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 #include <linux/netdevice.h> 18 #include <linux/etherdevice.h> 19 #include <linux/rtnetlink.h> 20 21 #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header) 22 * that VLAN requires. 23 */ 24 #define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */ 25 #define VLAN_ETH_HLEN 18 /* Total octets in header. */ 26 #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */ 27 28 /* 29 * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan 30 */ 31 #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */ 32 #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */ 33 34 /* 35 * struct vlan_hdr - vlan header 36 * @h_vlan_TCI: priority and VLAN ID 37 * @h_vlan_encapsulated_proto: packet type ID or len 38 */ 39 struct vlan_hdr { 40 __be16 h_vlan_TCI; 41 __be16 h_vlan_encapsulated_proto; 42 }; 43 44 /** 45 * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr) 46 * @h_dest: destination ethernet address 47 * @h_source: source ethernet address 48 * @h_vlan_proto: ethernet protocol (always 0x8100) 49 * @h_vlan_TCI: priority and VLAN ID 50 * @h_vlan_encapsulated_proto: packet type ID or len 51 */ 52 struct vlan_ethhdr { 53 unsigned char h_dest[ETH_ALEN]; 54 unsigned char h_source[ETH_ALEN]; 55 __be16 h_vlan_proto; 56 __be16 h_vlan_TCI; 57 __be16 h_vlan_encapsulated_proto; 58 }; 59 60 #include <linux/skbuff.h> 61 62 static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb) 63 { 64 return (struct vlan_ethhdr *)skb_mac_header(skb); 65 } 66 67 #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */ 68 #define VLAN_PRIO_SHIFT 13 69 #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */ 70 #define VLAN_TAG_PRESENT VLAN_CFI_MASK 71 #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */ 72 #define VLAN_N_VID 4096 73 74 /* found in socket.c */ 75 extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *)); 76 77 struct vlan_info; 78 79 static inline int is_vlan_dev(struct net_device *dev) 80 { 81 return dev->priv_flags & IFF_802_1Q_VLAN; 82 } 83 84 #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) 85 #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) 86 87 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) 88 89 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, 90 u16 vlan_id); 91 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); 92 extern u16 vlan_dev_vlan_id(const struct net_device *dev); 93 94 extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler); 95 extern struct sk_buff *vlan_untag(struct sk_buff *skb); 96 97 extern int vlan_vid_add(struct net_device *dev, unsigned short vid); 98 extern void vlan_vid_del(struct net_device *dev, unsigned short vid); 99 100 extern int vlan_vids_add_by_dev(struct net_device *dev, 101 const struct net_device *by_dev); 102 extern void vlan_vids_del_by_dev(struct net_device *dev, 103 const struct net_device *by_dev); 104 #else 105 static inline struct net_device * 106 __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id) 107 { 108 return NULL; 109 } 110 111 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev) 112 { 113 BUG(); 114 return NULL; 115 } 116 117 static inline u16 vlan_dev_vlan_id(const struct net_device *dev) 118 { 119 BUG(); 120 return 0; 121 } 122 123 static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler) 124 { 125 if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler) 126 (*skb)->pkt_type = PACKET_OTHERHOST; 127 return false; 128 } 129 130 static inline struct sk_buff *vlan_untag(struct sk_buff *skb) 131 { 132 return skb; 133 } 134 135 static inline int vlan_vid_add(struct net_device *dev, unsigned short vid) 136 { 137 return 0; 138 } 139 140 static inline void vlan_vid_del(struct net_device *dev, unsigned short vid) 141 { 142 } 143 144 static inline int vlan_vids_add_by_dev(struct net_device *dev, 145 const struct net_device *by_dev) 146 { 147 return 0; 148 } 149 150 static inline void vlan_vids_del_by_dev(struct net_device *dev, 151 const struct net_device *by_dev) 152 { 153 } 154 #endif 155 156 /** 157 * vlan_insert_tag - regular VLAN tag inserting 158 * @skb: skbuff to tag 159 * @vlan_tci: VLAN TCI to insert 160 * 161 * Inserts the VLAN tag into @skb as part of the payload 162 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 163 * 164 * Following the skb_unshare() example, in case of error, the calling function 165 * doesn't have to worry about freeing the original skb. 166 * 167 * Does not change skb->protocol so this function can be used during receive. 168 */ 169 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci) 170 { 171 struct vlan_ethhdr *veth; 172 173 if (skb_cow_head(skb, VLAN_HLEN) < 0) { 174 kfree_skb(skb); 175 return NULL; 176 } 177 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); 178 179 /* Move the mac addresses to the beginning of the new header. */ 180 memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN); 181 skb->mac_header -= VLAN_HLEN; 182 183 /* first, the ethernet type */ 184 veth->h_vlan_proto = htons(ETH_P_8021Q); 185 186 /* now, the TCI */ 187 veth->h_vlan_TCI = htons(vlan_tci); 188 189 return skb; 190 } 191 192 /** 193 * __vlan_put_tag - regular VLAN tag inserting 194 * @skb: skbuff to tag 195 * @vlan_tci: VLAN TCI to insert 196 * 197 * Inserts the VLAN tag into @skb as part of the payload 198 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 199 * 200 * Following the skb_unshare() example, in case of error, the calling function 201 * doesn't have