fsmagic.c revision 267843
168349Sobrien/* 2133359Sobrien * Copyright (c) Ian F. Darwin 1986-1995. 3133359Sobrien * Software written by Ian F. Darwin and others; 4133359Sobrien * maintained 1995-present by Christos Zoulas and others. 5133359Sobrien * 6133359Sobrien * Redistribution and use in source and binary forms, with or without 7133359Sobrien * modification, are permitted provided that the following conditions 8133359Sobrien * are met: 9133359Sobrien * 1. Redistributions of source code must retain the above copyright 10133359Sobrien * notice immediately at the beginning of the file, without modification, 11133359Sobrien * this list of conditions, and the following disclaimer. 12133359Sobrien * 2. Redistributions in binary form must reproduce the above copyright 13133359Sobrien * notice, this list of conditions and the following disclaimer in the 14133359Sobrien * documentation and/or other materials provided with the distribution. 15133359Sobrien * 16133359Sobrien * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17133359Sobrien * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18133359Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19133359Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20133359Sobrien * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21133359Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22133359Sobrien * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23133359Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24133359Sobrien * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25133359Sobrien * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26133359Sobrien * SUCH DAMAGE. 27133359Sobrien */ 28133359Sobrien/* 2968349Sobrien * fsmagic - magic based on filesystem info - directory, special files, etc. 3068349Sobrien */ 3168349Sobrien 3268349Sobrien#include "file.h" 33191736Sobrien 34191736Sobrien#ifndef lint 35267843SdelphijFILE_RCSID("@(#)$File: fsmagic.c,v 1.73 2014/05/14 23:15:42 christos Exp $") 36191736Sobrien#endif /* lint */ 37191736Sobrien 38133359Sobrien#include "magic.h" 3968349Sobrien#include <string.h> 4068349Sobrien#ifdef HAVE_UNISTD_H 4168349Sobrien#include <unistd.h> 4268349Sobrien#endif 4368349Sobrien#include <stdlib.h> 44133359Sobrien/* Since major is a function on SVR4, we cannot use `ifndef major'. */ 4568349Sobrien#ifdef MAJOR_IN_MKDEV 4668349Sobrien# include <sys/mkdev.h> 4768349Sobrien# define HAVE_MAJOR 4868349Sobrien#endif 4968349Sobrien#ifdef MAJOR_IN_SYSMACROS 5068349Sobrien# include <sys/sysmacros.h> 5168349Sobrien# define HAVE_MAJOR 5268349Sobrien#endif 5368349Sobrien#ifdef major /* Might be defined in sys/types.h. */ 5468349Sobrien# define HAVE_MAJOR 5568349Sobrien#endif 56267843Sdelphij#ifdef WIN32 57267843Sdelphij# define WIN32_LEAN_AND_MEAN 58267843Sdelphij# include <windows.h> 59267843Sdelphij#endif 60267843Sdelphij 6168349Sobrien#ifndef HAVE_MAJOR 6268349Sobrien# define major(dev) (((dev) >> 8) & 0xff) 6368349Sobrien# define minor(dev) ((dev) & 0xff) 6468349Sobrien#endif 6568349Sobrien#undef HAVE_MAJOR 66226048Sobrien#ifdef S_IFLNK 67186690Sobrienprivate int 68186690Sobrienbad_link(struct magic_set *ms, int err, char *buf) 69186690Sobrien{ 70186690Sobrien int mime = ms->flags & MAGIC_MIME; 71186690Sobrien if ((mime & MAGIC_MIME_TYPE) && 72226048Sobrien file_printf(ms, "inode/symlink") 73186690Sobrien == -1) 74186690Sobrien return -1; 75186690Sobrien else if (!mime) { 76186690Sobrien if (ms->flags & MAGIC_ERROR) { 77226048Sobrien file_error(ms, err, 78226048Sobrien "broken symbolic link to `%s'", buf); 79186690Sobrien return -1; 80186690Sobrien } 81226048Sobrien if (file_printf(ms, "broken symbolic link to `%s'", buf) == -1) 82186690Sobrien return -1; 83186690Sobrien } 84186690Sobrien return 1; 85186690Sobrien} 86226048Sobrien#endif 87191736Sobrienprivate int 88191736Sobrienhandle_mime(struct magic_set *ms, int mime, const char *str) 89191736Sobrien{ 90191736Sobrien if ((mime & MAGIC_MIME_TYPE)) { 91226048Sobrien if (file_printf(ms, "inode/%s", str) == -1) 92191736Sobrien return -1; 93191736Sobrien if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, 94191736Sobrien "; charset=") == -1) 95191736Sobrien return -1; 96191736Sobrien } 97191736Sobrien if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1) 98191736Sobrien return -1; 99191736Sobrien return 0; 100191736Sobrien} 101191736Sobrien 102133359Sobrienprotected int 103133359Sobrienfile_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb) 10468349Sobrien{ 105267843Sdelphij int ret, did = 0; 106175296Sobrien int mime = ms->flags & MAGIC_MIME; 107133359Sobrien#ifdef S_IFLNK 108133359Sobrien char buf[BUFSIZ+4]; 109226048Sobrien ssize_t nch; 110133359Sobrien struct stat tstatbuf; 111133359Sobrien#endif 11268349Sobrien 113191736Sobrien if (ms->flags & MAGIC_APPLE) 114191736Sobrien return 0; 115133359Sobrien if (fn == NULL) 116133359Sobrien return 0; 117133359Sobrien 118267843Sdelphij#define COMMA (did++ ? ", " : "") 11968349Sobrien /* 12068349Sobrien * Fstat is cheaper but fails for files you don't have read perms on. 12168349Sobrien * On 4.2BSD and similar systems, use lstat() to identify symlinks. 12268349Sobrien */ 12368349Sobrien#ifdef S_IFLNK 124133359Sobrien if ((ms->flags & MAGIC_SYMLINK) == 0) 12568349Sobrien ret = lstat(fn, sb); 12668349Sobrien else 12768349Sobrien#endif 12868349Sobrien ret = stat(fn, sb); /* don't merge into if; see "ret =" above */ 12968349Sobrien 130267843Sdelphij#ifdef WIN32 131267843Sdelphij { 132267843Sdelphij HANDLE hFile = CreateFile(fn, 0, FILE_SHARE_DELETE | 133267843Sdelphij FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, 134267843Sdelphij NULL); 135267843Sdelphij if (hFile != INVALID_HANDLE_VALUE) { 136267843Sdelphij /* 137267843Sdelphij * Stat failed, but we can still open it - assume it's 138267843Sdelphij * a block device, if nothing else. 139267843Sdelphij */ 140267843Sdelphij if (ret) { 141267843Sdelphij sb->st_mode = S_IFBLK; 142267843Sdelphij ret = 0; 143267843Sdelphij } 144267843Sdelphij switch (GetFileType(hFile)) { 145267843Sdelphij case FILE_TYPE_CHAR: 146267843Sdelphij sb->st_mode |= S_IFCHR; 147267843Sdelphij sb->st_mode &= ~S_IFREG; 148267843Sdelphij break; 149267843Sdelphij case FILE_TYPE_PIPE: 150267843Sdelphij sb->st_mode |= S_IFIFO; 151267843Sdelphij sb->st_mode &= ~S_IFREG; 152267843Sdelphij break; 153267843Sdelphij } 154267843Sdelphij CloseHandle(hFile); 155267843Sdelphij } 156267843Sdelphij } 157267843Sdelphij#endif 