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/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 #define vlan_grp_hashfn(IDX)    ((((IDX) >> VLAN_GRP_HASH_SHIFT) ^ (IDX)) & VLAN_GRP_HASH_MASK)
  47
  48 static char vlan_fullname[] = "802.1Q VLAN Support";
  49 static char vlan_version[] = DRV_VERSION;
  50 static char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
  51 static char vlan_buggyright[] = "David S. Miller <davem@redhat.com>";
  52
  53 /* Determines interface naming scheme. */
  54 unsigned short vlan_name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
  55
  56 static struct packet_type vlan_packet_type = {
  57         .type = __constant_htons(ETH_P_8021Q),
  58         .func = vlan_skb_recv, /* VLAN receive method */
  59 };
  60
  61 /* End of global variables definitions. */
  62
  63 /* Must be invoked with RCU read lock (no preempt) */
  64 static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
  65 {
  66         struct vlan_group *grp;
  67         struct hlist_node *n;
  68         int hash = vlan_grp_hashfn(real_dev_ifindex);
  69
  70         hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
  71                 if (grp->real_dev_ifindex == real_dev_ifindex)
  72                         return grp;
  73         }
  74
  75         return NULL;
  76 }
  77
  78 /*  Find the protocol handler.  Assumes VID < VLAN_VID_MASK.
  79  *
  80  * Must be invoked with RCU read lock (no preempt)
  81  */
  82 struct net_device *__find_vlan_dev(struct net_device *real_dev,
  83                                    unsigned short VID)
  84 {
  85         struct vlan_group *grp = __vlan_find_group(real_dev->ifindex);
  86
  87         if (grp)
  88                 return vlan_group_get_device(grp, VID);
  89
  90         return NULL;
  91 }
  92
  93 static void vlan_group_free(struct vlan_group *grp)
  94 {
  95         int i;
  96
  97         for (i=0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
  98                 kfree(grp->vlan_devices_arrays[i]);
  99         kfree(grp);
 100 }
 101
 102 static struct vlan_group *vlan_group_alloc(int ifindex)
 103 {
 104         struct vlan_group *grp;
 105         unsigned int size;
 106         unsigned int i;
 107
 108         grp = kzalloc(sizeof(struct vlan_group), GFP_KERNEL);
 109         if (!grp)
 110                 return NULL;
 111
 112         size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
 113
 114         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++) {
 115                 grp->vlan_devices_arrays[i] = kzalloc(size, GFP_KERNEL);
 116                 if (!grp->vlan_devices_arrays[i])
 117                         goto err;
 118         }
 119
 120         grp->real_dev_ifindex = ifindex;
 121         hlist_add_head_rcu(&grp->hlist,
 122                            &vlan_group_hash[vlan_grp_hashfn(ifindex)]);
 123         return grp;
 124
 125 err:
 126         vlan_group_free(grp);
 127         return NULL;
 128 }
 129
 130 static void vlan_rcu_free(struct rcu_head *rcu)
 131 {
 132         vlan_group_free(container_of(rcu, struct vlan_group, rcu));
 133 }
 134
 135 void unregister_vlan_dev(struct net_device *dev)
 136 {
 137         struct vlan_dev_info *vlan = vlan_dev_info(dev);
 138         struct net_device *real_dev = vlan->real_dev;
 139         struct vlan_group *grp;
 140         unsigned short vlan_id = vlan->vlan_id;
 141
 142         ASSERT_RTNL();
 143
 144         grp = __vlan_find_group(real_dev->ifindex);
 145         BUG_ON(!grp);
 146
 147         vlan_proc_rem_dev(dev);
 148
 149         /* Take it out of our own structures, but be sure to interlock with
 150          * HW accelerating devices or SW vlan input packet processing.
