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v3.15
 
  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
 
 
 47struct 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
 54static 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 */
 65static 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
 87static inline __be32 *esp_tmp_seqhi(void *tmp)
 88{
 89	return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
 90}
 91
 92static 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
 99static 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
110static 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
120static 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
128static 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
136static 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
144static 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
 
 
263error:
264	return err;
265}
 
266
267static 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
309out:
310	return err;
311}
 
312
313static 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
320static 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
405out:
406	return ret;
407}
408
409static 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
424static int 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 0;
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 0;
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	return 0;
448}
449
450static void esp6_destroy(struct xfrm_state *x)
451{
452	struct crypto_aead *aead = x->data;
453
454	if (!aead)
455		return;
456
457	crypto_free_aead(aead);
458}
459
460static int esp_init_aead(struct xfrm_state *x)
461{
 
462	struct crypto_aead *aead;
463	int err;
464
465	aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
 
 
 
 
 
466	err = PTR_ERR(aead);
467	if (IS_ERR(aead))
468		goto error;
469
470	x->data = aead;
471
472	err = crypto_aead_setkey(aead, x->aead->alg_key,
473				 (x->aead->alg_key_len + 7) / 8);
474	if (err)
475		goto error;
476
477	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
478	if (err)
479		goto error;
480
481error:
482	return err;
483}
484
485static int esp_init_authenc(struct xfrm_state *x)
486{
487	struct crypto_aead *aead;
488	struct crypto_authenc_key_param *param;
489	struct rtattr *rta;
490	char *key;
491	char *p;
492	char authenc_name[CRYPTO_MAX_ALG_NAME];
493	unsigned int keylen;
494	int err;
495
496	err = -EINVAL;
497	if (x->ealg == NULL)
498		goto error;
499
500	err = -ENAMETOOLONG;
501
502	if ((x->props.flags & XFRM_STATE_ESN)) {
503		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
504			     "authencesn(%s,%s)",
 
505			     x->aalg ? x->aalg->alg_name : "digest_null",
506			     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 
507			goto error;
508	} else {
509		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
510			     "authenc(%s,%s)",
 
511			     x->aalg ? x->aalg->alg_name : "digest_null",
512			     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 
513			goto error;
514	}
515
516	aead = crypto_alloc_aead(authenc_name, 0, 0);
517	err = PTR_ERR(aead);
518	if (IS_ERR(aead))
519		goto error;
520
521	x->data = aead;
522
523	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
524		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
525	err = -ENOMEM;
526	key = kmalloc(keylen, GFP_KERNEL);
527	if (!key)
528		goto error;
529
530	p = key;
531	rta = (void *)p;
532	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
533	rta->rta_len = RTA_LENGTH(sizeof(*param));
534	param = RTA_DATA(rta);
535	p += RTA_SPACE(sizeof(*param));
536
537	if (x->aalg) {
538		struct xfrm_algo_desc *aalg_desc;
539
540		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
541		p += (x->aalg->alg_key_len + 7) / 8;
542
543		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
544		BUG_ON(!aalg_desc);
545
546		err = -EINVAL;
547		if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
548		    crypto_aead_authsize(aead)) {
549			NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
550				 x->aalg->alg_name,
551				 crypto_aead_authsize(aead),
552				 aalg_desc->uinfo.auth.icv_fullbits/8);
553			goto free_key;
554		}
555
556		err = crypto_aead_setauthsize(
557			aead, x->aalg->alg_trunc_len / 8);
558		if (err)
559			goto free_key;
560	}
561
562	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
563	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
564
565	err = crypto_aead_setkey(aead, key, keylen);
566
567free_key:
568	kfree(key);
569
570error:
571	return err;
572}
573
574static int esp6_init_state(struct xfrm_state *x)
575{
576	struct crypto_aead *aead;
577	u32 align;
578	int err;
579
580	if (x->encap)
581		return -EINVAL;
582
583	x->data = NULL;
584
585	if (x->aead)
586		err = esp_init_aead(x);
587	else
588		err = esp_init_authenc(x);
589
590	if (err)
591		goto error;
592
593	aead = x->data;
594
595	x->props.header_len = sizeof(struct ip_esp_hdr) +
596			      crypto_aead_ivsize(aead);
597	switch (x->props.mode) {
598	case XFRM_MODE_BEET:
599		if (x->sel.family != AF_INET6)
600			x->props.header_len += IPV4_BEET_PHMAXLEN +
601				               (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
602		break;
 
