1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) B.A.T.M.A.N. contributors:
3  *
4  * Marek Lindner, Simon Wunderlich
5  */
6 
7 #include "mesh-interface.h"
8 #include "main.h"
9 
10 #include <linux/atomic.h>
11 #include <linux/byteorder/generic.h>
12 #include <linux/cache.h>
13 #include <linux/compiler.h>
14 #include <linux/container_of.h>
15 #include <linux/cpumask.h>
16 #include <linux/errno.h>
17 #include <linux/etherdevice.h>
18 #include <linux/ethtool.h>
19 #include <linux/gfp.h>
20 #include <linux/if_ether.h>
21 #include <linux/if_vlan.h>
22 #include <linux/jiffies.h>
23 #include <linux/kref.h>
24 #include <linux/list.h>
25 #include <linux/lockdep.h>
26 #include <linux/netdevice.h>
27 #include <linux/netlink.h>
28 #include <linux/percpu.h>
29 #include <linux/random.h>
30 #include <linux/rculist.h>
31 #include <linux/rcupdate.h>
32 #include <linux/skbuff.h>
33 #include <linux/slab.h>
34 #include <linux/socket.h>
35 #include <linux/spinlock.h>
36 #include <linux/stddef.h>
37 #include <linux/string.h>
38 #include <linux/types.h>
39 #include <net/netlink.h>
40 #include <uapi/linux/batadv_packet.h>
41 #include <uapi/linux/batman_adv.h>
42 
43 #include "bat_algo.h"
44 #include "bridge_loop_avoidance.h"
45 #include "distributed-arp-table.h"
46 #include "gateway_client.h"
47 #include "hard-interface.h"
48 #include "multicast.h"
49 #include "network-coding.h"
50 #include "send.h"
51 #include "translation-table.h"
52 
53 /**
54  * batadv_skb_head_push() - Increase header size and move (push) head pointer
55  * @skb: packet buffer which should be modified
56  * @len: number of bytes to add
57  *
58  * Return: 0 on success or negative error number in case of failure
59  */
60 int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
61 {
62 	int result;
63 
64 	/* TODO: We must check if we can release all references to non-payload
65 	 * data using __skb_header_release in our skbs to allow skb_cow_header
66 	 * to work optimally. This means that those skbs are not allowed to read
67 	 * or write any data which is before the current position of skb->data
68 	 * after that call and thus allow other skbs with the same data buffer
69 	 * to write freely in that area.
70 	 */
71 	result = skb_cow_head(skb, len);
72 	if (result < 0)
73 		return result;
74 
75 	skb_push(skb, len);
76 	return 0;
77 }
78 
79 /**
80  * batadv_sum_counter() - Sum the cpu-local counters for index 'idx'
81  * @bat_priv: the bat priv with all the mesh interface information
82  * @idx: index of counter to sum up
83  *
84  * Return: sum of all cpu-local counters
85  */
86 static u64 batadv_sum_counter(struct batadv_priv *bat_priv,  size_t idx)
87 {
88 	u64 *counters, sum = 0;
89 	int cpu;
90 
91 	for_each_possible_cpu(cpu) {
92 		counters = per_cpu_ptr(bat_priv->bat_counters, cpu);
93 		sum += counters[idx];
94 	}
95 
96 	return sum;
97 }
98 
99 static struct net_device_stats *batadv_interface_stats(struct net_device *dev)
100 {
101 	struct batadv_priv *bat_priv = netdev_priv(dev);
102 	struct net_device_stats *stats = &dev->stats;
103 
104 	stats->tx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_TX);
105 	stats->tx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_TX_BYTES);
106 	stats->tx_dropped = batadv_sum_counter(bat_priv, BATADV_CNT_TX_DROPPED);
107 	stats->rx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_RX);
108 	stats->rx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_RX_BYTES);
109 	return stats;
110 }
111 
112 static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
113 {
114 	struct batadv_priv *bat_priv = netdev_priv(dev);
115 	struct batadv_meshif_vlan *vlan;
116 	struct sockaddr *addr = p;
117 	u8 old_addr[ETH_ALEN];
118 
119 	if (!is_valid_ether_addr(addr->sa_data))
120 		return -EADDRNOTAVAIL;
121 
122 	ether_addr_copy(old_addr, dev->dev_addr);
123 	eth_hw_addr_set(dev, addr->sa_data);
124 
125 	/* only modify transtable if it has been initialized before */
126 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
127 		return 0;
128 
129 	rcu_read_lock();
130 	hlist_for_each_entry_rcu(vlan, &bat_priv->meshif_vlan_list, list) {
131 		batadv_tt_local_remove(bat_priv, old_addr, vlan->vid,
132 				       "mac address changed", false);
133 		batadv_tt_local_add(dev, addr->sa_data, vlan->vid,
134 				    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
135 	}
136 	rcu_read_unlock();
137 
138 	return 0;
139 }
140 
141 static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
142 {
143 	struct batadv_priv *bat_priv = netdev_priv(dev);
144 
145 	/* check ranges */
146 	if (new_mtu < ETH_MIN_MTU || new_mtu > batadv_hardif_min_mtu(dev))
147 		return -EINVAL;
148 
149 	WRITE_ONCE(dev->mtu, new_mtu);
150 	bat_priv->mtu_set_by_user = new_mtu;
151 
152 	return 0;
153 }
154 
155 /**
156  * batadv_interface_set_rx_mode() - set the rx mode of a device
157  * @dev: registered network device to modify
158  *
159  * We do not actually need to set any rx filters for the virtual batman
160  * mesh interface. However a dummy handler enables a user to set static
161  * multicast listeners for instance.
