Commit | Line | Data |
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1ccea77e | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * Copyright (C)2002 USAGI/WIDE Project | |
1ab1457c | 4 | * |
1da177e4 LT |
5 | * Authors |
6 | * | |
1ab1457c | 7 | * Mitsuru KANDA @USAGI : IPv6 Support |
67ba4152 IM |
8 | * Kazunori MIYAZAWA @USAGI : |
9 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
1ab1457c | 10 | * |
67ba4152 | 11 | * This file is derived from net/ipv4/ah.c. |
1da177e4 LT |
12 | */ |
13 | ||
f3213831 JP |
14 | #define pr_fmt(fmt) "IPv6: " fmt |
15 | ||
67df58a3 | 16 | #include <crypto/algapi.h> |
8631e9bd | 17 | #include <crypto/hash.h> |
1da177e4 | 18 | #include <linux/module.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
1da177e4 LT |
20 | #include <net/ip.h> |
21 | #include <net/ah.h> | |
22 | #include <linux/crypto.h> | |
23 | #include <linux/pfkeyv2.h> | |
24 | #include <linux/string.h> | |
8631e9bd | 25 | #include <linux/scatterlist.h> |
81aded24 | 26 | #include <net/ip6_route.h> |
1da177e4 LT |
27 | #include <net/icmp.h> |
28 | #include <net/ipv6.h> | |
14c85021 | 29 | #include <net/protocol.h> |
1da177e4 | 30 | #include <net/xfrm.h> |
1da177e4 | 31 | |
8631e9bd SK |
32 | #define IPV6HDR_BASELEN 8 |
33 | ||
34 | struct tmp_ext { | |
07a93626 | 35 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
36 | struct in6_addr saddr; |
37 | #endif | |
38 | struct in6_addr daddr; | |
b0c9a2d9 | 39 | char hdrs[]; |
8631e9bd SK |
40 | }; |
41 | ||
42 | struct ah_skb_cb { | |
43 | struct xfrm_skb_cb xfrm; | |
44 | void *tmp; | |
45 | }; | |
46 | ||
47 | #define AH_SKB_CB(__skb) ((struct ah_skb_cb *)&((__skb)->cb[0])) | |
48 | ||
49 | static void *ah_alloc_tmp(struct crypto_ahash *ahash, int nfrags, | |
50 | unsigned int size) | |
51 | { | |
52 | unsigned int len; | |
53 | ||
54 | len = size + crypto_ahash_digestsize(ahash) + | |
55 | (crypto_ahash_alignmask(ahash) & | |
56 | ~(crypto_tfm_ctx_alignment() - 1)); | |
57 | ||
58 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
59 | ||
60 | len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); | |
61 | len = ALIGN(len, __alignof__(struct scatterlist)); | |
62 | ||
63 | len += sizeof(struct scatterlist) * nfrags; | |
64 | ||
65 | return kmalloc(len, GFP_ATOMIC); | |
66 | } | |
67 | ||
68 | static inline struct tmp_ext *ah_tmp_ext(void *base) | |
69 | { | |
70 | return base + IPV6HDR_BASELEN; | |
71 | } | |
72 | ||
73 | static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) | |
74 | { | |
75 | return tmp + offset; | |
76 | } | |
77 | ||
78 | static inline u8 *ah_tmp_icv(struct crypto_ahash *ahash, void *tmp, | |
79 | unsigned int offset) | |
80 | { | |
81 | return PTR_ALIGN((u8 *)tmp + offset, crypto_ahash_alignmask(ahash) + 1); | |
82 | } | |
83 | ||
84 | static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, | |
85 | u8 *icv) | |
86 | { | |
87 | struct ahash_request *req; | |
88 | ||
89 | req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), | |
90 | crypto_tfm_ctx_alignment()); | |
91 | ||
92 | ahash_request_set_tfm(req, ahash); | |
93 | ||
94 | return req; | |
95 | } | |
96 | ||
97 | static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, | |
98 | struct ahash_request *req) | |
99 | { | |
100 | return (void *)ALIGN((unsigned long)(req + 1) + | |
101 | crypto_ahash_reqsize(ahash), | |
102 | __alignof__(struct scatterlist)); | |
103 | } | |
104 | ||
a50feda5 | 105 | static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) |
