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/time.h> 36 #include <sys/ioctl.h> 37 #include <sys/param.h> 38 #include <sys/linker.h> 39 #include <sys/mount.h> 40 #include <sys/socket.h> 41 #include <sys/stat.h> 42 #include <sys/wait.h> 43 #include <sys/utsname.h> 44 #include <assert.h> 45 #include <ctype.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <libgen.h> 49 #include <netdb.h> 50 #include <signal.h> 51 #include <stdbool.h> 52 #include <stdint.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 #include <libutil.h> 59 60 #include "autofs_ioctl.h" 61 62 #include "common.h" 63 64 #define AUTOMOUNTD_PIDFILE "/var/run/automountd.pid" 65 66 static int nchildren = 0; 67 static int autofs_fd; 68 static int request_id; 69 70 static void 71 done(int request_error) 72 { 73 struct autofs_daemon_done add; 74 int error; 75 76 memset(&add, 0, sizeof(add)); 77 add.add_id = request_id; 78 add.add_error = request_error; 79 80 log_debugx("completing request %d with error %d", 81 request_id, request_error); 82 83 error = ioctl(autofs_fd, AUTOFSDONE, &add); 84 if (error != 0) { 85 /* 86 * Do this instead of log_err() to avoid calling 87 * done() again with error, from atexit handler. 88 */ 89 log_warn("AUTOFSDONE"); 90 } 91 quick_exit(1); 92 } 93 94 /* 95 * Remove "fstype=whatever" from optionsp and return the "whatever" part. 96 */ 97 static char * 98 pick_option(const char *option, char **optionsp) 99 { 100 char *tofree, *pair, *newoptions; 101 char *picked = NULL; 102 bool first = true; 103 104 tofree = *optionsp; 105 106 newoptions = calloc(strlen(*optionsp) + 1, 1); 107 if (newoptions == NULL) 108 log_err(1, "calloc"); 109 110 while ((pair = strsep(optionsp, ",")) != NULL) { 111 /* 112 * XXX: strncasecmp(3) perhaps? 113 */ 114 if (strncmp(pair, option, strlen(option)) == 0) { 115 picked = checked_strdup(pair + strlen(option)); 116 } else { 117 if (first == false) 118 strcat(newoptions, ","); 119 else 120 first = false; 121 strcat(newoptions, pair); 122 } 123 } 124 125 free(tofree); 126 *optionsp = newoptions; 127 128 return (picked); 129 } 130 131 static void 132 create_subtree(const struct node *node, bool incomplete) 133 { 134 const struct node *child; 135 char *path; 136 bool wildcard_found = false; 137 138 /* 139 * Skip wildcard nodes. 140 */ 141 if (strcmp(node->n_key, "*") == 0) 142 return; 143 144 path = node_path(node); 145 log_debugx("creating subtree at %s", path); 146 create_directory(path); 147 148 if (incomplete) { 149 TAILQ_FOREACH(child, &node->n_children, n_next) { 150 if (strcmp(child->n_key, "*") == 0) { 151 wildcard_found = true; 152 break; 153 } 154 } 155 156 if (wildcard_found) { 157 log_debugx("node %s contains wildcard entry; " 158 "not creating its subdirectories due to -d flag", 159 path); 160 free(path); 161 return; 162 } 163 } 164 165 free(path); 166 167 TAILQ_FOREACH(child, &node->n_children, n_next) 168 create_subtree(child, incomplete); 169 } 170 171 static void 172 exit_callback(void) 173 { 174 175 done(EIO); 176 } 177 178 static void 179 handle_request(const struct autofs_daemon_request *adr, char *cmdline_options, 180 bool incomplete_hierarchy) 181 { 182 const char *map; 183 struct node *root, *parent, *node; 184 FILE *f; 185 char *options, *fstype, *nobrowse, *retrycnt, *tmp; 186 int error; 187 188 log_debugx("got request %d: from %s, path %s, prefix \"%s\", " 189 "key \"%s\", options \"%s\"", adr->adr_id, adr->adr_from, 190 adr->adr_path, adr->adr_prefix, adr->adr_key, adr->adr_options); 191 192 /* 193 * Try to notify the kernel about any problems. 