xref: /openbmc/linux/drivers/net/macvlan.c (revision 7fe2f639)
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, bool sync)
74 {
75 	hlist_del_rcu(&vlan->hlist);
76 	if (sync)
77 		synchronize_rcu();
78 }
79 
80 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
81 					const unsigned char *addr)
82 {
83 	macvlan_hash_del(vlan, true);
84 	/* Now that we are unhashed it is safe to change the device
85 	 * address without confusing packet delivery.
86 	 */
87 	memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
88 	macvlan_hash_add(vlan);
89 }
90 
91 static int macvlan_addr_busy(const struct macvlan_port *port,
92 				const unsigned char *addr)
93 {
94 	/* Test to see if the specified multicast address is
95 	 * currently in use by the underlying device or
96 	 * another macvlan.
97 	 */
98 	if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
99 		return 1;
100 
101 	if (macvlan_hash_lookup(port, addr))
102 		return 1;
103 
104 	return 0;
105 }
106 
107 
108 static int macvlan_broadcast_one(struct sk_buff *skb,
109 				 const struct macvlan_dev *vlan,
110 				 const struct ethhdr *eth, bool local)
111 {
112 	struct net_device *dev = vlan->dev;
113 	if (!skb)
114 		return NET_RX_DROP;
115 
116 	if (local)
117 		return vlan->forward(dev, skb);
118 
119 	skb->dev = dev;
120 	if (!compare_ether_addr_64bits(eth->h_dest,
121 				       dev->broadcast))
122 		skb->pkt_type = PACKET_BROADCAST;
123 	else
124 		skb->pkt_type = PACKET_MULTICAST;
125 
126 	return vlan->receive(skb);
127 }
128 
129 static void macvlan_broadcast(struct sk_buff *skb,
130 			      const struct macvlan_port *port,
131 			      struct net_device *src,
132 			      enum macvlan_mode mode)
133 {
134 	const struct ethhdr *eth = eth_hdr(skb);
135 	const struct macvlan_dev *vlan;
136 	struct hlist_node *n;
137 	struct sk_buff *nskb;
138 	unsigned int i;
139 	int err;
140 
141 	if (skb->protocol == htons(ETH_P_PAUSE))
142 		return;
143 
144 	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
145 		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
146 			if (vlan->dev == src || !(vlan->mode & mode))
147 				continue;
148 
149 			nskb = skb_clone(skb, GFP_ATOMIC);
150 			err = macvlan_broadcast_one(nskb, vlan, eth,
151 					 mode == MACVLAN_MODE_BRIDGE);
152 			macvlan_count_rx(vlan, skb->len + ETH_HLEN,
153 					 err == NET_RX_SUCCESS, 1);
154 		}
155 	}
156 }
157 
158 /* called under rcu_read_lock() from netif_receive_skb */
159 static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
160 {
161 	struct macvlan_port *port;
162 	struct sk_buff *skb = *pskb;
163 	const struct ethhdr *eth = eth_hdr(skb);
164 	const struct macvlan_dev *vlan;
165 	const struct macvlan_dev *src;
166 	struct net_device *dev;
167 	unsigned int len = 0;
168 	int ret = NET_RX_DROP;
169 
170 	port = macvlan_port_get_rcu(skb->dev);
171 	if (is_multicast_ether_addr(eth->h_dest)) {
172 		src = macvlan_hash_lookup(port, eth->h_source);
173 		if (!src)
174 			/* frame comes from an external address */
175 			macvlan_broadcast(skb, port, NULL,
176 					  MACVLAN_MODE_PRIVATE |
177 					  MACVLAN_MODE_VEPA    |
178 					  MACVLAN_MODE_PASSTHRU|
179 					  MACVLAN_MODE_BRIDGE);
180 		else if (src->mode == MACVLAN_MODE_VEPA)
181 			/* flood to everyone except source */
182 			macvlan_broadcast(skb, port, src->dev,
183 					  MACVLAN_MODE_VEPA |
184 					  MACVLAN_MODE_BRIDGE);
185 		else if (src->mode == MACVLAN_MODE_BRIDGE)
186 			/*
187 			 * flood only to VEPA ports, bridge ports
188 			 * already saw the frame on the way out.
