xref: /openbmc/linux/drivers/net/macvlan.c (revision 643d1f7f)
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 
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 		return err;
193 	if (dev->flags & IFF_ALLMULTI)
194 		dev_set_allmulti(lowerdev, 1);
195 
196 	hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[dev->dev_addr[5]]);
197 	return 0;
198 }
199 
200 static int macvlan_stop(struct net_device *dev)
201 {
202 	struct macvlan_dev *vlan = netdev_priv(dev);
203 	struct net_device *lowerdev = vlan->lowerdev;
204 
205 	dev_mc_unsync(lowerdev, dev);
206 	if (dev->flags & IFF_ALLMULTI)
207 		dev_set_allmulti(lowerdev, -1);
208 
209 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
210 
211 	hlist_del_rcu(&vlan->hlist);
212 	synchronize_rcu();
213 	return 0;
214 }
215 
216 static int macvlan_set_mac_address(struct net_device *dev, void *p)
217 {
218 	struct macvlan_dev *vlan = netdev_priv(dev);
219 	struct net_device *lowerdev = vlan->lowerdev;
220 	struct sockaddr *addr = p;
221 	int err;
222 
223 	if (!is_valid_ether_addr(addr->sa_data))
224 		return -EADDRNOTAVAIL;
225 
226 	if (!(dev->flags & IFF_UP))
227 		goto out;
228 
229 	err = dev_unicast_add(lowerdev, addr->sa_data, ETH_ALEN);
230 	if (err < 0)
231 		return err;
232 	dev_unicast_delete(lowerdev, dev->dev_addr, ETH_ALEN);
233 
234 out:
235 	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
236 	return 0;
237 }
238 
239 static void macvlan_change_rx_flags(struct net_device *dev, int change)
240 {
241 	struct macvlan_dev *vlan = netdev_priv(dev);
242 	struct net_device *lowerdev = vlan->lowerdev;
243 
244 	if (change & IFF_ALLMULTI)
245 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
246 }
247 
248 static void macvlan_set_multicast_list(struct net_device *dev)
249 {
250 	struct macvlan_dev *vlan = netdev_priv(dev);
251 
252 	dev_mc_sync(vlan->lowerdev, dev);
253 }
254 
255 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
256 {
257 	struct macvlan_dev *vlan = netdev_priv(dev);
258 
259 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
260 		return -EINVAL;
261 	dev->mtu = new_mtu;
262 	return 0;
263 }
264 
265 /*
266  * macvlan network devices have devices nesting below it and are a special
267  * "super class" of normal network devices; split their locks off into a
268  * separate class since they always nest.
269  */
270 static struct lock_class_key macvlan_netdev_xmit_lock_key;
271 
272 #define MACVLAN_FEATURES \
273 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
274 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
275 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
276 
277 #define MACVLAN_STATE_MASK \
278 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
279 
280 static int macvlan_init(struct net_device *dev)
281 {
282 	struct macvlan_dev *vlan = netdev_priv(dev);
283 	const struct net_device *lowerdev = vlan->lowerdev;
284 
285 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
286 				  (lowerdev->state & MACVLAN_STATE_MASK);
287 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
288 	dev->iflink		= lowerdev->ifindex;
289 
290 	lockdep_set_class(&dev->_xmit_lock, &macvlan_netdev_xmit_lock_key);
291 	return 0;
292 }
293 
294 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
295 					struct ethtool_drvinfo *drvinfo)
296 {
297 	snprintf(drvinfo->driver, 32, "macvlan");
298 	snprintf(drvinfo->version, 32, "0.1");
299 }
300 
301 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
302 {
303 	const struct macvlan_dev *vlan = netdev_priv(dev);
304 	struct net_device *lowerdev = vlan->lowerdev;
305 
306 	if (lowerdev->ethtool_ops->get_rx_csum == NULL)
307 		return 0;
308 	return lowerdev->ethtool_ops->get_rx_csum(lowerdev);
309 }
310 
311 static const struct ethtool_ops macvlan_ethtool_ops = {
312 	.get_link		= ethtool_op_get_link,
313 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
314 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
315 };
316 
317 static void macvlan_setup(struct net_device *dev)
318 {
319 	ether_setup(dev);
320 
321 	dev->init		= macvlan_init;
322 	dev->open		= macvlan_open;
323 	dev->stop		= macvlan_stop;
324 	dev->change_mtu		= macvlan_change_mtu;
325 	dev->change_rx_flags	= macvlan_change_rx_flags;
326 	dev->set_mac_address	= macvlan_set_mac_address;
327 	dev->set_multicast_list	= macvlan_set_multicast_list;
328 	dev->hard_start_xmit	= macvlan_hard_start_xmit;
329 	dev->destructor		= free_netdev;
330 	dev->header_ops		= &macvlan_hard_header_ops,
331 	dev->ethtool_ops	= &macvlan_ethtool_ops;
332 	dev->tx_queue_len	= 0;
333 }
334 
335 static int macvlan_port_create(struct net_device *dev)
336 {
337 	struct macvlan_port *port;
338 	unsigned int i;
339 
340 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
341 		return -EINVAL;
342 
343 	port = kzalloc(sizeof(*port), GFP_KERNEL);
344 	if (port == NULL)
345 		return -ENOMEM;
346 
347 	port->dev = dev;
348 	INIT_LIST_HEAD(&port->vlans);
349 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
