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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  */
esp_alloc_tmp(struct crypto_aead * aead,int nfrags,int seqihlen)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_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 
esp_tmp_seqhi(void * tmp)87 static inline __be32 *esp_tmp_seqhi(void *tmp)
88 {
89 	return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
90 }
91 
esp_tmp_iv(struct crypto_aead * aead,void * tmp,int seqhilen)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 
esp_tmp_req(struct crypto_aead * aead,u8 * iv)99 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
100 {
101 	struct aead_request *req;
102 
103 	req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
104 				crypto_tfm_ctx_alignment());
105 	aead_request_set_tfm(req, aead);
106 	return req;
107 }
108 
esp_req_sg(struct crypto_aead * aead,struct aead_request * req)109 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
110 					     struct aead_request *req)
111 {
112 	return (void *)ALIGN((unsigned long)(req + 1) +
113 			     crypto_aead_reqsize(aead),
114 			     __alignof__(struct scatterlist));
115 }
116 
esp_output_done(struct crypto_async_request * base,int err)117 static void esp_output_done(struct crypto_async_request *base, int err)
118 {
119 	struct sk_buff *skb = base->data;
120 
121 	kfree(ESP_SKB_CB(skb)->tmp);
122 	xfrm_output_resume(skb, err);
123 }
124 
125 /* Move ESP header back into place. */
esp_restore_header(struct sk_buff * skb,unsigned int offset)126 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
127 {
128 	struct ip_esp_hdr *esph = (void *)(skb->data + offset);
129 	void *tmp = ESP_SKB_CB(skb)->tmp;
130 	__be32 *seqhi = esp_tmp_seqhi(tmp);
131 
132 	esph->seq_no = esph->spi;
133 	esph->spi = *seqhi;
134 }
135 
esp_output_restore_header(struct sk_buff * skb)136 static void esp_output_restore_header(struct sk_buff *skb)
137 {
138 	esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
139 }
140 
esp_output_done_esn(struct crypto_async_request * base,int err)141 static void esp_output_done_esn(struct crypto_async_request *base, int err)
142 {
143 	struct sk_buff *skb = base->data;
144 
145 	esp_output_restore_header(skb);
146 	esp_output_done(base, err);
147 }
148 
esp6_output(struct xfrm_state * x,struct sk_buff * skb)149 static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
150 {
151 	int err;
152 	struct ip_esp_hdr *esph;
153 	struct crypto_aead *aead;
154 	struct aead_request *req;
155 	struct scatterlist *sg;
156 	struct sk_buff *trailer;
157 	void *tmp;
158 	int blksize;
159 	int clen;
160 	int alen;
161 	int plen;
162 	int ivlen;
163 	int tfclen;
164 	int nfrags;
165 	int assoclen;
166 	int seqhilen;
167 	u8 *iv;
168 	u8 *tail;
169 	__be32 *seqhi;
170 	__be64 seqno;
171 
172 	/* skb is pure payload to encrypt */
173 	aead = x->data;
174 	alen = crypto_aead_authsize(aead);
175 	ivlen = crypto_aead_ivsize(aead);
176 
177 	tfclen = 0;
178 	if (x->tfcpad) {
179 		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
180 		u32 padto;
181 
182 		padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
183 		if (skb->len < padto)
184 			tfclen = padto - skb->len;
185 	}
186 	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
187 	clen = ALIGN(skb->len + 2 + tfclen, blksize);
188 	plen = clen - skb->len - tfclen;
189 
190 	err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
191 	if (err < 0)
192 		goto error;
193 	nfrags = err;
194 
195 	assoclen = sizeof(*esph);
196 	seqhilen = 0;
197 
198 	if (x->props.flags & XFRM_STATE_ESN) {
199 		seqhilen += sizeof(__be32);
200 		assoclen += seqhilen;
201 	}
202 
203 	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
204 	if (!tmp) {
205 		err = -ENOMEM;
206 		goto error;
207 	}
208 
209 	seqhi = esp_tmp_seqhi(tmp);
210 	iv = esp_tmp_iv(aead, tmp, seqhilen);
211 	req = esp_tmp_req(aead, iv);
212 	sg = esp_req_sg(aead, req);
213 
214 	/* Fill padding... */
215 	tail = skb_tail_pointer(trailer);
216 	if (tfclen) {
217 		memset(tail, 0, tfclen);
218 		tail += tfclen;
219 	}
220 	do {
221 		int i;
222 		for (i = 0; i < plen - 2; i++)
223 			tail[i] = i + 1;
224 	} while (0);
225 	tail[plen - 2] = plen - 2;
226 	tail[plen - 1] = *skb_mac_header(skb);
227 	pskb_put(skb, trailer, clen - skb->len + alen);
228 
229 	skb_push(skb, -skb_network_offset(skb));
230 	esph = ip_esp_hdr(skb);
231 	*skb_mac_header(skb) = IPPROTO_ESP;
232 
233 	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
234 
235 	aead_request_set_callback(req, 0, esp_output_done, skb);
236 
237 	/* For ESN we move the header forward by 4 bytes to
238 	 * accomodate the high bits.  We will move it back after
239 	 * encryption.
