gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / net / ipv4 / esp4.c
blob8b07f3a4f2db2509bed581ab549c09b621c8b7ea
1 // SPDX-License-Identifier: GPL-2.0-only
2 #define pr_fmt(fmt) "IPsec: " fmt
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>
24 #include <linux/highmem.h>
26 struct esp_skb_cb {
27 struct xfrm_skb_cb xfrm;
28 void *tmp;
31 struct esp_output_extra {
32 __be32 seqhi;
33 u32 esphoff;
36 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
39 * Allocate an AEAD request structure with extra space for SG and IV.
41 * For alignment considerations the IV is placed at the front, followed
42 * by the request and finally the SG list.
44 * TODO: Use spare space in skb for this where possible.
46 static void *esp_alloc_tmp(struct crypto_aead *aead, int nfrags, int extralen)
48 unsigned int len;
50 len = extralen;
52 len += crypto_aead_ivsize(aead);
54 if (len) {
55 len += crypto_aead_alignmask(aead) &
56 ~(crypto_tfm_ctx_alignment() - 1);
57 len = ALIGN(len, crypto_tfm_ctx_alignment());
60 len += sizeof(struct aead_request) + crypto_aead_reqsize(aead);
61 len = ALIGN(len, __alignof__(struct scatterlist));
63 len += sizeof(struct scatterlist) * nfrags;
65 return kmalloc(len, GFP_ATOMIC);
68 static inline void *esp_tmp_extra(void *tmp)
70 return PTR_ALIGN(tmp, __alignof__(struct esp_output_extra));
73 static inline u8 *esp_tmp_iv(struct crypto_aead *aead, void *tmp, int extralen)
75 return crypto_aead_ivsize(aead) ?
76 PTR_ALIGN((u8 *)tmp + extralen,
77 crypto_aead_alignmask(aead) + 1) : tmp + extralen;
80 static inline struct aead_request *esp_tmp_req(struct crypto_aead *aead, u8 *iv)
82 struct aead_request *req;
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;
90 static inline struct scatterlist *esp_req_sg(struct crypto_aead *aead,
91 struct aead_request *req)
93 return (void *)ALIGN((unsigned long)(req + 1) +
94 crypto_aead_reqsize(aead),
95 __alignof__(struct scatterlist));
98 static void esp_ssg_unref(struct xfrm_state *x, void *tmp)
100 struct esp_output_extra *extra = esp_tmp_extra(tmp);
101 struct crypto_aead *aead = x->data;
102 int extralen = 0;
103 u8 *iv;
104 struct aead_request *req;
105 struct scatterlist *sg;
107 if (x->props.flags & XFRM_STATE_ESN)
108 extralen += sizeof(*extra);
110 extra = esp_tmp_extra(tmp);
111 iv = esp_tmp_iv(aead, tmp, extralen);
112 req = esp_tmp_req(aead, iv);
114 /* Unref skb_frag_pages in the src scatterlist if necessary.
115 * Skip the first sg which comes from skb->data.
117 if (req->src != req->dst)
118 for (sg = sg_next(req->src); sg; sg = sg_next(sg))
119 put_page(sg_page(sg));
122 #ifdef CONFIG_INET_ESPINTCP
123 struct esp_tcp_sk {
124 struct sock *sk;
125 struct rcu_head rcu;
128 static void esp_free_tcp_sk(struct rcu_head *head)
130 struct esp_tcp_sk *esk = container_of(head, struct esp_tcp_sk, rcu);
132 sock_put(esk->sk);
133 kfree(esk);
136 static struct sock *esp_find_tcp_sk(struct xfrm_state *x)
138 struct xfrm_encap_tmpl *encap = x->encap;
139 struct esp_tcp_sk *esk;
140 __be16 sport, dport;
141 struct sock *nsk;
142 struct sock *sk;
144 sk = rcu_dereference(x->encap_sk);
145 if (sk && sk->sk_state == TCP_ESTABLISHED)
146 return sk;
148 spin_lock_bh(&x->lock);
149 sport = encap->encap_sport;
150 dport = encap->encap_dport;
151 nsk = rcu_dereference_protected(x->encap_sk,
152 lockdep_is_held(&x->lock));
153 if (sk && sk == nsk) {
154 esk = kmalloc(sizeof(*esk), GFP_ATOMIC);
155 if (!esk) {
156 spin_unlock_bh(&x->lock);
157 return ERR_PTR(-ENOMEM);
159 RCU_INIT_POINTER(x->encap_sk, NULL);
160 esk->sk = sk;
161 call_rcu(&esk->rcu, esp_free_tcp_sk);