194 */ 195 request_id = adr->adr_id; 196 atexit(exit_callback); 197 198 if (strncmp(adr->adr_from, "map ", 4) != 0) { 199 log_errx(1, "invalid mountfrom \"%s\"; failing request", 200 adr->adr_from); 201 } 202 203 map = adr->adr_from + 4; /* 4 for strlen("map "); */ 204 root = node_new_root(); 205 if (adr->adr_prefix[0] == '\0' || strcmp(adr->adr_prefix, "/") == 0) { 206 parent = root; 207 } else { 208 parent = node_new_map(root, checked_strdup(adr->adr_prefix), 209 checked_strdup(adr->adr_options), checked_strdup(map), 210 checked_strdup("[kernel request]"), lineno); 211 } 212 parse_map(parent, map, adr->adr_key[0] != '\0' ? adr->adr_key : NULL); 213 if (adr->adr_key[0] != '\0') 214 node_expand_wildcard(root, adr->adr_key); 215 node = node_find(root, adr->adr_path); 216 if (node == NULL) { 217 log_errx(1, "map %s does not contain key for \"%s\"; " 218 "failing mount", map, adr->adr_path); 219 } 220 221 if (node->n_location == NULL) { 222 log_debugx("found node defined at %s:%d; not a mountpoint", 223 node->n_config_file, node->n_config_line); 224 225 options = node_options(node); 226 227 /* 228 * Prepend options passed via automountd(8) command line. 229 */ 230 if (cmdline_options != NULL) { 231 options = 232 separated_concat(cmdline_options, options, ','); 233 } 234 235 nobrowse = pick_option("nobrowse", &options); 236 if (nobrowse != NULL && adr->adr_key[0] == '\0') { 237 log_debugx("skipping map %s due to \"nobrowse\" " 238 "option; exiting", map); 239 done(0); 240 241 /* 242 * Exit without calling exit_callback(). 243 */ 244 quick_exit(0); 245 } 246 247 /* 248 * Not a mountpoint; create directories in the autofs mount 249 * and complete the request. 250 */ 251 create_subtree(node, incomplete_hierarchy); 252 253 if (incomplete_hierarchy && adr->adr_key[0] != '\0') { 254 /* 255 * We still need to create the single subdirectory 256 * user is trying to access. 257 */ 258 tmp = separated_concat(adr->adr_path, 259 adr->adr_key, '/'); 260 node = node_find(root, tmp); 261 if (node != NULL) 262 create_subtree(node, false); 263 } 264 265 log_debugx("nothing to mount; exiting"); 266 done(0); 267 268 /* 269 * Exit without calling exit_callback(). 270 */ 271 quick_exit(0); 272 } 273 274 log_debugx("found node defined at %s:%d; it is a mountpoint", 275 node->n_config_file, node->n_config_line); 276 277 node_expand_ampersand(node, 278 adr->adr_key[0] != '\0' ? adr->adr_key : NULL); 279 error = node_expand_defined(node); 280 if (error != 0) { 281 log_errx(1, "variable expansion failed for %s; " 282 "failing mount", adr->adr_path); 283 } 284 285 options = node_options(node); 286 287 /* 288 * Prepend options passed via automountd(8) command line. 289 */ 290 if (cmdline_options != NULL) 291 options = separated_concat(cmdline_options, options, ','); 292 293 /* 294 * Append "automounted". 295 */ 296 options = separated_concat(options, "automounted", ','); 297 298 /* 299 * Remove "nobrowse", mount(8) doesn't understand it. 300 */ 301 pick_option("nobrowse", &options); 302 303 /* 304 * Figure out fstype. 305 */ 306 fstype = pick_option("fstype=", &options); 307 if (fstype == NULL) { 308 log_debugx("fstype not specified in options; " 309 "defaulting to \"nfs\""); 310 fstype = checked_strdup("nfs"); 311 } 312 313 if (strcmp(fstype, "nfs") == 0) { 314 /* 315 * The mount_nfs(8) command defaults to retry undefinitely. 316 * We do not want that behaviour, because it leaves mount_nfs(8) 317 * instances and automountd(8) children hanging forever. 318 * Disable retries unless the option was passed explicitly. 319 */ 320 retrycnt = pick_option("retrycnt=", &options); 321 if (retrycnt == NULL) { 322 log_debugx("retrycnt not specified in options; " 323 "defaulting to 1"); 324 options = separated_concat(options, 325 separated_concat("retrycnt", "1", '='), ','); 326 } else { 327 options = separated_concat(options, 328 separated_concat("retrycnt", retrycnt, '='), ','); 329 } 330 } 331 332 f = auto_popen("mount", "-t", fstype, "-o", options, 333 node->n_location, adr->adr_path, NULL); 334 assert(f != NULL); 335 error = auto_pclose(f); 336 if (error != 0) 337 log_errx(1, "mount failed"); 338 339 log_debugx("mount done; exiting"); 340 done(0); 341 342 /* 343 * Exit without calling exit_callback(). 344 */ 345 quick_exit(0); 346 } 347 348 static int 349 wait_for_children(bool block) 350 { 351 pid_t pid; 352 int status; 353 int num = 0; 354 355 for (;;) { 356 /* 357 * If "block" is true, wait for at least one process. 