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_hwaccel_do_receive(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_hwaccel_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 gro_result_t
 177 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 178                  unsigned int vlan_tci, struct sk_buff *skb)
 179 {
 180         return GRO_DROP;
 181 }
 182
 183 static inline gro_result_t
 184 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 185                unsigned int vlan_tci)
 186 {
 187         return GRO_DROP;
 188 }
 189 #endif
 190
 191 /**
 192  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 193  * @skb: buffer
 194  * @grp: vlan group
 195  * @vlan_tci: VLAN TCI as received from the card
 196  */
 197 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 198                                   struct vlan_group *grp,
 199                                   u16 vlan_tci)
 200 {
 201         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 202 }
 203
 204 /**
 205  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 206  * @skb: buffer
 207  * @grp: vlan group
 208  * @vlan_tci: VLAN TCI as received from the card
 209  */
 210 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 211                                            struct vlan_group *grp,
 212                                            u16 vlan_tci)
 213 {
 214         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 215 }
 216
 217 /**
 218  * __vlan_put_tag - regular VLAN tag inserting
 219  * @skb: skbuff to tag
 220  * @vlan_tci: VLAN TCI to insert
 221  *
 222  * Inserts the VLAN tag into @skb as part of the payload
 223  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 224  *
 225  * Following the skb_unshare() example, in case of error, the calling function
 226  * doesn't have to worry about freeing the original skb.
 227  */
 228 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 229 {
 230         struct vlan_ethhdr *veth;
 231
 232         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 233                 kfree_skb(skb);
 234                 return NULL;
 235         }
 236         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 237
 238         /* Move the mac addresses to the beginning of the new header. */
 239         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 240         skb->mac_header -= VLAN_HLEN;
 241
 242         /* first, the ethernet type */
 243         veth->h_vlan_proto = htons(ETH_P_8021Q);
 244
 245         /* now, the TCI */
 246         veth->h_vlan_TCI = htons(vlan_tci);
 247
 248         skb->protocol = htons(ETH_P_8021Q);
 249
 250         return skb;
 251 }
 252
 253 /**
 254  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 255  * @skb: skbuff to tag
 256  * @vlan_tci: VLAN TCI to insert
 257  *
 258  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 259  */
 260 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 261                                                      u16 vlan_tci)
 262 {
 263         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 264         return skb;
 265 }
 266
 267 #define HAVE_VLAN_PUT_TAG
 268
 269 /**
 270  * vlan_put_tag - inserts VLAN tag according to device features
 271  * @skb: skbuff to tag
 272  * @vlan_tci: VLAN TCI to insert
 273  *
 274  * Assumes skb->dev is the target that will xmit this frame.
 275  * Returns a VLAN tagged skb.
 276  */
 277 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 278 {
 279         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 280                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 281         } else {
 282                 return __vlan_put_tag(skb, vlan_tci);
 283         }
 284 }
 285
 286 /**
 287  * __vlan_get_tag - get the VLAN ID that is part of the payload
 288  * @skb: skbuff to query
 289  * @vlan_tci: buffer to store vlaue
 290  *
 291  * Returns error if the skb is not of VLAN type
 292  */
 293 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 294 {
 295         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 296
 297         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 298                 return -EINVAL;
 299         }
 300
 301         *vlan_tci = ntohs(veth->h_vlan_TCI);
 302         return 0;
 303 }
 304
 305 /**
 306  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 307  * @skb: skbuff to query
 308  * @vlan_tci: buffer to store vlaue
 309  *
 310  * Returns error if @skb->vlan_tci is not set correctly
 311  */
 312 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 313                                          u16 *vlan_tci)
 314 {
 315         if (vlan_tx_tag_present(skb)) {
 316                 *vlan_tci = vlan_tx_tag_get(skb);
 317                 return 0;
 318         } else {
 319                 *vlan_tci = 0;
 320                 return -EINVAL;
 321         }
 322 }
 323
 324 #define HAVE_VLAN_GET_TAG
 325
 326 /**
 327  * vlan_get_tag - get the VLAN ID from the skb
 328  * @skb: skbuff to query
 329  * @vlan_tci: buffer to store vlaue
 330  *
 331  * Returns error if the skb is not VLAN tagged
 332  */
 333 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 334 {
 335         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 336                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 337         } else {
 338                 return __vlan_get_tag(skb, vlan_tci);
 339         }
 340 }
 341
 342 /**
 343  * vlan_get_protocol - get protocol EtherType.
 344  * @skb: skbuff to query
 345  *
 346  * Returns the EtherType of the packet, regardless of whether it is
 347  * vlan encapsulated (normal or hardware accelerated) or not.
 348  */
 349 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 350 {
 351         __be16 protocol = 0;
 352
 353         if (vlan_tx_tag_present(skb) ||
 354              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 355                 protocol = skb->protocol;
 356         else {
 357                 __be16 proto, *protop;
 358                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 359                                                 h_vlan_encapsulated_proto),
 360                                                 sizeof(proto), &proto);
 361                 if (likely(protop))
 362                         protocol = *protop;
 363         }
 364
 365         return protocol;
 366 }
 367 #endif /* __KERNEL__ */
 368
 369 /* VLAN IOCTLs are found in sockios.h */
 370
 371 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 372 enum vlan_ioctl_cmds {
 373         ADD_VLAN_CMD,
 374         DEL_VLAN_CMD,
 375         SET_VLAN_INGRESS_PRIORITY_CMD,
 376         SET_VLAN_EGRESS_PRIORITY_CMD,
 377         GET_VLAN_INGRESS_PRIORITY_CMD,
 378         GET_VLAN_EGRESS_PRIORITY_CMD,
 379         SET_VLAN_NAME_TYPE_CMD,
 380         SET_VLAN_FLAG_CMD,
 381         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 382         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 383 };
 384
 385 enum vlan_flags {
 386         VLAN_FLAG_REORDER_HDR   = 0x1,
 387         VLAN_FLAG_GVRP          = 0x2,
 388         VLAN_FLAG_LOOSE_BINDING = 0x4,
 389 };
 390
 391 enum vlan_name_types {
 392         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 393         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 394         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 395         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 396         VLAN_NAME_TYPE_HIGHEST
 397 };
 398
 399 struct vlan_ioctl_args {
 400         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 401         char device1[24];
 402
 403         union {
 404                 char device2[24];
 405                 int VID;
 406                 unsigned int skb_priority;
 407                 unsigned int name_type;
 408                 unsigned int bind_type;
 409                 unsigned int flag; /* Matches vlan_dev_info flags */
 410         } u;
 411
 412         short vlan_qos;
 413 };
 414
 415 #endif /* !(_LINUX_IF_VLAN_H_) */