2 * SPDX-License-Identifier: ISC
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1996,1999 by Internet Software Consortium.
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 static const char rcsid[] = "$Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp $";
23 #include <sys/cdefs.h>
26 #include "port_before.h"
28 #include <sys/types.h>
30 #include <netinet/in.h>
31 #include <arpa/nameser.h>
37 #include "port_after.h"
41 static void setsection(ns_msg *msg, ns_sect sect);
45 #if !defined(SOLARIS2) || defined(__COVERITY__)
46 #define RETERR(err) do { errno = (err); return (-1); } while (0)
49 do { errno = (err); if (errno == errno) return (-1); } while (0)
52 #define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */
53 #define PARSE_FMT_WIRE 1 /* Parse using network-format names */
57 /* These need to be in the same order as the nres.h:ns_flag enum. */
58 struct _ns_flagdata _ns_flagdata[16] = {
59 { 0x8000, 15 }, /*%< qr. */
60 { 0x7800, 11 }, /*%< opcode. */
61 { 0x0400, 10 }, /*%< aa. */
62 { 0x0200, 9 }, /*%< tc. */
63 { 0x0100, 8 }, /*%< rd. */
64 { 0x0080, 7 }, /*%< ra. */
65 { 0x0040, 6 }, /*%< z. */
66 { 0x0020, 5 }, /*%< ad. */
67 { 0x0010, 4 }, /*%< cd. */
68 { 0x000f, 0 }, /*%< rcode. */
69 { 0x0000, 0 }, /*%< expansion (1/6). */
70 { 0x0000, 0 }, /*%< expansion (2/6). */
71 { 0x0000, 0 }, /*%< expansion (3/6). */
72 { 0x0000, 0 }, /*%< expansion (4/6). */
73 { 0x0000, 0 }, /*%< expansion (5/6). */
74 { 0x0000, 0 }, /*%< expansion (6/6). */
77 int ns_msg_getflag(ns_msg handle, int flag) {
78 return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
82 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
83 const u_char *optr = ptr;
85 for ((void)NULL; count > 0; count--) {
88 b = dn_skipname(ptr, eom);
91 ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
92 if (section != ns_s_qd) {
93 if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
95 ptr += NS_INT32SZ/*TTL*/;
96 NS_GET16(rdlength, ptr);
97 ptr += rdlength/*RData*/;
106 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
107 const u_char *eom = msg + msglen;
112 if (msg + NS_INT16SZ > eom)
114 NS_GET16(handle->_id, msg);
115 if (msg + NS_INT16SZ > eom)
117 NS_GET16(handle->_flags, msg);
118 for (i = 0; i < ns_s_max; i++) {
119 if (msg + NS_INT16SZ > eom)
121 NS_GET16(handle->_counts[i], msg);
123 for (i = 0; i < ns_s_max; i++)
124 if (handle->_counts[i] == 0)
125 handle->_sections[i] = NULL;
127 int b = ns_skiprr(msg, eom, (ns_sect)i,
132 handle->_sections[i] = msg;
137 setsection(handle, ns_s_max);
142 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
146 /* Make section right. */
148 if (tmp < 0 || section >= ns_s_max)
150 if (section != handle->_sect)
151 setsection(handle, section);
153 /* Make rrnum right. */
155 rrnum = handle->_rrnum;
156 if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
158 if (rrnum < handle->_rrnum)
159 setsection(handle, section);
160 if (rrnum > handle->_rrnum) {
161 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
162 rrnum - handle->_rrnum);
166 handle->_msg_ptr += b;
167 handle->_rrnum = rrnum;
171 b = dn_expand(handle->_msg, handle->_eom,
172 handle->_msg_ptr, rr->name, NS_MAXDNAME);
175 handle->_msg_ptr += b;
176 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
178 NS_GET16(rr->type, handle->_msg_ptr);
179 NS_GET16(rr->rr_class, handle->_msg_ptr);
180 if (section == ns_s_qd) {
185 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
187 NS_GET32(rr->ttl, handle->_msg_ptr);
188 NS_GET16(rr->rdlength, handle->_msg_ptr);
189 if (handle->_msg_ptr + rr->rdlength > handle->_eom)
191 rr->rdata = handle->_msg_ptr;
192 handle->_msg_ptr += rr->rdlength;
194 if (++handle->_rrnum > handle->_counts[(int)section])
195 setsection(handle, (ns_sect)((int)section + 1));
202 * This is identical to the above but uses network-format (uncompressed) names.
205 ns_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) {
209 /* Make section right. */
210 if ((tmp = section) < 0 || section >= ns_s_max)
212 if (section != handle->_sect)
213 setsection(handle, section);
215 /* Make rrnum right. */
217 rrnum = handle->_rrnum;
218 if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
220 if (rrnum < handle->_rrnum)
221 setsection(handle, section);
222 if (rrnum > handle->_rrnum) {
223 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
224 rrnum - handle->_rrnum);
228 handle->_msg_ptr += b;
229 handle->_rrnum = rrnum;
233 b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr,
234 rr->nname, NS_MAXNNAME, &rr->nnamel);
237 handle->_msg_ptr += b;
238 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
240 NS_GET16(rr->type, handle->_msg_ptr);
241 NS_GET16(rr->rr_class, handle->_msg_ptr);
242 if (section == ns_s_qd) {
247 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
249 NS_GET32(rr->ttl, handle->_msg_ptr);
250 NS_GET16(rr->rdlength, handle->_msg_ptr);
251 if (handle->_msg_ptr + rr->rdlength > handle->_eom)
253 rr->rdata = handle->_msg_ptr;
254 handle->_msg_ptr += rr->rdlength;
256 if (++handle->_rrnum > handle->_counts[(int)section])
257 setsection(handle, (ns_sect)((int)section + 1));
266 setsection(ns_msg *msg, ns_sect sect) {
268 if (sect == ns_s_max) {
270 msg->_msg_ptr = NULL;
273 msg->_msg_ptr = msg->_sections[(int)sect];