1	// SPDX-License-Identifier: GPL-2.0
2	/* Copyright (C) B.A.T.M.A.N. contributors:
3	*
4	* Simon Wunderlich
5	*/
6
7	#include "bridge_loop_avoidance.h"
8	#include "main.h"
9
10	#include <linux/atomic.h>
11	#include <linux/byteorder/generic.h>
12	#include <linux/compiler.h>
13	#include <linux/container_of.h>
14	#include <linux/crc16.h>
15	#include <linux/errno.h>
16	#include <linux/etherdevice.h>
17	#include <linux/gfp.h>
18	#include <linux/if_arp.h>
19	#include <linux/if_ether.h>
20	#include <linux/if_vlan.h>
21	#include <linux/jhash.h>
22	#include <linux/jiffies.h>
23	#include <linux/kernel.h>
24	#include <linux/kref.h>
25	#include <linux/list.h>
26	#include <linux/lockdep.h>
27	#include <linux/netdevice.h>
28	#include <linux/netlink.h>
29	#include <linux/rculist.h>
30	#include <linux/rcupdate.h>
31	#include <linux/skbuff.h>
32	#include <linux/slab.h>
33	#include <linux/spinlock.h>
34	#include <linux/stddef.h>
35	#include <linux/string.h>
36	#include <linux/workqueue.h>
37	#include <net/arp.h>
38	#include <net/genetlink.h>
39	#include <net/netlink.h>
40	#include <net/sock.h>
41	#include <uapi/linux/batadv_packet.h>
42	#include <uapi/linux/batman_adv.h>
43
44	#include "hard-interface.h"
45	#include "hash.h"
46	#include "log.h"
47	#include "netlink.h"
48	#include "originator.h"
49	#include "soft-interface.h"
50	#include "translation-table.h"
51
52	static const u8 batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
53
54	static void batadv_bla_periodic_work(struct work_struct *work);
55	static void
56	batadv_bla_send_announce(struct batadv_priv *bat_priv,
57	struct batadv_bla_backbone_gw *backbone_gw);
58
59	/**
60	* batadv_choose_claim() - choose the right bucket for a claim.
61	* @data: data to hash
62	* @size: size of the hash table
63	*
64	* Return: the hash index of the claim
65	*/
66	static inline u32 batadv_choose_claim(const void *data, u32 size)
67	{
68	const struct batadv_bla_claim *claim = data;
69	u32 hash = 0;
70
71	hash = jhash(key: &claim->addr, length: sizeof(claim->addr), initval: hash);
72	hash = jhash(key: &claim->vid, length: sizeof(claim->vid), initval: hash);
73
74	return hash % size;
75	}
76
77	/**
78	* batadv_choose_backbone_gw() - choose the right bucket for a backbone gateway.
79	* @data: data to hash
80	* @size: size of the hash table
81	*
82	* Return: the hash index of the backbone gateway
83	*/
84	static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
85	{
86	const struct batadv_bla_backbone_gw *gw;
87	u32 hash = 0;
88
89	gw = data;
90	hash = jhash(key: &gw->orig, length: sizeof(gw->orig), initval: hash);
91	hash = jhash(key: &gw->vid, length: sizeof(gw->vid), initval: hash);
92
93	return hash % size;
94	}
95
96	/**
97	* batadv_compare_backbone_gw() - compare address and vid of two backbone gws
98	* @node: list node of the first entry to compare
99	* @data2: pointer to the second backbone gateway
100	*
101	* Return: true if the backbones have the same data, false otherwise
102	*/
103	static bool batadv_compare_backbone_gw(const struct hlist_node *node,
104	const void *data2)
105	{
106	const void *data1 = container_of(node, struct batadv_bla_backbone_gw,
107	hash_entry);
108	const struct batadv_bla_backbone_gw *gw1 = data1;
109	const struct batadv_bla_backbone_gw *gw2 = data2;
110
111	if (!batadv_compare_eth(data1: gw1->orig, data2: gw2->orig))
112	return false;
113
114	if (gw1->vid != gw2->vid)
115	return false;
116
117	return true;
118	}
119
120	/**
121	* batadv_compare_claim() - compare address and vid of two claims
122	* @node: list node of the first entry to compare
123	* @data2: pointer to the second claims
124	*
125	* Return: true if the claim have the same data, 0 otherwise
126	*/
127	static bool batadv_compare_claim(const struct hlist_node *node,
128	const void *data2)
129	{
130	const void *data1 = container_of(node, struct batadv_bla_claim,
131	hash_entry);
132	const struct batadv_bla_claim *cl1 = data1;
133	const struct batadv_bla_claim *cl2 = data2;
134
135	if (!batadv_compare_eth(data1: cl1->addr, data2: cl2->addr))
136	return false;
137
138	if (cl1->vid != cl2->vid)
139	return false;
140
141	return true;
142	}
143
144	/**
145	* batadv_backbone_gw_release() - release backbone gw from lists and queue for
146	* free after rcu grace period
147	* @ref: kref pointer of the backbone gw
148	*/
149	static void batadv_backbone_gw_release(struct kref *ref)
150	{
151	struct batadv_bla_backbone_gw *backbone_gw;
152
153	backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,
154	refcount);
155
156	kfree_rcu(backbone_gw, rcu);
157	}
158
159	/**
160	* batadv_backbone_gw_put() - decrement the backbone gw refcounter and possibly
161	* release it
162	* @backbone_gw: backbone gateway to be free'd
163	*/
164	static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw)
165	{
166	if (!backbone_gw)
167	return;
168
169	kref_put(kref: &backbone_gw->refcount, release: batadv_backbone_gw_release);
170	}
171
172	/**
173	* batadv_claim_release() - release claim from lists and queue for free after
174	* rcu grace period
175	* @ref: kref pointer of the claim
176	*/
177	static void batadv_claim_release(struct kref *ref)
178	{
179	struct batadv_bla_claim *claim;
180	struct batadv_bla_backbone_gw *old_backbone_gw;
181
182	claim = container_of(ref, struct batadv_bla_claim, refcount);
183
184	spin_lock_bh(lock: &claim->backbone_lock);
185	old_backbone_gw = claim->backbone_gw;
186	claim->backbone_gw = NULL;
187	spin_unlock_bh(lock: &claim->backbone_lock);
188
189	spin_lock_bh(lock: &old_backbone_gw->crc_lock);
190	old_backbone_gw->crc ^= crc16(crc: 0, buffer: claim->addr, ETH_ALEN);
191	spin_unlock_bh(lock: &old_backbone_gw->crc_lock);
192
193	batadv_backbone_gw_put(backbone_gw: old_backbone_gw);
194
195	kfree_rcu(claim, rcu);
196	}
197
198	/**
199	* batadv_claim_put() - decrement the claim refcounter and possibly release it
200	* @claim: claim to be free'd
201	*/
202	static void batadv_claim_put(struct batadv_bla_claim *claim)
203	{
204	if (!claim)
205	return;
206
207	kref_put(kref: &claim->refcount, release: batadv_claim_release);
208	}
209
210	/**
211	* batadv_claim_hash_find() - looks for a claim in the claim hash
212	* @bat_priv: the bat priv with all the soft interface information
213	* @data: search data (may be local/static data)
214	*
215	* Return: claim if found or NULL otherwise.
216	*/
217	static struct batadv_bla_claim *
218	batadv_claim_hash_find(struct batadv_priv *bat_priv,
219	struct batadv_bla_claim *data)
220	{
221	struct batadv_hashtable *hash = bat_priv->bla.claim_hash;
222	struct hlist_head *head;
223	struct batadv_bla_claim *claim;
224	struct batadv_bla_claim *claim_tmp = NULL;
225	int index;
226
227	if (!hash)
228	return NULL;
229
230	index = batadv_choose_claim(data, size: hash->size);
231	head = &hash->table[index];
232
233	rcu_read_lock();
234	hlist_for_each_entry_rcu(claim, head, hash_entry) {
235	if (!batadv_compare_claim(node: &claim->hash_entry, data2: data))
236	continue;
237
238	if (!kref_get_unless_zero(kref: &claim->refcount))
239	continue;
240
241	claim_tmp = claim;
242	break;
243	}
244	rcu_read_unlock();
245
246	return claim_tmp;
247	}
248
249	/**
250	* batadv_backbone_hash_find() - looks for a backbone gateway in the hash
251	* @bat_priv: the bat priv with all the soft interface information
252	* @addr: the address of the originator
253	* @vid: the VLAN ID
254	*
255	* Return: backbone gateway if found or NULL otherwise
256	*/
257	static struct batadv_bla_backbone_gw *
258	batadv_backbone_hash_find(struct batadv_priv *bat_priv, const u8 *addr,
259	unsigned short vid)
260	{
261	struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
262	struct hlist_head *head;
263	struct batadv_bla_backbone_gw search_entry, *backbone_gw;
264	struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL;
265	int index;
266
267	if (!hash)
268	return NULL;
269
270	ether_addr_copy(dst: search_entry.orig, src: addr);
271	search_entry.vid = vid;
272
273	index = batadv_choose_backbone_gw(data: &search_entry, size: hash->size);
274	head = &hash->table[index];
275
276	rcu_read_lock();
277	hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
278	if (!batadv_compare_backbone_gw(node: &backbone_gw->hash_entry,
279	data2: &search_entry))
280	continue;
281
282	if (!kref_get_unless_zero(kref: &backbone_gw->refcount))
283	continue;
284
285	backbone_gw_tmp = backbone_gw;
286	break;
287	}
288	rcu_read_unlock();
289
290	return backbone_gw_tmp;
291	}
292
293	/**
294	* batadv_bla_del_backbone_claims() - delete all claims for a backbone
295	* @backbone_gw: backbone gateway where the claims should be removed
296	*/
297	static void
298	batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw)
299	{
300	struct batadv_hashtable *hash;
301	struct hlist_node *node_tmp;
302	struct hlist_head *head;
303	struct batadv_bla_claim *claim;
304	int i;
305	spinlock_t *list_lock; /* protects write access to the hash lists */
306
307	hash = backbone_gw->bat_priv->bla.claim_hash;
308	if (!hash)
309	return;
310
311	for (i = 0; i < hash->size; i++) {
312	head = &hash->table[i];
313	list_lock = &hash->list_locks[i];
314
315	spin_lock_bh(lock: list_lock);
316	hlist_for_each_entry_safe(claim, node_tmp,
317	head, hash_entry) {
318	if (claim->backbone_gw != backbone_gw)
319	continue;
320
321	batadv_claim_put(claim);
322	hlist_del_rcu(n: &claim->hash_entry);
323	}
324	spin_unlock_bh(lock: list_lock);
325	}
326
327	/* all claims gone, initialize CRC */
328	spin_lock_bh(lock: &backbone_gw->crc_lock);
329	backbone_gw->crc = BATADV_BLA_CRC_INIT;
330	spin_unlock_bh(lock: &backbone_gw->crc_lock);
331	}
332
333	/**
334	* batadv_bla_send_claim() - sends a claim frame according to the provided info
335	* @bat_priv: the bat priv with all the soft interface information
