xref: /openbmc/linux/drivers/net/macvlan.c (revision fd589a8f)
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_64bits(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 (!compare_ether_addr_64bits(port->dev->dev_addr, addr))
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_64bits(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 netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
188 				      struct net_device *dev)
189 {
190 	int i = skb_get_queue_mapping(skb);
191 	struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
192 	const struct macvlan_dev *vlan = netdev_priv(dev);
193 	unsigned int len = skb->len;
194 	int ret;
195 
196 	skb->dev = vlan->lowerdev;
197 	ret = dev_queue_xmit(skb);
198 
199 	if (likely(ret == NET_XMIT_SUCCESS)) {
200 		txq->tx_packets++;
201 		txq->tx_bytes += len;
202 	} else
203 		txq->tx_dropped++;
204 
205 	return NETDEV_TX_OK;
206 }
207 
208 static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
209 			       unsigned short type, const void *daddr,
210 			       const void *saddr, unsigned len)
211 {
212 	const struct macvlan_dev *vlan = netdev_priv(dev);
213 	struct net_device *lowerdev = vlan->lowerdev;
214 
215 	return dev_hard_header(skb, lowerdev, type, daddr,
216 			       saddr ? : dev->dev_addr, len);
217 }
218 
219 static const struct header_ops macvlan_hard_header_ops = {
220 	.create  	= macvlan_hard_header,
221 	.rebuild	= eth_rebuild_header,
222 	.parse		= eth_header_parse,
223 	.cache		= eth_header_cache,
224 	.cache_update	= eth_header_cache_update,
225 };
226 
227 static int macvlan_open(struct net_device *dev)
228 {
229 	struct macvlan_dev *vlan = netdev_priv(dev);
230 	struct net_device *lowerdev = vlan->lowerdev;
231 	int err;
232 
233 	err = -EBUSY;
234 	if (macvlan_addr_busy(vlan->port, dev->dev_addr))
235 		goto out;
236 
237 	err = dev_unicast_add(lowerdev, dev->dev_addr);
238 	if (err < 0)
239 		goto out;
240 	if (dev->flags & IFF_ALLMULTI) {
241 		err = dev_set_allmulti(lowerdev, 1);
242 		if (err < 0)
243 			goto del_unicast;
244 	}
245 	macvlan_hash_add(vlan);
246 	return 0;
247 
248 del_unicast:
249 	dev_unicast_delete(lowerdev, dev->dev_addr);
250 out:
251 	return err;
252 }
253 
254 static int macvlan_stop(struct net_device *dev)
255 {
256 	struct macvlan_dev *vlan = netdev_priv(dev);
257 	struct net_device *lowerdev = vlan->lowerdev;
258 
259 	dev_mc_unsync(lowerdev, dev);
260 	if (dev->flags & IFF_ALLMULTI)
261 		dev_set_allmulti(lowerdev, -1);
262 
263 	dev_unicast_delete(lowerdev, dev->dev_addr);
264 
265 	macvlan_hash_del(vlan);
266 	return 0;
267 }
268 
269 static int macvlan_set_mac_address(struct net_device *dev, void *p)
270 {
271 	struct macvlan_dev *vlan = netdev_priv(dev);
272 	struct net_device *lowerdev = vlan->lowerdev;
273 	struct sockaddr *addr = p;
274 	int err;
275 
276 	if (!is_valid_ether_addr(addr->sa_data))
277 		return -EADDRNOTAVAIL;
278 
279 	if (!(dev->flags & IFF_UP)) {
280 		/* Just copy in the new address */
281 		memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
282 	} else {
283 		/* Rehash and update the device filters */
284 		if (macvlan_addr_busy(vlan->port, addr->sa_data))
285 			return -EBUSY;
286 
287 		err = dev_unicast_add(lowerdev, addr->sa_data);
288 		if (err)
289 			return err;
290 
291 		dev_unicast_delete(lowerdev, dev->dev_addr);
292 
293 		macvlan_hash_change_addr(vlan, addr->sa_data);
294 	}
295 	return 0;
296 }
297 
298 static void macvlan_change_rx_flags(struct net_device *dev, int change)
299 {
300 	struct macvlan_dev *vlan = netdev_priv(dev);
301 	struct net_device *lowerdev = vlan->lowerdev;
302 
303 	if (change & IFF_ALLMULTI)
304 		dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
305 }
306 
307 static void macvlan_set_multicast_list(struct net_device *dev)
308 {
309 	struct macvlan_dev *vlan = netdev_priv(dev);
310 
311 	dev_mc_sync(vlan->lowerdev, dev);
312 }
313 
314 static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
315 {
316 	struct macvlan_dev *vlan = netdev_priv(dev);
317 
318 	if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
319 		return -EINVAL;
320 	dev->mtu = new_mtu;
321 	return 0;
322 }
323 
324 /*
325  * macvlan network devices have devices nesting below it and are a special
326  * "super class" of normal network devices; split their locks off into a
327  * separate class since they always nest.
