if_vlan.h 11 KB

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  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. #ifndef _LINUX_IF_VLAN_H_
  13. #define _LINUX_IF_VLAN_H_
  14. #ifdef __KERNEL__
  15. #include <linux/netdevice.h>
  16. #include <linux/etherdevice.h>
  17. #include <linux/rtnetlink.h>
  18. #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header)
  19. * that VLAN requires.
  20. */
  21. #define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */
  22. #define VLAN_ETH_HLEN 18 /* Total octets in header. */
  23. #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
  24. /*
  25. * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  26. */
  27. #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
  28. #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
  29. /*
  30. * struct vlan_hdr - vlan header
  31. * @h_vlan_TCI: priority and VLAN ID
  32. * @h_vlan_encapsulated_proto: packet type ID or len
  33. */
  34. struct vlan_hdr {
  35. __be16 h_vlan_TCI;
  36. __be16 h_vlan_encapsulated_proto;
  37. };
  38. /**
  39. * struct vlan_ethhdr - vlan ethernet header (ethhdr + vlan_hdr)
  40. * @h_dest: destination ethernet address
  41. * @h_source: source ethernet address
  42. * @h_vlan_proto: ethernet protocol (always 0x8100)
  43. * @h_vlan_TCI: priority and VLAN ID
  44. * @h_vlan_encapsulated_proto: packet type ID or len
  45. */
  46. struct vlan_ethhdr {
  47. unsigned char h_dest[ETH_ALEN];
  48. unsigned char h_source[ETH_ALEN];
  49. __be16 h_vlan_proto;
  50. __be16 h_vlan_TCI;
  51. __be16 h_vlan_encapsulated_proto;
  52. };
  53. #include <linux/skbuff.h>
  54. static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  55. {
  56. return (struct vlan_ethhdr *)skb_mac_header(skb);
  57. }
  58. #define VLAN_PRIO_MASK 0xe000 /* Priority Code Point */
  59. #define VLAN_PRIO_SHIFT 13
  60. #define VLAN_CFI_MASK 0x1000 /* Canonical Format Indicator */
  61. #define VLAN_TAG_PRESENT VLAN_CFI_MASK
  62. #define VLAN_VID_MASK 0x0fff /* VLAN Identifier */
  63. #define VLAN_N_VID 4096
  64. /* found in socket.c */
  65. extern void vlan_ioctl_set(int (*hook)(struct net *, void __user *));
  66. /* if this changes, algorithm will have to be reworked because this
  67. * depends on completely exhausting the VLAN identifier space. Thus
  68. * it gives constant time look-up, but in many cases it wastes memory.
  69. */
  70. #define VLAN_GROUP_ARRAY_SPLIT_PARTS 8
  71. #define VLAN_GROUP_ARRAY_PART_LEN (VLAN_N_VID/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  72. struct vlan_group {
  73. struct net_device *real_dev; /* The ethernet(like) device
  74. * the vlan is attached to.
  75. */
  76. unsigned int nr_vlans;
  77. struct hlist_node hlist; /* linked list */
  78. struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  79. struct rcu_head rcu;
  80. };
  81. static inline int is_vlan_dev(struct net_device *dev)
  82. {
  83. return dev->priv_flags & IFF_802_1Q_VLAN;
  84. }
  85. #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  86. #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  87. #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  88. extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  89. u16 vlan_id);
  90. extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  91. extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  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. extern int vlan_vid_add(struct net_device *dev, unsigned short vid);
  95. extern void vlan_vid_del(struct net_device *dev, unsigned short vid);
  96. #else
  97. static inline struct net_device *
  98. __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
  99. {
  100. return NULL;
  101. }
  102. static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  103. {
  104. BUG();
  105. return NULL;
  106. }
  107. static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
  108. {
  109. BUG();
  110. return 0;
  111. }
  112. static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler)
  113. {
  114. if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler)
  115. (*skb)->pkt_type = PACKET_OTHERHOST;
  116. return false;
  117. }
  118. static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
  119. {
  120. return skb;
  121. }
  122. static inline int vlan_vid_add(struct net_device *dev, unsigned short vid)
  123. {
  124. return 0;
  125. }
  126. static inline void vlan_vid_del(struct net_device *dev, unsigned short vid)
  127. {
  128. }
  129. #endif
  130. /**
  131. * vlan_insert_tag - regular VLAN tag inserting
  132. * @skb: skbuff to tag
  133. * @vlan_tci: VLAN TCI to insert
  134. *
  135. * Inserts the VLAN tag into @skb as part of the payload
  136. * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
  137. *
  138. * Following the skb_unshare() example, in case of error, the calling function
  139. * doesn't have to worry about freeing the original skb.
