xref: /linux/drivers/net/macvlan.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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_hash_add(struct macvlan_dev *vlan)
64 {
65 	struct macvlan_port *port = vlan->port;
66 	const unsigned char *addr = vlan->dev->dev_addr;
67 
68 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[addr[5]]);
69 }
70 
71 static void macvlan_hash_del(struct macvlan_dev *vlan)
72 {
73 	hlist_del_rcu(&vlan->hlist);
74 	synchronize_rcu();
75 }
76 
77 static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
78 					const unsigned char *addr)
79 {
80 	macvlan_hash_del(vlan);
81 	/* Now that we are unhashed it is safe to change the device
82 	 * address without confusing packet delivery.
83 	 */
84 	memcpy(vlan->dev->dev_addr, addr, ETH_ALEN);
85 	macvlan_hash_add(vlan);
86 }
87 
88 static int macvlan_addr_busy(const struct macvlan_port *port,
89 				const unsigned char *addr)
90 {
91 	/* Test to see if the specified multicast address is
92 	 * currently in use by the underlying device or
93 	 * another macvlan.
94 	 */
95 	if (memcmp(port->dev->dev_addr, addr, ETH_ALEN) == 0)
96 		return 1;
97 
98 	if (macvlan_hash_lookup(port, addr))
99 		return 1;
100 
101 	return 0;
102 }
103 
104 static void macvlan_broadcast(struct sk_buff *skb,
105 			      const struct macvlan_port *port)
106 {
107 	const struct ethhdr *eth = eth_hdr(skb);
108 	const struct macvlan_dev *vlan;
109 	struct hlist_node *n;
110 	struct net_device *dev;
111 	struct sk_buff *nskb;
112 	unsigned int i;
113 
114 	if (skb->protocol == htons(ETH_P_PAUSE))
115 		return;
116 
117 	for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
118 		hlist_for_each_entry_rcu(vlan, n, &port->vlan_hash[i], hlist) {
119 			dev = vlan->dev;
120 
121 			nskb = skb_clone(skb, GFP_ATOMIC);
122 			if (nskb == NULL) {
123 				dev->stats.rx_errors++;
124 				dev->stats.rx_dropped++;
125 				continue;
126 			}
127 
128 			dev->stats.rx_bytes += skb->len + ETH_HLEN;
129 			dev->stats.rx_packets++;
130 			dev->stats.multicast++;
131 
132 			nskb->dev = dev;
133 			if (!compare_ether_addr(eth->h_dest, dev->broadcast))
134 				nskb->pkt_type = PACKET_BROADCAST;
135 			else
136 				nskb->pkt_type = PACKET_MULTICAST;
137 
138 			netif_rx(nskb);
139 		}
140 	}
141 }
142 
143 /* called under rcu_read_lock() from netif_receive_skb */
144 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
145 {
146 	const struct ethhdr *eth = eth_hdr(skb);
147 	const struct macvlan_port *port;
148 	const struct macvlan_dev *vlan;
149 	struct net_device *dev;
150 
151 	port = rcu_dereference(skb->dev->macvlan_port);
152 	if (port == NULL)
153 		return skb;
154 
155 	if (is_multicast_ether_addr(eth->h_dest)) {
156 		macvlan_broadcast(skb, port);
157 		return skb;
158 	}
159 
160 	vlan = macvlan_hash_lookup(port, eth->h_dest);
161 	if (vlan == NULL)
162 		return skb;
163 
164 	dev = vlan->dev;
165 	if (unlikely(!(dev->flags & IFF_UP))) {
166 		kfree_skb(skb);
167 		return NULL;
168 	}
169 
170 	skb = skb_share_check(skb, GFP_ATOMIC);
171 	if (skb == NULL) {
172 		dev->stats.rx_errors++;
173 		dev->stats.rx_dropped++;
174 		return NULL;
175 	}
176 
177 	dev->stats.rx_bytes += skb->len + ETH_HLEN;
178 	dev->stats.rx_packets++;
179 
180 	skb->dev = dev;
181 	skb->pkt_type = PACKET_HOST;
182 
183 	netif_rx(skb);
184 	return NULL;
185 }
186 
187 static int macvlan_start_xmit(struct sk_buff *skb, struct net_device *dev)
188 {
189 	const struct macvlan_dev *vlan = netdev_priv(dev);
190 	unsigned int len = skb->len;
191 	int ret;
192 
193 	skb->dev = vlan->lowerdev;
194 	ret = dev_queue_xmit(skb);
195 
196 	if (likely(ret == NET_XMIT_SUCCESS)) {
