Commit | Line | Data |
---|---|---|
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) { | |
178 | struct in6_addr final_addr; | |
179 | struct ipv6_destopt_hao *hao; | |
180 | ||
181 | hao = (struct ipv6_destopt_hao *)&opt[off]; | |
182 | if (hao->length != sizeof(hao->addr)) { | |
e87cc472 JP |
183 | net_warn_ratelimited("destopt hao: invalid header length: %u\n", |
184 | hao->length); | |
27637df9 MN |
185 | goto bad; |
186 | } | |
4e3fd7a0 AD |
187 | final_addr = hao->addr; |
188 | hao->addr = iph->saddr; | |
189 | iph->saddr = final_addr; | |
27637df9 MN |
190 | } |
191 | break; | |
192 | } | |
193 | ||
194 | off += optlen; | |
195 | len -= optlen; | |
196 | } | |
e731c248 | 197 | /* Note: ok if len == 0 */ |
27637df9 MN |
198 | bad: |
199 | return; | |
200 | } | |
136ebf08 MN |
201 | #else |
202 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} | |
27637df9 MN |
203 | #endif |
204 | ||
1da177e4 LT |
205 | /** |
206 | * ipv6_rearrange_rthdr - rearrange IPv6 routing header | |
207 | * @iph: IPv6 header | |
208 | * @rthdr: routing header | |
209 | * | |
210 | * Rearrange the destination address in @iph and the addresses in @rthdr | |
211 | * so that they appear in the order they will at the final destination. | |
212 | * See Appendix A2 of RFC 2402 for details. | |
213 | */ | |
214 | static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) | |
215 | { | |
216 | int segments, segments_left; | |
217 | struct in6_addr *addrs; | |
218 | struct in6_addr final_addr; | |
219 | ||
220 | segments_left = rthdr->segments_left; | |
221 | if (segments_left == 0) | |
222 | return; | |
1ab1457c | 223 | rthdr->segments_left = 0; |
1da177e4 LT |
224 | |
225 | /* The value of rthdr->hdrlen has been verified either by the system | |
226 | * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming | |
227 | * packets. So we can assume that it is even and that segments is | |
228 | * greater than or equal to segments_left. | |
229 | * | |
230 | * For the same reason we can assume that this option is of type 0. | |
231 | */ | |
232 | segments = rthdr->hdrlen >> 1; | |
233 | ||
234 | addrs = ((struct rt0_hdr *)rthdr)->addr; | |
4e3fd7a0 | 235 | final_addr = addrs[segments - 1]; |
1da177e4 LT |
236 | |
237 | addrs += segments - segments_left; | |
238 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); | |
239 | ||
4e3fd7a0 AD |
240 | addrs[0] = iph->daddr; |
241 | iph->daddr = final_addr; | |
1da177e4 LT |
242 | } |
243 | ||
27637df9 | 244 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
1da177e4 LT |
245 | { |
246 | union { | |
247 | struct ipv6hdr *iph; | |
248 | struct ipv6_opt_hdr *opth; | |
249 | struct ipv6_rt_hdr *rth; | |
250 | char *raw; | |
251 | } exthdr = { .iph = iph }; | |
252 | char *end = exthdr.raw + len; | |
253 | int nexthdr = iph->nexthdr; | |
254 | ||
255 | exthdr.iph++; | |
256 | ||
257 | while (exthdr.raw < end) { | |
258 | switch (nexthdr) { | |
27637df9 MN |
259 | case NEXTHDR_DEST: |
260 | if (dir == XFRM_POLICY_OUT) | |
261 | ipv6_rearrange_destopt(iph, exthdr.opth); | |
a8eceea8 | 262 | fallthrough; |
1da177e4 | 263 | case NEXTHDR_HOP: |
1da177e4 | 264 | if (!zero_out_mutable_opts(exthdr.opth)) { |
ba7a46f1 JP |
265 | net_dbg_ratelimited("overrun %sopts\n", |
266 | nexthdr == NEXTHDR_HOP ? | |
267 | "hop" : "dest"); | |
1da177e4 LT |
268 | return -EINVAL; |
269 | } | |
270 | break; | |
271 | ||
272 | case NEXTHDR_ROUTING: | |
273 | ipv6_rearrange_rthdr(iph, exthdr.rth); | |
274 | break; | |
275 | ||
67ba4152 | 276 | default: |
1da177e4 LT |
277 | return 0; |
278 | } | |
279 | ||
280 | nexthdr = exthdr.opth->nexthdr; | |
281 | exthdr.raw += ipv6_optlen(exthdr.opth); | |
282 | } | |
283 | ||
284 | return 0; | |
285 | } | |
286 | ||
8631e9bd SK |
