fstab.c revision 241440 
1/*
2 * Copyright (c) 1980, 1988, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR 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.
28 */
29
30#if defined(LIBC_SCCS) && !defined(lint)
31static char sccsid[] = "@(#)fstab.c	8.1 (Berkeley) 6/4/93";
32#endif /* LIBC_SCCS and not lint */
33#include <sys/cdefs.h>
34__FBSDID("$FreeBSD: head/lib/libc/gen/fstab.c 241440 2012-10-11 07:54:29Z stefanf $");
35
36#include "namespace.h"
37#include <sys/param.h>
38#include <sys/mount.h>
39#include <sys/stat.h>
40
41#include <errno.h>
42#include <fcntl.h>
43#include <fstab.h>
44#include <paths.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48#include <unistd.h>
49#include <vis.h>
50#include "un-namespace.h"
51
52static FILE *_fs_fp;
53static struct fstab _fs_fstab;
54static int LineNo = 0;
55static char *path_fstab;
56static char fstab_path[PATH_MAX];
57static int fsp_set = 0;
58
59static void error(int);
60static void fixfsfile(void);
61static int fstabscan(void);
62
63void
64setfstab(const char *file)
65{
66
67	if (file == NULL) {
68		path_fstab = _PATH_FSTAB;
69	} else {
70		strncpy(fstab_path, file, PATH_MAX);
71		fstab_path[PATH_MAX - 1] = '\0';
72		path_fstab = fstab_path;
73	}
74	fsp_set = 1;
75
76	return;
77}
78
79const char *
80getfstab(void)
81{
82
83	if (fsp_set)
84		return (path_fstab);
85	else
86		return (_PATH_FSTAB);
87}
88
89static void
90fixfsfile(void)
91{
92	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
93	struct stat sb;
94	struct statfs sf;
95
96	if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
97		return;
98	if (statfs("/", &sf) != 0)
99		return;
100	if (sf.f_mntfromname[0] == '/')
101		buf[0] = '\0';
102	else
103		strcpy(buf, _PATH_DEV);
104	strcat(buf, sf.f_mntfromname);
105	if (stat(buf, &sb) != 0 ||
106	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
107		return;
108	_fs_fstab.fs_spec = buf;
109}
110
111static int
112fstabscan(void)
113{
114	char *cp, *p;
115#define	MAXLINELENGTH	1024
116	static char line[MAXLINELENGTH];
117	char subline[MAXLINELENGTH];
118	int typexx;
119
120	for (;;) {
121
122		if (!(p = fgets(line, sizeof(line), _fs_fp)))
123			return (0);
124/* OLD_STYLE_FSTAB */
125		++LineNo;
126		if (*line == '#' || *line == '\n')
127			continue;
128		if (!strpbrk(p, " \t")) {
129			_fs_fstab.fs_spec = strsep(&p, ":\n");
130			_fs_fstab.fs_file = strsep(&p, ":\n");
131			fixfsfile();
132			_fs_fstab.fs_type = strsep(&p, ":\n");
133			if (_fs_fstab.fs_type) {
134				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
135					continue;
136				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
137				_fs_fstab.fs_vfstype =
138				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
139				    "ufs" : "swap";
140				if ((cp = strsep(&p, ":\n")) != NULL) {
141					_fs_fstab.fs_freq = atoi(cp);
142					if ((cp = strsep(&p, ":\n")) != NULL) {
143						_fs_fstab.fs_passno = atoi(cp);
144						return (1);
145					}
146				}
147			}
148			goto bad;
149		}
150/* OLD_STYLE_FSTAB */
151		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
152			;
153		if (strunvis(cp, cp) < 0)
154			goto bad;
155		_fs_fstab.fs_spec = cp;
156		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
157			continue;
