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 intlcp_nakci(f, p, len)    fsm *f;    u_char *p;    int len;{    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;    lcp_options *wo = &ppp_if[f->unit]->lcp_wantoptions;    u_char cilen, citype, cichar, *next;    u_short cishort = 0;    u_long cilong;    lcp_options no;		/* options we've seen Naks for */    lcp_options try;		/* options to request next time */    int looped_back = 0;    BZERO((char *)&no, sizeof(no));    try = *go;    /*     * Any Nak'd CIs must be in exactly the same order that we sent.     * Check packet length and CI length at each step.     * If we find any deviations, then this packet is bad.     */#define NAKCIVOID(opt, neg, code) \    if (go->neg && \	len >= CILEN_VOID && \	p[1] == CILEN_VOID && \	p[0] == opt) { \	len -= CILEN_VOID; \	INCPTR(CILEN_VOID, p); \	no.neg = 1; \	code \    }#define NAKCICHAP(opt, neg, code) \    if (go->neg && \	len >= CILEN_CHAP && \	p[1] == CILEN_CHAP && \	p[0] == opt) { \	len -= CILEN_CHAP; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	GETCHAR(cichar, p); \	no.neg = 1; \	code \    }#define NAKCISHORT(opt, neg, code) \    if (go->neg && \	len >= CILEN_SHORT && \	p[1] == CILEN_SHORT && \	p[0] == opt) { \	len -= CILEN_SHORT; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	no.neg = 1; \	code \    }#define NAKCILONG(opt, neg, code) \    if (go->neg && \	len >= CILEN_LONG && \	p[1] == CILEN_LONG && \	p[0] == opt) { \	len -= CILEN_LONG; \	INCPTR(2, p); \	GETLONG(cilong, p); \	no.neg = 1; \	code \    }#define NAKCILQR(opt, neg, code) \    if (go->neg && \	len >= CILEN_LQR && \	p[1] == CILEN_LQR && \	p[0] == opt) { \	len -= CILEN_LQR; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	GETLONG(cilong, p); \	no.neg = 1; \	code \    }    /*     * We don't care if they want to send us smaller packets than     * we want.  Therefore, accept any MRU less than what we asked for,     * but then ignore the new value when setting the MRU in the kernel.     * If they send us a bigger MRU than what we asked, accept it, up to     * the limit of the default MRU we'd get if we didn't negotiate.     */    NAKCISHORT(CI_MRU, neg_mru,	       if (cishort <= wo->mru || cishort < DEFMRU)		   try.mru = cishort;	       );    /*     * Add any characters they want to our (receive-side) asyncmap.     */    NAKCILONG(CI_ASYNCMAP, neg_asyncmap,	      try.asyncmap = go->asyncmap | cilong;	      );    /*     * If they can't cope with our CHAP hash algorithm, we'll have     * to stop asking for CHAP.  We haven't got any other algorithm.     */    NAKCICHAP(CI_AUTHTYPE, neg_chap,	      try.neg_chap = 0;	      );    /*     * Peer shouldn't send Nak for UPAP, protocol compression or     * address/control compression requests; they should send     * a Reject instead.  If they send a Nak, treat it as a Reject.     */    if (!go->neg_chap ){	NAKCISHORT(CI_AUTHTYPE, neg_upap,		   try.neg_upap = 0;		   );    }    /*     * If they can't cope with our link quality protocol, we'll have     * to stop asking for LQR.  We haven't got any other protocol.     * If they Nak the reporting period, take their value XXX ?     */    NAKCILQR(CI_QUALITY, neg_lqr,	      if (cishort != LQR)		  try.neg_lqr = 0;	      else	          try.lqr_period = cilong;	      );    /*     * Check for a looped-back line.     */    NAKCILONG(CI_MAGICNUMBER, neg_magicnumber,	      try.magicnumber = magic();	      ++try.numloops;	      looped_back = 1;	      );    NAKCIVOID(CI_PCOMPRESSION, neg_pcompression,	      try.neg_pcompression = 0;	      );    NAKCIVOID(CI_ACCOMPRESSION, neg_accompression,	      try.neg_accompression = 0;	      );    /*     * There may be remaining CIs, if the peer is requesting negotiation     * on an option that we didn't include in our request packet.     * If we see an option that we requested, or one we've already seen     * in this packet, then this packet is bad.     * If we wanted to respond by starting to negotiate on the requested     * option(s), we could, but we don't, because except for the     * authentication type and quality protocol, if we are not negotiating     * an option, it is because we were told not to.     * For the authentication type, the Nak from the peer means     * `let me authenticate myself with you' which is a bit pointless.     * For the quality protocol, the Nak means `ask me to send you quality     * reports', but if we didn't ask for them, we don't want them.     */    while (len > CILEN_VOID) {	GETCHAR(citype, p);	GETCHAR(cilen, p);	if( (len -= cilen) < 0 )	    goto bad;	next = p + cilen - 2;	switch (citype) {	case CI_MRU:	    if (go->neg_mru || no.neg_mru || cilen != CILEN_SHORT)		goto bad;	    break;	case CI_ASYNCMAP:	    if (go->neg_asyncmap || no.neg_asyncmap || cilen != CILEN_LONG)		goto bad;	    break;	case CI_AUTHTYPE:	    if (go->neg_chap || no.neg_chap || go->neg_upap || no.neg_upap)		goto bad;	    break;	case CI_MAGICNUMBER:	    if (go->neg_magicnumber || no.neg_magicnumber ||		cilen != CILEN_LONG)		goto bad;	    break;	case CI_PCOMPRESSION:	    if (go->neg_pcompression || no.neg_pcompression		|| cilen != CILEN_VOID)		goto bad;	    break;	case CI_ACCOMPRESSION:	    if (go->neg_accompression || no.neg_accompression		|| cilen != CILEN_VOID)		goto bad;	    break;	case CI_QUALITY:	    if (go->neg_lqr || no.neg_lqr || cilen != CILEN_LQR)		goto bad;	    break;	default:	    goto bad;	}	p = next;    }    /* If there is still anything left, this packet is bad. */    if (len != 0)	goto bad;    /*     * OK, the Nak is good.  Now we can update state.     */    if (f->state != OPENED) {	*go = try;	if (looped_back && try.numloops % lcp_warnloops == 0)	    LCPDEBUG((LOG_INFO, "The line appears to be looped back."));    }    return 1;bad:    LCPDEBUG((LOG_WARNING, "lcp_nakci: received bad Nak!"));    return 0;}/* * lcp_rejci - Peer has Rejected some of our CIs. * This should not modify any state if the Reject is bad * or if LCP is in the OPENED state. * * Returns: *	0 - Reject was bad. *	1 - Reject was good. */static intlcp_rejci(f, p, len)    fsm *f;    u_char *p;    int len;{    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;    u_char cichar = 0;    u_short cishort;    u_long cilong;#ifdef	DEBUGLCP    u_char *start = p;    int plen = len;#endif	/* DEBUGLCP */    lcp_options try;		/* options to request next time */    try = *go;    /*     * Any Rejected CIs must be in exactly the same order that we sent.     * Check packet length and CI length at each step.     * If we find any deviations, then this packet is bad.     */#define REJCIVOID(opt, neg) \    if (go->neg && \	len >= CILEN_VOID && \	p[1] == CILEN_VOID && \	p[0] == opt) { \	len -= CILEN_VOID; \	INCPTR(CILEN_VOID, p); \	try.neg = 0; \	LCPDEBUG((LOG_INFO, "lcp_rejci rejected void opt %d", opt)); \    }#define REJCISHORT(opt, neg, val) \    if (go->neg && \	len >= CILEN_SHORT && \	p[1] == CILEN_SHORT && \	p[0] == opt) { \	len -= CILEN_SHORT; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	/* Check rejected value. */ \	if (cishort != (u_short)val) \	    goto bad; \	try.neg = 0; \	LCPDEBUG((LOG_INFO,"lcp_rejci rejected short opt %d", opt)); \    }#define REJCICHAP(opt, neg, val, digest) \    if (go->neg && \	len >= CILEN_CHAP && \	p[1] == CILEN_CHAP && \	