net/8021q/vlan.c

   1 /*
   2  * INET         802.1Q VLAN
   3  *              Ethernet-type device handling.
   4  *
   5  * Authors:     Ben Greear <greearb@candelatech.com>
   6  *              Please send support related email to: netdev@vger.kernel.org
   7  *              VLAN Home Page: http://www.candelatech.com/~greear/vlan.html
   8  *
   9  * Fixes:
  10  *              Fix for packet capture - Nick Eggleston <nick@dccinc.com>;
  11  *              Add HW acceleration hooks - David S. Miller <davem@redhat.com>;
  12  *              Correct all the locking - David S. Miller <davem@redhat.com>;
  13  *              Use hash table for VLAN groups - David S. Miller <davem@redhat.com>
  14  *
  15  *              This program is free software; you can redistribute it and/or
  16  *              modify it under the terms of the GNU General Public License
  17  *              as published by the Free Software Foundation; either version
  18  *              2 of the License, or (at your option) any later version.
  19  */
  20
  21 #include <asm/uaccess.h> /* for copy_from_user */
  22 #include <linux/capability.h>
  23 #include <linux/module.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/skbuff.h>
  26 #include <net/datalink.h>
  27 #include <linux/mm.h>
  28 #include <linux/in.h>
  29 #include <linux/init.h>
  30 #include <net/p8022.h>
  31 #include <net/arp.h>
  32 #include <linux/rtnetlink.h>
  33 #include <linux/notifier.h>
  34 #include <net/net_namespace.h>
  35
  36 #include <linux/if_vlan.h>
  37 #include "vlan.h"
  38 #include "vlanproc.h"
  39
  40 #define DRV_VERSION "1.8"
  41
  42 /* Global VLAN variables */
  43
  44 /* Our listing of VLAN group(s) */
  45 static struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
  46
  47 static char vlan_fullname[] = "802.1Q VLAN Support";
  48 static char vlan_version[] = DRV_VERSION;
  49 static char vlan_copyright[] = "Ben Greear <greearb@candelatech.com>";
  50 static char vlan_buggyright[] = "David S. Miller <davem@redhat.com>";
  51
  52 /* Determines interface naming scheme. */
  53 unsigned short vlan_name_type = VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD;
  54
  55 static struct packet_type vlan_packet_type = {
  56         .type = __constant_htons(ETH_P_8021Q),
  57         .func = vlan_skb_recv, /* VLAN receive method */
  58 };
  59
  60 /* End of global variables definitions. */
  61
  62 static inline unsigned int vlan_grp_hashfn(unsigned int idx)
  63 {
  64         return ((idx >> VLAN_GRP_HASH_SHIFT) ^ idx) & VLAN_GRP_HASH_MASK;
  65 }
  66
  67 /* Must be invoked with RCU read lock (no preempt) */
  68 static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
  69 {
  70         struct vlan_group *grp;
  71         struct hlist_node *n;
  72         int hash = vlan_grp_hashfn(real_dev_ifindex);
  73
  74         hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
  75                 if (grp->real_dev_ifindex == real_dev_ifindex)
  76                         return grp;
  77         }
  78
  79         return NULL;
  80 }
  81
  82 /*  Find the protocol handler.  Assumes VID < VLAN_VID_MASK.
