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

/* $OpenBSD: getrrsetbyname.c,v 1.4 2001/08/16 18:16:43 ho 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 char *, int);
static struct dns_query *parse_dns_qsection(const char *, int, const char **,
    int);
static struct dns_rr *parse_dns_rrsection(const char *, int, const 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.
 */

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

	GETSHORT(u, msgp);
	return (u);
}

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

	GETLONG(u, msgp);
	return (u);
}

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;
	unsigned int length, index_ans, index_sig;
	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, rdclass, 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;

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

	/* 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 char *answer, int size)
{
	struct dns_response *resp;
	const 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 char *answer, int size, const 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 char *answer, int size, const 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 /* HAVE_GETRRSETBYNAME */
Commit	Line	Data
4460d509	1	/* $OpenBSD: getrrsetbyname.c,v 1.4 2001/08/16 18:16:43 ho Exp $ */
	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
	46	#include "includes.h"
	47
	48	#ifndef HAVE_GETRRSETBYNAME
	49
	50	#include "getrrsetbyname.h"
	51
	52	#define ANSWER_BUFFER_SIZE 1024*64
	53
	54	struct dns_query {
	55	char *name;
	56	u_int16_t type;
	57	u_int16_t class;
	58	struct dns_query *next;
	59	};
	60
	61	struct dns_rr {
	62	char *name;
	63	u_int16_t type;
	64	u_int16_t class;
65	u_int16_t ttl;
66	u_int16_t size;
67	void *rdata;
68	struct dns_rr *next;
69	};
70
71	struct dns_response {
72	HEADER header;
73	struct dns_query *query;
74	struct dns_rr *answer;
75	struct dns_rr *authority;
76	struct dns_rr *additional;
77	};
78
79	static struct dns_response parse_dns_response(const char , int);
80	static struct dns_query parse_dns_qsection(const char , int, const char **,
81	int);
82	static struct dns_rr parse_dns_rrsection(const char , int, const char **,
83	int);
84
85	static void free_dns_query(struct dns_query *);
86	static void free_dns_rr(struct dns_rr *);
87	static void free_dns_response(struct dns_response *);
88
89	static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
90
91	/*
92	* Inline versions of get/put short/long. Pointer is advanced.
93	*
94	* These macros demonstrate the property of C whereby it can be
95	* portable or it can be elegant but rarely both.
96	*/
97
98	#ifndef INT32SZ
99	# define INT32SZ 4
100	#endif
101	#ifndef INT16SZ
102	# define INT16SZ 2
103	#endif
104
105	#ifndef GETSHORT
106	#define GETSHORT(s, cp) { \
107	register u_char t_cp = (u_char )(cp); \
108	(s) = ((u_int16_t)t_cp[0] << 8) \
109	\| ((u_int16_t)t_cp[1]) \
110	; \
111	(cp) += INT16SZ; \
112	}
113	#endif
114
115	#ifndef GETLONG
116	#define GETLONG(l, cp) { \
117	register u_char t_cp = (u_char )(cp); \
118	(l) = ((u_int32_t)t_cp[0] << 24) \
119	\| ((u_int32_t)t_cp[1] << 16) \
120	\| ((u_int32_t)t_cp[2] << 8) \
121	\| ((u_int32_t)t_cp[3]) \
122	; \
123	(cp) += INT32SZ; \
124	}
125	#endif
126
127	/*
128	* Routines to insert/extract short/long's.
