forked from microsoft/WSL2-Linux-Kernel
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathamt.c
3453 lines (3078 loc) · 88.9 KB
/
amt.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
/* Copyright (c) 2021 Taehee Yoo <ap420073@gmail.com> */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/jhash.h>
#include <linux/if_tunnel.h>
#include <linux/net.h>
#include <linux/igmp.h>
#include <linux/workqueue.h>
#include <net/sch_generic.h>
#include <net/net_namespace.h>
#include <net/ip.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/icmp.h>
#include <net/mld.h>
#include <net/amt.h>
#include <uapi/linux/amt.h>
#include <linux/security.h>
#include <net/gro_cells.h>
#include <net/ipv6.h>
#include <net/if_inet6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>
#include <net/inet_common.h>
#include <net/ip6_checksum.h>
static struct workqueue_struct *amt_wq;
static HLIST_HEAD(source_gc_list);
/* Lock for source_gc_list */
static spinlock_t source_gc_lock;
static struct delayed_work source_gc_wq;
static char *status_str[] = {
"AMT_STATUS_INIT",
"AMT_STATUS_SENT_DISCOVERY",
"AMT_STATUS_RECEIVED_DISCOVERY",
"AMT_STATUS_SENT_ADVERTISEMENT",
"AMT_STATUS_RECEIVED_ADVERTISEMENT",
"AMT_STATUS_SENT_REQUEST",
"AMT_STATUS_RECEIVED_REQUEST",
"AMT_STATUS_SENT_QUERY",
"AMT_STATUS_RECEIVED_QUERY",
"AMT_STATUS_SENT_UPDATE",
"AMT_STATUS_RECEIVED_UPDATE",
};
static char *type_str[] = {
"", /* Type 0 is not defined */
"AMT_MSG_DISCOVERY",
"AMT_MSG_ADVERTISEMENT",
"AMT_MSG_REQUEST",
"AMT_MSG_MEMBERSHIP_QUERY",
"AMT_MSG_MEMBERSHIP_UPDATE",
"AMT_MSG_MULTICAST_DATA",
"AMT_MSG_TEARDOWN",
};
static char *action_str[] = {
"AMT_ACT_GMI",
"AMT_ACT_GMI_ZERO",
"AMT_ACT_GT",
"AMT_ACT_STATUS_FWD_NEW",
"AMT_ACT_STATUS_D_FWD_NEW",
"AMT_ACT_STATUS_NONE_NEW",
};
static struct igmpv3_grec igmpv3_zero_grec;
#if IS_ENABLED(CONFIG_IPV6)
#define MLD2_ALL_NODE_INIT { { { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x01 } } }
static struct in6_addr mld2_all_node = MLD2_ALL_NODE_INIT;
static struct mld2_grec mldv2_zero_grec;
#endif
static struct amt_skb_cb *amt_skb_cb(struct sk_buff *skb)
{
BUILD_BUG_ON(sizeof(struct amt_skb_cb) + sizeof(struct qdisc_skb_cb) >
sizeof_field(struct sk_buff, cb));
return (struct amt_skb_cb *)((void *)skb->cb +
sizeof(struct qdisc_skb_cb));
}
static void __amt_source_gc_work(void)
{
struct amt_source_node *snode;
struct hlist_head gc_list;
struct hlist_node *t;
spin_lock_bh(&source_gc_lock);
hlist_move_list(&source_gc_list, &gc_list);
spin_unlock_bh(&source_gc_lock);
hlist_for_each_entry_safe(snode, t, &gc_list, node) {
hlist_del_rcu(&snode->node);
kfree_rcu(snode, rcu);
}
}
static void amt_source_gc_work(struct work_struct *work)
{
__amt_source_gc_work();
spin_lock_bh(&source_gc_lock);
mod_delayed_work(amt_wq, &source_gc_wq,
msecs_to_jiffies(AMT_GC_INTERVAL));
spin_unlock_bh(&source_gc_lock);
}
static bool amt_addr_equal(union amt_addr *a, union amt_addr *b)
{
return !memcmp(a, b, sizeof(union amt_addr));
}
static u32 amt_source_hash(struct amt_tunnel_list *tunnel, union amt_addr *src)
{
u32 hash = jhash(src, sizeof(*src), tunnel->amt->hash_seed);
return reciprocal_scale(hash, tunnel->amt->hash_buckets);
}
static bool amt_status_filter(struct amt_source_node *snode,
enum amt_filter filter)
{
bool rc = false;
switch (filter) {
case AMT_FILTER_FWD:
if (snode->status == AMT_SOURCE_STATUS_FWD &&
snode->flags == AMT_SOURCE_OLD)
