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 #ifndef _LINUX_IF_VLAN_H_
  13 #define _LINUX_IF_VLAN_H_
  14
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/bug.h>
  19 #include <uapi/linux/if_vlan.h>
  20
  21 #define VLAN_HLEN       4               /* The additional bytes required by VLAN
  22                                          * (in addition to the Ethernet header)
  23                                          */
  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
  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 static inline bool is_vlan_dev(struct net_device *dev)
  77 {
  78         return dev->priv_flags & IFF_802_1Q_VLAN;
  79 }
  80
  81 #define vlan_tx_tag_present(__skb)      ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  82 #define vlan_tx_tag_get(__skb)          ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  83 #define vlan_tx_tag_get_id(__skb)       ((__skb)->vlan_tci & VLAN_VID_MASK)
  84
  85 /**
  86  *      struct vlan_pcpu_stats - VLAN percpu rx/tx stats
  87  *      @rx_packets: number of received packets
  88  *      @rx_bytes: number of received bytes
  89  *      @rx_multicast: number of received multicast packets
  90  *      @tx_packets: number of transmitted packets
  91  *      @tx_bytes: number of transmitted bytes
  92  *      @syncp: synchronization point for 64bit counters
  93  *      @rx_errors: number of rx errors
  94  *      @tx_dropped: number of tx drops
  95  */
  96 struct vlan_pcpu_stats {
  97         u64                     rx_packets;
  98         u64                     rx_bytes;
  99         u64                     rx_multicast;
 100         u64                     tx_packets;
 101         u64                     tx_bytes;
 102         struct u64_stats_sync   syncp;
 103         u32                     rx_errors;
 104         u32                     tx_dropped;
 105 };
 106
 107 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 108
 109 extern struct net_device *__vlan_find_dev_deep_rcu(struct net_device *real_dev,
 110                                                __be16 vlan_proto, u16 vlan_id);
 111 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 112 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 113 extern __be16 vlan_dev_vlan_proto(const struct net_device *dev);
 114
 115 /**
 116  *      struct vlan_priority_tci_mapping - vlan egress priority mappings
 117  *      @priority: skb priority
 118  *      @vlan_qos: vlan priority: (skb->priority << 13) & 0xE000
 119  *      @next: pointer to next struct
 120  */
 121 struct vlan_priority_tci_mapping {
 122         u32                                     priority;
 123         u16                                     vlan_qos;
 124         struct vlan_priority_tci_mapping        *next;
 125 };
 126
 127 struct proc_dir_entry;
 128 struct netpoll;
 129
 130 /**
 131  *      struct vlan_dev_priv - VLAN private device data
 132  *      @nr_ingress_mappings: number of ingress priority mappings
 133  *      @ingress_priority_map: ingress priority mappings
 134  *      @nr_egress_mappings: number of egress priority mappings
 135  *      @egress_priority_map: hash of egress priority mappings
 136  *      @vlan_proto: VLAN encapsulation protocol
 137  *      @vlan_id: VLAN identifier
 138  *      @flags: device flags
 139  *      @real_dev: underlying netdevice
 140  *      @real_dev_addr: address of underlying netdevice
 141  *      @dent: proc dir entry
 142  *      @vlan_pcpu_stats: ptr to percpu rx stats
 143  */
 144 struct vlan_dev_priv {
 145         unsigned int                            nr_ingress_mappings;
 146         u32                                     ingress_priority_map[8];
 147         unsigned int                            nr_egress_mappings;
 148         struct vlan_priority_tci_mapping        *egress_priority_map[16];
 149
 150         __be16                                  vlan_proto;
 151         u16                                     vlan_id;
 152         u16                                     flags;
 153
 154         struct net_device                       *real_dev;
 155         unsigned char                           real_dev_addr[ETH_ALEN];
 156
 157         struct proc_dir_entry                   *dent;
 158         struct vlan_pcpu_stats __percpu         *vlan_pcpu_stats;
 159 #ifdef CONFIG_NET_POLL_CONTROLLER
 160         struct netpoll                          *netpoll;
 161 #endif
 162         unsigned int                            nest_level;
 163 };
 164
 165 static inline struct vlan_dev_priv *vlan_dev_priv(const struct net_device *dev)
 166 {
 167         return netdev_priv(dev);
 168 }
 169
 170 static inline u16
 171 vlan_dev_get_egress_qos_mask(struct net_device *dev, u32 skprio)
 172 {
 173         struct vlan_priority_tci_mapping *mp;
 174
 175         smp_rmb(); /* coupled with smp_wmb() in vlan_dev_set_egress_priority() */
 176
 177         mp = vlan_dev_priv(dev)->egress_priority_map[(skprio & 0xF)];
 178         while (mp) {
 179                 if (mp->priority == skprio) {
 180                         return mp->vlan_qos; /* This should already be shifted
