/* $OpenBSD: fsmagic.c,v 1.13 2009/04/24 18:54:34 chl Exp $ */ /* * 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" #include "magic.h" #include #ifdef HAVE_UNISTD_H #include #endif #include #include /* Since major is a function on SVR4, we cannot use `ifndef major'. */ #ifdef MAJOR_IN_MKDEV # include # define HAVE_MAJOR #endif #ifdef MAJOR_IN_SYSMACROS # include # define HAVE_MAJOR #endif #ifdef major /* Might be defined in sys/types.h. */ # define HAVE_MAJOR #endif #ifndef HAVE_MAJOR # define major(dev) (((dev) >> 8) & 0xff) # define minor(dev) ((dev) & 0xff) #endif #undef HAVE_MAJOR #ifndef lint FILE_RCSID("@(#)$Id: fsmagic.c,v 1.13 2009/04/24 18:54:34 chl Exp $") #endif /* lint */ private int bad_link(struct magic_set *ms, int err, char *buf) { char *errfmt; if (err == ELOOP) errfmt = "symbolic link in a loop"; else errfmt = "broken symbolic link to `%s'"; if (ms->flags & MAGIC_ERROR) { file_error(ms, err, errfmt, buf); return -1; } if (file_printf(ms, errfmt, buf) == -1) return -1; return 1; } protected int file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb) { int ret = 0; int mime = ms->flags & MAGIC_MIME; #ifdef S_IFLNK char buf[BUFSIZ+4]; int nch; struct stat tstatbuf; #endif if (fn == NULL) return 0; /* * 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 */ 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 1; } if (mime) { if ((sb->st_mode & S_IFMT) != S_IFREG) { if ((mime & MAGIC_MIME_TYPE) && file_printf(ms, "application/x-not-regular-file") == -1) return -1; return 1; } } else { #ifdef S_ISUID if (sb->st_mode & S_ISUID) if (file_printf(ms, "setuid ") == -1) return -1; #endif #ifdef S_ISGID if (sb->st_mode & S_ISGID) if (file_printf(ms, "setgid ") == -1) return -1; #endif #ifdef S_ISVTX if (sb->st_mode & S_ISVTX) if (file_printf(ms, "sticky ") == -1) return -1; #endif } switch (sb->st_mode & S_IFMT) { case S_IFDIR: if (file_printf(ms, "directory") == -1) return -1; return 1; #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) break; #ifdef HAVE_STAT_ST_RDEV # ifdef dv_unit if (file_printf(ms, "character special (%d/%d/%d)", major(sb->st_rdev), dv_unit(sb->st_rdev), dv_subunit(sb->st_rdev)) == -1) return -1; # else if (file_printf(ms, "character special (%ld/%ld)", (long) major(sb->st_rdev), (long) minor(sb->st_rdev)) == -1) return -1; # endif #else if (file_printf(ms, "character special") == -1) return -1; #endif return 1; #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) break; #ifdef HAVE_STAT_ST_RDEV # ifdef dv_unit if (file_printf(ms, "block special (%d/%d/%d)", major(sb->st_rdev), dv_unit(sb->st_rdev), dv_subunit(sb->st_rdev)) == -1) return -1; # else if (file_printf(ms, "block special (%ld/%ld)", (long)major(sb->st_rdev), (long)minor(sb->st_rdev)) == -1) return -1; # endif #else if (file_printf(ms, "block special") == -1) return -1; #endif return 1; #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 (file_printf(ms, "fifo (named pipe)") == -1) return -1; return 1; #endif #ifdef S_IFDOOR case S_IFDOOR: if (file_printf(ms, "door") == -1) return -1; return 1; #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 (file_printf(ms, "unreadable symlink `%s' (%s)", fn, strerror(errno)) == -1) return -1; return 1; } buf[nch] = '\0'; /* readlink(2) does not do this */ /* If broken symlink, say so and quit early. */ 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 (file_printf(ms, "path too long: `%s'", fn) == -1) return -1; return 1; } (void)strlcpy(buf2, fn, sizeof buf2); /* take dir part */ buf2[tmp - fn + 1] = '\0'; (void)strlcat(buf2, buf, sizeof buf2); /* plus (rel) link */ tmp = buf2; } if (stat(tmp, &tstatbuf) < 0) return bad_link(ms, errno, buf); } /* 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; return p != NULL ? 1 : -1; } else { /* just print what it points to */ if (file_printf(ms, "symbolic link to `%s'", buf) == -1) return -1; } return 1; #endif #ifdef S_IFSOCK #ifndef __COHERENT__ case S_IFSOCK: if (file_printf(ms, "socket") == -1) return -1; return 1; #endif #endif case S_IFREG: break; default: file_error(ms, 0, "invalid mode 0%o", sb->st_mode); return -1; /*NOTREACHED*/ } /* * 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 || (mime & MAGIC_MIME_TYPE)) && file_printf(ms, mime ? "application/x-empty" : "empty") == -1) return -1; return 1; } return 0; }