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/printk.h>
30 #include <linux/random.h>
31 #include <linux/rculist.h>
32 #include <linux/rcupdate.h>
33 #include <linux/skbuff.h>
34 #include <linux/slab.h>
35 #include <linux/socket.h>
36 #include <linux/spinlock.h>
37 #include <linux/stddef.h>
38 #include <linux/string.h>
39 #include <linux/types.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 = 1;
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;
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_add_bcast_packet_to_list(bat_priv, skb, brd_delay, true);
350 
351 		/* a copy is stored in the bcast list, therefore removing
352 		 * the original skb.
353 		 */
354 		consume_skb(skb);
355 
356 	/* unicast packet */
357 	} else {
358 		/* DHCP packets going to a server will use the GW feature */
359 		if (dhcp_rcp == BATADV_DHCP_TO_SERVER) {
360 			ret = batadv_gw_out_of_range(bat_priv, skb);
361 			if (ret)
362 				goto dropped;
363 			ret = batadv_send_skb_via_gw(bat_priv, skb, vid);
364 		} else if (mcast_single_orig) {
365 			ret = batadv_mcast_forw_send_orig(bat_priv, skb, vid,
366 							  mcast_single_orig);
367 		} else if (forw_mode == BATADV_FORW_SOME) {
368 			ret = batadv_mcast_forw_send(bat_priv, skb, vid);
369 		} else {
370 			if (batadv_dat_snoop_outgoing_arp_request(bat_priv,
371 								  skb))
372 				goto dropped;
373 
374 			batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
375 
376 			ret = batadv_send_skb_via_tt(bat_priv, skb, dst_hint,
377 						     vid);
378 		}
379 		if (ret != NET_XMIT_SUCCESS)
380 			goto dropped_freed;
381 	}
382 
383 	batadv_inc_counter(bat_priv, BATADV_CNT_TX);
384 	batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
385 	goto end;
386 
387 dropped:
388 	kfree_skb(skb);
389 dropped_freed:
390 	batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
391 end:
392 	if (mcast_single_orig)
393 		batadv_orig_node_put(mcast_single_orig);
394 	if (primary_if)
395 		batadv_hardif_put(primary_if);
396 	return NETDEV_TX_OK;
397 }
398 
399 /**
400  * batadv_interface_rx() - receive ethernet frame on local batman-adv interface
401  * @soft_iface: local interface which will receive the ethernet frame
402  * @skb: ethernet frame for @soft_iface
403  * @hdr_size: size of already parsed batman-adv header
404  * @orig_node: originator from which the batman-adv packet was sent
405  *
406  * Sends an ethernet frame to the receive path of the local @soft_iface.
407  * skb->data has still point to the batman-adv header with the size @hdr_size.
408  * The caller has to have parsed this header already and made sure that at least
409  * @hdr_size bytes are still available for pull in @skb.
410  *
411  * The packet may still get dropped. This can happen when the encapsulated
412  * ethernet frame is invalid or contains again an batman-adv packet. Also
413  * unicast packets will be dropped directly when it was sent between two
414  * isolated clients.
415  */
416 void batadv_interface_rx(struct net_device *soft_iface,
417 			 struct sk_buff *skb, int hdr_size,
418 			 struct batadv_orig_node *orig_node)
419 {
420 	struct batadv_bcast_packet *batadv_bcast_packet;
421 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
422 	struct vlan_ethhdr *vhdr;
423 	struct ethhdr *ethhdr;
424 	unsigned short vid;
425 	int packet_type;
426 
427 	batadv_bcast_packet = (struct batadv_bcast_packet *)skb->data;
428 	packet_type = batadv_bcast_packet->packet_type;
429 
430 	skb_pull_rcsum(skb, hdr_size);
431 	skb_reset_mac_header(skb);
432 
433 	/* clean the netfilter state now that the batman-adv header has been
434 	 * removed
435 	 */
436 	nf_reset_ct(skb);
437 
438 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
439 		goto dropped;
440 
441 	vid = batadv_get_vid(skb, 0);
442 	ethhdr = eth_hdr(skb);
443 
444 	switch (ntohs(ethhdr->h_proto)) {
445 	case ETH_P_8021Q:
446 		if (!pskb_may_pull(skb, VLAN_ETH_HLEN))
447 			goto dropped;
448 
449 		vhdr = (struct vlan_ethhdr *)skb->data;
450 
451 		/* drop batman-in-batman packets to prevent loops */
452 		if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN))
453 			break;
454 
455 		fallthrough;
456 	case ETH_P_BATMAN:
457 		goto dropped;
458 	}
459 
460 	/* skb->dev & skb->pkt_type are set here */
461 	skb->protocol = eth_type_trans(skb, soft_iface);
462 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
463 
464 	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
465 	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
466 			   skb->len + ETH_HLEN);
467 
468 	/* Let the bridge loop avoidance check the packet. If will
469 	 * not handle it, we can safely push it up.
