1
2#define pr_fmt(fmt) "IPsec: " fmt
3
4#include <crypto/aead.h>
5#include <crypto/authenc.h>
6#include <linux/err.h>
7#include <linux/module.h>
8#include <net/ip.h>
9#include <net/xfrm.h>
10#include <net/esp.h>
11#include <linux/scatterlist.h>
12#include <linux/kernel.h>
13#include <linux/pfkeyv2.h>
14#include <linux/rtnetlink.h>
15#include <linux/slab.h>
16#include <linux/spinlock.h>
17#include <linux/in6.h>
18#include <net/icmp.h>
19#include <net/protocol.h>
20#include <net/udp.h>
21#include <net/tcp.h>
22#include <net/espintcp.h>
23
24#include <linux/highmem.h>
25
26struct esp_skb_cb {
27 struct xfrm_skb_cb xfrm;
28 void *tmp;
29};
30
31struct esp_output_extra {
32 __be32 seqhi;
33 u32 esphoff;
34};
35
36#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
37
38
39
40
41
42
43
44
45
46static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
47{
48 unsigned int len;
49
50 len = extralen;
51
52 len += crypto_aead_ivsize(aead);
53
54 if (len) {
55 len += crypto_aead_alignmask(aead) &
56 ~(crypto_tfm_ctx_alignment() - 1);
57 len = ALIGN(len, crypto_tfm_ctx_alignment());
58 }
59
60 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
61 len = ALIGN(len, __alignof__(struct scatterlist));
62
63 len += sizeof(struct scatterlist) * nfrags;
64
65 return kmalloc(len, GFP_ATOMIC);
66}
67
68static inline void *esp_tmp_extra(void *tmp)
69{
70 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
71}
72
73static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
74{
75 return crypto_aead_ivsize(aead) ?
76 PTR_ALIGN((u8 *)tmp + extralen,
77 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
78}
79
80static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
81{
82 struct aead_request *req;
83
84 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
85 crypto_tfm_ctx_alignment());
86 aead_request_set_tfm(req, aead);
87 return req;
88}
89
90static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
91 struct aead_request *req)
92{
93 return (void *)ALIGN((unsigned long)(req + 1) +
94 crypto_aead_reqsize(aead),
95 __alignof__(struct scatterlist));
96}
97
98static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
99{
100 struct crypto_aead *aead = x->data;
101 int extralen = 0;
102 u8 *iv;
103 struct aead_request *req;
104 struct scatterlist *sg;
105
106 if (x->props.flags & XFRM_STATE_ESN)
107 extralen += sizeof(struct esp_output_extra);
108
109 iv = esp_tmp_iv(aead, tmp, extralen);
110 req = esp_tmp_req(aead, iv);
111
112
113
114
115 if (req->src != req->dst)
116 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
117 put_page(sg_page(sg));
118}
119
120#ifdef CONFIG_INET_ESPINTCP
121struct esp_tcp_sk {
122 struct sock *sk;
123 struct rcu_head rcu;
124};
125
126static void esp_free_tcp_sk(struct rcu_head *head)
127{
128 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
129
130 sock_put(esk->sk);
131 kfree(esk);
132}
133
134static struct sock *esp_find_tcp_sk(struct xfrm_state *x)
135{
136 struct xfrm_encap_tmpl *encap = x->encap;
137 struct esp_tcp_sk *esk;
138 __be16 sport, dport;
139 struct sock *nsk;
140 struct sock *sk;
141
142 sk = rcu_dereference(x->encap_sk);
143 if (sk && sk->sk_state == TCP_ESTABLISHED)
144 return sk;
145
146 spin_lock_bh(&x->lock);
147 sport = encap->encap_sport;
148 dport = encap->encap_dport;
149 nsk = rcu_dereference_protected(x->encap_sk,
150 lockdep_is_held(&x->lock));
151 if (sk && sk == nsk) {
152 esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
153 if (!esk) {
154 spin_unlock_bh(&x->lock);
155 return ERR_PTR(-ENOMEM);
156 }
157 RCU_INIT_POINTER(x->encap_sk, NULL);
158 esk->sk = sk;
