2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996,1999 by Internet Software Consortium.
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 * $Id: ns_parse.c,v 1.9 2007/08/27 03:32:26 marka Exp $
22 #include "port_before.h"
24 #include <sys/types.h>
26 #include <netinet/in.h>
27 #include <arpa/nameser.h>
33 #include "port_after.h"
37 static void setsection(ns_msg *msg, ns_sect sect);
41 #if !defined(SOLARIS2) || defined(__COVERITY__)
42 #define RETERR(err) do { errno = (err); return (-1); } while (0)
45 do { errno = (err); if (errno == errno) return (-1); } while (0)
50 /* These need to be in the same order as the nres.h:ns_flag enum. */
51 struct _ns_flagdata _ns_flagdata[16] = {
52 { 0x8000, 15 }, /*%< qr. */
53 { 0x7800, 11 }, /*%< opcode. */
54 { 0x0400, 10 }, /*%< aa. */
55 { 0x0200, 9 }, /*%< tc. */
56 { 0x0100, 8 }, /*%< rd. */
57 { 0x0080, 7 }, /*%< ra. */
58 { 0x0040, 6 }, /*%< z. */
59 { 0x0020, 5 }, /*%< ad. */
60 { 0x0010, 4 }, /*%< cd. */
61 { 0x000f, 0 }, /*%< rcode. */
62 { 0x0000, 0 }, /*%< expansion (1/6). */
63 { 0x0000, 0 }, /*%< expansion (2/6). */
64 { 0x0000, 0 }, /*%< expansion (3/6). */
65 { 0x0000, 0 }, /*%< expansion (4/6). */
66 { 0x0000, 0 }, /*%< expansion (5/6). */
67 { 0x0000, 0 }, /*%< expansion (6/6). */
70 int ns_msg_getflag(ns_msg handle, int flag) {
71 return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
75 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
76 const u_char *optr = ptr;
78 for ((void)NULL; count > 0; count--) {
81 b = dn_skipname(ptr, eom);
84 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
85 if (section != ns_s_qd) {
86 if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
88 ptr += NS_INT32SZ/*TTL*/;
89 NS_GET16(rdlength, ptr);
90 ptr += rdlength/*RData*/;
99 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
100 const u_char *eom = msg + msglen;
103 memset(handle, 0x5e, sizeof *handle);
106 if (msg + NS_INT16SZ > eom)
108 NS_GET16(handle->_id, msg);
109 if (msg + NS_INT16SZ > eom)
111 NS_GET16(handle->_flags, msg);
112 for (i = 0; i < ns_s_max; i++) {
113 if (msg + NS_INT16SZ > eom)
115 NS_GET16(handle->_counts[i], msg);
117 for (i = 0; i < ns_s_max; i++)
118 if (handle->_counts[i] == 0)
119 handle->_sections[i] = NULL;
121 int b = ns_skiprr(msg, eom, (ns_sect)i,
126 handle->_sections[i] = msg;
131 setsection(handle, ns_s_max);
136 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
140 /* Make section right. */
142 if (tmp < 0 || section >= ns_s_max)
144 if (section != handle->_sect)
145 setsection(handle, section);
147 /* Make rrnum right. */
149 rrnum = handle->_rrnum;
150 if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
152 if (rrnum < handle->_rrnum)
153 setsection(handle, section);
154 if (rrnum > handle->_rrnum) {
155 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
156 rrnum - handle->_rrnum);
160 handle->_msg_ptr += b;
161 handle->_rrnum = rrnum;
165 b = dn_expand(handle->_msg, handle->_eom,
166 handle->_msg_ptr, rr->name, NS_MAXDNAME);
169 handle->_msg_ptr += b;
170 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
172 NS_GET16(rr->type, handle->_msg_ptr);
173 NS_GET16(rr->rr_class, handle->_msg_ptr);
174 if (section == ns_s_qd) {
179 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
181 NS_GET32(rr->ttl, handle->_msg_ptr);
182 NS_GET16(rr->rdlength, handle->_msg_ptr);
183 if (handle->_msg_ptr + rr->rdlength > handle->_eom)
185 rr->rdata = handle->_msg_ptr;
186 handle->_msg_ptr += rr->rdlength;
188 if (++handle->_rrnum > handle->_counts[(int)section])
189 setsection(handle, (ns_sect)((int)section + 1));
198 setsection(ns_msg *msg, ns_sect sect) {
200 if (sect == ns_s_max) {
202 msg->_msg_ptr = NULL;
205 msg->_msg_ptr = msg->_sections[(int)sect];