1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include "namespace.h"
33#include <sys/param.h>
34#include <sys/mount.h>
35#include <sys/stat.h>
36
37#include <errno.h>
38#include <fstab.h>
39#include <paths.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44#include <vis.h>
45#include "un-namespace.h"
46
47static FILE *_fs_fp;
48static struct fstab _fs_fstab;
49static int LineNo = 0;
50static char *path_fstab;
51static char fstab_path[PATH_MAX];
52static int fsp_set = 0;
53
54static void error(int);
55static void fixfsfile(void);
56static int fstabscan(void);
57
58void
59setfstab(const char *file)
60{
61
62	if (file == NULL) {
63		path_fstab = _PATH_FSTAB;
64	} else {
65		strncpy(fstab_path, file, PATH_MAX);
66		fstab_path[PATH_MAX - 1] = '\0';
67		path_fstab = fstab_path;
68	}
69	fsp_set = 1;
70
71	return;
72}
73
74const char *
75getfstab(void)
76{
77
78	if (fsp_set)
79		return (path_fstab);
80	else
81		return (_PATH_FSTAB);
82}
83
84static void
85fixfsfile(void)
86{
87	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
88	struct stat sb;
89	struct statfs sf;
90
91	if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
92		return;
93	if (statfs("/", &sf) != 0)
94		return;
95	if (sf.f_mntfromname[0] == '/')
96		buf[0] = '\0';
97	else
98		strcpy(buf, _PATH_DEV);
99	strcat(buf, sf.f_mntfromname);
100	if (stat(buf, &sb) != 0 ||
101	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
102		return;
103	_fs_fstab.fs_spec = buf;
104}
105
106static int
107fstabscan(void)
108{
109	char *cp, *p;
110#define	MAXLINELENGTH	1024
111	static char line[MAXLINELENGTH];
112	char subline[MAXLINELENGTH];
113	int typexx;
114
115	for (;;) {
116
117		if (!(p = fgets(line, sizeof(line), _fs_fp)))
118			return (0);
119/* OLD_STYLE_FSTAB */
120		++LineNo;
121		if (*line == '#' || *line == '\n')
122			continue;
123		if (!strpbrk(p, " \t")) {
124			_fs_fstab.fs_spec = strsep(&p, ":\n");
125			_fs_fstab.fs_file = strsep(&p, ":\n");
126			fixfsfile();
127			_fs_fstab.fs_type = strsep(&p, ":\n");
128			if (_fs_fstab.fs_type) {
129				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
130					continue;
131				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
132				_fs_fstab.fs_vfstype =
133				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
134				    "ufs" : "swap";
135				if ((cp = strsep(&p, ":\n")) != NULL) {
136					_fs_fstab.fs_freq = atoi(cp);
137					if ((cp = strsep(&p, ":\n")) != NULL) {
138						_fs_fstab.fs_passno = atoi(cp);
139						return (1);
140					}
141				}
142			}
143			goto bad;
144		}
145/* OLD_STYLE_FSTAB */
146		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
147			;
148		_fs_fstab.fs_spec = cp;
149		if (_fs_fstab.fs_spec == NULL || *_fs_fstab.fs_spec == '#')
150			continue;
151		if (strunvis(_fs_fstab.fs_spec, _fs_fstab.fs_spec) < 0)
152			goto bad;
153		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
154			;
155		_fs_fstab.fs_file = cp;
156		if (_fs_fstab.fs_file == NULL)
157			goto bad;
158		if (strunvis(_fs_fstab.fs_file, _fs_fstab.fs_file) < 0)
159			goto bad;
160		fixfsfile();
161		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
162			;
163		_fs_fstab.fs_vfstype = cp;
164		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
165			;
166		_fs_fstab.fs_mntops = cp;
167		if (_fs_fstab.fs_mntops == NULL)
168			goto bad;
169		_fs_fstab.fs_freq = 0;
170		_fs_fstab.fs_passno = 0;
171		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
172			;
173		if (cp != NULL) {
174			_fs_fstab.fs_freq = atoi(cp);
175			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
176				;
177			if (cp != NULL)
178				_fs_fstab.fs_passno = atoi(cp);
179		}
180		(void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
181		p = subline;
182		for (typexx = 0, cp = strsep(&p, ","); cp;
183		     cp = strsep(&p, ",")) {
184			if (strlen(cp) != 2)
185				continue;
186			if (!strcmp(cp, FSTAB_RW)) {
187				_fs_fstab.fs_type = FSTAB_RW;
188				break;
189			}
190			if (!strcmp(cp, FSTAB_RQ)) {
191				_fs_fstab.fs_type = FSTAB_RQ;
192				break;
193			}
194			if (!strcmp(cp, FSTAB_RO)) {
195				_fs_fstab.fs_type = FSTAB_RO;
196				break;
197			}
198			if (!strcmp(cp, FSTAB_SW)) {
199				_fs_fstab.fs_type = FSTAB_SW;
200				break;
201			}
202			if (!strcmp(cp, FSTAB_XX)) {
203				_fs_fstab.fs_type = FSTAB_XX;
204				typexx++;
205				break;
206			}
207		}
208		if (typexx)
209			continue;
210		if (cp != NULL)
211			return (1);
212
213bad:		/* no way to distinguish between EOF and syntax error */
214		error(EFTYPE);
215	}
216	/* NOTREACHED */
217}
218
219struct fstab *
220getfsent(void)
221{
222
223	if ((!_fs_fp && !setfsent()) || !fstabscan())
224		return (NULL);
225	return (&_fs_fstab);
226}
227
228struct fstab *
229getfsspec(const char *name)
230{
231
232	if (setfsent())
233		while (fstabscan())
234			if (!strcmp(_fs_fstab.fs_spec, name))
235				return (&_fs_fstab);
236	return (NULL);
237}
238
239struct fstab *
240getfsfile(const char *name)
241{
242
243	if (setfsent())
244		while (fstabscan())
245			if (!strcmp(_fs_fstab.fs_file, name))
246				return (&_fs_fstab);
247	return (NULL);
248}
249
250int
251setfsent(void)
252{
253	if (_fs_fp) {
254		rewind(_fs_fp);
255		LineNo = 0;
256		return (1);
257	}
258	if (fsp_set == 0)
259		setfstab(secure_getenv("PATH_FSTAB"));
260	if ((_fs_fp = fopen(path_fstab, "re")) != NULL) {
261		LineNo = 0;
262		return (1);
263	}
264	error(errno);
265	return (0);
266}
267
268void
269endfsent(void)
270{
271
272	if (_fs_fp) {
273		(void)fclose(_fs_fp);
274		_fs_fp = NULL;
275	}
276
277	fsp_set = 0;
278}
279
280static void
281error(int err)
282{
283	char *p;
284	char num[30];
285
286	(void)_write(STDERR_FILENO, "fstab: ", 7);
287	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
288	(void)_write(STDERR_FILENO, ":", 1);
289	sprintf(num, "%d: ", LineNo);
290	(void)_write(STDERR_FILENO, num, strlen(num));
291	p = strerror(err);
292	(void)_write(STDERR_FILENO, p, strlen(p));
293	(void)_write(STDERR_FILENO, "\n", 1);
294}
295