blob: 2ae79dbeec2feb356f1d91f10a9853cc5f1b5706 [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
Steffen Klassert8631e9b2009-10-07 22:49:01 +000027#include <crypto/hash.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <net/ip.h>
31#include <net/ah.h>
32#include <linux/crypto.h>
33#include <linux/pfkeyv2.h>
34#include <linux/string.h>
Steffen Klassert8631e9b2009-10-07 22:49:01 +000035#include <linux/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <net/icmp.h>
37#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020038#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include <net/xfrm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Steffen Klassert8631e9b2009-10-07 22:49:01 +000041#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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114static 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:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900132 if (len < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 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
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -0700152#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700153/**
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 }
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000196 final_addr = hao->addr;
197 hao->addr = iph->saddr;
198 iph->saddr = final_addr;
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700199 }
200 break;
201 }
202
203 off += optlen;
204 len -= optlen;
205 }
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900206 /* Note: ok if len == 0 */
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700207bad:
208 return;
209}
Masahide NAKAMURA136ebf02007-06-26 23:51:41 -0700210#else
211static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700212#endif
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214/**
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;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900232 rthdr->segments_left = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
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;
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000244 final_addr = addrs[segments - 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246 addrs += segments - segments_left;
247 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
248
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000249 addrs[0] = iph->daddr;
250 iph->daddr = final_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251}
252
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700253static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254{
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) {
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700268 case NEXTHDR_DEST:
269 if (dir == XFRM_POLICY_OUT)
270 ipv6_rearrange_destopt(iph, exthdr.opth);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900271 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
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
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000296static 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
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000327 kfree(AH_SKB_CB(skb)->tmp);
328 xfrm_output_resume(skb, err);
329}
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
332{
333 int err;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000334 int nfrags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 int extlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000336 u8 *iph_base;
337 u8 *icv;
338 u8 nexthdr;
339 struct sk_buff *trailer;
340 struct crypto_ahash *ahash;
341 struct ahash_request *req;
342 struct scatterlist *sg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 struct ipv6hdr *top_iph;
344 struct ip_auth_hdr *ah;
345 struct ah_data *ahp;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000346 struct tmp_ext *iph_ext;
347
348 ahp = x->data;
349 ahash = ahp->ahash;
350
351 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
352 goto out;
353 nfrags = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
Herbert Xu7b277b12007-10-10 15:44:06 -0700355 skb_push(skb, -skb_network_offset(skb));
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000356 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
357 if (extlen)
358 extlen += sizeof(*iph_ext);
359
360 err = -ENOMEM;
361 iph_base = ah_alloc_tmp(ahash, nfrags, IPV6HDR_BASELEN + extlen);
362 if (!iph_base)
363 goto out;
364
365 iph_ext = ah_tmp_ext(iph_base);
366 icv = ah_tmp_icv(ahash, iph_ext, extlen);
367 req = ah_tmp_req(ahash, icv);
368 sg = ah_req_sg(ahash, req);
369
370 ah = ip_auth_hdr(skb);
371 memset(ah->auth_data, 0, ahp->icv_trunc_len);
372
Herbert Xu007f0212007-10-09 13:25:59 -0700373 top_iph = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
375
Herbert Xu007f0212007-10-09 13:25:59 -0700376 nexthdr = *skb_mac_header(skb);
377 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379 /* When there are no extension headers, we only need to save the first
380 * 8 bytes of the base IP header.
