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 #include <linux/netdevice.h>
  18 #include <linux/etherdevice.h>
  19
  20 #define VLAN_HLEN       4               /* The additional bytes (on top of the Ethernet header)
  21                                          * that VLAN requires.
  22                                          */
  23 #define VLAN_ETH_ALEN   6               /* Octets in one ethernet addr   */
  24 #define VLAN_ETH_HLEN   18              /* Total octets in header.       */
  25 #define VLAN_ETH_ZLEN   64              /* Min. octets in frame sans FCS */
  26
  27 /*
  28  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  29  */
  30 #define VLAN_ETH_DATA_LEN       1500    /* Max. octets in payload        */
  31 #define VLAN_ETH_FRAME_LEN      1518    /* Max. octets in frame sans FCS */
  32
  33 /*
  34  *      struct vlan_hdr - vlan header
  35  *      @h_vlan_TCI: priority and VLAN ID
  36  *      @h_vlan_encapsulated_proto: packet type ID or len
  37  */
  38 struct vlan_hdr {
  39         __be16  h_vlan_TCI;
  40         __be16  h_vlan_encapsulated_proto;
  41 };
  42
  43 /**
  44  *      struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  45  *      @h_dest: destination ethernet address
  46  *      @h_source: source ethernet address
  47  *      @h_vlan_proto: ethernet protocol (always 0x8100)
  48  *      @h_vlan_TCI: priority and VLAN ID
  49  *      @h_vlan_encapsulated_proto: packet type ID or len
  50  */
  51 struct vlan_ethhdr {
  52         unsigned char   h_dest[ETH_ALEN];
  53         unsigned char   h_source[ETH_ALEN];
  54         __be16          h_vlan_proto;
  55         __be16          h_vlan_TCI;
  56         __be16          h_vlan_encapsulated_proto;
  57 };
  58
  59 #include <linux/skbuff.h>
  60
  61 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  62 {
  63         return (struct vlan_ethhdr *)skb_mac_header(skb);
  64 }
  65
  66 #define VLAN_VID_MASK   0xfff
  67
  68 /* found in socket.c */
  69 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  70
  71 /* if this changes, algorithm will have to be reworked because this
  72  * depends on completely exhausting the VLAN identifier space.  Thus
  73  * it gives constant time look-up, but in many cases it wastes memory.
  74  */
  75 #define VLAN_GROUP_ARRAY_LEN          4096
  76 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  77 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  78
  79 struct vlan_group {
  80         struct net_device       *real_dev; /* The ethernet(like) device
  81                                             * the vlan is attached to.
  82                                             */
  83         unsigned int            nr_vlans;
  84         struct hlist_node       hlist;  /* linked list */
  85         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  86         struct rcu_head         rcu;
  87 };
  88
  89 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  90                                                        unsigned int vlan_id)
  91 {
  92         struct net_device **array;
  93         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  94         return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
  95 }
  96
  97 static inline void vlan_group_set_device(struct vlan_group *vg,
  98                                          unsigned int vlan_id,
  99                                          struct net_device *dev)
 100 {
 101         struct net_device **array;
 102         if (!vg)
 103                 return;
 104         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 105         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 106 }
 107
 108 /* VLAN tx hw acceleration helpers. */
 109 struct vlan_skb_tx_cookie {
 110         u32     magic;
 111         u32     vlan_tag;
 112 };
 113
 114 #define VLAN_TX_COOKIE_MAGIC    0x564c414e      /* "VLAN" in ascii. */
 115 #define VLAN_TX_SKB_CB(__skb)   ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
 116 #define vlan_tx_tag_present(__skb) \
 117         (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
 118 #define vlan_tx_tag_get(__skb)  (VLAN_TX_SKB_CB(__skb)->vlan_tag)
 119
 120 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 121 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 122 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 123
 124 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 125                              unsigned short vlan_tag, int polling);
 126 #else
 127 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 128 {
 129         BUG();
 130         return NULL;
 131 }
 132
 133 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 134 {
 135         BUG();
 136         return 0;
 137 }
 138
 139 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 140                                     unsigned short vlan_tag, int polling)
 141 {
 142         BUG();
 143         return NET_XMIT_SUCCESS;
 144 }
 145 #endif
 146
 147 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 148                                   struct vlan_group *grp,
 149                                   unsigned short vlan_tag)
 150 {
 151         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
 152 }
 153
 154 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 155                                            struct vlan_group *grp,
 156                                            unsigned short vlan_tag)
 157 {
 158         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
 159 }
 160
 161 /**
 162  * __vlan_put_tag - regular VLAN tag inserting
 163  * @skb: skbuff to tag
 164  * @tag: VLAN tag to insert
 165  *
 166  * Inserts the VLAN tag into @skb as part of the payload
 167  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 168  *
 169  * Following the skb_unshare() example, in case of error, the calling function
 170  * doesn't have to worry about freeing the original skb.
