1 /* Copyright (C) 2013-2017 B.A.T.M.A.N. contributors:
2 *
3 * Antonio Quartulli
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of version 2 of the GNU General Public
7 * License as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include "bat_v_ogm.h"
19 #include "main.h"
20
21 #include <linux/atomic.h>
22 #include <linux/byteorder/generic.h>
23 #include <linux/errno.h>
24 #include <linux/etherdevice.h>
25 #include <linux/fs.h>
26 #include <linux/if_ether.h>
27 #include <linux/jiffies.h>
28 #include <linux/kernel.h>
29 #include <linux/kref.h>
30 #include <linux/list.h>
31 #include <linux/lockdep.h>
32 #include <linux/mutex.h>
33 #include <linux/netdevice.h>
34 #include <linux/random.h>
35 #include <linux/rculist.h>
36 #include <linux/rcupdate.h>
37 #include <linux/skbuff.h>
38 #include <linux/slab.h>
39 #include <linux/stddef.h>
40 #include <linux/string.h>
41 #include <linux/types.h>
42 #include <linux/workqueue.h>
43
44 #include "bat_algo.h"
45 #include "hard-interface.h"
46 #include "hash.h"
47 #include "log.h"
48 #include "originator.h"
49 #include "packet.h"
50 #include "routing.h"
51 #include "send.h"
52 #include "translation-table.h"
53 #include "tvlv.h"
54
55 /**
56 * batadv_v_ogm_orig_get - retrieve and possibly create an originator node
57 * @bat_priv: the bat priv with all the soft interface information
58 * @addr: the address of the originator
59 *
60 * Return: the orig_node corresponding to the specified address. If such object
61 * does not exist it is allocated here. In case of allocation failure returns
62 * NULL.
63 */
batadv_v_ogm_orig_get(struct batadv_priv * bat_priv,const u8 * addr)64 struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
65 const u8 *addr)
66 {
67 struct batadv_orig_node *orig_node;
68 int hash_added;
69
70 orig_node = batadv_orig_hash_find(bat_priv, addr);
71 if (orig_node)
72 return orig_node;
73
74 orig_node = batadv_orig_node_new(bat_priv, addr);
75 if (!orig_node)
76 return NULL;
77
78 kref_get(&orig_node->refcount);
79 hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
80 batadv_choose_orig, orig_node,
81 &orig_node->hash_entry);
82 if (hash_added != 0) {
83 /* remove refcnt for newly created orig_node and hash entry */
84 batadv_orig_node_put(orig_node);
85 batadv_orig_node_put(orig_node);
86 orig_node = NULL;
87 }
88
89 return orig_node;
90 }
91
92 /**
93 * batadv_v_ogm_start_timer - restart the OGM sending timer
94 * @bat_priv: the bat priv with all the soft interface information
95 */
batadv_v_ogm_start_timer(struct batadv_priv * bat_priv)96 static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
97 {
98 unsigned long msecs;
99 /* this function may be invoked in different contexts (ogm rescheduling
100 * or hard_iface activation), but the work timer should not be reset
101 */
102 if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
103 return;
104
105 msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
106 msecs += prandom_u32() % (2 * BATADV_JITTER);
107 queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
108 msecs_to_jiffies(msecs));
109 }
110
111 /**
112 * batadv_v_ogm_send_to_if - send a batman ogm using a given interface
113 * @skb: the OGM to send
114 * @hard_iface: the interface to use to send the OGM
115 */
batadv_v_ogm_send_to_if(struct sk_buff * skb,struct batadv_hard_iface * hard_iface)116 static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
117 struct batadv_hard_iface *hard_iface)
118 {
119 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
120
121 if (hard_iface->if_status != BATADV_IF_ACTIVE)
122 return;
123
124 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
125 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
126 skb->len + ETH_HLEN);
127
128 batadv_send_broadcast_skb(skb, hard_iface);
129 }
130
131 /**
