xref: /openbmc/linux/net/ipv6/esp6.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
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_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_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 
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 
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. */
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 
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 
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 
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 	skb_to_sgvec(skb, sg,
252 		     (unsigned char *)esph - skb->data,
253 		     assoclen + ivlen + clen + alen);
254 
255 	aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
256 	aead_request_set_ad(req, assoclen);
257 
258 	seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
259 			    ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
260 
261 	memset(iv, 0, ivlen);
262 	memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
263 	       min(ivlen, 8));
264 
265 	ESP_SKB_CB(skb)->tmp = tmp;
266 	err = crypto_aead_encrypt(req);
267 
268 	switch (err) {
269 	case -EINPROGRESS:
270 		goto error;
271 
272 	case -EBUSY:
273 		err = NET_XMIT_DROP;
274 		break;
275 
276 	case 0:
277 		if ((x->props.flags & XFRM_STATE_ESN))
278 			esp_output_restore_header(skb);
279 	}
280 
281 	kfree(tmp);
282 
283 error:
284 	return err;
285 }
286 
287 static int esp_input_done2(struct sk_buff *skb, int err)
288 {
289 	struct xfrm_state *x = xfrm_input_state(skb);
290 	struct crypto_aead *aead = x->data;
291 	int alen = crypto_aead_authsize(aead);
292 	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
293 	int elen = skb->len - hlen;
294 	int hdr_len = skb_network_header_len(skb);
295 	int padlen;
296 	u8 nexthdr[2];
297 
298 	kfree(ESP_SKB_CB(skb)->tmp);
299 
300 	if (unlikely(err))
301 		goto out;
302 
303 	if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
304 		BUG();
305 
306 	err = -EINVAL;
307 	padlen = nexthdr[0];
308 	if (padlen + 2 + alen >= elen) {
309 		net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
310 				    padlen + 2, elen - alen);
311 		goto out;
312 	}
313 
314 	/* ... check padding bits here. Silly. :-) */
315 
316 	pskb_trim(skb, skb->len - alen - padlen - 2);
317 	__skb_pull(skb, hlen);
318 	if (x->props.mode == XFRM_MODE_TUNNEL)
319 		skb_reset_transport_header(skb);
320 	else
321 		skb_set_transport_header(skb, -hdr_len);
322 
323 	err = nexthdr[1];
324 
325 	/* RFC4303: Drop dummy packets without any error */
326 	if (err == IPPROTO_NONE)
327 		err = -EINVAL;
328 
329 out:
330 	return err;
331 }
332 
333 static void esp_input_done(struct crypto_async_request *base, int err)
334 {
335 	struct sk_buff *skb = base->data;
336 
337 	xfrm_input_resume(skb, esp_input_done2(skb, err));
338 }
339 
340 static void esp_input_restore_header(struct sk_buff *skb)
341 {
342 	esp_restore_header(skb, 0);
343 	__skb_pull(skb, 4);
344 }
345 
346 static void esp_input_done_esn(struct crypto_async_request *base, int err)
347 {
348 	struct sk_buff *skb = base->data;
349 
350 	esp_input_restore_header(skb);
351 	esp_input_done(base, err);
352 }
353 
354 static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
355 {
356 	struct ip_esp_hdr *esph;
357 	struct crypto_aead *aead = x->data;
358 	struct aead_request *req;
359 	struct sk_buff *trailer;
360 	int ivlen = crypto_aead_ivsize(aead);
361 	int elen = skb->len - sizeof(*esph) - ivlen;
362 	int nfrags;
363 	int assoclen;
364 	int seqhilen;
365 	int ret = 0;
366 	void *tmp;
367 	__be32 *seqhi;
368 	u8 *iv;
369 	struct scatterlist *sg;
370 
371 	if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
372 		ret = -EINVAL;
373 		goto out;
374 	}
375 
376 	if (elen <= 0) {
377 		ret = -EINVAL;
378 		goto out;
379 	}
380 
381 	nfrags = skb_cow_data(skb, 0, &trailer);
382 	if (nfrags < 0) {
383 		ret = -EINVAL;
384 		goto out;
385 	}
386 
387 	ret = -ENOMEM;
388 
389 	assoclen = sizeof(*esph);
390 	seqhilen = 0;
391 
392 	if (x->props.flags & XFRM_STATE_ESN) {
393 		seqhilen += sizeof(__be32);
394 		assoclen += seqhilen;
395 	}
396 
397 	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
398 	if (!tmp)
399 		goto out;
400 
401 	ESP_SKB_CB(skb)->tmp = tmp;
402 	seqhi = esp_tmp_seqhi(tmp);
403 	iv = esp_tmp_iv(aead, tmp, seqhilen);
404 	req = esp_tmp_req(aead, iv);
405 	sg = esp_req_sg(aead, req);
406 
407 	skb->ip_summed = CHECKSUM_NONE;
408 
409 	esph = (struct ip_esp_hdr *)skb->data;
410 
411 	aead_request_set_callback(req, 0, esp_input_done, skb);
412 
413 	/* For ESN we move the header forward by 4 bytes to
414 	 * accomodate the high bits.  We will move it back after
415 	 * decryption.
