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 /* Must be invoked with rcu_read_lock or with RTNL. */
 123 static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
 124                                                u16 vlan_id)
 125 {
 126         struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);
 127
 128         if (grp)
 129                 return vlan_group_get_device(grp, vlan_id);
 130
 131         return NULL;
 132 }
 133
 134 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 135 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 136
 137 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 138                              u16 vlan_tci, int polling);
 139 extern bool vlan_do_receive(struct sk_buff **skb);
 140 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 141 extern gro_result_t
 142 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 143                  unsigned int vlan_tci, struct sk_buff *skb);
 144 extern gro_result_t
 145 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 146                unsigned int vlan_tci);
 147
 148 #else
 149 static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
 150                                                u16 vlan_id)
 151 {
 152         return NULL;
 153 }
 154
 155 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 156 {
 157         BUG();
 158         return NULL;
 159 }
 160
 161 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 162 {
 163         BUG();
 164         return 0;
 165 }
 166
 167 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 168                                     u16 vlan_tci, int polling)
 169 {
 170         BUG();
 171         return NET_XMIT_SUCCESS;
 172 }
 173
 174 static inline bool vlan_do_receive(struct sk_buff **skb)
 175 {
 176         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 177                 (*skb)->pkt_type = PACKET_OTHERHOST;
 178         return false;
 179 }
 180
 181 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 182 {
 183         return skb;
 184 }
 185
 186 static inline gro_result_t
 187 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 188                  unsigned int vlan_tci, struct sk_buff *skb)
 189 {
 190         return GRO_DROP;
 191 }
 192
 193 static inline gro_result_t
 194 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 195                unsigned int vlan_tci)
 196 {
 197         return GRO_DROP;
 198 }
 199 #endif
 200
 201 /**
 202  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 203  * @skb: buffer
 204  * @grp: vlan group
 205  * @vlan_tci: VLAN TCI as received from the card
 206  */
 207 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 208                                   struct vlan_group *grp,
 209                                   u16 vlan_tci)
 210 {
 211         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 212 }
 213
 214 /**
 215  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 216  * @skb: buffer
 217  * @grp: vlan group
 218  * @vlan_tci: VLAN TCI as received from the card
 219  */
 220 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 221                                            struct vlan_group *grp,
 222                                            u16 vlan_tci)
 223 {
 224         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 225 }
 226
 227 /**
 228  * __vlan_put_tag - regular VLAN tag inserting
 229  * @skb: skbuff to tag
 230  * @vlan_tci: VLAN TCI to insert
 231  *
 232  * Inserts the VLAN tag into @skb as part of the payload
 233  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 234  *
 235  * Following the skb_unshare() example, in case of error, the calling function
 236  * doesn't have to worry about freeing the original skb.
 237  */
 238 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 239 {
 240         struct vlan_ethhdr *veth;
 241
 242         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 243                 kfree_skb(skb);
 244                 return NULL;
 245         }
 246         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 247
 248         /* Move the mac addresses to the beginning of the new header. */
 249         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 250         skb->mac_header -= VLAN_HLEN;
 251
 252         /* first, the ethernet type */
 253         veth->h_vlan_proto = htons(ETH_P_8021Q);
 254
 255         /* now, the TCI */
 256         veth->h_vlan_TCI = htons(vlan_tci);
 257
 258         skb->protocol = htons(ETH_P_8021Q);
 259
 260         return skb;
 261 }
 262
 263 /**
 264  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 265  * @skb: skbuff to tag
 266  * @vlan_tci: VLAN TCI to insert
 267  *
 268  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 269  */
 270 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 271                                                      u16 vlan_tci)
 272 {
 273         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 274         return skb;
 275 }
 276
 277 #define HAVE_VLAN_PUT_TAG
 278
 279 /**
 280  * vlan_put_tag - inserts VLAN tag according to device features
 281  * @skb: skbuff to tag
 282  * @vlan_tci: VLAN TCI to insert
 283  *
 284  * Assumes skb->dev is the target that will xmit this frame.
 285  * Returns a VLAN tagged skb.
