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0ac16a4492
_getlong in #ifndef
577 lines
13 KiB
C
577 lines
13 KiB
C
/* $OpenBSD: getrrsetbyname.c,v 1.7 2003/03/07 07:34:14 itojun Exp $ */
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/*
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* Copyright (c) 2001 Jakob Schlyter. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Portions Copyright (c) 1999-2001 Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
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* DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
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* INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
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* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
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* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "includes.h"
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#if defined(DNS) && !defined(HAVE_GETRRSETBYNAME)
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#include "getrrsetbyname.h"
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/* #include "thread_private.h" */
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#define ANSWER_BUFFER_SIZE 1024*64
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struct dns_query {
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char *name;
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u_int16_t type;
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u_int16_t class;
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struct dns_query *next;
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};
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struct dns_rr {
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char *name;
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u_int16_t type;
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u_int16_t class;
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u_int16_t ttl;
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u_int16_t size;
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void *rdata;
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struct dns_rr *next;
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};
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struct dns_response {
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HEADER header;
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struct dns_query *query;
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struct dns_rr *answer;
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struct dns_rr *authority;
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struct dns_rr *additional;
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};
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static struct dns_response *parse_dns_response(const u_char *, int);
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static struct dns_query *parse_dns_qsection(const u_char *, int,
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const u_char **, int);
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static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **,
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int);
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static void free_dns_query(struct dns_query *);
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static void free_dns_rr(struct dns_rr *);
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static void free_dns_response(struct dns_response *);
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static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t);
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/*
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* Inline versions of get/put short/long. Pointer is advanced.
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*
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* These macros demonstrate the property of C whereby it can be
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* portable or it can be elegant but rarely both.
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*/
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#ifndef INT32SZ
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# define INT32SZ 4
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#endif
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#ifndef INT16SZ
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# define INT16SZ 2
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#endif
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#ifndef GETSHORT
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#define GETSHORT(s, cp) { \
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register u_char *t_cp = (u_char *)(cp); \
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(s) = ((u_int16_t)t_cp[0] << 8) \
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| ((u_int16_t)t_cp[1]) \
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; \
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(cp) += INT16SZ; \
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}
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#endif
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#ifndef GETLONG
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#define GETLONG(l, cp) { \
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register u_char *t_cp = (u_char *)(cp); \
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(l) = ((u_int32_t)t_cp[0] << 24) \
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| ((u_int32_t)t_cp[1] << 16) \
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| ((u_int32_t)t_cp[2] << 8) \
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| ((u_int32_t)t_cp[3]) \
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; \
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(cp) += INT32SZ; \
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}
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#endif
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/*
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* Routines to insert/extract short/long's.
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*/
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#ifndef HAVE__GETSHORT
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static u_int16_t
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_getshort(msgp)
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register const u_char *msgp;
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{
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register u_int16_t u;
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GETSHORT(u, msgp);
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return (u);
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}
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#endif
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#ifndef HAVE__GETLONG
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static u_int32_t
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_getlong(msgp)
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register const u_char *msgp;
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{
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register u_int32_t u;
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GETLONG(u, msgp);
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return (u);
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}
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#endif
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int
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getrrsetbyname(const char *hostname, unsigned int rdclass,
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unsigned int rdtype, unsigned int flags,
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struct rrsetinfo **res)
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{
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struct __res_state *_resp = &_res;
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int result;
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struct rrsetinfo *rrset = NULL;
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struct dns_response *response;
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struct dns_rr *rr;
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struct rdatainfo *rdata;
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int length;
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unsigned int index_ans, index_sig;
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u_char answer[ANSWER_BUFFER_SIZE];
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/* check for invalid class and type */
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if (rdclass > 0xffff || rdtype > 0xffff) {
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result = ERRSET_INVAL;
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goto fail;
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}
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/* don't allow queries of class or type ANY */
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if (rdclass == 0xff || rdtype == 0xff) {
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result = ERRSET_INVAL;
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goto fail;
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}
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/* don't allow flags yet, unimplemented */
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if (flags) {
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result = ERRSET_INVAL;
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goto fail;
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}
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/* initialize resolver */
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if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
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result = ERRSET_FAIL;
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goto fail;
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}
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#ifdef DEBUG
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_resp->options |= RES_DEBUG;
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#endif /* DEBUG */
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#ifdef RES_USE_DNSSEC
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/* turn on DNSSEC if EDNS0 is configured */
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if (_resp->options & RES_USE_EDNS0)
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_resp->options |= RES_USE_DNSSEC;
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#endif /* RES_USE_DNSEC */
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/* make query */
