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1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2007-2020  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  */
batadv_skb_head_push(struct sk_buff * skb,unsigned int len)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 
batadv_interface_open(struct net_device * dev)83 static int batadv_interface_open(struct net_device *dev)
84 {
85 	netif_start_queue(dev);
86 	return 0;
87 }
88 
batadv_interface_release(struct net_device * dev)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  */
batadv_sum_counter(struct batadv_priv * bat_priv,size_t idx)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 
batadv_interface_stats(struct net_device * dev)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 
batadv_interface_set_mac_addr(struct net_device * dev,void * p)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 
batadv_interface_change_mtu(struct net_device * dev,int new_mtu)157 static int batadv_interface_change_mtu(struct net_device *dev, int new_mtu)
158 {
159 	struct batadv_priv *bat_priv = netdev_priv(dev);
160 
161 	/* check ranges */
162 	if (new_mtu < 68 || new_mtu > batadv_hardif_min_mtu(dev))
163 		return -EINVAL;
164 
165 	dev->mtu = new_mtu;
166 	bat_priv->mtu_set_by_user = new_mtu;
167 
168 	return 0;
169 }
170 
171 /**
172  * batadv_interface_set_rx_mode() - set the rx mode of a device
173  * @dev: registered network device to modify
174  *
175  * We do not actually need to set any rx filters for the virtual batman
176  * soft interface. However a dummy handler enables a user to set static
177  * multicast listeners for instance.
178  */
batadv_interface_set_rx_mode(struct net_device * dev)179 static void batadv_interface_set_rx_mode(struct net_device *dev)
180 {
181 }
182 
batadv_interface_tx(struct sk_buff * skb,struct net_device * soft_iface)183 static netdev_tx_t batadv_interface_tx(struct sk_buff *skb,
184 				       struct net_device *soft_iface)
185 {
186 	struct ethhdr *ethhdr;
187 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
188 	struct batadv_hard_iface *primary_if = NULL;
189 	struct batadv_bcast_packet *bcast_packet;
190 	static const u8 stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00,
191 					      0x00, 0x00};
192 	static const u8 ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00,
193 					       0x00, 0x00};
194 	enum batadv_dhcp_recipient dhcp_rcp = BATADV_DHCP_NO;
195 	u8 *dst_hint = NULL, chaddr[ETH_ALEN];
196 	struct vlan_ethhdr *vhdr;
197 	unsigned int header_len = 0;
198 	int data_len = skb->len, ret;
199 	unsigned long brd_delay = 1;
200 	bool do_bcast = false, client_added;
201 	unsigned short vid;
202 	u32 seqno;
203 	int gw_mode;
204 	enum batadv_forw_mode forw_mode = BATADV_FORW_SINGLE;
205 	struct batadv_orig_node *mcast_single_orig = NULL;
206 	int mcast_is_routable = 0;
207 	int network_offset = ETH_HLEN;
208 	__be16 proto;
209 
210 	if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE)
211 		goto dropped;
212 
213 	/* reset control block to avoid left overs from previous users */
214 	memset(skb->cb, 0, sizeof(struct batadv_skb_cb));
215 
216 	netif_trans_update(soft_iface);
217 	vid = batadv_get_vid(skb, 0);
218 
219 	skb_reset_mac_header(skb);
220 	ethhdr = eth_hdr(skb);
221 
222 	proto = ethhdr->h_proto;
223 
224 	switch (ntohs(proto)) {
225 	case ETH_P_8021Q:
226 		if (!pskb_may_pull(skb, sizeof(*vhdr)))
227 			goto dropped;
228 		vhdr = vlan_eth_hdr(skb);
229 		proto = vhdr->h_vlan_encapsulated_proto;
230 
231 		/* drop batman-in-batman packets to prevent loops */
232 		if (proto != htons(ETH_P_BATMAN)) {
233 			network_offset += VLAN_HLEN;
234 			break;
235 		}
236 
237 		fallthrough;
238 	case ETH_P_BATMAN:
239 		goto dropped;
240 	}
241 
242 	skb_set_network_header(skb, network_offset);
243 
244 	if (batadv_bla_tx(bat_priv, skb, vid))
245 		goto dropped;
246 
247 	/* skb->data might have been reallocated by batadv_bla_tx() */
248 	ethhdr = eth_hdr(skb);
249 
250 	/* Register the client MAC in the transtable */
251 	if (!is_multicast_ether_addr(ethhdr->h_source) &&
252 	    !batadv_bla_is_loopdetect_mac(ethhdr->h_source)) {
253 		client_added = batadv_tt_local_add(soft_iface, ethhdr->h_source,
254 						   vid, skb->skb_iif,
255 						   skb->mark);
256 		if (!client_added)
257 			goto dropped;
258 	}
259 
260 	/* Snoop address candidates from DHCPACKs for early DAT filling */
261 	batadv_dat_snoop_outgoing_dhcp_ack(bat_priv, skb, proto, vid);
262 
263 	/* don't accept stp packets. STP does not help in meshes.
264 	 * better use the bridge loop avoidance ...
265 	 *
266 	 * The same goes for ECTP sent at least by some Cisco Switches,
267 	 * it might confuse the mesh when used with bridge loop avoidance.
