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decnet: always not take dst->__refcnt when inserting dst into hash table
[linux/fpc-iii.git] / net / ipv4 / esp4.c
blobb1e24446e2972444835dd85c02434f3b089ba552
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
23 struct esp_skb_cb {
24 struct xfrm_skb_cb xfrm;
25 void *tmp;
26 };
27
28 struct 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
35 static 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 */
45 static 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
67 static inline void *esp_tmp_extra(void *tmp)
68 {
69 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
70 }
71
72 static 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
79 static 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
89 static 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
97 static 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
121 static void esp_output_done(struct crypto_async_request *base, int err)
122 {
123 struct sk_buff *skb = base->data;
124 void *tmp;
125 struct dst_entry *dst = skb_dst(skb);
126 struct xfrm_state *x = dst->xfrm;
127
128 tmp = ESP_SKB_CB(skb)->tmp;
129 esp_ssg_unref(x, tmp);
130 kfree(tmp);
131 xfrm_output_resume(skb, err);
132 }
133
134 /* Move ESP header back into place. */
135 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
136 {
137 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
138 void *tmp = ESP_SKB_CB(skb)->tmp;
139 __be32 *seqhi = esp_tmp_extra(tmp);
140
141 esph->seq_no = esph->spi;
142 esph->spi = *seqhi;
143 }
144
145 static void esp_output_restore_header(struct sk_buff *skb)
146 {
147 void *tmp = ESP_SKB_CB(skb)->tmp;
148 struct esp_output_extra *extra = esp_tmp_extra(tmp);
149
150 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
151 sizeof(__be32));
152 }
153
154 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
155 struct ip_esp_hdr *esph,
156 struct esp_output_extra *extra)
157 {
158 struct xfrm_state *x = skb_dst(skb)->xfrm;
159
160 /* For ESN we move the header forward by 4 bytes to
161 * accomodate the high bits. We will move it back after
162 * encryption.
163 */
164 if ((x->props.flags & XFRM_STATE_ESN)) {
165 extra->esphoff = (unsigned char *)esph -
166 skb_transport_header(skb);
167 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
168 extra->seqhi = esph->spi;
169 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
170 }
171
172 esph->spi = x->id.spi;
173
174 return esph;
175 }
176
177 static void esp_output_done_esn(struct crypto_async_request *base, int err)
178 {
179 struct sk_buff *skb = base->data;
180
181 esp_output_restore_header(skb);
182 esp_output_done(base, err);
183 }
184
185 static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
186 {
187 /* Fill padding... */
188 if (tfclen) {
189 memset(tail, 0, tfclen);
190 tail += tfclen;
191 }
192 do {
193 int i;
194 for (i = 0; i < plen - 2; i++)
195 tail[i] = i + 1;
196 } while (0);
197 tail[plen - 2] = plen - 2;
198 tail[plen - 1] = proto;
199 }
200
201 static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
202 {
203 struct esp_output_extra *extra;
204 int err = -ENOMEM;
205 struct ip_esp_hdr *esph;
206 struct crypto_aead *aead;
207 struct aead_request *req;
208 struct scatterlist *sg, *dsg;
209 struct sk_buff *trailer;
210 struct page *page;
211 void *tmp;
212 u8 *iv;
213 u8 *tail;
214 u8 *vaddr;
215 int blksize;
216 int clen;
217 int alen;
218 int plen;
219 int ivlen;
220 int tfclen;
221 int nfrags;
222 int assoclen;
223 int extralen;
224 int tailen;
225 __be64 seqno;
226 __u8 proto = *skb_mac_header(skb);
227
228 /* skb is pure payload to encrypt */
229
230 aead = x->data;