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length = res_query(hostname, (signed int) rdclass, (signed int) rdtype,
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answer, sizeof(answer));
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if (length < 0) {
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switch(h_errno) {
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case HOST_NOT_FOUND:
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result = ERRSET_NONAME;
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goto fail;
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case NO_DATA:
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result = ERRSET_NODATA;
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goto fail;
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default:
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result = ERRSET_FAIL;
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goto fail;
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}
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}
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/* parse result */
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response = parse_dns_response(answer, length);
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if (response == NULL) {
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result = ERRSET_FAIL;
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goto fail;
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}
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if (response->header.qdcount != 1) {
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result = ERRSET_FAIL;
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goto fail;
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}
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/* initialize rrset */
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rrset = calloc(1, sizeof(struct rrsetinfo));
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if (rrset == NULL) {
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result = ERRSET_NOMEMORY;
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goto fail;
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}
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rrset->rri_rdclass = response->query->class;
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rrset->rri_rdtype = response->query->type;
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rrset->rri_ttl = response->answer->ttl;
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rrset->rri_nrdatas = response->header.ancount;
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/* check for authenticated data */
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if (response->header.ad == 1)
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rrset->rri_flags |= RRSET_VALIDATED;
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/* copy name from answer section */
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length = strlen(response->answer->name);
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rrset->rri_name = malloc(length + 1);
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if (rrset->rri_name == NULL) {
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result = ERRSET_NOMEMORY;
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goto fail;
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}
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strlcpy(rrset->rri_name, response->answer->name, length + 1);
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/* count answers */
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rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass,
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rrset->rri_rdtype);
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rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass,
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T_SIG);
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/* allocate memory for answers */
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rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
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sizeof(struct rdatainfo));
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if (rrset->rri_rdatas == NULL) {
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result = ERRSET_NOMEMORY;
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goto fail;
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}
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/* allocate memory for signatures */
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rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo));
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if (rrset->rri_sigs == NULL) {
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result = ERRSET_NOMEMORY;
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goto fail;
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}
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/* copy answers & signatures */
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for (rr = response->answer, index_ans = 0, index_sig = 0;
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rr; rr = rr->next) {
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rdata = NULL;
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if (rr->class == rrset->rri_rdclass &&
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rr->type == rrset->rri_rdtype)
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rdata = &rrset->rri_rdatas[index_ans++];
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if (rr->class == rrset->rri_rdclass &&
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rr->type == T_SIG)
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rdata = &rrset->rri_sigs[index_sig++];
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if (rdata) {
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rdata->rdi_length = rr->size;
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rdata->rdi_data = malloc(rr->size);
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if (rdata->rdi_data == NULL) {
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result = ERRSET_NOMEMORY;
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goto fail;
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}
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memcpy(rdata->rdi_data, rr->rdata, rr->size);
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}
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}
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*res = rrset;
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return (ERRSET_SUCCESS);
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fail:
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if (rrset != NULL)
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freerrset(rrset);
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return (result);
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}
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void
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freerrset(struct rrsetinfo *rrset)
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{
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u_int16_t i;
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if (rrset == NULL)
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return;
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if (rrset->rri_rdatas) {
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for (i = 0; i < rrset->rri_nrdatas; i++) {
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if (rrset->rri_rdatas[i].rdi_data == NULL)
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break;
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free(rrset->rri_rdatas[i].rdi_data);
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}
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free(rrset->rri_rdatas);
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}
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if (rrset->rri_sigs) {
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for (i = 0; i < rrset->rri_nsigs; i++) {
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if (rrset->rri_sigs[i].rdi_data == NULL)
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break;
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free(rrset->rri_sigs[i].rdi_data);
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}
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free(rrset->rri_sigs);
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}
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if (rrset->rri_name)
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free(rrset->rri_name);
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free(rrset);
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}
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/*
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* DNS response parsing routines
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*/
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static struct dns_response *
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parse_dns_response(const u_char *answer, int size)
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{
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struct dns_response *resp;
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const u_char *cp;
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/* allocate memory for the response */
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resp = calloc(1, sizeof(*resp));
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if (resp == NULL)
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return (NULL);
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/* initialize current pointer */
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cp = answer;
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/* copy header */
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memcpy(&resp->header, cp, HFIXEDSZ);
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cp += HFIXEDSZ;
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/* fix header byte order */
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resp->header.qdcount = ntohs(resp->header.qdcount);
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resp->header.ancount = ntohs(resp->header.ancount);
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resp->header.nscount = ntohs(resp->header.nscount);
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resp->header.arcount = ntohs(resp->header.arcount);
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/* there must be at least one query */
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if (resp->header.qdcount < 1) {
