]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C)2002 USAGI/WIDE Project | |
1ab1457c | 3 | * |
1da177e4 LT |
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. | |
1ab1457c | 8 | * |
1da177e4 LT |
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. | |
1ab1457c | 13 | * |
1da177e4 | 14 | * You should have received a copy of the GNU General Public License |
a99421d9 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
1da177e4 LT |
16 | * |
17 | * Authors | |
18 | * | |
1ab1457c | 19 | * Mitsuru KANDA @USAGI : IPv6 Support |
67ba4152 IM |
20 | * Kazunori MIYAZAWA @USAGI : |
21 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
1ab1457c | 22 | * |
67ba4152 | 23 | * This file is derived from net/ipv4/ah.c. |
1da177e4 LT |
24 | */ |
25 | ||
f3213831 JP |
26 | #define pr_fmt(fmt) "IPv6: " fmt |
27 | ||
8631e9bd | 28 | #include <crypto/hash.h> |
1da177e4 | 29 | #include <linux/module.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
1da177e4 LT |
31 | #include <net/ip.h> |
32 | #include <net/ah.h> | |
33 | #include <linux/crypto.h> | |
34 | #include <linux/pfkeyv2.h> | |
35 | #include <linux/string.h> | |
8631e9bd | 36 | #include <linux/scatterlist.h> |
81aded24 | 37 | #include <net/ip6_route.h> |
1da177e4 LT |
38 | #include <net/icmp.h> |
39 | #include <net/ipv6.h> | |
14c85021 | 40 | #include <net/protocol.h> |
1da177e4 | 41 | #include <net/xfrm.h> |
1da177e4 | 42 | |
8631e9bd SK |
43 | #define IPV6HDR_BASELEN 8 |
44 | ||
45 | struct tmp_ext { | |
07a93626 | 46 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
47 | struct in6_addr saddr; |
48 | #endif | |
49 | struct in6_addr daddr; | |
50 | char hdrs[0]; | |
51 | }; | |
52 | ||
53 | struct 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 | ||
60 | static 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 | ||
79 | static inline struct tmp_ext *ah_tmp_ext(void *base) | |
80 | { | |
81 | return base + IPV6HDR_BASELEN; | |
82 | } | |
83 | ||
84 | static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) | |
85 | { | |
86 | return tmp + offset; | |
87 | } | |
88 | ||
89 | static 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 | ||
95 | static 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 | ||
108 | static 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 | ||
a50feda5 | 116 | static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) |
1da177e4 LT |
117 | { |
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 | ||
1de5a71c | 130 | case IPV6_TLV_PAD1: |
1da177e4 LT |
131 | optlen = 1; |
132 | break; | |
133 | default: | |
1ab1457c | 134 | if (len < 2) |
1da177e4 LT |
135 | 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) | |
a50feda5 | 148 | return true; |
1da177e4 LT |
149 | |
150 | bad: | |
a50feda5 | 151 | return false; |
1da177e4 LT |
152 | } |
153 | ||
07a93626 | 154 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
27637df9 MN |
155 | /** |
156 | * ipv6_rearrange_destopt - rearrange IPv6 destination options header | |
157 | * @iph: IPv6 header | |
158 | * @destopt: destionation options header | |
159 | */ | |
160 | static 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 | ||
1de5a71c | 174 | case IPV6_TLV_PAD1: |
27637df9 MN |
175 | 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)) { | |
e87cc472 JP |
194 | net_warn_ratelimited("destopt hao: invalid header length: %u\n", |
195 | hao->length); | |
