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
  18 /* externally defined structs */
  19 struct vlan_group;
  20 struct net_device;
  21 struct packet_type;
  22 struct vlan_collection;
  23 struct vlan_dev_info;
  24 struct hlist_node;
  25
  26 #include <linux/netdevice.h>
  27 #include <linux/etherdevice.h>
  28
  29 #define VLAN_HLEN       4               /* The additional bytes (on top of the Ethernet header)
  30                                          * that VLAN requires.
  31                                          */
  32 #define VLAN_ETH_ALEN   6               /* Octets in one ethernet addr   */
  33 #define VLAN_ETH_HLEN   18              /* Total octets in header.       */
  34 #define VLAN_ETH_ZLEN   64              /* Min. octets in frame sans FCS */
  35
  36 /*
  37  * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  38  */
  39 #define VLAN_ETH_DATA_LEN       1500    /* Max. octets in payload        */
  40 #define VLAN_ETH_FRAME_LEN      1518    /* Max. octets in frame sans FCS */
  41
  42 struct vlan_ethhdr {
  43    unsigned char        h_dest[ETH_ALEN];          /* destination eth addr      */
  44    unsigned char        h_source[ETH_ALEN];        /* source ether addr */
  45    __be16               h_vlan_proto;              /* Should always be 0x8100 */
  46    __be16               h_vlan_TCI;                /* Encapsulates priority and VLAN ID */
  47    __be16               h_vlan_encapsulated_proto; /* packet type ID field (or len) */
  48 };
  49
  50 #include <linux/skbuff.h>
  51
  52 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  53 {
  54         return (struct vlan_ethhdr *)skb_mac_header(skb);
  55 }
  56
  57 struct vlan_hdr {
  58    __be16               h_vlan_TCI;                /* Encapsulates priority and VLAN ID */
  59    __be16               h_vlan_encapsulated_proto; /* packet type ID field (or len) */
  60 };
  61
  62 #define VLAN_VID_MASK   0xfff
  63
  64 /* found in socket.c */
  65 extern void vlan_ioctl_set(int (*hook)(void __user *));
  66
  67 #define VLAN_NAME "vlan"
  68
  69 /* if this changes, algorithm will have to be reworked because this
  70  * depends on completely exhausting the VLAN identifier space.  Thus
  71  * it gives constant time look-up, but in many cases it wastes memory.
  72  */
  73 #define VLAN_GROUP_ARRAY_LEN          4096
  74 #define VLAN_GROUP_ARRAY_SPLIT_PARTS  8
  75 #define VLAN_GROUP_ARRAY_PART_LEN     (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  76
  77 struct vlan_group {
  78         int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
  79         struct hlist_node       hlist;  /* linked list */
  80         struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  81         struct rcu_head         rcu;
  82 };
  83
  84 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, int vlan_id)
  85 {
  86         struct net_device **array;
  87         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  88         return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
  89 }
  90
  91 static inline void vlan_group_set_device(struct vlan_group *vg, int vlan_id,
  92                                          struct net_device *dev)
  93 {
  94         struct net_device **array;
  95         if (!vg)
  96                 return;
  97         array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  98         array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
  99 }
 100
 101 struct vlan_priority_tci_mapping {
 102         unsigned long priority;
 103         unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
 104                                   * at provisioning time.
 105                                   * ((skb->priority << 13) & 0xE000)
 106                                   */
 107         struct vlan_priority_tci_mapping *next;
 108 };
 109
 110 /* Holds information that makes sense if this device is a VLAN device. */
 111 struct vlan_dev_info {
 112         /** This will be the mapping that correlates skb->priority to
 113          * 3 bits of VLAN QOS tags...
 114          */
 115         unsigned long ingress_priority_map[8];
 116         struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
 117
 118         unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
 119         unsigned short flags;          /* (1 << 0) re_order_header   This option will cause the
 120                                         *   VLAN code to move around the ethernet header on
 121                                         *   ingress to make the skb look **exactly** like it
 122                                         *   came in from an ethernet port.  This destroys some of
 123                                         *   the VLAN information in the skb, but it fixes programs
 124                                         *   like DHCP that use packet-filtering and don't understand
 125                                         *   802.1Q
 126                                         */
 127         struct dev_mc_list *old_mc_list;  /* old multi-cast list for the VLAN interface..
 128                                            * we save this so we can tell what changes were
 129                                            * made, in order to feed the right changes down
 130                                            * to the real hardware...
