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
  31         if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
  32                 set_bit(vid, v->untagged_bitmap);
  33 }
  34
  35 static int __vlan_add(struct net_port_vlans *v, u16 vid, u16 flags)
  36 {
  37         struct net_bridge_port *p = NULL;
  38         struct net_bridge *br;
  39         struct net_device *dev;
  40         int err;
  41
  42         if (test_bit(vid, v->vlan_bitmap)) {
  43                 __vlan_add_flags(v, vid, flags);
  44                 return 0;
  45         }
  46
  47         if (v->port_idx) {
  48                 p = v->parent.port;
  49                 br = p->br;
  50                 dev = p->dev;
  51         } else {
  52                 br = v->parent.br;
  53                 dev = br->dev;
  54         }
  55
  56         if (p) {
  57                 /* Add VLAN to the device filter if it is supported.
  58                  * Stricly speaking, this is not necessary now, since
  59                  * devices are made promiscuous by the bridge, but if
  60                  * that ever changes this code will allow tagged
  61                  * traffic to enter the bridge.
  62                  */
  63                 err = vlan_vid_add(dev, htons(ETH_P_8021Q), vid);
  64                 if (err)
  65                         return err;
  66         }
  67
  68         err = br_fdb_insert(br, p, dev->dev_addr, vid);
  69         if (err) {
  70                 br_err(br, "failed insert local address into bridge "
  71                        "forwarding table\n");
  72                 goto out_filt;
  73         }
  74
  75         set_bit(vid, v->vlan_bitmap);
  76         v->num_vlans++;
  77         __vlan_add_flags(v, vid, flags);
  78
  79         return 0;
  80
  81 out_filt:
  82         if (p)
  83                 vlan_vid_del(dev, htons(ETH_P_8021Q), vid);
  84         return err;
  85 }
  86
  87 static int __vlan_del(struct net_port_vlans *v, u16 vid)
  88 {
  89         if (!test_bit(vid, v->vlan_bitmap))
  90                 return -EINVAL;
  91
  92         __vlan_delete_pvid(v, vid);
  93         clear_bit(vid, v->untagged_bitmap);
  94
  95         if (v->port_idx)
  96                 vlan_vid_del(v->parent.port->dev, htons(ETH_P_8021Q), vid);
  97
  98         clear_bit(vid, v->vlan_bitmap);
  99         v->num_vlans--;
 100         if (bitmap_empty(v->vlan_bitmap, VLAN_N_VID)) {
 101                 if (v->port_idx)
 102                         RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 103                 else
 104                         RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 105                 kfree_rcu(v, rcu);
 106         }
 107         return 0;
 108 }
 109
 110 static void __vlan_flush(struct net_port_vlans *v)
 111 {
 112         smp_wmb();
 113         v->pvid = 0;
 114         bitmap_zero(v->vlan_bitmap, VLAN_N_VID);
 115         if (v->port_idx)
 116                 RCU_INIT_POINTER(v->parent.port->vlan_info, NULL);
 117         else
 118                 RCU_INIT_POINTER(v->parent.br->vlan_info, NULL);
 119         kfree_rcu(v, rcu);
 120 }
 121
 122 struct sk_buff *br_handle_vlan(struct net_bridge *br,
 123                                const struct net_port_vlans *pv,
 124                                struct sk_buff *skb)
 125 {
 126         u16 vid;
 127
 128         if (!br->vlan_enabled)
 129                 goto out;
 130
 131         /* Vlan filter table must be configured at this point.  The
 132          * only exception is the bridge is set in promisc mode and the
 133          * packet is destined for the bridge device.  In this case
 134          * pass the packet as is.
 135          */
 136         if (!pv) {
 137                 if ((br->dev->flags & IFF_PROMISC) && skb->dev == br->dev) {
 138                         goto out;
 139                 } else {
 140                         kfree_skb(skb);
 141                         return NULL;
 142                 }
 143         }
 144
 145         /* At this point, we know that the frame was filtered and contains
 146          * a valid vlan id.  If the vlan id is set in the untagged bitmap,
 147          * send untagged; otherwise, send tagged.
 148          */
 149         br_vlan_get_tag(skb, &vid);
 150         if (test_bit(vid, pv->untagged_bitmap))
 151                 skb->vlan_tci = 0;
 152
 153 out:
 154         return skb;
 155 }
 156
 157 /* Called under RCU */
 158 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
 159                         struct sk_buff *skb, u16 *vid)
 160 {
 161         int err;
 162
 163         /* If VLAN filtering is disabled on the bridge, all packets are
 164          * permitted.