p[0] == opt) { \	len -= CILEN_CHAP; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	GETCHAR(cichar, p); \	/* Check rejected value. */ \	if (cishort != (u_short)val || cichar != (u_char)digest) \	    goto bad; \	try.neg = 0; \	LCPDEBUG((LOG_INFO,"lcp_rejci rejected chap opt %d", opt)); \    }#define REJCILONG(opt, neg, val) \    if (go->neg && \	len >= CILEN_LONG && \	p[1] == CILEN_LONG && \	p[0] == opt) { \	len -= CILEN_LONG; \	INCPTR(2, p); \	GETLONG(cilong, p); \	/* Check rejected value. */ \	if (cilong != (u_long)val) \	    goto bad; \	try.neg = 0; \	LCPDEBUG((LOG_INFO,"lcp_rejci rejected long opt %d", opt)); \    }#define REJCILQR(opt, neg, val) \    if (go->neg && \	len >= CILEN_LQR && \	p[1] == CILEN_LQR && \	p[0] == opt) { \	len -= CILEN_LQR; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	GETLONG(cilong, p); \	/* Check rejected value. */ \	if (cishort != LQR || cilong != val) \	    goto bad; \	try.neg = 0; \	LCPDEBUG((LOG_INFO,"lcp_rejci rejected LQR opt %d", opt)); \    }    REJCISHORT(CI_MRU, neg_mru, go->mru);    REJCILONG(CI_ASYNCMAP, neg_asyncmap, go->asyncmap);    REJCICHAP(CI_AUTHTYPE, neg_chap, CHAP, go->chap_mdtype);    if (!go->neg_chap) {	REJCISHORT(CI_AUTHTYPE, neg_upap, UPAP);    }    REJCILQR(CI_QUALITY, neg_lqr, go->lqr_period);    REJCILONG(CI_MAGICNUMBER, neg_magicnumber, go->magicnumber);    REJCIVOID(CI_PCOMPRESSION, neg_pcompression);    REJCIVOID(CI_ACCOMPRESSION, neg_accompression);    /*     * If there are any remaining CIs, then this packet is bad.     */    if (len != 0)	goto bad;    /*     * Now we can update state.     */    if (f->state != OPENED)	*go = try;    return 1;bad:    LCPDEBUG((LOG_WARNING, "lcp_rejci: received bad Reject!"));    LCPDEBUG((LOG_WARNING, "lcp_rejci: plen %d len %d off %d",              plen, len, p - start));    return 0;}/* * lcp_reqci - Check the peer's requested CIs and send appropriate response. * * Returns: CONFACK, CONFNAK or CONFREJ and input packet modified * appropriately.  If reject_if_disagree is non-zero, doesn't return * CONFNAK; returns CONFREJ if it can't return CONFACK. */static intlcp_reqci(f, inp, lenp, reject_if_disagree)    fsm *f;    u_char *inp;                /* Requested CIs */    int *lenp;                  /* Length of requested CIs */    int reject_if_disagree;{    lcp_options *go = &ppp_if[f->unit]->lcp_gotoptions;    lcp_options *ho = &ppp_if[f->unit]->lcp_hisoptions;    lcp_options *ao = &ppp_if[f->unit]->lcp_allowoptions;    u_char *cip, *next;		/* Pointer to current and next CIs */    u_char cilen, citype = 0, cichar;/* Parsed len, type, char value */    u_short cishort;		/* Parsed short value */    u_long cilong;		/* Parse long value */    int rc = CONFACK;		/* Final packet return code */    int orc;			/* Individual option return code */    u_char *p;			/* Pointer to next char to parse */    u_char *rejp;		/* Pointer to next char in reject frame */    u_char *nakp;		/* Pointer to next char in Nak frame */    int l = *lenp;		/* Length left */    /*     * Reset all his options.     */    BZERO((char *)ho, sizeof(*ho));    /*     * Process all his options.     */    next = inp;    nakp = nak_buffer;    rejp = inp;    while (l) {	orc = CONFACK;			/* Assume success */	cip = p = next;			/* Remember begining of CI */	if (l < 2 ||			/* Not enough data for CI header or */	    p[1] < 2 ||			/*  CI length too small or */	    p[1] > l) {			/*  CI length too big? */	    LCPDEBUG((LOG_WARNING, "lcp_reqci: bad CI length!"));	    orc = CONFREJ;		/* Reject bad CI */	    cilen = l;			/* Reject till end of packet */	    l = 0;			/* Don't loop again */	    goto endswitch;	}	GETCHAR(citype, p);		/* Parse CI type */	GETCHAR(cilen, p);		/* Parse CI length */	l -= cilen;			/* Adjust remaining length */	next += cilen;			/* Step to next CI */	switch (citype) {		/* Check CI type */	case CI_MRU:	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd MRU"));	    if (!ao->neg_mru ||		/* Allow option? */		cilen != CILEN_SHORT) {	/* Check CI length */		orc = CONFREJ;		/* Reject CI */		break;	    }	    GETSHORT(cishort, p);	/* Parse MRU */	    LCPDEBUG((LOG_INFO, "(%d)", cishort));	    /*	     * He must be able to receive at least our minimum.	     * No need to check a maximum.  If he sends a large number,	     * we'll just ignore it.	     */	    if (cishort < MINMRU) {		orc = CONFNAK;		/* Nak CI */		if( !reject_if_disagree ){		    DECPTR(sizeof (short), p);	/* Backup */		    PUTSHORT(MINMRU, p);	/* Give him a hint */		}		break;	    }	    ho->neg_mru = 1;		/* Remember he sent MRU */	    ho->mru = cishort;		/* And remember value */	    break;	case CI_ASYNCMAP:	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd ASYNCMAP"));	    if (!ao->neg_asyncmap ||		cilen != CILEN_LONG) {		orc = CONFREJ;		break;	    }	    GETLONG(cilong, p);	    LCPDEBUG((LOG_INFO, "(%lx)", cilong));	    /*	     * Asyncmap must have set at least the bits	     * which are set in lcp_allowoptions[unit].asyncmap.	     */	    if ((ao->asyncmap & ~cilong) != 0) {		orc = CONFNAK;		if( !reject_if_disagree ){		    DECPTR(sizeof (long), p);		    PUTLONG(ao->asyncmap | cilong, p);		}		break;	    }	    ho->neg_asyncmap = 1;	    ho->asyncmap = cilong;	    break;	case CI_AUTHTYPE:	    LCPDEBUG((LOG_INFO, "lcp_reqci: rcvd AUTHTYPE"));	    if (cilen < CILEN_SHORT ||		!(ao->neg_upap || ao->neg_chap)) {		orc = CONFREJ;		if (!ao->neg_upap && !ao->neg_chap)		    LCPDEBUG((LOG_INFO, " we're not willing to authenticate"));		else		    LCPDEBUG((LOG_INFO, " cilen is too short!"));		break;	    }	    GETSHORT(cishort, p);	    LCPDEBUG((LOG_INFO, "(%x)", cishort));	    /*	     * Authtype must be UPAP or CHAP.	     *	     * Note: if both ao->neg_upap and ao->neg_chap are set,	     * and the peer sends a Configure-Request with two	     * authenticate-protocol requests, one for CHAP and one	     * for UPAP, then we will reject the second request.	     * Whether we end up doing CHAP or UPAP depends then on	     * the ordering of the CIs in the peer's Configure-Request.	     */	    if (cishort == UPAP) {		if (ho->neg_chap ||	/* we've already accepted CHAP */		    cilen != CILEN_SHORT) {		    LCPDEBUG((LOG_WARNING,			      "lcp_reqci: rcvd AUTHTYPE PAP, rejecting..."));		    orc = CONFREJ;		    break;		}		if (!ao->neg_upap) {	/* we don't want to do PAP */		    orc = CONFNAK;	/* NAK it and suggest CHAP */		    PUTCHAR(CI_AUTHTYPE, nakp);		    PUTCHAR(CILEN_CHAP, nakp);		    PUTSHORT(CHAP, nakp);		    PUTCHAR(ao->chap_mdtype, nakp);		    break;		}		ho->neg_upap = 1;		break;	    }	    if (cishort == CHAP) {		if (ho->neg_upap ||	/* we've already accepted PAP */		    cilen != CILEN_CHAP) {		    LCPDEBUG((LOG_INFO,			      "lcp_reqci: rcvd AUTHTYPE CHAP, rejecting..."));		    orc = CONFREJ;		    break;		}		if (!ao->neg_chap) {	/* we don't want to do CHAP */		    orc = CONFNAK;	/* NAK it and suggest PAP */		    PUTCHAR(CI_AUTHTYPE, nakp);		    PUTCHAR(CILEN_SHORT, nakp);		    PUTSHORT(UPAP, nakp);		    break;		}		GETCHAR(cichar, p);	/* get digest type*/		if (cichar != (u_char)ao->chap_mdtype) {		    orc = CONFNAK;		    PUTCHAR(CI_AUTHTYPE, nakp);		    PUTCHAR(CILEN_CHAP, nakp);		    PUTSHORT(CHAP, nakp);		    PUTCHAR(ao->chap_mdtype, nakp);		    break;		}		ho->chap_mdtype = cichar; /* save md type */		ho->neg_chap = 1;		break;