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
|
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2007-2017 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "send.h"
#include "main.h"
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/gfp.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/printk.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/workqueue.h>
#include "distributed-arp-table.h"
#include "fragmentation.h"
#include "gateway_client.h"
#include "hard-interface.h"
#include "log.h"
#include "network-coding.h"
#include "originator.h"
#include "routing.h"
#include "soft-interface.h"
#include "translation-table.h"
static void batadv_send_outstanding_bcast_packet(struct work_struct *work);
/**
* batadv_send_skb_packet() - send an already prepared packet
* @skb: the packet to send
* @hard_iface: the interface to use to send the broadcast packet
* @dst_addr: the payload destination
*
* Send out an already prepared packet to the given neighbor or broadcast it
* using the specified interface. Either hard_iface or neigh_node must be not
* NULL.
* If neigh_node is NULL, then the packet is broadcasted using hard_iface,
* otherwise it is sent as unicast to the given neighbor.
*
* Regardless of the return value, the skb is consumed.
*
* Return: A negative errno code is returned on a failure. A success does not
* guarantee the frame will be transmitted as it may be dropped due
* to congestion or traffic shaping.
*/
int batadv_send_skb_packet(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface,
const u8 *dst_addr)
{
struct batadv_priv *bat_priv;
struct ethhdr *ethhdr;
int ret;
bat_priv = netdev_priv(hard_iface->soft_iface);
if (hard_iface->if_status != BATADV_IF_ACTIVE)
goto send_skb_err;
if (unlikely(!hard_iface->net_dev))
goto send_skb_err;
if (!(hard_iface->net_dev->flags & IFF_UP)) {
pr_warn("Interface %s is not up - can't send packet via that interface!\n",
hard_iface->net_dev->name);
goto send_skb_err;
}
/* push to the ethernet header. */
if (batadv_skb_head_push(skb, ETH_HLEN) < 0)
goto send_skb_err;
skb_reset_mac_header(skb);
ethhdr = eth_hdr(skb);
ether_addr_copy(ethhdr->h_source, hard_iface->net_dev->dev_addr);
ether_addr_copy(ethhdr->h_dest, dst_addr);
ethhdr->h_proto = htons(ETH_P_BATMAN);
skb_set_network_header(skb, ETH_HLEN);
skb->protocol = htons(ETH_P_BATMAN);
skb->dev = hard_iface->net_dev;
/* Save a clone of the skb to use when decoding coded packets */
batadv_nc_skb_store_for_decoding(bat_priv, skb);
/* dev_queue_xmit() returns a negative result on error. However on
* congestion and traffic shaping, it drops and returns NET_XMIT_DROP
* (which is > 0). This will not be treated as an error.
*/
ret = dev_queue_xmit(skb);
return net_xmit_eval(ret);
send_skb_err:
kfree_skb(skb);
return NET_XMIT_DROP;
}
int batadv_send_broadcast_skb(struct sk_buff *skb,
struct batadv_hard_iface *hard_iface)
{
return batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
}
int batadv_send_unicast_skb(struct sk_buff *skb,
struct batadv_neigh_node *neigh)
{
#ifdef CONFIG_BATMAN_ADV_BATMAN_V
struct batadv_hardif_neigh_node *hardif_neigh;
#endif
int ret;
ret = batadv_send_skb_packet(skb, neigh->if_incoming, neigh->addr);
#ifdef CONFIG_BATMAN_ADV_BATMAN_V
hardif_neigh = batadv_hardif_neigh_get(neigh->if_incoming, neigh->addr);
if (hardif_neigh && ret != NET_XMIT_DROP)
hardif_neigh->bat_v.last_unicast_tx = jiffies;
if (hardif_neigh)
batadv_hardif_neigh_put(hardif_neigh);
#endif
return ret;
}
/**
* batadv_send_skb_to_orig() - Lookup next-hop and transmit skb.
* @skb: Packet to be transmitted.
