xref: /openbmc/linux/drivers/net/macvlan.c (revision 8ac727c1)
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 };
43 
44 #define macvlan_port_get_rcu(dev) \
45 	((struct macvlan_port *) rcu_dereference(dev->rx_handler_data))
46 #define macvlan_port_get(dev) ((struct macvlan_port *) dev->rx_handler_data)
47 #define macvlan_port_exists(dev) (dev->priv_flags & IFF_MACVLAN_PORT)
48 
49 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
50 					       const unsigned char *addr)
51 {
52 	struct macvlan_dev *vlan;
53 	struct hlist_node *n;
54 
55 	hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
56 		if (!compare_ether_addr_64bits(vlan->dev->dev_addr, addr))
57 			return vlan;
58 	}
59 	return NULL;
60 }
61 
62 static void macvlan_hash_add(struct macvlan_dev *vlan)
63 {
64 	struct macvlan_port *port = vlan->port;
65 	const unsigned char *addr = vlan->dev->dev_addr;
66 
67 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
68 }
69 
70 static void macvlan_hash_del(struct macvlan_dev *vlan)
71 {
72 	hlist_del_rcu(&vlan->hlist);
73 	synchronize_rcu();
74 }
75 
76 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
77 					const unsigned char *addr)
78 {
79 	macvlan_hash_del(vlan);
80 	/* Now that we are unhashed it is safe to change the device
81 	 * address without confusing packet delivery.
82 	 */
83 	memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
84 	macvlan_hash_add(vlan);
85 }
86 
87 static int macvlan_addr_busy(const struct macvlan_port *port,
88 				const unsigned char *addr)
89 {
90 	/* Test to see if the specified multicast address is
91 	 * currently in use by the underlying device or
92 	 * another macvlan.
93 	 */
94 	if (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
95 		return 1;
96 
97 	if (macvlan_hash_lookup(port, addr))
98 		return 1;
99 
100 	return 0;
101 }
102 
103 
104 static int macvlan_broadcast_one(struct sk_buff *skb,
105 				 const struct macvlan_dev *vlan,
106 				 const struct ethhdr *eth, bool local)
107 {
108 	struct net_device *dev = vlan->dev;
109 	if (!skb)
110 		return NET_RX_DROP;
111 
112 	if (local)
113 		return vlan->forward(dev, skb);
114 
115 	skb->dev = dev;
116 	if (!compare_ether_addr_64bits(eth->h_dest,
117 				       dev->broadcast))
118 		skb->pkt_type = PACKET_BROADCAST;
119 	else
120 		skb->pkt_type = PACKET_MULTICAST;
121 
122 	return vlan->receive(skb);
123 }
124 
125 static void macvlan_broadcast(struct sk_buff *skb,
126 			      const struct macvlan_port *port,
127 			      struct net_device *src,
128 			      enum macvlan_mode mode)
129 {
130 	const struct ethhdr *eth = eth_hdr(skb);
131 	const struct macvlan_dev *vlan;
132 	struct hlist_node *n;
133 	struct sk_buff *nskb;
134 	unsigned int i;
135 	int err;
136 
137 	if (skb->protocol == htons(ETH_P_PAUSE))
138 		return;
139 
140 	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
141 		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
142 			if (vlan->dev == src || !(vlan->mode & mode))
143 				continue;
144 
145 			nskb = skb_clone(skb, GFP_ATOMIC);
146 			err = macvlan_broadcast_one(nskb, vlan, eth,
147 					 mode == MACVLAN_MODE_BRIDGE);
148 			macvlan_count_rx(vlan, skb->len + ETH_HLEN,
149 					 err == NET_RX_SUCCESS, 1);
150 		}
151 	}
152 }
153 
154 /* called under rcu_read_lock() from netif_receive_skb */
155 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
156 {
157 	struct macvlan_port *port;
158 	const struct ethhdr *eth = eth_hdr(skb);
159 	const struct macvlan_dev *vlan;
160 	const struct macvlan_dev *src;
161 	struct net_device *dev;
162 	unsigned int len = 0;
163 	int ret = NET_RX_DROP;
164 
165 	port = macvlan_port_get_rcu(skb->dev);
166 	if (is_multicast_ether_addr(eth->h_dest)) {
167 		src = macvlan_hash_lookup(port, eth->h_source);
168 		if (!src)
169 			/* frame comes from an external address */
170 			macvlan_broadcast(skb, port, NULL,
171 					  MACVLAN_MODE_PRIVATE |
172 					  MACVLAN_MODE_VEPA    |
173 					  MACVLAN_MODE_PASSTHRU|
174 					  MACVLAN_MODE_BRIDGE);
175 		else if (src->mode == MACVLAN_MODE_VEPA)
176 			/* flood to everyone except source */
177 			macvlan_broadcast(skb, port, src->dev,
178 					  MACVLAN_MODE_VEPA |
179 					  MACVLAN_MODE_BRIDGE);
180 		else if (src->mode == MACVLAN_MODE_BRIDGE)
181 			/*
182 			 * flood only to VEPA ports, bridge ports
183 			 * already saw the frame on the way out.