197 		dev->stats.tx_packets++;
198 		dev->stats.tx_bytes += len;
199 	} else {
200 		dev->stats.tx_errors++;
201 		dev->stats.tx_aborted_errors++;
202 	}
203 	return NETDEV_TX_OK;
204 }
205 
206 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
207 			       unsigned short type, const void *daddr,
208 			       const void *saddr, unsigned len)
209 {
210 	const struct macvlan_dev *vlan = netdev_priv(dev);
211 	struct net_device *lowerdev = vlan->lowerdev;
212 
213 	return dev_hard_header(skb, lowerdev, type, daddr,
214 			       saddr ? : dev->dev_addr, len);
215 }
216 
217 static const struct header_ops macvlan_hard_header_ops = {
218 	.create  	= macvlan_hard_header,
219 	.rebuild	= eth_rebuild_header,
220 	.parse		= eth_header_parse,
221 	.cache		= eth_header_cache,
222 	.cache_update	= eth_header_cache_update,
223 };
224 
225 static int macvlan_open(struct net_device *dev)
226 {
227 	struct macvlan_dev *vlan = netdev_priv(dev);
228 	struct net_device *lowerdev = vlan->lowerdev;
229 	int err;
230 
231 	err = -EBUSY;
232 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
233 		goto out;
234 
235 	err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
236 	if (err < 0)
237 		goto out;
238 	if (dev->flags & IFF_ALLMULTI) {
239 		err = dev_set_allmulti(lowerdev, 1);
240 		if (err < 0)
241 			goto del_unicast;
242 	}
243 	macvlan_hash_add(vlan);
244 	return 0;
245 
246 del_unicast:
247 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
248 out:
249 	return err;
250 }
251 
252 static int macvlan_stop(struct net_device *dev)
253 {
254 	struct macvlan_dev *vlan = netdev_priv(dev);
255 	struct net_device *lowerdev = vlan->lowerdev;
256 
257 	dev_mc_unsync(lowerdev, dev);
258 	if (dev->flags & IFF_ALLMULTI)
259 		dev_set_allmulti(lowerdev, -1);
260 
261 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
262 
263 	macvlan_hash_del(vlan);
264 	return 0;
265 }
266 
267 static int macvlan_set_mac_address(struct net_device *dev, void *p)
268 {
269 	struct macvlan_dev *vlan = netdev_priv(dev);
270 	struct net_device *lowerdev = vlan->lowerdev;
271 	struct sockaddr *addr = p;
272 	int err;
273 
274 	if (!is_valid_ether_addr(addr->sa_data))
275 		return -EADDRNOTAVAIL;
276 
277 	if (!(dev->flags & IFF_UP)) {
278 		/* Just copy in the new address */
279 		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
280 	} else {
281 		/* Rehash and update the device filters */
282 		if (macvlan_addr_busy(vlan->port, addr->sa_data))
283 			return -EBUSY;
284 
285 		if ((err = dev_unicast_add(lowerdev, addr->sa_data, ETH_ALEN)))
286 			return err;
287 
288 		dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
289 
290 		macvlan_hash_change_addr(vlan, addr->sa_data);
291 	}
292 	return 0;
293 }
294 
295 static void macvlan_change_rx_flags(struct net_device *dev, int change)
296 {
297 	struct macvlan_dev *vlan = netdev_priv(dev);
298 	struct net_device *lowerdev = vlan->lowerdev;
299 
300 	if (change & IFF_ALLMULTI)
301 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
302 }
303 
304 static void macvlan_set_multicast_list(struct net_device *dev)
305 {
306 	struct macvlan_dev *vlan = netdev_priv(dev);
307 
308 	dev_mc_sync(vlan->lowerdev, dev);
309 }
310 
311 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
312 {
313 	struct macvlan_dev *vlan = netdev_priv(dev);
314 
315 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
316 		return -EINVAL;
317 	dev->mtu = new_mtu;
318 	return 0;
319 }
320 
321 /*
322  * macvlan network devices have devices nesting below it and are a special
323  * "super class" of normal network devices; split their locks off into a
324  * separate class since they always nest.
