initial commit of lk (little kernel) project
diff --git a/lib/lwip/src/netif/ppp/lcp.c b/lib/lwip/src/netif/ppp/lcp.c
new file mode 100644
index 0000000..6a988d6
--- /dev/null
+++ b/lib/lwip/src/netif/ppp/lcp.c
@@ -0,0 +1,1991 @@
+/*****************************************************************************
+* lcp.c - Network Link Control Protocol program file.
+*
+* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
+* portions Copyright (c) 1997 by Global Election Systems Inc.
+*
+* The authors hereby grant permission to use, copy, modify, distribute,
+* and license this software and its documentation for any purpose, provided
+* that existing copyright notices are retained in all copies and that this
+* notice and the following disclaimer are included verbatim in any 
+* distributions. No written agreement, license, or royalty fee is required
+* for any of the authorized uses.
+*
+* THIS SOFTWARE IS PROVIDED BY THE 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 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.
+*
+******************************************************************************
+* REVISION HISTORY
+*
+* 03-01-01 Marc Boucher <marc@mbsi.ca>
+*   Ported to lwIP.
+* 97-12-01 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
+*	Original.
+*****************************************************************************/
+
+/*
+ * 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.
+ */
+ 
+#include <string.h>
+ 
+#include "ppp.h"
+#if PPP_SUPPORT > 0
+#include "fsm.h"
+#include "chap.h"
+#include "magic.h"
+#include "auth.h"
+#include "lcp.h"
+#include "pppdebug.h"
+
+
+/*************************/
+/*** LOCAL DEFINITIONS ***/
+/*************************/
+/*
+ * Length of each type of configuration option (in octets)
+ */
+#define CILEN_VOID	2
+#define CILEN_CHAR	3
+#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 CILEN_CBCP	3
+
+
+/***********************************/
+/*** LOCAL FUNCTION DECLARATIONS ***/
+/***********************************/
+/*
+ * Callbacks for fsm code.  (CI = Configuration Information)
+ */
+static void lcp_resetci (fsm*);	        /* Reset our CI */
+static int  lcp_cilen (fsm*);		        /* Return length of our CI */
+static void lcp_addci (fsm*, u_char*, int*);       /* Add our CI to pkt */
+static int  lcp_ackci (fsm*, u_char*, int);/* Peer ack'd our CI */
+static int  lcp_nakci (fsm*, u_char*, int);/* Peer nak'd our CI */
+static int  lcp_rejci (fsm*, u_char*, int);/* Peer rej'd our CI */
+static int  lcp_reqci (fsm*, u_char*, int*, int);  /* Rcv peer CI */
+static void lcp_up (fsm*);		            /* We're UP */
+static void lcp_down (fsm*);	    	    /* We're DOWN */
+static void lcp_starting (fsm*);   	    /* We need lower layer up */
+static void lcp_finished (fsm*);	        /* We need lower layer down */
+static int  lcp_extcode (fsm*, int, u_char, u_char*, int);
+
+static void lcp_rprotrej (fsm*, u_char*, int);
+
+/*
+ * routines to send LCP echos to peer
+ */
+static void lcp_echo_lowerup (int);
+static void lcp_echo_lowerdown (int);
+static void LcpEchoTimeout (void*);
+static void lcp_received_echo_reply (fsm*, int, u_char*, int);
+static void LcpSendEchoRequest (fsm*);
+static void LcpLinkFailure (fsm*);
+static void LcpEchoCheck (fsm*);
+
+/*
+ * Protocol entry points.
+ * Some of these are called directly.
+ */
+static void lcp_input (int, u_char *, int);
+static void lcp_protrej (int);
+
+#define CODENAME(x)	((x) == CONFACK ? "ACK" : \
+			 (x) == CONFNAK ? "NAK" : "REJ")
+
+
+/******************************/
+/*** PUBLIC DATA STRUCTURES ***/
+/******************************/
+/* global vars */
+LinkPhase lcp_phase[NUM_PPP];			/* Phase of link session (RFC 1661) */
+lcp_options lcp_wantoptions[NUM_PPP];	/* Options that we want to request */
+lcp_options lcp_gotoptions[NUM_PPP];	/* Options that peer ack'd */
+lcp_options lcp_allowoptions[NUM_PPP];	/* Options we allow peer to request */
+lcp_options lcp_hisoptions[NUM_PPP];	/* Options that we ack'd */
+ext_accm xmit_accm[NUM_PPP];			/* extended transmit ACCM */
+
+
+
+/*****************************/
+/*** LOCAL DATA STRUCTURES ***/
+/*****************************/
+static fsm lcp_fsm[NUM_PPP];			/* LCP fsm structure (global)*/
+static u_int	 lcp_echo_interval = LCP_ECHOINTERVAL; /* Interval between LCP echo-requests */
+static u_int	 lcp_echo_fails = LCP_MAXECHOFAILS; /* Tolerance to unanswered echo-requests */
+static u32_t lcp_echos_pending = 0;	/* Number of outstanding echo msgs */
+static u32_t lcp_echo_number   = 0;	/* ID number of next echo frame */
+static u32_t lcp_echo_timer_running = 0;  /* TRUE if a timer is running */
+
+static u_char nak_buffer[PPP_MRU];	/* where we construct a nak packet */
+
+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 */
+};
+
+struct protent lcp_protent = {
+    PPP_LCP,
+    lcp_init,
+    lcp_input,
+    lcp_protrej,
+    lcp_lowerup,
+    lcp_lowerdown,
+    lcp_open,
+    lcp_close,
+#if 0
+    lcp_printpkt,
+    NULL,
+#endif
+    1,
+    "LCP",
+#if 0
+    NULL,
+    NULL,
+    NULL
+#endif
+};
+
+int lcp_loopbackfail = DEFLOOPBACKFAIL;
+
+
+
+/***********************************/
+/*** PUBLIC FUNCTION DEFINITIONS ***/
+/***********************************/
+/*
+ * lcp_init - Initialize LCP.
