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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
Jeff Kirshera99421d2013-12-06 09:13:39 -080015 * along with this program; if not, see <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 *
17 * Authors
18 *
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090019 * Mitsuru KANDA @USAGI : IPv6 Support
Linus Torvalds1da177e2005-04-16 15:20:36 -070020 * Kazunori MIYAZAWA @USAGI :
21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +090022 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 * This file is derived from net/ipv4/ah.c.
24 */
25
Joe Perchesf3213832012-05-15 14:11:53 +000026#define pr_fmt(fmt) "IPv6: " fmt
27
Steffen Klassert8631e9b2009-10-07 22:49:01 +000028#include <crypto/hash.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090030#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <net/ip.h>
32#include <net/ah.h>
33#include <linux/crypto.h>
34#include <linux/pfkeyv2.h>
35#include <linux/string.h>
Steffen Klassert8631e9b2009-10-07 22:49:01 +000036#include <linux/scatterlist.h>
David S. Miller81aded22012-06-15 14:54:11 -070037#include <net/ip6_route.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <net/icmp.h>
39#include <net/ipv6.h>
Arnaldo Carvalho de Melo14c85022005-12-27 02:43:12 -020040#include <net/protocol.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <net/xfrm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Steffen Klassert8631e9b2009-10-07 22:49:01 +000043#define IPV6HDR_BASELEN 8
44
45struct tmp_ext {
Amerigo Wang07a93622012-10-29 16:23:10 +000046#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +000047 struct in6_addr saddr;
48#endif
49 struct in6_addr daddr;
50 char hdrs[0];
51};
52
53struct ah_skb_cb {
54 struct xfrm_skb_cb xfrm;
55 void *tmp;
56};
57
58#define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0]))
59
60static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags,
61 unsigned int size)
62{
63 unsigned int len;
64
65 len = size + crypto_ahash_digestsize(ahash) +
66 (crypto_ahash_alignmask(ahash) &
67 ~(crypto_tfm_ctx_alignment() - 1));
68
69 len = ALIGN(len, crypto_tfm_ctx_alignment());
70
71 len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash);
72 len = ALIGN(len, __alignof__(struct scatterlist));
73
74 len += sizeof(struct scatterlist) * nfrags;
75
76 return kmalloc(len, GFP_ATOMIC);
77}
78
79static inline struct tmp_ext *ah_tmp_ext(void *base)
80{
81 return base + IPV6HDR_BASELEN;
82}
83
84static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset)
85{
86 return tmp + offset;
87}
88
89static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp,
90 unsigned int offset)
91{
92 return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1);
93}
94
95static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash,
96 u8 *icv)
97{
98 struct ahash_request *req;
99
100 req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash),
101 crypto_tfm_ctx_alignment());
102
103 ahash_request_set_tfm(req, ahash);
104
105 return req;
106}
107
108static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash,
109 struct ahash_request *req)
110{
111 return (void *)ALIGN((unsigned long)(req + 1) +
112 crypto_ahash_reqsize(ahash),
113 __alignof__(struct scatterlist));
114}
115
Eric Dumazeta50feda2012-05-18 18:57:34 +0000116static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117{
118 u8 *opt = (u8 *)opthdr;
119 int len = ipv6_optlen(opthdr);
120 int off = 0;
121 int optlen = 0;
122
123 off += 2;
124 len -= 2;
125
126 while (len > 0) {
127
128 switch (opt[off]) {
129
Eldad Zack1de5a712012-05-17 06:00:25 +0000130 case IPV6_TLV_PAD1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 optlen = 1;
132 break;
133 default:
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900134 if (len < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 goto bad;
136 optlen = opt[off+1]+2;
137 if (len < optlen)
138 goto bad;
139 if (opt[off] & 0x20)
140 memset(&opt[off+2], 0, opt[off+1]);
141 break;
142 }
143
144 off += optlen;
145 len -= optlen;
146 }
147 if (len == 0)
Eric Dumazeta50feda2012-05-18 18:57:34 +0000148 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150bad:
Eric Dumazeta50feda2012-05-18 18:57:34 +0000151 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Amerigo Wang07a93622012-10-29 16:23:10 +0000154#if IS_ENABLED(CONFIG_IPV6_MIP6)
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700155/**
156 * ipv6_rearrange_destopt - rearrange IPv6 destination options header
157 * @iph: IPv6 header
158 * @destopt: destionation options header
159 */
160static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
161{
162 u8 *opt = (u8 *)destopt;
163 int len = ipv6_optlen(destopt);
164 int off = 0;
165 int optlen = 0;
166
167 off += 2;
168 len -= 2;
169
170 while (len > 0) {
171
172 switch (opt[off]) {
173
Eldad Zack1de5a712012-05-17 06:00:25 +0000174 case IPV6_TLV_PAD1:
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700175 optlen = 1;
176 break;
177 default:
178 if (len < 2)
179 goto bad;
180 optlen = opt[off+1]+2;
181 if (len < optlen)
182 goto bad;
183
184 /* Rearrange the source address in @iph and the
185 * addresses in home address option for final source.
