xref: /linux/net/mac80211/mesh.h (revision 5051c94bb3998ff24bf07ae3b72dca30f85962f8)
1 /*
2  * Copyright (c) 2008, 2009 open80211s Ltd.
3  * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
4  *             Javier Cardona <javier@cozybit.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #ifndef IEEE80211S_H
12 #define IEEE80211S_H
13 
14 #include <linux/types.h>
15 #include <linux/jhash.h>
16 #include "ieee80211_i.h"
17 
18 
19 /* Data structures */
20 
21 /**
22  * enum mesh_config_capab_flags - mesh config IE capability flags
23  *
24  * @MESHCONF_CAPAB_ACCEPT_PLINKS: STA is willing to establish
25  * additional mesh peerings with other mesh STAs
26  * @MESHCONF_CAPAB_FORWARDING: the STA forwards MSDUs
27  * @MESHCONF_CAPAB_TBTT_ADJUSTING: TBTT adjustment procedure is ongoing
28  */
29 enum mesh_config_capab_flags {
30 	MESHCONF_CAPAB_ACCEPT_PLINKS = BIT(0),
31 	MESHCONF_CAPAB_FORWARDING = BIT(3),
32 	MESHCONF_CAPAB_TBTT_ADJUSTING = BIT(5),
33 };
34 
35 /**
36  * enum mesh_path_flags - mac80211 mesh path flags
37  *
38  *
39  *
40  * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
41  * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
42  * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
43  * 	number
44  * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
45  * 	modified
46  * @MESH_PATH_RESOLVED: the mesh path can has been resolved
47  * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination
48  * already queued up, waiting for the discovery process to start.
49  *
50  * MESH_PATH_RESOLVED is used by the mesh path timer to
51  * decide when to stop or cancel the mesh path discovery.
52  */
53 enum mesh_path_flags {
54 	MESH_PATH_ACTIVE =	BIT(0),
55 	MESH_PATH_RESOLVING =	BIT(1),
56 	MESH_PATH_SN_VALID =	BIT(2),
57 	MESH_PATH_FIXED	=	BIT(3),
58 	MESH_PATH_RESOLVED =	BIT(4),
59 	MESH_PATH_REQ_QUEUED =	BIT(5),
60 };
61 
62 /**
63  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
64  *
65  *
66  *
67  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
68  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
69  * to grow.
70  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
71  * grow
72  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
73  * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
74  * mesh nodes
75  */
76 enum mesh_deferred_task_flags {
77 	MESH_WORK_HOUSEKEEPING,
78 	MESH_WORK_GROW_MPATH_TABLE,
79 	MESH_WORK_GROW_MPP_TABLE,
80 	MESH_WORK_ROOT,
81 	MESH_WORK_DRIFT_ADJUST,
82 };
83 
84 /**
85  * struct mesh_path - mac80211 mesh path structure
86  *
87  * @dst: mesh path destination mac address
88  * @sdata: mesh subif
89  * @next_hop: mesh neighbor to which frames for this destination will be
90  * 	forwarded
91  * @timer: mesh path discovery timer
92  * @frame_queue: pending queue for frames sent to this destination while the
93  * 	path is unresolved
94  * @sn: target sequence number
95  * @metric: current metric to this destination
96  * @hop_count: hops to destination
97  * @exp_time: in jiffies, when the path will expire or when it expired
98  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
99  * 	retry
100  * @discovery_retries: number of discovery retries
101  * @flags: mesh path flags, as specified on &enum mesh_path_flags
102  * @state_lock: mesh path state lock used to protect changes to the
103  * mpath itself.  No need to take this lock when adding or removing
104  * an mpath to a hash bucket on a path table.
105  * @rann_snd_addr: the RANN sender address
106  * @rann_metric: the aggregated path metric towards the root node
107  * @is_root: the destination station of this path is a root node
108  * @is_gate: the destination station of this path is a mesh gate
109  *
110  *
111  * The combination of dst and sdata is unique in the mesh path table. Since the
112  * next_hop STA is only protected by RCU as well, deleting the STA must also
113  * remove/substitute the mesh_path structure and wait until that is no longer
114  * reachable before destroying the STA completely.
