GETCHAR(citype, p); \	GETCHAR(cilen, p); \	if (cilen != addrlen || \	    citype != opt) \	    goto bad; \	GETLONG(l, p); \	cilong = htonl(l); \	if (val1 != cilong) \	    goto bad; \	if (old) { \	    GETLONG(l, p); \	    cilong = htonl(l); \	    if (val2 != cilong) \		goto bad; \	} \    }    ACKCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), go->neg_addr,	      go->old_addrs, go->ouraddr, go->hisaddr);    ACKCIVJ(CI_COMPRESSTYPE, go->neg_vj, go->vj_protocol, go->old_vj,	    go->maxslotindex, go->cflag);    /*     * If there are any remaining CIs, then this packet is bad.     */    if (len != 0)	goto bad;    return (1);bad:    IPCPDEBUG((LOG_INFO, "ipcp_ackci: received bad Ack!"));    return (0);}/* * ipcp_nakci - Peer has sent a NAK for some of our CIs. * This should not modify any state if the Nak is bad * or if IPCP is in the OPENED state. * * Returns: *	0 - Nak was bad. *	1 - Nak was good. */static intipcp_nakci(f, p, len)    fsm *f;    u_char *p;    int len;{    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;    u_char cimaxslotindex = 0, cicflag = 0;    u_char citype, cilen, *next;    u_short cishort;    u_long ciaddr1, ciaddr2, l;    ipcp_options no;		/* options we've seen Naks for */    ipcp_options try;		/* options to request next time */    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 NAKCIADDR(opt, neg, old, code) \    if (go->neg && \	len >= (cilen = (old? CILEN_ADDRS: CILEN_ADDR)) && \	p[1] == cilen && \	p[0] == opt) { \	len -= cilen; \	INCPTR(2, p); \	GETLONG(l, p); \	ciaddr1 = htonl(l); \	if (old) { \	    GETLONG(l, p); \	    ciaddr2 = htonl(l); \	    no.old_addrs = 1; \	} else \	    ciaddr2 = 0; \	no.neg = 1; \	code \    }#define NAKCIVJ(opt, neg, code) \    if (go->neg && \	((cilen = p[1]) == CILEN_COMPRESS || cilen == CILEN_VJ) && \	len >= cilen && \	p[0] == opt) { \	len -= cilen; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	no.neg = 1; \        code \    }    /*     * Accept the peer's idea of {our,his} address, if different     * from our idea, only if the accept_{local,remote} flag is set.     */    NAKCIADDR(CI_ADDR, neg_addr, go->old_addrs,              if (go->accept_local && ciaddr1) { /* Do we know our address? */                  try.ouraddr = ciaddr1;                  IPCPDEBUG((LOG_INFO, "local IP address %s",                             ip_ntoa(ciaddr1)));              }              if (go->accept_remote && ciaddr2) { /* Does he know his? */                  try.hisaddr = ciaddr2;                  IPCPDEBUG((LOG_INFO, "remote IP address %s",                             ip_ntoa(ciaddr2)));              }              );    /*     * Accept the peer's value of maxslotindex provided that it     * is less than what we asked for.  Turn off slot-ID compression     * if the peer wants.  Send old-style compress-type option if     * the peer wants.     */    NAKCIVJ(CI_COMPRESSTYPE, neg_vj,	    if (cilen == CILEN_VJ) {                GETCHAR(cimaxslotindex, p);                GETCHAR(cicflag, p);		if (cishort == IPCP_VJ_COMP) {		    try.old_vj = 0;		    if (cimaxslotindex < go->maxslotindex)			try.maxslotindex = cimaxslotindex;		    if (!cicflag)			try.cflag = 0;		} else {		    try.neg_vj = 0;		}	    } else {		if (cishort == IPCP_VJ_COMP || cishort == IPCP_VJ_COMP_OLD) {		    try.old_vj = 1;		    try.vj_protocol = cishort;		} else {		    try.neg_vj = 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 they want to negotiate about IP addresses, we comply.     * If they want us to ask for compression, we refuse.     */    while (len > CILEN_VOID) {	GETCHAR(citype, p);	GETCHAR(cilen, p);	if( (len -= cilen) < 0 )	    goto bad;	next = p + cilen - 2;	switch (citype) {	case CI_COMPRESSTYPE:	    if (go->neg_vj || no.neg_vj ||		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS))		goto bad;	    no.neg_vj = 1;	    break;	case CI_ADDRS:	    if ((go->neg_addr && go->old_addrs) || no.old_addrs		|| cilen != CILEN_ADDRS)		goto bad;	    try.neg_addr = 1;	    try.old_addrs = 1;	    GETLONG(l, p);	    ciaddr1 = htonl(l);	    if (ciaddr1 && go->accept_local)		try.ouraddr = ciaddr1;	    GETLONG(l, p);	    ciaddr2 = htonl(l);	    if (ciaddr2 && go->accept_remote)		try.hisaddr = ciaddr2;	    no.old_addrs = 1;	    break;	case CI_ADDR:	    if (go->neg_addr || no.neg_addr || cilen != CILEN_ADDR)		goto bad;	    try.neg_addr = 1;	    try.old_addrs = 0;	    GETLONG(l, p);	    ciaddr1 = htonl(l);	    if (ciaddr1 && go->accept_local)		try.ouraddr = ciaddr1;	    no.neg_addr = 1;	    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;    return 1;bad:    IPCPDEBUG((LOG_INFO, "ipcp_nakci: received bad Nak!"));    return 0;}/* * ipcp_rejci - Reject some of our CIs. */static intipcp_rejci(f, p, len)    fsm *f;    u_char *p;    int len;{    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;    u_char cimaxslotindex, ciflag, cilen;    u_short cishort;    u_long cilong;    ipcp_options try;		/* options to request next time */    try = *go;    /*     * Bring down link if peer rejects the IPCP address configuration option,     * since if the IP address can't be negotiated then the link is useless.     */    /*     * 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 REJCIADDR(opt, neg, old, val1, val2) \    if (go->neg && \	len >= (cilen = old? CILEN_ADDRS: CILEN_ADDR) && \	p[1] == cilen && \	p[0] == opt) { \	u_long l; \        die(f->unit, 1); /* not to protocol spec. see note in ipcp_close() */ \	len -= cilen; \	INCPTR(2, p); \	GETLONG(l, p); \	cilong = htonl(l); \	/* Check rejected value. */ \	if (cilong != val1) \	    goto bad; \	if (old) { \	    GETLONG(l, p); \	    cilong = htonl(l); \	    /* Check rejected value. */ \	    if (cilong != val2) \		goto bad; \	} \	try.neg = 0; \    }#define REJCIVJ(opt, neg, val, old, maxslot, cflag) \    if (go->neg && \	p[1] == (old? CILEN_COMPRESS : CILEN_VJ) && \	len >= p[1] && \	p[0] == opt) { \	len -= p[1]; \	INCPTR(2, p); \	GETSHORT(cishort, p); \	/* Check rejected value. */  \	if (cishort != val) \	    goto bad; \	if (!old) { \	   GETCHAR(cimaxslotindex, p); \	   if (cimaxslotindex != maxslot) \	     goto bad; \	   GETCHAR(ciflag, p); \	   if (ciflag != cflag) \	     goto bad; \        } \	try.neg = 0; \     }    REJCIADDR((go->old_addrs? CI_ADDRS: CI_ADDR), neg_addr,	      go->old_addrs, go->ouraddr, go->hisaddr);    REJCIVJ(CI_COMPRESSTYPE, neg_vj, go->vj_protocol, go->old_vj,	    go->maxslotindex, go->cflag);    /*     * 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:    IPCPDEBUG((LOG_INFO, "ipcp_rejci: received bad Reject!"));    return 0;}/* * ipcp_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 intipcp_reqci(f, inp, len, reject_if_disagree)    fsm *f;    u_char *inp;                /* Requested CIs */    int *len;                   /* Length of requested CIs */    int reject_if_disagree;{    ipcp_options *wo = &ppp_if[f->unit]->ipcp_wantoptions;    ipcp_options *ho = &ppp_if[f->unit]->ipcp_hisoptions;    ipcp_options *ao = &ppp_if[f->unit]->ipcp_allowoptions;    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;    u_char *cip, *next;		/* Pointer to current and next CIs */    u_short cilen, citype;	/* Parsed len, type */    u_short cishort;		/* Parsed short value */    u_long tl, ciaddr1, ciaddr2;/* Parsed address values */    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 = *len;		/* Length left */    u_char maxslotindex, cflag;    /*     * Reset all his options.     */    BZERO((char *)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? */	    IPCPDEBUG((LOG_INFO, "ipcp_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_ADDRS:	    IPCPDEBUG((LOG_INFO, "ipcp: received ADDRS "));	    if (!ao->neg_addr ||		cilen != CILEN_ADDRS) {	/* Check CI length */		orc = CONFREJ;		/* Reject CI */		break;	    }	    /*	     * If he has no address, or if we both have his address but	     * disagree about it, then NAK it with our idea.	     * In particular, if we don't know his address, but he does,	     * then accept it.	     */	    GETLONG(tl, p);		/* Parse source address (his) */	    ciaddr1 = htonl(tl);	    IPCPDEBUG((LOG_INFO, "(%s:", ip_ntoa(ciaddr1)));	    if (ciaddr1 != wo->hisaddr                && (ciaddr1 == 0 || !wo->accept_remote)) {		orc = CONFNAK;		if (!reject_if_disagree) {		    DECPTR(sizeof (long), p);		    tl = ntohl(wo->hisaddr);		    PUTLONG(tl, p);		}	    }	    /*	     * If he doesn't know our address, or if we both have our address	     * but disagree about it, then NAK it with our idea.	     */	    GETLONG(tl, p);		/* Parse desination address (ours) */