470 	 */
471 	if (batadv_bla_rx(bat_priv, skb, vid, packet_type))
472 		goto out;
473 
474 	if (orig_node)
475 		batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
476 						     ethhdr->h_source, vid);
477 
478 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
479 		/* set the mark on broadcast packets if AP isolation is ON and
480 		 * the packet is coming from an "isolated" client
481 		 */
482 		if (batadv_vlan_ap_isola_get(bat_priv, vid) &&
483 		    batadv_tt_global_is_isolated(bat_priv, ethhdr->h_source,
484 						 vid)) {
485 			/* save bits in skb->mark not covered by the mask and
486 			 * apply the mark on the rest
487 			 */
488 			skb->mark &= ~bat_priv->isolation_mark_mask;
489 			skb->mark |= bat_priv->isolation_mark;
490 		}
491 	} else if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source,
492 					 ethhdr->h_dest, vid)) {
493 		goto dropped;
494 	}
495 
496 	netif_rx(skb);
497 	goto out;
498 
499 dropped:
500 	kfree_skb(skb);
501 out:
502 	return;
503 }
504 
505 /**
506  * batadv_softif_vlan_release() - release vlan from lists and queue for free
507  *  after rcu grace period
508  * @ref: kref pointer of the vlan object
509  */
510 static void batadv_softif_vlan_release(struct kref *ref)
511 {
512 	struct batadv_softif_vlan *vlan;
513 
514 	vlan = container_of(ref, struct batadv_softif_vlan, refcount);
515 
516 	spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
517 	hlist_del_rcu(&vlan->list);
518 	spin_unlock_bh(&vlan->bat_priv->softif_vlan_list_lock);
519 
520 	kfree_rcu(vlan, rcu);
521 }
522 
523 /**
524  * batadv_softif_vlan_put() - decrease the vlan object refcounter and
525  *  possibly release it
526  * @vlan: the vlan object to release
527  */
528 void batadv_softif_vlan_put(struct batadv_softif_vlan *vlan)
529 {
530 	if (!vlan)
531 		return;
532 
533 	kref_put(&vlan->refcount, batadv_softif_vlan_release);
534 }
535 
536 /**
537  * batadv_softif_vlan_get() - get the vlan object for a specific vid
538  * @bat_priv: the bat priv with all the soft interface information
539  * @vid: the identifier of the vlan object to retrieve
540  *
541  * Return: the private data of the vlan matching the vid passed as argument or
542  * NULL otherwise. The refcounter of the returned object is incremented by 1.
543  */
544 struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv,
545 						  unsigned short vid)
546 {
547 	struct batadv_softif_vlan *vlan_tmp, *vlan = NULL;
548 
549 	rcu_read_lock();
550 	hlist_for_each_entry_rcu(vlan_tmp, &bat_priv->softif_vlan_list, list) {
551 		if (vlan_tmp->vid != vid)
552 			continue;
553 
554 		if (!kref_get_unless_zero(&vlan_tmp->refcount))
555 			continue;
556 
557 		vlan = vlan_tmp;
558 		break;
559 	}
560 	rcu_read_unlock();
561 
562 	return vlan;
563 }
564 
565 /**
566  * batadv_softif_create_vlan() - allocate the needed resources for a new vlan
567  * @bat_priv: the bat priv with all the soft interface information
568  * @vid: the VLAN identifier
569  *
570  * Return: 0 on success, a negative error otherwise.
