1 #define pr_fmt(fmt) "IPsec: " fmt
3 #include <crypto/aead.h>
4 #include <crypto/authenc.h>
6 #include <linux/module.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>
18 #include <net/protocol.h>
22 struct xfrm_skb_cb xfrm
;
26 #define ESP_SKB_CB(__skb) ((struct esp_skb_cb *)&((__skb)->cb[0]))
28 static u32
esp4_get_mtu(struct xfrm_state
*x
, int mtu
);
31 * Allocate an AEAD request structure with extra space for SG and IV.
33 * For alignment considerations the IV is placed at the front, followed
34 * by the request and finally the SG list.
36 * TODO: Use spare space in skb for this where possible.
38 static void *esp_alloc_tmp(struct crypto_aead
*aead
, int nfrags
, int seqhilen
)
44 len
+= crypto_aead_ivsize(aead
);
47 len
+= crypto_aead_alignmask(aead
) &
48 ~(crypto_tfm_ctx_alignment() - 1);
49 len
= ALIGN(len
, crypto_tfm_ctx_alignment());
52 len
+= sizeof(struct aead_request
) + crypto_aead_reqsize(aead
);
53 len
= ALIGN(len
, __alignof__(struct scatterlist
));
55 len
+= sizeof(struct scatterlist
) * nfrags
;
57 return kmalloc(len
, GFP_ATOMIC
);
60 static inline __be32
*esp_tmp_seqhi(void *tmp
)
62 return PTR_ALIGN((__be32
*)tmp
, __alignof__(__be32
));
64 static inline u8
*esp_tmp_iv(struct crypto_aead
*aead
, void *tmp
, int seqhilen
)
66 return crypto_aead_ivsize(aead
) ?
67 PTR_ALIGN((u8
*)tmp
+ seqhilen
,
68 crypto_aead_alignmask(aead
) + 1) : tmp
+ seqhilen
;
71 static inline struct aead_request
*esp_tmp_req(struct crypto_aead
*aead
, u8
*iv
)
73 struct aead_request
*req
;
75 req
= (void *)PTR_ALIGN(iv
+ crypto_aead_ivsize(aead
),
76 crypto_tfm_ctx_alignment());
77 aead_request_set_tfm(req
, aead
);
81 static inline struct scatterlist
*esp_req_sg(struct crypto_aead
*aead
,
82 struct aead_request
*req
)
84 return (void *)ALIGN((unsigned long)(req
+ 1) +
85 crypto_aead_reqsize(aead
),
86 __alignof__(struct scatterlist
));
89 static void esp_output_done(struct crypto_async_request
*base
, int err
)
91 struct sk_buff
*skb
= base
->data
;
93 kfree(ESP_SKB_CB(skb
)->tmp
);
94 xfrm_output_resume(skb
, err
);
97 /* Move ESP header back into place. */
98 static void esp_restore_header(struct sk_buff
*skb
, unsigned int offset
)
100 struct ip_esp_hdr
*esph
= (void *)(skb
->data
+ offset
);
101 void *tmp
= ESP_SKB_CB(skb
)->tmp
;
102 __be32
*seqhi
= esp_tmp_seqhi(tmp
);
104 esph
->seq_no
= esph
->spi
;
108 static void esp_output_restore_header(struct sk_buff
*skb
)
110 esp_restore_header(skb
, skb_transport_offset(skb
) - sizeof(__be32
));
113 static void esp_output_done_esn(struct crypto_async_request
*base
, int err
)
115 struct sk_buff
*skb
= base
->data
;
117 esp_output_restore_header(skb
);
118 esp_output_done(base
, err
);
121 static int esp_output(struct xfrm_state
*x
, struct sk_buff
*skb
)
124 struct ip_esp_hdr
*esph
;
125 struct crypto_aead
*aead
;
126 struct aead_request
*req
;
127 struct scatterlist
*sg
;
128 struct sk_buff
*trailer
;
144 /* skb is pure payload to encrypt */
147 alen
= crypto_aead_authsize(aead
);
148 ivlen
= crypto_aead_ivsize(aead
);
152 struct xfrm_dst
*dst
= (struct xfrm_dst
*)skb_dst(skb
);
155 padto
= min(x
->tfcpad
, esp4_get_mtu(x
, dst
->child_mtu_cached
));
156 if (skb
->len
< padto
)
157 tfclen
= padto
- skb
->len
;
159 blksize
= ALIGN(crypto_aead_blocksize(aead
), 4);
160 clen
= ALIGN(skb
->len
+ 2 + tfclen
, blksize
);
161 plen
= clen
- skb
