1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2001
4 * Ported to LTP: Wayne Boyer
5 */
6
7 /*
8 * Test Description :
9 * 1) readlink(2) returns -1 and sets errno to EACCES if search/write
10 * permission is denied in the directory where the symbolic link
11 * resides.
12 * 2) readlink(2) returns -1 and sets errno to EINVAL if the buffer size
13 * is not positive.
14 * 3) readlink(2) returns -1 and sets errno to EINVAL if the specified
15 * file is not a symbolic link file.
16 * 4) readlink(2) returns -1 and sets errno to ENAMETOOLONG if the
17 * pathname component of symbolic link is too long (ie, > PATH_MAX).
18 * 5) readlink(2) returns -1 and sets errno to ENOENT if the component of
19 * symbolic link points to an empty string.
20 * 6) readlink(2) returns -1 and sets errno to ENOTDIR if a component of
21 * the path prefix is not a directory.
22 * 7) readlink(2) returns -1 and sets errno to ELOOP if too many symbolic
23 * links were encountered in translating the pathname.
24 * 8) readlink(2) returns -1 and sets errno to EFAULT if buf outside the
25 * process allocated address space.
26 */
27
28 #include <pwd.h>
29 #include <errno.h>
30 #include <string.h>
31
32 #include "tst_test.h"
33
34 #define DIR_TEMP "test_dir_1"
35 #define TEST_FILE1 "test_dir_1/test_file_1"
36 #define SYM_FILE1 "test_dir_1/slink_file_1"
37 #define TEST_FILE2 "test_file_2"
38 #define SYM_FILE2 "slink_file_2"
39 #define TEST_FILE3 "test_file_3"
40 #define SYM_FILE3 "test_file_3/slink_file_3"
41 #define ELOOPFILE "/test_eloop"
42 #define TESTFILE "test_file"
43 #define SYMFILE "slink_file"
44
45 static char longpathname[PATH_MAX + 2];
46 static char elooppathname[sizeof(ELOOPFILE) * 43] = ".";
47 static char buffer[256];
48
49 static struct tcase {
50 char *link;
51 char *buf;
52 size_t buf_size;
53 int exp_errno;
54 } tcases[] = {
55 {SYM_FILE1, buffer, sizeof(buffer), EACCES},
56 {SYM_FILE2, buffer, 0, EINVAL},
57 {TEST_FILE2, buffer, sizeof(buffer), EINVAL},
58 {longpathname, buffer, sizeof(buffer), ENAMETOOLONG},
59 {"", buffer, sizeof(buffer), ENOENT},
60 {SYM_FILE3, buffer, sizeof(buffer), ENOTDIR},
61 {elooppathname, buffer, sizeof(buffer), ELOOP},
62 {SYMFILE, (char *)-1, sizeof(buffer), EFAULT},
63 };
64
verify_readlink(unsigned int n)65 static void verify_readlink(unsigned int n)
66 {
67 struct tcase *tc = &tcases[n];
68
69 TEST(readlink(tc->link, tc->buf, tc->buf_size));
70 if (TST_RET != -1) {
71 tst_res(TFAIL, "readlink() sueeeeded unexpectedly");
72 return;
73 }
74
75 if (TST_ERR != tc->exp_errno) {
76 tst_res(TFAIL | TTERRNO,
77 "readlink() failed unexpectedly; expected: %d - %s, got",
78 tc->exp_errno, tst_strerrno(tc->exp_errno));
79
80 if (tc->exp_errno == ENOENT && TST_ERR == EINVAL) {
81 tst_res(TWARN | TTERRNO,
82 "It may be a Kernel Bug, see the patch:"
83 "http://git.kernel.org/linus/1fa1e7f6");
84 }
85 } else {
86 tst_res(TPASS | TTERRNO, "readlink() failed as expected");
87 }
88 }
89
setup(void)90 static void setup(void)
91 {
92 int i;
93 struct passwd *pwent;
94
95 pwent = SAFE_GETPWNAM("nobody");
96 SAFE_SETEUID(pwent->pw_uid);
97
98 SAFE_MKDIR(DIR_TEMP, 0777);
99 SAFE_TOUCH(TEST_FILE1, 0666, NULL);
100 SAFE_SYMLINK(TEST_FILE1, SYM_FILE1);
101 SAFE_CHMOD(DIR_TEMP, 0444);
102
103 SAFE_TOUCH(TEST_FILE2, 0666, NULL);
104 SAFE_SYMLINK(TEST_FILE2, SYM_FILE2);
105
106 memset(longpathname, 'a', PATH_MAX + 1);
107
108 SAFE_TOUCH(TEST_FILE3, 0666, NULL);
109
110 SAFE_MKDIR("test_eloop", 0777);
111 SAFE_SYMLINK("../test_eloop", "test_eloop/test_eloop");
112
113 for (i = 0; i < 43; i++)
114 strcat(elooppathname, ELOOPFILE);
115
116 SAFE_TOUCH(TESTFILE, 0666, NULL);
117 SAFE_SYMLINK(TESTFILE, SYMFILE);
118 }
119
120 static struct tst_test test = {
121 .tcnt = ARRAY_SIZE(tcases),
122 .test = verify_readlink,
123 .setup = setup,
124 .needs_tmpdir = 1,
125 .needs_root = 1,
126 };
127