27637df9 MN |
196 | goto bad; |
197 | } | |
4e3fd7a0 AD |
198 | final_addr = hao->addr; |
199 | hao->addr = iph->saddr; | |
200 | iph->saddr = final_addr; | |
27637df9 MN |
201 | } |
202 | break; | |
203 | } | |
204 | ||
205 | off += optlen; | |
206 | len -= optlen; | |
207 | } | |
e731c248 | 208 | /* Note: ok if len == 0 */ |
27637df9 MN |
209 | bad: |
210 | return; | |
211 | } | |
136ebf08 MN |
212 | #else |
213 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} | |
27637df9 MN |
214 | #endif |
215 | ||
1da177e4 LT |
216 | /** |
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 | */ | |
225 | static 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; | |
1ab1457c | 234 | rthdr->segments_left = 0; |
1da177e4 LT |
235 | |
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; | |
4e3fd7a0 | 246 | final_addr = addrs[segments - 1]; |
1da177e4 LT |
247 | |
248 | addrs += segments - segments_left; | |
249 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); | |
250 | ||
4e3fd7a0 AD |
251 | addrs[0] = iph->daddr; |
252 | iph->daddr = final_addr; | |
1da177e4 LT |
253 | } |
254 | ||
27637df9 | 255 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
1da177e4 LT |
256 | { |
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) { | |
27637df9 MN |
270 | case NEXTHDR_DEST: |
271 | if (dir == XFRM_POLICY_OUT) | |
272 | ipv6_rearrange_destopt(iph, exthdr.opth); | |
1da177e4 | 273 | case NEXTHDR_HOP: |
1da177e4 | 274 | if (!zero_out_mutable_opts(exthdr.opth)) { |
ba7a46f1 JP |
275 | net_dbg_ratelimited("overrun %sopts\n", |
276 | nexthdr == NEXTHDR_HOP ? | |
277 | "hop" : "dest"); | |
1da177e4 LT |
278 | return -EINVAL; |
279 | } | |
280 | break; | |
281 | ||
282 | case NEXTHDR_ROUTING: | |
283 | ipv6_rearrange_rthdr(iph, exthdr.rth); | |
284 | break; | |
285 | ||
67ba4152 | 286 | default: |
1da177e4 LT |
287 | return 0; |
288 | } | |
289 | ||
290 | nexthdr = exthdr.opth->nexthdr; | |
291 | exthdr.raw += ipv6_optlen(exthdr.opth); | |
292 | } | |
293 | ||
294 | return 0; | |
295 | } | |
296 | ||
8631e9bd SK |
297 | static void ah6_output_done(struct crypto_async_request *base, int err) |
298 | { | |
299 | int extlen; | |
300 | u8 *iph_base; | |
301 | u8 *icv; | |
302 | struct sk_buff *skb = base->data; | |
303 | struct xfrm_state *x = skb_dst(skb)->xfrm; | |
304 | struct ah_data *ahp = x->data; | |
305 | struct ipv6hdr *top_iph = ipv6_hdr(skb); | |
306 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
307 | struct tmp_ext *iph_ext; | |
308 | ||
309 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); | |
310 | if (extlen) | |
311 | extlen += sizeof(*iph_ext); | |
312 | ||
313 | iph_base = AH_SKB_CB(skb)->tmp; | |
314 | iph_ext = ah_tmp_ext(iph_base); | |
315 | icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); | |
316 | ||
317 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
318 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
319 | ||
320 | if (extlen) { | |
07a93626 | 321 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
322 | memcpy(&top_iph->saddr, iph_ext, extlen); |
323 | #else | |
324 | memcpy(&top_iph->daddr, iph_ext, extlen); | |
325 | #endif | |
326 | } | |
327 | ||
8631e9bd SK |
328 | kfree(AH_SKB_CB(skb)->tmp); |
329 | xfrm_output_resume(skb, err); | |
330 | } | |
331 | ||
1da177e4 LT |
332 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
333 | { | |
334 | int err; | |