 181                                               * to mask correctly with the
 182                                               * VLAN's TCI */
 183                 }
 184                 mp = mp->next;
 185         }
 186         return 0;
 187 }
 188
 189 extern bool vlan_do_receive(struct sk_buff **skb);
 190 extern struct sk_buff *vlan_untag(struct sk_buff *skb);
 191
 192 extern int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid);
 193 extern void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid);
 194
 195 extern int vlan_vids_add_by_dev(struct net_device *dev,
 196                                 const struct net_device *by_dev);
 197 extern void vlan_vids_del_by_dev(struct net_device *dev,
 198                                  const struct net_device *by_dev);
 199
 200 extern bool vlan_uses_dev(const struct net_device *dev);
 201
 202 static inline int vlan_get_encap_level(struct net_device *dev)
 203 {
 204         BUG_ON(!is_vlan_dev(dev));
 205         return vlan_dev_priv(dev)->nest_level;
 206 }
 207 #else
 208 static inline struct net_device *
 209 __vlan_find_dev_deep_rcu(struct net_device *real_dev,
 210                      __be16 vlan_proto, u16 vlan_id)
 211 {
 212         return NULL;
 213 }
 214
 215 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 216 {
 217         BUG();
 218         return NULL;
 219 }
 220
 221 static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
 222 {
 223         BUG();
 224         return 0;
 225 }
 226
 227 static inline __be16 vlan_dev_vlan_proto(const struct net_device *dev)
 228 {
 229         BUG();
 230         return 0;
 231 }
 232
 233 static inline u16 vlan_dev_get_egress_qos_mask(struct net_device *dev,
 234                                                u32 skprio)
 235 {
 236         return 0;
 237 }
 238
 239 static inline bool vlan_do_receive(struct sk_buff **skb)
 240 {
 241         return false;
 242 }
 243
 244 static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
 245 {
 246         return skb;
 247 }
 248
 249 static inline int vlan_vid_add(struct net_device *dev, __be16 proto, u16 vid)
 250 {
 251         return 0;
 252 }
 253
 254 static inline void vlan_vid_del(struct net_device *dev, __be16 proto, u16 vid)
 255 {
 256 }
 257
 258 static inline int vlan_vids_add_by_dev(struct net_device *dev,
 259                                        const struct net_device *by_dev)
 260 {
 261         return 0;
 262 }
 263
 264 static inline void vlan_vids_del_by_dev(struct net_device *dev,
 265                                         const struct net_device *by_dev)
 266 {
 267 }
 268
 269 static inline bool vlan_uses_dev(const struct net_device *dev)
 270 {
 271         return false;
 272 }
 273 static inline int vlan_get_encap_level(struct net_device *dev)
 274 {
 275         BUG();
 276         return 0;
 277 }
 278 #endif
 279
 280 static inline bool vlan_hw_offload_capable(netdev_features_t features,
 281                                            __be16 proto)
 282 {
 283         if (proto == htons(ETH_P_8021Q) && features & NETIF_F_HW_VLAN_CTAG_TX)
 284                 return true;
 285         if (proto == htons(ETH_P_8021AD) && features & NETIF_F_HW_VLAN_STAG_TX)
 286                 return true;
 287         return false;
 288 }
 289
 290 /**
 291  * vlan_insert_tag - regular VLAN tag inserting
 292  * @skb: skbuff to tag
 293  * @vlan_proto: VLAN encapsulation protocol
 294  * @vlan_tci: VLAN TCI to insert
 295  *
 296  * Inserts the VLAN tag into @skb as part of the payload
 297  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 298  *
 299  * Following the skb_unshare() example, in case of error, the calling function
 300  * doesn't have to worry about freeing the original skb.
 301  *
 302  * Does not change skb->protocol so this function can be used during receive.
 303  */
 304 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb,
 305                                               __be16 vlan_proto, u16 vlan_tci)
 306 {
 307         struct vlan_ethhdr *veth;
 308
 309         if (skb_cow_head(skb, VLAN_HLEN) < 0) {
 310                 dev_kfree_skb_any(skb);
 311                 return NULL;
 312         }
 313         veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
 314
 315         /* Move the mac addresses to the beginning of the new header. */
 316         memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN);
 317         skb->mac_header -= VLAN_HLEN;
 318
 319         /* first, the ethernet type */
 320         veth->h_vlan_proto = vlan_proto;
 321
 322         /* now, the TCI */
 323         veth->h_vlan_TCI = htons(vlan_tci);
 324
 325         return skb;
 326 }
 327
 328 /**
 329  * __vlan_put_tag - regular VLAN tag inserting
 330  * @skb: skbuff to tag
 331  * @vlan_tci: VLAN TCI to insert
 332  *
 333  * Inserts the VLAN tag into @skb as part of the payload
 334  * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
 335  *
 336  * Following the skb_unshare() example, in case of error, the calling function
 337  * doesn't have to worry about freeing the original skb.