1da177e4 LT |
106 | { |
107 | u8 *opt = (u8 *)opthdr; | |
108 | int len = ipv6_optlen(opthdr); | |
109 | int off = 0; | |
110 | int optlen = 0; | |
111 | ||
112 | off += 2; | |
113 | len -= 2; | |
114 | ||
115 | while (len > 0) { | |
116 | ||
117 | switch (opt[off]) { | |
118 | ||
1de5a71c | 119 | case IPV6_TLV_PAD1: |
1da177e4 LT |
120 | optlen = 1; |
121 | break; | |
122 | default: | |
1ab1457c | 123 | if (len < 2) |
1da177e4 LT |
124 | goto bad; |
125 | optlen = opt[off+1]+2; | |
126 | if (len < optlen) | |
127 | goto bad; | |
128 | if (opt[off] & 0x20) | |
129 | memset(&opt[off+2], 0, opt[off+1]); | |
130 | break; | |
131 | } | |
132 | ||
133 | off += optlen; | |
134 | len -= optlen; | |
135 | } | |
136 | if (len == 0) | |
a50feda5 | 137 | return true; |
1da177e4 LT |
138 | |
139 | bad: | |
a50feda5 | 140 | return false; |
1da177e4 LT |
141 | } |
142 | ||
07a93626 | 143 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
27637df9 MN |
144 | /** |
145 | * ipv6_rearrange_destopt - rearrange IPv6 destination options header | |
146 | * @iph: IPv6 header | |
147 | * @destopt: destionation options header | |
148 | */ | |
149 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) | |
150 | { | |
151 | u8 *opt = (u8 *)destopt; | |
152 | int len = ipv6_optlen(destopt); | |
153 | int off = 0; | |
154 | int optlen = 0; | |
155 | ||
156 | off += 2; | |
157 | len -= 2; | |
158 | ||
159 | while (len > 0) { | |
160 | ||
161 | switch (opt[off]) { | |
162 | ||
1de5a71c | 163 | case IPV6_TLV_PAD1: |
27637df9 MN |
164 | optlen = 1; |
165 | break; | |
166 | default: | |
167 | if (len < 2) | |
168 | goto bad; | |
169 | optlen = opt[off+1]+2; | |
170 | if (len < optlen) | |
171 | goto bad; | |
172 | ||
173 | /* Rearrange the source address in @iph and the | |
174 | * addresses in home address option for final source. | |
175 | * See 11.3.2 of RFC 3775 for details. | |
176 | */ | |
177 | if (opt[off] == IPV6_TLV_HAO) { | |
27637df9 MN |
178 | struct ipv6_destopt_hao *hao; |
179 | ||
180 | hao = (struct ipv6_destopt_hao *)&opt[off]; | |
181 | if (hao->length != sizeof(hao->addr)) { | |
e87cc472 JP |
182 | net_warn_ratelimited("destopt hao: invalid header length: %u\n", |
183 | hao->length); | |
27637df9 MN |
184 | goto bad; |
185 | } | |
4cdf85ef | 186 | swap(hao->addr, iph->saddr); |
27637df9 MN |
187 | } |
188 | break; | |
189 | } | |
190 | ||
191 | off += optlen; | |
192 | len -= optlen; | |
193 | } | |
e731c248 | 194 | /* Note: ok if len == 0 */ |
27637df9 MN |
195 | bad: |
196 | return; | |
197 | } | |
136ebf08 MN |
198 | #else |
199 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} | |
27637df9 MN |
200 | #endif |
201 | ||
1da177e4 LT |
202 | /** |
203 | * ipv6_rearrange_rthdr - rearrange IPv6 routing header | |
204 | * @iph: IPv6 header | |
205 | * @rthdr: routing header | |
206 | * | |
207 | * Rearrange the destination address in @iph and the addresses in @rthdr | |
208 | * so that they appear in the order they will at the final destination. | |
209 | * See Appendix A2 of RFC 2402 for details. | |
210 | */ | |
211 | static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) | |
212 | { | |
213 | int segments, segments_left; | |
214 | struct in6_addr *addrs; | |
215 | struct in6_addr final_addr; | |
216 | ||
217 | segments_left = rthdr->segments_left; | |
218 | if (segments_left == 0) | |
219 | return; | |
1ab1457c | 220 | rthdr->segments_left = 0; |
1da177e4 LT |
