vlan.c revision 30688a9a3e06d83d187658bd1c15f0e306bed38b 
1/*
2 * INET		802.1Q VLAN
3 *		Ethernet-type device handling.
4 *
5 * Authors:	Ben Greear <greearb@candelatech.com>
6 *              Please send support related email to: netdev@vger.kernel.org
7 *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
8 *
9 * Fixes:
10 *              Fix for packet capture - Nick Eggleston <nick@dccinc.com>;
11 *		Add HW acceleration hooks - David S. Miller <davem@redhat.com>;
12 *		Correct all the locking - David S. Miller <davem@redhat.com>;
13 *		Use hash table for VLAN groups - David S. Miller <davem@redhat.com>
14 *
15 *		This program is free software; you can redistribute it and/or
16 *		modify it under the terms of the GNU General Public License
17 *		as published by the Free Software Foundation; either version
18 *		2 of the License, or (at your option) any later version.
19 */
20
21#include <asm/uaccess.h> /* for copy_from_user */
22#include <linux/capability.h>
23#include <linux/module.h>
24#include <linux/netdevice.h>
25#include <linux/skbuff.h>
26#include <net/datalink.h>
27#include <linux/mm.h>
28#include <linux/in.h>
29#include <linux/init.h>
30#include <net/p8022.h>
31#include <net/arp.h>
32#include <linux/rtnetlink.h>
33#include <linux/notifier.h>
34#include <net/net_namespace.h>
35#include <net/netns/generic.h>
36
37#include <linux/if_vlan.h>
38#include "vlan.h"
39#include "vlanproc.h"
40
41#define DRV_VERSION "1.8"
42
43/* Global VLAN variables */
44
45int vlan_net_id;
46
47/* Our listing of VLAN group(s) */
48static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
49
50static char vlan_fullname[] = "802.1Q VLAN Support";
51static char vlan_version[] = DRV_VERSION;
52static char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
53static char vlan_buggyright[] = "David S. Miller <davem@redhat.com>";
54
55static struct packet_type vlan_packet_type = {
56	.type = __constant_htons(ETH_P_8021Q),
57	.func = vlan_skb_recv, /* VLAN receive method */
58};
59
60/* End of global variables definitions. */
61
62static inline unsigned int vlan_grp_hashfn(unsigned int idx)
63{
64	return ((idx >> VLAN_GRP_HASH_SHIFT) ^ idx) & VLAN_GRP_HASH_MASK;
65}
66
67/* Must be invoked with RCU read lock (no preempt) */
68static struct vlan_group *__vlan_find_group(struct net_device *real_dev)
69{
70	struct vlan_group *grp;
71	struct hlist_node *n;
72	int hash = vlan_grp_hashfn(real_dev->ifindex);
73
74	hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
75		if (grp->real_dev == real_dev)
76			return grp;
77	}
78
79	return NULL;
80}
81
82/*  Find the protocol handler.  Assumes VID < VLAN_VID_MASK.
83 *
84 * Must be invoked with RCU read lock (no preempt)
85 */
86struct net_device *__find_vlan_dev(struct net_device *real_dev,
87				   unsigned short VID)
88{
89	struct vlan_group *grp = __vlan_find_group(real_dev);
90
91	if (grp)
92		return vlan_group_get_device(grp, VID);
93
94	return NULL;
95}
96
97static void vlan_group_free(struct vlan_group *grp)
98{
99	int i;
100
101	for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
102		kfree(grp->vlan_devices_arrays[i]);
103	kfree(grp);
104}
105
106static struct vlan_group *vlan_group_alloc(struct net_device *real_dev)
107{
108	struct vlan_group *grp;
109
110	grp = kzalloc(sizeof(struct vlan_group), GFP_KERNEL);
111	if (!grp)
112		return NULL;
113
114	grp->real_dev = real_dev;
115	hlist_add_head_rcu(&grp->hlist,
116			&vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]);
117	return grp;
118}
119
120static int vlan_group_prealloc_vid(struct vlan_group *vg, int vid)
121{
122	struct net_device **array;
123	unsigned int size;
124
125	ASSERT_RTNL();
126
127	array = vg->vlan_devices_arrays[vid / VLAN_GROUP_ARRAY_PART_LEN];
128	if (array != NULL)
129		return 0;
130
131	size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
132	array = kzalloc(size, GFP_KERNEL);
133	if (array == NULL)
134		return -ENOBUFS;
135
136	vg->vlan_devices_arrays[vid / VLAN_GROUP_ARRAY_PART_LEN] = array;
137	return 0;
138}
139
140static void vlan_rcu_free(struct rcu_head *rcu)
141{
142	vlan_group_free(container_of(rcu, struct vlan_group, rcu));
143}
144
145void unregister_vlan_dev(struct net_device *dev)
146{
147	struct vlan_dev_info *vlan = vlan_dev_info(dev);
148	struct net_device *real_dev = vlan->real_dev;
149	struct vlan_group *grp;
150	unsigned short vlan_id = vlan->vlan_id;
151
152	ASSERT_RTNL();
153
154	grp = __vlan_find_group(real_dev);
155	BUG_ON(!grp);
156
157	/* Take it out of our own structures, but be sure to interlock with
158	 * HW accelerating devices or SW vlan input packet processing.
