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#include <linux/highmem.h>
 48
 49struct esp_skb_cb {
 50	struct xfrm_skb_cb xfrm;
 51	void *tmp;
 52};
 53
 54#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
 55
 56static u32 esp6_get_mtu(struct xfrm_state *x, int mtu);
 57
 58/*
 59 * Allocate an AEAD request structure with extra space for SG and IV.
 60 *
 61 * For alignment considerations the upper 32 bits of the sequence number are
 62 * placed at the front, if present. Followed by the IV, the request and finally
 63 * the SG list.
 64 *
 65 * TODO: Use spare space in skb for this where possible.
 66 */
 67static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
 68{
 69	unsigned int len;
 70
 71	len = seqihlen;
 72
 73	len += crypto_aead_ivsize(aead);
 74
 75	if (len) {
 76		len += crypto_aead_alignmask(aead) &
 77		       ~(crypto_tfm_ctx_alignment() - 1);
 78		len = ALIGN(len, crypto_tfm_ctx_alignment());
 79	}
 80
 81	len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
 82	len = ALIGN(len, __alignof__(struct scatterlist));
 83
 84	len += sizeof(struct scatterlist) * nfrags;
 85
 86	return kmalloc(len, GFP_ATOMIC);
 87}
 88
 89static inline __be32 *esp_tmp_seqhi(void *tmp)
 90{
 91	return PTR_ALIGN((__be32 *)tmp, __alignof__(__be32));
 92}
 93
 94static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
 95{
 96	return crypto_aead_ivsize(aead) ?
 97	       PTR_ALIGN((u8 *)tmp + seqhilen,
 98			 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
 99}
100
101static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
102{
103	struct aead_request *req;
104
105	req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
106				crypto_tfm_ctx_alignment());
107	aead_request_set_tfm(req, aead);
108	return req;
109}
110
111static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
112					     struct aead_request *req)
113{
114	return (void *)ALIGN((unsigned long)(req + 1) +
115			     crypto_aead_reqsize(aead),
116			     __alignof__(struct scatterlist));
117}
118
119static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
120{
121	struct crypto_aead *aead = x->data;
122	int seqhilen = 0;
123	u8 *iv;
124	struct aead_request *req;
125	struct scatterlist *sg;
126
127	if (x->props.flags & XFRM_STATE_ESN)
128		seqhilen += sizeof(__be32);
129
130	iv = esp_tmp_iv(aead, tmp, seqhilen);
131	req = esp_tmp_req(aead, iv);
132
133	/* Unref skb_frag_pages in the src scatterlist if necessary.
134	 * Skip the first sg which comes from skb->data.
135	 */
136	if (req->src != req->dst)
137		for (sg = sg_next(req->src); sg; sg = sg_next(sg))
138			put_page(sg_page(sg));
139}
140
141static void esp_output_done(struct crypto_async_request *base, int err)
142{
143	struct sk_buff *skb = base->data;
144	struct xfrm_offload *xo = xfrm_offload(skb);
145	void *tmp;
146	struct xfrm_state *x;
147
148	if (xo && (xo->flags & XFRM_DEV_RESUME))
149		x = skb->sp->xvec[skb->sp->len - 1];
150	else
151		x = skb_dst(skb)->xfrm;
152
153	tmp = ESP_SKB_CB(skb)->tmp;
154	esp_ssg_unref(x, tmp);
155	kfree(tmp);
156
157	if (xo && (xo->flags & XFRM_DEV_RESUME)) {
158		if (err) {
159			XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
160			kfree_skb(skb);
161			return;
162		}
163
164		skb_push(skb, skb->data - skb_mac_header(skb));
165		secpath_reset(skb);
166		xfrm_dev_resume(skb);
167	} else {
168		xfrm_output_resume(skb, err);
169	}
170}
171
172/* Move ESP header back into place. */
173static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
174{
175	struct ip_esp_hdr *esph = (void *)(skb->data + offset);
176	void *tmp = ESP_SKB_CB(skb)->tmp;
177	__be32 *seqhi = esp_tmp_seqhi(tmp);
178
179	esph->seq_no = esph->spi;
180	esph->spi = *seqhi;
181}
182
183static void esp_output_restore_header(struct sk_buff *skb)
184{
185	esp_restore_header(skb, skb_transport_offset(skb) - sizeof(__be32));
186}
187
188static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
189					     struct xfrm_state *x,
190					     struct ip_esp_hdr *esph,
191					     __be32 *seqhi)
192{
193	/* For ESN we move the header forward by 4 bytes to
194	 * accomodate the high bits.  We will move it back after
195	 * encryption.
196	 */
197	if ((x->props.flags & XFRM_STATE_ESN)) {
198		struct xfrm_offload *xo = xfrm_offload(skb);
199
200		esph = (void *)(skb_transport_header(skb) - sizeof(__be32));
201		*seqhi = esph->spi;
202		if (xo)
203			esph->seq_no = htonl(xo->seq.hi);
204		else
205			esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
206	}
207
208	esph->spi = x->id.spi;
209
210	return esph;
211}
212
213static void esp_output_done_esn(struct crypto_async_request *base, int err)
214{
215	struct sk_buff *skb = base->data;
216
217	esp_output_restore_header(skb);
218	esp_output_done(base, err);
219}
220
221static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
222{
223	/* Fill padding... */
224	if (tfclen) {
225		memset(tail, 0, tfclen);
226		tail += tfclen;
227	}
228	do {
229		int i;
230		for (i = 0; i < plen - 2; i++)
231			tail[i] = i + 1;
232	} while (0);
233	tail[plen - 2] = plen - 2;
234	tail[plen - 1] = proto;
235}
236
237int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
238{
239	u8 *tail;
240	u8 *vaddr;
241	int nfrags;
242	struct page *page;
 
