1 /* $NetBSD: fsmagic.c,v 1.16 2019/12/17 02:31:05 christos Exp $ */ 2 3 /* 4 * Copyright (c) Ian F. Darwin 1986-1995. 5 * Software written by Ian F. Darwin and others; 6 * maintained 1995-present by Christos Zoulas and others. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice immediately at the beginning of the file, without modification, 13 * this list of conditions, and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 /* 31 * fsmagic - magic based on filesystem info - directory, special files, etc. 32 */ 33 34 #include "file.h" 35 36 #ifndef lint 37 #if 0 38 FILE_RCSID("@(#)$File: fsmagic.c,v 1.81 2019/07/16 13:30:32 christos Exp $") 39 #else 40 __RCSID("$NetBSD: fsmagic.c,v 1.16 2019/12/17 02:31:05 christos Exp $"); 41 #endif 42 #endif /* lint */ 43 44 #include "magic.h" 45 #include <string.h> 46 #ifdef HAVE_UNISTD_H 47 #include <unistd.h> 48 #endif 49 #include <stdlib.h> 50 /* Since major is a function on SVR4, we cannot use `ifndef major'. */ 51 #ifdef MAJOR_IN_MKDEV 52 # include <sys/mkdev.h> 53 # define HAVE_MAJOR 54 #endif 55 #ifdef HAVE_SYS_SYSMACROS_H 56 # include <sys/sysmacros.h> 57 #endif 58 #ifdef MAJOR_IN_SYSMACROS 59 # define HAVE_MAJOR 60 #endif 61 #if defined(major) && !defined(HAVE_MAJOR) 62 /* Might be defined in sys/types.h. */ 63 # define HAVE_MAJOR 64 #endif 65 #ifdef WIN32 66 # define WIN32_LEAN_AND_MEAN 67 # include <windows.h> 68 #endif 69 70 #ifndef HAVE_MAJOR 71 # define major(dev) (((dev) >> 8) & 0xff) 72 # define minor(dev) ((dev) & 0xff) 73 #endif 74 #undef HAVE_MAJOR 75 #ifdef S_IFLNK 76 private int 77 bad_link(struct magic_set *ms, int err, char *buf) 78 { 79 int mime = ms->flags & MAGIC_MIME; 80 if ((mime & MAGIC_MIME_TYPE) && 81 file_printf(ms, "inode/symlink") 82 == -1) 83 return -1; 84 else if (!mime) { 85 if (ms->flags & MAGIC_ERROR) { 86 file_error(ms, err, 87 "broken symbolic link to %s", buf); 88 return -1; 89 } 90 if (file_printf(ms, "broken symbolic link to %s", buf) == -1) 91 return -1; 92 } 93 return 1; 94 } 95 #endif 96 private int 97 handle_mime(struct magic_set *ms, int mime, const char *str) 98 { 99 if ((mime & MAGIC_MIME_TYPE)) { 100 if (file_printf(ms, "inode/%s", str) == -1) 101 return -1; 102 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, 103 "; charset=") == -1) 104 return -1; 105 } 106 if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1) 107 return -1; 108 return 0; 109 } 110 111 protected int 112 file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb) 113 { 114 int ret, did = 0; 115 int mime = ms->flags & MAGIC_MIME; 116 int silent = ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION); 117 #ifdef S_IFLNK 118 char buf[BUFSIZ+4]; 119 ssize_t nch; 120 struct stat tstatbuf; 121 #endif 122 123 if (fn == NULL) 124 return 0; 125 126 #define COMMA (did++ ? ", " : "") 127 /* 128 * Fstat is cheaper but fails for files you don't have read perms on. 129 * On 4.2BSD and similar systems, use lstat() to identify symlinks. 130 */ 131 #ifdef S_IFLNK 132 if ((ms->flags & MAGIC_SYMLINK) == 0) 133 ret = lstat(fn, sb); 134 else 135 #endif 136 ret = stat(fn, sb); /* don't merge into if; see "ret =" above */ 137 138 #ifdef WIN32 139 { 140 HANDLE hFile = CreateFile((LPCSTR)fn, 0, FILE_SHARE_DELETE | 141 FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, 142 NULL); 143 if (hFile != INVALID_HANDLE_VALUE) { 144 /* 145 * Stat failed, but we can still open it - assume it's 146 * a block device, if nothing else. 147 */ 148 if (ret) { 149 sb->st_mode = S_IFBLK; 150 ret = 0; 151 } 152 switch (GetFileType(hFile)) { 153 case FILE_TYPE_CHAR: 154 sb->st_mode |= S_IFCHR; 155 sb->st_mode &= ~S_IFREG; 156 break; 157 case