1 /* $NetBSD: dgram_server.c,v 1.2 2020/03/18 19:05:16 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* dgram_server 3 6 /* SUMMARY 7 /* skeleton datagram server subsystem 8 /* SYNOPSIS 9 /* #include <mail_server.h> 10 /* 11 /* NORETURN dgram_server_main(argc, argv, service, key, value, ...) 12 /* int argc; 13 /* char **argv; 14 /* void (*service)(char *buf, int len, char *service_name, char **argv); 15 /* int key; 16 /* DESCRIPTION 17 /* This module implements a skeleton for mail subsystem programs 18 /* that wake up on client request and perform some activity 19 /* without further client interaction. This module supports 20 /* local IPC via a UNIX-domain datagram socket. The resulting 21 /* program expects to be run from the \fBmaster\fR process. 22 /* 23 /* dgram_server_main() is the skeleton entry point. It should 24 /* be called from the application main program. The skeleton 25 /* does the generic command-line options processing, initialization 26 /* of configurable parameters, and receiving datagrams. The 27 /* skeleton never returns. 28 /* 29 /* Arguments: 30 /* .IP "void (*service)(char *buf, int len, char *service_name, char **argv)" 31 /* A pointer to a function that is called by the skeleton each 32 /* time a client sends a datagram to the program's service 33 /* port. The function is run after the program has irrevocably 34 /* dropped its privileges. The buffer argument specifies the 35 /* data read from the datagram port; this data corresponds to 36 /* request. The len argument specifies how much client data 37 /* is available. The maximal size of the buffer is specified 38 /* via the DGRAM_BUF_SIZE manifest constant. The service name 39 /* argument corresponds to the service name in the master.cf 40 /* file. The argv argument specifies command-line arguments 41 /* left over after options processing. 42 /* .PP 43 /* Optional arguments are specified as a null-terminated list 44 /* with macros that have zero or more arguments: 45 /* .IP "CA_MAIL_SERVER_INT_TABLE(CONFIG_INT_TABLE *)" 46 /* A table with configurable parameters, to be loaded from the 47 /* global Postfix configuration file. Tables are loaded in the 48 /* order as specified, and multiple instances of the same type 49 /* are allowed. 50 /* .IP "CA_MAIL_SERVER_LONG_TABLE(CONFIG_LONG_TABLE *)" 51 /* A table with configurable parameters, to be loaded from the 52 /* global Postfix configuration file. Tables are loaded in the 53 /* order as specified, and multiple instances of the same type 54 /* are allowed. 55 /* .IP "CA_MAIL_SERVER_STR_TABLE(CONFIG_STR_TABLE *)" 56 /* A table with configurable parameters, to be loaded from the 57 /* global Postfix configuration file. Tables are loaded in the 58 /* order as specified, and multiple instances of the same type 59 /* are allowed. 60 /* .IP "CA_MAIL_SERVER_BOOL_TABLE(CONFIG_BOOL_TABLE *)" 61 /* A table with configurable parameters, to be loaded from the 62 /* global Postfix configuration file. Tables are loaded in the 63 /* order as specified, and multiple instances of the same type 64 /* are allowed. 65 /* .IP "CA_MAIL_SERVER_TIME_TABLE(CONFIG_TIME_TABLE *)" 66 /* A table with configurable parameters, to be loaded from the 67 /* global Postfix configuration file. Tables are loaded in the 68 /* order as specified, and multiple instances of the same type 69 /* are allowed. 70 /* .IP "CA_MAIL_SERVER_RAW_TABLE(CONFIG_RAW_TABLE *)" 71 /* A table with configurable parameters, to be loaded from the 72 /* global Postfix configuration file. Tables are loaded in the 73 /* order as specified, and multiple instances of the same type 74 /* are allowed. Raw parameters are not subjected to $name 75 /* evaluation. 