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