forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 2
/
Copy pathlink.c
2272 lines (1983 loc) · 60.3 KB
/
link.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
/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012-2015, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "subscr.h"
#include "link.h"
#include "bcast.h"
#include "socket.h"
#include "name_distr.h"
#include "discover.h"
#include "netlink.h"
#include <linux/pkt_sched.h>
/*
* Error message prefixes
*/
static const char *link_co_err = "Link changeover error, ";
static const char *link_rst_msg = "Resetting link ";
static const char *link_unk_evt = "Unknown link event ";
static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
[TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC },
[TIPC_NLA_LINK_NAME] = {
.type = NLA_STRING,
.len = TIPC_MAX_LINK_NAME
},
[TIPC_NLA_LINK_MTU] = { .type = NLA_U32 },
[TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_UP] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_ACTIVE] = { .type = NLA_FLAG },
[TIPC_NLA_LINK_PROP] = { .type = NLA_NESTED },
[TIPC_NLA_LINK_STATS] = { .type = NLA_NESTED },
[TIPC_NLA_LINK_RX] = { .type = NLA_U32 },
[TIPC_NLA_LINK_TX] = { .type = NLA_U32 }
};
/* Properties valid for media, bearar and link */
static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
[TIPC_NLA_PROP_UNSPEC] = { .type = NLA_UNSPEC },
[TIPC_NLA_PROP_PRIO] = { .type = NLA_U32 },
[TIPC_NLA_PROP_TOL] = { .type = NLA_U32 },
[TIPC_NLA_PROP_WIN] = { .type = NLA_U32 }
};
/*
* Out-of-range value for link session numbers
*/
#define INVALID_SESSION 0x10000
/*
* Link state events:
*/
#define STARTING_EVT 856384768 /* link processing trigger */
#define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */
#define TIMEOUT_EVT 560817u /* link timer expired */
/*
* State value stored in 'failover_pkts'
*/
#define FIRST_FAILOVER 0xffffu
static void link_handle_out_of_seq_msg(struct tipc_link *link,
struct sk_buff *skb);
static void tipc_link_proto_rcv(struct tipc_link *link,
struct sk_buff *skb);
static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
static void link_state_event(struct tipc_link *l_ptr, u32 event);
static void link_reset_statistics(struct tipc_link *l_ptr);
static void link_print(struct tipc_link *l_ptr, const char *str);
static void tipc_link_sync_xmit(struct tipc_link *l);
static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
/*
* Simple link routines
*/
static unsigned int align(unsigned int i)
{
return (i + 3) & ~3u;
}
static void tipc_link_release(struct kref *kref)
{
kfree(container_of(kref, struct tipc_link, ref));
}
static void tipc_link_get(struct tipc_link *l_ptr)
{
kref_get(&l_ptr->ref);
}
static void tipc_link_put(struct tipc_link *l_ptr)
{
kref_put(&l_ptr->ref, tipc_link_release);
}
static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
{
if (l->owner->active_links[0] != l)
return l->owner->active_links[0];
return l->owner->active_links[1];
}
/*
* Simple non-static link routines (i.e. referenced outside this file)
*/
int tipc_link_is_up(struct tipc_link *l_ptr)
{
if (!l_ptr)
return 0;
return link_working_working(l_ptr) || link_working_unknown(l_ptr);
}
int tipc_link_is_active(struct tipc_link *l_ptr)
{
return (l_ptr->owner->active_links[0] == l_ptr) ||
(l_ptr->owner->active_links[1] == l_ptr);
}
/**
* link_timeout - handle expiration of link timer
* @l_ptr: pointer to link
*/
static void link_timeout(unsigned long data)
{
struct tipc_link *l_ptr = (struct tipc_link *)data;
struct sk_buff *skb;
tipc_node_lock(l_ptr->owner);
/* update counters used in statistical profiling of send traffic */
l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
l_ptr->stats.queue_sz_counts++;
skb = skb_peek(&l_ptr->transmq);
if (skb) {
struct tipc_msg *msg = buf_msg(skb);
u32 length = msg_size(msg);
if ((msg_user(msg) == MSG_FRAGMENTER) &&
(msg_type(msg) == FIRST_FRAGMENT)) {
length = msg_size(msg_get_wrapped(msg));
}
if (length) {
l_ptr->stats.msg_lengths_total += length;
l_ptr->stats.msg_length_counts++;
if (length <= 64)
l_ptr->stats.msg_length_profile[0]++;
else if (length <= 256)
l_ptr->stats.msg_length_profile[1]++;
else if (length <= 1024)
l_ptr->stats.msg_length_profile[2]++;
else if (length <= 4096)
l_ptr->stats.msg_length_profile[3]++;
else if (length <= 16384)
l_ptr->stats.msg_length_profile[4]++;
else if (length <= 32768)
l_ptr->stats.msg_length_profile[5]++;
else
l_ptr->stats.msg_length_profile[6]++;
}
}
/* do all other link processing performed on a periodic basis */
link_state_event(l_ptr, TIMEOUT_EVT);
if (skb_queue_len(&l_ptr->backlogq))
tipc_link_push_packets(l_ptr);
tipc_node_unlock(l_ptr->owner);
tipc_link_put(l_ptr);
}
static void link_set_timer(struct tipc_link *link, unsigned long time)
{
if (!mod_timer(&link->timer, jiffies + time))
tipc_link_get(link);
}
/**
* tipc_link_create - create a new link
* @n_ptr: pointer to associated node
* @b_ptr: pointer to associated bearer
* @media_addr: media address to use when sending messages over link
*
* Returns pointer to link.