328  */
329 static struct lock_class_key macvlan_netdev_xmit_lock_key;
330 static struct lock_class_key macvlan_netdev_addr_lock_key;
331 
332 #define MACVLAN_FEATURES \
333 	(NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
334 	 NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \
335 	 NETIF_F_TSO_ECN | NETIF_F_TSO6)
336 
337 #define MACVLAN_STATE_MASK \
338 	((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))
339 
340 static void macvlan_set_lockdep_class_one(struct net_device *dev,
341 					  struct netdev_queue *txq,
342 					  void *_unused)
343 {
344 	lockdep_set_class(&txq->_xmit_lock,
345 			  &macvlan_netdev_xmit_lock_key);
346 }
347 
348 static void macvlan_set_lockdep_class(struct net_device *dev)
349 {
350 	lockdep_set_class(&dev->addr_list_lock,
351 			  &macvlan_netdev_addr_lock_key);
352 	netdev_for_each_tx_queue(dev, macvlan_set_lockdep_class_one, NULL);
353 }
354 
355 static int macvlan_init(struct net_device *dev)
356 {
357 	struct macvlan_dev *vlan = netdev_priv(dev);
358 	const struct net_device *lowerdev = vlan->lowerdev;
359 
360 	dev->state		= (dev->state & ~MACVLAN_STATE_MASK) |
361 				  (lowerdev->state & MACVLAN_STATE_MASK);
362 	dev->features 		= lowerdev->features & MACVLAN_FEATURES;
363 	dev->iflink		= lowerdev->ifindex;
364 	dev->hard_header_len	= lowerdev->hard_header_len;
365 
366 	macvlan_set_lockdep_class(dev);
367 
368 	return 0;
369 }
370 
371 static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
372 					struct ethtool_drvinfo *drvinfo)
373 {
374 	snprintf(drvinfo->driver, 32, "macvlan");
375 	snprintf(drvinfo->version, 32, "0.1");
376 }
377 
378 static u32 macvlan_ethtool_get_rx_csum(struct net_device *dev)
379 {
380 	const struct macvlan_dev *vlan = netdev_priv(dev);
381 	return dev_ethtool_get_rx_csum(vlan->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 	return dev_ethtool_get_settings(vlan->lowerdev, cmd);
389 }
390 
391 static u32 macvlan_ethtool_get_flags(struct net_device *dev)
392 {
393 	const struct macvlan_dev *vlan = netdev_priv(dev);
394 	return dev_ethtool_get_flags(vlan->lowerdev);
395 }
396 
397 static const struct ethtool_ops macvlan_ethtool_ops = {
398 	.get_link		= ethtool_op_get_link,
399 	.get_settings		= macvlan_ethtool_get_settings,
400 	.get_rx_csum		= macvlan_ethtool_get_rx_csum,
401 	.get_drvinfo		= macvlan_ethtool_get_drvinfo,
402 	.get_flags		= macvlan_ethtool_get_flags,
403 };
404 
405 static const struct net_device_ops macvlan_netdev_ops = {
406 	.ndo_init		= macvlan_init,
407 	.ndo_open		= macvlan_open,
408 	.ndo_stop		= macvlan_stop,
409 	.ndo_start_xmit		= macvlan_start_xmit,
410 	.ndo_change_mtu		= macvlan_change_mtu,
411 	.ndo_change_rx_flags	= macvlan_change_rx_flags,
412 	.ndo_set_mac_address	= macvlan_set_mac_address,
413 	.ndo_set_multicast_list	= macvlan_set_multicast_list,
414 	.ndo_validate_addr	= eth_validate_addr,
415 };
416 
417 static void macvlan_setup(struct net_device *dev)