184 			 */
185 			macvlan_broadcast(skb, port, src->dev,
186 					  MACVLAN_MODE_VEPA);
187 		return skb;
188 	}
189 
190 	if (port->passthru)
191 		vlan = list_first_entry(&port->vlans, struct macvlan_dev, list);
192 	else
193 		vlan = macvlan_hash_lookup(port, eth->h_dest);
194 	if (vlan == NULL)
195 		return skb;
196 
197 	dev = vlan->dev;
198 	if (unlikely(!(dev->flags & IFF_UP))) {
199 		kfree_skb(skb);
200 		return NULL;
201 	}
202 	len = skb->len + ETH_HLEN;
203 	skb = skb_share_check(skb, GFP_ATOMIC);
204 	if (!skb)
205 		goto out;
206 
207 	skb->dev = dev;
208 	skb->pkt_type = PACKET_HOST;
209 
210 	ret = vlan->receive(skb);
211 
212 out:
213 	macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, 0);
214 	return NULL;
215 }
216 
217 static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
218 {
219 	const struct macvlan_dev *vlan = netdev_priv(dev);
220 	const struct macvlan_port *port = vlan->port;
221 	const struct macvlan_dev *dest;
222 
223 	if (vlan->mode == MACVLAN_MODE_BRIDGE) {
224 		const struct ethhdr *eth = (void *)skb->data;
225 
226 		/* send to other bridge ports directly */
227 		if (is_multicast_ether_addr(eth->h_dest)) {
228 			macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
229 			goto xmit_world;
230 		}
231 
232 		dest = macvlan_hash_lookup(port, eth->h_dest);
233 		if (dest && dest->mode == MACVLAN_MODE_BRIDGE) {
234 			unsigned int length = skb->len + ETH_HLEN;
235 			int ret = dest->forward(dest->dev, skb);
236 			macvlan_count_rx(dest, length,
237 					 ret == NET_RX_SUCCESS, 0);
238 
239 			return NET_XMIT_SUCCESS;
240 		}
241 	}
242 
243 xmit_world:
244 	skb_set_dev(skb, vlan->lowerdev);
245 	return dev_queue_xmit(skb);
246 }
247 
248 netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
249 			       struct net_device *dev)
250 {
251 	unsigned int len = skb->len;
252 	int ret;
253 	const struct macvlan_dev *vlan = netdev_priv(dev);
254 
255 	ret = macvlan_queue_xmit(skb, dev);
256 	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
257 		struct macvlan_pcpu_stats *pcpu_stats;
258 
259 		pcpu_stats = this_cpu_ptr(vlan->pcpu_stats);
260 		u64_stats_update_begin(&pcpu_stats->syncp);
261 		pcpu_stats->tx_packets++;
262 		pcpu_stats->tx_bytes += len;
263 		u64_stats_update_end(&pcpu_stats->syncp);
264 	} else {
265 		this_cpu_inc(vlan->pcpu_stats->tx_dropped);
266 	}
267 	return ret;
268 }
269 EXPORT_SYMBOL_GPL(macvlan_start_xmit);
270 
271 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
272 			       unsigned short type, const void *daddr,
273 			       const void *saddr, unsigned len)
274 {
275 	const struct macvlan_dev *vlan = netdev_priv(dev);
276 	struct net_device *lowerdev = vlan->lowerdev;
277 
278 	return dev_hard_header(skb, lowerdev, type, daddr,
279 			       saddr ? : dev->dev_addr, len);
280 }
281 
282 static const struct header_ops macvlan_hard_header_ops = {
283 	.create  	= macvlan_hard_header,
284 	.rebuild	= eth_rebuild_header,
285 	.parse		= eth_header_parse,
286 	.cache		= eth_header_cache,
