1 /*
2  * Copyright (C) Bull S.A. 2001
3  * Copyright (c) International Business Machines  Corp., 2001
4  * 06/2002 Ported by Jacky Malcles
5  * Copyright (c) 2014 Cyril Hrubis <chrubis@suse.cz>
6  *
7  * This program is free software;  you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
15  * the GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program;  if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /*
23  * Verify that, link() fails with -1 and sets errno to EACCES when Write access
24  * to the directory containing newpath is not allowed for the process's
25  * effective uid.
26  */
27 
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <unistd.h>
31 #include <fcntl.h>
32 #include <errno.h>
33 #include <string.h>
34 #include <signal.h>
35 #include <sys/types.h>
36 #include <sys/stat.h>
37 #include <pwd.h>
38 
39 #include "test.h"
40 #include "safe_macros.h"
41 
42 #define NOBODY_USER	99
43 #define MODE_TO S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IXOTH|S_IROTH
44 
45 static void setup(void);
46 static void cleanup(void);
47 
48 char *TCID = "link06";
49 int TST_TOTAL = 1;
50 
51 #define OLDPATH "oldpath"
52 #define NEWPATH "newpath"
53 
54 int main(int ac, char **av)
55 {
56 	int lc;
57 
58 	tst_parse_opts(ac, av, NULL, NULL);
59 
60 	setup();
61 
62 	for (lc = 0; TEST_LOOPING(lc); lc++) {
63 		tst_count = 0;
64 
65 		TEST(link(OLDPATH, NEWPATH));
66 
67 		if (TEST_RETURN != -1) {
68 			tst_resm(TFAIL, "link() returned %ld,"
69 				 "expected -1, errno=%d", TEST_RETURN,
70 				 EACCES);
71 		} else {
72 			if (TEST_ERRNO == EACCES) {
73 				tst_resm(TPASS, "link() fails with expected "
74 					 "error EACCES errno:%d", TEST_ERRNO);
75 			} else {
76 				tst_resm(TFAIL, "link() fails with "
77 					 "errno=%d, expected errno=%d",
78 					 TEST_ERRNO, EACCES);
79 			}
80 		}
81 	}
82 
83 	cleanup();
84 	tst_exit();
85 }
86 
87 static void setup(void)
88 {
89 	struct passwd *nobody_pwd;
90 
91 	tst_sig(NOFORK, DEF_HANDLER, cleanup);
92 
93 	tst_require_root();
94 
95 	TEST_PAUSE;
96 
97 	tst_tmpdir();
98 
99 	/* Modify mode permissions on test directory */
100 	SAFE_CHMOD(cleanup, ".", MODE_TO);
101 
102 	SAFE_TOUCH(cleanup, OLDPATH, 0777, NULL);
103 	nobody_pwd = SAFE_GETPWNAM(cleanup, "nobody");
104 	SAFE_SETEUID(cleanup, nobody_pwd->pw_uid);
105 }
106 
107 static void cleanup(void)
108 {
109 	if (seteuid(0))
110 		tst_resm(TWARN | TERRNO, "seteuid(0) failed");
111 
112 	tst_rmdir();
113 }
114