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 #include <linux/bug.h>
  21
  22 #define VLAN_HLEN       4               /* The additional bytes required by VLAN
  23                                          * (in addition to the Ethernet header)
  24                                          */
  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 static inline int is_vlan_dev(struct net_device *dev)
  78 {
  79         return dev->priv_flags & IFF_802_1Q_VLAN;
  80 }
  81
  82 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  83 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  84
  85 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  86
  87 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  88                                                u16 vlan_id);
  89 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  90 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  91
  92 extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler);
  93 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
  94
  95 extern int vlan_vid_add(struct net_device *dev, unsigned short vid);
  96 extern void vlan_vid_del(struct net_device *dev, unsigned short vid);
  97
  98 extern int vlan_vids_add_by_dev(struct net_device *dev,
  99                                 const struct net_device *by_dev);
 100 extern void vlan_vids_del_by_dev(struct net_device *dev,
 101                                  const struct net_device *by_dev);
 102
 103 extern bool vlan_uses_dev(const struct net_device *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
 155 static inline bool vlan_uses_dev(const struct net_device *dev)
 156 {
 157         return false;
 158 }
 159 #endif
 160
 161 /**
 162  * vlan_insert_tag - regular VLAN tag inserting
 163  * @skb: skbuff to tag
 164  * @vlan_tci: VLAN TCI to insert
 165  *
 166  * Inserts the VLAN tag into @skb as part of the payload
 167  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 168  *
 169  * Following the skb_unshare() example, in case of error, the calling function
 170  * doesn't have to worry about freeing the original skb.
 171  *
 172  * Does not change skb->protocol so this function can be used during receive.
 173  */
 174 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 175 {
 176         struct vlan_ethhdr *veth;
 177
 178         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 179                 kfree_skb(skb);
 180                 return NULL;
 181         }
 182         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 183
 184         /* Move the mac addresses to the beginning of the new header. */
 185         memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
 186         skb->mac_header -= VLAN_HLEN;
 187
 188         /* first, the ethernet type */
 189         veth->h_vlan_proto = htons(ETH_P_8021Q);
 190
 191         /* now, the TCI */
 192         veth->h_vlan_TCI = htons(vlan_tci);
 193
 194         return skb;
 195 }
 196
 197 /**
 198  * __vlan_put_tag - regular VLAN tag inserting
 199  * @skb: skbuff to tag
 200  * @vlan_tci: VLAN TCI to insert
 201  *
 202  * Inserts the VLAN tag into @skb as part of the payload
 203  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 204  *
 205  * Following the skb_unshare() example, in case of error, the calling function
 206  * doesn't have to worry about freeing the original skb.
 207  */
 208 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 209 {
 210         skb = vlan_insert_tag(skb, vlan_tci);
 211         if (skb)
 212                 skb->protocol = htons(ETH_P_8021Q);
 213         return skb;
 214 }
 215
 216 /**
 217  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 218  * @skb: skbuff to tag
 219  * @vlan_tci: VLAN TCI to insert
 220  *
 221  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 222  */
 223 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 224                                                      u16 vlan_tci)
 225 {
 226         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 227         return skb;
 228 }
 229
 230 #define HAVE_VLAN_PUT_TAG
 231
 232 /**
 233  * vlan_put_tag - inserts VLAN tag according to device features
 234  * @skb: skbuff to tag
 235  * @vlan_tci: VLAN TCI to insert
 236  *
 237  * Assumes skb->dev is the target that will xmit this frame.
 238  * Returns a VLAN tagged skb.