231 alen = crypto_aead_authsize(aead);
232 ivlen = crypto_aead_ivsize(aead);
233
234 tfclen = 0;
235 if (x->tfcpad) {
236 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
237 u32 padto;
238
239 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
240 if (skb->len < padto)
241 tfclen = padto - skb->len;
242 }
243 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
244 clen = ALIGN(skb->len + 2 + tfclen, blksize);
245 plen = clen - skb->len - tfclen;
246 tailen = tfclen + plen + alen;
247 assoclen = sizeof(*esph);
248 extralen = 0;
249
250 if (x->props.flags & XFRM_STATE_ESN) {
251 extralen += sizeof(*extra);
252 assoclen += sizeof(__be32);
253 }
254
255 *skb_mac_header(skb) = IPPROTO_ESP;
256 esph = ip_esp_hdr(skb);
257
258 /* this is non-NULL only with UDP Encapsulation */
259 if (x->encap) {
260 struct xfrm_encap_tmpl *encap = x->encap;
261 struct udphdr *uh;
262 __be32 *udpdata32;
263 __be16 sport, dport;
264 int encap_type;
265
266 spin_lock_bh(&x->lock);
267 sport = encap->encap_sport;
268 dport = encap->encap_dport;
269 encap_type = encap->encap_type;
270 spin_unlock_bh(&x->lock);
271
272 uh = (struct udphdr *)esph;
273 uh->source = sport;
274 uh->dest = dport;
275 uh->len = htons(skb->len + tailen
276 - skb_transport_offset(skb));
277 uh->check = 0;
278
279 switch (encap_type) {
280 default:
281 case UDP_ENCAP_ESPINUDP:
282 esph = (struct ip_esp_hdr *)(uh + 1);
283 break;
284 case UDP_ENCAP_ESPINUDP_NON_IKE:
285 udpdata32 = (__be32 *)(uh + 1);
286 udpdata32[0] = udpdata32[1] = 0;
287 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
288 break;
289 }
290
291 *skb_mac_header(skb) = IPPROTO_UDP;
292 }
293
294 if (!skb_cloned(skb)) {
295 if (tailen <= skb_availroom(skb)) {
296 nfrags = 1;
297 trailer = skb;
298 tail = skb_tail_pointer(trailer);
299
300 goto skip_cow;
301 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
302 && !skb_has_frag_list(skb)) {
303 int allocsize;
304 struct sock *sk = skb->sk;
305 struct page_frag *pfrag = &x->xfrag;
306
307 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
308
309 spin_lock_bh(&x->lock);
310
311 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
312 spin_unlock_bh(&x->lock);
313 goto cow;
314 }
315
316 page = pfrag->page;
317 get_page(page);
318
319 vaddr = kmap_atomic(page);
320
321 tail = vaddr + pfrag->offset;
322
323 esp_output_fill_trailer(tail, tfclen, plen, proto);
324
325 kunmap_atomic(vaddr);
326
327 nfrags = skb_shinfo(skb)->nr_frags;
328
329 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
330 tailen);
331 skb_shinfo(skb)->nr_frags = ++nfrags;
332
333 pfrag->offset = pfrag->offset + allocsize;
334 nfrags++;
335
336 skb->len += tailen;
337 skb->data_len += tailen;
338 skb->truesize += tailen;
339 if (sk)
340 atomic_add(tailen, &sk->sk_wmem_alloc);
341
342 skb_push(skb, -skb_network_offset(skb));
343
344 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
345 esph->spi = x->id.spi;
346
347 tmp = esp_alloc_tmp(aead, nfrags + 2, extralen);
348 if (!tmp) {
349 spin_unlock_bh(&x->lock);
350 err = -ENOMEM;
351 goto error;
352 }
353
354 extra = esp_tmp_extra(tmp);
355 iv = esp_tmp_iv(aead, tmp, extralen);
356 req = esp_tmp_req(aead, iv);
357 sg = esp_req_sg(aead, req);
358 dsg = &sg[nfrags];
359
360 esph = esp_output_set_extra(skb, esph, extra);
361
362 sg_init_table(sg, nfrags);
363 skb_to_sgvec(skb, sg,
364 (unsigned char *)esph - skb->data,
365 assoclen + ivlen + clen + alen);
366
367 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
368
369 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
370 spin_unlock_bh(&x->lock);
371 err = -ENOMEM;
372 goto error;
373 }
374
375 skb_shinfo(skb)->nr_frags = 1;
