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1#define pr_fmt(fmt) "IPsec: " fmt
2
3#include <crypto/aead.h>
4#include <crypto/authenc.h>
5#include <linux/err.h>
6#include <linux/module.h>
7#include <net/ip.h>
8#include <net/xfrm.h>
9#include <net/esp.h>
10#include <linux/scatterlist.h>
11#include <linux/kernel.h>
12#include <linux/pfkeyv2.h>
13#include <linux/rtnetlink.h>
14#include <linux/slab.h>
15#include <linux/spinlock.h>
16#include <linux/in6.h>
17#include <net/icmp.h>
18#include <net/protocol.h>
19#include <net/udp.h>
20
21#include <linux/highmem.h>
22
23struct esp_skb_cb {
24 struct xfrm_skb_cb xfrm;
25 void *tmp;
26};
27
28struct esp_output_extra {
29 __be32 seqhi;
30 u32 esphoff;
31};
32
33#define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
34
35static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
36
37/*
38 * Allocate an AEAD request structure with extra space for SG and IV.
39 *
40 * For alignment considerations the IV is placed at the front, followed
41 * by the request and finally the SG list.
42 *
43 * TODO: Use spare space in skb for this where possible.
44 */
45static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
46{
47 unsigned int len;
48
49 len = extralen;
50
51 len += crypto_aead_ivsize(aead);
52
53 if (len) {
54 len += crypto_aead_alignmask(aead) &
55 ~(crypto_tfm_ctx_alignment() - 1);
56 len = ALIGN(len, crypto_tfm_ctx_alignment());
57 }
58
59 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
60 len = ALIGN(len, __alignof__(struct scatterlist));
61
62 len += sizeof(struct scatterlist) * nfrags;
63
64 return kmalloc(len, GFP_ATOMIC);
65}
66
67static inline void *esp_tmp_extra(void *tmp)
68{
69 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
70}
71
72static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
73{
74 return crypto_aead_ivsize(aead) ?
75 PTR_ALIGN((u8 *)tmp + extralen,
76 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
77}
78
79static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
80{
81 struct aead_request *req;
82
83 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
84 crypto_tfm_ctx_alignment());
85 aead_request_set_tfm(req, aead);
86 return req;
87}
88
89static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
90 struct aead_request *req)
91{
92 return (void *)ALIGN((unsigned long)(req + 1) +
93 crypto_aead_reqsize(aead),
94 __alignof__(struct scatterlist));
95}
96
97static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
98{
99 struct esp_output_extra *extra = esp_tmp_extra(tmp);
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(*extra);
108
109 extra = esp_tmp_extra(tmp);
110 iv = esp_tmp_iv(aead, tmp, extralen);
111 req = esp_tmp_req(aead, iv);
112
113 /* Unref skb_frag_pages in the src scatterlist if necessary.
114 * Skip the first sg which comes from skb->data.
115 */
116 if (req->src != req->dst)
117 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
118 put_page(sg_page(sg));
119}
120
121static void esp_output_done(struct crypto_async_request *base, int err)
122{
123 struct sk_buff *skb = base->data;
124 struct xfrm_offload *xo = xfrm_offload(skb);
125 void *tmp;
126 struct xfrm_state *x;
127
128 if (xo && (xo->flags & XFRM_DEV_RESUME))
129 x = skb->sp->xvec[skb->sp->len - 1];
130 else
131 x = skb_dst(skb)->xfrm;
132
133 tmp = ESP_SKB_CB(skb)->tmp;
134 esp_ssg_unref(x, tmp);
135 kfree(tmp);
136
137 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
138 if (err) {
139 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
140 kfree_skb(skb);
141 return;
142 }
143
144 skb_push(skb, skb->data - skb_mac_header(skb));
145 secpath_reset(skb);
146 xfrm_dev_resume(skb);
147 } else {
148 xfrm_output_resume(skb, err);
149 }
150}
151
152/* Move ESP header back into place. */
153static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
154{
155 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
156 void *tmp = ESP_SKB_CB(skb)->tmp;
157 __be32 *seqhi = esp_tmp_extra(tmp);
158
159 esph->seq_no = esph->spi;
160 esph->spi = *seqhi;
161}
162
163static void esp_output_restore_header(struct sk_buff *skb)
164{
165 void *tmp = ESP_SKB_CB(skb)->tmp;
166 struct esp_output_extra *extra = esp_tmp_extra(tmp);
167
168 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
169 sizeof(__be32));
170}
171
172static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
173 struct xfrm_state *x,
174 struct ip_esp_hdr *esph,
175 struct esp_output_extra *extra)
176{
177 /* For ESN we move the header forward by 4 bytes to
178 * accomodate the high bits. We will move it back after
179 * encryption.
180 */
181 if ((x->props.flags & XFRM_STATE_ESN)) {
182 __u32 seqhi;
183 struct xfrm_offload *xo = xfrm_offload(skb);
184
185 if (xo)
186 seqhi = xo->seq.hi;
187 else
188 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
189
190 extra->esphoff = (unsigned char *)esph -
191 skb_transport_header(skb);
192 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
193 extra->seqhi = esph->spi;
194 esph->seq_no = htonl(seqhi);
195 }
196
197 esph->spi = x->id.spi;
198
199 return esph;
200}
201
202static void esp_output_done_esn(struct crypto_async_request *base, int err)
203{
204 struct sk_buff *skb = base->data;
205
206 esp_output_restore_header(skb);
207 esp_output_done(base, err);
208}
209
210static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
211{
212 /* Fill padding... */
213 if (tfclen) {
214 memset(tail, 0, tfclen);
215 tail += tfclen;
216 }
217 do {
218 int i;
219 for (i = 0; i < plen - 2; i++)
220 tail[i] = i + 1;
221 } while (0);
222 tail[plen - 2] = plen - 2;
223 tail[plen - 1] = proto;
224}
225
226static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
227{
228 int encap_type;
229 struct udphdr *uh;
230 __be32 *udpdata32;
231 __be16 sport, dport;
232 struct xfrm_encap_tmpl *encap = x->encap;
233 struct ip_esp_hdr *esph = esp->esph;
234
235 spin_lock_bh(&x->lock);
236 sport = encap->encap_sport;
237 dport = encap->encap_dport;
238 encap_type = encap->encap_type;
239 spin_unlock_bh(&x->lock);
240
241 uh = (struct udphdr *)esph;
242 uh->source = sport;
243 uh->dest = dport;
244 uh->len = htons(skb->len + esp->tailen
245 - skb_transport_offset(skb));
246 uh->check = 0;
247
248 switch (encap_type) {
249 default:
250 case UDP_ENCAP_ESPINUDP:
251 esph = (struct ip_esp_hdr *)(uh + 1);
252 break;
253 case UDP_ENCAP_ESPINUDP_NON_IKE:
254 udpdata32 = (__be32 *)(uh + 1);
255 udpdata32[0] = udpdata32[1] = 0;
256 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
257 break;
258 }
259
260 *skb_mac_header(skb) = IPPROTO_UDP;
261 esp->esph = esph;
262}
263
264int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
265{
266 u8 *tail;
267 u8 *vaddr;
268 int nfrags;
269 int esph_offset;
270 struct page *page;
271 struct sk_buff *trailer;
272 int tailen = esp->tailen;
273
274 /* this is non-NULL only with UDP Encapsulation */
275 if (x->encap)
276 esp_output_udp_encap(x, skb, esp);
277
278 if (!skb_cloned(skb)) {
279 if (tailen <= skb_tailroom(skb)) {
280 nfrags = 1;
281 trailer = skb;
282 tail = skb_tail_pointer(trailer);
283
284 goto skip_cow;
285 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
286 && !skb_has_frag_list(skb)) {
287 int allocsize;
288 struct sock *sk = skb->sk;
289 struct page_frag *pfrag = &x->xfrag;
290
291 esp->inplace = false;
292
293 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
294
295 spin_lock_bh(&x->lock);
