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 "ieee80211_i.h"
  17
  18
  19 /* Data structures */
  20
  21 /**
  22  * enum mesh_path_flags - mac80211 mesh path flags
  23  *
  24  *
  25  *
  26  * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
  27  * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
  28  * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
  29  *      number
  30  * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
  31  *      modified
  32  * @MESH_PATH_RESOLVED: the mesh path can has been resolved
  33  * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination
  34  *      already queued up, waiting for the discovery process to start.
  35  *
  36  * MESH_PATH_RESOLVED is used by the mesh path timer to
  37  * decide when to stop or cancel the mesh path discovery.
  38  */
  39 enum mesh_path_flags {
  40         MESH_PATH_ACTIVE =      BIT(0),
  41         MESH_PATH_RESOLVING =   BIT(1),
  42         MESH_PATH_SN_VALID =    BIT(2),
  43         MESH_PATH_FIXED =       BIT(3),
  44         MESH_PATH_RESOLVED =    BIT(4),
  45         MESH_PATH_REQ_QUEUED =  BIT(5),
  46 };
  47
  48 /**
  49  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
  50  *
  51  *
  52  *
  53  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
  54  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
  55  * to grow.
  56  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
  57  * grow
  58  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
  59  * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
  60  * mesh nodes
  61  */
  62 enum mesh_deferred_task_flags {
  63         MESH_WORK_HOUSEKEEPING,
  64         MESH_WORK_GROW_MPATH_TABLE,
  65         MESH_WORK_GROW_MPP_TABLE,
  66         MESH_WORK_ROOT,
  67         MESH_WORK_DRIFT_ADJUST,
  68 };
  69
  70 /**
  71  * struct mesh_path - mac80211 mesh path structure
  72  *
  73  * @dst: mesh path destination mac address
  74  * @sdata: mesh subif
  75  * @next_hop: mesh neighbor to which frames for this destination will be
  76  *      forwarded
  77  * @timer: mesh path discovery timer
  78  * @frame_queue: pending queue for frames sent to this destination while the
  79  *      path is unresolved
  80  * @sn: target sequence number
  81  * @metric: current metric to this destination
  82  * @hop_count: hops to destination
  83  * @exp_time: in jiffies, when the path will expire or when it expired
  84  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  85  *      retry
  86  * @discovery_retries: number of discovery retries
  87  * @flags: mesh path flags, as specified on &enum mesh_path_flags
  88  * @state_lock: mesh path state lock used to protect changes to the
  89  * mpath itself.  No need to take this lock when adding or removing
  90  * an mpath to a hash bucket on a path table.
  91  * @rann_snd_addr: the RANN sender address
  92  * @rann_metric: the aggregated path metric towards the root node
  93  * @last_preq_to_root: Timestamp of last PREQ sent to root
  94  * @is_root: the destination station of this path is a root node
  95  * @is_gate: the destination station of this path is a mesh gate
  96  *
  97  *
  98  * The combination of dst and sdata is unique in the mesh path table. Since the
  99  * next_hop STA is only protected by RCU as well, deleting the STA must also
 100  * remove/substitute the mesh_path structure and wait until that is no longer
 101  * reachable before destroying the STA completely.
 102  */
 103 struct mesh_path {
 104         u8 dst[ETH_ALEN];
 105         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
 106         struct ieee80211_sub_if_data *sdata;
 107         struct sta_info __rcu *next_hop;
 108         struct timer_list timer;
 109         struct sk_buff_head frame_queue;
 110         struct rcu_head rcu;
 111         u32 sn;
 112         u32 metric;
 113         u8 hop_count;
 114         unsigned long exp_time;
 115         u32 discovery_timeout;
 116         u8 discovery_retries;
 117         enum mesh_path_flags flags;
 118         spinlock_t state_lock;
 119         u8 rann_snd_addr[ETH_ALEN];
 120         u32 rann_metric;
 121         unsigned long last_preq_to_root;
 122         bool is_root;
 123         bool is_gate;
 124 };
 125
 126 /**
 127  * struct mesh_table
 128  *
 129  * @hash_buckets: array of hash buckets of the table
 130  * @hashwlock: array of locks to protect write operations, one per bucket
 131  * @hash_mask: 2^size_order - 1, used to compute hash idx
 132  * @hash_rnd: random value used for hash computations
 133  * @entries: number of entries in the table
 134  * @free_node: function to free nodes of the table
 135  * @copy_node: function to copy nodes of the table
 136  * @size_order: determines size of the table, there will be 2^size_order hash
 137  *      buckets
 138  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 139  *      reached, the table will grow
 140  * @known_gates: list of known mesh gates and their mpaths by the station. The
 141  * gate's mpath may or may not be resolved and active.
