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