/* NET/ROM support definitions */

#define NR3HLEN		15		/* length of a NET/ROM level 3 hdr */
#define NR3NODESIG	0xff		/* signature for nodes broadcast */
#define NR3NODEHL	7		/* nodes bc header length */
#define NR4HLEN		5		/* length of a NET/ROM level 4 hdr */
#define NR4ILEN		(256-NR3HLEN-NR4HLEN) /* max length of info at level 4 */

#define NRNUMCHAINS	53		/* number of chains in the */
					/* neighbor and route hash tables */
#define NRRTDESTLEN	21		/* length of destination entry in */
					/* broadcast */
#define NRDESTPERPACK	11		/* maximum number of destinations per */
					/* nodes packet */

#define NR4NUMCIRC	20		/* maximum number of circuits */

#if (!defined(MSDOS) || defined(LARGEDATA))
#define NETROM4		1		/* level-4 only for lots of mem */
#endif

/* Internal representation of NET/ROM network layer header */
struct nr3hdr {
	struct ax25_addr source;	/* callsign of origin node */
	struct ax25_addr dest;		/* callsign of destination node */
	unsigned ttl;			/* time-to-live */
};

/* Internal representation of NET/ROM routing broadcast destination */
/* entry */
struct nr3dest {
	struct ax25_addr dest;		/* destination callsign */
	char alias[7];			/* ident, upper case ASCII, blank-filled */

	struct ax25_addr neighbor;	/* best-quality neighbor */
	unsigned quality;		/* quality of route for this neighbor */
};

/* Internal representation of NET/ROM transport layer header */
struct nr4hdr {
	unsigned opcode;		/* transport layer opcode */
#define	 NR4OMASK	0x0f		/* mask to isolate opcode */
#define	 NR4MORE	0x20		/* more follows flag */
#define	 NR4NAK		0x40		/* NAK flag */
#define	 NR4CHOKE	0x80		/* CHOKE flag */
#define	 NR4CREFUSE	0x80		/* connect request refused flag */

#define	 NR4PID		0		/* network protocol extension */
#define	 NR4CONRQ	1		/* connect request */
#define	 NR4CONACK	2		/* connect acknowledge */
#define	 NR4DISRQ	3		/* disconnect request */
#define	 NR4DISACK	4		/* disconnect acknowledge */
#define	 NR4INFO	5		/* information */
#define	 NR4INFACK	6		/* information acknowledge */
	unsigned char family,proto;	/* network extension family/protocol */
	struct ckt {
		unsigned char index;	/* circuit index */
		unsigned char id;	/* circuit id */
	} your,my;
	unsigned char txseq;		/* transmit sequence number */
	unsigned char rxseq;		/* receive sequence number */
	unsigned window;		/* proposed/accepted window size */
	struct ax25_addr suser;		/* callsign of originating user */
	struct ax25_addr snode;		/* callsign of originating node */
};

/* NET/ROM interface info. linked to interface struct */
struct nriface {
	char alias[7];			/* alias for this interface's node */
					/* broadcasts */
	unsigned char quality;		/* NET/ROM link quality estimate */
	char uplink;			/* uplink allowed here? */
};

#define NULLNRIFACE	(struct nriface *)0

/* NET/ROM neighbor table structure */
struct nrnbr_tab {
	struct nrnbr_tab *next;		/* doubly linked list pointers */
	struct nrnbr_tab *prev;
	char call[AXALEN*3];		/* call of neighbor + 2 digis max */
	struct interface *interface;	/* interface of neighbor's port */
	unsigned refcnt;		/* how many routes for this neighbor? */
	unsigned failcnt;		/* failure count on AX.25 link */
};

