[thirdparty/dhcp.git] / minires / res_findzonecut.c

#if !defined(lint) && !defined(SABER)
static const char rcsid[] = "$Id: res_findzonecut.c,v 1.15 2001/06/27 00:30:34 mellon Exp $";
#endif /* not lint */

/*
 * Copyright (c) 1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/* Import. */

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#include <errno.h>
#include <limits.h>
#include <netdb.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <isc-dhcp/list.h>

#include "minires/minires.h"
#include "arpa/nameser.h"

/* Data structures. */

typedef struct rr_a {
	ISC_LINK(struct rr_a)	link;
	struct in_addr		addr;
} rr_a;
typedef ISC_LIST(rr_a) rrset_a;

typedef struct rr_ns {
	ISC_LINK(struct rr_ns) link;
	char *name;
	rrset_a addrs;
} rr_ns;
typedef ISC_LIST(rr_ns) rrset_ns;

/* Forward. */

static int	satisfy(res_state,
			const char *, rrset_ns *, struct in_addr *, int);
static int	add_addrs(res_state, rr_ns *, struct in_addr *, int);
static ns_rcode	get_soa(res_state, const char *, ns_class,
			char *, size_t, char *, size_t,
			rrset_ns *);
static isc_result_t get_ns(res_state, const char *, ns_class, rrset_ns *);
static isc_result_t get_glue(res_state, ns_class, rrset_ns *);
static isc_result_t save_ns(res_state, ns_msg *, ns_sect,
			    const char *, ns_class, rrset_ns *);
static isc_result_t save_a(res_state, ns_msg *, ns_sect,
			   const char *, ns_class, rrset_a *);
static void	free_nsrrset(rrset_ns *);
static void	free_nsrr(rrset_ns *, rr_ns *);
static rr_ns *	find_ns(rrset_ns *, const char *);
static isc_result_t do_query(res_state, const char *, ns_class, ns_type,
			     double *, ns_msg *, int *);

/* Public. */

/*
 * int
 * res_findzonecut(res, dname, class, zname, zsize, addrs, naddrs)
 *	find enclosing zone for a <dname,class>, and some server addresses
 * parameters:
 *	res - resolver context to work within (is modified)
 *	dname - domain name whose enclosing zone is desired
 *	class - class of dname (and its enclosing zone)
 *	zname - found zone name
 *	zsize - allocated size of zname
 *	addrs - found server addresses
 *	naddrs - max number of addrs
 * return values:
 *	< 0 - an error occurred (check errno)
 *	= 0 - zname is now valid, but addrs[] wasn't changed
 *	> 0 - zname is now valid, and return value is number of addrs[] found
 * notes:
 *	this function calls res_nsend() which means it depends on correctly
 *	functioning recursive nameservers (usually defined in /etc/resolv.conf
 *	or its local equivilent).
 *
 *	we start by asking for an SOA<dname,class>.  if we get one as an
 *	answer, that just means <dname,class> is a zone top, which is fine.
 *	more than likely we'll be told to go pound sand, in the form of a
 *	negative answer.
 *
 *	note that we are not prepared to deal with referrals since that would
 *	only come from authority servers and our correctly functioning local
 *	recursive server would have followed the referral and got us something
 *	more definite.
 *
 *	if the authority section contains an SOA, this SOA should also be the
 *	closest enclosing zone, since any intermediary zone cuts would've been
 *	returned as referrals and dealt with by our correctly functioning local
 *	recursive name server.  but an SOA in the authority section should NOT
 *	match our dname (since that would have been returned in the answer
 *	section).  an authority section SOA has to be "above" our dname.
 *
 *	we cannot fail to find an SOA in this way.  ultimately we'll return
 *	a zname indicating the root zone if that's the closest enclosing zone.
 *	however, since authority section SOA's were once optional, it's
 *	possible that we'll have to go hunting for the enclosing SOA by
 *	ripping labels off the front of our dname -- this is known as "doing
 *	it the hard way."
 *
 *	ultimately we want some server addresses, which are ideally the ones
 *	pertaining to the SOA.MNAME, but only if there is a matching NS RR.
 *	so the second phase (after we find an SOA) is to go looking for the
 *	NS RRset for that SOA's zone.
 *
 *	no answer section processed by this code is allowed to contain CNAME
 *	or DNAME RR's.  for the SOA query this means we strip a label and
 *	keep going.  for the NS and A queries this means we just give up.
 */

isc_result_t
res_findzonecut(res_state statp, const char *dname, ns_class class, int opts,
		char *zname, size_t zsize, struct in_addr *addrs, int naddrs,
		int *count, void *zcookie)
{
	char mname[NS_MAXDNAME];
	u_long save_pfcode;
	rrset_ns nsrrs;
	int n = 0;
	isc_result_t rcode;

	DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d",
		 dname, p_class(class), (long)zsize, naddrs));
	save_pfcode = statp->pfcode;
	statp->pfcode |= RES_PRF_HEAD2 | RES_PRF_HEAD1 | RES_PRF_HEADX |
			 RES_PRF_QUES | RES_PRF_ANS |
			 RES_PRF_AUTH | RES_PRF_ADD;
	ISC_LIST_INIT(nsrrs);

	DPRINTF (("look for a predefined zone statement"));
	rcode = find_cached_zone (dname, class, zname, zsize,
				  addrs, naddrs, &n, zcookie);
	if (rcode == ISC_R_SUCCESS)
		goto done;

	DPRINTF(("get the soa, and see if it has enough glue"));
	if ((rcode = get_soa(statp, dname, class, zname, zsize,
			     mname, sizeof mname, &nsrrs)) != ISC_R_SUCCESS ||
	    ((opts & RES_EXHAUSTIVE) == 0 &&
	     (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
		goto done;

	DPRINTF(("get the ns rrset and see if it has enough glue"));
	if ((rcode = get_ns(statp, zname, class, &nsrrs)) != ISC_R_SUCCESS ||
	    ((opts & RES_EXHAUSTIVE) == 0 &&
	     (n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
		goto done;

