xref: /openbmc/linux/net/batman-adv/bat_iv_ogm.c (revision e23feb16)
1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner, Simon Wunderlich
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, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17  * 02110-1301, USA
18  */
19 
20 #include "main.h"
21 #include "translation-table.h"
22 #include "originator.h"
23 #include "routing.h"
24 #include "gateway_common.h"
25 #include "gateway_client.h"
26 #include "hard-interface.h"
27 #include "send.h"
28 #include "bat_algo.h"
29 #include "network-coding.h"
30 
31 
32 /**
33  * batadv_dup_status - duplicate status
34  * @BATADV_NO_DUP: the packet is a duplicate
35  * @BATADV_ORIG_DUP: OGM is a duplicate in the originator (but not for the
36  *  neighbor)
37  * @BATADV_NEIGH_DUP: OGM is a duplicate for the neighbor
38  * @BATADV_PROTECTED: originator is currently protected (after reboot)
39  */
40 enum batadv_dup_status {
41 	BATADV_NO_DUP = 0,
42 	BATADV_ORIG_DUP,
43 	BATADV_NEIGH_DUP,
44 	BATADV_PROTECTED,
45 };
46 
47 /**
48  * batadv_ring_buffer_set - update the ring buffer with the given value
49  * @lq_recv: pointer to the ring buffer
50  * @lq_index: index to store the value at
51  * @value: value to store in the ring buffer
52  */
53 static void batadv_ring_buffer_set(uint8_t lq_recv[], uint8_t *lq_index,
54 				   uint8_t value)
55 {
56 	lq_recv[*lq_index] = value;
57 	*lq_index = (*lq_index + 1) % BATADV_TQ_GLOBAL_WINDOW_SIZE;
58 }
59 
60 /**
61  * batadv_ring_buffer_set - compute the average of all non-zero values stored
62  * in the given ring buffer
63  * @lq_recv: pointer to the ring buffer
64  *
65  * Returns computed average value.
66  */
67 static uint8_t batadv_ring_buffer_avg(const uint8_t lq_recv[])
68 {
69 	const uint8_t *ptr;
70 	uint16_t count = 0, i = 0, sum = 0;
71 
72 	ptr = lq_recv;
73 
74 	while (i < BATADV_TQ_GLOBAL_WINDOW_SIZE) {
75 		if (*ptr != 0) {
76 			count++;
77 			sum += *ptr;
78 		}
79 
80 		i++;
81 		ptr++;
82 	}
83 
84 	if (count == 0)
85 		return 0;
86 
87 	return (uint8_t)(sum / count);
88 }
89 
90 static struct batadv_neigh_node *
91 batadv_iv_ogm_neigh_new(struct batadv_hard_iface *hard_iface,
92 			const uint8_t *neigh_addr,
93 			struct batadv_orig_node *orig_node,
94 			struct batadv_orig_node *orig_neigh)
95 {
96 	struct batadv_neigh_node *neigh_node;
97 
98 	neigh_node = batadv_neigh_node_new(hard_iface, neigh_addr);
99 	if (!neigh_node)
100 		goto out;
101 
102 	INIT_LIST_HEAD(&neigh_node->bonding_list);
103 
104 	neigh_node->orig_node = orig_neigh;
105 	neigh_node->if_incoming = hard_iface;
106 
107 	spin_lock_bh(&orig_node->neigh_list_lock);
108 	hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
109 	spin_unlock_bh(&orig_node->neigh_list_lock);
110 
111 out:
112 	return neigh_node;
113 }
114 
115 static int batadv_iv_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
116 {
117 	struct batadv_ogm_packet *batadv_ogm_packet;
118 	unsigned char *ogm_buff;
119 	uint32_t random_seqno;
120 	int res = -ENOMEM;
121 
122 	/* randomize initial seqno to avoid collision */
123 	get_random_bytes(&random_seqno, sizeof(random_seqno));
124 	atomic_set(&hard_iface->bat_iv.ogm_seqno, random_seqno);
125 
126 	hard_iface->bat_iv.ogm_buff_len = BATADV_OGM_HLEN;
127 	ogm_buff = kmalloc(hard_iface->bat_iv.ogm_buff_len, GFP_ATOMIC);
128 	if (!ogm_buff)
129 		goto out;
130 
131 	hard_iface->bat_iv.ogm_buff = ogm_buff;
132 
133 	batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
134 	batadv_ogm_packet->header.packet_type = BATADV_IV_OGM;
135 	batadv_ogm_packet->header.version = BATADV_COMPAT_VERSION;
136 	batadv_ogm_packet->header.ttl = 2;
137 	batadv_ogm_packet->flags = BATADV_NO_FLAGS;
138 	batadv_ogm_packet->tq = BATADV_TQ_MAX_VALUE;
139 	batadv_ogm_packet->tt_num_changes = 0;
140 	batadv_ogm_packet->ttvn = 0;
141 
142 	res = 0;
143 
144 out:
145 	return res;
146 }
147 
148 static void batadv_iv_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
149 {
150 	kfree(hard_iface->bat_iv.ogm_buff);
151 	hard_iface->bat_iv.ogm_buff = NULL;
152 }
153 
154 static void batadv_iv_ogm_iface_update_mac(struct batadv_hard_iface *hard_iface)
155 {
156 	struct batadv_ogm_packet *batadv_ogm_packet;
157 	unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
158 
159 	batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
160 	memcpy(batadv_ogm_packet->orig,
161 	       hard_iface->net_dev->dev_addr, ETH_ALEN);
162 	memcpy(batadv_ogm_packet->prev_sender,
163 	       hard_iface->net_dev->dev_addr, ETH_ALEN);
164 }
165 
166 static void
167 batadv_iv_ogm_primary_iface_set(struct batadv_hard_iface *hard_iface)
168 {
169 	struct batadv_ogm_packet *batadv_ogm_packet;
170 	unsigned char *ogm_buff = hard_iface->bat_iv.ogm_buff;
171 
172 	batadv_ogm_packet = (struct batadv_ogm_packet *)ogm_buff;
173 	batadv_ogm_packet->flags = BATADV_PRIMARIES_FIRST_HOP;
174 	batadv_ogm_packet->header.ttl = BATADV_TTL;
175 }
176 
177 /* when do we schedule our own ogm to be sent */
178 static unsigned long
179 batadv_iv_ogm_emit_send_time(const struct batadv_priv *bat_priv)
180 {
181 	unsigned int msecs;
182 
183 	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
184 	msecs += prandom_u32() % (2 * BATADV_JITTER);
185 
186 	return jiffies + msecs_to_jiffies(msecs);
187 }
188 
189 /* when do we schedule a ogm packet to be sent */
190 static unsigned long batadv_iv_ogm_fwd_send_time(void)
191 {
192 	return jiffies + msecs_to_jiffies(prandom_u32() % (BATADV_JITTER / 2));
193 }
194 
195 /* apply hop penalty for a normal link */
196 static uint8_t batadv_hop_penalty(uint8_t tq,
197 				  const struct batadv_priv *bat_priv)
198 {
199 	int hop_penalty = atomic_read(&bat_priv->hop_penalty);
200 	int new_tq;
201 
202 	new_tq = tq * (BATADV_TQ_MAX_VALUE - hop_penalty);
203 	new_tq /= BATADV_TQ_MAX_VALUE;
204 
205 	return new_tq;
206 }
207 
208 /* is there another aggregated packet here? */
209 static int batadv_iv_ogm_aggr_packet(int buff_pos, int packet_len,
210 				     int tt_num_changes)
211 {
212 	int next_buff_pos = 0;
213 
214 	next_buff_pos += buff_pos + BATADV_OGM_HLEN;
215 	next_buff_pos += batadv_tt_len(tt_num_changes);
216 
217 	return (next_buff_pos <= packet_len) &&
218 	       (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
219 }
220 
221 /* send a batman ogm to a given interface */
222 static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
223 				     struct batadv_hard_iface *hard_iface)
224 {
225 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
226 	char *fwd_str;
227 	uint8_t packet_num;
228 	int16_t buff_pos;
229 	struct batadv_ogm_packet *batadv_ogm_packet;
230 	struct sk_buff *skb;
231 	uint8_t *packet_pos;
232 
233 	if (hard_iface->if_status != BATADV_IF_ACTIVE)
234 		return;
235 
236 	packet_num = 0;
237 	buff_pos = 0;
238 	packet_pos = forw_packet->skb->data;
239 	batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
240 
241 	/* adjust all flags and log packets */
242 	while (batadv_iv_ogm_aggr_packet(buff_pos, forw_packet->packet_len,
243 					 batadv_ogm_packet->tt_num_changes)) {
244 		/* we might have aggregated direct link packets with an
245 		 * ordinary base packet
246 		 */
247 		if (forw_packet->direct_link_flags & BIT(packet_num) &&
248 		    forw_packet->if_incoming == hard_iface)
249 			batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
250 		else
251 			batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
252 
253 		if (packet_num > 0 || !forw_packet->own)
254 			fwd_str = "Forwarding";
255 		else
256 			fwd_str = "Sending own";
257 
258 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
259 			   "%s %spacket (originator %pM, seqno %u, TQ %d, TTL %d, IDF %s, ttvn %d) on interface %s [%pM]\n",
260 			   fwd_str, (packet_num > 0 ? "aggregated " : ""),
261 			   batadv_ogm_packet->orig,
262 			   ntohl(batadv_ogm_packet->seqno),
263 			   batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl,
264 			   (batadv_ogm_packet->flags & BATADV_DIRECTLINK ?