159 call_rcu(&esk->rcu, esp_free_tcp_sk);
160 }
161 spin_unlock_bh(&x->lock);
162
163 sk = inet_lookup_established(xs_net(x), &tcp_hashinfo, x->id.daddr.a4,
164 dport, x->props.saddr.a4, sport, 0);
165 if (!sk)
166 return ERR_PTR(-ENOENT);
167
168 if (!tcp_is_ulp_esp(sk)) {
169 sock_put(sk);
170 return ERR_PTR(-EINVAL);
171 }
172
173 spin_lock_bh(&x->lock);
174 nsk = rcu_dereference_protected(x->encap_sk,
175 lockdep_is_held(&x->lock));
176 if (encap->encap_sport != sport ||
177 encap->encap_dport != dport) {
178 sock_put(sk);
179 sk = nsk ?: ERR_PTR(-EREMCHG);
180 } else if (sk == nsk) {
181 sock_put(sk);
182 } else {
183 rcu_assign_pointer(x->encap_sk, sk);
184 }
185 spin_unlock_bh(&x->lock);
186
187 return sk;
188}
189
190static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
191{
192 struct sock *sk;
193 int err;
194
195 rcu_read_lock();
196
197 sk = esp_find_tcp_sk(x);
198 err = PTR_ERR_OR_ZERO(sk);
199 if (err)
200 goto out;
201
202 bh_lock_sock(sk);
203 if (sock_owned_by_user(sk))
204 err = espintcp_queue_out(sk, skb);
205 else
206 err = espintcp_push_skb(sk, skb);
207 bh_unlock_sock(sk);
208
209out:
210 rcu_read_unlock();
211 return err;
212}
213
214static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
215 struct sk_buff *skb)
216{
217 struct dst_entry *dst = skb_dst(skb);
218 struct xfrm_state *x = dst->xfrm;
219
220 return esp_output_tcp_finish(x, skb);
221}
222
223static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
224{
225 int err;
226
227 local_bh_disable();
228 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
229 local_bh_enable();
230
231
232
233
234
235 return err ?: -EINPROGRESS;
236}
237#else
238static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
239{
240 kfree_skb(skb);
241
242 return -EOPNOTSUPP;
243}
244#endif
245
246static void esp_output_done(struct crypto_async_request *base, int err)
247{
248 struct sk_buff *skb = base->data;
249 struct xfrm_offload *xo = xfrm_offload(skb);
250 void *tmp;
251 struct xfrm_state *x;
252
253 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
254 struct sec_path *sp = skb_sec_path(skb);
255
256 x = sp->xvec[sp->len - 1];
257 } else {
258 x = skb_dst(skb)->xfrm;
259 }
260
261 tmp = ESP_SKB_CB(skb)->tmp;
262 esp_ssg_unref(x, tmp);
263 kfree(tmp);
264
265 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
266 if (err) {
267 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
268 kfree_skb(skb);
269 return;
270 }
271
272 skb_push(skb, skb->data - skb_mac_header(skb));
273 secpath_reset(skb);
274 xfrm_dev_resume(skb);
275 } else {
276 if (!err &&
277 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
278 esp_output_tail_tcp(x, skb);
279 else
280 xfrm_output_resume(skb->sk, skb, err);
281 }
282}
283
284
285static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
286{
287 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
288 void *tmp = ESP_SKB_CB(skb)->tmp;
289 __be32 *seqhi = esp_tmp_extra(tmp);
290
291 esph->seq_no = esph->spi;
292 esph->spi = *seqhi;
293}
294
295static void esp_output_restore_header(struct sk_buff *skb)
296{
297 void *tmp = ESP_SKB_CB(skb)->tmp;
298 struct esp_output_extra *extra = esp_tmp_extra(tmp);
299
300 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
301 sizeof(__be32));
302}
303
304static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
305 struct xfrm_state *x,
306 struct ip_esp_hdr *esph,
307 struct esp_output_extra *extra)
308{
309
310
311
312
313 if ((x->props.flags & XFRM_STATE_ESN)) {
314 __u32 seqhi;
315 struct xfrm_offload *xo = xfrm_offload(skb);
316
317 if (xo)
318 seqhi = xo->seq.hi;
319 else
