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 <asm/unaligned.h>
  17#include "ieee80211_i.h"
  18
  19
  20/* Data structures */
  21
  22/**
  23 * enum mesh_path_flags - mac80211 mesh path flags
  24 *
  25 *
  26 *
  27 * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
  28 * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path
  29 * @MESH_PATH_SN_VALID: the mesh path contains a valid destination sequence
  30 *      number
  31 * @MESH_PATH_FIXED: the mesh path has been manually set and should not be
  32 *      modified
  33 * @MESH_PATH_RESOLVED: the mesh path can has been resolved
  34 *
  35 * MESH_PATH_RESOLVED is used by the mesh path timer to
  36 * decide when to stop or cancel the mesh path discovery.
  37 */
  38enum mesh_path_flags {
  39        MESH_PATH_ACTIVE =      BIT(0),
  40        MESH_PATH_RESOLVING =   BIT(1),
  41        MESH_PATH_SN_VALID =    BIT(2),
  42        MESH_PATH_FIXED =       BIT(3),
  43        MESH_PATH_RESOLVED =    BIT(4),
  44};
  45
  46/**
  47 * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
  48 *
  49 *
  50 *
  51 * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
  52 * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
  53 * to grow.
  54 * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
  55 * grow
  56 * @MESH_WORK_ROOT: the mesh root station needs to send a frame
  57 */
  58enum mesh_deferred_task_flags {
  59        MESH_WORK_HOUSEKEEPING,
  60        MESH_WORK_GROW_MPATH_TABLE,
  61        MESH_WORK_GROW_MPP_TABLE,
  62        MESH_WORK_ROOT,
  63};
  64
  65/**
  66 * struct mesh_path - mac80211 mesh path structure
  67 *
  68 * @dst: mesh path destination mac address
  69 * @sdata: mesh subif
  70 * @next_hop: mesh neighbor to which frames for this destination will be
  71 *      forwarded
  72 * @timer: mesh path discovery timer
  73 * @frame_queue: pending queue for frames sent to this destination while the
  74 *      path is unresolved
  75 * @sn: target sequence number
  76 * @metric: current metric to this destination
  77 * @hop_count: hops to destination
  78 * @exp_time: in jiffies, when the path will expire or when it expired
  79 * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  80 *      retry
  81 * @discovery_retries: number of discovery retries
  82 * @flags: mesh path flags, as specified on &enum mesh_path_flags
  83 * @state_lock: mesh path state lock
  84 *
  85 *
  86 * The combination of dst and sdata is unique in the mesh path table. Since the
  87 * next_hop STA is only protected by RCU as well, deleting the STA must also
  88 * remove/substitute the mesh_path structure and wait until that is no longer
  89 * reachable before destroying the STA completely.
