Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C)2002 USAGI/WIDE Project
4 *
5 * Authors
6 *
7 * Mitsuru KANDA @USAGI : IPv6 Support
8 * Kazunori MIYAZAWA @USAGI :
9 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
10 *
11 * This file is derived from net/ipv4/esp.c
12 */
13
14#define pr_fmt(fmt) "IPv6: " fmt
15
16#include <crypto/aead.h>
17#include <crypto/authenc.h>
18#include <linux/err.h>
19#include <linux/module.h>
20#include <net/ip.h>
21#include <net/xfrm.h>
22#include <net/esp.h>
23#include <linux/scatterlist.h>
24#include <linux/kernel.h>
25#include <linux/pfkeyv2.h>
26#include <linux/random.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29#include <net/ip6_checksum.h>
30#include <net/ip6_route.h>
31#include <net/icmp.h>
32#include <net/ipv6.h>
33#include <net/protocol.h>
34#include <net/udp.h>
35#include <linux/icmpv6.h>
36#include <net/tcp.h>
37#include <net/espintcp.h>
38#include <net/inet6_hashtables.h>
39
40#include <linux/highmem.h>
41
42struct esp_skb_cb {
43 struct xfrm_skb_cb xfrm;
44 void *tmp;
45};
46
47struct esp_output_extra {
48 __be32 seqhi;
49 u32 esphoff;
50};
51
52#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
53
54/*
55 * Allocate an AEAD request structure with extra space for SG and IV.
56 *
57 * For alignment considerations the upper 32 bits of the sequence number are
58 * placed at the front, if present. Followed by the IV, the request and finally
59 * the SG list.
60 *
61 * TODO: Use spare space in skb for this where possible.
62 */
63static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int seqihlen)
64{
65 unsigned int len;
66
67 len = seqihlen;
68
69 len += crypto_aead_ivsize(aead);
70
71 if (len) {
72 len += crypto_aead_alignmask(aead) &
73 ~(crypto_tfm_ctx_alignment() - 1);
74 len = ALIGN(len, crypto_tfm_ctx_alignment());
75 }
76
77 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
78 len = ALIGN(len, __alignof__(struct scatterlist));
79
80 len += sizeof(struct scatterlist) * nfrags;
81
82 return kmalloc(len, GFP_ATOMIC);
83}
84
85static inline void *esp_tmp_extra(void *tmp)
86{
87 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
88}
89
90static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int seqhilen)
91{
92 return crypto_aead_ivsize(aead) ?
93 PTR_ALIGN((u8 *)tmp + seqhilen,
94 crypto_aead_alignmask(aead) + 1) : tmp + seqhilen;
95}
96
97static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
98{
99 struct aead_request *req;
100
101 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
102 crypto_tfm_ctx_alignment());
103 aead_request_set_tfm(req, aead);
104 return req;
105}
106
107static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
108 struct aead_request *req)
109{
110 return (void *)ALIGN((unsigned long)(req + 1) +
111 crypto_aead_reqsize(aead),
112 __alignof__(struct scatterlist));
113}
114
115static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
116{
117 struct esp_output_extra *extra = esp_tmp_extra(tmp);
118 struct crypto_aead *aead = x->data;
119 int extralen = 0;
120 u8 *iv;
121 struct aead_request *req;
122 struct scatterlist *sg;
123
124 if (x->props.flags & XFRM_STATE_ESN)
125 extralen += sizeof(*extra);
126
127 iv = esp_tmp_iv(aead, tmp, extralen);
128 req = esp_tmp_req(aead, iv);
129
130 /* Unref skb_frag_pages in the src scatterlist if necessary.
131 * Skip the first sg which comes from skb->data.
