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  * @MESH_PATH_REQ_QUEUED: there is an unsent path request for this destination
  35  * already queued up, waiting for the discovery process to start.
  36  *
  37  * MESH_PATH_RESOLVED is used by the mesh path timer to
  38  * decide when to stop or cancel the mesh path discovery.
  39  */
  40 enum mesh_path_flags {
  41         MESH_PATH_ACTIVE =      BIT(0),
  42         MESH_PATH_RESOLVING =   BIT(1),
  43         MESH_PATH_SN_VALID =    BIT(2),
  44         MESH_PATH_FIXED =       BIT(3),
  45         MESH_PATH_RESOLVED =    BIT(4),
  46         MESH_PATH_REQ_QUEUED =  BIT(5),
  47 };
  48
  49 /**
  50  * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
  51  *
  52  *
  53  *
  54  * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks
  55  * @MESH_WORK_GROW_MPATH_TABLE: the mesh path table is full and needs
  56  * to grow.
  57  * @MESH_WORK_GROW_MPP_TABLE: the mesh portals table is full and needs to
  58  * grow
  59  * @MESH_WORK_ROOT: the mesh root station needs to send a frame
  60  */
  61 enum mesh_deferred_task_flags {
  62         MESH_WORK_HOUSEKEEPING,
  63         MESH_WORK_GROW_MPATH_TABLE,
  64         MESH_WORK_GROW_MPP_TABLE,
  65         MESH_WORK_ROOT,
  66 };
  67
  68 /**
  69  * struct mesh_path - mac80211 mesh path structure
  70  *
  71  * @dst: mesh path destination mac address
  72  * @sdata: mesh subif
  73  * @next_hop: mesh neighbor to which frames for this destination will be
  74  *      forwarded
  75  * @timer: mesh path discovery timer
  76  * @frame_queue: pending queue for frames sent to this destination while the
  77  *      path is unresolved
  78  * @sn: target sequence number
  79  * @metric: current metric to this destination
  80  * @hop_count: hops to destination
  81  * @exp_time: in jiffies, when the path will expire or when it expired
  82  * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
  83  *      retry
  84  * @discovery_retries: number of discovery retries
  85  * @flags: mesh path flags, as specified on &enum mesh_path_flags
  86  * @state_lock: mesh path state lock used to protect changes to the
  87  * mpath itself.  No need to take this lock when adding or removing
  88  * an mpath to a hash bucket on a path table.
  89  * @is_gate: the destination station of this path is a mesh gate
  90  *
  91  *
  92  * The combination of dst and sdata is unique in the mesh path table. Since the
  93  * next_hop STA is only protected by RCU as well, deleting the STA must also
  94  * remove/substitute the mesh_path structure and wait until that is no longer
  95  * reachable before destroying the STA completely.
  96  */
  97 struct mesh_path {
  98         u8 dst[ETH_ALEN];
  99         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
 100         struct ieee80211_sub_if_data *sdata;
 101         struct sta_info __rcu *next_hop;
 102         struct timer_list timer;
 103         struct sk_buff_head frame_queue;
 104         struct rcu_head rcu;
 105         u32 sn;
 106         u32 metric;
 107         u8 hop_count;
 108         unsigned long exp_time;
 109         u32 discovery_timeout;
 110         u8 discovery_retries;
 111         enum mesh_path_flags flags;
 112         spinlock_t state_lock;
 113         bool is_gate;
 114 };
 115
 116 /**
 117  * struct mesh_table
 118  *
 119  * @hash_buckets: array of hash buckets of the table
 120  * @hashwlock: array of locks to protect write operations, one per bucket
 121  * @hash_mask: 2^size_order - 1, used to compute hash idx
 122  * @hash_rnd: random value used for hash computations
 123  * @entries: number of entries in the table
 124  * @free_node: function to free nodes of the table
 125  * @copy_node: function to copy nodes of the table
 126  * @size_order: determines size of the table, there will be 2^size_order hash
 127  *      buckets
 128  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 129  *      reached, the table will grow
 130  * @known_gates: list of known mesh gates and their mpaths by the station. The
 131  * gate's mpath may or may not be resolved and active.
 132  *
 133  * rcu_head: RCU head to free the table
 134  */
 135 struct mesh_table {
 136         /* Number of buckets will be 2^N */
 137         struct hlist_head *hash_buckets;
 138         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 139         unsigned int hash_mask;         /* (2^size_order) - 1 */
 140         __u32 hash_rnd;                 /* Used for hash generation */
 141         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 142         void (*free_node) (struct hlist_node *p, bool free_leafs);
 143         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 144         int size_order;
 145         int mean_chain_len;
 146         struct hlist_head *known_gates;
 147         spinlock_t gates_lock;
 148
 149         struct rcu_head rcu_head;
 150 };
 151
 152 /* Recent multicast cache */
 153 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 154 #define RMC_BUCKETS             256
 155 #define RMC_QUEUE_MAX_LEN       4
 156 #define RMC_TIMEOUT             (3 * HZ)
 157
 158 /**
 159  * struct rmc_entry - entry in the Recent Multicast Cache
 160  *
 161  * @seqnum: mesh sequence number of the frame
 162  * @exp_time: expiration time of the entry, in jiffies
 163  * @sa: source address of the frame
 164  *
 165  * The Recent Multicast Cache keeps track of the latest multicast frames that
 166  * have been received by a mesh interface and discards received multicast frames
 167  * that are found in the cache.
