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
 
 
 
 
 
 26#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
 27
 28static 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 */
 38static 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
 60static inline __be32 *esp_tmp_seqhi(void *tmp)
 61{
 62	return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
 63}
 64static 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
 71static 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
 82static 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
 92static 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
100static 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
108static 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
116static 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 sk_buff *trailer;
125	void *tmp;
126	u8 *iv;
127	u8 *tail;
128	int blksize;
129	int clen;
130	int alen;
131	int plen;
132	int tfclen;
133	int nfrags;
134	int assoclen;
135	int sglists;
136	int seqhilen;
137	__be32 *seqhi;
138
139	/* skb is pure payload to encrypt */
 
 
140
141	aead = x->data;
142	alen = crypto_aead_authsize(aead);
 
 
143
144	tfclen = 0;
145	if (x->tfcpad) {
146		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
147		u32 padto;
148
149		padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
150		if (skb->len < padto)
151			tfclen = padto - skb->len;
152	}
153	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
154	clen = ALIGN(skb->len + 2 + tfclen, blksize);
155	plen = clen - skb->len - tfclen;
 
 
 
 
 
156
157	err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
158	if (err < 0)
159		goto error;
160	nfrags = err;
 
 
 
 
 
 
 
161
162	assoclen = sizeof(*esph);
163	sglists = 1;
164	seqhilen = 0;
165
166	if (x->props.flags & XFRM_STATE_ESN) {
167		sglists += 2;
168		seqhilen += sizeof(__be32);
169		assoclen += seqhilen;
170	}
171
172	tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
173	if (!tmp) {
174		err = -ENOMEM;
175		goto error;
176	}
177
178	seqhi = esp_tmp_seqhi(tmp);
179	iv = esp_tmp_iv(aead, tmp, seqhilen);
180	req = esp_tmp_givreq(aead, iv);
181	asg = esp_givreq_sg(aead, req);
182	sg = asg + sglists;
183
 
 
184	/* Fill padding... */
185	tail = skb_tail_pointer(trailer);
186	if (tfclen) {
187		memset(tail, 0, tfclen);
188		tail += tfclen;
189	}
190	do {
191		int i;
192		for (i = 0; i < plen - 2; i++)
193			tail[i] = i + 1;
194	} while (0);
195	tail[plen - 2] = plen - 2;
196	tail[plen - 1] = *skb_mac_header(skb);
197	pskb_put(skb, trailer, clen - skb->len + alen);
198
199	skb_push(skb, -skb_network_offset(skb));
200	esph = ip_esp_hdr(skb);
201	*skb_mac_header(skb) = IPPROTO_ESP;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
202
203	/* this is non-NULL only with UDP Encapsulation */
204	if (x->encap) {
205		struct xfrm_encap_tmpl *encap = x->encap;
206		struct udphdr *uh;
207		__be32 *udpdata32;
208		__be16 sport, dport;
209		int encap_type;
210
211		spin_lock_bh(&x->lock);
212		sport = encap->encap_sport;
213		dport = encap->encap_dport;
214		encap_type = encap->encap_type;
215		spin_unlock_bh(&x->lock);
216
217		uh = (struct udphdr *)esph;
218		uh->source = sport;
219		uh->dest = dport;
220		uh->len = htons(skb->len - skb_transport_offset(skb));
221		uh->check = 0;
 
222
223		switch (encap_type) {
224		default:
225		case UDP_ENCAP_ESPINUDP:
226			esph = (struct ip_esp_hdr *)(uh + 1);
227			break;
228		case UDP_ENCAP_ESPINUDP_NON_IKE:
229			udpdata32 = (__be32 *)(uh + 1);
230			udpdata32[0] = udpdata32[1] = 0;
231			esph = (struct ip_esp_hdr *)(udpdata32 + 2);
232			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
233		}
234
235		*skb_mac_header(skb) = IPPROTO_UDP;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
236	}
237
238	esph->spi = x->id.spi;
239	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
 
 
240
241	sg_init_table(sg, nfrags);
242	skb_to_sgvec(skb, sg,
243		     esph->enc_data + crypto_aead_ivsize(aead) - skb->data,
244		     clen + alen);
245
246	if ((x->props.flags & XFRM_STATE_ESN)) {
247		sg_init_table(asg, 3);
248		sg_set_buf(asg, &esph->spi, sizeof(__be32));
249		*seqhi = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
250		sg_set_buf(asg + 1, seqhi, seqhilen);
251		sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
252	} else
253		sg_init_one(asg, esph, sizeof(*esph));
254
255	aead_givcrypt_set_callback(req, 0, esp_output_done, skb);
256	aead_givcrypt_set_crypt(req, sg, sg, clen, iv);
257	aead_givcrypt_set_assoc(req, asg, assoclen);
258	aead_givcrypt_set_giv(req, esph->enc_data,
259			      XFRM_SKB_CB(skb)->seq.output.low);
260
261	ESP_SKB_CB(skb)->tmp = tmp;
262	err = crypto_aead_givencrypt(req);
263	if (err == -EINPROGRESS)
 
