xref: /linux/drivers/net/macvlan.c (revision 185000fc556372b7fb7f26516c325f212030dbd3)
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 
33 #define MACVLAN_HASH_SIZE	(1 << BITS_PER_BYTE)
34 
35 struct macvlan_port {
36 	struct net_device	*dev;
37 	struct hlist_head	vlan_hash[MACVLAN_HASH_SIZE];
38 	struct list_head	vlans;
39 };
40 
41 struct macvlan_dev {
42 	struct net_device	*dev;
43 	struct list_head	list;
44 	struct hlist_node	hlist;
45 	struct macvlan_port	*port;
46 	struct net_device	*lowerdev;
47 };
48 
49 
50 static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
51 					       const unsigned char *addr)
52 {
53 	struct macvlan_dev *vlan;
54 	struct hlist_node *n;
55 
56 	hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[addr[5]], hlist) {
57 		if (!compare_ether_addr(vlan->dev->dev_addr, addr))
58 			return vlan;
59 	}
60 	return NULL;
61 }
62 
63 static void macvlan_broadcast(struct sk_buff *skb,
64 			      const struct macvlan_port *port)
65 {
66 	const struct ethhdr *eth = eth_hdr(skb);
67 	const struct macvlan_dev *vlan;
68 	struct hlist_node *n;
69 	struct net_device *dev;
70 	struct sk_buff *nskb;
71 	unsigned int i;
72 
73 	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
74 		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
75 			dev = vlan->dev;
76 
77 			nskb = skb_clone(skb, GFP_ATOMIC);
78 			if (nskb == NULL) {
79 				dev->stats.rx_errors++;
80 				dev->stats.rx_dropped++;
81 				continue;
82 			}
83 
84 			dev->stats.rx_bytes += skb->len + ETH_HLEN;
85 			dev->stats.rx_packets++;
86 			dev->stats.multicast++;
87 			dev->last_rx = jiffies;
88 
89 			nskb->dev = dev;
90 			if (!compare_ether_addr(eth->h_dest, dev->broadcast))
91 				nskb->pkt_type = PACKET_BROADCAST;
92 			else
93 				nskb->pkt_type = PACKET_MULTICAST;
94 
95 			netif_rx(nskb);
96 		}
97 	}
98 }
99 
100 /* called under rcu_read_lock() from netif_receive_skb */
101 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
102 {
103 	const struct ethhdr *eth = eth_hdr(skb);
104 	const struct macvlan_port *port;
105 	const struct macvlan_dev *vlan;
106 	struct net_device *dev;
107 
108 	port = rcu_dereference(skb->dev->macvlan_port);
109 	if (port == NULL)
110 		return skb;
111 
112 	if (is_multicast_ether_addr(eth->h_dest)) {
113 		macvlan_broadcast(skb, port);
114 		return skb;
115 	}
116 
117 	vlan = macvlan_hash_lookup(port, eth->h_dest);
118 	if (vlan == NULL)
119 		return skb;
120 
121 	dev = vlan->dev;
122 	if (unlikely(!(dev->flags & IFF_UP))) {
123 		kfree_skb(skb);
124 		return NULL;
125 	}
126 
127 	skb = skb_share_check(skb, GFP_ATOMIC);
128 	if (skb == NULL) {
129 		dev->stats.rx_errors++;
130 		dev->stats.rx_dropped++;
131 		return NULL;
132 	}
133 
134 	dev->stats.rx_bytes += skb->len + ETH_HLEN;
135 	dev->stats.rx_packets++;
136 	dev->last_rx = jiffies;
137 
138 	skb->dev = dev;
139 	skb->pkt_type = PACKET_HOST;
140 
141 	netif_rx(skb);
142 	return NULL;
143 }
144 
145 static int macvlan_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
146 {
147 	const struct macvlan_dev *vlan = netdev_priv(dev);
148 	unsigned int len = skb->len;
149 	int ret;
150 
151 	skb->dev = vlan->lowerdev;
152 	ret = dev_queue_xmit(skb);
153 
154 	if (likely(ret == NET_XMIT_SUCCESS)) {
155 		dev->stats.tx_packets++;
156 		dev->stats.tx_bytes += len;
157 	} else {
158 		dev->stats.tx_errors++;
