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/rculist.h>
26 #include <linux/rcupdate.h>
27 #include <linux/skbuff.h>
28 #include <linux/slab.h>
29 #include <linux/spinlock.h>
30 #include <linux/stddef.h>
31 #include <linux/string.h>
32 #include <linux/types.h>
33 #include <linux/workqueue.h>
34 #include <uapi/linux/batadv_packet.h>
35
36 #include "bat_algo.h"
37 #include "hard-interface.h"
38 #include "hash.h"
39 #include "log.h"
40 #include "originator.h"
41 #include "routing.h"
42 #include "send.h"
43 #include "translation-table.h"
44 #include "tvlv.h"
45
46 /**
47 * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
48 * @bat_priv: the bat priv with all the soft interface information
49 * @addr: the address of the originator
50 *
51 * Return: the orig_node corresponding to the specified address. If such an
52 * object does not exist, it is allocated here. In case of allocation failure
53 * returns NULL.
54 */
55 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
56 const u8 *addr)
57 {
58 struct batadv_orig_node *orig_node;
59 int hash_added;
60
61 orig_node = batadv_orig_hash_find(bat_priv, addr);
62 if (orig_node)
63 return orig_node;
64
65 orig_node = batadv_orig_node_new(bat_priv, addr);
66 if (!orig_node)
67 return NULL;
68
69 kref_get(&orig_node->refcount);
70 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
71 batadv_choose_orig, orig_node,
72 &orig_node->hash_entry);
73 if (hash_added != 0) {
74 /* remove refcnt for newly created orig_node and hash entry */
75 batadv_orig_node_put(orig_node);
76 batadv_orig_node_put(orig_node);
77 orig_node = NULL;
78 }
79
80 return orig_node;
81 }
82
83 /**
84 * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
85 * @hard_iface: the interface to use to send the OGM
86 */
87 static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
88 {
89 unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
90
91 /* msecs * [0.9, 1.1] */
92 msecs += get_random_u32_below(msecs / 5) - (msecs / 10);
93 queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
94 msecs_to_jiffies(msecs / 1000));
95 }
96
97 /**
98 * batadv_v_ogm_start_timer() - restart the OGM sending timer
99 * @bat_priv: the bat priv with all the soft interface information
100 */
101 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
102 {
103 unsigned long msecs;
104 /* this function may be invoked in different contexts (ogm rescheduling
105 * or hard_iface activation), but the work timer should not be reset
106 */
107 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
108 return;
109
110 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
111 msecs += get_random_u32_below(2 * BATADV_JITTER);
112 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
113 msecs_to_jiffies(msecs));
114 }
115
116 /**
117 * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
118 * @skb: the OGM to send
119 * @hard_iface: the interface to use to send the OGM
120 */
121 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
122 struct batadv_hard_iface *hard_iface)
123 {
124 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
125
126 if (hard_iface->if_status != BATADV_IF_ACTIVE) {
127 kfree_skb(skb);
128 return;
129 }
130
131 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
132 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
133 skb->len + ETH_HLEN);
134
135 batadv_send_broadcast_skb(skb, hard_iface);
136 }
137
138 /**
139 * batadv_v_ogm_len() - OGMv2 packet length
140 * @skb: the OGM to check
141 *
142 * Return: Length of the given OGMv2 packet, including tvlv length, excluding
143 * ethernet header length.
144 */
145 static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
146 {
147 struct batadv_ogm2_packet *ogm_packet;
148
149 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
150 return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
151 }
152
153 /**
154 * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
155 * @skb: the OGM to check
156 * @hard_iface: the interface to use to send the OGM
157 *
158 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
159 *
160 * Return: True, if the given OGMv2 packet still fits, false otherwise.