 
264		goto error;
265
266	if (err == -EBUSY)
267		err = NET_XMIT_DROP;
 
268
269	kfree(tmp);
 
 
 
270
 
 
 
 
 
271error:
272	return err;
273}
 
274
275static int esp_input_done2(struct sk_buff *skb, int err)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
276{
277	const struct iphdr *iph;
278	struct xfrm_state *x = xfrm_input_state(skb);
 
279	struct crypto_aead *aead = x->data;
280	int alen = crypto_aead_authsize(aead);
281	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
282	int elen = skb->len - hlen;
283	int ihl;
284	u8 nexthdr[2];
285	int padlen;
286
287	kfree(ESP_SKB_CB(skb)->tmp);
 
 
288
289	if (unlikely(err))
 
290		goto out;
 
291
292	if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
293		BUG();
294
295	err = -EINVAL;
296	padlen = nexthdr[0];
297	if (padlen + 2 + alen >= elen)
 
 
298		goto out;
 
 
 
 
 
 
 
 
 
299
300	/* ... check padding bits here. Silly. :-) */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
301
302	iph = ip_hdr(skb);
303	ihl = iph->ihl * 4;
304
305	if (x->encap) {
306		struct xfrm_encap_tmpl *encap = x->encap;
307		struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
308
309		/*
310		 * 1) if the NAT-T peer's IP or port changed then
311		 *    advertize the change to the keying daemon.
312		 *    This is an inbound SA, so just compare
313		 *    SRC ports.
314		 */
315		if (iph->saddr != x->props.saddr.a4 ||
316		    uh->source != encap->encap_sport) {
317			xfrm_address_t ipaddr;
318
319			ipaddr.a4 = iph->saddr;
320			km_new_mapping(x, &ipaddr, uh->source);
321
322			/* XXX: perhaps add an extra
323			 * policy check here, to see
324			 * if we should allow or
325			 * reject a packet from a
326			 * different source
327			 * address/port.
328			 */
329		}
330
331		/*
332		 * 2) ignore UDP/TCP checksums in case
333		 *    of NAT-T in Transport Mode, or
334		 *    perform other post-processing fixes
335		 *    as per draft-ietf-ipsec-udp-encaps-06,
336		 *    section 3.1.2
337		 */
338		if (x->props.mode == XFRM_MODE_TRANSPORT)
339			skb->ip_summed = CHECKSUM_UNNECESSARY;
340	}
341
342	pskb_trim(skb, skb->len - alen - padlen - 2);
343	__skb_pull(skb, hlen);
344	if (x->props.mode == XFRM_MODE_TUNNEL)
345		skb_reset_transport_header(skb);
346	else
347		skb_set_transport_header(skb, -ihl);
348
349	err = nexthdr[1];
350
351	/* RFC4303: Drop dummy packets without any error */
352	if (err == IPPROTO_NONE)
353		err = -EINVAL;
354
355out:
356	return err;
357}
 
358
359static void esp_input_done(struct crypto_async_request *base, int err)
360{
361	struct sk_buff *skb = base->data;
362
363	xfrm_input_resume(skb, esp_input_done2(skb, err));
364}
365
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
366/*
367 * Note: detecting truncated vs. non-truncated authentication data is very
368 * expensive, so we only support truncated data, which is the recommended
369 * and common case.
370 */
371static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
372{
373	struct ip_esp_hdr *esph;
374	struct crypto_aead *aead = x->data;
375	struct aead_request *req;
376	struct sk_buff *trailer;
377	int elen = skb->len - sizeof(*esph) - crypto_aead_ivsize(aead);
 
378	int nfrags;
379	int assoclen;
380	int sglists;
381	int seqhilen;
382	__be32 *seqhi;
383	void *tmp;
384	u8 *iv;
385	struct scatterlist *sg;
386	struct scatterlist *asg;
387	int err = -EINVAL;
388
389	if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)))
390		goto out;
391
392	if (elen <= 0)
393		goto out;
394
395	if ((err = skb_cow_data(skb, 0, &trailer)) < 0)
396		goto out;
397	nfrags = err;
398
399	assoclen = sizeof(*esph);
400	sglists = 1;
401	seqhilen = 0;
402
403	if (x->props.flags & XFRM_STATE_ESN) {
404		sglists += 2;
405		seqhilen += sizeof(__be32);
406		assoclen += seqhilen;
407	}
408
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
409	err = -ENOMEM;
410	tmp = esp_alloc_tmp(aead, nfrags + sglists, seqhilen);
411	if (!tmp)
412		goto out;
413
414	ESP_SKB_CB(skb)->tmp = tmp;
415	seqhi = esp_tmp_seqhi(tmp);
416	iv = esp_tmp_iv(aead, tmp, seqhilen);
417	req = esp_tmp_req(aead, iv);
418	asg = esp_req_sg(aead, req);
419	sg = asg + sglists;
420
421	skb->ip_summed = CHECKSUM_NONE;
422
423	esph = (struct ip_esp_hdr *)skb->data;
 