189 			 */
190 			macvlan_broadcast(skb, port, src->dev,
191 					  MACVLAN_MODE_VEPA);
192 		return RX_HANDLER_PASS;
193 	}
194 
195 	if (port->passthru)
196 		vlan = list_first_entry(&port->vlans, struct macvlan_dev, list);
197 	else
198 		vlan = macvlan_hash_lookup(port, eth->h_dest);
199 	if (vlan == NULL)
200 		return RX_HANDLER_PASS;
201 
202 	dev = vlan->dev;
203 	if (unlikely(!(dev->flags & IFF_UP))) {
204 		kfree_skb(skb);
205 		return RX_HANDLER_CONSUMED;
206 	}
207 	len = skb->len + ETH_HLEN;
208 	skb = skb_share_check(skb, GFP_ATOMIC);
209 	if (!skb)
210 		goto out;
211 
212 	skb->dev = dev;
213 	skb->pkt_type = PACKET_HOST;
214 
215 	ret = vlan->receive(skb);
216 
217 out:
218 	macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);
219 	return RX_HANDLER_CONSUMED;
220 }
221 
222 static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
223 {
224 	const struct macvlan_dev *vlan = netdev_priv(dev);
225 	const struct macvlan_port *port = vlan->port;
226 	const struct macvlan_dev *dest;
227 	__u8 ip_summed = skb->ip_summed;
228 
229 	if (vlan->mode == MACVLAN_MODE_BRIDGE) {
230 		const struct ethhdr *eth = (void *)skb->data;
231 		skb->ip_summed = CHECKSUM_UNNECESSARY;
232 
233 		/* send to other bridge ports directly */
234 		if (is_multicast_ether_addr(eth->h_dest)) {
235 			macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
236 			goto xmit_world;
237 		}
238 
239 		dest = macvlan_hash_lookup(port, eth->h_dest);
240 		if (dest && dest->mode == MACVLAN_MODE_BRIDGE) {
241 			/* send to lowerdev first for its network taps */
242 			vlan->forward(vlan->lowerdev, skb);
243 
244 			return NET_XMIT_SUCCESS;
245 		}
246 	}
247 
248 xmit_world:
249 	skb->ip_summed = ip_summed;
250 	skb_set_dev(skb, vlan->lowerdev);
251 	return dev_queue_xmit(skb);
252 }
253 
254 netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
255 			       struct net_device *dev)
256 {
257 	unsigned int len = skb->len;
258 	int ret;
259 	const struct macvlan_dev *vlan = netdev_priv(dev);
260 
261 	ret = macvlan_queue_xmit(skb, dev);
262 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
263 		struct macvlan_pcpu_stats *pcpu_stats;
264 
265 		pcpu_stats = this_cpu_ptr(vlan->pcpu_stats);
266 		u64_stats_update_begin(&pcpu_stats->syncp);
267 		pcpu_stats->tx_packets++;
268 		pcpu_stats->tx_bytes += len;
269 		u64_stats_update_end(&pcpu_stats->syncp);
270 	} else {
271 		this_cpu_inc(vlan->pcpu_stats->tx_dropped);
272 	}
273 	return ret;
274 }
275 EXPORT_SYMBOL_GPL(macvlan_start_xmit);
276 
277 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
278 			       unsigned short type, const void *daddr,
279 			       const void *saddr, unsigned len)
280 {
281 	const struct macvlan_dev *vlan = netdev_priv(dev);
282 	struct net_device *lowerdev = vlan->lowerdev;
283 
284 	return dev_hard_header(skb, lowerdev, type, daddr,
285 			       saddr ? : dev->dev_addr, len);
286 }
287 
288 static const struct header_ops macvlan_hard_header_ops = {
289 	.create  	= macvlan_hard_header,
290 	.rebuild	= eth_rebuild_header,
291 	.parse		= eth_header_parse,
