Annotation of src/usr.bin/file/fsmagic.c, Revision 1.14
1.14 ! deraadt 1: /* $OpenBSD: fsmagic.c,v 1.13 2009/04/24 18:54:34 chl Exp $ */
1.1 deraadt 2: /*
1.7 ian 3: * Copyright (c) Ian F. Darwin 1986-1995.
4: * Software written by Ian F. Darwin and others;
5: * maintained 1995-present by Christos Zoulas and others.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice immediately at the beginning of the file, without modification,
12: * this list of conditions, and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21: * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
1.1 deraadt 28: */
1.10 tedu 29: /*
30: * fsmagic - magic based on filesystem info - directory, special files, etc.
31: */
1.1 deraadt 32:
1.10 tedu 33: #include "file.h"
34: #include "magic.h"
1.1 deraadt 35: #include <string.h>
1.10 tedu 36: #ifdef HAVE_UNISTD_H
1.1 deraadt 37: #include <unistd.h>
1.10 tedu 38: #endif
1.1 deraadt 39: #include <stdlib.h>
1.10 tedu 40: #include <sys/stat.h>
41: /* Since major is a function on SVR4, we cannot use `ifndef major'. */
42: #ifdef MAJOR_IN_MKDEV
43: # include <sys/mkdev.h>
44: # define HAVE_MAJOR
45: #endif
46: #ifdef MAJOR_IN_SYSMACROS
47: # include <sys/sysmacros.h>
48: # define HAVE_MAJOR
49: #endif
50: #ifdef major /* Might be defined in sys/types.h. */
51: # define HAVE_MAJOR
1.3 millert 52: #endif
1.10 tedu 53:
54: #ifndef HAVE_MAJOR
55: # define major(dev) (((dev) >> 8) & 0xff)
56: # define minor(dev) ((dev) & 0xff)
1.1 deraadt 57: #endif
1.10 tedu 58: #undef HAVE_MAJOR
1.1 deraadt 59:
1.13 chl 60: private int
61: bad_link(struct magic_set *ms, int err, char *buf)
62: {
63: char *errfmt;
64: if (err == ELOOP)
65: errfmt = "symbolic link in a loop";
66: else
67: errfmt = "broken symbolic link to `%s'";
68: if (ms->flags & MAGIC_ERROR) {
69: file_error(ms, err, errfmt, buf);
70: return -1;
71: }
72: if (file_printf(ms, errfmt, buf) == -1)
73: return -1;
74: return 1;
75: }
76:
1.10 tedu 77: protected int
78: file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb)
1.1 deraadt 79: {
80: int ret = 0;
1.13 chl 81: int mime = ms->flags & MAGIC_MIME;
1.10 tedu 82: #ifdef S_IFLNK
83: char buf[BUFSIZ+4];
84: int nch;
85: struct stat tstatbuf;
86: #endif
87:
88: if (fn == NULL)
89: return 0;
1.1 deraadt 90:
91: /*
92: * Fstat is cheaper but fails for files you don't have read perms on.
93: * On 4.2BSD and similar systems, use lstat() to identify symlinks.
