xref: /freebsd/lib/libc/gen/fstab.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)fstab.c	8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "namespace.h"
41 #include <sys/param.h>
42 #include <sys/mount.h>
43 #include <sys/stat.h>
44 
45 #include <errno.h>
46 #include <fstab.h>
47 #include <paths.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include "un-namespace.h"
53 
54 static FILE *_fs_fp;
55 static struct fstab _fs_fstab;
56 static int LineNo = 0;
57 static char *path_fstab;
58 static char fstab_path[PATH_MAX];
59 static int fsp_set = 0;
60 
61 static void error(int);
62 static void fixfsfile(void);
63 static int fstabscan(void);
64 
65 void
66 setfstab(const char *file)
67 {
68 
69 	if (file == NULL) {
70 		path_fstab = _PATH_FSTAB;
71 	} else {
72 		strncpy(fstab_path, file, PATH_MAX);
73 		fstab_path[PATH_MAX - 1] = '\0';
74 		path_fstab = fstab_path;
75 	}
76 	fsp_set = 1;
77 
78 	return;
79 }
80 
81 const char *
82 getfstab (void)
83 {
84 
85 	if (fsp_set)
86 		return (path_fstab);
87 	else
88 		return (_PATH_FSTAB);
89 }
90 
91 static void
92 fixfsfile()
93 {
94 	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
95 	struct stat sb;
96 	struct statfs sf;
97 
98 	if (strcmp(_fs_fstab.fs_file, "/") != 0)
99 		return;
100 	if (statfs("/", &sf) != 0)
101 		return;
102 	if (sf.f_mntfromname[0] == '/')
103 		buf[0] = '\0';
104 	else
105 		strcpy(buf, _PATH_DEV);
106 	strcat(buf, sf.f_mntfromname);
107 	if (stat(buf, &sb) != 0 ||
108 	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
109 		return;
110 	_fs_fstab.fs_spec = buf;
111 }
112 
113 static int
114 fstabscan()
115 {
116 	char *cp, *p;
117 #define	MAXLINELENGTH	1024
118 	static char line[MAXLINELENGTH];
119 	char subline[MAXLINELENGTH];
120 	int typexx;
121 
122 	for (;;) {
123 
124 		if (!(p = fgets(line, sizeof(line), _fs_fp)))
125 			return(0);
126 /* OLD_STYLE_FSTAB */
127 		++LineNo;
128 		if (*line == '#' || *line == '\n')
129 			continue;
130 		if (!strpbrk(p, " \t")) {
131 			_fs_fstab.fs_spec = strsep(&p, ":\n");
132 			_fs_fstab.fs_file = strsep(&p, ":\n");
133 			fixfsfile();
134 			_fs_fstab.fs_type = strsep(&p, ":\n");
135 			if (_fs_fstab.fs_type) {
136 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
137 					continue;
138 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
139 				_fs_fstab.fs_vfstype =
140 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
141 				    "ufs" : "swap";
142 				if ((cp = strsep(&p, ":\n")) != NULL) {
143 					_fs_fstab.fs_freq = atoi(cp);
144 					if ((cp = strsep(&p, ":\n")) != NULL) {
145 						_fs_fstab.fs_passno = atoi(cp);
146 						return(1);
147 					}
148 				}
149 			}
150 			goto bad;
151 		}
152 /* OLD_STYLE_FSTAB */
153 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
154 			;
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 		_fs_fstab.fs_file = cp;
161 		fixfsfile();
162 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
163 			;
164 		_fs_fstab.fs_vfstype = cp;
165 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
166 			;
167 		_fs_fstab.fs_mntops = cp;
168 		if (_fs_fstab.fs_mntops == NULL)
169 			goto bad;
170 		_fs_fstab.fs_freq = 0;
171 		_fs_fstab.fs_passno = 0;
172 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
173 			;
174 		if (cp != NULL) {
175 			_fs_fstab.fs_freq = atoi(cp);
176 			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
177 				;
178 			if (cp != NULL)
179 				_fs_fstab.fs_passno = atoi(cp);
180 		}
181 		strcpy(subline, _fs_fstab.fs_mntops);
182 		p = subline;
183 		for (typexx = 0, cp = strsep(&p, ","); cp;
184 		     cp = strsep(&p, ",")) {
185 			if (strlen(cp) != 2)
186 				continue;
187 			if (!strcmp(cp, FSTAB_RW)) {
188 				_fs_fstab.fs_type = FSTAB_RW;
189 				break;
190 			}
191 			if (!strcmp(cp, FSTAB_RQ)) {
192 				_fs_fstab.fs_type = FSTAB_RQ;
193 				break;
194 			}
195 			if (!strcmp(cp, FSTAB_RO)) {
196 				_fs_fstab.fs_type = FSTAB_RO;
197 				break;
198 			}
199 			if (!strcmp(cp, FSTAB_SW)) {
200 				_fs_fstab.fs_type = FSTAB_SW;
201 				break;
202 			}
203 			if (!strcmp(cp, FSTAB_XX)) {
204 				_fs_fstab.fs_type = FSTAB_XX;
205 				typexx++;
206 				break;
207 			}
208 		}
209 		if (typexx)
210 			continue;
211 		if (cp != NULL)
212 			return(1);
213 
214 bad:		/* no way to distinguish between EOF and syntax error */
215 		error(EFTYPE);
216 	}
217 	/* NOTREACHED */
218 }
219 
220 struct fstab *
221 getfsent()
222 {
223 	if ((!_fs_fp && !setfsent()) || !fstabscan())
224 		return((struct fstab *)NULL);
225 	return(&_fs_fstab);
226 }
227 
228 struct fstab *
229 getfsspec(name)
230 	const char *name;
231 {
232 	if (setfsent())
233 		while (fstabscan())
234 			if (!strcmp(_fs_fstab.fs_spec, name))
235 				return(&_fs_fstab);
236 	return((struct fstab *)NULL);
237 }
238 
239 struct fstab *
240 getfsfile(name)
241 	const char *name;
242 {
243 	if (setfsent())
244 		while (fstabscan())
245 			if (!strcmp(_fs_fstab.fs_file, name))
246 				return(&_fs_fstab);
247 	return((struct fstab *)NULL);
248 }
249 
250 int
251 setfsent()
252 {
253 	if (_fs_fp) {
254 		rewind(_fs_fp);
255 		LineNo = 0;
256 		return(1);
257 	}
258 	if (fsp_set == 0) {
259 		if (issetugid())
260 			setfstab(NULL);
261 		else
262 			setfstab(getenv("PATH_FSTAB"));
263 	}
264 	if ((_fs_fp = fopen(path_fstab, "r")) != NULL) {
265 		LineNo = 0;
266 		return(1);
267 	}
268 	error(errno);
269 	return(0);
270 }
271 
272 void
273 endfsent()
274 {
275 	if (_fs_fp) {
276 		(void)fclose(_fs_fp);
277 		_fs_fp = NULL;
278 	}
279 
280 	fsp_set = 0;
281 }
282 
283 static void
284 error(err)
285 	int err;
286 {
287 	char *p;
288 	char num[30];
289 
290 	(void)_write(STDERR_FILENO, "fstab: ", 7);
291 	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
292 	(void)_write(STDERR_FILENO, ":", 1);
293 	sprintf(num, "%d: ", LineNo);
294 	(void)_write(STDERR_FILENO, num, strlen(num));
295 	p = strerror(err);
296 	(void)_write(STDERR_FILENO, p, strlen(p));
297 	(void)_write(STDERR_FILENO, "\n", 1);
298 }
299