summaryrefslogtreecommitdiff
path: root/net/batman-adv/bat_v_ogm.c
blob: 033639df96d854d53764bd54a18a6a66ae00d477 (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
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) B.A.T.M.A.N. contributors:
 *
 * Antonio Quartulli
 */

#include "bat_v_ogm.h"
#include "main.h"

#include <linux/atomic.h>
#include <linux/byteorder/generic.h>
#include <linux/container_of.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/minmax.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/prandom.h>
#include <linux/random.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <uapi/linux/batadv_packet.h>

#include "bat_algo.h"
#include "hard-interface.h"
#include "hash.h"
#include "log.h"
#include "originator.h"
#include "routing.h"
#include "send.h"
#include "translation-table.h"
#include "tvlv.h"

/**
 * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
 * @bat_priv: the bat priv with all the soft interface information
 * @addr: the address of the originator
 *
 * Return: the orig_node corresponding to the specified address. If such an
 * object does not exist, it is allocated here. In case of allocation failure
 * returns NULL.
 */
struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
					       const u8 *addr)
{
	struct batadv_orig_node *orig_node;
	int hash_added;

	orig_node = batadv_orig_hash_find(bat_priv, addr);
	if (orig_node)
		return orig_node;

	orig_node = batadv_orig_node_new(bat_priv, addr);
	if (!orig_node)
		return NULL;

	kref_get(&orig_node->refcount);
	hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
				     batadv_choose_orig, orig_node,
				     &orig_node->hash_entry);
	if (hash_added != 0) {
		/* remove refcnt for newly created orig_node and hash entry */
		batadv_orig_node_put(orig_node);
		batadv_orig_node_put(orig_node);
		orig_node = NULL;
	}

	return orig_node;
}

/**
 * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
 * @hard_iface: the interface to use to send the OGM
 */
static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
{
	unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;

	/* msecs * [0.9, 1.1] */
	msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
			   msecs_to_jiffies(msecs / 1000));
}

/**
 * batadv_v_ogm_start_timer() - restart the OGM sending timer
 * @bat_priv: the bat priv with all the soft interface information
 */
static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
{
	unsigned long msecs;
	/* this function may be invoked in different contexts (ogm rescheduling
	 * or hard_iface activation), but the work timer should not be reset
	 */
	if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
		return;

	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
	msecs += prandom_u32_max(2 * BATADV_JITTER);
	queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
			   msecs_to_jiffies(msecs));
}

/**
 * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
 * @skb: the OGM to send
 * @hard_iface: the interface to use to send the OGM
 */
static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
				    struct batadv_hard_iface *hard_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);

	if (hard_iface->if_status != BATADV_IF_ACTIVE)
		return;

	batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
	batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
			   skb->len + ETH_HLEN);

	batadv_send_broadcast_skb(skb, hard_iface);
}

/**
 * batadv_v_ogm_len() - OGMv2 packet length
 * @skb: the OGM to check
 *
 * Return: Length of the given OGMv2 packet, including tvlv length, excluding
 * ethernet header length.
 */
static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
{
	struct batadv_ogm2_packet *ogm_packet;

	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
	return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
}

/**
 * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
 * @skb: the OGM to check
 * @hard_iface: the interface to use to send the OGM
 *
 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 *
 * Return: True, if the given OGMv2 packet still fits, false otherwise.
 */
static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
				    struct batadv_hard_iface *hard_iface)
{
	unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
				 BATADV_MAX_AGGREGATION_BYTES);
	unsigned int ogm_len = batadv_v_ogm_len(skb);

	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);

	return hard_iface->bat_v.aggr_len + ogm_len <= max;
}

/**
 * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
 * @hard_iface: the interface holding the aggregation queue
 *
 * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
 *
 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 */
static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
{
	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);

