1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2019  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/printk.h>
30 #include <linux/random.h>
31 #include <linux/rculist.h>
32 #include <linux/rcupdate.h>
33 #include <linux/rtnetlink.h>
34 #include <linux/skbuff.h>
35 #include <linux/slab.h>
36 #include <linux/socket.h>
37 #include <linux/spinlock.h>
38 #include <linux/stddef.h>
39 #include <linux/string.h>
40 #include <linux/types.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 "debugfs.h"
47 #include "distributed-arp-table.h"
48 #include "gateway_client.h"
49 #include "hard-interface.h"
50 #include "multicast.h"
51 #include "network-coding.h"
52 #include "originator.h"
53 #include "send.h"
54 #include "sysfs.h"
55 #include "translation-table.h"
56 
57 /**
58  * batadv_skb_head_push() - Increase header size and move (push) head pointer
59  * @skb: packet buffer which should be modified
60  * @len: number of bytes to add
61  *
62  * Return: 0 on success or negative error number in case of failure
63  */
64 int batadv_skb_head_push(struct sk_buff *skb, unsigned int len)
65 {
66 	int result;
67 
68 	/* TODO: We must check if we can release all references to non-payload
69 	 * data using __skb_header_release in our skbs to allow skb_cow_header
70 	 * to work optimally. This means that those skbs are not allowed to read
71 	 * or write any data which is before the current position of skb->data
72 	 * after that call and thus allow other skbs with the same data buffer
73 	 * to write freely in that area.
74 	 */
75 	result = skb_cow_head(skb, len);
76 	if (result < 0)
77 		return result;
78 
79 	skb_push(skb, len);
80 	return 0;
81 }
82 
83 static int batadv_interface_open(struct net_device *dev)
84 {
85 	netif_start_queue(dev);
86 	return 0;
87 }
88 
89 static int batadv_interface_release(struct net_device *dev)
90 {
91 	netif_stop_queue(dev);
92 	return 0;
93 }
94 
95 /**
96  * batadv_sum_counter() - Sum the cpu-local counters for index 'idx'
97  * @bat_priv: the bat priv with all the soft interface information
98  * @idx: index of counter to sum up
99  *
100  * Return: sum of all cpu-local counters
101  */
102 static u64 batadv_sum_counter(struct batadv_priv *bat_priv,  size_t idx)
103 {
104 	u64 *counters, sum = 0;
105 	int cpu;
106 
107 	for_each_possible_cpu(cpu) {
108 		counters = per_cpu_ptr(bat_priv->bat_counters, cpu);
109 		sum += counters[idx];
110 	}
111 
112 	return sum;
113 }
114 
115 static struct net_device_stats *batadv_interface_stats(struct net_device *dev)
116 {
117 	struct batadv_priv *bat_priv = netdev_priv(dev);
118 	struct net_device_stats *stats = &dev->stats;
119 
120 	stats->tx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_TX);
121 	stats->tx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_TX_BYTES);
122 	stats->tx_dropped = batadv_sum_counter(bat_priv, BATADV_CNT_TX_DROPPED);
123 	stats->rx_packets = batadv_sum_counter(bat_priv, BATADV_CNT_RX);
124 	stats->rx_bytes = batadv_sum_counter(bat_priv, BATADV_CNT_RX_BYTES);
125 	return stats;
126 }
127 
128 static int batadv_interface_set_mac_addr(struct net_device *dev, void *p)
129 {
130 	struct batadv_priv *bat_priv = netdev_priv(dev);
131 	struct batadv_softif_vlan *vlan;
132 	struct sockaddr *addr = p;
133 	u8 old_addr[ETH_ALEN];
134 
135 	if (!is_valid_ether_addr(addr->sa_data))
136 		return -EADDRNOTAVAIL;
137 
138 	ether_addr_copy(old_addr, dev->dev_addr);
139 	ether_addr_copy(dev->dev_addr, addr->sa_data);
140 
141 	/* only modify transtable if it has been initialized before */
142 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
143 		return 0;
144 
145 	rcu_read_lock();
146 	hlist_for_each_entry_rcu(vlan, &bat_priv->softif_vlan_list, list) {
147 		batadv_tt_local_remove(bat_priv, old_addr, vlan->vid,
148 				       "mac address changed", false);
149 		batadv_tt_local_add(dev, addr->sa_data, vlan->vid,
150 				    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
151 	}
152 	rcu_read_unlock();
153 
154 	return 0;
155 }
156 
157 static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
158 {
159 	/* check ranges */
160 	if (new_mtu < 68 || new_mtu > batadv_hardif_min_mtu(dev))
161 		return -EINVAL;
162 
163 	dev->mtu = new_mtu;
164 
165 	return 0;
166 }
167 
168 /**
169  * batadv_interface_set_rx_mode() - set the rx mode of a device
170  * @dev: registered network device to modify
171  *
172  * We do not actually need to set any rx filters for the virtual batman
173  * soft interface. However a dummy handler enables a user to set static
174  * multicast listeners for instance.
