include/linux/if_vlan.h

   1 /*
   2  * VLAN         An implementation of 802.1Q VLAN tagging.
   3  *
   4  * Authors:     Ben Greear <greearb@candelatech.com>
   5  *
   6  *              This program is free software; you can redistribute it and/or
   7  *              modify it under the terms of the GNU General Public License
   8  *              as published by the Free Software Foundation; either version
   9  *              2 of the License, or (at your option) any later version.
  10  *
  11  */
  12
  13 #ifndef _LINUX_IF_VLAN_H_
  14 #define _LINUX_IF_VLAN_H_
  15
  16 #ifdef __KERNEL__
  17
  18 /* externally defined structs */
  19 struct hlist_node;
  20
  21 #include <linux/netdevice.h>
  22 #include <linux/etherdevice.h>
  23
  24 #define VLAN_HLEN       4               /* The additional bytes (on top of the Ethernet header)
  25                                          * that VLAN requires.
  26                                          */
  27 #define VLAN_ETH_ALEN   6               /* Octets in one ethernet addr   */
  28 #define VLAN_ETH_HLEN   18              /* Total octets in header.       */
  29 #define VLAN_ETH_ZLEN   64              /* Min. octets in frame sans FCS */
  30
  31 /*
  32  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  33  */
  34 #define VLAN_ETH_DATA_LEN       1500    /* Max. octets in payload        */
  35 #define VLAN_ETH_FRAME_LEN      1518    /* Max. octets in frame sans FCS */
  36
  37 /*
  38  *      struct vlan_hdr - vlan header
  39  *      @h_vlan_TCI: priority and VLAN ID
  40  *      @h_vlan_encapsulated_proto: packet type ID or len
  41  */
  42 struct vlan_hdr {
  43         __be16  h_vlan_TCI;
  44         __be16  h_vlan_encapsulated_proto;
  45 };
  46
  47 /**
  48  *      struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  49  *      @h_dest: destination ethernet address
  50  *      @h_source: source ethernet address
  51  *      @h_vlan_proto: ethernet protocol (always 0x8100)
  52  *      @h_vlan_TCI: priority and VLAN ID
  53  *      @h_vlan_encapsulated_proto: packet type ID or len
  54  */
  55 struct vlan_ethhdr {
  56         unsigned char   h_dest[ETH_ALEN];
  57         unsigned char   h_source[ETH_ALEN];
  58         __be16          h_vlan_proto;
  59         __be16          h_vlan_TCI;
  60         __be16          h_vlan_encapsulated_proto;
  61 };
  62
  63 #include <linux/skbuff.h>
  64
  65 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  66 {
  67         return (struct vlan_ethhdr *)skb_mac_header(skb);
  68 }
  69
  70 #define VLAN_VID_MASK   0xfff
  71
  72 /* found in socket.c */
  73 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  74
  75 /* if this changes, algorithm will have to be reworked because this
  76  * depends on completely exhausting the VLAN identifier space.  Thus
  77  * it gives constant time look-up, but in many cases it wastes memory.
  78  */
  79 #define VLAN_GROUP_ARRAY_LEN          4096
  80 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  81 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  82
  83 struct vlan_group {
  84         struct net_device       *real_dev; /* The ethernet(like) device
  85                                             * the vlan is attached to.
  86                                             */
  87         unsigned int            nr_vlans;
  88         struct hlist_node       hlist;  /* linked list */
  89         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  90         struct rcu_head         rcu;
  91 };
  92
  93 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  94                                                        unsigned int vlan_id)
  95 {
  96         struct net_device **array;
  97         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  98         return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
  99 }
 100
 101 static inline void vlan_group_set_device(struct vlan_group *vg,
 102                                          unsigned int vlan_id,
 103                                          struct net_device *dev)
 104 {
 105         struct net_device **array;
 106         if (!vg)
 107                 return;
 108         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 109         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 110 }
 111
 112 struct vlan_priority_tci_mapping {
 113         u32 priority;
 114         unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
 115                                   * at provisioning time.
 116                                   * ((skb->priority << 13) & 0xE000)
 117                                   */
 118         struct vlan_priority_tci_mapping *next;
 119 };
 120
 121 /* Holds information that makes sense if this device is a VLAN device. */
 122 struct vlan_dev_info {
 123         /** This will be the mapping that correlates skb->priority to
 124          * 3 bits of VLAN QOS tags...