287 	.cache_update	= eth_header_cache_update,
288 };
289 
290 static int macvlan_open(struct net_device *dev)
291 {
292 	struct macvlan_dev *vlan = netdev_priv(dev);
293 	struct net_device *lowerdev = vlan->lowerdev;
294 	int err;
295 
296 	if (vlan->port->passthru) {
297 		dev_set_promiscuity(lowerdev, 1);
298 		goto hash_add;
299 	}
300 
301 	err = -EBUSY;
302 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
303 		goto out;
304 
305 	err = dev_uc_add(lowerdev, dev->dev_addr);
306 	if (err < 0)
307 		goto out;
308 	if (dev->flags & IFF_ALLMULTI) {
309 		err = dev_set_allmulti(lowerdev, 1);
310 		if (err < 0)
311 			goto del_unicast;
312 	}
313 
314 hash_add:
315 	macvlan_hash_add(vlan);
316 	return 0;
317 
318 del_unicast:
319 	dev_uc_del(lowerdev, dev->dev_addr);
320 out:
321 	return err;
322 }
323 
324 static int macvlan_stop(struct net_device *dev)
325 {
326 	struct macvlan_dev *vlan = netdev_priv(dev);
327 	struct net_device *lowerdev = vlan->lowerdev;
328 
329 	if (vlan->port->passthru) {
330 		dev_set_promiscuity(lowerdev, -1);
331 		goto hash_del;
332 	}
333 
334 	dev_mc_unsync(lowerdev, dev);
335 	if (dev->flags & IFF_ALLMULTI)
336 		dev_set_allmulti(lowerdev, -1);
337 
338 	dev_uc_del(lowerdev, dev->dev_addr);
339 
340 hash_del:
341 	macvlan_hash_del(vlan);
342 	return 0;
343 }
344 
345 static int macvlan_set_mac_address(struct net_device *dev, void *p)
346 {
347 	struct macvlan_dev *vlan = netdev_priv(dev);
348 	struct net_device *lowerdev = vlan->lowerdev;
349 	struct sockaddr *addr = p;
350 	int err;
351 
352 	if (!is_valid_ether_addr(addr->sa_data))
353 		return -EADDRNOTAVAIL;
354 
355 	if (!(dev->flags & IFF_UP)) {
356 		/* Just copy in the new address */
357 		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
358 	} else {
359 		/* Rehash and update the device filters */
360 		if (macvlan_addr_busy(vlan->port, addr->sa_data))
361 			return -EBUSY;
362 
363 		err = dev_uc_add(lowerdev, addr->sa_data);
364 		if (err)
365 			return err;
366 
367 		dev_uc_del(lowerdev, dev->dev_addr);
368 
369 		macvlan_hash_change_addr(vlan, addr->sa_data);
370 	}
371 	return 0;
372 }
373 
374 static void macvlan_change_rx_flags(struct net_device *dev, int change)
375 {
376 	struct macvlan_dev *vlan = netdev_priv(dev);
377 	struct net_device *lowerdev = vlan->lowerdev;
378 
379 	if (change & IFF_ALLMULTI)
380 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
381 }
382 
383 static void macvlan_set_multicast_list(struct net_device *dev)
384 {
385 	struct macvlan_dev *vlan = netdev_priv(dev);
386 
387 	dev_mc_sync(vlan->lowerdev, dev);
388 }
389 
390 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
391 {
392 	struct macvlan_dev *vlan = netdev_priv(dev);
393 
394 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
395 		return -EINVAL;
396 	dev->mtu = new_mtu;
397 	return 0;
398 }
399 
400 /*
401  * macvlan network devices have devices nesting below it and are a special
402  * "super class" of normal network devices; split their locks off into a
403  * separate class since they always nest.
