[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"

#if defined(DNS) && !defined(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.
 */

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

	GETSHORT(u, msgp);
	return (u);
}

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

	GETLONG(u, msgp);
	return (u);
}

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;

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

	/* 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
67467c30	48	#if defined(DNS) && !defined(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
	133	static u_int16_t
	134	_getshort(msgp)
	135	register const u_char *msgp;
	136	{
	137	register u_int16_t u;
	138
	139	GETSHORT(u, msgp);
	140	return (u);
	141	}
	142
	143	static u_int32_t
	144	_getlong(msgp)
	145	register const u_char *msgp;
	146	{
	147	register u_int32_t u;
	148
149	GETLONG(u, msgp);
150	return (u);
151	}
152
153	int
154	getrrsetbyname(const char *hostname, unsigned int rdclass,
155	unsigned int rdtype, unsigned int flags,
156	struct rrsetinfo **res)
157	{
bffa6723	158	struct __res_state *_resp = &_res;
4460d509	159	int result;
	160	struct rrsetinfo *rrset = NULL;
	161	struct dns_response *response;
	162	struct dns_rr *rr;
	163	struct rdatainfo *rdata;
bffa6723	164	int length;
	165	unsigned int index_ans, index_sig;
	166	u_char answer[ANSWER_BUFFER_SIZE];
4460d509	167
	168	/* check for invalid class and type */
	169	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	170	result = ERRSET_INVAL;
	171	goto fail;
	172	}
	173
	174	/* don't allow queries of class or type ANY */
	175	if (rdclass == 0xff \|\| rdtype == 0xff) {
	176	result = ERRSET_INVAL;
	177	goto fail;
	178	}
	179
	180	/* don't allow flags yet, unimplemented */
	181	if (flags) {
	182	result = ERRSET_INVAL;
	183	goto fail;
	184	}
	185
	186	/* initialize resolver */
bffa6723	187	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
4460d509	188	result = ERRSET_FAIL;
	189	goto fail;
	190	}
	191
	192	#ifdef DEBUG
bffa6723	193	_resp->options \|= RES_DEBUG;
4460d509	194	#endif /* DEBUG */
	195
	196	#ifdef RES_USE_DNSSEC
	197	/* turn on DNSSEC if EDNS0 is configured */
bffa6723	198	if (_resp->options & RES_USE_EDNS0)
bffa6723	199	_resp->options \|= RES_USE_DNSSEC;
4460d509	200	#endif /* RES_USE_DNSEC */
	201
	202	/* make query */
bffa6723	203	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
bffa6723	204	answer, sizeof(answer));
4460d509	205	if (length < 0) {
	206	switch(h_errno) {
	207	case HOST_NOT_FOUND:
	208	result = ERRSET_NONAME;
	209	goto fail;
	210	case NO_DATA:
	211	result = ERRSET_NODATA;
	212	goto fail;
	213	default:
	214	result = ERRSET_FAIL;
	215	goto fail;
	216	}
	217	}
	218
	219	/* parse result */
	220	response = parse_dns_response(answer, length);
	221	if (response == NULL) {
	222	result = ERRSET_FAIL;
	223	goto fail;
	224	}
	225
	226	if (response->header.qdcount != 1) {
	227	result = ERRSET_FAIL;
	228	goto fail;
	229	}
	230
	231	/* initialize rrset */
	232	rrset = calloc(1, sizeof(struct rrsetinfo));
	233	if (rrset == NULL) {
	234	result = ERRSET_NOMEMORY;
	235	goto fail;
	236	}
	237	rrset->rri_rdclass = response->query->class;
	238	rrset->rri_rdtype = response->query->type;
	239	rrset->rri_ttl = response->answer->ttl;
	240	rrset->rri_nrdatas = response->header.ancount;
	241
	242	/* check for authenticated data */
	243	if (response->header.ad == 1)
	244	rrset->rri_flags \|= RRSET_VALIDATED;
	245
	246	/* copy name from answer section */
	247	length = strlen(response->answer->name);
	248	rrset->rri_name = malloc(length + 1);
	249	if (rrset->rri_name == NULL) {
	250	result = ERRSET_NOMEMORY;
	251	goto fail;
	252	}
