www.pudn.com > vxworks_tcpip_code.rar > lcp.c


/* lcp.c - PPP Link Control Protocol */

/* Copyright 1995 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/*
modification history
--------------------
01d,14apr97,vin  lcp state machine fixes from ppp-2.3b3, corrected the
		 problem of lcp_reqci generating CONFREJ instead of CONFNAKs.
01e,10dec96,vin  fixed additional problem with lcp_finished(), SPR7604.
01d,15nov96,vin  fixed lcp_finished(), calls fsm_open() if OPT_RESTART
		 is specified. This will cause the ppp deamon task
		 to wait for the next connection. This is typically useful
		 when vxWorks target is acting as a ppp server.
		 Added flag OPT_RESTART if passive or silent options are 
		 specified.
01c,16jun95,dzb  header file consolidation.
                 changed [UN]TIMEOUT macros to PPP_[UN]TIMEOUT.
01b,09feb95,dab  ensure ao->mru is not 0 when setting interface mtu.
                 removed lcp_echo_fails_reached variable.
01a,21dec94,dab  VxWorks port - first WRS version.
	   +dzb  added: path for ppp header files, WRS copyright.
*/

#include "vxWorks.h"
#include "stdio.h"
#include "string.h"
#include "sys/ioctl.h"
#include "sys/types.h"
#include "sys/socket.h"
#include "sys/times.h"
#include "netinet/in.h"
#include "pppLib.h"

/*
 * Callbacks for fsm code.  (CI = Configuration Information)
 */
static void lcp_resetci __ARGS((fsm *));	/* Reset our CI */
static int  lcp_cilen __ARGS((fsm *));		/* Return length of our CI */
static void lcp_addci __ARGS((fsm *, u_char *, int *)); /* Add our CI to pkt */
static int  lcp_ackci __ARGS((fsm *, u_char *, int)); /* Peer ack'd our CI */
static int  lcp_nakci __ARGS((fsm *, u_char *, int)); /* Peer nak'd our CI */
static int  lcp_rejci __ARGS((fsm *, u_char *, int)); /* Peer rej'd our CI */
static int  lcp_reqci __ARGS((fsm *, u_char *, int *, int)); /* Rcv peer CI */
static void lcp_up __ARGS((fsm *));		/* We're UP */
static void lcp_down __ARGS((fsm *));		/* We're DOWN */
static void lcp_starting __ARGS((fsm *));	/* We need lower layer up */
static void lcp_finished __ARGS((fsm *));	/* We need lower layer down */
static int  lcp_extcode __ARGS((fsm *, int, int, u_char *, int));
static void lcp_rprotrej __ARGS((fsm *, u_char *, int));

/*
 * routines to send LCP echos to peer
 */

static void lcp_echo_lowerup __ARGS((int));
static void lcp_echo_lowerdown __ARGS((int));
static void LcpEchoTimeout __ARGS((caddr_t));
static void lcp_received_echo_reply __ARGS((fsm *, int, u_char *, int));
static void LcpSendEchoRequest __ARGS((fsm *));
static void LcpLinkFailure __ARGS((fsm *));

static fsm_callbacks lcp_callbacks = {	/* LCP callback routines */
    lcp_resetci,		/* Reset our Configuration Information */
    lcp_cilen,			/* Length of our Configuration Information */
    lcp_addci,			/* Add our Configuration Information */
    lcp_ackci,			/* ACK our Configuration Information */
    lcp_nakci,			/* NAK our Configuration Information */
    lcp_rejci,			/* Reject our Configuration Information */
    lcp_reqci,			/* Request peer's Configuration Information */
    lcp_up,			/* Called when fsm reaches OPENED state */
    lcp_down,			/* Called when fsm leaves OPENED state */
    lcp_starting,		/* Called when we want the lower layer up */
    lcp_finished,		/* Called when we want the lower layer down */
    NULL,			/* Called when Protocol-Reject received */
    NULL,			/* Retransmission is necessary */
    lcp_extcode,		/* Called to handle LCP-specific codes */
    "LCP"			/* String name of protocol */
};

int lcp_warnloops = DEFWARNLOOPS; /* Warn about a loopback this often */

/*
 * Length of each type of configuration option (in octets)
 */
#define CILEN_VOID	2
#define CILEN_SHORT	4	/* CILEN_VOID + sizeof(short) */
#define CILEN_CHAP	5	/* CILEN_VOID + sizeof(short) + 1 */
#define CILEN_LONG	6	/* CILEN_VOID + sizeof(long) */
#define CILEN_LQR	8	/* CILEN_VOID + sizeof(short) + sizeof(long) */

#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
			 (x) == CONFNAK ? "NAK" : "REJ")

static u_char nak_buffer[PPP_MRU];	/* where we construct a nak packet */

/*
 * lcp_init - Initialize LCP.
 */
void
lcp_init(unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->lcp_fsm;
    lcp_options *wo = &ppp_if[unit]->lcp_wantoptions;
    lcp_options *ao = &ppp_if[unit]->lcp_allowoptions;

    f->unit = unit;
    f->protocol = LCP;
    f->callbacks = &lcp_callbacks;

    fsm_init(f);

    wo->passive = 0;
    wo->silent = 0;
    wo->restart = 0;			/* Set to 1 in kernels or multi-line
					   implementations */
    wo->neg_mru = 1;
    wo->mru = DEFMRU;
    wo->neg_asyncmap = 0;
    wo->asyncmap = 0;
    wo->neg_chap = 0;			/* Set to 1 on server */
    wo->neg_upap = 0;			/* Set to 1 on server */
    wo->chap_mdtype = CHAP_DIGEST_MD5;
    wo->neg_magicnumber = 1;
    wo->neg_pcompression = 1;
    wo->neg_accompression = 1;
    wo->neg_lqr = 0;			/* no LQR implementation yet */

    ao->neg_mru = 1;
    ao->mru = MAXMRU;
    ao->neg_asyncmap = 1;
    ao->asyncmap = 0;
    ao->neg_chap = 1;
    ao->chap_mdtype = CHAP_DIGEST_MD5;
    ao->neg_upap = 1;
    ao->neg_magicnumber = 1;
    ao->neg_pcompression = 1;
    ao->neg_accompression = 1;
    ao->neg_lqr = 0;			/* no LQR implementation yet */

    bzero((char *)ppp_if[unit]->xmit_accm, sizeof(ppp_if[unit]->xmit_accm[0]));
    ppp_if[unit]->xmit_accm[3] = 0x60000000;
}