159	 */
160	if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
161		real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
162
163	vlan_group_set_device(grp, vlan_id, NULL);
164	grp->nr_vlans--;
165
166	synchronize_net();
167
168	/* If the group is now empty, kill off the group. */
169	if (grp->nr_vlans == 0) {
170		if (real_dev->features & NETIF_F_HW_VLAN_RX)
171			real_dev->vlan_rx_register(real_dev, NULL);
172
173		hlist_del_rcu(&grp->hlist);
174
175		/* Free the group, after all cpu's are done. */
176		call_rcu(&grp->rcu, vlan_rcu_free);
177	}
178
179	/* Get rid of the vlan's reference to real_dev */
180	dev_put(real_dev);
181
182	unregister_netdevice(dev);
183}
184
185static void vlan_transfer_operstate(const struct net_device *dev,
186				    struct net_device *vlandev)
187{
188	/* Have to respect userspace enforced dormant state
189	 * of real device, also must allow supplicant running
190	 * on VLAN device
191	 */
192	if (dev->operstate == IF_OPER_DORMANT)
193		netif_dormant_on(vlandev);
194	else
195		netif_dormant_off(vlandev);
196
197	if (netif_carrier_ok(dev)) {
198		if (!netif_carrier_ok(vlandev))
199			netif_carrier_on(vlandev);
200	} else {
201		if (netif_carrier_ok(vlandev))
202			netif_carrier_off(vlandev);
203	}
204}
205
206int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id)
207{
208	char *name = real_dev->name;
209
210	if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
211		pr_info("8021q: VLANs not supported on %s\n", name);
212		return -EOPNOTSUPP;
213	}
214
215	if ((real_dev->features & NETIF_F_HW_VLAN_RX) &&
216	    !real_dev->vlan_rx_register) {
217		pr_info("8021q: device %s has buggy VLAN hw accel\n", name);
218		return -EOPNOTSUPP;
219	}
220
221	if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
222	    (!real_dev->vlan_rx_add_vid || !real_dev->vlan_rx_kill_vid)) {
223		pr_info("8021q: Device %s has buggy VLAN hw accel\n", name);
224		return -EOPNOTSUPP;
225	}
226
227	/* The real device must be up and operating in order to
228	 * assosciate a VLAN device with it.
229	 */
230	if (!(real_dev->flags & IFF_UP))
231		return -ENETDOWN;
232
233	if (__find_vlan_dev(real_dev, vlan_id) != NULL)
234		return -EEXIST;
235
236	return 0;
237}
238
239int register_vlan_dev(struct net_device *dev)
240{
241	struct vlan_dev_info *vlan = vlan_dev_info(dev);
242	struct net_device *real_dev = vlan->real_dev;
243	unsigned short vlan_id = vlan->vlan_id;
244	struct vlan_group *grp, *ngrp = NULL;
245	int err;
246
247	grp = __vlan_find_group(real_dev);
248	if (!grp) {
249		ngrp = grp = vlan_group_alloc(real_dev);
250		if (!grp)
251			return -ENOBUFS;
252	}
253
254	err = vlan_group_prealloc_vid(grp, vlan_id);
255	if (err < 0)
256		goto out_free_group;
257
258	err = register_netdevice(dev);
259	if (err < 0)
260		goto out_free_group;
261
262	/* Account for reference in struct vlan_dev_info */
263	dev_hold(real_dev);
264
265	vlan_transfer_operstate(real_dev, dev);
266	linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */
267
268	/* So, got the sucker initialized, now lets place
269	 * it into our local structure.
270	 */
271	vlan_group_set_device(grp, vlan_id, dev);
272	grp->nr_vlans++;
273
274	if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX)
275		real_dev->vlan_rx_register(real_dev, ngrp);
276	if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
277		real_dev->vlan_rx_add_vid(real_dev, vlan_id);
278
279	return 0;
280
281out_free_group:
282	if (ngrp)
283		vlan_group_free(ngrp);
284	return err;
285}
286
287/*  Attach a VLAN device to a mac address (ie Ethernet Card).
