[gssapi-openssh.git] / openssh / 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 <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)

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

struct __res_state _res;

/* Necessary functions and macros */

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

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

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

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

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

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

	GETSHORT(u, msgp);
	return (u);
}
#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
u_int16_t _getshort(register const u_char *);
#endif

#ifndef HAVE__GETLONG
static u_int32_t
_getlong(msgp)
	register const u_char *msgp;
{
	register u_int32_t u;

	GETLONG(u, msgp);
	return (u);
}
#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
u_int32_t _getlong(register const u_char *);
#endif

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

#define ANSWER_BUFFER_SIZE 1024*64

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

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

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

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

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

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

int
getrrsetbyname(const char *hostname, unsigned int rdclass,
    unsigned int rdtype, unsigned int flags,
    struct rrsetinfo **res)
{
	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
	int result;
	struct rrsetinfo *rrset = NULL;
	struct dns_response *response = NULL;
	struct dns_rr *rr;
	struct rdatainfo *rdata;
	int length;
	unsigned int index_ans, index_sig;
	u_char answer[ANSWER_BUFFER_SIZE];

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

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

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

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

#ifdef DEBUG
	_resp->options |= RES_DEBUG;
#endif /* DEBUG */

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

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

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

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

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

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

	/* copy name from answer section */
	rrset->rri_name = strdup(response->answer->name);
	if (rrset->rri_name == NULL) {
		result = ERRSET_NOMEMORY;
		goto fail;
	}

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

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

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

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

		rdata = NULL;

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

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

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

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

	*res = rrset;
	return (ERRSET_SUCCESS);

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

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

	if (rrset == NULL)
		return;

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

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

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

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

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

	/* initialize current pointer */
	cp = answer;

