xref: /linux/drivers/net/macvlan.c (revision 8b4a40809e5330c9da5d20107d693d92d73b31dc)
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, void *daddr, void *saddr,
168 			       unsigned len)
169 {
170 	const struct macvlan_dev *vlan = netdev_priv(dev);
171 	struct net_device *lowerdev = vlan->lowerdev;
172 
173 	return lowerdev->hard_header(skb, lowerdev, type, daddr,
174 				     saddr ? : dev->dev_addr, len);
175 }
176 
177 static int macvlan_open(struct net_device *dev)
178 {
179 	struct macvlan_dev *vlan = netdev_priv(dev);
180 	struct macvlan_port *port = vlan->port;
181 	struct net_device *lowerdev = vlan->lowerdev;
182 	int err;
183 
184 	err = dev_unicast_add(lowerdev, dev->dev_addr, ETH_ALEN);
185 	if (err < 0)
186 		return err;
187 	if (dev->flags & IFF_ALLMULTI)
188 		dev_set_allmulti(lowerdev, 1);
189 
190 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
191 	return 0;
192 }
193 
194 static int macvlan_stop(struct net_device *dev)
195 {
196 	struct macvlan_dev *vlan = netdev_priv(dev);
197 	struct net_device *lowerdev = vlan->lowerdev;
198 
199 	dev_mc_unsync(lowerdev, dev);
200 	if (dev->flags & IFF_ALLMULTI)
201 		dev_set_allmulti(lowerdev, -1);
202 
203 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
204 
205 	hlist_del_rcu(&vlan->hlist);
206 	synchronize_rcu();
207 	return 0;
208 }
209 
210 static void macvlan_change_rx_flags(struct net_device *dev, int change)
211 {
212 	struct macvlan_dev *vlan = netdev_priv(dev);
213 	struct net_device *lowerdev = vlan->lowerdev;
214 
215 	if (change & IFF_ALLMULTI)
216 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
217 }
218 
219 static void macvlan_set_multicast_list(struct net_device *dev)
220 {
221 	struct macvlan_dev *vlan = netdev_priv(dev);
222 
223 	dev_mc_sync(vlan->lowerdev, dev);
224 }
225 
226 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
227 {
228 	struct macvlan_dev *vlan = netdev_priv(dev);
229 
230 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
231 		return -EINVAL;
232 	dev->mtu = new_mtu;
233 	return 0;
234 }
235 
236 /*
237  * macvlan network devices have devices nesting below it and are a special
238  * "super class" of normal network devices; split their locks off into a
239  * separate class since they always nest.
240  */
241 static struct lock_class_key macvlan_netdev_xmit_lock_key;
242 
243 #define MACVLAN_FEATURES \
244 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
245 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
246 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
247 
248 #define MACVLAN_STATE_MASK \
249 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
250 
251 static int macvlan_init(struct net_device *dev)
252 {
253 	struct macvlan_dev *vlan = netdev_priv(dev);
254 	const struct net_device *lowerdev = vlan->lowerdev;
255 
256 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
257 				  (lowerdev->state & MACVLAN_STATE_MASK);
258 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
259 	dev->iflink		= lowerdev->ifindex;
260 
261 	lockdep_set_class(&dev->_xmit_lock, &macvlan_netdev_xmit_lock_key);
262 	return 0;
263 }
264 
265 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
266 					struct ethtool_drvinfo *drvinfo)
267 {
268 	snprintf(drvinfo->driver, 32, "macvlan");
269 	snprintf(drvinfo->version, 32, "0.1");
270 }
271 
272 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
273 {
274 	const struct macvlan_dev *vlan = netdev_priv(dev);
275 	struct net_device *lowerdev = vlan->lowerdev;
276 
277 	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
278 		return 0;
279 	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
280 }
281 
282 static const struct ethtool_ops macvlan_ethtool_ops = {
283 	.get_link		= ethtool_op_get_link,
284 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
285 	.get_tx_csum		= ethtool_op_get_tx_csum,
286 	.get_tso		= ethtool_op_get_tso,
287 	.get_ufo		= ethtool_op_get_ufo,
288 	.get_sg			= ethtool_op_get_sg,
289 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
290 };
291 
292 static void macvlan_setup(struct net_device *dev)
293 {
294 	ether_setup(dev);
295 
296 	dev->init		= macvlan_init;
297 	dev->open		= macvlan_open;
298 	dev->stop		= macvlan_stop;
299 	dev->change_mtu		= macvlan_change_mtu;
300 	dev->change_rx_flags	= macvlan_change_rx_flags;
301 	dev->set_multicast_list	= macvlan_set_multicast_list;
302 	dev->hard_header	= macvlan_hard_header;
303 	dev->hard_start_xmit	= macvlan_hard_start_xmit;
304 	dev->destructor		= free_netdev;
305 	dev->ethtool_ops	= &macvlan_ethtool_ops;
306 	dev->tx_queue_len	= 0;
307 }
308 
309 static int macvlan_port_create(struct net_device *dev)
310 {
311 	struct macvlan_port *port;
312 	unsigned int i;
313 
314 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
315 		return -EINVAL;
316 
317 	port = kzalloc(sizeof(*port), GFP_KERNEL);
318 	if (port == NULL)
