1 /* 2 * VLAN An implementation of 802.1Q VLAN tagging. 3 * 4 * Authors: Ben Greear <[email protected]> 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 hlist_node; 20 21 #include <linux/netdevice.h> 22 #include <linux/etherdevice.h> 23 24 #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header) 25 * that VLAN requires. 26 */ 27 #define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */ 28 #define VLAN_ETH_HLEN 18 /* Total octets in header. */ 29 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */ 30 31 /* 32 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan 33 */ 34 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */ 35 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */ 36 37 /* 38 * struct vlan_hdr - vlan header 39 * @h_vlan_TCI: priority and VLAN ID 40 * @h_vlan_encapsulated_proto: packet type ID or len 41 */ 42 struct vlan_hdr { 43 __be16 h_vlan_TCI; 44 __be16 h_vlan_encapsulated_proto; 45 }; 46 47 /** 48 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr) 49 * @h_dest: destination ethernet address 50 * @h_source: source ethernet address 51 * @h_vlan_proto: ethernet protocol (always 0x8100) 52 * @h_vlan_TCI: priority and VLAN ID 53 * @h_vlan_encapsulated_proto: packet type ID or len 54 */ 55 struct vlan_ethhdr { 56 unsigned char h_dest[ETH_ALEN]; 57 unsigned char h_source[ETH_ALEN]; 58 __be16 h_vlan_proto; 59 __be16 h_vlan_TCI; 60 __be16 h_vlan_encapsulated_proto; 61 }; 62 63 #include <linux/skbuff.h> 64 65 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) 66 { 67 return (struct vlan_ethhdr *)skb_mac_header(skb); 68 } 69 70 #define VLAN_VID_MASK 0xfff 71 72 /* found in socket.c */ 73 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); 74 75 /* if this changes, algorithm will have to be reworked because this 76 * depends on completely exhausting the VLAN identifier space. Thus 77 * it gives constant time look-up, but in many cases it wastes memory. 78 */ 79 #define VLAN_GROUP_ARRAY_LEN 4096 80 #define VLAN_GROUP_ARRAY_SPLIT_PARTS 8 81 #define VLAN_GROUP_ARRAY_PART_LEN (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS) 82 83 struct vlan_group { 84 int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */ 85 unsigned int nr_vlans; 86 struct hlist_node hlist; /* linked list */ 87 struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS]; 88 struct rcu_head rcu; 89 }; 90 91 static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, 92 unsigned int vlan_id) 93 { 94 struct net_device **array; 95 array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN]; 96 return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN]; 97 } 98 99 static inline void vlan_group_set_device(struct vlan_group *vg, 100 unsigned int vlan_id, 101 struct net_device *dev) 102 { 103 struct net_device **array; 104 if (!vg) 105 return; 106 array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN]; 107 array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev; 108 } 109 110 struct vlan_priority_tci_mapping { 111 u32 priority; 112 unsigned short vlan_qos; /* This should be shifted when first set, so we only do it 113 * at provisioning time. 114 * ((skb->priority << 13) & 0xE000) 115 */ 116 struct vlan_priority_tci_mapping *next; 117 }; 118 119 /* Holds information that makes sense if this device is a VLAN device. */ 120 struct vlan_dev_info { 121 /** This will be the mapping that correlates skb->priority to 122 * 3 bits of VLAN QOS tags... 123 */ 124 unsigned int nr_ingress_mappings; 125 u32 ingress_priority_map[8]; 126 127 unsigned int nr_egress_mappings; 128 struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */ 129 130 unsigned short vlan_id; /* The VLAN Identifier for this interface. */ 131 unsigned short flags; /* (1 << 0) re_order_header This option will cause the 132 * VLAN code to move around the ethernet header on 133 * ingress to make the skb look **exactly** like it 134 * came in from an ethernet port. This destroys some of 135 * the VLAN information in the skb, but it fixes programs 136 * like DHCP that use packet-filtering