xref: /linux/drivers/net/macvlan.c (revision 2b8232ce512105e28453f301d1510de8363bccd1)
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/list.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 			if (unlikely(!(dev->flags & IFF_UP)))
77 				continue;
78 
79 			nskb = skb_clone(skb, GFP_ATOMIC);
80 			if (nskb == NULL) {
81 				dev->stats.rx_errors++;
82 				dev->stats.rx_dropped++;
83 				continue;
84 			}
85 
86 			dev->stats.rx_bytes += skb->len + ETH_HLEN;
87 			dev->stats.rx_packets++;
88 			dev->stats.multicast++;
89 			dev->last_rx = jiffies;
90 
91 			nskb->dev = dev;
92 			if (!compare_ether_addr(eth->h_dest, dev->broadcast))
93 				nskb->pkt_type = PACKET_BROADCAST;
94 			else
95 				nskb->pkt_type = PACKET_MULTICAST;
96 
97 			netif_rx(nskb);
98 		}
99 	}
100 }
101 
102 /* called under rcu_read_lock() from netif_receive_skb */
103 static struct sk_buff *macvlan_handle_frame(struct sk_buff *skb)
104 {
105 	const struct ethhdr *eth = eth_hdr(skb);
106 	const struct macvlan_port *port;
107 	const struct macvlan_dev *vlan;
108 	struct net_device *dev;
109 
110 	port = rcu_dereference(skb->dev->macvlan_port);
111 	if (port == NULL)
112 		return skb;
113 
114 	if (is_multicast_ether_addr(eth->h_dest)) {
115 		macvlan_broadcast(skb, port);
116 		return skb;
117 	}
118 
119 	vlan = macvlan_hash_lookup(port, eth->h_dest);
120 	if (vlan == NULL)
121 		return skb;
122 
123 	dev = vlan->dev;
124 	if (unlikely(!(dev->flags & IFF_UP))) {
125 		kfree_skb(skb);
126 		return NULL;
127 	}
128 
129 	skb = skb_share_check(skb, GFP_ATOMIC);
130 	if (skb == NULL) {
131 		dev->stats.rx_errors++;
132 		dev->stats.rx_dropped++;
133 		return NULL;
134 	}
135 
136 	dev->stats.rx_bytes += skb->len + ETH_HLEN;
137 	dev->stats.rx_packets++;
138 	dev->last_rx = jiffies;
139 
140 	skb->dev = dev;
141 	skb->pkt_type = PACKET_HOST;
142 
143 	netif_rx(skb);
144 	return NULL;
145 }
146 
147 static int macvlan_hard_start_xmit(struct sk_buff *skb, struct net_device *dev)
148 {
149 	const struct macvlan_dev *vlan = netdev_priv(dev);
150 	unsigned int len = skb->len;
151 	int ret;
152 
153 	skb->dev = vlan->lowerdev;
154 	ret = dev_queue_xmit(skb);
155 
156 	if (likely(ret == NET_XMIT_SUCCESS)) {
157 		dev->stats.tx_packets++;
158 		dev->stats.tx_bytes += len;
159 	} else {
160 		dev->stats.tx_errors++;
161 		dev->stats.tx_aborted_errors++;
162 	}
163 	return NETDEV_TX_OK;
164 }
165 
166 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
167 			       unsigned short type, const void *daddr,
168 			       const void *saddr, unsigned len)
169 {
170 	const struct macvlan_dev *vlan = netdev_priv(dev);
171 	struct net_device *lowerdev = vlan->lowerdev;
172 
173 	return dev_hard_header(skb, lowerdev, type, daddr,
174 			       saddr ? : dev->dev_addr, len);
175 }
176 
177 static const struct header_ops macvlan_hard_header_ops = {
178 	.create  	= macvlan_hard_header,
179 	.rebuild	= eth_rebuild_header,
180 	.parse		= eth_header_parse,
181 	.rebuild	= eth_rebuild_header,
182 	.cache		= eth_header_cache,
183 	.cache_update	= eth_header_cache_update,
184 };
185 
186 static int macvlan_open(struct net_device *dev)
187 {
188 	struct macvlan_dev *vlan = netdev_priv(dev);
189 	struct macvlan_port *port = vlan->port;
190 	struct net_device *lowerdev = vlan->lowerdev;
191 	int err;
192 
193 	err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
194 	if (err < 0)
195 		return err;
196 	if (dev->flags & IFF_ALLMULTI)
197 		dev_set_allmulti(lowerdev, 1);
198 
199 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
200 	return 0;
201 }
202 
203 static int macvlan_stop(struct net_device *dev)
204 {
205 	struct macvlan_dev *vlan = netdev_priv(dev);
206 	struct net_device *lowerdev = vlan->lowerdev;
207 
208 	dev_mc_unsync(lowerdev, dev);
209 	if (dev->flags & IFF_ALLMULTI)
210 		dev_set_allmulti(lowerdev, -1);
211 
212 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
213 
214 	hlist_del_rcu(&vlan->hlist);
215 	synchronize_rcu();
216 	return 0;
217 }
218 
219 static void macvlan_change_rx_flags(struct net_device *dev, int change)
220 {
221 	struct macvlan_dev *vlan = netdev_priv(dev);
222 	struct net_device *lowerdev = vlan->lowerdev;
223 
224 	if (change & IFF_ALLMULTI)
225 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
226 }
227 
228 static void macvlan_set_multicast_list(struct net_device *dev)
229 {
230 	struct macvlan_dev *vlan = netdev_priv(dev);
231 
232 	dev_mc_sync(vlan->lowerdev, dev);
233 }
234 
235 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
236 {
237 	struct macvlan_dev *vlan = netdev_priv(dev);
238 
239 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
240 		return -EINVAL;
241 	dev->mtu = new_mtu;
242 	return 0;
243 }
244 
245 /*
246  * macvlan network devices have devices nesting below it and are a special
247  * "super class" of normal network devices; split their locks off into a
248  * separate class since they always nest.
