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         int                     killall;
  90         struct hlist_node       hlist;  /* linked list */
  91         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  92         struct rcu_head         rcu;
  93 };
  94
  95 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  96                                                        u16 vlan_id)
  97 {
  98         struct net_device **array;
  99         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 100         return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
 101 }
 102
 103 static inline void vlan_group_set_device(struct vlan_group *vg,
 104                                          u16 vlan_id,
 105                                          struct net_device *dev)
 106 {
 107         struct net_device **array;
 108         if (!vg)
 109                 return;
 110         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 111         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 112 }
 113
 114 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
 115 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
 116
 117 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 118 /* Must be invoked with rcu_read_lock or with RTNL. */
 119 static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
 120                                                u16 vlan_id)
 121 {
 122         struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);
 123
 124         if (grp)
 125                 return vlan_group_get_device(grp, vlan_id);
 126
 127         return NULL;
 128 }
 129
 130 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 131 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 132
 133 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 134                              u16 vlan_tci, int polling);
 135 extern bool vlan_do_receive(struct sk_buff **skb);
 136 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 137 extern gro_result_t
 138 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 139                  unsigned int vlan_tci, struct sk_buff *skb);
 140 extern gro_result_t
 141 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 142                unsigned int vlan_tci);
 143
 144 #else
 145 static inline struct net_device *vlan_find_dev(struct net_device *real_dev,
 146                                                u16 vlan_id)
 147 {
 148         return NULL;
 149 }
 150
 151 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 152 {
 153         BUG();
 154         return NULL;
 155 }
 156
 157 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 158 {
 159         BUG();
 160         return 0;
 161 }
 162
 163 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 164                                     u16 vlan_tci, int polling)
 165 {
 166         BUG();
 167         return NET_XMIT_SUCCESS;
 168 }
 169
 170 static inline bool vlan_do_receive(struct sk_buff **skb)
 171 {
 172         if ((*skb)->vlan_tci & VLAN_VID_MASK)
 173                 (*skb)->pkt_type = PACKET_OTHERHOST;
 174         return false;
 175 }
 176
 177 inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 178 {
 179         return skb;
 180 }
 181
 182 static inline gro_result_t
 183 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 184                  unsigned int vlan_tci, struct sk_buff *skb)
 185 {
 186         return GRO_DROP;
 187 }
 188
 189 static inline gro_result_t
 190 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 191                unsigned int vlan_tci)
 192 {
 193         return GRO_DROP;
 194 }
 195 #endif
 196
 197 /**
 198  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 199  * @skb: buffer
 200  * @grp: vlan group
 201  * @vlan_tci: VLAN TCI as received from the card
 202  */
 203 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 204                                   struct vlan_group *grp,
 205                                   u16 vlan_tci)
 206 {
 207         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 208 }
 209
 210 /**
 211  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 212  * @skb: buffer
 213  * @grp: vlan group
 214  * @vlan_tci: VLAN TCI as received from the card
 215  */
 216 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 217                                            struct vlan_group *grp,
 218                                            u16 vlan_tci)
 219 {
 220         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 221 }
 222
 223 /**
 224  * __vlan_put_tag - regular VLAN tag inserting
 225  * @skb: skbuff to tag
 226  * @vlan_tci: VLAN TCI to insert
 227  *
 228  * Inserts the VLAN tag into @skb as part of the payload
 229  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 230  *
 231  * Following the skb_unshare() example, in case of error, the calling function
 232  * doesn't have to worry about freeing the original skb.
 233  */
 234 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 235 {
 236         struct vlan_ethhdr *veth;
 237
 238         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 239                 kfree_skb(skb);
 240                 return NULL;
 241         }
 242         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 243
 244         /* Move the mac addresses to the beginning of the new header. */
 245         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 246         skb->mac_header -= VLAN_HLEN;
 247
 248         /* first, the ethernet type */
 249         veth->h_vlan_proto = htons(ETH_P_8021Q);
 250
 251         /* now, the TCI */
 252         veth->h_vlan_TCI = htons(vlan_tci);
 253
 254         skb->protocol = htons(ETH_P_8021Q);
 255
 256         return skb;
 257 }
 258
 259 /**
 260  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 261  * @skb: skbuff to tag
 262  * @vlan_tci: VLAN TCI to insert
 263  *
 264  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 265  */
 266 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 267                                                      u16 vlan_tci)
 268 {
 269         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 270         return skb;
 271 }
 272
 273 #define HAVE_VLAN_PUT_TAG
 274
 275 /**
 276  * vlan_put_tag - inserts VLAN tag according to device features
 277  * @skb: skbuff to tag
 278  * @vlan_tci: VLAN TCI to insert
 279  *
 280  * Assumes skb->dev is the target that will xmit this frame.