8631e9bd | 335 | int nfrags; |
1da177e4 | 336 | int extlen; |
8631e9bd SK |
337 | u8 *iph_base; |
338 | u8 *icv; | |
339 | u8 nexthdr; | |
340 | struct sk_buff *trailer; | |
341 | struct crypto_ahash *ahash; | |
342 | struct ahash_request *req; | |
343 | struct scatterlist *sg; | |
1da177e4 LT |
344 | struct ipv6hdr *top_iph; |
345 | struct ip_auth_hdr *ah; | |
346 | struct ah_data *ahp; | |
8631e9bd | 347 | struct tmp_ext *iph_ext; |
26dd70c3 FD |
348 | int seqhi_len = 0; |
349 | __be32 *seqhi; | |
350 | int sglists = 0; | |
351 | struct scatterlist *seqhisg; | |
8631e9bd SK |
352 | |
353 | ahp = x->data; | |
354 | ahash = ahp->ahash; | |
355 | ||
356 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) | |
357 | goto out; | |
358 | nfrags = err; | |
1da177e4 | 359 | |
7b277b1a | 360 | skb_push(skb, -skb_network_offset(skb)); |
8631e9bd SK |
361 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
362 | if (extlen) | |
363 | extlen += sizeof(*iph_ext); | |
364 | ||
26dd70c3 FD |
365 | if (x->props.flags & XFRM_STATE_ESN) { |
366 | sglists = 1; | |
367 | seqhi_len = sizeof(*seqhi); | |
368 | } | |
8631e9bd | 369 | err = -ENOMEM; |
26dd70c3 FD |
370 | iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + |
371 | extlen + seqhi_len); | |
8631e9bd SK |
372 | if (!iph_base) |
373 | goto out; | |
374 | ||
375 | iph_ext = ah_tmp_ext(iph_base); | |
26dd70c3 FD |
376 | seqhi = (__be32 *)((char *)iph_ext + extlen); |
377 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
378 | req = ah_tmp_req(ahash, icv); |
379 | sg = ah_req_sg(ahash, req); | |
26dd70c3 | 380 | seqhisg = sg + nfrags; |
8631e9bd SK |
381 | |
382 | ah = ip_auth_hdr(skb); | |
383 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
384 | ||
007f0211 | 385 | top_iph = ipv6_hdr(skb); |
1da177e4 LT |
386 | top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); |
387 | ||
007f0211 HX |
388 | nexthdr = *skb_mac_header(skb); |
389 | *skb_mac_header(skb) = IPPROTO_AH; | |
1da177e4 LT |
390 | |
391 | /* When there are no extension headers, we only need to save the first | |
392 | * 8 bytes of the base IP header. | |
393 | */ | |
8631e9bd | 394 | memcpy(iph_base, top_iph, IPV6HDR_BASELEN); |
1da177e4 | 395 | |
1da177e4 | 396 | if (extlen) { |
07a93626 | 397 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 398 | memcpy(iph_ext, &top_iph->saddr, extlen); |
27637df9 | 399 | #else |
8631e9bd | 400 | memcpy(iph_ext, &top_iph->daddr, extlen); |
e731c248 | 401 | #endif |
1da177e4 | 402 | err = ipv6_clear_mutable_options(top_iph, |
8631e9bd | 403 | extlen - sizeof(*iph_ext) + |
e731c248 YH |
404 | sizeof(*top_iph), |
405 | XFRM_POLICY_OUT); | |
1da177e4 | 406 | if (err) |
8631e9bd | 407 | goto out_free; |
1da177e4 LT |
408 | } |
409 | ||
1da177e4 LT |
410 | ah->nexthdr = nexthdr; |
411 | ||
412 | top_iph->priority = 0; | |
413 | top_iph->flow_lbl[0] = 0; | |
414 | top_iph->flow_lbl[1] = 0; | |
415 | top_iph->flow_lbl[2] = 0; | |
416 | top_iph->hop_limit = 0; | |
417 | ||
87bdc48d | 418 | ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; |
1da177e4 LT |
419 | |
420 | ah->reserved = 0; | |
421 | ah->spi = x->id.spi; | |
1ce3644a | 422 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
b7c6538c | 423 | |
26dd70c3 FD |
424 | sg_init_table(sg, nfrags + sglists); |
425 | skb_to_sgvec_nomark(skb, sg, 0, skb->len); | |
1da177e4 | 426 | |
26dd70c3 FD |
