-
Notifications
You must be signed in to change notification settings - Fork 102
/
macsec.c
4412 lines (3621 loc) · 107 KB
/
macsec.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* drivers/net/macsec.c - MACsec device
*
* Copyright (c) 2015 Sabrina Dubroca <sd@queasysnail.net>
*/
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/socket.h>
#include <linux/module.h>
#include <crypto/aead.h>
#include <linux/etherdevice.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/refcount.h>
#include <net/genetlink.h>
#include <net/sock.h>
#include <net/gro_cells.h>
#include <net/macsec.h>
#include <net/dst_metadata.h>
#include <linux/phy.h>
#include <linux/byteorder/generic.h>
#include <linux/if_arp.h>
#include <uapi/linux/if_macsec.h>
/* SecTAG length = macsec_eth_header without the optional SCI */
#define MACSEC_TAG_LEN 6
struct macsec_eth_header {
struct ethhdr eth;
/* SecTAG */
u8 tci_an;
#if defined(__LITTLE_ENDIAN_BITFIELD)
u8 short_length:6,
unused:2;
#elif defined(__BIG_ENDIAN_BITFIELD)
u8 unused:2,
short_length:6;
#else
#error "Please fix <asm/byteorder.h>"
#endif
__be32 packet_number;
u8 secure_channel_id[8]; /* optional */
} __packed;
/* minimum secure data length deemed "not short", see IEEE 802.1AE-2006 9.7 */
#define MIN_NON_SHORT_LEN 48
#define GCM_AES_IV_LEN 12
#define for_each_rxsc(secy, sc) \
for (sc = rcu_dereference_bh(secy->rx_sc); \
sc; \
sc = rcu_dereference_bh(sc->next))
#define for_each_rxsc_rtnl(secy, sc) \
for (sc = rtnl_dereference(secy->rx_sc); \
sc; \
sc = rtnl_dereference(sc->next))
#define pn_same_half(pn1, pn2) (!(((pn1) >> 31) ^ ((pn2) >> 31)))
struct gcm_iv_xpn {
union {
u8 short_secure_channel_id[4];
ssci_t ssci;
};
__be64 pn;
} __packed;
struct gcm_iv {
union {
u8 secure_channel_id[8];
sci_t sci;
};
__be32 pn;
};
#define MACSEC_VALIDATE_DEFAULT MACSEC_VALIDATE_STRICT
struct pcpu_secy_stats {
struct macsec_dev_stats stats;
struct u64_stats_sync syncp;
};
/**
* struct macsec_dev - private data
* @secy: SecY config
* @real_dev: pointer to underlying netdevice
* @dev_tracker: refcount tracker for @real_dev reference
* @stats: MACsec device stats
* @secys: linked list of SecY's on the underlying device
* @gro_cells: pointer to the Generic Receive Offload cell
* @offload: status of offloading on the MACsec device
*/
struct macsec_dev {
struct macsec_secy secy;
struct net_device *real_dev;
netdevice_tracker dev_tracker;
struct pcpu_secy_stats __percpu *stats;
struct list_head secys;
struct gro_cells gro_cells;
enum macsec_offload offload;
};
/**
* struct macsec_rxh_data - rx_handler private argument
* @secys: linked list of SecY's on this underlying device
*/
struct macsec_rxh_data {
struct list_head secys;
};
static struct macsec_dev *macsec_priv(const struct net_device *dev)
{
return (struct macsec_dev *)netdev_priv(dev);
}
static struct macsec_rxh_data *macsec_data_rcu(const struct net_device *dev)