162  */
163 static void batadv_interface_set_rx_mode(struct net_device *dev)
164 {
165 }
166 
167 static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
168 				       struct net_device *mesh_iface)
169 {
170 	struct ethhdr *ethhdr;
171 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
172 	struct batadv_hard_iface *primary_if = NULL;
173 	struct batadv_bcast_packet *bcast_packet;
174 	static const u8 stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
175 					      0x00, 0x00};
176 	static const u8 ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
177 					       0x00, 0x00};
178 	enum batadv_dhcp_recipient dhcp_rcp = BATADV_DHCP_NO;
179 	u8 *dst_hint = NULL, chaddr[ETH_ALEN];
180 	struct vlan_ethhdr *vhdr;
181 	unsigned int header_len = 0;
182 	int data_len = skb->len, ret;
183 	unsigned long brd_delay = 0;
184 	bool do_bcast = false, client_added;
185 	unsigned short vid;
186 	u32 seqno;
187 	int gw_mode;
188 	enum batadv_forw_mode forw_mode = BATADV_FORW_BCAST;
189 	int mcast_is_routable = 0;
190 	int network_offset = ETH_HLEN;
191 	__be16 proto;
192 
193 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
194 		goto dropped;
195 
196 	/* reset control block to avoid left overs from previous users */
197 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
198 
199 	netif_trans_update(mesh_iface);
200 	vid = batadv_get_vid(skb, 0);
201 
202 	skb_reset_mac_header(skb);
203 	ethhdr = eth_hdr(skb);
204 
205 	proto = ethhdr->h_proto;
206 
207 	switch (ntohs(proto)) {
208 	case ETH_P_8021Q:
209 		if (!pskb_may_pull(skb, sizeof(*vhdr)))
210 			goto dropped;
211 		vhdr = vlan_eth_hdr(skb);
212 		proto = vhdr->h_vlan_encapsulated_proto;
213 
214 		/* drop batman-in-batman packets to prevent loops */
215 		if (proto != htons(ETH_P_BATMAN)) {
216 			network_offset += VLAN_HLEN;
217 			break;
218 		}
219 
220 		fallthrough;
221 	case ETH_P_BATMAN:
222 		goto dropped;
223 	}
224 
225 	skb_set_network_header(skb, network_offset);
226 
227 	if (batadv_bla_tx(bat_priv, skb, vid))
228 		goto dropped;
229 
230 	/* skb->data might have been reallocated by batadv_bla_tx() */
231 	ethhdr = eth_hdr(skb);
232 
233 	/* Register the client MAC in the transtable */
234 	if (!is_multicast_ether_addr(ethhdr->h_source) &&
235 	    !batadv_bla_is_loopdetect_mac(ethhdr->h_source)) {
236 		client_added = batadv_tt_local_add(mesh_iface, ethhdr->h_source,
237 						   vid, skb->skb_iif,
238 						   skb->mark);
239 		if (!client_added)
240 			goto dropped;
241 	}
242 
243 	/* Snoop address candidates from DHCPACKs for early DAT filling */
244 	batadv_dat_snoop_outgoing_dhcp_ack(bat_priv, skb, proto, vid);
245 
246 	/* don't accept stp packets. STP does not help in meshes.
247 	 * better use the bridge loop avoidance ...
248 	 *
249 	 * The same goes for ECTP sent at least by some Cisco Switches,
250 	 * it might confuse the mesh when used with bridge loop avoidance.
251 	 */
252 	if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
253 		goto dropped;
254 
255 	if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
256 		goto dropped;
257 
258 	gw_mode = atomic_read(&bat_priv->gw.mode);
259 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
260 		/* if gw mode is off, broadcast every packet */
261 		if (gw_mode == BATADV_GW_MODE_OFF) {
262 			do_bcast = true;
263 			goto send;
264 		}
265 
266 		dhcp_rcp = batadv_gw_dhcp_recipient_get(skb, &header_len,
267 							chaddr);
268 		/* skb->data may have been modified by
269 		 * batadv_gw_dhcp_recipient_get()
270 		 */
271 		ethhdr = eth_hdr(skb);
272 		/* if gw_mode is on, broadcast any non-DHCP message.