132 * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
133 * @bat_priv: the bat priv with all the soft interface information
134 */
batadv_v_ogm_send_softif(struct batadv_priv * bat_priv)135 static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
136 {
137 struct batadv_hard_iface *hard_iface;
138 struct batadv_ogm2_packet *ogm_packet;
139 struct sk_buff *skb, *skb_tmp;
140 unsigned char *ogm_buff;
141 int ogm_buff_len;
142 u16 tvlv_len = 0;
143 int ret;
144
145 lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
146
147 if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
148 goto out;
149
150 ogm_buff = bat_priv->bat_v.ogm_buff;
151 ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
152 /* tt changes have to be committed before the tvlv data is
153 * appended as it may alter the tt tvlv container
154 */
155 batadv_tt_local_commit_changes(bat_priv);
156 tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
157 &ogm_buff_len,
158 BATADV_OGM2_HLEN);
159
160 bat_priv->bat_v.ogm_buff = ogm_buff;
161 bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
162
163 skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
164 if (!skb)
165 goto reschedule;
166
167 skb_reserve(skb, ETH_HLEN);
168 skb_put_data(skb, ogm_buff, ogm_buff_len);
169
170 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
171 ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
172 atomic_inc(&bat_priv->bat_v.ogm_seqno);
173 ogm_packet->tvlv_len = htons(tvlv_len);
174
175 /* broadcast on every interface */
176 rcu_read_lock();
177 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
178 if (hard_iface->soft_iface != bat_priv->soft_iface)
179 continue;
180
181 if (!kref_get_unless_zero(&hard_iface->refcount))
182 continue;
183
184 ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
185 if (ret) {
186 char *type;
187
188 switch (ret) {
189 case BATADV_HARDIF_BCAST_NORECIPIENT:
190 type = "no neighbor";
191 break;
192 case BATADV_HARDIF_BCAST_DUPFWD:
193 type = "single neighbor is source";
194 break;
195 case BATADV_HARDIF_BCAST_DUPORIG:
196 type = "single neighbor is originator";
197 break;
198 default:
199 type = "unknown";
200 }
201
202 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
203 hard_iface->net_dev->name, type);
204
205 batadv_hardif_put(hard_iface);
206 continue;
207 }
208
209 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
210 "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
211 ogm_packet->orig, ntohl(ogm_packet->seqno),
212 ntohl(ogm_packet->throughput), ogm_packet->ttl,
213 hard_iface->net_dev->name,
214 hard_iface->net_dev->dev_addr);
215
216 /* this skb gets consumed by batadv_v_ogm_send_to_if() */
217 skb_tmp = skb_clone(skb, GFP_ATOMIC);
218 if (!skb_tmp) {
219 batadv_hardif_put(hard_iface);
220 break;
221 }
222
223 batadv_v_ogm_send_to_if(skb_tmp, hard_iface);
224 batadv_hardif_put(hard_iface);
225 }
226 rcu_read_unlock();
227
228 consume_skb(skb);
229
230 reschedule:
231 batadv_v_ogm_start_timer(bat_priv);
232 out:
233 return;
234 }
235
236 /**
237 * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
238 * @work: work queue item
239 */
batadv_v_ogm_send(struct work_struct * work)240 static void batadv_v_ogm_send(struct work_struct *work)
241 {
242 struct batadv_priv_bat_v *bat_v;
243 struct batadv_priv *bat_priv;
244
245 bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
246 bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
247
248 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
249 batadv_v_ogm_send_softif(bat_priv);
250 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
251 }
252
253 /**
254 * batadv_v_ogm_iface_enable - prepare an interface for B.A.T.M.A.N. V
255 * @hard_iface: the interface to prepare
256 *
257 * Takes care of scheduling own OGM sending routine for this interface.
