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 extern int vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 119                             unsigned int vlan_tci, struct sk_buff *skb);
 120 extern int vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 121                           unsigned int vlan_tci,
 122                           struct napi_gro_fraginfo *info);
 123
 124 #else
 125 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 126 {
 127         BUG();
 128         return NULL;
 129 }
 130
 131 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 132 {
 133         BUG();
 134         return 0;
 135 }
 136
 137 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 138                                     u16 vlan_tci, int polling)
 139 {
 140         BUG();
 141         return NET_XMIT_SUCCESS;
 142 }
 143
 144 static inline int vlan_hwaccel_do_receive(struct sk_buff *skb)
 145 {
 146         return 0;
 147 }
 148
 149 static inline int vlan_gro_receive(struct napi_struct *napi,
 150                                    struct vlan_group *grp,
 151                                    unsigned int vlan_tci, struct sk_buff *skb)
 152 {
 153         return NET_RX_DROP;
 154 }
 155
 156 static inline int vlan_gro_frags(struct napi_struct *napi,
 157                                  struct vlan_group *grp, unsigned int vlan_tci,
 158                                  struct napi_gro_fraginfo *info)
 159 {
 160         return NET_RX_DROP;
 161 }
 162 #endif
 163
 164 /**
 165  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 166  * @skb: buffer
 167  * @grp: vlan group
 168  * @vlan_tci: VLAN TCI as received from the card
 169  */
 170 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 171                                   struct vlan_group *grp,
 172                                   u16 vlan_tci)
 173 {
 174         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 175 }
 176
 177 /**
 178  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 179  * @skb: buffer
 180  * @grp: vlan group
 181  * @vlan_tci: VLAN TCI as received from the card
 182  */
 183 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 184                                            struct vlan_group *grp,
 185                                            u16 vlan_tci)
 186 {
 187         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 188 }
 189
 190 /**
 191  * __vlan_put_tag - regular VLAN tag inserting
 192  * @skb: skbuff to tag
 193  * @vlan_tci: VLAN TCI to insert
 194  *
 195  * Inserts the VLAN tag into @skb as part of the payload
 196  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 197  *
 198  * Following the skb_unshare() example, in case of error, the calling function
 199  * doesn't have to worry about freeing the original skb.
 200  */
 201 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 202 {
 203         struct vlan_ethhdr *veth;
 204
 205         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 206                 kfree_skb(skb);
 207                 return NULL;
 208         }
 209         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 210
 211         /* Move the mac addresses to the beginning of the new header. */
 212         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 213
 214         /* first, the ethernet type */
 215         veth->h_vlan_proto = htons(ETH_P_8021Q);
 216
 217         /* now, the TCI */
 218         veth->h_vlan_TCI = htons(vlan_tci);
 219
 220         skb->protocol = htons(ETH_P_8021Q);
 221
 222         return skb;
 223 }
 224
 225 /**
 226  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 227  * @skb: skbuff to tag
 228  * @vlan_tci: VLAN TCI to insert
 229  *
 230  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 231  */
 232 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 233                                                      u16 vlan_tci)
 234 {
 235         skb->vlan_tci = vlan_tci;
 236         return skb;
 237 }
 238
 239 #define HAVE_VLAN_PUT_TAG
 240
 241 /**
 242  * vlan_put_tag - inserts VLAN tag according to device features
 243  * @skb: skbuff to tag
 244  * @vlan_tci: VLAN TCI to insert
 245  *
 246  * Assumes skb->dev is the target that will xmit this frame.
 247  * Returns a VLAN tagged skb.
 248  */
 249 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 250 {
 251         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 252                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 253         } else {
 254                 return __vlan_put_tag(skb, vlan_tci);
 255         }
 256 }
 257
 258 /**
 259  * __vlan_get_tag - get the VLAN ID that is part of the payload
 260  * @skb: skbuff to query
 261  * @vlan_tci: buffer to store vlaue
 262  *
 263  * Returns error if the skb is not of VLAN type
 264  */
 265 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 266 {
 267         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 268
 269         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 270                 return -EINVAL;
 271         }
 272
 273         *vlan_tci = ntohs(veth->h_vlan_TCI);
 274         return 0;
 275 }
 276
 277 /**
 278  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 279  * @skb: skbuff to query
 280  * @vlan_tci: buffer to store vlaue
 281  *
 282  * Returns error if @skb->vlan_tci is not set correctly
 283  */
 284 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 285                                          u16 *vlan_tci)
 286 {
 287         if (vlan_tx_tag_present(skb)) {
 288                 *vlan_tci = skb->vlan_tci;
 289                 return 0;
 290         } else {
 291                 *vlan_tci = 0;
 292                 return -EINVAL;
 293         }
 294 }
 295
 296 #define HAVE_VLAN_GET_TAG
 297
 298 /**
 299  * vlan_get_tag - get the VLAN ID from the skb
 300  * @skb: skbuff to query
 301  * @vlan_tci: buffer to store vlaue
 302  *
 303  * Returns error if the skb is not VLAN tagged
 304  */
 305 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 306 {
 307         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 308                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 309         } else {
 310                 return __vlan_get_tag(skb, vlan_tci);
 311         }
 312 }
 313
 314 #endif /* __KERNEL__ */
 315
 316 /* VLAN IOCTLs are found in sockios.h */
 317
 318 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 319 enum vlan_ioctl_cmds {
 320         ADD_VLAN_CMD,
 321         DEL_VLAN_CMD,
 322         SET_VLAN_INGRESS_PRIORITY_CMD,
 323         SET_VLAN_EGRESS_PRIORITY_CMD,
 324         GET_VLAN_INGRESS_PRIORITY_CMD,
 325         GET_VLAN_EGRESS_PRIORITY_CMD,
 326         SET_VLAN_NAME_TYPE_CMD,
 327         SET_VLAN_FLAG_CMD,
 328         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 329         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 330 };
 331
 332 enum vlan_flags {
 333         VLAN_FLAG_REORDER_HDR   = 0x1,
 334         VLAN_FLAG_GVRP          = 0x2,
 335 };
 336
 337 enum vlan_name_types {
 338         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 339         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 340         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 341         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 342         VLAN_NAME_TYPE_HIGHEST
 343 };
 344
 345 struct vlan_ioctl_args {
 346         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 347         char device1[24];
 348
 349         union {
 350                 char device2[24];
 351                 int VID;
 352                 unsigned int skb_priority;
 353                 unsigned int name_type;
 354                 unsigned int bind_type;
 355                 unsigned int flag; /* Matches vlan_dev_info flags */
 356         } u;
 357
 358         short vlan_qos;
 359 };
 360
 361 #endif /* !(_LINUX_IF_VLAN_H_) */