296
297 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
298 spin_unlock_bh(&x->lock);
299 goto cow;
300 }
301
302 page = pfrag->page;
303 get_page(page);
304
305 vaddr = kmap_atomic(page);
306
307 tail = vaddr + pfrag->offset;
308
309 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
310
311 kunmap_atomic(vaddr);
312
313 nfrags = skb_shinfo(skb)->nr_frags;
314
315 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
316 tailen);
317 skb_shinfo(skb)->nr_frags = ++nfrags;
318
319 pfrag->offset = pfrag->offset + allocsize;
320
321 spin_unlock_bh(&x->lock);
322
323 nfrags++;
324
325 skb->len += tailen;
326 skb->data_len += tailen;
327 skb->truesize += tailen;
328 if (sk)
329 refcount_add(tailen, &sk->sk_wmem_alloc);
330
331 goto out;
332 }
333 }
334
335cow:
336 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
337
338 nfrags = skb_cow_data(skb, tailen, &trailer);
339 if (nfrags < 0)
340 goto out;
341 tail = skb_tail_pointer(trailer);
342 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
343
344skip_cow:
345 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
346 pskb_put(skb, trailer, tailen);
347
348out:
349 return nfrags;
350}
351EXPORT_SYMBOL_GPL(esp_output_head);
352
353int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
354{
355 u8 *iv;
356 int alen;
357 void *tmp;
358 int ivlen;
359 int assoclen;
360 int extralen;
361 struct page *page;
362 struct ip_esp_hdr *esph;
363 struct crypto_aead *aead;
364 struct aead_request *req;
365 struct scatterlist *sg, *dsg;
366 struct esp_output_extra *extra;
367 int err = -ENOMEM;
368
369 assoclen = sizeof(struct ip_esp_hdr);
370 extralen = 0;
371
372 if (x->props.flags & XFRM_STATE_ESN) {
373 extralen += sizeof(*extra);
374 assoclen += sizeof(__be32);
375 }
376
377 aead = x->data;
378 alen = crypto_aead_authsize(aead);
379 ivlen = crypto_aead_ivsize(aead);
380
381 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
382 if (!tmp)
383 goto error;
384
385 extra = esp_tmp_extra(tmp);
386 iv = esp_tmp_iv(aead, tmp, extralen);
387 req = esp_tmp_req(aead, iv);
388 sg = esp_req_sg(aead, req);
389
390 if (esp->inplace)
391 dsg = sg;
392 else
393 dsg = &sg[esp->nfrags];
394
395 esph = esp_output_set_extra(skb, x, esp->esph, extra);
396 esp->esph = esph;
397
398 sg_init_table(sg, esp->nfrags);
399 err = skb_to_sgvec(skb, sg,
400 (unsigned char *)esph - skb->data,
401 assoclen + ivlen + esp->clen + alen);
402 if (unlikely(err < 0))
403 goto error_free;
404
405 if (!esp->inplace) {
406 int allocsize;
407 struct page_frag *pfrag = &x->xfrag;
408
409 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
410
411 spin_lock_bh(&x->lock);
412 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
413 spin_unlock_bh(&x->lock);
414 goto error_free;
415 }
416
417 skb_shinfo(skb)->nr_frags = 1;
418
419 page = pfrag->page;
420 get_page(page);
421 /* replace page frags in skb with new page */
422 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
423 pfrag->offset = pfrag->offset + allocsize;
424 spin_unlock_bh(&x->lock);
425
426 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
427 err = skb_to_sgvec(skb, dsg,
428 (unsigned char *)esph - skb->data,
429 assoclen + ivlen + esp->clen + alen);
430 if (unlikely(err < 0))
431 goto error_free;
432 }
433
434 if ((x->props.flags & XFRM_STATE_ESN))
435 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
436 else
437 aead_request_set_callback(req, 0, esp_output_done, skb);
438
439 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
440 aead_request_set_ad(req, assoclen);
441
442 memset(iv, 0, ivlen);
443 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
444 min(ivlen, 8));
445
446 ESP_SKB_CB(skb)->tmp = tmp;
447 err = crypto_aead_encrypt(req);
448
449 switch (err) {
450 case -EINPROGRESS:
451 goto error;
452
453 case -ENOSPC:
454 err = NET_XMIT_DROP;
455 break;
456
457 case 0:
458 if ((x->props.flags & XFRM_STATE_ESN))
459 esp_output_restore_header(skb);
460 }
461
462 if (sg != dsg)
463 esp_ssg_unref(x, tmp);
464
465error_free:
466 kfree(tmp);
467error:
468 return err;
469}
470EXPORT_SYMBOL_GPL(esp_output_tail);
471
472static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
473{
474 int alen;
475 int blksize;
476 struct ip_esp_hdr *esph;
477 struct crypto_aead *aead;
478 struct esp_info esp;
479
480 esp.inplace = true;
481
482 esp.proto = *skb_mac_header(skb);
483 *skb_mac_header(skb) = IPPROTO_ESP;
484
485 /* skb is pure payload to encrypt */
486
487 aead = x->data;
488 alen = crypto_aead_authsize(aead);
489
490 esp.tfclen = 0;
491 if (x->tfcpad) {
492 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
493 u32 padto;
494
495 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
496 if (skb->len < padto)
497 esp.tfclen = padto - skb->len;
498 }
499 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
500 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
501 esp.plen = esp.clen - skb->len - esp.tfclen;
502 esp.tailen = esp.tfclen + esp.plen + alen;
503
504 esp.esph = ip_esp_hdr(skb);
505
506 esp.nfrags = esp_output_head(x, skb, &esp);
507 if (esp.nfrags < 0)
508 return esp.nfrags;
509
510 esph = esp.esph;
511 esph->spi = x->id.spi;
512
513 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
514 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
515 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
516
517 skb_push(skb, -skb_network_offset(skb));
518
519 return esp_output_tail(x, skb, &esp);
520}
521
522static inline int esp_remove_trailer(struct sk_buff *skb)
523{
524 struct xfrm_state *x = xfrm_input_state(skb);
525 struct xfrm_offload *xo = xfrm_offload(skb);
526 struct crypto_aead *aead = x->data;
527 int alen, hlen, elen;
528 int padlen, trimlen;
529 __wsum csumdiff;
530 u8 nexthdr[2];
531 int ret;
532
533 alen = crypto_aead_authsize(aead);
534 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
535 elen = skb->len - hlen;
536
537 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
538 ret = xo->proto;
539 goto out;
540 }
541
542 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
543 BUG();
544
545 ret = -EINVAL;
546 padlen = nexthdr[0];
547 if (padlen + 2 + alen >= elen) {
548 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
549 padlen + 2, elen - alen);
550 goto out;
551 }
552
553 trimlen = alen + padlen + 2;
554 if (skb->ip_summed == CHECKSUM_COMPLETE) {
555 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
556 skb->csum = csum_block_sub(skb->csum, csumdiff,
557 skb->len - trimlen);
558 }
559 pskb_trim(skb, skb->len - trimlen);
560
561 ret = nexthdr[1];
562
563out:
564 return ret;
565}
566
567int esp_input_done2(struct sk_buff *skb, int err)
568{
569 const struct iphdr *iph;
570 struct xfrm_state *x = xfrm_input_state(skb);
571 struct xfrm_offload *xo = xfrm_offload(skb);
572 struct crypto_aead *aead = x->data;
573 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
574 int ihl;
575
576 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
577 kfree(ESP_SKB_CB(skb)->tmp);
578
579 if (unlikely(err))
580 goto out;
581
582 err = esp_remove_trailer(skb);
583 if (unlikely(err < 0))
584 goto out;
585
586 iph = ip_hdr(skb);
587 ihl = iph->ihl * 4;
588
589 if (x->encap) {
590 struct xfrm_encap_tmpl *encap = x->encap;
591 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
592
593 /*
594 * 1) if the NAT-T peer's IP or port changed then
595 * advertize the change to the keying daemon.