221 | |
222 | /* The value of rthdr->hdrlen has been verified either by the system | |
223 | * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming | |
224 | * packets. So we can assume that it is even and that segments is | |
225 | * greater than or equal to segments_left. | |
226 | * | |
227 | * For the same reason we can assume that this option is of type 0. | |
228 | */ | |
229 | segments = rthdr->hdrlen >> 1; | |
230 | ||
231 | addrs = ((struct rt0_hdr *)rthdr)->addr; | |
4e3fd7a0 | 232 | final_addr = addrs[segments - 1]; |
1da177e4 LT |
233 | |
234 | addrs += segments - segments_left; | |
235 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); | |
236 | ||
4e3fd7a0 AD |
237 | addrs[0] = iph->daddr; |
238 | iph->daddr = final_addr; | |
1da177e4 LT |
239 | } |
240 | ||
27637df9 | 241 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
1da177e4 LT |
242 | { |
243 | union { | |
244 | struct ipv6hdr *iph; | |
245 | struct ipv6_opt_hdr *opth; | |
246 | struct ipv6_rt_hdr *rth; | |
247 | char *raw; | |
248 | } exthdr = { .iph = iph }; | |
249 | char *end = exthdr.raw + len; | |
250 | int nexthdr = iph->nexthdr; | |
251 | ||
252 | exthdr.iph++; | |
253 | ||
254 | while (exthdr.raw < end) { | |
255 | switch (nexthdr) { | |
27637df9 MN |
256 | case NEXTHDR_DEST: |
257 | if (dir == XFRM_POLICY_OUT) | |
258 | ipv6_rearrange_destopt(iph, exthdr.opth); | |
a8eceea8 | 259 | fallthrough; |
1da177e4 | 260 | case NEXTHDR_HOP: |
1da177e4 | 261 | if (!zero_out_mutable_opts(exthdr.opth)) { |
ba7a46f1 JP |
262 | net_dbg_ratelimited("overrun %sopts\n", |
263 | nexthdr == NEXTHDR_HOP ? | |
264 | "hop" : "dest"); | |
1da177e4 LT |
265 | return -EINVAL; |
266 | } | |
267 | break; | |
268 | ||
269 | case NEXTHDR_ROUTING: | |
270 | ipv6_rearrange_rthdr(iph, exthdr.rth); | |
271 | break; | |
272 | ||
67ba4152 | 273 | default: |
1da177e4 LT |
274 | return 0; |
275 | } | |
276 | ||
277 | nexthdr = exthdr.opth->nexthdr; | |
278 | exthdr.raw += ipv6_optlen(exthdr.opth); | |
279 | } | |
280 | ||
281 | return 0; | |
282 | } | |
283 | ||
8631e9bd SK |
284 | static void ah6_output_done(struct crypto_async_request *base, int err) |
285 | { | |
286 | int extlen; | |
287 | u8 *iph_base; | |
288 | u8 *icv; | |
289 | struct sk_buff *skb = base->data; | |
290 | struct xfrm_state *x = skb_dst(skb)->xfrm; | |
291 | struct ah_data *ahp = x->data; | |
292 | struct ipv6hdr *top_iph = ipv6_hdr(skb); | |
293 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
294 | struct tmp_ext *iph_ext; | |
295 | ||
296 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); | |
297 | if (extlen) | |
298 | extlen += sizeof(*iph_ext); | |
299 | ||
300 | iph_base = AH_SKB_CB(skb)->tmp; | |
301 | iph_ext = ah_tmp_ext(iph_base); | |
302 | icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); | |
303 | ||
304 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
305 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
306 | ||
307 | if (extlen) { | |
07a93626 | 308 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
309 | memcpy(&top_iph->saddr, iph_ext, extlen); |
310 | #else | |
311 | memcpy(&top_iph->daddr, iph_ext, extlen); | |
312 | #endif | |
313 | } | |
314 | ||
8631e9bd | 315 | kfree(AH_SKB_CB(skb)->tmp); |
9ab1265d | 316 | xfrm_output_resume(skb->sk, skb, err); |
8631e9bd SK |
317 | } |
318 | ||
1da177e4 LT |
319 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
320 | { | |
321 | int err; | |
8631e9bd | 322 | int nfrags; |