*/
struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
struct tipc_bearer *b_ptr,
const struct tipc_media_addr *media_addr)
{
struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
struct tipc_link *l_ptr;
struct tipc_msg *msg;
char *if_name;
char addr_string[16];
u32 peer = n_ptr->addr;
if (n_ptr->link_cnt >= MAX_BEARERS) {
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n",
n_ptr->link_cnt, addr_string, MAX_BEARERS);
return NULL;
}
if (n_ptr->links[b_ptr->identity]) {
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_err("Attempt to establish second link on <%s> to %s\n",
b_ptr->name, addr_string);
return NULL;
}
l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
if (!l_ptr) {
pr_warn("Link creation failed, no memory\n");
return NULL;
}
kref_init(&l_ptr->ref);
l_ptr->addr = peer;
if_name = strchr(b_ptr->name, ':') + 1;
sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
tipc_node(tn->own_addr),
if_name,
tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
/* note: peer i/f name is updated by reset/activate message */
memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
l_ptr->owner = n_ptr;
l_ptr->checkpoint = 1;
l_ptr->peer_session = INVALID_SESSION;
l_ptr->bearer_id = b_ptr->identity;
link_set_supervision_props(l_ptr, b_ptr->tolerance);
l_ptr->state = RESET_UNKNOWN;
l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
msg = l_ptr->pmsg;
tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
l_ptr->addr);
msg_set_size(msg, sizeof(l_ptr->proto_msg));
msg_set_session(msg, (tn->random & 0xffff));
msg_set_bearer_id(msg, b_ptr->identity);
strcpy((char *)msg_data(msg), if_name);
l_ptr->net_plane = b_ptr->net_plane;
l_ptr->advertised_mtu = b_ptr->mtu;
l_ptr->mtu = l_ptr->advertised_mtu;
l_ptr->priority = b_ptr->priority;
tipc_link_set_queue_limits(l_ptr, b_ptr->window);
l_ptr->next_out_no = 1;
__skb_queue_head_init(&l_ptr->transmq);
__skb_queue_head_init(&l_ptr->backlogq);
__skb_queue_head_init(&l_ptr->deferdq);
skb_queue_head_init(&l_ptr->wakeupq);
skb_queue_head_init(&l_ptr->inputq);
skb_queue_head_init(&l_ptr->namedq);
link_reset_statistics(l_ptr);
tipc_node_attach_link(n_ptr, l_ptr);
setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
link_state_event(l_ptr, STARTING_EVT);
return l_ptr;
}
/**
* tipc_link_delete - Delete a link
* @l: link to be deleted
*/
void tipc_link_delete(struct tipc_link *l)
{
tipc_link_reset(l);
if (del_timer(&l->timer))
tipc_link_put(l);
l->flags |= LINK_STOPPED;
/* Delete link now, or when timer is finished: */
tipc_link_reset_fragments(l);
tipc_node_detach_link(l->owner, l);
tipc_link_put(l);
}
void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
bool shutting_down)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_link *link;
struct tipc_node *node;
rcu_read_lock();
list_for_each_entry_rcu(node, &tn->node_list, list) {
tipc_node_lock(node);
link = node->links[bearer_id];
if (link)
tipc_link_delete(link);
tipc_node_unlock(node);
}
rcu_read_unlock();
}
/**
* link_schedule_user - schedule a message sender for wakeup after congestion
* @link: congested link
* @list: message that was attempted sent
* Create pseudo msg to send back to user when congestion abates
* Only consumes message if there is an error
*/
static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
{
struct tipc_msg *msg = buf_msg(skb_peek(list));
int imp = msg_importance(msg);
u32 oport = msg_origport(msg);
u32 addr = link_own_addr(link);
struct sk_buff *skb;
/* This really cannot happen... */
if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
tipc_link_reset(link);
goto err;
}
/* Non-blocking sender: */
if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
return -ELINKCONG;
/* Create and schedule wakeup pseudo message */
skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
addr, addr, oport, 0, 0);