273 		 * All the DHCP packets are going to be sent as unicast
274 		 */
275 		if (dhcp_rcp == BATADV_DHCP_NO) {
276 			do_bcast = true;
277 			goto send;
278 		}
279 
280 		if (dhcp_rcp == BATADV_DHCP_TO_CLIENT)
281 			dst_hint = chaddr;
282 		else if ((gw_mode == BATADV_GW_MODE_SERVER) &&
283 			 (dhcp_rcp == BATADV_DHCP_TO_SERVER))
284 			/* gateways should not forward any DHCP message if
285 			 * directed to a DHCP server
286 			 */
287 			goto dropped;
288 
289 send:
290 		if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
291 			forw_mode = batadv_mcast_forw_mode(bat_priv, skb, vid,
292 							   &mcast_is_routable);
293 			switch (forw_mode) {
294 			case BATADV_FORW_BCAST:
295 				break;
296 			case BATADV_FORW_UCASTS:
297 			case BATADV_FORW_MCAST:
298 				do_bcast = false;
299 				break;
300 			case BATADV_FORW_NONE:
301 				fallthrough;
302 			default:
303 				goto dropped;
304 			}
305 		}
306 	}
307 
308 	batadv_skb_set_priority(skb, 0);
309 
310 	/* ethernet packet should be broadcasted */
311 	if (do_bcast) {
312 		primary_if = batadv_primary_if_get_selected(bat_priv);
313 		if (!primary_if)
314 			goto dropped;
315 
316 		/* in case of ARP request, we do not immediately broadcasti the
317 		 * packet, instead we first wait for DAT to try to retrieve the
318 		 * correct ARP entry
319 		 */
320 		if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
321 			brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
322 
323 		if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
324 			goto dropped;
325 
326 		bcast_packet = (struct batadv_bcast_packet *)skb->data;
327 		bcast_packet->version = BATADV_COMPAT_VERSION;
328 		bcast_packet->ttl = BATADV_TTL - 1;
329 
330 		/* batman packet type: broadcast */
331 		bcast_packet->packet_type = BATADV_BCAST;
332 		bcast_packet->reserved = 0;
333 
334 		/* hw address of first interface is the orig mac because only
335 		 * this mac is known throughout the mesh
336 		 */
337 		ether_addr_copy(bcast_packet->orig,
338 				primary_if->net_dev->dev_addr);
339 
340 		/* set broadcast sequence number */
341 		seqno = atomic_inc_return(&bat_priv->bcast_seqno);
342 		bcast_packet->seqno = htonl(seqno);
343 
344 		batadv_send_bcast_packet(bat_priv, skb, brd_delay, true);
345 	/* unicast packet */
346 	} else {
347 		/* DHCP packets going to a server will use the GW feature */
348 		if (dhcp_rcp == BATADV_DHCP_TO_SERVER) {
349 			ret = batadv_gw_out_of_range(bat_priv, skb);
350 			if (ret)
351 				goto dropped;
352 			ret = batadv_send_skb_via_gw(bat_priv, skb, vid);
353 		} else if (forw_mode == BATADV_FORW_UCASTS) {
354 			ret = batadv_mcast_forw_send(bat_priv, skb, vid,
355 						     mcast_is_routable);
356 		} else if (forw_mode == BATADV_FORW_MCAST) {
357 			ret = batadv_mcast_forw_mcsend(bat_priv, skb);
358 		} else {
359 			if (batadv_dat_snoop_outgoing_arp_request(bat_priv,
360 								  skb))
361 				goto dropped;
362 
363 			batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
364 
365 			ret = batadv_send_skb_via_tt(bat_priv, skb, dst_hint,
366 						     vid);
367 		}
368 		if (ret != NET_XMIT_SUCCESS)
369 			goto dropped_freed;
370 	}
371 
372 	batadv_inc_counter(bat_priv, BATADV_CNT_TX);
373 	batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
374 	goto end;
375 
376 dropped:
377 	kfree_skb(skb);
378 dropped_freed:
379 	batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
380 end:
381 	batadv_hardif_put(primary_if);
382 	return NETDEV_TX_OK;
383 }
384 
385 /**
386  * batadv_interface_rx() - receive ethernet frame on local batman-adv interface
387  * @mesh_iface: local interface which will receive the ethernet frame
388  * @skb: ethernet frame for @mesh_iface
389  * @hdr_size: size of already parsed batman-adv header
390  * @orig_node: originator from which the batman-adv packet was sent
391  *
392  * Sends an ethernet frame to the receive path of the local @mesh_iface.
393  * skb->data has still point to the batman-adv header with the size @hdr_size.
394  * The caller has to have parsed this header already and made sure that at least
395  * @hdr_size bytes are still available for pull in @skb.
396  *
397  * The packet may still get dropped. This can happen when the encapsulated
398  * ethernet frame is invalid or contains again an batman-adv packet. Also
399  * unicast packets will be dropped directly when it was sent between two
400  * isolated clients.
401  */
402 void batadv_interface_rx(struct net_device *mesh_iface,
403 			 struct sk_buff *skb, int hdr_size,
404 			 struct batadv_orig_node *orig_node)
405 {
406 	struct batadv_bcast_packet *batadv_bcast_packet;
407 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
408 	struct vlan_ethhdr *vhdr;
409 	struct ethhdr *ethhdr;
410 	unsigned short vid;
411 	int packet_type;
412 
413 	batadv_bcast_packet = (struct batadv_bcast_packet *)skb->data;
414 	packet_type = batadv_bcast_packet->packet_type;
415 
416 	skb_pull_rcsum(skb, hdr_size);
417 	skb_reset_mac_header(skb);
418 
419 	/* clean the netfilter state now that the batman-adv header has been
420 	 * removed
421 	 */
422 	nf_reset_ct(skb);
423 
424 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
425 		goto dropped;
426 
427 	vid = batadv_get_vid(skb, 0);
428 	ethhdr = eth_hdr(skb);
429 
430 	switch (ntohs(ethhdr->h_proto)) {
431 	case ETH_P_8021Q:
432 		if (!pskb_may_pull(skb, VLAN_ETH_HLEN))
433 			goto dropped;
434 
435 		vhdr = skb_vlan_eth_hdr(skb);
436 
437 		/* drop batman-in-batman packets to prevent loops */
438 		if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN))
439 			break;
440 
441 		fallthrough;
442 	case ETH_P_BATMAN:
443 		goto dropped;
444 	}
445 
446 	/* skb->dev & skb->pkt_type are set here */
447 	skb->protocol = eth_type_trans(skb, mesh_iface);
448 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
449 
450 	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
451 	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
452 			   skb->len + ETH_HLEN);
453 
454 	/* Let the bridge loop avoidance check the packet. If will
455 	 * not handle it, we can safely push it up.
