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