129	*/
130
131	static u_int16_t
132	_getshort(msgp)
133	register const u_char *msgp;
134	{
135	register u_int16_t u;
136
137	GETSHORT(u, msgp);
138	return (u);
139	}
140
141	static u_int32_t
142	_getlong(msgp)
143	register const u_char *msgp;
144	{
145	register u_int32_t u;
146
147	GETLONG(u, msgp);
148	return (u);
149	}
150
151	int
152	getrrsetbyname(const char *hostname, unsigned int rdclass,
153	unsigned int rdtype, unsigned int flags,
154	struct rrsetinfo **res)
155	{
156	int result;
157	struct rrsetinfo *rrset = NULL;
158	struct dns_response *response;
159	struct dns_rr *rr;
160	struct rdatainfo *rdata;
161	unsigned int length, index_ans, index_sig;
162	char answer[ANSWER_BUFFER_SIZE];
163
164	/* check for invalid class and type */
165	if (rdclass > 0xffff \|\| rdtype > 0xffff) {
166	result = ERRSET_INVAL;
167	goto fail;
168	}
169
170	/* don't allow queries of class or type ANY */
171	if (rdclass == 0xff \|\| rdtype == 0xff) {
172	result = ERRSET_INVAL;
173	goto fail;
174	}
175
176	/* don't allow flags yet, unimplemented */
177	if (flags) {
178	result = ERRSET_INVAL;
179	goto fail;
180	}
181
182	/* initialize resolver */
183	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
184	result = ERRSET_FAIL;
185	goto fail;
186	}
187
188	#ifdef DEBUG
189	_res.options \|= RES_DEBUG;
190	#endif /* DEBUG */
191
192	#ifdef RES_USE_DNSSEC
193	/* turn on DNSSEC if EDNS0 is configured */
194	if (_res.options & RES_USE_EDNS0)
195	_res.options \|= RES_USE_DNSSEC;
196	#endif /* RES_USE_DNSEC */
197
198	/* make query */
199	length = res_query(hostname, rdclass, rdtype, answer, sizeof(answer));
200	if (length < 0) {
201	switch(h_errno) {
202	case HOST_NOT_FOUND:
203	result = ERRSET_NONAME;
204	goto fail;
205	case NO_DATA:
206	result = ERRSET_NODATA;
207	goto fail;
208	default:
209	result = ERRSET_FAIL;
210	goto fail;
211	}
212	}
213
214	/* parse result */
215	response = parse_dns_response(answer, length);
216	if (response == NULL) {
217	result = ERRSET_FAIL;
218	goto fail;
219	}
220
221	if (response->header.qdcount != 1) {
222	result = ERRSET_FAIL;
223	goto fail;
224	}
225
226	/* initialize rrset */
227	rrset = calloc(1, sizeof(struct rrsetinfo));
228	if (rrset == NULL) {
229	result = ERRSET_NOMEMORY;
230	goto fail;
231	}
232	rrset->rri_rdclass = response->query->class;
233	rrset->rri_rdtype = response->query->type;
234	rrset->rri_ttl = response->answer->ttl;
235	rrset->rri_nrdatas = response->header.ancount;
236
237	/* check for authenticated data */
238	if (response->header.ad == 1)
239	rrset->rri_flags \|= RRSET_VALIDATED;
240
241	/* copy name from answer section */
242	length = strlen(response->answer->name);
243	rrset->rri_name = malloc(length + 1);
244	if (rrset->rri_name == NULL) {
245	result = ERRSET_NOMEMORY;
246	goto fail;
247	}
248	strlcpy(rrset->rri_name, response->answer->name, length + 1);
249
250	/* count answers */
251	rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
252	rrset->rri_rdtype);
253	rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
254	T_SIG);
255
256	/* allocate memory for answers */
257	rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
258	sizeof(struct rdatainfo));
259	if (rrset->rri_rdatas == NULL) {
260	result = ERRSET_NOMEMORY;
261	goto fail;
262	}
263
264	/* allocate memory for signatures */
