net/8021q/vlan_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/skbuff.h>
   3 #include <linux/netdevice.h>
   4 #include <linux/if_vlan.h>
   5 #include <linux/netpoll.h>
   6 #include <linux/export.h>
   7 #include "vlan.h"
   8
   9 bool vlan_do_receive(struct sk_buff **skbp)
  10 {
  11         struct sk_buff *skb = *skbp;
  12         __be16 vlan_proto = skb->vlan_proto;
  13         u16 vlan_id = skb_vlan_tag_get_id(skb);
  14         struct net_device *vlan_dev;
  15         struct vlan_pcpu_stats *rx_stats;
  16
  17         vlan_dev = vlan_find_dev(skb->dev, vlan_proto, vlan_id);
  18         if (!vlan_dev)
  19                 return false;
  20
  21         skb = *skbp = skb_share_check(skb, GFP_ATOMIC);
  22         if (unlikely(!skb))
  23                 return false;
  24
  25         if (unlikely(!(vlan_dev->flags & IFF_UP))) {
  26                 kfree_skb(skb);
  27                 *skbp = NULL;
  28                 return false;
  29         }
  30
  31         skb->dev = vlan_dev;
  32         if (unlikely(skb->pkt_type == PACKET_OTHERHOST)) {
  33                 /* Our lower layer thinks this is not local, let's make sure.
  34                  * This allows the VLAN to have a different MAC than the
  35                  * underlying device, and still route correctly. */
  36                 if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, vlan_dev->dev_addr))
  37                         skb->pkt_type = PACKET_HOST;
  38         }
  39
  40         if (!(vlan_dev_priv(vlan_dev)->flags & VLAN_FLAG_REORDER_HDR) &&
  41             !netif_is_macvlan_port(vlan_dev) &&
  42             !netif_is_bridge_port(vlan_dev)) {
  43                 unsigned int offset = skb->data - skb_mac_header(skb);
  44
  45                 /*
  46                  * vlan_insert_tag expect skb->data pointing to mac header.
  47                  * So change skb->data before calling it and change back to
  48                  * original position later
  49                  */
  50                 skb_push(skb, offset);
  51                 skb = *skbp = vlan_insert_tag(skb, skb->vlan_proto,
  52                                               skb->vlan_tci);
  53                 if (!skb)
  54                         return false;
  55                 skb_pull(skb, offset + VLAN_HLEN);
  56                 skb_reset_mac_len(skb);
  57         }
  58
  59         skb->priority = vlan_get_ingress_priority(vlan_dev, skb->vlan_tci);
  60         skb->vlan_tci = 0;
  61
  62         rx_stats = this_cpu_ptr(vlan_dev_priv(vlan_dev)->vlan_pcpu_stats);
  63
  64         u64_stats_update_begin(&rx_stats->syncp);
  65         rx_stats->rx_packets++;
  66         rx_stats->rx_bytes += skb->len;
  67         if (skb->pkt_type == PACKET_MULTICAST)
  68                 rx_stats->rx_multicast++;
  69         u64_stats_update_end(&rx_stats->syncp);
  70
  71         return true;
  72 }
  73
  74 /* Must be invoked with rcu_read_lock. */
  75 struct net_device *__vlan_find_dev_deep_rcu(struct net_device *dev,
  76                                         __be16 vlan_proto, u16 vlan_id)
  77 {
  78         struct vlan_info *vlan_info = rcu_dereference(dev->vlan_info);
  79
  80         if (vlan_info) {
  81                 return vlan_group_get_device(&vlan_info->grp,
  82                                              vlan_proto, vlan_id);
  83         } else {
  84                 /*
  85                  * Lower devices of master uppers (bonding, team) do not have
  86                  * grp assigned to themselves. Grp is assigned to upper device
  87                  * instead.
