1 /* 2 * Copyright (c) 2008 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_DSN_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_DSN_VALID = BIT(2), 42 MESH_PATH_FIXED = BIT(3), 43 MESH_PATH_RESOLVED = BIT(4), 44 }; 45 46 /** 47 * struct mesh_path - mac80211 mesh path structure 48 * 49 * @dst: mesh path destination mac address 50 * @sdata: mesh subif 51 * @next_hop: mesh neighbor to which frames for this destination will be 52 * forwarded 53 * @timer: mesh path discovery timer 54 * @frame_queue: pending queue for frames sent to this destination while the 55 * path is unresolved 56 * @dsn: destination sequence number of the destination 57 * @metric: current metric to this destination 58 * @hop_count: hops to destination 59 * @exp_time: in jiffies, when the path will expire or when it expired 60 * @discovery_timeout: timeout (lapse in jiffies) used for the last discovery 61 * retry 62 * @discovery_retries: number of discovery retries 63 * @flags: mesh path flags, as specified on &enum mesh_path_flags 64 * @state_lock: mesh pat state lock 65 * 66 * 67 * The combination of dst and sdata is unique in the mesh path table. Since the 68 * next_hop STA is only protected by RCU as well, deleting the STA must also 69 * remove/substitute the mesh_path structure and wait until that is no longer 70 * reachable before destroying the STA completely. 71 */ 72 struct mesh_path { 73 u8 dst[ETH_ALEN]; 74 u8 mpp[ETH_ALEN]; /* used for MPP or MAP */ 75 struct ieee80211_sub_if_data *sdata; 76 struct sta_info *next_hop; 77 struct timer_list timer; 78 struct sk_buff_head frame_queue; 79 struct rcu_head rcu; 80 u32 dsn; 81 u32 metric; 82 u8 hop_count; 83 unsigned long exp_time; 84 u32 discovery_timeout; 85 u8 discovery_retries; 86 enum mesh_path_flags flags; 87 spinlock_t state_lock; 88 }; 89 90 /** 91 * struct mesh_table 92 * 93 * @hash_buckets: array of hash buckets of the table 94 * @hashwlock: array of locks to protect write operations, one per bucket 95 * @hash_mask: 2^size_order - 1, used to compute hash idx 96 * @hash_rnd: random value used for hash computations 97 * @entries: number of entries in the table 98 * @free_node: function to free nodes of the table 99 * @copy_node: fuction to copy nodes of the table 100 * @size_order: determines size of the table, there will be 2^size_order hash 101 * buckets 102 * @mean_chain_len: maximum average length for the hash buckets' list, if it is 103 * reached, the table will grow 104 */ 105 struct mesh_table { 106 /* Number of buckets will be 2^N */ 107 struct hlist_head *hash_buckets; 108 spinlock_t *hashwlock; /* One per bucket, for add/del */ 109 unsigned int hash_mask; /* (2^size_order) - 1 */ 110 __u32 hash_rnd; /* Used for hash generation */ 111 atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */ 112 void (*free_node) (struct hlist_node *p, bool free_leafs); 113 int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl); 114 int size_order; 115 int mean_chain_len; 116 }; 117 118 /* Recent multicast cache */ 119 /* RMC_BUCKETS must be a power of 2, maximum 256 */ 120 #define RMC_BUCKETS 256 121 #define RMC_QUEUE_MAX_LEN 4 122 #define RMC_TIMEOUT (3 * HZ) 123 124 /** 125 * struct rmc_entry - entry in the Recent Multicast Cache 126 * 127 * @seqnum: mesh sequence number of the frame 128 * @exp_time: expiration time of the entry, in jiffies 129 * @sa: source address of the frame 130 * 131 * The Recent Multicast Cache keeps track of the latest multicast frames that 132 * have been received by a mesh interface and discards received multicast frames 133 * that are found in the cache. 134 */ 135 struct rmc_entry { 136 struct list_head list; 137 u32 seqnum; 138 unsigned long exp_time; 139 u8 sa[ETH_ALEN]; 140 }; 141 142 struct mesh_rmc { 143 struct rmc_entry bucket[RMC_BUCKETS]; 144 u32 idx_mask; 145 }; 146 147 148 /* 149 * MESH_CFG_COMP_LEN Includes: 150 * - Active path selection protocol ID. 151 * - Active path selection metric ID. 152 * - Congestion control mode identifier. 153 * - Channel precedence. 154 * Does not include mesh capabilities, which may vary across nodes in the same 155 * mesh 156 */ 157 #define MESH_CFG_CMP_LEN (IEEE80211_MESH_CONFIG_LEN - 2) 158 159 /* Default values, timeouts in ms */ 160 #define MESH_TTL 5 161 #define MESH_MAX_RETR 3 162 #define MESH_RET_T 100 163 #define MESH_CONF_T 100 164 #define MESH_HOLD_T 100 165 166 #define MESH_PATH_TIMEOUT 5000 167 /* Minimum interval between two consecutive PREQs originated by the same 168 * interface 169 */ 170 #define MESH_PREQ_MIN_INT 10 171 #define MESH_DIAM_TRAVERSAL_TIME 50 172 /* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their 173 * expiration 174 */ 175 #define MESH_PATH_REFRESH_TIME 1000 176 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME) 177 178 #define MESH_MAX_PREQ_RETRIES 4 179 #define MESH_PATH_EXPIRE (600 * HZ) 180 181 /* Default maximum number of established plinks per interface */ 182 #define MESH_MAX_ESTAB_PLINKS 32 183 184 /* Default maximum number of plinks per interface */ 185 #define MESH_MAX_PLINKS 256 186 187 /* Maximum number of paths per