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