336	* @mac: the mac address to be announced within the claim
337	* @vid: the VLAN ID
338	* @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
339	*/
340	static void batadv_bla_send_claim(struct batadv_priv *bat_priv, const u8 *mac,
341	unsigned short vid, int claimtype)
342	{
343	struct sk_buff *skb;
344	struct ethhdr *ethhdr;
345	struct batadv_hard_iface *primary_if;
346	struct net_device *soft_iface;
347	u8 *hw_src;
348	struct batadv_bla_claim_dst local_claim_dest;
349	__be32 zeroip = 0;
350
351	primary_if = batadv_primary_if_get_selected(bat_priv);
352	if (!primary_if)
353	return;
354
355	memcpy(&local_claim_dest, &bat_priv->bla.claim_dest,
356	sizeof(local_claim_dest));
357	local_claim_dest.type = claimtype;
358
359	soft_iface = primary_if->soft_iface;
360
361	skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
362	/* IP DST: 0.0.0.0 */
363	dest_ip: zeroip,
364	dev: primary_if->soft_iface,
365	/* IP SRC: 0.0.0.0 */
366	src_ip: zeroip,
367	/* Ethernet DST: Broadcast */
368	NULL,
369	/* Ethernet SRC/HW SRC: originator mac */
370	src_hw: primary_if->net_dev->dev_addr,
371	/* HW DST: FF:43:05:XX:YY:YY
372	* with XX = claim type
373	* and YY:YY = group id
374	*/
375	target_hw: (u8 *)&local_claim_dest);
376
377	if (!skb)
378	goto out;
379
380	ethhdr = (struct ethhdr *)skb->data;
381	hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr);
382
383	/* now we pretend that the client would have sent this ... */
384	switch (claimtype) {
385	case BATADV_CLAIM_TYPE_CLAIM:
386	/* normal claim frame
387	* set Ethernet SRC to the clients mac
388	*/
389	ether_addr_copy(dst: ethhdr->h_source, src: mac);
390	batadv_dbg(BATADV_DBG_BLA, bat_priv,
391	"%s(): CLAIM %pM on vid %d\n", __func__, mac,
392	batadv_print_vid(vid));
393	break;
394	case BATADV_CLAIM_TYPE_UNCLAIM:
395	/* unclaim frame
396	* set HW SRC to the clients mac
397	*/
398	ether_addr_copy(dst: hw_src, src: mac);
399	batadv_dbg(BATADV_DBG_BLA, bat_priv,
400	"%s(): UNCLAIM %pM on vid %d\n", __func__, mac,
401	batadv_print_vid(vid));
402	break;
403	case BATADV_CLAIM_TYPE_ANNOUNCE:
404	/* announcement frame
405	* set HW SRC to the special mac containing the crc
406	*/
407	ether_addr_copy(dst: hw_src, src: mac);
408	batadv_dbg(BATADV_DBG_BLA, bat_priv,
409	"%s(): ANNOUNCE of %pM on vid %d\n", __func__,
410	ethhdr->h_source, batadv_print_vid(vid));
411	break;
412	case BATADV_CLAIM_TYPE_REQUEST:
413	/* request frame
414	* set HW SRC and header destination to the receiving backbone
415	* gws mac
416	*/
417	ether_addr_copy(dst: hw_src, src: mac);
418	ether_addr_copy(dst: ethhdr->h_dest, src: mac);
419	batadv_dbg(BATADV_DBG_BLA, bat_priv,
420	"%s(): REQUEST of %pM to %pM on vid %d\n", __func__,
421	ethhdr->h_source, ethhdr->h_dest,
422	batadv_print_vid(vid));
423	break;
424	case BATADV_CLAIM_TYPE_LOOPDETECT:
425	ether_addr_copy(dst: ethhdr->h_source, src: mac);
426	batadv_dbg(BATADV_DBG_BLA, bat_priv,
427	"%s(): LOOPDETECT of %pM to %pM on vid %d\n",
428	__func__, ethhdr->h_source, ethhdr->h_dest,
429	batadv_print_vid(vid));
430
431	break;
432	}
433
434	if (vid & BATADV_VLAN_HAS_TAG) {
435	skb = vlan_insert_tag(skb, htons(ETH_P_8021Q),
436	vlan_tci: vid & VLAN_VID_MASK);
437	if (!skb)
438	goto out;
439	}
440
441	skb_reset_mac_header(skb);
442	skb->protocol = eth_type_trans(skb, dev: soft_iface);
443	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
444	batadv_add_counter(bat_priv, idx: BATADV_CNT_RX_BYTES,
445	count: skb->len + ETH_HLEN);
446
447	netif_rx(skb);
448	out:
449	batadv_hardif_put(hard_iface: primary_if);
450	}
451
452	/**
453	* batadv_bla_loopdetect_report() - worker for reporting the loop
454	* @work: work queue item
455	*
456	* Throws an uevent, as the loopdetect check function can't do that itself
457	* since the kernel may sleep while throwing uevents.
458	*/
459	static void batadv_bla_loopdetect_report(struct work_struct *work)
460	{
461	struct batadv_bla_backbone_gw *backbone_gw;
462	struct batadv_priv *bat_priv;
463	char vid_str[6] = { '\0' };
464
465	backbone_gw = container_of(work, struct batadv_bla_backbone_gw,
466	report_work);
467	bat_priv = backbone_gw->bat_priv;
468
469	batadv_info(bat_priv->soft_iface,
470	"Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n",
471	batadv_print_vid(backbone_gw->vid));
472	snprintf(buf: vid_str, size: sizeof(vid_str), fmt: "%d",
473	batadv_print_vid(vid: backbone_gw->vid));
474	vid_str[sizeof(vid_str) - 1] = 0;
475
476	batadv_throw_uevent(bat_priv, type: BATADV_UEV_BLA, action: BATADV_UEV_LOOPDETECT,
477	data: vid_str);
478
479	batadv_backbone_gw_put(backbone_gw);
480	}
481
482	/**
483	* batadv_bla_get_backbone_gw() - finds or creates a backbone gateway
484	* @bat_priv: the bat priv with all the soft interface information
485	* @orig: the mac address of the originator
486	* @vid: the VLAN ID
487	* @own_backbone: set if the requested backbone is local
488	*
489	* Return: the (possibly created) backbone gateway or NULL on error
490	*/
491	static struct batadv_bla_backbone_gw *
492	batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig,
493	unsigned short vid, bool own_backbone)
494	{
495	struct batadv_bla_backbone_gw *entry;
496	struct batadv_orig_node *orig_node;
497	int hash_added;
498
499	entry = batadv_backbone_hash_find(bat_priv, addr: orig, vid);
500
501	if (entry)
502	return entry;
503
504	batadv_dbg(BATADV_DBG_BLA, bat_priv,
505	"%s(): not found (%pM, %d), creating new entry\n", __func__,
506	orig, batadv_print_vid(vid));
507
508	entry = kzalloc(size: sizeof(*entry), GFP_ATOMIC);
509	if (!entry)
510	return NULL;
511
512	entry->vid = vid;
513	entry->lasttime = jiffies;
514	entry->crc = BATADV_BLA_CRC_INIT;
515	entry->bat_priv = bat_priv;
516	spin_lock_init(&entry->crc_lock);
517	atomic_set(v: &entry->request_sent, i: 0);
518	atomic_set(v: &entry->wait_periods, i: 0);
519	ether_addr_copy(dst: entry->orig, src: orig);
520	INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report);
521	kref_init(kref: &entry->refcount);
522
523	kref_get(kref: &entry->refcount);
524	hash_added = batadv_hash_add(hash: bat_priv->bla.backbone_hash,
525	compare: batadv_compare_backbone_gw,
526	choose: batadv_choose_backbone_gw, data: entry,
527	data_node: &entry->hash_entry);
528
529	if (unlikely(hash_added != 0)) {
530	/* hash failed, free the structure */
531	kfree(objp: entry);
532	return NULL;
533	}
534
535	/* this is a gateway now, remove any TT entry on this VLAN */
536	orig_node = batadv_orig_hash_find(bat_priv, data: orig);
537	if (orig_node) {
538	batadv_tt_global_del_orig(bat_priv, orig_node, match_vid: vid,
539	message: "became a backbone gateway");
540	batadv_orig_node_put(orig_node);
541	}
542
543	if (own_backbone) {
544	batadv_bla_send_announce(bat_priv, backbone_gw: entry);
545
546	/* this will be decreased in the worker thread */
547	atomic_inc(v: &entry->request_sent);
548	atomic_set(v: &entry->wait_periods, BATADV_BLA_WAIT_PERIODS);
549	atomic_inc(v: &bat_priv->bla.num_requests);
550	}
551
552	return entry;
553	}
554
555	/**
556	* batadv_bla_update_own_backbone_gw() - updates the own backbone gw for a VLAN
557	* @bat_priv: the bat priv with all the soft interface information
558	* @primary_if: the selected primary interface
559	* @vid: VLAN identifier
560	*
561	* update or add the own backbone gw to make sure we announce
562	* where we receive other backbone gws
563	*/
564	static void
565	batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv,
566	struct batadv_hard_iface *primary_if,
567	unsigned short vid)
568	{
569	struct batadv_bla_backbone_gw *backbone_gw;
570
571	backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
572	orig: primary_if->net_dev->dev_addr,
573	vid, own_backbone: true);
574	if (unlikely(!backbone_gw))
575	return;
576
577	backbone_gw->lasttime = jiffies;
578	batadv_backbone_gw_put(backbone_gw);
579	}
580
581	/**
582	* batadv_bla_answer_request() - answer a bla request by sending own claims
583	* @bat_priv: the bat priv with all the soft interface information
584	* @primary_if: interface where the request came on
585	* @vid: the vid where the request came on
586	*
587	* Repeat all of our own claims, and finally send an ANNOUNCE frame
588	* to allow the requester another check if the CRC is correct now.
589	*/
590	static void batadv_bla_answer_request(struct batadv_priv *bat_priv,
591	struct batadv_hard_iface *primary_if,
592	unsigned short vid)
593	{
594	struct hlist_head *head;
595	struct batadv_hashtable *hash;
596	struct batadv_bla_claim *claim;
597	struct batadv_bla_backbone_gw *backbone_gw;
598	int i;
599
600	batadv_dbg(BATADV_DBG_BLA, bat_priv,
601	"%s(): received a claim request, send all of our own claims again\n",
602	__func__);
603
604	backbone_gw = batadv_backbone_hash_find(bat_priv,
605	addr: primary_if->net_dev->dev_addr,
606	vid);
607	if (!backbone_gw)
608	return;
609
610	hash = bat_priv->bla.claim_hash;
611	for (i = 0; i < hash->size; i++) {
612	head = &hash->table[i];
613
614	rcu_read_lock();
615	hlist_for_each_entry_rcu(claim, head, hash_entry) {
616	/* only own claims are interesting */
617	if (claim->backbone_gw != backbone_gw)
618	continue;
619
620	batadv_bla_send_claim(bat_priv, mac: claim->addr, vid: claim->vid,
621	claimtype: BATADV_CLAIM_TYPE_CLAIM);
622	}
623	rcu_read_unlock();
624	}
625
626	/* finally, send an announcement frame */
627	batadv_bla_send_announce(bat_priv, backbone_gw);
628	batadv_backbone_gw_put(backbone_gw);
629	}
630
631	/**
632	* batadv_bla_send_request() - send a request to repeat claims
633	* @backbone_gw: the backbone gateway from whom we are out of sync
634	*
635	* When the crc is wrong, ask the backbone gateway for a full table update.
636	* After the request, it will repeat all of his own claims and finally
637	* send an announcement claim with which we can check again.
