LXR linux/net/mac80211/mesh.h

   1/*
   2 * Copyright (c) 2008 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_DSN_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_DSN_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 */
  57enum mesh_deferred_task_flags {
  58        MESH_WORK_HOUSEKEEPING,
  59        MESH_WORK_GROW_MPATH_TABLE,
  60        MESH_WORK_GROW_MPP_TABLE,
  61};
  62
  63/**
  64 * struct mesh_path - mac80211 mesh path structure
  65 *
  66 * @dst: mesh path destination mac address
  67 * @sdata: mesh subif
  68 * @next_hop: mesh neighbor to which frames for this destination will be
  69 *      forwarded
  70 * @timer: mesh path discovery timer
  71 * @frame_queue: pending queue for frames sent to this destination while the
  72 *      path is unresolved
  73 * @dsn: destination sequence number of the destination
  74 * @metric: current metric to this destination
  75 * @hop_count: hops to destination
  76 * @exp_time: in jiffies, when the path will expire or when it expired
  77 * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  78 *      retry
  79 * @discovery_retries: number of discovery retries
  80 * @flags: mesh path flags, as specified on &enum mesh_path_flags
  81 * @state_lock: mesh path state lock
  82 *
  83 *
  84 * The combination of dst and sdata is unique in the mesh path table. Since the
  85 * next_hop STA is only protected by RCU as well, deleting the STA must also
  86 * remove/substitute the mesh_path structure and wait until that is no longer
  87 * reachable before destroying the STA completely.
  88 */
  89struct mesh_path {
  90        u8 dst[ETH_ALEN];
  91        u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  92        struct ieee80211_sub_if_data *sdata;
  93        struct sta_info *next_hop;
  94        struct timer_list timer;
  95        struct sk_buff_head frame_queue;
  96        struct rcu_head rcu;
  97        u32 dsn;
  98        u32 metric;
  99        u8 hop_count;
 100        unsigned long exp_time;
 101        u32 discovery_timeout;
 102        u8 discovery_retries;
 103        enum mesh_path_flags flags;
 104        spinlock_t state_lock;
 105};
 106
 107/**
 108 * struct mesh_table
 109 *
 110 * @hash_buckets: array of hash buckets of the table
 111 * @hashwlock: array of locks to protect write operations, one per bucket
 112 * @hash_mask: 2^size_order - 1, used to compute hash idx
 113 * @hash_rnd: random value used for hash computations
 114 * @entries: number of entries in the table
 115 * @free_node: function to free nodes of the table
 116 * @copy_node: fuction to copy nodes of the table
 117 * @size_order: determines size of the table, there will be 2^size_order hash
 118 *      buckets
 119 * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 120 *      reached, the table will grow
 121 */
 122struct mesh_table {
 123        /* Number of buckets will be 2^N */
 124        struct hlist_head *hash_buckets;
 125        spinlock_t *hashwlock;          /* One per bucket, for add/del */
 126        unsigned int hash_mask;         /* (2^size_order) - 1 */
 127        __u32 hash_rnd;                 /* Used for hash generation */
 128        atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 129        void (*free_node) (struct hlist_node *p, bool free_leafs);
 130        int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 131        int size_order;
 132        int mean_chain_len;
 133};
 134
 135/* Recent multicast cache */
 136/* RMC_BUCKETS must be a power of 2, maximum 256 */
 137#define RMC_BUCKETS             256
 138#define RMC_QUEUE_MAX_LEN       4
 139#define RMC_TIMEOUT             (3 * HZ)
 140
 141/**
 142 * struct rmc_entry - entry in the Recent Multicast Cache
 143 *
 144 * @seqnum: mesh sequence number of the frame
 145 * @exp_time: expiration time of the entry, in jiffies
 146 * @sa: source address of the frame
 147 *
 148 * The Recent Multicast Cache keeps track of the latest multicast frames that
 149 * have been received by a mesh interface and discards received multicast frames
 150 * that are found in the cache.
 151 */
 152struct rmc_entry {
 153        struct list_head list;
 154        u32 seqnum;
 155        unsigned long exp_time;
 156        u8 sa[ETH_ALEN];
 157};
 158
 159struct mesh_rmc {
 160        struct rmc_entry bucket[RMC_BUCKETS];
 161        u32 idx_mask;
 162};
 163
 164
 165/*
 166 * MESH_CFG_COMP_LEN Includes:
 167 *      - Active path selection protocol ID.
 168 *      - Active path selection metric ID.
 169 *      - Congestion control mode identifier.
 170 *      - Channel precedence.