381 */
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000382 memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 if (extlen) {
Masahide NAKAMURA59fbb3a62007-06-26 23:56:32 -0700385#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000386 memcpy(iph_ext, &top_iph->saddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900387#else
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000388 memcpy(iph_ext, &top_iph->daddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900389#endif
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700390 err = ipv6_clear_mutable_options(top_iph,
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000391 extlen - sizeof(*iph_ext) +
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700392 sizeof(*top_iph),
393 XFRM_POLICY_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000395 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 }
397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 ah->nexthdr = nexthdr;
399
400 top_iph->priority = 0;
401 top_iph->flow_lbl[0] = 0;
402 top_iph->flow_lbl[1] = 0;
403 top_iph->flow_lbl[2] = 0;
404 top_iph->hop_limit = 0;
405
Herbert Xu87bdc482007-10-10 15:45:25 -0700406 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
408 ah->reserved = 0;
409 ah->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000410 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Herbert Xub7c65382007-10-09 13:33:35 -0700411
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000412 sg_init_table(sg, nfrags);
413 skb_to_sgvec(skb, sg, 0, skb->len);
Herbert Xub7c65382007-10-09 13:33:35 -0700414
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000415 ahash_request_set_crypt(req, sg, icv, skb->len);
416 ahash_request_set_callback(req, 0, ah6_output_done, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000418 AH_SKB_CB(skb)->tmp = iph_base;
419
420 err = crypto_ahash_digest(req);
421 if (err) {
422 if (err == -EINPROGRESS)
423 goto out;
424
425 if (err == -EBUSY)
426 err = NET_XMIT_DROP;
427 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 }
429
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000430 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
431 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
432
433 if (extlen) {
434#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
435 memcpy(&top_iph->saddr, iph_ext, extlen);
436#else
437 memcpy(&top_iph->daddr, iph_ext, extlen);
438#endif
439 }
440
441out_free:
442 kfree(iph_base);
443out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return err;
445}
446
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000447static void ah6_input_done(struct crypto_async_request *base, int err)
448{
449 u8 *auth_data;
450 u8 *icv;
451 u8 *work_iph;
452 struct sk_buff *skb = base->data;
453 struct xfrm_state *x = xfrm_input_state(skb);
454 struct ah_data *ahp = x->data;
455 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
456 int hdr_len = skb_network_header_len(skb);
457 int ah_hlen = (ah->hdrlen + 2) << 2;
458
459 work_iph = AH_SKB_CB(skb)->tmp;
460 auth_data = ah_tmp_auth(work_iph, hdr_len);
461 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
462
463 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
464 if (err)
465 goto out;
466
Nick Bowlerb7ea81a2011-11-08 12:12:45 +0000467 err = ah->nexthdr;
468
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000469 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);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000473out:
474 kfree(AH_SKB_CB(skb)->tmp);
475 xfrm_input_resume(skb, err);
476}
477
478
479
Herbert Xue6956332006-04-01 00:52:46 -0800480static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481{
482 /*
483 * Before process AH
484 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
485 * |<-------------->| hdr_len
486 *
487 * To erase AH:
488 * Keeping copy of cleared headers. After AH processing,
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700489 * Moving the pointer of skb->network_header by using skb_pull as long
490 * as AH header length. Then copy back the copy as long as hdr_len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 * If destination header following AH exists, copy it into after [Ext2].
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900492 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
494 * There is offset of AH before IPv6 header after the process.
495 */
496
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000497 u8 *auth_data;
498 u8 *icv;
499 u8 *work_iph;
500 struct sk_buff *trailer;
501 struct crypto_ahash *ahash;
502 struct ahash_request *req;
503 struct scatterlist *sg;
Herbert Xu87bdc482007-10-10 15:45:25 -0700504 struct ip_auth_hdr *ah;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700505 struct ipv6hdr *ip6h;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 struct ah_data *ahp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 u16 hdr_len;
508 u16 ah_hlen;
509 int nexthdr;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000510 int nfrags;
511 int err = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512
513 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
514 goto out;
515
516 /* We are going to _remove_ AH header to keep sockets happy,
517 * so... Later this can change. */
518 if (skb_cloned(skb) &&
519 pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
520 goto out;
521
Herbert Xu7aa68cb2007-10-17 21:30:07 -0700522 skb->ip_summed = CHECKSUM_NONE;
523
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000524 hdr_len = skb_network_header_len(skb);
Herbert Xu87bdc482007-10-10 15:45:25 -0700525 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 ahp = x->data;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000527 ahash = ahp->ahash;
528
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 nexthdr = ah->nexthdr;
530 ah_hlen = (ah->hdrlen + 2) << 2;
531
Herbert Xu87bdc482007-10-10 15:45:25 -0700532 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
533 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900534 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535
536 if (!pskb_may_pull(skb, ah_hlen))
537 goto out;
538
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000539
540 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
541 goto out;
542 nfrags = err;
543
Dang Hongwu4b0ef1f22011-01-11 07:13:33 +0000544 ah = (struct ip_auth_hdr *)skb->data;
545 ip6h = ipv6_hdr(skb);
546
547 skb_push(skb, hdr_len);
548
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000549 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
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700562 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000563 goto out_free;
564
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700565 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000571 sg_init_table(sg, nfrags);
