1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996,1999 by Internet Software Consortium.
4 *
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.
8 *
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.
16 */
17
18 #include "bitlbee.h"
19
20 #ifndef lint
21 //static const char rcsid[] = "$Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp $";
22 #endif
23
24 #ifdef HAVE_RESOLV_A
25 #ifndef HAVE_RESOLV_A_WITH_NS
26 /* Import. */
27
28
29 #include <sys/types.h>
30
31 #include <netinet/in.h>
32 #include <arpa/nameser.h>
33
34 #include <errno.h>
35 #include <resolv.h>
36 #include <string.h>
37
38
39 /* Forward. */
40
41 static void setsection(ns_msg *msg, ns_sect sect);
42
43 /* Macros. */
44
45 #if !defined(SOLARIS2) || defined(__COVERITY__)
46 #define RETERR(err) do { errno = (err); return (-1); } while (0)
47 #else
48 #define RETERR(err) \
49 do { errno = (err); if (errno == errno) { return (-1); } } while (0)
50 #endif
51
52 #define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */
53 #define PARSE_FMT_WIRE 1 /* Parse using network-format names */
54
55 /* Public. */
56
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). */
75 };
76
ns_msg_getflag(ns_msg handle,int flag)77 int ns_msg_getflag(ns_msg handle, int flag)
78 {
79 return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
80 }
81
82 int
ns_skiprr(const u_char * ptr,const u_char * eom,ns_sect section,int count)83 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count)
84 {
85 const u_char *optr = ptr;
86
87 for ((void) NULL; count > 0; count--) {
88 int b, rdlength;
89
90 b = dn_skipname(ptr, eom);
91 if (b < 0) {
92 RETERR(EMSGSIZE);
93 }
94 ptr += b /*Name*/ + NS_INT16SZ /*Type*/ + NS_INT16SZ /*Class*/;
95 if (section != ns_s_qd) {
96 if (ptr + NS_INT32SZ + NS_INT16SZ > eom) {
97 RETERR(EMSGSIZE);
98 }
99 ptr += NS_INT32SZ /*TTL*/;
100 NS_GET16(rdlength, ptr);
101 ptr += rdlength /*RData*/;
102 }
103 }
104 if (ptr > eom) {
105 RETERR(EMSGSIZE);
106 }
107 return (ptr - optr);
108 }
109
110 int
ns_initparse(const u_char * msg,int msglen,ns_msg * handle)111 ns_initparse(const u_char *msg, int msglen, ns_msg *handle)
112 {
113 const u_char *eom = msg + msglen;
114 int i;
115
116 handle->_msg = msg;
117 handle->_eom = eom;
118 if (msg + NS_INT16SZ > eom) {
119 RETERR(EMSGSIZE);
120 }
121 NS_GET16(handle->_id, msg);
122 if (msg + NS_INT16SZ > eom) {
123 RETERR(EMSGSIZE);
124 }
125 NS_GET16(handle->_flags, msg);
126 for (i = 0; i < ns_s_max; i++) {
127 if (msg + NS_INT16SZ > eom) {
128 RETERR(EMSGSIZE);
129 }
130 NS_GET16(handle->_counts[i], msg);
131 }
132 for (i = 0; i < ns_s_max; i++) {
133 if (handle->_counts[i] == 0) {
134 handle->_sections[i] = NULL;
135 } else {
136 int b = ns_skiprr(msg, eom, (ns_sect) i,
137 handle->_counts[i]);
138
139 if (b < 0) {
140 return (-1);
141 }
142 handle->_sections[i] = msg;
143 msg += b;
144 }
145 }
146 if (msg != eom) {
147 RETERR(EMSGSIZE);
148 }
149 setsection(handle, ns_s_max);
150 return (0);
151 }
152
153 int
ns_parserr(ns_msg * handle,ns_sect section,int rrnum,ns_rr * rr)154 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr)
155 {
156 int b;
157 int tmp;
158
159 /* Make section right. */
160 tmp = section;
161 if (tmp < 0 || section >= ns_s_max) {
162 RETERR(ENODEV);
163 }
164 if (section != handle->_sect) {
165 setsection(handle, section);
166 }
167
168 /* Make rrnum right. */
169 if (rrnum == -1) {
170 rrnum = handle->_rrnum;
171 }
172 if (rrnum < 0 || rrnum >= handle->_counts[(int) section]) {
173 RETERR(ENODEV);
174 }
175 if (rrnum < handle->_rrnum) {
176 setsection(handle, section);
177 }
178 if (rrnum > handle->_rrnum) {
179 b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
180 rrnum - handle->_rrnum);
181
182 if (b < 0) {
183 return (-1);
184 }
185 handle->_msg_ptr += b;
186 handle->_rrnum = rrnum;
187 }
188
189 /* Do the parse. */
190 b = dn_expand(handle->_msg, handle->_eom,
191 handle->_msg_ptr, rr->name, NS_MAXDNAME);
192 if (b < 0) {
193 return (-1);
194 }
195 handle->_msg_ptr += b;
196 if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) {
197 RETERR(EMSGSIZE);
198 }
199 NS_GET16(rr->type, handle->_msg_ptr);
200 NS_GET16(rr->rr_class, handle->_msg_ptr);
201 if (section == ns_s_qd) {
202 rr->ttl = 0;
203 rr->rdlength = 0;
204 rr->rdata = NULL;
205 } else {
206 if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) {
207 RETERR(EMSGSIZE);
208 }
209 NS_GET32(rr->ttl, handle->_msg_ptr);
210 NS_GET16(rr->rdlength, handle->_msg_ptr);
211 if (handle->_msg_ptr + rr->rdlength > handle->_eom) {
212 RETERR(EMSGSIZE);
213 }
214 rr->rdata = handle->_msg_ptr;
215 handle->_msg_ptr += rr->rdlength;
216 }
217 if (++handle->_rrnum > handle->_counts[(int) section]) {
218 setsection(handle, (ns_sect) ((int) section + 1));
219 }
220
221 /* All done. */
222 return (0);
223 }
224
225 /* Private. */
226
227 static void
setsection(ns_msg * msg,ns_sect sect)228 setsection(ns_msg *msg, ns_sect sect)
229 {
230 msg->_sect = sect;
231 if (sect == ns_s_max) {
232 msg->_rrnum = -1;
233 msg->_msg_ptr = NULL;
234 } else {
235 msg->_rrnum = 0;
236 msg->_msg_ptr = msg->_sections[(int) sect];
237 }
238 }
239
240 /*! \file */
241 #endif
242 #endif
243