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b43b13ac | 1 | /* |
cd5743fd | 2 | * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
b43b13ac UD |
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 | * | |
cd5743fd UD |
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. | |
b43b13ac UD |
16 | */ |
17 | ||
b43b13ac UD |
18 | /* Import. */ |
19 | ||
20 | #include <sys/types.h> | |
21 | ||
22 | #include <netinet/in.h> | |
23 | #include <arpa/nameser.h> | |
24 | ||
25 | #include <errno.h> | |
26 | #include <resolv.h> | |
27 | #include <string.h> | |
28 | ||
29 | /* Forward. */ | |
30 | ||
31 | static void setsection(ns_msg *msg, ns_sect sect); | |
32 | ||
33 | /* Macros. */ | |
34 | ||
35 | #define RETERR(err) do { __set_errno (err); return (-1); } while (0) | |
36 | ||
37 | /* Public. */ | |
38 | ||
39 | /* These need to be in the same order as the nres.h:ns_flag enum. */ | |
cd5743fd UD |
40 | const struct _ns_flagdata _ns_flagdata[16] = { |
41 | { 0x8000, 15 }, /*%< qr. */ | |
42 | { 0x7800, 11 }, /*%< opcode. */ | |
43 | { 0x0400, 10 }, /*%< aa. */ | |
44 | { 0x0200, 9 }, /*%< tc. */ | |
45 | { 0x0100, 8 }, /*%< rd. */ | |
46 | { 0x0080, 7 }, /*%< ra. */ | |
47 | { 0x0040, 6 }, /*%< z. */ | |
48 | { 0x0020, 5 }, /*%< ad. */ | |
49 | { 0x0010, 4 }, /*%< cd. */ | |
50 | { 0x000f, 0 }, /*%< rcode. */ | |
51 | { 0x0000, 0 }, /*%< expansion (1/6). */ | |
52 | { 0x0000, 0 }, /*%< expansion (2/6). */ | |
53 | { 0x0000, 0 }, /*%< expansion (3/6). */ | |
54 | { 0x0000, 0 }, /*%< expansion (4/6). */ | |
55 | { 0x0000, 0 }, /*%< expansion (5/6). */ | |
56 | { 0x0000, 0 }, /*%< expansion (6/6). */ | |
b43b13ac UD |
57 | }; |
58 | ||
cd5743fd UD |
59 | #undef ns_msg_getflag |
60 | int ns_msg_getflag(ns_msg handle, int flag) { | |
61 | return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); | |
62 | } | |
63 | ||
b43b13ac UD |
64 | int |
65 | ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { | |
66 | const u_char *optr = ptr; | |
67 | ||
68 | for ((void)NULL; count > 0; count--) { | |
69 | int b, rdlength; | |
70 | ||
71 | b = dn_skipname(ptr, eom); | |
72 | if (b < 0) | |
73 | RETERR(EMSGSIZE); | |
74 | ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; | |
75 | if (section != ns_s_qd) { | |
76 | if (ptr + NS_INT32SZ + NS_INT16SZ > eom) | |
77 | RETERR(EMSGSIZE); | |
78 | ptr += NS_INT32SZ/*TTL*/; | |
79 | NS_GET16(rdlength, ptr); | |
80 | ptr += rdlength/*RData*/; | |
81 | } | |
82 | } | |
83 | if (ptr > eom) | |
84 | RETERR(EMSGSIZE); | |
85 | return (ptr - optr); | |
86 | } | |
cd5743fd | 87 | libresolv_hidden_def (ns_skiprr) |
b43b13ac UD |
88 | |
89 | int | |
90 | ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { | |
91 | const u_char *eom = msg + msglen; | |
92 | int i; | |
93 | ||
94 | memset(handle, 0x5e, sizeof *handle); | |
95 | handle->_msg = msg; | |
96 | handle->_eom = eom; | |
97 | if (msg + NS_INT16SZ > eom) | |
98 | RETERR(EMSGSIZE); | |
99 | NS_GET16(handle->_id, msg); | |
100 | if (msg + NS_INT16SZ > eom) | |
101 | RETERR(EMSGSIZE); | |
102 | NS_GET16(handle->_flags, msg); | |
103 | for (i = 0; i < ns_s_max; i++) { | |
104 | if (msg + NS_INT16SZ > eom) | |
105 | RETERR(EMSGSIZE); | |
106 | NS_GET16(handle->_counts[i], msg); | |
107 | } | |