186 * See 11.3.2 of RFC 3775 for details.
187 */
188 if (opt[off] == IPV6_TLV_HAO) {
189 struct in6_addr final_addr;
190 struct ipv6_destopt_hao *hao;
191
192 hao = (struct ipv6_destopt_hao *)&opt[off];
193 if (hao->length != sizeof(hao->addr)) {
Joe Perchese87cc472012-05-13 21:56:26 +0000194 net_warn_ratelimited("destopt hao: invalid header length: %u\n",
195 hao->length);
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700196 goto bad;
197 }
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000198 final_addr = hao->addr;
199 hao->addr = iph->saddr;
200 iph->saddr = final_addr;
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700201 }
202 break;
203 }
204
205 off += optlen;
206 len -= optlen;
207 }
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900208 /* Note: ok if len == 0 */
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700209bad:
210 return;
211}
Masahide NAKAMURA136ebf02007-06-26 23:51:41 -0700212#else
213static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {}
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700214#endif
215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216/**
217 * ipv6_rearrange_rthdr - rearrange IPv6 routing header
218 * @iph: IPv6 header
219 * @rthdr: routing header
220 *
221 * Rearrange the destination address in @iph and the addresses in @rthdr
222 * so that they appear in the order they will at the final destination.
223 * See Appendix A2 of RFC 2402 for details.
224 */
225static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
226{
227 int segments, segments_left;
228 struct in6_addr *addrs;
229 struct in6_addr final_addr;
230
231 segments_left = rthdr->segments_left;
232 if (segments_left == 0)
233 return;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900234 rthdr->segments_left = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235
236 /* The value of rthdr->hdrlen has been verified either by the system
237 * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming
238 * packets. So we can assume that it is even and that segments is
239 * greater than or equal to segments_left.
240 *
241 * For the same reason we can assume that this option is of type 0.
242 */
243 segments = rthdr->hdrlen >> 1;
244
245 addrs = ((struct rt0_hdr *)rthdr)->addr;
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000246 final_addr = addrs[segments - 1];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 addrs += segments - segments_left;
249 memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs));
250
Alexey Dobriyan4e3fd7a2011-11-21 03:39:03 +0000251 addrs[0] = iph->daddr;
252 iph->daddr = final_addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253}
254
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700255static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256{
257 union {
258 struct ipv6hdr *iph;
259 struct ipv6_opt_hdr *opth;
260 struct ipv6_rt_hdr *rth;
261 char *raw;
262 } exthdr = { .iph = iph };
263 char *end = exthdr.raw + len;
264 int nexthdr = iph->nexthdr;
265
266 exthdr.iph++;
267
268 while (exthdr.raw < end) {
269 switch (nexthdr) {
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700270 case NEXTHDR_DEST:
271 if (dir == XFRM_POLICY_OUT)
272 ipv6_rearrange_destopt(iph, exthdr.opth);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900273 case NEXTHDR_HOP:
274 if (!zero_out_mutable_opts(exthdr.opth)) {
275 LIMIT_NETDEBUG(
276 KERN_WARNING "overrun %sopts\n",
277 nexthdr == NEXTHDR_HOP ?
