[gssapi-openssh.git] / openssh / openbsd-compat / getrrsetbyname.c

/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */

/* $OpenBSD: getrrsetbyname.c,v 1.7 2003/03/07 07:34:14 itojun Exp $ */

/*
 * Copyright (c) 2001 Jakob Schlyter. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Portions Copyright (c) 1999-2001 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.
 */

#include "includes.h"

#ifndef HAVE_GETRRSETBYNAME

#include "getrrsetbyname.h"

#define ANSWER_BUFFER_SIZE 1024*64

#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
extern int h_errno;
#endif

struct dns_query {
	char			*name;
	u_int16_t		type;
	u_int16_t		class;
	struct dns_query	*next;
};

struct dns_rr {
	char			*name;
	u_int16_t		type;
	u_int16_t		class;
	u_int16_t		ttl;
	u_int16_t		size;
	void			*rdata;
	struct dns_rr		*next;
};

struct dns_response {
	HEADER			header;
	struct dns_query	*query;
	struct dns_rr		*answer;
	struct dns_rr		*authority;
	struct dns_rr		*additional;
};

static struct dns_response *parse_dns_response(const u_char *, int);
static struct dns_query *parse_dns_qsection(const u_char *, int,
    const u_char **, int);
static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
    int);

static void free_dns_query(struct dns_query *);
static void free_dns_rr(struct dns_rr *);
static void free_dns_response(struct dns_response *);

static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);

/*
 * Inline versions of get/put short/long.  Pointer is advanced.
 *
 * These macros demonstrate the property of C whereby it can be
 * portable or it can be elegant but rarely both.
 */

#ifndef INT32SZ
# define INT32SZ	4
#endif
#ifndef INT16SZ
# define INT16SZ	2
#endif

#ifndef GETSHORT
#define GETSHORT(s, cp) { \
	register u_char *t_cp = (u_char *)(cp); \
	(s) = ((u_int16_t)t_cp[0] << 8) \
	    | ((u_int16_t)t_cp[1]) \
	    ; \
	(cp) += INT16SZ; \
}
#endif

#ifndef GETLONG
#define GETLONG(l, cp) { \
	register u_char *t_cp = (u_char *)(cp); \
	(l) = ((u_int32_t)t_cp[0] << 24) \
	    | ((u_int32_t)t_cp[1] << 16) \
	    | ((u_int32_t)t_cp[2] << 8) \
	    | ((u_int32_t)t_cp[3]) \
	    ; \
	(cp) += INT32SZ; \
}
#endif

/*
 * Routines to insert/extract short/long's.
 */

#ifndef HAVE__GETSHORT
static u_int16_t
_getshort(msgp)
	register const u_char *msgp;
{
	register u_int16_t u;

	GETSHORT(u, msgp);
	return (u);
}
#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
u_int16_t _getshort(register const u_char *);
#endif

#ifndef HAVE__GETLONG
static u_int32_t
_getlong(msgp)
	register const u_char *msgp;
{
	register u_int32_t u;

	GETLONG(u, msgp);
	return (u);
}
#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
u_int32_t _getlong(register const u_char *);
#endif

int
getrrsetbyname(const char *hostname, unsigned int rdclass,
    unsigned int rdtype, unsigned int flags,
    struct rrsetinfo **res)
{
	int result;
	struct rrsetinfo *rrset = NULL;
	struct dns_response *response;
	struct dns_rr *rr;
	struct rdatainfo *rdata;
	int length;
	unsigned int index_ans, index_sig;
	u_char answer[ANSWER_BUFFER_SIZE];

	/* check for invalid class and type */
	if (rdclass > 0xffff || rdtype > 0xffff) {
		result = ERRSET_INVAL;
		goto fail;
	}

	/* don't allow queries of class or type ANY */
	if (rdclass == 0xff || rdtype == 0xff) {
		result = ERRSET_INVAL;
		goto fail;
	}

	/* don't allow flags yet, unimplemented */
	if (flags) {
		result = ERRSET_INVAL;
		goto fail;
	}

	/* initialize resolver */
	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
		result = ERRSET_FAIL;
		goto fail;
	}

