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vlan: Set hard_header_len according to available acceleration
[~andy/linux] / 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
102         netdev_upper_dev_unlink(real_dev, dev);
103         /* Because unregister_netdevice_queue() makes sure at least one rcu
104          * grace period is respected before device freeing,
105          * we dont need to call synchronize_net() here.
106          */
107         unregister_netdevice_queue(dev, head);
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 = register_netdevice(dev);
173         if (err < 0)
174                 goto out_uninit_mvrp;
175
176         err = netdev_upper_dev_link(real_dev, dev);
177         if (err)
178                 goto out_unregister_netdev;
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_unregister_netdev:
195         unregister_netdevice(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 vlan_dev_priv *vlan;
214         struct net *net = dev_net(real_dev);
215         struct vlan_net *vn = net_generic(net, vlan_net_id);
216         char name[IFNAMSIZ];
217         int err;
218
219         if (vlan_id >= VLAN_VID_MASK)
220                 return -ERANGE;
221
222         err = vlan_check_real_dev(real_dev, htons(ETH_P_8021Q), vlan_id);
223         if (err < 0)
224                 return err;
225
226         /* Gotta set up the fields for the device. */
227         switch (vn->name_type) {
228         case VLAN_NAME_TYPE_RAW_PLUS_VID:
229                 /* name will look like:  eth1.0005 */
230                 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, vlan_id);
231                 break;
232         case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
233                 /* Put our vlan.VID in the name.
234                  * Name will look like:  vlan5
235                  */
236                 snprintf(name, IFNAMSIZ, "vlan%i", vlan_id);
237                 break;
238         case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
239                 /* Put our vlan.VID in the name.
240                  * Name will look like:  eth0.5
241                  */
242                 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, vlan_id);
243                 break;
244         case VLAN_NAME_TYPE_PLUS_VID:
245                 /* Put our vlan.VID in the name.
246                  * Name will look like:  vlan0005
247                  */
248         default:
249                 snprintf(name, IFNAMSIZ, "vlan%.4i", vlan_id);
250         }
251
252         new_dev = alloc_netdev(sizeof(struct vlan_dev_priv), name, vlan_setup);
253
254         if (new_dev == NULL)
255                 return -ENOBUFS;
256
257         dev_net_set(new_dev, net);
258         /* need 4 bytes for extra VLAN header info,
259          * hope the underlying device can handle it.
260          */
261         new_dev->mtu = real_dev->mtu;
262         new_dev->priv_flags |= (real_dev->priv_flags & IFF_UNICAST_FLT);
263
264         vlan = vlan_dev_priv(new_dev);
265         vlan->vlan_proto = htons(ETH_P_8021Q);
266         vlan->vlan_id = vlan_id;
267         vlan->real_dev = real_dev;
268         vlan->dent = NULL;
269         vlan->flags = VLAN_FLAG_REORDER_HDR;
270
271         new_dev->rtnl_link_ops = &vlan_link_ops;
272         err = register_vlan_dev(new_dev);
273         if (err < 0)
274                 goto out_free_newdev;
275
276         return 0;
277
278 out_free_newdev:
279         free_netdev(new_dev);
280         return err;
281 }
282
283 static void vlan_sync_address(struct net_device *dev,
284                               struct net_device *vlandev)
285 {
286         struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
287
288         /* May be called without an actual change */
289         if (ether_addr_equal(vlan->real_dev_addr, dev->dev_addr))
290                 return;
291
292         /* vlan address was different from the old address and is equal to
293          * the new address */
294         if (!ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
295             ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
296                 dev_uc_del(dev, vlandev->dev_addr);
297
298         /* vlan address was equal to the old address and is different from
299          * the new address */
300         if (ether_addr_equal(vlandev->dev_addr, vlan->real_dev_addr) &&
301             !ether_addr_equal(vlandev->dev_addr, dev->dev_addr))
302                 dev_uc_add(dev, vlandev->dev_addr);
303
