/*-
 *   Copyright (c) 1997 Joerg Wunsch. All rights reserved.
 *
 *   Copyright (c) 1997, 2002 Hellmuth Michaelis. All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *   
 *   THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *   ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 *   FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *   SUCH DAMAGE.
 */

/*---------------------------------------------------------------------------
 *
 *	i4b_isppp.c - isdn4bsd kernel SyncPPP driver
 *	--------------------------------------------
 *
 * 	Uses Serge Vakulenko's sppp backend (originally contributed with
 *	the "cx" driver for Cronyx's HDLC-in-hardware device).  This driver
 *	is only the glue between sppp and i4b.
 *
 *	last edit-date: [Sat Mar  9 14:09:27 2002]
 *
 *---------------------------------------------------------------------------*/

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_i4b.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/ioccom.h>
#include <sys/sockio.h>
#include <sys/kernel.h>

#include <net/if.h>
#include <net/if_types.h>
#include <net/if_sppp.h>

#include <sys/time.h>
#include <net/bpf.h>

#include <i4b/include/i4b_ioctl.h>
#include <i4b/include/i4b_debug.h>

#include <i4b/include/i4b_global.h>
#include <i4b/include/i4b_l3l4.h>

#include <i4b/layer4/i4b_l4.h>

#error "Cannot be used until I4B is locked."

#define ISPPP_FMT	"isp%d: "
#define	ISPPP_ARG(sc)	(sc->sc_ifp->if_dunit)
#define	PDEVSTATIC	static
#define IFP2UNIT(ifp)	(ifp)->if_dunit
		
#  define CALLOUT_INIT(chan)		callout_handle_init(chan)
#  define TIMEOUT(fun, arg, chan, tick)	chan = timeout(fun, arg, tick)
#  define UNTIMEOUT(fun, arg, chan)	untimeout(fun, arg, chan)
#  define IOCTL_CMD_T u_long

PDEVSTATIC void i4bispppattach(void *);
PSEUDO_SET(i4bispppattach, i4b_isppp);

#define I4BISPPPACCT		1	/* enable accounting messages */
#define	I4BISPPPACCTINTVL	2	/* accounting msg interval in secs */
#define I4BISPPPDISCDEBUG	1	

#define PPP_HDRLEN   		4	/* 4 octetts PPP header length	*/

struct i4bisppp_softc {
	struct ifnet *sc_ifp;

	int	sc_state;	/* state of the interface	*/
	call_desc_t *sc_cdp;	/* ptr to call descriptor	*/

#ifdef I4BISPPPACCT
	int sc_iinb;		/* isdn driver # of inbytes	*/
	int sc_ioutb;		/* isdn driver # of outbytes	*/
	int sc_inb;		/* # of bytes rx'd		*/
	int sc_outb;		/* # of bytes tx'd	 	*/
	int sc_linb;		/* last # of bytes rx'd		*/
	int sc_loutb;		/* last # of bytes tx'd 	*/
	int sc_fn;		/* flag, first null acct	*/
#endif

	struct callout_handle sc_ch;
} i4bisppp_softc[NI4BISPPP];

static void	i4bisppp_init_linktab(int unit);
static int	i4bisppp_ioctl(struct ifnet *ifp, IOCTL_CMD_T cmd, caddr_t data);

#if 0
static void	i4bisppp_send(struct ifnet *ifp);
#endif

static void	i4bisppp_start(struct ifnet *ifp);

#if 0 /* never used ??? */
static void	i4bisppp_timeout(void *cookie);
#endif

static void	i4bisppp_tls(struct sppp *sp);
static void	i4bisppp_tlf(struct sppp *sp);
static void	i4bisppp_state_changed(struct sppp *sp, int new_state);
static void	i4bisppp_negotiation_complete(struct sppp *sp);
static void	i4bisppp_watchdog(struct ifnet *ifp);
time_t   	i4bisppp_idletime(int unit);

/* initialized by L4 */

static drvr_link_t i4bisppp_drvr_linktab[NI4BISPPP];
static isdn_link_t *isdn_linktab[NI4BISPPP];

enum i4bisppp_states {
	ST_IDLE,			/* initialized, ready, idle	*/
	ST_DIALING,			/* dialling out to remote	*/
	ST_CONNECTED,			/* connected to remote		*/
};

/*===========================================================================*
 *			DEVICE DRIVER ROUTINES
 *===========================================================================*/

/*---------------------------------------------------------------------------*
 *	interface attach routine at kernel boot time
 *---------------------------------------------------------------------------*/
PDEVSTATIC void
i4bispppattach(void *dummy)
{
	struct i4bisppp_softc *sc = i4bisppp_softc;
	struct ifnet *ifp;
	int i;