 131                                            */
 132         int old_allmulti;               /* similar to above. */
 133         int old_promiscuity;            /* similar to above. */
 134         struct net_device *real_dev;    /* the underlying device/interface */
 135         struct proc_dir_entry *dent;    /* Holds the proc data */
 136         unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
 137         unsigned long cnt_encap_on_xmit;      /* How many times did we have to encapsulate the skb on TX. */
 138         struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
 139 };
 140
 141 #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
 142
 143 /* inline functions */
 144
 145 static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
 146 {
 147         return &(VLAN_DEV_INFO(dev)->dev_stats);
 148 }
 149
 150 static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
 151                                               unsigned short vlan_tag)
 152 {
 153         struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
 154
 155         return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
 156 }
 157
 158 /* VLAN tx hw acceleration helpers. */
 159 struct vlan_skb_tx_cookie {
 160         u32     magic;
 161         u32     vlan_tag;
 162 };
 163
 164 #define VLAN_TX_COOKIE_MAGIC    0x564c414e      /* "VLAN" in ascii. */
 165 #define VLAN_TX_SKB_CB(__skb)   ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
 166 #define vlan_tx_tag_present(__skb) \
 167         (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
 168 #define vlan_tx_tag_get(__skb)  (VLAN_TX_SKB_CB(__skb)->vlan_tag)
 169
 170 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
 171 static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
 172                                     struct vlan_group *grp,
 173                                     unsigned short vlan_tag, int polling)
 174 {
 175         struct net_device_stats *stats;
 176
 177         if (skb_bond_should_drop(skb)) {
 178                 dev_kfree_skb_any(skb);
 179                 return NET_RX_DROP;
 180         }
 181
 182         skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
 183         if (skb->dev == NULL) {
 184                 dev_kfree_skb_any(skb);
 185
 186                 /* Not NET_RX_DROP, this is not being dropped
 187                  * due to congestion.
 188                  */
 189                 return 0;
 190         }
 191
 192         skb->dev->last_rx = jiffies;
 193
 194         stats = vlan_dev_get_stats(skb->dev);
 195         stats->rx_packets++;
 196         stats->rx_bytes += skb->len;
 197
 198         skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
 199         switch (skb->pkt_type) {
 200         case PACKET_BROADCAST:
 201                 break;
 202
 203         case PACKET_MULTICAST:
 204                 stats->multicast++;
 205                 break;
 206
 207         case PACKET_OTHERHOST:
 208                 /* Our lower layer thinks this is not local, let's make sure.
 209                  * This allows the VLAN to have a different MAC than the underlying
 210                  * device, and still route correctly.
 211                  */
 212                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
 213                                         skb->dev->dev_addr))
 214                         skb->pkt_type = PACKET_HOST;
 215                 break;
 216         };
 217
 218         return (polling ? netif_receive_skb(skb) : netif_rx(skb));
 219 }
 220
 221 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 222                                   struct vlan_group *grp,
 223                                   unsigned short vlan_tag)
 224 {
 225         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
 226 }
 227
 228 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 229                                            struct vlan_group *grp,
 230                                            unsigned short vlan_tag)
 231 {
 232         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
 233 }
 234
 235 /**
 236  * __vlan_put_tag - regular VLAN tag inserting
 237  * @skb: skbuff to tag
 238  * @tag: VLAN tag to insert
 239  *
 240  * Inserts the VLAN tag into @skb as part of the payload
 241  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 242  *
 243  * Following the skb_unshare() example, in case of error, the calling function
 244  * doesn't have to worry about freeing the original skb.