132 */
133 if (req->src != req->dst)
134 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
135 put_page(sg_page(sg));
136}
137
138#ifdef CONFIG_INET6_ESPINTCP
139struct esp_tcp_sk {
140 struct sock *sk;
141 struct rcu_head rcu;
142};
143
144static void esp_free_tcp_sk(struct rcu_head *head)
145{
146 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
147
148 sock_put(esk->sk);
149 kfree(esk);
150}
151
152static struct sock *esp6_find_tcp_sk(struct xfrm_state *x)
153{
154 struct xfrm_encap_tmpl *encap = x->encap;
155 struct esp_tcp_sk *esk;
156 __be16 sport, dport;
157 struct sock *nsk;
158 struct sock *sk;
159
160 sk = rcu_dereference(x->encap_sk);
161 if (sk && sk->sk_state == TCP_ESTABLISHED)
162 return sk;
163
164 spin_lock_bh(&x->lock);
165 sport = encap->encap_sport;
166 dport = encap->encap_dport;
167 nsk = rcu_dereference_protected(x->encap_sk,
168 lockdep_is_held(&x->lock));
169 if (sk && sk == nsk) {
170 esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
171 if (!esk) {
172 spin_unlock_bh(&x->lock);
173 return ERR_PTR(-ENOMEM);
174 }
175 RCU_INIT_POINTER(x->encap_sk, NULL);
176 esk->sk = sk;
177 call_rcu(&esk->rcu, esp_free_tcp_sk);
178 }
179 spin_unlock_bh(&x->lock);
180
181 sk = __inet6_lookup_established(xs_net(x), &tcp_hashinfo, &x->id.daddr.in6,
182 dport, &x->props.saddr.in6, ntohs(sport), 0, 0);
183 if (!sk)
184 return ERR_PTR(-ENOENT);
185
186 if (!tcp_is_ulp_esp(sk)) {
187 sock_put(sk);
188 return ERR_PTR(-EINVAL);
189 }
190
191 spin_lock_bh(&x->lock);
192 nsk = rcu_dereference_protected(x->encap_sk,
193 lockdep_is_held(&x->lock));
194 if (encap->encap_sport != sport ||
195 encap->encap_dport != dport) {
196 sock_put(sk);
197 sk = nsk ?: ERR_PTR(-EREMCHG);
198 } else if (sk == nsk) {
199 sock_put(sk);
200 } else {
201 rcu_assign_pointer(x->encap_sk, sk);
202 }
203 spin_unlock_bh(&x->lock);
204
205 return sk;
206}
207
208static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
209{
210 struct sock *sk;
211 int err;
212
213 rcu_read_lock();
214
215 sk = esp6_find_tcp_sk(x);
216 err = PTR_ERR_OR_ZERO(sk);
217 if (err)
218 goto out;
219
220 bh_lock_sock(sk);
221 if (sock_owned_by_user(sk))
222 err = espintcp_queue_out(sk, skb);
223 else
224 err = espintcp_push_skb(sk, skb);
225 bh_unlock_sock(sk);
226
227out:
228 rcu_read_unlock();
229 return err;
230}
231
232static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
233 struct sk_buff *skb)
234{
235 struct dst_entry *dst = skb_dst(skb);
236 struct xfrm_state *x = dst->xfrm;
237
238 return esp_output_tcp_finish(x, skb);
239}
240
241static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
242{
243 int err;
244
245 local_bh_disable();
246 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
247 local_bh_enable();
248
249 /* EINPROGRESS just happens to do the right thing. It
250 * actually means that the skb has been consumed and
251 * isn't coming back.
252 */
253 return err ?: -EINPROGRESS;
254}
255#else
256static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
257{
258 kfree_skb(skb);
259
260 return -EOPNOTSUPP;
261}
262#endif
263
264static void esp_output_encap_csum(struct sk_buff *skb)
265{
266 /* UDP encap with IPv6 requires a valid checksum */
267 if (*skb_mac_header(skb) == IPPROTO_UDP) {
268 struct udphdr *uh = udp_hdr(skb);
269 struct ipv6hdr *ip6h = ipv6_hdr(skb);
270 int len = ntohs(uh->len);
271 unsigned int offset = skb_transport_offset(skb);
272 __wsum csum = skb_checksum(skb, offset, skb->len - offset, 0);
273
274 uh->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
275 len, IPPROTO_UDP, csum);
276 if (uh->check == 0)
277 uh->check = CSUM_MANGLED_0;
278 }
279}
280
281static void esp_output_done(struct crypto_async_request *base, int err)
282{
283 struct sk_buff *skb = base->data;
284 struct xfrm_offload *xo = xfrm_offload(skb);
285 void *tmp;
286 struct xfrm_state *x;
287
288 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
289 struct sec_path *sp = skb_sec_path(skb);
290
291 x = sp->xvec[sp->len - 1];
292 } else {
293 x = skb_dst(skb)->xfrm;
294 }
295
296 tmp = ESP_SKB_CB(skb)->tmp;
297 esp_ssg_unref(x, tmp);
298 kfree(tmp);
299
300 esp_output_encap_csum(skb);
301
302 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
303 if (err) {
304 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
305 kfree_skb(skb);
306 return;
307 }
308
309 skb_push(skb, skb->data - skb_mac_header(skb));
310 secpath_reset(skb);
311 xfrm_dev_resume(skb);
312 } else {
313 if (!err &&
314 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
315 esp_output_tail_tcp(x, skb);
316 else
317 xfrm_output_resume(skb->sk, skb, err);
318 }
319}
320
321/* Move ESP header back into place. */
322static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
323{
324 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
325 void *tmp = ESP_SKB_CB(skb)->tmp;
326 __be32 *seqhi = esp_tmp_extra(tmp);
327
328 esph->seq_no = esph->spi;
329 esph->spi = *seqhi;
330}
331
332static void esp_output_restore_header(struct sk_buff *skb)
333{
334 void *tmp = ESP_SKB_CB(skb)->tmp;
335 struct esp_output_extra *extra = esp_tmp_extra(tmp);
336
337 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
338 sizeof(__be32));
339}
340
341static struct ip_esp_hdr *esp_output_set_esn(struct sk_buff *skb,
342 struct xfrm_state *x,
343 struct ip_esp_hdr *esph,
344 struct esp_output_extra *extra)
345{
346 /* For ESN we move the header forward by 4 bytes to
347 * accomodate the high bits. We will move it back after
348 * encryption.
