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 | 14 | * You should have received a copy of the GNU General Public License |
a99421d9 | 15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. |
1da177e4 LT |
16 | * |
17 | * Authors | |
18 | * | |
1ab1457c | 19 | * Mitsuru KANDA @USAGI : IPv6 Support |
67ba4152 IM |
20 | * Kazunori MIYAZAWA @USAGI : |
21 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
1ab1457c | 22 | * |
67ba4152 | 23 | * This file is derived from net/ipv4/esp.c |
1da177e4 LT |
24 | */ |
25 | ||
f3213831 JP |
26 | #define pr_fmt(fmt) "IPv6: " fmt |
27 | ||
38320c70 HX |
28 | #include <crypto/aead.h> |
29 | #include <crypto/authenc.h> | |
6b7326c8 | 30 | #include <linux/err.h> |
1da177e4 LT |
31 | #include <linux/module.h> |
32 | #include <net/ip.h> | |
33 | #include <net/xfrm.h> | |
34 | #include <net/esp.h> | |
72998d8c | 35 | #include <linux/scatterlist.h> |
a02a6422 | 36 | #include <linux/kernel.h> |
1da177e4 LT |
37 | #include <linux/pfkeyv2.h> |
38 | #include <linux/random.h> | |
38320c70 | 39 | #include <linux/slab.h> |
b7c6538c | 40 | #include <linux/spinlock.h> |
81aded24 | 41 | #include <net/ip6_route.h> |
1da177e4 LT |
42 | #include <net/icmp.h> |
43 | #include <net/ipv6.h> | |
14c85021 | 44 | #include <net/protocol.h> |
1da177e4 LT |
45 | #include <linux/icmpv6.h> |
46 | ||
03e2a30f SK |
47 | #include <linux/highmem.h> |
48 | ||
38320c70 HX |
49 | struct esp_skb_cb { |
50 | struct xfrm_skb_cb xfrm; | |
51 | void *tmp; | |
52 | }; | |
53 | ||
54 | #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0])) | |
55 | ||
040253c9 MW |
56 | static u32 esp6_get_mtu(struct xfrm_state *x, int mtu); |
57 | ||
38320c70 HX |
58 | /* |
59 | * Allocate an AEAD request structure with extra space for SG and IV. | |
60 | * | |
d212a4c2 SK |
61 | * For alignment considerations the upper 32 bits of the sequence number are |
62 | * placed at the front, if present. Followed by the IV, the request and finally | |
63 | * the SG list. | |
38320c70 HX |
64 | * |
65 | * TODO: Use spare space in skb for this where possible. | |
66 | */ | |
d212a4c2 | 67 | static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen) |
38320c70 HX |
68 | { |
69 | unsigned int len; | |
70 | ||
d212a4c2 SK |
71 | len = seqihlen; |
72 | ||
73 | len += crypto_aead_ivsize(aead); | |
74 | ||
38320c70 HX |
75 | if (len) { |
76 | len += crypto_aead_alignmask(aead) & | |
77 | ~(crypto_tfm_ctx_alignment() - 1); | |
78 | len = ALIGN(len, crypto_tfm_ctx_alignment()); | |
79 | } | |
80 | ||
000ae7b2 | 81 | len += sizeof(struct aead_request) + crypto_aead_reqsize(aead); |
38320c70 HX |
82 | len = ALIGN(len, __alignof__(struct scatterlist)); |
83 | ||
84 | len += sizeof(struct scatterlist) * nfrags; | |
85 | ||
86 | return kmalloc(len, GFP_ATOMIC); | |
87 | } | |
88 | ||
d212a4c2 SK |
89 | static inline __be32 *esp_tmp_seqhi(void *tmp) |
90 | { | |
91 | return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32)); | |
92 | } | |
93 | ||
94 | static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen) | |
38320c70 HX |
95 | { |
96 | return crypto_aead_ivsize(aead) ? | |
d212a4c2 SK |
97 | PTR_ALIGN((u8 *)tmp + seqhilen, |
98 | crypto_aead_alignmask(aead) + 1) : tmp + seqhilen; | |
38320c70 HX |
99 | } |
100 | ||
38320c70 HX |
101 | static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv) |
102 | { | |
103 | struct aead_request *req; | |
104 | ||
105 | req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead), | |
106 | crypto_tfm_ctx_alignment()); | |
107 | aead_request_set_tfm(req, aead); | |
108 | return req; | |
109 | } | |
110 | ||
111 | static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead, | |
112 | struct aead_request *req) | |
113 | { | |
114 | return (void *)ALIGN((unsigned long)(req + 1) + | |
115 | crypto_aead_reqsize(aead), | |
116 | __alignof__(struct scatterlist)); | |
117 | } | |
118 | ||
03e2a30f SK |
119 | static void esp_ssg_unref(struct xfrm_state *x, void *tmp) |
120 | { | |
03e2a30f SK |
121 | struct crypto_aead *aead = x->data; |
122 | int seqhilen = 0; | |
123 | u8 *iv; | |
124 | struct aead_request *req; | |
125 | struct scatterlist *sg; | |
126 | ||
127 | if (x->props.flags & XFRM_STATE_ESN) | |