258 *
259 * Return: 0 on success or a negative error code otherwise
260 */
batadv_v_ogm_iface_enable(struct batadv_hard_iface * hard_iface)261 int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
262 {
263 struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
264
265 batadv_v_ogm_start_timer(bat_priv);
266
267 return 0;
268 }
269
270 /**
271 * batadv_v_ogm_primary_iface_set - set a new primary interface
272 * @primary_iface: the new primary interface
273 */
batadv_v_ogm_primary_iface_set(struct batadv_hard_iface * primary_iface)274 void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
275 {
276 struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
277 struct batadv_ogm2_packet *ogm_packet;
278
279 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
280 if (!bat_priv->bat_v.ogm_buff)
281 goto unlock;
282
283 ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
284 ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
285
286 unlock:
287 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
288 }
289
290 /**
291 * batadv_v_forward_penalty - apply a penalty to the throughput metric forwarded
292 * with B.A.T.M.A.N. V OGMs
293 * @bat_priv: the bat priv with all the soft interface information
294 * @if_incoming: the interface where the OGM has been received
295 * @if_outgoing: the interface where the OGM has to be forwarded to
296 * @throughput: the current throughput
297 *
298 * Apply a penalty on the current throughput metric value based on the
299 * characteristic of the interface where the OGM has been received. The return
300 * value is computed as follows:
301 * - throughput * 50% if the incoming and outgoing interface are the
302 * same WiFi interface and the throughput is above
303 * 1MBit/s
304 * - throughput if the outgoing interface is the default
305 * interface (i.e. this OGM is processed for the
306 * internal table and not forwarded)
307 * - throughput * hop penalty otherwise
308 *
309 * Return: the penalised throughput metric.
310 */
batadv_v_forward_penalty(struct batadv_priv * bat_priv,struct batadv_hard_iface * if_incoming,struct batadv_hard_iface * if_outgoing,u32 throughput)311 static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
312 struct batadv_hard_iface *if_incoming,
313 struct batadv_hard_iface *if_outgoing,
314 u32 throughput)
315 {
316 int hop_penalty = atomic_read(&bat_priv->hop_penalty);
317 int hop_penalty_max = BATADV_TQ_MAX_VALUE;
318
319 /* Don't apply hop penalty in default originator table. */
320 if (if_outgoing == BATADV_IF_DEFAULT)
321 return throughput;
322
323 /* Forwarding on the same WiFi interface cuts the throughput in half
324 * due to the store & forward characteristics of WIFI.
325 * Very low throughput values are the exception.
326 */
327 if ((throughput > 10) &&
328 (if_incoming == if_outgoing) &&
329 !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
330 return throughput / 2;
331
332 /* hop penalty of 255 equals 100% */
333 return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
334 }
335
336 /**
337 * batadv_v_ogm_forward - check conditions and forward an OGM to the given
338 * outgoing interface
339 * @bat_priv: the bat priv with all the soft interface information
340 * @ogm_received: previously received OGM to be forwarded
341 * @orig_node: the originator which has been updated
342 * @neigh_node: the neigh_node through with the OGM has been received
343 * @if_incoming: the interface on which this OGM was received on
344 * @if_outgoing: the interface to which the OGM has to be forwarded to
345 *
346 * Forward an OGM to an interface after having altered the throughput metric and
347 * the TTL value contained in it. The original OGM isn't modified.
