mac80211: Fix one more call to synchronize_rcu in atomic context.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / mac80211 / mesh.h
CommitLineData
ccf80ddf
LCC
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
902acc78 14#include <linux/types.h>
ccf80ddf 15#include <linux/jhash.h>
f375d558 16#include <asm/unaligned.h>
902acc78 17#include "ieee80211_i.h"
ccf80ddf 18
ccf80ddf
LCC
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
ccf80ddf
LCC
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 */
38enum 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),
ccf80ddf
LCC
44};
45
46/**
47 * struct mesh_path - mac80211 mesh path structure
48 *
49 * @dst: mesh path destination mac address
50 * @dev: mesh path device
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 *
d0709a65
JB
67 * The combination of dst and dev 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.
ccf80ddf
LCC
71 */
72struct mesh_path {
73 u8 dst[ETH_ALEN];
74 struct net_device *dev;
75 struct sta_info *next_hop;
76 struct timer_list timer;
77 struct sk_buff_head frame_queue;
78 struct rcu_head rcu;
79 u32 dsn;
80 u32 metric;
81 u8 hop_count;
82 unsigned long exp_time;
83 u32 discovery_timeout;
84 u8 discovery_retries;
85 enum mesh_path_flags flags;
86 spinlock_t state_lock;
87};
88
89/**
90 * struct mesh_table
91 *
92 * @hash_buckets: array of hash buckets of the table
93 * @hashwlock: array of locks to protect write operations, one per bucket
94 * @hash_mask: 2^size_order - 1, used to compute hash idx
95 * @hash_rnd: random value used for hash computations
96 * @entries: number of entries in the table
97 * @free_node: function to free nodes of the table
98 * @copy_node: fuction to copy nodes of the table
99 * @size_order: determines size of the table, there will be 2^size_order hash
100 * buckets
101 * @mean_chain_len: maximum average length for the hash buckets' list, if it is
102 * reached, the table will grow
103 */
104struct mesh_table {
105 /* Number of buckets will be 2^N */
106 struct hlist_head *hash_buckets;
107 spinlock_t *hashwlock; /* One per bucket, for add/del */
108 unsigned int hash_mask; /* (2^size_order) - 1 */
109 __u32 hash_rnd; /* Used for hash generation */
110 atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */
111 void (*free_node) (struct hlist_node *p, bool free_leafs);
112 void (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
113 int size_order;
114 int mean_chain_len;
115};
116
117/* Recent multicast cache */
118/* RMC_BUCKETS must be a power of 2, maximum 256 */
119#define RMC_BUCKETS 256
120#define RMC_QUEUE_MAX_LEN 4
121#define RMC_TIMEOUT (3 * HZ)
122
123/**
124 * struct rmc_entry - entry in the Recent Multicast Cache
125 *
126 * @seqnum: mesh sequence number of the frame
127 * @exp_time: expiration time of the entry, in jiffies
128 * @sa: source address of the frame
129 *
130 * The Recent Multicast Cache keeps track of the latest multicast frames that
131 * have been received by a mesh interface and discards received multicast frames
132 * that are found in the cache.
133 */
134struct rmc_entry {
135 struct list_head list;
136 u32 seqnum;
137 unsigned long exp_time;
138 u8 sa[ETH_ALEN];
139};
140
141struct mesh_rmc {
142 struct rmc_entry bucket[RMC_BUCKETS];
51ceddad 143 u32 idx_mask;
ccf80ddf
LCC
144};
145
146
147/* Mesh IEs constants */
148#define MESH_CFG_LEN 19
149
150/*
151 * MESH_CFG_COMP_LEN Includes:
152 * - Active path selection protocol ID.
153 * - Active path selection metric ID.
154 * - Congestion control mode identifier.
155 * - Channel precedence.