175  */
176 static void batadv_interface_set_rx_mode(struct net_device *dev)
177 {
178 }
179 
180 static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
181 				       struct net_device *soft_iface)
182 {
183 	struct ethhdr *ethhdr;
184 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
185 	struct batadv_hard_iface *primary_if = NULL;
186 	struct batadv_bcast_packet *bcast_packet;
187 	static const u8 stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
188 					      0x00, 0x00};
189 	static const u8 ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
190 					       0x00, 0x00};
191 	enum batadv_dhcp_recipient dhcp_rcp = BATADV_DHCP_NO;
192 	u8 *dst_hint = NULL, chaddr[ETH_ALEN];
193 	struct vlan_ethhdr *vhdr;
194 	unsigned int header_len = 0;
195 	int data_len = skb->len, ret;
196 	unsigned long brd_delay = 1;
197 	bool do_bcast = false, client_added;
198 	unsigned short vid;
199 	u32 seqno;
200 	int gw_mode;
201 	enum batadv_forw_mode forw_mode = BATADV_FORW_SINGLE;
202 	struct batadv_orig_node *mcast_single_orig = NULL;
203 	int network_offset = ETH_HLEN;
204 	__be16 proto;
205 
206 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
207 		goto dropped;
208 
209 	/* reset control block to avoid left overs from previous users */
210 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
211 
212 	netif_trans_update(soft_iface);
213 	vid = batadv_get_vid(skb, 0);
214 
215 	skb_reset_mac_header(skb);
216 	ethhdr = eth_hdr(skb);
217 
218 	proto = ethhdr->h_proto;
219 
220 	switch (ntohs(proto)) {
221 	case ETH_P_8021Q:
222 		if (!pskb_may_pull(skb, sizeof(*vhdr)))
223 			goto dropped;
224 		vhdr = vlan_eth_hdr(skb);
225 		proto = vhdr->h_vlan_encapsulated_proto;
226 
227 		/* drop batman-in-batman packets to prevent loops */
228 		if (proto != htons(ETH_P_BATMAN)) {
229 			network_offset += VLAN_HLEN;
230 			break;
231 		}
232 
233 		/* fall through */
234 	case ETH_P_BATMAN:
235 		goto dropped;
236 	}
237 
238 	skb_set_network_header(skb, network_offset);
239 
240 	if (batadv_bla_tx(bat_priv, skb, vid))
241 		goto dropped;
242 
243 	/* skb->data might have been reallocated by batadv_bla_tx() */
244 	ethhdr = eth_hdr(skb);
245 
246 	/* Register the client MAC in the transtable */
247 	if (!is_multicast_ether_addr(ethhdr->h_source) &&
248 	    !batadv_bla_is_loopdetect_mac(ethhdr->h_source)) {
249 		client_added = batadv_tt_local_add(soft_iface, ethhdr->h_source,
250 						   vid, skb->skb_iif,
251 						   skb->mark);
252 		if (!client_added)
253 			goto dropped;
254 	}
255 
256 	/* Snoop address candidates from DHCPACKs for early DAT filling */
257 	batadv_dat_snoop_outgoing_dhcp_ack(bat_priv, skb, proto, vid);
258 
259 	/* don't accept stp packets. STP does not help in meshes.
260 	 * better use the bridge loop avoidance ...
261 	 *
262 	 * The same goes for ECTP sent at least by some Cisco Switches,
263 	 * it might confuse the mesh when used with bridge loop avoidance.
264 	 */
265 	if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
266 		goto dropped;
267 
268 	if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
269 		goto dropped;
270 
271 	gw_mode = atomic_read(&bat_priv->gw.mode);
272 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
273 		/* if gw mode is off, broadcast every packet */
274 		if (gw_mode == BATADV_GW_MODE_OFF) {
275 			do_bcast = true;
276 			goto send;
277 		}
278 
279 		dhcp_rcp = batadv_gw_dhcp_recipient_get(skb, &header_len,
280 							chaddr);
281 		/* skb->data may have been modified by
282 		 * batadv_gw_dhcp_recipient_get()
283 		 */
284 		ethhdr = eth_hdr(skb);
285 		/* if gw_mode is on, broadcast any non-DHCP message.
