xref: /openbmc/linux/net/mac80211/mesh.h (revision d0b73b48)
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  */
62 enum mesh_deferred_task_flags {
63 	MESH_WORK_HOUSEKEEPING,
64 	MESH_WORK_GROW_MPATH_TABLE,
65 	MESH_WORK_GROW_MPP_TABLE,
66 	MESH_WORK_ROOT,
67 	MESH_WORK_DRIFT_ADJUST,
68 };
69 
70 /**
71  * struct mesh_path - mac80211 mesh path structure
72  *
73  * @dst: mesh path destination mac address
74  * @sdata: mesh subif
75  * @next_hop: mesh neighbor to which frames for this destination will be
76  * 	forwarded
77  * @timer: mesh path discovery timer
78  * @frame_queue: pending queue for frames sent to this destination while the
79  * 	path is unresolved
80  * @sn: target sequence number
81  * @metric: current metric to this destination
82  * @hop_count: hops to destination
83  * @exp_time: in jiffies, when the path will expire or when it expired
84  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
85  * 	retry
86  * @discovery_retries: number of discovery retries
87  * @flags: mesh path flags, as specified on &enum mesh_path_flags
88  * @state_lock: mesh path state lock used to protect changes to the
89  * mpath itself.  No need to take this lock when adding or removing
90  * an mpath to a hash bucket on a path table.
91  * @rann_snd_addr: the RANN sender address
92  * @rann_metric: the aggregated path metric towards the root node
93  * @last_preq_to_root: Timestamp of last PREQ sent to root
94  * @is_root: the destination station of this path is a root node
95  * @is_gate: the destination station of this path is a mesh gate
96  *
97  *
98  * The combination of dst and sdata is unique in the mesh path table. Since the
99  * next_hop STA is only protected by RCU as well, deleting the STA must also
100  * remove/substitute the mesh_path structure and wait until that is no longer
101  * reachable before destroying the STA completely.
102  */
103 struct mesh_path {
104 	u8 dst[ETH_ALEN];
105 	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */
106 	struct ieee80211_sub_if_data *sdata;
107 	struct sta_info __rcu *next_hop;
108 	struct timer_list timer;
109 	struct sk_buff_head frame_queue;
110 	struct rcu_head rcu;
111 	u32 sn;
112 	u32 metric;
113 	u8 hop_count;
114 	unsigned long exp_time;
115 	u32 discovery_timeout;
116 	u8 discovery_retries;
117 	enum mesh_path_flags flags;
118 	spinlock_t state_lock;
119 	u8 rann_snd_addr[ETH_ALEN];
120 	u32 rann_metric;
121 	unsigned long last_preq_to_root;
122 	bool is_root;
123 	bool is_gate;
124 };
125 
126 /**
127  * struct mesh_table
128  *
129  * @hash_buckets: array of hash buckets of the table
130  * @hashwlock: array of locks to protect write operations, one per bucket
131  * @hash_mask: 2^size_order - 1, used to compute hash idx
132  * @hash_rnd: random value used for hash computations
133  * @entries: number of entries in the table
134  * @free_node: function to free nodes of the table
135  * @copy_node: function to copy nodes of the table
136  * @size_order: determines size of the table, there will be 2^size_order hash
137  *	buckets
138  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
139  *	reached, the table will grow
140  * @known_gates: list of known mesh gates and their mpaths by the station. The
141  * gate's mpath may or may not be resolved and active.
142  *
143  * rcu_head: RCU head to free the table
144  */
145 struct mesh_table {
146 	/* Number of buckets will be 2^N */
147 	struct hlist_head *hash_buckets;
148 	spinlock_t *hashwlock;		/* One per bucket, for add/del */
149 	unsigned int hash_mask;		/* (2^size_order) - 1 */
150 	__u32 hash_rnd;			/* Used for hash generation */
151 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
152 	void (*free_node) (struct hlist_node *p, bool free_leafs);
153 	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
154 	int size_order;
155 	int mean_chain_len;
156 	struct hlist_head *known_gates;
157 	spinlock_t gates_lock;
158 
159 	struct rcu_head rcu_head;
160 };
161 
162 /* Recent multicast cache */
163 /* RMC_BUCKETS must be a power of 2, maximum 256 */
164 #define RMC_BUCKETS		256
165 #define RMC_QUEUE_MAX_LEN	4
166 #define RMC_TIMEOUT		(3 * HZ)
167 
168 /**
169  * struct rmc_entry - entry in the Recent Multicast Cache
170  *
171  * @seqnum: mesh sequence number of the frame
172  * @exp_time: expiration time of the entry, in jiffies
173  * @sa: source address of the frame
174  *
175  * The Recent Multicast Cache keeps track of the latest multicast frames that
176  * have been received by a mesh interface and discards received multicast frames
177  * that are found in the cache.
