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 | ||
8631e9bd | 16 | #include <crypto/hash.h> |
c66218cc | 17 | #include <crypto/utils.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 | ||
0a6bfaa0 | 54 | len = size + crypto_ahash_digestsize(ahash); |
8631e9bd SK |
55 | |
56 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
57 | ||
58 | len += sizeof(struct ahash_request) + crypto_ahash_reqsize(ahash); | |
59 | len = ALIGN(len, __alignof__(struct scatterlist)); | |
60 | ||
61 | len += sizeof(struct scatterlist) * nfrags; | |
62 | ||
63 | return kmalloc(len, GFP_ATOMIC); | |
64 | } | |
65 | ||
66 | static inline struct tmp_ext *ah_tmp_ext(void *base) | |
67 | { | |
68 | return base + IPV6HDR_BASELEN; | |
69 | } | |
70 | ||
71 | static inline u8 *ah_tmp_auth(u8 *tmp, unsigned int offset) | |
72 | { | |
73 | return tmp + offset; | |
74 | } | |
75 | ||
0a6bfaa0 | 76 | static inline u8 *ah_tmp_icv(void *tmp, unsigned int offset) |
8631e9bd | 77 | { |
0a6bfaa0 | 78 | return tmp + offset; |
8631e9bd SK |
79 | } |
80 | ||
81 | static inline struct ahash_request *ah_tmp_req(struct crypto_ahash *ahash, | |
82 | u8 *icv) | |
83 | { | |
84 | struct ahash_request *req; | |
85 | ||
86 | req = (void *)PTR_ALIGN(icv + crypto_ahash_digestsize(ahash), | |
87 | crypto_tfm_ctx_alignment()); | |
88 | ||
89 | ahash_request_set_tfm(req, ahash); | |
90 | ||
91 | return req; | |
92 | } | |
93 | ||
94 | static inline struct scatterlist *ah_req_sg(struct crypto_ahash *ahash, | |
95 | struct ahash_request *req) | |
96 | { | |
97 | return (void *)ALIGN((unsigned long)(req + 1) + | |
98 | crypto_ahash_reqsize(ahash), | |
99 | __alignof__(struct scatterlist)); | |
100 | } | |
101 | ||
a50feda5 | 102 | static bool zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr) |
1da177e4 LT |
103 | { |
104 | u8 *opt = (u8 *)opthdr; | |
105 | int len = ipv6_optlen(opthdr); | |
106 | int off = 0; | |
107 | int optlen = 0; | |
108 | ||
109 | off += 2; | |
110 | len -= 2; | |
111 | ||
112 | while (len > 0) { | |
113 | ||
114 | switch (opt[off]) { | |
115 | ||
1de5a71c | 116 | case IPV6_TLV_PAD1: |
1da177e4 LT |
117 | optlen = 1; |
118 | break; | |
119 | default: | |
1ab1457c | 120 | if (len < 2) |
1da177e4 LT |
121 | goto bad; |
122 | optlen = opt[off+1]+2; | |
123 | if (len < optlen) | |
124 | goto bad; | |
125 | if (opt[off] & 0x20) | |
126 | memset(&opt[off+2], 0, opt[off+1]); | |
127 | break; | |
128 | } | |
129 | ||
130 | off += optlen; | |
131 | len -= optlen; | |
132 | } | |
133 | if (len == 0) | |
a50feda5 | 134 | return true; |
1da177e4 LT |
135 | |
136 | bad: | |
a50feda5 | 137 | return false; |
1da177e4 LT |
138 | } |
139 | ||
07a93626 | 140 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
27637df9 MN |
141 | /** |
142 | * ipv6_rearrange_destopt - rearrange IPv6 destination options header | |
143 | * @iph: IPv6 header | |
144 | * @destopt: destionation options header | |
145 | */ | |
146 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) | |
147 | { | |
148 | u8 *opt = (u8 *)destopt; | |
149 | int len = ipv6_optlen(destopt); | |
150 | int off = 0; | |
151 | int optlen = 0; | |
152 | ||
153 | off += 2; | |
154 | len -= 2; | |