603	case XFRM_MODE_TRANSPORT:
604		break;
605	case XFRM_MODE_TUNNEL:
606		x->props.header_len += sizeof(struct ipv6hdr);
607		break;
608	default:
609		goto error;
610	}
611
612	align = ALIGN(crypto_aead_blocksize(aead), 4);
613	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
614
615error:
616	return err;
617}
618
619static int esp6_rcv_cb(struct sk_buff *skb, int err)
620{
621	return 0;
622}
623
624static const struct xfrm_type esp6_type =
625{
626	.description	= "ESP6",
627	.owner	     	= THIS_MODULE,
628	.proto	     	= IPPROTO_ESP,
629	.flags		= XFRM_TYPE_REPLAY_PROT,
630	.init_state	= esp6_init_state,
631	.destructor	= esp6_destroy,
632	.get_mtu	= esp6_get_mtu,
633	.input		= esp6_input,
634	.output		= esp6_output,
635	.hdr_offset	= xfrm6_find_1stfragopt,
636};
637
638static struct xfrm6_protocol esp6_protocol = {
639	.handler	=	xfrm6_rcv,
640	.cb_handler	=	esp6_rcv_cb,
641	.err_handler	=	esp6_err,
642	.priority	=	0,
643};
644
645static int __init esp6_init(void)
646{
647	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
648		pr_info("%s: can't add xfrm type\n", __func__);
649		return -EAGAIN;
650	}
651	if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
652		pr_info("%s: can't add protocol\n", __func__);
653		xfrm_unregister_type(&esp6_type, AF_INET6);
654		return -EAGAIN;
655	}
656
657	return 0;
658}
659
660static void __exit esp6_fini(void)
661{
662	if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
663		pr_info("%s: can't remove protocol\n", __func__);
664	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
665		pr_info("%s: can't remove xfrm type\n", __func__);
666}
667
668module_init(esp6_init);
669module_exit(esp6_fini);
670
671MODULE_LICENSE("GPL");
672MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C)2002 USAGI/WIDE Project
  4 *
 
 
 
 
 
 
 
 
 
 
 
 
 
  5 * Authors
  6 *
  7 *	Mitsuru KANDA @USAGI       : IPv6 Support
  8 *	Kazunori MIYAZAWA @USAGI   :
  9 *	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 10 *
 11 *	This file is derived from net/ipv4/esp.c
 12 */
 13
 14#define pr_fmt(fmt) "IPv6: " fmt
 15
 16#include <crypto/aead.h>
 17#include <crypto/authenc.h>
 18#include <linux/err.h>
 19#include <linux/module.h>
 20#include <net/ip.h>
 21#include <net/xfrm.h>
 22#include <net/esp.h>
 23#include <linux/scatterlist.h>
 24#include <linux/kernel.h>
 25#include <linux/pfkeyv2.h>
 26#include <linux/random.h>
 27#include <linux/slab.h>
 28#include <linux/spinlock.h>
 29#include <net/ip6_route.h>
 30#include <net/icmp.h>
 31#include <net/ipv6.h>
 32#include <net/protocol.h>
 33#include <linux/icmpv6.h>
 34
 35#include <linux/highmem.h>
 36
 37struct esp_skb_cb {
 38	struct xfrm_skb_cb xfrm;
 39	void *tmp;
 40};
 41
 42#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
 43
 