416 	 */
417 	if ((x->props.flags & XFRM_STATE_ESN)) {
418 		esph = (void *)skb_push(skb, 4);
419 		*seqhi = esph->spi;
420 		esph->spi = esph->seq_no;
421 		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
422 		aead_request_set_callback(req, 0, esp_input_done_esn, skb);
423 	}
424 
425 	sg_init_table(sg, nfrags);
426 	skb_to_sgvec(skb, sg, 0, skb->len);
427 
428 	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
429 	aead_request_set_ad(req, assoclen);
430 
431 	ret = crypto_aead_decrypt(req);
432 	if (ret == -EINPROGRESS)
433 		goto out;
434 
435 	if ((x->props.flags & XFRM_STATE_ESN))
436 		esp_input_restore_header(skb);
437 
438 	ret = esp_input_done2(skb, ret);
439 
440 out:
441 	return ret;
442 }
443 
444 static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
445 {
446 	struct crypto_aead *aead = x->data;
447 	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
448 	unsigned int net_adj;
449 
450 	if (x->props.mode != XFRM_MODE_TUNNEL)
451 		net_adj = sizeof(struct ipv6hdr);
452 	else
453 		net_adj = 0;
454 
455 	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
456 		 net_adj) & ~(blksize - 1)) + net_adj - 2;
457 }
458 
459 static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
460 		    u8 type, u8 code, int offset, __be32 info)
461 {
462 	struct net *net = dev_net(skb->dev);
463 	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
464 	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
465 	struct xfrm_state *x;
466 
467 	if (type != ICMPV6_PKT_TOOBIG &&
468 	    type != NDISC_REDIRECT)
469 		return 0;
470 
471 	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
472 			      esph->spi, IPPROTO_ESP, AF_INET6);
473 	if (!x)
474 		return 0;
475 
476 	if (type == NDISC_REDIRECT)
477 		ip6_redirect(skb, net, skb->dev->ifindex, 0,
478 			     sock_net_uid(net, NULL));
479 	else
480 		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
481 	xfrm_state_put(x);
482 
483 	return 0;
484 }
485 
486 static void esp6_destroy(struct xfrm_state *x)
487 {
488 	struct crypto_aead *aead = x->data;
489 
490 	if (!aead)
491 		return;
492 
493 	crypto_free_aead(aead);
494 }
495 
496 static int esp_init_aead(struct xfrm_state *x)
497 {
498 	char aead_name[CRYPTO_MAX_ALG_NAME];
499 	struct crypto_aead *aead;
500 	int err;
501 
502 	err = -ENAMETOOLONG;
503 	if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
504 		     x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
505 		goto error;
506 
507 	aead = crypto_alloc_aead(aead_name, 0, 0);
508 	err = PTR_ERR(aead);
509 	if (IS_ERR(aead))
510 		goto error;
511 
512 	x->data = aead;
513 
514 	err = crypto_aead_setkey(aead, x->aead->alg_key,
515 				 (x->aead->alg_key_len + 7) / 8);
516 	if (err)
517 		goto error;
518 
519 	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
520 	if (err)
521 		goto error;
522 
523 error:
524 	return err;
525 }
526 
527 static int esp_init_authenc(struct xfrm_state *x)
528 {
529 	struct crypto_aead *aead;
530 	struct crypto_authenc_key_param *param;
531 	struct rtattr *rta;
532 	char *key;
533 	char *p;
534 	char authenc_name[CRYPTO_MAX_ALG_NAME];
535 	unsigned int keylen;
536 	int err;
537 
538 	err = -EINVAL;
539 	if (!x->ealg)
540 		goto error;
541 
542 	err = -ENAMETOOLONG;
543 
544 	if ((x->props.flags & XFRM_STATE_ESN)) {
545 		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
546 			     "%s%sauthencesn(%s,%s)%s",
547 			     x->geniv ?: "", x->geniv ? "(" : "",
548 			     x->aalg ? x->aalg->alg_name : "digest_null",
549 			     x->ealg->alg_name,
550 			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
551 			goto error;
552 	} else {
553 		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
554 			     "%s%sauthenc(%s,%s)%s",
555 			     x->geniv ?: "", x->geniv ? "(" : "",
556 			     x->aalg ? x->aalg->alg_name : "digest_null",
557 			     x->ealg->alg_name,
558 			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
559 			goto error;
560 	}
561 
562 	aead = crypto_alloc_aead(authenc_name, 0, 0);
