1 /* Copyright (C) 2007-2013 B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner, Simon Wunderlich, 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, 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 "soft-interface.h"
23 #include "hard-interface.h"
24 #include "send.h"
25 #include "hash.h"
26 #include "originator.h"
27 #include "routing.h"
28 #include "bridge_loop_avoidance.h"
29 
30 #include <linux/crc16.h>
31 
32 /* hash class keys */
33 static struct lock_class_key batadv_tt_local_hash_lock_class_key;
34 static struct lock_class_key batadv_tt_global_hash_lock_class_key;
35 
36 static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
37 				 struct batadv_orig_node *orig_node);
38 static void batadv_tt_purge(struct work_struct *work);
39 static void
40 batadv_tt_global_del_orig_list(struct batadv_tt_global_entry *tt_global_entry);
41 static void batadv_tt_global_del(struct batadv_priv *bat_priv,
42 				 struct batadv_orig_node *orig_node,
43 				 const unsigned char *addr,
44 				 const char *message, bool roaming);
45 
46 /* returns 1 if they are the same mac addr */
47 static int batadv_compare_tt(const struct hlist_node *node, const void *data2)
48 {
49 	const void *data1 = container_of(node, struct batadv_tt_common_entry,
50 					 hash_entry);
51 
52 	return (memcmp(data1, data2, ETH_ALEN) == 0 ? 1 : 0);
53 }
54 
55 static struct batadv_tt_common_entry *
56 batadv_tt_hash_find(struct batadv_hashtable *hash, const void *data)
57 {
58 	struct hlist_head *head;
59 	struct batadv_tt_common_entry *tt_common_entry;
60 	struct batadv_tt_common_entry *tt_common_entry_tmp = NULL;
61 	uint32_t index;
62 
63 	if (!hash)
64 		return NULL;
65 
66 	index = batadv_choose_orig(data, hash->size);
67 	head = &hash->table[index];
68 
69 	rcu_read_lock();
70 	hlist_for_each_entry_rcu(tt_common_entry, head, hash_entry) {
71 		if (!batadv_compare_eth(tt_common_entry, data))
72 			continue;
73 
74 		if (!atomic_inc_not_zero(&tt_common_entry->refcount))
75 			continue;
76 
77 		tt_common_entry_tmp = tt_common_entry;
78 		break;
79 	}
80 	rcu_read_unlock();
81 
82 	return tt_common_entry_tmp;
83 }
84 
85 static struct batadv_tt_local_entry *
86 batadv_tt_local_hash_find(struct batadv_priv *bat_priv, const void *data)
87 {
88 	struct batadv_tt_common_entry *tt_common_entry;
89 	struct batadv_tt_local_entry *tt_local_entry = NULL;
90 
91 	tt_common_entry = batadv_tt_hash_find(bat_priv->tt.local_hash, data);
92 	if (tt_common_entry)
93 		tt_local_entry = container_of(tt_common_entry,
94 					      struct batadv_tt_local_entry,
95 					      common);
96 	return tt_local_entry;
97 }
98 
99 static struct batadv_tt_global_entry *
100 batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const void *data)
101 {
102 	struct batadv_tt_common_entry *tt_common_entry;
103 	struct batadv_tt_global_entry *tt_global_entry = NULL;
104 
105 	tt_common_entry = batadv_tt_hash_find(bat_priv->tt.global_hash, data);
106 	if (tt_common_entry)
107 		tt_global_entry = container_of(tt_common_entry,
108 					       struct batadv_tt_global_entry,
109 					       common);
110 	return tt_global_entry;
111 }
112 
113 static void
114 batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry)
115 {
116 	if (atomic_dec_and_test(&tt_local_entry->common.refcount))
117 		kfree_rcu(tt_local_entry, common.rcu);
118 }
119 
120 static void batadv_tt_global_entry_free_rcu(struct rcu_head *rcu)
121 {
122 	struct batadv_tt_common_entry *tt_common_entry;
123 	struct batadv_tt_global_entry *tt_global_entry;
124 
125 	tt_common_entry = container_of(rcu, struct batadv_tt_common_entry, rcu);
126 	tt_global_entry = container_of(tt_common_entry,
127 				       struct batadv_tt_global_entry, common);
128 
129 	kfree(tt_global_entry);
130 }
131 
132 static void
133 batadv_tt_global_entry_free_ref(struct batadv_tt_global_entry *tt_global_entry)
134 {
135 	if (atomic_dec_and_test(&tt_global_entry->common.refcount)) {
136 		batadv_tt_global_del_orig_list(tt_global_entry);
137 		call_rcu(&tt_global_entry->common.rcu,
138 			 batadv_tt_global_entry_free_rcu);
139 	}
140 }
141 
142 static void batadv_tt_orig_list_entry_free_rcu(struct rcu_head *rcu)
143 {
144 	struct batadv_tt_orig_list_entry *orig_entry;
145 
146 	orig_entry = container_of(rcu, struct batadv_tt_orig_list_entry, rcu);
147 	batadv_orig_node_free_ref(orig_entry->orig_node);
148 	kfree(orig_entry);
149 }
150 
151 static void
152 batadv_tt_orig_list_entry_free_ref(struct batadv_tt_orig_list_entry *orig_entry)
153 {
154 	if (!atomic_dec_and_test(&orig_entry->refcount))
155 		return;
156 	/* to avoid race conditions, immediately decrease the tt counter */
157 	atomic_dec(&orig_entry->orig_node->tt_size);
158 	call_rcu(&orig_entry->rcu, batadv_tt_orig_list_entry_free_rcu);
159 }
160 
161 static void batadv_tt_local_event(struct batadv_priv *bat_priv,
162 				  const uint8_t *addr, uint8_t flags)
163 {
164 	struct batadv_tt_change_node *tt_change_node, *entry, *safe;
165 	bool event_removed = false;
166 	bool del_op_requested, del_op_entry;
167 
168 	tt_change_node = kmalloc(sizeof(*tt_change_node), GFP_ATOMIC);
169 
170 	if (!tt_change_node)
171 		return;
172 
173 	tt_change_node->change.flags = flags;
174 	memcpy(tt_change_node->change.addr, addr, ETH_ALEN);
175 
176 	del_op_requested = flags & BATADV_TT_CLIENT_DEL;
177 
178 	/* check for ADD+DEL or DEL+ADD events */
179 	spin_lock_bh(&bat_priv->tt.changes_list_lock);
180 	list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
181 				 list) {
182 		if (!batadv_compare_eth(entry->change.addr, addr))
183 			continue;
184 
185 		/* DEL+ADD in the same orig interval have no effect and can be
186 		 * removed to avoid silly behaviour on the receiver side. The
187 		 * other way around (ADD+DEL) can happen in case of roaming of
188 		 * a client still in the NEW state. Roaming of NEW clients is
189 		 * now possible due to automatically recognition of "temporary"
190 		 * clients
191 		 */
192 		del_op_entry = entry->change.flags & BATADV_TT_CLIENT_DEL;
193 		if (!del_op_requested && del_op_entry)
194 			goto del;
195 		if (del_op_requested && !del_op_entry)
196 			goto del;
197 		continue;
198 del:
199 		list_del(&entry->list);
200 		kfree(entry);
201 		kfree(tt_change_node);
202 		event_removed = true;
203 		goto unlock;
204 	}
205 
206 	/* track the change in the OGMinterval list */
207 	list_add_tail(&tt_change_node->list, &bat_priv->tt.changes_list);
208 
209 unlock:
210 	spin_unlock_bh(&bat_priv->tt.changes_list_lock);
211 
212 	if (event_removed)
213 		atomic_dec(&bat_priv->tt.local_changes);
214 	else
215 		atomic_inc(&bat_priv->tt.local_changes);
216 }
217 
218 int batadv_tt_len(int changes_num)
219 {
220 	return changes_num * sizeof(struct batadv_tt_change);
221 }
222 
223 static int batadv_tt_local_init(struct batadv_priv *bat_priv)
224 {
225 	if (bat_priv->tt.local_hash)
226 		return 0;
227 
228 	bat_priv->tt.local_hash = batadv_hash_new(1024);
229 
230 	if (!bat_priv->tt.local_hash)
231 		return -ENOMEM;
232 
233 	batadv_hash_set_lock_class(bat_priv->tt.local_hash,
234 				   &batadv_tt_local_hash_lock_class_key);
235 
236 	return 0;
237 }
238 
239 static void batadv_tt_global_free(struct batadv_priv *bat_priv,
240 				  struct batadv_tt_global_entry *tt_global,
241 				  const char *message)
242 {
243 	batadv_dbg(BATADV_DBG_TT, bat_priv,
244 		   "Deleting global tt entry %pM: %s\n",
245 		   tt_global->common.addr, message);
246 
247 	batadv_hash_remove(bat_priv->tt.global_hash, batadv_compare_tt,
248 			   batadv_choose_orig, tt_global->common.addr);
249 	batadv_tt_global_entry_free_ref(tt_global);
250 }
251 
252 void batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,
253 			 int ifindex)
254 {
255 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
256 	struct batadv_tt_local_entry *tt_local;
257 	struct batadv_tt_global_entry *tt_global;
258 	struct hlist_head *head;
259 	struct batadv_tt_orig_list_entry *orig_entry;
260 	int hash_added;
261 	bool roamed_back = false;
262 
263 	tt_local = batadv_tt_local_hash_find(bat_priv, addr);
264 	tt_global = batadv_tt_global_hash_find(bat_priv, addr);
265 
266 	if (tt_local) {
267 		tt_local->last_seen = jiffies;
268 		if (tt_local->common.flags & BATADV_TT_CLIENT_PENDING) {
269 			batadv_dbg(BATADV_DBG_TT, bat_priv,
270 				   "Re-adding pending client %pM\n", addr);
271 			/* whatever the reason why the PENDING flag was set,
272 			 * this is a client which was enqueued to be removed in
273 			 * this orig_interval. Since it popped up again, the
274 			 * flag can be reset like it was never enqueued
275 			 */
276 			tt_local->common.flags &= ~BATADV_TT_CLIENT_PENDING;
277 			goto add_event;
278 		}
279 
280 		if (tt_local->common.flags & BATADV_TT_CLIENT_ROAM) {
281 			batadv_dbg(BATADV_DBG_TT, bat_priv,
282 				   "Roaming client %pM came back to its original location\n",
283 				   addr);
284 			/* the ROAM flag is set because this client roamed away
285 			 * and the node got a roaming_advertisement message. Now
286 			 * that the client popped up again at its original
287 			 * location such flag can be unset
288 			 */
289 			tt_local->common.flags &= ~BATADV_TT_CLIENT_ROAM;
290 			roamed_back = true;
291 		}
292 		goto check_roaming;
293 	}
294 
295 	tt_local = kmalloc(sizeof(*tt_local), GFP_ATOMIC);
296 	if (!tt_local)
297 		goto out;
298 
299 	batadv_dbg(BATADV_DBG_TT, bat_priv,
300 		   "Creating new local tt entry: %pM (ttvn: %d)\n", addr,
301 		   (uint8_t)atomic_read(&bat_priv->tt.vn));
302 
303 	memcpy(tt_local->common.addr, addr, ETH_ALEN);
304 	/* The local entry has to be marked as NEW to avoid to send it in
305 	 * a full table response going out before the next ttvn increment
306 	 * (consistency check)
307 	 */
308 	tt_local->common.flags = BATADV_TT_CLIENT_NEW;
309 	if (batadv_is_wifi_iface(ifindex))
310 		tt_local->common.flags |= BATADV_TT_CLIENT_WIFI;
311 	atomic_set(&tt_local->common.refcount, 2);
312 	tt_local->last_seen = jiffies;
313 	tt_local->common.added_at = tt_local->last_seen;
314 
315 	/* the batman interface mac address should never be purged */
316 	if (batadv_compare_eth(addr, soft_iface->dev_addr))
317 		tt_local->common.flags |= BATADV_TT_CLIENT_NOPURGE;
318 
319 	hash_added = batadv_hash_add(bat_priv->tt.local_hash, batadv_compare_tt,
320 				     batadv_choose_orig, &tt_local->common,
321 				     &tt_local->common.hash_entry);
322 
323 	if (unlikely(hash_added != 0)) {
324 		/* remove the reference for the hash */
325 		batadv_tt_local_entry_free_ref(tt_local);
326 		goto out;
327 	}
328 
329 add_event:
330 	batadv_tt_local_event(bat_priv, addr, tt_local->common.flags);
331 
332 check_roaming:
333 	/* Check whether it is a roaming, but don't do anything if the roaming
334 	 * process has already been handled
335 	 */
336 	if (tt_global && !(tt_global->common.flags & BATADV_TT_CLIENT_ROAM)) {
337 		/* These node are probably going to update their tt table */
338 		head = &tt_global->orig_list;
339 		rcu_read_lock();
340 		hlist_for_each_entry_rcu(orig_entry, head, list) {
341 			batadv_send_roam_adv(bat_priv, tt_global->common.addr,
342 					     orig_entry->orig_node);
343 		}
344 		rcu_read_unlock();
345 		if (roamed_back) {
346 			batadv_tt_global_free(bat_priv, tt_global,
347 					      "Roaming canceled");
348 			tt_global = NULL;
349 		} else {
350 			/* The global entry has to be marked as ROAMING and
351 			 * has to be kept for consistency purpose
352 			 */
353 			tt_global->common.flags |= BATADV_TT_CLIENT_ROAM;
354 			tt_global->roam_at = jiffies;
355 		}
356 	}
357 
358 out:
359 	if (tt_local)
360 		batadv_tt_local_entry_free_ref(tt_local);
361 	if (tt_global)
362 		batadv_tt_global_entry_free_ref(tt_global);
363 }
364 
365 static void batadv_tt_realloc_packet_buff(unsigned char **packet_buff,
366 					  int *packet_buff_len,
367 					  int min_packet_len,
368 					  int new_packet_len)
369 {
370 	unsigned char *new_buff;
371 
372 	new_buff = kmalloc(new_packet_len, GFP_ATOMIC);
