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                                                        u16 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                                          u16 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 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci)
 109 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci)
 110
 111 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 112 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 113 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 114
 115 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 116                              u16 vlan_tci, int polling);
 117 #else
 118 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 119 {
 120         BUG();
 121         return NULL;
 122 }
 123
 124 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 125 {
 126         BUG();
 127         return 0;
 128 }
 129
 130 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 131                                     u16 vlan_tci, int polling)
 132 {
 133         BUG();
 134         return NET_XMIT_SUCCESS;
 135 }
 136 #endif
 137
 138 /**
 139  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 140  * @skb: buffer
 141  * @grp: vlan group
 142  * @vlan_tci: VLAN TCI as received from the card
 143  */
 144 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 145                                   struct vlan_group *grp,
 146                                   u16 vlan_tci)
 147 {
 148         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 149 }
 150
 151 /**
 152  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 153  * @skb: buffer
 154  * @grp: vlan group
 155  * @vlan_tci: VLAN TCI as received from the card
 156  */
 157 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 158                                            struct vlan_group *grp,
 159                                            u16 vlan_tci)
 160 {
 161         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 162 }
 163
 164 /**
 165  * __vlan_put_tag - regular VLAN tag inserting
 166  * @skb: skbuff to tag
 167  * @vlan_tci: VLAN TCI to insert
 168  *
 169  * Inserts the VLAN tag into @skb as part of the payload
 170  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 171  *
 172  * Following the skb_unshare() example, in case of error, the calling function
 173  * doesn't have to worry about freeing the original skb.
 174  */
 175 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 176 {
 177         struct vlan_ethhdr *veth;
 178
 179         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 180                 kfree_skb(skb);
 181                 return NULL;
 182         }
 183         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 184
 185         /* Move the mac addresses to the beginning of the new header. */
 186         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 187
 188         /* first, the ethernet type */
 189         veth->h_vlan_proto = htons(ETH_P_8021Q);
 190
 191         /* now, the TCI */
 192         veth->h_vlan_TCI = htons(vlan_tci);
 193
 194         skb->protocol = htons(ETH_P_8021Q);
 195
 196         return skb;
 197 }
 198
 199 /**
 200  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 201  * @skb: skbuff to tag
 202  * @vlan_tci: VLAN TCI to insert
 203  *
 204  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 205  */
 206 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 207                                                      u16 vlan_tci)
 208 {
 209         skb->vlan_tci = vlan_tci;
 210         return skb;
 211 }
 212
 213 #define HAVE_VLAN_PUT_TAG
 214
 215 /**
 216  * vlan_put_tag - inserts VLAN tag according to device features
 217  * @skb: skbuff to tag
 218  * @vlan_tci: VLAN TCI to insert
 219  *
 220  * Assumes skb->dev is the target that will xmit this frame.
 221  * Returns a VLAN tagged skb.
 222  */
 223 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 224 {
 225         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 226                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 227         } else {
 228                 return __vlan_put_tag(skb, vlan_tci);
 229         }
 230 }
 231
 232 /**
 233  * __vlan_get_tag - get the VLAN ID that is part of the payload
 234  * @skb: skbuff to query
 235  * @vlan_tci: buffer to store vlaue
 236  *
 237  * Returns error if the skb is not of VLAN type
 238  */
 239 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 240 {
 241         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 242
 243         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 244                 return -EINVAL;
 245         }
 246
 247         *vlan_tci = ntohs(veth->h_vlan_TCI);
 248         return 0;
 249 }
 250
 251 /**
 252  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 253  * @skb: skbuff to query
 254  * @vlan_tci: buffer to store vlaue
 255  *
 256  * Returns error if @skb->vlan_tci is not set correctly
 257  */
 258 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 259                                          u16 *vlan_tci)
 260 {
 261         if (vlan_tx_tag_present(skb)) {
 262                 *vlan_tci = skb->vlan_tci;
 263                 return 0;
 264         } else {
 265                 *vlan_tci = 0;
 266                 return -EINVAL;
 267         }
 268 }
 269
 270 #define HAVE_VLAN_GET_TAG
 271
 272 /**
 273  * vlan_get_tag - get the VLAN ID from the skb
 274  * @skb: skbuff to query
 275  * @vlan_tci: buffer to store vlaue
 276  *
 277  * Returns error if the skb is not VLAN tagged
 278  */
 279 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 280 {
 281         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 282                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 283         } else {
 284                 return __vlan_get_tag(skb, vlan_tci);
 285         }
 286 }
 287
 288 #endif /* __KERNEL__ */
 289
 290 /* VLAN IOCTLs are found in sockios.h */
 291
 292 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 293 enum vlan_ioctl_cmds {
 294         ADD_VLAN_CMD,
 295         DEL_VLAN_CMD,
 296         SET_VLAN_INGRESS_PRIORITY_CMD,
 297         SET_VLAN_EGRESS_PRIORITY_CMD,
 298         GET_VLAN_INGRESS_PRIORITY_CMD,
 299         GET_VLAN_EGRESS_PRIORITY_CMD,
 300         SET_VLAN_NAME_TYPE_CMD,
 301         SET_VLAN_FLAG_CMD,
 302         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 303         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 304 };
 305
 306 enum vlan_flags {
 307         VLAN_FLAG_REORDER_HDR   = 0x1,
 308         VLAN_FLAG_GVRP          = 0x2,
 309 };
 310
 311 enum vlan_name_types {
 312         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 313         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 314         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 315         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 316         VLAN_NAME_TYPE_HIGHEST
 317 };
 318
 319 struct vlan_ioctl_args {
 320         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 321         char device1[24];
 322
 323         union {
 324                 char device2[24];
 325                 int VID;
 326                 unsigned int skb_priority;
 327                 unsigned int name_type;
 328                 unsigned int bind_type;
 329                 unsigned int flag; /* Matches vlan_dev_info flags */
 330         } u;
 331
 332         short vlan_qos;
 333 };
 334
 335 #endif /* !(_LINUX_IF_VLAN_H_) */