Commit | Line | Data |
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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 LT |
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 | * | |
1ab1457c | 20 | * Mitsuru KANDA @USAGI : IPv6 Support |
1da177e4 LT |
21 | * Kazunori MIYAZAWA @USAGI : |
22 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
1ab1457c | 23 | * |
1da177e4 LT |
24 | * This file is derived from net/ipv4/ah.c. |
25 | */ | |
26 | ||
f3213831 JP |
27 | #define pr_fmt(fmt) "IPv6: " fmt |
28 | ||
8631e9bd | 29 | #include <crypto/hash.h> |
1da177e4 | 30 | #include <linux/module.h> |
5a0e3ad6 | 31 | #include <linux/slab.h> |
1da177e4 LT |
32 | #include <net/ip.h> |
33 | #include <net/ah.h> | |
34 | #include <linux/crypto.h> | |
35 | #include <linux/pfkeyv2.h> | |
36 | #include <linux/string.h> | |
8631e9bd | 37 | #include <linux/scatterlist.h> |
81aded24 | 38 | #include <net/ip6_route.h> |
1da177e4 LT |
39 | #include <net/icmp.h> |
40 | #include <net/ipv6.h> | |
14c85021 | 41 | #include <net/protocol.h> |
1da177e4 | 42 | #include <net/xfrm.h> |
1da177e4 | 43 | |
8631e9bd SK |
44 | #define IPV6HDR_BASELEN 8 |
45 | ||
46 | struct tmp_ext { | |
07a93626 | 47 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
48 | struct in6_addr saddr; |
49 | #endif | |
50 | struct in6_addr daddr; | |
51 | char hdrs[0]; | |
52 | }; | |
53 | ||
54 | struct ah_skb_cb { | |
55 | struct xfrm_skb_cb xfrm; | |
56 | void *tmp; | |
57 | }; | |
58 | ||
59 | #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) | |
60 | ||
61 | static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, | |
62 | unsigned int size) | |
63 | { | |
64 | unsigned int len; | |
65 | ||
66 | len = size + crypto_ahash_digestsize(ahash) + | |
67 | (crypto_ahash_alignmask(ahash) & | |
68 | ~(crypto_tfm_ctx_alignment() - 1)); | |
69 | ||
70 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
71 | ||
72 | len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); | |
73 | len = ALIGN(len, __alignof__(struct scatterlist)); | |
74 | ||
75 | len += sizeof(struct scatterlist) * nfrags; | |
76 | ||
77 | return kmalloc(len, GFP_ATOMIC); | |
78 | } | |
79 | ||
80 | static inline struct tmp_ext *ah_tmp_ext(void *base) | |
81 | { | |
82 | return base + IPV6HDR_BASELEN; | |
83 | } | |
84 | ||
85 | static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) | |
86 | { | |
87 | return tmp + offset; | |
88 | } | |
89 | ||
90 | static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, | |
91 | unsigned int offset) | |
92 | { | |
93 | return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); | |
94 | } | |
95 | ||
96 | static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, | |
97 | u8 *icv) | |
98 | { | |
99 | struct ahash_request *req; | |
100 | ||
101 | req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), | |
102 | crypto_tfm_ctx_alignment()); | |
103 | ||
104 | ahash_request_set_tfm(req, ahash); | |
105 | ||
106 | return req; | |
107 | } | |
108 | ||
109 | static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, | |
110 | struct ahash_request *req) | |
111 | { | |
112 | return (void *)ALIGN((unsigned long)(req + 1) + | |
113 | crypto_ahash_reqsize(ahash), | |
114 | __alignof__(struct scatterlist)); | |
115 | } | |
116 | ||
a50feda5 | 117 | static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) |
1da177e4 LT |
118 | { |
119 | u8 *opt = (u8 *)opthdr; | |
120 | int len = ipv6_optlen(opthdr); | |
121 | int off = 0; | |
122 | int optlen = 0; | |
123 | ||
124 | off += 2; | |
125 | len -= 2; | |
126 | ||
127 | while (len > 0) { | |
128 | ||
129 | switch (opt[off]) { | |
130 | ||
1de5a71c | 131 | case IPV6_TLV_PAD1: |
