1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) B.A.T.M.A.N. contributors:
3 *
4 * Antonio Quartulli
5 */
6
7#include "bat_v_ogm.h"
8#include "main.h"
9
10#include <linux/atomic.h>
11#include <linux/byteorder/generic.h>
12#include <linux/container_of.h>
13#include <linux/errno.h>
14#include <linux/etherdevice.h>
15#include <linux/gfp.h>
16#include <linux/if_ether.h>
17#include <linux/jiffies.h>
18#include <linux/kref.h>
19#include <linux/list.h>
20#include <linux/lockdep.h>
21#include <linux/minmax.h>
22#include <linux/mutex.h>
23#include <linux/netdevice.h>
24#include <linux/random.h>
25#include <linux/rcupdate.h>
26#include <linux/skbuff.h>
27#include <linux/slab.h>
28#include <linux/spinlock.h>
29#include <linux/stddef.h>
30#include <linux/string.h>
31#include <linux/types.h>
32#include <linux/workqueue.h>
33#include <uapi/linux/batadv_packet.h>
34
35#include "hard-interface.h"
36#include "hash.h"
37#include "log.h"
38#include "originator.h"
39#include "routing.h"
40#include "send.h"
41#include "translation-table.h"
42#include "tvlv.h"
43
44/**
45 * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
46 * @bat_priv: the bat priv with all the mesh interface information
47 * @addr: the address of the originator
48 *
49 * Return: the orig_node corresponding to the specified address. If such an
50 * object does not exist, it is allocated here. In case of allocation failure
51 * returns NULL.
52 */
53struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
54 const u8 *addr)
55{
56 struct batadv_orig_node *orig_node;
57 int hash_added;
58
59 orig_node = batadv_orig_hash_find(bat_priv, data: addr);
60 if (orig_node)
61 return orig_node;
62
63 orig_node = batadv_orig_node_new(bat_priv, addr);
64 if (!orig_node)
65 return NULL;
66
67 kref_get(kref: &orig_node->refcount);
68 hash_added = batadv_hash_add(hash: bat_priv->orig_hash, compare: batadv_compare_orig,
69 choose: batadv_choose_orig, data: orig_node,
70 data_node: &orig_node->hash_entry);
71 if (hash_added != 0) {
72 /* remove refcnt for newly created orig_node and hash entry */
73 batadv_orig_node_put(orig_node);
74 batadv_orig_node_put(orig_node);
75 orig_node = NULL;
76 }
77
78 return orig_node;
79}
80
81/**
82 * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
83 * @hard_iface: the interface to use to send the OGM
84 */
85static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
86{
87 unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
88
89 /* msecs * [0.9, 1.1] */
90 msecs += get_random_u32_below(ceil: msecs / 5) - (msecs / 10);
91 queue_delayed_work(wq: batadv_event_workqueue, dwork: &hard_iface->bat_v.aggr_wq,
92 delay: msecs_to_jiffies(m: msecs / 1000));
93}
94
95/**
96 * batadv_v_ogm_start_timer() - restart the OGM sending timer
97 * @bat_priv: the bat priv with all the mesh interface information
98 */
99static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
100{
101 unsigned long msecs;
102 /* this function may be invoked in different contexts (ogm rescheduling
103 * or hard_iface activation), but the work timer should not be reset
104 */
105 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
106 return;
107
108 msecs = atomic_read(v: &bat_priv->orig_interval) - BATADV_JITTER;
109 msecs += get_random_u32_below(ceil: 2 * BATADV_JITTER);
110 queue_delayed_work(wq: batadv_event_workqueue, dwork: &bat_priv->bat_v.ogm_wq,
111 delay: msecs_to_jiffies(m: msecs));
112}
113
114/**
115 * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
116 * @skb: the OGM to send
117 * @hard_iface: the interface to use to send the OGM
118 */
119static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
120 struct batadv_hard_iface *hard_iface)
121{
122 struct batadv_priv *bat_priv = netdev_priv(dev: hard_iface->mesh_iface);
123
124 if (hard_iface->if_status != BATADV_IF_ACTIVE) {
125 kfree_skb(skb);
126 return;
127 }
128
129 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
130 batadv_add_counter(bat_priv, idx: BATADV_CNT_MGMT_TX_BYTES,
131 count: skb->len + ETH_HLEN);
132
133 batadv_send_broadcast_skb(skb, hard_iface);
134}
135
136/**
137 * batadv_v_ogm_len() - OGMv2 packet length
138 * @skb: the OGM to check
139 *
140 * Return: Length of the given OGMv2 packet, including tvlv length, excluding
141 * ethernet header length.
