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- /*
- * Copyright (c) Ian F. Darwin 1986-1995.
- * Software written by Ian F. Darwin and others;
- * maintained 1995-present by Christos Zoulas and others.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice immediately at the beginning of the file, without modification,
- * this list of conditions, and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
- * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- /*
- * fsmagic - magic based on filesystem info - directory, special files, etc.
- */
- #include "file.h"
- #ifndef lint
- FILE_RCSID("@(#)$File: fsmagic.c,v 1.79 2018/10/02 00:38:33 christos Exp $")
- #endif /* lint */
- #include "magic.h"
- #include <string.h>
- #ifdef HAVE_UNISTD_H
- #include <unistd.h>
- #endif
- #include <stdlib.h>
- /* Since major is a function on SVR4, we cannot use `ifndef major'. */
- #ifdef MAJOR_IN_MKDEV
- # include <sys/mkdev.h>
- # define HAVE_MAJOR
- #endif
- #ifdef MAJOR_IN_SYSMACROS
- # include <sys/sysmacros.h>
- # define HAVE_MAJOR
- #endif
- #ifdef major /* Might be defined in sys/types.h. */
- # define HAVE_MAJOR
- #endif
- #ifdef WIN32
- # define WIN32_LEAN_AND_MEAN
- # include <windows.h>
- #endif
- #ifndef HAVE_MAJOR
- # define major(dev) (((dev) >> 8) & 0xff)
- # define minor(dev) ((dev) & 0xff)
- #endif
- #undef HAVE_MAJOR
- #ifdef S_IFLNK
- private int
- bad_link(struct magic_set *ms, int err, char *buf)
- {
- int mime = ms->flags & MAGIC_MIME;
- if ((mime & MAGIC_MIME_TYPE) &&
- file_printf(ms, "inode/symlink")
- == -1)
- return -1;
- else if (!mime) {
- if (ms->flags & MAGIC_ERROR) {
- file_error(ms, err,
- "broken symbolic link to %s", buf);
- return -1;
- }
- if (file_printf(ms, "broken symbolic link to %s", buf) == -1)
- return -1;
- }
- return 1;
- }
- #endif
- private int
- handle_mime(struct magic_set *ms, int mime, const char *str)
- {
- if ((mime & MAGIC_MIME_TYPE)) {
- if (file_printf(ms, "inode/%s", str) == -1)
- return -1;
- if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms,
- "; charset=") == -1)
- return -1;
- }
- if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1)
- return -1;
- return 0;
- }
- protected int
- file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb)
- {
- int ret, did = 0;
- int mime = ms->flags & MAGIC_MIME;
- int silent = ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION);
- #ifdef S_IFLNK
- char buf[BUFSIZ+4];
- ssize_t nch;
- struct stat tstatbuf;
- #endif
- if (fn == NULL)
- return 0;
- #define COMMA (did++ ? ", " : "")
- /*
- * Fstat is cheaper but fails for files you don't have read perms on.
- * On 4.2BSD and similar systems, use lstat() to identify symlinks.
- */
- #ifdef S_IFLNK
- if ((ms->flags & MAGIC_SYMLINK) == 0)
- ret = lstat(fn, sb);
- else
- #endif
- ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
- #ifdef WIN32
- {
- HANDLE hFile = CreateFile((LPCSTR)fn, 0, FILE_SHARE_DELETE |
- FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0,
- NULL);
- if (hFile != INVALID_HANDLE_VALUE) {
- /*
- * Stat failed, but we can still open it - assume it's
- * a block device, if nothing else.
