[VLAN]: sparse warning fix
[linux-2.6.git] / net / 8021q / vlan.c
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
36 #include <linux/if_vlan.h>
37 #include "vlan.h"
38 #include "vlanproc.h"
39
40 #define DRV_VERSION "1.8"
41
42 /* Global VLAN variables */
43
44 /* Our listing of VLAN group(s) */
45 static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
46
47 static char vlan_fullname[] = "802.1Q VLAN Support";
48 static char vlan_version[] = DRV_VERSION;
49 static char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
50 static char vlan_buggyright[] = "David S. Miller <davem@redhat.com>";
51
52 /* Determines interface naming scheme. */
53 unsigned short vlan_name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
54
55 static 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
62 static 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) */
68 static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
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_ifindex == real_dev_ifindex)
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  */
86 struct 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->ifindex);
90
91         if (grp)
92                 return vlan_group_get_device(grp, VID);
93
94         return NULL;
95 }
96
97 static 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
106 static struct vlan_group *vlan_group_alloc(int ifindex)
107 {
108         struct vlan_group *grp;
109         unsigned int size;
110         unsigned int i;
111
112         grp = kzalloc(sizeof(struct vlan_group), GFP_KERNEL);
113         if (!grp)
114                 return NULL;
115
116         size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
117
118         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++) {
119                 grp->vlan_devices_arrays[i] = kzalloc(size, GFP_KERNEL);
120                 if (!grp->vlan_devices_arrays[i])
121                         goto err;
122         }
123
124         grp->real_dev_ifindex = ifindex;
125         hlist_add_head_rcu(&grp->hlist,
126                            &vlan_group_hash[vlan_grp_hashfn(ifindex)]);
127         return grp;
128
129 err:
130         vlan_group_free(grp);
131         return NULL;
132 }
133
134 static void vlan_rcu_free(struct rcu_head *rcu)
135 {
136         vlan_group_free(container_of(rcu, struct vlan_group, rcu));
137 }
138
139 void unregister_vlan_dev(struct net_device *dev)
140 {
141         struct vlan_dev_info *vlan = vlan_dev_info(dev);
142         struct net_device *real_dev = vlan->real_dev;
143         struct vlan_group *grp;
144         unsigned short vlan_id = vlan->vlan_id;
145
146         ASSERT_RTNL();
147
148         grp = __vlan_find_group(real_dev->ifindex);
149         BUG_ON(!grp);
150
151         vlan_proc_rem_dev(dev);
152
153         /* Take it out of our own structures, but be sure to interlock with
154          * HW accelerating devices or SW vlan input packet processing.
155          */
156         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
157                 real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
158
159         vlan_group_set_device(grp, vlan_id, NULL);
160         grp->nr_vlans--;
161
162         synchronize_net();
163
164         /* If the group is now empty, kill off the group. */
165         if (grp->nr_vlans == 0) {
166                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
167                         real_dev->vlan_rx_register(real_dev, NULL);
168
169                 hlist_del_rcu(&grp->hlist);
170
171                 /* Free the group, after all cpu's are done. */
172                 call_rcu(&grp->rcu, vlan_rcu_free);
173         }
174
175         /* Get rid of the vlan's reference to real_dev */
176         dev_put(real_dev);
177
178         unregister_netdevice(dev);
179 }
180
181 static void vlan_transfer_operstate(const struct net_device *dev,
182                                     struct net_device *vlandev)
183 {
184         /* Have to respect userspace enforced dormant state
185          * of real device, also must allow supplicant running
186          * on VLAN device
187          */
188         if (dev->operstate == IF_OPER_DORMANT)
189                 netif_dormant_on(vlandev);
190         else
191                 netif_dormant_off(vlandev);
192
193         if (netif_carrier_ok(dev)) {
194                 if (!netif_carrier_ok(vlandev))
195                         netif_carrier_on(vlandev);
196         } else {
197                 if (netif_carrier_ok(vlandev))
198                         netif_carrier_off(vlandev);
199         }
200 }
201
202 int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id)
203 {
204         char *name = real_dev->name;
205
206         if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
207                 pr_info("8021q: VLANs not supported on %s\n", name);
208                 return -EOPNOTSUPP;
209         }
210
211         if ((real_dev->features & NETIF_F_HW_VLAN_RX) &&
212             !real_dev->vlan_rx_register) {
213                 pr_info("8021q: device %s has buggy VLAN hw accel\n", name);
214                 return -EOPNOTSUPP;
215         }
216
217         if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
218             (!real_dev->vlan_rx_add_vid || !real_dev->vlan_rx_kill_vid)) {
219                 pr_info("8021q: Device %s has buggy VLAN hw accel\n", name);
220                 return -EOPNOTSUPP;
221         }
222
223         /* The real device must be up and operating in order to
224          * assosciate a VLAN device with it.