373 
374 	/* keep old buffer if kmalloc should fail */
375 	if (new_buff) {
376 		memcpy(new_buff, *packet_buff, min_packet_len);
377 		kfree(*packet_buff);
378 		*packet_buff = new_buff;
379 		*packet_buff_len = new_packet_len;
380 	}
381 }
382 
383 static void batadv_tt_prepare_packet_buff(struct batadv_priv *bat_priv,
384 					  unsigned char **packet_buff,
385 					  int *packet_buff_len,
386 					  int min_packet_len)
387 {
388 	int req_len;
389 
390 	req_len = min_packet_len;
391 	req_len += batadv_tt_len(atomic_read(&bat_priv->tt.local_changes));
392 
393 	/* if we have too many changes for one packet don't send any
394 	 * and wait for the tt table request which will be fragmented
395 	 */
396 	if (req_len > bat_priv->soft_iface->mtu)
397 		req_len = min_packet_len;
398 
399 	batadv_tt_realloc_packet_buff(packet_buff, packet_buff_len,
400 				      min_packet_len, req_len);
401 }
402 
403 static int batadv_tt_changes_fill_buff(struct batadv_priv *bat_priv,
404 				       unsigned char **packet_buff,
405 				       int *packet_buff_len,
406 				       int min_packet_len)
407 {
408 	struct batadv_tt_change_node *entry, *safe;
409 	int count = 0, tot_changes = 0, new_len;
410 	unsigned char *tt_buff;
411 
412 	batadv_tt_prepare_packet_buff(bat_priv, packet_buff,
413 				      packet_buff_len, min_packet_len);
414 
415 	new_len = *packet_buff_len - min_packet_len;
416 	tt_buff = *packet_buff + min_packet_len;
417 
418 	if (new_len > 0)
419 		tot_changes = new_len / batadv_tt_len(1);
420 
421 	spin_lock_bh(&bat_priv->tt.changes_list_lock);
422 	atomic_set(&bat_priv->tt.local_changes, 0);
423 
424 	list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
425 				 list) {
426 		if (count < tot_changes) {
427 			memcpy(tt_buff + batadv_tt_len(count),
428 			       &entry->change, sizeof(struct batadv_tt_change));
429 			count++;
430 		}
431 		list_del(&entry->list);
432 		kfree(entry);
433 	}
434 	spin_unlock_bh(&bat_priv->tt.changes_list_lock);
435 
436 	/* Keep the buffer for possible tt_request */
437 	spin_lock_bh(&bat_priv->tt.last_changeset_lock);
438 	kfree(bat_priv->tt.last_changeset);
439 	bat_priv->tt.last_changeset_len = 0;
440 	bat_priv->tt.last_changeset = NULL;
441 	/* check whether this new OGM has no changes due to size problems */
442 	if (new_len > 0) {
443 		/* if kmalloc() fails we will reply with the full table
444 		 * instead of providing the diff
445 		 */
446 		bat_priv->tt.last_changeset = kmalloc(new_len, GFP_ATOMIC);
447 		if (bat_priv->tt.last_changeset) {
448 			memcpy(bat_priv->tt.last_changeset, tt_buff, new_len);
449 			bat_priv->tt.last_changeset_len = new_len;
450 		}
451 	}
452 	spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
453 
454 	return count;
455 }
456 
457 int batadv_tt_local_seq_print_text(struct seq_file *seq, void *offset)
458 {
459 	struct net_device *net_dev = (struct net_device *)seq->private;
460 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
461 	struct batadv_hashtable *hash = bat_priv->tt.local_hash;
462 	struct batadv_tt_common_entry *tt_common_entry;
463 	struct batadv_tt_local_entry *tt_local;
464 	struct batadv_hard_iface *primary_if;
465 	struct hlist_head *head;
466 	uint32_t i;
467 	int last_seen_secs;
468 	int last_seen_msecs;
469 	unsigned long last_seen_jiffies;
470 	bool no_purge;
471 	uint16_t np_flag = BATADV_TT_CLIENT_NOPURGE;
472 
473 	primary_if = batadv_seq_print_text_primary_if_get(seq);
474 	if (!primary_if)
475 		goto out;
476 
477 	seq_printf(seq,
478 		   "Locally retrieved addresses (from %s) announced via TT (TTVN: %u CRC: %#.4x):\n",
479 		   net_dev->name, (uint8_t)atomic_read(&bat_priv->tt.vn),
480 		   bat_priv->tt.local_crc);
481 	seq_printf(seq, "       %-13s %-7s %-10s\n", "Client", "Flags",
482 		   "Last seen");
483 
484 	for (i = 0; i < hash->size; i++) {
485 		head = &hash->table[i];
486 
487 		rcu_read_lock();
488 		hlist_for_each_entry_rcu(tt_common_entry,
489 					 head, hash_entry) {
490 			tt_local = container_of(tt_common_entry,
491 						struct batadv_tt_local_entry,
492 						common);
493 			last_seen_jiffies = jiffies - tt_local->last_seen;
494 			last_seen_msecs = jiffies_to_msecs(last_seen_jiffies);
495 			last_seen_secs = last_seen_msecs / 1000;
496 			last_seen_msecs = last_seen_msecs % 1000;
497 
498 			no_purge = tt_common_entry->flags & np_flag;
499 
500 			seq_printf(seq, " * %pM [%c%c%c%c%c] %3u.%03u\n",
501 				   tt_common_entry->addr,
502 				   (tt_common_entry->flags &
503 				    BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
504 				   no_purge ? 'P' : '.',
505 				   (tt_common_entry->flags &
506 				    BATADV_TT_CLIENT_NEW ? 'N' : '.'),
507 				   (tt_common_entry->flags &
508 				    BATADV_TT_CLIENT_PENDING ? 'X' : '.'),
509 				   (tt_common_entry->flags &
510 				    BATADV_TT_CLIENT_WIFI ? 'W' : '.'),
511 				   no_purge ? 0 : last_seen_secs,
512 				   no_purge ? 0 : last_seen_msecs);
513 		}
514 		rcu_read_unlock();
515 	}
516 out:
517 	if (primary_if)
518 		batadv_hardif_free_ref(primary_if);
519 	return 0;
520 }
521 
522 static void
523 batadv_tt_local_set_pending(struct batadv_priv *bat_priv,
524 			    struct batadv_tt_local_entry *tt_local_entry,
525 			    uint16_t flags, const char *message)
526 {
527 	batadv_tt_local_event(bat_priv, tt_local_entry->common.addr,
528 			      tt_local_entry->common.flags | flags);
529 
530 	/* The local client has to be marked as "pending to be removed" but has
531 	 * to be kept in the table in order to send it in a full table
532 	 * response issued before the net ttvn increment (consistency check)
533 	 */
534 	tt_local_entry->common.flags |= BATADV_TT_CLIENT_PENDING;
535 
536 	batadv_dbg(BATADV_DBG_TT, bat_priv,
537 		   "Local tt entry (%pM) pending to be removed: %s\n",
538 		   tt_local_entry->common.addr, message);
539 }
540 
541 /**
542  * batadv_tt_local_remove - logically remove an entry from the local table
543  * @bat_priv: the bat priv with all the soft interface information
544  * @addr: the MAC address of the client to remove
545  * @message: message to append to the log on deletion
546  * @roaming: true if the deletion is due to a roaming event
547  *
548  * Returns the flags assigned to the local entry before being deleted
549  */
550 uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
551 				const uint8_t *addr, const char *message,
552 				bool roaming)
553 {
554 	struct batadv_tt_local_entry *tt_local_entry;
555 	uint16_t flags, curr_flags = BATADV_NO_FLAGS;
556 
557 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
558 	if (!tt_local_entry)
559 		goto out;
560 
561 	curr_flags = tt_local_entry->common.flags;
562 
563 	flags = BATADV_TT_CLIENT_DEL;
564 	/* if this global entry addition is due to a roaming, the node has to
565 	 * mark the local entry as "roamed" in order to correctly reroute
566 	 * packets later
567 	 */
568 	if (roaming) {
569 		flags |= BATADV_TT_CLIENT_ROAM;
570 		/* mark the local client as ROAMed */
571 		tt_local_entry->common.flags |= BATADV_TT_CLIENT_ROAM;
572 	}
573 
574 	if (!(tt_local_entry->common.flags & BATADV_TT_CLIENT_NEW)) {
575 		batadv_tt_local_set_pending(bat_priv, tt_local_entry, flags,
576 					    message);
577 		goto out;
578 	}
579 	/* if this client has been added right now, it is possible to
580 	 * immediately purge it
581 	 */
582 	batadv_tt_local_event(bat_priv, tt_local_entry->common.addr,
583 			      curr_flags | BATADV_TT_CLIENT_DEL);
584 	hlist_del_rcu(&tt_local_entry->common.hash_entry);
585 	batadv_tt_local_entry_free_ref(tt_local_entry);
586 
587 out:
588 	if (tt_local_entry)
589 		batadv_tt_local_entry_free_ref(tt_local_entry);
590 
591 	return curr_flags;
592 }
593 
594 static void batadv_tt_local_purge_list(struct batadv_priv *bat_priv,
595 				       struct hlist_head *head)
596 {
597 	struct batadv_tt_local_entry *tt_local_entry;
598 	struct batadv_tt_common_entry *tt_common_entry;
599 	struct hlist_node *node_tmp;
600 
601 	hlist_for_each_entry_safe(tt_common_entry, node_tmp, head,
602 				  hash_entry) {
603 		tt_local_entry = container_of(tt_common_entry,
604 					      struct batadv_tt_local_entry,
605 					      common);
606 		if (tt_local_entry->common.flags & BATADV_TT_CLIENT_NOPURGE)
607 			continue;
608 
609 		/* entry already marked for deletion */
610 		if (tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING)
611 			continue;
612 
613 		if (!batadv_has_timed_out(tt_local_entry->last_seen,
614 					  BATADV_TT_LOCAL_TIMEOUT))
615 			continue;
616 
617 		batadv_tt_local_set_pending(bat_priv, tt_local_entry,
618 					    BATADV_TT_CLIENT_DEL, "timed out");
619 	}
620 }
621 
622 static void batadv_tt_local_purge(struct batadv_priv *bat_priv)
623 {
624 	struct batadv_hashtable *hash = bat_priv->tt.local_hash;
625 	struct hlist_head *head;
626 	spinlock_t *list_lock; /* protects write access to the hash lists */
627 	uint32_t i;
628 
629 	for (i = 0; i < hash->size; i++) {
630 		head = &hash->table[i];
631 		list_lock = &hash->list_locks[i];
632 
633 		spin_lock_bh(list_lock);
634 		batadv_tt_local_purge_list(bat_priv, head);
635 		spin_unlock_bh(list_lock);
636 	}
637 }
638 
639 static void batadv_tt_local_table_free(struct batadv_priv *bat_priv)
640 {
641 	struct batadv_hashtable *hash;
642 	spinlock_t *list_lock; /* protects write access to the hash lists */
643 	struct batadv_tt_common_entry *tt_common_entry;
644 	struct batadv_tt_local_entry *tt_local;
645 	struct hlist_node *node_tmp;
646 	struct hlist_head *head;
647 	uint32_t i;
648 
649 	if (!bat_priv->tt.local_hash)
650 		return;
651 
652 	hash = bat_priv->tt.local_hash;
653 
654 	for (i = 0; i < hash->size; i++) {
655 		head = &hash->table[i];
656 		list_lock = &hash->list_locks[i];
657 
658 		spin_lock_bh(list_lock);
659 		hlist_for_each_entry_safe(tt_common_entry, node_tmp,
660 					  head, hash_entry) {
661 			hlist_del_rcu(&tt_common_entry->hash_entry);
662 			tt_local = container_of(tt_common_entry,
663 						struct batadv_tt_local_entry,
664 						common);
665 			batadv_tt_local_entry_free_ref(tt_local);
666 		}
667 		spin_unlock_bh(list_lock);
668 	}
669 
670 	batadv_hash_destroy(hash);
671 
672 	bat_priv->tt.local_hash = NULL;
673 }
674 
675 static int batadv_tt_global_init(struct batadv_priv *bat_priv)
676 {
677 	if (bat_priv->tt.global_hash)
678 		return 0;
679 
680 	bat_priv->tt.global_hash = batadv_hash_new(1024);
681 
682 	if (!bat_priv->tt.global_hash)
683 		return -ENOMEM;
684 
685 	batadv_hash_set_lock_class(bat_priv->tt.global_hash,
686 				   &batadv_tt_global_hash_lock_class_key);
687 
688 	return 0;
689 }
690 
691 static void batadv_tt_changes_list_free(struct batadv_priv *bat_priv)
692 {
693 	struct batadv_tt_change_node *entry, *safe;
694 
695 	spin_lock_bh(&bat_priv->tt.changes_list_lock);
696 
697 	list_for_each_entry_safe(entry, safe, &bat_priv->tt.changes_list,
698 				 list) {
699 		list_del(&entry->list);
700 		kfree(entry);
701 	}
702 
703 	atomic_set(&bat_priv->tt.local_changes, 0);
704 	spin_unlock_bh(&bat_priv->tt.changes_list_lock);
705 }
706 
707 /* retrieves the orig_tt_list_entry belonging to orig_node from the
708  * batadv_tt_global_entry list
709  *
710  * returns it with an increased refcounter, NULL if not found
711  */
712 static struct batadv_tt_orig_list_entry *
713 batadv_tt_global_orig_entry_find(const struct batadv_tt_global_entry *entry,
714 				 const struct batadv_orig_node *orig_node)
715 {
716 	struct batadv_tt_orig_list_entry *tmp_orig_entry, *orig_entry = NULL;
717 	const struct hlist_head *head;
718 
719 	rcu_read_lock();
720 	head = &entry->orig_list;
721 	hlist_for_each_entry_rcu(tmp_orig_entry, head, list) {
722 		if (tmp_orig_entry->orig_node != orig_node)
723 			continue;
724 		if (!atomic_inc_not_zero(&tmp_orig_entry->refcount))
725 			continue;
726 
727 		orig_entry = tmp_orig_entry;
728 		break;
729 	}
730 	rcu_read_unlock();
731 
732 	return orig_entry;
733 }
734 
735 /* find out if an orig_node is already in the list of a tt_global_entry.