to worry about freeing the original skb. 202 */ 203 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) 204 { 205 skb = vlan_insert_tag(skb, vlan_tci); 206 if (skb) 207 skb->protocol = htons(ETH_P_8021Q); 208 return skb; 209 } 210 211 /** 212 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 213 * @skb: skbuff to tag 214 * @vlan_tci: VLAN TCI to insert 215 * 216 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest 217 */ 218 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, 219 u16 vlan_tci) 220 { 221 skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci; 222 return skb; 223 } 224 225 #define HAVE_VLAN_PUT_TAG 226 227 /** 228 * vlan_put_tag - inserts VLAN tag according to device features 229 * @skb: skbuff to tag 230 * @vlan_tci: VLAN TCI to insert 231 * 232 * Assumes skb->dev is the target that will xmit this frame. 233 * Returns a VLAN tagged skb. 234 */ 235 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) 236 { 237 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 238 return __vlan_hwaccel_put_tag(skb, vlan_tci); 239 } else { 240 return __vlan_put_tag(skb, vlan_tci); 241 } 242 } 243 244 /** 245 * __vlan_get_tag - get the VLAN ID that is part of the payload 246 * @skb: skbuff to query 247 * @vlan_tci: buffer to store vlaue 248 * 249 * Returns error if the skb is not of VLAN type 250 */ 251 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 252 { 253 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 254 255 if (veth->h_vlan_proto != htons(ETH_P_8021Q)) { 256 return -EINVAL; 257 } 258 259 *vlan_tci = ntohs(veth->h_vlan_TCI); 260 return 0; 261 } 262 263 /** 264 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 265 * @skb: skbuff to query 266 * @vlan_tci: buffer to store vlaue 267 * 268 * Returns error if @skb->vlan_tci is not set correctly 269 */ 270 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 271 u16 *vlan_tci) 272 { 273 if (vlan_tx_tag_present(skb)) { 274 *vlan_tci = vlan_tx_tag_get(skb); 275 return 0; 276 } else { 277 *vlan_tci = 0; 278 return -EINVAL; 279 } 280 } 281 282 #define HAVE_VLAN_GET_TAG 283 284 /** 285 * vlan_get_tag - get the VLAN ID from the skb 286 * @skb: skbuff to query 287 * @vlan_tci: buffer to store vlaue 288 * 289 * Returns error if the skb is not VLAN tagged 290 */ 291 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 292 { 293 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 294 return __vlan_hwaccel_get_tag(skb, vlan_tci); 295 } else { 296 return __vlan_get_tag(skb, vlan_tci); 297 } 298 } 299 300 /** 301 * vlan_get_protocol - get protocol EtherType. 302 * @skb: skbuff to query 303 * 304 * Returns the EtherType of the packet, regardless of whether it is 305 * vlan encapsulated (normal or hardware accelerated) or not. 306 */ 307 static inline __be16 vlan_get_protocol(const struct sk_buff *skb) 308 { 309 __be16 protocol = 0; 310 311 if (vlan_tx_tag_present(skb) || 312 skb->protocol != cpu_to_be16(ETH_P_8021Q)) 313 protocol = skb->protocol; 314 else { 315 __be16 proto, *protop; 316 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr, 317 h_vlan_encapsulated_proto), 318 sizeof(proto), &proto); 319 if (likely(protop)) 320 protocol = *protop; 321 } 322 323 return protocol; 324 } 325 326 static inline void vlan_set_encap_proto(struct sk_buff *skb, 327 struct vlan_hdr *vhdr) 328 { 329 __be16 proto; 330 unsigned char *rawp; 331 332 /* 333 * Was a VLAN packet, grab the encapsulated protocol, which the layer 334 * three protocols care about. 335 */ 336 337 proto = vhdr->h_vlan_encapsulated_proto; 338 if (ntohs(proto) >= 1536) { 339 skb->protocol = proto; 340 return; 341 } 342 343 rawp = skb->data; 344 if (*(unsigned short *) rawp == 0xFFFF) 345 /* 346 * This is a magic hack to spot IPX packets. Older Novell 347 * breaks the protocol design and runs IPX over 802.3 without 348 * an 802.2 LLC layer. We look for FFFF which isn't a used 349 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 350 * but does for the rest. 351 */ 352 skb->protocol = htons(ETH_P_802_3); 353 else 354 /* 355 * Real 802.2 LLC 356 */ 357 skb->protocol = htons(ETH_P_802_2); 358 } 359 #endif /* __KERNEL__ */ 360 361 /* VLAN IOCTLs are found in sockios.h */ 362 363 /* Passed in vlan_ioctl_args structure to determine behaviour. */ 364 enum vlan_ioctl_cmds { 365 ADD_VLAN_CMD, 366 DEL_VLAN_CMD, 367 SET_VLAN_INGRESS_PRIORITY_CMD, 368 SET_VLAN_EGRESS_PRIORITY_CMD, 369 GET_VLAN_INGRESS_PRIORITY_CMD, 370 GET_VLAN_EGRESS_PRIORITY_CMD, 371 SET_VLAN_NAME_TYPE_CMD, 372 SET_VLAN_FLAG_CMD, 373 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */ 374 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */ 375 }; 376 377 enum vlan_flags { 378 VLAN_FLAG_REORDER_HDR = 0x1, 379 VLAN_FLAG_GVRP = 0x2, 380 VLAN_FLAG_LOOSE_BINDING = 0x4, 381 }; 382 383 enum vlan_name_types { 384 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */ 385 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */ 386 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */ 387 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */ 388 VLAN_NAME_TYPE_HIGHEST 389 }; 390 391 struct vlan_ioctl_args { 392 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */ 393 char device1[24]; 394 395 union { 396 char device2[24]; 397 int VID; 398 unsigned int skb_priority; 399 unsigned int name_type; 400 unsigned int bind_type; 401 unsigned int flag; /* Matches vlan_dev_priv flags */ 402 } u; 403 404 short vlan_qos; 405 }; 406 407 #endif /* !(_LINUX_IF_VLAN_H_) */ 408