158		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
159			;
160		if (strunvis(cp, cp) < 0)
161			goto bad;
162		_fs_fstab.fs_file = cp;
163		fixfsfile();
164		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
165			;
166		_fs_fstab.fs_vfstype = cp;
167		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
168			;
169		_fs_fstab.fs_mntops = cp;
170		if (_fs_fstab.fs_mntops == NULL)
171			goto bad;
172		_fs_fstab.fs_freq = 0;
173		_fs_fstab.fs_passno = 0;
174		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
175			;
176		if (cp != NULL) {
177			_fs_fstab.fs_freq = atoi(cp);
178			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
179				;
180			if (cp != NULL)
181				_fs_fstab.fs_passno = atoi(cp);
182		}
183		strcpy(subline, _fs_fstab.fs_mntops);
184		p = subline;
185		for (typexx = 0, cp = strsep(&p, ","); cp;
186		     cp = strsep(&p, ",")) {
187			if (strlen(cp) != 2)
188				continue;
189			if (!strcmp(cp, FSTAB_RW)) {
190				_fs_fstab.fs_type = FSTAB_RW;
191				break;
192			}
193			if (!strcmp(cp, FSTAB_RQ)) {
194				_fs_fstab.fs_type = FSTAB_RQ;
195				break;
196			}
197			if (!strcmp(cp, FSTAB_RO)) {
198				_fs_fstab.fs_type = FSTAB_RO;
199				break;
200			}
201			if (!strcmp(cp, FSTAB_SW)) {
202				_fs_fstab.fs_type = FSTAB_SW;
203				break;
204			}
205			if (!strcmp(cp, FSTAB_XX)) {
206				_fs_fstab.fs_type = FSTAB_XX;
207				typexx++;
208				break;
209			}
210		}
211		if (typexx)
212			continue;
213		if (cp != NULL)
214			return (1);
215
216bad:		/* no way to distinguish between EOF and syntax error */
217		error(EFTYPE);
218	}
219	/* NOTREACHED */
220}
221
222struct fstab *
223getfsent(void)
224{
225
226	if ((!_fs_fp && !setfsent()) || !fstabscan())
227		return (NULL);
228	return (&_fs_fstab);
229}
230
231struct fstab *
232getfsspec(const char *name)
233{
234
235	if (setfsent())
236		while (fstabscan())
237			if (!strcmp(_fs_fstab.fs_spec, name))
238				return (&_fs_fstab);
239	return (NULL);
240}
241
242struct fstab *
243getfsfile(const char *name)
244{
245
246	if (setfsent())
247		while (fstabscan())
248			if (!strcmp(_fs_fstab.fs_file, name))
249				return (&_fs_fstab);
250	return (NULL);
251}
252
253int
254setfsent(void)
255{
256	int fd;
257
258	if (_fs_fp) {
259		rewind(_fs_fp);
260		LineNo = 0;
261		return (1);
262	}
263	if (fsp_set == 0) {
264		if (issetugid())
265			setfstab(NULL);
266		else
267			setfstab(getenv("PATH_FSTAB"));
268	}
269	fd = _open(path_fstab, O_RDONLY | O_CLOEXEC);
270	if (fd == -1) {
271		error(errno);
272		return (0);
273	}
274	_fs_fp = fdopen(fd, "r");
275	if (_fs_fp  != NULL) {
276		LineNo = 0;
277		return (1);
278	}
279	error(errno);
280	_close(fd);
281	return (0);
282}
283
284void
285endfsent(void)
286{
287
288	if (_fs_fp) {
289		(void)fclose(_fs_fp);
290		_fs_fp = NULL;
291	}
292
293	fsp_set = 0;
294}
295
296static void
297error(int err)
298{
299	char *p;
300	char num[30];
301
302	(void)_write(STDERR_FILENO, "fstab: ", 7);
303	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
304	(void)_write(STDERR_FILENO, ":", 1);
305	sprintf(num, "%d: ", LineNo);
306	(void)_write(STDERR_FILENO, num, strlen(num));
307	p = strerror(err);
308	(void)_write(STDERR_FILENO, p, strlen(p));
309	(void)_write(STDERR_FILENO, "\n", 1);
310}
311