{
return rcu_dereference_bh(dev->rx_handler_data);
}
static struct macsec_rxh_data *macsec_data_rtnl(const struct net_device *dev)
{
return rtnl_dereference(dev->rx_handler_data);
}
struct macsec_cb {
struct aead_request *req;
union {
struct macsec_tx_sa *tx_sa;
struct macsec_rx_sa *rx_sa;
};
u8 assoc_num;
bool valid;
bool has_sci;
};
static struct macsec_rx_sa *macsec_rxsa_get(struct macsec_rx_sa __rcu *ptr)
{
struct macsec_rx_sa *sa = rcu_dereference_bh(ptr);
if (!sa || !sa->active)
return NULL;
if (!refcount_inc_not_zero(&sa->refcnt))
return NULL;
return sa;
}
static struct macsec_rx_sa *macsec_active_rxsa_get(struct macsec_rx_sc *rx_sc)
{
struct macsec_rx_sa *sa = NULL;
int an;
for (an = 0; an < MACSEC_NUM_AN; an++) {
sa = macsec_rxsa_get(rx_sc->sa[an]);
if (sa)
break;
}
return sa;
}
static void free_rx_sc_rcu(struct rcu_head *head)
{
struct macsec_rx_sc *rx_sc = container_of(head, struct macsec_rx_sc, rcu_head);
free_percpu(rx_sc->stats);
kfree(rx_sc);
}
static struct macsec_rx_sc *macsec_rxsc_get(struct macsec_rx_sc *sc)
{
return refcount_inc_not_zero(&sc->refcnt) ? sc : NULL;
}
static void macsec_rxsc_put(struct macsec_rx_sc *sc)
{
if (refcount_dec_and_test(&sc->refcnt))
call_rcu(&sc->rcu_head, free_rx_sc_rcu);
}
static void free_rxsa(struct rcu_head *head)
{
struct macsec_rx_sa *sa = container_of(head, struct macsec_rx_sa, rcu);
crypto_free_aead(sa->key.tfm);
free_percpu(sa->stats);
kfree(sa);
}
static void macsec_rxsa_put(struct macsec_rx_sa *sa)
{
if (refcount_dec_and_test(&sa->refcnt))
call_rcu(&sa->rcu, free_rxsa);
}
static struct macsec_tx_sa *macsec_txsa_get(struct macsec_tx_sa __rcu *ptr)
{
struct macsec_tx_sa *sa = rcu_dereference_bh(ptr);
if (!sa || !sa->active)
return NULL;
if (!refcount_inc_not_zero(&sa->refcnt))
return NULL;
return sa;
}
static void free_txsa(struct rcu_head *head)
{
struct macsec_tx_sa *sa = container_of(head, struct macsec_tx_sa, rcu);
crypto_free_aead(sa->key.tfm);
free_percpu(sa->stats);
kfree(sa);
}
static void macsec_txsa_put(struct macsec_tx_sa *sa)
{
if (refcount_dec_and_test(&sa->refcnt))
call_rcu(&sa->rcu, free_txsa);
}
static struct macsec_cb *macsec_skb_cb(struct sk_buff *skb)
{
BUILD_BUG_ON(sizeof(struct macsec_cb) > sizeof(skb->cb));
return (struct macsec_cb *)skb->cb;
}
#define MACSEC_PORT_SCB (0x0000)
#define MACSEC_UNDEF_SCI ((__force sci_t)0xffffffffffffffffULL)
#define MACSEC_UNDEF_SSCI ((__force ssci_t)0xffffffff)
#define MACSEC_GCM_AES_128_SAK_LEN 16
#define MACSEC_GCM_AES_256_SAK_LEN 32
#define DEFAULT_SAK_LEN MACSEC_GCM_AES_128_SAK_LEN
#define DEFAULT_XPN false
#define DEFAULT_SEND_SCI true
#define DEFAULT_ENCRYPT false
#define DEFAULT_ENCODING_SA 0
#define MACSEC_XPN_MAX_REPLAY_WINDOW (((1 << 30) - 1))
static sci_t make_sci(const u8 *addr, __be16 port)
{
sci_t sci;
memcpy(&sci, addr, ETH_ALEN);
memcpy(((char *)&sci) + ETH_ALEN, &port, sizeof(port));