161 */
162 static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
163 struct batadv_hard_iface *hard_iface)
164 {
165 unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
166 BATADV_MAX_AGGREGATION_BYTES);
167 unsigned int ogm_len = batadv_v_ogm_len(skb);
168
169 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
170
171 return hard_iface->bat_v.aggr_len + ogm_len <= max;
172 }
173
174 /**
175 * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
176 * @hard_iface: the interface holding the aggregation queue
177 *
178 * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
179 *
180 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
181 */
182 static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
183 {
184 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
185
186 __skb_queue_purge(&hard_iface->bat_v.aggr_list);
187 hard_iface->bat_v.aggr_len = 0;
188 }
189
190 /**
191 * batadv_v_ogm_aggr_send() - flush & send aggregation queue
192 * @hard_iface: the interface with the aggregation queue to flush
193 *
194 * Aggregates all OGMv2 packets currently in the aggregation queue into a
195 * single OGMv2 packet and transmits this aggregate.
196 *
197 * The aggregation queue is empty after this call.
198 *
199 * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
200 */
201 static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
202 {
203 unsigned int aggr_len = hard_iface->bat_v.aggr_len;
204 struct sk_buff *skb_aggr;
205 unsigned int ogm_len;
206 struct sk_buff *skb;
207
208 lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
209
210 if (!aggr_len)
211 return;
212
213 skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
214 if (!skb_aggr) {
215 batadv_v_ogm_aggr_list_free(hard_iface);
216 return;
217 }
218
219 skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
220 skb_reset_network_header(skb_aggr);
221
222 while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
223 hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
224
225 ogm_len = batadv_v_ogm_len(skb);
226 skb_put_data(skb_aggr, skb->data, ogm_len);
227
228 consume_skb(skb);
229 }
230
231 batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
232 }
233
234 /**
235 * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
236 * @skb: the OGM to queue
237 * @hard_iface: the interface to queue the OGM on
238 */
239 static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
240 struct batadv_hard_iface *hard_iface)
241 {
242 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
243
244 if (!atomic_read(&bat_priv->aggregated_ogms)) {
245 batadv_v_ogm_send_to_if(skb, hard_iface);
246 return;
247 }
248
249 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
250 if (!batadv_v_ogm_queue_left(skb, hard_iface))
251 batadv_v_ogm_aggr_send(hard_iface);
252
253 hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
254 __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
255 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
256 }
257
258 /**
259 * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
260 * @bat_priv: the bat priv with all the soft interface information
261 */
262 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
263 {
264 struct batadv_hard_iface *hard_iface;
265 struct batadv_ogm2_packet *ogm_packet;
266 struct sk_buff *skb, *skb_tmp;
267 unsigned char *ogm_buff;
268 int ogm_buff_len;
269 u16 tvlv_len = 0;
270 int ret;
271
272 lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
273
274 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
275 goto out;
276
277 ogm_buff = bat_priv->bat_v.ogm_buff;
278 ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
279 /* tt changes have to be committed before the tvlv data is
280 * appended as it may alter the tt tvlv container
281 */
282 batadv_tt_local_commit_changes(bat_priv);
283 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
284 &ogm_buff_len,
285 BATADV_OGM2_HLEN);
286
287 bat_priv->bat_v.ogm_buff = ogm_buff;
288 bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
289
290 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
291 if (!skb)
292 goto reschedule;
293
294 skb_reserve(skb, ETH_HLEN);
295 skb_put_data(skb, ogm_buff, ogm_buff_len);
296
297 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
298 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
299 atomic_inc(&bat_priv->bat_v.ogm_seqno);
300 ogm_packet->tvlv_len = htons(tvlv_len);
301
302 /* broadcast on every interface */
303 rcu_read_lock();
304 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
305 if (hard_iface->soft_iface != bat_priv->soft_iface)
306 continue;
307
308 if (!kref_get_unless_zero(&hard_iface->refcount))