	__skb_queue_purge(&hard_iface->bat_v.aggr_list);
	hard_iface->bat_v.aggr_len = 0;
}

/**
 * batadv_v_ogm_aggr_send() - flush & send aggregation queue
 * @hard_iface: the interface with the aggregation queue to flush
 *
 * Aggregates all OGMv2 packets currently in the aggregation queue into a
 * single OGMv2 packet and transmits this aggregate.
 *
 * The aggregation queue is empty after this call.
 *
 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
 */
static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
{
	unsigned int aggr_len = hard_iface->bat_v.aggr_len;
	struct sk_buff *skb_aggr;
	unsigned int ogm_len;
	struct sk_buff *skb;

	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);

	if (!aggr_len)
		return;

	skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
	if (!skb_aggr) {
		batadv_v_ogm_aggr_list_free(hard_iface);
		return;
	}

	skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
	skb_reset_network_header(skb_aggr);

	while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
		hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);

		ogm_len = batadv_v_ogm_len(skb);
		skb_put_data(skb_aggr, skb->data, ogm_len);

		consume_skb(skb);
	}

	batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
}

/**
 * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
 * @skb: the OGM to queue
 * @hard_iface: the interface to queue the OGM on
 */
static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
				     struct batadv_hard_iface *hard_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);

	if (!atomic_read(&bat_priv->aggregated_ogms)) {
		batadv_v_ogm_send_to_if(skb, hard_iface);
		return;
	}

	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
	if (!batadv_v_ogm_queue_left(skb, hard_iface))
		batadv_v_ogm_aggr_send(hard_iface);

	hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
	__skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
}

/**
 * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
 * @bat_priv: the bat priv with all the soft interface information
 */
static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
{
	struct batadv_hard_iface *hard_iface;
	struct batadv_ogm2_packet *ogm_packet;
	struct sk_buff *skb, *skb_tmp;
	unsigned char *ogm_buff;
	int ogm_buff_len;
	u16 tvlv_len = 0;
	int ret;

	lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);

	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
		goto out;

	ogm_buff = bat_priv->bat_v.ogm_buff;
	ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
	/* tt changes have to be committed before the tvlv data is
	 * appended as it may alter the tt tvlv container
	 */
	batadv_tt_local_commit_changes(bat_priv);
	tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
						    &ogm_buff_len,
						    BATADV_OGM2_HLEN);

	bat_priv->bat_v.ogm_buff = ogm_buff;
	bat_priv->bat_v.ogm_buff_len = ogm_buff_len;

	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
	if (!skb)
		goto reschedule;

	skb_reserve(skb, ETH_HLEN);
	skb_put_data(skb, ogm_buff, ogm_buff_len);

	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
	ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
	atomic_inc(&bat_priv->bat_v.ogm_seqno);
	ogm_packet->tvlv_len = htons(tvlv_len);

	/* broadcast on every interface */
	rcu_read_lock();
	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
		if (hard_iface->soft_iface != bat_priv->soft_iface)
			continue;

		if (!kref_get_unless_zero(&hard_iface->refcount))
			continue;

		ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
		if (ret) {
			char *type;

			switch (ret) {
			case BATADV_HARDIF_BCAST_NORECIPIENT:
				type = "no neighbor";
				break;
			case BATADV_HARDIF_BCAST_DUPFWD:
				type = "single neighbor is source";
				break;
			case BATADV_HARDIF_BCAST_DUPORIG:
				type = "single neighbor is originator";
				break;
			default:
				type = "unknown";
			}

			batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
				   hard_iface->net_dev->name, type);

			batadv_hardif_put(hard_iface);
			continue;
		}

		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
			   ogm_packet->orig, ntohl(ogm_packet->seqno),
			   ntohl(ogm_packet->throughput), ogm_packet->ttl,
			   hard_iface->net_dev->name,
			   hard_iface->net_dev->dev_addr);

		/* this skb gets consumed by batadv_v_ogm_send_to_if() */
		skb_tmp = skb_clone(skb, GFP_ATOMIC);
		if (!skb_tmp) {
			batadv_hardif_put(hard_iface);
			break;
		}

		batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
		batadv_hardif_put(hard_iface);
	}
	rcu_read_unlock();

	consume_skb(skb);

reschedule:
	batadv_v_ogm_start_timer(bat_priv);
out:
	return;
}

/**
 * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
 * @work: work queue item
 */
static void batadv_v_ogm_send(struct work_struct *work)
{
	struct batadv_priv_bat_v *bat_v;
	struct batadv_priv *bat_priv;

	bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
	bat_priv = container_of(bat_v, struct batadv_priv, bat_v);