/*
 * lcp_open - LCP is allowed to come up.
 */
void
lcp_open(unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->lcp_fsm;
    lcp_options *wo = &ppp_if[unit]->lcp_wantoptions;

    f->flags = 0;
    if (wo->passive)
	f->flags |= (OPT_PASSIVE | OPT_RESTART) ;
    if (wo->silent)
	f->flags |= (OPT_SILENT | OPT_RESTART);
    fsm_open(f);
}


/*
 * lcp_close - Take LCP down.
 */
void
lcp_close(unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->lcp_fsm;

    if (f->state == STOPPED && f->flags & (OPT_PASSIVE|OPT_SILENT)) {
        /*
         * This action is not strictly according to the FSM in RFC1548,
         * but it does mean that the program terminates if you do a
         * lcp_close(0) in passive/silent mode when a connection hasn't
         * been established.
         */
        f->state = CLOSED;
        lcp_finished(f);

    } else
        fsm_close(&ppp_if[unit]->lcp_fsm);
}


/*
 * lcp_lowerup - The lower layer is up.
 */
void
lcp_lowerup(unit)
    int unit;
{
    sifdown(unit);
    ppp_set_xaccm(unit, ppp_if[unit]->xmit_accm);
    ppp_send_config(unit, MTU, 0xffffffff, 0, 0);
    ppp_recv_config(unit, MTU, 0x00000000, 0, 0);
    ppp_if[unit]->peer_mru = MTU;
    ppp_if[unit]->lcp_allowoptions.asyncmap = ppp_if[unit]->xmit_accm[0];

    fsm_lowerup(&ppp_if[unit]->lcp_fsm);
}


/*
 * lcp_lowerdown - The lower layer is down.
 */
void
lcp_lowerdown(unit)
    int unit;
{
    fsm_lowerdown(&ppp_if[unit]->lcp_fsm);
}


/*
 * lcp_input - Input LCP packet.
 */
void
lcp_input(unit, p, len)
    int unit;
    u_char *p;
    int len;
{
    fsm_input(&ppp_if[unit]->lcp_fsm, p, len);
}


/*
 * lcp_extcode - Handle a LCP-specific code.
 */
static int
lcp_extcode(f, code, id, inp, len)
    fsm *f;
    int code, id;
    u_char *inp;
    int len;
{
    u_char *magp;

    switch( code ){
    case PROTREJ:
	lcp_rprotrej(f, inp, len);
	break;
    
    case ECHOREQ:
	if (f->state != OPENED)
	    break;
	LCPDEBUG((LOG_INFO, "lcp: Echo-Request, Rcvd id %d", id));
        magp = inp;
        PUTLONG(ppp_if[f->unit]->lcp_gotoptions.magicnumber, magp);
        if (len < CILEN_LONG)
            len = CILEN_LONG;
	fsm_sdata(f, ECHOREP, id, inp, len);
	break;
    
    case ECHOREP:
        lcp_received_echo_reply(f, id, inp, len);
        break;

    case DISCREQ:
	break;

    default:
	return 0;
    }
    return 1;
}

    
/*
 * lcp_rprotrej - Receive an Protocol-Reject.
 *
 * Figure out which protocol is rejected and inform it.
 */
static void
lcp_rprotrej(f, inp, len)
    fsm *f;
    u_char *inp;
    int len;
{
    u_short prot;

    LCPDEBUG((LOG_INFO, "lcp_rprotrej."));

    if (len < sizeof (u_short)) {
	LCPDEBUG((LOG_INFO,
                  "lcp_rprotrej: Rcvd short Protocol-Reject packet!"));
	return;
    }

    GETSHORT(prot, inp);

    LCPDEBUG((LOG_INFO,
              "lcp_rprotrej: Rcvd Protocol-Reject packet for %x!",
	      prot));

    /*
     * Protocol-Reject packets received in any state other than the LCP
     * OPENED state SHOULD be silently discarded.
     */
    if( f->state != OPENED ){
	LCPDEBUG((LOG_INFO, "Protocol-Reject discarded: LCP in state %d",
                  f->state));
	return;
    }

    DEMUXPROTREJ(f->unit, prot);	/* Inform protocol */
}


/*
 * lcp_protrej - A Protocol-Reject was received.
 */
/*ARGSUSED*/
void
lcp_protrej(unit)
    int unit;
{
    /*
     * Can't reject LCP!
     */
    LCPDEBUG((LOG_WARNING,
              "lcp_protrej: Received Protocol-Reject for LCP!"));
    fsm_protreject(&ppp_if[unit]->lcp_fsm);
}


/*
 * lcp_sprotrej - Send a Protocol-Reject for some protocol.
 */
void
lcp_sprotrej(unit, p, len)
    int unit;
    u_char *p;
    int len;
{
    /*
     * Send back the protocol and the information field of the
     * rejected packet.  We only get here if LCP is in the OPENED state.
     */
    p += 2;
    len -= 2;

    fsm_sdata(&ppp_if[unit]->lcp_fsm, PROTREJ, ++ppp_if[unit]->lcp_fsm.id,
	      p, len);
}


/*
 * lcp_resetci - Reset our CI.
 */
static void
  lcp_resetci(f)
fsm *f;
{
    ppp_if[f->unit]->lcp_wantoptions.magicnumber = magic();
    ppp_if[f->unit]->lcp_wantoptions.numloops = 0;
    ppp_if[f->unit]->lcp_gotoptions = ppp_if[f->unit]->lcp_wantoptions;
    ppp_if[f->unit]->peer_mru = MTU;
}


/*
 * lcp_cilen - Return length of our CI.
 */
static int
lcp_cilen(f)
    fsm *f;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;

#define LENCIVOID(neg)	(neg ? CILEN_VOID : 0)
#define LENCICHAP(neg)	(neg ? CILEN_CHAP : 0)
#define LENCISHORT(neg)	(neg ? CILEN_SHORT : 0)
#define LENCILONG(neg)	(neg ? CILEN_LONG : 0)
#define LENCILQR(neg)	(neg ? CILEN_LQR: 0)
    /*
     * NB: we only ask for one of CHAP and UPAP, even if we will
     * accept either.
     */
    return (LENCISHORT(go->neg_mru) +
	    LENCILONG(go->neg_asyncmap) +
	    LENCICHAP(go->neg_chap) +
	    LENCISHORT(!go->neg_chap && go->neg_upap) +
	    LENCILQR(go->neg_lqr) +
	    LENCILONG(go->neg_magicnumber) +
	    LENCIVOID(go->neg_pcompression) +
	    LENCIVOID(go->neg_accompression));
}


