xref: /linux/drivers/net/macvlan.c (revision 834f0c353ae430c1a6ce023c9b77bbd3ff9241a7)
1 /*
2  * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation; either version 2 of
7  * the License, or (at your option) any later version.
8  *
9  * The code this is based on carried the following copyright notice:
10  * ---
11  * (C) Copyright 2001-2006
12  * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
13  * Re-worked by Ben Greear <greearb@candelatech.com>
14  * ---
15  */
16 #include <linux/kernel.h>
17 #include <linux/types.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/errno.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/rculist.h>
24 #include <linux/notifier.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/ethtool.h>
28 #include <linux/if_arp.h>
29 #include <linux/if_link.h>
30 #include <linux/if_macvlan.h>
31 #include <net/rtnetlink.h>
32 #include <net/xfrm.h>
33 
34 #define MACVLAN_HASH_SIZE	(1 << BITS_PER_BYTE)
35 
36 struct macvlan_port {
37 	struct net_device	*dev;
38 	struct hlist_head	vlan_hash[MACVLAN_HASH_SIZE];
39 	struct list_head	vlans;
40 	struct rcu_head		rcu;
41 	bool 			passthru;
42 	int			count;
43 };
44 
45 static void macvlan_port_destroy(struct net_device *dev);
46 
47 #define macvlan_port_get_rcu(dev) \
48 	((struct macvlan_port *) rcu_dereference(dev->rx_handler_data))
49 #define macvlan_port_get(dev) ((struct macvlan_port *) dev->rx_handler_data)
50 #define macvlan_port_exists(dev) (dev->priv_flags & IFF_MACVLAN_PORT)
51 
52 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
53 					       const unsigned char *addr)
54 {
55 	struct macvlan_dev *vlan;
56 	struct hlist_node *n;
57 
58 	hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
59 		if (!compare_ether_addr_64bits(vlan->dev->dev_addr, addr))
60 			return vlan;
61 	}
62 	return NULL;
63 }
64 
65 static void macvlan_hash_add(struct macvlan_dev *vlan)
66 {
67 	struct macvlan_port *port = vlan->port;
68 	const unsigned char *addr = vlan->dev->dev_addr;
69 
70 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
71 }
72 
73 static void macvlan_hash_del(struct macvlan_dev *vlan)
74 {
75 	hlist_del_rcu(&vlan->hlist);
76 	synchronize_rcu();
77 }
78 
79 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
80 					const unsigned char *addr)
81 {
82 	macvlan_hash_del(vlan);
83 	/* Now that we are unhashed it is safe to change the device
84 	 * address without confusing packet delivery.
85 	 */
86 	memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
87 	macvlan_hash_add(vlan);
88 }
89 
90 static int macvlan_addr_busy(const struct macvlan_port *port,
91 				const unsigned char *addr)
92 {
93 	/* Test to see if the specified multicast address is
94 	 * currently in use by the underlying device or
95 	 * another macvlan.
96 	 */
97 	if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
98 		return 1;
99 
100 	if (macvlan_hash_lookup(port, addr))
101 		return 1;
102 
103 	return 0;
104 }
105 
106 
107 static int macvlan_broadcast_one(struct sk_buff *skb,
108 				 const struct macvlan_dev *vlan,
109 				 const struct ethhdr *eth, bool local)
110 {
111 	struct net_device *dev = vlan->dev;
112 	if (!skb)
113 		return NET_RX_DROP;
114 
115 	if (local)
116 		return vlan->forward(dev, skb);
117 
118 	skb->dev = dev;
119 	if (!compare_ether_addr_64bits(eth->h_dest,
120 				       dev->broadcast))
121 		skb->pkt_type = PACKET_BROADCAST;
122 	else
123 		skb->pkt_type = PACKET_MULTICAST;
124 
125 	return vlan->receive(skb);
126 }
127 
128 static void macvlan_broadcast(struct sk_buff *skb,
129 			      const struct macvlan_port *port,
130 			      struct net_device *src,
131 			      enum macvlan_mode mode)
132 {
133 	const struct ethhdr *eth = eth_hdr(skb);
134 	const struct macvlan_dev *vlan;
135 	struct hlist_node *n;
136 	struct sk_buff *nskb;
137 	unsigned int i;
138 	int err;
139 
140 	if (skb->protocol == htons(ETH_P_PAUSE))
141 		return;
142 
