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 (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(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(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(upper_dev,
  85                                                     vlan_proto, vlan_id);
  86         }
  87
  88         return NULL;
  89 }
  90 EXPORT_SYMBOL(__vlan_find_dev_deep);
  91
  92 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  93 {
  94         return vlan_dev_priv(dev)->real_dev;
  95 }
  96 EXPORT_SYMBOL(vlan_dev_real_dev);
  97
  98 u16 vlan_dev_vlan_id(const struct net_device *dev)
  99 {
 100         return vlan_dev_priv(dev)->vlan_id;
 101 }
 102 EXPORT_SYMBOL(vlan_dev_vlan_id);
 103
 104 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 105 {
 106         if (skb_cow(skb, skb_headroom(skb)) < 0) {
 107                 kfree_skb(skb);
 108                 return NULL;
 109         }
 110
 111         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 112         skb->mac_header += VLAN_HLEN;
 113         return skb;
 114 }
 115
 116 struct sk_buff *vlan_untag(struct sk_buff *skb)
 117 {
 118         struct vlan_hdr *vhdr;
 119         u16 vlan_tci;
 120
 121         if (unlikely(vlan_tx_tag_present(skb))) {
 122                 /* vlan_tci is already set-up so leave this for another time */
 123                 return skb;
 124         }
 125
 126         skb = skb_share_check(skb, GFP_ATOMIC);
 127         if (unlikely(!skb))
 128                 goto err_free;
 129
 130         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 131                 goto err_free;
 132
 133         vhdr = (struct vlan_hdr *) skb->data;
 134         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 135         __vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
 136
 137         skb_pull_rcsum(skb, VLAN_HLEN);
 138         vlan_set_encap_proto(skb, vhdr);
 139
 140         skb = vlan_reorder_header(skb);
 141         if (unlikely(!skb))
 142                 goto err_free;
 143
 144         skb_reset_network_header(skb);
 145         skb_reset_transport_header(skb);
 146         skb_reset_mac_len(skb);
 147
 148         return skb;
 149
 150 err_free:
 151         kfree_skb(skb);
 152         return NULL;
 153 }
 154 EXPORT_SYMBOL(vlan_untag);
 155
 156
 157 /*
 158  * vlan info and vid list
 159  */
 160
 161 static void vlan_group_free(struct vlan_group *grp)
 162 {
 163         int i, j;
 164
 165         for (i = 0; i < VLAN_PROTO_NUM; i++)
 166                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 167                         kfree(grp->vlan_devices_arrays[i][j]);
 168 }
 169
 170 static void vlan_info_free(struct vlan_info *vlan_info)
 171 {
 172         vlan_group_free(&vlan_info->grp);
 173         kfree(vlan_info);
 174 }
 175
 176 static void vlan_info_rcu_free(struct rcu_head *rcu)
 177 {
 178         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 179 }
 180
 181 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 182 {
 183         struct vlan_info *vlan_info;
 184
 185         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 186         if (!vlan_info)
 187                 return NULL;
 188
 189         vlan_info->real_dev = dev;
 190         INIT_LIST_HEAD(&vlan_info->vid_list);
 191         return vlan_info;
 192 }
 193
 194 struct vlan_vid_info {
 195         struct list_head list;
 196         __be16 proto;
 197         u16 vid;
 198         int refcount;
 199 };
 200
 201 static bool vlan_hw_filter_capable(const struct net_device *dev,
 202                                      const struct vlan_vid_info *vid_info)
 203 {
 204         if (vid_info->proto == htons(ETH_P_8021Q) &&
 205             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 206                 return true;
 207         if (vid_info->proto == htons(ETH_P_8021AD) &&
 208             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 209                 return true;
 210         return false;
 211 }
 212
 213 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 214                                                __be16 proto, u16 vid)
 215 {
 216         struct vlan_vid_info *vid_info;
 217
 218         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 219                 if (vid_info->proto == proto && vid_info->vid == vid)
 220                         return vid_info;
 221         }
 222         return NULL;
 223 }
 224
 225 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 226 {
 227         struct vlan_vid_info *vid_info;
 228
 229         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 230         if (!vid_info)
 231                 return NULL;
 232         vid_info->proto = proto;
 233         vid_info->vid = vid;
 234
 235         return vid_info;
 236 }
 237
 238 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 239                           struct vlan_vid_info **pvid_info)
 240 {
 241         struct net_device *dev = vlan_info->real_dev;
 242         const struct net_device_ops *ops = dev->netdev_ops;
 243         struct vlan_vid_info *vid_info;
 244         int err;
 245
 246         vid_info = vlan_vid_info_alloc(proto, vid);
 247         if (!vid_info)
 248                 return -ENOMEM;
 249