 171  */
 172 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 173 {
 174         struct vlan_ethhdr *veth;
 175
 176         if (skb_headroom(skb) < VLAN_HLEN) {
 177                 struct sk_buff *sk_tmp = skb;
 178                 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
 179                 kfree_skb(sk_tmp);
 180                 if (!skb) {
 181                         printk(KERN_ERR "vlan: failed to realloc headroom\n");
 182                         return NULL;
 183                 }
 184         } else {
 185                 skb = skb_unshare(skb, GFP_ATOMIC);
 186                 if (!skb) {
 187                         printk(KERN_ERR "vlan: failed to unshare skbuff\n");
 188                         return NULL;
 189                 }
 190         }
 191
 192         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 193
 194         /* Move the mac addresses to the beginning of the new header. */
 195         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 196
 197         /* first, the ethernet type */
 198         veth->h_vlan_proto = htons(ETH_P_8021Q);
 199
 200         /* now, the tag */
 201         veth->h_vlan_TCI = htons(tag);
 202
 203         skb->protocol = htons(ETH_P_8021Q);
 204
 205         return skb;
 206 }
 207
 208 /**
 209  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 210  * @skb: skbuff to tag
 211  * @tag: VLAN tag to insert
 212  *
 213  * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
 214  */
 215 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
 216 {
 217         struct vlan_skb_tx_cookie *cookie;
 218
 219         cookie = VLAN_TX_SKB_CB(skb);
 220         cookie->magic = VLAN_TX_COOKIE_MAGIC;
 221         cookie->vlan_tag = tag;
 222
 223         return skb;
 224 }
 225
 226 #define HAVE_VLAN_PUT_TAG
 227
 228 /**
 229  * vlan_put_tag - inserts VLAN tag according to device features
 230  * @skb: skbuff to tag
 231  * @tag: VLAN tag to insert
 232  *
 233  * Assumes skb->dev is the target that will xmit this frame.
 234  * Returns a VLAN tagged skb.
 235  */
 236 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 237 {
 238         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 239                 return __vlan_hwaccel_put_tag(skb, tag);
 240         } else {
 241                 return __vlan_put_tag(skb, tag);
 242         }
 243 }
 244
 245 /**
 246  * __vlan_get_tag - get the VLAN ID that is part of the payload
 247  * @skb: skbuff to query
 248  * @tag: buffer to store vlaue
 249  *
 250  * Returns error if the skb is not of VLAN type
 251  */
 252 static inline int __vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
 253 {
 254         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 255
 256         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 257                 return -EINVAL;
 258         }
 259
 260         *tag = ntohs(veth->h_vlan_TCI);
 261
 262         return 0;
 263 }
 264
 265 /**
 266  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 267  * @skb: skbuff to query
 268  * @tag: buffer to store vlaue
 269  *
 270  * Returns error if @skb->cb[] is not set correctly
 271  */
 272 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 273                                          unsigned short *tag)
 274 {
 275         struct vlan_skb_tx_cookie *cookie;
 276
 277         cookie = VLAN_TX_SKB_CB(skb);
 278         if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
 279                 *tag = cookie->vlan_tag;
 280                 return 0;
 281         } else {
 282                 *tag = 0;
 283                 return -EINVAL;
 284         }
 285 }
 286
 287 #define HAVE_VLAN_GET_TAG
 288
 289 /**
 290  * vlan_get_tag - get the VLAN ID from the skb
 291  * @skb: skbuff to query
 292  * @tag: buffer to store vlaue
 293  *
 294  * Returns error if the skb is not VLAN tagged
 295  */
 296 static inline int vlan_get_tag(const struct sk_buff *skb, unsigned short *tag)
 297 {
 298         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 299                 return __vlan_hwaccel_get_tag(skb, tag);
 300         } else {
 301                 return __vlan_get_tag(skb, tag);
 302         }
 303 }
 304
 305 #endif /* __KERNEL__ */
 306
 307 /* VLAN IOCTLs are found in sockios.h */
 308
 309 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 310 enum vlan_ioctl_cmds {
 311         ADD_VLAN_CMD,
 312         DEL_VLAN_CMD,
 313         SET_VLAN_INGRESS_PRIORITY_CMD,
 314         SET_VLAN_EGRESS_PRIORITY_CMD,
 315         GET_VLAN_INGRESS_PRIORITY_CMD,
 316         GET_VLAN_EGRESS_PRIORITY_CMD,
 317         SET_VLAN_NAME_TYPE_CMD,
 318         SET_VLAN_FLAG_CMD,
 319         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 320         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 321 };
 322
 323 enum vlan_flags {
 324         VLAN_FLAG_REORDER_HDR   = 0x1,
 325         VLAN_FLAG_GVRP          = 0x2,
 326 };
 327
 328 enum vlan_name_types {
 329         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 330         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 331         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 332         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 333         VLAN_NAME_TYPE_HIGHEST
 334 };
 335
 336 struct vlan_ioctl_args {
 337         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 338         char device1[24];
 339
 340         union {
 341                 char device2[24];
 342                 int VID;
 343                 unsigned int skb_priority;
 344                 unsigned int name_type;
 345                 unsigned int bind_type;
 346                 unsigned int flag; /* Matches vlan_dev_info flags */
 347         } u;
 348
 349         short vlan_qos;
 350 };
 351
 352 #endif /* !(_LINUX_IF_VLAN_H_) */