->len
- tfclen
;
163 err
= skb_cow_data(skb
, tfclen
+ plen
+ alen
, &trailer
);
168 assoclen
= sizeof(*esph
);
171 if (x
->props
.flags
& XFRM_STATE_ESN
) {
172 seqhilen
+= sizeof(__be32
);
173 assoclen
+= seqhilen
;
176 tmp
= esp_alloc_tmp(aead
, nfrags
, seqhilen
);
182 seqhi
= esp_tmp_seqhi(tmp
);
183 iv
= esp_tmp_iv(aead
, tmp
, seqhilen
);
184 req
= esp_tmp_req(aead
, iv
);
185 sg
= esp_req_sg(aead
, req
);
187 /* Fill padding... */
188 tail
= skb_tail_pointer(trailer
);
190 memset(tail
, 0, tfclen
);
195 for (i
= 0; i
< plen
- 2; i
++)
198 tail
[plen
- 2] = plen
- 2;
199 tail
[plen
- 1] = *skb_mac_header(skb
);
200 pskb_put(skb
, trailer
, clen
- skb
->len
+ alen
);
202 skb_push(skb
, -skb_network_offset(skb
));
203 esph
= ip_esp_hdr(skb
);
204 *skb_mac_header(skb
) = IPPROTO_ESP
;
206 /* this is non-NULL only with UDP Encapsulation */
208 struct xfrm_encap_tmpl
*encap
= x
->encap
;
214 spin_lock_bh(&x
->lock
);
215 sport
= encap
->encap_sport
;
216 dport
= encap
->encap_dport
;
217 encap_type
= encap
->encap_type
;
218 spin_unlock_bh(&x
->lock
);
220 uh
= (struct udphdr
*)esph
;
223 uh
->len
= htons(skb
->len
- skb_transport_offset(skb
));
226 switch (encap_type
) {
228 case UDP_ENCAP_ESPINUDP
:
229 esph
= (struct ip_esp_hdr
*)(uh
+ 1);
231 case UDP_ENCAP_ESPINUDP_NON_IKE
:
232 udpdata32
= (__be32
*)(uh
+ 1);
233 udpdata32
[0] = udpdata32
[1] = 0;
234 esph
= (struct ip_esp_hdr
*)(udpdata32
+ 2);
238 *skb_mac_header(skb
) = IPPROTO_UDP
;
241 esph
->seq_no
= htonl(XFRM_SKB_CB(skb
)->seq
.output
.low
);
243 aead_request_set_callback(req
, 0, esp_output_done
, skb
);
245 /* For ESN we move the header forward by 4 bytes to
246 * accomodate the high bits. We will move it back after
249 if ((x
->props
.flags
& XFRM_STATE_ESN
)) {
250 esph
= (void *)(skb_transport_header(skb
) - sizeof(__be32
));
252 esph
->seq_no
= htonl(XFRM_SKB_CB(skb
)->seq
.output
.hi
);
253 aead_request_set_callback(req
, 0, esp_output_done_esn
, skb
);
256 esph
->spi
= x
->id
.spi
;
258 sg_init_table(sg
, nfrags
);
259 skb_to_sgvec(skb
, sg
,
260 (unsigned char *)esph
- skb
->data
,
261 assoclen
+ ivlen
+ clen
+ alen
);
263 aead_request_set_crypt(req
, sg
, sg
, ivlen
+ clen
, iv
);
264 aead_request_set_ad(req
, assoclen
);
266 seqno
= cpu_to_be64(XFRM_SKB_CB(skb
)->seq
.output
.low
+
267 ((u64
)XFRM_SKB_CB(skb
)->seq
.output
.hi
<< 32));
269 memset(iv
, 0, ivlen
);
270 memcpy(iv
+ ivlen
- min(ivlen
, 8), (u8
*)&seqno
+ 8 - min(ivlen
, 8),
273 ESP_SKB_CB(skb
)->tmp
= tmp
;
274 err
= crypto_aead_encrypt(req
);
285 if ((x
->props
.flags
& XFRM_STATE_ESN
))
286 esp_output_restore_header(skb
);
295 static int esp_input_done2(struct sk_buff
*skb
, int err
)
297 const struct iphdr
*iph
;
298 struct xfrm_state
*x
= xfrm_input_state(skb
);
299 struct crypto_aead
*aead
= x
->data
;
300 int alen
= crypto_aead_authsize(aead
);
301 int hlen
= sizeof(struct ip_esp_hdr
) + crypto_aead_ivsize(aead
);
302 int elen
= skb
->len
- hlen
;
307 kfree(ESP_SKB_CB(skb
)->tmp
);
312 if (skb_copy_bits(skb
, skb
->len
-alen
-2, nexthdr
, 2))
317 if (padlen
+ 2 + alen
>= elen
)
320 /* ... check padding bits here. Silly. :-) */
326 struct xfrm_encap_tmpl
*encap
= x
->encap
;
327 struct udphdr
*uh
= (void *)(skb_network_header(skb
) + ihl
);
330 * 1) if the NAT-T peer's IP or port changed then
331 * advertize the change to the keying daemon.