128 | seqhilen += sizeof(__be32); | |
129 | ||
03e2a30f SK |
130 | iv = esp_tmp_iv(aead, tmp, seqhilen); |
131 | req = esp_tmp_req(aead, iv); | |
132 | ||
133 | /* Unref skb_frag_pages in the src scatterlist if necessary. | |
134 | * Skip the first sg which comes from skb->data. | |
135 | */ | |
136 | if (req->src != req->dst) | |
137 | for (sg = sg_next(req->src); sg; sg = sg_next(sg)) | |
138 | put_page(sg_page(sg)); | |
139 | } | |
140 | ||
38320c70 HX |
141 | static void esp_output_done(struct crypto_async_request *base, int err) |
142 | { | |
143 | struct sk_buff *skb = base->data; | |
f53c7239 | 144 | struct xfrm_offload *xo = xfrm_offload(skb); |
03e2a30f | 145 | void *tmp; |
f53c7239 SK |
146 | struct xfrm_state *x; |
147 | ||
148 | if (xo && (xo->flags & XFRM_DEV_RESUME)) | |
149 | x = skb->sp->xvec[skb->sp->len - 1]; | |
150 | else | |
151 | x = skb_dst(skb)->xfrm; | |
38320c70 | 152 | |
03e2a30f SK |
153 | tmp = ESP_SKB_CB(skb)->tmp; |
154 | esp_ssg_unref(x, tmp); | |
155 | kfree(tmp); | |
f53c7239 SK |
156 | |
157 | if (xo && (xo->flags & XFRM_DEV_RESUME)) { | |
158 | if (err) { | |
159 | XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR); | |
160 | kfree_skb(skb); | |
161 | return; | |
162 | } | |
163 | ||
164 | skb_push(skb, skb->data - skb_mac_header(skb)); | |
165 | secpath_reset(skb); | |
166 | xfrm_dev_resume(skb); | |
167 | } else { | |
168 | xfrm_output_resume(skb, err); | |
169 | } | |
38320c70 HX |
170 | } |
171 | ||
000ae7b2 HX |
172 | /* Move ESP header back into place. */ |
173 | static void esp_restore_header(struct sk_buff *skb, unsigned int offset) | |
174 | { | |
175 | struct ip_esp_hdr *esph = (void *)(skb->data + offset); | |
176 | void *tmp = ESP_SKB_CB(skb)->tmp; | |
177 | __be32 *seqhi = esp_tmp_seqhi(tmp); | |
178 | ||
179 | esph->seq_no = esph->spi; | |
180 | esph->spi = *seqhi; | |
181 | } | |
182 | ||
183 | static void esp_output_restore_header(struct sk_buff *skb) | |
184 | { | |
185 | esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32)); | |
186 | } | |
187 | ||
03e2a30f | 188 | static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb, |
383d0350 | 189 | struct xfrm_state *x, |
03e2a30f SK |
190 | struct ip_esp_hdr *esph, |
191 | __be32 *seqhi) | |
192 | { | |
03e2a30f SK |
193 | /* For ESN we move the header forward by 4 bytes to |
194 | * accomodate the high bits. We will move it back after | |
195 | * encryption. | |
196 | */ | |
197 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
7862b405 SK |
198 | struct xfrm_offload *xo = xfrm_offload(skb); |
199 | ||
03e2a30f SK |
200 | esph = (void *)(skb_transport_header(skb) - sizeof(__be32)); |
201 | *seqhi = esph->spi; | |
7862b405 SK |
202 | if (xo) |
203 | esph->seq_no = htonl(xo->seq.hi); | |
204 | else | |
205 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi); | |
03e2a30f SK |
206 | } |
207 | ||
208 | esph->spi = x->id.spi; | |
209 | ||
210 | return esph; | |
211 | } | |
212 | ||
000ae7b2 HX |
213 | static void esp_output_done_esn(struct crypto_async_request *base, int err) |
214 | { | |
215 | struct sk_buff *skb = base->data; | |
216 | ||
217 | esp_output_restore_header(skb); | |
218 | esp_output_done(base, err); | |
219 | } | |
220 | ||
eb758c88 SK |
221 | static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto) |
222 | { | |
223 | /* Fill padding... */ | |
224 | if (tfclen) { | |
225 | memset(tail, 0, tfclen); | |
226 | tail += tfclen; | |
227 | } | |
228 | do { | |
229 | int i; | |
230 | for (i = 0; i < plen - 2; i++) | |
231 | tail[i] = i + 1; | |
232 | } while (0); | |
233 | tail[plen - 2] = plen - 2; | |
234 | tail[plen - 1] = proto; | |
235 | } | |
236 | ||
383d0350 | 237 | int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) |
1da177e4 | 238 | { |
27a884dc | 239 | u8 *tail; |
03e2a30f | 240 | u8 *vaddr; |
383d0350 SK |
241 | int nfrags; |
242 | struct page *page; | |
383d0350 SK |
243 | struct sk_buff *trailer; |
244 | int tailen = esp->tailen; | |
d212a4c2 | 245 | |
03e2a30f | 246 | if (!skb_cloned(skb)) { |
54ffd790 | 247 | if (tailen <= skb_tailroom(skb)) { |
03e2a30f SK |
248 | nfrags = 1; |
249 | trailer = skb; | |
250 | tail = skb_tail_pointer(trailer); | |
251 | ||
252 | goto skip_cow; | |