 125          */
 126         unsigned int nr_ingress_mappings;
 127         u32 ingress_priority_map[8];
 128
 129         unsigned int nr_egress_mappings;
 130         struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
 131
 132         unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
 133         unsigned short flags;          /* (1 << 0) re_order_header   This option will cause the
 134                                         *   VLAN code to move around the ethernet header on
 135                                         *   ingress to make the skb look **exactly** like it
 136                                         *   came in from an ethernet port.  This destroys some of
 137                                         *   the VLAN information in the skb, but it fixes programs
 138                                         *   like DHCP that use packet-filtering and don't understand
 139                                         *   802.1Q
 140                                         */
 141         struct net_device *real_dev;    /* the underlying device/interface */
 142         unsigned char real_dev_addr[ETH_ALEN];
 143         struct proc_dir_entry *dent;    /* Holds the proc data */
 144         unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
 145         unsigned long cnt_encap_on_xmit;      /* How many times did we have to encapsulate the skb on TX. */
 146 };
 147
 148 static inline struct vlan_dev_info *vlan_dev_info(const struct net_device *dev)
 149 {
 150         return netdev_priv(dev);
 151 }
 152
 153 /* inline functions */
 154 static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
 155                                               unsigned short vlan_tag)
 156 {
 157         struct vlan_dev_info *vip = vlan_dev_info(dev);
 158
 159         return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
 160 }
 161
 162 /* VLAN tx hw acceleration helpers. */
 163 struct vlan_skb_tx_cookie {
 164         u32     magic;
 165         u32     vlan_tag;
 166 };
 167
 168 #define VLAN_TX_COOKIE_MAGIC    0x564c414e      /* "VLAN" in ascii. */
 169 #define VLAN_TX_SKB_CB(__skb)   ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
 170 #define vlan_tx_tag_present(__skb) \
 171         (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
 172 #define vlan_tx_tag_get(__skb)  (VLAN_TX_SKB_CB(__skb)->vlan_tag)
 173
 174 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
 175 static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
 176                                     struct vlan_group *grp,
 177                                     unsigned short vlan_tag, int polling)
 178 {
 179         struct net_device_stats *stats;
 180
 181         if (skb_bond_should_drop(skb)) {
 182                 dev_kfree_skb_any(skb);
 183                 return NET_RX_DROP;
 184         }
 185
 186         skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
 187         if (skb->dev == NULL) {
 188                 dev_kfree_skb_any(skb);
 189
 190                 /* Not NET_RX_DROP, this is not being dropped
 191                  * due to congestion.
 192                  */
 193                 return 0;
 194         }
 195
 196         skb->dev->last_rx = jiffies;
 197
 198         stats = &skb->dev->stats;
 199         stats->rx_packets++;
 200         stats->rx_bytes += skb->len;
 201
 202         skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
 203         switch (skb->pkt_type) {
 204         case PACKET_BROADCAST:
 205                 break;
 206
 207         case PACKET_MULTICAST:
 208                 stats->multicast++;
 209                 break;
 210
 211         case PACKET_OTHERHOST:
 212                 /* Our lower layer thinks this is not local, let's make sure.
 213                  * This allows the VLAN to have a different MAC than the underlying
 214                  * device, and still route correctly.
 215                  */
 216                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
 217                                         skb->dev->dev_addr))
 218                         skb->pkt_type = PACKET_HOST;
 219                 break;
 220         };
 221
 222         return (polling ? netif_receive_skb(skb) : netif_rx(skb));
 223 }
 224
 225 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 226                                   struct vlan_group *grp,
 227                                   unsigned short vlan_tag)
 228 {
 229         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
 230 }
 231
 232 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 233                                            struct vlan_group *grp,
 234                                            unsigned short vlan_tag)
 235 {
 236         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
 237 }
 238
 239 /**
 240  * __vlan_put_tag - regular VLAN tag inserting
 241  * @skb: skbuff to tag
 242  * @tag: VLAN tag to insert
 243  *
 244  * Inserts the VLAN tag into @skb as part of the payload
 245  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 246  *
 247  * Following the skb_unshare() example, in case of error, the calling function
 248  * doesn't have to worry about freeing the original skb.