94: */
95: #ifdef S_IFLNK
1.10 tedu 96: if ((ms->flags & MAGIC_SYMLINK) == 0)
1.1 deraadt 97: ret = lstat(fn, sb);
98: else
99: #endif
100: ret = stat(fn, sb); /* don't merge into if; see "ret =" above */
101:
102: if (ret) {
1.10 tedu 103: if (ms->flags & MAGIC_ERROR) {
104: file_error(ms, errno, "cannot stat `%s'", fn);
105: return -1;
106: }
1.12 chl 107: if (file_printf(ms, "cannot open `%s' (%s)",
108: fn, strerror(errno)) == -1)
1.10 tedu 109: return -1;
1.1 deraadt 110: return 1;
111: }
112:
1.13 chl 113: if (mime) {
1.10 tedu 114: if ((sb->st_mode & S_IFMT) != S_IFREG) {
1.13 chl 115: if ((mime & MAGIC_MIME_TYPE) &&
116: file_printf(ms, "application/x-not-regular-file")
1.10 tedu 117: == -1)
1.13 chl 118: return -1;
1.10 tedu 119: return 1;
120: }
121: }
122: else {
123: #ifdef S_ISUID
124: if (sb->st_mode & S_ISUID)
125: if (file_printf(ms, "setuid ") == -1)
126: return -1;
127: #endif
128: #ifdef S_ISGID
129: if (sb->st_mode & S_ISGID)
130: if (file_printf(ms, "setgid ") == -1)
131: return -1;
132: #endif
133: #ifdef S_ISVTX
134: if (sb->st_mode & S_ISVTX)
135: if (file_printf(ms, "sticky ") == -1)
136: return -1;
137: #endif
138: }
1.1 deraadt 139:
140: switch (sb->st_mode & S_IFMT) {
141: case S_IFDIR:
1.10 tedu 142: if (file_printf(ms, "directory") == -1)
143: return -1;
1.1 deraadt 144: return 1;
1.10 tedu 145: #ifdef S_IFCHR
1.1 deraadt 146: case S_IFCHR:
1.10 tedu 147: /*
148: * If -s has been specified, treat character special files
149: * like ordinary files. Otherwise, just report that they
150: * are block special files and go on to the next file.
151: */
152: if ((ms->flags & MAGIC_DEVICES) != 0)
153: break;
1.13 chl 154: #ifdef HAVE_STAT_ST_RDEV
1.10 tedu 155: # ifdef dv_unit
156: if (file_printf(ms, "character special (%d/%d/%d)",
157: major(sb->st_rdev), dv_unit(sb->st_rdev),
158: dv_subunit(sb->st_rdev)) == -1)
159: return -1;
160: # else
161: if (file_printf(ms, "character special (%ld/%ld)",
162: (long) major(sb->st_rdev), (long) minor(sb->st_rdev)) == -1)
163: return -1;
164: # endif
165: #else
166: if (file_printf(ms, "character special") == -1)
167: return -1;
168: #endif
1.1 deraadt 169: return 1;
1.10 tedu 170: #endif
171: #ifdef S_IFBLK
1.1 deraadt 172: case S_IFBLK:
1.10 tedu 173: /*
174: * If -s has been specified, treat block special files
175: * like ordinary files. Otherwise, just report that they
176: * are block special files and go on to the next file.
177: */
178: if ((ms->flags & MAGIC_DEVICES) != 0)
179: break;
1.13 chl 180: #ifdef HAVE_STAT_ST_RDEV
1.10 tedu 181: # ifdef dv_unit
182: if (file_printf(ms, "block special (%d/%d/%d)",
183: major(sb->st_rdev), dv_unit(sb->st_rdev),
184: dv_subunit(sb->st_rdev)) == -1)
185: return -1;
186: # else
187: if (file_printf(ms, "block special (%ld/%ld)",
188: (long)major(sb->st_rdev), (long)minor(sb->st_rdev)) == -1)
189: return -1;
190: # endif
191: #else
192: if (file_printf(ms, "block special") == -1)
193: return -1;
194: #endif
1.1 deraadt 195: return 1;
1.10 tedu 196: #endif
1.1 deraadt 197: /* TODO add code to handle V7 MUX and Blit MUX files */
198: #ifdef S_IFIFO
199: case S_IFIFO:
1.12 chl 200: if((ms->flags & MAGIC_DEVICES) != 0)
201: break;
1.10 tedu 202: if (file_printf(ms, "fifo (named pipe)") == -1)
203: return -1;
204: return 1;
205: #endif