287 | static void ah6_output_done(struct crypto_async_request *base, int err) |
288 | { | |
289 | int extlen; | |
290 | u8 *iph_base; | |
291 | u8 *icv; | |
292 | struct sk_buff *skb = base->data; | |
293 | struct xfrm_state *x = skb_dst(skb)->xfrm; | |
294 | struct ah_data *ahp = x->data; | |
295 | struct ipv6hdr *top_iph = ipv6_hdr(skb); | |
296 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
297 | struct tmp_ext *iph_ext; | |
298 | ||
299 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); | |
300 | if (extlen) | |
301 | extlen += sizeof(*iph_ext); | |
302 | ||
303 | iph_base = AH_SKB_CB(skb)->tmp; | |
304 | iph_ext = ah_tmp_ext(iph_base); | |
305 | icv = ah_tmp_icv(ahp->ahash, iph_ext, extlen); | |
306 | ||
307 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
308 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
309 | ||
310 | if (extlen) { | |
07a93626 | 311 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
312 | memcpy(&top_iph->saddr, iph_ext, extlen); |
313 | #else | |
314 | memcpy(&top_iph->daddr, iph_ext, extlen); | |
315 | #endif | |
316 | } | |
317 | ||
8631e9bd SK |
318 | kfree(AH_SKB_CB(skb)->tmp); |
319 | xfrm_output_resume(skb, err); | |
320 | } | |
321 | ||
1da177e4 LT |
322 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
323 | { | |
324 | int err; | |
8631e9bd | 325 | int nfrags; |
1da177e4 | 326 | int extlen; |
8631e9bd SK |
327 | u8 *iph_base; |
328 | u8 *icv; | |
329 | u8 nexthdr; | |
330 | struct sk_buff *trailer; | |
331 | struct crypto_ahash *ahash; | |
332 | struct ahash_request *req; | |
333 | struct scatterlist *sg; | |
1da177e4 LT |
334 | struct ipv6hdr *top_iph; |
335 | struct ip_auth_hdr *ah; | |
336 | struct ah_data *ahp; | |
8631e9bd | 337 | struct tmp_ext *iph_ext; |
26dd70c3 FD |
338 | int seqhi_len = 0; |
339 | __be32 *seqhi; | |
340 | int sglists = 0; | |
341 | struct scatterlist *seqhisg; | |
8631e9bd SK |
342 | |
343 | ahp = x->data; | |
344 | ahash = ahp->ahash; | |
345 | ||
e5d08d71 IM |
346 | err = skb_cow_data(skb, 0, &trailer); |
347 | if (err < 0) | |
8631e9bd SK |
348 | goto out; |
349 | nfrags = err; | |
1da177e4 | 350 | |
7b277b1a | 351 | skb_push(skb, -skb_network_offset(skb)); |
8631e9bd SK |
352 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
353 | if (extlen) | |
354 | extlen += sizeof(*iph_ext); | |
355 | ||
26dd70c3 FD |
356 | if (x->props.flags & XFRM_STATE_ESN) { |
357 | sglists = 1; | |
358 | seqhi_len = sizeof(*seqhi); | |
359 | } | |
8631e9bd | 360 | err = -ENOMEM; |
26dd70c3 FD |
361 | iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + |
362 | extlen + seqhi_len); | |
8631e9bd SK |
363 | if (!iph_base) |
364 | goto out; | |
365 | ||
366 | iph_ext = ah_tmp_ext(iph_base); | |
26dd70c3 FD |
367 | seqhi = (__be32 *)((char *)iph_ext + extlen); |
368 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
369 | req = ah_tmp_req(ahash, icv); |
370 | sg = ah_req_sg(ahash, req); | |
26dd70c3 | 371 | seqhisg = sg + nfrags; |
8631e9bd SK |
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 | |
26dd70c3 | 415 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
416 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
417 | if (unlikely(err < 0)) | |
418 | goto out_free; | |
1da177e4 | 419 | |
26dd70c3 FD |
420 | if (x->props.flags & XFRM_STATE_ESN) { |
421 | /* Attach seqhi sg right after packet payload */ | |
422 | *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
423 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
424 | } | |
425 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); | |
8631e9bd SK |
426 | ahash_request_set_callback(req, 0, ah6_output_done, skb); |
427 | ||
428 | AH_SKB_CB(skb)->tmp = iph_base; | |
1da177e4 | 429 | |
8631e9bd SK |
430 | err = crypto_ahash_digest(req); |