304         ether_addr_copy(vlan->real_dev_addr, dev->dev_addr);
305 }
306
307 static void vlan_transfer_features(struct net_device *dev,
308                                    struct net_device *vlandev)
309 {
310         struct vlan_dev_priv *vlan = vlan_dev_priv(vlandev);
311
312         vlandev->gso_max_size = dev->gso_max_size;
313
314         if (vlan_hw_offload_capable(dev->features, vlan->vlan_proto))
315                 vlandev->hard_header_len = dev->hard_header_len;
316         else
317                 vlandev->hard_header_len = dev->hard_header_len + VLAN_HLEN;
318
319 #if IS_ENABLED(CONFIG_FCOE)
320         vlandev->fcoe_ddp_xid = dev->fcoe_ddp_xid;
321 #endif
322
323         netdev_update_features(vlandev);
324 }
325
326 static void __vlan_device_event(struct net_device *dev, unsigned long event)
327 {
328         switch (event) {
329         case NETDEV_CHANGENAME:
330                 vlan_proc_rem_dev(dev);
331                 if (vlan_proc_add_dev(dev) < 0)
332                         pr_warn("failed to change proc name for %s\n",
333                                 dev->name);
334                 break;
335         case NETDEV_REGISTER:
336                 if (vlan_proc_add_dev(dev) < 0)
337                         pr_warn("failed to add proc entry for %s\n", dev->name);
338                 break;
339         case NETDEV_UNREGISTER:
340                 vlan_proc_rem_dev(dev);
341                 break;
342         }
343 }
344
345 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
346                              void *ptr)
347 {
348         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
349         struct vlan_group *grp;
350         struct vlan_info *vlan_info;
351         int i, flgs;
352         struct net_device *vlandev;
353         struct vlan_dev_priv *vlan;
354         bool last = false;
355         LIST_HEAD(list);
356
357         if (is_vlan_dev(dev))
358                 __vlan_device_event(dev, event);
359
360         if ((event == NETDEV_UP) &&
361             (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)) {
362                 pr_info("adding VLAN 0 to HW filter on device %s\n",
363                         dev->name);
364                 vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
365         }
366
367         vlan_info = rtnl_dereference(dev->vlan_info);
368         if (!vlan_info)
369                 goto out;
370         grp = &vlan_info->grp;
371
372         /* It is OK that we do not hold the group lock right now,
373          * as we run under the RTNL lock.
374          */
375
376         switch (event) {
377         case NETDEV_CHANGE:
378                 /* Propagate real device state to vlan devices */
379                 vlan_group_for_each_dev(grp, i, vlandev)
380                         netif_stacked_transfer_operstate(dev, vlandev);
381                 break;
382
383         case NETDEV_CHANGEADDR:
384                 /* Adjust unicast filters on underlying device */
385                 vlan_group_for_each_dev(grp, i, vlandev) {
386                         flgs = vlandev->flags;
387                         if (!(flgs & IFF_UP))
388                                 continue;
389
390                         vlan_sync_address(dev, vlandev);
391                 }
392                 break;
393
394         case NETDEV_CHANGEMTU:
395                 vlan_group_for_each_dev(grp, i, vlandev) {
396                         if (vlandev->mtu <= dev->mtu)
397                                 continue;
398
399                         dev_set_mtu(vlandev, dev->mtu);
400                 }
401                 break;
402
403         case NETDEV_FEAT_CHANGE:
404                 /* Propagate device features to underlying device */
405                 vlan_group_for_each_dev(grp, i, vlandev)
406                         vlan_transfer_features(dev, vlandev);
407                 break;
408
409         case NETDEV_DOWN:
410                 if (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
411                         vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
412
413                 /* Put all VLANs for this dev in the down state too.  */
414                 vlan_group_for_each_dev(grp, i, vlandev) {
415                         flgs = vlandev->flags;
416                         if (!(flgs & IFF_UP))
417                                 continue;
418
419                         vlan = vlan_dev_priv(vlandev);
420                         if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
421                                 dev_change_flags(vlandev, flgs & ~IFF_UP);
