xref: /openbsd/sbin/mount/getmntopts.c (revision df69c215)
1 /*	$OpenBSD: getmntopts.c,v 1.13 2019/06/28 13:32:44 deraadt Exp $	*/
2 /*	$NetBSD: getmntopts.c,v 1.3 1995/03/18 14:56:58 cgd Exp $	*/
3 
4 /*-
5  * Copyright (c) 1994
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/types.h>
34 #include <sys/mount.h>
35 
36 #include <err.h>
37 #include <errno.h>
38 #include <fstab.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <limits.h>
42 
43 #include "mntopts.h"
44 
45 int
getmntopts(const char * optionp,const struct mntopt * m0,int * flagp)46 getmntopts(const char *optionp, const struct mntopt *m0, int *flagp)
47 {
48 	char *p, *q;
49 	union mntval val;
50 	int ret = 0;
51 
52 	p = q = strdup(optionp);
53 	if (p == NULL)
54 		err(1, NULL);
55 	while (p != NULL) {
56 		ret |= getmntopt(&p, &val, m0, flagp);
57 	}
58 	free(q);
59 	return (ret);
60 }
61 
62 int
getmntopt(char ** optionp,union mntval * valuep,const struct mntopt * m0,int * flagp)63 getmntopt(char **optionp, union mntval *valuep, const struct mntopt *m0,
64     int *flagp)
65 {
66 	const struct mntopt *m;
67 	char *opt, *value, *endp;
68 	long l;
69 	int inverse, negative, needval, ret = 0;
70 
71 	/* Pull out the next option. */
72 	do {
73 		if (*optionp == NULL)
74 			return (0);
75 		opt = strsep(optionp, ",");
76 	} while (opt == NULL || *opt == '\0');
77 
78 	/* Check for "no" prefix. */
79 	if (opt[0] == 'n' && opt[1] == 'o') {
80 		negative = 1;
81 		opt += 2;
82 	} else
83 		negative = 0;
84 
85 	/* Stash the value for options with assignments in them. */
86 	if ((value = strchr(opt, '=')) != NULL)
87 		*value++ = '\0';
88 
89 	/* Scan option table. */
90 	for (m = m0; m->m_option != NULL; ++m)
91 		if (strcasecmp(opt, m->m_option) == 0)
92 			break;
93 
94 	/* Save flag, or fail if option is not recognised. */
95 	if (m->m_option) {
96 		needval = (m->m_oflags & (MFLAG_INTVAL|MFLAG_STRVAL)) != 0;
97 		if (needval != (value != NULL) && !(m->m_oflags & MFLAG_OPT))
98 			errx(1, "-o %s: option %s a value", opt,
99 			    needval ? "needs" : "does not need");
100 		inverse = (m->m_oflags & MFLAG_INVERSE) ? 1 : 0;
101 		if (m->m_oflags & MFLAG_SET) {
102 			if (negative == inverse)
103 				*flagp |= m->m_flag;
104 			else
105 				*flagp &= ~m->m_flag;
106 		}
107 		else if (negative == inverse)
108 			ret = m->m_flag;
109 	} else
110 		errx(1, "-o %s: option not supported", opt);
111 
112 	/* Store the value for options with assignments in them. */
113 	if (value != NULL) {
114 		if (m->m_oflags & MFLAG_INTVAL) {
115 			errno = 0;
116 			l = strtol(value, &endp, 10);
117 			if (endp == value || l == -1 || l > INT_MAX ||
118 			    (l == LONG_MAX && errno == ERANGE))
119 				errx(1, "%s: illegal value '%s'",
120 				    opt, value);
121 			valuep->ival = (int)l;
122 		} else
123 			valuep->strval = value;
124 	} else
125 		memset(valuep, 0, sizeof(*valuep));
126 	return (ret);
127 }
128