summaryrefslogtreecommitdiff
path: root/net/batman-adv/bat_v.c
blob: 4ff6cf1ecae70d0a89677b21165ded2fc005e9af (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2013-2019  B.A.T.M.A.N. contributors:
 *
 * Linus Lüssing, Marek Lindner
 */

#include "bat_v.h"
#include "main.h"

#include <linux/atomic.h>
#include <linux/cache.h>
#include <linux/errno.h>
#include <linux/if_ether.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/netlink.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <net/genetlink.h>
#include <net/netlink.h>
#include <uapi/linux/batadv_packet.h>
#include <uapi/linux/batman_adv.h>

#include "bat_algo.h"
#include "bat_v_elp.h"
#include "bat_v_ogm.h"
#include "gateway_client.h"
#include "gateway_common.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "netlink.h"
#include "originator.h"

static void batadv_v_iface_activate(struct batadv_hard_iface *hard_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct batadv_hard_iface *primary_if;

	primary_if = batadv_primary_if_get_selected(bat_priv);

	if (primary_if) {
		batadv_v_elp_iface_activate(primary_if, hard_iface);
		batadv_hardif_put(primary_if);
	}

	/* B.A.T.M.A.N. V does not use any queuing mechanism, therefore it can
	 * set the interface as ACTIVE right away, without any risk of race
	 * condition
	 */
	if (hard_iface->if_status == BATADV_IF_TO_BE_ACTIVATED)
		hard_iface->if_status = BATADV_IF_ACTIVE;
}

static int batadv_v_iface_enable(struct batadv_hard_iface *hard_iface)
{
	int ret;

	ret = batadv_v_elp_iface_enable(hard_iface);
	if (ret < 0)
		return ret;

	ret = batadv_v_ogm_iface_enable(hard_iface);
	if (ret < 0)
		batadv_v_elp_iface_disable(hard_iface);

	return ret;
}

static void batadv_v_iface_disable(struct batadv_hard_iface *hard_iface)
{
	batadv_v_ogm_iface_disable(hard_iface);
	batadv_v_elp_iface_disable(hard_iface);
}

static void batadv_v_primary_iface_set(struct batadv_hard_iface *hard_iface)
{
	batadv_v_elp_primary_iface_set(hard_iface);
	batadv_v_ogm_primary_iface_set(hard_iface);
}

/**
 * batadv_v_iface_update_mac() - react to hard-interface MAC address change
 * @hard_iface: the modified interface
 *
 * If the modified interface is the primary one, update the originator
 * address in the ELP and OGM messages to reflect the new MAC address.
 */
static void batadv_v_iface_update_mac(struct batadv_hard_iface *hard_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
	struct batadv_hard_iface *primary_if;

	primary_if = batadv_primary_if_get_selected(bat_priv);
	if (primary_if != hard_iface)
		goto out;

	batadv_v_primary_iface_set(hard_iface);
out:
	if (primary_if)
		batadv_hardif_put(primary_if);
}

static void
batadv_v_hardif_neigh_init(struct batadv_hardif_neigh_node *hardif_neigh)
{
	ewma_throughput_init(&hardif_neigh->bat_v.throughput);
	INIT_WORK(&hardif_neigh->bat_v.metric_work,
		  batadv_v_elp_throughput_metric_update);
}

#ifdef CONFIG_BATMAN_ADV_DEBUGFS
/**
 * batadv_v_orig_print_neigh() - print neighbors for the originator table
 * @orig_node: the orig_node for which the neighbors are printed
 * @if_outgoing: outgoing interface for these entries
 * @seq: debugfs table seq_file struct
 *
 * Must be called while holding an rcu lock.
 */
static void
batadv_v_orig_print_neigh(struct batadv_orig_node *orig_node,
			  struct batadv_hard_iface *if_outgoing,
			  struct seq_file *seq)
{
	struct batadv_neigh_node *neigh_node;
	struct batadv_neigh_ifinfo *n_ifinfo;

