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fix a kmap leak in virtio_console
[linux/fpc-iii.git] / net / ipv6 / esp6.c
blob6eef8a7e35f2c54514e6bbb8871d18ff18ae691e
1 /*
2 * Copyright (C)2002 USAGI/WIDE Project
3 *
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.
8 *
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.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 *
17 * Authors
18 *
19 * Mitsuru KANDA @USAGI : IPv6 Support
20 * Kazunori MIYAZAWA @USAGI :
21 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
22 *
23 * This file is derived from net/ipv4/esp.c
24 */
25
26 #define pr_fmt(fmt) "IPv6: " fmt
27
28 #include <crypto/aead.h>
29 #include <crypto/authenc.h>
30 #include <linux/err.h>
31 #include <linux/module.h>
32 #include <net/ip.h>
33 #include <net/xfrm.h>
34 #include <net/esp.h>
35 #include <linux/scatterlist.h>
36 #include <linux/kernel.h>
37 #include <linux/pfkeyv2.h>
38 #include <linux/random.h>
39 #include <linux/slab.h>
40 #include <linux/spinlock.h>
41 #include <net/ip6_route.h>
42 #include <net/icmp.h>
43 #include <net/ipv6.h>
44 #include <net/protocol.h>
45 #include <linux/icmpv6.h>
46
47 struct esp_skb_cb {
48 struct xfrm_skb_cb xfrm;
49 void *tmp;
50 };
51
52 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
53
54 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
55
56 /*
57 * Allocate an AEAD request structure with extra space for SG and IV.
58 *
59 * For alignment considerations the upper 32 bits of the sequence number are
60 * placed at the front, if present. Followed by the IV, the request and finally
61 * the SG list.
62 *
63 * TODO: Use spare space in skb for this where possible.
64 */
65 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
66 {
67 unsigned int len;
68
69 len = seqihlen;
70
71 len += crypto_aead_ivsize(aead);
72
73 if (len) {
74 len += crypto_aead_alignmask(aead) &
75 ~(crypto_tfm_ctx_alignment() - 1);
76 len = ALIGN(len, crypto_tfm_ctx_alignment());
77 }
78
79 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
80 len = ALIGN(len, __alignof__(struct scatterlist));
81
82 len += sizeof(struct scatterlist) * nfrags;
83
84 return kmalloc(len, GFP_ATOMIC);
85 }
86
87 static inline __be32 *esp_tmp_seqhi(void *tmp)
88 {
89 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
90 }
91
92 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
93 {
94 return crypto_aead_ivsize(aead) ?
95 PTR_ALIGN((u8 *)tmp + seqhilen,
96 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
97 }
98
99 static inline struct aead_givcrypt_request *esp_tmp_givreq(
100 struct crypto_aead *aead, u8 *iv)
101 {
102 struct aead_givcrypt_request *req;
103
104 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
105 crypto_tfm_ctx_alignment());
106 aead_givcrypt_set_tfm(req, aead);
107 return req;
108 }
109
110 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
111 {
112 struct aead_request *req;
113
114 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
115 crypto_tfm_ctx_alignment());
116 aead_request_set_tfm(req, aead);
117 return req;
118 }
119
120 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
121 struct aead_request *req)
122 {
123 return (void *)ALIGN((unsigned long)(req + 1) +
124 crypto_aead_reqsize(aead),
125 __alignof__(struct scatterlist));
126 }
127
128 static inline struct scatterlist *esp_givreq_sg(
129 struct crypto_aead *aead, struct aead_givcrypt_request *req)
130 {
131 return (void *)ALIGN((unsigned long)(req + 1) +
132 crypto_aead_reqsize(aead),
133 __alignof__(struct scatterlist));
134 }
135
136 static void esp_output_done(struct crypto_async_request *base, int err)
137 {
138 struct sk_buff *skb = base->data;
139
140 kfree(ESP_SKB_CB(skb)->tmp);
141 xfrm_output_resume(skb, err);
142 }
143
144 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
145 {
146 int err;
147 struct ip_esp_hdr *esph;
148 struct crypto_aead *aead;
149 struct aead_givcrypt_request *req;
150 struct scatterlist *sg;
151 struct scatterlist *asg;
152 struct sk_buff *trailer;
153 void *tmp;
154 int blksize;
155 int clen;
156 int alen;
157 int plen;
158 int tfclen;
159 int nfrags;
160 int assoclen;
161 int sglists;
162 int seqhilen;
163 u8 *iv;
164 u8 *tail;
165 __be32 *seqhi;