 250         if (vlan_hw_filter_capable(dev, vid_info)) {
 251                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 252                 if (err) {
 253                         kfree(vid_info);
 254                         return err;
 255                 }
 256         }
 257         list_add(&vid_info->list, &vlan_info->vid_list);
 258         vlan_info->nr_vids++;
 259         *pvid_info = vid_info;
 260         return 0;
 261 }
 262
 263 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 264 {
 265         struct vlan_info *vlan_info;
 266         struct vlan_vid_info *vid_info;
 267         bool vlan_info_created = false;
 268         int err;
 269
 270         ASSERT_RTNL();
 271
 272         vlan_info = rtnl_dereference(dev->vlan_info);
 273         if (!vlan_info) {
 274                 vlan_info = vlan_info_alloc(dev);
 275                 if (!vlan_info)
 276                         return -ENOMEM;
 277                 vlan_info_created = true;
 278         }
 279         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 280         if (!vid_info) {
 281                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 282                 if (err)
 283                         goto out_free_vlan_info;
 284         }
 285         vid_info->refcount++;
 286
 287         if (vlan_info_created)
 288                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 289
 290         return 0;
 291
 292 out_free_vlan_info:
 293         if (vlan_info_created)
 294                 kfree(vlan_info);
 295         return err;
 296 }
 297 EXPORT_SYMBOL(vlan_vid_add);
 298
 299 static void __vlan_vid_del(struct vlan_info *vlan_info,
 300                            struct vlan_vid_info *vid_info)
 301 {
 302         struct net_device *dev = vlan_info->real_dev;
 303         const struct net_device_ops *ops = dev->netdev_ops;
 304         __be16 proto = vid_info->proto;
 305         u16 vid = vid_info->vid;
 306         int err;
 307
 308         if (vlan_hw_filter_capable(dev, vid_info)) {
 309                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 310                 if (err) {
 311                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 312                                 proto, vid, dev->name);
 313                 }
 314         }
 315         list_del(&vid_info->list);
 316         kfree(vid_info);
 317         vlan_info->nr_vids--;
 318 }
 319
 320 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 321 {
 322         struct vlan_info *vlan_info;
 323         struct vlan_vid_info *vid_info;
 324
 325         ASSERT_RTNL();
 326
 327         vlan_info = rtnl_dereference(dev->vlan_info);
 328         if (!vlan_info)
 329                 return;
 330
 331         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 332         if (!vid_info)
 333                 return;
 334         vid_info->refcount--;
 335         if (vid_info->refcount == 0) {
 336                 __vlan_vid_del(vlan_info, vid_info);
 337                 if (vlan_info->nr_vids == 0) {
 338                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 339                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 340                 }
 341         }
 342 }
 343 EXPORT_SYMBOL(vlan_vid_del);
 344
 345 int vlan_vids_add_by_dev(struct net_device *dev,
 346                          const struct net_device *by_dev)
 347 {
 348         struct vlan_vid_info *vid_info;
 349         struct vlan_info *vlan_info;
 350         int err;
 351
 352         ASSERT_RTNL();
 353
 354         vlan_info = rtnl_dereference(by_dev->vlan_info);
 355         if (!vlan_info)
 356                 return 0;
 357
 358         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 359                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 360                 if (err)
 361                         goto unwind;
 362         }
 363         return 0;
 364
 365 unwind:
 366         list_for_each_entry_continue_reverse(vid_info,
 367                                              &vlan_info->vid_list,
 368                                              list) {
 369                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 370         }
 371
 372         return err;
 373 }
 374 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 375
 376 void vlan_vids_del_by_dev(struct net_device *dev,
 377                           const struct net_device *by_dev)
 378 {
 379         struct vlan_vid_info *vid_info;
 380         struct vlan_info *vlan_info;
 381
 382         ASSERT_RTNL();
 383
 384         vlan_info = rtnl_dereference(by_dev->vlan_info);
 385         if (!vlan_info)
 386                 return;
 387
 388         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 389                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 390 }
 391 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 392
 393 bool vlan_uses_dev(const struct net_device *dev)
 394 {
 395         struct vlan_info *vlan_info;
 396
 397         ASSERT_RTNL();
 398
 399         vlan_info = rtnl_dereference(dev->vlan_info);
 400         if (!vlan_info)
 401                 return false;
 402         return vlan_info->grp.nr_vlan_devs ? true : false;
 403 }
 404 EXPORT_SYMBOL(vlan_uses_dev);