/*
 * lcp_addci - Add our desired CIs to a packet.
 */
static void
lcp_addci(f, ucp, lenp)
    fsm *f;
    u_char *ucp;
    int *lenp;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    u_char *start_ucp = ucp;

#define ADDCIVOID(opt, neg) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_VOID, ucp); \
    }
#define ADDCISHORT(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_SHORT, ucp); \
	PUTSHORT(val, ucp); \
    }
#define ADDCICHAP(opt, neg, val, digest) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_CHAP, ucp); \
	PUTSHORT(val, ucp); \
	PUTCHAR(digest, ucp); \
    }
#define ADDCILONG(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_LONG, ucp); \
	PUTLONG(val, ucp); \
    }
#define ADDCILQR(opt, neg, val) \
    if (neg) { \
	PUTCHAR(opt, ucp); \
	PUTCHAR(CILEN_LQR, ucp); \
	PUTSHORT(LQR, ucp); \
	PUTLONG(val, ucp); \
    }

    ADDCISHORT(CI_MRU, go->neg_mru, go->mru);
    ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap);
    ADDCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype);
    ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP);
    ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
    ADDCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
    ADDCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
    ADDCIVOID(CI_ACCOMPRESSION, go->neg_accompression);

    if (ucp - start_ucp != *lenp) {
	/* this should never happen, because peer_mtu should be 1500 */
	syslog(LOG_ERR, "Bug in lcp_addci: wrong length");
    }
}


/*
 * lcp_ackci - Ack our CIs.
 * This should not modify any state if the Ack is bad.
 *
 * Returns:
 *	0 - Ack was bad.
 *	1 - Ack was good.
 */
static int
lcp_ackci(f, p, len)
    fsm *f;
    u_char *p;
    int len;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    u_char cilen, citype, cichar;
    u_short cishort;
    u_long cilong;

    /*
     * CIs must be in exactly the same order that we sent.
     * Check packet length and CI length at each step.
     * If we find any deviations, then this packet is bad.
     */
#define ACKCIVOID(opt, neg) \
    if (neg) { \
	if ((len -= CILEN_VOID) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_VOID || \
	    citype != opt) \
	    goto bad; \
    }
#define ACKCISHORT(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_SHORT) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_SHORT || \
	    citype != (u_char)opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != (u_short)val) \
	    goto bad; \
    }
#define ACKCICHAP(opt, neg, val, digest) \
    if (neg) { \
	if ((len -= CILEN_CHAP) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_CHAP || \
	    citype != (u_char)opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != (u_short)val) \
	    goto bad; \
	GETCHAR(cichar, p); \
	if (cichar != (u_char)digest) \
	  goto bad; \
    }
#define ACKCILONG(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LONG) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LONG || \
	    citype != (u_char)opt) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != (u_long)val) \
	    goto bad; \
    }
#define ACKCILQR(opt, neg, val) \
    if (neg) { \
	if ((len -= CILEN_LQR) < 0) \
	    goto bad; \
	GETCHAR(citype, p); \
	GETCHAR(cilen, p); \
	if (cilen != CILEN_LQR || \
	    citype != (u_char)opt) \
	    goto bad; \
	GETSHORT(cishort, p); \
	if (cishort != LQR) \
	    goto bad; \
	GETLONG(cilong, p); \
	if (cilong != (u_long)val) \
	  goto bad; \
    }

    ACKCISHORT(CI_MRU, go->neg_mru, go->mru);
    ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap, go->asyncmap);
    ACKCICHAP(CI_AUTHTYPE, go->neg_chap, CHAP, go->chap_mdtype);
    ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, UPAP);
    ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
    ACKCILONG(CI_MAGICNUMBER, go->neg_magicnumber, go->magicnumber);
    ACKCIVOID(CI_PCOMPRESSION, go->neg_pcompression);
    ACKCIVOID(CI_ACCOMPRESSION, go->neg_accompression);

    /*
     * If there are any remaining CIs, then this packet is bad.
     */
    if (len != 0)
	goto bad;
    return (1);
bad:
    LCPDEBUG((LOG_WARNING, "lcp_acki: received bad Ack!"));
    return (0);
}


/*
 * lcp_nakci - Peer has sent a NAK for some of our CIs.
 * This should not modify any state if the Nak is bad
 * or if LCP is in the OPENED state.
 *
 * Returns:
 *	0 - Nak was bad.
 *	1 - Nak was good.
 */
static int
lcp_nakci(f, p, len)
    fsm *f;
    u_char *p;
    int len;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    lcp_options *wo = &ppp_if[f->unit]->lcp_wantoptions;
    u_char cilen, citype, cichar, *next;
    u_short cishort = 0;
    u_long cilong;
    lcp_options no;		/* options we've seen Naks for */
    lcp_options try;		/* options to request next time */
    int looped_back = 0;

    BZERO((char *)&no, sizeof(no));
    try = *go;

    /*
     * Any Nak'd CIs must be in exactly the same order that we sent.
     * Check packet length and CI length at each step.
     * If we find any deviations, then this packet is bad.
     */
#define NAKCIVOID(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_VOID && \
	p[1] == CILEN_VOID && \
	p[0] == opt) { \
	len -= CILEN_VOID; \
	INCPTR(CILEN_VOID, p); \
	no.neg = 1; \
	code \
    }
#define NAKCICHAP(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	no.neg = 1; \
	code \
    }
#define NAKCISHORT(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_SHORT && \
	p[1] == CILEN_SHORT && \
	p[0] == opt) { \
	len -= CILEN_SHORT; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	no.neg = 1; \
	code \
    }
#define NAKCILONG(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_LONG && \
	p[1] == CILEN_LONG && \
	p[0] == opt) { \
	len -= CILEN_LONG; \
	INCPTR(2, p); \
	GETLONG(cilong, p); \
	no.neg = 1; \
	code \
    }
#define NAKCILQR(opt, neg, code) \
    if (go->neg && \
	len >= CILEN_LQR && \
	p[1] == CILEN_LQR && \
	p[0] == opt) { \
	len -= CILEN_LQR; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETLONG(cilong, p); \
	no.neg = 1; \
	code \
    }