349 */
350 if ((x->props.flags & XFRM_STATE_ESN)) {
351 __u32 seqhi;
352 struct xfrm_offload *xo = xfrm_offload(skb);
353
354 if (xo)
355 seqhi = xo->seq.hi;
356 else
357 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
358
359 extra->esphoff = (unsigned char *)esph -
360 skb_transport_header(skb);
361 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
362 extra->seqhi = esph->spi;
363 esph->seq_no = htonl(seqhi);
364 }
365
366 esph->spi = x->id.spi;
367
368 return esph;
369}
370
371static void esp_output_done_esn(struct crypto_async_request *base, int err)
372{
373 struct sk_buff *skb = base->data;
374
375 esp_output_restore_header(skb);
376 esp_output_done(base, err);
377}
378
379static struct ip_esp_hdr *esp6_output_udp_encap(struct sk_buff *skb,
380 int encap_type,
381 struct esp_info *esp,
382 __be16 sport,
383 __be16 dport)
384{
385 struct udphdr *uh;
386 __be32 *udpdata32;
387 unsigned int len;
388
389 len = skb->len + esp->tailen - skb_transport_offset(skb);
390 if (len > U16_MAX)
391 return ERR_PTR(-EMSGSIZE);
392
393 uh = (struct udphdr *)esp->esph;
394 uh->source = sport;
395 uh->dest = dport;
396 uh->len = htons(len);
397 uh->check = 0;
398
399 *skb_mac_header(skb) = IPPROTO_UDP;
400
401 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
402 udpdata32 = (__be32 *)(uh + 1);
403 udpdata32[0] = udpdata32[1] = 0;
404 return (struct ip_esp_hdr *)(udpdata32 + 2);
405 }
406
407 return (struct ip_esp_hdr *)(uh + 1);
408}
409
410#ifdef CONFIG_INET6_ESPINTCP
411static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x,
412 struct sk_buff *skb,
413 struct esp_info *esp)
414{
415 __be16 *lenp = (void *)esp->esph;
416 struct ip_esp_hdr *esph;
417 unsigned int len;
418 struct sock *sk;
419
420 len = skb->len + esp->tailen - skb_transport_offset(skb);
421 if (len > IP_MAX_MTU)
422 return ERR_PTR(-EMSGSIZE);
423
424 rcu_read_lock();
425 sk = esp6_find_tcp_sk(x);
426 rcu_read_unlock();
427
428 if (IS_ERR(sk))
429 return ERR_CAST(sk);
430
431 *lenp = htons(len);
432 esph = (struct ip_esp_hdr *)(lenp + 1);
433
434 return esph;
435}
436#else
437static struct ip_esp_hdr *esp6_output_tcp_encap(struct xfrm_state *x,
438 struct sk_buff *skb,
439 struct esp_info *esp)
440{
441 return ERR_PTR(-EOPNOTSUPP);
442}
443#endif
444
445static int esp6_output_encap(struct xfrm_state *x, struct sk_buff *skb,
446 struct esp_info *esp)
447{
448 struct xfrm_encap_tmpl *encap = x->encap;
449 struct ip_esp_hdr *esph;
450 __be16 sport, dport;
451 int encap_type;
452
453 spin_lock_bh(&x->lock);
454 sport = encap->encap_sport;
455 dport = encap->encap_dport;
456 encap_type = encap->encap_type;
457 spin_unlock_bh(&x->lock);
458
459 switch (encap_type) {
460 default:
461 case UDP_ENCAP_ESPINUDP:
462 case UDP_ENCAP_ESPINUDP_NON_IKE:
463 esph = esp6_output_udp_encap(skb, encap_type, esp, sport, dport);
464 break;
465 case TCP_ENCAP_ESPINTCP:
466 esph = esp6_output_tcp_encap(x, skb, esp);
467 break;
468 }
469
470 if (IS_ERR(esph))
471 return PTR_ERR(esph);
472
473 esp->esph = esph;
474
475 return 0;
476}
477
478int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
479{
480 u8 *tail;
481 int nfrags;
482 int esph_offset;
483 struct page *page;
484 struct sk_buff *trailer;
485 int tailen = esp->tailen;
486
487 if (x->encap) {
488 int err = esp6_output_encap(x, skb, esp);
489
490 if (err < 0)
491 return err;
492 }
493
494 if (!skb_cloned(skb)) {
495 if (tailen <= skb_tailroom(skb)) {
496 nfrags = 1;
497 trailer = skb;
498 tail = skb_tail_pointer(trailer);
499
500 goto skip_cow;
501 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
502 && !skb_has_frag_list(skb)) {
503 int allocsize;
504 struct sock *sk = skb->sk;
505 struct page_frag *pfrag = &x->xfrag;
506
507 esp->inplace = false;
508
509 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
510
511 spin_lock_bh(&x->lock);
512
513 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
514 spin_unlock_bh(&x->lock);
515 goto cow;
516 }
517
