fstab.c revision 237061 
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 237061 2012-06-14 12:28:43Z kib $");
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 "un-namespace.h"
50
51static FILE *_fs_fp;
52static struct fstab _fs_fstab;
53static int LineNo = 0;
54static char *path_fstab;
55static char fstab_path[PATH_MAX];
56static int fsp_set = 0;
57
58static void error(int);
59static void fixfsfile(void);
60static int fstabscan(void);
61
62void
63setfstab(const char *file)
64{
65
66	if (file == NULL) {
67		path_fstab = _PATH_FSTAB;
68	} else {
69		strncpy(fstab_path, file, PATH_MAX);
70		fstab_path[PATH_MAX - 1] = '\0';
71		path_fstab = fstab_path;
72	}
73	fsp_set = 1;
74
75	return;
76}
77
78const char *
79getfstab (void)
80{
81
82	if (fsp_set)
83		return (path_fstab);
84	else
85		return (_PATH_FSTAB);
86}
87
88static void
89fixfsfile()
90{
91	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
92	struct stat sb;
93	struct statfs sf;
94
95	if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
96		return;
97	if (statfs("/", &sf) != 0)
98		return;
99	if (sf.f_mntfromname[0] == '/')
100		buf[0] = '\0';
101	else
102		strcpy(buf, _PATH_DEV);
103	strcat(buf, sf.f_mntfromname);
104	if (stat(buf, &sb) != 0 ||
105	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
106		return;
107	_fs_fstab.fs_spec = buf;
108}
109
110static int
111fstabscan()
112{
113	char *cp, *p;
114#define	MAXLINELENGTH	1024
115	static char line[MAXLINELENGTH];
116	char subline[MAXLINELENGTH];
117	int typexx;
118
119	for (;;) {
120
121		if (!(p = fgets(line, sizeof(line), _fs_fp)))
122			return(0);
123/* OLD_STYLE_FSTAB */
124		++LineNo;
125		if (*line == '#' || *line == '\n')
126			continue;
127		if (!strpbrk(p, " \t")) {
128			_fs_fstab.fs_spec = strsep(&p, ":\n");
129			_fs_fstab.fs_file = strsep(&p, ":\n");
130			fixfsfile();
131			_fs_fstab.fs_type = strsep(&p, ":\n");
132			if (_fs_fstab.fs_type) {
133				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
134					continue;
135				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
136				_fs_fstab.fs_vfstype =
137				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
138				    "ufs" : "swap";
139				if ((cp = strsep(&p, ":\n")) != NULL) {
140					_fs_fstab.fs_freq = atoi(cp);
141					if ((cp = strsep(&p, ":\n")) != NULL) {
142						_fs_fstab.fs_passno = atoi(cp);
143						return(1);
144					}
145				}
146			}
147			goto bad;
148		}
149/* OLD_STYLE_FSTAB */
150		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
151			;
152		_fs_fstab.fs_spec = cp;
153		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
154			continue;
155		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
156			;
157		_fs_fstab.fs_file = cp;
158		fixfsfile();
159		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
160			;
161		_fs_fstab.fs_vfstype = cp;
162		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
163			;
164		_fs_fstab.fs_mntops = cp;
165		if (_fs_fstab.fs_mntops == NULL)
166			goto bad;
167		_fs_fstab.fs_freq = 0;
168		_fs_fstab.fs_passno = 0;
169		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
170			;
171		if (cp != NULL) {
172			_fs_fstab.fs_freq = atoi(cp);
173			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
174				;
175			if (cp != NULL)
176				_fs_fstab.fs_passno = atoi(cp);
177		}
178		strcpy(subline, _fs_fstab.fs_mntops);
179		p = subline;
180		for (typexx = 0, cp = strsep(&p, ","); cp;
181		     cp = strsep(&p, ",")) {
182			if (strlen(cp) != 2)
183				continue;
184			if (!strcmp(cp, FSTAB_RW)) {
185				_fs_fstab.fs_type = FSTAB_RW;
186				break;
187			}
188			if (!strcmp(cp, FSTAB_RQ)) {
189				_fs_fstab.fs_type = FSTAB_RQ;
190				break;
191			}
192			if (!strcmp(cp, FSTAB_RO)) {
193				_fs_fstab.fs_type = FSTAB_RO;
194				break;
195			}
196			if (!strcmp(cp, FSTAB_SW)) {
197				_fs_fstab.fs_type = FSTAB_SW;
198				break;
199			}
200			if (!strcmp(cp, FSTAB_XX)) {
201				_fs_fstab.fs_type = FSTAB_XX;
202				typexx++;
203				break;
204			}
205		}
206		if (typexx)
207			continue;
208		if (cp != NULL)
209			return(1);
210
211bad:		/* no way to distinguish between EOF and syntax error */
212		error(EFTYPE);
213	}
214	/* NOTREACHED */
215}
216
217struct fstab *
218getfsent()
219{
220	if ((!_fs_fp && !setfsent()) || !fstabscan())
221		return((struct fstab *)NULL);
222	return(&_fs_fstab);
223}
224
225struct fstab *
226getfsspec(name)
227	const char *name;
228{
229	if (setfsent())
230		while (fstabscan())
231			if (!strcmp(_fs_fstab.fs_spec, name))
232				return(&_fs_fstab);
233	return((struct fstab *)NULL);
234}
235
236struct fstab *
237getfsfile(name)
238	const char *name;
239{
240	if (setfsent())
241		while (fstabscan())
242			if (!strcmp(_fs_fstab.fs_file, name))
243				return(&_fs_fstab);
244	return((struct fstab *)NULL);
245}
246
247int
248setfsent()
249{
250	int fd;
251
252	if (_fs_fp) {
253		rewind(_fs_fp);
254		LineNo = 0;
255		return(1);
256	}
257	if (fsp_set == 0) {
258		if (issetugid())
259			setfstab(NULL);
260		else
261			setfstab(getenv("PATH_FSTAB"));
262	}
263	fd = _open(path_fstab, O_RDONLY | O_CLOEXEC);
264	if (fd == -1) {
265		error(errno);
266		return (0);
267	}
268	_fs_fp = fdopen(fd, "r");
269	if (_fs_fp  != NULL) {
270		LineNo = 0;
271		return(1);
272	}
273	error(errno);
274	_close(fd);
275	return(0);
276}
277
278void
279endfsent()
280{
281	if (_fs_fp) {
282		(void)fclose(_fs_fp);
283		_fs_fp = NULL;
284	}
285
286	fsp_set = 0;
287}
288
289static void
290error(err)
291	int err;
292{
293	char *p;
294	char num[30];
295
296	(void)_write(STDERR_FILENO, "fstab: ", 7);
297	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
298	(void)_write(STDERR_FILENO, ":", 1);
299	sprintf(num, "%d: ", LineNo);
300	(void)_write(STDERR_FILENO, num, strlen(num));
301	p = strerror(err);
302	(void)_write(STDERR_FILENO, p, strlen(p));
303	(void)_write(STDERR_FILENO, "\n", 1);
304}
305