571  */
572 int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
573 {
574 	struct batadv_softif_vlan *vlan;
575 
576 	spin_lock_bh(&bat_priv->softif_vlan_list_lock);
577 
578 	vlan = batadv_softif_vlan_get(bat_priv, vid);
579 	if (vlan) {
580 		batadv_softif_vlan_put(vlan);
581 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
582 		return -EEXIST;
583 	}
584 
585 	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
586 	if (!vlan) {
587 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
588 		return -ENOMEM;
589 	}
590 
591 	vlan->bat_priv = bat_priv;
592 	vlan->vid = vid;
593 	kref_init(&vlan->refcount);
594 
595 	atomic_set(&vlan->ap_isolation, 0);
596 
597 	kref_get(&vlan->refcount);
598 	hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
599 	spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
600 
601 	/* add a new TT local entry. This one will be marked with the NOPURGE
602 	 * flag
603 	 */
604 	batadv_tt_local_add(bat_priv->soft_iface,
605 			    bat_priv->soft_iface->dev_addr, vid,
606 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
607 
608 	/* don't return reference to new softif_vlan */
609 	batadv_softif_vlan_put(vlan);
610 
611 	return 0;
612 }
613 
614 /**
615  * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object
616  * @bat_priv: the bat priv with all the soft interface information
617  * @vlan: the object to remove
618  */
619 static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
620 				       struct batadv_softif_vlan *vlan)
621 {
622 	/* explicitly remove the associated TT local entry because it is marked
623 	 * with the NOPURGE flag
624 	 */
625 	batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
626 			       vlan->vid, "vlan interface destroyed", false);
627 
628 	batadv_softif_vlan_put(vlan);
629 }
630 
631 /**
632  * batadv_interface_add_vid() - ndo_add_vid API implementation
633  * @dev: the netdev of the mesh interface
634  * @proto: protocol of the vlan id
635  * @vid: identifier of the new vlan
636  *
637  * Set up all the internal structures for handling the new vlan on top of the
638  * mesh interface
639  *
640  * Return: 0 on success or a negative error code in case of failure.
641  */
642 static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
643 				    unsigned short vid)
644 {
645 	struct batadv_priv *bat_priv = netdev_priv(dev);
646 	struct batadv_softif_vlan *vlan;
647 
648 	/* only 802.1Q vlans are supported.
649 	 * batman-adv does not know how to handle other types
650 	 */
651 	if (proto != htons(ETH_P_8021Q))
652 		return -EINVAL;
653 
654 	vid |= BATADV_VLAN_HAS_TAG;
655 
656 	/* if a new vlan is getting created and it already exists, it means that
657 	 * it was not deleted yet. batadv_softif_vlan_get() increases the
658 	 * refcount in order to revive the object.
659 	 *
660 	 * if it does not exist then create it.
661 	 */
662 	vlan = batadv_softif_vlan_get(bat_priv, vid);
663 	if (!vlan)
664 		return batadv_softif_create_vlan(bat_priv, vid);
665 
666 	/* add a new TT local entry. This one will be marked with the NOPURGE
667 	 * flag. This must be added again, even if the vlan object already
668 	 * exists, because the entry was deleted by kill_vid()
669 	 */
670 	batadv_tt_local_add(bat_priv->soft_iface,
671 			    bat_priv->soft_iface->dev_addr, vid,
672 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
673 
674 	return 0;
675 }
676 
677 /**
678  * batadv_interface_kill_vid() - ndo_kill_vid API implementation
679  * @dev: the netdev of the mesh interface
680  * @proto: protocol of the vlan id
681  * @vid: identifier of the deleted vlan
682  *
683  * Destroy all the internal structures used to handle the vlan identified by vid
684  * on top of the mesh interface
685  *
686  * Return: 0 on success, -EINVAL if the specified prototype is not ETH_P_8021Q
687  * or -ENOENT if the specified vlan id wasn't registered.
688  */
689 static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
690 				     unsigned short vid)
691 {
692 	struct batadv_priv *bat_priv = netdev_priv(dev);
693 	struct batadv_softif_vlan *vlan;
694 
695 	/* only 802.1Q vlans are supported. batman-adv does not know how to
696 	 * handle other types
697 	 */
698 	if (proto != htons(ETH_P_8021Q))
699 		return -EINVAL;
700 
701 	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
702 	if (!vlan)
703 		return -ENOENT;
704 
705 	batadv_softif_destroy_vlan(bat_priv, vlan);
706 
707 	/* finally free the vlan object */
708 	batadv_softif_vlan_put(vlan);
709 
710 	return 0;
711 }
712 
713 /* batman-adv network devices have devices nesting below it and are a special
714  * "super class" of normal network devices; split their locks off into a
715  * separate class since they always nest.