249  */
250 static struct lock_class_key macvlan_netdev_xmit_lock_key;
251 
252 #define MACVLAN_FEATURES \
253 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
254 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
255 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
256 
257 #define MACVLAN_STATE_MASK \
258 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
259 
260 static int macvlan_init(struct net_device *dev)
261 {
262 	struct macvlan_dev *vlan = netdev_priv(dev);
263 	const struct net_device *lowerdev = vlan->lowerdev;
264 
265 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
266 				  (lowerdev->state & MACVLAN_STATE_MASK);
267 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
268 	dev->iflink		= lowerdev->ifindex;
269 
270 	lockdep_set_class(&dev->_xmit_lock, &macvlan_netdev_xmit_lock_key);
271 	return 0;
272 }
273 
274 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
275 					struct ethtool_drvinfo *drvinfo)
276 {
277 	snprintf(drvinfo->driver, 32, "macvlan");
278 	snprintf(drvinfo->version, 32, "0.1");
279 }
280 
281 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
282 {
283 	const struct macvlan_dev *vlan = netdev_priv(dev);
284 	struct net_device *lowerdev = vlan->lowerdev;
285 
286 	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
287 		return 0;
288 	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
289 }
290 
291 static const struct ethtool_ops macvlan_ethtool_ops = {
292 	.get_link		= ethtool_op_get_link,
293 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
294 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
295 };
296 
297 static void macvlan_setup(struct net_device *dev)
298 {
299 	ether_setup(dev);
300 
301 	dev->init		= macvlan_init;
302 	dev->open		= macvlan_open;
303 	dev->stop		= macvlan_stop;
304 	dev->change_mtu		= macvlan_change_mtu;
305 	dev->change_rx_flags	= macvlan_change_rx_flags;
306 	dev->set_multicast_list	= macvlan_set_multicast_list;
307 	dev->hard_start_xmit	= macvlan_hard_start_xmit;
308 	dev->destructor		= free_netdev;
309 	dev->header_ops		= &macvlan_hard_header_ops,
310 	dev->ethtool_ops	= &macvlan_ethtool_ops;
311 	dev->tx_queue_len	= 0;
312 }
313 
314 static int macvlan_port_create(struct net_device *dev)
315 {
316 	struct macvlan_port *port;
317 	unsigned int i;
318 
319 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
320 		return -EINVAL;
321 
322 	port = kzalloc(sizeof(*port), GFP_KERNEL);
323 	if (port == NULL)
324 		return -ENOMEM;
325 
326 	port->dev = dev;
327 	INIT_LIST_HEAD(&port->vlans);
328 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
329 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
330 	rcu_assign_pointer(dev->macvlan_port, port);
331 	return 0;
332 }
333 
334 static void macvlan_port_destroy(struct net_device *dev)
335 {
336 	struct macvlan_port *port = dev->macvlan_port;
337 
338 	rcu_assign_pointer(dev->macvlan_port, NULL);
339 	synchronize_rcu();
340 	kfree(port);
341 }
342 
343 static void macvlan_transfer_operstate(struct net_device *dev)
344 {
345 	struct macvlan_dev *vlan = netdev_priv(dev);
346 	const struct net_device *lowerdev = vlan->lowerdev;
347 
348 	if (lowerdev->operstate == IF_OPER_DORMANT)
349 		netif_dormant_on(dev);
350 	else
351 		netif_dormant_off(dev);
352 
353 	if (netif_carrier_ok(lowerdev)) {
354 		if (!netif_carrier_ok(dev))
355 			netif_carrier_on(dev);
356 	} else {
357 		if (netif_carrier_ok(lowerdev))
358 			netif_carrier_off(dev);
359 	}
360 }
361 
362 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
363 {
364 	if (tb[IFLA_ADDRESS]) {
365 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
366 			return -EINVAL;