456 	 */
457 	if (batadv_bla_rx(bat_priv, skb, vid, packet_type))
458 		goto out;
459 
460 	if (orig_node)
461 		batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
462 						     ethhdr->h_source, vid);
463 
464 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
465 		/* set the mark on broadcast packets if AP isolation is ON and
466 		 * the packet is coming from an "isolated" client
467 		 */
468 		if (batadv_vlan_ap_isola_get(bat_priv, vid) &&
469 		    batadv_tt_global_is_isolated(bat_priv, ethhdr->h_source,
470 						 vid)) {
471 			/* save bits in skb->mark not covered by the mask and
472 			 * apply the mark on the rest
473 			 */
474 			skb->mark &= ~bat_priv->isolation_mark_mask;
475 			skb->mark |= bat_priv->isolation_mark;
476 		}
477 	} else if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source,
478 					 ethhdr->h_dest, vid)) {
479 		goto dropped;
480 	}
481 
482 	netif_rx(skb);
483 	goto out;
484 
485 dropped:
486 	kfree_skb(skb);
487 out:
488 	return;
489 }
490 
491 /**
492  * batadv_meshif_vlan_release() - release vlan from lists and queue for free
493  *  after rcu grace period
494  * @ref: kref pointer of the vlan object
495  */
496 void batadv_meshif_vlan_release(struct kref *ref)
497 {
498 	struct batadv_meshif_vlan *vlan;
499 
500 	vlan = container_of(ref, struct batadv_meshif_vlan, refcount);
501 
502 	spin_lock_bh(&vlan->bat_priv->meshif_vlan_list_lock);
503 	hlist_del_rcu(&vlan->list);
504 	spin_unlock_bh(&vlan->bat_priv->meshif_vlan_list_lock);
505 
506 	kfree_rcu(vlan, rcu);
507 }
508 
509 /**
510  * batadv_meshif_vlan_get() - get the vlan object for a specific vid
511  * @bat_priv: the bat priv with all the mesh interface information
512  * @vid: the identifier of the vlan object to retrieve
513  *
514  * Return: the private data of the vlan matching the vid passed as argument or
515  * NULL otherwise. The refcounter of the returned object is incremented by 1.
516  */
517 struct batadv_meshif_vlan *batadv_meshif_vlan_get(struct batadv_priv *bat_priv,
518 						  unsigned short vid)
519 {
520 	struct batadv_meshif_vlan *vlan_tmp, *vlan = NULL;
521 
522 	rcu_read_lock();
523 	hlist_for_each_entry_rcu(vlan_tmp, &bat_priv->meshif_vlan_list, list) {
524 		if (vlan_tmp->vid != vid)
525 			continue;
526 
527 		if (!kref_get_unless_zero(&vlan_tmp->refcount))
528 			continue;
529 
530 		vlan = vlan_tmp;
531 		break;
532 	}
533 	rcu_read_unlock();
534 
535 	return vlan;
536 }
537 
538 /**
539  * batadv_meshif_create_vlan() - allocate the needed resources for a new vlan
540  * @bat_priv: the bat priv with all the mesh interface information
541  * @vid: the VLAN identifier
542  *
543  * Return: 0 on success, a negative error otherwise.
544  */
545 int batadv_meshif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
546 {
547 	struct batadv_meshif_vlan *vlan;
548 
549 	spin_lock_bh(&bat_priv->meshif_vlan_list_lock);
550 
551 	vlan = batadv_meshif_vlan_get(bat_priv, vid);
552 	if (vlan) {
553 		batadv_meshif_vlan_put(vlan);
554 		spin_unlock_bh(&bat_priv->meshif_vlan_list_lock);
555 		return -EEXIST;
556 	}
557 
558 	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
559 	if (!vlan) {
560 		spin_unlock_bh(&bat_priv->meshif_vlan_list_lock);
561 		return -ENOMEM;
562 	}
563 
564 	vlan->bat_priv = bat_priv;
565 	vlan->vid = vid;
566 	kref_init(&vlan->refcount);
567 
568 	atomic_set(&vlan->ap_isolation, 0);
569 
570 	kref_get(&vlan->refcount);
571 	hlist_add_head_rcu(&vlan->list, &bat_priv->meshif_vlan_list);
572 	spin_unlock_bh(&bat_priv->meshif_vlan_list_lock);
573 
574 	/* add a new TT local entry. This one will be marked with the NOPURGE
575 	 * flag
576 	 */
577 	batadv_tt_local_add(bat_priv->mesh_iface,
578 			    bat_priv->mesh_iface->dev_addr, vid,
579 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
580 
581 	/* don't return reference to new meshif_vlan */
582 	batadv_meshif_vlan_put(vlan);
583 
584 	return 0;
585 }
586 
587 /**
588  * batadv_meshif_destroy_vlan() - remove and destroy a meshif_vlan object
589  * @bat_priv: the bat priv with all the mesh interface information
590  * @vlan: the object to remove
591  */
592 static void batadv_meshif_destroy_vlan(struct batadv_priv *bat_priv,
593 				       struct batadv_meshif_vlan *vlan)
594 {
595 	/* explicitly remove the associated TT local entry because it is marked
596 	 * with the NOPURGE flag
597 	 */
598 	batadv_tt_local_remove(bat_priv, bat_priv->mesh_iface->dev_addr,
599 			       vlan->vid, "vlan interface destroyed", false);
600 
601 	batadv_meshif_vlan_put(vlan);
602 }
603 
604 /**
605  * batadv_interface_add_vid() - ndo_add_vid API implementation
606  * @dev: the netdev of the mesh interface
607  * @proto: protocol of the vlan id
608  * @vid: identifier of the new vlan
609  *
610  * Set up all the internal structures for handling the new vlan on top of the
611  * mesh interface
612  *
613  * Return: 0 on success or a negative error code in case of failure.