243	struct sk_buff *trailer;
244	int tailen = esp->tailen;
245
246	if (!skb_cloned(skb)) {
247		if (tailen <= skb_tailroom(skb)) {
248			nfrags = 1;
249			trailer = skb;
250			tail = skb_tail_pointer(trailer);
251
252			goto skip_cow;
253		} else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
254			   && !skb_has_frag_list(skb)) {
255			int allocsize;
256			struct sock *sk = skb->sk;
257			struct page_frag *pfrag = &x->xfrag;
258
259			esp->inplace = false;
260
261			allocsize = ALIGN(tailen, L1_CACHE_BYTES);
262
263			spin_lock_bh(&x->lock);
264
265			if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
266				spin_unlock_bh(&x->lock);
267				goto cow;
268			}
269
270			page = pfrag->page;
271			get_page(page);
272
273			vaddr = kmap_atomic(page);
274
275			tail = vaddr + pfrag->offset;
276
277			esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
278
279			kunmap_atomic(vaddr);
280
281			nfrags = skb_shinfo(skb)->nr_frags;
282
283			__skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
284					     tailen);
285			skb_shinfo(skb)->nr_frags = ++nfrags;
286
287			pfrag->offset = pfrag->offset + allocsize;
288
289			spin_unlock_bh(&x->lock);
290
291			nfrags++;
292
293			skb->len += tailen;
294			skb->data_len += tailen;
295			skb->truesize += tailen;
296			if (sk)
297				refcount_add(tailen, &sk->sk_wmem_alloc);
298
299			goto out;
300		}
301	}
302
303cow:
304	nfrags = skb_cow_data(skb, tailen, &trailer);
305	if (nfrags < 0)
306		goto out;
307	tail = skb_tail_pointer(trailer);
308
309skip_cow:
310	esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
311	pskb_put(skb, trailer, tailen);
312
313out:
314	return nfrags;
315}
316EXPORT_SYMBOL_GPL(esp6_output_head);
317
318int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
319{
320	u8 *iv;
321	int alen;
322	void *tmp;
 
 
 
 
323	int ivlen;
 
 
324	int assoclen;
325	int seqhilen;
 
 
326	__be32 *seqhi;
327	struct page *page;
328	struct ip_esp_hdr *esph;
329	struct aead_request *req;
330	struct crypto_aead *aead;
331	struct scatterlist *sg, *dsg;
332	int err = -ENOMEM;
333
334	assoclen = sizeof(struct ip_esp_hdr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
335	seqhilen = 0;
336
337	if (x->props.flags & XFRM_STATE_ESN) {
338		seqhilen += sizeof(__be32);
339		assoclen += sizeof(__be32);
340	}
341
342	aead = x->data;
343	alen = crypto_aead_authsize(aead);
344	ivlen = crypto_aead_ivsize(aead);
345
346	tmp = esp_alloc_tmp(aead, esp->nfrags + 2, seqhilen);
347	if (!tmp)
348		goto error;
 
349
350	seqhi = esp_tmp_seqhi(tmp);
351	iv = esp_tmp_iv(aead, tmp, seqhilen);
352	req = esp_tmp_req(aead, iv);
353	sg = esp_req_sg(aead, req);
354
355	if (esp->inplace)
356		dsg = sg;
357	else
358		dsg = &sg[esp->nfrags];
 