  83  *
  84  * Must be invoked with RCU read lock (no preempt)
  85  */
  86 struct net_device *__find_vlan_dev(struct net_device *real_dev,
  87                                    unsigned short VID)
  88 {
  89         struct vlan_group *grp = __vlan_find_group(real_dev->ifindex);
  90
  91         if (grp)
  92                 return vlan_group_get_device(grp, VID);
  93
  94         return NULL;
  95 }
  96
  97 static void vlan_group_free(struct vlan_group *grp)
  98 {
  99         int i;
 100
 101         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
 102                 kfree(grp->vlan_devices_arrays[i]);
 103         kfree(grp);
 104 }
 105
 106 static struct vlan_group *vlan_group_alloc(int ifindex)
 107 {
 108         struct vlan_group *grp;
 109         unsigned int size;
 110         unsigned int i;
 111
 112         grp = kzalloc(sizeof(struct vlan_group), GFP_KERNEL);
 113         if (!grp)
 114                 return NULL;
 115
 116         size = sizeof(struct net_device *) * VLAN_GROUP_ARRAY_PART_LEN;
 117
 118         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++) {
 119                 grp->vlan_devices_arrays[i] = kzalloc(size, GFP_KERNEL);
 120                 if (!grp->vlan_devices_arrays[i])
 121                         goto err;
 122         }
 123
 124         grp->real_dev_ifindex = ifindex;
 125         hlist_add_head_rcu(&grp->hlist,
 126                            &vlan_group_hash[vlan_grp_hashfn(ifindex)]);
 127         return grp;
 128
 129 err:
 130         vlan_group_free(grp);
 131         return NULL;
 132 }
 133
 134 static void vlan_rcu_free(struct rcu_head *rcu)
 135 {
 136         vlan_group_free(container_of(rcu, struct vlan_group, rcu));
 137 }
 138
 139 void unregister_vlan_dev(struct net_device *dev)
 140 {
 141         struct vlan_dev_info *vlan = vlan_dev_info(dev);
 142         struct net_device *real_dev = vlan->real_dev;
 143         struct vlan_group *grp;
 144         unsigned short vlan_id = vlan->vlan_id;
 145
 146         ASSERT_RTNL();
 147
 148         grp = __vlan_find_group(real_dev->ifindex);
 149         BUG_ON(!grp);
 150
 151         vlan_proc_rem_dev(dev);
 152
 153         /* Take it out of our own structures, but be sure to interlock with
 154          * HW accelerating devices or SW vlan input packet processing.
 155          */
 156         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
 157                 real_dev->vlan_rx_kill_vid(real_dev, vlan_id);
 158
 159         vlan_group_set_device(grp, vlan_id, NULL);
 160         grp->nr_vlans--;
 161
 162         synchronize_net();
 163
 164         /* If the group is now empty, kill off the group. */
 165         if (grp->nr_vlans == 0) {
 166                 if (real_dev->features & NETIF_F_HW_VLAN_RX)
 167                         real_dev->vlan_rx_register(real_dev, NULL);
 168
 169                 hlist_del_rcu(&grp->hlist);
 170
 171                 /* Free the group, after all cpu's are done. */
 172                 call_rcu(&grp->rcu, vlan_rcu_free);
 173         }
 174
 175         /* Get rid of the vlan's reference to real_dev */
 176         dev_put(real_dev);
 177
 178         unregister_netdevice(dev);
 179 }
 180
 181 static void vlan_transfer_operstate(const struct net_device *dev,
 182                                     struct net_device *vlandev)
 183 {
 184         /* Have to respect userspace enforced dormant state
 185          * of real device, also must allow supplicant running
 186          * on VLAN device
 187          */
 188         if (dev->operstate == IF_OPER_DORMANT)
 189                 netif_dormant_on(vlandev);
 190         else
 191                 netif_dormant_off(vlandev);
 192
 193         if (netif_carrier_ok(dev)) {
 194                 if (!netif_carrier_ok(vlandev))
 195                         netif_carrier_on(vlandev);
 196         } else {
 197                 if (netif_carrier_ok(vlandev))
 198                         netif_carrier_off(vlandev);
 199         }
 200 }
 201
 202 int vlan_check_real_dev(struct net_device *real_dev, unsigned short vlan_id)
 203 {
 204         char *name = real_dev->name;
 205
 206         if (real_dev->features & NETIF_F_VLAN_CHALLENGED) {
 207                 pr_info("8021q: VLANs not supported on %s\n", name);
 208                 return -EOPNOTSUPP;
 209         }
 210
 211         if ((real_dev->features & NETIF_F_HW_VLAN_RX) &&
 212             !real_dev->vlan_rx_register) {
 213                 pr_info("8021q: device %s has buggy VLAN hw accel\n", name);
 214                 return -EOPNOTSUPP;
 215         }
 216
 217         if ((real_dev->features & NETIF_F_HW_VLAN_FILTER) &&
 218             (!real_dev->vlan_rx_add_vid || !real_dev->vlan_rx_kill_vid)) {
 219                 pr_info("8021q: Device %s has buggy VLAN hw accel\n", name);
 220                 return -EOPNOTSUPP;
 221         }
 222
 223         /* The real device must be up and operating in order to
 224          * assosciate a VLAN device with it.
