kernel/net/bridge/br_vlan.c

   1 #include <linux/kernel.h>
   2 #include <linux/netdevice.h>
   3 #include <linux/rtnetlink.h>
   4 #include <linux/slab.h>
   5
   6 #include "br_private.h"
   7
   8 static void __vlan_add_pvid(struct net_port_vlans *v, u16 vid)
   9 {
  10         if (v->pvid == vid)
  11                 return;
  12
  13         smp_wmb();
  14         v->pvid = vid;
  15 }
  16
  17 static void __vlan_delete_pvid(struct net_port_vlans *v, u16 vid)
  18 {
  19         if (v->pvid != vid)
  20                 return;
  21
  22         smp_wmb();
  23         v->pvid = 0;
  24 }
  25
  26 static void __vlan_add_flags(struct net_port_vlans *v, u16 vid, u16 flags)
  27 {
  28         if (flags & BRIDGE_VLAN_INFO_PVID)
  29                 __vlan_add_pvid(v, vid);
  30         else
  31                 __vlan_delete_pvid(v, vid);
  32
  33         if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
  34                 set_bit(vid, v->untagged_bitmap);
  35         else
  36                 clear_bit(vid, v->untagged_bitmap);
  37 }
  38
  39 static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
  40 {
  41         struct net_bridge_port *p = NULL;
  42         struct net_bridge *br;
  43         struct net_device *dev;
  44         int err;
  45
  46         if (test_bit(vid, v->vlan_bitmap)) {
  47                 __vlan_add_flags(v, vid, flags);
  48                 return 0;
  49         }
  50
  51         if (v->port_idx) {
  52                 p = v->parent.port;
  53                 br = p->br;
  54                 dev = p->dev;
  55         } else {
  56                 br = v->parent.br;
  57                 dev = br->dev;
  58         }
  59
  60         if (p) {
  61                 /* Add VLAN to the device filter if it is supported.
  62                  * This ensures tagged traffic enters the bridge when
  63                  * promiscuous mode is disabled by br_manage_promisc().
  64                  */
  65                 err = vlan_vid_add(dev, br->vlan_proto, vid);
  66                 if (err)
  67                         return err;
  68         }
  69
  70         err = br_fdb_insert(br, p, dev->dev_addr, vid);
  71         if (err) {
  72                 br_err(br, "failed insert local address into bridge "
  73                        "forwarding table\n");
  74                 goto out_filt;
  75         }
  76
  77         set_bit(vid, v->vlan_bitmap);
  78         v->num_vlans++;
  79         __vlan_add_flags(v, vid, flags);
  80
  81         return 0;
  82
  83 out_filt:
  84         if (p)
  85                 vlan_vid_del(dev, br->vlan_proto, vid);
  86         return err;
  87 }
  88
  89 static int __vlan_del(struct net_port_vlans *v, u16 vid)
  90 {
  91         if (!test_bit(vid, v->vlan_bitmap))
  92                 return -EINVAL;
  93
  94         __vlan_delete_pvid(v, vid);
  95         clear_bit(vid, v->untagged_bitmap);
  96
  97         if (v->port_idx) {
  98                 struct net_bridge_port *p = v->parent.port;
  99                 vlan_vid_del(p->dev, p->br->vlan_proto, vid);
 100         }
 101
 102         clear_bit(vid, v->vlan_bitmap);
 103         v->num_vlans--;
 104         if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
 105                 if (v->port_idx)
 106                         RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 107                 else
 108                         RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 109                 kfree_rcu(v, rcu);
 110         }
 111         return 0;
 112 }
 113
 114 static void __vlan_flush(struct net_port_vlans *v)
 115 {
 116         smp_wmb();
 117         v->pvid = 0;
 118         bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
 119         if (v->port_idx)
 120                 RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 121         else
 122                 RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 123         kfree_rcu(v, rcu);
 124 }
 125
 126 struct sk_buff *br_handle_vlan(struct net_bridge *br,
 127                                const struct net_port_vlans *pv,
 128                                struct sk_buff *skb)
 129 {
 130         u16 vid;
 131
 132         /* If this packet was not filtered at input, let it pass */
 133         if (!BR_INPUT_SKB_CB(skb)->vlan_filtered)
 134                 goto out;
 135
 136         /* Vlan filter table must be configured at this point.  The
 137          * only exception is the bridge is set in promisc mode and the
 138          * packet is destined for the bridge device.  In this case
 139          * pass the packet as is.