76 /* .IP "CA_MAIL_SERVER_NINT_TABLE(CONFIG_NINT_TABLE *)" 77 /* A table with configurable parameters, to be loaded from the 78 /* global Postfix configuration file. Tables are loaded in the 79 /* order as specified, and multiple instances of the same type 80 /* are allowed. 81 /* .IP "CA_MAIL_SERVER_NBOOL_TABLE(CONFIG_NBOOL_TABLE *)" 82 /* A table with configurable parameters, to be loaded from the 83 /* global Postfix configuration file. Tables are loaded in the 84 /* order as specified, and multiple instances of the same type 85 /* are allowed. 86 /* .IP "CA_MAIL_SERVER_PRE_INIT(void *(char *service_name, char **argv))" 87 /* A pointer to a function that is called once 88 /* by the skeleton after it has read the global configuration file 89 /* and after it has processed command-line arguments, but before 90 /* the skeleton has optionally relinquished the process privileges. 91 /* .sp 92 /* Only the last instance of this parameter type is remembered. 93 /* .IP "CA_MAIL_SERVER_POST_INIT(void *(char *service_name, char **argv))" 94 /* A pointer to a function that is called once 95 /* by the skeleton after it has optionally relinquished the process 96 /* privileges, but before servicing client connection requests. 97 /* .sp 98 /* Only the last instance of this parameter type is remembered. 99 /* .IP "CA_MAIL_SERVER_LOOP(int *(char *service_name, char **argv))" 100 /* A pointer to function that is executed from 101 /* within the event loop, whenever an I/O or timer event has happened, 102 /* or whenever nothing has happened for a specified amount of time. 103 /* The result value of the function specifies how long to wait until 104 /* the next event. Specify -1 to wait for "as long as it takes". 105 /* .sp 106 /* Only the last instance of this parameter type is remembered. 107 /* .IP "CA_MAIL_SERVER_EXIT(void *(char *service_name, char **argv))" 108 /* A pointer to function that is executed immediately before normal 109 /* process termination. 110 /* .sp 111 /* Only the last instance of this parameter type is remembered. 112 /* .IP "CA_MAIL_SERVER_PRE_ACCEPT(void *(char *service_name, char **argv))" 113 /* Function to be executed prior to accepting a new request. 114 /* .sp 115 /* Only the last instance of this parameter type is remembered. 116 /* .IP "CA_MAIL_SERVER_IN_FLOW_DELAY(none)" 117 /* Pause $in_flow_delay seconds when no "mail flow control token" 118 /* is available. A token is consumed for each connection request. 119 /* .IP CA_MAIL_SERVER_SOLITARY 120 /* This service must be configured with process limit of 1. 121 /* .IP CA_MAIL_SERVER_UNLIMITED 122 /* This service must be configured with process limit of 0. 123 /* .IP CA_MAIL_SERVER_PRIVILEGED 124 /* This service must be configured as privileged. 125 /* .IP "CA_MAIL_SERVER_WATCHDOG(int *)" 126 /* Override the default 1000s watchdog timeout. The value is 127 /* used after command-line and main.cf file processing. 128 /* .IP "CA_MAIL_SERVER_BOUNCE_INIT(const char *, const char **)" 129 /* Initialize the DSN filter for the bounce/defer service 130 /* clients with the specified map source and map names. 131 /* .PP 132 /* The var_use_limit variable limits the number of clients that 133 /* a server can service before it commits suicide. 134 /* This value is taken from the global \fBmain.cf\fR configuration 135 /* file. Setting \fBvar_use_limit\fR to zero disables the client limit. 136 /* 137 /* The var_idle_limit variable limits the time that a service 138 /* receives no client connection requests before it commits suicide. 139 /* This value is taken from the global \fBmain.cf\fR configuration 140 /* file. Setting \fBvar_use_limit\fR to zero disables the idle limit. 