[openssh.git] / openbsd-compat / 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"

/* #include "thread_private.h" */

#define ANSWER_BUFFER_SIZE 1024*64

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);
}
#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);
}
#endif

int
getrrsetbyname(const char *hostname, unsigned int rdclass,
    unsigned int rdtype, unsigned int flags,
    struct rrsetinfo **res)
{
	struct __res_state *_resp = &_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 ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
		result = ERRSET_FAIL;
		goto fail;
	}

#ifdef DEBUG
	_resp->options |= RES_DEBUG;
#endif /* DEBUG */

#ifdef RES_USE_DNSSEC
	/* turn on DNSSEC if EDNS0 is configured */
	if (_resp->options & RES_USE_EDNS0)
		_resp->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_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(DNS) && !defined(HAVE_GETRRSETBYNAME) */
Commit	Line	Data
bffa6723	1	/* $OpenBSD: getrrsetbyname.c,v 1.7 2003/03/07 07:34:14 itojun Exp $ */
4460d509	2
	3	/*
	4	* Copyright (c) 2001 Jakob Schlyter. All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	*
	10	* 1. Redistributions of source code must retain the above copyright
	11	* notice, this list of conditions and the following disclaimer.
	12	*
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	27	*/
	28
	29	/*
	30	* Portions Copyright (c) 1999-2001 Internet Software Consortium.
	31	*
	32	* Permission to use, copy, modify, and distribute this software for any
	33	* purpose with or without fee is hereby granted, provided that the above
	34	* copyright notice and this permission notice appear in all copies.
	35	*
	36	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
	37	* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
	38	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
	39	* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
	40	* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
	41	* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
	42	* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
	43	* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	44	*/
	45
	46	#include "includes.h"
	47
c31dc31c	48	#ifndef HAVE_GETRRSETBYNAME
4460d509	49
	50	#include "getrrsetbyname.h"
	51
bffa6723	52	/* #include "thread_private.h" */
bffa6723	53
4460d509	54	#define ANSWER_BUFFER_SIZE 1024*64
	55
	56	struct dns_query {
	57	char *name;
	58	u_int16_t type;
	59	u_int16_t class;
	60	struct dns_query *next;
	61	};
	62
	63	struct dns_rr {
	64	char *name;
	65	u_int16_t type;
	66	u_int16_t class;
	67	u_int16_t ttl;
	68	u_int16_t size;
	69	void *rdata;
	70	struct dns_rr *next;
	71	};
	72
	73	struct dns_response {
	74	HEADER header;
	75	struct dns_query *query;
	76	struct dns_rr *answer;
	77	struct dns_rr *authority;
	78	struct dns_rr *additional;
	79	};
	80
bffa6723	81	static struct dns_response parse_dns_response(const u_char , int);
	82	static struct dns_query parse_dns_qsection(const u_char , int,
	83	const u_char **, int);
	84	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
4460d509	85	int);
	86
	87	static void free_dns_query(struct dns_query *);
	88	static void free_dns_rr(struct dns_rr *);
	89	static void free_dns_response(struct dns_response *);
	90
	91	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	92
	93	/*
	94	* Inline versions of get/put short/long. Pointer is advanced.
	95	*
	96	* These macros demonstrate the property of C whereby it can be
	97	* portable or it can be elegant but rarely both.
	98	*/
	99
	100	#ifndef INT32SZ
	101	# define INT32SZ 4
	102	#endif
	103	#ifndef INT16SZ
	104	# define INT16SZ 2
	105	#endif
	106
	107	#ifndef GETSHORT
	108	#define GETSHORT(s, cp) { \
	109	register u_char t_cp = (u_char )(cp); \
	110	(s) = ((u_int16_t)t_cp[0] << 8) \
	111	\| ((u_int16_t)t_cp[1]) \
	112	; \
	113	(cp) += INT16SZ; \
	114	}
	115	#endif
	116
	117	#ifndef GETLONG
	118	#define GETLONG(l, cp) { \
	119	register u_char t_cp = (u_char )(cp); \
	120	(l) = ((u_int32_t)t_cp[0] << 24) \
	121	\| ((u_int32_t)t_cp[1] << 16) \
	122	\| ((u_int32_t)t_cp[2] << 8) \
	123	\| ((u_int32_t)t_cp[3]) \
	124	; \
	125	(cp) += INT32SZ; \
	126	}
	127	#endif
	128
	129	/*
	130	* Routines to insert/extract short/long's.