155 | ||
156 | while (len > 0) { | |
157 | ||
158 | switch (opt[off]) { | |
159 | ||
1de5a71c | 160 | case IPV6_TLV_PAD1: |
27637df9 MN |
161 | optlen = 1; |
162 | break; | |
163 | default: | |
164 | if (len < 2) | |
165 | goto bad; | |
166 | optlen = opt[off+1]+2; | |
167 | if (len < optlen) | |
168 | goto bad; | |
169 | ||
170 | /* Rearrange the source address in @iph and the | |
171 | * addresses in home address option for final source. | |
172 | * See 11.3.2 of RFC 3775 for details. | |
173 | */ | |
174 | if (opt[off] == IPV6_TLV_HAO) { | |
27637df9 MN |
175 | struct ipv6_destopt_hao *hao; |
176 | ||
177 | hao = (struct ipv6_destopt_hao *)&opt[off]; | |
178 | if (hao->length != sizeof(hao->addr)) { | |
e87cc472 JP |
179 | net_warn_ratelimited("destopt hao: invalid header length: %u\n", |
180 | hao->length); | |
27637df9 MN |
181 | goto bad; |
182 | } | |
4cdf85ef | 183 | swap(hao->addr, iph->saddr); |
27637df9 MN |
184 | } |
185 | break; | |
186 | } | |
187 | ||
188 | off += optlen; | |
189 | len -= optlen; | |
190 | } | |
e731c248 | 191 | /* Note: ok if len == 0 */ |
27637df9 MN |
192 | bad: |
193 | return; | |
194 | } | |
136ebf08 MN |
195 | #else |
196 | static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt) {} | |
27637df9 MN |
197 | #endif |
198 | ||
1da177e4 LT |
199 | /** |
200 | * ipv6_rearrange_rthdr - rearrange IPv6 routing header | |
201 | * @iph: IPv6 header | |
202 | * @rthdr: routing header | |
203 | * | |
204 | * Rearrange the destination address in @iph and the addresses in @rthdr | |
205 | * so that they appear in the order they will at the final destination. | |
206 | * See Appendix A2 of RFC 2402 for details. | |
207 | */ | |
208 | static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr) | |
209 | { | |
210 | int segments, segments_left; | |
211 | struct in6_addr *addrs; | |
212 | struct in6_addr final_addr; | |
213 | ||
214 | segments_left = rthdr->segments_left; | |
215 | if (segments_left == 0) | |
216 | return; | |
1ab1457c | 217 | rthdr->segments_left = 0; |
1da177e4 LT |
218 | |
219 | /* The value of rthdr->hdrlen has been verified either by the system | |
220 | * call if it is locally generated, or by ipv6_rthdr_rcv() for incoming | |
221 | * packets. So we can assume that it is even and that segments is | |
222 | * greater than or equal to segments_left. | |
223 | * | |
224 | * For the same reason we can assume that this option is of type 0. | |
225 | */ | |
226 | segments = rthdr->hdrlen >> 1; | |
227 | ||
228 | addrs = ((struct rt0_hdr *)rthdr)->addr; | |
4e3fd7a0 | 229 | final_addr = addrs[segments - 1]; |
1da177e4 LT |
230 | |
231 | addrs += segments - segments_left; | |
232 | memmove(addrs + 1, addrs, (segments_left - 1) * sizeof(*addrs)); | |
233 | ||
4e3fd7a0 AD |
234 | addrs[0] = iph->daddr; |
235 | iph->daddr = final_addr; | |
1da177e4 LT |
236 | } |
237 | ||
27637df9 | 238 | static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir) |
1da177e4 LT |
239 | { |
240 | union { | |
241 | struct ipv6hdr *iph; | |
242 | struct ipv6_opt_hdr *opth; | |
243 | struct ipv6_rt_hdr *rth; | |
244 | char *raw; | |
245 | } exthdr = { .iph = iph }; | |