265 			    "on" : "off"),
266 			   batadv_ogm_packet->ttvn, hard_iface->net_dev->name,
267 			   hard_iface->net_dev->dev_addr);
268 
269 		buff_pos += BATADV_OGM_HLEN;
270 		buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
271 		packet_num++;
272 		packet_pos = forw_packet->skb->data + buff_pos;
273 		batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
274 	}
275 
276 	/* create clone because function is called more than once */
277 	skb = skb_clone(forw_packet->skb, GFP_ATOMIC);
278 	if (skb) {
279 		batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
280 		batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
281 				   skb->len + ETH_HLEN);
282 		batadv_send_skb_packet(skb, hard_iface, batadv_broadcast_addr);
283 	}
284 }
285 
286 /* send a batman ogm packet */
287 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
288 {
289 	struct batadv_hard_iface *hard_iface;
290 	struct net_device *soft_iface;
291 	struct batadv_priv *bat_priv;
292 	struct batadv_hard_iface *primary_if = NULL;
293 	struct batadv_ogm_packet *batadv_ogm_packet;
294 	unsigned char directlink;
295 	uint8_t *packet_pos;
296 
297 	packet_pos = forw_packet->skb->data;
298 	batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
299 	directlink = (batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0);
300 
301 	if (!forw_packet->if_incoming) {
302 		pr_err("Error - can't forward packet: incoming iface not specified\n");
303 		goto out;
304 	}
305 
306 	soft_iface = forw_packet->if_incoming->soft_iface;
307 	bat_priv = netdev_priv(soft_iface);
308 
309 	if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
310 		goto out;
311 
312 	primary_if = batadv_primary_if_get_selected(bat_priv);
313 	if (!primary_if)
314 		goto out;
315 
316 	/* multihomed peer assumed
317 	 * non-primary OGMs are only broadcasted on their interface
318 	 */
319 	if ((directlink && (batadv_ogm_packet->header.ttl == 1)) ||
320 	    (forw_packet->own && (forw_packet->if_incoming != primary_if))) {
321 		/* FIXME: what about aggregated packets ? */
322 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
323 			   "%s packet (originator %pM, seqno %u, TTL %d) on interface %s [%pM]\n",
324 			   (forw_packet->own ? "Sending own" : "Forwarding"),
325 			   batadv_ogm_packet->orig,
326 			   ntohl(batadv_ogm_packet->seqno),
327 			   batadv_ogm_packet->header.ttl,
328 			   forw_packet->if_incoming->net_dev->name,
329 			   forw_packet->if_incoming->net_dev->dev_addr);
330 
331 		/* skb is only used once and than forw_packet is free'd */
332 		batadv_send_skb_packet(forw_packet->skb,
333 				       forw_packet->if_incoming,
334 				       batadv_broadcast_addr);
335 		forw_packet->skb = NULL;
336 
337 		goto out;
338 	}
339 
340 	/* broadcast on every interface */
341 	rcu_read_lock();
342 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
343 		if (hard_iface->soft_iface != soft_iface)
344 			continue;
345 
346 		batadv_iv_ogm_send_to_if(forw_packet, hard_iface);
347 	}
348 	rcu_read_unlock();
349 
350 out:
351 	if (primary_if)
352 		batadv_hardif_free_ref(primary_if);
353 }
354 
355 /* return true if new_packet can be aggregated with forw_packet */
356 static bool
357 batadv_iv_ogm_can_aggregate(const struct batadv_ogm_packet *new_bat_ogm_packet,
358 			    struct batadv_priv *bat_priv,
359 			    int packet_len, unsigned long send_time,
360 			    bool directlink,
361 			    const struct batadv_hard_iface *if_incoming,
362 			    const struct batadv_forw_packet *forw_packet)
363 {
364 	struct batadv_ogm_packet *batadv_ogm_packet;
365 	int aggregated_bytes = forw_packet->packet_len + packet_len;
366 	struct batadv_hard_iface *primary_if = NULL;
367 	bool res = false;
368 	unsigned long aggregation_end_time;
369 
370 	batadv_ogm_packet = (struct batadv_ogm_packet *)forw_packet->skb->data;
371 	aggregation_end_time = send_time;
372 	aggregation_end_time += msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
373 
374 	/* we can aggregate the current packet to this aggregated packet
375 	 * if:
376 	 *
377 	 * - the send time is within our MAX_AGGREGATION_MS time
378 	 * - the resulting packet wont be bigger than
379 	 *   MAX_AGGREGATION_BYTES
380 	 */
381 	if (time_before(send_time, forw_packet->send_time) &&
382 	    time_after_eq(aggregation_end_time, forw_packet->send_time) &&
383 	    (aggregated_bytes <= BATADV_MAX_AGGREGATION_BYTES)) {
384 		/* check aggregation compatibility
385 		 * -> direct link packets are broadcasted on
386 		 *    their interface only
387 		 * -> aggregate packet if the current packet is
388 		 *    a "global" packet as well as the base
389 		 *    packet
390 		 */
391 		primary_if = batadv_primary_if_get_selected(bat_priv);
392 		if (!primary_if)
393 			goto out;
394 
395 		/* packets without direct link flag and high TTL
396 		 * are flooded through the net
397 		 */
398 		if ((!directlink) &&
399 		    (!(batadv_ogm_packet->flags & BATADV_DIRECTLINK)) &&
400 		    (batadv_ogm_packet->header.ttl != 1) &&
401 
402 		    /* own packets originating non-primary
403 		     * interfaces leave only that interface
404 		     */
405 		    ((!forw_packet->own) ||
406 		     (forw_packet->if_incoming == primary_if))) {
407 			res = true;
408 			goto out;
409 		}
410 
411 		/* if the incoming packet is sent via this one
412 		 * interface only - we still can aggregate
413 		 */
414 		if ((directlink) &&
415 		    (new_bat_ogm_packet->header.ttl == 1) &&
416 		    (forw_packet->if_incoming == if_incoming) &&
417 
418 		    /* packets from direct neighbors or
419 		     * own secondary interface packets
420 		     * (= secondary interface packets in general)
421 		     */
422 		    (batadv_ogm_packet->flags & BATADV_DIRECTLINK ||
423 		     (forw_packet->own &&
424 		      forw_packet->if_incoming != primary_if))) {
425 			res = true;
426 			goto out;
427 		}
428 	}
429 
430 out:
431 	if (primary_if)
432 		batadv_hardif_free_ref(primary_if);
433 	return res;
434 }
435 
436 /* create a new aggregated packet and add this packet to it */
437 static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
438 					int packet_len, unsigned long send_time,
439 					bool direct_link,
440 					struct batadv_hard_iface *if_incoming,
441 					int own_packet)
442 {