163 spin_unlock_bh(&x->lock);
165 sk = inet_lookup_established(xs_net(x), &tcp_hashinfo, x->id.daddr.a4,
166 dport, x->props.saddr.a4, sport, 0);
167 if (!sk)
168 return ERR_PTR(-ENOENT);
170 if (!tcp_is_ulp_esp(sk)) {
171 sock_put(sk);
172 return ERR_PTR(-EINVAL);
175 spin_lock_bh(&x->lock);
176 nsk = rcu_dereference_protected(x->encap_sk,
177 lockdep_is_held(&x->lock));
178 if (encap->encap_sport != sport ||
179 encap->encap_dport != dport) {
180 sock_put(sk);
181 sk = nsk ?: ERR_PTR(-EREMCHG);
182 } else if (sk == nsk) {
183 sock_put(sk);
184 } else {
185 rcu_assign_pointer(x->encap_sk, sk);
187 spin_unlock_bh(&x->lock);
189 return sk;
192 static int esp_output_tcp_finish(struct xfrm_state *x, struct sk_buff *skb)
194 struct sock *sk;
195 int err;
197 rcu_read_lock();
199 sk = esp_find_tcp_sk(x);
200 err = PTR_ERR_OR_ZERO(sk);
201 if (err)
202 goto out;
204 bh_lock_sock(sk);
205 if (sock_owned_by_user(sk))
206 err = espintcp_queue_out(sk, skb);
207 else
208 err = espintcp_push_skb(sk, skb);
209 bh_unlock_sock(sk);
211 out:
212 rcu_read_unlock();
213 return err;
216 static int esp_output_tcp_encap_cb(struct net *net, struct sock *sk,
217 struct sk_buff *skb)
219 struct dst_entry *dst = skb_dst(skb);
220 struct xfrm_state *x = dst->xfrm;
222 return esp_output_tcp_finish(x, skb);
225 static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
227 int err;
229 local_bh_disable();
230 err = xfrm_trans_queue_net(xs_net(x), skb, esp_output_tcp_encap_cb);
231 local_bh_enable();
233 /* EINPROGRESS just happens to do the right thing. It
234 * actually means that the skb has been consumed and
235 * isn't coming back.
237 return err ?: -EINPROGRESS;
239 #else
240 static int esp_output_tail_tcp(struct xfrm_state *x, struct sk_buff *skb)
242 kfree_skb(skb);
244 return -EOPNOTSUPP;
246 #endif
248 static void esp_output_done(struct crypto_async_request *base, int err)
250 struct sk_buff *skb = base->data;
251 struct xfrm_offload *xo = xfrm_offload(skb);
252 void *tmp;
253 struct xfrm_state *x;
255 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
256 struct sec_path *sp = skb_sec_path(skb);
258 x = sp->xvec[sp->len - 1];
259 } else {
260 x = skb_dst(skb)->xfrm;
263 tmp = ESP_SKB_CB(skb)->tmp;
264 esp_ssg_unref(x, tmp);
265 kfree(tmp);
267 if (xo && (xo->flags & XFRM_DEV_RESUME)) {
268 if (err) {
269 XFRM_INC_STATS(xs_net(x), LINUX_MIB_XFRMOUTSTATEPROTOERROR);
270 kfree_skb(skb);
271 return;
274 skb_push(skb, skb->data - skb_mac_header(skb));
275 secpath_reset(skb);
276 xfrm_dev_resume(skb);
277 } else {
278 if (!err &&
279 x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
280 esp_output_tail_tcp(x, skb);
281 else
282 xfrm_output_resume(skb, err);
286 /* Move ESP header back into place. */
287 static void esp_restore_header(struct sk_buff *skb, unsigned int offset)
289 struct ip_esp_hdr *esph = (void *)(skb->data + offset);
290 void *tmp = ESP_SKB_CB(skb)->tmp;
291 __be32 *seqhi = esp_tmp_extra(tmp);
293 esph->seq_no = esph->spi;
294 esph->spi = *seqhi;
297 static void esp_output_restore_header(struct sk_buff *skb)
299 void *tmp = ESP_SKB_CB(skb)->tmp;
300 struct esp_output_extra *extra = esp_tmp_extra(tmp);
302 esp_restore_header(skb, skb_transport_offset(skb) + extra->esphoff -
303 sizeof(__be32));
306 static struct ip_esp_hdr *esp_output_set_extra(struct sk_buff *skb,
307 struct xfrm_state *x,
308 struct ip_esp_hdr *esph,
309 struct esp_output_extra *extra)
311 /* For ESN we move the header forward by 4 bytes to
312 * accomodate the high bits. We will move it back after
313 * encryption.