268 	 */
269 	if (batadv_compare_eth(ethhdr->h_dest, stp_addr))
270 		goto dropped;
271 
272 	if (batadv_compare_eth(ethhdr->h_dest, ectp_addr))
273 		goto dropped;
274 
275 	gw_mode = atomic_read(&bat_priv->gw.mode);
276 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
277 		/* if gw mode is off, broadcast every packet */
278 		if (gw_mode == BATADV_GW_MODE_OFF) {
279 			do_bcast = true;
280 			goto send;
281 		}
282 
283 		dhcp_rcp = batadv_gw_dhcp_recipient_get(skb, &header_len,
284 							chaddr);
285 		/* skb->data may have been modified by
286 		 * batadv_gw_dhcp_recipient_get()
287 		 */
288 		ethhdr = eth_hdr(skb);
289 		/* if gw_mode is on, broadcast any non-DHCP message.
290 		 * All the DHCP packets are going to be sent as unicast
291 		 */
292 		if (dhcp_rcp == BATADV_DHCP_NO) {
293 			do_bcast = true;
294 			goto send;
295 		}
296 
297 		if (dhcp_rcp == BATADV_DHCP_TO_CLIENT)
298 			dst_hint = chaddr;
299 		else if ((gw_mode == BATADV_GW_MODE_SERVER) &&
300 			 (dhcp_rcp == BATADV_DHCP_TO_SERVER))
301 			/* gateways should not forward any DHCP message if
302 			 * directed to a DHCP server
303 			 */
304 			goto dropped;
305 
306 send:
307 		if (do_bcast && !is_broadcast_ether_addr(ethhdr->h_dest)) {
308 			forw_mode = batadv_mcast_forw_mode(bat_priv, skb,
309 							   &mcast_single_orig,
310 							   &mcast_is_routable);
311 			if (forw_mode == BATADV_FORW_NONE)
312 				goto dropped;
313 
314 			if (forw_mode == BATADV_FORW_SINGLE ||
315 			    forw_mode == BATADV_FORW_SOME)
316 				do_bcast = false;
317 		}
318 	}
319 
320 	batadv_skb_set_priority(skb, 0);
321 
322 	/* ethernet packet should be broadcasted */
323 	if (do_bcast) {
324 		primary_if = batadv_primary_if_get_selected(bat_priv);
325 		if (!primary_if)
326 			goto dropped;
327 
328 		/* in case of ARP request, we do not immediately broadcasti the
329 		 * packet, instead we first wait for DAT to try to retrieve the
330 		 * correct ARP entry
331 		 */
332 		if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb))
333 			brd_delay = msecs_to_jiffies(ARP_REQ_DELAY);
334 
335 		if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0)
336 			goto dropped;
337 
338 		bcast_packet = (struct batadv_bcast_packet *)skb->data;
339 		bcast_packet->version = BATADV_COMPAT_VERSION;
340 		bcast_packet->ttl = BATADV_TTL;
341 
342 		/* batman packet type: broadcast */
343 		bcast_packet->packet_type = BATADV_BCAST;
344 		bcast_packet->reserved = 0;
345 
346 		/* hw address of first interface is the orig mac because only
347 		 * this mac is known throughout the mesh
348 		 */
349 		ether_addr_copy(bcast_packet->orig,
350 				primary_if->net_dev->dev_addr);
351 
352 		/* set broadcast sequence number */
353 		seqno = atomic_inc_return(&bat_priv->bcast_seqno);
354 		bcast_packet->seqno = htonl(seqno);
355 
356 		batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay, true);
357 
358 		/* a copy is stored in the bcast list, therefore removing
359 		 * the original skb.
360 		 */
361 		consume_skb(skb);
362 
363 	/* unicast packet */
364 	} else {
365 		/* DHCP packets going to a server will use the GW feature */
366 		if (dhcp_rcp == BATADV_DHCP_TO_SERVER) {
367 			ret = batadv_gw_out_of_range(bat_priv, skb);
368 			if (ret)
369 				goto dropped;
370 			ret = batadv_send_skb_via_gw(bat_priv, skb, vid);
371 		} else if (mcast_single_orig) {
372 			ret = batadv_mcast_forw_send_orig(bat_priv, skb, vid,
373 							  mcast_single_orig);
374 		} else if (forw_mode == BATADV_FORW_SOME) {
375 			ret = batadv_mcast_forw_send(bat_priv, skb, vid,
376 						     mcast_is_routable);
377 		} else {
378 			if (batadv_dat_snoop_outgoing_arp_request(bat_priv,
379 								  skb))
380 				goto dropped;
381 
382 			batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb);
383 
384 			ret = batadv_send_skb_via_tt(bat_priv, skb, dst_hint,
385 						     vid);
386 		}
387 		if (ret != NET_XMIT_SUCCESS)
388 			goto dropped_freed;
389 	}
390 
391 	batadv_inc_counter(bat_priv, BATADV_CNT_TX);
392 	batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len);
393 	goto end;
394 
395 dropped:
396 	kfree_skb(skb);
397 dropped_freed:
398 	batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED);
399 end:
400 	if (mcast_single_orig)
401 		batadv_orig_node_put(mcast_single_orig);
402 	if (primary_if)
403 		batadv_hardif_put(primary_if);
404 	return NETDEV_TX_OK;
405 }
406 
407 /**
408  * batadv_interface_rx() - receive ethernet frame on local batman-adv interface
409  * @soft_iface: local interface which will receive the ethernet frame
410  * @skb: ethernet frame for @soft_iface
411  * @hdr_size: size of already parsed batman-adv header
412  * @orig_node: originator from which the batman-adv packet was sent
413  *
414  * Sends an ethernet frame to the receive path of the local @soft_iface.
