net/mac80211/mesh.h

   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 can be used for forwarding
  28  * @MESH_PATH_RESOLVING: 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 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_DSN_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  */
  57 enum mesh_deferred_task_flags {
  58         MESH_WORK_HOUSEKEEPING,
  59         MESH_WORK_GROW_MPATH_TABLE,
  60         MESH_WORK_GROW_MPP_TABLE,
  61 };
  62
  63 /**
  64  * struct mesh_path - mac80211 mesh path structure
  65  *
  66  * @dst: mesh path destination mac address
  67  * @sdata: mesh subif
  68  * @next_hop: mesh neighbor to which frames for this destination will be
  69  *      forwarded
  70  * @timer: mesh path discovery timer
  71  * @frame_queue: pending queue for frames sent to this destination while the
  72  *      path is unresolved
  73  * @dsn: destination sequence number of the destination
  74  * @metric: current metric to this destination
  75  * @hop_count: hops to destination
  76  * @exp_time: in jiffies, when the path will expire or when it expired
  77  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  78  *      retry
  79  * @discovery_retries: number of discovery retries
  80  * @flags: mesh path flags, as specified on &enum mesh_path_flags
  81  * @state_lock: mesh path state lock
  82  *
  83  *
  84  * The combination of dst and sdata is unique in the mesh path table. Since the
  85  * next_hop STA is only protected by RCU as well, deleting the STA must also
  86  * remove/substitute the mesh_path structure and wait until that is no longer
  87  * reachable before destroying the STA completely.
  88  */
  89 struct mesh_path {
  90         u8 dst[ETH_ALEN];
  91         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  92         struct ieee80211_sub_if_data *sdata;
  93         struct sta_info *next_hop;
  94         struct timer_list timer;
  95         struct sk_buff_head frame_queue;
  96         struct rcu_head rcu;
  97         u32 dsn;
  98         u32 metric;
  99         u8 hop_count;
 100         unsigned long exp_time;
 101         u32 discovery_timeout;
 102         u8 discovery_retries;
 103         enum mesh_path_flags flags;
 104         spinlock_t state_lock;
 105 };
 106
 107 /**
 108  * struct mesh_table
 109  *
 110  * @hash_buckets: array of hash buckets of the table
 111  * @hashwlock: array of locks to protect write operations, one per bucket
 112  * @hash_mask: 2^size_order - 1, used to compute hash idx
 113  * @hash_rnd: random value used for hash computations
 114  * @entries: number of entries in the table
 115  * @free_node: function to free nodes of the table
 116  * @copy_node: fuction to copy nodes of the table
 117  * @size_order: determines size of the table, there will be 2^size_order hash
 118  *      buckets
 119  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 120  *      reached, the table will grow
 121  */
 122 struct mesh_table {
 123         /* Number of buckets will be 2^N */
 124         struct hlist_head *hash_buckets;
 125         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 126         unsigned int hash_mask;         /* (2^size_order) - 1 */
 127         __u32 hash_rnd;                 /* Used for hash generation */
 128         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 129         void (*free_node) (struct hlist_node *p, bool free_leafs);
 130         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 131         int size_order;
 132         int mean_chain_len;
 133 };
 134
 135 /* Recent multicast cache */
 136 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 137 #define RMC_BUCKETS             256
 138 #define RMC_QUEUE_MAX_LEN       4
 139 #define RMC_TIMEOUT             (3 * HZ)
 140
 141 /**
 142  * struct rmc_entry - entry in the Recent Multicast Cache
 143  *
 144  * @seqnum: mesh sequence number of the frame
 145  * @exp_time: expiration time of the entry, in jiffies
 146  * @sa: source address of the frame
 147  *
 148  * The Recent Multicast Cache keeps track of the latest multicast frames that
 149  * have been received by a mesh interface and discards received multicast frames
 150  * that are found in the cache.
 151  */
 152 struct rmc_entry {
 153         struct list_head list;
 154         u32 seqnum;
 155         unsigned long exp_time;
 156         u8 sa[ETH_ALEN];
 157 };
 158
 159 struct mesh_rmc {
 160         struct rmc_entry bucket[RMC_BUCKETS];
 161         u32 idx_mask;
 162 };
 163
 164
 165 /*
 166  * MESH_CFG_COMP_LEN Includes:
 167  *      - Active path selection protocol ID.
 168  *      - Active path selection metric ID.
 169  *      - Congestion control mode identifier.
 170  *      - Channel precedence.
