1 /* $NetBSD: trigger_server.c,v 1.1.1.1 2009/06/23 10:08:49 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* trigger_server 3 6 /* SUMMARY 7 /* skeleton triggered mail subsystem 8 /* SYNOPSIS 9 /* #include <mail_server.h> 10 /* 11 /* NORETURN trigger_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 triggered 18 /* mail subsystems: mail subsystem programs that wake up on 19 /* client request and perform some activity without further 20 /* client interaction. This module supports local IPC via FIFOs 21 /* and via UNIX-domain sockets. The resulting program expects to be 22 /* run from the \fBmaster\fR process. 23 /* 24 /* trigger_server_main() is the skeleton entry point. It should be 25 /* called from the application main program. The skeleton does the 26 /* generic command-line options processing, initialization of 27 /* configurable parameters, and connection management. 28 /* The skeleton never returns. 29 /* 30 /* Arguments: 31 /* .IP "void (*service)(char *buf, int len, char *service_name, char **argv)" 32 /* A pointer to a function that is called by the skeleton each time 33 /* a client connects to the program's service port. The function is 34 /* run after the program has irrevocably dropped its privileges. 35 /* The buffer argument specifies the data read from the trigger port; 36 /* this data corresponds to one or more trigger requests. 37 /* The len argument specifies how much client data is available. 38 /* The maximal size of the buffer is specified via the 39 /* TRIGGER_BUF_SIZE manifest constant. 40 /* The service name argument corresponds to the service name in the 41 /* master.cf file. 42 /* The argv argument specifies command-line arguments left over 43 /* after options processing. 44 /* The \fBserver\fR argument provides the following information: 45 /* .PP 46 /* Optional arguments are specified as a null-terminated (key, value) 47 /* list. Keys and expected values are: 48 /* .IP "MAIL_SERVER_INT_TABLE (CONFIG_INT_TABLE *)" 49 /* A table with configurable parameters, to be loaded from the 50 /* global Postfix configuration file. Tables are loaded in the 51 /* order as specified, and multiple instances of the same type 52 /* are allowed. 53 /* .IP "MAIL_SERVER_STR_TABLE (CONFIG_STR_TABLE *)" 54 /* A table with configurable parameters, to be loaded from the 55 /* global Postfix configuration file. Tables are loaded in the 56 /* order as specified, and multiple instances of the same type 57 /* are allowed. 58 /* .IP "MAIL_SERVER_BOOL_TABLE (CONFIG_BOOL_TABLE *)" 59 /* A table with configurable parameters, to be loaded from the 60 /* global Postfix configuration file. Tables are loaded in the 61 /* order as specified, and multiple instances of the same type 62 /* are allowed. 63 /* .IP "MAIL_SERVER_TIME_TABLE (CONFIG_TIME_TABLE *)" 64 /* A table with configurable parameters, to be loaded from the 65 /* global Postfix configuration file. Tables are loaded in the 66 /* order as specified, and multiple instances of the same type 67 /* are allowed. 68 /* .IP "MAIL_SERVER_RAW_TABLE (CONFIG_RAW_TABLE *)" 69 /* A table with configurable parameters, to be loaded from the 70 /* global Postfix configuration file. Tables are loaded in the 71 /* order as specified, and multiple instances of the same type 72 /* are allowed. Raw parameters are not subjected to $name 73 /* evaluation. 74 /* .IP "MAIL_SERVER_NINT_TABLE (CONFIG_NINT_TABLE *)" 75 /* A table with configurable parameters, to be loaded from the 76 /* global Postfix configuration file. Tables are loaded in the 77 /* order as specified, and multiple instances of the same type 78 /* are allowed. 