404  */
405 static struct lock_class_key macvlan_netdev_xmit_lock_key;
406 static struct lock_class_key macvlan_netdev_addr_lock_key;
407 
408 #define MACVLAN_FEATURES \
409 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
410 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
411 	 NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO)
412 
413 #define MACVLAN_STATE_MASK \
414 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
415 
416 static void macvlan_set_lockdep_class_one(struct net_device *dev,
417 					  struct netdev_queue *txq,
418 					  void *_unused)
419 {
420 	lockdep_set_class(&txq->_xmit_lock,
421 			  &macvlan_netdev_xmit_lock_key);
422 }
423 
424 static void macvlan_set_lockdep_class(struct net_device *dev)
425 {
426 	lockdep_set_class(&dev->addr_list_lock,
427 			  &macvlan_netdev_addr_lock_key);
428 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
429 }
430 
431 static int macvlan_init(struct net_device *dev)
432 {
433 	struct macvlan_dev *vlan = netdev_priv(dev);
434 	const struct net_device *lowerdev = vlan->lowerdev;
435 
436 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
437 				  (lowerdev->state & MACVLAN_STATE_MASK);
438 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
439 	dev->features		|= NETIF_F_LLTX;
440 	dev->gso_max_size	= lowerdev->gso_max_size;
441 	dev->iflink		= lowerdev->ifindex;
442 	dev->hard_header_len	= lowerdev->hard_header_len;
443 
444 	macvlan_set_lockdep_class(dev);
445 
446 	vlan->pcpu_stats = alloc_percpu(struct macvlan_pcpu_stats);
447 	if (!vlan->pcpu_stats)
448 		return -ENOMEM;
449 
450 	return 0;
451 }
452 
453 static void macvlan_uninit(struct net_device *dev)
454 {
455 	struct macvlan_dev *vlan = netdev_priv(dev);
456 
457 	free_percpu(vlan->pcpu_stats);
458 }
459 
460 static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
461 							 struct rtnl_link_stats64 *stats)
462 {
463 	struct macvlan_dev *vlan = netdev_priv(dev);
464 
465 	if (vlan->pcpu_stats) {
466 		struct macvlan_pcpu_stats *p;
467 		u64 rx_packets, rx_bytes, rx_multicast, tx_packets, tx_bytes;
468 		u32 rx_errors = 0, tx_dropped = 0;
469 		unsigned int start;
470 		int i;
471 
472 		for_each_possible_cpu(i) {
473 			p = per_cpu_ptr(vlan->pcpu_stats, i);
474 			do {
475 				start = u64_stats_fetch_begin_bh(&p->syncp);
476 				rx_packets	= p->rx_packets;
477 				rx_bytes	= p->rx_bytes;
478 				rx_multicast	= p->rx_multicast;
479 				tx_packets	= p->tx_packets;
480 				tx_bytes	= p->tx_bytes;
481 			} while (u64_stats_fetch_retry_bh(&p->syncp, start));
482 
483 			stats->rx_packets	+= rx_packets;
484 			stats->rx_bytes		+= rx_bytes;
485 			stats->multicast	+= rx_multicast;
486 			stats->tx_packets	+= tx_packets;
487 			stats->tx_bytes		+= tx_bytes;
488 			/* rx_errors & tx_dropped are u32, updated
489 			 * without syncp protection.