115  */
116 struct mesh_path {
117 	u8 dst[ETH_ALEN];
118 	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */
119 	struct ieee80211_sub_if_data *sdata;
120 	struct sta_info __rcu *next_hop;
121 	struct timer_list timer;
122 	struct sk_buff_head frame_queue;
123 	struct rcu_head rcu;
124 	u32 sn;
125 	u32 metric;
126 	u8 hop_count;
127 	unsigned long exp_time;
128 	u32 discovery_timeout;
129 	u8 discovery_retries;
130 	enum mesh_path_flags flags;
131 	spinlock_t state_lock;
132 	u8 rann_snd_addr[ETH_ALEN];
133 	u32 rann_metric;
134 	bool is_root;
135 	bool is_gate;
136 };
137 
138 /**
139  * struct mesh_table
140  *
141  * @hash_buckets: array of hash buckets of the table
142  * @hashwlock: array of locks to protect write operations, one per bucket
143  * @hash_mask: 2^size_order - 1, used to compute hash idx
144  * @hash_rnd: random value used for hash computations
145  * @entries: number of entries in the table
146  * @free_node: function to free nodes of the table
147  * @copy_node: function to copy nodes of the table
148  * @size_order: determines size of the table, there will be 2^size_order hash
149  *	buckets
150  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
151  *	reached, the table will grow
152  * @known_gates: list of known mesh gates and their mpaths by the station. The
153  * gate's mpath may or may not be resolved and active.
154  *
155  * rcu_head: RCU head to free the table
156  */
157 struct mesh_table {
158 	/* Number of buckets will be 2^N */
159 	struct hlist_head *hash_buckets;
160 	spinlock_t *hashwlock;		/* One per bucket, for add/del */
161 	unsigned int hash_mask;		/* (2^size_order) - 1 */
162 	__u32 hash_rnd;			/* Used for hash generation */
163 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
164 	void (*free_node) (struct hlist_node *p, bool free_leafs);
165 	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
166 	int size_order;
167 	int mean_chain_len;
168 	struct hlist_head *known_gates;
169 	spinlock_t gates_lock;
170 
171 	struct rcu_head rcu_head;
172 };
173 
174 /* Recent multicast cache */
175 /* RMC_BUCKETS must be a power of 2, maximum 256 */
176 #define RMC_BUCKETS		256
177 #define RMC_QUEUE_MAX_LEN	4
178 #define RMC_TIMEOUT		(3 * HZ)
179 
180 /**
181  * struct rmc_entry - entry in the Recent Multicast Cache
182  *
183  * @seqnum: mesh sequence number of the frame
184  * @exp_time: expiration time of the entry, in jiffies
185  * @sa: source address of the frame
186  *
187  * The Recent Multicast Cache keeps track of the latest multicast frames that
188  * have been received by a mesh interface and discards received multicast frames
189  * that are found in the cache.
190  */
191 struct rmc_entry {
192 	struct list_head list;
193 	u32 seqnum;
194 	unsigned long exp_time;
195 	u8 sa[ETH_ALEN];
196 };
197 
198 struct mesh_rmc {
199 	struct rmc_entry bucket[RMC_BUCKETS];
200 	u32 idx_mask;
201 };
202 
203 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
204 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
205 
206 #define MESH_DEFAULT_BEACON_INTERVAL		1000 	/* in 1024 us units */
207 
208 #define MESH_PATH_EXPIRE (600 * HZ)
209 
210 /* Default maximum number of plinks per interface */
211 #define MESH_MAX_PLINKS		256
212 
213 /* Maximum number of paths per interface */
214 #define MESH_MAX_MPATHS		1024
215 
216 /* Public interfaces */
217 /* Various */
218 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
219 				  const u8 *da, const u8 *sa);
220 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
221 		struct ieee80211_sub_if_data *sdata, char *addr4or5,
222 		char *addr6);
223 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
224 		struct ieee80211_sub_if_data *sdata);
225 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
226 			struct ieee802_11_elems *ie);
227 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
228 void mesh_mgmt_ies_add(struct sk_buff *skb,
229 		struct ieee80211_sub_if_data *sdata);
230 int mesh_add_meshconf_ie(struct sk_buff *skb,
231 			 struct ieee80211_sub_if_data *sdata);
232 int mesh_add_meshid_ie(struct sk_buff *skb,
233 		       struct ieee80211_sub_if_data *sdata);
234 int mesh_add_rsn_ie(struct sk_buff *skb,
235 		    struct ieee80211_sub_if_data *sdata);
236 int mesh_add_vendor_ies(struct sk_buff *skb,
237 			struct ieee80211_sub_if_data *sdata);
238 int mesh_add_ds_params_ie(struct sk_buff *skb,
239 			  struct ieee80211_sub_if_data *sdata);
240 int mesh_add_ht_cap_ie(struct sk_buff *skb,
241 		       struct ieee80211_sub_if_data *sdata);
242 int mesh_add_ht_oper_ie(struct sk_buff *skb,
243 			struct ieee80211_sub_if_data *sdata);
244 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
245 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
246 void ieee80211s_init(void);
247 void ieee80211s_update_metric(struct ieee80211_local *local,