 171 * Does not include mesh capabilities, which may vary across nodes in the same
 172 * mesh
 173 */
 174#define MESH_CFG_CMP_LEN        (IEEE80211_MESH_CONFIG_LEN - 2)
 175
 176/* Default values, timeouts in ms */
 177#define MESH_TTL                5
 178#define MESH_MAX_RETR           3
 179#define MESH_RET_T              100
 180#define MESH_CONF_T             100
 181#define MESH_HOLD_T             100
 182
 183#define MESH_PATH_TIMEOUT       5000
 184/* Minimum interval between two consecutive PREQs originated by the same
 185 * interface
 186 */
 187#define MESH_PREQ_MIN_INT       10
 188#define MESH_DIAM_TRAVERSAL_TIME 50
 189/* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their
 190 * expiration
 191 */
 192#define MESH_PATH_REFRESH_TIME                  1000
 193#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
 194#define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 195
 196#define MESH_MAX_PREQ_RETRIES 4
 197#define MESH_PATH_EXPIRE (600 * HZ)
 198
 199/* Default maximum number of established plinks per interface */
 200#define MESH_MAX_ESTAB_PLINKS   32
 201
 202/* Default maximum number of plinks per interface */
 203#define MESH_MAX_PLINKS         256
 204
 205/* Maximum number of paths per interface */
 206#define MESH_MAX_MPATHS         1024
 207
 208/* Pending ANA approval */
 209#define PLINK_CATEGORY          30
 210#define MESH_PATH_SEL_CATEGORY  32
 211
 212/* Public interfaces */
 213/* Various */
 214int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 215                char *da, char *sa);
 216int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 217                struct ieee80211_sub_if_data *sdata, char *addr4,
 218                char *addr5, char *addr6);
 219int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 220                struct ieee80211_sub_if_data *sdata);
 221bool mesh_matches_local(struct ieee802_11_elems *ie,
 222                struct ieee80211_sub_if_data *sdata);
 223void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 224void mesh_mgmt_ies_add(struct sk_buff *skb,
 225                struct ieee80211_sub_if_data *sdata);
 226void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 227int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 228void ieee80211s_init(void);
 229void ieee80211s_update_metric(struct ieee80211_local *local,
 230                struct sta_info *stainfo, struct sk_buff *skb);
 231void ieee80211s_stop(void);
 232void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 233ieee80211_rx_result
 234ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb);
 235void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 236void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 237
 238/* Mesh paths */
 239int mesh_nexthop_lookup(struct sk_buff *skb,
 240                struct ieee80211_sub_if_data *sdata);
 241void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 242struct mesh_path *mesh_path_lookup(u8 *dst,
 243                struct ieee80211_sub_if_data *sdata);
 244struct mesh_path *mpp_path_lookup(u8 *dst,
 245                                  struct ieee80211_sub_if_data *sdata);
 246int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 247struct mesh_path *mesh_path_lookup_by_idx(int idx,
 248                struct ieee80211_sub_if_data *sdata);
 249void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 250void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 251void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
 252void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 253                struct ieee80211_mgmt *mgmt, size_t len);
 254int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 255/* Mesh plinks */
 256void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 257                struct ieee80211_sub_if_data *sdata, bool add);
 258bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 259void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 260void mesh_plink_broken(struct sta_info *sta);
 261void mesh_plink_deactivate(struct sta_info *sta);
 262int mesh_plink_open(struct sta_info *sta);
 263void mesh_plink_block(struct sta_info *sta);
 264void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 265                         struct ieee80211_mgmt *mgmt, size_t len,
 266                         struct ieee80211_rx_status *rx_status);
 267
 268/* Private interfaces */
 269/* Mesh tables */
 270struct mesh_table *mesh_table_alloc(int size_order);
 271void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
 272void mesh_mpath_table_grow(void);
 273void mesh_mpp_table_grow(void);
 274u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
 275                struct mesh_table *tbl);
 276/* Mesh paths */
 277int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
 278                struct ieee80211_sub_if_data *sdata);
 279void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 280void mesh_path_flush_pending(struct mesh_path *mpath);
 281void mesh_path_tx_pending(struct mesh_path *mpath);
 282int mesh_pathtbl_init(void);
 283void mesh_pathtbl_unregister(void);
 284int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 285void mesh_path_timer(unsigned long data);
 286void mesh_path_flush_by_nexthop(struct sta_info *sta);
 287void mesh_path_discard_frame(struct sk_buff *skb,
 288                struct ieee80211_sub_if_data *sdata);
 289void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 290void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 291
 292extern int mesh_paths_generation;
 293
 294#ifdef CONFIG_MAC80211_MESH
 295extern int mesh_allocated;
 296
 297static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 298{
 299        return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 300               atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 301}
 302
 303static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 304{
 305        return (min_t(long, mesh_plink_free_count(sdata),
 306                   MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 307}
 308
 309static inline void mesh_path_activate(struct mesh_path *mpath)
 310{
 311        mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 312}
 313
 314#define for_each_mesh_entry(x, p, node, i) \
 315        for (i = 0; i <= x->hash_mask; i++) \
 316                hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
 317
 318void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 319
 320void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 321void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 322void mesh_plink_quiesce(struct sta_info *sta);
 323void mesh_plink_restart(struct sta_info *sta);
 324#else
 325#define mesh_allocated  0
 326static inline void
 327ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 328static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 329{}
 330static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 331{}
 332static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 333static inline void mesh_plink_restart(struct sta_info *sta) {}
 334#endif
 335
 336#endif /* IEEE80211S_H */
 337