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

  /*
   *	Declarations of X.25 Packet Layer type objects.
   *
   * 	History
   *	nov/17/96	Jonathan Naylor	  Initial version.		
   *	mar/20/00	Daniela Squassoni Disabling/enabling of facilities 
   *					  negotiation.
   */
  
  #ifndef _X25_H
  #define _X25_H 
  #include <linux/x25.h>

  #include <linux/slab.h>

  #include <linux/refcount.h>

  #include <net/sock.h>
  
  #define	X25_ADDR_LEN			16
  
  #define	X25_MAX_L2_LEN			18	/* 802.2 LLC */
  
  #define	X25_STD_MIN_LEN			3
  #define	X25_EXT_MIN_LEN			4
  
  #define	X25_GFI_SEQ_MASK		0x30
  #define	X25_GFI_STDSEQ			0x10
  #define	X25_GFI_EXTSEQ			0x20
  
  #define	X25_Q_BIT			0x80
  #define	X25_D_BIT			0x40
  #define	X25_STD_M_BIT			0x10
  #define	X25_EXT_M_BIT			0x01
  
  #define	X25_CALL_REQUEST		0x0B
  #define	X25_CALL_ACCEPTED		0x0F
  #define	X25_CLEAR_REQUEST		0x13
  #define	X25_CLEAR_CONFIRMATION		0x17
  #define	X25_DATA			0x00
  #define	X25_INTERRUPT			0x23
  #define	X25_INTERRUPT_CONFIRMATION	0x27
  #define	X25_RR				0x01
  #define	X25_RNR				0x05
  #define	X25_REJ				0x09
  #define	X25_RESET_REQUEST		0x1B
  #define	X25_RESET_CONFIRMATION		0x1F
  #define	X25_REGISTRATION_REQUEST	0xF3
  #define	X25_REGISTRATION_CONFIRMATION	0xF7
  #define	X25_RESTART_REQUEST		0xFB
  #define	X25_RESTART_CONFIRMATION	0xFF
  #define	X25_DIAGNOSTIC			0xF1
  #define	X25_ILLEGAL			0xFD
  
  /* Define the various conditions that may exist */
  
  #define	X25_COND_ACK_PENDING	0x01
  #define	X25_COND_OWN_RX_BUSY	0x02
  #define	X25_COND_PEER_RX_BUSY	0x04
  
  /* Define Link State constants. */
  enum {
  	X25_STATE_0,		/* Ready */
  	X25_STATE_1,		/* Awaiting Call Accepted */
  	X25_STATE_2,		/* Awaiting Clear Confirmation */
  	X25_STATE_3,		/* Data Transfer */
  	X25_STATE_4		/* Awaiting Reset Confirmation */
  };
  
  enum {
  	X25_LINK_STATE_0,
  	X25_LINK_STATE_1,
  	X25_LINK_STATE_2,
  	X25_LINK_STATE_3
  };
  
  #define X25_DEFAULT_T20		(180 * HZ)		/* Default T20 value */
  #define X25_DEFAULT_T21		(200 * HZ)		/* Default T21 value */
  #define X25_DEFAULT_T22		(180 * HZ)		/* Default T22 value */
  #define	X25_DEFAULT_T23		(180 * HZ)		/* Default T23 value */
  #define	X25_DEFAULT_T2		(3   * HZ)		/* Default ack holdback value */
  
  #define	X25_DEFAULT_WINDOW_SIZE	2			/* Default Window Size	*/
  #define	X25_DEFAULT_PACKET_SIZE	X25_PS128		/* Default Packet Size */
  #define	X25_DEFAULT_THROUGHPUT	0x0A			/* Deafult Throughput */
  #define	X25_DEFAULT_REVERSE	0x00			/* Default Reverse Charging */
  
  #define X25_SMODULUS 		8
  #define	X25_EMODULUS		128
  
  /*
   *	X.25 Facilities constants.
   */
  
  #define	X25_FAC_CLASS_MASK	0xC0
  
  #define	X25_FAC_CLASS_A		0x00
  #define	X25_FAC_CLASS_B		0x40
  #define	X25_FAC_CLASS_C		0x80
  #define	X25_FAC_CLASS_D		0xC0

  #define	X25_FAC_REVERSE		0x01			/* also fast select */

  #define	X25_FAC_THROUGHPUT	0x02
  #define	X25_FAC_PACKET_SIZE	0x42
  #define	X25_FAC_WINDOW_SIZE	0x43