178  */
179 struct rmc_entry {
180 	struct list_head list;
181 	u32 seqnum;
182 	unsigned long exp_time;
183 	u8 sa[ETH_ALEN];
184 };
185 
186 struct mesh_rmc {
187 	struct list_head bucket[RMC_BUCKETS];
188 	u32 idx_mask;
189 };
190 
191 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
192 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
193 
194 #define MESH_DEFAULT_BEACON_INTERVAL		1000 	/* in 1024 us units */
195 
196 #define MESH_PATH_EXPIRE (600 * HZ)
197 
198 /* Default maximum number of plinks per interface */
199 #define MESH_MAX_PLINKS		256
200 
201 /* Maximum number of paths per interface */
202 #define MESH_MAX_MPATHS		1024
203 
204 /* Number of frames buffered per destination for unresolved destinations */
205 #define MESH_FRAME_QUEUE_LEN	10
206 
207 /* Public interfaces */
208 /* Various */
209 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
210 				  const u8 *da, const u8 *sa);
211 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
212 		struct ieee80211_sub_if_data *sdata, char *addr4or5,
213 		char *addr6);
214 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
215 		struct ieee80211_sub_if_data *sdata);
216 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
217 			struct ieee802_11_elems *ie);
218 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
219 void mesh_mgmt_ies_add(struct sk_buff *skb,
220 		struct ieee80211_sub_if_data *sdata);
221 int mesh_add_meshconf_ie(struct sk_buff *skb,
222 			 struct ieee80211_sub_if_data *sdata);
223 int mesh_add_meshid_ie(struct sk_buff *skb,
224 		       struct ieee80211_sub_if_data *sdata);
225 int mesh_add_rsn_ie(struct sk_buff *skb,
226 		    struct ieee80211_sub_if_data *sdata);
227 int mesh_add_vendor_ies(struct sk_buff *skb,
228 			struct ieee80211_sub_if_data *sdata);
229 int mesh_add_ds_params_ie(struct sk_buff *skb,
230 			  struct ieee80211_sub_if_data *sdata);
231 int mesh_add_ht_cap_ie(struct sk_buff *skb,
232 		       struct ieee80211_sub_if_data *sdata);
233 int mesh_add_ht_oper_ie(struct sk_buff *skb,
234 			struct ieee80211_sub_if_data *sdata);
235 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
236 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
237 void ieee80211s_init(void);
238 void ieee80211s_update_metric(struct ieee80211_local *local,
239 		struct sta_info *sta, struct sk_buff *skb);
240 void ieee80211s_stop(void);
241 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
242 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
243 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
244 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
245 const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
246 
247 /* Mesh paths */
248 int mesh_nexthop_lookup(struct sk_buff *skb,
249 		struct ieee80211_sub_if_data *sdata);
250 int mesh_nexthop_resolve(struct sk_buff *skb,
251 			 struct ieee80211_sub_if_data *sdata);
252 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
253 struct mesh_path *mesh_path_lookup(u8 *dst,
254 		struct ieee80211_sub_if_data *sdata);
255 struct mesh_path *mpp_path_lookup(u8 *dst,
256 				  struct ieee80211_sub_if_data *sdata);
257 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
258 struct mesh_path *mesh_path_lookup_by_idx(int idx,
259 		struct ieee80211_sub_if_data *sdata);
260 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
261 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
262 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
263 		struct ieee80211_mgmt *mgmt, size_t len);
264 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
265 
266 int mesh_path_add_gate(struct mesh_path *mpath);
267 int mesh_path_send_to_gates(struct mesh_path *mpath);
268 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
269 /* Mesh plinks */
270 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
271 			   u8 *hw_addr,
272 			   struct ieee802_11_elems *ie);
273 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
274 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
275 void mesh_plink_broken(struct sta_info *sta);
276 void mesh_plink_deactivate(struct sta_info *sta);
277 int mesh_plink_open(struct sta_info *sta);
278 void mesh_plink_block(struct sta_info *sta);
279 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
280 			 struct ieee80211_mgmt *mgmt, size_t len,
281 			 struct ieee80211_rx_status *rx_status);
282 
283 /* Private interfaces */
284 /* Mesh tables */
285 void mesh_mpath_table_grow(void);
286 void mesh_mpp_table_grow(void);
287 /* Mesh paths */
288 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
289 		       const u8 *ra, struct ieee80211_sub_if_data *sdata);
290 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
291 void mesh_path_flush_pending(struct mesh_path *mpath);
292 void mesh_path_tx_pending(struct mesh_path *mpath);
293 int mesh_pathtbl_init(void);
294 void mesh_pathtbl_unregister(void);
295 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
296 void mesh_path_timer(unsigned long data);
297 void mesh_path_flush_by_nexthop(struct sta_info *sta);
298 void mesh_path_discard_frame(struct sk_buff *skb,
299 		struct ieee80211_sub_if_data *sdata);
300 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
301 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
302 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
303 
304 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
305 extern int mesh_paths_generation;
306 
307 #ifdef CONFIG_MAC80211_MESH
308 extern int mesh_allocated;
309 
310 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
311 {
312 	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
313 	       atomic_read(&sdata->u.mesh.estab_plinks);
314 }
315 
316 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
317 {
318 	return (min_t(long, mesh_plink_free_count(sdata),
319 		   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
320 }
321 
322 static inline void mesh_path_activate(struct mesh_path *mpath)
323 {
324 	mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
325 }
326 
327 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
328 {
329 	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
330 }
331 
332 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
333 
334 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
335 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
336 void mesh_plink_quiesce(struct sta_info *sta);
337 void mesh_plink_restart(struct sta_info *sta);
338 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
339 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
340 #else
341 #define mesh_allocated	0
342 static inline void
343 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
344 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
345 {}
346 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
347 {}
348 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
349 static inline void mesh_plink_restart(struct sta_info *sta) {}
350 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
351 { return false; }
352 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
353 {}
354 #endif
355 
356 #endif /* IEEE80211S_H */
357