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 struct vlan_info;
  78
  79 static inline int is_vlan_dev(struct net_device *dev)
  80 {
  81         return dev->priv_flags & IFF_802_1Q_VLAN;
  82 }
  83
  84 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  85 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  86
  87 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  88
  89 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  90                                                u16 vlan_id);
  91 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  92 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  93
  94 extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler);
  95 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
  96
  97 extern int vlan_vid_add(struct net_device *dev, unsigned short vid);
  98 extern void vlan_vid_del(struct net_device *dev, unsigned short vid);
  99
 100 extern int vlan_vids_add_by_dev(struct net_device *dev,
 101                                 const struct net_device *by_dev);
 102 extern void vlan_vids_del_by_dev(struct net_device *dev,
 103                                  const struct net_device *by_dev);
 104 #else
 105 static inline struct net_device *
 106 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
 107 {
 108         return NULL;
 109 }
 110
 111 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 112 {
 113         BUG();
 114         return NULL;
 115 }
 116
 117 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 118 {
 119         BUG();
 120         return 0;
 121 }
 122
 123 static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler)
 124 {
 125         if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler)
 126                 (*skb)->pkt_type = PACKET_OTHERHOST;
 127         return false;
 128 }
 129
 130 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 131 {
 132         return skb;
 133 }
 134
 135 static inline int vlan_vid_add(struct net_device *dev, unsigned short vid)
 136 {
 137         return 0;
 138 }
 139
 140 static inline void vlan_vid_del(struct net_device *dev, unsigned short vid)
 141 {
 142 }
 143
 144 static inline int vlan_vids_add_by_dev(struct net_device *dev,
 145                                        const struct net_device *by_dev)
 146 {
 147         return 0;
 148 }
 149
 150 static inline void vlan_vids_del_by_dev(struct net_device *dev,
 151                                         const struct net_device *by_dev)
 152 {
 153 }
 154 #endif
 155
 156 /**
 157  * vlan_insert_tag - regular VLAN tag inserting
 158  * @skb: skbuff to tag
 159  * @vlan_tci: VLAN TCI to insert
 160  *
 161  * Inserts the VLAN tag into @skb as part of the payload
 162  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 163  *
 164  * Following the skb_unshare() example, in case of error, the calling function
 165  * doesn't have to worry about freeing the original skb.
 166  *
 167  * Does not change skb->protocol so this function can be used during receive.
 168  */
 169 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 170 {
 171         struct vlan_ethhdr *veth;
 172
 173         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 174                 kfree_skb(skb);
 175                 return NULL;
 176         }
 177         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 178
 179         /* Move the mac addresses to the beginning of the new header. */
 180         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 181         skb->mac_header -= VLAN_HLEN;
 182
 183         /* first, the ethernet type */
 184         veth->h_vlan_proto = htons(ETH_P_8021Q);
 185
 186         /* now, the TCI */
 187         veth->h_vlan_TCI = htons(vlan_tci);
 188
 189         return skb;
 190 }
 191
 192 /**
 193  * __vlan_put_tag - regular VLAN tag inserting
 194  * @skb: skbuff to tag
 195  * @vlan_tci: VLAN TCI to insert
 196  *
 197  * Inserts the VLAN tag into @skb as part of the payload
 198  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 199  *
 200  * Following the skb_unshare() example, in case of error, the calling function
 201  * doesn't have to worry about freeing the original skb.
 202  */
 203 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 204 {
 205         skb = vlan_insert_tag(skb, vlan_tci);
 206         if (skb)
 207                 skb->protocol = htons(ETH_P_8021Q);
 208         return skb;
 209 }
 210
 211 /**
 212  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 213  * @skb: skbuff to tag
 214  * @vlan_tci: VLAN TCI to insert
 215  *
 216  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 217  */
 218 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 219                                                      u16 vlan_tci)
 220 {
 221         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 222         return skb;
 223 }
 224
 225 #define HAVE_VLAN_PUT_TAG
 226
 227 /**
 228  * vlan_put_tag - inserts VLAN tag according to device features
 229  * @skb: skbuff to tag
 230  * @vlan_tci: VLAN TCI to insert
 231  *
 232  * Assumes skb->dev is the target that will xmit this frame.
 233  * Returns a VLAN tagged skb.