return sci;
}
static sci_t macsec_frame_sci(struct macsec_eth_header *hdr, bool sci_present)
{
sci_t sci;
if (sci_present)
memcpy(&sci, hdr->secure_channel_id,
sizeof(hdr->secure_channel_id));
else
sci = make_sci(hdr->eth.h_source, MACSEC_PORT_ES);
return sci;
}
static unsigned int macsec_sectag_len(bool sci_present)
{
return MACSEC_TAG_LEN + (sci_present ? MACSEC_SCI_LEN : 0);
}
static unsigned int macsec_hdr_len(bool sci_present)
{
return macsec_sectag_len(sci_present) + ETH_HLEN;
}
static unsigned int macsec_extra_len(bool sci_present)
{
return macsec_sectag_len(sci_present) + sizeof(__be16);
}
/* Fill SecTAG according to IEEE 802.1AE-2006 10.5.3 */
static void macsec_fill_sectag(struct macsec_eth_header *h,
const struct macsec_secy *secy, u32 pn,
bool sci_present)
{
const struct macsec_tx_sc *tx_sc = &secy->tx_sc;
memset(&h->tci_an, 0, macsec_sectag_len(sci_present));
h->eth.h_proto = htons(ETH_P_MACSEC);
if (sci_present) {
h->tci_an |= MACSEC_TCI_SC;
memcpy(&h->secure_channel_id, &secy->sci,
sizeof(h->secure_channel_id));
} else {
if (tx_sc->end_station)
h->tci_an |= MACSEC_TCI_ES;
if (tx_sc->scb)
h->tci_an |= MACSEC_TCI_SCB;
}
h->packet_number = htonl(pn);
/* with GCM, C/E clear for !encrypt, both set for encrypt */
if (tx_sc->encrypt)
h->tci_an |= MACSEC_TCI_CONFID;
else if (secy->icv_len != MACSEC_DEFAULT_ICV_LEN)
h->tci_an |= MACSEC_TCI_C;
h->tci_an |= tx_sc->encoding_sa;
}
static void macsec_set_shortlen(struct macsec_eth_header *h, size_t data_len)
{
if (data_len < MIN_NON_SHORT_LEN)
h->short_length = data_len;
}
/* Checks if a MACsec interface is being offloaded to an hardware engine */
static bool macsec_is_offloaded(struct macsec_dev *macsec)
{
if (macsec->offload == MACSEC_OFFLOAD_MAC ||
macsec->offload == MACSEC_OFFLOAD_PHY)
return true;
return false;
}
/* Checks if underlying layers implement MACsec offloading functions. */
static bool macsec_check_offload(enum macsec_offload offload,
struct macsec_dev *macsec)
{
if (!macsec || !macsec->real_dev)
return false;
if (offload == MACSEC_OFFLOAD_PHY)
return macsec->real_dev->phydev &&
macsec->real_dev->phydev->macsec_ops;
else if (offload == MACSEC_OFFLOAD_MAC)
return macsec->real_dev->features & NETIF_F_HW_MACSEC &&
macsec->real_dev->macsec_ops;
return false;
}
static const struct macsec_ops *__macsec_get_ops(enum macsec_offload offload,
struct macsec_dev *macsec,
struct macsec_context *ctx)
{
if (ctx) {
memset(ctx, 0, sizeof(*ctx));
ctx->offload = offload;
if (offload == MACSEC_OFFLOAD_PHY)
ctx->phydev = macsec->real_dev->phydev;
else if (offload == MACSEC_OFFLOAD_MAC)
ctx->netdev = macsec->real_dev;
}
if (offload == MACSEC_OFFLOAD_PHY)
return macsec->real_dev->phydev->macsec_ops;
else
return macsec->real_dev->macsec_ops;
}
/* Returns a pointer to the MACsec ops struct if any and updates the MACsec
* context device reference if provided.
