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 required by VLAN
  22                                          * (in addition to the Ethernet header)
  23                                          */
  24 #define VLAN_ETH_HLEN   18              /* Total octets in header.       */
  25 #define VLAN_ETH_ZLEN   64              /* Min. octets in frame sans FCS */
  26
  27 /*
  28  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  29  */
  30 #define VLAN_ETH_DATA_LEN       1500    /* Max. octets in payload        */
  31 #define VLAN_ETH_FRAME_LEN      1518    /* Max. octets in frame sans FCS */
  32
  33 /*
  34  *      struct vlan_hdr - vlan header
  35  *      @h_vlan_TCI: priority and VLAN ID
  36  *      @h_vlan_encapsulated_proto: packet type ID or len
  37  */
  38 struct vlan_hdr {
  39         __be16  h_vlan_TCI;
  40         __be16  h_vlan_encapsulated_proto;
  41 };
  42
  43 /**
  44  *      struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  45  *      @h_dest: destination ethernet address
  46  *      @h_source: source ethernet address
  47  *      @h_vlan_proto: ethernet protocol (always 0x8100)
  48  *      @h_vlan_TCI: priority and VLAN ID
  49  *      @h_vlan_encapsulated_proto: packet type ID or len
  50  */
  51 struct vlan_ethhdr {
  52         unsigned char   h_dest[ETH_ALEN];
  53         unsigned char   h_source[ETH_ALEN];
  54         __be16          h_vlan_proto;
  55         __be16          h_vlan_TCI;
  56         __be16          h_vlan_encapsulated_proto;
  57 };
  58
  59 #include <linux/skbuff.h>
  60
  61 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  62 {
  63         return (struct vlan_ethhdr *)skb_mac_header(skb);
  64 }
  65
  66 #define VLAN_PRIO_MASK          0xe000 /* Priority Code Point */
  67 #define VLAN_PRIO_SHIFT         13
  68 #define VLAN_CFI_MASK           0x1000 /* Canonical Format Indicator */
  69 #define VLAN_TAG_PRESENT        VLAN_CFI_MASK
  70 #define VLAN_VID_MASK           0x0fff /* VLAN Identifier */
  71 #define VLAN_N_VID              4096
  72
  73 /* found in socket.c */
  74 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  75
  76 struct vlan_info;
  77
  78 static inline int is_vlan_dev(struct net_device *dev)
  79 {
  80         return dev->priv_flags & IFF_802_1Q_VLAN;
  81 }
  82
  83 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  84 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  85
  86 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  87
  88 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  89                                                u16 vlan_id);
  90 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  91 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  92
  93 extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler);
  94 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
  95
  96 extern int vlan_vid_add(struct net_device *dev, unsigned short vid);
  97 extern void vlan_vid_del(struct net_device *dev, unsigned short vid);
  98
  99 extern int vlan_vids_add_by_dev(struct net_device *dev,
 100                                 const struct net_device *by_dev);
 101 extern void vlan_vids_del_by_dev(struct net_device *dev,
 102                                  const struct net_device *by_dev);
 103 #else
 104 static inline struct net_device *
 105 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
 106 {
 107         return NULL;
 108 }
 109
 110 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 111 {
 112         BUG();
 113         return NULL;
 114 }
 115
 116 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 117 {
 118         BUG();
 119         return 0;
 120 }
 121
 122 static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler)
 123 {
 124         if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler)
 125                 (*skb)->pkt_type = PACKET_OTHERHOST;
 126         return false;
 127 }
 128
 129 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 130 {
 131         return skb;
 132 }
 133
 134 static inline int vlan_vid_add(struct net_device *dev, unsigned short vid)
 135 {
 136         return 0;
 137 }
 138
 139 static inline void vlan_vid_del(struct net_device *dev, unsigned short vid)
 140 {
 141 }
 142
 143 static inline int vlan_vids_add_by_dev(struct net_device *dev,
 144                                        const struct net_device *by_dev)
 145 {
 146         return 0;
 147 }
 148
 149 static inline void vlan_vids_del_by_dev(struct net_device *dev,
 150                                         const struct net_device *by_dev)
 151 {
 152 }
 153 #endif
 154
 155 /**
 156  * vlan_insert_tag - regular VLAN tag inserting
 157  * @skb: skbuff to tag
 158  * @vlan_tci: VLAN TCI to insert
 159  *
 160  * Inserts the VLAN tag into @skb as part of the payload
 161  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 162  *
 163  * Following the skb_unshare() example, in case of error, the calling function
 164  * doesn't have to worry about freeing the original skb.