348 */
batadv_v_ogm_forward(struct batadv_priv * bat_priv,const struct batadv_ogm2_packet * ogm_received,struct batadv_orig_node * orig_node,struct batadv_neigh_node * neigh_node,struct batadv_hard_iface * if_incoming,struct batadv_hard_iface * if_outgoing)349 static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
350 const struct batadv_ogm2_packet *ogm_received,
351 struct batadv_orig_node *orig_node,
352 struct batadv_neigh_node *neigh_node,
353 struct batadv_hard_iface *if_incoming,
354 struct batadv_hard_iface *if_outgoing)
355 {
356 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
357 struct batadv_orig_ifinfo *orig_ifinfo = NULL;
358 struct batadv_neigh_node *router = NULL;
359 struct batadv_ogm2_packet *ogm_forward;
360 unsigned char *skb_buff;
361 struct sk_buff *skb;
362 size_t packet_len;
363 u16 tvlv_len;
364
365 /* only forward for specific interfaces, not for the default one. */
366 if (if_outgoing == BATADV_IF_DEFAULT)
367 goto out;
368
369 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
370 if (!orig_ifinfo)
371 goto out;
372
373 /* acquire possibly updated router */
374 router = batadv_orig_router_get(orig_node, if_outgoing);
375
376 /* strict rule: forward packets coming from the best next hop only */
377 if (neigh_node != router)
378 goto out;
379
380 /* don't forward the same seqno twice on one interface */
381 if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
382 goto out;
383
384 orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
385
386 if (ogm_received->ttl <= 1) {
387 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
388 goto out;
389 }
390
391 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
392 if (!neigh_ifinfo)
393 goto out;
394
395 tvlv_len = ntohs(ogm_received->tvlv_len);
396
397 packet_len = BATADV_OGM2_HLEN + tvlv_len;
398 skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
399 ETH_HLEN + packet_len);
400 if (!skb)
401 goto out;
402
403 skb_reserve(skb, ETH_HLEN);
404 skb_buff = skb_put_data(skb, ogm_received, packet_len);
405
406 /* apply forward penalty */
407 ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
408 ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
409 ogm_forward->ttl--;
410
411 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
412 "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
413 if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
414 ogm_forward->ttl, if_incoming->net_dev->name);
415
416 batadv_v_ogm_send_to_if(skb, if_outgoing);
417
418 out:
419 if (orig_ifinfo)
420 batadv_orig_ifinfo_put(orig_ifinfo);
421 if (router)
422 batadv_neigh_node_put(router);
423 if (neigh_ifinfo)
424 batadv_neigh_ifinfo_put(neigh_ifinfo);
425 }
426
427 /**
428 * batadv_v_ogm_metric_update - update route metric based on OGM
429 * @bat_priv: the bat priv with all the soft interface information
430 * @ogm2: OGM2 structure
431 * @orig_node: Originator structure for which the OGM has been received
432 * @neigh_node: the neigh_node through with the OGM has been received
433 * @if_incoming: the interface where this packet was received
434 * @if_outgoing: the interface for which the packet should be considered
435 *
436 * Return:
437 * 1 if the OGM is new,
438 * 0 if it is not new but valid,
439 * <0 on error (e.g. old OGM)
440 */
batadv_v_ogm_metric_update(struct batadv_priv * bat_priv,const struct batadv_ogm2_packet * ogm2,struct batadv_orig_node * orig_node,struct batadv_neigh_node * neigh_node,struct batadv_hard_iface * if_incoming,struct batadv_hard_iface * if_outgoing)441 static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
442 const struct batadv_ogm2_packet *ogm2,
443 struct batadv_orig_node *orig_node,
444 struct batadv_neigh_node *neigh_node,
445 struct batadv_hard_iface *if_incoming,
446 struct batadv_hard_iface *if_outgoing)
447 {
448 struct batadv_orig_ifinfo *orig_ifinfo;
449 struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
450 bool protection_started = false;
451 int ret = -EINVAL;
452 u32 path_throughput;
453 s32 seq_diff;
454
455 orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
456 if (!orig_ifinfo)
457 goto out;
458
459 seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
460
461 if (!hlist_empty(&orig_node->neigh_list) &&
462 batadv_window_protected(bat_priv, seq_diff,
463 BATADV_OGM_MAX_AGE,
464 &orig_ifinfo->batman_seqno_reset,
465 &protection_started)) {
466 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
467 "Drop packet: packet within window protection time from %pM\n",
468 ogm2->orig);
469 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
470 "Last reset: %ld, %ld\n",
471 orig_ifinfo->batman_seqno_reset, jiffies);
472 goto out;
473 }
474
475 /* drop packets with old seqnos, however accept the first packet after
476 * a host has been rebooted.