596 * This is an inbound SA, so just compare
597 * SRC ports.
598 */
599 if (iph->saddr != x->props.saddr.a4 ||
600 uh->source != encap->encap_sport) {
601 xfrm_address_t ipaddr;
602
603 ipaddr.a4 = iph->saddr;
604 km_new_mapping(x, &ipaddr, uh->source);
605
606 /* XXX: perhaps add an extra
607 * policy check here, to see
608 * if we should allow or
609 * reject a packet from a
610 * different source
611 * address/port.
612 */
613 }
614
615 /*
616 * 2) ignore UDP/TCP checksums in case
617 * of NAT-T in Transport Mode, or
618 * perform other post-processing fixes
619 * as per draft-ietf-ipsec-udp-encaps-06,
620 * section 3.1.2
621 */
622 if (x->props.mode == XFRM_MODE_TRANSPORT)
623 skb->ip_summed = CHECKSUM_UNNECESSARY;
624 }
625
626 skb_pull_rcsum(skb, hlen);
627 if (x->props.mode == XFRM_MODE_TUNNEL)
628 skb_reset_transport_header(skb);
629 else
630 skb_set_transport_header(skb, -ihl);
631
632 /* RFC4303: Drop dummy packets without any error */
633 if (err == IPPROTO_NONE)
634 err = -EINVAL;
635
636out:
637 return err;
638}
639EXPORT_SYMBOL_GPL(esp_input_done2);
640
641static void esp_input_done(struct crypto_async_request *base, int err)
642{
643 struct sk_buff *skb = base->data;
644
645 xfrm_input_resume(skb, esp_input_done2(skb, err));
646}
647
648static void esp_input_restore_header(struct sk_buff *skb)
649{
650 esp_restore_header(skb, 0);
651 __skb_pull(skb, 4);
652}
653
654static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
655{
656 struct xfrm_state *x = xfrm_input_state(skb);
657 struct ip_esp_hdr *esph;
658
659 /* For ESN we move the header forward by 4 bytes to
660 * accomodate the high bits. We will move it back after
661 * decryption.
662 */
663 if ((x->props.flags & XFRM_STATE_ESN)) {
664 esph = skb_push(skb, 4);
665 *seqhi = esph->spi;
666 esph->spi = esph->seq_no;
667 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
668 }
669}
670
671static void esp_input_done_esn(struct crypto_async_request *base, int err)
672{
673 struct sk_buff *skb = base->data;
674
675 esp_input_restore_header(skb);
676 esp_input_done(base, err);
677}
678
679/*
680 * Note: detecting truncated vs. non-truncated authentication data is very
681 * expensive, so we only support truncated data, which is the recommended
682 * and common case.
683 */
684static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
685{
686 struct ip_esp_hdr *esph;
687 struct crypto_aead *aead = x->data;
688 struct aead_request *req;
689 struct sk_buff *trailer;
690 int ivlen = crypto_aead_ivsize(aead);
691 int elen = skb->len - sizeof(*esph) - ivlen;
692 int nfrags;
693 int assoclen;
694 int seqhilen;
695 __be32 *seqhi;
696 void *tmp;
697 u8 *iv;
698 struct scatterlist *sg;
699 int err = -EINVAL;
700
701 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
702 goto out;
703
704 if (elen <= 0)
705 goto out;
706
707 assoclen = sizeof(*esph);
708 seqhilen = 0;
709
710 if (x->props.flags & XFRM_STATE_ESN) {
711 seqhilen += sizeof(__be32);
712 assoclen += seqhilen;
713 }
714
715 if (!skb_cloned(skb)) {
716 if (!skb_is_nonlinear(skb)) {
717 nfrags = 1;
718
719 goto skip_cow;
720 } else if (!skb_has_frag_list(skb)) {
721 nfrags = skb_shinfo(skb)->nr_frags;
722 nfrags++;
723
724 goto skip_cow;
725 }
726 }
727
728 err = skb_cow_data(skb, 0, &trailer);
729 if (err < 0)
730 goto out;
731
732 nfrags = err;
733
734skip_cow:
735 err = -ENOMEM;
736 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
737 if (!tmp)
738 goto out;
739
740 ESP_SKB_CB(skb)->tmp = tmp;
741 seqhi = esp_tmp_extra(tmp);
742 iv = esp_tmp_iv(aead, tmp, seqhilen);
743 req = esp_tmp_req(aead, iv);
744 sg = esp_req_sg(aead, req);
745
746 esp_input_set_header(skb, seqhi);
747
748 sg_init_table(sg, nfrags);
749 err = skb_to_sgvec(skb, sg, 0, skb->len);
750 if (unlikely(err < 0)) {
751 kfree(tmp);
752 goto out;
753 }
754
755 skb->ip_summed = CHECKSUM_NONE;
756
757 if ((x->props.flags & XFRM_STATE_ESN))
758 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
759 else
760 aead_request_set_callback(req, 0, esp_input_done, skb);
761
762 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
763 aead_request_set_ad(req, assoclen);
764
765 err = crypto_aead_decrypt(req);
766 if (err == -EINPROGRESS)
767 goto out;
768
769 if ((x->props.flags & XFRM_STATE_ESN))
770 esp_input_restore_header(skb);
771
772 err = esp_input_done2(skb, err);
773
774out:
775 return err;
776}
777
778static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
779{
780 struct crypto_aead *aead = x->data;
781 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
782 unsigned int net_adj;
783
784 switch (x->props.mode) {
785 case XFRM_MODE_TRANSPORT:
786 case XFRM_MODE_BEET:
787 net_adj = sizeof(struct iphdr);
788 break;
789 case XFRM_MODE_TUNNEL:
790 net_adj = 0;
791 break;
792 default:
793 BUG();
794 }
795
796 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
797 net_adj) & ~(blksize - 1)) + net_adj - 2;
798}
799
800static int esp4_err(struct sk_buff *skb, u32 info)
801{
802 struct net *net = dev_net(skb->dev);
803 const struct iphdr *iph = (const struct iphdr *)skb->data;
804 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
805 struct xfrm_state *x;
806
807 switch (icmp_hdr(skb)->type) {
808 case ICMP_DEST_UNREACH:
809 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
810 return 0;
811 case ICMP_REDIRECT:
812 break;
813 default:
814 return 0;
815 }
816
817 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
818 esph->spi, IPPROTO_ESP, AF_INET);
819 if (!x)
820 return 0;
821
822 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
823 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
824 else
825 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
826 xfrm_state_put(x);
827
828 return 0;
829}
830
831static void esp_destroy(struct xfrm_state *x)
832{
833 struct crypto_aead *aead = x->data;
834
835 if (!aead)
836 return;
837
838 crypto_free_aead(aead);
839}
840
841static int esp_init_aead(struct xfrm_state *x)
842{
843 char aead_name[CRYPTO_MAX_ALG_NAME];
844 struct crypto_aead *aead;
845 int err;
846
847 err = -ENAMETOOLONG;