246 | char *end = exthdr.raw + len; | |
247 | int nexthdr = iph->nexthdr; | |
248 | ||
249 | exthdr.iph++; | |
250 | ||
251 | while (exthdr.raw < end) { | |
252 | switch (nexthdr) { | |
27637df9 MN |
253 | case NEXTHDR_DEST: |
254 | if (dir == XFRM_POLICY_OUT) | |
255 | ipv6_rearrange_destopt(iph, exthdr.opth); | |
a8eceea8 | 256 | fallthrough; |
1da177e4 | 257 | case NEXTHDR_HOP: |
1da177e4 | 258 | if (!zero_out_mutable_opts(exthdr.opth)) { |
ba7a46f1 JP |
259 | net_dbg_ratelimited("overrun %sopts\n", |
260 | nexthdr == NEXTHDR_HOP ? | |
261 | "hop" : "dest"); | |
1da177e4 LT |
262 | return -EINVAL; |
263 | } | |
264 | break; | |
265 | ||
266 | case NEXTHDR_ROUTING: | |
267 | ipv6_rearrange_rthdr(iph, exthdr.rth); | |
268 | break; | |
269 | ||
67ba4152 | 270 | default: |
1da177e4 LT |
271 | return 0; |
272 | } | |
273 | ||
274 | nexthdr = exthdr.opth->nexthdr; | |
275 | exthdr.raw += ipv6_optlen(exthdr.opth); | |
276 | } | |
277 | ||
278 | return 0; | |
279 | } | |
280 | ||
6002e20d | 281 | static void ah6_output_done(void *data, int err) |
8631e9bd SK |
282 | { |
283 | int extlen; | |
284 | u8 *iph_base; | |
285 | u8 *icv; | |
6002e20d | 286 | struct sk_buff *skb = data; |
8631e9bd SK |
287 | struct xfrm_state *x = skb_dst(skb)->xfrm; |
288 | struct ah_data *ahp = x->data; | |
289 | struct ipv6hdr *top_iph = ipv6_hdr(skb); | |
290 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
291 | struct tmp_ext *iph_ext; | |
292 | ||
293 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); | |
294 | if (extlen) | |
295 | extlen += sizeof(*iph_ext); | |
296 | ||
297 | iph_base = AH_SKB_CB(skb)->tmp; | |
298 | iph_ext = ah_tmp_ext(iph_base); | |
0a6bfaa0 | 299 | icv = ah_tmp_icv(iph_ext, extlen); |
8631e9bd SK |
300 | |
301 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
302 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
303 | ||
304 | if (extlen) { | |
07a93626 | 305 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd SK |
306 | memcpy(&top_iph->saddr, iph_ext, extlen); |
307 | #else | |
308 | memcpy(&top_iph->daddr, iph_ext, extlen); | |
309 | #endif | |
310 | } | |
311 | ||
8631e9bd | 312 | kfree(AH_SKB_CB(skb)->tmp); |
9ab1265d | 313 | xfrm_output_resume(skb->sk, skb, err); |
8631e9bd SK |
314 | } |
315 | ||
1da177e4 LT |
316 | static int ah6_output(struct xfrm_state *x, struct sk_buff *skb) |
317 | { | |
318 | int err; | |
8631e9bd | 319 | int nfrags; |
1da177e4 | 320 | int extlen; |
8631e9bd SK |
321 | u8 *iph_base; |
322 | u8 *icv; | |
323 | u8 nexthdr; | |
324 | struct sk_buff *trailer; | |
325 | struct crypto_ahash *ahash; | |
326 | struct ahash_request *req; | |
327 | struct scatterlist *sg; | |
1da177e4 LT |
328 | struct ipv6hdr *top_iph; |
329 | struct ip_auth_hdr *ah; | |
330 | struct ah_data *ahp; | |
8631e9bd | 331 | struct tmp_ext *iph_ext; |
26dd70c3 FD |
332 | int seqhi_len = 0; |
333 | __be32 *seqhi; | |
334 | int sglists = 0; | |
335 | struct scatterlist *seqhisg; | |
8631e9bd SK |
336 | |
337 | ahp = x->data; | |
338 | ahash = ahp->ahash; | |
339 | ||
e5d08d71 IM |
340 | err = skb_cow_data(skb, 0, &trailer); |
341 | if (err < 0) | |
8631e9bd SK |
342 | goto out; |
343 | nfrags = err; | |
1da177e4 | 344 | |