+ */
+void lcp_init(int unit)
+{
+	fsm *f = &lcp_fsm[unit];
+	lcp_options *wo = &lcp_wantoptions[unit];
+	lcp_options *ao = &lcp_allowoptions[unit];
+	
+	f->unit = unit;
+	f->protocol = PPP_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 = PPP_DEFMRU;
+	wo->neg_asyncmap = 1;
+	wo->asyncmap = 0x00000000l;	/* Assume don't need to escape any ctl chars. */
+	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 */
+	wo->neg_cbcp = 0;
+	
+	ao->neg_mru = 1;
+	ao->mru = PPP_MAXMRU;
+	ao->neg_asyncmap = 1;
+	ao->asyncmap = 0x00000000l;	/* Assume don't need to escape any ctl chars. */
+	ao->neg_chap = (CHAP_SUPPORT != 0);
+	ao->chap_mdtype = CHAP_DIGEST_MD5;
+	ao->neg_upap = (PAP_SUPPORT != 0);
+	ao->neg_magicnumber = 1;
+	ao->neg_pcompression = 1;
+	ao->neg_accompression = 1;
+	ao->neg_lqr = 0;			/* no LQR implementation yet */
+	ao->neg_cbcp = (CBCP_SUPPORT != 0);
+
+	/* 
+	 * Set transmit escape for the flag and escape characters plus anything
+	 * set for the allowable options.
+	 */
+	memset(xmit_accm[unit], 0, sizeof(xmit_accm[0]));
+	xmit_accm[unit][15] = 0x60;
+	xmit_accm[unit][0] = (u_char)(ao->asyncmap & 0xFF);
+	xmit_accm[unit][1] = (u_char)((ao->asyncmap >> 8) & 0xFF);
+	xmit_accm[unit][2] = (u_char)((ao->asyncmap >> 16) & 0xFF);
+	xmit_accm[unit][3] = (u_char)((ao->asyncmap >> 24) & 0xFF);
+	LCPDEBUG((LOG_INFO, "lcp_init: xmit_accm=%X %X %X %X\n",
+				xmit_accm[unit][0],
+				xmit_accm[unit][1],
+				xmit_accm[unit][2],
+				xmit_accm[unit][3]));
+	
+	lcp_phase[unit] = PHASE_INITIALIZE;
+}
+
+
+/*
+ * lcp_open - LCP is allowed to come up.
+ */
+void lcp_open(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_phase[unit] = PHASE_ESTABLISH; 
+}
+
+
+/*
+ * lcp_close - Take LCP down.
+ */
+void lcp_close(int unit, char *reason)
+{
+	fsm *f = &lcp_fsm[unit];
+	
+	if (lcp_phase[unit] != PHASE_DEAD)
+		lcp_phase[unit] = PHASE_TERMINATE;
+	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 an
+		 * lcp_close() in passive/silent mode when a connection hasn't
+		 * been established.
+		 */
+		f->state = CLOSED;
+		lcp_finished(f);
+	}
+	else
+		fsm_close(&lcp_fsm[unit], reason);
+}
+
+
+/*
+ * lcp_lowerup - The lower layer is up.
+ */
+void lcp_lowerup(int unit)
+{
+	lcp_options *wo = &lcp_wantoptions[unit];
+	
+	/*
+	* Don't use A/C or protocol compression on transmission,
+	* but accept A/C and protocol compressed packets
+	* if we are going to ask for A/C and protocol compression.
+	*/
+	ppp_set_xaccm(unit, &xmit_accm[unit]);
+	ppp_send_config(unit, PPP_MRU, 0xffffffffl, 0, 0);
+	ppp_recv_config(unit, PPP_MRU, 0x00000000l,
+					wo->neg_pcompression, wo->neg_accompression);
+	peer_mru[unit] = PPP_MRU;
+	lcp_allowoptions[unit].asyncmap 
+		= (u_long)xmit_accm[unit][0]
+			| ((u_long)xmit_accm[unit][1] << 8)
+			| ((u_long)xmit_accm[unit][2] << 16)
+			| ((u_long)xmit_accm[unit][3] << 24);
+	LCPDEBUG((LOG_INFO, "lcp_lowerup: asyncmap=%X %X %X %X\n",
+				xmit_accm[unit][3],
+				xmit_accm[unit][2],
+				xmit_accm[unit][1],
+				xmit_accm[unit][0]));
+	
+	fsm_lowerup(&lcp_fsm[unit]);
+}
+
+
+/*
+ * lcp_lowerdown - The lower layer is down.