309 continue;
310
311 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
312 if (ret) {
313 char *type;
314
315 switch (ret) {
316 case BATADV_HARDIF_BCAST_NORECIPIENT:
317 type = "no neighbor";
318 break;
319 case BATADV_HARDIF_BCAST_DUPFWD:
320 type = "single neighbor is source";
321 break;
322 case BATADV_HARDIF_BCAST_DUPORIG:
323 type = "single neighbor is originator";
324 break;
325 default:
326 type = "unknown";
327 }
328
329 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
330 hard_iface->net_dev->name, type);
331
332 batadv_hardif_put(hard_iface);
333 continue;
334 }
335
336 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
337 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
338 ogm_packet->orig, ntohl(ogm_packet->seqno),
339 ntohl(ogm_packet->throughput), ogm_packet->ttl,
340 hard_iface->net_dev->name,
341 hard_iface->net_dev->dev_addr);
342
343 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
344 skb_tmp = skb_clone(skb, GFP_ATOMIC);
345 if (!skb_tmp) {
346 batadv_hardif_put(hard_iface);
347 break;
348 }
349
350 batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
351 batadv_hardif_put(hard_iface);
352 }
353 rcu_read_unlock();
354
355 consume_skb(skb);
356
357 reschedule:
358 batadv_v_ogm_start_timer(bat_priv);
359 out:
360 return;
361 }
362
363 /**
364 * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
365 * @work: work queue item
366 */
367 static void batadv_v_ogm_send(struct work_struct *work)
368 {
369 struct batadv_priv_bat_v *bat_v;
370 struct batadv_priv *bat_priv;
371
372 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
373 bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
374
375 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
376 batadv_v_ogm_send_softif(bat_priv);
377 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
378 }
379
380 /**
381 * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
382 * @work: work queue item
383 *
384 * Emits aggregated OGM messages in regular intervals.
385 */
386 void batadv_v_ogm_aggr_work(struct work_struct *work)
387 {
388 struct batadv_hard_iface_bat_v *batv;
389 struct batadv_hard_iface *hard_iface;
390
391 batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
392 hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
393
394 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
395 batadv_v_ogm_aggr_send(hard_iface);
396 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
397
398 batadv_v_ogm_start_queue_timer(hard_iface);
399 }
400
401 /**
402 * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
403 * @hard_iface: the interface to prepare
404 *
405 * Takes care of scheduling its own OGM sending routine for this interface.
406 *
407 * Return: 0 on success or a negative error code otherwise
408 */
409 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
410 {
411 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
412
413 batadv_v_ogm_start_queue_timer(hard_iface);
414 batadv_v_ogm_start_timer(bat_priv);
415
416 return 0;
417 }
418
419 /**
420 * batadv_v_ogm_iface_disable() - release OGM interface private resources
421 * @hard_iface: interface for which the resources have to be released
422 */
423 void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
424 {
425 cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
426
427 spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
428 batadv_v_ogm_aggr_list_free(hard_iface);
429 spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
430 }
431
432 /**
433 * batadv_v_ogm_primary_iface_set() - set a new primary interface
434 * @primary_iface: the new primary interface
435 */
436 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
437 {
438 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
439 struct batadv_ogm2_packet *ogm_packet;
440
441 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
442 if (!bat_priv->bat_v.ogm_buff)
443 goto unlock;
444
445 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
446 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
447
448 unlock:
449 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
450 }
451
452 /**
453 * batadv_v_forward_penalty() - apply a penalty to the throughput metric
454 * forwarded with B.A.T.M.A.N. V OGMs
455 * @bat_priv: the bat priv with all the soft interface information
456 * @if_incoming: the interface where the OGM has been received
457 * @if_outgoing: the interface where the OGM has to be forwarded to
458 * @throughput: the current throughput
459 *
460 * Apply a penalty on the current throughput metric value based on the
461 * characteristic of the interface where the OGM has been received.
