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: vlan@scry.wanfear.com
   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/module.h>
  23 #include <linux/netdevice.h>
  24 #include <linux/skbuff.h>
  25 #include <net/datalink.h>
  26 #include <linux/mm.h>
  27 #include <linux/in.h>
  28 #include <linux/init.h>
  29 #include <net/p8022.h>
  30 #include <net/arp.h>
  31 #include <linux/rtnetlink.h>
  32 #include <linux/notifier.h>
  33
  34 #include <linux/if_vlan.h>
  35 #include "vlan.h"
  36 #include "vlanproc.h"
  37
  38 #define DRV_VERSION "1.8"
  39
  40 /* Global VLAN variables */
  41
  42 /* Our listing of VLAN group(s) */
  43 static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
  44 #define vlan_grp_hashfn(IDX)    ((((IDX) >> VLAN_GRP_HASH_SHIFT) ^ (IDX)) & VLAN_GRP_HASH_MASK)
  45
  46 static char vlan_fullname[] = "802.1Q VLAN Support";
  47 static char vlan_version[] = DRV_VERSION;
  48 static char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
  49 static char vlan_buggyright[] = "David S. Miller <davem@redhat.com>";
  50
  51 static int vlan_device_event(struct notifier_block *, unsigned long, void *);
  52 static int vlan_ioctl_handler(void __user *);
  53 static int unregister_vlan_dev(struct net_device *, unsigned short );
  54
  55 static struct notifier_block vlan_notifier_block = {
  56         .notifier_call = vlan_device_event,
  57 };
  58
  59 /* These may be changed at run-time through IOCTLs */
  60
  61 /* Determines interface naming scheme. */
  62 unsigned short vlan_name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
  63
  64 static struct packet_type vlan_packet_type = {
  65         .type = __constant_htons(ETH_P_8021Q),
  66         .func = vlan_skb_recv, /* VLAN receive method */
  67 };
  68
  69 /* Bits of netdev state that are propagated from real device to virtual */
  70 #define VLAN_LINK_STATE_MASK \
  71         ((1<<__LINK_STATE_PRESENT)|(1<<__LINK_STATE_NOCARRIER))
  72
  73 /* End of global variables definitions. */
  74
  75 /*
  76  * Function vlan_proto_init (pro)
  77  *
  78  *    Initialize VLAN protocol layer,
  79  *
  80  */
  81 static int __init vlan_proto_init(void)
  82 {
  83         int err;
  84
  85         printk(VLAN_INF "%s v%s %s\n",
  86                vlan_fullname, vlan_version, vlan_copyright);
  87         printk(VLAN_INF "All bugs added by %s\n",
  88                vlan_buggyright);
  89
  90         /* proc file system initialization */
  91         err = vlan_proc_init();
  92         if (err < 0) {
  93                 printk(KERN_ERR
  94                        "%s %s: can't create entry in proc filesystem!\n",
  95                        __FUNCTION__, VLAN_NAME);
  96                 return err;
  97         }
  98
  99         dev_add_pack(&vlan_packet_type);
 100
 101         /* Register us to receive netdevice events */
 102         err = register_netdevice_notifier(&vlan_notifier_block);
 103         if (err < 0) {
 104                 dev_remove_pack(&vlan_packet_type);
 105                 vlan_proc_cleanup();
 106                 return err;
 107         }
 108
 109         vlan_ioctl_set(vlan_ioctl_handler);
 110
 111         return 0;
 112 }
 113
 114 /* Cleanup all vlan devices
 115  * Note: devices that have been registered that but not
 116  * brought up will exist but have no module ref count.
 117  */
 118 static void __exit vlan_cleanup_devices(void)
 119 {
 120         struct net_device *dev, *nxt;
 121
 122         rtnl_lock();
 123         for (dev = dev_base; dev; dev = nxt) {
 124                 nxt = dev->next;
 125                 if (dev->priv_flags & IFF_802_1Q_VLAN) {
 126                         unregister_vlan_dev(VLAN_DEV_INFO(dev)->real_dev,
 127                                             VLAN_DEV_INFO(dev)->vlan_id);
 128
 129                         unregister_netdevice(dev);
 130                 }
 131         }
 132         rtnl_unlock();
 133 }
 134
 135 /*
 136  *     Module 'remove' entry point.
