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  * @rann_snd_addr: the RANN sender address
  89  * @is_root: the destination station of this path is a root node
  90  * @is_gate: the destination station of this path is a mesh gate
  91  *
  92  *
  93  * The combination of dst and sdata is unique in the mesh path table. Since the
  94  * next_hop STA is only protected by RCU as well, deleting the STA must also
  95  * remove/substitute the mesh_path structure and wait until that is no longer
  96  * reachable before destroying the STA completely.
  97  */
  98 struct mesh_path {
  99         u8 dst[ETH_ALEN];
 100         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
 101         struct ieee80211_sub_if_data *sdata;
 102         struct sta_info __rcu *next_hop;
 103         struct timer_list timer;
 104         struct sk_buff_head frame_queue;
 105         struct rcu_head rcu;
 106         u32 sn;
 107         u32 metric;
 108         u8 hop_count;
 109         unsigned long exp_time;
 110         u32 discovery_timeout;
 111         u8 discovery_retries;
 112         enum mesh_path_flags flags;
 113         spinlock_t state_lock;
 114         u8 rann_snd_addr[ETH_ALEN];
 115         bool is_root;
 116         bool is_gate;
 117 };
 118
 119 /**
 120  * struct mesh_table
 121  *
 122  * @hash_buckets: array of hash buckets of the table
 123  * @hashwlock: array of locks to protect write operations, one per bucket
 124  * @hash_mask: 2^size_order - 1, used to compute hash idx
 125  * @hash_rnd: random value used for hash computations
 126  * @entries: number of entries in the table
 127  * @free_node: function to free nodes of the table
 128  * @copy_node: function to copy nodes of the table
 129  * @size_order: determines size of the table, there will be 2^size_order hash
 130  *      buckets
 131  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 132  *      reached, the table will grow
 133  * @known_gates: list of known mesh gates and their mpaths by the station. The
 134  * gate's mpath may or may not be resolved and active.
 135  *
 136  * rcu_head: RCU head to free the table
 137  */
 138 struct mesh_table {
 139         /* Number of buckets will be 2^N */
 140         struct hlist_head *hash_buckets;
 141         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 142         unsigned int hash_mask;         /* (2^size_order) - 1 */
 143         __u32 hash_rnd;                 /* Used for hash generation */
 144         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 145         void (*free_node) (struct hlist_node *p, bool free_leafs);
 146         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 147         int size_order;
 148         int mean_chain_len;
 149         struct hlist_head *known_gates;
 150         spinlock_t gates_lock;
 151
 152         struct rcu_head rcu_head;
 153 };
 154
 155 /* Recent multicast cache */
 156 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 157 #define RMC_BUCKETS             256
 158 #define RMC_QUEUE_MAX_LEN       4
 159 #define RMC_TIMEOUT             (3 * HZ)
 160
 161 /**
 162  * struct rmc_entry - entry in the Recent Multicast Cache
 163  *
 164  * @seqnum: mesh sequence number of the frame
 165  * @exp_time: expiration time of the entry, in jiffies
 166  * @sa: source address of the frame
 167  *
 168  * The Recent Multicast Cache keeps track of the latest multicast frames that
 169  * have been received by a mesh interface and discards received multicast frames
 170  * that are found in the cache.