443 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
444 	struct batadv_forw_packet *forw_packet_aggr;
445 	unsigned char *skb_buff;
446 	unsigned int skb_size;
447 
448 	if (!atomic_inc_not_zero(&if_incoming->refcount))
449 		return;
450 
451 	/* own packet should always be scheduled */
452 	if (!own_packet) {
453 		if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
454 			batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
455 				   "batman packet queue full\n");
456 			goto out;
457 		}
458 	}
459 
460 	forw_packet_aggr = kmalloc(sizeof(*forw_packet_aggr), GFP_ATOMIC);
461 	if (!forw_packet_aggr) {
462 		if (!own_packet)
463 			atomic_inc(&bat_priv->batman_queue_left);
464 		goto out;
465 	}
466 
467 	if ((atomic_read(&bat_priv->aggregated_ogms)) &&
468 	    (packet_len < BATADV_MAX_AGGREGATION_BYTES))
469 		skb_size = BATADV_MAX_AGGREGATION_BYTES;
470 	else
471 		skb_size = packet_len;
472 
473 	skb_size += ETH_HLEN;
474 
475 	forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size);
476 	if (!forw_packet_aggr->skb) {
477 		if (!own_packet)
478 			atomic_inc(&bat_priv->batman_queue_left);
479 		kfree(forw_packet_aggr);
480 		goto out;
481 	}
482 	forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
483 	skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
484 
485 	skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
486 	forw_packet_aggr->packet_len = packet_len;
487 	memcpy(skb_buff, packet_buff, packet_len);
488 
489 	forw_packet_aggr->own = own_packet;
490 	forw_packet_aggr->if_incoming = if_incoming;
491 	forw_packet_aggr->num_packets = 0;
492 	forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;
493 	forw_packet_aggr->send_time = send_time;
494 
495 	/* save packet direct link flag status */
496 	if (direct_link)
497 		forw_packet_aggr->direct_link_flags |= 1;
498 
499 	/* add new packet to packet list */
500 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
501 	hlist_add_head(&forw_packet_aggr->list, &bat_priv->forw_bat_list);
502 	spin_unlock_bh(&bat_priv->forw_bat_list_lock);
503 
504 	/* start timer for this packet */
505 	INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work,
506 			  batadv_send_outstanding_bat_ogm_packet);
507 	queue_delayed_work(batadv_event_workqueue,
508 			   &forw_packet_aggr->delayed_work,
509 			   send_time - jiffies);
510 
511 	return;
512 out:
513 	batadv_hardif_free_ref(if_incoming);
514 }
515 
516 /* aggregate a new packet into the existing ogm packet */
517 static void batadv_iv_ogm_aggregate(struct batadv_forw_packet *forw_packet_aggr,
518 				    const unsigned char *packet_buff,
519 				    int packet_len, bool direct_link)
520 {
521 	unsigned char *skb_buff;
522 	unsigned long new_direct_link_flag;
523 
524 	skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
525 	memcpy(skb_buff, packet_buff, packet_len);
526 	forw_packet_aggr->packet_len += packet_len;
527 	forw_packet_aggr->num_packets++;
528 
529 	/* save packet direct link flag status */
530 	if (direct_link) {
531 		new_direct_link_flag = BIT(forw_packet_aggr->num_packets);
532 		forw_packet_aggr->direct_link_flags |= new_direct_link_flag;
533 	}
534 }
535 
536 static void batadv_iv_ogm_queue_add(struct batadv_priv *bat_priv,
537 				    unsigned char *packet_buff,
538 				    int packet_len,
539 				    struct batadv_hard_iface *if_incoming,
540 				    int own_packet, unsigned long send_time)
541 {
542 	/* _aggr -> pointer to the packet we want to aggregate with
543 	 * _pos -> pointer to the position in the queue
544 	 */
545 	struct batadv_forw_packet *forw_packet_aggr = NULL;
546 	struct batadv_forw_packet *forw_packet_pos = NULL;
547 	struct batadv_ogm_packet *batadv_ogm_packet;
548 	bool direct_link;
549 	unsigned long max_aggregation_jiffies;
550 
551 	batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
552 	direct_link = batadv_ogm_packet->flags & BATADV_DIRECTLINK ? 1 : 0;
553 	max_aggregation_jiffies = msecs_to_jiffies(BATADV_MAX_AGGREGATION_MS);
554 
555 	/* find position for the packet in the forward queue */
556 	spin_lock_bh(&bat_priv->forw_bat_list_lock);
557 	/* own packets are not to be aggregated */
558 	if ((atomic_read(&bat_priv->aggregated_ogms)) && (!own_packet)) {
559 		hlist_for_each_entry(forw_packet_pos,
560 				     &bat_priv->forw_bat_list, list) {
561 			if (batadv_iv_ogm_can_aggregate(batadv_ogm_packet,
562 							bat_priv, packet_len,
563 							send_time, direct_link,
564 							if_incoming,
565 							forw_packet_pos)) {
566 				forw_packet_aggr = forw_packet_pos;
567 				break;
568 			}
569 		}
570 	}
571 
572 	/* nothing to aggregate with - either aggregation disabled or no
573 	 * suitable aggregation packet found
574 	 */
575 	if (!forw_packet_aggr) {
576 		/* the following section can run without the lock */
577 		spin_unlock_bh(&bat_priv->forw_bat_list_lock);
578 
579 		/* if we could not aggregate this packet with one of the others
580 		 * we hold it back for a while, so that it might be aggregated
581 		 * later on
582 		 */
583 		if (!own_packet && atomic_read(&bat_priv->aggregated_ogms))
584 			send_time += max_aggregation_jiffies;
585 
586 		batadv_iv_ogm_aggregate_new(packet_buff, packet_len,
587 					    send_time, direct_link,
588 					    if_incoming, own_packet);
589 	} else {
590 		batadv_iv_ogm_aggregate(forw_packet_aggr, packet_buff,
591 					packet_len, direct_link);
592 		spin_unlock_bh(&bat_priv->forw_bat_list_lock);
593 	}
594 }
595 
596 static void batadv_iv_ogm_forward(struct batadv_orig_node *orig_node,
597 				  const struct ethhdr *ethhdr,
598 				  struct batadv_ogm_packet *batadv_ogm_packet,
599 				  bool is_single_hop_neigh,
600 				  bool is_from_best_next_hop,
601 				  struct batadv_hard_iface *if_incoming)
602 {
603 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
604 	uint8_t tt_num_changes;
605 
606 	if (batadv_ogm_packet->header.ttl <= 1) {
607 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
608 		return;
609 	}
610 
611 	if (!is_from_best_next_hop) {
612 		/* Mark the forwarded packet when it is not coming from our
613 		 * best next hop. We still need to forward the packet for our
614 		 * neighbor link quality detection to work in case the packet
615 		 * originated from a single hop neighbor. Otherwise we can
616 		 * simply drop the ogm.