142 */
143static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
144{
145 struct batadv_ogm2_packet *ogm_packet;
146
147 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
148 return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
149}
150
151/**
152 * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
153 * @skb: the OGM to check
154 * @hard_iface: the interface to use to send the OGM
155 *
156 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
157 *
158 * Return: True, if the given OGMv2 packet still fits, false otherwise.
159 */
160static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
161 struct batadv_hard_iface *hard_iface)
162{
163 unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
164 BATADV_MAX_AGGREGATION_BYTES);
165 unsigned int ogm_len = batadv_v_ogm_len(skb);
166
167 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
168
169 return hard_iface->bat_v.aggr_len + ogm_len <= max;
170}
171
172/**
173 * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
174 * @hard_iface: the interface holding the aggregation queue
175 *
176 * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
177 *
178 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
179 */
180static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
181{
182 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
183
184 __skb_queue_purge(list: &hard_iface->bat_v.aggr_list);
185 hard_iface->bat_v.aggr_len = 0;
186}
187
188/**
189 * batadv_v_ogm_aggr_send() - flush & send aggregation queue
190 * @hard_iface: the interface with the aggregation queue to flush
191 *
192 * Aggregates all OGMv2 packets currently in the aggregation queue into a
193 * single OGMv2 packet and transmits this aggregate.
194 *
195 * The aggregation queue is empty after this call.
196 *
197 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
198 */
199static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
200{
201 unsigned int aggr_len = hard_iface->bat_v.aggr_len;
202 struct sk_buff *skb_aggr;
203 unsigned int ogm_len;
204 struct sk_buff *skb;
205
206 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
207
208 if (!aggr_len)
209 return;
210
211 skb_aggr = dev_alloc_skb(length: aggr_len + ETH_HLEN + NET_IP_ALIGN);
212 if (!skb_aggr) {
213 batadv_v_ogm_aggr_list_free(hard_iface);
214 return;
215 }
216
217 skb_reserve(skb: skb_aggr, ETH_HLEN + NET_IP_ALIGN);
218 skb_reset_network_header(skb: skb_aggr);
219
220 while ((skb = __skb_dequeue(list: &hard_iface->bat_v.aggr_list))) {
221 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
222
223 ogm_len = batadv_v_ogm_len(skb);
224 skb_put_data(skb: skb_aggr, data: skb->data, len: ogm_len);
225
226 consume_skb(skb);
227 }
228
229 batadv_v_ogm_send_to_if(skb: skb_aggr, hard_iface);
230}
231
232/**
233 * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
234 * @skb: the OGM to queue
235 * @hard_iface: the interface to queue the OGM on
236 */
237static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
238 struct batadv_hard_iface *hard_iface)
239{
240 struct batadv_priv *bat_priv = netdev_priv(dev: hard_iface->mesh_iface);
241
242 if (!atomic_read(v: &bat_priv->aggregated_ogms)) {
243 batadv_v_ogm_send_to_if(skb, hard_iface);
244 return;
245 }
246
247 spin_lock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
248 if (!batadv_v_ogm_queue_left(skb, hard_iface))
249 batadv_v_ogm_aggr_send(hard_iface);
250
251 hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
252 __skb_queue_tail(list: &hard_iface->bat_v.aggr_list, newsk: skb);
253 spin_unlock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
254}
255
256/**
257 * batadv_v_ogm_send_meshif() - periodic worker broadcasting the own OGM
258 * @bat_priv: the bat priv with all the mesh interface information
259 */
260static void batadv_v_ogm_send_meshif(struct batadv_priv *bat_priv)
261{
262 struct batadv_hard_iface *hard_iface;
263 struct batadv_ogm2_packet *ogm_packet;
264 struct sk_buff *skb, *skb_tmp;
265 unsigned char *ogm_buff;
266 struct list_head *iter;
267 int ogm_buff_len;
268 u16 tvlv_len = 0;
269 int ret;
270
271 lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
272
273 if (atomic_read(v: &bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
274 goto out;
275
276 ogm_buff = bat_priv->bat_v.ogm_buff;
277 ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
278 /* tt changes have to be committed before the tvlv data is
279 * appended as it may alter the tt tvlv container
280 */
281 batadv_tt_local_commit_changes(bat_priv);
282 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, packet_buff: &ogm_buff,
283 packet_buff_len: &ogm_buff_len,
284 BATADV_OGM2_HLEN);
285
286 bat_priv->bat_v.ogm_buff = ogm_buff;
287 bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
288
289 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
290 if (!skb)
291 goto reschedule;
292
293 skb_reserve(skb, ETH_HLEN);
294 skb_put_data(skb, data: ogm_buff, len: ogm_buff_len);
295
296 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
297 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