292 	.cache		= eth_header_cache,
293 	.cache_update	= eth_header_cache_update,
294 };
295 
296 static int macvlan_open(struct net_device *dev)
297 {
298 	struct macvlan_dev *vlan = netdev_priv(dev);
299 	struct net_device *lowerdev = vlan->lowerdev;
300 	int err;
301 
302 	if (vlan->port->passthru) {
303 		dev_set_promiscuity(lowerdev, 1);
304 		goto hash_add;
305 	}
306 
307 	err = -EBUSY;
308 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
309 		goto out;
310 
311 	err = dev_uc_add(lowerdev, dev->dev_addr);
312 	if (err < 0)
313 		goto out;
314 	if (dev->flags & IFF_ALLMULTI) {
315 		err = dev_set_allmulti(lowerdev, 1);
316 		if (err < 0)
317 			goto del_unicast;
318 	}
319 
320 hash_add:
321 	macvlan_hash_add(vlan);
322 	return 0;
323 
324 del_unicast:
325 	dev_uc_del(lowerdev, dev->dev_addr);
326 out:
327 	return err;
328 }
329 
330 static int macvlan_stop(struct net_device *dev)
331 {
332 	struct macvlan_dev *vlan = netdev_priv(dev);
333 	struct net_device *lowerdev = vlan->lowerdev;
334 
335 	if (vlan->port->passthru) {
336 		dev_set_promiscuity(lowerdev, -1);
337 		goto hash_del;
338 	}
339 
340 	dev_mc_unsync(lowerdev, dev);
341 	if (dev->flags & IFF_ALLMULTI)
342 		dev_set_allmulti(lowerdev, -1);
343 
344 	dev_uc_del(lowerdev, dev->dev_addr);
345 
346 hash_del:
347 	macvlan_hash_del(vlan, !dev->dismantle);
348 	return 0;
349 }
350 
351 static int macvlan_set_mac_address(struct net_device *dev, void *p)
352 {
353 	struct macvlan_dev *vlan = netdev_priv(dev);
354 	struct net_device *lowerdev = vlan->lowerdev;
355 	struct sockaddr *addr = p;
356 	int err;
357 
358 	if (!is_valid_ether_addr(addr->sa_data))
359 		return -EADDRNOTAVAIL;
360 
361 	if (!(dev->flags & IFF_UP)) {
362 		/* Just copy in the new address */
363 		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
364 	} else {
365 		/* Rehash and update the device filters */
366 		if (macvlan_addr_busy(vlan->port, addr->sa_data))
367 			return -EBUSY;
368 
369 		err = dev_uc_add(lowerdev, addr->sa_data);
370 		if (err)
371 			return err;
372 
373 		dev_uc_del(lowerdev, dev->dev_addr);
374 
375 		macvlan_hash_change_addr(vlan, addr->sa_data);
376 	}
377 	return 0;
378 }
379 
380 static void macvlan_change_rx_flags(struct net_device *dev, int change)
381 {
382 	struct macvlan_dev *vlan = netdev_priv(dev);
383 	struct net_device *lowerdev = vlan->lowerdev;
384 
385 	if (change & IFF_ALLMULTI)
386 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
387 }
388 
389 static void macvlan_set_multicast_list(struct net_device *dev)
390 {
391 	struct macvlan_dev *vlan = netdev_priv(dev);
392 
393 	dev_mc_sync(vlan->lowerdev, dev);
394 }
395 
396 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
397 {
398 	struct macvlan_dev *vlan = netdev_priv(dev);
399 
400 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
401 		return -EINVAL;
402 	dev->mtu = new_mtu;
403 	return 0;
404 }
405 
406 /*
407  * macvlan network devices have devices nesting below it and are a special
408  * "super class" of normal network devices; split their locks off into a
409  * separate class since they always nest.
