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_tci & VLAN_VID_MASK;
  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 (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(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(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(upper_dev,
  85                                                     vlan_proto, vlan_id);
  86         }
  87
  88         return NULL;
  89 }
  90 EXPORT_SYMBOL(__vlan_find_dev_deep);
  91
  92 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  93 {
  94         return vlan_dev_priv(dev)->real_dev;
  95 }
  96 EXPORT_SYMBOL(vlan_dev_real_dev);
  97
  98 u16 vlan_dev_vlan_id(const struct net_device *dev)
  99 {
 100         return vlan_dev_priv(dev)->vlan_id;
 101 }
 102 EXPORT_SYMBOL(vlan_dev_vlan_id);
 103
 104 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 105 {
 106         if (skb_cow(skb, skb_headroom(skb)) < 0)
 107                 return NULL;
 108         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 109         skb->mac_header += VLAN_HLEN;
 110         return skb;
 111 }
 112
 113 struct sk_buff *vlan_untag(struct sk_buff *skb)
 114 {
 115         struct vlan_hdr *vhdr;
 116         u16 vlan_tci;
 117
 118         if (unlikely(vlan_tx_tag_present(skb))) {
 119                 /* vlan_tci is already set-up so leave this for another time */
 120                 return skb;
 121         }
 122
 123         skb = skb_share_check(skb, GFP_ATOMIC);
 124         if (unlikely(!skb))
 125                 goto err_free;
 126
 127         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 128                 goto err_free;
 129
 130         vhdr = (struct vlan_hdr *) skb->data;
 131         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 132         __vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
 133
 134         skb_pull_rcsum(skb, VLAN_HLEN);
 135         vlan_set_encap_proto(skb, vhdr);
 136
 137         skb = vlan_reorder_header(skb);
 138         if (unlikely(!skb))
 139                 goto err_free;
 140
 141         skb_reset_network_header(skb);
 142         skb_reset_transport_header(skb);
 143         skb_reset_mac_len(skb);
 144
 145         return skb;
 146
 147 err_free:
 148         kfree_skb(skb);
 149         return NULL;
 150 }
 151 EXPORT_SYMBOL(vlan_untag);
 152
 153
 154 /*
 155  * vlan info and vid list
 156  */
 157
 158 static void vlan_group_free(struct vlan_group *grp)
 159 {
 160         int i, j;
 161
 162         for (i = 0; i < VLAN_PROTO_NUM; i++)
 163                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 164                         kfree(grp->vlan_devices_arrays[i][j]);
 165 }
 166
 167 static void vlan_info_free(struct vlan_info *vlan_info)
 168 {
 169         vlan_group_free(&vlan_info->grp);
 170         kfree(vlan_info);
 171 }
 172
 173 static void vlan_info_rcu_free(struct rcu_head *rcu)
 174 {
 175         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 176 }
 177
 178 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 179 {
 180         struct vlan_info *vlan_info;
 181
 182         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 183         if (!vlan_info)
 184                 return NULL;
 185
 186         vlan_info->real_dev = dev;
 187         INIT_LIST_HEAD(&vlan_info->vid_list);
 188         return vlan_info;
 189 }
 190
 191 struct vlan_vid_info {
 192         struct list_head list;
 193         __be16 proto;
 194         u16 vid;
 195         int refcount;
 196 };
 197
 198 static bool vlan_hw_filter_capable(const struct net_device *dev,
 199                                      const struct vlan_vid_info *vid_info)
 200 {
 201         if (vid_info->proto == htons(ETH_P_8021Q) &&
 202             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 203                 return true;
 204         if (vid_info->proto == htons(ETH_P_8021AD) &&
 205             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 206                 return true;
 207         return false;
 208 }
 209
 210 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 211                                                __be16 proto, u16 vid)
 212 {
 213         struct vlan_vid_info *vid_info;
 214
 215         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 216                 if (vid_info->proto == proto && vid_info->vid == vid)
 217                         return vid_info;
 218         }
 219         return NULL;
 220 }
 221
 222 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 223 {
 224         struct vlan_vid_info *vid_info;
 225
 226         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 227         if (!vid_info)
 228                 return NULL;
 229         vid_info->proto = proto;
 230         vid_info->vid = vid;
 231
 232         return vid_info;
 233 }
 234
 235 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 236                           struct vlan_vid_info **pvid_info)
 237 {
 238         struct net_device *dev = vlan_info->real_dev;
 239         const struct net_device_ops *ops = dev->netdev_ops;
 240         struct vlan_vid_info *vid_info;
 241         int err;
 242
 243         vid_info = vlan_vid_info_alloc(proto, vid);
 244         if (!vid_info)
 245                 return -ENOMEM;