614  */
615 static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
616 				    unsigned short vid)
617 {
618 	struct batadv_priv *bat_priv = netdev_priv(dev);
619 	struct batadv_meshif_vlan *vlan;
620 
621 	/* only 802.1Q vlans are supported.
622 	 * batman-adv does not know how to handle other types
623 	 */
624 	if (proto != htons(ETH_P_8021Q))
625 		return -EINVAL;
626 
627 	/* VID 0 is only used to indicate "priority tag" frames which only
628 	 * contain priority information and no VID. No management structures
629 	 * should be created for this VID and it should be handled like an
630 	 * untagged frame.
631 	 */
632 	if (vid == 0)
633 		return 0;
634 
635 	vid |= BATADV_VLAN_HAS_TAG;
636 
637 	/* if a new vlan is getting created and it already exists, it means that
638 	 * it was not deleted yet. batadv_meshif_vlan_get() increases the
639 	 * refcount in order to revive the object.
640 	 *
641 	 * if it does not exist then create it.
642 	 */
643 	vlan = batadv_meshif_vlan_get(bat_priv, vid);
644 	if (!vlan)
645 		return batadv_meshif_create_vlan(bat_priv, vid);
646 
647 	/* add a new TT local entry. This one will be marked with the NOPURGE
648 	 * flag. This must be added again, even if the vlan object already
649 	 * exists, because the entry was deleted by kill_vid()
650 	 */
651 	batadv_tt_local_add(bat_priv->mesh_iface,
652 			    bat_priv->mesh_iface->dev_addr, vid,
653 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
654 
655 	return 0;
656 }
657 
658 /**
659  * batadv_interface_kill_vid() - ndo_kill_vid API implementation
660  * @dev: the netdev of the mesh interface
661  * @proto: protocol of the vlan id
662  * @vid: identifier of the deleted vlan
663  *
664  * Destroy all the internal structures used to handle the vlan identified by vid
665  * on top of the mesh interface
666  *
667  * Return: 0 on success, -EINVAL if the specified prototype is not ETH_P_8021Q
668  * or -ENOENT if the specified vlan id wasn't registered.
669  */
670 static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
671 				     unsigned short vid)
672 {
673 	struct batadv_priv *bat_priv = netdev_priv(dev);
674 	struct batadv_meshif_vlan *vlan;
675 
676 	/* only 802.1Q vlans are supported. batman-adv does not know how to
677 	 * handle other types
678 	 */
679 	if (proto != htons(ETH_P_8021Q))
680 		return -EINVAL;
681 
682 	/* "priority tag" frames are handled like "untagged" frames
683 	 * and no meshif_vlan needs to be destroyed
684 	 */
685 	if (vid == 0)
686 		return 0;
687 
688 	vlan = batadv_meshif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
689 	if (!vlan)
690 		return -ENOENT;
691 
692 	batadv_meshif_destroy_vlan(bat_priv, vlan);
693 
694 	/* finally free the vlan object */
695 	batadv_meshif_vlan_put(vlan);
696 
697 	return 0;
698 }
699 
700 /* batman-adv network devices have devices nesting below it and are a special
701  * "super class" of normal network devices; split their locks off into a
702  * separate class since they always nest.