159 		dev->stats.tx_aborted_errors++;
160 	}
161 	return NETDEV_TX_OK;
162 }
163 
164 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
165 			       unsigned short type, const void *daddr,
166 			       const void *saddr, unsigned len)
167 {
168 	const struct macvlan_dev *vlan = netdev_priv(dev);
169 	struct net_device *lowerdev = vlan->lowerdev;
170 
171 	return dev_hard_header(skb, lowerdev, type, daddr,
172 			       saddr ? : dev->dev_addr, len);
173 }
174 
175 static const struct header_ops macvlan_hard_header_ops = {
176 	.create  	= macvlan_hard_header,
177 	.rebuild	= eth_rebuild_header,
178 	.parse		= eth_header_parse,
179 	.cache		= eth_header_cache,
180 	.cache_update	= eth_header_cache_update,
181 };
182 
183 static int macvlan_open(struct net_device *dev)
184 {
185 	struct macvlan_dev *vlan = netdev_priv(dev);
186 	struct macvlan_port *port = vlan->port;
187 	struct net_device *lowerdev = vlan->lowerdev;
188 	int err;
189 
190 	err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
191 	if (err < 0)
192 		goto out;
193 	if (dev->flags & IFF_ALLMULTI) {
194 		err = dev_set_allmulti(lowerdev, 1);
195 		if (err < 0)
196 			goto del_unicast;
197 	}
198 
199 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
200 	return 0;
201 
202 del_unicast:
203 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
204 out:
205 	return err;
206 }
207 
208 static int macvlan_stop(struct net_device *dev)
209 {
210 	struct macvlan_dev *vlan = netdev_priv(dev);
211 	struct net_device *lowerdev = vlan->lowerdev;
212 
213 	dev_mc_unsync(lowerdev, dev);
214 	if (dev->flags & IFF_ALLMULTI)
215 		dev_set_allmulti(lowerdev, -1);
216 
217 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
218 
219 	hlist_del_rcu(&vlan->hlist);
220 	synchronize_rcu();
221 	return 0;
222 }
223 
224 static int macvlan_set_mac_address(struct net_device *dev, void *p)
225 {
226 	struct macvlan_dev *vlan = netdev_priv(dev);
227 	struct net_device *lowerdev = vlan->lowerdev;
228 	struct sockaddr *addr = p;
229 	int err;
230 
231 	if (!is_valid_ether_addr(addr->sa_data))
232 		return -EADDRNOTAVAIL;
233 
234 	if (!(dev->flags & IFF_UP))
235 		goto out;
236 
237 	err = dev_unicast_add(lowerdev, addr->sa_data, ETH_ALEN);
238 	if (err < 0)
239 		return err;
240 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
241 
242 out:
243 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
244 	return 0;
245 }
246 
247 static void macvlan_change_rx_flags(struct net_device *dev, int change)
248 {
249 	struct macvlan_dev *vlan = netdev_priv(dev);
250 	struct net_device *lowerdev = vlan->lowerdev;
251 
252 	if (change & IFF_ALLMULTI)
253 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
254 }
255 
256 static void macvlan_set_multicast_list(struct net_device *dev)
257 {
258 	struct macvlan_dev *vlan = netdev_priv(dev);
259 
260 	dev_mc_sync(vlan->lowerdev, dev);
261 }
262 
263 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
264 {
265 	struct macvlan_dev *vlan = netdev_priv(dev);
266 
267 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
268 		return -EINVAL;
269 	dev->mtu = new_mtu;
270 	return 0;
271 }
272 
273 /*
274  * macvlan network devices have devices nesting below it and are a special
275  * "super class" of normal network devices; split their locks off into a
276  * separate class since they always nest.