166
167 /* skb is pure payload to encrypt */
168 aead = x->data;
169 alen = crypto_aead_authsize(aead);
170
171 tfclen = 0;
172 if (x->tfcpad) {
173 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
174 u32 padto;
175
176 padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
177 if (skb->len < padto)
178 tfclen = padto - skb->len;
179 }
180 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
181 clen = ALIGN(skb->len + 2 + tfclen, blksize);
182 plen = clen - skb->len - tfclen;
183
184 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
185 if (err < 0)
186 goto error;
187 nfrags = err;
188
189 assoclen = sizeof(*esph);
190 sglists = 1;
191 seqhilen = 0;
192
193 if (x->props.flags & XFRM_STATE_ESN) {
194 sglists += 2;
195 seqhilen += sizeof(__be32);
196 assoclen += seqhilen;
197 }
198
199 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
200 if (!tmp) {
201 err = -ENOMEM;
202 goto error;
203 }
204
205 seqhi = esp_tmp_seqhi(tmp);
206 iv = esp_tmp_iv(aead, tmp, seqhilen);
207 req = esp_tmp_givreq(aead, iv);
208 asg = esp_givreq_sg(aead, req);
209 sg = asg + sglists;
210
211 /* Fill padding... */
212 tail = skb_tail_pointer(trailer);
213 if (tfclen) {
214 memset(tail, 0, tfclen);
215 tail += tfclen;
216 }
217 do {
218 int i;
219 for (i = 0; i < plen - 2; i++)
220 tail[i] = i + 1;
221 } while (0);
222 tail[plen - 2] = plen - 2;
223 tail[plen - 1] = *skb_mac_header(skb);
224 pskb_put(skb, trailer, clen - skb->len + alen);
225
226 skb_push(skb, -skb_network_offset(skb));
227 esph = ip_esp_hdr(skb);
228 *skb_mac_header(skb) = IPPROTO_ESP;
229
230 esph->spi = x->id.spi;
231 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
232
233 sg_init_table(sg, nfrags);
234 skb_to_sgvec(skb, sg,
235 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
236 clen + alen);
237
238 if ((x->props.flags & XFRM_STATE_ESN)) {
239 sg_init_table(asg, 3);
240 sg_set_buf(asg, &esph->spi, sizeof(__be32));
241 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
242 sg_set_buf(asg + 1, seqhi, seqhilen);
243 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
244 } else
245 sg_init_one(asg, esph, sizeof(*esph));
246
247 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
248 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
249 aead_givcrypt_set_assoc(req, asg, assoclen);
250 aead_givcrypt_set_giv(req, esph->enc_data,
251 XFRM_SKB_CB(skb)->seq.output.low);
252
253 ESP_SKB_CB(skb)->tmp = tmp;
254 err = crypto_aead_givencrypt(req);
255 if (err == -EINPROGRESS)
256 goto error;
257
258 if (err == -EBUSY)
259 err = NET_XMIT_DROP;
260
261 kfree(tmp);
262
263 error:
264 return err;
265 }
266
267 static int esp_input_done2(struct sk_buff *skb, int err)
268 {
269 struct xfrm_state *x = xfrm_input_state(skb);
270 struct crypto_aead *aead = x->data;
271 int alen = crypto_aead_authsize(aead);
272 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
273 int elen = skb->len - hlen;
274 int hdr_len = skb_network_header_len(skb);
275 int padlen;
276 u8 nexthdr[2];
277
278 kfree(ESP_SKB_CB(skb)->tmp);
279
280 if (unlikely(err))
281 goto out;
282
283 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
284 BUG();
285
286 err = -EINVAL;
287 padlen = nexthdr[0];
288 if (padlen + 2 + alen >= elen) {
289 LIMIT_NETDEBUG(KERN_WARNING "ipsec esp packet is garbage "
290 "padlen=%d, elen=%d\n", padlen + 2, elen - alen);
291 goto out;
292 }
293
294 /* ... check padding bits here. Silly. :-) */
295
296 pskb_trim(skb, skb->len - alen - padlen - 2);
297 __skb_pull(skb, hlen);
298 if (x->props.mode == XFRM_MODE_TUNNEL)
299 skb_reset_transport_header(skb);
300 else
301 skb_set_transport_header(skb, -hdr_len);
302
303 err = nexthdr[1];
304
305 /* RFC4303: Drop dummy packets without any error */
306 if (err == IPPROTO_NONE)
307 err = -EINVAL;
308
309 out:
310 return err;
311 }
312
313 static void esp_input_done(struct crypto_async_request *base, int err)
314 {
315 struct sk_buff *skb = base->data;
316
317 xfrm_input_resume(skb, esp_input_done2(skb, err));
318 }
319
320 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
321 {
322 struct ip_esp_hdr *esph;
323 struct crypto_aead *aead = x->data;
324 struct aead_request *req;
325 struct sk_buff *trailer;
