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 #include <linux/rtnetlink.h>
  20
  21 #define VLAN_HLEN       4               /* The additional bytes (on top of the Ethernet header)
  22                                          * that VLAN requires.
  23                                          */
  24 #define VLAN_ETH_ALEN   6               /* Octets in one ethernet addr   */
  25 #define VLAN_ETH_HLEN   18              /* Total octets in header.       */
  26 #define VLAN_ETH_ZLEN   64              /* Min. octets in frame sans FCS */
  27
  28 /*
  29  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  30  */
  31 #define VLAN_ETH_DATA_LEN       1500    /* Max. octets in payload        */
  32 #define VLAN_ETH_FRAME_LEN      1518    /* Max. octets in frame sans FCS */
  33
  34 /*
  35  *      struct vlan_hdr - vlan header
  36  *      @h_vlan_TCI: priority and VLAN ID
  37  *      @h_vlan_encapsulated_proto: packet type ID or len
  38  */
  39 struct vlan_hdr {
  40         __be16  h_vlan_TCI;
  41         __be16  h_vlan_encapsulated_proto;
  42 };
  43
  44 /**
  45  *      struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  46  *      @h_dest: destination ethernet address
  47  *      @h_source: source ethernet address
  48  *      @h_vlan_proto: ethernet protocol (always 0x8100)
  49  *      @h_vlan_TCI: priority and VLAN ID
  50  *      @h_vlan_encapsulated_proto: packet type ID or len
  51  */
  52 struct vlan_ethhdr {
  53         unsigned char   h_dest[ETH_ALEN];
  54         unsigned char   h_source[ETH_ALEN];
  55         __be16          h_vlan_proto;
  56         __be16          h_vlan_TCI;
  57         __be16          h_vlan_encapsulated_proto;
  58 };
  59
  60 #include <linux/skbuff.h>
  61
  62 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  63 {
  64         return (struct vlan_ethhdr *)skb_mac_header(skb);
  65 }
  66
  67 #define VLAN_PRIO_MASK          0xe000 /* Priority Code Point */
  68 #define VLAN_PRIO_SHIFT         13
  69 #define VLAN_CFI_MASK           0x1000 /* Canonical Format Indicator */
  70 #define VLAN_TAG_PRESENT        VLAN_CFI_MASK
  71 #define VLAN_VID_MASK           0x0fff /* VLAN Identifier */
  72 #define VLAN_N_VID              4096
  73
  74 /* found in socket.c */
  75 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  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_SPLIT_PARTS  8
  82 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_N_VID/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  83
  84 struct vlan_group {
  85         struct net_device       *real_dev; /* The ethernet(like) device
  86                                             * the vlan is attached to.
  87                                             */
  88         unsigned int            nr_vlans;
  89         struct hlist_node       hlist;  /* linked list */
  90         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  91         struct rcu_head         rcu;
  92 };
  93
  94 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  95                                                        u16 vlan_id)
  96 {
  97         struct net_device **array;
  98         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  99         return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
 100 }
 101
 102 static inline void vlan_group_set_device(struct vlan_group *vg,
 103                                          u16 vlan_id,
 104                                          struct net_device *dev)
 105 {
 106         struct net_device **array;
 107         if (!vg)
 108                 return;
 109         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 110         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 111 }
 112
 113 static inline int is_vlan_dev(struct net_device *dev)
 114 {
 115         return dev->priv_flags & IFF_802_1Q_VLAN;
 116 }
 117
 118 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
 119 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
 120
 121 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 122
 123 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
 124                                                u16 vlan_id);
 125 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 126 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 127
 128 extern bool vlan_do_receive(struct sk_buff **skb);
 129 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 130
 131 #else
 132 static inline struct net_device *
 133 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
 134 {
 135         return NULL;
 136 }
 137
 138 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 139 {
 140         BUG();
 141         return NULL;
 142 }
 143
 144 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 145 {
 146         BUG();
 147         return 0;
 148 }
 149
 150 static inline bool vlan_do_receive(struct sk_buff **skb)
 151 {
 152         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 153                 (*skb)->pkt_type = PACKET_OTHERHOST;
 154         return false;
 155 }
 156
 157 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 158 {
 159         return skb;
 160 }
 161 #endif
 162
 163 /**
 164  * vlan_insert_tag - regular VLAN tag inserting
 165  * @skb: skbuff to tag
 166  * @vlan_tci: VLAN TCI to insert
 167  *
 168  * Inserts the VLAN tag into @skb as part of the payload
 169  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 170  *
 171  * Following the skb_unshare() example, in case of error, the calling function
 172  * doesn't have to worry about freeing the original skb.
 173  *
 174  * Does not change skb->protocol so this function can be used during receive.
 175  */
 176 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 177 {
 178         struct vlan_ethhdr *veth;
 179
 180         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 181                 kfree_skb(skb);
 182                 return NULL;
 183         }
 184         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 185
 186         /* Move the mac addresses to the beginning of the new header. */
 187         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 188         skb->mac_header -= VLAN_HLEN;
 189
 190         /* first, the ethernet type */
 191         veth->h_vlan_proto = htons(ETH_P_8021Q);
 192
 193         /* now, the TCI */
 194         veth->h_vlan_TCI = htons(vlan_tci);
 195
 196         return skb;
 197 }
 198
 199 /**
 200  * __vlan_put_tag - regular VLAN tag inserting
 201  * @skb: skbuff to tag
 202  * @vlan_tci: VLAN TCI to insert
 203  *
 204  * Inserts the VLAN tag into @skb as part of the payload
 205  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 206  *
 207  * Following the skb_unshare() example, in case of error, the calling function
 208  * doesn't have to worry about freeing the original skb.