 
 44/*
 45 * Allocate an AEAD request structure with extra space for SG and IV.
 46 *
 47 * For alignment considerations the upper 32 bits of the sequence number are
 48 * placed at the front, if present. Followed by the IV, the request and finally
 49 * the SG list.
 50 *
 51 * TODO: Use spare space in skb for this where possible.
 52 */
 53static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
 54{
 55	unsigned int len;
 56
 57	len = seqihlen;
 58
 59	len += crypto_aead_ivsize(aead);
 60
 61	if (len) {
 62		len += crypto_aead_alignmask(aead) &
 63		       ~(crypto_tfm_ctx_alignment() - 1);
 64		len = ALIGN(len, crypto_tfm_ctx_alignment());
 65	}
 66
 67	len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
 68	len = ALIGN(len, __alignof__(struct scatterlist));
 69
 70	len += sizeof(struct scatterlist) * nfrags;
 71
 72	return kmalloc(len, GFP_ATOMIC);
 73}
 74
 75static inline __be32 *esp_tmp_seqhi(void *tmp)
 76{
 77	return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
 78}
 79
 80static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
 81{
 82	return crypto_aead_ivsize(aead) ?
 83	       PTR_ALIGN((u8 *)tmp + seqhilen,
 84			 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
 85}
 86
 
 
 
 
 
 
 
 
 
 
 
 87static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
 88{
 89	struct aead_request *req;
 90
 91	req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
 92				crypto_tfm_ctx_alignment());
 93	aead_request_set_tfm(req, aead);
 94	return req;
 95}
 96
 97static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
 98					     struct aead_request *req)
 99{
100	return (void *)ALIGN((unsigned long)(req + 1) +
101			     crypto_aead_reqsize(aead),
102			     __alignof__(struct scatterlist));
103}
104
105static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
 
106{
107	struct crypto_aead *aead = x->data;
108	int seqhilen = 0;
109	u8 *iv;
110	struct aead_request *req;
111	struct scatterlist *sg;
112
113	if (x->props.flags & XFRM_STATE_ESN)
114		seqhilen += sizeof(__be32);
115
116	iv = esp_tmp_iv(aead, tmp, seqhilen);
117	req = esp_tmp_req(aead, iv);
118
119	/* Unref skb_frag_pages in the src scatterlist if necessary.
120	 * Skip the first sg which comes from skb->data.
121	 */
122	if (req->src != req->dst)
123		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
124			put_page(sg_page(sg));
125}
126
127static void esp_output_done(struct crypto_async_request *base, int err)
128{
129	struct sk_buff *skb = base->data;
130	struct xfrm_offload *xo = xfrm_offload(skb);
131	void *tmp;
132	struct xfrm_state *x;
133
134	if (xo && (xo->flags & XFRM_DEV_RESUME)) {
135		struct sec_path *sp = skb_sec_path(skb);
 
136
137		x = sp->xvec[sp->len - 1];
138	} else {
139		x = skb_dst(skb)->xfrm;
140	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
141
142	tmp = ESP_SKB_CB(skb)->tmp;
143	esp_ssg_unref(x, tmp);
144	kfree(tmp);
145
146	if (xo && (xo->flags & XFRM_DEV_RESUME)) {
147		if (err) {
148			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
149			kfree_skb(skb);
150			return;
151		}
152
153		skb_push(skb, skb->data - skb_mac_header(skb));
154		secpath_reset(skb);
155		xfrm_dev_resume(skb);
156	} else {
157		xfrm_output_resume(skb, err);
158	}
159}
 
 
160
161/* Move ESP header back into place. */
162static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
163{
164	struct ip_esp_hdr *esph = (void *)(skb->data + offset);
165	void *tmp = ESP_SKB_CB(skb)->tmp;
166	__be32 *seqhi = esp_tmp_seqhi(tmp);
167
168	esph->seq_no = esph->spi;
169	esph->spi = *seqhi;
170}
171
172static void esp_output_restore_header(struct sk_buff *skb)
173{
174	esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
175}
 
176
177static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
178					     struct xfrm_state *x,
179					     struct ip_esp_hdr *esph,
180					     __be32 *seqhi)
181{
182	/* For ESN we move the header forward by 4 bytes to
183	 * accomodate the high bits.  We will move it back after
184	 * encryption.
185	 */
186	if ((x->props.flags & XFRM_STATE_ESN)) {
187		struct xfrm_offload *xo = xfrm_offload(skb);
188
189		esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
190		*seqhi = esph->spi;
191		if (xo)
192			esph->seq_no = htonl(xo->seq.hi);
193		else
194			esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
195	}
196
197	esph->spi = x->id.spi;
198
199	return esph;
200}
201
202static void esp_output_done_esn(struct crypto_async_request *base, int err)
203{
204	struct sk_buff *skb = base->data;
205
206	esp_output_restore_header(skb);
207	esp_output_done(base, err);
208}
209
210static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
211{
212	/* Fill padding... */
 