 234  */
 235 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 236 {
 237         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 238                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 239         } else {
 240                 return __vlan_put_tag(skb, vlan_tci);
 241         }
 242 }
 243
 244 /**
 245  * __vlan_get_tag - get the VLAN ID that is part of the payload
 246  * @skb: skbuff to query
 247  * @vlan_tci: buffer to store vlaue
 248  *
 249  * Returns error if the skb is not of VLAN type
 250  */
 251 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 252 {
 253         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 254
 255         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 256                 return -EINVAL;
 257         }
 258
 259         *vlan_tci = ntohs(veth->h_vlan_TCI);
 260         return 0;
 261 }
 262
 263 /**
 264  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 265  * @skb: skbuff to query
 266  * @vlan_tci: buffer to store vlaue
 267  *
 268  * Returns error if @skb->vlan_tci is not set correctly
 269  */
 270 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 271                                          u16 *vlan_tci)
 272 {
 273         if (vlan_tx_tag_present(skb)) {
 274                 *vlan_tci = vlan_tx_tag_get(skb);
 275                 return 0;
 276         } else {
 277                 *vlan_tci = 0;
 278                 return -EINVAL;
 279         }
 280 }
 281
 282 #define HAVE_VLAN_GET_TAG
 283
 284 /**
 285  * vlan_get_tag - get the VLAN ID from the skb
 286  * @skb: skbuff to query
 287  * @vlan_tci: buffer to store vlaue
 288  *
 289  * Returns error if the skb is not VLAN tagged
 290  */
 291 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 292 {
 293         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 294                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 295         } else {
 296                 return __vlan_get_tag(skb, vlan_tci);
 297         }
 298 }
 299
 300 /**
 301  * vlan_get_protocol - get protocol EtherType.
 302  * @skb: skbuff to query
 303  *
 304  * Returns the EtherType of the packet, regardless of whether it is
 305  * vlan encapsulated (normal or hardware accelerated) or not.
 306  */
 307 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 308 {
 309         __be16 protocol = 0;
 310
 311         if (vlan_tx_tag_present(skb) ||
 312              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 313                 protocol = skb->protocol;
 314         else {
 315                 __be16 proto, *protop;
 316                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 317                                                 h_vlan_encapsulated_proto),
 318                                                 sizeof(proto), &proto);
 319                 if (likely(protop))
 320                         protocol = *protop;
 321         }
 322
 323         return protocol;
 324 }
 325
 326 static inline void vlan_set_encap_proto(struct sk_buff *skb,
 327                                         struct vlan_hdr *vhdr)
 328 {
 329         __be16 proto;
 330         unsigned char *rawp;
 331
 332         /*
 333          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 334          * three protocols care about.
 335          */
 336
 337         proto = vhdr->h_vlan_encapsulated_proto;
 338         if (ntohs(proto) >= 1536) {
 339                 skb->protocol = proto;
 340                 return;
 341         }
 342
 343         rawp = skb->data;
 344         if (*(unsigned short *) rawp == 0xFFFF)
 345                 /*
 346                  * This is a magic hack to spot IPX packets. Older Novell
 347                  * breaks the protocol design and runs IPX over 802.3 without
 348                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 349                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 350                  * but does for the rest.
 351                  */
 352                 skb->protocol = htons(ETH_P_802_3);
 353         else
 354                 /*
 355                  * Real 802.2 LLC
 356                  */
 357                 skb->protocol = htons(ETH_P_802_2);
 358 }
 359 #endif /* __KERNEL__ */
 360
 361 /* VLAN IOCTLs are found in sockios.h */
 362
 363 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 364 enum vlan_ioctl_cmds {
 365         ADD_VLAN_CMD,
 366         DEL_VLAN_CMD,
 367         SET_VLAN_INGRESS_PRIORITY_CMD,
 368         SET_VLAN_EGRESS_PRIORITY_CMD,
 369         GET_VLAN_INGRESS_PRIORITY_CMD,
 370         GET_VLAN_EGRESS_PRIORITY_CMD,
 371         SET_VLAN_NAME_TYPE_CMD,
 372         SET_VLAN_FLAG_CMD,
 373         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 374         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 375 };
 376
 377 enum vlan_flags {
 378         VLAN_FLAG_REORDER_HDR   = 0x1,
 379         VLAN_FLAG_GVRP          = 0x2,
 380         VLAN_FLAG_LOOSE_BINDING = 0x4,
 381 };
 382
 383 enum vlan_name_types {
 384         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 385         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 386         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 387         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 388         VLAN_NAME_TYPE_HIGHEST
 389 };
 390
 391 struct vlan_ioctl_args {
 392         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 393         char device1[24];
 394
 395         union {
 396                 char device2[24];
 397                 int VID;
 398                 unsigned int skb_priority;
 399                 unsigned int name_type;
 400                 unsigned int bind_type;
 401                 unsigned int flag; /* Matches vlan_dev_priv flags */
 402         } u;
 403
 404         short vlan_qos;
 405 };
 406
 407 #endif /* !(_LINUX_IF_VLAN_H_) */