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  */
  38 enum 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  */
  58 enum 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 used to protect changes to the
  84  * mpath itself.  No need to take this lock when adding or removing
  85  * an mpath to a hash bucket on a path table.
  86  * @is_gate: the destination station of this path is a mesh gate
  87  *
  88  *
  89  * The combination of dst and sdata is unique in the mesh path table. Since the
  90  * next_hop STA is only protected by RCU as well, deleting the STA must also
  91  * remove/substitute the mesh_path structure and wait until that is no longer
  92  * reachable before destroying the STA completely.
  93  */
  94 struct mesh_path {
  95         u8 dst[ETH_ALEN];
  96         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  97         struct ieee80211_sub_if_data *sdata;
  98         struct sta_info __rcu *next_hop;
  99         struct timer_list timer;
 100         struct sk_buff_head frame_queue;
 101         struct rcu_head rcu;
 102         u32 sn;
 103         u32 metric;
 104         u8 hop_count;
 105         unsigned long exp_time;
 106         u32 discovery_timeout;
 107         u8 discovery_retries;
 108         enum mesh_path_flags flags;
 109         spinlock_t state_lock;
 110         bool is_gate;
 111 };
 112
 113 /**
 114  * struct mesh_table
 115  *
 116  * @hash_buckets: array of hash buckets of the table
 117  * @hashwlock: array of locks to protect write operations, one per bucket
 118  * @hash_mask: 2^size_order - 1, used to compute hash idx
 119  * @hash_rnd: random value used for hash computations
 120  * @entries: number of entries in the table
 121  * @free_node: function to free nodes of the table
 122  * @copy_node: function to copy nodes of the table
 123  * @size_order: determines size of the table, there will be 2^size_order hash
 124  *      buckets
 125  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 126  *      reached, the table will grow
 127  * @known_gates: list of known mesh gates and their mpaths by the station. The
 128  * gate's mpath may or may not be resolved and active.
 129  *
 130  * rcu_head: RCU head to free the table
 131  */
 132 struct mesh_table {
 133         /* Number of buckets will be 2^N */
 134         struct hlist_head *hash_buckets;
 135         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 136         unsigned int hash_mask;         /* (2^size_order) - 1 */
 137         __u32 hash_rnd;                 /* Used for hash generation */
 138         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 139         void (*free_node) (struct hlist_node *p, bool free_leafs);
 140         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 141         int size_order;
 142         int mean_chain_len;
 143         struct hlist_head *known_gates;
 144         spinlock_t gates_lock;
 145
 146         struct rcu_head rcu_head;
 147 };
 148
 149 /* Recent multicast cache */
 150 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 151 #define RMC_BUCKETS             256
 152 #define RMC_QUEUE_MAX_LEN       4
 153 #define RMC_TIMEOUT             (3 * HZ)
 154
 155 /**
 156  * struct rmc_entry - entry in the Recent Multicast Cache
 157  *
 158  * @seqnum: mesh sequence number of the frame
 159  * @exp_time: expiration time of the entry, in jiffies
 160  * @sa: source address of the frame
 161  *
 162  * The Recent Multicast Cache keeps track of the latest multicast frames that
 163  * have been received by a mesh interface and discards received multicast frames
 164  * that are found in the cache.