79 /* .IP "MAIL_SERVER_PRE_INIT (void *(char *service_name, char **argv))" 80 /* A pointer to a function that is called once 81 /* by the skeleton after it has read the global configuration file 82 /* and after it has processed command-line arguments, but before 83 /* the skeleton has optionally relinquished the process privileges. 84 /* .sp 85 /* Only the last instance of this parameter type is remembered. 86 /* .IP "MAIL_SERVER_POST_INIT (void *(char *service_name, char **argv))" 87 /* A pointer to a function that is called once 88 /* by the skeleton after it has optionally relinquished the process 89 /* privileges, but before servicing client connection requests. 90 /* .sp 91 /* Only the last instance of this parameter type is remembered. 92 /* .IP "MAIL_SERVER_LOOP (int *(char *service_name, char **argv))" 93 /* A pointer to function that is executed from 94 /* within the event loop, whenever an I/O or timer event has happened, 95 /* or whenever nothing has happened for a specified amount of time. 96 /* The result value of the function specifies how long to wait until 97 /* the next event. Specify -1 to wait for "as long as it takes". 98 /* .sp 99 /* Only the last instance of this parameter type is remembered. 100 /* .IP "MAIL_SERVER_EXIT (void *(char *service_name, char **argv))" 101 /* A pointer to function that is executed immediately before normal 102 /* process termination. 103 /* .sp 104 /* Only the last instance of this parameter type is remembered. 105 /* .IP "MAIL_SERVER_PRE_ACCEPT (void *(char *service_name, char **argv))" 106 /* Function to be executed prior to accepting a new request. 107 /* .sp 108 /* Only the last instance of this parameter type is remembered. 109 /* .IP "MAIL_SERVER_IN_FLOW_DELAY (none)" 110 /* Pause $in_flow_delay seconds when no "mail flow control token" 111 /* is available. A token is consumed for each connection request. 112 /* .IP MAIL_SERVER_SOLITARY 113 /* This service must be configured with process limit of 1. 114 /* .IP MAIL_SERVER_UNLIMITED 115 /* This service must be configured with process limit of 0. 116 /* .IP MAIL_SERVER_PRIVILEGED 117 /* This service must be configured as privileged. 118 /* .IP "MAIL_SERVER_WATCHDOG (int *)" 119 /* Override the default 1000s watchdog timeout. The value is 120 /* used after command-line and main.cf file processing. 121 /* .PP 122 /* The var_use_limit variable limits the number of clients that 123 /* a server can service before it commits suicide. 124 /* This value is taken from the global \fBmain.cf\fR configuration 125 /* file. Setting \fBvar_use_limit\fR to zero disables the client limit. 126 /* 127 /* The var_idle_limit variable limits the time that a service 128 /* receives no client connection requests before it commits suicide. 129 /* This value is taken from the global \fBmain.cf\fR configuration 130 /* file. Setting \fBvar_use_limit\fR to zero disables the idle limit. 131 /* DIAGNOSTICS 132 /* Problems and transactions are logged to \fBsyslogd\fR(8). 133 /* BUGS 134 /* Works with FIFO-based services only. 135 /* SEE ALSO 136 /* master(8), master process 137 /* syslogd(8) system logging 138 /* LICENSE 139 /* .ad 140 /* .fi 141 /* The Secure Mailer license must be distributed with this software. 142 /* AUTHOR(S) 143 /* Wietse Venema 144 /* IBM T.J. Watson Research 145 /* P.O. Box 704 146 /* Yorktown Heights, NY 10598, USA 147 /*--*/ 148 149 /* System library. */ 150 151 #include <sys_defs.h> 152 #include <sys/socket.h> 153 #include <unistd.h> 154 #include <signal.h> 155 #include <syslog.h> 156 #include <stdlib.h> 157 #include <limits.h> 158 #include <string.h> 159 #include <errno.h> 160 #include <fcntl.h> 161 #include <stdarg.h> 162 #ifdef STRCASECMP_IN_STRINGS_H 163 #include <strings.h> 164 #endif 165 #include <time.h> 166 167 /* Utility library. */ 168 169 #include <msg.h> 170 #include <msg_syslog.h> 171 #include <msg_vstream.h> 172 #include <chroot_uid.h> 173 #include <vstring.h> 174 #include <vstream.h> 175 #include <msg_vstream.h> 176 #include <mymalloc.h> 177 #include <events.h> 178 #include <iostuff.h> 179 #include <stringops.h> 180 #include <sane_accept.h> 181 #include <myflock.h> 182 #include <safe_open.h> 183 #include <listen.h> 184 #include <watchdog.h> 185 #include <split_at.h> 186 187 /* Global library. */ 188 189 #include <mail_params.h> 190 #include <mail_task.h> 191 #include <debug_process.h> 192 #include <mail_conf.h> 193 #include <mail_dict.h> 194 #include <resolve_local.h> 195 #include <mail_flow.h> 196 197 /* Process manager. */ 198 199 #include "master_proto.h" 200 201 /* Application-specific */ 202 203 #include "mail_server.h" 204 205 /* 206 * Global state. 207 */ 208 static int use_count; 209 210 static TRIGGER_SERVER_FN trigger_server_service; 211 static char *trigger_server_name; 212 static char **trigger_server_argv; 213 static void (*trigger_server_accept) (int, char *); 214 static void (*trigger_server_onexit) (char *, char **); 215 static void (*trigger_server_pre_accept) (char *, char **); 216 static VSTREAM *trigger_server_lock; 217 static int trigger_server_in_flow_delay; 218 static unsigned trigger_server_generation; 219 static int trigger_server_watchdog = 1000; 220 221 /* trigger_server_exit - normal termination */ 222 223 static NORETURN trigger_server_exit(void) 224 { 225 if (trigger_server_onexit) 226 trigger_server_onexit(trigger_server_name, trigger_server_argv); 227 exit(0); 228 } 229 230 /* trigger_server_abort - terminate after abnormal master exit */ 231 232 static void trigger_server_abort(int unused_event, char *unused_context) 233 { 234 if (msg_verbose) 235 msg_info("master disconnect -- exiting"); 236 trigger_server_exit(); 237 } 238 239 /* trigger_server_timeout - idle time exceeded */ 240 241 static void trigger_server_timeout(int unused_event, char *unused_context) 242 { 243 if (msg_verbose) 244 msg_info("idle timeout -- exiting"); 245 trigger_server_exit(); 246 } 247 248 /* trigger_server_wakeup - wake up application */ 249 250 static void trigger_server_wakeup(int fd) 251 { 252 char buf[TRIGGER_BUF_SIZE]; 253 int len; 254 255 /* 256 * Commit suicide when the master process disconnected from us. Don't 257 * drop the already accepted client request after "postfix reload"; that 258 * would be rude. 259 */ 260 if (master_notify(var_pid, trigger_server_generation, MASTER_STAT_TAKEN) < 0) 261 /* void */ ; 262 if (trigger_server_in_flow_delay && mail_flow_get(1) < 0) 263 doze(var_in_flow_delay * 1000000); 264 if ((len = read(fd, buf, sizeof(buf))) >= 0) 265 trigger_server_service(buf, len, trigger_server_name, 266 trigger_server_argv); 267 if (master_notify(var_pid, trigger_server_generation, MASTER_STAT_AVAIL) < 0) 268 trigger_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT); 269 if (var_idle_limit > 0) 270 event_request_timer(trigger_server_timeout, (char *) 0, var_idle_limit); 271 use_count++; 272 } 273 274 /* trigger_server_accept_fifo - accept fifo client request */ 275 276 static void trigger_server_accept_fifo(int unused_event, char *context) 277 { 278 const char *myname = "trigger_server_accept_fifo"; 279 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 280 281 if (trigger_server_lock != 0 282 && myflock(vstream_fileno(trigger_server_lock), INTERNAL_LOCK, 283 MYFLOCK_OP_NONE) < 0) 284 msg_fatal("select unlock: %m"); 285 286 if (msg_verbose) 287 msg_info("%s: trigger arrived", myname); 288 289 /* 290 * Read whatever the other side wrote into the FIFO. The FIFO read end is 291 * non-blocking so we won't get stuck when multiple processes wake up. 292 */ 293 if (trigger_server_pre_accept) 294 trigger_server_pre_accept(trigger_server_name, trigger_server_argv); 