 151          */
 152         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
 153                 real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
 154
 155         vlan_group_set_device(grp, vlan_id, NULL);
 156         grp->nr_vlans--;
 157
 158         synchronize_net();
 159
 160         /* If the group is now empty, kill off the group. */
 161         if (grp->nr_vlans == 0) {
 162                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
 163                         real_dev->vlan_rx_register(real_dev, NULL);
 164
 165                 hlist_del_rcu(&grp->hlist);
 166
 167                 /* Free the group, after all cpu's are done. */
 168                 call_rcu(&grp->rcu, vlan_rcu_free);
 169         }
 170
 171         /* Get rid of the vlan's reference to real_dev */
 172         dev_put(real_dev);
 173
 174         unregister_netdevice(dev);
 175 }
 176
 177 static void vlan_transfer_operstate(const struct net_device *dev, struct net_device *vlandev)
 178 {
 179         /* Have to respect userspace enforced dormant state
 180          * of real device, also must allow supplicant running
 181          * on VLAN device
 182          */
 183         if (dev->operstate == IF_OPER_DORMANT)
 184                 netif_dormant_on(vlandev);
 185         else
 186                 netif_dormant_off(vlandev);
 187
 188         if (netif_carrier_ok(dev)) {
 189                 if (!netif_carrier_ok(vlandev))
 190                         netif_carrier_on(vlandev);
 191         } else {
 192                 if (netif_carrier_ok(vlandev))
 193                         netif_carrier_off(vlandev);
 194         }
 195 }
 196
 197 int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id)
 198 {
 199         char *name = real_dev->name;
 200
 201         if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
 202                 pr_info("8021q: VLANs not supported on %s\n", name);
 203                 return -EOPNOTSUPP;
 204         }
 205
 206         if ((real_dev->features & NETIF_F_HW_VLAN_RX) &&
 207             !real_dev->vlan_rx_register) {
 208                 pr_info("8021q: device %s has buggy VLAN hw accel\n", name);
 209                 return -EOPNOTSUPP;
 210         }
 211
 212         if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
 213             (!real_dev->vlan_rx_add_vid || !real_dev->vlan_rx_kill_vid)) {
 214                 pr_info("8021q: Device %s has buggy VLAN hw accel\n", name);
 215                 return -EOPNOTSUPP;
 216         }
 217
 218         /* The real device must be up and operating in order to
 219          * assosciate a VLAN device with it.
 220          */
 221         if (!(real_dev->flags & IFF_UP))
 222                 return -ENETDOWN;
 223
 224         if (__find_vlan_dev(real_dev, vlan_id) != NULL)
 225                 return -EEXIST;
 226
 227         return 0;
 228 }
 229
 230 int register_vlan_dev(struct net_device *dev)
 231 {
 232         struct vlan_dev_info *vlan = vlan_dev_info(dev);
 233         struct net_device *real_dev = vlan->real_dev;
 234         unsigned short vlan_id = vlan->vlan_id;
 235         struct vlan_group *grp, *ngrp = NULL;
 236         int err;
 237
 238         grp = __vlan_find_group(real_dev->ifindex);
 239         if (!grp) {
 240                 ngrp = grp = vlan_group_alloc(real_dev->ifindex);
 241                 if (!grp)
 242                         return -ENOBUFS;
 243         }
 244
 245         err = register_netdevice(dev);
 246         if (err < 0)
 247                 goto out_free_group;
 248
 249         /* Account for reference in struct vlan_dev_info */
 250         dev_hold(real_dev);
 251
 252         vlan_transfer_operstate(real_dev, dev);
 253         linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */
 254
 255         /* So, got the sucker initialized, now lets place
 256          * it into our local structure.
 257          */
 258         vlan_group_set_device(grp, vlan_id, dev);
 259         grp->nr_vlans++;
 260
 261         if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX)
 262                 real_dev->vlan_rx_register(real_dev, ngrp);
 263         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
 264                 real_dev->vlan_rx_add_vid(real_dev, vlan_id);
 265
 266         if (vlan_proc_add_dev(dev) < 0)
 267                 pr_warning("8021q: failed to add proc entry for %s\n",
 268                            dev->name);
 269         return 0;
 270
 271 out_free_group:
 272         if (ngrp)
 273                 vlan_group_free(ngrp);
 274         return err;
 275 }
 276
 277 /*  Attach a VLAN device to a mac address (ie Ethernet Card).
 278  *  Returns 0 if the device was created or a negative error code otherwise.
