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  */
  60 enum mesh_deferred_task_flags {
  61         MESH_WORK_HOUSEKEEPING,
  62         MESH_WORK_GROW_MPATH_TABLE,
  63         MESH_WORK_GROW_MPP_TABLE,
  64         MESH_WORK_ROOT,
  65 };
  66
  67 /**
  68  * struct mesh_path - mac80211 mesh path structure
  69  *
  70  * @dst: mesh path destination mac address
  71  * @sdata: mesh subif
  72  * @next_hop: mesh neighbor to which frames for this destination will be
  73  *      forwarded
  74  * @timer: mesh path discovery timer
  75  * @frame_queue: pending queue for frames sent to this destination while the
  76  *      path is unresolved
  77  * @sn: target sequence number
  78  * @metric: current metric to this destination
  79  * @hop_count: hops to destination
  80  * @exp_time: in jiffies, when the path will expire or when it expired
  81  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  82  *      retry
  83  * @discovery_retries: number of discovery retries
  84  * @flags: mesh path flags, as specified on &enum mesh_path_flags
  85  * @state_lock: mesh path state lock used to protect changes to the
  86  * mpath itself.  No need to take this lock when adding or removing
  87  * an mpath to a hash bucket on a path table.
  88  * @is_gate: the destination station of this path is a mesh gate
  89  *
  90  *
  91  * The combination of dst and sdata is unique in the mesh path table. Since the
  92  * next_hop STA is only protected by RCU as well, deleting the STA must also
  93  * remove/substitute the mesh_path structure and wait until that is no longer
  94  * reachable before destroying the STA completely.
  95  */
  96 struct mesh_path {
  97         u8 dst[ETH_ALEN];
  98         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  99         struct ieee80211_sub_if_data *sdata;
 100         struct sta_info __rcu *next_hop;
 101         struct timer_list timer;
 102         struct sk_buff_head frame_queue;
 103         struct rcu_head rcu;
 104         u32 sn;
 105         u32 metric;
 106         u8 hop_count;
 107         unsigned long exp_time;
 108         u32 discovery_timeout;
 109         u8 discovery_retries;
 110         enum mesh_path_flags flags;
 111         spinlock_t state_lock;
 112         bool is_gate;
 113 };
 114
 115 /**
 116  * struct mesh_table
 117  *
 118  * @hash_buckets: array of hash buckets of the table
 119  * @hashwlock: array of locks to protect write operations, one per bucket
 120  * @hash_mask: 2^size_order - 1, used to compute hash idx
 121  * @hash_rnd: random value used for hash computations
 122  * @entries: number of entries in the table
 123  * @free_node: function to free nodes of the table
 124  * @copy_node: function to copy nodes of the table
 125  * @size_order: determines size of the table, there will be 2^size_order hash
 126  *      buckets
 127  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 128  *      reached, the table will grow
 129  * @known_gates: list of known mesh gates and their mpaths by the station. The
 130  * gate's mpath may or may not be resolved and active.
 131  *
 132  * rcu_head: RCU head to free the table
 133  */
 134 struct mesh_table {
 135         /* Number of buckets will be 2^N */
 136         struct hlist_head *hash_buckets;
 137         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 138         unsigned int hash_mask;         /* (2^size_order) - 1 */
 139         __u32 hash_rnd;                 /* Used for hash generation */
 140         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 141         void (*free_node) (struct hlist_node *p, bool free_leafs);
 142         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 143         int size_order;
 144         int mean_chain_len;
 145         struct hlist_head *known_gates;
 146         spinlock_t gates_lock;
 147
 148         struct rcu_head rcu_head;
 149 };
 150
 151 /* Recent multicast cache */
 152 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 153 #define RMC_BUCKETS             256
 154 #define RMC_QUEUE_MAX_LEN       4
 155 #define RMC_TIMEOUT             (3 * HZ)
 156
 157 /**
 158  * struct rmc_entry - entry in the Recent Multicast Cache
 159  *
 160  * @seqnum: mesh sequence number of the frame
 161  * @exp_time: expiration time of the entry, in jiffies
 162  * @sa: source address of the frame
 163  *
 164  * The Recent Multicast Cache keeps track of the latest multicast frames that
 165  * have been received by a mesh interface and discards received multicast frames
 166  * that are found in the cache.