7b277b1a | 345 | skb_push(skb, -skb_network_offset(skb)); |
8631e9bd SK |
346 | extlen = skb_network_header_len(skb) - sizeof(struct ipv6hdr); |
347 | if (extlen) | |
348 | extlen += sizeof(*iph_ext); | |
349 | ||
26dd70c3 FD |
350 | if (x->props.flags & XFRM_STATE_ESN) { |
351 | sglists = 1; | |
352 | seqhi_len = sizeof(*seqhi); | |
353 | } | |
8631e9bd | 354 | err = -ENOMEM; |
26dd70c3 FD |
355 | iph_base = ah_alloc_tmp(ahash, nfrags + sglists, IPV6HDR_BASELEN + |
356 | extlen + seqhi_len); | |
8631e9bd SK |
357 | if (!iph_base) |
358 | goto out; | |
359 | ||
360 | iph_ext = ah_tmp_ext(iph_base); | |
26dd70c3 | 361 | seqhi = (__be32 *)((char *)iph_ext + extlen); |
0a6bfaa0 | 362 | icv = ah_tmp_icv(seqhi, seqhi_len); |
8631e9bd SK |
363 | req = ah_tmp_req(ahash, icv); |
364 | sg = ah_req_sg(ahash, req); | |
26dd70c3 | 365 | seqhisg = sg + nfrags; |
8631e9bd SK |
366 | |
367 | ah = ip_auth_hdr(skb); | |
368 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
369 | ||
007f0211 | 370 | top_iph = ipv6_hdr(skb); |
1da177e4 LT |
371 | top_iph->payload_len = htons(skb->len - sizeof(*top_iph)); |
372 | ||
007f0211 HX |
373 | nexthdr = *skb_mac_header(skb); |
374 | *skb_mac_header(skb) = IPPROTO_AH; | |
1da177e4 LT |
375 | |
376 | /* When there are no extension headers, we only need to save the first | |
377 | * 8 bytes of the base IP header. | |
378 | */ | |
8631e9bd | 379 | memcpy(iph_base, top_iph, IPV6HDR_BASELEN); |
1da177e4 | 380 | |
1da177e4 | 381 | if (extlen) { |
07a93626 | 382 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 383 | memcpy(iph_ext, &top_iph->saddr, extlen); |
27637df9 | 384 | #else |
8631e9bd | 385 | memcpy(iph_ext, &top_iph->daddr, extlen); |
e731c248 | 386 | #endif |
1da177e4 | 387 | err = ipv6_clear_mutable_options(top_iph, |
8631e9bd | 388 | extlen - sizeof(*iph_ext) + |
e731c248 YH |
389 | sizeof(*top_iph), |
390 | XFRM_POLICY_OUT); | |
1da177e4 | 391 | if (err) |
8631e9bd | 392 | goto out_free; |
1da177e4 LT |
393 | } |
394 | ||
1da177e4 LT |
395 | ah->nexthdr = nexthdr; |
396 | ||
397 | top_iph->priority = 0; | |
398 | top_iph->flow_lbl[0] = 0; | |
399 | top_iph->flow_lbl[1] = 0; | |
400 | top_iph->flow_lbl[2] = 0; | |
401 | top_iph->hop_limit = 0; | |
402 | ||
87bdc48d | 403 | ah->hdrlen = (XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len) >> 2) - 2; |
1da177e4 LT |
404 | |
405 | ah->reserved = 0; | |
406 | ah->spi = x->id.spi; | |
1ce3644a | 407 | ah->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
b7c6538c | 408 | |
26dd70c3 | 409 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
410 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
411 | if (unlikely(err < 0)) | |
412 | goto out_free; | |
1da177e4 | 413 | |
26dd70c3 FD |
414 | if (x->props.flags & XFRM_STATE_ESN) { |
415 | /* Attach seqhi sg right after packet payload */ | |
416 | *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
417 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
418 | } | |
419 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); | |
8631e9bd SK |
420 | ahash_request_set_callback(req, 0, ah6_output_done, skb); |
421 | ||
422 | AH_SKB_CB(skb)->tmp = iph_base; | |