 140          */
 141         if (!pv) {
 142                 if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
 143                         goto out;
 144                 } else {
 145                         kfree_skb(skb);
 146                         return NULL;
 147                 }
 148         }
 149
 150         /* At this point, we know that the frame was filtered and contains
 151          * a valid vlan id.  If the vlan id is set in the untagged bitmap,
 152          * send untagged; otherwise, send tagged.
 153          */
 154         br_vlan_get_tag(skb, &vid);
 155         if (test_bit(vid, pv->untagged_bitmap))
 156                 skb->vlan_tci = 0;
 157
 158 out:
 159         return skb;
 160 }
 161
 162 /* Called under RCU */
 163 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
 164                         struct sk_buff *skb, u16 *vid)
 165 {
 166         bool tagged;
 167         __be16 proto;
 168
 169         /* If VLAN filtering is disabled on the bridge, all packets are
 170          * permitted.
 171          */
 172         if (!br->vlan_enabled) {
 173                 BR_INPUT_SKB_CB(skb)->vlan_filtered = false;
 174                 return true;
 175         }
 176
 177         /* If there are no vlan in the permitted list, all packets are
 178          * rejected.
 179          */
 180         if (!v)
 181                 goto drop;
 182
 183         BR_INPUT_SKB_CB(skb)->vlan_filtered = true;
 184         proto = br->vlan_proto;
 185
 186         /* If vlan tx offload is disabled on bridge device and frame was
 187          * sent from vlan device on the bridge device, it does not have
 188          * HW accelerated vlan tag.
 189          */
 190         if (unlikely(!skb_vlan_tag_present(skb) &&
 191                      skb->protocol == proto)) {
 192                 skb = skb_vlan_untag(skb);
 193                 if (unlikely(!skb))
 194                         return false;
 195         }
 196
 197         if (!br_vlan_get_tag(skb, vid)) {
 198                 /* Tagged frame */
 199                 if (skb->vlan_proto != proto) {
 200                         /* Protocol-mismatch, empty out vlan_tci for new tag */
 201                         skb_push(skb, ETH_HLEN);
 202                         skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
 203                                                         skb_vlan_tag_get(skb));
 204                         if (unlikely(!skb))
 205                                 return false;
 206
 207                         skb_pull(skb, ETH_HLEN);
 208                         skb_reset_mac_len(skb);
 209                         *vid = 0;
 210                         tagged = false;
 211                 } else {
 212                         tagged = true;
 213                 }
 214         } else {
 215                 /* Untagged frame */
 216                 tagged = false;
 217         }
 218
 219         if (!*vid) {
 220                 u16 pvid = br_get_pvid(v);
 221
 222                 /* Frame had a tag with VID 0 or did not have a tag.
 223                  * See if pvid is set on this port.  That tells us which
 224                  * vlan untagged or priority-tagged traffic belongs to.
 225                  */
 226                 if (!pvid)
 227                         goto drop;
 228
 229                 /* PVID is set on this port.  Any untagged or priority-tagged
 230                  * ingress frame is considered to belong to this vlan.
 231                  */
 232                 *vid = pvid;
 233                 if (likely(!tagged))
 234                         /* Untagged Frame. */
 235                         __vlan_hwaccel_put_tag(skb, proto, pvid);
 236                 else
 237                         /* Priority-tagged Frame.