 209  */
 210 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 211 {
 212         skb = vlan_insert_tag(skb, vlan_tci);
 213         if (skb)
 214                 skb->protocol = htons(ETH_P_8021Q);
 215         return skb;
 216 }
 217
 218 /**
 219  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 220  * @skb: skbuff to tag
 221  * @vlan_tci: VLAN TCI to insert
 222  *
 223  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 224  */
 225 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 226                                                      u16 vlan_tci)
 227 {
 228         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 229         return skb;
 230 }
 231
 232 #define HAVE_VLAN_PUT_TAG
 233
 234 /**
 235  * vlan_put_tag - inserts VLAN tag according to device features
 236  * @skb: skbuff to tag
 237  * @vlan_tci: VLAN TCI to insert
 238  *
 239  * Assumes skb->dev is the target that will xmit this frame.
 240  * Returns a VLAN tagged skb.
 241  */
 242 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 243 {
 244         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 245                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 246         } else {
 247                 return __vlan_put_tag(skb, vlan_tci);
 248         }
 249 }
 250
 251 /**
 252  * __vlan_get_tag - get the VLAN ID that is part of the payload
 253  * @skb: skbuff to query
 254  * @vlan_tci: buffer to store vlaue
 255  *
 256  * Returns error if the skb is not of VLAN type
 257  */
 258 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 259 {
 260         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 261
 262         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 263                 return -EINVAL;
 264         }
 265
 266         *vlan_tci = ntohs(veth->h_vlan_TCI);
 267         return 0;
 268 }
 269
 270 /**
 271  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 272  * @skb: skbuff to query
 273  * @vlan_tci: buffer to store vlaue
 274  *
 275  * Returns error if @skb->vlan_tci is not set correctly
 276  */
 277 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 278                                          u16 *vlan_tci)
 279 {
 280         if (vlan_tx_tag_present(skb)) {
 281                 *vlan_tci = vlan_tx_tag_get(skb);
 282                 return 0;
 283         } else {
 284                 *vlan_tci = 0;
 285                 return -EINVAL;
 286         }
 287 }
 288
 289 #define HAVE_VLAN_GET_TAG
 290
 291 /**
 292  * vlan_get_tag - get the VLAN ID from the skb
 293  * @skb: skbuff to query
 294  * @vlan_tci: buffer to store vlaue
 295  *
 296  * Returns error if the skb is not VLAN tagged
 297  */
 298 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 299 {
 300         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 301                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 302         } else {
 303                 return __vlan_get_tag(skb, vlan_tci);
 304         }
 305 }
 306
 307 /**
 308  * vlan_get_protocol - get protocol EtherType.
 309  * @skb: skbuff to query
 310  *
 311  * Returns the EtherType of the packet, regardless of whether it is
 312  * vlan encapsulated (normal or hardware accelerated) or not.
 313  */
 314 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 315 {
 316         __be16 protocol = 0;
 317
 318         if (vlan_tx_tag_present(skb) ||
 319              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 320                 protocol = skb->protocol;
 321         else {
 322                 __be16 proto, *protop;
 323                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 324                                                 h_vlan_encapsulated_proto),
 325                                                 sizeof(proto), &proto);
 326                 if (likely(protop))
 327                         protocol = *protop;
 328         }
 329
 330         return protocol;
 331 }
 332 #endif /* __KERNEL__ */
 333
 334 /* VLAN IOCTLs are found in sockios.h */
 335
 336 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 337 enum vlan_ioctl_cmds {
 338         ADD_VLAN_CMD,
 339         DEL_VLAN_CMD,
 340         SET_VLAN_INGRESS_PRIORITY_CMD,
 341         SET_VLAN_EGRESS_PRIORITY_CMD,
 342         GET_VLAN_INGRESS_PRIORITY_CMD,
 343         GET_VLAN_EGRESS_PRIORITY_CMD,
 344         SET_VLAN_NAME_TYPE_CMD,
 345         SET_VLAN_FLAG_CMD,
 346         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 347         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 348 };
 349
 350 enum vlan_flags {
 351         VLAN_FLAG_REORDER_HDR   = 0x1,
 352         VLAN_FLAG_GVRP          = 0x2,
 353         VLAN_FLAG_LOOSE_BINDING = 0x4,
 354 };
 355
 356 enum vlan_name_types {
 357         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 358         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 359         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 360         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 361         VLAN_NAME_TYPE_HIGHEST
 362 };
 363
 364 struct vlan_ioctl_args {
 365         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 366         char device1[24];
 367
 368         union {
 369                 char device2[24];
 370                 int VID;
 371                 unsigned int skb_priority;
 372                 unsigned int name_type;
 373                 unsigned int bind_type;
 374                 unsigned int flag; /* Matches vlan_dev_info flags */
 375         } u;
 376
 377         short vlan_qos;
 378 };
 379
 380 #endif /* !(_LINUX_IF_VLAN_H_) */