* @orig_node: Final destination of the packet.
* @recv_if: Interface used when receiving the packet (can be NULL).
*
* Looks up the best next-hop towards the passed originator and passes the
* skb on for preparation of MAC header. If the packet originated from this
* host, NULL can be passed as recv_if and no interface alternating is
* attempted.
*
* Return: negative errno code on a failure, -EINPROGRESS if the skb is
* buffered for later transmit or the NET_XMIT status returned by the
* lower routine if the packet has been passed down.
*/
int batadv_send_skb_to_orig(struct sk_buff *skb,
struct batadv_orig_node *orig_node,
struct batadv_hard_iface *recv_if)
{
struct batadv_priv *bat_priv = orig_node->bat_priv;
struct batadv_neigh_node *neigh_node;
int ret;
/* batadv_find_router() increases neigh_nodes refcount if found. */
neigh_node = batadv_find_router(bat_priv, orig_node, recv_if);
if (!neigh_node) {
ret = -EINVAL;
goto free_skb;
}
/* Check if the skb is too large to send in one piece and fragment
* it if needed.
*/
if (atomic_read(&bat_priv->fragmentation) &&
skb->len > neigh_node->if_incoming->net_dev->mtu) {
/* Fragment and send packet. */
ret = batadv_frag_send_packet(skb, orig_node, neigh_node);
/* skb was consumed */
skb = NULL;
goto put_neigh_node;
}
/* try to network code the packet, if it is received on an interface
* (i.e. being forwarded). If the packet originates from this node or if
* network coding fails, then send the packet as usual.
*/
if (recv_if && batadv_nc_skb_forward(skb, neigh_node))
ret = -EINPROGRESS;
else
ret = batadv_send_unicast_skb(skb, neigh_node);
/* skb was consumed */
skb = NULL;
put_neigh_node:
batadv_neigh_node_put(neigh_node);
free_skb:
kfree_skb(skb);
return ret;
}
/**
* batadv_send_skb_push_fill_unicast() - extend the buffer and initialize the
* common fields for unicast packets
* @skb: the skb carrying the unicast header to initialize
* @hdr_size: amount of bytes to push at the beginning of the skb
* @orig_node: the destination node
*
* Return: false if the buffer extension was not possible or true otherwise.
*/
static bool
batadv_send_skb_push_fill_unicast(struct sk_buff *skb, int hdr_size,
struct batadv_orig_node *orig_node)
{
struct batadv_unicast_packet *unicast_packet;
u8 ttvn = (u8)atomic_read(&orig_node->last_ttvn);
if (batadv_skb_head_push(skb, hdr_size) < 0)
return false;
unicast_packet = (struct batadv_unicast_packet *)skb->data;
unicast_packet->version = BATADV_COMPAT_VERSION;
/* batman packet type: unicast */
unicast_packet->packet_type = BATADV_UNICAST;
/* set unicast ttl */
unicast_packet->ttl = BATADV_TTL;
/* copy the destination for faster routing */
ether_addr_copy(unicast_packet->dest, orig_node->orig);
/* set the destination tt version number */
unicast_packet->ttvn = ttvn;
return true;
}
/**
* batadv_send_skb_prepare_unicast() - encapsulate an skb with a unicast header
* @skb: the skb containing the payload to encapsulate
* @orig_node: the destination node
*
* Return: false if the payload could not be encapsulated or true otherwise.
*/
static bool batadv_send_skb_prepare_unicast(struct sk_buff *skb,
struct batadv_orig_node *orig_node)
{
size_t uni_size = sizeof(struct batadv_unicast_packet);
return batadv_send_skb_push_fill_unicast(skb, uni_size, orig_node);
}
/**
* batadv_send_skb_prepare_unicast_4addr() - encapsulate an skb with a
* unicast 4addr header
* @bat_priv: the bat priv with all the soft interface information
* @skb: the skb containing the payload to encapsulate
* @orig: the destination node
* @packet_subtype: the unicast 4addr packet subtype to use
*
* Return: false if the payload could not be encapsulated or true otherwise.