617 		 */
618 		if (is_single_hop_neigh)
619 			batadv_ogm_packet->flags |= BATADV_NOT_BEST_NEXT_HOP;
620 		else
621 			return;
622 	}
623 
624 	tt_num_changes = batadv_ogm_packet->tt_num_changes;
625 
626 	batadv_ogm_packet->header.ttl--;
627 	memcpy(batadv_ogm_packet->prev_sender, ethhdr->h_source, ETH_ALEN);
628 
629 	/* apply hop penalty */
630 	batadv_ogm_packet->tq = batadv_hop_penalty(batadv_ogm_packet->tq,
631 						   bat_priv);
632 
633 	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
634 		   "Forwarding packet: tq: %i, ttl: %i\n",
635 		   batadv_ogm_packet->tq, batadv_ogm_packet->header.ttl);
636 
637 	/* switch of primaries first hop flag when forwarding */
638 	batadv_ogm_packet->flags &= ~BATADV_PRIMARIES_FIRST_HOP;
639 	if (is_single_hop_neigh)
640 		batadv_ogm_packet->flags |= BATADV_DIRECTLINK;
641 	else
642 		batadv_ogm_packet->flags &= ~BATADV_DIRECTLINK;
643 
644 	batadv_iv_ogm_queue_add(bat_priv, (unsigned char *)batadv_ogm_packet,
645 				BATADV_OGM_HLEN + batadv_tt_len(tt_num_changes),
646 				if_incoming, 0, batadv_iv_ogm_fwd_send_time());
647 }
648 
649 /**
650  * batadv_iv_ogm_slide_own_bcast_window - bitshift own OGM broadcast windows for
651  * the given interface
652  * @hard_iface: the interface for which the windows have to be shifted
653  */
654 static void
655 batadv_iv_ogm_slide_own_bcast_window(struct batadv_hard_iface *hard_iface)
656 {
657 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
658 	struct batadv_hashtable *hash = bat_priv->orig_hash;
659 	struct hlist_head *head;
660 	struct batadv_orig_node *orig_node;
661 	unsigned long *word;
662 	uint32_t i;
663 	size_t word_index;
664 	uint8_t *w;
665 
666 	for (i = 0; i < hash->size; i++) {
667 		head = &hash->table[i];
668 
669 		rcu_read_lock();
670 		hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
671 			spin_lock_bh(&orig_node->ogm_cnt_lock);
672 			word_index = hard_iface->if_num * BATADV_NUM_WORDS;
673 			word = &(orig_node->bcast_own[word_index]);
674 
675 			batadv_bit_get_packet(bat_priv, word, 1, 0);
676 			w = &orig_node->bcast_own_sum[hard_iface->if_num];
677 			*w = bitmap_weight(word, BATADV_TQ_LOCAL_WINDOW_SIZE);
678 			spin_unlock_bh(&orig_node->ogm_cnt_lock);
679 		}
680 		rcu_read_unlock();
681 	}
682 }
683 
684 static void batadv_iv_ogm_schedule(struct batadv_hard_iface *hard_iface)
685 {
686 	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
687 	unsigned char **ogm_buff = &hard_iface->bat_iv.ogm_buff;
688 	struct batadv_ogm_packet *batadv_ogm_packet;
689 	struct batadv_hard_iface *primary_if;
690 	int *ogm_buff_len = &hard_iface->bat_iv.ogm_buff_len;
691 	int vis_server, tt_num_changes = 0;
692 	uint32_t seqno;
693 	uint8_t bandwidth;
694 
695 	vis_server = atomic_read(&bat_priv->vis_mode);
696 	primary_if = batadv_primary_if_get_selected(bat_priv);
697 
698 	if (hard_iface == primary_if)
699 		tt_num_changes = batadv_tt_append_diff(bat_priv, ogm_buff,
700 						       ogm_buff_len,
701 						       BATADV_OGM_HLEN);
702 
703 	batadv_ogm_packet = (struct batadv_ogm_packet *)(*ogm_buff);
704 
705 	/* change sequence number to network order */
706 	seqno = (uint32_t)atomic_read(&hard_iface->bat_iv.ogm_seqno);
707 	batadv_ogm_packet->seqno = htonl(seqno);
708 	atomic_inc(&hard_iface->bat_iv.ogm_seqno);
709 
710 	batadv_ogm_packet->ttvn = atomic_read(&bat_priv->tt.vn);
711 	batadv_ogm_packet->tt_crc = htons(bat_priv->tt.local_crc);
712 	if (tt_num_changes >= 0)
713 		batadv_ogm_packet->tt_num_changes = tt_num_changes;
714 
715 	if (vis_server == BATADV_VIS_TYPE_SERVER_SYNC)
716 		batadv_ogm_packet->flags |= BATADV_VIS_SERVER;
717 	else
718 		batadv_ogm_packet->flags &= ~BATADV_VIS_SERVER;
719 
720 	if (hard_iface == primary_if &&
721 	    atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_SERVER) {
722 		bandwidth = (uint8_t)atomic_read(&bat_priv->gw_bandwidth);
723 		batadv_ogm_packet->gw_flags = bandwidth;
724 	} else {
725 		batadv_ogm_packet->gw_flags = BATADV_NO_FLAGS;
726 	}
727 
728 	batadv_iv_ogm_slide_own_bcast_window(hard_iface);
729 	batadv_iv_ogm_queue_add(bat_priv, hard_iface->bat_iv.ogm_buff,
730 				hard_iface->bat_iv.ogm_buff_len, hard_iface, 1,
731 				batadv_iv_ogm_emit_send_time(bat_priv));
732 
733 	if (primary_if)
734 		batadv_hardif_free_ref(primary_if);
735 }
736 
737 static void
738 batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv,
739 			  struct batadv_orig_node *orig_node,
740 			  const struct ethhdr *ethhdr,
741 			  const struct batadv_ogm_packet *batadv_ogm_packet,
742 			  struct batadv_hard_iface *if_incoming,
743 			  const unsigned char *tt_buff,
744 			  enum batadv_dup_status dup_status)
745 {
746 	struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
747 	struct batadv_neigh_node *router = NULL;
748 	struct batadv_orig_node *orig_node_tmp;
749 	int if_num;
750 	uint8_t sum_orig, sum_neigh;
751 	uint8_t *neigh_addr;
752 	uint8_t tq_avg;
753 
754 	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
755 		   "update_originator(): Searching and updating originator entry of received packet\n");
756 
757 	rcu_read_lock();
758 	hlist_for_each_entry_rcu(tmp_neigh_node,
759 				 &orig_node->neigh_list, list) {
760 		neigh_addr = tmp_neigh_node->addr;
761 		if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
762 		    tmp_neigh_node->if_incoming == if_incoming &&
763 		    atomic_inc_not_zero(&tmp_neigh_node->refcount)) {
764 			if (WARN(neigh_node, "too many matching neigh_nodes"))
765 				batadv_neigh_node_free_ref(neigh_node);
766 			neigh_node = tmp_neigh_node;
767 			continue;
768 		}
769 
770 		if (dup_status != BATADV_NO_DUP)
771 			continue;
772 
773 		spin_lock_bh(&tmp_neigh_node->lq_update_lock);
774 		batadv_ring_buffer_set(tmp_neigh_node->tq_recv,
775 				       &tmp_neigh_node->tq_index, 0);