 
 
 
 
 
 
 
 
 
359
360	esph = esp_output_set_esn(skb, x, ip_esp_hdr(skb), seqhi);
 
 
361
362	sg_init_table(sg, esp->nfrags);
363	err = skb_to_sgvec(skb, sg,
364		           (unsigned char *)esph - skb->data,
365		           assoclen + ivlen + esp->clen + alen);
366	if (unlikely(err < 0))
367		goto error_free;
368
369	if (!esp->inplace) {
370		int allocsize;
371		struct page_frag *pfrag = &x->xfrag;
372
373		allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
374
375		spin_lock_bh(&x->lock);
376		if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
377			spin_unlock_bh(&x->lock);
378			goto error_free;
379		}
380
381		skb_shinfo(skb)->nr_frags = 1;
382
383		page = pfrag->page;
384		get_page(page);
385		/* replace page frags in skb with new page */
386		__skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
387		pfrag->offset = pfrag->offset + allocsize;
388		spin_unlock_bh(&x->lock);
389
390		sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
391		err = skb_to_sgvec(skb, dsg,
392			           (unsigned char *)esph - skb->data,
393			           assoclen + ivlen + esp->clen + alen);
394		if (unlikely(err < 0))
395			goto error_free;
396	}
397
398	if ((x->props.flags & XFRM_STATE_ESN))
399		aead_request_set_callback(req, 0, esp_output_done_esn, skb);
400	else
401		aead_request_set_callback(req, 0, esp_output_done, skb);
402
403	aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
 
 
 
 
 
404	aead_request_set_ad(req, assoclen);
405
 
 
 
406	memset(iv, 0, ivlen);
407	memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
408	       min(ivlen, 8));
409
410	ESP_SKB_CB(skb)->tmp = tmp;
411	err = crypto_aead_encrypt(req);
412
413	switch (err) {
414	case -EINPROGRESS:
415		goto error;
416
417	case -ENOSPC:
418		err = NET_XMIT_DROP;
419		break;
420
421	case 0:
422		if ((x->props.flags & XFRM_STATE_ESN))
423			esp_output_restore_header(skb);
424	}
425
426	if (sg != dsg)
427		esp_ssg_unref(x, tmp);
428
429error_free:
430	kfree(tmp);
 
431error:
432	return err;
433}
434EXPORT_SYMBOL_GPL(esp6_output_tail);
435
436static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
437{
438	int alen;
439	int blksize;
440	struct ip_esp_hdr *esph;
441	struct crypto_aead *aead;
442	struct esp_info esp;
443
444	esp.inplace = true;
445
446	esp.proto = *skb_mac_header(skb);
447	*skb_mac_header(skb) = IPPROTO_ESP;
448
449	/* skb is pure payload to encrypt */
450
451	aead = x->data;
452	alen = crypto_aead_authsize(aead);
453
454	esp.tfclen = 0;
455	if (x->tfcpad) {
456		struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
457		u32 padto;
458
459		padto = min(x->tfcpad, esp6_get_mtu(x, dst->child_mtu_cached));
460		if (skb->len < padto)
461			esp.tfclen = padto - skb->len;
462	}
463	blksize = ALIGN(crypto_aead_blocksize(aead), 4);
464	esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
465	esp.plen = esp.clen - skb->len - esp.tfclen;
466	esp.tailen = esp.tfclen + esp.plen + alen;
467
468	esp.nfrags = esp6_output_head(x, skb, &esp);
469	if (esp.nfrags < 0)
470		return esp.nfrags;
471
472	esph = ip_esp_hdr(skb);
473	esph->spi = x->id.spi;
474
475	esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
476	esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
477			    ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
478
479	skb_push(skb, -skb_network_offset(skb));
480
481	return esp6_output_tail(x, skb, &esp);
482}
483
484static inline int esp_remove_trailer(struct sk_buff *skb)
485{
486	struct xfrm_state *x = xfrm_input_state(skb);
487	struct xfrm_offload *xo = xfrm_offload(skb);
488	struct crypto_aead *aead = x->data;
489	int alen, hlen, elen;
490	int padlen, trimlen;
491	__wsum csumdiff;
 