141 /* DIAGNOSTICS 142 /* Problems and transactions are logged to \fBsyslogd\fR(8) 143 /* or \fBpostlogd\fR(8). 144 /* SEE ALSO 145 /* master(8), master process 146 /* postlogd(8), Postfix logging 147 /* syslogd(8), system logging 148 /* LICENSE 149 /* .ad 150 /* .fi 151 /* The Secure Mailer license must be distributed with this software. 152 /* AUTHOR(S) 153 /* Wietse Venema 154 /* Google, Inc. 155 /* 111 8th Avenue 156 /* New York, NY 10011, USA 157 /*--*/ 158 159 /* System library. */ 160 161 #include <sys_defs.h> 162 #include <sys/socket.h> 163 #include <unistd.h> 164 #include <signal.h> 165 #include <stdlib.h> 166 #include <limits.h> 167 #include <string.h> 168 #include <errno.h> 169 #include <fcntl.h> 170 #include <stdarg.h> 171 #ifdef STRCASECMP_IN_STRINGS_H 172 #include <strings.h> 173 #endif 174 #include <time.h> 175 176 /* Utility library. */ 177 178 #include <msg.h> 179 #include <msg_vstream.h> 180 #include <chroot_uid.h> 181 #include <vstring.h> 182 #include <vstream.h> 183 #include <msg_vstream.h> 184 #include <mymalloc.h> 185 #include <events.h> 186 #include <iostuff.h> 187 #include <stringops.h> 188 #include <sane_accept.h> 189 #include <myflock.h> 190 #include <safe_open.h> 191 #include <listen.h> 192 #include <watchdog.h> 193 #include <split_at.h> 194 195 /* Global library. */ 196 197 #include <mail_params.h> 198 #include <mail_task.h> 199 #include <debug_process.h> 200 #include <mail_conf.h> 201 #include <mail_dict.h> 202 #include <resolve_local.h> 203 #include <mail_flow.h> 204 #include <mail_version.h> 205 #include <bounce.h> 206 #include <maillog_client.h> 207 208 /* Process manager. */ 209 210 #include "master_proto.h" 211 212 /* Application-specific */ 213 214 #include "mail_server.h" 215 216 /* 217 * Global state. 218 */ 219 static int use_count; 220 221 static DGRAM_SERVER_FN dgram_server_service; 222 static char *dgram_server_name; 223 static char **dgram_server_argv; 224 static void (*dgram_server_accept) (int, void *); 225 static void (*dgram_server_onexit) (char *, char **); 226 static void (*dgram_server_pre_accept) (char *, char **); 227 static VSTREAM *dgram_server_lock; 228 static int dgram_server_in_flow_delay; 229 static unsigned dgram_server_generation; 230 static int dgram_server_watchdog = 1000; 231 232 /* dgram_server_exit - normal termination */ 233 234 static NORETURN dgram_server_exit(void) 235 { 236 if (dgram_server_onexit) 237 dgram_server_onexit(dgram_server_name, dgram_server_argv); 238 exit(0); 239 } 240 241 /* dgram_server_abort - terminate after abnormal master exit */ 242 243 static void dgram_server_abort(int unused_event, void *unused_context) 244 { 245 if (msg_verbose) 246 msg_info("master disconnect -- exiting"); 247 dgram_server_exit(); 248 } 249 250 /* dgram_server_timeout - idle time exceeded */ 251 252 static void dgram_server_timeout(int unused_event, void *unused_context) 253 { 254 if (msg_verbose) 255 msg_info("idle timeout -- exiting"); 256 dgram_server_exit(); 257 } 258 259 /* dgram_server_wakeup - wake up application */ 260 261 static void dgram_server_wakeup(int fd) 262 { 263 char buf[DGRAM_BUF_SIZE]; 264 ssize_t len; 265 266 /* 267 * Commit suicide when the master process disconnected from us, after 268 * handling the client request. 