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 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 __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 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 if (skb_bond_should_drop(skb)) { 159 dev_kfree_skb_any(skb); 160 return NET_RX_DROP; 161 } 162 163 skb->dev = grp->vlan_devices[vlan_tag & VLAN_VID_MASK]; 164 if (skb->dev == NULL) { 165 dev_kfree_skb_any(skb); 166 167 /* Not NET_RX_DROP, this is not being dropped 168 * due to congestion. 169 */ 170 return 0; 171 } 172 173 skb->dev->last_rx = jiffies; 174 175 stats = vlan_dev_get_stats(skb->dev); 176 stats->rx_packets++; 177 stats->rx_bytes += skb->len; 178 179 skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag); 180 switch (skb->pkt_type) { 181 case PACKET_BROADCAST: 182 break; 183 184 case PACKET_MULTICAST: 185 stats->multicast++; 186 break; 187 188 case PACKET_OTHERHOST: 189 /* Our lower layer thinks this is not local, let's make sure. 190 * This allows the VLAN to have a different MAC than the underlying 191 * device, and still route correctly. 192 */ 193 if (!compare_ether_addr(eth_hdr(skb)->h_dest, 194 skb->dev->dev_addr)) 195 skb->pkt_type = PACKET_HOST; 196 break; 197 }; 198 199 return (polling ? netif_receive_skb(skb) : netif_rx(skb)); 200 } 201 202 static inline int vlan_hwaccel_rx(struct sk_buff *skb, 203 struct vlan_group *grp, 204 unsigned short vlan_tag) 205 { 206 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0); 207 } 208 209 static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb, 210 struct vlan_group *grp, 211 unsigned short vlan_tag) 212 { 213 return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1); 214 } 215 216 /** 217 * __vlan_put_tag - regular VLAN tag inserting 218 * @skb: skbuff to tag 219 * @tag: VLAN tag to insert 220 * 221 * Inserts the VLAN tag into @skb as part of the payload 222 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 223 * 224 * Following the skb_unshare() example, in case of error, the calling function 225 * doesn't have to worry about freeing the original skb. 226 */ 227 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag) 228 { 229 struct vlan_ethhdr *veth; 230 231 if (skb_headroom(skb) < VLAN_HLEN) { 232 struct sk_buff *sk_tmp = skb; 233 skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN); 234 kfree_skb(sk_tmp); 235 if (!skb) { 236 printk(KERN_ERR "vlan: failed to realloc headroom\n"); 237 return NULL; 238 } 239 } else { 240 skb = skb_unshare(skb, GFP_ATOMIC); 241 if (!skb) { 242 printk(KERN_ERR "vlan: failed to unshare skbuff\n"); 243 return NULL; 244 } 245 } 246 247 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); 248 249 /* Move the mac addresses to the beginning of the new header. */ 250 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN); 251 252 /* first, the ethernet type */ 253 veth->h_vlan_proto = __constant_htons(ETH_P_8021Q); 254 255 /* now, the tag */ 256 veth->h_vlan_TCI = htons(tag); 257 258 skb->protocol = __constant_htons(ETH_P_8021Q); 259 skb->mac.raw -= VLAN_HLEN; 260 skb->nh.raw -= VLAN_HLEN; 261 262 return skb; 263 } 264 265 /** 266 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 267 * @skb: skbuff to tag 268 * @tag: VLAN tag to insert 269 * 270 * Puts the VLAN tag in @skb->cb[] and lets the device do the rest 271 */ 272 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag) 273 { 274 struct vlan_skb_tx_cookie *cookie; 275 276 cookie = VLAN_TX_SKB_CB(skb); 277 cookie->magic = VLAN_TX_COOKIE_MAGIC; 278 cookie->vlan_tag = tag; 279 280 return skb; 281 } 282 283 #define HAVE_VLAN_PUT_TAG 284 285 /** 286 * vlan_put_tag - inserts VLAN tag according to device features 287 * @skb: skbuff to tag 288 * @tag: VLAN tag to insert 289 * 290 * Assumes skb->dev is the target that will xmit this frame. 291 * Returns a VLAN tagged skb. 292 */ 293 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag) 294 { 295 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 296 return __vlan_hwaccel_put_tag(skb, tag); 297 } else { 298 return __vlan_put_tag(skb, tag); 299 } 300 } 301 302 /** 303 * __vlan_get_tag - get the VLAN ID that is part of the payload 304 * @skb: skbuff to query 305 * @tag: buffer to store vlaue 306 * 307 * Returns error if the skb is not of VLAN type 308 */ 309 static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag) 310 { 311 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 312 313 if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) { 314 return -EINVAL; 315 } 316 317 *tag = ntohs(veth->h_vlan_TCI); 318 319 return 0; 320 } 321 322 /** 323 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 324 * @skb: skbuff to query 325 * @tag: buffer to store vlaue 326 * 327 * Returns error if @skb->cb[] is not set correctly 328 */ 329 static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag) 330 { 331 struct vlan_skb_tx_cookie *cookie; 332 333 cookie = VLAN_TX_SKB_CB(skb); 334 if (cookie->magic == VLAN_TX_COOKIE_MAGIC) { 335 *tag = cookie->vlan_tag; 336 return 0; 337 } else { 338 *tag = 0; 339 return -EINVAL; 340 } 341 } 342 343 #define HAVE_VLAN_GET_TAG 344 345 /** 346 * vlan_get_tag - get the VLAN ID from the skb 347 * @skb: skbuff to query 348 * @tag: buffer to store vlaue 349 * 350 * Returns error if the skb is not VLAN tagged 351 */ 352 static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag) 353 { 354 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 355 return __vlan_hwaccel_get_tag(skb, tag); 356 } else { 357 return __vlan_get_tag(skb, tag); 358 } 359 } 360 361 #endif /* __KERNEL__ */ 362 363 /* VLAN IOCTLs are found in sockios.h */ 364 365 /* Passed in vlan_ioctl_args structure to determine behaviour. */ 366 enum vlan_ioctl_cmds { 367 ADD_VLAN_CMD, 368 DEL_VLAN_CMD, 369 SET_VLAN_INGRESS_PRIORITY_CMD, 370 SET_VLAN_EGRESS_PRIORITY_CMD, 371 GET_VLAN_INGRESS_PRIORITY_CMD, 372 GET_VLAN_EGRESS_PRIORITY_CMD, 373 SET_VLAN_NAME_TYPE_CMD, 374 SET_VLAN_FLAG_CMD, 375 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */ 376 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */ 377 }; 378 379 enum vlan_name_types { 380 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */ 381 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */ 382 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */ 383 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */ 384 VLAN_NAME_TYPE_HIGHEST 385 }; 386 387 struct vlan_ioctl_args { 388 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */ 389 char device1[24]; 390 391 union { 392 char device2[24]; 393 int VID; 394 unsigned int skb_priority; 395 unsigned int name_type; 396 unsigned int bind_type; 397 unsigned int flag; /* Matches vlan_dev_info flags */ 398 } u; 399 400 short vlan_qos; 401 }; 402 403 #endif /* !(_LINUX_IF_VLAN_H_) */ 404