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/*
* Copyright (c) 2008 open80211s Ltd.
* Authors: Luis Carlos Cobo <luisca@cozybit.com>
* Javier Cardona <javier@cozybit.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef IEEE80211S_H
#define IEEE80211S_H
#include <linux/types.h>
#include <linux/jhash.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
/* Data structures */
/**
* enum mesh_path_flags - mac80211 mesh path flags
*
*
*
* @MESH_PATH_ACTIVE: the mesh path is can be used for forwarding
* @MESH_PATH_RESOLVED: the discovery process is running for this mesh path
* @MESH_PATH_DSN_VALID: the mesh path contains a valid destination sequence
* number
* @MESH_PATH_FIXED: the mesh path has been manually set and should not be
* modified
* @MESH_PATH_RESOLVED: the mesh path can has been resolved
*
* MESH_PATH_RESOLVED and MESH_PATH_DELETE are used by the mesh path timer to
* decide when to stop or cancel the mesh path discovery.
*/
enum mesh_path_flags {
MESH_PATH_ACTIVE = BIT(0),
MESH_PATH_RESOLVING = BIT(1),
MESH_PATH_DSN_VALID = BIT(2),
MESH_PATH_FIXED = BIT(3),
MESH_PATH_RESOLVED = BIT(4),
};
/**
* struct mesh_path - mac80211 mesh path structure
*
* @dst: mesh path destination mac address
* @sdata: mesh subif
* @next_hop: mesh neighbor to which frames for this destination will be
* forwarded
* @timer: mesh path discovery timer
* @frame_queue: pending queue for frames sent to this destination while the
* path is unresolved
* @dsn: destination sequence number of the destination
* @metric: current metric to this destination
* @hop_count: hops to destination
* @exp_time: in jiffies, when the path will expire or when it expired
* @discovery_timeout: timeout (lapse in jiffies) used for the last discovery
* retry
* @discovery_retries: number of discovery retries
* @flags: mesh path flags, as specified on &enum mesh_path_flags
* @state_lock: mesh pat state lock
*
*
* The combination of dst and sdata is unique in the mesh path table. Since the
* next_hop STA is only protected by RCU as well, deleting the STA must also
* remove/substitute the mesh_path structure and wait until that is no longer
* reachable before destroying the STA completely.
*/
struct mesh_path {
u8 dst[ETH_ALEN];
struct ieee80211_sub_if_data *sdata;
struct sta_info *next_hop;
struct timer_list timer;
struct sk_buff_head frame_queue;
struct rcu_head rcu;
u32 dsn;
u32 metric;
u8 hop_count;
unsigned long exp_time;
u32 discovery_timeout;
u8 discovery_retries;
enum mesh_path_flags flags;
spinlock_t state_lock;
};
/**
* struct mesh_table
*
* @hash_buckets: array of hash buckets of the table
* @hashwlock: array of locks to protect write operations, one per bucket
* @hash_mask: 2^size_order - 1, used to compute hash idx
* @hash_rnd: random value used for hash computations
* @entries: number of entries in the table
* @free_node: function to free nodes of the table
* @copy_node: fuction to copy nodes of the table
* @size_order: determines size of the table, there will be 2^size_order hash
* buckets
* @mean_chain_len: maximum average length for the hash buckets' list, if it is
* reached, the table will grow
*/
struct mesh_table {
/* Number of buckets will be 2^N */
struct hlist_head *hash_buckets;
spinlock_t *hashwlock; /* One per bucket, for add/del */
unsigned int hash_mask; /* (2^size_order) - 1 */
__u32 hash_rnd; /* Used for hash generation */
atomic_t entries; /* Up to MAX_MESH_NEIGHBOURS */
void (*free_node) (struct hlist_node *p, bool free_leafs);
int (*copy_node) (struct hlist_node *p, struct mesh_table *newtbl);
int size_order;
int mean_chain_len;
};
/* Recent multicast cache */
/* RMC_BUCKETS must be a power of 2, maximum 256 */
#define RMC_BUCKETS 256
#define RMC_QUEUE_MAX_LEN 4
#define RMC_TIMEOUT (3 * HZ)
/**
* struct rmc_entry - entry in the Recent Multicast Cache
*
* @seqnum: mesh sequence number of the frame
* @exp_time: expiration time of the entry, in jiffies
* @sa: source address of the frame
*
* The Recent Multicast Cache keeps track of the latest multicast frames that
* have been received by a mesh interface and discards received multicast frames
* that are found in the cache.
*/
struct rmc_entry {
struct list_head list;
u32 seqnum;
unsigned long exp_time;
u8 sa[ETH_ALEN];
};
struct mesh_rmc {
struct rmc_entry bucket[RMC_BUCKETS];
u32 idx_mask;
};
/* Mesh IEs constants */
#define MESH_CFG_LEN 19
/*
* MESH_CFG_COMP_LEN Includes:
* - Active path selection protocol ID.
* - Active path selection metric ID.
* - Congestion control mode identifier.
* - Channel precedence.
