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/proc_fs.h> /* for proc_dir_entry */ 27 #include <linux/netdevice.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 unsigned short h_vlan_proto; /* Should always be 0x8100 */ 46 unsigned short h_vlan_TCI; /* Encapsulates priority and VLAN ID */ 47 unsigned short 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 unsigned short h_vlan_TCI; /* Encapsulates priority and VLAN ID */ 59 unsigned short 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 75 struct vlan_group { 76 int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */ 77 struct hlist_node hlist; /* linked list */ 78 struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN]; 79 struct rcu_head rcu; 80 }; 81 82 struct vlan_priority_tci_mapping { 83 unsigned long priority; 84 unsigned short vlan_qos; /* This should be shifted when first set, so we only do it 85 * at provisioning time. 86 * ((skb->priority << 13) & 0xE000) 87 */ 88 struct vlan_priority_tci_mapping *next; 89 }; 90 91 /* Holds information that makes sense if this device is a VLAN device. */ 92 struct vlan_dev_info { 93 /** This will be the mapping that correlates skb->priority to 94 * 3 bits of VLAN QOS tags... 95 */ 96 unsigned long ingress_priority_map[8]; 97 struct vlan_priority_tci_mapping *egress_priority_map[16]; /* hash table */ 98 99 unsigned short vlan_id; /* The VLAN Identifier for this interface. */ 100 unsigned short flags; /* (1 << 0) re_order_header This option will cause the 101 * VLAN code to move around the ethernet header on 102 * ingress to make the skb look **exactly** like it 103 * came in from an ethernet port. This destroys some of 104 * the VLAN information in the skb, but it fixes programs 105 * like DHCP that use packet-filtering and don't understand 106 * 802.1Q 107 */ 108 struct dev_mc_list *old_mc_list; /* old multi-cast list for the VLAN interface.. 109 * we save this so we can tell what changes were 110 * made, in order to feed the right changes down 111 * to the real hardware... 112 */ 113 int old_allmulti; /* similar to above. */ 114 int old_promiscuity; /* similar to above. */ 115 struct net_device *real_dev; /* the underlying device/interface */ 116 struct proc_dir_entry *dent; /* Holds the proc data */ 117 unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */ 118 unsigned long cnt_encap_on_xmit; /* How many times did we have to encapsulate the skb on TX. */ 119 struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */ 120 }; 121 122 #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv)) 123 124 /* inline functions */ 125 126 static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev) 127 { 128 return &(VLAN_DEV_INFO(dev)->dev_stats); 129 } 130 131 static inline __u32 vlan_get_ingress_priority(struct net_device *dev, 132 unsigned short vlan_tag) 133 { 134 struct vlan_dev_info *vip = VLAN_DEV_INFO(dev); 135 136 return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7]; 137 } 138 139 /* VLAN tx hw acceleration helpers. */ 140 struct vlan_skb_tx_cookie { 141 u32 magic; 142 u32 vlan_tag; 143 }; 144 145 #define VLAN_TX_COOKIE_MAGIC 0x564c414e /* "VLAN" in ascii. */ 146 #define VLAN_TX_SKB_CB(__skb) ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0])) 147 #define vlan_tx_tag_present(__skb) \ 148 (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC) 149 #define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag) 150 151 /* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */ 152 static inline int __vlan_hwaccel_rx(struct sk_buff *skb, 153 struct vlan_group *grp, 154 unsigned short vlan_tag, int polling) 155 { 156 struct net_device_stats *stats; 157 158 skb->real_dev = skb->dev; 159 skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK]; 160 if (skb->dev == NULL) { 161 dev_kfree_skb_any(skb); 162 163 /* Not NET_RX_DROP, this is not being dropped 164 * due to congestion. 165 */ 166 return 0; 167 } 168 169 skb->dev->last_rx = jiffies; 170 171 stats = vlan_dev_get_stats(skb->dev); 172 stats->rx_packets++; 173 stats->rx_bytes += skb->len; 174 175 skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag); 176 switch (skb->pkt_type) { 177 case PACKET_BROADCAST: 178 break; 179 180 case PACKET_MULTICAST: 181 stats->multicast++; 182 break; 183 184 case PACKET_OTHERHOST: 185 /* Our lower layer thinks this is not local, let's make sure. 186 * This allows the VLAN to have a different MAC than the underlying 187 * device, and still route correctly. 