if (!skb)
goto err;
TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
TIPC_SKB_CB(skb)->chain_imp = imp;
skb_queue_tail(&link->wakeupq, skb);
link->stats.link_congs++;
return -ELINKCONG;
err:
__skb_queue_purge(list);
return -ENOBUFS;
}
/**
* link_prepare_wakeup - prepare users for wakeup after congestion
* @link: congested link
* Move a number of waiting users, as permitted by available space in
* the send queue, from link wait queue to node wait queue for wakeup
*/
void link_prepare_wakeup(struct tipc_link *l)
{
int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
int imp, lim;
struct sk_buff *skb, *tmp;
skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
imp = TIPC_SKB_CB(skb)->chain_imp;
lim = l->window + l->backlog[imp].limit;
pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
if ((pnd[imp] + l->backlog[imp].len) >= lim)
break;
skb_unlink(skb, &l->wakeupq);
skb_queue_tail(&l->inputq, skb);
l->owner->inputq = &l->inputq;
l->owner->action_flags |= TIPC_MSG_EVT;
}
}
/**
* tipc_link_reset_fragments - purge link's inbound message fragments queue
* @l_ptr: pointer to link
*/
void tipc_link_reset_fragments(struct tipc_link *l_ptr)
{
kfree_skb(l_ptr->reasm_buf);
l_ptr->reasm_buf = NULL;
}
static void tipc_link_purge_backlog(struct tipc_link *l)
{
__skb_queue_purge(&l->backlogq);
l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
}
/**
* tipc_link_purge_queues - purge all pkt queues associated with link
* @l_ptr: pointer to link
*/
void tipc_link_purge_queues(struct tipc_link *l_ptr)
{
__skb_queue_purge(&l_ptr->deferdq);
__skb_queue_purge(&l_ptr->transmq);
tipc_link_purge_backlog(l_ptr);
tipc_link_reset_fragments(l_ptr);
}
void tipc_link_reset(struct tipc_link *l_ptr)
{
u32 prev_state = l_ptr->state;
int was_active_link = tipc_link_is_active(l_ptr);
struct tipc_node *owner = l_ptr->owner;
struct tipc_link *pl = tipc_parallel_link(l_ptr);
msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
/* Link is down, accept any session */
l_ptr->peer_session = INVALID_SESSION;
/* Prepare for renewed mtu size negotiation */
l_ptr->mtu = l_ptr->advertised_mtu;
l_ptr->state = RESET_UNKNOWN;
if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
return;
tipc_node_link_down(l_ptr->owner, l_ptr);
tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
l_ptr->flags |= LINK_FAILINGOVER;
l_ptr->failover_checkpt = l_ptr->next_in_no;
pl->failover_pkts = FIRST_FAILOVER;
pl->failover_checkpt = l_ptr->next_in_no;
pl->failover_skb = l_ptr->reasm_buf;
} else {
kfree_skb(l_ptr->reasm_buf);
}
/* Clean up all queues, except inputq: */
__skb_queue_purge(&l_ptr->transmq);
__skb_queue_purge(&l_ptr->deferdq);
if (!owner->inputq)
owner->inputq = &l_ptr->inputq;
skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
if (!skb_queue_empty(owner->inputq))
owner->action_flags |= TIPC_MSG_EVT;
tipc_link_purge_backlog(l_ptr);
l_ptr->reasm_buf = NULL;
l_ptr->rcv_unacked = 0;
l_ptr->checkpoint = 1;
l_ptr->next_out_no = 1;
l_ptr->fsm_msg_cnt = 0;
l_ptr->stale_count = 0;
link_reset_statistics(l_ptr);
}
void tipc_link_reset_list(struct net *net, unsigned int bearer_id)
{
struct tipc_net *tn = net_generic(net, tipc_net_id);
struct tipc_link *l_ptr;
struct tipc_node *n_ptr;
rcu_read_lock();
list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
tipc_node_lock(n_ptr);
l_ptr = n_ptr->links[bearer_id];
if (l_ptr)
tipc_link_reset(l_ptr);
tipc_node_unlock(n_ptr);
}
rcu_read_unlock();
}
static void link_activate(struct tipc_link *link)
{
struct tipc_node *node = link->owner;
link->next_in_no = 1;
link->stats.recv_info = 1;
tipc_node_link_up(node, link);
tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
}
/**
* link_state_event - link finite state machine
* @l_ptr: pointer to link
* @event: state machine event to process
*/
