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

/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu 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.
 */

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

#include "includes.h"

#ifndef HAVE_GETRRSETBYNAME

#include "getrrsetbyname.h"

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

/* We don't need multithread support here */
#ifdef _THREAD_PRIVATE
# undef _THREAD_PRIVATE
#endif
#define _THREAD_PRIVATE(a,b,c) (c)

/* to avoid conflicts where a platform already has _res */
#define _res	_compat_res

struct __res_state _res;

/* Necessary functions and macros */

/*
 * 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

/* ************** */

#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);

int
getrrsetbyname(const char *hostname, unsigned int rdclass,
    unsigned int rdtype, unsigned int flags,
    struct rrsetinfo **res)
{
	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
	int result;
	struct rrsetinfo *rrset = NULL;
	struct dns_response *response = NULL;
	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 */
	rrset->rri_name = strdup(response->answer->name);
	if (rrset->rri_name == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}

	/* 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);
		}
	}
	free_dns_response(response);

	*res = rrset;
	return (ERRSET_SUCCESS);

fail:
	if (rrset != NULL)
		freerrset(rrset);
	if (response != NULL)
		free_dns_response(response);
	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
ebb049f1	1	/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu 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
f6d4fb87	46	/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
f6d4fb87	47
4460d509	48	#include "includes.h"
4460d509	49
c31dc31c	50	#ifndef HAVE_GETRRSETBYNAME
4460d509	51
	52	#include "getrrsetbyname.h"
	53
4d29d2d3	54	#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
41e0e158	55	extern int h_errno;
	56	#endif
	57
ebb049f1	58	/* We don't need multithread support here */
	59	#ifdef _THREAD_PRIVATE
	60	# undef _THREAD_PRIVATE
	61	#endif
	62	#define _THREAD_PRIVATE(a,b,c) (c)
a048aeba	63
	64	/* to avoid conflicts where a platform already has _res */
	65	#define _res _compat_res
	66
ebb049f1	67	struct __res_state _res;
4460d509	68
ebb049f1	69	/* Necessary functions and macros */
4460d509	70
	71	/*
	72	* Inline versions of get/put short/long. Pointer is advanced.
	73	*
	74	* These macros demonstrate the property of C whereby it can be
	75	* portable or it can be elegant but rarely both.
	76	*/
	77
	78	#ifndef INT32SZ
	79	# define INT32SZ 4
	80	#endif
	81	#ifndef INT16SZ
	82	# define INT16SZ 2
	83	#endif
	84
	85	#ifndef GETSHORT
	86	#define GETSHORT(s, cp) { \
	87	register u_char t_cp = (u_char )(cp); \
	88	(s) = ((u_int16_t)t_cp[0] << 8) \
	89	\| ((u_int16_t)t_cp[1]) \
	90	; \
	91	(cp) += INT16SZ; \
	92	}
	93	#endif
	94
	95	#ifndef GETLONG
	96	#define GETLONG(l, cp) { \
	97	register u_char t_cp = (u_char )(cp); \
	98	(l) = ((u_int32_t)t_cp[0] << 24) \
	99	\| ((u_int32_t)t_cp[1] << 16) \
	100	\| ((u_int32_t)t_cp[2] << 8) \
	101	\| ((u_int32_t)t_cp[3]) \
	102	; \
	103	(cp) += INT32SZ; \
	104	}
	105	#endif
	106
	107	/*
	108	* Routines to insert/extract short/long's.
	109	*/
	110
252ff4df	111	#ifndef HAVE__GETSHORT
4460d509	112	static u_int16_t
	113	_getshort(msgp)
	114	register const u_char *msgp;
	115	{
	116	register u_int16_t u;
	117
	118	GETSHORT(u, msgp);
	119	return (u);
	120	}
03f5da4c	121	#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
03f5da4c	122	u_int16_t _getshort(register const u_char *);
252ff4df	123	#endif
4460d509	124
252ff4df	125	#ifndef HAVE__GETLONG
4460d509	126	static u_int32_t
	127	_getlong(msgp)
	128	register const u_char *msgp;
	129	{
	130	register u_int32_t u;
	131
	132	GETLONG(u, msgp);
	133	return (u);
	134	}
