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tcp: dont drop MTU reduction indications
[linux-2.6/btrfs-unstable.git] / net / ipv4 / esp4.c
blobb61e9deb7c7ecc9cae92ab0365b871a773627cc4
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
21 struct esp_skb_cb {
22 struct xfrm_skb_cb xfrm;
23 void *tmp;
24 };
25
26 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
27
28 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
29
30 /*
31 * Allocate an AEAD request structure with extra space for SG and IV.
32 *
33 * For alignment considerations the IV is placed at the front, followed
34 * by the request and finally the SG list.
35 *
36 * TODO: Use spare space in skb for this where possible.
37 */
38 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqhilen)
39 {
40 unsigned int len;
41
42 len = seqhilen;
43
44 len += crypto_aead_ivsize(aead);
45
46 if (len) {
47 len += crypto_aead_alignmask(aead) &
48 ~(crypto_tfm_ctx_alignment() - 1);
49 len = ALIGN(len, crypto_tfm_ctx_alignment());
50 }
51
52 len += sizeof(struct aead_givcrypt_request) + crypto_aead_reqsize(aead);
53 len = ALIGN(len, __alignof__(struct scatterlist));
54
55 len += sizeof(struct scatterlist) * nfrags;
56
57 return kmalloc(len, GFP_ATOMIC);
58 }
59
60 static inline __be32 *esp_tmp_seqhi(void *tmp)
61 {
62 return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
63 }
64 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
65 {
66 return crypto_aead_ivsize(aead) ?
67 PTR_ALIGN((u8 *)tmp + seqhilen,
68 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
69 }
70
71 static inline struct aead_givcrypt_request *esp_tmp_givreq(
72 struct crypto_aead *aead, u8 *iv)
73 {
74 struct aead_givcrypt_request *req;
75
76 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
77 crypto_tfm_ctx_alignment());
78 aead_givcrypt_set_tfm(req, aead);
79 return req;
80 }
81
82 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
83 {
84 struct aead_request *req;
85
86 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
87 crypto_tfm_ctx_alignment());
88 aead_request_set_tfm(req, aead);
89 return req;
90 }
91
92 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
93 struct aead_request *req)
94 {
95 return (void *)ALIGN((unsigned long)(req + 1) +
96 crypto_aead_reqsize(aead),
97 __alignof__(struct scatterlist));
98 }
99
100 static inline struct scatterlist *esp_givreq_sg(
101 struct crypto_aead *aead, struct aead_givcrypt_request *req)
102 {
103 return (void *)ALIGN((unsigned long)(req + 1) +
104 crypto_aead_reqsize(aead),
105 __alignof__(struct scatterlist));
106 }
107
108 static void esp_output_done(struct crypto_async_request *base, int err)
109 {
110 struct sk_buff *skb = base->data;
111
112 kfree(ESP_SKB_CB(skb)->tmp);
113 xfrm_output_resume(skb, err);
114 }
115
116 static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
117 {
118 int err;
119 struct ip_esp_hdr *esph;
120 struct crypto_aead *aead;
121 struct aead_givcrypt_request *req;
122 struct scatterlist *sg;
123 struct scatterlist *asg;
124 struct esp_data *esp;
125 struct sk_buff *trailer;
126 void *tmp;
127 u8 *iv;
128 u8 *tail;
129 int blksize;
130 int clen;
131 int alen;
132 int plen;
133 int tfclen;
134 int nfrags;
135 int assoclen;
136 int sglists;
137 int seqhilen;
138 __be32 *seqhi;
139
140 /* skb is pure payload to encrypt */
141
142 err = -ENOMEM;
143
144 esp = x->data;
145 aead = esp->aead;
146 alen = crypto_aead_authsize(aead);
147
148 tfclen = 0;
149 if (x->tfcpad) {
150 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
151 u32 padto;
152
153 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
154 if (skb->len < padto)
155 tfclen = padto - skb->len;
156 }
157 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
158 clen = ALIGN(skb->len + 2 + tfclen, blksize);
159 if (esp->padlen)
160 clen = ALIGN(clen, esp->padlen);
161 plen = clen - skb->len - tfclen;
162
163 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
164 if (err < 0)