288 *  Returns 0 if the device was created or a negative error code otherwise.
289 */
290static int register_vlan_device(struct net_device *real_dev,
291				unsigned short VLAN_ID)
292{
293	struct net_device *new_dev;
294	struct net *net = dev_net(real_dev);
295	struct vlan_net *vn = net_generic(net, vlan_net_id);
296	char name[IFNAMSIZ];
297	int err;
298
299	if (VLAN_ID >= VLAN_VID_MASK)
300		return -ERANGE;
301
302	err = vlan_check_real_dev(real_dev, VLAN_ID);
303	if (err < 0)
304		return err;
305
306	/* Gotta set up the fields for the device. */
307	switch (vn->name_type) {
308	case VLAN_NAME_TYPE_RAW_PLUS_VID:
309		/* name will look like:	 eth1.0005 */
310		snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, VLAN_ID);
311		break;
312	case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
313		/* Put our vlan.VID in the name.
314		 * Name will look like:	 vlan5
315		 */
316		snprintf(name, IFNAMSIZ, "vlan%i", VLAN_ID);
317		break;
318	case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
319		/* Put our vlan.VID in the name.
320		 * Name will look like:	 eth0.5
321		 */
322		snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, VLAN_ID);
323		break;
324	case VLAN_NAME_TYPE_PLUS_VID:
325		/* Put our vlan.VID in the name.
326		 * Name will look like:	 vlan0005
327		 */
328	default:
329		snprintf(name, IFNAMSIZ, "vlan%.4i", VLAN_ID);
330	}
331
332	new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
333			       vlan_setup);
334
335	if (new_dev == NULL)
336		return -ENOBUFS;
337
338	dev_net_set(new_dev, net);
339	/* need 4 bytes for extra VLAN header info,
340	 * hope the underlying device can handle it.
341	 */
342	new_dev->mtu = real_dev->mtu;
343
344	vlan_dev_info(new_dev)->vlan_id = VLAN_ID; /* 1 through VLAN_VID_MASK */
345	vlan_dev_info(new_dev)->real_dev = real_dev;
346	vlan_dev_info(new_dev)->dent = NULL;
347	vlan_dev_info(new_dev)->flags = VLAN_FLAG_REORDER_HDR;
348
349	new_dev->rtnl_link_ops = &vlan_link_ops;
350	err = register_vlan_dev(new_dev);
351	if (err < 0)
352		goto out_free_newdev;
353
354	return 0;
355
356out_free_newdev:
357	free_netdev(new_dev);
358	return err;
359}
360
361static void vlan_sync_address(struct net_device *dev,
362			      struct net_device *vlandev)
363{
364	struct vlan_dev_info *vlan = vlan_dev_info(vlandev);
365
366	/* May be called without an actual change */
367	if (!compare_ether_addr(vlan->real_dev_addr, dev->dev_addr))
368		return;
369
370	/* vlan address was different from the old address and is equal to
371	 * the new address */
372	if (compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
373	    !compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
374		dev_unicast_delete(dev, vlandev->dev_addr, ETH_ALEN);
375
376	/* vlan address was equal to the old address and is different from
377	 * the new address */
378	if (!compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
379	    compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
380		dev_unicast_add(dev, vlandev->dev_addr, ETH_ALEN);
381
382	memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
383}
384
385static void __vlan_device_event(struct net_device *dev, unsigned long event)
386{
387	switch (event) {
388	case NETDEV_CHANGENAME:
389		vlan_proc_rem_dev(dev);
390		if (vlan_proc_add_dev(dev) < 0)
391			pr_warning("8021q: failed to change proc name for %s\n",
392					dev->name);
393		break;
394	case NETDEV_REGISTER:
395		if (vlan_proc_add_dev(dev) < 0)
396			pr_warning("8021q: failed to add proc entry for %s\n",
397					dev->name);
398		break;
399	case NETDEV_UNREGISTER:
400		vlan_proc_rem_dev(dev);
401		break;
402	}
403}
404
405static int vlan_device_event(struct notifier_block *unused, unsigned long event,
406			     void *ptr)
407{
408	struct net_device *dev = ptr;
409	struct vlan_group *grp;
410	int i, flgs;
411	struct net_device *vlandev;
412
413	if (is_vlan_dev(dev)) {
414		__vlan_device_event(dev, event);
415		goto out;
416	}
417
418	grp = __vlan_find_group(dev);
419	if (!grp)
420		goto out;
421
422	/* It is OK that we do not hold the group lock right now,
423	 * as we run under the RTNL lock.
