xref: /netbsd-src/lib/libc/gen/fstab.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: fstab.c,v 1.28 2006/08/12 23:49:54 christos Exp $	*/
2 
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 <sys/cdefs.h>
33 #if defined(LIBC_SCCS) && !defined(lint)
34 #if 0
35 static char sccsid[] = "@(#)fstab.c	8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: fstab.c,v 1.28 2006/08/12 23:49:54 christos Exp $");
38 #endif
39 #endif /* LIBC_SCCS and not lint */
40 
41 #include "namespace.h"
42 #include <sys/types.h>
43 
44 #include <assert.h>
45 #include <err.h>
46 #include <errno.h>
47 #include <fstab.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #ifdef __weak_alias
54 __weak_alias(endfsent,_endfsent)
55 __weak_alias(getfsent,_getfsent)
56 __weak_alias(getfsfile,_getfsfile)
57 __weak_alias(getfsspec,_getfsspec)
58 __weak_alias(setfsent,_setfsent)
59 #endif
60 
61 static FILE *_fs_fp;
62 static size_t _fs_lineno = 0;
63 static const char *_fs_file = _PATH_FSTAB;
64 static struct fstab _fs_fstab;
65 
66 static int fstabscan __P((void));
67 
68 static char *nextfld(char **, const char *);
69 static int fstabscan(void);
70 
71 
72 static char *
73 nextfld(char **str, const char *sep)
74 {
75 	char *ret;
76 
77 	_DIAGASSERT(str != NULL);
78 	_DIAGASSERT(sep != NULL);
79 
80 	while ((ret = stresep(str, sep, '\\')) != NULL && *ret == '\0')
81 		continue;
82 	return ret;
83 }
84 
85 
86 static int
87 fstabscan(void)
88 {
89 	char *cp, *lp, *sp;
90 #define	MAXLINELENGTH	1024
91 	static char line[MAXLINELENGTH];
92 	char subline[MAXLINELENGTH];
93 	static const char sep[] = ":\n";
94 	static const char ws[] = " \t\n";
95 	static const char *fstab_type[] = {
96 	    FSTAB_RW, FSTAB_RQ, FSTAB_RO, FSTAB_SW, FSTAB_DP, FSTAB_XX, NULL
97 	};
98 
99 	(void)memset(&_fs_fstab, 0, sizeof(_fs_fstab));
100 	for (;;) {
101 		if (!(lp = fgets(line, sizeof(line), _fs_fp)))
102 			return 0;
103 		_fs_lineno++;
104 /* OLD_STYLE_FSTAB */
105 		if (!strpbrk(lp, " \t")) {
106 			_fs_fstab.fs_spec = nextfld(&lp, sep);
107 			if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
108 				continue;
109 			_fs_fstab.fs_file = nextfld(&lp, sep);
110 			_fs_fstab.fs_type = nextfld(&lp, sep);
111 			if (_fs_fstab.fs_type) {
112 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
113 					continue;
114 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
115 				_fs_fstab.fs_vfstype =
116 				    __UNCONST(
117 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
118 				    "ufs" : "swap");
119 				if ((cp = nextfld(&lp, sep)) != NULL) {
120 					_fs_fstab.fs_freq = atoi(cp);
121 					if ((cp = nextfld(&lp, sep)) != NULL) {
122 						_fs_fstab.fs_passno = atoi(cp);
123 						return 1;
124 					}
125 				}
126 			}
127 			goto bad;
128 		}
129 /* OLD_STYLE_FSTAB */
130 		_fs_fstab.fs_spec = nextfld(&lp, ws);
131 		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
132 			continue;
133 		_fs_fstab.fs_file = nextfld(&lp, ws);
134 		_fs_fstab.fs_vfstype = nextfld(&lp, ws);
135 		_fs_fstab.fs_mntops = nextfld(&lp, ws);
136 		if (_fs_fstab.fs_mntops == NULL)
137 			goto bad;
138 		_fs_fstab.fs_freq = 0;
139 		_fs_fstab.fs_passno = 0;
140 		if ((cp = nextfld(&lp, ws)) != NULL) {
141 			_fs_fstab.fs_freq = atoi(cp);
142 			if ((cp = nextfld(&lp, ws)) != NULL)
143 				_fs_fstab.fs_passno = atoi(cp);
144 		}
145 
146 		/* subline truncated iff line truncated */
147 		(void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
148 		sp = subline;
149 
150 		while ((cp = nextfld(&sp, ",")) != NULL) {
151 			const char **tp;
152 
153 			if (strlen(cp) != 2)
154 				continue;
155 
156 			for (tp = fstab_type; *tp; tp++)
157 				if (strcmp(cp, *tp) == 0) {
158 					_fs_fstab.fs_type = __UNCONST(*tp);
159 					break;
160 				}
161 			if (*tp)
162 				break;
163 		}
164 		if (_fs_fstab.fs_type == NULL)
165 			goto bad;
166 		if (strcmp(_fs_fstab.fs_type, FSTAB_XX) == 0)
167 			continue;
168 		if (cp != NULL)
169 			return 1;
170 
171 bad:
172 		warnx("%s, %lu: Missing fields", _fs_file, (u_long)_fs_lineno);
173 	}
174 	/* NOTREACHED */
175 }
176 
177 struct fstab *
178 getfsent(void)
179 {
180 	if ((!_fs_fp && !setfsent()) || !fstabscan())
181 		return NULL;
182 	return &_fs_fstab;
183 }
184 
185 struct fstab *
186 getfsspec(const char *name)
187 {
188 
189 	_DIAGASSERT(name != NULL);
190 
191 	if (setfsent())
192 		while (fstabscan())
193 			if (!strcmp(_fs_fstab.fs_spec, name))
194 				return &_fs_fstab;
195 	return NULL;
196 }
197 
198 struct fstab *
199 getfsfile(const char *name)
200 {
201 
202 	_DIAGASSERT(name != NULL);
203 
204 	if (setfsent())
205 		while (fstabscan())
206 			if (!strcmp(_fs_fstab.fs_file, name))
207 				return &_fs_fstab;
208 	return NULL;
209 }
210 
211 int
212 setfsent(void)
213 {
214 	_fs_lineno = 0;
215 	if (_fs_fp) {
216 		rewind(_fs_fp);
217 		return 1;
218 	}
219 	if ((_fs_fp = fopen(_PATH_FSTAB, "r")) == NULL) {
220 		warn("Cannot open `%s'", _PATH_FSTAB);
221 		return 0;
222 	}
223 	return 1;
224 }
225 
226 void
227 endfsent(void)
228 {
229 	if (_fs_fp) {
230 		(void)fclose(_fs_fp);
231 		_fs_fp = NULL;
232 	}
233 }
234