xref: /freebsd/lib/libcapsicum/capsicum_helpers.h (revision 63d1fd5970ec814904aa0f4580b10a0d302d08b2)
1 /*-
2  * Copyright (c) 2016 Mariusz Zaborski <oshogbo@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _CAPSICUM_HELPERS_H_
30 #define	_CAPSICUM_HELPERS_H_
31 
32 #include <sys/param.h>
33 #include <sys/capsicum.h>
34 
35 #include <errno.h>
36 #include <nl_types.h>
37 #include <termios.h>
38 #include <time.h>
39 #include <unistd.h>
40 
41 #define	CAPH_IGNORE_EBADF	0x0001
42 #define	CAPH_READ		0x0002
43 #define	CAPH_WRITE		0x0004
44 #define	CAPH_LOOKUP		0x0008
45 
46 static __inline int
47 caph_limit_stream(int fd, int flags)
48 {
49 	cap_rights_t rights;
50 	unsigned long cmds[] = { TIOCGETA, TIOCGWINSZ };
51 
52 	cap_rights_init(&rights, CAP_FCNTL, CAP_FSTAT, CAP_IOCTL);
53 
54 	if ((flags & CAPH_READ) != 0)
55 		cap_rights_set(&rights, CAP_READ);
56 	if ((flags & CAPH_WRITE) != 0)
57 		cap_rights_set(&rights, CAP_WRITE);
58 	if ((flags & CAPH_LOOKUP) != 0)
59 		cap_rights_set(&rights, CAP_LOOKUP);
60 
61 	if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
62 		if (errno == EBADF && (flags & CAPH_IGNORE_EBADF) != 0)
63 			return (0);
64 		return (-1);
65 	}
66 
67 	if (cap_ioctls_limit(fd, cmds, nitems(cmds)) < 0 && errno != ENOSYS)
68 		return (-1);
69 
70 	if (cap_fcntls_limit(fd, CAP_FCNTL_GETFL) < 0 && errno != ENOSYS)
71 		return (-1);
72 
73 	return (0);
74 }
75 
76 static __inline int
77 caph_limit_stdin(void)
78 {
79 
80 	return (caph_limit_stream(STDIN_FILENO, CAPH_READ));
81 }
82 
83 static __inline int
84 caph_limit_stderr(void)
85 {
86 
87 	return (caph_limit_stream(STDERR_FILENO, CAPH_WRITE));
88 }
89 
90 static __inline int
91 caph_limit_stdout(void)
92 {
93 
94 	return (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE));
95 }
96 
97 static __inline int
98 caph_limit_stdio(void)
99 {
100 	const int iebadf = CAPH_IGNORE_EBADF;
101 
102 	if (caph_limit_stream(STDIN_FILENO, CAPH_READ | iebadf) == -1 ||
103 	    caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | iebadf) == -1 ||
104 	    caph_limit_stream(STDERR_FILENO, CAPH_WRITE | iebadf) == -1)
105 		return (-1);
106 	return (0);
107 }
108 
109 static __inline void
110 caph_cache_tzdata(void)
111 {
112 
113 	tzset();
114 }
115 
116 static __inline void
117 caph_cache_catpages(void)
118 {
119 
120 	(void)catopen("libc", NL_CAT_LOCALE);
121 }
122 
123 #endif /* _CAPSICUM_HELPERS_H_ */
124