interface */ 188 #define MESH_MAX_MPATHS 1024 189 190 /* Pending ANA approval */ 191 #define PLINK_CATEGORY 30 192 #define MESH_PATH_SEL_CATEGORY 32 193 194 /* Public interfaces */ 195 /* Various */ 196 int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr, 197 struct ieee80211_sub_if_data *sdata); 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 void mesh_rmc_free(struct ieee80211_sub_if_data *sdata); 206 int mesh_rmc_init(struct ieee80211_sub_if_data *sdata); 207 void ieee80211s_init(void); 208 void ieee80211s_stop(void); 209 void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata); 210 ieee80211_rx_result 211 ieee80211_mesh_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, 212 struct ieee80211_rx_status *rx_status); 213 void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata); 214 void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata); 215 216 /* Mesh paths */ 217 int mesh_nexthop_lookup(struct sk_buff *skb, 218 struct ieee80211_sub_if_data *sdata); 219 void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata); 220 struct mesh_path *mesh_path_lookup(u8 *dst, 221 struct ieee80211_sub_if_data *sdata); 222 struct mesh_path *mpp_path_lookup(u8 *dst, 223 struct ieee80211_sub_if_data *sdata); 224 int mpp_path_add(u8 *dst, u8 *mpp, struct ieee80211_sub_if_data *sdata); 225 struct mesh_path *mesh_path_lookup_by_idx(int idx, 226 struct ieee80211_sub_if_data *sdata); 227 void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop); 228 void mesh_path_expire(struct ieee80211_sub_if_data *sdata); 229 void mesh_path_flush(struct ieee80211_sub_if_data *sdata); 230 void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata, 231 struct ieee80211_mgmt *mgmt, size_t len); 232 int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata); 233 /* Mesh plinks */ 234 void mesh_neighbour_update(u8 *hw_addr, u32 rates, 235 struct ieee80211_sub_if_data *sdata, bool add); 236 bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie); 237 void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata); 238 void mesh_plink_broken(struct sta_info *sta); 239 void mesh_plink_deactivate(struct sta_info *sta); 240 int mesh_plink_open(struct sta_info *sta); 241 void mesh_plink_block(struct sta_info *sta); 242 void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, 243 struct ieee80211_mgmt *mgmt, size_t len, 244 struct ieee80211_rx_status *rx_status); 245 246 /* Private interfaces */ 247 /* Mesh tables */ 248 struct mesh_table *mesh_table_alloc(int size_order); 249 void mesh_table_free(struct mesh_table *tbl, bool free_leafs); 250 struct mesh_table *mesh_table_grow(struct mesh_table *tbl); 251 u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata, 252 struct mesh_table *tbl); 253 /* Mesh paths */ 254 int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra, 255 struct ieee80211_sub_if_data *sdata); 256 void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta); 257 void mesh_path_flush_pending(struct mesh_path *mpath); 258 void mesh_path_tx_pending(struct mesh_path *mpath); 259 int mesh_pathtbl_init(void); 260 void mesh_pathtbl_unregister(void); 261 int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata); 262 void mesh_path_timer(unsigned long data); 263 void mesh_path_flush_by_nexthop(struct sta_info *sta); 264 void mesh_path_discard_frame(struct sk_buff *skb, 265 struct ieee80211_sub_if_data *sdata); 266 void mesh_path_quiesce(struct ieee80211_sub_if_data *sdata); 267 void mesh_path_restart(struct ieee80211_sub_if_data *sdata); 268 269 #ifdef CONFIG_MAC80211_MESH 270 extern int mesh_allocated; 271 272 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata) 273 { 274 return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks - 275 atomic_read(&sdata->u.mesh.mshstats.estab_plinks); 276 } 277 278 static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata) 279 { 280 return (min_t(long, mesh_plink_free_count(sdata), 281 MESH_MAX_PLINKS - sdata->local->num_sta)) > 0; 282 } 283 284 static inline void mesh_path_activate(struct mesh_path *mpath) 285 { 286 mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED; 287 } 288 289 #define for_each_mesh_entry(x, p, node, i) \ 290 for (i = 0; i <= x->hash_mask; i++) \ 291 hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list) 292 293 void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local); 294 295 void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata); 296 void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata); 297 void mesh_plink_quiesce(struct sta_info *sta); 298 void mesh_plink_restart(struct sta_info *sta); 299 #else 300 #define mesh_allocated 0 301 static inline void 302 ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local) {} 303 static inline void ieee80211_mesh_quiesce(struct ieee80211_sub_if_data *sdata) 304 {} 305 static inline void ieee80211_mesh_restart(struct ieee80211_sub_if_data *sdata) 306 {} 307 static inline void mesh_plink_quiesce(struct sta_info *sta) {} 308 static inline void mesh_plink_restart(struct sta_info *sta) {} 309 #endif 310 311 #endif /* IEEE80211S_H */ 312