415  * skb->data has still point to the batman-adv header with the size @hdr_size.
416  * The caller has to have parsed this header already and made sure that at least
417  * @hdr_size bytes are still available for pull in @skb.
418  *
419  * The packet may still get dropped. This can happen when the encapsulated
420  * ethernet frame is invalid or contains again an batman-adv packet. Also
421  * unicast packets will be dropped directly when it was sent between two
422  * isolated clients.
423  */
batadv_interface_rx(struct net_device * soft_iface,struct sk_buff * skb,int hdr_size,struct batadv_orig_node * orig_node)424 void batadv_interface_rx(struct net_device *soft_iface,
425 			 struct sk_buff *skb, int hdr_size,
426 			 struct batadv_orig_node *orig_node)
427 {
428 	struct batadv_bcast_packet *batadv_bcast_packet;
429 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
430 	struct vlan_ethhdr *vhdr;
431 	struct ethhdr *ethhdr;
432 	unsigned short vid;
433 	int packet_type;
434 
435 	batadv_bcast_packet = (struct batadv_bcast_packet *)skb->data;
436 	packet_type = batadv_bcast_packet->packet_type;
437 
438 	skb_pull_rcsum(skb, hdr_size);
439 	skb_reset_mac_header(skb);
440 
441 	/* clean the netfilter state now that the batman-adv header has been
442 	 * removed
443 	 */
444 	nf_reset_ct(skb);
445 
446 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
447 		goto dropped;
448 
449 	vid = batadv_get_vid(skb, 0);
450 	ethhdr = eth_hdr(skb);
451 
452 	switch (ntohs(ethhdr->h_proto)) {
453 	case ETH_P_8021Q:
454 		if (!pskb_may_pull(skb, VLAN_ETH_HLEN))
455 			goto dropped;
456 
457 		vhdr = skb_vlan_eth_hdr(skb);
458 
459 		/* drop batman-in-batman packets to prevent loops */
460 		if (vhdr->h_vlan_encapsulated_proto != htons(ETH_P_BATMAN))
461 			break;
462 
463 		fallthrough;
464 	case ETH_P_BATMAN:
465 		goto dropped;
466 	}
467 
468 	/* skb->dev & skb->pkt_type are set here */
469 	skb->protocol = eth_type_trans(skb, soft_iface);
470 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
471 
472 	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
473 	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
474 			   skb->len + ETH_HLEN);
475 
476 	/* Let the bridge loop avoidance check the packet. If will
477 	 * not handle it, we can safely push it up.
478 	 */
479 	if (batadv_bla_rx(bat_priv, skb, vid, packet_type))
480 		goto out;
481 
482 	if (orig_node)
483 		batadv_tt_add_temporary_global_entry(bat_priv, orig_node,
484 						     ethhdr->h_source, vid);
485 
486 	if (is_multicast_ether_addr(ethhdr->h_dest)) {
487 		/* set the mark on broadcast packets if AP isolation is ON and
488 		 * the packet is coming from an "isolated" client
489 		 */
490 		if (batadv_vlan_ap_isola_get(bat_priv, vid) &&
491 		    batadv_tt_global_is_isolated(bat_priv, ethhdr->h_source,
492 						 vid)) {
493 			/* save bits in skb->mark not covered by the mask and
494 			 * apply the mark on the rest
495 			 */
496 			skb->mark &= ~bat_priv->isolation_mark_mask;
497 			skb->mark |= bat_priv->isolation_mark;
498 		}
499 	} else if (batadv_is_ap_isolated(bat_priv, ethhdr->h_source,
500 					 ethhdr->h_dest, vid)) {
501 		goto dropped;
502 	}
503 
504 	netif_rx(skb);
505 	goto out;
506 
507 dropped:
508 	kfree_skb(skb);
509 out:
510 	return;
511 }
512 
513 /**
514  * batadv_softif_vlan_release() - release vlan from lists and queue for free
515  *  after rcu grace period
516  * @ref: kref pointer of the vlan object
517  */
batadv_softif_vlan_release(struct kref * ref)518 void batadv_softif_vlan_release(struct kref *ref)
519 {
520 	struct batadv_softif_vlan *vlan;
521 
522 	vlan = container_of(ref, struct batadv_softif_vlan, refcount);
523 
524 	spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock);
525 	hlist_del_rcu(&vlan->list);
526 	spin_unlock_bh(&vlan->bat_priv->softif_vlan_list_lock);
527 
528 	kfree_rcu(vlan, rcu);
529 }
530 
531 /**
532  * batadv_softif_vlan_get() - get the vlan object for a specific vid
533  * @bat_priv: the bat priv with all the soft interface information
534  * @vid: the identifier of the vlan object to retrieve
535  *
536  * Return: the private data of the vlan matching the vid passed as argument or
537  * NULL otherwise. The refcounter of the returned object is incremented by 1.
