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 #include <linux/bug.h> 21 22 #define VLAN_HLEN 4 /* The additional bytes required by VLAN 23 * (in addition to the Ethernet header) 24 */ 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 static inline int is_vlan_dev(struct net_device *dev) 78 { 79 return dev->priv_flags & IFF_802_1Q_VLAN; 80 } 81 82 #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT) 83 #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT) 84 85 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) 86 87 extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, 88 u16 vlan_id); 89 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev); 90 extern u16 vlan_dev_vlan_id(const struct net_device *dev); 91 92 extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler); 93 extern struct sk_buff *vlan_untag(struct sk_buff *skb); 94 95 extern int vlan_vid_add(struct net_device *dev, unsigned short vid); 96 extern void vlan_vid_del(struct net_device *dev, unsigned short vid); 97 98 extern int vlan_vids_add_by_dev(struct net_device *dev, 99 const struct net_device *by_dev); 100 extern void vlan_vids_del_by_dev(struct net_device *dev, 101 const struct net_device *by_dev); 102 103 extern bool vlan_uses_dev(const struct net_device *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 } 154 155 static inline bool vlan_uses_dev(const struct net_device *dev) 156 { 157 return false; 158 } 159 #endif 160 161 /** 162 * vlan_insert_tag - regular VLAN tag inserting 163 * @skb: skbuff to tag 164 * @vlan_tci: VLAN TCI to insert 165 * 166 * Inserts the VLAN tag into @skb as part of the payload 167 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 168 * 169 * Following the skb_unshare() example, in case of error, the calling function 170 * doesn't have to worry about freeing the original skb. 171 * 172 * Does not change skb->protocol so this function can be used during receive. 173 */ 174 static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci) 175 { 176 struct vlan_ethhdr *veth; 177 178 if (skb_cow_head(skb, VLAN_HLEN) < 0) { 179 kfree_skb(skb); 180 return NULL; 181 } 182 veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN); 183 184 /* Move the mac addresses to the beginning of the new header. */ 185 memmove(skb->data, skb->data + VLAN_HLEN, 2 * ETH_ALEN); 186 skb->mac_header -= VLAN_HLEN; 187 188 /* first, the ethernet type */ 189 veth->h_vlan_proto = htons(ETH_P_8021Q); 190 191 /* now, the TCI */ 192 veth->h_vlan_TCI = htons(vlan_tci); 193 194 return skb; 195 } 196 197 /** 198 * __vlan_put_tag - regular VLAN tag inserting 199 * @skb: skbuff to tag 200 * @vlan_tci: VLAN TCI to insert 201 * 202 * Inserts the VLAN tag into @skb as part of the payload 203 * Returns a VLAN tagged skb. If a new skb is created, @skb is freed. 204 * 205 * Following the skb_unshare() example, in case of error, the calling function 206 * doesn't have to worry about freeing the original skb. 207 */ 208 static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) 209 { 210 skb = vlan_insert_tag(skb, vlan_tci); 211 if (skb) 212 skb->protocol = htons(ETH_P_8021Q); 213 return skb; 214 } 215 216 /** 217 * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting 218 * @skb: skbuff to tag 219 * @vlan_tci: VLAN TCI to insert 220 * 221 * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest 222 */ 223 static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, 224 u16 vlan_tci) 225 { 226 skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci; 227 return skb; 228 } 229 230 #define HAVE_VLAN_PUT_TAG 231 232 /** 233 * vlan_put_tag - inserts VLAN tag according to device features 234 * @skb: skbuff to tag 235 * @vlan_tci: VLAN TCI to insert 236 * 237 * Assumes skb->dev is the target that will xmit this frame. 