278 "hop" : "dest");
279 return -EINVAL;
280 }
281 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 case NEXTHDR_ROUTING:
284 ipv6_rearrange_rthdr(iph, exthdr.rth);
285 break;
286
287 default :
288 return 0;
289 }
290
291 nexthdr = exthdr.opth->nexthdr;
292 exthdr.raw += ipv6_optlen(exthdr.opth);
293 }
294
295 return 0;
296}
297
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000298static void ah6_output_done(struct crypto_async_request *base, int err)
299{
300 int extlen;
301 u8 *iph_base;
302 u8 *icv;
303 struct sk_buff *skb = base->data;
304 struct xfrm_state *x = skb_dst(skb)->xfrm;
305 struct ah_data *ahp = x->data;
306 struct ipv6hdr *top_iph = ipv6_hdr(skb);
307 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
308 struct tmp_ext *iph_ext;
309
310 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
311 if (extlen)
312 extlen += sizeof(*iph_ext);
313
314 iph_base = AH_SKB_CB(skb)->tmp;
315 iph_ext = ah_tmp_ext(iph_base);
316 icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen);
317
318 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
319 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
320
321 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000322#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000323 memcpy(&top_iph->saddr, iph_ext, extlen);
324#else
325 memcpy(&top_iph->daddr, iph_ext, extlen);
326#endif
327 }
328
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000329 kfree(AH_SKB_CB(skb)->tmp);
330 xfrm_output_resume(skb, err);
331}
332
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
334{
335 int err;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000336 int nfrags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 int extlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000338 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 struct ipv6hdr *top_iph;
346 struct ip_auth_hdr *ah;
347 struct ah_data *ahp;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000348 struct tmp_ext *iph_ext;
Fan Du26dd70c2014-01-18 09:54:26 +0800349 int seqhi_len = 0;
350 __be32 *seqhi;
351 int sglists = 0;
352 struct scatterlist *seqhisg;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000353
354 ahp = x->data;
355 ahash = ahp->ahash;
356
357 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
358 goto out;
359 nfrags = err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
Herbert Xu7b277b12007-10-10 15:44:06 -0700361 skb_push(skb, -skb_network_offset(skb));
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000362 extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr);
363 if (extlen)
364 extlen += sizeof(*iph_ext);
365
Fan Du26dd70c2014-01-18 09:54:26 +0800366 if (x->props.flags & XFRM_STATE_ESN) {
367 sglists = 1;
368 seqhi_len = sizeof(*seqhi);
369 }
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000370 err = -ENOMEM;
Fan Du26dd70c2014-01-18 09:54:26 +0800371 iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN +
372 extlen + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000373 if (!iph_base)
374 goto out;
375
376 iph_ext = ah_tmp_ext(iph_base);
Fan Du26dd70c2014-01-18 09:54:26 +0800377 seqhi = (__be32 *)((char *)iph_ext + extlen);
378 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000379 req = ah_tmp_req(ahash, icv);
380 sg = ah_req_sg(ahash, req);
Fan Du26dd70c2014-01-18 09:54:26 +0800381 seqhisg = sg + nfrags;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000382
383 ah = ip_auth_hdr(skb);
384 memset(ah->auth_data, 0, ahp->icv_trunc_len);
385
Herbert Xu007f0212007-10-09 13:25:59 -0700386 top_iph = ipv6_hdr(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 top_iph->payload_len = htons(skb->len - sizeof(*top_iph));
388
Herbert Xu007f0212007-10-09 13:25:59 -0700389 nexthdr = *skb_mac_header(skb);
390 *skb_mac_header(skb) = IPPROTO_AH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 /* When there are no extension headers, we only need to save the first
393 * 8 bytes of the base IP header.