538  */
batadv_softif_vlan_get(struct batadv_priv * bat_priv,unsigned short vid)539 struct batadv_softif_vlan *batadv_softif_vlan_get(struct batadv_priv *bat_priv,
540 						  unsigned short vid)
541 {
542 	struct batadv_softif_vlan *vlan_tmp, *vlan = NULL;
543 
544 	rcu_read_lock();
545 	hlist_for_each_entry_rcu(vlan_tmp, &bat_priv->softif_vlan_list, list) {
546 		if (vlan_tmp->vid != vid)
547 			continue;
548 
549 		if (!kref_get_unless_zero(&vlan_tmp->refcount))
550 			continue;
551 
552 		vlan = vlan_tmp;
553 		break;
554 	}
555 	rcu_read_unlock();
556 
557 	return vlan;
558 }
559 
560 /**
561  * batadv_softif_create_vlan() - allocate the needed resources for a new vlan
562  * @bat_priv: the bat priv with all the soft interface information
563  * @vid: the VLAN identifier
564  *
565  * Return: 0 on success, a negative error otherwise.
566  */
batadv_softif_create_vlan(struct batadv_priv * bat_priv,unsigned short vid)567 int batadv_softif_create_vlan(struct batadv_priv *bat_priv, unsigned short vid)
568 {
569 	struct batadv_softif_vlan *vlan;
570 	int err;
571 
572 	spin_lock_bh(&bat_priv->softif_vlan_list_lock);
573 
574 	vlan = batadv_softif_vlan_get(bat_priv, vid);
575 	if (vlan) {
576 		batadv_softif_vlan_put(vlan);
577 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
578 		return -EEXIST;
579 	}
580 
581 	vlan = kzalloc(sizeof(*vlan), GFP_ATOMIC);
582 	if (!vlan) {
583 		spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
584 		return -ENOMEM;
585 	}
586 
587 	vlan->bat_priv = bat_priv;
588 	vlan->vid = vid;
589 	kref_init(&vlan->refcount);
590 
591 	atomic_set(&vlan->ap_isolation, 0);
592 
593 	kref_get(&vlan->refcount);
594 	hlist_add_head_rcu(&vlan->list, &bat_priv->softif_vlan_list);
595 	spin_unlock_bh(&bat_priv->softif_vlan_list_lock);
596 
597 	/* batadv_sysfs_add_vlan cannot be in the spinlock section due to the
598 	 * sleeping behavior of the sysfs functions and the fs_reclaim lock
599 	 */
600 	err = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
601 	if (err) {
602 		/* ref for the function */
603 		batadv_softif_vlan_put(vlan);
604 
605 		/* ref for the list */
606 		batadv_softif_vlan_put(vlan);
607 		return err;
608 	}
609 
610 	/* add a new TT local entry. This one will be marked with the NOPURGE
611 	 * flag
612 	 */
613 	batadv_tt_local_add(bat_priv->soft_iface,
614 			    bat_priv->soft_iface->dev_addr, vid,
615 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
616 
617 	/* don't return reference to new softif_vlan */
618 	batadv_softif_vlan_put(vlan);
619 
620 	return 0;
621 }
622 
623 /**
624  * batadv_softif_destroy_vlan() - remove and destroy a softif_vlan object
625  * @bat_priv: the bat priv with all the soft interface information
626  * @vlan: the object to remove
627  */
batadv_softif_destroy_vlan(struct batadv_priv * bat_priv,struct batadv_softif_vlan * vlan)628 static void batadv_softif_destroy_vlan(struct batadv_priv *bat_priv,
629 				       struct batadv_softif_vlan *vlan)
630 {
631 	/* explicitly remove the associated TT local entry because it is marked
632 	 * with the NOPURGE flag
633 	 */
634 	batadv_tt_local_remove(bat_priv, bat_priv->soft_iface->dev_addr,
635 			       vlan->vid, "vlan interface destroyed", false);
636 
637 	batadv_sysfs_del_vlan(bat_priv, vlan);
638 	batadv_softif_vlan_put(vlan);
639 }
640 
641 /**
642  * batadv_interface_add_vid() - ndo_add_vid API implementation
643  * @dev: the netdev of the mesh interface
644  * @proto: protocol of the vlan id
645  * @vid: identifier of the new vlan
646  *
647  * Set up all the internal structures for handling the new vlan on top of the
648  * mesh interface
649  *
650  * Return: 0 on success or a negative error code in case of failure.
651  */
batadv_interface_add_vid(struct net_device * dev,__be16 proto,unsigned short vid)652 static int batadv_interface_add_vid(struct net_device *dev, __be16 proto,
653 				    unsigned short vid)
654 {
655 	struct batadv_priv *bat_priv = netdev_priv(dev);
656 	struct batadv_softif_vlan *vlan;
657 	int ret;
658 
659 	/* only 802.1Q vlans are supported.
660 	 * batman-adv does not know how to handle other types
661 	 */
662 	if (proto != htons(ETH_P_8021Q))
663 		return -EINVAL;
664 
665 	vid |= BATADV_VLAN_HAS_TAG;
666 
667 	/* if a new vlan is getting created and it already exists, it means that
668 	 * it was not deleted yet. batadv_softif_vlan_get() increases the
669 	 * refcount in order to revive the object.
670 	 *
671 	 * if it does not exist then create it.