156 * Does not include mesh capabilities, which may vary across nodes in the same
157 * mesh
158 */
159#define MESH_CFG_CMP_LEN 17
160
161/* Default values, timeouts in ms */
162#define MESH_TTL 5
163#define MESH_MAX_RETR 3
164#define MESH_RET_T 100
165#define MESH_CONF_T 100
166#define MESH_HOLD_T 100
167
168#define MESH_PATH_TIMEOUT 5000
169/* Minimum interval between two consecutive PREQs originated by the same
170 * interface
171 */
172#define MESH_PREQ_MIN_INT 10
173#define MESH_DIAM_TRAVERSAL_TIME 50
174/* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their
175 * expiration
176 */
177#define MESH_PATH_REFRESH_TIME 1000
178#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
179
180#define MESH_MAX_PREQ_RETRIES 4
181#define MESH_PATH_EXPIRE (600 * HZ)
182
183/* Default maximum number of established plinks per interface */
184#define MESH_MAX_ESTAB_PLINKS 32
185
186/* Default maximum number of plinks per interface */
187#define MESH_MAX_PLINKS 256
188
189/* Maximum number of paths per interface */
190#define MESH_MAX_MPATHS 1024
191
192/* Pending ANA approval */
193#define PLINK_CATEGORY 30
194#define MESH_PATH_SEL_CATEGORY 32
195
196/* Mesh Header Flags */
197#define IEEE80211S_FLAGS_AE 0x3
198
199/* Public interfaces */
200/* Various */
201u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len);
202int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
203int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
204 struct ieee80211_sub_if_data *sdata);
205int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
206 struct net_device *dev);
207bool mesh_matches_local(struct ieee802_11_elems *ie, struct net_device *dev);
208void mesh_ids_set_default(struct ieee80211_if_sta *sta);
209void mesh_mgmt_ies_add(struct sk_buff *skb, struct net_device *dev);
210void mesh_rmc_free(struct net_device *dev);
211int mesh_rmc_init(struct net_device *dev);
212void ieee80211s_init(void);
213void ieee80211s_stop(void);
902acc78
JB
214void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
215
ccf80ddf
LCC
216/* Mesh paths */
217int mesh_nexthop_lookup(u8 *next_hop, struct sk_buff *skb,
218 struct net_device *dev);
219void mesh_path_start_discovery(struct net_device *dev);
220struct mesh_path *mesh_path_lookup(u8 *dst, struct net_device *dev);
221struct mesh_path *mesh_path_lookup_by_idx(int idx, struct net_device *dev);
222void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
223void mesh_path_expire(struct net_device *dev);
224void mesh_path_flush(struct net_device *dev);
225void mesh_rx_path_sel_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt,
226 size_t len);
227int mesh_path_add(u8 *dst, struct net_device *dev);
228/* Mesh plinks */
229void mesh_neighbour_update(u8 *hw_addr, u64 rates, struct net_device *dev,
230 bool add);
231bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie,
232 struct net_device *dev);
d0709a65 233void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
ccf80ddf
LCC
234void mesh_plink_broken(struct sta_info *sta);
235void mesh_plink_deactivate(struct sta_info *sta);
236int mesh_plink_open(struct sta_info *sta);
237int mesh_plink_close(struct sta_info *sta);
238void mesh_plink_block(struct sta_info *sta);
239void mesh_rx_plink_frame(struct net_device *dev, struct ieee80211_mgmt *mgmt,
240 size_t len, struct ieee80211_rx_status *rx_status);
241
242/* Private interfaces */
243/* Mesh tables */
244struct mesh_table *mesh_table_alloc(int size_order);
245void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
246struct mesh_table *mesh_table_grow(struct mesh_table *tbl);
247u32 mesh_table_hash(u8 *addr, struct net_device *dev, struct mesh_table *tbl);
248/* Mesh paths */
249int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
250 struct net_device *dev);
251void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
252void mesh_path_flush_pending(struct mesh_path *mpath);
253void mesh_path_tx_pending(struct mesh_path *mpath);
254int mesh_pathtbl_init(void);
255void mesh_pathtbl_unregister(void);
cfa22c71 256int mesh_path_del(u8 *addr, struct net_device *dev);
ccf80ddf
LCC
257void mesh_path_timer(unsigned long data);
258void mesh_path_flush_by_nexthop(struct sta_info *sta);
259void mesh_path_discard_frame(struct sk_buff *skb, struct net_device *dev);
260
902acc78
JB
261#ifdef CONFIG_MAC80211_MESH
262extern int mesh_allocated;
263
ccf80ddf
LCC
264static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
265{
266 return sdata->u.sta.mshcfg.dot11MeshMaxPeerLinks -
267 atomic_read(&sdata->u.sta.mshstats.estab_plinks);
268}
269
270static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
271{
d0709a65 272 return (min_t(long, mesh_plink_free_count(sdata),
ccf80ddf
LCC
273 MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
274}
275
276static inline void mesh_path_activate(struct mesh_path *mpath)
277{
278 mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
279}
280
281#define for_each_mesh_entry(x, p, node, i) \
282 for (i = 0; i <= x->hash_mask; i++) \
283 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
284
902acc78
JB
285#else
286#define mesh_allocated 0
287#endif
288
ccf80ddf
LCC
289#define MESH_PREQ(skb) (skb->cb + 30)
290
291#endif /* IEEE80211S_H */