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 = vlan_tx_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 (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         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 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 110 {
 111         if (skb_cow(skb, skb_headroom(skb)) < 0)
 112                 return NULL;
 113         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 114         skb->mac_header += VLAN_HLEN;
 115         return skb;
 116 }
 117
 118 struct sk_buff *vlan_untag(struct sk_buff *skb)
 119 {
 120         struct vlan_hdr *vhdr;
 121         u16 vlan_tci;
 122
 123         if (unlikely(vlan_tx_tag_present(skb))) {
 124                 /* vlan_tci is already set-up so leave this for another time */
 125                 return skb;
 126         }
 127
 128         skb = skb_share_check(skb, GFP_ATOMIC);
 129         if (unlikely(!skb))
 130                 goto err_free;
 131
 132         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 133                 goto err_free;
 134
 135         vhdr = (struct vlan_hdr *) skb->data;
 136         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 137         __vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
 138
 139         skb_pull_rcsum(skb, VLAN_HLEN);
 140         vlan_set_encap_proto(skb, vhdr);
 141
 142         skb = vlan_reorder_header(skb);
 143         if (unlikely(!skb))
 144                 goto err_free;
 145
 146         skb_reset_network_header(skb);
 147         skb_reset_transport_header(skb);
 148         skb_reset_mac_len(skb);
 149
 150         return skb;
 151
 152 err_free:
 153         kfree_skb(skb);
 154         return NULL;
 155 }
 156 EXPORT_SYMBOL(vlan_untag);
 157
 158
 159 /*
 160  * vlan info and vid list
 161  */
 162
 163 static void vlan_group_free(struct vlan_group *grp)
 164 {
 165         int i, j;
 166
 167         for (i = 0; i < VLAN_PROTO_NUM; i++)
 168                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 169                         kfree(grp->vlan_devices_arrays[i][j]);
 170 }
 171
 172 static void vlan_info_free(struct vlan_info *vlan_info)
 173 {
 174         vlan_group_free(&vlan_info->grp);
 175         kfree(vlan_info);
 176 }
 177
 178 static void vlan_info_rcu_free(struct rcu_head *rcu)
 179 {
 180         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 181 }
 182
 183 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 184 {
 185         struct vlan_info *vlan_info;
 186
 187         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 188         if (!vlan_info)
 189                 return NULL;
 190
 191         vlan_info->real_dev = dev;
 192         INIT_LIST_HEAD(&vlan_info->vid_list);
 193         return vlan_info;
 194 }
 195
 196 struct vlan_vid_info {
 197         struct list_head list;
 198         __be16 proto;
 199         u16 vid;
 200         int refcount;
 201 };
 202
 203 static bool vlan_hw_filter_capable(const struct net_device *dev,
 204                                      const struct vlan_vid_info *vid_info)
 205 {
 206         if (vid_info->proto == htons(ETH_P_8021Q) &&
 207             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 208                 return true;
 209         if (vid_info->proto == htons(ETH_P_8021AD) &&
 210             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 211                 return true;
 212         return false;
 213 }
 214
 215 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 216                                                __be16 proto, u16 vid)
 217 {
 218         struct vlan_vid_info *vid_info;
 219
 220         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 221                 if (vid_info->proto == proto && vid_info->vid == vid)
 222                         return vid_info;
 223         }
 224         return NULL;
 225 }
 226
 227 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 228 {
 229         struct vlan_vid_info *vid_info;
 230
 231         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 232         if (!vid_info)
 233                 return NULL;
 234         vid_info->proto = proto;
 235         vid_info->vid = vid;
 236
 237         return vid_info;
 238 }
 239
 240 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 241                           struct vlan_vid_info **pvid_info)
 242 {
 243         struct net_device *dev = vlan_info->real_dev;
 244         const struct net_device_ops *ops = dev->netdev_ops;
 245         struct vlan_vid_info *vid_info;
 246         int err;
 247
 248         vid_info = vlan_vid_info_alloc(proto, vid);
 249         if (!vid_info)
 250                 return -ENOMEM;
 251
 252         if (vlan_hw_filter_capable(dev, vid_info)) {
 253                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 254                 if (err) {
 255                         kfree(vid_info);
 256                         return err;
 257                 }
 258         }