	DPRINTF(("get the missing glue and see if it's finally enough"));
	if ((rcode = get_glue(statp, class, &nsrrs)) == ISC_R_SUCCESS)
		n = satisfy(statp, mname, &nsrrs, addrs, naddrs);

	/* If we found the zone, cache it. */
	if (n > 0)
		cache_found_zone (class, zname, addrs, n);
 done:
	DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK"));
	free_nsrrset(&nsrrs);
	statp->pfcode = save_pfcode;
	if (count)
		*count = n;
	return rcode;
}

/* Private. */

static int
satisfy(res_state statp,
	const char *mname, rrset_ns *nsrrsp, struct in_addr *addrs, int naddrs)
{
	rr_ns *nsrr;
	int n, x;

	n = 0;
	nsrr = find_ns(nsrrsp, mname);
	if (nsrr != NULL) {
		x = add_addrs(statp, nsrr, addrs, naddrs);
		addrs += x;
		naddrs -= x;
		n += x;
	}
	for (nsrr = ISC_LIST_HEAD(*nsrrsp);
	     nsrr != NULL && naddrs > 0;
	     nsrr = ISC_LIST_NEXT(nsrr, link))
		if (ns_samename(nsrr->name, mname) != 1) {
			x = add_addrs(statp, nsrr, addrs, naddrs);
			addrs += x;
			naddrs -= x;
			n += x;
		}
	DPRINTF(("satisfy(%s): %d", mname, n));
	return (n);
}

static int
add_addrs(res_state statp, rr_ns *nsrr, struct in_addr *addrs, int naddrs) {
	rr_a *arr;
	int n = 0;

	for (arr = ISC_LIST_HEAD(nsrr->addrs);
	     arr != NULL; arr = ISC_LIST_NEXT(arr, link)) {
		if (naddrs <= 0)
			return (0);
		*addrs++ = arr->addr;
		naddrs--;
		n++;
	}
	DPRINTF(("add_addrs: %d", n));
	return (n);
}

static ns_rcode
get_soa(res_state statp, const char *dname, ns_class class,
	char *zname, size_t zsize, char *mname, size_t msize,
	rrset_ns *nsrrsp)
{
	char tname[NS_MAXDNAME];
	double resp[NS_PACKETSZ / sizeof (double)];
	int n, i, ancount, nscount;
	ns_sect sect;
	ns_msg msg;
	u_int rcode;
	isc_result_t status;

	/*
	 * Find closest enclosing SOA, even if it's for the root zone.
	 */

	/* First canonicalize dname (exactly one unescaped trailing "."). */
	status = ns_makecanon(dname, tname, sizeof tname);
	if (status != ISC_R_SUCCESS)
		return status;
	dname = tname;

	/* Now grovel the subdomains, hunting for an SOA answer or auth. */
	for (;;) {
		/* Leading or inter-label '.' are skipped here. */
		while (*dname == '.')
			dname++;

		/* Is there an SOA? */
		rcode = do_query(statp, dname, class, ns_t_soa,
				 resp, &msg, &n);
		if (rcode != ISC_R_SUCCESS) {
			DPRINTF(("get_soa: do_query('%s', %s) failed (%d)",
				 dname, p_class(class), n));
			return rcode;
		}
		if (n > 0) {
			DPRINTF(("get_soa: CNAME or DNAME found"));
			sect = ns_s_max, n = 0;
		} else {
			ancount = ns_msg_count(msg, ns_s_an);
			nscount = ns_msg_count(msg, ns_s_ns);
			if (ancount > 0 && rcode == ISC_R_SUCCESS)
				sect = ns_s_an, n = ancount;
			else if (nscount > 0)
				sect = ns_s_ns, n = nscount;
			else
				sect = ns_s_max, n = 0;
		}
		for (i = 0; i < n; i++) {
			const char *t;
			const u_char *rdata;
			int rdlen;
			ns_rr rr;

			rcode = ns_parserr(&msg, sect, i, &rr) < 0;
			if (rcode != ISC_R_SUCCESS) {
				DPRINTF(("get_soa: ns_parserr(%s, %d) failed",
					 p_section(sect, ns_o_query), i));
				return rcode;
			}
			if (ns_rr_type(rr) == ns_t_cname ||
			    ns_rr_type(rr) == ns_t_dname)
				break;
			if (ns_rr_type(rr) != ns_t_soa ||
			    ns_rr_class(rr) != class)
				continue;
			t = ns_rr_name(rr);
			switch (sect) {
			case ns_s_an:
				if (ns_samedomain(dname, t) == 0) {
					DPRINTF(("get_soa: %s'%s', '%s') == 0",
						 "ns_samedomain(", dname, t));
					return ISC_R_NOTZONE;
				}
				break;
			case ns_s_ns:
				if (ns_samename(dname, t) == 1 ||
				    ns_samedomain(dname, t) == 0) {
					DPRINTF(("get_soa: %smain('%s', '%s')",
						 "ns_samename() || !ns_samedo",
						 dname, t));
					return ISC_R_NOTZONE;
				}
				break;
			default:
				abort();
			}
			if (strlen(t) + 1 > zsize) {
				DPRINTF(("get_soa: zname(%d) too small (%d)",
					 zsize, strlen(t) + 1));
				return ISC_R_NOSPACE;
			}
			strcpy(zname, t);
			rdata = ns_rr_rdata(rr);
			rdlen = ns_rr_rdlen(rr);
			if (ns_name_uncompress((u_char *)resp,
					       ns_msg_end(msg), rdata,
					       mname, msize) < 0) {
				DPRINTF(("get_soa: %s failed",
					 "ns_name_uncompress"));
				return ISC_R_NOMEMORY;
			}
			rcode = save_ns(statp, &msg,
					ns_s_ns, zname, class, nsrrsp);
			if (rcode != ISC_R_SUCCESS) {
				DPRINTF(("get_soa: save_ns failed"));
				return rcode;
			}
			return ISC_R_SUCCESS;
		}

		/* If we're out of labels, then not even "." has an SOA! */
		if (*dname == '\0')
			break;