+ */
+void lcp_lowerdown(int unit)
+{
+	fsm_lowerdown(&lcp_fsm[unit]);
+}
+
+/*
+ * lcp_sprotrej - Send a Protocol-Reject for some protocol.
+ */
+void lcp_sprotrej(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.
+	*/
+
+	fsm_sdata(&lcp_fsm[unit], PROTREJ, ++lcp_fsm[unit].id,
+				p, len);
+}
+
+
+
+/**********************************/
+/*** LOCAL FUNCTION DEFINITIONS ***/
+/**********************************/
+/*
+ * lcp_input - Input LCP packet.
+ */
+static void lcp_input(int unit, u_char *p, int len)
+{
+	fsm *f = &lcp_fsm[unit];
+	
+	fsm_input(f, p, len);
+}
+
+
+/*
+ * lcp_extcode - Handle a LCP-specific code.
+ */
+static int lcp_extcode(fsm *f, int code, u_char 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\n", id));
+		magp = inp;
+		PUTLONG(lcp_gotoptions[f->unit].magicnumber, magp);
+		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(fsm *f, u_char *inp, int len)
+{
+	int i;
+	struct protent *protp;
+	u_short prot;
+	
+	if (len < sizeof (u_short)) {
+		LCPDEBUG((LOG_INFO,
+				"lcp_rprotrej: Rcvd short Protocol-Reject packet!\n"));
+		return;
+	}
+	
+	GETSHORT(prot, inp);
+	
+	LCPDEBUG((LOG_INFO,
+			"lcp_rprotrej: Rcvd Protocol-Reject packet for %x!\n",
+			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\n",
+				f->state));
+		return;
+	}
+	
+	/*
+	* Upcall the proper Protocol-Reject routine.
+	*/
+	for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i)
+		if (protp->protocol == prot && protp->enabled_flag) {
+			(*protp->protrej)(f->unit);
+			return;
+		}
+	
+	LCPDEBUG((LOG_WARNING, "Protocol-Reject for unsupported protocol 0x%x\n",
+			prot));
+}
+
+
+/*
+ * lcp_protrej - A Protocol-Reject was received.
+ */
+static void lcp_protrej(int unit)
+{
+	(void)unit;
+	/*
+	* Can't reject LCP!
+	*/
+	LCPDEBUG((LOG_WARNING,
+			"lcp_protrej: Received Protocol-Reject for LCP!\n"));
+	fsm_protreject(&lcp_fsm[unit]);
+}
+
+
+/*
+ * lcp_resetci - Reset our CI.
+ */
+static void lcp_resetci(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] = PPP_MRU;
+	auth_reset(f->unit);
+}
+
+
+/*
+ * lcp_cilen - Return length of our CI.
+ */
+static int lcp_cilen(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)
+#define LENCICBCP(neg)	((neg) ? CILEN_CBCP: 0)
+	/*
+	* NB: we only ask for one of CHAP and UPAP, even if we will
+	* accept either.
+	*/
+	return (LENCISHORT(go->neg_mru && go->mru != PPP_DEFMRU) +
+		LENCILONG(go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl) +
+		LENCICHAP(go->neg_chap) +
+		LENCISHORT(!go->neg_chap && go->neg_upap) +
+		LENCILQR(go->neg_lqr) +
+		LENCICBCP(go->neg_cbcp) +
+		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(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) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: opt=%d\n", opt)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_VOID, ucp); \
+	}
+#define ADDCISHORT(opt, neg, val) \
+	if (neg) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: INT opt=%d %X\n", opt, val)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_SHORT, ucp); \
+		PUTSHORT(val, ucp); \
+	}
+#define ADDCICHAP(opt, neg, val, digest) \
+	if (neg) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: CHAP opt=%d %X\n", opt, val)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_CHAP, ucp); \
+		PUTSHORT(val, ucp); \
+		PUTCHAR(digest, ucp); \
+	}
+#define ADDCILONG(opt, neg, val) \
+	if (neg) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: L opt=%d %lX\n", opt, val)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_LONG, ucp); \
+		PUTLONG(val, ucp); \
+	}
+#define ADDCILQR(opt, neg, val) \
+	if (neg) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: LQR opt=%d %lX\n", opt, val)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_LQR, ucp); \
+		PUTSHORT(PPP_LQR, ucp); \
+		PUTLONG(val, ucp); \
+	}
+#define ADDCICHAR(opt, neg, val) \
+	if (neg) { \
+	    LCPDEBUG((LOG_INFO, "lcp_addci: CHAR opt=%d %X '%z'\n", opt, val, val)); \
+		PUTCHAR(opt, ucp); \
+		PUTCHAR(CILEN_CHAR, ucp); \
+		PUTCHAR(val, ucp); \
+	}
+	
+	ADDCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
+	ADDCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl,
+			go->asyncmap);
+	ADDCICHAP(CI_AUTHTYPE, go->neg_chap, PPP_CHAP, go->chap_mdtype);
+	ADDCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
