netfilter: invoke synchronize_rcu after set the _hook_ to NULL
[GitHub/mt8127/android_kernel_alcatel_ttab.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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23 #include <linux/capability.h>
24 #include <linux/module.h>
25 #include <linux/netdevice.h>
26 #include <linux/skbuff.h>
27 #include <linux/slab.h>
28 #include <linux/init.h>
29 #include <linux/rculist.h>
30 #include <net/p8022.h>
31 #include <net/arp.h>
32 #include <linux/rtnetlink.h>
33 #include <linux/notifier.h>
34 #include <net/rtnetlink.h>
35 #include <net/net_namespace.h>
36 #include <net/netns/generic.h>
37 #include <asm/uaccess.h>
38
39 #include <linux/if_vlan.h>
40 #include "vlan.h"
41 #include "vlanproc.h"
42
43 #define DRV_VERSION "1.8"
44
45 /* Global VLAN variables */
46
47 int vlan_net_id __read_mostly;
48
49 const char vlan_fullname[] = "802.1Q VLAN Support";
50 const char vlan_version[] = DRV_VERSION;
51
52 /* End of global variables definitions. */
53
54 static int vlan_group_prealloc_vid(struct vlan_group *vg,
55 __be16 vlan_proto, u16 vlan_id)
56 {
57 struct net_device **array;
58 unsigned int pidx, vidx;
59 unsigned int size;
60
61 ASSERT_RTNL();
62
63 pidx = vlan_proto_idx(vlan_proto);
64 vidx = vlan_id / VLAN_GROUP_ARRAY_PART_LEN;
65 array = vg->vlan_devices_arrays[pidx][vidx];
66 if (array != NULL)
67 return 0;
68
69 size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
70 array = kzalloc(size, GFP_KERNEL);
71 if (array == NULL)
72 return -ENOBUFS;
73
74 vg->vlan_devices_arrays[pidx][vidx] = array;
75 return 0;
76 }
77
78 void unregister_vlan_dev(struct net_device *dev, struct list_head *head)
79 {
80 struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
81 struct net_device *real_dev = vlan->real_dev;
82 struct vlan_info *vlan_info;
83 struct vlan_group *grp;
84 u16 vlan_id = vlan->vlan_id;
85
86 ASSERT_RTNL();
87
88 vlan_info = rtnl_dereference(real_dev->vlan_info);
89 BUG_ON(!vlan_info);
90
91 grp = &vlan_info->grp;
92
93 grp->nr_vlan_devs--;
94
95 if (vlan->flags & VLAN_FLAG_MVRP)
96 vlan_mvrp_request_leave(dev);
97 if (vlan->flags & VLAN_FLAG_GVRP)
98 vlan_gvrp_request_leave(dev);
99
100 vlan_group_set_device(grp, vlan->vlan_proto, vlan_id, NULL);
101 /* Because unregister_netdevice_queue() makes sure at least one rcu
102 * grace period is respected before device freeing,
103 * we dont need to call synchronize_net() here.
104 */
105 unregister_netdevice_queue(dev, head);
106
107 netdev_upper_dev_unlink(real_dev, dev);
108
109 if (grp->nr_vlan_devs == 0) {
110 vlan_mvrp_uninit_applicant(real_dev);
111 vlan_gvrp_uninit_applicant(real_dev);
112 }
113
114 /* Take it out of our own structures, but be sure to interlock with
115 * HW accelerating devices or SW vlan input packet processing if
116 * VLAN is not 0 (leave it there for 802.1p).