 
 
 
 
424
425	/* Get ivec. This can be wrong, check against another impls. */
426	iv = esph->enc_data;
427
428	sg_init_table(sg, nfrags);
429	skb_to_sgvec(skb, sg, sizeof(*esph) + crypto_aead_ivsize(aead), elen);
 
 
430
431	if ((x->props.flags & XFRM_STATE_ESN)) {
432		sg_init_table(asg, 3);
433		sg_set_buf(asg, &esph->spi, sizeof(__be32));
434		*seqhi = XFRM_SKB_CB(skb)->seq.input.hi;
435		sg_set_buf(asg + 1, seqhi, seqhilen);
436		sg_set_buf(asg + 2, &esph->seq_no, sizeof(__be32));
437	} else
438		sg_init_one(asg, esph, sizeof(*esph));
439
440	aead_request_set_callback(req, 0, esp_input_done, skb);
441	aead_request_set_crypt(req, sg, sg, elen, iv);
442	aead_request_set_assoc(req, asg, assoclen);
443
444	err = crypto_aead_decrypt(req);
445	if (err == -EINPROGRESS)
446		goto out;
447
 
 
 
448	err = esp_input_done2(skb, err);
449
450out:
451	return err;
452}
453
454static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
455{
456	struct crypto_aead *aead = x->data;
457	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
458	unsigned int net_adj;
459
460	switch (x->props.mode) {
461	case XFRM_MODE_TRANSPORT:
462	case XFRM_MODE_BEET:
463		net_adj = sizeof(struct iphdr);
464		break;
465	case XFRM_MODE_TUNNEL:
466		net_adj = 0;
467		break;
468	default:
469		BUG();
470	}
471
472	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
473		 net_adj) & ~(blksize - 1)) + net_adj - 2;
474}
475
476static int esp4_err(struct sk_buff *skb, u32 info)
477{
478	struct net *net = dev_net(skb->dev);
479	const struct iphdr *iph = (const struct iphdr *)skb->data;
480	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
481	struct xfrm_state *x;
482
483	switch (icmp_hdr(skb)->type) {
484	case ICMP_DEST_UNREACH:
485		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
486			return 0;
487	case ICMP_REDIRECT:
488		break;
489	default:
490		return 0;
491	}
492
493	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
494			      esph->spi, IPPROTO_ESP, AF_INET);
495	if (!x)
496		return 0;
497
498	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
499		ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
500	else
501		ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
502	xfrm_state_put(x);
503
504	return 0;
505}
506
507static void esp_destroy(struct xfrm_state *x)
508{
509	struct crypto_aead *aead = x->data;
510
511	if (!aead)
512		return;
513
514	crypto_free_aead(aead);
515}
516
517static int esp_init_aead(struct xfrm_state *x)
518{
 
519	struct crypto_aead *aead;
520	int err;
521
522	aead = crypto_alloc_aead(x->aead->alg_name, 0, 0);
 
 
 
 
 
523	err = PTR_ERR(aead);
524	if (IS_ERR(aead))
525		goto error;
526
527	x->data = aead;
528
529	err = crypto_aead_setkey(aead, x->aead->alg_key,
530				 (x->aead->alg_key_len + 7) / 8);
531	if (err)
532		goto error;
533
534	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
535	if (err)
536		goto error;
537
538error:
539	return err;
540}
541
542static int esp_init_authenc(struct xfrm_state *x)
543{
544	struct crypto_aead *aead;
545	struct crypto_authenc_key_param *param;
546	struct rtattr *rta;
547	char *key;
548	char *p;
549	char authenc_name[CRYPTO_MAX_ALG_NAME];
550	unsigned int keylen;
551	int err;
552
553	err = -EINVAL;
554	if (x->ealg == NULL)
555		goto error;
556
557	err = -ENAMETOOLONG;
558
559	if ((x->props.flags & XFRM_STATE_ESN)) {
560		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
561			     "authencesn(%s,%s)",
 
562			     x->aalg ? x->aalg->alg_name : "digest_null",
563			     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 
564			goto error;
565	} else {
566		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
567			     "authenc(%s,%s)",
 
