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 struct esp_skb_cb {
22 struct xfrm_skb_cb xfrm;
23 void *tmp;
24 };
25
26 struct esp_output_extra {
27 __be32 seqhi;
28 u32 esphoff;
29 };
30
31 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
32
33 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu);
34
35 /*
36 * Allocate an AEAD request structure with extra space for SG and IV.
37 *
38 * For alignment considerations the IV is placed at the front, followed
39 * by the request and finally the SG list.
40 *
41 * TODO: Use spare space in skb for this where possible.
42 */
esp_alloc_tmp(struct crypto_aead * aead,int nfrags,int extralen)43 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
44 {
45 unsigned int len;
46
47 len = extralen;
48
49 len += crypto_aead_ivsize(aead);
50
51 if (len) {
52 len += crypto_aead_alignmask(aead) &
53 ~(crypto_tfm_ctx_alignment() - 1);
54 len = ALIGN(len, crypto_tfm_ctx_alignment());
55 }
56
57 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
58 len = ALIGN(len, __alignof__(struct scatterlist));
59
60 len += sizeof(struct scatterlist) * nfrags;
61
62 return kmalloc(len, GFP_ATOMIC);
63 }
64
esp_tmp_extra(void * tmp)65 static inline void *esp_tmp_extra(void *tmp)
66 {
67 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
68 }
69
esp_tmp_iv(struct crypto_aead * aead,void * tmp,int extralen)70 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
71 {
72 return crypto_aead_ivsize(aead) ?
73 PTR_ALIGN((u8 *)tmp + extralen,
74 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
75 }
76
esp_tmp_req(struct crypto_aead * aead,u8 * iv)77 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
78 {
79 struct aead_request *req;
80
81 req = (void *)PTR_ALIGN(iv + crypto_aead_ivsize(aead),
82 crypto_tfm_ctx_alignment());
83 aead_request_set_tfm(req, aead);
84 return req;
85 }
86
esp_req_sg(struct crypto_aead * aead,struct aead_request * req)87 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
88 struct aead_request *req)
89 {
90 return (void *)ALIGN((unsigned long)(req + 1) +
91 crypto_aead_reqsize(aead),
92 __alignof__(struct scatterlist));
93 }
94
esp_output_done(struct crypto_async_request * base,int err)95 static void esp_output_done(struct crypto_async_request *base, int err)
96 {
97 struct sk_buff *skb = base->data;
98
99 kfree(ESP_SKB_CB(skb)->tmp);
100 xfrm_output_resume(skb, err);
101 }
102
103 /* Move ESP header back into place. */
esp_restore_header(struct sk_buff * skb,unsigned int offset)104 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
105 {
106 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
107 void *tmp = ESP_SKB_CB(skb)->tmp;
108 __be32 *seqhi = esp_tmp_extra(tmp);
109
110 esph->seq_no = esph->spi;
111 esph->spi = *seqhi;
112 }
113
esp_output_restore_header(struct sk_buff * skb)114 static void esp_output_restore_header(struct sk_buff *skb)
115 {
116 void *tmp = ESP_SKB_CB(skb)->tmp;
117 struct esp_output_extra *extra = esp_tmp_extra(tmp);
118
119 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
120 sizeof(__be32));
121 }
122
esp_output_done_esn(struct crypto_async_request * base,int err)123 static void esp_output_done_esn(struct crypto_async_request *base, int err)
124 {
125 struct sk_buff *skb = base->data;
126
127 esp_output_restore_header(skb);