477 */
478 if ((seq_diff < 0) && !protection_started)
479 goto out;
480
481 neigh_node->last_seen = jiffies;
482
483 orig_node->last_seen = jiffies;
484
485 orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
486 orig_ifinfo->last_ttl = ogm2->ttl;
487
488 neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
489 if (!neigh_ifinfo)
490 goto out;
491
492 path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
493 if_outgoing,
494 ntohl(ogm2->throughput));
495 neigh_ifinfo->bat_v.throughput = path_throughput;
496 neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
497 neigh_ifinfo->last_ttl = ogm2->ttl;
498
499 if (seq_diff > 0 || protection_started)
500 ret = 1;
501 else
502 ret = 0;
503 out:
504 if (orig_ifinfo)
505 batadv_orig_ifinfo_put(orig_ifinfo);
506 if (neigh_ifinfo)
507 batadv_neigh_ifinfo_put(neigh_ifinfo);
508
509 return ret;
510 }
511
512 /**
513 * batadv_v_ogm_route_update - update routes based on OGM
514 * @bat_priv: the bat priv with all the soft interface information
515 * @ethhdr: the Ethernet header of the OGM2
516 * @ogm2: OGM2 structure
517 * @orig_node: Originator structure for which the OGM has been received
518 * @neigh_node: the neigh_node through with the OGM has been received
519 * @if_incoming: the interface where this packet was received
520 * @if_outgoing: the interface for which the packet should be considered
521 *
522 * Return: true if the packet should be forwarded, false otherwise
523 */
batadv_v_ogm_route_update(struct batadv_priv * bat_priv,const struct ethhdr * ethhdr,const struct batadv_ogm2_packet * ogm2,struct batadv_orig_node * orig_node,struct batadv_neigh_node * neigh_node,struct batadv_hard_iface * if_incoming,struct batadv_hard_iface * if_outgoing)524 static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
525 const struct ethhdr *ethhdr,
526 const struct batadv_ogm2_packet *ogm2,
527 struct batadv_orig_node *orig_node,
528 struct batadv_neigh_node *neigh_node,
529 struct batadv_hard_iface *if_incoming,
530 struct batadv_hard_iface *if_outgoing)
531 {
532 struct batadv_neigh_node *router = NULL;
533 struct batadv_orig_node *orig_neigh_node;
534 struct batadv_neigh_node *orig_neigh_router = NULL;
535 struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
536 u32 router_throughput, neigh_throughput;
537 u32 router_last_seqno;
538 u32 neigh_last_seqno;
539 s32 neigh_seq_diff;
540 bool forward = false;
541
542 orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
543 if (!orig_neigh_node)
544 goto out;
545
546 orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
547 if_outgoing);
548
549 /* drop packet if sender is not a direct neighbor and if we
550 * don't route towards it
551 */
552 router = batadv_orig_router_get(orig_node, if_outgoing);
553 if (router && router->orig_node != orig_node && !orig_neigh_router) {
554 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
555 "Drop packet: OGM via unknown neighbor!\n");
556 goto out;
557 }
558
559 /* Mark the OGM to be considered for forwarding, and update routes
560 * if needed.
561 */
562 forward = true;
563
564 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
565 "Searching and updating originator entry of received packet\n");
566
567 /* if this neighbor already is our next hop there is nothing
568 * to change
569 */
570 if (router == neigh_node)
571 goto out;
572
573 /* don't consider neighbours with worse throughput.
574 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
575 * the last received seqno from our best next hop.