158267843Sdelphij 15968349Sobrien if (ret) { 160133359Sobrien if (ms->flags & MAGIC_ERROR) { 161133359Sobrien file_error(ms, errno, "cannot stat `%s'", fn); 162133359Sobrien return -1; 163133359Sobrien } 164139368Sobrien if (file_printf(ms, "cannot open `%s' (%s)", 165133359Sobrien fn, strerror(errno)) == -1) 166133359Sobrien return -1; 167267843Sdelphij return 0; 16868349Sobrien } 16968349Sobrien 170267843Sdelphij ret = 1; 171186690Sobrien if (!mime) { 17268349Sobrien#ifdef S_ISUID 173267843Sdelphij if (sb->st_mode & S_ISUID) 174267843Sdelphij if (file_printf(ms, "%ssetuid", COMMA) == -1) 175133359Sobrien return -1; 17668349Sobrien#endif 17768349Sobrien#ifdef S_ISGID 178133359Sobrien if (sb->st_mode & S_ISGID) 179267843Sdelphij if (file_printf(ms, "%ssetgid", COMMA) == -1) 180133359Sobrien return -1; 18168349Sobrien#endif 18268349Sobrien#ifdef S_ISVTX 183133359Sobrien if (sb->st_mode & S_ISVTX) 184267843Sdelphij if (file_printf(ms, "%ssticky", COMMA) == -1) 185133359Sobrien return -1; 18668349Sobrien#endif 18768349Sobrien } 18868349Sobrien 18968349Sobrien switch (sb->st_mode & S_IFMT) { 19068349Sobrien case S_IFDIR: 191191736Sobrien if (mime) { 192226048Sobrien if (handle_mime(ms, mime, "directory") == -1) 193191736Sobrien return -1; 194267843Sdelphij } else if (file_printf(ms, "%sdirectory", COMMA) == -1) 195133359Sobrien return -1; 196267843Sdelphij break; 19768349Sobrien#ifdef S_IFCHR 19868349Sobrien case S_IFCHR: 19968349Sobrien /* 20068349Sobrien * If -s has been specified, treat character special files 20168349Sobrien * like ordinary files. Otherwise, just report that they 20268349Sobrien * are block special files and go on to the next file. 20368349Sobrien */ 204267843Sdelphij if ((ms->flags & MAGIC_DEVICES) != 0) { 205267843Sdelphij ret = 0; 20668349Sobrien break; 207267843Sdelphij } 208191736Sobrien if (mime) { 209226048Sobrien if (handle_mime(ms, mime, "chardevice") == -1) 210191736Sobrien return -1; 211191736Sobrien } else { 212267843Sdelphij#ifdef HAVE_STRUCT_STAT_ST_RDEV 21368349Sobrien# ifdef dv_unit 214267843Sdelphij if (file_printf(ms, "%scharacter special (%d/%d/%d)", 215267843Sdelphij COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 216186690Sobrien dv_subunit(sb->st_rdev)) == -1) 217186690Sobrien return -1; 21868349Sobrien# else 219267843Sdelphij if (file_printf(ms, "%scharacter special (%ld/%ld)", 220267843Sdelphij COMMA, (long)major(sb->st_rdev), 221267843Sdelphij (long)minor(sb->st_rdev)) == -1) 222186690Sobrien return -1; 22368349Sobrien# endif 22468349Sobrien#else 225267843Sdelphij if (file_printf(ms, "%scharacter special", COMMA) == -1) 226186690Sobrien return -1; 22768349Sobrien#endif 228186690Sobrien } 229267843Sdelphij break; 23068349Sobrien#endif 23168349Sobrien#ifdef S_IFBLK 23268349Sobrien case S_IFBLK: 23368349Sobrien /* 23468349Sobrien * If -s has been specified, treat block special files 23568349Sobrien * like ordinary files. Otherwise, just report that they 23668349Sobrien * are block special files and go on to the next file. 23768349Sobrien */ 238267843Sdelphij if ((ms->flags & MAGIC_DEVICES) != 0) { 239267843Sdelphij ret = 0; 24068349Sobrien break; 241267843Sdelphij } 242191736Sobrien if (mime) { 243226048Sobrien