716  */
717 static struct lock_class_key batadv_netdev_xmit_lock_key;
718 static struct lock_class_key batadv_netdev_addr_lock_key;
719 
720 /**
721  * batadv_set_lockdep_class_one() - Set lockdep class for a single tx queue
722  * @dev: device which owns the tx queue
723  * @txq: tx queue to modify
724  * @_unused: always NULL
725  */
726 static void batadv_set_lockdep_class_one(struct net_device *dev,
727 					 struct netdev_queue *txq,
728 					 void *_unused)
729 {
730 	lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
731 }
732 
733 /**
734  * batadv_set_lockdep_class() - Set txq and addr_list lockdep class
735  * @dev: network device to modify
736  */
737 static void batadv_set_lockdep_class(struct net_device *dev)
738 {
739 	lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
740 	netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
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 	batadv_set_lockdep_class(dev);
757 
758 	bat_priv = netdev_priv(dev);
759 	bat_priv->soft_iface = dev;
760 
761 	/* batadv_interface_stats() needs to be available as soon as
762 	 * register_netdevice() has been called
763 	 */
764 	bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(u64));
765 	if (!bat_priv->bat_counters)
766 		return -ENOMEM;
767 
768 	atomic_set(&bat_priv->aggregated_ogms, 1);
769 	atomic_set(&bat_priv->bonding, 0);
770 #ifdef CONFIG_BATMAN_ADV_BLA
771 	atomic_set(&bat_priv->bridge_loop_avoidance, 1);
772 #endif
773 #ifdef CONFIG_BATMAN_ADV_DAT
774 	atomic_set(&bat_priv->distributed_arp_table, 1);
775 #endif
776 #ifdef CONFIG_BATMAN_ADV_MCAST
777 	atomic_set(&bat_priv->multicast_mode, 1);
778 	atomic_set(&bat_priv->multicast_fanout, 16);
779 	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);
780 	atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0);
781 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
782 #endif
783 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
784 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
785 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
786 	atomic_set(&bat_priv->orig_interval, 1000);
787 	atomic_set(&bat_priv->hop_penalty, 30);
788 #ifdef CONFIG_BATMAN_ADV_DEBUG
789 	atomic_set(&bat_priv->log_level, 0);
790 #endif
791 	atomic_set(&bat_priv->fragmentation, 1);
792 	atomic_set(&bat_priv->packet_size_max, ETH_DATA_LEN);
793 	atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
794 	atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
795 
796 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
797 	atomic_set(&bat_priv->bcast_seqno, 1);
798 	atomic_set(&bat_priv->tt.vn, 0);
799 	atomic_set(&bat_priv->tt.local_changes, 0);
800 	atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
801 #ifdef CONFIG_BATMAN_ADV_BLA
802 	atomic_set(&bat_priv->bla.num_requests, 0);
803 #endif
804 	atomic_set(&bat_priv->tp_num, 0);
805 
806 	bat_priv->tt.last_changeset = NULL;
807 	bat_priv->tt.last_changeset_len = 0;
808 	bat_priv->isolation_mark = 0;
809 	bat_priv->isolation_mark_mask = 0;
810 
811 	/* randomize initial seqno to avoid collision */
812 	get_random_bytes(&random_seqno, sizeof(random_seqno));
813 	atomic_set(&bat_priv->frag_seqno, random_seqno);
814 
815 	bat_priv->primary_if = NULL;
816 
817 	batadv_nc_init_bat_priv(bat_priv);
818 
819 	if (!bat_priv->algo_ops) {
820 		ret = batadv_algo_select(bat_priv, batadv_routing_algo);
821 		if (ret < 0)
822 			goto free_bat_counters;
823 	}
824 
825 	ret = batadv_mesh_init(dev);
826 	if (ret < 0)
827 		goto free_bat_counters;
828 
829 	return 0;
830 
831 free_bat_counters:
832 	free_percpu(bat_priv->bat_counters);
833 	bat_priv->bat_counters = NULL;
834 
835 	return ret;
836 }
837 
838 /**
839  * batadv_softif_slave_add() - Add a slave interface to a batadv_soft_interface
840  * @dev: batadv_soft_interface used as master interface
841  * @slave_dev: net_device which should become the slave interface
842  * @extack: extended ACK report struct
843  *
844  * Return: 0 if successful or error otherwise.
