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1 | /* |
2 | * Copyright (C)2002 USAGI/WIDE Project |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify |
5 | * it under the terms of the GNU General Public License as published by |
6 | * the Free Software Foundation; either version 2 of the License, or |
7 | * (at your option) any later version. |
8 | * |
9 | * This program is distributed in the hope that it will be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | * GNU General Public License for more details. |
13 | * |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write to the Free Software |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
17 | * |
18 | * Authors |
19 | * |
20 | * Mitsuru KANDA @USAGI : IPv6 Support |
21 | * Kazunori MIYAZAWA @USAGI : |
22 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> |
23 | * |
24 | * This file is derived from net/ipv4/ah.c. |
25 | */ |
26 | |
27 | #include <crypto/hash.h> |
28 | #include <linux/module.h> |
29 | #include <linux/slab.h> |
30 | #include <net/ip.h> |
31 | #include <net/ah.h> |
32 | #include <linux/crypto.h> |
33 | #include <linux/pfkeyv2.h> |
34 | #include <linux/string.h> |
35 | #include <linux/scatterlist.h> |
36 | #include <net/icmp.h> |
37 | #include <net/ipv6.h> |
38 | #include <net/protocol.h> |
39 | #include <net/xfrm.h> |
40 | |
41 | #define IPV6HDR_BASELEN 8 |
42 | |
43 | struct 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 | |
51 | struct 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 | |
58 | static 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 | |
77 | static inline struct tmp_ext *ah_tmp_ext(void *base) |
78 | { |
79 | return base + IPV6HDR_BASELEN; |
80 | } |
81 | |
82 | static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) |
83 | { |
84 | return tmp + offset; |
85 | } |
86 | |
87 | static 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 | |
93 | static 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 | |
106 | static 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 | |
114 | static int zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) |
115 | { |
116 | u8 *opt = (u8 *)opthdr; |
117 | int len = ipv6_optlen(opthdr); |
118 | int off = 0; |
119 | int optlen = 0; |
120 | |
121 | off += 2; |
122 | len -= 2; |
123 | |
124 | while (len > 0) { |
125 | |
126 | switch (opt[off]) { |
127 | |
128 | case IPV6_TLV_PAD0: |
129 | optlen = 1; |
130 | break; |
131 | default: |
132 | if (len < 2) |
133 | goto bad; |
134 | optlen = opt[off+1]+2; |
135 | if (len < optlen) |
136 | goto bad; |
137 | if (opt[off] & 0x20) |
138 | memset(&opt[off+2], 0, opt[off+1]); |
139 | break; |
140 | } |
141 | |
142 | off += optlen; |
143 | len -= optlen; |
144 | } |
145 | if (len == 0) |
146 | return 1; |
147 | |
148 | bad: |
149 | return 0; |
150 | } |
151 | |
152 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
153 | /** |
154 | * ipv6_rearrange_destopt - rearrange IPv6 destination options header |
155 | * @iph: IPv6 header |
156 | * @destopt: destionation options header |
157 | */ |
158 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) |
159 | { |
160 | u8 *opt = (u8 *)destopt; |
161 | int len = ipv6_optlen(destopt); |
162 | int off = 0; |
163 | int optlen = 0; |
164 | |
165 | off += 2; |
166 | len -= 2; |
167 | |
168 | while (len > 0) { |
169 | |
170 | switch (opt[off]) { |
171 | |
172 | case IPV6_TLV_PAD0: |
173 | optlen = 1; |
174 | break; |
175 | default: |
176 | if (len < 2) |
177 | goto bad; |
178 | optlen = opt[off+1]+2; |
