ns_resp.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 2,318 行 · 第 1/4 页

		hp->arcount = htons((u_short)1);
		tmplen -= authen_rrlen;
		if((authenlen = res_mks_krbcred(ONE, "", "",
					&qp->q_ad,
					tmpmsg, tmpmsg + tmplen,
					BUFSIZ - tmplen,
					dnameptr,
					type_authenrr, class_authenrr))
		    < RET_OK)
			goto servfail;
		tmplen += authenlen;
	}
	(void) send_msg(tmpmsg, tmplen, qp);
	hp->arcount = 0;
	qremove(qp);
	return;

#else AUTHEN
return_msg:
#ifdef STATS
	stats[S_RESPOK].cnt++;
#endif
	/* The "standard" return code */
	hp->qr = 1;
	hp->id = qp->q_id;
	hp->rd = 1;
	hp->ra = 1;
	(void) send_msg(msg, msglen, qp);
	qremove(qp);
	return;

return_newmsg:
#ifdef STATS
	stats[S_RESPOK].cnt++;
#endif
	if (addcount) {
		n = doaddinfo(hp, cp, buflen);
		cp += n;
		buflen -= n;
	}

	hp->id = qp->q_id;
	hp->rd = 1;
	hp->ra = 1;
	hp->qr = 1;
	(void) send_msg(newmsg, cp - newmsg, qp);
	qremove(qp);
	return;

servfail:
#ifdef STATS
	stats[S_RESPFAIL].cnt++;
#endif
	hp = (HEADER *)(cname ? qp->q_cmsg : qp->q_msg);
	hp->rcode = SERVFAIL;
	hp->id = qp->q_id;
	hp->rd = 1;
	hp->ra = 1;
	hp->qr = 1;
	(void) send_msg((char *)hp, (cname ? qp->q_cmsglen : qp->q_msglen), qp);
	qremove(qp);
	return;
#endif AUTHEN

}

/*
 * Decode the resource record 'rrp' and update the database.
 * If savens is true, record pointer for forwarding queries a second time.
 */
#ifdef AUTHEN
doupdate(msg, msglen, rrp, zone, savens, authen_type, authen_ver, flags)
	char *msg ;
	u_char *rrp;
	struct databuf **savens;
	int  msglen, zone, flags;
	int authen_type;
	int authen_ver;
{
#else AUTHEN
doupdate(msg, msglen, rrp, zone, savens, flags)
	char *msg ;
	u_char *rrp;
	struct databuf **savens;
	int  msglen, zone, flags;
{
#endif AUTHEN
	register u_char *cp;
	register int n;
	int class, type, dlen, n1;
	u_long ttl;
	struct databuf *dp;
	char dname[MAXDNAME];
	u_char *cp1;
	u_char data[BUFSIZ];
	register HEADER *hp = (HEADER *) msg;

#ifdef DEBUG
	if (debug > 2)
		fprintf(ddt,"doupdate(zone %d, savens %x, flags %x)\n",
			zone, savens, flags);
#endif

	cp = rrp;
	if ((n = dn_expand(msg, msg + msglen, cp, dname, sizeof(dname))) < 0) {
		hp->rcode = FORMERR;
		return (-1);
	}
	cp += n;
	GETSHORT(type, cp);
	GETSHORT(class, cp);
	GETLONG(ttl, cp);
/*	KLUDGE ALERT This kludge sponsored in part by John Williams and
	brought to you by Bill Brown and a tight field test schedule.
	If this named is running as a slave and the data being placed
	in the database is auth or password info, then set the ttl to two
	minutes.  This will allow a slave to pick up new password info 
	from the database at two minute intervals.
*/
	{ /* begin KLUDGE */
		char *kld_head;
		if((forward_only && fwdtab)) {
			/* We are a slave */

			kld_head = dname;
			res_dotname_rmhead(&kld_head);
			kld_head = res_dotname_head(kld_head);
			if( !strcmp(kld_head, "auth") ||
					!strcmp(kld_head, "passwd"))
				/* this is auth or passwd info */
				ttl = 120;		
		}
	} /* end KLUDGE */
	GETSHORT(dlen, cp);
#ifdef DEBUG
	if (debug > 2)
		fprintf(ddt,"doupdate: dname %s type %d class %d ttl %d\n",
			dname, type, class, ttl);
#endif
	/*
	 * Convert the resource record data into the internal
	 * database format.
	 */
	switch (type) {
	case T_A:
	case T_WKS:
	case T_HINFO:
	case T_UINFO:
	case T_UID:
	case T_GID:
	case T_TXT:
#ifdef ALLOW_T_UNSPEC
	case T_UNSPEC:
#endif ALLOW_T_UNSPEC
		cp1 = cp;
		n = dlen;
		cp += n;
		break;