320 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
321
322 extra->esphoff = (unsigned char *)esph -
323 skb_transport_header(skb);
324 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
325 extra->seqhi = esph->spi;
326 esph->seq_no = htonl(seqhi);
327 }
328
329 esph->spi = x->id.spi;
330
331 return esph;
332}
333
334static void esp_output_done_esn(struct crypto_async_request *base, int err)
335{
336 struct sk_buff *skb = base->data;
337
338 esp_output_restore_header(skb);
339 esp_output_done(base, err);
340}
341
342static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
343 int encap_type,
344 struct esp_info *esp,
345 __be16 sport,
346 __be16 dport)
347{
348 struct udphdr *uh;
349 __be32 *udpdata32;
350 unsigned int len;
351
352 len = skb->len + esp->tailen - skb_transport_offset(skb);
353 if (len + sizeof(struct iphdr) > IP_MAX_MTU)
354 return ERR_PTR(-EMSGSIZE);
355
356 uh = (struct udphdr *)esp->esph;
357 uh->source = sport;
358 uh->dest = dport;
359 uh->len = htons(len);
360 uh->check = 0;
361
362 *skb_mac_header(skb) = IPPROTO_UDP;
363
364 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
365 udpdata32 = (__be32 *)(uh + 1);
366 udpdata32[0] = udpdata32[1] = 0;
367 return (struct ip_esp_hdr *)(udpdata32 + 2);
368 }
369
370 return (struct ip_esp_hdr *)(uh + 1);
371}
372
373#ifdef CONFIG_INET_ESPINTCP
374static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
375 struct sk_buff *skb,
376 struct esp_info *esp)
377{
378 __be16 *lenp = (void *)esp->esph;
379 struct ip_esp_hdr *esph;
380 unsigned int len;
381 struct sock *sk;
382
383 len = skb->len + esp->tailen - skb_transport_offset(skb);
384 if (len > IP_MAX_MTU)
385 return ERR_PTR(-EMSGSIZE);
386
387 rcu_read_lock();
388 sk = esp_find_tcp_sk(x);
389 rcu_read_unlock();
390
391 if (IS_ERR(sk))
392 return ERR_CAST(sk);
393
394 *lenp = htons(len);
395 esph = (struct ip_esp_hdr *)(lenp + 1);
396
397 return esph;
398}
399#else
400static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
401 struct sk_buff *skb,
402 struct esp_info *esp)
403{
404 return ERR_PTR(-EOPNOTSUPP);
405}
406#endif
407
408static int esp_output_encap(struct xfrm_state *x, struct sk_buff *skb,
409 struct esp_info *esp)
410{
411 struct xfrm_encap_tmpl *encap = x->encap;
412 struct ip_esp_hdr *esph;
413 __be16 sport, dport;
414 int encap_type;
415
416 spin_lock_bh(&x->lock);
417 sport = encap->encap_sport;
418 dport = encap->encap_dport;
419 encap_type = encap->encap_type;
420 spin_unlock_bh(&x->lock);
421
422 switch (encap_type) {
423 default:
424 case UDP_ENCAP_ESPINUDP:
425 case UDP_ENCAP_ESPINUDP_NON_IKE:
426 esph = esp_output_udp_encap(skb, encap_type, esp, sport, dport);
427 break;
428 case TCP_ENCAP_ESPINTCP:
429 esph = esp_output_tcp_encap(x, skb, esp);
430 break;
431 }
432
433 if (IS_ERR(esph))
434 return PTR_ERR(esph);
435
436 esp->esph = esph;
437
438 return 0;
439}
440
441int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
442{
443 u8 *tail;
444 int nfrags;
445 int esph_offset;
446 struct page *page;
447 struct sk_buff *trailer;
448 int tailen = esp->tailen;
449
450
451 if (x->encap) {
452 int err = esp_output_encap(x, skb, esp);
453
454 if (err < 0)
455 return err;
456 }
457
458 if (!skb_cloned(skb)) {
459 if (tailen <= skb_tailroom(skb)) {
460 nfrags = 1;
461 trailer = skb;
462 tail = skb_tail_pointer(trailer);
463
464 goto skip_cow;
465 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
466 && !skb_has_frag_list(skb)) {
467 int allocsize;
468 struct sock *sk = skb->sk;
469 struct page_frag *pfrag = &x->xfrag;
470
471 esp->inplace = false;
472
473 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
474