143 	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
144 		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
145 			if (vlan->dev == src || !(vlan->mode & mode))
146 				continue;
147 
148 			nskb = skb_clone(skb, GFP_ATOMIC);
149 			err = macvlan_broadcast_one(nskb, vlan, eth,
150 					 mode == MACVLAN_MODE_BRIDGE);
151 			macvlan_count_rx(vlan, skb->len + ETH_HLEN,
152 					 err == NET_RX_SUCCESS, 1);
153 		}
154 	}
155 }
156 
157 /* called under rcu_read_lock() from netif_receive_skb */
158 static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
159 {
160 	struct macvlan_port *port;
161 	struct sk_buff *skb = *pskb;
162 	const struct ethhdr *eth = eth_hdr(skb);
163 	const struct macvlan_dev *vlan;
164 	const struct macvlan_dev *src;
165 	struct net_device *dev;
166 	unsigned int len = 0;
167 	int ret = NET_RX_DROP;
168 
169 	port = macvlan_port_get_rcu(skb->dev);
170 	if (is_multicast_ether_addr(eth->h_dest)) {
171 		src = macvlan_hash_lookup(port, eth->h_source);
172 		if (!src)
173 			/* frame comes from an external address */
174 			macvlan_broadcast(skb, port, NULL,
175 					  MACVLAN_MODE_PRIVATE |
176 					  MACVLAN_MODE_VEPA    |
177 					  MACVLAN_MODE_PASSTHRU|
178 					  MACVLAN_MODE_BRIDGE);
179 		else if (src->mode == MACVLAN_MODE_VEPA)
180 			/* flood to everyone except source */
181 			macvlan_broadcast(skb, port, src->dev,
182 					  MACVLAN_MODE_VEPA |
183 					  MACVLAN_MODE_BRIDGE);
184 		else if (src->mode == MACVLAN_MODE_BRIDGE)
185 			/*
186 			 * flood only to VEPA ports, bridge ports
187 			 * already saw the frame on the way out.
188 			 */
189 			macvlan_broadcast(skb, port, src->dev,
190 					  MACVLAN_MODE_VEPA);
191 		return RX_HANDLER_PASS;
192 	}
193 
194 	if (port->passthru)
195 		vlan = list_first_entry(&port->vlans, struct macvlan_dev, list);
196 	else
197 		vlan = macvlan_hash_lookup(port, eth->h_dest);
198 	if (vlan == NULL)
199 		return RX_HANDLER_PASS;
200 
201 	dev = vlan->dev;
202 	if (unlikely(!(dev->flags & IFF_UP))) {
203 		kfree_skb(skb);
204 		return RX_HANDLER_CONSUMED;
205 	}
206 	len = skb->len + ETH_HLEN;
207 	skb = skb_share_check(skb, GFP_ATOMIC);
208 	if (!skb)
209 		goto out;
210 
211 	skb->dev = dev;
212 	skb->pkt_type = PACKET_HOST;
213 
214 	ret = vlan->receive(skb);
215 
216 out:
217 	macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);
218 	return RX_HANDLER_CONSUMED;
219 }
220 
221 static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
222 {
223 	const struct macvlan_dev *vlan = netdev_priv(dev);
224 	const struct macvlan_port *port = vlan->port;
225 	const struct macvlan_dev *dest;
226 	__u8 ip_summed = skb->ip_summed;
227 
228 	if (vlan->mode == MACVLAN_MODE_BRIDGE) {
229 		const struct ethhdr *eth = (void *)skb->data;
230 		skb->ip_summed = CHECKSUM_UNNECESSARY;
231 
232 		/* send to other bridge ports directly */
233 		if (is_multicast_ether_addr(eth->h_dest)) {
234 			macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
235 			goto xmit_world;
236 		}
237 
238 		dest = macvlan_hash_lookup(port, eth->h_dest);
239 		if (dest && dest->mode == MACVLAN_MODE_BRIDGE) {
240 			unsigned int length = skb->len + ETH_HLEN;
241 			int ret = dest->forward(dest->dev, skb);
242 			macvlan_count_rx(dest, length,
243 					 ret == NET_RX_SUCCESS, 0);
244 
245 			return NET_XMIT_SUCCESS;
246 		}
247 	}
248 
249 xmit_world:
250 	skb->ip_summed = ip_summed;
251 	skb_set_dev(skb, vlan->lowerdev);
252 	return dev_queue_xmit(skb);
253 }
254 
255 netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
256 			       struct net_device *dev)
257 {
258 	unsigned int len = skb->len;
259 	int ret;
260 	const struct macvlan_dev *vlan = netdev_priv(dev);
261 
262 	ret = macvlan_queue_xmit(skb, dev);
263 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
264 		struct macvlan_pcpu_stats *pcpu_stats;
265 
266 		pcpu_stats = this_cpu_ptr(vlan->pcpu_stats);
267 		u64_stats_update_begin(&pcpu_stats->syncp);