+	ADDCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
+	ADDCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
+	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 */
+		LCPDEBUG((LOG_ERR, "Bug in lcp_addci: wrong length\n"));
+	}
+}
+
+
+/*
+ * 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(fsm *f, u_char *p, int len)
+{
+	lcp_options *go = &lcp_gotoptions[f->unit];
+	u_char cilen, citype, cichar;
+	u_short cishort;
+	u32_t 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 ACKCICHAR(opt, neg, val) \
+	if (neg) { \
+		if ((len -= CILEN_CHAR) < 0) \
+			goto bad; \
+		GETCHAR(citype, p); \
+		GETCHAR(cilen, p); \
+		if (cilen != CILEN_CHAR || \
+				citype != opt) \
+			goto bad; \
+		GETCHAR(cichar, p); \
+		if (cichar != 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 != PPP_LQR) \
+			goto bad; \
+		GETLONG(cilong, p); \
+		if (cilong != val) \
+			goto bad; \
+	}
+	
+	ACKCISHORT(CI_MRU, go->neg_mru && go->mru != PPP_DEFMRU, go->mru);
+	ACKCILONG(CI_ASYNCMAP, go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl,
+			go->asyncmap);
+	ACKCICHAP(CI_AUTHTYPE, go->neg_chap, PPP_CHAP, go->chap_mdtype);
+	ACKCISHORT(CI_AUTHTYPE, !go->neg_chap && go->neg_upap, PPP_PAP);
+	ACKCILQR(CI_QUALITY, go->neg_lqr, go->lqr_period);
+	ACKCICHAR(CI_CALLBACK, go->neg_cbcp, CBCP_OPT);
+	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;
+	LCPDEBUG((LOG_INFO, "lcp_acki: Ack\n"));
+	return (1);
+bad:
+	LCPDEBUG((LOG_WARNING, "lcp_acki: received bad Ack!\n"));
+	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(fsm *f, u_char *p, int len)
+{
+	lcp_options *go = &lcp_gotoptions[f->unit];
+	lcp_options *wo = &lcp_wantoptions[f->unit];
+	u_char citype, cichar, *next;
+	u_short cishort;
+	u32_t cilong;
+	lcp_options no;		/* options we've seen Naks for */
+	lcp_options try;		/* options to request next time */
+	int looped_back = 0;
+	int cilen;
+	
+	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 NAKCICHAR(opt, neg, code) \
+	if (go->neg && \
+			len >= CILEN_CHAR && \
+			p[1] == CILEN_CHAR && \
+			p[0] == opt) { \
+		len -= CILEN_CHAR; \
+		INCPTR(2, 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.
+	*/
+	if (go->neg_mru && go->mru != PPP_DEFMRU) {
+		NAKCISHORT(CI_MRU, neg_mru,
+			if (cishort <= wo->mru || cishort < PPP_DEFMRU)
+				try.mru = cishort;
+		);
+	}
+	
+	/*
+	* Add any characters they want to our (receive-side) asyncmap.
+	*/
+	if (go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl) {
+		NAKCILONG(CI_ASYNCMAP, neg_asyncmap,
+			try.asyncmap = go->asyncmap | cilong;
+		);
+	}
+	
+	/*
+	* If they've nak'd our authentication-protocol, check whether
+	* they are proposing a different protocol, or a different
+	* hash algorithm for CHAP.
+	*/
+	if ((go->neg_chap || go->neg_upap)
+			&& len >= CILEN_SHORT
+			&& p[0] == CI_AUTHTYPE && p[1] >= CILEN_SHORT && p[1] <= len) {
+		cilen = p[1];
+	len -= cilen;
+	no.neg_chap = go->neg_chap;
+	no.neg_upap = go->neg_upap;
+	INCPTR(2, p);
+	GETSHORT(cishort, p);
+	if (cishort == PPP_PAP && cilen == CILEN_SHORT) {
+		/*
+		 * If we were asking for CHAP, they obviously don't want to do it.
+		 * If we weren't asking for CHAP, then we were asking for PAP,
+		 * in which case this Nak is bad.
+		 */
+		if (!go->neg_chap)
+			goto bad;
+		try.neg_chap = 0;
+	
+	} else if (cishort == PPP_CHAP && cilen == CILEN_CHAP) {
+		GETCHAR(cichar, p);
+		if (go->neg_chap) {
+			/*
+			 * We were asking for CHAP/MD5; they must want a different
+			 * algorithm.  If they can't do MD5, we'll have to stop
+			 * asking for CHAP.
+			 */
+			if (cichar != go->chap_mdtype)
+				try.neg_chap = 0;
+		} else {
+			/*
+			 * Stop asking for PAP if we were asking for it.
+			 */
+			try.neg_upap = 0;
+		}
+	
+	} else {
+		/*
+		 * We don't recognize what they're suggesting.
+		 * Stop asking for what we were asking for.
+		 */
+		if (go->neg_chap)
+			try.neg_chap = 0;
+		else
+			try.neg_upap = 0;
+		p += cilen - CILEN_SHORT;
+	}
+	}
+	
+	/*
+	* 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 != PPP_LQR)
+			try.neg_lqr = 0;
+		else
+			try.lqr_period = cilong;
+	);
+	
+	/*
+	* Only implementing CBCP...not the rest of the callback options
+	*/
+	NAKCICHAR(CI_CALLBACK, neg_cbcp,
+		try.neg_cbcp = 0;
+	);
+	
+	/*
+	* Check for a looped-back line.
