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 or with RTNL. */
  64 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  65                                         u16 vlan_id)
  66 {
  67         struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
  68
  69         if (vlan_info) {
  70                 return vlan_group_get_device(&vlan_info->grp, vlan_id);
  71         } else {
  72                 /*
  73                  * Bonding slaves do not have grp assigned to themselves.
  74                  * Grp is assigned to bonding master instead.
  75                  */
  76                 if (netif_is_bond_slave(real_dev))
  77                         return __vlan_find_dev_deep(real_dev->master, vlan_id);
  78         }
  79
  80         return NULL;
  81 }
  82 EXPORT_SYMBOL(__vlan_find_dev_deep);
  83
  84 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  85 {
  86         return vlan_dev_priv(dev)->real_dev;
  87 }
  88 EXPORT_SYMBOL(vlan_dev_real_dev);
  89
  90 u16 vlan_dev_vlan_id(const struct net_device *dev)
  91 {
  92         return vlan_dev_priv(dev)->vlan_id;
  93 }
  94 EXPORT_SYMBOL(vlan_dev_vlan_id);
  95
  96 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
  97 {
  98         if (skb_cow(skb, skb_headroom(skb)) < 0)
  99                 return NULL;
 100         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 101         skb->mac_header += VLAN_HLEN;
 102         return skb;
 103 }
 104
 105 struct sk_buff *vlan_untag(struct sk_buff *skb)
 106 {
 107         struct vlan_hdr *vhdr;
 108         u16 vlan_tci;
 109
 110         if (unlikely(vlan_tx_tag_present(skb))) {
 111                 /* vlan_tci is already set-up so leave this for another time */
 112                 return skb;
 113         }
 114
 115         skb = skb_share_check(skb, GFP_ATOMIC);
 116         if (unlikely(!skb))
 117                 goto err_free;
 118
 119         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 120                 goto err_free;
 121
 122         vhdr = (struct vlan_hdr *) skb->data;
 123         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 124         __vlan_hwaccel_put_tag(skb, vlan_tci);
 125
 126         skb_pull_rcsum(skb, VLAN_HLEN);
 127         vlan_set_encap_proto(skb, vhdr);
 128
 129         skb = vlan_reorder_header(skb);
 130         if (unlikely(!skb))
 131                 goto err_free;
 132
 133         skb_reset_network_header(skb);
 134         skb_reset_transport_header(skb);
 135         skb_reset_mac_len(skb);
 136
 137         return skb;
 138
 139 err_free:
 140         kfree_skb(skb);
 141         return NULL;
 142 }
 143
 144
 145 /*
 146  * vlan info and vid list
 147  */
 148
 149 static void vlan_group_free(struct vlan_group *grp)
 150 {
 151         int i;
 152
 153         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
 154                 kfree(grp->vlan_devices_arrays[i]);
 155 }
 156
 157 static void vlan_info_free(struct vlan_info *vlan_info)
 158 {
 159         vlan_group_free(&vlan_info->grp);
 160         kfree(vlan_info);
 161 }
 162
 163 static void vlan_info_rcu_free(struct rcu_head *rcu)
 164 {
 165         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 166 }
 167
 168 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 169 {
 170         struct vlan_info *vlan_info;
 171
 172         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 173         if (!vlan_info)
 174                 return NULL;
 175
 176         vlan_info->real_dev = dev;
 177         INIT_LIST_HEAD(&vlan_info->vid_list);
 178         return vlan_info;
 179 }
 180
 181 struct vlan_vid_info {
 182         struct list_head list;
 183         unsigned short vid;
 184         int refcount;
 185 };
 186
 187 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 188                                                unsigned short vid)
 189 {
 190         struct vlan_vid_info *vid_info;
 191
 192         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 193                 if (vid_info->vid == vid)
 194                         return vid_info;
 195         }
 196         return NULL;
 197 }
 198
 199 static struct vlan_vid_info *vlan_vid_info_alloc(unsigned short vid)
 200 {
 201         struct vlan_vid_info *vid_info;
 202
 203         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 204         if (!vid_info)
 205                 return NULL;
 206         vid_info->vid = vid;
 207
 208         return vid_info;
 209 }
 210
 211 static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
 212                           struct vlan_vid_info **pvid_info)
 213 {
 214         struct net_device *dev = vlan_info->real_dev;
 215         const struct net_device_ops *ops = dev->netdev_ops;
 216         struct vlan_vid_info *vid_info;
 217         int err;
 218
 219         vid_info = vlan_vid_info_alloc(vid);
 220         if (!vid_info)
 221                 return -ENOMEM;
 222
 223         if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 224             ops->ndo_vlan_rx_add_vid) {