  140. *
  141. * Does not change skb->protocol so this function can be used during receive.
  142. */
  143. static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
  144. {
  145. struct vlan_ethhdr *veth;
  146. if (skb_cow_head(skb, VLAN_HLEN) < 0) {
  147. kfree_skb(skb);
  148. return NULL;
  149. }
  150. veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
  151. /* Move the mac addresses to the beginning of the new header. */
  152. memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
  153. skb->mac_header -= VLAN_HLEN;
  154. /* first, the ethernet type */
  155. veth->h_vlan_proto = htons(ETH_P_8021Q);
  156. /* now, the TCI */
  157. veth->h_vlan_TCI = htons(vlan_tci);
  158. return skb;
  159. }
  160. /**
  161. * __vlan_put_tag - regular VLAN tag inserting
  162. * @skb: skbuff to tag
  163. * @vlan_tci: VLAN TCI to insert
  164. *
  165. * Inserts the VLAN tag into @skb as part of the payload
  166. * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
  167. *
  168. * Following the skb_unshare() example, in case of error, the calling function
  169. * doesn't have to worry about freeing the original skb.
  170. */
  171. static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
  172. {
  173. skb = vlan_insert_tag(skb, vlan_tci);
  174. if (skb)
  175. skb->protocol = htons(ETH_P_8021Q);
  176. return skb;
  177. }
  178. /**
  179. * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
  180. * @skb: skbuff to tag
  181. * @vlan_tci: VLAN TCI to insert
  182. *
  183. * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
  184. */
  185. static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
  186. u16 vlan_tci)
  187. {
  188. skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
  189. return skb;
  190. }
  191. #define HAVE_VLAN_PUT_TAG
  192. /**
  193. * vlan_put_tag - inserts VLAN tag according to device features
  194. * @skb: skbuff to tag
  195. * @vlan_tci: VLAN TCI to insert
  196. *
  197. * Assumes skb->dev is the target that will xmit this frame.
  198. * Returns a VLAN tagged skb.
  199. */
  200. static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
  201. {
  202. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  203. return __vlan_hwaccel_put_tag(skb, vlan_tci);
  204. } else {
  205. return __vlan_put_tag(skb, vlan_tci);
  206. }
  207. }
  208. /**
  209. * __vlan_get_tag - get the VLAN ID that is part of the payload
  210. * @skb: skbuff to query
  211. * @vlan_tci: buffer to store vlaue
  212. *
  213. * Returns error if the skb is not of VLAN type
  214. */
  215. static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  216. {
  217. struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
  218. if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
  219. return -EINVAL;
  220. }
  221. *vlan_tci = ntohs(veth->h_vlan_TCI);
  222. return 0;
  223. }
  224. /**
  225. * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
  226. * @skb: skbuff to query
  227. * @vlan_tci: buffer to store vlaue
  228. *
  229. * Returns error if @skb->vlan_tci is not set correctly
  230. */
  231. static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
  232. u16 *vlan_tci)
  233. {
  234. if (vlan_tx_tag_present(skb)) {
  235. *vlan_tci = vlan_tx_tag_get(skb);
  236. return 0;
  237. } else {
  238. *vlan_tci = 0;
  239. return -EINVAL;
  240. }
  241. }
  242. #define HAVE_VLAN_GET_TAG
  243. /**
  244. * vlan_get_tag - get the VLAN ID from the skb
  245. * @skb: skbuff to query
  246. * @vlan_tci: buffer to store vlaue
  247. *
  248. * Returns error if the skb is not VLAN tagged
  249. */
  250. static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  251. {
  252. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  253. return __vlan_hwaccel_get_tag(skb, vlan_tci);
  254. } else {
  255. return __vlan_get_tag(skb, vlan_tci);
  256. }
  257. }
  258. /**
  259. * vlan_get_protocol - get protocol EtherType.