422                         netif_stacked_transfer_operstate(dev, vlandev);
423                 }
424                 break;
425
426         case NETDEV_UP:
427                 /* Put all VLANs for this dev in the up state too.  */
428                 vlan_group_for_each_dev(grp, i, vlandev) {
429                         flgs = vlandev->flags;
430                         if (flgs & IFF_UP)
431                                 continue;
432
433                         vlan = vlan_dev_priv(vlandev);
434                         if (!(vlan->flags & VLAN_FLAG_LOOSE_BINDING))
435                                 dev_change_flags(vlandev, flgs | IFF_UP);
436                         netif_stacked_transfer_operstate(dev, vlandev);
437                 }
438                 break;
439
440         case NETDEV_UNREGISTER:
441                 /* twiddle thumbs on netns device moves */
442                 if (dev->reg_state != NETREG_UNREGISTERING)
443                         break;
444
445                 vlan_group_for_each_dev(grp, i, vlandev) {
446                         /* removal of last vid destroys vlan_info, abort
447                          * afterwards */
448                         if (vlan_info->nr_vids == 1)
449                                 last = true;
450
451                         unregister_vlan_dev(vlandev, &list);
452                         if (last)
453                                 break;
454                 }
455                 unregister_netdevice_many(&list);
456                 break;
457
458         case NETDEV_PRE_TYPE_CHANGE:
459                 /* Forbid underlaying device to change its type. */
460                 if (vlan_uses_dev(dev))
461                         return NOTIFY_BAD;
462                 break;
463
464         case NETDEV_NOTIFY_PEERS:
465         case NETDEV_BONDING_FAILOVER:
466         case NETDEV_RESEND_IGMP:
467                 /* Propagate to vlan devices */
468                 vlan_group_for_each_dev(grp, i, vlandev)
469                         call_netdevice_notifiers(event, vlandev);
470                 break;
471         }
472
473 out:
474         return NOTIFY_DONE;
475 }
476
477 static struct notifier_block vlan_notifier_block __read_mostly = {
478         .notifier_call = vlan_device_event,
479 };
480
481 /*
482  *      VLAN IOCTL handler.
483  *      o execute requested action or pass command to the device driver
484  *   arg is really a struct vlan_ioctl_args __user *.
485  */
486 static int vlan_ioctl_handler(struct net *net, void __user *arg)
487 {
488         int err;
489         struct vlan_ioctl_args args;
490         struct net_device *dev = NULL;
491
492         if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
493                 return -EFAULT;
494
495         /* Null terminate this sucker, just in case. */
496         args.device1[23] = 0;
497         args.u.device2[23] = 0;
498
499         rtnl_lock();
500
501         switch (args.cmd) {
502         case SET_VLAN_INGRESS_PRIORITY_CMD:
503         case SET_VLAN_EGRESS_PRIORITY_CMD:
504         case SET_VLAN_FLAG_CMD:
505         case ADD_VLAN_CMD:
506         case DEL_VLAN_CMD:
507         case GET_VLAN_REALDEV_NAME_CMD:
508         case GET_VLAN_VID_CMD:
509                 err = -ENODEV;
510                 dev = __dev_get_by_name(net, args.device1);
511                 if (!dev)
512                         goto out;
513
514                 err = -EINVAL;
515                 if (args.cmd != ADD_VLAN_CMD && !is_vlan_dev(dev))
516                         goto out;
517         }
518
519         switch (args.cmd) {
520         case SET_VLAN_INGRESS_PRIORITY_CMD:
521                 err = -EPERM;
522                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
523                         break;
524                 vlan_dev_set_ingress_priority(dev,
525                                               args.u.skb_priority,
526                                               args.vlan_qos);
527                 err = 0;
528                 break;
529
530         case SET_VLAN_EGRESS_PRIORITY_CMD:
531                 err = -EPERM;
532                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
533                         break;
534                 err = vlan_dev_set_egress_priority(dev,
535                                                    args.u.skb_priority,
536                                                    args.vlan_qos);
537                 break;
538
539         case SET_VLAN_FLAG_CMD:
540                 err = -EPERM;
541                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
542                         break;
543                 err = vlan_dev_change_flags(dev,
544                                             args.vlan_qos ? args.u.flag : 0,
545                                             args.u.flag);
546                 break;
547
548         case SET_VLAN_NAME_TYPE_CMD:
549                 err = -EPERM;
550                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
551                         break;
552                 if ((args.u.name_type >= 0) &&
553                     (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
554                         struct vlan_net *vn;
555
556                         vn = net_generic(net, vlan_net_id);
557                         vn->name_type = args.u.name_type;
558                         err = 0;
559                 } else {
560                         err = -EINVAL;
561                 }
562                 break;
563
564         case ADD_VLAN_CMD:
565                 err = -EPERM;
566                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
567                         break;
568                 err = register_vlan_device(dev, args.u.VID);
569                 break;
570
571         case DEL_VLAN_CMD:
572                 err = -EPERM;
573                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
574                         break;
575                 unregister_vlan_dev(dev, NULL);
576                 err = 0;
577                 break;
578
579         case GET_VLAN_REALDEV_NAME_CMD:
580                 err = 0;
581                 vlan_dev_get_realdev_name(dev, args.u.device2);
582                 if (copy_to_user(arg, &args,
583                                  sizeof(struct vlan_ioctl_args)))
584                         err = -EFAULT;
585                 break;
586
587         case GET_VLAN_VID_CMD:
588                 err = 0;
589                 args.u.VID = vlan_dev_vlan_id(dev);
590                 if (copy_to_user(arg, &args,
591                                  sizeof(struct vlan_ioctl_args)))
592                       err = -EFAULT;
593                 break;
594
595         default:
596                 err = -EOPNOTSUPP;
597                 break;
598         }
599 out:
600         rtnl_unlock();
601         return err;
602 }
603
604 static int __net_init vlan_init_net(struct net *net)
605 {
606         struct vlan_net *vn = net_generic(net, vlan_net_id);
607         int err;
608
609         vn->name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
610
611         err = vlan_proc_init(net);
612
613         return err;
614 }
615
616 static void __net_exit vlan_exit_net(struct net *net)
617 {
618         vlan_proc_cleanup(net);
619 }
620
621 static struct pernet_operations vlan_net_ops = {
622         .init = vlan_init_net,
623         .exit = vlan_exit_net,
624         .id   = &vlan_net_id,
625         .size = sizeof(struct vlan_net),
626 };
627
628 static int __init vlan_proto_init(void)
629 {
630         int err;
631
632         pr_info("%s v%s\n", vlan_fullname, vlan_version);
633
634         err = register_pernet_subsys(&vlan_net_ops);
635         if (err < 0)
636                 goto err0;
637
638         err = register_netdevice_notifier(&vlan_notifier_block);
639         if (err < 0)
640                 goto err2;
641
642         err = vlan_gvrp_init();
643         if (err < 0)
644                 goto err3;
645
646         err = vlan_mvrp_init();
647         if (err < 0)
648                 goto err4;
649
650         err = vlan_netlink_init();
651         if (err < 0)
652                 goto err5;
653
654         vlan_ioctl_set(vlan_ioctl_handler);
655         return 0;
656
657 err5:
658         vlan_mvrp_uninit();
659 err4:
660         vlan_gvrp_uninit();
661 err3:
662         unregister_netdevice_notifier(&vlan_notifier_block);
663 err2:
664         unregister_pernet_subsys(&vlan_net_ops);
665 err0:
666         return err;
667 }
668
669 static void __exit vlan_cleanup_module(void)
670 {
671         vlan_ioctl_set(NULL);
672         vlan_netlink_fini();
673
674         unregister_netdevice_notifier(&vlan_notifier_block);
675
676         unregister_pernet_subsys(&vlan_net_ops);
677         rcu_barrier(); /* Wait for completion of call_rcu()'s */
678
679         vlan_mvrp_uninit();
680         vlan_gvrp_uninit();
681 }
682
683 module_init(vlan_proto_init);
684 module_exit(vlan_cleanup_module);
685
686 MODULE_LICENSE("GPL");
687 MODULE_VERSION(DRV_VERSION);