845  */
846 static int batadv_softif_slave_add(struct net_device *dev,
847 				   struct net_device *slave_dev,
848 				   struct netlink_ext_ack *extack)
849 {
850 	struct batadv_hard_iface *hard_iface;
851 	struct net *net = dev_net(dev);
852 	int ret = -EINVAL;
853 
854 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
855 	if (!hard_iface || hard_iface->soft_iface)
856 		goto out;
857 
858 	ret = batadv_hardif_enable_interface(hard_iface, net, dev->name);
859 
860 out:
861 	if (hard_iface)
862 		batadv_hardif_put(hard_iface);
863 	return ret;
864 }
865 
866 /**
867  * batadv_softif_slave_del() - Delete a slave iface from a batadv_soft_interface
868  * @dev: batadv_soft_interface used as master interface
869  * @slave_dev: net_device which should be removed from the master interface
870  *
871  * Return: 0 if successful or error otherwise.
872  */
873 static int batadv_softif_slave_del(struct net_device *dev,
874 				   struct net_device *slave_dev)
875 {
876 	struct batadv_hard_iface *hard_iface;
877 	int ret = -EINVAL;
878 
879 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
880 
881 	if (!hard_iface || hard_iface->soft_iface != dev)
882 		goto out;
883 
884 	batadv_hardif_disable_interface(hard_iface);
885 	ret = 0;
886 
887 out:
888 	if (hard_iface)
889 		batadv_hardif_put(hard_iface);
890 	return ret;
891 }
892 
893 static const struct net_device_ops batadv_netdev_ops = {
894 	.ndo_init = batadv_softif_init_late,
895 	.ndo_open = batadv_interface_open,
896 	.ndo_stop = batadv_interface_release,
897 	.ndo_get_stats = batadv_interface_stats,
898 	.ndo_vlan_rx_add_vid = batadv_interface_add_vid,
899 	.ndo_vlan_rx_kill_vid = batadv_interface_kill_vid,
900 	.ndo_set_mac_address = batadv_interface_set_mac_addr,
901 	.ndo_change_mtu = batadv_interface_change_mtu,
902 	.ndo_set_rx_mode = batadv_interface_set_rx_mode,
903 	.ndo_start_xmit = batadv_interface_tx,
904 	.ndo_validate_addr = eth_validate_addr,
905 	.ndo_add_slave = batadv_softif_slave_add,
906 	.ndo_del_slave = batadv_softif_slave_del,
907 };
908 
909 static void batadv_get_drvinfo(struct net_device *dev,
910 			       struct ethtool_drvinfo *info)
911 {
912 	strscpy(info->driver, "B.A.T.M.A.N. advanced", sizeof(info->driver));
913 	strscpy(info->version, BATADV_SOURCE_VERSION, sizeof(info->version));
914 	strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
915 	strscpy(info->bus_info, "batman", sizeof(info->bus_info));
916 }
917 
918 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
919  * Declare each description string in struct.name[] to get fixed sized buffer
920  * and compile time checking for strings longer than ETH_GSTRING_LEN.