    /*
     * We don't care if they want to send us smaller packets than
     * we want.  Therefore, accept any MRU less than what we asked for,
     * but then ignore the new value when setting the MRU in the kernel.
     * If they send us a bigger MRU than what we asked, accept it, up to
     * the limit of the default MRU we'd get if we didn't negotiate.
     */
    NAKCISHORT(CI_MRU, neg_mru,
	       if (cishort <= wo->mru || cishort < DEFMRU)
		   try.mru = cishort;
	       );
    /*
     * Add any characters they want to our (receive-side) asyncmap.
     */
    NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
	      try.asyncmap = go->asyncmap | cilong;
	      );
    /*
     * If they can't cope with our CHAP hash algorithm, we'll have
     * to stop asking for CHAP.  We haven't got any other algorithm.
     */
    NAKCICHAP(CI_AUTHTYPE, neg_chap,
	      try.neg_chap = 0;
	      );
    /*
     * Peer shouldn't send Nak for UPAP, protocol compression or
     * address/control compression requests; they should send
     * a Reject instead.  If they send a Nak, treat it as a Reject.
     */
    if (!go->neg_chap ){
	NAKCISHORT(CI_AUTHTYPE, neg_upap,
		   try.neg_upap = 0;
		   );
    }
    /*
     * If they can't cope with our link quality protocol, we'll have
     * to stop asking for LQR.  We haven't got any other protocol.
     * If they Nak the reporting period, take their value XXX ?
     */
    NAKCILQR(CI_QUALITY, neg_lqr,
	      if (cishort != LQR)
		  try.neg_lqr = 0;
	      else
	          try.lqr_period = cilong;
	      );
    /*
     * Check for a looped-back line.
     */
    NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
	      try.magicnumber = magic();
	      ++try.numloops;
	      looped_back = 1;
	      );

    NAKCIVOID(CI_PCOMPRESSION, neg_pcompression,
	      try.neg_pcompression = 0;
	      );
    NAKCIVOID(CI_ACCOMPRESSION, neg_accompression,
	      try.neg_accompression = 0;
	      );

    /*
     * There may be remaining CIs, if the peer is requesting negotiation
     * on an option that we didn't include in our request packet.
     * If we see an option that we requested, or one we've already seen
     * in this packet, then this packet is bad.
     * If we wanted to respond by starting to negotiate on the requested
     * option(s), we could, but we don't, because except for the
     * authentication type and quality protocol, if we are not negotiating
     * an option, it is because we were told not to.
     * For the authentication type, the Nak from the peer means
     * `let me authenticate myself with you' which is a bit pointless.
     * For the quality protocol, the Nak means `ask me to send you quality
     * reports', but if we didn't ask for them, we don't want them.
     */
    while (len > CILEN_VOID) {
	GETCHAR(citype, p);
	GETCHAR(cilen, p);
	if( (len -= cilen) < 0 )
	    goto bad;
	next = p + cilen - 2;

	switch (citype) {
	case CI_MRU:
	    if (go->neg_mru || no.neg_mru || cilen != CILEN_SHORT)
		goto bad;
	    break;
	case CI_ASYNCMAP:
	    if (go->neg_asyncmap || no.neg_asyncmap || cilen != CILEN_LONG)
		goto bad;
	    break;
	case CI_AUTHTYPE:
	    if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap)
		goto bad;
	    break;
	case CI_MAGICNUMBER:
	    if (go->neg_magicnumber || no.neg_magicnumber ||
		cilen != CILEN_LONG)
		goto bad;
	    break;
	case CI_PCOMPRESSION:
	    if (go->neg_pcompression || no.neg_pcompression
		|| cilen != CILEN_VOID)
		goto bad;
	    break;
	case CI_ACCOMPRESSION:
	    if (go->neg_accompression || no.neg_accompression
		|| cilen != CILEN_VOID)
		goto bad;
	    break;
	case CI_QUALITY:
	    if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)
		goto bad;
	    break;
	default:
	    goto bad;
	}
	p = next;
    }

    /* If there is still anything left, this packet is bad. */
    if (len != 0)
	goto bad;

    /*
     * OK, the Nak is good.  Now we can update state.
     */
    if (f->state != OPENED) {
	*go = try;
	if (looped_back && try.numloops % lcp_warnloops == 0)
	    LCPDEBUG((LOG_INFO, "The line appears to be looped back."));
    }

    return 1;

bad:
    LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!"));
    return 0;
}


/*
 * lcp_rejci - Peer has Rejected some of our CIs.
 * This should not modify any state if the Reject is bad
 * or if LCP is in the OPENED state.
 *
 * Returns:
 *	0 - Reject was bad.
 *	1 - Reject was good.
 */
static int
lcp_rejci(f, p, len)
    fsm *f;
    u_char *p;
    int len;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    u_char cichar = 0;
    u_short cishort;
    u_long cilong;
#ifdef	DEBUGLCP
    u_char *start = p;
    int plen = len;
#endif	/* DEBUGLCP */
    lcp_options try;		/* options to request next time */

    try = *go;

    /*
     * Any Rejected CIs must be in exactly the same order that we sent.
     * Check packet length and CI length at each step.
     * If we find any deviations, then this packet is bad.
     */
#define REJCIVOID(opt, neg) \
    if (go->neg && \
	len >= CILEN_VOID && \
	p[1] == CILEN_VOID && \
	p[0] == opt) { \
	len -= CILEN_VOID; \
	INCPTR(CILEN_VOID, p); \
	try.neg = 0; \
	LCPDEBUG((LOG_INFO, "lcp_rejci rejected void opt %d", opt)); \
    }
#define REJCISHORT(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_SHORT && \
	p[1] == CILEN_SHORT && \
	p[0] == opt) { \
	len -= CILEN_SHORT; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	/* Check rejected value. */ \
	if (cishort != (u_short)val) \
	    goto bad; \
	try.neg = 0; \
	LCPDEBUG((LOG_INFO,"lcp_rejci rejected short opt %d", opt)); \
    }
#define REJCICHAP(opt, neg, val, digest) \
    if (go->neg && \
	len >= CILEN_CHAP && \
	p[1] == CILEN_CHAP && \
	p[0] == opt) { \
	len -= CILEN_CHAP; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETCHAR(cichar, p); \
	/* Check rejected value. */ \
	if (cishort != (u_short)val || cichar != (u_char)digest) \
	    goto bad; \
	try.neg = 0; \
	LCPDEBUG((LOG_INFO,"lcp_rejci rejected chap opt %d", opt)); \
    }
#define REJCILONG(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LONG && \
	p[1] == CILEN_LONG && \
	p[0] == opt) { \
	len -= CILEN_LONG; \
	INCPTR(2, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cilong != (u_long)val) \
	    goto bad; \
	try.neg = 0; \
	LCPDEBUG((LOG_INFO,"lcp_rejci rejected long opt %d", opt)); \
    }
#define REJCILQR(opt, neg, val) \
    if (go->neg && \
	len >= CILEN_LQR && \
	p[1] == CILEN_LQR && \
	p[0] == opt) { \
	len -= CILEN_LQR; \
	INCPTR(2, p); \
	GETSHORT(cishort, p); \
	GETLONG(cilong, p); \
	/* Check rejected value. */ \
	if (cishort != LQR || cilong != val) \
	    goto bad; \
	try.neg = 0; \
	LCPDEBUG((LOG_INFO,"lcp_rejci rejected LQR opt %d", opt)); \
    }

