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)(struct net *, 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         u32 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 int nr_ingress_mappings;
 116         u32 ingress_priority_map[8];
 117
 118         unsigned int nr_egress_mappings;
 119         struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */
 120
 121         unsigned short vlan_id;        /*  The VLAN Identifier for this interface. */
 122         unsigned short flags;          /* (1 << 0) re_order_header   This option will cause the
 123                                         *   VLAN code to move around the ethernet header on
 124                                         *   ingress to make the skb look **exactly** like it
 125                                         *   came in from an ethernet port.  This destroys some of
 126                                         *   the VLAN information in the skb, but it fixes programs
 127                                         *   like DHCP that use packet-filtering and don't understand
 128                                         *   802.1Q
 129                                         */
 130         struct net_device *real_dev;    /* the underlying device/interface */
 131         unsigned char real_dev_addr[ETH_ALEN];
 132         struct proc_dir_entry *dent;    /* Holds the proc data */
 133         unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
 134         unsigned long cnt_encap_on_xmit;      /* How many times did we have to encapsulate the skb on TX. */
 135         struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
 136 };
 137
 138 #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
 139
 140 /* inline functions */
 141
 142 static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
 143 {
 144         return &(VLAN_DEV_INFO(dev)->dev_stats);
 145 }
 146
 147 static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
 148                                               unsigned short vlan_tag)
 149 {
 150         struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
 151
 152         return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
 153 }
 154
 155 /* VLAN tx hw acceleration helpers. */
 156 struct vlan_skb_tx_cookie {
 157         u32     magic;
 158         u32     vlan_tag;
 159 };
 160
 161 #define VLAN_TX_COOKIE_MAGIC    0x564c414e      /* "VLAN" in ascii. */
 162 #define VLAN_TX_SKB_CB(__skb)   ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
 163 #define vlan_tx_tag_present(__skb) \
 164         (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
 165 #define vlan_tx_tag_get(__skb)  (VLAN_TX_SKB_CB(__skb)->vlan_tag)
 166
 167 /* VLAN rx hw acceleration helper.  This acts like netif_{rx,receive_skb}(). */
 168 static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
 169                                     struct vlan_group *grp,
 170                                     unsigned short vlan_tag, int polling)
 171 {
 172         struct net_device_stats *stats;
 173
 174         if (skb_bond_should_drop(skb)) {
 175                 dev_kfree_skb_any(skb);
 176                 return NET_RX_DROP;
 177         }
 178
 179         skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
 180         if (skb->dev == NULL) {
 181                 dev_kfree_skb_any(skb);
 182
 183                 /* Not NET_RX_DROP, this is not being dropped
 184                  * due to congestion.
 185                  */
 186                 return 0;
 187         }
 188
 189         skb->dev->last_rx = jiffies;
 190
 191         stats = vlan_dev_get_stats(skb->dev);
 192         stats->rx_packets++;
 193         stats->rx_bytes += skb->len;
 194
 195         skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
 196         switch (skb->pkt_type) {
 197         case PACKET_BROADCAST:
 198                 break;
 199
 200         case PACKET_MULTICAST:
 201                 stats->multicast++;
 202                 break;
 203
 204         case PACKET_OTHERHOST:
 205                 /* Our lower layer thinks this is not local, let's make sure.
 206                  * This allows the VLAN to have a different MAC than the underlying
 207                  * device, and still route correctly.
 208                  */
 209                 if (!compare_ether_addr(eth_hdr(skb)->h_dest,
 210                                         skb->dev->dev_addr))
 211                         skb->pkt_type = PACKET_HOST;
 212                 break;
 213         };
 214
 215         return (polling ? netif_receive_skb(skb) : netif_rx(skb));
 216 }
 217
 218 static inline int vlan_hwaccel_rx(struct sk_buff *skb,
 219                                   struct vlan_group *grp,
 220                                   unsigned short vlan_tag)
 221 {
 222         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
 223 }
 224
 225 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
 226                                            struct vlan_group *grp,
 227                                            unsigned short vlan_tag)
 228 {
 229         return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
 230 }
 231
 232 /**
 233  * __vlan_put_tag - regular VLAN tag inserting
 234  * @skb: skbuff to tag
 235  * @tag: VLAN tag to insert
 236  *
 237  * Inserts the VLAN tag into @skb as part of the payload
 238  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 239  *
 240  * Following the skb_unshare() example, in case of error, the calling function
 241  * doesn't have to worry about freeing the original skb.