165 goto error;
166 nfrags = err;
167
168 assoclen = sizeof(*esph);
169 sglists = 1;
170 seqhilen = 0;
171
172 if (x->props.flags & XFRM_STATE_ESN) {
173 sglists += 2;
174 seqhilen += sizeof(__be32);
175 assoclen += seqhilen;
176 }
177
178 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
179 if (!tmp)
180 goto error;
181
182 seqhi = esp_tmp_seqhi(tmp);
183 iv = esp_tmp_iv(aead, tmp, seqhilen);
184 req = esp_tmp_givreq(aead, iv);
185 asg = esp_givreq_sg(aead, req);
186 sg = asg + sglists;
187
188 /* Fill padding... */
189 tail = skb_tail_pointer(trailer);
190 if (tfclen) {
191 memset(tail, 0, tfclen);
192 tail += tfclen;
193 }
194 do {
195 int i;
196 for (i = 0; i < plen - 2; i++)
197 tail[i] = i + 1;
198 } while (0);
199 tail[plen - 2] = plen - 2;
200 tail[plen - 1] = *skb_mac_header(skb);
201 pskb_put(skb, trailer, clen - skb->len + alen);
202
203 skb_push(skb, -skb_network_offset(skb));
204 esph = ip_esp_hdr(skb);
205 *skb_mac_header(skb) = IPPROTO_ESP;
206
207 /* this is non-NULL only with UDP Encapsulation */
208 if (x->encap) {
209 struct xfrm_encap_tmpl *encap = x->encap;
210 struct udphdr *uh;
211 __be32 *udpdata32;
212 __be16 sport, dport;
213 int encap_type;
214
215 spin_lock_bh(&x->lock);
216 sport = encap->encap_sport;
217 dport = encap->encap_dport;
218 encap_type = encap->encap_type;
219 spin_unlock_bh(&x->lock);
220
221 uh = (struct udphdr *)esph;
222 uh->source = sport;
223 uh->dest = dport;
224 uh->len = htons(skb->len - skb_transport_offset(skb));
225 uh->check = 0;
226
227 switch (encap_type) {
228 default:
229 case UDP_ENCAP_ESPINUDP:
230 esph = (struct ip_esp_hdr *)(uh + 1);
231 break;
232 case UDP_ENCAP_ESPINUDP_NON_IKE:
233 udpdata32 = (__be32 *)(uh + 1);
234 udpdata32[0] = udpdata32[1] = 0;
235 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
236 break;
237 }
238
239 *skb_mac_header(skb) = IPPROTO_UDP;
240 }
241
242 esph->spi = x->id.spi;
243 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
244
245 sg_init_table(sg, nfrags);
246 skb_to_sgvec(skb, sg,
247 esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
248 clen + alen);
249
250 if ((x->props.flags & XFRM_STATE_ESN)) {
251 sg_init_table(asg, 3);
252 sg_set_buf(asg, &esph->spi, sizeof(__be32));
253 *seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
254 sg_set_buf(asg + 1, seqhi, seqhilen);
255 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
256 } else
257 sg_init_one(asg, esph, sizeof(*esph));
258
259 aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
260 aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
261 aead_givcrypt_set_assoc(req, asg, assoclen);
262 aead_givcrypt_set_giv(req, esph->enc_data,
263 XFRM_SKB_CB(skb)->seq.output.low);
264
265 ESP_SKB_CB(skb)->tmp = tmp;
266 err = crypto_aead_givencrypt(req);
267 if (err == -EINPROGRESS)
268 goto error;
269
270 if (err == -EBUSY)
271 err = NET_XMIT_DROP;
272
273 kfree(tmp);
274
275 error:
276 return err;
277 }
278
279 static int esp_input_done2(struct sk_buff *skb, int err)
280 {
281 const struct iphdr *iph;
282 struct xfrm_state *x = xfrm_input_state(skb);
283 struct esp_data *esp = x->data;
284 struct crypto_aead *aead = esp->aead;
285 int alen = crypto_aead_authsize(aead);
286 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
287 int elen = skb->len - hlen;
288 int ihl;
289 u8 nexthdr[2];
290 int padlen;
291
292 kfree(ESP_SKB_CB(skb)->tmp);
293
294 if (unlikely(err))
295 goto out;
296
297 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
298 BUG();
299
300 err = -EINVAL;
301 padlen = nexthdr[0];
302 if (padlen + 2 + alen >= elen)
303 goto out;
304
305 /* ... check padding bits here. Silly. :-) */
306
307 iph = ip_hdr(skb);
308 ihl = iph->ihl * 4;
309
310 if (x->encap) {
311 struct xfrm_encap_tmpl *encap = x->encap;
312 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
313
314 /*
315 * 1) if the NAT-T peer's IP or port changed then
316 * advertize the change to the keying daemon.