#ifdef DEBUG
	_res.options |= RES_DEBUG;
#endif /* DEBUG */

#ifdef RES_USE_DNSSEC
	/* turn on DNSSEC if EDNS0 is configured */
	if (_res.options & RES_USE_EDNS0)
		_res.options |= RES_USE_DNSSEC;
#endif /* RES_USE_DNSEC */

	/* make query */
	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
	    answer, sizeof(answer));
	if (length < 0) {
		switch(h_errno) {
		case HOST_NOT_FOUND:
			result = ERRSET_NONAME;
			goto fail;
		case NO_DATA:
			result = ERRSET_NODATA;
			goto fail;
		default:
			result = ERRSET_FAIL;
			goto fail;
		}
	}

	/* parse result */
	response = parse_dns_response(answer, length);
	if (response == NULL) {
		result = ERRSET_FAIL;
		goto fail;
	}

	if (response->header.qdcount != 1) {
		result = ERRSET_FAIL;
		goto fail;
	}

	/* initialize rrset */
	rrset = calloc(1, sizeof(struct rrsetinfo));
	if (rrset == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}
	rrset->rri_rdclass = response->query->class;
	rrset->rri_rdtype = response->query->type;
	rrset->rri_ttl = response->answer->ttl;
	rrset->rri_nrdatas = response->header.ancount;

#ifdef HAVE_HEADER_AD
	/* check for authenticated data */
	if (response->header.ad == 1)
		rrset->rri_flags |= RRSET_VALIDATED;
#endif

	/* copy name from answer section */
	length = strlen(response->answer->name);
	rrset->rri_name = malloc(length + 1);
	if (rrset->rri_name == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}
	strlcpy(rrset->rri_name, response->answer->name, length + 1);

	/* count answers */
	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	    rrset->rri_rdtype);
	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	    T_SIG);

	/* allocate memory for answers */
	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	    sizeof(struct rdatainfo));
	if (rrset->rri_rdatas == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}

	/* allocate memory for signatures */
	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
	if (rrset->rri_nsigs > 0 && rrset->rri_sigs == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}

	/* copy answers & signatures */
	for (rr = response->answer, index_ans = 0, index_sig = 0;
	    rr; rr = rr->next) {

		rdata = NULL;

		if (rr->class == rrset->rri_rdclass &&
		    rr->type  == rrset->rri_rdtype)
			rdata = &rrset->rri_rdatas[index_ans++];

		if (rr->class == rrset->rri_rdclass &&
		    rr->type  == T_SIG)
			rdata = &rrset->rri_sigs[index_sig++];

		if (rdata) {
			rdata->rdi_length = rr->size;
			rdata->rdi_data   = malloc(rr->size);

			if (rdata->rdi_data == NULL) {
				result = ERRSET_NOMEMORY;
				goto fail;
			}
			memcpy(rdata->rdi_data, rr->rdata, rr->size);
		}
	}

	*res = rrset;
	return (ERRSET_SUCCESS);

fail:
	if (rrset != NULL)
		freerrset(rrset);
	return (result);
}

void
freerrset(struct rrsetinfo *rrset)
{
	u_int16_t i;

	if (rrset == NULL)
		return;

	if (rrset->rri_rdatas) {
		for (i = 0; i < rrset->rri_nrdatas; i++) {
			if (rrset->rri_rdatas[i].rdi_data == NULL)
				break;
			free(rrset->rri_rdatas[i].rdi_data);
		}
		free(rrset->rri_rdatas);
	}

	if (rrset->rri_sigs) {
		for (i = 0; i < rrset->rri_nsigs; i++) {
			if (rrset->rri_sigs[i].rdi_data == NULL)
				break;
			free(rrset->rri_sigs[i].rdi_data);
		}
		free(rrset->rri_sigs);
	}

	if (rrset->rri_name)
		free(rrset->rri_name);
	free(rrset);
}

/*
 * DNS response parsing routines
 */
static struct dns_response *
parse_dns_response(const u_char *answer, int size)
{
	struct dns_response *resp;
	const u_char *cp;

	/* allocate memory for the response */
	resp = calloc(1, sizeof(*resp));
	if (resp == NULL)
		return (NULL);

	/* initialize current pointer */
	cp = answer;

	/* copy header */
	memcpy(&resp->header, cp, HFIXEDSZ);
	cp += HFIXEDSZ;

