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

/* $OpenBSD: getrrsetbyname.c,v 1.11 2007/10/11 18:36:41 jakob 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 <stdlib.h>
#include <string.h>

#include <netinet/in.h>
#include <arpa/inet.h>

#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)

#ifndef HAVE__RES_EXTERN
struct __res_state _res;
#endif

/* 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 0xffff

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_RRSIG);

	/* 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 */
	if (rrset->rri_nsigs > 0) {
		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_RRSIG)
			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
e74dc197	1	/* $OpenBSD: getrrsetbyname.c,v 1.11 2007/10/11 18:36:41 jakob Exp $ */
c9307018	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
08822d99	46	/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
08822d99	47
c9307018	48	#include "includes.h"
c9307018	49
540d72c3	50	#ifndef HAVE_GETRRSETBYNAME
c9307018	51
30460aeb	52	#include <stdlib.h>
	53	#include <string.h>
	54
	55	#include <netinet/in.h>
	56	#include <arpa/inet.h>
	57
c9307018	58	#include "getrrsetbyname.h"
c9307018	59
7e82606e	60	#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO
	61	extern int h_errno;
	62	#endif
	63
08822d99	64	/* We don't need multithread support here */
	65	#ifdef _THREAD_PRIVATE
	66	# undef _THREAD_PRIVATE
	67	#endif
	68	#define _THREAD_PRIVATE(a,b,c) (c)
30460aeb	69
fa0f0f45	70	#ifndef HAVE__RES_EXTERN
08822d99	71	struct __res_state _res;
fa0f0f45	72	#endif
c9307018	73
08822d99	74	/* Necessary functions and macros */
c9307018	75
	76	/*
	77	* Inline versions of get/put short/long. Pointer is advanced.
	78	*
	79	* These macros demonstrate the property of C whereby it can be
	80	* portable or it can be elegant but rarely both.
	81	*/
	82
	83	#ifndef INT32SZ
	84	# define INT32SZ 4
	85	#endif
	86	#ifndef INT16SZ
	87	# define INT16SZ 2
	88	#endif
	89
	90	#ifndef GETSHORT
	91	#define GETSHORT(s, cp) { \
	92	register u_char t_cp = (u_char )(cp); \
	93	(s) = ((u_int16_t)t_cp[0] << 8) \
	94	\| ((u_int16_t)t_cp[1]) \
	95	; \
	96	(cp) += INT16SZ; \
	97	}
	98	#endif
	99
	100	#ifndef GETLONG
	101	#define GETLONG(l, cp) { \
	102	register u_char t_cp = (u_char )(cp); \
	103	(l) = ((u_int32_t)t_cp[0] << 24) \
	104	\| ((u_int32_t)t_cp[1] << 16) \
	105	\| ((u_int32_t)t_cp[2] << 8) \
	106	\| ((u_int32_t)t_cp[3]) \
	107	; \
	108	(cp) += INT32SZ; \
	109	}
	110	#endif
	111
	112	/*
	113	* Routines to insert/extract short/long's.
	114	*/
	115
	116	#ifndef HAVE__GETSHORT
	117	static u_int16_t
	118	_getshort(msgp)
	119	register const u_char *msgp;
	120	{
	121	register u_int16_t u;
	122
	123	GETSHORT(u, msgp);
	124	return (u);
	125	}
2ce0bfe4	126	#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
2ce0bfe4	127	u_int16_t _getshort(register const u_char *);
c9307018	128	#endif
	129
	130	#ifndef HAVE__GETLONG
	131	static u_int32_t
	132	_getlong(msgp)
	133	register const u_char *msgp;
	134	{
	135	register u_int32_t u;
	136
	137	GETLONG(u, msgp);
	138	return (u);
	139	}
2ce0bfe4	140	#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
2ce0bfe4	141	u_int32_t _getlong(register const u_char *);
c9307018	142	#endif
c9307018	143
08822d99	144	/* ************** */
08822d99	145
b5afdff5	146	#define ANSWER_BUFFER_SIZE 0xffff
08822d99	147
	148	struct dns_query {
	149	char *name;
	150	u_int16_t type;
	151	u_int16_t class;
	152	struct dns_query *next;
	153	};
	154
	155	struct dns_rr {
	156	char *name;
	157	u_int16_t type;
	158	u_int16_t class;
	159	u_int16_t ttl;
	160	u_int16_t size;
	161	void *rdata;
	162	struct dns_rr *next;