	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
		n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
		if (!n_ifinfo)
			continue;

		seq_printf(seq, " %pM (%9u.%1u)",
			   neigh_node->addr,
			   n_ifinfo->bat_v.throughput / 10,
			   n_ifinfo->bat_v.throughput % 10);

		batadv_neigh_ifinfo_put(n_ifinfo);
	}
}

/**
 * batadv_v_hardif_neigh_print() - print a single ELP neighbour node
 * @seq: neighbour table seq_file struct
 * @hardif_neigh: hardif neighbour information
 */
static void
batadv_v_hardif_neigh_print(struct seq_file *seq,
			    struct batadv_hardif_neigh_node *hardif_neigh)
{
	int last_secs, last_msecs;
	u32 throughput;

	last_secs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) / 1000;
	last_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen) % 1000;
	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);

	seq_printf(seq, "%pM %4i.%03is (%9u.%1u) [%10s]\n",
		   hardif_neigh->addr, last_secs, last_msecs, throughput / 10,
		   throughput % 10, hardif_neigh->if_incoming->net_dev->name);
}

/**
 * batadv_v_neigh_print() - print the single hop neighbour list
 * @bat_priv: the bat priv with all the soft interface information
 * @seq: neighbour table seq_file struct
 */
static void batadv_v_neigh_print(struct batadv_priv *bat_priv,
				 struct seq_file *seq)
{
	struct net_device *net_dev = (struct net_device *)seq->private;
	struct batadv_hardif_neigh_node *hardif_neigh;
	struct batadv_hard_iface *hard_iface;
	int batman_count = 0;

	seq_puts(seq,
		 "  Neighbor        last-seen ( throughput) [        IF]\n");

	rcu_read_lock();
	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
		if (hard_iface->soft_iface != net_dev)
			continue;

		hlist_for_each_entry_rcu(hardif_neigh,
					 &hard_iface->neigh_list, list) {
			batadv_v_hardif_neigh_print(seq, hardif_neigh);
			batman_count++;
		}
	}
	rcu_read_unlock();

	if (batman_count == 0)
		seq_puts(seq, "No batman nodes in range ...\n");
}
#endif

/**
 * batadv_v_neigh_dump_neigh() - Dump a neighbour into a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @seq: Sequence number of netlink message
 * @hardif_neigh: Neighbour to dump
 *
 * Return: Error code, or 0 on success
 */
static int
batadv_v_neigh_dump_neigh(struct sk_buff *msg, u32 portid, u32 seq,
			  struct batadv_hardif_neigh_node *hardif_neigh)
{
	void *hdr;
	unsigned int last_seen_msecs;
	u32 throughput;

	last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen);
	throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
	throughput = throughput * 100;

	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, NLM_F_MULTI,
			  BATADV_CMD_GET_NEIGHBORS);
	if (!hdr)
		return -ENOBUFS;

	if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
		    hardif_neigh->addr) ||
	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
			hardif_neigh->if_incoming->net_dev->ifindex) ||
	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
			last_seen_msecs) ||
	    nla_put_u32(msg, BATADV_ATTR_THROUGHPUT, throughput))
		goto nla_put_failure;

	genlmsg_end(msg, hdr);
	return 0;

 nla_put_failure:
	genlmsg_cancel(msg, hdr);
	return -EMSGSIZE;
}

/**
 * batadv_v_neigh_dump_hardif() - Dump the  neighbours of a hard interface into
 *  a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @seq: Sequence number of netlink message
 * @bat_priv: The bat priv with all the soft interface information
 * @hard_iface: The hard interface to be dumped
 * @idx_s: Entries to be skipped
 *
 * This function assumes the caller holds rcu_read_lock().
 *
 * Return: Error code, or 0 on success
 */
static int
batadv_v_neigh_dump_hardif(struct sk_buff *msg, u32 portid, u32 seq,
			   struct batadv_priv *bat_priv,
			   struct batadv_hard_iface *hard_iface,
			   int *idx_s)
{
	struct batadv_hardif_neigh_node *hardif_neigh;
	int idx = 0;

	hlist_for_each_entry_rcu(hardif_neigh,
				 &hard_iface->neigh_list, list) {
		if (idx++ < *idx_s)
			continue;

		if (batadv_v_neigh_dump_neigh(msg, portid, seq, hardif_neigh)) {
			*idx_s = idx - 1;
			return -EMSGSIZE;
		}
	}