424	 */
425
426	switch (event) {
427	case NETDEV_CHANGE:
428		/* Propagate real device state to vlan devices */
429		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
430			vlandev = vlan_group_get_device(grp, i);
431			if (!vlandev)
432				continue;
433
434			vlan_transfer_operstate(dev, vlandev);
435		}
436		break;
437
438	case NETDEV_CHANGEADDR:
439		/* Adjust unicast filters on underlying device */
440		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
441			vlandev = vlan_group_get_device(grp, i);
442			if (!vlandev)
443				continue;
444
445			flgs = vlandev->flags;
446			if (!(flgs & IFF_UP))
447				continue;
448
449			vlan_sync_address(dev, vlandev);
450		}
451		break;
452
453	case NETDEV_DOWN:
454		/* Put all VLANs for this dev in the down state too.  */
455		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
456			vlandev = vlan_group_get_device(grp, i);
457			if (!vlandev)
458				continue;
459
460			flgs = vlandev->flags;
461			if (!(flgs & IFF_UP))
462				continue;
463
464			dev_change_flags(vlandev, flgs & ~IFF_UP);
465		}
466		break;
467
468	case NETDEV_UP:
469		/* Put all VLANs for this dev in the up state too.  */
470		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
471			vlandev = vlan_group_get_device(grp, i);
472			if (!vlandev)
473				continue;
474
475			flgs = vlandev->flags;
476			if (flgs & IFF_UP)
477				continue;
478
479			dev_change_flags(vlandev, flgs | IFF_UP);
480		}
481		break;
482
483	case NETDEV_UNREGISTER:
484		/* Delete all VLANs for this dev. */
485		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
486			vlandev = vlan_group_get_device(grp, i);
487			if (!vlandev)
488				continue;
489
490			/* unregistration of last vlan destroys group, abort
491			 * afterwards */
492			if (grp->nr_vlans == 1)
493				i = VLAN_GROUP_ARRAY_LEN;
494
495			unregister_vlan_dev(vlandev);
496		}
497		break;
498	}
499
500out:
501	return NOTIFY_DONE;
502}
503
504static struct notifier_block vlan_notifier_block __read_mostly = {
505	.notifier_call = vlan_device_event,
506};
507
508/*
509 *	VLAN IOCTL handler.
510 *	o execute requested action or pass command to the device driver
511 *   arg is really a struct vlan_ioctl_args __user *.
512 */
513static int vlan_ioctl_handler(struct net *net, void __user *arg)
514{
515	int err;
516	unsigned short vid = 0;
517	struct vlan_ioctl_args args;
518	struct net_device *dev = NULL;
519
520	if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
521		return -EFAULT;
522
523	/* Null terminate this sucker, just in case. */
524	args.device1[23] = 0;
525	args.u.device2[23] = 0;
526
527	rtnl_lock();
528
529	switch (args.cmd) {
530	case SET_VLAN_INGRESS_PRIORITY_CMD:
531	case SET_VLAN_EGRESS_PRIORITY_CMD:
532	case SET_VLAN_FLAG_CMD:
533	case ADD_VLAN_CMD:
534	case DEL_VLAN_CMD:
535	case GET_VLAN_REALDEV_NAME_CMD:
536	case GET_VLAN_VID_CMD:
537		err = -ENODEV;
538		dev = __dev_get_by_name(net, args.device1);
539		if (!dev)
540			goto out;
541
542		err = -EINVAL;
543		if (args.cmd != ADD_VLAN_CMD &&
544		    !(dev->priv_flags & IFF_802_1Q_VLAN))
545			goto out;
546	}
547
548	switch (args.cmd) {
549	case SET_VLAN_INGRESS_PRIORITY_CMD:
550		err = -EPERM;
551		if (!capable(CAP_NET_ADMIN))
552			break;
553		vlan_dev_set_ingress_priority(dev,
554					      args.u.skb_priority,
555					      args.vlan_qos);
556		err = 0;
557		break;
558
559	case SET_VLAN_EGRESS_PRIORITY_CMD:
560		err = -EPERM;
561		if (!capable(CAP_NET_ADMIN))
562			break;
563		err = vlan_dev_set_egress_priority(dev,
564						   args.u.skb_priority,
565						   args.vlan_qos);
566		break;
567
568	case SET_VLAN_FLAG_CMD:
569		err = -EPERM;
