xref: /freebsd/lib/libc/gen/fstab.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675)
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 
38 #include <sys/param.h>
39 #include <sys/mount.h>
40 #include <sys/stat.h>
41 
42 #include <errno.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 
50 static FILE *_fs_fp;
51 static struct fstab _fs_fstab;
52 static int LineNo = 0;
53 
54 static void error __P((int));
55 static void fixfsfile __P((void));
56 static int fstabscan __P((void));
57 
58 static void
59 fixfsfile()
60 {
61 	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
62 	struct stat sb;
63 	struct statfs sf;
64 
65 	if (strcmp(_fs_fstab.fs_file, "/") != 0)
66 		return;
67 	if (statfs("/", &sf) != 0)
68 		return;
69 	if (sf.f_mntfromname[0] == '/')
70 		buf[0] = '\0';
71 	else
72 		strcpy(buf, _PATH_DEV);
73 	strcat(buf, sf.f_mntfromname);
74 	if (stat(buf, &sb) != 0 || !S_ISBLK(sb.st_mode))
75 		return;
76 	_fs_fstab.fs_spec = buf;
77 }
78 
79 static int
80 fstabscan()
81 {
82 	char *cp, *p;
83 #define	MAXLINELENGTH	1024
84 	static char line[MAXLINELENGTH];
85 	char subline[MAXLINELENGTH];
86 	int typexx;
87 
88 	for (;;) {
89 
90 		if (!(p = fgets(line, sizeof(line), _fs_fp)))
91 			return(0);
92 /* OLD_STYLE_FSTAB */
93 		++LineNo;
94 		if (*line == '#' || *line == '\n')
95 			continue;
96 		if (!strpbrk(p, " \t")) {
97 			_fs_fstab.fs_spec = strsep(&p, ":\n");
98 			_fs_fstab.fs_file = strsep(&p, ":\n");
99 			fixfsfile();
100 			_fs_fstab.fs_type = strsep(&p, ":\n");
101 			if (_fs_fstab.fs_type) {
102 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
103 					continue;
104 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
105 				_fs_fstab.fs_vfstype =
106 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
107 				    "ufs" : "swap";
108 				if ((cp = strsep(&p, ":\n")) != NULL) {
109 					_fs_fstab.fs_freq = atoi(cp);
110 					if ((cp = strsep(&p, ":\n")) != NULL) {
111 						_fs_fstab.fs_passno = atoi(cp);
112 						return(1);
113 					}
114 				}
115 			}
116 			goto bad;
117 		}
118 /* OLD_STYLE_FSTAB */
119 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
120 			;
121 		_fs_fstab.fs_spec = cp;
122 		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
123 			continue;
124 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
125 			;
126 		_fs_fstab.fs_file = cp;
127 		fixfsfile();
128 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
129 			;
130 		_fs_fstab.fs_vfstype = cp;
131 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
132 			;
133 		_fs_fstab.fs_mntops = cp;
134 		if (_fs_fstab.fs_mntops == NULL)
135 			goto bad;
136 		_fs_fstab.fs_freq = 0;
137 		_fs_fstab.fs_passno = 0;
138 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
139 			;
140 		if (cp != NULL) {
141 			_fs_fstab.fs_freq = atoi(cp);
142 			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
143 				;
144 			if (cp != NULL)
145 				_fs_fstab.fs_passno = atoi(cp);
146 		}
147 		strcpy(subline, _fs_fstab.fs_mntops);
148 		p = subline;
149 		for (typexx = 0, cp = strsep(&p, ","); cp;
150 		     cp = strsep(&p, ",")) {
151 			if (strlen(cp) != 2)
152 				continue;
153 			if (!strcmp(cp, FSTAB_RW)) {
154 				_fs_fstab.fs_type = FSTAB_RW;
155 				break;
156 			}
157 			if (!strcmp(cp, FSTAB_RQ)) {
158 				_fs_fstab.fs_type = FSTAB_RQ;
159 				break;
160 			}
161 			if (!strcmp(cp, FSTAB_RO)) {
162 				_fs_fstab.fs_type = FSTAB_RO;
163 				break;
164 			}
165 			if (!strcmp(cp, FSTAB_SW)) {
166 				_fs_fstab.fs_type = FSTAB_SW;
167 				break;
168 			}
169 			if (!strcmp(cp, FSTAB_XX)) {
170 				_fs_fstab.fs_type = FSTAB_XX;
171 				typexx++;
172 				break;
173 			}
174 		}
175 		if (typexx)
176 			continue;
177 		if (cp != NULL)
178 			return(1);
179 
180 bad:		/* no way to distinguish between EOF and syntax error */
181 		error(EFTYPE);
182 	}
183 	/* NOTREACHED */
184 }
185 
186 struct fstab *
187 getfsent()
188 {
189 	if ((!_fs_fp && !setfsent()) || !fstabscan())
190 		return((struct fstab *)NULL);
191 	return(&_fs_fstab);
192 }
193 
194 struct fstab *
195 getfsspec(name)
196 	register const char *name;
197 {
198 	if (setfsent())
199 		while (fstabscan())
200 			if (!strcmp(_fs_fstab.fs_spec, name))
201 				return(&_fs_fstab);
202 	return((struct fstab *)NULL);
203 }
204 
205 struct fstab *
206 getfsfile(name)
207 	register const char *name;
208 {
209 	if (setfsent())
210 		while (fstabscan())
211 			if (!strcmp(_fs_fstab.fs_file, name))
212 				return(&_fs_fstab);
213 	return((struct fstab *)NULL);
214 }
215 
216 int
217 setfsent()
218 {
219 	if (_fs_fp) {
220 		rewind(_fs_fp);
221 		LineNo = 0;
222 		return(1);
223 	}
224 	if ((_fs_fp = fopen(_PATH_FSTAB, "r")) != NULL) {
225 		LineNo = 0;
226 		return(1);
227 	}
228 	error(errno);
229 	return(0);
230 }
231 
232 void
233 endfsent()
234 {
235 	if (_fs_fp) {
236 		(void)fclose(_fs_fp);
237 		_fs_fp = NULL;
238 	}
239 }
240 
241 static void
242 error(err)
243 	int err;
244 {
245 	char *p;
246 	char num[30];
247 
248 	(void)write(STDERR_FILENO, "fstab: ", 7);
249 	(void)write(STDERR_FILENO, _PATH_FSTAB, sizeof(_PATH_FSTAB) - 1);
250 	(void)write(STDERR_FILENO, ":", 1);
251 	sprintf(num, "%d: ", LineNo);
252 	(void)write(STDERR_FILENO, num, strlen(num));
253 	p = strerror(err);
254 	(void)write(STDERR_FILENO, p, strlen(p));
255 	(void)write(STDERR_FILENO, "\n", 1);
256 }
257