blob: c1589e2f1dc9f57d975b94a4a086121ff6bdac92 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C)2002 USAGI/WIDE Project
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09003 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +09008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 * 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.
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090013 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 * 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 *
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090020 * Mitsuru KANDA @USAGI : IPv6 Support
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * Kazunori MIYAZAWA @USAGI :
22 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090023 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * This file is derived from net/ipv4/ah.c.
25 */
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/module.h>
28#include <net/ip.h>
29#include <net/ah.h>
30#include <linux/crypto.h>
31#include <linux/pfkeyv2.h>
Herbert Xub7c65382007-10-09 13:33:35 -070032#include <linux/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/string.h>
34#include <net/icmp.h>
35#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020036#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <net/xfrm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39static int zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
40{
41 u8 *opt = (u8 *)opthdr;
42 int len = ipv6_optlen(opthdr);
43 int off = 0;
44 int optlen = 0;
45
46 off += 2;
47 len -= 2;
48
49 while (len > 0) {
50
51 switch (opt[off]) {
52
53 case IPV6_TLV_PAD0:
54 optlen = 1;
55 break;
56 default:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090057 if (len < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 goto bad;
59 optlen = opt[off+1]+2;
60 if (len < optlen)
61 goto bad;
62 if (opt[off] & 0x20)
63 memset(&opt[off+2], 0, opt[off+1]);
64 break;
65 }
66
67 off += optlen;
68 len -= optlen;
69 }
70 if (len == 0)
71 return 1;
72
73bad:
74 return 0;
75}
76
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -070077#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -070078/**
79 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
80 * @iph: IPv6 header
81 * @destopt: destionation options header
82 */
83static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
84{
85 u8 *opt = (u8 *)destopt;
86 int len = ipv6_optlen(destopt);
87 int off = 0;
88 int optlen = 0;
89
90 off += 2;
91 len -= 2;
92
93 while (len > 0) {
94
95 switch (opt[off]) {
96
97 case IPV6_TLV_PAD0:
98 optlen = 1;
99 break;
100 default:
101 if (len < 2)
102 goto bad;
103 optlen = opt[off+1]+2;
104 if (len < optlen)
105 goto bad;
106
107 /* Rearrange the source address in @iph and the
108 * addresses in home address option for final source.
109 * See 11.3.2 of RFC 3775 for details.
110 */
111 if (opt[off] == IPV6_TLV_HAO) {
112 struct in6_addr final_addr;
113 struct ipv6_destopt_hao *hao;
114
115 hao = (struct ipv6_destopt_hao *)&opt[off];
116 if (hao->length != sizeof(hao->addr)) {
117 if (net_ratelimit())
118 printk(KERN_WARNING "destopt hao: invalid header length: %u\n", hao->length);
119 goto bad;
120 }
121 ipv6_addr_copy(&final_addr, &hao->addr);
122 ipv6_addr_copy(&hao->addr, &iph->saddr);
123 ipv6_addr_copy(&iph->saddr, &final_addr);
124 }
125 break;
126 }
127
128 off += optlen;
129 len -= optlen;
130 }
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900131 /* Note: ok if len == 0 */
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700132bad:
133 return;
134}
Masahide NAKAMURA136ebf02007-06-26 23:51:41 -0700135#else
136static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700137#endif
138
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139/**
140 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
141 * @iph: IPv6 header
142 * @rthdr: routing header
143 *
144 * Rearrange the destination address in @iph and the addresses in @rthdr
145 * so that they appear in the order they will at the final destination.
146 * See Appendix A2 of RFC 2402 for details.
147 */
148static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
149{
150 int segments, segments_left;
151 struct in6_addr *addrs;
152 struct in6_addr final_addr;
153
154 segments_left = rthdr->segments_left;
155 if (segments_left == 0)
156 return;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900157 rthdr->segments_left = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158
159 /* The value of rthdr->hdrlen has been verified either by the system
160 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
161 * packets. So we can assume that it is even and that segments is
162 * greater than or equal to segments_left.
163 *
164 * For the same reason we can assume that this option is of type 0.
