net/8021q/vlan_core.c

   1 #include <linux/skbuff.h>
   2 #include <linux/netdevice.h>
   3 #include <linux/if_vlan.h>
   4 #include <linux/netpoll.h>
   5 #include <linux/export.h>
   6 #include "vlan.h"
   7
   8 bool vlan_do_receive(struct sk_buff **skbp)
   9 {
  10         struct sk_buff *skb = *skbp;
  11         __be16 vlan_proto = skb->vlan_proto;
  12         u16 vlan_id = vlan_tx_tag_get_id(skb);
  13         struct net_device *vlan_dev;
  14         struct vlan_pcpu_stats *rx_stats;
  15
  16         vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
  17         if (!vlan_dev)
  18                 return false;
  19
  20         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  21         if (unlikely(!skb))
  22                 return false;
  23
  24         skb->dev = vlan_dev;
  25         if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
  26                 /* Our lower layer thinks this is not local, let's make sure.
  27                  * This allows the VLAN to have a different MAC than the
  28                  * underlying device, and still route correctly. */
  29                 if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
  30                         skb->pkt_type = PACKET_HOST;
  31         }
  32
  33         if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
  34                 unsigned int offset = skb->data - skb_mac_header(skb);
  35
  36                 /*
  37                  * vlan_insert_tag expect skb->data pointing to mac header.
  38                  * So change skb->data before calling it and change back to
  39                  * original position later
  40                  */
  41                 skb_push(skb, offset);
  42                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_proto,
  43                                               skb->vlan_tci);
  44                 if (!skb)
  45                         return false;
  46                 skb_pull(skb, offset + VLAN_HLEN);
  47                 skb_reset_mac_len(skb);
  48         }
  49
  50         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  51         skb->vlan_tci = 0;
  52
  53         rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
  54
  55         u64_stats_update_begin(&rx_stats->syncp);
  56         rx_stats->rx_packets++;
  57         rx_stats->rx_bytes += skb->len;
  58         if (skb->pkt_type == PACKET_MULTICAST)
  59                 rx_stats->rx_multicast++;
  60         u64_stats_update_end(&rx_stats->syncp);
  61
  62         return true;
  63 }
  64
  65 /* Must be invoked with rcu_read_lock. */
  66 struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
  67                                         __be16 vlan_proto, u16 vlan_id)
  68 {
  69         struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
  70
  71         if (vlan_info) {
  72                 return vlan_group_get_device(&vlan_info->grp,
  73                                              vlan_proto, vlan_id);
  74         } else {
  75                 /*
  76                  * Lower devices of master uppers (bonding, team) do not have
  77                  * grp assigned to themselves. Grp is assigned to upper device
  78                  * instead.
  79                  */
  80                 struct net_device *upper_dev;
  81
  82                 upper_dev = netdev_master_upper_dev_get_rcu(dev);
  83                 if (upper_dev)
  84                         return __vlan_find_dev_deep_rcu(upper_dev,
  85                                                     vlan_proto, vlan_id);
  86         }
  87
  88         return NULL;
  89 }
  90 EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
  91
  92 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  93 {
  94         struct net_device *ret = vlan_dev_priv(dev)->real_dev;
  95
  96         while (is_vlan_dev(ret))
  97                 ret = vlan_dev_priv(ret)->real_dev;
  98
  99         return ret;
 100 }
 101 EXPORT_SYMBOL(vlan_dev_real_dev);
 102
 103 u16 vlan_dev_vlan_id(const struct net_device *dev)
 104 {
 105         return vlan_dev_priv(dev)->vlan_id;
 106 }
 107 EXPORT_SYMBOL(vlan_dev_vlan_id);
 108
 109 __be16 vlan_dev_vlan_proto(const struct net_device *dev)
 110 {
 111         return vlan_dev_priv(dev)->vlan_proto;
 112 }
 113 EXPORT_SYMBOL(vlan_dev_vlan_proto);
 114
 115 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 116 {
 117         if (skb_cow(skb, skb_headroom(skb)) < 0)
 118                 return NULL;
 119         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 120         skb->mac_header += VLAN_HLEN;
 121         return skb;
 122 }
 123
 124 struct sk_buff *vlan_untag(struct sk_buff *skb)