* Does not include mesh capabilities, which may vary across nodes in the same
* mesh
*/
#define MESH_CFG_CMP_LEN 17
/* Default values, timeouts in ms */
#define MESH_TTL 5
#define MESH_MAX_RETR 3
#define MESH_RET_T 100
#define MESH_CONF_T 100
#define MESH_HOLD_T 100
#define MESH_PATH_TIMEOUT 5000
/* Minimum interval between two consecutive PREQs originated by the same
* interface
*/
#define MESH_PREQ_MIN_INT 10
#define MESH_DIAM_TRAVERSAL_TIME 50
/* Paths will be refreshed if they are closer than PATH_REFRESH_TIME to their
* expiration
*/
#define MESH_PATH_REFRESH_TIME 1000
#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
#define MESH_MAX_PREQ_RETRIES 4
#define MESH_PATH_EXPIRE (600 * HZ)
/* Default maximum number of established plinks per interface */
#define MESH_MAX_ESTAB_PLINKS 32
/* Default maximum number of plinks per interface */
#define MESH_MAX_PLINKS 256
/* Maximum number of paths per interface */
#define MESH_MAX_MPATHS 1024
/* Pending ANA approval */
#define PLINK_CATEGORY 30
#define MESH_PATH_SEL_CATEGORY 32
/* Mesh Header Flags */
#define IEEE80211S_FLAGS_AE 0x3
/* Public interfaces */
/* Various */
u8 mesh_id_hash(u8 *mesh_id, int mesh_id_len);
int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
int ieee80211_new_mesh_header(struct ieee80211s_hdr *meshhdr,
struct ieee80211_sub_if_data *sdata);
int mesh_rmc_check(u8 *addr, struct ieee80211s_hdr *mesh_hdr,
struct ieee80211_sub_if_data *sdata);
bool mesh_matches_local(struct ieee802_11_elems *ie,
struct ieee80211_sub_if_data *sdata);
void mesh_ids_set_default(struct ieee80211_if_sta *sta);
void mesh_mgmt_ies_add(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata);
void mesh_rmc_free(struct ieee80211_sub_if_data *sdata);
int mesh_rmc_init(struct ieee80211_sub_if_data *sdata);
void ieee80211s_init(void);
void ieee80211s_stop(void);
void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);
/* Mesh paths */
int mesh_nexthop_lookup(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata);
void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);
struct mesh_path *mesh_path_lookup(u8 *dst,
struct ieee80211_sub_if_data *sdata);
struct mesh_path *mesh_path_lookup_by_idx(int idx,
struct ieee80211_sub_if_data *sdata);
void mesh_path_fix_nexthop(struct mesh_path *mpath, struct sta_info *next_hop);
void mesh_path_expire(struct ieee80211_sub_if_data *sdata);
void mesh_path_flush(struct ieee80211_sub_if_data *sdata);
void mesh_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len);
int mesh_path_add(u8 *dst, struct ieee80211_sub_if_data *sdata);
/* Mesh plinks */
void mesh_neighbour_update(u8 *hw_addr, u64 rates,
struct ieee80211_sub_if_data *sdata, bool add);
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
void mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
void mesh_plink_broken(struct sta_info *sta);
void mesh_plink_deactivate(struct sta_info *sta);
int mesh_plink_open(struct sta_info *sta);
int mesh_plink_close(struct sta_info *sta);
void mesh_plink_block(struct sta_info *sta);
void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata,
struct ieee80211_mgmt *mgmt, size_t len,
struct ieee80211_rx_status *rx_status);
/* Private interfaces */
/* Mesh tables */
struct mesh_table *mesh_table_alloc(int size_order);
void mesh_table_free(struct mesh_table *tbl, bool free_leafs);
struct mesh_table *mesh_table_grow(struct mesh_table *tbl);
u32 mesh_table_hash(u8 *addr, struct ieee80211_sub_if_data *sdata,
struct mesh_table *tbl);
/* Mesh paths */
int mesh_path_error_tx(u8 *dest, __le32 dest_dsn, u8 *ra,
struct ieee80211_sub_if_data *sdata);
void mesh_path_assign_nexthop(struct mesh_path *mpath, struct sta_info *sta);
void mesh_path_flush_pending(struct mesh_path *mpath);
void mesh_path_tx_pending(struct mesh_path *mpath);
int mesh_pathtbl_init(void);
void mesh_pathtbl_unregister(void);
int mesh_path_del(u8 *addr, struct ieee80211_sub_if_data *sdata);
void mesh_path_timer(unsigned long data);
void mesh_path_flush_by_nexthop(struct sta_info *sta);
void mesh_path_discard_frame(struct sk_buff *skb,
struct ieee80211_sub_if_data *sdata);
#ifdef CONFIG_MAC80211_MESH
extern int mesh_allocated;
static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
{
return sdata->u.sta.mshcfg.dot11MeshMaxPeerLinks -
atomic_read(&sdata->u.sta.mshstats.estab_plinks);
}
static inline bool mesh_plink_availables(struct ieee80211_sub_if_data *sdata)
{
return (min_t(long, mesh_plink_free_count(sdata),
MESH_MAX_PLINKS - sdata->local->num_sta)) > 0;
}
static inline void mesh_path_activate(struct mesh_path *mpath)
{
mpath->flags |= MESH_PATH_ACTIVE | MESH_PATH_RESOLVED;
}
#define for_each_mesh_entry(x, p, node, i) \
for (i = 0; i <= x->hash_mask; i++) \
hlist_for_each_entry_rcu(node, p, &x->hash_buckets[i], list)
#else
#define mesh_allocated 0
#endif
#endif /* IEEE80211S_H */
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