518 page = pfrag->page;
519 get_page(page);
520
521 tail = page_address(page) + pfrag->offset;
522
523 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
524
525 nfrags = skb_shinfo(skb)->nr_frags;
526
527 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
528 tailen);
529 skb_shinfo(skb)->nr_frags = ++nfrags;
530
531 pfrag->offset = pfrag->offset + allocsize;
532
533 spin_unlock_bh(&x->lock);
534
535 nfrags++;
536
537 skb->len += tailen;
538 skb->data_len += tailen;
539 skb->truesize += tailen;
540 if (sk && sk_fullsock(sk))
541 refcount_add(tailen, &sk->sk_wmem_alloc);
542
543 goto out;
544 }
545 }
546
547cow:
548 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
549
550 nfrags = skb_cow_data(skb, tailen, &trailer);
551 if (nfrags < 0)
552 goto out;
553 tail = skb_tail_pointer(trailer);
554 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
555
556skip_cow:
557 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
558 pskb_put(skb, trailer, tailen);
559
560out:
561 return nfrags;
562}
563EXPORT_SYMBOL_GPL(esp6_output_head);
564
565int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
566{
567 u8 *iv;
568 int alen;
569 void *tmp;
570 int ivlen;
571 int assoclen;
572 int extralen;
573 struct page *page;
574 struct ip_esp_hdr *esph;
575 struct aead_request *req;
576 struct crypto_aead *aead;
577 struct scatterlist *sg, *dsg;
578 struct esp_output_extra *extra;
579 int err = -ENOMEM;
580
581 assoclen = sizeof(struct ip_esp_hdr);
582 extralen = 0;
583
584 if (x->props.flags & XFRM_STATE_ESN) {
585 extralen += sizeof(*extra);
586 assoclen += sizeof(__be32);
587 }
588
589 aead = x->data;
590 alen = crypto_aead_authsize(aead);
591 ivlen = crypto_aead_ivsize(aead);
592
593 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
594 if (!tmp)
595 goto error;
596
597 extra = esp_tmp_extra(tmp);
598 iv = esp_tmp_iv(aead, tmp, extralen);
599 req = esp_tmp_req(aead, iv);
600 sg = esp_req_sg(aead, req);
601
602 if (esp->inplace)
603 dsg = sg;
604 else
605 dsg = &sg[esp->nfrags];
606
607 esph = esp_output_set_esn(skb, x, esp->esph, extra);
608 esp->esph = esph;
609
610 sg_init_table(sg, esp->nfrags);
611 err = skb_to_sgvec(skb, sg,
612 (unsigned char *)esph - skb->data,
613 assoclen + ivlen + esp->clen + alen);
614 if (unlikely(err < 0))
615 goto error_free;
616
617 if (!esp->inplace) {
618 int allocsize;
619 struct page_frag *pfrag = &x->xfrag;
620
621 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
622
623 spin_lock_bh(&x->lock);
624 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
625 spin_unlock_bh(&x->lock);
626 goto error_free;
627 }
628
629 skb_shinfo(skb)->nr_frags = 1;
630
631 page = pfrag->page;
632 get_page(page);
633 /* replace page frags in skb with new page */
634 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
635 pfrag->offset = pfrag->offset + allocsize;
636 spin_unlock_bh(&x->lock);
637
638 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
639 err = skb_to_sgvec(skb, dsg,
640 (unsigned char *)esph - skb->data,
641 assoclen + ivlen + esp->clen + alen);
642 if (unlikely(err < 0))
643 goto error_free;
644 }
645
646 if ((x->props.flags & XFRM_STATE_ESN))
647 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
648 else
649 aead_request_set_callback(req, 0, esp_output_done, skb);
650
651 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
652 aead_request_set_ad(req, assoclen);
653
654 memset(iv, 0, ivlen);
655 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
656 min(ivlen, 8));
657
658 ESP_SKB_CB(skb)->tmp = tmp;
659 err = crypto_aead_encrypt(req);
660
661 switch (err) {
662 case -EINPROGRESS:
663 goto error;
664
665 case -ENOSPC:
666 err = NET_XMIT_DROP;
667 break;
668
669 case 0:
670 if ((x->props.flags & XFRM_STATE_ESN))
671 esp_output_restore_header(skb);
672 esp_output_encap_csum(skb);
673 }
674
675 if (sg != dsg)
676 esp_ssg_unref(x, tmp);
677
678 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
679 err = esp_output_tail_tcp(x, skb);
680