394 */
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000395 memcpy(iph_base, top_iph, IPV6HDR_BASELEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000398#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000399 memcpy(iph_ext, &top_iph->saddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900400#else
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000401 memcpy(iph_ext, &top_iph->daddr, extlen);
YOSHIFUJI Hideakie731c242006-08-24 23:18:12 +0900402#endif
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700403 err = ipv6_clear_mutable_options(top_iph,
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000404 extlen - sizeof(*iph_ext) +
Masahide NAKAMURA27637df2006-08-23 19:29:47 -0700405 sizeof(*top_iph),
406 XFRM_POLICY_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000408 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 }
410
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 ah->nexthdr = nexthdr;
412
413 top_iph->priority = 0;
414 top_iph->flow_lbl[0] = 0;
415 top_iph->flow_lbl[1] = 0;
416 top_iph->flow_lbl[2] = 0;
417 top_iph->hop_limit = 0;
418
Herbert Xu87bdc482007-10-10 15:45:25 -0700419 ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420
421 ah->reserved = 0;
422 ah->spi = x->id.spi;
Steffen Klassert1ce36442011-03-08 00:06:31 +0000423 ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
Herbert Xub7c65382007-10-09 13:33:35 -0700424
Fan Du26dd70c2014-01-18 09:54:26 +0800425 sg_init_table(sg, nfrags + sglists);
426 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
Herbert Xub7c65382007-10-09 13:33:35 -0700427
Fan Du26dd70c2014-01-18 09:54:26 +0800428 if (x->props.flags & XFRM_STATE_ESN) {
429 /* Attach seqhi sg right after packet payload */
430 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
431 sg_set_buf(seqhisg, seqhi, seqhi_len);
432 }
433 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000434 ahash_request_set_callback(req, 0, ah6_output_done, skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000436 AH_SKB_CB(skb)->tmp = iph_base;
437
438 err = crypto_ahash_digest(req);
439 if (err) {
440 if (err == -EINPROGRESS)
441 goto out;
442
443 if (err == -EBUSY)
444 err = NET_XMIT_DROP;
445 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 }
447
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000448 memcpy(ah->auth_data, icv, ahp->icv_trunc_len);
449 memcpy(top_iph, iph_base, IPV6HDR_BASELEN);
450
451 if (extlen) {
Amerigo Wang07a93622012-10-29 16:23:10 +0000452#if IS_ENABLED(CONFIG_IPV6_MIP6)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000453 memcpy(&top_iph->saddr, iph_ext, extlen);
454#else
455 memcpy(&top_iph->daddr, iph_ext, extlen);
456#endif
457 }
458
459out_free:
460 kfree(iph_base);
461out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 return err;
463}
464
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000465static void ah6_input_done(struct crypto_async_request *base, int err)
466{
467 u8 *auth_data;
468 u8 *icv;
469 u8 *work_iph;
470 struct sk_buff *skb = base->data;
471 struct xfrm_state *x = xfrm_input_state(skb);
472 struct ah_data *ahp = x->data;
473 struct ip_auth_hdr *ah = ip_auth_hdr(skb);
474 int hdr_len = skb_network_header_len(skb);
475 int ah_hlen = (ah->hdrlen + 2) << 2;
476
477 work_iph = AH_SKB_CB(skb)->tmp;
478 auth_data = ah_tmp_auth(work_iph, hdr_len);
479 icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len);
480
481 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
482 if (err)
483 goto out;
484
Nick Bowlerb7ea81a2011-11-08 12:12:45 +0000485 err = ah->nexthdr;
486
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000487 skb->network_header += ah_hlen;
488 memcpy(skb_network_header(skb), work_iph, hdr_len);
489 __skb_pull(skb, ah_hlen + hdr_len);
Li RongQinga9403f82013-01-08 15:41:12 +0800490 if (x->props.mode == XFRM_MODE_TUNNEL)
491 skb_reset_transport_header(skb);
492 else
493 skb_set_transport_header(skb, -hdr_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000494out:
495 kfree(AH_SKB_CB(skb)->tmp);
496 xfrm_input_resume(skb, err);
497}
498
499
500
Herbert Xue6956332006-04-01 00:52:46 -0800501static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502{
503 /*
504 * Before process AH
505 * [IPv6][Ext1][Ext2][AH][Dest][Payload]
506 * |<-------------->| hdr_len
507 *
508 * To erase AH:
509 * Keeping copy of cleared headers. After AH processing,
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700510 * Moving the pointer of skb->network_header by using skb_pull as long
511 * as AH header length. Then copy back the copy as long as hdr_len
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 * If destination header following AH exists, copy it into after [Ext2].
