xref: /openbmc/linux/net/mac80211/mesh.h (revision 483eb062)
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_path_flags - mac80211 mesh path flags
23  *
24  *
25  *
26  * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
27  * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
28  * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
29  *	number
30  * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
31  *	modified
32  * @MESH_PATH_RESOLVED: the mesh path can has been resolved
33  * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination
34  *	already queued up, waiting for the discovery process to start.
35  *
36  * MESH_PATH_RESOLVED is used by the mesh path timer to
37  * decide when to stop or cancel the mesh path discovery.
38  */
39 enum mesh_path_flags {
40 	MESH_PATH_ACTIVE =	BIT(0),
41 	MESH_PATH_RESOLVING =	BIT(1),
42 	MESH_PATH_SN_VALID =	BIT(2),
43 	MESH_PATH_FIXED	=	BIT(3),
44 	MESH_PATH_RESOLVED =	BIT(4),
45 	MESH_PATH_REQ_QUEUED =	BIT(5),
46 };
47 
48 /**
49  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
50  *
51  *
52  *
53  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
54  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
55  * to grow.
56  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
57  * grow
58  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
59  * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
60  * mesh nodes
61  * @MESH_WORK_MBSS_CHANGED: rebuild beacon and notify driver of BSS changes
62  */
63 enum mesh_deferred_task_flags {
64 	MESH_WORK_HOUSEKEEPING,
65 	MESH_WORK_GROW_MPATH_TABLE,
66 	MESH_WORK_GROW_MPP_TABLE,
67 	MESH_WORK_ROOT,
68 	MESH_WORK_DRIFT_ADJUST,
69 	MESH_WORK_MBSS_CHANGED,
70 };
71 
72 /**
73  * struct mesh_path - mac80211 mesh path structure
74  *
75  * @dst: mesh path destination mac address
76  * @sdata: mesh subif
77  * @next_hop: mesh neighbor to which frames for this destination will be
78  *	forwarded
79  * @timer: mesh path discovery timer
80  * @frame_queue: pending queue for frames sent to this destination while the
81  *	path is unresolved
82  * @sn: target sequence number
83  * @metric: current metric to this destination
84  * @hop_count: hops to destination
85  * @exp_time: in jiffies, when the path will expire or when it expired
86  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
87  *	retry
88  * @discovery_retries: number of discovery retries
89  * @flags: mesh path flags, as specified on &enum mesh_path_flags
90  * @state_lock: mesh path state lock used to protect changes to the
91  * mpath itself.  No need to take this lock when adding or removing
92  * an mpath to a hash bucket on a path table.
93  * @rann_snd_addr: the RANN sender address
94  * @rann_metric: the aggregated path metric towards the root node
95  * @last_preq_to_root: Timestamp of last PREQ sent to root
96  * @is_root: the destination station of this path is a root node
97  * @is_gate: the destination station of this path is a mesh gate
98  *
99  *
100  * The combination of dst and sdata is unique in the mesh path table. Since the
101  * next_hop STA is only protected by RCU as well, deleting the STA must also
102  * remove/substitute the mesh_path structure and wait until that is no longer
103  * reachable before destroying the STA completely.
104  */
105 struct mesh_path {
106 	u8 dst[ETH_ALEN];
107 	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */
108 	struct ieee80211_sub_if_data *sdata;
109 	struct sta_info __rcu *next_hop;
110 	struct timer_list timer;
111 	struct sk_buff_head frame_queue;
112 	struct rcu_head rcu;
113 	u32 sn;
114 	u32 metric;
115 	u8 hop_count;
116 	unsigned long exp_time;
117 	u32 discovery_timeout;
118 	u8 discovery_retries;
119 	enum mesh_path_flags flags;
120 	spinlock_t state_lock;
121 	u8 rann_snd_addr[ETH_ALEN];
122 	u32 rann_metric;
123 	unsigned long last_preq_to_root;
124 	bool is_root;
125 	bool is_gate;
126 };
127 
128 /**
129  * struct mesh_table
130  *
131  * @hash_buckets: array of hash buckets of the table
132  * @hashwlock: array of locks to protect write operations, one per bucket
133  * @hash_mask: 2^size_order - 1, used to compute hash idx
134  * @hash_rnd: random value used for hash computations
135  * @entries: number of entries in the table
136  * @free_node: function to free nodes of the table
137  * @copy_node: function to copy nodes of the table
138  * @size_order: determines size of the table, there will be 2^size_order hash
139  *	buckets
140  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
141  *	reached, the table will grow
142  * @known_gates: list of known mesh gates and their mpaths by the station. The
143  * gate's mpath may or may not be resolved and active.
