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