253 | } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS) | |
254 | && !skb_has_frag_list(skb)) { | |
255 | int allocsize; | |
256 | struct sock *sk = skb->sk; | |
257 | struct page_frag *pfrag = &x->xfrag; | |
258 | ||
383d0350 SK |
259 | esp->inplace = false; |
260 | ||
03e2a30f SK |
261 | allocsize = ALIGN(tailen, L1_CACHE_BYTES); |
262 | ||
263 | spin_lock_bh(&x->lock); | |
264 | ||
265 | if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { | |
266 | spin_unlock_bh(&x->lock); | |
267 | goto cow; | |
268 | } | |
269 | ||
270 | page = pfrag->page; | |
271 | get_page(page); | |
272 | ||
273 | vaddr = kmap_atomic(page); | |
274 | ||
275 | tail = vaddr + pfrag->offset; | |
276 | ||
383d0350 | 277 | esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); |
03e2a30f SK |
278 | |
279 | kunmap_atomic(vaddr); | |
280 | ||
281 | nfrags = skb_shinfo(skb)->nr_frags; | |
282 | ||
283 | __skb_fill_page_desc(skb, nfrags, page, pfrag->offset, | |
284 | tailen); | |
285 | skb_shinfo(skb)->nr_frags = ++nfrags; | |
286 | ||
287 | pfrag->offset = pfrag->offset + allocsize; | |
36ff0dd3 SK |
288 | |
289 | spin_unlock_bh(&x->lock); | |
290 | ||
03e2a30f SK |
291 | nfrags++; |
292 | ||
293 | skb->len += tailen; | |
294 | skb->data_len += tailen; | |
295 | skb->truesize += tailen; | |
296 | if (sk) | |
14afee4b | 297 | refcount_add(tailen, &sk->sk_wmem_alloc); |
03e2a30f | 298 | |
383d0350 | 299 | goto out; |
03e2a30f | 300 | } |
48f125ce | 301 | } |
38320c70 | 302 | |
03e2a30f | 303 | cow: |
383d0350 SK |
304 | nfrags = skb_cow_data(skb, tailen, &trailer); |
305 | if (nfrags < 0) | |
306 | goto out; | |
27a884dc | 307 | tail = skb_tail_pointer(trailer); |
03e2a30f SK |
308 | |
309 | skip_cow: | |
383d0350 SK |
310 | esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto); |
311 | pskb_put(skb, trailer, tailen); | |
1da177e4 | 312 | |
383d0350 SK |
313 | out: |
314 | return nfrags; | |
315 | } | |
316 | EXPORT_SYMBOL_GPL(esp6_output_head); | |
1da177e4 | 317 | |
383d0350 SK |
318 | int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp) |
319 | { | |
320 | u8 *iv; | |
321 | int alen; | |
322 | void *tmp; | |
323 | int ivlen; | |
324 | int assoclen; | |
325 | int seqhilen; | |
326 | __be32 *seqhi; | |
327 | struct page *page; | |
328 | struct ip_esp_hdr *esph; | |
329 | struct aead_request *req; | |
330 | struct crypto_aead *aead; | |
331 | struct scatterlist *sg, *dsg; | |
332 | int err = -ENOMEM; | |
333 | ||
334 | assoclen = sizeof(struct ip_esp_hdr); | |
335 | seqhilen = 0; | |
336 | ||
337 | if (x->props.flags & XFRM_STATE_ESN) { | |
338 | seqhilen += sizeof(__be32); | |
339 | assoclen += sizeof(__be32); | |
340 | } | |
1da177e4 | 341 | |
383d0350 SK |
342 | aead = x->data; |
343 | alen = crypto_aead_authsize(aead); | |
344 | ivlen = crypto_aead_ivsize(aead); | |
345 | ||
346 | tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen); | |
e892d2d4 | 347 | if (!tmp) |
03e2a30f | 348 | goto error; |
000ae7b2 | 349 | |
03e2a30f SK |
350 | seqhi = esp_tmp_seqhi(tmp); |
351 | iv = esp_tmp_iv(aead, tmp, seqhilen); | |
352 | req = esp_tmp_req(aead, iv); | |
353 | sg = esp_req_sg(aead, req); | |
03e2a30f | 354 | |
383d0350 SK |
355 | if (esp->inplace) |
356 | dsg = sg; | |
357 | else | |
358 | dsg = &sg[esp->nfrags]; | |
359 | ||
360 | esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi); | |
000ae7b2 | 361 | |
383d0350 | 362 | sg_init_table(sg, esp->nfrags); |
3f297707 JD |
363 | err = skb_to_sgvec(skb, sg, |
364 | (unsigned char *)esph - skb->data, | |
365 | assoclen + ivlen + esp->clen + alen); | |
366 | if (unlikely(err < 0)) | |
e6194923 | 367 | goto error_free; |
383d0350 SK |
368 | |
369 | if (!esp->inplace) { | |
370 | int allocsize; | |
371 | struct page_frag *pfrag = &x->xfrag; | |
372 | ||
373 | allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES); | |
374 | ||
375 | spin_lock_bh(&x->lock); | |
376 | if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) { | |
377 | spin_unlock_bh(&x->lock); | |
e6194923 | 378 | goto error_free; |
383d0350 SK |
379 | } |
380 | ||
381 | skb_shinfo(skb)->nr_frags = 1; | |
382 | ||
383 | page = pfrag->page; | |
384 | get_page(page); | |
385 | /* replace page frags in skb with new page */ | |
