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
  20 #define VLAN_HLEN       4               /* The additional bytes (on top of the Ethernet header)
  21                                          * that VLAN requires.
  22                                          */
  23 #define VLAN_ETH_ALEN   6               /* Octets in one ethernet addr   */
  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_VID_MASK   0xfff
  67
  68 /* found in socket.c */
  69 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  70
  71 /* if this changes, algorithm will have to be reworked because this
  72  * depends on completely exhausting the VLAN identifier space.  Thus
  73  * it gives constant time look-up, but in many cases it wastes memory.
  74  */
  75 #define VLAN_GROUP_ARRAY_LEN          4096
  76 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  77 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  78
  79 struct vlan_group {
  80         struct net_device       *real_dev; /* The ethernet(like) device
  81                                             * the vlan is attached to.
  82                                             */
  83         unsigned int            nr_vlans;
  84         struct hlist_node       hlist;  /* linked list */
  85         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  86         struct rcu_head         rcu;
  87 };
  88
  89 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg,
  90                                                        u16 vlan_id)
  91 {
  92         struct net_device **array;
  93         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  94         return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
  95 }
  96
  97 static inline void vlan_group_set_device(struct vlan_group *vg,
  98                                          u16 vlan_id,
  99                                          struct net_device *dev)
 100 {
 101         struct net_device **array;
 102         if (!vg)
 103                 return;
 104         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
 105         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 106 }
 107
 108 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci)
 109 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci)
 110
 111 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 112 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 113 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 114
 115 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 116                              u16 vlan_tci, int polling);
 117 extern int vlan_hwaccel_do_receive(struct sk_buff *skb);
 118 extern int vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 119                             unsigned int vlan_tci, struct sk_buff *skb);
 120 extern int vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 121                           unsigned int vlan_tci);
 122
 123 #else
 124 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 125 {
 126         BUG();
 127         return NULL;
 128 }
 129
 130 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 131 {
 132         BUG();
 133         return 0;
 134 }
 135
 136 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 137                                     u16 vlan_tci, int polling)
 138 {
 139         BUG();
 140         return NET_XMIT_SUCCESS;
 141 }
 142
 143 static inline int vlan_hwaccel_do_receive(struct sk_buff *skb)
 144 {
 145         return 0;
 146 }
 147
 148 static inline int vlan_gro_receive(struct napi_struct *napi,
 149                                    struct vlan_group *grp,
 150                                    unsigned int vlan_tci, struct sk_buff *skb)
 151 {
 152         return NET_RX_DROP;
 153 }
 154
 155 static inline int vlan_gro_frags(struct napi_struct *napi,
 156                                  struct vlan_group *grp, unsigned int vlan_tci)
 157 {
 158         return NET_RX_DROP;
 159 }
 160 #endif
 161
 162 /**
 163  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 164  * @skb: buffer
 165  * @grp: vlan group
 166  * @vlan_tci: VLAN TCI as received from the card
 167  */
 168 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 169                                   struct vlan_group *grp,
 170                                   u16 vlan_tci)
 171 {
 172         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 173 }
 174
 175 /**
 176  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 177  * @skb: buffer
 178  * @grp: vlan group
 179  * @vlan_tci: VLAN TCI as received from the card
 180  */
 181 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 182                                            struct vlan_group *grp,
 183                                            u16 vlan_tci)
 184 {
 185         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 186 }
 187
 188 /**
 189  * __vlan_put_tag - regular VLAN tag inserting
 190  * @skb: skbuff to tag
 191  * @vlan_tci: VLAN TCI to insert
 192  *
 193  * Inserts the VLAN tag into @skb as part of the payload
 194  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 195  *
 196  * Following the skb_unshare() example, in case of error, the calling function
 197  * doesn't have to worry about freeing the original skb.
