1 /*-
2 * Copyright (c) 2016 Mariusz Zaborski <[email protected]>
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 #include <sys/ioctl.h>
35
36 #include <errno.h>
37 #include <nl_types.h>
38 #include <termios.h>
39 #include <time.h>
40 #include <unistd.h>
41
42 #include <libcasper.h>
43
44 #define CAPH_IGNORE_EBADF 0x0001
45 #define CAPH_READ 0x0002
46 #define CAPH_WRITE 0x0004
47 #define CAPH_LOOKUP 0x0008
48
49 __BEGIN_DECLS
50
51 static const unsigned long caph_stream_cmds[] =
52 {
53 #ifdef TIOCGETA
54 TIOCGETA,
55 #endif
56 #ifdef TIOCGWINSZ
57 TIOCGWINSZ,
58 #endif
59 #ifdef FIODTYPE
60 FIODTYPE,
61 #endif
62 };
63 static const uint32_t caph_stream_fcntls = CAP_FCNTL_GETFL;
64
65 static __inline void
caph_stream_rights(cap_rights_t * rights,int flags)66 caph_stream_rights(cap_rights_t *rights, int flags)
67 {
68
69 cap_rights_init(rights, CAP_EVENT, CAP_FCNTL, CAP_FSTAT,
70 CAP_IOCTL, CAP_SEEK);
71
72 if ((flags & CAPH_READ) != 0)
73 cap_rights_set(rights, CAP_READ);
74 if ((flags & CAPH_WRITE) != 0)
75 cap_rights_set(rights, CAP_WRITE);
76 if ((flags & CAPH_LOOKUP) != 0)
77 cap_rights_set(rights, CAP_LOOKUP);
78 }
79
80 static __inline int
caph_limit_stream(int fd,int flags)81 caph_limit_stream(int fd, int flags)
82 {
83 cap_rights_t rights;
84
85 caph_stream_rights(&rights, flags);
86 if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
87 if (errno == EBADF && (flags & CAPH_IGNORE_EBADF) != 0)
88 return (0);
89 return (-1);
90 }
91
92 if (cap_ioctls_limit(fd, caph_stream_cmds,
93 nitems(caph_stream_cmds)) < 0 && errno != ENOSYS)
94 return (-1);
95
96 if (cap_fcntls_limit(fd, caph_stream_fcntls) < 0 && errno != ENOSYS)
97 return (-1);
98
99 return (0);
100 }
101
102 static __inline int
caph_limit_stdin(void)103 caph_limit_stdin(void)
104 {
105
106 return (caph_limit_stream(STDIN_FILENO, CAPH_READ));
107 }
108
109 static __inline int
caph_limit_stderr(void)110 caph_limit_stderr(void)
111 {
112
113 return (caph_limit_stream(STDERR_FILENO, CAPH_WRITE));
114 }
115
116 static __inline int
caph_limit_stdout(void)117 caph_limit_stdout(void)
118 {
119
120 return (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE));
121 }
122
123 static __inline int
caph_limit_stdio(void)124 caph_limit_stdio(void)
125 {
126 const int iebadf = CAPH_IGNORE_EBADF;
127
128 if (caph_limit_stream(STDIN_FILENO, CAPH_READ | iebadf) == -1 ||
129 caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | iebadf) == -1 ||
130 caph_limit_stream(STDERR_FILENO, CAPH_WRITE | iebadf) == -1)
131 return (-1);
132 return (0);
133 }
134
135 static __inline void
caph_cache_tzdata(void)136 caph_cache_tzdata(void)
137 {
138
139 tzset();
140 }
141
142 static __inline void
caph_cache_catpages(void)143 caph_cache_catpages(void)
144 {
145
146 (void)catopen("libc", NL_CAT_LOCALE);
147 }
148
149 static __inline int
caph_enter(void)150 caph_enter(void)
151 {
152
153 if (cap_enter() < 0 && errno != ENOSYS)
154 return (-1);
155
156 return (0);
157 }
158
159 static __inline int
caph_rights_limit(int fd,const cap_rights_t * rights)160 caph_rights_limit(int fd, const cap_rights_t *rights)
161 {
162
163 if (cap_rights_limit(fd, rights) < 0 && errno != ENOSYS)
164 return (-1);
165
166 return (0);
167 }
168
169 static __inline int
caph_ioctls_limit(int fd,const unsigned long * cmds,size_t ncmds)170 caph_ioctls_limit(int fd, const unsigned long *cmds, size_t ncmds)
171 {
172
173 if (cap_ioctls_limit(fd, cmds, ncmds) < 0 && errno != ENOSYS)
174 return (-1);
175
176 return (0);
177 }
178
179 static __inline int
caph_fcntls_limit(int fd,uint32_t fcntlrights)180 caph_fcntls_limit(int fd, uint32_t fcntlrights)
181 {
182
183 if (cap_fcntls_limit(fd, fcntlrights) < 0 && errno != ENOSYS)
184 return (-1);
185
186 return (0);
187 }
188
189 static __inline int
caph_enter_casper(void)190 caph_enter_casper(void)
191 {
192
193 return (CASPER_SUPPORT == 0 ? 0 : caph_enter());
194 }
195
196 __END_DECLS
197
198 #endif /* _CAPSICUM_HELPERS_H_ */
199