238 * Returns a VLAN tagged skb. 239 */ 240 static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci) 241 { 242 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 243 return __vlan_hwaccel_put_tag(skb, vlan_tci); 244 } else { 245 return __vlan_put_tag(skb, vlan_tci); 246 } 247 } 248 249 /** 250 * __vlan_get_tag - get the VLAN ID that is part of the payload 251 * @skb: skbuff to query 252 * @vlan_tci: buffer to store vlaue 253 * 254 * Returns error if the skb is not of VLAN type 255 */ 256 static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 257 { 258 struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data; 259 260 if (veth->h_vlan_proto != htons(ETH_P_8021Q)) { 261 return -EINVAL; 262 } 263 264 *vlan_tci = ntohs(veth->h_vlan_TCI); 265 return 0; 266 } 267 268 /** 269 * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[] 270 * @skb: skbuff to query 271 * @vlan_tci: buffer to store vlaue 272 * 273 * Returns error if @skb->vlan_tci is not set correctly 274 */ 275 static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb, 276 u16 *vlan_tci) 277 { 278 if (vlan_tx_tag_present(skb)) { 279 *vlan_tci = vlan_tx_tag_get(skb); 280 return 0; 281 } else { 282 *vlan_tci = 0; 283 return -EINVAL; 284 } 285 } 286 287 #define HAVE_VLAN_GET_TAG 288 289 /** 290 * vlan_get_tag - get the VLAN ID from the skb 291 * @skb: skbuff to query 292 * @vlan_tci: buffer to store vlaue 293 * 294 * Returns error if the skb is not VLAN tagged 295 */ 296 static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci) 297 { 298 if (skb->dev->features & NETIF_F_HW_VLAN_TX) { 299 return __vlan_hwaccel_get_tag(skb, vlan_tci); 300 } else { 301 return __vlan_get_tag(skb, vlan_tci); 302 } 303 } 304 305 /** 306 * vlan_get_protocol - get protocol EtherType. 307 * @skb: skbuff to query 308 * 309 * Returns the EtherType of the packet, regardless of whether it is 310 * vlan encapsulated (normal or hardware accelerated) or not. 311 */ 312 static inline __be16 vlan_get_protocol(const struct sk_buff *skb) 313 { 314 __be16 protocol = 0; 315 316 if (vlan_tx_tag_present(skb) || 317 skb->protocol != cpu_to_be16(ETH_P_8021Q)) 318 protocol = skb->protocol; 319 else { 320 __be16 proto, *protop; 321 protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr, 322 h_vlan_encapsulated_proto), 323 sizeof(proto), &proto); 324 if (likely(protop)) 325 protocol = *protop; 326 } 327 328 return protocol; 329 } 330 331 static inline void vlan_set_encap_proto(struct sk_buff *skb, 332 struct vlan_hdr *vhdr) 333 { 334 __be16 proto; 335 unsigned char *rawp; 336 337 /* 338 * Was a VLAN packet, grab the encapsulated protocol, which the layer 339 * three protocols care about. 340 */ 341 342 proto = vhdr->h_vlan_encapsulated_proto; 343 if (ntohs(proto) >= 1536) { 344 skb->protocol = proto; 345 return; 346 } 347 348 rawp = skb->data; 349 if (*(unsigned short *) rawp == 0xFFFF) 350 /* 351 * This is a magic hack to spot IPX packets. Older Novell 352 * breaks the protocol design and runs IPX over 802.3 without 353 * an 802.2 LLC layer. We look for FFFF which isn't a used 354 * 802.2 SSAP/DSAP. This won't work for fault tolerant netware 355 * but does for the rest. 356 */ 357 skb->protocol = htons(ETH_P_802_3); 358 else 359 /* 360 * Real 802.2 LLC 361 */ 362 skb->protocol = htons(ETH_P_802_2); 363 } 364 #endif /* __KERNEL__ */ 365 366 /* VLAN IOCTLs are found in sockios.h */ 367 368 /* Passed in vlan_ioctl_args structure to determine behaviour. */ 369 enum vlan_ioctl_cmds { 370 ADD_VLAN_CMD, 371 DEL_VLAN_CMD, 372 SET_VLAN_INGRESS_PRIORITY_CMD, 373 SET_VLAN_EGRESS_PRIORITY_CMD, 374 GET_VLAN_INGRESS_PRIORITY_CMD, 375 GET_VLAN_EGRESS_PRIORITY_CMD, 376 SET_VLAN_NAME_TYPE_CMD, 377 SET_VLAN_FLAG_CMD, 378 GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */ 379 GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */ 380 }; 381 382 enum vlan_flags { 383 VLAN_FLAG_REORDER_HDR = 0x1, 384 VLAN_FLAG_GVRP = 0x2, 385 VLAN_FLAG_LOOSE_BINDING = 0x4, 386 }; 387 388 enum vlan_name_types { 389 VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */ 390 VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */ 391 VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */ 392 VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */ 393 VLAN_NAME_TYPE_HIGHEST 394 }; 395 396 struct vlan_ioctl_args { 397 int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */ 398 char device1[24]; 399 400 union { 401 char device2[24]; 402 int VID; 403 unsigned int skb_priority; 404 unsigned int name_type; 405 unsigned int bind_type; 406 unsigned int flag; /* Matches vlan_dev_priv flags */ 407 } u; 408 409 short vlan_qos; 410 }; 411 412 #endif /* !(_LINUX_IF_VLAN_H_) */ 413