298 atomic_inc(v: &bat_priv->bat_v.ogm_seqno);
299 ogm_packet->tvlv_len = htons(tvlv_len);
300
301 /* broadcast on every interface */
302 rcu_read_lock();
303 netdev_for_each_lower_private_rcu(bat_priv->mesh_iface, hard_iface, iter) {
304 if (!kref_get_unless_zero(kref: &hard_iface->refcount))
305 continue;
306
307 ret = batadv_hardif_no_broadcast(if_outgoing: hard_iface, NULL, NULL);
308 if (ret) {
309 char *type;
310
311 switch (ret) {
312 case BATADV_HARDIF_BCAST_NORECIPIENT:
313 type = "no neighbor";
314 break;
315 case BATADV_HARDIF_BCAST_DUPFWD:
316 type = "single neighbor is source";
317 break;
318 case BATADV_HARDIF_BCAST_DUPORIG:
319 type = "single neighbor is originator";
320 break;
321 default:
322 type = "unknown";
323 }
324
325 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
326 hard_iface->net_dev->name, type);
327
328 batadv_hardif_put(hard_iface);
329 continue;
330 }
331
332 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
333 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
334 ogm_packet->orig, ntohl(ogm_packet->seqno),
335 ntohl(ogm_packet->throughput), ogm_packet->ttl,
336 hard_iface->net_dev->name,
337 hard_iface->net_dev->dev_addr);
338
339 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
340 skb_tmp = skb_clone(skb, GFP_ATOMIC);
341 if (!skb_tmp) {
342 batadv_hardif_put(hard_iface);
343 break;
344 }
345
346 batadv_v_ogm_queue_on_if(skb: skb_tmp, hard_iface);
347 batadv_hardif_put(hard_iface);
348 }
349 rcu_read_unlock();
350
351 consume_skb(skb);
352
353reschedule:
354 batadv_v_ogm_start_timer(bat_priv);
355out:
356 return;
357}
358
359/**
360 * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
361 * @work: work queue item
362 */
363static void batadv_v_ogm_send(struct work_struct *work)
364{
365 struct batadv_priv_bat_v *bat_v;
366 struct batadv_priv *bat_priv;
367
368 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
369 bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
370
371 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
372 batadv_v_ogm_send_meshif(bat_priv);
373 mutex_unlock(lock: &bat_priv->bat_v.ogm_buff_mutex);
374}
375
376/**
377 * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
378 * @work: work queue item
379 *
380 * Emits aggregated OGM messages in regular intervals.
381 */
382void batadv_v_ogm_aggr_work(struct work_struct *work)
383{
384 struct batadv_hard_iface_bat_v *batv;
385 struct batadv_hard_iface *hard_iface;
386
387 batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
388 hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
389
390 spin_lock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
391 batadv_v_ogm_aggr_send(hard_iface);
392 spin_unlock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
393
394 batadv_v_ogm_start_queue_timer(hard_iface);
395}
396
397/**
398 * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
399 * @hard_iface: the interface to prepare
400 *
401 * Takes care of scheduling its own OGM sending routine for this interface.
402 *
403 * Return: 0 on success or a negative error code otherwise
404 */
405int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
406{
407 struct batadv_priv *bat_priv = netdev_priv(dev: hard_iface->mesh_iface);
408
409 batadv_v_ogm_start_queue_timer(hard_iface);
410 batadv_v_ogm_start_timer(bat_priv);
411
412 return 0;
413}
414
415/**
416 * batadv_v_ogm_iface_disable() - release OGM interface private resources
417 * @hard_iface: interface for which the resources have to be released
418 */
419void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
420{
421 cancel_delayed_work_sync(dwork: &hard_iface->bat_v.aggr_wq);
422
423 spin_lock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
424 batadv_v_ogm_aggr_list_free(hard_iface);
425 spin_unlock_bh(lock: &hard_iface->bat_v.aggr_list.lock);
426}
427
428/**
429 * batadv_v_ogm_primary_iface_set() - set a new primary interface
430 * @primary_iface: the new primary interface
431 */
432void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
433{
434 struct batadv_priv *bat_priv = netdev_priv(dev: primary_iface->mesh_iface);
435 struct batadv_ogm2_packet *ogm_packet;
436
437 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
438 if (!bat_priv->bat_v.ogm_buff)
439 goto unlock;
440
441 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
442 ether_addr_copy(dst: ogm_packet->orig, src: primary_iface->net_dev->dev_addr);
443
444unlock:
445 mutex_unlock(lock: &bat_priv->bat_v.ogm_buff_mutex);
446}
447
448/**
449 * batadv_v_forward_penalty() - apply a penalty to the throughput metric
450 * forwarded with B.A.T.M.A.N. V OGMs
451 * @bat_priv: the bat priv with all the mesh interface information
452 * @if_incoming: the interface where the OGM has been received
453 * @if_outgoing: the interface where the OGM has to be forwarded to
454 * @throughput: the current throughput
455 *
456 * Apply a penalty on the current throughput metric value based on the
457 * characteristic of the interface where the OGM has been received.