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] = proto;
224}
225
226int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
227{
228	u8 *tail;
229	u8 *vaddr;
230	int nfrags;
231	struct page *page;
232	struct sk_buff *trailer;
233	int tailen = esp->tailen;
234
235	if (!skb_cloned(skb)) {
236		if (tailen <= skb_tailroom(skb)) {
237			nfrags = 1;
238			trailer = skb;
239			tail = skb_tail_pointer(trailer);
240
241			goto skip_cow;
242		} else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
243			   && !skb_has_frag_list(skb)) {
244			int allocsize;
245			struct sock *sk = skb->sk;
246			struct page_frag *pfrag = &x->xfrag;
247
248			esp->inplace = false;
249
250			allocsize = ALIGN(tailen, L1_CACHE_BYTES);
251
252			spin_lock_bh(&x->lock);
253
254			if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
255				spin_unlock_bh(&x->lock);
256				goto cow;
257			}
258
259			page = pfrag->page;
260			get_page(page);
261
262			vaddr = kmap_atomic(page);
263
264			tail = vaddr + pfrag->offset;
265
266			esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
267
268			kunmap_atomic(vaddr);
269
270			nfrags = skb_shinfo(skb)->nr_frags;
271
272			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
273					     tailen);
274			skb_shinfo(skb)->nr_frags = ++nfrags;
275
276			pfrag->offset = pfrag->offset + allocsize;
277
278			spin_unlock_bh(&x->lock);
279
280			nfrags++;
281
282			skb->len += tailen;
283			skb->data_len += tailen;
284			skb->truesize += tailen;
285			if (sk && sk_fullsock(sk))
286				refcount_add(tailen, &sk->sk_wmem_alloc);
287
288			goto out;
289		}
290	}
291
292cow:
293	nfrags = skb_cow_data(skb, tailen, &trailer);
294	if (nfrags < 0)
295		goto out;
296	tail = skb_tail_pointer(trailer);
297
298skip_cow:
299	esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
300	pskb_put(skb, trailer, tailen);
301
302out:
303	return nfrags;
304}
305EXPORT_SYMBOL_GPL(esp6_output_head);
306
307int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
308{
309	u8 *iv;
310	int alen;
311	void *tmp;
312	int ivlen;
313	int assoclen;
314	int seqhilen;
315	__be32 *seqhi;
316	struct page *page;
317	struct ip_esp_hdr *esph;
318	struct aead_request *req;
319	struct crypto_aead *aead;
320	struct scatterlist *sg, *dsg;
321	int err = -ENOMEM;
322
323	assoclen = sizeof(struct ip_esp_hdr);
324	seqhilen = 0;
325
326	if (x->props.flags & XFRM_STATE_ESN) {
327		seqhilen += sizeof(__be32);
328		assoclen += sizeof(__be32);
329	}
330
331	aead = x->data;
332	alen = crypto_aead_authsize(aead);
333	ivlen = crypto_aead_ivsize(aead);
334
335	tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
336	if (!tmp)
337		goto error;
338
339	seqhi = esp_tmp_seqhi(tmp);
340	iv = esp_tmp_iv(aead, tmp, seqhilen);
341	req = esp_tmp_req(aead, iv);
342	sg = esp_req_sg(aead, req);
343
344	if (esp->inplace)
345		dsg = sg;
346	else
347		dsg = &sg[esp->nfrags];
348
349	esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
350
351	sg_init_table(sg, esp->nfrags);
352	err = skb_to_sgvec(skb, sg,
353		           (unsigned char *)esph - skb->data,
354		           assoclen + ivlen + esp->clen + alen);
355	if (unlikely(err < 0))
356		goto error_free;
357
358	if (!esp->inplace) {
359		int allocsize;
360		struct page_frag *pfrag = &x->xfrag;
361
362		allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
363
364		spin_lock_bh(&x->lock);
365		if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
366			spin_unlock_bh(&x->lock);
367			goto error_free;
368		}
369
370		skb_shinfo(skb)->nr_frags = 1;
371
372		page = pfrag->page;
373		get_page(page);
374		/* replace page frags in skb with new page */
375		__skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
376		pfrag->offset = pfrag->offset + allocsize;
377		spin_unlock_bh(&x->lock);
378
379		sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
380		err = skb_to_sgvec(skb, dsg,
381			           (unsigned char *)esph - skb->data,
382			           assoclen + ivlen + esp->clen + alen);
383		if (unlikely(err < 0))
384			goto error_free;
385	}
386
387	if ((x->props.flags & XFRM_STATE_ESN))
388		aead_request_set_callback(req, 0, esp_output_done_esn, skb);
389	else
390		aead_request_set_callback(req, 0, esp_output_done, skb);
391
392	aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
393	aead_request_set_ad(req, assoclen);
394
395	memset(iv, 0, ivlen);
396	memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
397	       min(ivlen, 8));
398
399	ESP_SKB_CB(skb)->tmp = tmp;
400	err = crypto_aead_encrypt(req);
401
402	switch (err) {
403	case -EINPROGRESS:
404		goto error;
405
406	case -ENOSPC:
407		err = NET_XMIT_DROP;
408		break;
409
410	case 0:
411		if ((x->props.flags & XFRM_STATE_ESN))
412			esp_output_restore_header(skb);
413	}
414
415	if (sg != dsg)
416		esp_ssg_unref(x, tmp);
417
418error_free:
419	kfree(tmp);
420error:
421	return err;
422}
423EXPORT_SYMBOL_GPL(esp6_output_tail);
424
425static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
426{
427	int alen;
428	int blksize;
429	struct ip_esp_hdr *esph;
430	struct crypto_aead *aead;
431	struct esp_info esp;
432
433	esp.inplace = true;
434
435	esp.proto = *skb_mac_header(skb);
436	*skb_mac_header(skb) = IPPROTO_ESP;
437
438	/* skb is pure payload to encrypt */
439
440	aead = x->data;
441	alen = crypto_aead_authsize(aead);
442
443	esp.tfclen = 0;
444	if (x->tfcpad) {
445		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
446		u32 padto;
447
448		padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
449		if (skb->len < padto)
450			esp.tfclen = padto - skb->len;
451	}
452	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
453	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
454	esp.plen = esp.clen - skb->len - esp.tfclen;
455	esp.tailen = esp.tfclen + esp.plen + alen;
456
457	esp.nfrags = esp6_output_head(x, skb, &esp);
458	if (esp.nfrags < 0)
459		return esp.nfrags;
460
461	esph = ip_esp_hdr(skb);
462	esph->spi = x->id.spi;
463
464	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
465	esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
466			    ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
467
468	skb_push(skb, -skb_network_offset(skb));
469
470	return esp6_output_tail(x, skb, &esp);
471}
472
473static inline int esp_remove_trailer(struct sk_buff *skb)
474{
475	struct xfrm_state *x = xfrm_input_state(skb);
476	struct xfrm_offload *xo = xfrm_offload(skb);
477	struct crypto_aead *aead = x->data;
478	int alen, hlen, elen;
479	int padlen, trimlen;
480	__wsum csumdiff;
 
