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, bool last_handler)
   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                 /* Only the last call to vlan_do_receive() should change
  18                  * pkt_type to PACKET_OTHERHOST
  19                  */
  20                 if (vlan_id && last_handler)
  21                         skb->pkt_type = PACKET_OTHERHOST;
  22                 return false;
  23         }
  24
  25         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  26         if (unlikely(!skb))
  27                 return false;
  28
  29         skb->dev = vlan_dev;
  30         if (skb->pkt_type == PACKET_OTHERHOST) {
  31                 /* Our lower layer thinks this is not local, let's make sure.
  32                  * This allows the VLAN to have a different MAC than the
  33                  * underlying device, and still route correctly. */
  34                 if (ether_addr_equal(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
  35                         skb->pkt_type = PACKET_HOST;
  36         }
  37
  38         if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
  39                 unsigned int offset = skb->data - skb_mac_header(skb);
  40
  41                 /*
  42                  * vlan_insert_tag expect skb->data pointing to mac header.
  43                  * So change skb->data before calling it and change back to
  44                  * original position later
  45                  */
  46                 skb_push(skb, offset);
  47                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
  48                 if (!skb)
  49                         return false;
  50                 skb_pull(skb, offset + VLAN_HLEN);
  51                 skb_reset_mac_len(skb);
  52         }
  53
  54         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  55         skb->vlan_tci = 0;
  56
  57         rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
  58
  59         u64_stats_update_begin(&rx_stats->syncp);
  60         rx_stats->rx_packets++;
  61         rx_stats->rx_bytes += skb->len;
  62         if (skb->pkt_type == PACKET_MULTICAST)
  63                 rx_stats->rx_multicast++;
  64         u64_stats_update_end(&rx_stats->syncp);
  65
  66         return true;
  67 }
  68
  69 /* Must be invoked with rcu_read_lock or with RTNL. */
  70 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  71                                         u16 vlan_id)
  72 {
  73         struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
  74
  75         if (vlan_info) {
  76                 return vlan_group_get_device(&vlan_info->grp, vlan_id);
  77         } else {
  78                 /*
  79                  * Bonding slaves do not have grp assigned to themselves.
  80                  * Grp is assigned to bonding master instead.
  81                  */
  82                 if (netif_is_bond_slave(real_dev))
  83                         return __vlan_find_dev_deep(real_dev->master, vlan_id);
  84         }
  85
  86         return NULL;
  87 }
  88 EXPORT_SYMBOL(__vlan_find_dev_deep);
  89
  90 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  91 {
  92         return vlan_dev_priv(dev)->real_dev;
  93 }
  94 EXPORT_SYMBOL(vlan_dev_real_dev);
  95
  96 u16 vlan_dev_vlan_id(const struct net_device *dev)
  97 {
  98         return vlan_dev_priv(dev)->vlan_id;
  99 }
 100 EXPORT_SYMBOL(vlan_dev_vlan_id);
 101
 102 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 103 {
 104         if (skb_cow(skb, skb_headroom(skb)) < 0)
 105                 return NULL;
 106         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 107         skb->mac_header += VLAN_HLEN;
 108         skb_reset_mac_len(skb);
 109         return skb;
 110 }
 111
 112 struct sk_buff *vlan_untag(struct sk_buff *skb)
 113 {
 114         struct vlan_hdr *vhdr;
 115         u16 vlan_tci;
 116
 117         if (unlikely(vlan_tx_tag_present(skb))) {
 118                 /* vlan_tci is already set-up so leave this for another time */
 119                 return skb;
 120         }
 121
 122         skb = skb_share_check(skb, GFP_ATOMIC);
 123         if (unlikely(!skb))
 124                 goto err_free;
 125
 126         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 127                 goto err_free;
 128
 129         vhdr = (struct vlan_hdr *) skb->data;
 130         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 131         __vlan_hwaccel_put_tag(skb, vlan_tci);
 132
 133         skb_pull_rcsum(skb, VLAN_HLEN);
 134         vlan_set_encap_proto(skb, vhdr);
 135
 136         skb = vlan_reorder_header(skb);
 137         if (unlikely(!skb))
 138                 goto err_free;
 139
 140         skb_reset_network_header(skb);
 141         skb_reset_transport_header(skb);
 142         return skb;
 143
 144 err_free:
 145         kfree_skb(skb);