117 */
118 if (vlan_id)
119 vlan_vid_del(real_dev, vlan->vlan_proto, vlan_id);
120
121 /* Get rid of the vlan's reference to real_dev */
122 dev_put(real_dev);
123 }
124
125 int vlan_check_real_dev(struct net_device *real_dev,
126 __be16 protocol, u16 vlan_id)
127 {
128 const char *name = real_dev->name;
129
130 if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
131 pr_info("VLANs not supported on %s\n", name);
132 return -EOPNOTSUPP;
133 }
134
135 if (vlan_find_dev(real_dev, protocol, vlan_id) != NULL)
136 return -EEXIST;
137
138 return 0;
139 }
140
141 int register_vlan_dev(struct net_device *dev)
142 {
143 struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
144 struct net_device *real_dev = vlan->real_dev;
145 u16 vlan_id = vlan->vlan_id;
146 struct vlan_info *vlan_info;
147 struct vlan_group *grp;
148 int err;
149
150 err = vlan_vid_add(real_dev, vlan->vlan_proto, vlan_id);
151 if (err)
152 return err;
153
154 vlan_info = rtnl_dereference(real_dev->vlan_info);
155 /* vlan_info should be there now. vlan_vid_add took care of it */
156 BUG_ON(!vlan_info);
157
158 grp = &vlan_info->grp;
159 if (grp->nr_vlan_devs == 0) {
160 err = vlan_gvrp_init_applicant(real_dev);
161 if (err < 0)
162 goto out_vid_del;
163 err = vlan_mvrp_init_applicant(real_dev);
164 if (err < 0)
165 goto out_uninit_gvrp;
166 }
167
168 err = vlan_group_prealloc_vid(grp, vlan->vlan_proto, vlan_id);
169 if (err < 0)
170 goto out_uninit_mvrp;
171
172 err = netdev_upper_dev_link(real_dev, dev);
173 if (err)
174 goto out_uninit_mvrp;
175
176 err = register_netdevice(dev);
177 if (err < 0)
178 goto out_upper_dev_unlink;
179
180 /* Account for reference in struct vlan_dev_priv */
181 dev_hold(real_dev);
182
183 netif_stacked_transfer_operstate(real_dev, dev);
184 linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */
185
186 /* So, got the sucker initialized, now lets place
187 * it into our local structure.
188 */
189 vlan_group_set_device(grp, vlan->vlan_proto, vlan_id, dev);
190 grp->nr_vlan_devs++;
191
192 return 0;
193
194 out_upper_dev_unlink:
195 netdev_upper_dev_unlink(real_dev, dev);
196 out_uninit_mvrp:
197 if (grp->nr_vlan_devs == 0)
198 vlan_mvrp_uninit_applicant(real_dev);
199 out_uninit_gvrp:
200 if (grp->nr_vlan_devs == 0)
201 vlan_gvrp_uninit_applicant(real_dev);
202 out_vid_del:
203 vlan_vid_del(real_dev, vlan->vlan_proto, vlan_id);
204 return err;
205 }
206
207 /* Attach a VLAN device to a mac address (ie Ethernet Card).
208 * Returns 0 if the device was created or a negative error code otherwise.
209 */
210 static int register_vlan_device(struct net_device *real_dev, u16 vlan_id)
211 {
212 struct net_device *new_dev;
213 struct net *net = dev_net(real_dev);
214 struct vlan_net *vn = net_generic(net, vlan_net_id);
215 char name[IFNAMSIZ];
216 int err;
217
218 if (vlan_id >= VLAN_VID_MASK)
219 return -ERANGE;
220
221 err = vlan_check_real_dev(real_dev, htons(ETH_P_8021Q), vlan_id);
222 if (err < 0)
223 return err;
224
225 /* Gotta set up the fields for the device. */
226 switch (vn->name_type) {
227 case VLAN_NAME_TYPE_RAW_PLUS_VID:
228 /* name will look like: eth1.0005 */
229 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, vlan_id);
230 break;
231 case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
232 /* Put our vlan.VID in the name.
233 * Name will look like: vlan5
234 */
235 snprintf(name, IFNAMSIZ, "vlan%i", vlan_id);
236 break;
237 case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
238 /* Put our vlan.VID in the name.
239 * Name will look like: eth0.5
240 */
241 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, vlan_id);
242 break;
243 case VLAN_NAME_TYPE_PLUS_VID:
244 /* Put our vlan.VID in the name.
245 * Name will look like: vlan0005
246 */
247 default:
248 snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
249 }
250
251 new_dev = alloc_netdev(sizeof(struct vlan_dev_priv), name, vlan_setup);
252
253 if (new_dev == NULL)
254 return -ENOBUFS;
255
256 dev_net_set(new_dev, net);
257 /* need 4 bytes for extra VLAN header info,
258 * hope the underlying device can handle it.