458 *
459 * Initially the per hardif hop penalty is applied to the throughput. After
460 * that the return value is then computed as follows:
461 * - throughput * 50% if the incoming and outgoing interface are the
462 * same WiFi interface and the throughput is above
463 * 1MBit/s
464 * - throughput if the outgoing interface is the default
465 * interface (i.e. this OGM is processed for the
466 * internal table and not forwarded)
467 * - throughput * node hop penalty otherwise
468 *
469 * Return: the penalised throughput metric.
470 */
471static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
472 struct batadv_hard_iface *if_incoming,
473 struct batadv_hard_iface *if_outgoing,
474 u32 throughput)
475{
476 int if_hop_penalty = atomic_read(v: &if_incoming->hop_penalty);
477 int hop_penalty = atomic_read(v: &bat_priv->hop_penalty);
478 int hop_penalty_max = BATADV_TQ_MAX_VALUE;
479
480 /* Apply per hardif hop penalty */
481 throughput = throughput * (hop_penalty_max - if_hop_penalty) /
482 hop_penalty_max;
483
484 /* Don't apply hop penalty in default originator table. */
485 if (if_outgoing == BATADV_IF_DEFAULT)
486 return throughput;
487
488 /* Forwarding on the same WiFi interface cuts the throughput in half
489 * due to the store & forward characteristics of WIFI.
490 * Very low throughput values are the exception.
491 */
492 if (throughput > 10 &&
493 if_incoming == if_outgoing &&
494 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
495 return throughput / 2;
496
497 /* hop penalty of 255 equals 100% */
498 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
499}
500
501/**
502 * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
503 * outgoing interface
504 * @bat_priv: the bat priv with all the mesh interface information
505 * @ogm_received: previously received OGM to be forwarded
506 * @orig_node: the originator which has been updated
507 * @neigh_node: the neigh_node through with the OGM has been received
508 * @if_incoming: the interface on which this OGM was received on
509 * @if_outgoing: the interface to which the OGM has to be forwarded to
510 *
511 * Forward an OGM to an interface after having altered the throughput metric and
512 * the TTL value contained in it. The original OGM isn't modified.
513 */
514static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
515 const struct batadv_ogm2_packet *ogm_received,
516 struct batadv_orig_node *orig_node,
517 struct batadv_neigh_node *neigh_node,
518 struct batadv_hard_iface *if_incoming,
519 struct batadv_hard_iface *if_outgoing)
520{
521 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
522 struct batadv_orig_ifinfo *orig_ifinfo = NULL;
523 struct batadv_neigh_node *router = NULL;
524 struct batadv_ogm2_packet *ogm_forward;
525 unsigned char *skb_buff;
526 struct sk_buff *skb;
527 size_t packet_len;
528 u16 tvlv_len;
529
530 /* only forward for specific interfaces, not for the default one. */
531 if (if_outgoing == BATADV_IF_DEFAULT)
532 goto out;
533
534 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
535 if (!orig_ifinfo)
536 goto out;
537
538 /* acquire possibly updated router */
539 router = batadv_orig_router_get(orig_node, if_outgoing);
540
541 /* strict rule: forward packets coming from the best next hop only */
542 if (neigh_node != router)
543 goto out;
544
545 /* don't forward the same seqno twice on one interface */
546 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
547 goto out;
548
549 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
550
551 if (ogm_received->ttl <= 1) {
552 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
553 goto out;
554 }
555
556 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh: neigh_node, if_outgoing);
557 if (!neigh_ifinfo)
558 goto out;
559
560 tvlv_len = ntohs(ogm_received->tvlv_len);
561
562 packet_len = BATADV_OGM2_HLEN + tvlv_len;
563 skb = netdev_alloc_skb_ip_align(dev: if_outgoing->net_dev,
564 ETH_HLEN + packet_len);
565 if (!skb)
566 goto out;
567
568 skb_reserve(skb, ETH_HLEN);
569 skb_buff = skb_put_data(skb, data: ogm_received, len: packet_len);
570
571 /* apply forward penalty */
572 ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
573 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
574 ogm_forward->ttl--;
575
576 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
577 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
578 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
579 ogm_forward->ttl, if_incoming->net_dev->name);
580
581 batadv_v_ogm_queue_on_if(skb, hard_iface: if_outgoing);
582
583out:
584 batadv_orig_ifinfo_put(orig_ifinfo);
585 batadv_neigh_node_put(neigh_node: router);
586 batadv_neigh_ifinfo_put(neigh_ifinfo);