	/* fix header byte order */
	resp->header.qdcount = ntohs(resp->header.qdcount);
	resp->header.ancount = ntohs(resp->header.ancount);
	resp->header.nscount = ntohs(resp->header.nscount);
	resp->header.arcount = ntohs(resp->header.arcount);

	/* there must be at least one query */
	if (resp->header.qdcount < 1) {
		free_dns_response(resp);
		return (NULL);
	}

	/* parse query section */
	resp->query = parse_dns_qsection(answer, size, &cp,
	    resp->header.qdcount);
	if (resp->header.qdcount && resp->query == NULL) {
		free_dns_response(resp);
		return (NULL);
	}

	/* parse answer section */
	resp->answer = parse_dns_rrsection(answer, size, &cp,
	    resp->header.ancount);
	if (resp->header.ancount && resp->answer == NULL) {
		free_dns_response(resp);
		return (NULL);
	}

	/* parse authority section */
	resp->authority = parse_dns_rrsection(answer, size, &cp,
	    resp->header.nscount);
	if (resp->header.nscount && resp->authority == NULL) {
		free_dns_response(resp);
		return (NULL);
	}

	/* parse additional section */
	resp->additional = parse_dns_rrsection(answer, size, &cp,
	    resp->header.arcount);
	if (resp->header.arcount && resp->additional == NULL) {
		free_dns_response(resp);
		return (NULL);
	}

	return (resp);
}

static struct dns_query *
parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
{
	struct dns_query *head, *curr, *prev;
	int i, length;
	char name[MAXDNAME];

	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {

		/* allocate and initialize struct */
		curr = calloc(1, sizeof(struct dns_query));
		if (curr == NULL) {
			free_dns_query(head);
			return (NULL);
		}
		if (head == NULL)
			head = curr;
		if (prev != NULL)
			prev->next = curr;

		/* name */
		length = dn_expand(answer, answer + size, *cp, name,
		    sizeof(name));
		if (length < 0) {
			free_dns_query(head);
			return (NULL);
		}
		curr->name = strdup(name);
		if (curr->name == NULL) {
			free_dns_query(head);
			return (NULL);
		}
		*cp += length;

		/* type */
		curr->type = _getshort(*cp);
		*cp += INT16SZ;

		/* class */
		curr->class = _getshort(*cp);
		*cp += INT16SZ;
	}

	return (head);
}

static struct dns_rr *
parse_dns_rrsection(const u_char *answer, int size, const u_char **cp, int count)
{
	struct dns_rr *head, *curr, *prev;
	int i, length;
	char name[MAXDNAME];

	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {

		/* allocate and initialize struct */
		curr = calloc(1, sizeof(struct dns_rr));
		if (curr == NULL) {
			free_dns_rr(head);
			return (NULL);
		}
		if (head == NULL)
			head = curr;
		if (prev != NULL)
			prev->next = curr;

		/* name */
		length = dn_expand(answer, answer + size, *cp, name,
		    sizeof(name));
		if (length < 0) {
			free_dns_rr(head);
			return (NULL);
		}
		curr->name = strdup(name);
		if (curr->name == NULL) {
			free_dns_rr(head);
			return (NULL);
		}
		*cp += length;

		/* type */
		curr->type = _getshort(*cp);
		*cp += INT16SZ;

		/* class */
		curr->class = _getshort(*cp);
		*cp += INT16SZ;

		/* ttl */
		curr->ttl = _getlong(*cp);
		*cp += INT32SZ;

		/* rdata size */
		curr->size = _getshort(*cp);
		*cp += INT16SZ;

		/* rdata itself */
		curr->rdata = malloc(curr->size);
		if (curr->rdata == NULL) {
			free_dns_rr(head);
			return (NULL);
		}
		memcpy(curr->rdata, *cp, curr->size);
		*cp += curr->size;
	}

	return (head);
}

static void
free_dns_query(struct dns_query *p)
{
	if (p == NULL)
		return;

	if (p->name)
		free(p->name);
	free_dns_query(p->next);
	free(p);
}

static void
free_dns_rr(struct dns_rr *p)
{
	if (p == NULL)
		return;

	if (p->name)
		free(p->name);
	if (p->rdata)
		free(p->rdata);
	free_dns_rr(p->next);
	free(p);
}

static void
free_dns_response(struct dns_response *p)
{
	if (p == NULL)
		return;