 142  *
 143  * rcu_head: RCU head to free the table
 144  */
 145 struct mesh_table {
 146         /* Number of buckets will be 2^N */
 147         struct hlist_head *hash_buckets;
 148         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 149         unsigned int hash_mask;         /* (2^size_order) - 1 */
 150         __u32 hash_rnd;                 /* Used for hash generation */
 151         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 152         void (*free_node) (struct hlist_node *p, bool free_leafs);
 153         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 154         int size_order;
 155         int mean_chain_len;
 156         struct hlist_head *known_gates;
 157         spinlock_t gates_lock;
 158
 159         struct rcu_head rcu_head;
 160 };
 161
 162 /* Recent multicast cache */
 163 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 164 #define RMC_BUCKETS             256
 165 #define RMC_QUEUE_MAX_LEN       4
 166 #define RMC_TIMEOUT             (3 * HZ)
 167
 168 /**
 169  * struct rmc_entry - entry in the Recent Multicast Cache
 170  *
 171  * @seqnum: mesh sequence number of the frame
 172  * @exp_time: expiration time of the entry, in jiffies
 173  * @sa: source address of the frame
 174  *
 175  * The Recent Multicast Cache keeps track of the latest multicast frames that
 176  * have been received by a mesh interface and discards received multicast frames
 177  * that are found in the cache.
 178  */
 179 struct rmc_entry {
 180         struct list_head list;
 181         u32 seqnum;
 182         unsigned long exp_time;
 183         u8 sa[ETH_ALEN];
 184 };
 185
 186 struct mesh_rmc {
 187         struct list_head bucket[RMC_BUCKETS];
 188         u32 idx_mask;
 189 };
 190
 191 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 192 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 193
 194 #define MESH_PATH_EXPIRE (600 * HZ)
 195
 196 /* Default maximum number of plinks per interface */
 197 #define MESH_MAX_PLINKS         256
 198
 199 /* Maximum number of paths per interface */
 200 #define MESH_MAX_MPATHS         1024
 201
 202 /* Number of frames buffered per destination for unresolved destinations */
 203 #define MESH_FRAME_QUEUE_LEN    10
 204
 205 /* Public interfaces */
 206 /* Various */
 207 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 208                                   const u8 *da, const u8 *sa);
 209 int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
 210                               struct ieee80211s_hdr *meshhdr,
 211                               const char *addr4or5, const char *addr6);
 212 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
 213                    const u8 *addr, struct ieee80211s_hdr *mesh_hdr);
 214 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
 215                         struct ieee802_11_elems *ie);
 216 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 217 void mesh_mgmt_ies_add(struct ieee80211_sub_if_data *sdata,
 218                        struct sk_buff *skb);
 219 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
 220                          struct sk_buff *skb);
 221 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata,
 222                        struct sk_buff *skb);
 223 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata,
 224                     struct sk_buff *skb);
 225 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
 226                         struct sk_buff *skb);
 227 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
 228                        struct sk_buff *skb);
 229 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
 230                         struct sk_buff *skb);
 231 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 232 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 233 void ieee80211s_init(void);
 234 void ieee80211s_update_metric(struct ieee80211_local *local,
 235                               struct sta_info *sta, struct sk_buff *skb);
 236 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 237 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 238 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 239 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 240 const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
 241 /* wrapper for ieee80211_bss_info_change_notify() */
 242 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 243                                        u32 changed);
 244
 245 /* mesh power save */
 246 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata);
 247 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
 248                                    enum nl80211_mesh_power_mode pm);
 249 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
 250                                    struct sta_info *sta,
 251                                    struct ieee80211_hdr *hdr);
 252 void ieee80211_mps_sta_status_update(struct sta_info *sta);
 253 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 254                                     struct ieee80211_hdr *hdr);