179 | if (len < optlen) |
180 | goto bad; |
181 | |
182 | /* Rearrange the source address in @iph and the |
183 | * addresses in home address option for final source. |
184 | * See 11.3.2 of RFC 3775 for details. |
185 | */ |
186 | if (opt[off] == IPV6_TLV_HAO) { |
187 | struct in6_addr final_addr; |
188 | struct ipv6_destopt_hao *hao; |
189 | |
190 | hao = (struct ipv6_destopt_hao *)&opt[off]; |
191 | if (hao->length != sizeof(hao->addr)) { |
192 | if (net_ratelimit()) |
193 | printk(KERN_WARNING "destopt hao: invalid header length: %u\n", hao->length); |
194 | goto bad; |
195 | } |
196 | ipv6_addr_copy(&final_addr, &hao->addr); |
197 | ipv6_addr_copy(&hao->addr, &iph->saddr); |
198 | ipv6_addr_copy(&iph->saddr, &final_addr); |
199 | } |
200 | break; |
201 | } |
202 | |
203 | off += optlen; |
204 | len -= optlen; |
205 | } |
206 | /* Note: ok if len == 0 */ |
207 | bad: |
208 | return; |
209 | } |
210 | #else |
211 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} |
212 | #endif |
213 | |
214 | /** |
215 | * ipv6_rearrange_rthdr - rearrange IPv6 routing header |
216 | * @iph: IPv6 header |
217 | * @rthdr: routing header |
218 | * |
219 | * Rearrange the destination address in @iph and the addresses in @rthdr |
220 | * so that they appear in the order they will at the final destination. |
221 | * See Appendix A2 of RFC 2402 for details. |
222 | */ |
223 | static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) |
224 | { |
225 | int segments, segments_left; |
226 | struct in6_addr *addrs; |
227 | struct in6_addr final_addr; |
228 | |
229 | segments_left = rthdr->segments_left; |
230 | if (segments_left == 0) |
231 | return; |
232 | rthdr->segments_left = 0; |
233 | |
234 | /* The value of rthdr->hdrlen has been verified either by the system |
235 | * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming |
236 | * packets. So we can assume that it is even and that segments is |
237 | * greater than or equal to segments_left. |
238 | * |
239 | * For the same reason we can assume that this option is of type 0. |
240 | */ |
241 | segments = rthdr->hdrlen >> 1; |
242 | |
243 | addrs = ((struct rt0_hdr *)rthdr)->addr; |
244 | ipv6_addr_copy(&final_addr, addrs + segments - 1); |
245 | |
246 | addrs += segments - segments_left; |
247 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); |
248 | |
249 | ipv6_addr_copy(addrs, &iph->daddr); |
250 | ipv6_addr_copy(&iph->daddr, &final_addr); |
251 | } |
252 | |
253 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
254 | { |
255 | union { |
256 | struct ipv6hdr *iph; |
257 | struct ipv6_opt_hdr *opth; |
258 | struct ipv6_rt_hdr *rth; |
259 | char *raw; |
260 | } exthdr = { .iph = iph }; |
261 | char *end = exthdr.raw + len; |
262 | int nexthdr = iph->nexthdr; |
263 | |
264 | exthdr.iph++; |
265 | |
266 | while (exthdr.raw < end) { |
267 | switch (nexthdr) { |
268 | case NEXTHDR_DEST: |
269 | if (dir == XFRM_POLICY_OUT) |
270 | ipv6_rearrange_destopt(iph, exthdr.opth); |
271 | case NEXTHDR_HOP: |
272 | if (!zero_out_mutable_opts(exthdr.opth)) { |
273 | LIMIT_NETDEBUG( |
274 | KERN_WARNING "overrun %sopts\n", |
275 | nexthdr == NEXTHDR_HOP ? |
276 | "hop" : "dest"); |
277 | return -EINVAL; |
278 | } |
279 | break; |
280 | |
281 | case NEXTHDR_ROUTING: |
282 | ipv6_rearrange_rthdr(iph, exthdr.rth); |
283 | break; |
284 | |
285 | default : |
286 | return 0; |
287 | } |
288 | |
289 | nexthdr = exthdr.opth->nexthdr; |
290 | exthdr.raw += ipv6_optlen(exthdr.opth); |
291 | } |
292 | |
293 | return 0; |