*/
bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
struct sk_buff *skb,
struct batadv_orig_node *orig,
int packet_subtype)
{
struct batadv_hard_iface *primary_if;
struct batadv_unicast_4addr_packet *uc_4addr_packet;
bool ret = false;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto out;
/* Pull the header space and fill the unicast_packet substructure.
* We can do that because the first member of the uc_4addr_packet
* is of type struct unicast_packet
*/
if (!batadv_send_skb_push_fill_unicast(skb, sizeof(*uc_4addr_packet),
orig))
goto out;
uc_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;
uc_4addr_packet->u.packet_type = BATADV_UNICAST_4ADDR;
ether_addr_copy(uc_4addr_packet->src, primary_if->net_dev->dev_addr);
uc_4addr_packet->subtype = packet_subtype;
uc_4addr_packet->reserved = 0;
ret = true;
out:
if (primary_if)
batadv_hardif_put(primary_if);
return ret;
}
/**
* batadv_send_skb_unicast() - encapsulate and send an skb via unicast
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @packet_type: the batman unicast packet type to use
* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
* 4addr packets)
* @orig_node: the originator to send the packet to
* @vid: the vid to be used to search the translation table
*
* Wrap the given skb into a batman-adv unicast or unicast-4addr header
* depending on whether BATADV_UNICAST or BATADV_UNICAST_4ADDR was supplied
* as packet_type. Then send this frame to the given orig_node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_unicast(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype,
struct batadv_orig_node *orig_node,
unsigned short vid)
{
struct batadv_unicast_packet *unicast_packet;
struct ethhdr *ethhdr;
int ret = NET_XMIT_DROP;
if (!orig_node)
goto out;
switch (packet_type) {
case BATADV_UNICAST:
if (!batadv_send_skb_prepare_unicast(skb, orig_node))
goto out;
break;
case BATADV_UNICAST_4ADDR:
if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb,
orig_node,
packet_subtype))
goto out;
break;
default:
/* this function supports UNICAST and UNICAST_4ADDR only. It
* should never be invoked with any other packet type
*/
goto out;
}
/* skb->data might have been reallocated by
* batadv_send_skb_prepare_unicast{,_4addr}()
*/
ethhdr = eth_hdr(skb);
unicast_packet = (struct batadv_unicast_packet *)skb->data;
/* inform the destination node that we are still missing a correct route
* for this client. The destination will receive this packet and will
* try to reroute it because the ttvn contained in the header is less
* than the current one
*/
if (batadv_tt_global_client_is_roaming(bat_priv, ethhdr->h_dest, vid))
unicast_packet->ttvn = unicast_packet->ttvn - 1;
ret = batadv_send_skb_to_orig(skb, orig_node, NULL);
/* skb was consumed */
skb = NULL;
out:
kfree_skb(skb);
return ret;
}
/**
* batadv_send_skb_via_tt_generic() - send an skb via TT lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @packet_type: the batman unicast packet type to use
* @packet_subtype: the unicast 4addr packet subtype (only relevant for unicast
* 4addr packets)
* @dst_hint: can be used to override the destination contained in the skb
* @vid: the vid to be used to search the translation table
*
* Look up the recipient node for the destination address in the ethernet
* header via the translation table. Wrap the given skb into a batman-adv
* unicast or unicast-4addr header depending on whether BATADV_UNICAST or
* BATADV_UNICAST_4ADDR was supplied as packet_type. Then send this frame
* to the according destination node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
struct sk_buff *skb, int packet_type,
int packet_subtype, u8 *dst_hint,
unsigned short vid)
{
struct ethhdr *ethhdr = (struct ethhdr *)skb->data;
struct batadv_orig_node *orig_node;
u8 *src, *dst;
int ret;
src = ethhdr->h_source;
dst = ethhdr->h_dest;
/* if we got an hint! let's send the packet to this client (if any) */
if (dst_hint) {
src = NULL;
dst = dst_hint;
}
orig_node = batadv_transtable_search(bat_priv, src, dst, vid);
ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
packet_subtype, orig_node, vid);
if (orig_node)
batadv_orig_node_put(orig_node);
return ret;
}
/**
* batadv_send_skb_via_gw() - send an skb via gateway lookup
* @bat_priv: the bat priv with all the soft interface information
* @skb: payload to send
* @vid: the vid to be used to search the translation table
*
* Look up the currently selected gateway. Wrap the given skb into a batman-adv
* unicast header and send this frame to this gateway node.