 165  *
 166  * Does not change skb->protocol so this function can be used during receive.
 167  */
 168 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 169 {
 170         struct vlan_ethhdr *veth;
 171
 172         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 173                 kfree_skb(skb);
 174                 return NULL;
 175         }
 176         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 177
 178         /* Move the mac addresses to the beginning of the new header. */
 179         memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
 180         skb->mac_header -= VLAN_HLEN;
 181
 182         /* first, the ethernet type */
 183         veth->h_vlan_proto = htons(ETH_P_8021Q);
 184
 185         /* now, the TCI */
 186         veth->h_vlan_TCI = htons(vlan_tci);
 187
 188         return skb;
 189 }
 190
 191 /**
 192  * __vlan_put_tag - regular VLAN tag inserting
 193  * @skb: skbuff to tag
 194  * @vlan_tci: VLAN TCI to insert
 195  *
 196  * Inserts the VLAN tag into @skb as part of the payload
 197  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 198  *
 199  * Following the skb_unshare() example, in case of error, the calling function
 200  * doesn't have to worry about freeing the original skb.
 201  */
 202 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 203 {
 204         skb = vlan_insert_tag(skb, vlan_tci);
 205         if (skb)
 206                 skb->protocol = htons(ETH_P_8021Q);
 207         return skb;
 208 }
 209
 210 /**
 211  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 212  * @skb: skbuff to tag
 213  * @vlan_tci: VLAN TCI to insert
 214  *
 215  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 216  */
 217 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 218                                                      u16 vlan_tci)
 219 {
 220         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 221         return skb;
 222 }
 223
 224 #define HAVE_VLAN_PUT_TAG
 225
 226 /**
 227  * vlan_put_tag - inserts VLAN tag according to device features
 228  * @skb: skbuff to tag
 229  * @vlan_tci: VLAN TCI to insert
 230  *
 231  * Assumes skb->dev is the target that will xmit this frame.
 232  * Returns a VLAN tagged skb.
 233  */
 234 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 235 {
 236         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 237                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 238         } else {
 239                 return __vlan_put_tag(skb, vlan_tci);
 240         }
 241 }
 242
 243 /**
 244  * __vlan_get_tag - get the VLAN ID that is part of the payload
 245  * @skb: skbuff to query
 246  * @vlan_tci: buffer to store vlaue
 247  *
 248  * Returns error if the skb is not of VLAN type
 249  */
 250 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 251 {
 252         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 253
 254         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 255                 return -EINVAL;
 256         }
 257
 258         *vlan_tci = ntohs(veth->h_vlan_TCI);
 259         return 0;
 260 }
 261
 262 /**
 263  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 264  * @skb: skbuff to query
 265  * @vlan_tci: buffer to store vlaue
 266  *
 267  * Returns error if @skb->vlan_tci is not set correctly
 268  */
 269 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 270                                          u16 *vlan_tci)
 271 {
 272         if (vlan_tx_tag_present(skb)) {
 273                 *vlan_tci = vlan_tx_tag_get(skb);
 274                 return 0;
 275         } else {
 276                 *vlan_tci = 0;
 277                 return -EINVAL;
 278         }
 279 }
 280
 281 #define HAVE_VLAN_GET_TAG
 282
 283 /**
 284  * vlan_get_tag - get the VLAN ID from the skb
 285  * @skb: skbuff to query
 286  * @vlan_tci: buffer to store vlaue
 287  *
 288  * Returns error if the skb is not VLAN tagged
 289  */
 290 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 291 {
 292         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 293                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 294         } else {
 295                 return __vlan_get_tag(skb, vlan_tci);
 296         }
 297 }
 298
 299 /**
 300  * vlan_get_protocol - get protocol EtherType.