776 		tq_avg = batadv_ring_buffer_avg(tmp_neigh_node->tq_recv);
777 		tmp_neigh_node->tq_avg = tq_avg;
778 		spin_unlock_bh(&tmp_neigh_node->lq_update_lock);
779 	}
780 
781 	if (!neigh_node) {
782 		struct batadv_orig_node *orig_tmp;
783 
784 		orig_tmp = batadv_get_orig_node(bat_priv, ethhdr->h_source);
785 		if (!orig_tmp)
786 			goto unlock;
787 
788 		neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
789 						     ethhdr->h_source,
790 						     orig_node, orig_tmp);
791 
792 		batadv_orig_node_free_ref(orig_tmp);
793 		if (!neigh_node)
794 			goto unlock;
795 	} else
796 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
797 			   "Updating existing last-hop neighbor of originator\n");
798 
799 	rcu_read_unlock();
800 
801 	orig_node->flags = batadv_ogm_packet->flags;
802 	neigh_node->last_seen = jiffies;
803 
804 	spin_lock_bh(&neigh_node->lq_update_lock);
805 	batadv_ring_buffer_set(neigh_node->tq_recv,
806 			       &neigh_node->tq_index,
807 			       batadv_ogm_packet->tq);
808 	neigh_node->tq_avg = batadv_ring_buffer_avg(neigh_node->tq_recv);
809 	spin_unlock_bh(&neigh_node->lq_update_lock);
810 
811 	if (dup_status == BATADV_NO_DUP) {
812 		orig_node->last_ttl = batadv_ogm_packet->header.ttl;
813 		neigh_node->last_ttl = batadv_ogm_packet->header.ttl;
814 	}
815 
816 	batadv_bonding_candidate_add(orig_node, neigh_node);
817 
818 	/* if this neighbor already is our next hop there is nothing
819 	 * to change
820 	 */
821 	router = batadv_orig_node_get_router(orig_node);
822 	if (router == neigh_node)
823 		goto update_tt;
824 
825 	/* if this neighbor does not offer a better TQ we won't consider it */
826 	if (router && (router->tq_avg > neigh_node->tq_avg))
827 		goto update_tt;
828 
829 	/* if the TQ is the same and the link not more symmetric we
830 	 * won't consider it either
831 	 */
832 	if (router && (neigh_node->tq_avg == router->tq_avg)) {
833 		orig_node_tmp = router->orig_node;
834 		spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
835 		if_num = router->if_incoming->if_num;
836 		sum_orig = orig_node_tmp->bcast_own_sum[if_num];
837 		spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
838 
839 		orig_node_tmp = neigh_node->orig_node;
840 		spin_lock_bh(&orig_node_tmp->ogm_cnt_lock);
841 		if_num = neigh_node->if_incoming->if_num;
842 		sum_neigh = orig_node_tmp->bcast_own_sum[if_num];
843 		spin_unlock_bh(&orig_node_tmp->ogm_cnt_lock);
844 
845 		if (sum_orig >= sum_neigh)
846 			goto update_tt;
847 	}
848 
849 	batadv_update_route(bat_priv, orig_node, neigh_node);
850 
851 update_tt:
852 	/* I have to check for transtable changes only if the OGM has been
853 	 * sent through a primary interface
854 	 */
855 	if (((batadv_ogm_packet->orig != ethhdr->h_source) &&
856 	     (batadv_ogm_packet->header.ttl > 2)) ||
857 	    (batadv_ogm_packet->flags & BATADV_PRIMARIES_FIRST_HOP))
858 		batadv_tt_update_orig(bat_priv, orig_node, tt_buff,
859 				      batadv_ogm_packet->tt_num_changes,
860 				      batadv_ogm_packet->ttvn,
861 				      ntohs(batadv_ogm_packet->tt_crc));
862 
863 	if (orig_node->gw_flags != batadv_ogm_packet->gw_flags)
864 		batadv_gw_node_update(bat_priv, orig_node,
865 				      batadv_ogm_packet->gw_flags);
866 
867 	orig_node->gw_flags = batadv_ogm_packet->gw_flags;
868 
869 	/* restart gateway selection if fast or late switching was enabled */
870 	if ((orig_node->gw_flags) &&
871 	    (atomic_read(&bat_priv->gw_mode) == BATADV_GW_MODE_CLIENT) &&
872 	    (atomic_read(&bat_priv->gw_sel_class) > 2))
873 		batadv_gw_check_election(bat_priv, orig_node);
874 
875 	goto out;
876 
877 unlock:
878 	rcu_read_unlock();
879 out:
880 	if (neigh_node)
881 		batadv_neigh_node_free_ref(neigh_node);
882 	if (router)
883 		batadv_neigh_node_free_ref(router);
884 }
885 
886 static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node,
887 				 struct batadv_orig_node *orig_neigh_node,
888 				 struct batadv_ogm_packet *batadv_ogm_packet,
889 				 struct batadv_hard_iface *if_incoming)
890 {
891 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
892 	struct batadv_neigh_node *neigh_node = NULL, *tmp_neigh_node;
893 	uint8_t total_count;
894 	uint8_t orig_eq_count, neigh_rq_count, neigh_rq_inv, tq_own;
895 	unsigned int neigh_rq_inv_cube, neigh_rq_max_cube;
896 	int tq_asym_penalty, inv_asym_penalty, ret = 0;
897 	unsigned int combined_tq;
898 
899 	/* find corresponding one hop neighbor */
900 	rcu_read_lock();
901 	hlist_for_each_entry_rcu(tmp_neigh_node,
902 				 &orig_neigh_node->neigh_list, list) {
903 		if (!batadv_compare_eth(tmp_neigh_node->addr,
904 					orig_neigh_node->orig))
905 			continue;
906 
907 		if (tmp_neigh_node->if_incoming != if_incoming)
908 			continue;
909 
910 		if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
911 			continue;
912 
913 		neigh_node = tmp_neigh_node;
914 		break;
915 	}
916 	rcu_read_unlock();
917 
918 	if (!neigh_node)
919 		neigh_node = batadv_iv_ogm_neigh_new(if_incoming,
920 						     orig_neigh_node->orig,
921 						     orig_neigh_node,
922 						     orig_neigh_node);
923 
924 	if (!neigh_node)
925 		goto out;
926 
927 	/* if orig_node is direct neighbor update neigh_node last_seen */
928 	if (orig_node == orig_neigh_node)
929 		neigh_node->last_seen = jiffies;
930 
931 	orig_node->last_seen = jiffies;
932 
933 	/* find packet count of corresponding one hop neighbor */
934 	spin_lock_bh(&orig_node->ogm_cnt_lock);
935 	orig_eq_count = orig_neigh_node->bcast_own_sum[if_incoming->if_num];
936 	neigh_rq_count = neigh_node->real_packet_count;
937 	spin_unlock_bh(&orig_node->ogm_cnt_lock);
938 
939 	/* pay attention to not get a value bigger than 100 % */
940 	if (orig_eq_count > neigh_rq_count)
941 		total_count = neigh_rq_count;
942 	else
943 		total_count = orig_eq_count;
944 
945 	/* if we have too few packets (too less data) we set tq_own to zero