static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
{
struct tipc_link *other;
unsigned long cont_intv = l_ptr->cont_intv;
if (l_ptr->flags & LINK_STOPPED)
return;
if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
return; /* Not yet. */
if (l_ptr->flags & LINK_FAILINGOVER) {
if (event == TIMEOUT_EVT)
link_set_timer(l_ptr, cont_intv);
return;
}
switch (l_ptr->state) {
case WORKING_WORKING:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
break;
case TIMEOUT_EVT:
if (l_ptr->next_in_no != l_ptr->checkpoint) {
l_ptr->checkpoint = l_ptr->next_in_no;
if (tipc_bclink_acks_missing(l_ptr->owner)) {
tipc_link_proto_xmit(l_ptr, STATE_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
}
link_set_timer(l_ptr, cont_intv);
break;
}
l_ptr->state = WORKING_UNKNOWN;
l_ptr->fsm_msg_cnt = 0;
tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv / 4);
break;
case RESET_MSG:
pr_debug("%s<%s>, requested by peer\n",
link_rst_msg, l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_debug("%s%u in WW state\n", link_unk_evt, event);
}
break;
case WORKING_UNKNOWN:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
pr_debug("%s<%s>, requested by peer while probing\n",
link_rst_msg, l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
case TIMEOUT_EVT:
if (l_ptr->next_in_no != l_ptr->checkpoint) {
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
l_ptr->checkpoint = l_ptr->next_in_no;
if (tipc_bclink_acks_missing(l_ptr->owner)) {
tipc_link_proto_xmit(l_ptr, STATE_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
}
link_set_timer(l_ptr, cont_intv);
} else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
tipc_link_proto_xmit(l_ptr, STATE_MSG,
1, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv / 4);
} else { /* Link has failed */
pr_debug("%s<%s>, peer not responding\n",
link_rst_msg, l_ptr->name);
tipc_link_reset(l_ptr);
l_ptr->state = RESET_UNKNOWN;
l_ptr->fsm_msg_cnt = 0;
tipc_link_proto_xmit(l_ptr, RESET_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
}
break;
default:
pr_err("%s%u in WU state\n", link_unk_evt, event);
}
break;
case RESET_UNKNOWN:
switch (event) {
case TRAFFIC_MSG_EVT:
break;
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other))
break;
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_activate(l_ptr);
tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
if (l_ptr->owner->working_links == 1)
tipc_link_sync_xmit(l_ptr);
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
l_ptr->state = RESET_RESET;
l_ptr->fsm_msg_cnt = 0;
tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
1, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
case STARTING_EVT:
l_ptr->flags |= LINK_STARTED;
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
case TIMEOUT_EVT:
tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_err("%s%u in RU state\n", link_unk_evt, event);
}
break;
case RESET_RESET:
switch (event) {
case TRAFFIC_MSG_EVT:
case ACTIVATE_MSG:
other = l_ptr->owner->active_links[0];
if (other && link_working_unknown(other))
break;
l_ptr->state = WORKING_WORKING;
l_ptr->fsm_msg_cnt = 0;
link_activate(l_ptr);
tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
if (l_ptr->owner->working_links == 1)
tipc_link_sync_xmit(l_ptr);
link_set_timer(l_ptr, cont_intv);
break;
case RESET_MSG:
break;
case TIMEOUT_EVT:
tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
0, 0, 0, 0);
l_ptr->fsm_msg_cnt++;
link_set_timer(l_ptr, cont_intv);
break;
default:
pr_err("%s%u in RR state\n", link_unk_evt, event);
}
break;
default:
pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
}
}
/**
* __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
* @link: link to use
* @list: chain of buffers containing message
*
* Consumes the buffer chain, except when returning -ELINKCONG,
* since the caller then may want to make more send attempts.
* Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
* Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
*/
int __tipc_link_xmit(struct net *net, struct tipc_link *link,
struct sk_buff_head *list)
{
struct tipc_msg *msg = buf_msg(skb_peek(list));
unsigned int maxwin = link->window;
unsigned int imp = msg_importance(msg);
uint mtu = link->mtu;
uint ack = mod(link->next_in_no - 1);
uint seqno = link->next_out_no;
uint bc_last_in = link->owner->bclink.last_in;
struct tipc_media_addr *addr = &link->media_addr;
struct sk_buff_head *transmq = &link->transmq;
struct sk_buff_head *backlogq = &link->backlogq;
struct sk_buff *skb, *tmp;
/* Match backlog limit against msg importance: */
if (unlikely(link->backlog[imp].len >= link->backlog[imp].limit))
return link_schedule_user(link, list);
if (unlikely(msg_size(msg) > mtu)) {
__skb_queue_purge(list);
return -EMSGSIZE;
}
/* Prepare each packet for sending, and add to relevant queue: */
skb_queue_walk_safe(list, skb, tmp) {
__skb_unlink(skb, list);
msg = buf_msg(skb);
msg_set_seqno(msg, seqno);
msg_set_ack(msg, ack);
msg_set_bcast_ack(msg, bc_last_in);
if (likely(skb_queue_len(transmq) < maxwin)) {
__skb_queue_tail(transmq, skb);
tipc_bearer_send(net, link->bearer_id, skb, addr);
link->rcv_unacked = 0;
seqno++;
continue;
}
if (tipc_msg_bundle(skb_peek_tail(backlogq), skb, mtu)) {
link->stats.sent_bundled++;
continue;
}
if (tipc_msg_make_bundle(&skb, mtu, link->addr)) {
link->stats.sent_bundled++;
link->stats.sent_bundles++;
imp = msg_importance(buf_msg(skb));
}
__skb_queue_tail(backlogq, skb);
link->backlog[imp].len++;
seqno++;
}
link->next_out_no = seqno;
return 0;
}
static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
{
skb_queue_head_init(list);
__skb_queue_tail(list, skb);
}
static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
{
struct sk_buff_head head;
skb2list(skb, &head);
return __tipc_link_xmit(link->owner->net, link, &head);
}
/* tipc_link_xmit_skb(): send single buffer to destination
* Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
* messages, which will not be rejected
* The only exception is datagram messages rerouted after secondary
* lookup, which are rare and safe to dispose of anyway.
* TODO: Return real return value, and let callers use
* tipc_wait_for_sendpkt() where applicable
*/
int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
u32 selector)
{
struct sk_buff_head head;
int rc;
skb2list(skb, &head);
rc = tipc_link_xmit(net, &head, dnode, selector);
if (rc == -ELINKCONG)
kfree_skb(skb);
return 0;
}
/**
* tipc_link_xmit() is the general link level function for message sending
* @net: the applicable net namespace
* @list: chain of buffers containing message
* @dsz: amount of user data to be sent
* @dnode: address of destination node
* @selector: a number used for deterministic link selection
* Consumes the buffer chain, except when returning -ELINKCONG
* Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
*/
int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
u32 selector)
{
struct tipc_link *link = NULL;
struct tipc_node *node;
int rc = -EHOSTUNREACH;
node = tipc_node_find(net, dnode);
if (node) {
tipc_node_lock(node);
link = node->active_links[selector & 1];
if (link)
rc = __tipc_link_xmit(net, link, list);
tipc_node_unlock(node);
tipc_node_put(node);
}
if (link)
return rc;
if (likely(in_own_node(net, dnode))) {
tipc_sk_rcv(net, list);
return 0;
}
__skb_queue_purge(list);
return rc;
}
/*
* tipc_link_sync_xmit - synchronize broadcast link endpoints.
*
* Give a newly added peer node the sequence number where it should
* start receiving and acking broadcast packets.