 198  */
 199 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 200 {
 201         struct vlan_ethhdr *veth;
 202
 203         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 204                 kfree_skb(skb);
 205                 return NULL;
 206         }
 207         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 208
 209         /* Move the mac addresses to the beginning of the new header. */
 210         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 211         skb->mac_header -= VLAN_HLEN;
 212
 213         /* first, the ethernet type */
 214         veth->h_vlan_proto = htons(ETH_P_8021Q);
 215
 216         /* now, the TCI */
 217         veth->h_vlan_TCI = htons(vlan_tci);
 218
 219         skb->protocol = htons(ETH_P_8021Q);
 220
 221         return skb;
 222 }
 223
 224 /**
 225  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 226  * @skb: skbuff to tag
 227  * @vlan_tci: VLAN TCI to insert
 228  *
 229  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 230  */
 231 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 232                                                      u16 vlan_tci)
 233 {
 234         skb->vlan_tci = vlan_tci;
 235         return skb;
 236 }
 237
 238 #define HAVE_VLAN_PUT_TAG
 239
 240 /**
 241  * vlan_put_tag - inserts VLAN tag according to device features
 242  * @skb: skbuff to tag
 243  * @vlan_tci: VLAN TCI to insert
 244  *
 245  * Assumes skb->dev is the target that will xmit this frame.
 246  * Returns a VLAN tagged skb.
 247  */
 248 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 249 {
 250         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 251                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 252         } else {
 253                 return __vlan_put_tag(skb, vlan_tci);
 254         }
 255 }
 256
 257 /**
 258  * __vlan_get_tag - get the VLAN ID that is part of the payload
 259  * @skb: skbuff to query
 260  * @vlan_tci: buffer to store vlaue
 261  *
 262  * Returns error if the skb is not of VLAN type
 263  */
 264 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 265 {
 266         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 267
 268         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 269                 return -EINVAL;
 270         }
 271
 272         *vlan_tci = ntohs(veth->h_vlan_TCI);
 273         return 0;
 274 }
 275
 276 /**
 277  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 278  * @skb: skbuff to query
 279  * @vlan_tci: buffer to store vlaue
 280  *
 281  * Returns error if @skb->vlan_tci is not set correctly
 282  */
 283 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 284                                          u16 *vlan_tci)
 285 {
 286         if (vlan_tx_tag_present(skb)) {
 287                 *vlan_tci = skb->vlan_tci;
 288                 return 0;
 289         } else {
 290                 *vlan_tci = 0;
 291                 return -EINVAL;
 292         }
 293 }
 294
 295 #define HAVE_VLAN_GET_TAG
 296
 297 /**
 298  * vlan_get_tag - get the VLAN ID from the skb
 299  * @skb: skbuff to query
 300  * @vlan_tci: buffer to store vlaue
 301  *
 302  * Returns error if the skb is not VLAN tagged
 303  */
 304 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 305 {
 306         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 307                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 308         } else {
 309                 return __vlan_get_tag(skb, vlan_tci);
 310         }
 311 }
 312
 313 #endif /* __KERNEL__ */
 314
 315 /* VLAN IOCTLs are found in sockios.h */
 316
 317 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 318 enum vlan_ioctl_cmds {
 319         ADD_VLAN_CMD,
 320         DEL_VLAN_CMD,
 321         SET_VLAN_INGRESS_PRIORITY_CMD,
 322         SET_VLAN_EGRESS_PRIORITY_CMD,
 323         GET_VLAN_INGRESS_PRIORITY_CMD,
 324         GET_VLAN_EGRESS_PRIORITY_CMD,
 325         SET_VLAN_NAME_TYPE_CMD,
 326         SET_VLAN_FLAG_CMD,
 327         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 328         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 329 };
 330
 331 enum vlan_flags {
 332         VLAN_FLAG_REORDER_HDR   = 0x1,
 333         VLAN_FLAG_GVRP          = 0x2,
 334 };
 335
 336 enum vlan_name_types {
 337         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 338         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 339         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 340         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 341         VLAN_NAME_TYPE_HIGHEST
 342 };
 343
 344 struct vlan_ioctl_args {
 345         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 346         char device1[24];
 347
 348         union {
 349                 char device2[24];
 350                 int VID;
 351                 unsigned int skb_priority;
 352                 unsigned int name_type;
 353                 unsigned int bind_type;
 354                 unsigned int flag; /* Matches vlan_dev_info flags */
 355         } u;
 356
 357         short vlan_qos;
 358 };
 359
 360 #endif /* !(_LINUX_IF_VLAN_H_) */