576 */
577 if (router) {
578 router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
579 neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
580
581 /* if these are not allocated, something is wrong. */
582 if (!router_ifinfo || !neigh_ifinfo)
583 goto out;
584
585 neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
586 router_last_seqno = router_ifinfo->bat_v.last_seqno;
587 neigh_seq_diff = neigh_last_seqno - router_last_seqno;
588 router_throughput = router_ifinfo->bat_v.throughput;
589 neigh_throughput = neigh_ifinfo->bat_v.throughput;
590
591 if ((neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF) &&
592 (router_throughput >= neigh_throughput))
593 goto out;
594 }
595
596 batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
597 out:
598 if (router)
599 batadv_neigh_node_put(router);
600 if (orig_neigh_router)
601 batadv_neigh_node_put(orig_neigh_router);
602 if (orig_neigh_node)
603 batadv_orig_node_put(orig_neigh_node);
604 if (router_ifinfo)
605 batadv_neigh_ifinfo_put(router_ifinfo);
606 if (neigh_ifinfo)
607 batadv_neigh_ifinfo_put(neigh_ifinfo);
608
609 return forward;
610 }
611
612 /**
613 * batadv_v_ogm_process_per_outif - process a batman v OGM for an outgoing if
614 * @bat_priv: the bat priv with all the soft interface information
615 * @ethhdr: the Ethernet header of the OGM2
616 * @ogm2: OGM2 structure
617 * @orig_node: Originator structure for which the OGM has been received
618 * @neigh_node: the neigh_node through with the OGM has been received
619 * @if_incoming: the interface where this packet was received
620 * @if_outgoing: the interface for which the packet should be considered
621 */
622 static void
batadv_v_ogm_process_per_outif(struct batadv_priv * bat_priv,const struct ethhdr * ethhdr,const struct batadv_ogm2_packet * ogm2,struct batadv_orig_node * orig_node,struct batadv_neigh_node * neigh_node,struct batadv_hard_iface * if_incoming,struct batadv_hard_iface * if_outgoing)623 batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
624 const struct ethhdr *ethhdr,
625 const struct batadv_ogm2_packet *ogm2,
626 struct batadv_orig_node *orig_node,
627 struct batadv_neigh_node *neigh_node,
628 struct batadv_hard_iface *if_incoming,
629 struct batadv_hard_iface *if_outgoing)
630 {
631 int seqno_age;
632 bool forward;
633
634 /* first, update the metric with according sanity checks */
635 seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
636 neigh_node, if_incoming,
637 if_outgoing);
638
639 /* outdated sequence numbers are to be discarded */
640 if (seqno_age < 0)
641 return;
642
643 /* only unknown & newer OGMs contain TVLVs we are interested in */
644 if ((seqno_age > 0) && (if_outgoing == BATADV_IF_DEFAULT))
645 batadv_tvlv_containers_process(bat_priv, true, orig_node,
646 NULL, NULL,
647 (unsigned char *)(ogm2 + 1),
648 ntohs(ogm2->tvlv_len));
649
650 /* if the metric update went through, update routes if needed */
651 forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
652 neigh_node, if_incoming,
653 if_outgoing);
654
655 /* if the routes have been processed correctly, check and forward */
656 if (forward)
657 batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
658 if_incoming, if_outgoing);
659 }
660
661 /**
662 * batadv_v_ogm_aggr_packet - checks if there is another OGM aggregated
663 * @buff_pos: current position in the skb
664 * @packet_len: total length of the skb
665 * @ogm2_packet: potential OGM2 in buffer
666 *
667 * Return: true if there is enough space for another OGM, false otherwise.