431 | if (err) { | |
432 | if (err == -EINPROGRESS) | |
433 | goto out; | |
434 | ||
068c2e70 | 435 | if (err == -ENOSPC) |
8631e9bd SK |
436 | err = NET_XMIT_DROP; |
437 | goto out_free; | |
438 | } | |
439 | ||
440 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
441 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
442 | ||
443 | if (extlen) { | |
07a93626 | 444 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 445 | memcpy(&top_iph->saddr, iph_ext, extlen); |
27637df9 | 446 | #else |
8631e9bd | 447 | memcpy(&top_iph->daddr, iph_ext, extlen); |
27637df9 | 448 | #endif |
1da177e4 LT |
449 | } |
450 | ||
8631e9bd SK |
451 | out_free: |
452 | kfree(iph_base); | |
453 | out: | |
1da177e4 LT |
454 | return err; |
455 | } | |
456 | ||
8631e9bd SK |
457 | static void ah6_input_done(struct crypto_async_request *base, int err) |
458 | { | |
459 | u8 *auth_data; | |
460 | u8 *icv; | |
461 | u8 *work_iph; | |
462 | struct sk_buff *skb = base->data; | |
463 | struct xfrm_state *x = xfrm_input_state(skb); | |
464 | struct ah_data *ahp = x->data; | |
465 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
466 | int hdr_len = skb_network_header_len(skb); | |
416e8126 | 467 | int ah_hlen = ipv6_authlen(ah); |
8631e9bd | 468 | |
726282aa GBY |
469 | if (err) |
470 | goto out; | |
471 | ||
8631e9bd SK |
472 | work_iph = AH_SKB_CB(skb)->tmp; |
473 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
474 | icv = ah_tmp_icv(ahp->ahash, auth_data, ahp->icv_trunc_len); | |
475 | ||
67df58a3 | 476 | err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
8631e9bd SK |
477 | if (err) |
478 | goto out; | |
479 | ||
b7ea81a5 NB |
480 | err = ah->nexthdr; |
481 | ||
8631e9bd SK |
482 | skb->network_header += ah_hlen; |
483 | memcpy(skb_network_header(skb), work_iph, hdr_len); | |
484 | __skb_pull(skb, ah_hlen + hdr_len); | |
a9403f8a LR |
485 | if (x->props.mode == XFRM_MODE_TUNNEL) |
486 | skb_reset_transport_header(skb); | |
487 | else | |
488 | skb_set_transport_header(skb, -hdr_len); | |
8631e9bd SK |
489 | out: |
490 | kfree(AH_SKB_CB(skb)->tmp); | |
491 | xfrm_input_resume(skb, err); | |
492 | } | |
493 | ||
494 | ||
495 | ||
e695633e | 496 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
497 | { |
498 | /* | |
499 | * Before process AH | |
500 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] | |
501 | * |<-------------->| hdr_len | |
502 | * | |
503 | * To erase AH: | |
504 | * Keeping copy of cleared headers. After AH processing, | |
b0e380b1 ACM |
505 | * Moving the pointer of skb->network_header by using skb_pull as long |
506 | * as AH header length. Then copy back the copy as long as hdr_len | |
1da177e4 | 507 | * If destination header following AH exists, copy it into after [Ext2]. |
1ab1457c | 508 | * |
1da177e4 LT |
509 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
510 | * There is offset of AH before IPv6 header after the process. | |
511 | */ | |
512 | ||
8631e9bd SK |
513 | u8 *auth_data; |
514 | u8 *icv; | |
515 | u8 *work_iph; | |
516 | struct sk_buff *trailer; | |
517 | struct crypto_ahash *ahash; | |
518 | struct ahash_request *req; | |
519 | struct scatterlist *sg; | |
87bdc48d | 520 | struct ip_auth_hdr *ah; |
0660e03f | 521 | struct ipv6hdr *ip6h; |
1da177e4 | 522 | struct ah_data *ahp; |
1da177e4 LT |
523 | u16 hdr_len; |
524 | u16 ah_hlen; | |
525 | int nexthdr; | |
8631e9bd SK |
526 | int nfrags; |
527 | int err = -ENOMEM; | |
8d6da6f3 FD |
528 | int seqhi_len = 0; |
529 | __be32 *seqhi; | |
530 | int sglists = 0; | |
531 | struct scatterlist *seqhisg; | |
1da177e4 LT |
532 | |
533 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) | |
534 | goto out; | |
535 | ||
536 | /* We are going to _remove_ AH header to keep sockets happy, | |
