xref: /linux/drivers/net/macvlan.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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);
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);
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);
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 		err = dev_unicast_add(lowerdev, addr->sa_data);
286 		if (err)
287 			return err;
288 
289 		dev_unicast_delete(lowerdev, dev->dev_addr);
290 
291 		macvlan_hash_change_addr(vlan, addr->sa_data);
292 	}
293 	return 0;
294 }
295 
296 static void macvlan_change_rx_flags(struct net_device *dev, int change)
297 {
298 	struct macvlan_dev *vlan = netdev_priv(dev);
299 	struct net_device *lowerdev = vlan->lowerdev;
300 
301 	if (change & IFF_ALLMULTI)
302 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
303 }
304 
305 static void macvlan_set_multicast_list(struct net_device *dev)
306 {
307 	struct macvlan_dev *vlan = netdev_priv(dev);
308 
309 	dev_mc_sync(vlan->lowerdev, dev);
310 }
311 
312 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
313 {
314 	struct macvlan_dev *vlan = netdev_priv(dev);
315 
316 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
317 		return -EINVAL;
318 	dev->mtu = new_mtu;
319 	return 0;
320 }
321 
322 /*
323  * macvlan network devices have devices nesting below it and are a special
324  * "super class" of normal network devices; split their locks off into a
325  * separate class since they always nest.
326  */
327 static struct lock_class_key macvlan_netdev_xmit_lock_key;
328 static struct lock_class_key macvlan_netdev_addr_lock_key;
329 
330 #define MACVLAN_FEATURES \
331 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
332 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
333 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
334 
335 #define MACVLAN_STATE_MASK \
336 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
337 
338 static void macvlan_set_lockdep_class_one(struct net_device *dev,
339 					  struct netdev_queue *txq,
340 					  void *_unused)
341 {
342 	lockdep_set_class(&txq->_xmit_lock,
343 			  &macvlan_netdev_xmit_lock_key);
344 }
345 
346 static void macvlan_set_lockdep_class(struct net_device *dev)
347 {
348 	lockdep_set_class(&dev->addr_list_lock,
349 			  &macvlan_netdev_addr_lock_key);
350 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
351 }
352 
353 static int macvlan_init(struct net_device *dev)
354 {
355 	struct macvlan_dev *vlan = netdev_priv(dev);
356 	const struct net_device *lowerdev = vlan->lowerdev;
357 
358 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
359 				  (lowerdev->state & MACVLAN_STATE_MASK);
360 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
361 	dev->iflink		= lowerdev->ifindex;
362 	dev->hard_header_len	= lowerdev->hard_header_len;
363 
364 	macvlan_set_lockdep_class(dev);
365 
366 	return 0;
367 }
368 
369 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
370 					struct ethtool_drvinfo *drvinfo)
371 {
372 	snprintf(drvinfo->driver, 32, "macvlan");
373 	snprintf(drvinfo->version, 32, "0.1");
374 }
375 
376 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
377 {
378 	const struct macvlan_dev *vlan = netdev_priv(dev);
379 	return dev_ethtool_get_rx_csum(vlan->lowerdev);
380 }
381 
382 static int macvlan_ethtool_get_settings(struct net_device *dev,
383 					struct ethtool_cmd *cmd)
384 {
385 	const struct macvlan_dev *vlan = netdev_priv(dev);
386 	return dev_ethtool_get_settings(vlan->lowerdev, cmd);
387 }
388 
389 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
390 {
391 	const struct macvlan_dev *vlan = netdev_priv(dev);
392 	return dev_ethtool_get_flags(vlan->lowerdev);
393 }
394 
395 static const struct ethtool_ops macvlan_ethtool_ops = {
396 	.get_link		= ethtool_op_get_link,
397 	.get_settings		= macvlan_ethtool_get_settings,
398 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
399 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
400 	.get_flags		= macvlan_ethtool_get_flags,
401 };
402 
403 static const struct net_device_ops macvlan_netdev_ops = {
404 	.ndo_init		= macvlan_init,
405 	.ndo_open		= macvlan_open,
406 	.ndo_stop		= macvlan_stop,
407 	.ndo_start_xmit		= macvlan_start_xmit,
408 	.ndo_change_mtu		= macvlan_change_mtu,
409 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
410 	.ndo_set_mac_address	= macvlan_set_mac_address,
411 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
412 	.ndo_validate_addr	= eth_validate_addr,
413 };
414 
415 static void macvlan_setup(struct net_device *dev)
416 {
417 	ether_setup(dev);
418 
419 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
420 	dev->netdev_ops		= &macvlan_netdev_ops;
421 	dev->destructor		= free_netdev;
422 	dev->header_ops		= &macvlan_hard_header_ops,
423 	dev->ethtool_ops	= &macvlan_ethtool_ops;
424 	dev->tx_queue_len	= 0;
425 }
426 
427 static int macvlan_port_create(struct net_device *dev)
428 {
429 	struct macvlan_port *port;
430 	unsigned int i;
431 
432 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
433 		return -EINVAL;
434 
435 	port = kzalloc(sizeof(*port), GFP_KERNEL);
436 	if (port == NULL)
437 		return -ENOMEM;
438 
439 	port->dev = dev;
440 	INIT_LIST_HEAD(&port->vlans);
441 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
442 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
443 	rcu_assign_pointer(dev->macvlan_port, port);
444 	return 0;
445 }
446 
447 static void macvlan_port_destroy(struct net_device *dev)
448 {
449 	struct macvlan_port *port = dev->macvlan_port;
450 
451 	rcu_assign_pointer(dev->macvlan_port, NULL);
452 	synchronize_rcu();
453 	kfree(port);
454 }
455 
456 static void macvlan_transfer_operstate(struct net_device *dev)
457 {
458 	struct macvlan_dev *vlan = netdev_priv(dev);
459 	const struct net_device *lowerdev = vlan->lowerdev;
460 
461 	if (lowerdev->operstate == IF_OPER_DORMANT)
462 		netif_dormant_on(dev);
463 	else
464 		netif_dormant_off(dev);
465 
466 	if (netif_carrier_ok(lowerdev)) {
467 		if (!netif_carrier_ok(dev))
468 			netif_carrier_on(dev);
469 	} else {
470 		if (netif_carrier_ok(dev))
471 			netif_carrier_off(dev);
472 	}
473 }
474 
475 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
476 {
477 	if (tb[IFLA_ADDRESS]) {
478 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
479 			return -EINVAL;
480 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
481 			return -EADDRNOTAVAIL;
482 	}
483 	return 0;
484 }
485 
486 static int macvlan_newlink(struct net_device *dev,
487 			   struct nlattr *tb[], struct nlattr *data[])
488 {
489 	struct macvlan_dev *vlan = netdev_priv(dev);
490 	struct macvlan_port *port;
491 	struct net_device *lowerdev;
492 	int err;
493 
494 	if (!tb[IFLA_LINK])
495 		return -EINVAL;
496 
497 	lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
498 	if (lowerdev == NULL)
499 		return -ENODEV;
500 
501 	/* When creating macvlans on top of other macvlans - use
502 	 * the real device as the lowerdev.
