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 (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 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 116 {
 117         if (skb_cow(skb, skb_headroom(skb)) < 0) {
 118                 kfree_skb(skb);
 119                 return NULL;
 120         }
 121
 122         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 123         skb->mac_header += VLAN_HLEN;
 124         return skb;
 125 }
 126
 127 struct sk_buff *vlan_untag(struct sk_buff *skb)
 128 {
 129         struct vlan_hdr *vhdr;
 130         u16 vlan_tci;
 131
 132         if (unlikely(vlan_tx_tag_present(skb))) {
 133                 /* vlan_tci is already set-up so leave this for another time */
 134                 return skb;
 135         }
 136
 137         skb = skb_share_check(skb, GFP_ATOMIC);
 138         if (unlikely(!skb))
 139                 goto err_free;
 140
 141         if (unlikely(!pskb_may_pull(skb, VLAN_HLEN)))
 142                 goto err_free;
 143
 144         vhdr = (struct vlan_hdr *) skb->data;
 145         vlan_tci = ntohs(vhdr->h_vlan_TCI);
 146         __vlan_hwaccel_put_tag(skb, skb->protocol, vlan_tci);
 147
 148         skb_pull_rcsum(skb, VLAN_HLEN);
 149         vlan_set_encap_proto(skb, vhdr);
 150
 151         skb = vlan_reorder_header(skb);
 152         if (unlikely(!skb))
 153                 goto err_free;
 154
 155         skb_reset_network_header(skb);
 156         skb_reset_transport_header(skb);
 157         skb_reset_mac_len(skb);
 158
 159         return skb;
 160
 161 err_free:
 162         kfree_skb(skb);
 163         return NULL;
 164 }
 165 EXPORT_SYMBOL(vlan_untag);
 166
 167
 168 /*
 169  * vlan info and vid list
 170  */
 171
 172 static void vlan_group_free(struct vlan_group *grp)
 173 {
 174         int i, j;
 175
 176         for (i = 0; i < VLAN_PROTO_NUM; i++)
 177                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 178                         kfree(grp->vlan_devices_arrays[i][j]);
 179 }
 180
 181 static void vlan_info_free(struct vlan_info *vlan_info)
 182 {
 183         vlan_group_free(&vlan_info->grp);
 184         kfree(vlan_info);
 185 }
 186
 187 static void vlan_info_rcu_free(struct rcu_head *rcu)
 188 {
 189         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 190 }
 191
 192 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 193 {
 194         struct vlan_info *vlan_info;
 195
 196         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 197         if (!vlan_info)
 198                 return NULL;
 199
 200         vlan_info->real_dev = dev;
 201         INIT_LIST_HEAD(&vlan_info->vid_list);
 202         return vlan_info;
 203 }
 204
 205 struct vlan_vid_info {
 206         struct list_head list;
 207         __be16 proto;
 208         u16 vid;
 209         int refcount;
 210 };
 211
 212 static bool vlan_hw_filter_capable(const struct net_device *dev,
 213                                      const struct vlan_vid_info *vid_info)
 214 {
 215         if (vid_info->proto == htons(ETH_P_8021Q) &&
 216             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 217                 return true;
 218         if (vid_info->proto == htons(ETH_P_8021AD) &&
 219             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 220                 return true;
 221         return false;
 222 }
 223
 224 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 225                                                __be16 proto, u16 vid)
 226 {
 227         struct vlan_vid_info *vid_info;
 228
 229         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 230                 if (vid_info->proto == proto && vid_info->vid == vid)
 231                         return vid_info;
 232         }
 233         return NULL;
 234 }
 235
 236 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 237 {
 238         struct vlan_vid_info *vid_info;
 239
 240         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 241         if (!vid_info)
 242                 return NULL;
 243         vid_info->proto = proto;
 244         vid_info->vid = vid;
 245
 246         return vid_info;
 247 }
 248
 249 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 250                           struct vlan_vid_info **pvid_info)
 251 {
 252         struct net_device *dev = vlan_info->real_dev;
 253         const struct net_device_ops *ops = dev->netdev_ops;
 254         struct vlan_vid_info *vid_info;
 255         int err;
 256
 257         vid_info = vlan_vid_info_alloc(proto, vid);
 258         if (!vid_info)
 259                 return -ENOMEM;
 260
 261         if (vlan_hw_filter_capable(dev, vid_info)) {
 262                 err =  ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 263                 if (err) {
 264                         kfree(vid_info);
 265                         return err;
 266                 }
 267         }
 268         list_add(&vid_info->list, &vlan_info->vid_list);