386 | __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len); | |
387 | pfrag->offset = pfrag->offset + allocsize; | |
388 | spin_unlock_bh(&x->lock); | |
389 | ||
390 | sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1); | |
3f297707 JD |
391 | err = skb_to_sgvec(skb, dsg, |
392 | (unsigned char *)esph - skb->data, | |
393 | assoclen + ivlen + esp->clen + alen); | |
394 | if (unlikely(err < 0)) | |
e6194923 | 395 | goto error_free; |
383d0350 | 396 | } |
d212a4c2 | 397 | |
03e2a30f SK |
398 | if ((x->props.flags & XFRM_STATE_ESN)) |
399 | aead_request_set_callback(req, 0, esp_output_done_esn, skb); | |
400 | else | |
401 | aead_request_set_callback(req, 0, esp_output_done, skb); | |
402 | ||
383d0350 | 403 | aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv); |
000ae7b2 HX |
404 | aead_request_set_ad(req, assoclen); |
405 | ||
000ae7b2 | 406 | memset(iv, 0, ivlen); |
383d0350 | 407 | memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8), |
000ae7b2 | 408 | min(ivlen, 8)); |
1da177e4 | 409 | |
38320c70 | 410 | ESP_SKB_CB(skb)->tmp = tmp; |
000ae7b2 HX |
411 | err = crypto_aead_encrypt(req); |
412 | ||
413 | switch (err) { | |
414 | case -EINPROGRESS: | |
38320c70 | 415 | goto error; |
1da177e4 | 416 | |
068c2e70 | 417 | case -ENOSPC: |
38320c70 | 418 | err = NET_XMIT_DROP; |
000ae7b2 HX |
419 | break; |
420 | ||
421 | case 0: | |
422 | if ((x->props.flags & XFRM_STATE_ESN)) | |
423 | esp_output_restore_header(skb); | |
424 | } | |
38320c70 | 425 | |
03e2a30f SK |
426 | if (sg != dsg) |
427 | esp_ssg_unref(x, tmp); | |
38320c70 | 428 | |
e6194923 SK |
429 | error_free: |
430 | kfree(tmp); | |
38320c70 HX |
431 | error: |
432 | return err; | |
433 | } | |
383d0350 SK |
434 | EXPORT_SYMBOL_GPL(esp6_output_tail); |
435 | ||
436 | static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) | |
437 | { | |
438 | int alen; | |
439 | int blksize; | |
440 | struct ip_esp_hdr *esph; | |
441 | struct crypto_aead *aead; | |
442 | struct esp_info esp; | |
443 | ||
444 | esp.inplace = true; | |
445 | ||
446 | esp.proto = *skb_mac_header(skb); | |
447 | *skb_mac_header(skb) = IPPROTO_ESP; | |
448 | ||
449 | /* skb is pure payload to encrypt */ | |
450 | ||
451 | aead = x->data; | |
452 | alen = crypto_aead_authsize(aead); | |
453 | ||
454 | esp.tfclen = 0; | |
455 | if (x->tfcpad) { | |
456 | struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); | |
457 | u32 padto; | |
458 | ||
459 | padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached)); | |
460 | if (skb->len < padto) | |
461 | esp.tfclen = padto - skb->len; | |
462 | } | |
463 | blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
464 | esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); | |
465 | esp.plen = esp.clen - skb->len - esp.tfclen; | |
466 | esp.tailen = esp.tfclen + esp.plen + alen; | |
467 | ||
468 | esp.nfrags = esp6_output_head(x, skb, &esp); | |
469 | if (esp.nfrags < 0) | |
470 | return esp.nfrags; | |
471 | ||
472 | esph = ip_esp_hdr(skb); | |
473 | esph->spi = x->id.spi; | |
474 | ||
475 | esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); | |
476 | esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low + | |
477 | ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32)); | |
478 | ||
479 | skb_push(skb, -skb_network_offset(skb)); | |
480 | ||
481 | return esp6_output_tail(x, skb, &esp); | |
482 | } | |
38320c70 | 483 | |
47ebcc0b | 484 | static inline int esp_remove_trailer(struct sk_buff *skb) |
38320c70 HX |
485 | { |
486 | struct xfrm_state *x = xfrm_input_state(skb); | |
d77e38e6 | 487 | struct xfrm_offload *xo = xfrm_offload(skb); |
1c5ad13f | 488 | struct crypto_aead *aead = x->data; |
47ebcc0b | 489 | int alen, hlen, elen; |
e51a6472 IT |
490 | int padlen, trimlen; |
491 | __wsum csumdiff; | |
38320c70 | 492 | u8 nexthdr[2]; |
47ebcc0b | 493 | int ret; |
38320c70 | 494 | |
47ebcc0b YK |
495 | alen = crypto_aead_authsize(aead); |
496 | hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); | |
497 | elen = skb->len - hlen; | |
1da177e4 | 498 | |
47ebcc0b YK |
499 | if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) { |
500 | ret = xo->proto; | |
38320c70 | 501 | goto out; |
47ebcc0b | 502 | } |
