if (!fake_iquery)
if (!fake_iquery || dlen != INT32SZ)
			startxfr __P((struct qstream *, struct namebuf *,				      u_char *, int, int, const char *));static struct addinfo	addinfo[NADDRECS];static void		addname __P((const char *, const char *,				     u_int16_t, u_int16_t));static void		copyCharString __P((u_char **, const char *));/* * Process request using database; assemble and send response. */voidns_req(msg, msglen, buflen, qsp, from, dfd)	u_char *msg;	int msglen, buflen;	struct qstream *qsp;	struct sockaddr_in *from;	int dfd;{	register HEADER *hp = (HEADER *) msg;	u_char *cp, *eom;#ifdef DEBUG	const char *sortmsgtxt;#endif	enum req_action action;	int n;#ifdef DEBUG	if (debug > 3) {		fprintf(ddt, "ns_req(from=%s)\n", sin_ntoa(from));		fp_nquery(msg, msglen, ddt);	}#endif	/*	 * XXX - this decision should be made by our caller, not by us.	 */	if (hp->qr) {		ns_resp(msg, msglen);		/* Now is a safe time for housekeeping */		if (needs_prime_cache)			prime_cache();		return;	}	/* it's not a response so these bits have no business	 * being set. will later simplify work if we can	 * safely assume these are always 0 when a query	 * comes in.	 */	hp->aa = hp->ra = 0;	hp->rcode = NOERROR;	cp = msg + HFIXEDSZ;	eom = msg + msglen;	buflen -= HFIXEDSZ;	free_addinfo();	/* sets addcount to zero */	dnptrs[0] = NULL;	switch (hp->opcode) {	case QUERY:		action = req_query(hp, &cp, eom, qsp,				   &buflen, &msglen,				   msg, dfd, from);		break;	case IQUERY:		action = req_iquery(hp, &cp, eom, &buflen, msg, from);		break;#ifdef BIND_NOTIFY	case NS_NOTIFY_OP:		action = req_notify(hp, &cp, eom, msg, from);		break;#endif	default:		dprintf(1, (ddt, "ns_req: Opcode %d not implemented\n",			    hp->opcode));		/* XXX - should syslog, limited by haveComplained */		hp->qdcount = htons(0);		hp->ancount = htons(0);		hp->nscount = htons(0);		hp->arcount = htons(0);		hp->rcode = NOTIMP;		action = Finish;	}	/*	 * vector via internal opcode.  (yes, it was even uglier before.)	 */	switch (action) {	case Return:		return;	case Refuse:		hp->rcode = REFUSED;		/*FALLTHROUGH*/	case Finish:		/* rest of the function handles this case */		break;	default:		panic(-1, "ns_req: bad action variable");		/*NOTREACHED*/	}	/*	 * apply final polish	 */	hp->qr = 1;		/* set Response flag */	hp->ra = (NoRecurse == 0);	n = doaddinfo(hp, cp, buflen);	cp += n;	buflen -= n;#ifdef DEBUG#ifdef SORT_RESPONSE	sortmsgtxt = local(from) == NULL ? "Remote" : "Local";#else /*SORT*/	sortmsgtxt = "(not sorting)";#endif /*SORT*/	dprintf(1, (ddt, "ns_req: answer -> %s fd=%d id=%d size=%d %s\n",		    sin_ntoa(from), (qsp == QSTREAM_NULL) ? dfd : qsp->s_rfd,		    ntohs(hp->id), cp - msg, sortmsgtxt));	if (debug >= 10)		fp_nquery(msg, cp - msg, ddt);#endif /*DEBUG*/	if (qsp == QSTREAM_NULL) {		if (sendto(dfd, (char*)msg, cp - msg, 0,			   (struct sockaddr *)from,			   sizeof(*from)) < 0) {			if (!haveComplained((char*)from->sin_addr.s_addr,					    sendtoStr))				syslog(LOG_INFO,				       "ns_req: sendto(%s): %m",				       sin_ntoa(from));			nameserIncr(from->sin_addr, nssSendtoErr);		}		nameserIncr(from->sin_addr, nssSentAns);#ifdef XSTATS		if (hp->rcode == NXDOMAIN) 			nameserIncr(from->sin_addr, nssSentNXD);		if (!hp->aa) 			nameserIncr(from->sin_addr, nssSentNaAns);#endif	} else {		(void) writemsg(qsp->s_rfd, msg, cp - msg);		sq_done(qsp);	}	if (needs_prime_cache) {		prime_cache();		/* Now is a safe time */	}}#ifdef BIND_NOTIFYintfindZonePri(zp, from)	register const struct zoneinfo *zp;	const struct sockaddr_in *from;{	register u_int32_t from_addr = from->sin_addr.s_addr;	register int i;	for (i = 0; (u_int)i < zp->z_addrcnt; i++)		if (zp->z_addr[i].s_addr == from_addr)			return (i);	return (-1);}static enum req_actionreq_notify(hp, cpp, eom, msg, from)	HEADER *hp;	u_char **cpp, *eom, *msg;	struct sockaddr_in *from;{	int n, type, class, zn;	char dnbuf[MAXDNAME];	struct namebuf *np;	const char *fname;	struct hashbuf *htp = hashtab;		/* lookup relative to root */	/* valid notify's have one question and zero answers */	if ((ntohs(hp->qdcount) != 1)	    || ntohs(hp->ancount) != 0	    || ntohs(hp->nscount) != 0	    || ntohs(hp->arcount) != 0) {		dprintf(1, (ddt, "FORMERR Notify header counts wrong\n"));		hp->qdcount = htons(0);		hp->ancount = htons(0);		hp->nscount = htons(0);		hp->arcount = htons(0);		hp->rcode = FORMERR;		return (Finish);	}	n = dn_expand(msg, eom, *cpp, dnbuf, sizeof dnbuf);	if (n < 0) {		dprintf(1, (ddt, "FORMERR Query expand name failed\n"));		hp->rcode = FORMERR;		return (Finish);	}	*cpp += n;	GETSHORT(type, *cpp);	GETSHORT(class, *cpp);	syslog(LOG_INFO, "rcvd NOTIFY(%s %s %s)",	       dnbuf, p_class(class), p_type(type));	/* XXX - when answers are allowed, we'll need to do compression	 * correctly here, and we will need to check for packet underflow.	 */	np = nlookup(dnbuf, &htp, &fname, 0);	if (!np) {		syslog(LOG_INFO, "rcvd NOTIFY for \"%s\", name not in cache",		       dnbuf);		hp->rcode = SERVFAIL;		return (Finish);	}	zn = findMyZone(np, class);	if (zn == DB_Z_CACHE || zones[zn].z_type != Z_SECONDARY) {		/* this can come if a user did an AXFR of some zone somewhere		 * and that zone's server now wants to tell us that the SOA		 * has changed.  AXFR's always come from nonpriv ports so it		 * isn't possible to know whether it was the server or just		 * "dig".  this condition can be avoided by using secure zones		 * since that way only real secondaries can AXFR from you.		 */		syslog(LOG_INFO,		       "NOTIFY for non-secondary name (%s), from %s",		       dnbuf, sin_ntoa(from));		goto refuse;	}	if (findZonePri(&zones[zn], from) == -1) {		syslog(LOG_INFO,		       "NOTIFY from non-master server (zone %s), from %s",		       zones[zn].z_origin, sin_ntoa(from));		goto refuse;	}	switch (type) {	case T_SOA:		if (strcasecmp(dnbuf, zones[zn].z_origin) != 0) {			syslog(LOG_INFO,			       "NOTIFY(SOA) for non-origin (%s), from %s",			       dnbuf, sin_ntoa(from));			goto refuse;		}		if (zones[zn].z_flags &		    (Z_NEED_RELOAD|Z_NEED_XFER|Z_QSERIAL|Z_XFER_RUNNING)) {			syslog(LOG_INFO,			       "NOTIFY(SOA) for zone already xferring (%s)",			       dnbuf);			goto noerror;		}		zones[zn].z_time = tt.tv_sec;		qserial_query(&zones[zn]);		/* XXX: qserial_query() can fail due to queue full condition;		 *	we should detect that case here and do something.		 */		break;	default:		/* unimplemented, but it's not a protocol error, just		 * something to be ignored.		 */		break;	} noerror:	hp->rcode = NOERROR;	return (Finish); refuse:	hp->rcode = REFUSED;	return (Finish);}#endif /*BIND_NOTIFY*/static enum req_actionreq_query(hp, cpp, eom, qsp, buflenp, msglenp, msg, dfd, from)	HEADER *hp;	u_char **cpp;	u_char *eom;	struct qstream *qsp;	u_char *msg;	int *buflenp, *msglenp, dfd;	struct sockaddr_in *from;{	int n, class, type, count, foundname, founddata, omsglen, cname;	u_int16_t id;	u_char **dpp, *omsg, *answers;	char dnbuf[MAXDNAME], *dname;	const char *fname;	struct hashbuf *htp;	struct databuf *nsp[NSMAX];	struct namebuf *np, *anp;	struct qinfo *qp;	struct netinfo *lp;#ifdef SECURE_ZONES	struct zoneinfo *zp;#endif	struct databuf *dp;#ifdef XSTATS	nameserIncr(from->sin_addr, nssRcvdQ);#endif		nsp[0] = NULL;	dpp = dnptrs;	*dpp++ = msg;	*dpp = NULL;	/* valid queries have one question and zero answers */	if ((ntohs(hp->qdcount) != 1)	    || ntohs(hp->ancount) != 0	    || ntohs(hp->nscount) != 0	    || ntohs(hp->arcount) != 0) {		dprintf(1, (ddt, "FORMERR Query header counts wrong\n"));		hp->qdcount = htons(0);		hp->ancount = htons(0);		hp->nscount = htons(0);		hp->arcount = htons(0);		hp->rcode = FORMERR;		return (Finish);	}	/*	 * Get domain name, class, and type.	 */	if ((**cpp & INDIR_MASK) == 0) {		*dpp++ = *cpp;	/* remember name for compression */	}	*dpp = NULL;	n = dn_expand(msg, eom, *cpp, dnbuf, sizeof dnbuf);	if (n < 0) {		dprintf(1, (ddt, "FORMERR Query expand name failed\n"));		hp->rcode = FORMERR;		return (Finish);	}	*cpp += n;	GETSHORT(type, *cpp);	GETSHORT(class, *cpp);	if (*cpp > eom) {		dprintf(1, (ddt, "FORMERR Query message length short\n"));		hp->rcode = FORMERR;		return (Finish);	}	if (*cpp < eom) {		dprintf(6, (ddt,"message length > received message\n"));		*msglenp = *cpp - msg;	}	qtypeIncr(type);#if 0	/*	 * Yow!	 */	if (!strcasecmp(dnbuf, "VERSION.BIND") &&	    class == C_CHAOS && type == T_TXT) {		u_char *tp;		hp->ancount = htons(1);		hp->nscount = htons(0);		hp->arcount = htons(0);		hp->rcode = NOERROR;		hp->aa = 1;		hp->ra = 0;		copyCharString(cpp, "VERSION");	/* Name */		copyCharString(cpp, "BIND");		*(*cpp)++ = 0x00;		PUTSHORT(T_TXT, *cpp);		/* Type */		PUTSHORT(C_CHAOS, *cpp);	/* Class */		PUTLONG(0, *cpp);		/* TTL */		tp = *cpp;			/* Temp RdLength */		PUTSHORT(0, *cpp);		copyCharString(cpp, Version);		PUTSHORT((*cpp) - (tp + INT16SZ), tp);	/* Real RdLength */		*msglenp = *cpp - msg;		/* Total message length */		return (Finish);	}#endif	/*	 * Process query.	 */	if (type == T_AXFR) {		/* refuse request if not a TCP connection */		if (qsp == QSTREAM_NULL) {			syslog(LOG_INFO,			       "rejected UDP AXFR from %s for \"%s\"",			       sin_ntoa(from), *dnbuf ? dnbuf : ".");			return (Refuse);		}		/* the position of this is subtle. */		nameserIncr(from->sin_addr, nssRcvdAXFR);#ifdef XFRNETS		if (xfrnets) {			/* if xfrnets was specified, peer address			 * must be on it.  should probably allow			 * for negation some day.			 */			if (!addr_on_netlist(from->sin_addr, xfrnets)) {				syslog(LOG_INFO,				       "unapproved AXFR from %s for %s",				       sin_ntoa(from), *dnbuf ? dnbuf : ".");				return (Refuse);			}		}#endif /*XFRNETS*/		dnptrs[0] = NULL;	/* don't compress names */		hp->rd = 0;		/* recursion not possible */		syslog(LOG_INFO, "approved AXFR from %s for \"%s\"",		       sin_ntoa(from), *dnbuf ? dnbuf : ".");	}	*buflenp -= *msglenp;	count = 0;	foundname = 0;	founddata = 0;	dname = dnbuf;	cname = 0;#ifdef QRYLOG	if (qrylog) {		syslog(LOG_INFO, "XX /%s/%s/%s",		       inet_ntoa(from->sin_addr), 		       (dname[0] == '\0') ?"." :dname, 		       p_type(type));	}#endif /*QRYLOG*/ try_again:	dprintf(1, (ddt, "req: nlookup(%s) id %d type=%d class=%d\n",		    dname, ntohs(hp->id), type, class));	htp = hashtab;		/* lookup relative to root */	if ((anp = np = nlookup(dname, &htp, &fname, 0)) == NULL)		fname = "";	dprintf(1, (ddt, "req: %s '%s' as '%s' (cname=%d)\n",		    np == NULL ? "missed" : "found",		    dname, fname, cname));#ifdef LOCALDOM	/*	 * if nlookup failed to find the name then	 * see if there are any '.''s in the name	 * if not then add local domain name to the	 * name and try again.	 */	if (!np && localdomain && !strchr(dname, '.')) {		(void) strcat(dname, ".");		(void) strcat(dname, localdomain);		dprintf(1, (ddt,"req: nlookup(%s) type=%d\n", dname, type));		htp = hashtab;		np = nlookup(dname, &htp, &fname, 0);	}#endif /*LOCALDOM*/#ifdef YPKLUDGE	/* Some braindamaged resolver software will not 	   recognize internet addresses in dot notation and 	   send out address  queries for "names" such as 	   128.93.8.1.  This kludge will prevent those 	   from flooding higher level servers.	   We simply claim to be authoritative and that	   the domain doesn't exist.	   