268 		pcpu_stats->tx_packets++;
269 		pcpu_stats->tx_bytes += len;
270 		u64_stats_update_end(&pcpu_stats->syncp);
271 	} else {
272 		this_cpu_inc(vlan->pcpu_stats->tx_dropped);
273 	}
274 	return ret;
275 }
276 EXPORT_SYMBOL_GPL(macvlan_start_xmit);
277 
278 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
279 			       unsigned short type, const void *daddr,
280 			       const void *saddr, unsigned len)
281 {
282 	const struct macvlan_dev *vlan = netdev_priv(dev);
283 	struct net_device *lowerdev = vlan->lowerdev;
284 
285 	return dev_hard_header(skb, lowerdev, type, daddr,
286 			       saddr ? : dev->dev_addr, len);
287 }
288 
289 static const struct header_ops macvlan_hard_header_ops = {
290 	.create  	= macvlan_hard_header,
291 	.rebuild	= eth_rebuild_header,
292 	.parse		= eth_header_parse,
293 	.cache		= eth_header_cache,
294 	.cache_update	= eth_header_cache_update,
295 };
296 
297 static int macvlan_open(struct net_device *dev)
298 {
299 	struct macvlan_dev *vlan = netdev_priv(dev);
300 	struct net_device *lowerdev = vlan->lowerdev;
301 	int err;
302 
303 	if (vlan->port->passthru) {
304 		dev_set_promiscuity(lowerdev, 1);
305 		goto hash_add;
306 	}
307 
308 	err = -EBUSY;
309 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
310 		goto out;
311 
312 	err = dev_uc_add(lowerdev, dev->dev_addr);
313 	if (err < 0)
314 		goto out;
315 	if (dev->flags & IFF_ALLMULTI) {
316 		err = dev_set_allmulti(lowerdev, 1);
317 		if (err < 0)
318 			goto del_unicast;
319 	}
320 
321 hash_add:
322 	macvlan_hash_add(vlan);
323 	return 0;
324 
325 del_unicast:
326 	dev_uc_del(lowerdev, dev->dev_addr);
327 out:
328 	return err;
329 }
330 
331 static int macvlan_stop(struct net_device *dev)
332 {
333 	struct macvlan_dev *vlan = netdev_priv(dev);
334 	struct net_device *lowerdev = vlan->lowerdev;
335 
336 	if (vlan->port->passthru) {
337 		dev_set_promiscuity(lowerdev, -1);
338 		goto hash_del;
339 	}
340 
341 	dev_mc_unsync(lowerdev, dev);
342 	if (dev->flags & IFF_ALLMULTI)
343 		dev_set_allmulti(lowerdev, -1);
344 
345 	dev_uc_del(lowerdev, dev->dev_addr);
346 
347 hash_del:
348 	macvlan_hash_del(vlan);
349 	return 0;
350 }
351 
352 static int macvlan_set_mac_address(struct net_device *dev, void *p)
353 {
354 	struct macvlan_dev *vlan = netdev_priv(dev);
355 	struct net_device *lowerdev = vlan->lowerdev;
356 	struct sockaddr *addr = p;
357 	int err;
358 
359 	if (!is_valid_ether_addr(addr->sa_data))
360 		return -EADDRNOTAVAIL;
361 
362 	if (!(dev->flags & IFF_UP)) {
363 		/* Just copy in the new address */
364 		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
365 	} else {
366 		/* Rehash and update the device filters */
367 		if (macvlan_addr_busy(vlan->port, addr->sa_data))
368 			return -EBUSY;
369 
370 		err = dev_uc_add(lowerdev, addr->sa_data);
371 		if (err)
372 			return err;
373 
374 		dev_uc_del(lowerdev, dev->dev_addr);
375 
376 		macvlan_hash_change_addr(vlan, addr->sa_data);
377 	}
378 	return 0;
379 }
380 
381 static void macvlan_change_rx_flags(struct net_device *dev, int change)
382 {
383 	struct macvlan_dev *vlan = netdev_priv(dev);
384 	struct net_device *lowerdev = vlan->lowerdev;
385 
386 	if (change & IFF_ALLMULTI)
387 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
388 }
389 
390 static void macvlan_set_multicast_list(struct net_device *dev)
391 {
392 	struct macvlan_dev *vlan = netdev_priv(dev);
393 
394 	dev_mc_sync(vlan->lowerdev, dev);
395 }
396 
397 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
398 {
399 	struct macvlan_dev *vlan = netdev_priv(dev);
400 
401 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
402 		return -EINVAL;
403 	dev->mtu = new_mtu;
404 	return 0;
405 }
406 
407 /*
408  * macvlan network devices have devices nesting below it and are a special
409  * "super class" of normal network devices; split their locks off into a
410  * separate class since they always nest.