638	*/
639	static void batadv_bla_send_request(struct batadv_bla_backbone_gw *backbone_gw)
640	{
641	/* first, remove all old entries */
642	batadv_bla_del_backbone_claims(backbone_gw);
643
644	batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
645	"Sending REQUEST to %pM\n", backbone_gw->orig);
646
647	/* send request */
648	batadv_bla_send_claim(bat_priv: backbone_gw->bat_priv, mac: backbone_gw->orig,
649	vid: backbone_gw->vid, claimtype: BATADV_CLAIM_TYPE_REQUEST);
650
651	/* no local broadcasts should be sent or received, for now. */
652	if (!atomic_read(v: &backbone_gw->request_sent)) {
653	atomic_inc(v: &backbone_gw->bat_priv->bla.num_requests);
654	atomic_set(v: &backbone_gw->request_sent, i: 1);
655	}
656	}
657
658	/**
659	* batadv_bla_send_announce() - Send an announcement frame
660	* @bat_priv: the bat priv with all the soft interface information
661	* @backbone_gw: our backbone gateway which should be announced
662	*/
663	static void batadv_bla_send_announce(struct batadv_priv *bat_priv,
664	struct batadv_bla_backbone_gw *backbone_gw)
665	{
666	u8 mac[ETH_ALEN];
667	__be16 crc;
668
669	memcpy(mac, batadv_announce_mac, 4);
670	spin_lock_bh(lock: &backbone_gw->crc_lock);
671	crc = htons(backbone_gw->crc);
672	spin_unlock_bh(lock: &backbone_gw->crc_lock);
673	memcpy(&mac[4], &crc, 2);
674
675	batadv_bla_send_claim(bat_priv, mac, vid: backbone_gw->vid,
676	claimtype: BATADV_CLAIM_TYPE_ANNOUNCE);
677	}
678
679	/**
680	* batadv_bla_add_claim() - Adds a claim in the claim hash
681	* @bat_priv: the bat priv with all the soft interface information
682	* @mac: the mac address of the claim
683	* @vid: the VLAN ID of the frame
684	* @backbone_gw: the backbone gateway which claims it
685	*/
686	static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
687	const u8 *mac, const unsigned short vid,
688	struct batadv_bla_backbone_gw *backbone_gw)
689	{
690	struct batadv_bla_backbone_gw *old_backbone_gw;
691	struct batadv_bla_claim *claim;
692	struct batadv_bla_claim search_claim;
693	bool remove_crc = false;
694	int hash_added;
695
696	ether_addr_copy(dst: search_claim.addr, src: mac);
697	search_claim.vid = vid;
698	claim = batadv_claim_hash_find(bat_priv, data: &search_claim);
699
700	/* create a new claim entry if it does not exist yet. */
701	if (!claim) {
702	claim = kzalloc(size: sizeof(*claim), GFP_ATOMIC);
703	if (!claim)
704	return;
705
706	ether_addr_copy(dst: claim->addr, src: mac);
707	spin_lock_init(&claim->backbone_lock);
708	claim->vid = vid;
709	claim->lasttime = jiffies;
710	kref_get(kref: &backbone_gw->refcount);
711	claim->backbone_gw = backbone_gw;
712	kref_init(kref: &claim->refcount);
713
714	batadv_dbg(BATADV_DBG_BLA, bat_priv,
715	"%s(): adding new entry %pM, vid %d to hash ...\n",
716	__func__, mac, batadv_print_vid(vid));
717
718	kref_get(kref: &claim->refcount);
719	hash_added = batadv_hash_add(hash: bat_priv->bla.claim_hash,
720	compare: batadv_compare_claim,
721	choose: batadv_choose_claim, data: claim,
722	data_node: &claim->hash_entry);
723
724	if (unlikely(hash_added != 0)) {
725	/* only local changes happened. */
726	kfree(objp: claim);
727	return;
728	}
729	} else {
730	claim->lasttime = jiffies;
731	if (claim->backbone_gw == backbone_gw)
732	/* no need to register a new backbone */
733	goto claim_free_ref;
734
735	batadv_dbg(BATADV_DBG_BLA, bat_priv,
736	"%s(): changing ownership for %pM, vid %d to gw %pM\n",
737	__func__, mac, batadv_print_vid(vid),
738	backbone_gw->orig);
739
740	remove_crc = true;
741	}
742
743	/* replace backbone_gw atomically and adjust reference counters */
744	spin_lock_bh(lock: &claim->backbone_lock);
745	old_backbone_gw = claim->backbone_gw;
746	kref_get(kref: &backbone_gw->refcount);
747	claim->backbone_gw = backbone_gw;
748	spin_unlock_bh(lock: &claim->backbone_lock);
749
750	if (remove_crc) {
751	/* remove claim address from old backbone_gw */
752	spin_lock_bh(lock: &old_backbone_gw->crc_lock);
753	old_backbone_gw->crc ^= crc16(crc: 0, buffer: claim->addr, ETH_ALEN);
754	spin_unlock_bh(lock: &old_backbone_gw->crc_lock);
755	}
756
757	batadv_backbone_gw_put(backbone_gw: old_backbone_gw);
758
759	/* add claim address to new backbone_gw */
760	spin_lock_bh(lock: &backbone_gw->crc_lock);
761	backbone_gw->crc ^= crc16(crc: 0, buffer: claim->addr, ETH_ALEN);
762	spin_unlock_bh(lock: &backbone_gw->crc_lock);
763	backbone_gw->lasttime = jiffies;
764
765	claim_free_ref:
766	batadv_claim_put(claim);
767	}
768
769	/**
770	* batadv_bla_claim_get_backbone_gw() - Get valid reference for backbone_gw of
771	* claim
772	* @claim: claim whose backbone_gw should be returned
773	*
774	* Return: valid reference to claim::backbone_gw
775	*/
776	static struct batadv_bla_backbone_gw *
777	batadv_bla_claim_get_backbone_gw(struct batadv_bla_claim *claim)
778	{
779	struct batadv_bla_backbone_gw *backbone_gw;
780
781	spin_lock_bh(lock: &claim->backbone_lock);
782	backbone_gw = claim->backbone_gw;
783	kref_get(kref: &backbone_gw->refcount);
784	spin_unlock_bh(lock: &claim->backbone_lock);
785
786	return backbone_gw;
787	}
788
789	/**
790	* batadv_bla_del_claim() - delete a claim from the claim hash
791	* @bat_priv: the bat priv with all the soft interface information
792	* @mac: mac address of the claim to be removed
793	* @vid: VLAN id for the claim to be removed
794	*/
795	static void batadv_bla_del_claim(struct batadv_priv *bat_priv,
796	const u8 *mac, const unsigned short vid)
797	{
798	struct batadv_bla_claim search_claim, *claim;
799	struct batadv_bla_claim *claim_removed_entry;
800	struct hlist_node *claim_removed_node;
801
802	ether_addr_copy(dst: search_claim.addr, src: mac);
803	search_claim.vid = vid;
804	claim = batadv_claim_hash_find(bat_priv, data: &search_claim);
805	if (!claim)
806	return;
807
808	batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__,
809	mac, batadv_print_vid(vid));
810
811	claim_removed_node = batadv_hash_remove(hash: bat_priv->bla.claim_hash,
812	compare: batadv_compare_claim,
813	choose: batadv_choose_claim, data: claim);
814	if (!claim_removed_node)
815	goto free_claim;
816
817	/* reference from the hash is gone */
818	claim_removed_entry = hlist_entry(claim_removed_node,
819	struct batadv_bla_claim, hash_entry);
820	batadv_claim_put(claim: claim_removed_entry);
821
822	free_claim:
823	/* don't need the reference from hash_find() anymore */
824	batadv_claim_put(claim);
825	}
826
827	/**
828	* batadv_handle_announce() - check for ANNOUNCE frame
829	* @bat_priv: the bat priv with all the soft interface information
830	* @an_addr: announcement mac address (ARP Sender HW address)
831	* @backbone_addr: originator address of the sender (Ethernet source MAC)
832	* @vid: the VLAN ID of the frame
833	*
834	* Return: true if handled
835	*/
836	static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr,
837	u8 *backbone_addr, unsigned short vid)
838	{
839	struct batadv_bla_backbone_gw *backbone_gw;
840	u16 backbone_crc, crc;
841
842	if (memcmp(p: an_addr, q: batadv_announce_mac, size: 4) != 0)
843	return false;
844
845	backbone_gw = batadv_bla_get_backbone_gw(bat_priv, orig: backbone_addr, vid,
846	own_backbone: false);
847
848	if (unlikely(!backbone_gw))
849	return true;
850
851	/* handle as ANNOUNCE frame */
852	backbone_gw->lasttime = jiffies;
853	crc = ntohs(*((__force __be16 *)(&an_addr[4])));
854
855	batadv_dbg(BATADV_DBG_BLA, bat_priv,
856	"%s(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n",
857	__func__, batadv_print_vid(vid), backbone_gw->orig, crc);
858
859	spin_lock_bh(lock: &backbone_gw->crc_lock);
860	backbone_crc = backbone_gw->crc;
861	spin_unlock_bh(lock: &backbone_gw->crc_lock);
862
863	if (backbone_crc != crc) {
864	batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
865	"%s(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n",
866	__func__, backbone_gw->orig,
867	batadv_print_vid(backbone_gw->vid),
868	backbone_crc, crc);
869
870	batadv_bla_send_request(backbone_gw);
871	} else {
872	/* if we have sent a request and the crc was OK,
873	* we can allow traffic again.
874	*/
875	if (atomic_read(v: &backbone_gw->request_sent)) {
876	atomic_dec(v: &backbone_gw->bat_priv->bla.num_requests);
877	atomic_set(v: &backbone_gw->request_sent, i: 0);
878	}
879	}
880
881	batadv_backbone_gw_put(backbone_gw);
882	return true;
883	}
884
885	/**
886	* batadv_handle_request() - check for REQUEST frame
887	* @bat_priv: the bat priv with all the soft interface information
888	* @primary_if: the primary hard interface of this batman soft interface
889	* @backbone_addr: backbone address to be requested (ARP sender HW MAC)
890	* @ethhdr: ethernet header of a packet
891	* @vid: the VLAN ID of the frame
892	*
893	* Return: true if handled
894	*/
895	static bool batadv_handle_request(struct batadv_priv *bat_priv,
896	struct batadv_hard_iface *primary_if,
897	u8 *backbone_addr, struct ethhdr *ethhdr,
898	unsigned short vid)
899	{
900	/* check for REQUEST frame */
901	if (!batadv_compare_eth(data1: backbone_addr, data2: ethhdr->h_dest))
902	return false;
903
904	/* sanity check, this should not happen on a normal switch,
905	* we ignore it in this case.
