/* SPDX-License-Identifier: GPL-2.0-only */

  /*

   * Copyright (c) 2008, 2009 open80211s Ltd.

   * Authors:    Luis Carlos Cobo <luisca@cozybit.com>
   *             Javier Cardona <javier@cozybit.com>

   */
  
  #ifndef IEEE80211S_H
  #define IEEE80211S_H

  #include <linux/types.h>

  #include <linux/jhash.h>

  #include "ieee80211_i.h"

  
  /* Data structures */
  
  /**
   * enum mesh_path_flags - mac80211 mesh path flags
   *

   * @MESH_PATH_ACTIVE: the mesh path can be used for forwarding
   * @MESH_PATH_RESOLVING: the discovery process is running for this mesh path

   * @MESH_PATH_SN_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_REQ_QUEUED: there is an unsent path request for this destination

   *	already queued up, waiting for the discovery process to start.

   * @MESH_PATH_DELETED: the mesh path has been deleted and should no longer
   *	be used

   *

   * MESH_PATH_RESOLVED is 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_SN_VALID =	BIT(2),

  	MESH_PATH_FIXED	=	BIT(3),
  	MESH_PATH_RESOLVED =	BIT(4),

  	MESH_PATH_REQ_QUEUED =	BIT(5),

  	MESH_PATH_DELETED =	BIT(6),

  };
  
  /**

   * enum mesh_deferred_task_flags - mac80211 mesh deferred tasks
   *
   *
   *
   * @MESH_WORK_HOUSEKEEPING: run the periodic mesh housekeeping tasks

   * @MESH_WORK_ROOT: the mesh root station needs to send a frame

   * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
   * mesh nodes

   * @MESH_WORK_MBSS_CHANGED: rebuild beacon and notify driver of BSS changes

   */
  enum mesh_deferred_task_flags {
  	MESH_WORK_HOUSEKEEPING,

  	MESH_WORK_ROOT,

  	MESH_WORK_DRIFT_ADJUST,

  	MESH_WORK_MBSS_CHANGED,

  };
  
  /**

   * struct mesh_path - mac80211 mesh path structure
   *
   * @dst: mesh path destination mac address

   * @mpp: mesh proxy mac address
   * @rhash: rhashtable list pointer

   * @walk_list: linked list containing all mesh_path objects.

   * @gate_list: list pointer for known gates list

   * @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

   * @rcu: rcu head for freeing mesh path

   * @sn: target sequence number

   * @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 path state lock used to protect changes to the
   * mpath itself.  No need to take this lock when adding or removing
   * an mpath to a hash bucket on a path table.

   * @rann_snd_addr: the RANN sender address

   * @rann_metric: the aggregated path metric towards the root node

   * @last_preq_to_root: Timestamp of last PREQ sent to root

   * @is_root: the destination station of this path is a root node

   * @is_gate: the destination station of this path is a mesh gate

   * @path_change_count: the number of path changes to destination

   *
   *

   * The dst address is unique in the mesh path table. Since the mesh_path is
   * protected by RCU, deleting the next_hop STA must 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];

  	u8 mpp[ETH_ALEN];	/* used for MPP or MAP */

  	struct rhash_head rhash;

  	struct hlist_node walk_list;

  	struct hlist_node gate_list;

  	struct ieee80211_sub_if_data *sdata;

  	struct sta_info __rcu *next_hop;

  	struct timer_list timer;
  	struct sk_buff_head frame_queue;
  	struct rcu_head rcu;

  	u32 sn;

  	u32 metric;
  	u8 hop_count;
  	unsigned long exp_time;
  	u32 discovery_timeout;
  	u8 discovery_retries;
  	enum mesh_path_flags flags;
  	spinlock_t state_lock;

  	u8 rann_snd_addr[ETH_ALEN];

  	u32 rann_metric;

  	unsigned long last_preq_to_root;

  	bool is_root;

  	bool is_gate;

  	u32 path_change_count;

  };
  
  /**
   * struct mesh_table
   *

   * @known_gates: list of known mesh gates and their mpaths by the station. The
   * gate's mpath may or may not be resolved and active.

