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, htons(ETH_P_8021Q), 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                                         __be16 vlan_proto, 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,
  71                                              vlan_proto, vlan_id);
  72         } else {
  73                 /*
  74                  * Lower devices of master uppers (bonding, team) do not have
  75                  * grp assigned to themselves. Grp is assigned to upper device
  76                  * instead.
  77                  */
  78                 struct net_device *upper_dev;
  79
  80                 upper_dev = netdev_master_upper_dev_get_rcu(dev);
  81                 if (upper_dev)
  82                         return __vlan_find_dev_deep(upper_dev,
  83                                                     vlan_proto, 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         return skb;
 109 }
 110
 111 struct sk_buff *vlan_untag(struct sk_buff *skb)
 112 {
 113         struct vlan_hdr *vhdr;
 114         u16 vlan_tci;
 115
 116         if (unlikely(vlan_tx_tag_present(skb))) {
 117                 /* vlan_tci is already set-up so leave this for another time */
 118                 return skb;
 119         }
 120
 121         skb = skb_share_check(skb, GFP_ATOMIC);
 122         if (unlikely(!skb))
 123                 goto err_free;
 124
 125         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 126                 goto err_free;
 127
 128         vhdr = (struct vlan_hdr *) skb->data;
 129         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 130         __vlan_hwaccel_put_tag(skb, vlan_tci);
 131
 132         skb_pull_rcsum(skb, VLAN_HLEN);
 133         vlan_set_encap_proto(skb, vhdr);
 134
 135         skb = vlan_reorder_header(skb);
 136         if (unlikely(!skb))
 137                 goto err_free;
 138
 139         skb_reset_network_header(skb);
 140         skb_reset_transport_header(skb);
 141         skb_reset_mac_len(skb);
 142
 143         return skb;
 144
 145 err_free:
 146         kfree_skb(skb);
 147         return NULL;
 148 }
 149 EXPORT_SYMBOL(vlan_untag);
 150
 151
 152 /*
 153  * vlan info and vid list
 154  */
 155
 156 static void vlan_group_free(struct vlan_group *grp)
 157 {
 158         int i;
 159
 160         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
 161                 kfree(grp->vlan_devices_arrays[i]);
 162 }
 163
 164 static void vlan_info_free(struct vlan_info *vlan_info)
 165 {
 166         vlan_group_free(&vlan_info->grp);
 167         kfree(vlan_info);
 168 }
 169
 170 static void vlan_info_rcu_free(struct rcu_head *rcu)
 171 {
 172         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 173 }
 174
 175 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 176 {
 177         struct vlan_info *vlan_info;
 178
 179         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 180         if (!vlan_info)
 181                 return NULL;
 182
 183         vlan_info->real_dev = dev;
 184         INIT_LIST_HEAD(&vlan_info->vid_list);
 185         return vlan_info;
 186 }
 187
 188 struct vlan_vid_info {
 189         struct list_head list;
 190         __be16 proto;
 191         u16 vid;
 192         int refcount;
 193 };
 194
 195 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 196                                                __be16 proto, u16 vid)
 197 {
 198         struct vlan_vid_info *vid_info;
 199
 200         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 201                 if (vid_info->proto == proto && vid_info->vid == vid)
 202                         return vid_info;
 203         }
 204         return NULL;
 205 }
 206
 207 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 208 {
 209         struct vlan_vid_info *vid_info;
 210
 211         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 212         if (!vid_info)
 213                 return NULL;
 214         vid_info->proto = proto;
 215         vid_info->vid = vid;
 216
 217         return vid_info;
 218 }
 219
 220 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 221                           struct vlan_vid_info **pvid_info)
 222 {
 223         struct net_device *dev = vlan_info->real_dev;
 224         const struct net_device_ops *ops = dev->netdev_ops;
 225         struct vlan_vid_info *vid_info;
 226         int err;
 227
 228         vid_info = vlan_vid_info_alloc(proto, vid);
 229         if (!vid_info)
 230                 return -ENOMEM;
 231
 232         if (proto == htons(ETH_P_8021Q) &&
 233             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER) {
 234                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 235                 if (err) {
 236                         kfree(vid_info);
 237                         return err;
 238                 }
 239         }
 240         list_add(&vid_info->list, &vlan_info->vid_list);
 241         vlan_info->nr_vids++;