317 * This is an inbound SA, so just compare
318 * SRC ports.
319 */
320 if (iph->saddr != x->props.saddr.a4 ||
321 uh->source != encap->encap_sport) {
322 xfrm_address_t ipaddr;
323
324 ipaddr.a4 = iph->saddr;
325 km_new_mapping(x, &ipaddr, uh->source);
326
327 /* XXX: perhaps add an extra
328 * policy check here, to see
329 * if we should allow or
330 * reject a packet from a
331 * different source
332 * address/port.
333 */
334 }
335
336 /*
337 * 2) ignore UDP/TCP checksums in case
338 * of NAT-T in Transport Mode, or
339 * perform other post-processing fixes
340 * as per draft-ietf-ipsec-udp-encaps-06,
341 * section 3.1.2
342 */
343 if (x->props.mode == XFRM_MODE_TRANSPORT)
344 skb->ip_summed = CHECKSUM_UNNECESSARY;
345 }
346
347 pskb_trim(skb, skb->len - alen - padlen - 2);
348 __skb_pull(skb, hlen);
349 skb_set_transport_header(skb, -ihl);
350
351 err = nexthdr[1];
352
353 /* RFC4303: Drop dummy packets without any error */
354 if (err == IPPROTO_NONE)
355 err = -EINVAL;
356
357 out:
358 return err;
359 }
360
361 static void esp_input_done(struct crypto_async_request *base, int err)
362 {
363 struct sk_buff *skb = base->data;
364
365 xfrm_input_resume(skb, esp_input_done2(skb, err));
366 }
367
368 /*
369 * Note: detecting truncated vs. non-truncated authentication data is very
370 * expensive, so we only support truncated data, which is the recommended
371 * and common case.
372 */
373 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
374 {
375 struct ip_esp_hdr *esph;
376 struct esp_data *esp = x->data;
377 struct crypto_aead *aead = esp->aead;
378 struct aead_request *req;
379 struct sk_buff *trailer;
380 int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
381 int nfrags;
382 int assoclen;
383 int sglists;
384 int seqhilen;
385 __be32 *seqhi;
386 void *tmp;
387 u8 *iv;
388 struct scatterlist *sg;
389 struct scatterlist *asg;
390 int err = -EINVAL;
391
392 if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
393 goto out;
394
395 if (elen <= 0)
396 goto out;
397
398 if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
399 goto out;
400 nfrags = err;
401
402 assoclen = sizeof(*esph);
403 sglists = 1;
404 seqhilen = 0;
405
406 if (x->props.flags & XFRM_STATE_ESN) {
407 sglists += 2;
408 seqhilen += sizeof(__be32);
409 assoclen += seqhilen;
410 }
411
412 err = -ENOMEM;
413 tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
414 if (!tmp)
415 goto out;
416
417 ESP_SKB_CB(skb)->tmp = tmp;
418 seqhi = esp_tmp_seqhi(tmp);
419 iv = esp_tmp_iv(aead, tmp, seqhilen);
420 req = esp_tmp_req(aead, iv);
421 asg = esp_req_sg(aead, req);
422 sg = asg + sglists;
423
424 skb->ip_summed = CHECKSUM_NONE;
425
426 esph = (struct ip_esp_hdr *)skb->data;
427
428 /* Get ivec. This can be wrong, check against another impls. */
429 iv = esph->enc_data;
430
431 sg_init_table(sg, nfrags);
432 skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
433
434 if ((x->props.flags & XFRM_STATE_ESN)) {
435 sg_init_table(asg, 3);
436 sg_set_buf(asg, &esph->spi, sizeof(__be32));
437 *seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
438 sg_set_buf(asg + 1, seqhi, seqhilen);
439 sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
440 } else
441 sg_init_one(asg, esph, sizeof(*esph));
442
443 aead_request_set_callback(req, 0, esp_input_done, skb);
444 aead_request_set_crypt(req, sg, sg, elen, iv);
445 aead_request_set_assoc(req, asg, assoclen);
446
447 err = crypto_aead_decrypt(req);
448 if (err == -EINPROGRESS)
449 goto out;
450
451 err = esp_input_done2(skb, err);
452
453 out:
454 return err;