if (handle_mime(ms, mime, "blockdevice") == -1) 244191736Sobrien return -1; 245191736Sobrien } else { 246267843Sdelphij#ifdef HAVE_STRUCT_STAT_ST_RDEV 24768349Sobrien# ifdef dv_unit 248267843Sdelphij if (file_printf(ms, "%sblock special (%d/%d/%d)", 249267843Sdelphij COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev), 250267843Sdelphij dv_subunit(sb->st_rdev)) == -1) 251186690Sobrien return -1; 25268349Sobrien# else 253267843Sdelphij if (file_printf(ms, "%sblock special (%ld/%ld)", 254267843Sdelphij COMMA, (long)major(sb->st_rdev), 255267843Sdelphij (long)minor(sb->st_rdev)) == -1) 256186690Sobrien return -1; 25768349Sobrien# endif 25868349Sobrien#else 259267843Sdelphij if (file_printf(ms, "%sblock special", COMMA) == -1) 260186690Sobrien return -1; 26168349Sobrien#endif 262186690Sobrien } 263267843Sdelphij break; 26468349Sobrien#endif 26568349Sobrien /* TODO add code to handle V7 MUX and Blit MUX files */ 26668349Sobrien#ifdef S_IFIFO 26768349Sobrien case S_IFIFO: 268159764Sobrien if((ms->flags & MAGIC_DEVICES) != 0) 269159764Sobrien break; 270191736Sobrien if (mime) { 271226048Sobrien if (handle_mime(ms, mime, "fifo") == -1) 272191736Sobrien return -1; 273267843Sdelphij } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1) 274133359Sobrien return -1; 275267843Sdelphij break; 27668349Sobrien#endif 27768349Sobrien#ifdef S_IFDOOR 27868349Sobrien case S_IFDOOR: 279191736Sobrien if (mime) { 280226048Sobrien if (handle_mime(ms, mime, "door") == -1) 281191736Sobrien return -1; 282267843Sdelphij } else if (file_printf(ms, "%sdoor", COMMA) == -1) 283133359Sobrien return -1; 284267843Sdelphij break; 28568349Sobrien#endif 28668349Sobrien#ifdef S_IFLNK 28768349Sobrien case S_IFLNK: 288133359Sobrien if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) { 289133359Sobrien if (ms->flags & MAGIC_ERROR) { 290133359Sobrien file_error(ms, errno, "unreadable symlink `%s'", 291133359Sobrien fn); 292133359Sobrien return -1; 29368349Sobrien } 294191736Sobrien if (mime) { 295226048Sobrien if (handle_mime(ms, mime, "symlink") == -1) 296191736Sobrien return -1; 297191736Sobrien } else if (file_printf(ms, 298267843Sdelphij "%sunreadable symlink `%s' (%s)", COMMA, fn, 299133359Sobrien strerror(errno)) == -1) 300133359Sobrien return -1; 301267843Sdelphij break; 302133359Sobrien } 303186690Sobrien buf[nch] = '\0'; /* readlink(2) does not do this */ 30468349Sobrien 305133359Sobrien /* If broken symlink, say so and quit early. */ 306133359Sobrien if (*buf == '/') { 307186690Sobrien if (stat(buf, &tstatbuf) < 0) 308186690Sobrien return bad_link(ms, errno, buf); 309186690Sobrien } else { 310133359Sobrien char *tmp; 311133359Sobrien char buf2[BUFSIZ+BUFSIZ+4]; 31268349Sobrien 313133359Sobrien if ((tmp = strrchr(fn, '/')) == NULL) { 31468349Sobrien tmp = buf; /* in current directory anyway */ 315133359Sobrien } else { 316133359Sobrien if (tmp - fn + 1 > BUFSIZ) { 317133359Sobrien if (ms->flags & MAGIC_ERROR) { 318133359Sobrien file_error(ms, 0, 319133359Sobrien "path too long: `%s'", buf); 320133359Sobrien return -1; 321133359Sobrien } 322191736Sobrien if (mime) { 323191736Sobrien if (handle_mime(ms, mime, 324191736Sobrien "x-path-too-long") == -1) 325191736Sobrien return -1; 