if_vlan.h 12 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. /* externally defined structs */
  16. struct vlan_group;
  17. struct net_device;
  18. struct packet_type;
  19. struct vlan_collection;
  20. struct vlan_dev_info;
  21. struct hlist_node;
  22. #include <linux/netdevice.h>
  23. #include <linux/etherdevice.h>
  24. #define VLAN_HLEN 4 /* The additional bytes (on top of the Ethernet header)
  25. * that VLAN requires.
  26. */
  27. #define VLAN_ETH_ALEN 6 /* Octets in one ethernet addr */
  28. #define VLAN_ETH_HLEN 18 /* Total octets in header. */
  29. #define VLAN_ETH_ZLEN 64 /* Min. octets in frame sans FCS */
  30. /*
  31. * According to 802.3ac, the packet can be 4 bytes longer. --Klika Jan
  32. */
  33. #define VLAN_ETH_DATA_LEN 1500 /* Max. octets in payload */
  34. #define VLAN_ETH_FRAME_LEN 1518 /* Max. octets in frame sans FCS */
  35. struct vlan_ethhdr {
  36. unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
  37. unsigned char h_source[ETH_ALEN]; /* source ether addr */
  38. __be16 h_vlan_proto; /* Should always be 0x8100 */
  39. __be16 h_vlan_TCI; /* Encapsulates priority and VLAN ID */
  40. __be16 h_vlan_encapsulated_proto; /* packet type ID field (or len) */
  41. };
  42. #include <linux/skbuff.h>
  43. static inline struct vlan_ethhdr *vlan_eth_hdr(const struct sk_buff *skb)
  44. {
  45. return (struct vlan_ethhdr *)skb->mac.raw;
  46. }
  47. struct vlan_hdr {
  48. __be16 h_vlan_TCI; /* Encapsulates priority and VLAN ID */
  49. __be16 h_vlan_encapsulated_proto; /* packet type ID field (or len) */
  50. };
  51. #define VLAN_VID_MASK 0xfff
  52. /* found in socket.c */
  53. extern void vlan_ioctl_set(int (*hook)(void __user *));
  54. #define VLAN_NAME "vlan"
  55. /* if this changes, algorithm will have to be reworked because this
  56. * depends on completely exhausting the VLAN identifier space. Thus
  57. * it gives constant time look-up, but in many cases it wastes memory.
  58. */
  59. #define VLAN_GROUP_ARRAY_LEN 4096
  60. #define VLAN_GROUP_ARRAY_SPLIT_PARTS 8
  61. #define VLAN_GROUP_ARRAY_PART_LEN (VLAN_GROUP_ARRAY_LEN/VLAN_GROUP_ARRAY_SPLIT_PARTS)
  62. struct vlan_group {
  63. int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
  64. struct hlist_node hlist; /* linked list */
  65. struct net_device **vlan_devices_arrays[VLAN_GROUP_ARRAY_SPLIT_PARTS];
  66. struct rcu_head rcu;
  67. };
  68. static inline struct net_device *vlan_group_get_device(struct vlan_group *vg, int vlan_id)
  69. {
  70. struct net_device **array;
  71. array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  72. return array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN];
  73. }
  74. static inline void vlan_group_set_device(struct vlan_group *vg, int vlan_id,
  75. struct net_device *dev)
  76. {
  77. struct net_device **array;
  78. if (!vg)
  79. return;
  80. array = vg->vlan_devices_arrays[vlan_id / VLAN_GROUP_ARRAY_PART_LEN];
  81. array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
  82. }
  83. struct vlan_priority_tci_mapping {
  84. unsigned long priority;
  85. unsigned short vlan_qos; /* This should be shifted when first set, so we only do it
  86. * at provisioning time.
  87. * ((skb->priority << 13) & 0xE000)
  88. */
  89. struct vlan_priority_tci_mapping *next;
  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. unsigned short vlan_id; /* The VLAN Identifier for this interface. */
  99. unsigned short flags; /* (1 << 0) re_order_header This option will cause the
  100. * VLAN code to move around the ethernet header on
  101. * ingress to make the skb look **exactly** like it
  102. * came in from an ethernet port. This destroys some of
  103. * the VLAN information in the skb, but it fixes programs
  104. * like DHCP that use packet-filtering and don't understand
  105. * 802.1Q
  106. */
  107. struct dev_mc_list *old_mc_list; /* old multi-cast list for the VLAN interface..