315 if ((x->props.flags & XFRM_STATE_ESN)) {
316 __u32 seqhi;
317 struct xfrm_offload *xo = xfrm_offload(skb);
319 if (xo)
320 seqhi = xo->seq.hi;
321 else
322 seqhi = XFRM_SKB_CB(skb)->seq.output.hi;
324 extra->esphoff = (unsigned char *)esph -
325 skb_transport_header(skb);
326 esph = (struct ip_esp_hdr *)((unsigned char *)esph - 4);
327 extra->seqhi = esph->spi;
328 esph->seq_no = htonl(seqhi);
331 esph->spi = x->id.spi;
333 return esph;
336 static void esp_output_done_esn(struct crypto_async_request *base, int err)
338 struct sk_buff *skb = base->data;
340 esp_output_restore_header(skb);
341 esp_output_done(base, err);
344 static struct ip_esp_hdr *esp_output_udp_encap(struct sk_buff *skb,
345 int encap_type,
346 struct esp_info *esp,
347 __be16 sport,
348 __be16 dport)
350 struct udphdr *uh;
351 __be32 *udpdata32;
352 unsigned int len;
354 len = skb->len + esp->tailen - skb_transport_offset(skb);
355 if (len + sizeof(struct iphdr) > IP_MAX_MTU)
356 return ERR_PTR(-EMSGSIZE);
358 uh = (struct udphdr *)esp->esph;
359 uh->source = sport;
360 uh->dest = dport;
361 uh->len = htons(len);
362 uh->check = 0;
364 *skb_mac_header(skb) = IPPROTO_UDP;
366 if (encap_type == UDP_ENCAP_ESPINUDP_NON_IKE) {
367 udpdata32 = (__be32 *)(uh + 1);
368 udpdata32[0] = udpdata32[1] = 0;
369 return (struct ip_esp_hdr *)(udpdata32 + 2);
372 return (struct ip_esp_hdr *)(uh + 1);
375 #ifdef CONFIG_INET_ESPINTCP
376 static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
377 struct sk_buff *skb,
378 struct esp_info *esp)
380 __be16 *lenp = (void *)esp->esph;
381 struct ip_esp_hdr *esph;
382 unsigned int len;
383 struct sock *sk;
385 len = skb->len + esp->tailen - skb_transport_offset(skb);
386 if (len > IP_MAX_MTU)
387 return ERR_PTR(-EMSGSIZE);
389 rcu_read_lock();
390 sk = esp_find_tcp_sk(x);
391 rcu_read_unlock();
393 if (IS_ERR(sk))
394 return ERR_CAST(sk);
396 *lenp = htons(len);
397 esph = (struct ip_esp_hdr *)(lenp + 1);
399 return esph;
401 #else
402 static struct ip_esp_hdr *esp_output_tcp_encap(struct xfrm_state *x,
403 struct sk_buff *skb,
404 struct esp_info *esp)
406 return ERR_PTR(-EOPNOTSUPP);
408 #endif
410 static int esp_output_encap(struct xfrm_state *x, struct sk_buff *skb,
411 struct esp_info *esp)
413 struct xfrm_encap_tmpl *encap = x->encap;
414 struct ip_esp_hdr *esph;
415 __be16 sport, dport;
416 int encap_type;
418 spin_lock_bh(&x->lock);
419 sport = encap->encap_sport;
420 dport = encap->encap_dport;
421 encap_type = encap->encap_type;
422 spin_unlock_bh(&x->lock);
424 switch (encap_type) {
425 default:
426 case UDP_ENCAP_ESPINUDP:
427 case UDP_ENCAP_ESPINUDP_NON_IKE:
428 esph = esp_output_udp_encap(skb, encap_type, esp, sport, dport);
429 break;
430 case TCP_ENCAP_ESPINTCP:
431 esph = esp_output_tcp_encap(x, skb, esp);
432 break;
435 if (IS_ERR(esph))
436 return PTR_ERR(esph);
438 esp->esph = esph;
440 return 0;
443 int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
445 u8 *tail;
446 u8 *vaddr;
447 int nfrags;
448 int esph_offset;
449 struct page *page;
450 struct sk_buff *trailer;
451 int tailen = esp->tailen;
453 /* this is non-NULL only with TCP/UDP Encapsulation */
454 if (x->encap) {
455 int err = esp_output_encap(x, skb, esp);
457 if (err < 0)
458 return err;
461 if (!skb_cloned(skb)) {
462 if (tailen <= skb_tailroom(skb)) {
463 nfrags = 1;
464 trailer = skb;
465 tail = skb_tail_pointer(trailer);
467 goto skip_cow;
468 } else if ((skb_shinfo(skb)->nr_frags < MAX_SKB_FRAGS)
469 && !skb_has_frag_list(skb)) {
470 int allocsize;
471 struct sock *sk = skb->sk;
472 struct page_frag *pfrag = &x->xfrag;
474 esp->inplace = false;
476 allocsize = ALIGN(tailen, L1_CACHE_BYTES);
478 spin_lock_bh(&x->lock);
480 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
481 spin_unlock_bh(&x->lock);