848 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
849 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
850 goto error;
851
852 aead = crypto_alloc_aead(aead_name, 0, 0);
853 err = PTR_ERR(aead);
854 if (IS_ERR(aead))
855 goto error;
856
857 x->data = aead;
858
859 err = crypto_aead_setkey(aead, x->aead->alg_key,
860 (x->aead->alg_key_len + 7) / 8);
861 if (err)
862 goto error;
863
864 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
865 if (err)
866 goto error;
867
868error:
869 return err;
870}
871
872static int esp_init_authenc(struct xfrm_state *x)
873{
874 struct crypto_aead *aead;
875 struct crypto_authenc_key_param *param;
876 struct rtattr *rta;
877 char *key;
878 char *p;
879 char authenc_name[CRYPTO_MAX_ALG_NAME];
880 unsigned int keylen;
881 int err;
882
883 err = -EINVAL;
884 if (!x->ealg)
885 goto error;
886
887 err = -ENAMETOOLONG;
888
889 if ((x->props.flags & XFRM_STATE_ESN)) {
890 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
891 "%s%sauthencesn(%s,%s)%s",
892 x->geniv ?: "", x->geniv ? "(" : "",
893 x->aalg ? x->aalg->alg_name : "digest_null",
894 x->ealg->alg_name,
895 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
896 goto error;
897 } else {
898 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
899 "%s%sauthenc(%s,%s)%s",
900 x->geniv ?: "", x->geniv ? "(" : "",
901 x->aalg ? x->aalg->alg_name : "digest_null",
902 x->ealg->alg_name,
903 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
904 goto error;
905 }
906
907 aead = crypto_alloc_aead(authenc_name, 0, 0);
908 err = PTR_ERR(aead);
909 if (IS_ERR(aead))
910 goto error;
911
912 x->data = aead;
913
914 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
915 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
916 err = -ENOMEM;
917 key = kmalloc(keylen, GFP_KERNEL);
918 if (!key)
919 goto error;
920
921 p = key;
922 rta = (void *)p;
923 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
924 rta->rta_len = RTA_LENGTH(sizeof(*param));
925 param = RTA_DATA(rta);
926 p += RTA_SPACE(sizeof(*param));
927
928 if (x->aalg) {
929 struct xfrm_algo_desc *aalg_desc;
930
931 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
932 p += (x->aalg->alg_key_len + 7) / 8;
933
934 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
935 BUG_ON(!aalg_desc);
936
937 err = -EINVAL;
938 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
939 crypto_aead_authsize(aead)) {
940 pr_info("ESP: %s digestsize %u != %hu\n",
941 x->aalg->alg_name,
942 crypto_aead_authsize(aead),
943 aalg_desc->uinfo.auth.icv_fullbits / 8);
944 goto free_key;
945 }
946
947 err = crypto_aead_setauthsize(
948 aead, x->aalg->alg_trunc_len / 8);
949 if (err)
950 goto free_key;
951 }
952
953 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
954 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
955
956 err = crypto_aead_setkey(aead, key, keylen);
957
958free_key:
959 kfree(key);
960
961error:
962 return err;
963}
964
965static int esp_init_state(struct xfrm_state *x)
966{
967 struct crypto_aead *aead;
968 u32 align;
969 int err;
970
971 x->data = NULL;
972
973 if (x->aead)
974 err = esp_init_aead(x);
975 else
976 err = esp_init_authenc(x);
977
978 if (err)
979 goto error;
980
981 aead = x->data;
982
983 x->props.header_len = sizeof(struct ip_esp_hdr) +
984 crypto_aead_ivsize(aead);
985 if (x->props.mode == XFRM_MODE_TUNNEL)
986 x->props.header_len += sizeof(struct iphdr);
987 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
988 x->props.header_len += IPV4_BEET_PHMAXLEN;
989 if (x->encap) {
990 struct xfrm_encap_tmpl *encap = x->encap;
991
992 switch (encap->encap_type) {
993 default:
994 err = -EINVAL;
995 goto error;
996 case UDP_ENCAP_ESPINUDP:
997 x->props.header_len += sizeof(struct udphdr);
998 break;
999 case UDP_ENCAP_ESPINUDP_NON_IKE:
1000 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1001 break;
1002 }
1003 }
1004
1005 align = ALIGN(crypto_aead_blocksize(aead), 4);
1006 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1007
1008error:
1009 return err;
1010}
1011
1012static int esp4_rcv_cb(struct sk_buff *skb, int err)
1013{
1014 return 0;
1015}
1016
1017static const struct xfrm_type esp_type =
1018{
1019 .description = "ESP4",
1020 .owner = THIS_MODULE,
1021 .proto = IPPROTO_ESP,
1022 .flags = XFRM_TYPE_REPLAY_PROT,
1023 .init_state = esp_init_state,
1024 .destructor = esp_destroy,
1025 .get_mtu = esp4_get_mtu,
1026 .input = esp_input,
1027 .output = esp_output,
1028};
1029
1030static struct xfrm4_protocol esp4_protocol = {
1031 .handler = xfrm4_rcv,
1032 .input_handler = xfrm_input,
1033 .cb_handler = esp4_rcv_cb,
1034 .err_handler = esp4_err,
1035 .priority = 0,
1036};
1037
1038static int __init esp4_init(void)
1039{
1040 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
1041 pr_info("%s: can't add xfrm type\n", __func__);
1042 return -EAGAIN;
1043 }
1044 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
1045 pr_info("%s: can't add protocol\n", __func__);
1046 xfrm_unregister_type(&esp_type, AF_INET);
1047 return -EAGAIN;
1048 }
1049 return 0;
1050}
1051
1052static void __exit esp4_fini(void)
1053{
1054 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
1055 pr_info("%s: can't remove protocol\n", __func__);
1056 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
1057 pr_info("%s: can't remove xfrm type\n", __func__);
1058}
1059
1060module_init(esp4_init);
1061module_exit(esp4_fini);
1062MODULE_LICENSE("GPL");
1063MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
1// SPDX-License-Identifier: GPL-2.0-only
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 * Allocate an AEAD request structure with extra space for SG and IV.
40 *
41 * For alignment considerations the IV is placed at the front, followed
42 * by the request and finally the SG list.
43 *
44 * TODO: Use spare space in skb for this where possible.
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, struct sk_buff *skb)
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 /* Unref skb_frag_pages in the src scatterlist if necessary.
113 * Skip the first sg which comes from skb->data.