295 trigger_server_wakeup(listen_fd); 296 } 297 298 /* trigger_server_accept_local - accept socket client request */ 299 300 static void trigger_server_accept_local(int unused_event, char *context) 301 { 302 const char *myname = "trigger_server_accept_local"; 303 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 304 int time_left = 0; 305 int fd; 306 307 if (msg_verbose) 308 msg_info("%s: trigger arrived", myname); 309 310 /* 311 * Read a message from a socket. Be prepared for accept() to fail because 312 * some other process already got the connection. The socket is 313 * non-blocking so we won't get stuck when multiple processes wake up. 314 * Don't get stuck when the client connects but sends no data. Restart 315 * the idle timer if this was a false alarm. 316 */ 317 if (var_idle_limit > 0) 318 time_left = event_cancel_timer(trigger_server_timeout, (char *) 0); 319 320 if (trigger_server_pre_accept) 321 trigger_server_pre_accept(trigger_server_name, trigger_server_argv); 322 fd = LOCAL_ACCEPT(listen_fd); 323 if (trigger_server_lock != 0 324 && myflock(vstream_fileno(trigger_server_lock), INTERNAL_LOCK, 325 MYFLOCK_OP_NONE) < 0) 326 msg_fatal("select unlock: %m"); 327 if (fd < 0) { 328 if (errno != EAGAIN) 329 msg_error("accept connection: %m"); 330 if (time_left >= 0) 331 event_request_timer(trigger_server_timeout, (char *) 0, time_left); 332 return; 333 } 334 close_on_exec(fd, CLOSE_ON_EXEC); 335 if (read_wait(fd, 10) == 0) 336 trigger_server_wakeup(fd); 337 else if (time_left >= 0) 338 event_request_timer(trigger_server_timeout, (char *) 0, time_left); 339 close(fd); 340 } 341 342 #ifdef MASTER_XPORT_NAME_PASS 343 344 /* trigger_server_accept_pass - accept descriptor */ 345 346 static void trigger_server_accept_pass(int unused_event, char *context) 347 { 348 const char *myname = "trigger_server_accept_pass"; 349 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 350 int time_left = 0; 351 int fd; 352 353 if (msg_verbose) 354 msg_info("%s: trigger arrived", myname); 355 356 /* 357 * Read a message from a socket. Be prepared for accept() to fail because 358 * some other process already got the connection. The socket is 359 * non-blocking so we won't get stuck when multiple processes wake up. 360 * Don't get stuck when the client connects but sends no data. Restart 361 * the idle timer if this was a false alarm. 362 */ 363 if (var_idle_limit > 0) 364 time_left = event_cancel_timer(trigger_server_timeout, (char *) 0); 365 366 if (trigger_server_pre_accept) 367 trigger_server_pre_accept(trigger_server_name, trigger_server_argv); 368 fd = PASS_ACCEPT(listen_fd); 369 if (trigger_server_lock != 0 370 && myflock(vstream_fileno(trigger_server_lock), INTERNAL_LOCK, 371 MYFLOCK_OP_NONE) < 0) 372 msg_fatal("select unlock: %m"); 373 if (fd < 0) { 374 if (errno != EAGAIN) 375 msg_error("accept connection: %m"); 376 if (time_left >= 0) 377 event_request_timer(trigger_server_timeout, (char *) 0, time_left); 378 return; 379 } 380 close_on_exec(fd, CLOSE_ON_EXEC); 381 if (read_wait(fd, 10) == 0) 382 trigger_server_wakeup(fd); 383 else if (time_left >= 0) 384 event_request_timer(trigger_server_timeout, (char *) 0, time_left); 385 close(fd); 386 } 387 388 #endif 389 390 /* trigger_server_main - the real main program */ 391 392 NORETURN trigger_server_main(int argc, char **argv, TRIGGER_SERVER_FN service,...) 