xref: /freebsd/lib/libc/gen/fstab.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 "namespace.h"
33 #include <sys/param.h>
34 #include <sys/mount.h>
35 #include <sys/stat.h>
36 
37 #include <errno.h>
38 #include <fstab.h>
39 #include <paths.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <vis.h>
45 #include "un-namespace.h"
46 
47 static FILE *_fs_fp;
48 static struct fstab _fs_fstab;
49 static int LineNo = 0;
50 static char *path_fstab;
51 static char fstab_path[PATH_MAX];
52 static int fsp_set = 0;
53 
54 static void error(int);
55 static void fixfsfile(void);
56 static int fstabscan(void);
57 
58 void
59 setfstab(const char *file)
60 {
61 
62 	if (file == NULL) {
63 		path_fstab = _PATH_FSTAB;
64 	} else {
65 		strncpy(fstab_path, file, PATH_MAX);
66 		fstab_path[PATH_MAX - 1] = '\0';
67 		path_fstab = fstab_path;
68 	}
69 	fsp_set = 1;
70 
71 	return;
72 }
73 
74 const char *
75 getfstab(void)
76 {
77 
78 	if (fsp_set)
79 		return (path_fstab);
80 	else
81 		return (_PATH_FSTAB);
82 }
83 
84 static void
85 fixfsfile(void)
86 {
87 	static char buf[sizeof(_PATH_DEV) + MNAMELEN];
88 	struct stat sb;
89 	struct statfs sf;
90 
91 	if (_fs_fstab.fs_file != NULL && strcmp(_fs_fstab.fs_file, "/") != 0)
92 		return;
93 	if (statfs("/", &sf) != 0)
94 		return;
95 	if (sf.f_mntfromname[0] == '/')
96 		buf[0] = '\0';
97 	else
98 		strcpy(buf, _PATH_DEV);
99 	strcat(buf, sf.f_mntfromname);
100 	if (stat(buf, &sb) != 0 ||
101 	    (!S_ISBLK(sb.st_mode) && !S_ISCHR(sb.st_mode)))
102 		return;
103 	_fs_fstab.fs_spec = buf;
104 }
105 
106 static int
107 fstabscan(void)
108 {
109 	char *cp, *p;
110 #define	MAXLINELENGTH	1024
111 	static char line[MAXLINELENGTH];
112 	char subline[MAXLINELENGTH];
113 	int typexx;
114 
115 	for (;;) {
116 
117 		if (!(p = fgets(line, sizeof(line), _fs_fp)))
118 			return (0);
119 /* OLD_STYLE_FSTAB */
120 		++LineNo;
121 		if (*line == '#' || *line == '\n')
122 			continue;
123 		if (!strpbrk(p, " \t")) {
124 			_fs_fstab.fs_spec = strsep(&p, ":\n");
125 			_fs_fstab.fs_file = strsep(&p, ":\n");
126 			fixfsfile();
127 			_fs_fstab.fs_type = strsep(&p, ":\n");
128 			if (_fs_fstab.fs_type) {
129 				if (!strcmp(_fs_fstab.fs_type, FSTAB_XX))
130 					continue;
131 				_fs_fstab.fs_mntops = _fs_fstab.fs_type;
132 				_fs_fstab.fs_vfstype =
133 				    strcmp(_fs_fstab.fs_type, FSTAB_SW) ?