1da177e4 LT |
132 | optlen = 1; |
133 | break; | |
134 | default: | |
1ab1457c | 135 | if (len < 2) |
1da177e4 LT |
136 | goto bad; |
137 | optlen = opt[off+1]+2; | |
138 | if (len < optlen) | |
139 | goto bad; | |
140 | if (opt[off] & 0x20) | |
141 | memset(&opt[off+2], 0, opt[off+1]); | |
142 | break; | |
143 | } | |
144 | ||
145 | off += optlen; | |
146 | len -= optlen; | |
147 | } | |
148 | if (len == 0) | |
a50feda5 | 149 | return true; |
1da177e4 LT |
150 | |
151 | bad: | |
a50feda5 | 152 | return false; |
1da177e4 LT |
153 | } |
154 | ||
07a93626 | 155 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
27637df9 MN |
156 | /** |
157 | * ipv6_rearrange_destopt - rearrange IPv6 destination options header | |
158 | * @iph: IPv6 header | |
159 | * @destopt: destionation options header | |
160 | */ | |
161 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) | |
162 | { | |
163 | u8 *opt = (u8 *)destopt; | |
164 | int len = ipv6_optlen(destopt); | |
165 | int off = 0; | |
166 | int optlen = 0; | |
167 | ||
168 | off += 2; | |
169 | len -= 2; | |
170 | ||
171 | while (len > 0) { | |
172 | ||
173 | switch (opt[off]) { | |
174 | ||
1de5a71c | 175 | case IPV6_TLV_PAD1: |
27637df9 MN |
176 | optlen = 1; |
177 | break; | |
178 | default: | |
179 | if (len < 2) | |
180 | goto bad; | |
181 | optlen = opt[off+1]+2; | |
182 | if (len < optlen) | |
183 | goto bad; | |
184 | ||
185 | /* Rearrange the source address in @iph and the | |
186 | * addresses in home address option for final source. | |
187 | * See 11.3.2 of RFC 3775 for details. | |
188 | */ | |
189 | if (opt[off] == IPV6_TLV_HAO) { | |
190 | struct in6_addr final_addr; | |
191 | struct ipv6_destopt_hao *hao; | |
192 | ||
193 | hao = (struct ipv6_destopt_hao *)&opt[off]; | |
194 | if (hao->length != sizeof(hao->addr)) { | |
e87cc472 JP |
195 | net_warn_ratelimited("destopt hao: invalid header length: %u\n", |
196 | hao->length); | |
27637df9 MN |
197 | goto bad; |
198 | } | |
4e3fd7a0 AD |
199 | final_addr = hao->addr; |
200 | hao->addr = iph->saddr; | |
201 | iph->saddr = final_addr; | |
27637df9 MN |
202 | } |
203 | break; | |
204 | } | |
205 | ||
206 | off += optlen; | |
207 | len -= optlen; | |
208 | } | |
e731c248 | 209 | /* Note: ok if len == 0 */ |
27637df9 MN |
210 | bad: |
211 | return; | |
212 | } | |
136ebf08 MN |
213 | #else |
214 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} | |
27637df9 MN |
215 | #endif |
216 | ||
1da177e4 LT |
217 | /** |
218 | * ipv6_rearrange_rthdr - rearrange IPv6 routing header | |
219 | * @iph: IPv6 header | |
220 | * @rthdr: routing header | |
221 | * | |
222 | * Rearrange the destination address in @iph and the addresses in @rthdr | |
223 | * so that they appear in the order they will at the final destination. | |
224 | * See Appendix A2 of RFC 2402 for details. | |
225 | */ | |
226 | static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) | |
227 | { | |
228 | int segments, segments_left; | |
229 | struct in6_addr *addrs; | |
230 | struct in6_addr final_addr; | |
231 | ||
232 | segments_left = rthdr->segments_left; | |
233 | if (segments_left == 0) | |
234 | return; | |
1ab1457c | 235 | rthdr->segments_left = 0; |
1da177e4 LT |
236 | |
237 | /* The value of rthdr->hdrlen has been verified either by the system | |
238 | * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming | |
239 | * packets. So we can assume that it is even and that segments is | |
240 | * greater than or equal to segments_left. | |
241 | * | |
242 | * For the same reason we can assume that this option is of type 0. | |
243 | */ | |
244 | segments = rthdr->hdrlen >> 1; | |
245 | ||
