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#define _XOPEN_SOURCE 600
23
24#include <stdio.h>
25#include <sys/mman.h>
26#include <sys/stat.h>
27#include <unistd.h>
28#include <fcntl.h>
29#include <errno.h>
30#include <pwd.h>
31#include <string.h>
32#include "posixtest.h"
33
34#define SHM_NAME "posixtest_9-1"
35#define BUF_SIZE 8
36
37
38int main() {
39	int fd, result;
40	struct passwd *pw;
41	struct stat stat_before, stat_after;
42
43	fd = shm_open(SHM_NAME, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR);
44	if(fd == -1) {
45		perror("An error occurs when calling shm_open()");
46		return PTS_UNRESOLVED;
47	}
48
49	if(ftruncate(fd, BUF_SIZE) != 0) {
50		perror("An error occurs when calling ftruncate()");
51		shm_unlink(SHM_NAME);
52		return PTS_UNRESOLVED;
53	}
54
55	if(fstat(fd, &stat_before) != 0) {
56		perror("An error occurs when calling fstat()");
57		shm_unlink(SHM_NAME);
58		return PTS_UNRESOLVED;
59	}
60
61	/* search for the first user which is non root and which is not the
62	   current user */
63	while((pw = getpwent()) != NULL)
64		if(strcmp(pw->pw_name, "root") && pw->pw_uid != getuid())
65			break;
66
67	if(pw == NULL) {
68		printf("There is no other user than current and root.\n");
69		return PTS_UNRESOLVED;
70	}
71
72	if(seteuid(pw->pw_uid) != 0) {
73		if(errno == EPERM) {
74			printf("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",
82	       pw->pw_name, pw->pw_uid);
83
84	result = shm_unlink(SHM_NAME);
85	if(result == 0) {
86		printf("shm_unlink() success.\n");
87		return PTS_UNRESOLVED;
88	}
89
90	seteuid(getuid());
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