rc = true;
break;
case AMT_FILTER_D_FWD:
if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
snode->flags == AMT_SOURCE_OLD)
rc = true;
break;
case AMT_FILTER_FWD_NEW:
if (snode->status == AMT_SOURCE_STATUS_FWD &&
snode->flags == AMT_SOURCE_NEW)
rc = true;
break;
case AMT_FILTER_D_FWD_NEW:
if (snode->status == AMT_SOURCE_STATUS_D_FWD &&
snode->flags == AMT_SOURCE_NEW)
rc = true;
break;
case AMT_FILTER_ALL:
rc = true;
break;
case AMT_FILTER_NONE_NEW:
if (snode->status == AMT_SOURCE_STATUS_NONE &&
snode->flags == AMT_SOURCE_NEW)
rc = true;
break;
case AMT_FILTER_BOTH:
if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
snode->status == AMT_SOURCE_STATUS_FWD) &&
snode->flags == AMT_SOURCE_OLD)
rc = true;
break;
case AMT_FILTER_BOTH_NEW:
if ((snode->status == AMT_SOURCE_STATUS_D_FWD ||
snode->status == AMT_SOURCE_STATUS_FWD) &&
snode->flags == AMT_SOURCE_NEW)
rc = true;
break;
default:
WARN_ON_ONCE(1);
break;
}
return rc;
}
static struct amt_source_node *amt_lookup_src(struct amt_tunnel_list *tunnel,
struct amt_group_node *gnode,
enum amt_filter filter,
union amt_addr *src)
{
u32 hash = amt_source_hash(tunnel, src);
struct amt_source_node *snode;
hlist_for_each_entry_rcu(snode, &gnode->sources[hash], node)
if (amt_status_filter(snode, filter) &&
amt_addr_equal(&snode->source_addr, src))
return snode;
return NULL;
}
static u32 amt_group_hash(struct amt_tunnel_list *tunnel, union amt_addr *group)
{
u32 hash = jhash(group, sizeof(*group), tunnel->amt->hash_seed);
return reciprocal_scale(hash, tunnel->amt->hash_buckets);
}
static struct amt_group_node *amt_lookup_group(struct amt_tunnel_list *tunnel,
union amt_addr *group,
union amt_addr *host,
bool v6)
{
u32 hash = amt_group_hash(tunnel, group);
struct amt_group_node *gnode;
hlist_for_each_entry_rcu(gnode, &tunnel->groups[hash], node) {
if (amt_addr_equal(&gnode->group_addr, group) &&
amt_addr_equal(&gnode->host_addr, host) &&
gnode->v6 == v6)
return gnode;
}
return NULL;
}
static void amt_destroy_source(struct amt_source_node *snode)
{
struct amt_group_node *gnode = snode->gnode;
struct amt_tunnel_list *tunnel;
tunnel = gnode->tunnel_list;
if (!gnode->v6) {
netdev_dbg(snode->gnode->amt->dev,
"Delete source %pI4 from %pI4\n",
&snode->source_addr.ip4,
&gnode->group_addr.ip4);
#if IS_ENABLED(CONFIG_IPV6)
} else {
netdev_dbg(snode->gnode->amt->dev,
"Delete source %pI6 from %pI6\n",
&snode->source_addr.ip6,
&gnode->group_addr.ip6);
#endif
}
cancel_delayed_work(&snode->source_timer);
hlist_del_init_rcu(&snode->node);
tunnel->nr_sources--;
gnode->nr_sources--;
spin_lock_bh(&source_gc_lock);
hlist_add_head_rcu(&snode->node, &source_gc_list);
spin_unlock_bh(&source_gc_lock);
}
static void amt_del_group(struct amt_dev *amt, struct amt_group_node *gnode)
{
struct amt_source_node *snode;
struct hlist_node *t;
int i;
if (cancel_delayed_work(&gnode->group_timer))
dev_put(amt->dev);
hlist_del_rcu(&gnode->node);
gnode->tunnel_list->nr_groups--;
if (!gnode->v6)
netdev_dbg(amt->dev, "Leave group %pI4\n",
&gnode->group_addr.ip4);
#if IS_ENABLED(CONFIG_IPV6)
else
netdev_dbg(amt->dev, "Leave group %pI6\n",
&gnode->group_addr.ip6);
#endif
for (i = 0; i < amt->hash_buckets; i++)
hlist_for_each_entry_safe(snode, t, &gnode->sources[i], node)
amt_destroy_source(snode);
/* tunnel->lock was acquired outside of amt_del_group()
* But rcu_read_lock() was acquired too so It's safe.