240 	 */
241 	if ((x->props.flags & XFRM_STATE_ESN)) {
242 		esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
243 		*seqhi = esph->spi;
244 		esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
245 		aead_request_set_callback(req, 0, esp_output_done_esn, skb);
246 	}
247 
248 	esph->spi = x->id.spi;
249 
250 	sg_init_table(sg, nfrags);
251 	err = skb_to_sgvec(skb, sg,
252 		           (unsigned char *)esph - skb->data,
253 		           assoclen + ivlen + clen + alen);
254 	if (unlikely(err < 0))
255 		goto error;
256 
257 	aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
258 	aead_request_set_ad(req, assoclen);
259 
260 	seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
261 			    ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
262 
263 	memset(iv, 0, ivlen);
264 	memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
265 	       min(ivlen, 8));
266 
267 	ESP_SKB_CB(skb)->tmp = tmp;
268 	err = crypto_aead_encrypt(req);
269 
270 	switch (err) {
271 	case -EINPROGRESS:
272 		goto error;
273 
274 	case -EBUSY:
275 		err = NET_XMIT_DROP;
276 		break;
277 
278 	case 0:
279 		if ((x->props.flags & XFRM_STATE_ESN))
280 			esp_output_restore_header(skb);
281 	}
282 
283 	kfree(tmp);
284 
285 error:
286 	return err;
287 }
288 
esp_input_done2(struct sk_buff * skb,int err)289 static int esp_input_done2(struct sk_buff *skb, int err)
290 {
291 	struct xfrm_state *x = xfrm_input_state(skb);
292 	struct crypto_aead *aead = x->data;
293 	int alen = crypto_aead_authsize(aead);
294 	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
295 	int elen = skb->len - hlen;
296 	int hdr_len = skb_network_header_len(skb);
297 	int padlen;
298 	u8 nexthdr[2];
299 
300 	kfree(ESP_SKB_CB(skb)->tmp);
301 
302 	if (unlikely(err))
303 		goto out;
304 
305 	if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
306 		BUG();
307 
308 	err = -EINVAL;
309 	padlen = nexthdr[0];
310 	if (padlen + 2 + alen >= elen) {
311 		net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
312 				    padlen + 2, elen - alen);
313 		goto out;
314 	}
315 
316 	/* ... check padding bits here. Silly. :-) */
317 
318 	pskb_trim(skb, skb->len - alen - padlen - 2);
319 	__skb_pull(skb, hlen);
320 	if (x->props.mode == XFRM_MODE_TUNNEL)
321 		skb_reset_transport_header(skb);
322 	else
323 		skb_set_transport_header(skb, -hdr_len);
324 
325 	err = nexthdr[1];
326 
327 	/* RFC4303: Drop dummy packets without any error */
328 	if (err == IPPROTO_NONE)
329 		err = -EINVAL;
330 
331 out:
332 	return err;
333 }
334 
esp_input_done(struct crypto_async_request * base,int err)335 static void esp_input_done(struct crypto_async_request *base, int err)
336 {
337 	struct sk_buff *skb = base->data;
338 
339 	xfrm_input_resume(skb, esp_input_done2(skb, err));
340 }
341 
esp_input_restore_header(struct sk_buff * skb)342 static void esp_input_restore_header(struct sk_buff *skb)
343 {
344 	esp_restore_header(skb, 0);
345 	__skb_pull(skb, 4);
346 }
347 
esp_input_done_esn(struct crypto_async_request * base,int err)348 static void esp_input_done_esn(struct crypto_async_request *base, int err)
349 {
350 	struct sk_buff *skb = base->data;
351 
352 	esp_input_restore_header(skb);
353 	esp_input_done(base, err);
354 }
355 
