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 (vid) {
  48                 if (v->port_idx) {
  49                         p = v->parent.port;
  50                         br = p->br;
  51                         dev = p->dev;
  52                 } else {
  53                         br = v->parent.br;
  54                         dev = br->dev;
  55                 }
  56
  57                 if (p && (dev->features & NETIF_F_HW_VLAN_FILTER)) {
  58                         /* Add VLAN to the device filter if it is supported.
  59                          * Stricly speaking, this is not necessary now, since
  60                          * devices are made promiscuous by the bridge, but if
  61                          * that ever changes this code will allow tagged
  62                          * traffic to enter the bridge.
  63                          */
  64                         err = dev->netdev_ops->ndo_vlan_rx_add_vid(dev, vid);
  65                         if (err)
  66                                 return err;
  67                 }
  68
  69                 err = br_fdb_insert(br, p, dev->dev_addr, vid);
  70                 if (err) {
  71                         br_err(br, "failed insert local address into bridge "
  72                                "forwarding table\n");
  73                         goto out_filt;
  74                 }
  75
  76         }
  77
  78         set_bit(vid, v->vlan_bitmap);
  79         v->num_vlans++;
  80         __vlan_add_flags(v, vid, flags);
  81
  82         return 0;
  83
  84 out_filt:
  85         if (p && (dev->features & NETIF_F_HW_VLAN_FILTER))
  86                 dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
  87         return err;
  88 }
  89
  90 static int __vlan_del(struct net_port_vlans *v, u16 vid)
  91 {
  92         if (!test_bit(vid, v->vlan_bitmap))
  93                 return -EINVAL;
  94
  95         __vlan_delete_pvid(v, vid);
  96         clear_bit(vid, v->untagged_bitmap);
  97
  98         if (v->port_idx && vid) {
  99                 struct net_device *dev = v->parent.port->dev;
 100
 101                 if (dev->features & NETIF_F_HW_VLAN_FILTER)
 102                         dev->netdev_ops->ndo_vlan_rx_kill_vid(dev, vid);
 103         }
 104
 105         clear_bit(vid, v->vlan_bitmap);
 106         v->num_vlans--;
 107         if (bitmap_empty(v->vlan_bitmap, BR_VLAN_BITMAP_LEN)) {
 108                 if (v->port_idx)
 109                         rcu_assign_pointer(v->parent.port->vlan_info, NULL);
 110                 else
 111                         rcu_assign_pointer(v->parent.br->vlan_info, NULL);
 112                 kfree_rcu(v, rcu);
 113         }
 114         return 0;
 115 }
 116
 117 static void __vlan_flush(struct net_port_vlans *v)
 118 {
 119         smp_wmb();
 120         v->pvid = 0;
 121         bitmap_zero(v->vlan_bitmap, BR_VLAN_BITMAP_LEN);
 122         if (v->port_idx)
 123                 rcu_assign_pointer(v->parent.port->vlan_info, NULL);
 124         else
 125                 rcu_assign_pointer(v->parent.br->vlan_info, NULL);
 126         kfree_rcu(v, rcu);
 127 }
 128
 129 /* Strip the tag from the packet.  Will return skb with tci set 0.  */
 130 static struct sk_buff *br_vlan_untag(struct sk_buff *skb)
 131 {
 132         if (skb->protocol != htons(ETH_P_8021Q)) {
 133                 skb->vlan_tci = 0;
 134                 return skb;
 135         }
 136
 137         skb->vlan_tci = 0;
 138         skb = vlan_untag(skb);
 139         if (skb)
 140                 skb->vlan_tci = 0;
 141
 142         return skb;
 143 }
 144
 145 struct sk_buff *br_handle_vlan(struct net_bridge *br,
 146                                const struct net_port_vlans *pv,
 147                                struct sk_buff *skb)
 148 {
 149         u16 vid;
 150
 151         if (!br->vlan_enabled)
 152                 goto out;
 153
 154         /* At this point, we know that the frame was filtered and contains
 155          * a valid vlan id.  If the vlan id is set in the untagged bitmap,
 156          * send untagged; otherwise, send taged.