 255 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 256                                     bool tx, bool acked);
 257 void ieee80211_mps_frame_release(struct sta_info *sta,
 258                                  struct ieee802_11_elems *elems);
 259
 260 /* Mesh paths */
 261 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
 262                         struct sk_buff *skb);
 263 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
 264                          struct sk_buff *skb);
 265 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 266 struct mesh_path *mesh_path_lookup(struct ieee80211_sub_if_data *sdata,
 267                                    const u8 *dst);
 268 struct mesh_path *mpp_path_lookup(struct ieee80211_sub_if_data *sdata,
 269                                   const u8 *dst);
 270 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
 271                  const u8 *dst, const u8 *mpp);
 272 struct mesh_path *
 273 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
 274 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 275 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 276 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 277                             struct ieee80211_mgmt *mgmt, size_t len);
 278 struct mesh_path *
 279 mesh_path_add(struct ieee80211_sub_if_data *sdata, const u8 *dst);
 280
 281 int mesh_path_add_gate(struct mesh_path *mpath);
 282 int mesh_path_send_to_gates(struct mesh_path *mpath);
 283 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 284
 285 /* Mesh plinks */
 286 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 287                            u8 *hw_addr, struct ieee802_11_elems *ie);
 288 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 289 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 290 void mesh_plink_broken(struct sta_info *sta);
 291 u32 mesh_plink_deactivate(struct sta_info *sta);
 292 u32 mesh_plink_open(struct sta_info *sta);
 293 u32 mesh_plink_block(struct sta_info *sta);
 294 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 295                          struct ieee80211_mgmt *mgmt, size_t len,
 296                          struct ieee80211_rx_status *rx_status);
 297 void mesh_sta_cleanup(struct sta_info *sta);
 298
 299 /* Private interfaces */
 300 /* Mesh tables */
 301 void mesh_mpath_table_grow(void);
 302 void mesh_mpp_table_grow(void);
 303 /* Mesh paths */
 304 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
 305                        u8 ttl, const u8 *target, __le32 target_sn,
 306                        __le16 target_rcode, const u8 *ra);
 307 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 308 void mesh_path_flush_pending(struct mesh_path *mpath);
 309 void mesh_path_tx_pending(struct mesh_path *mpath);
 310 int mesh_pathtbl_init(void);
 311 void mesh_pathtbl_unregister(void);
 312 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr);
 313 void mesh_path_timer(unsigned long data);
 314 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 315 void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
 316                              struct sk_buff *skb);
 317 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 318
 319 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 320 extern int mesh_paths_generation;
 321
 322 #ifdef CONFIG_MAC80211_MESH
 323 static inline
 324 u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
 325 {
 326         atomic_inc(&sdata->u.mesh.estab_plinks);
 327         return mesh_accept_plinks_update(sdata);
 328 }
 329
 330 static inline
 331 u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
 332 {
 333         atomic_dec(&sdata->u.mesh.estab_plinks);
 334         return mesh_accept_plinks_update(sdata);
 335 }
 336
 337 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 338 {
 339         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 340                atomic_read(&sdata->u.mesh.estab_plinks);
 341 }
 342
 343 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 344 {
 345         return (min_t(long, mesh_plink_free_count(sdata),
 346                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 347 }
 348
 349 static inline void mesh_path_activate(struct mesh_path *mpath)
 350 {
 351         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 352 }
 353
 354 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 355 {
 356         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 357 }
 358
 359 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 360
 361 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 362 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
 363 void ieee80211s_stop(void);
 364 #else
 365 static inline void
 366 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 367 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 368 { return false; }
 369 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 370 {}
 371 static inline void ieee80211s_stop(void) {}
 372 #endif
 373
 374 #endif /* IEEE80211S_H */