 137  *     o delete /proc/net/router directory and static entries.
 138  */
 139 static void __exit vlan_cleanup_module(void)
 140 {
 141         int i;
 142
 143         vlan_ioctl_set(NULL);
 144
 145         /* Un-register us from receiving netdevice events */
 146         unregister_netdevice_notifier(&vlan_notifier_block);
 147
 148         dev_remove_pack(&vlan_packet_type);
 149         vlan_cleanup_devices();
 150
 151         /* This table must be empty if there are no module
 152          * references left.
 153          */
 154         for (i = 0; i < VLAN_GRP_HASH_SIZE; i++) {
 155                 BUG_ON(!hlist_empty(&vlan_group_hash[i]));
 156         }
 157         vlan_proc_cleanup();
 158
 159         synchronize_net();
 160 }
 161
 162 module_init(vlan_proto_init);
 163 module_exit(vlan_cleanup_module);
 164
 165 /* Must be invoked with RCU read lock (no preempt) */
 166 static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
 167 {
 168         struct vlan_group *grp;
 169         struct hlist_node *n;
 170         int hash = vlan_grp_hashfn(real_dev_ifindex);
 171
 172         hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
 173                 if (grp->real_dev_ifindex == real_dev_ifindex)
 174                         return grp;
 175         }
 176
 177         return NULL;
 178 }
 179
 180 /*  Find the protocol handler.  Assumes VID < VLAN_VID_MASK.
 181  *
 182  * Must be invoked with RCU read lock (no preempt)
 183  */
 184 struct net_device *__find_vlan_dev(struct net_device *real_dev,
 185                                    unsigned short VID)
 186 {
 187         struct vlan_group *grp = __vlan_find_group(real_dev->ifindex);
 188
 189         if (grp)
 190                 return grp->vlan_devices[VID];
 191
 192         return NULL;
 193 }
 194
 195 static void vlan_rcu_free(struct rcu_head *rcu)
 196 {
 197         kfree(container_of(rcu, struct vlan_group, rcu));
 198 }
 199
 200
 201 /* This returns 0 if everything went fine.
 202  * It will return 1 if the group was killed as a result.
 203  * A negative return indicates failure.
 204  *
 205  * The RTNL lock must be held.
 206  */
 207 static int unregister_vlan_dev(struct net_device *real_dev,
 208                                unsigned short vlan_id)
 209 {
 210         struct net_device *dev = NULL;
 211         int real_dev_ifindex = real_dev->ifindex;
 212         struct vlan_group *grp;
 213         int i, ret;
 214
 215 #ifdef VLAN_DEBUG
 216         printk(VLAN_DBG "%s: VID: %i\n", __FUNCTION__, vlan_id);
 217 #endif
 218
 219         /* sanity check */
 220         if (vlan_id >= VLAN_VID_MASK)
 221                 return -EINVAL;
 222
 223         ASSERT_RTNL();
 224         grp = __vlan_find_group(real_dev_ifindex);
 225
 226         ret = 0;
 227
 228         if (grp) {
 229                 dev = grp->vlan_devices[vlan_id];
 230                 if (dev) {
 231                         /* Remove proc entry */
 232                         vlan_proc_rem_dev(dev);
 233
 234                         /* Take it out of our own structures, but be sure to
 235                          * interlock with HW accelerating devices or SW vlan
 236                          * input packet processing.
 237                          */
 238                         if (real_dev->features &
 239                             (NETIF_F_HW_VLAN_RX | NETIF_F_HW_VLAN_FILTER)) {
 240                                 real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
 241                         }
 242
 243                         grp->vlan_devices[vlan_id] = NULL;
 244                         synchronize_net();
 245
 246
 247                         /* Caller unregisters (and if necessary, puts)
 248                          * VLAN device, but we get rid of the reference to
 249                          * real_dev here.