		/* Find label-terminating "."; top of loop will skip it. */
		while (*dname != '.') {
			if (*dname == '\\')
				if (*++dname == '\0') {
					ISC_R_NOSPACE;
				}
			dname++;
		}
	}
	DPRINTF(("get_soa: out of labels"));
	return ISC_R_DESTADDRREQ;
}

static isc_result_t
get_ns(res_state statp, const char *zname, ns_class class, rrset_ns *nsrrsp) {
	double resp[NS_PACKETSZ / sizeof (double)];
	ns_msg msg;
	int n;
	isc_result_t rcode;

	/* Go and get the NS RRs for this zone. */
	rcode = do_query(statp, zname, class, ns_t_ns, resp, &msg, &n);
	if (rcode != ISC_R_SUCCESS) {
		DPRINTF(("get_ns: do_query('zname', %s) failed (%d)",
			 zname, p_class(class), rcode));
		return rcode;
	}

	/* Remember the NS RRs and associated A RRs that came back. */
	rcode = save_ns(statp, &msg, ns_s_an, zname, class, nsrrsp);
	if (rcode != ISC_R_SUCCESS) {
		DPRINTF(("get_ns save_ns('%s', %s) failed",
			 zname, p_class(class)));
		return rcode;
	}

	return ISC_R_SUCCESS;
}

static isc_result_t
get_glue(res_state statp, ns_class class, rrset_ns *nsrrsp) {
	rr_ns *nsrr, *nsrr_n;

	/* Go and get the A RRs for each empty NS RR on our list. */
	for (nsrr = ISC_LIST_HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
		double resp[NS_PACKETSZ / sizeof (double)];
		ns_msg msg;
		int n;
		isc_result_t rcode;

		nsrr_n = ISC_LIST_NEXT(nsrr, link);

		if (ISC_LIST_EMPTY(nsrr->addrs)) {
			rcode = do_query(statp, nsrr->name, class, ns_t_a,
					 resp, &msg, &n);
			if (rcode != ISC_R_SUCCESS) {
			    DPRINTF(("get_glue: do_query('%s', %s') failed",
				     nsrr->name, p_class(class)));
			    return rcode;
			}
			if (n > 0) {
				DPRINTF((
			"get_glue: do_query('%s', %s') CNAME or DNAME found",
					 nsrr->name, p_class(class)));
			}
			rcode = save_a(statp, &msg, ns_s_an, nsrr->name, class,
				       &nsrr->addrs);
			if (rcode != ISC_R_SUCCESS) {
				DPRINTF(("get_glue: save_r('%s', %s) failed",
					 nsrr->name, p_class(class)));
				return rcode;
			}
			/* If it's still empty, it's just chaff. */
			if (ISC_LIST_EMPTY(nsrr->addrs)) {
				DPRINTF(("get_glue: removing empty '%s' NS",
					 nsrr->name));
				free_nsrr(nsrrsp, nsrr);
			}
		}
	}
	return ISC_R_SUCCESS;
}

static isc_result_t
save_ns(res_state statp, ns_msg *msg, ns_sect sect,
	const char *owner, ns_class class,
	rrset_ns *nsrrsp)
{
	int i;
	isc_result_t rcode;

	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
		char tname[MAXDNAME];
		const u_char *rdata;
		rr_ns *nsrr;
		ns_rr rr;
		int rdlen;

		rcode = ns_parserr(msg, sect, i, &rr);
		if (rcode != ISC_R_SUCCESS) {
			DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
				 p_section(sect, ns_o_query), i));
			return rcode;
		}
		if (ns_rr_type(rr) != ns_t_ns ||
		    ns_rr_class(rr) != class ||
		    ns_samename(ns_rr_name(rr), owner) != 1)
			continue;
		nsrr = find_ns(nsrrsp, ns_rr_name(rr));
		if (nsrr == NULL) {
			nsrr = malloc(sizeof *nsrr);
			if (nsrr == NULL) {
				DPRINTF(("save_ns: malloc failed"));
				return ISC_R_NOMEMORY;
			}
			rdata = ns_rr_rdata(rr);
			rdlen = ns_rr_rdlen(rr);
			if (ns_name_uncompress(ns_msg_base(*msg),
					       ns_msg_end(*msg), rdata,
					       tname, sizeof tname) < 0) {
				DPRINTF(("save_ns: ns_name_uncompress failed"));
				free(nsrr);
				return ISC_R_NOMEMORY;
			}
			nsrr->name = strdup(tname);
			if (nsrr->name == NULL) {
				DPRINTF(("save_ns: strdup failed"));
				free(nsrr);
				return ISC_R_NOMEMORY;
			}
			ISC_LIST_INIT(nsrr->addrs);
			ISC_LIST_APPEND(*nsrrsp, nsrr, link);
		}
		rcode = save_a(statp, msg, ns_s_ar,
			       nsrr->name, class, &nsrr->addrs);
		if (rcode != ISC_R_SUCCESS) {
			DPRINTF(("save_ns: save_r('%s', %s) failed",
				 nsrr->name, p_class(class)));
			return rcode;
		}
	}
	return ISC_R_SUCCESS;
}

static isc_result_t
save_a(res_state statp, ns_msg *msg, ns_sect sect,
       const char *owner, ns_class class,
       rrset_a *arrsp)
{
	int i;
	isc_result_t rcode;

	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
		ns_rr rr;
		rr_a *arr;

		rcode = ns_parserr(msg, sect, i, &rr);
		if (rcode != ISC_R_SUCCESS) {
			DPRINTF(("save_a: ns_parserr(%s, %d) failed",
				 p_section(sect, ns_o_query), i));
			return rcode;
		}
		if (ns_rr_type(rr) != ns_t_a ||
		    ns_rr_class(rr) != class ||
		    ns_samename(ns_rr_name(rr), owner) != 1 ||
		    ns_rr_rdlen(rr) != NS_INADDRSZ)
			continue;
		arr = malloc(sizeof *arr);
		if (arr == NULL) {
			DPRINTF(("save_a: malloc failed"));
			return ISC_R_NOMEMORY;
		}
		memcpy(&arr->addr, ns_rr_rdata(rr), NS_INADDRSZ);
		ISC_LIST_APPEND(*arrsp, arr, link);
	}
	return ISC_R_SUCCESS;
}