269 */ 270 if (master_notify(var_pid, dgram_server_generation, MASTER_STAT_TAKEN) < 0) 271 /* void */ ; 272 if (dgram_server_in_flow_delay && mail_flow_get(1) < 0) 273 doze(var_in_flow_delay * 1000000); 274 if ((len = recv(fd, buf, sizeof(buf), 0)) >= 0) 275 dgram_server_service(buf, len, dgram_server_name, dgram_server_argv); 276 if (master_notify(var_pid, dgram_server_generation, MASTER_STAT_AVAIL) < 0) 277 dgram_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT); 278 if (var_idle_limit > 0) 279 event_request_timer(dgram_server_timeout, (void *) 0, var_idle_limit); 280 /* Avoid integer wrap-around in a persistent process. */ 281 if (use_count < INT_MAX) 282 use_count++; 283 } 284 285 /* dgram_server_accept_unix - handle UNIX-domain socket event */ 286 287 static void dgram_server_accept_unix(int unused_event, void *context) 288 { 289 const char *myname = "dgram_server_accept"; 290 int listen_fd = CAST_ANY_PTR_TO_INT(context); 291 292 if (dgram_server_lock != 0 293 && myflock(vstream_fileno(dgram_server_lock), INTERNAL_LOCK, 294 MYFLOCK_OP_NONE) < 0) 295 msg_fatal("select unlock: %m"); 296 297 if (msg_verbose) 298 msg_info("%s: request arrived", myname); 299 300 /* 301 * Read whatever the other side wrote. The socket is non-blocking so we 302 * won't get stuck when multiple processes wake up. 303 */ 304 if (dgram_server_pre_accept) 305 dgram_server_pre_accept(dgram_server_name, dgram_server_argv); 306 dgram_server_wakeup(listen_fd); 307 } 308 309 /* dgram_server_main - the real main program */ 310 311 NORETURN dgram_server_main(int argc, char **argv, DGRAM_SERVER_FN service,...) 312 { 313 const char *myname = "dgram_server_main"; 314 char *root_dir = 0; 315 char *user_name = 0; 316 int debug_me = 0; 317 int daemon_mode = 1; 318 char *service_name = basename(argv[0]); 319 int delay; 320 int c; 321 int socket_count = 1; 322 int fd; 323 va_list ap; 324 MAIL_SERVER_INIT_FN pre_init = 0; 325 MAIL_SERVER_INIT_FN post_init = 0; 326 MAIL_SERVER_LOOP_FN loop = 0; 327 int key; 328 char *transport = 0; 329 char *lock_path; 330 VSTRING *why; 331 int alone = 0; 332 int zerolimit = 0; 333 WATCHDOG *watchdog; 334 char *oname_val; 335 char *oname; 336 char *oval; 337 const char *err; 338 char *generation; 339 int msg_vstream_needed = 0; 340 const char *dsn_filter_title; 341 const char **dsn_filter_maps; 342 343 /* 344 * Process environment options as early as we can. 345 */ 346 if (getenv(CONF_ENV_VERB)) 347 msg_verbose = 1; 348 if (getenv(CONF_ENV_DEBUG)) 349 debug_me = 1; 350 351 /* 352 * Don't die when a process goes away unexpectedly. 353 */ 354 signal(SIGPIPE, SIG_IGN); 355 356 /* 357 * Don't die for frivolous reasons. 358 */ 359 #ifdef SIGXFSZ 360 signal(SIGXFSZ, SIG_IGN); 361 #endif 362 363 /* 364 * May need this every now and then. 365 */ 366 var_procname = mystrdup(basename(argv[0])); 367 set_mail_conf_str(VAR_PROCNAME, var_procname); 368 369 /* 370 * Initialize logging and exit handler. Do the syslog first, so that its 371 * initialization completes before we enter the optional chroot jail. 372 */ 373 maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE); 374 if (msg_verbose) 375 msg_info("daemon started"); 376 377 /* 378 * Check the Postfix library version as soon as we enable logging. 379 */ 380 MAIL_VERSION_CHECK; 381 382 /* 383 * Initialize from the configuration file. Allow command-line options to 384 * override compiled-in defaults or configured parameter values. 385 */ 386 mail_conf_suck(); 387 388 /* 389 * After database open error, continue execution with reduced 390 * functionality. 391 */ 392 dict_allow_surrogate = 1; 393 394 /* 395 * Pick up policy settings from master process. Shut up error messages to 396 * stderr, because no-one is going to see them. 397 */ 398 opterr = 0; 399 while ((c = GETOPT(argc, argv, "cdDi:lm:n:o:s:t:uvVz")) > 0) { 400 switch (c) { 401 case 'c': 402 root_dir = "setme"; 403 break; 404 case 'd': 405 daemon_mode = 0; 406 break; 407 case 'D': 408 debug_me = 1; 409 break; 410 case 'i': 411 mail_conf_update(VAR_MAX_IDLE, optarg); 412 break; 413 case 'l': 414 alone = 1; 415 break; 416 case 'm': 417 mail_conf_update(VAR_MAX_USE, optarg); 418 break; 419 case 'n': 420 service_name = optarg; 