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 #define VLAN_NAME "vlan"
  76
  77 /* if this changes, algorithm will have to be reworked because this
  78  * depends on completely exhausting the VLAN identifier space.  Thus
  79  * it gives constant time look-up, but in many cases it wastes memory.
  80  */
  81 #define VLAN_GROUP_ARRAY_LEN          4096
  82 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  83 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  84
  85 struct vlan_group {
  86         int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
  87         struct hlist_node       hlist;  /* linked list */
  88         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  89         struct rcu_head         rcu;
  90 };
  91
  92 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  93                                                        unsigned int vlan_id)
  94 {
  95         struct net_device **array;
  96         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  97         return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
  98 }
  99
 100 static inline void vlan_group_set_device(struct vlan_group *vg,
 101                                          unsigned int vlan_id,
 102                                          struct net_device *dev)
 103 {
 104         struct net_device **array;
 105         if (!vg)
 106                 return;
 107         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 108         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 109 }
 110
 111 struct vlan_priority_tci_mapping {
 112         u32 priority;
 113         unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
 114                                   * at provisioning time.
 115                                   * ((skb->priority << 13) & 0xE000)
 116                                   */
 117         struct vlan_priority_tci_mapping *next;
 118 };
 119
 120 /* Holds information that makes sense if this device is a VLAN device. */
 121 struct vlan_dev_info {
 122         /** This will be the mapping that correlates skb->priority to
 123          * 3 bits of VLAN QOS tags...
 124          */
 125         unsigned int nr_ingress_mappings;
 126         u32 ingress_priority_map[8];
 127
 128         unsigned int nr_egress_mappings;
 129         struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
 130
 131         unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
 132         unsigned short flags;          /* (1 << 0) re_order_header   This option will cause the
 133                                         *   VLAN code to move around the ethernet header on
 134                                         *   ingress to make the skb look **exactly** like it
 135                                         *   came in from an ethernet port.  This destroys some of
 136                                         *   the VLAN information in the skb, but it fixes programs
 137                                         *   like DHCP that use packet-filtering and don't understand
 138                                         *   802.1Q
 139                                         */
 140         struct net_device *real_dev;    /* the underlying device/interface */
 141         unsigned char real_dev_addr[ETH_ALEN];
 142         struct proc_dir_entry *dent;    /* Holds the proc data */
 143         unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
 144         unsigned long cnt_encap_on_xmit;      /* How many times did we have to encapsulate the skb on TX. */
 145         struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
 146 };
 147
 148 #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
 149
 150 /* inline functions */
 151
 152 static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
 153 {
 154         return &(VLAN_DEV_INFO(dev)->dev_stats);
 155 }
 156
 157 static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
 158                                               unsigned short vlan_tag)
 159 {
 160         struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
 161
 162         return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
 163 }
 164
 165 /* VLAN tx hw acceleration helpers. */
 166 struct vlan_skb_tx_cookie {
 167         u32     magic;
 168         u32     vlan_tag;
 169 };
 170
 171 #define VLAN_TX_COOKIE_MAGIC    0x564c414e      /* "VLAN" in ascii. */
 172 #define VLAN_TX_SKB_CB(__skb)   ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
 173 #define vlan_tx_tag_present(__skb) \
 174         (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
 175 #define vlan_tx_tag_get(__skb)  (VLAN_TX_SKB_CB(__skb)->vlan_tag)
 176
 177 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
 178 static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
 179                                     struct vlan_group *grp,
 180                                     unsigned short vlan_tag, int polling)
 181 {
 182         struct net_device_stats *stats;
 183
 184         if (skb_bond_should_drop(skb)) {
 185                 dev_kfree_skb_any(skb);
 186                 return NET_RX_DROP;
 187         }
 188
 189         skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
 190         if (skb->dev == NULL) {
 191                 dev_kfree_skb_any(skb);
 192
 193                 /* Not NET_RX_DROP, this is not being dropped
 194                  * due to congestion.
 195                  */
 196                 return 0;
 197         }
 198
 199         skb->dev->last_rx = jiffies;
 200
 201         stats = vlan_dev_get_stats(skb->dev);
 202         stats->rx_packets++;
 203         stats->rx_bytes += skb->len;
 204
 205         skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
 206         switch (skb->pkt_type) {
 207         case PACKET_BROADCAST:
 208                 break;
 209
 210         case PACKET_MULTICAST:
 211                 stats->multicast++;
 212                 break;
 213
 214         case PACKET_OTHERHOST:
 215                 /* Our lower layer thinks this is not local, let's make sure.
 216                  * This allows the VLAN to have a different MAC than the underlying
 217                  * device, and still route correctly.
 218                  */
 219                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
 220                                         skb->dev->dev_addr))
 221                         skb->pkt_type = PACKET_HOST;
 222                 break;
 223         };
 224
 225         return (polling ? netif_receive_skb(skb) : netif_rx(skb));
 226 }
 227
 228 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 229                                   struct vlan_group *grp,
 230                                   unsigned short vlan_tag)
 231 {
 232         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
 233 }
 234
 235 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 236                                            struct vlan_group *grp,
 237                                            unsigned short vlan_tag)
 238 {
 239         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
 240 }
 241
 242 /**
 243  * __vlan_put_tag - regular VLAN tag inserting
 244  * @skb: skbuff to tag
 245  * @tag: VLAN tag to insert
 246  *
 247  * Inserts the VLAN tag into @skb as part of the payload
 248  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 249  *
 250  * Following the skb_unshare() example, in case of error, the calling function
 251  * doesn't have to worry about freeing the original skb.
