1 /* 2 * Copyright (c) Ian F. Darwin 1986-1995. 3 * Software written by Ian F. Darwin and others; 4 * maintained 1995-present by Christos Zoulas and others. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice immediately at the beginning of the file, without modification, 11 * this list of conditions, and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 /* 29 * fsmagic - magic based on filesystem info - directory, special files, etc. 30 */ 31 32 #include "file.h" 33 34 #ifndef lint 35 FILE_RCSID("@(#)$File: fsmagic.c,v 1.85 2022/12/26 17:31:14 christos Exp $") 36 #endif /* lint */ 37 38 #include "magic.h" 39 #include <string.h> 40 #ifdef HAVE_UNISTD_H 41 #include <unistd.h> 42 #endif 43 #include <stdlib.h> 44 /* Since major is a function on SVR4, we cannot use `ifndef major'. */ 45 #ifdef MAJOR_IN_MKDEV 46 # include <sys/mkdev.h> 47 # define HAVE_MAJOR 48 #endif 49 #ifdef HAVE_SYS_SYSMACROS_H 50 # include <sys/sysmacros.h> 51 #endif 52 #ifdef MAJOR_IN_SYSMACROS 53 # define HAVE_MAJOR 54 #endif 55 #if defined(major) && !defined(HAVE_MAJOR) 56 /* Might be defined in sys/types.h. */ 57 # define HAVE_MAJOR 58 #endif 59 #ifdef WIN32 60 # define WIN32_LEAN_AND_MEAN 61 # include <windows.h> 62 #endif 63 64 #ifndef HAVE_MAJOR 65 # define major(dev) (((dev) >> 8) & 0xff) 66 # define minor(dev) ((dev) & 0xff) 67 #endif 68 #undef HAVE_MAJOR 69 #ifdef S_IFLNK 70 file_private int 71 bad_link(struct magic_set *ms, int err, char *buf) 72 { 73 int mime = ms->flags & MAGIC_MIME; 74 if ((mime & MAGIC_MIME_TYPE) && 75 file_printf(ms, "inode/symlink") 76 == -1) 77 return -1; 78 else if (!mime) { 79 if (ms->flags & MAGIC_ERROR) { 80 file_error(ms, err, 81 "broken symbolic link to %s", buf); 82 return -1; 83 } 84 if (file_printf(ms, "broken symbolic link to %s", buf) == -1) 85 return -1; 86 } 87 return 1; 88 } 89 #endif 90 file_private int 91 handle_mime(struct magic_set *ms, int mime, const char *str) 92 { 93 if ((mime & MAGIC_MIME_TYPE)) { 94 if (file_printf(ms, "inode/%s", str) == -1) 95 return -1; 96 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, 97 "; charset=") == -1) 98 return -1; 99 } 100 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1) 101 return -1; 102 return 0; 103 } 104 105 file_protected int 106 file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb) 107 { 108 int ret, did = 0; 109 int mime = ms->flags & MAGIC_MIME; 110 int silent = ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION); 111 #ifdef S_IFLNK 112 char buf[BUFSIZ+4]; 113 ssize_t nch; 114 struct stat tstatbuf; 115 #endif 116 117 if (fn == NULL) 118 return 0; 119 120 #define COMMA (did++ ? ", " : "") 121 /* 122 * Fstat is cheaper but fails for files you don't have read perms on. 123 * On 4.2BSD and similar systems, use lstat() to identify symlinks. 124 */ 125 #ifdef S_IFLNK 126 if ((ms->flags & MAGIC_SYMLINK) == 0) 127 ret = lstat(fn, sb); 128 else 129 #endif 130 ret = stat(fn, sb); /* don't merge into if; see "ret =" above */ 131 132 #ifdef WIN32 133 { 134 HANDLE hFile = CreateFile((LPCSTR)fn, 0, FILE_SHARE_DELETE | 135 FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, 136 NULL); 137 if (hFile != INVALID_HANDLE_VALUE) { 138 /* 139 * Stat failed, but we can still open it - assume it's 140 * a block device, if nothing else. 141 */ 142 if (ret) { 143 sb->st_mode = S_IFBLK; 144 ret = 0; 145 } 146 switch (GetFileType(hFile)) { 147 case FILE_TYPE_CHAR: 148 sb->st_mode |= S_IFCHR; 149 sb->st_mode &= ~S_IFREG; 150 break; 151 case FILE_TYPE_PIPE: 152 sb->st_mode |= S_IFIFO; 153 sb->st_mode &= ~S_IFREG; 154 break; 155 } 156 CloseHandle(hFile); 157 } 