*/
static const struct macsec_ops *macsec_get_ops(struct macsec_dev *macsec,
struct macsec_context *ctx)
{
if (!macsec_check_offload(macsec->offload, macsec))
return NULL;
return __macsec_get_ops(macsec->offload, macsec, ctx);
}
/* validate MACsec packet according to IEEE 802.1AE-2018 9.12 */
static bool macsec_validate_skb(struct sk_buff *skb, u16 icv_len, bool xpn)
{
struct macsec_eth_header *h = (struct macsec_eth_header *)skb->data;
int len = skb->len - 2 * ETH_ALEN;
int extra_len = macsec_extra_len(!!(h->tci_an & MACSEC_TCI_SC)) + icv_len;
/* a) It comprises at least 17 octets */
if (skb->len <= 16)
return false;
/* b) MACsec EtherType: already checked */
/* c) V bit is clear */
if (h->tci_an & MACSEC_TCI_VERSION)
return false;
/* d) ES or SCB => !SC */
if ((h->tci_an & MACSEC_TCI_ES || h->tci_an & MACSEC_TCI_SCB) &&
(h->tci_an & MACSEC_TCI_SC))
return false;
/* e) Bits 7 and 8 of octet 4 of the SecTAG are clear */
if (h->unused)
return false;
/* rx.pn != 0 if not XPN (figure 10-5 with 802.11AEbw-2013 amendment) */
if (!h->packet_number && !xpn)
return false;
/* length check, f) g) h) i) */
if (h->short_length)
return len == extra_len + h->short_length;
return len >= extra_len + MIN_NON_SHORT_LEN;
}
#define MACSEC_NEEDED_HEADROOM (macsec_extra_len(true))
#define MACSEC_NEEDED_TAILROOM MACSEC_STD_ICV_LEN
static void macsec_fill_iv_xpn(unsigned char *iv, ssci_t ssci, u64 pn,
salt_t salt)
{
struct gcm_iv_xpn *gcm_iv = (struct gcm_iv_xpn *)iv;
gcm_iv->ssci = ssci ^ salt.ssci;
gcm_iv->pn = cpu_to_be64(pn) ^ salt.pn;
}
static void macsec_fill_iv(unsigned char *iv, sci_t sci, u32 pn)
{
struct gcm_iv *gcm_iv = (struct gcm_iv *)iv;
gcm_iv->sci = sci;
gcm_iv->pn = htonl(pn);
}
static struct macsec_eth_header *macsec_ethhdr(struct sk_buff *skb)
{
return (struct macsec_eth_header *)skb_mac_header(skb);
}
static void __macsec_pn_wrapped(struct macsec_secy *secy,
struct macsec_tx_sa *tx_sa)
{
pr_debug("PN wrapped, transitioning to !oper\n");
tx_sa->active = false;
if (secy->protect_frames)
secy->operational = false;
}
void macsec_pn_wrapped(struct macsec_secy *secy, struct macsec_tx_sa *tx_sa)
{
spin_lock_bh(&tx_sa->lock);
__macsec_pn_wrapped(secy, tx_sa);
spin_unlock_bh(&tx_sa->lock);
}
EXPORT_SYMBOL_GPL(macsec_pn_wrapped);
static pn_t tx_sa_update_pn(struct macsec_tx_sa *tx_sa,
struct macsec_secy *secy)
{
pn_t pn;
spin_lock_bh(&tx_sa->lock);
pn = tx_sa->next_pn_halves;
if (secy->xpn)
tx_sa->next_pn++;
else
tx_sa->next_pn_halves.lower++;
if (tx_sa->next_pn == 0)
__macsec_pn_wrapped(secy, tx_sa);
spin_unlock_bh(&tx_sa->lock);
return pn;
}
static void macsec_encrypt_finish(struct sk_buff *skb, struct net_device *dev)
{
struct macsec_dev *macsec = netdev_priv(dev);
skb->dev = macsec->real_dev;
skb_reset_mac_header(skb);
skb->protocol = eth_hdr(skb)->h_proto;
}
static unsigned int macsec_msdu_len(struct sk_buff *skb)
{
struct macsec_dev *macsec = macsec_priv(skb->dev);
struct macsec_secy *secy = &macsec->secy;
bool sci_present = macsec_skb_cb(skb)->has_sci;
return skb->len - macsec_hdr_len(sci_present) - secy->icv_len;