  90 */
  91struct mesh_path {
  92        u8 dst[ETH_ALEN];
  93        u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  94        struct ieee80211_sub_if_data *sdata;
  95        struct sta_info *next_hop;
  96        struct timer_list timer;
  97        struct sk_buff_head frame_queue;
  98        struct rcu_head rcu;
  99        u32 sn;
 100        u32 metric;
 101        u8 hop_count;
 102        unsigned long exp_time;
 103        u32 discovery_timeout;
 104        u8 discovery_retries;
 105        enum mesh_path_flags flags;
 106        spinlock_t state_lock;
 107};
 108
 109/**
 110 * struct mesh_table
 111 *
 112 * @hash_buckets: array of hash buckets of the table
 113 * @hashwlock: array of locks to protect write operations, one per bucket
 114 * @hash_mask: 2^size_order - 1, used to compute hash idx
 115 * @hash_rnd: random value used for hash computations
 116 * @entries: number of entries in the table
 117 * @free_node: function to free nodes of the table
 118 * @copy_node: function to copy nodes of the table
 119 * @size_order: determines size of the table, there will be 2^size_order hash
 120 *      buckets
 121 * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 122 *      reached, the table will grow
 123 */
 124struct mesh_table {
 125        /* Number of buckets will be 2^N */
 126        struct hlist_head *hash_buckets;
 127        spinlock_t *hashwlock;          /* One per bucket, for add/del */
 128        unsigned int hash_mask;         /* (2^size_order) - 1 */
 129        __u32 hash_rnd;                 /* Used for hash generation */
 130        atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 131        void (*free_node) (struct hlist_node *p, bool free_leafs);
 132        int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 133        int size_order;
 134        int mean_chain_len;
 135};
 136
 137/* Recent multicast cache */
 138/* RMC_BUCKETS must be a power of 2, maximum 256 */
 139#define RMC_BUCKETS             256
 140#define RMC_QUEUE_MAX_LEN       4
 141#define RMC_TIMEOUT             (3 * HZ)
 142
 143/**
 144 * struct rmc_entry - entry in the Recent Multicast Cache
 145 *
 146 * @seqnum: mesh sequence number of the frame
 147 * @exp_time: expiration time of the entry, in jiffies
 148 * @sa: source address of the frame
 149 *
 150 * The Recent Multicast Cache keeps track of the latest multicast frames that
 151 * have been received by a mesh interface and discards received multicast frames
 152 * that are found in the cache.
 153 */
 154struct rmc_entry {
 155        struct list_head list;
 156        u32 seqnum;
 157        unsigned long exp_time;
 158        u8 sa[ETH_ALEN];
 159};
 160
 161struct mesh_rmc {
 162        struct rmc_entry bucket[RMC_BUCKETS];
 163        u32 idx_mask;
 164};
 165
 166
 167/*
 168 * MESH_CFG_COMP_LEN Includes:
 169 *      - Active path selection protocol ID.
 170 *      - Active path selection metric ID.
 171 *      - Congestion control mode identifier.
 172 *      - Channel precedence.
 173 * Does not include mesh capabilities, which may vary across nodes in the same
 174 * mesh
 175 */
 176#define MESH_CFG_CMP_LEN        (IEEE80211_MESH_CONFIG_LEN - 2)
 177
 178/* Default values, timeouts in ms */
 179#define MESH_TTL                31
 180#define MESH_MAX_RETR           3
 181#define MESH_RET_T              100
 182#define MESH_CONF_T             100
 183#define MESH_HOLD_T             100
 184
 185#define MESH_PATH_TIMEOUT       5000
 186/* Minimum interval between two consecutive PREQs originated by the same
 187 * interface
 188 */
 189#define MESH_PREQ_MIN_INT       10
 190#define MESH_DIAM_TRAVERSAL_TIME 50
 191/* A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds before
 192 * timing out.  This way it will remain ACTIVE and no data frames will be
 193 * unnecesarily held in the pending queue.