259 */
260 new_dev->mtu = real_dev->mtu;
261 new_dev->priv_flags |= (real_dev->priv_flags & IFF_UNICAST_FLT);
262
263 vlan_dev_priv(new_dev)->vlan_proto = htons(ETH_P_8021Q);
264 vlan_dev_priv(new_dev)->vlan_id = vlan_id;
265 vlan_dev_priv(new_dev)->real_dev = real_dev;
266 vlan_dev_priv(new_dev)->dent = NULL;
267 vlan_dev_priv(new_dev)->flags = VLAN_FLAG_REORDER_HDR;
268
269 new_dev->rtnl_link_ops = &vlan_link_ops;
270 err = register_vlan_dev(new_dev);
271 if (err < 0)
272 goto out_free_newdev;
273
274 return 0;
275
276 out_free_newdev:
277 free_netdev(new_dev);
278 return err;
279 }
280
281 static void vlan_sync_address(struct net_device *dev,
282 struct net_device *vlandev)
283 {
284 struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
285
286 /* May be called without an actual change */
287 if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
288 return;
289
290 /* vlan address was different from the old address and is equal to
291 * the new address */
292 if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
293 ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
294 dev_uc_del(dev, vlandev->dev_addr);
295
296 /* vlan address was equal to the old address and is different from
297 * the new address */
298 if (ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
299 !ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
300 dev_uc_add(dev, vlandev->dev_addr);
301
302 memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
303 }
304
305 static void vlan_transfer_features(struct net_device *dev,
306 struct net_device *vlandev)
307 {
308 struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
309
310 vlandev->gso_max_size = dev->gso_max_size;
311
312 if (vlan_hw_offload_capable(dev->features, vlan->vlan_proto))
313 vlandev->hard_header_len = dev->hard_header_len;
314 else
315 vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;
316
317 #if IS_ENABLED(CONFIG_FCOE)
318 vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
319 #endif
320
321 netdev_update_features(vlandev);
322 }
323
324 static void __vlan_device_event(struct net_device *dev, unsigned long event)
325 {
326 switch (event) {
327 case NETDEV_CHANGENAME:
328 vlan_proc_rem_dev(dev);
329 if (vlan_proc_add_dev(dev) < 0)
330 pr_warn("failed to change proc name for %s\n",
331 dev->name);
332 break;
333 case NETDEV_REGISTER:
334 if (vlan_proc_add_dev(dev) < 0)
335 pr_warn("failed to add proc entry for %s\n", dev->name);
336 break;
337 case NETDEV_UNREGISTER:
338 vlan_proc_rem_dev(dev);
339 break;
340 }
341 }
342
343 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
344 void *ptr)
345 {
346 struct net_device *dev = ptr;
347 struct vlan_group *grp;
348 struct vlan_info *vlan_info;
349 int i, flgs;
350 struct net_device *vlandev;
351 struct vlan_dev_priv *vlan;
352 bool last = false;
353 LIST_HEAD(list);
354
355 if (is_vlan_dev(dev))
356 __vlan_device_event(dev, event);
357
358 if ((event == NETDEV_UP) &&
359 (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
360 pr_info("adding VLAN 0 to HW filter on device %s\n",
361 dev->name);
362 vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
363 }
364
365 vlan_info = rtnl_dereference(dev->vlan_info);
366 if (!vlan_info)
367 goto out;
368 grp = &vlan_info->grp;
369
370 /* It is OK that we do not hold the group lock right now,
371 * as we run under the RTNL lock.