 249  */
 250 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 251 {
 252         struct vlan_ethhdr *veth;
 253
 254         if (skb_headroom(skb) < VLAN_HLEN) {
 255                 struct sk_buff *sk_tmp = skb;
 256                 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
 257                 kfree_skb(sk_tmp);
 258                 if (!skb) {
 259                         printk(KERN_ERR "vlan: failed to realloc headroom\n");
 260                         return NULL;
 261                 }
 262         } else {
 263                 skb = skb_unshare(skb, GFP_ATOMIC);
 264                 if (!skb) {
 265                         printk(KERN_ERR "vlan: failed to unshare skbuff\n");
 266                         return NULL;
 267                 }
 268         }
 269
 270         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 271
 272         /* Move the mac addresses to the beginning of the new header. */
 273         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 274
 275         /* first, the ethernet type */
 276         veth->h_vlan_proto = htons(ETH_P_8021Q);
 277
 278         /* now, the tag */
 279         veth->h_vlan_TCI = htons(tag);
 280
 281         skb->protocol = htons(ETH_P_8021Q);
 282         skb->mac_header -= VLAN_HLEN;
 283         skb->network_header -= VLAN_HLEN;
 284
 285         return skb;
 286 }
 287
 288 /**
 289  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 290  * @skb: skbuff to tag
 291  * @tag: VLAN tag to insert
 292  *
 293  * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
 294  */
 295 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
 296 {
 297         struct vlan_skb_tx_cookie *cookie;
 298
 299         cookie = VLAN_TX_SKB_CB(skb);
 300         cookie->magic = VLAN_TX_COOKIE_MAGIC;
 301         cookie->vlan_tag = tag;
 302
 303         return skb;
 304 }
 305
 306 #define HAVE_VLAN_PUT_TAG
 307
 308 /**
 309  * vlan_put_tag - inserts VLAN tag according to device features
 310  * @skb: skbuff to tag
 311  * @tag: VLAN tag to insert
 312  *
 313  * Assumes skb->dev is the target that will xmit this frame.
 314  * Returns a VLAN tagged skb.
 315  */
 316 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 317 {
 318         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 319                 return __vlan_hwaccel_put_tag(skb, tag);
 320         } else {
 321                 return __vlan_put_tag(skb, tag);
 322         }
 323 }
 324
 325 /**
 326  * __vlan_get_tag - get the VLAN ID that is part of the payload
 327  * @skb: skbuff to query
 328  * @tag: buffer to store vlaue
 329  *
 330  * Returns error if the skb is not of VLAN type
 331  */
 332 static inline int __vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
 333 {
 334         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 335
 336         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 337                 return -EINVAL;
 338         }
 339
 340         *tag = ntohs(veth->h_vlan_TCI);
 341
 342         return 0;
 343 }
 344
 345 /**
 346  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 347  * @skb: skbuff to query
 348  * @tag: buffer to store vlaue
 349  *
 350  * Returns error if @skb->cb[] is not set correctly
 351  */
 352 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 353                                          unsigned short *tag)
 354 {
 355         struct vlan_skb_tx_cookie *cookie;
 356
 357         cookie = VLAN_TX_SKB_CB(skb);
 358         if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
 359                 *tag = cookie->vlan_tag;
 360                 return 0;
 361         } else {
 362                 *tag = 0;
 363                 return -EINVAL;
 364         }
 365 }
 366
 367 #define HAVE_VLAN_GET_TAG
 368
 369 /**
 370  * vlan_get_tag - get the VLAN ID from the skb
 371  * @skb: skbuff to query
 372  * @tag: buffer to store vlaue
 373  *
 374  * Returns error if the skb is not VLAN tagged
 375  */
 376 static inline int vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
 377 {
 378         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 379                 return __vlan_hwaccel_get_tag(skb, tag);
 380         } else {
 381                 return __vlan_get_tag(skb, tag);
 382         }
 383 }
 384
 385 #endif /* __KERNEL__ */
 386
 387 /* VLAN IOCTLs are found in sockios.h */
 388
 389 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 390 enum vlan_ioctl_cmds {
 391         ADD_VLAN_CMD,
 392         DEL_VLAN_CMD,
 393         SET_VLAN_INGRESS_PRIORITY_CMD,
 394         SET_VLAN_EGRESS_PRIORITY_CMD,
 395         GET_VLAN_INGRESS_PRIORITY_CMD,
 396         GET_VLAN_EGRESS_PRIORITY_CMD,
 397         SET_VLAN_NAME_TYPE_CMD,
 398         SET_VLAN_FLAG_CMD,
 399         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 400         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 401 };
 402
 403 enum vlan_flags {
 404         VLAN_FLAG_REORDER_HDR   = 0x1,
 405 };
 406
 407 enum vlan_name_types {
 408         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 409         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 410         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 411         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 412         VLAN_NAME_TYPE_HIGHEST
 413 };
 414
 415 struct vlan_ioctl_args {
 416         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 417         char device1[24];
 418
 419         union {
 420                 char device2[24];
 421                 int VID;
 422                 unsigned int skb_priority;
 423                 unsigned int name_type;
 424                 unsigned int bind_type;
 425                 unsigned int flag; /* Matches vlan_dev_info flags */
 426         } u;
 427
 428         short vlan_qos;
 429 };
 430
 431 #endif /* !(_LINUX_IF_VLAN_H_) */