 157          */
 158         br_vlan_get_tag(skb, &vid);
 159         if (test_bit(vid, pv->untagged_bitmap))
 160                 skb = br_vlan_untag(skb);
 161         else {
 162                 /* Egress policy says "send tagged".  If output device
 163                  * is the  bridge, we need to add the VLAN header
 164                  * ourselves since we'll be going through the RX path.
 165                  * Sending to ports puts the frame on the TX path and
 166                  * we let dev_hard_start_xmit() add the header.
 167                  */
 168                 if (skb->protocol != htons(ETH_P_8021Q) &&
 169                     pv->port_idx == 0) {
 170                         /* vlan_put_tag expects skb->data to point to
 171                          * mac header.
 172                          */
 173                         skb_push(skb, ETH_HLEN);
 174                         skb = __vlan_put_tag(skb, skb->vlan_tci);
 175                         if (!skb)
 176                                 goto out;
 177                         /* put skb->data back to where it was */
 178                         skb_pull(skb, ETH_HLEN);
 179                         skb->vlan_tci = 0;
 180                 }
 181         }
 182
 183 out:
 184         return skb;
 185 }
 186
 187 /* Called under RCU */
 188 bool br_allowed_ingress(struct net_bridge *br, struct net_port_vlans *v,
 189                         struct sk_buff *skb, u16 *vid)
 190 {
 191         /* If VLAN filtering is disabled on the bridge, all packets are
 192          * permitted.
 193          */
 194         if (!br->vlan_enabled)
 195                 return true;
 196
 197         /* If there are no vlan in the permitted list, all packets are
 198          * rejected.
 199          */
 200         if (!v)
 201                 return false;
 202
 203         if (br_vlan_get_tag(skb, vid)) {
 204                 u16 pvid = br_get_pvid(v);
 205
 206                 /* Frame did not have a tag.  See if pvid is set
 207                  * on this port.  That tells us which vlan untagged
 208                  * traffic belongs to.
 209                  */
 210                 if (pvid == VLAN_N_VID)
 211                         return false;
 212
 213                 /* PVID is set on this port.  Any untagged ingress
 214                  * frame is considered to belong to this vlan.
 215                  */
 216                 __vlan_hwaccel_put_tag(skb, pvid);
 217                 return true;
 218         }
 219
 220         /* Frame had a valid vlan tag.  See if vlan is allowed */
 221         if (test_bit(*vid, v->vlan_bitmap))
 222                 return true;
 223
 224         return false;
 225 }
 226
 227 /* Called under RCU. */
 228 bool br_allowed_egress(struct net_bridge *br,
 229                        const struct net_port_vlans *v,
 230                        const struct sk_buff *skb)
 231 {
 232         u16 vid;
 233
 234         if (!br->vlan_enabled)
 235                 return true;
 236
 237         if (!v)
 238                 return false;
 239
 240         br_vlan_get_tag(skb, &vid);
 241         if (test_bit(vid, v->vlan_bitmap))
 242                 return true;
 243
 244         return false;
 245 }
 246
 247 /* Must be protected by RTNL */
 248 int br_vlan_add(struct net_bridge *br, u16 vid, u16 flags)
 249 {
 250         struct net_port_vlans *pv = NULL;
 251         int err;
 252
 253         ASSERT_RTNL();
 254
 255         pv = rtnl_dereference(br->vlan_info);
 256         if (pv)
 257                 return __vlan_add(pv, vid, flags);
 258
 259         /* Create port vlan infomration
 260          */
 261         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 262         if (!pv)
 263                 return -ENOMEM;
 264
 265         pv->parent.br = br;
 266         err = __vlan_add(pv, vid, flags);
 267         if (err)
 268                 goto out;
 269
 270         rcu_assign_pointer(br->vlan_info, pv);
 271         return 0;
 272 out:
 273         kfree(pv);
 274         return err;
 275 }
 276
 277 /* Must be protected by RTNL */
 278 int br_vlan_delete(struct net_bridge *br, u16 vid)
 279 {
 280         struct net_port_vlans *pv;
 281
 282         ASSERT_RTNL();
 283
 284         pv = rtnl_dereference(br->vlan_info);
 285         if (!pv)
 286                 return -EINVAL;
 287
 288         if (vid) {
 289                 /* If the VID !=0 remove fdb for this vid. VID 0 is special
 290                  * in that it's the default and is always there in the fdb.
