1 /*	$OpenBSD: fstab.c,v 1.15 2005/08/08 08:05:34 espie 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
fstabscan(void)50 fstabscan(void)
51 {
52 	char *cp;
53 #define	MAXLINELENGTH	1024
54 	static char line[MAXLINELENGTH];
55 	char subline[MAXLINELENGTH];
56 	char *endp, *last;
57 	int typexx;
58 	long l;
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 					l = strtol(cp, &endp, 10);
79 					if (endp == cp || *endp != '\0' ||
80 					    l < 0 || l >= INT_MAX)
81 						goto bad;
82 					_fs_fstab.fs_freq = l;
83 					if ((cp = strtok_r((char *)NULL,
84 					    ":\n", &last))) {
85 						l = strtol(cp, &endp, 10);
86 						if (endp == cp || *endp != '\0'
87 						    || l < 0 || l >= INT_MAX)
88 							goto bad;
89 						_fs_fstab.fs_passno = l;
90 						return(1);
91 					}
92 				}
93 			}
94 			goto bad;
95 		}
96 /* OLD_STYLE_FSTAB */
97 		_fs_fstab.fs_spec = strtok_r(cp, " \t\n", &last);
98 		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
99 			continue;
100 		_fs_fstab.fs_file = strtok_r((char *)NULL, " \t\n", &last);
101 		_fs_fstab.fs_vfstype = strtok_r((char *)NULL, " \t\n", &last);
102 		_fs_fstab.fs_mntops = strtok_r((char *)NULL, " \t\n", &last);
103 		if (_fs_fstab.fs_mntops == NULL)
104 			goto bad;
105 		_fs_fstab.fs_freq = 0;
106 		_fs_fstab.fs_passno = 0;
107 		if ((cp = strtok_r((char *)NULL, " \t\n", &last)) != NULL) {
108 			l = strtol(cp, &endp, 10);
109 			if (endp == cp || *endp != '\0' || l < 0 ||
110 			    l >= INT_MAX)
111 				goto bad;
112 			_fs_fstab.fs_freq = l;
113 			if ((cp = strtok_r((char *)NULL, " \t\n", &last)) != NULL) {
114 				l = strtol(cp, &endp, 10);
115 				if (endp == cp || *endp != '\0' || l < 0 ||
116 				    l >= INT_MAX)
117 					goto bad;
118 				_fs_fstab.fs_passno = l;
119 			}
120 		}
121 		strlcpy(subline, _fs_fstab.fs_mntops, sizeof subline);
122 		for (typexx = 0, cp = strtok_r(subline, ",", &last); cp;
123 		     cp = strtok_r((char *)NULL, ",", &last)) {
124 			if (strlen(cp) != 2)
125 				continue;
126 			if (!strcmp(cp, FSTAB_RW)) {
127 				_fs_fstab.fs_type = FSTAB_RW;
128 				break;
129 			}
130 			if (!strcmp(cp, FSTAB_RQ)) {
131 				_fs_fstab.fs_type = FSTAB_RQ;
132 				break;
133 			}
134 			if (!strcmp(cp, FSTAB_RO)) {
135 				_fs_fstab.fs_type = FSTAB_RO;
136 				break;
137 			}
138 			if (!strcmp(cp, FSTAB_SW)) {
139 				_fs_fstab.fs_type = FSTAB_SW;
140 				break;
141 			}
142 			if (!strcmp(cp, FSTAB_XX)) {
143 				_fs_fstab.fs_type = FSTAB_XX;
144 				typexx++;
145 				break;
146 			}
147 		}
148 		if (typexx)
149 			continue;
150 		if (cp != NULL)
151 			return(1);
152 
153 bad:		/* no way to distinguish between EOF and syntax error */
154 		error(EFTYPE);
155 	}
156 	/* NOTREACHED */
157 }
158 
159 struct fstab *
getfsent(void)160 getfsent(void)
161 {
162 	if ((!_fs_fp && !setfsent()) || !fstabscan())
163 		return(NULL);
164 	return(&_fs_fstab);
165 }
166 
167 struct fstab *
getfsspec(const char * name)168 getfsspec(const char *name)
169 {
170 	if (setfsent())
171 		while (fstabscan())
172 			if (!strcmp(_fs_fstab.fs_spec, name))
173 				return(&_fs_fstab);
174 	return((struct fstab *)NULL);
175 }
176 
177 struct fstab *
getfsfile(const char * name)178 getfsfile(const char *name)
179 {
180 	if (setfsent())
181 		while (fstabscan())
182 			if (!strcmp(_fs_fstab.fs_file, name))
183 				return(&_fs_fstab);
184 	return((struct fstab *)NULL);
185 }
186 
187 int
setfsent(void)188 setfsent(void)
189 {
190 	struct stat sbuf;
191 
192 	if (_fs_fp) {
193 		rewind(_fs_fp);
194 		return(1);
195 	}
196 
197 	if (stat(_PATH_FSTAB, &sbuf) != 0)
198 		goto fail;
199 	if ((sbuf.st_size == 0) || ((sbuf.st_mode & S_IFMT) != S_IFREG)) {
200 		errno = EFTYPE;
201 		goto fail;
202 	}
203 
204 	if ((_fs_fp = fopen(_PATH_FSTAB, "r")))
205 		return(1);
206 
207 fail:
208 	error(errno);
209 	return(0);
210 }
211 
212 void
endfsent(void)213 endfsent(void)
214 {
215 	if (_fs_fp) {
216 		(void)fclose(_fs_fp);
217 		_fs_fp = NULL;
218 	}
219 }
220 
221 static void
error(int err)222 error(int err)
223 {
224 	struct iovec iov[5];
225 
226 	iov[0].iov_base = "fstab: ";
227 	iov[0].iov_len = 7;
228 	iov[1].iov_base = _PATH_FSTAB;
229 	iov[1].iov_len = sizeof(_PATH_FSTAB) - 1;
230 	iov[2].iov_base =  ": ";
231 	iov[2].iov_len = 2;
232 	iov[3].iov_base = strerror(err);
233 	iov[3].iov_len = strlen(iov[3].iov_base);
234 	iov[4].iov_base = "\n";
235 	iov[4].iov_len = 1;
236 	(void)writev(STDERR_FILENO, iov, 5);
237 }
238