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_PRIO_MASK          0xe000 /* Priority Code Point */
  67 #define VLAN_PRIO_SHIFT         13
  68 #define VLAN_CFI_MASK           0x1000 /* Canonical Format Indicator */
  69 #define VLAN_TAG_PRESENT        VLAN_CFI_MASK
  70 #define VLAN_VID_MASK           0x0fff /* VLAN Identifier */
  71 #define VLAN_N_VID              4096
  72
  73 /* found in socket.c */
  74 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  75
  76 /* if this changes, algorithm will have to be reworked because this
  77  * depends on completely exhausting the VLAN identifier space.  Thus
  78  * it gives constant time look-up, but in many cases it wastes memory.
  79  */
  80 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  81 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_N_VID/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  82
  83 struct vlan_group {
  84         struct net_device       *real_dev; /* The ethernet(like) device
  85                                             * the vlan is attached to.
  86                                             */
  87         unsigned int            nr_vlans;
  88         int                     killall;
  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 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 118 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 119
 120 extern int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 121                              u16 vlan_tci, int polling);
 122 extern void vlan_hwaccel_do_receive(struct sk_buff *skb);
 123 extern gro_result_t
 124 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 125                  unsigned int vlan_tci, struct sk_buff *skb);
 126 extern gro_result_t
 127 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 128                unsigned int vlan_tci);
 129
 130 #else
 131 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 132 {
 133         BUG();
 134         return NULL;
 135 }
 136
 137 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 138 {
 139         BUG();
 140         return 0;
 141 }
 142
 143 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, struct vlan_group *grp,
 144                                     u16 vlan_tci, int polling)
 145 {
 146         BUG();
 147         return NET_XMIT_SUCCESS;
 148 }
 149
 150 static inline void vlan_hwaccel_do_receive(struct sk_buff *skb)
 151 {
 152 }
 153
 154 static inline gro_result_t
 155 vlan_gro_receive(struct napi_struct *napi, struct vlan_group *grp,
 156                  unsigned int vlan_tci, struct sk_buff *skb)
 157 {
 158         return GRO_DROP;
 159 }
 160
 161 static inline gro_result_t
 162 vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
 163                unsigned int vlan_tci)
 164 {
 165         return GRO_DROP;
 166 }
 167 #endif
 168
 169 /**
 170  * vlan_hwaccel_rx - netif_rx wrapper for VLAN RX acceleration
 171  * @skb: buffer
 172  * @grp: vlan group
 173  * @vlan_tci: VLAN TCI as received from the card
 174  */
 175 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 176                                   struct vlan_group *grp,
 177                                   u16 vlan_tci)
 178 {
 179         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 0);
 180 }
 181
 182 /**
 183  * vlan_hwaccel_receive_skb - netif_receive_skb wrapper for VLAN RX acceleration
 184  * @skb: buffer
 185  * @grp: vlan group
 186  * @vlan_tci: VLAN TCI as received from the card
 187  */
 188 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 189                                            struct vlan_group *grp,
 190                                            u16 vlan_tci)
 191 {
 192         return __vlan_hwaccel_rx(skb, grp, vlan_tci, 1);
 193 }
 194
 195 /**
 196  * __vlan_put_tag - regular VLAN tag inserting
 197  * @skb: skbuff to tag
 198  * @vlan_tci: VLAN TCI to insert
 199  *
 200  * Inserts the VLAN tag into @skb as part of the payload
 201  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 202  *
 203  * Following the skb_unshare() example, in case of error, the calling function
 204  * doesn't have to worry about freeing the original skb.