681error_free:
682 kfree(tmp);
683error:
684 return err;
685}
686EXPORT_SYMBOL_GPL(esp6_output_tail);
687
688static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
689{
690 int alen;
691 int blksize;
692 struct ip_esp_hdr *esph;
693 struct crypto_aead *aead;
694 struct esp_info esp;
695
696 esp.inplace = true;
697
698 esp.proto = *skb_mac_header(skb);
699 *skb_mac_header(skb) = IPPROTO_ESP;
700
701 /* skb is pure payload to encrypt */
702
703 aead = x->data;
704 alen = crypto_aead_authsize(aead);
705
706 esp.tfclen = 0;
707 if (x->tfcpad) {
708 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
709 u32 padto;
710
711 padto = min(x->tfcpad, __xfrm_state_mtu(x, dst->child_mtu_cached));
712 if (skb->len < padto)
713 esp.tfclen = padto - skb->len;
714 }
715 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
716 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
717 esp.plen = esp.clen - skb->len - esp.tfclen;
718 esp.tailen = esp.tfclen + esp.plen + alen;
719
720 esp.esph = ip_esp_hdr(skb);
721
722 esp.nfrags = esp6_output_head(x, skb, &esp);
723 if (esp.nfrags < 0)
724 return esp.nfrags;
725
726 esph = esp.esph;
727 esph->spi = x->id.spi;
728
729 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
730 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
731 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
732
733 skb_push(skb, -skb_network_offset(skb));
734
735 return esp6_output_tail(x, skb, &esp);
736}
737
738static inline int esp_remove_trailer(struct sk_buff *skb)
739{
740 struct xfrm_state *x = xfrm_input_state(skb);
741 struct xfrm_offload *xo = xfrm_offload(skb);
742 struct crypto_aead *aead = x->data;
743 int alen, hlen, elen;
744 int padlen, trimlen;
745 __wsum csumdiff;
746 u8 nexthdr[2];
747 int ret;
748
749 alen = crypto_aead_authsize(aead);
750 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
751 elen = skb->len - hlen;
752
753 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
754 ret = xo->proto;
755 goto out;
756 }
757
758 ret = skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2);
759 BUG_ON(ret);
760
761 ret = -EINVAL;
762 padlen = nexthdr[0];
763 if (padlen + 2 + alen >= elen) {
764 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
765 padlen + 2, elen - alen);
766 goto out;
767 }
768
769 trimlen = alen + padlen + 2;
770 if (skb->ip_summed == CHECKSUM_COMPLETE) {
771 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
772 skb->csum = csum_block_sub(skb->csum, csumdiff,
773 skb->len - trimlen);
774 }
775 pskb_trim(skb, skb->len - trimlen);
776
777 ret = nexthdr[1];
778
779out:
780 return ret;
781}
782
783int esp6_input_done2(struct sk_buff *skb, int err)
784{
785 struct xfrm_state *x = xfrm_input_state(skb);
786 struct xfrm_offload *xo = xfrm_offload(skb);
787 struct crypto_aead *aead = x->data;
788 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
789 int hdr_len = skb_network_header_len(skb);
790
791 if (!xo || !(xo->flags & CRYPTO_DONE))
792 kfree(ESP_SKB_CB(skb)->tmp);
793
794 if (unlikely(err))
795 goto out;
796
797 err = esp_remove_trailer(skb);
798 if (unlikely(err < 0))
799 goto out;
800
801 if (x->encap) {
802 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
803 int offset = skb_network_offset(skb) + sizeof(*ip6h);
804 struct xfrm_encap_tmpl *encap = x->encap;
805 u8 nexthdr = ip6h->nexthdr;
806 __be16 frag_off, source;
807 struct udphdr *uh;
808 struct tcphdr *th;
809
810 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
811 uh = (void *)(skb->data + offset);
812 th = (void *)(skb->data + offset);
813 hdr_len += offset;
814
815 switch (x->encap->encap_type) {
816 case TCP_ENCAP_ESPINTCP:
817 source = th->source;
818 break;
819 case UDP_ENCAP_ESPINUDP:
820 case UDP_ENCAP_ESPINUDP_NON_IKE:
821 source = uh->source;
822 break;
823 default:
824 WARN_ON_ONCE(1);
825 err = -EINVAL;
826 goto out;
827 }
828
829 /*
830 * 1) if the NAT-T peer's IP or port changed then
831 * advertize the change to the keying daemon.
