xref: /freebsd/tools/regression/priv/priv_io.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*-
2  * Copyright (c) 2006 nCircle Network Security, Inc.
3  * Copyright (c) 2007 Robert N. M. Watson
4  * All rights reserved.
5  *
6  * This software was developed by Robert N. M. Watson for the TrustedBSD
7  * Project under contract to nCircle Network Security, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
22  * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
24  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
25  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
26  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
27  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * Test privilege check on /dev/io.  By default, the permissions also protect
33  * against non-superuser access, so this program will modify permissions on
34  * /dev/io to allow world access, and revert the change on exit.  This is not
35  * good for run-time security, but is necessary to test the checks properly.
36  */
37 
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 
41 #include <err.h>
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <unistd.h>
45 
46 #include "main.h"
47 
48 #define	NEW_PERMS	0666
49 #define	DEV_IO		"/dev/io"
50 #define	EXPECTED_PERMS	0600
51 
52 static int initialized;
53 static mode_t saved_perms;
54 
55 int
56 priv_io_setup(int asroot, int asjail, struct test *test)
57 {
58 	struct stat sb;
59 
60 	if (stat(DEV_IO, &sb) < 0) {
61 		warn("priv_io_setup: stat(%s)", DEV_IO);
62 		return (-1);
63 	}
64 	saved_perms = sb.st_mode & ALLPERMS;
65 	if (saved_perms != EXPECTED_PERMS) {
66 		warnx("priv_io_setup: perms = 0%o; expected 0%o",
67 		    saved_perms, EXPECTED_PERMS);
68 		return (-1);
69 	}
70 	if (chmod(DEV_IO, NEW_PERMS) < 0) {
71 		warn("priv_io_setup: chmod(%s, 0%o)", DEV_IO, NEW_PERMS);
72 		return (-1);
73 	}
74 	initialized = 1;
75 	return (0);
76 }
77 
78 void
79 priv_io(int asroot, int injail, struct test *test)
80 {
81 	int error, fd;
82 
83 	fd = open(DEV_IO, O_RDONLY);
84 	if (fd < 0)
85 		error = -1;
86 	else
87 		error = 0;
88 	if (asroot && injail)
89 		expect("priv_io(asroot, injail)", error, -1, EPERM);
90 	if (asroot && !injail)
91 		expect("priv_io(asroot, !injail)", error, 0, 0);
92 	if (!asroot && injail)
93 		expect("priv_io(!asroot, injail)", error, -1, EPERM);
94 	if (!asroot && !injail)
95 		expect("priv_io(!asroot, !injail)", error, -1, EPERM);
96 	if (fd != -1)
97 		close(fd);
98 }
99 
100 void
101 priv_io_cleanup(int asroot, int asjail, struct test *test)
102 {
103 
104 	if (!initialized)
105 		return;
106 	if (chmod(DEV_IO, saved_perms) < 0)
107 		err(-1, "priv_io_cleanup: chmod(%s, 0%o)", DEV_IO,
108 		    saved_perms);
109 	initialized = 0;
110 }
111