6b7326c8 | 503 | |
eee12df5 GS |
504 | ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2); |
505 | BUG_ON(ret); | |
1da177e4 | 506 | |
47ebcc0b | 507 | ret = -EINVAL; |
38320c70 HX |
508 | padlen = nexthdr[0]; |
509 | if (padlen + 2 + alen >= elen) { | |
ba7a46f1 JP |
510 | net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n", |
511 | padlen + 2, elen - alen); | |
38320c70 | 512 | goto out; |
1da177e4 LT |
513 | } |
514 | ||
e51a6472 IT |
515 | trimlen = alen + padlen + 2; |
516 | if (skb->ip_summed == CHECKSUM_COMPLETE) { | |
517 | csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0); | |
518 | skb->csum = csum_block_sub(skb->csum, csumdiff, | |
519 | skb->len - trimlen); | |
520 | } | |
521 | pskb_trim(skb, skb->len - trimlen); | |
522 | ||
47ebcc0b YK |
523 | ret = nexthdr[1]; |
524 | ||
525 | out: | |
526 | return ret; | |
527 | } | |
528 | ||
529 | int esp6_input_done2(struct sk_buff *skb, int err) | |
530 | { | |
531 | struct xfrm_state *x = xfrm_input_state(skb); | |
532 | struct xfrm_offload *xo = xfrm_offload(skb); | |
533 | struct crypto_aead *aead = x->data; | |
534 | int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead); | |
535 | int hdr_len = skb_network_header_len(skb); | |
536 | ||
537 | if (!xo || (xo && !(xo->flags & CRYPTO_DONE))) | |
538 | kfree(ESP_SKB_CB(skb)->tmp); | |
539 | ||
540 | if (unlikely(err)) | |
541 | goto out; | |
542 | ||
543 | err = esp_remove_trailer(skb); | |
544 | if (unlikely(err < 0)) | |
545 | goto out; | |
546 | ||
547 | skb_postpull_rcsum(skb, skb_network_header(skb), | |
548 | skb_network_header_len(skb)); | |
e51a6472 | 549 | skb_pull_rcsum(skb, hlen); |
a9403f8a LR |
550 | if (x->props.mode == XFRM_MODE_TUNNEL) |
551 | skb_reset_transport_header(skb); | |
552 | else | |
553 | skb_set_transport_header(skb, -hdr_len); | |
38320c70 | 554 | |
38320c70 HX |
555 | /* RFC4303: Drop dummy packets without any error */ |
556 | if (err == IPPROTO_NONE) | |
557 | err = -EINVAL; | |
558 | ||
559 | out: | |
1da177e4 LT |
560 | return err; |
561 | } | |
383d0350 | 562 | EXPORT_SYMBOL_GPL(esp6_input_done2); |
1da177e4 | 563 | |
38320c70 HX |
564 | static void esp_input_done(struct crypto_async_request *base, int err) |
565 | { | |
566 | struct sk_buff *skb = base->data; | |
567 | ||
f1fbed0e | 568 | xfrm_input_resume(skb, esp6_input_done2(skb, err)); |
38320c70 HX |
569 | } |
570 | ||
000ae7b2 HX |
571 | static void esp_input_restore_header(struct sk_buff *skb) |
572 | { | |
573 | esp_restore_header(skb, 0); | |
574 | __skb_pull(skb, 4); | |
575 | } | |
576 | ||
03e2a30f SK |
577 | static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi) |
578 | { | |
579 | struct xfrm_state *x = xfrm_input_state(skb); | |
03e2a30f SK |
580 | |
581 | /* For ESN we move the header forward by 4 bytes to | |
582 | * accomodate the high bits. We will move it back after | |
583 | * decryption. | |
584 | */ | |
585 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
d3cc547d CIK |
586 | struct ip_esp_hdr *esph = skb_push(skb, 4); |
587 | ||
03e2a30f SK |
588 | *seqhi = esph->spi; |
589 | esph->spi = esph->seq_no; | |
590 | esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi; | |
591 | } | |
592 | } | |
593 | ||
000ae7b2 HX |
594 | static void esp_input_done_esn(struct crypto_async_request *base, int err) |
595 | { | |
596 | struct sk_buff *skb = base->data; | |
597 | ||
598 | esp_input_restore_header(skb); | |
599 | esp_input_done(base, err); | |
600 | } | |
601 | ||
e695633e | 602 | static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) |
1da177e4 | 603 | { |
87bdc48d | 604 | struct ip_esp_hdr *esph; |
1c5ad13f | 605 | struct crypto_aead *aead = x->data; |
38320c70 | 606 | struct aead_request *req; |
1da177e4 | 607 | struct sk_buff *trailer; |
000ae7b2 HX |
608 | int ivlen = crypto_aead_ivsize(aead); |
609 | int elen = skb->len - sizeof(*esph) - ivlen; | |
1da177e4 | 610 | int nfrags; |
d212a4c2 | 611 | int assoclen; |
d212a4c2 | 612 | int seqhilen; |
1da177e4 | 613 | int ret = 0; |
38320c70 | 614 | void *tmp; |
d212a4c2 | 615 | __be32 *seqhi; |
38320c70 HX |
616 | u8 *iv; |
617 | struct scatterlist *sg; | |
1da177e4 | 618 | |
000ae7b2 | 619 | if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) { |