- */
- if (ret) {
- sb->st_mode = S_IFBLK;
- ret = 0;
- }
- switch (GetFileType(hFile)) {
- case FILE_TYPE_CHAR:
- sb->st_mode |= S_IFCHR;
- sb->st_mode &= ~S_IFREG;
- break;
- case FILE_TYPE_PIPE:
- sb->st_mode |= S_IFIFO;
- sb->st_mode &= ~S_IFREG;
- break;
- }
- CloseHandle(hFile);
- }
- }
- #endif
- if (ret) {
- if (ms->flags & MAGIC_ERROR) {
- file_error(ms, errno, "cannot stat `%s'", fn);
- return -1;
- }
- if (file_printf(ms, "cannot open `%s' (%s)",
- fn, strerror(errno)) == -1)
- return -1;
- return 0;
- }
- ret = 1;
- if (!mime && !silent) {
- #ifdef S_ISUID
- if (sb->st_mode & S_ISUID)
- if (file_printf(ms, "%ssetuid", COMMA) == -1)
- return -1;
- #endif
- #ifdef S_ISGID
- if (sb->st_mode & S_ISGID)
- if (file_printf(ms, "%ssetgid", COMMA) == -1)
- return -1;
- #endif
- #ifdef S_ISVTX
- if (sb->st_mode & S_ISVTX)
- if (file_printf(ms, "%ssticky", COMMA) == -1)
- return -1;
- #endif
- }
- switch (sb->st_mode & S_IFMT) {
- case S_IFDIR:
- if (mime) {
- if (handle_mime(ms, mime, "directory") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%sdirectory", COMMA) == -1)
- return -1;
- break;
- #ifdef S_IFCHR
- case S_IFCHR:
- /*
- * If -s has been specified, treat character special files
- * like ordinary files. Otherwise, just report that they
- * are block special files and go on to the next file.
- */
- if ((ms->flags & MAGIC_DEVICES) != 0) {
- ret = 0;
- break;
- }
- if (mime) {
- if (handle_mime(ms, mime, "chardevice") == -1)
- return -1;
- } else if (silent) {
- } else {
- #ifdef HAVE_STRUCT_STAT_ST_RDEV
- # ifdef dv_unit
- if (file_printf(ms, "%scharacter special (%d/%d/%d)",
- COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev),
- dv_subunit(sb->st_rdev)) == -1)
- return -1;
- # else
- if (file_printf(ms, "%scharacter special (%ld/%ld)",
- COMMA, (long)major(sb->st_rdev),
- (long)minor(sb->st_rdev)) == -1)
- return -1;
- # endif
- #else
- if (file_printf(ms, "%scharacter special", COMMA) == -1)
- return -1;
- #endif
- }
- break;
- #endif
- #ifdef S_IFBLK
- case S_IFBLK:
- /*
- * If -s has been specified, treat block special files
- * like ordinary files. Otherwise, just report that they
- * are block special files and go on to the next file.
- */
- if ((ms->flags & MAGIC_DEVICES) != 0) {
- ret = 0;
- break;
- }
- if (mime) {
- if (handle_mime(ms, mime, "blockdevice") == -1)
- return -1;
- } else if (silent) {
- } else {
- #ifdef HAVE_STRUCT_STAT_ST_RDEV
- # ifdef dv_unit
- if (file_printf(ms, "%sblock special (%d/%d/%d)",
- COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev),
- dv_subunit(sb->st_rdev)) == -1)
- return -1;
- # else
- if (file_printf(ms, "%sblock special (%ld/%ld)",
- COMMA, (long)major(sb->st_rdev),
- (long)minor(sb->st_rdev)) == -1)
- return -1;
- # endif
- #else
- if (file_printf(ms, "%sblock special", COMMA) == -1)
- return -1;
- #endif
- }
- break;
- #endif
- /* TODO add code to handle V7 MUX and Blit MUX files */
- #ifdef S_IFIFO
- case S_IFIFO:
- if((ms->flags & MAGIC_DEVICES) != 0)
- break;
- if (mime) {
- if (handle_mime(ms, mime, "fifo") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1)
- return -1;
- break;
- #endif
- #ifdef S_IFDOOR
- case S_IFDOOR:
- if (mime) {
- if (handle_mime(ms, mime, "door") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%sdoor", COMMA) == -1)
- return -1;
- break;
- #endif
- #ifdef S_IFLNK
- case S_IFLNK:
- if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
- if (ms->flags & MAGIC_ERROR) {
- file_error(ms, errno, "unreadable symlink `%s'",
- fn);
- return -1;
- }
- if (mime) {
- if (handle_mime(ms, mime, "symlink") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms,
- "%sunreadable symlink `%s' (%s)", COMMA, fn,
- strerror(errno)) == -1)
- return -1;
- break;
- }
- buf[nch] = '\0'; /* readlink(2) does not do this */
- /* If broken symlink, say so and quit early. */
- #ifdef __linux__
- /*
- * linux procfs/devfs makes symlinks like pipe:[3515864880]
- * that we can't stat their readlink output, so stat the
- * original filename instead.