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900513 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 * |<>|[IPv6][Ext1][Ext2][Dest][Payload]
515 * There is offset of AH before IPv6 header after the process.
516 */
517
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000518 u8 *auth_data;
519 u8 *icv;
520 u8 *work_iph;
521 struct sk_buff *trailer;
522 struct crypto_ahash *ahash;
523 struct ahash_request *req;
524 struct scatterlist *sg;
Herbert Xu87bdc482007-10-10 15:45:25 -0700525 struct ip_auth_hdr *ah;
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700526 struct ipv6hdr *ip6h;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 struct ah_data *ahp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 u16 hdr_len;
529 u16 ah_hlen;
530 int nexthdr;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000531 int nfrags;
532 int err = -ENOMEM;
Fan Du8d6da6f2014-01-18 09:54:27 +0800533 int seqhi_len = 0;
534 __be32 *seqhi;
535 int sglists = 0;
536 struct scatterlist *seqhisg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537
538 if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr)))
539 goto out;
540
541 /* We are going to _remove_ AH header to keep sockets happy,
542 * so... Later this can change. */
Pravin B Shelar14bbd6a2013-02-14 09:44:49 +0000543 if (skb_unclone(skb, GFP_ATOMIC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 goto out;
545
Herbert Xu7aa68cb2007-10-17 21:30:07 -0700546 skb->ip_summed = CHECKSUM_NONE;
547
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000548 hdr_len = skb_network_header_len(skb);
Herbert Xu87bdc482007-10-10 15:45:25 -0700549 ah = (struct ip_auth_hdr *)skb->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 ahp = x->data;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000551 ahash = ahp->ahash;
552
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 nexthdr = ah->nexthdr;
554 ah_hlen = (ah->hdrlen + 2) << 2;
555
Herbert Xu87bdc482007-10-10 15:45:25 -0700556 if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) &&
557 ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len))
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900558 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 if (!pskb_may_pull(skb, ah_hlen))
561 goto out;
562
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000563
564 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
565 goto out;
566 nfrags = err;
567
Dang Hongwu4b0ef1f22011-01-11 07:13:33 +0000568 ah = (struct ip_auth_hdr *)skb->data;
569 ip6h = ipv6_hdr(skb);
570
571 skb_push(skb, hdr_len);
572
Fan Du8d6da6f2014-01-18 09:54:27 +0800573 if (x->props.flags & XFRM_STATE_ESN) {
574 sglists = 1;
575 seqhi_len = sizeof(*seqhi);
576 }
577
578 work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
579 ahp->icv_trunc_len + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000580 if (!work_iph)
581 goto out;
582
Fan Du8d6da6f2014-01-18 09:54:27 +0800583 auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
584 seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);
585 icv = ah_tmp_icv(ahash, seqhi, seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000586 req = ah_tmp_req(ahash, icv);
587 sg = ah_req_sg(ahash, req);
Fan Du8d6da6f2014-01-18 09:54:27 +0800588 seqhisg = sg + nfrags;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000589
590 memcpy(work_iph, ip6h, hdr_len);
591 memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len);
592 memset(ah->auth_data, 0, ahp->icv_trunc_len);
593
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700594 if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN))
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000595 goto out_free;
596
Arnaldo Carvalho de Melo0660e032007-04-25 17:54:47 -0700597 ip6h->priority = 0;
598 ip6h->flow_lbl[0] = 0;
599 ip6h->flow_lbl[1] = 0;
600 ip6h->flow_lbl[2] = 0;
601 ip6h->hop_limit = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
Fan Du8d6da6f2014-01-18 09:54:27 +0800603 sg_init_table(sg, nfrags + sglists);
604 skb_to_sgvec_nomark(skb, sg, 0, skb->len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
Fan Du8d6da6f2014-01-18 09:54:27 +0800606 if (x->props.flags & XFRM_STATE_ESN) {
607 /* Attach seqhi sg right after packet payload */
608 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
609 sg_set_buf(seqhisg, seqhi, seqhi_len);
610 }
611
612 ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len);
