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, bool last_handler)
   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, vlan_id);
  16         if (!vlan_dev) {
  17                 /* Only the last call to vlan_do_receive() should change
  18                  * pkt_type to PACKET_OTHERHOST
  19                  */
  20                 if (vlan_id && last_handler)
  21                         skb->pkt_type = PACKET_OTHERHOST;
  22                 return false;
  23         }
  24
  25         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  26         if (unlikely(!skb))
  27                 return false;
  28
  29         skb->dev = vlan_dev;
  30         if (skb->pkt_type == PACKET_OTHERHOST) {
  31                 /* Our lower layer thinks this is not local, let's make sure.
  32                  * This allows the VLAN to have a different MAC than the
  33                  * underlying device, and still route correctly. */
  34                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
  35                                         vlan_dev->dev_addr))
  36                         skb->pkt_type = PACKET_HOST;
  37         }
  38
  39         if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR)) {
  40                 unsigned int offset = skb->data - skb_mac_header(skb);
  41
  42                 /*
  43                  * vlan_insert_tag expect skb->data pointing to mac header.
  44                  * So change skb->data before calling it and change back to
  45                  * original position later
  46                  */
  47                 skb_push(skb, offset);
  48                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_tci);
  49                 if (!skb)
  50                         return false;
  51                 skb_pull(skb, offset + VLAN_HLEN);
  52                 skb_reset_mac_len(skb);
  53         }
  54
  55         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  56         skb->vlan_tci = 0;
  57
  58         rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
  59
  60         u64_stats_update_begin(&rx_stats->syncp);
  61         rx_stats->rx_packets++;
  62         rx_stats->rx_bytes += skb->len;
  63         if (skb->pkt_type == PACKET_MULTICAST)
  64                 rx_stats->rx_multicast++;
  65         u64_stats_update_end(&rx_stats->syncp);
  66
  67         return true;
  68 }
  69
  70 /* Must be invoked with rcu_read_lock or with RTNL. */
  71 struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  72                                         u16 vlan_id)
  73 {
  74         struct vlan_info *vlan_info = rcu_dereference_rtnl(real_dev->vlan_info);
  75
  76         if (vlan_info) {
  77                 return vlan_group_get_device(&vlan_info->grp, vlan_id);
  78         } else {
  79                 /*
  80                  * Bonding slaves do not have grp assigned to themselves.
  81                  * Grp is assigned to bonding master instead.
  82                  */
  83                 if (netif_is_bond_slave(real_dev))
  84                         return __vlan_find_dev_deep(real_dev->master, vlan_id);
  85         }
  86
  87         return NULL;
  88 }
  89 EXPORT_SYMBOL(__vlan_find_dev_deep);
  90
  91 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  92 {
  93         return vlan_dev_priv(dev)->real_dev;
  94 }
  95 EXPORT_SYMBOL(vlan_dev_real_dev);
  96
  97 u16 vlan_dev_vlan_id(const struct net_device *dev)
  98 {
  99         return vlan_dev_priv(dev)->vlan_id;
 100 }
 101 EXPORT_SYMBOL(vlan_dev_vlan_id);
 102
 103 static struct sk_buff *vlan_reorder_header(struct sk_buff *skb)
 104 {
 105         if (skb_cow(skb, skb_headroom(skb)) < 0)
 106                 return NULL;
 107         memmove(skb->data - ETH_HLEN, skb->data - VLAN_ETH_HLEN, 2 * ETH_ALEN);
 108         skb->mac_header += VLAN_HLEN;
 109         skb_reset_mac_len(skb);
 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, 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         return skb;
 144
 145 err_free:
 146         kfree_skb(skb);
 147         return NULL;
 148 }
 149
 150
 151 /*
 152  * vlan info and vid list
 153  */
 154
 155 static void vlan_group_free(struct vlan_group *grp)
 156 {
 157         int i;
 158
 159         for (i = 0; i < VLAN_GROUP_ARRAY_SPLIT_PARTS; i++)
 160                 kfree(grp->vlan_devices_arrays[i]);
 161 }
 162
 163 static void vlan_info_free(struct vlan_info *vlan_info)
 164 {
 165         vlan_group_free(&vlan_info->grp);
 166         kfree(vlan_info);
 167 }
 168
 169 static void vlan_info_rcu_free(struct rcu_head *rcu)
 170 {
 171         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 172 }
 173
 174 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 175 {
 176         struct vlan_info *vlan_info;
 177
 178         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 179         if (!vlan_info)