411  */
412 static struct lock_class_key macvlan_netdev_xmit_lock_key;
413 static struct lock_class_key macvlan_netdev_addr_lock_key;
414 
415 #define MACVLAN_FEATURES \
416 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
417 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
418 	 NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO)
419 
420 #define MACVLAN_STATE_MASK \
421 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
422 
423 static void macvlan_set_lockdep_class_one(struct net_device *dev,
424 					  struct netdev_queue *txq,
425 					  void *_unused)
426 {
427 	lockdep_set_class(&txq->_xmit_lock,
428 			  &macvlan_netdev_xmit_lock_key);
429 }
430 
431 static void macvlan_set_lockdep_class(struct net_device *dev)
432 {
433 	lockdep_set_class(&dev->addr_list_lock,
434 			  &macvlan_netdev_addr_lock_key);
435 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
436 }
437 
438 static int macvlan_init(struct net_device *dev)
439 {
440 	struct macvlan_dev *vlan = netdev_priv(dev);
441 	const struct net_device *lowerdev = vlan->lowerdev;
442 
443 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
444 				  (lowerdev->state & MACVLAN_STATE_MASK);
445 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
446 	dev->features		|= NETIF_F_LLTX;
447 	dev->gso_max_size	= lowerdev->gso_max_size;
448 	dev->iflink		= lowerdev->ifindex;
449 	dev->hard_header_len	= lowerdev->hard_header_len;
450 
451 	macvlan_set_lockdep_class(dev);
452 
453 	vlan->pcpu_stats = alloc_percpu(struct macvlan_pcpu_stats);
454 	if (!vlan->pcpu_stats)
455 		return -ENOMEM;
456 
457 	return 0;
458 }
459 
460 static void macvlan_uninit(struct net_device *dev)
461 {
462 	struct macvlan_dev *vlan = netdev_priv(dev);
463 	struct macvlan_port *port = vlan->port;
464 
465 	free_percpu(vlan->pcpu_stats);
466 
467 	port->count -= 1;
468 	if (!port->count)
469 		macvlan_port_destroy(port->dev);
470 }
471 
472 static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
473 							 struct rtnl_link_stats64 *stats)
474 {
475 	struct macvlan_dev *vlan = netdev_priv(dev);
476 
477 	if (vlan->pcpu_stats) {
478 		struct macvlan_pcpu_stats *p;
479 		u64 rx_packets, rx_bytes, rx_multicast, tx_packets, tx_bytes;
480 		u32 rx_errors = 0, tx_dropped = 0;
481 		unsigned int start;
482 		int i;
483 
484 		for_each_possible_cpu(i) {
485 			p = per_cpu_ptr(vlan->pcpu_stats, i);
486 			do {
487 				start = u64_stats_fetch_begin_bh(&p->syncp);
488 				rx_packets	= p->rx_packets;
489 				rx_bytes	= p->rx_bytes;
490 				rx_multicast	= p->rx_multicast;
491 				tx_packets	= p->tx_packets;
492 				tx_bytes	= p->tx_bytes;
493 			} while (u64_stats_fetch_retry_bh(&p->syncp, start));
494 
495 			stats->rx_packets	+= rx_packets;
496 			stats->rx_bytes		+= rx_bytes;
497 			stats->multicast	+= rx_multicast;
498 			stats->tx_packets	+= tx_packets;
499 			stats->tx_bytes		+= tx_bytes;
500 			/* rx_errors & tx_dropped are u32, updated
501 			 * without syncp protection.