367 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
368 			return -EADDRNOTAVAIL;
369 	}
370 	return 0;
371 }
372 
373 static int macvlan_newlink(struct net_device *dev,
374 			   struct nlattr *tb[], struct nlattr *data[])
375 {
376 	struct macvlan_dev *vlan = netdev_priv(dev);
377 	struct macvlan_port *port;
378 	struct net_device *lowerdev;
379 	int err;
380 
381 	if (!tb[IFLA_LINK])
382 		return -EINVAL;
383 
384 	lowerdev = __dev_get_by_index(dev->nd_net, nla_get_u32(tb[IFLA_LINK]));
385 	if (lowerdev == NULL)
386 		return -ENODEV;
387 
388 	if (!tb[IFLA_MTU])
389 		dev->mtu = lowerdev->mtu;
390 	else if (dev->mtu > lowerdev->mtu)
391 		return -EINVAL;
392 
393 	if (!tb[IFLA_ADDRESS])
394 		random_ether_addr(dev->dev_addr);
395 
396 	if (lowerdev->macvlan_port == NULL) {
397 		err = macvlan_port_create(lowerdev);
398 		if (err < 0)
399 			return err;
400 	}
401 	port = lowerdev->macvlan_port;
402 
403 	vlan->lowerdev = lowerdev;
404 	vlan->dev      = dev;
405 	vlan->port     = port;
406 
407 	err = register_netdevice(dev);
408 	if (err < 0)
409 		return err;
410 
411 	list_add_tail(&vlan->list, &port->vlans);
412 	macvlan_transfer_operstate(dev);
413 	return 0;
414 }
415 
416 static void macvlan_dellink(struct net_device *dev)
417 {
418 	struct macvlan_dev *vlan = netdev_priv(dev);
419 	struct macvlan_port *port = vlan->port;
420 
421 	list_del(&vlan->list);
422 	unregister_netdevice(dev);
423 
424 	if (list_empty(&port->vlans))
425 		macvlan_port_destroy(dev);
426 }
427 
428 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
429 	.kind		= "macvlan",
430 	.priv_size	= sizeof(struct macvlan_dev),
431 	.setup		= macvlan_setup,
432 	.validate	= macvlan_validate,
433 	.newlink	= macvlan_newlink,
434 	.dellink	= macvlan_dellink,
435 };
436 
437 static int macvlan_device_event(struct notifier_block *unused,
438 				unsigned long event, void *ptr)
439 {
440 	struct net_device *dev = ptr;
441 	struct macvlan_dev *vlan, *next;
442 	struct macvlan_port *port;
443 
444 	port = dev->macvlan_port;
445 	if (port == NULL)
446 		return NOTIFY_DONE;
447 
448 	switch (event) {
449 	case NETDEV_CHANGE:
450 		list_for_each_entry(vlan, &port->vlans, list)
451 			macvlan_transfer_operstate(vlan->dev);
452 		break;
453 	case NETDEV_FEAT_CHANGE:
454 		list_for_each_entry(vlan, &port->vlans, list) {
455 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
456 			netdev_features_change(vlan->dev);
457 		}
458 		break;
459 	case NETDEV_UNREGISTER:
460 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
461 			macvlan_dellink(vlan->dev);
462 		break;
463 	}
464 	return NOTIFY_DONE;
465 }
466 
467 static struct notifier_block macvlan_notifier_block __read_mostly = {
468 	.notifier_call	= macvlan_device_event,
469 };
470 
471 static int __init macvlan_init_module(void)
472 {
473 	int err;
474 
475 	register_netdevice_notifier(&macvlan_notifier_block);
476 	macvlan_handle_frame_hook = macvlan_handle_frame;
477 
478 	err = rtnl_link_register(&macvlan_link_ops);
479 	if (err < 0)
480 		goto err1;
481 	return 0;
482 err1:
483 	macvlan_handle_frame_hook = macvlan_handle_frame;
484 	unregister_netdevice_notifier(&macvlan_notifier_block);
485 	return err;
486 }
487 
488 static void __exit macvlan_cleanup_module(void)
489 {
490 	rtnl_link_unregister(&macvlan_link_ops);
491 	macvlan_handle_frame_hook = NULL;
492 	unregister_netdevice_notifier(&macvlan_notifier_block);
493 }
494 
495 module_init(macvlan_init_module);
496 module_exit(macvlan_cleanup_module);
497 
498 MODULE_LICENSE("GPL");
499 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
500 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
501 MODULE_ALIAS_RTNL_LINK("macvlan");
502