206: #ifdef S_IFDOOR
207: case S_IFDOOR:
208: if (file_printf(ms, "door") == -1)
209: return -1;
1.1 deraadt 210: return 1;
211: #endif
212: #ifdef S_IFLNK
213: case S_IFLNK:
1.10 tedu 214: if ((nch = readlink(fn, buf, BUFSIZ-1)) <= 0) {
215: if (ms->flags & MAGIC_ERROR) {
216: file_error(ms, errno, "unreadable symlink `%s'",
217: fn);
218: return -1;
1.1 deraadt 219: }
1.10 tedu 220: if (file_printf(ms,
221: "unreadable symlink `%s' (%s)", fn,
222: strerror(errno)) == -1)
223: return -1;
224: return 1;
225: }
1.13 chl 226: buf[nch] = '\0'; /* readlink(2) does not do this */
1.1 deraadt 227:
1.10 tedu 228: /* If broken symlink, say so and quit early. */
229: if (*buf == '/') {
1.13 chl 230: if (stat(buf, &tstatbuf) < 0)
231: return bad_link(ms, errno, buf);
232: } else {
1.10 tedu 233: char *tmp;
234: char buf2[BUFSIZ+BUFSIZ+4];
1.1 deraadt 235:
1.10 tedu 236: if ((tmp = strrchr(fn, '/')) == NULL) {
1.1 deraadt 237: tmp = buf; /* in current directory anyway */
1.10 tedu 238: } else {
239: if (tmp - fn + 1 > BUFSIZ) {
240: if (ms->flags & MAGIC_ERROR) {
241: file_error(ms, 0,
242: "path too long: `%s'", buf);
243: return -1;
244: }
245: if (file_printf(ms,
246: "path too long: `%s'", fn) == -1)
247: return -1;
248: return 1;
249: }
250: (void)strlcpy(buf2, fn, sizeof buf2); /* take dir part */
251: buf2[tmp - fn + 1] = '\0';
252: (void)strlcat(buf2, buf, sizeof buf2); /* plus (rel) link */
1.1 deraadt 253: tmp = buf2;
1.10 tedu 254: }
1.13 chl 255: if (stat(tmp, &tstatbuf) < 0)
256: return bad_link(ms, errno, buf);
1.10 tedu 257: }
1.1 deraadt 258:
1.10 tedu 259: /* Otherwise, handle it. */
260: if ((ms->flags & MAGIC_SYMLINK) != 0) {
261: const char *p;
262: ms->flags &= MAGIC_SYMLINK;
263: p = magic_file(ms, buf);
264: ms->flags |= MAGIC_SYMLINK;
265: return p != NULL ? 1 : -1;
266: } else { /* just print what it points to */
267: if (file_printf(ms, "symbolic link to `%s'",
268: buf) == -1)
269: return -1;
1.1 deraadt 270: }
1.10 tedu 271: return 1;
1.1 deraadt 272: #endif
273: #ifdef S_IFSOCK
274: #ifndef __COHERENT__
275: case S_IFSOCK:
1.10 tedu 276: if (file_printf(ms, "socket") == -1)
277: return -1;
1.1 deraadt 278: return 1;
279: #endif
280: #endif
281: case S_IFREG:
282: break;
283: default:
1.10 tedu 284: file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
285: return -1;
1.1 deraadt 286: /*NOTREACHED*/
287: }
288:
289: /*
290: * regular file, check next possibility
1.10 tedu 291: *
292: * If stat() tells us the file has zero length, report here that
293: * the file is empty, so we can skip all the work of opening and
294: * reading the file.
295: * But if the -s option has been given, we skip this optimization,
296: * since on some systems, stat() reports zero size for raw disk
297: * partitions. (If the block special device really has zero length,
298: * the fact that it is empty will be detected and reported correctly
299: * when we read the file.)
1.1 deraadt 300: */
1.10 tedu 301: if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
1.13 chl 302: if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
303: file_printf(ms, mime ? "application/x-empty" :
304: "empty") == -1)
1.10 tedu 305: return -1;
1.1 deraadt 306: return 1;
307: }
308: return 0;
309: }
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