502 			 */
503 			rx_errors	+= p->rx_errors;
504 			tx_dropped	+= p->tx_dropped;
505 		}
506 		stats->rx_errors	= rx_errors;
507 		stats->rx_dropped	= rx_errors;
508 		stats->tx_dropped	= tx_dropped;
509 	}
510 	return stats;
511 }
512 
513 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
514 					struct ethtool_drvinfo *drvinfo)
515 {
516 	snprintf(drvinfo->driver, 32, "macvlan");
517 	snprintf(drvinfo->version, 32, "0.1");
518 }
519 
520 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
521 {
522 	const struct macvlan_dev *vlan = netdev_priv(dev);
523 	return dev_ethtool_get_rx_csum(vlan->lowerdev);
524 }
525 
526 static int macvlan_ethtool_get_settings(struct net_device *dev,
527 					struct ethtool_cmd *cmd)
528 {
529 	const struct macvlan_dev *vlan = netdev_priv(dev);
530 	return dev_ethtool_get_settings(vlan->lowerdev, cmd);
531 }
532 
533 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
534 {
535 	const struct macvlan_dev *vlan = netdev_priv(dev);
536 	return dev_ethtool_get_flags(vlan->lowerdev);
537 }
538 
539 static const struct ethtool_ops macvlan_ethtool_ops = {
540 	.get_link		= ethtool_op_get_link,
541 	.get_settings		= macvlan_ethtool_get_settings,
542 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
543 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
544 	.get_flags		= macvlan_ethtool_get_flags,
545 };
546 
547 static const struct net_device_ops macvlan_netdev_ops = {
548 	.ndo_init		= macvlan_init,
549 	.ndo_uninit		= macvlan_uninit,
550 	.ndo_open		= macvlan_open,
551 	.ndo_stop		= macvlan_stop,
552 	.ndo_start_xmit		= macvlan_start_xmit,
553 	.ndo_change_mtu		= macvlan_change_mtu,
554 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
555 	.ndo_set_mac_address	= macvlan_set_mac_address,
556 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
557 	.ndo_get_stats64	= macvlan_dev_get_stats64,
558 	.ndo_validate_addr	= eth_validate_addr,
559 };
560 
561 void macvlan_common_setup(struct net_device *dev)
562 {
563 	ether_setup(dev);
564 
565 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
566 	dev->netdev_ops		= &macvlan_netdev_ops;
567 	dev->destructor		= free_netdev;
568 	dev->header_ops		= &macvlan_hard_header_ops,
569 	dev->ethtool_ops	= &macvlan_ethtool_ops;
570 }
571 EXPORT_SYMBOL_GPL(macvlan_common_setup);
572 
573 static void macvlan_setup(struct net_device *dev)
574 {
575 	macvlan_common_setup(dev);
576 	dev->tx_queue_len	= 0;
577 }
578 
579 static int macvlan_port_create(struct net_device *dev)
580 {
581 	struct macvlan_port *port;
582 	unsigned int i;
583 	int err;
584 
585 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
586 		return -EINVAL;
587 
588 	port = kzalloc(sizeof(*port), GFP_KERNEL);
589 	if (port == NULL)
590 		return -ENOMEM;
591 
592 	port->passthru = false;
593 	port->dev = dev;
594 	INIT_LIST_HEAD(&port->vlans);
595 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
596 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
597 
598 	err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
599 	if (err)
600 		kfree(port);
601 
602 	dev->priv_flags |= IFF_MACVLAN_PORT;
603 	return err;
604 }
605 
606 static void macvlan_port_rcu_free(struct rcu_head *head)
607 {
608 	struct macvlan_port *port;
609 
610 	port = container_of(head, struct macvlan_port, rcu);
611 	kfree(port);
612 }
613 
614 static void macvlan_port_destroy(struct net_device *dev)
615 {
616 	struct macvlan_port *port = macvlan_port_get(dev);
617 
618 	dev->priv_flags &= ~IFF_MACVLAN_PORT;
619 	netdev_rx_handler_unregister(dev);