and don't understand 137 * 802.1Q 138 */ 139 struct net_device *real_dev; /* the underlying device/interface */ 140 unsigned char real_dev_addr[ETH_ALEN]; 141 struct proc_dir_entry *dent; /* Holds the proc data */ 142 unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */ 143 unsigned long cnt_encap_on_xmit; /* How many times did we have to encapsulate the skb on TX. */ 144 }; 145 146 static inline struct vlan_dev_info *vlan_dev_info(const struct net_device *dev) 147 { 148 return netdev_priv(dev); 149 } 150 151 /* inline functions */ 152 static inline __u32 vlan_get_ingress_priority(struct net_device *dev, 153 unsigned short vlan_tag) 154 { 155 struct vlan_dev_info *vip = vlan_dev_info(dev); 156 157 return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7]; 158 } 159 160 /* VLAN tx hw acceleration helpers. */ 161 struct vlan_skb_tx_cookie { 162 u32 magic; 163 u32 vlan_tag; 164 }; 165 166 #define VLAN_TX_COOKIE_MAGIC 0x564c414e /* "VLAN" in ascii. */ 167 #define VLAN_TX_SKB_CB(__skb) ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0])) 168 #define vlan_tx_tag_present(__skb) \ 169 (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC) 170 #define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag) 171 172 /* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */ 173 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, 174 struct vlan_group *grp, 175 unsigned short vlan_tag, int polling) 176 { 177 struct net_device_stats *stats; 178 179 if (skb_bond_should_drop(skb)) { 180 dev_kfree_skb_any(skb); 181 return NET_RX_DROP; 182 } 183 184 skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK); 185 if (skb->dev == NULL) { 186 dev_kfree_skb_any(skb); 187 188 /* Not NET_RX_DROP, this is not being dropped 189 * due to congestion. 190 */ 191 return 0; 192 } 193 194 skb->dev->last_rx = jiffies; 195 196 stats = &skb->dev->stats; 197 stats->rx_packets++; 198 stats->rx_bytes += skb->len; 199 200 skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag); 201 switch (skb->pkt_type) { 202 case PACKET_BROADCAST: 203 break; 204 205 case PACKET_MULTICAST: 206 stats->multicast++; 207 break; 208 209 case PACKET_OTHERHOST: 210 /* Our lower layer thinks this is not local, let's make sure. 211 * This allows the VLAN to have a different MAC than the underlying 212 * device, and still route correctly. 213 */ 214 if (!compare_ether_addr(eth_hdr(skb)->h_dest, 215 skb->dev->dev_addr)) 216 skb->pkt_type = PACKET_HOST; 217 break; 218 }; 219 220 return (polling ? netif_receive_skb(skb) : netif_rx(skb)); 221 } 222 223 static inline int vlan_hwaccel_rx(struct sk_buff *skb, 224 struct vlan_group *grp, 225 unsigned short vlan_tag) 226 { 227 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0); 228 } 229 230 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb, 231 struct vlan_group *grp, 232 unsigned short vlan_tag) 233 { 234 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1); 235 } 236 237 /** 238 * __vlan_put_tag - regular VLAN tag inserting 239 * @skb: skbuff to tag 240 * @tag: VLAN tag to insert 241 * 242 * Inserts the VLAN tag into @skb as part of the payload 243 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 244 * 245 * Following the skb_unshare() example, in case of error, the calling function 246 * doesn't have to worry about freeing the original skb. 247 */ 248 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag) 249 { 250 struct vlan_ethhdr *veth; 251 252 if (skb_headroom(skb) < VLAN_HLEN) { 253 struct sk_buff *sk_tmp = skb; 254 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN); 255 kfree_skb(sk_tmp); 256 if (!skb) { 257 printk(KERN_ERR "vlan: failed to realloc headroom\n"); 258 return NULL; 259 } 260 } else { 261 skb = skb_unshare(skb, GFP_ATOMIC); 262 if (!skb) { 263 printk(KERN_ERR "vlan: failed to unshare skbuff\n"); 264 return NULL; 265 } 266 } 267 268 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); 269 270 /* Move the mac addresses to the beginning of the new header. */ 271 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN); 