1da177e4 | 620 | ret = -EINVAL; |
31a4ab93 | 621 | goto out; |
1da177e4 LT |
622 | } |
623 | ||
38320c70 | 624 | if (elen <= 0) { |
1da177e4 | 625 | ret = -EINVAL; |
31a4ab93 | 626 | goto out; |
1da177e4 | 627 | } |
1da177e4 | 628 | |
d212a4c2 | 629 | assoclen = sizeof(*esph); |
d212a4c2 SK |
630 | seqhilen = 0; |
631 | ||
632 | if (x->props.flags & XFRM_STATE_ESN) { | |
d212a4c2 SK |
633 | seqhilen += sizeof(__be32); |
634 | assoclen += seqhilen; | |
635 | } | |
636 | ||
03e2a30f SK |
637 | if (!skb_cloned(skb)) { |
638 | if (!skb_is_nonlinear(skb)) { | |
639 | nfrags = 1; | |
640 | ||
641 | goto skip_cow; | |
642 | } else if (!skb_has_frag_list(skb)) { | |
643 | nfrags = skb_shinfo(skb)->nr_frags; | |
644 | nfrags++; | |
645 | ||
646 | goto skip_cow; | |
647 | } | |
648 | } | |
649 | ||
650 | nfrags = skb_cow_data(skb, 0, &trailer); | |
651 | if (nfrags < 0) { | |
652 | ret = -EINVAL; | |
653 | goto out; | |
654 | } | |
655 | ||
656 | skip_cow: | |
657 | ret = -ENOMEM; | |
000ae7b2 | 658 | tmp = esp_alloc_tmp(aead, nfrags, seqhilen); |
38320c70 HX |
659 | if (!tmp) |
660 | goto out; | |
1da177e4 | 661 | |
38320c70 | 662 | ESP_SKB_CB(skb)->tmp = tmp; |
d212a4c2 SK |
663 | seqhi = esp_tmp_seqhi(tmp); |
664 | iv = esp_tmp_iv(aead, tmp, seqhilen); | |
38320c70 | 665 | req = esp_tmp_req(aead, iv); |
000ae7b2 | 666 | sg = esp_req_sg(aead, req); |
1da177e4 | 667 | |
03e2a30f | 668 | esp_input_set_header(skb, seqhi); |
1da177e4 | 669 | |
03e2a30f | 670 | sg_init_table(sg, nfrags); |
3f297707 JD |
671 | ret = skb_to_sgvec(skb, sg, 0, skb->len); |
672 | if (unlikely(ret < 0)) | |
673 | goto out; | |
1da177e4 | 674 | |
03e2a30f | 675 | skb->ip_summed = CHECKSUM_NONE; |
d212a4c2 | 676 | |
03e2a30f | 677 | if ((x->props.flags & XFRM_STATE_ESN)) |
000ae7b2 | 678 | aead_request_set_callback(req, 0, esp_input_done_esn, skb); |
03e2a30f SK |
679 | else |
680 | aead_request_set_callback(req, 0, esp_input_done, skb); | |
000ae7b2 HX |
681 | |
682 | aead_request_set_crypt(req, sg, sg, elen + ivlen, iv); | |
683 | aead_request_set_ad(req, assoclen); | |
1da177e4 | 684 | |
38320c70 HX |
685 | ret = crypto_aead_decrypt(req); |
686 | if (ret == -EINPROGRESS) | |
687 | goto out; | |
95a02cfd | 688 | |
000ae7b2 HX |
689 | if ((x->props.flags & XFRM_STATE_ESN)) |
690 | esp_input_restore_header(skb); | |
691 | ||
f1fbed0e | 692 | ret = esp6_input_done2(skb, ret); |
1da177e4 LT |
693 | |
694 | out: | |
1da177e4 LT |
695 | return ret; |
696 | } | |
697 | ||
c5c25238 | 698 | static u32 esp6_get_mtu(struct xfrm_state *x, int mtu) |
1da177e4 | 699 | { |
1c5ad13f MK |
700 | struct crypto_aead *aead = x->data; |
701 | u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4); | |
91657eaf | 702 | unsigned int net_adj; |
1da177e4 | 703 | |
91657eaf BP |
704 | if (x->props.mode != XFRM_MODE_TUNNEL) |
705 | net_adj = sizeof(struct ipv6hdr); | |
706 | else | |
707 | net_adj = 0; | |
c5c25238 | 708 | |
1c5ad13f | 709 | return ((mtu - x->props.header_len - crypto_aead_authsize(aead) - |
123b0d1b | 710 | net_adj) & ~(blksize - 1)) + net_adj - 2; |
1da177e4 LT |
711 | } |
712 | ||
d5860c5c SK |
713 | static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
714 | u8 type, u8 code, int offset, __be32 info) | |
1da177e4 | 715 | { |
4fb236ba | 716 | struct net *net = dev_net(skb->dev); |
b71d1d42 | 717 | const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; |
87bdc48d | 718 | struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset); |
1da177e4 LT |
719 | struct xfrm_state *x; |
720 | ||
b3b2b9e1 | 721 | if (type != ICMPV6_PKT_TOOBIG && |
ec18d9a2 | 722 | type != NDISC_REDIRECT) |
d5860c5c | 723 | return 0; |
1da177e4 | 724 | |
b71d1d42 ED |
725 | x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr, |
726 | esph->spi, IPPROTO_ESP, AF_INET6); | |
1da177e4 | 727 | if (!x) |
d5860c5c | 728 | return 0; |
ec18d9a2 DM |
729 | |
730 | if (type == NDISC_REDIRECT) | |
e2d118a1 LC |
731 | ip6_redirect(skb, net, skb->dev->ifindex, 0, |
732 | sock_net_uid(net, NULL)); | |
ec18d9a2 | 733 | else |
e2d118a1 | 734 | ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); |
1da177e4 | 735 | xfrm_state_put(x); |
d5860c5c SK |
736 | |
737 | return 0; | |
1da177e4 LT |