332 * This is an inbound SA, so just compare
335 if (iph
->saddr
!= x
->props
.saddr
.a4
||
336 uh
->source
!= encap
->encap_sport
) {
337 xfrm_address_t ipaddr
;
339 ipaddr
.a4
= iph
->saddr
;
340 km_new_mapping(x
, &ipaddr
, uh
->source
);
342 /* XXX: perhaps add an extra
343 * policy check here, to see
344 * if we should allow or
345 * reject a packet from a
352 * 2) ignore UDP/TCP checksums in case
353 * of NAT-T in Transport Mode, or
354 * perform other post-processing fixes
355 * as per draft-ietf-ipsec-udp-encaps-06,
358 if (x
->props
.mode
== XFRM_MODE_TRANSPORT
)
359 skb
->ip_summed
= CHECKSUM_UNNECESSARY
;
362 pskb_trim(skb
, skb
->len
- alen
- padlen
- 2);
363 __skb_pull(skb
, hlen
);
364 if (x
->props
.mode
== XFRM_MODE_TUNNEL
)
365 skb_reset_transport_header(skb
);
367 skb_set_transport_header(skb
, -ihl
);
371 /* RFC4303: Drop dummy packets without any error */
372 if (err
== IPPROTO_NONE
)
379 static void esp_input_done(struct crypto_async_request
*base
, int err
)
381 struct sk_buff
*skb
= base
->data
;
383 xfrm_input_resume(skb
, esp_input_done2(skb
, err
));
386 static void esp_input_restore_header(struct sk_buff
*skb
)
388 esp_restore_header(skb
, 0);
392 static void esp_input_done_esn(struct crypto_async_request
*base
, int err
)
394 struct sk_buff
*skb
= base
->data
;
396 esp_input_restore_header(skb
);
397 esp_input_done(base
, err
);
401 * Note: detecting truncated vs. non-truncated authentication data is very
402 * expensive, so we only support truncated data, which is the recommended
405 static int esp_input(struct xfrm_state
*x
, struct sk_buff
*skb
)
407 struct ip_esp_hdr
*esph
;
408 struct crypto_aead
*aead
= x
->data
;
409 struct aead_request
*req
;
410 struct sk_buff
*trailer
;
411 int ivlen
= crypto_aead_ivsize(aead
);
412 int elen
= skb
->len
- sizeof(*esph
) - ivlen
;
419 struct scatterlist
*sg
;
422 if (!pskb_may_pull(skb
, sizeof(*esph
) + ivlen
))
428 err
= skb_cow_data(skb
, 0, &trailer
);
434 assoclen
= sizeof(*esph
);
437 if (x
->props
.flags
& XFRM_STATE_ESN
) {
438 seqhilen
+= sizeof(__be32
);
439 assoclen
+= seqhilen
;
443 tmp
= esp_alloc_tmp(aead
, nfrags
, seqhilen
);
447 ESP_SKB_CB(skb
)->tmp
= tmp
;
448 seqhi
= esp_tmp_seqhi(tmp
);
449 iv
= esp_tmp_iv(aead
, tmp
, seqhilen
);
450 req
= esp_tmp_req(aead
, iv
);
451 sg
= esp_req_sg(aead
, req
);
453 skb
->ip_summed
= CHECKSUM_NONE
;
455 esph
= (struct ip_esp_hdr
*)skb
->data
;
457 aead_request_set_callback(req
, 0, esp_input_done
, skb
);
459 /* For ESN we move the header forward by 4 bytes to
460 * accomodate the high bits. We will move it back after
463 if ((x
->props
.flags
& XFRM_STATE_ESN
)) {
464 esph
= (void *)skb_push(skb
, 4);
466 esph
->spi
= esph
->seq_no
;
467 esph
->seq_no
= htonl(XFRM_SKB_CB(skb
)->seq
.input
.hi
);
468 aead_request_set_callback(req
, 0, esp_input_done_esn
, skb
);
471 sg_init_table(sg
, nfrags
);
472 skb_to_sgvec(skb
, sg
, 0, skb
->len
);