462 *
463 * Initially the per hardif hop penalty is applied to the throughput. After
464 * that the return value is then computed as follows:
465 * - throughput * 50% if the incoming and outgoing interface are the
466 * same WiFi interface and the throughput is above
467 * 1MBit/s
468 * - throughput if the outgoing interface is the default
469 * interface (i.e. this OGM is processed for the
470 * internal table and not forwarded)
471 * - throughput * node hop penalty otherwise
472 *
473 * Return: the penalised throughput metric.
474 */
475 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
476 struct batadv_hard_iface *if_incoming,
477 struct batadv_hard_iface *if_outgoing,
478 u32 throughput)
479 {
480 int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
481 int hop_penalty = atomic_read(&bat_priv->hop_penalty);
482 int hop_penalty_max = BATADV_TQ_MAX_VALUE;
483
484 /* Apply per hardif hop penalty */
485 throughput = throughput * (hop_penalty_max - if_hop_penalty) /
486 hop_penalty_max;
487
488 /* Don't apply hop penalty in default originator table. */
489 if (if_outgoing == BATADV_IF_DEFAULT)
490 return throughput;
491
492 /* Forwarding on the same WiFi interface cuts the throughput in half
493 * due to the store & forward characteristics of WIFI.
494 * Very low throughput values are the exception.
495 */
496 if (throughput > 10 &&
497 if_incoming == if_outgoing &&
498 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
499 return throughput / 2;
500
501 /* hop penalty of 255 equals 100% */
502 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
503 }
504
505 /**
506 * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
507 * outgoing interface
508 * @bat_priv: the bat priv with all the soft interface information
509 * @ogm_received: previously received OGM to be forwarded
510 * @orig_node: the originator which has been updated
511 * @neigh_node: the neigh_node through with the OGM has been received
512 * @if_incoming: the interface on which this OGM was received on
513 * @if_outgoing: the interface to which the OGM has to be forwarded to
514 *
515 * Forward an OGM to an interface after having altered the throughput metric and
516 * the TTL value contained in it. The original OGM isn't modified.
517 */
518 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
519 const struct batadv_ogm2_packet *ogm_received,
520 struct batadv_orig_node *orig_node,
521 struct batadv_neigh_node *neigh_node,
522 struct batadv_hard_iface *if_incoming,
523 struct batadv_hard_iface *if_outgoing)
524 {
525 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
526 struct batadv_orig_ifinfo *orig_ifinfo = NULL;
527 struct batadv_neigh_node *router = NULL;
528 struct batadv_ogm2_packet *ogm_forward;
529 unsigned char *skb_buff;
530 struct sk_buff *skb;
531 size_t packet_len;
532 u16 tvlv_len;
533
534 /* only forward for specific interfaces, not for the default one. */
535 if (if_outgoing == BATADV_IF_DEFAULT)
536 goto out;
537
538 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
539 if (!orig_ifinfo)
540 goto out;
541
542 /* acquire possibly updated router */
543 router = batadv_orig_router_get(orig_node, if_outgoing);
544
545 /* strict rule: forward packets coming from the best next hop only */
546 if (neigh_node != router)
547 goto out;
548
549 /* don't forward the same seqno twice on one interface */
550 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
551 goto out;
552
553 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
554
555 if (ogm_received->ttl <= 1) {
556 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
557 goto out;
558 }
559
560 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
561 if (!neigh_ifinfo)
562 goto out;
563
564 tvlv_len = ntohs(ogm_received->tvlv_len);
565
566 packet_len = BATADV_OGM2_HLEN + tvlv_len;
567 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
568 ETH_HLEN + packet_len);
569 if (!skb)
570 goto out;
571
572 skb_reserve(skb, ETH_HLEN);
573 skb_buff = skb_put_data(skb, ogm_received, packet_len);
574
575 /* apply forward penalty */
576 ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
577 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
578 ogm_forward->ttl--;
579
580 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
581 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
582 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
583 ogm_forward->ttl, if_incoming->net_dev->name);
584
585 batadv_v_ogm_queue_on_if(skb, if_outgoing);
586
587 out:
588 batadv_orig_ifinfo_put(orig_ifinfo);
589 batadv_neigh_node_put(router);