	253	strlcpy(rrset->rri_name, response->answer->name, length + 1);
	254
	255	/* count answers */
	256	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	257	rrset->rri_rdtype);
	258	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	259	T_SIG);
	260
	261	/* allocate memory for answers */
	262	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	263	sizeof(struct rdatainfo));
	264	if (rrset->rri_rdatas == NULL) {
	265	result = ERRSET_NOMEMORY;
	266	goto fail;
	267	}
	268
269	/* allocate memory for signatures */
270	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
271	if (rrset->rri_sigs == NULL) {
272	result = ERRSET_NOMEMORY;
273	goto fail;
274	}
275
276	/* copy answers & signatures */
277	for (rr = response->answer, index_ans = 0, index_sig = 0;
278	rr; rr = rr->next) {
279
280	rdata = NULL;
281
282	if (rr->class == rrset->rri_rdclass &&
283	rr->type == rrset->rri_rdtype)
284	rdata = &rrset->rri_rdatas[index_ans++];
285
286	if (rr->class == rrset->rri_rdclass &&
287	rr->type == T_SIG)
288	rdata = &rrset->rri_sigs[index_sig++];
289
290	if (rdata) {
291	rdata->rdi_length = rr->size;
292	rdata->rdi_data = malloc(rr->size);
293
294	if (rdata->rdi_data == NULL) {
295	result = ERRSET_NOMEMORY;
296	goto fail;
297	}
298	memcpy(rdata->rdi_data, rr->rdata, rr->size);
299	}
300	}
301
302	*res = rrset;
303	return (ERRSET_SUCCESS);
304
305	fail:
306	if (rrset != NULL)
307	freerrset(rrset);
308	return (result);
309	}
310
311	void
312	freerrset(struct rrsetinfo *rrset)
313	{
314	u_int16_t i;
315
316	if (rrset == NULL)
317	return;
318
319	if (rrset->rri_rdatas) {
320	for (i = 0; i < rrset->rri_nrdatas; i++) {
321	if (rrset->rri_rdatas[i].rdi_data == NULL)
322	break;
323	free(rrset->rri_rdatas[i].rdi_data);
324	}
325	free(rrset->rri_rdatas);
326	}
327
328	if (rrset->rri_sigs) {
329	for (i = 0; i < rrset->rri_nsigs; i++) {
330	if (rrset->rri_sigs[i].rdi_data == NULL)
331	break;
332	free(rrset->rri_sigs[i].rdi_data);
333	}
334	free(rrset->rri_sigs);
335	}
336
337	if (rrset->rri_name)
338	free(rrset->rri_name);
339	free(rrset);
340	}
341
342	/*
343	* DNS response parsing routines
344	*/
345	static struct dns_response *
bffa6723	346	parse_dns_response(const u_char *answer, int size)
4460d509	347	{
4460d509	348	struct dns_response *resp;
bffa6723	349	const u_char *cp;
4460d509	350
	351	/* allocate memory for the response */
	352	resp = calloc(1, sizeof(*resp));
	353	if (resp == NULL)
	354	return (NULL);
	355
	356	/* initialize current pointer */
	357	cp = answer;
	358
	359	/* copy header */
	360	memcpy(&resp->header, cp, HFIXEDSZ);
	361	cp += HFIXEDSZ;
	362
	363	/* fix header byte order */
	364	resp->header.qdcount = ntohs(resp->header.qdcount);
	365	resp->header.ancount = ntohs(resp->header.ancount);
	366	resp->header.nscount = ntohs(resp->header.nscount);
	367	resp->header.arcount = ntohs(resp->header.arcount);
	368
	369	/* there must be at least one query */
	370	if (resp->header.qdcount < 1) {
	371	free_dns_response(resp);
	372	return (NULL);
	373	}
	374
	375	/* parse query section */
	376	resp->query = parse_dns_qsection(answer, size, &cp,
	377	resp->header.qdcount);
	378	if (resp->header.qdcount && resp->query == NULL) {
	379	free_dns_response(resp);
	380	return (NULL);
	381	}
	382
	383	/* parse answer section */
	384	resp->answer = parse_dns_rrsection(answer, size, &cp,
	385	resp->header.ancount);
	386	if (resp->header.ancount && resp->answer == NULL) {
	387	free_dns_response(resp);
	388	return (NULL);
	389	}
	390
	391	/* parse authority section */
	392	resp->authority = parse_dns_rrsection(answer, size, &cp,
	393	resp->header.nscount);
	394	if (resp->header.nscount && resp->authority == NULL) {
	395	free_dns_response(resp);
	396	return (NULL);
	397	}