	*idx_s = 0;
	return 0;
}

/**
 * batadv_v_neigh_dump() - Dump the neighbours of a hard interface  into a
 *  message
 * @msg: Netlink message to dump into
 * @cb: Control block containing additional options
 * @bat_priv: The bat priv with all the soft interface information
 * @single_hardif: Limit dumping to this hard interface
 */
static void
batadv_v_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb,
		    struct batadv_priv *bat_priv,
		    struct batadv_hard_iface *single_hardif)
{
	struct batadv_hard_iface *hard_iface;
	int i_hardif = 0;
	int i_hardif_s = cb->args[0];
	int idx = cb->args[1];
	int portid = NETLINK_CB(cb->skb).portid;

	rcu_read_lock();
	if (single_hardif) {
		if (i_hardif_s == 0) {
			if (batadv_v_neigh_dump_hardif(msg, portid,
						       cb->nlh->nlmsg_seq,
						       bat_priv, single_hardif,
						       &idx) == 0)
				i_hardif++;
		}
	} else {
		list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
			if (hard_iface->soft_iface != bat_priv->soft_iface)
				continue;

			if (i_hardif++ < i_hardif_s)
				continue;

			if (batadv_v_neigh_dump_hardif(msg, portid,
						       cb->nlh->nlmsg_seq,
						       bat_priv, hard_iface,
						       &idx)) {
				i_hardif--;
				break;
			}
		}
	}
	rcu_read_unlock();

	cb->args[0] = i_hardif;
	cb->args[1] = idx;
}

#ifdef CONFIG_BATMAN_ADV_DEBUGFS
/**
 * batadv_v_orig_print() - print the originator table
 * @bat_priv: the bat priv with all the soft interface information
 * @seq: debugfs table seq_file struct
 * @if_outgoing: the outgoing interface for which this should be printed
 */
static void batadv_v_orig_print(struct batadv_priv *bat_priv,
				struct seq_file *seq,
				struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_node *neigh_node;
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	int last_seen_msecs, last_seen_secs;
	struct batadv_orig_node *orig_node;
	struct batadv_neigh_ifinfo *n_ifinfo;
	unsigned long last_seen_jiffies;
	struct hlist_head *head;
	int batman_count = 0;
	u32 i;

	seq_puts(seq,
		 "  Originator      last-seen ( throughput)           Nexthop [outgoingIF]:   Potential nexthops ...\n");

	for (i = 0; i < hash->size; i++) {
		head = &hash->table[i];

		rcu_read_lock();
		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
			neigh_node = batadv_orig_router_get(orig_node,
							    if_outgoing);
			if (!neigh_node)
				continue;

			n_ifinfo = batadv_neigh_ifinfo_get(neigh_node,
							   if_outgoing);
			if (!n_ifinfo)
				goto next;

			last_seen_jiffies = jiffies - orig_node->last_seen;
			last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
			last_seen_secs = last_seen_msecs / 1000;
			last_seen_msecs = last_seen_msecs % 1000;

			seq_printf(seq, "%pM %4i.%03is (%9u.%1u) %pM [%10s]:",
				   orig_node->orig, last_seen_secs,
				   last_seen_msecs,
				   n_ifinfo->bat_v.throughput / 10,
				   n_ifinfo->bat_v.throughput % 10,
				   neigh_node->addr,
				   neigh_node->if_incoming->net_dev->name);

			batadv_v_orig_print_neigh(orig_node, if_outgoing, seq);
			seq_putc(seq, '\n');
			batman_count++;

next:
			batadv_neigh_node_put(neigh_node);
			if (n_ifinfo)
				batadv_neigh_ifinfo_put(n_ifinfo);
		}
		rcu_read_unlock();
	}

	if (batman_count == 0)
		seq_puts(seq, "No batman nodes in range ...\n");
}
#endif

/**
 * batadv_v_orig_dump_subentry() - Dump an originator subentry into a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @seq: Sequence number of netlink message
 * @bat_priv: The bat priv with all the soft interface information
 * @if_outgoing: Limit dump to entries with this outgoing interface
 * @orig_node: Originator to dump
 * @neigh_node: Single hops neighbour
 * @best: Is the best originator
 *
 * Return: Error code, or 0 on success
 */
static int
batadv_v_orig_dump_subentry(struct sk_buff *msg, u32 portid, u32 seq,
			    struct batadv_priv *bat_priv,
			    struct batadv_hard_iface *if_outgoing,
			    struct batadv_orig_node *orig_node,
			    struct batadv_neigh_node *neigh_node,
			    bool best)
{
	struct batadv_neigh_ifinfo *n_ifinfo;
	unsigned int last_seen_msecs;
	u32 throughput;
	void *hdr;