590 batadv_neigh_ifinfo_put(neigh_ifinfo);
591 }
592
593 /**
594 * batadv_v_ogm_metric_update() - update route metric based on OGM
595 * @bat_priv: the bat priv with all the soft interface information
596 * @ogm2: OGM2 structure
597 * @orig_node: Originator structure for which the OGM has been received
598 * @neigh_node: the neigh_node through with the OGM has been received
599 * @if_incoming: the interface where this packet was received
600 * @if_outgoing: the interface for which the packet should be considered
601 *
602 * Return:
603 * 1 if the OGM is new,
604 * 0 if it is not new but valid,
605 * <0 on error (e.g. old OGM)
606 */
607 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
608 const struct batadv_ogm2_packet *ogm2,
609 struct batadv_orig_node *orig_node,
610 struct batadv_neigh_node *neigh_node,
611 struct batadv_hard_iface *if_incoming,
612 struct batadv_hard_iface *if_outgoing)
613 {
614 struct batadv_orig_ifinfo *orig_ifinfo;
615 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
616 bool protection_started = false;
617 int ret = -EINVAL;
618 u32 path_throughput;
619 s32 seq_diff;
620
621 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
622 if (!orig_ifinfo)
623 goto out;
624
625 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
626
627 if (!hlist_empty(&orig_node->neigh_list) &&
628 batadv_window_protected(bat_priv, seq_diff,
629 BATADV_OGM_MAX_AGE,
630 &orig_ifinfo->batman_seqno_reset,
631 &protection_started)) {
632 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
633 "Drop packet: packet within window protection time from %pM\n",
634 ogm2->orig);
635 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
636 "Last reset: %ld, %ld\n",
637 orig_ifinfo->batman_seqno_reset, jiffies);
638 goto out;
639 }
640
641 /* drop packets with old seqnos, however accept the first packet after
642 * a host has been rebooted.
643 */
644 if (seq_diff < 0 && !protection_started)
645 goto out;
646
647 neigh_node->last_seen = jiffies;
648
649 orig_node->last_seen = jiffies;
650
651 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
652 orig_ifinfo->last_ttl = ogm2->ttl;
653
654 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
655 if (!neigh_ifinfo)
656 goto out;
657
658 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
659 if_outgoing,
660 ntohl(ogm2->throughput));
661 neigh_ifinfo->bat_v.throughput = path_throughput;
662 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
663 neigh_ifinfo->last_ttl = ogm2->ttl;
664
665 if (seq_diff > 0 || protection_started)
666 ret = 1;
667 else
668 ret = 0;
669 out:
670 batadv_orig_ifinfo_put(orig_ifinfo);
671 batadv_neigh_ifinfo_put(neigh_ifinfo);
672
673 return ret;
674 }
675
676 /**
677 * batadv_v_ogm_route_update() - update routes based on OGM
678 * @bat_priv: the bat priv with all the soft interface information
679 * @ethhdr: the Ethernet header of the OGM2
680 * @ogm2: OGM2 structure
681 * @orig_node: Originator structure for which the OGM has been received
682 * @neigh_node: the neigh_node through with the OGM has been received
683 * @if_incoming: the interface where this packet was received
684 * @if_outgoing: the interface for which the packet should be considered
685 *
686 * Return: true if the packet should be forwarded, false otherwise
687 */
688 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
689 const struct ethhdr *ethhdr,
690 const struct batadv_ogm2_packet *ogm2,
691 struct batadv_orig_node *orig_node,
692 struct batadv_neigh_node *neigh_node,
693 struct batadv_hard_iface *if_incoming,
694 struct batadv_hard_iface *if_outgoing)
695 {
696 struct batadv_neigh_node *router = NULL;
697 struct batadv_orig_node *orig_neigh_node;
698 struct batadv_neigh_node *orig_neigh_router = NULL;
699 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
700 u32 router_throughput, neigh_throughput;
701 u32 router_last_seqno;
702 u32 neigh_last_seqno;
703 s32 neigh_seq_diff;
704 bool forward = false;
705
706 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
707 if (!orig_neigh_node)
708 goto out;
709
710 orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
711 if_outgoing);
712
713 /* drop packet if sender is not a direct neighbor and if we
714 * don't route towards it
715 */
716 router = batadv_orig_router_get(orig_node, if_outgoing);
717 if (router && router->orig_node != orig_node && !orig_neigh_router) {
718 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
719 "Drop packet: OGM via unknown neighbor!\n");
720 goto out;
721 }
722
723 /* Mark the OGM to be considered for forwarding, and update routes
724 * if needed.