 165  */
 166 struct rmc_entry {
 167         struct list_head list;
 168         u32 seqnum;
 169         unsigned long exp_time;
 170         u8 sa[ETH_ALEN];
 171 };
 172
 173 struct mesh_rmc {
 174         struct rmc_entry bucket[RMC_BUCKETS];
 175         u32 idx_mask;
 176 };
 177
 178 #define IEEE80211_MESH_PEER_INACTIVITY_LIMIT (1800 * HZ)
 179 #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)
 180
 181 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 182
 183 #define MESH_PATH_EXPIRE (600 * HZ)
 184
 185 /* Default maximum number of plinks per interface */
 186 #define MESH_MAX_PLINKS         256
 187
 188 /* Maximum number of paths per interface */
 189 #define MESH_MAX_MPATHS         1024
 190
 191 /* Public interfaces */
 192 /* Various */
 193 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 194                                   const u8 *da, const u8 *sa);
 195 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 196                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 197                 char *addr6);
 198 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 199                 struct ieee80211_sub_if_data *sdata);
 200 bool mesh_matches_local(struct ieee802_11_elems *ie,
 201                 struct ieee80211_sub_if_data *sdata);
 202 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 203 void mesh_mgmt_ies_add(struct sk_buff *skb,
 204                 struct ieee80211_sub_if_data *sdata);
 205 int mesh_add_meshconf_ie(struct sk_buff *skb,
 206                          struct ieee80211_sub_if_data *sdata);
 207 int mesh_add_meshid_ie(struct sk_buff *skb,
 208                        struct ieee80211_sub_if_data *sdata);
 209 int mesh_add_rsn_ie(struct sk_buff *skb,
 210                     struct ieee80211_sub_if_data *sdata);
 211 int mesh_add_vendor_ies(struct sk_buff *skb,
 212                         struct ieee80211_sub_if_data *sdata);
 213 int mesh_add_srates_ie(struct sk_buff *skb,
 214                        struct ieee80211_sub_if_data *sdata);
 215 int mesh_add_ext_srates_ie(struct sk_buff *skb,
 216                            struct ieee80211_sub_if_data *sdata);
 217 int mesh_add_ds_params_ie(struct sk_buff *skb,
 218                           struct ieee80211_sub_if_data *sdata);
 219 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 220 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 221 void ieee80211s_init(void);
 222 void ieee80211s_update_metric(struct ieee80211_local *local,
 223                 struct sta_info *stainfo, struct sk_buff *skb);
 224 void ieee80211s_stop(void);
 225 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 226 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 227 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 228 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 229
 230 /* Mesh paths */
 231 int mesh_nexthop_lookup(struct sk_buff *skb,
 232                 struct ieee80211_sub_if_data *sdata);
 233 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 234 struct mesh_path *mesh_path_lookup(u8 *dst,
 235                 struct ieee80211_sub_if_data *sdata);
 236 struct mesh_path *mpp_path_lookup(u8 *dst,
 237                                   struct ieee80211_sub_if_data *sdata);
 238 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 239 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 240                 struct ieee80211_sub_if_data *sdata);
 241 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 242 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 243 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 244                 struct ieee80211_mgmt *mgmt, size_t len);
 245 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 246
 247 int mesh_path_add_gate(struct mesh_path *mpath);
 248 int mesh_path_send_to_gates(struct mesh_path *mpath);
 249 int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
 250 /* Mesh plinks */
 251 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 252                 struct ieee80211_sub_if_data *sdata,
 253                 struct ieee802_11_elems *ie);
 254 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 255 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 256 void mesh_plink_broken(struct sta_info *sta);
 257 void mesh_plink_deactivate(struct sta_info *sta);
 258 int mesh_plink_open(struct sta_info *sta);
 259 void mesh_plink_block(struct sta_info *sta);
 260 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 261                          struct ieee80211_mgmt *mgmt, size_t len,
 262                          struct ieee80211_rx_status *rx_status);
 263
 264 /* Private interfaces */
 265 /* Mesh tables */
 266 void mesh_mpath_table_grow(void);
 267 void mesh_mpp_table_grow(void);
 268 /* Mesh paths */
 269 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 270                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 271 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 272 void mesh_path_flush_pending(struct mesh_path *mpath);
 273 void mesh_path_tx_pending(struct mesh_path *mpath);
 274 int mesh_pathtbl_init(void);
 275 void mesh_pathtbl_unregister(void);
 276 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 277 void mesh_path_timer(unsigned long data);
 278 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 279 void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);
 280 void mesh_path_discard_frame(struct sk_buff *skb,
 281                 struct ieee80211_sub_if_data *sdata);
 282 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 283 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 284 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 285
 286 bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);
 287 extern int mesh_paths_generation;
 288
 289 #ifdef CONFIG_MAC80211_MESH
 290 extern int mesh_allocated;
 291
 292 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 293 {
 294         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 295                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 296 }
 297
 298 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 299 {
 300         return (min_t(long, mesh_plink_free_count(sdata),
 301                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 302 }
 303
 304 static inline void mesh_path_activate(struct mesh_path *mpath)
 305 {
 306         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 307 }
 308
 309 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 310 {
 311         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 312 }
 313
 314 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 315
 316 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 317 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 318 void mesh_plink_quiesce(struct sta_info *sta);
 319 void mesh_plink_restart(struct sta_info *sta);
 320 #else
 321 #define mesh_allocated  0
 322 static inline void
 323 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 324 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 325 {}
 326 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 327 {}
 328 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 329 static inline void mesh_plink_restart(struct sta_info *sta) {}
 330 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 331 { return false; }
 332 #endif
 333
 334 #endif /* IEEE80211S_H */