  108. * we save this so we can tell what changes were
  109. * made, in order to feed the right changes down
  110. * to the real hardware...
  111. */
  112. int old_allmulti; /* similar to above. */
  113. int old_promiscuity; /* similar to above. */
  114. struct net_device *real_dev; /* the underlying device/interface */
  115. struct proc_dir_entry *dent; /* Holds the proc data */
  116. unsigned long cnt_inc_headroom_on_tx; /* How many times did we have to grow the skb on TX. */
  117. unsigned long cnt_encap_on_xmit; /* How many times did we have to encapsulate the skb on TX. */
  118. struct net_device_stats dev_stats; /* Device stats (rx-bytes, tx-pkts, etc...) */
  119. };
  120. #define VLAN_DEV_INFO(x) ((struct vlan_dev_info *)(x->priv))
  121. /* inline functions */
  122. static inline struct net_device_stats *vlan_dev_get_stats(struct net_device *dev)
  123. {
  124. return &(VLAN_DEV_INFO(dev)->dev_stats);
  125. }
  126. static inline __u32 vlan_get_ingress_priority(struct net_device *dev,
  127. unsigned short vlan_tag)
  128. {
  129. struct vlan_dev_info *vip = VLAN_DEV_INFO(dev);
  130. return vip->ingress_priority_map[(vlan_tag >> 13) & 0x7];
  131. }
  132. /* VLAN tx hw acceleration helpers. */
  133. struct vlan_skb_tx_cookie {
  134. u32 magic;
  135. u32 vlan_tag;
  136. };
  137. #define VLAN_TX_COOKIE_MAGIC 0x564c414e /* "VLAN" in ascii. */
  138. #define VLAN_TX_SKB_CB(__skb) ((struct vlan_skb_tx_cookie *)&((__skb)->cb[0]))
  139. #define vlan_tx_tag_present(__skb) \
  140. (VLAN_TX_SKB_CB(__skb)->magic == VLAN_TX_COOKIE_MAGIC)
  141. #define vlan_tx_tag_get(__skb) (VLAN_TX_SKB_CB(__skb)->vlan_tag)
  142. /* VLAN rx hw acceleration helper. This acts like netif_{rx,receive_skb}(). */
  143. static inline int __vlan_hwaccel_rx(struct sk_buff *skb,
  144. struct vlan_group *grp,
  145. unsigned short vlan_tag, int polling)
  146. {
  147. struct net_device_stats *stats;
  148. if (skb_bond_should_drop(skb)) {
  149. dev_kfree_skb_any(skb);
  150. return NET_RX_DROP;
  151. }
  152. skb->dev = vlan_group_get_device(grp, vlan_tag & VLAN_VID_MASK);
  153. if (skb->dev == NULL) {
  154. dev_kfree_skb_any(skb);
  155. /* Not NET_RX_DROP, this is not being dropped
  156. * due to congestion.
  157. */
  158. return 0;
  159. }
  160. skb->dev->last_rx = jiffies;
  161. stats = vlan_dev_get_stats(skb->dev);
  162. stats->rx_packets++;
  163. stats->rx_bytes += skb->len;
  164. skb->priority = vlan_get_ingress_priority(skb->dev, vlan_tag);
  165. switch (skb->pkt_type) {
  166. case PACKET_BROADCAST:
  167. break;
  168. case PACKET_MULTICAST:
  169. stats->multicast++;
  170. break;
  171. case PACKET_OTHERHOST:
  172. /* Our lower layer thinks this is not local, let's make sure.
  173. * This allows the VLAN to have a different MAC than the underlying
  174. * device, and still route correctly.