427 | if (x->props.flags & XFRM_STATE_ESN) { |
428 | /* Attach seqhi sg right after packet payload */ | |
429 | *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
430 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
431 | } | |
432 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); | |
8631e9bd SK |
433 | ahash_request_set_callback(req, 0, ah6_output_done, skb); |
434 | ||
435 | AH_SKB_CB(skb)->tmp = iph_base; | |
1da177e4 | 436 | |
8631e9bd SK |
437 | err = crypto_ahash_digest(req); |
438 | if (err) { | |
439 | if (err == -EINPROGRESS) | |
440 | goto out; | |
441 | ||
442 | if (err == -EBUSY) | |
443 | err = NET_XMIT_DROP; | |
444 | goto out_free; | |
445 | } | |
446 | ||
447 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
448 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
449 | ||
450 | if (extlen) { | |
07a93626 | 451 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 452 | memcpy(&top_iph->saddr, iph_ext, extlen); |
27637df9 | 453 | #else |
8631e9bd | 454 | memcpy(&top_iph->daddr, iph_ext, extlen); |
27637df9 | 455 | #endif |
1da177e4 LT |
456 | } |
457 | ||
8631e9bd SK |
458 | out_free: |
459 | kfree(iph_base); | |
460 | out: | |
1da177e4 LT |
461 | return err; |
462 | } | |
463 | ||
8631e9bd SK |
464 | static void ah6_input_done(struct crypto_async_request *base, int err) |
465 | { | |
466 | u8 *auth_data; | |
467 | u8 *icv; | |
468 | u8 *work_iph; | |
469 | struct sk_buff *skb = base->data; | |
470 | struct xfrm_state *x = xfrm_input_state(skb); | |
471 | struct ah_data *ahp = x->data; | |
472 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
473 | int hdr_len = skb_network_header_len(skb); | |
474 | int ah_hlen = (ah->hdrlen + 2) << 2; | |
475 | ||
476 | work_iph = AH_SKB_CB(skb)->tmp; | |
477 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
478 | icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); | |
479 | ||
67ba4152 | 480 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
8631e9bd SK |
481 | if (err) |
482 | goto out; | |
483 | ||
b7ea81a5 NB |
484 | err = ah->nexthdr; |
485 | ||
8631e9bd SK |
486 | skb->network_header += ah_hlen; |
487 | memcpy(skb_network_header(skb), work_iph, hdr_len); | |
488 | __skb_pull(skb, ah_hlen + hdr_len); | |
a9403f8a LR |
489 | if (x->props.mode == XFRM_MODE_TUNNEL) |
490 | skb_reset_transport_header(skb); | |
491 | else | |
492 | skb_set_transport_header(skb, -hdr_len); | |
8631e9bd SK |
493 | out: |
494 | kfree(AH_SKB_CB(skb)->tmp); | |
495 | xfrm_input_resume(skb, err); | |
496 | } | |
497 | ||
498 | ||
499 | ||
e695633e | 500 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
501 | { |
502 | /* | |
503 | * Before process AH | |
504 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] | |
505 | * |<-------------->| hdr_len | |
506 | * | |
507 | * To erase AH: | |
508 | * Keeping copy of cleared headers. After AH processing, | |
b0e380b1 ACM |
509 | * Moving the pointer of skb->network_header by using skb_pull as long |
510 | * as AH header length. Then copy back the copy as long as hdr_len | |
1da177e4 | 511 | * If destination header following AH exists, copy it into after [Ext2]. |
1ab1457c | 512 | * |
1da177e4 LT |
513 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
514 | * There is offset of AH before IPv6 header after the process. | |
515 | */ | |
516 | ||
8631e9bd SK |
517 | u8 *auth_data; |
518 | u8 *icv; | |
519 | u8 *work_iph; | |