03f5da4c	135	#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
03f5da4c	136	u_int32_t _getlong(register const u_char *);
252ff4df	137	#endif
4460d509	138
ebb049f1	139	/* ************** */
	140
	141	#define ANSWER_BUFFER_SIZE 1024*64
	142
	143	struct dns_query {
	144	char *name;
	145	u_int16_t type;
	146	u_int16_t class;
	147	struct dns_query *next;
	148	};
	149
	150	struct dns_rr {
	151	char *name;
	152	u_int16_t type;
	153	u_int16_t class;
	154	u_int16_t ttl;
	155	u_int16_t size;
	156	void *rdata;
	157	struct dns_rr *next;
	158	};
	159
	160	struct dns_response {
	161	HEADER header;
	162	struct dns_query *query;
	163	struct dns_rr *answer;
	164	struct dns_rr *authority;
	165	struct dns_rr *additional;
	166	};
	167
	168	static struct dns_response parse_dns_response(const u_char , int);
	169	static struct dns_query parse_dns_qsection(const u_char , int,
	170	const u_char **, int);
	171	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
	172	int);
	173
	174	static void free_dns_query(struct dns_query *);
	175	static void free_dns_rr(struct dns_rr *);
	176	static void free_dns_response(struct dns_response *);
	177
	178	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	179
4460d509	180	int
	181	getrrsetbyname(const char *hostname, unsigned int rdclass,
	182	unsigned int rdtype, unsigned int flags,
	183	struct rrsetinfo **res)
	184	{
ebb049f1	185	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
4460d509	186	int result;
4460d509	187	struct rrsetinfo *rrset = NULL;
ebb049f1	188	struct dns_response *response = NULL;
4460d509	189	struct dns_rr *rr;
4460d509	190	struct rdatainfo *rdata;
bffa6723	191	int length;
	192	unsigned int index_ans, index_sig;
	193	u_char answer[ANSWER_BUFFER_SIZE];
4460d509	194
	195	/* check for invalid class and type */
	196	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	197	result = ERRSET_INVAL;
	198	goto fail;
	199	}
	200
	201	/* don't allow queries of class or type ANY */
	202	if (rdclass == 0xff \|\| rdtype == 0xff) {
	203	result = ERRSET_INVAL;
	204	goto fail;
	205	}
	206
	207	/* don't allow flags yet, unimplemented */
	208	if (flags) {
	209	result = ERRSET_INVAL;
	210	goto fail;
	211	}
	212
	213	/* initialize resolver */
ebb049f1	214	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
4460d509	215	result = ERRSET_FAIL;
	216	goto fail;
	217	}
	218
	219	#ifdef DEBUG
ebb049f1	220	_resp->options \|= RES_DEBUG;
4460d509	221	#endif /* DEBUG */
	222
	223	#ifdef RES_USE_DNSSEC
	224	/* turn on DNSSEC if EDNS0 is configured */
ebb049f1	225	if (_resp->options & RES_USE_EDNS0)
ebb049f1	226	_resp->options \|= RES_USE_DNSSEC;
4460d509	227	#endif /* RES_USE_DNSEC */
	228
	229	/* make query */
bffa6723	230	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
bffa6723	231	answer, sizeof(answer));
4460d509	232	if (length < 0) {
	233	switch(h_errno) {
	234	case HOST_NOT_FOUND:
	235	result = ERRSET_NONAME;
	236	goto fail;
	237	case NO_DATA:
	238	result = ERRSET_NODATA;
	239	goto fail;
	240	default:
	241	result = ERRSET_FAIL;
	242	goto fail;
	243	}
	244	}
	245
	246	/* parse result */
	247	response = parse_dns_response(answer, length);
	248	if (response == NULL) {
	249	result = ERRSET_FAIL;
	250	goto fail;
	251	}
	252
	253	if (response->header.qdcount != 1) {
	254	result = ERRSET_FAIL;
	255	goto fail;
	256	}
	257
	258	/* initialize rrset */
	259	rrset = calloc(1, sizeof(struct rrsetinfo));
	260	if (rrset == NULL) {
	261	result = ERRSET_NOMEMORY;
	262	goto fail;
	263	}
	264	rrset->rri_rdclass = response->query->class;
	265	rrset->rri_rdtype = response->query->type;
	266	rrset->rri_ttl = response->answer->ttl;
	267	rrset->rri_nrdatas = response->header.ancount;
	268
4162eae5	269	#ifdef HAVE_HEADER_AD
4460d509	270	/* check for authenticated data */
	271	if (response->header.ad == 1)
	272	rrset->rri_flags \|= RRSET_VALIDATED;
4162eae5	273	#endif
4460d509	274
4460d509	275	/* copy name from answer section */