286 		 * All the DHCP packets are going to be sent as unicast
287 		 */
288 		if (dhcp_rcp == BATADV_DHCP_NO) {
289 			do_bcast = true;
290 			goto send;
291 		}
292 
293 		if (dhcp_rcp == BATADV_DHCP_TO_CLIENT)
294 			dst_hint = chaddr;
295 		else if ((gw_mode == BATADV_GW_MODE_SERVER) &&
296 			 (dhcp_rcp == BATADV_DHCP_TO_SERVER))
297 			/* gateways should not forward any DHCP message if
298 			 * directed to a DHCP server
299 			 */
300 			goto dropped;
301 
302 send:
303 		if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
304 			forw_mode = batadv_mcast_forw_mode(bat_priv, skb,
305 							   &mcast_single_orig);
306 			if (forw_mode == BATADV_FORW_NONE)
307 				goto dropped;
308 
309 			if (forw_mode == BATADV_FORW_SINGLE ||
310 			    forw_mode == BATADV_FORW_SOME)
311 				do_bcast = false;
312 		}
313 	}
314 
315 	batadv_skb_set_priority(skb, 0);
316 
317 	/* ethernet packet should be broadcasted */
318 	if (do_bcast) {
319 		primary_if = batadv_primary_if_get_selected(bat_priv);
320 		if (!primary_if)
321 			goto dropped;
322 
323 		/* in case of ARP request, we do not immediately broadcasti the
324 		 * packet, instead we first wait for DAT to try to retrieve the
325 		 * correct ARP entry
326 		 */
327 		if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
328 			brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
329 
330 		if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
331 			goto dropped;
332 
333 		bcast_packet = (struct batadv_bcast_packet *)skb->data;
334 		bcast_packet->version = BATADV_COMPAT_VERSION;
335 		bcast_packet->ttl = BATADV_TTL;
336 
337 		/* batman packet type: broadcast */
338 		bcast_packet->packet_type = BATADV_BCAST;
339 		bcast_packet->reserved = 0;
340 
341 		/* hw address of first interface is the orig mac because only
342 		 * this mac is known throughout the mesh
343 		 */
344 		ether_addr_copy(bcast_packet->orig,
345 				primary_if->net_dev->dev_addr);
346 
347 		/* set broadcast sequence number */
348 		seqno = atomic_inc_return(&bat_priv->bcast_seqno);
349 		bcast_packet->seqno = htonl(seqno);
350 
351 		batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay, true);
352 
353 		/* a copy is stored in the bcast list, therefore removing
354 		 * the original skb.
355 		 */
356 		consume_skb(skb);
357 
358 	/* unicast packet */
359 	} else {
360 		/* DHCP packets going to a server will use the GW feature */
361 		if (dhcp_rcp == BATADV_DHCP_TO_SERVER) {
362 			ret = batadv_gw_out_of_range(bat_priv, skb);
363 			if (ret)
364 				goto dropped;
365 			ret = batadv_send_skb_via_gw(bat_priv, skb, vid);
366 		} else if (mcast_single_orig) {
367 			ret = batadv_send_skb_unicast(bat_priv, skb,
368 						      BATADV_UNICAST, 0,
369 						      mcast_single_orig, vid);
370 		} else if (forw_mode == BATADV_FORW_SOME) {
371 			ret = batadv_mcast_forw_send(bat_priv, skb, vid);
372 		} else {
373 			if (batadv_dat_snoop_outgoing_arp_request(bat_priv,
374 								  skb))
375 				goto dropped;
376 
377 			batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
378 
379 			ret = batadv_send_skb_via_tt(bat_priv, skb, dst_hint,
380 						     vid);
381 		}
382 		if (ret != NET_XMIT_SUCCESS)
383 			goto dropped_freed;
384 	}
385 
386 	batadv_inc_counter(bat_priv, BATADV_CNT_TX);
387 	batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
388 	goto end;
389 
390 dropped:
391 	kfree_skb(skb);
392 dropped_freed:
393 	batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
394 end:
395 	if (mcast_single_orig)
396 		batadv_orig_node_put(mcast_single_orig);
397 	if (primary_if)
398 		batadv_hardif_put(primary_if);
399 	return NETDEV_TX_OK;
400 }
401 
402 /**
403  * batadv_interface_rx() - receive ethernet frame on local batman-adv interface
404  * @soft_iface: local interface which will receive the ethernet frame
405  * @skb: ethernet frame for @soft_iface
406  * @hdr_size: size of already parsed batman-adv header
407  * @orig_node: originator from which the batman-adv packet was sent
408  *
409  * Sends a ethernet frame to the receive path of the local @soft_iface.
410  * skb->data has still point to the batman-adv header with the size @hdr_size.
411  * The caller has to have parsed this header already and made sure that at least
412  * @hdr_size bytes are still available for pull in @skb.
413  *
414  * The packet may still get dropped. This can happen when the encapsulated
415  * ethernet frame is invalid or contains again an batman-adv packet. Also
416  * unicast packets will be dropped directly when it was sent between two
417  * isolated clients.
418  */
419 void batadv_interface_rx(struct net_device *soft_iface,
420 			 struct sk_buff *skb, int hdr_size,
421 			 struct batadv_orig_node *orig_node)
422 {
423 	struct batadv_bcast_packet *batadv_bcast_packet;
424 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
425 	struct vlan_ethhdr *vhdr;
426 	struct ethhdr *ethhdr;
427 	unsigned short vid;
428 	bool is_bcast;
429 
430 	batadv_bcast_packet = (struct batadv_bcast_packet *)skb->data;
431 	is_bcast = (batadv_bcast_packet->packet_type == BATADV_BCAST);
432 
433 	skb_pull_rcsum(skb, hdr_size);
434 	skb_reset_mac_header(skb);
435 
436 	/* clean the netfilter state now that the batman-adv header has been
437 	 * removed
438 	 */
439 	nf_reset_ct(skb);
440 
441 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
442 		goto dropped;
443 
444 	vid = batadv_get_vid(skb, 0);
445 	ethhdr = eth_hdr(skb);
446 
447 	switch (ntohs(ethhdr->h_proto)) {
448 	case ETH_P_8021Q:
449 		if (!pskb_may_pull(skb, VLAN_ETH_HLEN))
450 			goto dropped;
451 
452 		vhdr = (struct vlan_ethhdr *)skb->data;
453 
454 		/* drop batman-in-batman packets to prevent loops */
455 		if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN))
456 			break;
457 
458 		/* fall through */
459 	case ETH_P_BATMAN:
460 		goto dropped;
461 	}
462 
463 	/* skb->dev & skb->pkt_type are set here */
464 	skb->protocol = eth_type_trans(skb, soft_iface);
465 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
466 
467 	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
468 	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
469 			   skb->len + ETH_HLEN);
470 
471 	/* Let the bridge loop avoidance check the packet. If will
472 	 * not handle it, we can safely push it up.