410  */
411 static struct lock_class_key macvlan_netdev_xmit_lock_key;
412 static struct lock_class_key macvlan_netdev_addr_lock_key;
413 
414 #define MACVLAN_FEATURES \
415 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
416 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
417 	 NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO | NETIF_F_RXCSUM)
418 
419 #define MACVLAN_STATE_MASK \
420 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
421 
422 static void macvlan_set_lockdep_class_one(struct net_device *dev,
423 					  struct netdev_queue *txq,
424 					  void *_unused)
425 {
426 	lockdep_set_class(&txq->_xmit_lock,
427 			  &macvlan_netdev_xmit_lock_key);
428 }
429 
430 static void macvlan_set_lockdep_class(struct net_device *dev)
431 {
432 	lockdep_set_class(&dev->addr_list_lock,
433 			  &macvlan_netdev_addr_lock_key);
434 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
435 }
436 
437 static int macvlan_init(struct net_device *dev)
438 {
439 	struct macvlan_dev *vlan = netdev_priv(dev);
440 	const struct net_device *lowerdev = vlan->lowerdev;
441 
442 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
443 				  (lowerdev->state & MACVLAN_STATE_MASK);
444 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
445 	dev->features		|= NETIF_F_LLTX;
446 	dev->gso_max_size	= lowerdev->gso_max_size;
447 	dev->iflink		= lowerdev->ifindex;
448 	dev->hard_header_len	= lowerdev->hard_header_len;
449 
450 	macvlan_set_lockdep_class(dev);
451 
452 	vlan->pcpu_stats = alloc_percpu(struct macvlan_pcpu_stats);
453 	if (!vlan->pcpu_stats)
454 		return -ENOMEM;
455 
456 	return 0;
457 }
458 
459 static void macvlan_uninit(struct net_device *dev)
460 {
461 	struct macvlan_dev *vlan = netdev_priv(dev);
462 	struct macvlan_port *port = vlan->port;
463 
464 	free_percpu(vlan->pcpu_stats);
465 
466 	port->count -= 1;
467 	if (!port->count)
468 		macvlan_port_destroy(port->dev);
469 }
470 
471 static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
472 							 struct rtnl_link_stats64 *stats)
473 {
474 	struct macvlan_dev *vlan = netdev_priv(dev);
475 
476 	if (vlan->pcpu_stats) {
477 		struct macvlan_pcpu_stats *p;
478 		u64 rx_packets, rx_bytes, rx_multicast, tx_packets, tx_bytes;
479 		u32 rx_errors = 0, tx_dropped = 0;
480 		unsigned int start;
481 		int i;
482 
483 		for_each_possible_cpu(i) {
484 			p = per_cpu_ptr(vlan->pcpu_stats, i);
485 			do {
486 				start = u64_stats_fetch_begin_bh(&p->syncp);
487 				rx_packets	= p->rx_packets;
488 				rx_bytes	= p->rx_bytes;
489 				rx_multicast	= p->rx_multicast;
490 				tx_packets	= p->tx_packets;
491 				tx_bytes	= p->tx_bytes;
492 			} while (u64_stats_fetch_retry_bh(&p->syncp, start));
493 
494 			stats->rx_packets	+= rx_packets;
495 			stats->rx_bytes		+= rx_bytes;
496 			stats->multicast	+= rx_multicast;
497 			stats->tx_packets	+= tx_packets;
498 			stats->tx_bytes		+= tx_bytes;
499 			/* rx_errors & tx_dropped are u32, updated
500 			 * without syncp protection.