225          */
226         if (!(real_dev->flags & IFF_UP))
227                 return -ENETDOWN;
228
229         if (__find_vlan_dev(real_dev, vlan_id) != NULL)
230                 return -EEXIST;
231
232         return 0;
233 }
234
235 int register_vlan_dev(struct net_device *dev)
236 {
237         struct vlan_dev_info *vlan = vlan_dev_info(dev);
238         struct net_device *real_dev = vlan->real_dev;
239         unsigned short vlan_id = vlan->vlan_id;
240         struct vlan_group *grp, *ngrp = NULL;
241         int err;
242
243         grp = __vlan_find_group(real_dev->ifindex);
244         if (!grp) {
245                 ngrp = grp = vlan_group_alloc(real_dev->ifindex);
246                 if (!grp)
247                         return -ENOBUFS;
248         }
249
250         err = register_netdevice(dev);
251         if (err < 0)
252                 goto out_free_group;
253
254         /* Account for reference in struct vlan_dev_info */
255         dev_hold(real_dev);
256
257         vlan_transfer_operstate(real_dev, dev);
258         linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */
259
260         /* So, got the sucker initialized, now lets place
261          * it into our local structure.
262          */
263         vlan_group_set_device(grp, vlan_id, dev);
264         grp->nr_vlans++;
265
266         if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX)
267                 real_dev->vlan_rx_register(real_dev, ngrp);
268         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
269                 real_dev->vlan_rx_add_vid(real_dev, vlan_id);
270
271         if (vlan_proc_add_dev(dev) < 0)
272                 pr_warning("8021q: failed to add proc entry for %s\n",
273                            dev->name);
274         return 0;
275
276 out_free_group:
277         if (ngrp)
278                 vlan_group_free(ngrp);
279         return err;
280 }
281
282 /*  Attach a VLAN device to a mac address (ie Ethernet Card).
283  *  Returns 0 if the device was created or a negative error code otherwise.
284  */
285 static int register_vlan_device(struct net_device *real_dev,
286                                 unsigned short VLAN_ID)
287 {
288         struct net_device *new_dev;
289         char name[IFNAMSIZ];
290         int err;
291
292         if (VLAN_ID >= VLAN_VID_MASK)
293                 return -ERANGE;
294
295         err = vlan_check_real_dev(real_dev, VLAN_ID);
296         if (err < 0)
297                 return err;
298
299         /* Gotta set up the fields for the device. */
300         switch (vlan_name_type) {
301         case VLAN_NAME_TYPE_RAW_PLUS_VID:
302                 /* name will look like:  eth1.0005 */
303                 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, VLAN_ID);
304                 break;
305         case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
306                 /* Put our vlan.VID in the name.
307                  * Name will look like:  vlan5
308                  */
309                 snprintf(name, IFNAMSIZ, "vlan%i", VLAN_ID);
310                 break;
311         case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
312                 /* Put our vlan.VID in the name.
313                  * Name will look like:  eth0.5
314                  */
315                 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, VLAN_ID);
316                 break;
317         case VLAN_NAME_TYPE_PLUS_VID:
318                 /* Put our vlan.VID in the name.
319                  * Name will look like:  vlan0005
320                  */
321         default:
322                 snprintf(name, IFNAMSIZ, "vlan%.4i", VLAN_ID);
323         }
324
325         new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
326                                vlan_setup);
327
328         if (new_dev == NULL)
329                 return -ENOBUFS;
330
331         /* need 4 bytes for extra VLAN header info,
332          * hope the underlying device can handle it.