165 */
166 segments = rthdr->hdrlen >> 1;
167
168 addrs = ((struct rt0_hdr *)rthdr)->addr;
169 ipv6_addr_copy(&final_addr, addrs + segments - 1);
170
171 addrs += segments - segments_left;
172 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
173
174 ipv6_addr_copy(addrs, &iph->daddr);
175 ipv6_addr_copy(&iph->daddr, &final_addr);
176}
177
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700178static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179{
180 union {
181 struct ipv6hdr *iph;
182 struct ipv6_opt_hdr *opth;
183 struct ipv6_rt_hdr *rth;
184 char *raw;
185 } exthdr = { .iph = iph };
186 char *end = exthdr.raw + len;
187 int nexthdr = iph->nexthdr;
188
189 exthdr.iph++;
190
191 while (exthdr.raw < end) {
192 switch (nexthdr) {
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700193 case NEXTHDR_DEST:
194 if (dir == XFRM_POLICY_OUT)
195 ipv6_rearrange_destopt(iph, exthdr.opth);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900196 case NEXTHDR_HOP:
197 if (!zero_out_mutable_opts(exthdr.opth)) {
198 LIMIT_NETDEBUG(
199 KERN_WARNING "overrun %sopts\n",
200 nexthdr == NEXTHDR_HOP ?
201 "hop" : "dest");
202 return -EINVAL;
203 }
204 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
206 case NEXTHDR_ROUTING:
207 ipv6_rearrange_rthdr(iph, exthdr.rth);
208 break;
209
210 default :
211 return 0;
212 }
213
214 nexthdr = exthdr.opth->nexthdr;
215 exthdr.raw += ipv6_optlen(exthdr.opth);
216 }
217
218 return 0;
219}
220
221static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
222{
223 int err;
224 int extlen;
225 struct ipv6hdr *top_iph;
226 struct ip_auth_hdr *ah;
227 struct ah_data *ahp;
228 u8 nexthdr;
229 char tmp_base[8];
230 struct {
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -0700231#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700232 struct in6_addr saddr;
233#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 struct in6_addr daddr;
235 char hdrs[0];
236 } *tmp_ext;
237
Herbert Xu7b277b12007-10-10 15:44:06 -0700238 skb_push(skb, -skb_network_offset(skb));
Herbert Xu007f0212007-10-09 13:25:59 -0700239 top_iph = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
241
Herbert Xu007f0212007-10-09 13:25:59 -0700242 nexthdr = *skb_mac_header(skb);
243 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
245 /* When there are no extension headers, we only need to save the first
246 * 8 bytes of the base IP header.
247 */
248 memcpy(tmp_base, top_iph, sizeof(tmp_base));
249
250 tmp_ext = NULL;
Kazunori MIYAZAWA144466b2007-05-25 01:22:25 -0700251 extlen = skb_transport_offset(skb) - sizeof(struct ipv6hdr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 if (extlen) {
253 extlen += sizeof(*tmp_ext);
254 tmp_ext = kmalloc(extlen, GFP_ATOMIC);
255 if (!tmp_ext) {
256 err = -ENOMEM;
257 goto error;
258 }
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -0700259#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700260 memcpy(tmp_ext, &top_iph->saddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900261#else
262 memcpy(tmp_ext, &top_iph->daddr, extlen);
263#endif
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700264 err = ipv6_clear_mutable_options(top_iph,
265 extlen - sizeof(*tmp_ext) +
266 sizeof(*top_iph),
267 XFRM_POLICY_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268 if (err)
269 goto error_free_iph;
270 }
271
Herbert Xu87bdc482007-10-10 15:45:25 -0700272 ah = ip_auth_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 ah->nexthdr = nexthdr;
274
275 top_iph->priority = 0;
276 top_iph->flow_lbl[0] = 0;
277 top_iph->flow_lbl[1] = 0;
278 top_iph->flow_lbl[2] = 0;
279 top_iph->hop_limit = 0;
280
281 ahp = x->data;
Herbert Xu87bdc482007-10-10 15:45:25 -0700282 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 ah->reserved = 0;
285 ah->spi = x->id.spi;
Herbert Xub318e0e2008-02-12 22:50:35 -0800286 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output);
Herbert Xub7c65382007-10-09 13:33:35 -0700287
288 spin_lock_bh(&x->lock);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000289 err = ah_mac_digest(ahp, skb, ah->auth_data);
Herbert Xub7c65382007-10-09 13:33:35 -0700290 memcpy(ah->auth_data, ahp->work_icv, ahp->icv_trunc_len);
291 spin_unlock_bh(&x->lock);
292
Herbert Xu07d4ee52006-08-20 14:24:50 +1000293 if (err)
294 goto error_free_iph;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
296 memcpy(top_iph, tmp_base, sizeof(tmp_base));
297 if (tmp_ext) {
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -0700298#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700299 memcpy(&top_iph->saddr, tmp_ext, extlen);
300#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 memcpy(&top_iph->daddr, tmp_ext, extlen);
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700302#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303error_free_iph:
304 kfree(tmp_ext);
305 }
306
307error:
308 return err;
309}
310
Herbert Xue6956332006-04-01 00:52:46 -0800311static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312{
313 /*
314 * Before process AH
315 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
316 * |<-------------->| hdr_len
317 *
318 * To erase AH:
319 * Keeping copy of cleared headers. After AH processing,
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700320 * Moving the pointer of skb->network_header by using skb_pull as long
321 * as AH header length. Then copy back the copy as long as hdr_len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 * If destination header following AH exists, copy it into after [Ext2].