 239  */
 240 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 241 {
 242         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 243                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 244         } else {
 245                 return __vlan_put_tag(skb, vlan_tci);
 246         }
 247 }
 248
 249 /**
 250  * __vlan_get_tag - get the VLAN ID that is part of the payload
 251  * @skb: skbuff to query
 252  * @vlan_tci: buffer to store vlaue
 253  *
 254  * Returns error if the skb is not of VLAN type
 255  */
 256 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 257 {
 258         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 259
 260         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 261                 return -EINVAL;
 262         }
 263
 264         *vlan_tci = ntohs(veth->h_vlan_TCI);
 265         return 0;
 266 }
 267
 268 /**
 269  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 270  * @skb: skbuff to query
 271  * @vlan_tci: buffer to store vlaue
 272  *
 273  * Returns error if @skb->vlan_tci is not set correctly
 274  */
 275 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 276                                          u16 *vlan_tci)
 277 {
 278         if (vlan_tx_tag_present(skb)) {
 279                 *vlan_tci = vlan_tx_tag_get(skb);
 280                 return 0;
 281         } else {
 282                 *vlan_tci = 0;
 283                 return -EINVAL;
 284         }
 285 }
 286
 287 #define HAVE_VLAN_GET_TAG
 288
 289 /**
 290  * vlan_get_tag - get the VLAN ID from the skb
 291  * @skb: skbuff to query
 292  * @vlan_tci: buffer to store vlaue
 293  *
 294  * Returns error if the skb is not VLAN tagged
 295  */
 296 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 297 {
 298         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 299                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 300         } else {
 301                 return __vlan_get_tag(skb, vlan_tci);
 302         }
 303 }
 304
 305 /**
 306  * vlan_get_protocol - get protocol EtherType.
 307  * @skb: skbuff to query
 308  *
 309  * Returns the EtherType of the packet, regardless of whether it is
 310  * vlan encapsulated (normal or hardware accelerated) or not.
 311  */
 312 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 313 {
 314         __be16 protocol = 0;
 315
 316         if (vlan_tx_tag_present(skb) ||
 317              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 318                 protocol = skb->protocol;
 319         else {
 320                 __be16 proto, *protop;
 321                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 322                                                 h_vlan_encapsulated_proto),
 323                                                 sizeof(proto), &proto);
 324                 if (likely(protop))
 325                         protocol = *protop;
 326         }
 327
 328         return protocol;
 329 }
 330
 331 static inline void vlan_set_encap_proto(struct sk_buff *skb,
 332                                         struct vlan_hdr *vhdr)
 333 {
 334         __be16 proto;
 335         unsigned char *rawp;
 336
 337         /*
 338          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 339          * three protocols care about.
 340          */
 341
 342         proto = vhdr->h_vlan_encapsulated_proto;
 343         if (ntohs(proto) >= 1536) {
 344                 skb->protocol = proto;
 345                 return;
 346         }
 347
 348         rawp = skb->data;
 349         if (*(unsigned short *) rawp == 0xFFFF)
 350                 /*
 351                  * This is a magic hack to spot IPX packets. Older Novell
 352                  * breaks the protocol design and runs IPX over 802.3 without
 353                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 354                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 355                  * but does for the rest.
 356                  */
 357                 skb->protocol = htons(ETH_P_802_3);
 358         else
 359                 /*
 360                  * Real 802.2 LLC
 361                  */
 362                 skb->protocol = htons(ETH_P_802_2);
 363 }
 364 #endif /* __KERNEL__ */
 365
 366 /* VLAN IOCTLs are found in sockios.h */
 367
 368 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 369 enum vlan_ioctl_cmds {
 370         ADD_VLAN_CMD,
 371         DEL_VLAN_CMD,
 372         SET_VLAN_INGRESS_PRIORITY_CMD,
 373         SET_VLAN_EGRESS_PRIORITY_CMD,
 374         GET_VLAN_INGRESS_PRIORITY_CMD,
 375         GET_VLAN_EGRESS_PRIORITY_CMD,
 376         SET_VLAN_NAME_TYPE_CMD,
 377         SET_VLAN_FLAG_CMD,
 378         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 379         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 380 };
 381
 382 enum vlan_flags {
 383         VLAN_FLAG_REORDER_HDR   = 0x1,
 384         VLAN_FLAG_GVRP          = 0x2,
 385         VLAN_FLAG_LOOSE_BINDING = 0x4,
 386 };
 387
 388 enum vlan_name_types {
 389         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 390         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 391         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 392         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 393         VLAN_NAME_TYPE_HIGHEST
 394 };
 395
 396 struct vlan_ioctl_args {
 397         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 398         char device1[24];
 399
 400         union {
 401                 char device2[24];
 402                 int VID;
 403                 unsigned int skb_priority;
 404                 unsigned int name_type;
 405                 unsigned int bind_type;
 406                 unsigned int flag; /* Matches vlan_dev_priv flags */
 407         } u;
 408
 409         short vlan_qos;
 410 };
 411
 412 #endif /* !(_LINUX_IF_VLAN_H_) */