esp6_input(struct xfrm_state * x,struct sk_buff * skb)356 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
357 {
358 	struct ip_esp_hdr *esph;
359 	struct crypto_aead *aead = x->data;
360 	struct aead_request *req;
361 	struct sk_buff *trailer;
362 	int ivlen = crypto_aead_ivsize(aead);
363 	int elen = skb->len - sizeof(*esph) - ivlen;
364 	int nfrags;
365 	int assoclen;
366 	int seqhilen;
367 	int ret = 0;
368 	void *tmp;
369 	__be32 *seqhi;
370 	u8 *iv;
371 	struct scatterlist *sg;
372 
373 	if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
374 		ret = -EINVAL;
375 		goto out;
376 	}
377 
378 	if (elen <= 0) {
379 		ret = -EINVAL;
380 		goto out;
381 	}
382 
383 	nfrags = skb_cow_data(skb, 0, &trailer);
384 	if (nfrags < 0) {
385 		ret = -EINVAL;
386 		goto out;
387 	}
388 
389 	ret = -ENOMEM;
390 
391 	assoclen = sizeof(*esph);
392 	seqhilen = 0;
393 
394 	if (x->props.flags & XFRM_STATE_ESN) {
395 		seqhilen += sizeof(__be32);
396 		assoclen += seqhilen;
397 	}
398 
399 	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
400 	if (!tmp)
401 		goto out;
402 
403 	ESP_SKB_CB(skb)->tmp = tmp;
404 	seqhi = esp_tmp_seqhi(tmp);
405 	iv = esp_tmp_iv(aead, tmp, seqhilen);
406 	req = esp_tmp_req(aead, iv);
407 	sg = esp_req_sg(aead, req);
408 
409 	skb->ip_summed = CHECKSUM_NONE;
410 
411 	esph = (struct ip_esp_hdr *)skb->data;
412 
413 	aead_request_set_callback(req, 0, esp_input_done, skb);
414 
415 	/* For ESN we move the header forward by 4 bytes to
416 	 * accomodate the high bits.  We will move it back after
417 	 * decryption.
418 	 */
419 	if ((x->props.flags & XFRM_STATE_ESN)) {
420 		esph = (void *)skb_push(skb, 4);
421 		*seqhi = esph->spi;
422 		esph->spi = esph->seq_no;
423 		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
424 		aead_request_set_callback(req, 0, esp_input_done_esn, skb);
425 	}
426 
427 	sg_init_table(sg, nfrags);
428 	ret = skb_to_sgvec(skb, sg, 0, skb->len);
429 	if (unlikely(ret < 0))
430 		goto out;
431 
432 	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
433 	aead_request_set_ad(req, assoclen);
434 
435 	ret = crypto_aead_decrypt(req);
436 	if (ret == -EINPROGRESS)
437 		goto out;
438 
439 	if ((x->props.flags & XFRM_STATE_ESN))
440 		esp_input_restore_header(skb);
441 
442 	ret = esp_input_done2(skb, ret);
443 
444 out:
445 	return ret;
446 }
447 
esp6_get_mtu(struct xfrm_state * x,int mtu)448 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
449 {
450 	struct crypto_aead *aead = x->data;
451 	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
452 	unsigned int net_adj;
453 
454 	if (x->props.mode != XFRM_MODE_TUNNEL)
455 		net_adj = sizeof(struct ipv6hdr);
456 	else
457 		net_adj = 0;
458 
459 	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
460 		 net_adj) & ~(blksize - 1)) + net_adj - 2;
461 }
462 
esp6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)463 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
464 		    u8 type, u8 code, int offset, __be32 info)
465 {
466 	struct net *net = dev_net(skb->dev);
467 	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
468 	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
469 	struct xfrm_state *x;
470 
471 	if (type != ICMPV6_PKT_TOOBIG &&
472 	    type != NDISC_REDIRECT)
473 		return 0;
474 
475 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