*
* Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
*/
int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
unsigned short vid)
{
struct batadv_orig_node *orig_node;
int ret;
orig_node = batadv_gw_get_selected_orig(bat_priv);
ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
BATADV_P_DATA, orig_node, vid);
if (orig_node)
batadv_orig_node_put(orig_node);
return ret;
}
/**
* batadv_forw_packet_free() - free a forwarding packet
* @forw_packet: The packet to free
* @dropped: whether the packet is freed because is is dropped
*
* This frees a forwarding packet and releases any resources it might
* have claimed.
*/
void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
bool dropped)
{
if (dropped)
kfree_skb(forw_packet->skb);
else
consume_skb(forw_packet->skb);
if (forw_packet->if_incoming)
batadv_hardif_put(forw_packet->if_incoming);
if (forw_packet->if_outgoing)
batadv_hardif_put(forw_packet->if_outgoing);
if (forw_packet->queue_left)
atomic_inc(forw_packet->queue_left);
kfree(forw_packet);
}
/**
* batadv_forw_packet_alloc() - allocate a forwarding packet
* @if_incoming: The (optional) if_incoming to be grabbed
* @if_outgoing: The (optional) if_outgoing to be grabbed
* @queue_left: The (optional) queue counter to decrease
* @bat_priv: The bat_priv for the mesh of this forw_packet
* @skb: The raw packet this forwarding packet shall contain
*
* Allocates a forwarding packet and tries to get a reference to the
* (optional) if_incoming, if_outgoing and queue_left. If queue_left
* is NULL then bat_priv is optional, too.
*
* Return: An allocated forwarding packet on success, NULL otherwise.
*/
struct batadv_forw_packet *
batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming,
struct batadv_hard_iface *if_outgoing,
atomic_t *queue_left,
struct batadv_priv *bat_priv,
struct sk_buff *skb)
{
struct batadv_forw_packet *forw_packet;
const char *qname;
if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) {
qname = "unknown";
if (queue_left == &bat_priv->bcast_queue_left)
qname = "bcast";
if (queue_left == &bat_priv->batman_queue_left)
qname = "batman";
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"%s queue is full\n", qname);
return NULL;
}
forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC);
if (!forw_packet)
goto err;
if (if_incoming)
kref_get(&if_incoming->refcount);
if (if_outgoing)
kref_get(&if_outgoing->refcount);
INIT_HLIST_NODE(&forw_packet->list);
INIT_HLIST_NODE(&forw_packet->cleanup_list);
forw_packet->skb = skb;
forw_packet->queue_left = queue_left;
forw_packet->if_incoming = if_incoming;
forw_packet->if_outgoing = if_outgoing;
forw_packet->num_packets = 0;
return forw_packet;
err:
if (queue_left)
atomic_inc(queue_left);
return NULL;
}
/**
* batadv_forw_packet_was_stolen() - check whether someone stole this packet
* @forw_packet: the forwarding packet to check
*
* This function checks whether the given forwarding packet was claimed by
* someone else for free().
*
* Return: True if someone stole it, false otherwise.
*/
static bool
batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet)
{
return !hlist_unhashed(&forw_packet->cleanup_list);
}
/**
* batadv_forw_packet_steal() - claim a forw_packet for free()
* @forw_packet: the forwarding packet to steal
* @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock)
*
* This function tries to steal a specific forw_packet from global
* visibility for the purpose of getting it for free(). That means
* the caller is *not* allowed to requeue it afterwards.