520 | struct sk_buff *trailer; | |
521 | struct crypto_ahash *ahash; | |
522 | struct ahash_request *req; | |
523 | struct scatterlist *sg; | |
87bdc48d | 524 | struct ip_auth_hdr *ah; |
0660e03f | 525 | struct ipv6hdr *ip6h; |
1da177e4 | 526 | struct ah_data *ahp; |
1da177e4 LT |
527 | u16 hdr_len; |
528 | u16 ah_hlen; | |
529 | int nexthdr; | |
8631e9bd SK |
530 | int nfrags; |
531 | int err = -ENOMEM; | |
8d6da6f3 FD |
532 | int seqhi_len = 0; |
533 | __be32 *seqhi; | |
534 | int sglists = 0; | |
535 | struct scatterlist *seqhisg; | |
1da177e4 LT |
536 | |
537 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) | |
538 | goto out; | |
539 | ||
540 | /* We are going to _remove_ AH header to keep sockets happy, | |
541 | * so... Later this can change. */ | |
14bbd6a5 | 542 | if (skb_unclone(skb, GFP_ATOMIC)) |
1da177e4 LT |
543 | goto out; |
544 | ||
7aa68cb9 HX |
545 | skb->ip_summed = CHECKSUM_NONE; |
546 | ||
8631e9bd | 547 | hdr_len = skb_network_header_len(skb); |
87bdc48d | 548 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 549 | ahp = x->data; |
8631e9bd SK |
550 | ahash = ahp->ahash; |
551 | ||
1da177e4 LT |
552 | nexthdr = ah->nexthdr; |
553 | ah_hlen = (ah->hdrlen + 2) << 2; | |
554 | ||
87bdc48d HX |
555 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
556 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) | |
1ab1457c | 557 | goto out; |
1da177e4 LT |
558 | |
559 | if (!pskb_may_pull(skb, ah_hlen)) | |
560 | goto out; | |
561 | ||
8631e9bd SK |
562 | |
563 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) | |
564 | goto out; | |
565 | nfrags = err; | |
566 | ||
4b0ef1f2 DH |
567 | ah = (struct ip_auth_hdr *)skb->data; |
568 | ip6h = ipv6_hdr(skb); | |
569 | ||
570 | skb_push(skb, hdr_len); | |
571 | ||
8d6da6f3 FD |
572 | if (x->props.flags & XFRM_STATE_ESN) { |
573 | sglists = 1; | |
574 | seqhi_len = sizeof(*seqhi); | |
575 | } | |
576 | ||
577 | work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + | |
578 | ahp->icv_trunc_len + seqhi_len); | |
8631e9bd SK |
579 | if (!work_iph) |
580 | goto out; | |
581 | ||
8d6da6f3 FD |
582 | auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); |
583 | seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); | |
584 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
585 | req = ah_tmp_req(ahash, icv); |
586 | sg = ah_req_sg(ahash, req); | |
8d6da6f3 | 587 | seqhisg = sg + nfrags; |
8631e9bd SK |
588 | |
589 | memcpy(work_iph, ip6h, hdr_len); | |
590 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
591 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
592 | ||
0660e03f | 593 | if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) |
8631e9bd SK |
594 | goto out_free; |
595 | ||
0660e03f ACM |
596 | ip6h->priority = 0; |
597 | ip6h->flow_lbl[0] = 0; | |
598 | ip6h->flow_lbl[1] = 0; | |
599 | ip6h->flow_lbl[2] = 0; | |
600 | ip6h->hop_limit = 0; | |
1da177e4 | 601 | |
8d6da6f3 FD |
602 | sg_init_table(sg, nfrags + sglists); |
603 | skb_to_sgvec_nomark(skb, sg, 0, skb->len); | |
604 | ||
605 | if (x->props.flags & XFRM_STATE_ESN) { | |
606 | /* Attach seqhi sg right after packet payload */ | |
607 | *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; | |
608 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
609 | } | |
1da177e4 | 610 | |
8d6da6f3 | 611 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); |