1da177e4 | 423 | |
8631e9bd SK |
424 | err = crypto_ahash_digest(req); |
425 | if (err) { | |
426 | if (err == -EINPROGRESS) | |
427 | goto out; | |
428 | ||
068c2e70 | 429 | if (err == -ENOSPC) |
8631e9bd SK |
430 | err = NET_XMIT_DROP; |
431 | goto out_free; | |
432 | } | |
433 | ||
434 | memcpy(ah->auth_data, icv, ahp->icv_trunc_len); | |
435 | memcpy(top_iph, iph_base, IPV6HDR_BASELEN); | |
436 | ||
437 | if (extlen) { | |
07a93626 | 438 | #if IS_ENABLED(CONFIG_IPV6_MIP6) |
8631e9bd | 439 | memcpy(&top_iph->saddr, iph_ext, extlen); |
27637df9 | 440 | #else |
8631e9bd | 441 | memcpy(&top_iph->daddr, iph_ext, extlen); |
27637df9 | 442 | #endif |
1da177e4 LT |
443 | } |
444 | ||
8631e9bd SK |
445 | out_free: |
446 | kfree(iph_base); | |
447 | out: | |
1da177e4 LT |
448 | return err; |
449 | } | |
450 | ||
6002e20d | 451 | static void ah6_input_done(void *data, int err) |
8631e9bd SK |
452 | { |
453 | u8 *auth_data; | |
454 | u8 *icv; | |
455 | u8 *work_iph; | |
6002e20d | 456 | struct sk_buff *skb = data; |
8631e9bd SK |
457 | struct xfrm_state *x = xfrm_input_state(skb); |
458 | struct ah_data *ahp = x->data; | |
459 | struct ip_auth_hdr *ah = ip_auth_hdr(skb); | |
460 | int hdr_len = skb_network_header_len(skb); | |
416e8126 | 461 | int ah_hlen = ipv6_authlen(ah); |
8631e9bd | 462 | |
726282aa GBY |
463 | if (err) |
464 | goto out; | |
465 | ||
8631e9bd SK |
466 | work_iph = AH_SKB_CB(skb)->tmp; |
467 | auth_data = ah_tmp_auth(work_iph, hdr_len); | |
0a6bfaa0 | 468 | icv = ah_tmp_icv(auth_data, ahp->icv_trunc_len); |
8631e9bd | 469 | |
67df58a3 | 470 | err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
8631e9bd SK |
471 | if (err) |
472 | goto out; | |
473 | ||
b7ea81a5 NB |
474 | err = ah->nexthdr; |
475 | ||
8631e9bd SK |
476 | skb->network_header += ah_hlen; |
477 | memcpy(skb_network_header(skb), work_iph, hdr_len); | |
478 | __skb_pull(skb, ah_hlen + hdr_len); | |
a9403f8a LR |
479 | if (x->props.mode == XFRM_MODE_TUNNEL) |
480 | skb_reset_transport_header(skb); | |
481 | else | |
482 | skb_set_transport_header(skb, -hdr_len); | |
8631e9bd SK |
483 | out: |
484 | kfree(AH_SKB_CB(skb)->tmp); | |
485 | xfrm_input_resume(skb, err); | |
486 | } | |
487 | ||
488 | ||
489 | ||
e695633e | 490 | static int ah6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 LT |
491 | { |
492 | /* | |
493 | * Before process AH | |
494 | * [IPv6][Ext1][Ext2][AH][Dest][Payload] | |
495 | * |<-------------->| hdr_len | |
496 | * | |
497 | * To erase AH: | |
498 | * Keeping copy of cleared headers. After AH processing, | |
b0e380b1 ACM |
499 | * Moving the pointer of skb->network_header by using skb_pull as long |
500 | * as AH header length. Then copy back the copy as long as hdr_len | |
1da177e4 | 501 | * If destination header following AH exists, copy it into after [Ext2]. |
1ab1457c | 502 | * |
1da177e4 LT |
503 | * |<>|[IPv6][Ext1][Ext2][Dest][Payload] |
504 | * There is offset of AH before IPv6 header after the process. | |
505 | */ | |
506 | ||
8631e9bd SK |
507 | u8 *auth_data; |
508 | u8 *icv; | |
509 | u8 *work_iph; | |
510 | struct sk_buff *trailer; | |
511 | struct crypto_ahash *ahash; | |
512 | struct ahash_request *req; | |
