1 /*- 2 * Copyright (c) 2014 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Edward Tomasz Napierala under sponsorship 6 * from the FreeBSD Foundation. 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 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/types.h> 35 #include <sys/event.h> 36 #include <sys/mount.h> 37 #include <sys/time.h> 38 #include <assert.h> 39 #include <errno.h> 40 #include <stdbool.h> 41 #include <stdint.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <unistd.h> 46 #include <libutil.h> 47 48 #include "common.h" 49 50 #define AUTOUNMOUNTD_PIDFILE "/var/run/autounmountd.pid" 51 52 struct automounted_fs { 53 TAILQ_ENTRY(automounted_fs) af_next; 54 time_t af_mount_time; 55 bool af_mark; 56 fsid_t af_fsid; 57 char af_mountpoint[MNAMELEN]; 58 }; 59 60 static TAILQ_HEAD(, automounted_fs) automounted; 61 62 static struct automounted_fs * 63 automounted_find(fsid_t fsid) 64 { 65 struct automounted_fs *af; 66 67 TAILQ_FOREACH(af, &automounted, af_next) { 68 if (af->af_fsid.val[0] == fsid.val[0] && 69 af->af_fsid.val[1] == fsid.val[1]) 70 return (af); 71 } 72 73 return (NULL); 74 } 75 76 static struct automounted_fs * 77 automounted_add(fsid_t fsid, const char *mountpoint) 78 { 79 struct automounted_fs *af; 80 81 af = calloc(sizeof(*af), 1); 82 if (af == NULL) 83 log_err(1, "calloc"); 84 af->af_mount_time = time(NULL); 85 af->af_fsid = fsid; 86 strlcpy(af->af_mountpoint, mountpoint, sizeof(af->af_mountpoint)); 87 88 TAILQ_INSERT_TAIL(&automounted, af, af_next); 89 90 return (af); 91 } 92 93 static void 94 automounted_remove(struct automounted_fs *af) 95 { 96 97 TAILQ_REMOVE(&automounted, af, af_next); 98 free(af); 99 } 100 101 static void 102 refresh_automounted(void) 103 { 104 struct automounted_fs *af, *tmpaf; 105 struct statfs *mntbuf; 106 int i, nitems; 107 108 nitems = getmntinfo(&mntbuf, MNT_WAIT); 109 if (nitems <= 0) 110 log_err(1, "getmntinfo"); 111 112 log_debugx("refreshing list of automounted filesystems"); 113 114 TAILQ_FOREACH(af, &automounted, af_next) 115 af->af_mark = false; 116 117 for (i = 0; i < nitems; i++) { 118 if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) { 119 log_debugx("skipping %s, filesystem type is autofs", 120 mntbuf[i].f_mntonname); 121 continue; 122 } 123 124 if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) { 125 log_debugx("skipping %s, not automounted", 126 mntbuf[i].f_mntonname); 127 continue; 128 } 129 130 af = automounted_find(mntbuf[i].f_fsid); 131 if (af == NULL) { 132 log_debugx("new automounted filesystem found on %s " 133 "(FSID:%d:%d)", mntbuf[i].f_mntonname, 134 mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]); 135 af = automounted_add(mntbuf[i].f_fsid, 136 mntbuf[i].f_mntonname); 137 } else { 138 log_debugx("already known automounted filesystem " 139 "found on %s (FSID:%d:%d)", mntbuf[i].f_mntonname, 140 mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]); 141 } 142 af->af_mark = true; 143 } 144 145 TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) { 146 if (af->af_mark) 147 continue; 148 log_debugx("lost filesystem mounted on %s (FSID:%d:%d)", 149 af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1]); 150 automounted_remove(af); 151 } 152 } 153 154 static int 155 unmount_by_fsid(const fsid_t fsid, const char *mountpoint) 156 { 157 char *fsid_str; 158 int error, ret; 159 160 ret = asprintf(&fsid_str, "FSID:%d:%d", fsid.val[0], fsid.val[1]); 161 if (ret < 0) 162 log_err(1, "asprintf"); 163 164 error = unmount(fsid_str, MNT_BYFSID); 165 if (error != 0) { 166 if (errno == EBUSY) { 167 log_debugx("cannot unmount %s (%s): %s", 168 mountpoint, fsid_str, strerror(errno)); 169 } else { 170 log_warn("cannot unmount %s (%s)", 171 mountpoint, fsid_str); 172 } 173 } 174 175 free(fsid_str); 176 177 return (error); 178 } 179 180 static double 181 expire_automounted(double expiration_time) 