1da177e4 | 323 | int extlen; |
8631e9bd SK |
324 | u8 *iph_base; |
325 | u8 *icv; | |
326 | u8 nexthdr; | |
327 | struct sk_buff *trailer; | |
328 | struct crypto_ahash *ahash; | |
329 | struct ahash_request *req; | |
330 | struct scatterlist *sg; | |
1da177e4 LT |
331 | struct ipv6hdr *top_iph; |
332 | struct ip_auth_hdr *ah; | |
333 | struct ah_data *ahp; | |
8631e9bd | 334 | struct tmp_ext *iph_ext; |
26dd70c3 FD |
335 | int seqhi_len = 0; |
336 | __be32 *seqhi; | |
337 | int sglists = 0; | |
338 | struct scatterlist *seqhisg; | |
8631e9bd SK |
339 | |
340 | ahp = x->data; | |
341 | ahash = ahp->ahash; | |
342 | ||
e5d08d71 IM |
343 | err = skb_cow_data(skb, 0, &trailer); |
344 | if (err < 0) | |
8631e9bd SK |
345 | goto out; |
346 | nfrags = err; | |
1da177e4 | 347 | |
7b277b1a | 348 | skb_push(skb, -skb_network_offset(skb)); |
8631e9bd SK |
349 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
350 | if (extlen) | |
351 | extlen += sizeof(*iph_ext); | |
352 | ||
26dd70c3 FD |
353 | if (x->props.flags & XFRM_STATE_ESN) { |
354 | sglists = 1; | |
355 | seqhi_len = sizeof(*seqhi); | |
356 | } | |
8631e9bd | 357 | err = -ENOMEM; |
26dd70c3 FD |
358 | iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + |
359 | extlen + seqhi_len); | |
8631e9bd SK |
360 | if (!iph_base) |
361 | goto out; | |
362 | ||
363 | iph_ext = ah_tmp_ext(iph_base); | |
26dd70c3 FD |
364 | seqhi = (__be32 *)((char *)iph_ext + extlen); |
365 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
366 | req = ah_tmp_req(ahash, icv); |
367 | sg = ah_req_sg(ahash, req); | |
26dd70c3 | 368 | seqhisg = sg + nfrags; |
8631e9bd SK |
369 | |
370 | ah = ip_auth_hdr(skb); | |
371 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
372 | ||
007f0211 | 373 | top_iph = ipv6_hdr(skb); |
1da177e4 LT |
374 | top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); |
375 | ||
007f0211 HX |
376 | nexthdr = *skb_mac_header(skb); |
377 | *skb_mac_header(skb) = IPPROTO_AH; | |
1da177e4 LT |
378 | |
379 | /* When there are no extension headers, we only need to save the first | |
380 | * 8 bytes of the base IP header. | |
381 | */ | |
8631e9bd | 382 | memcpy(iph_base, top_iph, IPV6HDR_BASELEN); |
1da177e4 | 383 | |
1da177e4 | 384 | if (extlen) { |
07a93626 | 385 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 386 | memcpy(iph_ext, &top_iph->saddr, extlen); |
27637df9 | 387 | #else |
8631e9bd | 388 | memcpy(iph_ext, &top_iph->daddr, extlen); |
e731c248 | 389 | #endif |
1da177e4 | 390 | err = ipv6_clear_mutable_options(top_iph, |
8631e9bd | 391 | extlen - sizeof(*iph_ext) + |
e731c248 YH |
392 | sizeof(*top_iph), |
393 | XFRM_POLICY_OUT); | |
1da177e4 | 394 | if (err) |
8631e9bd | 395 | goto out_free; |
1da177e4 LT |
396 | } |
397 | ||
1da177e4 LT |
398 | ah->nexthdr = nexthdr; |
399 | ||
400 | top_iph->priority = 0; | |
401 | top_iph->flow_lbl[0] = 0; | |
402 | top_iph->flow_lbl[1] = 0; | |
403 | top_iph->flow_lbl[2] = 0; | |
404 | top_iph->hop_limit = 0; | |
405 | ||
87bdc48d | 406 | ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; |
1da177e4 LT |
407 | |
408 | ah->reserved = 0; | |
409 | ah->spi = x->id.spi; | |
1ce3644a | 410 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
b7c6538c | 411 | |
26dd70c3 | 412 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
413 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
414 | if (unlikely(err < 0)) | |
415 | goto out_free; | |
1da177e4 | 416 | |
26dd70c3 FD |