	free_dns_query(p->query);
	free_dns_rr(p->answer);
	free_dns_rr(p->authority);
	free_dns_rr(p->additional);
	free(p);
}

static int
count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
{
	int n = 0;

	while(p) {
		if (p->class == class && p->type == type)
			n++;
		p = p->next;
	}

	return (n);
}

#endif /* !defined(HAVE_GETRRSETBYNAME) */
Commit	Line	Data
cdd66111	1	/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
cdd66111	2
0fff78ff	3	/* $OpenBSD: getrrsetbyname.c,v 1.7 2003/03/07 07:34:14 itojun Exp $ */
	4
	5	/*
	6	* Copyright (c) 2001 Jakob Schlyter. All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* 1. Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	*
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	*
	19	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	20	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	21	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	22	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	23	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	24	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	25	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	26	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	27	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	28	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	29	*/
	30
	31	/*
	32	* Portions Copyright (c) 1999-2001 Internet Software Consortium.
	33	*
	34	* Permission to use, copy, modify, and distribute this software for any
	35	* purpose with or without fee is hereby granted, provided that the above
	36	* copyright notice and this permission notice appear in all copies.
	37	*
	38	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
	39	* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
	40	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
	41	* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
	42	* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
	43	* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
	44	* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
	45	* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	46	*/
	47
	48	#include "includes.h"
	49
cdd66111	50	#ifndef HAVE_GETRRSETBYNAME
0fff78ff	51
	52	#include "getrrsetbyname.h"
	53
0fff78ff	54	#define ANSWER_BUFFER_SIZE 1024*64
0fff78ff	55
c9f39d2c	56	#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
	57	extern int h_errno;
	58	#endif
	59
0fff78ff	60	struct dns_query {
	61	char *name;
	62	u_int16_t type;
	63	u_int16_t class;
	64	struct dns_query *next;
	65	};
	66
	67	struct dns_rr {
	68	char *name;
	69	u_int16_t type;
	70	u_int16_t class;
	71	u_int16_t ttl;
	72	u_int16_t size;
	73	void *rdata;
	74	struct dns_rr *next;
	75	};
	76
	77	struct dns_response {
	78	HEADER header;
	79	struct dns_query *query;
	80	struct dns_rr *answer;
	81	struct dns_rr *authority;
	82	struct dns_rr *additional;
	83	};
	84
	85	static struct dns_response parse_dns_response(const u_char , int);
	86	static struct dns_query parse_dns_qsection(const u_char , int,
	87	const u_char **, int);
	88	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
	89	int);
	90
	91	static void free_dns_query(struct dns_query *);
	92	static void free_dns_rr(struct dns_rr *);
	93	static void free_dns_response(struct dns_response *);
	94
	95	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	96
	97	/*
	98	* Inline versions of get/put short/long. Pointer is advanced.
	99	*
	100	* These macros demonstrate the property of C whereby it can be
	101	* portable or it can be elegant but rarely both.
	102	*/
	103
	104	#ifndef INT32SZ
	105	# define INT32SZ 4
	106	#endif
	107	#ifndef INT16SZ
	108	# define INT16SZ 2
	109	#endif
	110
	111	#ifndef GETSHORT
	112	#define GETSHORT(s, cp) { \