 225                 err =  ops->ndo_vlan_rx_add_vid(dev, vid);
 226                 if (err) {
 227                         kfree(vid_info);
 228                         return err;
 229                 }
 230         }
 231         list_add(&vid_info->list, &vlan_info->vid_list);
 232         vlan_info->nr_vids++;
 233         *pvid_info = vid_info;
 234         return 0;
 235 }
 236
 237 int vlan_vid_add(struct net_device *dev, unsigned short vid)
 238 {
 239         struct vlan_info *vlan_info;
 240         struct vlan_vid_info *vid_info;
 241         bool vlan_info_created = false;
 242         int err;
 243
 244         ASSERT_RTNL();
 245
 246         vlan_info = rtnl_dereference(dev->vlan_info);
 247         if (!vlan_info) {
 248                 vlan_info = vlan_info_alloc(dev);
 249                 if (!vlan_info)
 250                         return -ENOMEM;
 251                 vlan_info_created = true;
 252         }
 253         vid_info = vlan_vid_info_get(vlan_info, vid);
 254         if (!vid_info) {
 255                 err = __vlan_vid_add(vlan_info, vid, &vid_info);
 256                 if (err)
 257                         goto out_free_vlan_info;
 258         }
 259         vid_info->refcount++;
 260
 261         if (vlan_info_created)
 262                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 263
 264         return 0;
 265
 266 out_free_vlan_info:
 267         if (vlan_info_created)
 268                 kfree(vlan_info);
 269         return err;
 270 }
 271 EXPORT_SYMBOL(vlan_vid_add);
 272
 273 static void __vlan_vid_del(struct vlan_info *vlan_info,
 274                            struct vlan_vid_info *vid_info)
 275 {
 276         struct net_device *dev = vlan_info->real_dev;
 277         const struct net_device_ops *ops = dev->netdev_ops;
 278         unsigned short vid = vid_info->vid;
 279         int err;
 280
 281         if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 282              ops->ndo_vlan_rx_kill_vid) {
 283                 err = ops->ndo_vlan_rx_kill_vid(dev, vid);
 284                 if (err) {
 285                         pr_warn("failed to kill vid %d for device %s\n",
 286                                 vid, dev->name);
 287                 }
 288         }
 289         list_del(&vid_info->list);
 290         kfree(vid_info);
 291         vlan_info->nr_vids--;
 292 }
 293
 294 void vlan_vid_del(struct net_device *dev, unsigned short vid)
 295 {
 296         struct vlan_info *vlan_info;
 297         struct vlan_vid_info *vid_info;
 298
 299         ASSERT_RTNL();
 300
 301         vlan_info = rtnl_dereference(dev->vlan_info);
 302         if (!vlan_info)
 303                 return;
 304
 305         vid_info = vlan_vid_info_get(vlan_info, vid);
 306         if (!vid_info)
 307                 return;
 308         vid_info->refcount--;
 309         if (vid_info->refcount == 0) {
 310                 __vlan_vid_del(vlan_info, vid_info);
 311                 if (vlan_info->nr_vids == 0) {
 312                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 313                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 314                 }
 315         }
 316 }
 317 EXPORT_SYMBOL(vlan_vid_del);
 318
 319 int vlan_vids_add_by_dev(struct net_device *dev,
 320                          const struct net_device *by_dev)
 321 {
 322         struct vlan_vid_info *vid_info;
 323         struct vlan_info *vlan_info;
 324         int err;
 325
 326         ASSERT_RTNL();
 327
 328         vlan_info = rtnl_dereference(by_dev->vlan_info);
 329         if (!vlan_info)
 330                 return 0;
 331
 332         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 333                 err = vlan_vid_add(dev, vid_info->vid);
 334                 if (err)
 335                         goto unwind;
 336         }
 337         return 0;
 338
 339 unwind:
 340         list_for_each_entry_continue_reverse(vid_info,
 341                                              &vlan_info->vid_list,
 342                                              list) {
 343                 vlan_vid_del(dev, vid_info->vid);
 344         }
 345
 346         return err;
 347 }
 348 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 349
 350 void vlan_vids_del_by_dev(struct net_device *dev,
 351                           const struct net_device *by_dev)
 352 {
 353         struct vlan_vid_info *vid_info;
 354         struct vlan_info *vlan_info;
 355
 356         ASSERT_RTNL();
 357
 358         vlan_info = rtnl_dereference(by_dev->vlan_info);
 359         if (!vlan_info)
 360                 return;
 361
 362         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 363                 vlan_vid_del(dev, vid_info->vid);
 364 }
 365 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 366
 367 bool vlan_uses_dev(const struct net_device *dev)
 368 {
 369         return rtnl_dereference(dev->vlan_info) ? true : false;
 370 }
 371 EXPORT_SYMBOL(vlan_uses_dev);