 250                          */
 251                         dev_put(real_dev);
 252
 253                         /* If the group is now empty, kill off the
 254                          * group.
 255                          */
 256                         for (i = 0; i < VLAN_VID_MASK; i++)
 257                                 if (grp->vlan_devices[i])
 258                                         break;
 259
 260                         if (i == VLAN_VID_MASK) {
 261                                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
 262                                         real_dev->vlan_rx_register(real_dev, NULL);
 263
 264                                 hlist_del_rcu(&grp->hlist);
 265
 266                                 /* Free the group, after all cpu's are done. */
 267                                 call_rcu(&grp->rcu, vlan_rcu_free);
 268
 269                                 grp = NULL;
 270                                 ret = 1;
 271                         }
 272                 }
 273         }
 274
 275         return ret;
 276 }
 277
 278 static int unregister_vlan_device(const char *vlan_IF_name)
 279 {
 280         struct net_device *dev = NULL;
 281         int ret;
 282
 283
 284         dev = dev_get_by_name(vlan_IF_name);
 285         ret = -EINVAL;
 286         if (dev) {
 287                 if (dev->priv_flags & IFF_802_1Q_VLAN) {
 288                         rtnl_lock();
 289
 290                         ret = unregister_vlan_dev(VLAN_DEV_INFO(dev)->real_dev,
 291                                                   VLAN_DEV_INFO(dev)->vlan_id);
 292
 293                         dev_put(dev);
 294                         unregister_netdevice(dev);
 295
 296                         rtnl_unlock();
 297
 298                         if (ret == 1)
 299                                 ret = 0;
 300                 } else {
 301                         printk(VLAN_ERR
 302                                "%s: ERROR:      Tried to remove a non-vlan device "
 303                                "with VLAN code, name: %s  priv_flags: %hX\n",
 304                                __FUNCTION__, dev->name, dev->priv_flags);
 305                         dev_put(dev);
 306                         ret = -EPERM;
 307                 }
 308         } else {
 309 #ifdef VLAN_DEBUG
 310                 printk(VLAN_DBG "%s: WARNING: Could not find dev.\n", __FUNCTION__);
 311 #endif
 312                 ret = -EINVAL;
 313         }
 314
 315         return ret;
 316 }
 317
 318 static void vlan_setup(struct net_device *new_dev)
 319 {
 320         SET_MODULE_OWNER(new_dev);
 321
 322         /* new_dev->ifindex = 0;  it will be set when added to
 323          * the global list.
 324          * iflink is set as well.
 325          */
 326         new_dev->get_stats = vlan_dev_get_stats;
 327
 328         /* Make this thing known as a VLAN device */
 329         new_dev->priv_flags |= IFF_802_1Q_VLAN;
 330
 331         /* Set us up to have no queue, as the underlying Hardware device
 332          * can do all the queueing we could want.
 333          */
 334         new_dev->tx_queue_len = 0;
 335
 336         /* set up method calls */
 337         new_dev->change_mtu = vlan_dev_change_mtu;
 338         new_dev->open = vlan_dev_open;
 339         new_dev->stop = vlan_dev_stop;
 340         new_dev->set_mac_address = vlan_dev_set_mac_address;
 341         new_dev->set_multicast_list = vlan_dev_set_multicast_list;
 342         new_dev->destructor = free_netdev;
 343         new_dev->do_ioctl = vlan_dev_ioctl;
 344 }
 345
 346 /*  Attach a VLAN device to a mac address (ie Ethernet Card).
 347  *  Returns the device that was created, or NULL if there was
 348  *  an error of some kind.