	163	};
	164
	165	struct dns_response {
	166	HEADER header;
	167	struct dns_query *query;
	168	struct dns_rr *answer;
	169	struct dns_rr *authority;
	170	struct dns_rr *additional;
	171	};
	172
	173	static struct dns_response parse_dns_response(const u_char , int);
	174	static struct dns_query parse_dns_qsection(const u_char , int,
	175	const u_char **, int);
	176	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
	177	int);
	178
	179	static void free_dns_query(struct dns_query *);
	180	static void free_dns_rr(struct dns_rr *);
	181	static void free_dns_response(struct dns_response *);
	182
	183	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	184
c9307018	185	int
	186	getrrsetbyname(const char *hostname, unsigned int rdclass,
	187	unsigned int rdtype, unsigned int flags,
	188	struct rrsetinfo **res)
	189	{
08822d99	190	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
c9307018	191	int result;
c9307018	192	struct rrsetinfo *rrset = NULL;
08822d99	193	struct dns_response *response = NULL;
c9307018	194	struct dns_rr *rr;
	195	struct rdatainfo *rdata;
	196	int length;
	197	unsigned int index_ans, index_sig;
	198	u_char answer[ANSWER_BUFFER_SIZE];
	199
	200	/* check for invalid class and type */
	201	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	202	result = ERRSET_INVAL;
	203	goto fail;
	204	}
	205
	206	/* don't allow queries of class or type ANY */
	207	if (rdclass == 0xff \|\| rdtype == 0xff) {
	208	result = ERRSET_INVAL;
	209	goto fail;
	210	}
	211
	212	/* don't allow flags yet, unimplemented */
	213	if (flags) {
	214	result = ERRSET_INVAL;
	215	goto fail;
	216	}
	217
	218	/* initialize resolver */
08822d99	219	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
c9307018	220	result = ERRSET_FAIL;
	221	goto fail;
	222	}
	223
	224	#ifdef DEBUG
08822d99	225	_resp->options \|= RES_DEBUG;
c9307018	226	#endif /* DEBUG */
	227
	228	#ifdef RES_USE_DNSSEC
	229	/* turn on DNSSEC if EDNS0 is configured */
08822d99	230	if (_resp->options & RES_USE_EDNS0)
08822d99	231	_resp->options \|= RES_USE_DNSSEC;
c9307018	232	#endif /* RES_USE_DNSEC */
	233
	234	/* make query */
	235	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
	236	answer, sizeof(answer));
	237	if (length < 0) {
	238	switch(h_errno) {
	239	case HOST_NOT_FOUND:
	240	result = ERRSET_NONAME;
	241	goto fail;
	242	case NO_DATA:
	243	result = ERRSET_NODATA;
	244	goto fail;
	245	default:
	246	result = ERRSET_FAIL;
	247	goto fail;
	248	}
	249	}
	250
	251	/* parse result */
	252	response = parse_dns_response(answer, length);
	253	if (response == NULL) {
	254	result = ERRSET_FAIL;
	255	goto fail;
	256	}
	257
	258	if (response->header.qdcount != 1) {
	259	result = ERRSET_FAIL;
	260	goto fail;
	261	}
	262
	263	/* initialize rrset */
	264	rrset = calloc(1, sizeof(struct rrsetinfo));
	265	if (rrset == NULL) {
	266	result = ERRSET_NOMEMORY;
	267	goto fail;
	268	}
	269	rrset->rri_rdclass = response->query->class;
	270	rrset->rri_rdtype = response->query->type;
	271	rrset->rri_ttl = response->answer->ttl;
	272	rrset->rri_nrdatas = response->header.ancount;
	273
	274	#ifdef HAVE_HEADER_AD
	275	/* check for authenticated data */
	276	if (response->header.ad == 1)
	277	rrset->rri_flags \|= RRSET_VALIDATED;
	278	#endif
	279
	280	/* copy name from answer section */
08822d99	281	rrset->rri_name = strdup(response->answer->name);
c9307018	282	if (rrset->rri_name == NULL) {
	283	result = ERRSET_NOMEMORY;
	284	goto fail;
	285	}
c9307018	286
	287	/* count answers */
	288	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	289	rrset->rri_rdtype);
	290	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
e74dc197	291	T_RRSIG);
c9307018	292