703  */
704 static struct lock_class_key batadv_netdev_xmit_lock_key;
705 static struct lock_class_key batadv_netdev_addr_lock_key;
706 
707 /**
708  * batadv_set_lockdep_class_one() - Set lockdep class for a single tx queue
709  * @dev: device which owns the tx queue
710  * @txq: tx queue to modify
711  * @_unused: always NULL
712  */
713 static void batadv_set_lockdep_class_one(struct net_device *dev,
714 					 struct netdev_queue *txq,
715 					 void *_unused)
716 {
717 	lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
718 }
719 
720 /**
721  * batadv_set_lockdep_class() - Set txq and addr_list lockdep class
722  * @dev: network device to modify
723  */
724 static void batadv_set_lockdep_class(struct net_device *dev)
725 {
726 	lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
727 	netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
728 }
729 
730 /**
731  * batadv_meshif_init_late() - late stage initialization of mesh interface
732  * @dev: registered network device to modify
733  *
734  * Return: error code on failures
735  */
736 static int batadv_meshif_init_late(struct net_device *dev)
737 {
738 	struct batadv_priv *bat_priv;
739 	u32 random_seqno;
740 	int ret;
741 	size_t cnt_len = sizeof(u64) * BATADV_CNT_NUM;
742 
743 	batadv_set_lockdep_class(dev);
744 
745 	bat_priv = netdev_priv(dev);
746 	bat_priv->mesh_iface = dev;
747 
748 	/* batadv_interface_stats() needs to be available as soon as
749 	 * register_netdevice() has been called
750 	 */
751 	bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(u64));
752 	if (!bat_priv->bat_counters)
753 		return -ENOMEM;
754 
755 	atomic_set(&bat_priv->aggregated_ogms, 1);
756 	atomic_set(&bat_priv->bonding, 0);
757 #ifdef CONFIG_BATMAN_ADV_BLA
758 	atomic_set(&bat_priv->bridge_loop_avoidance, 1);
759 #endif
760 #ifdef CONFIG_BATMAN_ADV_DAT
761 	atomic_set(&bat_priv->distributed_arp_table, 1);
762 #endif
763 #ifdef CONFIG_BATMAN_ADV_MCAST
764 	atomic_set(&bat_priv->multicast_mode, 1);
765 	atomic_set(&bat_priv->multicast_fanout, 16);
766 	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);
767 	atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0);
768 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
769 	atomic_set(&bat_priv->mcast.num_no_mc_ptype_capa, 0);
770 #endif
771 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
772 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
773 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
774 	atomic_set(&bat_priv->orig_interval, 1000);
775 	atomic_set(&bat_priv->hop_penalty, 30);
776 #ifdef CONFIG_BATMAN_ADV_DEBUG
777 	atomic_set(&bat_priv->log_level, 0);
778 #endif
779 	atomic_set(&bat_priv->fragmentation, 1);
780 	atomic_set(&bat_priv->packet_size_max, BATADV_MAX_MTU);
781 	atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
782 	atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
783 
784 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
785 	atomic_set(&bat_priv->bcast_seqno, 1);
786 	atomic_set(&bat_priv->tt.vn, 0);
787 	atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
788 #ifdef CONFIG_BATMAN_ADV_BLA
789 	atomic_set(&bat_priv->bla.num_requests, 0);
790 #endif
791 	atomic_set(&bat_priv->tp_num, 0);
792 
793 	WRITE_ONCE(bat_priv->tt.local_changes, 0);
794 	bat_priv->tt.last_changeset = NULL;
795 	bat_priv->tt.last_changeset_len = 0;
796 	bat_priv->isolation_mark = 0;
797 	bat_priv->isolation_mark_mask = 0;
798 
799 	/* randomize initial seqno to avoid collision */
800 	get_random_bytes(&random_seqno, sizeof(random_seqno));
801 	atomic_set(&bat_priv->frag_seqno, random_seqno);
802 
803 	bat_priv->primary_if = NULL;
804 
805 	batadv_nc_init_bat_priv(bat_priv);
806 
807 	if (!bat_priv->algo_ops) {
808 		ret = batadv_algo_select(bat_priv, batadv_routing_algo);
809 		if (ret < 0)
810 			goto free_bat_counters;
811 	}
812 
813 	ret = batadv_mesh_init(dev);
814 	if (ret < 0)
815 		goto free_bat_counters;
816 
817 	return 0;
818 
819 free_bat_counters:
820 	free_percpu(bat_priv->bat_counters);
821 	bat_priv->bat_counters = NULL;
822 
823 	return ret;
824 }
825 
826 /**
827  * batadv_meshif_slave_add() - Add a slave interface to a batadv_mesh_interface
828  * @dev: batadv_mesh_interface used as master interface
829  * @slave_dev: net_device which should become the slave interface
830  * @extack: extended ACK report struct
831  *
832  * Return: 0 if successful or error otherwise.
833  */
834 static int batadv_meshif_slave_add(struct net_device *dev,
835 				   struct net_device *slave_dev,
836 				   struct netlink_ext_ack *extack)
837 {
838 	struct batadv_hard_iface *hard_iface;
839 	int ret = -EINVAL;
840 
841 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
842 	if (!hard_iface || hard_iface->mesh_iface)
843 		goto out;
844 
845 	ret = batadv_hardif_enable_interface(hard_iface, dev);
846 
847 out:
848 	batadv_hardif_put(hard_iface);
849 	return ret;
850 }
851 
852 /**
853  * batadv_meshif_slave_del() - Delete a slave iface from a batadv_mesh_interface
854  * @dev: batadv_mesh_interface used as master interface
855  * @slave_dev: net_device which should be removed from the master interface
856  *
857  * Return: 0 if successful or error otherwise.