474 aead_request_set_crypt(req
, sg
, sg
, elen
+ ivlen
, iv
);
475 aead_request_set_ad(req
, assoclen
);
477 err
= crypto_aead_decrypt(req
);
478 if (err
== -EINPROGRESS
)
481 if ((x
->props
.flags
& XFRM_STATE_ESN
))
482 esp_input_restore_header(skb
);
484 err
= esp_input_done2(skb
, err
);
490 static u32
esp4_get_mtu(struct xfrm_state
*x
, int mtu
)
492 struct crypto_aead
*aead
= x
->data
;
493 u32 blksize
= ALIGN(crypto_aead_blocksize(aead
), 4);
494 unsigned int net_adj
;
496 switch (x
->props
.mode
) {
497 case XFRM_MODE_TRANSPORT
:
499 net_adj
= sizeof(struct iphdr
);
501 case XFRM_MODE_TUNNEL
:
508 return ((mtu
- x
->props
.header_len
- crypto_aead_authsize(aead
) -
509 net_adj
) & ~(blksize
- 1)) + net_adj
- 2;
512 static int esp4_err(struct sk_buff
*skb
, u32 info
)
514 struct net
*net
= dev_net(skb
->dev
);
515 const struct iphdr
*iph
= (const struct iphdr
*)skb
->data
;
516 struct ip_esp_hdr
*esph
= (struct ip_esp_hdr
*)(skb
->data
+(iph
->ihl
<<2));
517 struct xfrm_state
*x
;
519 switch (icmp_hdr(skb
)->type
) {
520 case ICMP_DEST_UNREACH
:
521 if (icmp_hdr(skb
)->code
!= ICMP_FRAG_NEEDED
)
529 x
= xfrm_state_lookup(net
, skb
->mark
, (const xfrm_address_t
*)&iph
->daddr
,
530 esph
->spi
, IPPROTO_ESP
, AF_INET
);
534 if (icmp_hdr(skb
)->type
== ICMP_DEST_UNREACH
)
535 ipv4_update_pmtu(skb
, net
, info
, 0, 0, IPPROTO_ESP
, 0);
537 ipv4_redirect(skb
, net
, 0, 0, IPPROTO_ESP
, 0);
543 static void esp_destroy(struct xfrm_state
*x
)
545 struct crypto_aead
*aead
= x
->data
;
550 crypto_free_aead(aead
);
553 static int esp_init_aead(struct xfrm_state
*x
)
555 char aead_name
[CRYPTO_MAX_ALG_NAME
];
556 struct crypto_aead
*aead
;
560 if (snprintf(aead_name
, CRYPTO_MAX_ALG_NAME
, "%s(%s)",
561 x
->geniv
, x
->aead
->alg_name
) >= CRYPTO_MAX_ALG_NAME
)
564 aead
= crypto_alloc_aead(aead_name
, 0, 0);
571 err
= crypto_aead_setkey(aead
, x
->aead
->alg_key
,
572 (x
->aead
->alg_key_len
+ 7) / 8);
576 err
= crypto_aead_setauthsize(aead
, x
->aead
->alg_icv_len
/ 8);
584 static int esp_init_authenc(struct xfrm_state
*x
)
586 struct crypto_aead
*aead
;
587 struct crypto_authenc_key_param
*param
;
591 char authenc_name
[CRYPTO_MAX_ALG_NAME
];
601 if ((x
->props
.flags
& XFRM_STATE_ESN
)) {
602 if (snprintf(authenc_name
, CRYPTO_MAX_ALG_NAME
,
603 "%s%sauthencesn(%s,%s)%s",
604 x
->geniv
?: "", x
->geniv
? "(" : "",
605 x
->aalg
? x
->aalg
->alg_name
: "digest_null",
607 x
->geniv
? ")" : "") >= CRYPTO_MAX_ALG_NAME
)
610 if (snprintf(authenc_name
, CRYPTO_MAX_ALG_NAME
,
611 "%s%sauthenc(%s,%s)%s",
612 x
->geniv
?: "", x
->geniv
? "(" : "",
613 x
->aalg
? x
->aalg
->alg_name
: "digest_null",
615 x
->geniv
? ")" : "") >= CRYPTO_MAX_ALG_NAME
)
619 aead
= crypto_alloc_aead(authenc_name
, 0, 0);
626 keylen
= (x
->aalg
? (x
->aalg
->alg_key_len
+ 7) / 8 : 0) +
627 (x
->ealg
->alg_key_len
+ 7) / 8 + RTA_SPACE(sizeof(*param
));
629 key
= kmalloc(keylen
, GFP_KERNEL
);
635 rta
->rta_type