 349  */
 350 static struct net_device *register_vlan_device(const char *eth_IF_name,
 351                                                unsigned short VLAN_ID)
 352 {
 353         struct vlan_group *grp;
 354         struct net_device *new_dev;
 355         struct net_device *real_dev; /* the ethernet device */
 356         char name[IFNAMSIZ];
 357
 358 #ifdef VLAN_DEBUG
 359         printk(VLAN_DBG "%s: if_name -:%s:-     vid: %i\n",
 360                 __FUNCTION__, eth_IF_name, VLAN_ID);
 361 #endif
 362
 363         if (VLAN_ID >= VLAN_VID_MASK)
 364                 goto out_ret_null;
 365
 366         /* find the device relating to eth_IF_name. */
 367         real_dev = dev_get_by_name(eth_IF_name);
 368         if (!real_dev)
 369                 goto out_ret_null;
 370
 371         if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
 372                 printk(VLAN_DBG "%s: VLANs not supported on %s.\n",
 373                         __FUNCTION__, real_dev->name);
 374                 goto out_put_dev;
 375         }
 376
 377         if ((real_dev->features & NETIF_F_HW_VLAN_RX) &&
 378             (real_dev->vlan_rx_register == NULL ||
 379              real_dev->vlan_rx_kill_vid == NULL)) {
 380                 printk(VLAN_DBG "%s: Device %s has buggy VLAN hw accel.\n",
 381                         __FUNCTION__, real_dev->name);
 382                 goto out_put_dev;
 383         }
 384
 385         if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
 386             (real_dev->vlan_rx_add_vid == NULL ||
 387              real_dev->vlan_rx_kill_vid == NULL)) {
 388                 printk(VLAN_DBG "%s: Device %s has buggy VLAN hw accel.\n",
 389                         __FUNCTION__, real_dev->name);
 390                 goto out_put_dev;
 391         }
 392
 393         /* From this point on, all the data structures must remain
 394          * consistent.
 395          */
 396         rtnl_lock();
 397
 398         /* The real device must be up and operating in order to
 399          * assosciate a VLAN device with it.
 400          */
 401         if (!(real_dev->flags & IFF_UP))
 402                 goto out_unlock;
 403
 404         if (__find_vlan_dev(real_dev, VLAN_ID) != NULL) {
 405                 /* was already registered. */
 406                 printk(VLAN_DBG "%s: ALREADY had VLAN registered\n", __FUNCTION__);
 407                 goto out_unlock;
 408         }
 409
 410         /* Gotta set up the fields for the device. */
 411 #ifdef VLAN_DEBUG
 412         printk(VLAN_DBG "About to allocate name, vlan_name_type: %i\n",
 413                vlan_name_type);
 414 #endif
 415         switch (vlan_name_type) {
 416         case VLAN_NAME_TYPE_RAW_PLUS_VID:
 417                 /* name will look like:  eth1.0005 */
 418                 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, VLAN_ID);
 419                 break;
 420         case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
 421                 /* Put our vlan.VID in the name.
 422                  * Name will look like:  vlan5
 423                  */
 424                 snprintf(name, IFNAMSIZ, "vlan%i", VLAN_ID);
 425                 break;
 426         case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
 427                 /* Put our vlan.VID in the name.
 428                  * Name will look like:  eth0.5
 429                  */
 430                 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, VLAN_ID);
 431                 break;
 432         case VLAN_NAME_TYPE_PLUS_VID:
 433                 /* Put our vlan.VID in the name.
 434                  * Name will look like:  vlan0005
 435                  */
 436         default:
 437                 snprintf(name, IFNAMSIZ, "vlan%.4i", VLAN_ID);
 438         };
 439
 440         new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
 441                                vlan_setup);
 442         if (new_dev == NULL)
 443                 goto out_unlock;
 444
 445 #ifdef VLAN_DEBUG
 446         printk(VLAN_DBG "Allocated new name -:%s:-\n", new_dev->name);
 447 #endif
 448         /* IFF_BROADCAST|IFF_MULTICAST; ??? */
 449         new_dev->flags = real_dev->flags;
 450         new_dev->flags &= ~IFF_UP;
 451
 452         new_dev->state = real_dev->state & VLAN_LINK_STATE_MASK;
 453
 454         /* need 4 bytes for extra VLAN header info,
 455          * hope the underlying device can handle it.