    REJCISHORT(CI_MRU, neg_mru, go->mru);
    REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
    REJCICHAP(CI_AUTHTYPE, neg_chap, CHAP, go->chap_mdtype);
    if (!go->neg_chap) {
	REJCISHORT(CI_AUTHTYPE, neg_upap, UPAP);
    }
    REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
    REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);
    REJCIVOID(CI_PCOMPRESSION, neg_pcompression);
    REJCIVOID(CI_ACCOMPRESSION, neg_accompression);

    /*
     * If there are any remaining CIs, then this packet is bad.
     */
    if (len != 0)
	goto bad;
    /*
     * Now we can update state.
     */
    if (f->state != OPENED)
	*go = try;
    return 1;

bad:
    LCPDEBUG((LOG_WARNING, "lcp_rejci: received bad Reject!"));
    LCPDEBUG((LOG_WARNING, "lcp_rejci: plen %d len %d off %d",
              plen, len, p - start));
    return 0;
}


/*
 * lcp_reqci - Check the peer's requested CIs and send appropriate response.
 *
 * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified
 * appropriately.  If reject_if_disagree is non-zero, doesn't return
 * CONFNAK; returns CONFREJ if it can't return CONFACK.
 */
static int
lcp_reqci(f, inp, lenp, reject_if_disagree)
    fsm *f;
    u_char *inp;                /* Requested CIs */
    int *lenp;                  /* Length of requested CIs */
    int reject_if_disagree;
{
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    lcp_options *ho = &ppp_if[f->unit]->lcp_hisoptions;
    lcp_options *ao = &ppp_if[f->unit]->lcp_allowoptions;
    u_char *cip, *next;		/* Pointer to current and next CIs */
    u_char cilen, citype = 0, cichar;/* Parsed len, type, char value */
    u_short cishort;		/* Parsed short value */
    u_long cilong;		/* Parse long value */
    int rc = CONFACK;		/* Final packet return code */
    int orc;			/* Individual option return code */
    u_char *p;			/* Pointer to next char to parse */
    u_char *rejp;		/* Pointer to next char in reject frame */
    u_char *nakp;		/* Pointer to next char in Nak frame */
    int l = *lenp;		/* Length left */

    /*
     * Reset all his options.
     */
    BZERO((char *)ho, sizeof(*ho));

    /*
     * Process all his options.
     */
    next = inp;
    nakp = nak_buffer;
    rejp = inp;
    while (l) {
	orc = CONFACK;			/* Assume success */
	cip = p = next;			/* Remember begining of CI */
	if (l < 2 ||			/* Not enough data for CI header or */
	    p[1] < 2 ||			/*  CI length too small or */
	    p[1] > l) {			/*  CI length too big? */
	    LCPDEBUG((LOG_WARNING, "lcp_reqci: bad CI length!"));
	    orc = CONFREJ;		/* Reject bad CI */
	    cilen = l;			/* Reject till end of packet */
	    l = 0;			/* Don't loop again */
	    goto endswitch;
	}
	GETCHAR(citype, p);		/* Parse CI type */
	GETCHAR(cilen, p);		/* Parse CI length */
	l -= cilen;			/* Adjust remaining length */
	next += cilen;			/* Step to next CI */

	switch (citype) {		/* Check CI type */
	case CI_MRU:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MRU"));
	    if (!ao->neg_mru ||		/* Allow option? */
		cilen != CILEN_SHORT) {	/* Check CI length */
		orc = CONFREJ;		/* Reject CI */
		break;
	    }
	    GETSHORT(cishort, p);	/* Parse MRU */
	    LCPDEBUG((LOG_INFO, "(%d)", cishort));

	    /*
	     * He must be able to receive at least our minimum.
	     * No need to check a maximum.  If he sends a large number,
	     * we'll just ignore it.
	     */
	    if (cishort < MINMRU) {
		orc = CONFNAK;		/* Nak CI */
		if( !reject_if_disagree ){
		    DECPTR(sizeof (short), p);	/* Backup */
		    PUTSHORT(MINMRU, p);	/* Give him a hint */
		}
		break;
	    }
	    ho->neg_mru = 1;		/* Remember he sent MRU */
	    ho->mru = cishort;		/* And remember value */
	    break;

	case CI_ASYNCMAP:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ASYNCMAP"));
	    if (!ao->neg_asyncmap ||
		cilen != CILEN_LONG) {
		orc = CONFREJ;
		break;
	    }
	    GETLONG(cilong, p);
	    LCPDEBUG((LOG_INFO, "(%lx)", cilong));

	    /*
	     * Asyncmap must have set at least the bits
	     * which are set in lcp_allowoptions[unit].asyncmap.
	     */
	    if ((ao->asyncmap & ~cilong) != 0) {
		orc = CONFNAK;
		if( !reject_if_disagree ){
		    DECPTR(sizeof (long), p);
		    PUTLONG(ao->asyncmap | cilong, p);
		}
		break;
	    }
	    ho->neg_asyncmap = 1;
	    ho->asyncmap = cilong;
	    break;

	case CI_AUTHTYPE:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd AUTHTYPE"));
	    if (cilen < CILEN_SHORT ||
		!(ao->neg_upap || ao->neg_chap)) {
		orc = CONFREJ;
		if (!ao->neg_upap && !ao->neg_chap)
		    LCPDEBUG((LOG_INFO, " we're not willing to authenticate"));
		else
		    LCPDEBUG((LOG_INFO, " cilen is too short!"));
		break;
	    }
	    GETSHORT(cishort, p);
	    LCPDEBUG((LOG_INFO, "(%x)", cishort));