246 | addrs = ((struct rt0_hdr *)rthdr)->addr; | |
4e3fd7a0 | 247 | final_addr = addrs[segments - 1]; |
1da177e4 LT |
248 | |
249 | addrs += segments - segments_left; | |
250 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); | |
251 | ||
4e3fd7a0 AD |
252 | addrs[0] = iph->daddr; |
253 | iph->daddr = final_addr; | |
1da177e4 LT |
254 | } |
255 | ||
27637df9 | 256 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
1da177e4 LT |
257 | { |
258 | union { | |
259 | struct ipv6hdr *iph; | |
260 | struct ipv6_opt_hdr *opth; | |
261 | struct ipv6_rt_hdr *rth; | |
262 | char *raw; | |
263 | } exthdr = { .iph = iph }; | |
264 | char *end = exthdr.raw + len; | |
265 | int nexthdr = iph->nexthdr; | |
266 | ||
267 | exthdr.iph++; | |
268 | ||
269 | while (exthdr.raw < end) { | |
270 | switch (nexthdr) { | |
27637df9 MN |
271 | case NEXTHDR_DEST: |
272 | if (dir == XFRM_POLICY_OUT) | |
273 | ipv6_rearrange_destopt(iph, exthdr.opth); | |
1da177e4 | 274 | case NEXTHDR_HOP: |
1da177e4 | 275 | if (!zero_out_mutable_opts(exthdr.opth)) { |
64ce2073 | 276 | LIMIT_NETDEBUG( |
1da177e4 LT |
277 | KERN_WARNING "overrun %sopts\n", |
278 | nexthdr == NEXTHDR_HOP ? | |
64ce2073 | 279 | "hop" : "dest"); |
1da177e4 LT |
280 | return -EINVAL; |
281 | } | |
282 | break; | |
283 | ||
284 | case NEXTHDR_ROUTING: | |
285 | ipv6_rearrange_rthdr(iph, exthdr.rth); | |
286 | break; | |
287 | ||
288 | default : | |
289 | return 0; | |
290 | } | |
291 | ||
292 | nexthdr = exthdr.opth->nexthdr; | |
293 | exthdr.raw += ipv6_optlen(exthdr.opth); | |
294 | } | |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
8631e9bd SK |
299 | static void ah6_output_done(struct crypto_async_request *base, int err) |
300 | { | |
301 | int extlen; | |
302 | u8 *iph_base; | |
303 | u8 *icv; | |
304 | struct sk_buff *skb = base->data; | |
305 | struct xfrm_state *x = skb_dst(skb)->xfrm; | |
306 | struct ah_data *ahp = x->data; | |
307 | struct ipv6hdr *top_iph = ipv6_hdr(skb); | |
308 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
309 | struct tmp_ext *iph_ext; | |
310 | ||
311 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); | |
312 | if (extlen) | |
313 | extlen += sizeof(*iph_ext); | |
314 | ||
315 | iph_base = AH_SKB_CB(skb)->tmp; | |
316 | iph_ext = ah_tmp_ext(iph_base); | |
317 | icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); | |
318 | ||
319 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
320 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
321 | ||
322 | if (extlen) { | |
07a93626 | 323 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
324 | memcpy(&top_iph->saddr, iph_ext, extlen); |
325 | #else | |
326 | memcpy(&top_iph->daddr, iph_ext, extlen); | |
327 | #endif | |
328 | } | |
329 | ||
8631e9bd SK |
330 | kfree(AH_SKB_CB(skb)->tmp); |
331 | xfrm_output_resume(skb, err); | |
332 | } | |
333 | ||
1da177e4 LT |
334 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
335 | { | |
336 | int err; | |
8631e9bd | 337 | int nfrags; |
1da177e4 | 338 | int extlen; |
8631e9bd SK |
339 | u8 *iph_base; |
340 | u8 *icv; | |
341 | u8 nexthdr; | |
342 | struct sk_buff *trailer; | |
343 | struct crypto_ahash *ahash; | |
344 | struct ahash_request *req; | |
345 | struct scatterlist *sg; | |
1da177e4 LT |
346 | struct ipv6hdr *top_iph; |
347 | struct ip_auth_hdr *ah; | |
348 | struct ah_data *ahp; | |
8631e9bd SK |
349 | struct tmp_ext *iph_ext; |
350 | ||
351 | ahp = x->data; | |
352 | ahash = ahp->ahash; | |
353 | ||
354 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) | |
355 | goto out; | |
356 | nfrags = err; | |
1da177e4 | 357 | |
7b277b1a | 358 | skb_push(skb, -skb_network_offset(skb)); |
