[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"

/* #include "thread_private.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)
{
	struct __res_state *_resp = &_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 ((_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 */
	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
12408a1b	1	/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */
12408a1b	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
12408a1b	50	#ifndef HAVE_GETRRSETBYNAME
0fff78ff	51
	52	#include "getrrsetbyname.h"
	53
	54	/* #include "thread_private.h" */
	55
	56	#define ANSWER_BUFFER_SIZE 1024*64
	57
	58	struct dns_query {
	59	char *name;
	60	u_int16_t type;
	61	u_int16_t class;
	62	struct dns_query *next;
	63	};
	64
	65	struct dns_rr {
	66	char *name;
	67	u_int16_t type;
	68	u_int16_t class;
	69	u_int16_t ttl;
	70	u_int16_t size;
	71	void *rdata;
	72	struct dns_rr *next;
	73	};
	74
	75	struct dns_response {
	76	HEADER header;
	77	struct dns_query *query;
	78	struct dns_rr *answer;
	79	struct dns_rr *authority;
	80	struct dns_rr *additional;
	81	};
	82
	83	static struct dns_response parse_dns_response(const u_char , int);
	84	static struct dns_query parse_dns_qsection(const u_char , int,
	85	const u_char **, int);
	86	static struct dns_rr parse_dns_rrsection(const u_char , int, const u_char **,
	87	int);
	88
	89	static void free_dns_query(struct dns_query *);
	90	static void free_dns_rr(struct dns_rr *);
	91	static void free_dns_response(struct dns_response *);
	92
	93	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
	94
	95	/*
	96	* Inline versions of get/put short/long. Pointer is advanced.
	97	*
	98	* These macros demonstrate the property of C whereby it can be
	99	* portable or it can be elegant but rarely both.
	100	*/
	101
	102	#ifndef INT32SZ
	103	# define INT32SZ 4
	104	#endif
	105	#ifndef INT16SZ
	106	# define INT16SZ 2
	107	#endif
	108
	109	#ifndef GETSHORT
	110	#define GETSHORT(s, cp) { \
	111	register u_char t_cp = (u_char )(cp); \
	112	(s) = ((u_int16_t)t_cp[0] << 8) \
	113	\| ((u_int16_t)t_cp[1]) \
	114	; \
115	(cp) += INT16SZ; \
116	}
117	#endif
118
119	#ifndef GETLONG
120	#define GETLONG(l, cp) { \
121	register u_char t_cp = (u_char )(cp); \
122	(l) = ((u_int32_t)t_cp[0] << 24) \
123	\| ((u_int32_t)t_cp[1] << 16) \
124	\| ((u_int32_t)t_cp[2] << 8) \
125	\| ((u_int32_t)t_cp[3]) \
126	; \
127	(cp) += INT32SZ; \
128	}
129	#endif
130
131	/*
132	* Routines to insert/extract short/long's.
133	*/
134
135	#ifndef HAVE__GETSHORT
136	static u_int16_t
137	_getshort(msgp)
138	register const u_char *msgp;
139	{
140	register u_int16_t u;
141
142	GETSHORT(u, msgp);
143	return (u);
144	}
145	#endif
146
147	#ifndef HAVE__GETLONG
148	static u_int32_t
149	_getlong(msgp)
150	register const u_char *msgp;
151	{
152	register u_int32_t u;
153
154	GETLONG(u, msgp);
155	return (u);
156	}
157	#endif
158
159	int
160	getrrsetbyname(const char *hostname, unsigned int rdclass,
161	unsigned int rdtype, unsigned int flags,
162	struct rrsetinfo **res)
163	{
164	struct __res_state *_resp = &_res;
165	int result;
166	struct rrsetinfo *rrset = NULL;
167	struct dns_response *response;
168	struct dns_rr *rr;
169	struct rdatainfo *rdata;
170	int length;
171	unsigned int index_ans, index_sig;
172	u_char answer[ANSWER_BUFFER_SIZE];
173
174	/* check for invalid class and type */
175	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
176	result = ERRSET_INVAL;
177	goto fail;
178	}
179
180	/* don't allow queries of class or type ANY */
181	if (rdclass == 0xff \|\| rdtype == 0xff) {
182	result = ERRSET_INVAL;
183	goto fail;
184	}
185
186	/* don't allow flags yet, unimplemented */
187	if (flags) {
188	result = ERRSET_INVAL;
189	goto fail;
190	}
191
192	/* initialize resolver */
193	if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
194	result = ERRSET_FAIL;
195	goto fail;
196	}
197
198	#ifdef DEBUG
199	_resp->options \|= RES_DEBUG;
200	#endif /* DEBUG */
201
202	#ifdef RES_USE_DNSSEC
203	/* turn on DNSSEC if EDNS0 is configured */
204	if (_resp->options & RES_USE_EDNS0)
205	_resp->options \|= RES_USE_DNSSEC;
206	#endif /* RES_USE_DNSEC */
207
208	/* make query */
209	length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