 125 {
 126         struct vlan_hdr *vhdr;
 127         u16 vlan_tci;
 128
 129         if (unlikely(vlan_tx_tag_present(skb))) {
 130                 /* vlan_tci is already set-up so leave this for another time */
 131                 return skb;
 132         }
 133
 134         skb = skb_share_check(skb, GFP_ATOMIC);
 135         if (unlikely(!skb))
 136                 goto err_free;
 137
 138         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 139                 goto err_free;
 140
 141         vhdr = (struct vlan_hdr *) skb->data;
 142         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 143         __vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
 144
 145         skb_pull_rcsum(skb, VLAN_HLEN);
 146         vlan_set_encap_proto(skb, vhdr);
 147
 148         skb = vlan_reorder_header(skb);
 149         if (unlikely(!skb))
 150                 goto err_free;
 151
 152         skb_reset_network_header(skb);
 153         skb_reset_transport_header(skb);
 154         skb_reset_mac_len(skb);
 155
 156         return skb;
 157
 158 err_free:
 159         kfree_skb(skb);
 160         return NULL;
 161 }
 162 EXPORT_SYMBOL(vlan_untag);
 163
 164
 165 /*
 166  * vlan info and vid list
 167  */
 168
 169 static void vlan_group_free(struct vlan_group *grp)
 170 {
 171         int i, j;
 172
 173         for (i = 0; i < VLAN_PROTO_NUM; i++)
 174                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 175                         kfree(grp->vlan_devices_arrays[i][j]);
 176 }
 177
 178 static void vlan_info_free(struct vlan_info *vlan_info)
 179 {
 180         vlan_group_free(&vlan_info->grp);
 181         kfree(vlan_info);
 182 }
 183
 184 static void vlan_info_rcu_free(struct rcu_head *rcu)
 185 {
 186         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 187 }
 188
 189 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 190 {
 191         struct vlan_info *vlan_info;
 192
 193         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 194         if (!vlan_info)
 195                 return NULL;
 196
 197         vlan_info->real_dev = dev;
 198         INIT_LIST_HEAD(&vlan_info->vid_list);
 199         return vlan_info;
 200 }
 201
 202 struct vlan_vid_info {
 203         struct list_head list;
 204         __be16 proto;
 205         u16 vid;
 206         int refcount;
 207 };
 208
 209 static bool vlan_hw_filter_capable(const struct net_device *dev,
 210                                      const struct vlan_vid_info *vid_info)
 211 {
 212         if (vid_info->proto == htons(ETH_P_8021Q) &&
 213             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 214                 return true;
 215         if (vid_info->proto == htons(ETH_P_8021AD) &&
 216             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 217                 return true;
 218         return false;
 219 }
 220
 221 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 222                                                __be16 proto, u16 vid)
 223 {
 224         struct vlan_vid_info *vid_info;
 225
 226         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 227                 if (vid_info->proto == proto && vid_info->vid == vid)
 228                         return vid_info;
 229         }
 230         return NULL;
 231 }
 232
 233 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 234 {
 235         struct vlan_vid_info *vid_info;
 236
 237         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 238         if (!vid_info)
 239                 return NULL;
 240         vid_info->proto = proto;
 241         vid_info->vid = vid;
 242
 243         return vid_info;
 244 }
 245
 246 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 247                           struct vlan_vid_info **pvid_info)
 248 {
 249         struct net_device *dev = vlan_info->real_dev;
 250         const struct net_device_ops *ops = dev->netdev_ops;
 251         struct vlan_vid_info *vid_info;
 252         int err;
 253
 254         vid_info = vlan_vid_info_alloc(proto, vid);
 255         if (!vid_info)
 256                 return -ENOMEM;
 257
 258         if (vlan_hw_filter_capable(dev, vid_info)) {
 259                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 260                 if (err) {
 261                         kfree(vid_info);
 262                         return err;
 263                 }
 264         }
 265         list_add(&vid_info->list, &vlan_info->vid_list);
 266         vlan_info->nr_vids++;
 267         *pvid_info = vid_info;
 268         return 0;
 269 }
 270
 271 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 272 {
 273         struct vlan_info *vlan_info;