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

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

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

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

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

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

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

	return (resp);
}

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

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

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

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

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

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

	return (head);
}

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

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

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

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

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

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

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

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

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

	return (head);
}

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

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

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

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

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

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

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

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

	return (n);
}

#endif /* !defined(HAVE_GETRRSETBYNAME) */
Commit	Line	Data
08822d99	1	/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu 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
	70	/* to avoid conflicts where a platform already has _res */
	71	#ifdef _res
	72	# undef _res
	73	#endif
	74	#define _res _compat_res
	75
08822d99	76	struct __res_state _res;
c9307018	77
08822d99	78	/* Necessary functions and macros */
c9307018	79
	80	/*
	81	* Inline versions of get/put short/long. Pointer is advanced.
	82	*
	83	* These macros demonstrate the property of C whereby it can be
	84	* portable or it can be elegant but rarely both.
	85	*/
	86
	87	#ifndef INT32SZ
	88	# define INT32SZ 4
	89	#endif
	90	#ifndef INT16SZ
	91	# define INT16SZ 2
	92	#endif
	93
	94	#ifndef GETSHORT
	95	#define GETSHORT(s, cp) { \
	96	register u_char t_cp = (u_char )(cp); \
	97	(s) = ((u_int16_t)t_cp[0] << 8) \
	98	\| ((u_int16_t)t_cp[1]) \
	99	; \
	100	(cp) += INT16SZ; \
	101	}
	102	#endif
	103
	104	#ifndef GETLONG
	105	#define GETLONG(l, cp) { \
	106	register u_char t_cp = (u_char )(cp); \
	107	(l) = ((u_int32_t)t_cp[0] << 24) \
	108	\| ((u_int32_t)t_cp[1] << 16) \
	109	\| ((u_int32_t)t_cp[2] << 8) \
	110	\| ((u_int32_t)t_cp[3]) \
	111	; \
	112	(cp) += INT32SZ; \
	113	}
	114	#endif
	115
	116	/*
	117	* Routines to insert/extract short/long's.
	118	*/
	119
	120	#ifndef HAVE__GETSHORT
	121	static u_int16_t
	122	_getshort(msgp)
	123	register const u_char *msgp;
	124	{
	125	register u_int16_t u;
	126
	127	GETSHORT(u, msgp);
	128	return (u);
	129	}
2ce0bfe4	130	#elif defined(HAVE_DECL__GETSHORT) && (HAVE_DECL__GETSHORT == 0)
2ce0bfe4	131	u_int16_t _getshort(register const u_char *);
c9307018	132	#endif
	133
	134	#ifndef HAVE__GETLONG
	135	static u_int32_t
	136	_getlong(msgp)
	137	register const u_char *msgp;
	138	{
	139	register u_int32_t u;
	140
	141	GETLONG(u, msgp);
	142	return (u);
	143	}
2ce0bfe4	144	#elif defined(HAVE_DECL__GETLONG) && (HAVE_DECL__GETLONG == 0)
2ce0bfe4	145	u_int32_t _getlong(register const u_char *);
c9307018	146	#endif
c9307018	147
08822d99	148	/* ************** */
	149
	150	#define ANSWER_BUFFER_SIZE 1024*64
	151
	152	struct dns_query {
	153	char *name;
	154	u_int16_t type;
	155	u_int16_t class;
	156	struct dns_query *next;
	157	};
	158
	159	struct dns_rr {
	160	char *name;
	161	u_int16_t type;
	162	u_int16_t class;
	163	u_int16_t ttl;
	164	u_int16_t size;
	165	void *rdata;
	166	struct dns_rr *next;
	167	};
	168
	169	struct dns_response {
	170	HEADER header;
	171	struct dns_query *query;
	172	struct dns_rr *answer;
	173	struct dns_rr *authority;
	174	struct dns_rr *additional;
	175	};
	176
	177	static struct dns_response parse_dns_response(const u_char , int);
	178	static struct dns_query parse_dns_qsection(const u_char , int,
	179	const u_char **, int);
	180	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
	181	int);
	182
	183	static void free_dns_query(struct dns_query *);
	184	static void free_dns_rr(struct dns_rr *);
	185	static void free_dns_response(struct dns_response *);
	186
	187	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	188
c9307018	189	int
	190	getrrsetbyname(const char *hostname, unsigned int rdclass,
	191	unsigned int rdtype, unsigned int flags,
	192	struct rrsetinfo **res)
	193	{