 456          */
 457         new_dev->mtu = real_dev->mtu;
 458
 459         /* TODO: maybe just assign it to be ETHERNET? */
 460         new_dev->type = real_dev->type;
 461
 462         new_dev->hard_header_len = real_dev->hard_header_len;
 463         if (!(real_dev->features & NETIF_F_HW_VLAN_TX)) {
 464                 /* Regular ethernet + 4 bytes (18 total). */
 465                 new_dev->hard_header_len += VLAN_HLEN;
 466         }
 467
 468         VLAN_MEM_DBG("new_dev->priv malloc, addr: %p  size: %i\n",
 469                      new_dev->priv,
 470                      sizeof(struct vlan_dev_info));
 471
 472         memcpy(new_dev->broadcast, real_dev->broadcast, real_dev->addr_len);
 473         memcpy(new_dev->dev_addr, real_dev->dev_addr, real_dev->addr_len);
 474         new_dev->addr_len = real_dev->addr_len;
 475
 476         if (real_dev->features & NETIF_F_HW_VLAN_TX) {
 477                 new_dev->hard_header = real_dev->hard_header;
 478                 new_dev->hard_start_xmit = vlan_dev_hwaccel_hard_start_xmit;
 479                 new_dev->rebuild_header = real_dev->rebuild_header;
 480         } else {
 481                 new_dev->hard_header = vlan_dev_hard_header;
 482                 new_dev->hard_start_xmit = vlan_dev_hard_start_xmit;
 483                 new_dev->rebuild_header = vlan_dev_rebuild_header;
 484         }
 485         new_dev->hard_header_parse = real_dev->hard_header_parse;
 486
 487         VLAN_DEV_INFO(new_dev)->vlan_id = VLAN_ID; /* 1 through VLAN_VID_MASK */
 488         VLAN_DEV_INFO(new_dev)->real_dev = real_dev;
 489         VLAN_DEV_INFO(new_dev)->dent = NULL;
 490         VLAN_DEV_INFO(new_dev)->flags = 1;
 491
 492 #ifdef VLAN_DEBUG
 493         printk(VLAN_DBG "About to go find the group for idx: %i\n",
 494                real_dev->ifindex);
 495 #endif
 496
 497         if (register_netdevice(new_dev))
 498                 goto out_free_newdev;
 499
 500         /* So, got the sucker initialized, now lets place
 501          * it into our local structure.
 502          */
 503         grp = __vlan_find_group(real_dev->ifindex);
 504
 505         /* Note, we are running under the RTNL semaphore
 506          * so it cannot "appear" on us.
 507          */
 508         if (!grp) { /* need to add a new group */
 509                 grp = kmalloc(sizeof(struct vlan_group), GFP_KERNEL);
 510                 if (!grp)
 511                         goto out_free_unregister;
 512
 513                 /* printk(KERN_ALERT "VLAN REGISTER:  Allocated new group.\n"); */
 514                 memset(grp, 0, sizeof(struct vlan_group));
 515                 grp->real_dev_ifindex = real_dev->ifindex;
 516
 517                 hlist_add_head_rcu(&grp->hlist,
 518                                    &vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]);
 519
 520                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
 521                         real_dev->vlan_rx_register(real_dev, grp);
 522         }
 523
 524         grp->vlan_devices[VLAN_ID] = new_dev;
 525
 526         if (vlan_proc_add_dev(new_dev)<0)/* create it's proc entry */
 527                 printk(KERN_WARNING "VLAN: failed to add proc entry for %s\n",
 528                                                          new_dev->name);
 529
 530         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
 531                 real_dev->vlan_rx_add_vid(real_dev, VLAN_ID);
 532
 533         rtnl_unlock();
 534
 535
 536 #ifdef VLAN_DEBUG
 537         printk(VLAN_DBG "Allocated new device successfully, returning.\n");
 538 #endif
 539         return new_dev;
 540
 541 out_free_unregister:
 542         unregister_netdev(new_dev);
 543         goto out_unlock;
 544
 545 out_free_newdev:
 546         free_netdev(new_dev);
 547
 548 out_unlock:
 549         rtnl_unlock();
 550
 551 out_put_dev:
 552         dev_put(real_dev);
 553
 554 out_ret_null:
 555         return NULL;
 556 }
 557
 558 static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
 559 {
 560         struct net_device *dev = ptr;
 561         struct vlan_group *grp = __vlan_find_group(dev->ifindex);
 562         int i, flgs;
 563         struct net_device *vlandev;
 564
 565         if (!grp)
 566                 goto out;
 567
 568         /* It is OK that we do not hold the group lock right now,
 569          * as we run under the RTNL lock.