	case T_CNAME:
	case T_MB:
	case T_MG:
	case T_MR:
	case T_NS:
	case T_PTR:
		if ((n = dn_expand(msg, msg + msglen, cp, data,
		   sizeof(data))) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 = data;
		n = strlen(data) + 1;
		break;

	case T_MINFO:
	case T_SOA:
		if ((n = dn_expand(msg, msg + msglen, cp, data,
		    sizeof(data))) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 = data + (n = strlen(data) + 1);
		n1 = sizeof(data) - n;
		if (type == T_SOA)
			n1 -= 5 * sizeof(u_long);
		if ((n = dn_expand(msg, msg + msglen, cp, cp1, n1)) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 += strlen(cp1) + 1;
		if (type == T_SOA) {
			bcopy(cp, cp1, n = 5 * sizeof(u_long));
			cp += n;
			cp1 += n;
		}
		n = cp1 - data;
		cp1 = data;
		break;

	case T_MX:
		/* grab preference */
		bcopy(cp,data,sizeof(u_short));
		cp1 = data + sizeof(u_short);
		cp += sizeof(u_short);

		/* get name */
		if ((n = dn_expand(msg, msg + msglen, cp, cp1,
		    sizeof(data)-sizeof(u_short))) < 0)
			return(-1);
		cp += n;

		/* compute end of data */
		cp1 += strlen(cp1) + 1;
		/* compute size of data */
		n = cp1 - data;
		cp1 = data;
		break;

	default:
#ifdef DEBUG
		if (debug >= 3)
			fprintf(ddt,"unknown type %d\n", type);
#endif
		return ((cp - rrp) + dlen);
	}
	if (n > MAXDATA) {
#ifdef DEBUG
		if (debug)
		    fprintf(ddt,
			"update type %d: %d bytes is too much data\n",
			type, n);
#endif
		hp->rcode = NOCHANGE;	/* XXX - FORMERR ??? */
		return(-1);
	}

#ifdef ALLOW_UPDATES
	/*
	 * If this is a dynamic update request, process it specially; else,
	 * execute normal update code.
	 */
	switch(opcode) {

	/* For UPDATEM and UPDATEMA, do UPDATED/UPDATEDA followed by UPDATEA */
	case UPDATEM:
	case UPDATEMA:

	/*
	 * The named code for UPDATED and UPDATEDA is the same except that for
	 * UPDATEDA we we ignore any data that was passed: we just delete all
	 * RRs whose name, type, and class matches
	 */
	case UPDATED:
	case UPDATEDA:
		if (type == T_SOA) {	/* Not allowed */
#ifdef DEBUG
			if (debug)
			   fprintf(ddt, "UDPATE: REFUSED - SOA delete\n");
#endif
			hp->rcode = REFUSED;
			return(-1);
		}
		/*
		 * Don't check message length if doing UPDATEM/UPDATEMA,
		 * since the whole message wont have been demarshalled until
		 * we reach the code for UPDATEA
		 */
		if ( (opcode == UPDATED) || (opcode == UPDATEDA) ) {
			if (cp != msg + msglen) {
#ifdef DEBUG
			    if (debug)
			        fprintf(ddt,"FORMERR UPDATE message length off\n");
#endif
			    hp->rcode = FORMERR;
			    return(-1);
			}
		}
		if ((zonenum = findzone(dname, class)) == 0) { 
			hp->rcode = NXDOMAIN;
			return(-1);
		}
		if ( (opcode == UPDATED) || (opcode == UPDATEM) ) {
			/* Make a dp for use in db_update, as old dp */
			dp = savedata(class, type, 0, cp1, n);
			dp->d_zone = zonenum;
			n = db_update(dname, dp, NULL, DB_MEXIST | DB_DELETE,
				      hashtab);
			if (n != OK) {
#ifdef DEBUG
				if (debug)
				    fprintf(ddt,"UPDATE: db_update failed\n");
#endif DEBUG
				free( (struct databuf *) dp);
				hp->rcode = NOCHANGE;
				return(-1);
			}
		} else {	/* UPDATEDA or UPDATEMA */
			int DeletedOne = 0;
			/* Make a dp for use in db_update, as old dp */
			dp = savedata(class, type, 0, NULL, 0);
			dp->d_zone = zonenum;
			do {	/* Loop and delete all matching RR(s) */
				n = db_update(dname, dp, NULL, DB_DELETE,
					      hashtab);
				if (n != OK)
					break;
				DeletedOne++;
			} while (1);
			free( (struct databuf *) dp);
			/* Ok for UPDATEMA not to have deleted any RRs */
			if (!DeletedOne && opcode == UPDATEDA) {
#ifdef DEBUG
				if (debug)
					fprintf(ddt,"UPDATE: db_update failed\n");
#endif DEBUG
				hp->rcode = NOCHANGE;
				return(-1);
			}
		}
		if ( (opcode == UPDATED) || (opcode == UPDATEDA) )
			return (cp - rrp);;
		/*
		 * Else unmarshal the RR to be added and continue on to
		 * UPDATEA code for UPDATEM/UPDATEMA
		 */
		if ((n =
		   dn_expand(msg, msg+msglen, cp, dname, sizeof(dname))) < 0) {
#ifdef DEBUG
			if (debug)
			    fprintf(ddt,"FORMERR UPDATE expand name failed\n");
#endif
			hp->rcode = FORMERR;
			return(-1);
		}
		cp += n;
		GETSHORT(type, cp);
		GETSHORT(class, cp);
		GETLONG(ttl, cp);
		GETSHORT(n, cp);
		cp1 = cp;
/**** XXX - need bounds checking here ****/
		cp += n;