325  */
326 static struct lock_class_key macvlan_netdev_xmit_lock_key;
327 static struct lock_class_key macvlan_netdev_addr_lock_key;
328 
329 #define MACVLAN_FEATURES \
330 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
331 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
332 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
333 
334 #define MACVLAN_STATE_MASK \
335 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
336 
337 static void macvlan_set_lockdep_class_one(struct net_device *dev,
338 					  struct netdev_queue *txq,
339 					  void *_unused)
340 {
341 	lockdep_set_class(&txq->_xmit_lock,
342 			  &macvlan_netdev_xmit_lock_key);
343 }
344 
345 static void macvlan_set_lockdep_class(struct net_device *dev)
346 {
347 	lockdep_set_class(&dev->addr_list_lock,
348 			  &macvlan_netdev_addr_lock_key);
349 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
350 }
351 
352 static int macvlan_init(struct net_device *dev)
353 {
354 	struct macvlan_dev *vlan = netdev_priv(dev);
355 	const struct net_device *lowerdev = vlan->lowerdev;
356 
357 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
358 				  (lowerdev->state & MACVLAN_STATE_MASK);
359 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
360 	dev->iflink		= lowerdev->ifindex;
361 
362 	macvlan_set_lockdep_class(dev);
363 
364 	return 0;
365 }
366 
367 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
368 					struct ethtool_drvinfo *drvinfo)
369 {
370 	snprintf(drvinfo->driver, 32, "macvlan");
371 	snprintf(drvinfo->version, 32, "0.1");
372 }
373 
374 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
375 {
376 	const struct macvlan_dev *vlan = netdev_priv(dev);
377 	struct net_device *lowerdev = vlan->lowerdev;
378 
379 	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
380 		return 0;
381 	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
382 }
383 
384 static int macvlan_ethtool_get_settings(struct net_device *dev,
385 					struct ethtool_cmd *cmd)
386 {
387 	const struct macvlan_dev *vlan = netdev_priv(dev);
388 	struct net_device *lowerdev = vlan->lowerdev;
389 
390 	if (!lowerdev->ethtool_ops->get_settings)
391 		return -EOPNOTSUPP;
392 
393 	return lowerdev->ethtool_ops->get_settings(lowerdev, cmd);
394 }
395 
396 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
397 {
398 	const struct macvlan_dev *vlan = netdev_priv(dev);
399 	struct net_device *lowerdev = vlan->lowerdev;
400 
401 	if (!lowerdev->ethtool_ops->get_flags)
402 		return 0;
403 	return lowerdev->ethtool_ops->get_flags(lowerdev);
404 }
405 
406 static const struct ethtool_ops macvlan_ethtool_ops = {
407 	.get_link		= ethtool_op_get_link,
408 	.get_settings		= macvlan_ethtool_get_settings,
409 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
410 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
411 	.get_flags		= macvlan_ethtool_get_flags,
412 };
413 
414 static const struct net_device_ops macvlan_netdev_ops = {
415 	.ndo_init		= macvlan_init,
416 	.ndo_open		= macvlan_open,
417 	.ndo_stop		= macvlan_stop,
418 	.ndo_start_xmit		= macvlan_start_xmit,
419 	.ndo_change_mtu		= macvlan_change_mtu,
420 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
421 	.ndo_set_mac_address	= macvlan_set_mac_address,
422 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
423 	.ndo_validate_addr	= eth_validate_addr,
424 };
425 
426 static void macvlan_setup(struct net_device *dev)
427 {
428 	ether_setup(dev);
429 
430 	dev->netdev_ops		= &macvlan_netdev_ops;
431 	dev->destructor		= free_netdev;
432 	dev->header_ops		= &macvlan_hard_header_ops,
433 	dev->ethtool_ops	= &macvlan_ethtool_ops;
434 	dev->tx_queue_len	= 0;
435 }
436 
437 static int macvlan_port_create(struct net_device *dev)
438 {
439 	struct macvlan_port *port;
440 	unsigned int i;
441 
442 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
443 		return -EINVAL;
444 
445 	port = kzalloc(sizeof(*port), GFP_KERNEL);
446 	if (port == NULL)
447 		return -ENOMEM;
448 
449 	port->dev = dev;
450 	INIT_LIST_HEAD(&port->vlans);
451 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
452 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
453 	rcu_assign_pointer(dev->macvlan_port, port);
454 	return 0;
455 }
456 
457 static void macvlan_port_destroy(struct net_device *dev)
458 {
459 	struct macvlan_port *port = dev->macvlan_port;
460 
461 	rcu_assign_pointer(dev->macvlan_port, NULL);
462 	synchronize_rcu();
463 	kfree(port);
464 }
465 
466 static void macvlan_transfer_operstate(struct net_device *dev)
467 {
468 	struct macvlan_dev *vlan = netdev_priv(dev);
469 	const struct net_device *lowerdev = vlan->lowerdev;
470 
471 	if (lowerdev->operstate == IF_OPER_DORMANT)
472 		netif_dormant_on(dev);
473 	else
474 		netif_dormant_off(dev);
475 
476 	if (netif_carrier_ok(lowerdev)) {
477 		if (!netif_carrier_ok(dev))
478 			netif_carrier_on(dev);
479 	} else {
480 		if (netif_carrier_ok(dev))
481 			netif_carrier_off(dev);
482 	}
483 }
484 
485 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
486 {
487 	if (tb[IFLA_ADDRESS]) {
488 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
489 			return -EINVAL;
490 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
491 			return -EADDRNOTAVAIL;
492 	}
493 	return 0;
494 }
495 
496 static int macvlan_newlink(struct net_device *dev,
497 			   struct nlattr *tb[], struct nlattr *data[])
498 {
499 	struct macvlan_dev *vlan = netdev_priv(dev);
500 	struct macvlan_port *port;
501 	struct net_device *lowerdev;
502 	int err;
503 
504 	if (!tb[IFLA_LINK])
505 		return -EINVAL;
506 
507 	lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
508 	if (lowerdev == NULL)
509 		return -ENODEV;
510 
511 	/* When creating macvlans on top of other macvlans - use
512 	 * the real device as the lowerdev.