418 {
419 	ether_setup(dev);
420 
421 	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
422 	dev->netdev_ops		= &macvlan_netdev_ops;
423 	dev->destructor		= free_netdev;
424 	dev->header_ops		= &macvlan_hard_header_ops,
425 	dev->ethtool_ops	= &macvlan_ethtool_ops;
426 	dev->tx_queue_len	= 0;
427 }
428 
429 static int macvlan_port_create(struct net_device *dev)
430 {
431 	struct macvlan_port *port;
432 	unsigned int i;
433 
434 	if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
435 		return -EINVAL;
436 
437 	port = kzalloc(sizeof(*port), GFP_KERNEL);
438 	if (port == NULL)
439 		return -ENOMEM;
440 
441 	port->dev = dev;
442 	INIT_LIST_HEAD(&port->vlans);
443 	for (i = 0; i < MACVLAN_HASH_SIZE; i++)
444 		INIT_HLIST_HEAD(&port->vlan_hash[i]);
445 	rcu_assign_pointer(dev->macvlan_port, port);
446 	return 0;
447 }
448 
449 static void macvlan_port_destroy(struct net_device *dev)
450 {
451 	struct macvlan_port *port = dev->macvlan_port;
452 
453 	rcu_assign_pointer(dev->macvlan_port, NULL);
454 	synchronize_rcu();
455 	kfree(port);
456 }
457 
458 static void macvlan_transfer_operstate(struct net_device *dev)
459 {
460 	struct macvlan_dev *vlan = netdev_priv(dev);
461 	const struct net_device *lowerdev = vlan->lowerdev;
462 
463 	if (lowerdev->operstate == IF_OPER_DORMANT)
464 		netif_dormant_on(dev);
465 	else
466 		netif_dormant_off(dev);
467 
468 	if (netif_carrier_ok(lowerdev)) {
469 		if (!netif_carrier_ok(dev))
470 			netif_carrier_on(dev);
471 	} else {
472 		if (netif_carrier_ok(dev))
473 			netif_carrier_off(dev);
474 	}
475 }
476 
477 static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[])
478 {
479 	if (tb[IFLA_ADDRESS]) {
480 		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
481 			return -EINVAL;
482 		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
483 			return -EADDRNOTAVAIL;
484 	}
485 	return 0;
486 }
487 
488 static int macvlan_get_tx_queues(struct net *net,
489 				 struct nlattr *tb[],
490 				 unsigned int *num_tx_queues,
491 				 unsigned int *real_num_tx_queues)
492 {
493 	struct net_device *real_dev;
494 
495 	if (!tb[IFLA_LINK])
496 		return -EINVAL;
497 
498 	real_dev = __dev_get_by_index(net, nla_get_u32(tb[IFLA_LINK]));
499 	if (!real_dev)
500 		return -ENODEV;
501 
502 	*num_tx_queues      = real_dev->num_tx_queues;
503 	*real_num_tx_queues = real_dev->real_num_tx_queues;
504 	return 0;
505 }
506 
507 static int macvlan_newlink(struct net_device *dev,
508 			   struct nlattr *tb[], struct nlattr *data[])
509 {
510 	struct macvlan_dev *vlan = netdev_priv(dev);
511 	struct macvlan_port *port;
512 	struct net_device *lowerdev;
513 	int err;
514 
515 	if (!tb[IFLA_LINK])
516 		return -EINVAL;
517 
518 	lowerdev = __dev_get_by_index(dev_net(dev), nla_get_u32(tb[IFLA_LINK]));
519 	if (lowerdev == NULL)
520 		return -ENODEV;
521 
522 	/* When creating macvlans on top of other macvlans - use
523 	 * the real device as the lowerdev.
