/*	@(#)udp_tlivar.h 1.4 91/03/11 SMI	*/

/*
 * Copyright (c) 1988 by Sun Microsystems, Inc.
 */

#ifndef	_UDP_TLIVAR_
#define	_UDP_TLIVAR_

/*
 * Data structure definitions for the streams interface
 * to the socket-based UDP implementation - basically the
 * same as tcp_tlivar.h.
 */


/*
 * Socket Information block contains the special socket wakeup
 * hooks. When a block of tt_sockinfo is allocated, the wupalt.wup_arg
 * points to the beginning of tt_sockinfo.
 */

struct tt_sockinfo {
	struct	wupalt	ts_sowakeup;	/* special sock wakeup hook */
	long		ts_flags;	/* see below */
	struct tt_softc *ts_ttp;	/* back ptr to dev-instance handle */
};

/*
 * Per-device instance state information.
 *
 * To aid in handling resource starvation situations, we pre-allocate two
 * messages for reporting errors.  Tt_merror is used as a last resort, when
 * attempts to allocate a normal error reply fail.  It's allocated in the
 * open routine and freed in the close routine.  The routines that produce
 * response messages try to keep tt_errack pre-allocated, but don't insist
 * that it always be valid.  This strategy attempts to minimize the
 * probability of having to fall back on the drastic measure of using the
 * M_ERROR message.
 */
struct tt_softc {
	/* The tt_unit & tt_unitnext fields aren't yet used. */
	struct tt_softc	*tt_next;	/* link to next device instance */
	u_short		tt_unit;	/* instance number */
	u_short		tt_unitnext;	/* next unit # to be used on open */

	queue_t		*tt_rq;		/* cross-link to read queue */
	struct socket	*tt_so;		/* socket for this device instance */
	mblk_t		*tt_merror;	/* pre-allocated M_ERROR message */
	mblk_t		*tt_errack;	/* pre-allocated T_error_ack message */
	u_int		tt_state;	/* current state of the tli automaton */
	u_long		tt_flags;	/* see below */
	u_long		tt_event;	/* service event inidication */
	struct	proc	*tt_auxprocp;	/* Aux proc handle */
};

/*
 * Flag (tt_flags) bits private to the driver.
 */
#define	TT_OPEN		0x01	/* device instance is currently open */
#define	TT_ERROR	0x02	/* in error state -- unusable */
#define	TT_CLOSE	0x04	/* this device instance is closed */
#define	TT_TIMER	0x08	/* scheduled wakeup timer is already set */
/*
 * Event (tt_event) bits private to the driver.
 */
#define	TTE_EVENT	0x01	/* aux proc service wanted indication */
#define	TTE_ONQUEUE	0x02	/* set if this ttp has wakeup-event pending */

/*
 * For use with direct-read only
 *  when:
 *    - TI is in the correct state
 *    - there are data to be read
 *    - socket is in state to receive
 *    - socket buffer not locked (we are running this
 *            at interrupt level !)
 */
#define	TT_DIRECT_READ(ttp, so) { \
	extern int udptli_auxproc_running; \
	if (((ttp)->tt_state & T_IDLE) && \
		((so)->so_rcv.sb_cc != 0) && \
		(!((so)->so_state & SS_CANTRCVMORE)) && \
		(!((so)->so_rcv.sb_flags & SB_LOCK)) && \
		(!udptli_auxproc_running))  \
		if (udptli_Ercv((ttp))) \
			return; \
}

#ifdef	TLIDEBUG
extern	udptli_debug;
#define	UDPTLI_PRINTF if (udptli_debug) (void)printf
#else
#define	UDPTLI_PRINTF
#endif	TLIDEBUG

#ifdef	KERNEL
extern struct tt_softc	tt_udpsoftc[];
#endif	KERNEL

#endif	_UDP_TLIVAR_