501 			 */
502 			rx_errors	+= p->rx_errors;
503 			tx_dropped	+= p->tx_dropped;
504 		}
505 		stats->rx_errors	= rx_errors;
506 		stats->rx_dropped	= rx_errors;
507 		stats->tx_dropped	= tx_dropped;
508 	}
509 	return stats;
510 }
511 
512 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
513 					struct ethtool_drvinfo *drvinfo)
514 {
515 	snprintf(drvinfo->driver, 32, "macvlan");
516 	snprintf(drvinfo->version, 32, "0.1");
517 }
518 
519 static int macvlan_ethtool_get_settings(struct net_device *dev,
520 					struct ethtool_cmd *cmd)
521 {
522 	const struct macvlan_dev *vlan = netdev_priv(dev);
523 	return dev_ethtool_get_settings(vlan->lowerdev, cmd);
524 }
525 
526 static const struct ethtool_ops macvlan_ethtool_ops = {
527 	.get_link		= ethtool_op_get_link,
528 	.get_settings		= macvlan_ethtool_get_settings,
529 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
530 };
531 
532 static const struct net_device_ops macvlan_netdev_ops = {
533 	.ndo_init		= macvlan_init,
534 	.ndo_uninit		= macvlan_uninit,
535 	.ndo_open		= macvlan_open,
536 	.ndo_stop		= macvlan_stop,
537 	.ndo_start_xmit		= macvlan_start_xmit,
538 	.ndo_change_mtu		= macvlan_change_mtu,
539 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
540 	.ndo_set_mac_address	= macvlan_set_mac_address,
541 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
542 	.ndo_get_stats64	= macvlan_dev_get_stats64,
543 	.ndo_validate_addr	= eth_validate_addr,
544 };
545 
546 void macvlan_common_setup(struct net_device *dev)
547 {
548 	ether_setup(dev);
549 
550 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
551 	dev->netdev_ops		= &macvlan_netdev_ops;
552 	dev->destructor		= free_netdev;
553 	dev->header_ops		= &macvlan_hard_header_ops,
554 	dev->ethtool_ops	= &macvlan_ethtool_ops;
555 }
556 EXPORT_SYMBOL_GPL(macvlan_common_setup);
557 
558 static void macvlan_setup(struct net_device *dev)
559 {
560 	macvlan_common_setup(dev);
561 	dev->tx_queue_len	= 0;
562 }
563 
564 static int macvlan_port_create(struct net_device *dev)
565 {
566 	struct macvlan_port *port;
567 	unsigned int i;
568 	int err;
569 
570 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
571 		return -EINVAL;
572 
573 	port = kzalloc(sizeof(*port), GFP_KERNEL);
574 	if (port == NULL)
575 		return -ENOMEM;
576 
577 	port->passthru = false;
578 	port->dev = dev;
579 	INIT_LIST_HEAD(&port->vlans);
580 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
581 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
582 
583 	err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
584 	if (err)
585 		kfree(port);
586 	else
587 		dev->priv_flags |= IFF_MACVLAN_PORT;
588 	return err;
589 }
590 
591 static void macvlan_port_destroy(struct net_device *dev)
592 {
593 	struct macvlan_port *port = macvlan_port_get(dev);
594 
595 	dev->priv_flags &= ~IFF_MACVLAN_PORT;
596 	netdev_rx_handler_unregister(dev);
597 	kfree_rcu(port, rcu);
598 }
599 
600 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
601 {
602 	if (tb[IFLA_ADDRESS]) {
603 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
604 			return -EINVAL;
605 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
606 			return -EADDRNOTAVAIL;
607 	}
608 
609 	if (data && data[IFLA_MACVLAN_MODE]) {
610 		switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
611 		case MACVLAN_MODE_PRIVATE:
612 		case MACVLAN_MODE_VEPA:
613 		case MACVLAN_MODE_BRIDGE:
614 		case MACVLAN_MODE_PASSTHRU:
615 			break;
616 		default:
617 			return -EINVAL;
618 		}
619 	}
620 	return 0;
621 }
622 
623 int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
624 			   struct nlattr *tb[], struct nlattr *data[],
625 			   int (*receive)(struct sk_buff *skb),
626 			   int (*forward)(struct net_device *dev,
627 					  struct sk_buff *skb))
628 {
629 	struct macvlan_dev *vlan = netdev_priv(dev);
630 	struct macvlan_port *port;
631 	struct net_device *lowerdev;
632 	int err;
633 
634 	if (!tb[IFLA_LINK])
635 		return -EINVAL;
636 
637 	lowerdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
638 	if (lowerdev == NULL)
639 		return -ENODEV;
640 
641 	/* When creating macvlans on top of other macvlans - use
642 	 * the real device as the lowerdev.