482 goto cow;
485 page = pfrag->page;
486 get_page(page);
488 vaddr = kmap_atomic(page);
490 tail = vaddr + pfrag->offset;
492 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
494 kunmap_atomic(vaddr);
496 nfrags = skb_shinfo(skb)->nr_frags;
498 __skb_fill_page_desc(skb, nfrags, page, pfrag->offset,
499 tailen);
500 skb_shinfo(skb)->nr_frags = ++nfrags;
502 pfrag->offset = pfrag->offset + allocsize;
504 spin_unlock_bh(&x->lock);
506 nfrags++;
508 skb->len += tailen;
509 skb->data_len += tailen;
510 skb->truesize += tailen;
511 if (sk && sk_fullsock(sk))
512 refcount_add(tailen, &sk->sk_wmem_alloc);
514 goto out;
518 cow:
519 esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
521 nfrags = skb_cow_data(skb, tailen, &trailer);
522 if (nfrags < 0)
523 goto out;
524 tail = skb_tail_pointer(trailer);
525 esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
527 skip_cow:
528 esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);
529 pskb_put(skb, trailer, tailen);
531 out:
532 return nfrags;
534 EXPORT_SYMBOL_GPL(esp_output_head);
536 int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
538 u8 *iv;
539 int alen;
540 void *tmp;
541 int ivlen;
542 int assoclen;
543 int extralen;
544 struct page *page;
545 struct ip_esp_hdr *esph;
546 struct crypto_aead *aead;
547 struct aead_request *req;
548 struct scatterlist *sg, *dsg;
549 struct esp_output_extra *extra;
550 int err = -ENOMEM;
552 assoclen = sizeof(struct ip_esp_hdr);
553 extralen = 0;
555 if (x->props.flags & XFRM_STATE_ESN) {
556 extralen += sizeof(*extra);
557 assoclen += sizeof(__be32);
560 aead = x->data;
561 alen = crypto_aead_authsize(aead);
562 ivlen = crypto_aead_ivsize(aead);
564 tmp = esp_alloc_tmp(aead, esp->nfrags + 2, extralen);
565 if (!tmp)
566 goto error;
568 extra = esp_tmp_extra(tmp);
569 iv = esp_tmp_iv(aead, tmp, extralen);
570 req = esp_tmp_req(aead, iv);
571 sg = esp_req_sg(aead, req);
573 if (esp->inplace)
574 dsg = sg;
575 else
576 dsg = &sg[esp->nfrags];
578 esph = esp_output_set_extra(skb, x, esp->esph, extra);
579 esp->esph = esph;
581 sg_init_table(sg, esp->nfrags);
582 err = skb_to_sgvec(skb, sg,
583 (unsigned char *)esph - skb->data,
584 assoclen + ivlen + esp->clen + alen);
585 if (unlikely(err < 0))
586 goto error_free;
588 if (!esp->inplace) {
589 int allocsize;
590 struct page_frag *pfrag = &x->xfrag;
592 allocsize = ALIGN(skb->data_len, L1_CACHE_BYTES);
594 spin_lock_bh(&x->lock);
595 if (unlikely(!skb_page_frag_refill(allocsize, pfrag, GFP_ATOMIC))) {
596 spin_unlock_bh(&x->lock);
597 goto error_free;
600 skb_shinfo(skb)->nr_frags = 1;
602 page = pfrag->page;
603 get_page(page);
604 /* replace page frags in skb with new page */
605 __skb_fill_page_desc(skb, 0, page, pfrag->offset, skb->data_len);
606 pfrag->offset = pfrag->offset + allocsize;
607 spin_unlock_bh(&x->lock);
609 sg_init_table(dsg, skb_shinfo(skb)->nr_frags + 1);
610 err = skb_to_sgvec(skb, dsg,
611 (unsigned char *)esph - skb->data,
612 assoclen + ivlen + esp->clen + alen);
613 if (unlikely(err < 0))
614 goto error_free;
617 if ((x->props.flags & XFRM_STATE_ESN))
618 aead_request_set_callback(req, 0, esp_output_done_esn, skb);
619 else
620 aead_request_set_callback(req, 0, esp_output_done, skb);
622 aead_request_set_crypt(req, sg, dsg, ivlen + esp->clen, iv);
623 aead_request_set_ad(req, assoclen);
625 memset(iv, 0, ivlen);
626 memcpy(iv + ivlen - min(ivlen, 8), (u8 *)&esp->seqno + 8 - min(ivlen, 8),
627 min(ivlen, 8));
629 ESP_SKB_CB(skb)->tmp = tmp;
630 err = crypto_aead_encrypt(req);
632 switch (err) {
633 case -EINPROGRESS:
634 goto error;
636 case -ENOSPC:
637 err = NET_XMIT_DROP;
638 break;
640 case 0:
641 if ((x->props.flags & XFRM_STATE_ESN))
642 esp_output_restore_header(skb);
645 if (sg != dsg)