114 */
115 if (req->src != req->dst)
116 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
117 skb_page_unref(skb, sg_page(sg), false);
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 net *net = xs_net(x);
138 struct esp_tcp_sk *esk;
139 __be16 sport, dport;
140 struct sock *nsk;
141 struct sock *sk;
142
143 sk = rcu_dereference(x->encap_sk);
144 if (sk && sk->sk_state == TCP_ESTABLISHED)
145 return sk;
146
147 spin_lock_bh(&x->lock);
148 sport = encap->encap_sport;
149 dport = encap->encap_dport;
150 nsk = rcu_dereference_protected(x->encap_sk,
151 lockdep_is_held(&x->lock));
152 if (sk && sk == nsk) {
153 esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
154 if (!esk) {
155 spin_unlock_bh(&x->lock);
156 return ERR_PTR(-ENOMEM);
157 }
158 RCU_INIT_POINTER(x->encap_sk, NULL);
159 esk->sk = sk;
160 call_rcu(&esk->rcu, esp_free_tcp_sk);
161 }
162 spin_unlock_bh(&x->lock);
163
164 sk = inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, x->id.daddr.a4,
165 dport, x->props.saddr.a4, sport, 0);
166 if (!sk)
167 return ERR_PTR(-ENOENT);
168
169 if (!tcp_is_ulp_esp(sk)) {
170 sock_put(sk);
171 return ERR_PTR(-EINVAL);
172 }
173
174 spin_lock_bh(&x->lock);
175 nsk = rcu_dereference_protected(x->encap_sk,
176 lockdep_is_held(&x->lock));
177 if (encap->encap_sport != sport ||
178 encap->encap_dport != dport) {
179 sock_put(sk);
180 sk = nsk ?: ERR_PTR(-EREMCHG);
181 } else if (sk == nsk) {
182 sock_put(sk);
183 } else {
184 rcu_assign_pointer(x->encap_sk, sk);
185 }
186 spin_unlock_bh(&x->lock);
187
188 return sk;
189}
190
191static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
192{
193 struct sock *sk;
194 int err;
195
196 rcu_read_lock();
197
198 sk = esp_find_tcp_sk(x);
199 err = PTR_ERR_OR_ZERO(sk);
200 if (err)
201 goto out;
202
203 bh_lock_sock(sk);
204 if (sock_owned_by_user(sk))
205 err = espintcp_queue_out(sk, skb);
206 else
207 err = espintcp_push_skb(sk, skb);
208 bh_unlock_sock(sk);
209
210out:
211 rcu_read_unlock();
212 return err;
213}
214
215static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
216 struct sk_buff *skb)
217{
218 struct dst_entry *dst = skb_dst(skb);
219 struct xfrm_state *x = dst->xfrm;
220
221 return esp_output_tcp_finish(x, skb);
222}
223
224static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
225{
226 int err;
227
228 local_bh_disable();
229 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
230 local_bh_enable();
231
232 /* EINPROGRESS just happens to do the right thing. It
233 * actually means that the skb has been consumed and
234 * isn't coming back.
235 */
236 return err ?: -EINPROGRESS;
237}
238#else
239static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
240{
241 kfree_skb(skb);
242
243 return -EOPNOTSUPP;
244}
245#endif
246
247static void esp_output_done(void *data, int err)
248{
249 struct sk_buff *skb = data;
250 struct xfrm_offload *xo = xfrm_offload(skb);
251 void *tmp;
252 struct xfrm_state *x;
253
254 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
255 struct sec_path *sp = skb_sec_path(skb);
256
257 x = sp->xvec[sp->len - 1];
258 } else {
259 x = skb_dst(skb)->xfrm;
260 }
261
262 tmp = ESP_SKB_CB(skb)->tmp;
263 esp_ssg_unref(x, tmp, skb);
264 kfree(tmp);
265
266 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
267 if (err) {
268 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
269 kfree_skb(skb);
270 return;
271 }
272
273 skb_push(skb, skb->data - skb_mac_header(skb));
274 secpath_reset(skb);
275 xfrm_dev_resume(skb);
276 } else {
277 if (!err &&
278 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
279 esp_output_tail_tcp(x, skb);
280 else
281 xfrm_output_resume(skb->sk, skb, err);
282 }
283}
284
285/* Move ESP header back into place. */
286static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
287{
288 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
289 void *tmp = ESP_SKB_CB(skb)->tmp;
290 __be32 *seqhi = esp_tmp_extra(tmp);
291
292 esph->seq_no = esph->spi;
293 esph->spi = *seqhi;
294}
295
296static void esp_output_restore_header(struct sk_buff *skb)
297{
298 void *tmp = ESP_SKB_CB(skb)->tmp;
299 struct esp_output_extra *extra = esp_tmp_extra(tmp);
300
301 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
302 sizeof(__be32));
303}
304
305static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
306 struct xfrm_state *x,
307 struct ip_esp_hdr *esph,
308 struct esp_output_extra *extra)
309{
310 /* For ESN we move the header forward by 4 bytes to
311 * accommodate the high bits. We will move it back after
312 * encryption.
313 */
314 if ((x->props.flags & XFRM_STATE_ESN)) {
315 __u32 seqhi;
316 struct xfrm_offload *xo = xfrm_offload(skb);
317
318 if (xo)
319 seqhi = xo->seq.hi;
320 else
321 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
322
323 extra->esphoff = (unsigned char *)esph -
324 skb_transport_header(skb);
325 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
326 extra->seqhi = esph->spi;
327 esph->seq_no = htonl(seqhi);
328 }
329
330 esph->spi = x->id.spi;
331
332 return esph;
333}
334
335static void esp_output_done_esn(void *data, int err)
336{
337 struct sk_buff *skb = data;
338
339 esp_output_restore_header(skb);
340 esp_output_done(data, err);
341}
342
343static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
344 int encap_type,
345 struct esp_info *esp,
346 __be16 sport,
347 __be16 dport)
348{
349 struct udphdr *uh;
350 __be32 *udpdata32;
351 unsigned int len;
352
353 len = skb->len + esp->tailen - skb_transport_offset(skb);
354 if (len + sizeof(struct iphdr) > IP_MAX_MTU)
355 return ERR_PTR(-EMSGSIZE);
356
357 uh = (struct udphdr *)esp->esph;
358 uh->source = sport;
359 uh->dest = dport;
360 uh->len = htons(len);
361 uh->check = 0;
362
363 *skb_mac_header(skb) = IPPROTO_UDP;
364
365 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
366 udpdata32 = (__be32 *)(uh + 1);
367 udpdata32[0] = udpdata32[1] = 0;
368 return (struct ip_esp_hdr *)(udpdata32 + 2);
369 }
370
371 return (struct ip_esp_hdr *)(uh + 1);
372}
373
374#ifdef CONFIG_INET_ESPINTCP
375static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
376 struct sk_buff *skb,
377 struct esp_info *esp)
378{
379 __be16 *lenp = (void *)esp->esph;
380 struct ip_esp_hdr *esph;
381 unsigned int len;
382 struct sock *sk;
383
384 len = skb->len + esp->tailen - skb_transport_offset(skb);
385 if (len > IP_MAX_MTU)
386 return ERR_PTR(-EMSGSIZE);
387
388 rcu_read_lock();
389 sk = esp_find_tcp_sk(x);
390 rcu_read_unlock();
391
392 if (IS_ERR(sk))
393 return ERR_CAST(sk);
394
395 *lenp = htons(len);
396 esph = (struct ip_esp_hdr *)(lenp + 1);
397
398 return esph;
399}
400#else
401static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
402 struct sk_buff *skb,
403 struct esp_info *esp)
404{
405 return ERR_PTR(-EOPNOTSUPP);
406}
407#endif
408
409static int esp_output_encap(struct xfrm_state *x, struct sk_buff *skb,