128 esp_output_done(base, err);
129 }
130
esp_output(struct xfrm_state * x,struct sk_buff * skb)131 static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
132 {
133 int err;
134 struct esp_output_extra *extra;
135 struct ip_esp_hdr *esph;
136 struct crypto_aead *aead;
137 struct aead_request *req;
138 struct scatterlist *sg;
139 struct sk_buff *trailer;
140 void *tmp;
141 u8 *iv;
142 u8 *tail;
143 int blksize;
144 int clen;
145 int alen;
146 int plen;
147 int ivlen;
148 int tfclen;
149 int nfrags;
150 int assoclen;
151 int extralen;
152 __be64 seqno;
153
154 /* skb is pure payload to encrypt */
155
156 aead = x->data;
157 alen = crypto_aead_authsize(aead);
158 ivlen = crypto_aead_ivsize(aead);
159
160 tfclen = 0;
161 if (x->tfcpad) {
162 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
163 u32 padto;
164
165 padto = min(x->tfcpad, esp4_get_mtu(x, dst->child_mtu_cached));
166 if (skb->len < padto)
167 tfclen = padto - skb->len;
168 }
169 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
170 clen = ALIGN(skb->len + 2 + tfclen, blksize);
171 plen = clen - skb->len - tfclen;
172
173 err = skb_cow_data(skb, tfclen + plen + alen, &trailer);
174 if (err < 0)
175 goto error;
176 nfrags = err;
177
178 assoclen = sizeof(*esph);
179 extralen = 0;
180
181 if (x->props.flags & XFRM_STATE_ESN) {
182 extralen += sizeof(*extra);
183 assoclen += sizeof(__be32);
184 }
185
186 tmp = esp_alloc_tmp(aead, nfrags, extralen);
187 if (!tmp) {
188 err = -ENOMEM;
189 goto error;
190 }
191
192 extra = esp_tmp_extra(tmp);
193 iv = esp_tmp_iv(aead, tmp, extralen);
194 req = esp_tmp_req(aead, iv);
195 sg = esp_req_sg(aead, req);
196
197 /* Fill padding... */
198 tail = skb_tail_pointer(trailer);
199 if (tfclen) {
200 memset(tail, 0, tfclen);
201 tail += tfclen;
202 }
203 do {
204 int i;
205 for (i = 0; i < plen - 2; i++)
206 tail[i] = i + 1;
207 } while (0);
208 tail[plen - 2] = plen - 2;
209 tail[plen - 1] = *skb_mac_header(skb);
210 pskb_put(skb, trailer, clen - skb->len + alen);
211
212 skb_push(skb, -skb_network_offset(skb));
213 esph = ip_esp_hdr(skb);
214 *skb_mac_header(skb) = IPPROTO_ESP;
215
216 /* this is non-NULL only with UDP Encapsulation */
217 if (x->encap) {
218 struct xfrm_encap_tmpl *encap = x->encap;
219 struct udphdr *uh;
220 __be32 *udpdata32;
221 __be16 sport, dport;
222 int encap_type;
223
224 spin_lock_bh(&x->lock);
225 sport = encap->encap_sport;
226 dport = encap->encap_dport;
227 encap_type = encap->encap_type;
228 spin_unlock_bh(&x->lock);
229
230 uh = (struct udphdr *)esph;
231 uh->source = sport;
232 uh->dest = dport;
233 uh->len = htons(skb->len - skb_transport_offset(skb));
234 uh->check = 0;
235
236 switch (encap_type) {
237 default:
238 case UDP_ENCAP_ESPINUDP:
239 esph = (struct ip_esp_hdr *)(uh + 1);
240 break;
241 case UDP_ENCAP_ESPINUDP_NON_IKE:
242 udpdata32 = (__be32 *)(uh + 1);
243 udpdata32[0] = udpdata32[1] = 0;
244 esph = (struct ip_esp_hdr *)(udpdata32 + 2);
245 break;
246 }
247
248 *skb_mac_header(skb) = IPPROTO_UDP;
249 }
250
251 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
252
253 aead_request_set_callback(req, 0, esp_output_done, skb);
254
255 /* For ESN we move the header forward by 4 bytes to
256 * accomodate the high bits. We will move it back after
257 * encryption.