  175. */
  176. if (!compare_ether_addr(eth_hdr(skb)->h_dest,
  177. skb->dev->dev_addr))
  178. skb->pkt_type = PACKET_HOST;
  179. break;
  180. };
  181. return (polling ? netif_receive_skb(skb) : netif_rx(skb));
  182. }
  183. static inline int vlan_hwaccel_rx(struct sk_buff *skb,
  184. struct vlan_group *grp,
  185. unsigned short vlan_tag)
  186. {
  187. return __vlan_hwaccel_rx(skb, grp, vlan_tag, 0);
  188. }
  189. static inline int vlan_hwaccel_receive_skb(struct sk_buff *skb,
  190. struct vlan_group *grp,
  191. unsigned short vlan_tag)
  192. {
  193. return __vlan_hwaccel_rx(skb, grp, vlan_tag, 1);
  194. }
  195. /**
  196. * __vlan_put_tag - regular VLAN tag inserting
  197. * @skb: skbuff to tag
  198. * @tag: VLAN tag to insert
  199. *
  200. * Inserts the VLAN tag into @skb as part of the payload
  201. * Returns a VLAN tagged skb. If a new skb is created, @skb is freed.
  202. *
  203. * Following the skb_unshare() example, in case of error, the calling function
  204. * doesn't have to worry about freeing the original skb.
  205. */
  206. static inline struct sk_buff *__vlan_put_tag(struct sk_buff *skb, unsigned short tag)
  207. {
  208. struct vlan_ethhdr *veth;
  209. if (skb_headroom(skb) < VLAN_HLEN) {
  210. struct sk_buff *sk_tmp = skb;
  211. skb = skb_realloc_headroom(sk_tmp, VLAN_HLEN);
  212. kfree_skb(sk_tmp);
  213. if (!skb) {
  214. printk(KERN_ERR "vlan: failed to realloc headroom\n");
  215. return NULL;
  216. }
  217. } else {
  218. skb = skb_unshare(skb, GFP_ATOMIC);
  219. if (!skb) {
  220. printk(KERN_ERR "vlan: failed to unshare skbuff\n");
  221. return NULL;
  222. }
  223. }
  224. veth = (struct vlan_ethhdr *)skb_push(skb, VLAN_HLEN);
  225. /* Move the mac addresses to the beginning of the new header. */
  226. memmove(skb->data, skb->data + VLAN_HLEN, 2 * VLAN_ETH_ALEN);
  227. /* first, the ethernet type */
  228. veth->h_vlan_proto = __constant_htons(ETH_P_8021Q);
  229. /* now, the tag */
  230. veth->h_vlan_TCI = htons(tag);
  231. skb->protocol = __constant_htons(ETH_P_8021Q);
  232. skb->mac.raw -= VLAN_HLEN;
  233. skb->nh.raw -= VLAN_HLEN;
  234. return skb;
  235. }
  236. /**
  237. * __vlan_hwaccel_put_tag - hardware accelerated VLAN inserting
  238. * @skb: skbuff to tag
  239. * @tag: VLAN tag to insert
  240. *
  241. * Puts the VLAN tag in @skb->cb[] and lets the device do the rest
  242. */
  243. static inline struct sk_buff *__vlan_hwaccel_put_tag(struct sk_buff *skb, unsigned short tag)
  244. {
  245. struct vlan_skb_tx_cookie *cookie;
  246. cookie = VLAN_TX_SKB_CB(skb);
  247. cookie->magic = VLAN_TX_COOKIE_MAGIC;
  248. cookie->vlan_tag = tag;
  249. return skb;
  250. }
  251. #define HAVE_VLAN_PUT_TAG
  252. /**
  253. * vlan_put_tag - inserts VLAN tag according to device features
  254. * @skb: skbuff to tag
  255. * @tag: VLAN tag to insert
  256. *
  257. * Assumes skb->dev is the target that will xmit this frame.
  258. * Returns a VLAN tagged skb.