537 | * so... Later this can change. */ | |
14bbd6a5 | 538 | if (skb_unclone(skb, GFP_ATOMIC)) |
1da177e4 LT |
539 | goto out; |
540 | ||
7aa68cb9 HX |
541 | skb->ip_summed = CHECKSUM_NONE; |
542 | ||
8631e9bd | 543 | hdr_len = skb_network_header_len(skb); |
87bdc48d | 544 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 545 | ahp = x->data; |
8631e9bd SK |
546 | ahash = ahp->ahash; |
547 | ||
1da177e4 | 548 | nexthdr = ah->nexthdr; |
416e8126 | 549 | ah_hlen = ipv6_authlen(ah); |
1da177e4 | 550 | |
87bdc48d HX |
551 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
552 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) | |
1ab1457c | 553 | goto out; |
1da177e4 LT |
554 | |
555 | if (!pskb_may_pull(skb, ah_hlen)) | |
556 | goto out; | |
557 | ||
e5d08d71 IM |
558 | err = skb_cow_data(skb, 0, &trailer); |
559 | if (err < 0) | |
8631e9bd SK |
560 | goto out; |
561 | nfrags = err; | |
562 | ||
4b0ef1f2 DH |
563 | ah = (struct ip_auth_hdr *)skb->data; |
564 | ip6h = ipv6_hdr(skb); | |
565 | ||
566 | skb_push(skb, hdr_len); | |
567 | ||
8d6da6f3 FD |
568 | if (x->props.flags & XFRM_STATE_ESN) { |
569 | sglists = 1; | |
570 | seqhi_len = sizeof(*seqhi); | |
571 | } | |
572 | ||
573 | work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + | |
574 | ahp->icv_trunc_len + seqhi_len); | |
25105051 JL |
575 | if (!work_iph) { |
576 | err = -ENOMEM; | |
8631e9bd | 577 | goto out; |
25105051 | 578 | } |
8631e9bd | 579 | |
8d6da6f3 FD |
580 | auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); |
581 | seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); | |
582 | icv = ah_tmp_icv(ahash, seqhi, seqhi_len); | |
8631e9bd SK |
583 | req = ah_tmp_req(ahash, icv); |
584 | sg = ah_req_sg(ahash, req); | |
8d6da6f3 | 585 | seqhisg = sg + nfrags; |
8631e9bd SK |
586 | |
587 | memcpy(work_iph, ip6h, hdr_len); | |
588 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
589 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
590 | ||
0660e03f | 591 | if (ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN)) |
8631e9bd SK |
592 | goto out_free; |
593 | ||
0660e03f ACM |
594 | ip6h->priority = 0; |
595 | ip6h->flow_lbl[0] = 0; | |
596 | ip6h->flow_lbl[1] = 0; | |
597 | ip6h->flow_lbl[2] = 0; | |
598 | ip6h->hop_limit = 0; | |
1da177e4 | 599 | |
8d6da6f3 | 600 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
601 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
602 | if (unlikely(err < 0)) | |
603 | goto out_free; | |
8d6da6f3 FD |
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 | |
67df58a3 | 624 | err = crypto_memneq(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) |
e2d118a1 LC |
662 | ip6_redirect(skb, net, skb->dev->ifindex, 0, |
663 | sock_net_uid(net, NULL)); | |
ec18d9a2 | 664 | else |
e2d118a1 | 665 | ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); |
1da177e4 | 666 | xfrm_state_put(x); |
e924d2d6 SK |
667 | |
668 | return 0; | |
1da177e4 LT |
669 | } |
670 | ||
72cb6962 | 671 | static int ah6_init_state(struct xfrm_state *x) |
1da177e4 LT |
672 | { |
673 | struct ah_data *ahp = NULL; | |
674 | struct xfrm_algo_desc *aalg_desc; | |
8631e9bd | 675 | struct crypto_ahash *ahash; |
1da177e4 LT |
676 | |
677 | if (!x->aalg) | |
678 | goto error; | |
679 | ||
1da177e4 LT |
680 | if (x->encap) |
681 | goto error; | |
682 | ||
0c600eda | 683 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
63159f29 | 684 | if (!ahp) |
1da177e4 LT |
685 | return -ENOMEM; |
686 | ||
8631e9bd SK |
687 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
688 | if (IS_ERR(ahash)) | |
07d4ee58 HX |
689 | goto error; |
690 | ||
8631e9bd SK |
691 | ahp->ahash = ahash; |
692 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