455 }
456
457 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
458 {
459 struct esp_data *esp = x->data;
460 u32 blksize = ALIGN(crypto_aead_blocksize(esp->aead), 4);
461 u32 align = max_t(u32, blksize, esp->padlen);
462 unsigned int net_adj;
463
464 switch (x->props.mode) {
465 case XFRM_MODE_TRANSPORT:
466 case XFRM_MODE_BEET:
467 net_adj = sizeof(struct iphdr);
468 break;
469 case XFRM_MODE_TUNNEL:
470 net_adj = 0;
471 break;
472 default:
473 BUG();
474 }
475
476 return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
477 net_adj) & ~(align - 1)) + (net_adj - 2);
478 }
479
480 static void esp4_err(struct sk_buff *skb, u32 info)
481 {
482 struct net *net = dev_net(skb->dev);
483 const struct iphdr *iph = (const struct iphdr *)skb->data;
484 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
485 struct xfrm_state *x;
486
487 switch (icmp_hdr(skb)->type) {
488 case ICMP_DEST_UNREACH:
489 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
490 return;
491 case ICMP_REDIRECT:
492 break;
493 default:
494 return;
495 }
496
497 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
498 esph->spi, IPPROTO_ESP, AF_INET);
499 if (!x)
500 return;
501
502 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
503 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
504 else
505 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
506 xfrm_state_put(x);
507 }
508
509 static void esp_destroy(struct xfrm_state *x)
510 {
511 struct esp_data *esp = x->data;
512
513 if (!esp)
514 return;
515
516 crypto_free_aead(esp->aead);
517 kfree(esp);
518 }
519
520 static int esp_init_aead(struct xfrm_state *x)
521 {
522 struct esp_data *esp = x->data;
523 struct crypto_aead *aead;
524 int err;
525
526 aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
527 err = PTR_ERR(aead);
528 if (IS_ERR(aead))
529 goto error;
530
531 esp->aead = aead;
532
533 err = crypto_aead_setkey(aead, x->aead->alg_key,
534 (x->aead->alg_key_len + 7) / 8);
535 if (err)
536 goto error;
537
538 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
539 if (err)
540 goto error;
541
542 error:
543 return err;
544 }
545
546 static int esp_init_authenc(struct xfrm_state *x)
547 {
548 struct esp_data *esp = x->data;
549 struct crypto_aead *aead;
550 struct crypto_authenc_key_param *param;
551 struct rtattr *rta;
552 char *key;
553 char *p;
554 char authenc_name[CRYPTO_MAX_ALG_NAME];
555 unsigned int keylen;
556 int err;
557
558 err = -EINVAL;
559 if (x->ealg == NULL)
560 goto error;
561
562 err = -ENAMETOOLONG;
563
564 if ((x->props.flags & XFRM_STATE_ESN)) {
565 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
566 "authencesn(%s,%s)",
567 x->aalg ? x->aalg->alg_name : "digest_null",
568 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
569 goto error;
570 } else {
571 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
572 "authenc(%s,%s)",
573 x->aalg ? x->aalg->alg_name : "digest_null",
574 x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
575 goto error;
576 }
577
578 aead = crypto_alloc_aead(authenc_name, 0, 0);
579 err = PTR_ERR(aead);
580 if (IS_ERR(aead))
581 goto error;
582
583 esp->aead = aead;
584
585 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
586 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
587 err = -ENOMEM;
588 key = kmalloc(keylen, GFP_KERNEL);
589 if (!key)
590 goto error;
591
592 p = key;
593 rta = (void *)p;
594 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
595 rta->rta_len = RTA_LENGTH(sizeof(*param));
596 param = RTA_DATA(rta);
597 p += RTA_SPACE(sizeof(*param));