265	rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
266	if (rrset->rri_sigs == NULL) {
267	result = ERRSET_NOMEMORY;
268	goto fail;
269	}
270
271	/* copy answers & signatures */
272	for (rr = response->answer, index_ans = 0, index_sig = 0;
273	rr; rr = rr->next) {
274
275	rdata = NULL;
276
277	if (rr->class == rrset->rri_rdclass &&
278	rr->type == rrset->rri_rdtype)
279	rdata = &rrset->rri_rdatas[index_ans++];
280
281	if (rr->class == rrset->rri_rdclass &&
282	rr->type == T_SIG)
283	rdata = &rrset->rri_sigs[index_sig++];
284
285	if (rdata) {
286	rdata->rdi_length = rr->size;
287	rdata->rdi_data = malloc(rr->size);
288
289	if (rdata->rdi_data == NULL) {
290	result = ERRSET_NOMEMORY;
291	goto fail;
292	}
293	memcpy(rdata->rdi_data, rr->rdata, rr->size);
294	}
295	}
296
297	*res = rrset;
298	return (ERRSET_SUCCESS);
299
300	fail:
301	if (rrset != NULL)
302	freerrset(rrset);
303	return (result);
304	}
305
306	void
307	freerrset(struct rrsetinfo *rrset)
308	{
309	u_int16_t i;
310
311	if (rrset == NULL)
312	return;
313
314	if (rrset->rri_rdatas) {
315	for (i = 0; i < rrset->rri_nrdatas; i++) {
316	if (rrset->rri_rdatas[i].rdi_data == NULL)
317	break;
318	free(rrset->rri_rdatas[i].rdi_data);
319	}
320	free(rrset->rri_rdatas);
321	}
322
323	if (rrset->rri_sigs) {
324	for (i = 0; i < rrset->rri_nsigs; i++) {
325	if (rrset->rri_sigs[i].rdi_data == NULL)
326	break;
327	free(rrset->rri_sigs[i].rdi_data);
328	}
329	free(rrset->rri_sigs);
330	}
331
332	if (rrset->rri_name)
333	free(rrset->rri_name);
334	free(rrset);
335	}
336
337	/*
338	* DNS response parsing routines
339	*/
340	static struct dns_response *
341	parse_dns_response(const char *answer, int size)
342	{
343	struct dns_response *resp;
344	const char *cp;
345
346	/* allocate memory for the response */
347	resp = calloc(1, sizeof(*resp));
348	if (resp == NULL)
349	return (NULL);
350
351	/* initialize current pointer */
352	cp = answer;
353
354	/* copy header */
355	memcpy(&resp->header, cp, HFIXEDSZ);
356	cp += HFIXEDSZ;
357
358	/* fix header byte order */
359	resp->header.qdcount = ntohs(resp->header.qdcount);
360	resp->header.ancount = ntohs(resp->header.ancount);
361	resp->header.nscount = ntohs(resp->header.nscount);
362	resp->header.arcount = ntohs(resp->header.arcount);
363
364	/* there must be at least one query */
365	if (resp->header.qdcount < 1) {
366	free_dns_response(resp);
367	return (NULL);
368	}
369
370	/* parse query section */
371	resp->query = parse_dns_qsection(answer, size, &cp,
372	resp->header.qdcount);
373	if (resp->header.qdcount && resp->query == NULL) {
374	free_dns_response(resp);
375	return (NULL);
376	}
377
378	/* parse answer section */
379	resp->answer = parse_dns_rrsection(answer, size, &cp,
380	resp->header.ancount);
381	if (resp->header.ancount && resp->answer == NULL) {
382	free_dns_response(resp);
383	return (NULL);
384	}
385
386	/* parse authority section */
387	resp->authority = parse_dns_rrsection(answer, size, &cp,
388	resp->header.nscount);
389	if (resp->header.nscount && resp->authority == NULL) {
390	free_dns_response(resp);
391	return (NULL);
392	}
393
394	/* parse additional section */
395	resp->additional = parse_dns_rrsection(answer, size, &cp,
396	resp->header.arcount);
397	if (resp->header.arcount && resp->additional == NULL) {
398	free_dns_response(resp);
