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