513 | struct scatterlist *sg; | |
87bdc48d | 514 | struct ip_auth_hdr *ah; |
0660e03f | 515 | struct ipv6hdr *ip6h; |
1da177e4 | 516 | struct ah_data *ahp; |
1da177e4 LT |
517 | u16 hdr_len; |
518 | u16 ah_hlen; | |
519 | int nexthdr; | |
8631e9bd SK |
520 | int nfrags; |
521 | int err = -ENOMEM; | |
8d6da6f3 FD |
522 | int seqhi_len = 0; |
523 | __be32 *seqhi; | |
524 | int sglists = 0; | |
525 | struct scatterlist *seqhisg; | |
1da177e4 LT |
526 | |
527 | if (!pskb_may_pull(skb, sizeof(struct ip_auth_hdr))) | |
528 | goto out; | |
529 | ||
530 | /* We are going to _remove_ AH header to keep sockets happy, | |
531 | * so... Later this can change. */ | |
14bbd6a5 | 532 | if (skb_unclone(skb, GFP_ATOMIC)) |
1da177e4 LT |
533 | goto out; |
534 | ||
7aa68cb9 HX |
535 | skb->ip_summed = CHECKSUM_NONE; |
536 | ||
8631e9bd | 537 | hdr_len = skb_network_header_len(skb); |
87bdc48d | 538 | ah = (struct ip_auth_hdr *)skb->data; |
1da177e4 | 539 | ahp = x->data; |
8631e9bd SK |
540 | ahash = ahp->ahash; |
541 | ||
1da177e4 | 542 | nexthdr = ah->nexthdr; |
416e8126 | 543 | ah_hlen = ipv6_authlen(ah); |
1da177e4 | 544 | |
87bdc48d HX |
545 | if (ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_full_len) && |
546 | ah_hlen != XFRM_ALIGN8(sizeof(*ah) + ahp->icv_trunc_len)) | |
1ab1457c | 547 | goto out; |
1da177e4 LT |
548 | |
549 | if (!pskb_may_pull(skb, ah_hlen)) | |
550 | goto out; | |
551 | ||
e5d08d71 IM |
552 | err = skb_cow_data(skb, 0, &trailer); |
553 | if (err < 0) | |
8631e9bd SK |
554 | goto out; |
555 | nfrags = err; | |
556 | ||
4b0ef1f2 DH |
557 | ah = (struct ip_auth_hdr *)skb->data; |
558 | ip6h = ipv6_hdr(skb); | |
559 | ||
560 | skb_push(skb, hdr_len); | |
561 | ||
8d6da6f3 FD |
562 | if (x->props.flags & XFRM_STATE_ESN) { |
563 | sglists = 1; | |
564 | seqhi_len = sizeof(*seqhi); | |
565 | } | |
566 | ||
567 | work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len + | |
568 | ahp->icv_trunc_len + seqhi_len); | |
25105051 JL |
569 | if (!work_iph) { |
570 | err = -ENOMEM; | |
8631e9bd | 571 | goto out; |
25105051 | 572 | } |
8631e9bd | 573 | |
8d6da6f3 FD |
574 | auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len); |
575 | seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len); | |
0a6bfaa0 | 576 | icv = ah_tmp_icv(seqhi, seqhi_len); |
8631e9bd SK |
577 | req = ah_tmp_req(ahash, icv); |
578 | sg = ah_req_sg(ahash, req); | |
8d6da6f3 | 579 | seqhisg = sg + nfrags; |
8631e9bd SK |
580 | |
581 | memcpy(work_iph, ip6h, hdr_len); | |
582 | memcpy(auth_data, ah->auth_data, ahp->icv_trunc_len); | |
583 | memset(ah->auth_data, 0, ahp->icv_trunc_len); | |
584 | ||
a5ebcbdf ZC |
585 | err = ipv6_clear_mutable_options(ip6h, hdr_len, XFRM_POLICY_IN); |
586 | if (err) | |
8631e9bd SK |
587 | goto out_free; |
588 | ||
0660e03f ACM |
589 | ip6h->priority = 0; |
590 | ip6h->flow_lbl[0] = 0; | |
591 | ip6h->flow_lbl[1] = 0; | |
592 | ip6h->flow_lbl[2] = 0; | |
593 | ip6h->hop_limit = 0; | |
1da177e4 | 594 | |
8d6da6f3 | 595 | sg_init_table(sg, nfrags + sglists); |
3f297707 JD |
596 | err = skb_to_sgvec_nomark(skb, sg, 0, skb->len); |
597 | if (unlikely(err < 0)) | |
598 | goto out_free; | |