906	*/
907	if (!batadv_compare_eth(data1: ethhdr->h_dest, data2: primary_if->net_dev->dev_addr))
908	return true;
909
910	batadv_dbg(BATADV_DBG_BLA, bat_priv,
911	"%s(): REQUEST vid %d (sent by %pM)...\n",
912	__func__, batadv_print_vid(vid), ethhdr->h_source);
913
914	batadv_bla_answer_request(bat_priv, primary_if, vid);
915	return true;
916	}
917
918	/**
919	* batadv_handle_unclaim() - check for UNCLAIM frame
920	* @bat_priv: the bat priv with all the soft interface information
921	* @primary_if: the primary hard interface of this batman soft interface
922	* @backbone_addr: originator address of the backbone (Ethernet source)
923	* @claim_addr: Client to be unclaimed (ARP sender HW MAC)
924	* @vid: the VLAN ID of the frame
925	*
926	* Return: true if handled
927	*/
928	static bool batadv_handle_unclaim(struct batadv_priv *bat_priv,
929	struct batadv_hard_iface *primary_if,
930	const u8 *backbone_addr, const u8 *claim_addr,
931	unsigned short vid)
932	{
933	struct batadv_bla_backbone_gw *backbone_gw;
934
935	/* unclaim in any case if it is our own */
936	if (primary_if && batadv_compare_eth(data1: backbone_addr,
937	data2: primary_if->net_dev->dev_addr))
938	batadv_bla_send_claim(bat_priv, mac: claim_addr, vid,
939	claimtype: BATADV_CLAIM_TYPE_UNCLAIM);
940
941	backbone_gw = batadv_backbone_hash_find(bat_priv, addr: backbone_addr, vid);
942
943	if (!backbone_gw)
944	return true;
945
946	/* this must be an UNCLAIM frame */
947	batadv_dbg(BATADV_DBG_BLA, bat_priv,
948	"%s(): UNCLAIM %pM on vid %d (sent by %pM)...\n", __func__,
949	claim_addr, batadv_print_vid(vid), backbone_gw->orig);
950
951	batadv_bla_del_claim(bat_priv, mac: claim_addr, vid);
952	batadv_backbone_gw_put(backbone_gw);
953	return true;
954	}
955
956	/**
957	* batadv_handle_claim() - check for CLAIM frame
958	* @bat_priv: the bat priv with all the soft interface information
959	* @primary_if: the primary hard interface of this batman soft interface
960	* @backbone_addr: originator address of the backbone (Ethernet Source)
961	* @claim_addr: client mac address to be claimed (ARP sender HW MAC)
962	* @vid: the VLAN ID of the frame
963	*
964	* Return: true if handled
965	*/
966	static bool batadv_handle_claim(struct batadv_priv *bat_priv,
967	struct batadv_hard_iface *primary_if,
968	const u8 *backbone_addr, const u8 *claim_addr,
969	unsigned short vid)
970	{
971	struct batadv_bla_backbone_gw *backbone_gw;
972
973	/* register the gateway if not yet available, and add the claim. */
974
975	backbone_gw = batadv_bla_get_backbone_gw(bat_priv, orig: backbone_addr, vid,
976	own_backbone: false);
977
978	if (unlikely(!backbone_gw))
979	return true;
980
981	/* this must be a CLAIM frame */
982	batadv_bla_add_claim(bat_priv, mac: claim_addr, vid, backbone_gw);
983	if (batadv_compare_eth(data1: backbone_addr, data2: primary_if->net_dev->dev_addr))
984	batadv_bla_send_claim(bat_priv, mac: claim_addr, vid,
985	claimtype: BATADV_CLAIM_TYPE_CLAIM);
986
987	/* TODO: we could call something like tt_local_del() here. */
988
989	batadv_backbone_gw_put(backbone_gw);
990	return true;
991	}
992
993	/**
994	* batadv_check_claim_group() - check for claim group membership
995	* @bat_priv: the bat priv with all the soft interface information
996	* @primary_if: the primary interface of this batman interface
997	* @hw_src: the Hardware source in the ARP Header
998	* @hw_dst: the Hardware destination in the ARP Header
999	* @ethhdr: pointer to the Ethernet header of the claim frame
1000	*
1001	* checks if it is a claim packet and if it's on the same group.
1002	* This function also applies the group ID of the sender
1003	* if it is in the same mesh.
1004	*
1005	* Return:
1006	* 2 - if it is a claim packet and on the same group
1007	* 1 - if is a claim packet from another group
1008	* 0 - if it is not a claim packet
1009	*/
1010	static int batadv_check_claim_group(struct batadv_priv *bat_priv,
1011	struct batadv_hard_iface *primary_if,
1012	u8 *hw_src, u8 *hw_dst,
1013	struct ethhdr *ethhdr)
1014	{
1015	u8 *backbone_addr;
1016	struct batadv_orig_node *orig_node;
1017	struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
1018
1019	bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1020	bla_dst_own = &bat_priv->bla.claim_dest;
1021
1022	/* if announcement packet, use the source,
1023	* otherwise assume it is in the hw_src
1024	*/
1025	switch (bla_dst->type) {
1026	case BATADV_CLAIM_TYPE_CLAIM:
1027	backbone_addr = hw_src;
1028	break;
1029	case BATADV_CLAIM_TYPE_REQUEST:
1030	case BATADV_CLAIM_TYPE_ANNOUNCE:
1031	case BATADV_CLAIM_TYPE_UNCLAIM:
1032	backbone_addr = ethhdr->h_source;
1033	break;
1034	default:
1035	return 0;
1036	}
1037
1038	/* don't accept claim frames from ourselves */
1039	if (batadv_compare_eth(data1: backbone_addr, data2: primary_if->net_dev->dev_addr))
1040	return 0;
1041
1042	/* if its already the same group, it is fine. */
1043	if (bla_dst->group == bla_dst_own->group)
1044	return 2;
1045
1046	/* lets see if this originator is in our mesh */
1047	orig_node = batadv_orig_hash_find(bat_priv, data: backbone_addr);
1048
1049	/* don't accept claims from gateways which are not in
1050	* the same mesh or group.
1051	*/
1052	if (!orig_node)
1053	return 1;
1054
1055	/* if our mesh friends mac is bigger, use it for ourselves. */
1056	if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) {
1057	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1058	"taking other backbones claim group: %#.4x\n",
1059	ntohs(bla_dst->group));
1060	bla_dst_own->group = bla_dst->group;
1061	}
1062
1063	batadv_orig_node_put(orig_node);
1064
1065	return 2;
1066	}
1067
1068	/**
1069	* batadv_bla_process_claim() - Check if this is a claim frame, and process it
1070	* @bat_priv: the bat priv with all the soft interface information
1071	* @primary_if: the primary hard interface of this batman soft interface
1072	* @skb: the frame to be checked
1073	*
1074	* Return: true if it was a claim frame, otherwise return false to
1075	* tell the callee that it can use the frame on its own.
1076	*/
1077	static bool batadv_bla_process_claim(struct batadv_priv *bat_priv,
1078	struct batadv_hard_iface *primary_if,
1079	struct sk_buff *skb)
1080	{
1081	struct batadv_bla_claim_dst *bla_dst, *bla_dst_own;
1082	u8 *hw_src, *hw_dst;
1083	struct vlan_hdr *vhdr, vhdr_buf;
1084	struct ethhdr *ethhdr;
1085	struct arphdr *arphdr;
1086	unsigned short vid;
1087	int vlan_depth = 0;
1088	__be16 proto;
1089	int headlen;
1090	int ret;
1091
1092	vid = batadv_get_vid(skb, header_len: 0);
1093	ethhdr = eth_hdr(skb);
1094
1095	proto = ethhdr->h_proto;
1096	headlen = ETH_HLEN;
1097	if (vid & BATADV_VLAN_HAS_TAG) {
1098	/* Traverse the VLAN/Ethertypes.
1099	*
1100	* At this point it is known that the first protocol is a VLAN
1101	* header, so start checking at the encapsulated protocol.
1102	*
1103	* The depth of the VLAN headers is recorded to drop BLA claim
1104	* frames encapsulated into multiple VLAN headers (QinQ).
1105	*/
1106	do {
1107	vhdr = skb_header_pointer(skb, offset: headlen, VLAN_HLEN,
1108	buffer: &vhdr_buf);
1109	if (!vhdr)
1110	return false;
1111
1112	proto = vhdr->h_vlan_encapsulated_proto;
1113	headlen += VLAN_HLEN;
1114	vlan_depth++;
1115	} while (proto == htons(ETH_P_8021Q));
1116	}
1117
1118	if (proto != htons(ETH_P_ARP))
1119	return false; /* not a claim frame */
1120
1121	/* this must be a ARP frame. check if it is a claim. */
1122
1123	if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
1124	return false;
1125
1126	/* pskb_may_pull() may have modified the pointers, get ethhdr again */
1127	ethhdr = eth_hdr(skb);
1128	arphdr = (struct arphdr *)((u8 *)ethhdr + headlen);
1129
1130	/* Check whether the ARP frame carries a valid
1131	* IP information
1132	*/
1133	if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
1134	return false;
1135	if (arphdr->ar_pro != htons(ETH_P_IP))
1136	return false;
1137	if (arphdr->ar_hln != ETH_ALEN)
1138	return false;
1139	if (arphdr->ar_pln != 4)
1140	return false;
1141
1142	hw_src = (u8 *)arphdr + sizeof(struct arphdr);
1143	hw_dst = hw_src + ETH_ALEN + 4;
1144	bla_dst = (struct batadv_bla_claim_dst *)hw_dst;
1145	bla_dst_own = &bat_priv->bla.claim_dest;
1146
1147	/* check if it is a claim frame in general */
1148	if (memcmp(p: bla_dst->magic, q: bla_dst_own->magic,
1149	size: sizeof(bla_dst->magic)) != 0)
1150	return false;
1151
1152	/* check if there is a claim frame encapsulated deeper in (QinQ) and
1153	* drop that, as this is not supported by BLA but should also not be
1154	* sent via the mesh.
1155	*/
1156	if (vlan_depth > 1)
1157	return true;
1158
1159	/* Let the loopdetect frames on the mesh in any case. */
1160	if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT)
1161	return false;
1162
1163	/* check if it is a claim frame. */
1164	ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst,
1165	ethhdr);
1166	if (ret == 1)
1167	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1168	"%s(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1169	__func__, ethhdr->h_source, batadv_print_vid(vid),
1170	hw_src, hw_dst);
1171
1172	if (ret < 2)
1173	return !!ret;
1174
1175	/* become a backbone gw ourselves on this vlan if not happened yet */
1176	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1177
1178	/* check for the different types of claim frames ... */
1179	switch (bla_dst->type) {
1180	case BATADV_CLAIM_TYPE_CLAIM:
1181	if (batadv_handle_claim(bat_priv, primary_if, backbone_addr: hw_src,
1182	claim_addr: ethhdr->h_source, vid))
1183	return true;
1184	break;
1185	case BATADV_CLAIM_TYPE_UNCLAIM:
1186	if (batadv_handle_unclaim(bat_priv, primary_if,
1187	backbone_addr: ethhdr->h_source, claim_addr: hw_src, vid))
1188	return true;
1189	break;
1190
1191	case BATADV_CLAIM_TYPE_ANNOUNCE:
1192	if (batadv_handle_announce(bat_priv, an_addr: hw_src, backbone_addr: ethhdr->h_source,
1193	vid))
1194	return true;
1195	break;
1196	case BATADV_CLAIM_TYPE_REQUEST:
1197	if (batadv_handle_request(bat_priv, primary_if, backbone_addr: hw_src, ethhdr,
1198	vid))
1199	return true;
1200	break;
1201	}
1202
1203	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1204	"%s(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
1205	__func__, ethhdr->h_source, batadv_print_vid(vid), hw_src,
1206	hw_dst);
1207	return true;
1208	}
1209
1210	/**
1211	* batadv_bla_purge_backbone_gw() - Remove backbone gateways after a timeout or
1212	* immediately
1213	* @bat_priv: the bat priv with all the soft interface information
1214	* @now: whether the whole hash shall be wiped now
1215	*
1216	* Check when we last heard from other nodes, and remove them in case of
1217	* a time out, or clean all backbone gws if now is set.