417 | if (x->props.flags & XFRM_STATE_ESN) { |
418 | /* Attach seqhi sg right after packet payload */ | |
419 | *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
420 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
421 | } | |
422 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); | |
8631e9bd SK |
423 | ahash_request_set_callback(req, 0, ah6_output_done, skb); |
424 | ||
425 | AH_SKB_CB(skb)->tmp = iph_base; | |
1da177e4 | 426 | |
8631e9bd SK |
427 | err = crypto_ahash_digest(req); |
428 | if (err) { | |
429 | if (err == -EINPROGRESS) | |
430 | goto out; | |
431 | ||
068c2e70 | 432 | if (err == -ENOSPC) |
8631e9bd SK |
433 | err = NET_XMIT_DROP; |
434 | goto out_free; | |
435 | } | |
436 | ||
437 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
438 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
439 | ||
440 | if (extlen) { | |
07a93626 | 441 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 442 | memcpy(&top_iph->saddr, iph_ext, extlen); |
27637df9 | 443 | #else |
8631e9bd | 444 | memcpy(&top_iph->daddr, iph_ext, extlen); |
27637df9 | 445 | #endif |
1da177e4 LT |
446 | } |
447 | ||
8631e9bd SK |
448 | out_free: |
449 | kfree(iph_base); | |
450 | out: | |
1da177e4 LT |
451 | return err; |
452 | } | |
453 | ||
8631e9bd SK |
454 | static void ah6_input_done(struct crypto_async_request *base, int err) |
455 | { | |
456 | u8 *auth_data; | |
457 | u8 *icv; | |
458 | u8 *work_iph; | |
459 | struct sk_buff *skb = base->data; | |
460 | struct xfrm_state *x = xfrm_input_state(skb); | |
461 | struct ah_data *ahp = x->data; | |
462 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
463 | int hdr_len = skb_network_header_len(skb); | |
416e8126 | 464 | int ah_hlen = ipv6_authlen(ah); |
8631e9bd | 465 | |
726282aa GBY |
466 | if (err) |
467 | goto out; | |
468 | ||
8631e9bd SK |
469 | work_iph = AH_SKB_CB(skb)->tmp; |
470 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
471 | icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); | |
472 | ||
67df58a3 | 473 | err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
8631e9bd SK |
474 | if (err) |
475 | goto out; | |
476 | ||
b7ea81a5 NB |
477 | err = ah->nexthdr; |
478 | ||
8631e9bd SK |
479 | skb->network_header += ah_hlen; |
480 | memcpy(skb_network_header(skb), work_iph, hdr_len); | |
481 | __skb_pull(skb, ah_hlen + hdr_len); | |
a9403f8a LR |
482 | if (x->props.mode == XFRM_MODE_TUNNEL) |
483 | skb_reset_transport_header(skb); | |
484 | else | |
485 | skb_set_transport_header(skb, -hdr_len); | |
8631e9bd SK |
486 | out: |
487 | kfree(AH_SKB_CB(skb)->tmp); | |
488 | xfrm_input_resume(skb, err); | |
489 | } | |
490 | ||
491 | ||
492 | ||
e695633e | 493 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
494 | { |
495 | /* | |
496 | * Before process AH | |
497 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] | |
498 | * |<-------------->| hdr_len | |
499 | * | |
500 | * To erase AH: | |
501 | * Keeping copy of cleared headers. After AH processing, | |
b0e380b1 ACM |
502 | * Moving the pointer of skb->network_header by using skb_pull as long |
503 | * as AH header length. Then copy back the copy as long as hdr_len | |
1da177e4 | 504 | * If destination header following AH exists, copy it into after [Ext2]. |
1ab1457c | 505 | * |
1da177e4 LT |
506 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
507 | * There is offset of AH before IPv6 header after the process. | |
508 | */ | |
509 | ||
8631e9bd SK |