 165          */
 166         if (!br->vlan_enabled)
 167                 return true;
 168
 169         /* If there are no vlan in the permitted list, all packets are
 170          * rejected.
 171          */
 172         if (!v)
 173                 goto drop;
 174
 175         /* If vlan tx offload is disabled on bridge device and frame was
 176          * sent from vlan device on the bridge device, it does not have
 177          * HW accelerated vlan tag.
 178          */
 179         if (unlikely(!vlan_tx_tag_present(skb) &&
 180                      (skb->protocol == htons(ETH_P_8021Q) ||
 181                       skb->protocol == htons(ETH_P_8021AD)))) {
 182                 skb = vlan_untag(skb);
 183                 if (unlikely(!skb))
 184                         return false;
 185         }
 186
 187         err = br_vlan_get_tag(skb, vid);
 188         if (!*vid) {
 189                 u16 pvid = br_get_pvid(v);
 190
 191                 /* Frame had a tag with VID 0 or did not have a tag.
 192                  * See if pvid is set on this port.  That tells us which
 193                  * vlan untagged or priority-tagged traffic belongs to.
 194                  */
 195                 if (pvid == VLAN_N_VID)
 196                         goto drop;
 197
 198                 /* PVID is set on this port.  Any untagged or priority-tagged
 199                  * ingress frame is considered to belong to this vlan.
 200                  */
 201                 *vid = pvid;
 202                 if (likely(err))
 203                         /* Untagged Frame. */
 204                         __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), pvid);
 205                 else
 206                         /* Priority-tagged Frame.
 207                          * At this point, We know that skb->vlan_tci had
 208                          * VLAN_TAG_PRESENT bit and its VID field was 0x000.
 209                          * We update only VID field and preserve PCP field.
 210                          */
 211                         skb->vlan_tci |= pvid;
 212
 213                 return true;
 214         }
 215
 216         /* Frame had a valid vlan tag.  See if vlan is allowed */
 217         if (test_bit(*vid, v->vlan_bitmap))
 218                 return true;
 219 drop:
 220         kfree_skb(skb);
 221         return false;
 222 }
 223
 224 /* Called under RCU. */
 225 bool br_allowed_egress(struct net_bridge *br,
 226                        const struct net_port_vlans *v,
 227                        const struct sk_buff *skb)
 228 {
 229         u16 vid;
 230
 231         if (!br->vlan_enabled)
 232                 return true;
 233
 234         if (!v)
 235                 return false;
 236
 237         br_vlan_get_tag(skb, &vid);
 238         if (test_bit(vid, v->vlan_bitmap))
 239                 return true;
 240
 241         return false;
 242 }
 243
 244 /* Called under RCU */
 245 bool br_should_learn(struct net_bridge_port *p, struct sk_buff *skb, u16 *vid)
 246 {
 247         struct net_bridge *br = p->br;
 248         struct net_port_vlans *v;
 249
 250         if (!br->vlan_enabled)
 251                 return true;
 252
 253         v = rcu_dereference(p->vlan_info);
 254         if (!v)
 255                 return false;
 256
 257         br_vlan_get_tag(skb, vid);
 258         if (!*vid) {
 259                 *vid = br_get_pvid(v);
 260                 if (*vid == VLAN_N_VID)
 261                         return false;
 262
 263                 return true;
 264         }
 265
 266         if (test_bit(*vid, v->vlan_bitmap))
 267                 return true;
 268
 269         return false;
 270 }
 271
 272 /* Must be protected by RTNL.
 273  * Must be called with vid in range from 1 to 4094 inclusive.
 274  */
 275 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 276 {
 277         struct net_port_vlans *pv = NULL;
 278         int err;
 279
 280         ASSERT_RTNL();
 281
 282         pv = rtnl_dereference(br->vlan_info);
 283         if (pv)
 284                 return __vlan_add(pv, vid, flags);
 285
 286         /* Create port vlan infomration
 287          */
 288         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 289         if (!pv)
 290                 return -ENOMEM;
 291
 292         pv->parent.br = br;
 293         err = __vlan_add(pv, vid, flags);
 294         if (err)
 295                 goto out;
 296
 297         rcu_assign_pointer(br->vlan_info, pv);
 298         return 0;
 299 out:
 300         kfree(pv);
 301         return err;
 302 }
 303
 304 /* Must be protected by RTNL.