 167  */
 168 struct rmc_entry {
 169         struct list_head list;
 170         u32 seqnum;
 171         unsigned long exp_time;
 172         u8 sa[ETH_ALEN];
 173 };
 174
 175 struct mesh_rmc {
 176         struct rmc_entry bucket[RMC_BUCKETS];
 177         u32 idx_mask;
 178 };
 179
 180 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 181 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 182
 183 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 184
 185 #define MESH_PATH_EXPIRE (600 * HZ)
 186
 187 /* Default maximum number of plinks per interface */
 188 #define MESH_MAX_PLINKS         256
 189
 190 /* Maximum number of paths per interface */
 191 #define MESH_MAX_MPATHS         1024
 192
 193 /* Public interfaces */
 194 /* Various */
 195 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 196                                   const u8 *da, const u8 *sa);
 197 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 198                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 199                 char *addr6);
 200 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 201                 struct ieee80211_sub_if_data *sdata);
 202 bool mesh_matches_local(struct ieee802_11_elems *ie,
 203                 struct ieee80211_sub_if_data *sdata);
 204 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 205 void mesh_mgmt_ies_add(struct sk_buff *skb,
 206                 struct ieee80211_sub_if_data *sdata);
 207 int mesh_add_meshconf_ie(struct sk_buff *skb,
 208                          struct ieee80211_sub_if_data *sdata);
 209 int mesh_add_meshid_ie(struct sk_buff *skb,
 210                        struct ieee80211_sub_if_data *sdata);
 211 int mesh_add_rsn_ie(struct sk_buff *skb,
 212                     struct ieee80211_sub_if_data *sdata);
 213 int mesh_add_vendor_ies(struct sk_buff *skb,
 214                         struct ieee80211_sub_if_data *sdata);
 215 int mesh_add_ds_params_ie(struct sk_buff *skb,
 216                           struct ieee80211_sub_if_data *sdata);
 217 int mesh_add_ht_cap_ie(struct sk_buff *skb,
 218                        struct ieee80211_sub_if_data *sdata);
 219 int mesh_add_ht_info_ie(struct sk_buff *skb,
 220                         struct ieee80211_sub_if_data *sdata);
 221 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 222 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 223 void ieee80211s_init(void);
 224 void ieee80211s_update_metric(struct ieee80211_local *local,
 225                 struct sta_info *stainfo, struct sk_buff *skb);
 226 void ieee80211s_stop(void);
 227 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 228 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 229 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 230 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 231
 232 /* Mesh paths */
 233 int mesh_nexthop_lookup(struct sk_buff *skb,
 234                 struct ieee80211_sub_if_data *sdata);
 235 int mesh_nexthop_resolve(struct sk_buff *skb,
 236                          struct ieee80211_sub_if_data *sdata);
 237 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 238 struct mesh_path *mesh_path_lookup(u8 *dst,
 239                 struct ieee80211_sub_if_data *sdata);
 240 struct mesh_path *mpp_path_lookup(u8 *dst,
 241                                   struct ieee80211_sub_if_data *sdata);
 242 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 243 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 244                 struct ieee80211_sub_if_data *sdata);
 245 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 246 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 247 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 248                 struct ieee80211_mgmt *mgmt, size_t len);
 249 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 250
 251 int mesh_path_add_gate(struct mesh_path *mpath);
 252 int mesh_path_send_to_gates(struct mesh_path *mpath);
 253 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 254 /* Mesh plinks */
 255 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 256                 struct ieee80211_sub_if_data *sdata,
 257                 struct ieee802_11_elems *ie);
 258 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 259 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 260 void mesh_plink_broken(struct sta_info *sta);
 261 void mesh_plink_deactivate(struct sta_info *sta);
 262 int mesh_plink_open(struct sta_info *sta);
 263 void mesh_plink_block(struct sta_info *sta);
 264 void 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 */
 270 void mesh_mpath_table_grow(void);
 271 void mesh_mpp_table_grow(void);
 272 /* Mesh paths */
 273 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 274                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 275 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 276 void mesh_path_flush_pending(struct mesh_path *mpath);
 277 void mesh_path_tx_pending(struct mesh_path *mpath);
 278 int mesh_pathtbl_init(void);
 279 void mesh_pathtbl_unregister(void);
 280 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 281 void mesh_path_timer(unsigned long data);
 282 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 283 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 284 void mesh_path_discard_frame(struct sk_buff *skb,
 285                 struct ieee80211_sub_if_data *sdata);
 286 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 287 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 288 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 289
 290 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 291 extern int mesh_paths_generation;
 292
 293 #ifdef CONFIG_MAC80211_MESH
 294 extern int mesh_allocated;
 295
 296 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 297 {
 298         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 299                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 300 }
 301
 302 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 303 {
 304         return (min_t(long, mesh_plink_free_count(sdata),
 305                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 306 }
 307
 308 static inline void mesh_path_activate(struct mesh_path *mpath)
 309 {
 310         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 311 }
 312
 313 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 314 {
 315         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 316 }
 317
 318 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 319
 320 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 321 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 322 void mesh_plink_quiesce(struct sta_info *sta);
 323 void mesh_plink_restart(struct sta_info *sta);
 324 #else
 325 #define mesh_allocated  0
 326 static inline void
 327 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 328 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 329 {}
 330 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 331 {}
 332 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 333 static inline void mesh_plink_restart(struct sta_info *sta) {}
 334 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 335 { return false; }
 336 #endif
 337
 338 #endif /* IEEE80211S_H */