	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
	batadv_v_ogm_send_softif(bat_priv);
	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}

/**
 * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
 * @work: work queue item
 *
 * Emits aggregated OGM messages in regular intervals.
 */
void batadv_v_ogm_aggr_work(struct work_struct *work)
{
	struct batadv_hard_iface_bat_v *batv;
	struct batadv_hard_iface *hard_iface;

	batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
	hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);

	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
	batadv_v_ogm_aggr_send(hard_iface);
	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);

	batadv_v_ogm_start_queue_timer(hard_iface);
}

/**
 * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
 * @hard_iface: the interface to prepare
 *
 * Takes care of scheduling its own OGM sending routine for this interface.
 *
 * Return: 0 on success or a negative error code otherwise
 */
int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);

	batadv_v_ogm_start_queue_timer(hard_iface);
	batadv_v_ogm_start_timer(bat_priv);

	return 0;
}

/**
 * batadv_v_ogm_iface_disable() - release OGM interface private resources
 * @hard_iface: interface for which the resources have to be released
 */
void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
{
	cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);

	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
	batadv_v_ogm_aggr_list_free(hard_iface);
	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
}

/**
 * batadv_v_ogm_primary_iface_set() - set a new primary interface
 * @primary_iface: the new primary interface
 */
void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
{
	struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
	struct batadv_ogm2_packet *ogm_packet;

	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
	if (!bat_priv->bat_v.ogm_buff)
		goto unlock;

	ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
	ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);

unlock:
	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}

/**
 * batadv_v_forward_penalty() - apply a penalty to the throughput metric
 *  forwarded with B.A.T.M.A.N. V OGMs
 * @bat_priv: the bat priv with all the soft interface information
 * @if_incoming: the interface where the OGM has been received
 * @if_outgoing: the interface where the OGM has to be forwarded to
 * @throughput: the current throughput
 *
 * Apply a penalty on the current throughput metric value based on the
 * characteristic of the interface where the OGM has been received.
 *
 * Initially the per hardif hop penalty is applied to the throughput. After
 * that the return value is then computed as follows:
 * - throughput * 50%          if the incoming and outgoing interface are the
 *                             same WiFi interface and the throughput is above
 *                             1MBit/s
 * - throughput                if the outgoing interface is the default
 *                             interface (i.e. this OGM is processed for the
 *                             internal table and not forwarded)
 * - throughput * node hop penalty  otherwise
 *
 * Return: the penalised throughput metric.
 */
static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
				    struct batadv_hard_iface *if_incoming,
				    struct batadv_hard_iface *if_outgoing,
				    u32 throughput)
{
	int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
	int hop_penalty = atomic_read(&bat_priv->hop_penalty);
	int hop_penalty_max = BATADV_TQ_MAX_VALUE;

	/* Apply per hardif hop penalty */
	throughput = throughput * (hop_penalty_max - if_hop_penalty) /
		     hop_penalty_max;

	/* Don't apply hop penalty in default originator table. */
	if (if_outgoing == BATADV_IF_DEFAULT)
		return throughput;

	/* Forwarding on the same WiFi interface cuts the throughput in half
	 * due to the store & forward characteristics of WIFI.
	 * Very low throughput values are the exception.
	 */
	if (throughput > 10 &&
	    if_incoming == if_outgoing &&
	    !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
		return throughput / 2;

	/* hop penalty of 255 equals 100% */
	return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
}