8631e9bd SK |
359 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
360 | if (extlen) | |
361 | extlen += sizeof(*iph_ext); | |
362 | ||
363 | err = -ENOMEM; | |
364 | iph_base = ah_alloc_tmp(ahash, nfrags, IPV6HDR_BASELEN + extlen); | |
365 | if (!iph_base) | |
366 | goto out; | |
367 | ||
368 | iph_ext = ah_tmp_ext(iph_base); | |
369 | icv = ah_tmp_icv(ahash, iph_ext, extlen); | |
370 | req = ah_tmp_req(ahash, icv); | |
371 | sg = ah_req_sg(ahash, req); | |
372 | ||
373 | ah = ip_auth_hdr(skb); | |
374 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
375 | ||
007f0211 | 376 | top_iph = ipv6_hdr(skb); |
1da177e4 LT |
377 | top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); |
378 | ||
007f0211 HX |
379 | nexthdr = *skb_mac_header(skb); |
380 | *skb_mac_header(skb) = IPPROTO_AH; | |
1da177e4 LT |
381 | |
382 | /* When there are no extension headers, we only need to save the first | |
383 | * 8 bytes of the base IP header. | |
384 | */ | |
8631e9bd | 385 | memcpy(iph_base, top_iph, IPV6HDR_BASELEN); |
1da177e4 | 386 | |
1da177e4 | 387 | if (extlen) { |
07a93626 | 388 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 389 | memcpy(iph_ext, &top_iph->saddr, extlen); |
27637df9 | 390 | #else |
8631e9bd | 391 | memcpy(iph_ext, &top_iph->daddr, extlen); |
e731c248 | 392 | #endif |
1da177e4 | 393 | err = ipv6_clear_mutable_options(top_iph, |
8631e9bd | 394 | extlen - sizeof(*iph_ext) + |
e731c248 YH |
395 | sizeof(*top_iph), |
396 | XFRM_POLICY_OUT); | |
1da177e4 | 397 | if (err) |
8631e9bd | 398 | goto out_free; |
1da177e4 LT |
399 | } |
400 | ||
1da177e4 LT |
401 | ah->nexthdr = nexthdr; |
402 | ||
403 | top_iph->priority = 0; | |
404 | top_iph->flow_lbl[0] = 0; | |
405 | top_iph->flow_lbl[1] = 0; | |
406 | top_iph->flow_lbl[2] = 0; | |
407 | top_iph->hop_limit = 0; | |
408 | ||
87bdc48d | 409 | ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; |
1da177e4 LT |
410 | |
411 | ah->reserved = 0; | |
412 | ah->spi = x->id.spi; | |
1ce3644a | 413 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
b7c6538c | 414 | |
8631e9bd SK |
415 | sg_init_table(sg, nfrags); |
416 | skb_to_sgvec(skb, sg, 0, skb->len); | |
1da177e4 | 417 | |
8631e9bd SK |
418 | ahash_request_set_crypt(req, sg, icv, skb->len); |
419 | ahash_request_set_callback(req, 0, ah6_output_done, skb); | |
420 | ||
421 | AH_SKB_CB(skb)->tmp = iph_base; | |
1da177e4 | 422 | |
8631e9bd SK |
423 | err = crypto_ahash_digest(req); |
424 | if (err) { | |
425 | if (err == -EINPROGRESS) | |
426 | goto out; | |
427 | ||
428 | if (err == -EBUSY) | |
429 | err = NET_XMIT_DROP; | |
430 | goto out_free; | |
431 | } | |
432 | ||
433 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
434 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
435 | ||
436 | if (extlen) { | |
07a93626 | 437 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 438 | memcpy(&top_iph->saddr, iph_ext, extlen); |
27637df9 | 439 | #else |
8631e9bd | 440 | memcpy(&top_iph->daddr, iph_ext, extlen); |
27637df9 | 441 | #endif |
1da177e4 LT |
442 | } |
443 | ||
8631e9bd SK |
444 | out_free: |
445 | kfree(iph_base); | |
446 | out: | |
1da177e4 LT |
447 | return err; |
448 | } | |
449 | ||
8631e9bd SK |
450 | static void ah6_input_done(struct crypto_async_request *base, int err) |
451 | { | |
452 | u8 *auth_data; | |
453 | u8 *icv; | |
454 | u8 *work_iph; | |
455 | struct sk_buff *skb = base->data; | |
456 | struct xfrm_state *x = xfrm_input_state(skb); | |
457 | struct ah_data *ahp = x->data; | |
458 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
459 | int hdr_len = skb_network_header_len(skb); | |
460 | int ah_hlen = (ah->hdrlen + 2) << 2; | |
