.h>
36#include <net/icmp.h>
37#include <net/ipv6.h>
38#include <net/protocol.h>
39#include <net/xfrm.h>
40
41#define IPV6HDR_BASELEN 8
42
43struct tmp_ext {
44#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
45		struct in6_addr saddr;
46#endif
47		struct in6_addr daddr;
48		char hdrs[0];
49};
50
51struct ah_skb_cb {
52	struct xfrm_skb_cb xfrm;
53	void *tmp;
54};
55
56#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
57
58static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
59			  unsigned int size)
60{
61	unsigned int len;
62
63	len = size + crypto_ahash_digestsize(ahash) +
64	      (crypto_ahash_alignmask(ahash) &
65	       ~(crypto_tfm_ctx_alignment() - 1));
66
67	len = ALIGN(len, crypto_tfm_ctx_alignment());
68
69	len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
70	len = ALIGN(len, __alignof__(struct scatterlist));
71
72	len += sizeof(struct scatterlist) * nfrags;
73
74	return kmalloc(len, GFP_ATOMIC);
75}
76
77static inline struct tmp_ext *ah_tmp_ext(void *base)
78{
79	return base + IPV6HDR_BASELEN;
80}
81
82static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
83{
84	return tmp + offset;
85}
86
87static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
88			     unsigned int offset)
89{
90	return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
91}
92
93static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
94					       u8 *icv)
95{
96	struct ahash_request *req;
97
98	req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
99				crypto_tfm_ctx_alignment());
100
101	ahash_request_set_tfm(req, ahash);
102
103	return req;
104}
105
106static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
107					     struct ahash_request *req)
108{
109	return (void *)ALIGN((unsigned long)(req + 1) +
110			     crypto_ahash_reqsize(ahash),
111			     __alignof__(struct scatterlist));
112}
113
114static int zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
115{
116	u8 *opt = (u8 *)opthdr;
117	int len = ipv6_optlen(opthdr);
118	int off = 0;
119	int optlen = 0;
120
121	off += 2;
122	len -= 2;
123
124	while (len > 0) {
125
126		switch (opt[off]) {
127
128		case IPV6_TLV_PAD0:
129			optlen = 1;
130			break;
131		default:
132			if (len < 2)
133				goto bad;
134			optlen = opt[off+1]+2;
135			if (len < optlen)
136				goto bad;
137			if (opt[off] & 0x20)
138				memset(&opt[off+2], 0, opt[off+1]);
139			break;
140		}
141
142		off += optlen;
143		len -= optlen;
144	}
145	if (len == 0)
146		return 1;
147
148bad:
149	return 0;
150}
151
152#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
153/**
154 *	ipv6_rearrange_destopt - rearrange IPv6 destination options header
155 *	@iph: IPv6 header
156 *	@destopt: destionation options header
157 */
158static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
159{
160	u8 *opt = (u8 *)destopt;
161	int len = ipv6_optlen(destopt);
162	int off = 0;
163	int optlen = 0;
164
165	off += 2;
166	len -= 2;
167
168	while (len > 0) {
169
170		switch (opt[off]) {
171
172		case IPV6_TLV_PAD0:
173			optlen = 1;
174			break;
175		default:
176			if (len < 2)
177				goto bad;
178			optlen = opt[off+1]+2;
179			if (len < optlen)
180				goto bad;
181
182			/* Rearrange the source address in @iph and the
183			 * addresses in home address option for final source.
184			 * See 11.3.2 of RFC 3775 for details.