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000613 ahash_request_set_callback(req, 0, ah6_input_done, skb);
614
615 AH_SKB_CB(skb)->tmp = work_iph;
616
617 err = crypto_ahash_digest(req);
618 if (err) {
619 if (err == -EINPROGRESS)
620 goto out;
621
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000622 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 }
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800624
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000625 err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0;
Herbert Xu0ebea8e2007-11-13 21:45:58 -0800626 if (err)
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000627 goto out_free;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
Arnaldo Carvalho de Melob0e380b2007-04-10 21:21:55 -0700629 skb->network_header += ah_hlen;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000630 memcpy(skb_network_header(skb), work_iph, hdr_len);
Herbert Xu31a4ab92006-05-27 23:06:13 -0700631 __skb_pull(skb, ah_hlen + hdr_len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
Li RongQinga9403f82013-01-08 15:41:12 +0800633 if (x->props.mode == XFRM_MODE_TUNNEL)
634 skb_reset_transport_header(skb);
635 else
636 skb_set_transport_header(skb, -hdr_len);
637
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000638 err = nexthdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000640out_free:
641 kfree(work_iph);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642out:
Herbert Xu07d4ee52006-08-20 14:24:50 +1000643 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644}
645
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100646static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
647 u8 type, u8 code, int offset, __be32 info)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648{
Alexey Dobriyan4fb236b2008-11-25 17:59:27 -0800649 struct net *net = dev_net(skb->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
651 struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset);
652 struct xfrm_state *x;
653
Steffen Klassertb3b2b9e2013-09-10 13:43:09 +0200654 if (type != ICMPV6_PKT_TOOBIG &&
David S. Millerec18d9a2012-07-12 00:25:15 -0700655 type != NDISC_REDIRECT)
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100656 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Jamal Hadi Salimbd557752010-02-22 16:20:22 -0800658 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 -0700659 if (!x)
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100660 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
David S. Millerec18d9a2012-07-12 00:25:15 -0700662 if (type == NDISC_REDIRECT)
Duan Jiongb55b76b2013-09-04 19:44:21 +0800663 ip6_redirect(skb, net, skb->dev->ifindex, 0);
David S. Millerec18d9a2012-07-12 00:25:15 -0700664 else
665 ip6_update_pmtu(skb, net, info, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 xfrm_state_put(x);
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100667
668 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669}
670
Herbert Xu72cb6962005-06-20 13:18:08 -0700671static int ah6_init_state(struct xfrm_state *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672{
673 struct ah_data *ahp = NULL;
674 struct xfrm_algo_desc *aalg_desc;
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000675 struct crypto_ahash *ahash;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 if (!x->aalg)
678 goto error;
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 if (x->encap)
681 goto error;
682
Ingo Oeser0c600ed2006-03-20 23:01:32 -0800683 ahp = kzalloc(sizeof(*ahp), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 if (ahp == NULL)
685 return -ENOMEM;
686
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000687 ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0);
688 if (IS_ERR(ahash))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 goto error;
Herbert Xu07d4ee52006-08-20 14:24:50 +1000690
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000691 ahp->ahash = ahash;
692 if (crypto_ahash_setkey(ahash, x->aalg->alg_key,
Herbert Xubc31d3b2007-10-08 17:14:34 -0700693 (x->aalg->alg_key_len + 7) / 8))
Herbert Xu07d4ee52006-08-20 14:24:50 +1000694 goto error;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 /*
697 * Lookup the algorithm description maintained by xfrm_algo,
698 * verify crypto transform properties, and store information
699 * we need for AH processing. This lookup cannot fail here