/**
 * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
 *  outgoing interface
 * @bat_priv: the bat priv with all the soft interface information
 * @ogm_received: previously received OGM to be forwarded
 * @orig_node: the originator which has been updated
 * @neigh_node: the neigh_node through with the OGM has been received
 * @if_incoming: the interface on which this OGM was received on
 * @if_outgoing: the interface to which the OGM has to be forwarded to
 *
 * Forward an OGM to an interface after having altered the throughput metric and
 * the TTL value contained in it. The original OGM isn't modified.
 */
static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
				 const struct batadv_ogm2_packet *ogm_received,
				 struct batadv_orig_node *orig_node,
				 struct batadv_neigh_node *neigh_node,
				 struct batadv_hard_iface *if_incoming,
				 struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
	struct batadv_orig_ifinfo *orig_ifinfo = NULL;
	struct batadv_neigh_node *router = NULL;
	struct batadv_ogm2_packet *ogm_forward;
	unsigned char *skb_buff;
	struct sk_buff *skb;
	size_t packet_len;
	u16 tvlv_len;

	/* only forward for specific interfaces, not for the default one. */
	if (if_outgoing == BATADV_IF_DEFAULT)
		goto out;

	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
	if (!orig_ifinfo)
		goto out;

	/* acquire possibly updated router */
	router = batadv_orig_router_get(orig_node, if_outgoing);

	/* strict rule: forward packets coming from the best next hop only */
	if (neigh_node != router)
		goto out;

	/* don't forward the same seqno twice on one interface */
	if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
		goto out;

	orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);

	if (ogm_received->ttl <= 1) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
		goto out;
	}

	neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
	if (!neigh_ifinfo)
		goto out;

	tvlv_len = ntohs(ogm_received->tvlv_len);

	packet_len = BATADV_OGM2_HLEN + tvlv_len;
	skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
					ETH_HLEN + packet_len);
	if (!skb)
		goto out;

	skb_reserve(skb, ETH_HLEN);
	skb_buff = skb_put_data(skb, ogm_received, packet_len);

	/* apply forward penalty */
	ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
	ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
	ogm_forward->ttl--;

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
		   if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
		   ogm_forward->ttl, if_incoming->net_dev->name);

	batadv_v_ogm_queue_on_if(skb, if_outgoing);

out:
	batadv_orig_ifinfo_put(orig_ifinfo);
	batadv_neigh_node_put(router);
	batadv_neigh_ifinfo_put(neigh_ifinfo);
}

/**
 * batadv_v_ogm_metric_update() - update route metric based on OGM
 * @bat_priv: the bat priv with all the soft interface information
 * @ogm2: OGM2 structure
 * @orig_node: Originator structure for which the OGM has been received
 * @neigh_node: the neigh_node through with the OGM has been received
 * @if_incoming: the interface where this packet was received
 * @if_outgoing: the interface for which the packet should be considered
 *
 * Return:
 *  1  if the OGM is new,
 *  0  if it is not new but valid,
 *  <0 on error (e.g. old OGM)
 */
static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
				      const struct batadv_ogm2_packet *ogm2,
				      struct batadv_orig_node *orig_node,
				      struct batadv_neigh_node *neigh_node,
				      struct batadv_hard_iface *if_incoming,
				      struct batadv_hard_iface *if_outgoing)
{
	struct batadv_orig_ifinfo *orig_ifinfo;
	struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
	bool protection_started = false;
	int ret = -EINVAL;
	u32 path_throughput;
	s32 seq_diff;

	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
	if (!orig_ifinfo)
		goto out;

	seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;

	if (!hlist_empty(&orig_node->neigh_list) &&
	    batadv_window_protected(bat_priv, seq_diff,
				    BATADV_OGM_MAX_AGE,
				    &orig_ifinfo->batman_seqno_reset,
				    &protection_started)) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Drop packet: packet within window protection time from %pM\n",
			   ogm2->orig);
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Last reset: %ld, %ld\n",
			   orig_ifinfo->batman_seqno_reset, jiffies);
		goto out;
	}