475 spin_lock_bh(&x->lock);
476
477 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
478 spin_unlock_bh(&x->lock);
479 goto cow;
480 }
481
482 page = pfrag->page;
483 get_page(page);
484
485 tail = page_address(page) + pfrag->offset;
486
487 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
488
489 nfrags = skb_shinfo(skb)->nr_frags;
490
491 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
492 tailen);
493 skb_shinfo(skb)->nr_frags = ++nfrags;
494
495 pfrag->offset = pfrag->offset + allocsize;
496
497 spin_unlock_bh(&x->lock);
498
499 nfrags++;
500
501 skb->len += tailen;
502 skb->data_len += tailen;
503 skb->truesize += tailen;
504 if (sk && sk_fullsock(sk))
505 refcount_add(tailen, &sk->sk_wmem_alloc);
506
507 goto out;
508 }
509 }
510
511cow:
512 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
513
514 nfrags = skb_cow_data(skb, tailen, &trailer);
515 if (nfrags < 0)
516 goto out;
517 tail = skb_tail_pointer(trailer);
518 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
519
520skip_cow:
521 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
522 pskb_put(skb, trailer, tailen);
523
524out:
525 return nfrags;
526}
527EXPORT_SYMBOL_GPL(esp_output_head);
528
529int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
530{
531 u8 *iv;
532 int alen;
533 void *tmp;
534 int ivlen;
535 int assoclen;
536 int extralen;
537 struct page *page;
538 struct ip_esp_hdr *esph;
539 struct crypto_aead *aead;
540 struct aead_request *req;
541 struct scatterlist *sg, *dsg;
542 struct esp_output_extra *extra;
543 int err = -ENOMEM;
544
545 assoclen = sizeof(struct ip_esp_hdr);
546 extralen = 0;
547
548 if (x->props.flags & XFRM_STATE_ESN) {
549 extralen += sizeof(*extra);
550 assoclen += sizeof(__be32);
551 }
552
553 aead = x->data;
554 alen = crypto_aead_authsize(aead);
555 ivlen = crypto_aead_ivsize(aead);
556
557 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
558 if (!tmp)
559 goto error;
560
561 extra = esp_tmp_extra(tmp);
562 iv = esp_tmp_iv(aead, tmp, extralen);
563 req = esp_tmp_req(aead, iv);
564 sg = esp_req_sg(aead, req);
565
566 if (esp->inplace)
567 dsg = sg;
568 else
569 dsg = &sg[esp->nfrags];
570
571 esph = esp_output_set_extra(skb, x, esp->esph, extra);
572 esp->esph = esph;
573
574 sg_init_table(sg, esp->nfrags);
575 err = skb_to_sgvec(skb, sg,
576 (unsigned char *)esph - skb->data,
577 assoclen + ivlen + esp->clen + alen);
578 if (unlikely(err < 0))
579 goto error_free;
580
581 if (!esp->inplace) {
582 int allocsize;
583 struct page_frag *pfrag = &x->xfrag;
584
585 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
586
587 spin_lock_bh(&x->lock);
588 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
589 spin_unlock_bh(&x->lock);
590 goto error_free;
591 }
592
593 skb_shinfo(skb)->nr_frags = 1;
594
595 page = pfrag->page;
596 get_page(page);
597
598 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
599 pfrag->offset = pfrag->offset + allocsize;
600 spin_unlock_bh(&x->lock);
601
602 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
603 err = skb_to_sgvec(skb, dsg,
604 (unsigned char *)esph - skb->data,
605 assoclen + ivlen + esp->clen + alen);
606 if (unlikely(err < 0))
607 goto error_free;
608 }
609
610 if ((x->props.flags & XFRM_STATE_ESN))
611 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
612 else
613 aead_request_set_callback(req, 0, esp_output_done, skb);
614
615 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
616 aead_request_set_ad(req, assoclen);
617
618 memset(iv, 0, ivlen);
619 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
620 min(ivlen, 8));
621
622 ESP_SKB_CB(skb)->tmp = tmp;