736  * returns true if found, false otherwise
737  */
738 static bool
739 batadv_tt_global_entry_has_orig(const struct batadv_tt_global_entry *entry,
740 				const struct batadv_orig_node *orig_node)
741 {
742 	struct batadv_tt_orig_list_entry *orig_entry;
743 	bool found = false;
744 
745 	orig_entry = batadv_tt_global_orig_entry_find(entry, orig_node);
746 	if (orig_entry) {
747 		found = true;
748 		batadv_tt_orig_list_entry_free_ref(orig_entry);
749 	}
750 
751 	return found;
752 }
753 
754 static void
755 batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
756 				struct batadv_orig_node *orig_node, int ttvn)
757 {
758 	struct batadv_tt_orig_list_entry *orig_entry;
759 
760 	orig_entry = batadv_tt_global_orig_entry_find(tt_global, orig_node);
761 	if (orig_entry) {
762 		/* refresh the ttvn: the current value could be a bogus one that
763 		 * was added during a "temporary client detection"
764 		 */
765 		orig_entry->ttvn = ttvn;
766 		goto out;
767 	}
768 
769 	orig_entry = kzalloc(sizeof(*orig_entry), GFP_ATOMIC);
770 	if (!orig_entry)
771 		goto out;
772 
773 	INIT_HLIST_NODE(&orig_entry->list);
774 	atomic_inc(&orig_node->refcount);
775 	atomic_inc(&orig_node->tt_size);
776 	orig_entry->orig_node = orig_node;
777 	orig_entry->ttvn = ttvn;
778 	atomic_set(&orig_entry->refcount, 2);
779 
780 	spin_lock_bh(&tt_global->list_lock);
781 	hlist_add_head_rcu(&orig_entry->list,
782 			   &tt_global->orig_list);
783 	spin_unlock_bh(&tt_global->list_lock);
784 out:
785 	if (orig_entry)
786 		batadv_tt_orig_list_entry_free_ref(orig_entry);
787 }
788 
789 /* caller must hold orig_node refcount */
790 int batadv_tt_global_add(struct batadv_priv *bat_priv,
791 			 struct batadv_orig_node *orig_node,
792 			 const unsigned char *tt_addr, uint8_t flags,
793 			 uint8_t ttvn)
794 {
795 	struct batadv_tt_global_entry *tt_global_entry;
796 	struct batadv_tt_local_entry *tt_local_entry;
797 	int ret = 0;
798 	int hash_added;
799 	struct batadv_tt_common_entry *common;
800 	uint16_t local_flags;
801 
802 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, tt_addr);
803 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, tt_addr);
804 
805 	/* if the node already has a local client for this entry, it has to wait
806 	 * for a roaming advertisement instead of manually messing up the global
807 	 * table
808 	 */
809 	if ((flags & BATADV_TT_CLIENT_TEMP) && tt_local_entry &&
810 	    !(tt_local_entry->common.flags & BATADV_TT_CLIENT_NEW))
811 		goto out;
812 
813 	if (!tt_global_entry) {
814 		tt_global_entry = kzalloc(sizeof(*tt_global_entry), GFP_ATOMIC);
815 		if (!tt_global_entry)
816 			goto out;
817 
818 		common = &tt_global_entry->common;
819 		memcpy(common->addr, tt_addr, ETH_ALEN);
820 
821 		common->flags = flags;
822 		tt_global_entry->roam_at = 0;
823 		/* node must store current time in case of roaming. This is
824 		 * needed to purge this entry out on timeout (if nobody claims
825 		 * it)
826 		 */
827 		if (flags & BATADV_TT_CLIENT_ROAM)
828 			tt_global_entry->roam_at = jiffies;
829 		atomic_set(&common->refcount, 2);
830 		common->added_at = jiffies;
831 
832 		INIT_HLIST_HEAD(&tt_global_entry->orig_list);
833 		spin_lock_init(&tt_global_entry->list_lock);
834 
835 		hash_added = batadv_hash_add(bat_priv->tt.global_hash,
836 					     batadv_compare_tt,
837 					     batadv_choose_orig, common,
838 					     &common->hash_entry);
839 
840 		if (unlikely(hash_added != 0)) {
841 			/* remove the reference for the hash */
842 			batadv_tt_global_entry_free_ref(tt_global_entry);
843 			goto out_remove;
844 		}
845 	} else {
846 		common = &tt_global_entry->common;
847 		/* If there is already a global entry, we can use this one for
848 		 * our processing.
849 		 * But if we are trying to add a temporary client then here are
850 		 * two options at this point:
851 		 * 1) the global client is not a temporary client: the global
852 		 *    client has to be left as it is, temporary information
853 		 *    should never override any already known client state
854 		 * 2) the global client is a temporary client: purge the
855 		 *    originator list and add the new one orig_entry
856 		 */
857 		if (flags & BATADV_TT_CLIENT_TEMP) {
858 			if (!(common->flags & BATADV_TT_CLIENT_TEMP))
859 				goto out;
860 			if (batadv_tt_global_entry_has_orig(tt_global_entry,
861 							    orig_node))
862 				goto out_remove;
863 			batadv_tt_global_del_orig_list(tt_global_entry);
864 			goto add_orig_entry;
865 		}
866 
867 		/* if the client was temporary added before receiving the first
868 		 * OGM announcing it, we have to clear the TEMP flag
869 		 */
870 		common->flags &= ~BATADV_TT_CLIENT_TEMP;
871 
872 		/* the change can carry possible "attribute" flags like the
873 		 * TT_CLIENT_WIFI, therefore they have to be copied in the
874 		 * client entry
875 		 */
876 		tt_global_entry->common.flags |= flags;
877 
878 		/* If there is the BATADV_TT_CLIENT_ROAM flag set, there is only
879 		 * one originator left in the list and we previously received a
880 		 * delete + roaming change for this originator.
881 		 *
882 		 * We should first delete the old originator before adding the
883 		 * new one.
884 		 */
885 		if (common->flags & BATADV_TT_CLIENT_ROAM) {
886 			batadv_tt_global_del_orig_list(tt_global_entry);
887 			common->flags &= ~BATADV_TT_CLIENT_ROAM;
888 			tt_global_entry->roam_at = 0;
889 		}
890 	}
891 add_orig_entry:
892 	/* add the new orig_entry (if needed) or update it */
893 	batadv_tt_global_orig_entry_add(tt_global_entry, orig_node, ttvn);
894 
895 	batadv_dbg(BATADV_DBG_TT, bat_priv,
896 		   "Creating new global tt entry: %pM (via %pM)\n",
897 		   common->addr, orig_node->orig);
898 	ret = 1;
899 
900 out_remove:
901 
902 	/* remove address from local hash if present */
903 	local_flags = batadv_tt_local_remove(bat_priv, tt_addr,
904 					     "global tt received",
905 					     flags & BATADV_TT_CLIENT_ROAM);
906 	tt_global_entry->common.flags |= local_flags & BATADV_TT_CLIENT_WIFI;
907 
908 	if (!(flags & BATADV_TT_CLIENT_ROAM))
909 		/* this is a normal global add. Therefore the client is not in a
910 		 * roaming state anymore.
911 		 */
912 		tt_global_entry->common.flags &= ~BATADV_TT_CLIENT_ROAM;
913 
914 out:
915 	if (tt_global_entry)
916 		batadv_tt_global_entry_free_ref(tt_global_entry);
917 	if (tt_local_entry)
918 		batadv_tt_local_entry_free_ref(tt_local_entry);
919 	return ret;
920 }
921 
922 /* batadv_transtable_best_orig - Get best originator list entry from tt entry
923  * @tt_global_entry: global translation table entry to be analyzed
924  *
925  * This functon assumes the caller holds rcu_read_lock().
926  * Returns best originator list entry or NULL on errors.
927  */
928 static struct batadv_tt_orig_list_entry *
929 batadv_transtable_best_orig(struct batadv_tt_global_entry *tt_global_entry)
930 {
931 	struct batadv_neigh_node *router = NULL;
932 	struct hlist_head *head;
933 	struct batadv_tt_orig_list_entry *orig_entry, *best_entry = NULL;
934 	int best_tq = 0;
935 
936 	head = &tt_global_entry->orig_list;
937 	hlist_for_each_entry_rcu(orig_entry, head, list) {
938 		router = batadv_orig_node_get_router(orig_entry->orig_node);
939 		if (!router)
940 			continue;
941 
942 		if (router->tq_avg > best_tq) {
943 			best_entry = orig_entry;
944 			best_tq = router->tq_avg;
945 		}
946 
947 		batadv_neigh_node_free_ref(router);
948 	}
949 
950 	return best_entry;
951 }
952 
953 /* batadv_tt_global_print_entry - print all orig nodes who announce the address
954  * for this global entry
955  * @tt_global_entry: global translation table entry to be printed
956  * @seq: debugfs table seq_file struct
957  *
958  * This functon assumes the caller holds rcu_read_lock().
