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

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

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

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

/*
 * Portions Copyright (c) 1999-2001 Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "includes.h"

#ifndef HAVE_GETRRSETBYNAME

#include "getrrsetbyname.h"

#define ANSWER_BUFFER_SIZE 1024*64

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

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

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

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

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

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

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

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

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

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

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

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

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

	GETSHORT(u, msgp);
	return (u);
}
#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)
{
	int result;
	struct rrsetinfo *rrset = NULL;
	struct dns_response *response;
	struct dns_rr *rr;
	struct rdatainfo *rdata;
	int length;
	unsigned int index_ans, index_sig;
	u_char answer[ANSWER_BUFFER_SIZE];

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

		rdata = NULL;

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

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

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

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

	*res = rrset;
	return (ERRSET_SUCCESS);

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

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

	if (rrset == NULL)
		return;

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

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

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

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

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

	/* initialize current pointer */
	cp = answer;

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

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

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

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

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

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

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

	return (resp);
}

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

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

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

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

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

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

	return (head);
}

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

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

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

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

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

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

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

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

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

	return (head);
}

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

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

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

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

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

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

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

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

	return (n);
}

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