	n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
	if (!n_ifinfo)
		return 0;

	throughput = n_ifinfo->bat_v.throughput * 100;

	batadv_neigh_ifinfo_put(n_ifinfo);

	last_seen_msecs = jiffies_to_msecs(jiffies - orig_node->last_seen);

	if (if_outgoing != BATADV_IF_DEFAULT &&
	    if_outgoing != neigh_node->if_incoming)
		return 0;

	hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family, NLM_F_MULTI,
			  BATADV_CMD_GET_ORIGINATORS);
	if (!hdr)
		return -ENOBUFS;

	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN, orig_node->orig) ||
	    nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
		    neigh_node->addr) ||
	    nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
			neigh_node->if_incoming->net_dev->ifindex) ||
	    nla_put_u32(msg, BATADV_ATTR_THROUGHPUT, throughput) ||
	    nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
			last_seen_msecs))
		goto nla_put_failure;

	if (best && nla_put_flag(msg, BATADV_ATTR_FLAG_BEST))
		goto nla_put_failure;

	genlmsg_end(msg, hdr);
	return 0;

 nla_put_failure:
	genlmsg_cancel(msg, hdr);
	return -EMSGSIZE;
}

/**
 * batadv_v_orig_dump_entry() - Dump an originator entry into a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @seq: Sequence number of netlink message
 * @bat_priv: The bat priv with all the soft interface information
 * @if_outgoing: Limit dump to entries with this outgoing interface
 * @orig_node: Originator to dump
 * @sub_s: Number of sub entries to skip
 *
 * This function assumes the caller holds rcu_read_lock().
 *
 * Return: Error code, or 0 on success
 */
static int
batadv_v_orig_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
			 struct batadv_priv *bat_priv,
			 struct batadv_hard_iface *if_outgoing,
			 struct batadv_orig_node *orig_node, int *sub_s)
{
	struct batadv_neigh_node *neigh_node_best;
	struct batadv_neigh_node *neigh_node;
	int sub = 0;
	bool best;

	neigh_node_best = batadv_orig_router_get(orig_node, if_outgoing);
	if (!neigh_node_best)
		goto out;

	hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
		if (sub++ < *sub_s)
			continue;

		best = (neigh_node == neigh_node_best);

		if (batadv_v_orig_dump_subentry(msg, portid, seq, bat_priv,
						if_outgoing, orig_node,
						neigh_node, best)) {
			batadv_neigh_node_put(neigh_node_best);

			*sub_s = sub - 1;
			return -EMSGSIZE;
		}
	}

 out:
	if (neigh_node_best)
		batadv_neigh_node_put(neigh_node_best);

	*sub_s = 0;
	return 0;
}

/**
 * batadv_v_orig_dump_bucket() - Dump an originator bucket into a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @seq: Sequence number of netlink message
 * @bat_priv: The bat priv with all the soft interface information
 * @if_outgoing: Limit dump to entries with this outgoing interface
 * @head: Bucket to be dumped
 * @idx_s: Number of entries to be skipped
 * @sub: Number of sub entries to be skipped
 *
 * Return: Error code, or 0 on success
 */
static int
batadv_v_orig_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
			  struct batadv_priv *bat_priv,
			  struct batadv_hard_iface *if_outgoing,
			  struct hlist_head *head, int *idx_s, int *sub)
{
	struct batadv_orig_node *orig_node;
	int idx = 0;

	rcu_read_lock();
	hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
		if (idx++ < *idx_s)
			continue;

		if (batadv_v_orig_dump_entry(msg, portid, seq, bat_priv,
					     if_outgoing, orig_node, sub)) {
			rcu_read_unlock();
			*idx_s = idx - 1;
			return -EMSGSIZE;
		}
	}
	rcu_read_unlock();