646 esp_ssg_unref(x, tmp);
648 if (!err && x->encap && x->encap->encap_type == TCP_ENCAP_ESPINTCP)
649 err = esp_output_tail_tcp(x, skb);
651 error_free:
652 kfree(tmp);
653 error:
654 return err;
656 EXPORT_SYMBOL_GPL(esp_output_tail);
658 static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
660 int alen;
661 int blksize;
662 struct ip_esp_hdr *esph;
663 struct crypto_aead *aead;
664 struct esp_info esp;
666 esp.inplace = true;
668 esp.proto = *skb_mac_header(skb);
669 *skb_mac_header(skb) = IPPROTO_ESP;
671 /* skb is pure payload to encrypt */
673 aead = x->data;
674 alen = crypto_aead_authsize(aead);
676 esp.tfclen = 0;
677 if (x->tfcpad) {
678 struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb);
679 u32 padto;
681 padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached));
682 if (skb->len < padto)
683 esp.tfclen = padto - skb->len;
685 blksize = ALIGN(crypto_aead_blocksize(aead), 4);
686 esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize);
687 esp.plen = esp.clen - skb->len - esp.tfclen;
688 esp.tailen = esp.tfclen + esp.plen + alen;
690 esp.esph = ip_esp_hdr(skb);
692 esp.nfrags = esp_output_head(x, skb, &esp);
693 if (esp.nfrags < 0)
694 return esp.nfrags;
696 esph = esp.esph;
697 esph->spi = x->id.spi;
699 esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low);
700 esp.seqno = cpu_to_be64(XFRM_SKB_CB(skb)->seq.output.low +
701 ((u64)XFRM_SKB_CB(skb)->seq.output.hi << 32));
703 skb_push(skb, -skb_network_offset(skb));
705 return esp_output_tail(x, skb, &esp);
708 static inline int esp_remove_trailer(struct sk_buff *skb)
710 struct xfrm_state *x = xfrm_input_state(skb);
711 struct xfrm_offload *xo = xfrm_offload(skb);
712 struct crypto_aead *aead = x->data;
713 int alen, hlen, elen;
714 int padlen, trimlen;
715 __wsum csumdiff;
716 u8 nexthdr[2];
717 int ret;
719 alen = crypto_aead_authsize(aead);
720 hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
721 elen = skb->len - hlen;
723 if (xo && (xo->flags & XFRM_ESP_NO_TRAILER)) {
724 ret = xo->proto;
725 goto out;
728 if (skb_copy_bits(skb, skb->len - alen - 2, nexthdr, 2))
729 BUG();
731 ret = -EINVAL;
732 padlen = nexthdr[0];
733 if (padlen + 2 + alen >= elen) {
734 net_dbg_ratelimited("ipsec esp packet is garbage padlen=%d, elen=%d\n",
735 padlen + 2, elen - alen);
736 goto out;
739 trimlen = alen + padlen + 2;
740 if (skb->ip_summed == CHECKSUM_COMPLETE) {
741 csumdiff = skb_checksum(skb, skb->len - trimlen, trimlen, 0);
742 skb->csum = csum_block_sub(skb->csum, csumdiff,
743 skb->len - trimlen);
745 pskb_trim(skb, skb->len - trimlen);
747 ret = nexthdr[1];
749 out:
750 return ret;
753 int esp_input_done2(struct sk_buff *skb, int err)
755 const struct iphdr *iph;
756 struct xfrm_state *x = xfrm_input_state(skb);
757 struct xfrm_offload *xo = xfrm_offload(skb);
758 struct crypto_aead *aead = x->data;
759 int hlen = sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead);
760 int ihl;
762 if (!xo || (xo && !(xo->flags & CRYPTO_DONE)))
763 kfree(ESP_SKB_CB(skb)->tmp);
765 if (unlikely(err))
766 goto out;
768 err = esp_remove_trailer(skb);
769 if (unlikely(err < 0))
770 goto out;
772 iph = ip_hdr(skb);
773 ihl = iph->ihl * 4;
775 if (x->encap) {
776 struct xfrm_encap_tmpl *encap = x->encap;
777 struct tcphdr *th = (void *)(skb_network_header(skb) + ihl);
778 struct udphdr *uh = (void *)(skb_network_header(skb) + ihl);
779 __be16 source;
781 switch (x->encap->encap_type) {
782 case TCP_ENCAP_ESPINTCP:
783 source = th->source;
784 break;
785 case UDP_ENCAP_ESPINUDP:
786 case UDP_ENCAP_ESPINUDP_NON_IKE:
787 source = uh->source;
788 break;
789 default:
790 WARN_ON_ONCE(1);
791 err = -EINVAL;
792 goto out;
796 * 1) if the NAT-T peer's IP or port changed then
797 * advertize the change to the keying daemon.