#ifdef SPPP_VJ
	printf("i4bisppp: %d ISDN SyncPPP device(s) attached (VJ header compression)\n", NI4BISPPP);
#else
	printf("i4bisppp: %d ISDN SyncPPP device(s) attached\n", NI4BISPPP);
#endif

	for(i = 0; i < NI4BISPPP; sc++, i++) {
		i4bisppp_init_linktab(i);
		ifp = sc->sc_ifp = if_alloc(IFT_PPP);
		if (ifp == NULL) {
			panic("isp%d: cannot if_alloc()", i);
		}
		
		ifp->if_softc = sc;
		if_initname(sc->sc_ifp, "isp", i);
		ifp->if_mtu = PP_MTU;
		ifp->if_flags = IFF_SIMPLEX | IFF_POINTOPOINT;
		/*
		 * XXX: If there were a detach function this would
		 * require that it use if_free_type().  Not sure if this
		 * type makes sense.
		 */
		ifp->if_type = IFT_ISDNBASIC;
		sc->sc_state = ST_IDLE;

		ifp->if_ioctl = i4bisppp_ioctl;

		/* actually initialized by sppp_attach() */
		/* ifp->if_output = sppp_output; */

		ifp->if_start = i4bisppp_start;

		ifp->if_hdrlen = 0;
		ifp->if_addrlen = 0;
		ifp->if_snd.ifq_maxlen = IFQ_MAXLEN;

		ifp->if_ipackets = 0;
		ifp->if_ierrors = 0;
		ifp->if_opackets = 0;
		ifp->if_oerrors = 0;
		ifp->if_collisions = 0;
		ifp->if_ibytes = 0;
		ifp->if_obytes = 0;
		ifp->if_imcasts = 0;
		ifp->if_omcasts = 0;
		ifp->if_iqdrops = 0;
		ifp->if_noproto = 0;

#if I4BISPPPACCT
		ifp->if_timer = 0;	
		ifp->if_watchdog = i4bisppp_watchdog;	
		sc->sc_iinb = 0;
		sc->sc_ioutb = 0;
		sc->sc_inb = 0;
		sc->sc_outb = 0;
		sc->sc_linb = 0;
		sc->sc_loutb = 0;
		sc->sc_fn = 1;
#endif

		IFP2SP(sc->sc_ifp)->pp_tls = i4bisppp_tls;
		IFP2SP(sc->sc_ifp)->pp_tlf = i4bisppp_tlf;
		IFP2SP(sc->sc_ifp)->pp_con = i4bisppp_negotiation_complete;
		IFP2SP(sc->sc_ifp)->pp_chg = i4bisppp_state_changed;

		sppp_attach(sc->sc_ifp);

		if_attach(sc->sc_ifp);

		CALLOUT_INIT(&sc->sc_ch);
		
		bpfattach(sc->sc_ifp, DLT_PPP, PPP_HDRLEN);
	}
}

/*---------------------------------------------------------------------------*
 *	process ioctl
 *---------------------------------------------------------------------------*/
static int
i4bisppp_ioctl(struct ifnet *ifp, IOCTL_CMD_T cmd, caddr_t data)
{
	struct i4bisppp_softc *sc = ifp->if_softc;
#if 0
	struct sppp *sp = IFP2SP(sc->sc_ifp);
	struct ifaddr *ifa = (struct ifaddr *) data;
	struct ifreq *ifr = (struct ifreq *) data;
#endif

	int error;

	error = sppp_ioctl(sc->sc_ifp, cmd, data);
	if (error)
		return error;

	switch(cmd) {
	case SIOCSIFFLAGS:
#if 0 /* never used ??? */
		x = splimp();
		if ((ifp->if_flags & IFF_UP) == 0)
			UNTIMEOUT(i4bisppp_timeout, (void *)sp, sc->sc_ch);
		splx(x);
#endif
		break;
	}

	return 0;
}

/*---------------------------------------------------------------------------*
 *	start output to ISDN B-channel
 *---------------------------------------------------------------------------*/
static void
i4bisppp_start(struct ifnet *ifp)
{
	struct i4bisppp_softc *sc = ifp->if_softc;
	struct mbuf *m;
	/* int s; */
	int unit = IFP2UNIT(ifp);

	if (sppp_isempty(ifp))
		return;

	if(sc->sc_state != ST_CONNECTED)
		return;