476 			      esph->spi, IPPROTO_ESP, AF_INET6);
477 	if (!x)
478 		return 0;
479 
480 	if (type == NDISC_REDIRECT)
481 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
482 			     sock_net_uid(net, NULL));
483 	else
484 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
485 	xfrm_state_put(x);
486 
487 	return 0;
488 }
489 
esp6_destroy(struct xfrm_state * x)490 static void esp6_destroy(struct xfrm_state *x)
491 {
492 	struct crypto_aead *aead = x->data;
493 
494 	if (!aead)
495 		return;
496 
497 	crypto_free_aead(aead);
498 }
499 
esp_init_aead(struct xfrm_state * x)500 static int esp_init_aead(struct xfrm_state *x)
501 {
502 	char aead_name[CRYPTO_MAX_ALG_NAME];
503 	struct crypto_aead *aead;
504 	int err;
505 
506 	err = -ENAMETOOLONG;
507 	if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
508 		     x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
509 		goto error;
510 
511 	aead = crypto_alloc_aead(aead_name, 0, 0);
512 	err = PTR_ERR(aead);
513 	if (IS_ERR(aead))
514 		goto error;
515 
516 	x->data = aead;
517 
518 	err = crypto_aead_setkey(aead, x->aead->alg_key,
519 				 (x->aead->alg_key_len + 7) / 8);
520 	if (err)
521 		goto error;
522 
523 	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
524 	if (err)
525 		goto error;
526 
527 error:
528 	return err;
529 }
530 
esp_init_authenc(struct xfrm_state * x)531 static int esp_init_authenc(struct xfrm_state *x)
532 {
533 	struct crypto_aead *aead;
534 	struct crypto_authenc_key_param *param;
535 	struct rtattr *rta;
536 	char *key;
537 	char *p;
538 	char authenc_name[CRYPTO_MAX_ALG_NAME];
539 	unsigned int keylen;
540 	int err;
541 
542 	err = -EINVAL;
543 	if (!x->ealg)
544 		goto error;
545 
546 	err = -ENAMETOOLONG;
547 
548 	if ((x->props.flags & XFRM_STATE_ESN)) {
549 		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
550 			     "%s%sauthencesn(%s,%s)%s",
551 			     x->geniv ?: "", x->geniv ? "(" : "",
552 			     x->aalg ? x->aalg->alg_name : "digest_null",
553 			     x->ealg->alg_name,
554 			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
555 			goto error;
556 	} else {
557 		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
558 			     "%s%sauthenc(%s,%s)%s",
559 			     x->geniv ?: "", x->geniv ? "(" : "",
560 			     x->aalg ? x->aalg->alg_name : "digest_null",
561 			     x->ealg->alg_name,
562 			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
563 			goto error;
564 	}
565 
566 	aead = crypto_alloc_aead(authenc_name, 0, 0);
567 	err = PTR_ERR(aead);
568 	if (IS_ERR(aead))
569 		goto error;
570 
571 	x->data = aead;
572 
573 	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
574 		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
575 	err = -ENOMEM;
576 	key = kmalloc(keylen, GFP_KERNEL);
577 	if (!key)
578 		goto error;
579 
580 	p = key;
581 	rta = (void *)p;
582 	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
583 	rta->rta_len = RTA_LENGTH(sizeof(*param));
584 	param = RTA_DATA(rta);
585 	p += RTA_SPACE(sizeof(*param));
586 
587 	if (x->aalg) {
588 		struct xfrm_algo_desc *aalg_desc;
589 
590 		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
591 		p += (x->aalg->alg_key_len + 7) / 8;
592 
593 		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
594 		BUG_ON(!aalg_desc);
595 
596 		err = -EINVAL;
