kernel/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 = skb_vlan_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 /*
 116  * vlan info and vid list
 117  */
 118
 119 static void vlan_group_free(struct vlan_group *grp)
 120 {
 121         int i, j;
 122
 123         for (i = 0; i < VLAN_PROTO_NUM; i++)
 124                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 125                         kfree(grp->vlan_devices_arrays[i][j]);
 126 }
 127
 128 static void vlan_info_free(struct vlan_info *vlan_info)
 129 {
 130         vlan_group_free(&vlan_info->grp);
 131         kfree(vlan_info);
 132 }
 133
 134 static void vlan_info_rcu_free(struct rcu_head *rcu)
 135 {
 136         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 137 }
 138
 139 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 140 {
 141         struct vlan_info *vlan_info;
 142
 143         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 144         if (!vlan_info)
 145                 return NULL;
 146
 147         vlan_info->real_dev = dev;
 148         INIT_LIST_HEAD(&vlan_info->vid_list);
 149         return vlan_info;
 150 }
 151
 152 struct vlan_vid_info {
 153         struct list_head list;
 154         __be16 proto;
 155         u16 vid;
 156         int refcount;
 157 };
 158
 159 static bool vlan_hw_filter_capable(const struct net_device *dev,
 160                                      const struct vlan_vid_info *vid_info)
 161 {
 162         if (vid_info->proto == htons(ETH_P_8021Q) &&
 163             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 164                 return true;
 165         if (vid_info->proto == htons(ETH_P_8021AD) &&
 166             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 167                 return true;
 168         return false;
 169 }
 170
 171 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 172                                                __be16 proto, u16 vid)
 173 {
 174         struct vlan_vid_info *vid_info;
 175
 176         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 177                 if (vid_info->proto == proto && vid_info->vid == vid)
 178                         return vid_info;
 179         }
 180         return NULL;
 181 }
 182
 183 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 184 {
 185         struct vlan_vid_info *vid_info;
 186
 187         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 188         if (!vid_info)
 189                 return NULL;
 190         vid_info->proto = proto;
 191         vid_info->vid = vid;
 192
 193         return vid_info;
 194 }
 195
 196 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 197                           struct vlan_vid_info **pvid_info)
 198 {
 199         struct net_device *dev = vlan_info->real_dev;
 200         const struct net_device_ops *ops = dev->netdev_ops;
 201         struct vlan_vid_info *vid_info;
 202         int err;
 203
 204         vid_info = vlan_vid_info_alloc(proto, vid);
 205         if (!vid_info)
 206                 return -ENOMEM;
 207
 208         if (vlan_hw_filter_capable(dev, vid_info)) {
 209                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 210                 if (err) {
 211                         kfree(vid_info);
 212                         return err;
 213                 }
 214         }
 215         list_add(&vid_info->list, &vlan_info->vid_list);
 216         vlan_info->nr_vids++;
 217         *pvid_info = vid_info;
 218         return 0;
 219 }
 220
 221 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 222 {
 223         struct vlan_info *vlan_info;
 224         struct vlan_vid_info *vid_info;
 225         bool vlan_info_created = false;
 226         int err;
 227
 228         ASSERT_RTNL();
 229
 230         vlan_info = rtnl_dereference(dev->vlan_info);
 231         if (!vlan_info) {
 232                 vlan_info = vlan_info_alloc(dev);
 233                 if (!vlan_info)
 234                         return -ENOMEM;
 235                 vlan_info_created = true;
 236         }
 237         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 238         if (!vid_info) {
 239                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 240                 if (err)
 241                         goto out_free_vlan_info;
 242         }
 243         vid_info->refcount++;
 244
 245         if (vlan_info_created)
 246                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 247
 248         return 0;
 249
 250 out_free_vlan_info:
 251         if (vlan_info_created)
 252                 kfree(vlan_info);
 253         return err;
 254 }
 255 EXPORT_SYMBOL(vlan_vid_add);
 256
 257 static void __vlan_vid_del(struct vlan_info *vlan_info,
 258                            struct vlan_vid_info *vid_info)
 259 {
 260         struct net_device *dev = vlan_info->real_dev;
 261         const struct net_device_ops *ops = dev->netdev_ops;
 262         __be16 proto = vid_info->proto;
 263         u16 vid = vid_info->vid;
 264         int err;
 265
 266         if (vlan_hw_filter_capable(dev, vid_info)) {
 267                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 268                 if (err) {
 269                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 270                                 proto, vid, dev->name);
 271                 }
 272         }
 273         list_del(&vid_info->list);
 274         kfree(vid_info);
 275         vlan_info->nr_vids--;
 276 }
 277
 278 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 279 {
 280         struct vlan_info *vlan_info;
 281         struct vlan_vid_info *vid_info;
 282
 283         ASSERT_RTNL();
 284
 285         vlan_info = rtnl_dereference(dev->vlan_info);
 286         if (!vlan_info)
 287                 return;
 288
 289         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 290         if (!vid_info)
 291                 return;
 292         vid_info->refcount--;
 293         if (vid_info->refcount == 0) {
 294                 __vlan_vid_del(vlan_info, vid_info);
 295                 if (vlan_info->nr_vids == 0) {
 296                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 297                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 298                 }
 299         }
 300 }
 301 EXPORT_SYMBOL(vlan_vid_del);
 302
 303 int vlan_vids_add_by_dev(struct net_device *dev,
 304                          const struct net_device *by_dev)
 305 {
 306         struct vlan_vid_info *vid_info;
 307         struct vlan_info *vlan_info;
 308         int err;
 309
 310         ASSERT_RTNL();
 311
 312         vlan_info = rtnl_dereference(by_dev->vlan_info);
 313         if (!vlan_info)
 314                 return 0;
 315
 316         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 317                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 318                 if (err)
 319                         goto unwind;
 320         }
 321         return 0;
 322
 323 unwind:
 324         list_for_each_entry_continue_reverse(vid_info,
 325                                              &vlan_info->vid_list,
 326                                              list) {
 327                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 328         }
 329
 330         return err;
 331 }
 332 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 333
 334 void vlan_vids_del_by_dev(struct net_device *dev,
 335                           const struct net_device *by_dev)
 336 {
 337         struct vlan_vid_info *vid_info;
 338         struct vlan_info *vlan_info;
 339
 340         ASSERT_RTNL();
 341
 342         vlan_info = rtnl_dereference(by_dev->vlan_info);
 343         if (!vlan_info)
 344                 return;
 345
 346         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 347                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 348 }
 349 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 350
 351 bool vlan_uses_dev(const struct net_device *dev)
 352 {
 353         struct vlan_info *vlan_info;
 354
 355         ASSERT_RTNL();
 356
 357         vlan_info = rtnl_dereference(dev->vlan_info);
 358         if (!vlan_info)
 359                 return false;
 360         return vlan_info->grp.nr_vlan_devs ? true : false;
 361 }
 362 EXPORT_SYMBOL(vlan_uses_dev);