 194 */
 195#define MESH_PATH_REFRESH_TIME                  1000
 196#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
 197#define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 198
 199#define MESH_MAX_PREQ_RETRIES 4
 200#define MESH_PATH_EXPIRE (600 * HZ)
 201
 202/* Default maximum number of established plinks per interface */
 203#define MESH_MAX_ESTAB_PLINKS   32
 204
 205/* Default maximum number of plinks per interface */
 206#define MESH_MAX_PLINKS         256
 207
 208/* Maximum number of paths per interface */
 209#define MESH_MAX_MPATHS         1024
 210
 211/* Pending ANA approval */
 212#define MESH_PATH_SEL_ACTION    0
 213
 214/* PERR reason codes */
 215#define PEER_RCODE_UNSPECIFIED  11
 216#define PERR_RCODE_NO_ROUTE     12
 217#define PERR_RCODE_DEST_UNREACH 13
 218
 219/* Public interfaces */
 220/* Various */
 221int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 222                                  const u8 *da, const u8 *sa);
 223int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 224                struct ieee80211_sub_if_data *sdata, char *addr4,
 225                char *addr5, char *addr6);
 226int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 227                struct ieee80211_sub_if_data *sdata);
 228bool mesh_matches_local(struct ieee802_11_elems *ie,
 229                struct ieee80211_sub_if_data *sdata);
 230void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 231void mesh_mgmt_ies_add(struct sk_buff *skb,
 232                struct ieee80211_sub_if_data *sdata);
 233void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 234int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 235void ieee80211s_init(void);
 236void ieee80211s_update_metric(struct ieee80211_local *local,
 237                struct sta_info *stainfo, struct sk_buff *skb);
 238void ieee80211s_stop(void);
 239void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 240void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 241void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 242void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 243
 244/* Mesh paths */
 245int mesh_nexthop_lookup(struct sk_buff *skb,
 246                struct ieee80211_sub_if_data *sdata);
 247void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 248struct mesh_path *mesh_path_lookup(u8 *dst,
 249                struct ieee80211_sub_if_data *sdata);
 250struct mesh_path *mpp_path_lookup(u8 *dst,
 251                                  struct ieee80211_sub_if_data *sdata);
 252int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 253struct mesh_path *mesh_path_lookup_by_idx(int idx,
 254                struct ieee80211_sub_if_data *sdata);
 255void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 256void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 257void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
 258void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 259                struct ieee80211_mgmt *mgmt, size_t len);
 260int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 261/* Mesh plinks */
 262void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 263                struct ieee80211_sub_if_data *sdata, bool add);
 264bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 265void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 266void mesh_plink_broken(struct sta_info *sta);
 267void mesh_plink_deactivate(struct sta_info *sta);
 268int mesh_plink_open(struct sta_info *sta);
 269void mesh_plink_block(struct sta_info *sta);
 270void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 271                         struct ieee80211_mgmt *mgmt, size_t len,
 272                         struct ieee80211_rx_status *rx_status);
 273
 274/* Private interfaces */
 275/* Mesh tables */
 276struct mesh_table *mesh_table_alloc(int size_order);
 277void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
 278void mesh_mpath_table_grow(void);
 279void mesh_mpp_table_grow(void);
 280u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
 281                struct mesh_table *tbl);
 282/* Mesh paths */
 283int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 284                       const u8 *ra, struct ieee80211_sub_if_data *sdata);
 285void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 286void mesh_path_flush_pending(struct mesh_path *mpath);
 287void mesh_path_tx_pending(struct mesh_path *mpath);
 288int mesh_pathtbl_init(void);
 289void mesh_pathtbl_unregister(void);
 290int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 291void mesh_path_timer(unsigned long data);
 292void mesh_path_flush_by_nexthop(struct sta_info *sta);
 293void mesh_path_discard_frame(struct sk_buff *skb,
 294                struct ieee80211_sub_if_data *sdata);
 295void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 296void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 297void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 298
 299extern int mesh_paths_generation;
 300
 301#ifdef CONFIG_MAC80211_MESH
 302extern int mesh_allocated;
 303
 304static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 305{
 306        return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 307               atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 308}
 309
 310static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 311{
 312        return (min_t(long, mesh_plink_free_count(sdata),
 313                   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 314}
 315
 316static inline void mesh_path_activate(struct mesh_path *mpath)
 317{
 318        mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 319}
 320
 321#define for_each_mesh_entry(x, p, node, i) \
 322        for (i = 0; i <= x->hash_mask; i++) \
 323                hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
 324
 325void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 326
 327void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 328void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 329void mesh_plink_quiesce(struct sta_info *sta);
 330void mesh_plink_restart(struct sta_info *sta);
 331#else
 332#define mesh_allocated  0
 333static inline void
 334ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 335static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 336{}
 337static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 338{}
 339static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 340static inline void mesh_plink_restart(struct sta_info *sta) {}
 341#endif
 342
 343#endif /* IEEE80211S_H */
 344