272 273 /* first, the ethernet type */ 274 veth->h_vlan_proto = htons(ETH_P_8021Q); 275 276 /* now, the tag */ 277 veth->h_vlan_TCI = htons(tag); 278 279 skb->protocol = htons(ETH_P_8021Q); 280 skb->mac_header -= VLAN_HLEN; 281 skb->network_header -= VLAN_HLEN; 282 283 return skb; 284 } 285 286 /** 287 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 288 * @skb: skbuff to tag 289 * @tag: VLAN tag to insert 290 * 291 * Puts the VLAN tag in @skb->cb[] and lets the device do the rest 292 */ 293 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag) 294 { 295 struct vlan_skb_tx_cookie *cookie; 296 297 cookie = VLAN_TX_SKB_CB(skb); 298 cookie->magic = VLAN_TX_COOKIE_MAGIC; 299 cookie->vlan_tag = tag; 300 301 return skb; 302 } 303 304 #define HAVE_VLAN_PUT_TAG 305 306 /** 307 * vlan_put_tag - inserts VLAN tag according to device features 308 * @skb: skbuff to tag 309 * @tag: VLAN tag to insert 310 * 311 * Assumes skb->dev is the target that will xmit this frame. 312 * Returns a VLAN tagged skb. 313 */ 314 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag) 315 { 316 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 317 return __vlan_hwaccel_put_tag(skb, tag); 318 } else { 319 return __vlan_put_tag(skb, tag); 320 } 321 } 322 323 /** 324 * __vlan_get_tag - get the VLAN ID that is part of the payload 325 * @skb: skbuff to query 326 * @tag: buffer to store vlaue 327 * 328 * Returns error if the skb is not of VLAN type 329 */ 330 static inline int __vlan_get_tag(const struct sk_buff *skb, unsigned short *tag) 331 { 332 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 333 334 if (veth->h_vlan_proto != htons(ETH_P_8021Q)) { 335 return -EINVAL; 336 } 337 338 *tag = ntohs(veth->h_vlan_TCI); 339 340 return 0; 341 } 342 343 /** 344 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 345 * @skb: skbuff to query 346 * @tag: buffer to store vlaue 347 * 348 * Returns error if @skb->cb[] is not set correctly 349 */ 350 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 351 unsigned short *tag) 352 { 353 struct vlan_skb_tx_cookie *cookie; 354 355 cookie = VLAN_TX_SKB_CB(skb); 356 if (cookie->magic == VLAN_TX_COOKIE_MAGIC) { 357 *tag = cookie->vlan_tag; 358 return 0; 359 } else { 360 *tag = 0; 361 return -EINVAL; 362 } 363 } 364 365 #define HAVE_VLAN_GET_TAG 366 367 /** 368 * vlan_get_tag - get the VLAN ID from the skb 369 * @skb: skbuff to query 370 * @tag: buffer to store vlaue 371 * 372 * Returns error if the skb is not VLAN tagged 373 */ 374 static inline int vlan_get_tag(const struct sk_buff *skb, unsigned short *tag) 375 { 376 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 377 return __vlan_hwaccel_get_tag(skb, tag); 378 } else { 379 return __vlan_get_tag(skb, tag); 380 } 381 } 382 383 #endif /* __KERNEL__ */ 384 385 /* VLAN IOCTLs are found in sockios.h */ 386 387 /* Passed in vlan_ioctl_args structure to determine behaviour. */ 388 enum vlan_ioctl_cmds { 389 ADD_VLAN_CMD, 390 DEL_VLAN_CMD, 391 SET_VLAN_INGRESS_PRIORITY_CMD, 392 SET_VLAN_EGRESS_PRIORITY_CMD, 393 GET_VLAN_INGRESS_PRIORITY_CMD, 394 GET_VLAN_EGRESS_PRIORITY_CMD, 395 SET_VLAN_NAME_TYPE_CMD, 396 SET_VLAN_FLAG_CMD, 397 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */ 398 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */ 399 }; 400 401 enum vlan_flags { 402 VLAN_FLAG_REORDER_HDR = 0x1, 403 }; 404 405 enum vlan_name_types { 406 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */ 407 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */ 408 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */ 409 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */ 410 VLAN_NAME_TYPE_HIGHEST 411 }; 412 413 struct vlan_ioctl_args { 414 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */ 415 char device1[24]; 416 417 union { 418 char device2[24]; 419 int VID; 420 unsigned int skb_priority; 421 unsigned int name_type; 422 unsigned int bind_type; 423 unsigned int flag; /* Matches vlan_dev_info flags */ 424 } u; 425 426 short vlan_qos; 427 }; 428 429 #endif /* !(_LINUX_IF_VLAN_H_) */ 430