572 skb_to_sgvec(skb, sg, 0, skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000574 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
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000584 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800586
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000587 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800588 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000589 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700591 skb->network_header += ah_hlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000592 memcpy(skb_network_header(skb), work_iph, hdr_len);
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700593 skb->transport_header = skb->network_header;
Herbert Xu31a4ab92006-05-27 23:06:13 -0700594 __skb_pull(skb, ah_hlen + hdr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000596 err = nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000598out_free:
599 kfree(work_iph);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000601 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
603
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900604static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
Brian Haleyd5fdd6b2009-06-23 04:31:07 -0700605 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800607 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
609 struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset);
610 struct xfrm_state *x;
611
612 if (type != ICMPV6_DEST_UNREACH &&
613 type != ICMPV6_PKT_TOOBIG)
614 return;
615
Jamal Hadi Salimbd557752010-02-22 16:20:22 -0800616 x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 if (!x)
618 return;
619
Harvey Harrison5b095d9892008-10-29 12:52:50 -0700620 NETDEBUG(KERN_DEBUG "pmtu discovery on SA AH/%08x/%pI6\n",
Harvey Harrison0c6ce782008-10-28 16:09:23 -0700621 ntohl(ah->spi), &iph->daddr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
623 xfrm_state_put(x);
624}
625
Herbert Xu72cb6962005-06-20 13:18:08 -0700626static int ah6_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627{
628 struct ah_data *ahp = NULL;
629 struct xfrm_algo_desc *aalg_desc;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000630 struct crypto_ahash *ahash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
632 if (!x->aalg)
633 goto error;
634
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 if (x->encap)
636 goto error;
637
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800638 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 if (ahp == NULL)
640 return -ENOMEM;
641
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000642 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
643 if (IS_ERR(ahash))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000645
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000646 ahp->ahash = ahash;
647 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
Herbert Xubc31d3b2007-10-08 17:14:34 -0700648 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000649 goto error;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900650
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 /*
652 * Lookup the algorithm description maintained by xfrm_algo,
653 * verify crypto transform properties, and store information
654 * we need for AH processing. This lookup cannot fail here
Herbert Xu07d4ee52006-08-20 14:24:50 +1000655 * after a successful crypto_alloc_hash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 */
657 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
658 BUG_ON(!aalg_desc);
659
660 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000661 crypto_ahash_digestsize(ahash)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 printk(KERN_INFO "AH: %s digestsize %u != %hu\n",
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000663 x->aalg->alg_name, crypto_ahash_digestsize(ahash),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 aalg_desc->uinfo.auth.icv_fullbits/8);
665 goto error;
666 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900667
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
Martin Willi8f8a0882009-11-25 00:29:53 +0000669 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900670
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900672
Herbert Xu87bdc482007-10-10 15:45:25 -0700673 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
674 ahp->icv_trunc_len);
Herbert Xuca681452007-10-17 21:35:15 -0700675 switch (x->props.mode) {
676 case XFRM_MODE_BEET:
677 case XFRM_MODE_TRANSPORT:
678 break;
679 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700681 break;
Herbert Xuca681452007-10-17 21:35:15 -0700682 default:
683 goto error;
684 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 x->data = ahp;
686
687 return 0;
688
689error:
690 if (ahp) {
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000691 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 kfree(ahp);
693 }
694 return -EINVAL;
695}
696
697static void ah6_destroy(struct xfrm_state *x)
698{
699 struct ah_data *ahp = x->data;
700
701 if (!ahp)
702 return;
703
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000704 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 kfree(ahp);
706}
707
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800708static const struct xfrm_type ah6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709{
710 .description = "AH6",
711 .owner = THIS_MODULE,
712 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700713 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 .init_state = ah6_init_state,
715 .destructor = ah6_destroy,
716 .input = ah6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700717 .output = ah6_output,
718 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719};
720
Alexey Dobriyan41135cc2009-09-14 12:22:28 +0000721static const struct inet6_protocol ah6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 .handler = xfrm6_rcv,
723 .err_handler = ah6_err,
724 .flags = INET6_PROTO_NOPOLICY,
725};
726
727static int __init ah6_init(void)
728{
729 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
730 printk(KERN_INFO "ipv6 ah init: can't add xfrm type\n");
731 return -EAGAIN;
732 }
733
734 if (inet6_add_protocol(&ah6_protocol, IPPROTO_AH) < 0) {
735 printk(KERN_INFO "ipv6 ah init: can't add protocol\n");
736 xfrm_unregister_type(&ah6_type, AF_INET6);
737 return -EAGAIN;
738 }
739
740 return 0;
741}
742
743static void __exit ah6_fini(void)
744{
745 if (inet6_del_protocol(&ah6_protocol, IPPROTO_AH) < 0)
746 printk(KERN_INFO "ipv6 ah close: can't remove protocol\n");
747
748 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
749 printk(KERN_INFO "ipv6 ah close: can't remove xfrm type\n");
750
751}
752
753module_init(ah6_init);
754module_exit(ah6_fini);
755
756MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700757MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);