421 break; 422 case 'o': 423 oname_val = mystrdup(optarg); 424 if ((err = split_nameval(oname_val, &oname, &oval)) != 0) 425 msg_fatal("invalid \"-o %s\" option value: %s", optarg, err); 426 mail_conf_update(oname, oval); 427 myfree(oname_val); 428 break; 429 case 's': 430 if ((socket_count = atoi(optarg)) <= 0) 431 msg_fatal("invalid socket_count: %s", optarg); 432 break; 433 case 't': 434 transport = optarg; 435 break; 436 case 'u': 437 user_name = "setme"; 438 break; 439 case 'v': 440 msg_verbose++; 441 break; 442 case 'V': 443 if (++msg_vstream_needed == 1) 444 msg_vstream_init(mail_task(var_procname), VSTREAM_ERR); 445 break; 446 case 'z': 447 zerolimit = 1; 448 break; 449 default: 450 msg_fatal("invalid option: %c", optopt); 451 break; 452 } 453 } 454 set_mail_conf_str(VAR_SERVNAME, service_name); 455 456 /* 457 * Initialize generic parameters and re-initialize logging in case of a 458 * non-default program name or logging destination. 459 */ 460 mail_params_init(); 461 maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE); 462 463 /* 464 * Register higher-level dictionaries and initialize the support for 465 * dynamically-loaded dictionarles. 466 */ 467 mail_dict_init(); 468 469 /* 470 * If not connected to stdin, stdin must not be a terminal. 471 */ 472 if (daemon_mode && isatty(STDIN_FILENO)) { 473 msg_vstream_init(var_procname, VSTREAM_ERR); 474 msg_fatal("do not run this command by hand"); 475 } 476 477 /* 478 * Application-specific initialization. 479 */ 480 va_start(ap, service); 481 while ((key = va_arg(ap, int)) != 0) { 482 switch (key) { 483 case MAIL_SERVER_INT_TABLE: 484 get_mail_conf_int_table(va_arg(ap, CONFIG_INT_TABLE *)); 485 break; 486 case MAIL_SERVER_LONG_TABLE: 487 get_mail_conf_long_table(va_arg(ap, CONFIG_LONG_TABLE *)); 488 break; 489 case MAIL_SERVER_STR_TABLE: 490 get_mail_conf_str_table(va_arg(ap, CONFIG_STR_TABLE *)); 491 break; 492 case MAIL_SERVER_BOOL_TABLE: 493 get_mail_conf_bool_table(va_arg(ap, CONFIG_BOOL_TABLE *)); 494 break; 495 case MAIL_SERVER_TIME_TABLE: 496 get_mail_conf_time_table(va_arg(ap, CONFIG_TIME_TABLE *)); 497 break; 498 case MAIL_SERVER_RAW_TABLE: 499 get_mail_conf_raw_table(va_arg(ap, CONFIG_RAW_TABLE *)); 500 break; 501 case MAIL_SERVER_NINT_TABLE: 502 get_mail_conf_nint_table(va_arg(ap, CONFIG_NINT_TABLE *)); 503 break; 504 case MAIL_SERVER_NBOOL_TABLE: 505 get_mail_conf_nbool_table(va_arg(ap, CONFIG_NBOOL_TABLE *)); 506 break; 507 case MAIL_SERVER_PRE_INIT: 508 pre_init = va_arg(ap, MAIL_SERVER_INIT_FN); 509 break; 510 case MAIL_SERVER_POST_INIT: 511 post_init = va_arg(ap, MAIL_SERVER_INIT_FN); 512 break; 513 case MAIL_SERVER_LOOP: 514 loop = va_arg(ap, MAIL_SERVER_LOOP_FN); 515 break; 516 case MAIL_SERVER_EXIT: 517 dgram_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN); 518 break; 519 case MAIL_SERVER_PRE_ACCEPT: 520 dgram_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN); 521 break; 522 case MAIL_SERVER_IN_FLOW_DELAY: 523 dgram_server_in_flow_delay = 1; 524 break; 525 case MAIL_SERVER_SOLITARY: 526 if (!alone) 527 msg_fatal("service %s requires a process limit of 1", 528 service_name); 529 break; 530 case MAIL_SERVER_UNLIMITED: 531 if (!zerolimit) 532 msg_fatal("service %s requires a process limit of 0", 533 service_name); 534 break; 535 case MAIL_SERVER_PRIVILEGED: 536 if (user_name) 537 msg_fatal("service %s requires privileged operation", 538 service_name); 539 break; 540 case MAIL_SERVER_WATCHDOG: 541 dgram_server_watchdog = *va_arg(ap, int *); 542 break; 543 case MAIL_SERVER_BOUNCE_INIT: 544 dsn_filter_title = va_arg(ap, const char *); 545 dsn_filter_maps = va_arg(ap, const char **); 546 bounce_client_init(dsn_filter_title, *dsn_filter_maps); 547 break; 548 default: 549 msg_panic("%s: unknown argument type: %d", myname, key); 550 } 551 } 552 va_end(ap); 553 554 if (root_dir) 555 root_dir = var_queue_dir; 556 if (user_name) 557 user_name = var_mail_owner; 558 559 /* 560 * Can options be required? 