185			 */
186			if (opt[off] == IPV6_TLV_HAO) {
187				struct in6_addr final_addr;
188				struct ipv6_destopt_hao *hao;
189
190				hao = (struct ipv6_destopt_hao *)&opt[off];
191				if (hao->length != sizeof(hao->addr)) {
192					if (net_ratelimit())
193						printk(KERN_WARNING "destopt hao: invalid header length: %u\n", hao->length);
194					goto bad;
195				}
196				ipv6_addr_copy(&final_addr, &hao->addr);
197				ipv6_addr_copy(&hao->addr, &iph->saddr);
198				ipv6_addr_copy(&iph->saddr, &final_addr);
199			}
200			break;
201		}
202
203		off += optlen;
204		len -= optlen;
205	}
206	/* Note: ok if len == 0 */
207bad:
208	return;
209}
210#else
211static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
212#endif
213
214/**
215 *	ipv6_rearrange_rthdr - rearrange IPv6 routing header
216 *	@iph: IPv6 header
217 *	@rthdr: routing header
218 *
219 *	Rearrange the destination address in @iph and the addresses in @rthdr
220 *	so that they appear in the order they will at the final destination.
221 *	See Appendix A2 of RFC 2402 for details.
222 */
223static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
224{
225	int segments, segments_left;
226	struct in6_addr *addrs;
227	struct in6_addr final_addr;
228
229	segments_left = rthdr->segments_left;
230	if (segments_left == 0)
231		return;
232	rthdr->segments_left = 0;
233
234	/* The value of rthdr->hdrlen has been verified either by the system
235	 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
236	 * packets.  So we can assume that it is even and that segments is
237	 * greater than or equal to segments_left.
238	 *
239	 * For the same reason we can assume that this option is of type 0.
240	 */
241	segments = rthdr->hdrlen >> 1;
242
243	addrs = ((struct rt0_hdr *)rthdr)->addr;
244	ipv6_addr_copy(&final_addr, addrs + segments - 1);
245
246	addrs += segments - segments_left;
247	memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
248
249	ipv6_addr_copy(addrs, &iph->daddr);
250	ipv6_addr_copy(&iph->daddr, &final_addr);
251}
252
253static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
254{
255	union {
256		struct ipv6hdr *iph;
257		struct ipv6_opt_hdr *opth;
258		struct ipv6_rt_hdr *rth;
259		char *raw;
260	} exthdr = { .iph = iph };
261	char *end = exthdr.raw + len;
262	int nexthdr = iph->nexthdr;
263
264	exthdr.iph++;
265
266	while (exthdr.raw < end) {
267		switch (nexthdr) {
268		case NEXTHDR_DEST:
269			if (dir == XFRM_POLICY_OUT)
270				ipv6_rearrange_destopt(iph, exthdr.opth);
271		case NEXTHDR_HOP:
272			if (!zero_out_mutable_opts(exthdr.opth)) {
273				LIMIT_NETDEBUG(
274					KERN_WARNING "overrun %sopts\n",
275					nexthdr == NEXTHDR_HOP ?
276						"hop" : "dest");
277				return -EINVAL;
278			}
279			break;
280
281		case NEXTHDR_ROUTING:
282			ipv6_rearrange_rthdr(iph, exthdr.rth);
283			break;
284
285		default :
286			return 0;
287		}
288
289		nexthdr = exthdr.opth->nexthdr;
290		exthdr.raw += ipv6_optlen(exthdr.opth);
291	}
292
293	return 0;
294}
295
296static void ah6_output_done(struct crypto_async_request *base, int err)
297{
298	int extlen;
299	u8 *iph_base;
300	u8 *icv;
301	struct sk_buff *skb = base->data;
302	struct xfrm_state *x = skb_dst(skb)->xfrm;
303	struct ah_data *ahp = x->data;
304	struct ipv6hdr *top_iph = ipv6_hdr(skb);
305	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
306	struct tmp_ext *iph_ext;
307
308	extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
309	if (extlen)
310		extlen += sizeof(*iph_ext);
311
312	iph_base = AH_SKB_CB(skb)->tmp;
313	iph_ext = ah_tmp_ext(iph_base);
314	icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
315
316	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
317	memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
318
319	if (extlen) {
320#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
321		memcpy(&top_iph->saddr, iph_ext, extlen);
322#else
323		memcpy(&top_iph->daddr, iph_ext, extlen);
324#endif
325	}
326
327	err = ah->nexthdr;
328
329	kfree(AH_SKB_CB(skb)->tmp);
330	xfrm_output_resume(skb, err);
331}
332
333static 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
350	ahp = x->data;
351	ahash = ahp->ahash;
352
353	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
354		goto out;
355	nfrags = err;
356
357	skb_push(skb, -skb_network_offset(skb));
358	extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
359	if (extlen)
360		extlen += sizeof(*iph_ext);
361
362	err = -ENOMEM;
363	iph_base = ah_alloc_tmp(ahash, nfrags, IPV6HDR_BASELEN + extlen);
364	if (!iph_base)
365		goto out;
366
367	iph_ext = ah_tmp_ext(iph_base);
368	icv = ah_tmp_icv(ahash, iph_ext, extlen);
369	req = ah_tmp_req(ahash, icv);
370	sg = ah_req_sg(ahash, req);
371
372	ah = ip_auth_hdr(skb);
373	memset(ah->auth_data, 0, ahp->icv_trunc_len);
374
375	top_iph = ipv6_hdr(skb);
376	top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
377
378	nexthdr = *skb_mac_header(skb);
379	*skb_mac_header(skb) = IPPROTO_AH;
380
381	/* When there are no extension headers, we only need to save the first
382	 * 8 bytes of the base IP header.