 269         vlan_info->nr_vids++;
 270         *pvid_info = vid_info;
 271         return 0;
 272 }
 273
 274 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 275 {
 276         struct vlan_info *vlan_info;
 277         struct vlan_vid_info *vid_info;
 278         bool vlan_info_created = false;
 279         int err;
 280
 281         ASSERT_RTNL();
 282
 283         vlan_info = rtnl_dereference(dev->vlan_info);
 284         if (!vlan_info) {
 285                 vlan_info = vlan_info_alloc(dev);
 286                 if (!vlan_info)
 287                         return -ENOMEM;
 288                 vlan_info_created = true;
 289         }
 290         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 291         if (!vid_info) {
 292                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 293                 if (err)
 294                         goto out_free_vlan_info;
 295         }
 296         vid_info->refcount++;
 297
 298         if (vlan_info_created)
 299                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 300
 301         return 0;
 302
 303 out_free_vlan_info:
 304         if (vlan_info_created)
 305                 kfree(vlan_info);
 306         return err;
 307 }
 308 EXPORT_SYMBOL(vlan_vid_add);
 309
 310 static void __vlan_vid_del(struct vlan_info *vlan_info,
 311                            struct vlan_vid_info *vid_info)
 312 {
 313         struct net_device *dev = vlan_info->real_dev;
 314         const struct net_device_ops *ops = dev->netdev_ops;
 315         __be16 proto = vid_info->proto;
 316         u16 vid = vid_info->vid;
 317         int err;
 318
 319         if (vlan_hw_filter_capable(dev, vid_info)) {
 320                 err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 321                 if (err) {
 322                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 323                                 proto, vid, dev->name);
 324                 }
 325         }
 326         list_del(&vid_info->list);
 327         kfree(vid_info);
 328         vlan_info->nr_vids--;
 329 }
 330
 331 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 332 {
 333         struct vlan_info *vlan_info;
 334         struct vlan_vid_info *vid_info;
 335
 336         ASSERT_RTNL();
 337
 338         vlan_info = rtnl_dereference(dev->vlan_info);
 339         if (!vlan_info)
 340                 return;
 341
 342         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 343         if (!vid_info)
 344                 return;
 345         vid_info->refcount--;
 346         if (vid_info->refcount == 0) {
 347                 __vlan_vid_del(vlan_info, vid_info);
 348                 if (vlan_info->nr_vids == 0) {
 349                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 350                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 351                 }
 352         }
 353 }
 354 EXPORT_SYMBOL(vlan_vid_del);
 355
 356 int vlan_vids_add_by_dev(struct net_device *dev,
 357                          const struct net_device *by_dev)
 358 {
 359         struct vlan_vid_info *vid_info;
 360         struct vlan_info *vlan_info;
 361         int err;
 362
 363         ASSERT_RTNL();
 364
 365         vlan_info = rtnl_dereference(by_dev->vlan_info);
 366         if (!vlan_info)
 367                 return 0;
 368
 369         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 370                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 371                 if (err)
 372                         goto unwind;
 373         }
 374         return 0;
 375
 376 unwind:
 377         list_for_each_entry_continue_reverse(vid_info,
 378                                              &vlan_info->vid_list,
 379                                              list) {
 380                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 381         }
 382
 383         return err;
 384 }
 385 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 386
 387 void vlan_vids_del_by_dev(struct net_device *dev,
 388                           const struct net_device *by_dev)
 389 {
 390         struct vlan_vid_info *vid_info;
 391         struct vlan_info *vlan_info;
 392
 393         ASSERT_RTNL();
 394
 395         vlan_info = rtnl_dereference(by_dev->vlan_info);
 396         if (!vlan_info)
 397                 return;
 398
 399         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 400                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 401 }
 402 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 403
 404 bool vlan_uses_dev(const struct net_device *dev)
 405 {
 406         struct vlan_info *vlan_info;
 407
 408         ASSERT_RTNL();
 409
 410         vlan_info = rtnl_dereference(dev->vlan_info);
 411         if (!vlan_info)
 412                 return false;
 413         return vlan_info->grp.nr_vlan_devs ? true : false;
 414 }
 415 EXPORT_SYMBOL(vlan_uses_dev);