393 { 394 const char *myname = "trigger_server_main"; 395 char *root_dir = 0; 396 char *user_name = 0; 397 int debug_me = 0; 398 int daemon_mode = 1; 399 char *service_name = basename(argv[0]); 400 VSTREAM *stream = 0; 401 int delay; 402 int c; 403 int socket_count = 1; 404 int fd; 405 va_list ap; 406 MAIL_SERVER_INIT_FN pre_init = 0; 407 MAIL_SERVER_INIT_FN post_init = 0; 408 MAIL_SERVER_LOOP_FN loop = 0; 409 int key; 410 char buf[TRIGGER_BUF_SIZE]; 411 int len; 412 char *transport = 0; 413 char *lock_path; 414 VSTRING *why; 415 int alone = 0; 416 int zerolimit = 0; 417 WATCHDOG *watchdog; 418 char *oname; 419 char *oval; 420 char *generation; 421 int msg_vstream_needed = 0; 422 int redo_syslog_init = 0; 423 424 /* 425 * Process environment options as early as we can. 426 */ 427 if (getenv(CONF_ENV_VERB)) 428 msg_verbose = 1; 429 if (getenv(CONF_ENV_DEBUG)) 430 debug_me = 1; 431 432 /* 433 * Don't die when a process goes away unexpectedly. 434 */ 435 signal(SIGPIPE, SIG_IGN); 436 437 /* 438 * Don't die for frivolous reasons. 439 */ 440 #ifdef SIGXFSZ 441 signal(SIGXFSZ, SIG_IGN); 442 #endif 443 444 /* 445 * May need this every now and then. 446 */ 447 var_procname = mystrdup(basename(argv[0])); 448 set_mail_conf_str(VAR_PROCNAME, var_procname); 449 450 /* 451 * Initialize logging and exit handler. Do the syslog first, so that its 452 * initialization completes before we enter the optional chroot jail. 453 */ 454 msg_syslog_init(mail_task(var_procname), LOG_PID, LOG_FACILITY); 455 if (msg_verbose) 456 msg_info("daemon started"); 457 458 /* 459 * Initialize from the configuration file. Allow command-line options to 460 * override compiled-in defaults or configured parameter values. 461 */ 462 mail_conf_suck(); 463 464 /* 465 * Register dictionaries that use higher-level interfaces and protocols. 466 */ 467 mail_dict_init(); 468 469 /* 470 * Pick up policy settings from master process. Shut up error messages to 471 * stderr, because no-one is going to see them. 472 */ 473 opterr = 0; 474 while ((c = GETOPT(argc, argv, "cdDi:lm:n:o:s:St:uvVz")) > 0) { 475 switch (c) { 476 case 'c': 477 root_dir = "setme"; 478 break; 479 case 'd': 480 daemon_mode = 0; 481 break; 482 case 'D': 483 debug_me = 1; 484 break; 485 case 'i': 486 mail_conf_update(VAR_MAX_IDLE, optarg); 487 break; 488 case 'l': 489 alone = 1; 490 break; 491 case 'm': 492 mail_conf_update(VAR_MAX_USE, optarg); 493 break; 494 case 'n': 495 service_name = optarg; 496 break; 497 case 'o': 498 /* XXX Use split_nameval() */ 499 oname = mystrdup(optarg); 500 if ((oval = split_at(oname, '=')) == 0) 501 oval = ""; 502 mail_conf_update(oname, oval); 503 if (strcmp(oname, VAR_SYSLOG_NAME) == 0) 504 redo_syslog_init = 1; 505 break; 506 case 's': 507 if ((socket_count = atoi(optarg)) <= 0) 508 msg_fatal("invalid socket_count: %s", optarg); 509 break; 510 case 'S': 511 stream = VSTREAM_IN; 512 break; 513 case 't': 514 transport = optarg; 515 break; 516 case 'u': 517 user_name = "setme"; 518 break; 519 case 'v': 520 msg_verbose++; 521 break; 522 case 'V': 523 if (++msg_vstream_needed == 1) 524 msg_vstream_init(mail_task(var_procname), VSTREAM_ERR); 525 break; 526 case 'z': 527 zerolimit = 1; 528 break; 529 default: 530 msg_fatal("invalid option: %c", c); 531 break; 532 } 533 } 534 535 /* 536 * Initialize generic parameters. 537 */ 538 mail_params_init(); 539 if (redo_syslog_init) 540 msg_syslog_init(mail_task(var_procname), LOG_PID, LOG_FACILITY); 541 542 /* 543 * If not connected to stdin, stdin must not be a terminal. 544 */ 545 if (daemon_mode && stream == 0 && isatty(STDIN_FILENO)) { 546 msg_vstream_init(var_procname, VSTREAM_ERR); 547 msg_fatal("do not run this command by hand"); 548 } 549 550 /* 551 * Application-specific initialization. 