	/*
	 * s = splimp();
	 * ifp->if_drv_flags |= IFF_DRV_OACTIVE; // - need to clear this somewhere
	 * splx(s);
	 */

	while ((m = sppp_dequeue(sc->sc_ifp)) != NULL)
	{

		BPF_MTAP(ifp, m);

		microtime(&ifp->if_lastchange);

		IF_LOCK(isdn_linktab[unit]->tx_queue);
		if(_IF_QFULL(isdn_linktab[unit]->tx_queue))
		{
			NDBGL4(L4_ISPDBG, "isp%d, tx queue full!", unit);
			m_freem(m);
		}
		else
		{
#if 0
			sc->sc_ifp->if_obytes += m->m_pkthdr.len;
#endif
			sc->sc_outb += m->m_pkthdr.len;
			sc->sc_ifp->if_opackets++;

			_IF_ENQUEUE(isdn_linktab[unit]->tx_queue, m);
		}
		IF_UNLOCK(isdn_linktab[unit]->tx_queue);
	}
	isdn_linktab[unit]->bch_tx_start(isdn_linktab[unit]->unit,
					 isdn_linktab[unit]->channel);
}

#ifdef I4BISPPPACCT
/*---------------------------------------------------------------------------*
 *	watchdog routine
 *---------------------------------------------------------------------------*/
static void
i4bisppp_watchdog(struct ifnet *ifp)
{
	struct i4bisppp_softc *sc = ifp->if_softc;
	int unit = IFP2UNIT(ifp);
	bchan_statistics_t bs;
	
	(*isdn_linktab[unit]->bch_stat)
		(isdn_linktab[unit]->unit, isdn_linktab[unit]->channel, &bs);

	sc->sc_ioutb += bs.outbytes;
	sc->sc_iinb += bs.inbytes;
	
	if((sc->sc_iinb != sc->sc_linb) || (sc->sc_ioutb != sc->sc_loutb) || sc->sc_fn)
	{
		int ri = (sc->sc_iinb - sc->sc_linb)/I4BISPPPACCTINTVL;
		int ro = (sc->sc_ioutb - sc->sc_loutb)/I4BISPPPACCTINTVL;

		if((sc->sc_iinb == sc->sc_linb) && (sc->sc_ioutb == sc->sc_loutb))
			sc->sc_fn = 0;
		else
			sc->sc_fn = 1;
			
		sc->sc_linb = sc->sc_iinb;
		sc->sc_loutb = sc->sc_ioutb;

		i4b_l4_accounting(BDRV_ISPPP, unit, ACCT_DURING,
			 sc->sc_ioutb, sc->sc_iinb, ro, ri, sc->sc_outb, sc->sc_inb);
 	}
	sc->sc_ifp->if_timer = I4BISPPPACCTINTVL; 	

#if 0 /* old stuff, keep it around */
	printf(ISPPP_FMT "transmit timeout\n", ISPPP_ARG(sc));
	i4bisppp_start(ifp);
#endif
}
#endif /* I4BISPPPACCT */

/*
 *===========================================================================*
 *			SyncPPP layer interface routines
 *===========================================================================*
 */

#if 0 /* never used ??? */
/*---------------------------------------------------------------------------*
 *	just an alias for i4bisppp_tls, but of type timeout_t
 *---------------------------------------------------------------------------*/
static void
i4bisppp_timeout(void *cookie)
{
	i4bisppp_tls((struct sppp *)cookie);
}
#endif

/*---------------------------------------------------------------------------*
 *	PPP this-layer-started action
 *---------------------------------------------------------------------------*
 */
static void
i4bisppp_tls(struct sppp *sp)
{
	struct ifnet *ifp = SP2IFP(sp);
	struct i4bisppp_softc *sc = ifp->if_softc;

	if(sc->sc_state == ST_CONNECTED)
		return;

	i4b_l4_dialout(BDRV_ISPPP, IFP2UNIT(ifp));
}

/*---------------------------------------------------------------------------*
 *	PPP this-layer-finished action
 *---------------------------------------------------------------------------*
 */
static void
i4bisppp_tlf(struct sppp *sp)
{
        struct ifnet *ifp = SP2IFP(sp);
	struct i4bisppp_softc *sc = ifp->if_softc;
/*	call_desc_t *cd = sc->sc_cdp;	*/
	
	if(sc->sc_state != ST_CONNECTED)
		return;