258 */
259 if ((x->props.flags & XFRM_STATE_ESN)) {
260 extra->esphoff = (unsigned char *)esph -
261 skb_transport_header(skb);
262 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
263 extra->seqhi = esph->spi;
264 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.hi);
265 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
266 }
267
268 esph->spi = x->id.spi;
269
270 sg_init_table(sg, nfrags);
271 err = skb_to_sgvec(skb, sg,
272 (unsigned char *)esph - skb->data,
273 assoclen + ivlen + clen + alen);
274 if (unlikely(err < 0))
275 goto error;
276 aead_request_set_crypt(req, sg, sg, ivlen + clen, iv);
277 aead_request_set_ad(req, assoclen);
278
279 seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
280 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
281
282 memset(iv, 0, ivlen);
283 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&seqno + 8 - min(ivlen, 8),
284 min(ivlen, 8));
285
286 ESP_SKB_CB(skb)->tmp = tmp;
287 err = crypto_aead_encrypt(req);
288
289 switch (err) {
290 case -EINPROGRESS:
291 goto error;
292
293 case -EBUSY:
294 err = NET_XMIT_DROP;
295 break;
296
297 case 0:
298 if ((x->props.flags & XFRM_STATE_ESN))
299 esp_output_restore_header(skb);
300 }
301
302 kfree(tmp);
303
304 error:
305 return err;
306 }
307
esp_input_done2(struct sk_buff * skb,int err)308 static int esp_input_done2(struct sk_buff *skb, int err)
309 {
310 const struct iphdr *iph;
311 struct xfrm_state *x = xfrm_input_state(skb);
312 struct crypto_aead *aead = x->data;
313 int alen = crypto_aead_authsize(aead);
314 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
315 int elen = skb->len - hlen;
316 int ihl;
317 u8 nexthdr[2];
318 int padlen;
319
320 kfree(ESP_SKB_CB(skb)->tmp);
321
322 if (unlikely(err))
323 goto out;
324
325 if (skb_copy_bits(skb, skb->len-alen-2, nexthdr, 2))
326 BUG();
327
328 err = -EINVAL;
329 padlen = nexthdr[0];
330 if (padlen + 2 + alen >= elen)
331 goto out;
332
333 /* ... check padding bits here. Silly. :-) */
334
335 iph = ip_hdr(skb);
336 ihl = iph->ihl * 4;
337
338 if (x->encap) {
339 struct xfrm_encap_tmpl *encap = x->encap;
340 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
341
342 /*
343 * 1) if the NAT-T peer's IP or port changed then
344 * advertize the change to the keying daemon.
345 * This is an inbound SA, so just compare
346 * SRC ports.
347 */
348 if (iph->saddr != x->props.saddr.a4 ||
349 uh->source != encap->encap_sport) {
350 xfrm_address_t ipaddr;
351
352 ipaddr.a4 = iph->saddr;
353 km_new_mapping(x, &ipaddr, uh->source);
354
355 /* XXX: perhaps add an extra
356 * policy check here, to see
357 * if we should allow or
358 * reject a packet from a
359 * different source
360 * address/port.
361 */
362 }
363
364 /*
365 * 2) ignore UDP/TCP checksums in case
366 * of NAT-T in Transport Mode, or
367 * perform other post-processing fixes
368 * as per draft-ietf-ipsec-udp-encaps-06,
369 * section 3.1.2
370 */
371 if (x->props.mode == XFRM_MODE_TRANSPORT)
372 skb->ip_summed = CHECKSUM_UNNECESSARY;
373 }
374
375 pskb_trim(skb, skb->len - alen - padlen - 2);
376 __skb_pull(skb, hlen);
377 if (x->props.mode == XFRM_MODE_TUNNEL)
378 skb_reset_transport_header(skb);
379 else
380 skb_set_transport_header(skb, -ihl);
381
382 err = nexthdr[1];
383
384 /* RFC4303: Drop dummy packets without any error */
385 if (err == IPPROTO_NONE)
386 err = -EINVAL;
387
388 out:
389 return err;
390 }
391
esp_input_done(struct crypto_async_request * base,int err)392 static void esp_input_done(struct crypto_async_request *base, int err)
393 {
394 struct sk_buff *skb = base->data;
395
396 xfrm_input_resume(skb, esp_input_done2(skb, err));
397 }
398
esp_input_restore_header(struct sk_buff * skb)399 static void esp_input_restore_header(struct sk_buff *skb)
400 {
401 esp_restore_header(skb, 0);
402 __skb_pull(skb, 4);
403 }
404
esp_input_done_esn(struct crypto_async_request * base,int err)405 static void esp_input_done_esn(struct crypto_async_request *base, int err)
406 {
407 struct sk_buff *skb = base->data;
408
409 esp_input_restore_header(skb);
410 esp_input_done(base, err);
411 }
412
413 /*
414 * Note: detecting truncated vs. non-truncated authentication data is very
415 * expensive, so we only support truncated data, which is the recommended
416 * and common case.