376
377 page = pfrag->page;
378 get_page(page);
379 /* replace page frags in skb with new page */
380 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
381 pfrag->offset = pfrag->offset + allocsize;
382
383 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
384 skb_to_sgvec(skb, dsg,
385 (unsigned char *)esph - skb->data,
386 assoclen + ivlen + clen + alen);
387
388 spin_unlock_bh(&x->lock);
389
390 goto skip_cow2;
391 }
392 }
393
394 cow:
395 err = skb_cow_data(skb, tailen, &trailer);
396 if (err < 0)
397 goto error;
398 nfrags = err;
399 tail = skb_tail_pointer(trailer);
400 esph = ip_esp_hdr(skb);
401
402 skip_cow:
403 esp_output_fill_trailer(tail, tfclen, plen, proto);
404
405 pskb_put(skb, trailer, clen - skb->len + alen);
406 skb_push(skb, -skb_network_offset(skb));
407 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
408 esph->spi = x->id.spi;
409
410 tmp = esp_alloc_tmp(aead, nfrags, extralen);
411 if (!tmp) {
412 err = -ENOMEM;
413 goto error;
414 }
415
416 extra = esp_tmp_extra(tmp);
417 iv = esp_tmp_iv(aead, tmp, extralen);
418 req = esp_tmp_req(aead, iv);
419 sg = esp_req_sg(aead, req);
420 dsg = sg;
421
422 esph = esp_output_set_extra(skb, esph, extra);
423
424 sg_init_table(sg, nfrags);
425 skb_to_sgvec(skb, sg,
426 (unsigned char *)esph - skb->data,
427 assoclen + ivlen + clen + alen);
428
429 skip_cow2:
430 if ((x->props.flags & XFRM_STATE_ESN))
431 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
432 else
433 aead_request_set_callback(req, 0, esp_output_done, skb);
434
435 aead_request_set_crypt(req, sg, dsg, ivlen + clen, iv);
436 aead_request_set_ad(req, assoclen);
437
438 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
439 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
440
441 memset(iv, 0, ivlen);
442 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
443 min(ivlen, 8));
444
445 ESP_SKB_CB(skb)->tmp = tmp;
446 err = crypto_aead_encrypt(req);
447
448 switch (err) {
449 case -EINPROGRESS:
450 goto error;
451
452 case -EBUSY:
453 err = NET_XMIT_DROP;
454 break;
455
456 case 0:
457 if ((x->props.flags & XFRM_STATE_ESN))
458 esp_output_restore_header(skb);
459 }
460
461 if (sg != dsg)
462 esp_ssg_unref(x, tmp);
463 kfree(tmp);
464
465 error:
466 return err;
467 }
468
469 static int esp_input_done2(struct sk_buff *skb, int err)
470 {
471 const struct iphdr *iph;
472 struct xfrm_state *x = xfrm_input_state(skb);
473 struct crypto_aead *aead = x->data;
474 int alen = crypto_aead_authsize(aead);
475 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
476 int elen = skb->len - hlen;
477 int ihl;
478 u8 nexthdr[2];
479 int padlen;
480
481 kfree(ESP_SKB_CB(skb)->tmp);
482
483 if (unlikely(err))
484 goto out;
485
486 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
487 BUG();
488
489 err = -EINVAL;
490 padlen = nexthdr[0];
491 if (padlen + 2 + alen >= elen)
492 goto out;
493
494 /* ... check padding bits here. Silly. :-) */
495
496 iph = ip_hdr(skb);
497 ihl = iph->ihl * 4;
498
499 if (x->encap) {
500 struct xfrm_encap_tmpl *encap = x->encap;
501 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
502
503 /*
504 * 1) if the NAT-T peer's IP or port changed then
505 * advertize the change to the keying daemon.
506 * This is an inbound SA, so just compare
507 * SRC ports.
508 */
509 if (iph->saddr != x->props.saddr.a4 ||
510 uh->source != encap->encap_sport) {
511 xfrm_address_t ipaddr;
512
513 ipaddr.a4 = iph->saddr;
514 km_new_mapping(x, &ipaddr, uh->source);
515
516 /* XXX: perhaps add an extra
517 * policy check here, to see
518 * if we should allow or
519 * reject a packet from a
520 * different source
521 * address/port.