277  */
278 static struct lock_class_key macvlan_netdev_xmit_lock_key;
279 
280 #define MACVLAN_FEATURES \
281 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
282 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
283 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
284 
285 #define MACVLAN_STATE_MASK \
286 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
287 
288 static void macvlan_set_lockdep_class_one(struct net_device *dev,
289 					  struct netdev_queue *txq,
290 					  void *_unused)
291 {
292 	lockdep_set_class(&txq->_xmit_lock,
293 			  &macvlan_netdev_xmit_lock_key);
294 }
295 
296 static void macvlan_set_lockdep_class(struct net_device *dev)
297 {
298 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
299 }
300 
301 static int macvlan_init(struct net_device *dev)
302 {
303 	struct macvlan_dev *vlan = netdev_priv(dev);
304 	const struct net_device *lowerdev = vlan->lowerdev;
305 
306 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
307 				  (lowerdev->state & MACVLAN_STATE_MASK);
308 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
309 	dev->iflink		= lowerdev->ifindex;
310 
311 	macvlan_set_lockdep_class(dev);
312 
313 	return 0;
314 }
315 
316 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
317 					struct ethtool_drvinfo *drvinfo)
318 {
319 	snprintf(drvinfo->driver, 32, "macvlan");
320 	snprintf(drvinfo->version, 32, "0.1");
321 }
322 
323 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
324 {
325 	const struct macvlan_dev *vlan = netdev_priv(dev);
326 	struct net_device *lowerdev = vlan->lowerdev;
327 
328 	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
329 		return 0;
330 	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
331 }
332 
333 static const struct ethtool_ops macvlan_ethtool_ops = {
334 	.get_link		= ethtool_op_get_link,
335 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
336 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
337 };
338 
339 static void macvlan_setup(struct net_device *dev)
340 {
341 	ether_setup(dev);
342 
343 	dev->init		= macvlan_init;
344 	dev->open		= macvlan_open;
345 	dev->stop		= macvlan_stop;
346 	dev->change_mtu		= macvlan_change_mtu;
347 	dev->change_rx_flags	= macvlan_change_rx_flags;
348 	dev->set_mac_address	= macvlan_set_mac_address;
349 	dev->set_multicast_list	= macvlan_set_multicast_list;
350 	dev->hard_start_xmit	= macvlan_hard_start_xmit;
351 	dev->destructor		= free_netdev;
352 	dev->header_ops		= &macvlan_hard_header_ops,
353 	dev->ethtool_ops	= &macvlan_ethtool_ops;
354 	dev->tx_queue_len	= 0;
355 }
356 
357 static int macvlan_port_create(struct net_device *dev)
358 {
359 	struct macvlan_port *port;
360 	unsigned int i;
361 
362 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
363 		return -EINVAL;
364 
365 	port = kzalloc(sizeof(*port), GFP_KERNEL);
366 	if (port == NULL)
367 		return -ENOMEM;
368 
369 	port->dev = dev;
370 	INIT_LIST_HEAD(&port->vlans);
371 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
372 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
373 	rcu_assign_pointer(dev->macvlan_port, port);
374 	return 0;
375 }
376 
377 static void macvlan_port_destroy(struct net_device *dev)
378 {
379 	struct macvlan_port *port = dev->macvlan_port;
380 
381 	rcu_assign_pointer(dev->macvlan_port, NULL);
382 	synchronize_rcu();
383 	kfree(port);
384 }
385 
386 static void macvlan_transfer_operstate(struct net_device *dev)
387 {
388 	struct macvlan_dev *vlan = netdev_priv(dev);
389 	const struct net_device *lowerdev = vlan->lowerdev;
390 
391 	if (lowerdev->operstate == IF_OPER_DORMANT)
392 		netif_dormant_on(dev);
393 	else
394 		netif_dormant_off(dev);
395 
396 	if (netif_carrier_ok(lowerdev)) {
397 		if (!netif_carrier_ok(dev))
398 			netif_carrier_on(dev);
399 	} else {
400 		if (netif_carrier_ok(dev))
401 			netif_carrier_off(dev);
402 	}
403 }
404 
405 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
406 {
407 	if (tb[IFLA_ADDRESS]) {
408 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
409 			return -EINVAL;
410 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
411 			return -EADDRNOTAVAIL;
412 	}
413 	return 0;
414 }
415 
416 static int macvlan_newlink(struct net_device *dev,
417 			   struct nlattr *tb[], struct nlattr *data[])
418 {
419 	struct macvlan_dev *vlan = netdev_priv(dev);
420 	struct macvlan_port *port;
421 	struct net_device *lowerdev;
422 	int err;
423 
424 	if (!tb[IFLA_LINK])
425 		return -EINVAL;
426 
427 	lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
428 	if (lowerdev == NULL)
429 		return -ENODEV;
430 
431 	/* Don't allow macvlans on top of other macvlans - its not really
432 	 * wrong, but lockdep can't handle it and its not useful for anything
433 	 * you couldn't do directly on top of the real device.