+	*/
+	NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,
+		try.magicnumber = magic();
+		looped_back = 1;
+	);
+	
+	/*
+	* Peer shouldn't send Nak for protocol compression or
+	* address/control compression requests; they should send
+	* a Reject instead.  If they send a Nak, treat it as a Reject.
+	*/
+	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.
+	* An option we don't recognize represents the peer asking to
+	* negotiate some option we don't support, so ignore it.
+	*/
+	while (len > CILEN_VOID) {
+		GETCHAR(citype, p);
+		GETCHAR(cilen, p);
+		if (cilen < CILEN_VOID || (len -= cilen) < 0)
+			goto bad;
+		next = p + cilen - 2;
+		
+		switch (citype) {
+		case CI_MRU:
+			if ((go->neg_mru && go->mru != PPP_DEFMRU)
+					|| no.neg_mru || cilen != CILEN_SHORT)
+				goto bad;
+			GETSHORT(cishort, p);
+			if (cishort < PPP_DEFMRU)
+				try.mru = cishort;
+			break;
+		case CI_ASYNCMAP:
+			if ((go->neg_asyncmap && go->asyncmap != 0xFFFFFFFFl)
+					|| 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;
+		}
+		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) {
+		if (looped_back) {
+			if (++try.numloops >= lcp_loopbackfail) {
+				LCPDEBUG((LOG_NOTICE, "Serial line is looped back.\n"));
+				lcp_close(f->unit, "Loopback detected");
+			}
+		} 
+		else
+			try.numloops = 0;
+		*go = try;
+	}
+	
+	return 1;
+	
+bad:
+	LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!\n"));
+	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(fsm *f, u_char *p, int len)
+{
+	lcp_options *go = &lcp_gotoptions[f->unit];
+	u_char cichar;
+	u_short cishort;
+	u32_t cilong;
+	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: void opt %d rejected\n", 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: short opt %d rejected\n", 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; \
+		try.neg_upap = 0; \
+		LCPDEBUG((LOG_INFO,"lcp_rejci: chap opt %d rejected\n", 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: long opt %d rejected\n", 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 != PPP_LQR || cilong != val) \
+			goto bad; \
+		try.neg = 0; \
+		LCPDEBUG((LOG_INFO,"lcp_rejci: LQR opt %d rejected\n", opt)); \
+	}
+#define REJCICBCP(opt, neg, val) \
+	if (go->neg && \
+			len >= CILEN_CBCP && \
+			p[1] == CILEN_CBCP && \
+			p[0] == opt) { \
+		len -= CILEN_CBCP; \
+		INCPTR(2, p); \
+		GETCHAR(cichar, p); \
+		/* Check rejected value. */ \
+		if (cichar != val) \
+			goto bad; \
+		try.neg = 0; \
+		LCPDEBUG((LOG_INFO,"lcp_rejci: Callback opt %d rejected\n", opt)); \
+	}
+	
+	REJCISHORT(CI_MRU, neg_mru, go->mru);
+	REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);
+	REJCICHAP(CI_AUTHTYPE, neg_chap, PPP_CHAP, go->chap_mdtype);
+	if (!go->neg_chap) {
+		REJCISHORT(CI_AUTHTYPE, neg_upap, PPP_PAP);
+	}
+	REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);
+	REJCICBCP(CI_CALLBACK, neg_cbcp, CBCP_OPT);
+	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!\n"));
+	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(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 */
+	int cilen, citype, cichar;	/* Parsed len, type, char value */
+	u_short cishort;			/* Parsed short value */
+	u32_t 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 */
+#if TRACELCP > 0
+	char traceBuf[80];
+	int traceNdx = 0;
+#endif
+	
+	/*
+	 * Reset all his options.
+	 */
+	BZERO(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!\n"));
+			orc = CONFREJ;		/* Reject bad CI */
+			cilen = l;			/* Reject till end of packet */
+			l = 0;			/* Don't loop again */
+			citype = 0;
+			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:
+			if (!ao->neg_mru) {		/* Allow option? */
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject MRU - not allowed\n"));
+				orc = CONFREJ;		/* Reject CI */
+				break;
+			} else if (cilen != CILEN_SHORT) {	/* Check CI length */
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject MRU - bad length\n"));
+				orc = CONFREJ;		/* Reject CI */
+				break;
+			}
+			GETSHORT(cishort, p);	/* Parse MRU */
+			
+			/*
+			 * 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 < PPP_MINMRU) {
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Nak - MRU too small\n"));
+				orc = CONFNAK;		/* Nak CI */
+				PUTCHAR(CI_MRU, nakp);
+				PUTCHAR(CILEN_SHORT, nakp);
+				PUTSHORT(PPP_MINMRU, nakp);	/* Give him a hint */
+				break;
+			}
+			ho->neg_mru = 1;		/* Remember he sent MRU */
+			ho->mru = cishort;		/* And remember value */
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " MRU %d", cishort);
+			traceNdx = strlen(traceBuf);
+#endif
+			break;
+		
+		case CI_ASYNCMAP:
+			if (!ao->neg_asyncmap) {
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject ASYNCMAP not allowed\n"));
+				orc = CONFREJ;
+				break;
+			} else if (cilen != CILEN_LONG) {
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject ASYNCMAP bad length\n"));
+				orc = CONFREJ;
+				break;
+			}
+			GETLONG(cilong, p);
+			
+			/*
+			 * Asyncmap must have set at least the bits
+			 * which are set in lcp_allowoptions[unit].asyncmap.