 570          */
 571
 572         switch (event) {
 573         case NETDEV_CHANGE:
 574                 /* Propagate real device state to vlan devices */
 575                 flgs = dev->state & VLAN_LINK_STATE_MASK;
 576                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 577                         vlandev = grp->vlan_devices[i];
 578                         if (!vlandev)
 579                                 continue;
 580
 581                         if ((vlandev->state & VLAN_LINK_STATE_MASK) != flgs) {
 582                                 vlandev->state = (vlandev->state &~ VLAN_LINK_STATE_MASK)
 583                                         | flgs;
 584                                 netdev_state_change(vlandev);
 585                         }
 586                 }
 587                 break;
 588
 589         case NETDEV_DOWN:
 590                 /* Put all VLANs for this dev in the down state too.  */
 591                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 592                         vlandev = grp->vlan_devices[i];
 593                         if (!vlandev)
 594                                 continue;
 595
 596                         flgs = vlandev->flags;
 597                         if (!(flgs & IFF_UP))
 598                                 continue;
 599
 600                         dev_change_flags(vlandev, flgs & ~IFF_UP);
 601                 }
 602                 break;
 603
 604         case NETDEV_UP:
 605                 /* Put all VLANs for this dev in the up state too.  */
 606                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 607                         vlandev = grp->vlan_devices[i];
 608                         if (!vlandev)
 609                                 continue;
 610
 611                         flgs = vlandev->flags;
 612                         if (flgs & IFF_UP)
 613                                 continue;
 614
 615                         dev_change_flags(vlandev, flgs | IFF_UP);
 616                 }
 617                 break;
 618
 619         case NETDEV_UNREGISTER:
 620                 /* Delete all VLANs for this dev. */
 621                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 622                         int ret;
 623
 624                         vlandev = grp->vlan_devices[i];
 625                         if (!vlandev)
 626                                 continue;
 627
 628                         ret = unregister_vlan_dev(dev,
 629                                                   VLAN_DEV_INFO(vlandev)->vlan_id);
 630
 631                         unregister_netdevice(vlandev);
 632
 633                         /* Group was destroyed? */
 634                         if (ret == 1)
 635                                 break;
 636                 }
 637                 break;
 638         };
 639
 640 out:
 641         return NOTIFY_DONE;
 642 }
 643
 644 /*
 645  *      VLAN IOCTL handler.
 646  *      o execute requested action or pass command to the device driver
 647  *   arg is really a struct vlan_ioctl_args __user *.