*/
kfree_rcu(gnode, rcu);
}
/* If a source timer expires with a router filter-mode for the group of
* INCLUDE, the router concludes that traffic from this particular
* source is no longer desired on the attached network, and deletes the
* associated source record.
*/
static void amt_source_work(struct work_struct *work)
{
struct amt_source_node *snode = container_of(to_delayed_work(work),
struct amt_source_node,
source_timer);
struct amt_group_node *gnode = snode->gnode;
struct amt_dev *amt = gnode->amt;
struct amt_tunnel_list *tunnel;
tunnel = gnode->tunnel_list;
spin_lock_bh(&tunnel->lock);
rcu_read_lock();
if (gnode->filter_mode == MCAST_INCLUDE) {
amt_destroy_source(snode);
if (!gnode->nr_sources)
amt_del_group(amt, gnode);
} else {
/* When a router filter-mode for a group is EXCLUDE,
* source records are only deleted when the group timer expires
*/
snode->status = AMT_SOURCE_STATUS_D_FWD;
}
rcu_read_unlock();
spin_unlock_bh(&tunnel->lock);
}
static void amt_act_src(struct amt_tunnel_list *tunnel,
struct amt_group_node *gnode,
struct amt_source_node *snode,
enum amt_act act)
{
struct amt_dev *amt = tunnel->amt;
switch (act) {
case AMT_ACT_GMI:
mod_delayed_work(amt_wq, &snode->source_timer,
msecs_to_jiffies(amt_gmi(amt)));
break;
case AMT_ACT_GMI_ZERO:
cancel_delayed_work(&snode->source_timer);
break;
case AMT_ACT_GT:
mod_delayed_work(amt_wq, &snode->source_timer,
gnode->group_timer.timer.expires);
break;
case AMT_ACT_STATUS_FWD_NEW:
snode->status = AMT_SOURCE_STATUS_FWD;
snode->flags = AMT_SOURCE_NEW;
break;
case AMT_ACT_STATUS_D_FWD_NEW:
snode->status = AMT_SOURCE_STATUS_D_FWD;
snode->flags = AMT_SOURCE_NEW;
break;
case AMT_ACT_STATUS_NONE_NEW:
cancel_delayed_work(&snode->source_timer);
snode->status = AMT_SOURCE_STATUS_NONE;
snode->flags = AMT_SOURCE_NEW;
break;
default:
WARN_ON_ONCE(1);
return;
}
if (!gnode->v6)
netdev_dbg(amt->dev, "Source %pI4 from %pI4 Acted %s\n",
&snode->source_addr.ip4,
&gnode->group_addr.ip4,
action_str[act]);
#if IS_ENABLED(CONFIG_IPV6)
else
netdev_dbg(amt->dev, "Source %pI6 from %pI6 Acted %s\n",
&snode->source_addr.ip6,
&gnode->group_addr.ip6,
action_str[act]);
#endif
}
static struct amt_source_node *amt_alloc_snode(struct amt_group_node *gnode,
union amt_addr *src)
{
struct amt_source_node *snode;
snode = kzalloc(sizeof(*snode), GFP_ATOMIC);
if (!snode)
return NULL;
memcpy(&snode->source_addr, src, sizeof(union amt_addr));
snode->gnode = gnode;
snode->status = AMT_SOURCE_STATUS_NONE;
snode->flags = AMT_SOURCE_NEW;
INIT_HLIST_NODE(&snode->node);
INIT_DELAYED_WORK(&snode->source_timer, amt_source_work);
return snode;
}
/* RFC 3810 - 7.2.2. Definition of Filter Timers
*
* Router Mode Filter Timer Actions/Comments
* ----------- ----------------- ----------------
*
* INCLUDE Not Used All listeners in
* INCLUDE mode.
