1 /* Test handling of binary domain names with res_send.
2 Copyright (C) 2018-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <resolv.h>
20 #include <string.h>
21 #include <support/check.h>
22 #include <support/resolv_test.h>
23
24 static void
25 response (const struct resolv_response_context *ctx,
26 struct resolv_response_builder *b,
27 const char *qname, uint16_t qclass, uint16_t qtype)
28 {
29 TEST_COMPARE (qclass, C_IN);
30 TEST_COMPARE (qtype, T_TXT);
31 TEST_VERIFY (strlen (qname) <= 255);
32
33 struct resolv_response_flags flags = { 0 };
34 resolv_response_init (b, flags);
35 resolv_response_add_question (b, qname, qclass, qtype);
36 resolv_response_section (b, ns_s_an);
37 resolv_response_open_record (b, qname, qclass, T_TXT, 0x12345678);
38 unsigned char qnamelen = strlen (qname);
39 resolv_response_add_data (b, &qnamelen, 1);
40 resolv_response_add_data (b, qname, qnamelen);
41 resolv_response_close_record (b);
42 }
43
44 static int
45 do_test (void)
46 {
47 struct resolv_test *aux = resolv_test_start
48 ((struct resolv_redirect_config)
49 {
50 .response_callback = response,
51 });
52
53 for (int b = 0; b <= 255; ++b)
54 {
55 unsigned char query[] =
56 {
57 b, b, /* Transaction ID. */
58 1, 0, /* Query with RD flag. */
59 0, 1, /* One question. */
60 0, 0, 0, 0, 0, 0, /* The other sections are empty. */
61 1, b, 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 0,
62 0, T_TXT, /* TXT query. */
63 0, 1, /* Class IN. */
64 };
65 unsigned char response[512];
66 int ret = res_send (query, sizeof (query), response, sizeof (response));
67
68 char expected_name[20];
69 /* The name is uncompressed in the query, so we can reference it
70 directly. */
71 TEST_VERIFY_EXIT (ns_name_ntop (query + 12, expected_name,
72 sizeof (expected_name)) >= 0);
73 TEST_COMPARE (ret,
74 (ssize_t) sizeof (query)
75 + 2 /* Compression reference. */
76 + 2 + 2 + 4 + 2 /* Type, class, TTL, RDATA length. */
77 + 1 /* Pascal-style string length. */
78 + strlen (expected_name));
79
80 /* Mark as answer, with recursion available, and one answer. */
81 query[2] = 0x81;
82 query[3] = 0x80;
83 query[7] = 1;
84
85 /* Prefix of the response must match the query. */
86 TEST_COMPARE (memcmp (response, query, sizeof (query)), 0);
87
88 /* The actual answer follows, starting with the compression
89 reference. */
90 unsigned char *p = response + sizeof (query);
91 TEST_COMPARE (*p++, 0xc0);
92 TEST_COMPARE (*p++, 0x0c);
93
94 /* Type and class. */
95 TEST_COMPARE (*p++, 0);
96 TEST_COMPARE (*p++, T_TXT);
97 TEST_COMPARE (*p++, 0);
98 TEST_COMPARE (*p++, C_IN);
99
100 /* TTL. */
101 TEST_COMPARE (*p++, 0x12);
102 TEST_COMPARE (*p++, 0x34);
103 TEST_COMPARE (*p++, 0x56);
104 TEST_COMPARE (*p++, 0x78);
105
106 /* RDATA length. */
107 TEST_COMPARE (*p++, 0);
108 TEST_COMPARE (*p++, 1 + strlen (expected_name));
109
110 /* RDATA. */
111 TEST_COMPARE (*p++, strlen (expected_name));
112 TEST_COMPARE (memcmp (p, expected_name, strlen (expected_name)), 0);
113 }
114
115 resolv_test_end (aux);
116
117 return 0;
118 }
119
120 #include <support/test-driver.c>