1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License version 2.
4 *
5 * This program is distributed in the hope that it will be useful,
6 * but WITHOUT ANY WARRANTY; without even the implied warranty of
7 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
8 * GNU General Public License for more details.
9 *
10 * Test that the named shared memory object is not changed by this function
11 * call when the process does not have permission to unlink the name.
12 *
13 * Steps:
14 * 1. Create a shared memory object.
15 * 2. Set his effective user id to an other user id which is not root.
16 * 3. Try to unlink the name.
17 * If it fail: set the effective user id to real user id and unlink.
18 * In most case this test will be unresolved if not run by root.
19 */
20
21 /* getpwent() is part of XSI option */
22
23 #include <stdio.h>
24 #include <sys/mman.h>
25 #include <sys/stat.h>
26 #include <unistd.h>
27 #include <fcntl.h>
28 #include <errno.h>
29 #include <pwd.h>
30 #include <string.h>
31 #include "posixtest.h"
32
33 #define SHM_NAME "posixtest_9-1"
34 #define BUF_SIZE 8
35
main(void)36 int main(void)
37 {
38 int fd, result;
39 struct passwd *pw;
40 struct stat stat_before, stat_after;
41
42 fd = shm_open(SHM_NAME, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
43 if (fd == -1) {
44 perror("An error occurs when calling shm_open()");
45 return PTS_UNRESOLVED;
46 }
47
48 if (ftruncate(fd, BUF_SIZE) != 0) {
49 perror("An error occurs when calling ftruncate()");
50 shm_unlink(SHM_NAME);
51 return PTS_UNRESOLVED;
52 }
53
54 if (fstat(fd, &stat_before) != 0) {
55 perror("An error occurs when calling fstat()");
56 shm_unlink(SHM_NAME);
57 return PTS_UNRESOLVED;
58 }
59
60 /* search for the first user which is non root and which is not the
61 current user */
62 while ((pw = getpwent()) != NULL)
63 if (strcmp(pw->pw_name, "root") && pw->pw_uid != getuid())
64 break;
65
66 if (pw == NULL) {
67 printf("There is no other user than current and root.\n");
68 return PTS_UNRESOLVED;
69 }
70
71 if (seteuid(pw->pw_uid) != 0) {
72 if (errno == EPERM) {
73 printf
74 ("You don't have permission to change your UID.\nTry to rerun this test as root.\n");
75 return PTS_UNRESOLVED;
76 }
77 perror("An error occurs when calling seteuid()");
78 return PTS_UNRESOLVED;
79 }
80
81 printf("Testing with user '%s' (uid: %i)\n", pw->pw_name, pw->pw_uid);
82
83 result = shm_unlink(SHM_NAME);
84 if (result == 0) {
85 printf("shm_unlink() success.\n");
86 return PTS_UNRESOLVED;
87 }
88
89 if (seteuid(getuid()))
90 perror("seteuid");
91
92 if (fstat(fd, &stat_after) != 0) {
93 perror("An error occurs when calling fstat()");
94 shm_unlink(SHM_NAME);
95 return PTS_UNRESOLVED;
96 }
97
98 if (stat_after.st_uid != stat_before.st_uid ||
99 stat_after.st_gid != stat_before.st_gid ||
100 stat_after.st_size != stat_before.st_size ||
101 stat_after.st_mode != stat_before.st_mode) {
102 printf("The shared memory object has changed.\n");
103 return PTS_FAIL;
104 }
105
106 printf("Test PASSED\n");
107 return PTS_PASS;
108
109 }
110