473 	 */
474 	if (batadv_bla_rx(bat_priv, skb, vid, is_bcast))
475 		goto out;
476 
477 	if (orig_node)
478 		batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
479 						     ethhdr->h_source, vid);
480 
481 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
482 		/* set the mark on broadcast packets if AP isolation is ON and
483 		 * the packet is coming from an "isolated" client
484 		 */
485 		if (batadv_vlan_ap_isola_get(bat_priv, vid) &&
486 		    batadv_tt_global_is_isolated(bat_priv, ethhdr->h_source,
487 						 vid)) {
488 			/* save bits in skb->mark not covered by the mask and
489 			 * apply the mark on the rest
490 			 */
491 			skb->mark &= ~bat_priv->isolation_mark_mask;
492 			skb->mark |= bat_priv->isolation_mark;
493 		}
494 	} else if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source,
495 					 ethhdr->h_dest, vid)) {
496 		goto dropped;
497 	}
498 
499 	netif_rx(skb);
500 	goto out;
501 
502 dropped:
503 	kfree_skb(skb);
504 out:
505 	return;
506 }
507 
508 /**
509  * batadv_softif_vlan_release() - release vlan from lists and queue for free
510  *  after rcu grace period
511  * @ref: kref pointer of the vlan object
512  */
513 static void batadv_softif_vlan_release(struct kref *ref)
514 {
515 	struct batadv_softif_vlan *vlan;
516 
517 	vlan = container_of(ref, struct batadv_softif_vlan, refcount);
518 
519 	spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
520 	hlist_del_rcu(&vlan->list);
521 	spin_unlock_bh(&vlan->bat_priv->softif_vlan_list_lock);
522 
523 	kfree_rcu(vlan, rcu);
524 }
525 
526 /**
527  * batadv_softif_vlan_put() - decrease the vlan object refcounter and
528  *  possibly release it
529  * @vlan: the vlan object to release
530  */
531 void batadv_softif_vlan_put(struct batadv_softif_vlan *vlan)
532 {
533 	if (!vlan)
534 		return;
535 
536 	kref_put(&vlan->refcount, batadv_softif_vlan_release);
537 }
538 
539 /**
540  * batadv_softif_vlan_get() - get the vlan object for a specific vid
541  * @bat_priv: the bat priv with all the soft interface information
542  * @vid: the identifier of the vlan object to retrieve
543  *
544  * Return: the private data of the vlan matching the vid passed as argument or
545  * NULL otherwise. The refcounter of the returned object is incremented by 1.
546  */
547 struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv,
548 						  unsigned short vid)
549 {
550 	struct batadv_softif_vlan *vlan_tmp, *vlan = NULL;
551 
552 	rcu_read_lock();
553 	hlist_for_each_entry_rcu(vlan_tmp, &bat_priv->softif_vlan_list, list) {
554 		if (vlan_tmp->vid != vid)
555 			continue;
556 
557 		if (!kref_get_unless_zero(&vlan_tmp->refcount))
558 			continue;
559 
560 		vlan = vlan_tmp;
561 		break;
562 	}
563 	rcu_read_unlock();
564 
565 	return vlan;
566 }
567 
568 /**
569  * batadv_softif_create_vlan() - allocate the needed resources for a new vlan
570  * @bat_priv: the bat priv with all the soft interface information
571  * @vid: the VLAN identifier
572  *
573  * Return: 0 on success, a negative error otherwise.