798 * This is an inbound SA, so just compare
799 * SRC ports.
801 if (iph->saddr != x->props.saddr.a4 ||
802 source != encap->encap_sport) {
803 xfrm_address_t ipaddr;
805 ipaddr.a4 = iph->saddr;
806 km_new_mapping(x, &ipaddr, source);
808 /* XXX: perhaps add an extra
809 * policy check here, to see
810 * if we should allow or
811 * reject a packet from a
812 * different source
813 * address/port.
818 * 2) ignore UDP/TCP checksums in case
819 * of NAT-T in Transport Mode, or
820 * perform other post-processing fixes
821 * as per draft-ietf-ipsec-udp-encaps-06,
822 * section 3.1.2
824 if (x->props.mode == XFRM_MODE_TRANSPORT)
825 skb->ip_summed = CHECKSUM_UNNECESSARY;
828 skb_pull_rcsum(skb, hlen);
829 if (x->props.mode == XFRM_MODE_TUNNEL)
830 skb_reset_transport_header(skb);
831 else
832 skb_set_transport_header(skb, -ihl);
834 /* RFC4303: Drop dummy packets without any error */
835 if (err == IPPROTO_NONE)
836 err = -EINVAL;
838 out:
839 return err;
841 EXPORT_SYMBOL_GPL(esp_input_done2);
843 static void esp_input_done(struct crypto_async_request *base, int err)
845 struct sk_buff *skb = base->data;
847 xfrm_input_resume(skb, esp_input_done2(skb, err));
850 static void esp_input_restore_header(struct sk_buff *skb)
852 esp_restore_header(skb, 0);
853 __skb_pull(skb, 4);
856 static void esp_input_set_header(struct sk_buff *skb, __be32 *seqhi)
858 struct xfrm_state *x = xfrm_input_state(skb);
859 struct ip_esp_hdr *esph;
861 /* For ESN we move the header forward by 4 bytes to
862 * accomodate the high bits. We will move it back after
863 * decryption.
865 if ((x->props.flags & XFRM_STATE_ESN)) {
866 esph = skb_push(skb, 4);
867 *seqhi = esph->spi;
868 esph->spi = esph->seq_no;
869 esph->seq_no = XFRM_SKB_CB(skb)->seq.input.hi;
873 static void esp_input_done_esn(struct crypto_async_request *base, int err)
875 struct sk_buff *skb = base->data;
877 esp_input_restore_header(skb);
878 esp_input_done(base, err);
882 * Note: detecting truncated vs. non-truncated authentication data is very
883 * expensive, so we only support truncated data, which is the recommended
884 * and common case.
886 static int esp_input(struct xfrm_state *x, struct sk_buff *skb)
888 struct crypto_aead *aead = x->data;
889 struct aead_request *req;
890 struct sk_buff *trailer;
891 int ivlen = crypto_aead_ivsize(aead);
892 int elen = skb->len - sizeof(struct ip_esp_hdr) - ivlen;
893 int nfrags;
894 int assoclen;
895 int seqhilen;
896 __be32 *seqhi;
897 void *tmp;
898 u8 *iv;
899 struct scatterlist *sg;
900 int err = -EINVAL;
902 if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + ivlen))
903 goto out;
905 if (elen <= 0)
906 goto out;
908 assoclen = sizeof(struct ip_esp_hdr);
909 seqhilen = 0;
911 if (x->props.flags & XFRM_STATE_ESN) {
912 seqhilen += sizeof(__be32);
913 assoclen += seqhilen;
916 if (!skb_cloned(skb)) {
917 if (!skb_is_nonlinear(skb)) {
918 nfrags = 1;
920 goto skip_cow;
921 } else if (!skb_has_frag_list(skb)) {
922 nfrags = skb_shinfo(skb)->nr_frags;
923 nfrags++;
925 goto skip_cow;
929 err = skb_cow_data(skb, 0, &trailer);
930 if (err < 0)
931 goto out;
933 nfrags = err;
935 skip_cow:
936 err = -ENOMEM;
937 tmp = esp_alloc_tmp(aead, nfrags, seqhilen);
938 if (!tmp)
939 goto out;
941 ESP_SKB_CB(skb)->tmp = tmp;
942 seqhi = esp_tmp_extra(tmp);
943 iv = esp_tmp_iv(aead, tmp, seqhilen);
944 req = esp_tmp_req(aead, iv);
945 sg = esp_req_sg(aead, req);
947 esp_input_set_header(skb, seqhi);
949 sg_init_table(sg, nfrags);