372 */
373
374 switch (event) {
375 case NETDEV_CHANGE:
376 /* Propagate real device state to vlan devices */
377 vlan_group_for_each_dev(grp, i, vlandev)
378 netif_stacked_transfer_operstate(dev, vlandev);
379 break;
380
381 case NETDEV_CHANGEADDR:
382 /* Adjust unicast filters on underlying device */
383 vlan_group_for_each_dev(grp, i, vlandev) {
384 flgs = vlandev->flags;
385 if (!(flgs & IFF_UP))
386 continue;
387
388 vlan_sync_address(dev, vlandev);
389 }
390 break;
391
392 case NETDEV_CHANGEMTU:
393 vlan_group_for_each_dev(grp, i, vlandev) {
394 if (vlandev->mtu <= dev->mtu)
395 continue;
396
397 dev_set_mtu(vlandev, dev->mtu);
398 }
399 break;
400
401 case NETDEV_FEAT_CHANGE:
402 /* Propagate device features to underlying device */
403 vlan_group_for_each_dev(grp, i, vlandev)
404 vlan_transfer_features(dev, vlandev);
405 break;
406
407 case NETDEV_DOWN:
408 if (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
409 vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
410
411 /* Put all VLANs for this dev in the down state too. */
412 vlan_group_for_each_dev(grp, i, vlandev) {
413 flgs = vlandev->flags;
414 if (!(flgs & IFF_UP))
415 continue;
416
417 vlan = vlan_dev_priv(vlandev);
418 if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
419 dev_change_flags(vlandev, flgs & ~IFF_UP);
420 netif_stacked_transfer_operstate(dev, vlandev);
421 }
422 break;
423
424 case NETDEV_UP:
425 /* Put all VLANs for this dev in the up state too. */
426 vlan_group_for_each_dev(grp, i, vlandev) {
427 flgs = vlandev->flags;
428 if (flgs & IFF_UP)
429 continue;
430
431 vlan = vlan_dev_priv(vlandev);
432 if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
433 dev_change_flags(vlandev, flgs | IFF_UP);
434 netif_stacked_transfer_operstate(dev, vlandev);
435 }
436 break;
437
438 case NETDEV_UNREGISTER:
439 /* twiddle thumbs on netns device moves */
440 if (dev->reg_state != NETREG_UNREGISTERING)
441 break;
442
443 vlan_group_for_each_dev(grp, i, vlandev) {
444 /* removal of last vid destroys vlan_info, abort
445 * afterwards */
446 if (vlan_info->nr_vids == 1)
447 last = true;
448
449 unregister_vlan_dev(vlandev, &list);
450 if (last)
451 break;
452 }
453 unregister_netdevice_many(&list);
454 break;
455
456 case NETDEV_PRE_TYPE_CHANGE:
457 /* Forbid underlaying device to change its type. */
458 if (vlan_uses_dev(dev))
459 return NOTIFY_BAD;
460 break;
461
462 case NETDEV_NOTIFY_PEERS:
463 case NETDEV_BONDING_FAILOVER:
464 /* Propagate to vlan devices */
465 vlan_group_for_each_dev(grp, i, vlandev)
466 call_netdevice_notifiers(event, vlandev);
467 break;
468 }
469
470 out:
471 return NOTIFY_DONE;
472 }
473
474 static struct notifier_block vlan_notifier_block __read_mostly = {
475 .notifier_call = vlan_device_event,
476 };
477
478 /*
479 * VLAN IOCTL handler.
480 * o execute requested action or pass command to the device driver
481 * arg is really a struct vlan_ioctl_args __user *.
