xref: /freebsd/sbin/mount/getmntopts.c (revision 5e53a4f90f82c4345f277dd87cc9292f26e04a29)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1994
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 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)getmntopts.c	8.3 (Berkeley) 3/29/95";
35 #endif /* not lint */
36 #endif
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/mount.h>
42 #include <sys/stat.h>
43 #include <sys/uio.h>
44 
45 #include <err.h>
46 #include <errno.h>
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 
52 #include "mntopts.h"
53 
54 int getmnt_silent = 0;
55 
56 void
57 getmntopts(const char *options, const struct mntopt *m0, int *flagp,
58 	int *altflagp)
59 {
60 	const struct mntopt *m;
61 	int negative, len;
62 	char *opt, *optbuf, *p;
63 	int *thisflagp;
64 
65 	/* Copy option string, since it is about to be torn asunder... */
66 	if ((optbuf = strdup(options)) == NULL)
67 		err(1, NULL);
68 
69 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
70 		/* Check for "no" prefix. */
71 		if (opt[0] == 'n' && opt[1] == 'o') {
72 			negative = 1;
73 			opt += 2;
74 		} else
75 			negative = 0;
76 
77 		/*
78 		 * for options with assignments in them (ie. quotas)
79 		 * ignore the assignment as it's handled elsewhere
80 		 */
81 		p = strchr(opt, '=');
82 		if (p != NULL)
83 			 *++p = '\0';
84 
85 		/* Scan option table. */
86 		for (m = m0; m->m_option != NULL; ++m) {
87 			len = strlen(m->m_option);
88 			if (strncasecmp(opt, m->m_option, len) == 0)
89 				if (opt[len] == '\0' || opt[len] == '=')
90 					break;
91 		}
92 
93 		/* Save flag, or fail if option is not recognized. */
94 		if (m->m_option) {
95 			thisflagp = m->m_altloc ? altflagp : flagp;
96 			if (negative == m->m_inverse)
97 				*thisflagp |= m->m_flag;
98 			else
99 				*thisflagp &= ~m->m_flag;
100 		} else if (!getmnt_silent) {
101 			errx(1, "-o %s: option not supported", opt);
102 		}
103 	}
104 
105 	free(optbuf);
106 }
107 
108 void
109 rmslashes(char *rrpin, char *rrpout)
110 {
111 	char *rrpoutstart;
112 
113 	*rrpout = *rrpin;
114 	for (rrpoutstart = rrpout; *rrpin != '\0'; *rrpout++ = *rrpin++) {
115 
116 		/* skip all double slashes */
117 		while (*rrpin == '/' && *(rrpin + 1) == '/')
118 			 rrpin++;
119 	}
120 
121 	/* remove trailing slash if necessary */
122 	if (rrpout - rrpoutstart > 1 && *(rrpout - 1) == '/')
123 		*(rrpout - 1) = '\0';
124 	else
125 		*rrpout = '\0';
126 }
127 
128 int
129 checkpath(const char *path, char *resolved)
130 {
131 	struct stat sb;
132 
133 	if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0)
134 		return (1);
135 	if (!S_ISDIR(sb.st_mode)) {
136 		errno = ENOTDIR;
137 		return (1);
138 	}
139 	return (0);
140 }
141 
142 void
143 build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val,
144 	    size_t len)
145 {
146 	int i;
147 
148 	if (*iovlen < 0)
149 		return;
150 	i = *iovlen;
151 	*iov = realloc(*iov, sizeof **iov * (i + 2));
152 	if (*iov == NULL) {
153 		*iovlen = -1;
154 		return;
155 	}
156 	(*iov)[i].iov_base = strdup(name);
157 	(*iov)[i].iov_len = strlen(name) + 1;
158 	i++;
159 	(*iov)[i].iov_base = val;
160 	if (len == (size_t)-1) {
161 		if (val != NULL)
162 			len = strlen(val) + 1;
163 		else
164 			len = 0;
165 	}
166 	(*iov)[i].iov_len = (int)len;
167 	*iovlen = ++i;
168 }
169 
170 /*
171  * This function is needed for compatibility with parameters
172  * which used to use the mount_argf() command for the old mount() syscall.
173  */
174 void
175 build_iovec_argf(struct iovec **iov, int *iovlen, const char *name,
176     const char *fmt, ...)
177 {
178 	va_list ap;
179 	char val[255] = { 0 };
180 
181 	va_start(ap, fmt);
182 	vsnprintf(val, sizeof(val), fmt, ap);
183 	va_end(ap);
184 	build_iovec(iov, iovlen, name, strdup(val), (size_t)-1);
185 }
186 
187 /*
188  * Free the iovec and reset to NULL with zero length.  Useful for calling
189  * nmount in a loop.
190  */
191 void
192 free_iovec(struct iovec **iov, int *iovlen)
193 {
194 	int i;
195 
196 	for (i = 0; i < *iovlen; i++)
197 		free((*iov)[i].iov_base);
198 	free(*iov);
199 }
200