672 	 */
673 	vlan = batadv_softif_vlan_get(bat_priv, vid);
674 	if (!vlan)
675 		return batadv_softif_create_vlan(bat_priv, vid);
676 
677 	/* recreate the sysfs object if it was already destroyed (and it should
678 	 * be since we received a kill_vid() for this vlan
679 	 */
680 	if (!vlan->kobj) {
681 		ret = batadv_sysfs_add_vlan(bat_priv->soft_iface, vlan);
682 		if (ret) {
683 			batadv_softif_vlan_put(vlan);
684 			return ret;
685 		}
686 	}
687 
688 	/* add a new TT local entry. This one will be marked with the NOPURGE
689 	 * flag. This must be added again, even if the vlan object already
690 	 * exists, because the entry was deleted by kill_vid()
691 	 */
692 	batadv_tt_local_add(bat_priv->soft_iface,
693 			    bat_priv->soft_iface->dev_addr, vid,
694 			    BATADV_NULL_IFINDEX, BATADV_NO_MARK);
695 
696 	return 0;
697 }
698 
699 /**
700  * batadv_interface_kill_vid() - ndo_kill_vid API implementation
701  * @dev: the netdev of the mesh interface
702  * @proto: protocol of the vlan id
703  * @vid: identifier of the deleted vlan
704  *
705  * Destroy all the internal structures used to handle the vlan identified by vid
706  * on top of the mesh interface
707  *
708  * Return: 0 on success, -EINVAL if the specified prototype is not ETH_P_8021Q
709  * or -ENOENT if the specified vlan id wasn't registered.
710  */
batadv_interface_kill_vid(struct net_device * dev,__be16 proto,unsigned short vid)711 static int batadv_interface_kill_vid(struct net_device *dev, __be16 proto,
712 				     unsigned short vid)
713 {
714 	struct batadv_priv *bat_priv = netdev_priv(dev);
715 	struct batadv_softif_vlan *vlan;
716 
717 	/* only 802.1Q vlans are supported. batman-adv does not know how to
718 	 * handle other types
719 	 */
720 	if (proto != htons(ETH_P_8021Q))
721 		return -EINVAL;
722 
723 	vlan = batadv_softif_vlan_get(bat_priv, vid | BATADV_VLAN_HAS_TAG);
724 	if (!vlan)
725 		return -ENOENT;
726 
727 	batadv_softif_destroy_vlan(bat_priv, vlan);
728 
729 	/* finally free the vlan object */
730 	batadv_softif_vlan_put(vlan);
731 
732 	return 0;
733 }
734 
735 /* batman-adv network devices have devices nesting below it and are a special
736  * "super class" of normal network devices; split their locks off into a
737  * separate class since they always nest.
738  */
739 static struct lock_class_key batadv_netdev_xmit_lock_key;
740 static struct lock_class_key batadv_netdev_addr_lock_key;
741 
742 /**
743  * batadv_set_lockdep_class_one() - Set lockdep class for a single tx queue
744  * @dev: device which owns the tx queue
745  * @txq: tx queue to modify
746  * @_unused: always NULL
747  */
batadv_set_lockdep_class_one(struct net_device * dev,struct netdev_queue * txq,void * _unused)748 static void batadv_set_lockdep_class_one(struct net_device *dev,
749 					 struct netdev_queue *txq,
750 					 void *_unused)
751 {
752 	lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key);
753 }
754 
755 /**
756  * batadv_set_lockdep_class() - Set txq and addr_list lockdep class
757  * @dev: network device to modify
758  */
batadv_set_lockdep_class(struct net_device * dev)759 static void batadv_set_lockdep_class(struct net_device *dev)
760 {
761 	lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key);
762 	netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL);
763 }
764 
765 /**
766  * batadv_softif_init_late() - late stage initialization of soft interface
767  * @dev: registered network device to modify
768  *
769  * Return: error code on failures
770  */
batadv_softif_init_late(struct net_device * dev)771 static int batadv_softif_init_late(struct net_device *dev)
772 {
773 	struct batadv_priv *bat_priv;
774 	u32 random_seqno;
775 	int ret;
776 	size_t cnt_len = sizeof(u64) * BATADV_CNT_NUM;
777 
778 	batadv_set_lockdep_class(dev);
779 
780 	bat_priv = netdev_priv(dev);
781 	bat_priv->soft_iface = dev;
782 
783 	/* batadv_interface_stats() needs to be available as soon as
784 	 * register_netdevice() has been called
785 	 */
786 	bat_priv->bat_counters = __alloc_percpu(cnt_len, __alignof__(u64));
787 	if (!bat_priv->bat_counters)
788 		return -ENOMEM;
789 
790 	atomic_set(&bat_priv->aggregated_ogms, 1);
791 	atomic_set(&bat_priv->bonding, 0);
792 #ifdef CONFIG_BATMAN_ADV_BLA
793 	atomic_set(&bat_priv->bridge_loop_avoidance, 1);
794 #endif
795 #ifdef CONFIG_BATMAN_ADV_DAT
796 	atomic_set(&bat_priv->distributed_arp_table, 1);
797 #endif
798 #ifdef CONFIG_BATMAN_ADV_MCAST
799 	atomic_set(&bat_priv->multicast_mode, 1);
800 	atomic_set(&bat_priv->multicast_fanout, 16);
801 	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);
802 	atomic_set(&bat_priv->mcast.num_want_all_ipv4, 0);
803 	atomic_set(&bat_priv->mcast.num_want_all_ipv6, 0);
804 #endif
805 	atomic_set(&bat_priv->gw.mode, BATADV_GW_MODE_OFF);
806 	atomic_set(&bat_priv->gw.bandwidth_down, 100);
807 	atomic_set(&bat_priv->gw.bandwidth_up, 20);
808 	atomic_set(&bat_priv->orig_interval, 1000);