*
* Return: True if stealing was successful. False if someone else stole it
* before us.
*/
bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
spinlock_t *lock)
{
/* did purging routine steal it earlier? */
spin_lock_bh(lock);
if (batadv_forw_packet_was_stolen(forw_packet)) {
spin_unlock_bh(lock);
return false;
}
hlist_del_init(&forw_packet->list);
/* Just to spot misuse of this function */
hlist_add_fake(&forw_packet->cleanup_list);
spin_unlock_bh(lock);
return true;
}
/**
* batadv_forw_packet_list_steal() - claim a list of forward packets for free()
* @forw_list: the to be stolen forward packets
* @cleanup_list: a backup pointer, to be able to dispose the packet later
* @hard_iface: the interface to steal forward packets from
*
* This function claims responsibility to free any forw_packet queued on the
* given hard_iface. If hard_iface is NULL forwarding packets on all hard
* interfaces will be claimed.
*
* The packets are being moved from the forw_list to the cleanup_list and
* by that allows already running threads to notice the claiming.
*/
static void
batadv_forw_packet_list_steal(struct hlist_head *forw_list,
struct hlist_head *cleanup_list,
const struct batadv_hard_iface *hard_iface)
{
struct batadv_forw_packet *forw_packet;
struct hlist_node *safe_tmp_node;
hlist_for_each_entry_safe(forw_packet, safe_tmp_node,
forw_list, list) {
/* if purge_outstanding_packets() was called with an argument
* we delete only packets belonging to the given interface
*/
if (hard_iface &&
forw_packet->if_incoming != hard_iface &&
forw_packet->if_outgoing != hard_iface)
continue;
hlist_del(&forw_packet->list);
hlist_add_head(&forw_packet->cleanup_list, cleanup_list);
}
}
/**
* batadv_forw_packet_list_free() - free a list of forward packets
* @head: a list of to be freed forw_packets
*
* This function cancels the scheduling of any packet in the provided list,
* waits for any possibly running packet forwarding thread to finish and
* finally, safely frees this forward packet.
*
* This function might sleep.
*/
static void batadv_forw_packet_list_free(struct hlist_head *head)
{
struct batadv_forw_packet *forw_packet;
struct hlist_node *safe_tmp_node;
hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head,
cleanup_list) {
cancel_delayed_work_sync(&forw_packet->delayed_work);
hlist_del(&forw_packet->cleanup_list);
batadv_forw_packet_free(forw_packet, true);
}
}
/**
* batadv_forw_packet_queue() - try to queue a forwarding packet
* @forw_packet: the forwarding packet to queue
* @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock)
* @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list)
* @send_time: timestamp (jiffies) when the packet is to be sent
*
* This function tries to (re)queue a forwarding packet. Requeuing
* is prevented if the according interface is shutting down
* (e.g. if batadv_forw_packet_list_steal() was called for this
* packet earlier).
*
* Calling batadv_forw_packet_queue() after a call to
* batadv_forw_packet_steal() is forbidden!
*
* Caller needs to ensure that forw_packet->delayed_work was initialized.
*/
static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet,
spinlock_t *lock, struct hlist_head *head,
unsigned long send_time)
{
spin_lock_bh(lock);
/* did purging routine steal it from us? */
if (batadv_forw_packet_was_stolen(forw_packet)) {
/* If you got it for free() without trouble, then
* don't get back into the queue after stealing...