	113	register u_char t_cp = (u_char )(cp); \
	114	(s) = ((u_int16_t)t_cp[0] << 8) \
	115	\| ((u_int16_t)t_cp[1]) \
	116	; \
	117	(cp) += INT16SZ; \
	118	}
	119	#endif
	120
	121	#ifndef GETLONG
	122	#define GETLONG(l, cp) { \
	123	register u_char t_cp = (u_char )(cp); \
124	(l) = ((u_int32_t)t_cp[0] << 24) \
125	\| ((u_int32_t)t_cp[1] << 16) \
126	\| ((u_int32_t)t_cp[2] << 8) \
127	\| ((u_int32_t)t_cp[3]) \
128	; \
129	(cp) += INT32SZ; \
130	}
131	#endif
132
133	/*
134	* Routines to insert/extract short/long's.
135	*/
136
137	#ifndef HAVE__GETSHORT
138	static u_int16_t
139	_getshort(msgp)
140	register const u_char *msgp;
141	{
142	register u_int16_t u;
143
144	GETSHORT(u, msgp);
145	return (u);
146	}
665a873d	147	#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
665a873d	148	u_int16_t _getshort(register const u_char *);
0fff78ff	149	#endif
	150
	151	#ifndef HAVE__GETLONG
	152	static u_int32_t
	153	_getlong(msgp)
	154	register const u_char *msgp;
	155	{
	156	register u_int32_t u;
	157
	158	GETLONG(u, msgp);
	159	return (u);
	160	}
665a873d	161	#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
665a873d	162	u_int32_t _getlong(register const u_char *);
0fff78ff	163	#endif
	164
	165	int
	166	getrrsetbyname(const char *hostname, unsigned int rdclass,
	167	unsigned int rdtype, unsigned int flags,
	168	struct rrsetinfo **res)
	169	{
0fff78ff	170	int result;
	171	struct rrsetinfo *rrset = NULL;
	172	struct dns_response *response;
	173	struct dns_rr *rr;
	174	struct rdatainfo *rdata;
	175	int length;
	176	unsigned int index_ans, index_sig;
	177	u_char answer[ANSWER_BUFFER_SIZE];
	178
	179	/* check for invalid class and type */
	180	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	181	result = ERRSET_INVAL;
	182	goto fail;
	183	}
	184
	185	/* don't allow queries of class or type ANY */
	186	if (rdclass == 0xff \|\| rdtype == 0xff) {
	187	result = ERRSET_INVAL;
	188	goto fail;
	189	}
	190
	191	/* don't allow flags yet, unimplemented */
	192	if (flags) {
	193	result = ERRSET_INVAL;
	194	goto fail;
	195	}
	196
	197	/* initialize resolver */
cdd66111	198	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
0fff78ff	199	result = ERRSET_FAIL;
	200	goto fail;
	201	}
	202
	203	#ifdef DEBUG
cdd66111	204	_res.options \|= RES_DEBUG;
0fff78ff	205	#endif /* DEBUG */
	206
	207	#ifdef RES_USE_DNSSEC
	208	/* turn on DNSSEC if EDNS0 is configured */
cdd66111	209	if (_res.options & RES_USE_EDNS0)
cdd66111	210	_res.options \|= RES_USE_DNSSEC;
0fff78ff	211	#endif /* RES_USE_DNSEC */
	212
	213	/* make query */
	214	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
	215	answer, sizeof(answer));
	216	if (length < 0) {
	217	switch(h_errno) {
	218	case HOST_NOT_FOUND:
	219	result = ERRSET_NONAME;
	220	goto fail;
	221	case NO_DATA:
	222	result = ERRSET_NODATA;
	223	goto fail;
	224	default:
	225	result = ERRSET_FAIL;
	226	goto fail;
	227	}
	228	}
	229
	230	/* parse result */
	231	response = parse_dns_response(answer, length);
	232	if (response == NULL) {
	233	result = ERRSET_FAIL;
	234	goto fail;
	235	}
	236
	237	if (response->header.qdcount != 1) {
	238	result = ERRSET_FAIL;
	239	goto fail;
	240	}
	241
	242	/* initialize rrset */
	243	rrset = calloc(1, sizeof(struct rrsetinfo));
	244	if (rrset == NULL) {
	245	result = ERRSET_NOMEMORY;
	246	goto fail;
	247	}
	248	rrset->rri_rdclass = response->query->class;
	249	rrset->rri_rdtype = response->query->type;
	250	rrset->rri_ttl = response->answer->ttl;
	251	rrset->rri_nrdatas = response->header.ancount;
	252
	253	#ifdef HAVE_HEADER_AD
	254	/* check for authenticated data */
	255	if (response->header.ad == 1)
	256	rrset->rri_flags \|= RRSET_VALIDATED;
	257	#endif
	258
	259	/* copy name from answer section */