	*idx_s = 0;
	*sub = 0;
	return 0;
}

/**
 * batadv_v_orig_dump() - Dump the originators into a message
 * @msg: Netlink message to dump into
 * @cb: Control block containing additional options
 * @bat_priv: The bat priv with all the soft interface information
 * @if_outgoing: Limit dump to entries with this outgoing interface
 */
static void
batadv_v_orig_dump(struct sk_buff *msg, struct netlink_callback *cb,
		   struct batadv_priv *bat_priv,
		   struct batadv_hard_iface *if_outgoing)
{
	struct batadv_hashtable *hash = bat_priv->orig_hash;
	struct hlist_head *head;
	int bucket = cb->args[0];
	int idx = cb->args[1];
	int sub = cb->args[2];
	int portid = NETLINK_CB(cb->skb).portid;

	while (bucket < hash->size) {
		head = &hash->table[bucket];

		if (batadv_v_orig_dump_bucket(msg, portid,
					      cb->nlh->nlmsg_seq,
					      bat_priv, if_outgoing, head, &idx,
					      &sub))
			break;

		bucket++;
	}

	cb->args[0] = bucket;
	cb->args[1] = idx;
	cb->args[2] = sub;
}

static int batadv_v_neigh_cmp(struct batadv_neigh_node *neigh1,
			      struct batadv_hard_iface *if_outgoing1,
			      struct batadv_neigh_node *neigh2,
			      struct batadv_hard_iface *if_outgoing2)
{
	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
	int ret = 0;

	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
	if (!ifinfo1)
		goto err_ifinfo1;

	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
	if (!ifinfo2)
		goto err_ifinfo2;

	ret = ifinfo1->bat_v.throughput - ifinfo2->bat_v.throughput;

	batadv_neigh_ifinfo_put(ifinfo2);
err_ifinfo2:
	batadv_neigh_ifinfo_put(ifinfo1);
err_ifinfo1:
	return ret;
}

static bool batadv_v_neigh_is_sob(struct batadv_neigh_node *neigh1,
				  struct batadv_hard_iface *if_outgoing1,
				  struct batadv_neigh_node *neigh2,
				  struct batadv_hard_iface *if_outgoing2)
{
	struct batadv_neigh_ifinfo *ifinfo1, *ifinfo2;
	u32 threshold;
	bool ret = false;

	ifinfo1 = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
	if (!ifinfo1)
		goto err_ifinfo1;

	ifinfo2 = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
	if (!ifinfo2)
		goto err_ifinfo2;

	threshold = ifinfo1->bat_v.throughput / 4;
	threshold = ifinfo1->bat_v.throughput - threshold;

	ret = ifinfo2->bat_v.throughput > threshold;

	batadv_neigh_ifinfo_put(ifinfo2);
err_ifinfo2:
	batadv_neigh_ifinfo_put(ifinfo1);
err_ifinfo1:
	return ret;
}

/**
 * batadv_v_init_sel_class() - initialize GW selection class
 * @bat_priv: the bat priv with all the soft interface information
 */
static void batadv_v_init_sel_class(struct batadv_priv *bat_priv)
{
	/* set default throughput difference threshold to 5Mbps */
	atomic_set(&bat_priv->gw.sel_class, 50);
}

static ssize_t batadv_v_store_sel_class(struct batadv_priv *bat_priv,
					char *buff, size_t count)
{
	u32 old_class, class;

	if (!batadv_parse_throughput(bat_priv->soft_iface, buff,
				     "B.A.T.M.A.N. V GW selection class",
				     &class))
		return -EINVAL;

	old_class = atomic_read(&bat_priv->gw.sel_class);
	atomic_set(&bat_priv->gw.sel_class, class);

	if (old_class != class)
		batadv_gw_reselect(bat_priv);

	return count;
}

static ssize_t batadv_v_show_sel_class(struct batadv_priv *bat_priv, char *buff)
{
	u32 class = atomic_read(&bat_priv->gw.sel_class);

	return sprintf(buff, "%u.%u MBit\n", class / 10, class % 10);
}

/**
 * batadv_v_gw_throughput_get() - retrieve the GW-bandwidth for a given GW
 * @gw_node: the GW to retrieve the metric for
 * @bw: the pointer where the metric will be stored. The metric is computed as
 *  the minimum between the GW advertised throughput and the path throughput to
 *  it in the mesh
 *
 * Return: 0 on success, -1 on failure
 */
static int batadv_v_gw_throughput_get(struct batadv_gw_node *gw_node, u32 *bw)
{
	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
	struct batadv_orig_node *orig_node;
	struct batadv_neigh_node *router;
	int ret = -1;

	orig_node = gw_node->orig_node;
	router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
	if (!router)
		goto out;

	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
	if (!router_ifinfo)
		goto out;