383	 */
384	memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
385
386	if (extlen) {
387#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
388		memcpy(iph_ext, &top_iph->saddr, extlen);
389#else
390		memcpy(iph_ext, &top_iph->daddr, extlen);
391#endif
392		err = ipv6_clear_mutable_options(top_iph,
393						 extlen - sizeof(*iph_ext) +
394						 sizeof(*top_iph),
395						 XFRM_POLICY_OUT);
396		if (err)
397			goto out_free;
398	}
399
400	ah->nexthdr = nexthdr;
401
402	top_iph->priority    = 0;
403	top_iph->flow_lbl[0] = 0;
404	top_iph->flow_lbl[1] = 0;
405	top_iph->flow_lbl[2] = 0;
406	top_iph->hop_limit   = 0;
407
408	ah->hdrlen  = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
409
410	ah->reserved = 0;
411	ah->spi = x->id.spi;
412	ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
413
414	sg_init_table(sg, nfrags);
415	skb_to_sgvec(skb, sg, 0, skb->len);
416
417	ahash_request_set_crypt(req, sg, icv, skb->len);
418	ahash_request_set_callback(req, 0, ah6_output_done, skb);
419
420	AH_SKB_CB(skb)->tmp = iph_base;
421
422	err = crypto_ahash_digest(req);
423	if (err) {
424		if (err == -EINPROGRESS)
425			goto out;
426
427		if (err == -EBUSY)
428			err = NET_XMIT_DROP;
429		goto out_free;
430	}
431
432	memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
433	memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
434
435	if (extlen) {
436#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
437		memcpy(&top_iph->saddr, iph_ext, extlen);
438#else
439		memcpy(&top_iph->daddr, iph_ext, extlen);
440#endif
441	}
442
443out_free:
444	kfree(iph_base);
445out:
446	return err;
447}
448
449static void ah6_input_done(struct crypto_async_request *base, int err)
450{
451	u8 *auth_data;
452	u8 *icv;
453	u8 *work_iph;
454	struct sk_buff *skb = base->data;
455	struct xfrm_state *x = xfrm_input_state(skb);
456	struct ah_data *ahp = x->data;
457	struct ip_auth_hdr *ah = ip_auth_hdr(skb);
458	int hdr_len = skb_network_header_len(skb);
459	int ah_hlen = (ah->hdrlen + 2) << 2;
460
461	work_iph = AH_SKB_CB(skb)->tmp;
462	auth_data = ah_tmp_auth(work_iph, hdr_len);
463	icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
464
465	err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
466	if (err)
467		goto out;
468
469	skb->network_header += ah_hlen;
470	memcpy(skb_network_header(skb), work_iph, hdr_len);
471	__skb_pull(skb, ah_hlen + hdr_len);
472	skb_set_transport_header(skb, -hdr_len);
473
474	err = ah->nexthdr;
475out:
476	kfree(AH_SKB_CB(skb)->tmp);
477	xfrm_input_resume(skb, err);
478}
479
480
481
482static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
483{
484	/*
485	 * Before process AH
486	 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
487	 * |<-------------->| hdr_len
488	 *
489	 * To erase AH:
490	 * Keeping copy of cleared headers. After AH processing,
491	 * Moving the pointer of skb->network_header by using skb_pull as long
492	 * as AH header length. Then copy back the copy as long as hdr_len
493	 * If destination header following AH exists, copy it into after [Ext2].