950 err = skb_to_sgvec(skb, sg, 0, skb->len);
951 if (unlikely(err < 0)) {
952 kfree(tmp);
953 goto out;
956 skb->ip_summed = CHECKSUM_NONE;
958 if ((x->props.flags & XFRM_STATE_ESN))
959 aead_request_set_callback(req, 0, esp_input_done_esn, skb);
960 else
961 aead_request_set_callback(req, 0, esp_input_done, skb);
963 aead_request_set_crypt(req, sg, sg, elen + ivlen, iv);
964 aead_request_set_ad(req, assoclen);
966 err = crypto_aead_decrypt(req);
967 if (err == -EINPROGRESS)
968 goto out;
970 if ((x->props.flags & XFRM_STATE_ESN))
971 esp_input_restore_header(skb);
973 err = esp_input_done2(skb, err);
975 out:
976 return err;
979 static int esp4_err(struct sk_buff *skb, u32 info)
981 struct net *net = dev_net(skb->dev);
982 const struct iphdr *iph = (const struct iphdr *)skb->data;
983 struct ip_esp_hdr *esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
984 struct xfrm_state *x;
986 switch (icmp_hdr(skb)->type) {
987 case ICMP_DEST_UNREACH:
988 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
989 return 0;
990 case ICMP_REDIRECT:
991 break;
992 default:
993 return 0;
996 x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
997 esph->spi, IPPROTO_ESP, AF_INET);
998 if (!x)
999 return 0;
1001 if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
1002 ipv4_update_pmtu(skb, net, info, 0, IPPROTO_ESP);
1003 else
1004 ipv4_redirect(skb, net, 0, IPPROTO_ESP);
1005 xfrm_state_put(x);
1007 return 0;
1010 static void esp_destroy(struct xfrm_state *x)
1012 struct crypto_aead *aead = x->data;
1014 if (!aead)
1015 return;
1017 crypto_free_aead(aead);
1020 static int esp_init_aead(struct xfrm_state *x)
1022 char aead_name[CRYPTO_MAX_ALG_NAME];
1023 struct crypto_aead *aead;
1024 int err;
1026 err = -ENAMETOOLONG;
1027 if (snprintf(aead_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
1028 x->geniv, x->aead->alg_name) >= CRYPTO_MAX_ALG_NAME)
1029 goto error;
1031 aead = crypto_alloc_aead(aead_name, 0, 0);
1032 err = PTR_ERR(aead);
1033 if (IS_ERR(aead))
1034 goto error;
1036 x->data = aead;
1038 err = crypto_aead_setkey(aead, x->aead->alg_key,
1039 (x->aead->alg_key_len + 7) / 8);
1040 if (err)
1041 goto error;
1043 err = crypto_aead_setauthsize(aead, x->aead->alg_icv_len / 8);
1044 if (err)
1045 goto error;
1047 error:
1048 return err;
1051 static int esp_init_authenc(struct xfrm_state *x)
1053 struct crypto_aead *aead;
1054 struct crypto_authenc_key_param *param;
1055 struct rtattr *rta;
1056 char *key;
1057 char *p;
1058 char authenc_name[CRYPTO_MAX_ALG_NAME];
1059 unsigned int keylen;
1060 int err;
1062 err = -EINVAL;
1063 if (!x->ealg)
1064 goto error;
1066 err = -ENAMETOOLONG;
1068 if ((x->props.flags & XFRM_STATE_ESN)) {
1069 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1070 "%s%sauthencesn(%s,%s)%s",
1071 x->geniv ?: "", x->geniv ? "(" : "",
1072 x->aalg ? x->aalg->alg_name : "digest_null",
1073 x->ealg->alg_name,
1074 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1075 goto error;
1076 } else {
1077 if (snprintf(authenc_name, CRYPTO_MAX_ALG_NAME,
1078 "%s%sauthenc(%s,%s)%s",
1079 x->geniv ?: "", x->geniv ? "(" : "",
1080 x->aalg ? x->aalg->alg_name : "digest_null",
1081 x->ealg->alg_name,
1082 x->geniv ? ")" : "") >= CRYPTO_MAX_ALG_NAME)
1083 goto error;
1086 aead = crypto_alloc_aead(authenc_name, 0, 0);
1087 err = PTR_ERR(aead);
1088 if (IS_ERR(aead))
1089 goto error;
1091 x->data = aead;
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;
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));