*/
WARN_ONCE(hlist_fake(&forw_packet->cleanup_list),
"Requeuing after batadv_forw_packet_steal() not allowed!\n");
spin_unlock_bh(lock);
return;
}
hlist_del_init(&forw_packet->list);
hlist_add_head(&forw_packet->list, head);
queue_delayed_work(batadv_event_workqueue,
&forw_packet->delayed_work,
send_time - jiffies);
spin_unlock_bh(lock);
}
/**
* batadv_forw_packet_bcast_queue() - try to queue a broadcast packet
* @bat_priv: the bat priv with all the soft interface information
* @forw_packet: the forwarding packet to queue
* @send_time: timestamp (jiffies) when the packet is to be sent
*
* This function tries to (re)queue a broadcast packet.
*
* Caller needs to ensure that forw_packet->delayed_work was initialized.
*/
static void
batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv,
struct batadv_forw_packet *forw_packet,
unsigned long send_time)
{
batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock,
&bat_priv->forw_bcast_list, send_time);
}
/**
* batadv_forw_packet_ogmv1_queue() - try to queue an OGMv1 packet
* @bat_priv: the bat priv with all the soft interface information
* @forw_packet: the forwarding packet to queue
* @send_time: timestamp (jiffies) when the packet is to be sent
*
* This function tries to (re)queue an OGMv1 packet.
*
* Caller needs to ensure that forw_packet->delayed_work was initialized.
*/
void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
struct batadv_forw_packet *forw_packet,
unsigned long send_time)
{
batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock,
&bat_priv->forw_bat_list, send_time);
}
/**
* batadv_add_bcast_packet_to_list() - queue broadcast packet for multiple sends
* @bat_priv: the bat priv with all the soft interface information
* @skb: broadcast packet to add
* @delay: number of jiffies to wait before sending
* @own_packet: true if it is a self-generated broadcast packet
*
* add a broadcast packet to the queue and setup timers. broadcast packets
* are sent multiple times to increase probability for being received.
*
* The skb is not consumed, so the caller should make sure that the
* skb is freed.
*
* Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
*/
int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
const struct sk_buff *skb,
unsigned long delay,
bool own_packet)
{
struct batadv_hard_iface *primary_if;
struct batadv_forw_packet *forw_packet;
struct batadv_bcast_packet *bcast_packet;
struct sk_buff *newskb;
primary_if = batadv_primary_if_get_selected(bat_priv);
if (!primary_if)
goto err;
newskb = skb_copy(skb, GFP_ATOMIC);
if (!newskb) {
batadv_hardif_put(primary_if);
goto err;
}
forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
&bat_priv->bcast_queue_left,
bat_priv, newskb);
batadv_hardif_put(primary_if);
if (!forw_packet)
goto err_packet_free;
/* as we have a copy now, it is safe to decrease the TTL */
bcast_packet = (struct batadv_bcast_packet *)newskb->data;
bcast_packet->ttl--;
forw_packet->own = own_packet;
INIT_DELAYED_WORK(&forw_packet->delayed_work,
batadv_send_outstanding_bcast_packet);
batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
return NETDEV_TX_OK;
err_packet_free:
kfree_skb(newskb);
err:
return NETDEV_TX_BUSY;
}
/**
* batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
* @forw_packet: the forwarding packet to check
* @hard_iface: the interface to check on
*
* Checks whether a given packet has any (re)transmissions left on the provided
* interface.
*
* hard_iface may be NULL: In that case the number of transmissions this skb had
* so far is compared with the maximum amount of retransmissions independent of
* any interface instead.
*
* Return: True if (re)transmissions are left, false otherwise.
*/
static bool
batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet,
struct batadv_hard_iface *hard_iface)
{
unsigned int max;
if (hard_iface)
max = hard_iface->num_bcasts;
else
max = BATADV_NUM_BCASTS_MAX;
return BATADV_SKB_CB(forw_packet->skb)->num_bcasts < max;
}
/**
* batadv_forw_packet_bcasts_inc() - increment retransmission counter of a
* packet
* @forw_packet: the packet to increase the counter for
*/
static void
batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
{
BATADV_SKB_CB(forw_packet->skb)->num_bcasts++;
}
/**
* batadv_forw_packet_is_rebroadcast() - check packet for previous transmissions
* @forw_packet: the packet to check
*
* Return: True if this packet was transmitted before, false otherwise.
