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
mesh_plink_free_count(struct ieee80211_sub_if_data * sdata)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
mesh_plink_availables(struct ieee80211_sub_if_data * sdata)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
mesh_path_activate(struct mesh_path * mpath)282 static inline void mesh_path_activate(struct mesh_path *mpath)
283 {
284 mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
285 }
286
mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data * sdata)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
ieee80211_mesh_notify_scan_completed(struct ieee80211_local * local)305 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
ieee80211_mesh_quiesce(struct ieee80211_sub_if_data * sdata)306 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
307 {}
ieee80211_mesh_restart(struct ieee80211_sub_if_data * sdata)308 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
309 {}
mesh_plink_quiesce(struct sta_info * sta)310 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
mesh_plink_restart(struct sta_info * sta)311 static inline void mesh_plink_restart(struct sta_info *sta) {}
mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data * sdata)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