921  */
922 static const struct {
923 	const char name[ETH_GSTRING_LEN];
924 } batadv_counters_strings[] = {
925 	{ "tx" },
926 	{ "tx_bytes" },
927 	{ "tx_dropped" },
928 	{ "rx" },
929 	{ "rx_bytes" },
930 	{ "forward" },
931 	{ "forward_bytes" },
932 	{ "mgmt_tx" },
933 	{ "mgmt_tx_bytes" },
934 	{ "mgmt_rx" },
935 	{ "mgmt_rx_bytes" },
936 	{ "frag_tx" },
937 	{ "frag_tx_bytes" },
938 	{ "frag_rx" },
939 	{ "frag_rx_bytes" },
940 	{ "frag_fwd" },
941 	{ "frag_fwd_bytes" },
942 	{ "tt_request_tx" },
943 	{ "tt_request_rx" },
944 	{ "tt_response_tx" },
945 	{ "tt_response_rx" },
946 	{ "tt_roam_adv_tx" },
947 	{ "tt_roam_adv_rx" },
948 #ifdef CONFIG_BATMAN_ADV_DAT
949 	{ "dat_get_tx" },
950 	{ "dat_get_rx" },
951 	{ "dat_put_tx" },
952 	{ "dat_put_rx" },
953 	{ "dat_cached_reply_tx" },
954 #endif
955 #ifdef CONFIG_BATMAN_ADV_NC
956 	{ "nc_code" },
957 	{ "nc_code_bytes" },
958 	{ "nc_recode" },
959 	{ "nc_recode_bytes" },
960 	{ "nc_buffer" },
961 	{ "nc_decode" },
962 	{ "nc_decode_bytes" },
963 	{ "nc_decode_failed" },
964 	{ "nc_sniffed" },
965 #endif
966 };
967 
968 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data)
969 {
970 	if (stringset == ETH_SS_STATS)
971 		memcpy(data, batadv_counters_strings,
972 		       sizeof(batadv_counters_strings));
973 }
974 
975 static void batadv_get_ethtool_stats(struct net_device *dev,
976 				     struct ethtool_stats *stats, u64 *data)
977 {
978 	struct batadv_priv *bat_priv = netdev_priv(dev);
979 	int i;
980 
981 	for (i = 0; i < BATADV_CNT_NUM; i++)
982 		data[i] = batadv_sum_counter(bat_priv, i);
983 }
984 
985 static int batadv_get_sset_count(struct net_device *dev, int stringset)
986 {
987 	if (stringset == ETH_SS_STATS)
988 		return BATADV_CNT_NUM;
989 
990 	return -EOPNOTSUPP;
991 }
992 
993 static const struct ethtool_ops batadv_ethtool_ops = {
994 	.get_drvinfo = batadv_get_drvinfo,
995 	.get_link = ethtool_op_get_link,
996 	.get_strings = batadv_get_strings,
997 	.get_ethtool_stats = batadv_get_ethtool_stats,
998 	.get_sset_count = batadv_get_sset_count,
999 };
1000 
1001 /**
1002  * batadv_softif_free() - Deconstructor of batadv_soft_interface
1003  * @dev: Device to cleanup and remove
1004  */
1005 static void batadv_softif_free(struct net_device *dev)
1006 {
1007 	batadv_mesh_free(dev);
1008 
1009 	/* some scheduled RCU callbacks need the bat_priv struct to accomplish
1010 	 * their tasks. Wait for them all to be finished before freeing the
1011 	 * netdev and its private data (bat_priv)
1012 	 */
1013 	rcu_barrier();
1014 }
1015 
1016 /**
1017  * batadv_softif_init_early() - early stage initialization of soft interface
1018  * @dev: registered network device to modify
1019  */
1020 static void batadv_softif_init_early(struct net_device *dev)
1021 {
1022 	ether_setup(dev);
1023 
1024 	dev->netdev_ops = &batadv_netdev_ops;
1025 	dev->needs_free_netdev = true;
1026 	dev->priv_destructor = batadv_softif_free;
1027 	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_NETNS_LOCAL;
1028 	dev->features |= NETIF_F_LLTX;
1029 	dev->priv_flags |= IFF_NO_QUEUE;
1030 
1031 	/* can't call min_mtu, because the needed variables
1032 	 * have not been initialized yet
1033 	 */
1034 	dev->mtu = ETH_DATA_LEN;
1035 
1036 	/* generate random address */
1037 	eth_hw_addr_random(dev);
1038 
1039 	dev->ethtool_ops = &batadv_ethtool_ops;
1040 }
1041 
1042 /**
1043  * batadv_softif_validate() - validate configuration of new batadv link
1044  * @tb: IFLA_INFO_DATA netlink attributes
1045  * @data: enum batadv_ifla_attrs attributes
1046  * @extack: extended ACK report struct
1047  *
1048  * Return: 0 if successful or error otherwise.
1049  */
1050 static int batadv_softif_validate(struct nlattr *tb[], struct nlattr *data[],
1051 				  struct netlink_ext_ack *extack)
1052 {
1053 	struct batadv_algo_ops *algo_ops;
1054 
1055 	if (!data)
1056 		return 0;
1057 
1058 	if (data[IFLA_BATADV_ALGO_NAME]) {
1059 		algo_ops = batadv_algo_get(nla_data(data[IFLA_BATADV_ALGO_NAME]));
1060 		if (!algo_ops)
1061 			return -EINVAL;
1062 	}
1063 
1064 	return 0;
1065 }
1066 
1067 /**
1068  * batadv_softif_newlink() - pre-initialize and register new batadv link
1069  * @src_net: the applicable net namespace
1070  * @dev: network device to register
1071  * @tb: IFLA_INFO_DATA netlink attributes
1072  * @data: enum batadv_ifla_attrs attributes
1073  * @extack: extended ACK report struct
1074  *
1075  * Return: 0 if successful or error otherwise.
