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  * @MESH_WORK_MBSS_CHANGED: rebuild beacon and notify driver of BSS changes
  62  */
  63 enum mesh_deferred_task_flags {
  64         MESH_WORK_HOUSEKEEPING,
  65         MESH_WORK_GROW_MPATH_TABLE,
  66         MESH_WORK_GROW_MPP_TABLE,
  67         MESH_WORK_ROOT,
  68         MESH_WORK_DRIFT_ADJUST,
  69         MESH_WORK_MBSS_CHANGED,
  70 };
  71
  72 /**
  73  * struct mesh_path - mac80211 mesh path structure
  74  *
  75  * @dst: mesh path destination mac address
  76  * @sdata: mesh subif
  77  * @next_hop: mesh neighbor to which frames for this destination will be
  78  *      forwarded
  79  * @timer: mesh path discovery timer
  80  * @frame_queue: pending queue for frames sent to this destination while the
  81  *      path is unresolved
  82  * @sn: target sequence number
  83  * @metric: current metric to this destination
  84  * @hop_count: hops to destination
  85  * @exp_time: in jiffies, when the path will expire or when it expired
  86  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  87  *      retry
  88  * @discovery_retries: number of discovery retries
  89  * @flags: mesh path flags, as specified on &enum mesh_path_flags
  90  * @state_lock: mesh path state lock used to protect changes to the
  91  * mpath itself.  No need to take this lock when adding or removing
  92  * an mpath to a hash bucket on a path table.
  93  * @rann_snd_addr: the RANN sender address
  94  * @rann_metric: the aggregated path metric towards the root node
  95  * @last_preq_to_root: Timestamp of last PREQ sent to root
  96  * @is_root: the destination station of this path is a root node
  97  * @is_gate: the destination station of this path is a mesh gate
  98  *
  99  *
 100  * The combination of dst and sdata is unique in the mesh path table. Since the
 101  * next_hop STA is only protected by RCU as well, deleting the STA must also
 102  * remove/substitute the mesh_path structure and wait until that is no longer
 103  * reachable before destroying the STA completely.
 104  */
 105 struct mesh_path {
 106         u8 dst[ETH_ALEN];
 107         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
 108         struct ieee80211_sub_if_data *sdata;
 109         struct sta_info __rcu *next_hop;
 110         struct timer_list timer;
 111         struct sk_buff_head frame_queue;
 112         struct rcu_head rcu;
 113         u32 sn;
 114         u32 metric;
 115         u8 hop_count;
 116         unsigned long exp_time;
 117         u32 discovery_timeout;
 118         u8 discovery_retries;
 119         enum mesh_path_flags flags;
 120         spinlock_t state_lock;
 121         u8 rann_snd_addr[ETH_ALEN];
 122         u32 rann_metric;
 123         unsigned long last_preq_to_root;
 124         bool is_root;
 125         bool is_gate;
 126 };
 127
 128 /**
 129  * struct mesh_table
 130  *
 131  * @hash_buckets: array of hash buckets of the table
 132  * @hashwlock: array of locks to protect write operations, one per bucket
 133  * @hash_mask: 2^size_order - 1, used to compute hash idx
 134  * @hash_rnd: random value used for hash computations
 135  * @entries: number of entries in the table
 136  * @free_node: function to free nodes of the table
 137  * @copy_node: function to copy nodes of the table
 138  * @size_order: determines size of the table, there will be 2^size_order hash
 139  *      buckets
 140  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 141  *      reached, the table will grow
 142  * @known_gates: list of known mesh gates and their mpaths by the station. The
 143  * gate's mpath may or may not be resolved and active.
 144  *
 145  * rcu_head: RCU head to free the table
 146  */
 147 struct mesh_table {
 148         /* Number of buckets will be 2^N */
 149         struct hlist_head *hash_buckets;
 150         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 151         unsigned int hash_mask;         /* (2^size_order) - 1 */
 152         __u32 hash_rnd;                 /* Used for hash generation */
 153         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 154         void (*free_node) (struct hlist_node *p, bool free_leafs);
 155         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 156         int size_order;
 157         int mean_chain_len;
 158         struct hlist_head *known_gates;
 159         spinlock_t gates_lock;
 160
 161         struct rcu_head rcu_head;
 162 };
 163
 164 /* Recent multicast cache */
 165 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 166 #define RMC_BUCKETS             256
 167 #define RMC_QUEUE_MAX_LEN       4
 168 #define RMC_TIMEOUT             (3 * HZ)
 169
 170 /**
 171  * struct rmc_entry - entry in the Recent Multicast Cache
 172  *
 173  * @seqnum: mesh sequence number of the frame
 174  * @exp_time: expiration time of the entry, in jiffies
 175  * @sa: source address of the frame
 176  *
 177  * The Recent Multicast Cache keeps track of the latest multicast frames that
 178  * have been received by a mesh interface and discards received multicast frames
 179  * that are found in the cache.