598
599 if (x->aalg) {
600 struct xfrm_algo_desc *aalg_desc;
601
602 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
603 p += (x->aalg->alg_key_len + 7) / 8;
604
605 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
606 BUG_ON(!aalg_desc);
607
608 err = -EINVAL;
609 if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
610 crypto_aead_authsize(aead)) {
611 NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
612 x->aalg->alg_name,
613 crypto_aead_authsize(aead),
614 aalg_desc->uinfo.auth.icv_fullbits/8);
615 goto free_key;
616 }
617
618 err = crypto_aead_setauthsize(
619 aead, x->aalg->alg_trunc_len / 8);
620 if (err)
621 goto free_key;
622 }
623
624 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
625 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
626
627 err = crypto_aead_setkey(aead, key, keylen);
628
629 free_key:
630 kfree(key);
631
632 error:
633 return err;
634 }
635
636 static int esp_init_state(struct xfrm_state *x)
637 {
638 struct esp_data *esp;
639 struct crypto_aead *aead;
640 u32 align;
641 int err;
642
643 esp = kzalloc(sizeof(*esp), GFP_KERNEL);
644 if (esp == NULL)
645 return -ENOMEM;
646
647 x->data = esp;
648
649 if (x->aead)
650 err = esp_init_aead(x);
651 else
652 err = esp_init_authenc(x);
653
654 if (err)
655 goto error;
656
657 aead = esp->aead;
658
659 esp->padlen = 0;
660
661 x->props.header_len = sizeof(struct ip_esp_hdr) +
662 crypto_aead_ivsize(aead);
663 if (x->props.mode == XFRM_MODE_TUNNEL)
664 x->props.header_len += sizeof(struct iphdr);
665 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
666 x->props.header_len += IPV4_BEET_PHMAXLEN;
667 if (x->encap) {
668 struct xfrm_encap_tmpl *encap = x->encap;
669
670 switch (encap->encap_type) {
671 default:
672 goto error;
673 case UDP_ENCAP_ESPINUDP:
674 x->props.header_len += sizeof(struct udphdr);
675 break;
676 case UDP_ENCAP_ESPINUDP_NON_IKE:
677 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
678 break;
679 }
680 }
681
682 align = ALIGN(crypto_aead_blocksize(aead), 4);
683 if (esp->padlen)
684 align = max_t(u32, align, esp->padlen);
685 x->props.trailer_len = align + 1 + crypto_aead_authsize(esp->aead);
686
687 error:
688 return err;
689 }
690
691 static const struct xfrm_type esp_type =
692 {
693 .description = "ESP4",
694 .owner = THIS_MODULE,
695 .proto = IPPROTO_ESP,
696 .flags = XFRM_TYPE_REPLAY_PROT,
697 .init_state = esp_init_state,
698 .destructor = esp_destroy,
699 .get_mtu = esp4_get_mtu,
700 .input = esp_input,
701 .output = esp_output
702 };
703
704 static const struct net_protocol esp4_protocol = {
705 .handler = xfrm4_rcv,
706 .err_handler = esp4_err,
707 .no_policy = 1,
708 .netns_ok = 1,
709 };
710
711 static int __init esp4_init(void)
712 {
713 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
714 pr_info("%s: can't add xfrm type\n", __func__);
715 return -EAGAIN;
716 }
717 if (inet_add_protocol(&esp4_protocol, IPPROTO_ESP) < 0) {
718 pr_info("%s: can't add protocol\n", __func__);
719 xfrm_unregister_type(&esp_type, AF_INET);
720 return -EAGAIN;
721 }
722 return 0;
723 }
724
725 static void __exit esp4_fini(void)
726 {
727 if (inet_del_protocol(&esp4_protocol, IPPROTO_ESP) < 0)
728 pr_info("%s: can't remove protocol\n", __func__);
729 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
730 pr_info("%s: can't remove xfrm type\n", __func__);
731 }
732
733 module_init(esp4_init);
734 module_exit(esp4_fini);
735 MODULE_LICENSE("GPL");
736 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
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