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_dev_real_dev(const struct net_device *dev);
 124 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 125
 126 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 127                              u16 vlan_tci, int polling);
 128 extern bool vlan_do_receive(struct sk_buff **skb);
 129 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 130 extern gro_result_t
 131 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 132                  unsigned int vlan_tci, struct sk_buff *skb);
 133 extern gro_result_t
 134 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 135                unsigned int vlan_tci);
 136
 137 #else
 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 int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 151                                     u16 vlan_tci, int polling)
 152 {
 153         BUG();
 154         return NET_XMIT_SUCCESS;
 155 }
 156
 157 static inline bool vlan_do_receive(struct sk_buff **skb)
 158 {
 159         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 160                 (*skb)->pkt_type = PACKET_OTHERHOST;
 161         return false;
 162 }
 163
 164 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 165 {
 166         return skb;
 167 }
 168
 169 static inline gro_result_t
 170 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 171                  unsigned int vlan_tci, struct sk_buff *skb)
 172 {
 173         return GRO_DROP;
 174 }
 175
 176 static inline gro_result_t
 177 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 178                unsigned int vlan_tci)
 179 {
 180         return GRO_DROP;
 181 }
 182 #endif
 183
 184 /**
 185  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 186  * @skb: buffer
 187  * @grp: vlan group
 188  * @vlan_tci: VLAN TCI as received from the card
 189  */
 190 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 191                                   struct vlan_group *grp,
 192                                   u16 vlan_tci)
 193 {
 194         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 195 }
 196
 197 /**
 198  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 199  * @skb: buffer
 200  * @grp: vlan group
 201  * @vlan_tci: VLAN TCI as received from the card
 202  */
 203 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 204                                            struct vlan_group *grp,
 205                                            u16 vlan_tci)
 206 {
 207         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 208 }
 209
 210 /**
 211  * vlan_insert_tag - regular VLAN tag inserting
 212  * @skb: skbuff to tag
 213  * @vlan_tci: VLAN TCI to insert
 214  *
 215  * Inserts the VLAN tag into @skb as part of the payload
 216  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 217  *
 218  * Following the skb_unshare() example, in case of error, the calling function
 219  * doesn't have to worry about freeing the original skb.
 220  *
 221  * Does not change skb->protocol so this function can be used during receive.
 222  */
 223 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 224 {
 225         struct vlan_ethhdr *veth;
 226
 227         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 228                 kfree_skb(skb);
 229                 return NULL;
 230         }
 231         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 232
 233         /* Move the mac addresses to the beginning of the new header. */
 234         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 235         skb->mac_header -= VLAN_HLEN;
 236
 237         /* first, the ethernet type */
 238         veth->h_vlan_proto = htons(ETH_P_8021Q);
 239
 240         /* now, the TCI */
 241         veth->h_vlan_TCI = htons(vlan_tci);
 242
 243         return skb;
 244 }
 245
 246 /**
 247  * __vlan_put_tag - regular VLAN tag inserting
 248  * @skb: skbuff to tag
 249  * @vlan_tci: VLAN TCI to insert
 250  *
 251  * Inserts the VLAN tag into @skb as part of the payload
 252  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 253  *
 254  * Following the skb_unshare() example, in case of error, the calling function
 255  * doesn't have to worry about freeing the original skb.
 256  */
 257 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 258 {
 259         skb = vlan_insert_tag(skb, vlan_tci);
 260         if (skb)
 261                 skb->protocol = htons(ETH_P_8021Q);
 262         return skb;
 263 }
 264
 265 /**
 266  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 267  * @skb: skbuff to tag
 268  * @vlan_tci: VLAN TCI to insert
 269  *
 270  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 271  */
 272 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 273                                                      u16 vlan_tci)
 274 {
 275         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 276         return skb;
 277 }
 278
 279 #define HAVE_VLAN_PUT_TAG
 280
 281 /**
 282  * vlan_put_tag - inserts VLAN tag according to device features
 283  * @skb: skbuff to tag
 284  * @vlan_tci: VLAN TCI to insert
 285  *
 286  * Assumes skb->dev is the target that will xmit this frame.