 180  */
 181 struct rmc_entry {
 182         struct list_head list;
 183         u32 seqnum;
 184         unsigned long exp_time;
 185         u8 sa[ETH_ALEN];
 186 };
 187
 188 struct mesh_rmc {
 189         struct list_head bucket[RMC_BUCKETS];
 190         u32 idx_mask;
 191 };
 192
 193 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 194
 195 #define MESH_PATH_EXPIRE (600 * HZ)
 196
 197 /* Default maximum number of plinks per interface */
 198 #define MESH_MAX_PLINKS         256
 199
 200 /* Maximum number of paths per interface */
 201 #define MESH_MAX_MPATHS         1024
 202
 203 /* Number of frames buffered per destination for unresolved destinations */
 204 #define MESH_FRAME_QUEUE_LEN    10
 205
 206 /* Public interfaces */
 207 /* Various */
 208 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 209                                   const u8 *da, const u8 *sa);
 210 int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
 211                               struct ieee80211s_hdr *meshhdr,
 212                               const char *addr4or5, const char *addr6);
 213 int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
 214                    const u8 *addr, struct ieee80211s_hdr *mesh_hdr);
 215 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
 216                         struct ieee802_11_elems *ie);
 217 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 218 int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
 219                          struct sk_buff *skb);
 220 int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata,
 221                        struct sk_buff *skb);
 222 int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata,
 223                     struct sk_buff *skb);
 224 int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
 225                         struct sk_buff *skb);
 226 int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
 227                        struct sk_buff *skb);
 228 int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
 229                         struct sk_buff *skb);
 230 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 231 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 232 void ieee80211s_init(void);
 233 void ieee80211s_update_metric(struct ieee80211_local *local,
 234                               struct sta_info *sta, struct sk_buff *skb);
 235 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 236 int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 237 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 238 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 239 const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
 240 /* wrapper for ieee80211_bss_info_change_notify() */
 241 void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
 242                                        u32 changed);
 243
 244 /* mesh power save */
 245 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata);
 246 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
 247                                    enum nl80211_mesh_power_mode pm);
 248 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
 249                                    struct sta_info *sta,
 250                                    struct ieee80211_hdr *hdr);
 251 void ieee80211_mps_sta_status_update(struct sta_info *sta);
 252 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
 253                                     struct ieee80211_hdr *hdr);
 254 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
 255                                     bool tx, bool acked);
 256 void ieee80211_mps_frame_release(struct sta_info *sta,
 257                                  struct ieee802_11_elems *elems);
 258
 259 /* Mesh paths */
 260 int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
 261                         struct sk_buff *skb);
 262 int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
 263                          struct sk_buff *skb);
 264 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 265 struct mesh_path *mesh_path_lookup(struct ieee80211_sub_if_data *sdata,
 266                                    const u8 *dst);
 267 struct mesh_path *mpp_path_lookup(struct ieee80211_sub_if_data *sdata,
 268                                   const u8 *dst);
 269 int mpp_path_add(struct ieee80211_sub_if_data *sdata,
 270                  const u8 *dst, const u8 *mpp);
 271 struct mesh_path *
 272 mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);
 273 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 274 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 275 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 276                             struct ieee80211_mgmt *mgmt, size_t len);
 277 struct mesh_path *
 278 mesh_path_add(struct ieee80211_sub_if_data *sdata, const u8 *dst);
 279
 280 int mesh_path_add_gate(struct mesh_path *mpath);
 281 int mesh_path_send_to_gates(struct mesh_path *mpath);
 282 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 283
 284 /* Mesh plinks */
 285 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 286                            u8 *hw_addr, struct ieee802_11_elems *ie);
 287 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 288 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 289 void mesh_plink_broken(struct sta_info *sta);
 290 u32 mesh_plink_deactivate(struct sta_info *sta);
 291 u32 mesh_plink_open(struct sta_info *sta);
 292 u32 mesh_plink_block(struct sta_info *sta);
 293 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 294                          struct ieee80211_mgmt *mgmt, size_t len,
 295                          struct ieee80211_rx_status *rx_status);
 296 void mesh_sta_cleanup(struct sta_info *sta);
 297
 298 /* Private interfaces */
 299 /* Mesh tables */
 300 void mesh_mpath_table_grow(void);
 301 void mesh_mpp_table_grow(void);
 302 /* Mesh paths */
 303 int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,
 304                        u8 ttl, const u8 *target, u32 target_sn,
 305                        u16 target_rcode, const u8 *ra);
 306 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 307 void mesh_path_flush_pending(struct mesh_path *mpath);
 308 void mesh_path_tx_pending(struct mesh_path *mpath);
 309 int mesh_pathtbl_init(void);
 310 void mesh_pathtbl_unregister(void);
 311 int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr);
 312 void mesh_path_timer(unsigned long data);
 313 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 314 void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
 315                              struct sk_buff *skb);
 316 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 317
 318 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 319 extern int mesh_paths_generation;
 320
 321 #ifdef CONFIG_MAC80211_MESH
 322 static inline
 323 u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
 324 {
 325         atomic_inc(&sdata->u.mesh.estab_plinks);
 326         return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
 327 }
 328
 329 static inline
 330 u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
 331 {
 332         atomic_dec(&sdata->u.mesh.estab_plinks);
 333         return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
 334 }
 335
 336 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 337 {
 338         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 339                atomic_read(&sdata->u.mesh.estab_plinks);
 340 }
 341
 342 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 343 {
 344         return (min_t(long, mesh_plink_free_count(sdata),
 345                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 346 }
 347
 348 static inline void mesh_path_activate(struct mesh_path *mpath)
 349 {
 350         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 351 }
 352
 353 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 354 {
 355         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 356 }
 357
 358 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 359
 360 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 361 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
 362 void ieee80211s_stop(void);
 363 #else
 364 static inline void
 365 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 366 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 367 { return false; }
 368 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 369 {}
 370 static inline void ieee80211s_stop(void) {}
 371 #endif
 372
 373 #endif /* IEEE80211S_H */