	    /*
	     * Authtype must be UPAP or CHAP.
	     *
	     * Note: if both ao->neg_upap and ao->neg_chap are set,
	     * and the peer sends a Configure-Request with two
	     * authenticate-protocol requests, one for CHAP and one
	     * for UPAP, then we will reject the second request.
	     * Whether we end up doing CHAP or UPAP depends then on
	     * the ordering of the CIs in the peer's Configure-Request.
	     */

	    if (cishort == UPAP) {
		if (ho->neg_chap ||	/* we've already accepted CHAP */
		    cilen != CILEN_SHORT) {
		    LCPDEBUG((LOG_WARNING,
			      "lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
		    orc = CONFREJ;
		    break;
		}
		if (!ao->neg_upap) {	/* we don't want to do PAP */
		    orc = CONFNAK;	/* NAK it and suggest CHAP */
		    PUTCHAR(CI_AUTHTYPE, nakp);
		    PUTCHAR(CILEN_CHAP, nakp);
		    PUTSHORT(CHAP, nakp);
		    PUTCHAR(ao->chap_mdtype, nakp);
		    break;
		}
		ho->neg_upap = 1;
		break;
	    }
	    if (cishort == CHAP) {
		if (ho->neg_upap ||	/* we've already accepted PAP */
		    cilen != CILEN_CHAP) {
		    LCPDEBUG((LOG_INFO,
			      "lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
		    orc = CONFREJ;
		    break;
		}
		if (!ao->neg_chap) {	/* we don't want to do CHAP */
		    orc = CONFNAK;	/* NAK it and suggest PAP */
		    PUTCHAR(CI_AUTHTYPE, nakp);
		    PUTCHAR(CILEN_SHORT, nakp);
		    PUTSHORT(UPAP, nakp);
		    break;
		}
		GETCHAR(cichar, p);	/* get digest type*/
		if (cichar != (u_char)ao->chap_mdtype) {
		    orc = CONFNAK;
		    PUTCHAR(CI_AUTHTYPE, nakp);
		    PUTCHAR(CILEN_CHAP, nakp);
		    PUTSHORT(CHAP, nakp);
		    PUTCHAR(ao->chap_mdtype, nakp);
		    break;
		}
		ho->chap_mdtype = cichar; /* save md type */
		ho->neg_chap = 1;
		break;
	    }

	    /*
	     * We don't recognize the protocol they're asking for.
	     * Nak it with something we're willing to do.
	     * (At this point we know ao->neg_upap || ao->neg_chap.)
	     */
	    orc = CONFNAK;
	    PUTCHAR(CI_AUTHTYPE, nakp);
	    if (ao->neg_chap) {
		PUTCHAR(CILEN_CHAP, nakp);
		PUTSHORT(CHAP, nakp);
		PUTCHAR(ao->chap_mdtype, nakp);
	    } else {
		PUTCHAR(CILEN_SHORT, nakp);
		PUTSHORT(UPAP, nakp);
	    }
	    break;
            
	case CI_QUALITY:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd QUALITY"));
	    if (!ao->neg_lqr ||
		cilen != CILEN_LQR) {
		orc = CONFREJ;
		break;
	    }

	    GETSHORT(cishort, p);
	    GETLONG(cilong, p);
	    LCPDEBUG((LOG_INFO, "(%x %lx)", cishort, cilong));

	    /*
	     * Check the protocol and the reporting period.
	     * XXX When should we Nak this, and what with?
	     */
	    if (cishort != LQR) {
		orc = CONFNAK;
		PUTCHAR(CI_QUALITY, nakp);
		PUTCHAR(CILEN_LQR, nakp);
		PUTSHORT(LQR, nakp);
		PUTLONG(ao->lqr_period, nakp);
		break;
	    }
	    break;

	case CI_MAGICNUMBER:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MAGICNUMBER"));
	    if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
		cilen != CILEN_LONG) {
		orc = CONFREJ;
		break;
	    }
	    GETLONG(cilong, p);
	    LCPDEBUG((LOG_INFO, "(%lx)", cilong));

	    /*
	     * He must have a different magic number.
	     */
	    if (go->neg_magicnumber &&
		cilong == go->magicnumber) {
		orc = CONFNAK;
		cilong = magic();	/* Don't put magic() inside macro! */
		orc = CONFNAK;
		PUTCHAR(CI_MAGICNUMBER, nakp);
		PUTCHAR(CILEN_LONG, nakp);
		PUTLONG(cilong, nakp);
		break;
	    }
	    ho->neg_magicnumber = 1;
	    ho->magicnumber = cilong;
	    break;


	case CI_PCOMPRESSION:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd PCOMPRESSION"));
	    if (!ao->neg_pcompression ||
		cilen != CILEN_VOID) {
		orc = CONFREJ;
		break;
	    }
	    ho->neg_pcompression = 1;
	    break;

	case CI_ACCOMPRESSION:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ACCOMPRESSION"));
	    if (!ao->neg_accompression ||
		cilen != CILEN_VOID) {
		orc = CONFREJ;
		break;
	    }
	    ho->neg_accompression = 1;
	    break;

	default:
	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd unknown option %d",
		      citype));
	    orc = CONFREJ;
	    break;
	}

endswitch:
	LCPDEBUG((LOG_INFO, " (%s)", CODENAME(orc)));
	if (orc == CONFACK &&		/* Good CI */
	    rc != CONFACK)		/*  but prior CI wasnt? */
	    continue;			/* Don't send this one */

	if (orc == CONFNAK) {		/* Nak this CI? */
	    if (reject_if_disagree	/* Getting fed up with sending NAKs? */
		&& citype != CI_MAGICNUMBER) {
		orc = CONFREJ;		/* Get tough if so */
	    } else {
		if (rc == CONFREJ)	/* Rejecting prior CI? */
		    continue;		/* Don't send this one */
		rc = CONFNAK;
	    }
	}
	if (orc == CONFREJ) {		/* Reject this CI */
	    rc = CONFREJ;
	    if (cip != rejp)		/* Need to move rejected CI? */
		BCOPY(cip, rejp, cilen); /* Move it */
	    INCPTR(cilen, rejp);	/* Update output pointer */
	}
    }