326 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
327 int nfrags;
328 int assoclen;
329 int sglists;
330 int seqhilen;
331 int ret = 0;
332 void *tmp;
333 __be32 *seqhi;
334 u8 *iv;
335 struct scatterlist *sg;
336 struct scatterlist *asg;
337
338 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) {
339 ret = -EINVAL;
340 goto out;
341 }
342
343 if (elen <= 0) {
344 ret = -EINVAL;
345 goto out;
346 }
347
348 if ((nfrags = skb_cow_data(skb, 0, &trailer)) < 0) {
349 ret = -EINVAL;
350 goto out;
351 }
352
353 ret = -ENOMEM;
354
355 assoclen = sizeof(*esph);
356 sglists = 1;
357 seqhilen = 0;
358
359 if (x->props.flags & XFRM_STATE_ESN) {
360 sglists += 2;
361 seqhilen += sizeof(__be32);
362 assoclen += seqhilen;
363 }
364
365 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
366 if (!tmp)
367 goto out;
368
369 ESP_SKB_CB(skb)->tmp = tmp;
370 seqhi = esp_tmp_seqhi(tmp);
371 iv = esp_tmp_iv(aead, tmp, seqhilen);
372 req = esp_tmp_req(aead, iv);
373 asg = esp_req_sg(aead, req);
374 sg = asg + sglists;
375
376 skb->ip_summed = CHECKSUM_NONE;
377
378 esph = (struct ip_esp_hdr *)skb->data;
379
380 /* Get ivec. This can be wrong, check against another impls. */
381 iv = esph->enc_data;
382
383 sg_init_table(sg, nfrags);
384 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
385
386 if ((x->props.flags & XFRM_STATE_ESN)) {
387 sg_init_table(asg, 3);
388 sg_set_buf(asg, &esph->spi, sizeof(__be32));
389 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
390 sg_set_buf(asg + 1, seqhi, seqhilen);
391 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
392 } else
393 sg_init_one(asg, esph, sizeof(*esph));
394
395 aead_request_set_callback(req, 0, esp_input_done, skb);
396 aead_request_set_crypt(req, sg, sg, elen, iv);
397 aead_request_set_assoc(req, asg, assoclen);
398
399 ret = crypto_aead_decrypt(req);
400 if (ret == -EINPROGRESS)
401 goto out;
402
403 ret = esp_input_done2(skb, ret);
404
405 out:
406 return ret;
407 }
408
409 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
410 {
411 struct crypto_aead *aead = x->data;
412 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
413 unsigned int net_adj;
414
415 if (x->props.mode != XFRM_MODE_TUNNEL)
416 net_adj = sizeof(struct ipv6hdr);
417 else
418 net_adj = 0;
419
420 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
421 net_adj) & ~(blksize - 1)) + net_adj - 2;
422 }
423
424 static void esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
425 u8 type, u8 code, int offset, __be32 info)
426 {
427 struct net *net = dev_net(skb->dev);
428 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
429 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
430 struct xfrm_state *x;
431
432 if (type != ICMPV6_PKT_TOOBIG &&
433 type != NDISC_REDIRECT)
434 return;
435
436 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
437 esph->spi, IPPROTO_ESP, AF_INET6);
438 if (!x)
439 return;
440
441 if (type == NDISC_REDIRECT)
442 ip6_redirect(skb, net, skb->dev->ifindex, 0);
443 else
444 ip6_update_pmtu(skb, net, info, 0, 0);
445 xfrm_state_put(x);
446 }
447
448 static void esp6_destroy(struct xfrm_state *x)
449 {
450 struct crypto_aead *aead = x->data;
451
452 if (!aead)
453 return;
454
455 crypto_free_aead(aead);
456 }
457
458 static int esp_init_aead(struct xfrm_state *x)
459 {
460 struct crypto_aead *aead;
461 int err;
462
463 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
464 err = PTR_ERR(aead);
465 if (IS_ERR(aead))
466 goto error;
467
468 x->data = aead;
469
470 err = crypto_aead_setkey(aead, x->aead->alg_key,
471 (x->aead->alg_key_len + 7) / 8);
472 if (err)
473 goto error;
474
475 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
476 if (err)
477 goto error;
478
479 error:
480 return err;
481 }
482
483 static int esp_init_authenc(struct xfrm_state *x)
484 {
485 struct crypto_aead *aead;
486 struct crypto_authenc_key_param *param;
487 struct rtattr *rta;
488 char *key;
489 char *p;
490 char authenc_name[CRYPTO_MAX_ALG_NAME];
491 unsigned int keylen;
492 int err;
493
494 err = -EINVAL;
495 if (x->ealg == NULL)
496 goto error;
497
498 err = -ENAMETOOLONG;
499
500 if ((x->props.flags & XFRM_STATE_ESN)) {