210	answer, sizeof(answer));
211	if (length < 0) {
212	switch(h_errno) {
213	case HOST_NOT_FOUND:
214	result = ERRSET_NONAME;
215	goto fail;
216	case NO_DATA:
217	result = ERRSET_NODATA;
218	goto fail;
219	default:
220	result = ERRSET_FAIL;
221	goto fail;
222	}
223	}
224
225	/* parse result */
226	response = parse_dns_response(answer, length);
227	if (response == NULL) {
228	result = ERRSET_FAIL;
229	goto fail;
230	}
231
232	if (response->header.qdcount != 1) {
233	result = ERRSET_FAIL;
234	goto fail;
235	}
236
237	/* initialize rrset */
238	rrset = calloc(1, sizeof(struct rrsetinfo));
239	if (rrset == NULL) {
240	result = ERRSET_NOMEMORY;
241	goto fail;
242	}
243	rrset->rri_rdclass = response->query->class;
244	rrset->rri_rdtype = response->query->type;
245	rrset->rri_ttl = response->answer->ttl;
246	rrset->rri_nrdatas = response->header.ancount;
247
248	#ifdef HAVE_HEADER_AD
249	/* check for authenticated data */
250	if (response->header.ad == 1)
251	rrset->rri_flags \|= RRSET_VALIDATED;
252	#endif
253
254	/* copy name from answer section */
255	length = strlen(response->answer->name);
256	rrset->rri_name = malloc(length + 1);
257	if (rrset->rri_name == NULL) {
258	result = ERRSET_NOMEMORY;
259	goto fail;
260	}
261	strlcpy(rrset->rri_name, response->answer->name, length + 1);
262
263	/* count answers */
264	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
265	rrset->rri_rdtype);
266	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
267	T_SIG);
268
269	/* allocate memory for answers */
270	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
271	sizeof(struct rdatainfo));
272	if (rrset->rri_rdatas == NULL) {
273	result = ERRSET_NOMEMORY;
274	goto fail;
275	}
276
277	/* allocate memory for signatures */
278	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
279	if (rrset->rri_sigs == NULL) {
280	result = ERRSET_NOMEMORY;
281	goto fail;
282	}
283
284	/* copy answers & signatures */
285	for (rr = response->answer, index_ans = 0, index_sig = 0;
286	rr; rr = rr->next) {
287
288	rdata = NULL;
289
290	if (rr->class == rrset->rri_rdclass &&
291	rr->type == rrset->rri_rdtype)
292	rdata = &rrset->rri_rdatas[index_ans++];
293
294	if (rr->class == rrset->rri_rdclass &&
295	rr->type == T_SIG)
296	rdata = &rrset->rri_sigs[index_sig++];
297
298	if (rdata) {
299	rdata->rdi_length = rr->size;
300	rdata->rdi_data = malloc(rr->size);
301
302	if (rdata->rdi_data == NULL) {
303	result = ERRSET_NOMEMORY;
304	goto fail;
305	}
306	memcpy(rdata->rdi_data, rr->rdata, rr->size);
307	}
308	}
309
310	*res = rrset;
311	return (ERRSET_SUCCESS);
312
313	fail:
314	if (rrset != NULL)
315	freerrset(rrset);
316	return (result);
317	}
318
319	void
320	freerrset(struct rrsetinfo *rrset)
321	{
322	u_int16_t i;
323
324	if (rrset == NULL)
325	return;
326
327	if (rrset->rri_rdatas) {
328	for (i = 0; i < rrset->rri_nrdatas; i++) {
329	if (rrset->rri_rdatas[i].rdi_data == NULL)
330	break;
331	free(rrset->rri_rdatas[i].rdi_data);
332	}
333	free(rrset->rri_rdatas);
334	}
335
336	if (rrset->rri_sigs) {
337	for (i = 0; i < rrset->rri_nsigs; i++) {
338	if (rrset->rri_sigs[i].rdi_data == NULL)
339	break;
340	free(rrset->rri_sigs[i].rdi_data);
341	}
342	free(rrset->rri_sigs);
343	}
344
345	if (rrset->rri_name)
346	free(rrset->rri_name);
347	free(rrset);
348	}
349
350	/*
351	* DNS response parsing routines
352	*/
353	static struct dns_response *
354	parse_dns_response(const u_char *answer, int size)
355	{
356	struct dns_response *resp;
357	const u_char *cp;
358
359	/* allocate memory for the response */
360	resp = calloc(1, sizeof(*resp));
361	if (resp == NULL)
362	return (NULL);
363
364	/* initialize current pointer */
365	cp = answer;
366
367	/* copy header */
368	memcpy(&resp->header, cp, HFIXEDSZ);
369	cp += HFIXEDSZ;
370
371	/* fix header byte order */
372	resp->header.qdcount = ntohs(resp->header.qdcount);
373	resp->header.ancount = ntohs(resp->header.ancount);
374	resp->header.nscount = ntohs(resp->header.nscount);
375	resp->header.arcount = ntohs(resp->header.arcount);
376
377	/* there must be at least one query */
378	if (resp->header.qdcount < 1) {
379	free_dns_response(resp);
380	return (NULL);
381	}
382
383	/* parse query section */