	case UPDATEA:
		if (n > MAXDATA) {
#ifdef DEBUG
			if (debug)
			    fprintf(ddt,"UPDATE: too much data\n");
#endif
			hp->rcode = NOCHANGE;
			return(-1);
		}
		if (cp != msg + msglen) {
#ifdef DEBUG
			if (debug)
			    fprintf(ddt,"FORMERR UPDATE message length off\n");
#endif
			hp->rcode = FORMERR;
			return(-1);
		}
		if ((zonenum = findzone(dname, class)) == 0) { 
			hp->rcode = NXDOMAIN;
			return(-1);
		}
		dp = savedata(class, type, ttl, cp1, n);
		dp->d_zone = zonenum;
		if ((n = db_update(dname, NULL, dp, DB_NODATA,
				   hashtab)) != OK) {
#ifdef DEBUG
			if (debug)
				fprintf(ddt,"UPDATE: db_update failed\n");
#endif
			hp->rcode = NOCHANGE;
			return (-1);
		}
		else
			return (cp - rrp);
	}
#endif ALLOW_UPDATES

	if (zone == 0)
		ttl += tt.tv_sec;
#ifdef AUTHEN
	dp = savedata(class, type, ttl, authen_type, authen_ver, cp1, n);
#else AUTHEN
	dp = savedata(class, type, ttl, cp1, n);
#endif AUTHEN
	dp->d_zone = zone;
	if ((n = db_update(dname, dp, dp, flags, hashtab)) < 0) {
#ifdef DEBUG
		if (debug && (n != DATAEXISTS))
			fprintf(ddt,"update failed (%d)\n", n);
		else if (debug >= 3)
			fprintf(ddt,"update failed (DATAEXISTS)\n");
#endif
		(void) free((char *)dp);
	} else if (type == T_NS && savens != NULL)
		*savens = dp;
	return (cp - rrp);
}

send_msg(msg, msglen, qp)
	char *msg;
	int msglen;
	struct qinfo *qp;
{
	extern struct qinfo *qhead;
#ifdef DEBUG
	struct qinfo *tqp;
#endif DEBUG

	if (qp->q_system)
		return(1);
#ifdef DEBUG
	if (debug) {
		fprintf(ddt,"send_msg -> %s (%s %d %d) id=%d\n",
			inet_ntoa(qp->q_from.sin_addr), 
			qp->q_stream == QSTREAM_NULL ? "UDP" : "TCP", qp->q_dfd,
			ntohs(qp->q_from.sin_port),
			ntohs(qp->q_id));
	}
	if (debug>4)
		for (tqp = qhead; tqp!=QINFO_NULL; tqp = tqp->q_link) {
		    fprintf(ddt, "qp %x q_id: %d  q_nsid: %d q_msglen: %d ",
		    	tqp, tqp->q_id,tqp->q_nsid,tqp->q_msglen);
	            fprintf(ddt,"q_naddr: %d q_curaddr: %d\n", tqp->q_naddr,
			tqp->q_curaddr);
	            fprintf(ddt,"q_next: %x q_link: %x\n", qp->q_next,
		   	 qp->q_link);
		}
	if (debug >= 10)
		fp_query(msg, ddt);
#endif DEBUG
	if (qp->q_stream == QSTREAM_NULL) {
		if (sendto(qp->q_dfd, msg, msglen, 0,
		    (struct sockaddr *)&qp->q_from, sizeof(qp->q_from)) < 0) {
#ifdef DEBUG
			if (debug)
				fprintf(ddt, "sendto error errno= %d\n",errno);
#endif
			return(1);
		}
#ifdef STATS
		stats[S_OUTPKTS].cnt++;
#endif
	} else {
		(void) writemsg(qp->q_stream->s_rfd, msg, msglen);
		qp->q_stream->s_time = tt.tv_sec;
		qp->q_stream->s_refcnt--;
	}
	return(0);
}