*
* EXCLUDE Timer > 0 At least one listener
* in EXCLUDE mode.
*
* EXCLUDE Timer == 0 No more listeners in
* EXCLUDE mode for the
* multicast address.
* If the Requested List
* is empty, delete
* Multicast Address
* Record. If not, switch
* to INCLUDE filter mode;
* the sources in the
* Requested List are
* moved to the Include
* List, and the Exclude
* List is deleted.
*/
static void amt_group_work(struct work_struct *work)
{
struct amt_group_node *gnode = container_of(to_delayed_work(work),
struct amt_group_node,
group_timer);
struct amt_tunnel_list *tunnel = gnode->tunnel_list;
struct amt_dev *amt = gnode->amt;
struct amt_source_node *snode;
bool delete_group = true;
struct hlist_node *t;
int i, buckets;
buckets = amt->hash_buckets;
spin_lock_bh(&tunnel->lock);
if (gnode->filter_mode == MCAST_INCLUDE) {
/* Not Used */
spin_unlock_bh(&tunnel->lock);
goto out;
}
rcu_read_lock();
for (i = 0; i < buckets; i++) {
hlist_for_each_entry_safe(snode, t,
&gnode->sources[i], node) {
if (!delayed_work_pending(&snode->source_timer) ||
snode->status == AMT_SOURCE_STATUS_D_FWD) {
amt_destroy_source(snode);
} else {
delete_group = false;
snode->status = AMT_SOURCE_STATUS_FWD;
}
}
}
if (delete_group)
amt_del_group(amt, gnode);
else
gnode->filter_mode = MCAST_INCLUDE;
rcu_read_unlock();
spin_unlock_bh(&tunnel->lock);
out:
dev_put(amt->dev);
}
/* Non-existent group is created as INCLUDE {empty}:
*
* RFC 3376 - 5.1. Action on Change of Interface State
*
* If no interface state existed for that multicast address before
* the change (i.e., the change consisted of creating a new
* per-interface record), or if no state exists after the change
* (i.e., the change consisted of deleting a per-interface record),
* then the "non-existent" state is considered to have a filter mode
* of INCLUDE and an empty source list.
*/
static struct amt_group_node *amt_add_group(struct amt_dev *amt,
struct amt_tunnel_list *tunnel,
union amt_addr *group,
union amt_addr *host,
bool v6)
{
struct amt_group_node *gnode;
u32 hash;
int i;
if (tunnel->nr_groups >= amt->max_groups)
return ERR_PTR(-ENOSPC);
gnode = kzalloc(sizeof(*gnode) +
(sizeof(struct hlist_head) * amt->hash_buckets),
GFP_ATOMIC);
if (unlikely(!gnode))
return ERR_PTR(-ENOMEM);
gnode->amt = amt;
gnode->group_addr = *group;
gnode->host_addr = *host;
gnode->v6 = v6;
gnode->tunnel_list = tunnel;
gnode->filter_mode = MCAST_INCLUDE;
INIT_HLIST_NODE(&gnode->node);
INIT_DELAYED_WORK(&gnode->group_timer, amt_group_work);
for (i = 0; i < amt->hash_buckets; i++)
INIT_HLIST_HEAD(&gnode->sources[i]);
hash = amt_group_hash(tunnel, group);
hlist_add_head_rcu(&gnode->node, &tunnel->groups[hash]);
tunnel->nr_groups++;
if (!gnode->v6)
netdev_dbg(amt->dev, "Join group %pI4\n",
&gnode->group_addr.ip4);
#if IS_ENABLED(CONFIG_IPV6)
else
netdev_dbg(amt->dev, "Join group %pI6\n",
&gnode->group_addr.ip6);
#endif
return gnode;
}
static struct sk_buff *amt_build_igmp_gq(struct amt_dev *amt)
{
u8 ra[AMT_IPHDR_OPTS] = { IPOPT_RA, 4, 0, 0 };
int hlen = LL_RESERVED_SPACE(amt->dev);