182 { 183 struct automounted_fs *af, *tmpaf; 184 time_t now; 185 double mounted_for, mounted_max = 0; 186 int error; 187 188 now = time(NULL); 189 190 log_debugx("expiring automounted filesystems"); 191 192 TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) { 193 mounted_for = difftime(now, af->af_mount_time); 194 195 if (mounted_for < expiration_time) { 196 log_debugx("skipping %s (FSID:%d:%d), mounted " 197 "for %.0f seconds", af->af_mountpoint, 198 af->af_fsid.val[0], af->af_fsid.val[1], 199 mounted_for); 200 201 if (mounted_for > mounted_max) 202 mounted_max = mounted_for; 203 204 continue; 205 } 206 207 log_debugx("filesystem mounted on %s (FSID:%d:%d), " 208 "was mounted for %.0f seconds; unmounting", 209 af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1], 210 mounted_for); 211 error = unmount_by_fsid(af->af_fsid, af->af_mountpoint); 212 if (error != 0) { 213 if (mounted_for > mounted_max) 214 mounted_max = mounted_for; 215 } 216 } 217 218 return (mounted_max); 219 } 220 221 static void 222 usage_autounmountd(void) 223 { 224 225 fprintf(stderr, "usage: autounmountd [-r time][-t time][-dv]\n"); 226 exit(1); 227 } 228 229 static void 230 do_wait(int kq, double sleep_time) 231 { 232 struct timespec timeout; 233 struct kevent unused; 234 int error; 235 236 assert(sleep_time > 0); 237 timeout.tv_sec = sleep_time; 238 timeout.tv_nsec = 0; 239 240 log_debugx("waiting for filesystem event for %.0f seconds", sleep_time); 241 error = kevent(kq, NULL, 0, &unused, 1, &timeout); 242 if (error < 0) 243 log_err(1, "kevent"); 244 245 if (error == 0) 246 log_debugx("timeout reached"); 247 else 248 log_debugx("got filesystem event"); 249 } 250 251 int 252 main_autounmountd(int argc, char **argv) 253 { 254 struct kevent event; 255 struct pidfh *pidfh; 256 pid_t otherpid; 257 const char *pidfile_path = AUTOUNMOUNTD_PIDFILE; 258 int ch, debug = 0, error, kq; 259 double expiration_time = 600, retry_time = 600, mounted_max, sleep_time; 260 bool dont_daemonize = false; 261 262 while ((ch = getopt(argc, argv, "dr:t:v")) != -1) { 263 switch (ch) { 264 case 'd': 265 dont_daemonize = true; 266 debug++; 267 break; 268 case 'r': 269 retry_time = atoi(optarg); 270 break; 271 case 't': 272 expiration_time = atoi(optarg); 273 break; 274 case 'v': 275 debug++; 276 break; 277 case '?': 278 default: 279 usage_autounmountd(); 280 } 281 } 282 argc -= optind; 283 if (argc != 0) 284 usage_autounmountd(); 285 286 if (retry_time <= 0) 287 log_errx(1, "retry time must be greater than zero"); 288 if (expiration_time <= 0) 289 log_errx(1, "expiration time must be greater than zero"); 290 291 log_init(debug); 292 293 pidfh = pidfile_open(pidfile_path, 0600, &otherpid); 294 if (pidfh == NULL) { 295 if (errno == EEXIST) { 296 log_errx(1, "daemon already running, pid: %jd.", 297 (intmax_t)otherpid); 298 } 299 log_err(1, "cannot open or create pidfile \"%s\"", 300 pidfile_path); 301 } 302 303 if (dont_daemonize == false) { 304 if (daemon(0, 0) == -1) { 305 log_warn("cannot daemonize"); 306 pidfile_remove(pidfh); 307 exit(1); 308 } 309 } 310 311 pidfile_write(pidfh); 312 313 TAILQ_INIT(&automounted); 314 315 kq = kqueue(); 316 if (kq < 0) 317 log_err(1, "kqueue"); 318 319 EV_SET(&event, 0, EVFILT_FS, EV_ADD | EV_CLEAR, 0, 0, NULL); 320 error = kevent(kq, &event, 1, NULL, 0, NULL); 321 if (error < 0) 322 log_err(1, "kevent"); 323 324 for (;;) { 325 refresh_automounted(); 326 mounted_max = expire_automounted(expiration_time); 327 if (mounted_max < expiration_time) { 328 sleep_time = difftime(expiration_time, mounted_max); 329 log_debugx("some filesystems expire in %.0f seconds", 330 sleep_time); 331 } else { 332 sleep_time = retry_time; 333 log_debugx("some expired filesystems remain mounted, " 334 "will retry in %.0f seconds", sleep_time); 335 } 336 337 do_wait(kq, sleep_time); 338 } 339 340 return (0); 341 } 342