503 	 */
504 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
505 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
506 		lowerdev = lowervlan->lowerdev;
507 	}
508 
509 	if (!tb[IFLA_MTU])
510 		dev->mtu = lowerdev->mtu;
511 	else if (dev->mtu > lowerdev->mtu)
512 		return -EINVAL;
513 
514 	if (!tb[IFLA_ADDRESS])
515 		random_ether_addr(dev->dev_addr);
516 
517 	if (lowerdev->macvlan_port == NULL) {
518 		err = macvlan_port_create(lowerdev);
519 		if (err < 0)
520 			return err;
521 	}
522 	port = lowerdev->macvlan_port;
523 
524 	vlan->lowerdev = lowerdev;
525 	vlan->dev      = dev;
526 	vlan->port     = port;
527 
528 	err = register_netdevice(dev);
529 	if (err < 0)
530 		return err;
531 
532 	list_add_tail(&vlan->list, &port->vlans);
533 	macvlan_transfer_operstate(dev);
534 	return 0;
535 }
536 
537 static void macvlan_dellink(struct net_device *dev)
538 {
539 	struct macvlan_dev *vlan = netdev_priv(dev);
540 	struct macvlan_port *port = vlan->port;
541 
542 	list_del(&vlan->list);
543 	unregister_netdevice(dev);
544 
545 	if (list_empty(&port->vlans))
546 		macvlan_port_destroy(port->dev);
547 }
548 
549 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
550 	.kind		= "macvlan",
551 	.priv_size	= sizeof(struct macvlan_dev),
552 	.setup		= macvlan_setup,
553 	.validate	= macvlan_validate,
554 	.newlink	= macvlan_newlink,
555 	.dellink	= macvlan_dellink,
556 };
557 
558 static int macvlan_device_event(struct notifier_block *unused,
559 				unsigned long event, void *ptr)
560 {
561 	struct net_device *dev = ptr;
562 	struct macvlan_dev *vlan, *next;
563 	struct macvlan_port *port;
564 
565 	port = dev->macvlan_port;
566 	if (port == NULL)
567 		return NOTIFY_DONE;
568 
569 	switch (event) {
570 	case NETDEV_CHANGE:
571 		list_for_each_entry(vlan, &port->vlans, list)
572 			macvlan_transfer_operstate(vlan->dev);
573 		break;
574 	case NETDEV_FEAT_CHANGE:
575 		list_for_each_entry(vlan, &port->vlans, list) {
576 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
577 			netdev_features_change(vlan->dev);
578 		}
579 		break;
580 	case NETDEV_UNREGISTER:
581 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
582 			macvlan_dellink(vlan->dev);
583 		break;
584 	}
585 	return NOTIFY_DONE;
586 }
587 
588 static struct notifier_block macvlan_notifier_block __read_mostly = {
589 	.notifier_call	= macvlan_device_event,
590 };
591 
592 static int __init macvlan_init_module(void)
593 {
594 	int err;
595 
596 	register_netdevice_notifier(&macvlan_notifier_block);
597 	macvlan_handle_frame_hook = macvlan_handle_frame;
598 
599 	err = rtnl_link_register(&macvlan_link_ops);
600 	if (err < 0)
601 		goto err1;
602 	return 0;
603 err1:
604 	macvlan_handle_frame_hook = NULL;
605 	unregister_netdevice_notifier(&macvlan_notifier_block);
606 	return err;
607 }
608 
609 static void __exit macvlan_cleanup_module(void)
610 {
611 	rtnl_link_unregister(&macvlan_link_ops);
612 	macvlan_handle_frame_hook = NULL;
613 	unregister_netdevice_notifier(&macvlan_notifier_block);
614 }
615 
616 module_init(macvlan_init_module);
617 module_exit(macvlan_cleanup_module);
618 
619 MODULE_LICENSE("GPL");
620 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
621 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
622 MODULE_ALIAS_RTNL_LINK("macvlan");
623