 274         struct vlan_vid_info *vid_info;
 275         bool vlan_info_created = false;
 276         int err;
 277
 278         ASSERT_RTNL();
 279
 280         vlan_info = rtnl_dereference(dev->vlan_info);
 281         if (!vlan_info) {
 282                 vlan_info = vlan_info_alloc(dev);
 283                 if (!vlan_info)
 284                         return -ENOMEM;
 285                 vlan_info_created = true;
 286         }
 287         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 288         if (!vid_info) {
 289                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 290                 if (err)
 291                         goto out_free_vlan_info;
 292         }
 293         vid_info->refcount++;
 294
 295         if (vlan_info_created)
 296                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 297
 298         return 0;
 299
 300 out_free_vlan_info:
 301         if (vlan_info_created)
 302                 kfree(vlan_info);
 303         return err;
 304 }
 305 EXPORT_SYMBOL(vlan_vid_add);
 306
 307 static void __vlan_vid_del(struct vlan_info *vlan_info,
 308                            struct vlan_vid_info *vid_info)
 309 {
 310         struct net_device *dev = vlan_info->real_dev;
 311         const struct net_device_ops *ops = dev->netdev_ops;
 312         __be16 proto = vid_info->proto;
 313         u16 vid = vid_info->vid;
 314         int err;
 315
 316         if (vlan_hw_filter_capable(dev, vid_info)) {
 317                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 318                 if (err) {
 319                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 320                                 proto, vid, dev->name);
 321                 }
 322         }
 323         list_del(&vid_info->list);
 324         kfree(vid_info);
 325         vlan_info->nr_vids--;
 326 }
 327
 328 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 329 {
 330         struct vlan_info *vlan_info;
 331         struct vlan_vid_info *vid_info;
 332
 333         ASSERT_RTNL();
 334
 335         vlan_info = rtnl_dereference(dev->vlan_info);
 336         if (!vlan_info)
 337                 return;
 338
 339         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 340         if (!vid_info)
 341                 return;
 342         vid_info->refcount--;
 343         if (vid_info->refcount == 0) {
 344                 __vlan_vid_del(vlan_info, vid_info);
 345                 if (vlan_info->nr_vids == 0) {
 346                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 347                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 348                 }
 349         }
 350 }
 351 EXPORT_SYMBOL(vlan_vid_del);
 352
 353 int vlan_vids_add_by_dev(struct net_device *dev,
 354                          const struct net_device *by_dev)
 355 {
 356         struct vlan_vid_info *vid_info;
 357         struct vlan_info *vlan_info;
 358         int err;
 359
 360         ASSERT_RTNL();
 361
 362         vlan_info = rtnl_dereference(by_dev->vlan_info);
 363         if (!vlan_info)
 364                 return 0;
 365
 366         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 367                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 368                 if (err)
 369                         goto unwind;
 370         }
 371         return 0;
 372
 373 unwind:
 374         list_for_each_entry_continue_reverse(vid_info,
 375                                              &vlan_info->vid_list,
 376                                              list) {
 377                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 378         }
 379
 380         return err;
 381 }
 382 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 383
 384 void vlan_vids_del_by_dev(struct net_device *dev,
 385                           const struct net_device *by_dev)
 386 {
 387         struct vlan_vid_info *vid_info;
 388         struct vlan_info *vlan_info;
 389
 390         ASSERT_RTNL();
 391
 392         vlan_info = rtnl_dereference(by_dev->vlan_info);
 393         if (!vlan_info)
 394                 return;
 395
 396         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 397                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 398 }
 399 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 400
 401 bool vlan_uses_dev(const struct net_device *dev)
 402 {
 403         struct vlan_info *vlan_info;
 404
 405         ASSERT_RTNL();
 406
 407         vlan_info = rtnl_dereference(dev->vlan_info);
 408         if (!vlan_info)
 409                 return false;
 410         return vlan_info->grp.nr_vlan_devs ? true : false;
 411 }
 412 EXPORT_SYMBOL(vlan_uses_dev);