	131	*/
	132
252ff4df	133	#ifndef HAVE__GETSHORT
4460d509	134	static u_int16_t
	135	_getshort(msgp)
	136	register const u_char *msgp;
	137	{
	138	register u_int16_t u;
	139
	140	GETSHORT(u, msgp);
	141	return (u);
	142	}
252ff4df	143	#endif
4460d509	144
252ff4df	145	#ifndef HAVE__GETLONG
4460d509	146	static u_int32_t
	147	_getlong(msgp)
	148	register const u_char *msgp;
	149	{
	150	register u_int32_t u;
	151
	152	GETLONG(u, msgp);
	153	return (u);
	154	}
252ff4df	155	#endif
4460d509	156
	157	int
	158	getrrsetbyname(const char *hostname, unsigned int rdclass,
	159	unsigned int rdtype, unsigned int flags,
	160	struct rrsetinfo **res)
	161	{
bffa6723	162	struct __res_state *_resp = &_res;
4460d509	163	int result;
	164	struct rrsetinfo *rrset = NULL;
	165	struct dns_response *response;
	166	struct dns_rr *rr;
	167	struct rdatainfo *rdata;
bffa6723	168	int length;
	169	unsigned int index_ans, index_sig;
	170	u_char answer[ANSWER_BUFFER_SIZE];
4460d509	171
	172	/* check for invalid class and type */
	173	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	174	result = ERRSET_INVAL;
	175	goto fail;
	176	}
	177
	178	/* don't allow queries of class or type ANY */
	179	if (rdclass == 0xff \|\| rdtype == 0xff) {
	180	result = ERRSET_INVAL;
	181	goto fail;
	182	}
	183
	184	/* don't allow flags yet, unimplemented */
	185	if (flags) {
	186	result = ERRSET_INVAL;
	187	goto fail;
	188	}
	189
	190	/* initialize resolver */
bffa6723	191	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
4460d509	192	result = ERRSET_FAIL;
	193	goto fail;
	194	}
	195
	196	#ifdef DEBUG
bffa6723	197	_resp->options \|= RES_DEBUG;
4460d509	198	#endif /* DEBUG */
	199
	200	#ifdef RES_USE_DNSSEC
	201	/* turn on DNSSEC if EDNS0 is configured */
bffa6723	202	if (_resp->options & RES_USE_EDNS0)
bffa6723	203	_resp->options \|= RES_USE_DNSSEC;
4460d509	204	#endif /* RES_USE_DNSEC */
	205
	206	/* make query */
bffa6723	207	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
bffa6723	208	answer, sizeof(answer));
4460d509	209	if (length < 0) {
	210	switch(h_errno) {
	211	case HOST_NOT_FOUND:
	212	result = ERRSET_NONAME;
	213	goto fail;
	214	case NO_DATA:
	215	result = ERRSET_NODATA;
	216	goto fail;
	217	default:
	218	result = ERRSET_FAIL;
	219	goto fail;
	220	}
	221	}
	222
	223	/* parse result */
	224	response = parse_dns_response(answer, length);
	225	if (response == NULL) {
	226	result = ERRSET_FAIL;
	227	goto fail;
	228	}
	229
	230	if (response->header.qdcount != 1) {
	231	result = ERRSET_FAIL;
	232	goto fail;
	233	}
	234
	235	/* initialize rrset */
	236	rrset = calloc(1, sizeof(struct rrsetinfo));
	237	if (rrset == NULL) {
	238	result = ERRSET_NOMEMORY;
	239	goto fail;
	240	}
	241	rrset->rri_rdclass = response->query->class;
	242	rrset->rri_rdtype = response->query->type;
	243	rrset->rri_ttl = response->answer->ttl;
	244	rrset->rri_nrdatas = response->header.ancount;
	245
078ec045	246	#ifdef HAVE_HEADER_AD
4460d509	247	/* check for authenticated data */
	248	if (response->header.ad == 1)
	249	rrset->rri_flags \|= RRSET_VALIDATED;
078ec045	250	#endif
4460d509	251
	252	/* copy name from answer section */
	253	length = strlen(response->answer->name);
	254	rrset->rri_name = malloc(length + 1);
	255	if (rrset->rri_name == NULL) {
	256	result = ERRSET_NOMEMORY;
	257	goto fail;
	258	}
	259	strlcpy(rrset->rri_name, response->answer->name, length + 1);
	260
	261	/* count answers */
	262	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	263	rrset->rri_rdtype);
	264	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	265	T_SIG);
	266
	267	/* allocate memory for answers */