  260. * @skb: skbuff to query
  261. *
  262. * Returns the EtherType of the packet, regardless of whether it is
  263. * vlan encapsulated (normal or hardware accelerated) or not.
  264. */
  265. static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
  266. {
  267. __be16 protocol = 0;
  268. if (vlan_tx_tag_present(skb) ||
  269. skb->protocol != cpu_to_be16(ETH_P_8021Q))
  270. protocol = skb->protocol;
  271. else {
  272. __be16 proto, *protop;
  273. protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
  274. h_vlan_encapsulated_proto),
  275. sizeof(proto), &proto);
  276. if (likely(protop))
  277. protocol = *protop;
  278. }
  279. return protocol;
  280. }
  281. static inline void vlan_set_encap_proto(struct sk_buff *skb,
  282. struct vlan_hdr *vhdr)
  283. {
  284. __be16 proto;
  285. unsigned char *rawp;
  286. /*
  287. * Was a VLAN packet, grab the encapsulated protocol, which the layer
  288. * three protocols care about.
  289. */
  290. proto = vhdr->h_vlan_encapsulated_proto;
  291. if (ntohs(proto) >= 1536) {
  292. skb->protocol = proto;
  293. return;
  294. }
  295. rawp = skb->data;
  296. if (*(unsigned short *) rawp == 0xFFFF)
  297. /*
  298. * This is a magic hack to spot IPX packets. Older Novell
  299. * breaks the protocol design and runs IPX over 802.3 without
  300. * an 802.2 LLC layer. We look for FFFF which isn't a used
  301. * 802.2 SSAP/DSAP. This won't work for fault tolerant netware
  302. * but does for the rest.
  303. */
  304. skb->protocol = htons(ETH_P_802_3);
  305. else
  306. /*
  307. * Real 802.2 LLC
  308. */
  309. skb->protocol = htons(ETH_P_802_2);
  310. }
  311. #endif /* __KERNEL__ */
  312. /* VLAN IOCTLs are found in sockios.h */
  313. /* Passed in vlan_ioctl_args structure to determine behaviour. */
  314. enum vlan_ioctl_cmds {
  315. ADD_VLAN_CMD,
  316. DEL_VLAN_CMD,
  317. SET_VLAN_INGRESS_PRIORITY_CMD,
  318. SET_VLAN_EGRESS_PRIORITY_CMD,
  319. GET_VLAN_INGRESS_PRIORITY_CMD,
  320. GET_VLAN_EGRESS_PRIORITY_CMD,
  321. SET_VLAN_NAME_TYPE_CMD,
  322. SET_VLAN_FLAG_CMD,
  323. GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
  324. GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
  325. };
  326. enum vlan_flags {
  327. VLAN_FLAG_REORDER_HDR = 0x1,
  328. VLAN_FLAG_GVRP = 0x2,
  329. VLAN_FLAG_LOOSE_BINDING = 0x4,
  330. };
  331. enum vlan_name_types {
  332. VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */
  333. VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */
  334. VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */
  335. VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */
  336. VLAN_NAME_TYPE_HIGHEST
  337. };
  338. struct vlan_ioctl_args {
  339. int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
  340. char device1[24];
  341. union {
  342. char device2[24];
  343. int VID;
  344. unsigned int skb_priority;
  345. unsigned int name_type;
  346. unsigned int bind_type;
  347. unsigned int flag; /* Matches vlan_dev_priv flags */
  348. } u;
  349. short vlan_qos;
  350. };
  351. #endif /* !(_LINUX_IF_VLAN_H_) */