 
492	u8 nexthdr[2];
493	int ret;
494
495	alen = crypto_aead_authsize(aead);
496	hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
497	elen = skb->len - hlen;
498
499	if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
500		ret = xo->proto;
501		goto out;
502	}
503
504	ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
505	BUG_ON(ret);
506
507	ret = -EINVAL;
508	padlen = nexthdr[0];
509	if (padlen + 2 + alen >= elen) {
510		net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
511				    padlen + 2, elen - alen);
512		goto out;
513	}
514
515	trimlen = alen + padlen + 2;
516	if (skb->ip_summed == CHECKSUM_COMPLETE) {
517		csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
518		skb->csum = csum_block_sub(skb->csum, csumdiff,
519					   skb->len - trimlen);
520	}
521	pskb_trim(skb, skb->len - trimlen);
522
523	ret = nexthdr[1];
524
525out:
526	return ret;
527}
528
529int esp6_input_done2(struct sk_buff *skb, int err)
530{
531	struct xfrm_state *x = xfrm_input_state(skb);
532	struct xfrm_offload *xo = xfrm_offload(skb);
533	struct crypto_aead *aead = x->data;
534	int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
535	int hdr_len = skb_network_header_len(skb);
536
537	if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
538		kfree(ESP_SKB_CB(skb)->tmp);
539
540	if (unlikely(err))
541		goto out;
542
543	err = esp_remove_trailer(skb);
544	if (unlikely(err < 0))
545		goto out;
546
547	skb_postpull_rcsum(skb, skb_network_header(skb),
548			   skb_network_header_len(skb));
549	skb_pull_rcsum(skb, hlen);
550	if (x->props.mode == XFRM_MODE_TUNNEL)
551		skb_reset_transport_header(skb);
552	else
553		skb_set_transport_header(skb, -hdr_len);
554
 
 
555	/* RFC4303: Drop dummy packets without any error */
556	if (err == IPPROTO_NONE)
557		err = -EINVAL;
558
559out:
560	return err;
561}
562EXPORT_SYMBOL_GPL(esp6_input_done2);
563
564static void esp_input_done(struct crypto_async_request *base, int err)
565{
566	struct sk_buff *skb = base->data;
567
568	xfrm_input_resume(skb, esp6_input_done2(skb, err));
569}
570
571static void esp_input_restore_header(struct sk_buff *skb)
572{
573	esp_restore_header(skb, 0);
574	__skb_pull(skb, 4);
575}
576
577static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
578{
579	struct xfrm_state *x = xfrm_input_state(skb);
580
581	/* For ESN we move the header forward by 4 bytes to
582	 * accomodate the high bits.  We will move it back after
583	 * decryption.
584	 */
585	if ((x->props.flags & XFRM_STATE_ESN)) {
586		struct ip_esp_hdr *esph = skb_push(skb, 4);
587
588		*seqhi = esph->spi;
589		esph->spi = esph->seq_no;
590		esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
591	}
592}
593
594static void esp_input_done_esn(struct crypto_async_request *base, int err)
595{
596	struct sk_buff *skb = base->data;
597
598	esp_input_restore_header(skb);
599	esp_input_done(base, err);
600}
601
602static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
603{
604	struct ip_esp_hdr *esph;
605	struct crypto_aead *aead = x->data;
606	struct aead_request *req;
607	struct sk_buff *trailer;
608	int ivlen = crypto_aead_ivsize(aead);
609	int elen = skb->len - sizeof(*esph) - ivlen;
610	int nfrags;
611	int assoclen;
612	int seqhilen;
613	int ret = 0;
614	void *tmp;
615	__be32 *seqhi;
616	u8 *iv;
617	struct scatterlist *sg;
618
619	if (!pskb_may_pull(skb, sizeof(*esph) + ivlen)) {
620		ret = -EINVAL;
621		goto out;
622	}
623
624	if (elen <= 0) {
625		ret = -EINVAL;
626		goto out;
627	}
628
 
 
 
 
 
 
 
