xref: /openbmc/linux/net/mac80211/mesh.h (revision 565d76cb)
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 <asm/unaligned.h>
17 #include "ieee80211_i.h"
18 
19 
20 /* Data structures */
21 
22 /**
23  * enum mesh_path_flags - mac80211 mesh path flags
24  *
25  *
26  *
27  * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
28  * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
29  * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
30  * 	number
31  * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
32  * 	modified
33  * @MESH_PATH_RESOLVED: the mesh path can has been resolved
34  *
35  * MESH_PATH_RESOLVED is used by the mesh path timer to
36  * decide when to stop or cancel the mesh path discovery.
37  */
38 enum mesh_path_flags {
39 	MESH_PATH_ACTIVE =	BIT(0),
40 	MESH_PATH_RESOLVING =	BIT(1),
41 	MESH_PATH_SN_VALID =	BIT(2),
42 	MESH_PATH_FIXED	=	BIT(3),
43 	MESH_PATH_RESOLVED =	BIT(4),
44 };
45 
46 /**
47  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
48  *
49  *
50  *
51  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
52  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
53  * to grow.
54  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
55  * grow
56  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
57  */
58 enum mesh_deferred_task_flags {
59 	MESH_WORK_HOUSEKEEPING,
60 	MESH_WORK_GROW_MPATH_TABLE,
61 	MESH_WORK_GROW_MPP_TABLE,
62 	MESH_WORK_ROOT,
63 };
64 
65 /**
66  * struct mesh_path - mac80211 mesh path structure
67  *
68  * @dst: mesh path destination mac address
69  * @sdata: mesh subif
70  * @next_hop: mesh neighbor to which frames for this destination will be
71  * 	forwarded
72  * @timer: mesh path discovery timer
73  * @frame_queue: pending queue for frames sent to this destination while the
74  * 	path is unresolved
75  * @sn: target sequence number
76  * @metric: current metric to this destination
77  * @hop_count: hops to destination
78  * @exp_time: in jiffies, when the path will expire or when it expired
79  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
80  * 	retry
81  * @discovery_retries: number of discovery retries
82  * @flags: mesh path flags, as specified on &enum mesh_path_flags
83  * @state_lock: mesh path state lock
84  *
85  *
86  * The combination of dst and sdata is unique in the mesh path table. Since the
87  * next_hop STA is only protected by RCU as well, deleting the STA must also
88  * remove/substitute the mesh_path structure and wait until that is no longer
89  * reachable before destroying the STA completely.
90  */
91 struct mesh_path {
92 	u8 dst[ETH_ALEN];
93 	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */
94 	struct ieee80211_sub_if_data *sdata;
95 	struct sta_info *next_hop;
96 	struct timer_list timer;
97 	struct sk_buff_head frame_queue;
98 	struct rcu_head rcu;
99 	u32 sn;
100 	u32 metric;
101 	u8 hop_count;
102 	unsigned long exp_time;
103 	u32 discovery_timeout;
104 	u8 discovery_retries;
105 	enum mesh_path_flags flags;
106 	spinlock_t state_lock;
107 };
108 
109 /**
110  * struct mesh_table
111  *
112  * @hash_buckets: array of hash buckets of the table
113  * @hashwlock: array of locks to protect write operations, one per bucket
114  * @hash_mask: 2^size_order - 1, used to compute hash idx
115  * @hash_rnd: random value used for hash computations
116  * @entries: number of entries in the table
117  * @free_node: function to free nodes of the table
118  * @copy_node: function to copy nodes of the table
119  * @size_order: determines size of the table, there will be 2^size_order hash
120  *	buckets
121  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
122  *	reached, the table will grow
123  */
124 struct mesh_table {
125 	/* Number of buckets will be 2^N */
126 	struct hlist_head *hash_buckets;
127 	spinlock_t *hashwlock;		/* One per bucket, for add/del */
128 	unsigned int hash_mask;		/* (2^size_order) - 1 */
129 	__u32 hash_rnd;			/* Used for hash generation */
130 	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */
131 	void (*free_node) (struct hlist_node *p, bool free_leafs);
132 	int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
133 	int size_order;
134 	int mean_chain_len;
135 };
136 
137 /* Recent multicast cache */
138 /* RMC_BUCKETS must be a power of 2, maximum 256 */
139 #define RMC_BUCKETS		256
140 #define RMC_QUEUE_MAX_LEN	4
141 #define RMC_TIMEOUT		(3 * HZ)
142 
143 /**
144  * struct rmc_entry - entry in the Recent Multicast Cache
145  *
146  * @seqnum: mesh sequence number of the frame
147  * @exp_time: expiration time of the entry, in jiffies
148  * @sa: source address of the frame
149  *
150  * The Recent Multicast Cache keeps track of the latest multicast frames that
151  * have been received by a mesh interface and discards received multicast frames
152  * that are found in the cache.