	/* the GW metric is computed as the minimum between the path throughput
	 * to reach the GW itself and the advertised bandwidth.
	 * This gives us an approximation of the effective throughput that the
	 * client can expect via this particular GW node
	 */
	*bw = router_ifinfo->bat_v.throughput;
	*bw = min_t(u32, *bw, gw_node->bandwidth_down);

	ret = 0;
out:
	if (router)
		batadv_neigh_node_put(router);
	if (router_ifinfo)
		batadv_neigh_ifinfo_put(router_ifinfo);

	return ret;
}

/**
 * batadv_v_gw_get_best_gw_node() - retrieve the best GW node
 * @bat_priv: the bat priv with all the soft interface information
 *
 * Return: the GW node having the best GW-metric, NULL if no GW is known
 */
static struct batadv_gw_node *
batadv_v_gw_get_best_gw_node(struct batadv_priv *bat_priv)
{
	struct batadv_gw_node *gw_node, *curr_gw = NULL;
	u32 max_bw = 0, bw;

	rcu_read_lock();
	hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
		if (!kref_get_unless_zero(&gw_node->refcount))
			continue;

		if (batadv_v_gw_throughput_get(gw_node, &bw) < 0)
			goto next;

		if (curr_gw && bw <= max_bw)
			goto next;

		if (curr_gw)
			batadv_gw_node_put(curr_gw);

		curr_gw = gw_node;
		kref_get(&curr_gw->refcount);
		max_bw = bw;

next:
		batadv_gw_node_put(gw_node);
	}
	rcu_read_unlock();

	return curr_gw;
}

/**
 * batadv_v_gw_is_eligible() - check if a originator would be selected as GW
 * @bat_priv: the bat priv with all the soft interface information
 * @curr_gw_orig: originator representing the currently selected GW
 * @orig_node: the originator representing the new candidate
 *
 * Return: true if orig_node can be selected as current GW, false otherwise
 */
static bool batadv_v_gw_is_eligible(struct batadv_priv *bat_priv,
				    struct batadv_orig_node *curr_gw_orig,
				    struct batadv_orig_node *orig_node)
{
	struct batadv_gw_node *curr_gw, *orig_gw = NULL;
	u32 gw_throughput, orig_throughput, threshold;
	bool ret = false;

	threshold = atomic_read(&bat_priv->gw.sel_class);

	curr_gw = batadv_gw_node_get(bat_priv, curr_gw_orig);
	if (!curr_gw) {
		ret = true;
		goto out;
	}

	if (batadv_v_gw_throughput_get(curr_gw, &gw_throughput) < 0) {
		ret = true;
		goto out;
	}

	orig_gw = batadv_gw_node_get(bat_priv, orig_node);
	if (!orig_gw)
		goto out;

	if (batadv_v_gw_throughput_get(orig_gw, &orig_throughput) < 0)
		goto out;

	if (orig_throughput < gw_throughput)
		goto out;

	if ((orig_throughput - gw_throughput) < threshold)
		goto out;

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Restarting gateway selection: better gateway found (throughput curr: %u, throughput new: %u)\n",
		   gw_throughput, orig_throughput);

	ret = true;
out:
	if (curr_gw)
		batadv_gw_node_put(curr_gw);
	if (orig_gw)
		batadv_gw_node_put(orig_gw);

	return ret;
}

#ifdef CONFIG_BATMAN_ADV_DEBUGFS
/* fails if orig_node has no router */
static int batadv_v_gw_write_buffer_text(struct batadv_priv *bat_priv,
					 struct seq_file *seq,
					 const struct batadv_gw_node *gw_node)
{
	struct batadv_gw_node *curr_gw;
	struct batadv_neigh_node *router;
	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
	int ret = -1;

	router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
	if (!router)
		goto out;

	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
	if (!router_ifinfo)
		goto out;

	curr_gw = batadv_gw_get_selected_gw_node(bat_priv);

	seq_printf(seq, "%s %pM (%9u.%1u) %pM [%10s]: %u.%u/%u.%u MBit\n",
		   (curr_gw == gw_node ? "=>" : "  "),
		   gw_node->orig_node->orig,
		   router_ifinfo->bat_v.throughput / 10,
		   router_ifinfo->bat_v.throughput % 10, router->addr,
		   router->if_incoming->net_dev->name,
		   gw_node->bandwidth_down / 10,
		   gw_node->bandwidth_down % 10,
		   gw_node->bandwidth_up / 10,
		   gw_node->bandwidth_up % 10);
	ret = seq_has_overflowed(seq) ? -1 : 0;

	if (curr_gw)
		batadv_gw_node_put(curr_gw);
out:
	if (router_ifinfo)
		batadv_neigh_ifinfo_put(router_ifinfo);
	if (router)
		batadv_neigh_node_put(router);
	return ret;
}