946 	 * if we receive too few packets it is not considered bidirectional
947 	 */
948 	if (total_count < BATADV_TQ_LOCAL_BIDRECT_SEND_MINIMUM ||
949 	    neigh_rq_count < BATADV_TQ_LOCAL_BIDRECT_RECV_MINIMUM)
950 		tq_own = 0;
951 	else
952 		/* neigh_node->real_packet_count is never zero as we
953 		 * only purge old information when getting new
954 		 * information
955 		 */
956 		tq_own = (BATADV_TQ_MAX_VALUE * total_count) /	neigh_rq_count;
957 
958 	/* 1 - ((1-x) ** 3), normalized to TQ_MAX_VALUE this does
959 	 * affect the nearly-symmetric links only a little, but
960 	 * punishes asymmetric links more.  This will give a value
961 	 * between 0 and TQ_MAX_VALUE
962 	 */
963 	neigh_rq_inv = BATADV_TQ_LOCAL_WINDOW_SIZE - neigh_rq_count;
964 	neigh_rq_inv_cube = neigh_rq_inv * neigh_rq_inv * neigh_rq_inv;
965 	neigh_rq_max_cube = BATADV_TQ_LOCAL_WINDOW_SIZE *
966 			    BATADV_TQ_LOCAL_WINDOW_SIZE *
967 			    BATADV_TQ_LOCAL_WINDOW_SIZE;
968 	inv_asym_penalty = BATADV_TQ_MAX_VALUE * neigh_rq_inv_cube;
969 	inv_asym_penalty /= neigh_rq_max_cube;
970 	tq_asym_penalty = BATADV_TQ_MAX_VALUE - inv_asym_penalty;
971 
972 	combined_tq = batadv_ogm_packet->tq * tq_own * tq_asym_penalty;
973 	combined_tq /= BATADV_TQ_MAX_VALUE * BATADV_TQ_MAX_VALUE;
974 	batadv_ogm_packet->tq = combined_tq;
975 
976 	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
977 		   "bidirectional: orig = %-15pM neigh = %-15pM => own_bcast = %2i, real recv = %2i, local tq: %3i, asym_penalty: %3i, total tq: %3i\n",
978 		   orig_node->orig, orig_neigh_node->orig, total_count,
979 		   neigh_rq_count, tq_own,
980 		   tq_asym_penalty, batadv_ogm_packet->tq);
981 
982 	/* if link has the minimum required transmission quality
983 	 * consider it bidirectional
984 	 */
985 	if (batadv_ogm_packet->tq >= BATADV_TQ_TOTAL_BIDRECT_LIMIT)
986 		ret = 1;
987 
988 out:
989 	if (neigh_node)
990 		batadv_neigh_node_free_ref(neigh_node);
991 	return ret;
992 }
993 
994 /**
995  * batadv_iv_ogm_update_seqnos -  process a batman packet for all interfaces,
996  *  adjust the sequence number and find out whether it is a duplicate
997  * @ethhdr: ethernet header of the packet
998  * @batadv_ogm_packet: OGM packet to be considered
999  * @if_incoming: interface on which the OGM packet was received
1000  *
1001  * Returns duplicate status as enum batadv_dup_status
1002  */
1003 static enum batadv_dup_status
1004 batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
1005 			    const struct batadv_ogm_packet *batadv_ogm_packet,
1006 			    const struct batadv_hard_iface *if_incoming)
1007 {
1008 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1009 	struct batadv_orig_node *orig_node;
1010 	struct batadv_neigh_node *tmp_neigh_node;
1011 	int is_dup;
1012 	int32_t seq_diff;
1013 	int need_update = 0;
1014 	int set_mark;
1015 	enum batadv_dup_status ret = BATADV_NO_DUP;
1016 	uint32_t seqno = ntohl(batadv_ogm_packet->seqno);
1017 	uint8_t *neigh_addr;
1018 	uint8_t packet_count;
1019 
1020 	orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1021 	if (!orig_node)
1022 		return BATADV_NO_DUP;
1023 
1024 	spin_lock_bh(&orig_node->ogm_cnt_lock);
1025 	seq_diff = seqno - orig_node->last_real_seqno;
1026 
1027 	/* signalize caller that the packet is to be dropped. */
1028 	if (!hlist_empty(&orig_node->neigh_list) &&
1029 	    batadv_window_protected(bat_priv, seq_diff,
1030 				    &orig_node->batman_seqno_reset)) {
1031 		ret = BATADV_PROTECTED;
1032 		goto out;
1033 	}
1034 
1035 	rcu_read_lock();
1036 	hlist_for_each_entry_rcu(tmp_neigh_node,
1037 				 &orig_node->neigh_list, list) {
1038 		neigh_addr = tmp_neigh_node->addr;
1039 		is_dup = batadv_test_bit(tmp_neigh_node->real_bits,
1040 					 orig_node->last_real_seqno,
1041 					 seqno);
1042 
1043 		if (batadv_compare_eth(neigh_addr, ethhdr->h_source) &&
1044 		    tmp_neigh_node->if_incoming == if_incoming) {
1045 			set_mark = 1;
1046 			if (is_dup)
1047 				ret = BATADV_NEIGH_DUP;
1048 		} else {
1049 			set_mark = 0;
1050 			if (is_dup && (ret != BATADV_NEIGH_DUP))
1051 				ret = BATADV_ORIG_DUP;
1052 		}
1053 
1054 		/* if the window moved, set the update flag. */
1055 		need_update |= batadv_bit_get_packet(bat_priv,
1056 						     tmp_neigh_node->real_bits,
1057 						     seq_diff, set_mark);
1058 
1059 		packet_count = bitmap_weight(tmp_neigh_node->real_bits,
1060 					     BATADV_TQ_LOCAL_WINDOW_SIZE);
1061 		tmp_neigh_node->real_packet_count = packet_count;
1062 	}
1063 	rcu_read_unlock();
1064 
1065 	if (need_update) {
1066 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1067 			   "updating last_seqno: old %u, new %u\n",
1068 			   orig_node->last_real_seqno, seqno);
1069 		orig_node->last_real_seqno = seqno;
1070 	}
1071 
1072 out:
1073 	spin_unlock_bh(&orig_node->ogm_cnt_lock);
1074 	batadv_orig_node_free_ref(orig_node);
1075 	return ret;
1076 }
1077 
1078 static void batadv_iv_ogm_process(const struct ethhdr *ethhdr,
1079 				  struct batadv_ogm_packet *batadv_ogm_packet,
1080 				  const unsigned char *tt_buff,
1081 				  struct batadv_hard_iface *if_incoming)
1082 {
1083 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1084 	struct batadv_hard_iface *hard_iface;
1085 	struct batadv_orig_node *orig_neigh_node, *orig_node;
1086 	struct batadv_neigh_node *router = NULL, *router_router = NULL;
1087 	struct batadv_neigh_node *orig_neigh_router = NULL;
1088 	int has_directlink_flag;
1089 	int is_my_addr = 0, is_my_orig = 0, is_my_oldorig = 0;
1090 	int is_bidirect;
1091 	bool is_single_hop_neigh = false;
1092 	bool is_from_best_next_hop = false;
1093 	int sameseq, similar_ttl;
1094 	enum batadv_dup_status dup_status;
1095 	uint32_t if_incoming_seqno;
1096 	uint8_t *prev_sender;
1097 
1098 	/* Silently drop when the batman packet is actually not a
1099 	 * correct packet.