 
629	assoclen = sizeof(*esph);
630	seqhilen = 0;
631
632	if (x->props.flags & XFRM_STATE_ESN) {
633		seqhilen += sizeof(__be32);
634		assoclen += seqhilen;
635	}
636
637	if (!skb_cloned(skb)) {
638		if (!skb_is_nonlinear(skb)) {
639			nfrags = 1;
640
641			goto skip_cow;
642		} else if (!skb_has_frag_list(skb)) {
643			nfrags = skb_shinfo(skb)->nr_frags;
644			nfrags++;
645
646			goto skip_cow;
647		}
648	}
649
650	nfrags = skb_cow_data(skb, 0, &trailer);
651	if (nfrags < 0) {
652		ret = -EINVAL;
653		goto out;
654	}
655
656skip_cow:
657	ret = -ENOMEM;
658	tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
659	if (!tmp)
660		goto out;
661
662	ESP_SKB_CB(skb)->tmp = tmp;
663	seqhi = esp_tmp_seqhi(tmp);
664	iv = esp_tmp_iv(aead, tmp, seqhilen);
665	req = esp_tmp_req(aead, iv);
666	sg = esp_req_sg(aead, req);
667
668	esp_input_set_header(skb, seqhi);
669
670	sg_init_table(sg, nfrags);
671	ret = skb_to_sgvec(skb, sg, 0, skb->len);
672	if (unlikely(ret < 0))
673		goto out;
674
675	skb->ip_summed = CHECKSUM_NONE;
676
677	if ((x->props.flags & XFRM_STATE_ESN))
 
 
 
 
 
 
 
 
678		aead_request_set_callback(req, 0, esp_input_done_esn, skb);
679	else
680		aead_request_set_callback(req, 0, esp_input_done, skb);
 
 
681
682	aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
683	aead_request_set_ad(req, assoclen);
684
685	ret = crypto_aead_decrypt(req);
686	if (ret == -EINPROGRESS)
687		goto out;
688
689	if ((x->props.flags & XFRM_STATE_ESN))
690		esp_input_restore_header(skb);
691
692	ret = esp6_input_done2(skb, ret);
693
694out:
695	return ret;
696}
697
698static u32 esp6_get_mtu(struct xfrm_state *x, int mtu)
699{
700	struct crypto_aead *aead = x->data;
701	u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
702	unsigned int net_adj;
703
704	if (x->props.mode != XFRM_MODE_TUNNEL)
705		net_adj = sizeof(struct ipv6hdr);
706	else
707		net_adj = 0;
708
709	return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
710		 net_adj) & ~(blksize - 1)) + net_adj - 2;
711}
712
713static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
714		    u8 type, u8 code, int offset, __be32 info)
715{
716	struct net *net = dev_net(skb->dev);
717	const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
718	struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
719	struct xfrm_state *x;
720
721	if (type != ICMPV6_PKT_TOOBIG &&
722	    type != NDISC_REDIRECT)
723		return 0;
724
725	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
726			      esph->spi, IPPROTO_ESP, AF_INET6);
727	if (!x)
728		return 0;
729
730	if (type == NDISC_REDIRECT)
731		ip6_redirect(skb, net, skb->dev->ifindex, 0,
732			     sock_net_uid(net, NULL));
733	else
734		ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
735	xfrm_state_put(x);
736
737	return 0;
738}
739
740static void esp6_destroy(struct xfrm_state *x)
741{
742	struct crypto_aead *aead = x->data;
743
744	if (!aead)
745		return;
746
747	crypto_free_aead(aead);
748}
749
750static int esp_init_aead(struct xfrm_state *x)
751{
752	char aead_name[CRYPTO_MAX_ALG_NAME];
753	struct crypto_aead *aead;
754	int err;
755
756	err = -ENAMETOOLONG;
757	if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
758		     x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
759		goto error;
760
761	aead = crypto_alloc_aead(aead_name, 0, 0);
762	err = PTR_ERR(aead);
763	if (IS_ERR(aead))
764		goto error;
765
766	x->data = aead;
767
768	err = crypto_aead_setkey(aead, x->aead->alg_key,
769				 (x->aead->alg_key_len + 7) / 8);
770	if (err)
771		goto error;
772
773	err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
774	if (err)
775		goto error;
776
777error:
778	return err;
779}
780
781static int esp_init_authenc(struct xfrm_state *x)
782{
783	struct crypto_aead *aead;
784	struct crypto_authenc_key_param *param;
785	struct rtattr *rta;
786	char *key;
787	char *p;
788	char authenc_name[CRYPTO_MAX_ALG_NAME];
789	unsigned int keylen;
790	int err;
791
792	err = -EINVAL;
793	if (!x->ealg)
794		goto error;
795
796	err = -ENAMETOOLONG;
797
798	if ((x->props.flags & XFRM_STATE_ESN)) {
799		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
800			     "%s%sauthencesn(%s,%s)%s",
801			     x->geniv ?: "", x->geniv ? "(" : "",
802			     x->aalg ? x->aalg->alg_name : "digest_null",
803			     x->ealg->alg_name,
804			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
805			goto error;
806	} else {
807		if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
808			     "%s%sauthenc(%s,%s)%s",
809			     x->geniv ?: "", x->geniv ? "(" : "",
810			     x->aalg ? x->aalg->alg_name : "digest_null",
811			     x->ealg->alg_name,
812			     x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
813			goto error;
814	}
815
816	aead = crypto_alloc_aead(authenc_name, 0, 0);
817	err = PTR_ERR(aead);
818	if (IS_ERR(aead))
819		goto error;
820
821	x->data = aead;
822
823	keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
824		 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
825	err = -ENOMEM;
826	key = kmalloc(keylen, GFP_KERNEL);
827	if (!key)
828		goto error;
829
830	p = key;
831	rta = (void *)p;
832	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
833	rta->rta_len = RTA_LENGTH(sizeof(*param));
834	param = RTA_DATA(rta);
835	p += RTA_SPACE(sizeof(*param));
836
837	if (x->aalg) {
838		struct xfrm_algo_desc *aalg_desc;
839
840		memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
841		p += (x->aalg->alg_key_len + 7) / 8;
842
843		aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
844		BUG_ON(!aalg_desc);
845
846		err = -EINVAL;
847		if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
848		    crypto_aead_authsize(aead)) {
849			pr_info("ESP: %s digestsize %u != %hu\n",
850				x->aalg->alg_name,
851				crypto_aead_authsize(aead),
852				aalg_desc->uinfo.auth.icv_fullbits / 8);
853			goto free_key;
854		}
855
856		err = crypto_aead_setauthsize(
857			aead, x->aalg->alg_trunc_len / 8);
858		if (err)
859			goto free_key;
860	}
861
862	param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
863	memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
864
865	err = crypto_aead_setkey(aead, key, keylen);
866
867free_key:
868	kfree(key);
869
870error:
871	return err;
872}
873
874static int esp6_init_state(struct xfrm_state *x)
875{
876	struct crypto_aead *aead;
877	u32 align;
878	int err;
879
880	if (x->encap)
881		return -EINVAL;
882
883	x->data = NULL;
884
885	if (x->aead)
886		err = esp_init_aead(x);
887	else
888		err = esp_init_authenc(x);
889
890	if (err)
891		goto error;
892
893	aead = x->data;
894
895	x->props.header_len = sizeof(struct ip_esp_hdr) +
896			      crypto_aead_ivsize(aead);
897	switch (x->props.mode) {
898	case XFRM_MODE_BEET:
899		if (x->sel.family != AF_INET6)
900			x->props.header_len += IPV4_BEET_PHMAXLEN +
901					       (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
902		break;
903	default:
904	case XFRM_MODE_TRANSPORT:
905		break;
906	case XFRM_MODE_TUNNEL:
907		x->props.header_len += sizeof(struct ipv6hdr);
908		break;
 