 242  */
 243 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 244 {
 245         struct vlan_ethhdr *veth;
 246
 247         if (skb_headroom(skb) < VLAN_HLEN) {
 248                 struct sk_buff *sk_tmp = skb;
 249                 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
 250                 kfree_skb(sk_tmp);
 251                 if (!skb) {
 252                         printk(KERN_ERR "vlan: failed to realloc headroom\n");
 253                         return NULL;
 254                 }
 255         } else {
 256                 skb = skb_unshare(skb, GFP_ATOMIC);
 257                 if (!skb) {
 258                         printk(KERN_ERR "vlan: failed to unshare skbuff\n");
 259                         return NULL;
 260                 }
 261         }
 262
 263         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 264
 265         /* Move the mac addresses to the beginning of the new header. */
 266         memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
 267
 268         /* first, the ethernet type */
 269         veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
 270
 271         /* now, the tag */
 272         veth->h_vlan_TCI = htons(tag);
 273
 274         skb->protocol = __constant_htons(ETH_P_8021Q);
 275         skb->mac_header -= VLAN_HLEN;
 276         skb->network_header -= VLAN_HLEN;
 277
 278         return skb;
 279 }
 280
 281 /**
 282  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 283  * @skb: skbuff to tag
 284  * @tag: VLAN tag to insert
 285  *
 286  * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
 287  */
 288 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
 289 {
 290         struct vlan_skb_tx_cookie *cookie;
 291
 292         cookie = VLAN_TX_SKB_CB(skb);
 293         cookie->magic = VLAN_TX_COOKIE_MAGIC;
 294         cookie->vlan_tag = tag;
 295
 296         return skb;
 297 }
 298
 299 #define HAVE_VLAN_PUT_TAG
 300
 301 /**
 302  * vlan_put_tag - inserts VLAN tag according to device features
 303  * @skb: skbuff to tag
 304  * @tag: VLAN tag to insert
 305  *
 306  * Assumes skb->dev is the target that will xmit this frame.
 307  * Returns a VLAN tagged skb.
 308  */
 309 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
 310 {
 311         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 312                 return __vlan_hwaccel_put_tag(skb, tag);
 313         } else {
 314                 return __vlan_put_tag(skb, tag);
 315         }
 316 }
 317
 318 /**
 319  * __vlan_get_tag - get the VLAN ID that is part of the payload
 320  * @skb: skbuff to query
 321  * @tag: buffer to store vlaue
 322  *
 323  * Returns error if the skb is not of VLAN type
 324  */
 325 static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 326 {
 327         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 328
 329         if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
 330                 return -EINVAL;
 331         }
 332
 333         *tag = ntohs(veth->h_vlan_TCI);
 334
 335         return 0;
 336 }
 337
 338 /**
 339  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 340  * @skb: skbuff to query
 341  * @tag: buffer to store vlaue
 342  *
 343  * Returns error if @skb->cb[] is not set correctly
 344  */
 345 static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
 346 {
 347         struct vlan_skb_tx_cookie *cookie;
 348
 349         cookie = VLAN_TX_SKB_CB(skb);
 350         if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
 351                 *tag = cookie->vlan_tag;
 352                 return 0;
 353         } else {
 354                 *tag = 0;
 355                 return -EINVAL;
 356         }
 357 }
 358
 359 #define HAVE_VLAN_GET_TAG
 360
 361 /**
 362  * vlan_get_tag - get the VLAN ID from the skb
 363  * @skb: skbuff to query
 364  * @tag: buffer to store vlaue
 365  *
 366  * Returns error if the skb is not VLAN tagged
 367  */
 368 static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
 369 {
 370         if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
 371                 return __vlan_hwaccel_get_tag(skb, tag);
 372         } else {
 373                 return __vlan_get_tag(skb, tag);
 374         }
 375 }
 376
 377 #endif /* __KERNEL__ */
 378
 379 /* VLAN IOCTLs are found in sockios.h */
 380
 381 /* Passed in vlan_ioctl_args structure to determine behaviour. */
 382 enum vlan_ioctl_cmds {
 383         ADD_VLAN_CMD,
 384         DEL_VLAN_CMD,
 385         SET_VLAN_INGRESS_PRIORITY_CMD,
 386         SET_VLAN_EGRESS_PRIORITY_CMD,
 387         GET_VLAN_INGRESS_PRIORITY_CMD,
 388         GET_VLAN_EGRESS_PRIORITY_CMD,
 389         SET_VLAN_NAME_TYPE_CMD,
 390         SET_VLAN_FLAG_CMD,
 391         GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
 392         GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
 393 };
 394
 395 enum vlan_flags {
 396         VLAN_FLAG_REORDER_HDR   = 0x1,
 397 };
 398
 399 enum vlan_name_types {
 400         VLAN_NAME_TYPE_PLUS_VID, /* Name will look like:  vlan0005 */
 401         VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like:  eth1.0005 */
 402         VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like:  vlan5 */
 403         VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like:  eth0.5 */
 404         VLAN_NAME_TYPE_HIGHEST
 405 };
 406
 407 struct vlan_ioctl_args {
 408         int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
 409         char device1[24];
 410
 411         union {
 412                 char device2[24];
 413                 int VID;
 414                 unsigned int skb_priority;
 415                 unsigned int name_type;
 416                 unsigned int bind_type;
 417                 unsigned int flag; /* Matches vlan_dev_info flags */
 418         } u;
 419
 420         short vlan_qos;
 421 };
 422
 423 #endif /* !(_LINUX_IF_VLAN_H_) */