 246
 247         if (vlan_hw_filter_capable(dev, vid_info)) {
 248                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 249                 if (err) {
 250                         kfree(vid_info);
 251                         return err;
 252                 }
 253         }
 254         list_add(&vid_info->list, &vlan_info->vid_list);
 255         vlan_info->nr_vids++;
 256         *pvid_info = vid_info;
 257         return 0;
 258 }
 259
 260 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 261 {
 262         struct vlan_info *vlan_info;
 263         struct vlan_vid_info *vid_info;
 264         bool vlan_info_created = false;
 265         int err;
 266
 267         ASSERT_RTNL();
 268
 269         vlan_info = rtnl_dereference(dev->vlan_info);
 270         if (!vlan_info) {
 271                 vlan_info = vlan_info_alloc(dev);
 272                 if (!vlan_info)
 273                         return -ENOMEM;
 274                 vlan_info_created = true;
 275         }
 276         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 277         if (!vid_info) {
 278                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 279                 if (err)
 280                         goto out_free_vlan_info;
 281         }
 282         vid_info->refcount++;
 283
 284         if (vlan_info_created)
 285                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 286
 287         return 0;
 288
 289 out_free_vlan_info:
 290         if (vlan_info_created)
 291                 kfree(vlan_info);
 292         return err;
 293 }
 294 EXPORT_SYMBOL(vlan_vid_add);
 295
 296 static void __vlan_vid_del(struct vlan_info *vlan_info,
 297                            struct vlan_vid_info *vid_info)
 298 {
 299         struct net_device *dev = vlan_info->real_dev;
 300         const struct net_device_ops *ops = dev->netdev_ops;
 301         __be16 proto = vid_info->proto;
 302         u16 vid = vid_info->vid;
 303         int err;
 304
 305         if (vlan_hw_filter_capable(dev, vid_info)) {
 306                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 307                 if (err) {
 308                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 309                                 proto, vid, dev->name);
 310                 }
 311         }
 312         list_del(&vid_info->list);
 313         kfree(vid_info);
 314         vlan_info->nr_vids--;
 315 }
 316
 317 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 318 {
 319         struct vlan_info *vlan_info;
 320         struct vlan_vid_info *vid_info;
 321
 322         ASSERT_RTNL();
 323
 324         vlan_info = rtnl_dereference(dev->vlan_info);
 325         if (!vlan_info)
 326                 return;
 327
 328         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 329         if (!vid_info)
 330                 return;
 331         vid_info->refcount--;
 332         if (vid_info->refcount == 0) {
 333                 __vlan_vid_del(vlan_info, vid_info);
 334                 if (vlan_info->nr_vids == 0) {
 335                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 336                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 337                 }
 338         }
 339 }
 340 EXPORT_SYMBOL(vlan_vid_del);
 341
 342 int vlan_vids_add_by_dev(struct net_device *dev,
 343                          const struct net_device *by_dev)
 344 {
 345         struct vlan_vid_info *vid_info;
 346         struct vlan_info *vlan_info;
 347         int err;
 348
 349         ASSERT_RTNL();
 350
 351         vlan_info = rtnl_dereference(by_dev->vlan_info);
 352         if (!vlan_info)
 353                 return 0;
 354
 355         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 356                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 357                 if (err)
 358                         goto unwind;
 359         }
 360         return 0;
 361
 362 unwind:
 363         list_for_each_entry_continue_reverse(vid_info,
 364                                              &vlan_info->vid_list,
 365                                              list) {
 366                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 367         }
 368
 369         return err;
 370 }
 371 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 372
 373 void vlan_vids_del_by_dev(struct net_device *dev,
 374                           const struct net_device *by_dev)
 375 {
 376         struct vlan_vid_info *vid_info;
 377         struct vlan_info *vlan_info;
 378
 379         ASSERT_RTNL();
 380
 381         vlan_info = rtnl_dereference(by_dev->vlan_info);
 382         if (!vlan_info)
 383                 return;
 384
 385         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 386                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 387 }
 388 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 389
 390 bool vlan_uses_dev(const struct net_device *dev)
 391 {
 392         struct vlan_info *vlan_info;
 393
 394         ASSERT_RTNL();
 395
 396         vlan_info = rtnl_dereference(dev->vlan_info);
 397         if (!vlan_info)
 398                 return false;
 399         return vlan_info->grp.nr_vlan_devs ? true : false;
 400 }
 401 EXPORT_SYMBOL(vlan_uses_dev);