   * @gates_lock: protects updates to known_gates
   * @rhead: the rhashtable containing struct mesh_paths, keyed by dest addr

   * @walk_head: linked list containging all mesh_path objects
   * @walk_lock: lock protecting walk_head

   * @entries: number of entries in the table

   */
  struct mesh_table {

  	struct hlist_head known_gates;

  	spinlock_t gates_lock;

  	struct rhashtable rhead;

  	struct hlist_head walk_head;
  	spinlock_t walk_lock;

  	atomic_t entries;		/* Up to MAX_MESH_NEIGHBOURS */

  };
  
  /* 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

   * @list: hashtable list pointer

   *
   * 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 hlist_node list;

  	unsigned long exp_time;

  	u32 seqnum;

  	u8 sa[ETH_ALEN];
  };
  
  struct mesh_rmc {

  	struct hlist_head bucket[RMC_BUCKETS];

  	u32 idx_mask;

  };

  #define IEEE80211_MESH_HOUSEKEEPING_INTERVAL (60 * HZ)

  #define MESH_PATH_EXPIRE (600 * HZ)

  /* Default maximum number of plinks per interface */
  #define MESH_MAX_PLINKS		256
  
  /* Maximum number of paths per interface */
  #define MESH_MAX_MPATHS		1024

  /* Number of frames buffered per destination for unresolved destinations */
  #define MESH_FRAME_QUEUE_LEN	10

  /* Public interfaces */
  /* Various */

  int ieee80211_fill_mesh_addresses(struct ieee80211_hdr *hdr, __le16 *fc,

  				  const u8 *da, const u8 *sa);

  unsigned int ieee80211_new_mesh_header(struct ieee80211_sub_if_data *sdata,
  				       struct ieee80211s_hdr *meshhdr,
  				       const char *addr4or5, const char *addr6);

  int mesh_rmc_check(struct ieee80211_sub_if_data *sdata,
  		   const u8 *addr, struct ieee80211s_hdr *mesh_hdr);

  bool mesh_matches_local(struct ieee80211_sub_if_data *sdata,
  			struct ieee802_11_elems *ie);

  void mesh_ids_set_default(struct ieee80211_if_mesh *mesh);

  int mesh_add_meshconf_ie(struct ieee80211_sub_if_data *sdata,
  			 struct sk_buff *skb);
  int mesh_add_meshid_ie(struct ieee80211_sub_if_data *sdata,
  		       struct sk_buff *skb);
  int mesh_add_rsn_ie(struct ieee80211_sub_if_data *sdata,
  		    struct sk_buff *skb);
  int mesh_add_vendor_ies(struct ieee80211_sub_if_data *sdata,
  			struct sk_buff *skb);
  int mesh_add_ht_cap_ie(struct ieee80211_sub_if_data *sdata,
  		       struct sk_buff *skb);
  int mesh_add_ht_oper_ie(struct ieee80211_sub_if_data *sdata,
  			struct sk_buff *skb);

  int mesh_add_vht_cap_ie(struct ieee80211_sub_if_data *sdata,
  			struct sk_buff *skb);
  int mesh_add_vht_oper_ie(struct ieee80211_sub_if_data *sdata,
  			 struct sk_buff *skb);

  int mesh_add_he_cap_ie(struct ieee80211_sub_if_data *sdata,
  		       struct sk_buff *skb, u8 ie_len);
  int mesh_add_he_oper_ie(struct ieee80211_sub_if_data *sdata,
  			struct sk_buff *skb);

  int mesh_add_he_6ghz_cap_ie(struct ieee80211_sub_if_data *sdata,
  			    struct sk_buff *skb);

  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_update_metric(struct ieee80211_local *local,

  			      struct sta_info *sta,
  			      struct ieee80211_tx_status *st);

  void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata);

  void ieee80211_mesh_teardown_sdata(struct ieee80211_sub_if_data *sdata);

  int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata);

  void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata);

  void ieee80211_mesh_root_setup(struct ieee80211_if_mesh *ifmsh);

  const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method);

  /* wrapper for ieee80211_bss_info_change_notify() */
  void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,
  				       u32 changed);

