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1 /*
2  * restorecond
3  *
4  * Copyright (C) 2006-2009 Red Hat
5  * see file 'COPYING' for use and warranty information
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16 .*
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20  * 02111-1307  USA
21  *
22  * Authors:
23  *   Dan Walsh <dwalsh@redhat.com>
24  *
25 */
26 
27 /*
28  * PURPOSE:
29  * This daemon program watches for the creation of files listed in a config file
30  * and makes sure that there security context matches the systems defaults
31  *
32  * USAGE:
33  * restorecond [-d] [-u] [-v] [-f restorecond_file ]
34  *
35  * -d   Run in debug mode
36  * -f   Use alternative restorecond_file
37  * -u   Run in user mode
38  * -v   Run in verbose mode (Report missing files)
39  *
40  * EXAMPLE USAGE:
41  * restorecond
42  *
43  */
44 
45 #define _GNU_SOURCE
46 #include <sys/inotify.h>
47 #include <errno.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <signal.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include "restore.h"
54 #include <sys/types.h>
55 #include <syslog.h>
56 #include <limits.h>
57 #include <pwd.h>
58 #include <sys/stat.h>
59 #include <string.h>
60 #include <stdio.h>
61 #include <fcntl.h>
62 #include "restorecond.h"
63 #include "utmpwatcher.h"
64 
65 const char *homedir;
66 static int master_fd = -1;
67 
68 static const char *server_watch_file  = "/etc/selinux/restorecond.conf";
69 static const char *user_watch_file  = "/etc/selinux/restorecond_user.conf";
70 static const char *watch_file;
71 struct restore_opts r_opts;
72 
73 #include <selinux/selinux.h>
74 
75 int debug_mode = 0;
76 int terminate = 0;
77 int master_wd = -1;
78 int run_as_user = 0;
79 
done(void)80 static void done(void) {
81 	watch_list_free(master_fd);
82 	close(master_fd);
83 	utmpwatcher_free();
84 	selabel_close(r_opts.hnd);
85 }
86 
87 static const char *pidfile = "/var/run/restorecond.pid";
88 
write_pid_file(void)89 static int write_pid_file(void)
90 {
91 	int pidfd, len;
92 	char val[16];
93 
94 	len = snprintf(val, sizeof(val), "%u\n", getpid());
95 	if (len < 0) {
96 		syslog(LOG_ERR, "Pid error (%s)", strerror(errno));
97 		pidfile = 0;
98 		return 1;
99 	}
100 	pidfd = open(pidfile, O_CREAT | O_TRUNC | O_NOFOLLOW | O_WRONLY, 0644);
101 	if (pidfd < 0) {
102 		syslog(LOG_ERR, "Unable to set pidfile (%s)", strerror(errno));
103 		pidfile = 0;
104 		return 1;
105 	}
106 	if (write(pidfd, val, (unsigned int)len) != len) {
107 		syslog(LOG_ERR, "Unable to write to pidfile (%s)", strerror(errno));
108 		return 1;
109 	}
110 	close(pidfd);
111 	return 0;
112 }
113 
114 /*
115  * SIGTERM handler
116  */
term_handler(int s)117 static void term_handler(int s __attribute__ ((unused)))
118 {
119 	terminate = 1;
120 	/* trigger a failure in the watch */
121 	close(master_fd);
122 }
123 
usage(char * program)124 static void usage(char *program)
125 {
126 	printf("%s [-d] [-f restorecond_file ] [-u] [-v] \n", program);
127 }
128 
exitApp(const char * msg)129 void exitApp(const char *msg)
130 {
131 	perror(msg);
132 	exit(-1);
133 }
134 
135 /*
136    Add a file to the watch list.  We are watching for file creation, so we actually
137    put the watch on the directory and then examine all files created in that directory
138    to see if it is one that we are watching.
139 */
140 
main(int argc,char ** argv)141 int main(int argc, char **argv)
142 {
143 	int opt;
144 	struct sigaction sa;
145 
146 	/* If we are not running SELinux then just exit */
147 	if (is_selinux_enabled() != 1)
148 		return 0;
149 
150 	/* Set all options to zero/NULL except for ignore_noent & digest. */
151 	memset(&r_opts, 0, sizeof(r_opts));
152 	r_opts.ignore_noent = SELINUX_RESTORECON_IGNORE_NOENTRY;
153 	r_opts.ignore_digest = SELINUX_RESTORECON_IGNORE_DIGEST;
154 
155 	/* As r_opts.selabel_opt_digest = NULL, no digest will be requested. */
156 	restore_init(&r_opts);
157 
158 	/* Register sighandlers */
159 	sa.sa_flags = 0;
160 	sa.sa_handler = term_handler;
161 	sigemptyset(&sa.sa_mask);
162 	sigaction(SIGTERM, &sa, NULL);
163 
164 	atexit( done );
165 	while ((opt = getopt(argc, argv, "hdf:uv")) > 0) {
166 		switch (opt) {
167 		case 'd':
168 			debug_mode = 1;
169 			break;
170 		case 'f':
171 			watch_file = optarg;
172 			break;
173 		case 'u':
174 			run_as_user = 1;
175 			break;
176 		case 'h':
177 			usage(argv[0]);
178 			exit(0);
179 			break;
180 		case 'v':
181 			r_opts.verbose = SELINUX_RESTORECON_VERBOSE;
182 			break;
183 		case '?':
184 			usage(argv[0]);
185 			exit(-1);
186 		}
187 	}
188 
189 	master_fd = inotify_init();
190 	if (master_fd < 0)
191 		exitApp("inotify_init");
192 
193 	uid_t uid = getuid();
194 	struct passwd *pwd = getpwuid(uid);
195 	if (!pwd)
196 		exitApp("getpwuid");
197 
198 	homedir = pwd->pw_dir;
199 	if (uid != 0) {
200 		if (run_as_user)
201 			return server(master_fd, user_watch_file);
202 		if (start() != 0)
203 			return server(master_fd, user_watch_file);
204 		return 0;
205 	}
206 
207 	watch_file = server_watch_file;
208 	read_config(master_fd, watch_file);
209 
210 	if (!debug_mode) {
211 		if (daemon(0, 0) < 0)
212 			exitApp("daemon");
213 	}
214 
215 	write_pid_file();
216 
217 	while (watch(master_fd, watch_file) == 0) {
218 	};
219 
220 	watch_list_free(master_fd);
221 	close(master_fd);
222 
223 	if (pidfile)
224 		unlink(pidfile);
225 
226 	return 0;
227 }
228