1076  */
1077 static int batadv_softif_newlink(struct net *src_net, struct net_device *dev,
1078 				 struct nlattr *tb[], struct nlattr *data[],
1079 				 struct netlink_ext_ack *extack)
1080 {
1081 	struct batadv_priv *bat_priv = netdev_priv(dev);
1082 	const char *algo_name;
1083 	int err;
1084 
1085 	if (data && data[IFLA_BATADV_ALGO_NAME]) {
1086 		algo_name = nla_data(data[IFLA_BATADV_ALGO_NAME]);
1087 		err = batadv_algo_select(bat_priv, algo_name);
1088 		if (err)
1089 			return -EINVAL;
1090 	}
1091 
1092 	return register_netdevice(dev);
1093 }
1094 
1095 /**
1096  * batadv_softif_create() - Create and register soft interface
1097  * @net: the applicable net namespace
1098  * @name: name of the new soft interface
1099  *
1100  * Return: newly allocated soft_interface, NULL on errors
1101  */
1102 struct net_device *batadv_softif_create(struct net *net, const char *name)
1103 {
1104 	struct net_device *soft_iface;
1105 	int ret;
1106 
1107 	soft_iface = alloc_netdev(sizeof(struct batadv_priv), name,
1108 				  NET_NAME_UNKNOWN, batadv_softif_init_early);
1109 	if (!soft_iface)
1110 		return NULL;
1111 
1112 	dev_net_set(soft_iface, net);
1113 
1114 	soft_iface->rtnl_link_ops = &batadv_link_ops;
1115 
1116 	ret = register_netdevice(soft_iface);
1117 	if (ret < 0) {
1118 		pr_err("Unable to register the batman interface '%s': %i\n",
1119 		       name, ret);
1120 		free_netdev(soft_iface);
1121 		return NULL;
1122 	}
1123 
1124 	return soft_iface;
1125 }
1126 
1127 /**
1128  * batadv_softif_destroy_netlink() - deletion of batadv_soft_interface via
1129  *  netlink
1130  * @soft_iface: the to-be-removed batman-adv interface
1131  * @head: list pointer
1132  */
1133 static void batadv_softif_destroy_netlink(struct net_device *soft_iface,
1134 					  struct list_head *head)
1135 {
1136 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
1137 	struct batadv_hard_iface *hard_iface;
1138 	struct batadv_softif_vlan *vlan;
1139 
1140 	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {
1141 		if (hard_iface->soft_iface == soft_iface)
1142 			batadv_hardif_disable_interface(hard_iface);
1143 	}
1144 
1145 	/* destroy the "untagged" VLAN */
1146 	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1147 	if (vlan) {
1148 		batadv_softif_destroy_vlan(bat_priv, vlan);
1149 		batadv_softif_vlan_put(vlan);
1150 	}
1151 
1152 	unregister_netdevice_queue(soft_iface, head);
1153 }
1154 
1155 /**
1156  * batadv_softif_is_valid() - Check whether device is a batadv soft interface
1157  * @net_dev: device which should be checked
1158  *
1159  * Return: true when net_dev is a batman-adv interface, false otherwise
1160  */
1161 bool batadv_softif_is_valid(const struct net_device *net_dev)
1162 {
1163 	if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
1164 		return true;
1165 
1166 	return false;
1167 }
1168 
1169 static const struct nla_policy batadv_ifla_policy[IFLA_BATADV_MAX + 1] = {
1170 	[IFLA_BATADV_ALGO_NAME]	= { .type = NLA_NUL_STRING },
1171 };
1172 
1173 struct rtnl_link_ops batadv_link_ops __read_mostly = {
1174 	.kind		= "batadv",
1175 	.priv_size	= sizeof(struct batadv_priv),
1176 	.setup		= batadv_softif_init_early,
1177 	.maxtype	= IFLA_BATADV_MAX,
1178 	.policy		= batadv_ifla_policy,
1179 	.validate	= batadv_softif_validate,
1180 	.newlink	= batadv_softif_newlink,
1181 	.dellink	= batadv_softif_destroy_netlink,
1182 };
1183