= CRYPTO_AUTHENC_KEYA_PARAM
;
636 rta
->rta_len
= RTA_LENGTH(sizeof(*param
));
637 param
= RTA_DATA(rta
);
638 p
+= RTA_SPACE(sizeof(*param
));
641 struct xfrm_algo_desc
*aalg_desc
;
643 memcpy(p
, x
->aalg
->alg_key
, (x
->aalg
->alg_key_len
+ 7) / 8);
644 p
+= (x
->aalg
->alg_key_len
+ 7) / 8;
646 aalg_desc
= xfrm_aalg_get_byname(x
->aalg
->alg_name
, 0);
650 if (aalg_desc
->uinfo
.auth
.icv_fullbits
/ 8 !=
651 crypto_aead_authsize(aead
)) {
652 pr_info("ESP: %s digestsize %u != %hu\n",
654 crypto_aead_authsize(aead
),
655 aalg_desc
->uinfo
.auth
.icv_fullbits
/ 8);
659 err
= crypto_aead_setauthsize(
660 aead
, x
->aalg
->alg_trunc_len
/ 8);
665 param
->enckeylen
= cpu_to_be32((x
->ealg
->alg_key_len
+ 7) / 8);
666 memcpy(p
, x
->ealg
->alg_key
, (x
->ealg
->alg_key_len
+ 7) / 8);
668 err
= crypto_aead_setkey(aead
, key
, keylen
);
677 static int esp_init_state(struct xfrm_state
*x
)
679 struct crypto_aead
*aead
;
686 err
= esp_init_aead(x
);
688 err
= esp_init_authenc(x
);
695 x
->props
.header_len
= sizeof(struct ip_esp_hdr
) +
696 crypto_aead_ivsize(aead
);
697 if (x
->props
.mode
== XFRM_MODE_TUNNEL
)
698 x
->props
.header_len
+= sizeof(struct iphdr
);
699 else if (x
->props
.mode
== XFRM_MODE_BEET
&& x
->sel
.family
!= AF_INET6
)
700 x
->props
.header_len
+= IPV4_BEET_PHMAXLEN
;
702 struct xfrm_encap_tmpl
*encap
= x
->encap
;
704 switch (encap
->encap_type
) {
707 case UDP_ENCAP_ESPINUDP
:
708 x
->props
.header_len
+= sizeof(struct udphdr
);
710 case UDP_ENCAP_ESPINUDP_NON_IKE
:
711 x
->props
.header_len
+= sizeof(struct udphdr
) + 2 * sizeof(u32
);
716 align
= ALIGN(crypto_aead_blocksize(aead
), 4);
717 x
->props
.trailer_len
= align
+ 1 + crypto_aead_authsize(aead
);
723 static int esp4_rcv_cb(struct sk_buff
*skb
, int err
)
728 static const struct xfrm_type esp_type
=
730 .description
= "ESP4",
731 .owner
= THIS_MODULE
,
732 .proto
= IPPROTO_ESP
,
733 .flags
= XFRM_TYPE_REPLAY_PROT
,
734 .init_state
= esp_init_state
,
735 .destructor
= esp_destroy
,
736 .get_mtu
= esp4_get_mtu
,
741 static struct xfrm4_protocol esp4_protocol
= {
742 .handler
= xfrm4_rcv
,
743 .input_handler
= xfrm_input
,
744 .cb_handler
= esp4_rcv_cb
,
745 .err_handler
= esp4_err
,
749 static int __init
esp4_init(void)
751 if (xfrm_register_type(&esp_type
, AF_INET
) < 0) {
752 pr_info("%s: can't add xfrm type\n", __func__
);
755 if (xfrm4_protocol_register(&esp4_protocol
, IPPROTO_ESP
) < 0) {
756 pr_info("%s: can't add protocol\n", __func__
);
757 xfrm_unregister_type(&esp_type
, AF_INET
);
763 static void __exit
esp4_fini(void)
765 if (xfrm4_protocol_deregister(&esp4_protocol
, IPPROTO_ESP
) < 0)
766 pr_info("%s: can't remove protocol\n", __func__
);
767 if (xfrm_unregister_type(&esp_type
, AF_INET
) < 0)
768 pr_info("%s: can't remove xfrm type\n", __func__
);
771 module_init(esp4_init
);
772 module_exit(esp4_fini
);
773 MODULE_LICENSE("GPL");
774 MODULE_ALIAS_XFRM_TYPE(AF_INET
, XFRM_PROTO_ESP
);