 279  */
 280 static int register_vlan_device(struct net_device *real_dev,
 281                                 unsigned short VLAN_ID)
 282 {
 283         struct net_device *new_dev;
 284         char name[IFNAMSIZ];
 285         int err;
 286
 287         if (VLAN_ID >= VLAN_VID_MASK)
 288                 return -ERANGE;
 289
 290         err = vlan_check_real_dev(real_dev, VLAN_ID);
 291         if (err < 0)
 292                 return err;
 293
 294         /* Gotta set up the fields for the device. */
 295         switch (vlan_name_type) {
 296         case VLAN_NAME_TYPE_RAW_PLUS_VID:
 297                 /* name will look like:  eth1.0005 */
 298                 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, VLAN_ID);
 299                 break;
 300         case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
 301                 /* Put our vlan.VID in the name.
 302                  * Name will look like:  vlan5
 303                  */
 304                 snprintf(name, IFNAMSIZ, "vlan%i", VLAN_ID);
 305                 break;
 306         case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
 307                 /* Put our vlan.VID in the name.
 308                  * Name will look like:  eth0.5
 309                  */
 310                 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, VLAN_ID);
 311                 break;
 312         case VLAN_NAME_TYPE_PLUS_VID:
 313                 /* Put our vlan.VID in the name.
 314                  * Name will look like:  vlan0005
 315                  */
 316         default:
 317                 snprintf(name, IFNAMSIZ, "vlan%.4i", VLAN_ID);
 318         }
 319
 320         new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
 321                                vlan_setup);
 322
 323         if (new_dev == NULL)
 324                 return -ENOBUFS;
 325
 326         /* need 4 bytes for extra VLAN header info,
 327          * hope the underlying device can handle it.
 328          */
 329         new_dev->mtu = real_dev->mtu;
 330
 331         vlan_dev_info(new_dev)->vlan_id = VLAN_ID; /* 1 through VLAN_VID_MASK */
 332         vlan_dev_info(new_dev)->real_dev = real_dev;
 333         vlan_dev_info(new_dev)->dent = NULL;
 334         vlan_dev_info(new_dev)->flags = VLAN_FLAG_REORDER_HDR;
 335
 336         new_dev->rtnl_link_ops = &vlan_link_ops;
 337         err = register_vlan_dev(new_dev);
 338         if (err < 0)
 339                 goto out_free_newdev;
 340
 341         return 0;
 342
 343 out_free_newdev:
 344         free_netdev(new_dev);
 345         return err;
 346 }
 347
 348 static void vlan_sync_address(struct net_device *dev,
 349                               struct net_device *vlandev)
 350 {
 351         struct vlan_dev_info *vlan = vlan_dev_info(vlandev);
 352
 353         /* May be called without an actual change */
 354         if (!compare_ether_addr(vlan->real_dev_addr, dev->dev_addr))
 355                 return;
 356
 357         /* vlan address was different from the old address and is equal to
 358          * the new address */
 359         if (compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
 360             !compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
 361                 dev_unicast_delete(dev, vlandev->dev_addr, ETH_ALEN);
 362
 363         /* vlan address was equal to the old address and is different from
 364          * the new address */
 365         if (!compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
 366             compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
 367                 dev_unicast_add(dev, vlandev->dev_addr, ETH_ALEN);
 368
 369         memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
 370 }
 371
 372 static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
 373 {
 374         struct net_device *dev = ptr;
 375         struct vlan_group *grp = __vlan_find_group(dev->ifindex);
 376         int i, flgs;
 377         struct net_device *vlandev;
 378
 379         if (dev->nd_net != &init_net)
 380                 return NOTIFY_DONE;
 381
 382         if (!grp)
 383                 goto out;
 384
 385         /* It is OK that we do not hold the group lock right now,
 386          * as we run under the RTNL lock.