	293	/* allocate memory for answers */
	294	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	295	sizeof(struct rdatainfo));
	296	if (rrset->rri_rdatas == NULL) {
	297	result = ERRSET_NOMEMORY;
	298	goto fail;
	299	}
	300
	301	/* allocate memory for signatures */
0b90ac93	302	if (rrset->rri_nsigs > 0) {
	303	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
	304	if (rrset->rri_sigs == NULL) {
	305	result = ERRSET_NOMEMORY;
	306	goto fail;
	307	}
c9307018	308	}
	309
	310	/* copy answers & signatures */
	311	for (rr = response->answer, index_ans = 0, index_sig = 0;
	312	rr; rr = rr->next) {
	313
	314	rdata = NULL;
	315
	316	if (rr->class == rrset->rri_rdclass &&
	317	rr->type == rrset->rri_rdtype)
	318	rdata = &rrset->rri_rdatas[index_ans++];
	319
	320	if (rr->class == rrset->rri_rdclass &&
e74dc197	321	rr->type == T_RRSIG)
c9307018	322	rdata = &rrset->rri_sigs[index_sig++];
	323
	324	if (rdata) {
	325	rdata->rdi_length = rr->size;
	326	rdata->rdi_data = malloc(rr->size);
	327
	328	if (rdata->rdi_data == NULL) {
	329	result = ERRSET_NOMEMORY;
	330	goto fail;
	331	}
	332	memcpy(rdata->rdi_data, rr->rdata, rr->size);
	333	}
	334	}
08822d99	335	free_dns_response(response);
c9307018	336
	337	*res = rrset;
	338	return (ERRSET_SUCCESS);
	339
	340	fail:
	341	if (rrset != NULL)
	342	freerrset(rrset);
08822d99	343	if (response != NULL)
08822d99	344	free_dns_response(response);
c9307018	345	return (result);
	346	}
	347
	348	void
	349	freerrset(struct rrsetinfo *rrset)
	350	{
	351	u_int16_t i;
	352
	353	if (rrset == NULL)
	354	return;
	355
	356	if (rrset->rri_rdatas) {
	357	for (i = 0; i < rrset->rri_nrdatas; i++) {
	358	if (rrset->rri_rdatas[i].rdi_data == NULL)
	359	break;
	360	free(rrset->rri_rdatas[i].rdi_data);
	361	}
	362	free(rrset->rri_rdatas);
	363	}
	364
	365	if (rrset->rri_sigs) {
	366	for (i = 0; i < rrset->rri_nsigs; i++) {
	367	if (rrset->rri_sigs[i].rdi_data == NULL)
	368	break;
	369	free(rrset->rri_sigs[i].rdi_data);
	370	}
	371	free(rrset->rri_sigs);
	372	}
	373
	374	if (rrset->rri_name)
	375	free(rrset->rri_name);
	376	free(rrset);
	377	}
	378
	379	/*
	380	* DNS response parsing routines
	381	*/
	382	static struct dns_response *
	383	parse_dns_response(const u_char *answer, int size)
	384	{
	385	struct dns_response *resp;
	386	const u_char *cp;
	387
	388	/* allocate memory for the response */
	389	resp = calloc(1, sizeof(*resp));
	390	if (resp == NULL)
	391	return (NULL);
	392
	393	/* initialize current pointer */
	394	cp = answer;
	395
	396	/* copy header */
	397	memcpy(&resp->header, cp, HFIXEDSZ);
	398	cp += HFIXEDSZ;
	399
	400	/* fix header byte order */
	401	resp->header.qdcount = ntohs(resp->header.qdcount);
	402	resp->header.ancount = ntohs(resp->header.ancount);
	403	resp->header.nscount = ntohs(resp->header.nscount);
	404	resp->header.arcount = ntohs(resp->header.arcount);
	405
	406	/* there must be at least one query */
	407	if (resp->header.qdcount < 1) {
	408	free_dns_response(resp);
409	return (NULL);
410	}
411
412	/* parse query section */
413	resp->query = parse_dns_qsection(answer, size, &cp,
414	resp->header.qdcount);
415	if (resp->header.qdcount && resp->query == NULL) {
416	free_dns_response(resp);
417	return (NULL);
418	}
419
420	/* parse answer section */
421	resp->answer = parse_dns_rrsection(answer, size, &cp,
422	resp->header.ancount);
423	if (resp->header.ancount && resp->answer == NULL) {
424	free_dns_response(resp);
425	return (NULL);
426	}
427
428	/* parse authority section */
429	resp->authority = parse_dns_rrsection(answer, size, &cp,
430	resp->header.nscount);
431	if (resp->header.nscount && resp->authority == NULL) {