522 */
523 }
524
525 /*
526 * 2) ignore UDP/TCP checksums in case
527 * of NAT-T in Transport Mode, or
528 * perform other post-processing fixes
529 * as per draft-ietf-ipsec-udp-encaps-06,
530 * section 3.1.2
531 */
532 if (x->props.mode == XFRM_MODE_TRANSPORT)
533 skb->ip_summed = CHECKSUM_UNNECESSARY;
534 }
535
536 pskb_trim(skb, skb->len - alen - padlen - 2);
537 __skb_pull(skb, hlen);
538 if (x->props.mode == XFRM_MODE_TUNNEL)
539 skb_reset_transport_header(skb);
540 else
541 skb_set_transport_header(skb, -ihl);
542
543 err = nexthdr[1];
544
545 /* RFC4303: Drop dummy packets without any error */
546 if (err == IPPROTO_NONE)
547 err = -EINVAL;
548
549 out:
550 return err;
551 }
552
553 static void esp_input_done(struct crypto_async_request *base, int err)
554 {
555 struct sk_buff *skb = base->data;
556
557 xfrm_input_resume(skb, esp_input_done2(skb, err));
558 }
559
560 static void esp_input_restore_header(struct sk_buff *skb)
561 {
562 esp_restore_header(skb, 0);
563 __skb_pull(skb, 4);
564 }
565
566 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
567 {
568 struct xfrm_state *x = xfrm_input_state(skb);
569 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)skb->data;
570
571 /* For ESN we move the header forward by 4 bytes to
572 * accomodate the high bits. We will move it back after
573 * decryption.
574 */
575 if ((x->props.flags & XFRM_STATE_ESN)) {
576 esph = (void *)skb_push(skb, 4);
577 *seqhi = esph->spi;
578 esph->spi = esph->seq_no;
579 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
580 }
581 }
582
583 static void esp_input_done_esn(struct crypto_async_request *base, int err)
584 {
585 struct sk_buff *skb = base->data;
586
587 esp_input_restore_header(skb);
588 esp_input_done(base, err);
589 }
590
591 /*
592 * Note: detecting truncated vs. non-truncated authentication data is very
593 * expensive, so we only support truncated data, which is the recommended
594 * and common case.
595 */
596 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
597 {
598 struct ip_esp_hdr *esph;
599 struct crypto_aead *aead = x->data;
600 struct aead_request *req;
601 struct sk_buff *trailer;
602 int ivlen = crypto_aead_ivsize(aead);
603 int elen = skb->len - sizeof(*esph) - ivlen;
604 int nfrags;
605 int assoclen;
606 int seqhilen;
607 __be32 *seqhi;
608 void *tmp;
609 u8 *iv;
610 struct scatterlist *sg;
611 int err = -EINVAL;
612
613 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
614 goto out;
615
616 if (elen <= 0)
617 goto out;
618
619 assoclen = sizeof(*esph);
620 seqhilen = 0;
621
622 if (x->props.flags & XFRM_STATE_ESN) {
623 seqhilen += sizeof(__be32);
624 assoclen += seqhilen;
625 }
626
627 if (!skb_cloned(skb)) {
628 if (!skb_is_nonlinear(skb)) {
629 nfrags = 1;
630
631 goto skip_cow;
632 } else if (!skb_has_frag_list(skb)) {
633 nfrags = skb_shinfo(skb)->nr_frags;
634 nfrags++;
635
636 goto skip_cow;
637 }
638 }
639
640 err = skb_cow_data(skb, 0, &trailer);
641 if (err < 0)
642 goto out;
643
644 nfrags = err;
645
646 skip_cow:
647 err = -ENOMEM;
648 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
649 if (!tmp)
650 goto out;
651
652 ESP_SKB_CB(skb)->tmp = tmp;
653 seqhi = esp_tmp_extra(tmp);
654 iv = esp_tmp_iv(aead, tmp, seqhilen);
655 req = esp_tmp_req(aead, iv);
656 sg = esp_req_sg(aead, req);
657
658 esp_input_set_header(skb, seqhi);
659
660 sg_init_table(sg, nfrags);
661 skb_to_sgvec(skb, sg, 0, skb->len);
662
663 skb->ip_summed = CHECKSUM_NONE;
664
665 if ((x->props.flags & XFRM_STATE_ESN))
666 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
667 else
668 aead_request_set_callback(req, 0, esp_input_done, skb);
669
670 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
671 aead_request_set_ad(req, assoclen);