static void
free_nsrrset(rrset_ns *nsrrsp) {
	rr_ns *nsrr;

	while ((nsrr = ISC_LIST_HEAD(*nsrrsp)) != NULL)
		free_nsrr(nsrrsp, nsrr);
}

static void
free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) {
	rr_a *arr;

	while ((arr = ISC_LIST_HEAD(nsrr->addrs)) != NULL) {
		ISC_LIST_UNLINK(nsrr->addrs, arr, link);
		free(arr);
	}
	free((char *)nsrr->name);
	ISC_LIST_UNLINK(*nsrrsp, nsrr, link);
	free(nsrr);
}

static rr_ns *
find_ns(rrset_ns *nsrrsp, const char *dname) {
	rr_ns *nsrr;

	for (nsrr = ISC_LIST_HEAD(*nsrrsp);
	     nsrr != NULL; nsrr = ISC_LIST_NEXT(nsrr, link))
		if (ns_samename(nsrr->name, dname) == 1)
			return (nsrr);
	return (NULL);
}

static isc_result_t
do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
	 double *resp, ns_msg *msg, int *alias_count)
{
	double req[NS_PACKETSZ / sizeof (double)];
	int i;
	unsigned n;
	isc_result_t status;

	status = res_nmkquery(statp, ns_o_query, dname, class, qtype,
			      NULL, 0, NULL, req, NS_PACKETSZ, &n);
	if (status != ISC_R_SUCCESS) {
		DPRINTF(("do_query: res_nmkquery failed"));
		return status;
	}
	status = res_nsend(statp, req, n, resp, NS_PACKETSZ, &n);
	if (status != ISC_R_SUCCESS) {
		DPRINTF(("do_query: res_nsend failed"));
		return status;
	}
	if (n == 0) {
		DPRINTF(("do_query: res_nsend returned 0"));
		return ISC_R_NOTFOUND;
	}
	if (ns_initparse((u_char *)resp, n, msg) < 0) {
		DPRINTF(("do_query: ns_initparse failed"));
		return ISC_R_NOSPACE;
	}
	n = 0;
	for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
		ns_rr rr;

