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