672
673 err = crypto_aead_decrypt(req);
674 if (err == -EINPROGRESS)
675 goto out;
676
677 if ((x->props.flags & XFRM_STATE_ESN))
678 esp_input_restore_header(skb);
679
680 err = esp_input_done2(skb, err);
681
682 out:
683 return err;
684 }
685
686 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
687 {
688 struct crypto_aead *aead = x->data;
689 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
690 unsigned int net_adj;
691
692 switch (x->props.mode) {
693 case XFRM_MODE_TRANSPORT:
694 case XFRM_MODE_BEET:
695 net_adj = sizeof(struct iphdr);
696 break;
697 case XFRM_MODE_TUNNEL:
698 net_adj = 0;
699 break;
700 default:
701 BUG();
702 }
703
704 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
705 net_adj) & ~(blksize - 1)) + net_adj - 2;
706 }
707
708 static int esp4_err(struct sk_buff *skb, u32 info)
709 {
710 struct net *net = dev_net(skb->dev);
711 const struct iphdr *iph = (const struct iphdr *)skb->data;
712 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
713 struct xfrm_state *x;
714
715 switch (icmp_hdr(skb)->type) {
716 case ICMP_DEST_UNREACH:
717 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
718 return 0;
719 case ICMP_REDIRECT:
720 break;
721 default:
722 return 0;
723 }
724
725 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
726 esph->spi, IPPROTO_ESP, AF_INET);
727 if (!x)
728 return 0;
729
730 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
731 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
732 else
733 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
734 xfrm_state_put(x);
735
736 return 0;
737 }
738
739 static void esp_destroy(struct xfrm_state *x)
740 {
741 struct crypto_aead *aead = x->data;
742
743 if (!aead)
744 return;
745
746 crypto_free_aead(aead);
747 }
748
749 static int esp_init_aead(struct xfrm_state *x)
750 {
751 char aead_name[CRYPTO_MAX_ALG_NAME];
752 struct crypto_aead *aead;
753 int err;
754
755 err = -ENAMETOOLONG;
756 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
757 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
758 goto error;
759
760 aead = crypto_alloc_aead(aead_name, 0, 0);
761 err = PTR_ERR(aead);
762 if (IS_ERR(aead))
763 goto error;
764
765 x->data = aead;
766
767 err = crypto_aead_setkey(aead, x->aead->alg_key,
768 (x->aead->alg_key_len + 7) / 8);
769 if (err)
770 goto error;
771
772 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
773 if (err)
774 goto error;
775
776 error:
777 return err;
778 }
779
780 static int esp_init_authenc(struct xfrm_state *x)
781 {
782 struct crypto_aead *aead;
783 struct crypto_authenc_key_param *param;
784 struct rtattr *rta;
785 char *key;
786 char *p;
787 char authenc_name[CRYPTO_MAX_ALG_NAME];
788 unsigned int keylen;
789 int err;
790
791 err = -EINVAL;
792 if (!x->ealg)
793 goto error;
794
795 err = -ENAMETOOLONG;
796
797 if ((x->props.flags & XFRM_STATE_ESN)) {
798 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
799 "%s%sauthencesn(%s,%s)%s",
800 x->geniv ?: "", x->geniv ? "(" : "",
801 x->aalg ? x->aalg->alg_name : "digest_null",
802 x->ealg->alg_name,
803 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
804 goto error;
805 } else {
806 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
807 "%s%sauthenc(%s,%s)%s",
808 x->geniv ?: "", x->geniv ? "(" : "",
809 x->aalg ? x->aalg->alg_name : "digest_null",
810 x->ealg->alg_name,
811 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
812 goto error;
813 }
814
815 aead = crypto_alloc_aead(authenc_name, 0, 0);
816 err = PTR_ERR(aead);
817 if (IS_ERR(aead))
818 goto error;
819
820 x->data = aead;
821
822 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
823 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
