1 /*
2  * Copyright (c) 2004 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Chris Pressey <cpressey@catseye.mine.nu>.
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  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 
36 /*
37  * fspred.c
38  * Filesystem predicates.
39  * $Id: fspred.c,v 1.3 2005/02/10 03:33:49 cpressey Exp $
40  */
41 
42 #include <sys/stat.h>
43 #include <sys/param.h>
44 #include <sys/ucred.h>
45 #include <sys/mount.h>
46 
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #include "fspred.h"
54 
55 /** PREDICATES **/
56 
57 static void
58 vstatmod(mode_t *m, int *error, const char *fmt, va_list args)
59 {
60 	char *filename;
61 	struct stat sb;
62 
63 	memset(&sb, 0, sizeof(sb));
64 
65 	vasprintf(&filename, fmt, args);
66 
67 	*error = stat(filename, &sb);
68 	free(filename);
69 
70 	if (*error)
71 		*m = 0;	/* Do not leak fake mode */
72 	else
73 		*m = sb.st_mode;
74 }
75 
76 int
77 is_dir(const char *fmt, ...)
78 {
79 	va_list args;
80 	int error;
81 	mode_t m;
82 
83 	va_start(args, fmt);
84 	vstatmod(&m, &error, fmt, args);
85 	va_end(args);
86 
87 	if (error == 0)
88 		return(S_ISDIR(m));
89 	else
90 		return(0);
91 }
92 
93 int
94 is_file(const char *fmt, ...)
95 {
96 	va_list args;
97 	int error;
98 	mode_t m;
99 
100 	va_start(args, fmt);
101 	vstatmod(&m, &error, fmt, args);
102 	va_end(args);
103 
104 	if (error == 0)
105 		return(S_ISREG(m) );
106 	else
107 		return(0);
108 
109 }
110 
111 int
112 is_program(const char *fmt, ...)
113 {
114 	char *filename;
115 	struct stat sb;
116 	va_list args;
117 	int error;
118 	uid_t uid;
119 	gid_t gid;
120 
121 	va_start(args, fmt);
122 	vasprintf(&filename, fmt, args);
123 	va_end(args);
124 
125 	error = stat(filename, &sb);
126 	free(filename);
127 
128 	uid = getuid();
129 	gid = getgid();
130 
131 	if (error == 0) {
132 		/* Try to be more precise when identifying executable programs.
133 		 * Still this is subject to race conditions where the regular file
134 		 * might have its permissions/ownership changed during the test and
135 		 * thus provide inaccurate results.
136 		 * Also, effective uid/gid is not being checked.
137 		 */
138 		if ((S_ISREG(sb.st_mode)) &&
139 		    ((sb.st_uid == uid && sb.st_mode & S_IXUSR) ||
140 			(sb.st_gid == gid && sb.st_mode & S_IXGRP) ||
141 			(sb.st_mode & S_IXOTH))) {
142 			return 1;
143 		}
144 	}
145 
146 	return 0;
147 }
148 
149 int
150 is_device(const char *fmt, ...)
151 {
152 	va_list args;
153 	int error;
154 	mode_t m;
155 
156 	va_start(args, fmt);
157 	vstatmod(&m, &error, fmt, args);
158 	va_end(args);
159 
160 	if (error == 0)
161 		return(S_ISBLK(m) || S_ISCHR(m));
162 	else
163 		return(0);
164 }
165 
166 int
167 is_named_pipe(const char *fmt, ...)
168 {
169 	va_list args;
170 	int error;
171 	mode_t m;
172 
173 	va_start(args, fmt);
174 	vstatmod(&m, &error, fmt, args);
175 	va_end(args);
176 
177 	if (error == 0)
178 		return(S_ISFIFO(m));
179 	else
180 		return(0);
181 }
182 
183 int
184 is_mountpoint_mounted(const char *mtpt)
185 {
186 	struct statfs *mt_array, *mt_ptr;
187 	int count;
188 
189 	count = getmntinfo(&mt_array, MNT_WAIT);
190 	for (mt_ptr = mt_array; count > 0; mt_ptr++, count--) {
191 		if (strncmp(mt_ptr->f_mntonname, mtpt, PATH_MAX) == 0)
192 			return(1);
193 	}
194 	return(0);
195 }
196 
197 int
198 is_device_mounted(const char *device)
199 {
200 	struct statfs *mt_array, *mt_ptr;
201 	int count;
202 
203 	count = getmntinfo(&mt_array, MNT_WAIT);
204 	for (mt_ptr = mt_array; count > 0; mt_ptr++, count--) {
205 		if (strncmp(mt_ptr->f_mntfromname, device, PATH_MAX) == 0)
206 			return(1);
207 	}
208 	return(0);
209 }
210 
211 int
212 is_any_slice_mounted(const char *diskdev)
213 {
214 	struct statfs *mt_array, *mt_ptr;
215 	int count;
216 
217 	count = getmntinfo(&mt_array, MNT_WAIT);
218 	for (mt_ptr = mt_array; count > 0; mt_ptr++, count--) {
219 		if (strstr(mt_ptr->f_mntfromname, diskdev) ==
220 		    mt_ptr->f_mntfromname)
221 			return(1);
222 	}
223 	return(0);
224 }
225