		status = ns_parserr(msg, ns_s_an, i, &rr);
		if (status != ISC_R_SUCCESS) {
			DPRINTF(("do_query: ns_parserr failed"));
			return status;
		}
		n += (ns_rr_class(rr) == class &&
		      (ns_rr_type(rr) == ns_t_cname ||
		       ns_rr_type(rr) == ns_t_dname));
	}
	if (alias_count)
		*alias_count = n;
	return ISC_R_SUCCESS;
}
Commit	Line	Data
3997081b	1	#if !defined(lint) && !defined(SABER)
d758ad8c	2	static const char rcsid[] = "$Id: res_findzonecut.c,v 1.15 2001/06/27 00:30:34 mellon Exp $";
3997081b TL	3	#endif /* not lint */
	4
	5	/*
	6	* Copyright (c) 1999 by Internet Software Consortium.
	7	*
	8	* Permission to use, copy, modify, and distribute this software for any
	9	* purpose with or without fee is hereby granted, provided that the above
	10	* copyright notice and this permission notice appear in all copies.
	11	*
	12	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
	13	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
	14	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
	15	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	16	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	17	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	18	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	19	* SOFTWARE.
	20	*/
	21
	22	/* Import. */
	23
	24	#include <sys/param.h>
	25	#include <sys/socket.h>
	26	#include <sys/time.h>
	27
	28	#include <netinet/in.h>
	29	#include <arpa/inet.h>
	30
	31	#include <errno.h>
	32	#include <limits.h>
	33	#include <netdb.h>
	34	#include <stdarg.h>
	35	#include <stdio.h>
	36	#include <stdlib.h>
	37	#include <string.h>
	38
d758ad8c	39	#include <isc-dhcp/list.h>
3997081b	40
3997081b	41	#include "minires/minires.h"
439a9b00	42	#include "arpa/nameser.h"
3997081b TL	43
	44	/* Data structures. */
	45
	46	typedef struct rr_a {
	47	ISC_LINK(struct rr_a) link;
	48	struct in_addr addr;
	49	} rr_a;
	50	typedef ISC_LIST(rr_a) rrset_a;
	51
	52	typedef struct rr_ns {
	53	ISC_LINK(struct rr_ns) link;
	54	char *name;
	55	rrset_a addrs;
	56	} rr_ns;
	57	typedef ISC_LIST(rr_ns) rrset_ns;
	58
	59	/* Forward. */
	60
	61	static int satisfy(res_state,
	62	const char , rrset_ns , struct in_addr *, int);
	63	static int add_addrs(res_state, rr_ns , struct in_addr , int);
233b79e1	64	static ns_rcode get_soa(res_state, const char *, ns_class,
3997081b TL	65	char , size_t, char , size_t,
3997081b TL	66	rrset_ns *);
5abf0a44 TL	67	static isc_result_t get_ns(res_state, const char , ns_class, rrset_ns );
	68	static isc_result_t get_glue(res_state, ns_class, rrset_ns *);
	69	static isc_result_t save_ns(res_state, ns_msg *, ns_sect,
	70	const char , ns_class, rrset_ns );
	71	static isc_result_t save_a(res_state, ns_msg *, ns_sect,
	72	const char , ns_class, rrset_a );
3997081b TL	73	static void free_nsrrset(rrset_ns *);
	74	static void free_nsrr(rrset_ns , rr_ns );
	75	static rr_ns * find_ns(rrset_ns , const char );
6cff8371 TL	76	static isc_result_t do_query(res_state, const char *, ns_class, ns_type,
6cff8371 TL	77	double , ns_msg , int *);
3997081b TL	78
	79	/* Public. */
	80
	81	/*
	82	* int
	83	* res_findzonecut(res, dname, class, zname, zsize, addrs, naddrs)
	84	* find enclosing zone for a <dname,class>, and some server addresses
	85	* parameters:
	86	* res - resolver context to work within (is modified)
	87	* dname - domain name whose enclosing zone is desired
	88	* class - class of dname (and its enclosing zone)
	89	* zname - found zone name
	90	* zsize - allocated size of zname
	91	* addrs - found server addresses
	92	* naddrs - max number of addrs
	93	* return values:
	94	* < 0 - an error occurred (check errno)
	95	* = 0 - zname is now valid, but addrs[] wasn't changed
	96	* > 0 - zname is now valid, and return value is number of addrs[] found
	97	* notes:
	98	* this function calls res_nsend() which means it depends on correctly
	99	* functioning recursive nameservers (usually defined in /etc/resolv.conf
	100	* or its local equivilent).
	101	*
	102	* we start by asking for an SOA<dname,class>. if we get one as an
	103	* answer, that just means <dname,class> is a zone top, which is fine.
	104	* more than likely we'll be told to go pound sand, in the form of a
	105	* negative answer.
	106	*
	107	* note that we are not prepared to deal with referrals since that would
	108	* only come from authority servers and our correctly functioning local
	109	* recursive server would have followed the referral and got us something
	110	* more definite.
	111	*
	112	* if the authority section contains an SOA, this SOA should also be the
	113	* closest enclosing zone, since any intermediary zone cuts would've been
	114	* returned as referrals and dealt with by our correctly functioning local
	115	* recursive name server. but an SOA in the authority section should NOT
	116	* match our dname (since that would have been returned in the answer
	117	* section). an authority section SOA has to be "above" our dname.
	118	*
	119	* we cannot fail to find an SOA in this way. ultimately we'll return
	120	* a zname indicating the root zone if that's the closest enclosing zone.
	121	* however, since authority section SOA's were once optional, it's
	122	* possible that we'll have to go hunting for the enclosing SOA by
	123	* ripping labels off the front of our dname -- this is known as "doing