 238                          * At this point, We know that skb->vlan_tci had
 239                          * VLAN_TAG_PRESENT bit and its VID field was 0x000.
 240                          * We update only VID field and preserve PCP field.
 241                          */
 242                         skb->vlan_tci |= pvid;
 243
 244                 return true;
 245         }
 246
 247         /* Frame had a valid vlan tag.  See if vlan is allowed */
 248         if (test_bit(*vid, v->vlan_bitmap))
 249                 return true;
 250 drop:
 251         kfree_skb(skb);
 252         return false;
 253 }
 254
 255 /* Called under RCU. */
 256 bool br_allowed_egress(struct net_bridge *br,
 257                        const struct net_port_vlans *v,
 258                        const struct sk_buff *skb)
 259 {
 260         u16 vid;
 261
 262         /* If this packet was not filtered at input, let it pass */
 263         if (!BR_INPUT_SKB_CB(skb)->vlan_filtered)
 264                 return true;
 265
 266         if (!v)
 267                 return false;
 268
 269         br_vlan_get_tag(skb, &vid);
 270         if (test_bit(vid, v->vlan_bitmap))
 271                 return true;
 272
 273         return false;
 274 }
 275
 276 /* Called under RCU */
 277 bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
 278 {
 279         struct net_bridge *br = p->br;
 280         struct net_port_vlans *v;
 281
 282         /* If filtering was disabled at input, let it pass. */
 283         if (!br->vlan_enabled)
 284                 return true;
 285
 286         v = rcu_dereference(p->vlan_info);
 287         if (!v)
 288                 return false;
 289
 290         if (!br_vlan_get_tag(skb, vid) && skb->vlan_proto != br->vlan_proto)
 291                 *vid = 0;
 292
 293         if (!*vid) {
 294                 *vid = br_get_pvid(v);
 295                 if (!*vid)
 296                         return false;
 297
 298                 return true;
 299         }
 300
 301         if (test_bit(*vid, v->vlan_bitmap))
 302                 return true;
 303
 304         return false;
 305 }
 306
 307 /* Must be protected by RTNL.
 308  * Must be called with vid in range from 1 to 4094 inclusive.
 309  */
 310 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 311 {
 312         struct net_port_vlans *pv = NULL;
 313         int err;
 314
 315         ASSERT_RTNL();
 316
 317         pv = rtnl_dereference(br->vlan_info);
 318         if (pv)
 319                 return __vlan_add(pv, vid, flags);
 320
 321         /* Create port vlan infomration
 322          */
 323         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 324         if (!pv)
 325                 return -ENOMEM;
 326
 327         pv->parent.br = br;
 328         err = __vlan_add(pv, vid, flags);
 329         if (err)
 330                 goto out;
 331
 332         rcu_assign_pointer(br->vlan_info, pv);
 333         return 0;
 334 out:
 335         kfree(pv);
 336         return err;
 337 }
 338
 339 /* Must be protected by RTNL.
 340  * Must be called with vid in range from 1 to 4094 inclusive.