 291                  */
 292                 spin_lock_bh(&br->hash_lock);
 293                 fdb_delete_by_addr(br, br->dev->dev_addr, vid);
 294                 spin_unlock_bh(&br->hash_lock);
 295         }
 296
 297         __vlan_del(pv, vid);
 298         return 0;
 299 }
 300
 301 void br_vlan_flush(struct net_bridge *br)
 302 {
 303         struct net_port_vlans *pv;
 304
 305         ASSERT_RTNL();
 306         pv = rtnl_dereference(br->vlan_info);
 307         if (!pv)
 308                 return;
 309
 310         __vlan_flush(pv);
 311 }
 312
 313 int br_vlan_filter_toggle(struct net_bridge *br, unsigned long val)
 314 {
 315         if (!rtnl_trylock())
 316                 return restart_syscall();
 317
 318         if (br->vlan_enabled == val)
 319                 goto unlock;
 320
 321         br->vlan_enabled = val;
 322
 323 unlock:
 324         rtnl_unlock();
 325         return 0;
 326 }
 327
 328 /* Must be protected by RTNL */
 329 int nbp_vlan_add(struct net_bridge_port *port, u16 vid, u16 flags)
 330 {
 331         struct net_port_vlans *pv = NULL;
 332         int err;
 333
 334         ASSERT_RTNL();
 335
 336         pv = rtnl_dereference(port->vlan_info);
 337         if (pv)
 338                 return __vlan_add(pv, vid, flags);
 339
 340         /* Create port vlan infomration
 341          */
 342         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 343         if (!pv) {
 344                 err = -ENOMEM;
 345                 goto clean_up;
 346         }
 347
 348         pv->port_idx = port->port_no;
 349         pv->parent.port = port;
 350         err = __vlan_add(pv, vid, flags);
 351         if (err)
 352                 goto clean_up;
 353
 354         rcu_assign_pointer(port->vlan_info, pv);
 355         return 0;
 356
 357 clean_up:
 358         kfree(pv);
 359         return err;
 360 }
 361
 362 /* Must be protected by RTNL */
 363 int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 364 {
 365         struct net_port_vlans *pv;
 366
 367         ASSERT_RTNL();
 368
 369         pv = rtnl_dereference(port->vlan_info);
 370         if (!pv)
 371                 return -EINVAL;
 372
 373         if (vid) {
 374                 /* If the VID !=0 remove fdb for this vid. VID 0 is special
 375                  * in that it's the default and is always there in the fdb.
 376                  */
 377                 spin_lock_bh(&port->br->hash_lock);
 378                 fdb_delete_by_addr(port->br, port->dev->dev_addr, vid);
 379                 spin_unlock_bh(&port->br->hash_lock);
 380         }
 381
 382         return __vlan_del(pv, vid);
 383 }
 384
 385 void nbp_vlan_flush(struct net_bridge_port *port)
 386 {
 387         struct net_port_vlans *pv;
 388
 389         ASSERT_RTNL();
 390
 391         pv = rtnl_dereference(port->vlan_info);
 392         if (!pv)
 393                 return;
 394
 395         __vlan_flush(pv);
 396 }
 397
 398 bool nbp_vlan_find(struct net_bridge_port *port, u16 vid)
 399 {
 400         struct net_port_vlans *pv;
 401         bool found = false;
 402
 403         rcu_read_lock();
 404         pv = rcu_dereference(port->vlan_info);
 405
 406         if (!pv)
 407                 goto out;
 408
 409         if (test_bit(vid, pv->vlan_bitmap))
 410                 found = true;
 411
 412 out:
 413         rcu_read_unlock();
 414         return found;
 415 }