510 | u8 *auth_data; |
511 | u8 *icv; | |
512 | u8 *work_iph; | |
513 | struct sk_buff *trailer; | |
514 | struct crypto_ahash *ahash; | |
515 | struct ahash_request *req; | |
516 | struct scatterlist *sg; | |
87bdc48d | 517 | struct ip_auth_hdr *ah; |
0660e03f | 518 | struct ipv6hdr *ip6h; |
1da177e4 | 519 | struct ah_data *ahp; |
1da177e4 LT |
520 | u16 hdr_len; |
521 | u16 ah_hlen; | |
522 | int nexthdr; | |
8631e9bd SK |
523 | int nfrags; |
524 | int err = -ENOMEM; | |
8d6da6f3 FD |
525 | int seqhi_len = 0; |
526 | __be32 *seqhi; | |
527 | int sglists = 0; | |
528 | struct scatterlist *seqhisg; | |
1da177e4 LT |
529 | |
530 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) | |
531 | goto out; | |
532 | ||
533 | /* We are going to _remove_ AH header to keep sockets happy, | |
534 | * so... Later this can change. */ | |
14bbd6a5 | 535 | if (skb_unclone(skb, GFP_ATOMIC)) |
1da177e4 LT |
536 | goto out; |
537 | ||
7aa68cb9 HX |
538 | skb->ip_summed = CHECKSUM_NONE; |
539 | ||
8631e9bd | 540 | hdr_len = skb_network_header_len(skb); |
87bdc48d | 541 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 542 | ahp = x->data; |
8631e9bd SK |
543 | ahash = ahp->ahash; |
544 | ||
1da177e4 | 545 | nexthdr = ah->nexthdr; |
416e8126 | 546 | ah_hlen = ipv6_authlen(ah); |
1da177e4 | 547 | |
87bdc48d HX |
548 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
549 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) | |
1ab1457c | 550 | goto out; |
1da177e4 LT |
551 | |
552 | if (!pskb_may_pull(skb, ah_hlen)) | |
553 | goto out; | |
554 | ||
e5d08d71 IM |
555 | err = skb_cow_data(skb, 0, &trailer); |
556 | if (err < 0) | |
8631e9bd SK |
557 | goto out; |
558 | nfrags = err; | |
559 | ||
4b0ef1f2 DH |
560 | ah = (struct ip_auth_hdr *)skb->data; |
561 | ip6h = ipv6_hdr(skb); | |
562 | ||
563 | skb_push(skb, hdr_len); | |
564 | ||
8d6da6f3 FD |
565 | if (x->props.flags & XFRM_STATE_ESN) { |
566 | sglists = 1; | |
567 | seqhi_len = sizeof(*seqhi); | |
568 | } | |
569 | ||
570 | work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + | |
571 | ahp->icv_trunc_len + seqhi_len); | |
25105051 JL |
572 | if (!work_iph) { |
573 | err = -ENOMEM; | |
8631e9bd | 574 | goto out; |
25105051 | 575 | } |
8631e9bd | 576 | |
8d6da6f3 FD |
577 | auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); |
578 | seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); | |
579 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
580 | req = ah_tmp_req(ahash, icv); |
581 | sg = ah_req_sg(ahash, req); | |
8d6da6f3 | 582 | seqhisg = sg + nfrags; |
8631e9bd SK |
583 | |
584 | memcpy(work_iph, ip6h, hdr_len); | |
585 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
586 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
587 | ||
a5ebcbdf ZC |
588 | err = ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN); |
589 | if (err) | |
8631e9bd SK |
590 | goto out_free; |
591 | ||
0660e03f ACM |
592 | ip6h->priority = 0; |
593 | ip6h->flow_lbl[0] = 0; | |
594 | ip6h->flow_lbl[1] = 0; | |
595 | ip6h->flow_lbl[2] = 0; | |
596 | ip6h->hop_limit = 0; | |
1da177e4 | 597 | |
8d6da6f3 | 598 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
599 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
600 | if (unlikely(err < 0)) | |
601 | goto out_free; | |
8d6da6f3 FD |
602 | |
603 | if (x->props.flags & XFRM_STATE_ESN) { | |
604 | /* Attach seqhi sg right after packet payload */ | |
605 | *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; | |