Note that we could return the address but we	   don't do that in order to encourage that broken	   software is fixed.	*/	if (!np && type == T_A && class == C_IN && dname) {		struct in_addr ina;		if (inet_aton(dname, &ina)) {			hp->rcode = NXDOMAIN;			hp->aa = 1;			dprintf(3, (ddt, "ypkludge: hit as '%s'\n", dname));			return (Finish);		}	}#endif /*YPKLUDGE*/	if ((!np) || (fname != dname))		goto fetchns;#ifdef SECURE_ZONES	/* (gdmr) Make sure the class is correct.  If we have the same name	 * with more than one class then we can't refuse a request for one	 * class just because another class is blocked.  We *really* ought	 * to look for the correct type too, but since everything in a	 * particular class of zone has the same secure_zone attribute it	 * doesn't really matter which type we use!  Alternatively, this lot	 * could all be moved to after the finddata(), by which time only	 * the correct class/type combinations will be left.	 */	dp = np->n_data;	while (dp && (dp->d_class != class))		dp = dp->d_next;	if (dp) {		zp = &zones[dp->d_zone];		if (zp->secure_nets		    && !addr_on_netlist(from->sin_addr, zp->secure_nets)) {			syslog(LOG_NOTICE, "Unauthorized request %s from %s",			       dname, sin_ntoa(from));			dprintf(1, (ddt, "req: refuse %s from %s class %d (%d)\n",				dname, sin_ntoa(from), class, zp->z_class));			return (Refuse);		}	}#endif	foundname++;	answers = *cpp;	count = *cpp - msg;#ifdef NCACHE	/* Look for NXDOMAIN record with appropriate class	 * if found return immediately	 */	for (dp = np->n_data; dp ; dp = dp->d_next) {		if (!stale(dp) && (dp->d_rcode == NXDOMAIN) &&		    (dp->d_class == class)) {#ifdef RETURNSOA			n = finddata(np, class, T_SOA, hp, &dname,				     buflenp, &count);			if (n != 0 ) {				if (count) {					*cpp += n;					*buflenp -= n;					*msglenp += n;					hp->nscount = htons((u_int16_t)count);				}				if (hp->rcode == NOERROR_NODATA) {					/* this should not occur */					hp->rcode = NOERROR;					return (Finish);				}			}#endif			hp->rcode = NXDOMAIN;			hp->aa = 1;			return (Finish);		}	}	/* if not NXDOMAIN, the NOERROR_NODATA record might be	 * anywhere in the chain. have to go through the grind.	 */#endif /*NCACHE*/	n = finddata(np, class, type, hp, &dname, buflenp, &count);	if (n == 0) {		/* NO data available.  Refuse AXFR requests, or		 * look for better servers for other requests.		 */		if (type == T_AXFR) {			dprintf(1, (ddt, "T_AXFR refused: no data\n"));			return (Refuse);		} else {			goto fetchns;		}	}#ifdef NCACHE	if (hp->rcode == NOERROR_NODATA) {		hp->rcode = NOERROR;#ifdef RETURNSOA		if (count) {			*cpp += n;			*buflenp -= n;			*msglenp += n;			hp->nscount = htons(count);		}#endif		founddata = 1;		return (Finish);	}#endif	*cpp += n;	*buflenp -= n;	*msglenp += n;	hp->ancount = htons(ntohs(hp->ancount) + (u_int16_t)count);	if (fname != dname && type != T_CNAME && type != T_ANY) {		if (cname++ >= MAXCNAMES) {			dprintf(3, (ddt,				    "resp: leaving, MAXCNAMES exceeded\n"));			hp->rcode = SERVFAIL;			return (Finish);		}		goto try_again;	}	founddata = 1;	dprintf(3, (ddt,		    "req: foundname=%d, count=%d, founddata=%d, cname=%d\n",		    foundname, count, founddata, cname));#ifdef SORT_RESPONSE	if ((lp = local(from)) != NULL) 		sort_response(answers, count, lp, *cpp);#endif#ifdef BIND_NOTIFY	if (type == T_SOA &&	    from->sin_port == ns_port &&	    np->n_data) {		int zn = np->n_data->d_zone;		if (zn != DB_Z_CACHE) {			struct notify	*ap;			/* Old? */			ap = findNotifyPeer(&zones[zn], from->sin_addr);			/* New? */			if (!ap && (ap = (struct notify *)malloc(sizeof *ap))) {				ap->addr = from->sin_addr;				ap->next = zones[zn].z_notifylist;				zones[zn].z_notifylist = ap;			}			/* Old or New? */			if (ap)				ap->last = tt.tv_sec;		}	}#endif /*BIND_NOTIFY*/	if (type == T_AXFR) {		startxfr(qsp, np, msg, *cpp - msg, class, dname);		return (Return);	}#ifdef notdef	/*	 * If we found an authoritative answer, we're done.	 */	if (hp->aa)		return (Finish);#endif fetchns:	/*	 * If we're already out of room in the response, we're done.	 */	if (hp->tc)		return (Finish);	/* 	 * Look for name servers to refer to and fill in the authority 	 * section or record the address for forwarding the query 	 * (recursion desired). 	 */	free_nsp(nsp);	nsp[0] = NULL;	count = 0;	switch (findns(&np, class, nsp, &count, 0)) {	case NXDOMAIN:		/* We are authoritative for this np. */		if (!foundname)			hp->rcode = NXDOMAIN;		dprintf(3, (ddt, "req: leaving (%s, rcode %d)\n",			    dname, hp->rcode));		if (class != C_ANY) {			hp->aa = 1;			if (np && (!foundname || !founddata)) {				n = doaddauth(hp, *cpp, *buflenp, np, nsp[0]);				*cpp += n;				*buflenp -= n;#ifdef ADDAUTH			} else if (ntohs(hp->ancount) != 0) {				/* don't add NS records for NOERROR NODATA				   as some servers can get confused */				free_nsp(nsp);				switch (findns(&np, class, nsp, &count, 1)) {				case NXDOMAIN:				case SERVFAIL:					break;				default:					if (np &&					    (type != T_NS || np != anp)					    ) {						n = add_data(np, nsp, *cpp,							     *buflenp, &count);						if (n < 0) {							hp->tc = 1;							n = (-n);						}						*cpp += n;						*buflenp -= n;						hp->nscount = 							htons((u_int16_t)							      count);					}				}#endif /*ADDAUTH*/			}		}		free_nsp(nsp);		return (Finish);	case SERVFAIL:		/* We're authoritative but the zone isn't loaded. */		if (!founddata && !(forward_only && fwdtab)) {			hp->rcode = SERVFAIL;			free_nsp(nsp);			return (Finish);		}	}	/*	 *  If we successfully found the answer in the cache,	 *  or this is not a recursive query, or we are purposely	 *  never recursing, then add the nameserver references	 *  ("authority section") here and we're done.	 */	if (founddata || !hp->rd || NoRecurse) {		/*		 * If the qtype was NS, and the np of the authority is		 * the same as the np of the data, we don't need to add		 * another copy of the answer here in the authority		 * section.		 */		if (!founddata || type != T_NS || anp != np) {			n = add_data(np, nsp, *cpp, *buflenp, &count);			if (n < 0) {				hp->tc = 1;				n = (-n);			}			*cpp += n;			*buflenp -= n;			hp->nscount = htons((u_int16_t)count);		}		free_nsp(nsp);		/* Our caller will handle the Additional section. */		return (Finish);	}	/*	 *  At this point, we don't have the answer, but we do	 *  have some NS's to try.  If the user would like us	 *  to recurse, create the initial query.  If a cname	 *  is involved, we need to build a new query and save	 *  the old one in cmsg/cmsglen.	 */	if (cname) {		omsg = (u_char *)malloc((unsigned) *msglenp);		if (omsg == (u_char *)NULL) {			syslog(LOG_INFO, "ns_req: Out Of Memory");			hp->rcode = SERVFAIL;			free_nsp(nsp);			return (Finish);		}		id = hp->id;		omsglen = *msglenp;		bcopy(msg, omsg, omsglen);		n = res_mkquery(QUERY, dname, class, type,				NULL, 0, NULL, msg,				*msglenp + *buflenp);		if (n < 0) {			syslog(LOG_INFO, "res_mkquery(%s) failed", dname);			hp->rcode = SERVFAIL;			free_nsp(nsp);			return (Finish);		}		*msglenp = n;	}	n = ns_forw(nsp, msg, *msglenp, from, qsp, dfd, &qp,		    dname, class, type, np);	if (n != FW_OK && cname)		free(omsg);	switch (n) {	case FW_OK:		if (cname) {			qp->q_cname = cname;			qp->q_cmsg = omsg;			qp->q_cmsglen = omsglen;			qp->q_id = id;		}		break;	case FW_DUP:		break;		/* Duplicate request dropped */	case FW_NOSERVER:		/* 		 * Don't go into an infinite loop if 		 * the admin gave root NS records in the cache		 * file without giving address records		 * for the root servers.		 */		if (np) {			if (NAME(*np)[0] == '\0') {				syslog(LOG_NOTICE, 				       "ns_req: no address for root server");				hp->rcode = SERVFAIL;				free_nsp(nsp);				return (Finish);			}#ifdef VALIDATE			/*			 * we need to kill all the NS records here as			 * validate will fail as we are talking to the parent			 * server			 */			delete_all(np, class, T_NS);#endif			for (dp = np->n_data; dp ; dp = dp->d_next)				if (dp->d_zone && match(dp, class, T_NS))					break;			if (dp) {				/*				 * we know the child zone exists but are				 * missing glue.				 *				 * nslookup has called sysquery() to get the				 * missing glue.				 *				 * for UDP, drop the response and let the				 * client retry.  for TCP, we should probably				 * (XXX) hold open the TCP connection for a				 * while in case the sysquery() comes back				 * soon.  meanwhile we SERVFAIL.				 */				if (qsp)					goto do_servfail;				break;			}			np = np_parent(np);		}		goto fetchns;	/* Try again. */	case FW_SERVFAIL: do_servfail:		hp->rcode = SERVFAIL;		free_nsp(nsp);		return (Finish);	}	free_nsp(nsp);	return (Return);}static enum req_actionreq_iquery(hp, cpp, eom, buflenp, msg, from)	HEADER *hp;	u_char **cpp, *eom;	int *buflenp;	u_char *msg;	struct sockaddr_in *from;{	int dlen, alen, n, type, class, count;	char dnbuf[MAXDNAME], anbuf[PACKETSZ], *data, *fname;#ifdef XSTATS	nameserIncr(from->sin_addr, nssRcvdIQ);#endif	if (ntohs(hp->ancount) != 1	    || ntohs(hp->qdcount) != 0	    || ntohs(hp->nscount) != 0	    || ntohs(hp->arcount) != 0) {		dprintf(1, (ddt, "FORMERR IQuery header counts wrong\n"));		hp->qdcount = htons(0);		hp->ancount = htons(0);		hp->nscount = htons(0);		hp->arcount = htons(0);		hp->rcode = FORMERR;		return (Finish);	}	/*	 * Skip domain name, get class, and type.	 */	if ((n = dn_skipname(*cpp, eom)) < 0) {		dprintf(1, (ddt, "FORMERR IQuery packet name problem\n"));		hp->rcode = FORMERR;		return (Finish);	}	*cpp += n;	GETSHORT(type, *cpp);	GETSHORT(class, *cpp);	*cpp += INT32SZ;	/* ttl */	GETSHORT(dlen, *cpp);	*cpp += dlen;	if (*cpp != eom) {		dprintf(1, (ddt, "FORMERR IQuery message length off\n"));		hp->rcode = FORMERR;		return (Finish);	}	/*	 * not all inverse queries are handled.	 */	switch (type) {	case T_A:#ifndef INVQ		if (!fake_iquery)			return (Refuse);#endif#ifdef INVQ	case T_UID:	case T_GID:#endif		break;	default:		return (Refuse);	}	dprintf(1, (ddt, "req: IQuery class %d type %d\n", class, type));	fname = (char *)msg + HFIXEDSZ;	bcopy(fname, anbuf, alen = (char *)*cpp - fname);	data = anbuf + alen - dlen;	*cpp = (u_char *)fname;	*buflenp -= HFIXEDSZ;	count = 0;#ifdef QRYLOG	if (qrylog) {		syslog(LOG_INFO, "XX /%s/%s/-%s",		       inet_ntoa(from->sin_addr), 		       inet_ntoa(data_inaddr((u_char *)data)),		       p_type(type));	}#endif /*QRYLOG*/#ifdef INVQ    {	register struct invbuf *ip;	for (ip = invtab[dhash((u_char *)data, dlen)];	     ip != NULL;	     ip = ip->i_next) {		int i;		for (i = 0; i < INVBLKSZ; i++) {			struct namebuf *np;			struct databuf *dp;			if ((np = ip->i_dname[i]) == NULL)				break;			dprintf(5, (ddt, "dname = %d\n", NAME(*np)));			for (dp = np->n_data; dp != NULL; dp = dp->d_next) {				if (!match(dp, class, type))					continue;				if (dp->d_size != dlen ||				    bcmp(dp->d_data, data, dlen))					continue;				getname(np, dnbuf, sizeof(dnbuf));				dprintf(2, (ddt, "req: IQuery found %s\n",					    dnbuf));				*buflenp -= QFIXEDSZ;				n = dn_comp(dnbuf, *cpp, *buflenp, NULL, NULL);				if (n < 0) {					hp->tc = 1;					return (Finish);				}				*cpp += n;				PUTSHORT((u_int16_t)dp->d_type, *cpp);				PUTSHORT((u_int16_t)dp->d_class, *cpp);				*buflenp -= n;				count++;			}		}	}    }#else /*INVQ*/	/*	 * We can only get here if we are compiled without INVQ (the default)	 * and the type is T_A and the option "fake-iquery" is on in the boot	 * file.	 *	 * What we do here is send back a bogus response of "[dottedquad]".	 * A better strategy would be to turn this into a PTR query, but that	 * would legitimize inverse queries in a way they do not deserve.	 */	sprintf(dnbuf, "[%s]", inet_ntoa(data_inaddr((u_char *)data)));	*buflenp -= QFIXEDSZ;	n = dn_comp(dnbuf, *cpp, *buflenp, NULL, NULL);	if (n < 0) {		hp->tc = 1;		return (Finish);	}	*cpp += n;	PUTSHORT((u_int16_t)type, *cpp);	PUTSHORT((u_int16_t)class, *cpp);	*buflenp -= n;	count++;#endif /*INVQ*/	dprintf(1, (ddt, "req: IQuery %d records\n", count));	hp->qdcount = htons((u_int16_t)count);	if (alen > *buflenp) {		hp->tc = 1;		return (Finish);	}	bcopy(anbuf, *cpp, alen);	*cpp += alen;	return (Finish);}static voidfwritemsg(rfp, msg, msglen)	FILE *rfp;	u_char *msg;	int msglen;{	u_char len[INT16SZ];	__putshort(msglen, len);	if (fwrite((char *)len, INT16SZ, 1, rfp) != 1 ||	    fwrite((char *)msg, msglen, 1, rfp) != 1) {		syslog(LOG_ERR, "fwritemsg: %m");		_exit(1);	}}/* *  Test a datum for validity and return non-zero if it is out of date. */intstale(dp)	register struct databuf *dp;{	register struct zoneinfo *zp = &zones[dp->d_zone];	switch (zp->z_type) {	case Z_PRIMARY:		return (0);#ifdef STUBS	case Z_STUB:		/* root stub zones have DB_F_HINT set */		if (dp->d_flags & DB_F_HINT)			return (0);		/* FALLTROUGH */#endif	case Z_SECONDARY:		/*		 * Check to see whether a secondary zone		 * has expired; if so clear authority flag		 * for zone and return true.  If lastupdate		 * is in the future, assume zone is up-to-date.		 */		if ((int32_t)(tt.tv_sec - zp->z_lastupdate)		    > (int32_t)zp->z_expire) {			dprintf(1, (ddt,				    "stale: secondary zone %s expired\n",				    zp->z_origin));			if (!haveComplained(zp->z_origin, (char*)stale)) {				syslog(LOG_NOTICE,				       "secondary zone \"%s\" expired",				       zp->z_origin);			}			zp->z_flags &= ~Z_AUTH;			needmaint = 1;			return (1);		}		if (zp->z_lastupdate > tt.tv_sec) {			if (!haveComplained(zp->z_origin, (char*)stale)) {				syslog(LOG_NOTICE,				       "secondary zone \"%s\" time warp",				       zp->z_origin);			}			zp->z_flags &= ~Z_AUTH;			needmaint = 1;			return (1);		}		return (0);	case Z_CACHE:		if (dp->d_flags & DB_F_HINT || dp->d_ttl >= tt.tv_sec)			return (0);		dprintf(3, (ddt, "stale: ttl %d %ld (x%lx)\n",			    dp->d_ttl, (long)(dp->d_ttl - tt.tv_sec),			    (u_long)dp->d_flags));		return (1);	default:		/* FALLTHROUGH */ ;	}	panic(-1, "stale: impossible condition");	/* NOTREACHED */}/* * Copy databuf into a resource record for replies. * Return size of RR if OK, -1 if buffer is full. */intmake_rr(name, dp, buf, buflen, doadd)	const char *name;	register struct databuf *dp;	u_char *buf;	int buflen, doadd;{	register u_char *cp;	u_char *cp1, *sp;	struct zoneinfo *zp;	register int32_t n;	register int16_t type = dp->d_type;	register u_int32_t ttl;	u_char **edp = dnptrs + sizeof dnptrs / sizeof dnptrs[0];	dprintf(5, (ddt, "make_rr(%s, %lx, %lx, %d, %d) %d zone %d ttl %lu\n",		    name, (u_long)dp, (u_long)buf,		    buflen, doadd, dp->d_size, dp->d_zone, (u_long)dp->d_ttl));#ifdef	NCACHE	if (dp->d_rcode#ifdef RETURNSOA	    && dp->d_size == 0#endif	) {		panic(-1, "make_rr: impossible d_rcode value");	}#endif	zp = &zones[dp->d_zone];	/* check for outdated RR before updating dnptrs by dn_comp() (?) */	if (zp->z_type == Z_CACHE) {		if ((dp->d_flags & DB_F_HINT) != 0		    || dp->d_ttl < (u_int32_t)tt.tv_sec) {			ttl = 0;		} else			ttl = dp->d_ttl - (u_int32_t) tt.tv_sec;	} else {		if (dp->d_ttl != USE_MINIMUM)			ttl = dp->d_ttl;		else			ttl = zp->z_minimum;		/* really default */#ifdef notdef /* don't decrease ttl based on time since verification */		if (zp->z_type == Z_SECONDARY) {			/*			 * Set ttl to value received from primary,			 * less time since we verified it (but never			 * less than a small positive value).			 */			ttl -= tt.tv_sec - zp->z_lastupdate;			if (ttl <= 0)				ttl = 120;		}#endif	}	buflen -= RRFIXEDSZ;#if defined(RETURNSOA) && defined(NCACHE)	if (dp->d_rcode) {		name = (char *)dp->d_data;		name += strlen(name) +1;		name += strlen(name) +1;		name += 5 * INT32SZ;		type = T_SOA;	}#endif	if ((n = dn_comp(name, buf, buflen, dnptrs, edp)) < 0)		return (-1);	cp = buf + n;	buflen -= n;	PUTSHORT((u_int16_t)type, cp);	PUTSHORT((u_int16_t)dp->d_class, cp);	PUTLONG(ttl, cp);	sp = cp;	cp += INT16SZ;	switch (type) {	case T_CNAME:	case T_MG:	case T_MR:	case T_PTR:		n = dn_comp((char *)dp->d_data, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		PUTSHORT((u_int16_t)n, sp);		cp += n;		break;	case T_MB:	case T_NS:		/* Store domain name in answer */		n = dn_comp((char *)dp->d_data, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		PUTSHORT((u_int16_t)n, sp);		cp += n;		if (doadd)			addname((char*)dp->d_data, name,				type, dp->d_class);		break;	case T_SOA:	case T_MINFO:	case T_RP:		cp1 = dp->d_data;		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		cp += n;		buflen -= type == T_SOA ? n + 5 * INT32SZ : n;		cp1 += strlen((char *)cp1) + 1;		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		cp += n;		if (type == T_SOA) {			cp1 += strlen((char *)cp1) + 1;			bcopy(cp1, cp, (n = 5 * INT32SZ));			cp += n;		}		n = (u_int16_t)((cp - sp) - INT16SZ);		PUTSHORT((u_int16_t)n, sp);		break;	case T_NAPTR:		/* cp1 == our data/ cp == data of RR */		cp1 = dp->d_data; 		if ((buflen -= INT16SZ) < 0)			return (-1); 		/* copy order */ 		bcopy(cp1, cp, INT16SZ); 		cp += INT16SZ; 		cp1 += INT16SZ;		