 
481	u8 nexthdr[2];
482	int ret;
483
484	alen = crypto_aead_authsize(aead);
485	hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
486	elen = skb->len - hlen;
487
488	if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
489		ret = xo->proto;
490		goto out;
491	}
492
493	ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
494	BUG_ON(ret);
495
496	ret = -EINVAL;
497	padlen = nexthdr[0];
498	if (padlen + 2 + alen >= elen) {
499		net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
500				    padlen + 2, elen - alen);
501		goto out;
502	}
503
504	trimlen = alen + padlen + 2;
505	if (skb->ip_summed == CHECKSUM_COMPLETE) {
506		csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
507		skb->csum = csum_block_sub(skb->csum, csumdiff,
508					   skb->len - trimlen);
509	}
510	pskb_trim(skb, skb->len - trimlen);
511
512	ret = nexthdr[1];
513
514out:
515	return ret;
516}
517
518int esp6_input_done2(struct sk_buff *skb, int err)
519{
520	struct xfrm_state *x = xfrm_input_state(skb);
521	struct xfrm_offload *xo = xfrm_offload(skb);
522	struct crypto_aead *aead = x->data;
523	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
524	int hdr_len = skb_network_header_len(skb);
525
526	if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
527		kfree(ESP_SKB_CB(skb)->tmp);
528
529	if (unlikely(err))
530		goto out;
531
532	err = esp_remove_trailer(skb);
533	if (unlikely(err < 0))
534		goto out;
535
536	skb_postpull_rcsum(skb, skb_network_header(skb),
537			   skb_network_header_len(skb));
538	skb_pull_rcsum(skb, hlen);
539	if (x->props.mode == XFRM_MODE_TUNNEL)
540		skb_reset_transport_header(skb);
541	else
542		skb_set_transport_header(skb, -hdr_len);
543
 