	268	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	269	sizeof(struct rdatainfo));
	270	if (rrset->rri_rdatas == NULL) {
	271	result = ERRSET_NOMEMORY;
	272	goto fail;
	273	}
	274
	275	/* allocate memory for signatures */
	276	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
	277	if (rrset->rri_sigs == NULL) {
	278	result = ERRSET_NOMEMORY;
	279	goto fail;
	280	}
	281
	282	/* copy answers & signatures */
	283	for (rr = response->answer, index_ans = 0, index_sig = 0;
	284	rr; rr = rr->next) {
	285
	286	rdata = NULL;
	287
	288	if (rr->class == rrset->rri_rdclass &&
	289	rr->type == rrset->rri_rdtype)
	290	rdata = &rrset->rri_rdatas[index_ans++];
	291
	292	if (rr->class == rrset->rri_rdclass &&
	293	rr->type == T_SIG)
	294	rdata = &rrset->rri_sigs[index_sig++];
	295
	296	if (rdata) {
	297	rdata->rdi_length = rr->size;
	298	rdata->rdi_data = malloc(rr->size);
	299
	300	if (rdata->rdi_data == NULL) {
	301	result = ERRSET_NOMEMORY;
	302	goto fail;
	303	}
	304	memcpy(rdata->rdi_data, rr->rdata, rr->size);
	305	}
	306	}
	307
	308	*res = rrset;
	309	return (ERRSET_SUCCESS);
	310
	311	fail:
	312	if (rrset != NULL)
	313	freerrset(rrset);
	314	return (result);
315	}
316
317	void
318	freerrset(struct rrsetinfo *rrset)
319	{
320	u_int16_t i;
321
322	if (rrset == NULL)
323	return;
324
325	if (rrset->rri_rdatas) {
326	for (i = 0; i < rrset->rri_nrdatas; i++) {
327	if (rrset->rri_rdatas[i].rdi_data == NULL)
328	break;
329	free(rrset->rri_rdatas[i].rdi_data);
330	}
331	free(rrset->rri_rdatas);
332	}
333
334	if (rrset->rri_sigs) {
335	for (i = 0; i < rrset->rri_nsigs; i++) {
336	if (rrset->rri_sigs[i].rdi_data == NULL)
337	break;
338	free(rrset->rri_sigs[i].rdi_data);
339	}
340	free(rrset->rri_sigs);
341	}
342
343	if (rrset->rri_name)
344	free(rrset->rri_name);
345	free(rrset);
346	}
347
348	/*
349	* DNS response parsing routines
350	*/
351	static struct dns_response *
bffa6723	352	parse_dns_response(const u_char *answer, int size)
4460d509	353	{
4460d509	354	struct dns_response *resp;
bffa6723	355	const u_char *cp;
4460d509	356
	357	/* allocate memory for the response */
	358	resp = calloc(1, sizeof(*resp));
	359	if (resp == NULL)
	360	return (NULL);
	361
	362	/* initialize current pointer */
	363	cp = answer;
	364
	365	/* copy header */
	366	memcpy(&resp->header, cp, HFIXEDSZ);
	367	cp += HFIXEDSZ;
	368
	369	/* fix header byte order */
	370	resp->header.qdcount = ntohs(resp->header.qdcount);
	371	resp->header.ancount = ntohs(resp->header.ancount);
	372	resp->header.nscount = ntohs(resp->header.nscount);
	373	resp->header.arcount = ntohs(resp->header.arcount);
	374
	375	/* there must be at least one query */
	376	if (resp->header.qdcount < 1) {
	377	free_dns_response(resp);
	378	return (NULL);
	379	}
	380
	381	/* parse query section */
	382	resp->query = parse_dns_qsection(answer, size, &cp,
	383	resp->header.qdcount);
	384	if (resp->header.qdcount && resp->query == NULL) {
	385	free_dns_response(resp);
	386	return (NULL);
	387	}
	388
	389	/* parse answer section */
	390	resp->answer = parse_dns_rrsection(answer, size, &cp,
	391	resp->header.ancount);
	392	if (resp->header.ancount && resp->answer == NULL) {
	393	free_dns_response(resp);
	394	return (NULL);
	395	}
	396
	397	/* parse authority section */
	398	resp->authority = parse_dns_rrsection(answer, size, &cp,
	399	resp->header.nscount);
	400	if (resp->header.nscount && resp->authority == NULL) {
	401	free_dns_response(resp);
	402	return (NULL);
	403	}
	404
	405	/* parse additional section */
	406	resp->additional = parse_dns_rrsection(answer, size, &cp,