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900323 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
325 * There is offset of AH before IPv6 header after the process.
326 */
327
Herbert Xu87bdc482007-10-10 15:45:25 -0700328 struct ip_auth_hdr *ah;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700329 struct ipv6hdr *ip6h;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 struct ah_data *ahp;
331 unsigned char *tmp_hdr = NULL;
332 u16 hdr_len;
333 u16 ah_hlen;
334 int nexthdr;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000335 int err = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
338 goto out;
339
340 /* We are going to _remove_ AH header to keep sockets happy,
341 * so... Later this can change. */
342 if (skb_cloned(skb) &&
343 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
344 goto out;
345
Herbert Xu7aa68cb2007-10-17 21:30:07 -0700346 skb->ip_summed = CHECKSUM_NONE;
347
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700348 hdr_len = skb->data - skb_network_header(skb);
Herbert Xu87bdc482007-10-10 15:45:25 -0700349 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 ahp = x->data;
351 nexthdr = ah->nexthdr;
352 ah_hlen = (ah->hdrlen + 2) << 2;
353
Herbert Xu87bdc482007-10-10 15:45:25 -0700354 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
355 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900356 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
358 if (!pskb_may_pull(skb, ah_hlen))
359 goto out;
360
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700361 tmp_hdr = kmemdup(skb_network_header(skb), hdr_len, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362 if (!tmp_hdr)
363 goto out;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700364 ip6h = ipv6_hdr(skb);
365 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700366 goto free_out;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700367 ip6h->priority = 0;
368 ip6h->flow_lbl[0] = 0;
369 ip6h->flow_lbl[1] = 0;
370 ip6h->flow_lbl[2] = 0;
371 ip6h->hop_limit = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800373 spin_lock(&x->lock);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900374 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 u8 auth_data[MAX_AH_AUTH_LEN];
376
377 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
378 memset(ah->auth_data, 0, ahp->icv_trunc_len);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700379 skb_push(skb, hdr_len);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000380 err = ah_mac_digest(ahp, skb, ah->auth_data);
381 if (err)
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800382 goto unlock;
Herbert Xu9dd32452007-12-30 21:10:30 -0800383 if (memcmp(ahp->work_icv, auth_data, ahp->icv_trunc_len))
Herbert Xu668dc8a2007-12-16 15:55:02 -0800384 err = -EBADMSG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800386unlock:
387 spin_unlock(&x->lock);
388
389 if (err)
390 goto free_out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700392 skb->network_header += ah_hlen;
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700393 memcpy(skb_network_header(skb), tmp_hdr, hdr_len);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700394 skb->transport_header = skb->network_header;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700395 __skb_pull(skb, ah_hlen + hdr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
397 kfree(tmp_hdr);
398
399 return nexthdr;
400
401free_out:
402 kfree(tmp_hdr);
403out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000404 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405}
406
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900407static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
Brian Haleyd5fdd6b2009-06-23 04:31:07 -0700408 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800410 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
412 struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset);
413 struct xfrm_state *x;
414
415 if (type != ICMPV6_DEST_UNREACH &&
416 type != ICMPV6_PKT_TOOBIG)
417 return;
418
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800419 x = xfrm_state_lookup(net, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 if (!x)
421 return;
422
Harvey Harrison5b095d9892008-10-29 12:52:50 -0700423 NETDEBUG(KERN_DEBUG "pmtu discovery on SA AH/%08x/%pI6\n",
Harvey Harrison0c6ce782008-10-28 16:09:23 -0700424 ntohl(ah->spi), &iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 xfrm_state_put(x);
427}
428
Herbert Xu72cb6962005-06-20 13:18:08 -0700429static int ah6_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430{
431 struct ah_data *ahp = NULL;
432 struct xfrm_algo_desc *aalg_desc;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000433 struct crypto_hash *tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 if (!x->aalg)