570		if (!capable(CAP_NET_ADMIN))
571			break;
572		err = vlan_dev_set_vlan_flag(dev,
573					     args.u.flag,
574					     args.vlan_qos);
575		break;
576
577	case SET_VLAN_NAME_TYPE_CMD:
578		err = -EPERM;
579		if (!capable(CAP_NET_ADMIN))
580			break;
581		if ((args.u.name_type >= 0) &&
582		    (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
583			struct vlan_net *vn;
584
585			vn = net_generic(net, vlan_net_id);
586			vn->name_type = args.u.name_type;
587			err = 0;
588		} else {
589			err = -EINVAL;
590		}
591		break;
592
593	case ADD_VLAN_CMD:
594		err = -EPERM;
595		if (!capable(CAP_NET_ADMIN))
596			break;
597		err = register_vlan_device(dev, args.u.VID);
598		break;
599
600	case DEL_VLAN_CMD:
601		err = -EPERM;
602		if (!capable(CAP_NET_ADMIN))
603			break;
604		unregister_vlan_dev(dev);
605		err = 0;
606		break;
607
608	case GET_VLAN_REALDEV_NAME_CMD:
609		err = 0;
610		vlan_dev_get_realdev_name(dev, args.u.device2);
611		if (copy_to_user(arg, &args,
612				 sizeof(struct vlan_ioctl_args)))
613			err = -EFAULT;
614		break;
615
616	case GET_VLAN_VID_CMD:
617		err = 0;
618		vlan_dev_get_vid(dev, &vid);
619		args.u.VID = vid;
620		if (copy_to_user(arg, &args,
621				 sizeof(struct vlan_ioctl_args)))
622		      err = -EFAULT;
623		break;
624
625	default:
626		err = -EOPNOTSUPP;
627		break;
628	}
629out:
630	rtnl_unlock();
631	return err;
632}
633
634static int vlan_init_net(struct net *net)
635{
636	int err;
637	struct vlan_net *vn;
638
639	err = -ENOMEM;
640	vn = kzalloc(sizeof(struct vlan_net), GFP_KERNEL);
641	if (vn == NULL)
642		goto err_alloc;
643
644	err = net_assign_generic(net, vlan_net_id, vn);
645	if (err < 0)
646		goto err_assign;
647
648	vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
649
650	err = vlan_proc_init(net);
651	if (err < 0)
652		goto err_proc;
653
654	return 0;
655
656err_proc:
657	/* nothing */
658err_assign:
659	kfree(vn);
660err_alloc:
661	return err;
662}
663
664static void vlan_exit_net(struct net *net)
665{
666	struct vlan_net *vn;
667
668	vn = net_generic(net, vlan_net_id);
669	rtnl_kill_links(net, &vlan_link_ops);
670	vlan_proc_cleanup(net);
671	kfree(vn);
672}
673
674static struct pernet_operations vlan_net_ops = {
675	.init = vlan_init_net,
676	.exit = vlan_exit_net,
677};
678
679static int __init vlan_proto_init(void)
680{
681	int err;
682
683	pr_info("%s v%s %s\n", vlan_fullname, vlan_version, vlan_copyright);
684	pr_info("All bugs added by %s\n", vlan_buggyright);
685
686	err = register_pernet_gen_device(&vlan_net_id, &vlan_net_ops);
687	if (err < 0)
688		goto err0;
689
690	err = register_netdevice_notifier(&vlan_notifier_block);
691	if (err < 0)
692		goto err2;
693
694	err = vlan_netlink_init();
695	if (err < 0)
696		goto err3;
697
698	dev_add_pack(&vlan_packet_type);
699	vlan_ioctl_set(vlan_ioctl_handler);
700	return 0;
701
702err3:
703	unregister_netdevice_notifier(&vlan_notifier_block);
704err2:
705	unregister_pernet_gen_device(vlan_net_id, &vlan_net_ops);
706err0:
707	return err;
708}
709
710static void __exit vlan_cleanup_module(void)
711{
712	unsigned int i;
713
714	vlan_ioctl_set(NULL);
715	vlan_netlink_fini();
716
717	unregister_netdevice_notifier(&vlan_notifier_block);
718
719	dev_remove_pack(&vlan_packet_type);
720
721	/* This table must be empty if there are no module references left. */
722	for (i = 0; i < VLAN_GRP_HASH_SIZE; i++)
723		BUG_ON(!hlist_empty(&vlan_group_hash[i]));
724
725	unregister_pernet_gen_device(vlan_net_id, &vlan_net_ops);
726
727	synchronize_net();
728}
729
730module_init(vlan_proto_init);
731module_exit(vlan_cleanup_module);
732
733MODULE_LICENSE("GPL");
734MODULE_VERSION(DRV_VERSION);
735