#define NULLNTAB	(struct nrnbr_tab *)0


/* A list of these structures is provided for each route table */
/* entry.  They bind a destination to a neighbor node.	If the */
/* list of bindings becomes empty, the route table entry is    */
/* automatically deleted.				       */

struct nr_bind {
	struct nr_bind *next;		/* doubly linked list */
	struct nr_bind *prev;
	unsigned char quality;		/* quality estimate */
	unsigned char obsocnt;		/* obsolescence count */
	unsigned char flags;
#define NRB_PERMANENT	0x01		/* entry never times out */
	struct nrnbr_tab *via;		/* route goes via this neighbor */
};

#define NULLNRBIND	(struct nr_bind *)0


/* NET/ROM routing table entry */

struct nrroute_tab {
	struct nrroute_tab *next;	/* doubly linked list pointers */
	struct nrroute_tab *prev;
	struct nrroute_tab *sort;	/* link pointer when sorting */
	char alias[7];			/* alias of node */
	struct ax25_addr call;		/* callsign of node */
	unsigned num_routes;		/* how many routes in bindings list? */
	struct nr_bind *routes;		/* list of neighbors */
};

#define NULLNRRTAB	(struct nrroute_tab *)0


/* description of a NET/ROM level 4 circuit */
struct nr_circ {
	struct ckt my,your;		/* circuit identifiers */
	struct ax25_addr suser;		/* callsign of originating user */
	struct ax25_addr snode;		/* callsign of originating node */
	struct ax25_addr dnode;		/* callsign of destination node */
	unsigned window;		/* proposed/accepted window size */

	int state;			/* connection state */
#define NR4STDISC	0		/* disconnected */
#define NR4STCPEND	1		/* connection pending */
#define NR4STCON	2		/* connected */
#define NR4STDPEND	3		/* disconnect requested locally */

	unsigned char txseq;		/* transmit sequence number */
	unsigned char txack;		/* ack'ed transmit sequence */
	unsigned char rxseq;		/* receive sequence number */

	unsigned char mystate;		/* state to send to other side */
	char r_choked;			/* choke received from remote */
	char s_choked;			/* sent choked myself */

	char d_reason;			/* disconnect reason */
#define NR4REDISC	0		/* disconnected */
#define NR4REFAIL	1		/* failed */
#define NR4REBUSY	2		/* busy (CHOKE) */

	int retries;			/* number of re-tries done */

	struct mbuf *txq;		/* transmit queue */
	struct mbuf *rxasm;		/* receive assembly buffer */
	struct mbuf *rxq;		/* receive queue */

	struct timer trtimer;		/* transport timer */
	struct timer acktimer;		/* ack delay timer */
	struct timer noacttim;		/* no-activity timer */

	void (*r_upcall)();		/* receive upcall */
	void (*t_upcall)();		/* transmit upcall */
	void (*s_upcall)();		/* state change upcall */

	char *user;			/* user pointer */
};

#define NULLNRCIRC	(struct nr_circ *)0

/* description of a NET/ROM level 7 user */

struct nr_user {
	struct nr_user	*next;
	struct nr_user	*prev;
	struct ax25_cb	*ax25_cb[2];	/* AX.25 link control blocks */
	struct nr_circ	*nrcirc[2];	/* NET/ROM level 4 control blocks */
#define NRU_UP		0		/* uplink (connecting user) cb's */
#define NRU_DOWN	1		/* downlink (connected user) cb's */
	struct interface *iface;	/* interface for connects */
	int		errors;		/* command errors made sofar */
};
#define	    NULLNRUSER	(struct nr_user *)0


/* The NET/ROM nodes broadcast filter structure */
struct nrnf_tab {
	struct nrnf_tab *next;		/* doubly linked list */
	struct nrnf_tab *prev;
	struct ax25_addr neighbor;	/* call of neighbor to filter */

	struct interface *interface;	/* filter on this interface */
};

#define NULLNRNFTAB	(struct nrnf_tab *)0


/* The neighbor hash table (hashed on neighbor callsign) */
extern struct nrnbr_tab *nrnbr_tab[NRNUMCHAINS];