1218	*/
1219	static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now)
1220	{
1221	struct batadv_bla_backbone_gw *backbone_gw;
1222	struct hlist_node *node_tmp;
1223	struct hlist_head *head;
1224	struct batadv_hashtable *hash;
1225	spinlock_t *list_lock; /* protects write access to the hash lists */
1226	int i;
1227
1228	hash = bat_priv->bla.backbone_hash;
1229	if (!hash)
1230	return;
1231
1232	for (i = 0; i < hash->size; i++) {
1233	head = &hash->table[i];
1234	list_lock = &hash->list_locks[i];
1235
1236	spin_lock_bh(lock: list_lock);
1237	hlist_for_each_entry_safe(backbone_gw, node_tmp,
1238	head, hash_entry) {
1239	if (now)
1240	goto purge_now;
1241	if (!batadv_has_timed_out(timestamp: backbone_gw->lasttime,
1242	BATADV_BLA_BACKBONE_TIMEOUT))
1243	continue;
1244
1245	batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv,
1246	"%s(): backbone gw %pM timed out\n",
1247	__func__, backbone_gw->orig);
1248
1249	purge_now:
1250	/* don't wait for the pending request anymore */
1251	if (atomic_read(v: &backbone_gw->request_sent))
1252	atomic_dec(v: &bat_priv->bla.num_requests);
1253
1254	batadv_bla_del_backbone_claims(backbone_gw);
1255
1256	hlist_del_rcu(n: &backbone_gw->hash_entry);
1257	batadv_backbone_gw_put(backbone_gw);
1258	}
1259	spin_unlock_bh(lock: list_lock);
1260	}
1261	}
1262
1263	/**
1264	* batadv_bla_purge_claims() - Remove claims after a timeout or immediately
1265	* @bat_priv: the bat priv with all the soft interface information
1266	* @primary_if: the selected primary interface, may be NULL if now is set
1267	* @now: whether the whole hash shall be wiped now
1268	*
1269	* Check when we heard last time from our own claims, and remove them in case of
1270	* a time out, or clean all claims if now is set
1271	*/
1272	static void batadv_bla_purge_claims(struct batadv_priv *bat_priv,
1273	struct batadv_hard_iface *primary_if,
1274	int now)
1275	{
1276	struct batadv_bla_backbone_gw *backbone_gw;
1277	struct batadv_bla_claim *claim;
1278	struct hlist_head *head;
1279	struct batadv_hashtable *hash;
1280	int i;
1281
1282	hash = bat_priv->bla.claim_hash;
1283	if (!hash)
1284	return;
1285
1286	for (i = 0; i < hash->size; i++) {
1287	head = &hash->table[i];
1288
1289	rcu_read_lock();
1290	hlist_for_each_entry_rcu(claim, head, hash_entry) {
1291	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
1292	if (now)
1293	goto purge_now;
1294
1295	if (!batadv_compare_eth(data1: backbone_gw->orig,
1296	data2: primary_if->net_dev->dev_addr))
1297	goto skip;
1298
1299	if (!batadv_has_timed_out(timestamp: claim->lasttime,
1300	BATADV_BLA_CLAIM_TIMEOUT))
1301	goto skip;
1302
1303	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1304	"%s(): timed out.\n", __func__);
1305
1306	purge_now:
1307	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1308	"%s(): %pM, vid %d\n", __func__,
1309	claim->addr, claim->vid);
1310
1311	batadv_handle_unclaim(bat_priv, primary_if,
1312	backbone_addr: backbone_gw->orig,
1313	claim_addr: claim->addr, vid: claim->vid);
1314	skip:
1315	batadv_backbone_gw_put(backbone_gw);
1316	}
1317	rcu_read_unlock();
1318	}
1319	}
1320
1321	/**
1322	* batadv_bla_update_orig_address() - Update the backbone gateways when the own
1323	* originator address changes
1324	* @bat_priv: the bat priv with all the soft interface information
1325	* @primary_if: the new selected primary_if
1326	* @oldif: the old primary interface, may be NULL
1327	*/
1328	void batadv_bla_update_orig_address(struct batadv_priv *bat_priv,
1329	struct batadv_hard_iface *primary_if,
1330	struct batadv_hard_iface *oldif)
1331	{
1332	struct batadv_bla_backbone_gw *backbone_gw;
1333	struct hlist_head *head;
1334	struct batadv_hashtable *hash;
1335	__be16 group;
1336	int i;
1337
1338	/* reset bridge loop avoidance group id */
1339	group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN));
1340	bat_priv->bla.claim_dest.group = group;
1341
1342	/* purge everything when bridge loop avoidance is turned off */
1343	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
1344	oldif = NULL;
1345
1346	if (!oldif) {
1347	batadv_bla_purge_claims(bat_priv, NULL, now: 1);
1348	batadv_bla_purge_backbone_gw(bat_priv, now: 1);
1349	return;
1350	}
1351
1352	hash = bat_priv->bla.backbone_hash;
1353	if (!hash)
1354	return;
1355
1356	for (i = 0; i < hash->size; i++) {
1357	head = &hash->table[i];
1358
1359	rcu_read_lock();
1360	hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1361	/* own orig still holds the old value. */
1362	if (!batadv_compare_eth(data1: backbone_gw->orig,
1363	data2: oldif->net_dev->dev_addr))
1364	continue;
1365
1366	ether_addr_copy(dst: backbone_gw->orig,
1367	src: primary_if->net_dev->dev_addr);
1368	/* send an announce frame so others will ask for our
1369	* claims and update their tables.
1370	*/
1371	batadv_bla_send_announce(bat_priv, backbone_gw);
1372	}
1373	rcu_read_unlock();
1374	}
1375	}
1376
1377	/**
1378	* batadv_bla_send_loopdetect() - send a loopdetect frame
1379	* @bat_priv: the bat priv with all the soft interface information
1380	* @backbone_gw: the backbone gateway for which a loop should be detected
1381	*
1382	* To detect loops that the bridge loop avoidance can't handle, send a loop
1383	* detection packet on the backbone. Unlike other BLA frames, this frame will
1384	* be allowed on the mesh by other nodes. If it is received on the mesh, this
1385	* indicates that there is a loop.
1386	*/
1387	static void
1388	batadv_bla_send_loopdetect(struct batadv_priv *bat_priv,
1389	struct batadv_bla_backbone_gw *backbone_gw)
1390	{
1391	batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n",
1392	backbone_gw->vid);
1393	batadv_bla_send_claim(bat_priv, mac: bat_priv->bla.loopdetect_addr,
1394	vid: backbone_gw->vid, claimtype: BATADV_CLAIM_TYPE_LOOPDETECT);
1395	}
1396
1397	/**
1398	* batadv_bla_status_update() - purge bla interfaces if necessary
1399	* @net_dev: the soft interface net device
1400	*/
1401	void batadv_bla_status_update(struct net_device *net_dev)
1402	{
1403	struct batadv_priv *bat_priv = netdev_priv(dev: net_dev);
1404	struct batadv_hard_iface *primary_if;
1405
1406	primary_if = batadv_primary_if_get_selected(bat_priv);
1407	if (!primary_if)
1408	return;
1409
1410	/* this function already purges everything when bla is disabled,
1411	* so just call that one.
1412	*/
1413	batadv_bla_update_orig_address(bat_priv, primary_if, oldif: primary_if);
1414	batadv_hardif_put(hard_iface: primary_if);
1415	}
1416
1417	/**
1418	* batadv_bla_periodic_work() - performs periodic bla work
1419	* @work: kernel work struct
1420	*
1421	* periodic work to do:
1422	* * purge structures when they are too old
1423	* * send announcements
1424	*/
1425	static void batadv_bla_periodic_work(struct work_struct *work)
1426	{
1427	struct delayed_work *delayed_work;
1428	struct batadv_priv *bat_priv;
1429	struct batadv_priv_bla *priv_bla;
1430	struct hlist_head *head;
1431	struct batadv_bla_backbone_gw *backbone_gw;
1432	struct batadv_hashtable *hash;
1433	struct batadv_hard_iface *primary_if;
1434	bool send_loopdetect = false;
1435	int i;
1436
1437	delayed_work = to_delayed_work(work);
1438	priv_bla = container_of(delayed_work, struct batadv_priv_bla, work);
1439	bat_priv = container_of(priv_bla, struct batadv_priv, bla);
1440	primary_if = batadv_primary_if_get_selected(bat_priv);
1441	if (!primary_if)
1442	goto out;
1443
1444	batadv_bla_purge_claims(bat_priv, primary_if, now: 0);
1445	batadv_bla_purge_backbone_gw(bat_priv, now: 0);
1446
1447	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
1448	goto out;
1449
1450	if (atomic_dec_and_test(v: &bat_priv->bla.loopdetect_next)) {
1451	/* set a new random mac address for the next bridge loop
1452	* detection frames. Set the locally administered bit to avoid
1453	* collisions with users mac addresses.
1454	*/
1455	eth_random_addr(addr: bat_priv->bla.loopdetect_addr);
1456	bat_priv->bla.loopdetect_addr[0] = 0xba;
1457	bat_priv->bla.loopdetect_addr[1] = 0xbe;
1458	bat_priv->bla.loopdetect_lasttime = jiffies;
1459	atomic_set(v: &bat_priv->bla.loopdetect_next,
1460	BATADV_BLA_LOOPDETECT_PERIODS);
1461
1462	/* mark for sending loop detect on all VLANs */
1463	send_loopdetect = true;
1464	}
1465
1466	hash = bat_priv->bla.backbone_hash;
1467	if (!hash)
1468	goto out;
1469
1470	for (i = 0; i < hash->size; i++) {
1471	head = &hash->table[i];
1472
1473	rcu_read_lock();
1474	hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1475	if (!batadv_compare_eth(data1: backbone_gw->orig,
1476	data2: primary_if->net_dev->dev_addr))
1477	continue;
1478
1479	backbone_gw->lasttime = jiffies;
1480
1481	batadv_bla_send_announce(bat_priv, backbone_gw);
1482	if (send_loopdetect)
1483	batadv_bla_send_loopdetect(bat_priv,
1484	backbone_gw);
1485
1486	/* request_sent is only set after creation to avoid
1487	* problems when we are not yet known as backbone gw
1488	* in the backbone.
1489	*
1490	* We can reset this now after we waited some periods
1491	* to give bridge forward delays and bla group forming
1492	* some grace time.
1493	*/
1494
1495	if (atomic_read(v: &backbone_gw->request_sent) == 0)
1496	continue;
1497
1498	if (!atomic_dec_and_test(v: &backbone_gw->wait_periods))
1499	continue;
1500
1501	atomic_dec(v: &backbone_gw->bat_priv->bla.num_requests);
1502	atomic_set(v: &backbone_gw->request_sent, i: 0);
1503	}
1504	rcu_read_unlock();
1505	}
1506	out:
1507	batadv_hardif_put(hard_iface: primary_if);
1508
1509	queue_delayed_work(wq: batadv_event_workqueue, dwork: &bat_priv->bla.work,
1510	delay: msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1511	}
1512
1513	/* The hash for claim and backbone hash receive the same key because they
1514	* are getting initialized by hash_new with the same key. Reinitializing
1515	* them with to different keys to allow nested locking without generating
1516	* lockdep warnings
1517	*/
1518	static struct lock_class_key batadv_claim_hash_lock_class_key;
1519	static struct lock_class_key batadv_backbone_hash_lock_class_key;
1520
1521	/**
1522	* batadv_bla_init() - initialize all bla structures
1523	* @bat_priv: the bat priv with all the soft interface information
1524	*
1525	* Return: 0 on success, < 0 on error.
1526	*/
1527	int batadv_bla_init(struct batadv_priv *bat_priv)
1528	{
1529	int i;
1530	u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
1531	struct batadv_hard_iface *primary_if;
1532	u16 crc;
1533	unsigned long entrytime;
1534
1535	spin_lock_init(&bat_priv->bla.bcast_duplist_lock);
1536
1537	batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n");
1538
1539	/* setting claim destination address */
1540	memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3);
1541	bat_priv->bla.claim_dest.type = 0;
1542	primary_if = batadv_primary_if_get_selected(bat_priv);
1543	if (primary_if) {
1544	crc = crc16(crc: 0, buffer: primary_if->net_dev->dev_addr, ETH_ALEN);
1545	bat_priv->bla.claim_dest.group = htons(crc);
1546	batadv_hardif_put(hard_iface: primary_if);
1547	} else {
1548	bat_priv->bla.claim_dest.group = 0; /* will be set later */
1549	}
1550
1551	/* initialize the duplicate list */
1552	entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT);
1553	for (i = 0; i < BATADV_DUPLIST_SIZE; i++)
1554	bat_priv->bla.bcast_duplist[i].entrytime = entrytime;
1555	bat_priv->bla.bcast_duplist_curr = 0;
1556
1557	atomic_set(v: &bat_priv->bla.loopdetect_next,
1558	BATADV_BLA_LOOPDETECT_PERIODS);
1559
1560	if (bat_priv->bla.claim_hash)
1561	return 0;
1562
1563	bat_priv->bla.claim_hash = batadv_hash_new(size: 128);
1564	if (!bat_priv->bla.claim_hash)
1565	return -ENOMEM;
1566
1567	bat_priv->bla.backbone_hash = batadv_hash_new(size: 32);
1568	if (!bat_priv->bla.backbone_hash) {
1569	batadv_hash_destroy(hash: bat_priv->bla.claim_hash);
1570	return -ENOMEM;
1571	}
1572
1573	batadv_hash_set_lock_class(hash: bat_priv->bla.claim_hash,
1574	key: &batadv_claim_hash_lock_class_key);
1575	batadv_hash_set_lock_class(hash: bat_priv->bla.backbone_hash,
1576	key: &batadv_backbone_hash_lock_class_key);
1577
1578	batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n");
1579
1580	INIT_DELAYED_WORK(&bat_priv->bla.work, batadv_bla_periodic_work);
1581
1582	queue_delayed_work(wq: batadv_event_workqueue, dwork: &bat_priv->bla.work,
1583	delay: msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH));
1584	return 0;
1585	}
1586
1587	/**
1588	* batadv_bla_check_duplist() - Check if a frame is in the broadcast dup.