319 		return -ENOMEM;
320 
321 	port->dev = dev;
322 	INIT_LIST_HEAD(&port->vlans);
323 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
324 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
325 	rcu_assign_pointer(dev->macvlan_port, port);
326 	return 0;
327 }
328 
329 static void macvlan_port_destroy(struct net_device *dev)
330 {
331 	struct macvlan_port *port = dev->macvlan_port;
332 
333 	rcu_assign_pointer(dev->macvlan_port, NULL);
334 	synchronize_rcu();
335 	kfree(port);
336 }
337 
338 static void macvlan_transfer_operstate(struct net_device *dev)
339 {
340 	struct macvlan_dev *vlan = netdev_priv(dev);
341 	const struct net_device *lowerdev = vlan->lowerdev;
342 
343 	if (lowerdev->operstate == IF_OPER_DORMANT)
344 		netif_dormant_on(dev);
345 	else
346 		netif_dormant_off(dev);
347 
348 	if (netif_carrier_ok(lowerdev)) {
349 		if (!netif_carrier_ok(dev))
350 			netif_carrier_on(dev);
351 	} else {
352 		if (netif_carrier_ok(lowerdev))
353 			netif_carrier_off(dev);
354 	}
355 }
356 
357 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
358 {
359 	if (tb[IFLA_ADDRESS]) {
360 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
361 			return -EINVAL;
362 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
363 			return -EADDRNOTAVAIL;
364 	}
365 	return 0;
366 }
367 
368 static int macvlan_newlink(struct net_device *dev,
369 			   struct nlattr *tb[], struct nlattr *data[])
370 {
371 	struct macvlan_dev *vlan = netdev_priv(dev);
372 	struct macvlan_port *port;
373 	struct net_device *lowerdev;
374 	int err;
375 
376 	if (!tb[IFLA_LINK])
377 		return -EINVAL;
378 
379 	lowerdev = __dev_get_by_index(nla_get_u32(tb[IFLA_LINK]));
380 	if (lowerdev == NULL)
381 		return -ENODEV;
382 
383 	if (!tb[IFLA_MTU])
384 		dev->mtu = lowerdev->mtu;
385 	else if (dev->mtu > lowerdev->mtu)
386 		return -EINVAL;
387 
388 	if (!tb[IFLA_ADDRESS])
389 		random_ether_addr(dev->dev_addr);
390 
391 	if (lowerdev->macvlan_port == NULL) {
392 		err = macvlan_port_create(lowerdev);
393 		if (err < 0)
394 			return err;
395 	}
396 	port = lowerdev->macvlan_port;
397 
398 	vlan->lowerdev = lowerdev;
399 	vlan->dev      = dev;
400 	vlan->port     = port;
401 
402 	err = register_netdevice(dev);
403 	if (err < 0)
404 		return err;
405 
406 	list_add_tail(&vlan->list, &port->vlans);
407 	macvlan_transfer_operstate(dev);
408 	return 0;
409 }
410 
411 static void macvlan_dellink(struct net_device *dev)
412 {
413 	struct macvlan_dev *vlan = netdev_priv(dev);
414 	struct macvlan_port *port = vlan->port;
415 
416 	list_del(&vlan->list);
417 	unregister_netdevice(dev);
418 
419 	if (list_empty(&port->vlans))
420 		macvlan_port_destroy(dev);
421 }
422 
423 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
424 	.kind		= "macvlan",
425 	.priv_size	= sizeof(struct macvlan_dev),
426 	.setup		= macvlan_setup,
427 	.validate	= macvlan_validate,
428 	.newlink	= macvlan_newlink,
429 	.dellink	= macvlan_dellink,
430 };
431 
432 static int macvlan_device_event(struct notifier_block *unused,
433 				unsigned long event, void *ptr)
434 {
435 	struct net_device *dev = ptr;
436 	struct macvlan_dev *vlan, *next;
437 	struct macvlan_port *port;
438 
439 	port = dev->macvlan_port;
440 	if (port == NULL)
441 		return NOTIFY_DONE;
442 
443 	switch (event) {
444 	case NETDEV_CHANGE:
445 		list_for_each_entry(vlan, &port->vlans, list)
446 			macvlan_transfer_operstate(vlan->dev);
447 		break;
448 	case NETDEV_FEAT_CHANGE:
449 		list_for_each_entry(vlan, &port->vlans, list) {
450 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
451 			netdev_features_change(vlan->dev);
452 		}
453 		break;
454 	case NETDEV_UNREGISTER:
455 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
456 			macvlan_dellink(vlan->dev);
457 		break;
458 	}
459 	return NOTIFY_DONE;
460 }
461 
462 static struct notifier_block macvlan_notifier_block __read_mostly = {
463 	.notifier_call	= macvlan_device_event,
464 };
465 
466 static int __init macvlan_init_module(void)
467 {
468 	int err;
469 
470 	register_netdevice_notifier(&macvlan_notifier_block);
471 	macvlan_handle_frame_hook = macvlan_handle_frame;
472 
473 	err = rtnl_link_register(&macvlan_link_ops);
474 	if (err < 0)
475 		goto err1;
476 	return 0;
477 err1:
478 	macvlan_handle_frame_hook = macvlan_handle_frame;
479 	unregister_netdevice_notifier(&macvlan_notifier_block);
480 	return err;
481 }
482 
483 static void __exit macvlan_cleanup_module(void)
484 {
485 	rtnl_link_unregister(&macvlan_link_ops);
486 	macvlan_handle_frame_hook = NULL;
487 	unregister_netdevice_notifier(&macvlan_notifier_block);
488 }
489 
490 module_init(macvlan_init_module);
491 module_exit(macvlan_cleanup_module);
492 
493 MODULE_LICENSE("GPL");
494 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
495 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
496 MODULE_ALIAS_RTNL_LINK("macvlan");
497