 171  */
 172 struct rmc_entry {
 173         struct list_head list;
 174         u32 seqnum;
 175         unsigned long exp_time;
 176         u8 sa[ETH_ALEN];
 177 };
 178
 179 struct mesh_rmc {
 180         struct rmc_entry bucket[RMC_BUCKETS];
 181         u32 idx_mask;
 182 };
 183
 184 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 185 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 186
 187 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 188
 189 #define MESH_PATH_EXPIRE (600 * HZ)
 190
 191 /* Default maximum number of plinks per interface */
 192 #define MESH_MAX_PLINKS         256
 193
 194 /* Maximum number of paths per interface */
 195 #define MESH_MAX_MPATHS         1024
 196
 197 /* Public interfaces */
 198 /* Various */
 199 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 200                                   const u8 *da, const u8 *sa);
 201 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 202                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 203                 char *addr6);
 204 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 205                 struct ieee80211_sub_if_data *sdata);
 206 bool mesh_matches_local(struct ieee802_11_elems *ie,
 207                 struct ieee80211_sub_if_data *sdata);
 208 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 209 void mesh_mgmt_ies_add(struct sk_buff *skb,
 210                 struct ieee80211_sub_if_data *sdata);
 211 int mesh_add_meshconf_ie(struct sk_buff *skb,
 212                          struct ieee80211_sub_if_data *sdata);
 213 int mesh_add_meshid_ie(struct sk_buff *skb,
 214                        struct ieee80211_sub_if_data *sdata);
 215 int mesh_add_rsn_ie(struct sk_buff *skb,
 216                     struct ieee80211_sub_if_data *sdata);
 217 int mesh_add_vendor_ies(struct sk_buff *skb,
 218                         struct ieee80211_sub_if_data *sdata);
 219 int mesh_add_ds_params_ie(struct sk_buff *skb,
 220                           struct ieee80211_sub_if_data *sdata);
 221 int mesh_add_ht_cap_ie(struct sk_buff *skb,
 222                        struct ieee80211_sub_if_data *sdata);
 223 int mesh_add_ht_info_ie(struct sk_buff *skb,
 224                         struct ieee80211_sub_if_data *sdata);
 225 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 226 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 227 void ieee80211s_init(void);
 228 void ieee80211s_update_metric(struct ieee80211_local *local,
 229                 struct sta_info *stainfo, struct sk_buff *skb);
 230 void ieee80211s_stop(void);
 231 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 232 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 233 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 234 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 235
 236 /* Mesh paths */
 237 int mesh_nexthop_lookup(struct sk_buff *skb,
 238                 struct ieee80211_sub_if_data *sdata);
 239 int mesh_nexthop_resolve(struct sk_buff *skb,
 240                          struct ieee80211_sub_if_data *sdata);
 241 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 242 struct mesh_path *mesh_path_lookup(u8 *dst,
 243                 struct ieee80211_sub_if_data *sdata);
 244 struct mesh_path *mpp_path_lookup(u8 *dst,
 245                                   struct ieee80211_sub_if_data *sdata);
 246 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 247 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 248                 struct ieee80211_sub_if_data *sdata);
 249 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 250 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 251 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 252                 struct ieee80211_mgmt *mgmt, size_t len);
 253 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 254
 255 int mesh_path_add_gate(struct mesh_path *mpath);
 256 int mesh_path_send_to_gates(struct mesh_path *mpath);
 257 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 258 /* Mesh plinks */
 259 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 260                 struct ieee80211_sub_if_data *sdata,
 261                 struct ieee802_11_elems *ie);
 262 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 263 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 264 void mesh_plink_broken(struct sta_info *sta);
 265 void mesh_plink_deactivate(struct sta_info *sta);
 266 int mesh_plink_open(struct sta_info *sta);
 267 void mesh_plink_block(struct sta_info *sta);
 268 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 269                          struct ieee80211_mgmt *mgmt, size_t len,
 270                          struct ieee80211_rx_status *rx_status);
 271
 272 /* Private interfaces */
 273 /* Mesh tables */
 274 void mesh_mpath_table_grow(void);
 275 void mesh_mpp_table_grow(void);
 276 /* Mesh paths */
 277 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 278                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 279 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 280 void mesh_path_flush_pending(struct mesh_path *mpath);
 281 void mesh_path_tx_pending(struct mesh_path *mpath);
 282 int mesh_pathtbl_init(void);
 283 void mesh_pathtbl_unregister(void);
 284 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 285 void mesh_path_timer(unsigned long data);
 286 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 287 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 288 void mesh_path_discard_frame(struct sk_buff *skb,
 289                 struct ieee80211_sub_if_data *sdata);
 290 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 291 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 292 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 293
 294 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 295 extern int mesh_paths_generation;
 296
 297 #ifdef CONFIG_MAC80211_MESH
 298 extern int mesh_allocated;
 299
 300 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 301 {
 302         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 303                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 304 }
 305
 306 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 307 {
 308         return (min_t(long, mesh_plink_free_count(sdata),
 309                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 310 }
 311
 312 static inline void mesh_path_activate(struct mesh_path *mpath)
 313 {
 314         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 315 }
 316
 317 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 318 {
 319         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 320 }
 321
 322 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 323
 324 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 325 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 326 void mesh_plink_quiesce(struct sta_info *sta);
 327 void mesh_plink_restart(struct sta_info *sta);
 328 #else
 329 #define mesh_allocated  0
 330 static inline void
 331 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 332 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 333 {}
 334 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 335 {}
 336 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 337 static inline void mesh_plink_restart(struct sta_info *sta) {}
 338 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 339 { return false; }
 340 #endif
 341
 342 #endif /* IEEE80211S_H */