1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/*
* Copyright (c) 1985, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
/*
* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv/resolv-internal.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
/* Options. Leave them on. */
/* #define DEBUG */
#include <hp-timing.h>
#include <stdint.h>
#if HP_TIMING_AVAIL
# define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
#endif
/*
* Form all types of queries.
* Returns the size of the result or -1.
*/
int
res_nmkquery(res_state statp,
int op, /* opcode of query */
const char *dname, /* domain name */
int class, int type, /* class and type of query */
const u_char *data, /* resource record data */
int datalen, /* length of data */
const u_char *newrr_in, /* new rr for modify or append */
u_char *buf, /* buffer to put query */
int buflen) /* size of buffer */
{
HEADER *hp;
u_char *cp;
int n;
u_char *dnptrs[20], **dpp, **lastdnptr;
if (class < 0 || class > 65535
|| type < 0 || type > 65535)
return -1;
#ifdef DEBUG
if (statp->options & RES_DEBUG)
printf(";; res_nmkquery(%s, %s, %s, %s)\n",
_res_opcodes[op], dname, p_class(class), p_type(type));
#endif
/*
* Initialize header fields.
*/
if ((buf == NULL) || (buflen < HFIXEDSZ))
return (-1);
memset(buf, 0, HFIXEDSZ);
hp = (HEADER *) buf;
/* We randomize the IDs every time. The old code just
incremented by one after the initial randomization which
still predictable if the application does multiple
requests. */
int randombits;
do
{
#ifdef RANDOM_BITS
RANDOM_BITS (randombits);
#else
struct timeval tv;
__gettimeofday (&tv, NULL);
randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
#endif
}
while ((randombits & 0xffff) == 0);
statp->id = (statp->id + randombits) & 0xffff;
hp->id = statp->id;
hp->opcode = op;
hp->rd = (statp->options & RES_RECURSE) != 0;
hp->rcode = NOERROR;
cp = buf + HFIXEDSZ;
buflen -= HFIXEDSZ;
dpp = dnptrs;
*dpp++ = buf;
*dpp++ = NULL;
lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
/*
* perform opcode specific processing
*/
switch (op) {
case NS_NOTIFY_OP:
if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
return (-1);
goto compose;
case QUERY:
if ((buflen -= QFIXEDSZ) < 0)
return (-1);
compose:
n = ns_name_compress(dname, cp, buflen,
(const u_char **) dnptrs,
(const u_char **) lastdnptr);
if (n < 0)
return (-1);
cp += n;
buflen -= n;
NS_PUT16 (type, cp);
NS_PUT16 (class, cp);
hp->qdcount = htons(1);
if (op == QUERY || data == NULL)
break;
/*
* Make an additional record for completion domain.
*/
n = ns_name_compress((char *)data, cp, buflen,
(const u_char **) dnptrs,
(const u_char **) lastdnptr);
if (__glibc_unlikely (n < 0))
return (-1);
cp += n;
buflen -= n;
NS_PUT16 (T_NULL, cp);
NS_PUT16 (class, cp);
NS_PUT32 (0, cp);
NS_PUT16 (0, cp);
hp->arcount = htons(1);
break;
default:
return (-1);
}
return (cp - buf);
}
libresolv_hidden_def (res_nmkquery)
/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
#ifndef T_OPT
#define T_OPT 41
#endif
int
__res_nopt(res_state statp,
int n0, /* current offset in buffer */
u_char *buf, /* buffer to put query */
int buflen, /* size of buffer */
int anslen) /* UDP answer buffer size */
{
u_int16_t flags = 0;
#ifdef DEBUG
if ((statp->options & RES_DEBUG) != 0U)
printf(";; res_nopt()\n");
#endif
HEADER *hp = (HEADER *) buf;
u_char *cp = buf + n0;
u_char *ep = buf + buflen;
if ((ep - cp) < 1 + RRFIXEDSZ)
return -1;
*cp++ = 0; /* "." */
NS_PUT16(T_OPT, cp); /* TYPE */
/* Lowering the advertised buffer size based on the actual
answer buffer size is desirable because the server will
minimize the reply to fit into the UDP packet (and A
non-minimal response might not fit the buffer).
The RESOLV_EDNS_BUFFER_SIZE limit could still result in TCP
fallback and a non-minimal response which has to be
hard-truncated in the stub resolver, but this is price to
pay for avoiding fragmentation. (This issue does not
affect the nss_dns functions because they use the stub
resolver in such a way that it allocates a properly sized
response buffer.) */
{
uint16_t buffer_size;
if (anslen < 512)
buffer_size = 512;
else if (anslen > RESOLV_EDNS_BUFFER_SIZE)
buffer_size = RESOLV_EDNS_BUFFER_SIZE;
else
buffer_size = anslen;
NS_PUT16 (buffer_size, cp);
}
*cp++ = NOERROR; /* extended RCODE */
*cp++ = 0; /* EDNS version */
if (statp->options & RES_USE_DNSSEC) {
#ifdef DEBUG
if (statp->options & RES_DEBUG)
printf(";; res_opt()... ENDS0 DNSSEC\n");
#endif
flags |= NS_OPT_DNSSEC_OK;
}
NS_PUT16(flags, cp);
NS_PUT16(0, cp); /* RDLEN */
hp->arcount = htons(ntohs(hp->arcount) + 1);
return cp - buf;
}
|