623 err = crypto_aead_encrypt(req);
624
625 switch (err) {
626 case -EINPROGRESS:
627 goto error;
628
629 case -ENOSPC:
630 err = NET_XMIT_DROP;
631 break;
632
633 case 0:
634 if ((x->props.flags & XFRM_STATE_ESN))
635 esp_output_restore_header(skb);
636 }
637
638 if (sg != dsg)
639 esp_ssg_unref(x, tmp);
640
641 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
642 err = esp_output_tail_tcp(x, skb);
643
644error_free:
645 kfree(tmp);
646error:
647 return err;
648}
649EXPORT_SYMBOL_GPL(esp_output_tail);
650
651static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
652{
653 int alen;
654 int blksize;
655 struct ip_esp_hdr *esph;
656 struct crypto_aead *aead;
657 struct esp_info esp;
658
659 esp.inplace = true;
660
661 esp.proto = *skb_mac_header(skb);
662 *skb_mac_header(skb) = IPPROTO_ESP;
663
664
665
666 aead = x->data;
667 alen = crypto_aead_authsize(aead);
668
669 esp.tfclen = 0;
670 if (x->tfcpad) {
671 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
672 u32 padto;
673
674 padto = min(x->tfcpad, __xfrm_state_mtu(x, dst->child_mtu_cached));
675 if (skb->len < padto)
676 esp.tfclen = padto - skb->len;
677 }
678 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
679 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
680 esp.plen = esp.clen - skb->len - esp.tfclen;
681 esp.tailen = esp.tfclen + esp.plen + alen;
682
683 esp.esph = ip_esp_hdr(skb);
684
685 esp.nfrags = esp_output_head(x, skb, &esp);
686 if (esp.nfrags < 0)
687 return esp.nfrags;
688
689 esph = esp.esph;
690 esph->spi = x->id.spi;
691
692 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
693 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
694 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
695
696 skb_push(skb, -skb_network_offset(skb));
697
698 return esp_output_tail(x, skb, &esp);
699}
700
701static inline int esp_remove_trailer(struct sk_buff *skb)
702{
703 struct xfrm_state *x = xfrm_input_state(skb);
704 struct xfrm_offload *xo = xfrm_offload(skb);
705 struct crypto_aead *aead = x->data;
706 int alen, hlen, elen;
707 int padlen, trimlen;
708 __wsum csumdiff;
709 u8 nexthdr[2];
710 int ret;
711
712 alen = crypto_aead_authsize(aead);
713 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
714 elen = skb->len - hlen;
715
716 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
717 ret = xo->proto;
718 goto out;
719 }
720
721 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
722 BUG();
723
724 ret = -EINVAL;
725 padlen = nexthdr[0];
726 if (padlen + 2 + alen >= elen) {
727 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
728 padlen + 2, elen - alen);
729 goto out;
730 }
731
732 trimlen = alen + padlen + 2;
733 if (skb->ip_summed == CHECKSUM_COMPLETE) {
734 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
735 skb->csum = csum_block_sub(skb->csum, csumdiff,
736 skb->len - trimlen);
737 }
738 pskb_trim(skb, skb->len - trimlen);
739
740 ret = nexthdr[1];
741
742out:
743 return ret;
744}
745
746int esp_input_done2(struct sk_buff *skb, int err)
747{
748 const struct iphdr *iph;
749 struct xfrm_state *x = xfrm_input_state(skb);
750 struct xfrm_offload *xo = xfrm_offload(skb);
751 struct crypto_aead *aead = x->data;
752 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
753 int ihl;
754
755 if (!xo || !(xo->flags & CRYPTO_DONE))
756 kfree(ESP_SKB_CB(skb)->tmp);
757
758 if (unlikely(err))
759 goto out;
760
761 err = esp_remove_trailer(skb);
762 if (unlikely(err < 0))
763 goto out;
764
765 iph = ip_hdr(skb);
766 ihl = iph->ihl * 4;
767
768 if (x->encap) {
769 struct xfrm_encap_tmpl *encap = x->encap;
770 struct tcphdr *th = (void *)(skb_network_header(skb) + ihl);