 286  */
 287 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 288 {
 289         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 290                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 291         } else {
 292                 return __vlan_put_tag(skb, vlan_tci);
 293         }
 294 }
 295
 296 /**
 297  * __vlan_get_tag - get the VLAN ID that is part of the payload
 298  * @skb: skbuff to query
 299  * @vlan_tci: buffer to store vlaue
 300  *
 301  * Returns error if the skb is not of VLAN type
 302  */
 303 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 304 {
 305         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 306
 307         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 308                 return -EINVAL;
 309         }
 310
 311         *vlan_tci = ntohs(veth->h_vlan_TCI);
 312         return 0;
 313 }
 314
 315 /**
 316  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 317  * @skb: skbuff to query
 318  * @vlan_tci: buffer to store vlaue
 319  *
 320  * Returns error if @skb->vlan_tci is not set correctly
 321  */
 322 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 323                                          u16 *vlan_tci)
 324 {
 325         if (vlan_tx_tag_present(skb)) {
 326                 *vlan_tci = vlan_tx_tag_get(skb);
 327                 return 0;
 328         } else {
 329                 *vlan_tci = 0;
 330                 return -EINVAL;
 331         }
 332 }
 333
 334 #define HAVE_VLAN_GET_TAG
 335
 336 /**
 337  * vlan_get_tag - get the VLAN ID from the skb
 338  * @skb: skbuff to query
 339  * @vlan_tci: buffer to store vlaue
 340  *
 341  * Returns error if the skb is not VLAN tagged
 342  */
 343 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 344 {
 345         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 346                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 347         } else {
 348                 return __vlan_get_tag(skb, vlan_tci);
 349         }
 350 }
 351
 352 /**
 353  * vlan_get_protocol - get protocol EtherType.
 354  * @skb: skbuff to query
 355  *
 356  * Returns the EtherType of the packet, regardless of whether it is
 357  * vlan encapsulated (normal or hardware accelerated) or not.
 358  */
 359 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 360 {
 361         __be16 protocol = 0;
 362
 363         if (vlan_tx_tag_present(skb) ||
 364              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 365                 protocol = skb->protocol;
 366         else {
 367                 __be16 proto, *protop;
 368                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 369                                                 h_vlan_encapsulated_proto),
 370                                                 sizeof(proto), &proto);
 371                 if (likely(protop))
 372                         protocol = *protop;
 373         }
 374
 375         return protocol;
 376 }
 377 #endif /* __KERNEL__ */
 378
 379 /* VLAN IOCTLs are found in sockios.h */
 380
 381 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 382 enum vlan_ioctl_cmds {
 383         ADD_VLAN_CMD,
 384         DEL_VLAN_CMD,
 385         SET_VLAN_INGRESS_PRIORITY_CMD,
 386         SET_VLAN_EGRESS_PRIORITY_CMD,
 387         GET_VLAN_INGRESS_PRIORITY_CMD,
 388         GET_VLAN_EGRESS_PRIORITY_CMD,
 389         SET_VLAN_NAME_TYPE_CMD,
 390         SET_VLAN_FLAG_CMD,
 391         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 392         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 393 };
 394
 395 enum vlan_flags {
 396         VLAN_FLAG_REORDER_HDR   = 0x1,
 397         VLAN_FLAG_GVRP          = 0x2,
 398         VLAN_FLAG_LOOSE_BINDING = 0x4,
 399 };
 400
 401 enum vlan_name_types {
 402         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 403         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 404         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 405         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 406         VLAN_NAME_TYPE_HIGHEST
 407 };
 408
 409 struct vlan_ioctl_args {
 410         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 411         char device1[24];
 412
 413         union {
 414                 char device2[24];
 415                 int VID;
 416                 unsigned int skb_priority;
 417                 unsigned int name_type;
 418                 unsigned int bind_type;
 419                 unsigned int flag; /* Matches vlan_dev_info flags */
 420         } u;
 421
 422         short vlan_qos;
 423 };
 424
 425 #endif /* !(_LINUX_IF_VLAN_H_) */