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
  84  *
  85  *
  86  * The combination of dst and sdata is unique in the mesh path table. Since the
  87  * next_hop STA is only protected by RCU as well, deleting the STA must also
  88  * remove/substitute the mesh_path structure and wait until that is no longer
  89  * reachable before destroying the STA completely.
  90  */
  91 struct mesh_path {
  92         u8 dst[ETH_ALEN];
  93         u8 mpp[ETH_ALEN];       /* used for MPP or MAP */
  94         struct ieee80211_sub_if_data *sdata;
  95         struct sta_info *next_hop;
  96         struct timer_list timer;
  97         struct sk_buff_head frame_queue;
  98         struct rcu_head rcu;
  99         u32 sn;
 100         u32 metric;
 101         u8 hop_count;
 102         unsigned long exp_time;
 103         u32 discovery_timeout;
 104         u8 discovery_retries;
 105         enum mesh_path_flags flags;
 106         spinlock_t state_lock;
 107 };
 108
 109 /**
 110  * struct mesh_table
 111  *
 112  * @hash_buckets: array of hash buckets of the table
 113  * @hashwlock: array of locks to protect write operations, one per bucket
 114  * @hash_mask: 2^size_order - 1, used to compute hash idx
 115  * @hash_rnd: random value used for hash computations
 116  * @entries: number of entries in the table
 117  * @free_node: function to free nodes of the table
 118  * @copy_node: function to copy nodes of the table
 119  * @size_order: determines size of the table, there will be 2^size_order hash
 120  *      buckets
 121  * @mean_chain_len: maximum average length for the hash buckets' list, if it is
 122  *      reached, the table will grow
 123  */
 124 struct mesh_table {
 125         /* Number of buckets will be 2^N */
 126         struct hlist_head *hash_buckets;
 127         spinlock_t *hashwlock;          /* One per bucket, for add/del */
 128         unsigned int hash_mask;         /* (2^size_order) - 1 */
 129         __u32 hash_rnd;                 /* Used for hash generation */
 130         atomic_t entries;               /* Up to MAX_MESH_NEIGHBOURS */
 131         void (*free_node) (struct hlist_node *p, bool free_leafs);
 132         int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
 133         int size_order;
 134         int mean_chain_len;
 135 };
 136
 137 /* Recent multicast cache */
 138 /* RMC_BUCKETS must be a power of 2, maximum 256 */
 139 #define RMC_BUCKETS             256
 140 #define RMC_QUEUE_MAX_LEN       4
 141 #define RMC_TIMEOUT             (3 * HZ)
 142
 143 /**
 144  * struct rmc_entry - entry in the Recent Multicast Cache
 145  *
 146  * @seqnum: mesh sequence number of the frame
 147  * @exp_time: expiration time of the entry, in jiffies
 148  * @sa: source address of the frame
 149  *
 150  * The Recent Multicast Cache keeps track of the latest multicast frames that
 151  * have been received by a mesh interface and discards received multicast frames
 152  * that are found in the cache.
 153  */
 154 struct rmc_entry {
 155         struct list_head list;
 156         u32 seqnum;
 157         unsigned long exp_time;
 158         u8 sa[ETH_ALEN];
 159 };
 160
 161 struct mesh_rmc {
 162         struct rmc_entry bucket[RMC_BUCKETS];
 163         u32 idx_mask;
 164 };
 165
 166
 167 #define MESH_DEFAULT_BEACON_INTERVAL            1000    /* in 1024 us units */
 168
 169 #define MESH_PATH_EXPIRE (600 * HZ)
 170
 171 /* Default maximum number of plinks per interface */
 172 #define MESH_MAX_PLINKS         256
 173
 174 /* Maximum number of paths per interface */
 175 #define MESH_MAX_MPATHS         1024
 176
 177 /* Pending ANA approval */
 178 #define MESH_PATH_SEL_ACTION    0
 179
 180 /* PERR reason codes */
 181 #define PEER_RCODE_UNSPECIFIED  11
 182 #define PERR_RCODE_NO_ROUTE     12
 183 #define PERR_RCODE_DEST_UNREACH 13
 184
 185 /* Public interfaces */
 186 /* Various */
 187 int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,
 188                                   const u8 *da, const u8 *sa);
 189 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
 190                 struct ieee80211_sub_if_data *sdata, char *addr4or5,
 191                 char *addr6);
 192 int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
 193                 struct ieee80211_sub_if_data *sdata);
 194 bool mesh_matches_local(struct ieee802_11_elems *ie,
 195                 struct ieee80211_sub_if_data *sdata);
 196 void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);
 197 void mesh_mgmt_ies_add(struct sk_buff *skb,
 198                 struct ieee80211_sub_if_data *sdata);
 199 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
 200 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
 201 void ieee80211s_init(void);
 202 void ieee80211s_update_metric(struct ieee80211_local *local,
 203                 struct sta_info *stainfo, struct sk_buff *skb);
 204 void ieee80211s_stop(void);
 205 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