248 		struct sta_info *stainfo, struct sk_buff *skb);
249 void ieee80211s_stop(void);
250 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
251 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
252 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
253 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
254 struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
255 
256 /* Mesh paths */
257 int mesh_nexthop_lookup(struct sk_buff *skb,
258 		struct ieee80211_sub_if_data *sdata);
259 int mesh_nexthop_resolve(struct sk_buff *skb,
260 			 struct ieee80211_sub_if_data *sdata);
261 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
262 struct mesh_path *mesh_path_lookup(u8 *dst,
263 		struct ieee80211_sub_if_data *sdata);
264 struct mesh_path *mpp_path_lookup(u8 *dst,
265 				  struct ieee80211_sub_if_data *sdata);
266 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
267 struct mesh_path *mesh_path_lookup_by_idx(int idx,
268 		struct ieee80211_sub_if_data *sdata);
269 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
270 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
271 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
272 		struct ieee80211_mgmt *mgmt, size_t len);
273 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
274 
275 int mesh_path_add_gate(struct mesh_path *mpath);
276 int mesh_path_send_to_gates(struct mesh_path *mpath);
277 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
278 /* Mesh plinks */
279 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
280 			   u8 *hw_addr,
281 			   struct ieee802_11_elems *ie);
282 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
283 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
284 void mesh_plink_broken(struct sta_info *sta);
285 void mesh_plink_deactivate(struct sta_info *sta);
286 int mesh_plink_open(struct sta_info *sta);
287 void mesh_plink_block(struct sta_info *sta);
288 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
289 			 struct ieee80211_mgmt *mgmt, size_t len,
290 			 struct ieee80211_rx_status *rx_status);
291 
292 /* Private interfaces */
293 /* Mesh tables */
294 void mesh_mpath_table_grow(void);
295 void mesh_mpp_table_grow(void);
296 /* Mesh paths */
297 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
298 		       const u8 *ra, struct ieee80211_sub_if_data *sdata);
299 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
300 void mesh_path_flush_pending(struct mesh_path *mpath);
301 void mesh_path_tx_pending(struct mesh_path *mpath);
302 int mesh_pathtbl_init(void);
303 void mesh_pathtbl_unregister(void);
304 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
305 void mesh_path_timer(unsigned long data);
306 void mesh_path_flush_by_nexthop(struct sta_info *sta);
307 void mesh_path_discard_frame(struct sk_buff *skb,
308 		struct ieee80211_sub_if_data *sdata);
309 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
310 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
311 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
312 
313 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
314 extern int mesh_paths_generation;
315 
316 #ifdef CONFIG_MAC80211_MESH
317 extern int mesh_allocated;
318 
319 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
320 {
321 	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
322 	       atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
323 }
324 
325 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
326 {
327 	return (min_t(long, mesh_plink_free_count(sdata),
328 		   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
329 }
330 
331 static inline void mesh_path_activate(struct mesh_path *mpath)
332 {
333 	mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
334 }
335 
336 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
337 {
338 	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
339 }
340 
341 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
342 
343 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
344 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
345 void mesh_plink_quiesce(struct sta_info *sta);
346 void mesh_plink_restart(struct sta_info *sta);
347 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
348 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
349 #else
350 #define mesh_allocated	0
351 static inline void
352 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
353 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
354 {}
355 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
356 {}
357 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
358 static inline void mesh_plink_restart(struct sta_info *sta) {}
359 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
360 { return false; }
361 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
362 {}
363 #endif
364 
365 #endif /* IEEE80211S_H */
366