606 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
607 | } | |
1da177e4 | 608 | |
8d6da6f3 | 609 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); |
8631e9bd SK |
610 | ahash_request_set_callback(req, 0, ah6_input_done, skb); |
611 | ||
612 | AH_SKB_CB(skb)->tmp = work_iph; | |
613 | ||
614 | err = crypto_ahash_digest(req); | |
615 | if (err) { | |
616 | if (err == -EINPROGRESS) | |
617 | goto out; | |
618 | ||
8631e9bd | 619 | goto out_free; |
1da177e4 | 620 | } |
0ebea8ef | 621 | |
67df58a3 | 622 | err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
0ebea8ef | 623 | if (err) |
8631e9bd | 624 | goto out_free; |
1da177e4 | 625 | |
b0e380b1 | 626 | skb->network_header += ah_hlen; |
8631e9bd | 627 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
31a4ab93 | 628 | __skb_pull(skb, ah_hlen + hdr_len); |
1da177e4 | 629 | |
a9403f8a LR |
630 | if (x->props.mode == XFRM_MODE_TUNNEL) |
631 | skb_reset_transport_header(skb); | |
632 | else | |
633 | skb_set_transport_header(skb, -hdr_len); | |
634 | ||
8631e9bd | 635 | err = nexthdr; |
1da177e4 | 636 | |
8631e9bd SK |
637 | out_free: |
638 | kfree(work_iph); | |
1da177e4 | 639 | out: |
07d4ee58 | 640 | return err; |
1da177e4 LT |
641 | } |
642 | ||
e924d2d6 SK |
643 | static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
644 | u8 type, u8 code, int offset, __be32 info) | |
1da177e4 | 645 | { |
4fb236ba | 646 | struct net *net = dev_net(skb->dev); |
67ba4152 IM |
647 | struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; |
648 | struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); | |
1da177e4 LT |
649 | struct xfrm_state *x; |
650 | ||
b3b2b9e1 | 651 | if (type != ICMPV6_PKT_TOOBIG && |
ec18d9a2 | 652 | type != NDISC_REDIRECT) |
e924d2d6 | 653 | return 0; |
1da177e4 | 654 | |
bd55775c | 655 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); |
1da177e4 | 656 | if (!x) |
e924d2d6 | 657 | return 0; |
1da177e4 | 658 | |
ec18d9a2 | 659 | if (type == NDISC_REDIRECT) |
e2d118a1 LC |
660 | ip6_redirect(skb, net, skb->dev->ifindex, 0, |
661 | sock_net_uid(net, NULL)); | |
ec18d9a2 | 662 | else |
e2d118a1 | 663 | ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); |
1da177e4 | 664 | xfrm_state_put(x); |
e924d2d6 SK |
665 | |
666 | return 0; | |
1da177e4 LT |
667 | } |
668 | ||
72cb6962 | 669 | static int ah6_init_state(struct xfrm_state *x) |
1da177e4 LT |
670 | { |
671 | struct ah_data *ahp = NULL; | |
672 | struct xfrm_algo_desc *aalg_desc; | |
8631e9bd | 673 | struct crypto_ahash *ahash; |
1da177e4 LT |
674 | |
675 | if (!x->aalg) | |
676 | goto error; | |
677 | ||
1da177e4 LT |
678 | if (x->encap) |
679 | goto error; | |
680 | ||
0c600eda | 681 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
63159f29 | 682 | if (!ahp) |
1da177e4 LT |
683 | return -ENOMEM; |
684 | ||
8631e9bd SK |
685 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
686 | if (IS_ERR(ahash)) | |
07d4ee58 HX |
687 | goto error; |
688 | ||
8631e9bd SK |
689 | ahp->ahash = ahash; |
690 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
bc31d3b2 | 691 | (x->aalg->alg_key_len + 7) / 8)) |
1da177e4 | 692 | goto error; |
1ab1457c | 693 | |
1da177e4 LT |
694 | /* |
695 | * Lookup the algorithm description maintained by xfrm_algo, | |
696 | * verify crypto transform properties, and store information | |
697 | * we need for AH processing. This lookup cannot fail here | |
07d4ee58 | 698 | * after a successful crypto_alloc_hash(). |