 180                 return NULL;
 181
 182         vlan_info->real_dev = dev;
 183         INIT_LIST_HEAD(&vlan_info->vid_list);
 184         return vlan_info;
 185 }
 186
 187 struct vlan_vid_info {
 188         struct list_head list;
 189         unsigned short vid;
 190         int refcount;
 191 };
 192
 193 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 194                                                unsigned short vid)
 195 {
 196         struct vlan_vid_info *vid_info;
 197
 198         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 199                 if (vid_info->vid == vid)
 200                         return vid_info;
 201         }
 202         return NULL;
 203 }
 204
 205 static struct vlan_vid_info *vlan_vid_info_alloc(unsigned short vid)
 206 {
 207         struct vlan_vid_info *vid_info;
 208
 209         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 210         if (!vid_info)
 211                 return NULL;
 212         vid_info->vid = vid;
 213
 214         return vid_info;
 215 }
 216
 217 static int __vlan_vid_add(struct vlan_info *vlan_info, unsigned short vid,
 218                           struct vlan_vid_info **pvid_info)
 219 {
 220         struct net_device *dev = vlan_info->real_dev;
 221         const struct net_device_ops *ops = dev->netdev_ops;
 222         struct vlan_vid_info *vid_info;
 223         int err;
 224
 225         vid_info = vlan_vid_info_alloc(vid);
 226         if (!vid_info)
 227                 return -ENOMEM;
 228
 229         if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 230             ops->ndo_vlan_rx_add_vid) {
 231                 err =  ops->ndo_vlan_rx_add_vid(dev, vid);
 232                 if (err) {
 233                         kfree(vid_info);
 234                         return err;
 235                 }
 236         }
 237         list_add(&vid_info->list, &vlan_info->vid_list);
 238         vlan_info->nr_vids++;
 239         *pvid_info = vid_info;
 240         return 0;
 241 }
 242
 243 int vlan_vid_add(struct net_device *dev, unsigned short vid)
 244 {
 245         struct vlan_info *vlan_info;
 246         struct vlan_vid_info *vid_info;
 247         bool vlan_info_created = false;
 248         int err;
 249
 250         ASSERT_RTNL();
 251
 252         vlan_info = rtnl_dereference(dev->vlan_info);
 253         if (!vlan_info) {
 254                 vlan_info = vlan_info_alloc(dev);
 255                 if (!vlan_info)
 256                         return -ENOMEM;
 257                 vlan_info_created = true;
 258         }
 259         vid_info = vlan_vid_info_get(vlan_info, vid);
 260         if (!vid_info) {
 261                 err = __vlan_vid_add(vlan_info, vid, &vid_info);
 262                 if (err)
 263                         goto out_free_vlan_info;
 264         }
 265         vid_info->refcount++;
 266
 267         if (vlan_info_created)
 268                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 269
 270         return 0;
 271
 272 out_free_vlan_info:
 273         if (vlan_info_created)
 274                 kfree(vlan_info);
 275         return err;
 276 }
 277 EXPORT_SYMBOL(vlan_vid_add);
 278
 279 static void __vlan_vid_del(struct vlan_info *vlan_info,
 280                            struct vlan_vid_info *vid_info)
 281 {
 282         struct net_device *dev = vlan_info->real_dev;
 283         const struct net_device_ops *ops = dev->netdev_ops;
 284         unsigned short vid = vid_info->vid;
 285         int err;
 286
 287         if ((dev->features & NETIF_F_HW_VLAN_FILTER) &&
 288              ops->ndo_vlan_rx_kill_vid) {
 289                 err = ops->ndo_vlan_rx_kill_vid(dev, vid);
 290                 if (err) {
 291                         pr_warn("failed to kill vid %d for device %s\n",
 292                                 vid, dev->name);
 293                 }
 294         }
 295         list_del(&vid_info->list);
 296         kfree(vid_info);
 297         vlan_info->nr_vids--;
 298 }
 299
 300 void vlan_vid_del(struct net_device *dev, unsigned short vid)
 301 {
 302         struct vlan_info *vlan_info;
 303         struct vlan_vid_info *vid_info;
 304
 305         ASSERT_RTNL();
 306
 307         vlan_info = rtnl_dereference(dev->vlan_info);
 308         if (!vlan_info)
 309                 return;
 310
 311         vid_info = vlan_vid_info_get(vlan_info, vid);
 312         if (!vid_info)
 313                 return;
 314         vid_info->refcount--;
 315         if (vid_info->refcount == 0) {
 316                 __vlan_vid_del(vlan_info, vid_info);
 317                 if (vlan_info->nr_vids == 0) {
 318                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 319                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 320                 }
 321         }
 322 }
 323 EXPORT_SYMBOL(vlan_vid_del);