643 	 */
644 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
645 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
646 		lowerdev = lowervlan->lowerdev;
647 	}
648 
649 	if (!tb[IFLA_MTU])
650 		dev->mtu = lowerdev->mtu;
651 	else if (dev->mtu > lowerdev->mtu)
652 		return -EINVAL;
653 
654 	if (!tb[IFLA_ADDRESS])
655 		random_ether_addr(dev->dev_addr);
656 
657 	if (!macvlan_port_exists(lowerdev)) {
658 		err = macvlan_port_create(lowerdev);
659 		if (err < 0)
660 			return err;
661 	}
662 	port = macvlan_port_get(lowerdev);
663 
664 	/* Only 1 macvlan device can be created in passthru mode */
665 	if (port->passthru)
666 		return -EINVAL;
667 
668 	vlan->lowerdev = lowerdev;
669 	vlan->dev      = dev;
670 	vlan->port     = port;
671 	vlan->receive  = receive;
672 	vlan->forward  = forward;
673 
674 	vlan->mode     = MACVLAN_MODE_VEPA;
675 	if (data && data[IFLA_MACVLAN_MODE])
676 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
677 
678 	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
679 		if (port->count)
680 			return -EINVAL;
681 		port->passthru = true;
682 		memcpy(dev->dev_addr, lowerdev->dev_addr, ETH_ALEN);
683 	}
684 
685 	port->count += 1;
686 	err = register_netdevice(dev);
687 	if (err < 0)
688 		goto destroy_port;
689 
690 	list_add_tail(&vlan->list, &port->vlans);
691 	netif_stacked_transfer_operstate(lowerdev, dev);
692 
693 	return 0;
694 
695 destroy_port:
696 	port->count -= 1;
697 	if (!port->count)
698 		macvlan_port_destroy(lowerdev);
699 
700 	return err;
701 }
702 EXPORT_SYMBOL_GPL(macvlan_common_newlink);
703 
704 static int macvlan_newlink(struct net *src_net, struct net_device *dev,
705 			   struct nlattr *tb[], struct nlattr *data[])
706 {
707 	return macvlan_common_newlink(src_net, dev, tb, data,
708 				      netif_rx,
709 				      dev_forward_skb);
710 }
711 
712 void macvlan_dellink(struct net_device *dev, struct list_head *head)
713 {
714 	struct macvlan_dev *vlan = netdev_priv(dev);
715 
716 	list_del(&vlan->list);
717 	unregister_netdevice_queue(dev, head);
718 }
719 EXPORT_SYMBOL_GPL(macvlan_dellink);
720 
721 static int macvlan_changelink(struct net_device *dev,
722 		struct nlattr *tb[], struct nlattr *data[])
723 {
724 	struct macvlan_dev *vlan = netdev_priv(dev);
725 	if (data && data[IFLA_MACVLAN_MODE])
726 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
727 	return 0;
728 }
729 
730 static size_t macvlan_get_size(const struct net_device *dev)
731 {
732 	return nla_total_size(4);
733 }
734 
735 static int macvlan_fill_info(struct sk_buff *skb,
736 				const struct net_device *dev)
737 {
738 	struct macvlan_dev *vlan = netdev_priv(dev);
739 
740 	NLA_PUT_U32(skb, IFLA_MACVLAN_MODE, vlan->mode);
741 	return 0;
742 
743 nla_put_failure:
744 	return -EMSGSIZE;
745 }
746 
747 static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
748 	[IFLA_MACVLAN_MODE] = { .type = NLA_U32 },
749 };