 242         *pvid_info = vid_info;
 243         return 0;
 244 }
 245
 246 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 247 {
 248         struct vlan_info *vlan_info;
 249         struct vlan_vid_info *vid_info;
 250         bool vlan_info_created = false;
 251         int err;
 252
 253         ASSERT_RTNL();
 254
 255         vlan_info = rtnl_dereference(dev->vlan_info);
 256         if (!vlan_info) {
 257                 vlan_info = vlan_info_alloc(dev);
 258                 if (!vlan_info)
 259                         return -ENOMEM;
 260                 vlan_info_created = true;
 261         }
 262         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 263         if (!vid_info) {
 264                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 265                 if (err)
 266                         goto out_free_vlan_info;
 267         }
 268         vid_info->refcount++;
 269
 270         if (vlan_info_created)
 271                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 272
 273         return 0;
 274
 275 out_free_vlan_info:
 276         if (vlan_info_created)
 277                 kfree(vlan_info);
 278         return err;
 279 }
 280 EXPORT_SYMBOL(vlan_vid_add);
 281
 282 static void __vlan_vid_del(struct vlan_info *vlan_info,
 283                            struct vlan_vid_info *vid_info)
 284 {
 285         struct net_device *dev = vlan_info->real_dev;
 286         const struct net_device_ops *ops = dev->netdev_ops;
 287         __be16 proto = vid_info->proto;
 288         u16 vid = vid_info->vid;
 289         int err;
 290
 291         if (proto == htons(ETH_P_8021Q) &&
 292             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER) {
 293                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 294                 if (err) {
 295                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 296                                 proto, vid, dev->name);
 297                 }
 298         }
 299         list_del(&vid_info->list);
 300         kfree(vid_info);
 301         vlan_info->nr_vids--;
 302 }
 303
 304 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 305 {
 306         struct vlan_info *vlan_info;
 307         struct vlan_vid_info *vid_info;
 308
 309         ASSERT_RTNL();
 310
 311         vlan_info = rtnl_dereference(dev->vlan_info);
 312         if (!vlan_info)
 313                 return;
 314
 315         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 316         if (!vid_info)
 317                 return;
 318         vid_info->refcount--;
 319         if (vid_info->refcount == 0) {
 320                 __vlan_vid_del(vlan_info, vid_info);
 321                 if (vlan_info->nr_vids == 0) {
 322                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 323                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 324                 }
 325         }
 326 }
 327 EXPORT_SYMBOL(vlan_vid_del);
 328
 329 int vlan_vids_add_by_dev(struct net_device *dev,
 330                          const struct net_device *by_dev)
 331 {
 332         struct vlan_vid_info *vid_info;
 333         struct vlan_info *vlan_info;
 334         int err;
 335
 336         ASSERT_RTNL();
 337
 338         vlan_info = rtnl_dereference(by_dev->vlan_info);
 339         if (!vlan_info)
 340                 return 0;
 341
 342         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 343                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 344                 if (err)
 345                         goto unwind;
 346         }
 347         return 0;
 348
 349 unwind:
 350         list_for_each_entry_continue_reverse(vid_info,
 351                                              &vlan_info->vid_list,
 352                                              list) {
 353                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 354         }
 355
 356         return err;
 357 }
 358 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 359
 360 void vlan_vids_del_by_dev(struct net_device *dev,
 361                           const struct net_device *by_dev)
 362 {
 363         struct vlan_vid_info *vid_info;
 364         struct vlan_info *vlan_info;
 365
 366         ASSERT_RTNL();
 367
 368         vlan_info = rtnl_dereference(by_dev->vlan_info);
 369         if (!vlan_info)
 370                 return;
 371
 372         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 373                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 374 }
 375 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 376
 377 bool vlan_uses_dev(const struct net_device *dev)
 378 {
 379         struct vlan_info *vlan_info;
 380
 381         ASSERT_RTNL();
 382
 383         vlan_info = rtnl_dereference(dev->vlan_info);
 384         if (!vlan_info)
 385                 return false;
 386         return vlan_info->grp.nr_vlan_devs ? true : false;
 387 }
 388 EXPORT_SYMBOL(vlan_uses_dev);