1#include <dirent.h>
2#include <fcntl.h>
3#include <stdio.h>
4#include <stdlib.h>
5#include <string.h>
6#include <unistd.h>
7#include <sys/stat.h>
8
9
10static void prepare (void);
11#define PREPARE(argc, argv) prepare ()
12
13static int do_test (void);
14#define TEST_FUNCTION do_test ()
15
16#include "../test-skeleton.c"
17
18static int dir_fd;
19
20static void
21prepare (void)
22{
23#if _POSIX_CHOWN_RESTRICTED == 0
24 if (pathconf (path: test_dir, _PC_CHOWN_RESTRICTED) != 0)
25#endif
26 {
27 uid_t uid = getuid ();
28 if (uid != 0)
29 {
30 puts (s: "need root privileges");
31 exit (0);
32 }
33 }
34
35 size_t test_dir_len = strlen (test_dir);
36 static const char dir_name[] = "/tst-fchownat.XXXXXX";
37
38 size_t dirbuflen = test_dir_len + sizeof (dir_name);
39 char *dirbuf = malloc (size: dirbuflen);
40 if (dirbuf == NULL)
41 {
42 puts (s: "out of memory");
43 exit (1);
44 }
45
46 snprintf (s: dirbuf, maxlen: dirbuflen, format: "%s%s", test_dir, dir_name);
47 if (mkdtemp (template: dirbuf) == NULL)
48 {
49 puts (s: "cannot create temporary directory");
50 exit (1);
51 }
52
53 add_temp_file (name: dirbuf);
54
55 dir_fd = open (file: dirbuf, O_RDONLY | O_DIRECTORY);
56 if (dir_fd == -1)
57 {
58 puts (s: "cannot open directory");
59 exit (1);
60 }
61}
62
63
64static int
65do_test (void)
66{
67 /* fdopendir takes over the descriptor, make a copy. */
68 int dupfd = dup (fd: dir_fd);
69 if (dupfd == -1)
70 {
71 puts (s: "dup failed");
72 return 1;
73 }
74 if (lseek (fd: dupfd, offset: 0, SEEK_SET) != 0)
75 {
76 puts (s: "1st lseek failed");
77 return 1;
78 }
79
80 /* The directory should be empty safe the . and .. files. */
81 DIR *dir = fdopendir (fd: dupfd);
82 if (dir == NULL)
83 {
84 puts (s: "fdopendir failed");
85 return 1;
86 }
87 struct dirent64 *d;
88 while ((d = readdir64 (dirp: dir)) != NULL)
89 if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)
90 {
91 printf (format: "temp directory contains file \"%s\"\n", d->d_name);
92 return 1;
93 }
94 closedir (dirp: dir);
95
96 /* Try to create a file. */
97 int fd = openat (fd: dir_fd, file: "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);
98 if (fd == -1)
99 {
100 if (errno == ENOSYS)
101 {
102 puts (s: "*at functions not supported");
103 return 0;
104 }
105
106 puts (s: "file creation failed");
107 return 1;
108 }
109 write (fd, "hello", 5);
110 puts (s: "file created");
111
112 struct stat64 st1;
113 if (fstat64 (fd: fd, buf: &st1) != 0)
114 {
115 puts (s: "fstat64 failed");
116 return 1;
117 }
118
119 /* Before closing the file, try using this file descriptor to open
120 another file. This must fail. */
121 if (fchownat (fd: fd, file: "some-file", owner: 1, group: 1, flag: 0) != -1)
122 {
123 puts (s: "fchownat using descriptor for normal file worked");
124 return 1;
125 }
126 if (errno != ENOTDIR)
127 {
128 puts (s: "\
129error for fchownat using descriptor for normal file not ENOTDIR ");
130 return 1;
131 }
132
133 close (fd: fd);
134
135 if (fchownat (fd: dir_fd, file: "some-file", owner: st1.st_uid + 1, group: st1.st_gid + 1, flag: 0) != 0)
136 {
137 puts (s: "fchownat failed");
138 return 1;
139 }
140
141 struct stat64 st2;
142 if (fstatat64 (fd: dir_fd, file: "some-file", buf: &st2, flag: 0) != 0)
143 {
144 puts (s: "fstatat64 failed");
145 return 1;
146 }
147
148 if (st1.st_uid + 1 != st2.st_uid || st1.st_gid + 1 != st2.st_gid)
149 {
150 puts (s: "owner change failed");
151 return 1;
152 }
153
154 if (unlinkat (fd: dir_fd, name: "some-file", flag: 0) != 0)
155 {
156 puts (s: "unlinkat failed");
157 return 1;
158 }
159
160 /* Create a file descriptor which is closed again right away. */
161 int dir_fd2 = dup (fd: dir_fd);
162 if (dir_fd2 == -1)
163 {
164 puts (s: "dup failed");
165 return 1;
166 }
167 close (fd: dir_fd2);
168
169 if (fchownat (fd: dir_fd2, file: "some-file", owner: 1, group: 1, flag: 0) != -1)
170 {
171 puts (s: "fchownat using closed descriptor worked");
172 return 1;
173 }
174 if (errno != EBADF)
175 {
176 puts (s: "error for fchownat using closed descriptor not EBADF ");
177 return 1;
178 }
179
180 close (fd: dir_fd);
181
182 if (fchownat (fd: -1, file: "some-file", owner: 1, group: 1, flag: 0) != -1)
183 {
184 puts (s: "fchownat using invalid descriptor worked");
185 return 1;
186 }
187 if (errno != EBADF)
188 {
189 puts (s: "error for fchownat using invalid descriptor not EBADF ");
190 return 1;
191 }
192
193 return 0;
194}
195

source code of glibc/io/tst-fchownat.c