725 */
726 forward = true;
727
728 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
729 "Searching and updating originator entry of received packet\n");
730
731 /* if this neighbor already is our next hop there is nothing
732 * to change
733 */
734 if (router == neigh_node)
735 goto out;
736
737 /* don't consider neighbours with worse throughput.
738 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
739 * the last received seqno from our best next hop.
740 */
741 if (router) {
742 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
743 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
744
745 /* if these are not allocated, something is wrong. */
746 if (!router_ifinfo || !neigh_ifinfo)
747 goto out;
748
749 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
750 router_last_seqno = router_ifinfo->bat_v.last_seqno;
751 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
752 router_throughput = router_ifinfo->bat_v.throughput;
753 neigh_throughput = neigh_ifinfo->bat_v.throughput;
754
755 if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
756 router_throughput >= neigh_throughput)
757 goto out;
758 }
759
760 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
761 out:
762 batadv_neigh_node_put(router);
763 batadv_neigh_node_put(orig_neigh_router);
764 batadv_orig_node_put(orig_neigh_node);
765 batadv_neigh_ifinfo_put(router_ifinfo);
766 batadv_neigh_ifinfo_put(neigh_ifinfo);
767
768 return forward;
769 }
770
771 /**
772 * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
773 * @bat_priv: the bat priv with all the soft interface information
774 * @ethhdr: the Ethernet header of the OGM2
775 * @ogm2: OGM2 structure
776 * @orig_node: Originator structure for which the OGM has been received
777 * @neigh_node: the neigh_node through with the OGM has been received
778 * @if_incoming: the interface where this packet was received
779 * @if_outgoing: the interface for which the packet should be considered
780 */
781 static void
782 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
783 const struct ethhdr *ethhdr,
784 const struct batadv_ogm2_packet *ogm2,
785 struct batadv_orig_node *orig_node,
786 struct batadv_neigh_node *neigh_node,
787 struct batadv_hard_iface *if_incoming,
788 struct batadv_hard_iface *if_outgoing)
789 {
790 int seqno_age;
791 bool forward;
792
793 /* first, update the metric with according sanity checks */
794 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
795 neigh_node, if_incoming,
796 if_outgoing);
797
798 /* outdated sequence numbers are to be discarded */
799 if (seqno_age < 0)
800 return;
801
802 /* only unknown & newer OGMs contain TVLVs we are interested in */
803 if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
804 batadv_tvlv_containers_process(bat_priv, BATADV_OGM2, orig_node,
805 NULL,
806 (unsigned char *)(ogm2 + 1),
807 ntohs(ogm2->tvlv_len));
808
809 /* if the metric update went through, update routes if needed */
810 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
811 neigh_node, if_incoming,
812 if_outgoing);
813
814 /* if the routes have been processed correctly, check and forward */
815 if (forward)
816 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
817 if_incoming, if_outgoing);
818 }
819
820 /**
821 * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
822 * @buff_pos: current position in the skb
823 * @packet_len: total length of the skb
824 * @ogm2_packet: potential OGM2 in buffer
825 *
826 * Return: true if there is enough space for another OGM, false otherwise.