750 
751 int macvlan_link_register(struct rtnl_link_ops *ops)
752 {
753 	/* common fields */
754 	ops->priv_size		= sizeof(struct macvlan_dev);
755 	ops->validate		= macvlan_validate;
756 	ops->maxtype		= IFLA_MACVLAN_MAX;
757 	ops->policy		= macvlan_policy;
758 	ops->changelink		= macvlan_changelink;
759 	ops->get_size		= macvlan_get_size;
760 	ops->fill_info		= macvlan_fill_info;
761 
762 	return rtnl_link_register(ops);
763 };
764 EXPORT_SYMBOL_GPL(macvlan_link_register);
765 
766 static struct rtnl_link_ops macvlan_link_ops = {
767 	.kind		= "macvlan",
768 	.setup		= macvlan_setup,
769 	.newlink	= macvlan_newlink,
770 	.dellink	= macvlan_dellink,
771 };
772 
773 static int macvlan_device_event(struct notifier_block *unused,
774 				unsigned long event, void *ptr)
775 {
776 	struct net_device *dev = ptr;
777 	struct macvlan_dev *vlan, *next;
778 	struct macvlan_port *port;
779 	LIST_HEAD(list_kill);
780 
781 	if (!macvlan_port_exists(dev))
782 		return NOTIFY_DONE;
783 
784 	port = macvlan_port_get(dev);
785 
786 	switch (event) {
787 	case NETDEV_CHANGE:
788 		list_for_each_entry(vlan, &port->vlans, list)
789 			netif_stacked_transfer_operstate(vlan->lowerdev,
790 							 vlan->dev);
791 		break;
792 	case NETDEV_FEAT_CHANGE:
793 		list_for_each_entry(vlan, &port->vlans, list) {
794 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
795 			vlan->dev->gso_max_size = dev->gso_max_size;
796 			netdev_features_change(vlan->dev);
797 		}
798 		break;
799 	case NETDEV_UNREGISTER:
800 		/* twiddle thumbs on netns device moves */
801 		if (dev->reg_state != NETREG_UNREGISTERING)
802 			break;
803 
804 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
805 			vlan->dev->rtnl_link_ops->dellink(vlan->dev, &list_kill);
806 		unregister_netdevice_many(&list_kill);
807 		list_del(&list_kill);
808 		break;
809 	case NETDEV_PRE_TYPE_CHANGE:
810 		/* Forbid underlaying device to change its type. */
811 		return NOTIFY_BAD;
812 	}
813 	return NOTIFY_DONE;
814 }
815 
816 static struct notifier_block macvlan_notifier_block __read_mostly = {
817 	.notifier_call	= macvlan_device_event,
818 };
819 
820 static int __init macvlan_init_module(void)
821 {
822 	int err;
823 
824 	register_netdevice_notifier(&macvlan_notifier_block);
825 
826 	err = macvlan_link_register(&macvlan_link_ops);
827 	if (err < 0)
828 		goto err1;
829 	return 0;
830 err1:
831 	unregister_netdevice_notifier(&macvlan_notifier_block);
832 	return err;
833 }
834 
835 static void __exit macvlan_cleanup_module(void)
836 {
837 	rtnl_link_unregister(&macvlan_link_ops);
838 	unregister_netdevice_notifier(&macvlan_notifier_block);
839 }
840 
841 module_init(macvlan_init_module);
842 module_exit(macvlan_cleanup_module);
843 
844 MODULE_LICENSE("GPL");
845 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
846 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
847 MODULE_ALIAS_RTNL_LINK("macvlan");
848