188 */ 189 if (!memcmp(eth_hdr(skb)->h_dest, skb->dev->dev_addr, ETH_ALEN)) 190 skb->pkt_type = PACKET_HOST; 191 break; 192 }; 193 194 return (polling ? netif_receive_skb(skb) : netif_rx(skb)); 195 } 196 197 static inline int vlan_hwaccel_rx(struct sk_buff *skb, 198 struct vlan_group *grp, 199 unsigned short vlan_tag) 200 { 201 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0); 202 } 203 204 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb, 205 struct vlan_group *grp, 206 unsigned short vlan_tag) 207 { 208 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1); 209 } 210 211 /** 212 * __vlan_put_tag - regular VLAN tag inserting 213 * @skb: skbuff to tag 214 * @tag: VLAN tag to insert 215 * 216 * Inserts the VLAN tag into @skb as part of the payload 217 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 218 * 219 * Following the skb_unshare() example, in case of error, the calling function 220 * doesn't have to worry about freeing the original skb. 221 */ 222 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag) 223 { 224 struct vlan_ethhdr *veth; 225 226 if (skb_headroom(skb) < VLAN_HLEN) { 227 struct sk_buff *sk_tmp = skb; 228 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN); 229 kfree_skb(sk_tmp); 230 if (!skb) { 231 printk(KERN_ERR "vlan: failed to realloc headroom\n"); 232 return NULL; 233 } 234 } else { 235 skb = skb_unshare(skb, GFP_ATOMIC); 236 if (!skb) { 237 printk(KERN_ERR "vlan: failed to unshare skbuff\n"); 238 return NULL; 239 } 240 } 241 242 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); 243 244 /* Move the mac addresses to the beginning of the new header. */ 245 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN); 246 247 /* first, the ethernet type */ 248 veth->h_vlan_proto = __constant_htons(ETH_P_8021Q); 249 250 /* now, the tag */ 251 veth->h_vlan_TCI = htons(tag); 252 253 skb->protocol = __constant_htons(ETH_P_8021Q); 254 skb->mac.raw -= VLAN_HLEN; 255 skb->nh.raw -= VLAN_HLEN; 256 257 return skb; 258 } 259 260 /** 261 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 262 * @skb: skbuff to tag 263 * @tag: VLAN tag to insert 264 * 265 * Puts the VLAN tag in @skb->cb[] and lets the device do the rest 266 */ 267 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag) 268 { 269 struct vlan_skb_tx_cookie *cookie; 270 271 cookie = VLAN_TX_SKB_CB(skb); 272 cookie->magic = VLAN_TX_COOKIE_MAGIC; 273 cookie->vlan_tag = tag; 274 275 return skb; 276 } 277 278 #define HAVE_VLAN_PUT_TAG 279 280 /** 281 * vlan_put_tag - inserts VLAN tag according to device features 282 * @skb: skbuff to tag 283 * @tag: VLAN tag to insert 284 * 285 * Assumes skb->dev is the target that will xmit this frame. 286 * Returns a VLAN tagged skb. 287 */ 288 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag) 289 { 290 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 291 return __vlan_hwaccel_put_tag(skb, tag); 292 } else { 293 return __vlan_put_tag(skb, tag); 294 } 295 } 296 297 /** 298 * __vlan_get_tag - get the VLAN ID that is part of the payload 299 * @skb: skbuff to query 300 * @tag: buffer to store vlaue 301 * 302 * Returns error if the skb is not of VLAN type 303 */ 304 static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag) 305 { 306 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 307 308 if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) { 309 return -EINVAL; 310 } 311 312 *tag = ntohs(veth->h_vlan_TCI); 313 314 return 0; 315 } 316 317 /** 318 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 319 * @skb: skbuff to query 320 * @tag: buffer to store vlaue 321 * 322 * Returns error if @skb->cb[] is not set correctly 323 */ 324 static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag) 325 { 326 struct vlan_skb_tx_cookie *cookie; 327 328 cookie = VLAN_TX_SKB_CB(skb); 329 if (cookie->magic == VLAN_TX_COOKIE_MAGIC) { 330 *tag = cookie->vlan_tag; 331 return 0; 332 } else { 333 *tag = 0; 334 return -EINVAL; 335 } 336 } 337 338 #define HAVE_VLAN_GET_TAG 339 340 /** 341 * vlan_get_tag - get the VLAN ID from the skb 342 * @skb: skbuff to query 343 * @tag: buffer to store vlaue 344 * 345 * Returns error if the skb is not VLAN tagged 346 */ 347 static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag) 348 { 349 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 350 return __vlan_hwaccel_get_tag(skb, tag); 351 } else { 352 return __vlan_get_tag(skb, tag); 353 } 354 } 355 356 #endif /* __KERNEL__ */ 357 358 /* VLAN IOCTLs are found in sockios.h */ 359 360 /* Passed in vlan_ioctl_args structure to determine behaviour. */ 361 enum vlan_ioctl_cmds { 362 ADD_VLAN_CMD, 363 DEL_VLAN_CMD, 364 SET_VLAN_INGRESS_PRIORITY_CMD, 365 SET_VLAN_EGRESS_PRIORITY_CMD, 366 GET_VLAN_INGRESS_PRIORITY_CMD, 367 GET_VLAN_EGRESS_PRIORITY_CMD, 368 SET_VLAN_NAME_TYPE_CMD, 369 SET_VLAN_FLAG_CMD, 370 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */ 371 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */ 372 }; 373 374 enum vlan_name_types { 375 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */ 376 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */ 377 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */ 378 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */ 379 VLAN_NAME_TYPE_HIGHEST 380 }; 381 382 struct vlan_ioctl_args { 383 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */ 384 char device1[24]; 385 386 union { 387 char device2[24]; 388 int VID; 389 unsigned int skb_priority; 390 unsigned int name_type; 391 unsigned int bind_type; 392 unsigned int flag; /* Matches vlan_dev_info flags */ 393 } u; 394 395 short vlan_qos; 396 }; 397 398 #endif /* !(_LINUX_IF_VLAN_H_) */ 399