8d6da6f3 FD |
599 | |
600 | if (x->props.flags & XFRM_STATE_ESN) { | |
601 | /* Attach seqhi sg right after packet payload */ | |
602 | *seqhi = XFRM_SKB_CB(skb)->seq.input.hi; | |
603 | sg_set_buf(seqhisg, seqhi, seqhi_len); | |
604 | } | |
1da177e4 | 605 | |
8d6da6f3 | 606 | ahash_request_set_crypt(req, sg, icv, skb->len + seqhi_len); |
8631e9bd SK |
607 | ahash_request_set_callback(req, 0, ah6_input_done, skb); |
608 | ||
609 | AH_SKB_CB(skb)->tmp = work_iph; | |
610 | ||
611 | err = crypto_ahash_digest(req); | |
612 | if (err) { | |
613 | if (err == -EINPROGRESS) | |
614 | goto out; | |
615 | ||
8631e9bd | 616 | goto out_free; |
1da177e4 | 617 | } |
0ebea8ef | 618 | |
67df58a3 | 619 | err = crypto_memneq(icv, auth_data, ahp->icv_trunc_len) ? -EBADMSG : 0; |
0ebea8ef | 620 | if (err) |
8631e9bd | 621 | goto out_free; |
1da177e4 | 622 | |
b0e380b1 | 623 | skb->network_header += ah_hlen; |
8631e9bd | 624 | memcpy(skb_network_header(skb), work_iph, hdr_len); |
31a4ab93 | 625 | __skb_pull(skb, ah_hlen + hdr_len); |
1da177e4 | 626 | |
a9403f8a LR |
627 | if (x->props.mode == XFRM_MODE_TUNNEL) |
628 | skb_reset_transport_header(skb); | |
629 | else | |
630 | skb_set_transport_header(skb, -hdr_len); | |
631 | ||
8631e9bd | 632 | err = nexthdr; |
1da177e4 | 633 | |
8631e9bd SK |
634 | out_free: |
635 | kfree(work_iph); | |
1da177e4 | 636 | out: |
07d4ee58 | 637 | return err; |
1da177e4 LT |
638 | } |
639 | ||
e924d2d6 SK |
640 | static int ah6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
641 | u8 type, u8 code, int offset, __be32 info) | |
1da177e4 | 642 | { |
4fb236ba | 643 | struct net *net = dev_net(skb->dev); |
67ba4152 IM |
644 | struct ipv6hdr *iph = (struct ipv6hdr *)skb->data; |
645 | struct ip_auth_hdr *ah = (struct ip_auth_hdr *)(skb->data+offset); | |
1da177e4 LT |
646 | struct xfrm_state *x; |
647 | ||
b3b2b9e1 | 648 | if (type != ICMPV6_PKT_TOOBIG && |
ec18d9a2 | 649 | type != NDISC_REDIRECT) |
e924d2d6 | 650 | return 0; |
1da177e4 | 651 | |
bd55775c | 652 | x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr, ah->spi, IPPROTO_AH, AF_INET6); |
1da177e4 | 653 | if (!x) |
e924d2d6 | 654 | return 0; |
1da177e4 | 655 | |
ec18d9a2 | 656 | if (type == NDISC_REDIRECT) |
e2d118a1 LC |
657 | ip6_redirect(skb, net, skb->dev->ifindex, 0, |
658 | sock_net_uid(net, NULL)); | |
ec18d9a2 | 659 | else |
e2d118a1 | 660 | ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); |
1da177e4 | 661 | xfrm_state_put(x); |
e924d2d6 SK |
662 | |
663 | return 0; | |
1da177e4 LT |
664 | } |
665 | ||
e1e10b44 | 666 | static int ah6_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack) |
1da177e4 LT |
667 | { |
668 | struct ah_data *ahp = NULL; | |
669 | struct xfrm_algo_desc *aalg_desc; | |
8631e9bd | 670 | struct crypto_ahash *ahash; |
1da177e4 | 671 | |
ef87a4f8 SD |
672 | if (!x->aalg) { |
673 | NL_SET_ERR_MSG(extack, "AH requires a state with an AUTH algorithm"); | |
1da177e4 | 674 | goto error; |
ef87a4f8 | 675 | } |
1da177e4 | 676 | |
ef87a4f8 SD |
677 | if (x->encap) { |
678 | NL_SET_ERR_MSG(extack, "AH is not compatible with encapsulation"); | |
1da177e4 | 679 | goto error; |
ef87a4f8 | 680 | } |
1da177e4 | 681 | |
