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_config_capab_flags - mesh config IE capability flags
  23  *
  24  * @MESHCONF_CAPAB_ACCEPT_PLINKS: STA is willing to establish
  25  * additional mesh peerings with other mesh STAs
  26  * @MESHCONF_CAPAB_FORWARDING: the STA forwards MSDUs
  27  * @MESHCONF_CAPAB_TBTT_ADJUSTING: TBTT adjustment procedure is ongoing
  28  */
  29 enum mesh_config_capab_flags {
  30         MESHCONF_CAPAB_ACCEPT_PLINKS = BIT(0),
  31         MESHCONF_CAPAB_FORWARDING = BIT(3),
  32         MESHCONF_CAPAB_TBTT_ADJUSTING = BIT(5),
  33 };
  34
  35 /**
  36  * enum mesh_path_flags - mac80211 mesh path flags
  37  *
  38  *
  39  *
  40  * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
  41  * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
  42  * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
  43  *      number
  44  * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
  45  *      modified
  46  * @MESH_PATH_RESOLVED: the mesh path can has been resolved
  47  * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination
  48  * already queued up, waiting for the discovery process to start.
  49  *
  50  * MESH_PATH_RESOLVED is used by the mesh path timer to
  51  * decide when to stop or cancel the mesh path discovery.
  52  */
  53 enum mesh_path_flags {
  54         MESH_PATH_ACTIVE =      BIT(0),
  55         MESH_PATH_RESOLVING =   BIT(1),
  56         MESH_PATH_SN_VALID =    BIT(2),
  57         MESH_PATH_FIXED =       BIT(3),
  58         MESH_PATH_RESOLVED =    BIT(4),
  59         MESH_PATH_REQ_QUEUED =  BIT(5),
  60 };
  61
  62 /**
  63  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
  64  *
  65  *
  66  *
  67  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
  68  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
  69  * to grow.
  70  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
  71  * grow
  72  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
  73  * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
  74  * mesh nodes
  75  */
  76 enum mesh_deferred_task_flags {
  77         MESH_WORK_HOUSEKEEPING,
  78         MESH_WORK_GROW_MPATH_TABLE,
  79         MESH_WORK_GROW_MPP_TABLE,
  80         MESH_WORK_ROOT,
  81         MESH_WORK_DRIFT_ADJUST,
  82 };
  83
  84 /**
  85  * struct mesh_path - mac80211 mesh path structure
  86  *
  87  * @dst: mesh path destination mac address
  88  * @sdata: mesh subif
  89  * @next_hop: mesh neighbor to which frames for this destination will be
  90  *      forwarded
  91  * @timer: mesh path discovery timer
  92  * @frame_queue: pending queue for frames sent to this destination while the
  93  *      path is unresolved
  94  * @sn: target sequence number
  95  * @metric: current metric to this destination
  96  * @hop_count: hops to destination
  97  * @exp_time: in jiffies, when the path will expire or when it expired
  98  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  99  *      retry
 100  * @discovery_retries: number of discovery retries
 101  * @flags: mesh path flags, as specified on &enum mesh_path_flags
 102  * @state_lock: mesh path state lock used to protect changes to the
 103  * mpath itself.  No need to take this lock when adding or removing
 104  * an mpath to a hash bucket on a path table.
 105  * @rann_snd_addr: the RANN sender address
 106  * @rann_metric: the aggregated path metric towards the root node
 107  * @last_preq_to_root: Timestamp of last PREQ sent to root
 108  * @is_root: the destination station of this path is a root node
 109  * @is_gate: the destination station of this path is a mesh gate
 110  *
 111  *
 112  * The combination of dst and sdata is unique in the mesh path table. Since the
 113  * next_hop STA is only protected by RCU as well, deleting the STA must also
 114  * remove/substitute the mesh_path structure and wait until that is no longer
 115  * reachable before destroying the STA completely.
 116  */
 117 struct mesh_path {
 118         u8 dst[ETH_ALEN];
 119         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
 120         struct ieee80211_sub_if_data *sdata;
 121         struct sta_info __rcu *next_hop;
 122         struct timer_list timer;
 123         struct sk_buff_head frame_queue;
 124         struct rcu_head rcu;
 125         u32 sn;
 126         u32 metric;
 127         u8 hop_count;
 128         unsigned long exp_time;
 129         u32 discovery_timeout;
 130         u8 discovery_retries;
 131         enum mesh_path_flags flags;
 132         spinlock_t state_lock;
 133         u8 rann_snd_addr[ETH_ALEN];
 134         u32 rann_metric;
 135         unsigned long last_preq_to_root;
 136         bool is_root;
 137         bool is_gate;
 138 };
 139
 140 /**
 141  * struct mesh_table
 142  *
 143  * @hash_buckets: array of hash buckets of the table
 144  * @hashwlock: array of locks to protect write operations, one per bucket
 145  * @hash_mask: 2^size_order - 1, used to compute hash idx
 146  * @hash_rnd: random value used for hash computations
 147  * @entries: number of entries in the table
 148  * @free_node: function to free nodes of the table
 149  * @copy_node: function to copy nodes of the table
 150  * @size_order: determines size of the table, there will be 2^size_order hash
 151  *      buckets
 152  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 153  *      reached, the table will grow
 154  * @known_gates: list of known mesh gates and their mpaths by the station. The
 155  * gate's mpath may or may not be resolved and active.