832 * This is an inbound SA, so just compare
833 * SRC ports.
834 */
835 if (!ipv6_addr_equal(&ip6h->saddr, &x->props.saddr.in6) ||
836 source != encap->encap_sport) {
837 xfrm_address_t ipaddr;
838
839 memcpy(&ipaddr.a6, &ip6h->saddr.s6_addr, sizeof(ipaddr.a6));
840 km_new_mapping(x, &ipaddr, source);
841
842 /* XXX: perhaps add an extra
843 * policy check here, to see
844 * if we should allow or
845 * reject a packet from a
846 * different source
847 * address/port.
848 */
849 }
850
851 /*
852 * 2) ignore UDP/TCP checksums in case
853 * of NAT-T in Transport Mode, or
854 * perform other post-processing fixes
855 * as per draft-ietf-ipsec-udp-encaps-06,
856 * section 3.1.2
857 */
858 if (x->props.mode == XFRM_MODE_TRANSPORT)
859 skb->ip_summed = CHECKSUM_UNNECESSARY;
860 }
861
862 skb_postpull_rcsum(skb, skb_network_header(skb),
863 skb_network_header_len(skb));
864 skb_pull_rcsum(skb, hlen);
865 if (x->props.mode == XFRM_MODE_TUNNEL)
866 skb_reset_transport_header(skb);
867 else
868 skb_set_transport_header(skb, -hdr_len);
869
870 /* RFC4303: Drop dummy packets without any error */
871 if (err == IPPROTO_NONE)
872 err = -EINVAL;
873
874out:
875 return err;
876}
877EXPORT_SYMBOL_GPL(esp6_input_done2);
878
879static void esp_input_done(struct crypto_async_request *base, int err)
880{
881 struct sk_buff *skb = base->data;
882
883 xfrm_input_resume(skb, esp6_input_done2(skb, err));
884}
885
886static void esp_input_restore_header(struct sk_buff *skb)
887{
888 esp_restore_header(skb, 0);
889 __skb_pull(skb, 4);
890}
891
892static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
893{
894 struct xfrm_state *x = xfrm_input_state(skb);
895
896 /* For ESN we move the header forward by 4 bytes to
897 * accomodate the high bits. We will move it back after
898 * decryption.
899 */
900 if ((x->props.flags & XFRM_STATE_ESN)) {
901 struct ip_esp_hdr *esph = skb_push(skb, 4);
902
903 *seqhi = esph->spi;
904 esph->spi = esph->seq_no;
905 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
906 }
907}
908
909static void esp_input_done_esn(struct crypto_async_request *base, int err)
910{
911 struct sk_buff *skb = base->data;
912
913 esp_input_restore_header(skb);
914 esp_input_done(base, err);
915}
916
917static int esp6_input(struct xfrm_state *x, struct sk_buff *skb)
918{
919 struct crypto_aead *aead = x->data;
920 struct aead_request *req;
921 struct sk_buff *trailer;
922 int ivlen = crypto_aead_ivsize(aead);
923 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
924 int nfrags;
925 int assoclen;
926 int seqhilen;
927 int ret = 0;
928 void *tmp;
929 __be32 *seqhi;
930 u8 *iv;
931 struct scatterlist *sg;
932
933 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen)) {
934 ret = -EINVAL;
935 goto out;
936 }
937
938 if (elen <= 0) {
939 ret = -EINVAL;
940 goto out;
941 }
942
943 assoclen = sizeof(struct ip_esp_hdr);
944 seqhilen = 0;
945
946 if (x->props.flags & XFRM_STATE_ESN) {
947 seqhilen += sizeof(__be32);
948 assoclen += seqhilen;
949 }
950
951 if (!skb_cloned(skb)) {
952 if (!skb_is_nonlinear(skb)) {
953 nfrags = 1;
954
955 goto skip_cow;
956 } else if (!skb_has_frag_list(skb)) {
957 nfrags = skb_shinfo(skb)->nr_frags;
958 nfrags++;
959
960 goto skip_cow;
961 }
962 }
963
964 nfrags = skb_cow_data(skb, 0, &trailer);
965 if (nfrags < 0) {
966 ret = -EINVAL;
967 goto out;
968 }
969
970skip_cow:
971 ret = -ENOMEM;
972 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
973 if (!tmp)
974 goto out;
975
976 ESP_SKB_CB(skb)->tmp = tmp;
977 seqhi = esp_tmp_extra(tmp);
978 iv = esp_tmp_iv(aead, tmp, seqhilen);
979 req = esp_tmp_req(aead, iv);
980 sg = esp_req_sg(aead, req);
981
982 esp_input_set_header(skb, seqhi);
983
984 sg_init_table(sg, nfrags);
985 ret = skb_to_sgvec(skb, sg, 0, skb->len);
986 if (unlikely(ret < 0)) {
987 kfree(tmp);
988 goto out;
989 }
990