	260	length = strlen(response->answer->name);
	261	rrset->rri_name = malloc(length + 1);
	262	if (rrset->rri_name == NULL) {
	263	result = ERRSET_NOMEMORY;
	264	goto fail;
	265	}
	266	strlcpy(rrset->rri_name, response->answer->name, length + 1);
	267
	268	/* count answers */
	269	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	270	rrset->rri_rdtype);
	271	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	272	T_SIG);
	273
	274	/* allocate memory for answers */
275	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
276	sizeof(struct rdatainfo));
277	if (rrset->rri_rdatas == NULL) {
278	result = ERRSET_NOMEMORY;
279	goto fail;
280	}
281
282	/* allocate memory for signatures */
283	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
996d5e62	284	if (rrset->rri_nsigs > 0 && rrset->rri_sigs == NULL) {
0fff78ff	285	result = ERRSET_NOMEMORY;
	286	goto fail;
	287	}
	288
	289	/* copy answers & signatures */
	290	for (rr = response->answer, index_ans = 0, index_sig = 0;
	291	rr; rr = rr->next) {
	292
	293	rdata = NULL;
	294
	295	if (rr->class == rrset->rri_rdclass &&
	296	rr->type == rrset->rri_rdtype)
	297	rdata = &rrset->rri_rdatas[index_ans++];
	298
	299	if (rr->class == rrset->rri_rdclass &&
	300	rr->type == T_SIG)
	301	rdata = &rrset->rri_sigs[index_sig++];
	302
	303	if (rdata) {
	304	rdata->rdi_length = rr->size;
	305	rdata->rdi_data = malloc(rr->size);
	306
	307	if (rdata->rdi_data == NULL) {
	308	result = ERRSET_NOMEMORY;
	309	goto fail;
	310	}
	311	memcpy(rdata->rdi_data, rr->rdata, rr->size);
	312	}
	313	}
	314
	315	*res = rrset;
	316	return (ERRSET_SUCCESS);
	317
	318	fail:
	319	if (rrset != NULL)
	320	freerrset(rrset);
	321	return (result);
	322	}
	323
	324	void
	325	freerrset(struct rrsetinfo *rrset)
	326	{
	327	u_int16_t i;
	328
	329	if (rrset == NULL)
	330	return;
	331
	332	if (rrset->rri_rdatas) {
	333	for (i = 0; i < rrset->rri_nrdatas; i++) {
	334	if (rrset->rri_rdatas[i].rdi_data == NULL)
	335	break;
	336	free(rrset->rri_rdatas[i].rdi_data);
	337	}
	338	free(rrset->rri_rdatas);
	339	}
	340
	341	if (rrset->rri_sigs) {
	342	for (i = 0; i < rrset->rri_nsigs; i++) {
	343	if (rrset->rri_sigs[i].rdi_data == NULL)
	344	break;
	345	free(rrset->rri_sigs[i].rdi_data);
	346	}
	347	free(rrset->rri_sigs);
	348	}
349
350	if (rrset->rri_name)
351	free(rrset->rri_name);
352	free(rrset);
353	}
354
355	/*
356	* DNS response parsing routines
357	*/
358	static struct dns_response *
359	parse_dns_response(const u_char *answer, int size)
360	{
361	struct dns_response *resp;
362	const u_char *cp;
363
364	/* allocate memory for the response */
365	resp = calloc(1, sizeof(*resp));
366	if (resp == NULL)
367	return (NULL);
368
369	/* initialize current pointer */
370	cp = answer;
371
372	/* copy header */
373	memcpy(&resp->header, cp, HFIXEDSZ);
374	cp += HFIXEDSZ;
375
376	/* fix header byte order */
377	resp->header.qdcount = ntohs(resp->header.qdcount);
378	resp->header.ancount = ntohs(resp->header.ancount);
379	resp->header.nscount = ntohs(resp->header.nscount);
380	resp->header.arcount = ntohs(resp->header.arcount);
381
382	/* there must be at least one query */
383	if (resp->header.qdcount < 1) {
384	free_dns_response(resp);
385	return (NULL);
386	}
387
388	/* parse query section */
389	resp->query = parse_dns_qsection(answer, size, &cp,
390	resp->header.qdcount);
391	if (resp->header.qdcount && resp->query == NULL) {
392	free_dns_response(resp);
393	return (NULL);
394	}
395
396	/* parse answer section */
397	resp->answer = parse_dns_rrsection(answer, size, &cp,
398	resp->header.ancount);
399	if (resp->header.ancount && resp->answer == NULL) {
400	free_dns_response(resp);
401	return (NULL);
402	}
403
404	/* parse authority section */