108 | for (i = 0; i < ns_s_max; i++) | |
109 | if (handle->_counts[i] == 0) | |
110 | handle->_sections[i] = NULL; | |
111 | else { | |
112 | int b = ns_skiprr(msg, eom, (ns_sect)i, | |
113 | handle->_counts[i]); | |
114 | ||
115 | if (b < 0) | |
116 | return (-1); | |
117 | handle->_sections[i] = msg; | |
118 | msg += b; | |
119 | } | |
120 | if (msg != eom) | |
121 | RETERR(EMSGSIZE); | |
122 | setsection(handle, ns_s_max); | |
123 | return (0); | |
124 | } | |
cd5743fd | 125 | libresolv_hidden_def (ns_initparse) |
b43b13ac UD |
126 | |
127 | int | |
128 | ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { | |
129 | int b; | |
cd5743fd | 130 | int tmp; |
b43b13ac UD |
131 | |
132 | /* Make section right. */ | |
cd5743fd UD |
133 | tmp = section; |
134 | if (tmp < 0 || section >= ns_s_max) | |
b43b13ac UD |
135 | RETERR(ENODEV); |
136 | if (section != handle->_sect) | |
137 | setsection(handle, section); | |
138 | ||
139 | /* Make rrnum right. */ | |
140 | if (rrnum == -1) | |
141 | rrnum = handle->_rrnum; | |
142 | if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) | |
143 | RETERR(ENODEV); | |
144 | if (rrnum < handle->_rrnum) | |
145 | setsection(handle, section); | |
146 | if (rrnum > handle->_rrnum) { | |
cd5743fd | 147 | b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, |
b43b13ac UD |
148 | rrnum - handle->_rrnum); |
149 | ||
150 | if (b < 0) | |
151 | return (-1); | |
cd5743fd | 152 | handle->_msg_ptr += b; |
b43b13ac UD |
153 | handle->_rrnum = rrnum; |
154 | } | |
155 | ||
156 | /* Do the parse. */ | |
157 | b = dn_expand(handle->_msg, handle->_eom, | |
cd5743fd | 158 | handle->_msg_ptr, rr->name, NS_MAXDNAME); |
b43b13ac UD |
159 | if (b < 0) |
160 | return (-1); | |
cd5743fd UD |
161 | handle->_msg_ptr += b; |
162 | if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) | |
b43b13ac | 163 | RETERR(EMSGSIZE); |
cd5743fd UD |
164 | NS_GET16(rr->type, handle->_msg_ptr); |
165 | NS_GET16(rr->rr_class, handle->_msg_ptr); | |
b43b13ac UD |
166 | if (section == ns_s_qd) { |
167 | rr->ttl = 0; | |
168 | rr->rdlength = 0; | |
169 | rr->rdata = NULL; | |
170 | } else { | |
cd5743fd | 171 | if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) |
b43b13ac | 172 | RETERR(EMSGSIZE); |
cd5743fd UD |
173 | NS_GET32(rr->ttl, handle->_msg_ptr); |
174 | NS_GET16(rr->rdlength, handle->_msg_ptr); | |
175 | if (handle->_msg_ptr + rr->rdlength > handle->_eom) | |
b43b13ac | 176 | RETERR(EMSGSIZE); |
cd5743fd UD |
177 | rr->rdata = handle->_msg_ptr; |
178 | handle->_msg_ptr += rr->rdlength; | |
b43b13ac UD |
179 | } |
180 | if (++handle->_rrnum > handle->_counts[(int)section]) | |
181 | setsection(handle, (ns_sect)((int)section + 1)); | |
182 | ||
183 | /* All done. */ | |
184 | return (0); | |
185 | } | |
cd5743fd | 186 | libresolv_hidden_def (ns_parserr) |
b43b13ac UD |
187 | |
188 | /* Private. */ | |
189 | ||
190 | static void | |
191 | setsection(ns_msg *msg, ns_sect sect) { | |
192 | msg->_sect = sect; | |
193 | if (sect == ns_s_max) { | |
194 | msg->_rrnum = -1; | |
cd5743fd | 195 | msg->_msg_ptr = NULL; |
b43b13ac UD |
196 | } else { |
197 | msg->_rrnum = 0; | |
cd5743fd | 198 | msg->_msg_ptr = msg->_sections[(int)sect]; |
b43b13ac UD |
199 | } |
200 | } | |
cd5743fd UD |
201 | |
202 | /*! \file */ |