333          */
334         new_dev->mtu = real_dev->mtu;
335
336         vlan_dev_info(new_dev)->vlan_id = VLAN_ID; /* 1 through VLAN_VID_MASK */
337         vlan_dev_info(new_dev)->real_dev = real_dev;
338         vlan_dev_info(new_dev)->dent = NULL;
339         vlan_dev_info(new_dev)->flags = VLAN_FLAG_REORDER_HDR;
340
341         new_dev->rtnl_link_ops = &vlan_link_ops;
342         err = register_vlan_dev(new_dev);
343         if (err < 0)
344                 goto out_free_newdev;
345
346         return 0;
347
348 out_free_newdev:
349         free_netdev(new_dev);
350         return err;
351 }
352
353 static void vlan_sync_address(struct net_device *dev,
354                               struct net_device *vlandev)
355 {
356         struct vlan_dev_info *vlan = vlan_dev_info(vlandev);
357
358         /* May be called without an actual change */
359         if (!compare_ether_addr(vlan->real_dev_addr, dev->dev_addr))
360                 return;
361
362         /* vlan address was different from the old address and is equal to
363          * the new address */
364         if (compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
365             !compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
366                 dev_unicast_delete(dev, vlandev->dev_addr, ETH_ALEN);
367
368         /* vlan address was equal to the old address and is different from
369          * the new address */
370         if (!compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
371             compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
372                 dev_unicast_add(dev, vlandev->dev_addr, ETH_ALEN);
373
374         memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
375 }
376
377 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
378                              void *ptr)
379 {
380         struct net_device *dev = ptr;
381         struct vlan_group *grp = __vlan_find_group(dev->ifindex);
382         int i, flgs;
383         struct net_device *vlandev;
384
385         if (dev->nd_net != &init_net)
386                 return NOTIFY_DONE;
387
388         if (!grp)
389                 goto out;
390
391         /* It is OK that we do not hold the group lock right now,
392          * as we run under the RTNL lock.
393          */
394
395         switch (event) {
396         case NETDEV_CHANGE:
397                 /* Propagate real device state to vlan devices */
398                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
399                         vlandev = vlan_group_get_device(grp, i);
400                         if (!vlandev)
401                                 continue;
402
403                         vlan_transfer_operstate(dev, vlandev);
404                 }
405                 break;
406
407         case NETDEV_CHANGEADDR:
408                 /* Adjust unicast filters on underlying device */
409                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
410                         vlandev = vlan_group_get_device(grp, i);
411                         if (!vlandev)
412                                 continue;
413
414                         flgs = vlandev->flags;
415                         if (!(flgs & IFF_UP))
416                                 continue;
417
418                         vlan_sync_address(dev, vlandev);
419                 }
420                 break;
421
422         case NETDEV_DOWN:
423                 /* Put all VLANs for this dev in the down state too.  */
424                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
425                         vlandev = vlan_group_get_device(grp, i);
426                         if (!vlandev)
427                                 continue;
428
429                         flgs = vlandev->flags;
430                         if (!(flgs & IFF_UP))
431                                 continue;
432
433                         dev_change_flags(vlandev, flgs & ~IFF_UP);
434                 }
435                 break;
436
437         case NETDEV_UP:
438                 /* Put all VLANs for this dev in the up state too.  */
439                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
440                         vlandev = vlan_group_get_device(grp, i);
441                         if (!vlandev)
442                                 continue;
443
444                         flgs = vlandev->flags;
445                         if (flgs & IFF_UP)
446                                 continue;
447
448                         dev_change_flags(vlandev, flgs | IFF_UP);
449                 }
450                 break;
451
452         case NETDEV_UNREGISTER:
453                 /* Delete all VLANs for this dev. */
454                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
455                         vlandev = vlan_group_get_device(grp, i);
456                         if (!vlandev)
457                                 continue;
458
459                         /* unregistration of last vlan destroys group, abort
460                          * afterwards */
461                         if (grp->nr_vlans == 1)
462                                 i = VLAN_GROUP_ARRAY_LEN;
463
464                         unregister_vlan_dev(vlandev);
465                 }
466                 break;
467         }
468
469 out:
470         return NOTIFY_DONE;
471 }
472
473 static struct notifier_block vlan_notifier_block __read_mostly = {
474         .notifier_call = vlan_device_event,
475 };
476
477 /*
478  *      VLAN IOCTL handler.
479  *      o execute requested action or pass command to the device driver
480  *   arg is really a struct vlan_ioctl_args __user *.