574  */
575 int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
576 {
577 	struct batadv_softif_vlan *vlan;
578 	int err;
579 
580 	spin_lock_bh(&bat_priv->softif_vlan_list_lock);
581 
582 	vlan = batadv_softif_vlan_get(bat_priv, vid);
583 	if (vlan) {
584 		batadv_softif_vlan_put(vlan);
585 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
586 		return -EEXIST;
587 	}
588 
589 	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
590 	if (!vlan) {
591 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
592 		return -ENOMEM;
593 	}
594 
595 	vlan->bat_priv = bat_priv;
596 	vlan->vid = vid;
597 	kref_init(&vlan->refcount);
598 
599 	atomic_set(&vlan->ap_isolation, 0);
600 
601 	kref_get(&vlan->refcount);
602 	hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
603 	spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
604 
605 	/* batadv_sysfs_add_vlan cannot be in the spinlock section due to the
606 	 * sleeping behavior of the sysfs functions and the fs_reclaim lock
607 	 */
608 	err = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
609 	if (err) {
610 		/* ref for the function */
611 		batadv_softif_vlan_put(vlan);
612 
613 		/* ref for the list */
614 		batadv_softif_vlan_put(vlan);
615 		return err;
616 	}
617 
618 	/* add a new TT local entry. This one will be marked with the NOPURGE
619 	 * flag
620 	 */
621 	batadv_tt_local_add(bat_priv->soft_iface,
622 			    bat_priv->soft_iface->dev_addr, vid,
623 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
624 
625 	/* don't return reference to new softif_vlan */
626 	batadv_softif_vlan_put(vlan);
627 
628 	return 0;
629 }
630 
631 /**
632  * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object
633  * @bat_priv: the bat priv with all the soft interface information
634  * @vlan: the object to remove
635  */
636 static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
637 				       struct batadv_softif_vlan *vlan)
638 {
639 	/* explicitly remove the associated TT local entry because it is marked
640 	 * with the NOPURGE flag
641 	 */
642 	batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
643 			       vlan->vid, "vlan interface destroyed", false);
644 
645 	batadv_sysfs_del_vlan(bat_priv, vlan);
646 	batadv_softif_vlan_put(vlan);
647 }
648 
649 /**
650  * batadv_interface_add_vid() - ndo_add_vid API implementation
651  * @dev: the netdev of the mesh interface
652  * @proto: protocol of the the vlan id
653  * @vid: identifier of the new vlan
654  *
655  * Set up all the internal structures for handling the new vlan on top of the
656  * mesh interface
657  *
658  * Return: 0 on success or a negative error code in case of failure.
659  */
660 static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
661 				    unsigned short vid)
662 {
663 	struct batadv_priv *bat_priv = netdev_priv(dev);
664 	struct batadv_softif_vlan *vlan;
665 	int ret;
666 
667 	/* only 802.1Q vlans are supported.
668 	 * batman-adv does not know how to handle other types
669 	 */
670 	if (proto != htons(ETH_P_8021Q))
671 		return -EINVAL;
672 
673 	vid |= BATADV_VLAN_HAS_TAG;
674 
675 	/* if a new vlan is getting created and it already exists, it means that
676 	 * it was not deleted yet. batadv_softif_vlan_get() increases the
677 	 * refcount in order to revive the object.
678 	 *
679 	 * if it does not exist then create it.
680 	 */
681 	vlan = batadv_softif_vlan_get(bat_priv, vid);
682 	if (!vlan)
683 		return batadv_softif_create_vlan(bat_priv, vid);
684 
685 	/* recreate the sysfs object if it was already destroyed (and it should
686 	 * be since we received a kill_vid() for this vlan
687 	 */
688 	if (!vlan->kobj) {
689 		ret = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
690 		if (ret) {
691 			batadv_softif_vlan_put(vlan);
692 			return ret;
693 		}
694 	}
695 
696 	/* add a new TT local entry. This one will be marked with the NOPURGE
697 	 * flag. This must be added again, even if the vlan object already
698 	 * exists, because the entry was deleted by kill_vid()
699 	 */
700 	batadv_tt_local_add(bat_priv->soft_iface,
701 			    bat_priv->soft_iface->dev_addr, vid,
702 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
703 
704 	return 0;
705 }
706 
707 /**
708  * batadv_interface_kill_vid() - ndo_kill_vid API implementation
709  * @dev: the netdev of the mesh interface
710  * @proto: protocol of the the vlan id
711  * @vid: identifier of the deleted vlan
712  *
713  * Destroy all the internal structures used to handle the vlan identified by vid
714  * on top of the mesh interface
715  *
716  * Return: 0 on success, -EINVAL if the specified prototype is not ETH_P_8021Q
717  * or -ENOENT if the specified vlan id wasn't registered.
