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 extern gro_result_t
 112 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 113                  unsigned int vlan_tci, struct sk_buff *skb);
 114 extern gro_result_t
 115 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 116                unsigned int vlan_tci);
 117
 118 #else
 119 static inline struct net_device *
 120 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
 121 {
 122         return NULL;
 123 }
 124
 125 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 126 {
 127         BUG();
 128         return NULL;
 129 }
 130
 131 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 132 {
 133         BUG();
 134         return 0;
 135 }
 136
 137 static inline bool vlan_do_receive(struct sk_buff **skb)
 138 {
 139         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 140                 (*skb)->pkt_type = PACKET_OTHERHOST;
 141         return false;
 142 }
 143
 144 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 145 {
 146         return skb;
 147 }
 148
 149 static inline gro_result_t
 150 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 151                  unsigned int vlan_tci, struct sk_buff *skb)
 152 {
 153         return GRO_DROP;
 154 }
 155
 156 static inline gro_result_t
 157 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 158                unsigned int vlan_tci)
 159 {
 160         return GRO_DROP;
 161 }
 162 #endif
 163
 164 /**
 165  * vlan_insert_tag - regular VLAN tag inserting
 166  * @skb: skbuff to tag
 167  * @vlan_tci: VLAN TCI to insert
 168  *
 169  * Inserts the VLAN tag into @skb as part of the payload
 170  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 171  *
 172  * Following the skb_unshare() example, in case of error, the calling function
 173  * doesn't have to worry about freeing the original skb.
 174  *
 175  * Does not change skb->protocol so this function can be used during receive.
 176  */
 177 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
 178 {
 179         struct vlan_ethhdr *veth;
 180
 181         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 182                 kfree_skb(skb);
 183                 return NULL;
 184         }
 185         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 186
 187         /* Move the mac addresses to the beginning of the new header. */
 188         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 189         skb->mac_header -= VLAN_HLEN;
 190
 191         /* first, the ethernet type */
 192         veth->h_vlan_proto = htons(ETH_P_8021Q);
 193
 194         /* now, the TCI */
 195         veth->h_vlan_TCI = htons(vlan_tci);
 196
 197         return skb;
 198 }
 199
 200 /**
 201  * __vlan_put_tag - regular VLAN tag inserting
 202  * @skb: skbuff to tag
 203  * @vlan_tci: VLAN TCI to insert
 204  *
 205  * Inserts the VLAN tag into @skb as part of the payload
 206  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 207  *
 208  * Following the skb_unshare() example, in case of error, the calling function
 209  * doesn't have to worry about freeing the original skb.
 210  */
 211 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 212 {
 213         skb = vlan_insert_tag(skb, vlan_tci);
 214         if (skb)
 215                 skb->protocol = htons(ETH_P_8021Q);
 216         return skb;
 217 }
 218
 219 /**
 220  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 221  * @skb: skbuff to tag
 222  * @vlan_tci: VLAN TCI to insert
 223  *
 224  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 225  */
 226 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 227                                                      u16 vlan_tci)
 228 {
 229         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 230         return skb;
 231 }
 232
 233 #define HAVE_VLAN_PUT_TAG
 234
 235 /**
 236  * vlan_put_tag - inserts VLAN tag according to device features
 237  * @skb: skbuff to tag
 238  * @vlan_tci: VLAN TCI to insert
 239  *
 240  * Assumes skb->dev is the target that will xmit this frame.
 241  * Returns a VLAN tagged skb.
 242  */
 243 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 244 {
 245         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 246                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 247         } else {
 248                 return __vlan_put_tag(skb, vlan_tci);
 249         }
 250 }
 251
 252 /**
 253  * __vlan_get_tag - get the VLAN ID that is part of the payload
 254  * @skb: skbuff to query
 255  * @vlan_tci: buffer to store vlaue
 256  *
 257  * Returns error if the skb is not of VLAN type
 258  */
 259 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 260 {
 261         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 262
 263         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 264                 return -EINVAL;
 265         }
 266
 267         *vlan_tci = ntohs(veth->h_vlan_TCI);
 268         return 0;
 269 }
 270
 271 /**
 272  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 273  * @skb: skbuff to query
 274  * @vlan_tci: buffer to store vlaue
 275  *
 276  * Returns error if @skb->vlan_tci is not set correctly
 277  */
 278 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 279                                          u16 *vlan_tci)
 280 {
 281         if (vlan_tx_tag_present(skb)) {
 282                 *vlan_tci = vlan_tx_tag_get(skb);
 283                 return 0;
 284         } else {
 285                 *vlan_tci = 0;
 286                 return -EINVAL;
 287         }
 288 }
 289
 290 #define HAVE_VLAN_GET_TAG
 291
 292 /**
 293  * vlan_get_tag - get the VLAN ID from the skb
 294  * @skb: skbuff to query
 295  * @vlan_tci: buffer to store vlaue
 296  *
 297  * Returns error if the skb is not VLAN tagged
 298  */
 299 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 300 {
 301         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 302                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 303         } else {
 304                 return __vlan_get_tag(skb, vlan_tci);
 305         }
 306 }
 307
 308 /**
 309  * vlan_get_protocol - get protocol EtherType.
 310  * @skb: skbuff to query
 311  *
 312  * Returns the EtherType of the packet, regardless of whether it is
 313  * vlan encapsulated (normal or hardware accelerated) or not.
 314  */
 315 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 316 {
 317         __be16 protocol = 0;
 318
 319         if (vlan_tx_tag_present(skb) ||
 320              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 321                 protocol = skb->protocol;
 322         else {
 323                 __be16 proto, *protop;
 324                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 325                                                 h_vlan_encapsulated_proto),
 326                                                 sizeof(proto), &proto);
 327                 if (likely(protop))
 328                         protocol = *protop;
 329         }
 330
 331         return protocol;
 332 }
 333 #endif /* __KERNEL__ */
 334
 335 /* VLAN IOCTLs are found in sockios.h */
 336
 337 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 338 enum vlan_ioctl_cmds {
 339         ADD_VLAN_CMD,
 340         DEL_VLAN_CMD,
 341         SET_VLAN_INGRESS_PRIORITY_CMD,
 342         SET_VLAN_EGRESS_PRIORITY_CMD,
 343         GET_VLAN_INGRESS_PRIORITY_CMD,
 344         GET_VLAN_EGRESS_PRIORITY_CMD,
 345         SET_VLAN_NAME_TYPE_CMD,
 346         SET_VLAN_FLAG_CMD,
 347         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 348         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 349 };
 350
 351 enum vlan_flags {
 352         VLAN_FLAG_REORDER_HDR   = 0x1,
 353         VLAN_FLAG_GVRP          = 0x2,
 354         VLAN_FLAG_LOOSE_BINDING = 0x4,
 355 };
 356
 357 enum vlan_name_types {
 358         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 359         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 360         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 361         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 362         VLAN_NAME_TYPE_HIGHEST
 363 };
 364
 365 struct vlan_ioctl_args {
 366         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 367         char device1[24];
 368
 369         union {
 370                 char device2[24];
 371                 int VID;
 372                 unsigned int skb_priority;
 373                 unsigned int name_type;
 374                 unsigned int bind_type;
 375                 unsigned int flag; /* Matches vlan_dev_info flags */
 376         } u;
 377
 378         short vlan_qos;
 379 };
 380
 381 #endif /* !(_LINUX_IF_VLAN_H_) */