	398
	399	/* parse additional section */
	400	resp->additional = parse_dns_rrsection(answer, size, &cp,
	401	resp->header.arcount);
	402	if (resp->header.arcount && resp->additional == NULL) {
	403	free_dns_response(resp);
	404	return (NULL);
	405	}
	406
	407	return (resp);
	408	}
	409
	410	static struct dns_query *
bffa6723	411	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
4460d509	412	{
	413	struct dns_query head, curr, *prev;
	414	int i, length;
	415	char name[MAXDNAME];
	416
	417	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	418
	419	/* allocate and initialize struct */
	420	curr = calloc(1, sizeof(struct dns_query));
	421	if (curr == NULL) {
	422	free_dns_query(head);
	423	return (NULL);
	424	}
	425	if (head == NULL)
	426	head = curr;
	427	if (prev != NULL)
	428	prev->next = curr;
	429
	430	/* name */
	431	length = dn_expand(answer, answer + size, *cp, name,
	432	sizeof(name));
	433	if (length < 0) {
	434	free_dns_query(head);
	435	return (NULL);
	436	}
	437	curr->name = strdup(name);
	438	if (curr->name == NULL) {
	439	free_dns_query(head);
	440	return (NULL);
	441	}
	442	*cp += length;
	443
	444	/* type */
	445	curr->type = _getshort(*cp);
	446	*cp += INT16SZ;
	447
	448	/* class */
	449	curr->class = _getshort(*cp);
	450	*cp += INT16SZ;
	451	}
	452
	453	return (head);
	454	}
	455
	456	static struct dns_rr *
bffa6723	457	parse_dns_rrsection(const u_char answer, int size, const u_char *cp, int count)
4460d509	458	{
	459	struct dns_rr head, curr, *prev;
	460	int i, length;
	461	char name[MAXDNAME];
	462
	463	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	464
	465	/* allocate and initialize struct */
	466	curr = calloc(1, sizeof(struct dns_rr));
	467	if (curr == NULL) {
	468	free_dns_rr(head);
	469	return (NULL);
	470	}
	471	if (head == NULL)
	472	head = curr;
	473	if (prev != NULL)
	474	prev->next = curr;
	475
	476	/* name */
	477	length = dn_expand(answer, answer + size, *cp, name,
	478	sizeof(name));
	479	if (length < 0) {
	480	free_dns_rr(head);
	481	return (NULL);
	482	}
	483	curr->name = strdup(name);
	484	if (curr->name == NULL) {
	485	free_dns_rr(head);
	486	return (NULL);
	487	}
	488	*cp += length;
	489
	490	/* type */
	491	curr->type = _getshort(*cp);
	492	*cp += INT16SZ;
	493
	494	/* class */
	495	curr->class = _getshort(*cp);
	496	*cp += INT16SZ;
	497
	498	/* ttl */
	499	curr->ttl = _getlong(*cp);
	500	*cp += INT32SZ;
	501
	502	/* rdata size */
	503	curr->size = _getshort(*cp);
	504	*cp += INT16SZ;
	505
	506	/* rdata itself */
	507	curr->rdata = malloc(curr->size);
	508	if (curr->rdata == NULL) {
	509	free_dns_rr(head);
	510	return (NULL);
	511	}
	512	memcpy(curr->rdata, *cp, curr->size);
	513	*cp += curr->size;
	514	}
	515
	516	return (head);
	517	}
	518
	519	static void
	520	free_dns_query(struct dns_query *p)
	521	{
522	if (p == NULL)
523	return;
524
525	if (p->name)
526	free(p->name);
527	free_dns_query(p->next);
528	free(p);
529	}
530
531	static void
532	free_dns_rr(struct dns_rr *p)
533	{
534	if (p == NULL)
535	return;
536
537	if (p->name)
538	free(p->name);
539	if (p->rdata)
540	free(p->rdata);
541	free_dns_rr(p->next);
542	free(p);
543	}
544
545	static void
546	free_dns_response(struct dns_response *p)
547	{
548	if (p == NULL)
549	return;
550
551	free_dns_query(p->query);
552	free_dns_rr(p->answer);
553	free_dns_rr(p->authority);
554	free_dns_rr(p->additional);
555	free(p);
556	}
557
558	static int
559	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
560	{
561	int n = 0;
562
563	while(p) {
564	if (p->class == class && p->type == type)
565	n++;
566	p = p->next;
567	}
568
569	return (n);
570	}
571
67467c30	572	#endif /* defined(DNS) && !defined(HAVE_GETRRSETBYNAME) */