399	return (NULL);
400	}
401
402	return (resp);
403	}
404
405	static struct dns_query *
406	parse_dns_qsection(const char answer, int size, const char *cp, int count)
407	{
408	struct dns_query head, curr, *prev;
409	int i, length;
410	char name[MAXDNAME];
411
412	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
413
414	/* allocate and initialize struct */
415	curr = calloc(1, sizeof(struct dns_query));
416	if (curr == NULL) {
417	free_dns_query(head);
418	return (NULL);
419	}
420	if (head == NULL)
421	head = curr;
422	if (prev != NULL)
423	prev->next = curr;
424
425	/* name */
426	length = dn_expand(answer, answer + size, *cp, name,
427	sizeof(name));
428	if (length < 0) {
429	free_dns_query(head);
430	return (NULL);
431	}
432	curr->name = strdup(name);
433	if (curr->name == NULL) {
434	free_dns_query(head);
435	return (NULL);
436	}
437	*cp += length;
438
439	/* type */
440	curr->type = _getshort(*cp);
441	*cp += INT16SZ;
442
443	/* class */
444	curr->class = _getshort(*cp);
445	*cp += INT16SZ;
446	}
447
448	return (head);
449	}
450
451	static struct dns_rr *
452	parse_dns_rrsection(const char answer, int size, const char *cp, int count)
453	{
454	struct dns_rr head, curr, *prev;
455	int i, length;
456	char name[MAXDNAME];
457
458	for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
459
460	/* allocate and initialize struct */
461	curr = calloc(1, sizeof(struct dns_rr));
462	if (curr == NULL) {
463	free_dns_rr(head);
464	return (NULL);
465	}
466	if (head == NULL)
467	head = curr;
468	if (prev != NULL)
469	prev->next = curr;
470
471	/* name */
472	length = dn_expand(answer, answer + size, *cp, name,
473	sizeof(name));
474	if (length < 0) {
475	free_dns_rr(head);
476	return (NULL);
477	}
478	curr->name = strdup(name);
479	if (curr->name == NULL) {
480	free_dns_rr(head);
481	return (NULL);
482	}
483	*cp += length;
484
485	/* type */
486	curr->type = _getshort(*cp);
487	*cp += INT16SZ;
488
489	/* class */
490	curr->class = _getshort(*cp);
491	*cp += INT16SZ;
492
493	/* ttl */
494	curr->ttl = _getlong(*cp);
495	*cp += INT32SZ;
496
497	/* rdata size */
498	curr->size = _getshort(*cp);
499	*cp += INT16SZ;
500
501	/* rdata itself */
502	curr->rdata = malloc(curr->size);
503	if (curr->rdata == NULL) {
504	free_dns_rr(head);
505	return (NULL);
506	}
507	memcpy(curr->rdata, *cp, curr->size);
508	*cp += curr->size;
509	}
510
511	return (head);
512	}
513
514	static void
515	free_dns_query(struct dns_query *p)
516	{
517	if (p == NULL)
518	return;
519
520	if (p->name)
521	free(p->name);
522	free_dns_query(p->next);
523	free(p);
524	}
525
526	static void
527	free_dns_rr(struct dns_rr *p)
528	{
529	if (p == NULL)
530	return;
531
532	if (p->name)
533	free(p->name);
534	if (p->rdata)
535	free(p->rdata);
536	free_dns_rr(p->next);
537	free(p);
538	}
539
540	static void
541	free_dns_response(struct dns_response *p)
542	{
543	if (p == NULL)
544	return;
545
546	free_dns_query(p->query);
547	free_dns_rr(p->answer);
548	free_dns_rr(p->authority);
549	free_dns_rr(p->additional);
550	free(p);
551	}
552
553	static int
554	count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type)
555	{
556	int n = 0;
557
558	while(p) {
559	if (p->class == class && p->type == type)
560	n++;
561	p = p->next;
562	}
563
564	return (n);
565	}
566
567	#endif /* HAVE_GETRRSETBYNAME */