 252  */
 253 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 254 {
 255         struct vlan_ethhdr *veth;
 256
 257         if (skb_headroom(skb) < VLAN_HLEN) {
 258                 struct sk_buff *sk_tmp = skb;
 259                 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
 260                 kfree_skb(sk_tmp);
 261                 if (!skb) {
 262                         printk(KERN_ERR "vlan: failed to realloc headroom\n");
 263                         return NULL;
 264                 }
 265         } else {
 266                 skb = skb_unshare(skb, GFP_ATOMIC);
 267                 if (!skb) {
 268                         printk(KERN_ERR "vlan: failed to unshare skbuff\n");
 269                         return NULL;
 270                 }
 271         }
 272
 273         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 274
 275         /* Move the mac addresses to the beginning of the new header. */
 276         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 277
 278         /* first, the ethernet type */
 279         veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
 280
 281         /* now, the tag */
 282         veth->h_vlan_TCI = htons(tag);
 283
 284         skb->protocol = __constant_htons(ETH_P_8021Q);
 285         skb->mac_header -= VLAN_HLEN;
 286         skb->network_header -= VLAN_HLEN;
 287
 288         return skb;
 289 }
 290
 291 /**
 292  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 293  * @skb: skbuff to tag
 294  * @tag: VLAN tag to insert
 295  *
 296  * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
 297  */
 298 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
 299 {
 300         struct vlan_skb_tx_cookie *cookie;
 301
 302         cookie = VLAN_TX_SKB_CB(skb);
 303         cookie->magic = VLAN_TX_COOKIE_MAGIC;
 304         cookie->vlan_tag = tag;
 305
 306         return skb;
 307 }
 308
 309 #define HAVE_VLAN_PUT_TAG
 310
 311 /**
 312  * vlan_put_tag - inserts VLAN tag according to device features
 313  * @skb: skbuff to tag
 314  * @tag: VLAN tag to insert
 315  *
 316  * Assumes skb->dev is the target that will xmit this frame.
 317  * Returns a VLAN tagged skb.
 318  */
 319 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 320 {
 321         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 322                 return __vlan_hwaccel_put_tag(skb, tag);
 323         } else {
 324                 return __vlan_put_tag(skb, tag);
 325         }
 326 }
 327
 328 /**
 329  * __vlan_get_tag - get the VLAN ID that is part of the payload
 330  * @skb: skbuff to query
 331  * @tag: buffer to store vlaue
 332  *
 333  * Returns error if the skb is not of VLAN type
 334  */
 335 static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 336 {
 337         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 338
 339         if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
 340                 return -EINVAL;
 341         }
 342
 343         *tag = ntohs(veth->h_vlan_TCI);
 344
 345         return 0;
 346 }
 347
 348 /**
 349  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 350  * @skb: skbuff to query
 351  * @tag: buffer to store vlaue
 352  *
 353  * Returns error if @skb->cb[] is not set correctly
 354  */
 355 static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
 356 {
 357         struct vlan_skb_tx_cookie *cookie;
 358
 359         cookie = VLAN_TX_SKB_CB(skb);
 360         if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
 361                 *tag = cookie->vlan_tag;
 362                 return 0;
 363         } else {
 364                 *tag = 0;
 365                 return -EINVAL;
 366         }
 367 }
 368
 369 #define HAVE_VLAN_GET_TAG
 370
 371 /**
 372  * vlan_get_tag - get the VLAN ID from the skb
 373  * @skb: skbuff to query
 374  * @tag: buffer to store vlaue
 375  *
 376  * Returns error if the skb is not VLAN tagged
 377  */
 378 static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 379 {
 380         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 381                 return __vlan_hwaccel_get_tag(skb, tag);
 382         } else {
 383                 return __vlan_get_tag(skb, tag);
 384         }
 385 }
 386
 387 #endif /* __KERNEL__ */
 388
 389 /* VLAN IOCTLs are found in sockios.h */
 390
 391 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 392 enum vlan_ioctl_cmds {
 393         ADD_VLAN_CMD,
 394         DEL_VLAN_CMD,
 395         SET_VLAN_INGRESS_PRIORITY_CMD,
 396         SET_VLAN_EGRESS_PRIORITY_CMD,
 397         GET_VLAN_INGRESS_PRIORITY_CMD,
 398         GET_VLAN_EGRESS_PRIORITY_CMD,
 399         SET_VLAN_NAME_TYPE_CMD,
 400         SET_VLAN_FLAG_CMD,
 401         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 402         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 403 };
 404
 405 enum vlan_flags {
 406         VLAN_FLAG_REORDER_HDR   = 0x1,
 407 };
 408
 409 enum vlan_name_types {
 410         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 411         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 412         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 413         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 414         VLAN_NAME_TYPE_HIGHEST
 415 };
 416
 417 struct vlan_ioctl_args {
 418         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 419         char device1[24];
 420
 421         union {
 422                 char device2[24];
 423                 int VID;
 424                 unsigned int skb_priority;
 425                 unsigned int name_type;
 426                 unsigned int bind_type;
 427                 unsigned int flag; /* Matches vlan_dev_info flags */
 428         } u;
 429
 430         short vlan_qos;
 431 };
 432
 433 #endif /* !(_LINUX_IF_VLAN_H_) */