158 } 159 #endif 160 161 if (ret) { 162 if (ms->flags & MAGIC_ERROR) { 163 file_error(ms, errno, "cannot stat `%s'", fn); 164 return -1; 165 } 166 if (file_printf(ms, "cannot open `%s' (%s)", 167 fn, strerror(errno)) == -1) 168 return -1; 169 return 0; 170 } 171 172 ret = 1; 173 if (!mime && !silent) { 174 #ifdef S_ISUID 175 if (sb->st_mode & S_ISUID) 176 if (file_printf(ms, "%ssetuid", COMMA) == -1) 177 return -1; 178 #endif 179 #ifdef S_ISGID 180 if (sb->st_mode & S_ISGID) 181 if (file_printf(ms, "%ssetgid", COMMA) == -1) 182 return -1; 183 #endif 184 #ifdef S_ISVTX 185 if (sb->st_mode & S_ISVTX) 186 if (file_printf(ms, "%ssticky", COMMA) == -1) 187 return -1; 188 #endif 189 } 190 191 switch (sb->st_mode & S_IFMT) { 192 case S_IFDIR: 193 if (mime) { 194 if (handle_mime(ms, mime, "directory") == -1) 195 return -1; 196 } else if (silent) { 197 } else if (file_printf(ms, "%sdirectory", COMMA) == -1) 198 return -1; 199 break; 200 #ifdef S_IFCHR 201 case S_IFCHR: 202 /* 203 * If -s has been specified, treat character special files 204 * like ordinary files. Otherwise, just report that they 205 * are block special files and go on to the next file. 206 */ 207 if ((ms->flags & MAGIC_DEVICES) != 0) { 208 ret = 0; 209 break; 210 } 211 if (mime) { 212 if (handle_mime(ms, mime, "chardevice") == -1) 213 return -1; 214 } else if (silent) { 215 } else { 216 #ifdef HAVE_STRUCT_STAT_ST_RDEV 217 # ifdef dv_unit 218 if (file_printf(ms, "%scharacter special (%d/%d/%d)", 219 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 220 dv_subunit(sb->st_rdev)) == -1) 221 return -1; 222 # else 223 if (file_printf(ms, "%scharacter special (%ld/%ld)", 224 COMMA, (long)major(sb->st_rdev), 225 (long)minor(sb->st_rdev)) == -1) 226 return -1; 227 # endif 228 #else 229 if (file_printf(ms, "%scharacter special", COMMA) == -1) 230 return -1; 231 #endif 232 } 233 break; 234 #endif 235 #ifdef S_IFBLK 236 case S_IFBLK: 237 /* 238 * If -s has been specified, treat block special files 239 * like ordinary files. Otherwise, just report that they 240 * are block special files and go on to the next file. 241 */ 242 if ((ms->flags & MAGIC_DEVICES) != 0) { 243 ret = 0; 244 break; 245 } 246 if (mime) { 247 if (handle_mime(ms, mime, "blockdevice") == -1) 248 return -1; 249 } else if (silent) { 250 } else { 251 #ifdef HAVE_STRUCT_STAT_ST_RDEV 252 # ifdef dv_unit 253 if (file_printf(ms, "%sblock special (%d/%d/%d)", 254 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 255 dv_subunit(sb->st_rdev)) == -1) 256 return -1; 257 # else 258 if (file_printf(ms, "%sblock special (%ld/%ld)", 259 COMMA, (long)major(sb->st_rdev), 260 (long)minor(sb->st_rdev)) == -1) 261 return -1; 262 # endif 263 #else 264 if (file_printf(ms, "%sblock special", COMMA) == -1) 265 return -1; 266 #endif 267 } 268 break; 269 #endif 270 /* TODO add code to handle V7 MUX and Blit MUX files */ 271 #ifdef S_IFIFO 272 case S_IFIFO: 273 if((ms->flags & MAGIC_DEVICES) != 0) 274 break; 275 if (mime) { 276 if (handle_mime(ms, mime, "fifo") == -1) 277 return -1; 278 } else if (silent) { 279 } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1) 280 return -1; 281 break; 282 #endif 283 #ifdef S_IFDOOR 284 case S_IFDOOR: 285 if (mime) { 286 if (handle_mime(ms, mime, "door") == -1) 287 return -1; 288 } else if (silent) { 289 } else if (file_printf(ms, "%sdoor", COMMA) == -1) 290 return -1; 291 break; 292 #endif 293 #ifdef S_IFLNK 294 case S_IFLNK: 295 if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) { 296 if (ms->flags & MAGIC_ERROR) { 297 file_error(ms, errno, "unreadable symlink `%s'", 298 fn); 299 return -1; 