490 			 */
491 			rx_errors	+= p->rx_errors;
492 			tx_dropped	+= p->tx_dropped;
493 		}
494 		stats->rx_errors	= rx_errors;
495 		stats->rx_dropped	= rx_errors;
496 		stats->tx_dropped	= tx_dropped;
497 	}
498 	return stats;
499 }
500 
501 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
502 					struct ethtool_drvinfo *drvinfo)
503 {
504 	snprintf(drvinfo->driver, 32, "macvlan");
505 	snprintf(drvinfo->version, 32, "0.1");
506 }
507 
508 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
509 {
510 	const struct macvlan_dev *vlan = netdev_priv(dev);
511 	return dev_ethtool_get_rx_csum(vlan->lowerdev);
512 }
513 
514 static int macvlan_ethtool_get_settings(struct net_device *dev,
515 					struct ethtool_cmd *cmd)
516 {
517 	const struct macvlan_dev *vlan = netdev_priv(dev);
518 	return dev_ethtool_get_settings(vlan->lowerdev, cmd);
519 }
520 
521 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
522 {
523 	const struct macvlan_dev *vlan = netdev_priv(dev);
524 	return dev_ethtool_get_flags(vlan->lowerdev);
525 }
526 
527 static const struct ethtool_ops macvlan_ethtool_ops = {
528 	.get_link		= ethtool_op_get_link,
529 	.get_settings		= macvlan_ethtool_get_settings,
530 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
531 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
532 	.get_flags		= macvlan_ethtool_get_flags,
533 };
534 
535 static const struct net_device_ops macvlan_netdev_ops = {
536 	.ndo_init		= macvlan_init,
537 	.ndo_uninit		= macvlan_uninit,
538 	.ndo_open		= macvlan_open,
539 	.ndo_stop		= macvlan_stop,
540 	.ndo_start_xmit		= macvlan_start_xmit,
541 	.ndo_change_mtu		= macvlan_change_mtu,
542 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
543 	.ndo_set_mac_address	= macvlan_set_mac_address,
544 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
545 	.ndo_get_stats64	= macvlan_dev_get_stats64,
546 	.ndo_validate_addr	= eth_validate_addr,
547 };
548 
549 void macvlan_common_setup(struct net_device *dev)
550 {
551 	ether_setup(dev);
552 
553 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
554 	dev->netdev_ops		= &macvlan_netdev_ops;
555 	dev->destructor		= free_netdev;
556 	dev->header_ops		= &macvlan_hard_header_ops,
557 	dev->ethtool_ops	= &macvlan_ethtool_ops;
558 }
559 EXPORT_SYMBOL_GPL(macvlan_common_setup);
560 
561 static void macvlan_setup(struct net_device *dev)
562 {
563 	macvlan_common_setup(dev);
564 	dev->tx_queue_len	= 0;
565 }
566 
567 static int macvlan_port_create(struct net_device *dev)
568 {
569 	struct macvlan_port *port;
570 	unsigned int i;
571 	int err;
572 
573 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
574 		return -EINVAL;
575 
576 	port = kzalloc(sizeof(*port), GFP_KERNEL);
577 	if (port == NULL)
578 		return -ENOMEM;
579 
580 	port->passthru = false;
581 	port->dev = dev;
582 	INIT_LIST_HEAD(&port->vlans);
583 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
584 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
585 
586 	err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
587 	if (err)
588 		kfree(port);
589 
590 	dev->priv_flags |= IFF_MACVLAN_PORT;
591 	return err;
592 }
593 
594 static void macvlan_port_rcu_free(struct rcu_head *head)
595 {
596 	struct macvlan_port *port;
597 
598 	port = container_of(head, struct macvlan_port, rcu);
599 	kfree(port);
600 }
601 
602 static void macvlan_port_destroy(struct net_device *dev)
603 {
604 	struct macvlan_port *port = macvlan_port_get(dev);
605 
606 	dev->priv_flags &= ~IFF_MACVLAN_PORT;
607 	netdev_rx_handler_unregister(dev);
608 	call_rcu(&port->rcu, macvlan_port_rcu_free);
609 }
610 
611 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
612 {
613 	if (tb[IFLA_ADDRESS]) {
614 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
615 			return -EINVAL;
616 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
617 			return -EADDRNOTAVAIL;
618 	}
619 
620 	if (data && data[IFLA_MACVLAN_MODE]) {
621 		switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
622 		case MACVLAN_MODE_PRIVATE:
623 		case MACVLAN_MODE_VEPA:
624 		case MACVLAN_MODE_BRIDGE:
625 		case MACVLAN_MODE_PASSTHRU:
626 			break;
627 		default:
628 			return -EINVAL;
629 		}
630 	}
631 	return 0;
632 }
633 
634 int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
635 			   struct nlattr *tb[], struct nlattr *data[],
636 			   int (*receive)(struct sk_buff *skb),
637 			   int (*forward)(struct net_device *dev,
638 					  struct sk_buff *skb))
639 {
640 	struct macvlan_dev *vlan = netdev_priv(dev);
641 	struct macvlan_port *port;
642 	struct net_device *lowerdev;
643 	int err;
644 
645 	if (!tb[IFLA_LINK])
646 		return -EINVAL;
647 
648 	lowerdev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
649 	if (lowerdev == NULL)
650 		return -ENODEV;
651 
652 	/* When creating macvlans on top of other macvlans - use
653 	 * the real device as the lowerdev.
