ciaddr2 = htonl(tl);	    IPCPDEBUG((LOG_INFO, "%s)", ip_ntoa(ciaddr2)));	    if (ciaddr2 != wo->ouraddr) {                if (ciaddr2 == 0 || !wo->accept_local) {                    orc = CONFNAK;                    if (!reject_if_disagree) {                        DECPTR(sizeof (long), p);                        tl = ntohl(wo->ouraddr);                        PUTLONG(tl, p);                    }                } else {                    go->ouraddr = ciaddr2;      /* accept peer's idea */                }            }	    ho->neg_addr = 1;	    ho->old_addrs = 1;	    ho->hisaddr = ciaddr1;	    ho->ouraddr = ciaddr2;	    break;	case CI_ADDR:	    IPCPDEBUG((LOG_INFO, "ipcp: received ADDR "));	    if (!ao->neg_addr ||		cilen != CILEN_ADDR) {	/* 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);                }            }	    ho->neg_addr = 1;	    ho->hisaddr = ciaddr1;	    break;		case CI_COMPRESSTYPE:	    IPCPDEBUG((LOG_INFO, "ipcp: received COMPRESSTYPE "));	    if (!ao->neg_vj ||		(cilen != CILEN_VJ && cilen != CILEN_COMPRESS)) {		orc = CONFREJ;		break;	    }	    GETSHORT(cishort, p);	    IPCPDEBUG((LOG_INFO, "(%d)", cishort));	    if (!(cishort == IPCP_VJ_COMP ||		  (cishort == IPCP_VJ_COMP_OLD && cilen == CILEN_COMPRESS))) {		orc = CONFREJ;		break;	    }	    ho->neg_vj = 1;	    ho->vj_protocol = cishort;	    if (cilen == CILEN_VJ) {		GETCHAR(maxslotindex, p);		if (maxslotindex > ao->maxslotindex) { 		    orc = CONFNAK;		    if (!reject_if_disagree){			DECPTR(1, p);			PUTCHAR(ao->maxslotindex, p);		    }		}		GETCHAR(cflag, p);		if (cflag && !ao->cflag) {		    orc = CONFNAK;		    if (!reject_if_disagree){			DECPTR(1, p);			PUTCHAR(wo->cflag, p);		    }		}                ho->maxslotindex = maxslotindex;                ho->cflag = wo->cflag;            } else {                ho->old_vj = 1;                ho->maxslotindex = MAX_STATES - 1;                ho->cflag = 1;            }            break;	default:	    orc = CONFREJ;	    break;	}endswitch:	IPCPDEBUG((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 */	}	/* Need to move CI? */	if (ucp != cip)	    BCOPY((char *)cip, (char *)ucp, cilen);	/* Move it */	/* Update output pointer */	INCPTR(cilen, ucp);    }    /*     * If we aren't rejecting this packet, and we want to negotiate     * their address, and they didn't send their address, then we     * send a NAK with a CI_ADDR option appended.  We assume the     * input buffer is long enough that we can append the extra     * option safely.     */    if (rc != CONFREJ && !ho->neg_addr &&	wo->req_addr && !reject_if_disagree) {	if (rc == CONFACK) {	    rc = CONFNAK;	    ucp = inp;			/* reset pointer */	    wo->req_addr = 0;		/* don't ask again */	}	PUTCHAR(CI_ADDR, ucp);	PUTCHAR(CILEN_ADDR, ucp);	tl = ntohl(wo->hisaddr);	PUTLONG(tl, ucp);    }    *len = ucp - inp;			/* Compute output length */    IPCPDEBUG((LOG_INFO, "ipcp: returning Configure-%s", CODENAME(rc)));    return (rc);			/* Return final code */}/* * ipcp_up - IPCP has come UP. * * Configure the IP network interface appropriately and bring it up. */static voidipcp_up(f)    fsm *f;{    u_long mask;    ipcp_options *ho = &ppp_if[f->unit]->ipcp_hisoptions;    ipcp_options *go = &ppp_if[f->unit]->ipcp_gotoptions;    IPCPDEBUG((LOG_INFO, "ipcp: up"));    go->default_route = 0;    go->proxy_arp = 0;    /*     * We must have a non-zero IP address for both ends of the link.     */    if (!ho->neg_addr)	ho->hisaddr = ppp_if[f->unit]->ipcp_wantoptions.hisaddr;    if (ho->hisaddr == 0) {	syslog(LOG_ERR, "Could not determine remote IP address");	ipcp_close(f->unit);	return;    }    if (go->ouraddr == 0) {	syslog(LOG_ERR, "Could not determine local IP address");	ipcp_close(f->unit);	return;    }    /*     * Check that the peer is allowed to use the IP address it wants.     */    if (!auth_ip_addr(f->unit, ho->hisaddr)) {	syslog(LOG_ERR, "Peer is not authorized to use remote address %s",	       ip_ntoa(ho->hisaddr));	ipcp_close(f->unit);	return;    }    syslog (LOG_NOTICE, "local  IP address %s", ip_ntoa(go->ouraddr));    syslog (LOG_NOTICE, "remote IP address %s", ip_ntoa(ho->hisaddr));    /*     * Set IP addresses and (if specified) netmask.     */    mask = GetMask(go->ouraddr);    if (!sifaddr(f->unit, go->ouraddr, ho->hisaddr, mask)) {	IPCPDEBUG((LOG_WARNING, "sifaddr failed"));	ipcp_close(f->unit);	return;    }    /* set tcp compression */    sifvjcomp(f->unit, ho->neg_vj, ho->cflag, ho->maxslotindex);    /* bring the interface up for IP */    if (!sifup(f->unit)) {	IPCPDEBUG((LOG_WARNING, "sifup failed"));	ipcp_close(f->unit);	return;    }    /* assign a default route through the interface if required */    if (ppp_if[f->unit]->ipcp_wantoptions.default_route) 	if (sifdefaultroute(f->unit, ho->hisaddr))	    go->default_route = 1;    /* Make a proxy ARP entry if requested. */    if (ppp_if[f->unit]->ipcp_wantoptions.proxy_arp)	if (sifproxyarp(f->unit, ho->hisaddr))	    go->proxy_arp = 1;}/* * ipcp_down - IPCP has gone DOWN. * * Take the IP network interface down, clear its addresses * and delete routes through it. */static voidipcp_down(f)    fsm *f;{    u_long ouraddr, hisaddr;    IPCPDEBUG((LOG_INFO, "ipcp: down"));    ouraddr = ppp_if[f->unit]->ipcp_gotoptions.ouraddr;    hisaddr = ppp_if[f->unit]->ipcp_hisoptions.hisaddr;    if (ppp_if[f->unit]->ipcp_gotoptions.proxy_arp)	cifproxyarp(f->unit, hisaddr);    if (ppp_if[f->unit]->ipcp_gotoptions.default_route) 	cifdefaultroute(f->unit, hisaddr);    sifdown(f->unit);    cifaddr(f->unit, ouraddr, hisaddr);}#ifdef	notyet/* * ipcp_script - Execute a script with arguments * interface-name tty-name speed local-IP remote-IP. */static voidipcp_script(f, script)    fsm *f;    char *script;{    char strspeed[32], strlocal[32], strremote[32];    char *argv[8];    sprintf(strspeed, "%d", ppp_if[f->unit]->baud_rate);    strcpy(strlocal, ip_ntoa(ppp_if[f->unit]->ipcp_gotoptions.ouraddr));    strcpy(strremote, ip_ntoa(ppp_if[f->unit]->ipcp_hisoptions.hisaddr));    argv[0] = script;    argv[1] = ppp_if[f->unit]->ifname;    argv[2] = ppp_if[f->unit]->devname;    argv[3] = strspeed;    argv[4] = strlocal;    argv[5] = strremote;    argv[6] = NULL;    run_program(script, argv, 0);}#endif	/* notyet *//* * ipcp_printpkt - print the contents of an IPCP packet. */char *ipcp_codenames[] = {    "ConfReq", "ConfAck", "ConfNak", "ConfRej",    "TermReq", "TermAck", "CodeRej"};intipcp_printpkt(p, plen, printer, arg)    u_char *p;    int plen;    void (*printer)();    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(ipcp_codenames) / sizeof(char *))        printer(arg, " %s", ipcp_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_ADDRS:                if (olen == CILEN_ADDRS) {                    p += 2;                    GETLONG(cilong, p);                    printer(arg, "addrs %s", ip_ntoa(htonl(cilong)));                    GETLONG(cilong, p);                    printer(arg, " %s", ip_ntoa(htonl(cilong)));                }                break;            case CI_COMPRESSTYPE:                if (olen >= CILEN_COMPRESS) {                    p += 2;                    GETSHORT(cishort, p);                    printer(arg, "compress ");                    switch (cishort) {                    case IPCP_VJ_COMP:                        printer(arg, "VJ");                        break;                    case IPCP_VJ_COMP_OLD:                        printer(arg, "old-VJ");                        break;                    default:                        printer(arg, "0x%x", cishort);                    }                }                break;            case CI_ADDR:                if (olen == CILEN_ADDR) {                    p += 2;                    GETLONG(cilong, p);                    printer(arg, "addr %s", ip_ntoa(htonl(cilong)));                }                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;}