+			 */
+			if ((ao->asyncmap & ~cilong) != 0) {
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Nak ASYNCMAP %lX missing %lX\n", 
+							cilong, ao->asyncmap));
+				orc = CONFNAK;
+				PUTCHAR(CI_ASYNCMAP, nakp);
+				PUTCHAR(CILEN_LONG, nakp);
+				PUTLONG(ao->asyncmap | cilong, nakp);
+				break;
+			}
+			ho->neg_asyncmap = 1;
+			ho->asyncmap = cilong;
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " ASYNCMAP=%lX", cilong);
+			traceNdx = strlen(traceBuf);
+#endif
+			break;
+		
+		case CI_AUTHTYPE:
+			if (cilen < CILEN_SHORT) {
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject AUTHTYPE missing arg\n"));
+				orc = CONFREJ;
+				break;
+			} else if (!(ao->neg_upap || ao->neg_chap)) {
+				/*
+				 * Reject the option if we're not willing to authenticate.
+				 */
+				LCPDEBUG((LOG_INFO, "lcp_reqci: Reject AUTHTYPE not allowed\n"));
+				orc = CONFREJ;
+				break;
+			}
+			GETSHORT(cishort, p);
+			
+			/*
+			 * 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 == PPP_PAP) {
+				if (ho->neg_chap) {	/* we've already accepted CHAP */
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE PAP already accepted\n"));
+					orc = CONFREJ;
+					break;
+				} else if (cilen != CILEN_SHORT) {
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE PAP bad len\n"));
+					orc = CONFREJ;
+					break;
+				}
+				if (!ao->neg_upap) {	/* we don't want to do PAP */
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE PAP not allowed\n"));
+					orc = CONFNAK;	/* NAK it and suggest CHAP */
+					PUTCHAR(CI_AUTHTYPE, nakp);
+					PUTCHAR(CILEN_CHAP, nakp);
+					PUTSHORT(PPP_CHAP, nakp);
+					PUTCHAR(ao->chap_mdtype, nakp);
+					break;
+				}
+				ho->neg_upap = 1;
+#if TRACELCP > 0
+				snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " PAP (%X)", cishort);
+				traceNdx = strlen(traceBuf);
+#endif
+				break;
+			}
+			if (cishort == PPP_CHAP) {
+				if (ho->neg_upap) {	/* we've already accepted PAP */
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE CHAP accepted PAP\n"));
+					orc = CONFREJ;
+					break;
+				} else if (cilen != CILEN_CHAP) {
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Reject AUTHTYPE CHAP bad len\n"));
+					orc = CONFREJ;
+					break;
+				}
+				if (!ao->neg_chap) {	/* we don't want to do CHAP */
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE CHAP not allowed\n"));
+					orc = CONFNAK;	/* NAK it and suggest PAP */
+					PUTCHAR(CI_AUTHTYPE, nakp);
+					PUTCHAR(CILEN_SHORT, nakp);
+					PUTSHORT(PPP_PAP, nakp);
+					break;
+				}
+				GETCHAR(cichar, p);	/* get digest type*/
+				if (cichar != CHAP_DIGEST_MD5
+#ifdef CHAPMS
+						&& cichar != CHAP_MICROSOFT
+#endif
+				) {
+					LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE CHAP digest=%d\n", cichar));
+					orc = CONFNAK;
+					PUTCHAR(CI_AUTHTYPE, nakp);
+					PUTCHAR(CILEN_CHAP, nakp);
+					PUTSHORT(PPP_CHAP, nakp);
+					PUTCHAR(ao->chap_mdtype, nakp);
+					break;
+				}
+#if TRACELCP > 0
+				snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " CHAP %X,%d", cishort, cichar);
+				traceNdx = strlen(traceBuf);
+#endif
+				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) {
+				LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE %d req CHAP\n", cishort));
+				PUTCHAR(CILEN_CHAP, nakp);
+				PUTSHORT(PPP_CHAP, nakp);
+				PUTCHAR(ao->chap_mdtype, nakp);
+			} 
+			else {
+				LCPDEBUG((LOG_WARNING, "lcp_reqci: Nak AUTHTYPE %d req PAP\n", cishort));
+				PUTCHAR(CILEN_SHORT, nakp);
+				PUTSHORT(PPP_PAP, nakp);
+			}
+			break;
+		
+		case CI_QUALITY:
+			GETSHORT(cishort, p);
+			GETLONG(cilong, p);
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " QUALITY (%x %x)", cishort, (unsigned int) cilong);
+			traceNdx = strlen(traceBuf);
+#endif
+
+			if (!ao->neg_lqr ||
+					cilen != CILEN_LQR) {
+				orc = CONFREJ;
+				break;
+			}
+			
+			/*
+			 * Check the protocol and the reporting period.
+			 * XXX When should we Nak this, and what with?