501 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
502 "authencesn(%s,%s)",
503 x->aalg ? x->aalg->alg_name : "digest_null",
504 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
505 goto error;
506 } else {
507 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
508 "authenc(%s,%s)",
509 x->aalg ? x->aalg->alg_name : "digest_null",
510 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
511 goto error;
512 }
513
514 aead = crypto_alloc_aead(authenc_name, 0, 0);
515 err = PTR_ERR(aead);
516 if (IS_ERR(aead))
517 goto error;
518
519 x->data = aead;
520
521 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
522 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
523 err = -ENOMEM;
524 key = kmalloc(keylen, GFP_KERNEL);
525 if (!key)
526 goto error;
527
528 p = key;
529 rta = (void *)p;
530 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
531 rta->rta_len = RTA_LENGTH(sizeof(*param));
532 param = RTA_DATA(rta);
533 p += RTA_SPACE(sizeof(*param));
534
535 if (x->aalg) {
536 struct xfrm_algo_desc *aalg_desc;
537
538 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
539 p += (x->aalg->alg_key_len + 7) / 8;
540
541 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
542 BUG_ON(!aalg_desc);
543
544 err = -EINVAL;
545 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
546 crypto_aead_authsize(aead)) {
547 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
548 x->aalg->alg_name,
549 crypto_aead_authsize(aead),
550 aalg_desc->uinfo.auth.icv_fullbits/8);
551 goto free_key;
552 }
553
554 err = crypto_aead_setauthsize(
555 aead, x->aalg->alg_trunc_len / 8);
556 if (err)
557 goto free_key;
558 }
559
560 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
561 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
562
563 err = crypto_aead_setkey(aead, key, keylen);
564
565 free_key:
566 kfree(key);
567
568 error:
569 return err;
570 }
571
572 static int esp6_init_state(struct xfrm_state *x)
573 {
574 struct crypto_aead *aead;
575 u32 align;
576 int err;
577
578 if (x->encap)
579 return -EINVAL;
580
581 x->data = NULL;
582
583 if (x->aead)
584 err = esp_init_aead(x);
585 else
586 err = esp_init_authenc(x);
587
588 if (err)
589 goto error;
590
591 aead = x->data;
592
593 x->props.header_len = sizeof(struct ip_esp_hdr) +
594 crypto_aead_ivsize(aead);
595 switch (x->props.mode) {
596 case XFRM_MODE_BEET:
597 if (x->sel.family != AF_INET6)
598 x->props.header_len += IPV4_BEET_PHMAXLEN +
599 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
600 break;
601 case XFRM_MODE_TRANSPORT:
602 break;
603 case XFRM_MODE_TUNNEL:
604 x->props.header_len += sizeof(struct ipv6hdr);
605 break;
606 default:
607 goto error;
608 }
609
610 align = ALIGN(crypto_aead_blocksize(aead), 4);
611 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
612
613 error:
614 return err;
615 }
616
617 static const struct xfrm_type esp6_type =
618 {
619 .description = "ESP6",
620 .owner = THIS_MODULE,
621 .proto = IPPROTO_ESP,
622 .flags = XFRM_TYPE_REPLAY_PROT,
623 .init_state = esp6_init_state,
624 .destructor = esp6_destroy,
625 .get_mtu = esp6_get_mtu,
626 .input = esp6_input,
627 .output = esp6_output,
628 .hdr_offset = xfrm6_find_1stfragopt,
629 };
630
631 static const struct inet6_protocol esp6_protocol = {
632 .handler = xfrm6_rcv,
633 .err_handler = esp6_err,
634 .flags = INET6_PROTO_NOPOLICY,
635 };
636
637 static int __init esp6_init(void)
638 {
639 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
640 pr_info("%s: can't add xfrm type\n", __func__);
641 return -EAGAIN;
642 }
643 if (inet6_add_protocol(&esp6_protocol, IPPROTO_ESP) < 0) {
644 pr_info("%s: can't add protocol\n", __func__);
645 xfrm_unregister_type(&esp6_type, AF_INET6);
646 return -EAGAIN;
647 }
648
649 return 0;
650 }
651
652 static void __exit esp6_fini(void)
653 {
654 if (inet6_del_protocol(&esp6_protocol, IPPROTO_ESP) < 0)
655 pr_info("%s: can't remove protocol\n", __func__);
656 if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
657 pr_info("%s: can't remove xfrm type\n", __func__);
658 }
659
660 module_init(esp6_init);
661 module_exit(esp6_fini);
662
663 MODULE_LICENSE("GPL");
664 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
Linux with added FPC-III support