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_) */ 424