809 	atomic_set(&bat_priv->hop_penalty, 30);
810 #ifdef CONFIG_BATMAN_ADV_DEBUG
811 	atomic_set(&bat_priv->log_level, 0);
812 #endif
813 	atomic_set(&bat_priv->fragmentation, 1);
814 	atomic_set(&bat_priv->packet_size_max, ETH_DATA_LEN);
815 	atomic_set(&bat_priv->bcast_queue_left, BATADV_BCAST_QUEUE_LEN);
816 	atomic_set(&bat_priv->batman_queue_left, BATADV_BATMAN_QUEUE_LEN);
817 
818 	atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE);
819 	atomic_set(&bat_priv->bcast_seqno, 1);
820 	atomic_set(&bat_priv->tt.vn, 0);
821 	atomic_set(&bat_priv->tt.local_changes, 0);
822 	atomic_set(&bat_priv->tt.ogm_append_cnt, 0);
823 #ifdef CONFIG_BATMAN_ADV_BLA
824 	atomic_set(&bat_priv->bla.num_requests, 0);
825 #endif
826 	atomic_set(&bat_priv->tp_num, 0);
827 
828 	bat_priv->tt.last_changeset = NULL;
829 	bat_priv->tt.last_changeset_len = 0;
830 	bat_priv->isolation_mark = 0;
831 	bat_priv->isolation_mark_mask = 0;
832 
833 	/* randomize initial seqno to avoid collision */
834 	get_random_bytes(&random_seqno, sizeof(random_seqno));
835 	atomic_set(&bat_priv->frag_seqno, random_seqno);
836 
837 	bat_priv->primary_if = NULL;
838 
839 	batadv_nc_init_bat_priv(bat_priv);
840 
841 	ret = batadv_algo_select(bat_priv, batadv_routing_algo);
842 	if (ret < 0)
843 		goto free_bat_counters;
844 
845 	ret = batadv_debugfs_add_meshif(dev);
846 	if (ret < 0)
847 		goto free_bat_counters;
848 
849 	ret = batadv_mesh_init(dev);
850 	if (ret < 0)
851 		goto unreg_debugfs;
852 
853 	return 0;
854 
855 unreg_debugfs:
856 	batadv_debugfs_del_meshif(dev);
857 free_bat_counters:
858 	free_percpu(bat_priv->bat_counters);
859 	bat_priv->bat_counters = NULL;
860 
861 	return ret;
862 }
863 
864 /**
865  * batadv_softif_slave_add() - Add a slave interface to a batadv_soft_interface
866  * @dev: batadv_soft_interface used as master interface
867  * @slave_dev: net_device which should become the slave interface
868  * @extack: extended ACK report struct
869  *
870  * Return: 0 if successful or error otherwise.
871  */
batadv_softif_slave_add(struct net_device * dev,struct net_device * slave_dev,struct netlink_ext_ack * extack)872 static int batadv_softif_slave_add(struct net_device *dev,
873 				   struct net_device *slave_dev,
874 				   struct netlink_ext_ack *extack)
875 {
876 	struct batadv_hard_iface *hard_iface;
877 	struct net *net = dev_net(dev);
878 	int ret = -EINVAL;
879 
880 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
881 	if (!hard_iface || hard_iface->soft_iface)
882 		goto out;
883 
884 	ret = batadv_hardif_enable_interface(hard_iface, net, dev->name);
885 
886 out:
887 	if (hard_iface)
888 		batadv_hardif_put(hard_iface);
889 	return ret;
890 }
891 
892 /**
893  * batadv_softif_slave_del() - Delete a slave iface from a batadv_soft_interface
894  * @dev: batadv_soft_interface used as master interface
895  * @slave_dev: net_device which should be removed from the master interface
896  *
897  * Return: 0 if successful or error otherwise.
898  */
batadv_softif_slave_del(struct net_device * dev,struct net_device * slave_dev)899 static int batadv_softif_slave_del(struct net_device *dev,
900 				   struct net_device *slave_dev)
901 {
902 	struct batadv_hard_iface *hard_iface;
903 	int ret = -EINVAL;
904 
905 	hard_iface = batadv_hardif_get_by_netdev(slave_dev);
906 
907 	if (!hard_iface || hard_iface->soft_iface != dev)
908 		goto out;
909 
910 	batadv_hardif_disable_interface(hard_iface, BATADV_IF_CLEANUP_KEEP);
911 	ret = 0;
912 
913 out:
914 	if (hard_iface)
915 		batadv_hardif_put(hard_iface);
916 	return ret;
917 }
918 
919 static const struct net_device_ops batadv_netdev_ops = {
920 	.ndo_init = batadv_softif_init_late,
921 	.ndo_open = batadv_interface_open,
922 	.ndo_stop = batadv_interface_release,
923 	.ndo_get_stats = batadv_interface_stats,
924 	.ndo_vlan_rx_add_vid = batadv_interface_add_vid,
925 	.ndo_vlan_rx_kill_vid = batadv_interface_kill_vid,
926 	.ndo_set_mac_address = batadv_interface_set_mac_addr,
927 	.ndo_change_mtu = batadv_interface_change_mtu,
928 	.ndo_set_rx_mode = batadv_interface_set_rx_mode,
929 	.ndo_start_xmit = batadv_interface_tx,
930 	.ndo_validate_addr = eth_validate_addr,
931 	.ndo_add_slave = batadv_softif_slave_add,
932 	.ndo_del_slave = batadv_softif_slave_del,
933 };
934 
batadv_get_drvinfo(struct net_device * dev,struct ethtool_drvinfo * info)935 static void batadv_get_drvinfo(struct net_device *dev,
936 			       struct ethtool_drvinfo *info)
937 {
938 	strscpy(info->driver, "B.A.T.M.A.N. advanced", sizeof(info->driver));
939 	strscpy(info->version, BATADV_SOURCE_VERSION, sizeof(info->version));
940 	strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
941 	strscpy(info->bus_info, "batman", sizeof(info->bus_info));
942 }
943 
944 /* Inspired by drivers/net/ethernet/dlink/sundance.c:1702
945  * Declare each description string in struct.name[] to get fixed sized buffer
946  * and compile time checking for strings longer than ETH_GSTRING_LEN.