*
* Called with node locked
*/
static void tipc_link_sync_xmit(struct tipc_link *link)
{
struct sk_buff *skb;
struct tipc_msg *msg;
skb = tipc_buf_acquire(INT_H_SIZE);
if (!skb)
return;
msg = buf_msg(skb);
tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
INT_H_SIZE, link->addr);
msg_set_last_bcast(msg, link->owner->bclink.acked);
__tipc_link_xmit_skb(link, skb);
}
/*
* tipc_link_sync_rcv - synchronize broadcast link endpoints.
* Receive the sequence number where we should start receiving and
* acking broadcast packets from a newly added peer node, and open
* up for reception of such packets.
*
* Called with node locked
*/
static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
n->bclink.recv_permitted = true;
kfree_skb(buf);
}
/*
* tipc_link_push_packets - push unsent packets to bearer
*
* Push out the unsent messages of a link where congestion
* has abated. Node is locked.
*
* Called with node locked
*/
void tipc_link_push_packets(struct tipc_link *link)
{
struct sk_buff *skb;
struct tipc_msg *msg;
unsigned int ack = mod(link->next_in_no - 1);
while (skb_queue_len(&link->transmq) < link->window) {
skb = __skb_dequeue(&link->backlogq);
if (!skb)
break;
msg = buf_msg(skb);
link->backlog[msg_importance(msg)].len--;
msg_set_ack(msg, ack);
msg_set_bcast_ack(msg, link->owner->bclink.last_in);
link->rcv_unacked = 0;
__skb_queue_tail(&link->transmq, skb);
tipc_bearer_send(link->owner->net, link->bearer_id,
skb, &link->media_addr);
}
}
void tipc_link_reset_all(struct tipc_node *node)
{
char addr_string[16];
u32 i;
tipc_node_lock(node);
pr_warn("Resetting all links to %s\n",
tipc_addr_string_fill(addr_string, node->addr));
for (i = 0; i < MAX_BEARERS; i++) {
if (node->links[i]) {
link_print(node->links[i], "Resetting link\n");
tipc_link_reset(node->links[i]);
}
}
tipc_node_unlock(node);
}
static void link_retransmit_failure(struct tipc_link *l_ptr,
struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
struct net *net = l_ptr->owner->net;
pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
if (l_ptr->addr) {
/* Handle failure on standard link */
link_print(l_ptr, "Resetting link\n");
tipc_link_reset(l_ptr);
} else {
/* Handle failure on broadcast link */
struct tipc_node *n_ptr;
char addr_string[16];
pr_info("Msg seq number: %u, ", msg_seqno(msg));
pr_cont("Outstanding acks: %lu\n",
(unsigned long) TIPC_SKB_CB(buf)->handle);
n_ptr = tipc_bclink_retransmit_to(net);
tipc_addr_string_fill(addr_string, n_ptr->addr);
pr_info("Broadcast link info for %s\n", addr_string);
pr_info("Reception permitted: %d, Acked: %u\n",
n_ptr->bclink.recv_permitted,
n_ptr->bclink.acked);
pr_info("Last in: %u, Oos state: %u, Last sent: %u\n",
n_ptr->bclink.last_in,
n_ptr->bclink.oos_state,
n_ptr->bclink.last_sent);
n_ptr->action_flags |= TIPC_BCAST_RESET;
l_ptr->stale_count = 0;
}
}
void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
u32 retransmits)
{
struct tipc_msg *msg;
if (!skb)
return;
msg = buf_msg(skb);
/* Detect repeated retransmit failures */
if (l_ptr->last_retransmitted == msg_seqno(msg)) {
if (++l_ptr->stale_count > 100) {
link_retransmit_failure(l_ptr, skb);
return;
}
} else {
l_ptr->last_retransmitted = msg_seqno(msg);
l_ptr->stale_count = 1;
}
skb_queue_walk_from(&l_ptr->transmq, skb) {
if (!retransmits)
break;
msg = buf_msg(skb);
msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
&l_ptr->media_addr);
retransmits--;
l_ptr->stats.retransmitted++;
}
}
/* link_synch(): check if all packets arrived before the synch
* point have been consumed
* Returns true if the parallel links are synched, otherwise false
*/
static bool link_synch(struct tipc_link *l)
{
unsigned int post_synch;
struct tipc_link *pl;
pl = tipc_parallel_link(l);
if (pl == l)