/**
 * batadv_v_gw_print() - print the gateway list
 * @bat_priv: the bat priv with all the soft interface information
 * @seq: gateway table seq_file struct
 */
static void batadv_v_gw_print(struct batadv_priv *bat_priv,
			      struct seq_file *seq)
{
	struct batadv_gw_node *gw_node;
	int gw_count = 0;

	seq_puts(seq,
		 "      Gateway        ( throughput)           Nexthop [outgoingIF]: advertised uplink bandwidth\n");

	rcu_read_lock();
	hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.gateway_list, list) {
		/* fails if orig_node has no router */
		if (batadv_v_gw_write_buffer_text(bat_priv, seq, gw_node) < 0)
			continue;

		gw_count++;
	}
	rcu_read_unlock();

	if (gw_count == 0)
		seq_puts(seq, "No gateways in range ...\n");
}
#endif

/**
 * batadv_v_gw_dump_entry() - Dump a gateway into a message
 * @msg: Netlink message to dump into
 * @portid: Port making netlink request
 * @cb: Control block containing additional options
 * @bat_priv: The bat priv with all the soft interface information
 * @gw_node: Gateway to be dumped
 *
 * Return: Error code, or 0 on success
 */
static int batadv_v_gw_dump_entry(struct sk_buff *msg, u32 portid,
				  struct netlink_callback *cb,
				  struct batadv_priv *bat_priv,
				  struct batadv_gw_node *gw_node)
{
	struct batadv_neigh_ifinfo *router_ifinfo = NULL;
	struct batadv_neigh_node *router;
	struct batadv_gw_node *curr_gw = NULL;
	int ret = 0;
	void *hdr;

	router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
	if (!router)
		goto out;

	router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
	if (!router_ifinfo)
		goto out;

	curr_gw = batadv_gw_get_selected_gw_node(bat_priv);

	hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq,
			  &batadv_netlink_family, NLM_F_MULTI,
			  BATADV_CMD_GET_GATEWAYS);
	if (!hdr) {
		ret = -ENOBUFS;
		goto out;
	}

	genl_dump_check_consistent(cb, hdr);

	ret = -EMSGSIZE;

	if (curr_gw == gw_node) {
		if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) {
			genlmsg_cancel(msg, hdr);
			goto out;
		}
	}

	if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
		    gw_node->orig_node->orig)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	if (nla_put_u32(msg, BATADV_ATTR_THROUGHPUT,
			router_ifinfo->bat_v.throughput)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	if (nla_put(msg, BATADV_ATTR_ROUTER, ETH_ALEN, router->addr)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	if (nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
			   router->if_incoming->net_dev->name)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	if (nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
			gw_node->bandwidth_down)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	if (nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP, gw_node->bandwidth_up)) {
		genlmsg_cancel(msg, hdr);
		goto out;
	}

	genlmsg_end(msg, hdr);
	ret = 0;

out:
	if (curr_gw)
		batadv_gw_node_put(curr_gw);
	if (router_ifinfo)
		batadv_neigh_ifinfo_put(router_ifinfo);
	if (router)
		batadv_neigh_node_put(router);
	return ret;
}

/**
 * batadv_v_gw_dump() - Dump gateways into a message
 * @msg: Netlink message to dump into
 * @cb: Control block containing additional options
 * @bat_priv: The bat priv with all the soft interface information
 */
static void batadv_v_gw_dump(struct sk_buff *msg, struct netlink_callback *cb,
			     struct batadv_priv *bat_priv)
{
	int portid = NETLINK_CB(cb->skb).portid;
	struct batadv_gw_node *gw_node;
	int idx_skip = cb->args[0];
	int idx = 0;

	spin_lock_bh(&bat_priv->gw.list_lock);
	cb->seq = bat_priv->gw.generation << 1 | 1;

	hlist_for_each_entry(gw_node, &bat_priv->gw.gateway_list, list) {
		if (idx++ < idx_skip)
			continue;