 305  * Must be called with vid in range from 1 to 4094 inclusive.
 306  */
 307 int br_vlan_delete(struct net_bridge *br, u16 vid)
 308 {
 309         struct net_port_vlans *pv;
 310
 311         ASSERT_RTNL();
 312
 313         pv = rtnl_dereference(br->vlan_info);
 314         if (!pv)
 315                 return -EINVAL;
 316
 317         br_fdb_find_delete_local(br, NULL, br->dev->dev_addr, vid);
 318
 319         __vlan_del(pv, vid);
 320         return 0;
 321 }
 322
 323 void br_vlan_flush(struct net_bridge *br)
 324 {
 325         struct net_port_vlans *pv;
 326
 327         ASSERT_RTNL();
 328         pv = rtnl_dereference(br->vlan_info);
 329         if (!pv)
 330                 return;
 331
 332         __vlan_flush(pv);
 333 }
 334
 335 bool br_vlan_find(struct net_bridge *br, u16 vid)
 336 {
 337         struct net_port_vlans *pv;
 338         bool found = false;
 339
 340         rcu_read_lock();
 341         pv = rcu_dereference(br->vlan_info);
 342
 343         if (!pv)
 344                 goto out;
 345
 346         if (test_bit(vid, pv->vlan_bitmap))
 347                 found = true;
 348
 349 out:
 350         rcu_read_unlock();
 351         return found;
 352 }
 353
 354 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 355 {
 356         if (!rtnl_trylock())
 357                 return restart_syscall();
 358
 359         if (br->vlan_enabled == val)
 360                 goto unlock;
 361
 362         br->vlan_enabled = val;
 363
 364 unlock:
 365         rtnl_unlock();
 366         return 0;
 367 }
 368
 369 /* Must be protected by RTNL.
 370  * Must be called with vid in range from 1 to 4094 inclusive.
 371  */
 372 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 373 {
 374         struct net_port_vlans *pv = NULL;
 375         int err;
 376
 377         ASSERT_RTNL();
 378
 379         pv = rtnl_dereference(port->vlan_info);
 380         if (pv)
 381                 return __vlan_add(pv, vid, flags);
 382
 383         /* Create port vlan infomration
 384          */
 385         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 386         if (!pv) {
 387                 err = -ENOMEM;
 388                 goto clean_up;
 389         }
 390
 391         pv->port_idx = port->port_no;
 392         pv->parent.port = port;
 393         err = __vlan_add(pv, vid, flags);
 394         if (err)
 395                 goto clean_up;
 396
 397         rcu_assign_pointer(port->vlan_info, pv);
 398         return 0;
 399
 400 clean_up:
 401         kfree(pv);
 402         return err;
 403 }
 404
 405 /* Must be protected by RTNL.
 406  * Must be called with vid in range from 1 to 4094 inclusive.
 407  */
 408 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 409 {
 410         struct net_port_vlans *pv;
 411
 412         ASSERT_RTNL();
 413
 414         pv = rtnl_dereference(port->vlan_info);
 415         if (!pv)
 416                 return -EINVAL;
 417
 418         br_fdb_find_delete_local(port->br, port, port->dev->dev_addr, vid);
 419
 420         return __vlan_del(pv, vid);
 421 }
 422
 423 void nbp_vlan_flush(struct net_bridge_port *port)
 424 {
 425         struct net_port_vlans *pv;
 426         u16 vid;
 427
 428         ASSERT_RTNL();
 429
 430         pv = rtnl_dereference(port->vlan_info);
 431         if (!pv)
 432                 return;
 433
 434         for_each_set_bit(vid, pv->vlan_bitmap, VLAN_N_VID)
 435                 vlan_vid_del(port->dev, htons(ETH_P_8021Q), vid);
 436
 437         __vlan_flush(pv);
 438 }
 439
 440 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
 441 {
 442         struct net_port_vlans *pv;
 443         bool found = false;
 444
 445         rcu_read_lock();
 446         pv = rcu_dereference(port->vlan_info);
 447
 448         if (!pv)
 449                 goto out;
 450
 451         if (test_bit(vid, pv->vlan_bitmap))
 452                 found = true;
 453
 454 out:
 455         rcu_read_unlock();
 456         return found;
 457 }