384	resp->query = parse_dns_qsection(answer, size, &cp,
385	resp->header.qdcount);
386	if (resp->header.qdcount && resp->query == NULL) {
387	free_dns_response(resp);
388	return (NULL);
389	}
390
391	/* parse answer section */
392	resp->answer = parse_dns_rrsection(answer, size, &cp,
393	resp->header.ancount);
394	if (resp->header.ancount && resp->answer == NULL) {
395	free_dns_response(resp);
396	return (NULL);
397	}
398
399	/* parse authority section */
400	resp->authority = parse_dns_rrsection(answer, size, &cp,
401	resp->header.nscount);
402	if (resp->header.nscount && resp->authority == NULL) {
403	free_dns_response(resp);
404	return (NULL);
405	}
406
407	/* parse additional section */
408	resp->additional = parse_dns_rrsection(answer, size, &cp,
409	resp->header.arcount);
410	if (resp->header.arcount && resp->additional == NULL) {
411	free_dns_response(resp);
412	return (NULL);
413	}
414
415	return (resp);
416	}
417
418	static struct dns_query *
419	parse_dns_qsection(const u_char answer, int size, const u_char *cp, int count)
420	{
421	struct dns_query head, curr, *prev;
422	int i, length;
423	char name[MAXDNAME];
424
425	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
426
427	/* allocate and initialize struct */
428	curr = calloc(1, sizeof(struct dns_query));
429	if (curr == NULL) {
430	free_dns_query(head);
431	return (NULL);
432	}
433	if (head == NULL)
434	head = curr;
435	if (prev != NULL)
436	prev->next = curr;
437
438	/* name */
439	length = dn_expand(answer, answer + size, *cp, name,
440	sizeof(name));
441	if (length < 0) {
442	free_dns_query(head);
443	return (NULL);
444	}
445	curr->name = strdup(name);
446	if (curr->name == NULL) {
447	free_dns_query(head);
448	return (NULL);
449	}
450	*cp += length;
451
452	/* type */
453	curr->type = _getshort(*cp);
454	*cp += INT16SZ;
455
456	/* class */
457	curr->class = _getshort(*cp);
458	*cp += INT16SZ;
459	}
460
461	return (head);
462	}
463
464	static struct dns_rr *
465	parse_dns_rrsection(const u_char answer, int size, const u_char *cp, int count)
466	{
467	struct dns_rr head, curr, *prev;
468	int i, length;
469	char name[MAXDNAME];
470
471	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
472
473	/* allocate and initialize struct */
474	curr = calloc(1, sizeof(struct dns_rr));
475	if (curr == NULL) {
476	free_dns_rr(head);
477	return (NULL);
478	}
479	if (head == NULL)
480	head = curr;
481	if (prev != NULL)
482	prev->next = curr;
483
484	/* name */
485	length = dn_expand(answer, answer + size, *cp, name,
486	sizeof(name));
487	if (length < 0) {
488	free_dns_rr(head);
489	return (NULL);
490	}
491	curr->name = strdup(name);
492	if (curr->name == NULL) {
493	free_dns_rr(head);
494	return (NULL);
495	}
496	*cp += length;
497
498	/* type */
499	curr->type = _getshort(*cp);
500	*cp += INT16SZ;
501
502	/* class */
503	curr->class = _getshort(*cp);
504	*cp += INT16SZ;
505
506	/* ttl */
507	curr->ttl = _getlong(*cp);
508	*cp += INT32SZ;
509
510	/* rdata size */
511	curr->size = _getshort(*cp);
512	*cp += INT16SZ;
513
514	/* rdata itself */
515	curr->rdata = malloc(curr->size);
516	if (curr->rdata == NULL) {
517	free_dns_rr(head);
518	return (NULL);
519	}
520	memcpy(curr->rdata, *cp, curr->size);
521	*cp += curr->size;
522	}
523
524	return (head);
525	}
526
527	static void
528	free_dns_query(struct dns_query *p)
529	{
530	if (p == NULL)
531	return;
532
533	if (p->name)
534	free(p->name);
535	free_dns_query(p->next);
536	free(p);
537	}
538
539	static void
540	free_dns_rr(struct dns_rr *p)
541	{
542	if (p == NULL)
543	return;
544
545	if (p->name)
546	free(p->name);
547	if (p->rdata)
548	free(p->rdata);
549	free_dns_rr(p->next);
550	free(p);
551	}
552
553	static void
554	free_dns_response(struct dns_response *p)
555	{
556	if (p == NULL)
557	return;
558
559	free_dns_query(p->query);
560	free_dns_rr(p->answer);
561	free_dns_rr(p->authority);
562	free_dns_rr(p->additional);
563	free(p);
564	}
565
566	static int
567	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
568	{
569	int n = 0;
570
571	while(p) {
572	if (p->class == class && p->type == type)
573	n++;
574	p = p->next;
575	}
576
577	return (n);
578	}
579
12408a1b	580	#endif /* !defined(HAVE_GETRRSETBYNAME) */