432	free_dns_response(resp);
433	return (NULL);
434	}
435
436	/* parse additional section */
437	resp->additional = parse_dns_rrsection(answer, size, &cp,
438	resp->header.arcount);
439	if (resp->header.arcount && resp->additional == NULL) {
440	free_dns_response(resp);
441	return (NULL);
442	}
443
444	return (resp);
445	}
446
447	static struct dns_query *
448	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
449	{
450	struct dns_query head, curr, *prev;
451	int i, length;
452	char name[MAXDNAME];
453
454	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
455
456	/* allocate and initialize struct */
457	curr = calloc(1, sizeof(struct dns_query));
458	if (curr == NULL) {
459	free_dns_query(head);
460	return (NULL);
461	}
462	if (head == NULL)
463	head = curr;
464	if (prev != NULL)
465	prev->next = curr;
466
467	/* name */
468	length = dn_expand(answer, answer + size, *cp, name,
469	sizeof(name));
470	if (length < 0) {
471	free_dns_query(head);
472	return (NULL);
473	}
474	curr->name = strdup(name);
475	if (curr->name == NULL) {
476	free_dns_query(head);
477	return (NULL);
478	}
479	*cp += length;
480
481	/* type */
482	curr->type = _getshort(*cp);
483	*cp += INT16SZ;
484
485	/* class */
486	curr->class = _getshort(*cp);
487	*cp += INT16SZ;
488	}
489
490	return (head);
491	}
492
493	static struct dns_rr *
08822d99	494	parse_dns_rrsection(const u_char answer, int size, const u_char *cp,
08822d99	495	int count)
c9307018	496	{
	497	struct dns_rr head, curr, *prev;
	498	int i, length;
	499	char name[MAXDNAME];
	500
	501	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	502
	503	/* allocate and initialize struct */
	504	curr = calloc(1, sizeof(struct dns_rr));
	505	if (curr == NULL) {
	506	free_dns_rr(head);
	507	return (NULL);
	508	}
	509	if (head == NULL)
	510	head = curr;
	511	if (prev != NULL)
	512	prev->next = curr;
	513
	514	/* name */
	515	length = dn_expand(answer, answer + size, *cp, name,
	516	sizeof(name));
	517	if (length < 0) {
	518	free_dns_rr(head);
	519	return (NULL);
	520	}
	521	curr->name = strdup(name);
	522	if (curr->name == NULL) {
	523	free_dns_rr(head);
	524	return (NULL);
	525	}
	526	*cp += length;
	527
	528	/* type */
	529	curr->type = _getshort(*cp);
	530	*cp += INT16SZ;
	531
	532	/* class */
	533	curr->class = _getshort(*cp);
	534	*cp += INT16SZ;
	535
	536	/* ttl */
	537	curr->ttl = _getlong(*cp);
	538	*cp += INT32SZ;
	539
	540	/* rdata size */
	541	curr->size = _getshort(*cp);
	542	*cp += INT16SZ;
	543
	544	/* rdata itself */
	545	curr->rdata = malloc(curr->size);
	546	if (curr->rdata == NULL) {
	547	free_dns_rr(head);
	548	return (NULL);
	549	}
	550	memcpy(curr->rdata, *cp, curr->size);
	551	*cp += curr->size;
	552	}
	553
	554	return (head);
	555	}
	556
	557	static void
	558	free_dns_query(struct dns_query *p)
	559	{
560	if (p == NULL)
561	return;
562
563	if (p->name)
564	free(p->name);
565	free_dns_query(p->next);
566	free(p);
567	}
568
569	static void
570	free_dns_rr(struct dns_rr *p)
571	{
572	if (p == NULL)
573	return;
574
575	if (p->name)
576	free(p->name);
577	if (p->rdata)
578	free(p->rdata);
579	free_dns_rr(p->next);
580	free(p);
581	}
582
583	static void
584	free_dns_response(struct dns_response *p)
585	{
586	if (p == NULL)
587	return;
588
589	free_dns_query(p->query);
590	free_dns_rr(p->answer);
591	free_dns_rr(p->authority);
592	free_dns_rr(p->additional);
593	free(p);
594	}
595
596	static int
597	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
598	{
599	int n = 0;
600
601	while(p) {
602	if (p->class == class && p->type == type)
603	n++;
604	p = p->next;
605	}
606
607	return (n);
608	}
609
540d72c3	610	#endif /* !defined(HAVE_GETRRSETBYNAME) */