[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

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_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
	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
	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 **,
	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	#ifndef HAVE__GETSHORT
134	static u_int16_t
135	_getshort(msgp)
136	register const u_char *msgp;
137	{
138	register u_int16_t u;
139
140	GETSHORT(u, msgp);
141	return (u);
142	}
143	#endif
144
145	#ifndef HAVE__GETLONG
146	static u_int32_t
147	_getlong(msgp)
148	register const u_char *msgp;
149	{
150	register u_int32_t u;
151
152	GETLONG(u, msgp);
153	return (u);
154	}
155	#endif
156
157	int
158	getrrsetbyname(const char *hostname, unsigned int rdclass,
159	unsigned int rdtype, unsigned int flags,
160	struct rrsetinfo **res)
161	{
0fff78ff	162	int result;
	163	struct rrsetinfo *rrset = NULL;
	164	struct dns_response *response;
	165	struct dns_rr *rr;
	166	struct rdatainfo *rdata;
	167	int length;
	168	unsigned int index_ans, index_sig;
	169	u_char answer[ANSWER_BUFFER_SIZE];
	170
	171	/* check for invalid class and type */
	172	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	173	result = ERRSET_INVAL;
	174	goto fail;
	175	}
	176
	177	/* don't allow queries of class or type ANY */
	178	if (rdclass == 0xff \|\| rdtype == 0xff) {
	179	result = ERRSET_INVAL;
	180	goto fail;
	181	}
	182
	183	/* don't allow flags yet, unimplemented */
	184	if (flags) {
	185	result = ERRSET_INVAL;
	186	goto fail;
	187	}
	188
	189	/* initialize resolver */
cdd66111	190	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
0fff78ff	191	result = ERRSET_FAIL;
	192	goto fail;
	193	}
	194
	195	#ifdef DEBUG
cdd66111	196	_res.options \|= RES_DEBUG;
0fff78ff	197	#endif /* DEBUG */
	198
	199	#ifdef RES_USE_DNSSEC
	200	/* turn on DNSSEC if EDNS0 is configured */
cdd66111	201	if (_res.options & RES_USE_EDNS0)
cdd66111	202	_res.options \|= RES_USE_DNSSEC;
0fff78ff	203	#endif /* RES_USE_DNSEC */
	204
	205	/* make query */
	206	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
	207	answer, sizeof(answer));
	208	if (length < 0) {
	209	switch(h_errno) {
	210	case HOST_NOT_FOUND:
	211	result = ERRSET_NONAME;
	212	goto fail;
	213	case NO_DATA:
	214	result = ERRSET_NODATA;
	215	goto fail;
	216	default:
	217	result = ERRSET_FAIL;
	218	goto fail;
	219	}
	220	}
	221
	222	/* parse result */
	223	response = parse_dns_response(answer, length);
	224	if (response == NULL) {
	225	result = ERRSET_FAIL;
	226	goto fail;
	227	}
	228
	229	if (response->header.qdcount != 1) {
	230	result = ERRSET_FAIL;
	231	goto fail;
	232	}
	233
	234	/* initialize rrset */
	235	rrset = calloc(1, sizeof(struct rrsetinfo));
	236	if (rrset == NULL) {
	237	result = ERRSET_NOMEMORY;
	238	goto fail;
	239	}
	240	rrset->rri_rdclass = response->query->class;
	241	rrset->rri_rdtype = response->query->type;
	242	rrset->rri_ttl = response->answer->ttl;
	243	rrset->rri_nrdatas = response->header.ancount;
	244
	245	#ifdef HAVE_HEADER_AD
	246	/* check for authenticated data */
	247	if (response->header.ad == 1)
	248	rrset->rri_flags \|= RRSET_VALIDATED;
	249	#endif
	250
	251	/* copy name from answer section */
	252	length = strlen(response->answer->name);
	253	rrset->rri_name = malloc(length + 1);
	254	if (rrset->rri_name == NULL) {
	255	result = ERRSET_NOMEMORY;
	256	goto fail;
	257	}
	258	strlcpy(rrset->rri_name, response->answer->name, length + 1);
	259
	260	/* count answers */