771 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
772 __be16 source;
773
774 switch (x->encap->encap_type) {
775 case TCP_ENCAP_ESPINTCP:
776 source = th->source;
777 break;
778 case UDP_ENCAP_ESPINUDP:
779 case UDP_ENCAP_ESPINUDP_NON_IKE:
780 source = uh->source;
781 break;
782 default:
783 WARN_ON_ONCE(1);
784 err = -EINVAL;
785 goto out;
786 }
787
788
789
790
791
792
793
794 if (iph->saddr != x->props.saddr.a4 ||
795 source != encap->encap_sport) {
796 xfrm_address_t ipaddr;
797
798 ipaddr.a4 = iph->saddr;
799 km_new_mapping(x, &ipaddr, source);
800
801
802
803
804
805
806
807
808 }
809
810
811
812
813
814
815
816
817 if (x->props.mode == XFRM_MODE_TRANSPORT)
818 skb->ip_summed = CHECKSUM_UNNECESSARY;
819 }
820
821 skb_pull_rcsum(skb, hlen);
822 if (x->props.mode == XFRM_MODE_TUNNEL)
823 skb_reset_transport_header(skb);
824 else
825 skb_set_transport_header(skb, -ihl);
826
827
828 if (err == IPPROTO_NONE)
829 err = -EINVAL;
830
831out:
832 return err;
833}
834EXPORT_SYMBOL_GPL(esp_input_done2);
835
836static void esp_input_done(struct crypto_async_request *base, int err)
837{
838 struct sk_buff *skb = base->data;
839
840 xfrm_input_resume(skb, esp_input_done2(skb, err));
841}
842
843static void esp_input_restore_header(struct sk_buff *skb)
844{
845 esp_restore_header(skb, 0);
846 __skb_pull(skb, 4);
847}
848
849static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
850{
851 struct xfrm_state *x = xfrm_input_state(skb);
852 struct ip_esp_hdr *esph;
853
854
855
856
857
858 if ((x->props.flags & XFRM_STATE_ESN)) {
859 esph = skb_push(skb, 4);
860 *seqhi = esph->spi;
861 esph->spi = esph->seq_no;
862 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
863 }
864}
865
866static void esp_input_done_esn(struct crypto_async_request *base, int err)
867{
868 struct sk_buff *skb = base->data;
869
870 esp_input_restore_header(skb);
871 esp_input_done(base, err);
872}
873
874
875
876
877
878
879static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
880{
881 struct crypto_aead *aead = x->data;
882 struct aead_request *req;
883 struct sk_buff *trailer;
884 int ivlen = crypto_aead_ivsize(aead);
885 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
886 int nfrags;
887 int assoclen;
888 int seqhilen;
889 __be32 *seqhi;
890 void *tmp;
891 u8 *iv;
892 struct scatterlist *sg;
893 int err = -EINVAL;
894
895 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
896 goto out;
897
898 if (elen <= 0)
899 goto out;
900
901 assoclen = sizeof(struct ip_esp_hdr);
902 seqhilen = 0;
903
904 if (x->props.flags & XFRM_STATE_ESN) {
905 seqhilen += sizeof(__be32);
906 assoclen += seqhilen;
907 }
908
909 if (!skb_cloned(skb)) {
910 if (!skb_is_nonlinear(skb)) {
911 nfrags = 1;
912
913 goto skip_cow;
914 } else if (!skb_has_frag_list(skb)) {
915 nfrags = skb_shinfo(skb)->nr_frags;
916 nfrags++;
917
918 goto skip_cow;
919 }
920 }
921
922 err = skb_cow_data(skb, 0, &trailer);
923 if (err < 0)
924 goto out;
925
926 nfrags = err;
927
928skip_cow:
929 err = -ENOMEM;
930 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
931 if (!tmp)
932 goto out;
933
934 ESP_SKB_CB(skb)->tmp = tmp;
935 seqhi = esp_tmp_extra(tmp);
936 iv = esp_tmp_iv(aead, tmp, seqhilen);
937 req = esp_tmp_req(aead, iv);
938 sg = esp_req_sg(aead, req);
939
940 esp_input_set_header(skb, seqhi);
941
942 sg_init_table(sg, nfrags);
943 err = skb_to_sgvec(skb, sg, 0, skb->len);
944 if (unlikely(err < 0)) {
945 kfree(tmp);
946 goto out;
947 }
948
949 skb->ip_summed = CHECKSUM_NONE;
950
951 if ((x->props.flags & XFRM_STATE_ESN))
952 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