738 | } |
739 | ||
740 | static void esp6_destroy(struct xfrm_state *x) | |
741 | { | |
1c5ad13f | 742 | struct crypto_aead *aead = x->data; |
1da177e4 | 743 | |
1c5ad13f | 744 | if (!aead) |
1da177e4 LT |
745 | return; |
746 | ||
1c5ad13f | 747 | crypto_free_aead(aead); |
1da177e4 LT |
748 | } |
749 | ||
1a6509d9 HX |
750 | static int esp_init_aead(struct xfrm_state *x) |
751 | { | |
000ae7b2 | 752 | char aead_name[CRYPTO_MAX_ALG_NAME]; |
1a6509d9 HX |
753 | struct crypto_aead *aead; |
754 | int err; | |
b3859c8e | 755 | u32 mask = 0; |
1a6509d9 | 756 | |
000ae7b2 HX |
757 | err = -ENAMETOOLONG; |
758 | if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", | |
759 | x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) | |
760 | goto error; | |
761 | ||
b3859c8e SK |
762 | if (x->xso.offload_handle) |
763 | mask |= CRYPTO_ALG_ASYNC; | |
764 | ||
765 | aead = crypto_alloc_aead(aead_name, 0, mask); | |
1a6509d9 HX |
766 | err = PTR_ERR(aead); |
767 | if (IS_ERR(aead)) | |
768 | goto error; | |
769 | ||
1c5ad13f | 770 | x->data = aead; |
1a6509d9 HX |
771 | |
772 | err = crypto_aead_setkey(aead, x->aead->alg_key, | |
773 | (x->aead->alg_key_len + 7) / 8); | |
774 | if (err) | |
775 | goto error; | |
776 | ||
777 | err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8); | |
778 | if (err) | |
779 | goto error; | |
780 | ||
781 | error: | |
782 | return err; | |
783 | } | |
784 | ||
785 | static int esp_init_authenc(struct xfrm_state *x) | |
1da177e4 | 786 | { |
38320c70 HX |
787 | struct crypto_aead *aead; |
788 | struct crypto_authenc_key_param *param; | |
789 | struct rtattr *rta; | |
790 | char *key; | |
791 | char *p; | |
792 | char authenc_name[CRYPTO_MAX_ALG_NAME]; | |
38320c70 HX |
793 | unsigned int keylen; |
794 | int err; | |
b3859c8e | 795 | u32 mask = 0; |
1da177e4 | 796 | |
1a6509d9 | 797 | err = -EINVAL; |
63159f29 | 798 | if (!x->ealg) |
1a6509d9 | 799 | goto error; |
38320c70 | 800 | |
1a6509d9 | 801 | err = -ENAMETOOLONG; |
d212a4c2 SK |
802 | |
803 | if ((x->props.flags & XFRM_STATE_ESN)) { | |
804 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
000ae7b2 HX |
805 | "%s%sauthencesn(%s,%s)%s", |
806 | x->geniv ?: "", x->geniv ? "(" : "", | |
d212a4c2 | 807 | x->aalg ? x->aalg->alg_name : "digest_null", |
000ae7b2 HX |
808 | x->ealg->alg_name, |
809 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
d212a4c2 SK |
810 | goto error; |
811 | } else { | |
812 | if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME, | |
000ae7b2 HX |
813 | "%s%sauthenc(%s,%s)%s", |
814 | x->geniv ?: "", x->geniv ? "(" : "", | |
d212a4c2 | 815 | x->aalg ? x->aalg->alg_name : "digest_null", |
000ae7b2 HX |
816 | x->ealg->alg_name, |
817 | x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) | |
d212a4c2 SK |
818 | goto error; |
819 | } | |
38320c70 | 820 | |
b3859c8e SK |
821 | if (x->xso.offload_handle) |
822 | mask |= CRYPTO_ALG_ASYNC; | |
823 | ||
824 | aead = crypto_alloc_aead(authenc_name, 0, mask); | |
38320c70 HX |
825 | err = PTR_ERR(aead); |
826 | if (IS_ERR(aead)) | |
827 | goto error; | |
828 | ||
1c5ad13f | 829 | x->data = aead; |
38320c70 HX |
830 | |
831 | keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) + | |
832 | (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param)); | |
833 | err = -ENOMEM; | |
834 | key = kmalloc(keylen, GFP_KERNEL); | |
835 | if (!key) | |
836 | goto error; | |
837 | ||
838 | p = key; | |
839 | rta = (void *)p; | |
840 | rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; | |
841 | rta->rta_len = RTA_LENGTH(sizeof(*param)); | |
842 | param = RTA_DATA(rta); | |
843 | p += RTA_SPACE(sizeof(*param)); | |
844 | ||
1da177e4 LT |
845 | if (x->aalg) { |
846 | struct xfrm_algo_desc *aalg_desc; | |
847 | ||
38320c70 HX |
848 | memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8); |
849 | p += (x->aalg->alg_key_len + 7) / 8; | |
1ab1457c | 850 | |
1da177e4 LT |
851 | aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0); |
852 | BUG_ON(!aalg_desc); | |
1ab1457c | 853 | |
38320c70 | 854 | err = -EINVAL; |
45083497 | 855 | if (aalg_desc->uinfo.auth.icv_fullbits / 8 != |
38320c70 | 856 | crypto_aead_authsize(aead)) { |
45083497 JP |
857 | pr_info("ESP: %s digestsize %u != %hu\n", |