}
static void macsec_count_tx(struct sk_buff *skb, struct macsec_tx_sc *tx_sc,
struct macsec_tx_sa *tx_sa)
{
unsigned int msdu_len = macsec_msdu_len(skb);
struct pcpu_tx_sc_stats *txsc_stats = this_cpu_ptr(tx_sc->stats);
u64_stats_update_begin(&txsc_stats->syncp);
if (tx_sc->encrypt) {
txsc_stats->stats.OutOctetsEncrypted += msdu_len;
txsc_stats->stats.OutPktsEncrypted++;
this_cpu_inc(tx_sa->stats->OutPktsEncrypted);
} else {
txsc_stats->stats.OutOctetsProtected += msdu_len;
txsc_stats->stats.OutPktsProtected++;
this_cpu_inc(tx_sa->stats->OutPktsProtected);
}
u64_stats_update_end(&txsc_stats->syncp);
}
static void count_tx(struct net_device *dev, int ret, int len)
{
if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
struct pcpu_sw_netstats *stats = this_cpu_ptr(dev->tstats);
u64_stats_update_begin(&stats->syncp);
u64_stats_inc(&stats->tx_packets);
u64_stats_add(&stats->tx_bytes, len);
u64_stats_update_end(&stats->syncp);
}
}
static void macsec_encrypt_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
struct net_device *dev = skb->dev;
struct macsec_dev *macsec = macsec_priv(dev);
struct macsec_tx_sa *sa = macsec_skb_cb(skb)->tx_sa;
int len, ret;
aead_request_free(macsec_skb_cb(skb)->req);
rcu_read_lock_bh();
macsec_count_tx(skb, &macsec->secy.tx_sc, macsec_skb_cb(skb)->tx_sa);
/* packet is encrypted/protected so tx_bytes must be calculated */
len = macsec_msdu_len(skb) + 2 * ETH_ALEN;
macsec_encrypt_finish(skb, dev);
ret = dev_queue_xmit(skb);
count_tx(dev, ret, len);
rcu_read_unlock_bh();
macsec_txsa_put(sa);
dev_put(dev);
}
static struct aead_request *macsec_alloc_req(struct crypto_aead *tfm,
unsigned char **iv,
struct scatterlist **sg,
int num_frags)
{
size_t size, iv_offset, sg_offset;
struct aead_request *req;
void *tmp;
size = sizeof(struct aead_request) + crypto_aead_reqsize(tfm);
iv_offset = size;
size += GCM_AES_IV_LEN;
size = ALIGN(size, __alignof__(struct scatterlist));
sg_offset = size;
size += sizeof(struct scatterlist) * num_frags;
tmp = kmalloc(size, GFP_ATOMIC);
if (!tmp)
return NULL;
*iv = (unsigned char *)(tmp + iv_offset);
*sg = (struct scatterlist *)(tmp + sg_offset);
req = tmp;
aead_request_set_tfm(req, tfm);
return req;
}
static struct sk_buff *macsec_encrypt(struct sk_buff *skb,
struct net_device *dev)
{
int ret;
struct scatterlist *sg;
struct sk_buff *trailer;
unsigned char *iv;
struct ethhdr *eth;
struct macsec_eth_header *hh;
size_t unprotected_len;
struct aead_request *req;
struct macsec_secy *secy;
struct macsec_tx_sc *tx_sc;
struct macsec_tx_sa *tx_sa;
struct macsec_dev *macsec = macsec_priv(dev);
bool sci_present;
pn_t pn;
secy = &macsec->secy;
tx_sc = &secy->tx_sc;
/* 10.5.1 TX SA assignment */
tx_sa = macsec_txsa_get(tx_sc->sa[tx_sc->encoding_sa]);
if (!tx_sa) {
secy->operational = false;
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
if (unlikely(skb_headroom(skb) < MACSEC_NEEDED_HEADROOM ||
skb_tailroom(skb) < MACSEC_NEEDED_TAILROOM)) {
struct sk_buff *nskb = skb_copy_expand(skb,
MACSEC_NEEDED_HEADROOM,