	/* drop packets with old seqnos, however accept the first packet after
	 * a host has been rebooted.
	 */
	if (seq_diff < 0 && !protection_started)
		goto out;

	neigh_node->last_seen = jiffies;

	orig_node->last_seen = jiffies;

	orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
	orig_ifinfo->last_ttl = ogm2->ttl;

	neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
	if (!neigh_ifinfo)
		goto out;

	path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
						   if_outgoing,
						   ntohl(ogm2->throughput));
	neigh_ifinfo->bat_v.throughput = path_throughput;
	neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
	neigh_ifinfo->last_ttl = ogm2->ttl;

	if (seq_diff > 0 || protection_started)
		ret = 1;
	else
		ret = 0;
out:
	batadv_orig_ifinfo_put(orig_ifinfo);
	batadv_neigh_ifinfo_put(neigh_ifinfo);

	return ret;
}

/**
 * batadv_v_ogm_route_update() - update routes based on OGM
 * @bat_priv: the bat priv with all the soft interface information
 * @ethhdr: the Ethernet header of the OGM2
 * @ogm2: OGM2 structure
 * @orig_node: Originator structure for which the OGM has been received
 * @neigh_node: the neigh_node through with the OGM has been received
 * @if_incoming: the interface where this packet was received
 * @if_outgoing: the interface for which the packet should be considered
 *
 * Return: true if the packet should be forwarded, false otherwise
 */
static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
				      const struct ethhdr *ethhdr,
				      const struct batadv_ogm2_packet *ogm2,
				      struct batadv_orig_node *orig_node,
				      struct batadv_neigh_node *neigh_node,
				      struct batadv_hard_iface *if_incoming,
				      struct batadv_hard_iface *if_outgoing)
{
	struct batadv_neigh_node *router = NULL;
	struct batadv_orig_node *orig_neigh_node;
	struct batadv_neigh_node *orig_neigh_router = NULL;
	struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
	u32 router_throughput, neigh_throughput;
	u32 router_last_seqno;
	u32 neigh_last_seqno;
	s32 neigh_seq_diff;
	bool forward = false;

	orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
	if (!orig_neigh_node)
		goto out;

	orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
						   if_outgoing);

	/* drop packet if sender is not a direct neighbor and if we
	 * don't route towards it
	 */
	router = batadv_orig_router_get(orig_node, if_outgoing);
	if (router && router->orig_node != orig_node && !orig_neigh_router) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Drop packet: OGM via unknown neighbor!\n");
		goto out;
	}

	/* Mark the OGM to be considered for forwarding, and update routes
	 * if needed.
	 */
	forward = true;

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Searching and updating originator entry of received packet\n");

	/* if this neighbor already is our next hop there is nothing
	 * to change
	 */
	if (router == neigh_node)
		goto out;

	/* don't consider neighbours with worse throughput.
	 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
	 * the last received seqno from our best next hop.
	 */
	if (router) {
		router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
		neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);

		/* if these are not allocated, something is wrong. */
		if (!router_ifinfo || !neigh_ifinfo)
			goto out;

		neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
		router_last_seqno = router_ifinfo->bat_v.last_seqno;
		neigh_seq_diff = neigh_last_seqno - router_last_seqno;
		router_throughput = router_ifinfo->bat_v.throughput;
		neigh_throughput = neigh_ifinfo->bat_v.throughput;

		if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
		    router_throughput >= neigh_throughput)
			goto out;
	}

	batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
out:
	batadv_neigh_node_put(router);
	batadv_neigh_node_put(orig_neigh_router);
	batadv_orig_node_put(orig_neigh_node);
	batadv_neigh_ifinfo_put(router_ifinfo);
	batadv_neigh_ifinfo_put(neigh_ifinfo);

	return forward;
}

/**
 * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
 * @bat_priv: the bat priv with all the soft interface information
 * @ethhdr: the Ethernet header of the OGM2
 * @ogm2: OGM2 structure
 * @orig_node: Originator structure for which the OGM has been received
 * @neigh_node: the neigh_node through with the OGM has been received
 * @if_incoming: the interface where this packet was received
 * @if_outgoing: the interface for which the packet should be considered
 */
static void
batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
			       const struct ethhdr *ethhdr,
			       const struct batadv_ogm2_packet *ogm2,
			       struct batadv_orig_node *orig_node,
			       struct batadv_neigh_node *neigh_node,
			       struct batadv_hard_iface *if_incoming,
			       struct batadv_hard_iface *if_outgoing)
{
	int seqno_age;
	bool forward;