134 				    "ufs" : "swap";
135 				if ((cp = strsep(&p, ":\n")) != NULL) {
136 					_fs_fstab.fs_freq = atoi(cp);
137 					if ((cp = strsep(&p, ":\n")) != NULL) {
138 						_fs_fstab.fs_passno = atoi(cp);
139 						return (1);
140 					}
141 				}
142 			}
143 			goto bad;
144 		}
145 /* OLD_STYLE_FSTAB */
146 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
147 			;
148 		_fs_fstab.fs_spec = cp;
149 		if (_fs_fstab.fs_spec == NULL || *_fs_fstab.fs_spec == '#')
150 			continue;
151 		if (strunvis(_fs_fstab.fs_spec, _fs_fstab.fs_spec) < 0)
152 			goto bad;
153 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
154 			;
155 		_fs_fstab.fs_file = cp;
156 		if (_fs_fstab.fs_file == NULL)
157 			goto bad;
158 		if (strunvis(_fs_fstab.fs_file, _fs_fstab.fs_file) < 0)
159 			goto bad;
160 		fixfsfile();
161 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
162 			;
163 		_fs_fstab.fs_vfstype = cp;
164 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
165 			;
166 		_fs_fstab.fs_mntops = cp;
167 		if (_fs_fstab.fs_mntops == NULL)
168 			goto bad;
169 		_fs_fstab.fs_freq = 0;
170 		_fs_fstab.fs_passno = 0;
171 		while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
172 			;
173 		if (cp != NULL) {
174 			_fs_fstab.fs_freq = atoi(cp);
175 			while ((cp = strsep(&p, " \t\n")) != NULL && *cp == '\0')
176 				;
177 			if (cp != NULL)
178 				_fs_fstab.fs_passno = atoi(cp);
179 		}
180 		(void)strlcpy(subline, _fs_fstab.fs_mntops, sizeof(subline));
181 		p = subline;
182 		for (typexx = 0, cp = strsep(&p, ","); cp;
183 		     cp = strsep(&p, ",")) {
184 			if (strlen(cp) != 2)
185 				continue;
186 			if (!strcmp(cp, FSTAB_RW)) {
187 				_fs_fstab.fs_type = FSTAB_RW;
188 				break;
189 			}
190 			if (!strcmp(cp, FSTAB_RQ)) {
191 				_fs_fstab.fs_type = FSTAB_RQ;
192 				break;
193 			}
194 			if (!strcmp(cp, FSTAB_RO)) {
195 				_fs_fstab.fs_type = FSTAB_RO;
196 				break;
197 			}
198 			if (!strcmp(cp, FSTAB_SW)) {
199 				_fs_fstab.fs_type = FSTAB_SW;
200 				break;
201 			}
202 			if (!strcmp(cp, FSTAB_XX)) {
203 				_fs_fstab.fs_type = FSTAB_XX;
204 				typexx++;
205 				break;
206 			}
207 		}
208 		if (typexx)
209 			continue;
210 		if (cp != NULL)
211 			return (1);
212 
213 bad:		/* no way to distinguish between EOF and syntax error */
214 		error(EFTYPE);
215 	}
216 	/* NOTREACHED */
217 }
218 
219 struct fstab *
220 getfsent(void)
221 {
222 
223 	if ((!_fs_fp && !setfsent()) || !fstabscan())
224 		return (NULL);
225 	return (&_fs_fstab);
226 }
227 
228 struct fstab *
229 getfsspec(const char *name)
230 {
231 
232 	if (setfsent())
233 		while (fstabscan())
234 			if (!strcmp(_fs_fstab.fs_spec, name))
235 				return (&_fs_fstab);
236 	return (NULL);
237 }
238 
239 struct fstab *
240 getfsfile(const char *name)
241 {
242 
243 	if (setfsent())
244 		while (fstabscan())
245 			if (!strcmp(_fs_fstab.fs_file, name))
246 				return (&_fs_fstab);
247 	return (NULL);
248 }
249 
250 int
251 setfsent(void)
252 {
253 	if (_fs_fp) {
254 		rewind(_fs_fp);
255 		LineNo = 0;
256 		return (1);
257 	}
258 	if (fsp_set == 0)
259 		setfstab(secure_getenv("PATH_FSTAB"));
260 	if ((_fs_fp = fopen(path_fstab, "re")) != NULL) {
261 		LineNo = 0;
262 		return (1);
263 	}
264 	error(errno);
265 	return (0);
266 }
267 
268 void
269 endfsent(void)
270 {
271 
272 	if (_fs_fp) {
273 		(void)fclose(_fs_fp);
274 		_fs_fp = NULL;
275 	}
276 
277 	fsp_set = 0;
278 }
279 
280 static void
281 error(int err)
282 {
283 	char *p;
284 	char num[30];
285 
286 	(void)_write(STDERR_FILENO, "fstab: ", 7);
287 	(void)_write(STDERR_FILENO, path_fstab, strlen(path_fstab));
288 	(void)_write(STDERR_FILENO, ":", 1);
289 	sprintf(num, "%d: ", LineNo);
290 	(void)_write(STDERR_FILENO, num, strlen(num));
291 	p = strerror(err);
292 	(void)_write(STDERR_FILENO, p, strlen(p));
293 	(void)_write(STDERR_FILENO, "\n", 1);
294 }
295