if_vlan.h 10 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 struct net_device *vlan_group_get_device(struct vlan_group *vg,
  82. u16 vlan_id)
  83. {
  84. struct net_device **array;
  85. array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  86. return array ? array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] : NULL;
  87. }
  88. static inline void vlan_group_set_device(struct vlan_group *vg,
  89. u16 vlan_id,
  90. struct net_device *dev)
  91. {
  92. struct net_device **array;
  93. if (!vg)
  94. return;
  95. array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  96. array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
  97. }
  98. static inline int is_vlan_dev(struct net_device *dev)
  99. {
  100. return dev->priv_flags & IFF_802_1Q_VLAN;
  101. }
  102. #define vlan_tx_tag_present(__skb) ((__skb)->vlan_tci & VLAN_TAG_PRESENT)
  103. #define vlan_tx_tag_get(__skb) ((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
  104. #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
  105. extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
  106. u16 vlan_id);
  107. extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
  108. extern u16 vlan_dev_vlan_id(const struct net_device *dev);
  109. extern bool vlan_do_receive(struct sk_buff **skb);
  110. extern struct sk_buff *vlan_untag(struct sk_buff *skb);
  111. #else
  112. static inline struct net_device *
  113. __vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
  114. {
  115. return NULL;
  116. }
  117. static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
  118. {
  119. BUG();
  120. return NULL;
  121. }
  122. static inline u16 vlan_dev_vlan_id(const struct net_device *dev)
  123. {
  124. BUG();
  125. return 0;
  126. }
  127. static inline bool vlan_do_receive(struct sk_buff **skb)
  128. {
  129. if ((*skb)->vlan_tci & VLAN_VID_MASK)
  130. (*skb)->pkt_type = PACKET_OTHERHOST;
  131. return false;
  132. }
  133. static inline struct sk_buff *vlan_untag(struct sk_buff *skb)
  134. {
  135. return skb;
  136. }
  137. #endif
  138. /**
  139. * vlan_insert_tag - regular VLAN tag inserting
  140. * @skb: skbuff to tag
  141. * @vlan_tci: VLAN TCI to insert
  142. *
  143. * Inserts the VLAN tag into @skb as part of the payload
  144. * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
  145. *
  146. * Following the skb_unshare() example, in case of error, the calling function
  147. * doesn't have to worry about freeing the original skb.
  148. *
  149. * Does not change skb->protocol so this function can be used during receive.
  150. */
  151. static inline struct sk_buff *vlan_insert_tag(struct sk_buff *skb, u16 vlan_tci)
  152. {
  153. struct vlan_ethhdr *veth;
  154. if (skb_cow_head(skb, VLAN_HLEN) < 0) {
  155. kfree_skb(skb);
  156. return NULL;
  157. }
  158. veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
  159. /* Move the mac addresses to the beginning of the new header. */
  160. memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
  161. skb->mac_header -= VLAN_HLEN;
  162. /* first, the ethernet type */
  163. veth->h_vlan_proto = htons(ETH_P_8021Q);
  164. /* now, the TCI */
  165. veth->h_vlan_TCI = htons(vlan_tci);
  166. return skb;
  167. }
  168. /**
  169. * __vlan_put_tag - regular VLAN tag inserting
  170. * @skb: skbuff to tag
  171. * @vlan_tci: VLAN TCI to insert
  172. *
  173. * Inserts the VLAN tag into @skb as part of the payload
  174. * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
  175. *
  176. * Following the skb_unshare() example, in case of error, the calling function
  177. * doesn't have to worry about freeing the original skb.
  178. */
  179. static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
  180. {
  181. skb = vlan_insert_tag(skb, vlan_tci);
  182. if (skb)
  183. skb->protocol = htons(ETH_P_8021Q);
  184. return skb;
  185. }
  186. /**
  187. * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
  188. * @skb: skbuff to tag
  189. * @vlan_tci: VLAN TCI to insert
  190. *
  191. * Puts the VLAN TCI in @skb->vlan_tci and lets the device do the rest
  192. */
  193. static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb,
  194. u16 vlan_tci)
  195. {
  196. skb->vlan_tci = VLAN_TAG_PRESENT | vlan_tci;
  197. return skb;
  198. }
  199. #define HAVE_VLAN_PUT_TAG
  200. /**
  201. * vlan_put_tag - inserts VLAN tag according to device features
  202. * @skb: skbuff to tag
  203. * @vlan_tci: VLAN TCI to insert
  204. *
  205. * Assumes skb->dev is the target that will xmit this frame.
  206. * Returns a VLAN tagged skb.