326191736Sobrien } else if (file_printf(ms, 327267843Sdelphij "%spath too long: `%s'", COMMA, 328267843Sdelphij fn) == -1) 329133359Sobrien return -1; 330267843Sdelphij break; 331133359Sobrien } 332191736Sobrien /* take dir part */ 333191736Sobrien (void)strlcpy(buf2, fn, sizeof buf2); 334133359Sobrien buf2[tmp - fn + 1] = '\0'; 335191736Sobrien /* plus (rel) link */ 336191736Sobrien (void)strlcat(buf2, buf, sizeof buf2); 33768349Sobrien tmp = buf2; 338133359Sobrien } 339186690Sobrien if (stat(tmp, &tstatbuf) < 0) 340186690Sobrien return bad_link(ms, errno, buf); 34168349Sobrien } 342133359Sobrien 343133359Sobrien /* Otherwise, handle it. */ 344133359Sobrien if ((ms->flags & MAGIC_SYMLINK) != 0) { 345133359Sobrien const char *p; 346133359Sobrien ms->flags &= MAGIC_SYMLINK; 347133359Sobrien p = magic_file(ms, buf); 348133359Sobrien ms->flags |= MAGIC_SYMLINK; 349267843Sdelphij if (p == NULL) 350267843Sdelphij return -1; 351133359Sobrien } else { /* just print what it points to */ 352191736Sobrien if (mime) { 353226048Sobrien if (handle_mime(ms, mime, "symlink") == -1) 354191736Sobrien return -1; 355267843Sdelphij } else if (file_printf(ms, "%ssymbolic link to `%s'", 356267843Sdelphij COMMA, buf) == -1) 357133359Sobrien return -1; 358133359Sobrien } 359267843Sdelphij break; 36068349Sobrien#endif 36168349Sobrien#ifdef S_IFSOCK 36268349Sobrien#ifndef __COHERENT__ 36368349Sobrien case S_IFSOCK: 364191736Sobrien if (mime) { 365226048Sobrien if (handle_mime(ms, mime, "socket") == -1) 366191736Sobrien return -1; 367267843Sdelphij } else if (file_printf(ms, "%ssocket", COMMA) == -1) 368133359Sobrien return -1; 369267843Sdelphij break; 37068349Sobrien#endif 37168349Sobrien#endif 37268349Sobrien case S_IFREG: 373267843Sdelphij /* 374267843Sdelphij * regular file, check next possibility 375267843Sdelphij * 376267843Sdelphij * If stat() tells us the file has zero length, report here that 377267843Sdelphij * the file is empty, so we can skip all the work of opening and 378267843Sdelphij * reading the file. 379267843Sdelphij * But if the -s option has been given, we skip this 380267843Sdelphij * optimization, since on some systems, stat() reports zero 381267843Sdelphij * size for raw disk partitions. (If the block special device 382267843Sdelphij * really has zero length, the fact that it is empty will be 383267843Sdelphij * detected and reported correctly when we read the file.) 384267843Sdelphij */ 385267843Sdelphij if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) { 386267843Sdelphij if (mime) { 387267843Sdelphij if (handle_mime(ms, mime, "x-empty") == -1) 388267843Sdelphij return -1; 389267843Sdelphij } else if (file_printf(ms, "%sempty", COMMA) == -1) 390267843Sdelphij return -1; 391267843Sdelphij break; 392267843Sdelphij } 393267843Sdelphij ret = 0; 39468349Sobrien break; 395267843Sdelphij 39668349Sobrien default: 397133359Sobrien file_error(ms, 0, "invalid mode 0%o", sb->st_mode); 398133359Sobrien return -1; 39968349Sobrien /*NOTREACHED*/ 40068349Sobrien } 40168349Sobrien 402267843Sdelphij if (!mime && did && ret == 0) { 403267843Sdelphij if (file_printf(ms, " ") == -1) 404267843Sdelphij return -1; 40568349Sobrien } 406267843Sdelphij return ret; 40768349Sobrien} 408