991 skb->ip_summed = CHECKSUM_NONE;
992
993 if ((x->props.flags & XFRM_STATE_ESN))
994 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
995 else
996 aead_request_set_callback(req, 0, esp_input_done, skb);
997
998 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
999 aead_request_set_ad(req, assoclen);
1000
1001 ret = crypto_aead_decrypt(req);
1002 if (ret == -EINPROGRESS)
1003 goto out;
1004
1005 if ((x->props.flags & XFRM_STATE_ESN))
1006 esp_input_restore_header(skb);
1007
1008 ret = esp6_input_done2(skb, ret);
1009
1010out:
1011 return ret;
1012}
1013
1014static int esp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
1015 u8 type, u8 code, int offset, __be32 info)
1016{
1017 struct net *net = dev_net(skb->dev);
1018 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data;
1019 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data + offset);
1020 struct xfrm_state *x;
1021
1022 if (type != ICMPV6_PKT_TOOBIG &&
1023 type != NDISC_REDIRECT)
1024 return 0;
1025
1026 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
1027 esph->spi, IPPROTO_ESP, AF_INET6);
1028 if (!x)
1029 return 0;
1030
1031 if (type == NDISC_REDIRECT)
1032 ip6_redirect(skb, net, skb->dev->ifindex, 0,
1033 sock_net_uid(net, NULL));
1034 else
1035 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL));
1036 xfrm_state_put(x);
1037
1038 return 0;
1039}
1040
1041static void esp6_destroy(struct xfrm_state *x)
1042{
1043 struct crypto_aead *aead = x->data;
1044
1045 if (!aead)
1046 return;
1047
1048 crypto_free_aead(aead);
1049}
1050
1051static int esp_init_aead(struct xfrm_state *x)
1052{
1053 char aead_name[CRYPTO_MAX_ALG_NAME];
1054 struct crypto_aead *aead;
1055 int err;
1056
1057 err = -ENAMETOOLONG;
1058 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1059 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
1060 goto error;
1061
1062 aead = crypto_alloc_aead(aead_name, 0, 0);
1063 err = PTR_ERR(aead);
1064 if (IS_ERR(aead))
1065 goto error;
1066
1067 x->data = aead;
1068
1069 err = crypto_aead_setkey(aead, x->aead->alg_key,
1070 (x->aead->alg_key_len + 7) / 8);
1071 if (err)
1072 goto error;
1073
1074 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
1075 if (err)
1076 goto error;
1077
1078error:
1079 return err;
1080}
1081
1082static int esp_init_authenc(struct xfrm_state *x)
1083{
1084 struct crypto_aead *aead;
1085 struct crypto_authenc_key_param *param;
1086 struct rtattr *rta;
1087 char *key;
1088 char *p;
1089 char authenc_name[CRYPTO_MAX_ALG_NAME];
1090 unsigned int keylen;
1091 int err;
1092
1093 err = -EINVAL;
1094 if (!x->ealg)
1095 goto error;
1096
1097 err = -ENAMETOOLONG;
1098
1099 if ((x->props.flags & XFRM_STATE_ESN)) {
1100 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1101 "%s%sauthencesn(%s,%s)%s",
1102 x->geniv ?: "", x->geniv ? "(" : "",
1103 x->aalg ? x->aalg->alg_name : "digest_null",
1104 x->ealg->alg_name,
1105 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1106 goto error;
1107 } else {
1108 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1109 "%s%sauthenc(%s,%s)%s",
1110 x->geniv ?: "", x->geniv ? "(" : "",
1111 x->aalg ? x->aalg->alg_name : "digest_null",
1112 x->ealg->alg_name,
1113 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1114 goto error;
1115 }
1116
1117 aead = crypto_alloc_aead(authenc_name, 0, 0);
1118 err = PTR_ERR(aead);
1119 if (IS_ERR(aead))
1120 goto error;
1121
1122 x->data = aead;
1123
1124 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
1125 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
1126 err = -ENOMEM;
1127 key = kmalloc(keylen, GFP_KERNEL);
1128 if (!key)
1129 goto error;
1130
1131 p = key;
1132 rta = (void *)p;
1133 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1134 rta->rta_len = RTA_LENGTH(sizeof(*param));
1135 param = RTA_DATA(rta);
1136 p += RTA_SPACE(sizeof(*param));