	124	* it the hard way."
	125	*
	126	* ultimately we want some server addresses, which are ideally the ones
	127	* pertaining to the SOA.MNAME, but only if there is a matching NS RR.
	128	* so the second phase (after we find an SOA) is to go looking for the
	129	* NS RRset for that SOA's zone.
	130	*
	131	* no answer section processed by this code is allowed to contain CNAME
	132	* or DNAME RR's. for the SOA query this means we strip a label and
	133	* keep going. for the NS and A queries this means we just give up.
	134	*/
	135
6cff8371	136	isc_result_t
3997081b	137	res_findzonecut(res_state statp, const char *dname, ns_class class, int opts,
2e987b1e	138	char zname, size_t zsize, struct in_addr addrs, int naddrs,
10a19b8c	139	int count, void zcookie)
3997081b TL	140	{
	141	char mname[NS_MAXDNAME];
	142	u_long save_pfcode;
	143	rrset_ns nsrrs;
10a19b8c	144	int n = 0;
5abf0a44	145	isc_result_t rcode;
233b79e1	146
3997081b TL	147	DPRINTF(("START dname='%s' class=%s, zsize=%ld, naddrs=%d",
	148	dname, p_class(class), (long)zsize, naddrs));
	149	save_pfcode = statp->pfcode;
	150	statp->pfcode \|= RES_PRF_HEAD2 \| RES_PRF_HEAD1 \| RES_PRF_HEADX \|
	151	RES_PRF_QUES \| RES_PRF_ANS \|
	152	RES_PRF_AUTH \| RES_PRF_ADD;
	153	ISC_LIST_INIT(nsrrs);
	154
bd941782	155	DPRINTF (("look for a predefined zone statement"));
5abf0a44 TL	156	rcode = find_cached_zone (dname, class, zname, zsize,
	157	addrs, naddrs, &n, zcookie);
	158	if (rcode == ISC_R_SUCCESS)
bd941782 TL	159	goto done;
bd941782 TL	160
3997081b	161	DPRINTF(("get the soa, and see if it has enough glue"));
233b79e1	162	if ((rcode = get_soa(statp, dname, class, zname, zsize,
b7f80038	163	mname, sizeof mname, &nsrrs)) != ISC_R_SUCCESS \|\|
3997081b TL	164	((opts & RES_EXHAUSTIVE) == 0 &&
	165	(n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
	166	goto done;
	167
	168	DPRINTF(("get the ns rrset and see if it has enough glue"));
b7f80038	169	if ((rcode = get_ns(statp, zname, class, &nsrrs)) != ISC_R_SUCCESS \|\|
3997081b TL	170	((opts & RES_EXHAUSTIVE) == 0 &&
	171	(n = satisfy(statp, mname, &nsrrs, addrs, naddrs)) > 0))
	172	goto done;
	173
	174	DPRINTF(("get the missing glue and see if it's finally enough"));
b7f80038	175	if ((rcode = get_glue(statp, class, &nsrrs)) == ISC_R_SUCCESS)
3997081b TL	176	n = satisfy(statp, mname, &nsrrs, addrs, naddrs);
3997081b TL	177
e8bc9d31 TL	178	/* If we found the zone, cache it. */
	179	if (n > 0)
	180	cache_found_zone (class, zname, addrs, n);
3997081b TL	181	done:
	182	DPRINTF(("FINISH n=%d (%s)", n, (n < 0) ? strerror(errno) : "OK"));
	183	free_nsrrset(&nsrrs);
	184	statp->pfcode = save_pfcode;
10a19b8c TL	185	if (count)
10a19b8c TL	186	*count = n;
233b79e1	187	return rcode;
3997081b TL	188	}
	189
	190	/* Private. */
	191
	192	static int
	193	satisfy(res_state statp,
	194	const char mname, rrset_ns nsrrsp, struct in_addr *addrs, int naddrs)
	195	{
	196	rr_ns *nsrr;
	197	int n, x;
	198
	199	n = 0;
	200	nsrr = find_ns(nsrrsp, mname);
	201	if (nsrr != NULL) {
	202	x = add_addrs(statp, nsrr, addrs, naddrs);
	203	addrs += x;
	204	naddrs -= x;
	205	n += x;
	206	}
	207	for (nsrr = ISC_LIST_HEAD(*nsrrsp);
	208	nsrr != NULL && naddrs > 0;
	209	nsrr = ISC_LIST_NEXT(nsrr, link))
	210	if (ns_samename(nsrr->name, mname) != 1) {
	211	x = add_addrs(statp, nsrr, addrs, naddrs);
	212	addrs += x;
	213	naddrs -= x;
	214	n += x;
	215	}
	216	DPRINTF(("satisfy(%s): %d", mname, n));
	217	return (n);
	218	}
	219
	220	static int
	221	add_addrs(res_state statp, rr_ns nsrr, struct in_addr addrs, int naddrs) {
	222	rr_a *arr;
	223	int n = 0;
	224
	225	for (arr = ISC_LIST_HEAD(nsrr->addrs);
	226	arr != NULL; arr = ISC_LIST_NEXT(arr, link)) {
	227	if (naddrs <= 0)
	228	return (0);
	229	*addrs++ = arr->addr;
	230	naddrs--;
	231	n++;
	232	}
	233	DPRINTF(("add_addrs: %d", n));
	234	return (n);
	235	}
	236
233b79e1	237	static ns_rcode
3997081b TL	238	get_soa(res_state statp, const char *dname, ns_class class,
	239	char zname, size_t zsize, char mname, size_t msize,
	240	rrset_ns *nsrrsp)
	241	{
	242	char tname[NS_MAXDNAME];
47082c65	243	double resp[NS_PACKETSZ / sizeof (double)];
3997081b TL	244	int n, i, ancount, nscount;
	245	ns_sect sect;
	246	ns_msg msg;
	247	u_int rcode;
5abf0a44	248	isc_result_t status;
3997081b TL	249
	250	/*
	251	* Find closest enclosing SOA, even if it's for the root zone.
	252	*/
	253
	254	/* First canonicalize dname (exactly one unescaped trailing "."). */
5abf0a44 TL	255	status = ns_makecanon(dname, tname, sizeof tname);
	256	if (status != ISC_R_SUCCESS)
	257	return status;
3997081b TL	258	dname = tname;
	259
	260	/* Now grovel the subdomains, hunting for an SOA answer or auth. */
	261	for (;;) {
	262	/* Leading or inter-label '.' are skipped here. */
	263	while (*dname == '.')
	264	dname++;
	265
	266	/* Is there an SOA? */
233b79e1 TL	267	rcode = do_query(statp, dname, class, ns_t_soa,
233b79e1 TL	268	resp, &msg, &n);
14e8ade5	269	if (rcode != ISC_R_SUCCESS) {
3997081b TL	270	DPRINTF(("get_soa: do_query('%s', %s) failed (%d)",
3997081b TL	271	dname, p_class(class), n));
233b79e1	272	return rcode;
3997081b TL	273	}
	274	if (n > 0) {
	275	DPRINTF(("get_soa: CNAME or DNAME found"));
	276	sect = ns_s_max, n = 0;
	277	} else {
3997081b TL	278	ancount = ns_msg_count(msg, ns_s_an);