620 	call_rcu(&port->rcu, macvlan_port_rcu_free);
621 }
622 
623 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
624 {
625 	if (tb[IFLA_ADDRESS]) {
626 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
627 			return -EINVAL;
628 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
629 			return -EADDRNOTAVAIL;
630 	}
631 
632 	if (data && data[IFLA_MACVLAN_MODE]) {
633 		switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
634 		case MACVLAN_MODE_PRIVATE:
635 		case MACVLAN_MODE_VEPA:
636 		case MACVLAN_MODE_BRIDGE:
637 		case MACVLAN_MODE_PASSTHRU:
638 			break;
639 		default:
640 			return -EINVAL;
641 		}
642 	}
643 	return 0;
644 }
645 
646 int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
647 			   struct nlattr *tb[], struct nlattr *data[],
648 			   int (*receive)(struct sk_buff *skb),
649 			   int (*forward)(struct net_device *dev,
650 					  struct sk_buff *skb))
651 {
652 	struct macvlan_dev *vlan = netdev_priv(dev);
653 	struct macvlan_port *port;
654 	struct net_device *lowerdev;
655 	int err;
656 
657 	if (!tb[IFLA_LINK])
658 		return -EINVAL;
659 
660 	lowerdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
661 	if (lowerdev == NULL)
662 		return -ENODEV;
663 
664 	/* When creating macvlans on top of other macvlans - use
665 	 * the real device as the lowerdev.
666 	 */
667 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
668 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
669 		lowerdev = lowervlan->lowerdev;
670 	}
671 
672 	if (!tb[IFLA_MTU])
673 		dev->mtu = lowerdev->mtu;
674 	else if (dev->mtu > lowerdev->mtu)
675 		return -EINVAL;
676 
677 	if (!tb[IFLA_ADDRESS])
678 		random_ether_addr(dev->dev_addr);
679 
680 	if (!macvlan_port_exists(lowerdev)) {
681 		err = macvlan_port_create(lowerdev);
682 		if (err < 0)
683 			return err;
684 	}
685 	port = macvlan_port_get(lowerdev);
686 
687 	/* Only 1 macvlan device can be created in passthru mode */
688 	if (port->passthru)
689 		return -EINVAL;
690 
691 	vlan->lowerdev = lowerdev;
692 	vlan->dev      = dev;
693 	vlan->port     = port;
694 	vlan->receive  = receive;
695 	vlan->forward  = forward;
696 
697 	vlan->mode     = MACVLAN_MODE_VEPA;
698 	if (data && data[IFLA_MACVLAN_MODE])
699 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
700 
701 	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
702 		if (port->count)
703 			return -EINVAL;
704 		port->passthru = true;
705 		memcpy(dev->dev_addr, lowerdev->dev_addr, ETH_ALEN);
706 	}
707 
708 	port->count += 1;
709 	err = register_netdevice(dev);
710 	if (err < 0)
711 		goto destroy_port;
712 
713 	list_add_tail(&vlan->list, &port->vlans);
714 	netif_stacked_transfer_operstate(lowerdev, dev);
715 
716 	return 0;
717 
718 destroy_port:
719 	port->count -= 1;
720 	if (!port->count)
721 		macvlan_port_destroy(lowerdev);
722 
723 	return err;
724 }
725 EXPORT_SYMBOL_GPL(macvlan_common_newlink);
726 
727 static int macvlan_newlink(struct net *src_net, struct net_device *dev,
728 			   struct nlattr *tb[], struct nlattr *data[])
729 {
730 	return macvlan_common_newlink(src_net, dev, tb, data,
731 				      netif_rx,
732 				      dev_forward_skb);
733 }
734 
735 void macvlan_dellink(struct net_device *dev, struct list_head *head)
736 {
737 	struct macvlan_dev *vlan = netdev_priv(dev);
738 
739 	list_del(&vlan->list);
740 	unregister_netdevice_queue(dev, head);
741 }
742 EXPORT_SYMBOL_GPL(macvlan_dellink);
743 
744 static int macvlan_changelink(struct net_device *dev,