    /*
     * If we wanted to send additional NAKs (for unsent CIs), the
     * code would go here.  The extra NAKs would go at *nakp.
     * At present there are no cases where we want to ask the
     * peer to negotiate an option.
     */

    switch (rc) {
    case CONFACK:
	*lenp = next - inp;
	break;
    case CONFNAK:
	/*
	 * Copy the Nak'd options from the nak_buffer to the caller's buffer.
	 */
	*lenp = nakp - nak_buffer;
	BCOPY(nak_buffer, inp, *lenp);
	break;
    case CONFREJ:
	*lenp = rejp - inp;
	break;
    }

    LCPDEBUG((LOG_INFO, "lcp_reqci: returning CONF%s.", CODENAME(rc)));
    return (rc);			/* Return final code */
}


/*
 * lcp_up - LCP has come UP.
 *
 * Start UPAP, IPCP, etc.
 */
static void
lcp_up(f)
    fsm *f;
{
    lcp_options *wo = &ppp_if[f->unit]->lcp_wantoptions;
    lcp_options *ho = &ppp_if[f->unit]->lcp_hisoptions;
    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;
    lcp_options *ao = &ppp_if[f->unit]->lcp_allowoptions;

    if (!go->neg_magicnumber)
        go->magicnumber = 0;
    if (!ho->neg_magicnumber)
        ho->magicnumber = 0;

    /*
     * Set our MTU to the smaller of the MTU we wanted and
     * the MRU our peer wanted.  If we negotiated an MRU,
     * set our MRU to the larger of value we wanted and
     * the value we got in the negotiation.
     */
    ppp_send_config(f->unit,
                    MIN(ao->mru? ao->mru: MTU, (ho->neg_mru? ho->mru: MTU)),
		    (ho->neg_asyncmap? ho->asyncmap: 0xffffffff),
		    ho->neg_pcompression, ho->neg_accompression);
    /*
     * If the asyncmap hasn't been negotiated, we really should
     * set the receive asyncmap to ffffffff, but we set it to 0
     * for backwards contemptibility.
     */
    ppp_recv_config(f->unit, (go->neg_mru? MAX(wo->mru, go->mru): MTU),
                    (go->neg_asyncmap? go->asyncmap: 0x00000000),
                    go->neg_pcompression, go->neg_accompression);

    if (ho->neg_mru)
	ppp_if[f->unit]->peer_mru = ho->mru;

    ChapLowerUp(f->unit);	/* Enable CHAP */
    upap_lowerup(f->unit);	/* Enable UPAP */
    ipcp_lowerup(f->unit);	/* Enable IPCP */
    lcp_echo_lowerup(f->unit);  /* Enable echo messages */

    link_established(f->unit);
}


/*
 * lcp_down - LCP has gone DOWN.
 *
 * Alert other protocols.
 */
static void
lcp_down(f)
    fsm *f;
{
    lcp_echo_lowerdown(f->unit);
    ipcp_lowerdown(f->unit);
    ChapLowerDown(f->unit);
    upap_lowerdown(f->unit);

    sifdown(f->unit);
    ppp_send_config(f->unit, MTU, 0xffffffff, 0, 0);
    ppp_recv_config(f->unit, MTU, 0x00000000, 0, 0);
    ppp_if[f->unit]->peer_mru = MTU;

    link_down(f->unit);
}


/*
 * lcp_starting - LCP needs the lower layer up.
 */
static void
lcp_starting(f)
    fsm *f;
{
    link_required(f->unit);
}


/*
 * lcp_finished - LCP has finished with the lower layer.
 */
static void
lcp_finished(f)
    fsm *f;
{
    /* if passive or silent flags set and if lcp state is STOPPED or CLOSED 
     * then reopen the link for the next connection
     */
    if (((f->state == STOPPED) || (f->state == CLOSED)) && 
	(f->flags & OPT_RESTART))
	fsm_open (f); 
    else 
	link_terminated(f->unit);
}

/*
 * lcp_printpkt - print the contents of an LCP packet.
 */
char *lcp_codenames[] = {
    "ConfReq", "ConfAck", "ConfNak", "ConfRej",
    "TermReq", "TermAck", "CodeRej", "ProtRej",
    "EchoReq", "EchoRep", "DiscReq"
};

int
lcp_printpkt(p, plen, printer, arg)
    u_char *p;
    int plen;
    void (*printer) __ARGS((void *, char *, ...));
    void *arg;
{
    int code, id, len, olen;
    u_char *pstart, *optend;
    u_short cishort;
    u_long cilong;

    if (plen < HEADERLEN)
        return 0;
    pstart = p;
    GETCHAR(code, p);
    GETCHAR(id, p);
    GETSHORT(len, p);
    if (len < HEADERLEN || len > plen)
        return 0;

    if (code >= 1 && code <= sizeof(lcp_codenames) / sizeof(char *))
        printer(arg, " %s", lcp_codenames[code-1]);
    else
        printer(arg, " code=0x%x", code);
    printer(arg, " id=0x%x", id);
    len -= HEADERLEN;
    switch (code) {
    case CONFREQ:
    case CONFACK:
    case CONFNAK:
    case CONFREJ:
        /* print option list */
        while (len >= 2) {
            GETCHAR(code, p);
            GETCHAR(olen, p);
            p -= 2;
            if (olen < 2 || olen > len) {
                break;
            }
            printer(arg, " <");
            len -= olen;
            optend = p + olen;
            switch (code) {
            case CI_MRU:
                if (olen == CILEN_SHORT) {
                    p += 2;
                    GETSHORT(cishort, p);
                    printer(arg, "mru %d", cishort);
                }
                break;
            case CI_ASYNCMAP:
                if (olen == CILEN_LONG) {
                    p += 2;
                    GETLONG(cilong, p);
                    printer(arg, "asyncmap 0x%x", cilong);
                }
                break;
            case CI_AUTHTYPE:
                if (olen >= CILEN_SHORT) {
                    p += 2;
                    printer(arg, "auth ");
                    GETSHORT(cishort, p);
                    switch (cishort) {
                    case UPAP:
                        printer(arg, "upap");
                        break;
                    case CHAP:
                        printer(arg, "chap");
                        break;
                    default:
                        printer(arg, "0x%x", cishort);
                    }
                }
                break;
            case CI_QUALITY:
                if (olen >= CILEN_SHORT) {
                    p += 2;
                    printer(arg, "quality ");
                    GETSHORT(cishort, p);
                    switch (cishort) {
                    case LQR:
                        printer(arg, "lqr");
                        break;
                    default:
                        printer(arg, "0x%x", cishort);
                    }
                }
                break;
            case CI_MAGICNUMBER:
                if (olen == CILEN_LONG) {
                    p += 2;
                    GETLONG(cilong, p);
                    printer(arg, "magic 0x%x", cilong);
                }
                break;
            case CI_PCOMPRESSION:
                if (olen == CILEN_VOID) {
                    p += 2;
                    printer(arg, "pcomp");
                }
                break;
            case CI_ACCOMPRESSION:
                if (olen == CILEN_VOID) {
                    p += 2;
                    printer(arg, "accomp");
                }
                break;
            }
            while (p < optend) {
                GETCHAR(code, p);
                printer(arg, " %.2x", code);
            }
            printer(arg, ">");
        }
        break;
    }