ebb049f1	276	rrset->rri_name = strdup(response->answer->name);
4460d509	277	if (rrset->rri_name == NULL) {
	278	result = ERRSET_NOMEMORY;
	279	goto fail;
	280	}
4460d509	281
	282	/* count answers */
	283	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	284	rrset->rri_rdtype);
	285	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	286	T_SIG);
	287
	288	/* allocate memory for answers */
	289	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	290	sizeof(struct rdatainfo));
	291	if (rrset->rri_rdatas == NULL) {
	292	result = ERRSET_NOMEMORY;
	293	goto fail;
	294	}
	295
	296	/* allocate memory for signatures */
	297	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
ebb049f1	298	if (rrset->rri_sigs == NULL) {
4460d509	299	result = ERRSET_NOMEMORY;
	300	goto fail;
	301	}
	302
	303	/* copy answers & signatures */
	304	for (rr = response->answer, index_ans = 0, index_sig = 0;
	305	rr; rr = rr->next) {
	306
	307	rdata = NULL;
	308
	309	if (rr->class == rrset->rri_rdclass &&
	310	rr->type == rrset->rri_rdtype)
	311	rdata = &rrset->rri_rdatas[index_ans++];
	312
	313	if (rr->class == rrset->rri_rdclass &&
	314	rr->type == T_SIG)
	315	rdata = &rrset->rri_sigs[index_sig++];
	316
	317	if (rdata) {
	318	rdata->rdi_length = rr->size;
	319	rdata->rdi_data = malloc(rr->size);
	320
	321	if (rdata->rdi_data == NULL) {
	322	result = ERRSET_NOMEMORY;
	323	goto fail;
	324	}
	325	memcpy(rdata->rdi_data, rr->rdata, rr->size);
	326	}
	327	}
ebb049f1	328	free_dns_response(response);
4460d509	329
	330	*res = rrset;
	331	return (ERRSET_SUCCESS);
	332
	333	fail:
	334	if (rrset != NULL)
	335	freerrset(rrset);
ebb049f1	336	if (response != NULL)
ebb049f1	337	free_dns_response(response);
4460d509	338	return (result);
	339	}
	340
	341	void
	342	freerrset(struct rrsetinfo *rrset)
	343	{
	344	u_int16_t i;
	345
	346	if (rrset == NULL)
	347	return;
	348
	349	if (rrset->rri_rdatas) {
	350	for (i = 0; i < rrset->rri_nrdatas; i++) {
	351	if (rrset->rri_rdatas[i].rdi_data == NULL)
	352	break;
	353	free(rrset->rri_rdatas[i].rdi_data);
	354	}
	355	free(rrset->rri_rdatas);
	356	}
	357
	358	if (rrset->rri_sigs) {
	359	for (i = 0; i < rrset->rri_nsigs; i++) {
	360	if (rrset->rri_sigs[i].rdi_data == NULL)
	361	break;
	362	free(rrset->rri_sigs[i].rdi_data);
	363	}
	364	free(rrset->rri_sigs);
	365	}
	366
	367	if (rrset->rri_name)
	368	free(rrset->rri_name);
	369	free(rrset);
	370	}
	371
	372	/*
	373	* DNS response parsing routines
	374	*/
	375	static struct dns_response *
bffa6723	376	parse_dns_response(const u_char *answer, int size)
4460d509	377	{
4460d509	378	struct dns_response *resp;
bffa6723	379	const u_char *cp;
4460d509	380
	381	/* allocate memory for the response */
	382	resp = calloc(1, sizeof(*resp));
	383	if (resp == NULL)
	384	return (NULL);
	385
	386	/* initialize current pointer */
	387	cp = answer;
	388
	389	/* copy header */
	390	memcpy(&resp->header, cp, HFIXEDSZ);
	391	cp += HFIXEDSZ;
	392
	393	/* fix header byte order */
	394	resp->header.qdcount = ntohs(resp->header.qdcount);
	395	resp->header.ancount = ntohs(resp->header.ancount);
	396	resp->header.nscount = ntohs(resp->header.nscount);
	397	resp->header.arcount = ntohs(resp->header.arcount);
	398
	399	/* there must be at least one query */
	400	if (resp->header.qdcount < 1) {
	401	free_dns_response(resp);
	402	return (NULL);
	403	}
	404
	405	/* parse query section */
	406	resp->query = parse_dns_qsection(answer, size, &cp,
	407	resp->header.qdcount);
	408	if (resp->header.qdcount && resp->query == NULL) {
	409	free_dns_response(resp);
	410	return (NULL);
	411	}
	412
	413	/* parse answer section */
	414	resp->answer = parse_dns_rrsection(answer, size, &cp,
	415	resp->header.ancount);
	416	if (resp->header.ancount && resp->answer == NULL) {
	417	free_dns_response(resp);
	418	return (NULL);
	419	}
	420
	421	/* parse authority section */