prime(class, type, oqp)
	int class, type;
	register struct qinfo *oqp;
{
	char	dname[BUFSIZ];

	if (oqp->q_msg == NULL)
		return;
	if (dn_expand(oqp->q_msg, oqp->q_msg + oqp->q_msglen,
	    oqp->q_msg + sizeof(HEADER), dname, sizeof(dname)) < 0)
		return;
#ifdef DEBUG
	if (debug >= 2)
	       fprintf(ddt,"prime: %s\n", dname);
#endif
	(void) sysquery(dname, class, type);
}


prime_cache()
{
	register struct qinfo *qp;

#ifdef DEBUG
	if (debug)
		fprintf(ddt,"prime_cache: priming = %d\n", priming);
#endif
#ifdef STATS
	stats[S_PRIMECACHE].cnt++;
#endif
	if (!priming && fcachetab->h_tab[0] != NULL) {
		priming++;
		if ((qp = sysquery("", C_IN, T_NS)) == NULL)
			priming = 0;
		else
			qp->q_system = PRIMING_CACHE;
	}
	needs_prime_cache = 0;
	return;
}

struct qinfo *
sysquery(dname, class, type)
	char *dname;
	int class, type;
{
	extern struct qinfo *qhead;
	extern int nsid;
	register struct qinfo *qp, *oqp;
	register HEADER *hp;
	struct namebuf *np;
	struct databuf *nsp[NSMAX];
	struct hashbuf *htp;
	char *fname;
	int count;
#ifdef AUTHEN
	char *krbnameptr;
	char *dnameptr;
	int authenlen;
	int msglen;
#endif AUTHEN

#ifdef DEBUG
	if (debug > 2)
	       fprintf(ddt,"sysquery(%s, %d, %d)\n", dname, class, type);
#endif
#ifdef STATS
	stats[S_SYSQUERIES].cnt++;
#endif
	htp = hashtab;
	if (priming && dname[0] == '\0')
		np = NULL;
	else if ((np = nlookup(dname, &htp, &fname, 1)) == NULL) {
#ifdef DEBUG
		if (debug)
			fprintf(ddt,"sysquery: nlookup error on %s?\n", dname);
#endif
		return(0);
	}

	switch (findns(&np, class, nsp, &count)) {
	case NXDOMAIN:
	case SERVFAIL:
#ifdef DEBUG
		if (debug)
			fprintf(ddt,"sysquery: findns error on %s?\n", dname);
#endif
		return(0);
	}

	/* build new qinfo struct */
	qp = qnew();
	qp->q_cmsg = qp->q_msg = NULL;
	qp->q_dfd = ds;
	qp->q_fwd = fwdtab;
	qp->q_addr[0].stime = tt;
	qp->q_system++;

#ifdef AUTHEN
	strcpy(qp->q_dname, dname);
	qp->q_type = type;
	qp->q_class = class;
	strcpy(qp->q_dname_curr, dname);
	qp->q_type_curr = type;
	qp->q_class_curr = class;
	if(netsafe && class == C_HS) {
		qp->q_type_in = AQUERY;
		qp->q_type_out = AQUERY;
		qp->q_authentype_in = AUTH_KRB;
		qp->q_authenver_in = ONE;
		qp->q_authentype_out = AUTH_KRB;
		qp->q_authenver_out = ONE;
	} else {
		qp->q_type_in = QUERY;
		qp->q_type_out = QUERY;
		qp->q_authentype_in = AUTH_NONE;
		qp->q_authenver_in = ZERO;
		qp->q_authentype_out = AUTH_NONE;
		qp->q_authenver_out = ZERO;
	}		
#endif AUTHEN

	if ((qp->q_msg = malloc(BUFSIZ)) == NULL) {
		qfree(qp);