654 	 */
655 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
656 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
657 		lowerdev = lowervlan->lowerdev;
658 	}
659 
660 	if (!tb[IFLA_MTU])
661 		dev->mtu = lowerdev->mtu;
662 	else if (dev->mtu > lowerdev->mtu)
663 		return -EINVAL;
664 
665 	if (!tb[IFLA_ADDRESS])
666 		random_ether_addr(dev->dev_addr);
667 
668 	if (!macvlan_port_exists(lowerdev)) {
669 		err = macvlan_port_create(lowerdev);
670 		if (err < 0)
671 			return err;
672 	}
673 	port = macvlan_port_get(lowerdev);
674 
675 	/* Only 1 macvlan device can be created in passthru mode */
676 	if (port->passthru)
677 		return -EINVAL;
678 
679 	vlan->lowerdev = lowerdev;
680 	vlan->dev      = dev;
681 	vlan->port     = port;
682 	vlan->receive  = receive;
683 	vlan->forward  = forward;
684 
685 	vlan->mode     = MACVLAN_MODE_VEPA;
686 	if (data && data[IFLA_MACVLAN_MODE])
687 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
688 
689 	if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
690 		if (!list_empty(&port->vlans))
691 			return -EINVAL;
692 		port->passthru = true;
693 		memcpy(dev->dev_addr, lowerdev->dev_addr, ETH_ALEN);
694 	}
695 
696 	err = register_netdevice(dev);
697 	if (err < 0)
698 		goto destroy_port;
699 
700 	list_add_tail(&vlan->list, &port->vlans);
701 	netif_stacked_transfer_operstate(lowerdev, dev);
702 
703 	return 0;
704 
705 destroy_port:
706 	if (list_empty(&port->vlans))
707 		macvlan_port_destroy(lowerdev);
708 
709 	return err;
710 }
711 EXPORT_SYMBOL_GPL(macvlan_common_newlink);
712 
713 static int macvlan_newlink(struct net *src_net, struct net_device *dev,
714 			   struct nlattr *tb[], struct nlattr *data[])
715 {
716 	return macvlan_common_newlink(src_net, dev, tb, data,
717 				      netif_rx,
718 				      dev_forward_skb);
719 }
720 
721 void macvlan_dellink(struct net_device *dev, struct list_head *head)
722 {
723 	struct macvlan_dev *vlan = netdev_priv(dev);
724 	struct macvlan_port *port = vlan->port;
725 
726 	list_del(&vlan->list);
727 	unregister_netdevice_queue(dev, head);
728 
729 	if (list_empty(&port->vlans))
730 		macvlan_port_destroy(port->dev);
731 }
732 EXPORT_SYMBOL_GPL(macvlan_dellink);
733 
734 static int macvlan_changelink(struct net_device *dev,
735 		struct nlattr *tb[], struct nlattr *data[])
736 {
737 	struct macvlan_dev *vlan = netdev_priv(dev);
738 	if (data && data[IFLA_MACVLAN_MODE])
739 		vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
740 	return 0;
741 }
742 
743 static size_t macvlan_get_size(const struct net_device *dev)
744 {
745 	return nla_total_size(4);
746 }
747 
748 static int macvlan_fill_info(struct sk_buff *skb,
749 				const struct net_device *dev)
750 {
751 	struct macvlan_dev *vlan = netdev_priv(dev);
752 
753 	NLA_PUT_U32(skb, IFLA_MACVLAN_MODE, vlan->mode);
754 	return 0;
755 
756 nla_put_failure:
757 	return -EMSGSIZE;
758 }
759 