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "current size n = %u\n", n));		/* copy preference */		bcopy(cp1, cp, INT16SZ);		cp += INT16SZ;		cp1 += INT16SZ;		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "current size n = %u\n", n));		/* Flags */		n = *cp1++;		dprintf(1, (ddt, "size of n at flags = %d\n", n));		*cp++ = n;		bcopy(cp1,cp,n);		cp += n;		cp1 += n;		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "current size n = %u\n", n));				/* Service */		n = *cp1++;		*cp++ = n;		bcopy(cp1,cp,n);		cp += n;		cp1 += n;		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "current size n = %u\n", n));		/* Regexp */		n = *cp1++;		*cp++ = n;		bcopy(cp1,cp,n);		cp += n;		cp1 += n;		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "current size n = %u\n", n));		/* Replacement */		dprintf(1, (ddt, "Replacement = %s\n", cp1));		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		dprintf(1, (ddt, "dn_comp's n = %u\n", n));		if (n < 0)			return (-1);		cp += n;		/* save data length */		n = (u_int16_t)((cp - sp) - INT16SZ);		dprintf(1, (ddt, "saved size n = %u\n", n));		PUTSHORT((u_int16_t)n, sp);		break;	case T_MX:	case T_AFSDB:	case T_RT:	case T_SRV:		/* cp1 == our data/ cp == data of RR */		cp1 = dp->d_data; 		if ((buflen -= INT16SZ) < 0)			return (-1); 		/* copy preference */ 		bcopy(cp1, cp, INT16SZ); 		cp += INT16SZ; 		cp1 += INT16SZ;		if (type == T_SRV) {			bcopy(cp1, cp, INT16SZ*2);			cp += INT16SZ*2;			cp1 += INT16SZ*2;		}		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		cp += n;		/* save data length */		n = (u_int16_t)((cp - sp) - INT16SZ);		PUTSHORT((u_int16_t)n, sp);		if (doadd)			addname((char*)cp1, name, type, dp->d_class);		break;	case T_PX:		cp1 = dp->d_data;		if ((buflen -= INT16SZ) < 0)			return (-1);		/* copy preference */		bcopy(cp1, cp, INT16SZ);		cp += INT16SZ;		cp1 += INT16SZ;		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		cp += n;		buflen -= n;		cp1 += strlen((char *)cp1) + 1;		n = dn_comp((char *)cp1, cp, buflen, dnptrs, edp);		if (n < 0)			return (-1);		cp += n;		/* save data length */		n = (u_int16_t)((cp - sp) - INT16SZ);		PUTSHORT((u_int16_t)n, sp);		break;	case T_SIG:		/* cp1 == our data; cp == data of target RR */		cp1 = dp->d_data;		/* first just copy over the type_covered, algorithm, */		/* labels, orig ttl, two timestamps, and the footprint */		if ((dp->d_size - 18) > buflen)			return (-1);  /* out of room! */		bcopy( cp1, cp, 18 );		cp  += 18;		cp1 += 18;		buflen -= 18;		/* then the signer's name */		n = dn_comp((char *)cp1, cp, buflen, NULL, NULL);		if (n < 0)			return (-1);		cp += n;		buflen -= n;		cp1 += strlen((char*)cp1)+1;		/* finally, we copy over the variable-length signature */		n = dp->d_size - (u_int16_t)((cp1 - dp->d_data));		if (n > buflen)			return (-1);  /* out of room! */		bcopy(cp1, cp, n);		cp += n;		  		/* save data length & return */		n = (u_int16_t)((cp - sp) - INT16SZ);  		PUTSHORT((u_int16_t)n, sp);		break;	default:		if (dp->d_size > buflen)			return (-1);		bcopy(dp->d_data, cp, dp->d_size);		PUTSHORT((u_int16_t)dp->d_size, sp);		cp += dp->d_size;	}	return (cp - buf);}#if defined(__STDC__) || defined(__GNUC__)static voidaddname(register const char *dname,	register const char *rname,	u_int16_t rtype,	u_int16_t class)#elsestatic voidaddname(dname, rname, rtype, class)	register const char	*dname;	register const char	*rname;	u_int16_t		rtype;	u_int16_t		class;#endif{	register struct addinfo *ap;	register int n;	for (ap = addinfo, n = addcount; --n >= 0; ap++)		if (strcasecmp(ap->a_dname, dname) == 0)			return;	/* add domain name to additional section */	if (addcount < NADDRECS) {		addcount++;		ap->a_dname = savestr(dname);		ap->a_rname = savestr(rname);		ap->a_rtype = rtype;		ap->a_class = class;	}}/* * Lookup addresses for names in addinfo and put into the message's * additional section. */intdoaddinfo(hp, msg, msglen)	HEADER *hp;	u_char *msg;	int msglen;{	register struct namebuf *np;	register struct databuf *dp;	register struct addinfo *ap;	register u_char *cp;	struct hashbuf *htp;	const char *fname;	int n, count;	if (!addcount)		return (0);	dprintf(3, (ddt, "doaddinfo() addcount = %d\n", addcount));	if (hp->tc) {		dprintf(4, (ddt, "doaddinfo(): tc already set, bailing\n"));		return (0);	}	count = 0;	cp = msg;	for (ap = addinfo; --addcount >= 0; ap++) {		int	foundany = 0,			foundcname = 0,			save_count = count,			save_msglen = msglen;		u_char	*save_cp = cp;		dprintf(3, (ddt, "do additional \"%s\" (from \"%s\")\n",			    ap->a_dname, ap->a_rname));		htp = hashtab;	/* because "nlookup" stomps on arg. */		np = nlookup(ap->a_dname, &htp, &fname, 0);		if (np == NULL || fname != ap->a_dname)			goto next_rr;		dprintf(3, (ddt, "found it\n"));		/* look for the data */		delete_stale(np);		for (dp = np->n_data; dp != NULL; dp = dp->d_next) {#ifdef	NCACHE			if (dp->d_rcode)				continue;#endif			if (match(dp, (int)ap->a_class, T_CNAME) ||			    match(dp, C_IN, T_CNAME)) {				foundcname++;				break;			}			if (!match(dp, (int)ap->a_class, T_A) &&			    !match(dp, C_IN, T_A) &&			    !match(dp, (int)ap->a_class, T_AAAA) &&			    !match(dp, C_IN, T_AAAA)) {				continue;			}			foundany++;			/*			 *  Should be smart and eliminate duplicate			 *  data here.	XXX			 */			if ((n = make_rr(ap->a_dname, dp, cp, msglen, 0)) < 0){				/* truncation in the additional-data section				 * is not all that serious.  we do not set TC,				 * since the answer and authority sections are				 * OK; however, since we're not setting TC we				 * have to make sure that none of the RR's for				 * this name go out (!TC implies that all				 * {name,type} appearances are complete -- and				 * since we only do A RR's here, the name is				 * the key).	