FILE_TYPE_PIPE: 158 sb->st_mode |= S_IFIFO; 159 sb->st_mode &= ~S_IFREG; 160 break; 161 } 162 CloseHandle(hFile); 163 } 164 } 165 #endif 166 167 if (ret) { 168 if (ms->flags & MAGIC_ERROR) { 169 file_error(ms, errno, "cannot stat `%s'", fn); 170 return -1; 171 } 172 if (file_printf(ms, "cannot open `%s' (%s)", 173 fn, strerror(errno)) == -1) 174 return -1; 175 return 0; 176 } 177 178 ret = 1; 179 if (!mime && !silent) { 180 #ifdef S_ISUID 181 if (sb->st_mode & S_ISUID) 182 if (file_printf(ms, "%ssetuid", COMMA) == -1) 183 return -1; 184 #endif 185 #ifdef S_ISGID 186 if (sb->st_mode & S_ISGID) 187 if (file_printf(ms, "%ssetgid", COMMA) == -1) 188 return -1; 189 #endif 190 #ifdef S_ISVTX 191 if (sb->st_mode & S_ISVTX) 192 if (file_printf(ms, "%ssticky", COMMA) == -1) 193 return -1; 194 #endif 195 } 196 197 switch (sb->st_mode & S_IFMT) { 198 case S_IFDIR: 199 if (mime) { 200 if (handle_mime(ms, mime, "directory") == -1) 201 return -1; 202 } else if (silent) { 203 } else if (file_printf(ms, "%sdirectory", COMMA) == -1) 204 return -1; 205 break; 206 #ifdef S_IFCHR 207 case S_IFCHR: 208 /* 209 * If -s has been specified, treat character special files 210 * like ordinary files. Otherwise, just report that they 211 * are block special files and go on to the next file. 212 */ 213 if ((ms->flags & MAGIC_DEVICES) != 0) { 214 ret = 0; 215 break; 216 } 217 if (mime) { 218 if (handle_mime(ms, mime, "chardevice") == -1) 219 return -1; 220 } else if (silent) { 221 } else { 222 #ifdef HAVE_STRUCT_STAT_ST_RDEV 223 # ifdef dv_unit 224 if (file_printf(ms, "%scharacter special (%d/%d/%d)", 225 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 226 dv_subunit(sb->st_rdev)) == -1) 227 return -1; 228 # else 229 if (file_printf(ms, "%scharacter special (%ld/%ld)", 230 COMMA, (long)major(sb->st_rdev), 231 (long)minor(sb->st_rdev)) == -1) 232 return -1; 233 # endif 234 #else 235 if (file_printf(ms, "%scharacter special", COMMA) == -1) 236 return -1; 237 #endif 238 } 239 break; 240 #endif 241 #ifdef S_IFBLK 242 case S_IFBLK: 243 /* 244 * If -s has been specified, treat block special files 245 * like ordinary files. Otherwise, just report that they 246 * are block special files and go on to the next file. 247 */ 248 if ((ms->flags & MAGIC_DEVICES) != 0) { 249 ret = 0; 250 break; 251 } 252 if (mime) { 253 if (handle_mime(ms, mime, "blockdevice") == -1) 254 return -1; 255 } else if (silent) { 256 } else { 257 #ifdef HAVE_STRUCT_STAT_ST_RDEV 258 # ifdef dv_unit 259 if (file_printf(ms, "%sblock special (%d/%d/%d)", 260 COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 261 dv_subunit(sb->st_rdev)) == -1) 262 return -1; 263 # else 264 if (file_printf(ms, "%sblock special (%ld/%ld)", 265 COMMA, (long)major(sb->st_rdev), 266 (long)minor(sb->st_rdev)) == -1) 267 return -1; 268 # endif 269 #else 270 if (file_printf(ms, "%sblock special", COMMA) == -1) 271 return -1; 272 #endif 273 } 274 break; 275 #endif 276 /* TODO add code to handle V7 MUX and Blit MUX files */ 277 #ifdef S_IFIFO 278 case S_IFIFO: 279 if((ms->flags & MAGIC_DEVICES) != 0) 280 break; 281 if (mime) { 282 if (handle_mime(ms, mime, "fifo") == -1) 283 return -1; 284 } else if (silent) { 285 } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1) 286 return -1; 287 break; 288 #endif 289 #ifdef S_IFDOOR 290 case S_IFDOOR: 291 if (mime) { 292 if (handle_mime(ms, mime, "door") == -1) 293 return -1; 294 } else if (silent) { 295 } else if (file_printf(ms, "%sdoor", COMMA) == -1) 296 return -1; 297 break; 298 #endif 299 #ifdef S_IFLNK 300 case S_IFLNK: 301 if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) { 302 if (ms->flags & MAGIC_ERROR) { 303 