  /* mesh power save */

  u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata);
  u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
  				   enum nl80211_mesh_power_mode pm);

  void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
  				   struct sta_info *sta,
  				   struct ieee80211_hdr *hdr);
  void ieee80211_mps_sta_status_update(struct sta_info *sta);
  void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
  				    struct ieee80211_hdr *hdr);
  void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
  				    bool tx, bool acked);
  void ieee80211_mps_frame_release(struct sta_info *sta,
  				 struct ieee802_11_elems *elems);

  /* Mesh paths */

  int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata,
  			struct sk_buff *skb);
  int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata,
  			 struct sk_buff *skb);

  void mesh_path_start_discovery(struct ieee80211_sub_if_data *sdata);

  struct mesh_path *mesh_path_lookup(struct ieee80211_sub_if_data *sdata,
  				   const u8 *dst);
  struct mesh_path *mpp_path_lookup(struct ieee80211_sub_if_data *sdata,
  				  const u8 *dst);
  int mpp_path_add(struct ieee80211_sub_if_data *sdata,
  		 const u8 *dst, const u8 *mpp);
  struct mesh_path *
  mesh_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);

  struct mesh_path *
  mpp_path_lookup_by_idx(struct ieee80211_sub_if_data *sdata, int idx);

  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_rx_path_sel_frame(struct ieee80211_sub_if_data *sdata,

  			    struct ieee80211_mgmt *mgmt, size_t len);

  struct mesh_path *
  mesh_path_add(struct ieee80211_sub_if_data *sdata, const u8 *dst);

  
  int mesh_path_add_gate(struct mesh_path *mpath);
  int mesh_path_send_to_gates(struct mesh_path *mpath);
  int mesh_gate_num(struct ieee80211_sub_if_data *sdata);

  u32 airtime_link_metric_get(struct ieee80211_local *local,
  			    struct sta_info *sta);

  /* Mesh plinks */

  void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,

  			   u8 *hw_addr, struct ieee802_11_elems *ie,
  			   struct ieee80211_rx_status *rx_status);

  bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);

  u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);

  void mesh_plink_timer(struct timer_list *t);

  void mesh_plink_broken(struct sta_info *sta);

  u32 mesh_plink_deactivate(struct sta_info *sta);

  u32 mesh_plink_open(struct sta_info *sta);
  u32 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);

  void mesh_sta_cleanup(struct sta_info *sta);

  
  /* Private interfaces */

  /* Mesh paths */

  int mesh_path_error_tx(struct ieee80211_sub_if_data *sdata,

  		       u8 ttl, const u8 *target, u32 target_sn,
  		       u16 target_rcode, const u8 *ra);

  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(struct ieee80211_sub_if_data *sdata);
  void mesh_pathtbl_unregister(struct ieee80211_sub_if_data *sdata);

  int mesh_path_del(struct ieee80211_sub_if_data *sdata, const u8 *addr);

  void mesh_path_timer(struct timer_list *t);

  void mesh_path_flush_by_nexthop(struct sta_info *sta);

  void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata,
  			     struct sk_buff *skb);

  void mesh_path_tx_root_frame(struct ieee80211_sub_if_data *sdata);

  bool mesh_action_is_path_sel(struct ieee80211_mgmt *mgmt);

  #ifdef CONFIG_MAC80211_MESH

  static inline
  u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
  {
  	atomic_inc(&sdata->u.mesh.estab_plinks);

  	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;

  }
  
  static inline
  u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
  {
  	atomic_dec(&sdata->u.mesh.estab_plinks);

  	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;

  }

  static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)
  {

  	return sdata->u.mesh.mshcfg.dot11MeshMaxPeerLinks -

  	       atomic_read(&sdata->u.mesh.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;
  }

  static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
  {
  	return sdata->u.mesh.mesh_pp_id == IEEE80211_PATH_PROTOCOL_HWMP;
  }

  void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata);

  void mesh_sync_adjust_tsf(struct ieee80211_sub_if_data *sdata);

  void ieee80211s_stop(void);

  #else

  static inline bool mesh_path_sel_is_hwmp(struct ieee80211_sub_if_data *sdata)
  { return false; }

  static inline void mesh_path_flush_by_iface(struct ieee80211_sub_if_data *sdata)
  {}

  static inline void ieee80211s_stop(void) {}

  #endif

  #endif /* IEEE80211S_H */