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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 (at) 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 
     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 = "/run/restorecond.pid";
     88 
     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 		close(pidfd);
    109 		return 1;
    110 	}
    111 	close(pidfd);
    112 	return 0;
    113 }
    114 
    115 /*
    116  * SIGTERM handler
    117  */
    118 static void term_handler(int s __attribute__ ((unused)))
    119 {
    120 	terminate = 1;
    121 	/* trigger a failure in the watch */
    122 	close(master_fd);
    123 }
    124 
    125 static void usage(char *program)
    126 {
    127 	printf("%s [-d] [-f restorecond_file ] [-u] [-v] \n", program);
    128 }
    129 
    130 void exitApp(const char *msg)
    131 {
    132 	perror(msg);
    133 	exit(-1);
    134 }
    135 
    136 /*
    137    Add a file to the watch list.  We are watching for file creation, so we actually
    138    put the watch on the directory and then examine all files created in that directory
    139    to see if it is one that we are watching.
    140 */
    141 
    142 int main(int argc, char **argv)
    143 {
    144 	int opt;
    145 	struct sigaction sa;
    146 
    147 	/* If we are not running SELinux then just exit */
    148 	if (is_selinux_enabled() != 1)
    149 		return 0;
    150 
    151 	watch_file = server_watch_file;
    152 
    153 	/* Set all options to zero/NULL except for ignore_noent & digest. */
    154 	memset(&r_opts, 0, sizeof(r_opts));
    155 	r_opts.ignore_noent = SELINUX_RESTORECON_IGNORE_NOENTRY;
    156 	r_opts.ignore_digest = SELINUX_RESTORECON_IGNORE_DIGEST;
    157 
    158 	/* As r_opts.selabel_opt_digest = NULL, no digest will be requested. */
    159 	restore_init(&r_opts);
    160 
    161 	/* Register sighandlers */
    162 	sa.sa_flags = 0;
    163 	sa.sa_handler = term_handler;
    164 	sigemptyset(&sa.sa_mask);
    165 	sigaction(SIGTERM, &sa, NULL);
    166 
    167 	atexit( done );
    168 	while ((opt = getopt(argc, argv, "hdf:uv")) > 0) {
    169 		switch (opt) {
    170 		case 'd':
    171 			debug_mode = 1;
    172 			break;
    173 		case 'f':
    174 			watch_file = optarg;
    175 			break;
    176 		case 'u':
    177 			run_as_user = 1;
    178 			break;
    179 		case 'h':
    180 			usage(argv[0]);
    181 			exit(0);
    182 			break;
    183 		case 'v':
    184 			r_opts.verbose = SELINUX_RESTORECON_VERBOSE;
    185 			break;
    186 		case '?':
    187 			usage(argv[0]);
    188 			exit(-1);
    189 		}
    190 	}
    191 
    192 	master_fd = inotify_init();
    193 	if (master_fd < 0)
    194 		exitApp("inotify_init");
    195 
    196 	uid_t uid = getuid();
    197 	struct passwd *pwd = getpwuid(uid);
    198 	if (!pwd)
    199 		exitApp("getpwuid");
    200 
    201 	homedir = pwd->pw_dir;
    202 	if (uid != 0) {
    203 		if (run_as_user)
    204 			return server(master_fd, user_watch_file);
    205 		if (start() != 0)
    206 			return server(master_fd, user_watch_file);
    207 		return 0;
    208 	}
    209 
    210 	read_config(master_fd, watch_file);
    211 
    212 	if (!debug_mode) {
    213 		if (daemon(0, 0) < 0)
    214 			exitApp("daemon");
    215 	}
    216 
    217 	write_pid_file();
    218 
    219 	while (watch(master_fd, watch_file) == 0) {
    220 	}
    221 
    222 	watch_list_free(master_fd);
    223 	close(master_fd);
    224 
    225 	if (pidfile)
    226 		unlink(pidfile);
    227 
    228 	return 0;
    229 }
    230