587}
588
589/**
590 * batadv_v_ogm_metric_update() - update route metric based on OGM
591 * @bat_priv: the bat priv with all the mesh interface information
592 * @ogm2: OGM2 structure
593 * @orig_node: Originator structure for which the OGM has been received
594 * @neigh_node: the neigh_node through with the OGM has been received
595 * @if_incoming: the interface where this packet was received
596 * @if_outgoing: the interface for which the packet should be considered
597 *
598 * Return:
599 * 1 if the OGM is new,
600 * 0 if it is not new but valid,
601 * <0 on error (e.g. old OGM)
602 */
603static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
604 const struct batadv_ogm2_packet *ogm2,
605 struct batadv_orig_node *orig_node,
606 struct batadv_neigh_node *neigh_node,
607 struct batadv_hard_iface *if_incoming,
608 struct batadv_hard_iface *if_outgoing)
609{
610 struct batadv_orig_ifinfo *orig_ifinfo;
611 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
612 bool protection_started = false;
613 int ret = -EINVAL;
614 u32 path_throughput;
615 s32 seq_diff;
616
617 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
618 if (!orig_ifinfo)
619 goto out;
620
621 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
622
623 if (!hlist_empty(h: &orig_node->neigh_list) &&
624 batadv_window_protected(bat_priv, seq_num_diff: seq_diff,
625 BATADV_OGM_MAX_AGE,
626 last_reset: &orig_ifinfo->batman_seqno_reset,
627 protection_started: &protection_started)) {
628 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
629 "Drop packet: packet within window protection time from %pM\n",
630 ogm2->orig);
631 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
632 "Last reset: %ld, %ld\n",
633 orig_ifinfo->batman_seqno_reset, jiffies);
634 goto out;
635 }
636
637 /* drop packets with old seqnos, however accept the first packet after
638 * a host has been rebooted.
639 */
640 if (seq_diff < 0 && !protection_started)
641 goto out;
642
643 neigh_node->last_seen = jiffies;
644
645 orig_node->last_seen = jiffies;
646
647 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
648 orig_ifinfo->last_ttl = ogm2->ttl;
649
650 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh: neigh_node, if_outgoing);
651 if (!neigh_ifinfo)
652 goto out;
653
654 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
655 if_outgoing,
656 ntohl(ogm2->throughput));
657 neigh_ifinfo->bat_v.throughput = path_throughput;
658 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
659 neigh_ifinfo->last_ttl = ogm2->ttl;
660
661 if (seq_diff > 0 || protection_started)
662 ret = 1;
663 else
664 ret = 0;
665out:
666 batadv_orig_ifinfo_put(orig_ifinfo);
667 batadv_neigh_ifinfo_put(neigh_ifinfo);
668
669 return ret;
670}
671
672/**
673 * batadv_v_ogm_route_update() - update routes based on OGM
674 * @bat_priv: the bat priv with all the mesh interface information
675 * @ethhdr: the Ethernet header of the OGM2
676 * @ogm2: OGM2 structure
677 * @orig_node: Originator structure for which the OGM has been received
678 * @neigh_node: the neigh_node through with the OGM has been received
679 * @if_incoming: the interface where this packet was received
680 * @if_outgoing: the interface for which the packet should be considered
681 *
682 * Return: true if the packet should be forwarded, false otherwise
683 */
684static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
685 const struct ethhdr *ethhdr,
686 const struct batadv_ogm2_packet *ogm2,
687 struct batadv_orig_node *orig_node,
688 struct batadv_neigh_node *neigh_node,
689 struct batadv_hard_iface *if_incoming,
690 struct batadv_hard_iface *if_outgoing)
691{
692 struct batadv_neigh_node *router = NULL;
693 struct batadv_orig_node *orig_neigh_node;
694 struct batadv_neigh_node *orig_neigh_router = NULL;
695 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
696 u32 router_throughput, neigh_throughput;
697 u32 router_last_seqno;
698 u32 neigh_last_seqno;
699 s32 neigh_seq_diff;
700 bool forward = false;
701
702 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, addr: ethhdr->h_source);
703 if (!orig_neigh_node)
704 goto out;
705
706 orig_neigh_router = batadv_orig_router_get(orig_node: orig_neigh_node,
707 if_outgoing);
708
709 /* drop packet if sender is not a direct neighbor and if we
710 * don't route towards it
711 */
712 router = batadv_orig_router_get(orig_node, if_outgoing);
713 if (router && router->orig_node != orig_node && !orig_neigh_router) {
714 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
715 "Drop packet: OGM via unknown neighbor!\n");
716 goto out;
717 }
718
719 /* Mark the OGM to be considered for forwarding, and update routes
720 * if needed.