858  */
859 static int batadv_meshif_slave_del(struct net_device *dev,
860 				   struct net_device *slave_dev)
861 {
862 	struct batadv_hard_iface *hard_iface;
863 	int ret = -EINVAL;
864 
865 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
866 
867 	if (!hard_iface || hard_iface->mesh_iface != dev)
868 		goto out;
869 
870 	batadv_hardif_disable_interface(hard_iface);
871 	ret = 0;
872 
873 out:
874 	batadv_hardif_put(hard_iface);
875 	return ret;
876 }
877 
878 static const struct net_device_ops batadv_netdev_ops = {
879 	.ndo_init = batadv_meshif_init_late,
880 	.ndo_get_stats = batadv_interface_stats,
881 	.ndo_vlan_rx_add_vid = batadv_interface_add_vid,
882 	.ndo_vlan_rx_kill_vid = batadv_interface_kill_vid,
883 	.ndo_set_mac_address = batadv_interface_set_mac_addr,
884 	.ndo_change_mtu = batadv_interface_change_mtu,
885 	.ndo_set_rx_mode = batadv_interface_set_rx_mode,
886 	.ndo_start_xmit = batadv_interface_tx,
887 	.ndo_validate_addr = eth_validate_addr,
888 	.ndo_add_slave = batadv_meshif_slave_add,
889 	.ndo_del_slave = batadv_meshif_slave_del,
890 };
891 
892 static void batadv_get_drvinfo(struct net_device *dev,
893 			       struct ethtool_drvinfo *info)
894 {
895 	strscpy(info->driver, "B.A.T.M.A.N. advanced", sizeof(info->driver));
896 	strscpy(info->version, BATADV_SOURCE_VERSION, sizeof(info->version));
897 	strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
898 	strscpy(info->bus_info, "batman", sizeof(info->bus_info));
899 }
900 
901 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
902  * Declare each description string in struct.name[] to get fixed sized buffer
903  * and compile time checking for strings longer than ETH_GSTRING_LEN.
904  */
905 static const struct {
906 	const char name[ETH_GSTRING_LEN];
907 } batadv_counters_strings[] = {
908 	{ "tx" },
909 	{ "tx_bytes" },
910 	{ "tx_dropped" },
911 	{ "rx" },
912 	{ "rx_bytes" },
913 	{ "forward" },
914 	{ "forward_bytes" },
915 	{ "mgmt_tx" },
916 	{ "mgmt_tx_bytes" },
917 	{ "mgmt_rx" },
918 	{ "mgmt_rx_bytes" },
919 	{ "frag_tx" },
920 	{ "frag_tx_bytes" },
921 	{ "frag_rx" },
922 	{ "frag_rx_bytes" },
923 	{ "frag_fwd" },
924 	{ "frag_fwd_bytes" },
925 	{ "tt_request_tx" },
926 	{ "tt_request_rx" },
927 	{ "tt_response_tx" },
928 	{ "tt_response_rx" },
929 	{ "tt_roam_adv_tx" },
930 	{ "tt_roam_adv_rx" },
931 #ifdef CONFIG_BATMAN_ADV_MCAST
932 	{ "mcast_tx" },
933 	{ "mcast_tx_bytes" },
934 	{ "mcast_tx_local" },
935 	{ "mcast_tx_local_bytes" },
936 	{ "mcast_rx" },
937 	{ "mcast_rx_bytes" },
938 	{ "mcast_rx_local" },
939 	{ "mcast_rx_local_bytes" },
940 	{ "mcast_fwd" },
941 	{ "mcast_fwd_bytes" },
942 #endif
943 #ifdef CONFIG_BATMAN_ADV_DAT
944 	{ "dat_get_tx" },
945 	{ "dat_get_rx" },
946 	{ "dat_put_tx" },
947 	{ "dat_put_rx" },
948 	{ "dat_cached_reply_tx" },
949 #endif
950 #ifdef CONFIG_BATMAN_ADV_NC
951 	{ "nc_code" },
952 	{ "nc_code_bytes" },
953 	{ "nc_recode" },
954 	{ "nc_recode_bytes" },
955 	{ "nc_buffer" },
956 	{ "nc_decode" },
957 	{ "nc_decode_bytes" },
958 	{ "nc_decode_failed" },
959 	{ "nc_sniffed" },
960 #endif
961 };
962 
963 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data)
964 {
965 	if (stringset == ETH_SS_STATS)
966 		memcpy(data, batadv_counters_strings,
967 		       sizeof(batadv_counters_strings));
968 }
969 
970 static void batadv_get_ethtool_stats(struct net_device *dev,
971 				     struct ethtool_stats *stats, u64 *data)
972 {
973 	struct batadv_priv *bat_priv = netdev_priv(dev);
974 	int i;
975 
976 	for (i = 0; i < BATADV_CNT_NUM; i++)
977 		data[i] = batadv_sum_counter(bat_priv, i);
978 }
979 
980 static int batadv_get_sset_count(struct net_device *dev, int stringset)
981 {
982 	if (stringset == ETH_SS_STATS)
983 		return BATADV_CNT_NUM;
984 
985 	return -EOPNOTSUPP;
986 }
987 
988 static const struct ethtool_ops batadv_ethtool_ops = {
989 	.get_drvinfo = batadv_get_drvinfo,
990 	.get_link = ethtool_op_get_link,
991 	.get_strings = batadv_get_strings,
992 	.get_ethtool_stats = batadv_get_ethtool_stats,
993 	.get_sset_count = batadv_get_sset_count,
994 };
995 
996 /**
997  * batadv_meshif_free() - Deconstructor of batadv_mesh_interface
998  * @dev: Device to cleanup and remove
999  */
1000 static void batadv_meshif_free(struct net_device *dev)
1001 {
1002 	batadv_mesh_free(dev);
1003 
1004 	/* some scheduled RCU callbacks need the bat_priv struct to accomplish
1005 	 * their tasks. Wait for them all to be finished before freeing the
1006 	 * netdev and its private data (bat_priv)
1007 	 */
1008 	rcu_barrier();
1009 }
1010 
1011 /**
1012  * batadv_meshif_init_early() - early stage initialization of mesh interface
1013  * @dev: registered network device to modify
1014  */
1015 static void batadv_meshif_init_early(struct net_device *dev)
1016 {
1017 	ether_setup(dev);
1018 
1019 	dev->netdev_ops = &batadv_netdev_ops;
1020 	dev->needs_free_netdev = true;
1021 	dev->priv_destructor = batadv_meshif_free;
1022 	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
1023 	dev->priv_flags |= IFF_NO_QUEUE;
1024 	dev->lltx = true;
1025 	dev->netns_immutable = true;
1026 
1027 	/* can't call min_mtu, because the needed variables
1028 	 * have not been initialized yet
1029 	 */
1030 	dev->mtu = ETH_DATA_LEN;
1031 	dev->max_mtu = BATADV_MAX_MTU;
1032 
1033 	/* generate random address */
1034 	eth_hw_addr_random(dev);
1035 
1036 	dev->ethtool_ops = &batadv_ethtool_ops;
1037 }
1038 
1039 /**
1040  * batadv_meshif_validate() - validate configuration of new batadv link
1041  * @tb: IFLA_INFO_DATA netlink attributes
1042  * @data: enum batadv_ifla_attrs attributes
1043  * @extack: extended ACK report struct
1044  *
1045  * Return: 0 if successful or error otherwise.