461 | ||
462 | work_iph = AH_SKB_CB(skb)->tmp; | |
463 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
464 | icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); | |
465 | ||
466 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; | |
467 | if (err) | |
468 | goto out; | |
469 | ||
b7ea81a5 NB |
470 | err = ah->nexthdr; |
471 | ||
8631e9bd SK |
472 | skb->network_header += ah_hlen; |
473 | memcpy(skb_network_header(skb), work_iph, hdr_len); | |
474 | __skb_pull(skb, ah_hlen + hdr_len); | |
a9403f8a LR |
475 | if (x->props.mode == XFRM_MODE_TUNNEL) |
476 | skb_reset_transport_header(skb); | |
477 | else | |
478 | skb_set_transport_header(skb, -hdr_len); | |
8631e9bd SK |
479 | out: |
480 | kfree(AH_SKB_CB(skb)->tmp); | |
481 | xfrm_input_resume(skb, err); | |
482 | } | |
483 | ||
484 | ||
485 | ||
e695633e | 486 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
487 | { |
488 | /* | |
489 | * Before process AH | |
490 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] | |
491 | * |<-------------->| hdr_len | |
492 | * | |
493 | * To erase AH: | |
494 | * Keeping copy of cleared headers. After AH processing, | |
b0e380b1 ACM |
495 | * Moving the pointer of skb->network_header by using skb_pull as long |
496 | * as AH header length. Then copy back the copy as long as hdr_len | |
1da177e4 | 497 | * If destination header following AH exists, copy it into after [Ext2]. |
1ab1457c | 498 | * |
1da177e4 LT |
499 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
500 | * There is offset of AH before IPv6 header after the process. | |
501 | */ | |
502 | ||
8631e9bd SK |
503 | u8 *auth_data; |
504 | u8 *icv; | |
505 | u8 *work_iph; | |
506 | struct sk_buff *trailer; | |
507 | struct crypto_ahash *ahash; | |
508 | struct ahash_request *req; | |
509 | struct scatterlist *sg; | |
87bdc48d | 510 | struct ip_auth_hdr *ah; |
0660e03f | 511 | struct ipv6hdr *ip6h; |
1da177e4 | 512 | struct ah_data *ahp; |
1da177e4 LT |
513 | u16 hdr_len; |
514 | u16 ah_hlen; | |
515 | int nexthdr; | |
8631e9bd SK |
516 | int nfrags; |
517 | int err = -ENOMEM; | |
1da177e4 LT |
518 | |
519 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) | |
520 | goto out; | |
521 | ||
522 | /* We are going to _remove_ AH header to keep sockets happy, | |
523 | * so... Later this can change. */ | |
524 | if (skb_cloned(skb) && | |
525 | pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) | |
526 | goto out; | |
527 | ||
7aa68cb9 HX |
528 | skb->ip_summed = CHECKSUM_NONE; |
529 | ||
8631e9bd | 530 | hdr_len = skb_network_header_len(skb); |
87bdc48d | 531 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 532 | ahp = x->data; |
8631e9bd SK |
533 | ahash = ahp->ahash; |
534 | ||
1da177e4 LT |
535 | nexthdr = ah->nexthdr; |
536 | ah_hlen = (ah->hdrlen + 2) << 2; | |
537 | ||
87bdc48d HX |
538 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
539 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) | |
1ab1457c | 540 | goto out; |
1da177e4 LT |
541 | |
542 | if (!pskb_may_pull(skb, ah_hlen)) | |
543 | goto out; | |
544 | ||
8631e9bd SK |
545 | |
546 | if ((err = skb_cow_data(skb, 0, &trailer)) < 0) | |
547 | goto out; | |
548 | nfrags = err; | |
549 | ||
4b0ef1f2 DH |
550 | ah = (struct ip_auth_hdr *)skb->data; |
551 | ip6h = ipv6_hdr(skb); | |
552 | ||
553 | skb_push(skb, hdr_len); | |
554 | ||
8631e9bd SK |
555 | work_iph = ah_alloc_tmp(ahash, nfrags, hdr_len + ahp->icv_trunc_len); |
556 | if (!work_iph) | |
557 | goto out; | |
558 | ||
559 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
560 | icv = ah_tmp_icv(ahash, auth_data, ahp->icv_trunc_len); | |
561 | req = ah_tmp_req(ahash, icv); | |
