LXR linux/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 */
  29enum 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 */
  53enum 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 */
  76enum 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 */
 117struct 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 */
 159struct 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 */
 193struct rmc_entry {
 194        struct list_head list;
 195        u32 seqnum;
 196        unsigned long exp_time;
 197        u8 sa[ETH_ALEN];
 198};
 199
 200struct 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 */
 223int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 224                                  const u8 *da, const u8 *sa);
 225int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 226                struct ieee80211_sub_if_data *sdata, char *addr4or5,
 227                char *addr6);
 228int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 229                struct ieee80211_sub_if_data *sdata);
 230bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
 231                        struct ieee802_11_elems *ie);
 232void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 233void mesh_mgmt_ies_add(struct sk_buff *skb,
 234                struct ieee80211_sub_if_data *sdata);
 235int mesh_add_meshconf_ie(struct sk_buff *skb,
 236                         struct ieee80211_sub_if_data *sdata);
 237int mesh_add_meshid_ie(struct sk_buff *skb,
 238                       struct ieee80211_sub_if_data *sdata);
 239int mesh_add_rsn_ie(struct sk_buff *skb,
 240                    struct ieee80211_sub_if_data *sdata);
 241int mesh_add_vendor_ies(struct sk_buff *skb,
 242                        struct ieee80211_sub_if_data *sdata);
 243int mesh_add_ds_params_ie(struct sk_buff *skb,
 244                          struct ieee80211_sub_if_data *sdata);
 245int mesh_add_ht_cap_ie(struct sk_buff *skb,
 246                       struct ieee80211_sub_if_data *sdata);
 247int mesh_add_ht_oper_ie(struct sk_buff *skb,
 248                        struct ieee80211_sub_if_data *sdata);
 249void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 250int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 251void ieee80211s_init(void);
 252void ieee80211s_update_metric(struct ieee80211_local *local,
 253                struct sta_info *sta, struct sk_buff *skb);
 254void ieee80211s_stop(void);
 255void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 256void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 257void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 258void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 259struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);
 260
 261/* Mesh paths */
 262int mesh_nexthop_lookup(struct sk_buff *skb,
 263                struct ieee80211_sub_if_data *sdata);
 264int mesh_nexthop_resolve(struct sk_buff *skb,
 265                         struct ieee80211_sub_if_data *sdata);
 266void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 267struct mesh_path *mesh_path_lookup(u8 *dst,
 268                struct ieee80211_sub_if_data *sdata);
 269struct mesh_path *mpp_path_lookup(u8 *dst,
 270                                  struct ieee80211_sub_if_data *sdata);
 271int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 272struct mesh_path *mesh_path_lookup_by_idx(int idx,
 273                struct ieee80211_sub_if_data *sdata);
 274void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 275void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 276void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 277                struct ieee80211_mgmt *mgmt, size_t len);
 278int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 279
 280int mesh_path_add_gate(struct mesh_path *mpath);
 281int mesh_path_send_to_gates(struct mesh_path *mpath);
 282int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 283/* Mesh plinks */
 284void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
 285                           u8 *hw_addr,
 286                           struct ieee802_11_elems *ie);
 287bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 288u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 289void mesh_plink_broken(struct sta_info *sta);
 290void mesh_plink_deactivate(struct sta_info *sta);
 291int mesh_plink_open(struct sta_info *sta);
 292void mesh_plink_block(struct sta_info *sta);
 293void 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 */
 299void mesh_mpath_table_grow(void);
 300void mesh_mpp_table_grow(void);
 301/* Mesh paths */
 302int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 303                       const u8 *ra, struct ieee80211_sub_if_data *sdata);
 304void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 305void mesh_path_flush_pending(struct mesh_path *mpath);
 306void mesh_path_tx_pending(struct mesh_path *mpath);
 307int mesh_pathtbl_init(void);
 308void mesh_pathtbl_unregister(void);
 309int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 310void mesh_path_timer(unsigned long data);
 311void mesh_path_flush_by_nexthop(struct sta_info *sta);
 312void mesh_path_discard_frame(struct sk_buff *skb,
 313                struct ieee80211_sub_if_data *sdata);
 314void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 315void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 316void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 317
 318bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 319extern int mesh_paths_generation;
 320
 321#ifdef CONFIG_MAC80211_MESH
 322extern int mesh_allocated;
 323
 324static 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
 330static 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
 336static inline void mesh_path_activate(struct mesh_path *mpath)
 337{
 338        mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 339}
 340
 341static 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
 346void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 347
 348void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 349void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 350void mesh_plink_quiesce(struct sta_info *sta);
 351void mesh_plink_restart(struct sta_info *sta);
 352void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 353void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata);
 354#else
 355#define mesh_allocated  0
 356static inline void
 357ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 358static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 359{}
 360static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 361{}
 362static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 363static inline void mesh_plink_restart(struct sta_info *sta) {}
 364static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 365{ return false; }
 366static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
 367{}
 368#endif
 369
 370#endif /* IEEE80211S_H */
 371