 156  *
 157  * rcu_head: RCU head to free the table
 158  */
 159 struct mesh_table {
 160         /* Number of buckets will be 2^N */
 161         struct hlist_head *hash_buckets;
 162         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 163         unsigned int hash_mask;         /* (2^size_order) - 1 */
 164         __u32 hash_rnd;                 /* Used for hash generation */
 165         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 166         void (*free_node) (struct hlist_node *p, bool free_leafs);
 167         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 168         int size_order;
 169         int mean_chain_len;
 170         struct hlist_head *known_gates;
 171         spinlock_t gates_lock;
 172
 173         struct rcu_head rcu_head;
 174 };
 175
 176 /* Recent multicast cache */
 177 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 178 #define RMC_BUCKETS             256
 179 #define RMC_QUEUE_MAX_LEN       4
 180 #define RMC_TIMEOUT             (3 * HZ)
 181
 182 /**
 183  * struct rmc_entry - entry in the Recent Multicast Cache
 184  *
 185  * @seqnum: mesh sequence number of the frame
 186  * @exp_time: expiration time of the entry, in jiffies
 187  * @sa: source address of the frame
 188  *
 189  * The Recent Multicast Cache keeps track of the latest multicast frames that
 190  * have been received by a mesh interface and discards received multicast frames
 191  * that are found in the cache.
 192  */
 193 struct rmc_entry {
 194         struct list_head list;
 195         u32 seqnum;
 196         unsigned long exp_time;
 197         u8 sa[ETH_ALEN];
 198 };
 199
 200 struct mesh_rmc {
 201         struct rmc_entry bucket[RMC_BUCKETS];
 202         u32 idx_mask;
 203 };
 204
 205 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 206 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 207
 208 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 209
 210 #define MESH_PATH_EXPIRE (600 * HZ)
 211
 212 /* Default maximum number of plinks per interface */
 213 #define MESH_MAX_PLINKS         256
 214
 215 /* Maximum number of paths per interface */
 216 #define MESH_MAX_MPATHS         1024
 217
 218 /* Number of frames buffered per destination for unresolved destinations */
 219 #define MESH_FRAME_QUEUE_LEN    10
 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 *addr4or5,
 227                 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 ieee80211_sub_if_data *sdata,
 231                         struct ieee802_11_elems *ie);
 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 int mesh_add_meshconf_ie(struct sk_buff *skb,
 236                          struct ieee80211_sub_if_data *sdata);
 237 int mesh_add_meshid_ie(struct sk_buff *skb,
 238                        struct ieee80211_sub_if_data *sdata);
 239 int mesh_add_rsn_ie(struct sk_buff *skb,
 240                     struct ieee80211_sub_if_data *sdata);
 241 int mesh_add_vendor_ies(struct sk_buff *skb,
 242                         struct ieee80211_sub_if_data *sdata);
 243 int mesh_add_ds_params_ie(struct sk_buff *skb,
 244                           struct ieee80211_sub_if_data *sdata);
 245 int mesh_add_ht_cap_ie(struct sk_buff *skb,
 246                        struct ieee80211_sub_if_data *sdata);
 247 int mesh_add_ht_oper_ie(struct sk_buff *skb,
 248                         struct ieee80211_sub_if_data *sdata);
 249 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 250 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 251 void ieee80211s_init(void);
 252 void ieee80211s_update_metric(struct ieee80211_local *local,
 253                 struct sta_info *sta, struct sk_buff *skb);
 254 void ieee80211s_stop(void);
 255 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 256 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 257 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 258 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 259 struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
 260
 261 /* Mesh paths */
 262 int mesh_nexthop_lookup(struct sk_buff *skb,
 263                 struct ieee80211_sub_if_data *sdata);
 264 int mesh_nexthop_resolve(struct sk_buff *skb,
 265                          struct ieee80211_sub_if_data *sdata);
 266 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 267 struct mesh_path *mesh_path_lookup(u8 *dst,
 268                 struct ieee80211_sub_if_data *sdata);
 269 struct mesh_path *mpp_path_lookup(u8 *dst,
 270                                   struct ieee80211_sub_if_data *sdata);
 271 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 272 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 273                 struct ieee80211_sub_if_data *sdata);
 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 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 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 /* Mesh plinks */
 284 void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 285                            u8 *hw_addr,
 286                            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 void mesh_plink_deactivate(struct sta_info *sta);
 291 int mesh_plink_open(struct sta_info *sta);
 292 void 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
 297 /* Private interfaces */
 298 /* Mesh tables */
 299 void mesh_mpath_table_grow(void);
 300 void mesh_mpp_table_grow(void);
 301 /* Mesh paths */
 302 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 303                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 304 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 305 void mesh_path_flush_pending(struct mesh_path *mpath);
 306 void mesh_path_tx_pending(struct mesh_path *mpath);
 307 int mesh_pathtbl_init(void);
 308 void mesh_pathtbl_unregister(void);
 309 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 310 void mesh_path_timer(unsigned long data);
 311 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 312 void mesh_path_discard_frame(struct sk_buff *skb,
 313                 struct ieee80211_sub_if_data *sdata);
 314 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 315 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 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 extern int mesh_allocated;
 323
 324 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 325 {
 326         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 327                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 328 }
 329
 330 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 331 {
 332         return (min_t(long, mesh_plink_free_count(sdata),
 333                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 334 }
 335
 336 static inline void mesh_path_activate(struct mesh_path *mpath)
 337 {
 338         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 339 }
 340
 341 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 342 {
 343         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 344 }
 345
 346 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 347
 348 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 349 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 350 void mesh_plink_quiesce(struct sta_info *sta);
 351 void mesh_plink_restart(struct sta_info *sta);
 352 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 353 void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
 354 #else
 355 #define mesh_allocated  0
 356 static inline void
 357 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 358 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 359 {}
 360 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 361 {}
 362 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 363 static inline void mesh_plink_restart(struct sta_info *sta) {}
 364 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 365 { return false; }
 366 static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 367 {}
 368 #endif
 369
 370 #endif /* IEEE80211S_H */