int tlen = amt->dev->needed_tailroom;
struct igmpv3_query *ihv3;
void *csum_start = NULL;
__sum16 *csum = NULL;
struct sk_buff *skb;
struct ethhdr *eth;
struct iphdr *iph;
unsigned int len;
int offset;
len = hlen + tlen + sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3);
skb = netdev_alloc_skb_ip_align(amt->dev, len);
if (!skb)
return NULL;
skb_reserve(skb, hlen);
skb_push(skb, sizeof(*eth));
skb->protocol = htons(ETH_P_IP);
skb_reset_mac_header(skb);
skb->priority = TC_PRIO_CONTROL;
skb_put(skb, sizeof(*iph));
skb_put_data(skb, ra, sizeof(ra));
skb_put(skb, sizeof(*ihv3));
skb_pull(skb, sizeof(*eth));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = (sizeof(struct iphdr) + AMT_IPHDR_OPTS) >> 2;
iph->tos = AMT_TOS;
iph->tot_len = htons(sizeof(*iph) + AMT_IPHDR_OPTS + sizeof(*ihv3));
iph->frag_off = htons(IP_DF);
iph->ttl = 1;
iph->id = 0;
iph->protocol = IPPROTO_IGMP;
iph->daddr = htonl(INADDR_ALLHOSTS_GROUP);
iph->saddr = htonl(INADDR_ANY);
ip_send_check(iph);
eth = eth_hdr(skb);
ether_addr_copy(eth->h_source, amt->dev->dev_addr);
ip_eth_mc_map(htonl(INADDR_ALLHOSTS_GROUP), eth->h_dest);
eth->h_proto = htons(ETH_P_IP);
ihv3 = skb_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS);
skb_reset_transport_header(skb);
ihv3->type = IGMP_HOST_MEMBERSHIP_QUERY;
ihv3->code = 1;
ihv3->group = 0;
ihv3->qqic = amt->qi;
ihv3->nsrcs = 0;
ihv3->resv = 0;
ihv3->suppress = false;
ihv3->qrv = READ_ONCE(amt->net->ipv4.sysctl_igmp_qrv);
ihv3->csum = 0;
csum = &ihv3->csum;
csum_start = (void *)ihv3;
*csum = ip_compute_csum(csum_start, sizeof(*ihv3));
offset = skb_transport_offset(skb);
skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
skb->ip_summed = CHECKSUM_NONE;
skb_push(skb, sizeof(*eth) + sizeof(*iph) + AMT_IPHDR_OPTS);
return skb;
}
static void amt_update_gw_status(struct amt_dev *amt, enum amt_status status,
bool validate)
{
if (validate && amt->status >= status)
return;
netdev_dbg(amt->dev, "Update GW status %s -> %s",
status_str[amt->status], status_str[status]);
WRITE_ONCE(amt->status, status);
}
static void __amt_update_relay_status(struct amt_tunnel_list *tunnel,
enum amt_status status,
bool validate)
{
if (validate && tunnel->status >= status)
return;
netdev_dbg(tunnel->amt->dev,
"Update Tunnel(IP = %pI4, PORT = %u) status %s -> %s",
&tunnel->ip4, ntohs(tunnel->source_port),
status_str[tunnel->status], status_str[status]);
tunnel->status = status;
}
static void amt_update_relay_status(struct amt_tunnel_list *tunnel,
enum amt_status status, bool validate)
{
spin_lock_bh(&tunnel->lock);
__amt_update_relay_status(tunnel, status, validate);
spin_unlock_bh(&tunnel->lock);
}
static void amt_send_discovery(struct amt_dev *amt)
{
struct amt_header_discovery *amtd;
int hlen, tlen, offset;
struct socket *sock;
struct udphdr *udph;
struct sk_buff *skb;
struct iphdr *iph;
struct rtable *rt;
struct flowi4 fl4;
u32 len;
int err;
rcu_read_lock();
sock = rcu_dereference(amt->sock);
if (!sock)
goto out;
if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