417 */
esp_input(struct xfrm_state * x,struct sk_buff * skb)418 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
419 {
420 struct ip_esp_hdr *esph;
421 struct crypto_aead *aead = x->data;
422 struct aead_request *req;
423 struct sk_buff *trailer;
424 int ivlen = crypto_aead_ivsize(aead);
425 int elen = skb->len - sizeof(*esph) - ivlen;
426 int nfrags;
427 int assoclen;
428 int seqhilen;
429 __be32 *seqhi;
430 void *tmp;
431 u8 *iv;
432 struct scatterlist *sg;
433 int err = -EINVAL;
434
435 if (!pskb_may_pull(skb, sizeof(*esph) + ivlen))
436 goto out;
437
438 if (elen <= 0)
439 goto out;
440
441 err = skb_cow_data(skb, 0, &trailer);
442 if (err < 0)
443 goto out;
444
445 nfrags = err;
446
447 assoclen = sizeof(*esph);
448 seqhilen = 0;
449
450 if (x->props.flags & XFRM_STATE_ESN) {
451 seqhilen += sizeof(__be32);
452 assoclen += seqhilen;
453 }
454
455 err = -ENOMEM;
456 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
457 if (!tmp)
458 goto out;
459
460 ESP_SKB_CB(skb)->tmp = tmp;
461 seqhi = esp_tmp_extra(tmp);
462 iv = esp_tmp_iv(aead, tmp, seqhilen);
463 req = esp_tmp_req(aead, iv);
464 sg = esp_req_sg(aead, req);
465
466 skb->ip_summed = CHECKSUM_NONE;
467
468 esph = (struct ip_esp_hdr *)skb->data;
469
470 aead_request_set_callback(req, 0, esp_input_done, skb);
471
472 /* For ESN we move the header forward by 4 bytes to
473 * accomodate the high bits. We will move it back after
474 * decryption.
475 */
476 if ((x->props.flags & XFRM_STATE_ESN)) {
477 esph = (void *)skb_push(skb, 4);
478 *seqhi = esph->spi;
479 esph->spi = esph->seq_no;
480 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
481 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
482 }
483
484 sg_init_table(sg, nfrags);
485 err = skb_to_sgvec(skb, sg, 0, skb->len);
486 if (unlikely(err < 0))
487 goto out;
488
489 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
490 aead_request_set_ad(req, assoclen);
491
492 err = crypto_aead_decrypt(req);
493 if (err == -EINPROGRESS)
494 goto out;
495
496 if ((x->props.flags & XFRM_STATE_ESN))
497 esp_input_restore_header(skb);
498
499 err = esp_input_done2(skb, err);
500
501 out:
502 return err;
503 }
504
esp4_get_mtu(struct xfrm_state * x,int mtu)505 static u32 esp4_get_mtu(struct xfrm_state *x, int mtu)
506 {
507 struct crypto_aead *aead = x->data;
508 u32 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
509 unsigned int net_adj;
510
511 switch (x->props.mode) {
512 case XFRM_MODE_TRANSPORT:
513 case XFRM_MODE_BEET:
514 net_adj = sizeof(struct iphdr);
515 break;
516 case XFRM_MODE_TUNNEL:
517 net_adj = 0;
518 break;
519 default:
520 BUG();
521 }
522
523 return ((mtu - x->props.header_len - crypto_aead_authsize(aead) -
524 net_adj) & ~(blksize - 1)) + net_adj - 2;
525 }
526
esp4_err(struct sk_buff * skb,u32 info)527 static int esp4_err(struct sk_buff *skb, u32 info)
528 {
529 struct net *net = dev_net(skb->dev);
530 const struct iphdr *iph = (const struct iphdr *)skb->data;
531 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
532 struct xfrm_state *x;
533
534 switch (icmp_hdr(skb)->type) {
535 case ICMP_DEST_UNREACH:
536 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
537 return 0;
538 case ICMP_REDIRECT:
539 break;
540 default:
541 return 0;
542 }
543
544 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
545 esph->spi, IPPROTO_ESP, AF_INET);
546 if (!x)
547 return 0;
548
549 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
550 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ESP, 0);
551 else
552 ipv4_redirect(skb, net, 0, 0, IPPROTO_ESP, 0);
553 xfrm_state_put(x);
554
555 return 0;
556 }
557
esp_destroy(struct xfrm_state * x)558 static void esp_destroy(struct xfrm_state *x)
559 {
560 struct crypto_aead *aead = x->data;
561
562 if (!aead)
563 return;
564
565 crypto_free_aead(aead);
566 }
567
esp_init_aead(struct xfrm_state * x)568 static int esp_init_aead(struct xfrm_state *x)
569 {
570 char aead_name[CRYPTO_MAX_ALG_NAME];
571 struct crypto_aead *aead;
572 int err;
573
574 err = -ENAMETOOLONG;
575 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
576 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
577 goto error;
578
579 aead = crypto_alloc_aead(aead_name, 0, 0);
580 err = PTR_ERR(aead);
581 if (IS_ERR(aead))
582 goto error;
583
584 x->data = aead;
585
586 err = crypto_aead_setkey(aead, x->aead->alg_key,
587 (x->aead->alg_key_len + 7) / 8);
588 if (err)
589 goto error;
590
591 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
592 if (err)
593 goto error;
594
595 error:
596 return err;
597 }
598
esp_init_authenc(struct xfrm_state * x)599 static int esp_init_authenc(struct xfrm_state *x)
600 {
601 struct crypto_aead *aead;
602 struct crypto_authenc_key_param *param;
603 struct rtattr *rta;
604 char *key;
605 char *p;
606 char authenc_name[CRYPTO_MAX_ALG_NAME];
607 unsigned int keylen;
608 int err;
609
610 err = -EINVAL;
611 if (!x->ealg)
612 goto error;
613
614 err = -ENAMETOOLONG;
615
616 if ((x->props.flags & XFRM_STATE_ESN)) {
617 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
618 "%s%sauthencesn(%s,%s)%s",
619 x->geniv ?: "", x->geniv ? "(" : "",
620 x->aalg ? x->aalg->alg_name : "digest_null",
621 x->ealg->alg_name,
622 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
623 goto error;
624 } else {
625 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
626 "%s%sauthenc(%s,%s)%s",
627 x->geniv ?: "", x->geniv ? "(" : "",
628 x->aalg ? x->aalg->alg_name : "digest_null",
629 x->ealg->alg_name,
630 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
631 goto error;
632 }
633
634 aead = crypto_alloc_aead(authenc_name, 0, 0);
635 err = PTR_ERR(aead);
636 if (IS_ERR(aead))
637 goto error;
638
639 x->data = aead;
640
641 keylen = (x->aalg ? (x->aalg->alg_key_len + 7) / 8 : 0) +
642 (x->ealg->alg_key_len + 7) / 8 + RTA_SPACE(sizeof(*param));
643 err = -ENOMEM;
644 key = kmalloc(keylen, GFP_KERNEL);
645 if (!key)
646 goto error;
647
648 p = key;
649 rta = (void *)p;
650 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
651 rta->rta_len = RTA_LENGTH(sizeof(*param));
652 param = RTA_DATA(rta);
653 p += RTA_SPACE(sizeof(*param));
654
655 if (x->aalg) {
656 struct xfrm_algo_desc *aalg_desc;
657
658 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
659 p += (x->aalg->alg_key_len + 7) / 8;
660
661 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
662 BUG_ON(!aalg_desc);
663
664 err = -EINVAL;