  207. */
  208. static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, u16 vlan_tci)
  209. {
  210. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  211. return __vlan_hwaccel_put_tag(skb, vlan_tci);
  212. } else {
  213. return __vlan_put_tag(skb, vlan_tci);
  214. }
  215. }
  216. /**
  217. * __vlan_get_tag - get the VLAN ID that is part of the payload
  218. * @skb: skbuff to query
  219. * @vlan_tci: buffer to store vlaue
  220. *
  221. * Returns error if the skb is not of VLAN type
  222. */
  223. static inline int __vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  224. {
  225. struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
  226. if (veth->h_vlan_proto != htons(ETH_P_8021Q)) {
  227. return -EINVAL;
  228. }
  229. *vlan_tci = ntohs(veth->h_vlan_TCI);
  230. return 0;
  231. }
  232. /**
  233. * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
  234. * @skb: skbuff to query
  235. * @vlan_tci: buffer to store vlaue
  236. *
  237. * Returns error if @skb->vlan_tci is not set correctly
  238. */
  239. static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
  240. u16 *vlan_tci)
  241. {
  242. if (vlan_tx_tag_present(skb)) {
  243. *vlan_tci = vlan_tx_tag_get(skb);
  244. return 0;
  245. } else {
  246. *vlan_tci = 0;
  247. return -EINVAL;
  248. }
  249. }
  250. #define HAVE_VLAN_GET_TAG
  251. /**
  252. * vlan_get_tag - get the VLAN ID from the skb
  253. * @skb: skbuff to query
  254. * @vlan_tci: buffer to store vlaue
  255. *
  256. * Returns error if the skb is not VLAN tagged
  257. */
  258. static inline int vlan_get_tag(const struct sk_buff *skb, u16 *vlan_tci)
  259. {
  260. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  261. return __vlan_hwaccel_get_tag(skb, vlan_tci);
  262. } else {
  263. return __vlan_get_tag(skb, vlan_tci);
  264. }
  265. }
  266. /**
  267. * vlan_get_protocol - get protocol EtherType.
  268. * @skb: skbuff to query
  269. *
  270. * Returns the EtherType of the packet, regardless of whether it is
  271. * vlan encapsulated (normal or hardware accelerated) or not.
  272. */
  273. static inline __be16 vlan_get_protocol(const struct sk_buff *skb)
  274. {
  275. __be16 protocol = 0;
  276. if (vlan_tx_tag_present(skb) ||
  277. skb->protocol != cpu_to_be16(ETH_P_8021Q))
  278. protocol = skb->protocol;
  279. else {
  280. __be16 proto, *protop;
  281. protop = skb_header_pointer(skb, offsetof(struct vlan_ethhdr,
  282. h_vlan_encapsulated_proto),
  283. sizeof(proto), &proto);
  284. if (likely(protop))
  285. protocol = *protop;
  286. }
  287. return protocol;
  288. }
  289. #endif /* __KERNEL__ */
  290. /* VLAN IOCTLs are found in sockios.h */
  291. /* Passed in vlan_ioctl_args structure to determine behaviour. */
  292. enum vlan_ioctl_cmds {
  293. ADD_VLAN_CMD,
  294. DEL_VLAN_CMD,
  295. SET_VLAN_INGRESS_PRIORITY_CMD,
  296. SET_VLAN_EGRESS_PRIORITY_CMD,
  297. GET_VLAN_INGRESS_PRIORITY_CMD,
  298. GET_VLAN_EGRESS_PRIORITY_CMD,
  299. SET_VLAN_NAME_TYPE_CMD,
  300. SET_VLAN_FLAG_CMD,
  301. GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
  302. GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
  303. };
  304. enum vlan_flags {
  305. VLAN_FLAG_REORDER_HDR = 0x1,
  306. VLAN_FLAG_GVRP = 0x2,
  307. VLAN_FLAG_LOOSE_BINDING = 0x4,
  308. };
  309. enum vlan_name_types {
  310. VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */
  311. VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */
  312. VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */
  313. VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */
  314. VLAN_NAME_TYPE_HIGHEST
  315. };
  316. struct vlan_ioctl_args {
  317. int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
  318. char device1[24];
  319. union {
  320. char device2[24];
  321. int VID;
  322. unsigned int skb_priority;
  323. unsigned int name_type;
  324. unsigned int bind_type;
  325. unsigned int flag; /* Matches vlan_dev_info flags */
  326. } u;
  327. short vlan_qos;
  328. };
  329. #endif /* !(_LINUX_IF_VLAN_H_) */