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_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 195
 196 #define MESH_PATH_EXPIRE (600 * HZ)
 197
 198 /* Default maximum number of plinks per interface */
 199 #define MESH_MAX_PLINKS         256
 200
 201 /* Maximum number of paths per interface */
 202 #define MESH_MAX_MPATHS         1024
 203
 204 /* Number of frames buffered per destination for unresolved destinations */
 205 #define MESH_FRAME_QUEUE_LEN    10
 206
 207 /* Public interfaces */
 208 /* Various */
 209 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 210                                   const u8 *da, const u8 *sa);
 211 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 212                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 213                 char *addr6);
 214 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 215                 struct ieee80211_sub_if_data *sdata);
 216 bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
 217                         struct ieee802_11_elems *ie);
 218 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 219 void mesh_mgmt_ies_add(struct sk_buff *skb,
 220                 struct ieee80211_sub_if_data *sdata);
 221 int mesh_add_meshconf_ie(struct sk_buff *skb,
 222                          struct ieee80211_sub_if_data *sdata);
 223 int mesh_add_meshid_ie(struct sk_buff *skb,
 224                        struct ieee80211_sub_if_data *sdata);
 225 int mesh_add_rsn_ie(struct sk_buff *skb,
 226                     struct ieee80211_sub_if_data *sdata);
 227 int mesh_add_vendor_ies(struct sk_buff *skb,
 228                         struct ieee80211_sub_if_data *sdata);
 229 int mesh_add_ds_params_ie(struct sk_buff *skb,
 230                           struct ieee80211_sub_if_data *sdata);
 231 int mesh_add_ht_cap_ie(struct sk_buff *skb,
 232                        struct ieee80211_sub_if_data *sdata);
 233 int mesh_add_ht_oper_ie(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 *sta, struct sk_buff *skb);
 240 void ieee80211s_stop(void);
 241 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 242 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 243 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 244 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 245 const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
 246
 247 /* Mesh paths */
 248 int mesh_nexthop_lookup(struct sk_buff *skb,
 249                 struct ieee80211_sub_if_data *sdata);
 250 int mesh_nexthop_resolve(struct sk_buff *skb,
 251                          struct ieee80211_sub_if_data *sdata);
 252 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 253 struct mesh_path *mesh_path_lookup(u8 *dst,
 254                 struct ieee80211_sub_if_data *sdata);
 255 struct mesh_path *mpp_path_lookup(u8 *dst,
 256                                   struct ieee80211_sub_if_data *sdata);
 257 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 258 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 259                 struct ieee80211_sub_if_data *sdata);
 260 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 261 void mesh_path_expire(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
 266 int mesh_path_add_gate(struct mesh_path *mpath);
 267 int mesh_path_send_to_gates(struct mesh_path *mpath);
 268 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 269 /* Mesh plinks */
 270 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 271                            u8 *hw_addr,
 272                            struct ieee802_11_elems *ie);
 273 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 274 u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 275 void mesh_plink_broken(struct sta_info *sta);
 276 void mesh_plink_deactivate(struct sta_info *sta);
 277 int mesh_plink_open(struct sta_info *sta);
 278 void mesh_plink_block(struct sta_info *sta);
 279 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 280                          struct ieee80211_mgmt *mgmt, size_t len,
 281                          struct ieee80211_rx_status *rx_status);
 282
 283 /* Private interfaces */
 284 /* Mesh tables */
 285 void mesh_mpath_table_grow(void);
 286 void mesh_mpp_table_grow(void);
 287 /* Mesh paths */
 288 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 289                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 290 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 291 void mesh_path_flush_pending(struct mesh_path *mpath);
 292 void mesh_path_tx_pending(struct mesh_path *mpath);
 293 int mesh_pathtbl_init(void);
 294 void mesh_pathtbl_unregister(void);
 295 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 296 void mesh_path_timer(unsigned long data);
 297 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 298 void mesh_path_discard_frame(struct sk_buff *skb,
 299                 struct ieee80211_sub_if_data *sdata);
 300 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 301 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 302 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 303
 304 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 305 extern int mesh_paths_generation;
 306
 307 #ifdef CONFIG_MAC80211_MESH
 308 extern int mesh_allocated;
 309
 310 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 311 {
 312         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 313                atomic_read(&sdata->u.mesh.estab_plinks);
 314 }
 315
 316 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 317 {
 318         return (min_t(long, mesh_plink_free_count(sdata),
 319                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 320 }
 321
 322 static inline void mesh_path_activate(struct mesh_path *mpath)
 323 {
 324         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 325 }
 326
 327 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 328 {
 329         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 330 }
 331
 332 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 333
 334 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 335 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 336 void mesh_plink_quiesce(struct sta_info *sta);
 337 void mesh_plink_restart(struct sta_info *sta);
 338 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 339 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
 340 #else
 341 #define mesh_allocated  0
 342 static inline void
 343 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 344 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 345 {}
 346 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 347 {}
 348 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 349 static inline void mesh_plink_restart(struct sta_info *sta) {}
 350 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 351 { return false; }
 352 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 353 {}
 354 #endif
 355
 356 #endif /* IEEE80211S_H */