 
544	/* RFC4303: Drop dummy packets without any error */
545	if (err == IPPROTO_NONE)
546		err = -EINVAL;
547
548out:
549	return err;
550}
551EXPORT_SYMBOL_GPL(esp6_input_done2);
552
553static void esp_input_done(struct crypto_async_request *base, int err)
554{
555	struct sk_buff *skb = base->data;
556
557	xfrm_input_resume(skb, esp6_input_done2(skb, err));
558}
559
560static void esp_input_restore_header(struct sk_buff *skb)
561{
562	esp_restore_header(skb, 0);
563	__skb_pull(skb, 4);
564}
565
566static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
567{
568	struct xfrm_state *x = xfrm_input_state(skb);
569
570	/* For ESN we move the header forward by 4 bytes to
571	 * accomodate the high bits.  We will move it back after
572	 * decryption.
573	 */
574	if ((x->props.flags & XFRM_STATE_ESN)) {
575		struct ip_esp_hdr *esph = skb_push(skb, 4);
576
577		*seqhi = esph->spi;
578		esph->spi = esph->seq_no;
579		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
580	}
581}
582
583static void esp_input_done_esn(struct crypto_async_request *base, int err)
584{
585	struct sk_buff *skb = base->data;
586
587	esp_input_restore_header(skb);
588	esp_input_done(base, err);
589}
590
591static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
592{
 
593	struct crypto_aead *aead = x->data;
594	struct aead_request *req;
595	struct sk_buff *trailer;
596	int ivlen = crypto_aead_ivsize(aead);
597	int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
598	int nfrags;
599	int assoclen;
 
600	int seqhilen;
601	int ret = 0;
602	void *tmp;
603	__be32 *seqhi;
604	u8 *iv;
605	struct scatterlist *sg;
 
606
607	if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
608		ret = -EINVAL;
609		goto out;
610	}
611
612	if (elen <= 0) {
613		ret = -EINVAL;
614		goto out;
615	}
616
617	assoclen = sizeof(struct ip_esp_hdr);
 
 
 
 
 
 
 
 
618	seqhilen = 0;
619
620	if (x->props.flags & XFRM_STATE_ESN) {
 
621		seqhilen += sizeof(__be32);
622		assoclen += seqhilen;
623	}
624
625	if (!skb_cloned(skb)) {
626		if (!skb_is_nonlinear(skb)) {
627			nfrags = 1;
628
629			goto skip_cow;
630		} else if (!skb_has_frag_list(skb)) {
631			nfrags = skb_shinfo(skb)->nr_frags;
632			nfrags++;
633
634			goto skip_cow;
635		}
636	}
637
638	nfrags = skb_cow_data(skb, 0, &trailer);
639	if (nfrags < 0) {
640		ret = -EINVAL;
641		goto out;
642	}
643
644skip_cow:
645	ret = -ENOMEM;
646	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
647	if (!tmp)
648		goto out;
649
650	ESP_SKB_CB(skb)->tmp = tmp;
651	seqhi = esp_tmp_seqhi(tmp);
652	iv = esp_tmp_iv(aead, tmp, seqhilen);
653	req = esp_tmp_req(aead, iv);
654	sg = esp_req_sg(aead, req);
 