  #define X25_MAX_FAC_LEN 	60

  #define	X25_MAX_CUD_LEN		128

  #define X25_FAC_CALLING_AE 	0xCB
  #define X25_FAC_CALLED_AE 	0xC9
  
  #define X25_MARKER 		0x00
  #define X25_DTE_SERVICES 	0x0F
  #define X25_MAX_AE_LEN 		40			/* Max num of semi-octets in AE - OSI Nw */
  #define X25_MAX_DTE_FACIL_LEN	21			/* Max length of DTE facility params */

  /* Bitset in x25_sock->flags for misc flags */
  #define X25_Q_BIT_FLAG		0

  #define X25_INTERRUPT_FLAG	1

  #define X25_ACCPT_APPRV_FLAG	2

  /**
   *	struct x25_route - x25 routing entry
   *	@node - entry in x25_list_lock
   *	@address - Start of address range
   *	@sigdigits - Number of sig digits
   *	@dev - More than one for MLP
   *	@refcnt - reference counter
   */
  struct x25_route {
  	struct list_head	node;		
  	struct x25_address	address;
  	unsigned int		sigdigits;
  	struct net_device	*dev;

  	refcount_t		refcnt;

  };
  
  struct x25_neigh {
  	struct list_head	node;
  	struct net_device	*dev;
  	unsigned int		state;
  	unsigned int		extended;
  	struct sk_buff_head	queue;
  	unsigned long		t20;
  	struct timer_list	t20timer;
  	unsigned long		global_facil_mask;

  	refcount_t		refcnt;

  };
  
  struct x25_sock {
  	struct sock		sk;
  	struct x25_address	source_addr, dest_addr;
  	struct x25_neigh	*neighbour;

  	unsigned int		lci, cudmatchlength;

  	unsigned char		state, condition;

  	unsigned short		vs, vr, va, vl;
  	unsigned long		t2, t21, t22, t23;
  	unsigned short		fraglen;

  	unsigned long		flags;

  	struct sk_buff_head	ack_queue;
  	struct sk_buff_head	fragment_queue;
  	struct sk_buff_head	interrupt_in_queue;
  	struct sk_buff_head	interrupt_out_queue;
  	struct timer_list	timer;
  	struct x25_causediag	causediag;
  	struct x25_facilities	facilities;

  	struct x25_dte_facilities dte_facilities;

  	struct x25_calluserdata	calluserdata;
  	unsigned long 		vc_facil_mask;	/* inc_call facilities mask */
  };

  struct x25_forward {
  	struct list_head	node;
  	unsigned int		lci;
  	struct net_device	*dev1;
  	struct net_device	*dev2;
  	atomic_t		refcnt;
  };

  static inline struct x25_sock *x25_sk(const struct sock *sk)
  {
  	return (struct x25_sock *)sk;
  }
  
  /* af_x25.c */
  extern int  sysctl_x25_restart_request_timeout;
  extern int  sysctl_x25_call_request_timeout;
  extern int  sysctl_x25_reset_request_timeout;
  extern int  sysctl_x25_clear_request_timeout;
  extern int  sysctl_x25_ack_holdback_timeout;

  extern int  sysctl_x25_forward;

  int x25_parse_address_block(struct sk_buff *skb,
  			    struct x25_address *called_addr,
  			    struct x25_address *calling_addr);
  
  int x25_addr_ntoa(unsigned char *, struct x25_address *, struct x25_address *);
  int x25_addr_aton(unsigned char *, struct x25_address *, struct x25_address *);
  struct sock *x25_find_socket(unsigned int, struct x25_neigh *);
  void x25_destroy_socket_from_timer(struct sock *);
  int x25_rx_call_request(struct sk_buff *, struct x25_neigh *, unsigned int);
  void x25_kill_by_neigh(struct x25_neigh *);

  
  /* x25_dev.c */

  void x25_send_frame(struct sk_buff *, struct x25_neigh *);
  int x25_lapb_receive_frame(struct sk_buff *, struct net_device *,
  			   struct packet_type *, struct net_device *);
  void x25_establish_link(struct x25_neigh *);
  void x25_terminate_link(struct x25_neigh *);

  
  /* x25_facilities.c */

  int x25_parse_facilities(struct sk_buff *, struct x25_facilities *,
  			 struct x25_dte_facilities *, unsigned long *);
  int x25_create_facilities(unsigned char *, struct x25_facilities *,
  			  struct x25_dte_facilities *, unsigned long);
  int x25_negotiate_facilities(struct sk_buff *, struct sock *,
  			     struct x25_facilities *,
  			     struct x25_dte_facilities *);
  void x25_limit_facilities(struct x25_facilities *, struct x25_neigh *);