	/* first, update the metric with according sanity checks */
	seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
					       neigh_node, if_incoming,
					       if_outgoing);

	/* outdated sequence numbers are to be discarded */
	if (seqno_age < 0)
		return;

	/* only unknown & newer OGMs contain TVLVs we are interested in */
	if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
		batadv_tvlv_containers_process(bat_priv, true, orig_node,
					       NULL, NULL,
					       (unsigned char *)(ogm2 + 1),
					       ntohs(ogm2->tvlv_len));

	/* if the metric update went through, update routes if needed */
	forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
					    neigh_node, if_incoming,
					    if_outgoing);

	/* if the routes have been processed correctly, check and forward */
	if (forward)
		batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
				     if_incoming, if_outgoing);
}

/**
 * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
 * @buff_pos: current position in the skb
 * @packet_len: total length of the skb
 * @ogm2_packet: potential OGM2 in buffer
 *
 * Return: true if there is enough space for another OGM, false otherwise.
 */
static bool
batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
			 const struct batadv_ogm2_packet *ogm2_packet)
{
	int next_buff_pos = 0;

	/* check if there is enough space for the header */
	next_buff_pos += buff_pos + sizeof(*ogm2_packet);
	if (next_buff_pos > packet_len)
		return false;

	/* check if there is enough space for the optional TVLV */
	next_buff_pos += ntohs(ogm2_packet->tvlv_len);

	return (next_buff_pos <= packet_len) &&
	       (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
}

/**
 * batadv_v_ogm_process() - process an incoming batman v OGM
 * @skb: the skb containing the OGM
 * @ogm_offset: offset to the OGM which should be processed (for aggregates)
 * @if_incoming: the interface where this packet was received
 */
static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
				 struct batadv_hard_iface *if_incoming)
{
	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	struct ethhdr *ethhdr;
	struct batadv_orig_node *orig_node = NULL;
	struct batadv_hardif_neigh_node *hardif_neigh = NULL;
	struct batadv_neigh_node *neigh_node = NULL;
	struct batadv_hard_iface *hard_iface;
	struct batadv_ogm2_packet *ogm_packet;
	u32 ogm_throughput, link_throughput, path_throughput;
	int ret;

	ethhdr = eth_hdr(skb);
	ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);

	ogm_throughput = ntohl(ogm_packet->throughput);

	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
		   "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
		   ethhdr->h_source, if_incoming->net_dev->name,
		   if_incoming->net_dev->dev_addr, ogm_packet->orig,
		   ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
		   ogm_packet->version, ntohs(ogm_packet->tvlv_len));

	if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Drop packet: originator packet from ourself\n");
		return;
	}

	/* If the throughput metric is 0, immediately drop the packet. No need
	 * to create orig_node / neigh_node for an unusable route.
	 */
	if (ogm_throughput == 0) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Drop packet: originator packet with throughput metric of 0\n");
		return;
	}

	/* require ELP packets be to received from this neighbor first */
	hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
	if (!hardif_neigh) {
		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
			   "Drop packet: OGM via unknown neighbor!\n");
		goto out;
	}

	orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
	if (!orig_node)
		goto out;

	neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
						     ethhdr->h_source);
	if (!neigh_node)
		goto out;

	/* Update the received throughput metric to match the link
	 * characteristic:
	 *  - If this OGM traveled one hop so far (emitted by single hop
	 *    neighbor) the path throughput metric equals the link throughput.
	 *  - For OGMs traversing more than hop the path throughput metric is
	 *    the smaller of the path throughput and the link throughput.
	 */
	link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
	path_throughput = min_t(u32, link_throughput, ogm_throughput);
	ogm_packet->throughput = htonl(path_throughput);

	batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
				       neigh_node, if_incoming,
				       BATADV_IF_DEFAULT);