 387          */
 388
 389         switch (event) {
 390         case NETDEV_CHANGE:
 391                 /* Propagate real device state to vlan devices */
 392                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 393                         vlandev = vlan_group_get_device(grp, i);
 394                         if (!vlandev)
 395                                 continue;
 396
 397                         vlan_transfer_operstate(dev, vlandev);
 398                 }
 399                 break;
 400
 401         case NETDEV_CHANGEADDR:
 402                 /* Adjust unicast filters on underlying device */
 403                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 404                         vlandev = vlan_group_get_device(grp, i);
 405                         if (!vlandev)
 406                                 continue;
 407
 408                         flgs = vlandev->flags;
 409                         if (!(flgs & IFF_UP))
 410                                 continue;
 411
 412                         vlan_sync_address(dev, vlandev);
 413                 }
 414                 break;
 415
 416         case NETDEV_DOWN:
 417                 /* Put all VLANs for this dev in the down state too.  */
 418                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 419                         vlandev = vlan_group_get_device(grp, i);
 420                         if (!vlandev)
 421                                 continue;
 422
 423                         flgs = vlandev->flags;
 424                         if (!(flgs & IFF_UP))
 425                                 continue;
 426
 427                         dev_change_flags(vlandev, flgs & ~IFF_UP);
 428                 }
 429                 break;
 430
 431         case NETDEV_UP:
 432                 /* Put all VLANs for this dev in the up state too.  */
 433                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 434                         vlandev = vlan_group_get_device(grp, i);
 435                         if (!vlandev)
 436                                 continue;
 437
 438                         flgs = vlandev->flags;
 439                         if (flgs & IFF_UP)
 440                                 continue;
 441
 442                         dev_change_flags(vlandev, flgs | IFF_UP);
 443                 }
 444                 break;
 445
 446         case NETDEV_UNREGISTER:
 447                 /* Delete all VLANs for this dev. */
 448                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 449                         vlandev = vlan_group_get_device(grp, i);
 450                         if (!vlandev)
 451                                 continue;
 452
 453                         /* unregistration of last vlan destroys group, abort
 454                          * afterwards */
 455                         if (grp->nr_vlans == 1)
 456                                 i = VLAN_GROUP_ARRAY_LEN;
 457
 458                         unregister_vlan_dev(vlandev);
 459                 }
 460                 break;
 461         }
 462
 463 out:
 464         return NOTIFY_DONE;
 465 }
 466
 467 static struct notifier_block vlan_notifier_block __read_mostly = {
 468         .notifier_call = vlan_device_event,
 469 };
 470
 471 /*
 472  *      VLAN IOCTL handler.
 473  *      o execute requested action or pass command to the device driver
 474  *   arg is really a struct vlan_ioctl_args __user *.
 475  */
 476 static int vlan_ioctl_handler(struct net *net, void __user *arg)
 477 {
 478         int err;
 479         unsigned short vid = 0;
 480         struct vlan_ioctl_args args;
 481         struct net_device *dev = NULL;
 482
 483         if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
 484                 return -EFAULT;
 485
 486         /* Null terminate this sucker, just in case. */
 487         args.device1[23] = 0;
 488         args.u.device2[23] = 0;
 489
 490         rtnl_lock();
 491
 492         switch (args.cmd) {
 493         case SET_VLAN_INGRESS_PRIORITY_CMD:
 494         case SET_VLAN_EGRESS_PRIORITY_CMD:
 495         case SET_VLAN_FLAG_CMD:
 496         case ADD_VLAN_CMD:
 497         case DEL_VLAN_CMD:
 498         case GET_VLAN_REALDEV_NAME_CMD:
 499         case GET_VLAN_VID_CMD:
 500                 err = -ENODEV;
 501                 dev = __dev_get_by_name(&init_net, args.device1);
 502                 if (!dev)
 503                         goto out;
 504
 505                 err = -EINVAL;
 506                 if (args.cmd != ADD_VLAN_CMD &&
 507                     !(dev->priv_flags & IFF_802_1Q_VLAN))
 508                         goto out;
 509         }
 510
 511         switch (args.cmd) {