562 | sg = ah_req_sg(ahash, req); | |
563 | ||
564 | memcpy(work_iph, ip6h, hdr_len); | |
565 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
566 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
567 | ||
0660e03f | 568 | if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) |
8631e9bd SK |
569 | goto out_free; |
570 | ||
0660e03f ACM |
571 | ip6h->priority = 0; |
572 | ip6h->flow_lbl[0] = 0; | |
573 | ip6h->flow_lbl[1] = 0; | |
574 | ip6h->flow_lbl[2] = 0; | |
575 | ip6h->hop_limit = 0; | |
1da177e4 | 576 | |
8631e9bd SK |
577 | sg_init_table(sg, nfrags); |
578 | skb_to_sgvec(skb, sg, 0, skb->len); | |
1da177e4 | 579 | |
8631e9bd SK |
580 | ahash_request_set_crypt(req, sg, icv, skb->len); |
581 | ahash_request_set_callback(req, 0, ah6_input_done, skb); | |
582 | ||
583 | AH_SKB_CB(skb)->tmp = work_iph; | |
584 | ||
585 | err = crypto_ahash_digest(req); | |
586 | if (err) { | |
587 | if (err == -EINPROGRESS) | |
588 | goto out; | |
589 | ||
8631e9bd | 590 | goto out_free; |
1da177e4 | 591 | } |
0ebea8ef | 592 | |
8631e9bd | 593 | err = memcmp(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG: 0; |
0ebea8ef | 594 | if (err) |
8631e9bd | 595 | goto out_free; |
1da177e4 | 596 | |
b0e380b1 | 597 | skb->network_header += ah_hlen; |
8631e9bd | 598 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
31a4ab93 | 599 | __skb_pull(skb, ah_hlen + hdr_len); |
1da177e4 | 600 | |
a9403f8a LR |
601 | if (x->props.mode == XFRM_MODE_TUNNEL) |
602 | skb_reset_transport_header(skb); | |
603 | else | |
604 | skb_set_transport_header(skb, -hdr_len); | |
605 | ||
8631e9bd | 606 | err = nexthdr; |
1da177e4 | 607 | |
8631e9bd SK |
608 | out_free: |
609 | kfree(work_iph); | |
1da177e4 | 610 | out: |
07d4ee58 | 611 | return err; |
1da177e4 LT |
612 | } |
613 | ||
1ab1457c | 614 | static void ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
d5fdd6ba | 615 | u8 type, u8 code, int offset, __be32 info) |
1da177e4 | 616 | { |
4fb236ba | 617 | struct net *net = dev_net(skb->dev); |
1da177e4 LT |
618 | struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; |
619 | struct ip_auth_hdr *ah = (struct ip_auth_hdr*)(skb->data+offset); | |
620 | struct xfrm_state *x; | |
621 | ||
622 | if (type != ICMPV6_DEST_UNREACH && | |
ec18d9a2 DM |
623 | type != ICMPV6_PKT_TOOBIG && |
624 | type != NDISC_REDIRECT) | |
1da177e4 LT |
625 | return; |
626 | ||
bd55775c | 627 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); |
1da177e4 LT |
628 | if (!x) |
629 | return; | |
630 | ||
ec18d9a2 DM |
631 | if (type == NDISC_REDIRECT) |
632 | ip6_redirect(skb, net, 0, 0); | |
633 | else | |
634 | ip6_update_pmtu(skb, net, info, 0, 0); | |
1da177e4 LT |
635 | xfrm_state_put(x); |
636 | } | |
637 | ||
72cb6962 | 638 | static int ah6_init_state(struct xfrm_state *x) |
1da177e4 LT |
639 | { |
640 | struct ah_data *ahp = NULL; | |
641 | struct xfrm_algo_desc *aalg_desc; | |
8631e9bd | 642 | struct crypto_ahash *ahash; |
1da177e4 LT |
643 | |
644 | if (!x->aalg) | |
645 | goto error; | |
646 | ||
1da177e4 LT |
647 | if (x->encap) |
648 | goto error; | |
649 | ||
0c600eda | 650 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
1da177e4 LT |
651 | if (ahp == NULL) |
652 | return -ENOMEM; | |
653 | ||
8631e9bd SK |
654 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
655 | if (IS_ERR(ahash)) | |
07d4ee58 HX |
656 | goto error; |
657 | ||
8631e9bd SK |
658 | ahp->ahash = ahash; |
659 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
bc31d3b2 | 660 | (x->aalg->alg_key_len + 7) / 8)) |
1da177e4 | 661 | goto error; |
1ab1457c | 662 | |
1da177e4 LT |
663 | /* |
664 | * Lookup the algorithm description maintained by xfrm_algo, | |