 225          */
 226         if (!(real_dev->flags & IFF_UP))
 227                 return -ENETDOWN;
 228
 229         if (__find_vlan_dev(real_dev, vlan_id) != NULL)
 230                 return -EEXIST;
 231
 232         return 0;
 233 }
 234
 235 int register_vlan_dev(struct net_device *dev)
 236 {
 237         struct vlan_dev_info *vlan = vlan_dev_info(dev);
 238         struct net_device *real_dev = vlan->real_dev;
 239         unsigned short vlan_id = vlan->vlan_id;
 240         struct vlan_group *grp, *ngrp = NULL;
 241         int err;
 242
 243         grp = __vlan_find_group(real_dev->ifindex);
 244         if (!grp) {
 245                 ngrp = grp = vlan_group_alloc(real_dev->ifindex);
 246                 if (!grp)
 247                         return -ENOBUFS;
 248         }
 249
 250         err = register_netdevice(dev);
 251         if (err < 0)
 252                 goto out_free_group;
 253
 254         /* Account for reference in struct vlan_dev_info */
 255         dev_hold(real_dev);
 256
 257         vlan_transfer_operstate(real_dev, dev);
 258         linkwatch_fire_event(dev); /* _MUST_ call rfc2863_policy() */
 259
 260         /* So, got the sucker initialized, now lets place
 261          * it into our local structure.
 262          */
 263         vlan_group_set_device(grp, vlan_id, dev);
 264         grp->nr_vlans++;
 265
 266         if (ngrp && real_dev->features & NETIF_F_HW_VLAN_RX)
 267                 real_dev->vlan_rx_register(real_dev, ngrp);
 268         if (real_dev->features & NETIF_F_HW_VLAN_FILTER)
 269                 real_dev->vlan_rx_add_vid(real_dev, vlan_id);
 270
 271         if (vlan_proc_add_dev(dev) < 0)
 272                 pr_warning("8021q: failed to add proc entry for %s\n",
 273                            dev->name);
 274         return 0;
 275
 276 out_free_group:
 277         if (ngrp)
 278                 vlan_group_free(ngrp);
 279         return err;
 280 }
 281
 282 /*  Attach a VLAN device to a mac address (ie Ethernet Card).
 283  *  Returns 0 if the device was created or a negative error code otherwise.
 284  */
 285 static int register_vlan_device(struct net_device *real_dev,
 286                                 unsigned short VLAN_ID)
 287 {
 288         struct net_device *new_dev;
 289         char name[IFNAMSIZ];
 290         int err;
 291
 292         if (VLAN_ID >= VLAN_VID_MASK)
 293                 return -ERANGE;
 294
 295         err = vlan_check_real_dev(real_dev, VLAN_ID);
 296         if (err < 0)
 297                 return err;
 298
 299         /* Gotta set up the fields for the device. */
 300         switch (vlan_name_type) {
 301         case VLAN_NAME_TYPE_RAW_PLUS_VID:
 302                 /* name will look like:  eth1.0005 */
 303                 snprintf(name, IFNAMSIZ, "%s.%.4i", real_dev->name, VLAN_ID);
 304                 break;
 305         case VLAN_NAME_TYPE_PLUS_VID_NO_PAD:
 306                 /* Put our vlan.VID in the name.
 307                  * Name will look like:  vlan5
 308                  */
 309                 snprintf(name, IFNAMSIZ, "vlan%i", VLAN_ID);
 310                 break;
 311         case VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD:
 312                 /* Put our vlan.VID in the name.