 512         case SET_VLAN_INGRESS_PRIORITY_CMD:
 513                 err = -EPERM;
 514                 if (!capable(CAP_NET_ADMIN))
 515                         break;
 516                 vlan_dev_set_ingress_priority(dev,
 517                                               args.u.skb_priority,
 518                                               args.vlan_qos);
 519                 err = 0;
 520                 break;
 521
 522         case SET_VLAN_EGRESS_PRIORITY_CMD:
 523                 err = -EPERM;
 524                 if (!capable(CAP_NET_ADMIN))
 525                         break;
 526                 err = vlan_dev_set_egress_priority(dev,
 527                                                    args.u.skb_priority,
 528                                                    args.vlan_qos);
 529                 break;
 530
 531         case SET_VLAN_FLAG_CMD:
 532                 err = -EPERM;
 533                 if (!capable(CAP_NET_ADMIN))
 534                         break;
 535                 err = vlan_dev_set_vlan_flag(dev,
 536                                              args.u.flag,
 537                                              args.vlan_qos);
 538                 break;
 539
 540         case SET_VLAN_NAME_TYPE_CMD:
 541                 err = -EPERM;
 542                 if (!capable(CAP_NET_ADMIN))
 543                         break;
 544                 if ((args.u.name_type >= 0) &&
 545                     (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
 546                         vlan_name_type = args.u.name_type;
 547                         err = 0;
 548                 } else {
 549                         err = -EINVAL;
 550                 }
 551                 break;
 552
 553         case ADD_VLAN_CMD:
 554                 err = -EPERM;
 555                 if (!capable(CAP_NET_ADMIN))
 556                         break;
 557                 err = register_vlan_device(dev, args.u.VID);
 558                 break;
 559
 560         case DEL_VLAN_CMD:
 561                 err = -EPERM;
 562                 if (!capable(CAP_NET_ADMIN))
 563                         break;
 564                 unregister_vlan_dev(dev);
 565                 err = 0;
 566                 break;
 567
 568         case GET_VLAN_REALDEV_NAME_CMD:
 569                 err = 0;
 570                 vlan_dev_get_realdev_name(dev, args.u.device2);
 571                 if (copy_to_user(arg, &args,
 572                                  sizeof(struct vlan_ioctl_args))) {
 573                         err = -EFAULT;
 574                 }
 575                 break;
 576
 577         case GET_VLAN_VID_CMD:
 578                 err = 0;
 579                 vlan_dev_get_vid(dev, &vid);
 580                 args.u.VID = vid;
 581                 if (copy_to_user(arg, &args,
 582                                  sizeof(struct vlan_ioctl_args))) {
 583                       err = -EFAULT;
 584                 }
 585                 break;
 586
 587         default:
 588                 err = -EOPNOTSUPP;
 589                 break;
 590         }
 591 out:
 592         rtnl_unlock();
 593         return err;
 594 }
 595
 596 static int __init vlan_proto_init(void)
 597 {
 598         int err;
 599
 600         pr_info("%s v%s %s\n", vlan_fullname, vlan_version, vlan_copyright);
 601         pr_info("All bugs added by %s\n", vlan_buggyright);
 602
 603         err = vlan_proc_init();
 604         if (err < 0)
 605                 goto err1;
 606
 607         err = register_netdevice_notifier(&vlan_notifier_block);
 608         if (err < 0)
 609                 goto err2;
 610
 611         err = vlan_netlink_init();
 612         if (err < 0)
 613                 goto err3;
 614
 615         dev_add_pack(&vlan_packet_type);
 616         vlan_ioctl_set(vlan_ioctl_handler);
 617         return 0;
 618
 619 err3:
 620         unregister_netdevice_notifier(&vlan_notifier_block);
 621 err2:
 622         vlan_proc_cleanup();
 623 err1:
 624         return err;
 625 }
 626
 627 static void __exit vlan_cleanup_module(void)
 628 {
 629         unsigned int i;
 630
 631         vlan_ioctl_set(NULL);
 632         vlan_netlink_fini();
 633
 634         unregister_netdevice_notifier(&vlan_notifier_block);
 635
 636         dev_remove_pack(&vlan_packet_type);
 637
 638         /* This table must be empty if there are no module references left. */
 639         for (i = 0; i < VLAN_GRP_HASH_SIZE; i++)
 640                 BUG_ON(!hlist_empty(&vlan_group_hash[i]));
 641
 642         vlan_proc_cleanup();
 643
 644         synchronize_net();
 645 }
 646
 647 module_init(vlan_proto_init);
 648 module_exit(vlan_cleanup_module);
 649
 650 MODULE_LICENSE("GPL");
 651 MODULE_VERSION(DRV_VERSION);