- */
- if (stat(fn, &tstatbuf) < 0)
- return bad_link(ms, errno, buf);
- #else
- if (*buf == '/') {
- if (stat(buf, &tstatbuf) < 0)
- return bad_link(ms, errno, buf);
- } else {
- char *tmp;
- char buf2[BUFSIZ+BUFSIZ+4];
- if ((tmp = strrchr(fn, '/')) == NULL) {
- tmp = buf; /* in current directory anyway */
- } else {
- if (tmp - fn + 1 > BUFSIZ) {
- if (ms->flags & MAGIC_ERROR) {
- file_error(ms, 0,
- "path too long: `%s'", buf);
- return -1;
- }
- if (mime) {
- if (handle_mime(ms, mime,
- "x-path-too-long") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms,
- "%spath too long: `%s'", COMMA,
- fn) == -1)
- return -1;
- break;
- }
- /* take dir part */
- (void)strlcpy(buf2, fn, sizeof buf2);
- buf2[tmp - fn + 1] = '\0';
- /* plus (rel) link */
- (void)strlcat(buf2, buf, sizeof buf2);
- tmp = buf2;
- }
- if (stat(tmp, &tstatbuf) < 0)
- return bad_link(ms, errno, buf);
- }
- #endif
- /* Otherwise, handle it. */
- if ((ms->flags & MAGIC_SYMLINK) != 0) {
- const char *p;
- ms->flags &= MAGIC_SYMLINK;
- p = magic_file(ms, buf);
- ms->flags |= MAGIC_SYMLINK;
- if (p == NULL)
- return -1;
- } else { /* just print what it points to */
- if (mime) {
- if (handle_mime(ms, mime, "symlink") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%ssymbolic link to %s",
- COMMA, buf) == -1)
- return -1;
- }
- break;
- #endif
- #ifdef S_IFSOCK
- #ifndef __COHERENT__
- case S_IFSOCK:
- if (mime) {
- if (handle_mime(ms, mime, "socket") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%ssocket", COMMA) == -1)
- return -1;
- break;
- #endif
- #endif
- case S_IFREG:
- /*
- * regular file, check next possibility
- *
- * If stat() tells us the file has zero length, report here that
- * the file is empty, so we can skip all the work of opening and
- * reading the file.
- * But if the -s option has been given, we skip this
- * optimization, since on some systems, stat() reports zero
- * size for raw disk partitions. (If the block special device
- * really has zero length, the fact that it is empty will be
- * detected and reported correctly when we read the file.)
- */
- if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
- if (mime) {
- if (handle_mime(ms, mime, "x-empty") == -1)
- return -1;
- } else if (silent) {
- } else if (file_printf(ms, "%sempty", COMMA) == -1)
- return -1;
- break;
- }
- ret = 0;
- break;
- default:
- file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
- return -1;
- /*NOTREACHED*/
- }
- if (!silent && !mime && did && ret == 0) {
- if (file_printf(ms, " ") == -1)
- return -1;
- }
- return ret;
- }
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