 341  */
 342 int br_vlan_delete(struct net_bridge *br, u16 vid)
 343 {
 344         struct net_port_vlans *pv;
 345
 346         ASSERT_RTNL();
 347
 348         pv = rtnl_dereference(br->vlan_info);
 349         if (!pv)
 350                 return -EINVAL;
 351
 352         br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
 353
 354         __vlan_del(pv, vid);
 355         return 0;
 356 }
 357
 358 void br_vlan_flush(struct net_bridge *br)
 359 {
 360         struct net_port_vlans *pv;
 361
 362         ASSERT_RTNL();
 363         pv = rtnl_dereference(br->vlan_info);
 364         if (!pv)
 365                 return;
 366
 367         __vlan_flush(pv);
 368 }
 369
 370 bool br_vlan_find(struct net_bridge *br, u16 vid)
 371 {
 372         struct net_port_vlans *pv;
 373         bool found = false;
 374
 375         rcu_read_lock();
 376         pv = rcu_dereference(br->vlan_info);
 377
 378         if (!pv)
 379                 goto out;
 380
 381         if (test_bit(vid, pv->vlan_bitmap))
 382                 found = true;
 383
 384 out:
 385         rcu_read_unlock();
 386         return found;
 387 }
 388
 389 /* Must be protected by RTNL. */
 390 static void recalculate_group_addr(struct net_bridge *br)
 391 {
 392         if (br->group_addr_set)
 393                 return;
 394
 395         spin_lock_bh(&br->lock);
 396         if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q)) {
 397                 /* Bridge Group Address */
 398                 br->group_addr[5] = 0x00;
 399         } else { /* vlan_enabled && ETH_P_8021AD */
 400                 /* Provider Bridge Group Address */
 401                 br->group_addr[5] = 0x08;
 402         }
 403         spin_unlock_bh(&br->lock);
 404 }
 405
 406 /* Must be protected by RTNL. */
 407 void br_recalculate_fwd_mask(struct net_bridge *br)
 408 {
 409         if (!br->vlan_enabled || br->vlan_proto == htons(ETH_P_8021Q))
 410                 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 411         else /* vlan_enabled && ETH_P_8021AD */
 412                 br->group_fwd_mask_required = BR_GROUPFWD_8021AD &
 413                                               ~(1u << br->group_addr[5]);
 414 }
 415
 416 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 417 {
 418         if (!rtnl_trylock())
 419                 return restart_syscall();
 420
 421         if (br->vlan_enabled == val)
 422                 goto unlock;
 423
 424         br->vlan_enabled = val;
 425         br_manage_promisc(br);
 426         recalculate_group_addr(br);
 427         br_recalculate_fwd_mask(br);
 428
 429 unlock:
 430         rtnl_unlock();
 431         return 0;
 432 }
 433
 434 int br_vlan_set_proto(struct net_bridge *br, unsigned long val)
 435 {
 436         int err = 0;
 437         struct net_bridge_port *p;
 438         struct net_port_vlans *pv;
 439         __be16 proto, oldproto;
 440         u16 vid, errvid;
 441
 442         if (val != ETH_P_8021Q && val != ETH_P_8021AD)
 443                 return -EPROTONOSUPPORT;
 444
 445         if (!rtnl_trylock())
 446                 return restart_syscall();
 447
 448         proto = htons(val);
 449         if (br->vlan_proto == proto)
 450                 goto unlock;
 451
 452         /* Add VLANs for the new proto to the device filter. */
 453         list_for_each_entry(p, &br->port_list, list) {
 454                 pv = rtnl_dereference(p->vlan_info);
 455                 if (!pv)
 456                         continue;
 457
 458                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID) {
 459                         err = vlan_vid_add(p->dev, proto, vid);
 460                         if (err)
 461                                 goto err_filt;
 462                 }
 463         }
 464
 465         oldproto = br->vlan_proto;
 466         br->vlan_proto = proto;
 467
 468         recalculate_group_addr(br);
 469         br_recalculate_fwd_mask(br);
 470
 471         /* Delete VLANs for the old proto from the device filter. */
 472         list_for_each_entry(p, &br->port_list, list) {
 473                 pv = rtnl_dereference(p->vlan_info);
 474                 if (!pv)
 475                         continue;
 476
 477                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 478                         vlan_vid_del(p->dev, oldproto, vid);
 479         }
 480
 481 unlock:
 482         rtnl_unlock();
 483         return err;
 484
 485 err_filt:
 486         errvid = vid;
 487         for_each_set_bit(vid, pv->vlan_bitmap, errvid)
 488                 vlan_vid_del(p->dev, proto, vid);
 489
 490         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 491                 pv = rtnl_dereference(p->vlan_info);
 492                 if (!pv)
 493                         continue;
 494
 495                 for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 496                         vlan_vid_del(p->dev, proto, vid);
 497         }
 498
 499         goto unlock;
 500 }
 501
 502 static bool vlan_default_pvid(struct net_port_vlans *pv, u16 vid)
 503 {
 504         return pv && vid == pv->pvid && test_bit(vid, pv->untagged_bitmap);
 505 }
 506
 507 static void br_vlan_disable_default_pvid(struct net_bridge *br)
 508 {
 509         struct net_bridge_port *p;
 510         u16 pvid = br->default_pvid;
 511
 512         /* Disable default_pvid on all ports where it is still
 513          * configured.