1046  */
1047 static int batadv_meshif_validate(struct nlattr *tb[], struct nlattr *data[],
1048 				  struct netlink_ext_ack *extack)
1049 {
1050 	struct batadv_algo_ops *algo_ops;
1051 
1052 	if (!data)
1053 		return 0;
1054 
1055 	if (data[IFLA_BATADV_ALGO_NAME]) {
1056 		algo_ops = batadv_algo_get(nla_data(data[IFLA_BATADV_ALGO_NAME]));
1057 		if (!algo_ops)
1058 			return -EINVAL;
1059 	}
1060 
1061 	return 0;
1062 }
1063 
1064 /**
1065  * batadv_meshif_newlink() - pre-initialize and register new batadv link
1066  * @dev: network device to register
1067  * @params: rtnl newlink parameters
1068  * @extack: extended ACK report struct
1069  *
1070  * Return: 0 if successful or error otherwise.
1071  */
1072 static int batadv_meshif_newlink(struct net_device *dev,
1073 				 struct rtnl_newlink_params *params,
1074 				 struct netlink_ext_ack *extack)
1075 {
1076 	struct batadv_priv *bat_priv = netdev_priv(dev);
1077 	struct nlattr **data = params->data;
1078 	const char *algo_name;
1079 	int err;
1080 
1081 	if (data && data[IFLA_BATADV_ALGO_NAME]) {
1082 		algo_name = nla_data(data[IFLA_BATADV_ALGO_NAME]);
1083 		err = batadv_algo_select(bat_priv, algo_name);
1084 		if (err)
1085 			return -EINVAL;
1086 	}
1087 
1088 	return register_netdevice(dev);
1089 }
1090 
1091 /**
1092  * batadv_meshif_destroy_netlink() - deletion of batadv_mesh_interface via
1093  *  netlink
1094  * @mesh_iface: the to-be-removed batman-adv interface
1095  * @head: list pointer
1096  */
1097 static void batadv_meshif_destroy_netlink(struct net_device *mesh_iface,
1098 					  struct list_head *head)
1099 {
1100 	struct batadv_priv *bat_priv = netdev_priv(mesh_iface);
1101 	struct batadv_hard_iface *hard_iface;
1102 	struct batadv_meshif_vlan *vlan;
1103 
1104 	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {
1105 		if (hard_iface->mesh_iface == mesh_iface)
1106 			batadv_hardif_disable_interface(hard_iface);
1107 	}
1108 
1109 	/* destroy the "untagged" VLAN */
1110 	vlan = batadv_meshif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1111 	if (vlan) {
1112 		batadv_meshif_destroy_vlan(bat_priv, vlan);
1113 		batadv_meshif_vlan_put(vlan);
1114 	}
1115 
1116 	unregister_netdevice_queue(mesh_iface, head);
1117 }
1118 
1119 /**
1120  * batadv_meshif_is_valid() - Check whether device is a batadv mesh interface
1121  * @net_dev: device which should be checked
1122  *
1123  * Return: true when net_dev is a batman-adv interface, false otherwise
1124  */
1125 bool batadv_meshif_is_valid(const struct net_device *net_dev)
1126 {
1127 	if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
1128 		return true;
1129 
1130 	return false;
1131 }
1132 
1133 static const struct nla_policy batadv_ifla_policy[IFLA_BATADV_MAX + 1] = {
1134 	[IFLA_BATADV_ALGO_NAME]	= { .type = NLA_NUL_STRING },
1135 };
1136 
1137 struct rtnl_link_ops batadv_link_ops __read_mostly = {
1138 	.kind		= "batadv",
1139 	.priv_size	= sizeof(struct batadv_priv),
1140 	.setup		= batadv_meshif_init_early,
1141 	.maxtype	= IFLA_BATADV_MAX,
1142 	.policy		= batadv_ifla_policy,
1143 	.validate	= batadv_meshif_validate,
1144 	.newlink	= batadv_meshif_newlink,
1145 	.dellink	= batadv_meshif_destroy_netlink,
1146 };
1147