xref: /freebsd/lib/libc/gen/fstab.c (revision a31c8b58b5d63ffa1fac2bb225db2c6fb42a6c2e)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)fstab.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "namespace.h"
37 #include <sys/param.h>
38 #include <sys/mount.h>
39 #include <sys/stat.h>
40 
41 #include <errno.h>
42 #include <fcntl.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 #include "un-namespace.h"
50 
51 static FILE *_fs_fp;
52 static struct fstab _fs_fstab;
53 static int LineNo = 0;
54 static char *path_fstab;
55 static char fstab_path[PATH_MAX];
56 static int fsp_set = 0;
57 
58 static void error(int);
59 static void fixfsfile(void);
60 static int fstabscan(void);
61 
62 void
63 setfstab(const char *file)
64 {
65 
66 	if (file == NULL) {
67 		path_fstab = _PATH_FSTAB;
68 	} else {
69 		strncpy(fstab_path, file, PATH_MAX);
70 		fstab_path[PATH_MAX - 1] = '\0';
71 		path_fstab = fstab_path;
72 	}
73 	fsp_set = 1;
74 
75 	return;
76 }
77 
78 const char *
79 getfstab(void)
80 {
81 
82 	if (fsp_set)
83 		return (path_fstab);
84 	else
85 		return (_PATH_FSTAB);
86 }
87 
88 static void
89 fixfsfile(void)
90 {
91 	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
92 	struct stat sb;
93 	struct statfs sf;
94 
95 	if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
96 		return;
97 	if (statfs("/", &sf) != 0)
98 		return;
99 	if (sf.f_mntfromname[0] == '/')
100 		buf[0] = '\0';
101 	else
102 		strcpy(buf, _PATH_DEV);
103 	strcat(buf, sf.f_mntfromname);
104 	if (stat(buf, &sb) != 0 ||
105 	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
106 		return;
107 	_fs_fstab.fs_spec = buf;
108 }
109 
110 static int
111 fstabscan(void)
112 {
113 	char *cp, *p;
114 #define	MAXLINELENGTH	1024
115 	static char line[MAXLINELENGTH];
116 	char subline[MAXLINELENGTH];
117 	int typexx;
118 
119 	for (;;) {
120 
121 		if (!(p = fgets(line, sizeof(line), _fs_fp)))
122 			return (0);
123 /* OLD_STYLE_FSTAB */
124 		++LineNo;
125 		if (*line == '#' || *line == '\n')
126 			continue;
127 		if (!strpbrk(p, " \t")) {
128 			_fs_fstab.fs_spec = strsep(&p, ":\n");
129 			_fs_fstab.fs_file = strsep(&p, ":\n");
130 			fixfsfile();
131 			_fs_fstab.fs_type = strsep(&p, ":\n");
132 			if (_fs_fstab.fs_type) {
133 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
134 					continue;
135 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
136 				_fs_fstab.fs_vfstype =
137 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
138 				    "ufs" : "swap";
139 				if ((cp = strsep(&p, ":\n")) != NULL) {
140 					_fs_fstab.fs_freq = atoi(cp);
141 					if ((cp = strsep(&p, ":\n")) != NULL) {
142 						_fs_fstab.fs_passno = atoi(cp);
143 						return (1);
144 					}
145 				}
146 			}
147 			goto bad;
148 		}
149 /* OLD_STYLE_FSTAB */
150 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
151 			;
152 		_fs_fstab.fs_spec = cp;
153 		if (!_fs_fstab.fs_spec || *_fs_fstab.fs_spec == '#')
154 			continue;
155 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
156 			;
157 		_fs_fstab.fs_file = cp;
158 		fixfsfile();
159 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
160 			;
161 		_fs_fstab.fs_vfstype = cp;
162 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
163 			;
164 		_fs_fstab.fs_mntops = cp;
165 		if (_fs_fstab.fs_mntops == NULL)
166 			goto bad;
167 		_fs_fstab.fs_freq = 0;
168 		_fs_fstab.fs_passno = 0;
169 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
170 			;
171 		if (cp != NULL) {
172 			_fs_fstab.fs_freq = atoi(cp);
173 			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
174 				;
175 			if (cp != NULL)
176 				_fs_fstab.fs_passno = atoi(cp);
177 		}
178 		strcpy(subline, _fs_fstab.fs_mntops);
179 		p = subline;
180 		for (typexx = 0, cp = strsep(&p, ","); cp;
181 		     cp = strsep(&p, ",")) {
182 			if (strlen(cp) != 2)
183 				continue;
184 			if (!strcmp(cp, FSTAB_RW)) {
185 				_fs_fstab.fs_type = FSTAB_RW;
186 				break;
187 			}
188 			if (!strcmp(cp, FSTAB_RQ)) {
189 				_fs_fstab.fs_type = FSTAB_RQ;
190 				break;
191 			}
192 			if (!strcmp(cp, FSTAB_RO)) {
193 				_fs_fstab.fs_type = FSTAB_RO;
194 				break;
195 			}
196 			if (!strcmp(cp, FSTAB_SW)) {
197 				_fs_fstab.fs_type = FSTAB_SW;
198 				break;
199 			}
200 			if (!strcmp(cp, FSTAB_XX)) {
201 				_fs_fstab.fs_type = FSTAB_XX;
202 				typexx++;
203 				break;
204 			}
205 		}
206 		if (typexx)
207 			continue;
208 		if (cp != NULL)
209 			return (1);
210 
211 bad:		/* no way to distinguish between EOF and syntax error */
212 		error(EFTYPE);
213 	}
214 	/* NOTREACHED */
215 }
216 
217 struct fstab *
218 getfsent(void)
219 {
220 
221 	if ((!_fs_fp && !setfsent()) || !fstabscan())
222 		return (NULL);
223 	return (&_fs_fstab);
224 }
225 
226 struct fstab *
227 getfsspec(const char *name)
228 {
229 
230 	if (setfsent())
231 		while (fstabscan())
232 			if (!strcmp(_fs_fstab.fs_spec, name))
233 				return (&_fs_fstab);
234 	return (NULL);
235 }
236 
237 struct fstab *
238 getfsfile(const char *name)
239 {
240 
241 	if (setfsent())
242 		while (fstabscan())
243 			if (!strcmp(_fs_fstab.fs_file, name))
244 				return (&_fs_fstab);
245 	return (NULL);
246 }
247 
248 int
249 setfsent(void)
250 {
251 	int fd;
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 	fd = _open(path_fstab, O_RDONLY | O_CLOEXEC);
265 	if (fd == -1) {
266 		error(errno);
267 		return (0);
268 	}
269 	_fs_fp = fdopen(fd, "r");
270 	if (_fs_fp  != NULL) {
271 		LineNo = 0;
272 		return (1);
273 	}
274 	error(errno);
275 	_close(fd);
276 	return (0);
277 }
278 
279 void
280 endfsent(void)
281 {
282 
283 	if (_fs_fp) {
284 		(void)fclose(_fs_fp);
285 		_fs_fp = NULL;
286 	}
287 
288 	fsp_set = 0;
289 }
290 
291 static void
292 error(int err)
293 {
294 	char *p;
295 	char num[30];
296 
297 	(void)_write(STDERR_FILENO, "fstab: ", 7);
298 	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
299 	(void)_write(STDERR_FILENO, ":", 1);
300 	sprintf(num, "%d: ", LineNo);
301 	(void)_write(STDERR_FILENO, num, strlen(num));
302 	p = strerror(err);
303 	(void)_write(STDERR_FILENO, p, strlen(p));
304 	(void)_write(STDERR_FILENO, "\n", 1);
305 }
306