494	 *
495	 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
496	 * There is offset of AH before IPv6 header after the process.
497	 */
498
499	u8 *auth_data;
500	u8 *icv;
501	u8 *work_iph;
502	struct sk_buff *trailer;
503	struct crypto_ahash *ahash;
504	struct ahash_request *req;
505	struct scatterlist *sg;
506	struct ip_auth_hdr *ah;
507	struct ipv6hdr *ip6h;
508	struct ah_data *ahp;
509	u16 hdr_len;
510	u16 ah_hlen;
511	int nexthdr;
512	int nfrags;
513	int err = -ENOMEM;
514
515	if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
516		goto out;
517
518	/* We are going to _remove_ AH header to keep sockets happy,
519	 * so... Later this can change. */
520	if (skb_cloned(skb) &&
521	    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
522		goto out;
523
524	skb->ip_summed = CHECKSUM_NONE;
525
526	hdr_len = skb_network_header_len(skb);
527	ah = (struct ip_auth_hdr *)skb->data;
528	ahp = x->data;
529	ahash = ahp->ahash;
530
531	nexthdr = ah->nexthdr;
532	ah_hlen = (ah->hdrlen + 2) << 2;
533
534	if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
535	    ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
536		goto out;
537
538	if (!pskb_may_pull(skb, ah_hlen))
539		goto out;
540
541	ip6h = ipv6_hdr(skb);
542
543	skb_push(skb, hdr_len);
544
545	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
546		goto out;
547	nfrags = err;
548
549	work_iph = ah_alloc_tmp(ahash, nfrags, hdr_len + ahp->icv_trunc_len);
550	if (!work_iph)
551		goto out;
552
553	auth_data = ah_tmp_auth(work_iph, hdr_len);
554	icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len);
555	req = ah_tmp_req(ahash, icv);
556	sg = ah_req_sg(ahash, req);
557
558	memcpy(work_iph, ip6h, hdr_len);
559	memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
560	memset(ah->auth_data, 0, ahp->icv_trunc_len);
561
562	if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
563		goto out_free;
564
565	ip6h->priority    = 0;
566	ip6h->flow_lbl[0] = 0;
567	ip6h->flow_lbl[1] = 0;
568	ip6h->flow_lbl[2] = 0;
569	ip6h->hop_limit   = 0;
570
571	sg_init_table(sg, nfrags);
572	skb_to_sgvec(skb, sg, 0, skb->len);
573
574	ahash_request_set_crypt(req, sg, icv, skb->len);
575	ahash_request_set_callback(req, 0, ah6_input_done, skb);
576
577	AH_SKB_CB(skb)->tmp = work_iph;
578
579	err = crypto_ahash_digest(req);
580	if (err) {
581		if (err == -EINPROGRESS)
582			goto out;
583
584		if (err == -EBUSY)
585			err = NET_XMIT_DROP;
586		goto out_free;
587	}
588
589	err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
590	if (err)
591		goto out_free;
592
593	skb->network_header += ah_hlen;
594	memcpy(skb_network_header(skb), work_iph, hdr_len);
595	skb->transport_header = skb->network_header;
596	__skb_pull(skb, ah_hlen + hdr_len);
597
598	err = nexthdr;
599
600out_free:
601	kfree(work_iph);
602out:
603	return err;
604}
605
606static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
607		    u8 type, u8 code, int offset, __be32 info)
608{
609	struct net *net = dev_net(skb->dev);
610	struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
611	struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset);
612	struct xfrm_state *x;
613
614	if (type != ICMPV6_DEST_UNREACH &&
615	    type != ICMPV6_PKT_TOOBIG)
616		return;
617
618	x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
619	if (!x)
620		return;
621
622	NETDEBUG(KERN_DEBUG "pmtu discovery on SA AH/%08x/%pI6\n",
623		 ntohl(ah->spi), &iph->daddr);
624
625	xfrm_state_put(x);
626}
627
628static int ah6_init_state(struct xfrm_state *x)
629{
630	struct ah_data *ahp = NULL;
631	struct xfrm_algo_desc *aalg_desc;
632	struct crypto_ahash *ahash;
633
634	if (!x->aalg)
635		goto error;
636
637	if (x->encap)
638		goto error;
639
640	ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
641	if (ahp == NULL)
642		return -ENOMEM;
643
644	ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
645	if (IS_ERR(ahash))
646		goto error;
647
648	ahp->ahash = ahash;
649	if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
650			       (x->aalg->alg_key_len + 7) / 8))
651		goto error;
652
653	/*
654	 * Lookup the algorithm description maintained by xfrm_algo,
655	 * verify crypto transform properties, and store information
656	 * we need for AH processing.  This lookup cannot fail here
657	 * after a successful crypto_alloc_hash().