1da177e4 LT |
699 | */ |
700 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
701 | BUG_ON(!aalg_desc); | |
702 | ||
703 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
8631e9bd | 704 | crypto_ahash_digestsize(ahash)) { |
6ad2dd6c | 705 | pr_info("AH: %s digestsize %u != %u\n", |
f3213831 JP |
706 | x->aalg->alg_name, crypto_ahash_digestsize(ahash), |
707 | aalg_desc->uinfo.auth.icv_fullbits/8); | |
1da177e4 LT |
708 | goto error; |
709 | } | |
1ab1457c | 710 | |
1da177e4 | 711 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 712 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
1ab1457c | 713 | |
87bdc48d HX |
714 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
715 | ahp->icv_trunc_len); | |
ca68145f HX |
716 | switch (x->props.mode) { |
717 | case XFRM_MODE_BEET: | |
718 | case XFRM_MODE_TRANSPORT: | |
719 | break; | |
720 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 721 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 722 | break; |
ca68145f HX |
723 | default: |
724 | goto error; | |
725 | } | |
1da177e4 LT |
726 | x->data = ahp; |
727 | ||
728 | return 0; | |
729 | ||
730 | error: | |
731 | if (ahp) { | |
8631e9bd | 732 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
733 | kfree(ahp); |
734 | } | |
735 | return -EINVAL; | |
736 | } | |
737 | ||
738 | static void ah6_destroy(struct xfrm_state *x) | |
739 | { | |
740 | struct ah_data *ahp = x->data; | |
741 | ||
742 | if (!ahp) | |
743 | return; | |
744 | ||
8631e9bd | 745 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
746 | kfree(ahp); |
747 | } | |
748 | ||
e924d2d6 SK |
749 | static int ah6_rcv_cb(struct sk_buff *skb, int err) |
750 | { | |
751 | return 0; | |
752 | } | |
753 | ||
cc24beca | 754 | static const struct xfrm_type ah6_type = { |
1da177e4 | 755 | .owner = THIS_MODULE, |
cc24beca | 756 | .proto = IPPROTO_AH, |
436a0a40 | 757 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
758 | .init_state = ah6_init_state, |
759 | .destructor = ah6_destroy, | |
760 | .input = ah6_input, | |
aee5adb4 | 761 | .output = ah6_output, |
1da177e4 LT |
762 | }; |
763 | ||
e924d2d6 | 764 | static struct xfrm6_protocol ah6_protocol = { |
1da177e4 | 765 | .handler = xfrm6_rcv, |
0146dca7 | 766 | .input_handler = xfrm_input, |
e924d2d6 | 767 | .cb_handler = ah6_rcv_cb, |
1da177e4 | 768 | .err_handler = ah6_err, |
e924d2d6 | 769 | .priority = 0, |
1da177e4 LT |
770 | }; |
771 | ||
772 | static int __init ah6_init(void) | |
773 | { | |
774 | if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { | |
f3213831 | 775 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
776 | return -EAGAIN; |
777 | } | |
778 | ||
e924d2d6 | 779 | if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { |
f3213831 | 780 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
781 | xfrm_unregister_type(&ah6_type, AF_INET6); |
782 | return -EAGAIN; | |
783 | } | |
784 | ||
785 | return 0; | |
786 | } | |
787 | ||
788 | static void __exit ah6_fini(void) | |
789 | { | |
e924d2d6 | 790 | if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) |
f3213831 | 791 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 792 | |
4f518e80 | 793 | xfrm_unregister_type(&ah6_type, AF_INET6); |
1da177e4 LT |
794 | } |
795 | ||
796 | module_init(ah6_init); | |
797 | module_exit(ah6_fini); | |
798 | ||
799 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 800 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_AH); |