3997081b TL	279	nscount = ns_msg_count(msg, ns_s_ns);
b7f80038	280	if (ancount > 0 && rcode == ISC_R_SUCCESS)
3997081b TL	281	sect = ns_s_an, n = ancount;
	282	else if (nscount > 0)
	283	sect = ns_s_ns, n = nscount;
	284	else
	285	sect = ns_s_max, n = 0;
	286	}
	287	for (i = 0; i < n; i++) {
	288	const char *t;
	289	const u_char *rdata;
	290	int rdlen;
	291	ns_rr rr;
	292
5abf0a44 TL	293	rcode = ns_parserr(&msg, sect, i, &rr) < 0;
5abf0a44 TL	294	if (rcode != ISC_R_SUCCESS) {
3997081b TL	295	DPRINTF(("get_soa: ns_parserr(%s, %d) failed",
3997081b TL	296	p_section(sect, ns_o_query), i));
5abf0a44	297	return rcode;
3997081b TL	298	}
	299	if (ns_rr_type(rr) == ns_t_cname \|\|
	300	ns_rr_type(rr) == ns_t_dname)
	301	break;
	302	if (ns_rr_type(rr) != ns_t_soa \|\|
	303	ns_rr_class(rr) != class)
	304	continue;
	305	t = ns_rr_name(rr);
	306	switch (sect) {
	307	case ns_s_an:
	308	if (ns_samedomain(dname, t) == 0) {
5abf0a44 TL	309	DPRINTF(("get_soa: %s'%s', '%s') == 0",
	310	"ns_samedomain(", dname, t));
	311	return ISC_R_NOTZONE;
3997081b TL	312	}
	313	break;
	314	case ns_s_ns:
	315	if (ns_samename(dname, t) == 1 \|\|
	316	ns_samedomain(dname, t) == 0) {
5abf0a44 TL	317	DPRINTF(("get_soa: %smain('%s', '%s')",
5abf0a44 TL	318	"ns_samename() \|\| !ns_samedo",
3997081b	319	dname, t));
5abf0a44	320	return ISC_R_NOTZONE;
3997081b TL	321	}
	322	break;
	323	default:
	324	abort();
	325	}
	326	if (strlen(t) + 1 > zsize) {
	327	DPRINTF(("get_soa: zname(%d) too small (%d)",
	328	zsize, strlen(t) + 1));
5abf0a44	329	return ISC_R_NOSPACE;
3997081b TL	330	}
	331	strcpy(zname, t);
	332	rdata = ns_rr_rdata(rr);
	333	rdlen = ns_rr_rdlen(rr);
47082c65 TL	334	if (ns_name_uncompress((u_char *)resp,
47082c65 TL	335	ns_msg_end(msg), rdata,
3997081b	336	mname, msize) < 0) {
5abf0a44 TL	337	DPRINTF(("get_soa: %s failed",
	338	"ns_name_uncompress"));
	339	return ISC_R_NOMEMORY;
3997081b	340	}
5abf0a44 TL	341	rcode = save_ns(statp, &msg,
	342	ns_s_ns, zname, class, nsrrsp);
	343	if (rcode != ISC_R_SUCCESS) {
3997081b	344	DPRINTF(("get_soa: save_ns failed"));
5abf0a44	345	return rcode;
3997081b	346	}
5abf0a44	347	return ISC_R_SUCCESS;
3997081b TL	348	}
	349
	350	/* If we're out of labels, then not even "." has an SOA! */
	351	if (*dname == '\0')
	352	break;
	353
	354	/* Find label-terminating "."; top of loop will skip it. */
	355	while (*dname != '.') {
	356	if (*dname == '\\')
	357	if (*++dname == '\0') {
5abf0a44	358	ISC_R_NOSPACE;
3997081b TL	359	}
	360	dname++;
	361	}
	362	}
	363	DPRINTF(("get_soa: out of labels"));
5abf0a44	364	return ISC_R_DESTADDRREQ;
3997081b TL	365	}
3997081b TL	366
5abf0a44	367	static isc_result_t
3997081b	368	get_ns(res_state statp, const char zname, ns_class class, rrset_ns nsrrsp) {
47082c65	369	double resp[NS_PACKETSZ / sizeof (double)];
3997081b TL	370	ns_msg msg;
3997081b TL	371	int n;
5abf0a44	372	isc_result_t rcode;
3997081b TL	373
3997081b TL	374	/* Go and get the NS RRs for this zone. */
233b79e1	375	rcode = do_query(statp, zname, class, ns_t_ns, resp, &msg, &n);
5abf0a44	376	if (rcode != ISC_R_SUCCESS) {
3997081b	377	DPRINTF(("get_ns: do_query('zname', %s) failed (%d)",
233b79e1 TL	378	zname, p_class(class), rcode));
233b79e1 TL	379	return rcode;
3997081b TL	380	}
	381
	382	/* Remember the NS RRs and associated A RRs that came back. */
5abf0a44 TL	383	rcode = save_ns(statp, &msg, ns_s_an, zname, class, nsrrsp);
5abf0a44 TL	384	if (rcode != ISC_R_SUCCESS) {
3997081b TL	385	DPRINTF(("get_ns save_ns('%s', %s) failed",
3997081b TL	386	zname, p_class(class)));
5abf0a44	387	return rcode;
3997081b TL	388	}
3997081b TL	389
5abf0a44	390	return ISC_R_SUCCESS;
3997081b TL	391	}
3997081b TL	392
5abf0a44	393	static isc_result_t
3997081b TL	394	get_glue(res_state statp, ns_class class, rrset_ns *nsrrsp) {
	395	rr_ns nsrr, nsrr_n;
	396
	397	/* Go and get the A RRs for each empty NS RR on our list. */
	398	for (nsrr = ISC_LIST_HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
47082c65	399	double resp[NS_PACKETSZ / sizeof (double)];
3997081b TL	400	ns_msg msg;
3997081b TL	401	int n;
5abf0a44	402	isc_result_t rcode;
3997081b TL	403
	404	nsrr_n = ISC_LIST_NEXT(nsrr, link);
	405
	406	if (ISC_LIST_EMPTY(nsrr->addrs)) {
233b79e1 TL	407	rcode = do_query(statp, nsrr->name, class, ns_t_a,
233b79e1 TL	408	resp, &msg, &n);
5abf0a44 TL	409	if (rcode != ISC_R_SUCCESS) {
	410	DPRINTF(("get_glue: do_query('%s', %s') failed",
	411	nsrr->name, p_class(class)));
	412	return rcode;
3997081b TL	413	}
	414	if (n > 0) {
	415	DPRINTF((
	416	"get_glue: do_query('%s', %s') CNAME or DNAME found",
	417	nsrr->name, p_class(class)));
	418	}
5abf0a44 TL	419	rcode = save_a(statp, &msg, ns_s_an, nsrr->name, class,
	420	&nsrr->addrs);
	421	if (rcode != ISC_R_SUCCESS) {
3997081b TL	422	DPRINTF(("get_glue: save_r('%s', %s) failed",
3997081b TL	423	nsrr->name, p_class(class)));
5abf0a44	424	return rcode;
3997081b TL	425	}
	426	/* If it's still empty, it's just chaff. */
	427	if (ISC_LIST_EMPTY(nsrr->addrs)) {
	428	DPRINTF(("get_glue: removing empty '%s' NS",
	429	nsrr->name));
	430	free_nsrr(nsrrsp, nsrr);
	431	}
	432	}
	433	}
5abf0a44	434	return ISC_R_SUCCESS;
3997081b TL	435	}
3997081b TL	436
5abf0a44	437	static isc_result_t
3997081b TL	438	save_ns(res_state statp, ns_msg *msg, ns_sect sect,
	439	const char *owner, ns_class class,