721 */
722 forward = true;
723
724 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
725 "Searching and updating originator entry of received packet\n");
726
727 /* if this neighbor already is our next hop there is nothing
728 * to change
729 */
730 if (router == neigh_node)
731 goto out;
732
733 /* don't consider neighbours with worse throughput.
734 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
735 * the last received seqno from our best next hop.
736 */
737 if (router) {
738 router_ifinfo = batadv_neigh_ifinfo_get(neigh: router, if_outgoing);
739 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh: neigh_node, if_outgoing);
740
741 /* if these are not allocated, something is wrong. */
742 if (!router_ifinfo || !neigh_ifinfo)
743 goto out;
744
745 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
746 router_last_seqno = router_ifinfo->bat_v.last_seqno;
747 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
748 router_throughput = router_ifinfo->bat_v.throughput;
749 neigh_throughput = neigh_ifinfo->bat_v.throughput;
750
751 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
752 router_throughput >= neigh_throughput)
753 goto out;
754 }
755
756 batadv_update_route(bat_priv, orig_node, recv_if: if_outgoing, neigh_node);
757out:
758 batadv_neigh_node_put(neigh_node: router);
759 batadv_neigh_node_put(neigh_node: orig_neigh_router);
760 batadv_orig_node_put(orig_node: orig_neigh_node);
761 batadv_neigh_ifinfo_put(neigh_ifinfo: router_ifinfo);
762 batadv_neigh_ifinfo_put(neigh_ifinfo);
763
764 return forward;
765}
766
767/**
768 * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
769 * @bat_priv: the bat priv with all the mesh interface information
770 * @ethhdr: the Ethernet header of the OGM2
771 * @ogm2: OGM2 structure
772 * @orig_node: Originator structure for which the OGM has been received
773 * @neigh_node: the neigh_node through with the OGM has been received
774 * @if_incoming: the interface where this packet was received
775 * @if_outgoing: the interface for which the packet should be considered
776 */
777static void
778batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
779 const struct ethhdr *ethhdr,
780 const struct batadv_ogm2_packet *ogm2,
781 struct batadv_orig_node *orig_node,
782 struct batadv_neigh_node *neigh_node,
783 struct batadv_hard_iface *if_incoming,
784 struct batadv_hard_iface *if_outgoing)
785{
786 int seqno_age;
787 bool forward;
788
789 /* first, update the metric with according sanity checks */
790 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
791 neigh_node, if_incoming,
792 if_outgoing);
793
794 /* outdated sequence numbers are to be discarded */
795 if (seqno_age < 0)
796 return;
797
798 /* only unknown & newer OGMs contain TVLVs we are interested in */
799 if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
800 batadv_tvlv_containers_process(bat_priv, packet_type: BATADV_OGM2, orig_node,
801 NULL,
802 tvlv_buff: (unsigned char *)(ogm2 + 1),
803 ntohs(ogm2->tvlv_len));
804
805 /* if the metric update went through, update routes if needed */
806 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
807 neigh_node, if_incoming,
808 if_outgoing);
809
810 /* if the routes have been processed correctly, check and forward */
811 if (forward)
812 batadv_v_ogm_forward(bat_priv, ogm_received: ogm2, orig_node, neigh_node,
813 if_incoming, if_outgoing);
814}
815
816/**
817 * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
818 * @buff_pos: current position in the skb
819 * @packet_len: total length of the skb
820 * @ogm2_packet: potential OGM2 in buffer
821 *
822 * Return: true if there is enough space for another OGM, false otherwise.