294 | } |
295 | |
296 | static void ah6_output_done(struct crypto_async_request *base, int err) |
297 | { |
298 | int extlen; |
299 | u8 *iph_base; |
300 | u8 *icv; |
301 | struct sk_buff *skb = base->data; |
302 | struct xfrm_state *x = skb_dst(skb)->xfrm; |
303 | struct ah_data *ahp = x->data; |
304 | struct ipv6hdr *top_iph = ipv6_hdr(skb); |
305 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); |
306 | struct tmp_ext *iph_ext; |
307 | |
308 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
309 | if (extlen) |
310 | extlen += sizeof(*iph_ext); |
311 | |
312 | iph_base = AH_SKB_CB(skb)->tmp; |
313 | iph_ext = ah_tmp_ext(iph_base); |
314 | icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); |
315 | |
316 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); |
317 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); |
318 | |
319 | if (extlen) { |
320 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
321 | memcpy(&top_iph->saddr, iph_ext, extlen); |
322 | #else |
323 | memcpy(&top_iph->daddr, iph_ext, extlen); |
324 | #endif |
325 | } |
326 | |
327 | err = ah->nexthdr; |
328 | |
329 | kfree(AH_SKB_CB(skb)->tmp); |
330 | xfrm_output_resume(skb, err); |
331 | } |
332 | |
333 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
334 | { |
335 | int err; |
336 | int nfrags; |
337 | int extlen; |
338 | u8 *iph_base; |
339 | u8 *icv; |
340 | u8 nexthdr; |
341 | struct sk_buff *trailer; |
342 | struct crypto_ahash *ahash; |
343 | struct ahash_request *req; |
344 | struct scatterlist *sg; |
345 | struct ipv6hdr *top_iph; |
346 | struct ip_auth_hdr *ah; |
347 | struct ah_data *ahp; |
348 | struct tmp_ext *iph_ext; |
349 | |
350 | ahp = x->data; |
351 | ahash = ahp->ahash; |
352 | |
353 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) |
354 | goto out; |
355 | nfrags = err; |
356 | |
357 | skb_push(skb, -skb_network_offset(skb)); |
358 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
359 | if (extlen) |
360 | extlen += sizeof(*iph_ext); |
361 | |
362 | err = -ENOMEM; |
363 | iph_base = ah_alloc_tmp(ahash, nfrags, IPV6HDR_BASELEN + extlen); |
364 | if (!iph_base) |
365 | goto out; |
366 | |
367 | iph_ext = ah_tmp_ext(iph_base); |
368 | icv = ah_tmp_icv(ahash, iph_ext, extlen); |
369 | req = ah_tmp_req(ahash, icv); |
370 | sg = ah_req_sg(ahash, req); |
371 | |
372 | ah = ip_auth_hdr(skb); |
373 | memset(ah->auth_data, 0, ahp->icv_trunc_len); |
374 | |
375 | top_iph = ipv6_hdr(skb); |
376 | top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); |
377 | |
378 | nexthdr = *skb_mac_header(skb); |
379 | *skb_mac_header(skb) = IPPROTO_AH; |
380 | |
381 | /* When there are no extension headers, we only need to save the first |
382 | * 8 bytes of the base IP header. |
383 | */ |
384 | memcpy(iph_base, top_iph, IPV6HDR_BASELEN); |
385 | |
386 | if (extlen) { |
387 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
388 | memcpy(iph_ext, &top_iph->saddr, extlen); |
389 | #else |
390 | memcpy(iph_ext, &top_iph->daddr, extlen); |
391 | #endif |
392 | err = ipv6_clear_mutable_options(top_iph, |
393 | extlen - sizeof(*iph_ext) + |
394 | sizeof(*top_iph), |
395 | XFRM_POLICY_OUT); |
396 | if (err) |
397 | goto out_free; |
398 | } |
399 | |
400 | ah->nexthdr = nexthdr; |
401 | |
402 | top_iph->priority = 0; |
403 | top_iph->flow_lbl[0] = 0; |
404 | top_iph->flow_lbl[1] = 0; |
405 | top_iph->flow_lbl[2] = 0; |
406 | top_iph->hop_limit = 0; |
407 | |
408 | ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; |
409 | |