1589	* @bat_priv: the bat priv with all the soft interface information
1590	* @skb: contains the multicast packet to be checked
1591	* @payload_ptr: pointer to position inside the head buffer of the skb
1592	* marking the start of the data to be CRC'ed
1593	* @orig: originator mac address, NULL if unknown
1594	*
1595	* Check if it is on our broadcast list. Another gateway might have sent the
1596	* same packet because it is connected to the same backbone, so we have to
1597	* remove this duplicate.
1598	*
1599	* This is performed by checking the CRC, which will tell us
1600	* with a good chance that it is the same packet. If it is furthermore
1601	* sent by another host, drop it. We allow equal packets from
1602	* the same host however as this might be intended.
1603	*
1604	* Return: true if a packet is in the duplicate list, false otherwise.
1605	*/
1606	static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv,
1607	struct sk_buff *skb, u8 *payload_ptr,
1608	const u8 *orig)
1609	{
1610	struct batadv_bcast_duplist_entry *entry;
1611	bool ret = false;
1612	int i, curr;
1613	__be32 crc;
1614
1615	/* calculate the crc ... */
1616	crc = batadv_skb_crc32(skb, payload_ptr);
1617
1618	spin_lock_bh(lock: &bat_priv->bla.bcast_duplist_lock);
1619
1620	for (i = 0; i < BATADV_DUPLIST_SIZE; i++) {
1621	curr = (bat_priv->bla.bcast_duplist_curr + i);
1622	curr %= BATADV_DUPLIST_SIZE;
1623	entry = &bat_priv->bla.bcast_duplist[curr];
1624
1625	/* we can stop searching if the entry is too old ;
1626	* later entries will be even older
1627	*/
1628	if (batadv_has_timed_out(timestamp: entry->entrytime,
1629	BATADV_DUPLIST_TIMEOUT))
1630	break;
1631
1632	if (entry->crc != crc)
1633	continue;
1634
1635	/* are the originators both known and not anonymous? */
1636	if (orig && !is_zero_ether_addr(addr: orig) &&
1637	!is_zero_ether_addr(addr: entry->orig)) {
1638	/* If known, check if the new frame came from
1639	* the same originator:
1640	* We are safe to take identical frames from the
1641	* same orig, if known, as multiplications in
1642	* the mesh are detected via the (orig, seqno) pair.
1643	* So we can be a bit more liberal here and allow
1644	* identical frames from the same orig which the source
1645	* host might have sent multiple times on purpose.
1646	*/
1647	if (batadv_compare_eth(data1: entry->orig, data2: orig))
1648	continue;
1649	}
1650
1651	/* this entry seems to match: same crc, not too old,
1652	* and from another gw. therefore return true to forbid it.
1653	*/
1654	ret = true;
1655	goto out;
1656	}
1657	/* not found, add a new entry (overwrite the oldest entry)
1658	* and allow it, its the first occurrence.
1659	*/
1660	curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1);
1661	curr %= BATADV_DUPLIST_SIZE;
1662	entry = &bat_priv->bla.bcast_duplist[curr];
1663	entry->crc = crc;
1664	entry->entrytime = jiffies;
1665
1666	/* known originator */
1667	if (orig)
1668	ether_addr_copy(dst: entry->orig, src: orig);
1669	/* anonymous originator */
1670	else
1671	eth_zero_addr(addr: entry->orig);
1672
1673	bat_priv->bla.bcast_duplist_curr = curr;
1674
1675	out:
1676	spin_unlock_bh(lock: &bat_priv->bla.bcast_duplist_lock);
1677
1678	return ret;
1679	}
1680
1681	/**
1682	* batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup.
1683	* @bat_priv: the bat priv with all the soft interface information
1684	* @skb: contains the multicast packet to be checked, decapsulated from a
1685	* unicast_packet
1686	*
1687	* Check if it is on our broadcast list. Another gateway might have sent the
1688	* same packet because it is connected to the same backbone, so we have to
1689	* remove this duplicate.
1690	*
1691	* Return: true if a packet is in the duplicate list, false otherwise.
1692	*/
1693	static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv,
1694	struct sk_buff *skb)
1695	{
1696	return batadv_bla_check_duplist(bat_priv, skb, payload_ptr: (u8 *)skb->data, NULL);
1697	}
1698
1699	/**
1700	* batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup.
1701	* @bat_priv: the bat priv with all the soft interface information
1702	* @skb: contains the bcast_packet to be checked
1703	*
1704	* Check if it is on our broadcast list. Another gateway might have sent the
1705	* same packet because it is connected to the same backbone, so we have to
1706	* remove this duplicate.
1707	*
1708	* Return: true if a packet is in the duplicate list, false otherwise.
1709	*/
1710	bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
1711	struct sk_buff *skb)
1712	{
1713	struct batadv_bcast_packet *bcast_packet;
1714	u8 *payload_ptr;
1715
1716	bcast_packet = (struct batadv_bcast_packet *)skb->data;
1717	payload_ptr = (u8 *)(bcast_packet + 1);
1718
1719	return batadv_bla_check_duplist(bat_priv, skb, payload_ptr,
1720	orig: bcast_packet->orig);
1721	}
1722
1723	/**
1724	* batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for
1725	* the VLAN identified by vid.
1726	* @bat_priv: the bat priv with all the soft interface information
1727	* @orig: originator mac address
1728	* @vid: VLAN identifier
1729	*
1730	* Return: true if orig is a backbone for this vid, false otherwise.
1731	*/
1732	bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig,
1733	unsigned short vid)
1734	{
1735	struct batadv_hashtable *hash = bat_priv->bla.backbone_hash;
1736	struct hlist_head *head;
1737	struct batadv_bla_backbone_gw *backbone_gw;
1738	int i;
1739
1740	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
1741	return false;
1742
1743	if (!hash)
1744	return false;
1745
1746	for (i = 0; i < hash->size; i++) {
1747	head = &hash->table[i];
1748
1749	rcu_read_lock();
1750	hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) {
1751	if (batadv_compare_eth(data1: backbone_gw->orig, data2: orig) &&
1752	backbone_gw->vid == vid) {
1753	rcu_read_unlock();
1754	return true;
1755	}
1756	}
1757	rcu_read_unlock();
1758	}
1759
1760	return false;
1761	}
1762
1763	/**
1764	* batadv_bla_is_backbone_gw() - check if originator is a backbone gw for a VLAN
1765	* @skb: the frame to be checked
1766	* @orig_node: the orig_node of the frame
1767	* @hdr_size: maximum length of the frame
1768	*
1769	* Return: true if the orig_node is also a gateway on the soft interface,
1770	* otherwise it returns false.
1771	*/
1772	bool batadv_bla_is_backbone_gw(struct sk_buff *skb,
1773	struct batadv_orig_node *orig_node, int hdr_size)
1774	{
1775	struct batadv_bla_backbone_gw *backbone_gw;
1776	unsigned short vid;
1777
1778	if (!atomic_read(v: &orig_node->bat_priv->bridge_loop_avoidance))
1779	return false;
1780
1781	/* first, find out the vid. */
1782	if (!pskb_may_pull(skb, len: hdr_size + ETH_HLEN))
1783	return false;
1784
1785	vid = batadv_get_vid(skb, header_len: hdr_size);
1786
1787	/* see if this originator is a backbone gw for this VLAN */
1788	backbone_gw = batadv_backbone_hash_find(bat_priv: orig_node->bat_priv,
1789	addr: orig_node->orig, vid);
1790	if (!backbone_gw)
1791	return false;
1792
1793	batadv_backbone_gw_put(backbone_gw);
1794	return true;
1795	}
1796
1797	/**
1798	* batadv_bla_free() - free all bla structures
1799	* @bat_priv: the bat priv with all the soft interface information
1800	*
1801	* for softinterface free or module unload
1802	*/
1803	void batadv_bla_free(struct batadv_priv *bat_priv)
1804	{
1805	struct batadv_hard_iface *primary_if;
1806
1807	cancel_delayed_work_sync(dwork: &bat_priv->bla.work);
1808	primary_if = batadv_primary_if_get_selected(bat_priv);
1809
1810	if (bat_priv->bla.claim_hash) {
1811	batadv_bla_purge_claims(bat_priv, primary_if, now: 1);
1812	batadv_hash_destroy(hash: bat_priv->bla.claim_hash);
1813	bat_priv->bla.claim_hash = NULL;
1814	}
1815	if (bat_priv->bla.backbone_hash) {
1816	batadv_bla_purge_backbone_gw(bat_priv, now: 1);
1817	batadv_hash_destroy(hash: bat_priv->bla.backbone_hash);
1818	bat_priv->bla.backbone_hash = NULL;
1819	}
1820	batadv_hardif_put(hard_iface: primary_if);
1821	}
1822
1823	/**
1824	* batadv_bla_loopdetect_check() - check and handle a detected loop
1825	* @bat_priv: the bat priv with all the soft interface information
1826	* @skb: the packet to check
1827	* @primary_if: interface where the request came on
1828	* @vid: the VLAN ID of the frame
1829	*
1830	* Checks if this packet is a loop detect frame which has been sent by us,
1831	* throws an uevent and logs the event if that is the case.
1832	*
1833	* Return: true if it is a loop detect frame which is to be dropped, false
1834	* otherwise.
1835	*/
1836	static bool
1837	batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
1838	struct batadv_hard_iface *primary_if,
1839	unsigned short vid)
1840	{
1841	struct batadv_bla_backbone_gw *backbone_gw;
1842	struct ethhdr *ethhdr;
1843	bool ret;
1844
1845	ethhdr = eth_hdr(skb);
1846
1847	/* Only check for the MAC address and skip more checks here for
1848	* performance reasons - this function is on the hotpath, after all.
1849	*/
1850	if (!batadv_compare_eth(data1: ethhdr->h_source,
1851	data2: bat_priv->bla.loopdetect_addr))
1852	return false;
1853
1854	/* If the packet came too late, don't forward it on the mesh
1855	* but don't consider that as loop. It might be a coincidence.
1856	*/
1857	if (batadv_has_timed_out(timestamp: bat_priv->bla.loopdetect_lasttime,
1858	BATADV_BLA_LOOPDETECT_TIMEOUT))
1859	return true;
1860
1861	backbone_gw = batadv_bla_get_backbone_gw(bat_priv,
1862	orig: primary_if->net_dev->dev_addr,
1863	vid, own_backbone: true);
1864	if (unlikely(!backbone_gw))
1865	return true;
1866
1867	ret = queue_work(wq: batadv_event_workqueue, work: &backbone_gw->report_work);
1868
1869	/* backbone_gw is unreferenced in the report work function
1870	* if queue_work() call was successful
1871	*/
1872	if (!ret)
1873	batadv_backbone_gw_put(backbone_gw);
1874
1875	return true;
1876	}
1877
1878	/**
1879	* batadv_bla_rx() - check packets coming from the mesh.