668 */
669 static bool
batadv_v_ogm_aggr_packet(int buff_pos,int packet_len,const struct batadv_ogm2_packet * ogm2_packet)670 batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
671 const struct batadv_ogm2_packet *ogm2_packet)
672 {
673 int next_buff_pos = 0;
674
675 /* check if there is enough space for the header */
676 next_buff_pos += buff_pos + sizeof(*ogm2_packet);
677 if (next_buff_pos > packet_len)
678 return false;
679
680 /* check if there is enough space for the optional TVLV */
681 next_buff_pos += ntohs(ogm2_packet->tvlv_len);
682
683 return (next_buff_pos <= packet_len) &&
684 (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
685 }
686
687 /**
688 * batadv_v_ogm_process - process an incoming batman v OGM
689 * @skb: the skb containing the OGM
690 * @ogm_offset: offset to the OGM which should be processed (for aggregates)
691 * @if_incoming: the interface where this packet was receved
692 */
batadv_v_ogm_process(const struct sk_buff * skb,int ogm_offset,struct batadv_hard_iface * if_incoming)693 static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
694 struct batadv_hard_iface *if_incoming)
695 {
696 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
697 struct ethhdr *ethhdr;
698 struct batadv_orig_node *orig_node = NULL;
699 struct batadv_hardif_neigh_node *hardif_neigh = NULL;
700 struct batadv_neigh_node *neigh_node = NULL;
701 struct batadv_hard_iface *hard_iface;
702 struct batadv_ogm2_packet *ogm_packet;
703 u32 ogm_throughput, link_throughput, path_throughput;
704 int ret;
705
706 ethhdr = eth_hdr(skb);
707 ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
708
709 ogm_throughput = ntohl(ogm_packet->throughput);
710
711 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
712 "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
713 ethhdr->h_source, if_incoming->net_dev->name,
714 if_incoming->net_dev->dev_addr, ogm_packet->orig,
715 ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
716 ogm_packet->version, ntohs(ogm_packet->tvlv_len));
717
718 /* If the throughput metric is 0, immediately drop the packet. No need
719 * to create orig_node / neigh_node for an unusable route.
720 */
721 if (ogm_throughput == 0) {
722 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
723 "Drop packet: originator packet with throughput metric of 0\n");
724 return;
725 }
726
727 /* require ELP packets be to received from this neighbor first */
728 hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
729 if (!hardif_neigh) {
730 batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
731 "Drop packet: OGM via unknown neighbor!\n");
732 goto out;
733 }
734
735 orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
736 if (!orig_node)
737 return;
738
739 neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
740 ethhdr->h_source);
741 if (!neigh_node)
742 goto out;
743
744 /* Update the received throughput metric to match the link
745 * characteristic:
746 * - If this OGM traveled one hop so far (emitted by single hop
747 * neighbor) the path throughput metric equals the link throughput.
748 * - For OGMs traversing more than hop the path throughput metric is
749 * the smaller of the path throughput and the link throughput.
750 */
751 link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
752 path_throughput = min_t(u32, link_throughput, ogm_throughput);
753 ogm_packet->throughput = htonl(path_throughput);
754
755 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
756 neigh_node, if_incoming,
757 BATADV_IF_DEFAULT);
758
759 rcu_read_lock();
760 list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
761 if (hard_iface->if_status != BATADV_IF_ACTIVE)
762 continue;
763
764 if (hard_iface->soft_iface != bat_priv->soft_iface)
765 continue;
766
767 if (!kref_get_unless_zero(&hard_iface->refcount))
768 continue;
769
770 ret = batadv_hardif_no_broadcast(hard_iface,
771 ogm_packet->orig,
772 hardif_neigh->orig);
773
774 if (ret) {
775 char *type;
776
777 switch (ret) {
778 case BATADV_HARDIF_BCAST_NORECIPIENT:
779 type = "no neighbor";
780 break;
781 case BATADV_HARDIF_BCAST_DUPFWD:
782 type = "single neighbor is source";
783 break;
784 case BATADV_HARDIF_BCAST_DUPORIG:
785 type = "single neighbor is originator";
786 break;
787 default:
788 type = "unknown";
789 }
790
791 batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
792 ogm_packet->orig, hard_iface->net_dev->name,
793 type);
794
795 batadv_hardif_put(hard_iface);
796 continue;
797 }
798
799 batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
800 orig_node, neigh_node,
801 if_incoming, hard_iface);
802
803 batadv_hardif_put(hard_iface);
804 }
805 rcu_read_unlock();
806 out:
807 if (orig_node)
808 batadv_orig_node_put(orig_node);
809 if (neigh_node)
810 batadv_neigh_node_put(neigh_node);
811 if (hardif_neigh)
812 batadv_hardif_neigh_put(hardif_neigh);
813 }
814
815 /**
816 * batadv_v_ogm_packet_recv - OGM2 receiving handler
817 * @skb: the received OGM
818 * @if_incoming: the interface where this OGM has been received
819 *
820 * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
821 * (without freeing the skb) on failure
822 */
batadv_v_ogm_packet_recv(struct sk_buff * skb,struct batadv_hard_iface * if_incoming)823 int batadv_v_ogm_packet_recv(struct sk_buff *skb,
824 struct batadv_hard_iface *if_incoming)
825 {
826 struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
827 struct batadv_ogm2_packet *ogm_packet;
828 struct ethhdr *ethhdr = eth_hdr(skb);
829 int ogm_offset;
830 u8 *packet_pos;
831 int ret = NET_RX_DROP;
832
833 /* did we receive a OGM2 packet on an interface that does not have
834 * B.A.T.M.A.N. V enabled ?