 
909	}
910
911	align = ALIGN(crypto_aead_blocksize(aead), 4);
912	x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
913
914error:
915	return err;
916}
917
918static int esp6_rcv_cb(struct sk_buff *skb, int err)
919{
920	return 0;
921}
922
923static const struct xfrm_type esp6_type = {
924	.description	= "ESP6",
925	.owner		= THIS_MODULE,
926	.proto		= IPPROTO_ESP,
927	.flags		= XFRM_TYPE_REPLAY_PROT,
928	.init_state	= esp6_init_state,
929	.destructor	= esp6_destroy,
930	.get_mtu	= esp6_get_mtu,
931	.input		= esp6_input,
932	.output		= esp6_output,
933	.hdr_offset	= xfrm6_find_1stfragopt,
934};
935
936static struct xfrm6_protocol esp6_protocol = {
937	.handler	=	xfrm6_rcv,
938	.cb_handler	=	esp6_rcv_cb,
939	.err_handler	=	esp6_err,
940	.priority	=	0,
941};
942
943static int __init esp6_init(void)
944{
945	if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
946		pr_info("%s: can't add xfrm type\n", __func__);
947		return -EAGAIN;
948	}
949	if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
950		pr_info("%s: can't add protocol\n", __func__);
951		xfrm_unregister_type(&esp6_type, AF_INET6);
952		return -EAGAIN;
953	}
954
955	return 0;
956}
957
958static void __exit esp6_fini(void)
959{
960	if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
961		pr_info("%s: can't remove protocol\n", __func__);
962	if (xfrm_unregister_type(&esp6_type, AF_INET6) < 0)
963		pr_info("%s: can't remove xfrm type\n", __func__);
964}
965
966module_init(esp6_init);
967module_exit(esp6_fini);
968
969MODULE_LICENSE("GPL");
970MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);