xref: /openbsd-src/lib/libc/gen/fstab.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: fstab.c,v 1.16 2007/09/27 14:07:23 blambert Exp $ */
2 /*
3  * Copyright (c) 1980, 1988, 1993
4  *	The Regents of the University of California.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the University nor the names of its contributors
15  *    may be used to endorse or promote products derived from this software
16  *    without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/types.h>
32 #include <sys/uio.h>
33 #include <sys/stat.h>
34 
35 #include <errno.h>
36 #include <limits.h>
37 #include <fstab.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <unistd.h>
42 
43 static FILE *_fs_fp;
44 static struct fstab _fs_fstab;
45 
46 static void error(int);
47 static int fstabscan(void);
48 
49 static int
50 fstabscan(void)
51 {
52 	char *cp;
53 #define	MAXLINELENGTH	1024
54 	static char line[MAXLINELENGTH];
55 	char subline[MAXLINELENGTH];
56 	const char *errstr;
57 	char *last;
58 	int typexx;
59 
60 	for (;;) {
61 		if (!(cp = fgets(line, sizeof(line), _fs_fp)))
62 			return(0);
63 /* OLD_STYLE_FSTAB */
64 		if (!strpbrk(cp, " \t")) {
65 			_fs_fstab.fs_spec = strtok_r(cp, ":\n", &last);
66 			if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
67 				continue;
68 			_fs_fstab.fs_file = strtok_r((char *)NULL, ":\n", &last);
69 			_fs_fstab.fs_type = strtok_r((char *)NULL, ":\n", &last);
70 			if (_fs_fstab.fs_type) {
71 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
72 					continue;
73 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
74 				_fs_fstab.fs_vfstype =
75 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
76 				    "ufs" : "swap";
77 				if ((cp = strtok_r((char *)NULL, ":\n", &last))) {
78 					_fs_fstab.fs_freq = strtonum(cp, 0,
79 					    INT_MAX, &errstr);
80 					if (errstr)
81 						goto bad;
82 					if ((cp = strtok_r((char *)NULL,
83 					    ":\n", &last))) {
84 						_fs_fstab.fs_passno =
85 						    strtonum(cp, 0, INT_MAX,
86 						    &errstr);
87 						if (errstr)
88 							goto bad;
89 						return(1);
90 					}
91 				}
92 			}
93 			goto bad;
94 		}
95 /* OLD_STYLE_FSTAB */
96 		_fs_fstab.fs_spec = strtok_r(cp, " \t\n", &last);
97 		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
98 			continue;
99 		_fs_fstab.fs_file = strtok_r((char *)NULL, " \t\n", &last);
100 		_fs_fstab.fs_vfstype = strtok_r((char *)NULL, " \t\n", &last);
101 		_fs_fstab.fs_mntops = strtok_r((char *)NULL, " \t\n", &last);
102 		if (_fs_fstab.fs_mntops == NULL)
103 			goto bad;
104 		_fs_fstab.fs_freq = 0;
105 		_fs_fstab.fs_passno = 0;
106 		if ((cp = strtok_r((char *)NULL, " \t\n", &last)) != NULL) {
107 			_fs_fstab.fs_freq = strtonum(cp, 0, INT_MAX, &errstr);
108 			if (errstr)
109 				goto bad;
110 			if ((cp = strtok_r((char *)NULL, " \t\n", &last)) != NULL) {
111 				_fs_fstab.fs_passno = strtonum(cp, 0, INT_MAX,
112 				    &errstr);
113 				if (errstr)
114 					goto bad;
115 			}
116 		}
117 		strlcpy(subline, _fs_fstab.fs_mntops, sizeof subline);
118 		for (typexx = 0, cp = strtok_r(subline, ",", &last); cp;
119 		     cp = strtok_r((char *)NULL, ",", &last)) {
120 			if (strlen(cp) != 2)
121 				continue;
122 			if (!strcmp(cp, FSTAB_RW)) {
123 				_fs_fstab.fs_type = FSTAB_RW;
124 				break;
125 			}
126 			if (!strcmp(cp, FSTAB_RQ)) {
127 				_fs_fstab.fs_type = FSTAB_RQ;
128 				break;
129 			}
130 			if (!strcmp(cp, FSTAB_RO)) {
131 				_fs_fstab.fs_type = FSTAB_RO;
132 				break;
133 			}
134 			if (!strcmp(cp, FSTAB_SW)) {
135 				_fs_fstab.fs_type = FSTAB_SW;
136 				break;
137 			}
138 			if (!strcmp(cp, FSTAB_XX)) {
139 				_fs_fstab.fs_type = FSTAB_XX;
140 				typexx++;
141 				break;
142 			}
143 		}
144 		if (typexx)
145 			continue;
146 		if (cp != NULL)
147 			return(1);
148 
149 bad:		/* no way to distinguish between EOF and syntax error */
150 		error(EFTYPE);
151 	}
152 	/* NOTREACHED */
153 }
154 
155 struct fstab *
156 getfsent(void)
157 {
158 	if ((!_fs_fp && !setfsent()) || !fstabscan())
159 		return(NULL);
160 	return(&_fs_fstab);
161 }
162 
163 struct fstab *
164 getfsspec(const char *name)
165 {
166 	if (setfsent())
167 		while (fstabscan())
168 			if (!strcmp(_fs_fstab.fs_spec, name))
169 				return(&_fs_fstab);
170 	return((struct fstab *)NULL);
171 }
172 
173 struct fstab *
174 getfsfile(const char *name)
175 {
176 	if (setfsent())
177 		while (fstabscan())
178 			if (!strcmp(_fs_fstab.fs_file, name))
179 				return(&_fs_fstab);
180 	return((struct fstab *)NULL);
181 }
182 
183 int
184 setfsent(void)
185 {
186 	struct stat sbuf;
187 
188 	if (_fs_fp) {
189 		rewind(_fs_fp);
190 		return(1);
191 	}
192 
193 	if (stat(_PATH_FSTAB, &sbuf) != 0)
194 		goto fail;
195 	if ((sbuf.st_size == 0) || ((sbuf.st_mode & S_IFMT) != S_IFREG)) {
196 		errno = EFTYPE;
197 		goto fail;
198 	}
199 
200 	if ((_fs_fp = fopen(_PATH_FSTAB, "r")))
201 		return(1);
202 
203 fail:
204 	error(errno);
205 	return(0);
206 }
207 
208 void
209 endfsent(void)
210 {
211 	if (_fs_fp) {
212 		(void)fclose(_fs_fp);
213 		_fs_fp = NULL;
214 	}
215 }
216 
217 static void
218 error(int err)
219 {
220 	struct iovec iov[5];
221 
222 	iov[0].iov_base = "fstab: ";
223 	iov[0].iov_len = 7;
224 	iov[1].iov_base = _PATH_FSTAB;
225 	iov[1].iov_len = sizeof(_PATH_FSTAB) - 1;
226 	iov[2].iov_base =  ": ";
227 	iov[2].iov_len = 2;
228 	iov[3].iov_base = strerror(err);
229 	iov[3].iov_len = strlen(iov[3].iov_base);
230 	iov[4].iov_base = "\n";
231 	iov[4].iov_len = 1;
232 	(void)writev(STDERR_FILENO, iov, 5);
233 }
234