947  */
948 static const struct {
949 	const char name[ETH_GSTRING_LEN];
950 } batadv_counters_strings[] = {
951 	{ "tx" },
952 	{ "tx_bytes" },
953 	{ "tx_dropped" },
954 	{ "rx" },
955 	{ "rx_bytes" },
956 	{ "forward" },
957 	{ "forward_bytes" },
958 	{ "mgmt_tx" },
959 	{ "mgmt_tx_bytes" },
960 	{ "mgmt_rx" },
961 	{ "mgmt_rx_bytes" },
962 	{ "frag_tx" },
963 	{ "frag_tx_bytes" },
964 	{ "frag_rx" },
965 	{ "frag_rx_bytes" },
966 	{ "frag_fwd" },
967 	{ "frag_fwd_bytes" },
968 	{ "tt_request_tx" },
969 	{ "tt_request_rx" },
970 	{ "tt_response_tx" },
971 	{ "tt_response_rx" },
972 	{ "tt_roam_adv_tx" },
973 	{ "tt_roam_adv_rx" },
974 #ifdef CONFIG_BATMAN_ADV_DAT
975 	{ "dat_get_tx" },
976 	{ "dat_get_rx" },
977 	{ "dat_put_tx" },
978 	{ "dat_put_rx" },
979 	{ "dat_cached_reply_tx" },
980 #endif
981 #ifdef CONFIG_BATMAN_ADV_NC
982 	{ "nc_code" },
983 	{ "nc_code_bytes" },
984 	{ "nc_recode" },
985 	{ "nc_recode_bytes" },
986 	{ "nc_buffer" },
987 	{ "nc_decode" },
988 	{ "nc_decode_bytes" },
989 	{ "nc_decode_failed" },
990 	{ "nc_sniffed" },
991 #endif
992 };
993 
batadv_get_strings(struct net_device * dev,u32 stringset,u8 * data)994 static void batadv_get_strings(struct net_device *dev, u32 stringset, u8 *data)
995 {
996 	if (stringset == ETH_SS_STATS)
997 		memcpy(data, batadv_counters_strings,
998 		       sizeof(batadv_counters_strings));
999 }
1000 
batadv_get_ethtool_stats(struct net_device * dev,struct ethtool_stats * stats,u64 * data)1001 static void batadv_get_ethtool_stats(struct net_device *dev,
1002 				     struct ethtool_stats *stats, u64 *data)
1003 {
1004 	struct batadv_priv *bat_priv = netdev_priv(dev);
1005 	int i;
1006 
1007 	for (i = 0; i < BATADV_CNT_NUM; i++)
1008 		data[i] = batadv_sum_counter(bat_priv, i);
1009 }
1010 
batadv_get_sset_count(struct net_device * dev,int stringset)1011 static int batadv_get_sset_count(struct net_device *dev, int stringset)
1012 {
1013 	if (stringset == ETH_SS_STATS)
1014 		return BATADV_CNT_NUM;
1015 
1016 	return -EOPNOTSUPP;
1017 }
1018 
1019 static const struct ethtool_ops batadv_ethtool_ops = {
1020 	.get_drvinfo = batadv_get_drvinfo,
1021 	.get_link = ethtool_op_get_link,
1022 	.get_strings = batadv_get_strings,
1023 	.get_ethtool_stats = batadv_get_ethtool_stats,
1024 	.get_sset_count = batadv_get_sset_count,
1025 };
1026 
1027 /**
1028  * batadv_softif_free() - Deconstructor of batadv_soft_interface
1029  * @dev: Device to cleanup and remove
1030  */
batadv_softif_free(struct net_device * dev)1031 static void batadv_softif_free(struct net_device *dev)
1032 {
1033 	batadv_debugfs_del_meshif(dev);
1034 	batadv_mesh_free(dev);
1035 
1036 	/* some scheduled RCU callbacks need the bat_priv struct to accomplish
1037 	 * their tasks. Wait for them all to be finished before freeing the
1038 	 * netdev and its private data (bat_priv)
1039 	 */
1040 	rcu_barrier();
1041 }
1042 
1043 /**
1044  * batadv_softif_init_early() - early stage initialization of soft interface
1045  * @dev: registered network device to modify
1046  */
batadv_softif_init_early(struct net_device * dev)1047 static void batadv_softif_init_early(struct net_device *dev)
1048 {
1049 	ether_setup(dev);
1050 
1051 	dev->netdev_ops = &batadv_netdev_ops;
1052 	dev->needs_free_netdev = true;
1053 	dev->priv_destructor = batadv_softif_free;
1054 	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_NETNS_LOCAL;
1055 	dev->features |= NETIF_F_LLTX;
1056 	dev->priv_flags |= IFF_NO_QUEUE;
1057 
1058 	/* can't call min_mtu, because the needed variables
1059 	 * have not been initialized yet
1060 	 */
1061 	dev->mtu = ETH_DATA_LEN;
1062 
1063 	/* generate random address */