  /* x25_forward.c */

  void x25_clear_forward_by_lci(unsigned int lci);
  void x25_clear_forward_by_dev(struct net_device *);
  int x25_forward_data(int, struct x25_neigh *, struct sk_buff *);
  int x25_forward_call(struct x25_address *, struct x25_neigh *, struct sk_buff *,
  		     int);

  /* x25_in.c */

  int x25_process_rx_frame(struct sock *, struct sk_buff *);
  int x25_backlog_rcv(struct sock *, struct sk_buff *);

  
  /* x25_link.c */

  void x25_link_control(struct sk_buff *, struct x25_neigh *, unsigned short);
  void x25_link_device_up(struct net_device *);
  void x25_link_device_down(struct net_device *);
  void x25_link_established(struct x25_neigh *);
  void x25_link_terminated(struct x25_neigh *);
  void x25_transmit_clear_request(struct x25_neigh *, unsigned int,
  				unsigned char);
  void x25_transmit_link(struct sk_buff *, struct x25_neigh *);
  int x25_subscr_ioctl(unsigned int, void __user *);
  struct x25_neigh *x25_get_neigh(struct net_device *);
  void x25_link_free(void);

  
  /* x25_neigh.c */
  static __inline__ void x25_neigh_hold(struct x25_neigh *nb)
  {

  	refcount_inc(&nb->refcnt);

  }
  
  static __inline__ void x25_neigh_put(struct x25_neigh *nb)
  {

  	if (refcount_dec_and_test(&nb->refcnt))

  		kfree(nb);
  }
  
  /* x25_out.c */

  int x25_output(struct sock *, struct sk_buff *);
  void x25_kick(struct sock *);
  void x25_enquiry_response(struct sock *);

  
  /* x25_route.c */

  struct x25_route *x25_get_route(struct x25_address *addr);
  struct net_device *x25_dev_get(char *);
  void x25_route_device_down(struct net_device *dev);
  int x25_route_ioctl(unsigned int, void __user *);
  void x25_route_free(void);

  
  static __inline__ void x25_route_hold(struct x25_route *rt)
  {

  	refcount_inc(&rt->refcnt);

  }
  
  static __inline__ void x25_route_put(struct x25_route *rt)
  {

  	if (refcount_dec_and_test(&rt->refcnt))

  		kfree(rt);
  }
  
  /* x25_subr.c */

  void x25_clear_queues(struct sock *);
  void x25_frames_acked(struct sock *, unsigned short);
  void x25_requeue_frames(struct sock *);
  int x25_validate_nr(struct sock *, unsigned short);
  void x25_write_internal(struct sock *, int);
  int x25_decode(struct sock *, struct sk_buff *, int *, int *, int *, int *,
  	       int *);
  void x25_disconnect(struct sock *, int, unsigned char, unsigned char);

  
  /* x25_timer.c */

  void x25_init_timers(struct sock *sk);
  void x25_start_heartbeat(struct sock *);
  void x25_start_t2timer(struct sock *);
  void x25_start_t21timer(struct sock *);
  void x25_start_t22timer(struct sock *);
  void x25_start_t23timer(struct sock *);
  void x25_stop_heartbeat(struct sock *);
  void x25_stop_timer(struct sock *);
  unsigned long x25_display_timer(struct sock *);
  void x25_check_rbuf(struct sock *);

  
  /* sysctl_net_x25.c */

  #ifdef CONFIG_SYSCTL

  int x25_register_sysctl(void);

  void x25_unregister_sysctl(void);

  #else

  static inline int x25_register_sysctl(void) { return 0; };

  static inline void x25_unregister_sysctl(void) {};
  #endif /* CONFIG_SYSCTL */

  struct x25_skb_cb {

  	unsigned int flags;

  };
  #define X25_SKB_CB(s) ((struct x25_skb_cb *) ((s)->cb))
  
  extern struct hlist_head x25_list;
  extern rwlock_t x25_list_lock;
  extern struct list_head x25_route_list;
  extern rwlock_t x25_route_list_lock;

  extern struct list_head x25_forward_list;
  extern rwlock_t x25_forward_list_lock;

  extern struct list_head x25_neigh_list;
  extern rwlock_t x25_neigh_list_lock;

  int x25_proc_init(void);
  void x25_proc_exit(void);

  #endif