481  */
482 static int vlan_ioctl_handler(struct net *net, void __user *arg)
483 {
484         int err;
485         unsigned short vid = 0;
486         struct vlan_ioctl_args args;
487         struct net_device *dev = NULL;
488
489         if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
490                 return -EFAULT;
491
492         /* Null terminate this sucker, just in case. */
493         args.device1[23] = 0;
494         args.u.device2[23] = 0;
495
496         rtnl_lock();
497
498         switch (args.cmd) {
499         case SET_VLAN_INGRESS_PRIORITY_CMD:
500         case SET_VLAN_EGRESS_PRIORITY_CMD:
501         case SET_VLAN_FLAG_CMD:
502         case ADD_VLAN_CMD:
503         case DEL_VLAN_CMD:
504         case GET_VLAN_REALDEV_NAME_CMD:
505         case GET_VLAN_VID_CMD:
506                 err = -ENODEV;
507                 dev = __dev_get_by_name(&init_net, args.device1);
508                 if (!dev)
509                         goto out;
510
511                 err = -EINVAL;
512                 if (args.cmd != ADD_VLAN_CMD &&
513                     !(dev->priv_flags & IFF_802_1Q_VLAN))
514                         goto out;
515         }
516
517         switch (args.cmd) {
518         case SET_VLAN_INGRESS_PRIORITY_CMD:
519                 err = -EPERM;
520                 if (!capable(CAP_NET_ADMIN))
521                         break;
522                 vlan_dev_set_ingress_priority(dev,
523                                               args.u.skb_priority,
524                                               args.vlan_qos);
525                 err = 0;
526                 break;
527
528         case SET_VLAN_EGRESS_PRIORITY_CMD:
529                 err = -EPERM;
530                 if (!capable(CAP_NET_ADMIN))
531                         break;
532                 err = vlan_dev_set_egress_priority(dev,
533                                                    args.u.skb_priority,
534                                                    args.vlan_qos);
535                 break;
536
537         case SET_VLAN_FLAG_CMD:
538                 err = -EPERM;
539                 if (!capable(CAP_NET_ADMIN))
540                         break;
541                 err = vlan_dev_set_vlan_flag(dev,
542                                              args.u.flag,
543                                              args.vlan_qos);
544                 break;
545
546         case SET_VLAN_NAME_TYPE_CMD:
547                 err = -EPERM;
548                 if (!capable(CAP_NET_ADMIN))
549                         break;
550                 if ((args.u.name_type >= 0) &&
551                     (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
552                         vlan_name_type = args.u.name_type;
553                         err = 0;
554                 } else {
555                         err = -EINVAL;
556                 }
557                 break;
558
559         case ADD_VLAN_CMD:
560                 err = -EPERM;
561                 if (!capable(CAP_NET_ADMIN))
562                         break;
563                 err = register_vlan_device(dev, args.u.VID);
564                 break;
565
566         case DEL_VLAN_CMD:
567                 err = -EPERM;
568                 if (!capable(CAP_NET_ADMIN))
569                         break;
570                 unregister_vlan_dev(dev);
571                 err = 0;
572                 break;
573
574         case GET_VLAN_REALDEV_NAME_CMD:
575                 err = 0;
576                 vlan_dev_get_realdev_name(dev, args.u.device2);
577                 if (copy_to_user(arg, &args,
578                                  sizeof(struct vlan_ioctl_args)))
579                         err = -EFAULT;
580                 break;
581
582         case GET_VLAN_VID_CMD:
583                 err = 0;
584                 vlan_dev_get_vid(dev, &vid);
585                 args.u.VID = vid;
586                 if (copy_to_user(arg, &args,
587                                  sizeof(struct vlan_ioctl_args)))
588                       err = -EFAULT;
589                 break;
590
591         default:
592                 err = -EOPNOTSUPP;
593                 break;
594         }
595 out:
596         rtnl_unlock();
597         return err;
598 }
599
600 static int __init vlan_proto_init(void)
601 {
602         int err;
603
604         pr_info("%s v%s %s\n", vlan_fullname, vlan_version, vlan_copyright);
605         pr_info("All bugs added by %s\n", vlan_buggyright);
606
607         err = vlan_proc_init();
608         if (err < 0)
609                 goto err1;
610
611         err = register_netdevice_notifier(&vlan_notifier_block);
612         if (err < 0)
613                 goto err2;
614
615         err = vlan_netlink_init();
616         if (err < 0)
617                 goto err3;
618
619         dev_add_pack(&vlan_packet_type);
620         vlan_ioctl_set(vlan_ioctl_handler);
621         return 0;
622
623 err3:
624         unregister_netdevice_notifier(&vlan_notifier_block);
625 err2:
626         vlan_proc_cleanup();
627 err1:
628         return err;
629 }
630
631 static void __exit vlan_cleanup_module(void)
632 {
633         unsigned int i;
634
635         vlan_ioctl_set(NULL);
636         vlan_netlink_fini();
637
638         unregister_netdevice_notifier(&vlan_notifier_block);
639
640         dev_remove_pack(&vlan_packet_type);
641
642         /* This table must be empty if there are no module references left. */
643         for (i = 0; i < VLAN_GRP_HASH_SIZE; i++)
644                 BUG_ON(!hlist_empty(&vlan_group_hash[i]));
645
646         vlan_proc_cleanup();
647
648         synchronize_net();
649 }
650
651 module_init(vlan_proto_init);
652 module_exit(vlan_cleanup_module);
653
654 MODULE_LICENSE("GPL");
655 MODULE_VERSION(DRV_VERSION);