1137
1138 if (x->aalg) {
1139 struct xfrm_algo_desc *aalg_desc;
1140
1141 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1142 p += (x->aalg->alg_key_len + 7) / 8;
1143
1144 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1145 BUG_ON(!aalg_desc);
1146
1147 err = -EINVAL;
1148 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1149 crypto_aead_authsize(aead)) {
1150 pr_info("ESP: %s digestsize %u != %u\n",
1151 x->aalg->alg_name,
1152 crypto_aead_authsize(aead),
1153 aalg_desc->uinfo.auth.icv_fullbits / 8);
1154 goto free_key;
1155 }
1156
1157 err = crypto_aead_setauthsize(
1158 aead, x->aalg->alg_trunc_len / 8);
1159 if (err)
1160 goto free_key;
1161 }
1162
1163 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1164 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1165
1166 err = crypto_aead_setkey(aead, key, keylen);
1167
1168free_key:
1169 kfree(key);
1170
1171error:
1172 return err;
1173}
1174
1175static int esp6_init_state(struct xfrm_state *x)
1176{
1177 struct crypto_aead *aead;
1178 u32 align;
1179 int err;
1180
1181 x->data = NULL;
1182
1183 if (x->aead)
1184 err = esp_init_aead(x);
1185 else
1186 err = esp_init_authenc(x);
1187
1188 if (err)
1189 goto error;
1190
1191 aead = x->data;
1192
1193 x->props.header_len = sizeof(struct ip_esp_hdr) +
1194 crypto_aead_ivsize(aead);
1195 switch (x->props.mode) {
1196 case XFRM_MODE_BEET:
1197 if (x->sel.family != AF_INET6)
1198 x->props.header_len += IPV4_BEET_PHMAXLEN +
1199 (sizeof(struct ipv6hdr) - sizeof(struct iphdr));
1200 break;
1201 default:
1202 case XFRM_MODE_TRANSPORT:
1203 break;
1204 case XFRM_MODE_TUNNEL:
1205 x->props.header_len += sizeof(struct ipv6hdr);
1206 break;
1207 }
1208
1209 if (x->encap) {
1210 struct xfrm_encap_tmpl *encap = x->encap;
1211
1212 switch (encap->encap_type) {
1213 default:
1214 err = -EINVAL;
1215 goto error;
1216 case UDP_ENCAP_ESPINUDP:
1217 x->props.header_len += sizeof(struct udphdr);
1218 break;
1219 case UDP_ENCAP_ESPINUDP_NON_IKE:
1220 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1221 break;
1222#ifdef CONFIG_INET6_ESPINTCP
1223 case TCP_ENCAP_ESPINTCP:
1224 /* only the length field, TCP encap is done by
1225 * the socket
1226 */
1227 x->props.header_len += 2;
1228 break;
1229#endif
1230 }
1231 }
1232
1233 align = ALIGN(crypto_aead_blocksize(aead), 4);
1234 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1235
1236error:
1237 return err;
1238}
1239
1240static int esp6_rcv_cb(struct sk_buff *skb, int err)
1241{
1242 return 0;
1243}
1244
1245static const struct xfrm_type esp6_type = {
1246 .owner = THIS_MODULE,
1247 .proto = IPPROTO_ESP,
1248 .flags = XFRM_TYPE_REPLAY_PROT,
1249 .init_state = esp6_init_state,
1250 .destructor = esp6_destroy,
1251 .input = esp6_input,
1252 .output = esp6_output,
1253};
1254
1255static struct xfrm6_protocol esp6_protocol = {
1256 .handler = xfrm6_rcv,
1257 .input_handler = xfrm_input,
1258 .cb_handler = esp6_rcv_cb,
1259 .err_handler = esp6_err,
1260 .priority = 0,
1261};
1262
1263static int __init esp6_init(void)
1264{
1265 if (xfrm_register_type(&esp6_type, AF_INET6) < 0) {
1266 pr_info("%s: can't add xfrm type\n", __func__);
1267 return -EAGAIN;
1268 }
1269 if (xfrm6_protocol_register(&esp6_protocol, IPPROTO_ESP) < 0) {
1270 pr_info("%s: can't add protocol\n", __func__);
1271 xfrm_unregister_type(&esp6_type, AF_INET6);
1272 return -EAGAIN;
1273 }
1274
1275 return 0;
1276}
1277
1278static void __exit esp6_fini(void)
1279{
1280 if (xfrm6_protocol_deregister(&esp6_protocol, IPPROTO_ESP) < 0)
1281 pr_info("%s: can't remove protocol\n", __func__);
1282 xfrm_unregister_type(&esp6_type, AF_INET6);
1283}
1284
1285module_init(esp6_init);
1286module_exit(esp6_fini);
1287
1288MODULE_LICENSE("GPL");
1289MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ESP);
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);