1064 	eth_hw_addr_random(dev);
1065 
1066 	dev->ethtool_ops = &batadv_ethtool_ops;
1067 }
1068 
1069 /**
1070  * batadv_softif_create() - Create and register soft interface
1071  * @net: the applicable net namespace
1072  * @name: name of the new soft interface
1073  *
1074  * Return: newly allocated soft_interface, NULL on errors
1075  */
batadv_softif_create(struct net * net,const char * name)1076 struct net_device *batadv_softif_create(struct net *net, const char *name)
1077 {
1078 	struct net_device *soft_iface;
1079 	int ret;
1080 
1081 	soft_iface = alloc_netdev(sizeof(struct batadv_priv), name,
1082 				  NET_NAME_UNKNOWN, batadv_softif_init_early);
1083 	if (!soft_iface)
1084 		return NULL;
1085 
1086 	dev_net_set(soft_iface, net);
1087 
1088 	soft_iface->rtnl_link_ops = &batadv_link_ops;
1089 
1090 	ret = register_netdevice(soft_iface);
1091 	if (ret < 0) {
1092 		pr_err("Unable to register the batman interface '%s': %i\n",
1093 		       name, ret);
1094 		free_netdev(soft_iface);
1095 		return NULL;
1096 	}
1097 
1098 	return soft_iface;
1099 }
1100 
1101 /**
1102  * batadv_softif_destroy_sysfs() - deletion of batadv_soft_interface via sysfs
1103  * @soft_iface: the to-be-removed batman-adv interface
1104  */
batadv_softif_destroy_sysfs(struct net_device * soft_iface)1105 void batadv_softif_destroy_sysfs(struct net_device *soft_iface)
1106 {
1107 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
1108 	struct batadv_softif_vlan *vlan;
1109 
1110 	ASSERT_RTNL();
1111 
1112 	/* destroy the "untagged" VLAN */
1113 	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1114 	if (vlan) {
1115 		batadv_softif_destroy_vlan(bat_priv, vlan);
1116 		batadv_softif_vlan_put(vlan);
1117 	}
1118 
1119 	batadv_sysfs_del_meshif(soft_iface);
1120 	unregister_netdevice(soft_iface);
1121 }
1122 
1123 /**
1124  * batadv_softif_destroy_netlink() - deletion of batadv_soft_interface via
1125  *  netlink
1126  * @soft_iface: the to-be-removed batman-adv interface
1127  * @head: list pointer
1128  */
batadv_softif_destroy_netlink(struct net_device * soft_iface,struct list_head * head)1129 static void batadv_softif_destroy_netlink(struct net_device *soft_iface,
1130 					  struct list_head *head)
1131 {
1132 	struct batadv_priv *bat_priv = netdev_priv(soft_iface);
1133 	struct batadv_hard_iface *hard_iface;
1134 	struct batadv_softif_vlan *vlan;
1135 
1136 	list_for_each_entry(hard_iface, &batadv_hardif_list, list) {
1137 		if (hard_iface->soft_iface == soft_iface)
1138 			batadv_hardif_disable_interface(hard_iface,
1139 							BATADV_IF_CLEANUP_KEEP);
1140 	}
1141 
1142 	/* destroy the "untagged" VLAN */
1143 	vlan = batadv_softif_vlan_get(bat_priv, BATADV_NO_FLAGS);
1144 	if (vlan) {
1145 		batadv_softif_destroy_vlan(bat_priv, vlan);
1146 		batadv_softif_vlan_put(vlan);
1147 	}
1148 
1149 	batadv_sysfs_del_meshif(soft_iface);
1150 	unregister_netdevice_queue(soft_iface, head);
1151 }
1152 
1153 /**
1154  * batadv_softif_is_valid() - Check whether device is a batadv soft interface
1155  * @net_dev: device which should be checked
1156  *
1157  * Return: true when net_dev is a batman-adv interface, false otherwise
1158  */
batadv_softif_is_valid(const struct net_device * net_dev)1159 bool batadv_softif_is_valid(const struct net_device *net_dev)
1160 {
1161 	if (net_dev->netdev_ops->ndo_start_xmit == batadv_interface_tx)
1162 		return true;
1163 
1164 	return false;
1165 }
1166 
1167 struct rtnl_link_ops batadv_link_ops __read_mostly = {
1168 	.kind		= "batadv",
1169 	.priv_size	= sizeof(struct batadv_priv),
1170 	.setup		= batadv_softif_init_early,
1171 	.dellink	= batadv_softif_destroy_netlink,
1172 };
1173