 313                  * Name will look like:  eth0.5
 314                  */
 315                 snprintf(name, IFNAMSIZ, "%s.%i", real_dev->name, VLAN_ID);
 316                 break;
 317         case VLAN_NAME_TYPE_PLUS_VID:
 318                 /* Put our vlan.VID in the name.
 319                  * Name will look like:  vlan0005
 320                  */
 321         default:
 322                 snprintf(name, IFNAMSIZ, "vlan%.4i", VLAN_ID);
 323         }
 324
 325         new_dev = alloc_netdev(sizeof(struct vlan_dev_info), name,
 326                                vlan_setup);
 327
 328         if (new_dev == NULL)
 329                 return -ENOBUFS;
 330
 331         /* need 4 bytes for extra VLAN header info,
 332          * hope the underlying device can handle it.
 333          */
 334         new_dev->mtu = real_dev->mtu;
 335
 336         vlan_dev_info(new_dev)->vlan_id = VLAN_ID; /* 1 through VLAN_VID_MASK */
 337         vlan_dev_info(new_dev)->real_dev = real_dev;
 338         vlan_dev_info(new_dev)->dent = NULL;
 339         vlan_dev_info(new_dev)->flags = VLAN_FLAG_REORDER_HDR;
 340
 341         new_dev->rtnl_link_ops = &vlan_link_ops;
 342         err = register_vlan_dev(new_dev);
 343         if (err < 0)
 344                 goto out_free_newdev;
 345
 346         return 0;
 347
 348 out_free_newdev:
 349         free_netdev(new_dev);
 350         return err;
 351 }
 352
 353 static void vlan_sync_address(struct net_device *dev,
 354                               struct net_device *vlandev)
 355 {
 356         struct vlan_dev_info *vlan = vlan_dev_info(vlandev);
 357
 358         /* May be called without an actual change */
 359         if (!compare_ether_addr(vlan->real_dev_addr, dev->dev_addr))
 360                 return;
 361
 362         /* vlan address was different from the old address and is equal to
 363          * the new address */
 364         if (compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
 365             !compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
 366                 dev_unicast_delete(dev, vlandev->dev_addr, ETH_ALEN);
 367
 368         /* vlan address was equal to the old address and is different from
 369          * the new address */
 370         if (!compare_ether_addr(vlandev->dev_addr, vlan->real_dev_addr) &&
 371             compare_ether_addr(vlandev->dev_addr, dev->dev_addr))
 372                 dev_unicast_add(dev, vlandev->dev_addr, ETH_ALEN);
 373
 374         memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
 375 }
 376
 377 static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 378                              void *ptr)
 379 {
 380         struct net_device *dev = ptr;
 381         struct vlan_group *grp = __vlan_find_group(dev->ifindex);
 382         int i, flgs;
 383         struct net_device *vlandev;
 384
 385         if (dev->nd_net != &init_net)
 386                 return NOTIFY_DONE;
 387
 388         if (!grp)
 389                 goto out;
 390
 391         /* It is OK that we do not hold the group lock right now,
 392          * as we run under the RTNL lock.