/* The routes hash table (hashed on destination callsign) */
extern struct nrroute_tab *nrroute_tab[NRNUMCHAINS];

/* The circuit table (index on circuit index) */
extern struct nr_circ *nr_circ[NR4NUMCIRC];

/* The nodes broadcast filter table */
extern struct nrnf_tab *nrnf_tab[NRNUMCHAINS];

/* filter modes: */
#define NRNF_NOFILTER	0		/* don't filter */
#define NRNF_REJECT	1		/* reject broadcasts from stations in list */
#define NRNF_ACCEPT	2		/* accept broadcasts from stations in list */
#define NRNF_EXCLUSIVE	3		/* same as accept but only traffic from listed */

/* The filter mode */
extern unsigned nr_nfmode;

/* The time-to-live for NET/ROM network layer packets */
extern unsigned nr_ttl;

/* The obsolescence count initializer */
extern unsigned obso_init;

/* The threshhold at which routes becoming obsolete are not broadcast */
extern unsigned obso_minbc;

/* The quality threshhold below which routes in a broadcast will */
/* be ignored */
extern unsigned nr_autofloor;

/* The maximum fail count on AX.25 links to neighbors.	      */
/* When this is exceeded, all routes via this neighbor are    */
/* dropped from the table. (except the permanent routes)      */
extern unsigned nr_maxfail;

/* The maximum number of packets on an AX.25 queue to a	      */
/* neighbor.  If exceeded, an alternative route is selected   */
/* or the packet is dropped.				      */
extern unsigned nr_maxqueue;

/* The maximum number of routes maintained for a destination. */
/* If the list fills up, only the highest quality routes are  */
/* kept.  This limiting is done to avoid possible over-use of */
/* memory for routing tables in closely spaced NET/ROM networks. */
extern unsigned nr_maxroutes;

/* a indication that nodes without tcp/ip alias should (not) be */
/* included in the nodes list broadcasted by this node */
extern unsigned nr_tcpip;
extern char nr_aliasip[];
#define NRT_NORM	0		/* no special handling */
#define NRT_ILNK	1		/* interlink mode */
#define NRT_NOBR	2		/* don't broadcast */
#define NRT_IGN		3		/* don't even register them */
#define NR_TCPIP	"#TCPIP"	/* the magic alias (by default) */

/* a list of nodes that is not allowed to appear in the nodelist */
extern struct ax25_call *nr_excl[];

/* The netrom pseudo-interface */
extern struct interface *nr_interface;

/* File to send on INFO command from NET/ROM user */
extern char nr_infname[];

#ifdef NETROM4
/* Transport timeout (seconds) */
extern unsigned nr_trtimeout;

/* Transport maximum tries */
extern unsigned nr_trtries;

/* Transport acknowledge delay (seconds) */
extern unsigned nr_trackdelay;

/* Transport busy delay (seconds) */
extern unsigned nr_trbusdelay;

/* Transport requested window size */
extern unsigned nr_trwindow;

/* Congestion control treshold (frames) */
extern unsigned nr_trbacklog;

/* No-activity timeout (seconds) */
extern unsigned nr_noactive;

/* Interface that's to be the "LAP" (default for connects) */
extern struct interface *nr_lap;
#endif

/* Functions */
extern char *htonnrdest();
extern char *nr_fmtcall();
extern char *nr_getroute();
extern int nr4_send();
extern int nr_nfadd();
extern int nr_nfdrop();
extern int nr_rnb_drop();
extern int nr_rt_add();
extern int nr_rt_drop();
extern int ntohnrdest();
extern struct ax25_addr *nr_scall();
extern struct mbuf *htonnr3();
extern struct mbuf *htonnr4();
extern struct mbuf *nr4_recv();
extern struct nr_circ *nr4_conn();
extern struct nrnbr_tab *find_nrnbr();
extern struct nrroute_tab *find_nralias();
extern struct nrroute_tab *find_nrroute();
extern void nruserdump();