827 */
828 static bool
829 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
830 const struct batadv_ogm2_packet *ogm2_packet)
831 {
832 int next_buff_pos = 0;
833
834 /* check if there is enough space for the header */
835 next_buff_pos += buff_pos + sizeof(*ogm2_packet);
836 if (next_buff_pos > packet_len)
837 return false;
838
839 /* check if there is enough space for the optional TVLV */
840 next_buff_pos += ntohs(ogm2_packet->tvlv_len);
841
842 return (next_buff_pos <= packet_len) &&
843 (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
844 }
845
846 /**
847 * batadv_v_ogm_process() - process an incoming batman v OGM
848 * @skb: the skb containing the OGM
849 * @ogm_offset: offset to the OGM which should be processed (for aggregates)
850 * @if_incoming: the interface where this packet was received
851 */
852 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
853 struct batadv_hard_iface *if_incoming)
854 {
855 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
856 struct ethhdr *ethhdr;
857 struct batadv_orig_node *orig_node = NULL;
858 struct batadv_hardif_neigh_node *hardif_neigh = NULL;
859 struct batadv_neigh_node *neigh_node = NULL;
860 struct batadv_hard_iface *hard_iface;
861 struct batadv_ogm2_packet *ogm_packet;
862 u32 ogm_throughput, link_throughput, path_throughput;
863 int ret;
864
865 ethhdr = eth_hdr(skb);
866 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
867
868 ogm_throughput = ntohl(ogm_packet->throughput);
869
870 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
871 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
872 ethhdr->h_source, if_incoming->net_dev->name,
873 if_incoming->net_dev->dev_addr, ogm_packet->orig,
874 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
875 ogm_packet->version, ntohs(ogm_packet->tvlv_len));
876
877 if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
878 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
879 "Drop packet: originator packet from ourself\n");
880 return;
881 }
882
883 /* If the throughput metric is 0, immediately drop the packet. No need
884 * to create orig_node / neigh_node for an unusable route.
885 */
886 if (ogm_throughput == 0) {
887 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
888 "Drop packet: originator packet with throughput metric of 0\n");
889 return;
890 }
891
892 /* require ELP packets be to received from this neighbor first */
893 hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
894 if (!hardif_neigh) {
895 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
896 "Drop packet: OGM via unknown neighbor!\n");
897 goto out;
898 }
899
900 orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
901 if (!orig_node)
902 goto out;
903
904 neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
905 ethhdr->h_source);
906 if (!neigh_node)
907 goto out;
908
909 /* Update the received throughput metric to match the link
910 * characteristic:
911 * - If this OGM traveled one hop so far (emitted by single hop
912 * neighbor) the path throughput metric equals the link throughput.
913 * - For OGMs traversing more than hop the path throughput metric is
914 * the smaller of the path throughput and the link throughput.