	440	rrset_ns *nsrrsp)
	441	{
	442	int i;
5abf0a44	443	isc_result_t rcode;
3997081b TL	444
	445	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
	446	char tname[MAXDNAME];
	447	const u_char *rdata;
	448	rr_ns *nsrr;
	449	ns_rr rr;
	450	int rdlen;
	451
5abf0a44 TL	452	rcode = ns_parserr(msg, sect, i, &rr);
5abf0a44 TL	453	if (rcode != ISC_R_SUCCESS) {
3997081b TL	454	DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
3997081b TL	455	p_section(sect, ns_o_query), i));
5abf0a44	456	return rcode;
3997081b TL	457	}
	458	if (ns_rr_type(rr) != ns_t_ns \|\|
	459	ns_rr_class(rr) != class \|\|
	460	ns_samename(ns_rr_name(rr), owner) != 1)
	461	continue;
	462	nsrr = find_ns(nsrrsp, ns_rr_name(rr));
	463	if (nsrr == NULL) {
	464	nsrr = malloc(sizeof *nsrr);
	465	if (nsrr == NULL) {
	466	DPRINTF(("save_ns: malloc failed"));
5abf0a44	467	return ISC_R_NOMEMORY;
3997081b TL	468	}
	469	rdata = ns_rr_rdata(rr);
	470	rdlen = ns_rr_rdlen(rr);
	471	if (ns_name_uncompress(ns_msg_base(*msg),
	472	ns_msg_end(*msg), rdata,
	473	tname, sizeof tname) < 0) {
	474	DPRINTF(("save_ns: ns_name_uncompress failed"));
	475	free(nsrr);
5abf0a44	476	return ISC_R_NOMEMORY;
3997081b TL	477	}
	478	nsrr->name = strdup(tname);
	479	if (nsrr->name == NULL) {
	480	DPRINTF(("save_ns: strdup failed"));
	481	free(nsrr);
5abf0a44	482	return ISC_R_NOMEMORY;
3997081b TL	483	}
	484	ISC_LIST_INIT(nsrr->addrs);
	485	ISC_LIST_APPEND(*nsrrsp, nsrr, link);
	486	}
5abf0a44 TL	487	rcode = save_a(statp, msg, ns_s_ar,
	488	nsrr->name, class, &nsrr->addrs);
	489	if (rcode != ISC_R_SUCCESS) {
3997081b TL	490	DPRINTF(("save_ns: save_r('%s', %s) failed",
3997081b TL	491	nsrr->name, p_class(class)));
5abf0a44	492	return rcode;
3997081b TL	493	}
3997081b TL	494	}
5abf0a44	495	return ISC_R_SUCCESS;
3997081b TL	496	}
3997081b TL	497
5abf0a44	498	static isc_result_t
3997081b TL	499	save_a(res_state statp, ns_msg *msg, ns_sect sect,
	500	const char *owner, ns_class class,
	501	rrset_a *arrsp)
	502	{
	503	int i;
5abf0a44	504	isc_result_t rcode;
3997081b TL	505
	506	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
	507	ns_rr rr;
	508	rr_a *arr;
	509
5abf0a44 TL	510	rcode = ns_parserr(msg, sect, i, &rr);
5abf0a44 TL	511	if (rcode != ISC_R_SUCCESS) {
3997081b TL	512	DPRINTF(("save_a: ns_parserr(%s, %d) failed",
3997081b TL	513	p_section(sect, ns_o_query), i));
5abf0a44	514	return rcode;
3997081b TL	515	}
	516	if (ns_rr_type(rr) != ns_t_a \|\|
	517	ns_rr_class(rr) != class \|\|
	518	ns_samename(ns_rr_name(rr), owner) != 1 \|\|
	519	ns_rr_rdlen(rr) != NS_INADDRSZ)
	520	continue;
	521	arr = malloc(sizeof *arr);
	522	if (arr == NULL) {
	523	DPRINTF(("save_a: malloc failed"));
5abf0a44	524	return ISC_R_NOMEMORY;
3997081b TL	525	}
	526	memcpy(&arr->addr, ns_rr_rdata(rr), NS_INADDRSZ);
	527	ISC_LIST_APPEND(*arrsp, arr, link);
	528	}
5abf0a44	529	return ISC_R_SUCCESS;
3997081b TL	530	}
	531
	532	static void
	533	free_nsrrset(rrset_ns *nsrrsp) {
	534	rr_ns *nsrr;
	535
	536	while ((nsrr = ISC_LIST_HEAD(*nsrrsp)) != NULL)
	537	free_nsrr(nsrrsp, nsrr);
	538	}
	539
	540	static void
	541	free_nsrr(rrset_ns nsrrsp, rr_ns nsrr) {
	542	rr_a *arr;
	543
	544	while ((arr = ISC_LIST_HEAD(nsrr->addrs)) != NULL) {
	545	ISC_LIST_UNLINK(nsrr->addrs, arr, link);
	546	free(arr);
	547	}
	548	free((char *)nsrr->name);
	549	ISC_LIST_UNLINK(*nsrrsp, nsrr, link);
	550	free(nsrr);
	551	}
	552
	553	static rr_ns *
	554	find_ns(rrset_ns nsrrsp, const char dname) {
	555	rr_ns *nsrr;
	556
	557	for (nsrr = ISC_LIST_HEAD(*nsrrsp);
	558	nsrr != NULL; nsrr = ISC_LIST_NEXT(nsrr, link))
	559	if (ns_samename(nsrr->name, dname) == 1)
	560	return (nsrr);
	561	return (NULL);
	562	}
	563
5abf0a44	564	static isc_result_t
3997081b	565	do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
47082c65	566	double resp, ns_msg msg, int *alias_count)
3997081b	567	{
47082c65	568	double req[NS_PACKETSZ / sizeof (double)];
3997081b TL	569	int i;
3997081b TL	570	unsigned n;
5abf0a44	571	isc_result_t status;
3997081b	572
5abf0a44 TL	573	status = res_nmkquery(statp, ns_o_query, dname, class, qtype,
	574	NULL, 0, NULL, req, NS_PACKETSZ, &n);
	575	if (status != ISC_R_SUCCESS) {
3997081b	576	DPRINTF(("do_query: res_nmkquery failed"));
5abf0a44	577	return status;
3997081b	578	}
5abf0a44 TL	579	status = res_nsend(statp, req, n, resp, NS_PACKETSZ, &n);
5abf0a44 TL	580	if (status != ISC_R_SUCCESS) {
3997081b	581	DPRINTF(("do_query: res_nsend failed"));
5abf0a44	582	return status;
3997081b TL	583	}
	584	if (n == 0) {
	585	DPRINTF(("do_query: res_nsend returned 0"));
5abf0a44	586	return ISC_R_NOTFOUND;
3997081b	587	}
47082c65	588	if (ns_initparse((u_char *)resp, n, msg) < 0) {
3997081b	589	DPRINTF(("do_query: ns_initparse failed"));
5abf0a44	590	return ISC_R_NOSPACE;
3997081b TL	591	}
	592	n = 0;
	593	for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
	594	ns_rr rr;
	595
5abf0a44 TL	596	status = ns_parserr(msg, ns_s_an, i, &rr);
5abf0a44 TL	597	if (status != ISC_R_SUCCESS) {
3997081b	598	DPRINTF(("do_query: ns_parserr failed"));
5abf0a44	599	return status;
3997081b TL	600	}
	601	n += (ns_rr_class(rr) == class &&
	602	(ns_rr_type(rr) == ns_t_cname \|\|
	603	ns_rr_type(rr) == ns_t_dname));
	604	}
233b79e1 TL	605	if (alias_count)
233b79e1 TL	606	*alias_count = n;
b7f80038	607	return ISC_R_SUCCESS;
3997081b	608	}