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 int is_vlan_dev(struct net_device *dev)
  95 {
  96         return dev->priv_flags & IFF_802_1Q_VLAN;
  97 }
  98
  99 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
 100 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
 101
 102 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 103
 104 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
 105                                                u16 vlan_id);
 106 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 107 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 108
 109 extern bool vlan_do_receive(struct sk_buff **skb);
 110 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 111
 112 #else
 113 static inline struct net_device *
 114 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
 115 {
 116         return NULL;
 117 }
 118
 119 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 120 {
 121         BUG();
 122         return NULL;
 123 }
 124
 125 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 126 {
 127         BUG();
 128         return 0;
 129 }
 130
 131 static inline bool vlan_do_receive(struct sk_buff **skb)
 132 {
 133         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 134                 (*skb)->pkt_type = PACKET_OTHERHOST;
 135         return false;
 136 }
 137
 138 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 139 {
 140         return skb;
 141 }
 142 #endif
 143
 144 /**
 145  * vlan_insert_tag - regular VLAN tag inserting
 146  * @skb: skbuff to tag
 147  * @vlan_tci: VLAN TCI to insert
 148  *
 149  * Inserts the VLAN tag into @skb as part of the payload
 150  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 151  *
 152  * Following the skb_unshare() example, in case of error, the calling function
 153  * doesn't have to worry about freeing the original skb.
 154  *
 155  * Does not change skb->protocol so this function can be used during receive.
 156  */
 157 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 158 {
 159         struct vlan_ethhdr *veth;
 160
 161         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 162                 kfree_skb(skb);
 163                 return NULL;
 164         }
 165         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 166
 167         /* Move the mac addresses to the beginning of the new header. */
 168         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 169         skb->mac_header -= VLAN_HLEN;
 170
 171         /* first, the ethernet type */
 172         veth->h_vlan_proto = htons(ETH_P_8021Q);
 173
 174         /* now, the TCI */
 175         veth->h_vlan_TCI = htons(vlan_tci);
 176
 177         return skb;
 178 }
 179
 180 /**
 181  * __vlan_put_tag - regular VLAN tag inserting
 182  * @skb: skbuff to tag
 183  * @vlan_tci: VLAN TCI to insert
 184  *
 185  * Inserts the VLAN tag into @skb as part of the payload
 186  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 187  *
 188  * Following the skb_unshare() example, in case of error, the calling function
 189  * doesn't have to worry about freeing the original skb.
 190  */
 191 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 192 {
 193         skb = vlan_insert_tag(skb, vlan_tci);
 194         if (skb)
 195                 skb->protocol = htons(ETH_P_8021Q);
 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_TAG_PRESENT | 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 = vlan_tx_tag_get(skb);
 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 /**
 289  * vlan_get_protocol - get protocol EtherType.
 290  * @skb: skbuff to query
 291  *
 292  * Returns the EtherType of the packet, regardless of whether it is
 293  * vlan encapsulated (normal or hardware accelerated) or not.
 294  */
 295 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 296 {
 297         __be16 protocol = 0;
 298
 299         if (vlan_tx_tag_present(skb) ||
 300              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 301                 protocol = skb->protocol;
 302         else {
 303                 __be16 proto, *protop;
 304                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 305                                                 h_vlan_encapsulated_proto),
 306                                                 sizeof(proto), &proto);
 307                 if (likely(protop))
 308                         protocol = *protop;
 309         }
 310
 311         return protocol;
 312 }
 313 #endif /* __KERNEL__ */
 314
 315 /* VLAN IOCTLs are found in sockios.h */
 316
 317 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 318 enum vlan_ioctl_cmds {
 319         ADD_VLAN_CMD,
 320         DEL_VLAN_CMD,
 321         SET_VLAN_INGRESS_PRIORITY_CMD,
 322         SET_VLAN_EGRESS_PRIORITY_CMD,
 323         GET_VLAN_INGRESS_PRIORITY_CMD,
 324         GET_VLAN_EGRESS_PRIORITY_CMD,
 325         SET_VLAN_NAME_TYPE_CMD,
 326         SET_VLAN_FLAG_CMD,
 327         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 328         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 329 };
 330
 331 enum vlan_flags {
 332         VLAN_FLAG_REORDER_HDR   = 0x1,
 333         VLAN_FLAG_GVRP          = 0x2,
 334         VLAN_FLAG_LOOSE_BINDING = 0x4,
 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_) */