563 	err = PTR_ERR(aead);
564 	if (IS_ERR(aead))
565 		goto error;
566 
567 	x->data = aead;
568 
569 	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
570 		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
571 	err = -ENOMEM;
572 	key = kmalloc(keylen, GFP_KERNEL);
573 	if (!key)
574 		goto error;
575 
576 	p = key;
577 	rta = (void *)p;
578 	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
579 	rta->rta_len = RTA_LENGTH(sizeof(*param));
580 	param = RTA_DATA(rta);
581 	p += RTA_SPACE(sizeof(*param));
582 
583 	if (x->aalg) {
584 		struct xfrm_algo_desc *aalg_desc;
585 
586 		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
587 		p += (x->aalg->alg_key_len + 7) / 8;
588 
589 		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
590 		BUG_ON(!aalg_desc);
591 
592 		err = -EINVAL;
593 		if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
594 		    crypto_aead_authsize(aead)) {
595 			pr_info("ESP: %s digestsize %u != %hu\n",
596 				x->aalg->alg_name,
597 				crypto_aead_authsize(aead),
598 				aalg_desc->uinfo.auth.icv_fullbits / 8);
599 			goto free_key;
600 		}
601 
602 		err = crypto_aead_setauthsize(
603 			aead, x->aalg->alg_trunc_len / 8);
604 		if (err)
605 			goto free_key;
606 	}
607 
608 	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
609 	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
610 
611 	err = crypto_aead_setkey(aead, key, keylen);
612 
613 free_key:
614 	kfree(key);
615 
616 error:
617 	return err;
618 }
619 
620 static int esp6_init_state(struct xfrm_state *x)
621 {
622 	struct crypto_aead *aead;
623 	u32 align;
624 	int err;
625 
626 	if (x->encap)
627 		return -EINVAL;
628 
629 	x->data = NULL;
630 
631 	if (x->aead)
632 		err = esp_init_aead(x);
633 	else
634 		err = esp_init_authenc(x);
635 
636 	if (err)
637 		goto error;
638 
639 	aead = x->data;
640 
641 	x->props.header_len = sizeof(struct ip_esp_hdr) +
642 			      crypto_aead_ivsize(aead);
643 	switch (x->props.mode) {
644 	case XFRM_MODE_BEET:
645 		if (x->sel.family != AF_INET6)
646 			x->props.header_len += IPV4_BEET_PHMAXLEN +
647 					       (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
648 		break;
649 	case XFRM_MODE_TRANSPORT:
650 		break;
651 	case XFRM_MODE_TUNNEL:
652 		x->props.header_len += sizeof(struct ipv6hdr);
653 		break;
654 	default:
655 		goto error;
656 	}
657 
658 	align = ALIGN(crypto_aead_blocksize(aead), 4);
659 	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
660 
661 error:
662 	return err;
663 }
664 
665 static int esp6_rcv_cb(struct sk_buff *skb, int err)
666 {
667 	return 0;
668 }
669 
670 static const struct xfrm_type esp6_type = {
671 	.description	= "ESP6",
672 	.owner		= THIS_MODULE,
673 	.proto		= IPPROTO_ESP,
674 	.flags		= XFRM_TYPE_REPLAY_PROT,
675 	.init_state	= esp6_init_state,
676 	.destructor	= esp6_destroy,
677 	.get_mtu	= esp6_get_mtu,
678 	.input		= esp6_input,
679 	.output		= esp6_output,
680 	.hdr_offset	= xfrm6_find_1stfragopt,
681 };
682 
683 static struct xfrm6_protocol esp6_protocol = {
684 	.handler	=	xfrm6_rcv,
685 	.cb_handler	=	esp6_rcv_cb,
686 	.err_handler	=	esp6_err,
687 	.priority	=	0,
688 };
689 
690 static int __init esp6_init(void)
691 {
692 	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
693 		pr_info("%s: can't add xfrm type\n", __func__);
694 		return -EAGAIN;
695 	}
696 	if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
697 		pr_info("%s: can't add protocol\n", __func__);
698 		xfrm_unregister_type(&esp6_type, AF_INET6);
699 		return -EAGAIN;
700 	}
701 
702 	return 0;
703 }
704 
705 static void __exit esp6_fini(void)
706 {
707 	if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
708 		pr_info("%s: can't remove protocol\n", __func__);
709 	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
710 		pr_info("%s: can't remove xfrm type\n", __func__);
711 }
712 
713 module_init(esp6_init);
714 module_exit(esp6_fini);
715 
716 MODULE_LICENSE("GPL");
717 MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
718