 206 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);
 207 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);
 208 void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);
 209
 210 /* Mesh paths */
 211 int mesh_nexthop_lookup(struct sk_buff *skb,
 212                 struct ieee80211_sub_if_data *sdata);
 213 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
 214 struct mesh_path *mesh_path_lookup(u8 *dst,
 215                 struct ieee80211_sub_if_data *sdata);
 216 struct mesh_path *mpp_path_lookup(u8 *dst,
 217                                   struct ieee80211_sub_if_data *sdata);
 218 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata);
 219 struct mesh_path *mesh_path_lookup_by_idx(int idx,
 220                 struct ieee80211_sub_if_data *sdata);
 221 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
 222 void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
 223 void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
 224 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
 225                 struct ieee80211_mgmt *mgmt, size_t len);
 226 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
 227 /* Mesh plinks */
 228 void mesh_neighbour_update(u8 *hw_addr, u32 rates,
 229                 struct ieee80211_sub_if_data *sdata, bool add);
 230 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
 231 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
 232 void mesh_plink_broken(struct sta_info *sta);
 233 void mesh_plink_deactivate(struct sta_info *sta);
 234 int mesh_plink_open(struct sta_info *sta);
 235 void mesh_plink_block(struct sta_info *sta);
 236 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
 237                          struct ieee80211_mgmt *mgmt, size_t len,
 238                          struct ieee80211_rx_status *rx_status);
 239
 240 /* Private interfaces */
 241 /* Mesh tables */
 242 struct mesh_table *mesh_table_alloc(int size_order);
 243 void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
 244 void mesh_mpath_table_grow(void);
 245 void mesh_mpp_table_grow(void);
 246 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
 247                 struct mesh_table *tbl);
 248 /* Mesh paths */
 249 int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode,
 250                        const u8 *ra, struct ieee80211_sub_if_data *sdata);
 251 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
 252 void mesh_path_flush_pending(struct mesh_path *mpath);
 253 void mesh_path_tx_pending(struct mesh_path *mpath);
 254 int mesh_pathtbl_init(void);
 255 void mesh_pathtbl_unregister(void);
 256 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
 257 void mesh_path_timer(unsigned long data);
 258 void mesh_path_flush_by_nexthop(struct sta_info *sta);
 259 void mesh_path_discard_frame(struct sk_buff *skb,
 260                 struct ieee80211_sub_if_data *sdata);
 261 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata);
 262 void mesh_path_restart(struct ieee80211_sub_if_data *sdata);
 263 void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);
 264
 265 extern int mesh_paths_generation;
 266
 267 #ifdef CONFIG_MAC80211_MESH
 268 extern int mesh_allocated;
 269
 270 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
 271 {
 272         return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -
 273                atomic_read(&sdata->u.mesh.mshstats.estab_plinks);
 274 }
 275
 276 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
 277 {
 278         return (min_t(long, mesh_plink_free_count(sdata),
 279                    MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
 280 }
 281
 282 static inline void mesh_path_activate(struct mesh_path *mpath)
 283 {
 284         mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
 285 }
 286
 287 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 288 {
 289         return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
 290 }
 291
 292 #define for_each_mesh_entry(x, p, node, i) \
 293         for (i = 0; i <= x->hash_mask; i++) \
 294                 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
 295
 296 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local);
 297
 298 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata);
 299 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata);
 300 void mesh_plink_quiesce(struct sta_info *sta);
 301 void mesh_plink_restart(struct sta_info *sta);
 302 #else
 303 #define mesh_allocated  0
 304 static inline void
 305 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {}
 306 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata)
 307 {}
 308 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata)
 309 {}
 310 static inline void mesh_plink_quiesce(struct sta_info *sta) {}
 311 static inline void mesh_plink_restart(struct sta_info *sta) {}
 312 static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
 313 { return false; }
 314 #endif
 315
 316 #endif /* IEEE80211S_H */