Initial revision

1 files changed, 1644 insertions, 0 deletions

diff --git a/usr.sbin/pppd/lcp.c b/usr.sbin/pppd/lcp.c
new file mode 100644
index 0000000..2581518
--- /dev/null
+++ b/usr.sbin/pppd/lcp.c
@@ -0,0 +1,1644 @@
+/*
+ * lcp.c - PPP Link Control Protocol.
+ *
+ * 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.
+ */
+
+#ifndef lint
+static char rcsid[] = "$Id: lcp.c,v 1.8 1994/05/30 02:38:49 paulus Exp $";
+#endif
+
+/*
+ * TODO:
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <syslog.h>
+#include <assert.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+
+#include "pppd.h"
+#include "ppp.h"
+#include "fsm.h"
+#include "lcp.h"
+#include "magic.h"
+#include "chap.h"
+#include "upap.h"
+#include "ipcp.h"
+
+#ifdef _linux_		/* Needs ppp ioctls */
+#include <linux/ppp.h>
+#endif
+
+/* global vars */
+fsm lcp_fsm[NPPP];			/* LCP fsm structure (global)*/
+lcp_options lcp_wantoptions[NPPP];	/* Options that we want to request */
+lcp_options lcp_gotoptions[NPPP];	/* Options that peer ack'd */
+lcp_options lcp_allowoptions[NPPP];	/* Options we allow peer to request */
+lcp_options lcp_hisoptions[NPPP];	/* Options that we ack'd */
+u_long xmit_accm[NPPP][8];		/* extended transmit ACCM */
+
+static u_long lcp_echos_pending = 0;    /* Number of outstanding echo msgs */
+static u_long lcp_echo_number   = 0;    /* ID number of next echo frame */
+static u_long lcp_echo_timer_running = 0;  /* TRUE if a timer is running */
+
+u_long lcp_echo_interval = 0;
+u_long lcp_echo_fails = 0;
+
+/*
+ * 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")
+
+
+/*
+ * lcp_init - Initialize LCP.
+ */
+void
+lcp_init(unit)
+    int unit;
+{
+    fsm *f = &lcp_fsm[unit];
+    lcp_options *wo = &lcp_wantoptions[unit];
+    lcp_options *ao = &lcp_allowoptions[unit];
+
+    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 */
+
+    memset(xmit_accm[unit], 0, sizeof(xmit_accm[0]));
+    xmit_accm[unit][3] = 0x60000000;
+}
+
+
+/*
+ * lcp_open - LCP is allowed to come up.
+ */
+void
+lcp_open(unit)
+    int unit;
+{
+    fsm *f = &lcp_fsm[unit];
+    lcp_options *wo = &lcp_wantoptions[unit];
+
+    f->flags = 0;
+    if (wo->passive)
+	f->flags |= OPT_PASSIVE;
+    if (wo->silent)
+	f->flags |= OPT_SILENT;
+    fsm_open(f);
+}
+
+
+/*
+ * lcp_close - Take LCP down.
+ */
+void
+lcp_close(unit)
+    int unit;
+{
+    fsm *f = &lcp_fsm[unit];
+
+    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(&lcp_fsm[unit]);
+}
+
+
+/*
+ * lcp_lowerup - The lower layer is up.
+ */
+void
+lcp_lowerup(unit)
+    int unit;
+{
+    sifdown(unit);
+    ppp_set_xaccm(unit, xmit_accm[unit]);
+    ppp_send_config(unit, MTU, 0xffffffff, 0, 0);
+    ppp_recv_config(unit, MTU, 0x00000000, 0, 0);
+    peer_mru[unit] = MTU;
+    lcp_allowoptions[unit].asyncmap = xmit_accm[unit][0];
+
+    fsm_lowerup(&lcp_fsm[unit]);
+}
+
+
+/*
+ * lcp_lowerdown - The lower layer is down.
+ */
+void
+lcp_lowerdown(unit)
+    int unit;
+{
+    fsm_lowerdown(&lcp_fsm[unit]);
+}
+
+
+/*
+ * lcp_input - Input LCP packet.