658	 */
659	aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
660	BUG_ON(!aalg_desc);
661
662	if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
663	    crypto_ahash_digestsize(ahash)) {
664		printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
665		       x->aalg->alg_name, crypto_ahash_digestsize(ahash),
666		       aalg_desc->uinfo.auth.icv_fullbits/8);
667		goto error;
668	}
669
670	ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
671	ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
672
673	BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
674
675	x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
676					  ahp->icv_trunc_len);
677	switch (x->props.mode) {
678	case XFRM_MODE_BEET:
679	case XFRM_MODE_TRANSPORT:
680		break;
681	case XFRM_MODE_TUNNEL:
682		x->props.header_len += sizeof(struct ipv6hdr);
683		break;
684	default:
685		goto error;
686	}
687	x->data = ahp;
688
689	return 0;
690
691error:
692	if (ahp) {
693		crypto_free_ahash(ahp->ahash);
694		kfree(ahp);
695	}
696	return -EINVAL;
697}
698
699static void ah6_destroy(struct xfrm_state *x)
700{
701	struct ah_data *ahp = x->data;
702
703	if (!ahp)
704		return;
705
706	crypto_free_ahash(ahp->ahash);
707	kfree(ahp);
708}
709
710static const struct xfrm_type ah6_type =
711{
712	.description	= "AH6",
713	.owner		= THIS_MODULE,
714	.proto	     	= IPPROTO_AH,
715	.flags		= XFRM_TYPE_REPLAY_PROT,
716	.init_state	= ah6_init_state,
717	.destructor	= ah6_destroy,
718	.input		= ah6_input,
719	.output		= ah6_output,
720	.hdr_offset	= xfrm6_find_1stfragopt,
721};
722
723static const struct inet6_protocol ah6_protocol = {
724	.handler	=	xfrm6_rcv,
725	.err_handler	=	ah6_err,
726	.flags		=	INET6_PROTO_NOPOLICY,
727};
728
729static int __init ah6_init(void)
730{
731	if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
732		printk(KERN_INFO "ipv6 ah init: can't add xfrm type\n");
733		return -EAGAIN;
734	}
735
736	if (inet6_add_protocol(&ah6_protocol, IPPROTO_AH) < 0) {
737		printk(KERN_INFO "ipv6 ah init: can't add protocol\n");
738		xfrm_unregister_type(&ah6_type, AF_INET6);
739		return -EAGAIN;
740	}
741
742	return 0;
743}
744
745static void __exit ah6_fini(void)
746{
747	if (inet6_del_protocol(&ah6_protocol, IPPROTO_AH) < 0)
748		printk(KERN_INFO "ipv6 ah close: can't remove protocol\n");
749
750	if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
751		printk(KERN_INFO "ipv6 ah close: can't remove xfrm type\n");
752
753}
754
755module_init(ah6_init);
756module_exit(ah6_fini);
757
758MODULE_LICENSE("GPL");
759MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);
760