482 */
483 static int vlan_ioctl_handler(struct net *net, void __user *arg)
484 {
485 int err;
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(net, args.device1);
508 if (!dev)
509 goto out;
510
511 err = -EINVAL;
512 if (args.cmd != ADD_VLAN_CMD && !is_vlan_dev(dev))
513 goto out;
514 }
515
516 switch (args.cmd) {
517 case SET_VLAN_INGRESS_PRIORITY_CMD:
518 err = -EPERM;
519 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
520 break;
521 vlan_dev_set_ingress_priority(dev,
522 args.u.skb_priority,
523 args.vlan_qos);
524 err = 0;
525 break;
526
527 case SET_VLAN_EGRESS_PRIORITY_CMD:
528 err = -EPERM;
529 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
530 break;
531 err = vlan_dev_set_egress_priority(dev,
532 args.u.skb_priority,
533 args.vlan_qos);
534 break;
535
536 case SET_VLAN_FLAG_CMD:
537 err = -EPERM;
538 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
539 break;
540 err = vlan_dev_change_flags(dev,
541 args.vlan_qos ? args.u.flag : 0,
542 args.u.flag);
543 break;
544
545 case SET_VLAN_NAME_TYPE_CMD:
546 err = -EPERM;
547 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
548 break;
549 if ((args.u.name_type >= 0) &&
550 (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
551 struct vlan_net *vn;
552
553 vn = net_generic(net, vlan_net_id);
554 vn->name_type = args.u.name_type;
555 err = 0;
556 } else {
557 err = -EINVAL;
558 }
559 break;
560
561 case ADD_VLAN_CMD:
562 err = -EPERM;
563 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
564 break;
565 err = register_vlan_device(dev, args.u.VID);
566 break;
567
568 case DEL_VLAN_CMD:
569 err = -EPERM;
570 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
571 break;
572 unregister_vlan_dev(dev, NULL);
573 err = 0;
574 break;
575
576 case GET_VLAN_REALDEV_NAME_CMD:
577 err = 0;
578 vlan_dev_get_realdev_name(dev, args.u.device2);
579 if (copy_to_user(arg, &args,
580 sizeof(struct vlan_ioctl_args)))
581 err = -EFAULT;
582 break;
583
584 case GET_VLAN_VID_CMD:
585 err = 0;
586 args.u.VID = vlan_dev_vlan_id(dev);
587 if (copy_to_user(arg, &args,
588 sizeof(struct vlan_ioctl_args)))
589 err = -EFAULT;
590 break;
591
592 default:
593 err = -EOPNOTSUPP;
594 break;
595 }
596 out:
597 rtnl_unlock();
598 return err;
599 }
600
601 static int __net_init vlan_init_net(struct net *net)
602 {
603 struct vlan_net *vn = net_generic(net, vlan_net_id);
604 int err;
605
606 vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
607
608 err = vlan_proc_init(net);
609
610 return err;
611 }
612
613 static void __net_exit vlan_exit_net(struct net *net)
614 {
615 vlan_proc_cleanup(net);
616 }
617
618 static struct pernet_operations vlan_net_ops = {
619 .init = vlan_init_net,
620 .exit = vlan_exit_net,
621 .id = &vlan_net_id,
622 .size = sizeof(struct vlan_net),
623 };
624
625 static int __init vlan_proto_init(void)
626 {
627 int err;
628
629 pr_info("%s v%s\n", vlan_fullname, vlan_version);
630
631 err = register_pernet_subsys(&vlan_net_ops);
632 if (err < 0)
633 goto err0;
634
635 err = register_netdevice_notifier(&vlan_notifier_block);
636 if (err < 0)
637 goto err2;
638
639 err = vlan_gvrp_init();
640 if (err < 0)
641 goto err3;
642
643 err = vlan_mvrp_init();
644 if (err < 0)
645 goto err4;
646
647 err = vlan_netlink_init();
648 if (err < 0)
649 goto err5;
650
651 vlan_ioctl_set(vlan_ioctl_handler);
652 return 0;
653
654 err5:
655 vlan_mvrp_uninit();
656 err4:
657 vlan_gvrp_uninit();
658 err3:
659 unregister_netdevice_notifier(&vlan_notifier_block);
660 err2:
661 unregister_pernet_subsys(&vlan_net_ops);
662 err0:
663 return err;
664 }
665
666 static void __exit vlan_cleanup_module(void)
667 {
668 vlan_ioctl_set(NULL);
669 vlan_netlink_fini();
670
671 unregister_netdevice_notifier(&vlan_notifier_block);
672
673 unregister_pernet_subsys(&vlan_net_ops);
674 rcu_barrier(); /* Wait for completion of call_rcu()'s */
675
676 vlan_mvrp_uninit();
677 vlan_gvrp_uninit();
678 }
679
680 module_init(vlan_proto_init);
681 module_exit(vlan_cleanup_module);
682
683 MODULE_LICENSE("GPL");
684 MODULE_VERSION(DRV_VERSION);