xref: /openbmc/linux/net/mac80211/mesh.h (revision d2a079fd48c05235b86016a33a79cb86a86e15a8)
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  */
60 enum mesh_deferred_task_flags {
61 	MESH_WORK_HOUSEKEEPING,
62 	MESH_WORK_GROW_MPATH_TABLE,
63 	MESH_WORK_GROW_MPP_TABLE,
64 	MESH_WORK_ROOT,
65 };
66 
67 /**
68  * struct mesh_path - mac80211 mesh path structure
69  *
70  * @dst: mesh path destination mac address
71  * @sdata: mesh subif
72  * @next_hop: mesh neighbor to which frames for this destination will be
73  * 	forwarded
74  * @timer: mesh path discovery timer
75  * @frame_queue: pending queue for frames sent to this destination while the
76  * 	path is unresolved
77  * @sn: target sequence number
78  * @metric: current metric to this destination
79  * @hop_count: hops to destination
80  * @exp_time: in jiffies, when the path will expire or when it expired
81  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
82  * 	retry
83  * @discovery_retries: number of discovery retries
84  * @flags: mesh path flags, as specified on &enum mesh_path_flags
85  * @state_lock: mesh path state lock used to protect changes to the
86  * mpath itself.  No need to take this lock when adding or removing
87  * an mpath to a hash bucket on a path table.
88  * @rann_snd_addr: the RANN sender address
89  * @rann_metric: the aggregated path metric towards the root node
90  * @is_root: the destination station of this path is a root node
91  * @is_gate: the destination station of this path is a mesh gate
92  *
93  *
94  * The combination of dst and sdata is unique in the mesh path table. Since the
95  * next_hop STA is only protected by RCU as well, deleting the STA must also
96  * remove/substitute the mesh_path structure and wait until that is no longer
97  * reachable before destroying the STA completely.
98  */
99 struct mesh_path {
100 	u8 dst[ETH_ALEN];
101 	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */
102 	struct ieee80211_sub_if_data *sdata;
103 	struct sta_info __rcu *next_hop;
104 	struct timer_list timer;
105 	struct sk_buff_head frame_queue;
106 	struct rcu_head rcu;
107 	u32 sn;
108 	u32 metric;
109 	u8 hop_count;
110 	unsigned long exp_time;
111 	u32 discovery_timeout;
112 	u8 discovery_retries;
113 	enum mesh_path_flags flags;
114 	spinlock_t state_lock;
115 	u8 rann_snd_addr[ETH_ALEN];
116 	u32 rann_metric;
117 	bool is_root;
118 	bool is_gate;
119 };
120 
121 /**
122  * struct mesh_table
123  *
124  * @hash_buckets: array of hash buckets of the table
125  * @hashwlock: array of locks to protect write operations, one per bucket
126  * @hash_mask: 2^size_order - 1, used to compute hash idx
127  * @hash_rnd: random value used for hash computations
128  * @entries: number of entries in the table
129  * @free_node: function to free nodes of the table
130  * @copy_node: function to copy nodes of the table
131  * @size_order: determines size of the table, there will be 2^size_order hash
132  *	buckets
133  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
134  *	reached, the table will grow
135  * @known_gates: list of known mesh gates and their mpaths by the station. The
136  * gate's mpath may or may not be resolved and active.
137  *
138  * rcu_head: RCU head to free the table
139  */
140 struct mesh_table {
141 	/* Number of buckets will be 2^N */
142 	struct hlist_head *hash_buckets;
143 	spinlock_t *hashwlock;		/* One per bucket, for add/del */
144 	unsigned int hash_mask;		/* (2^size_order) - 1 */
145 	__u32 hash_rnd;			/* Used for hash generation */
146 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
147 	void (*free_node) (struct hlist_node *p, bool free_leafs);
148 	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
149 	int size_order;
150 	int mean_chain_len;
151 	struct hlist_head *known_gates;
152 	spinlock_t gates_lock;
153 
154 	struct rcu_head rcu_head;
155 };
156 
157 /* Recent multicast cache */
158 /* RMC_BUCKETS must be a power of 2, maximum 256 */
159 #define RMC_BUCKETS		256
160 #define RMC_QUEUE_MAX_LEN	4
161 #define RMC_TIMEOUT		(3 * HZ)
162 
163 /**
164  * struct rmc_entry - entry in the Recent Multicast Cache
165  *
166  * @seqnum: mesh sequence number of the frame
167  * @exp_time: expiration time of the entry, in jiffies
168  * @sa: source address of the frame
169  *
170  * The Recent Multicast Cache keeps track of the latest multicast frames that
171  * have been received by a mesh interface and discards received multicast frames
172  * that are found in the cache.