 259         list_add(&vid_info->list, &vlan_info->vid_list);
 260         vlan_info->nr_vids++;
 261         *pvid_info = vid_info;
 262         return 0;
 263 }
 264
 265 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 266 {
 267         struct vlan_info *vlan_info;
 268         struct vlan_vid_info *vid_info;
 269         bool vlan_info_created = false;
 270         int err;
 271
 272         ASSERT_RTNL();
 273
 274         vlan_info = rtnl_dereference(dev->vlan_info);
 275         if (!vlan_info) {
 276                 vlan_info = vlan_info_alloc(dev);
 277                 if (!vlan_info)
 278                         return -ENOMEM;
 279                 vlan_info_created = true;
 280         }
 281         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 282         if (!vid_info) {
 283                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 284                 if (err)
 285                         goto out_free_vlan_info;
 286         }
 287         vid_info->refcount++;
 288
 289         if (vlan_info_created)
 290                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 291
 292         return 0;
 293
 294 out_free_vlan_info:
 295         if (vlan_info_created)
 296                 kfree(vlan_info);
 297         return err;
 298 }
 299 EXPORT_SYMBOL(vlan_vid_add);
 300
 301 static void __vlan_vid_del(struct vlan_info *vlan_info,
 302                            struct vlan_vid_info *vid_info)
 303 {
 304         struct net_device *dev = vlan_info->real_dev;
 305         const struct net_device_ops *ops = dev->netdev_ops;
 306         __be16 proto = vid_info->proto;
 307         u16 vid = vid_info->vid;
 308         int err;
 309
 310         if (vlan_hw_filter_capable(dev, vid_info)) {
 311                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 312                 if (err) {
 313                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 314                                 proto, vid, dev->name);
 315                 }
 316         }
 317         list_del(&vid_info->list);
 318         kfree(vid_info);
 319         vlan_info->nr_vids--;
 320 }
 321
 322 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 323 {
 324         struct vlan_info *vlan_info;
 325         struct vlan_vid_info *vid_info;
 326
 327         ASSERT_RTNL();
 328
 329         vlan_info = rtnl_dereference(dev->vlan_info);
 330         if (!vlan_info)
 331                 return;
 332
 333         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 334         if (!vid_info)
 335                 return;
 336         vid_info->refcount--;
 337         if (vid_info->refcount == 0) {
 338                 __vlan_vid_del(vlan_info, vid_info);
 339                 if (vlan_info->nr_vids == 0) {
 340                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 341                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 342                 }
 343         }
 344 }
 345 EXPORT_SYMBOL(vlan_vid_del);
 346
 347 int vlan_vids_add_by_dev(struct net_device *dev,
 348                          const struct net_device *by_dev)
 349 {
 350         struct vlan_vid_info *vid_info;
 351         struct vlan_info *vlan_info;
 352         int err;
 353
 354         ASSERT_RTNL();
 355
 356         vlan_info = rtnl_dereference(by_dev->vlan_info);
 357         if (!vlan_info)
 358                 return 0;
 359
 360         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 361                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 362                 if (err)
 363                         goto unwind;
 364         }
 365         return 0;
 366
 367 unwind:
 368         list_for_each_entry_continue_reverse(vid_info,
 369                                              &vlan_info->vid_list,
 370                                              list) {
 371                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 372         }
 373
 374         return err;
 375 }
 376 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 377
 378 void vlan_vids_del_by_dev(struct net_device *dev,
 379                           const struct net_device *by_dev)
 380 {
 381         struct vlan_vid_info *vid_info;
 382         struct vlan_info *vlan_info;
 383
 384         ASSERT_RTNL();
 385
 386         vlan_info = rtnl_dereference(by_dev->vlan_info);
 387         if (!vlan_info)
 388                 return;
 389
 390         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 391                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 392 }
 393 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 394
 395 bool vlan_uses_dev(const struct net_device *dev)
 396 {
 397         struct vlan_info *vlan_info;
 398
 399         ASSERT_RTNL();
 400
 401         vlan_info = rtnl_dereference(dev->vlan_info);
 402         if (!vlan_info)
 403                 return false;
 404         return vlan_info->grp.nr_vlan_devs ? true : false;
 405 }
 406 EXPORT_SYMBOL(vlan_uses_dev);