823 */
824static bool
825batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
826 const struct batadv_ogm2_packet *ogm2_packet)
827{
828 int next_buff_pos = 0;
829
830 /* check if there is enough space for the header */
831 next_buff_pos += buff_pos + sizeof(*ogm2_packet);
832 if (next_buff_pos > packet_len)
833 return false;
834
835 /* check if there is enough space for the optional TVLV */
836 next_buff_pos += ntohs(ogm2_packet->tvlv_len);
837
838 return next_buff_pos <= packet_len;
839}
840
841/**
842 * batadv_v_ogm_process() - process an incoming batman v OGM
843 * @skb: the skb containing the OGM
844 * @ogm_offset: offset to the OGM which should be processed (for aggregates)
845 * @if_incoming: the interface where this packet was received
846 */
847static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
848 struct batadv_hard_iface *if_incoming)
849{
850 struct batadv_priv *bat_priv = netdev_priv(dev: if_incoming->mesh_iface);
851 struct ethhdr *ethhdr;
852 struct batadv_orig_node *orig_node = NULL;
853 struct batadv_hardif_neigh_node *hardif_neigh = NULL;
854 struct batadv_neigh_node *neigh_node = NULL;
855 struct batadv_hard_iface *hard_iface;
856 struct batadv_ogm2_packet *ogm_packet;
857 u32 ogm_throughput, link_throughput, path_throughput;
858 struct list_head *iter;
859 int ret;
860
861 ethhdr = eth_hdr(skb);
862 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
863
864 ogm_throughput = ntohl(ogm_packet->throughput);
865
866 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
867 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
868 ethhdr->h_source, if_incoming->net_dev->name,
869 if_incoming->net_dev->dev_addr, ogm_packet->orig,
870 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
871 ogm_packet->version, ntohs(ogm_packet->tvlv_len));
872
873 if (batadv_is_my_mac(bat_priv, addr: ogm_packet->orig)) {
874 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
875 "Drop packet: originator packet from ourself\n");
876 return;
877 }
878
879 /* If the throughput metric is 0, immediately drop the packet. No need
880 * to create orig_node / neigh_node for an unusable route.
881 */
882 if (ogm_throughput == 0) {
883 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
884 "Drop packet: originator packet with throughput metric of 0\n");
885 return;
886 }
887
888 /* require ELP packets be to received from this neighbor first */
889 hardif_neigh = batadv_hardif_neigh_get(hard_iface: if_incoming, neigh_addr: ethhdr->h_source);
890 if (!hardif_neigh) {
891 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
892 "Drop packet: OGM via unknown neighbor!\n");
893 goto out;
894 }
895
896 orig_node = batadv_v_ogm_orig_get(bat_priv, addr: ogm_packet->orig);
897 if (!orig_node)
898 goto out;
899
900 neigh_node = batadv_neigh_node_get_or_create(orig_node, hard_iface: if_incoming,
901 neigh_addr: ethhdr->h_source);
902 if (!neigh_node)
903 goto out;
904
905 /* Update the received throughput metric to match the link
906 * characteristic:
907 * - If this OGM traveled one hop so far (emitted by single hop
908 * neighbor) the path throughput metric equals the link throughput.
909 * - For OGMs traversing more than hop the path throughput metric is
910 * the smaller of the path throughput and the link throughput.
911 */
912 link_throughput = ewma_throughput_read(e: &hardif_neigh->bat_v.throughput);
913 path_throughput = min_t(u32, link_throughput, ogm_throughput);
914 ogm_packet->throughput = htonl(path_throughput);
915
916 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm2: ogm_packet, orig_node,
917 neigh_node, if_incoming,
918 BATADV_IF_DEFAULT);
919
920 rcu_read_lock();
921 netdev_for_each_lower_private_rcu(bat_priv->mesh_iface, hard_iface, iter) {
922 if (hard_iface->if_status != BATADV_IF_ACTIVE)
923 continue;
924
925 if (!kref_get_unless_zero(kref: &hard_iface->refcount))
926 continue;
927
928 ret = batadv_hardif_no_broadcast(if_outgoing: hard_iface,
929 orig_addr: ogm_packet->orig,
930 orig_neigh: hardif_neigh->orig);
931
932 if (ret) {
933 char *type;
934
935 switch (ret) {
936 case BATADV_HARDIF_BCAST_NORECIPIENT:
937 type = "no neighbor";
938 break;
939 case BATADV_HARDIF_BCAST_DUPFWD:
940 type = "single neighbor is source";
941 break;
942 case BATADV_HARDIF_BCAST_DUPORIG:
943 type = "single neighbor is originator";
944 break;
945 default:
946 type = "unknown";
947 }
948
949 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
950 ogm_packet->orig, hard_iface->net_dev->name,
951 type);
952
953 batadv_hardif_put(hard_iface);
954 continue;
955 }
956
957 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm2: ogm_packet,
958 orig_node, neigh_node,
959 if_incoming, if_outgoing: hard_iface);
960
961 batadv_hardif_put(hard_iface);
962 }
963 rcu_read_unlock();
964out:
965 batadv_orig_node_put(orig_node);
966 batadv_neigh_node_put(neigh_node);
967 batadv_hardif_neigh_put(hardif_neigh);
968}
969
970/**
971 * batadv_v_ogm_packet_recv() - OGM2 receiving handler
972 * @skb: the received OGM
973 * @if_incoming: the interface where this OGM has been received
974 *
975 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
976 * (without freeing the skb) on failure
977 */
978int batadv_v_ogm_packet_recv(struct sk_buff *skb,
979 struct batadv_hard_iface *if_incoming)
980{
981 struct batadv_priv *bat_priv = netdev_priv(dev: if_incoming->mesh_iface);
982 struct batadv_ogm2_packet *ogm_packet;
983 struct ethhdr *ethhdr;
984 int ogm_offset;
985 u8 *packet_pos;
986 int ret = NET_RX_DROP;
987
988 /* did we receive a OGM2 packet on an interface that does not have
989 * B.A.T.M.A.N. V enabled ?
990 */
991 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
992 goto free_skb;
993
994 if (!batadv_check_management_packet(skb, hard_iface: if_incoming, BATADV_OGM2_HLEN))
995 goto free_skb;
996
997 ethhdr = eth_hdr(skb);
998 if (batadv_is_my_mac(bat_priv, addr: ethhdr->h_source))
999 goto free_skb;
1000
1001 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1002 batadv_add_counter(bat_priv, idx: BATADV_CNT_MGMT_RX_BYTES,
1003 count: skb->len + ETH_HLEN);
1004
1005 ogm_offset = 0;
1006 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1007
1008 while (batadv_v_ogm_aggr_packet(buff_pos: ogm_offset, packet_len: skb_headlen(skb),
1009 ogm2_packet: ogm_packet)) {
1010 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1011
1012 ogm_offset += BATADV_OGM2_HLEN;
1013 ogm_offset += ntohs(ogm_packet->tvlv_len);
1014
1015 packet_pos = skb->data + ogm_offset;
1016 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1017 }
1018
1019 ret = NET_RX_SUCCESS;
1020
1021free_skb:
1022 if (ret == NET_RX_SUCCESS)
1023 consume_skb(skb);
1024 else
1025 kfree_skb(skb);
1026
1027 return ret;
1028}
1029
1030/**
1031 * batadv_v_ogm_init() - initialise the OGM2 engine
1032 * @bat_priv: the bat priv with all the mesh interface information
1033 *
1034 * Return: 0 on success or a negative error code in case of failure
1035 */
1036int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1037{
1038 struct batadv_ogm2_packet *ogm_packet;
1039 unsigned char *ogm_buff;
1040 u32 random_seqno;
1041
1042 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1043 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1044 if (!ogm_buff)
1045 return -ENOMEM;
1046
1047 bat_priv->bat_v.ogm_buff = ogm_buff;
1048 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1049 ogm_packet->packet_type = BATADV_OGM2;
1050 ogm_packet->version = BATADV_COMPAT_VERSION;
1051 ogm_packet->ttl = BATADV_TTL;
1052 ogm_packet->flags = BATADV_NO_FLAGS;
1053 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1054
1055 /* randomize initial seqno to avoid collision */
1056 get_random_bytes(buf: &random_seqno, len: sizeof(random_seqno));
1057 atomic_set(v: &bat_priv->bat_v.ogm_seqno, i: random_seqno);
1058 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1059
1060 mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1061
1062 return 0;
1063}
1064
1065/**
1066 * batadv_v_ogm_free() - free OGM private resources
1067 * @bat_priv: the bat priv with all the mesh interface information
1068 */
1069void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1070{
1071 cancel_delayed_work_sync(dwork: &bat_priv->bat_v.ogm_wq);
1072
1073 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1074
1075 kfree(objp: bat_priv->bat_v.ogm_buff);
1076 bat_priv->bat_v.ogm_buff = NULL;
1077 bat_priv->bat_v.ogm_buff_len = 0;
1078
1079 mutex_unlock(lock: &bat_priv->bat_v.ogm_buff_mutex);
1080}
1081

source code of linux/net/batman-adv/bat_v_ogm.c