568			     x->aalg ? x->aalg->alg_name : "digest_null",
569			     x->ealg->alg_name) >= CRYPTO_MAX_ALG_NAME)
 
570			goto error;
571	}
572
573	aead = crypto_alloc_aead(authenc_name, 0, 0);
574	err = PTR_ERR(aead);
575	if (IS_ERR(aead))
576		goto error;
577
578	x->data = aead;
579
580	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
581		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
582	err = -ENOMEM;
583	key = kmalloc(keylen, GFP_KERNEL);
584	if (!key)
585		goto error;
586
587	p = key;
588	rta = (void *)p;
589	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
590	rta->rta_len = RTA_LENGTH(sizeof(*param));
591	param = RTA_DATA(rta);
592	p += RTA_SPACE(sizeof(*param));
593
594	if (x->aalg) {
595		struct xfrm_algo_desc *aalg_desc;
596
597		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
598		p += (x->aalg->alg_key_len + 7) / 8;
599
600		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
601		BUG_ON(!aalg_desc);
602
603		err = -EINVAL;
604		if (aalg_desc->uinfo.auth.icv_fullbits/8 !=
605		    crypto_aead_authsize(aead)) {
606			NETDEBUG(KERN_INFO "ESP: %s digestsize %u != %hu\n",
607				 x->aalg->alg_name,
608				 crypto_aead_authsize(aead),
609				 aalg_desc->uinfo.auth.icv_fullbits/8);
610			goto free_key;
611		}
612
613		err = crypto_aead_setauthsize(
614			aead, x->aalg->alg_trunc_len / 8);
615		if (err)
616			goto free_key;
617	}
618
619	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
620	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
621
622	err = crypto_aead_setkey(aead, key, keylen);
623
624free_key:
625	kfree(key);
626
627error:
628	return err;
629}
630
631static int esp_init_state(struct xfrm_state *x)
632{
633	struct crypto_aead *aead;
634	u32 align;
635	int err;
636
637	x->data = NULL;
638
639	if (x->aead)
640		err = esp_init_aead(x);
641	else
642		err = esp_init_authenc(x);
643
644	if (err)
645		goto error;
646
647	aead = x->data;
648
649	x->props.header_len = sizeof(struct ip_esp_hdr) +
650			      crypto_aead_ivsize(aead);
651	if (x->props.mode == XFRM_MODE_TUNNEL)
652		x->props.header_len += sizeof(struct iphdr);
653	else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
654		x->props.header_len += IPV4_BEET_PHMAXLEN;
655	if (x->encap) {
656		struct xfrm_encap_tmpl *encap = x->encap;
657
658		switch (encap->encap_type) {
659		default:
 
660			goto error;
661		case UDP_ENCAP_ESPINUDP:
662			x->props.header_len += sizeof(struct udphdr);
663			break;
664		case UDP_ENCAP_ESPINUDP_NON_IKE:
665			x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
666			break;
667		}
668	}
669
670	align = ALIGN(crypto_aead_blocksize(aead), 4);
671	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
672
673error:
674	return err;
675}
676
677static int esp4_rcv_cb(struct sk_buff *skb, int err)
678{
679	return 0;
680}
681
682static const struct xfrm_type esp_type =
683{
684	.description	= "ESP4",
685	.owner		= THIS_MODULE,
686	.proto	     	= IPPROTO_ESP,
687	.flags		= XFRM_TYPE_REPLAY_PROT,
688	.init_state	= esp_init_state,
689	.destructor	= esp_destroy,
690	.get_mtu	= esp4_get_mtu,
691	.input		= esp_input,
692	.output		= esp_output
693};
694
695static struct xfrm4_protocol esp4_protocol = {
696	.handler	=	xfrm4_rcv,
697	.input_handler	=	xfrm_input,
698	.cb_handler	=	esp4_rcv_cb,
699	.err_handler	=	esp4_err,
700	.priority	=	0,
701};
702
703static int __init esp4_init(void)
704{
705	if (xfrm_register_type(&esp_type, AF_INET) < 0) {
706		pr_info("%s: can't add xfrm type\n", __func__);
707		return -EAGAIN;
708	}
709	if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
710		pr_info("%s: can't add protocol\n", __func__);
711		xfrm_unregister_type(&esp_type, AF_INET);
712		return -EAGAIN;
713	}
714	return 0;
715}
716
717static void __exit esp4_fini(void)
718{
719	if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
720		pr_info("%s: can't remove protocol\n", __func__);
721	if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
722		pr_info("%s: can't remove xfrm type\n", __func__);
723}
724
725module_init(esp4_init);
726module_exit(esp4_fini);
727MODULE_LICENSE("GPL");
728MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);