 648  */
 649 static int vlan_ioctl_handler(void __user *arg)
 650 {
 651         int err = 0;
 652         unsigned short vid = 0;
 653         struct vlan_ioctl_args args;
 654
 655         if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
 656                 return -EFAULT;
 657
 658         /* Null terminate this sucker, just in case. */
 659         args.device1[23] = 0;
 660         args.u.device2[23] = 0;
 661
 662 #ifdef VLAN_DEBUG
 663         printk(VLAN_DBG "%s: args.cmd: %x\n", __FUNCTION__, args.cmd);
 664 #endif
 665
 666         switch (args.cmd) {
 667         case SET_VLAN_INGRESS_PRIORITY_CMD:
 668                 if (!capable(CAP_NET_ADMIN))
 669                         return -EPERM;
 670                 err = vlan_dev_set_ingress_priority(args.device1,
 671                                                     args.u.skb_priority,
 672                                                     args.vlan_qos);
 673                 break;
 674
 675         case SET_VLAN_EGRESS_PRIORITY_CMD:
 676                 if (!capable(CAP_NET_ADMIN))
 677                         return -EPERM;
 678                 err = vlan_dev_set_egress_priority(args.device1,
 679                                                    args.u.skb_priority,
 680                                                    args.vlan_qos);
 681                 break;
 682
 683         case SET_VLAN_FLAG_CMD:
 684                 if (!capable(CAP_NET_ADMIN))
 685                         return -EPERM;
 686                 err = vlan_dev_set_vlan_flag(args.device1,
 687                                              args.u.flag,
 688                                              args.vlan_qos);
 689                 break;
 690
 691         case SET_VLAN_NAME_TYPE_CMD:
 692                 if (!capable(CAP_NET_ADMIN))
 693                         return -EPERM;
 694                 if ((args.u.name_type >= 0) &&
 695                     (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
 696                         vlan_name_type = args.u.name_type;
 697                         err = 0;
 698                 } else {
 699                         err = -EINVAL;
 700                 }
 701                 break;
 702
 703         case ADD_VLAN_CMD:
 704                 if (!capable(CAP_NET_ADMIN))
 705                         return -EPERM;
 706                 /* we have been given the name of the Ethernet Device we want to
 707                  * talk to:  args.dev1   We also have the
 708                  * VLAN ID:  args.u.VID
 709                  */
 710                 if (register_vlan_device(args.device1, args.u.VID)) {
 711                         err = 0;
 712                 } else {
 713                         err = -EINVAL;
 714                 }
 715                 break;
 716
 717         case DEL_VLAN_CMD:
 718                 if (!capable(CAP_NET_ADMIN))
 719                         return -EPERM;
 720                 /* Here, the args.dev1 is the actual VLAN we want
 721                  * to get rid of.
 722                  */
 723                 err = unregister_vlan_device(args.device1);
 724                 break;
 725
 726         case GET_VLAN_INGRESS_PRIORITY_CMD:
 727                 /* TODO:  Implement
 728                    err = vlan_dev_get_ingress_priority(args);
 729                    if (copy_to_user((void*)arg, &args,
 730                         sizeof(struct vlan_ioctl_args))) {
 731                         err = -EFAULT;
 732                    }
 733                 */
 734                 err = -EINVAL;
 735                 break;
 736         case GET_VLAN_EGRESS_PRIORITY_CMD:
 737                 /* TODO:  Implement
 738                    err = vlan_dev_get_egress_priority(args.device1, &(args.args);
 739                    if (copy_to_user((void*)arg, &args,
 740                         sizeof(struct vlan_ioctl_args))) {
 741                         err = -EFAULT;
 742                    }
 743                 */
 744                 err = -EINVAL;
 745                 break;
 746         case GET_VLAN_REALDEV_NAME_CMD:
 747                 err = vlan_dev_get_realdev_name(args.device1, args.u.device2);
 748                 if (copy_to_user(arg, &args,
 749                                  sizeof(struct vlan_ioctl_args))) {
 750                         err = -EFAULT;
 751                 }
 752                 break;
 753
 754         case GET_VLAN_VID_CMD:
 755                 err = vlan_dev_get_vid(args.device1, &vid);
 756                 args.u.VID = vid;
 757                 if (copy_to_user(arg, &args,
 758                                  sizeof(struct vlan_ioctl_args))) {
 759                       err = -EFAULT;
 760                 }
 761                 break;
 762
 763         default:
 764                 /* pass on to underlying device instead?? */
 765                 printk(VLAN_DBG "%s: Unknown VLAN CMD: %x \n",
 766                         __FUNCTION__, args.cmd);
 767                 return -EINVAL;
 768         };
 769
 770         return err;
 771 }
 772
 773 MODULE_LICENSE("GPL");
 774 MODULE_VERSION(DRV_VERSION);