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
|
/* Test the behavior of the trust-ad option.
Copyright (C) 2019-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <support/check.h>
#include <support/check_nss.h>
#include <support/resolv_test.h>
#include <support/support.h>
/* This controls properties of the response. volatile because
__res_send is incorrectly declared as __THROW. */
static volatile unsigned char response_number;
static volatile bool response_ad_bit;
static volatile bool query_ad_bit;
static void
response (const struct resolv_response_context *ctx,
struct resolv_response_builder *b,
const char *qname, uint16_t qclass, uint16_t qtype)
{
TEST_COMPARE (qclass, C_IN);
TEST_COMPARE (qtype, T_A);
TEST_COMPARE_STRING (qname, "www.example");
HEADER header;
memcpy (&header, ctx->query_buffer, sizeof (header));
TEST_COMPARE (header.ad, query_ad_bit);
struct resolv_response_flags flags = { .ad = response_ad_bit, };
resolv_response_init (b, flags);
resolv_response_add_question (b, qname, qclass, qtype);
resolv_response_section (b, ns_s_an);
resolv_response_open_record (b, qname, qclass, T_A, 0x12345678);
char addr[4] = { 192, 0, 2, response_number };
resolv_response_add_data (b, addr, sizeof (addr));
resolv_response_close_record (b);
}
static void
check_answer (const unsigned char *buffer, size_t buffer_length,
bool expected_ad)
{
HEADER header;
TEST_VERIFY (buffer_length > sizeof (header));
memcpy (&header, buffer, sizeof (header));
TEST_COMPARE (0, header.aa);
TEST_COMPARE (expected_ad, header.ad);
TEST_COMPARE (0, header.opcode);
TEST_COMPARE (1, header.qr);
TEST_COMPARE (0, header.rcode);
TEST_COMPARE (1, header.rd);
TEST_COMPARE (0, header.tc);
TEST_COMPARE (1, ntohs (header.qdcount));
TEST_COMPARE (1, ntohs (header.ancount));
TEST_COMPARE (0, ntohs (header.nscount));
TEST_COMPARE (0, ntohs (header.arcount));
char *description = xasprintf ("response=%d ad=%d",
response_number, expected_ad);
char *expected = xasprintf ("name: www.example\n"
"address: 192.0.2.%d\n", response_number);
check_dns_packet (description, buffer, buffer_length, expected);
free (expected);
free (description);
}
static int
do_test (void)
{
struct resolv_test *aux = resolv_test_start
((struct resolv_redirect_config)
{
.response_callback = response,
});
/* By default, the resolver is not trusted, and the AD bit is
cleared. */
static const unsigned char hand_crafted_query[] =
{
10, 11, /* Transaction ID. */
1, 0x20, /* Query with RD, AD flags. */
0, 1, /* One question. */
0, 0, 0, 0, 0, 0, /* The other sections are empty. */
3, 'w', 'w', 'w', 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 0,
0, T_A, /* A query. */
0, 1, /* Class IN. */
};
++response_number;
response_ad_bit = false;
unsigned char buffer[512];
memset (buffer, 255, sizeof (buffer));
query_ad_bit = true;
int ret = res_send (hand_crafted_query, sizeof (hand_crafted_query),
buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
++response_number;
memset (buffer, 255, sizeof (buffer));
query_ad_bit = false;
ret = res_query ("www.example", C_IN, T_A, buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
response_ad_bit = true;
response_ad_bit = true;
++response_number;
query_ad_bit = true;
ret = res_send (hand_crafted_query, sizeof (hand_crafted_query),
buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
++response_number;
memset (buffer, 255, sizeof (buffer));
query_ad_bit = false;
ret = res_query ("www.example", C_IN, T_A, buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
/* No AD bit set in generated queries. */
memset (buffer, 255, sizeof (buffer));
ret = res_mkquery (QUERY, "www.example", C_IN, T_A,
(const unsigned char *) "", 0, NULL,
buffer, sizeof (buffer));
HEADER header;
memcpy (&header, buffer, sizeof (header));
TEST_VERIFY (!header.ad);
/* With RES_TRUSTAD, the AD bit is passed through if it set in the
response. It is also included in queries. */
_res.options |= RES_TRUSTAD;
query_ad_bit = true;
response_ad_bit = false;
++response_number;
memset (buffer, 255, sizeof (buffer));
ret = res_send (hand_crafted_query, sizeof (hand_crafted_query),
buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
++response_number;
memset (buffer, 255, sizeof (buffer));
ret = res_query ("www.example", C_IN, T_A, buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, false);
response_ad_bit = true;
++response_number;
memset (buffer, 0, sizeof (buffer));
ret = res_send (hand_crafted_query, sizeof (hand_crafted_query),
buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, true);
++response_number;
memset (buffer, 0, sizeof (buffer));
ret = res_query ("www.example", C_IN, T_A, buffer, sizeof (buffer));
TEST_VERIFY (ret > 0);
check_answer (buffer, ret, true);
/* AD bit set in generated queries. */
memset (buffer, 0, sizeof (buffer));
ret = res_mkquery (QUERY, "www.example", C_IN, T_A,
(const unsigned char *) "", 0, NULL,
buffer, sizeof (buffer));
memcpy (&header, buffer, sizeof (header));
TEST_VERIFY (header.ad);
resolv_test_end (aux);
return 0;
}
#include <support/test-driver.c>
|