524 	 */
525 	if (lowerdev->rtnl_link_ops == dev->rtnl_link_ops) {
526 		struct macvlan_dev *lowervlan = netdev_priv(lowerdev);
527 		lowerdev = lowervlan->lowerdev;
528 	}
529 
530 	if (!tb[IFLA_MTU])
531 		dev->mtu = lowerdev->mtu;
532 	else if (dev->mtu > lowerdev->mtu)
533 		return -EINVAL;
534 
535 	if (!tb[IFLA_ADDRESS])
536 		random_ether_addr(dev->dev_addr);
537 
538 	if (lowerdev->macvlan_port == NULL) {
539 		err = macvlan_port_create(lowerdev);
540 		if (err < 0)
541 			return err;
542 	}
543 	port = lowerdev->macvlan_port;
544 
545 	vlan->lowerdev = lowerdev;
546 	vlan->dev      = dev;
547 	vlan->port     = port;
548 
549 	err = register_netdevice(dev);
550 	if (err < 0)
551 		return err;
552 
553 	list_add_tail(&vlan->list, &port->vlans);
554 	macvlan_transfer_operstate(dev);
555 	return 0;
556 }
557 
558 static void macvlan_dellink(struct net_device *dev)
559 {
560 	struct macvlan_dev *vlan = netdev_priv(dev);
561 	struct macvlan_port *port = vlan->port;
562 
563 	list_del(&vlan->list);
564 	unregister_netdevice(dev);
565 
566 	if (list_empty(&port->vlans))
567 		macvlan_port_destroy(port->dev);
568 }
569 
570 static struct rtnl_link_ops macvlan_link_ops __read_mostly = {
571 	.kind		= "macvlan",
572 	.priv_size	= sizeof(struct macvlan_dev),
573 	.get_tx_queues  = macvlan_get_tx_queues,
574 	.setup		= macvlan_setup,
575 	.validate	= macvlan_validate,
576 	.newlink	= macvlan_newlink,
577 	.dellink	= macvlan_dellink,
578 };
579 
580 static int macvlan_device_event(struct notifier_block *unused,
581 				unsigned long event, void *ptr)
582 {
583 	struct net_device *dev = ptr;
584 	struct macvlan_dev *vlan, *next;
585 	struct macvlan_port *port;
586 
587 	port = dev->macvlan_port;
588 	if (port == NULL)
589 		return NOTIFY_DONE;
590 
591 	switch (event) {
592 	case NETDEV_CHANGE:
593 		list_for_each_entry(vlan, &port->vlans, list)
594 			macvlan_transfer_operstate(vlan->dev);
595 		break;
596 	case NETDEV_FEAT_CHANGE:
597 		list_for_each_entry(vlan, &port->vlans, list) {
598 			vlan->dev->features = dev->features & MACVLAN_FEATURES;
599 			netdev_features_change(vlan->dev);
600 		}
601 		break;
602 	case NETDEV_UNREGISTER:
603 		list_for_each_entry_safe(vlan, next, &port->vlans, list)
604 			macvlan_dellink(vlan->dev);
605 		break;
606 	}
607 	return NOTIFY_DONE;
608 }
609 
610 static struct notifier_block macvlan_notifier_block __read_mostly = {
611 	.notifier_call	= macvlan_device_event,
612 };
613 
614 static int __init macvlan_init_module(void)
615 {
616 	int err;
617 
618 	register_netdevice_notifier(&macvlan_notifier_block);
619 	macvlan_handle_frame_hook = macvlan_handle_frame;
620 
621 	err = rtnl_link_register(&macvlan_link_ops);
622 	if (err < 0)
623 		goto err1;
624 	return 0;
625 err1:
626 	macvlan_handle_frame_hook = NULL;
627 	unregister_netdevice_notifier(&macvlan_notifier_block);
628 	return err;
629 }
630 
631 static void __exit macvlan_cleanup_module(void)
632 {
633 	rtnl_link_unregister(&macvlan_link_ops);
634 	macvlan_handle_frame_hook = NULL;
635 	unregister_netdevice_notifier(&macvlan_notifier_block);
636 }
637 
638 module_init(macvlan_init_module);
639 module_exit(macvlan_cleanup_module);
640 
641 MODULE_LICENSE("GPL");
642 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
643 MODULE_DESCRIPTION("Driver for MAC address based VLANs");
644 MODULE_ALIAS_RTNL_LINK("macvlan");
645