+ */
+void
+lcp_input(unit, p, len)
+    int unit;
+    u_char *p;
+    int len;
+{
+    fsm_input(&lcp_fsm[unit], 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(lcp_gotoptions[f->unit].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(&lcp_fsm[unit]);
+}
+
+
+/*
+ * 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(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
+	      p, len);
+}
+
+
+/*
+ * lcp_resetci - Reset our CI.
+ */
+static void
+  lcp_resetci(f)
+fsm *f;
+{
+    lcp_wantoptions[f->unit].magicnumber = magic();
+    lcp_wantoptions[f->unit].numloops = 0;
+    lcp_gotoptions[f->unit] = lcp_wantoptions[f->unit];
+    peer_mru[f->unit] = MTU;
+}
+
+
+/*
+ * lcp_cilen - Return length of our CI.
+ */
+static int
+lcp_cilen(f)
+    fsm *f;
+{
+    lcp_options *go = &lcp_gotoptions[f->unit];
+
+#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 = &lcp_gotoptions[f->unit];
+    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 = &lcp_gotoptions[f->unit];
+    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 != opt) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != 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 != opt) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != val) \
+	    goto bad; \
+	GETCHAR(cichar, p); \
+	if (cichar != 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 != opt) \
+	    goto bad; \
+	GETLONG(cilong, p); \
+	if (cilong != 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 != opt) \
+	    goto bad; \
+	GETSHORT(cishort, p); \
+	if (cishort != LQR) \
+	    goto bad; \
+	GETLONG(cilong, p); \
+	if (cilong != 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 = &lcp_gotoptions[f->unit];
+    lcp_options *wo = &lcp_wantoptions[f->unit];
+    u_char cilen, citype, cichar, *next;
+    u_short cishort;
+    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(&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 = &lcp_gotoptions[f->unit];
+    u_char cichar;
+    u_short cishort;
+    u_long cilong;
+    u_char *start = p;
+    int plen = len;
+    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 != 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 != val || cichar != 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 != 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 = &lcp_gotoptions[f->unit];
+    lcp_options *ho = &lcp_hisoptions[f->unit];
+    lcp_options *ao = &lcp_allowoptions[f->unit];
+    u_char *cip, *next;		/* Pointer to current and next CIs */
+    u_char cilen, citype, 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 *ucp = inp;		/* Pointer to current output char */
+    int l = *lenp;		/* Length left */
+
+    /*
+     * Reset all his options.
+     */
+    BZERO(ho, sizeof(*ho));
+
+    /*
+     * Process all his options.
+     */
+    next = 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;
+		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 (!ao->neg_upap ||	/* we don't want to do PAP */
+		    ho->neg_chap ||	/* or we've already accepted CHAP */
+		    cilen != CILEN_SHORT) {
+		    LCPDEBUG((LOG_WARNING,
+			      "lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));
+		    orc = CONFREJ;
+		    break;
+		}
+		ho->neg_upap = 1;
+		break;
+	    }
+	    if (cishort == CHAP) {
+		if (!ao->neg_chap ||	/* we don't want to do CHAP */
+		    ho->neg_upap ||	/* or we've already accepted UPAP */
+		    cilen != CILEN_CHAP) {
+		    LCPDEBUG((LOG_INFO,
+			      "lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));
+		    orc = CONFREJ;
+		    break;
+		}
+		GETCHAR(cichar, p);	/* get digest type*/
+		if (cichar != ao->chap_mdtype) {
+		    orc = CONFNAK;
+		    if( !reject_if_disagree ){
+			DECPTR(sizeof (u_char), p);
+			PUTCHAR(ao->chap_mdtype, p);
+		    }
+		    break;
+		}
+		ho->chap_mdtype = cichar; /* save md type */
+		ho->neg_chap = 1;
+		break;
+	    }
+
+	    /*
+	     * We don't recognize the protocol they're asking for.
+	     * Reject it.