#if 0 /* never used ??? */
	UNTIMEOUT(i4bisppp_timeout, (void *)sp, sc->sc_ch);
#endif

	i4b_l4_drvrdisc(BDRV_ISPPP, IFP2UNIT(ifp));
}
/*---------------------------------------------------------------------------*
 *	PPP interface phase change
 *---------------------------------------------------------------------------*
 */
static void
i4bisppp_state_changed(struct sppp *sp, int new_state)
{
	struct i4bisppp_softc *sc = SP2IFP(sp)->if_softc;
	
	i4b_l4_ifstate_changed(sc->sc_cdp, new_state);
}

/*---------------------------------------------------------------------------*
 *	PPP control protocol negotiation complete (run ip-up script now)
 *---------------------------------------------------------------------------*
 */
static void
i4bisppp_negotiation_complete(struct sppp *sp)
{
	struct i4bisppp_softc *sc = SP2IFP(sp)->if_softc;
	
	i4b_l4_negcomplete(sc->sc_cdp);
}

/*===========================================================================*
 *			ISDN INTERFACE ROUTINES
 *===========================================================================*/

/*---------------------------------------------------------------------------*
 *	this routine is called from L4 handler at connect time
 *---------------------------------------------------------------------------*/
static void
i4bisppp_connect(int unit, void *cdp)
{
	struct i4bisppp_softc *sc = &i4bisppp_softc[unit];
	struct sppp *sp = IFP2SP(sc->sc_ifp);
	int s = splimp();

	sc->sc_cdp = (call_desc_t *)cdp;
	sc->sc_state = ST_CONNECTED;

#if I4BISPPPACCT
	sc->sc_iinb = 0;
	sc->sc_ioutb = 0;
	sc->sc_inb = 0;
	sc->sc_outb = 0;
	sc->sc_linb = 0;
	sc->sc_loutb = 0;
	sc->sc_ifp->if_timer = I4BISPPPACCTINTVL;
#endif
	
#if 0 /* never used ??? */
	UNTIMEOUT(i4bisppp_timeout, (void *)sp, sc->sc_ch);
#endif

	sp->pp_up(sp);		/* tell PPP we are ready */

	sp->pp_last_sent = sp->pp_last_recv = SECOND;

	splx(s);
}

/*---------------------------------------------------------------------------*
 *	this routine is called from L4 handler at disconnect time
 *---------------------------------------------------------------------------*/
static void
i4bisppp_disconnect(int unit, void *cdp)
{
	call_desc_t *cd = (call_desc_t *)cdp;
	struct i4bisppp_softc *sc = &i4bisppp_softc[unit];
	struct sppp *sp = IFP2SP(sc->sc_ifp);

	int s = splimp();

	/* new stuff to check that the active channel is being closed */
	if (cd != sc->sc_cdp)
	{
		NDBGL4(L4_ISPDBG, "isp%d, channel%d not active!", unit, cd->channelid);
		splx(s);
		return;
	}

#if I4BISPPPACCT
	sc->sc_ifp->if_timer = 0;
#endif

	i4b_l4_accounting(BDRV_ISPPP, unit, ACCT_FINAL,
		 sc->sc_ioutb, sc->sc_iinb, 0, 0, sc->sc_outb, sc->sc_inb);
	
	if (sc->sc_state == ST_CONNECTED)
	{
#if 0 /* never used ??? */
		UNTIMEOUT(i4bisppp_timeout, (void *)sp, sc->sc_ch);
#endif
		sc->sc_cdp = (call_desc_t *)0;	
		/* do this here because pp_down calls i4bisppp_tlf */
		sc->sc_state = ST_IDLE;
		sp->pp_down(sp);	/* tell PPP we have hung up */
	}

	splx(s);
}

/*---------------------------------------------------------------------------*
 *	this routine is used to give a feedback from userland demon
 *	in case of dial problems
 *---------------------------------------------------------------------------*/
static void
i4bisppp_dialresponse(int unit, int status, cause_t cause)
{
	struct i4bisppp_softc *sc = &i4bisppp_softc[unit];
	struct sppp *sp = IFP2SP(sc->sc_ifp);

	NDBGL4(L4_ISPDBG, "isp%d: status=%d, cause=%d", unit, status, cause);

	if(status != DSTAT_NONE)
	{
		struct mbuf *m;
		
		NDBGL4(L4_ISPDBG, "isp%d: clearing queues", unit);

		if(!(sppp_isempty(sc->sc_ifp)))
		{
			while((m = sppp_dequeue(sc->sc_ifp)) != NULL)
				m_freem(m);
		}

		sc->sc_cdp = (call_desc_t *)0;	
		/* do this here because pp_down calls i4bisppp_tlf */
		sc->sc_state = ST_IDLE;