	261	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	262	rrset->rri_rdtype);
	263	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	264	T_SIG);
	265
	266	/* allocate memory for answers */
267	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
268	sizeof(struct rdatainfo));
269	if (rrset->rri_rdatas == NULL) {
270	result = ERRSET_NOMEMORY;
271	goto fail;
272	}
273
274	/* allocate memory for signatures */
275	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
276	if (rrset->rri_sigs == NULL) {
277	result = ERRSET_NOMEMORY;
278	goto fail;
279	}
280
281	/* copy answers & signatures */
282	for (rr = response->answer, index_ans = 0, index_sig = 0;
283	rr; rr = rr->next) {
284
285	rdata = NULL;
286
287	if (rr->class == rrset->rri_rdclass &&
288	rr->type == rrset->rri_rdtype)
289	rdata = &rrset->rri_rdatas[index_ans++];
290
291	if (rr->class == rrset->rri_rdclass &&
292	rr->type == T_SIG)
293	rdata = &rrset->rri_sigs[index_sig++];
294
295	if (rdata) {
296	rdata->rdi_length = rr->size;
297	rdata->rdi_data = malloc(rr->size);
298
299	if (rdata->rdi_data == NULL) {
300	result = ERRSET_NOMEMORY;
301	goto fail;
302	}
303	memcpy(rdata->rdi_data, rr->rdata, rr->size);
304	}
305	}
306
307	*res = rrset;
308	return (ERRSET_SUCCESS);
309
310	fail:
311	if (rrset != NULL)
312	freerrset(rrset);
313	return (result);
314	}
315
316	void
317	freerrset(struct rrsetinfo *rrset)
318	{
319	u_int16_t i;
320
321	if (rrset == NULL)
322	return;
323
324	if (rrset->rri_rdatas) {
325	for (i = 0; i < rrset->rri_nrdatas; i++) {
326	if (rrset->rri_rdatas[i].rdi_data == NULL)
327	break;
328	free(rrset->rri_rdatas[i].rdi_data);
329	}
330	free(rrset->rri_rdatas);
331	}
332
333	if (rrset->rri_sigs) {
334	for (i = 0; i < rrset->rri_nsigs; i++) {
335	if (rrset->rri_sigs[i].rdi_data == NULL)
336	break;
337	free(rrset->rri_sigs[i].rdi_data);
338	}
339	free(rrset->rri_sigs);
340	}
341
342	if (rrset->rri_name)
343	free(rrset->rri_name);
344	free(rrset);
345	}
346
347	/*
348	* DNS response parsing routines
349	*/
350	static struct dns_response *
351	parse_dns_response(const u_char *answer, int size)
352	{
353	struct dns_response *resp;
354	const u_char *cp;
355
356	/* allocate memory for the response */
357	resp = calloc(1, sizeof(*resp));
358	if (resp == NULL)
359	return (NULL);
360
361	/* initialize current pointer */
362	cp = answer;
363
364	/* copy header */
365	memcpy(&resp->header, cp, HFIXEDSZ);
366	cp += HFIXEDSZ;
367
368	/* fix header byte order */
369	resp->header.qdcount = ntohs(resp->header.qdcount);
370	resp->header.ancount = ntohs(resp->header.ancount);
371	resp->header.nscount = ntohs(resp->header.nscount);
372	resp->header.arcount = ntohs(resp->header.arcount);
373
374	/* there must be at least one query */
375	if (resp->header.qdcount < 1) {
376	free_dns_response(resp);
377	return (NULL);
378	}
379
380	/* parse query section */
381	resp->query = parse_dns_qsection(answer, size, &cp,
382	resp->header.qdcount);
383	if (resp->header.qdcount && resp->query == NULL) {
384	free_dns_response(resp);
385	return (NULL);
386	}
387
388	/* parse answer section */
389	resp->answer = parse_dns_rrsection(answer, size, &cp,
390	resp->header.ancount);
391	if (resp->header.ancount && resp->answer == NULL) {
392	free_dns_response(resp);
393	return (NULL);
394	}
395
396	/* parse authority section */
397	resp->authority = parse_dns_rrsection(answer, size, &cp,
398	resp->header.nscount);
399	if (resp->header.nscount && resp->authority == NULL) {
400	free_dns_response(resp);
401	return (NULL);
402	}
403