144  *
145  * rcu_head: RCU head to free the table
146  */
147 struct mesh_table {
148 	/* Number of buckets will be 2^N */
149 	struct hlist_head *hash_buckets;
150 	spinlock_t *hashwlock;		/* One per bucket, for add/del */
151 	unsigned int hash_mask;		/* (2^size_order) - 1 */
152 	__u32 hash_rnd;			/* Used for hash generation */
153 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
154 	void (*free_node) (struct hlist_node *p, bool free_leafs);
155 	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
156 	int size_order;
157 	int mean_chain_len;
158 	struct hlist_head *known_gates;
159 	spinlock_t gates_lock;
160 
161 	struct rcu_head rcu_head;
162 };
163 
164 /* Recent multicast cache */
165 /* RMC_BUCKETS must be a power of 2, maximum 256 */
166 #define RMC_BUCKETS		256
167 #define RMC_QUEUE_MAX_LEN	4
168 #define RMC_TIMEOUT		(3 * HZ)
169 
170 /**
171  * struct rmc_entry - entry in the Recent Multicast Cache
172  *
173  * @seqnum: mesh sequence number of the frame
174  * @exp_time: expiration time of the entry, in jiffies
175  * @sa: source address of the frame
176  *
177  * The Recent Multicast Cache keeps track of the latest multicast frames that
178  * have been received by a mesh interface and discards received multicast frames
179  * that are found in the cache.
180  */
181 struct rmc_entry {
182 	struct list_head list;
183 	u32 seqnum;
184 	unsigned long exp_time;
185 	u8 sa[ETH_ALEN];
186 };
187 
188 struct mesh_rmc {
189 	struct list_head bucket[RMC_BUCKETS];
190 	u32 idx_mask;
191 };
192 
193 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
194 
195 #define MESH_PATH_EXPIRE (600 * HZ)
196 
197 /* Default maximum number of plinks per interface */
198 #define MESH_MAX_PLINKS		256
199 
200 /* Maximum number of paths per interface */
201 #define MESH_MAX_MPATHS		1024
202 
203 /* Number of frames buffered per destination for unresolved destinations */
204 #define MESH_FRAME_QUEUE_LEN	10
205 
206 /* Public interfaces */
207 /* Various */
208 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
209 				  const u8 *da, const u8 *sa);
210 int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
211 			      struct ieee80211s_hdr *meshhdr,
212 			      const char *addr4or5, const char *addr6);
213 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
214 		   const u8 *addr, struct ieee80211s_hdr *mesh_hdr);
215 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
216 			struct ieee802_11_elems *ie);
217 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
218 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
219 			 struct sk_buff *skb);
220 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata,
221 		       struct sk_buff *skb);
222 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata,
223 		    struct sk_buff *skb);
224 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
225 			struct sk_buff *skb);
226 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
227 		       struct sk_buff *skb);
228 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
229 			struct sk_buff *skb);
230 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
231 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
232 void ieee80211s_init(void);
233 void ieee80211s_update_metric(struct ieee80211_local *local,
234 			      struct sta_info *sta, struct sk_buff *skb);
235 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
236 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
237 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
238 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
239 const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
240 /* wrapper for ieee80211_bss_info_change_notify() */
241 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
242 				       u32 changed);
243 
244 /* mesh power save */
245 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata);
246 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
247 				   enum nl80211_mesh_power_mode pm);
248 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
249 				   struct sta_info *sta,
250 				   struct ieee80211_hdr *hdr);
251 void ieee80211_mps_sta_status_update(struct sta_info *sta);
252 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
253 				    struct ieee80211_hdr *hdr);
254 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
255 				    bool tx, bool acked);
256 void ieee80211_mps_frame_release(struct sta_info *sta,