    /* print the rest of the bytes in the packet */
    for (; len > 0; --len) {
        GETCHAR(code, p);
        printer(arg, " %.2x", code);
    }

    return p - pstart;
}

/*
 * Time to shut down the link because there is nothing out there.
 */

static
void LcpLinkFailure (f)
    fsm *f;
{
    if (f->state == OPENED) {
        syslog (LOG_NOTICE, "Excessive lack of response to LCP echo frames.");
        lcp_lowerdown(f->unit);         /* Reset connection */
	ppp_if[f->unit]->phase = PHASE_TERMINATE;
    }
}

/*
 * Timer expired for the LCP echo requests from this process.
 */

static void
LcpEchoCheck (f)
    fsm *f;
{
    u_long             delta;
#ifdef __linux__
    struct ppp_ddinfo  ddinfo;
    u_long             latest;
/*
 * Read the time since the last packet was received.
 */
    if (ioctl (fd, PPPIOCGTIME, &ddinfo) < 0) {
        syslog (LOG_ERR, "ioctl(PPPIOCGTIME): %m");
        die (1);
    }
/*
 * Choose the most recient frame received. It may be an IP or NON-IP frame.
 */
    latest = ddinfo.nip_rjiffies < ddinfo.ip_rjiffies ? ddinfo.nip_rjiffies
                                                      : ddinfo.ip_rjiffies;
/*
 * Compute the time since the last packet was received. If the timer
 *  has expired then send the echo request and reset the timer to maximum.
 */
    delta = (lcp_echo_interval * HZ) - latest;
    if (delta < HZ || latest < 0L) {
        LcpSendEchoRequest (f);
        delta = lcp_echo_interval * HZ;
    }
    delta /= HZ;

#else /* Other implementations do not have ability to find delta */
    LcpSendEchoRequest (f);
    delta = ppp_if[f->unit]->lcp_echo_interval;
#endif

/*
 * Start the timer for the next interval.
 */
    assert (ppp_if[f->unit]->lcp_echo_timer_running==0);
    PPP_TIMEOUT (LcpEchoTimeout, (caddr_t) f, delta);
    ppp_if[f->unit]->lcp_echo_timer_running = 1;
}

/*
 * LcpEchoTimeout - Timer expired on the LCP echo
 */

static void
LcpEchoTimeout (arg)
    caddr_t arg;
{
    fsm *f = (fsm *)arg;

    if (ppp_if[f->unit]->lcp_echo_timer_running != 0) {
        ppp_if[f->unit]->lcp_echo_timer_running = 0;
        LcpEchoCheck ((fsm *) arg);
    }
}

/*
 * LcpEchoReply - LCP has received a reply to the echo
 */

static void
lcp_received_echo_reply (f, id, inp, len)
    fsm *f;
    int id; u_char *inp; int len;
{
    u_long magic;

    /* Check the magic number - don't count replies from ourselves. */
#ifdef	notyet
    if (len < CILEN_LONG)
        return;
#endif	/* notyet */
    GETLONG(magic, inp);
    if (ppp_if[f->unit]->lcp_gotoptions.neg_magicnumber
        && magic == ppp_if[f->unit]->lcp_gotoptions.magicnumber)
        return;

    /* Reset the number of outstanding echo frames */
    ppp_if[f->unit]->lcp_echos_pending = 0;
}

/*
 * LcpSendEchoRequest - Send an echo request frame to the peer
 */

static void
LcpSendEchoRequest (f)
    fsm *f;
{
    u_long lcp_magic;
    u_char pkt[4], *pktp;

/*
 * Detect the failure of the peer at this point.
 */
    if (ppp_if[f->unit]->lcp_echo_fails != 0) {
        if (ppp_if[f->unit]->lcp_echos_pending++ >= ppp_if[f->unit]->lcp_echo_fails) {
            LcpLinkFailure(f);
            ppp_if[f->unit]->lcp_echos_pending = 0;
	    die(f->unit, 1);
        }
    }
/*
 * Make and send the echo request frame.
 */
    if (f->state == OPENED) {
        lcp_magic = ppp_if[f->unit]->lcp_gotoptions.neg_magicnumber
                    ? ppp_if[f->unit]->lcp_gotoptions.magicnumber
                    : 0L;
        pktp = pkt;
        PUTLONG(lcp_magic, pktp);

        fsm_sdata(f, ECHOREQ,
                  ppp_if[f->unit]->lcp_echo_number++ & 0xFF, pkt, pktp - pkt);
    }
}

/*
 * lcp_echo_lowerup - Start the timer for the LCP frame
 */

static void
lcp_echo_lowerup (unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->lcp_fsm;

    /* Clear the parameters for generating echo frames */
    ppp_if[unit]->lcp_echos_pending      = 0;
    ppp_if[unit]->lcp_echo_number        = 0;
    ppp_if[unit]->lcp_echo_timer_running = 0;

    /* If a timeout interval is specified then start the timer */
    if (ppp_if[unit]->lcp_echo_interval != 0)
        LcpEchoCheck (f);
}

/*
 * lcp_echo_lowerdown - Stop the timer for the LCP frame
 */

static void
lcp_echo_lowerdown (unit)
    int unit;
{
    fsm *f = &ppp_if[unit]->lcp_fsm;

    if (ppp_if[unit]->lcp_echo_timer_running != 0) {
        PPP_UNTIMEOUT (LcpEchoTimeout, (caddr_t) f);
        ppp_if[unit]->lcp_echo_timer_running = 0;
    }
}