959  */
960 static void
961 batadv_tt_global_print_entry(struct batadv_tt_global_entry *tt_global_entry,
962 			     struct seq_file *seq)
963 {
964 	struct hlist_head *head;
965 	struct batadv_tt_orig_list_entry *orig_entry, *best_entry;
966 	struct batadv_tt_common_entry *tt_common_entry;
967 	uint16_t flags;
968 	uint8_t last_ttvn;
969 
970 	tt_common_entry = &tt_global_entry->common;
971 	flags = tt_common_entry->flags;
972 
973 	best_entry = batadv_transtable_best_orig(tt_global_entry);
974 	if (best_entry) {
975 		last_ttvn = atomic_read(&best_entry->orig_node->last_ttvn);
976 		seq_printf(seq,
977 			   " %c %pM  (%3u) via %pM     (%3u)   (%#.4x) [%c%c%c]\n",
978 			   '*', tt_global_entry->common.addr,
979 			   best_entry->ttvn, best_entry->orig_node->orig,
980 			   last_ttvn, best_entry->orig_node->tt_crc,
981 			   (flags & BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
982 			   (flags & BATADV_TT_CLIENT_WIFI ? 'W' : '.'),
983 			   (flags & BATADV_TT_CLIENT_TEMP ? 'T' : '.'));
984 	}
985 
986 	head = &tt_global_entry->orig_list;
987 
988 	hlist_for_each_entry_rcu(orig_entry, head, list) {
989 		if (best_entry == orig_entry)
990 			continue;
991 
992 		last_ttvn = atomic_read(&orig_entry->orig_node->last_ttvn);
993 		seq_printf(seq,	" %c %pM  (%3u) via %pM     (%3u)   [%c%c%c]\n",
994 			   '+', tt_global_entry->common.addr,
995 			   orig_entry->ttvn, orig_entry->orig_node->orig,
996 			   last_ttvn,
997 			   (flags & BATADV_TT_CLIENT_ROAM ? 'R' : '.'),
998 			   (flags & BATADV_TT_CLIENT_WIFI ? 'W' : '.'),
999 			   (flags & BATADV_TT_CLIENT_TEMP ? 'T' : '.'));
1000 	}
1001 }
1002 
1003 int batadv_tt_global_seq_print_text(struct seq_file *seq, void *offset)
1004 {
1005 	struct net_device *net_dev = (struct net_device *)seq->private;
1006 	struct batadv_priv *bat_priv = netdev_priv(net_dev);
1007 	struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1008 	struct batadv_tt_common_entry *tt_common_entry;
1009 	struct batadv_tt_global_entry *tt_global;
1010 	struct batadv_hard_iface *primary_if;
1011 	struct hlist_head *head;
1012 	uint32_t i;
1013 
1014 	primary_if = batadv_seq_print_text_primary_if_get(seq);
1015 	if (!primary_if)
1016 		goto out;
1017 
1018 	seq_printf(seq,
1019 		   "Globally announced TT entries received via the mesh %s\n",
1020 		   net_dev->name);
1021 	seq_printf(seq, "       %-13s %s       %-15s %s (%-6s) %s\n",
1022 		   "Client", "(TTVN)", "Originator", "(Curr TTVN)", "CRC",
1023 		   "Flags");
1024 
1025 	for (i = 0; i < hash->size; i++) {
1026 		head = &hash->table[i];
1027 
1028 		rcu_read_lock();
1029 		hlist_for_each_entry_rcu(tt_common_entry,
1030 					 head, hash_entry) {
1031 			tt_global = container_of(tt_common_entry,
1032 						 struct batadv_tt_global_entry,
1033 						 common);
1034 			batadv_tt_global_print_entry(tt_global, seq);
1035 		}
1036 		rcu_read_unlock();
1037 	}
1038 out:
1039 	if (primary_if)
1040 		batadv_hardif_free_ref(primary_if);
1041 	return 0;
1042 }
1043 
1044 /* deletes the orig list of a tt_global_entry */
1045 static void
1046 batadv_tt_global_del_orig_list(struct batadv_tt_global_entry *tt_global_entry)
1047 {
1048 	struct hlist_head *head;
1049 	struct hlist_node *safe;
1050 	struct batadv_tt_orig_list_entry *orig_entry;
1051 
1052 	spin_lock_bh(&tt_global_entry->list_lock);
1053 	head = &tt_global_entry->orig_list;
1054 	hlist_for_each_entry_safe(orig_entry, safe, head, list) {
1055 		hlist_del_rcu(&orig_entry->list);
1056 		batadv_tt_orig_list_entry_free_ref(orig_entry);
1057 	}
1058 	spin_unlock_bh(&tt_global_entry->list_lock);
1059 }
1060 
1061 static void
1062 batadv_tt_global_del_orig_entry(struct batadv_priv *bat_priv,
1063 				struct batadv_tt_global_entry *tt_global_entry,
1064 				struct batadv_orig_node *orig_node,
1065 				const char *message)
1066 {
1067 	struct hlist_head *head;
1068 	struct hlist_node *safe;
1069 	struct batadv_tt_orig_list_entry *orig_entry;
1070 
1071 	spin_lock_bh(&tt_global_entry->list_lock);
1072 	head = &tt_global_entry->orig_list;
1073 	hlist_for_each_entry_safe(orig_entry, safe, head, list) {
1074 		if (orig_entry->orig_node == orig_node) {
1075 			batadv_dbg(BATADV_DBG_TT, bat_priv,
1076 				   "Deleting %pM from global tt entry %pM: %s\n",
1077 				   orig_node->orig,
1078 				   tt_global_entry->common.addr, message);
1079 			hlist_del_rcu(&orig_entry->list);
1080 			batadv_tt_orig_list_entry_free_ref(orig_entry);
1081 		}
1082 	}
1083 	spin_unlock_bh(&tt_global_entry->list_lock);
1084 }
1085 
1086 /* If the client is to be deleted, we check if it is the last origantor entry
1087  * within tt_global entry. If yes, we set the BATADV_TT_CLIENT_ROAM flag and the
1088  * timer, otherwise we simply remove the originator scheduled for deletion.
1089  */
1090 static void
1091 batadv_tt_global_del_roaming(struct batadv_priv *bat_priv,
1092 			     struct batadv_tt_global_entry *tt_global_entry,
1093 			     struct batadv_orig_node *orig_node,
1094 			     const char *message)
1095 {
1096 	bool last_entry = true;
1097 	struct hlist_head *head;
1098 	struct batadv_tt_orig_list_entry *orig_entry;
1099 
1100 	/* no local entry exists, case 1:
1101 	 * Check if this is the last one or if other entries exist.
1102 	 */
1103 
1104 	rcu_read_lock();
1105 	head = &tt_global_entry->orig_list;
1106 	hlist_for_each_entry_rcu(orig_entry, head, list) {
1107 		if (orig_entry->orig_node != orig_node) {
1108 			last_entry = false;
1109 			break;
1110 		}
1111 	}
1112 	rcu_read_unlock();
1113 
1114 	if (last_entry) {
1115 		/* its the last one, mark for roaming. */
1116 		tt_global_entry->common.flags |= BATADV_TT_CLIENT_ROAM;
1117 		tt_global_entry->roam_at = jiffies;
1118 	} else
1119 		/* there is another entry, we can simply delete this
1120 		 * one and can still use the other one.
1121 		 */
1122 		batadv_tt_global_del_orig_entry(bat_priv, tt_global_entry,
1123 						orig_node, message);
1124 }
1125 
1126 
1127 
1128 static void batadv_tt_global_del(struct batadv_priv *bat_priv,
1129 				 struct batadv_orig_node *orig_node,
1130 				 const unsigned char *addr,
1131 				 const char *message, bool roaming)
1132 {
1133 	struct batadv_tt_global_entry *tt_global_entry;
1134 	struct batadv_tt_local_entry *local_entry = NULL;
1135 
1136 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
1137 	if (!tt_global_entry)
1138 		goto out;
1139 
1140 	if (!roaming) {
1141 		batadv_tt_global_del_orig_entry(bat_priv, tt_global_entry,
1142 						orig_node, message);
1143 
1144 		if (hlist_empty(&tt_global_entry->orig_list))
1145 			batadv_tt_global_free(bat_priv, tt_global_entry,
1146 					      message);
1147 
1148 		goto out;
1149 	}
1150 
1151 	/* if we are deleting a global entry due to a roam
1152 	 * event, there are two possibilities:
1153 	 * 1) the client roamed from node A to node B => if there
1154 	 *    is only one originator left for this client, we mark
1155 	 *    it with BATADV_TT_CLIENT_ROAM, we start a timer and we
1156 	 *    wait for node B to claim it. In case of timeout
1157 	 *    the entry is purged.
1158 	 *
1159 	 *    If there are other originators left, we directly delete
1160 	 *    the originator.
1161 	 * 2) the client roamed to us => we can directly delete
1162 	 *    the global entry, since it is useless now.
1163 	 */
1164 	local_entry = batadv_tt_local_hash_find(bat_priv,
1165 						tt_global_entry->common.addr);
1166 	if (local_entry) {
1167 		/* local entry exists, case 2: client roamed to us. */
1168 		batadv_tt_global_del_orig_list(tt_global_entry);
1169 		batadv_tt_global_free(bat_priv, tt_global_entry, message);
1170 	} else
1171 		/* no local entry exists, case 1: check for roaming */
1172 		batadv_tt_global_del_roaming(bat_priv, tt_global_entry,
1173 					     orig_node, message);
1174 
1175 
1176 out:
1177 	if (tt_global_entry)
1178 		batadv_tt_global_entry_free_ref(tt_global_entry);
1179 	if (local_entry)
1180 		batadv_tt_local_entry_free_ref(local_entry);
1181 }
1182 
1183 void batadv_tt_global_del_orig(struct batadv_priv *bat_priv,
1184 			       struct batadv_orig_node *orig_node,
1185 			       const char *message)
1186 {
1187 	struct batadv_tt_global_entry *tt_global;
1188 	struct batadv_tt_common_entry *tt_common_entry;
1189 	uint32_t i;
1190 	struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1191 	struct hlist_node *safe;
1192 	struct hlist_head *head;
1193 	spinlock_t *list_lock; /* protects write access to the hash lists */
1194 
1195 	if (!hash)
1196 		return;
1197 
1198 	for (i = 0; i < hash->size; i++) {
1199 		head = &hash->table[i];
1200 		list_lock = &hash->list_locks[i];
1201 
1202 		spin_lock_bh(list_lock);
1203 		hlist_for_each_entry_safe(tt_common_entry, safe,
1204 					  head, hash_entry) {
1205 			tt_global = container_of(tt_common_entry,
1206 						 struct batadv_tt_global_entry,
1207 						 common);
1208 
1209 			batadv_tt_global_del_orig_entry(bat_priv, tt_global,
1210 							orig_node, message);
1211 
1212 			if (hlist_empty(&tt_global->orig_list)) {
1213 				batadv_dbg(BATADV_DBG_TT, bat_priv,
1214 					   "Deleting global tt entry %pM: %s\n",
1215 					   tt_global->common.addr, message);
1216 				hlist_del_rcu(&tt_common_entry->hash_entry);
1217 				batadv_tt_global_entry_free_ref(tt_global);
1218 			}
1219 		}
1220 		spin_unlock_bh(list_lock);
1221 	}
1222 	orig_node->tt_initialised = false;
1223 }
1224 
1225 static bool batadv_tt_global_to_purge(struct batadv_tt_global_entry *tt_global,
1226 				      char **msg)
1227 {
1228 	bool purge = false;
1229 	unsigned long roam_timeout = BATADV_TT_CLIENT_ROAM_TIMEOUT;
1230 	unsigned long temp_timeout = BATADV_TT_CLIENT_TEMP_TIMEOUT;
1231 
1232 	if ((tt_global->common.flags & BATADV_TT_CLIENT_ROAM) &&
1233 	    batadv_has_timed_out(tt_global->roam_at, roam_timeout)) {
1234 		purge = true;
1235 		*msg = "Roaming timeout\n";
1236 	}
1237 
1238 	if ((tt_global->common.flags & BATADV_TT_CLIENT_TEMP) &&
1239 	    batadv_has_timed_out(tt_global->common.added_at, temp_timeout)) {
1240 		purge = true;
1241 		*msg = "Temporary client timeout\n";
1242 	}
1243 
1244 	return purge;
1245 }
1246 
1247 static void batadv_tt_global_purge(struct batadv_priv *bat_priv)
1248 {
1249 	struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1250 	struct hlist_head *head;
1251 	struct hlist_node *node_tmp;
1252 	spinlock_t *list_lock; /* protects write access to the hash lists */
1253 	uint32_t i;
1254 	char *msg = NULL;
1255 	struct batadv_tt_common_entry *tt_common;
1256 	struct batadv_tt_global_entry *tt_global;
1257 
1258 	for (i = 0; i < hash->size; i++) {
1259 		head = &hash->table[i];
1260 		list_lock = &hash->list_locks[i];
1261 
1262 		spin_lock_bh(list_lock);
1263 		hlist_for_each_entry_safe(tt_common, node_tmp, head,
1264 					  hash_entry) {
1265 			tt_global = container_of(tt_common,
1266 						 struct batadv_tt_global_entry,
1267 						 common);
1268 
1269 			if (!batadv_tt_global_to_purge(tt_global, &msg))
1270 				continue;
1271 