08822d99	194	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
c9307018	195	int result;
c9307018	196	struct rrsetinfo *rrset = NULL;
08822d99	197	struct dns_response *response = NULL;
c9307018	198	struct dns_rr *rr;
	199	struct rdatainfo *rdata;
	200	int length;
	201	unsigned int index_ans, index_sig;
	202	u_char answer[ANSWER_BUFFER_SIZE];
	203
	204	/* check for invalid class and type */
	205	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
	206	result = ERRSET_INVAL;
	207	goto fail;
	208	}
	209
	210	/* don't allow queries of class or type ANY */
	211	if (rdclass == 0xff \|\| rdtype == 0xff) {
	212	result = ERRSET_INVAL;
	213	goto fail;
	214	}
	215
	216	/* don't allow flags yet, unimplemented */
	217	if (flags) {
	218	result = ERRSET_INVAL;
	219	goto fail;
	220	}
	221
	222	/* initialize resolver */
08822d99	223	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
c9307018	224	result = ERRSET_FAIL;
	225	goto fail;
	226	}
	227
	228	#ifdef DEBUG
08822d99	229	_resp->options \|= RES_DEBUG;
c9307018	230	#endif /* DEBUG */
	231
	232	#ifdef RES_USE_DNSSEC
	233	/* turn on DNSSEC if EDNS0 is configured */
08822d99	234	if (_resp->options & RES_USE_EDNS0)
08822d99	235	_resp->options \|= RES_USE_DNSSEC;
c9307018	236	#endif /* RES_USE_DNSEC */
	237
	238	/* make query */
	239	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
	240	answer, sizeof(answer));
	241	if (length < 0) {
	242	switch(h_errno) {
	243	case HOST_NOT_FOUND:
	244	result = ERRSET_NONAME;
	245	goto fail;
	246	case NO_DATA:
	247	result = ERRSET_NODATA;
	248	goto fail;
	249	default:
	250	result = ERRSET_FAIL;
	251	goto fail;
	252	}
	253	}
	254
	255	/* parse result */
	256	response = parse_dns_response(answer, length);
	257	if (response == NULL) {
	258	result = ERRSET_FAIL;
	259	goto fail;
	260	}
	261
	262	if (response->header.qdcount != 1) {
	263	result = ERRSET_FAIL;
	264	goto fail;
	265	}
	266
	267	/* initialize rrset */
	268	rrset = calloc(1, sizeof(struct rrsetinfo));
	269	if (rrset == NULL) {
	270	result = ERRSET_NOMEMORY;
	271	goto fail;
	272	}
	273	rrset->rri_rdclass = response->query->class;
	274	rrset->rri_rdtype = response->query->type;
	275	rrset->rri_ttl = response->answer->ttl;
	276	rrset->rri_nrdatas = response->header.ancount;
	277
	278	#ifdef HAVE_HEADER_AD
	279	/* check for authenticated data */
	280	if (response->header.ad == 1)
	281	rrset->rri_flags \|= RRSET_VALIDATED;
	282	#endif
	283
	284	/* copy name from answer section */
08822d99	285	rrset->rri_name = strdup(response->answer->name);
c9307018	286	if (rrset->rri_name == NULL) {
	287	result = ERRSET_NOMEMORY;
	288	goto fail;
	289	}
c9307018	290
	291	/* count answers */
	292	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
	293	rrset->rri_rdtype);
	294	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
	295	T_SIG);
	296
	297	/* allocate memory for answers */
	298	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
	299	sizeof(struct rdatainfo));
	300	if (rrset->rri_rdatas == NULL) {
	301	result = ERRSET_NOMEMORY;
	302	goto fail;
	303	}
	304
	305	/* allocate memory for signatures */
	306	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
08822d99	307	if (rrset->rri_sigs == NULL) {
c9307018	308	result = ERRSET_NOMEMORY;
	309	goto fail;
	310	}
	311
	312	/* copy answers & signatures */
	313	for (rr = response->answer, index_ans = 0, index_sig = 0;
	314	rr; rr = rr->next) {
	315
	316	rdata = NULL;
	317
	318	if (rr->class == rrset->rri_rdclass &&
	319	rr->type == rrset->rri_rdtype)
	320	rdata = &rrset->rri_rdatas[index_ans++];
	321
	322	if (rr->class == rrset->rri_rdclass &&
	323	rr->type == T_SIG)
	324	rdata = &rrset->rri_sigs[index_sig++];
	325
	326	if (rdata) {
	327	rdata->rdi_length = rr->size;
	328	rdata->rdi_data = malloc(rr->size);
	329
	330	if (rdata->rdi_data == NULL) {
	331	result = ERRSET_NOMEMORY;
	332	goto fail;
	333	}
	334	memcpy(rdata->rdi_data, rr->rdata, rr->size);
	335	}
	336	}
08822d99	337	free_dns_response(response);
c9307018	338
	339	*res = rrset;
	340	return (ERRSET_SUCCESS);
	341
	342	fail:
	343	if (rrset != NULL)
	344	freerrset(rrset);
08822d99	345	if (response != NULL)
08822d99	346	free_dns_response(response);
c9307018	347	return (result);
	348	}
	349
	350	void
	351	freerrset(struct rrsetinfo *rrset)
	352	{
	353	u_int16_t i;
	354
	355	if (rrset == NULL)
	356	return;
	357
	358	if (rrset->rri_rdatas) {
	359	for (i = 0; i < rrset->rri_nrdatas; i++) {
	360	if (rrset->rri_rdatas[i].rdi_data == NULL)
	361	break;
	362	free(rrset->rri_rdatas[i].rdi_data);
	363	}
	364	free(rrset->rri_rdatas);
	365	}
	366
	367	if (rrset->rri_sigs) {
	368	for (i = 0; i < rrset->rri_nsigs; i++) {
	369	if (rrset->rri_sigs[i].rdi_data == NULL)
	370	break;
	371	free(rrset->rri_sigs[i].rdi_data);
	372	}
	373	free(rrset->rri_sigs);
	374	}
	375
	376	if (rrset->rri_name)
	377	free(rrset->rri_name);
	378	free(rrset);
	379	}
	380
	381	/*
	382	* DNS response parsing routines
	383	*/
	384	static struct dns_response *
	385	parse_dns_response(const u_char *answer, int size)
	386	{
	387	struct dns_response *resp;