835 */
836 if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
837 goto free_skb;
838
839 if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
840 goto free_skb;
841
842 if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
843 goto free_skb;
844
845 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
846
847 if (batadv_is_my_mac(bat_priv, ogm_packet->orig))
848 goto free_skb;
849
850 batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
851 batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
852 skb->len + ETH_HLEN);
853
854 ogm_offset = 0;
855 ogm_packet = (struct batadv_ogm2_packet *)skb->data;
856
857 while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
858 ogm_packet)) {
859 batadv_v_ogm_process(skb, ogm_offset, if_incoming);
860
861 ogm_offset += BATADV_OGM2_HLEN;
862 ogm_offset += ntohs(ogm_packet->tvlv_len);
863
864 packet_pos = skb->data + ogm_offset;
865 ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
866 }
867
868 ret = NET_RX_SUCCESS;
869
870 free_skb:
871 if (ret == NET_RX_SUCCESS)
872 consume_skb(skb);
873 else
874 kfree_skb(skb);
875
876 return ret;
877 }
878
879 /**
880 * batadv_v_ogm_init - initialise the OGM2 engine
881 * @bat_priv: the bat priv with all the soft interface information
882 *
883 * Return: 0 on success or a negative error code in case of failure
884 */
batadv_v_ogm_init(struct batadv_priv * bat_priv)885 int batadv_v_ogm_init(struct batadv_priv *bat_priv)
886 {
887 struct batadv_ogm2_packet *ogm_packet;
888 unsigned char *ogm_buff;
889 u32 random_seqno;
890
891 bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
892 ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
893 if (!ogm_buff)
894 return -ENOMEM;
895
896 bat_priv->bat_v.ogm_buff = ogm_buff;
897 ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
898 ogm_packet->packet_type = BATADV_OGM2;
899 ogm_packet->version = BATADV_COMPAT_VERSION;
900 ogm_packet->ttl = BATADV_TTL;
901 ogm_packet->flags = BATADV_NO_FLAGS;
902 ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
903
904 /* randomize initial seqno to avoid collision */
905 get_random_bytes(&random_seqno, sizeof(random_seqno));
906 atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
907 INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
908
909 mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
910
911 return 0;
912 }
913
914 /**
915 * batadv_v_ogm_free - free OGM private resources
916 * @bat_priv: the bat priv with all the soft interface information
917 */
batadv_v_ogm_free(struct batadv_priv * bat_priv)918 void batadv_v_ogm_free(struct batadv_priv *bat_priv)
919 {
920 cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
921
922 mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
923
924 kfree(bat_priv->bat_v.ogm_buff);
925 bat_priv->bat_v.ogm_buff = NULL;
926 bat_priv->bat_v.ogm_buff_len = 0;
927
928 mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
929 }
930