1272 			batadv_dbg(BATADV_DBG_TT, bat_priv,
1273 				   "Deleting global tt entry (%pM): %s\n",
1274 				   tt_global->common.addr, msg);
1275 
1276 			hlist_del_rcu(&tt_common->hash_entry);
1277 
1278 			batadv_tt_global_entry_free_ref(tt_global);
1279 		}
1280 		spin_unlock_bh(list_lock);
1281 	}
1282 }
1283 
1284 static void batadv_tt_global_table_free(struct batadv_priv *bat_priv)
1285 {
1286 	struct batadv_hashtable *hash;
1287 	spinlock_t *list_lock; /* protects write access to the hash lists */
1288 	struct batadv_tt_common_entry *tt_common_entry;
1289 	struct batadv_tt_global_entry *tt_global;
1290 	struct hlist_node *node_tmp;
1291 	struct hlist_head *head;
1292 	uint32_t i;
1293 
1294 	if (!bat_priv->tt.global_hash)
1295 		return;
1296 
1297 	hash = bat_priv->tt.global_hash;
1298 
1299 	for (i = 0; i < hash->size; i++) {
1300 		head = &hash->table[i];
1301 		list_lock = &hash->list_locks[i];
1302 
1303 		spin_lock_bh(list_lock);
1304 		hlist_for_each_entry_safe(tt_common_entry, node_tmp,
1305 					  head, hash_entry) {
1306 			hlist_del_rcu(&tt_common_entry->hash_entry);
1307 			tt_global = container_of(tt_common_entry,
1308 						 struct batadv_tt_global_entry,
1309 						 common);
1310 			batadv_tt_global_entry_free_ref(tt_global);
1311 		}
1312 		spin_unlock_bh(list_lock);
1313 	}
1314 
1315 	batadv_hash_destroy(hash);
1316 
1317 	bat_priv->tt.global_hash = NULL;
1318 }
1319 
1320 static bool
1321 _batadv_is_ap_isolated(struct batadv_tt_local_entry *tt_local_entry,
1322 		       struct batadv_tt_global_entry *tt_global_entry)
1323 {
1324 	bool ret = false;
1325 
1326 	if (tt_local_entry->common.flags & BATADV_TT_CLIENT_WIFI &&
1327 	    tt_global_entry->common.flags & BATADV_TT_CLIENT_WIFI)
1328 		ret = true;
1329 
1330 	return ret;
1331 }
1332 
1333 struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
1334 						  const uint8_t *src,
1335 						  const uint8_t *addr)
1336 {
1337 	struct batadv_tt_local_entry *tt_local_entry = NULL;
1338 	struct batadv_tt_global_entry *tt_global_entry = NULL;
1339 	struct batadv_orig_node *orig_node = NULL;
1340 	struct batadv_tt_orig_list_entry *best_entry;
1341 
1342 	if (src && atomic_read(&bat_priv->ap_isolation)) {
1343 		tt_local_entry = batadv_tt_local_hash_find(bat_priv, src);
1344 		if (!tt_local_entry ||
1345 		    (tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING))
1346 			goto out;
1347 	}
1348 
1349 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
1350 	if (!tt_global_entry)
1351 		goto out;
1352 
1353 	/* check whether the clients should not communicate due to AP
1354 	 * isolation
1355 	 */
1356 	if (tt_local_entry &&
1357 	    _batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
1358 		goto out;
1359 
1360 	rcu_read_lock();
1361 	best_entry = batadv_transtable_best_orig(tt_global_entry);
1362 	/* found anything? */
1363 	if (best_entry)
1364 		orig_node = best_entry->orig_node;
1365 	if (orig_node && !atomic_inc_not_zero(&orig_node->refcount))
1366 		orig_node = NULL;
1367 	rcu_read_unlock();
1368 
1369 out:
1370 	if (tt_global_entry)
1371 		batadv_tt_global_entry_free_ref(tt_global_entry);
1372 	if (tt_local_entry)
1373 		batadv_tt_local_entry_free_ref(tt_local_entry);
1374 
1375 	return orig_node;
1376 }
1377 
1378 /* Calculates the checksum of the local table of a given orig_node */
1379 static uint16_t batadv_tt_global_crc(struct batadv_priv *bat_priv,
1380 				     struct batadv_orig_node *orig_node)
1381 {
1382 	uint16_t total = 0, total_one;
1383 	struct batadv_hashtable *hash = bat_priv->tt.global_hash;
1384 	struct batadv_tt_common_entry *tt_common;
1385 	struct batadv_tt_global_entry *tt_global;
1386 	struct hlist_head *head;
1387 	uint32_t i;
1388 	int j;
1389 
1390 	for (i = 0; i < hash->size; i++) {
1391 		head = &hash->table[i];
1392 
1393 		rcu_read_lock();
1394 		hlist_for_each_entry_rcu(tt_common, head, hash_entry) {
1395 			tt_global = container_of(tt_common,
1396 						 struct batadv_tt_global_entry,
1397 						 common);
1398 			/* Roaming clients are in the global table for
1399 			 * consistency only. They don't have to be
1400 			 * taken into account while computing the
1401 			 * global crc
1402 			 */
1403 			if (tt_common->flags & BATADV_TT_CLIENT_ROAM)
1404 				continue;
1405 			/* Temporary clients have not been announced yet, so
1406 			 * they have to be skipped while computing the global
1407 			 * crc
1408 			 */
1409 			if (tt_common->flags & BATADV_TT_CLIENT_TEMP)
1410 				continue;
1411 
1412 			/* find out if this global entry is announced by this
1413 			 * originator
1414 			 */
1415 			if (!batadv_tt_global_entry_has_orig(tt_global,
1416 							     orig_node))
1417 				continue;
1418 
1419 			total_one = 0;
1420 			for (j = 0; j < ETH_ALEN; j++)
1421 				total_one = crc16_byte(total_one,
1422 						       tt_common->addr[j]);
1423 			total ^= total_one;
1424 		}
1425 		rcu_read_unlock();
1426 	}
1427 
1428 	return total;
1429 }
1430 
1431 /* Calculates the checksum of the local table */
1432 static uint16_t batadv_tt_local_crc(struct batadv_priv *bat_priv)
1433 {
1434 	uint16_t total = 0, total_one;
1435 	struct batadv_hashtable *hash = bat_priv->tt.local_hash;
1436 	struct batadv_tt_common_entry *tt_common;
1437 	struct hlist_head *head;
1438 	uint32_t i;
1439 	int j;
1440 
1441 	for (i = 0; i < hash->size; i++) {
1442 		head = &hash->table[i];
1443 
1444 		rcu_read_lock();
1445 		hlist_for_each_entry_rcu(tt_common, head, hash_entry) {
1446 			/* not yet committed clients have not to be taken into
1447 			 * account while computing the CRC
1448 			 */
1449 			if (tt_common->flags & BATADV_TT_CLIENT_NEW)
1450 				continue;
1451 			total_one = 0;
1452 			for (j = 0; j < ETH_ALEN; j++)
1453 				total_one = crc16_byte(total_one,
1454 						       tt_common->addr[j]);
1455 			total ^= total_one;
1456 		}
1457 		rcu_read_unlock();
1458 	}
1459 
1460 	return total;
1461 }
1462 
1463 static void batadv_tt_req_list_free(struct batadv_priv *bat_priv)
1464 {
1465 	struct batadv_tt_req_node *node, *safe;
1466 
1467 	spin_lock_bh(&bat_priv->tt.req_list_lock);
1468 
1469 	list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
1470 		list_del(&node->list);
1471 		kfree(node);
1472 	}
1473 
1474 	spin_unlock_bh(&bat_priv->tt.req_list_lock);
1475 }
1476 
1477 static void batadv_tt_save_orig_buffer(struct batadv_priv *bat_priv,
1478 				       struct batadv_orig_node *orig_node,
1479 				       const unsigned char *tt_buff,
1480 				       uint8_t tt_num_changes)
1481 {
1482 	uint16_t tt_buff_len = batadv_tt_len(tt_num_changes);
1483 
1484 	/* Replace the old buffer only if I received something in the
1485 	 * last OGM (the OGM could carry no changes)
1486 	 */
1487 	spin_lock_bh(&orig_node->tt_buff_lock);
1488 	if (tt_buff_len > 0) {
1489 		kfree(orig_node->tt_buff);
1490 		orig_node->tt_buff_len = 0;
1491 		orig_node->tt_buff = kmalloc(tt_buff_len, GFP_ATOMIC);
1492 		if (orig_node->tt_buff) {
1493 			memcpy(orig_node->tt_buff, tt_buff, tt_buff_len);
1494 			orig_node->tt_buff_len = tt_buff_len;
1495 		}
1496 	}
1497 	spin_unlock_bh(&orig_node->tt_buff_lock);
1498 }
1499 
1500 static void batadv_tt_req_purge(struct batadv_priv *bat_priv)
1501 {
1502 	struct batadv_tt_req_node *node, *safe;
1503 
1504 	spin_lock_bh(&bat_priv->tt.req_list_lock);
1505 	list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
1506 		if (batadv_has_timed_out(node->issued_at,
1507 					 BATADV_TT_REQUEST_TIMEOUT)) {
1508 			list_del(&node->list);
1509 			kfree(node);
1510 		}
1511 	}
1512 	spin_unlock_bh(&bat_priv->tt.req_list_lock);
1513 }
1514 
1515 /* returns the pointer to the new tt_req_node struct if no request
1516  * has already been issued for this orig_node, NULL otherwise
1517  */
1518 static struct batadv_tt_req_node *
1519 batadv_new_tt_req_node(struct batadv_priv *bat_priv,
1520 		       struct batadv_orig_node *orig_node)
1521 {
1522 	struct batadv_tt_req_node *tt_req_node_tmp, *tt_req_node = NULL;
1523 
1524 	spin_lock_bh(&bat_priv->tt.req_list_lock);
1525 	list_for_each_entry(tt_req_node_tmp, &bat_priv->tt.req_list, list) {
1526 		if (batadv_compare_eth(tt_req_node_tmp, orig_node) &&
1527 		    !batadv_has_timed_out(tt_req_node_tmp->issued_at,
1528 					  BATADV_TT_REQUEST_TIMEOUT))
1529 			goto unlock;
1530 	}
1531 
1532 	tt_req_node = kmalloc(sizeof(*tt_req_node), GFP_ATOMIC);
1533 	if (!tt_req_node)
1534 		goto unlock;
1535 
1536 	memcpy(tt_req_node->addr, orig_node->orig, ETH_ALEN);
1537 	tt_req_node->issued_at = jiffies;
1538 
1539 	list_add(&tt_req_node->list, &bat_priv->tt.req_list);
1540 unlock:
1541 	spin_unlock_bh(&bat_priv->tt.req_list_lock);
1542 	return tt_req_node;
1543 }
1544 
1545 /* data_ptr is useless here, but has to be kept to respect the prototype */
1546 static int batadv_tt_local_valid_entry(const void *entry_ptr,
1547 				       const void *data_ptr)
1548 {
1549 	const struct batadv_tt_common_entry *tt_common_entry = entry_ptr;
1550 
1551 	if (tt_common_entry->flags & BATADV_TT_CLIENT_NEW)
1552 		return 0;
1553 	return 1;
1554 }
1555 
1556 static int batadv_tt_global_valid(const void *entry_ptr,
1557 				  const void *data_ptr)
1558 {
1559 	const struct batadv_tt_common_entry *tt_common_entry = entry_ptr;
1560 	const struct batadv_tt_global_entry *tt_global_entry;
1561 	const struct batadv_orig_node *orig_node = data_ptr;
1562 
1563 	if (tt_common_entry->flags & BATADV_TT_CLIENT_ROAM ||
1564 	    tt_common_entry->flags & BATADV_TT_CLIENT_TEMP)
1565 		return 0;
1566 
1567 	tt_global_entry = container_of(tt_common_entry,
1568 				       struct batadv_tt_global_entry,
1569 				       common);
1570 
1571 	return batadv_tt_global_entry_has_orig(tt_global_entry, orig_node);
1572 }
1573 
1574 static struct sk_buff *
1575 batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
1576 			      struct batadv_hashtable *hash,
1577 			      struct batadv_priv *bat_priv,
1578 			      int (*valid_cb)(const void *, const void *),
1579 			      void *cb_data)
1580 {
1581 	struct batadv_tt_common_entry *tt_common_entry;
1582 	struct batadv_tt_query_packet *tt_response;
1583 	struct batadv_tt_change *tt_change;
1584 	struct hlist_head *head;
1585 	struct sk_buff *skb = NULL;
1586 	uint16_t tt_tot, tt_count;
1587 	ssize_t tt_query_size = sizeof(struct batadv_tt_query_packet);
1588 	uint32_t i;
1589 	size_t len;
1590 
1591 	if (tt_query_size + tt_len > bat_priv->soft_iface->mtu) {
1592 		tt_len = bat_priv->soft_iface->mtu - tt_query_size;
1593 		tt_len -= tt_len % sizeof(struct batadv_tt_change);
1594 	}
1595 	tt_tot = tt_len / sizeof(struct batadv_tt_change);
1596 
1597 	len = tt_query_size + tt_len;
1598 	skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1599 	if (!skb)
1600 		goto out;
1601 
1602 	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1603 	tt_response = (struct batadv_tt_query_packet *)skb_put(skb, len);
1604 	tt_response->ttvn = ttvn;
1605 
1606 	tt_change = (struct batadv_tt_change *)(skb->data + tt_query_size);