goto out;
rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
amt->discovery_ip, amt->local_ip,
amt->gw_port, amt->relay_port,
IPPROTO_UDP, 0,
amt->stream_dev->ifindex);
if (IS_ERR(rt)) {
amt->dev->stats.tx_errors++;
goto out;
}
hlen = LL_RESERVED_SPACE(amt->dev);
tlen = amt->dev->needed_tailroom;
len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
skb = netdev_alloc_skb_ip_align(amt->dev, len);
if (!skb) {
ip_rt_put(rt);
amt->dev->stats.tx_errors++;
goto out;
}
skb->priority = TC_PRIO_CONTROL;
skb_dst_set(skb, &rt->dst);
len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtd);
skb_reset_network_header(skb);
skb_put(skb, len);
amtd = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
amtd->version = 0;
amtd->type = AMT_MSG_DISCOVERY;
amtd->reserved = 0;
amtd->nonce = amt->nonce;
skb_push(skb, sizeof(*udph));
skb_reset_transport_header(skb);
udph = udp_hdr(skb);
udph->source = amt->gw_port;
udph->dest = amt->relay_port;
udph->len = htons(sizeof(*udph) + sizeof(*amtd));
udph->check = 0;
offset = skb_transport_offset(skb);
skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
udph->check = csum_tcpudp_magic(amt->local_ip, amt->discovery_ip,
sizeof(*udph) + sizeof(*amtd),
IPPROTO_UDP, skb->csum);
skb_push(skb, sizeof(*iph));
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = (sizeof(struct iphdr)) >> 2;
iph->tos = AMT_TOS;
iph->frag_off = 0;
iph->ttl = ip4_dst_hoplimit(&rt->dst);
iph->daddr = amt->discovery_ip;
iph->saddr = amt->local_ip;
iph->protocol = IPPROTO_UDP;
iph->tot_len = htons(len);
skb->ip_summed = CHECKSUM_NONE;
ip_select_ident(amt->net, skb, NULL);
ip_send_check(iph);
err = ip_local_out(amt->net, sock->sk, skb);
if (unlikely(net_xmit_eval(err)))
amt->dev->stats.tx_errors++;
amt_update_gw_status(amt, AMT_STATUS_SENT_DISCOVERY, true);
out:
rcu_read_unlock();
}
static void amt_send_request(struct amt_dev *amt, bool v6)
{
struct amt_header_request *amtrh;
int hlen, tlen, offset;
struct socket *sock;
struct udphdr *udph;
struct sk_buff *skb;
struct iphdr *iph;
struct rtable *rt;
struct flowi4 fl4;
u32 len;
int err;
rcu_read_lock();
sock = rcu_dereference(amt->sock);
if (!sock)
goto out;
if (!netif_running(amt->stream_dev) || !netif_running(amt->dev))
goto out;
rt = ip_route_output_ports(amt->net, &fl4, sock->sk,
amt->remote_ip, amt->local_ip,
amt->gw_port, amt->relay_port,
IPPROTO_UDP, 0,
amt->stream_dev->ifindex);
if (IS_ERR(rt)) {
amt->dev->stats.tx_errors++;
goto out;
}
hlen = LL_RESERVED_SPACE(amt->dev);
tlen = amt->dev->needed_tailroom;
len = hlen + tlen + sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
skb = netdev_alloc_skb_ip_align(amt->dev, len);
if (!skb) {
ip_rt_put(rt);
amt->dev->stats.tx_errors++;
goto out;
}
skb->priority = TC_PRIO_CONTROL;
skb_dst_set(skb, &rt->dst);
len = sizeof(*iph) + sizeof(*udph) + sizeof(*amtrh);
skb_reset_network_header(skb);
skb_put(skb, len);
amtrh = skb_pull(skb, sizeof(*iph) + sizeof(*udph));
amtrh->version = 0;
amtrh->type = AMT_MSG_REQUEST;
amtrh->reserved1 = 0;