436 goto error;
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 if (x->encap)
439 goto error;
440
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800441 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 if (ahp == NULL)
443 return -ENOMEM;
444
Herbert Xu07d4ee52006-08-20 14:24:50 +1000445 tfm = crypto_alloc_hash(x->aalg->alg_name, 0, CRYPTO_ALG_ASYNC);
446 if (IS_ERR(tfm))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000448
449 ahp->tfm = tfm;
Herbert Xubc31d3b2007-10-08 17:14:34 -0700450 if (crypto_hash_setkey(tfm, x->aalg->alg_key,
451 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000452 goto error;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 /*
455 * Lookup the algorithm description maintained by xfrm_algo,
456 * verify crypto transform properties, and store information
457 * we need for AH processing. This lookup cannot fail here
Herbert Xu07d4ee52006-08-20 14:24:50 +1000458 * after a successful crypto_alloc_hash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 */
460 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
461 BUG_ON(!aalg_desc);
462
463 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Herbert Xu07d4ee52006-08-20 14:24:50 +1000464 crypto_hash_digestsize(tfm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
Herbert Xu07d4ee52006-08-20 14:24:50 +1000466 x->aalg->alg_name, crypto_hash_digestsize(tfm),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 aalg_desc->uinfo.auth.icv_fullbits/8);
468 goto error;
469 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
472 ahp->icv_trunc_len = aalg_desc->uinfo.auth.icv_truncbits/8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900473
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900475
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 ahp->work_icv = kmalloc(ahp->icv_full_len, GFP_KERNEL);
477 if (!ahp->work_icv)
478 goto error;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900479
Herbert Xu87bdc482007-10-10 15:45:25 -0700480 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
481 ahp->icv_trunc_len);
Herbert Xuca681452007-10-17 21:35:15 -0700482 switch (x->props.mode) {
483 case XFRM_MODE_BEET:
484 case XFRM_MODE_TRANSPORT:
485 break;
486 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700488 break;
Herbert Xuca681452007-10-17 21:35:15 -0700489 default:
490 goto error;
491 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 x->data = ahp;
493
494 return 0;
495
496error:
497 if (ahp) {
Jesper Juhl573dbd92005-09-01 17:44:29 -0700498 kfree(ahp->work_icv);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000499 crypto_free_hash(ahp->tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 kfree(ahp);
501 }
502 return -EINVAL;
503}
504
505static void ah6_destroy(struct xfrm_state *x)
506{
507 struct ah_data *ahp = x->data;
508
509 if (!ahp)
510 return;
511
Jesper Juhl573dbd92005-09-01 17:44:29 -0700512 kfree(ahp->work_icv);
Herbert Xu07d4ee52006-08-20 14:24:50 +1000513 crypto_free_hash(ahp->tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 kfree(ahp);
515}
516
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800517static const struct xfrm_type ah6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518{
519 .description = "AH6",
520 .owner = THIS_MODULE,
521 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700522 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 .init_state = ah6_init_state,
524 .destructor = ah6_destroy,
525 .input = ah6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700526 .output = ah6_output,
527 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528};
529
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000530static const struct inet6_protocol ah6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 .handler = xfrm6_rcv,
532 .err_handler = ah6_err,
533 .flags = INET6_PROTO_NOPOLICY,
534};
535
536static int __init ah6_init(void)
537{
538 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
539 printk(KERN_INFO "ipv6 ah init: can't add xfrm type\n");
540 return -EAGAIN;
541 }
542
543 if (inet6_add_protocol(&ah6_protocol, IPPROTO_AH) < 0) {
544 printk(KERN_INFO "ipv6 ah init: can't add protocol\n");
545 xfrm_unregister_type(&ah6_type, AF_INET6);
546 return -EAGAIN;
547 }
548
549 return 0;
550}
551
552static void __exit ah6_fini(void)
553{
554 if (inet6_del_protocol(&ah6_protocol, IPPROTO_AH) < 0)
555 printk(KERN_INFO "ipv6 ah close: can't remove protocol\n");
556
557 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
558 printk(KERN_INFO "ipv6 ah close: can't remove xfrm type\n");
559
560}
561
562module_init(ah6_init);
563module_exit(ah6_fini);
564
565MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700566MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);