1880	* @bat_priv: the bat priv with all the soft interface information
1881	* @skb: the frame to be checked
1882	* @vid: the VLAN ID of the frame
1883	* @packet_type: the batman packet type this frame came in
1884	*
1885	* batadv_bla_rx avoidance checks if:
1886	* * we have to race for a claim
1887	* * if the frame is allowed on the LAN
1888	*
1889	* In these cases, the skb is further handled by this function
1890	*
1891	* Return: true if handled, otherwise it returns false and the caller shall
1892	* further process the skb.
1893	*/
1894	bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
1895	unsigned short vid, int packet_type)
1896	{
1897	struct batadv_bla_backbone_gw *backbone_gw;
1898	struct ethhdr *ethhdr;
1899	struct batadv_bla_claim search_claim, *claim = NULL;
1900	struct batadv_hard_iface *primary_if;
1901	bool own_claim;
1902	bool ret;
1903
1904	ethhdr = eth_hdr(skb);
1905
1906	primary_if = batadv_primary_if_get_selected(bat_priv);
1907	if (!primary_if)
1908	goto handled;
1909
1910	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
1911	goto allow;
1912
1913	if (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid))
1914	goto handled;
1915
1916	if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
1917	/* don't allow multicast packets while requests are in flight */
1918	if (is_multicast_ether_addr(addr: ethhdr->h_dest))
1919	/* Both broadcast flooding or multicast-via-unicasts
1920	* delivery might send to multiple backbone gateways
1921	* sharing the same LAN and therefore need to coordinate
1922	* which backbone gateway forwards into the LAN,
1923	* by claiming the payload source address.
1924	*
1925	* Broadcast flooding and multicast-via-unicasts
1926	* delivery use the following two batman packet types.
1927	* Note: explicitly exclude BATADV_UNICAST_4ADDR,
1928	* as the DHCP gateway feature will send explicitly
1929	* to only one BLA gateway, so the claiming process
1930	* should be avoided there.
1931	*/
1932	if (packet_type == BATADV_BCAST ||
1933	packet_type == BATADV_UNICAST)
1934	goto handled;
1935
1936	/* potential duplicates from foreign BLA backbone gateways via
1937	* multicast-in-unicast packets
1938	*/
1939	if (is_multicast_ether_addr(addr: ethhdr->h_dest) &&
1940	packet_type == BATADV_UNICAST &&
1941	batadv_bla_check_ucast_duplist(bat_priv, skb))
1942	goto handled;
1943
1944	ether_addr_copy(dst: search_claim.addr, src: ethhdr->h_source);
1945	search_claim.vid = vid;
1946	claim = batadv_claim_hash_find(bat_priv, data: &search_claim);
1947
1948	if (!claim) {
1949	/* possible optimization: race for a claim */
1950	/* No claim exists yet, claim it for us!
1951	*/
1952
1953	batadv_dbg(BATADV_DBG_BLA, bat_priv,
1954	"%s(): Unclaimed MAC %pM found. Claim it. Local: %s\n",
1955	__func__, ethhdr->h_source,
1956	batadv_is_my_client(bat_priv,
1957	ethhdr->h_source, vid) ?
1958	"yes" : "no");
1959	batadv_handle_claim(bat_priv, primary_if,
1960	backbone_addr: primary_if->net_dev->dev_addr,
1961	claim_addr: ethhdr->h_source, vid);
1962	goto allow;
1963	}
1964
1965	/* if it is our own claim ... */
1966	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
1967	own_claim = batadv_compare_eth(data1: backbone_gw->orig,
1968	data2: primary_if->net_dev->dev_addr);
1969	batadv_backbone_gw_put(backbone_gw);
1970
1971	if (own_claim) {
1972	/* ... allow it in any case */
1973	claim->lasttime = jiffies;
1974	goto allow;
1975	}
1976
1977	/* if it is a multicast ... */
1978	if (is_multicast_ether_addr(addr: ethhdr->h_dest) &&
1979	(packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) {
1980	/* ... drop it. the responsible gateway is in charge.
1981	*
1982	* We need to check packet type because with the gateway
1983	* feature, broadcasts (like DHCP requests) may be sent
1984	* using a unicast 4 address packet type. See comment above.
1985	*/
1986	goto handled;
1987	} else {
1988	/* seems the client considers us as its best gateway.
1989	* send a claim and update the claim table
1990	* immediately.
1991	*/
1992	batadv_handle_claim(bat_priv, primary_if,
1993	backbone_addr: primary_if->net_dev->dev_addr,
1994	claim_addr: ethhdr->h_source, vid);
1995	goto allow;
1996	}
1997	allow:
1998	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
1999	ret = false;
2000	goto out;
2001
2002	handled:
2003	kfree_skb(skb);
2004	ret = true;
2005
2006	out:
2007	batadv_hardif_put(hard_iface: primary_if);
2008	batadv_claim_put(claim);
2009	return ret;
2010	}
2011
2012	/**
2013	* batadv_bla_tx() - check packets going into the mesh
2014	* @bat_priv: the bat priv with all the soft interface information
2015	* @skb: the frame to be checked
2016	* @vid: the VLAN ID of the frame
2017	*
2018	* batadv_bla_tx checks if:
2019	* * a claim was received which has to be processed
2020	* * the frame is allowed on the mesh
2021	*
2022	* in these cases, the skb is further handled by this function.
2023	*
2024	* This call might reallocate skb data.
2025	*
2026	* Return: true if handled, otherwise it returns false and the caller shall
2027	* further process the skb.
2028	*/
2029	bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
2030	unsigned short vid)
2031	{
2032	struct ethhdr *ethhdr;
2033	struct batadv_bla_claim search_claim, *claim = NULL;
2034	struct batadv_bla_backbone_gw *backbone_gw;
2035	struct batadv_hard_iface *primary_if;
2036	bool client_roamed;
2037	bool ret = false;
2038
2039	primary_if = batadv_primary_if_get_selected(bat_priv);
2040	if (!primary_if)
2041	goto out;
2042
2043	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
2044	goto allow;
2045
2046	if (batadv_bla_process_claim(bat_priv, primary_if, skb))
2047	goto handled;
2048
2049	ethhdr = eth_hdr(skb);
2050
2051	if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
2052	/* don't allow broadcasts while requests are in flight */
2053	if (is_multicast_ether_addr(addr: ethhdr->h_dest))
2054	goto handled;
2055
2056	ether_addr_copy(dst: search_claim.addr, src: ethhdr->h_source);
2057	search_claim.vid = vid;
2058
2059	claim = batadv_claim_hash_find(bat_priv, data: &search_claim);
2060
2061	/* if no claim exists, allow it. */
2062	if (!claim)
2063	goto allow;
2064
2065	/* check if we are responsible. */
2066	backbone_gw = batadv_bla_claim_get_backbone_gw(claim);
2067	client_roamed = batadv_compare_eth(data1: backbone_gw->orig,
2068	data2: primary_if->net_dev->dev_addr);
2069	batadv_backbone_gw_put(backbone_gw);
2070
2071	if (client_roamed) {
2072	/* if yes, the client has roamed and we have
2073	* to unclaim it.
2074	*/
2075	if (batadv_has_timed_out(timestamp: claim->lasttime, timeout: 100)) {
2076	/* only unclaim if the last claim entry is
2077	* older than 100 ms to make sure we really
2078	* have a roaming client here.
2079	*/
2080	batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Roaming client %pM detected. Unclaim it.\n",
2081	__func__, ethhdr->h_source);
2082	batadv_handle_unclaim(bat_priv, primary_if,
2083	backbone_addr: primary_if->net_dev->dev_addr,
2084	claim_addr: ethhdr->h_source, vid);
2085	goto allow;
2086	} else {
2087	batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Race for claim %pM detected. Drop packet.\n",
2088	__func__, ethhdr->h_source);
2089	goto handled;
2090	}
2091	}
2092
2093	/* check if it is a multicast/broadcast frame */
2094	if (is_multicast_ether_addr(addr: ethhdr->h_dest)) {
2095	/* drop it. the responsible gateway has forwarded it into
2096	* the backbone network.
2097	*/
2098	goto handled;
2099	} else {
2100	/* we must allow it. at least if we are
2101	* responsible for the DESTINATION.
2102	*/
2103	goto allow;
2104	}
2105	allow:
2106	batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid);
2107	ret = false;
2108	goto out;
2109	handled:
2110	ret = true;
2111	out:
2112	batadv_hardif_put(hard_iface: primary_if);
2113	batadv_claim_put(claim);
2114	return ret;
2115	}
2116
2117	/**
2118	* batadv_bla_claim_dump_entry() - dump one entry of the claim table
2119	* to a netlink socket
2120	* @msg: buffer for the message
2121	* @portid: netlink port
2122	* @cb: Control block containing additional options
2123	* @primary_if: primary interface
2124	* @claim: entry to dump
2125	*
2126	* Return: 0 or error code.
2127	*/
2128	static int
2129	batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid,
2130	struct netlink_callback *cb,
2131	struct batadv_hard_iface *primary_if,
2132	struct batadv_bla_claim *claim)
2133	{
2134	const u8 *primary_addr = primary_if->net_dev->dev_addr;
2135	u16 backbone_crc;
2136	bool is_own;
2137	void *hdr;
2138	int ret = -EINVAL;
2139
2140	hdr = genlmsg_put(skb: msg, portid, seq: cb->nlh->nlmsg_seq,
2141	family: &batadv_netlink_family, NLM_F_MULTI,
2142	cmd: BATADV_CMD_GET_BLA_CLAIM);
2143	if (!hdr) {
2144	ret = -ENOBUFS;
2145	goto out;
2146	}
2147
2148	genl_dump_check_consistent(cb, user_hdr: hdr);
2149
2150	is_own = batadv_compare_eth(data1: claim->backbone_gw->orig,
2151	data2: primary_addr);
2152
2153	spin_lock_bh(lock: &claim->backbone_gw->crc_lock);
2154	backbone_crc = claim->backbone_gw->crc;
2155	spin_unlock_bh(lock: &claim->backbone_gw->crc_lock);
2156
2157	if (is_own)
2158	if (nla_put_flag(skb: msg, attrtype: BATADV_ATTR_BLA_OWN)) {
2159	genlmsg_cancel(skb: msg, hdr);
2160	goto out;
2161	}
2162
2163	if (nla_put(skb: msg, attrtype: BATADV_ATTR_BLA_ADDRESS, ETH_ALEN, data: claim->addr) ||
2164	nla_put_u16(skb: msg, attrtype: BATADV_ATTR_BLA_VID, value: claim->vid) ||
2165	nla_put(skb: msg, attrtype: BATADV_ATTR_BLA_BACKBONE, ETH_ALEN,
2166	data: claim->backbone_gw->orig) ||
2167	nla_put_u16(skb: msg, attrtype: BATADV_ATTR_BLA_CRC,
2168	value: backbone_crc)) {
2169	genlmsg_cancel(skb: msg, hdr);
2170	goto out;
2171	}
2172
2173	genlmsg_end(skb: msg, hdr);
2174	ret = 0;
2175
2176	out:
2177	return ret;
2178	}
2179
2180	/**
2181	* batadv_bla_claim_dump_bucket() - dump one bucket of the claim table
2182	* to a netlink socket
2183	* @msg: buffer for the message
2184	* @portid: netlink port
2185	* @cb: Control block containing additional options
2186	* @primary_if: primary interface
2187	* @hash: hash to dump
2188	* @bucket: bucket index to dump
2189	* @idx_skip: How many entries to skip
2190	*
2191	* Return: always 0.