153  */
154 struct rmc_entry {
155 	struct list_head list;
156 	u32 seqnum;
157 	unsigned long exp_time;
158 	u8 sa[ETH_ALEN];
159 };
160 
161 struct mesh_rmc {
162 	struct rmc_entry bucket[RMC_BUCKETS];
163 	u32 idx_mask;
164 };
165 
166 
167 #define MESH_DEFAULT_BEACON_INTERVAL		1000 	/* in 1024 us units */
168 
169 #define MESH_PATH_EXPIRE (600 * HZ)
170 
171 /* Default maximum number of plinks per interface */
172 #define MESH_MAX_PLINKS		256
173 
174 /* Maximum number of paths per interface */
175 #define MESH_MAX_MPATHS		1024
176 
177 /* Pending ANA approval */
178 #define MESH_PATH_SEL_ACTION	0
179 
180 /* PERR reason codes */
181 #define PEER_RCODE_UNSPECIFIED  11
182 #define PERR_RCODE_NO_ROUTE     12
183 #define PERR_RCODE_DEST_UNREACH 13
184 
185 /* Public interfaces */
186 /* Various */
187 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
188 				  const u8 *da, const u8 *sa);
189 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
190 		struct ieee80211_sub_if_data *sdata, char *addr4or5,
191 		char *addr6);
192 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
193 		struct ieee80211_sub_if_data *sdata);
194 bool mesh_matches_local(struct ieee802_11_elems *ie,
195 		struct ieee80211_sub_if_data *sdata);
196 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
197 void mesh_mgmt_ies_add(struct sk_buff *skb,
198 		struct ieee80211_sub_if_data *sdata);
199 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
200 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
201 void ieee80211s_init(void);
202 void ieee80211s_update_metric(struct ieee80211_local *local,
203 		struct sta_info *stainfo, struct sk_buff *skb);
204 void ieee80211s_stop(void);
205 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
206 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
207 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
208 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
209 
210 /* Mesh paths */
211 int mesh_nexthop_lookup(struct sk_buff *skb,
212 		struct ieee80211_sub_if_data *sdata);
213 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
214 struct mesh_path *mesh_path_lookup(u8 *dst,
215 		struct ieee80211_sub_if_data *sdata);
216 struct mesh_path *mpp_path_lookup(u8 *dst,
217 				  struct ieee80211_sub_if_data *sdata);
218 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
219 struct mesh_path *mesh_path_lookup_by_idx(int idx,
220 		struct ieee80211_sub_if_data *sdata);
221 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
222 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
223 void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
224 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
225 		struct ieee80211_mgmt *mgmt, size_t len);
226 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
227 /* Mesh plinks */
228 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
229 		struct ieee80211_sub_if_data *sdata, bool add);
230 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
231 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
232 void mesh_plink_broken(struct sta_info *sta);
233 void mesh_plink_deactivate(struct sta_info *sta);
234 int mesh_plink_open(struct sta_info *sta);
235 void mesh_plink_block(struct sta_info *sta);
236 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
237 			 struct ieee80211_mgmt *mgmt, size_t len,
238 			 struct ieee80211_rx_status *rx_status);
239 
240 /* Private interfaces */
241 /* Mesh tables */
242 struct mesh_table *mesh_table_alloc(int size_order);
243 void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
244 void mesh_mpath_table_grow(void);
245 void mesh_mpp_table_grow(void);
246 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
247 		struct mesh_table *tbl);
248 /* Mesh paths */
249 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
250 		       const u8 *ra, struct ieee80211_sub_if_data *sdata);
251 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
252 void mesh_path_flush_pending(struct mesh_path *mpath);
253 void mesh_path_tx_pending(struct mesh_path *mpath);
254 int mesh_pathtbl_init(void);
255 void mesh_pathtbl_unregister(void);
256 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
257 void mesh_path_timer(unsigned long data);
258 void mesh_path_flush_by_nexthop(struct sta_info *sta);
259 void mesh_path_discard_frame(struct sk_buff *skb,
260 		struct ieee80211_sub_if_data *sdata);
261 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
262 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
263 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
264 
265 extern int mesh_paths_generation;
266 
267 #ifdef CONFIG_MAC80211_MESH
268 extern int mesh_allocated;
269 
270 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
271 {
272 	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
273 	       atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
274 }
275 
276 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
277 {
278 	return (min_t(long, mesh_plink_free_count(sdata),
279 		   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
280 }
281 
282 static inline void mesh_path_activate(struct mesh_path *mpath)
283 {
284 	mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
285 }
286 
287 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
288 {
289 	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
290 }
291 
292 #define for_each_mesh_entry(x, p, node, i) \
293 	for (i = 0; i <= x->hash_mask; i++) \
294 		hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
295 
296 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
297 
298 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
299 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
300 void mesh_plink_quiesce(struct sta_info *sta);
301 void mesh_plink_restart(struct sta_info *sta);
302 #else
303 #define mesh_allocated	0
304 static inline void
305 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
306 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
307 {}
308 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
309 {}
310 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
311 static inline void mesh_plink_restart(struct sta_info *sta) {}
312 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
313 { return false; }
314 #endif
315 
316 #endif /* IEEE80211S_H */
317