915 */
916 link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
917 path_throughput = min_t(u32, link_throughput, ogm_throughput);
918 ogm_packet->throughput = htonl(path_throughput);
919
920 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
921 neigh_node, if_incoming,
922 BATADV_IF_DEFAULT);
923
924 rcu_read_lock();
925 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
926 if (hard_iface->if_status != BATADV_IF_ACTIVE)
927 continue;
928
929 if (hard_iface->soft_iface != bat_priv->soft_iface)
930 continue;
931
932 if (!kref_get_unless_zero(&hard_iface->refcount))
933 continue;
934
935 ret = batadv_hardif_no_broadcast(hard_iface,
936 ogm_packet->orig,
937 hardif_neigh->orig);
938
939 if (ret) {
940 char *type;
941
942 switch (ret) {
943 case BATADV_HARDIF_BCAST_NORECIPIENT:
944 type = "no neighbor";
945 break;
946 case BATADV_HARDIF_BCAST_DUPFWD:
947 type = "single neighbor is source";
948 break;
949 case BATADV_HARDIF_BCAST_DUPORIG:
950 type = "single neighbor is originator";
951 break;
952 default:
953 type = "unknown";
954 }
955
956 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
957 ogm_packet->orig, hard_iface->net_dev->name,
958 type);
959
960 batadv_hardif_put(hard_iface);
961 continue;
962 }
963
964 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
965 orig_node, neigh_node,
966 if_incoming, hard_iface);
967
968 batadv_hardif_put(hard_iface);
969 }
970 rcu_read_unlock();
971 out:
972 batadv_orig_node_put(orig_node);
973 batadv_neigh_node_put(neigh_node);
974 batadv_hardif_neigh_put(hardif_neigh);
975 }
976
977 /**
978 * batadv_v_ogm_packet_recv() - OGM2 receiving handler
979 * @skb: the received OGM
980 * @if_incoming: the interface where this OGM has been received
981 *
982 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
983 * (without freeing the skb) on failure
984 */
985 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
986 struct batadv_hard_iface *if_incoming)
987 {
988 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
989 struct batadv_ogm2_packet *ogm_packet;
990 struct ethhdr *ethhdr;
991 int ogm_offset;
992 u8 *packet_pos;
993 int ret = NET_RX_DROP;
994
995 /* did we receive a OGM2 packet on an interface that does not have
996 * B.A.T.M.A.N. V enabled ?
997 */
998 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
999 goto free_skb;
1000
1001 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
1002 goto free_skb;
1003
1004 ethhdr = eth_hdr(skb);
1005 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
1006 goto free_skb;
1007
1008 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1009 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1010 skb->len + ETH_HLEN);
1011
1012 ogm_offset = 0;
1013 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
1014
1015 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
1016 ogm_packet)) {
1017 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
1018
1019 ogm_offset += BATADV_OGM2_HLEN;
1020 ogm_offset += ntohs(ogm_packet->tvlv_len);
1021
1022 packet_pos = skb->data + ogm_offset;
1023 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
1024 }
1025
1026 ret = NET_RX_SUCCESS;
1027
1028 free_skb:
1029 if (ret == NET_RX_SUCCESS)
1030 consume_skb(skb);
1031 else
1032 kfree_skb(skb);
1033
1034 return ret;
1035 }
1036
1037 /**
1038 * batadv_v_ogm_init() - initialise the OGM2 engine
1039 * @bat_priv: the bat priv with all the soft interface information
1040 *
1041 * Return: 0 on success or a negative error code in case of failure
1042 */
1043 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
1044 {
1045 struct batadv_ogm2_packet *ogm_packet;
1046 unsigned char *ogm_buff;
1047 u32 random_seqno;
1048
1049 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
1050 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
1051 if (!ogm_buff)
1052 return -ENOMEM;
1053
1054 bat_priv->bat_v.ogm_buff = ogm_buff;
1055 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
1056 ogm_packet->packet_type = BATADV_OGM2;
1057 ogm_packet->version = BATADV_COMPAT_VERSION;
1058 ogm_packet->ttl = BATADV_TTL;
1059 ogm_packet->flags = BATADV_NO_FLAGS;
1060 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
1061
1062 /* randomize initial seqno to avoid collision */
1063 get_random_bytes(&random_seqno, sizeof(random_seqno));
1064 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
1065 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
1066
1067 mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
1068
1069 return 0;
1070 }
1071
1072 /**
1073 * batadv_v_ogm_free() - free OGM private resources
1074 * @bat_priv: the bat priv with all the soft interface information
1075 */
1076 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
1077 {
1078 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
1079
1080 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
1081
1082 kfree(bat_priv->bat_v.ogm_buff);
1083 bat_priv->bat_v.ogm_buff = NULL;
1084 bat_priv->bat_v.ogm_buff_len = 0;
1085
1086 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
1087 }
1088
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