1 /*
2 * Copyright (c) 2008 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 is can be used for forwarding
28 * @MESH_PATH_RESOLVED: the discovery process is running for this mesh path
29 * @MESH_PATH_DSN_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 and MESH_PATH_DELETE are 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_DSN_VALID = BIT(2),
42 MESH_PATH_FIXED = BIT(3),
43 MESH_PATH_RESOLVED = BIT(4),
44 };
45
46 /**
47 * struct mesh_path - mac80211 mesh path structure
48 *
49 * @dst: mesh path destination mac address
50 * @sdata: mesh subif
51 * @next_hop: mesh neighbor to which frames for this destination will be
52 * forwarded
53 * @timer: mesh path discovery timer
54 * @frame_queue: pending queue for frames sent to this destination while the
55 * path is unresolved
56 * @dsn: destination sequence number of the destination
57 * @metric: current metric to this destination
58 * @hop_count: hops to destination
59 * @exp_time: in jiffies, when the path will expire or when it expired
60 * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
61 * retry
62 * @discovery_retries: number of discovery retries
63 * @flags: mesh path flags, as specified on &enum mesh_path_flags
64 * @state_lock: mesh pat state lock
65 *
66 *
67 * The combination of dst and sdata is unique in the mesh path table. Since the
68 * next_hop STA is only protected by RCU as well, deleting the STA must also
69 * remove/substitute the mesh_path structure and wait until that is no longer
70 * reachable before destroying the STA completely.
71 */
72 struct mesh_path {
73 u8 dst[ETH_ALEN];
74 u8 mpp[ETH_ALEN]; /* used for MPP or MAP */
75 struct ieee80211_sub_if_data *sdata;
76 struct sta_info *next_hop;
77 struct timer_list timer;
78 struct sk_buff_head frame_queue;
79 struct rcu_head rcu;
80 u32 dsn;
81 u32 metric;
82 u8 hop_count;
83 unsigned long exp_time;
84 u32 discovery_timeout;
85 u8 discovery_retries;
86 enum mesh_path_flags flags;
87 spinlock_t state_lock;
88 };
89
90 /**
91 * struct mesh_table
92 *
93 * @hash_buckets: array of hash buckets of the table
94 * @hashwlock: array of locks to protect write operations, one per bucket
95 * @hash_mask: 2^size_order - 1, used to compute hash idx
96 * @hash_rnd: random value used for hash computations
97 * @entries: number of entries in the table
98 * @free_node: function to free nodes of the table
99 * @copy_node: fuction to copy nodes of the table
100 * @size_order: determines size of the table, there will be 2^size_order hash
101 * buckets
102 * @mean_chain_len: maximum average length for the hash buckets' list, if it is
103 * reached, the table will grow
104 */
105 struct mesh_table {
106 /* Number of buckets will be 2^N */
107 struct hlist_head *hash_buckets;
108 spinlock_t *hashwlock; /* One per bucket, for add/del */
109 unsigned int hash_mask; /* (2^size_order) - 1 */
110 __u32 hash_rnd; /* Used for hash generation */
111 atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */
112 void (*free_node) (struct hlist_node *p, bool free_leafs);
113 int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
114 int size_order;
115 int mean_chain_len;
116 };
117
118 /* Recent multicast cache */
119 /* RMC_BUCKETS must be a power of 2, maximum 256 */
120 #define RMC_BUCKETS 256
121 #define RMC_QUEUE_MAX_LEN 4
122 #define RMC_TIMEOUT (3 * HZ)
123
124 /**
125 * struct rmc_entry - entry in the Recent Multicast Cache
126 *
127 * @seqnum: mesh sequence number of the frame
128 * @exp_time: expiration time of the entry, in jiffies
129 * @sa: source address of the frame
130 *
131 * The Recent Multicast Cache keeps track of the latest multicast frames that
132 * have been received by a mesh interface and discards received multicast frames
133 * that are found in the cache.
134 */
135 struct rmc_entry {
136 struct list_head list;
137 u32 seqnum;
138 unsigned long exp_time;
139 u8 sa[ETH_ALEN];
140 };
141
142 struct mesh_rmc {
143 struct rmc_entry bucket[RMC_BUCKETS];
144 u32 idx_mask;
145 };
146
147
148 /*
149 * MESH_CFG_COMP_LEN Includes:
150 * - Active path selection protocol ID.
151 * - Active path selection metric ID.
152 * - Congestion control mode identifier.
153 * - Channel precedence.