655
656	esp_input_set_header(skb, seqhi);
657
658	sg_init_table(sg, nfrags);
659	ret = skb_to_sgvec(skb, sg, 0, skb->len);
660	if (unlikely(ret < 0)) {
661		kfree(tmp);
662		goto out;
663	}
664
665	skb->ip_summed = CHECKSUM_NONE;
 
666
667	if ((x->props.flags & XFRM_STATE_ESN))
668		aead_request_set_callback(req, 0, esp_input_done_esn, skb);
669	else
670		aead_request_set_callback(req, 0, esp_input_done, skb);
671
672	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
673	aead_request_set_ad(req, assoclen);
 
 
 
 
 
 
 
 
 
 
674
675	ret = crypto_aead_decrypt(req);
676	if (ret == -EINPROGRESS)
677		goto out;
678
679	if ((x->props.flags & XFRM_STATE_ESN))
680		esp_input_restore_header(skb);
681
682	ret = esp6_input_done2(skb, ret);
683
684out:
685	return ret;
686}
687
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
688static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
689		    u8 type, u8 code, int offset, __be32 info)
690{
691	struct net *net = dev_net(skb->dev);
692	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
693	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
694	struct xfrm_state *x;
695
696	if (type != ICMPV6_PKT_TOOBIG &&
697	    type != NDISC_REDIRECT)
698		return 0;
699
700	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
701			      esph->spi, IPPROTO_ESP, AF_INET6);
702	if (!x)
703		return 0;
704
705	if (type == NDISC_REDIRECT)
706		ip6_redirect(skb, net, skb->dev->ifindex, 0,
707			     sock_net_uid(net, NULL));
708	else
709		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
710	xfrm_state_put(x);
711
712	return 0;
713}
714
715static void esp6_destroy(struct xfrm_state *x)
716{
717	struct crypto_aead *aead = x->data;
718
719	if (!aead)
720		return;
721
722	crypto_free_aead(aead);
723}
724
725static int esp_init_aead(struct xfrm_state *x)
726{
727	char aead_name[CRYPTO_MAX_ALG_NAME];
728	struct crypto_aead *aead;
729	int err;
730
731	err = -ENAMETOOLONG;
732	if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
733		     x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
734		goto error;
735
736	aead = crypto_alloc_aead(aead_name, 0, 0);
737	err = PTR_ERR(aead);
738	if (IS_ERR(aead))
739		goto error;
740
741	x->data = aead;
742
743	err = crypto_aead_setkey(aead, x->aead->alg_key,
744				 (x->aead->alg_key_len + 7) / 8);
745	if (err)
746		goto error;
747
748	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
749	if (err)
750		goto error;
751
752error:
753	return err;
754}
755
756static int esp_init_authenc(struct xfrm_state *x)
757{
758	struct crypto_aead *aead;
759	struct crypto_authenc_key_param *param;
760	struct rtattr *rta;
761	char *key;
762	char *p;
763	char authenc_name[CRYPTO_MAX_ALG_NAME];
764	unsigned int keylen;
765	int err;
766
767	err = -EINVAL;
768	if (!x->ealg)
769		goto error;
770
771	err = -ENAMETOOLONG;
772
773	if ((x->props.flags & XFRM_STATE_ESN)) {
774		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
775			     "%s%sauthencesn(%s,%s)%s",
776			     x->geniv ?: "", x->geniv ? "(" : "",
777			     x->aalg ? x->aalg->alg_name : "digest_null",
778			     x->ealg->alg_name,
779			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
780			goto error;
781	} else {
782		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
783			     "%s%sauthenc(%s,%s)%s",
784			     x->geniv ?: "", x->geniv ? "(" : "",
785			     x->aalg ? x->aalg->alg_name : "digest_null",
786			     x->ealg->alg_name,
787			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
788			goto error;
789	}
790
791	aead = crypto_alloc_aead(authenc_name, 0, 0);
792	err = PTR_ERR(aead);
793	if (IS_ERR(aead))
794		goto error;
795
796	x->data = aead;
797
798	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
799		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
800	err = -ENOMEM;
801	key = kmalloc(keylen, GFP_KERNEL);
802	if (!key)
803		goto error;
804
805	p = key;
806	rta = (void *)p;
807	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
808	rta->rta_len = RTA_LENGTH(sizeof(*param));
809	param = RTA_DATA(rta);
810	p += RTA_SPACE(sizeof(*param));
811
812	if (x->aalg) {
813		struct xfrm_algo_desc *aalg_desc;
814
815		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
816		p += (x->aalg->alg_key_len + 7) / 8;
817
818		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
819		BUG_ON(!aalg_desc);
820
821		err = -EINVAL;
822		if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
823		    crypto_aead_authsize(aead)) {
824			pr_info("ESP: %s digestsize %u != %hu\n",
825				x->aalg->alg_name,
826				crypto_aead_authsize(aead),
827				aalg_desc->uinfo.auth.icv_fullbits / 8);
828			goto free_key;
829		}
830
831		err = crypto_aead_setauthsize(
832			aead, x->aalg->alg_trunc_len / 8);
833		if (err)
834			goto free_key;
835	}
836
837	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
838	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
839
840	err = crypto_aead_setkey(aead, key, keylen);
841
842free_key:
843	kfree(key);
844
845error:
846	return err;
847}
848
849static int esp6_init_state(struct xfrm_state *x)
850{
851	struct crypto_aead *aead;
852	u32 align;
853	int err;
854
855	if (x->encap)
856		return -EINVAL;
857
858	x->data = NULL;
859
860	if (x->aead)
861		err = esp_init_aead(x);
862	else
863		err = esp_init_authenc(x);
864
865	if (err)
866		goto error;
867
868	aead = x->data;
869
870	x->props.header_len = sizeof(struct ip_esp_hdr) +
871			      crypto_aead_ivsize(aead);
872	switch (x->props.mode) {
873	case XFRM_MODE_BEET:
874		if (x->sel.family != AF_INET6)
875			x->props.header_len += IPV4_BEET_PHMAXLEN +
876					       (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
877		break;
878	default:
879	case XFRM_MODE_TRANSPORT:
880		break;
881	case XFRM_MODE_TUNNEL:
882		x->props.header_len += sizeof(struct ipv6hdr);
883		break;
 