	407	resp->header.arcount);
	408	if (resp->header.arcount && resp->additional == NULL) {
	409	free_dns_response(resp);
	410	return (NULL);
	411	}
	412
	413	return (resp);
	414	}
	415
	416	static struct dns_query *
bffa6723	417	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
4460d509	418	{
	419	struct dns_query head, curr, *prev;
	420	int i, length;
	421	char name[MAXDNAME];
	422
	423	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	424
	425	/* allocate and initialize struct */
	426	curr = calloc(1, sizeof(struct dns_query));
	427	if (curr == NULL) {
	428	free_dns_query(head);
	429	return (NULL);
	430	}
	431	if (head == NULL)
	432	head = curr;
	433	if (prev != NULL)
	434	prev->next = curr;
	435
	436	/* name */
	437	length = dn_expand(answer, answer + size, *cp, name,
	438	sizeof(name));
	439	if (length < 0) {
	440	free_dns_query(head);
	441	return (NULL);
	442	}
	443	curr->name = strdup(name);
	444	if (curr->name == NULL) {
	445	free_dns_query(head);
	446	return (NULL);
	447	}
	448	*cp += length;
	449
	450	/* type */
	451	curr->type = _getshort(*cp);
	452	*cp += INT16SZ;
	453
	454	/* class */
	455	curr->class = _getshort(*cp);
	456	*cp += INT16SZ;
	457	}
	458
	459	return (head);
	460	}
	461
	462	static struct dns_rr *
bffa6723	463	parse_dns_rrsection(const u_char answer, int size, const u_char *cp, int count)
4460d509	464	{
	465	struct dns_rr head, curr, *prev;
	466	int i, length;
	467	char name[MAXDNAME];
	468
	469	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	470
	471	/* allocate and initialize struct */
	472	curr = calloc(1, sizeof(struct dns_rr));
	473	if (curr == NULL) {
	474	free_dns_rr(head);
	475	return (NULL);
	476	}
	477	if (head == NULL)
	478	head = curr;
	479	if (prev != NULL)
	480	prev->next = curr;
	481
	482	/* name */
	483	length = dn_expand(answer, answer + size, *cp, name,
	484	sizeof(name));
	485	if (length < 0) {
	486	free_dns_rr(head);
	487	return (NULL);
	488	}
	489	curr->name = strdup(name);
	490	if (curr->name == NULL) {
	491	free_dns_rr(head);
	492	return (NULL);
	493	}
	494	*cp += length;
	495
	496	/* type */
	497	curr->type = _getshort(*cp);
	498	*cp += INT16SZ;
	499
	500	/* class */
	501	curr->class = _getshort(*cp);
	502	*cp += INT16SZ;
	503
	504	/* ttl */
	505	curr->ttl = _getlong(*cp);
	506	*cp += INT32SZ;
	507
	508	/* rdata size */
	509	curr->size = _getshort(*cp);
	510	*cp += INT16SZ;
	511
	512	/* rdata itself */
	513	curr->rdata = malloc(curr->size);
	514	if (curr->rdata == NULL) {
	515	free_dns_rr(head);
	516	return (NULL);
	517	}
	518	memcpy(curr->rdata, *cp, curr->size);
	519	*cp += curr->size;
	520	}
	521
	522	return (head);
	523	}
	524
	525	static void
	526	free_dns_query(struct dns_query *p)
	527	{
528	if (p == NULL)
529	return;
530
531	if (p->name)
532	free(p->name);
533	free_dns_query(p->next);
534	free(p);
535	}
536
537	static void
538	free_dns_rr(struct dns_rr *p)
539	{
540	if (p == NULL)
541	return;
542
543	if (p->name)
544	free(p->name);
545	if (p->rdata)
546	free(p->rdata);
547	free_dns_rr(p->next);
548	free(p);
549	}
550
551	static void
552	free_dns_response(struct dns_response *p)
553	{
554	if (p == NULL)
555	return;
556
557	free_dns_query(p->query);
558	free_dns_rr(p->answer);
559	free_dns_rr(p->authority);
560	free_dns_rr(p->additional);
561	free(p);
562	}
563
564	static int
565	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
566	{
567	int n = 0;
568
569	while(p) {
570	if (p->class == class && p->type == type)
571	n++;
572	p = p->next;
573	}
574
575	return (n);
576	}
577
67467c30	578	#endif /* defined(DNS) && !defined(HAVE_GETRRSETBYNAME) */