410 struct esp_info *esp)
411{
412 struct xfrm_encap_tmpl *encap = x->encap;
413 struct ip_esp_hdr *esph;
414 __be16 sport, dport;
415 int encap_type;
416
417 spin_lock_bh(&x->lock);
418 sport = encap->encap_sport;
419 dport = encap->encap_dport;
420 encap_type = encap->encap_type;
421 spin_unlock_bh(&x->lock);
422
423 switch (encap_type) {
424 default:
425 case UDP_ENCAP_ESPINUDP:
426 case UDP_ENCAP_ESPINUDP_NON_IKE:
427 esph = esp_output_udp_encap(skb, encap_type, esp, sport, dport);
428 break;
429 case TCP_ENCAP_ESPINTCP:
430 esph = esp_output_tcp_encap(x, skb, esp);
431 break;
432 }
433
434 if (IS_ERR(esph))
435 return PTR_ERR(esph);
436
437 esp->esph = esph;
438
439 return 0;
440}
441
442int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
443{
444 u8 *tail;
445 int nfrags;
446 int esph_offset;
447 struct page *page;
448 struct sk_buff *trailer;
449 int tailen = esp->tailen;
450
451 /* this is non-NULL only with TCP/UDP Encapsulation */
452 if (x->encap) {
453 int err = esp_output_encap(x, skb, esp);
454
455 if (err < 0)
456 return err;
457 }
458
459 if (ALIGN(tailen, L1_CACHE_BYTES) > PAGE_SIZE ||
460 ALIGN(skb->data_len, L1_CACHE_BYTES) > PAGE_SIZE)
461 goto cow;
462
463 if (!skb_cloned(skb)) {
464 if (tailen <= skb_tailroom(skb)) {
465 nfrags = 1;
466 trailer = skb;
467 tail = skb_tail_pointer(trailer);
468
469 goto skip_cow;
470 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
471 && !skb_has_frag_list(skb)) {
472 int allocsize;
473 struct sock *sk = skb->sk;
474 struct page_frag *pfrag = &x->xfrag;
475
476 esp->inplace = false;
477
478 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
479
480 spin_lock_bh(&x->lock);
481
482 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
483 spin_unlock_bh(&x->lock);
484 goto cow;
485 }
486
487 page = pfrag->page;
488 get_page(page);
489
490 tail = page_address(page) + pfrag->offset;
491
492 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
493
494 nfrags = skb_shinfo(skb)->nr_frags;
495
496 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
497 tailen);
498 skb_shinfo(skb)->nr_frags = ++nfrags;
499
500 pfrag->offset = pfrag->offset + allocsize;
501
502 spin_unlock_bh(&x->lock);
503
504 nfrags++;
505
506 skb_len_add(skb, tailen);
507 if (sk && sk_fullsock(sk))
508 refcount_add(tailen, &sk->sk_wmem_alloc);
509
510 goto out;
511 }
512 }
513
514cow:
515 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
516
517 nfrags = skb_cow_data(skb, tailen, &trailer);
518 if (nfrags < 0)
519 goto out;
520 tail = skb_tail_pointer(trailer);
521 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
522
523skip_cow:
524 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
525 pskb_put(skb, trailer, tailen);
526
527out:
528 return nfrags;
529}
530EXPORT_SYMBOL_GPL(esp_output_head);
531
532int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
533{
534 u8 *iv;
535 int alen;
536 void *tmp;
537 int ivlen;
538 int assoclen;
539 int extralen;
540 struct page *page;
541 struct ip_esp_hdr *esph;
542 struct crypto_aead *aead;
543 struct aead_request *req;
544 struct scatterlist *sg, *dsg;
545 struct esp_output_extra *extra;
546 int err = -ENOMEM;
547
548 assoclen = sizeof(struct ip_esp_hdr);
549 extralen = 0;
550
551 if (x->props.flags & XFRM_STATE_ESN) {
552 extralen += sizeof(*extra);
553 assoclen += sizeof(__be32);
554 }
555
556 aead = x->data;
557 alen = crypto_aead_authsize(aead);
558 ivlen = crypto_aead_ivsize(aead);
559
560 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
561 if (!tmp)
562 goto error;
563
564 extra = esp_tmp_extra(tmp);
565 iv = esp_tmp_iv(aead, tmp, extralen);
566 req = esp_tmp_req(aead, iv);
567 sg = esp_req_sg(aead, req);
568
569 if (esp->inplace)
570 dsg = sg;
571 else
572 dsg = &sg[esp->nfrags];
573
574 esph = esp_output_set_extra(skb, x, esp->esph, extra);
575 esp->esph = esph;
576
577 sg_init_table(sg, esp->nfrags);
578 err = skb_to_sgvec(skb, sg,
579 (unsigned char *)esph - skb->data,
580 assoclen + ivlen + esp->clen + alen);
581 if (unlikely(err < 0))
582 goto error_free;
583
584 if (!esp->inplace) {
585 int allocsize;
586 struct page_frag *pfrag = &x->xfrag;
587
588 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
589
590 spin_lock_bh(&x->lock);
591 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
592 spin_unlock_bh(&x->lock);
593 goto error_free;
594 }
595
596 skb_shinfo(skb)->nr_frags = 1;
597
598 page = pfrag->page;
599 get_page(page);
600 /* replace page frags in skb with new page */
601 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
602 pfrag->offset = pfrag->offset + allocsize;
603 spin_unlock_bh(&x->lock);
604
605 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
606 err = skb_to_sgvec(skb, dsg,
607 (unsigned char *)esph - skb->data,
608 assoclen + ivlen + esp->clen + alen);
609 if (unlikely(err < 0))
610 goto error_free;
611 }
612
613 if ((x->props.flags & XFRM_STATE_ESN))
614 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
615 else
616 aead_request_set_callback(req, 0, esp_output_done, skb);
617
618 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
619 aead_request_set_ad(req, assoclen);
620
621 memset(iv, 0, ivlen);
622 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
623 min(ivlen, 8));
624
625 ESP_SKB_CB(skb)->tmp = tmp;
626 err = crypto_aead_encrypt(req);
627
628 switch (err) {
629 case -EINPROGRESS:
630 goto error;
631
632 case -ENOSPC:
633 err = NET_XMIT_DROP;
634 break;
635
636 case 0:
637 if ((x->props.flags & XFRM_STATE_ESN))
638 esp_output_restore_header(skb);
639 }
640
641 if (sg != dsg)
642 esp_ssg_unref(x, tmp, skb);
643
644 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
645 err = esp_output_tail_tcp(x, skb);
646
647error_free:
648 kfree(tmp);
649error:
650 return err;
651}
652EXPORT_SYMBOL_GPL(esp_output_tail);
653
654static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
655{
656 int alen;
657 int blksize;
658 struct ip_esp_hdr *esph;
659 struct crypto_aead *aead;
660 struct esp_info esp;
661
662 esp.inplace = true;
663
664 esp.proto = *skb_mac_header(skb);
665 *skb_mac_header(skb) = IPPROTO_ESP;
666
667 /* skb is pure payload to encrypt */
668
669 aead = x->data;
670 alen = crypto_aead_authsize(aead);
671
672 esp.tfclen = 0;
673 if (x->tfcpad) {
674 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
675 u32 padto;
676
677 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
678 if (skb->len < padto)
679 esp.tfclen = padto - skb->len;
680 }
681 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
682 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
683 esp.plen = esp.clen - skb->len - esp.tfclen;
684 esp.tailen = esp.tfclen + esp.plen + alen;
685
686 esp.esph = ip_esp_hdr(skb);
687
688 esp.nfrags = esp_output_head(x, skb, &esp);
689 if (esp.nfrags < 0)
690 return esp.nfrags;
691
692 esph = esp.esph;
693 esph->spi = x->id.spi;