bc31d3b2 | 693 | (x->aalg->alg_key_len + 7) / 8)) |
1da177e4 | 694 | goto error; |
1ab1457c | 695 | |
1da177e4 LT |
696 | /* |
697 | * Lookup the algorithm description maintained by xfrm_algo, | |
698 | * verify crypto transform properties, and store information | |
699 | * we need for AH processing. This lookup cannot fail here | |
07d4ee58 | 700 | * after a successful crypto_alloc_hash(). |
1da177e4 LT |
701 | */ |
702 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
703 | BUG_ON(!aalg_desc); | |
704 | ||
705 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
8631e9bd | 706 | crypto_ahash_digestsize(ahash)) { |
f3213831 JP |
707 | pr_info("AH: %s digestsize %u != %hu\n", |
708 | x->aalg->alg_name, crypto_ahash_digestsize(ahash), | |
709 | aalg_desc->uinfo.auth.icv_fullbits/8); | |
1da177e4 LT |
710 | goto error; |
711 | } | |
1ab1457c | 712 | |
1da177e4 | 713 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 714 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
1ab1457c | 715 | |
87bdc48d HX |
716 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
717 | ahp->icv_trunc_len); | |
ca68145f HX |
718 | switch (x->props.mode) { |
719 | case XFRM_MODE_BEET: | |
720 | case XFRM_MODE_TRANSPORT: | |
721 | break; | |
722 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 723 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 724 | break; |
ca68145f HX |
725 | default: |
726 | goto error; | |
727 | } | |
1da177e4 LT |
728 | x->data = ahp; |
729 | ||
730 | return 0; | |
731 | ||
732 | error: | |
733 | if (ahp) { | |
8631e9bd | 734 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
735 | kfree(ahp); |
736 | } | |
737 | return -EINVAL; | |
738 | } | |
739 | ||
740 | static void ah6_destroy(struct xfrm_state *x) | |
741 | { | |
742 | struct ah_data *ahp = x->data; | |
743 | ||
744 | if (!ahp) | |
745 | return; | |
746 | ||
8631e9bd | 747 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
748 | kfree(ahp); |
749 | } | |
750 | ||
e924d2d6 SK |
751 | static int ah6_rcv_cb(struct sk_buff *skb, int err) |
752 | { | |
753 | return 0; | |
754 | } | |
755 | ||
cc24beca | 756 | static const struct xfrm_type ah6_type = { |
1da177e4 LT |
757 | .description = "AH6", |
758 | .owner = THIS_MODULE, | |
cc24beca | 759 | .proto = IPPROTO_AH, |
436a0a40 | 760 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
761 | .init_state = ah6_init_state, |
762 | .destructor = ah6_destroy, | |
763 | .input = ah6_input, | |
aee5adb4 MN |
764 | .output = ah6_output, |
765 | .hdr_offset = xfrm6_find_1stfragopt, | |
1da177e4 LT |
766 | }; |
767 | ||
e924d2d6 | 768 | static struct xfrm6_protocol ah6_protocol = { |
1da177e4 | 769 | .handler = xfrm6_rcv, |
0146dca7 | 770 | .input_handler = xfrm_input, |
e924d2d6 | 771 | .cb_handler = ah6_rcv_cb, |
1da177e4 | 772 | .err_handler = ah6_err, |
e924d2d6 | 773 | .priority = 0, |
1da177e4 LT |
774 | }; |
775 | ||
776 | static int __init ah6_init(void) | |
777 | { | |
778 | if (xfrm_register_type(&ah6_type, AF_INET6) < 0) { | |
f3213831 | 779 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
780 | return -EAGAIN; |
781 | } | |
782 | ||
e924d2d6 | 783 | if (xfrm6_protocol_register(&ah6_protocol, IPPROTO_AH) < 0) { |
f3213831 | 784 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
785 | xfrm_unregister_type(&ah6_type, AF_INET6); |
786 | return -EAGAIN; | |
787 | } | |
788 | ||
789 | return 0; | |
790 | } | |
791 | ||
792 | static void __exit ah6_fini(void) | |
793 | { | |
e924d2d6 | 794 | if (xfrm6_protocol_deregister(&ah6_protocol, IPPROTO_AH) < 0) |
f3213831 | 795 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 796 | |
4f518e80 | 797 | xfrm_unregister_type(&ah6_type, AF_INET6); |
1da177e4 LT |
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); |