597 		if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
598 		    crypto_aead_authsize(aead)) {
599 			pr_info("ESP: %s digestsize %u != %hu\n",
600 				x->aalg->alg_name,
601 				crypto_aead_authsize(aead),
602 				aalg_desc->uinfo.auth.icv_fullbits / 8);
603 			goto free_key;
604 		}
605 
606 		err = crypto_aead_setauthsize(
607 			aead, x->aalg->alg_trunc_len / 8);
608 		if (err)
609 			goto free_key;
610 	}
611 
612 	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
613 	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
614 
615 	err = crypto_aead_setkey(aead, key, keylen);
616 
617 free_key:
618 	kfree(key);
619 
620 error:
621 	return err;
622 }
623 
esp6_init_state(struct xfrm_state * x)624 static int esp6_init_state(struct xfrm_state *x)
625 {
626 	struct crypto_aead *aead;
627 	u32 align;
628 	int err;
629 
630 	if (x->encap)
631 		return -EINVAL;
632 
633 	x->data = NULL;
634 
635 	if (x->aead)
636 		err = esp_init_aead(x);
637 	else
638 		err = esp_init_authenc(x);
639 
640 	if (err)
641 		goto error;
642 
643 	aead = x->data;
644 
645 	x->props.header_len = sizeof(struct ip_esp_hdr) +
646 			      crypto_aead_ivsize(aead);
647 	switch (x->props.mode) {
648 	case XFRM_MODE_BEET:
649 		if (x->sel.family != AF_INET6)
650 			x->props.header_len += IPV4_BEET_PHMAXLEN +
651 					       (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
652 		break;
653 	case XFRM_MODE_TRANSPORT:
654 		break;
655 	case XFRM_MODE_TUNNEL:
656 		x->props.header_len += sizeof(struct ipv6hdr);
657 		break;
658 	default:
659 		goto error;
660 	}
661 
662 	align = ALIGN(crypto_aead_blocksize(aead), 4);
663 	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
664 
665 error:
666 	return err;
667 }
668 
esp6_rcv_cb(struct sk_buff * skb,int err)669 static int esp6_rcv_cb(struct sk_buff *skb, int err)
670 {
671 	return 0;
672 }
673 
674 static const struct xfrm_type esp6_type = {
675 	.description	= "ESP6",
676 	.owner		= THIS_MODULE,
677 	.proto		= IPPROTO_ESP,
678 	.flags		= XFRM_TYPE_REPLAY_PROT,
679 	.init_state	= esp6_init_state,
680 	.destructor	= esp6_destroy,
681 	.get_mtu	= esp6_get_mtu,
682 	.input		= esp6_input,
683 	.output		= esp6_output,
684 	.hdr_offset	= xfrm6_find_1stfragopt,
685 };
686 
687 static struct xfrm6_protocol esp6_protocol = {
688 	.handler	=	xfrm6_rcv,
689 	.cb_handler	=	esp6_rcv_cb,
690 	.err_handler	=	esp6_err,
691 	.priority	=	0,
692 };
693 
esp6_init(void)694 static int __init esp6_init(void)
695 {
696 	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
697 		pr_info("%s: can't add xfrm type\n", __func__);
698 		return -EAGAIN;
699 	}
700 	if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
701 		pr_info("%s: can't add protocol\n", __func__);
702 		xfrm_unregister_type(&esp6_type, AF_INET6);
703 		return -EAGAIN;
704 	}
705 
706 	return 0;
707 }
708 
esp6_fini(void)709 static void __exit esp6_fini(void)
710 {
711 	if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
712 		pr_info("%s: can't remove protocol\n", __func__);
713 	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
714 		pr_info("%s: can't remove xfrm type\n", __func__);
715 }
716 
717 module_init(esp6_init);
718 module_exit(esp6_fini);
719 
720 MODULE_LICENSE("GPL");
721 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
722