+			 */
+			if (cishort != PPP_LQR) {
+				orc = CONFNAK;
+				PUTCHAR(CI_QUALITY, nakp);
+				PUTCHAR(CILEN_LQR, nakp);
+				PUTSHORT(PPP_LQR, nakp);
+				PUTLONG(ao->lqr_period, nakp);
+				break;
+			}
+			break;
+		
+		case CI_MAGICNUMBER:
+			if (!(ao->neg_magicnumber || go->neg_magicnumber) ||
+					cilen != CILEN_LONG) {
+				orc = CONFREJ;
+				break;
+			}
+			GETLONG(cilong, p);
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " MAGICNUMBER (%lX)", cilong);
+			traceNdx = strlen(traceBuf);
+#endif
+
+			/*
+			 * He must have a different magic number.
+			 */
+			if (go->neg_magicnumber &&
+					cilong == go->magicnumber) {
+				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:
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " PCOMPRESSION");
+			traceNdx = strlen(traceBuf);
+#endif
+			if (!ao->neg_pcompression ||
+					cilen != CILEN_VOID) {
+				orc = CONFREJ;
+				break;
+			}
+			ho->neg_pcompression = 1;
+			break;
+		
+		case CI_ACCOMPRESSION:
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " ACCOMPRESSION");
+			traceNdx = strlen(traceBuf);
+#endif
+			if (!ao->neg_accompression ||
+					cilen != CILEN_VOID) {
+				orc = CONFREJ;
+				break;
+			}
+			ho->neg_accompression = 1;
+			break;
+		
+		case CI_MRRU:
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " CI_MRRU");
+			traceNdx = strlen(traceBuf);
+#endif
+			orc = CONFREJ;
+			break;
+		
+		case CI_SSNHF:
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " CI_SSNHF");
+			traceNdx = strlen(traceBuf);
+#endif
+			orc = CONFREJ;
+			break;
+		
+		case CI_EPDISC:
+#if TRACELCP > 0
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " CI_EPDISC");
+			traceNdx = strlen(traceBuf);
+#endif
+			orc = CONFREJ;
+			break;
+		
+		default:
+#if TRACELCP
+			snprintf(&traceBuf[traceNdx], sizeof(traceBuf), " unknown %d", citype);
+			traceNdx = strlen(traceBuf);
+#endif
+			orc = CONFREJ;
+			break;
+		}
+		
+	endswitch:
+#if TRACELCP
+		if (traceNdx >= 80 - 32) {
+			LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd%s\n", traceBuf));
+			traceNdx = 0;
+		}
+#endif
+		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 = (int)(next - inp);
+		break;
+	case CONFNAK:
+		/*
+		 * Copy the Nak'd options from the nak_buffer to the caller's buffer.
+		 */
+		*lenp = (int)(nakp - nak_buffer);
+		BCOPY(nak_buffer, inp, *lenp);
+		break;
+	case CONFREJ:
+		*lenp = (int)(rejp - inp);
+		break;
+	}
+	
+#if TRACELCP > 0
+	if (traceNdx > 0) {
+		LCPDEBUG((LOG_INFO, "lcp_reqci: %s\n", traceBuf));
+	}
+#endif
+	LCPDEBUG((LOG_INFO, "lcp_reqci: returning CONF%s.\n", CODENAME(rc)));
+	return (rc);			/* Return final code */
+}
+
+
+/*
+ * lcp_up - LCP has come UP.
+ */
+static void lcp_up(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, LWIP_MIN(ao->mru, (ho->neg_mru? ho->mru: PPP_MRU)),
+				(ho->neg_asyncmap? ho->asyncmap: 0xffffffffl),
+				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? LWIP_MAX(wo->mru, go->mru): PPP_MRU),
+				(go->neg_asyncmap? go->asyncmap: 0x00000000),
+				go->neg_pcompression, go->neg_accompression);
+	
+	if (ho->neg_mru)
+		peer_mru[f->unit] = ho->mru;
+	
+	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(fsm *f)
+{
+	lcp_options *go = &lcp_gotoptions[f->unit];
+	
+	lcp_echo_lowerdown(f->unit);
+	
+	link_down(f->unit);
+	
+	ppp_send_config(f->unit, PPP_MRU, 0xffffffffl, 0, 0);
+	ppp_recv_config(f->unit, PPP_MRU,
+				(go->neg_asyncmap? go->asyncmap: 0x00000000),
+				go->neg_pcompression, go->neg_accompression);
+	peer_mru[f->unit] = PPP_MRU;
+}
+
+
+/*
+ * lcp_starting - LCP needs the lower layer up.
+ */
+static void lcp_starting(fsm *f)
+{
+	link_required(f->unit);
+}
+
+
+/*
+ * lcp_finished - LCP has finished with the lower layer.
+ */
+static void lcp_finished(fsm *f)
+{
+	link_terminated(f->unit);
+}
+
+
+#if 0
+/*
+ * print_string - print a readable representation of a string using
+ * printer.
+ */
+static void print_string(
+    char *p,
+    int len,
+    void (*printer) (void *, char *, ...),
+    void *arg
+)
+{
+    int c;
+    
+    printer(arg, "\"");
+    for (; len > 0; --len) {
+        c = *p++;
+        if (' ' <= c && c <= '~') {
+            if (c == '\\' || c == '"')
+                printer(arg, "\\");
+            printer(arg, "%c", c);
+        } else {
+            switch (c) {
+            case '\n':
+                printer(arg, "\\n");
+                break;
+            case '\r':
+                printer(arg, "\\r");
+                break;
+            case '\t':
+                printer(arg, "\\t");
+                break;
+            default:
+                printer(arg, "\\%.3o", c);
+            }
+        }
+    }
+    printer(arg, "\"");
+}
+
+
+/*
+ * lcp_printpkt - print the contents of an LCP packet.