513 	 */
514 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
515 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
516 		lowerdev = lowervlan->lowerdev;
517 	}
518 
519 	if (!tb[IFLA_MTU])
520 		dev->mtu = lowerdev->mtu;
521 	else if (dev->mtu > lowerdev->mtu)
522 		return -EINVAL;
523 
524 	if (!tb[IFLA_ADDRESS])
525 		random_ether_addr(dev->dev_addr);
526 
527 	if (lowerdev->macvlan_port == NULL) {
528 		err = macvlan_port_create(lowerdev);
529 		if (err < 0)
530 			return err;
531 	}
532 	port = lowerdev->macvlan_port;
533 
534 	vlan->lowerdev = lowerdev;
535 	vlan->dev      = dev;
536 	vlan->port     = port;
537 
538 	err = register_netdevice(dev);
539 	if (err < 0)
540 		return err;
541 
542 	list_add_tail(&vlan->list, &port->vlans);
543 	macvlan_transfer_operstate(dev);
544 	return 0;
545 }
546 
547 static void macvlan_dellink(struct net_device *dev)
548 {
549 	struct macvlan_dev *vlan = netdev_priv(dev);
550 	struct macvlan_port *port = vlan->port;
551 
552 	list_del(&vlan->list);
553 	unregister_netdevice(dev);
554 
555 	if (list_empty(&port->vlans))
556 		macvlan_port_destroy(port->dev);
557 }
558 
559 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
560 	.kind		= "macvlan",
561 	.priv_size	= sizeof(struct macvlan_dev),
562 	.setup		= macvlan_setup,
563 	.validate	= macvlan_validate,
564 	.newlink	= macvlan_newlink,
565 	.dellink	= macvlan_dellink,
566 };
567 
568 static int macvlan_device_event(struct notifier_block *unused,
569 				unsigned long event, void *ptr)
570 {
571 	struct net_device *dev = ptr;
572 	struct macvlan_dev *vlan, *next;
573 	struct macvlan_port *port;
574 
575 	port = dev->macvlan_port;
576 	if (port == NULL)
577 		return NOTIFY_DONE;
578 
579 	switch (event) {
580 	case NETDEV_CHANGE:
581 		list_for_each_entry(vlan, &port->vlans, list)
582 			macvlan_transfer_operstate(vlan->dev);
583 		break;
584 	case NETDEV_FEAT_CHANGE:
585 		list_for_each_entry(vlan, &port->vlans, list) {
586 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
587 			netdev_features_change(vlan->dev);
588 		}
589 		break;
590 	case NETDEV_UNREGISTER:
591 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
592 			macvlan_dellink(vlan->dev);
593 		break;
594 	}
595 	return NOTIFY_DONE;
596 }
597 
598 static struct notifier_block macvlan_notifier_block __read_mostly = {
599 	.notifier_call	= macvlan_device_event,
600 };
601 
602 static int __init macvlan_init_module(void)
603 {
604 	int err;
605 
606 	register_netdevice_notifier(&macvlan_notifier_block);
607 	macvlan_handle_frame_hook = macvlan_handle_frame;
608 
609 	err = rtnl_link_register(&macvlan_link_ops);
610 	if (err < 0)
611 		goto err1;
612 	return 0;
613 err1:
614 	macvlan_handle_frame_hook = NULL;
615 	unregister_netdevice_notifier(&macvlan_notifier_block);
616 	return err;
617 }
618 
619 static void __exit macvlan_cleanup_module(void)
620 {
621 	rtnl_link_unregister(&macvlan_link_ops);
622 	macvlan_handle_frame_hook = NULL;
623 	unregister_netdevice_notifier(&macvlan_notifier_block);
624 }
625 
626 module_init(macvlan_init_module);
627 module_exit(macvlan_cleanup_module);
628 
629 MODULE_LICENSE("GPL");
630 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
631 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
632 MODULE_ALIAS_RTNL_LINK("macvlan");
633