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 extern int vlan_hwaccel_do_receive(struct sk_buff *skb);
 118
 119 #else
 120 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 121 {
 122         BUG();
 123         return NULL;
 124 }
 125
 126 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 127 {
 128         BUG();
 129         return 0;
 130 }
 131
 132 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 133                                     u16 vlan_tci, int polling)
 134 {
 135         BUG();
 136         return NET_XMIT_SUCCESS;
 137 }
 138
 139 static inline int vlan_hwaccel_do_receive(struct sk_buff *skb)
 140 {
 141         return 0;
 142 }
 143 #endif
 144
 145 /**
 146  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 147  * @skb: buffer
 148  * @grp: vlan group
 149  * @vlan_tci: VLAN TCI as received from the card
 150  */
 151 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 152                                   struct vlan_group *grp,
 153                                   u16 vlan_tci)
 154 {
 155         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 156 }
 157
 158 /**
 159  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 160  * @skb: buffer
 161  * @grp: vlan group
 162  * @vlan_tci: VLAN TCI as received from the card
 163  */
 164 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 165                                            struct vlan_group *grp,
 166                                            u16 vlan_tci)
 167 {
 168         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 169 }
 170
 171 /**
 172  * __vlan_put_tag - regular VLAN tag inserting
 173  * @skb: skbuff to tag
 174  * @vlan_tci: VLAN TCI to insert
 175  *
 176  * Inserts the VLAN tag into @skb as part of the payload
 177  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 178  *
 179  * Following the skb_unshare() example, in case of error, the calling function
 180  * doesn't have to worry about freeing the original skb.
 181  */
 182 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 183 {
 184         struct vlan_ethhdr *veth;
 185
 186         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 187                 kfree_skb(skb);
 188                 return NULL;
 189         }
 190         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 191
 192         /* Move the mac addresses to the beginning of the new header. */
 193         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 194
 195         /* first, the ethernet type */
 196         veth->h_vlan_proto = htons(ETH_P_8021Q);
 197
 198         /* now, the TCI */
 199         veth->h_vlan_TCI = htons(vlan_tci);
 200
 201         skb->protocol = htons(ETH_P_8021Q);
 202
 203         return skb;
 204 }
 205
 206 /**
 207  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 208  * @skb: skbuff to tag
 209  * @vlan_tci: VLAN TCI to insert
 210  *
 211  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 212  */
 213 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 214                                                      u16 vlan_tci)
 215 {
 216         skb->vlan_tci = vlan_tci;
 217         return skb;
 218 }
 219
 220 #define HAVE_VLAN_PUT_TAG
 221
 222 /**
 223  * vlan_put_tag - inserts VLAN tag according to device features
 224  * @skb: skbuff to tag
 225  * @vlan_tci: VLAN TCI to insert
 226  *
 227  * Assumes skb->dev is the target that will xmit this frame.
 228  * Returns a VLAN tagged skb.
 229  */
 230 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 231 {
 232         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 233                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 234         } else {
 235                 return __vlan_put_tag(skb, vlan_tci);
 236         }
 237 }
 238
 239 /**
 240  * __vlan_get_tag - get the VLAN ID that is part of the payload
 241  * @skb: skbuff to query
 242  * @vlan_tci: buffer to store vlaue
 243  *
 244  * Returns error if the skb is not of VLAN type
 245  */
 246 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 247 {
 248         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 249
 250         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 251                 return -EINVAL;
 252         }
 253
 254         *vlan_tci = ntohs(veth->h_vlan_TCI);
 255         return 0;
 256 }
 257
 258 /**
 259  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 260  * @skb: skbuff to query
 261  * @vlan_tci: buffer to store vlaue
 262  *
 263  * Returns error if @skb->vlan_tci is not set correctly
 264  */
 265 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 266                                          u16 *vlan_tci)
 267 {
 268         if (vlan_tx_tag_present(skb)) {
 269                 *vlan_tci = skb->vlan_tci;
 270                 return 0;
 271         } else {
 272                 *vlan_tci = 0;
 273                 return -EINVAL;
 274         }
 275 }
 276
 277 #define HAVE_VLAN_GET_TAG
 278
 279 /**
 280  * vlan_get_tag - get the VLAN ID from the skb
 281  * @skb: skbuff to query
 282  * @vlan_tci: buffer to store vlaue
 283  *
 284  * Returns error if the skb is not VLAN tagged
 285  */
 286 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 287 {
 288         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 289                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 290         } else {
 291                 return __vlan_get_tag(skb, vlan_tci);
 292         }
 293 }
 294
 295 #endif /* __KERNEL__ */
 296
 297 /* VLAN IOCTLs are found in sockios.h */
 298
 299 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 300 enum vlan_ioctl_cmds {
 301         ADD_VLAN_CMD,
 302         DEL_VLAN_CMD,
 303         SET_VLAN_INGRESS_PRIORITY_CMD,
 304         SET_VLAN_EGRESS_PRIORITY_CMD,
 305         GET_VLAN_INGRESS_PRIORITY_CMD,
 306         GET_VLAN_EGRESS_PRIORITY_CMD,
 307         SET_VLAN_NAME_TYPE_CMD,
 308         SET_VLAN_FLAG_CMD,
 309         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 310         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 311 };
 312
 313 enum vlan_flags {
 314         VLAN_FLAG_REORDER_HDR   = 0x1,
 315         VLAN_FLAG_GVRP          = 0x2,
 316 };
 317
 318 enum vlan_name_types {
 319         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 320         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 321         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 322         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 323         VLAN_NAME_TYPE_HIGHEST
 324 };
 325
 326 struct vlan_ioctl_args {
 327         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 328         char device1[24];
 329
 330         union {
 331                 char device2[24];
 332                 int VID;
 333                 unsigned int skb_priority;
 334                 unsigned int name_type;
 335                 unsigned int bind_type;
 336                 unsigned int flag; /* Matches vlan_dev_info flags */
 337         } u;
 338
 339         short vlan_qos;
 340 };
 341
 342 #endif /* !(_LINUX_IF_VLAN_H_) */