  259. */
  260. static inline struct sk_buff *vlan_put_tag(struct sk_buff *skb, unsigned short tag)
  261. {
  262. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  263. return __vlan_hwaccel_put_tag(skb, tag);
  264. } else {
  265. return __vlan_put_tag(skb, tag);
  266. }
  267. }
  268. /**
  269. * __vlan_get_tag - get the VLAN ID that is part of the payload
  270. * @skb: skbuff to query
  271. * @tag: buffer to store vlaue
  272. *
  273. * Returns error if the skb is not of VLAN type
  274. */
  275. static inline int __vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
  276. {
  277. struct vlan_ethhdr *veth = (struct vlan_ethhdr *)skb->data;
  278. if (veth->h_vlan_proto != __constant_htons(ETH_P_8021Q)) {
  279. return -EINVAL;
  280. }
  281. *tag = ntohs(veth->h_vlan_TCI);
  282. return 0;
  283. }
  284. /**
  285. * __vlan_hwaccel_get_tag - get the VLAN ID that is in @skb->cb[]
  286. * @skb: skbuff to query
  287. * @tag: buffer to store vlaue
  288. *
  289. * Returns error if @skb->cb[] is not set correctly
  290. */
  291. static inline int __vlan_hwaccel_get_tag(struct sk_buff *skb, unsigned short *tag)
  292. {
  293. struct vlan_skb_tx_cookie *cookie;
  294. cookie = VLAN_TX_SKB_CB(skb);
  295. if (cookie->magic == VLAN_TX_COOKIE_MAGIC) {
  296. *tag = cookie->vlan_tag;
  297. return 0;
  298. } else {
  299. *tag = 0;
  300. return -EINVAL;
  301. }
  302. }
  303. #define HAVE_VLAN_GET_TAG
  304. /**
  305. * vlan_get_tag - get the VLAN ID from the skb
  306. * @skb: skbuff to query
  307. * @tag: buffer to store vlaue
  308. *
  309. * Returns error if the skb is not VLAN tagged
  310. */
  311. static inline int vlan_get_tag(struct sk_buff *skb, unsigned short *tag)
  312. {
  313. if (skb->dev->features & NETIF_F_HW_VLAN_TX) {
  314. return __vlan_hwaccel_get_tag(skb, tag);
  315. } else {
  316. return __vlan_get_tag(skb, tag);
  317. }
  318. }
  319. #endif /* __KERNEL__ */
  320. /* VLAN IOCTLs are found in sockios.h */
  321. /* Passed in vlan_ioctl_args structure to determine behaviour. */
  322. enum vlan_ioctl_cmds {
  323. ADD_VLAN_CMD,
  324. DEL_VLAN_CMD,
  325. SET_VLAN_INGRESS_PRIORITY_CMD,
  326. SET_VLAN_EGRESS_PRIORITY_CMD,
  327. GET_VLAN_INGRESS_PRIORITY_CMD,
  328. GET_VLAN_EGRESS_PRIORITY_CMD,
  329. SET_VLAN_NAME_TYPE_CMD,
  330. SET_VLAN_FLAG_CMD,
  331. GET_VLAN_REALDEV_NAME_CMD, /* If this works, you know it's a VLAN device, btw */
  332. GET_VLAN_VID_CMD /* Get the VID of this VLAN (specified by name) */
  333. };
  334. enum vlan_name_types {
  335. VLAN_NAME_TYPE_PLUS_VID, /* Name will look like: vlan0005 */
  336. VLAN_NAME_TYPE_RAW_PLUS_VID, /* name will look like: eth1.0005 */
  337. VLAN_NAME_TYPE_PLUS_VID_NO_PAD, /* Name will look like: vlan5 */
  338. VLAN_NAME_TYPE_RAW_PLUS_VID_NO_PAD, /* Name will look like: eth0.5 */
  339. VLAN_NAME_TYPE_HIGHEST
  340. };
  341. struct vlan_ioctl_args {
  342. int cmd; /* Should be one of the vlan_ioctl_cmds enum above. */
  343. char device1[24];
  344. union {
  345. char device2[24];
  346. int VID;
  347. unsigned int skb_priority;
  348. unsigned int name_type;
  349. unsigned int bind_type;
  350. unsigned int flag; /* Matches vlan_dev_info flags */
  351. } u;
  352. short vlan_qos;
  353. };
  354. #endif /* !(_LINUX_IF_VLAN_H_) */