173  */
174 struct rmc_entry {
175 	struct list_head list;
176 	u32 seqnum;
177 	unsigned long exp_time;
178 	u8 sa[ETH_ALEN];
179 };
180 
181 struct mesh_rmc {
182 	struct rmc_entry bucket[RMC_BUCKETS];
183 	u32 idx_mask;
184 };
185 
186 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
187 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
188 
189 #define MESH_DEFAULT_BEACON_INTERVAL		1000 	/* in 1024 us units */
190 
191 #define MESH_PATH_EXPIRE (600 * HZ)
192 
193 /* Default maximum number of plinks per interface */
194 #define MESH_MAX_PLINKS		256
195 
196 /* Maximum number of paths per interface */
197 #define MESH_MAX_MPATHS		1024
198 
199 /* Public interfaces */
200 /* Various */
201 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
202 				  const u8 *da, const u8 *sa);
203 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
204 		struct ieee80211_sub_if_data *sdata, char *addr4or5,
205 		char *addr6);
206 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
207 		struct ieee80211_sub_if_data *sdata);
208 bool mesh_matches_local(struct ieee802_11_elems *ie,
209 		struct ieee80211_sub_if_data *sdata);
210 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
211 void mesh_mgmt_ies_add(struct sk_buff *skb,
212 		struct ieee80211_sub_if_data *sdata);
213 int mesh_add_meshconf_ie(struct sk_buff *skb,
214 			 struct ieee80211_sub_if_data *sdata);
215 int mesh_add_meshid_ie(struct sk_buff *skb,
216 		       struct ieee80211_sub_if_data *sdata);
217 int mesh_add_rsn_ie(struct sk_buff *skb,
218 		    struct ieee80211_sub_if_data *sdata);
219 int mesh_add_vendor_ies(struct sk_buff *skb,
220 			struct ieee80211_sub_if_data *sdata);
221 int mesh_add_ds_params_ie(struct sk_buff *skb,
222 			  struct ieee80211_sub_if_data *sdata);
223 int mesh_add_ht_cap_ie(struct sk_buff *skb,
224 		       struct ieee80211_sub_if_data *sdata);
225 int mesh_add_ht_oper_ie(struct sk_buff *skb,
226 			struct ieee80211_sub_if_data *sdata);
227 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
228 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
229 void ieee80211s_init(void);
230 void ieee80211s_update_metric(struct ieee80211_local *local,
231 		struct sta_info *stainfo, struct sk_buff *skb);
232 void ieee80211s_stop(void);
233 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
234 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
235 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
236 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
237 
238 /* Mesh paths */
239 int mesh_nexthop_lookup(struct sk_buff *skb,
240 		struct ieee80211_sub_if_data *sdata);
241 int mesh_nexthop_resolve(struct sk_buff *skb,
242 			 struct ieee80211_sub_if_data *sdata);
243 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
244 struct mesh_path *mesh_path_lookup(u8 *dst,
245 		struct ieee80211_sub_if_data *sdata);
246 struct mesh_path *mpp_path_lookup(u8 *dst,
247 				  struct ieee80211_sub_if_data *sdata);
248 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
249 struct mesh_path *mesh_path_lookup_by_idx(int idx,
250 		struct ieee80211_sub_if_data *sdata);
251 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
252 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
253 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
254 		struct ieee80211_mgmt *mgmt, size_t len);
255 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
256 
257 int mesh_path_add_gate(struct mesh_path *mpath);
258 int mesh_path_send_to_gates(struct mesh_path *mpath);
259 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
260 /* Mesh plinks */
261 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
262 		struct ieee80211_sub_if_data *sdata,
263 		struct ieee802_11_elems *ie);
264 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
265 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
266 void mesh_plink_broken(struct sta_info *sta);
267 void mesh_plink_deactivate(struct sta_info *sta);
268 int mesh_plink_open(struct sta_info *sta);
269 void mesh_plink_block(struct sta_info *sta);
270 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
271 			 struct ieee80211_mgmt *mgmt, size_t len,
272 			 struct ieee80211_rx_status *rx_status);
273 
274 /* Private interfaces */
275 /* Mesh tables */
276 void mesh_mpath_table_grow(void);
277 void mesh_mpp_table_grow(void);
278 /* Mesh paths */
279 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
280 		       const u8 *ra, struct ieee80211_sub_if_data *sdata);
281 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
282 void mesh_path_flush_pending(struct mesh_path *mpath);
283 void mesh_path_tx_pending(struct mesh_path *mpath);
284 int mesh_pathtbl_init(void);
285 void mesh_pathtbl_unregister(void);
286 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
287 void mesh_path_timer(unsigned long data);
288 void mesh_path_flush_by_nexthop(struct sta_info *sta);
289 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
290 void mesh_path_discard_frame(struct sk_buff *skb,
291 		struct ieee80211_sub_if_data *sdata);
292 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
293 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
294 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
295 
296 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
297 extern int mesh_paths_generation;
298 
299 #ifdef CONFIG_MAC80211_MESH
300 extern int mesh_allocated;
301 
302 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
303 {
304 	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
305 	       atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
306 }
307 
308 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
309 {
310 	return (min_t(long, mesh_plink_free_count(sdata),
311 		   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
312 }
313 
314 static inline void mesh_path_activate(struct mesh_path *mpath)
315 {
316 	mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
317 }
318 
319 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
320 {
321 	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
322 }
323 
324 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
325 
326 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
327 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
328 void mesh_plink_quiesce(struct sta_info *sta);
329 void mesh_plink_restart(struct sta_info *sta);
330 #else
331 #define mesh_allocated	0
332 static inline void
333 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
334 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
335 {}
336 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
337 {}
338 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
339 static inline void mesh_plink_restart(struct sta_info *sta) {}
340 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
341 { return false; }
342 #endif
343 
344 #endif /* IEEE80211S_H */
345