2192	*/
2193	static int
2194	batadv_bla_claim_dump_bucket(struct sk_buff *msg, u32 portid,
2195	struct netlink_callback *cb,
2196	struct batadv_hard_iface *primary_if,
2197	struct batadv_hashtable *hash, unsigned int bucket,
2198	int *idx_skip)
2199	{
2200	struct batadv_bla_claim *claim;
2201	int idx = 0;
2202	int ret = 0;
2203
2204	spin_lock_bh(lock: &hash->list_locks[bucket]);
2205	cb->seq = atomic_read(v: &hash->generation) << 1 | 1;
2206
2207	hlist_for_each_entry(claim, &hash->table[bucket], hash_entry) {
2208	if (idx++ < *idx_skip)
2209	continue;
2210
2211	ret = batadv_bla_claim_dump_entry(msg, portid, cb,
2212	primary_if, claim);
2213	if (ret) {
2214	*idx_skip = idx - 1;
2215	goto unlock;
2216	}
2217	}
2218
2219	*idx_skip = 0;
2220	unlock:
2221	spin_unlock_bh(lock: &hash->list_locks[bucket]);
2222	return ret;
2223	}
2224
2225	/**
2226	* batadv_bla_claim_dump() - dump claim table to a netlink socket
2227	* @msg: buffer for the message
2228	* @cb: callback structure containing arguments
2229	*
2230	* Return: message length.
2231	*/
2232	int batadv_bla_claim_dump(struct sk_buff *msg, struct netlink_callback *cb)
2233	{
2234	struct batadv_hard_iface *primary_if = NULL;
2235	int portid = NETLINK_CB(cb->skb).portid;
2236	struct net *net = sock_net(sk: cb->skb->sk);
2237	struct net_device *soft_iface;
2238	struct batadv_hashtable *hash;
2239	struct batadv_priv *bat_priv;
2240	int bucket = cb->args[0];
2241	int idx = cb->args[1];
2242	int ifindex;
2243	int ret = 0;
2244
2245	ifindex = batadv_netlink_get_ifindex(nlh: cb->nlh,
2246	attrtype: BATADV_ATTR_MESH_IFINDEX);
2247	if (!ifindex)
2248	return -EINVAL;
2249
2250	soft_iface = dev_get_by_index(net, ifindex);
2251	if (!soft_iface || !batadv_softif_is_valid(net_dev: soft_iface)) {
2252	ret = -ENODEV;
2253	goto out;
2254	}
2255
2256	bat_priv = netdev_priv(dev: soft_iface);
2257	hash = bat_priv->bla.claim_hash;
2258
2259	primary_if = batadv_primary_if_get_selected(bat_priv);
2260	if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
2261	ret = -ENOENT;
2262	goto out;
2263	}
2264
2265	while (bucket < hash->size) {
2266	if (batadv_bla_claim_dump_bucket(msg, portid, cb, primary_if,
2267	hash, bucket, idx_skip: &idx))
2268	break;
2269	bucket++;
2270	}
2271
2272	cb->args[0] = bucket;
2273	cb->args[1] = idx;
2274
2275	ret = msg->len;
2276
2277	out:
2278	batadv_hardif_put(hard_iface: primary_if);
2279
2280	dev_put(dev: soft_iface);
2281
2282	return ret;
2283	}
2284
2285	/**
2286	* batadv_bla_backbone_dump_entry() - dump one entry of the backbone table to a
2287	* netlink socket
2288	* @msg: buffer for the message
2289	* @portid: netlink port
2290	* @cb: Control block containing additional options
2291	* @primary_if: primary interface
2292	* @backbone_gw: entry to dump
2293	*
2294	* Return: 0 or error code.
2295	*/
2296	static int
2297	batadv_bla_backbone_dump_entry(struct sk_buff *msg, u32 portid,
2298	struct netlink_callback *cb,
2299	struct batadv_hard_iface *primary_if,
2300	struct batadv_bla_backbone_gw *backbone_gw)
2301	{
2302	const u8 *primary_addr = primary_if->net_dev->dev_addr;
2303	u16 backbone_crc;
2304	bool is_own;
2305	int msecs;
2306	void *hdr;
2307	int ret = -EINVAL;
2308
2309	hdr = genlmsg_put(skb: msg, portid, seq: cb->nlh->nlmsg_seq,
2310	family: &batadv_netlink_family, NLM_F_MULTI,
2311	cmd: BATADV_CMD_GET_BLA_BACKBONE);
2312	if (!hdr) {
2313	ret = -ENOBUFS;
2314	goto out;
2315	}
2316
2317	genl_dump_check_consistent(cb, user_hdr: hdr);
2318
2319	is_own = batadv_compare_eth(data1: backbone_gw->orig, data2: primary_addr);
2320
2321	spin_lock_bh(lock: &backbone_gw->crc_lock);
2322	backbone_crc = backbone_gw->crc;
2323	spin_unlock_bh(lock: &backbone_gw->crc_lock);
2324
2325	msecs = jiffies_to_msecs(j: jiffies - backbone_gw->lasttime);
2326
2327	if (is_own)
2328	if (nla_put_flag(skb: msg, attrtype: BATADV_ATTR_BLA_OWN)) {
2329	genlmsg_cancel(skb: msg, hdr);
2330	goto out;
2331	}
2332
2333	if (nla_put(skb: msg, attrtype: BATADV_ATTR_BLA_BACKBONE, ETH_ALEN,
2334	data: backbone_gw->orig) ||
2335	nla_put_u16(skb: msg, attrtype: BATADV_ATTR_BLA_VID, value: backbone_gw->vid) ||
2336	nla_put_u16(skb: msg, attrtype: BATADV_ATTR_BLA_CRC,
2337	value: backbone_crc) ||
2338	nla_put_u32(skb: msg, attrtype: BATADV_ATTR_LAST_SEEN_MSECS, value: msecs)) {
2339	genlmsg_cancel(skb: msg, hdr);
2340	goto out;
2341	}
2342
2343	genlmsg_end(skb: msg, hdr);
2344	ret = 0;
2345
2346	out:
2347	return ret;
2348	}
2349
2350	/**
2351	* batadv_bla_backbone_dump_bucket() - dump one bucket of the backbone table to
2352	* a netlink socket
2353	* @msg: buffer for the message
2354	* @portid: netlink port
2355	* @cb: Control block containing additional options
2356	* @primary_if: primary interface
2357	* @hash: hash to dump
2358	* @bucket: bucket index to dump
2359	* @idx_skip: How many entries to skip
2360	*
2361	* Return: always 0.
2362	*/
2363	static int
2364	batadv_bla_backbone_dump_bucket(struct sk_buff *msg, u32 portid,
2365	struct netlink_callback *cb,
2366	struct batadv_hard_iface *primary_if,
2367	struct batadv_hashtable *hash,
2368	unsigned int bucket, int *idx_skip)
2369	{
2370	struct batadv_bla_backbone_gw *backbone_gw;
2371	int idx = 0;
2372	int ret = 0;
2373
2374	spin_lock_bh(lock: &hash->list_locks[bucket]);
2375	cb->seq = atomic_read(v: &hash->generation) << 1 | 1;
2376
2377	hlist_for_each_entry(backbone_gw, &hash->table[bucket], hash_entry) {
2378	if (idx++ < *idx_skip)
2379	continue;
2380
2381	ret = batadv_bla_backbone_dump_entry(msg, portid, cb,
2382	primary_if, backbone_gw);
2383	if (ret) {
2384	*idx_skip = idx - 1;
2385	goto unlock;
2386	}
2387	}
2388
2389	*idx_skip = 0;
2390	unlock:
2391	spin_unlock_bh(lock: &hash->list_locks[bucket]);
2392	return ret;
2393	}
2394
2395	/**
2396	* batadv_bla_backbone_dump() - dump backbone table to a netlink socket
2397	* @msg: buffer for the message
2398	* @cb: callback structure containing arguments
2399	*
2400	* Return: message length.
2401	*/
2402	int batadv_bla_backbone_dump(struct sk_buff *msg, struct netlink_callback *cb)
2403	{
2404	struct batadv_hard_iface *primary_if = NULL;
2405	int portid = NETLINK_CB(cb->skb).portid;
2406	struct net *net = sock_net(sk: cb->skb->sk);
2407	struct net_device *soft_iface;
2408	struct batadv_hashtable *hash;
2409	struct batadv_priv *bat_priv;
2410	int bucket = cb->args[0];
2411	int idx = cb->args[1];
2412	int ifindex;
2413	int ret = 0;
2414
2415	ifindex = batadv_netlink_get_ifindex(nlh: cb->nlh,
2416	attrtype: BATADV_ATTR_MESH_IFINDEX);
2417	if (!ifindex)
2418	return -EINVAL;
2419
2420	soft_iface = dev_get_by_index(net, ifindex);
2421	if (!soft_iface || !batadv_softif_is_valid(net_dev: soft_iface)) {
2422	ret = -ENODEV;
2423	goto out;
2424	}
2425
2426	bat_priv = netdev_priv(dev: soft_iface);
2427	hash = bat_priv->bla.backbone_hash;
2428
2429	primary_if = batadv_primary_if_get_selected(bat_priv);
2430	if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) {
2431	ret = -ENOENT;
2432	goto out;
2433	}
2434
2435	while (bucket < hash->size) {
2436	if (batadv_bla_backbone_dump_bucket(msg, portid, cb, primary_if,
2437	hash, bucket, idx_skip: &idx))
2438	break;
2439	bucket++;
2440	}
2441
2442	cb->args[0] = bucket;
2443	cb->args[1] = idx;
2444
2445	ret = msg->len;
2446
2447	out:
2448	batadv_hardif_put(hard_iface: primary_if);
2449
2450	dev_put(dev: soft_iface);
2451
2452	return ret;
2453	}
2454
2455	#ifdef CONFIG_BATMAN_ADV_DAT
2456	/**
2457	* batadv_bla_check_claim() - check if address is claimed
2458	*
2459	* @bat_priv: the bat priv with all the soft interface information
2460	* @addr: mac address of which the claim status is checked
2461	* @vid: the VLAN ID
2462	*
2463	* addr is checked if this address is claimed by the local device itself.
2464	*
2465	* Return: true if bla is disabled or the mac is claimed by the device,
2466	* false if the device addr is already claimed by another gateway
2467	*/
2468	bool batadv_bla_check_claim(struct batadv_priv *bat_priv,
2469	u8 *addr, unsigned short vid)
2470	{
2471	struct batadv_bla_claim search_claim;
2472	struct batadv_bla_claim *claim = NULL;
2473	struct batadv_hard_iface *primary_if = NULL;
2474	bool ret = true;
2475
2476	if (!atomic_read(v: &bat_priv->bridge_loop_avoidance))
2477	return ret;
2478
2479	primary_if = batadv_primary_if_get_selected(bat_priv);
2480	if (!primary_if)
2481	return ret;
2482
2483	/* First look if the mac address is claimed */
2484	ether_addr_copy(dst: search_claim.addr, src: addr);
2485	search_claim.vid = vid;
2486
2487	claim = batadv_claim_hash_find(bat_priv, data: &search_claim);
2488
2489	/* If there is a claim and we are not owner of the claim,
2490	* return false.
2491	*/
2492	if (claim) {
2493	if (!batadv_compare_eth(data1: claim->backbone_gw->orig,
2494	data2: primary_if->net_dev->dev_addr))
2495	ret = false;
2496	batadv_claim_put(claim);
2497	}
2498
2499	batadv_hardif_put(hard_iface: primary_if);
2500	return ret;
2501	}
2502	#endif
2503