358 */ 359 if (block && num == 0) 360 pid = wait4(-1, &status, 0, NULL); 361 else 362 pid = wait4(-1, &status, WNOHANG, NULL); 363 if (pid <= 0) 364 break; 365 if (WIFSIGNALED(status)) { 366 log_warnx("child process %d terminated with signal %d", 367 pid, WTERMSIG(status)); 368 } else if (WEXITSTATUS(status) != 0) { 369 log_warnx("child process %d terminated with exit status %d", 370 pid, WEXITSTATUS(status)); 371 } else { 372 log_debugx("child process %d terminated gracefully", pid); 373 } 374 num++; 375 } 376 377 return (num); 378 } 379 380 static void 381 usage_automountd(void) 382 { 383 384 fprintf(stderr, "usage: automountd [-D name=value][-m maxproc]" 385 "[-o opts][-Tidv]\n"); 386 exit(1); 387 } 388 389 int 390 main_automountd(int argc, char **argv) 391 { 392 struct pidfh *pidfh; 393 pid_t pid, otherpid; 394 const char *pidfile_path = AUTOMOUNTD_PIDFILE; 395 char *options = NULL; 396 struct autofs_daemon_request request; 397 int ch, debug = 0, error, maxproc = 30, retval, saved_errno; 398 bool dont_daemonize = false, incomplete_hierarchy = false; 399 400 defined_init(); 401 402 while ((ch = getopt(argc, argv, "D:Tdim:o:v")) != -1) { 403 switch (ch) { 404 case 'D': 405 defined_parse_and_add(optarg); 406 break; 407 case 'T': 408 /* 409 * For compatibility with other implementations, 410 * such as OS X. 411 */ 412 debug++; 413 break; 414 case 'd': 415 dont_daemonize = true; 416 debug++; 417 break; 418 case 'i': 419 incomplete_hierarchy = true; 420 break; 421 case 'm': 422 maxproc = atoi(optarg); 423 break; 424 case 'o': 425 if (options == NULL) { 426 options = checked_strdup(optarg); 427 } else { 428 options = 429 separated_concat(options, optarg, ','); 430 } 431 break; 432 case 'v': 433 debug++; 434 break; 435 case '?': 436 default: 437 usage_automountd(); 438 } 439 } 440 argc -= optind; 441 if (argc != 0) 442 usage_automountd(); 443 444 log_init(debug); 445 446 pidfh = pidfile_open(pidfile_path, 0600, &otherpid); 447 if (pidfh == NULL) { 448 if (errno == EEXIST) { 449 log_errx(1, "daemon already running, pid: %jd.", 450 (intmax_t)otherpid); 451 } 452 log_err(1, "cannot open or create pidfile \"%s\"", 453 pidfile_path); 454 } 455 456 autofs_fd = open(AUTOFS_PATH, O_RDWR | O_CLOEXEC); 457 if (autofs_fd < 0 && errno == ENOENT) { 458 saved_errno = errno; 459 retval = kldload("autofs"); 460 if (retval != -1) 461 autofs_fd = open(AUTOFS_PATH, O_RDWR | O_CLOEXEC); 462 else 463 errno = saved_errno; 464 } 465 if (autofs_fd < 0) 466 log_err(1, "failed to open %s", AUTOFS_PATH); 467 468 if (dont_daemonize == false) { 469 if (daemon(0, 0) == -1) { 470 log_warn("cannot daemonize"); 471 pidfile_remove(pidfh); 472 exit(1); 473 } 474 } else { 475 lesser_daemon(); 476 } 477 478 pidfile_write(pidfh); 479 480 for (;;) { 481 log_debugx("waiting for request from the kernel"); 482 483 memset(&request, 0, sizeof(request)); 484 error = ioctl(autofs_fd, AUTOFSREQUEST, &request); 485 if (error != 0) { 486 if (errno == EINTR) { 487 nchildren -= wait_for_children(false); 488 assert(nchildren >= 0); 489 continue; 490 } 491 492 log_err(1, "AUTOFSREQUEST"); 493 } 494 495 if (dont_daemonize) { 496 log_debugx("not forking due to -d flag; " 497 "will exit after servicing a single request"); 498 } else { 499 nchildren -= wait_for_children(false); 500 assert(nchildren >= 0); 501 502 while (maxproc > 0 && nchildren >= maxproc) { 503 log_debugx("maxproc limit of %d child processes hit; " 504 "waiting for child process to exit", maxproc); 505 nchildren -= wait_for_children(true); 506 assert(nchildren >= 0); 507 } 508 log_debugx("got request; forking child process #%d", 509 nchildren); 510 nchildren++; 511 512 pid = fork(); 513 if (pid < 0) 514 log_err(1, "fork"); 515 if (pid > 0) 516 continue; 517 } 518 519 pidfile_close(pidfh); 520 handle_request(&request, options, incomplete_hierarchy); 521 } 522 523 pidfile_close(pidfh); 524 525 return (0); 526 } 527 528