 171  * Does not include mesh capabilities, which may vary across nodes in the same
 172  * mesh
 173  */
 174 #define MESH_CFG_CMP_LEN        (IEEE80211_MESH_CONFIG_LEN - 2)
 175
 176 /* Default values, timeouts in ms */
 177 #define MESH_TTL                5
 178 #define MESH_MAX_RETR           3
 179 #define MESH_RET_T              100
 180 #define MESH_CONF_T             100
 181 #define MESH_HOLD_T             100
 182
 183 #define MESH_PATH_TIMEOUT       5000
 184 /* Minimum interval between two consecutive PREQs originated by the same
 185  * interface
 186  */
 187 #define MESH_PREQ_MIN_INT       10
 188 #define MESH_DIAM_TRAVERSAL_TIME 50
 189 /* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their
 190  * expiration
 191  */
 192 #define MESH_PATH_REFRESH_TIME                  1000
 193 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
 194 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 195
 196 #define MESH_MAX_PREQ_RETRIES 4
 197 #define MESH_PATH_EXPIRE (600 * HZ)
 198
 199 /* Default maximum number of established plinks per interface */
 200 #define MESH_MAX_ESTAB_PLINKS   32
 201
 202 /* Default maximum number of plinks per interface */
 203 #define MESH_MAX_PLINKS         256
 204
 205 /* Maximum number of paths per interface */
 206 #define MESH_MAX_MPATHS         1024
 207
 208 /* Pending ANA approval */
 209 #define PLINK_CATEGORY          30
 210 #define MESH_PATH_SEL_CATEGORY  32
 211
 212 /* Public interfaces */
 213 /* Various */
 214 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 215                 char *da, char *sa);
 216 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 217                 struct ieee80211_sub_if_data *sdata, char *addr4,
 218                 char *addr5, char *addr6);
 219 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 220                 struct ieee80211_sub_if_data *sdata);
 221 bool mesh_matches_local(struct ieee802_11_elems *ie,
 222                 struct ieee80211_sub_if_data *sdata);
 223 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 224 void mesh_mgmt_ies_add(struct sk_buff *skb,
 225                 struct ieee80211_sub_if_data *sdata);
 226 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 227 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 228 void ieee80211s_init(void);
 229 void ieee80211s_update_metric(struct ieee80211_local *local,
 230                 struct sta_info *stainfo, struct sk_buff *skb);
 231 void ieee80211s_stop(void);
 232 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 233 ieee80211_rx_result
 234 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
 235 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 236 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 237
 238 /* Mesh paths */
 239 int mesh_nexthop_lookup(struct sk_buff *skb,
 240                 struct ieee80211_sub_if_data *sdata);
 241 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 242 struct mesh_path *mesh_path_lookup(u8 *dst,
 243                 struct ieee80211_sub_if_data *sdata);
 244 struct mesh_path *mpp_path_lookup(u8 *dst,
 245                                   struct ieee80211_sub_if_data *sdata);
 246 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 247 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 248                 struct ieee80211_sub_if_data *sdata);
 249 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 250 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 251 void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
 252 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 253                 struct ieee80211_mgmt *mgmt, size_t len);
 254 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 255 /* Mesh plinks */
 256 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 257                 struct ieee80211_sub_if_data *sdata, bool add);
 258 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 259 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 260 void mesh_plink_broken(struct sta_info *sta);
 261 void mesh_plink_deactivate(struct sta_info *sta);
 262 int mesh_plink_open(struct sta_info *sta);
 263 void mesh_plink_block(struct sta_info *sta);
 264 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 265                          struct ieee80211_mgmt *mgmt, size_t len,
 266                          struct ieee80211_rx_status *rx_status);
 267
 268 /* Private interfaces */
 269 /* Mesh tables */
 270 struct mesh_table *mesh_table_alloc(int size_order);
 271 void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
 272 void mesh_mpath_table_grow(void);
 273 void mesh_mpp_table_grow(void);
 274 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
 275                 struct mesh_table *tbl);
 276 /* Mesh paths */
 277 int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
 278                 struct ieee80211_sub_if_data *sdata);
 279 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 280 void mesh_path_flush_pending(struct mesh_path *mpath);
 281 void mesh_path_tx_pending(struct mesh_path *mpath);
 282 int mesh_pathtbl_init(void);
 283 void mesh_pathtbl_unregister(void);
 284 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 285 void mesh_path_timer(unsigned long data);
 286 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 287 void mesh_path_discard_frame(struct sk_buff *skb,
 288                 struct ieee80211_sub_if_data *sdata);
 289 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 290 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 291
 292 extern int mesh_paths_generation;
 293
 294 #ifdef CONFIG_MAC80211_MESH
 295 extern int mesh_allocated;
 296
 297 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 298 {
 299         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 300                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 301 }
 302
 303 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 304 {
 305         return (min_t(long, mesh_plink_free_count(sdata),
 306                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 307 }
 308
 309 static inline void mesh_path_activate(struct mesh_path *mpath)
 310 {
 311         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 312 }
 313
 314 #define for_each_mesh_entry(x, p, node, i) \
 315         for (i = 0; i <= x->hash_mask; i++) \
 316                 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
 317
 318 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 319
 320 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 321 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 322 void mesh_plink_quiesce(struct sta_info *sta);
 323 void mesh_plink_restart(struct sta_info *sta);
 324 #else
 325 #define mesh_allocated  0
 326 static inline void
 327 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 328 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 329 {}
 330 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 331 {}
 332 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 333 static inline void mesh_plink_restart(struct sta_info *sta) {}
 334 #endif
 335
 336 #endif /* IEEE80211S_H */