154 * Does not include mesh capabilities, which may vary across nodes in the same
155 * mesh
156 */
157 #define MESH_CFG_CMP_LEN (IEEE80211_MESH_CONFIG_LEN - 2)
158
159 /* Default values, timeouts in ms */
160 #define MESH_TTL 5
161 #define MESH_MAX_RETR 3
162 #define MESH_RET_T 100
163 #define MESH_CONF_T 100
164 #define MESH_HOLD_T 100
165
166 #define MESH_PATH_TIMEOUT 5000
167 /* Minimum interval between two consecutive PREQs originated by the same
168 * interface
169 */
170 #define MESH_PREQ_MIN_INT 10
171 #define MESH_DIAM_TRAVERSAL_TIME 50
172 /* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their
173 * expiration
174 */
175 #define MESH_PATH_REFRESH_TIME 1000
176 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
177
178 #define MESH_MAX_PREQ_RETRIES 4
179 #define MESH_PATH_EXPIRE (600 * HZ)
180
181 /* Default maximum number of established plinks per interface */
182 #define MESH_MAX_ESTAB_PLINKS 32
183
184 /* Default maximum number of plinks per interface */
185 #define MESH_MAX_PLINKS 256
186
187 /* Maximum number of paths per interface */
188 #define MESH_MAX_MPATHS 1024
189
190 /* Pending ANA approval */
191 #define PLINK_CATEGORY 30
192 #define MESH_PATH_SEL_CATEGORY 32
193
194 /* Mesh Header Flags */
195 #define IEEE80211S_FLAGS_AE 0x3
196
197 /* Public interfaces */
198 /* Various */
199 u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len);
200 int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
201 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
202 struct ieee80211_sub_if_data *sdata);
203 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
204 struct ieee80211_sub_if_data *sdata);
205 bool mesh_matches_local(struct ieee802_11_elems *ie,
206 struct ieee80211_sub_if_data *sdata);
207 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
208 void mesh_mgmt_ies_add(struct sk_buff *skb,
209 struct ieee80211_sub_if_data *sdata);
210 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
211 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
212 void ieee80211s_init(void);
213 void ieee80211s_stop(void);
214 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
215 ieee80211_rx_result
216 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
217 struct ieee80211_rx_status *rx_status);
218 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
219 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
220
221 /* Mesh paths */
222 int mesh_nexthop_lookup(struct sk_buff *skb,
223 struct ieee80211_sub_if_data *sdata);
224 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
225 struct mesh_path *mesh_path_lookup(u8 *dst,
226 struct ieee80211_sub_if_data *sdata);
227 struct mesh_path *mpp_path_lookup(u8 *dst,
228 struct ieee80211_sub_if_data *sdata);
229 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
230 struct mesh_path *mesh_path_lookup_by_idx(int idx,
231 struct ieee80211_sub_if_data *sdata);
232 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
233 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
234 void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
235 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
236 struct ieee80211_mgmt *mgmt, size_t len);
237 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
238 /* Mesh plinks */
239 void mesh_neighbour_update(u8 *hw_addr, u64 rates,
240 struct ieee80211_sub_if_data *sdata, bool add);
241 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
242 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
243 void mesh_plink_broken(struct sta_info *sta);
244 void mesh_plink_deactivate(struct sta_info *sta);
245 int mesh_plink_open(struct sta_info *sta);
246 int mesh_plink_close(struct sta_info *sta);
247 void mesh_plink_block(struct sta_info *sta);
248 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
249 struct ieee80211_mgmt *mgmt, size_t len,
250 struct ieee80211_rx_status *rx_status);
251
252 /* Private interfaces */
253 /* Mesh tables */
254 struct mesh_table *mesh_table_alloc(int size_order);
255 void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
256 struct mesh_table *mesh_table_grow(struct mesh_table *tbl);
257 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
258 struct mesh_table *tbl);
259 /* Mesh paths */
260 int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
261 struct ieee80211_sub_if_data *sdata);
262 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
263 void mesh_path_flush_pending(struct mesh_path *mpath);
264 void mesh_path_tx_pending(struct mesh_path *mpath);
265 int mesh_pathtbl_init(void);
266 void mesh_pathtbl_unregister(void);
267 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
268 void mesh_path_timer(unsigned long data);
269 void mesh_path_flush_by_nexthop(struct sta_info *sta);
270 void mesh_path_discard_frame(struct sk_buff *skb,
271 struct ieee80211_sub_if_data *sdata);
272
273 #ifdef CONFIG_MAC80211_MESH
274 extern int mesh_allocated;
275
mesh_plink_free_count(struct ieee80211_sub_if_data * sdata)276 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
277 {
278 return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
279 atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
280 }
281
mesh_plink_availables(struct ieee80211_sub_if_data * sdata)282 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
283 {
284 return (min_t(long, mesh_plink_free_count(sdata),
285 MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
286 }
287
mesh_path_activate(struct mesh_path * mpath)288 static inline void mesh_path_activate(struct mesh_path *mpath)
289 {
290 mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
291 }
292
293 #define for_each_mesh_entry(x, p, node, i) \
294 for (i = 0; i <= x->hash_mask; i++) \
295 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
296
297 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
298
299 #else
300 #define mesh_allocated 0
301 static inline void
ieee80211_mesh_notify_scan_completed(struct ieee80211_local * local)302 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
303 #endif
304
305 #endif /* IEEE80211S_H */
306