953 else
954 aead_request_set_callback(req, 0, esp_input_done, skb);
955
956 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
957 aead_request_set_ad(req, assoclen);
958
959 err = crypto_aead_decrypt(req);
960 if (err == -EINPROGRESS)
961 goto out;
962
963 if ((x->props.flags & XFRM_STATE_ESN))
964 esp_input_restore_header(skb);
965
966 err = esp_input_done2(skb, err);
967
968out:
969 return err;
970}
971
972static int esp4_err(struct sk_buff *skb, u32 info)
973{
974 struct net *net = dev_net(skb->dev);
975 const struct iphdr *iph = (const struct iphdr *)skb->data;
976 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
977 struct xfrm_state *x;
978
979 switch (icmp_hdr(skb)->type) {
980 case ICMP_DEST_UNREACH:
981 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
982 return 0;
983 break;
984 case ICMP_REDIRECT:
985 break;
986 default:
987 return 0;
988 }
989
990 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
991 esph->spi, IPPROTO_ESP, AF_INET);
992 if (!x)
993 return 0;
994
995 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
996 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
997 else
998 ipv4_redirect(skb, net, 0, IPPROTO_ESP);
999 xfrm_state_put(x);
1000
1001 return 0;
1002}
1003
1004static void esp_destroy(struct xfrm_state *x)
1005{
1006 struct crypto_aead *aead = x->data;
1007
1008 if (!aead)
1009 return;
1010
1011 crypto_free_aead(aead);
1012}
1013
1014static int esp_init_aead(struct xfrm_state *x)
1015{
1016 char aead_name[CRYPTO_MAX_ALG_NAME];
1017 struct crypto_aead *aead;
1018 int err;
1019
1020 err = -ENAMETOOLONG;
1021 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1022 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
1023 goto error;
1024
1025 aead = crypto_alloc_aead(aead_name, 0, 0);
1026 err = PTR_ERR(aead);
1027 if (IS_ERR(aead))
1028 goto error;
1029
1030 x->data = aead;
1031
1032 err = crypto_aead_setkey(aead, x->aead->alg_key,
1033 (x->aead->alg_key_len + 7) / 8);
1034 if (err)
1035 goto error;
1036
1037 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
1038 if (err)
1039 goto error;
1040
1041error:
1042 return err;
1043}
1044
1045static int esp_init_authenc(struct xfrm_state *x)
1046{
1047 struct crypto_aead *aead;
1048 struct crypto_authenc_key_param *param;
1049 struct rtattr *rta;
1050 char *key;
1051 char *p;
1052 char authenc_name[CRYPTO_MAX_ALG_NAME];
1053 unsigned int keylen;
1054 int err;
1055
1056 err = -EINVAL;
1057 if (!x->ealg)
1058 goto error;
1059
1060 err = -ENAMETOOLONG;
1061
1062 if ((x->props.flags & XFRM_STATE_ESN)) {
1063 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1064 "%s%sauthencesn(%s,%s)%s",
1065 x->geniv ?: "", x->geniv ? "(" : "",
1066 x->aalg ? x->aalg->alg_name : "digest_null",
1067 x->ealg->alg_name,
1068 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1069 goto error;
1070 } else {
1071 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1072 "%s%sauthenc(%s,%s)%s",
1073 x->geniv ?: "", x->geniv ? "(" : "",
1074 x->aalg ? x->aalg->alg_name : "digest_null",
1075 x->ealg->alg_name,
1076 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1077 goto error;
1078 }
1079
1080 aead = crypto_alloc_aead(authenc_name, 0, 0);
1081 err = PTR_ERR(aead);
1082 if (IS_ERR(aead))
1083 goto error;
1084
1085 x->data = aead;
1086
1087 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
1088 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
1089 err = -ENOMEM;
1090 key = kmalloc(keylen, GFP_KERNEL);
1091 if (!key)
1092 goto error;
1093
1094 p = key;
1095 rta = (void *)p;
1096 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1097 rta->rta_len = RTA_LENGTH(sizeof(*param));