 205  */
 206 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 207 {
 208         struct vlan_ethhdr *veth;
 209
 210         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 211                 kfree_skb(skb);
 212                 return NULL;
 213         }
 214         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 215
 216         /* Move the mac addresses to the beginning of the new header. */
 217         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 218         skb->mac_header -= VLAN_HLEN;
 219
 220         /* first, the ethernet type */
 221         veth->h_vlan_proto = htons(ETH_P_8021Q);
 222
 223         /* now, the TCI */
 224         veth->h_vlan_TCI = htons(vlan_tci);
 225
 226         skb->protocol = htons(ETH_P_8021Q);
 227
 228         return skb;
 229 }
 230
 231 /**
 232  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 233  * @skb: skbuff to tag
 234  * @vlan_tci: VLAN TCI to insert
 235  *
 236  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 237  */
 238 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 239                                                      u16 vlan_tci)
 240 {
 241         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 242         return skb;
 243 }
 244
 245 #define HAVE_VLAN_PUT_TAG
 246
 247 /**
 248  * vlan_put_tag - inserts VLAN tag according to device features
 249  * @skb: skbuff to tag
 250  * @vlan_tci: VLAN TCI to insert
 251  *
 252  * Assumes skb->dev is the target that will xmit this frame.
 253  * Returns a VLAN tagged skb.
 254  */
 255 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
 256 {
 257         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 258                 return __vlan_hwaccel_put_tag(skb, vlan_tci);
 259         } else {
 260                 return __vlan_put_tag(skb, vlan_tci);
 261         }
 262 }
 263
 264 /**
 265  * __vlan_get_tag - get the VLAN ID that is part of the payload
 266  * @skb: skbuff to query
 267  * @vlan_tci: buffer to store vlaue
 268  *
 269  * Returns error if the skb is not of VLAN type
 270  */
 271 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 272 {
 273         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 274
 275         if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
 276                 return -EINVAL;
 277         }
 278
 279         *vlan_tci = ntohs(veth->h_vlan_TCI);
 280         return 0;
 281 }
 282
 283 /**
 284  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 285  * @skb: skbuff to query
 286  * @vlan_tci: buffer to store vlaue
 287  *
 288  * Returns error if @skb->vlan_tci is not set correctly
 289  */
 290 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 291                                          u16 *vlan_tci)
 292 {
 293         if (vlan_tx_tag_present(skb)) {
 294                 *vlan_tci = vlan_tx_tag_get(skb);
 295                 return 0;
 296         } else {
 297                 *vlan_tci = 0;
 298                 return -EINVAL;
 299         }
 300 }
 301
 302 #define HAVE_VLAN_GET_TAG
 303
 304 /**
 305  * vlan_get_tag - get the VLAN ID from the skb
 306  * @skb: skbuff to query
 307  * @vlan_tci: buffer to store vlaue
 308  *
 309  * Returns error if the skb is not VLAN tagged
 310  */
 311 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 312 {
 313         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 314                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 315         } else {
 316                 return __vlan_get_tag(skb, vlan_tci);
 317         }
 318 }
 319
 320 #endif /* __KERNEL__ */
 321
 322 /* VLAN IOCTLs are found in sockios.h */
 323
 324 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 325 enum vlan_ioctl_cmds {
 326         ADD_VLAN_CMD,
 327         DEL_VLAN_CMD,
 328         SET_VLAN_INGRESS_PRIORITY_CMD,
 329         SET_VLAN_EGRESS_PRIORITY_CMD,
 330         GET_VLAN_INGRESS_PRIORITY_CMD,
 331         GET_VLAN_EGRESS_PRIORITY_CMD,
 332         SET_VLAN_NAME_TYPE_CMD,
 333         SET_VLAN_FLAG_CMD,
 334         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 335         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 336 };
 337
 338 enum vlan_flags {
 339         VLAN_FLAG_REORDER_HDR   = 0x1,
 340         VLAN_FLAG_GVRP          = 0x2,
 341         VLAN_FLAG_LOOSE_BINDING = 0x4,
 342 };
 343
 344 enum vlan_name_types {
 345         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 346         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 347         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 348         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 349         VLAN_NAME_TYPE_HIGHEST
 350 };
 351
 352 struct vlan_ioctl_args {
 353         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 354         char device1[24];
 355
 356         union {
 357                 char device2[24];
 358                 int VID;
 359                 unsigned int skb_priority;
 360                 unsigned int name_type;
 361                 unsigned int bind_type;
 362                 unsigned int flag; /* Matches vlan_dev_info flags */
 363         } u;
 364
 365         short vlan_qos;
 366 };
 367
 368 #endif /* !(_LINUX_IF_VLAN_H_) */