665 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
666 crypto_aead_authsize(aead)) {
667 pr_info("ESP: %s digestsize %u != %hu\n",
668 x->aalg->alg_name,
669 crypto_aead_authsize(aead),
670 aalg_desc->uinfo.auth.icv_fullbits / 8);
671 goto free_key;
672 }
673
674 err = crypto_aead_setauthsize(
675 aead, x->aalg->alg_trunc_len / 8);
676 if (err)
677 goto free_key;
678 }
679
680 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
681 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
682
683 err = crypto_aead_setkey(aead, key, keylen);
684
685 free_key:
686 kfree(key);
687
688 error:
689 return err;
690 }
691
esp_init_state(struct xfrm_state * x)692 static int esp_init_state(struct xfrm_state *x)
693 {
694 struct crypto_aead *aead;
695 u32 align;
696 int err;
697
698 x->data = NULL;
699
700 if (x->aead)
701 err = esp_init_aead(x);
702 else
703 err = esp_init_authenc(x);
704
705 if (err)
706 goto error;
707
708 aead = x->data;
709
710 x->props.header_len = sizeof(struct ip_esp_hdr) +
711 crypto_aead_ivsize(aead);
712 if (x->props.mode == XFRM_MODE_TUNNEL)
713 x->props.header_len += sizeof(struct iphdr);
714 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
715 x->props.header_len += IPV4_BEET_PHMAXLEN;
716 if (x->encap) {
717 struct xfrm_encap_tmpl *encap = x->encap;
718
719 switch (encap->encap_type) {
720 default:
721 goto error;
722 case UDP_ENCAP_ESPINUDP:
723 x->props.header_len += sizeof(struct udphdr);
724 break;
725 case UDP_ENCAP_ESPINUDP_NON_IKE:
726 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
727 break;
728 }
729 }
730
731 align = ALIGN(crypto_aead_blocksize(aead), 4);
732 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
733
734 error:
735 return err;
736 }
737
esp4_rcv_cb(struct sk_buff * skb,int err)738 static int esp4_rcv_cb(struct sk_buff *skb, int err)
739 {
740 return 0;
741 }
742
743 static const struct xfrm_type esp_type =
744 {
745 .description = "ESP4",
746 .owner = THIS_MODULE,
747 .proto = IPPROTO_ESP,
748 .flags = XFRM_TYPE_REPLAY_PROT,
749 .init_state = esp_init_state,
750 .destructor = esp_destroy,
751 .get_mtu = esp4_get_mtu,
752 .input = esp_input,
753 .output = esp_output
754 };
755
756 static struct xfrm4_protocol esp4_protocol = {
757 .handler = xfrm4_rcv,
758 .input_handler = xfrm_input,
759 .cb_handler = esp4_rcv_cb,
760 .err_handler = esp4_err,
761 .priority = 0,
762 };
763
esp4_init(void)764 static int __init esp4_init(void)
765 {
766 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
767 pr_info("%s: can't add xfrm type\n", __func__);
768 return -EAGAIN;
769 }
770 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
771 pr_info("%s: can't add protocol\n", __func__);
772 xfrm_unregister_type(&esp_type, AF_INET);
773 return -EAGAIN;
774 }
775 return 0;
776 }
777
esp4_fini(void)778 static void __exit esp4_fini(void)
779 {
780 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
781 pr_info("%s: can't remove protocol\n", __func__);
782 if (xfrm_unregister_type(&esp_type, AF_INET) < 0)
783 pr_info("%s: can't remove xfrm type\n", __func__);
784 }
785
786 module_init(esp4_init);
787 module_exit(esp4_fini);
788 MODULE_LICENSE("GPL");
789 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);
790