net/mac80211/mesh.h

   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: fuction 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 /*
 168  * MESH_CFG_COMP_LEN Includes:
 169  *      - Active path selection protocol ID.
 170  *      - Active path selection metric ID.
 171  *      - Congestion control mode identifier.
 172  *      - Channel precedence.
 173  * Does not include mesh capabilities, which may vary across nodes in the same
 174  * mesh
 175  */
 176 #define MESH_CFG_CMP_LEN        (IEEE80211_MESH_CONFIG_LEN - 2)
 177
 178 /* Default values, timeouts in ms */
 179 #define MESH_TTL                31
 180 #define MESH_MAX_RETR           3
 181 #define MESH_RET_T              100
 182 #define MESH_CONF_T             100
 183 #define MESH_HOLD_T             100
 184
 185 #define MESH_PATH_TIMEOUT       5000
 186 /* Minimum interval between two consecutive PREQs originated by the same
 187  * interface
 188  */
 189 #define MESH_PREQ_MIN_INT       10
 190 #define MESH_DIAM_TRAVERSAL_TIME 50
 191 /* A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds before
 192  * timing out.  This way it will remain ACTIVE and no data frames will be
 193  * unnecesarily held in the pending queue.
 194  */
 195 #define MESH_PATH_REFRESH_TIME                  1000
 196 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
 197 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 198
 199 #define MESH_MAX_PREQ_RETRIES 4
 200 #define MESH_PATH_EXPIRE (600 * HZ)
 201
 202 /* Default maximum number of established plinks per interface */
 203 #define MESH_MAX_ESTAB_PLINKS   32
 204
 205 /* Default maximum number of plinks per interface */
 206 #define MESH_MAX_PLINKS         256
 207
 208 /* Maximum number of paths per interface */
 209 #define MESH_MAX_MPATHS         1024
 210
 211 /* Pending ANA approval */
 212 #define MESH_PLINK_CATEGORY     30
 213 #define MESH_PATH_SEL_CATEGORY  32
 214 #define MESH_PATH_SEL_ACTION    0
 215
 216 /* PERR reason codes */
 217 #define PEER_RCODE_UNSPECIFIED  11
 218 #define PERR_RCODE_NO_ROUTE     12
 219 #define PERR_RCODE_DEST_UNREACH 13
 220
 221 /* Public interfaces */
 222 /* Various */
 223 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 224                                   const u8 *da, const u8 *sa);
 225 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 226                 struct ieee80211_sub_if_data *sdata, char *addr4,
 227                 char *addr5, char *addr6);
 228 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 229                 struct ieee80211_sub_if_data *sdata);
 230 bool mesh_matches_local(struct ieee802_11_elems *ie,
 231                 struct ieee80211_sub_if_data *sdata);
 232 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 233 void mesh_mgmt_ies_add(struct sk_buff *skb,
 234                 struct ieee80211_sub_if_data *sdata);
 235 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 236 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 237 void ieee80211s_init(void);
 238 void ieee80211s_update_metric(struct ieee80211_local *local,
 239                 struct sta_info *stainfo, struct sk_buff *skb);
 240 void ieee80211s_stop(void);
 241 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 242 ieee80211_rx_result
 243 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
 244 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 245 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 246 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 247
 248 /* Mesh paths */
 249 int mesh_nexthop_lookup(struct sk_buff *skb,
 250                 struct ieee80211_sub_if_data *sdata);
 251 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 252 struct mesh_path *mesh_path_lookup(u8 *dst,
 253                 struct ieee80211_sub_if_data *sdata);
 254 struct mesh_path *mpp_path_lookup(u8 *dst,
 255                                   struct ieee80211_sub_if_data *sdata);
 256 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 257 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 258                 struct ieee80211_sub_if_data *sdata);
 259 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 260 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 261 void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
 262 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 263                 struct ieee80211_mgmt *mgmt, size_t len);
 264 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 265 /* Mesh plinks */
 266 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 267                 struct ieee80211_sub_if_data *sdata, bool add);
 268 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 269 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 270 void mesh_plink_broken(struct sta_info *sta);
 271 void mesh_plink_deactivate(struct sta_info *sta);
 272 int mesh_plink_open(struct sta_info *sta);
 273 void mesh_plink_block(struct sta_info *sta);
 274 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 275                          struct ieee80211_mgmt *mgmt, size_t len,
 276                          struct ieee80211_rx_status *rx_status);
 277
 278 /* Private interfaces */
 279 /* Mesh tables */
 280 struct mesh_table *mesh_table_alloc(int size_order);
 281 void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
 282 void mesh_mpath_table_grow(void);
 283 void mesh_mpp_table_grow(void);
 284 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
 285                 struct mesh_table *tbl);
 286 /* Mesh paths */
 287 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 288                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 289 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 290 void mesh_path_flush_pending(struct mesh_path *mpath);
 291 void mesh_path_tx_pending(struct mesh_path *mpath);
 292 int mesh_pathtbl_init(void);
 293 void mesh_pathtbl_unregister(void);
 294 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 295 void mesh_path_timer(unsigned long data);
 296 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 297 void mesh_path_discard_frame(struct sk_buff *skb,
 298                 struct ieee80211_sub_if_data *sdata);
 299 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 300 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 301 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 302
 303 extern int mesh_paths_generation;
 304
 305 #ifdef CONFIG_MAC80211_MESH
 306 extern int mesh_allocated;
 307
 308 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 309 {
 310         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 311                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 312 }
 313
 314 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 315 {
 316         return (min_t(long, mesh_plink_free_count(sdata),
 317                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 318 }
 319
 320 static inline void mesh_path_activate(struct mesh_path *mpath)
 321 {
 322         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 323 }
 324
 325 #define for_each_mesh_entry(x, p, node, i) \
 326         for (i = 0; i <= x->hash_mask; i++) \
 327                 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
 328
 329 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 330
 331 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 332 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 333 void mesh_plink_quiesce(struct sta_info *sta);
 334 void mesh_plink_restart(struct sta_info *sta);
 335 #else
 336 #define mesh_allocated  0
 337 static inline void
 338 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 339 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 340 {}
 341 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 342 {}
 343 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 344 static inline void mesh_plink_restart(struct sta_info *sta) {}
 345 #endif
 346
 347 #endif /* IEEE80211S_H */