410 | ah->reserved = 0; |
411 | ah->spi = x->id.spi; |
412 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output); |
413 | |
414 | sg_init_table(sg, nfrags); |
415 | skb_to_sgvec(skb, sg, 0, skb->len); |
416 | |
417 | ahash_request_set_crypt(req, sg, icv, skb->len); |
418 | ahash_request_set_callback(req, 0, ah6_output_done, skb); |
419 | |
420 | AH_SKB_CB(skb)->tmp = iph_base; |
421 | |
422 | err = crypto_ahash_digest(req); |
423 | if (err) { |
424 | if (err == -EINPROGRESS) |
425 | goto out; |
426 | |
427 | if (err == -EBUSY) |
428 | err = NET_XMIT_DROP; |
429 | goto out_free; |
430 | } |
431 | |
432 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); |
433 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); |
434 | |
435 | if (extlen) { |
436 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) |
437 | memcpy(&top_iph->saddr, iph_ext, extlen); |
438 | #else |
439 | memcpy(&top_iph->daddr, iph_ext, extlen); |
440 | #endif |
441 | } |
442 | |
443 | out_free: |
444 | kfree(iph_base); |
445 | out: |
446 | return err; |
447 | } |
448 | |
449 | static void ah6_input_done(struct crypto_async_request *base, int err) |
450 | { |
451 | u8 *auth_data; |
452 | u8 *icv; |
453 | u8 *work_iph; |
454 | struct sk_buff *skb = base->data; |
455 | struct xfrm_state *x = xfrm_input_state(skb); |
456 | struct ah_data *ahp = x->data; |
457 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); |
458 | int hdr_len = skb_network_header_len(skb); |
459 | int ah_hlen = (ah->hdrlen + 2) << 2; |
460 | |
461 | work_iph = AH_SKB_CB(skb)->tmp; |
462 | auth_data = ah_tmp_auth(work_iph, hdr_len); |
463 | icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); |
464 | |
465 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; |
466 | if (err) |
467 | goto out; |
468 | |
469 | skb->network_header += ah_hlen; |
470 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
471 | __skb_pull(skb, ah_hlen + hdr_len); |
472 | skb_set_transport_header(skb, -hdr_len); |
473 | |
474 | err = ah->nexthdr; |
475 | out: |
476 | kfree(AH_SKB_CB(skb)->tmp); |
477 | xfrm_input_resume(skb, err); |
478 | } |
479 | |
480 | |
481 | |
482 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
483 | { |
484 | /* |
485 | * Before process AH |
486 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] |
487 | * |<-------------->| hdr_len |
488 | * |
489 | * To erase AH: |
490 | * Keeping copy of cleared headers. After AH processing, |
491 | * Moving the pointer of skb->network_header by using skb_pull as long |
492 | * as AH header length. Then copy back the copy as long as hdr_len |
493 | * If destination header following AH exists, copy it into after [Ext2]. |
494 | * |
495 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
496 | * There is offset of AH before IPv6 header after the process. |
497 | */ |
498 | |
499 | u8 *auth_data; |
500 | u8 *icv; |
501 | u8 *work_iph; |
502 | struct sk_buff *trailer; |
503 | struct crypto_ahash *ahash; |
504 | struct ahash_request *req; |
505 | struct scatterlist *sg; |
506 | struct ip_auth_hdr *ah; |
507 | struct ipv6hdr *ip6h; |
508 | struct ah_data *ahp; |
509 | u16 hdr_len; |
510 | u16 ah_hlen; |
511 | int nexthdr; |
512 | int nfrags; |
513 | int err = -ENOMEM; |
514 | |
515 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) |
516 | goto out; |
517 | |
518 | /* We are going to _remove_ AH header to keep sockets happy, |
519 | * so... Later this can change. */ |
520 | if (skb_cloned(skb) && |
521 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) |