*/
bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
{
return BATADV_SKB_CB(forw_packet->skb)->num_bcasts > 0;
}
static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
{
struct batadv_hard_iface *hard_iface;
struct batadv_hardif_neigh_node *neigh_node;
struct delayed_work *delayed_work;
struct batadv_forw_packet *forw_packet;
struct batadv_bcast_packet *bcast_packet;
struct sk_buff *skb1;
struct net_device *soft_iface;
struct batadv_priv *bat_priv;
unsigned long send_time = jiffies + msecs_to_jiffies(5);
bool dropped = false;
u8 *neigh_addr;
u8 *orig_neigh;
int ret = 0;
delayed_work = to_delayed_work(work);
forw_packet = container_of(delayed_work, struct batadv_forw_packet,
delayed_work);
soft_iface = forw_packet->if_incoming->soft_iface;
bat_priv = netdev_priv(soft_iface);
if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
dropped = true;
goto out;
}
if (batadv_dat_drop_broadcast_packet(bat_priv, forw_packet)) {
dropped = true;
goto out;
}
bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
/* rebroadcast packet */
rcu_read_lock();
list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
if (hard_iface->soft_iface != soft_iface)
continue;
if (!batadv_forw_packet_bcasts_left(forw_packet, hard_iface))
continue;
if (forw_packet->own) {
neigh_node = NULL;
} else {
neigh_addr = eth_hdr(forw_packet->skb)->h_source;
neigh_node = batadv_hardif_neigh_get(hard_iface,
neigh_addr);
}
orig_neigh = neigh_node ? neigh_node->orig : NULL;
ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
orig_neigh);
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, "BCAST packet from orig %pM on %s suppressed: %s\n",
bcast_packet->orig,
hard_iface->net_dev->name, type);
if (neigh_node)
batadv_hardif_neigh_put(neigh_node);
continue;
}
if (neigh_node)
batadv_hardif_neigh_put(neigh_node);
if (!kref_get_unless_zero(&hard_iface->refcount))
continue;
/* send a copy of the saved skb */
skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
if (skb1)
batadv_send_broadcast_skb(skb1, hard_iface);
batadv_hardif_put(hard_iface);
}
rcu_read_unlock();
batadv_forw_packet_bcasts_inc(forw_packet);
/* if we still have some more bcasts to send */
if (batadv_forw_packet_bcasts_left(forw_packet, NULL)) {
batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
send_time);
return;
}
out:
/* do we get something for free()? */
if (batadv_forw_packet_steal(forw_packet,
&bat_priv->forw_bcast_list_lock))
batadv_forw_packet_free(forw_packet, dropped);
}
/**
* batadv_purge_outstanding_packets() - stop/purge scheduled bcast/OGMv1 packets
* @bat_priv: the bat priv with all the soft interface information
* @hard_iface: the hard interface to cancel and purge bcast/ogm packets on
*
* This method cancels and purges any broadcast and OGMv1 packet on the given
* hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard
* interfaces will be canceled and purged.
*
* This function might sleep.
*/
void
batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
const struct batadv_hard_iface *hard_iface)
{
struct hlist_head head = HLIST_HEAD_INIT;
if (hard_iface)
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"%s(): %s\n",
__func__, hard_iface->net_dev->name);
else
batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
"%s()\n", __func__);
/* claim bcast list for free() */
spin_lock_bh(&bat_priv->forw_bcast_list_lock);
batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head,
hard_iface);
spin_unlock_bh(&bat_priv->forw_bcast_list_lock);
/* claim batman packet list for free() */
spin_lock_bh(&bat_priv->forw_bat_list_lock);
batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head,
hard_iface);
spin_unlock_bh(&bat_priv->forw_bat_list_lock);
/* then cancel or wait for packet workers to finish and free */
batadv_forw_packet_list_free(&head);
}
|