file_error(ms, errno, "unreadable symlink `%s'", 304 fn); 305 return -1; 306 } 307 if (mime) { 308 if (handle_mime(ms, mime, "symlink") == -1) 309 return -1; 310 } else if (silent) { 311 } else if (file_printf(ms, 312 "%sunreadable symlink `%s' (%s)", COMMA, fn, 313 strerror(errno)) == -1) 314 return -1; 315 break; 316 } 317 buf[nch] = '\0'; /* readlink(2) does not do this */ 318 319 /* If broken symlink, say so and quit early. */ 320 #ifdef __linux__ 321 /* 322 * linux procfs/devfs makes symlinks like pipe:[3515864880] 323 * that we can't stat their readlink output, so stat the 324 * original filename instead. 325 */ 326 if (stat(fn, &tstatbuf) < 0) 327 return bad_link(ms, errno, buf); 328 #else 329 if (*buf == '/') { 330 if (stat(buf, &tstatbuf) < 0) 331 return bad_link(ms, errno, buf); 332 } else { 333 char *tmp; 334 char buf2[BUFSIZ+BUFSIZ+4]; 335 336 if ((tmp = strrchr(fn, '/')) == NULL) { 337 tmp = buf; /* in current directory anyway */ 338 } else { 339 if (tmp - fn + 1 > BUFSIZ) { 340 if (ms->flags & MAGIC_ERROR) { 341 file_error(ms, 0, 342 "path too long: `%s'", buf); 343 return -1; 344 } 345 if (mime) { 346 if (handle_mime(ms, mime, 347 "x-path-too-long") == -1) 348 return -1; 349 } else if (silent) { 350 } else if (file_printf(ms, 351 "%spath too long: `%s'", COMMA, 352 fn) == -1) 353 return -1; 354 break; 355 } 356 /* take dir part */ 357 (void)strlcpy(buf2, fn, sizeof buf2); 358 buf2[tmp - fn + 1] = '\0'; 359 /* plus (rel) link */ 360 (void)strlcat(buf2, buf, sizeof buf2); 361 tmp = buf2; 362 } 363 if (stat(tmp, &tstatbuf) < 0) 364 return bad_link(ms, errno, buf); 365 } 366 #endif 367 368 /* Otherwise, handle it. */ 369 if ((ms->flags & MAGIC_SYMLINK) != 0) { 370 const char *p; 371 ms->flags &= MAGIC_SYMLINK; 372 p = magic_file(ms, buf); 373 ms->flags |= MAGIC_SYMLINK; 374 if (p == NULL) 375 return -1; 376 } else { /* just print what it points to */ 377 if (mime) { 378 if (handle_mime(ms, mime, "symlink") == -1) 379 return -1; 380 } else if (silent) { 381 } else if (file_printf(ms, "%ssymbolic link to %s", 382 COMMA, buf) == -1) 383 return -1; 384 } 385 break; 386 #endif 387 #ifdef S_IFSOCK 388 #ifndef __COHERENT__ 389 case S_IFSOCK: 390 if (mime) { 391 if (handle_mime(ms, mime, "socket") == -1) 392 return -1; 393 } else if (silent) { 394 } else if (file_printf(ms, "%ssocket", COMMA) == -1) 395 return -1; 396 break; 397 #endif 398 #endif 399 case S_IFREG: 400 /* 401 * regular file, check next possibility 402 * 403 * If stat() tells us the file has zero length, report here that 404 * the file is empty, so we can skip all the work of opening and 405 * reading the file. 406 * But if the -s option has been given, we skip this 407 * optimization, since on some systems, stat() reports zero 408 * size for raw disk partitions. (If the block special device 409 * really has zero length, the fact that it is empty will be 410 * detected and reported correctly when we read the file.) 411 */ 412 if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) { 413 if (mime) { 414 if (handle_mime(ms, mime, "x-empty") == -1) 415 return -1; 416 } else if (silent) { 417 } else if (file_printf(ms, "%sempty", COMMA) == -1) 418 return -1; 419 break; 420 } 421 ret = 0; 422 break; 423 424 default: 425 file_error(ms, 0, "invalid mode 0%o", sb->st_mode); 426 return -1; 427 /*NOTREACHED*/ 428 } 429 430 if (!silent && !mime && did && ret == 0) { 431 if (file_printf(ms, " ") == -1) 432 return -1; 433 } 434 /* 435 * If we were looking for extensions or apple (silent) it is not our 436 * job to print here, so don't count this as a match. 437 */ 438 if (ret == 1 && silent) 439 return 0; 440 return ret; 441 } 442