1607 	tt_count = 0;
1608 
1609 	rcu_read_lock();
1610 	for (i = 0; i < hash->size; i++) {
1611 		head = &hash->table[i];
1612 
1613 		hlist_for_each_entry_rcu(tt_common_entry,
1614 					 head, hash_entry) {
1615 			if (tt_count == tt_tot)
1616 				break;
1617 
1618 			if ((valid_cb) && (!valid_cb(tt_common_entry, cb_data)))
1619 				continue;
1620 
1621 			memcpy(tt_change->addr, tt_common_entry->addr,
1622 			       ETH_ALEN);
1623 			tt_change->flags = tt_common_entry->flags;
1624 
1625 			tt_count++;
1626 			tt_change++;
1627 		}
1628 	}
1629 	rcu_read_unlock();
1630 
1631 	/* store in the message the number of entries we have successfully
1632 	 * copied
1633 	 */
1634 	tt_response->tt_data = htons(tt_count);
1635 
1636 out:
1637 	return skb;
1638 }
1639 
1640 static int batadv_send_tt_request(struct batadv_priv *bat_priv,
1641 				  struct batadv_orig_node *dst_orig_node,
1642 				  uint8_t ttvn, uint16_t tt_crc,
1643 				  bool full_table)
1644 {
1645 	struct sk_buff *skb = NULL;
1646 	struct batadv_tt_query_packet *tt_request;
1647 	struct batadv_hard_iface *primary_if;
1648 	struct batadv_tt_req_node *tt_req_node = NULL;
1649 	int ret = 1;
1650 	size_t tt_req_len;
1651 
1652 	primary_if = batadv_primary_if_get_selected(bat_priv);
1653 	if (!primary_if)
1654 		goto out;
1655 
1656 	/* The new tt_req will be issued only if I'm not waiting for a
1657 	 * reply from the same orig_node yet
1658 	 */
1659 	tt_req_node = batadv_new_tt_req_node(bat_priv, dst_orig_node);
1660 	if (!tt_req_node)
1661 		goto out;
1662 
1663 	skb = dev_alloc_skb(sizeof(*tt_request) + ETH_HLEN + NET_IP_ALIGN);
1664 	if (!skb)
1665 		goto out;
1666 
1667 	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1668 
1669 	tt_req_len = sizeof(*tt_request);
1670 	tt_request = (struct batadv_tt_query_packet *)skb_put(skb, tt_req_len);
1671 
1672 	tt_request->header.packet_type = BATADV_TT_QUERY;
1673 	tt_request->header.version = BATADV_COMPAT_VERSION;
1674 	memcpy(tt_request->src, primary_if->net_dev->dev_addr, ETH_ALEN);
1675 	memcpy(tt_request->dst, dst_orig_node->orig, ETH_ALEN);
1676 	tt_request->header.ttl = BATADV_TTL;
1677 	tt_request->ttvn = ttvn;
1678 	tt_request->tt_data = htons(tt_crc);
1679 	tt_request->flags = BATADV_TT_REQUEST;
1680 
1681 	if (full_table)
1682 		tt_request->flags |= BATADV_TT_FULL_TABLE;
1683 
1684 	batadv_dbg(BATADV_DBG_TT, bat_priv, "Sending TT_REQUEST to %pM [%c]\n",
1685 		   dst_orig_node->orig, (full_table ? 'F' : '.'));
1686 
1687 	batadv_inc_counter(bat_priv, BATADV_CNT_TT_REQUEST_TX);
1688 
1689 	if (batadv_send_skb_to_orig(skb, dst_orig_node, NULL))
1690 		ret = 0;
1691 
1692 out:
1693 	if (primary_if)
1694 		batadv_hardif_free_ref(primary_if);
1695 	if (ret)
1696 		kfree_skb(skb);
1697 	if (ret && tt_req_node) {
1698 		spin_lock_bh(&bat_priv->tt.req_list_lock);
1699 		list_del(&tt_req_node->list);
1700 		spin_unlock_bh(&bat_priv->tt.req_list_lock);
1701 		kfree(tt_req_node);
1702 	}
1703 	return ret;
1704 }
1705 
1706 static bool
1707 batadv_send_other_tt_response(struct batadv_priv *bat_priv,
1708 			      struct batadv_tt_query_packet *tt_request)
1709 {
1710 	struct batadv_orig_node *req_dst_orig_node;
1711 	struct batadv_orig_node *res_dst_orig_node = NULL;
1712 	uint8_t orig_ttvn, req_ttvn, ttvn;
1713 	int ret = false;
1714 	unsigned char *tt_buff;
1715 	bool full_table;
1716 	uint16_t tt_len, tt_tot;
1717 	struct sk_buff *skb = NULL;
1718 	struct batadv_tt_query_packet *tt_response;
1719 	uint8_t *packet_pos;
1720 	size_t len;
1721 
1722 	batadv_dbg(BATADV_DBG_TT, bat_priv,
1723 		   "Received TT_REQUEST from %pM for ttvn: %u (%pM) [%c]\n",
1724 		   tt_request->src, tt_request->ttvn, tt_request->dst,
1725 		   (tt_request->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1726 
1727 	/* Let's get the orig node of the REAL destination */
1728 	req_dst_orig_node = batadv_orig_hash_find(bat_priv, tt_request->dst);
1729 	if (!req_dst_orig_node)
1730 		goto out;
1731 
1732 	res_dst_orig_node = batadv_orig_hash_find(bat_priv, tt_request->src);
1733 	if (!res_dst_orig_node)
1734 		goto out;
1735 
1736 	orig_ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
1737 	req_ttvn = tt_request->ttvn;
1738 
1739 	/* I don't have the requested data */
1740 	if (orig_ttvn != req_ttvn ||
1741 	    tt_request->tt_data != htons(req_dst_orig_node->tt_crc))
1742 		goto out;
1743 
1744 	/* If the full table has been explicitly requested */
1745 	if (tt_request->flags & BATADV_TT_FULL_TABLE ||
1746 	    !req_dst_orig_node->tt_buff)
1747 		full_table = true;
1748 	else
1749 		full_table = false;
1750 
1751 	/* In this version, fragmentation is not implemented, then
1752 	 * I'll send only one packet with as much TT entries as I can
1753 	 */
1754 	if (!full_table) {
1755 		spin_lock_bh(&req_dst_orig_node->tt_buff_lock);
1756 		tt_len = req_dst_orig_node->tt_buff_len;
1757 		tt_tot = tt_len / sizeof(struct batadv_tt_change);
1758 
1759 		len = sizeof(*tt_response) + tt_len;
1760 		skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1761 		if (!skb)
1762 			goto unlock;
1763 
1764 		skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1765 		packet_pos = skb_put(skb, len);
1766 		tt_response = (struct batadv_tt_query_packet *)packet_pos;
1767 		tt_response->ttvn = req_ttvn;
1768 		tt_response->tt_data = htons(tt_tot);
1769 
1770 		tt_buff = skb->data + sizeof(*tt_response);
1771 		/* Copy the last orig_node's OGM buffer */
1772 		memcpy(tt_buff, req_dst_orig_node->tt_buff,
1773 		       req_dst_orig_node->tt_buff_len);
1774 
1775 		spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
1776 	} else {
1777 		tt_len = (uint16_t)atomic_read(&req_dst_orig_node->tt_size);
1778 		tt_len *= sizeof(struct batadv_tt_change);
1779 		ttvn = (uint8_t)atomic_read(&req_dst_orig_node->last_ttvn);
1780 
1781 		skb = batadv_tt_response_fill_table(tt_len, ttvn,
1782 						    bat_priv->tt.global_hash,
1783 						    bat_priv,
1784 						    batadv_tt_global_valid,
1785 						    req_dst_orig_node);
1786 		if (!skb)
1787 			goto out;
1788 
1789 		tt_response = (struct batadv_tt_query_packet *)skb->data;
1790 	}
1791 
1792 	tt_response->header.packet_type = BATADV_TT_QUERY;
1793 	tt_response->header.version = BATADV_COMPAT_VERSION;
1794 	tt_response->header.ttl = BATADV_TTL;
1795 	memcpy(tt_response->src, req_dst_orig_node->orig, ETH_ALEN);
1796 	memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
1797 	tt_response->flags = BATADV_TT_RESPONSE;
1798 
1799 	if (full_table)
1800 		tt_response->flags |= BATADV_TT_FULL_TABLE;
1801 
1802 	batadv_dbg(BATADV_DBG_TT, bat_priv,
1803 		   "Sending TT_RESPONSE %pM for %pM (ttvn: %u)\n",
1804 		   res_dst_orig_node->orig, req_dst_orig_node->orig, req_ttvn);
1805 
1806 	batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
1807 
1808 	if (batadv_send_skb_to_orig(skb, res_dst_orig_node, NULL))
1809 		ret = true;
1810 	goto out;
1811 
1812 unlock:
1813 	spin_unlock_bh(&req_dst_orig_node->tt_buff_lock);
1814 
1815 out:
1816 	if (res_dst_orig_node)
1817 		batadv_orig_node_free_ref(res_dst_orig_node);
1818 	if (req_dst_orig_node)
1819 		batadv_orig_node_free_ref(req_dst_orig_node);
1820 	if (!ret)
1821 		kfree_skb(skb);
1822 	return ret;
1823 }
1824 
1825 static bool
1826 batadv_send_my_tt_response(struct batadv_priv *bat_priv,
1827 			   struct batadv_tt_query_packet *tt_request)
1828 {
1829 	struct batadv_orig_node *orig_node;
1830 	struct batadv_hard_iface *primary_if = NULL;
1831 	uint8_t my_ttvn, req_ttvn, ttvn;
1832 	int ret = false;
1833 	unsigned char *tt_buff;
1834 	bool full_table;
1835 	uint16_t tt_len, tt_tot;
1836 	struct sk_buff *skb = NULL;
1837 	struct batadv_tt_query_packet *tt_response;
1838 	uint8_t *packet_pos;
1839 	size_t len;
1840 
1841 	batadv_dbg(BATADV_DBG_TT, bat_priv,
1842 		   "Received TT_REQUEST from %pM for ttvn: %u (me) [%c]\n",
1843 		   tt_request->src, tt_request->ttvn,
1844 		   (tt_request->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1845 
1846 
1847 	my_ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
1848 	req_ttvn = tt_request->ttvn;
1849 
1850 	orig_node = batadv_orig_hash_find(bat_priv, tt_request->src);
1851 	if (!orig_node)
1852 		goto out;
1853 
1854 	primary_if = batadv_primary_if_get_selected(bat_priv);
1855 	if (!primary_if)
1856 		goto out;
1857 
1858 	/* If the full table has been explicitly requested or the gap
1859 	 * is too big send the whole local translation table
1860 	 */
1861 	if (tt_request->flags & BATADV_TT_FULL_TABLE || my_ttvn != req_ttvn ||
1862 	    !bat_priv->tt.last_changeset)
1863 		full_table = true;
1864 	else
1865 		full_table = false;
1866 
1867 	/* In this version, fragmentation is not implemented, then
1868 	 * I'll send only one packet with as much TT entries as I can
1869 	 */
1870 	if (!full_table) {
1871 		spin_lock_bh(&bat_priv->tt.last_changeset_lock);
1872 		tt_len = bat_priv->tt.last_changeset_len;
1873 		tt_tot = tt_len / sizeof(struct batadv_tt_change);
1874 
1875 		len = sizeof(*tt_response) + tt_len;
1876 		skb = dev_alloc_skb(len + ETH_HLEN + NET_IP_ALIGN);
1877 		if (!skb)
1878 			goto unlock;
1879 
1880 		skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
1881 		packet_pos = skb_put(skb, len);
1882 		tt_response = (struct batadv_tt_query_packet *)packet_pos;
1883 		tt_response->ttvn = req_ttvn;
1884 		tt_response->tt_data = htons(tt_tot);
1885 
1886 		tt_buff = skb->data + sizeof(*tt_response);
1887 		memcpy(tt_buff, bat_priv->tt.last_changeset,
1888 		       bat_priv->tt.last_changeset_len);
1889 		spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
1890 	} else {
1891 		tt_len = (uint16_t)atomic_read(&bat_priv->tt.local_entry_num);
1892 		tt_len *= sizeof(struct batadv_tt_change);
1893 		ttvn = (uint8_t)atomic_read(&bat_priv->tt.vn);
1894 
1895 		skb = batadv_tt_response_fill_table(tt_len, ttvn,
1896 						    bat_priv->tt.local_hash,
1897 						    bat_priv,
1898 						    batadv_tt_local_valid_entry,
1899 						    NULL);
1900 		if (!skb)
1901 			goto out;
1902 
1903 		tt_response = (struct batadv_tt_query_packet *)skb->data;
1904 	}
1905 
1906 	tt_response->header.packet_type = BATADV_TT_QUERY;
1907 	tt_response->header.version = BATADV_COMPAT_VERSION;
1908 	tt_response->header.ttl = BATADV_TTL;
1909 	memcpy(tt_response->src, primary_if->net_dev->dev_addr, ETH_ALEN);
1910 	memcpy(tt_response->dst, tt_request->src, ETH_ALEN);
1911 	tt_response->flags = BATADV_TT_RESPONSE;
1912 
1913 	if (full_table)
1914 		tt_response->flags |= BATADV_TT_FULL_TABLE;
1915 
1916 	batadv_dbg(BATADV_DBG_TT, bat_priv,
1917 		   "Sending TT_RESPONSE to %pM [%c]\n",
1918 		   orig_node->orig,
1919 		   (tt_response->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
1920 
1921 	batadv_inc_counter(bat_priv, BATADV_CNT_TT_RESPONSE_TX);
1922 
1923 	if (batadv_send_skb_to_orig(skb, orig_node, NULL))
1924 		ret = true;
1925 	goto out;
1926 
1927 unlock:
1928 	spin_unlock_bh(&bat_priv->tt.last_changeset_lock);
1929 out:
1930 	if (orig_node)