 168  */
 169 struct rmc_entry {
 170         struct list_head list;
 171         u32 seqnum;
 172         unsigned long exp_time;
 173         u8 sa[ETH_ALEN];
 174 };
 175
 176 struct mesh_rmc {
 177         struct rmc_entry bucket[RMC_BUCKETS];
 178         u32 idx_mask;
 179 };
 180
 181 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 182 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 183
 184 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 185
 186 #define MESH_PATH_EXPIRE (600 * HZ)
 187
 188 /* Default maximum number of plinks per interface */
 189 #define MESH_MAX_PLINKS         256
 190
 191 /* Maximum number of paths per interface */
 192 #define MESH_MAX_MPATHS         1024
 193
 194 /* Public interfaces */
 195 /* Various */
 196 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 197                                   const u8 *da, const u8 *sa);
 198 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 199                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 200                 char *addr6);
 201 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 202                 struct ieee80211_sub_if_data *sdata);
 203 bool mesh_matches_local(struct ieee802_11_elems *ie,
 204                 struct ieee80211_sub_if_data *sdata);
 205 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 206 void mesh_mgmt_ies_add(struct sk_buff *skb,
 207                 struct ieee80211_sub_if_data *sdata);
 208 int mesh_add_meshconf_ie(struct sk_buff *skb,
 209                          struct ieee80211_sub_if_data *sdata);
 210 int mesh_add_meshid_ie(struct sk_buff *skb,
 211                        struct ieee80211_sub_if_data *sdata);
 212 int mesh_add_rsn_ie(struct sk_buff *skb,
 213                     struct ieee80211_sub_if_data *sdata);
 214 int mesh_add_vendor_ies(struct sk_buff *skb,
 215                         struct ieee80211_sub_if_data *sdata);
 216 int mesh_add_ds_params_ie(struct sk_buff *skb,
 217                           struct ieee80211_sub_if_data *sdata);
 218 int mesh_add_ht_cap_ie(struct sk_buff *skb,
 219                        struct ieee80211_sub_if_data *sdata);
 220 int mesh_add_ht_info_ie(struct sk_buff *skb,
 221                         struct ieee80211_sub_if_data *sdata);
 222 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 223 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 224 void ieee80211s_init(void);
 225 void ieee80211s_update_metric(struct ieee80211_local *local,
 226                 struct sta_info *stainfo, struct sk_buff *skb);
 227 void ieee80211s_stop(void);
 228 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 229 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 230 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 231 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 232
 233 /* Mesh paths */
 234 int mesh_nexthop_lookup(struct sk_buff *skb,
 235                 struct ieee80211_sub_if_data *sdata);
 236 int mesh_nexthop_resolve(struct sk_buff *skb,
 237                          struct ieee80211_sub_if_data *sdata);
 238 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 239 struct mesh_path *mesh_path_lookup(u8 *dst,
 240                 struct ieee80211_sub_if_data *sdata);
 241 struct mesh_path *mpp_path_lookup(u8 *dst,
 242                                   struct ieee80211_sub_if_data *sdata);
 243 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 244 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 245                 struct ieee80211_sub_if_data *sdata);
 246 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 247 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 248 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 249                 struct ieee80211_mgmt *mgmt, size_t len);
 250 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 251
 252 int mesh_path_add_gate(struct mesh_path *mpath);
 253 int mesh_path_send_to_gates(struct mesh_path *mpath);
 254 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 255 /* Mesh plinks */
 256 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 257                 struct ieee80211_sub_if_data *sdata,
 258                 struct ieee802_11_elems *ie);
 259 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 260 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 261 void mesh_plink_broken(struct sta_info *sta);
 262 void mesh_plink_deactivate(struct sta_info *sta);
 263 int mesh_plink_open(struct sta_info *sta);
 264 void mesh_plink_block(struct sta_info *sta);
 265 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 266                          struct ieee80211_mgmt *mgmt, size_t len,
 267                          struct ieee80211_rx_status *rx_status);
 268
 269 /* Private interfaces */
 270 /* Mesh tables */
 271 void mesh_mpath_table_grow(void);
 272 void mesh_mpp_table_grow(void);
 273 /* Mesh paths */
 274 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 275                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 276 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 277 void mesh_path_flush_pending(struct mesh_path *mpath);
 278 void mesh_path_tx_pending(struct mesh_path *mpath);
 279 int mesh_pathtbl_init(void);
 280 void mesh_pathtbl_unregister(void);
 281 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 282 void mesh_path_timer(unsigned long data);
 283 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 284 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 285 void mesh_path_discard_frame(struct sk_buff *skb,
 286                 struct ieee80211_sub_if_data *sdata);
 287 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 288 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 289 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 290
 291 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 292 extern int mesh_paths_generation;
 293
 294 #ifdef CONFIG_MAC80211_MESH
 295 extern int mesh_allocated;
 296
 297 static 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
 303 static 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
 309 static inline void mesh_path_activate(struct mesh_path *mpath)
 310 {
 311         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 312 }
 313
 314 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 315 {
 316         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 317 }
 318
 319 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 320
 321 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 322 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 323 void mesh_plink_quiesce(struct sta_info *sta);
 324 void mesh_plink_restart(struct sta_info *sta);
 325 #else
 326 #define mesh_allocated  0
 327 static inline void
 328 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 329 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 330 {}
 331 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 332 {}
 333 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 334 static inline void mesh_plink_restart(struct sta_info *sta) {}
 335 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 336 { return false; }
 337 #endif
 338
 339 #endif /* IEEE80211S_H */