MACSEC_NEEDED_TAILROOM,
GFP_ATOMIC);
if (likely(nskb)) {
consume_skb(skb);
skb = nskb;
} else {
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(-ENOMEM);
}
} else {
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb) {
macsec_txsa_put(tx_sa);
return ERR_PTR(-ENOMEM);
}
}
unprotected_len = skb->len;
eth = eth_hdr(skb);
sci_present = macsec_send_sci(secy);
hh = skb_push(skb, macsec_extra_len(sci_present));
memmove(hh, eth, 2 * ETH_ALEN);
pn = tx_sa_update_pn(tx_sa, secy);
if (pn.full64 == 0) {
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(-ENOLINK);
}
macsec_fill_sectag(hh, secy, pn.lower, sci_present);
macsec_set_shortlen(hh, unprotected_len - 2 * ETH_ALEN);
skb_put(skb, secy->icv_len);
if (skb->len - ETH_HLEN > macsec_priv(dev)->real_dev->mtu) {
struct pcpu_secy_stats *secy_stats = this_cpu_ptr(macsec->stats);
u64_stats_update_begin(&secy_stats->syncp);
secy_stats->stats.OutPktsTooLong++;
u64_stats_update_end(&secy_stats->syncp);
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(-EINVAL);
}
ret = skb_cow_data(skb, 0, &trailer);
if (unlikely(ret < 0)) {
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(ret);
}
req = macsec_alloc_req(tx_sa->key.tfm, &iv, &sg, ret);
if (!req) {
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(-ENOMEM);
}
if (secy->xpn)
macsec_fill_iv_xpn(iv, tx_sa->ssci, pn.full64, tx_sa->key.salt);
else
macsec_fill_iv(iv, secy->sci, pn.lower);
sg_init_table(sg, ret);
ret = skb_to_sgvec(skb, sg, 0, skb->len);
if (unlikely(ret < 0)) {
aead_request_free(req);
macsec_txsa_put(tx_sa);
kfree_skb(skb);
return ERR_PTR(ret);
}
if (tx_sc->encrypt) {
int len = skb->len - macsec_hdr_len(sci_present) -
secy->icv_len;
aead_request_set_crypt(req, sg, sg, len, iv);
aead_request_set_ad(req, macsec_hdr_len(sci_present));
} else {
aead_request_set_crypt(req, sg, sg, 0, iv);
aead_request_set_ad(req, skb->len - secy->icv_len);
}
macsec_skb_cb(skb)->req = req;
macsec_skb_cb(skb)->tx_sa = tx_sa;
macsec_skb_cb(skb)->has_sci = sci_present;
aead_request_set_callback(req, 0, macsec_encrypt_done, skb);
dev_hold(skb->dev);
ret = crypto_aead_encrypt(req);
if (ret == -EINPROGRESS) {
return ERR_PTR(ret);
} else if (ret != 0) {
dev_put(skb->dev);
kfree_skb(skb);
aead_request_free(req);
macsec_txsa_put(tx_sa);
return ERR_PTR(-EINVAL);
}
dev_put(skb->dev);
aead_request_free(req);
macsec_txsa_put(tx_sa);
return skb;
}
static bool macsec_post_decrypt(struct sk_buff *skb, struct macsec_secy *secy, u32 pn)
{
struct macsec_rx_sa *rx_sa = macsec_skb_cb(skb)->rx_sa;
struct pcpu_rx_sc_stats *rxsc_stats = this_cpu_ptr(rx_sa->sc->stats);
struct macsec_eth_header *hdr = macsec_ethhdr(skb);
u32 lowest_pn = 0;
spin_lock(&rx_sa->lock);
if (rx_sa->next_pn_halves.lower >= secy->replay_window)
lowest_pn = rx_sa->next_pn_halves.lower - secy->replay_window;
/* Now perform replay protection check again
* (see IEEE 802.1AE-2006 figure 10-5)
*/
if (secy->replay_protect && pn < lowest_pn &&
(!secy->xpn || pn_same_half(pn, lowest_pn))) {
spin_unlock(&rx_sa->lock);
u64_stats_update_begin(&rxsc_stats->syncp);