404	/* parse additional section */
405	resp->additional = parse_dns_rrsection(answer, size, &cp,
406	resp->header.arcount);
407	if (resp->header.arcount && resp->additional == NULL) {
408	free_dns_response(resp);
409	return (NULL);
410	}
411
412	return (resp);
413	}
414
415	static struct dns_query *
416	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
417	{
418	struct dns_query head, curr, *prev;
419	int i, length;
420	char name[MAXDNAME];
421
422	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
423
424	/* allocate and initialize struct */
425	curr = calloc(1, sizeof(struct dns_query));
426	if (curr == NULL) {
427	free_dns_query(head);
428	return (NULL);
429	}
430	if (head == NULL)
431	head = curr;
432	if (prev != NULL)
433	prev->next = curr;
434
435	/* name */
436	length = dn_expand(answer, answer + size, *cp, name,
437	sizeof(name));
438	if (length < 0) {
439	free_dns_query(head);
440	return (NULL);
441	}
442	curr->name = strdup(name);
443	if (curr->name == NULL) {
444	free_dns_query(head);
445	return (NULL);
446	}
447	*cp += length;
448
449	/* type */
450	curr->type = _getshort(*cp);
451	*cp += INT16SZ;
452
453	/* class */
454	curr->class = _getshort(*cp);
455	*cp += INT16SZ;
456	}
457
458	return (head);
459	}
460
461	static struct dns_rr *
462	parse_dns_rrsection(const u_char answer, int size, const u_char *cp, int count)
463	{
464	struct dns_rr head, curr, *prev;
465	int i, length;
466	char name[MAXDNAME];
467
468	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
469
470	/* allocate and initialize struct */
471	curr = calloc(1, sizeof(struct dns_rr));
472	if (curr == NULL) {
473	free_dns_rr(head);
474	return (NULL);
475	}
476	if (head == NULL)
477	head = curr;
478	if (prev != NULL)
479	prev->next = curr;
480
481	/* name */
482	length = dn_expand(answer, answer + size, *cp, name,
483	sizeof(name));
484	if (length < 0) {
485	free_dns_rr(head);
486	return (NULL);
487	}
488	curr->name = strdup(name);
489	if (curr->name == NULL) {
490	free_dns_rr(head);
491	return (NULL);
492	}
493	*cp += length;
494
495	/* type */
496	curr->type = _getshort(*cp);
497	*cp += INT16SZ;
498
499	/* class */
500	curr->class = _getshort(*cp);
501	*cp += INT16SZ;
502
503	/* ttl */
504	curr->ttl = _getlong(*cp);
505	*cp += INT32SZ;
506
507	/* rdata size */
508	curr->size = _getshort(*cp);
509	*cp += INT16SZ;
510
511	/* rdata itself */
512	curr->rdata = malloc(curr->size);
513	if (curr->rdata == NULL) {
514	free_dns_rr(head);
515	return (NULL);
516	}
517	memcpy(curr->rdata, *cp, curr->size);
518	*cp += curr->size;
519	}
520
521	return (head);
522	}
523
524	static void
525	free_dns_query(struct dns_query *p)
526	{
527	if (p == NULL)
528	return;
529
530	if (p->name)
531	free(p->name);
532	free_dns_query(p->next);
533	free(p);
534	}
535
536	static void
537	free_dns_rr(struct dns_rr *p)
538	{
539	if (p == NULL)
540	return;
541
542	if (p->name)
543	free(p->name);
544	if (p->rdata)
545	free(p->rdata);
546	free_dns_rr(p->next);
547	free(p);
548	}
549
550	static void
551	free_dns_response(struct dns_response *p)
552	{
553	if (p == NULL)
554	return;
555
556	free_dns_query(p->query);
557	free_dns_rr(p->answer);
558	free_dns_rr(p->authority);
559	free_dns_rr(p->additional);
560	free(p);
561	}
562
563	static int
564	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
565	{
566	int n = 0;
567
568	while(p) {
569	if (p->class == class && p->type == type)
570	n++;
571	p = p->next;
572	}
573
574	return (n);
575	}
576
cdd66111	577	#endif /* !defined(HAVE_GETRRSETBYNAME) */