858 | x->aalg->alg_name, | |
859 | crypto_aead_authsize(aead), | |
860 | aalg_desc->uinfo.auth.icv_fullbits / 8); | |
38320c70 | 861 | goto free_key; |
1da177e4 | 862 | } |
1ab1457c | 863 | |
38320c70 | 864 | err = crypto_aead_setauthsize( |
8f8a088c | 865 | aead, x->aalg->alg_trunc_len / 8); |
38320c70 HX |
866 | if (err) |
867 | goto free_key; | |
1da177e4 | 868 | } |
38320c70 | 869 | |
38320c70 HX |
870 | param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8); |
871 | memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8); | |
872 | ||
873 | err = crypto_aead_setkey(aead, key, keylen); | |
874 | ||
875 | free_key: | |
876 | kfree(key); | |
877 | ||
1a6509d9 HX |
878 | error: |
879 | return err; | |
880 | } | |
881 | ||
882 | static int esp6_init_state(struct xfrm_state *x) | |
883 | { | |
1a6509d9 HX |
884 | struct crypto_aead *aead; |
885 | u32 align; | |
886 | int err; | |
887 | ||
888 | if (x->encap) | |
889 | return -EINVAL; | |
890 | ||
1c5ad13f | 891 | x->data = NULL; |
1a6509d9 HX |
892 | |
893 | if (x->aead) | |
894 | err = esp_init_aead(x); | |
895 | else | |
896 | err = esp_init_authenc(x); | |
897 | ||
38320c70 | 898 | if (err) |
1da177e4 | 899 | goto error; |
38320c70 | 900 | |
1c5ad13f | 901 | aead = x->data; |
1a6509d9 | 902 | |
38320c70 HX |
903 | x->props.header_len = sizeof(struct ip_esp_hdr) + |
904 | crypto_aead_ivsize(aead); | |
ca68145f HX |
905 | switch (x->props.mode) { |
906 | case XFRM_MODE_BEET: | |
abf5cdb8 JK |
907 | if (x->sel.family != AF_INET6) |
908 | x->props.header_len += IPV4_BEET_PHMAXLEN + | |
67ba4152 | 909 | (sizeof(struct ipv6hdr) - sizeof(struct iphdr)); |
abf5cdb8 | 910 | break; |
ca68145f HX |
911 | case XFRM_MODE_TRANSPORT: |
912 | break; | |
913 | case XFRM_MODE_TUNNEL: | |
1da177e4 | 914 | x->props.header_len += sizeof(struct ipv6hdr); |
ea2c47b4 | 915 | break; |
ca68145f HX |
916 | default: |
917 | goto error; | |
918 | } | |
38320c70 HX |
919 | |
920 | align = ALIGN(crypto_aead_blocksize(aead), 4); | |
1c5ad13f | 921 | x->props.trailer_len = align + 1 + crypto_aead_authsize(aead); |
1da177e4 LT |
922 | |
923 | error: | |
38320c70 | 924 | return err; |
1da177e4 LT |
925 | } |
926 | ||
d5860c5c SK |
927 | static int esp6_rcv_cb(struct sk_buff *skb, int err) |
928 | { | |
929 | return 0; | |
930 | } | |
931 | ||
cc24beca | 932 | static const struct xfrm_type esp6_type = { |
1da177e4 | 933 | .description = "ESP6", |
cc24beca IM |
934 | .owner = THIS_MODULE, |
935 | .proto = IPPROTO_ESP, | |
436a0a40 | 936 | .flags = XFRM_TYPE_REPLAY_PROT, |
1da177e4 LT |
937 | .init_state = esp6_init_state, |
938 | .destructor = esp6_destroy, | |
c5c25238 | 939 | .get_mtu = esp6_get_mtu, |
1da177e4 | 940 | .input = esp6_input, |
aee5adb4 MN |
941 | .output = esp6_output, |
942 | .hdr_offset = xfrm6_find_1stfragopt, | |
1da177e4 LT |
943 | }; |
944 | ||
d5860c5c SK |
945 | static struct xfrm6_protocol esp6_protocol = { |
946 | .handler = xfrm6_rcv, | |
947 | .cb_handler = esp6_rcv_cb, | |
1da177e4 | 948 | .err_handler = esp6_err, |
d5860c5c | 949 | .priority = 0, |
1da177e4 LT |
950 | }; |
951 | ||
952 | static int __init esp6_init(void) | |
953 | { | |
954 | if (xfrm_register_type(&esp6_type, AF_INET6) < 0) { | |
f3213831 | 955 | pr_info("%s: can't add xfrm type\n", __func__); |
1da177e4 LT |
956 | return -EAGAIN; |
957 | } | |
d5860c5c | 958 | if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) { |
f3213831 | 959 | pr_info("%s: can't add protocol\n", __func__); |
1da177e4 LT |
960 | xfrm_unregister_type(&esp6_type, AF_INET6); |
961 | return -EAGAIN; | |
962 | } | |
963 | ||
964 | return 0; | |
965 | } | |
966 | ||
967 | static void __exit esp6_fini(void) | |
968 | { | |
d5860c5c | 969 | if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0) |
f3213831 | 970 | pr_info("%s: can't remove protocol\n", __func__); |
1da177e4 | 971 | if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0) |
f3213831 | 972 | pr_info("%s: can't remove xfrm type\n", __func__); |
1da177e4 LT |
973 | } |
974 | ||
975 | module_init(esp6_init); | |
976 | module_exit(esp6_fini); | |
977 | ||
978 | MODULE_LICENSE("GPL"); | |
d3d6dd3a | 979 | MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP); |