718  */
719 static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
720 				     unsigned short vid)
721 {
722 	struct batadv_priv *bat_priv = netdev_priv(dev);
723 	struct batadv_softif_vlan *vlan;
724 
725 	/* only 802.1Q vlans are supported. batman-adv does not know how to
726 	 * handle other types
727 	 */
728 	if (proto != htons(ETH_P_8021Q))
729 		return -EINVAL;
730 
731 	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
732 	if (!vlan)
733 		return -ENOENT;
734 
735 	batadv_softif_destroy_vlan(bat_priv, vlan);
736 
737 	/* finally free the vlan object */
738 	batadv_softif_vlan_put(vlan);
739 
740 	return 0;
741 }
742 
743 /**
744  * batadv_softif_init_late() - late stage initialization of soft interface
745  * @dev: registered network device to modify
746  *
747  * Return: error code on failures
748  */
749 static int batadv_softif_init_late(struct net_device *dev)
750 {
751 	struct batadv_priv *bat_priv;
752 	u32 random_seqno;
753 	int ret;
754 	size_t cnt_len = sizeof(u64) * BATADV_CNT_NUM;
755 
756 	bat_priv = netdev_priv(dev);
757 	bat_priv->soft_iface = dev;
758 
759 	/* batadv_interface_stats() needs to be available as soon as
760 	 * register_netdevice() has been called
761 	 */
762 	bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(u64));
763 	if (!bat_priv->bat_counters)
764 		return -ENOMEM;
765 
766 	atomic_set(&bat_priv->aggregated_ogms, 1);
767 	atomic_set(&bat_priv->bonding, 0);
768 #ifdef CONFIG_BATMAN_ADV_BLA
769 	atomic_set(&bat_priv->bridge_loop_avoidance, 1);
770 #endif
771 #ifdef CONFIG_BATMAN_ADV_DAT
772 	atomic_set(&bat_priv->distributed_arp_table, 1);
773 #endif
774 #ifdef CONFIG_BATMAN_ADV_MCAST
775 	atomic_set(&bat_priv->multicast_mode, 1);
776 	atomic_set(&bat_priv->multicast_fanout, 16);
777 	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);
778 	atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0);
779 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
780 #endif
781 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
782 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
783 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
784 	atomic_set(&bat_priv->orig_interval, 1000);
785 	atomic_set(&bat_priv->hop_penalty, 30);
786 #ifdef CONFIG_BATMAN_ADV_DEBUG
787 	atomic_set(&bat_priv->log_level, 0);
788 #endif
789 	atomic_set(&bat_priv->fragmentation, 1);
790 	atomic_set(&bat_priv->packet_size_max, ETH_DATA_LEN);
791 	atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
792 	atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
793 
794 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
795 	atomic_set(&bat_priv->bcast_seqno, 1);
796 	atomic_set(&bat_priv->tt.vn, 0);
797 	atomic_set(&bat_priv->tt.local_changes, 0);
798 	atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
799 #ifdef CONFIG_BATMAN_ADV_BLA
800 	atomic_set(&bat_priv->bla.num_requests, 0);
801 #endif
802 	atomic_set(&bat_priv->tp_num, 0);
803 
804 	bat_priv->tt.last_changeset = NULL;
805 	bat_priv->tt.last_changeset_len = 0;
806 	bat_priv->isolation_mark = 0;
807 	bat_priv->isolation_mark_mask = 0;
808 
809 	/* randomize initial seqno to avoid collision */
810 	get_random_bytes(&random_seqno, sizeof(random_seqno));
811 	atomic_set(&bat_priv->frag_seqno, random_seqno);
812 
813 	bat_priv->primary_if = NULL;
814 
815 	batadv_nc_init_bat_priv(bat_priv);
816 
817 	ret = batadv_algo_select(bat_priv, batadv_routing_algo);
818 	if (ret < 0)
819 		goto free_bat_counters;
820 
821 	ret = batadv_debugfs_add_meshif(dev);
822 	if (ret < 0)
823 		goto free_bat_counters;
824 
825 	ret = batadv_mesh_init(dev);
826 	if (ret < 0)
827 		goto unreg_debugfs;
828 
829 	return 0;
830 
831 unreg_debugfs:
832 	batadv_debugfs_del_meshif(dev);
833 free_bat_counters:
834 	free_percpu(bat_priv->bat_counters);
835 	bat_priv->bat_counters = NULL;
836 
837 	return ret;
838 }
839 
840 /**
841  * batadv_softif_slave_add() - Add a slave interface to a batadv_soft_interface
842  * @dev: batadv_soft_interface used as master interface
843  * @slave_dev: net_device which should become the slave interface
844  * @extack: extended ACK report struct
845  *
846  * Return: 0 if successful or error otherwise.
847  */
848 static int batadv_softif_slave_add(struct net_device *dev,
849 				   struct net_device *slave_dev,
850 				   struct netlink_ext_ack *extack)
851 {
852 	struct batadv_hard_iface *hard_iface;
853 	struct net *net = dev_net(dev);
854 	int ret = -EINVAL;
855 
856 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
857 	if (!hard_iface || hard_iface->soft_iface)
858 		goto out;
859 
860 	ret = batadv_hardif_enable_interface(hard_iface, net, dev->name);
861 
862 out:
863 	if (hard_iface)
864 		batadv_hardif_put(hard_iface);
865 	return ret;
866 }
867 
868 /**
869  * batadv_softif_slave_del() - Delete a slave iface from a batadv_soft_interface
870  * @dev: batadv_soft_interface used as master interface
871  * @slave_dev: net_device which should be removed from the master interface
872  *
873  * Return: 0 if successful or error otherwise.