+	     */
+	    orc = CONFREJ;
+	    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));
+	    if (cishort != LQR) {
+		orc = CONFREJ;
+		break;
+	    }
+
+	    /*
+	     * Check the reporting period.
+	     * XXX When should we Nak this, and what with?
+	     */
+	    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;
+		DECPTR(sizeof (long), p);
+		cilong = magic();	/* Don't put magic() inside macro! */
+		PUTLONG(cilong, p);
+		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? */
+		orc = CONFREJ;		/* Get tough if so */
+	    else {
+		if (rc == CONFREJ)	/* Rejecting prior CI? */
+		    continue;		/* Don't send this one */
+		if (rc == CONFACK) {	/* Ack'd all prior CIs? */
+		    rc = CONFNAK;	/* Not anymore... */
+		    ucp = inp;		/* Backup */
+		}
+	    }
+	}
+	if (orc == CONFREJ &&		/* Reject this CI */
+	    rc != CONFREJ) {		/*  but no prior ones? */
+	    rc = CONFREJ;
+	    ucp = inp;			/* Backup */
+	}
+	if (ucp != cip)			/* Need to move CI? */
+	    BCOPY(cip, ucp, cilen);	/* Move it */
+	INCPTR(cilen, ucp);		/* Update output pointer */
+    }
+
+    /*
+     * If we wanted to send additional NAKs (for unsent CIs), the
+     * code would go here.  This must be done with care since it might
+     * require a longer packet than we received.  At present there
+     * are no cases where we want to ask the peer to negotiate an option.
+     */
+
+    *lenp = ucp - inp;			/* Compute output length */
+    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 = &lcp_wantoptions[f->unit];
+    lcp_options *ho = &lcp_hisoptions[f->unit];
+    lcp_options *go = &lcp_gotoptions[f->unit];
+    lcp_options *ao = &lcp_allowoptions[f->unit];
+
+    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, (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)
+	peer_mru[f->unit] = 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);
+    peer_mru[f->unit] = 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;
+{
+    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 */
+    }
+}
+
+/*
+ * 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 = lcp_echo_interval;
+#endif
+
+/*
+ * Start the timer for the next interval.
+ */
+    assert (lcp_echo_timer_running==0);
+    TIMEOUT (LcpEchoTimeout, (caddr_t) f, delta);
+    lcp_echo_timer_running = 1;
+}
+
+/*
+ * LcpEchoTimeout - Timer expired on the LCP echo
+ */
+
+static void
+LcpEchoTimeout (arg)
+    caddr_t arg;
+{
+    if (lcp_echo_timer_running != 0) {
+        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. */
+    if (len < CILEN_LONG)
+	return;
+    GETLONG(magic, inp);
+    if (lcp_gotoptions[f->unit].neg_magicnumber
+	&& magic == lcp_gotoptions[f->unit].magicnumber)
+	return;
+
+    /* Reset the number of outstanding echo frames */
+    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 (lcp_echo_fails != 0) {
+        if (lcp_echos_pending++ >= lcp_echo_fails) {
+            LcpLinkFailure(f);
+	    lcp_echos_pending = 0;
+	}
+    }
+/*
+ * Make and send the echo request frame.
+ */
+    if (f->state == OPENED) {
+        lcp_magic = lcp_gotoptions[f->unit].neg_magicnumber
+	            ? lcp_gotoptions[f->unit].magicnumber
+	            : 0L;
+	pktp = pkt;
+	PUTLONG(lcp_magic, pktp);
+      
+        fsm_sdata(f, ECHOREQ,
+		  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 = &lcp_fsm[unit];
+
+    /* Clear the parameters for generating echo frames */
+    lcp_echos_pending      = 0;
+    lcp_echo_number        = 0;
+    lcp_echo_timer_running = 0;
+  
+    /* If a timeout interval is specified then start the timer */
+    if (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 = &lcp_fsm[unit];
+
+    if (lcp_echo_timer_running != 0) {
+        UNTIMEOUT (LcpEchoTimeout, (caddr_t) f);
+        lcp_echo_timer_running = 0;
+    }
+}