 
884	}
885
886	align = ALIGN(crypto_aead_blocksize(aead), 4);
887	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
888
889error:
890	return err;
891}
892
893static int esp6_rcv_cb(struct sk_buff *skb, int err)
894{
895	return 0;
896}
897
898static const struct xfrm_type esp6_type = {
 
899	.description	= "ESP6",
900	.owner		= THIS_MODULE,
901	.proto		= IPPROTO_ESP,
902	.flags		= XFRM_TYPE_REPLAY_PROT,
903	.init_state	= esp6_init_state,
904	.destructor	= esp6_destroy,
 
905	.input		= esp6_input,
906	.output		= esp6_output,
907	.hdr_offset	= xfrm6_find_1stfragopt,
908};
909
910static struct xfrm6_protocol esp6_protocol = {
911	.handler	=	xfrm6_rcv,
912	.cb_handler	=	esp6_rcv_cb,
913	.err_handler	=	esp6_err,
914	.priority	=	0,
915};
916
917static int __init esp6_init(void)
918{
919	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
920		pr_info("%s: can't add xfrm type\n", __func__);
921		return -EAGAIN;
922	}
923	if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
924		pr_info("%s: can't add protocol\n", __func__);
925		xfrm_unregister_type(&esp6_type, AF_INET6);
926		return -EAGAIN;
927	}
928
929	return 0;
930}
931
932static void __exit esp6_fini(void)
933{
934	if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
935		pr_info("%s: can't remove protocol\n", __func__);
936	xfrm_unregister_type(&esp6_type, AF_INET6);
 
937}
938
939module_init(esp6_init);
940module_exit(esp6_fini);
941
942MODULE_LICENSE("GPL");
943MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);