874  */
875 static int batadv_softif_slave_del(struct net_device *dev,
876 				   struct net_device *slave_dev)
877 {
878 	struct batadv_hard_iface *hard_iface;
879 	int ret = -EINVAL;
880 
881 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
882 
883 	if (!hard_iface || hard_iface->soft_iface != dev)
884 		goto out;
885 
886 	batadv_hardif_disable_interface(hard_iface, BATADV_IF_CLEANUP_KEEP);
887 	ret = 0;
888 
889 out:
890 	if (hard_iface)
891 		batadv_hardif_put(hard_iface);
892 	return ret;
893 }
894 
895 static const struct net_device_ops batadv_netdev_ops = {
896 	.ndo_init = batadv_softif_init_late,
897 	.ndo_open = batadv_interface_open,
898 	.ndo_stop = batadv_interface_release,
899 	.ndo_get_stats = batadv_interface_stats,
900 	.ndo_vlan_rx_add_vid = batadv_interface_add_vid,
901 	.ndo_vlan_rx_kill_vid = batadv_interface_kill_vid,
902 	.ndo_set_mac_address = batadv_interface_set_mac_addr,
903 	.ndo_change_mtu = batadv_interface_change_mtu,
904 	.ndo_set_rx_mode = batadv_interface_set_rx_mode,
905 	.ndo_start_xmit = batadv_interface_tx,
906 	.ndo_validate_addr = eth_validate_addr,
907 	.ndo_add_slave = batadv_softif_slave_add,
908 	.ndo_del_slave = batadv_softif_slave_del,
909 };
910 
911 static void batadv_get_drvinfo(struct net_device *dev,
912 			       struct ethtool_drvinfo *info)
913 {
914 	strscpy(info->driver, "B.A.T.M.A.N. advanced", sizeof(info->driver));
915 	strscpy(info->version, BATADV_SOURCE_VERSION, sizeof(info->version));
916 	strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
917 	strscpy(info->bus_info, "batman", sizeof(info->bus_info));
918 }
919 
920 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
921  * Declare each description string in struct.name[] to get fixed sized buffer
922  * and compile time checking for strings longer than ETH_GSTRING_LEN.
923  */
924 static const struct {
925 	const char name[ETH_GSTRING_LEN];
926 } batadv_counters_strings[] = {
927 	{ "tx" },
928 	{ "tx_bytes" },
929 	{ "tx_dropped" },
930 	{ "rx" },
931 	{ "rx_bytes" },
932 	{ "forward" },
933 	{ "forward_bytes" },
934 	{ "mgmt_tx" },
935 	{ "mgmt_tx_bytes" },
936 	{ "mgmt_rx" },
937 	{ "mgmt_rx_bytes" },
938 	{ "frag_tx" },
939 	{ "frag_tx_bytes" },
940 	{ "frag_rx" },
941 	{ "frag_rx_bytes" },
942 	{ "frag_fwd" },
943 	{ "frag_fwd_bytes" },
944 	{ "tt_request_tx" },
945 	{ "tt_request_rx" },
946 	{ "tt_response_tx" },
947 	{ "tt_response_rx" },
948 	{ "tt_roam_adv_tx" },
949 	{ "tt_roam_adv_rx" },
950 #ifdef CONFIG_BATMAN_ADV_DAT
951 	{ "dat_get_tx" },
952 	{ "dat_get_rx" },
953 	{ "dat_put_tx" },
954 	{ "dat_put_rx" },
955 	{ "dat_cached_reply_tx" },
956 #endif
957 #ifdef CONFIG_BATMAN_ADV_NC
958 	{ "nc_code" },
959 	{ "nc_code_bytes" },
960 	{ "nc_recode" },
961 	{ "nc_recode_bytes" },
962 	{ "nc_buffer" },
963 	{ "nc_decode" },
964 	{ "nc_decode_bytes" },
965 	{ "nc_decode_failed" },
966 	{ "nc_sniffed" },
967 #endif
968 };
969 
970 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data)
971 {
972 	if (stringset == ETH_SS_STATS)
973 		memcpy(data, batadv_counters_strings,
974 		       sizeof(batadv_counters_strings));
975 }
976 
977 static void batadv_get_ethtool_stats(struct net_device *dev,
978 				     struct ethtool_stats *stats, u64 *data)
979 {
980 	struct batadv_priv *bat_priv = netdev_priv(dev);
981 	int i;
982 
983 	for (i = 0; i < BATADV_CNT_NUM; i++)
984 		data[i] = batadv_sum_counter(bat_priv, i);
985 }
986 
987 static int batadv_get_sset_count(struct net_device *dev, int stringset)
988 {
989 	if (stringset == ETH_SS_STATS)
990 		return BATADV_CNT_NUM;
991 
992 	return -EOPNOTSUPP;
993 }
994 
995 static const struct ethtool_ops batadv_ethtool_ops = {
996 	.get_drvinfo = batadv_get_drvinfo,
997 	.get_link = ethtool_op_get_link,
998 	.get_strings = batadv_get_strings,
999 	.get_ethtool_stats = batadv_get_ethtool_stats,
1000 	.get_sset_count = batadv_get_sset_count,
1001 };
1002 
1003 /**
1004  * batadv_softif_free() - Deconstructor of batadv_soft_interface
1005  * @dev: Device to cleanup and remove
1006  */
1007 static void batadv_softif_free(struct net_device *dev)
1008 {
1009 	batadv_debugfs_del_meshif(dev);
1010 	batadv_mesh_free(dev);
1011 
1012 	/* some scheduled RCU callbacks need the bat_priv struct to accomplish
