1/* Test the RES_NOAAAA resolver option with a large response.
2 Copyright (C) 2022-2024 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 <errno.h>
20#include <netdb.h>
21#include <resolv.h>
22#include <stdbool.h>
23#include <stdlib.h>
24#include <support/check.h>
25#include <support/check_nss.h>
26#include <support/resolv_test.h>
27#include <support/support.h>
28#include <support/xmemstream.h>
29
30/* Used to keep track of the number of queries. */
31static volatile unsigned int queries;
32
33/* If true, add a large TXT record at the start of the answer section. */
34static volatile bool stuff_txt;
35
36static void
37response (const struct resolv_response_context *ctx,
38 struct resolv_response_builder *b,
39 const char *qname, uint16_t qclass, uint16_t qtype)
40{
41 /* If not using TCP, just force its use. */
42 if (!ctx->tcp)
43 {
44 struct resolv_response_flags flags = {.tc = true};
45 resolv_response_init (b, flags);
46 resolv_response_add_question (b, name: qname, class: qclass, type: qtype);
47 return;
48 }
49
50 /* The test needs to send four queries, the first three are used to
51 grow the NSS buffer via the ERANGE handshake. */
52 ++queries;
53 TEST_VERIFY (queries <= 4);
54
55 /* AAAA queries are supposed to be disabled. */
56 TEST_COMPARE (qtype, T_A);
57 TEST_COMPARE (qclass, C_IN);
58 TEST_COMPARE_STRING (qname, "example.com");
59
60 struct resolv_response_flags flags = {};
61 resolv_response_init (b, flags);
62 resolv_response_add_question (b, name: qname, class: qclass, type: qtype);
63
64 resolv_response_section (b, ns_s_an);
65
66 if (stuff_txt)
67 {
68 resolv_response_open_record (b, name: qname, class: qclass, T_TXT, ttl: 60);
69 int zero = 0;
70 for (int i = 0; i <= 15000; ++i)
71 resolv_response_add_data (b, &zero, sizeof (zero));
72 resolv_response_close_record (b);
73 }
74
75 for (int i = 0; i < 200; ++i)
76 {
77 resolv_response_open_record (b, name: qname, class: qclass, type: qtype, ttl: 60);
78 char ipv4[4] = {192, 0, 2, i + 1};
79 resolv_response_add_data (b, &ipv4, sizeof (ipv4));
80 resolv_response_close_record (b);
81 }
82}
83
84static int
85do_test (void)
86{
87 struct resolv_test *obj = resolv_test_start
88 ((struct resolv_redirect_config)
89 {
90 .response_callback = response
91 });
92
93 _res.options |= RES_NOAAAA;
94
95 for (int do_stuff_txt = 0; do_stuff_txt < 2; ++do_stuff_txt)
96 {
97 queries = 0;
98 stuff_txt = do_stuff_txt;
99
100 struct addrinfo *ai = NULL;
101 int ret;
102 ret = getaddrinfo (name: "example.com", service: "80",
103 req: &(struct addrinfo)
104 {
105 .ai_family = AF_UNSPEC,
106 .ai_socktype = SOCK_STREAM,
107 }, pai: &ai);
108
109 char *expected_result;
110 {
111 struct xmemstream mem;
112 xopen_memstream (stream: &mem);
113 for (int i = 0; i < 200; ++i)
114 fprintf (stream: mem.out, format: "address: STREAM/TCP 192.0.2.%d 80\n", i + 1);
115 xfclose_memstream (stream: &mem);
116 expected_result = mem.buffer;
117 }
118
119 check_addrinfo (query_description: "example.com", ai, ret, expected: expected_result);
120
121 free (ptr: expected_result);
122 freeaddrinfo (ai: ai);
123 }
124
125 resolv_test_end (obj);
126 return 0;
127}
128
129#include <support/test-driver.c>
130

source code of glibc/resolv/tst-resolv-noaaaa-vc.c