	422	resp->authority = parse_dns_rrsection(answer, size, &cp,
	423	resp->header.nscount);
	424	if (resp->header.nscount && resp->authority == NULL) {
	425	free_dns_response(resp);
	426	return (NULL);
	427	}
	428
	429	/* parse additional section */
	430	resp->additional = parse_dns_rrsection(answer, size, &cp,
	431	resp->header.arcount);
	432	if (resp->header.arcount && resp->additional == NULL) {
	433	free_dns_response(resp);
	434	return (NULL);
	435	}
	436
	437	return (resp);
	438	}
	439
	440	static struct dns_query *
bffa6723	441	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
4460d509	442	{
	443	struct dns_query head, curr, *prev;
	444	int i, length;
	445	char name[MAXDNAME];
	446
	447	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	448
	449	/* allocate and initialize struct */
	450	curr = calloc(1, sizeof(struct dns_query));
	451	if (curr == NULL) {
	452	free_dns_query(head);
	453	return (NULL);
	454	}
	455	if (head == NULL)
	456	head = curr;
	457	if (prev != NULL)
	458	prev->next = curr;
	459
	460	/* name */
	461	length = dn_expand(answer, answer + size, *cp, name,
	462	sizeof(name));
	463	if (length < 0) {
	464	free_dns_query(head);
	465	return (NULL);
	466	}
	467	curr->name = strdup(name);
	468	if (curr->name == NULL) {
	469	free_dns_query(head);
	470	return (NULL);
	471	}
	472	*cp += length;
	473
	474	/* type */
	475	curr->type = _getshort(*cp);
	476	*cp += INT16SZ;
	477
	478	/* class */
	479	curr->class = _getshort(*cp);
	480	*cp += INT16SZ;
	481	}
	482
	483	return (head);
	484	}
	485
	486	static struct dns_rr *
ebb049f1	487	parse_dns_rrsection(const u_char answer, int size, const u_char *cp,
ebb049f1	488	int count)
4460d509	489	{
	490	struct dns_rr head, curr, *prev;
	491	int i, length;
	492	char name[MAXDNAME];
	493
	494	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	495
	496	/* allocate and initialize struct */
	497	curr = calloc(1, sizeof(struct dns_rr));
	498	if (curr == NULL) {
	499	free_dns_rr(head);
	500	return (NULL);
	501	}
	502	if (head == NULL)
	503	head = curr;
	504	if (prev != NULL)
	505	prev->next = curr;
	506
	507	/* name */
	508	length = dn_expand(answer, answer + size, *cp, name,
	509	sizeof(name));
	510	if (length < 0) {
	511	free_dns_rr(head);
	512	return (NULL);
	513	}
	514	curr->name = strdup(name);
	515	if (curr->name == NULL) {
	516	free_dns_rr(head);
	517	return (NULL);
	518	}
	519	*cp += length;
	520
	521	/* type */
	522	curr->type = _getshort(*cp);
	523	*cp += INT16SZ;
	524
	525	/* class */
	526	curr->class = _getshort(*cp);
	527	*cp += INT16SZ;
	528
	529	/* ttl */
	530	curr->ttl = _getlong(*cp);
	531	*cp += INT32SZ;
	532
	533	/* rdata size */
	534	curr->size = _getshort(*cp);
	535	*cp += INT16SZ;
	536
	537	/* rdata itself */
	538	curr->rdata = malloc(curr->size);
	539	if (curr->rdata == NULL) {
	540	free_dns_rr(head);
	541	return (NULL);
	542	}
	543	memcpy(curr->rdata, *cp, curr->size);
	544	*cp += curr->size;
	545	}
	546
	547	return (head);
	548	}
	549
	550	static void
	551	free_dns_query(struct dns_query *p)
	552	{
553	if (p == NULL)
554	return;
555
556	if (p->name)
557	free(p->name);
558	free_dns_query(p->next);
559	free(p);
560	}
561
562	static void
563	free_dns_rr(struct dns_rr *p)
564	{
565	if (p == NULL)
566	return;
567
568	if (p->name)
569	free(p->name);
570	if (p->rdata)
571	free(p->rdata);
572	free_dns_rr(p->next);
573	free(p);
574	}
575
576	static void
577	free_dns_response(struct dns_response *p)
578	{
579	if (p == NULL)
580	return;
581
582	free_dns_query(p->query);
583	free_dns_rr(p->answer);
584	free_dns_rr(p->authority);
585	free_dns_rr(p->additional);
586	free(p);
587	}
588
589	static int
590	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
591	{
592	int n = 0;
593
594	while(p) {
595	if (p->class == class && p->type == type)
596	n++;
597	p = p->next;
598	}
599
600	return (n);
601	}
602
c369b7c3	603	#endif /* !defined(HAVE_GETRRSETBYNAME) */