300 } 301 if (mime) { 302 if (handle_mime(ms, mime, "symlink") == -1) 303 return -1; 304 } else if (silent) { 305 } else if (file_printf(ms, 306 "%sunreadable symlink `%s' (%s)", COMMA, fn, 307 strerror(errno)) == -1) 308 return -1; 309 break; 310 } 311 buf[nch] = '\0'; /* readlink(2) does not do this */ 312 313 /* If broken symlink, say so and quit early. */ 314 #ifdef __linux__ 315 /* 316 * linux procfs/devfs makes symlinks like pipe:[3515864880] 317 * that we can't stat their readlink output, so stat the 318 * original filename instead. 319 */ 320 if (stat(fn, &tstatbuf) < 0) 321 return bad_link(ms, errno, buf); 322 #else 323 if (*buf == '/') { 324 if (stat(buf, &tstatbuf) < 0) 325 return bad_link(ms, errno, buf); 326 } else { 327 char *tmp; 328 char buf2[BUFSIZ+BUFSIZ+4]; 329 330 if ((tmp = CCAST(char *, strrchr(fn, '/'))) == NULL) { 331 tmp = buf; /* in current directory anyway */ 332 } else { 333 if (tmp - fn + 1 > BUFSIZ) { 334 if (ms->flags & MAGIC_ERROR) { 335 file_error(ms, 0, 336 "path too long: `%s'", buf); 337 return -1; 338 } 339 if (mime) { 340 if (handle_mime(ms, mime, 341 "x-path-too-long") == -1) 342 return -1; 343 } else if (silent) { 344 } else if (file_printf(ms, 345 "%spath too long: `%s'", COMMA, 346 fn) == -1) 347 return -1; 348 break; 349 } 350 /* take dir part */ 351 (void)strlcpy(buf2, fn, sizeof buf2); 352 buf2[tmp - fn + 1] = '\0'; 353 /* plus (rel) link */ 354 (void)strlcat(buf2, buf, sizeof buf2); 355 tmp = buf2; 356 } 357 if (stat(tmp, &tstatbuf) < 0) 358 return bad_link(ms, errno, buf); 359 } 360 #endif 361 362 /* Otherwise, handle it. */ 363 if ((ms->flags & MAGIC_SYMLINK) != 0) { 364 const char *p; 365 ms->flags &= MAGIC_SYMLINK; 366 p = magic_file(ms, buf); 367 ms->flags |= MAGIC_SYMLINK; 368 if (p == NULL) 369 return -1; 370 } else { /* just print what it points to */ 371 if (mime) { 372 if (handle_mime(ms, mime, "symlink") == -1) 373 return -1; 374 } else if (silent) { 375 } else if (file_printf(ms, "%ssymbolic link to %s", 376 COMMA, buf) == -1) 377 return -1; 378 } 379 break; 380 #endif 381 #ifdef S_IFSOCK 382 #ifndef __COHERENT__ 383 case S_IFSOCK: 384 if (mime) { 385 if (handle_mime(ms, mime, "socket") == -1) 386 return -1; 387 } else if (silent) { 388 } else if (file_printf(ms, "%ssocket", COMMA) == -1) 389 return -1; 390 break; 391 #endif 392 #endif 393 case S_IFREG: 394 /* 395 * regular file, check next possibility 396 * 397 * If stat() tells us the file has zero length, report here that 398 * the file is empty, so we can skip all the work of opening and 399 * reading the file. 400 * But if the -s option has been given, we skip this 401 * optimization, since on some systems, stat() reports zero 402 * size for raw disk partitions. (If the block special device 403 * really has zero length, the fact that it is empty will be 404 * detected and reported correctly when we read the file.) 405 */ 406 if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) { 407 if (mime) { 408 if (handle_mime(ms, mime, "x-empty") == -1) 409 return -1; 410 } else if (silent) { 411 } else if (file_printf(ms, "%sempty", COMMA) == -1) 412 return -1; 413 break; 414 } 415 ret = 0; 416 break; 417 418 default: 419 file_error(ms, 0, "invalid mode 0%o", sb->st_mode); 420 return -1; 421 /*NOTREACHED*/ 422 } 423 424 if (!silent && !mime && did && ret == 0) { 425 if (file_printf(ms, " ") == -1) 426 return -1; 427 } 428 /* 429 * If we were looking for extensions or apple (silent) it is not our 430 * job to print here, so don't count this as a match. 431 */ 432 if (ret == 1 && silent) 433 return 0; 434 return ret; 435 } 436