 393          */
 394
 395         switch (event) {
 396         case NETDEV_CHANGE:
 397                 /* Propagate real device state to vlan devices */
 398                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 399                         vlandev = vlan_group_get_device(grp, i);
 400                         if (!vlandev)
 401                                 continue;
 402
 403                         vlan_transfer_operstate(dev, vlandev);
 404                 }
 405                 break;
 406
 407         case NETDEV_CHANGEADDR:
 408                 /* Adjust unicast filters on underlying device */
 409                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 410                         vlandev = vlan_group_get_device(grp, i);
 411                         if (!vlandev)
 412                                 continue;
 413
 414                         flgs = vlandev->flags;
 415                         if (!(flgs & IFF_UP))
 416                                 continue;
 417
 418                         vlan_sync_address(dev, vlandev);
 419                 }
 420                 break;
 421
 422         case NETDEV_DOWN:
 423                 /* Put all VLANs for this dev in the down state too.  */
 424                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 425                         vlandev = vlan_group_get_device(grp, i);
 426                         if (!vlandev)
 427                                 continue;
 428
 429                         flgs = vlandev->flags;
 430                         if (!(flgs & IFF_UP))
 431                                 continue;
 432
 433                         dev_change_flags(vlandev, flgs & ~IFF_UP);
 434                 }
 435                 break;
 436
 437         case NETDEV_UP:
 438                 /* Put all VLANs for this dev in the up state too.  */
 439                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 440                         vlandev = vlan_group_get_device(grp, i);
 441                         if (!vlandev)
 442                                 continue;
 443
 444                         flgs = vlandev->flags;
 445                         if (flgs & IFF_UP)
 446                                 continue;
 447
 448                         dev_change_flags(vlandev, flgs | IFF_UP);
 449                 }
 450                 break;
 451
 452         case NETDEV_UNREGISTER:
 453                 /* Delete all VLANs for this dev. */
 454                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 455                         vlandev = vlan_group_get_device(grp, i);
 456                         if (!vlandev)
 457                                 continue;
 458
 459                         /* unregistration of last vlan destroys group, abort
 460                          * afterwards */
 461                         if (grp->nr_vlans == 1)
 462                                 i = VLAN_GROUP_ARRAY_LEN;
 463
 464                         unregister_vlan_dev(vlandev);
 465                 }
 466                 break;
 467         }
 468
 469 out:
 470         return NOTIFY_DONE;
 471 }
 472
 473 static struct notifier_block vlan_notifier_block __read_mostly = {
 474         .notifier_call = vlan_device_event,
 475 };
 476
 477 /*
 478  *      VLAN IOCTL handler.
 479  *      o execute requested action or pass command to the device driver
 480  *   arg is really a struct vlan_ioctl_args __user *.
 481  */
 482 static int vlan_ioctl_handler(struct net *net, void __user *arg)
 483 {
 484         int err;
 485         unsigned short vid = 0;
 486         struct vlan_ioctl_args args;
 487         struct net_device *dev = NULL;
 488
 489         if (copy_from_user(&args, arg, sizeof(struct vlan_ioctl_args)))
 490                 return -EFAULT;
 491
 492         /* Null terminate this sucker, just in case. */
 493         args.device1[23] = 0;
 494         args.u.device2[23] = 0;
 495
 496         rtnl_lock();
 497
 498         switch (args.cmd) {
 499         case SET_VLAN_INGRESS_PRIORITY_CMD:
 500         case SET_VLAN_EGRESS_PRIORITY_CMD:
 501         case SET_VLAN_FLAG_CMD:
 502         case ADD_VLAN_CMD:
 503         case DEL_VLAN_CMD:
 504         case GET_VLAN_REALDEV_NAME_CMD:
 505         case GET_VLAN_VID_CMD:
 506                 err = -ENODEV;
 507                 dev = __dev_get_by_name(&init_net, args.device1);
 508                 if (!dev)
 509                         goto out;
 510
 511                 err = -EINVAL;
 512                 if (args.cmd != ADD_VLAN_CMD &&
 513                     !(dev->priv_flags & IFF_802_1Q_VLAN))
 514                         goto out;
 515         }
 516
 517         switch (args.cmd) {