+ */
+static char *lcp_codenames[] = {
+	"ConfReq", "ConfAck", "ConfNak", "ConfRej",
+	"TermReq", "TermAck", "CodeRej", "ProtRej",
+	"EchoReq", "EchoRep", "DiscReq"
+};
+
+static int lcp_printpkt(
+	u_char *p,
+	int plen,
+	void (*printer) (void *, char *, ...),
+	void *arg
+)
+{
+	int code, id, len, olen;
+	u_char *pstart, *optend;
+	u_short cishort;
+	u32_t 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%lx", cilong);
+				}
+				break;
+			case CI_AUTHTYPE:
+				if (olen >= CILEN_SHORT) {
+					p += 2;
+					printer(arg, "auth ");
+					GETSHORT(cishort, p);
+					switch (cishort) {
+					case PPP_PAP:
+						printer(arg, "pap");
+						break;
+					case PPP_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 PPP_LQR:
+						printer(arg, "lqr");
+						break;
+					default:
+						printer(arg, "0x%x", cishort);
+					}
+				}
+				break;
+			case CI_CALLBACK:
+				if (olen >= CILEN_CHAR) {
+					p += 2;
+					printer(arg, "callback ");
+					GETSHORT(cishort, p);
+					switch (cishort) {
+					case CBCP_OPT:
+						printer(arg, "CBCP");
+						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;
+	
+	case TERMACK:
+	case TERMREQ:
+		if (len > 0 && *p >= ' ' && *p < 0x7f) {
+			printer(arg, " ");
+			print_string((char*)p, len, printer, arg);
+			p += len;
+			len = 0;
+		}
+		break;
+	
+	case ECHOREQ:
+	case ECHOREP:
+	case DISCREQ:
+		if (len >= 4) {
+			GETLONG(cilong, p);
+			printer(arg, " magic=0x%x", cilong);
+			p += 4;
+			len -= 4;
+		}
+		break;
+	}
+	
+	/* print the rest of the bytes in the packet */
+	for (; len > 0; --len) {
+		GETCHAR(code, p);
+		printer(arg, " %.2x", code);
+	}
+	
+	return (int)(p - pstart);
+}
+#endif
+
+/*
+ * Time to shut down the link because there is nothing out there.
+ */
+
+static void LcpLinkFailure (fsm *f)
+{
+	if (f->state == OPENED) {
+		LCPDEBUG((LOG_INFO, "No response to %d echo-requests\n", lcp_echos_pending));
+		LCPDEBUG((LOG_NOTICE, "Serial link appears to be disconnected.\n"));
+		lcp_close(f->unit, "Peer not responding");
+	}
+}
+
+/*
+ * Timer expired for the LCP echo requests from this process.
+ */
+
+static void LcpEchoCheck (fsm *f)
+{
+	LcpSendEchoRequest (f);
+	
+	/*
+	 * Start the timer for the next interval.
+	 */
+	LWIP_ASSERT("lcp_echo_timer_running == 0", lcp_echo_timer_running == 0);
+
+	TIMEOUT (LcpEchoTimeout, f, lcp_echo_interval);
+	lcp_echo_timer_running = 1;
+}
+
+/*
+ * LcpEchoTimeout - Timer expired on the LCP echo
+ */
+
+static void LcpEchoTimeout (void *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 (fsm *f, int id, u_char *inp, int len)
+{
+	u32_t magic;
+	
+	(void)id;
+
+	/* Check the magic number - don't count replies from ourselves. */
+	if (len < 4) {
+		LCPDEBUG((LOG_WARNING, "lcp: received short Echo-Reply, length %d\n", len));
+		return;
+	}
+	GETLONG(magic, inp);
+	if (lcp_gotoptions[f->unit].neg_magicnumber
+			&& magic == lcp_gotoptions[f->unit].magicnumber) {
+		LCPDEBUG((LOG_WARNING, "appear to have received our own echo-reply!\n"));
+		return;
+	}
+	
+	/* Reset the number of outstanding echo frames */
+	lcp_echos_pending = 0;
+}
+
+/*
+ * LcpSendEchoRequest - Send an echo request frame to the peer
+ */
+
+static void LcpSendEchoRequest (fsm *f)
+{
+	u32_t 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].magicnumber;
+		pktp = pkt;
+		PUTLONG(lcp_magic, pktp);
+		fsm_sdata(f, ECHOREQ, (u_char)(lcp_echo_number++ & 0xFF), pkt, (int)(pktp - pkt));
+	}
+}
+
+/*
+ * lcp_echo_lowerup - Start the timer for the LCP frame
+ */
+
+static void lcp_echo_lowerup (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 (int unit)
+{
+	fsm *f = &lcp_fsm[unit];
+	
+	if (lcp_echo_timer_running != 0) {
+		UNTIMEOUT (LcpEchoTimeout, f);
+		lcp_echo_timer_running = 0;
+	}
+}
+
+#endif /* PPP_SUPPORT */