1931 		batadv_orig_node_free_ref(orig_node);
1932 	if (primary_if)
1933 		batadv_hardif_free_ref(primary_if);
1934 	if (!ret)
1935 		kfree_skb(skb);
1936 	/* This packet was for me, so it doesn't need to be re-routed */
1937 	return true;
1938 }
1939 
1940 bool batadv_send_tt_response(struct batadv_priv *bat_priv,
1941 			     struct batadv_tt_query_packet *tt_request)
1942 {
1943 	if (batadv_is_my_mac(bat_priv, tt_request->dst)) {
1944 		/* don't answer backbone gws! */
1945 		if (batadv_bla_is_backbone_gw_orig(bat_priv, tt_request->src))
1946 			return true;
1947 
1948 		return batadv_send_my_tt_response(bat_priv, tt_request);
1949 	} else {
1950 		return batadv_send_other_tt_response(bat_priv, tt_request);
1951 	}
1952 }
1953 
1954 static void _batadv_tt_update_changes(struct batadv_priv *bat_priv,
1955 				      struct batadv_orig_node *orig_node,
1956 				      struct batadv_tt_change *tt_change,
1957 				      uint16_t tt_num_changes, uint8_t ttvn)
1958 {
1959 	int i;
1960 	int roams;
1961 
1962 	for (i = 0; i < tt_num_changes; i++) {
1963 		if ((tt_change + i)->flags & BATADV_TT_CLIENT_DEL) {
1964 			roams = (tt_change + i)->flags & BATADV_TT_CLIENT_ROAM;
1965 			batadv_tt_global_del(bat_priv, orig_node,
1966 					     (tt_change + i)->addr,
1967 					     "tt removed by changes",
1968 					     roams);
1969 		} else {
1970 			if (!batadv_tt_global_add(bat_priv, orig_node,
1971 						  (tt_change + i)->addr,
1972 						  (tt_change + i)->flags, ttvn))
1973 				/* In case of problem while storing a
1974 				 * global_entry, we stop the updating
1975 				 * procedure without committing the
1976 				 * ttvn change. This will avoid to send
1977 				 * corrupted data on tt_request
1978 				 */
1979 				return;
1980 		}
1981 	}
1982 	orig_node->tt_initialised = true;
1983 }
1984 
1985 static void batadv_tt_fill_gtable(struct batadv_priv *bat_priv,
1986 				  struct batadv_tt_query_packet *tt_response)
1987 {
1988 	struct batadv_orig_node *orig_node;
1989 
1990 	orig_node = batadv_orig_hash_find(bat_priv, tt_response->src);
1991 	if (!orig_node)
1992 		goto out;
1993 
1994 	/* Purge the old table first.. */
1995 	batadv_tt_global_del_orig(bat_priv, orig_node, "Received full table");
1996 
1997 	_batadv_tt_update_changes(bat_priv, orig_node,
1998 				  (struct batadv_tt_change *)(tt_response + 1),
1999 				  ntohs(tt_response->tt_data),
2000 				  tt_response->ttvn);
2001 
2002 	spin_lock_bh(&orig_node->tt_buff_lock);
2003 	kfree(orig_node->tt_buff);
2004 	orig_node->tt_buff_len = 0;
2005 	orig_node->tt_buff = NULL;
2006 	spin_unlock_bh(&orig_node->tt_buff_lock);
2007 
2008 	atomic_set(&orig_node->last_ttvn, tt_response->ttvn);
2009 
2010 out:
2011 	if (orig_node)
2012 		batadv_orig_node_free_ref(orig_node);
2013 }
2014 
2015 static void batadv_tt_update_changes(struct batadv_priv *bat_priv,
2016 				     struct batadv_orig_node *orig_node,
2017 				     uint16_t tt_num_changes, uint8_t ttvn,
2018 				     struct batadv_tt_change *tt_change)
2019 {
2020 	_batadv_tt_update_changes(bat_priv, orig_node, tt_change,
2021 				  tt_num_changes, ttvn);
2022 
2023 	batadv_tt_save_orig_buffer(bat_priv, orig_node,
2024 				   (unsigned char *)tt_change, tt_num_changes);
2025 	atomic_set(&orig_node->last_ttvn, ttvn);
2026 }
2027 
2028 bool batadv_is_my_client(struct batadv_priv *bat_priv, const uint8_t *addr)
2029 {
2030 	struct batadv_tt_local_entry *tt_local_entry;
2031 	bool ret = false;
2032 
2033 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
2034 	if (!tt_local_entry)
2035 		goto out;
2036 	/* Check if the client has been logically deleted (but is kept for
2037 	 * consistency purpose)
2038 	 */
2039 	if ((tt_local_entry->common.flags & BATADV_TT_CLIENT_PENDING) ||
2040 	    (tt_local_entry->common.flags & BATADV_TT_CLIENT_ROAM))
2041 		goto out;
2042 	ret = true;
2043 out:
2044 	if (tt_local_entry)
2045 		batadv_tt_local_entry_free_ref(tt_local_entry);
2046 	return ret;
2047 }
2048 
2049 void batadv_handle_tt_response(struct batadv_priv *bat_priv,
2050 			       struct batadv_tt_query_packet *tt_response)
2051 {
2052 	struct batadv_tt_req_node *node, *safe;
2053 	struct batadv_orig_node *orig_node = NULL;
2054 	struct batadv_tt_change *tt_change;
2055 
2056 	batadv_dbg(BATADV_DBG_TT, bat_priv,
2057 		   "Received TT_RESPONSE from %pM for ttvn %d t_size: %d [%c]\n",
2058 		   tt_response->src, tt_response->ttvn,
2059 		   ntohs(tt_response->tt_data),
2060 		   (tt_response->flags & BATADV_TT_FULL_TABLE ? 'F' : '.'));
2061 
2062 	/* we should have never asked a backbone gw */
2063 	if (batadv_bla_is_backbone_gw_orig(bat_priv, tt_response->src))
2064 		goto out;
2065 
2066 	orig_node = batadv_orig_hash_find(bat_priv, tt_response->src);
2067 	if (!orig_node)
2068 		goto out;
2069 
2070 	if (tt_response->flags & BATADV_TT_FULL_TABLE) {
2071 		batadv_tt_fill_gtable(bat_priv, tt_response);
2072 	} else {
2073 		tt_change = (struct batadv_tt_change *)(tt_response + 1);
2074 		batadv_tt_update_changes(bat_priv, orig_node,
2075 					 ntohs(tt_response->tt_data),
2076 					 tt_response->ttvn, tt_change);
2077 	}
2078 
2079 	/* Delete the tt_req_node from pending tt_requests list */
2080 	spin_lock_bh(&bat_priv->tt.req_list_lock);
2081 	list_for_each_entry_safe(node, safe, &bat_priv->tt.req_list, list) {
2082 		if (!batadv_compare_eth(node->addr, tt_response->src))
2083 			continue;
2084 		list_del(&node->list);
2085 		kfree(node);
2086 	}
2087 	spin_unlock_bh(&bat_priv->tt.req_list_lock);
2088 
2089 	/* Recalculate the CRC for this orig_node and store it */
2090 	orig_node->tt_crc = batadv_tt_global_crc(bat_priv, orig_node);
2091 out:
2092 	if (orig_node)
2093 		batadv_orig_node_free_ref(orig_node);
2094 }
2095 
2096 int batadv_tt_init(struct batadv_priv *bat_priv)
2097 {
2098 	int ret;
2099 
2100 	ret = batadv_tt_local_init(bat_priv);
2101 	if (ret < 0)
2102 		return ret;
2103 
2104 	ret = batadv_tt_global_init(bat_priv);
2105 	if (ret < 0)
2106 		return ret;
2107 
2108 	INIT_DELAYED_WORK(&bat_priv->tt.work, batadv_tt_purge);
2109 	queue_delayed_work(batadv_event_workqueue, &bat_priv->tt.work,
2110 			   msecs_to_jiffies(BATADV_TT_WORK_PERIOD));
2111 
2112 	return 1;
2113 }
2114 
2115 static void batadv_tt_roam_list_free(struct batadv_priv *bat_priv)
2116 {
2117 	struct batadv_tt_roam_node *node, *safe;
2118 
2119 	spin_lock_bh(&bat_priv->tt.roam_list_lock);
2120 
2121 	list_for_each_entry_safe(node, safe, &bat_priv->tt.roam_list, list) {
2122 		list_del(&node->list);
2123 		kfree(node);
2124 	}
2125 
2126 	spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2127 }
2128 
2129 static void batadv_tt_roam_purge(struct batadv_priv *bat_priv)
2130 {
2131 	struct batadv_tt_roam_node *node, *safe;
2132 
2133 	spin_lock_bh(&bat_priv->tt.roam_list_lock);
2134 	list_for_each_entry_safe(node, safe, &bat_priv->tt.roam_list, list) {
2135 		if (!batadv_has_timed_out(node->first_time,
2136 					  BATADV_ROAMING_MAX_TIME))
2137 			continue;
2138 
2139 		list_del(&node->list);
2140 		kfree(node);
2141 	}
2142 	spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2143 }
2144 
2145 /* This function checks whether the client already reached the
2146  * maximum number of possible roaming phases. In this case the ROAMING_ADV
2147  * will not be sent.
2148  *
2149  * returns true if the ROAMING_ADV can be sent, false otherwise
2150  */
2151 static bool batadv_tt_check_roam_count(struct batadv_priv *bat_priv,
2152 				       uint8_t *client)
2153 {
2154 	struct batadv_tt_roam_node *tt_roam_node;
2155 	bool ret = false;
2156 
2157 	spin_lock_bh(&bat_priv->tt.roam_list_lock);
2158 	/* The new tt_req will be issued only if I'm not waiting for a
2159 	 * reply from the same orig_node yet
2160 	 */
2161 	list_for_each_entry(tt_roam_node, &bat_priv->tt.roam_list, list) {
2162 		if (!batadv_compare_eth(tt_roam_node->addr, client))
2163 			continue;
2164 
2165 		if (batadv_has_timed_out(tt_roam_node->first_time,
2166 					 BATADV_ROAMING_MAX_TIME))
2167 			continue;
2168 
2169 		if (!batadv_atomic_dec_not_zero(&tt_roam_node->counter))
2170 			/* Sorry, you roamed too many times! */
2171 			goto unlock;
2172 		ret = true;
2173 		break;
2174 	}
2175 
2176 	if (!ret) {
2177 		tt_roam_node = kmalloc(sizeof(*tt_roam_node), GFP_ATOMIC);
2178 		if (!tt_roam_node)
2179 			goto unlock;
2180 
2181 		tt_roam_node->first_time = jiffies;
2182 		atomic_set(&tt_roam_node->counter,
2183 			   BATADV_ROAMING_MAX_COUNT - 1);
2184 		memcpy(tt_roam_node->addr, client, ETH_ALEN);
2185 
2186 		list_add(&tt_roam_node->list, &bat_priv->tt.roam_list);
2187 		ret = true;
2188 	}
2189 
2190 unlock:
2191 	spin_unlock_bh(&bat_priv->tt.roam_list_lock);
2192 	return ret;
2193 }
2194 
2195 static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
2196 				 struct batadv_orig_node *orig_node)
2197 {
2198 	struct sk_buff *skb = NULL;
2199 	struct batadv_roam_adv_packet *roam_adv_packet;
2200 	int ret = 1;
2201 	struct batadv_hard_iface *primary_if;
2202 	size_t len = sizeof(*roam_adv_packet);
2203 
2204 	/* before going on we have to check whether the client has
2205 	 * already roamed to us too many times
2206 	 */
2207 	if (!batadv_tt_check_roam_count(bat_priv, client))
2208 		goto out;
2209 
2210 	skb = dev_alloc_skb(sizeof(*roam_adv_packet) + ETH_HLEN + NET_IP_ALIGN);
2211 	if (!skb)
2212 		goto out;
2213 
2214 	skb_reserve(skb, ETH_HLEN + NET_IP_ALIGN);
2215 
2216 	roam_adv_packet = (struct batadv_roam_adv_packet *)skb_put(skb, len);
2217 
2218 	roam_adv_packet->header.packet_type = BATADV_ROAM_ADV;
2219 	roam_adv_packet->header.version = BATADV_COMPAT_VERSION;
2220 	roam_adv_packet->header.ttl = BATADV_TTL;
2221 	roam_adv_packet->reserved = 0;
2222 	primary_if = batadv_primary_if_get_selected(bat_priv);
2223 	if (!primary_if)
2224 		goto out;
2225 	memcpy(roam_adv_packet->src, primary_if->net_dev->dev_addr, ETH_ALEN);
2226 	batadv_hardif_free_ref(primary_if);
2227 	memcpy(roam_adv_packet->dst, orig_node->orig, ETH_ALEN);
2228 	memcpy(roam_adv_packet->client, client, ETH_ALEN);
2229 
2230 	batadv_dbg(BATADV_DBG_TT, bat_priv,
2231 		   "Sending ROAMING_ADV to %pM (client %pM)\n",
2232 		   orig_node->orig, client);
2233 
2234 	batadv_inc_counter(bat_priv, BATADV_CNT_TT_ROAM_ADV_TX);
2235 
2236 	if (batadv_send_skb_to_orig(skb, orig_node, NULL))
2237 		ret = 0;
2238 
2239 out:
2240 	if (ret && skb)
2241 		kfree_skb(skb);
2242 	return;
2243 }
2244 
2245 static void batadv_tt_purge(struct work_struct *work)
2246 {
2247 	struct delayed_work *delayed_work;
2248 	struct batadv_priv_tt *priv_tt;
2249 	struct batadv_priv *bat_priv;
2250 
2251 	delayed_work = container_of(work, struct delayed_work, work);
2252 	priv_tt = container_of(delayed_work, struct batadv_priv_tt, work);
2253 	bat_priv = container_of(priv_tt, struct batadv_priv, tt);
2254 
2255 	batadv_tt_local_purge(bat_priv);
2256 	batadv_tt_global_purge(bat_priv);
2257 	batadv_tt_req_purge(bat_priv);
2258 	batadv_tt_roam_purge(bat_priv);
2259 