1013 	 * their tasks. Wait for them all to be finished before freeing the
1014 	 * netdev and its private data (bat_priv)
1015 	 */
1016 	rcu_barrier();
1017 }
1018 
1019 /**
1020  * batadv_softif_init_early() - early stage initialization of soft interface
1021  * @dev: registered network device to modify
1022  */
1023 static void batadv_softif_init_early(struct net_device *dev)
1024 {
1025 	ether_setup(dev);
1026 
1027 	dev->netdev_ops = &batadv_netdev_ops;
1028 	dev->needs_free_netdev = true;
1029 	dev->priv_destructor = batadv_softif_free;
1030 	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_NETNS_LOCAL;
1031 	dev->features |= NETIF_F_LLTX;
1032 	dev->priv_flags |= IFF_NO_QUEUE;
1033 
1034 	/* can't call min_mtu, because the needed variables
1035 	 * have not been initialized yet
1036 	 */
1037 	dev->mtu = ETH_DATA_LEN;
1038 
1039 	/* generate random address */
1040 	eth_hw_addr_random(dev);
1041 
1042 	dev->ethtool_ops = &batadv_ethtool_ops;
1043 }
1044 
1045 /**
1046  * batadv_softif_create() - Create and register soft interface
1047  * @net: the applicable net namespace
1048  * @name: name of the new soft interface
1049  *
1050  * Return: newly allocated soft_interface, NULL on errors
1051  */
1052 struct net_device *batadv_softif_create(struct net *net, const char *name)
1053 {
1054 	struct net_device *soft_iface;
1055 	int ret;
1056 
1057 	soft_iface = alloc_netdev(sizeof(struct batadv_priv), name,
1058 				  NET_NAME_UNKNOWN, batadv_softif_init_early);
1059 	if (!soft_iface)
1060 		return NULL;
1061 
1062 	dev_net_set(soft_iface, net);
1063 
1064 	soft_iface->rtnl_link_ops = &batadv_link_ops;
1065 
1066 	ret = register_netdevice(soft_iface);
1067 	if (ret < 0) {
1068 		pr_err("Unable to register the batman interface '%s': %i\n",
1069 		       name, ret);
1070 		free_netdev(soft_iface);
1071 		return NULL;
1072 	}
1073 
1074 	return soft_iface;
1075 }
1076 
1077 /**
1078  * batadv_softif_destroy_sysfs() - deletion of batadv_soft_interface via sysfs
1079  * @soft_iface: the to-be-removed batman-adv interface
1080  */
1081 void batadv_softif_destroy_sysfs(struct net_device *soft_iface)
1082 {
1083 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
1084 	struct batadv_softif_vlan *vlan;
1085 
1086 	ASSERT_RTNL();
1087 
1088 	/* destroy the "untagged" VLAN */
1089 	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1090 	if (vlan) {
1091 		batadv_softif_destroy_vlan(bat_priv, vlan);
1092 		batadv_softif_vlan_put(vlan);
1093 	}
1094 
1095 	batadv_sysfs_del_meshif(soft_iface);
1096 	unregister_netdevice(soft_iface);
1097 }
1098 
1099 /**
1100  * batadv_softif_destroy_netlink() - deletion of batadv_soft_interface via
1101  *  netlink
1102  * @soft_iface: the to-be-removed batman-adv interface
1103  * @head: list pointer
1104  */
1105 static void batadv_softif_destroy_netlink(struct net_device *soft_iface,
1106 					  struct list_head *head)
1107 {
1108 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
1109 	struct batadv_hard_iface *hard_iface;
1110 	struct batadv_softif_vlan *vlan;
1111 
1112 	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {
1113 		if (hard_iface->soft_iface == soft_iface)
1114 			batadv_hardif_disable_interface(hard_iface,
1115 							BATADV_IF_CLEANUP_KEEP);
1116 	}
1117 
1118 	/* destroy the "untagged" VLAN */
1119 	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1120 	if (vlan) {
1121 		batadv_softif_destroy_vlan(bat_priv, vlan);
1122 		batadv_softif_vlan_put(vlan);
1123 	}
1124 
1125 	batadv_sysfs_del_meshif(soft_iface);
1126 	unregister_netdevice_queue(soft_iface, head);
1127 }
1128 
1129 /**
1130  * batadv_softif_is_valid() - Check whether device is a batadv soft interface
1131  * @net_dev: device which should be checked
1132  *
1133  * Return: true when net_dev is a batman-adv interface, false otherwise
1134  */
1135 bool batadv_softif_is_valid(const struct net_device *net_dev)
1136 {
1137 	if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
1138 		return true;
1139 
1140 	return false;
1141 }
1142 
1143 struct rtnl_link_ops batadv_link_ops __read_mostly = {
1144 	.kind		= "batadv",
1145 	.priv_size	= sizeof(struct batadv_priv),
1146 	.setup		= batadv_softif_init_early,
1147 	.dellink	= batadv_softif_destroy_netlink,
1148 };
1149