  88                  */
  89                 struct net_device *upper_dev;
  90
  91                 upper_dev = netdev_master_upper_dev_get_rcu(dev);
  92                 if (upper_dev)
  93                         return __vlan_find_dev_deep_rcu(upper_dev,
  94                                                     vlan_proto, vlan_id);
  95         }
  96
  97         return NULL;
  98 }
  99 EXPORT_SYMBOL(__vlan_find_dev_deep_rcu);
 100
 101 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 102 {
 103         struct net_device *ret = vlan_dev_priv(dev)->real_dev;
 104
 105         while (is_vlan_dev(ret))
 106                 ret = vlan_dev_priv(ret)->real_dev;
 107
 108         return ret;
 109 }
 110 EXPORT_SYMBOL(vlan_dev_real_dev);
 111
 112 u16 vlan_dev_vlan_id(const struct net_device *dev)
 113 {
 114         return vlan_dev_priv(dev)->vlan_id;
 115 }
 116 EXPORT_SYMBOL(vlan_dev_vlan_id);
 117
 118 __be16 vlan_dev_vlan_proto(const struct net_device *dev)
 119 {
 120         return vlan_dev_priv(dev)->vlan_proto;
 121 }
 122 EXPORT_SYMBOL(vlan_dev_vlan_proto);
 123
 124 /*
 125  * vlan info and vid list
 126  */
 127
 128 static void vlan_group_free(struct vlan_group *grp)
 129 {
 130         int i, j;
 131
 132         for (i = 0; i < VLAN_PROTO_NUM; i++)
 133                 for (j = 0; j < VLAN_GROUP_ARRAY_SPLIT_PARTS; j++)
 134                         kfree(grp->vlan_devices_arrays[i][j]);
 135 }
 136
 137 static void vlan_info_free(struct vlan_info *vlan_info)
 138 {
 139         vlan_group_free(&vlan_info->grp);
 140         kfree(vlan_info);
 141 }
 142
 143 static void vlan_info_rcu_free(struct rcu_head *rcu)
 144 {
 145         vlan_info_free(container_of(rcu, struct vlan_info, rcu));
 146 }
 147
 148 static struct vlan_info *vlan_info_alloc(struct net_device *dev)
 149 {
 150         struct vlan_info *vlan_info;
 151
 152         vlan_info = kzalloc(sizeof(struct vlan_info), GFP_KERNEL);
 153         if (!vlan_info)
 154                 return NULL;
 155
 156         vlan_info->real_dev = dev;
 157         INIT_LIST_HEAD(&vlan_info->vid_list);
 158         return vlan_info;
 159 }
 160
 161 struct vlan_vid_info {
 162         struct list_head list;
 163         __be16 proto;
 164         u16 vid;
 165         int refcount;
 166 };
 167
 168 static bool vlan_hw_filter_capable(const struct net_device *dev,
 169                                      const struct vlan_vid_info *vid_info)
 170 {
 171         if (vid_info->proto == htons(ETH_P_8021Q) &&
 172             dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
 173                 return true;
 174         if (vid_info->proto == htons(ETH_P_8021AD) &&
 175             dev->features & NETIF_F_HW_VLAN_STAG_FILTER)
 176                 return true;
 177         return false;
 178 }
 179
 180 static struct vlan_vid_info *vlan_vid_info_get(struct vlan_info *vlan_info,
 181                                                __be16 proto, u16 vid)
 182 {
 183         struct vlan_vid_info *vid_info;
 184
 185         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 186                 if (vid_info->proto == proto && vid_info->vid == vid)
 187                         return vid_info;
 188         }
 189         return NULL;
 190 }
 191
 192 static struct vlan_vid_info *vlan_vid_info_alloc(__be16 proto, u16 vid)
 193 {
 194         struct vlan_vid_info *vid_info;
 195
 196         vid_info = kzalloc(sizeof(struct vlan_vid_info), GFP_KERNEL);
 197         if (!vid_info)
 198                 return NULL;
 199         vid_info->proto = proto;
 200         vid_info->vid = vid;
 201
 202         return vid_info;
 203 }
 204
 205 static int __vlan_vid_add(struct vlan_info *vlan_info, __be16 proto, u16 vid,
 206                           struct vlan_vid_info **pvid_info)
 207 {
 208         struct net_device *dev = vlan_info->real_dev;
 209         const struct net_device_ops *ops = dev->netdev_ops;
 210         struct vlan_vid_info *vid_info;
 211         int err;
 212
 213         vid_info = vlan_vid_info_alloc(proto, vid);
 214         if (!vid_info)
 215                 return -ENOMEM;
 216
 217         if (vlan_hw_filter_capable(dev, vid_info)) {
 218                 if (netif_device_present(dev))
 219                         err = ops->ndo_vlan_rx_add_vid(dev, proto, vid);
 220                 else
 221                         err = -ENODEV;
 222                 if (err) {
 223                         kfree(vid_info);
 224                         return err;
 225                 }
 226         }
 227         list_add(&vid_info->list, &vlan_info->vid_list);
 228         vlan_info->nr_vids++;
 229         *pvid_info = vid_info;
 230         return 0;
 231 }
 232
 233 int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 234 {
 235         struct vlan_info *vlan_info;