		if (batadv_v_gw_dump_entry(msg, portid, cb, bat_priv,
					   gw_node)) {
			idx_skip = idx - 1;
			goto unlock;
		}
	}

	idx_skip = idx;
unlock:
	spin_unlock_bh(&bat_priv->gw.list_lock);

	cb->args[0] = idx_skip;
}

static struct batadv_algo_ops batadv_batman_v __read_mostly = {
	.name = "BATMAN_V",
	.iface = {
		.activate = batadv_v_iface_activate,
		.enable = batadv_v_iface_enable,
		.disable = batadv_v_iface_disable,
		.update_mac = batadv_v_iface_update_mac,
		.primary_set = batadv_v_primary_iface_set,
	},
	.neigh = {
		.hardif_init = batadv_v_hardif_neigh_init,
		.cmp = batadv_v_neigh_cmp,
		.is_similar_or_better = batadv_v_neigh_is_sob,
#ifdef CONFIG_BATMAN_ADV_DEBUGFS
		.print = batadv_v_neigh_print,
#endif
		.dump = batadv_v_neigh_dump,
	},
	.orig = {
#ifdef CONFIG_BATMAN_ADV_DEBUGFS
		.print = batadv_v_orig_print,
#endif
		.dump = batadv_v_orig_dump,
	},
	.gw = {
		.init_sel_class = batadv_v_init_sel_class,
		.store_sel_class = batadv_v_store_sel_class,
		.show_sel_class = batadv_v_show_sel_class,
		.get_best_gw_node = batadv_v_gw_get_best_gw_node,
		.is_eligible = batadv_v_gw_is_eligible,
#ifdef CONFIG_BATMAN_ADV_DEBUGFS
		.print = batadv_v_gw_print,
#endif
		.dump = batadv_v_gw_dump,
	},
};

/**
 * batadv_v_hardif_init() - initialize the algorithm specific fields in the
 *  hard-interface object
 * @hard_iface: the hard-interface to initialize
 */
void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
{
	/* enable link throughput auto-detection by setting the throughput
	 * override to zero
	 */
	atomic_set(&hard_iface->bat_v.throughput_override, 0);
	atomic_set(&hard_iface->bat_v.elp_interval, 500);

	hard_iface->bat_v.aggr_len = 0;
	skb_queue_head_init(&hard_iface->bat_v.aggr_list);
	INIT_DELAYED_WORK(&hard_iface->bat_v.aggr_wq,
			  batadv_v_ogm_aggr_work);
}

/**
 * batadv_v_mesh_init() - initialize the B.A.T.M.A.N. V private resources for a
 *  mesh
 * @bat_priv: the object representing the mesh interface to initialise
 *
 * Return: 0 on success or a negative error code otherwise
 */
int batadv_v_mesh_init(struct batadv_priv *bat_priv)
{
	int ret = 0;

	ret = batadv_v_ogm_init(bat_priv);
	if (ret < 0)
		return ret;

	return 0;
}

/**
 * batadv_v_mesh_free() - free the B.A.T.M.A.N. V private resources for a mesh
 * @bat_priv: the object representing the mesh interface to free
 */
void batadv_v_mesh_free(struct batadv_priv *bat_priv)
{
	batadv_v_ogm_free(bat_priv);
}

/**
 * batadv_v_init() - B.A.T.M.A.N. V initialization function
 *
 * Description: Takes care of initializing all the subcomponents.
 * It is invoked upon module load only.
 *
 * Return: 0 on success or a negative error code otherwise
 */
int __init batadv_v_init(void)
{
	int ret;

	/* B.A.T.M.A.N. V echo location protocol packet  */
	ret = batadv_recv_handler_register(BATADV_ELP,
					   batadv_v_elp_packet_recv);
	if (ret < 0)
		return ret;

	ret = batadv_recv_handler_register(BATADV_OGM2,
					   batadv_v_ogm_packet_recv);
	if (ret < 0)
		goto elp_unregister;

	ret = batadv_algo_register(&batadv_batman_v);
	if (ret < 0)
		goto ogm_unregister;

	return ret;

ogm_unregister:
	batadv_recv_handler_unregister(BATADV_OGM2);

elp_unregister:
	batadv_recv_handler_unregister(BATADV_ELP);

	return ret;
}