694
695 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
696 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
697 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
698
699 skb_push(skb, -skb_network_offset(skb));
700
701 return esp_output_tail(x, skb, &esp);
702}
703
704static inline int esp_remove_trailer(struct sk_buff *skb)
705{
706 struct xfrm_state *x = xfrm_input_state(skb);
707 struct crypto_aead *aead = x->data;
708 int alen, hlen, elen;
709 int padlen, trimlen;
710 __wsum csumdiff;
711 u8 nexthdr[2];
712 int ret;
713
714 alen = crypto_aead_authsize(aead);
715 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
716 elen = skb->len - hlen;
717
718 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
719 BUG();
720
721 ret = -EINVAL;
722 padlen = nexthdr[0];
723 if (padlen + 2 + alen >= elen) {
724 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
725 padlen + 2, elen - alen);
726 goto out;
727 }
728
729 trimlen = alen + padlen + 2;
730 if (skb->ip_summed == CHECKSUM_COMPLETE) {
731 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
732 skb->csum = csum_block_sub(skb->csum, csumdiff,
733 skb->len - trimlen);
734 }
735 ret = pskb_trim(skb, skb->len - trimlen);
736 if (unlikely(ret))
737 return ret;
738
739 ret = nexthdr[1];
740
741out:
742 return ret;
743}
744
745int esp_input_done2(struct sk_buff *skb, int err)
746{
747 const struct iphdr *iph;
748 struct xfrm_state *x = xfrm_input_state(skb);
749 struct xfrm_offload *xo = xfrm_offload(skb);
750 struct crypto_aead *aead = x->data;
751 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
752 int ihl;
753
754 if (!xo || !(xo->flags & CRYPTO_DONE))
755 kfree(ESP_SKB_CB(skb)->tmp);
756
757 if (unlikely(err))
758 goto out;
759
760 err = esp_remove_trailer(skb);
761 if (unlikely(err < 0))
762 goto out;
763
764 iph = ip_hdr(skb);
765 ihl = iph->ihl * 4;
766
767 if (x->encap) {
768 struct xfrm_encap_tmpl *encap = x->encap;
769 struct tcphdr *th = (void *)(skb_network_header(skb) + ihl);
770 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
771 __be16 source;
772
773 switch (x->encap->encap_type) {
774 case TCP_ENCAP_ESPINTCP:
775 source = th->source;
776 break;
777 case UDP_ENCAP_ESPINUDP:
778 case UDP_ENCAP_ESPINUDP_NON_IKE:
779 source = uh->source;
780 break;
781 default:
782 WARN_ON_ONCE(1);
783 err = -EINVAL;
784 goto out;
785 }
786
787 /*
788 * 1) if the NAT-T peer's IP or port changed then
789 * advertise the change to the keying daemon.
790 * This is an inbound SA, so just compare
791 * SRC ports.
792 */
793 if (iph->saddr != x->props.saddr.a4 ||
794 source != encap->encap_sport) {
795 xfrm_address_t ipaddr;
796
797 ipaddr.a4 = iph->saddr;
798 km_new_mapping(x, &ipaddr, source);
799
800 /* XXX: perhaps add an extra
801 * policy check here, to see
802 * if we should allow or
803 * reject a packet from a
804 * different source
805 * address/port.
806 */
807 }
808
809 /*
810 * 2) ignore UDP/TCP checksums in case
811 * of NAT-T in Transport Mode, or
812 * perform other post-processing fixes
813 * as per draft-ietf-ipsec-udp-encaps-06,
814 * section 3.1.2
815 */
816 if (x->props.mode == XFRM_MODE_TRANSPORT)
817 skb->ip_summed = CHECKSUM_UNNECESSARY;
818 }
819
820 skb_pull_rcsum(skb, hlen);
821 if (x->props.mode == XFRM_MODE_TUNNEL)
822 skb_reset_transport_header(skb);
823 else
824 skb_set_transport_header(skb, -ihl);
825
826 /* RFC4303: Drop dummy packets without any error */
827 if (err == IPPROTO_NONE)
828 err = -EINVAL;
829
830out:
831 return err;
832}
833EXPORT_SYMBOL_GPL(esp_input_done2);
834
835static void esp_input_done(void *data, int err)
836{
837 struct sk_buff *skb = data;
838
839 xfrm_input_resume(skb, esp_input_done2(skb, err));
840}
841
842static void esp_input_restore_header(struct sk_buff *skb)
843{
844 esp_restore_header(skb, 0);
845 __skb_pull(skb, 4);
846}
847
848static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
849{
850 struct xfrm_state *x = xfrm_input_state(skb);
851 struct ip_esp_hdr *esph;
852
853 /* For ESN we move the header forward by 4 bytes to
854 * accommodate the high bits. We will move it back after
855 * decryption.
856 */
857 if ((x->props.flags & XFRM_STATE_ESN)) {
858 esph = skb_push(skb, 4);
859 *seqhi = esph->spi;
860 esph->spi = esph->seq_no;
861 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
862 }
863}
864
865static void esp_input_done_esn(void *data, int err)
866{
867 struct sk_buff *skb = data;
868
869 esp_input_restore_header(skb);
870 esp_input_done(data, err);
871}
872
873/*
874 * Note: detecting truncated vs. non-truncated authentication data is very
875 * expensive, so we only support truncated data, which is the recommended
876 * and common case.
877 */
878static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
879{
880 struct crypto_aead *aead = x->data;
881 struct aead_request *req;
882 struct sk_buff *trailer;
883 int ivlen = crypto_aead_ivsize(aead);
884 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
885 int nfrags;
886 int assoclen;
887 int seqhilen;
888 __be32 *seqhi;
889 void *tmp;
890 u8 *iv;
891 struct scatterlist *sg;
892 int err = -EINVAL;
893
894 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
895 goto out;
896
897 if (elen <= 0)
898 goto out;
899
900 assoclen = sizeof(struct ip_esp_hdr);
901 seqhilen = 0;
902
903 if (x->props.flags & XFRM_STATE_ESN) {
904 seqhilen += sizeof(__be32);
905 assoclen += seqhilen;
906 }
907
908 if (!skb_cloned(skb)) {
909 if (!skb_is_nonlinear(skb)) {
910 nfrags = 1;
911
912 goto skip_cow;
913 } else if (!skb_has_frag_list(skb)) {
914 nfrags = skb_shinfo(skb)->nr_frags;
915 nfrags++;
916
917 goto skip_cow;
918 }
919 }
920
921 err = skb_cow_data(skb, 0, &trailer);
922 if (err < 0)
923 goto out;
924
925 nfrags = err;
926
927skip_cow:
928 err = -ENOMEM;
929 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
930 if (!tmp)
931 goto out;
932
933 ESP_SKB_CB(skb)->tmp = tmp;
934 seqhi = esp_tmp_extra(tmp);
935 iv = esp_tmp_iv(aead, tmp, seqhilen);
936 req = esp_tmp_req(aead, iv);
937 sg = esp_req_sg(aead, req);
938
939 esp_input_set_header(skb, seqhi);
940
941 sg_init_table(sg, nfrags);
942 err = skb_to_sgvec(skb, sg, 0, skb->len);
943 if (unlikely(err < 0)) {
944 kfree(tmp);
945 goto out;
946 }
947
948 skb->ip_summed = CHECKSUM_NONE;
949
950 if ((x->props.flags & XFRM_STATE_ESN))
951 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
952 else
953 aead_request_set_callback(req, 0, esp_input_done, skb);
954
955 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
956 aead_request_set_ad(req, assoclen);
957
958 err = crypto_aead_decrypt(req);
959 if (err == -EINPROGRESS)
960 goto out;
961
962 if ((x->props.flags & XFRM_STATE_ESN))
963 esp_input_restore_header(skb);
964
965 err = esp_input_done2(skb, err);
966
967out:
968 return err;
969}
970
971static int esp4_err(struct sk_buff *skb, u32 info)
972{