1100 	 *
1101 	 * This might happen if a packet is padded (e.g. Ethernet has a
1102 	 * minimum frame length of 64 byte) and the aggregation interprets
1103 	 * it as an additional length.
1104 	 *
1105 	 * TODO: A more sane solution would be to have a bit in the
1106 	 * batadv_ogm_packet to detect whether the packet is the last
1107 	 * packet in an aggregation.  Here we expect that the padding
1108 	 * is always zero (or not 0x01)
1109 	 */
1110 	if (batadv_ogm_packet->header.packet_type != BATADV_IV_OGM)
1111 		return;
1112 
1113 	/* could be changed by schedule_own_packet() */
1114 	if_incoming_seqno = atomic_read(&if_incoming->bat_iv.ogm_seqno);
1115 
1116 	if (batadv_ogm_packet->flags & BATADV_DIRECTLINK)
1117 		has_directlink_flag = 1;
1118 	else
1119 		has_directlink_flag = 0;
1120 
1121 	if (batadv_compare_eth(ethhdr->h_source, batadv_ogm_packet->orig))
1122 		is_single_hop_neigh = true;
1123 
1124 	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1125 		   "Received BATMAN packet via NB: %pM, IF: %s [%pM] (from OG: %pM, via prev OG: %pM, seqno %u, ttvn %u, crc %#.4x, changes %u, tq %d, TTL %d, V %d, IDF %d)\n",
1126 		   ethhdr->h_source, if_incoming->net_dev->name,
1127 		   if_incoming->net_dev->dev_addr, batadv_ogm_packet->orig,
1128 		   batadv_ogm_packet->prev_sender,
1129 		   ntohl(batadv_ogm_packet->seqno), batadv_ogm_packet->ttvn,
1130 		   ntohs(batadv_ogm_packet->tt_crc),
1131 		   batadv_ogm_packet->tt_num_changes, batadv_ogm_packet->tq,
1132 		   batadv_ogm_packet->header.ttl,
1133 		   batadv_ogm_packet->header.version, has_directlink_flag);
1134 
1135 	rcu_read_lock();
1136 	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
1137 		if (hard_iface->if_status != BATADV_IF_ACTIVE)
1138 			continue;
1139 
1140 		if (hard_iface->soft_iface != if_incoming->soft_iface)
1141 			continue;
1142 
1143 		if (batadv_compare_eth(ethhdr->h_source,
1144 				       hard_iface->net_dev->dev_addr))
1145 			is_my_addr = 1;
1146 
1147 		if (batadv_compare_eth(batadv_ogm_packet->orig,
1148 				       hard_iface->net_dev->dev_addr))
1149 			is_my_orig = 1;
1150 
1151 		if (batadv_compare_eth(batadv_ogm_packet->prev_sender,
1152 				       hard_iface->net_dev->dev_addr))
1153 			is_my_oldorig = 1;
1154 	}
1155 	rcu_read_unlock();
1156 
1157 	if (is_my_addr) {
1158 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1159 			   "Drop packet: received my own broadcast (sender: %pM)\n",
1160 			   ethhdr->h_source);
1161 		return;
1162 	}
1163 
1164 	if (is_my_orig) {
1165 		unsigned long *word;
1166 		int offset;
1167 		int32_t bit_pos;
1168 		int16_t if_num;
1169 		uint8_t *weight;
1170 
1171 		orig_neigh_node = batadv_get_orig_node(bat_priv,
1172 						       ethhdr->h_source);
1173 		if (!orig_neigh_node)
1174 			return;
1175 
1176 		/* neighbor has to indicate direct link and it has to
1177 		 * come via the corresponding interface
1178 		 * save packet seqno for bidirectional check
1179 		 */
1180 		if (has_directlink_flag &&
1181 		    batadv_compare_eth(if_incoming->net_dev->dev_addr,
1182 				       batadv_ogm_packet->orig)) {
1183 			if_num = if_incoming->if_num;
1184 			offset = if_num * BATADV_NUM_WORDS;
1185 
1186 			spin_lock_bh(&orig_neigh_node->ogm_cnt_lock);
1187 			word = &(orig_neigh_node->bcast_own[offset]);
1188 			bit_pos = if_incoming_seqno - 2;
1189 			bit_pos -= ntohl(batadv_ogm_packet->seqno);
1190 			batadv_set_bit(word, bit_pos);
1191 			weight = &orig_neigh_node->bcast_own_sum[if_num];
1192 			*weight = bitmap_weight(word,
1193 						BATADV_TQ_LOCAL_WINDOW_SIZE);
1194 			spin_unlock_bh(&orig_neigh_node->ogm_cnt_lock);
1195 		}
1196 
1197 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1198 			   "Drop packet: originator packet from myself (via neighbor)\n");
1199 		batadv_orig_node_free_ref(orig_neigh_node);
1200 		return;
1201 	}
1202 
1203 	if (is_my_oldorig) {
1204 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1205 			   "Drop packet: ignoring all rebroadcast echos (sender: %pM)\n",
1206 			   ethhdr->h_source);
1207 		return;
1208 	}
1209 
1210 	if (batadv_ogm_packet->flags & BATADV_NOT_BEST_NEXT_HOP) {
1211 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1212 			   "Drop packet: ignoring all packets not forwarded from the best next hop (sender: %pM)\n",
1213 			   ethhdr->h_source);
1214 		return;
1215 	}
1216 
1217 	orig_node = batadv_get_orig_node(bat_priv, batadv_ogm_packet->orig);
1218 	if (!orig_node)
1219 		return;
1220 
1221 	dup_status = batadv_iv_ogm_update_seqnos(ethhdr, batadv_ogm_packet,
1222 						 if_incoming);
1223 
1224 	if (dup_status == BATADV_PROTECTED) {
1225 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1226 			   "Drop packet: packet within seqno protection time (sender: %pM)\n",
1227 			   ethhdr->h_source);
1228 		goto out;
1229 	}
1230 
1231 	if (batadv_ogm_packet->tq == 0) {
1232 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1233 			   "Drop packet: originator packet with tq equal 0\n");
1234 		goto out;
1235 	}
1236 
1237 	router = batadv_orig_node_get_router(orig_node);
1238 	if (router)
1239 		router_router = batadv_orig_node_get_router(router->orig_node);
1240 
1241 	if ((router && router->tq_avg != 0) &&
1242 	    (batadv_compare_eth(router->addr, ethhdr->h_source)))
1243 		is_from_best_next_hop = true;
1244 
1245 	prev_sender = batadv_ogm_packet->prev_sender;
1246 	/* avoid temporary routing loops */
1247 	if (router && router_router &&
1248 	    (batadv_compare_eth(router->addr, prev_sender)) &&
1249 	    !(batadv_compare_eth(batadv_ogm_packet->orig, prev_sender)) &&
1250 	    (batadv_compare_eth(router->addr, router_router->addr))) {
1251 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1252 			   "Drop packet: ignoring all rebroadcast packets that may make me loop (sender: %pM)\n",
1253 			   ethhdr->h_source);
1254 		goto out;
1255 	}
1256 