 287  * Returns a VLAN tagged skb.
 288  */
 289 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 290 {
 291         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 292                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 293         } else {
 294                 return __vlan_put_tag(skb, vlan_tci);
 295         }
 296 }
 297
 298 /**
 299  * __vlan_get_tag - get the VLAN ID that is part of the payload
 300  * @skb: skbuff to query
 301  * @vlan_tci: buffer to store vlaue
 302  *
 303  * Returns error if the skb is not of VLAN type
 304  */
 305 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 306 {
 307         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 308
 309         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 310                 return -EINVAL;
 311         }
 312
 313         *vlan_tci = ntohs(veth->h_vlan_TCI);
 314         return 0;
 315 }
 316
 317 /**
 318  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 319  * @skb: skbuff to query
 320  * @vlan_tci: buffer to store vlaue
 321  *
 322  * Returns error if @skb->vlan_tci is not set correctly
 323  */
 324 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 325                                          u16 *vlan_tci)
 326 {
 327         if (vlan_tx_tag_present(skb)) {
 328                 *vlan_tci = vlan_tx_tag_get(skb);
 329                 return 0;
 330         } else {
 331                 *vlan_tci = 0;
 332                 return -EINVAL;
 333         }
 334 }
 335
 336 #define HAVE_VLAN_GET_TAG
 337
 338 /**
 339  * vlan_get_tag - get the VLAN ID from the skb
 340  * @skb: skbuff to query
 341  * @vlan_tci: buffer to store vlaue
 342  *
 343  * Returns error if the skb is not VLAN tagged
 344  */
 345 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 346 {
 347         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 348                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 349         } else {
 350                 return __vlan_get_tag(skb, vlan_tci);
 351         }
 352 }
 353
 354 /**
 355  * vlan_get_protocol - get protocol EtherType.
 356  * @skb: skbuff to query
 357  *
 358  * Returns the EtherType of the packet, regardless of whether it is
 359  * vlan encapsulated (normal or hardware accelerated) or not.
 360  */
 361 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 362 {
 363         __be16 protocol = 0;
 364
 365         if (vlan_tx_tag_present(skb) ||
 366              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 367                 protocol = skb->protocol;
 368         else {
 369                 __be16 proto, *protop;
 370                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 371                                                 h_vlan_encapsulated_proto),
 372                                                 sizeof(proto), &proto);
 373                 if (likely(protop))
 374                         protocol = *protop;
 375         }
 376
 377         return protocol;
 378 }
 379 #endif /* __KERNEL__ */
 380
 381 /* VLAN IOCTLs are found in sockios.h */
 382
 383 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 384 enum vlan_ioctl_cmds {
 385         ADD_VLAN_CMD,
 386         DEL_VLAN_CMD,
 387         SET_VLAN_INGRESS_PRIORITY_CMD,
 388         SET_VLAN_EGRESS_PRIORITY_CMD,
 389         GET_VLAN_INGRESS_PRIORITY_CMD,
 390         GET_VLAN_EGRESS_PRIORITY_CMD,
 391         SET_VLAN_NAME_TYPE_CMD,
 392         SET_VLAN_FLAG_CMD,
 393         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 394         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 395 };
 396
 397 enum vlan_flags {
 398         VLAN_FLAG_REORDER_HDR   = 0x1,
 399         VLAN_FLAG_GVRP          = 0x2,
 400         VLAN_FLAG_LOOSE_BINDING = 0x4,
 401 };
 402
 403 enum vlan_name_types {
 404         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 405         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 406         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 407         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 408         VLAN_NAME_TYPE_HIGHEST
 409 };
 410
 411 struct vlan_ioctl_args {
 412         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 413         char device1[24];
 414
 415         union {
 416                 char device2[24];
 417                 int VID;
 418                 unsigned int skb_priority;
 419                 unsigned int name_type;
 420                 unsigned int bind_type;
 421                 unsigned int flag; /* Matches vlan_dev_info flags */
 422         } u;
 423
 424         short vlan_qos;
 425 };
 426
 427 #endif /* !(_LINUX_IF_VLAN_H_) */