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

		if (hard_iface->soft_iface != bat_priv->soft_iface)
			continue;

		if (!kref_get_unless_zero(&hard_iface->refcount))
			continue;

		ret = batadv_hardif_no_broadcast(hard_iface,
						 ogm_packet->orig,
						 hardif_neigh->orig);

		if (ret) {
			char *type;

			switch (ret) {
			case BATADV_HARDIF_BCAST_NORECIPIENT:
				type = "no neighbor";
				break;
			case BATADV_HARDIF_BCAST_DUPFWD:
				type = "single neighbor is source";
				break;
			case BATADV_HARDIF_BCAST_DUPORIG:
				type = "single neighbor is originator";
				break;
			default:
				type = "unknown";
			}

			batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
				   ogm_packet->orig, hard_iface->net_dev->name,
				   type);

			batadv_hardif_put(hard_iface);
			continue;
		}

		batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
					       orig_node, neigh_node,
					       if_incoming, hard_iface);

		batadv_hardif_put(hard_iface);
	}
	rcu_read_unlock();
out:
	batadv_orig_node_put(orig_node);
	batadv_neigh_node_put(neigh_node);
	batadv_hardif_neigh_put(hardif_neigh);
}

/**
 * batadv_v_ogm_packet_recv() - OGM2 receiving handler
 * @skb: the received OGM
 * @if_incoming: the interface where this OGM has been received
 *
 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
 * (without freeing the skb) on failure
 */
int batadv_v_ogm_packet_recv(struct sk_buff *skb,
			     struct batadv_hard_iface *if_incoming)
{
	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
	struct batadv_ogm2_packet *ogm_packet;
	struct ethhdr *ethhdr = eth_hdr(skb);
	int ogm_offset;
	u8 *packet_pos;
	int ret = NET_RX_DROP;

	/* did we receive a OGM2 packet on an interface that does not have
	 * B.A.T.M.A.N. V enabled ?
	 */
	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
		goto free_skb;

	if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
		goto free_skb;

	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
		goto free_skb;

	batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
	batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
			   skb->len + ETH_HLEN);

	ogm_offset = 0;
	ogm_packet = (struct batadv_ogm2_packet *)skb->data;

	while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
					ogm_packet)) {
		batadv_v_ogm_process(skb, ogm_offset, if_incoming);

		ogm_offset += BATADV_OGM2_HLEN;
		ogm_offset += ntohs(ogm_packet->tvlv_len);

		packet_pos = skb->data + ogm_offset;
		ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
	}

	ret = NET_RX_SUCCESS;

free_skb:
	if (ret == NET_RX_SUCCESS)
		consume_skb(skb);
	else
		kfree_skb(skb);

	return ret;
}

/**
 * batadv_v_ogm_init() - initialise the OGM2 engine
 * @bat_priv: the bat priv with all the soft interface information
 *
 * Return: 0 on success or a negative error code in case of failure
 */
int batadv_v_ogm_init(struct batadv_priv *bat_priv)
{
	struct batadv_ogm2_packet *ogm_packet;
	unsigned char *ogm_buff;
	u32 random_seqno;

	bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
	ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
	if (!ogm_buff)
		return -ENOMEM;

	bat_priv->bat_v.ogm_buff = ogm_buff;
	ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
	ogm_packet->packet_type = BATADV_OGM2;
	ogm_packet->version = BATADV_COMPAT_VERSION;
	ogm_packet->ttl = BATADV_TTL;
	ogm_packet->flags = BATADV_NO_FLAGS;
	ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);

	/* randomize initial seqno to avoid collision */
	get_random_bytes(&random_seqno, sizeof(random_seqno));
	atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
	INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);

	mutex_init(&bat_priv->bat_v.ogm_buff_mutex);

	return 0;
}

/**
 * batadv_v_ogm_free() - free OGM private resources
 * @bat_priv: the bat priv with all the soft interface information
 */
void batadv_v_ogm_free(struct batadv_priv *bat_priv)
{
	cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);

	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);

	kfree(bat_priv->bat_v.ogm_buff);
	bat_priv->bat_v.ogm_buff = NULL;
	bat_priv->bat_v.ogm_buff_len = 0;

	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
}