350 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
351 	rcu_assign_pointer(dev->macvlan_port, port);
352 	return 0;
353 }
354 
355 static void macvlan_port_destroy(struct net_device *dev)
356 {
357 	struct macvlan_port *port = dev->macvlan_port;
358 
359 	rcu_assign_pointer(dev->macvlan_port, NULL);
360 	synchronize_rcu();
361 	kfree(port);
362 }
363 
364 static void macvlan_transfer_operstate(struct net_device *dev)
365 {
366 	struct macvlan_dev *vlan = netdev_priv(dev);
367 	const struct net_device *lowerdev = vlan->lowerdev;
368 
369 	if (lowerdev->operstate == IF_OPER_DORMANT)
370 		netif_dormant_on(dev);
371 	else
372 		netif_dormant_off(dev);
373 
374 	if (netif_carrier_ok(lowerdev)) {
375 		if (!netif_carrier_ok(dev))
376 			netif_carrier_on(dev);
377 	} else {
378 		if (netif_carrier_ok(dev))
379 			netif_carrier_off(dev);
380 	}
381 }
382 
383 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
384 {
385 	if (tb[IFLA_ADDRESS]) {
386 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
387 			return -EINVAL;
388 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
389 			return -EADDRNOTAVAIL;
390 	}
391 	return 0;
392 }
393 
394 static int macvlan_newlink(struct net_device *dev,
395 			   struct nlattr *tb[], struct nlattr *data[])
396 {
397 	struct macvlan_dev *vlan = netdev_priv(dev);
398 	struct macvlan_port *port;
399 	struct net_device *lowerdev;
400 	int err;
401 
402 	if (!tb[IFLA_LINK])
403 		return -EINVAL;
404 
405 	lowerdev = __dev_get_by_index(dev->nd_net, nla_get_u32(tb[IFLA_LINK]));
406 	if (lowerdev == NULL)
407 		return -ENODEV;
408 
409 	/* Don't allow macvlans on top of other macvlans - its not really
410 	 * wrong, but lockdep can't handle it and its not useful for anything
411 	 * you couldn't do directly on top of the real device.
412 	 */
413 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops)
414 		return -ENODEV;
415 
416 	if (!tb[IFLA_MTU])
417 		dev->mtu = lowerdev->mtu;
418 	else if (dev->mtu > lowerdev->mtu)
419 		return -EINVAL;
420 
421 	if (!tb[IFLA_ADDRESS])
422 		random_ether_addr(dev->dev_addr);
423 
424 	if (lowerdev->macvlan_port == NULL) {
425 		err = macvlan_port_create(lowerdev);
426 		if (err < 0)
427 			return err;
428 	}
429 	port = lowerdev->macvlan_port;
430 
431 	vlan->lowerdev = lowerdev;
432 	vlan->dev      = dev;
433 	vlan->port     = port;
434 
435 	err = register_netdevice(dev);
436 	if (err < 0)
437 		return err;
438 
439 	list_add_tail(&vlan->list, &port->vlans);
440 	macvlan_transfer_operstate(dev);
441 	return 0;
442 }
443 
444 static void macvlan_dellink(struct net_device *dev)
445 {
446 	struct macvlan_dev *vlan = netdev_priv(dev);
447 	struct macvlan_port *port = vlan->port;
448 
449 	list_del(&vlan->list);
450 	unregister_netdevice(dev);
451 
452 	if (list_empty(&port->vlans))
453 		macvlan_port_destroy(dev);
454 }
455 
456 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
457 	.kind		= "macvlan",
458 	.priv_size	= sizeof(struct macvlan_dev),
459 	.setup		= macvlan_setup,
460 	.validate	= macvlan_validate,
461 	.newlink	= macvlan_newlink,
462 	.dellink	= macvlan_dellink,
463 };
464 
465 static int macvlan_device_event(struct notifier_block *unused,
466 				unsigned long event, void *ptr)
467 {
468 	struct net_device *dev = ptr;
469 	struct macvlan_dev *vlan, *next;
470 	struct macvlan_port *port;
471 
472 	port = dev->macvlan_port;
473 	if (port == NULL)
474 		return NOTIFY_DONE;
475 
476 	switch (event) {
477 	case NETDEV_CHANGE:
478 		list_for_each_entry(vlan, &port->vlans, list)
479 			macvlan_transfer_operstate(vlan->dev);
480 		break;
481 	case NETDEV_FEAT_CHANGE:
482 		list_for_each_entry(vlan, &port->vlans, list) {
483 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
484 			netdev_features_change(vlan->dev);
485 		}
486 		break;
487 	case NETDEV_UNREGISTER:
488 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
489 			macvlan_dellink(vlan->dev);
490 		break;
491 	}
492 	return NOTIFY_DONE;
493 }
494 
495 static struct notifier_block macvlan_notifier_block __read_mostly = {
496 	.notifier_call	= macvlan_device_event,
497 };
498 
499 static int __init macvlan_init_module(void)
500 {
501 	int err;
502 
503 	register_netdevice_notifier(&macvlan_notifier_block);
504 	macvlan_handle_frame_hook = macvlan_handle_frame;
505 
506 	err = rtnl_link_register(&macvlan_link_ops);
507 	if (err < 0)
508 		goto err1;
509 	return 0;
510 err1:
511 	macvlan_handle_frame_hook = NULL;
512 	unregister_netdevice_notifier(&macvlan_notifier_block);
513 	return err;
514 }
515 
516 static void __exit macvlan_cleanup_module(void)
517 {
518 	rtnl_link_unregister(&macvlan_link_ops);
519 	macvlan_handle_frame_hook = NULL;
520 	unregister_netdevice_notifier(&macvlan_notifier_block);
521 }
522 
523 module_init(macvlan_init_module);
524 module_exit(macvlan_cleanup_module);
525 
526 MODULE_LICENSE("GPL");
527 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
528 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
529 MODULE_ALIAS_RTNL_LINK("macvlan");
530