405	resp->authority = parse_dns_rrsection(answer, size, &cp,
406	resp->header.nscount);
407	if (resp->header.nscount && resp->authority == NULL) {
408	free_dns_response(resp);
409	return (NULL);
410	}
411
412	/* parse additional section */
413	resp->additional = parse_dns_rrsection(answer, size, &cp,
414	resp->header.arcount);
415	if (resp->header.arcount && resp->additional == NULL) {
416	free_dns_response(resp);
417	return (NULL);
418	}
419
420	return (resp);
421	}
422
423	static struct dns_query *
424	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
425	{
426	struct dns_query head, curr, *prev;
427	int i, length;
428	char name[MAXDNAME];
429
430	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
431
432	/* allocate and initialize struct */
433	curr = calloc(1, sizeof(struct dns_query));
434	if (curr == NULL) {
435	free_dns_query(head);
436	return (NULL);
437	}
438	if (head == NULL)
439	head = curr;
440	if (prev != NULL)
441	prev->next = curr;
442
443	/* name */
444	length = dn_expand(answer, answer + size, *cp, name,
445	sizeof(name));
446	if (length < 0) {
447	free_dns_query(head);
448	return (NULL);
449	}
450	curr->name = strdup(name);
451	if (curr->name == NULL) {
452	free_dns_query(head);
453	return (NULL);
454	}
455	*cp += length;
456
457	/* type */
458	curr->type = _getshort(*cp);
459	*cp += INT16SZ;
460
461	/* class */
462	curr->class = _getshort(*cp);
463	*cp += INT16SZ;
464	}
465
466	return (head);
467	}
468
469	static struct dns_rr *
470	parse_dns_rrsection(const u_char answer, int size, const u_char *cp, int count)
471	{
472	struct dns_rr head, curr, *prev;
473	int i, length;
474	char name[MAXDNAME];
475
476	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
477
478	/* allocate and initialize struct */
479	curr = calloc(1, sizeof(struct dns_rr));
480	if (curr == NULL) {
481	free_dns_rr(head);
482	return (NULL);
483	}
484	if (head == NULL)
485	head = curr;
486	if (prev != NULL)
487	prev->next = curr;
488
489	/* name */
490	length = dn_expand(answer, answer + size, *cp, name,
491	sizeof(name));
492	if (length < 0) {
493	free_dns_rr(head);
494	return (NULL);
495	}
496	curr->name = strdup(name);
497	if (curr->name == NULL) {
498	free_dns_rr(head);
499	return (NULL);
500	}
501	*cp += length;
502
503	/* type */
504	curr->type = _getshort(*cp);
505	*cp += INT16SZ;
506
507	/* class */
508	curr->class = _getshort(*cp);
509	*cp += INT16SZ;
510
511	/* ttl */
512	curr->ttl = _getlong(*cp);
513	*cp += INT32SZ;
514
515	/* rdata size */
516	curr->size = _getshort(*cp);
517	*cp += INT16SZ;
518
519	/* rdata itself */
520	curr->rdata = malloc(curr->size);
521	if (curr->rdata == NULL) {
522	free_dns_rr(head);
523	return (NULL);
524	}
525	memcpy(curr->rdata, *cp, curr->size);
526	*cp += curr->size;
527	}
528
529	return (head);
530	}
531
532	static void
533	free_dns_query(struct dns_query *p)
534	{
535	if (p == NULL)
536	return;
537
538	if (p->name)
539	free(p->name);
540	free_dns_query(p->next);
541	free(p);
542	}
543
544	static void
545	free_dns_rr(struct dns_rr *p)
546	{
547	if (p == NULL)
548	return;
549
550	if (p->name)
551	free(p->name);
552	if (p->rdata)
553	free(p->rdata);
554	free_dns_rr(p->next);
555	free(p);
556	}
557
558	static void
559	free_dns_response(struct dns_response *p)
560	{
561	if (p == NULL)
562	return;
563
564	free_dns_query(p->query);
565	free_dns_rr(p->answer);
566	free_dns_rr(p->authority);
567	free_dns_rr(p->additional);
568	free(p);
569	}
570
571	static int
572	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
573	{
574	int n = 0;
575
576	while(p) {
577	if (p->class == class && p->type == type)
578	n++;
579	p = p->next;
580	}
581
582	return (n);
583	}
584
cdd66111	585	#endif /* !defined(HAVE_GETRRSETBYNAME) */