 245  */
 246 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 247 {
 248         struct vlan_ethhdr *veth;
 249
 250         if (skb_headroom(skb) < VLAN_HLEN) {
 251                 struct sk_buff *sk_tmp = skb;
 252                 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
 253                 kfree_skb(sk_tmp);
 254                 if (!skb) {
 255                         printk(KERN_ERR "vlan: failed to realloc headroom\n");
 256                         return NULL;
 257                 }
 258         } else {
 259                 skb = skb_unshare(skb, GFP_ATOMIC);
 260                 if (!skb) {
 261                         printk(KERN_ERR "vlan: failed to unshare skbuff\n");
 262                         return NULL;
 263                 }
 264         }
 265
 266         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 267
 268         /* Move the mac addresses to the beginning of the new header. */
 269         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 270
 271         /* first, the ethernet type */
 272         veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
 273
 274         /* now, the tag */
 275         veth->h_vlan_TCI = htons(tag);
 276
 277         skb->protocol = __constant_htons(ETH_P_8021Q);
 278         skb->mac_header -= VLAN_HLEN;
 279         skb->network_header -= VLAN_HLEN;
 280
 281         return skb;
 282 }
 283
 284 /**
 285  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 286  * @skb: skbuff to tag
 287  * @tag: VLAN tag to insert
 288  *
 289  * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
 290  */
 291 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
 292 {
 293         struct vlan_skb_tx_cookie *cookie;
 294
 295         cookie = VLAN_TX_SKB_CB(skb);
 296         cookie->magic = VLAN_TX_COOKIE_MAGIC;
 297         cookie->vlan_tag = tag;
 298
 299         return skb;
 300 }
 301
 302 #define HAVE_VLAN_PUT_TAG
 303
 304 /**
 305  * vlan_put_tag - inserts VLAN tag according to device features
 306  * @skb: skbuff to tag
 307  * @tag: VLAN tag to insert
 308  *
 309  * Assumes skb->dev is the target that will xmit this frame.
 310  * Returns a VLAN tagged skb.
 311  */
 312 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 313 {
 314         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 315                 return __vlan_hwaccel_put_tag(skb, tag);
 316         } else {
 317                 return __vlan_put_tag(skb, tag);
 318         }
 319 }
 320
 321 /**
 322  * __vlan_get_tag - get the VLAN ID that is part of the payload
 323  * @skb: skbuff to query
 324  * @tag: buffer to store vlaue
 325  *
 326  * Returns error if the skb is not of VLAN type
 327  */
 328 static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 329 {
 330         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 331
 332         if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
 333                 return -EINVAL;
 334         }
 335
 336         *tag = ntohs(veth->h_vlan_TCI);
 337
 338         return 0;
 339 }
 340
 341 /**
 342  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 343  * @skb: skbuff to query
 344  * @tag: buffer to store vlaue
 345  *
 346  * Returns error if @skb->cb[] is not set correctly
 347  */
 348 static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
 349 {
 350         struct vlan_skb_tx_cookie *cookie;
 351
 352         cookie = VLAN_TX_SKB_CB(skb);
 353         if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
 354                 *tag = cookie->vlan_tag;
 355                 return 0;
 356         } else {
 357                 *tag = 0;
 358                 return -EINVAL;
 359         }
 360 }
 361
 362 #define HAVE_VLAN_GET_TAG
 363
 364 /**
 365  * vlan_get_tag - get the VLAN ID from the skb
 366  * @skb: skbuff to query
 367  * @tag: buffer to store vlaue
 368  *
 369  * Returns error if the skb is not VLAN tagged
 370  */
 371 static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 372 {
 373         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 374                 return __vlan_hwaccel_get_tag(skb, tag);
 375         } else {
 376                 return __vlan_get_tag(skb, tag);
 377         }
 378 }
 379
 380 #endif /* __KERNEL__ */
 381
 382 /* VLAN IOCTLs are found in sockios.h */
 383
 384 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 385 enum vlan_ioctl_cmds {
 386         ADD_VLAN_CMD,
 387         DEL_VLAN_CMD,
 388         SET_VLAN_INGRESS_PRIORITY_CMD,
 389         SET_VLAN_EGRESS_PRIORITY_CMD,
 390         GET_VLAN_INGRESS_PRIORITY_CMD,
 391         GET_VLAN_EGRESS_PRIORITY_CMD,
 392         SET_VLAN_NAME_TYPE_CMD,
 393         SET_VLAN_FLAG_CMD,
 394         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 395         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 396 };
 397
 398 enum vlan_name_types {
 399         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 400         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 401         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 402         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 403         VLAN_NAME_TYPE_HIGHEST
 404 };
 405
 406 struct vlan_ioctl_args {
 407         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 408         char device1[24];
 409
 410         union {
 411                 char device2[24];
 412                 int VID;
 413                 unsigned int skb_priority;
 414                 unsigned int name_type;
 415                 unsigned int bind_type;
 416                 unsigned int flag; /* Matches vlan_dev_info flags */
 417         } u;
 418
 419         short vlan_qos;
 420 };
 421
 422 #endif /* !(_LINUX_IF_VLAN_H_) */