745 		struct nlattr *tb[], struct nlattr *data[])
746 {
747 	struct macvlan_dev *vlan = netdev_priv(dev);
748 	if (data && data[IFLA_MACVLAN_MODE])
749 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
750 	return 0;
751 }
752 
753 static size_t macvlan_get_size(const struct net_device *dev)
754 {
755 	return nla_total_size(4);
756 }
757 
758 static int macvlan_fill_info(struct sk_buff *skb,
759 				const struct net_device *dev)
760 {
761 	struct macvlan_dev *vlan = netdev_priv(dev);
762 
763 	NLA_PUT_U32(skb, IFLA_MACVLAN_MODE, vlan->mode);
764 	return 0;
765 
766 nla_put_failure:
767 	return -EMSGSIZE;
768 }
769 
770 static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
771 	[IFLA_MACVLAN_MODE] = { .type = NLA_U32 },
772 };
773 
774 int macvlan_link_register(struct rtnl_link_ops *ops)
775 {
776 	/* common fields */
777 	ops->priv_size		= sizeof(struct macvlan_dev);
778 	ops->validate		= macvlan_validate;
779 	ops->maxtype		= IFLA_MACVLAN_MAX;
780 	ops->policy		= macvlan_policy;
781 	ops->changelink		= macvlan_changelink;
782 	ops->get_size		= macvlan_get_size;
783 	ops->fill_info		= macvlan_fill_info;
784 
785 	return rtnl_link_register(ops);
786 };
787 EXPORT_SYMBOL_GPL(macvlan_link_register);
788 
789 static struct rtnl_link_ops macvlan_link_ops = {
790 	.kind		= "macvlan",
791 	.setup		= macvlan_setup,
792 	.newlink	= macvlan_newlink,
793 	.dellink	= macvlan_dellink,
794 };
795 
796 static int macvlan_device_event(struct notifier_block *unused,
797 				unsigned long event, void *ptr)
798 {
799 	struct net_device *dev = ptr;
800 	struct macvlan_dev *vlan, *next;
801 	struct macvlan_port *port;
802 
803 	if (!macvlan_port_exists(dev))
804 		return NOTIFY_DONE;
805 
806 	port = macvlan_port_get(dev);
807 
808 	switch (event) {
809 	case NETDEV_CHANGE:
810 		list_for_each_entry(vlan, &port->vlans, list)
811 			netif_stacked_transfer_operstate(vlan->lowerdev,
812 							 vlan->dev);
813 		break;
814 	case NETDEV_FEAT_CHANGE:
815 		list_for_each_entry(vlan, &port->vlans, list) {
816 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
817 			vlan->dev->gso_max_size = dev->gso_max_size;
818 			netdev_features_change(vlan->dev);
819 		}
820 		break;
821 	case NETDEV_UNREGISTER:
822 		/* twiddle thumbs on netns device moves */
823 		if (dev->reg_state != NETREG_UNREGISTERING)
824 			break;
825 
826 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
827 			vlan->dev->rtnl_link_ops->dellink(vlan->dev, NULL);
828 		break;
829 	case NETDEV_PRE_TYPE_CHANGE:
830 		/* Forbid underlaying device to change its type. */
831 		return NOTIFY_BAD;
832 	}
833 	return NOTIFY_DONE;
834 }
835 
836 static struct notifier_block macvlan_notifier_block __read_mostly = {
837 	.notifier_call	= macvlan_device_event,
838 };
839 
840 static int __init macvlan_init_module(void)
841 {
842 	int err;
843 
844 	register_netdevice_notifier(&macvlan_notifier_block);
845 
846 	err = macvlan_link_register(&macvlan_link_ops);
847 	if (err < 0)
848 		goto err1;
849 	return 0;
850 err1:
851 	unregister_netdevice_notifier(&macvlan_notifier_block);
852 	return err;
853 }
854 
855 static void __exit macvlan_cleanup_module(void)
856 {
857 	rtnl_link_unregister(&macvlan_link_ops);
858 	unregister_netdevice_notifier(&macvlan_notifier_block);
859 }
860 
861 module_init(macvlan_init_module);
862 module_exit(macvlan_cleanup_module);
863 
864 MODULE_LICENSE("GPL");
865 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
866 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
867 MODULE_ALIAS_RTNL_LINK("macvlan");
868