0c600eda | 682 | ahp = kzalloc(sizeof(*ahp), GFP_KERNEL); |
63159f29 | 683 | if (!ahp) |
1da177e4 LT |
684 | return -ENOMEM; |
685 | ||
8631e9bd | 686 | ahash = crypto_alloc_ahash(x->aalg->alg_name, 0, 0); |
ef87a4f8 SD |
687 | if (IS_ERR(ahash)) { |
688 | NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); | |
07d4ee58 | 689 | goto error; |
ef87a4f8 | 690 | } |
07d4ee58 | 691 | |
8631e9bd SK |
692 | ahp->ahash = ahash; |
693 | if (crypto_ahash_setkey(ahash, x->aalg->alg_key, | |
ef87a4f8 SD |
694 | (x->aalg->alg_key_len + 7) / 8)) { |
695 | NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); | |
1da177e4 | 696 | goto error; |
ef87a4f8 | 697 | } |
1ab1457c | 698 | |
1da177e4 LT |
699 | /* |
700 | * Lookup the algorithm description maintained by xfrm_algo, | |
701 | * verify crypto transform properties, and store information | |
702 | * we need for AH processing. This lookup cannot fail here | |
07d4ee58 | 703 | * after a successful crypto_alloc_hash(). |
1da177e4 LT |
704 | */ |
705 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); | |
706 | BUG_ON(!aalg_desc); | |
707 | ||
708 | if (aalg_desc->uinfo.auth.icv_fullbits/8 != | |
8631e9bd | 709 | crypto_ahash_digestsize(ahash)) { |
ef87a4f8 | 710 | NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations"); |
1da177e4 LT |
711 | goto error; |
712 | } | |
1ab1457c | 713 | |
1da177e4 | 714 | ahp->icv_full_len = aalg_desc->uinfo.auth.icv_fullbits/8; |
8f8a088c | 715 | ahp->icv_trunc_len = x->aalg->alg_trunc_len/8; |
1ab1457c | 716 | |
87bdc48d HX |
717 | x->props.header_len = XFRM_ALIGN8(sizeof(struct ip_auth_hdr) + |
718 | ahp->icv_trunc_len); | |
ca68145f HX |
719 | switch (x->props.mode) { |
720 | case XFRM_MODE_BEET: | |
721 | case XFRM_MODE_TRANSPORT: | |
722 | break; | |
723 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 724 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 725 | break; |
ca68145f | 726 | default: |
ef87a4f8 | 727 | NL_SET_ERR_MSG(extack, "Invalid mode requested for AH, must be one of TRANSPORT, TUNNEL, BEET"); |
ca68145f HX |
728 | goto error; |
729 | } | |
1da177e4 LT |
730 | x->data = ahp; |
731 | ||
732 | return 0; | |
733 | ||
734 | error: | |
735 | if (ahp) { | |
8631e9bd | 736 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
737 | kfree(ahp); |
738 | } | |
739 | return -EINVAL; | |
740 | } | |
741 | ||
742 | static void ah6_destroy(struct xfrm_state *x) | |
743 | { | |
744 | struct ah_data *ahp = x->data; | |
745 | ||
746 | if (!ahp) | |
747 | return; | |
748 | ||
8631e9bd | 749 | crypto_free_ahash(ahp->ahash); |
1da177e4 LT |
750 | kfree(ahp); |
751 | } | |
752 | ||
e924d2d6 SK |
753 | static int ah6_rcv_cb(struct sk_buff *skb, int err) |
754 | { | |
755 | return 0; | |
756 | } | |
757 | ||
cc24beca | 758 | static const struct xfrm_type ah6_type = { |
1da177e4 | 759 | .owner = THIS_MODULE, |
cc24beca | 760 | .proto = IPPROTO_AH, |
436a0a40 | 761 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
762 | .init_state = ah6_init_state, |
763 | .destructor = ah6_destroy, | |
764 | .input = ah6_input, | |
aee5adb4 | 765 | .output = ah6_output, |
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); |