vixie, 23apr93				 */				dprintf(5, (ddt,					    "addinfo: not enough room, remaining msglen = %d\n",					    save_msglen));				cp = save_cp;				msglen = save_msglen;				count = save_count;				break;			}			dprintf(5, (ddt,				    "addinfo: adding address data n = %d\n",				    n));			cp += n;			msglen -= n;			count++;		} next_rr:		if (!NoFetchGlue && !foundcname && !foundany) {			/* ask a real server for this info */			(void) sysquery(ap->a_dname, (int)ap->a_class, T_A,					NULL, 0, QUERY);		}		if (foundcname) {			if (!haveComplained((char*)nhash(ap->a_dname),					    (char*)nhash(ap->a_rname))) {				syslog(LOG_DEBUG,				       "\"%s %s %s\" points to a CNAME (%s)",				       ap->a_rname, p_class(ap->a_class),				       p_type(ap->a_rtype), ap->a_dname);			}		}		free(ap->a_dname);		free(ap->a_rname);	}	hp->arcount = htons((u_int16_t)count);	return (cp - msg);}intdoaddauth(hp, cp, buflen, np, dp)	register HEADER *hp;	u_char *cp;	int buflen;	struct namebuf *np;	struct databuf *dp;{	char dnbuf[MAXDNAME];	int n;	getname(np, dnbuf, sizeof(dnbuf));	if (stale(dp)) {		dprintf(1, (ddt,			    "doaddauth: can't add stale '%s' (%d)\n",			    dnbuf, buflen));		return (0);	}	n = make_rr(dnbuf, dp, cp, buflen, 1);	if (n <= 0) {		dprintf(1, (ddt,			    "doaddauth: can't add oversize '%s' (%d) (n=%d)\n",			    dnbuf, buflen, n));		if (n < 0) {			hp->tc = 1;		}		return (0);	}	hp->nscount = htons(ntohs(hp->nscount) + 1);	return (n);}/* * Do a zone transfer (or a recursive part of a zone transfer). * SOA record already sent. * * top always refers to the domain at the top of the zone being transferred. * np refers to a domain inside the zone being transferred, *	which will be equal to top if this is the first call, *	or will be a subdomain below top if this is a recursive call, * rfp is a stdio file to which output is sent. */static voiddoaxfr(np, rfp, top, class)	register struct namebuf *np;	FILE *rfp;	struct namebuf *top;	int class;		/* Class to transfer */{	register struct databuf *dp;	register int n;	struct hashbuf *htp;	struct databuf *gdp;	/* glue databuf */	struct namebuf *gnp;	/* glue namebuf */	struct namebuf *tnp;	/* top namebuf */	struct databuf *tdp;	/* top databuf */	struct namebuf **npp, **nppend;	u_char msg[PACKETSZ];	u_char *cp;	const char *fname;	char dname[MAXDNAME];	HEADER *hp;	int fndns;	if (np == top)		dprintf(1, (ddt, "doaxfr()\n"));	fndns = 0;	bzero((char*)msg, sizeof msg);	hp = (HEADER *) msg;	hp->opcode = QUERY;	hp->qr = 1;	hp->rcode = NOERROR;	hp->ancount = htons(1);	cp = msg + HFIXEDSZ;	getname(np, dname, sizeof dname);	/* first do the NS records (del@harris) */	for (dp = np->n_data; dp != NULL; dp = dp->d_next) {#ifdef GEN_AXFR	    if (dp->d_class != class && class != C_ANY)		continue;#endif#ifdef	    NCACHE	    if (dp->d_rcode)		continue;#endif	    if (dp->d_type == T_NS) {		fndns = 1;		n = make_rr(dname, dp, cp, sizeof(msg)-HFIXEDSZ, 0);		if (n < 0)			continue;		fwritemsg(rfp, msg, n + HFIXEDSZ);#ifdef NO_GLUE		if ((np != top) || (NAME(*top)[0] == '\0')) {#endif /*NO_GLUE*/		    /*  Glue the sub domains together by sending 		     *  the address records for the sub domain		     *  name servers along if necessary.		     *  Glue is necessary if the server is in any zone		     *  delegated from the current (top) zone.  Such		     *  a delegated zone might or might not be that		     *  referred to by the NS record now being handled.		     */ 		    htp = hashtab;		    cp = (u_char *) (msg + HFIXEDSZ); 		    gnp = nlookup((char *)dp->d_data, &htp, &fname, 0); 		    if (gnp == NULL || fname != (char *)dp->d_data) 			continue;#ifdef NO_GLUE		    for (tnp = gnp; tnp != NULL; tnp = tnp->n_parent)			if ( tnp == top )			    break;		    if ( (tnp == NULL) && (NAME(*top)[0] != '\0') )			continue;  /* name server is not below top domain */		    for (tnp = gnp;			 tnp != NULL && tnp != top;			 tnp = tnp->n_parent) {			for (tdp = tnp->n_data;			     tdp != NULL;			     tdp = tdp->d_next) {#ifdef GEN_AXFR			    if (tdp->d_class != class && class != C_ANY)				continue;#endif			    if (tdp->d_type == T_NS)				break;			}			if (tdp != NULL)			    break; /* found a zone cut */		    }		    if ((tnp == top) ||			    ((tnp == NULL) && (NAME(*top)[0] == '\0')))			continue;  /* name server is not in a delegated zone */		    /* now we know glue records are needed.  send them. */#endif /*NO_GLUE*/ 		    for (gdp=gnp->n_data; gdp != NULL; gdp=gdp->d_next) {#ifdef GEN_AXFR			if (gdp->d_class != class && class != C_ANY)			    continue;#endif 			if (gdp->d_type != T_A || stale(gdp)) 			    continue;#ifdef NCACHE			if (gdp->d_rcode)			    continue;#endif 			n = make_rr(fname, gdp, cp, sizeof(msg)-HFIXEDSZ, 0);			if (n < 0)			    continue; 			fwritemsg(rfp, msg, n + HFIXEDSZ); 		    }#ifdef NO_GLUE		}#endif /*NO_GLUE*/	    }	}	/* no need to send anything else if a delegation appeared */	if ((np != top) && fndns)		return;	/* do the rest of the data records */	for (dp = np->n_data; dp != NULL; dp = dp->d_next) {#ifdef GEN_AXFR		if (dp->d_class != class && class != C_ANY)			continue;#endif		/*		 * Skip the top SOA record (marks end of data);		 * don't send SOA for subdomains, as we're not sending them;		 * skip the NS records because we did them first.		 */		if (dp->d_type == T_SOA || dp->d_type == T_NS)			continue;#if 0 /* Not yet implemented.  Only a SHOULD in the I-D.  -gnu@toad.com */		/* skip the SIG AXFR record because we did it first too. */		if (dp->d_type == T_SIG) {			int sig_rrtype = GETSHORT (dp->d_data);			if (sig_rrtype == T_AXFR)				continue;		}#endif /* 0 */		if (dp->d_zone == 0 || stale(dp))			continue;#ifdef NCACHE		if (dp->d_rcode)			continue;#endif		if ((n = make_rr(dname, dp, cp, sizeof(msg)-HFIXEDSZ, 0)) < 0)			continue;		fwritemsg(rfp, msg, n + HFIXEDSZ);	}	/* Finally do non-delegated subdomains.  Delegated subdomains	 * have already been handled.	 */	/*	 * We find the subdomains by looking in the hash table for this	 * domain, but the root domain needs special treatment, because	 * of the following wart in the database design:	 *	 * The top level hash table (pointed to by the global `hashtab'	 * variable) contains pointers to the namebuf's for the root as	 * well as for the top-level domains below the root, in contrast	 * to the usual situation where a hash table contains entries	 * for domains at the same level.  The n_hash member of the	 * namebuf for the root domain is NULL instead of pointing to a	 * hashbuf for the top-level domains.  The n_parent members of	 * the namebufs for the top-level domains are NULL instead of	 * pointing to the namebuf for the root.	 *	 * We work around the wart as follows:	 *	 * If we are not dealing with the root zone then we just set	 * htp = np->n_hash, pointing to the hash table for the current	 * domain, and we walk through the hash table as usual,	 * processing the namebufs for all the subdomains.	 *	 * If we are dealing with the root zone, then we set	 * htp = hashtab, pointing to the global hash table (because	 * there is no hash table associated with the root domain's	 * namebuf.  While we walk this hash table, we take care not to	 * recursively process the entry for the root namebuf.	 *	 * (apb@und nov1990)	 */	htp = ((dname[0] == '\0') ? hashtab : np->n_hash);	if (htp == NULL) {		return; /* no subdomains */	}	npp = htp->h_tab;	nppend = npp + htp->h_size;	while (npp < nppend) {		for (np = *npp++; np != NULL; np = np->n_next) {		    if (NAME(*np)[0] != '\0') { /* don't redo root domain */			doaxfr(np, rfp, top, class);		    }		}	}	if (np == top)		dprintf(1, (ddt, "exit doaxfr()\n"));}static voidstartxfr(qsp, np, soa, soalen, class, dname)	struct qstream	*qsp;	struct namebuf	*np;	u_char		*soa;	int		soalen;	int		class;	const char	*dname;{	FILE *rfp;	int fdstat;	pid_t pid;	int pipefd[2];	char c;#ifdef HAVE_SETVBUF	char *buf;#endif#ifdef SO_SNDBUF	static const int sndbuf = XFER_BUFSIZE * 2;#endif#ifdef SO_LINGER	static const struct linger ll = { 1, 120 };#endif	dprintf(5, (ddt, "startxfr()\n"));	/* create a pipe to synchronize parent and child */	if (pipe(pipefd) != 0) {		syslog(LOG_NOTICE, "startxfr(%s -> %s) failing; pipe: %m",		       dname, sin_ntoa(&qsp->s_from));		sqrm(qsp);		return;	}	/*	 * child does the work while	 * the parent continues	 */	switch (pid = fork()) {	case -1:		syslog(LOG_NOTICE, "startxfr(%s -> %s) failing; fork: %m",		       dname, sin_ntoa(&qsp->s_from));		close(pipefd[0]);		close(pipefd[1]);		sqrm(qsp);		return;	case 0:		/* child */		break;	default:		/* parent */		syslog(LOG_DEBUG, "zone transfer of \"%s\" to %s (pid %lu)",		       dname, sin_ntoa(&qsp->s_from), (u_long)pid);		close(pipefd[0]);	/* close the read end */		sqrm(qsp);		/* close the write end to release the child */		close(pipefd[1]);		return;	}	/*	 * Child.	 *	 * XXX:	this should be a vfork/exec since on non-copy-on-write	 *	systems with huge nameserver images, this is very expensive.	 */	close(vs);	sqflush(/*allbut*/ qsp);	dqflush((time_t)0);	close(pipefd[1]);		/* close the write end */	/*	 * Wait for parent to close the write end of the pipe which	 * we'll see as an EOF.  The parent won't close the write end	 * until it has closed the fd we'll be writing to, at which	 * point it will be safe for us to proceed.         *	 * We shouldn't get interrupted, but ...	 */	while (read(pipefd[0], &c, 1) == -1 && errno == EINTR)		; /* nothing */	close(pipefd[0]);#ifdef RENICE	nice(-40);  nice(20);  nice(0);		/* back to "normal" */#endif	dprintf(5, (ddt, "startxfr: child pid %lu\n", (u_long)pid));	if (!(rfp = fdopen(qsp->s_rfd, "w"))) {		syslog(LOG_ERR, "fdopen: %m");		_exit(1);	}	ns_setproctitle("zone XFR to", qsp->s_rfd);	if (-1 == (fdstat = fcntl(qsp->s_rfd, F_GETFL, 0))) {		syslog(LOG_ERR, "fcntl(F_GETFL): %m");		_exit(1);	}	(void) fcntl(qsp->s_rfd, F_SETFL, fdstat & ~PORT_NONBLOCK);#ifdef HAVE_SETVBUF	/* some systems (DEC OSF/1, SunOS) don't initialize the stdio buffer	 * if all you do between fdopen() and fclose() are fwrite()'s.  even	 * on systems where the buffer is correctly set, it is too small.	 */	if ((buf = malloc(XFER_BUFSIZE)) != NULL)		(void) setvbuf(rfp, buf, _IOFBF, XFER_BUFSIZE);#endif#ifdef SO_SNDBUF	/* the default seems to be 4K, and we'd like it to have enough room	 * to parallelize sending the pushed data with accumulating more	 * write() data from us.	 */	(void) setsockopt(qsp->s_rfd, SOL_SOCKET, SO_SNDBUF,			  (char *)&sndbuf, sizeof sndbuf);#endif	/* XXX:	some day we would like to only send the size and header out	 *	when we fill a 64K DNS/AXFR "message" rather than on each RR.	 *	(PVM@ISI gets credit for this idea.)	 */	fwritemsg(rfp, soa, soalen);	doaxfr(np, rfp, np, class);	fwritemsg(rfp, soa, soalen);	(void) fflush(rfp);#ifdef SO_LINGER	/* kernels that map pages for IO end up failing if the pipe is full	 * at exit and we take away the final buffer.  this is really a kernel	 * bug but it's harmless on systems that are not broken, so...	 */	setsockopt(qsp->s_rfd, SOL_SOCKET, SO_LINGER,		   (char *)&ll, sizeof ll);	close(qsp->s_rfd);#endif	_exit(0);	/* NOTREACHED */}