2260 	queue_delayed_work(batadv_event_workqueue, &bat_priv->tt.work,
2261 			   msecs_to_jiffies(BATADV_TT_WORK_PERIOD));
2262 }
2263 
2264 void batadv_tt_free(struct batadv_priv *bat_priv)
2265 {
2266 	cancel_delayed_work_sync(&bat_priv->tt.work);
2267 
2268 	batadv_tt_local_table_free(bat_priv);
2269 	batadv_tt_global_table_free(bat_priv);
2270 	batadv_tt_req_list_free(bat_priv);
2271 	batadv_tt_changes_list_free(bat_priv);
2272 	batadv_tt_roam_list_free(bat_priv);
2273 
2274 	kfree(bat_priv->tt.last_changeset);
2275 }
2276 
2277 /* This function will enable or disable the specified flags for all the entries
2278  * in the given hash table and returns the number of modified entries
2279  */
2280 static uint16_t batadv_tt_set_flags(struct batadv_hashtable *hash,
2281 				    uint16_t flags, bool enable)
2282 {
2283 	uint32_t i;
2284 	uint16_t changed_num = 0;
2285 	struct hlist_head *head;
2286 	struct batadv_tt_common_entry *tt_common_entry;
2287 
2288 	if (!hash)
2289 		goto out;
2290 
2291 	for (i = 0; i < hash->size; i++) {
2292 		head = &hash->table[i];
2293 
2294 		rcu_read_lock();
2295 		hlist_for_each_entry_rcu(tt_common_entry,
2296 					 head, hash_entry) {
2297 			if (enable) {
2298 				if ((tt_common_entry->flags & flags) == flags)
2299 					continue;
2300 				tt_common_entry->flags |= flags;
2301 			} else {
2302 				if (!(tt_common_entry->flags & flags))
2303 					continue;
2304 				tt_common_entry->flags &= ~flags;
2305 			}
2306 			changed_num++;
2307 		}
2308 		rcu_read_unlock();
2309 	}
2310 out:
2311 	return changed_num;
2312 }
2313 
2314 /* Purge out all the tt local entries marked with BATADV_TT_CLIENT_PENDING */
2315 static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)
2316 {
2317 	struct batadv_hashtable *hash = bat_priv->tt.local_hash;
2318 	struct batadv_tt_common_entry *tt_common;
2319 	struct batadv_tt_local_entry *tt_local;
2320 	struct hlist_node *node_tmp;
2321 	struct hlist_head *head;
2322 	spinlock_t *list_lock; /* protects write access to the hash lists */
2323 	uint32_t i;
2324 
2325 	if (!hash)
2326 		return;
2327 
2328 	for (i = 0; i < hash->size; i++) {
2329 		head = &hash->table[i];
2330 		list_lock = &hash->list_locks[i];
2331 
2332 		spin_lock_bh(list_lock);
2333 		hlist_for_each_entry_safe(tt_common, node_tmp, head,
2334 					  hash_entry) {
2335 			if (!(tt_common->flags & BATADV_TT_CLIENT_PENDING))
2336 				continue;
2337 
2338 			batadv_dbg(BATADV_DBG_TT, bat_priv,
2339 				   "Deleting local tt entry (%pM): pending\n",
2340 				   tt_common->addr);
2341 
2342 			atomic_dec(&bat_priv->tt.local_entry_num);
2343 			hlist_del_rcu(&tt_common->hash_entry);
2344 			tt_local = container_of(tt_common,
2345 						struct batadv_tt_local_entry,
2346 						common);
2347 			batadv_tt_local_entry_free_ref(tt_local);
2348 		}
2349 		spin_unlock_bh(list_lock);
2350 	}
2351 }
2352 
2353 static int batadv_tt_commit_changes(struct batadv_priv *bat_priv,
2354 				    unsigned char **packet_buff,
2355 				    int *packet_buff_len, int packet_min_len)
2356 {
2357 	uint16_t changed_num = 0;
2358 
2359 	if (atomic_read(&bat_priv->tt.local_changes) < 1)
2360 		return -ENOENT;
2361 
2362 	changed_num = batadv_tt_set_flags(bat_priv->tt.local_hash,
2363 					  BATADV_TT_CLIENT_NEW, false);
2364 
2365 	/* all reset entries have to be counted as local entries */
2366 	atomic_add(changed_num, &bat_priv->tt.local_entry_num);
2367 	batadv_tt_local_purge_pending_clients(bat_priv);
2368 	bat_priv->tt.local_crc = batadv_tt_local_crc(bat_priv);
2369 
2370 	/* Increment the TTVN only once per OGM interval */
2371 	atomic_inc(&bat_priv->tt.vn);
2372 	batadv_dbg(BATADV_DBG_TT, bat_priv,
2373 		   "Local changes committed, updating to ttvn %u\n",
2374 		   (uint8_t)atomic_read(&bat_priv->tt.vn));
2375 
2376 	/* reset the sending counter */
2377 	atomic_set(&bat_priv->tt.ogm_append_cnt, BATADV_TT_OGM_APPEND_MAX);
2378 
2379 	return batadv_tt_changes_fill_buff(bat_priv, packet_buff,
2380 					   packet_buff_len, packet_min_len);
2381 }
2382 
2383 /* when calling this function (hard_iface == primary_if) has to be true */
2384 int batadv_tt_append_diff(struct batadv_priv *bat_priv,
2385 			  unsigned char **packet_buff, int *packet_buff_len,
2386 			  int packet_min_len)
2387 {
2388 	int tt_num_changes;
2389 
2390 	/* if at least one change happened */
2391 	tt_num_changes = batadv_tt_commit_changes(bat_priv, packet_buff,
2392 						  packet_buff_len,
2393 						  packet_min_len);
2394 
2395 	/* if the changes have been sent often enough */
2396 	if ((tt_num_changes < 0) &&
2397 	    (!batadv_atomic_dec_not_zero(&bat_priv->tt.ogm_append_cnt))) {
2398 		batadv_tt_realloc_packet_buff(packet_buff, packet_buff_len,
2399 					      packet_min_len, packet_min_len);
2400 		tt_num_changes = 0;
2401 	}
2402 
2403 	return tt_num_changes;
2404 }
2405 
2406 bool batadv_is_ap_isolated(struct batadv_priv *bat_priv, uint8_t *src,
2407 			   uint8_t *dst)
2408 {
2409 	struct batadv_tt_local_entry *tt_local_entry = NULL;
2410 	struct batadv_tt_global_entry *tt_global_entry = NULL;
2411 	bool ret = false;
2412 
2413 	if (!atomic_read(&bat_priv->ap_isolation))
2414 		goto out;
2415 
2416 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, dst);
2417 	if (!tt_local_entry)
2418 		goto out;
2419 
2420 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, src);
2421 	if (!tt_global_entry)
2422 		goto out;
2423 
2424 	if (!_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
2425 		goto out;
2426 
2427 	ret = true;
2428 
2429 out:
2430 	if (tt_global_entry)
2431 		batadv_tt_global_entry_free_ref(tt_global_entry);
2432 	if (tt_local_entry)
2433 		batadv_tt_local_entry_free_ref(tt_local_entry);
2434 	return ret;
2435 }
2436 
2437 void batadv_tt_update_orig(struct batadv_priv *bat_priv,
2438 			   struct batadv_orig_node *orig_node,
2439 			   const unsigned char *tt_buff, uint8_t tt_num_changes,
2440 			   uint8_t ttvn, uint16_t tt_crc)
2441 {
2442 	uint8_t orig_ttvn = (uint8_t)atomic_read(&orig_node->last_ttvn);
2443 	bool full_table = true;
2444 	struct batadv_tt_change *tt_change;
2445 
2446 	/* don't care about a backbone gateways updates. */
2447 	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig))
2448 		return;
2449 
2450 	/* orig table not initialised AND first diff is in the OGM OR the ttvn
2451 	 * increased by one -> we can apply the attached changes
2452 	 */
2453 	if ((!orig_node->tt_initialised && ttvn == 1) ||
2454 	    ttvn - orig_ttvn == 1) {
2455 		/* the OGM could not contain the changes due to their size or
2456 		 * because they have already been sent BATADV_TT_OGM_APPEND_MAX
2457 		 * times.
2458 		 * In this case send a tt request
2459 		 */
2460 		if (!tt_num_changes) {
2461 			full_table = false;
2462 			goto request_table;
2463 		}
2464 
2465 		tt_change = (struct batadv_tt_change *)tt_buff;
2466 		batadv_tt_update_changes(bat_priv, orig_node, tt_num_changes,
2467 					 ttvn, tt_change);
2468 
2469 		/* Even if we received the precomputed crc with the OGM, we
2470 		 * prefer to recompute it to spot any possible inconsistency
2471 		 * in the global table
2472 		 */
2473 		orig_node->tt_crc = batadv_tt_global_crc(bat_priv, orig_node);
2474 
2475 		/* The ttvn alone is not enough to guarantee consistency
2476 		 * because a single value could represent different states
2477 		 * (due to the wrap around). Thus a node has to check whether
2478 		 * the resulting table (after applying the changes) is still
2479 		 * consistent or not. E.g. a node could disconnect while its
2480 		 * ttvn is X and reconnect on ttvn = X + TTVN_MAX: in this case
2481 		 * checking the CRC value is mandatory to detect the
2482 		 * inconsistency
2483 		 */
2484 		if (orig_node->tt_crc != tt_crc)
2485 			goto request_table;
2486 	} else {
2487 		/* if we missed more than one change or our tables are not
2488 		 * in sync anymore -> request fresh tt data
2489 		 */
2490 		if (!orig_node->tt_initialised || ttvn != orig_ttvn ||
2491 		    orig_node->tt_crc != tt_crc) {
2492 request_table:
2493 			batadv_dbg(BATADV_DBG_TT, bat_priv,
2494 				   "TT inconsistency for %pM. Need to retrieve the correct information (ttvn: %u last_ttvn: %u crc: %#.4x last_crc: %#.4x num_changes: %u)\n",
2495 				   orig_node->orig, ttvn, orig_ttvn, tt_crc,
2496 				   orig_node->tt_crc, tt_num_changes);
2497 			batadv_send_tt_request(bat_priv, orig_node, ttvn,
2498 					       tt_crc, full_table);
2499 			return;
2500 		}
2501 	}
2502 }
2503 
2504 /* returns true whether we know that the client has moved from its old
2505  * originator to another one. This entry is kept is still kept for consistency
2506  * purposes
2507  */
2508 bool batadv_tt_global_client_is_roaming(struct batadv_priv *bat_priv,
2509 					uint8_t *addr)
2510 {
2511 	struct batadv_tt_global_entry *tt_global_entry;
2512 	bool ret = false;
2513 
2514 	tt_global_entry = batadv_tt_global_hash_find(bat_priv, addr);
2515 	if (!tt_global_entry)
2516 		goto out;
2517 
2518 	ret = tt_global_entry->common.flags & BATADV_TT_CLIENT_ROAM;
2519 	batadv_tt_global_entry_free_ref(tt_global_entry);
2520 out:
2521 	return ret;
2522 }
2523 
2524 /**
2525  * batadv_tt_local_client_is_roaming - tells whether the client is roaming
2526  * @bat_priv: the bat priv with all the soft interface information
2527  * @addr: the MAC address of the local client to query
2528  *
2529  * Returns true if the local client is known to be roaming (it is not served by
2530  * this node anymore) or not. If yes, the client is still present in the table
2531  * to keep the latter consistent with the node TTVN
2532  */
2533 bool batadv_tt_local_client_is_roaming(struct batadv_priv *bat_priv,
2534 				       uint8_t *addr)
2535 {
2536 	struct batadv_tt_local_entry *tt_local_entry;
2537 	bool ret = false;
2538 
2539 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr);
2540 	if (!tt_local_entry)
2541 		goto out;
2542 
2543 	ret = tt_local_entry->common.flags & BATADV_TT_CLIENT_ROAM;
2544 	batadv_tt_local_entry_free_ref(tt_local_entry);
2545 out:
2546 	return ret;
2547 }
2548 
2549 bool batadv_tt_add_temporary_global_entry(struct batadv_priv *bat_priv,
2550 					  struct batadv_orig_node *orig_node,
2551 					  const unsigned char *addr)
2552 {
2553 	bool ret = false;
2554 
2555 	/* if the originator is a backbone node (meaning it belongs to the same
2556 	 * LAN of this node) the temporary client must not be added because to
2557 	 * reach such destination the node must use the LAN instead of the mesh
2558 	 */
2559 	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig))
2560 		goto out;
2561 
2562 	if (!batadv_tt_global_add(bat_priv, orig_node, addr,
2563 				  BATADV_TT_CLIENT_TEMP,
2564 				  atomic_read(&orig_node->last_ttvn)))
2565 		goto out;
2566 
2567 	batadv_dbg(BATADV_DBG_TT, bat_priv,
2568 		   "Added temporary global client (addr: %pM orig: %pM)\n",
2569 		   addr, orig_node->orig);
2570 	ret = true;
2571 out:
2572 	return ret;
2573 }
2574