1257 	/* if sender is a direct neighbor the sender mac equals
1258 	 * originator mac
1259 	 */
1260 	if (is_single_hop_neigh)
1261 		orig_neigh_node = orig_node;
1262 	else
1263 		orig_neigh_node = batadv_get_orig_node(bat_priv,
1264 						       ethhdr->h_source);
1265 
1266 	if (!orig_neigh_node)
1267 		goto out;
1268 
1269 	/* Update nc_nodes of the originator */
1270 	batadv_nc_update_nc_node(bat_priv, orig_node, orig_neigh_node,
1271 				 batadv_ogm_packet, is_single_hop_neigh);
1272 
1273 	orig_neigh_router = batadv_orig_node_get_router(orig_neigh_node);
1274 
1275 	/* drop packet if sender is not a direct neighbor and if we
1276 	 * don't route towards it
1277 	 */
1278 	if (!is_single_hop_neigh && (!orig_neigh_router)) {
1279 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1280 			   "Drop packet: OGM via unknown neighbor!\n");
1281 		goto out_neigh;
1282 	}
1283 
1284 	is_bidirect = batadv_iv_ogm_calc_tq(orig_node, orig_neigh_node,
1285 					    batadv_ogm_packet, if_incoming);
1286 
1287 	batadv_bonding_save_primary(orig_node, orig_neigh_node,
1288 				    batadv_ogm_packet);
1289 
1290 	/* update ranking if it is not a duplicate or has the same
1291 	 * seqno and similar ttl as the non-duplicate
1292 	 */
1293 	sameseq = orig_node->last_real_seqno == ntohl(batadv_ogm_packet->seqno);
1294 	similar_ttl = orig_node->last_ttl - 3 <= batadv_ogm_packet->header.ttl;
1295 	if (is_bidirect && ((dup_status == BATADV_NO_DUP) ||
1296 			    (sameseq && similar_ttl)))
1297 		batadv_iv_ogm_orig_update(bat_priv, orig_node, ethhdr,
1298 					  batadv_ogm_packet, if_incoming,
1299 					  tt_buff, dup_status);
1300 
1301 	/* is single hop (direct) neighbor */
1302 	if (is_single_hop_neigh) {
1303 		/* mark direct link on incoming interface */
1304 		batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1305 				      is_single_hop_neigh,
1306 				      is_from_best_next_hop, if_incoming);
1307 
1308 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1309 			   "Forwarding packet: rebroadcast neighbor packet with direct link flag\n");
1310 		goto out_neigh;
1311 	}
1312 
1313 	/* multihop originator */
1314 	if (!is_bidirect) {
1315 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1316 			   "Drop packet: not received via bidirectional link\n");
1317 		goto out_neigh;
1318 	}
1319 
1320 	if (dup_status == BATADV_NEIGH_DUP) {
1321 		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1322 			   "Drop packet: duplicate packet received\n");
1323 		goto out_neigh;
1324 	}
1325 
1326 	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
1327 		   "Forwarding packet: rebroadcast originator packet\n");
1328 	batadv_iv_ogm_forward(orig_node, ethhdr, batadv_ogm_packet,
1329 			      is_single_hop_neigh, is_from_best_next_hop,
1330 			      if_incoming);
1331 
1332 out_neigh:
1333 	if ((orig_neigh_node) && (!is_single_hop_neigh))
1334 		batadv_orig_node_free_ref(orig_neigh_node);
1335 out:
1336 	if (router)
1337 		batadv_neigh_node_free_ref(router);
1338 	if (router_router)
1339 		batadv_neigh_node_free_ref(router_router);
1340 	if (orig_neigh_router)
1341 		batadv_neigh_node_free_ref(orig_neigh_router);
1342 
1343 	batadv_orig_node_free_ref(orig_node);
1344 }
1345 
1346 static int batadv_iv_ogm_receive(struct sk_buff *skb,
1347 				 struct batadv_hard_iface *if_incoming)
1348 {
1349 	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
1350 	struct batadv_ogm_packet *batadv_ogm_packet;
1351 	struct ethhdr *ethhdr;
1352 	int buff_pos = 0, packet_len;
1353 	unsigned char *tt_buff, *packet_buff;
1354 	bool ret;
1355 	uint8_t *packet_pos;
1356 
1357 	ret = batadv_check_management_packet(skb, if_incoming, BATADV_OGM_HLEN);
1358 	if (!ret)
1359 		return NET_RX_DROP;
1360 
1361 	/* did we receive a B.A.T.M.A.N. IV OGM packet on an interface
1362 	 * that does not have B.A.T.M.A.N. IV enabled ?
1363 	 */
1364 	if (bat_priv->bat_algo_ops->bat_ogm_emit != batadv_iv_ogm_emit)
1365 		return NET_RX_DROP;
1366 
1367 	batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
1368 	batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
1369 			   skb->len + ETH_HLEN);
1370 
1371 	packet_len = skb_headlen(skb);
1372 	ethhdr = eth_hdr(skb);
1373 	packet_buff = skb->data;
1374 	batadv_ogm_packet = (struct batadv_ogm_packet *)packet_buff;
1375 
1376 	/* unpack the aggregated packets and process them one by one */
1377 	while (batadv_iv_ogm_aggr_packet(buff_pos, packet_len,
1378 					 batadv_ogm_packet->tt_num_changes)) {
1379 		tt_buff = packet_buff + buff_pos + BATADV_OGM_HLEN;
1380 
1381 		batadv_iv_ogm_process(ethhdr, batadv_ogm_packet, tt_buff,
1382 				      if_incoming);
1383 
1384 		buff_pos += BATADV_OGM_HLEN;
1385 		buff_pos += batadv_tt_len(batadv_ogm_packet->tt_num_changes);
1386 
1387 		packet_pos = packet_buff + buff_pos;
1388 		batadv_ogm_packet = (struct batadv_ogm_packet *)packet_pos;
1389 	}
1390 
1391 	kfree_skb(skb);
1392 	return NET_RX_SUCCESS;
1393 }
1394 
1395 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
1396 	.name = "BATMAN_IV",
1397 	.bat_iface_enable = batadv_iv_ogm_iface_enable,
1398 	.bat_iface_disable = batadv_iv_ogm_iface_disable,
1399 	.bat_iface_update_mac = batadv_iv_ogm_iface_update_mac,
1400 	.bat_primary_iface_set = batadv_iv_ogm_primary_iface_set,
1401 	.bat_ogm_schedule = batadv_iv_ogm_schedule,
1402 	.bat_ogm_emit = batadv_iv_ogm_emit,
1403 };
1404 
1405 int __init batadv_iv_init(void)
1406 {
1407 	int ret;
1408 
1409 	/* batman originator packet */
1410 	ret = batadv_recv_handler_register(BATADV_IV_OGM,
1411 					   batadv_iv_ogm_receive);
1412 	if (ret < 0)
1413 		goto out;
1414 
1415 	ret = batadv_algo_register(&batadv_batman_iv);
1416 	if (ret < 0)
1417 		goto handler_unregister;
1418 
1419 	goto out;
1420 
1421 handler_unregister:
1422 	batadv_recv_handler_unregister(BATADV_IV_OGM);
1423 out:
1424 	return ret;
1425 }
1426