434 	 */
435 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops)
436 		return -ENODEV;
437 
438 	if (!tb[IFLA_MTU])
439 		dev->mtu = lowerdev->mtu;
440 	else if (dev->mtu > lowerdev->mtu)
441 		return -EINVAL;
442 
443 	if (!tb[IFLA_ADDRESS])
444 		random_ether_addr(dev->dev_addr);
445 
446 	if (lowerdev->macvlan_port == NULL) {
447 		err = macvlan_port_create(lowerdev);
448 		if (err < 0)
449 			return err;
450 	}
451 	port = lowerdev->macvlan_port;
452 
453 	vlan->lowerdev = lowerdev;
454 	vlan->dev      = dev;
455 	vlan->port     = port;
456 
457 	err = register_netdevice(dev);
458 	if (err < 0)
459 		return err;
460 
461 	list_add_tail(&vlan->list, &port->vlans);
462 	macvlan_transfer_operstate(dev);
463 	return 0;
464 }
465 
466 static void macvlan_dellink(struct net_device *dev)
467 {
468 	struct macvlan_dev *vlan = netdev_priv(dev);
469 	struct macvlan_port *port = vlan->port;
470 
471 	list_del(&vlan->list);
472 	unregister_netdevice(dev);
473 
474 	if (list_empty(&port->vlans))
475 		macvlan_port_destroy(port->dev);
476 }
477 
478 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
479 	.kind		= "macvlan",
480 	.priv_size	= sizeof(struct macvlan_dev),
481 	.setup		= macvlan_setup,
482 	.validate	= macvlan_validate,
483 	.newlink	= macvlan_newlink,
484 	.dellink	= macvlan_dellink,
485 };
486 
487 static int macvlan_device_event(struct notifier_block *unused,
488 				unsigned long event, void *ptr)
489 {
490 	struct net_device *dev = ptr;
491 	struct macvlan_dev *vlan, *next;
492 	struct macvlan_port *port;
493 
494 	port = dev->macvlan_port;
495 	if (port == NULL)
496 		return NOTIFY_DONE;
497 
498 	switch (event) {
499 	case NETDEV_CHANGE:
500 		list_for_each_entry(vlan, &port->vlans, list)
501 			macvlan_transfer_operstate(vlan->dev);
502 		break;
503 	case NETDEV_FEAT_CHANGE:
504 		list_for_each_entry(vlan, &port->vlans, list) {
505 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
506 			netdev_features_change(vlan->dev);
507 		}
508 		break;
509 	case NETDEV_UNREGISTER:
510 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
511 			macvlan_dellink(vlan->dev);
512 		break;
513 	}
514 	return NOTIFY_DONE;
515 }
516 
517 static struct notifier_block macvlan_notifier_block __read_mostly = {
518 	.notifier_call	= macvlan_device_event,
519 };
520 
521 static int __init macvlan_init_module(void)
522 {
523 	int err;
524 
525 	register_netdevice_notifier(&macvlan_notifier_block);
526 	macvlan_handle_frame_hook = macvlan_handle_frame;
527 
528 	err = rtnl_link_register(&macvlan_link_ops);
529 	if (err < 0)
530 		goto err1;
531 	return 0;
532 err1:
533 	macvlan_handle_frame_hook = NULL;
534 	unregister_netdevice_notifier(&macvlan_notifier_block);
535 	return err;
536 }
537 
538 static void __exit macvlan_cleanup_module(void)
539 {
540 	rtnl_link_unregister(&macvlan_link_ops);
541 	macvlan_handle_frame_hook = NULL;
542 	unregister_netdevice_notifier(&macvlan_notifier_block);
543 }
544 
545 module_init(macvlan_init_module);
546 module_exit(macvlan_cleanup_module);
547 
548 MODULE_LICENSE("GPL");
549 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
550 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
551 MODULE_ALIAS_RTNL_LINK("macvlan");
552