973 struct net *net = dev_net(skb->dev);
974 const struct iphdr *iph = (const struct iphdr *)skb->data;
975 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
976 struct xfrm_state *x;
977
978 switch (icmp_hdr(skb)->type) {
979 case ICMP_DEST_UNREACH:
980 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
981 return 0;
982 break;
983 case ICMP_REDIRECT:
984 break;
985 default:
986 return 0;
987 }
988
989 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
990 esph->spi, IPPROTO_ESP, AF_INET);
991 if (!x)
992 return 0;
993
994 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
995 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
996 else
997 ipv4_redirect(skb, net, 0, IPPROTO_ESP);
998 xfrm_state_put(x);
999
1000 return 0;
1001}
1002
1003static void esp_destroy(struct xfrm_state *x)
1004{
1005 struct crypto_aead *aead = x->data;
1006
1007 if (!aead)
1008 return;
1009
1010 crypto_free_aead(aead);
1011}
1012
1013static int esp_init_aead(struct xfrm_state *x, struct netlink_ext_ack *extack)
1014{
1015 char aead_name[CRYPTO_MAX_ALG_NAME];
1016 struct crypto_aead *aead;
1017 int err;
1018
1019 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1020 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME) {
1021 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1022 return -ENAMETOOLONG;
1023 }
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
1041 return 0;
1042
1043error:
1044 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1045 return err;
1046}
1047
1048static int esp_init_authenc(struct xfrm_state *x,
1049 struct netlink_ext_ack *extack)
1050{
1051 struct crypto_aead *aead;
1052 struct crypto_authenc_key_param *param;
1053 struct rtattr *rta;
1054 char *key;
1055 char *p;
1056 char authenc_name[CRYPTO_MAX_ALG_NAME];
1057 unsigned int keylen;
1058 int err;
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 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1070 goto error;
1071 }
1072 } else {
1073 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1074 "%s%sauthenc(%s,%s)%s",
1075 x->geniv ?: "", x->geniv ? "(" : "",
1076 x->aalg ? x->aalg->alg_name : "digest_null",
1077 x->ealg->alg_name,
1078 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME) {
1079 NL_SET_ERR_MSG(extack, "Algorithm name is too long");
1080 goto error;
1081 }
1082 }
1083
1084 aead = crypto_alloc_aead(authenc_name, 0, 0);
1085 err = PTR_ERR(aead);
1086 if (IS_ERR(aead)) {
1087 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1088 goto error;
1089 }
1090
1091 x->data = aead;
1092
1093 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
1094 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
1095 err = -ENOMEM;
1096 key = kmalloc(keylen, GFP_KERNEL);
1097 if (!key)
1098 goto error;
1099
1100 p = key;
1101 rta = (void *)p;
1102 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1103 rta->rta_len = RTA_LENGTH(sizeof(*param));
1104 param = RTA_DATA(rta);
1105 p += RTA_SPACE(sizeof(*param));
1106
1107 if (x->aalg) {
1108 struct xfrm_algo_desc *aalg_desc;
1109
1110 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1111 p += (x->aalg->alg_key_len + 7) / 8;
1112
1113 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1114 BUG_ON(!aalg_desc);
1115
1116 err = -EINVAL;
1117 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1118 crypto_aead_authsize(aead)) {
1119 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1120 goto free_key;
1121 }
1122
1123 err = crypto_aead_setauthsize(
1124 aead, x->aalg->alg_trunc_len / 8);
1125 if (err) {
1126 NL_SET_ERR_MSG(extack, "Kernel was unable to initialize cryptographic operations");
1127 goto free_key;
1128 }
1129 }
1130
1131 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1132 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1133
1134 err = crypto_aead_setkey(aead, key, keylen);
1135
1136free_key:
1137 kfree_sensitive(key);
1138
1139error:
1140 return err;
1141}
1142
1143static int esp_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
1144{
1145 struct crypto_aead *aead;
1146 u32 align;
1147 int err;
1148
1149 x->data = NULL;
1150
1151 if (x->aead) {
1152 err = esp_init_aead(x, extack);
1153 } else if (x->ealg) {
1154 err = esp_init_authenc(x, extack);
1155 } else {
1156 NL_SET_ERR_MSG(extack, "ESP: AEAD or CRYPT must be provided");
1157 err = -EINVAL;
1158 }
1159
1160 if (err)
1161 goto error;
1162
1163 aead = x->data;
1164
1165 x->props.header_len = sizeof(struct ip_esp_hdr) +
1166 crypto_aead_ivsize(aead);
1167 if (x->props.mode == XFRM_MODE_TUNNEL)
1168 x->props.header_len += sizeof(struct iphdr);
1169 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
1170 x->props.header_len += IPV4_BEET_PHMAXLEN;
1171 if (x->encap) {
1172 struct xfrm_encap_tmpl *encap = x->encap;
1173
1174 switch (encap->encap_type) {
1175 default:
1176 NL_SET_ERR_MSG(extack, "Unsupported encapsulation type for ESP");
1177 err = -EINVAL;
1178 goto error;
1179 case UDP_ENCAP_ESPINUDP:
1180 x->props.header_len += sizeof(struct udphdr);
1181 break;
1182 case UDP_ENCAP_ESPINUDP_NON_IKE:
1183 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1184 break;
1185#ifdef CONFIG_INET_ESPINTCP
1186 case TCP_ENCAP_ESPINTCP:
1187 /* only the length field, TCP encap is done by
1188 * the socket
1189 */
1190 x->props.header_len += 2;
1191 break;
1192#endif
1193 }
1194 }
1195
1196 align = ALIGN(crypto_aead_blocksize(aead), 4);
1197 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1198
1199error:
1200 return err;
1201}
1202
1203static int esp4_rcv_cb(struct sk_buff *skb, int err)
1204{
1205 return 0;
1206}
1207
1208static const struct xfrm_type esp_type =
1209{
1210 .owner = THIS_MODULE,
1211 .proto = IPPROTO_ESP,
1212 .flags = XFRM_TYPE_REPLAY_PROT,
1213 .init_state = esp_init_state,
1214 .destructor = esp_destroy,
1215 .input = esp_input,
1216 .output = esp_output,
1217};
1218
1219static struct xfrm4_protocol esp4_protocol = {
1220 .handler = xfrm4_rcv,
1221 .input_handler = xfrm_input,
1222 .cb_handler = esp4_rcv_cb,
1223 .err_handler = esp4_err,
1224 .priority = 0,
1225};
1226
1227static int __init esp4_init(void)
1228{
1229 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
1230 pr_info("%s: can't add xfrm type\n", __func__);
1231 return -EAGAIN;
1232 }
1233 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
1234 pr_info("%s: can't add protocol\n", __func__);
1235 xfrm_unregister_type(&esp_type, AF_INET);
1236 return -EAGAIN;
1237 }
1238 return 0;
1239}
1240
1241static void __exit esp4_fini(void)
1242{
1243 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
1244 pr_info("%s: can't remove protocol\n", __func__);
1245 xfrm_unregister_type(&esp_type, AF_INET);
1246}
1247
1248module_init(esp4_init);
1249module_exit(esp4_fini);
1250MODULE_DESCRIPTION("IPv4 ESP transformation library");
1251MODULE_LICENSE("GPL");
1252MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);