rxsc_stats->stats.InPktsLate++;
u64_stats_update_end(&rxsc_stats->syncp);
DEV_STATS_INC(secy->netdev, rx_dropped);
return false;
}
if (secy->validate_frames != MACSEC_VALIDATE_DISABLED) {
unsigned int msdu_len = macsec_msdu_len(skb);
u64_stats_update_begin(&rxsc_stats->syncp);
if (hdr->tci_an & MACSEC_TCI_E)
rxsc_stats->stats.InOctetsDecrypted += msdu_len;
else
rxsc_stats->stats.InOctetsValidated += msdu_len;
u64_stats_update_end(&rxsc_stats->syncp);
}
if (!macsec_skb_cb(skb)->valid) {
spin_unlock(&rx_sa->lock);
/* 10.6.5 */
if (hdr->tci_an & MACSEC_TCI_C ||
secy->validate_frames == MACSEC_VALIDATE_STRICT) {
u64_stats_update_begin(&rxsc_stats->syncp);
rxsc_stats->stats.InPktsNotValid++;
u64_stats_update_end(&rxsc_stats->syncp);
this_cpu_inc(rx_sa->stats->InPktsNotValid);
DEV_STATS_INC(secy->netdev, rx_errors);
return false;
}
u64_stats_update_begin(&rxsc_stats->syncp);
if (secy->validate_frames == MACSEC_VALIDATE_CHECK) {
rxsc_stats->stats.InPktsInvalid++;
this_cpu_inc(rx_sa->stats->InPktsInvalid);
} else if (pn < lowest_pn) {
rxsc_stats->stats.InPktsDelayed++;
} else {
rxsc_stats->stats.InPktsUnchecked++;
}
u64_stats_update_end(&rxsc_stats->syncp);
} else {
u64_stats_update_begin(&rxsc_stats->syncp);
if (pn < lowest_pn) {
rxsc_stats->stats.InPktsDelayed++;
} else {
rxsc_stats->stats.InPktsOK++;
this_cpu_inc(rx_sa->stats->InPktsOK);
}
u64_stats_update_end(&rxsc_stats->syncp);
// Instead of "pn >=" - to support pn overflow in xpn
if (pn + 1 > rx_sa->next_pn_halves.lower) {
rx_sa->next_pn_halves.lower = pn + 1;
} else if (secy->xpn &&
!pn_same_half(pn, rx_sa->next_pn_halves.lower)) {
rx_sa->next_pn_halves.upper++;
rx_sa->next_pn_halves.lower = pn + 1;
}
spin_unlock(&rx_sa->lock);
}
return true;
}
static void macsec_reset_skb(struct sk_buff *skb, struct net_device *dev)
{
skb->pkt_type = PACKET_HOST;
skb->protocol = eth_type_trans(skb, dev);
skb_reset_network_header(skb);
if (!skb_transport_header_was_set(skb))
skb_reset_transport_header(skb);
skb_reset_mac_len(skb);
}
static void macsec_finalize_skb(struct sk_buff *skb, u8 icv_len, u8 hdr_len)
{
skb->ip_summed = CHECKSUM_NONE;
memmove(skb->data + hdr_len, skb->data, 2 * ETH_ALEN);
skb_pull(skb, hdr_len);
pskb_trim_unique(skb, skb->len - icv_len);
}
static void count_rx(struct net_device *dev, int len)
{
struct pcpu_sw_netstats *stats = this_cpu_ptr(dev->tstats);
u64_stats_update_begin(&stats->syncp);
u64_stats_inc(&stats->rx_packets);
u64_stats_add(&stats->rx_bytes, len);
u64_stats_update_end(&stats->syncp);
}
static void macsec_decrypt_done(struct crypto_async_request *base, int err)
{
struct sk_buff *skb = base->data;
struct net_device *dev = skb->dev;
struct macsec_dev *macsec = macsec_priv(dev);
struct macsec_rx_sa *rx_sa = macsec_skb_cb(skb)->rx_sa;
struct macsec_rx_sc *rx_sc = rx_sa->sc;
int len;
u32 pn;
aead_request_free(macsec_skb_cb(skb)->req);
if (!err)
macsec_skb_cb(skb)->valid = true;
rcu_read_lock_bh();
pn = ntohl(macsec_ethhdr(skb)->packet_number);
if (!macsec_post_decrypt(skb, &macsec->secy, pn)) {
