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 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 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 101 caph_limit_stdin(void) 102 { 103 104 return (caph_limit_stream(STDIN_FILENO, CAPH_READ)); 105 } 106 107 static __inline int 108 caph_limit_stderr(void) 109 { 110 111 return (caph_limit_stream(STDERR_FILENO, CAPH_WRITE)); 112 } 113 114 static __inline int 115 caph_limit_stdout(void) 116 { 117 118 return (caph_limit_stream(STDOUT_FILENO, CAPH_WRITE)); 119 } 120 121 static __inline int 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 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 150 caph_cache_catpages(void) 151 { 152 153 (void)catopen("libc", NL_CAT_LOCALE); 154 } 155 156 static __inline int 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 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 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 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 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