 518         case SET_VLAN_INGRESS_PRIORITY_CMD:
 519                 err = -EPERM;
 520                 if (!capable(CAP_NET_ADMIN))
 521                         break;
 522                 vlan_dev_set_ingress_priority(dev,
 523                                               args.u.skb_priority,
 524                                               args.vlan_qos);
 525                 err = 0;
 526                 break;
 527
 528         case SET_VLAN_EGRESS_PRIORITY_CMD:
 529                 err = -EPERM;
 530                 if (!capable(CAP_NET_ADMIN))
 531                         break;
 532                 err = vlan_dev_set_egress_priority(dev,
 533                                                    args.u.skb_priority,
 534                                                    args.vlan_qos);
 535                 break;
 536
 537         case SET_VLAN_FLAG_CMD:
 538                 err = -EPERM;
 539                 if (!capable(CAP_NET_ADMIN))
 540                         break;
 541                 err = vlan_dev_set_vlan_flag(dev,
 542                                              args.u.flag,
 543                                              args.vlan_qos);
 544                 break;
 545
 546         case SET_VLAN_NAME_TYPE_CMD:
 547                 err = -EPERM;
 548                 if (!capable(CAP_NET_ADMIN))
 549                         break;
 550                 if ((args.u.name_type >= 0) &&
 551                     (args.u.name_type < VLAN_NAME_TYPE_HIGHEST)) {
 552                         vlan_name_type = args.u.name_type;
 553                         err = 0;
 554                 } else {
 555                         err = -EINVAL;
 556                 }
 557                 break;
 558
 559         case ADD_VLAN_CMD:
 560                 err = -EPERM;
 561                 if (!capable(CAP_NET_ADMIN))
 562                         break;
 563                 err = register_vlan_device(dev, args.u.VID);
 564                 break;
 565
 566         case DEL_VLAN_CMD:
 567                 err = -EPERM;
 568                 if (!capable(CAP_NET_ADMIN))
 569                         break;
 570                 unregister_vlan_dev(dev);
 571                 err = 0;
 572                 break;
 573
 574         case GET_VLAN_REALDEV_NAME_CMD:
 575                 err = 0;
 576                 vlan_dev_get_realdev_name(dev, args.u.device2);
 577                 if (copy_to_user(arg, &args,
 578                                  sizeof(struct vlan_ioctl_args)))
 579                         err = -EFAULT;
 580                 break;
 581
 582         case GET_VLAN_VID_CMD:
 583                 err = 0;
 584                 vlan_dev_get_vid(dev, &vid);
 585                 args.u.VID = vid;
 586                 if (copy_to_user(arg, &args,
 587                                  sizeof(struct vlan_ioctl_args)))
 588                       err = -EFAULT;
 589                 break;
 590
 591         default:
 592                 err = -EOPNOTSUPP;
 593                 break;
 594         }
 595 out:
 596         rtnl_unlock();
 597         return err;
 598 }
 599
 600 static int __init vlan_proto_init(void)
 601 {
 602         int err;
 603
 604         pr_info("%s v%s %s\n", vlan_fullname, vlan_version, vlan_copyright);
 605         pr_info("All bugs added by %s\n", vlan_buggyright);
 606
 607         err = vlan_proc_init();
 608         if (err < 0)
 609                 goto err1;
 610
 611         err = register_netdevice_notifier(&vlan_notifier_block);
 612         if (err < 0)
 613                 goto err2;
 614
 615         err = vlan_netlink_init();
 616         if (err < 0)
 617                 goto err3;
 618
 619         dev_add_pack(&vlan_packet_type);
 620         vlan_ioctl_set(vlan_ioctl_handler);
 621         return 0;
 622
 623 err3:
 624         unregister_netdevice_notifier(&vlan_notifier_block);
 625 err2:
 626         vlan_proc_cleanup();
 627 err1:
 628         return err;
 629 }
 630
 631 static void __exit vlan_cleanup_module(void)
 632 {
 633         unsigned int i;
 634
 635         vlan_ioctl_set(NULL);
 636         vlan_netlink_fini();
 637
 638         unregister_netdevice_notifier(&vlan_notifier_block);
 639
 640         dev_remove_pack(&vlan_packet_type);
 641
 642         /* This table must be empty if there are no module references left. */
 643         for (i = 0; i < VLAN_GRP_HASH_SIZE; i++)
 644                 BUG_ON(!hlist_empty(&vlan_group_hash[i]));
 645
 646         vlan_proc_cleanup();
 647
 648         synchronize_net();
 649 }
 650
 651 module_init(vlan_proto_init);
 652 module_exit(vlan_cleanup_module);
 653
 654 MODULE_LICENSE("GPL");
 655 MODULE_VERSION(DRV_VERSION);