amtrh->p = v6;
amtrh->reserved2 = 0;
amtrh->nonce = amt->nonce;
skb_push(skb, sizeof(*udph));
skb_reset_transport_header(skb);
udph = udp_hdr(skb);
udph->source = amt->gw_port;
udph->dest = amt->relay_port;
udph->len = htons(sizeof(*amtrh) + sizeof(*udph));
udph->check = 0;
offset = skb_transport_offset(skb);
skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
udph->check = csum_tcpudp_magic(amt->local_ip, amt->remote_ip,
sizeof(*udph) + sizeof(*amtrh),
IPPROTO_UDP, skb->csum);
skb_push(skb, sizeof(*iph));
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = (sizeof(struct iphdr)) >> 2;
iph->tos = AMT_TOS;
iph->frag_off = 0;
iph->ttl = ip4_dst_hoplimit(&rt->dst);
iph->daddr = amt->remote_ip;
iph->saddr = amt->local_ip;
iph->protocol = IPPROTO_UDP;
iph->tot_len = htons(len);
skb->ip_summed = CHECKSUM_NONE;
ip_select_ident(amt->net, skb, NULL);
ip_send_check(iph);
err = ip_local_out(amt->net, sock->sk, skb);
if (unlikely(net_xmit_eval(err)))
amt->dev->stats.tx_errors++;
out:
rcu_read_unlock();
}
static void amt_send_igmp_gq(struct amt_dev *amt,
struct amt_tunnel_list *tunnel)
{
struct sk_buff *skb;
skb = amt_build_igmp_gq(amt);
if (!skb)
return;
amt_skb_cb(skb)->tunnel = tunnel;
dev_queue_xmit(skb);
}
#if IS_ENABLED(CONFIG_IPV6)
static struct sk_buff *amt_build_mld_gq(struct amt_dev *amt)
{
u8 ra[AMT_IP6HDR_OPTS] = { IPPROTO_ICMPV6, 0, IPV6_TLV_ROUTERALERT,
2, 0, 0, IPV6_TLV_PAD1, IPV6_TLV_PAD1 };
int hlen = LL_RESERVED_SPACE(amt->dev);
int tlen = amt->dev->needed_tailroom;
struct mld2_query *mld2q;
void *csum_start = NULL;
struct ipv6hdr *ip6h;
struct sk_buff *skb;
struct ethhdr *eth;
u32 len;
len = hlen + tlen + sizeof(*ip6h) + sizeof(ra) + sizeof(*mld2q);
skb = netdev_alloc_skb_ip_align(amt->dev, len);
if (!skb)
return NULL;
skb_reserve(skb, hlen);
skb_push(skb, sizeof(*eth));
skb_reset_mac_header(skb);
eth = eth_hdr(skb);
skb->priority = TC_PRIO_CONTROL;
skb->protocol = htons(ETH_P_IPV6);
skb_put_zero(skb, sizeof(*ip6h));
skb_put_data(skb, ra, sizeof(ra));
skb_put_zero(skb, sizeof(*mld2q));
skb_pull(skb, sizeof(*eth));
skb_reset_network_header(skb);
ip6h = ipv6_hdr(skb);
ip6h->payload_len = htons(sizeof(ra) + sizeof(*mld2q));
ip6h->nexthdr = NEXTHDR_HOP;
ip6h->hop_limit = 1;
ip6h->daddr = mld2_all_node;
ip6_flow_hdr(ip6h, 0, 0);
if (ipv6_dev_get_saddr(amt->net, amt->dev, &ip6h->daddr, 0,
&ip6h->saddr)) {
amt->dev->stats.tx_errors++;
kfree_skb(skb);
return NULL;
}
eth->h_proto = htons(ETH_P_IPV6);
ether_addr_copy(eth->h_source, amt->dev->dev_addr);
ipv6_eth_mc_map(&mld2_all_node, eth->h_dest);
skb_pull(skb, sizeof(*ip6h) + sizeof(ra));
skb_reset_transport_header(skb);
mld2q = (struct mld2_query *)icmp6_hdr(skb);
mld2q->mld2q_mrc = htons(1);
mld2q->mld2q_type = ICMPV6_MGM_QUERY;
mld2q->mld2q_code = 0;
mld2q->mld2q_cksum = 0;
mld2q->mld2q_resv1 = 0;
mld2q->mld2q_resv2 = 0;
mld2q->mld2q_suppress = 0;
mld2q->mld2q_qrv = amt->qrv;
mld2q->mld2q_nsrcs = 0;
mld2q->mld2q_qqic = amt->qi;
csum_start = (void *)mld2q;
mld2q->mld2q_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