1098 param = RTA_DATA(rta);
1099 p += RTA_SPACE(sizeof(*param));
1100
1101 if (x->aalg) {
1102 struct xfrm_algo_desc *aalg_desc;
1103
1104 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1105 p += (x->aalg->alg_key_len + 7) / 8;
1106
1107 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1108 BUG_ON(!aalg_desc);
1109
1110 err = -EINVAL;
1111 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1112 crypto_aead_authsize(aead)) {
1113 pr_info("ESP: %s digestsize %u != %hu\n",
1114 x->aalg->alg_name,
1115 crypto_aead_authsize(aead),
1116 aalg_desc->uinfo.auth.icv_fullbits / 8);
1117 goto free_key;
1118 }
1119
1120 err = crypto_aead_setauthsize(
1121 aead, x->aalg->alg_trunc_len / 8);
1122 if (err)
1123 goto free_key;
1124 }
1125
1126 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1127 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1128
1129 err = crypto_aead_setkey(aead, key, keylen);
1130
1131free_key:
1132 kfree(key);
1133
1134error:
1135 return err;
1136}
1137
1138static int esp_init_state(struct xfrm_state *x)
1139{
1140 struct crypto_aead *aead;
1141 u32 align;
1142 int err;
1143
1144 x->data = NULL;
1145
1146 if (x->aead)
1147 err = esp_init_aead(x);
1148 else
1149 err = esp_init_authenc(x);
1150
1151 if (err)
1152 goto error;
1153
1154 aead = x->data;
1155
1156 x->props.header_len = sizeof(struct ip_esp_hdr) +
1157 crypto_aead_ivsize(aead);
1158 if (x->props.mode == XFRM_MODE_TUNNEL)
1159 x->props.header_len += sizeof(struct iphdr);
1160 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
1161 x->props.header_len += IPV4_BEET_PHMAXLEN;
1162 if (x->encap) {
1163 struct xfrm_encap_tmpl *encap = x->encap;
1164
1165 switch (encap->encap_type) {
1166 default:
1167 err = -EINVAL;
1168 goto error;
1169 case UDP_ENCAP_ESPINUDP:
1170 x->props.header_len += sizeof(struct udphdr);
1171 break;
1172 case UDP_ENCAP_ESPINUDP_NON_IKE:
1173 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1174 break;
1175#ifdef CONFIG_INET_ESPINTCP
1176 case TCP_ENCAP_ESPINTCP:
1177
1178
1179
1180 x->props.header_len += 2;
1181 break;
1182#endif
1183 }
1184 }
1185
1186 align = ALIGN(crypto_aead_blocksize(aead), 4);
1187 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1188
1189error:
1190 return err;
1191}
1192
1193static int esp4_rcv_cb(struct sk_buff *skb, int err)
1194{
1195 return 0;
1196}
1197
1198static const struct xfrm_type esp_type =
1199{
1200 .owner = THIS_MODULE,
1201 .proto = IPPROTO_ESP,
1202 .flags = XFRM_TYPE_REPLAY_PROT,
1203 .init_state = esp_init_state,
1204 .destructor = esp_destroy,
1205 .input = esp_input,
1206 .output = esp_output,
1207};
1208
1209static struct xfrm4_protocol esp4_protocol = {
1210 .handler = xfrm4_rcv,
1211 .input_handler = xfrm_input,
1212 .cb_handler = esp4_rcv_cb,
1213 .err_handler = esp4_err,
1214 .priority = 0,
1215};
1216
1217static int __init esp4_init(void)
1218{
1219 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
1220 pr_info("%s: can't add xfrm type\n", __func__);
1221 return -EAGAIN;
1222 }
1223 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
1224 pr_info("%s: can't add protocol\n", __func__);
1225 xfrm_unregister_type(&esp_type, AF_INET);
1226 return -EAGAIN;
1227 }
1228 return 0;
1229}
1230
1231static void __exit esp4_fini(void)
1232{
1233 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
1234 pr_info("%s: can't remove protocol\n", __func__);
1235 xfrm_unregister_type(&esp_type, AF_INET);
1236}
1237
1238module_init(esp4_init);
1239module_exit(esp4_fini);
1240MODULE_LICENSE("GPL");
1241MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
1242