760 static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
761 	[IFLA_MACVLAN_MODE] = { .type = NLA_U32 },
762 };
763 
764 int macvlan_link_register(struct rtnl_link_ops *ops)
765 {
766 	/* common fields */
767 	ops->priv_size		= sizeof(struct macvlan_dev);
768 	ops->validate		= macvlan_validate;
769 	ops->maxtype		= IFLA_MACVLAN_MAX;
770 	ops->policy		= macvlan_policy;
771 	ops->changelink		= macvlan_changelink;
772 	ops->get_size		= macvlan_get_size;
773 	ops->fill_info		= macvlan_fill_info;
774 
775 	return rtnl_link_register(ops);
776 };
777 EXPORT_SYMBOL_GPL(macvlan_link_register);
778 
779 static struct rtnl_link_ops macvlan_link_ops = {
780 	.kind		= "macvlan",
781 	.setup		= macvlan_setup,
782 	.newlink	= macvlan_newlink,
783 	.dellink	= macvlan_dellink,
784 };
785 
786 static int macvlan_device_event(struct notifier_block *unused,
787 				unsigned long event, void *ptr)
788 {
789 	struct net_device *dev = ptr;
790 	struct macvlan_dev *vlan, *next;
791 	struct macvlan_port *port;
792 
793 	if (!macvlan_port_exists(dev))
794 		return NOTIFY_DONE;
795 
796 	port = macvlan_port_get(dev);
797 
798 	switch (event) {
799 	case NETDEV_CHANGE:
800 		list_for_each_entry(vlan, &port->vlans, list)
801 			netif_stacked_transfer_operstate(vlan->lowerdev,
802 							 vlan->dev);
803 		break;
804 	case NETDEV_FEAT_CHANGE:
805 		list_for_each_entry(vlan, &port->vlans, list) {
806 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
807 			vlan->dev->gso_max_size = dev->gso_max_size;
808 			netdev_features_change(vlan->dev);
809 		}
810 		break;
811 	case NETDEV_UNREGISTER:
812 		/* twiddle thumbs on netns device moves */
813 		if (dev->reg_state != NETREG_UNREGISTERING)
814 			break;
815 
816 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
817 			vlan->dev->rtnl_link_ops->dellink(vlan->dev, NULL);
818 		break;
819 	case NETDEV_PRE_TYPE_CHANGE:
820 		/* Forbid underlaying device to change its type. */
821 		return NOTIFY_BAD;
822 	}
823 	return NOTIFY_DONE;
824 }
825 
826 static struct notifier_block macvlan_notifier_block __read_mostly = {
827 	.notifier_call	= macvlan_device_event,
828 };
829 
830 static int __init macvlan_init_module(void)
831 {
832 	int err;
833 
834 	register_netdevice_notifier(&macvlan_notifier_block);
835 
836 	err = macvlan_link_register(&macvlan_link_ops);
837 	if (err < 0)
838 		goto err1;
839 	return 0;
840 err1:
841 	unregister_netdevice_notifier(&macvlan_notifier_block);
842 	return err;
843 }
844 
845 static void __exit macvlan_cleanup_module(void)
846 {
847 	rtnl_link_unregister(&macvlan_link_ops);
848 	unregister_netdevice_notifier(&macvlan_notifier_block);
849 }
850 
851 module_init(macvlan_init_module);
852 module_exit(macvlan_cleanup_module);
853 
854 MODULE_LICENSE("GPL");
855 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
856 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
857 MODULE_ALIAS_RTNL_LINK("macvlan");
858