522 | goto out; |
523 | |
524 | skb->ip_summed = CHECKSUM_NONE; |
525 | |
526 | hdr_len = skb_network_header_len(skb); |
527 | ah = (struct ip_auth_hdr *)skb->data; |
528 | ahp = x->data; |
529 | ahash = ahp->ahash; |
530 | |
531 | nexthdr = ah->nexthdr; |
532 | ah_hlen = (ah->hdrlen + 2) << 2; |
533 | |
534 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
535 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) |
536 | goto out; |
537 | |
538 | if (!pskb_may_pull(skb, ah_hlen)) |
539 | goto out; |
540 | |
541 | ip6h = ipv6_hdr(skb); |
542 | |
543 | skb_push(skb, hdr_len); |
544 | |
545 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) |
546 | goto out; |
547 | nfrags = err; |
548 | |
549 | work_iph = ah_alloc_tmp(ahash, nfrags, hdr_len + ahp->icv_trunc_len); |
550 | if (!work_iph) |
551 | goto out; |
552 | |
553 | auth_data = ah_tmp_auth(work_iph, hdr_len); |
554 | icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); |
555 | req = ah_tmp_req(ahash, icv); |
556 | sg = ah_req_sg(ahash, req); |
557 | |
558 | memcpy(work_iph, ip6h, hdr_len); |
559 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); |
560 | memset(ah->auth_data, 0, ahp->icv_trunc_len); |
561 | |
562 | if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) |
563 | goto out_free; |
564 | |
565 | ip6h->priority = 0; |
566 | ip6h->flow_lbl[0] = 0; |
567 | ip6h->flow_lbl[1] = 0; |
568 | ip6h->flow_lbl[2] = 0; |
569 | ip6h->hop_limit = 0; |
570 | |
571 | sg_init_table(sg, nfrags); |
572 | skb_to_sgvec(skb, sg, 0, skb->len); |
573 | |
574 | ahash_request_set_crypt(req, sg, icv, skb->len); |
575 | ahash_request_set_callback(req, 0, ah6_input_done, skb); |
576 | |
577 | AH_SKB_CB(skb)->tmp = work_iph; |
578 | |
579 | err = crypto_ahash_digest(req); |
580 | if (err) { |
581 | if (err == -EINPROGRESS) |
582 | goto out; |
583 | |
584 | if (err == -EBUSY) |
585 | err = NET_XMIT_DROP; |
586 | goto out_free; |
587 | } |
588 | |
589 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; |
590 | if (err) |
591 | goto out_free; |
592 | |
593 | skb->network_header += ah_hlen; |
594 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
595 | skb->transport_header = skb->network_header; |
596 | __skb_pull(skb, ah_hlen + hdr_len); |
597 | |
598 | err = nexthdr; |
599 | |
600 | out_free: |
601 | kfree(work_iph); |
602 | out: |
603 | return err; |
604 | } |
605 | |
606 | static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
607 | u8 type, u8 code, int offset, __be32 info) |
608 | { |
609 | struct net *net = dev_net(skb->dev); |
610 | struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; |
611 | struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset); |
612 | struct xfrm_state *x; |
613 | |
614 | if (type != ICMPV6_DEST_UNREACH && |
615 | type != ICMPV6_PKT_TOOBIG) |
616 | return; |
617 | |
618 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); |
619 | if (!x) |
620 | return; |
621 | |
622 | NETDEBUG(KERN_DEBUG "pmtu discovery on SA AH/%08x/%pI6\n", |
623 | ntohl(ah->spi), &iph->daddr); |
624 | |
625 | xfrm_state_put(x); |
626 | } |
627 | |
628 | static int ah6_init_state(struct xfrm_state *x) |
629 | { |
630 | struct ah_data *ahp = NULL; |
631 | struct xfrm_algo_desc *aalg_desc; |
632 | struct crypto_ahash *ahash; |
633 | |
634 | if (!x->aalg) |
635 | goto error; |
636 | |
637 | if (x->encap) |
638 | goto error; |
639 | |
640 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
641 | if (ahp == NULL) |
642 | return -ENOMEM; |
643 | |
644 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
