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
27 #ifndef _CAPSICUM_HELPERS_H_
28 #define _CAPSICUM_HELPERS_H_
29
30 #include <sys/param.h>
31 #include <sys/capsicum.h>
32 #include <sys/ioctl.h>
33
34 #include <errno.h>
35 #include <nl_types.h>
36 #include <termios.h>
37 #include <time.h>
38 #include <unistd.h>
39
40 #include <libcasper.h>
41
42 #define CAPH_IGNORE_EBADF 0x0001
43 #define CAPH_READ 0x0002
44 #define CAPH_WRITE 0x0004
45 #define CAPH_LOOKUP 0x0008
46
47 __BEGIN_DECLS
48
49 static const unsigned long caph_stream_cmds[] =
50 {
51 #ifdef TIOCGETA
52 TIOCGETA,
53 #endif
54 #ifdef TIOCGWINSZ
55 TIOCGWINSZ,
56 #endif
57 #ifdef FIODTYPE
58 FIODTYPE,
59 #endif
60 };
61 static const uint32_t caph_stream_fcntls = CAP_FCNTL_GETFL;
62
63 static __inline void
caph_stream_rights(cap_rights_t * rights,int flags)64 caph_stream_rights(cap_rights_t *rights, int flags)
65 {
66
67 cap_rights_init(rights, CAP_EVENT, CAP_FCNTL, CAP_FSTAT,
68 CAP_IOCTL, CAP_SEEK);
69
70 if ((flags & CAPH_READ) != 0)
71 cap_rights_set(rights, CAP_READ);
72 if ((flags & CAPH_WRITE) != 0)
73 cap_rights_set(rights, CAP_WRITE);
74 if ((flags & CAPH_LOOKUP) != 0)
75 cap_rights_set(rights, CAP_LOOKUP);
76 }
77
78 static __inline int
caph_limit_stream(int fd,int flags)79 caph_limit_stream(int fd, int flags)
80 {
81 cap_rights_t rights;
82
83 caph_stream_rights(&rights, flags);
84 if (cap_rights_limit(fd, &rights) < 0 && errno != ENOSYS) {
85 if (errno == EBADF && (flags & CAPH_IGNORE_EBADF) != 0)
86 return (0);
87 return (-1);
88 }
89
90 if (cap_ioctls_limit(fd, caph_stream_cmds,
91 nitems(caph_stream_cmds)) < 0 && errno != ENOSYS)
92 return (-1);
93
94 if (cap_fcntls_limit(fd, caph_stream_fcntls) < 0 && errno != ENOSYS)
95 return (-1);
96
97 return (0);
98 }
99
100 static __inline int
caph_limit_stdin(void)101 caph_limit_stdin(void)
102 {
103
104 return (caph_limit_stream(STDIN_FILENO, CAPH_READ));
105 }
106
107 static __inline int
caph_limit_stderr(void)108 caph_limit_stderr(void)
109 {
110
111 return (caph_limit_stream(STDERR_FILENO, CAPH_WRITE));
112 }
113
114 static __inline int
caph_limit_stdout(void)115 caph_limit_stdout(void)
116 {
117
118 return (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE));
119 }
120
121 static __inline int
caph_limit_stdio(void)122 caph_limit_stdio(void)
123 {
124 const int iebadf = CAPH_IGNORE_EBADF;
125
126 if (caph_limit_stream(STDIN_FILENO, CAPH_READ | iebadf) == -1 ||
127 caph_limit_stream(STDOUT_FILENO, CAPH_WRITE | iebadf) == -1 ||
128 caph_limit_stream(STDERR_FILENO, CAPH_WRITE | iebadf) == -1)
129 return (-1);
130 return (0);
131 }
132
133 static __inline void
caph_cache_tzdata(void)134 caph_cache_tzdata(void)
135 {
136 time_t delta;
137
138 tzset();
139
140 /*
141 * The tzset() function does not cache all time zones.
142 * Some functions, such as gmtime(), require a GMT time zone.
143 * The only way to cache them is to call the function directly.
144 */
145 delta = 0;
146 (void)gmtime(&delta);
147 }
148
149 static __inline void
caph_cache_catpages(void)150 caph_cache_catpages(void)
151 {
152
153 (void)catopen("libc", NL_CAT_LOCALE);
154 }
155
156 static __inline int
caph_enter(void)157 caph_enter(void)
158 {
159
160 if (cap_enter() < 0 && errno != ENOSYS)
161 return (-1);
162
163 return (0);
164 }
165
166 static __inline int
caph_rights_limit(int fd,const cap_rights_t * rights)167 caph_rights_limit(int fd, const cap_rights_t *rights)
168 {
169
170 if (cap_rights_limit(fd, rights) < 0 && errno != ENOSYS)
171 return (-1);
172
173 return (0);
174 }
175
176 static __inline int
caph_ioctls_limit(int fd,const unsigned long * cmds,size_t ncmds)177 caph_ioctls_limit(int fd, const unsigned long *cmds, size_t ncmds)
178 {
179
180 if (cap_ioctls_limit(fd, cmds, ncmds) < 0 && errno != ENOSYS)
181 return (-1);
182
183 return (0);
184 }
185
186 static __inline int
caph_fcntls_limit(int fd,uint32_t fcntlrights)187 caph_fcntls_limit(int fd, uint32_t fcntlrights)
188 {
189
190 if (cap_fcntls_limit(fd, fcntlrights) < 0 && errno != ENOSYS)
191 return (-1);
192
193 return (0);
194 }
195
196 static __inline int
caph_enter_casper(void)197 caph_enter_casper(void)
198 {
199
200 return (CASPER_SUPPORT == 0 ? 0 : caph_enter());
201 }
202
203 __END_DECLS
204
205 #endif /* _CAPSICUM_HELPERS_H_ */
206