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#include <support/xunistd.h>
10
11static void prepare (void);
12#define PREPARE(argc, argv) prepare ()
13
14static int do_test (void);
15#define TEST_FUNCTION do_test ()
16
17#include "../test-skeleton.c"
18
19static int dir_fd;
20
21static void
22prepare (void)
23{
24 size_t test_dir_len = strlen (test_dir);
25 static const char dir_name[] = "/tst-linkat.XXXXXX";
26
27 size_t dirbuflen = test_dir_len + sizeof (dir_name);
28 char *dirbuf = malloc (size: dirbuflen);
29 if (dirbuf == NULL)
30 {
31 puts (s: "out of memory");
32 exit (1);
33 }
34
35 snprintf (s: dirbuf, maxlen: dirbuflen, format: "%s%s", test_dir, dir_name);
36 if (mkdtemp (template: dirbuf) == NULL)
37 {
38 puts (s: "cannot create temporary directory");
39 exit (1);
40 }
41
42 add_temp_file (name: dirbuf);
43
44 dir_fd = open (file: dirbuf, O_RDONLY | O_DIRECTORY);
45 if (dir_fd == -1)
46 {
47 puts (s: "cannot open directory");
48 exit (1);
49 }
50}
51
52
53static int
54do_test (void)
55{
56 /* fdopendir takes over the descriptor, make a copy. */
57 int dupfd = dup (fd: dir_fd);
58 if (dupfd == -1)
59 {
60 puts (s: "dup failed");
61 return 1;
62 }
63 if (lseek (fd: dupfd, offset: 0, SEEK_SET) != 0)
64 {
65 puts (s: "1st lseek failed");
66 return 1;
67 }
68
69 /* The directory should be empty safe the . and .. files. */
70 DIR *dir = fdopendir (fd: dupfd);
71 if (dir == NULL)
72 {
73 puts (s: "fdopendir failed");
74 return 1;
75 }
76 struct dirent64 *d;
77 while ((d = readdir64 (dirp: dir)) != NULL)
78 if (strcmp (d->d_name, ".") != 0 && strcmp (d->d_name, "..") != 0)
79 {
80 printf (format: "temp directory contains file \"%s\"\n", d->d_name);
81 return 1;
82 }
83 closedir (dirp: dir);
84
85 /* Try to create a file. */
86 int fd = openat (fd: dir_fd, file: "some-file", O_CREAT|O_RDWR|O_EXCL, 0666);
87 if (fd == -1)
88 {
89 if (errno == ENOSYS)
90 {
91 puts (s: "*at functions not supported");
92 return 0;
93 }
94
95 puts (s: "file creation failed");
96 return 1;
97 }
98 xwrite (fd, "hello", 5);
99 puts (s: "file created");
100
101 struct stat64 st1;
102 if (fstat64 (fd: fd, buf: &st1) != 0)
103 {
104 puts (s: "fstat64 failed");
105 return 1;
106 }
107
108 close (fd: fd);
109
110 if (linkat (fromfd: dir_fd, from: "some-file", tofd: dir_fd, to: "another-file", flags: 0) != 0)
111 {
112 puts (s: "symlinkat failed");
113 return 1;
114 }
115
116 struct stat64 st2;
117 if (fstatat64 (fd: dir_fd, file: "some-file", buf: &st2, flag: 0) != 0)
118 {
119 puts (s: "fstatat64 failed");
120 return 1;
121 }
122 if (st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
123 {
124 puts (s: "file changed after symlinkat");
125 return 1;
126 }
127
128 if (fstatat64 (fd: dir_fd, file: "another-file", buf: &st2, AT_SYMLINK_NOFOLLOW) != 0)
129 {
130 puts (s: "2nd fstatat64 failed");
131 return 1;
132 }
133 if (S_ISLNK (st2.st_mode))
134 {
135 puts (s: "2nd fstatat64 shows file is a symlink");
136 return 1;
137 }
138 if (st1.st_dev != st2.st_dev
139 || st1.st_ino != st2.st_ino
140 || st1.st_size != st2.st_size)
141 {
142 puts (s: "stat results for linked file do not match");
143 return 1;
144 }
145
146 if (fstatat64 (fd: dir_fd, file: "another-file", buf: &st2, flag: 0) != 0)
147 {
148 puts (s: "3rd fstatat64 failed");
149 return 1;
150 }
151 if (st1.st_dev != st2.st_dev
152 || st1.st_ino != st2.st_ino
153 || st1.st_size != st2.st_size)
154 {
155 puts (s: "stat results do not match");
156 return 1;
157 }
158
159 if (unlinkat (fd: dir_fd, name: "another-file", flag: 0) != 0)
160 {
161 puts (s: "unlinkat failed");
162 return 1;
163 }
164 if (unlinkat (fd: dir_fd, name: "some-file", flag: 0) != 0)
165 {
166 puts (s: "2nd unlinkat failed");
167 return 1;
168 }
169
170 close (fd: dir_fd);
171
172 return 0;
173}
174

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