561 */ 562 if (transport == 0) 563 msg_fatal("no transport type specified"); 564 else if (strcasecmp(transport, MASTER_XPORT_NAME_UXDG) == 0) 565 dgram_server_accept = dgram_server_accept_unix; 566 else 567 msg_fatal("unsupported transport type: %s", transport); 568 569 /* 570 * Retrieve process generation from environment. 571 */ 572 if ((generation = getenv(MASTER_GEN_NAME)) != 0) { 573 if (!alldig(generation)) 574 msg_fatal("bad generation: %s", generation); 575 OCTAL_TO_UNSIGNED(dgram_server_generation, generation); 576 if (msg_verbose) 577 msg_info("process generation: %s (%o)", 578 generation, dgram_server_generation); 579 } 580 581 /* 582 * Optionally start the debugger on ourself. 583 */ 584 if (debug_me) 585 debug_process(); 586 587 /* 588 * Traditionally, BSD select() can't handle multiple processes selecting 589 * on the same socket, and wakes up every process in select(). See TCP/IP 590 * Illustrated volume 2 page 532. We avoid select() collisions with an 591 * external lock file. 592 */ 593 if (!alone) { 594 lock_path = concatenate(DEF_PID_DIR, "/", transport, 595 ".", service_name, (char *) 0); 596 why = vstring_alloc(1); 597 if ((dgram_server_lock = safe_open(lock_path, O_CREAT | O_RDWR, 0600, 598 (struct stat *) 0, -1, -1, why)) == 0) 599 msg_fatal("open lock file %s: %s", lock_path, vstring_str(why)); 600 close_on_exec(vstream_fileno(dgram_server_lock), CLOSE_ON_EXEC); 601 myfree(lock_path); 602 vstring_free(why); 603 } 604 605 /* 606 * Set up call-back info. 607 */ 608 dgram_server_service = service; 609 dgram_server_name = service_name; 610 dgram_server_argv = argv + optind; 611 612 /* 613 * Run pre-jail initialization. 614 */ 615 if (chdir(var_queue_dir) < 0) 616 msg_fatal("chdir(\"%s\"): %m", var_queue_dir); 617 if (pre_init) 618 pre_init(dgram_server_name, dgram_server_argv); 619 620 /* 621 * Optionally, restrict the damage that this process can do. 622 */ 623 resolve_local_init(); 624 tzset(); 625 chroot_uid(root_dir, user_name); 626 627 /* 628 * Run post-jail initialization. 629 */ 630 if (post_init) 631 post_init(dgram_server_name, dgram_server_argv); 632 633 /* 634 * Running as a semi-resident server. Service requests. Terminate when we 635 * have serviced a sufficient number of requests, when no-one has been 636 * talking to us for a configurable amount of time, or when the master 637 * process terminated abnormally. 638 */ 639 if (var_idle_limit > 0) 640 event_request_timer(dgram_server_timeout, (void *) 0, var_idle_limit); 641 for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) { 642 event_enable_read(fd, dgram_server_accept, CAST_INT_TO_VOID_PTR(fd)); 643 close_on_exec(fd, CLOSE_ON_EXEC); 644 } 645 event_enable_read(MASTER_STATUS_FD, dgram_server_abort, (void *) 0); 646 close_on_exec(MASTER_STATUS_FD, CLOSE_ON_EXEC); 647 close_on_exec(MASTER_FLOW_READ, CLOSE_ON_EXEC); 648 close_on_exec(MASTER_FLOW_WRITE, CLOSE_ON_EXEC); 649 watchdog = watchdog_create(dgram_server_watchdog, 650 (WATCHDOG_FN) 0, (void *) 0); 651 652 /* 653 * The event loop, at last. 654 */ 655 while (var_use_limit == 0 || use_count < var_use_limit) { 656 if (dgram_server_lock != 0) { 657 watchdog_stop(watchdog); 658 if (myflock(vstream_fileno(dgram_server_lock), INTERNAL_LOCK, 659 MYFLOCK_OP_EXCLUSIVE) < 0) 660 msg_fatal("select lock: %m"); 661 } 662 watchdog_start(watchdog); 663 delay = loop ? loop(dgram_server_name, dgram_server_argv) : -1; 664 event_loop(delay); 665 } 666 dgram_server_exit(); 667 } 668