	388	const u_char *cp;
	389
	390	/* allocate memory for the response */
	391	resp = calloc(1, sizeof(*resp));
	392	if (resp == NULL)
	393	return (NULL);
	394
	395	/* initialize current pointer */
	396	cp = answer;
	397
	398	/* copy header */
	399	memcpy(&resp->header, cp, HFIXEDSZ);
	400	cp += HFIXEDSZ;
	401
	402	/* fix header byte order */
	403	resp->header.qdcount = ntohs(resp->header.qdcount);
	404	resp->header.ancount = ntohs(resp->header.ancount);
	405	resp->header.nscount = ntohs(resp->header.nscount);
	406	resp->header.arcount = ntohs(resp->header.arcount);
	407
	408	/* there must be at least one query */
	409	if (resp->header.qdcount < 1) {
	410	free_dns_response(resp);
411	return (NULL);
412	}
413
414	/* parse query section */
415	resp->query = parse_dns_qsection(answer, size, &cp,
416	resp->header.qdcount);
417	if (resp->header.qdcount && resp->query == NULL) {
418	free_dns_response(resp);
419	return (NULL);
420	}
421
422	/* parse answer section */
423	resp->answer = parse_dns_rrsection(answer, size, &cp,
424	resp->header.ancount);
425	if (resp->header.ancount && resp->answer == NULL) {
426	free_dns_response(resp);
427	return (NULL);
428	}
429
430	/* parse authority section */
431	resp->authority = parse_dns_rrsection(answer, size, &cp,
432	resp->header.nscount);
433	if (resp->header.nscount && resp->authority == NULL) {
434	free_dns_response(resp);
435	return (NULL);
436	}
437
438	/* parse additional section */
439	resp->additional = parse_dns_rrsection(answer, size, &cp,
440	resp->header.arcount);
441	if (resp->header.arcount && resp->additional == NULL) {
442	free_dns_response(resp);
443	return (NULL);
444	}
445
446	return (resp);
447	}
448
449	static struct dns_query *
450	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
451	{
452	struct dns_query head, curr, *prev;
453	int i, length;
454	char name[MAXDNAME];
455
456	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
457
458	/* allocate and initialize struct */
459	curr = calloc(1, sizeof(struct dns_query));
460	if (curr == NULL) {
461	free_dns_query(head);
462	return (NULL);
463	}
464	if (head == NULL)
465	head = curr;
466	if (prev != NULL)
467	prev->next = curr;
468
469	/* name */
470	length = dn_expand(answer, answer + size, *cp, name,
471	sizeof(name));
472	if (length < 0) {
473	free_dns_query(head);
474	return (NULL);
475	}
476	curr->name = strdup(name);
477	if (curr->name == NULL) {
478	free_dns_query(head);
479	return (NULL);
480	}
481	*cp += length;
482
483	/* type */
484	curr->type = _getshort(*cp);
485	*cp += INT16SZ;
486
487	/* class */
488	curr->class = _getshort(*cp);
489	*cp += INT16SZ;
490	}
491
492	return (head);
493	}
494
495	static struct dns_rr *
08822d99	496	parse_dns_rrsection(const u_char answer, int size, const u_char *cp,
08822d99	497	int count)
c9307018	498	{
	499	struct dns_rr head, curr, *prev;
	500	int i, length;
	501	char name[MAXDNAME];
	502
	503	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
	504
	505	/* allocate and initialize struct */
	506	curr = calloc(1, sizeof(struct dns_rr));
	507	if (curr == NULL) {
	508	free_dns_rr(head);
	509	return (NULL);
	510	}
	511	if (head == NULL)
	512	head = curr;
	513	if (prev != NULL)
	514	prev->next = curr;
	515
	516	/* name */
	517	length = dn_expand(answer, answer + size, *cp, name,
	518	sizeof(name));
	519	if (length < 0) {
	520	free_dns_rr(head);
	521	return (NULL);
	522	}
	523	curr->name = strdup(name);
	524	if (curr->name == NULL) {
	525	free_dns_rr(head);
	526	return (NULL);
	527	}
	528	*cp += length;
	529
	530	/* type */
	531	curr->type = _getshort(*cp);
	532	*cp += INT16SZ;
	533
	534	/* class */
	535	curr->class = _getshort(*cp);
	536	*cp += INT16SZ;
	537
	538	/* ttl */
	539	curr->ttl = _getlong(*cp);
	540	*cp += INT32SZ;
	541
	542	/* rdata size */
	543	curr->size = _getshort(*cp);
	544	*cp += INT16SZ;
	545
	546	/* rdata itself */
	547	curr->rdata = malloc(curr->size);
	548	if (curr->rdata == NULL) {
	549	free_dns_rr(head);
	550	return (NULL);
	551	}
	552	memcpy(curr->rdata, *cp, curr->size);
	553	*cp += curr->size;
	554	}
	555
	556	return (head);
	557	}
	558
	559	static void
	560	free_dns_query(struct dns_query *p)
	561	{
562	if (p == NULL)
563	return;
564
565	if (p->name)
566	free(p->name);
567	free_dns_query(p->next);
568	free(p);
569	}
570
571	static void
572	free_dns_rr(struct dns_rr *p)
573	{
574	if (p == NULL)
575	return;
576
577	if (p->name)
578	free(p->name);
579	if (p->rdata)
580	free(p->rdata);
581	free_dns_rr(p->next);
582	free(p);
583	}
584
585	static void
586	free_dns_response(struct dns_response *p)
587	{
588	if (p == NULL)
589	return;
590
591	free_dns_query(p->query);
592	free_dns_rr(p->answer);
593	free_dns_rr(p->authority);
594	free_dns_rr(p->additional);
595	free(p);
596	}
597
598	static int
599	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
600	{
601	int n = 0;
602
603	while(p) {
604	if (p->class == class && p->type == type)
605	n++;
606	p = p->next;
607	}
608
609	return (n);
610	}
611
540d72c3	612	#endif /* !defined(HAVE_GETRRSETBYNAME) */