8631e9bd SK |
612 | ahash_request_set_callback(req, 0, ah6_input_done, skb); |
613 | ||
614 | AH_SKB_CB(skb)->tmp = work_iph; | |
615 | ||
616 | err = crypto_ahash_digest(req); | |
617 | if (err) { | |
618 | if (err == -EINPROGRESS) | |
619 | goto out; | |
620 | ||
8631e9bd | 621 | goto out_free; |
1da177e4 | 622 | } |
0ebea8ef | 623 | |
67ba4152 | 624 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
0ebea8ef | 625 | if (err) |
8631e9bd | 626 | goto out_free; |
1da177e4 | 627 | |
b0e380b1 | 628 | skb->network_header += ah_hlen; |
8631e9bd | 629 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
31a4ab93 | 630 | __skb_pull(skb, ah_hlen + hdr_len); |
1da177e4 | 631 | |
a9403f8a LR |
632 | if (x->props.mode == XFRM_MODE_TUNNEL) |
633 | skb_reset_transport_header(skb); | |
634 | else | |
635 | skb_set_transport_header(skb, -hdr_len); | |
636 | ||
8631e9bd | 637 | err = nexthdr; |
1da177e4 | 638 | |
8631e9bd SK |
639 | out_free: |
640 | kfree(work_iph); | |
1da177e4 | 641 | out: |
07d4ee58 | 642 | return err; |
1da177e4 LT |
643 | } |
644 | ||
e924d2d6 SK |
645 | static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
646 | u8 type, u8 code, int offset, __be32 info) | |
1da177e4 | 647 | { |
4fb236ba | 648 | struct net *net = dev_net(skb->dev); |
67ba4152 IM |
649 | struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; |
650 | struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); | |
1da177e4 LT |
651 | struct xfrm_state *x; |
652 | ||
b3b2b9e1 | 653 | if (type != ICMPV6_PKT_TOOBIG && |
ec18d9a2 | 654 | type != NDISC_REDIRECT) |
e924d2d6 | 655 | return 0; |
1da177e4 | 656 | |
bd55775c | 657 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); |
1da177e4 | 658 | if (!x) |
e924d2d6 | 659 | return 0; |
1da177e4 | 660 | |
ec18d9a2 | 661 | if (type == NDISC_REDIRECT) |
b55b76b2 | 662 | ip6_redirect(skb, net, skb->dev->ifindex, 0); |
ec18d9a2 DM |
663 | else |
664 | ip6_update_pmtu(skb, net, info, 0, 0); | |
1da177e4 | 665 | xfrm_state_put(x); |
e924d2d6 SK |
666 | |
667 | return 0; | |
1da177e4 LT |
668 | } |
669 | ||
72cb6962 | 670 | static int ah6_init_state(struct xfrm_state *x) |
1da177e4 LT |
671 | { |
672 | struct ah_data *ahp = NULL; | |
673 | struct xfrm_algo_desc *aalg_desc; | |
8631e9bd | 674 | struct crypto_ahash *ahash; |
1da177e4 LT |
675 | |
676 | if (!x->aalg) | |
677 | goto error; | |
678 | ||
1da177e4 LT |
679 | if (x->encap) |
680 | goto error; | |
681 | ||
0c600eda | 682 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
1da177e4 LT |
683 | if (ahp == NULL) |
684 | return -ENOMEM; | |
685 | ||
8631e9bd SK |
686 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
687 | if (IS_ERR(ahash)) | |
07d4ee58 HX |
688 | goto error; |
689 | ||
8631e9bd SK |
690 | ahp->ahash = ahash; |
691 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
bc31d3b2 | 692 | (x->aalg->alg_key_len + 7) / 8)) |
1da177e4 | 693 | goto error; |
1ab1457c | 694 | |
1da177e4 LT |
695 | /* |
696 | * Lookup the algorithm description maintained by xfrm_algo, | |
697 | * verify crypto transform properties, and store information | |
698 | * we need for AH processing. This lookup cannot fail here | |
07d4ee58 | 699 | * after a successful crypto_alloc_hash(). |
1da177e4 LT |
700 | */ |
701 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
702 | BUG_ON(!aalg_desc); | |
703 | ||
704 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