 281  * Returns a VLAN tagged skb.
 282  */
 283 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 284 {
 285         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 286                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 287         } else {
 288                 return __vlan_put_tag(skb, vlan_tci);
 289         }
 290 }
 291
 292 /**
 293  * __vlan_get_tag - get the VLAN ID that is part of the payload
 294  * @skb: skbuff to query
 295  * @vlan_tci: buffer to store vlaue
 296  *
 297  * Returns error if the skb is not of VLAN type
 298  */
 299 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 300 {
 301         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 302
 303         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 304                 return -EINVAL;
 305         }
 306
 307         *vlan_tci = ntohs(veth->h_vlan_TCI);
 308         return 0;
 309 }
 310
 311 /**
 312  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 313  * @skb: skbuff to query
 314  * @vlan_tci: buffer to store vlaue
 315  *
 316  * Returns error if @skb->vlan_tci is not set correctly
 317  */
 318 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 319                                          u16 *vlan_tci)
 320 {
 321         if (vlan_tx_tag_present(skb)) {
 322                 *vlan_tci = vlan_tx_tag_get(skb);
 323                 return 0;
 324         } else {
 325                 *vlan_tci = 0;
 326                 return -EINVAL;
 327         }
 328 }
 329
 330 #define HAVE_VLAN_GET_TAG
 331
 332 /**
 333  * vlan_get_tag - get the VLAN ID from the skb
 334  * @skb: skbuff to query
 335  * @vlan_tci: buffer to store vlaue
 336  *
 337  * Returns error if the skb is not VLAN tagged
 338  */
 339 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 340 {
 341         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 342                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 343         } else {
 344                 return __vlan_get_tag(skb, vlan_tci);
 345         }
 346 }
 347
 348 /**
 349  * vlan_get_protocol - get protocol EtherType.
 350  * @skb: skbuff to query
 351  *
 352  * Returns the EtherType of the packet, regardless of whether it is
 353  * vlan encapsulated (normal or hardware accelerated) or not.
 354  */
 355 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 356 {
 357         __be16 protocol = 0;
 358
 359         if (vlan_tx_tag_present(skb) ||
 360              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 361                 protocol = skb->protocol;
 362         else {
 363                 __be16 proto, *protop;
 364                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 365                                                 h_vlan_encapsulated_proto),
 366                                                 sizeof(proto), &proto);
 367                 if (likely(protop))
 368                         protocol = *protop;
 369         }
 370
 371         return protocol;
 372 }
 373 #endif /* __KERNEL__ */
 374
 375 /* VLAN IOCTLs are found in sockios.h */
 376
 377 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 378 enum vlan_ioctl_cmds {
 379         ADD_VLAN_CMD,
 380         DEL_VLAN_CMD,
 381         SET_VLAN_INGRESS_PRIORITY_CMD,
 382         SET_VLAN_EGRESS_PRIORITY_CMD,
 383         GET_VLAN_INGRESS_PRIORITY_CMD,
 384         GET_VLAN_EGRESS_PRIORITY_CMD,
 385         SET_VLAN_NAME_TYPE_CMD,
 386         SET_VLAN_FLAG_CMD,
 387         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 388         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 389 };
 390
 391 enum vlan_flags {
 392         VLAN_FLAG_REORDER_HDR   = 0x1,
 393         VLAN_FLAG_GVRP          = 0x2,
 394         VLAN_FLAG_LOOSE_BINDING = 0x4,
 395 };
 396
 397 enum vlan_name_types {
 398         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 399         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 400         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 401         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 402         VLAN_NAME_TYPE_HIGHEST
 403 };
 404
 405 struct vlan_ioctl_args {
 406         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 407         char device1[24];
 408
 409         union {
 410                 char device2[24];
 411                 int VID;
 412                 unsigned int skb_priority;
 413                 unsigned int name_type;
 414                 unsigned int bind_type;
 415                 unsigned int flag; /* Matches vlan_dev_info flags */
 416         } u;
 417
 418         short vlan_qos;
 419 };
 420
 421 #endif /* !(_LINUX_IF_VLAN_H_) */