665 | * verify crypto transform properties, and store information | |
666 | * we need for AH processing. This lookup cannot fail here | |
07d4ee58 | 667 | * after a successful crypto_alloc_hash(). |
1da177e4 LT |
668 | */ |
669 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
670 | BUG_ON(!aalg_desc); | |
671 | ||
672 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
8631e9bd | 673 | crypto_ahash_digestsize(ahash)) { |
f3213831 JP |
674 | pr_info("AH: %s digestsize %u != %hu\n", |
675 | x->aalg->alg_name, crypto_ahash_digestsize(ahash), | |
676 | aalg_desc->uinfo.auth.icv_fullbits/8); | |
1da177e4 LT |
677 | goto error; |
678 | } | |
1ab1457c | 679 | |
1da177e4 | 680 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 681 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
1ab1457c | 682 | |
1da177e4 | 683 | BUG_ON(ahp->icv_trunc_len > MAX_AH_AUTH_LEN); |
1ab1457c | 684 | |
87bdc48d HX |
685 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
686 | ahp->icv_trunc_len); | |
ca68145f HX |
687 | switch (x->props.mode) { |
688 | case XFRM_MODE_BEET: | |
689 | case XFRM_MODE_TRANSPORT: | |
690 | break; | |
691 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 692 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 693 | break; |
ca68145f HX |
694 | default: |
695 | goto error; | |
696 | } | |
1da177e4 LT |
697 | x->data = ahp; |
698 | ||
699 | return 0; | |
700 | ||
701 | error: | |
702 | if (ahp) { | |
8631e9bd | 703 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
704 | kfree(ahp); |
705 | } | |
706 | return -EINVAL; | |
707 | } | |
708 | ||
709 | static void ah6_destroy(struct xfrm_state *x) | |
710 | { | |
711 | struct ah_data *ahp = x->data; | |
712 | ||
713 | if (!ahp) | |
714 | return; | |
715 | ||
8631e9bd | 716 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
717 | kfree(ahp); |
718 | } | |
719 | ||
533cb5b0 | 720 | static const struct xfrm_type ah6_type = |
1da177e4 LT |
721 | { |
722 | .description = "AH6", | |
723 | .owner = THIS_MODULE, | |
724 | .proto = IPPROTO_AH, | |
436a0a40 | 725 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
726 | .init_state = ah6_init_state, |
727 | .destructor = ah6_destroy, | |
728 | .input = ah6_input, | |
aee5adb4 MN |
729 | .output = ah6_output, |
730 | .hdr_offset = xfrm6_find_1stfragopt, | |
1da177e4 LT |
731 | }; |
732 | ||
41135cc8 | 733 | static const struct inet6_protocol ah6_protocol = { |
1da177e4 LT |
734 | .handler = xfrm6_rcv, |
735 | .err_handler = ah6_err, | |
736 | .flags = INET6_PROTO_NOPOLICY, | |
737 | }; | |
738 | ||
739 | static int __init ah6_init(void) | |
740 | { | |
741 | if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { | |
f3213831 | 742 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
743 | return -EAGAIN; |
744 | } | |
745 | ||
746 | if (inet6_add_protocol(&ah6_protocol, IPPROTO_AH) < 0) { | |
f3213831 | 747 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
748 | xfrm_unregister_type(&ah6_type, AF_INET6); |
749 | return -EAGAIN; | |
750 | } | |
751 | ||
752 | return 0; | |
753 | } | |
754 | ||
755 | static void __exit ah6_fini(void) | |
756 | { | |
757 | if (inet6_del_protocol(&ah6_protocol, IPPROTO_AH) < 0) | |
f3213831 | 758 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 LT |
759 | |
760 | if (xfrm_unregister_type(&ah6_type, AF_INET6) < 0) | |
f3213831 | 761 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
762 | |
763 | } | |
764 | ||
765 | module_init(ah6_init); | |
766 | module_exit(ah6_fini); | |
767 | ||
768 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 769 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); |