 338  */
 339 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb,
 340                                              __be16 vlan_proto, u16 vlan_tci)
 341 {
 342         skb = vlan_insert_tag(skb, vlan_proto, vlan_tci);
 343         if (skb)
 344                 skb->protocol = vlan_proto;
 345         return skb;
 346 }
 347
 348 /**
 349  * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
 350  * @skb: skbuff to tag
 351  * @vlan_proto: VLAN encapsulation protocol
 352  * @vlan_tci: VLAN TCI to insert
 353  *
 354  * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
 355  */
 356 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
 357                                                      __be16 vlan_proto,
 358                                                      u16 vlan_tci)
 359 {
 360         skb->vlan_proto = vlan_proto;
 361         skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
 362         return skb;
 363 }
 364
 365 /**
 366  * vlan_put_tag - inserts VLAN tag according to device features
 367  * @skb: skbuff to tag
 368  * @vlan_tci: VLAN TCI to insert
 369  *
 370  * Assumes skb->dev is the target that will xmit this frame.
 371  * Returns a VLAN tagged skb.
 372  */
 373 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb,
 374                                            __be16 vlan_proto, u16 vlan_tci)
 375 {
 376         if (vlan_hw_offload_capable(skb->dev->features, vlan_proto)) {
 377                 return __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
 378         } else {
 379                 return __vlan_put_tag(skb, vlan_proto, vlan_tci);
 380         }
 381 }
 382
 383 /**
 384  * __vlan_get_tag - get the VLAN ID that is part of the payload
 385  * @skb: skbuff to query
 386  * @vlan_tci: buffer to store vlaue
 387  *
 388  * Returns error if the skb is not of VLAN type
 389  */
 390 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 391 {
 392         struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
 393
 394         if (veth->h_vlan_proto != htons(ETH_P_8021Q) &&
 395             veth->h_vlan_proto != htons(ETH_P_8021AD))
 396                 return -EINVAL;
 397
 398         *vlan_tci = ntohs(veth->h_vlan_TCI);
 399         return 0;
 400 }
 401
 402 /**
 403  * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
 404  * @skb: skbuff to query
 405  * @vlan_tci: buffer to store vlaue
 406  *
 407  * Returns error if @skb->vlan_tci is not set correctly
 408  */
 409 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 410                                          u16 *vlan_tci)
 411 {
 412         if (vlan_tx_tag_present(skb)) {
 413                 *vlan_tci = vlan_tx_tag_get(skb);
 414                 return 0;
 415         } else {
 416                 *vlan_tci = 0;
 417                 return -EINVAL;
 418         }
 419 }
 420
 421 #define HAVE_VLAN_GET_TAG
 422
 423 /**
 424  * vlan_get_tag - get the VLAN ID from the skb
 425  * @skb: skbuff to query
 426  * @vlan_tci: buffer to store vlaue
 427  *
 428  * Returns error if the skb is not VLAN tagged
 429  */
 430 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
 431 {
 432         if (skb->dev->features & NETIF_F_HW_VLAN_CTAG_TX) {
 433                 return __vlan_hwaccel_get_tag(skb, vlan_tci);
 434         } else {
 435                 return __vlan_get_tag(skb, vlan_tci);
 436         }
 437 }
 438
 439 /**
 440  * vlan_get_protocol - get protocol EtherType.
 441  * @skb: skbuff to query
 442  *
 443  * Returns the EtherType of the packet, regardless of whether it is
 444  * vlan encapsulated (normal or hardware accelerated) or not.
 445  */
 446 static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
 447 {
 448         __be16 protocol = 0;
 449
 450         if (vlan_tx_tag_present(skb) ||
 451              skb->protocol != cpu_to_be16(ETH_P_8021Q))
 452                 protocol = skb->protocol;
 453         else {
 454                 __be16 proto, *protop;
 455                 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
 456                                                 h_vlan_encapsulated_proto),
 457                                                 sizeof(proto), &proto);
 458                 if (likely(protop))
 459                         protocol = *protop;
 460         }
 461
 462         return protocol;
 463 }
 464
 465 static inline void vlan_set_encap_proto(struct sk_buff *skb,
 466                                         struct vlan_hdr *vhdr)
 467 {
 468         __be16 proto;
 469         unsigned short *rawp;
 470
 471         /*
 472          * Was a VLAN packet, grab the encapsulated protocol, which the layer
 473          * three protocols care about.
 474          */
 475
 476         proto = vhdr->h_vlan_encapsulated_proto;
 477         if (ntohs(proto) >= ETH_P_802_3_MIN) {
 478                 skb->protocol = proto;
 479                 return;
 480         }
 481
 482         rawp = (unsigned short *)(vhdr + 1);
 483         if (*rawp == 0xFFFF)
 484                 /*
 485                  * This is a magic hack to spot IPX packets. Older Novell
 486                  * breaks the protocol design and runs IPX over 802.3 without
 487                  * an 802.2 LLC layer. We look for FFFF which isn't a used
 488                  * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
 489                  * but does for the rest.
 490                  */
 491                 skb->protocol = htons(ETH_P_802_3);
 492         else
 493                 /*
 494                  * Real 802.2 LLC
 495                  */
 496                 skb->protocol = htons(ETH_P_802_2);
 497 }
 498
 499 #endif /* !(_LINUX_IF_VLAN_H_) */