1107 if (x->aalg) {
1108 struct xfrm_algo_desc *aalg_desc;
1110 memcpy(p, x->aalg->alg_key, (x->aalg->alg_key_len + 7) / 8);
1111 p += (x->aalg->alg_key_len + 7) / 8;
1113 aalg_desc = xfrm_aalg_get_byname(x->aalg->alg_name, 0);
1114 BUG_ON(!aalg_desc);
1116 err = -EINVAL;
1117 if (aalg_desc->uinfo.auth.icv_fullbits / 8 !=
1118 crypto_aead_authsize(aead)) {
1119 pr_info("ESP: %s digestsize %u != %hu\n",
1120 x->aalg->alg_name,
1121 crypto_aead_authsize(aead),
1122 aalg_desc->uinfo.auth.icv_fullbits / 8);
1123 goto free_key;
1126 err = crypto_aead_setauthsize(
1127 aead, x->aalg->alg_trunc_len / 8);
1128 if (err)
1129 goto free_key;
1132 param->enckeylen = cpu_to_be32((x->ealg->alg_key_len + 7) / 8);
1133 memcpy(p, x->ealg->alg_key, (x->ealg->alg_key_len + 7) / 8);
1135 err = crypto_aead_setkey(aead, key, keylen);
1137 free_key:
1138 kfree(key);
1140 error:
1141 return err;
1144 static int esp_init_state(struct xfrm_state *x)
1146 struct crypto_aead *aead;
1147 u32 align;
1148 int err;
1150 x->data = NULL;
1152 if (x->aead)
1153 err = esp_init_aead(x);
1154 else
1155 err = esp_init_authenc(x);
1157 if (err)
1158 goto error;
1160 aead = x->data;
1162 x->props.header_len = sizeof(struct ip_esp_hdr) +
1163 crypto_aead_ivsize(aead);
1164 if (x->props.mode == XFRM_MODE_TUNNEL)
1165 x->props.header_len += sizeof(struct iphdr);
1166 else if (x->props.mode == XFRM_MODE_BEET && x->sel.family != AF_INET6)
1167 x->props.header_len += IPV4_BEET_PHMAXLEN;
1168 if (x->encap) {
1169 struct xfrm_encap_tmpl *encap = x->encap;
1171 switch (encap->encap_type) {
1172 default:
1173 err = -EINVAL;
1174 goto error;
1175 case UDP_ENCAP_ESPINUDP:
1176 x->props.header_len += sizeof(struct udphdr);
1177 break;
1178 case UDP_ENCAP_ESPINUDP_NON_IKE:
1179 x->props.header_len += sizeof(struct udphdr) + 2 * sizeof(u32);
1180 break;
1181 #ifdef CONFIG_INET_ESPINTCP
1182 case TCP_ENCAP_ESPINTCP:
1183 /* only the length field, TCP encap is done by
1184 * the socket
1186 x->props.header_len += 2;
1187 break;
1188 #endif
1192 align = ALIGN(crypto_aead_blocksize(aead), 4);
1193 x->props.trailer_len = align + 1 + crypto_aead_authsize(aead);
1195 error:
1196 return err;
1199 static int esp4_rcv_cb(struct sk_buff *skb, int err)
1201 return 0;
1204 static const struct xfrm_type esp_type =
1206 .description = "ESP4",
1207 .owner = THIS_MODULE,
1208 .proto = IPPROTO_ESP,
1209 .flags = XFRM_TYPE_REPLAY_PROT,
1210 .init_state = esp_init_state,
1211 .destructor = esp_destroy,
1212 .input = esp_input,
1213 .output = esp_output,
1216 static struct xfrm4_protocol esp4_protocol = {
1217 .handler = xfrm4_rcv,
1218 .input_handler = xfrm_input,
1219 .cb_handler = esp4_rcv_cb,
1220 .err_handler = esp4_err,
1221 .priority = 0,
1224 static int __init esp4_init(void)
1226 if (xfrm_register_type(&esp_type, AF_INET) < 0) {
1227 pr_info("%s: can't add xfrm type\n", __func__);
1228 return -EAGAIN;
1230 if (xfrm4_protocol_register(&esp4_protocol, IPPROTO_ESP) < 0) {
1231 pr_info("%s: can't add protocol\n", __func__);
1232 xfrm_unregister_type(&esp_type, AF_INET);
1233 return -EAGAIN;
1235 return 0;
1238 static void __exit esp4_fini(void)
1240 if (xfrm4_protocol_deregister(&esp4_protocol, IPPROTO_ESP) < 0)
1241 pr_info("%s: can't remove protocol\n", __func__);
1242 xfrm_unregister_type(&esp_type, AF_INET);
1245 module_init(esp4_init);
1246 module_exit(esp4_fini);
1247 MODULE_LICENSE("GPL");
1248 MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_ESP);