645 | if (IS_ERR(ahash)) |
646 | goto error; |
647 | |
648 | ahp->ahash = ahash; |
649 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, |
650 | (x->aalg->alg_key_len + 7) / 8)) |
651 | goto error; |
652 | |
653 | /* |
654 | * Lookup the algorithm description maintained by xfrm_algo, |
655 | * verify crypto transform properties, and store information |
656 | * we need for AH processing. This lookup cannot fail here |
657 | * after a successful crypto_alloc_hash(). |
658 | */ |
659 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); |
660 | BUG_ON(!aalg_desc); |
661 | |
662 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != |
663 | crypto_ahash_digestsize(ahash)) { |
664 | printk(KERN_INFO "AH: %s digestsize %u != %hu\n", |
665 | x->aalg->alg_name, crypto_ahash_digestsize(ahash), |
666 | aalg_desc->uinfo.auth.icv_fullbits/8); |
667 | goto error; |
668 | } |
669 | |
670 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
671 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
672 | |
673 | BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN); |
674 | |
675 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
676 | ahp->icv_trunc_len); |
677 | switch (x->props.mode) { |
678 | case XFRM_MODE_BEET: |
679 | case XFRM_MODE_TRANSPORT: |
680 | break; |
681 | case XFRM_MODE_TUNNEL: |
682 | x->props.header_len += sizeof(struct ipv6hdr); |
683 | break; |
684 | default: |
685 | goto error; |
686 | } |
687 | x->data = ahp; |
688 | |
689 | return 0; |
690 | |
691 | error: |
692 | if (ahp) { |
693 | crypto_free_ahash(ahp->ahash); |
694 | kfree(ahp); |
695 | } |
696 | return -EINVAL; |
697 | } |
698 | |
699 | static void ah6_destroy(struct xfrm_state *x) |
700 | { |
701 | struct ah_data *ahp = x->data; |
702 | |
703 | if (!ahp) |
704 | return; |
705 | |
706 | crypto_free_ahash(ahp->ahash); |
707 | kfree(ahp); |
708 | } |
709 | |
710 | static const struct xfrm_type ah6_type = |
711 | { |
712 | .description = "AH6", |
713 | .owner = THIS_MODULE, |
714 | .proto = IPPROTO_AH, |
715 | .flags = XFRM_TYPE_REPLAY_PROT, |
716 | .init_state = ah6_init_state, |
717 | .destructor = ah6_destroy, |
718 | .input = ah6_input, |
719 | .output = ah6_output, |
720 | .hdr_offset = xfrm6_find_1stfragopt, |
721 | }; |
722 | |
723 | static const struct inet6_protocol ah6_protocol = { |
724 | .handler = xfrm6_rcv, |
725 | .err_handler = ah6_err, |
726 | .flags = INET6_PROTO_NOPOLICY, |
727 | }; |
728 | |
729 | static int __init ah6_init(void) |
730 | { |
731 | if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { |
732 | printk(KERN_INFO "ipv6 ah init: can't add xfrm type\n"); |
733 | return -EAGAIN; |
734 | } |
735 | |
736 | if (inet6_add_protocol(&ah6_protocol, IPPROTO_AH) < 0) { |
737 | printk(KERN_INFO "ipv6 ah init: can't add protocol\n"); |
738 | xfrm_unregister_type(&ah6_type, AF_INET6); |
739 | return -EAGAIN; |
740 | } |
741 | |
742 | return 0; |
743 | } |
744 | |
745 | static void __exit ah6_fini(void) |
746 | { |
747 | if (inet6_del_protocol(&ah6_protocol, IPPROTO_AH) < 0) |
748 | printk(KERN_INFO "ipv6 ah close: can't remove protocol\n"); |
749 | |
750 | if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0) |
751 | printk(KERN_INFO "ipv6 ah close: can't remove xfrm type\n"); |
752 | |
753 | } |
754 | |
755 | module_init(ah6_init); |
756 | module_exit(ah6_fini); |
757 | |
758 | MODULE_LICENSE("GPL"); |
759 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); |
760 |
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