 514          */
 515         if (vlan_default_pvid(br_get_vlan_info(br), pvid))
 516                 br_vlan_delete(br, pvid);
 517
 518         list_for_each_entry(p, &br->port_list, list) {
 519                 if (vlan_default_pvid(nbp_get_vlan_info(p), pvid))
 520                         nbp_vlan_delete(p, pvid);
 521         }
 522
 523         br->default_pvid = 0;
 524 }
 525
 526 static int __br_vlan_set_default_pvid(struct net_bridge *br, u16 pvid)
 527 {
 528         struct net_bridge_port *p;
 529         u16 old_pvid;
 530         int err = 0;
 531         unsigned long *changed;
 532
 533         changed = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
 534                           GFP_KERNEL);
 535         if (!changed)
 536                 return -ENOMEM;
 537
 538         old_pvid = br->default_pvid;
 539
 540         /* Update default_pvid config only if we do not conflict with
 541          * user configuration.
 542          */
 543         if ((!old_pvid || vlan_default_pvid(br_get_vlan_info(br), old_pvid)) &&
 544             !br_vlan_find(br, pvid)) {
 545                 err = br_vlan_add(br, pvid,
 546                                   BRIDGE_VLAN_INFO_PVID |
 547                                   BRIDGE_VLAN_INFO_UNTAGGED);
 548                 if (err)
 549                         goto out;
 550                 br_vlan_delete(br, old_pvid);
 551                 set_bit(0, changed);
 552         }
 553
 554         list_for_each_entry(p, &br->port_list, list) {
 555                 /* Update default_pvid config only if we do not conflict with
 556                  * user configuration.
 557                  */
 558                 if ((old_pvid &&
 559                      !vlan_default_pvid(nbp_get_vlan_info(p), old_pvid)) ||
 560                     nbp_vlan_find(p, pvid))
 561                         continue;
 562
 563                 err = nbp_vlan_add(p, pvid,
 564                                    BRIDGE_VLAN_INFO_PVID |
 565                                    BRIDGE_VLAN_INFO_UNTAGGED);
 566                 if (err)
 567                         goto err_port;
 568                 nbp_vlan_delete(p, old_pvid);
 569                 set_bit(p->port_no, changed);
 570         }
 571
 572         br->default_pvid = pvid;
 573
 574 out:
 575         kfree(changed);
 576         return err;
 577
 578 err_port:
 579         list_for_each_entry_continue_reverse(p, &br->port_list, list) {
 580                 if (!test_bit(p->port_no, changed))
 581                         continue;
 582
 583                 if (old_pvid)
 584                         nbp_vlan_add(p, old_pvid,
 585                                      BRIDGE_VLAN_INFO_PVID |
 586                                      BRIDGE_VLAN_INFO_UNTAGGED);
 587                 nbp_vlan_delete(p, pvid);
 588         }
 589
 590         if (test_bit(0, changed)) {
 591                 if (old_pvid)
 592                         br_vlan_add(br, old_pvid,
 593                                     BRIDGE_VLAN_INFO_PVID |
 594                                     BRIDGE_VLAN_INFO_UNTAGGED);
 595                 br_vlan_delete(br, pvid);
 596         }
 597         goto out;
 598 }
 599
 600 int br_vlan_set_default_pvid(struct net_bridge *br, unsigned long val)
 601 {
 602         u16 pvid = val;
 603         int err = 0;
 604
 605         if (val >= VLAN_VID_MASK)
 606                 return -EINVAL;
 607
 608         if (!rtnl_trylock())
 609                 return restart_syscall();
 610
 611         if (pvid == br->default_pvid)
 612                 goto unlock;