 301  * @skb: skbuff to query
 302  *
 303  * Returns the EtherType of the packet, regardless of whether it is
 304  * vlan encapsulated (normal or hardware accelerated) or not.
 305  */
 306 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 307 {
 308         __be16 protocol = 0;
 309
 310         if (vlan_tx_tag_present(skb) ||
 311              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 312                 protocol = skb->protocol;
 313         else {
 314                 __be16 proto, *protop;
 315                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 316                                                 h_vlan_encapsulated_proto),
 317                                                 sizeof(proto), &proto);
 318                 if (likely(protop))
 319                         protocol = *protop;
 320         }
 321
 322         return protocol;
 323 }
 324
 325 static inline void vlan_set_encap_proto(struct sk_buff *skb,
 326                                         struct vlan_hdr *vhdr)
 327 {
 328         __be16 proto;
 329         unsigned char *rawp;
 330
 331         /*
 332          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 333          * three protocols care about.
 334          */
 335
 336         proto = vhdr->h_vlan_encapsulated_proto;
 337         if (ntohs(proto) >= 1536) {
 338                 skb->protocol = proto;
 339                 return;
 340         }
 341
 342         rawp = skb->data;
 343         if (*(unsigned short *) rawp == 0xFFFF)
 344                 /*
 345                  * This is a magic hack to spot IPX packets. Older Novell
 346                  * breaks the protocol design and runs IPX over 802.3 without
 347                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 348                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 349                  * but does for the rest.
 350                  */
 351                 skb->protocol = htons(ETH_P_802_3);
 352         else
 353                 /*
 354                  * Real 802.2 LLC
 355                  */
 356                 skb->protocol = htons(ETH_P_802_2);
 357 }
 358 #endif /* __KERNEL__ */
 359
 360 /* VLAN IOCTLs are found in sockios.h */
 361
 362 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 363 enum vlan_ioctl_cmds {
 364         ADD_VLAN_CMD,
 365         DEL_VLAN_CMD,
 366         SET_VLAN_INGRESS_PRIORITY_CMD,
 367         SET_VLAN_EGRESS_PRIORITY_CMD,
 368         GET_VLAN_INGRESS_PRIORITY_CMD,
 369         GET_VLAN_EGRESS_PRIORITY_CMD,
 370         SET_VLAN_NAME_TYPE_CMD,
 371         SET_VLAN_FLAG_CMD,
 372         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 373         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 374 };
 375
 376 enum vlan_flags {
 377         VLAN_FLAG_REORDER_HDR   = 0x1,
 378         VLAN_FLAG_GVRP          = 0x2,
 379         VLAN_FLAG_LOOSE_BINDING = 0x4,
 380 };
 381
 382 enum vlan_name_types {
 383         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 384         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 385         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 386         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 387         VLAN_NAME_TYPE_HIGHEST
 388 };
 389
 390 struct vlan_ioctl_args {
 391         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 392         char device1[24];
 393
 394         union {
 395                 char device2[24];
 396                 int VID;
 397                 unsigned int skb_priority;
 398                 unsigned int name_type;
 399                 unsigned int bind_type;
 400                 unsigned int flag; /* Matches vlan_dev_priv flags */
 401         } u;
 402
 403         short vlan_qos;
 404 };
 405
 406 #endif /* !(_LINUX_IF_VLAN_H_) */