824 err = -ENOMEM;
825 key = kmalloc(keylen, GFP_KERNEL);
826 if (!key)
827 goto error;
828
829 p = key;
830 rta = (void *)p;
831 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
832 rta->rta_len = RTA_LENGTH(sizeof(*param));
833 param = RTA_DATA(rta);
834 p += RTA_SPACE(sizeof(*param));
835
836 if (x->aalg) {
837 struct xfrm_algo_desc *aalg_desc;
838
839 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
840 p += (x->aalg->alg_key_len + 7) / 8;
841
842 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
843 BUG_ON(!aalg_desc);
844
845 err = -EINVAL;
846 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
847 crypto_aead_authsize(aead)) {
848 pr_info("ESP: %s digestsize %u != %hu\n",
849 x->aalg->alg_name,
850 crypto_aead_authsize(aead),
851 aalg_desc->uinfo.auth.icv_fullbits / 8);
852 goto free_key;
853 }
854
855 err = crypto_aead_setauthsize(
856 aead, x->aalg->alg_trunc_len / 8);
857 if (err)
858 goto free_key;
859 }
860
861 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
862 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
863
864 err = crypto_aead_setkey(aead, key, keylen);
865
866 free_key:
867 kfree(key);
868
869 error:
870 return err;
871 }
872
873 static int esp_init_state(struct xfrm_state *x)
874 {
875 struct crypto_aead *aead;
876 u32 align;
877 int err;
878
879 x->data = NULL;
880
881 if (x->aead)
882 err = esp_init_aead(x);
883 else
884 err = esp_init_authenc(x);
885
886 if (err)
887 goto error;
888
889 aead = x->data;
890
891 x->props.header_len = sizeof(struct ip_esp_hdr) +
892 crypto_aead_ivsize(aead);
893 if (x->props.mode == XFRM_MODE_TUNNEL)
894 x->props.header_len += sizeof(struct iphdr);
895 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
896 x->props.header_len += IPV4_BEET_PHMAXLEN;
897 if (x->encap) {
898 struct xfrm_encap_tmpl *encap = x->encap;
899
900 switch (encap->encap_type) {
901 default:
902 goto error;
903 case UDP_ENCAP_ESPINUDP:
904 x->props.header_len += sizeof(struct udphdr);
905 break;
906 case UDP_ENCAP_ESPINUDP_NON_IKE:
907 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
908 break;
909 }
910 }
911
912 align = ALIGN(crypto_aead_blocksize(aead), 4);
913 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
914
915 error:
916 return err;
917 }
918
919 static int esp4_rcv_cb(struct sk_buff *skb, int err)
920 {
921 return 0;
922 }
923
924 static const struct xfrm_type esp_type =
925 {
926 .description = "ESP4",
927 .owner = THIS_MODULE,
928 .proto = IPPROTO_ESP,
929 .flags = XFRM_TYPE_REPLAY_PROT,
930 .init_state = esp_init_state,
931 .destructor = esp_destroy,
932 .get_mtu = esp4_get_mtu,
933 .input = esp_input,
934 .output = esp_output
935 };
936
937 static struct xfrm4_protocol esp4_protocol = {
938 .handler = xfrm4_rcv,
939 .input_handler = xfrm_input,
940 .cb_handler = esp4_rcv_cb,
941 .err_handler = esp4_err,
942 .priority = 0,
943 };
944
945 static int __init esp4_init(void)
946 {
947 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
948 pr_info("%s: can't add xfrm type\n", __func__);
949 return -EAGAIN;
950 }
951 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
952 pr_info("%s: can't add protocol\n", __func__);
953 xfrm_unregister_type(&esp_type, AF_INET);
954 return -EAGAIN;
955 }
956 return 0;
957 }
958
959 static void __exit esp4_fini(void)
960 {
961 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
962 pr_info("%s: can't remove protocol\n", __func__);
963 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
964 pr_info("%s: can't remove xfrm type\n", __func__);
965 }
966
967 module_init(esp4_init);
968 module_exit(esp4_fini);
969 MODULE_LICENSE("GPL");
970 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
Linux with added FPC-III support