 236         struct vlan_vid_info *vid_info;
 237         bool vlan_info_created = false;
 238         int err;
 239
 240         ASSERT_RTNL();
 241
 242         vlan_info = rtnl_dereference(dev->vlan_info);
 243         if (!vlan_info) {
 244                 vlan_info = vlan_info_alloc(dev);
 245                 if (!vlan_info)
 246                         return -ENOMEM;
 247                 vlan_info_created = true;
 248         }
 249         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 250         if (!vid_info) {
 251                 err = __vlan_vid_add(vlan_info, proto, vid, &vid_info);
 252                 if (err)
 253                         goto out_free_vlan_info;
 254         }
 255         vid_info->refcount++;
 256
 257         if (vlan_info_created)
 258                 rcu_assign_pointer(dev->vlan_info, vlan_info);
 259
 260         return 0;
 261
 262 out_free_vlan_info:
 263         if (vlan_info_created)
 264                 kfree(vlan_info);
 265         return err;
 266 }
 267 EXPORT_SYMBOL(vlan_vid_add);
 268
 269 static void __vlan_vid_del(struct vlan_info *vlan_info,
 270                            struct vlan_vid_info *vid_info)
 271 {
 272         struct net_device *dev = vlan_info->real_dev;
 273         const struct net_device_ops *ops = dev->netdev_ops;
 274         __be16 proto = vid_info->proto;
 275         u16 vid = vid_info->vid;
 276         int err;
 277
 278         if (vlan_hw_filter_capable(dev, vid_info)) {
 279                 if (netif_device_present(dev))
 280                         err = ops->ndo_vlan_rx_kill_vid(dev, proto, vid);
 281                 else
 282                         err = -ENODEV;
 283                 if (err) {
 284                         pr_warn("failed to kill vid %04x/%d for device %s\n",
 285                                 proto, vid, dev->name);
 286                 }
 287         }
 288         list_del(&vid_info->list);
 289         kfree(vid_info);
 290         vlan_info->nr_vids--;
 291 }
 292
 293 void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 294 {
 295         struct vlan_info *vlan_info;
 296         struct vlan_vid_info *vid_info;
 297
 298         ASSERT_RTNL();
 299
 300         vlan_info = rtnl_dereference(dev->vlan_info);
 301         if (!vlan_info)
 302                 return;
 303
 304         vid_info = vlan_vid_info_get(vlan_info, proto, vid);
 305         if (!vid_info)
 306                 return;
 307         vid_info->refcount--;
 308         if (vid_info->refcount == 0) {
 309                 __vlan_vid_del(vlan_info, vid_info);
 310                 if (vlan_info->nr_vids == 0) {
 311                         RCU_INIT_POINTER(dev->vlan_info, NULL);
 312                         call_rcu(&vlan_info->rcu, vlan_info_rcu_free);
 313                 }
 314         }
 315 }
 316 EXPORT_SYMBOL(vlan_vid_del);
 317
 318 int vlan_vids_add_by_dev(struct net_device *dev,
 319                          const struct net_device *by_dev)
 320 {
 321         struct vlan_vid_info *vid_info;
 322         struct vlan_info *vlan_info;
 323         int err;
 324
 325         ASSERT_RTNL();
 326
 327         vlan_info = rtnl_dereference(by_dev->vlan_info);
 328         if (!vlan_info)
 329                 return 0;
 330
 331         list_for_each_entry(vid_info, &vlan_info->vid_list, list) {
 332                 err = vlan_vid_add(dev, vid_info->proto, vid_info->vid);
 333                 if (err)
 334                         goto unwind;
 335         }
 336         return 0;
 337
 338 unwind:
 339         list_for_each_entry_continue_reverse(vid_info,
 340                                              &vlan_info->vid_list,
 341                                              list) {
 342                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 343         }
 344
 345         return err;
 346 }
 347 EXPORT_SYMBOL(vlan_vids_add_by_dev);
 348
 349 void vlan_vids_del_by_dev(struct net_device *dev,
 350                           const struct net_device *by_dev)
 351 {
 352         struct vlan_vid_info *vid_info;
 353         struct vlan_info *vlan_info;
 354
 355         ASSERT_RTNL();
 356
 357         vlan_info = rtnl_dereference(by_dev->vlan_info);
 358         if (!vlan_info)
 359                 return;
 360
 361         list_for_each_entry(vid_info, &vlan_info->vid_list, list)
 362                 vlan_vid_del(dev, vid_info->proto, vid_info->vid);
 363 }
 364 EXPORT_SYMBOL(vlan_vids_del_by_dev);
 365
 366 bool vlan_uses_dev(const struct net_device *dev)
 367 {
 368         struct vlan_info *vlan_info;
 369
 370         ASSERT_RTNL();
 371
 372         vlan_info = rtnl_dereference(dev->vlan_info);
 373         if (!vlan_info)
 374                 return false;
 375         return vlan_info->grp.nr_vlan_devs ? true : false;
 376 }
 377 EXPORT_SYMBOL(vlan_uses_dev);