1 | /* Test __ns_name_length_uncompressed. |
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 <arpa/nameser.h> |
20 | #include <array_length.h> |
21 | #include <errno.h> |
22 | #include <stdio.h> |
23 | #include <support/check.h> |
24 | #include <support/next_to_fault.h> |
25 | |
26 | /* Reference implementation based on other building blocks. */ |
27 | static int |
28 | reference_length (const unsigned char *p, const unsigned char *eom) |
29 | { |
30 | unsigned char buf[NS_MAXCDNAME]; |
31 | int n = __ns_name_unpack (p, eom, p, buf, sizeof (buf)); |
32 | if (n < 0) |
33 | return n; |
34 | const unsigned char *q = buf; |
35 | if (__ns_name_skip (&q, array_end (buf)) < 0) |
36 | return -1; |
37 | if (q - buf != n) |
38 | /* Compressed name. */ |
39 | return -1; |
40 | return n; |
41 | } |
42 | |
43 | static int |
44 | do_test (void) |
45 | { |
46 | { |
47 | unsigned char buf[] = { 3, 'w', 'w', 'w', 0, 0, 0 }; |
48 | TEST_COMPARE (reference_length (buf, array_end (buf)), sizeof (buf) - 2); |
49 | TEST_COMPARE (__ns_name_length_uncompressed (buf, array_end (buf)), |
50 | sizeof (buf) - 2); |
51 | TEST_COMPARE (reference_length (array_end (buf) - 1, array_end (buf)), 1); |
52 | TEST_COMPARE (__ns_name_length_uncompressed (array_end (buf) - 1, |
53 | array_end (buf)), 1); |
54 | buf[4] = 0xc0; /* Forward compression reference. */ |
55 | buf[5] = 0x06; |
56 | TEST_COMPARE (reference_length (buf, array_end (buf)), -1); |
57 | TEST_COMPARE (__ns_name_length_uncompressed (buf, array_end (buf)), -1); |
58 | } |
59 | |
60 | struct support_next_to_fault ntf = support_next_to_fault_allocate (size: 300); |
61 | |
62 | /* Buffer region with all possible bytes at start and end. */ |
63 | for (int length = 1; length <= 300; ++length) |
64 | { |
65 | unsigned char *end = (unsigned char *) ntf.buffer + ntf.length; |
66 | unsigned char *start = end - length; |
67 | memset (s: start, c: 'X', n: length); |
68 | for (int first = 0; first <= 255; ++first) |
69 | { |
70 | *start = first; |
71 | for (int last = 0; last <= 255; ++last) |
72 | { |
73 | start[length - 1] = last; |
74 | TEST_COMPARE (reference_length (start, end), |
75 | __ns_name_length_uncompressed (start, end)); |
76 | } |
77 | } |
78 | } |
79 | |
80 | /* Poor man's fuzz testing: patch two bytes. */ |
81 | { |
82 | unsigned char ref[] = |
83 | { |
84 | 7, 'e', 'x', 'a', 'm', 'p', 'l', 'e', 3, 'n', 'e', 't', 0, 0, 0 |
85 | }; |
86 | TEST_COMPARE (reference_length (ref, array_end (ref)), 13); |
87 | TEST_COMPARE (__ns_name_length_uncompressed (ref, array_end (ref)), 13); |
88 | |
89 | int good = 0; |
90 | int bad = 0; |
91 | for (int length = 1; length <= sizeof (ref); ++length) |
92 | { |
93 | unsigned char *end = (unsigned char *) ntf.buffer + ntf.length; |
94 | unsigned char *start = end - length; |
95 | memcpy (dest: start, src: ref, n: length); |
96 | |
97 | for (int patch1_pos = 0; patch1_pos < length; ++patch1_pos) |
98 | { |
99 | for (int patch1_value = 0; patch1_value <= 255; ++patch1_value) |
100 | { |
101 | start[patch1_pos] = patch1_value; |
102 | for (int patch2_pos = 0; patch2_pos < length; ++patch2_pos) |
103 | { |
104 | for (int patch2_value = 0; patch2_value <= 255; |
105 | ++patch2_value) |
106 | { |
107 | start[patch2_pos] = patch2_value; |
108 | int expected = reference_length (p: start, eom: end); |
109 | errno = EINVAL; |
110 | int actual |
111 | = __ns_name_length_uncompressed (p: start, eom: end); |
112 | if (actual > 0) |
113 | ++good; |
114 | else |
115 | { |
116 | TEST_COMPARE (errno, EMSGSIZE); |
117 | ++bad; |
118 | } |
119 | TEST_COMPARE (expected, actual); |
120 | } |
121 | start[patch2_pos] = ref[patch2_pos]; |
122 | } |
123 | } |
124 | start[patch1_pos] = ref[patch1_pos]; |
125 | } |
126 | } |
127 | printf (format: "info: patched inputs with success: %d\n" , good); |
128 | printf (format: "info: patched inputs with failure: %d\n" , bad); |
129 | } |
130 | |
131 | support_next_to_fault_free (&ntf); |
132 | return 0; |
133 | } |
134 | |
135 | #include <support/test-driver.c> |
136 | |