 146         return NULL;
 147 }
 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             ops->ndo_vlan_rx_add_vid) {
 230                 err =  ops->ndo_vlan_rx_add_vid(dev, vid);
 231                 if (err) {
 232                         kfree(vid_info);
 233                         return err;
 234                 }
 235         }
 236         list_add(&vid_info->list, &vlan_info->vid_list);
 237         vlan_info->nr_vids++;
 238         *pvid_info = vid_info;
 239         return 0;
 240 }
 241
 242 int vlan_vid_add(struct net_device *dev, unsigned short vid)
 243 {
 244         struct vlan_info *vlan_info;
 245         struct vlan_vid_info *vid_info;
 246         bool vlan_info_created = false;
 247         int err;
 248
 249         ASSERT_RTNL();
 250
 251         vlan_info = rtnl_dereference(dev->vlan_info);
 252         if (!vlan_info) {
 253                 vlan_info = vlan_info_alloc(dev);
 254                 if (!vlan_info)
 255                         return -ENOMEM;
 256                 vlan_info_created = true;
 257         }
 258         vid_info = vlan_vid_info_get(vlan_info, vid);
 259         if (!vid_info) {
 260                 err = __vlan_vid_add(vlan_info, vid, &vid_info);
 261                 if (err)
 262                         goto out_free_vlan_info;
 263         }
 264         vid_info->refcount++;
 265
 266         if (vlan_info_created)
 267                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 268
 269         return 0;
 270
 271 out_free_vlan_info:
 272         if (vlan_info_created)
 273                 kfree(vlan_info);
 274         return err;
 275 }
 276 EXPORT_SYMBOL(vlan_vid_add);
 277
 278 static void __vlan_vid_del(struct vlan_info *vlan_info,
 279                            struct vlan_vid_info *vid_info)
 280 {
 281         struct net_device *dev = vlan_info->real_dev;
 282         const struct net_device_ops *ops = dev->netdev_ops;
 283         unsigned short vid = vid_info->vid;
 284         int err;
 285
 286         if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 287              ops->ndo_vlan_rx_kill_vid) {
 288                 err = ops->ndo_vlan_rx_kill_vid(dev, vid);
 289                 if (err) {
 290                         pr_warn("failed to kill vid %d for device %s\n",
 291                                 vid, dev->name);
 292                 }
 293         }
 294         list_del(&vid_info->list);
 295         kfree(vid_info);
 296         vlan_info->nr_vids--;
 297 }
 298
 299 void vlan_vid_del(struct net_device *dev, unsigned short vid)
 300 {
 301         struct vlan_info *vlan_info;
 302         struct vlan_vid_info *vid_info;
 303
 304         ASSERT_RTNL();
 305
 306         vlan_info = rtnl_dereference(dev->vlan_info);
 307         if (!vlan_info)
 308                 return;
 309
 310         vid_info = vlan_vid_info_get(vlan_info, vid);
 311         if (!vid_info)
 312                 return;
 313         vid_info->refcount--;
 314         if (vid_info->refcount == 0) {
 315                 __vlan_vid_del(vlan_info, vid_info);
 316                 if (vlan_info->nr_vids == 0) {
 317                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 318                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 319                 }
 320         }
 321 }
 322 EXPORT_SYMBOL(vlan_vid_del);
 323
 324 int vlan_vids_add_by_dev(struct net_device *dev,
 325                          const struct net_device *by_dev)
 326 {
 327         struct vlan_vid_info *vid_info;
 328         struct vlan_info *vlan_info;
 329         int err;
 330
 331         ASSERT_RTNL();
 332
 333         vlan_info = rtnl_dereference(by_dev->vlan_info);
 334         if (!vlan_info)
 335                 return 0;
 336
 337         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 338                 err = vlan_vid_add(dev, vid_info->vid);
 339                 if (err)
 340                         goto unwind;
 341         }
 342         return 0;
 343
 344 unwind:
 345         list_for_each_entry_continue_reverse(vid_info,
 346                                              &vlan_info->vid_list,
 347                                              list) {
 348                 vlan_vid_del(dev, vid_info->vid);
 349         }
 350
 351         return err;
 352 }
 353 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 354
 355 void vlan_vids_del_by_dev(struct net_device *dev,
 356                           const struct net_device *by_dev)
 357 {
 358         struct vlan_vid_info *vid_info;
 359         struct vlan_info *vlan_info;
 360
 361         ASSERT_RTNL();
 362
 363         vlan_info = rtnl_dereference(by_dev->vlan_info);
 364         if (!vlan_info)
 365                 return;
 366
 367         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 368                 vlan_vid_del(dev, vid_info->vid);
 369 }
 370 EXPORT_SYMBOL(vlan_vids_del_by_dev);