 613
 614         /* Only allow default pvid change when filtering is disabled */
 615         if (br->vlan_enabled) {
 616                 pr_info_once("Please disable vlan filtering to change default_pvid\n");
 617                 err = -EPERM;
 618                 goto unlock;
 619         }
 620
 621         if (!pvid)
 622                 br_vlan_disable_default_pvid(br);
 623         else
 624                 err = __br_vlan_set_default_pvid(br, pvid);
 625
 626 unlock:
 627         rtnl_unlock();
 628         return err;
 629 }
 630
 631 int br_vlan_init(struct net_bridge *br)
 632 {
 633         br->vlan_proto = htons(ETH_P_8021Q);
 634         br->default_pvid = 1;
 635         return br_vlan_add(br, 1,
 636                            BRIDGE_VLAN_INFO_PVID | BRIDGE_VLAN_INFO_UNTAGGED);
 637 }
 638
 639 /* Must be protected by RTNL.
 640  * Must be called with vid in range from 1 to 4094 inclusive.
 641  */
 642 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 643 {
 644         struct net_port_vlans *pv = NULL;
 645         int err;
 646
 647         ASSERT_RTNL();
 648
 649         pv = rtnl_dereference(port->vlan_info);
 650         if (pv)
 651                 return __vlan_add(pv, vid, flags);
 652
 653         /* Create port vlan infomration
 654          */
 655         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 656         if (!pv) {
 657                 err = -ENOMEM;
 658                 goto clean_up;
 659         }
 660
 661         pv->port_idx = port->port_no;
 662         pv->parent.port = port;
 663         err = __vlan_add(pv, vid, flags);
 664         if (err)
 665                 goto clean_up;
 666
 667         rcu_assign_pointer(port->vlan_info, pv);
 668         return 0;
 669
 670 clean_up:
 671         kfree(pv);
 672         return err;
 673 }
 674
 675 /* Must be protected by RTNL.
 676  * Must be called with vid in range from 1 to 4094 inclusive.
 677  */
 678 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 679 {
 680         struct net_port_vlans *pv;
 681
 682         ASSERT_RTNL();
 683
 684         pv = rtnl_dereference(port->vlan_info);
 685         if (!pv)
 686                 return -EINVAL;
 687
 688         br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
 689
 690         return __vlan_del(pv, vid);
 691 }
 692
 693 void nbp_vlan_flush(struct net_bridge_port *port)
 694 {
 695         struct net_port_vlans *pv;
 696         u16 vid;
 697
 698         ASSERT_RTNL();
 699
 700         pv = rtnl_dereference(port->vlan_info);
 701         if (!pv)
 702                 return;
 703
 704         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 705                 vlan_vid_del(port->dev, port->br->vlan_proto, vid);
 706
 707         __vlan_flush(pv);
 708 }
 709
 710 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
 711 {
 712         struct net_port_vlans *pv;
 713         bool found = false;
 714
 715         rcu_read_lock();
 716         pv = rcu_dereference(port->vlan_info);
 717
 718         if (!pv)
 719                 goto out;
 720
 721         if (test_bit(vid, pv->vlan_bitmap))
 722                 found = true;
 723
 724 out:
 725         rcu_read_unlock();
 726         return found;
 727 }
 728
 729 int nbp_vlan_init(struct net_bridge_port *p)
 730 {
 731         return p->br->default_pvid ?
 732                         nbp_vlan_add(p, p->br->default_pvid,
 733                                      BRIDGE_VLAN_INFO_PVID |
 734                                      BRIDGE_VLAN_INFO_UNTAGGED) :
 735                         0;
 736 }