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free_dns_response(resp);
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return (NULL);
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}
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/* parse query section */
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resp->query = parse_dns_qsection(answer, size, &cp,
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resp->header.qdcount);
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if (resp->header.qdcount && resp->query == NULL) {
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free_dns_response(resp);
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return (NULL);
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}
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/* parse answer section */
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resp->answer = parse_dns_rrsection(answer, size, &cp,
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resp->header.ancount);
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if (resp->header.ancount && resp->answer == NULL) {
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free_dns_response(resp);
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return (NULL);
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}
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/* parse authority section */
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resp->authority = parse_dns_rrsection(answer, size, &cp,
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resp->header.nscount);
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if (resp->header.nscount && resp->authority == NULL) {
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free_dns_response(resp);
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return (NULL);
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}
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/* parse additional section */
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resp->additional = parse_dns_rrsection(answer, size, &cp,
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resp->header.arcount);
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if (resp->header.arcount && resp->additional == NULL) {
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free_dns_response(resp);
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return (NULL);
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}
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return (resp);
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}
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static struct dns_query *
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parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count)
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{
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struct dns_query *head, *curr, *prev;
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int i, length;
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char name[MAXDNAME];
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for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
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/* allocate and initialize struct */
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curr = calloc(1, sizeof(struct dns_query));
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if (curr == NULL) {
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free_dns_query(head);
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return (NULL);
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}
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if (head == NULL)
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head = curr;
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if (prev != NULL)
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prev->next = curr;
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/* name */
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length = dn_expand(answer, answer + size, *cp, name,
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sizeof(name));
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if (length < 0) {
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free_dns_query(head);
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return (NULL);
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}
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curr->name = strdup(name);
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if (curr->name == NULL) {
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free_dns_query(head);
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return (NULL);
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}
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*cp += length;
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/* type */
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curr->type = _getshort(*cp);
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*cp += INT16SZ;
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/* class */
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curr->class = _getshort(*cp);
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*cp += INT16SZ;
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}
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return (head);
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}
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static struct dns_rr *
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parse_dns_rrsection(const u_char *answer, int size, const u_char **cp, int count)
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{
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struct dns_rr *head, *curr, *prev;
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int i, length;
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char name[MAXDNAME];
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for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) {
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/* allocate and initialize struct */
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curr = calloc(1, sizeof(struct dns_rr));
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if (curr == NULL) {
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free_dns_rr(head);
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return (NULL);
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}
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if (head == NULL)
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head = curr;
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if (prev != NULL)
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prev->next = curr;
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/* name */
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length = dn_expand(answer, answer + size, *cp, name,
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sizeof(name));
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if (length < 0) {
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free_dns_rr(head);
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return (NULL);
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}
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curr->name = strdup(name);
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if (curr->name == NULL) {
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free_dns_rr(head);
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return (NULL);
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}
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*cp += length;
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/* type */
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curr->type = _getshort(*cp);
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*cp += INT16SZ;
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/* class */
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curr->class = _getshort(*cp);
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*cp += INT16SZ;
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/* ttl */
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curr->ttl = _getlong(*cp);
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*cp += INT32SZ;
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/* rdata size */
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curr->size = _getshort(*cp);
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*cp += INT16SZ;
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/* rdata itself */
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curr->rdata = malloc(curr->size);
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if (curr->rdata == NULL) {
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free_dns_rr(head);
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return (NULL);
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}
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memcpy(curr->rdata, *cp, curr->size);
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*cp += curr->size;
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}
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return (head);
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}
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static void
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free_dns_query(struct dns_query *p)
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{
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if (p == NULL)
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return;
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if (p->name)
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free(p->name);
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free_dns_query(p->next);
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free(p);
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}
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static void
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free_dns_rr(struct dns_rr *p)
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{
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if (p == NULL)
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return;
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if (p->name)
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free(p->name);
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if (p->rdata)
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free(p->rdata);
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free_dns_rr(p->next);
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free(p);
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}
|
|
|
|
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(DNS) && !defined(HAVE_GETRRSETBYNAME) */
|