257 				 struct ieee802_11_elems *elems);
258 
259 /* Mesh paths */
260 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
261 			struct sk_buff *skb);
262 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
263 			 struct sk_buff *skb);
264 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
265 struct mesh_path *mesh_path_lookup(struct ieee80211_sub_if_data *sdata,
266 				   const u8 *dst);
267 struct mesh_path *mpp_path_lookup(struct ieee80211_sub_if_data *sdata,
268 				  const u8 *dst);
269 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
270 		 const u8 *dst, const u8 *mpp);
271 struct mesh_path *
272 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
273 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
274 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
275 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
276 			    struct ieee80211_mgmt *mgmt, size_t len);
277 struct mesh_path *
278 mesh_path_add(struct ieee80211_sub_if_data *sdata, const u8 *dst);
279 
280 int mesh_path_add_gate(struct mesh_path *mpath);
281 int mesh_path_send_to_gates(struct mesh_path *mpath);
282 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
283 
284 /* Mesh plinks */
285 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
286 			   u8 *hw_addr, struct ieee802_11_elems *ie);
287 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
288 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
289 void mesh_plink_broken(struct sta_info *sta);
290 u32 mesh_plink_deactivate(struct sta_info *sta);
291 u32 mesh_plink_open(struct sta_info *sta);
292 u32 mesh_plink_block(struct sta_info *sta);
293 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
294 			 struct ieee80211_mgmt *mgmt, size_t len,
295 			 struct ieee80211_rx_status *rx_status);
296 void mesh_sta_cleanup(struct sta_info *sta);
297 
298 /* Private interfaces */
299 /* Mesh tables */
300 void mesh_mpath_table_grow(void);
301 void mesh_mpp_table_grow(void);
302 /* Mesh paths */
303 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
304 		       u8 ttl, const u8 *target, u32 target_sn,
305 		       u16 target_rcode, const u8 *ra);
306 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
307 void mesh_path_flush_pending(struct mesh_path *mpath);
308 void mesh_path_tx_pending(struct mesh_path *mpath);
309 int mesh_pathtbl_init(void);
310 void mesh_pathtbl_unregister(void);
311 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr);
312 void mesh_path_timer(unsigned long data);
313 void mesh_path_flush_by_nexthop(struct sta_info *sta);
314 void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
315 			     struct sk_buff *skb);
316 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
317 
318 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
319 extern int mesh_paths_generation;
320 
321 #ifdef CONFIG_MAC80211_MESH
322 static inline
323 u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
324 {
325 	atomic_inc(&sdata->u.mesh.estab_plinks);
326 	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
327 }
328 
329 static inline
330 u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
331 {
332 	atomic_dec(&sdata->u.mesh.estab_plinks);
333 	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
334 }
335 
336 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
337 {
338 	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
339 	       atomic_read(&sdata->u.mesh.estab_plinks);
340 }
341 
342 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
343 {
344 	return (min_t(long, mesh_plink_free_count(sdata),
345 		   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
346 }
347 
348 static inline void mesh_path_activate(struct mesh_path *mpath)
349 {
350 	mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
351 }
352 
353 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
354 {
355 	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
356 }
357 
358 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
359 
360 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
361 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
362 void ieee80211s_stop(void);
363 #else
364 static inline void
365 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
366 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
367 { return false; }
368 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
369 {}
370 static inline void ieee80211s_stop(void) {}
371 #endif
372 
373 #endif /* IEEE80211S_H */
374