		/*
		 * Ahh, sppp doesn't like to get a down event when
		 * dialing fails. So first tell it that we are up
		 * (doesn't hurt us since sc_state != ST_CONNECTED)
		 * and then go down.
		 */
		sp->pp_up(sp);
		sp->pp_down(sp);
	}
}
	
/*---------------------------------------------------------------------------*
 *	interface up/down
 *---------------------------------------------------------------------------*/
static void
i4bisppp_updown(int unit, int updown)
{
	/* could probably do something useful here */
}
	
/*---------------------------------------------------------------------------*
 *	this routine is called from the HSCX interrupt handler
 *	when a new frame (mbuf) has been received and was put on
 *	the rx queue.
 *---------------------------------------------------------------------------*/
static void
i4bisppp_rx_data_rdy(int unit)
{
	struct i4bisppp_softc *sc = &i4bisppp_softc[unit];
	struct mbuf *m;
	int s;
	
	if((m = *isdn_linktab[unit]->rx_mbuf) == NULL)
		return;

	m->m_pkthdr.rcvif = sc->sc_ifp;
	m->m_pkthdr.len = m->m_len;

	microtime(&sc->sc_ifp->if_lastchange);

	sc->sc_ifp->if_ipackets++;
#if 0
	sc->sc_ifp->if_ibytes += m->m_pkthdr.len;
#endif

#if I4BISPPPACCT
	sc->sc_inb += m->m_pkthdr.len;
#endif
	
#ifdef I4BISPPPDEBUG
	printf("i4bisppp_rx_data_ready: received packet!\n");
#endif

	BPF_MTAP(sc->sc_ifp, m);

	s = splimp();

	sppp_input(sc->sc_ifp, m);

	splx(s);
}

/*---------------------------------------------------------------------------*
 *	this routine is called from the HSCX interrupt handler
 *	when the last frame has been sent out and there is no
 *	further frame (mbuf) in the tx queue.
 *---------------------------------------------------------------------------*/
static void
i4bisppp_tx_queue_empty(int unit)
{
	i4bisppp_start((&i4bisppp_softc[unit])->sc_ifp);	
}

/*---------------------------------------------------------------------------*
 *	THIS should be used instead of last_active_time to implement
 *	an activity timeout mechanism.
 *
 *	Sending back the time difference unneccessarily complicates the
 *	idletime checks in i4b_l4.c. Return the largest time instead.
 *	That way the code in i4b_l4.c needs only minimal changes.
 *---------------------------------------------------------------------------*/
time_t
i4bisppp_idletime(int unit)
{
	struct sppp *sp = IFP2SP((&i4bisppp_softc[unit])->sc_ifp);

	return((sp->pp_last_recv < sp->pp_last_sent) ?
			sp->pp_last_sent : sp->pp_last_recv);
}

/*---------------------------------------------------------------------------*
 *	this routine is called from the HSCX interrupt handler
 *	each time a packet is received or transmitted. It should
 *	be used to implement an activity timeout mechanism.
 *---------------------------------------------------------------------------*/
static void
i4bisppp_activity(int unit, int rxtx)
{
	i4bisppp_softc[unit].sc_cdp->last_active_time = SECOND;
}

/*---------------------------------------------------------------------------*
 *	return this drivers linktab address
 *---------------------------------------------------------------------------*/
drvr_link_t *
i4bisppp_ret_linktab(int unit)
{
	return(&i4bisppp_drvr_linktab[unit]);
}

/*---------------------------------------------------------------------------*
 *	setup the isdn_linktab for this driver
 *---------------------------------------------------------------------------*/
void
i4bisppp_set_linktab(int unit, isdn_link_t *ilt)
{
	isdn_linktab[unit] = ilt;
}

/*---------------------------------------------------------------------------*
 *	initialize this drivers linktab
 *---------------------------------------------------------------------------*/
static void
i4bisppp_init_linktab(int unit)
{
	i4bisppp_drvr_linktab[unit].unit = unit;
	i4bisppp_drvr_linktab[unit].bch_rx_data_ready = i4bisppp_rx_data_rdy;
	i4bisppp_drvr_linktab[unit].bch_tx_queue_empty = i4bisppp_tx_queue_empty;
	i4bisppp_drvr_linktab[unit].bch_activity = i4bisppp_activity;
	i4bisppp_drvr_linktab[unit].line_connected = i4bisppp_connect;
	i4bisppp_drvr_linktab[unit].line_disconnected = i4bisppp_disconnect;
	i4bisppp_drvr_linktab[unit].dial_response = i4bisppp_dialresponse;	
	i4bisppp_drvr_linktab[unit].updown_ind = i4bisppp_updown;	
}

/*===========================================================================*/