sizeof(*mld2q),
IPPROTO_ICMPV6,
csum_partial(csum_start,
sizeof(*mld2q), 0));
skb->ip_summed = CHECKSUM_NONE;
skb_push(skb, sizeof(*eth) + sizeof(*ip6h) + sizeof(ra));
return skb;
}
static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
{
struct sk_buff *skb;
skb = amt_build_mld_gq(amt);
if (!skb)
return;
amt_skb_cb(skb)->tunnel = tunnel;
dev_queue_xmit(skb);
}
#else
static void amt_send_mld_gq(struct amt_dev *amt, struct amt_tunnel_list *tunnel)
{
}
#endif
static bool amt_queue_event(struct amt_dev *amt, enum amt_event event,
struct sk_buff *skb)
{
int index;
spin_lock_bh(&amt->lock);
if (amt->nr_events >= AMT_MAX_EVENTS) {
spin_unlock_bh(&amt->lock);
return 1;
}
index = (amt->event_idx + amt->nr_events) % AMT_MAX_EVENTS;
amt->events[index].event = event;
amt->events[index].skb = skb;
amt->nr_events++;
amt->event_idx %= AMT_MAX_EVENTS;
queue_work(amt_wq, &amt->event_wq);
spin_unlock_bh(&amt->lock);
return 0;
}
static void amt_secret_work(struct work_struct *work)
{
struct amt_dev *amt = container_of(to_delayed_work(work),
struct amt_dev,
secret_wq);
spin_lock_bh(&amt->lock);
get_random_bytes(&amt->key, sizeof(siphash_key_t));
spin_unlock_bh(&amt->lock);
mod_delayed_work(amt_wq, &amt->secret_wq,
msecs_to_jiffies(AMT_SECRET_TIMEOUT));
}
static void amt_event_send_discovery(struct amt_dev *amt)
{
if (amt->status > AMT_STATUS_SENT_DISCOVERY)
goto out;
get_random_bytes(&amt->nonce, sizeof(__be32));
amt_send_discovery(amt);
out:
mod_delayed_work(amt_wq, &amt->discovery_wq,
msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
}
static void amt_discovery_work(struct work_struct *work)
{
struct amt_dev *amt = container_of(to_delayed_work(work),
struct amt_dev,
discovery_wq);
if (amt_queue_event(amt, AMT_EVENT_SEND_DISCOVERY, NULL))
mod_delayed_work(amt_wq, &amt->discovery_wq,
msecs_to_jiffies(AMT_DISCOVERY_TIMEOUT));
}
static void amt_event_send_request(struct amt_dev *amt)
{
u32 exp;
if (amt->status < AMT_STATUS_RECEIVED_ADVERTISEMENT)
goto out;
if (amt->req_cnt > AMT_MAX_REQ_COUNT) {
netdev_dbg(amt->dev, "Gateway is not ready");
amt->qi = AMT_INIT_REQ_TIMEOUT;
WRITE_ONCE(amt->ready4, false);
WRITE_ONCE(amt->ready6, false);
amt->remote_ip = 0;
amt_update_gw_status(amt, AMT_STATUS_INIT, false);
amt->req_cnt = 0;
amt->nonce = 0;
goto out;
}
if (!amt->req_cnt) {
WRITE_ONCE(amt->ready4, false);
WRITE_ONCE(amt->ready6, false);
get_random_bytes(&amt->nonce, sizeof(__be32));
}
amt_send_request(amt, false);
amt_send_request(amt, true);
amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
amt->req_cnt++;
out:
exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
}
static void amt_req_work(struct work_struct *work)
{
struct amt_dev *amt = container_of(to_delayed_work(work),
struct amt_dev,
req_wq);
if (amt_queue_event(amt, AMT_EVENT_SEND_REQUEST, NULL))
mod_delayed_work(amt_wq, &amt->req_wq,
msecs_to_jiffies(100));
}
static bool amt_send_membership_update(struct amt_dev *amt,
struct sk_buff *skb,
bool v6)
{
struct amt_header_membership_update *amtmu;