rcu_read_unlock_bh();
kfree_skb(skb);
goto out;
}
macsec_finalize_skb(skb, macsec->secy.icv_len,
macsec_extra_len(macsec_skb_cb(skb)->has_sci));
len = skb->len;
macsec_reset_skb(skb, macsec->secy.netdev);
if (gro_cells_receive(&macsec->gro_cells, skb) == NET_RX_SUCCESS)
count_rx(dev, len);
rcu_read_unlock_bh();
out:
macsec_rxsa_put(rx_sa);
macsec_rxsc_put(rx_sc);
dev_put(dev);
}
static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
struct net_device *dev,
struct macsec_rx_sa *rx_sa,
sci_t sci,
struct macsec_secy *secy)
{
int ret;
struct scatterlist *sg;
struct sk_buff *trailer;
unsigned char *iv;
struct aead_request *req;
struct macsec_eth_header *hdr;
u32 hdr_pn;
u16 icv_len = secy->icv_len;
macsec_skb_cb(skb)->valid = false;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
return ERR_PTR(-ENOMEM);
ret = skb_cow_data(skb, 0, &trailer);
if (unlikely(ret < 0)) {
kfree_skb(skb);
return ERR_PTR(ret);
}
req = macsec_alloc_req(rx_sa->key.tfm, &iv, &sg, ret);
if (!req) {
kfree_skb(skb);
return ERR_PTR(-ENOMEM);
}
hdr = (struct macsec_eth_header *)skb->data;
hdr_pn = ntohl(hdr->packet_number);
if (secy->xpn) {
pn_t recovered_pn = rx_sa->next_pn_halves;
recovered_pn.lower = hdr_pn;
if (hdr_pn < rx_sa->next_pn_halves.lower &&
!pn_same_half(hdr_pn, rx_sa->next_pn_halves.lower))
recovered_pn.upper++;
macsec_fill_iv_xpn(iv, rx_sa->ssci, recovered_pn.full64,
rx_sa->key.salt);
} else {
macsec_fill_iv(iv, sci, hdr_pn);
}
sg_init_table(sg, ret);
ret = skb_to_sgvec(skb, sg, 0, skb->len);
if (unlikely(ret < 0)) {
aead_request_free(req);
kfree_skb(skb);
return ERR_PTR(ret);
}
if (hdr->tci_an & MACSEC_TCI_E) {
/* confidentiality: ethernet + macsec header
* authenticated, encrypted payload
*/
int len = skb->len - macsec_hdr_len(macsec_skb_cb(skb)->has_sci);
aead_request_set_crypt(req, sg, sg, len, iv);
aead_request_set_ad(req, macsec_hdr_len(macsec_skb_cb(skb)->has_sci));
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb) {
aead_request_free(req);
return ERR_PTR(-ENOMEM);
}
} else {
/* integrity only: all headers + data authenticated */
aead_request_set_crypt(req, sg, sg, icv_len, iv);
aead_request_set_ad(req, skb->len - icv_len);
}
macsec_skb_cb(skb)->req = req;
skb->dev = dev;
aead_request_set_callback(req, 0, macsec_decrypt_done, skb);
dev_hold(dev);
ret = crypto_aead_decrypt(req);
if (ret == -EINPROGRESS) {
return ERR_PTR(ret);
} else if (ret != 0) {
/* decryption/authentication failed
* 10.6 if validateFrames is disabled, deliver anyway
*/
if (ret != -EBADMSG) {
kfree_skb(skb);
skb = ERR_PTR(ret);
}
} else {
macsec_skb_cb(skb)->valid = true;
}
dev_put(dev);
aead_request_free(req);
return skb;
}
static struct macsec_rx_sc *find_rx_sc(struct macsec_secy *secy, sci_t sci)
{
struct macsec_rx_sc *rx_sc;
for_each_rxsc(secy, rx_sc) {
if (rx_sc->sci == sci)
return rx_sc;
}
return NULL;
}
static struct macsec_rx_sc *find_rx_sc_rtnl(struct macsec_secy *secy, sci_t sci)
{
struct macsec_rx_sc *rx_sc;
for_each_rxsc_rtnl(secy, rx_sc) {
if (rx_sc->sci == sci)
return rx_sc;
}
return NULL;
}