Herbert Xu07d4ee52006-08-20 14:24:50 +1000700 * after a successful crypto_alloc_hash().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 */
702 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
703 BUG_ON(!aalg_desc);
704
705 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000706 crypto_ahash_digestsize(ahash)) {
Joe Perchesf3213832012-05-15 14:11:53 +0000707 pr_info("AH: %s digestsize %u != %hu\n",
708 x->aalg->alg_name, crypto_ahash_digestsize(ahash),
709 aalg_desc->uinfo.auth.icv_fullbits/8);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 goto error;
711 }
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8;
Martin Willi8f8a0882009-11-25 00:29:53 +0000714 ahp->icv_trunc_len = x->aalg->alg_trunc_len/8;
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN);
YOSHIFUJI Hideaki1ab14572007-02-09 23:24:49 +0900717
Herbert Xu87bdc482007-10-10 15:45:25 -0700718 x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) +
719 ahp->icv_trunc_len);
Herbert Xuca681452007-10-17 21:35:15 -0700720 switch (x->props.mode) {
721 case XFRM_MODE_BEET:
722 case XFRM_MODE_TRANSPORT:
723 break;
724 case XFRM_MODE_TUNNEL:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 x->props.header_len += sizeof(struct ipv6hdr);
Masahide NAKAMURAea2c47b2007-10-22 02:30:15 -0700726 break;
Herbert Xuca681452007-10-17 21:35:15 -0700727 default:
728 goto error;
729 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 x->data = ahp;
731
732 return 0;
733
734error:
735 if (ahp) {
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000736 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 kfree(ahp);
738 }
739 return -EINVAL;
740}
741
742static void ah6_destroy(struct xfrm_state *x)
743{
744 struct ah_data *ahp = x->data;
745
746 if (!ahp)
747 return;
748
Steffen Klassert8631e9b2009-10-07 22:49:01 +0000749 crypto_free_ahash(ahp->ahash);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 kfree(ahp);
751}
752
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100753static int ah6_rcv_cb(struct sk_buff *skb, int err)
754{
755 return 0;
756}
757
Eric Dumazet533cb5b2008-01-30 19:11:50 -0800758static const struct xfrm_type ah6_type =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759{
760 .description = "AH6",
761 .owner = THIS_MODULE,
762 .proto = IPPROTO_AH,
Herbert Xu436a0a42007-10-08 17:25:53 -0700763 .flags = XFRM_TYPE_REPLAY_PROT,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 .init_state = ah6_init_state,
765 .destructor = ah6_destroy,
766 .input = ah6_input,
Masahide NAKAMURAaee5adb2006-08-23 17:57:28 -0700767 .output = ah6_output,
768 .hdr_offset = xfrm6_find_1stfragopt,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769};
770
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100771static struct xfrm6_protocol ah6_protocol = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 .handler = xfrm6_rcv,
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100773 .cb_handler = ah6_rcv_cb,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 .err_handler = ah6_err,
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100775 .priority = 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776};
777
778static int __init ah6_init(void)
779{
780 if (xfrm_register_type(&ah6_type, AF_INET6) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000781 pr_info("%s: can't add xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 return -EAGAIN;
783 }
784
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100785 if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) {
Joe Perchesf3213832012-05-15 14:11:53 +0000786 pr_info("%s: can't add protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 xfrm_unregister_type(&ah6_type, AF_INET6);
788 return -EAGAIN;
789 }
790
791 return 0;
792}
793
794static void __exit ah6_fini(void)
795{
Steffen Klasserte924d2d2014-03-14 07:28:07 +0100796 if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000797 pr_info("%s: can't remove protocol\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798
799 if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0)
Joe Perchesf3213832012-05-15 14:11:53 +0000800 pr_info("%s: can't remove xfrm type\n", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802}
803
804module_init(ah6_init);
805module_exit(ah6_fini);
806
807MODULE_LICENSE("GPL");
Masahide NAKAMURAd3d6dd32007-06-26 23:57:49 -0700808MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH);