1#define pr_fmt(fmt) "IPsec: " fmt
2
3#include <crypto/aead.h>
4#include <crypto/authenc.h>
5#include <linux/err.h>
6#include <linux/module.h>
7#include <net/ip.h>
8#include <net/xfrm.h>
9#include <net/esp.h>
10#include <linux/scatterlist.h>
11#include <linux/kernel.h>
12#include <linux/pfkeyv2.h>
13#include <linux/rtnetlink.h>
14#include <linux/slab.h>
15#include <linux/spinlock.h>
16#include <linux/in6.h>
17#include <net/icmp.h>
18#include <net/protocol.h>
19#include <net/udp.h>
20
21struct esp_skb_cb {
22 struct xfrm_skb_cb xfrm;
23 void *tmp;
24};
25
26struct esp_output_extra {
27 __be32 seqhi;
28 u32 esphoff;
29};
30
31#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
32
33static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
34
35
36
37
38
39
40
41
42
43static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
44{
45 unsigned int len;
46
47 len = extralen;
48
49 len += crypto_aead_ivsize(aead);
50
51 if (len) {
52 len += crypto_aead_alignmask(aead) &
53 ~(crypto_tfm_ctx_alignment() - 1);
54 len = ALIGN(len, crypto_tfm_ctx_alignment());
55 }
56
57 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
58 len = ALIGN(len, __alignof__(struct scatterlist));
59
60 len += sizeof(struct scatterlist) * nfrags;
61
62 return kmalloc(len, GFP_ATOMIC);
63}
64
65static inline void *esp_tmp_extra(void *tmp)
66{
67 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
68}
69
70static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
71{
72 return crypto_aead_ivsize(aead) ?
73 PTR_ALIGN((u8 *)tmp + extralen,
74 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
75}
76
77static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
78{
79 struct aead_request *req;
80
81 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
82 crypto_tfm_ctx_alignment());
83 aead_request_set_tfm(req, aead);
84 return req;
85}
86
87static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
88 struct aead_request *req)
89{
90 return (void *)ALIGN((unsigned long)(req + 1) +
91 crypto_aead_reqsize(aead),
92 __alignof__(struct scatterlist));
93}
94
95static void esp_output_done(struct crypto_async_request *base, int err)
96{
97 struct sk_buff *skb = base->data;
98
99 kfree(ESP_SKB_CB(skb)->tmp);
100 xfrm_output_resume(skb, err);
101}
102
103
104static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
105{
106 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
107 void *tmp = ESP_SKB_CB(skb)->tmp;
108 __be32 *seqhi = esp_tmp_extra(tmp);
109
110 esph->seq_no = esph->spi;
111 esph->spi = *seqhi;
112}
113
114static void esp_output_restore_header(struct sk_buff *skb)
115{
116 void *tmp = ESP_SKB_CB(skb)->tmp;
117 struct esp_output_extra *extra = esp_tmp_extra(tmp);
118
119 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
120 sizeof(__be32));
121}
122
123static void esp_output_done_esn(struct crypto_async_request *base, int err)
124{
125 struct sk_buff *skb = base->data;
126
127 esp_output_restore_header(skb);
128 esp_output_done(base, err);
129}
130
131static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
132{
133 int err;
134 struct esp_output_extra *extra;
135 struct ip_esp_hdr *esph;
136 struct crypto_aead *aead;
137 struct aead_request *req;
138 struct scatterlist *sg;
139 struct sk_buff *trailer;
140 void *tmp;
141 u8 *iv;
142 u8 *tail;
143 int blksize;
144 int clen;
145 int alen;
146 int plen;
147 int ivlen;
148 int tfclen;
149 int nfrags;
150 int assoclen;
151 int extralen;
152 __be64 seqno;
153
154
155
156 aead = x->data;
157 alen = crypto_aead_authsize(aead);
158 ivlen = crypto_aead_ivsize(aead);
159
160 tfclen = 0;
161 if (x->tfcpad) {
162 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
163 u32 padto;
164
165 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
166 if (skb->len < padto)
167 tfclen = padto - skb->len;
168 }
169 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
170 clen = ALIGN(skb->len + 2 + tfclen, blksize);
171 plen = clen - skb->len - tfclen;
172
173 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
174 if (err < 0)
175 goto error;
176 nfrags = err;
177
178 assoclen = sizeof(*esph);
179 extralen = 0;
180
181 if (x->props.flags & XFRM_STATE_ESN) {
182 extralen += sizeof(*extra);
183 assoclen += sizeof(__be32);
184 }
185
186 tmp = esp_alloc_tmp(aead, nfrags, extralen);
187 if (!tmp) {
188 err = -ENOMEM;
189 goto error;
190 }
191
192 extra = esp_tmp_extra(tmp);
193 iv = esp_tmp_iv(aead, tmp, extralen);
194 req = esp_tmp_req(aead, iv);
195 sg = esp_req_sg(aead, req);
196
197
198 tail = skb_tail_pointer(trailer);
199 if (tfclen) {
200 memset(tail, 0, tfclen);
201 tail += tfclen;
202 }
203 do {
204 int i;
205 for (i = 0; i < plen - 2; i++)
206 tail[i] = i + 1;
207 } while (0);
208 tail[plen - 2] = plen - 2;
209 tail[plen - 1] = *skb_mac_header(skb);
210 pskb_put(skb, trailer, clen - skb->len + alen);
211
212 skb_push(skb, -skb_network_offset(skb));
213 esph = ip_esp_hdr(skb);
214 *skb_mac_header(skb) = IPPROTO_ESP;
215
216
217 if (x->encap) {
218 struct xfrm_encap_tmpl *encap = x->encap;
219 struct udphdr *uh;
220 __be32 *udpdata32;
221 __be16 sport, dport;
222 int encap_type;
223
224 spin_lock_bh(&x->lock);
225 sport = encap->encap_sport;
226 dport = encap->encap_dport;
227 encap_type = encap->encap_type;
228 spin_unlock_bh(&x->lock);
229
230 uh = (struct udphdr *)esph;
231 uh->source = sport;
232 uh->dest = dport;
233 uh->len = htons(skb->len - skb_transport_offset(skb));
234 uh->check = 0;
235
236 switch (encap_type) {
237 default:
238 case UDP_ENCAP_ESPINUDP:
239 esph = (struct ip_esp_hdr *)(uh + 1);
240 break;
241 case UDP_ENCAP_ESPINUDP_NON_IKE:
242 udpdata32 = (__be32 *)(uh + 1);
243 udpdata32[0] = udpdata32[1] = 0;
244 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
245 break;
246 }
247
248 *skb_mac_header(skb) = IPPROTO_UDP;
249 }
250
251 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
252
253 aead_request_set_callback(req, 0, esp_output_done, skb);
254
255
256
257
258
259 if ((x->props.flags & XFRM_STATE_ESN)) {
260 extra->esphoff = (unsigned char *)esph -
261 skb_transport_header(skb);
262 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
263 extra->seqhi = esph->spi;
264 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
265 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
266 }
267
268 esph->spi = x->id.spi;
269
270 sg_init_table(sg, nfrags);
271 skb_to_sgvec(skb, sg,
272 (unsigned char *)esph - skb->data,
273 assoclen + ivlen + clen + alen);
274
275 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
276 aead_request_set_ad(req, assoclen);
277
278 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
279 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
280
281 memset(iv, 0, ivlen);
282 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
283 min(ivlen, 8));
284
285 ESP_SKB_CB(skb)->tmp = tmp;
286 err = crypto_aead_encrypt(req);
287
288 switch (err) {
289 case -EINPROGRESS:
290 goto error;
291
292 case -EBUSY:
293 err = NET_XMIT_DROP;
294 break;
295
296 case 0:
297 if ((x->props.flags & XFRM_STATE_ESN))
298 esp_output_restore_header(skb);
299 }
300
301 kfree(tmp);
302
303error:
304 return err;
305}
306
307static int esp_input_done2(struct sk_buff *skb, int err)
308{
309 const struct iphdr *iph;
310 struct xfrm_state *x = xfrm_input_state(skb);
311 struct crypto_aead *aead = x->data;
312 int alen = crypto_aead_authsize(aead);
313 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
314 int elen = skb->len - hlen;
315 int ihl;
316 u8 nexthdr[2];
317 int padlen;
318
319 kfree(ESP_SKB_CB(skb)->tmp);
320
321 if (unlikely(err))
322 goto out;
323
324 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
325 BUG();
326
327 err = -EINVAL;
328 padlen = nexthdr[0];
329 if (padlen + 2 + alen >= elen)
330 goto out;
331
332
333
334 iph = ip_hdr(skb);
335 ihl = iph->ihl * 4;
336
337 if (x->encap) {
338 struct xfrm_encap_tmpl *encap = x->encap;
339 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
340
341
342
343
344
345
346
347 if (iph->saddr != x->props.saddr.a4 ||
348 uh->source != encap->encap_sport) {
349 xfrm_address_t ipaddr;
350
351 ipaddr.a4 = iph->saddr;
352 km_new_mapping(x, &ipaddr, uh->source);
353
354
355
356
357
358
359
360
361 }
362
363
364
365
366
367
368
369
370 if (x->props.mode == XFRM_MODE_TRANSPORT)
371 skb->ip_summed = CHECKSUM_UNNECESSARY;
372 }
373
374 pskb_trim(skb, skb->len - alen - padlen - 2);
375 __skb_pull(skb, hlen);
376 if (x->props.mode == XFRM_MODE_TUNNEL)
377 skb_reset_transport_header(skb);
378 else
379 skb_set_transport_header(skb, -ihl);
380
381 err = nexthdr[1];
382
383
384 if (err == IPPROTO_NONE)
385 err = -EINVAL;
386
387out:
388 return err;
389}
390
391static void esp_input_done(struct crypto_async_request *base, int err)
392{
393 struct sk_buff *skb = base->data;
394
395 xfrm_input_resume(skb, esp_input_done2(skb, err));
396}
397
398static void esp_input_restore_header(struct sk_buff *skb)
399{
400 esp_restore_header(skb, 0);
401 __skb_pull(skb, 4);
402}
403
404static void esp_input_done_esn(struct crypto_async_request *base, int err)
405{
406 struct sk_buff *skb = base->data;
407
408 esp_input_restore_header(skb);
409 esp_input_done(base, err);
410}
411
412
413
414
415
416
417static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
418{
419 struct ip_esp_hdr *esph;
420 struct crypto_aead *aead = x->data;
421 struct aead_request *req;
422 struct sk_buff *trailer;
423 int ivlen = crypto_aead_ivsize(aead);
424 int elen = skb->len - sizeof(*esph) - ivlen;
425 int nfrags;
426 int assoclen;
427 int seqhilen;
428 __be32 *seqhi;
429 void *tmp;
430 u8 *iv;
431 struct scatterlist *sg;
432 int err = -EINVAL;
433
434 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
435 goto out;
436
437 if (elen <= 0)
438 goto out;
439
440 err = skb_cow_data(skb, 0, &trailer);
441 if (err < 0)
442 goto out;
443
444 nfrags = err;
445
446 assoclen = sizeof(*esph);
447 seqhilen = 0;
448
449 if (x->props.flags & XFRM_STATE_ESN) {
450 seqhilen += sizeof(__be32);
451 assoclen += seqhilen;
452 }
453
454 err = -ENOMEM;
455 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
456 if (!tmp)
457 goto out;
458
459 ESP_SKB_CB(skb)->tmp = tmp;
460 seqhi = esp_tmp_extra(tmp);
461 iv = esp_tmp_iv(aead, tmp, seqhilen);
462 req = esp_tmp_req(aead, iv);
463 sg = esp_req_sg(aead, req);
464
465 skb->ip_summed = CHECKSUM_NONE;
466
467 esph = (struct ip_esp_hdr *)skb->data;
468
469 aead_request_set_callback(req, 0, esp_input_done, skb);
470
471
472
473
474
475 if ((x->props.flags & XFRM_STATE_ESN)) {
476 esph = (void *)skb_push(skb, 4);
477 *seqhi = esph->spi;
478 esph->spi = esph->seq_no;
479 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
480 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
481 }
482
483 sg_init_table(sg, nfrags);
484 skb_to_sgvec(skb, sg, 0, skb->len);
485
486 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
487 aead_request_set_ad(req, assoclen);
488
489 err = crypto_aead_decrypt(req);
490 if (err == -EINPROGRESS)
491 goto out;
492
493 if ((x->props.flags & XFRM_STATE_ESN))
494 esp_input_restore_header(skb);
495
496 err = esp_input_done2(skb, err);
497
498out:
499 return err;
500}
501
502static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
503{
504 struct crypto_aead *aead = x->data;
505 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
506 unsigned int net_adj;
507
508 switch (x->props.mode) {
509 case XFRM_MODE_TRANSPORT:
510 case XFRM_MODE_BEET:
511 net_adj = sizeof(struct iphdr);
512 break;
513 case XFRM_MODE_TUNNEL:
514 net_adj = 0;
515 break;
516 default:
517 BUG();
518 }
519
520 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
521 net_adj) & ~(blksize - 1)) + net_adj - 2;
522}
523
524static int esp4_err(struct sk_buff *skb, u32 info)
525{
526 struct net *net = dev_net(skb->dev);
527 const struct iphdr *iph = (const struct iphdr *)skb->data;
528 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
529 struct xfrm_state *x;
530
531 switch (icmp_hdr(skb)->type) {
532 case ICMP_DEST_UNREACH:
533 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
534 return 0;
535 case ICMP_REDIRECT:
536 break;
537 default:
538 return 0;
539 }
540
541 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
542 esph->spi, IPPROTO_ESP, AF_INET);
543 if (!x)
544 return 0;
545
546 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
547 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
548 else
549 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
550 xfrm_state_put(x);
551
552 return 0;
553}
554
555static void esp_destroy(struct xfrm_state *x)
556{
557 struct crypto_aead *aead = x->data;
558
559 if (!aead)
560 return;
561
562 crypto_free_aead(aead);
563}
564
565static int esp_init_aead(struct xfrm_state *x)
566{
567 char aead_name[CRYPTO_MAX_ALG_NAME];
568 struct crypto_aead *aead;
569 int err;
570
571 err = -ENAMETOOLONG;
572 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
573 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
574 goto error;
575
576 aead = crypto_alloc_aead(aead_name, 0, 0);
577 err = PTR_ERR(aead);
578 if (IS_ERR(aead))
579 goto error;
580
581 x->data = aead;
582
583 err = crypto_aead_setkey(aead, x->aead->alg_key,
584 (x->aead->alg_key_len + 7) / 8);
585 if (err)
586 goto error;
587
588 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
589 if (err)
590 goto error;
591
592error:
593 return err;
594}
595
596static int esp_init_authenc(struct xfrm_state *x)
597{
598 struct crypto_aead *aead;
599 struct crypto_authenc_key_param *param;
600 struct rtattr *rta;
601 char *key;
602 char *p;
603 char authenc_name[CRYPTO_MAX_ALG_NAME];
604 unsigned int keylen;
605 int err;
606
607 err = -EINVAL;
608 if (!x->ealg)
609 goto error;
610
611 err = -ENAMETOOLONG;
612
613 if ((x->props.flags & XFRM_STATE_ESN)) {
614 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
615 "%s%sauthencesn(%s,%s)%s",
616 x->geniv ?: "", x->geniv ? "(" : "",
617 x->aalg ? x->aalg->alg_name : "digest_null",
618 x->ealg->alg_name,
619 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
620 goto error;
621 } else {
622 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
623 "%s%sauthenc(%s,%s)%s",
624 x->geniv ?: "", x->geniv ? "(" : "",
625 x->aalg ? x->aalg->alg_name : "digest_null",
626 x->ealg->alg_name,
627 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
628 goto error;
629 }
630
631 aead = crypto_alloc_aead(authenc_name, 0, 0);
632 err = PTR_ERR(aead);
633 if (IS_ERR(aead))
634 goto error;
635
636 x->data = aead;
637
638 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
639 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
640 err = -ENOMEM;
641 key = kmalloc(keylen, GFP_KERNEL);
642 if (!key)
643 goto error;
644
645 p = key;
646 rta = (void *)p;
647 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
648 rta->rta_len = RTA_LENGTH(sizeof(*param));
649 param = RTA_DATA(rta);
650 p += RTA_SPACE(sizeof(*param));
651
652 if (x->aalg) {
653 struct xfrm_algo_desc *aalg_desc;
654
655 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
656 p += (x->aalg->alg_key_len + 7) / 8;
657
658 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
659 BUG_ON(!aalg_desc);
660
661 err = -EINVAL;
662 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
663 crypto_aead_authsize(aead)) {
664 pr_info("ESP: %s digestsize %u != %hu\n",
665 x->aalg->alg_name,
666 crypto_aead_authsize(aead),
667 aalg_desc->uinfo.auth.icv_fullbits / 8);
668 goto free_key;
669 }
670
671 err = crypto_aead_setauthsize(
672 aead, x->aalg->alg_trunc_len / 8);
673 if (err)
674 goto free_key;
675 }
676
677 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
678 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
679
680 err = crypto_aead_setkey(aead, key, keylen);
681
682free_key:
683 kfree(key);
684
685error:
686 return err;
687}
688
689static int esp_init_state(struct xfrm_state *x)
690{
691 struct crypto_aead *aead;
692 u32 align;
693 int err;
694
695 x->data = NULL;
696
697 if (x->aead)
698 err = esp_init_aead(x);
699 else
700 err = esp_init_authenc(x);
701
702 if (err)
703 goto error;
704
705 aead = x->data;
706
707 x->props.header_len = sizeof(struct ip_esp_hdr) +
708 crypto_aead_ivsize(aead);
709 if (x->props.mode == XFRM_MODE_TUNNEL)
710 x->props.header_len += sizeof(struct iphdr);
711 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
712 x->props.header_len += IPV4_BEET_PHMAXLEN;
713 if (x->encap) {
714 struct xfrm_encap_tmpl *encap = x->encap;
715
716 switch (encap->encap_type) {
717 default:
718 goto error;
719 case UDP_ENCAP_ESPINUDP:
720 x->props.header_len += sizeof(struct udphdr);
721 break;
722 case UDP_ENCAP_ESPINUDP_NON_IKE:
723 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
724 break;
725 }
726 }
727
728 align = ALIGN(crypto_aead_blocksize(aead), 4);
729 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
730
731error:
732 return err;
733}
734
735static int esp4_rcv_cb(struct sk_buff *skb, int err)
736{
737 return 0;
738}
739
740static const struct xfrm_type esp_type =
741{
742 .description = "ESP4",
743 .owner = THIS_MODULE,
744 .proto = IPPROTO_ESP,
745 .flags = XFRM_TYPE_REPLAY_PROT,
746 .init_state = esp_init_state,
747 .destructor = esp_destroy,
748 .get_mtu = esp4_get_mtu,
749 .input = esp_input,
750 .output = esp_output
751};
752
753static struct xfrm4_protocol esp4_protocol = {
754 .handler = xfrm4_rcv,
755 .input_handler = xfrm_input,
756 .cb_handler = esp4_rcv_cb,
757 .err_handler = esp4_err,
758 .priority = 0,
759};
760
761static int __init esp4_init(void)
762{
763 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
764 pr_info("%s: can't add xfrm type\n", __func__);
765 return -EAGAIN;
766 }
767 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
768 pr_info("%s: can't add protocol\n", __func__);
769 xfrm_unregister_type(&esp_type, AF_INET);
770 return -EAGAIN;
771 }
772 return 0;
773}
774
775static void __exit esp4_fini(void)
776{
777 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
778 pr_info("%s: can't remove protocol\n", __func__);
779 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
780 pr_info("%s: can't remove xfrm type\n", __func__);
781}
782
783module_init(esp4_init);
784module_exit(esp4_fini);
785MODULE_LICENSE("GPL");
786MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
787