8631e9bd | 705 | crypto_ahash_digestsize(ahash)) { |
f3213831 JP |
706 | pr_info("AH: %s digestsize %u != %hu\n", |
707 | x->aalg->alg_name, crypto_ahash_digestsize(ahash), | |
708 | aalg_desc->uinfo.auth.icv_fullbits/8); | |
1da177e4 LT |
709 | goto error; |
710 | } | |
1ab1457c | 711 | |
1da177e4 | 712 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 713 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
1ab1457c | 714 | |
87bdc48d HX |
715 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
716 | ahp->icv_trunc_len); | |
ca68145f HX |
717 | switch (x->props.mode) { |
718 | case XFRM_MODE_BEET: | |
719 | case XFRM_MODE_TRANSPORT: | |
720 | break; | |
721 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 722 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 723 | break; |
ca68145f HX |
724 | default: |
725 | goto error; | |
726 | } | |
1da177e4 LT |
727 | x->data = ahp; |
728 | ||
729 | return 0; | |
730 | ||
731 | error: | |
732 | if (ahp) { | |
8631e9bd | 733 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
734 | kfree(ahp); |
735 | } | |
736 | return -EINVAL; | |
737 | } | |
738 | ||
739 | static void ah6_destroy(struct xfrm_state *x) | |
740 | { | |
741 | struct ah_data *ahp = x->data; | |
742 | ||
743 | if (!ahp) | |
744 | return; | |
745 | ||
8631e9bd | 746 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
747 | kfree(ahp); |
748 | } | |
749 | ||
e924d2d6 SK |
750 | static int ah6_rcv_cb(struct sk_buff *skb, int err) |
751 | { | |
752 | return 0; | |
753 | } | |
754 | ||
cc24beca | 755 | static const struct xfrm_type ah6_type = { |
1da177e4 LT |
756 | .description = "AH6", |
757 | .owner = THIS_MODULE, | |
cc24beca | 758 | .proto = IPPROTO_AH, |
436a0a40 | 759 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
760 | .init_state = ah6_init_state, |
761 | .destructor = ah6_destroy, | |
762 | .input = ah6_input, | |
aee5adb4 MN |
763 | .output = ah6_output, |
764 | .hdr_offset = xfrm6_find_1stfragopt, | |
1da177e4 LT |
765 | }; |
766 | ||
e924d2d6 | 767 | static struct xfrm6_protocol ah6_protocol = { |
1da177e4 | 768 | .handler = xfrm6_rcv, |
e924d2d6 | 769 | .cb_handler = ah6_rcv_cb, |
1da177e4 | 770 | .err_handler = ah6_err, |
e924d2d6 | 771 | .priority = 0, |
1da177e4 LT |
772 | }; |
773 | ||
774 | static int __init ah6_init(void) | |
775 | { | |
776 | if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { | |
f3213831 | 777 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
778 | return -EAGAIN; |
779 | } | |
780 | ||
e924d2d6 | 781 | if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { |
f3213831 | 782 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
783 | xfrm_unregister_type(&ah6_type, AF_INET6); |
784 | return -EAGAIN; | |
785 | } | |
786 | ||
787 | return 0; | |
788 | } | |
789 | ||
790 | static void __exit ah6_fini(void) | |
791 | { | |
e924d2d6 | 792 | if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) |
f3213831 | 793 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 LT |
794 | |
795 | if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0) | |
f3213831 | 796 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
797 | |
798 | } | |
799 | ||
800 | module_init(ah6_init); | |
801 | module_exit(ah6_fini); | |
802 | ||
803 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 804 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); |