552 */ 553 va_start(ap, service); 554 while ((key = va_arg(ap, int)) != 0) { 555 switch (key) { 556 case MAIL_SERVER_INT_TABLE: 557 get_mail_conf_int_table(va_arg(ap, CONFIG_INT_TABLE *)); 558 break; 559 case MAIL_SERVER_STR_TABLE: 560 get_mail_conf_str_table(va_arg(ap, CONFIG_STR_TABLE *)); 561 break; 562 case MAIL_SERVER_BOOL_TABLE: 563 get_mail_conf_bool_table(va_arg(ap, CONFIG_BOOL_TABLE *)); 564 break; 565 case MAIL_SERVER_TIME_TABLE: 566 get_mail_conf_time_table(va_arg(ap, CONFIG_TIME_TABLE *)); 567 break; 568 case MAIL_SERVER_RAW_TABLE: 569 get_mail_conf_raw_table(va_arg(ap, CONFIG_RAW_TABLE *)); 570 break; 571 case MAIL_SERVER_NINT_TABLE: 572 get_mail_conf_nint_table(va_arg(ap, CONFIG_NINT_TABLE *)); 573 break; 574 case MAIL_SERVER_PRE_INIT: 575 pre_init = va_arg(ap, MAIL_SERVER_INIT_FN); 576 break; 577 case MAIL_SERVER_POST_INIT: 578 post_init = va_arg(ap, MAIL_SERVER_INIT_FN); 579 break; 580 case MAIL_SERVER_LOOP: 581 loop = va_arg(ap, MAIL_SERVER_LOOP_FN); 582 break; 583 case MAIL_SERVER_EXIT: 584 trigger_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN); 585 break; 586 case MAIL_SERVER_PRE_ACCEPT: 587 trigger_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN); 588 break; 589 case MAIL_SERVER_IN_FLOW_DELAY: 590 trigger_server_in_flow_delay = 1; 591 break; 592 case MAIL_SERVER_SOLITARY: 593 if (stream == 0 && !alone) 594 msg_fatal("service %s requires a process limit of 1", 595 service_name); 596 break; 597 case MAIL_SERVER_UNLIMITED: 598 if (stream == 0 && !zerolimit) 599 msg_fatal("service %s requires a process limit of 0", 600 service_name); 601 break; 602 case MAIL_SERVER_PRIVILEGED: 603 if (user_name) 604 msg_fatal("service %s requires privileged operation", 605 service_name); 606 break; 607 case MAIL_SERVER_WATCHDOG: 608 trigger_server_watchdog = *va_arg(ap, int *); 609 break; 610 default: 611 msg_panic("%s: unknown argument type: %d", myname, key); 612 } 613 } 614 va_end(ap); 615 616 if (root_dir) 617 root_dir = var_queue_dir; 618 if (user_name) 619 user_name = var_mail_owner; 620 621 /* 622 * Can options be required? 623 * 624 * XXX Initially this code was implemented with UNIX-domain sockets, but 625 * Solaris <= 2.5 UNIX-domain sockets misbehave hopelessly when the 626 * client disconnects before the server has accepted the connection. 627 * Symptom: the server accept() fails with EPIPE or EPROTO, but the 628 * socket stays readable, so that the program goes into a wasteful loop. 629 * 630 * The initial fix was to use FIFOs, but those turn out to have their own 631 * problems, witness the workarounds in the fifo_listen() routine. 632 * Therefore we support both FIFOs and UNIX-domain sockets, so that the 633 * user can choose whatever works best. 634 * 635 * Well, I give up. Solaris UNIX-domain sockets still don't work properly, 636 * so it will have to limp along with a streams-specific alternative. 637 */ 638 if (stream == 0) { 639 if (transport == 0) 640 msg_fatal("no transport type specified"); 641 if (strcasecmp(transport, MASTER_XPORT_NAME_UNIX) == 0) 642 trigger_server_accept = trigger_server_accept_local; 643 else if (strcasecmp(transport, MASTER_XPORT_NAME_FIFO) == 0) 644 trigger_server_accept = trigger_server_accept_fifo; 645 #ifdef MASTER_XPORT_NAME_PASS 646 else if (strcasecmp(transport, MASTER_XPORT_NAME_PASS) == 0) 647 trigger_server_accept = trigger_server_accept_pass; 648 #endif 649 else 650 msg_fatal("unsupported transport type: %s", transport); 651 } 652 653 /* 654 * Retrieve process generation from environment. 655 */ 656 if ((generation = getenv(MASTER_GEN_NAME)) != 0) { 657 if (!alldig(generation)) 658 msg_fatal("bad generation: %s", generation); 659 OCTAL_TO_UNSIGNED(trigger_server_generation, generation); 660 if (msg_verbose) 661 msg_info("process generation: %s (%o)", 662 generation, trigger_server_generation); 663 } 664 665 /* 666 * Optionally start the debugger on ourself. 667 */ 668 if (debug_me) 669 debug_process(); 670 671 /* 672 * Traditionally, BSD select() can't handle multiple processes selecting 673 * on the same socket, and wakes up every process in select(). See TCP/IP 674 * Illustrated volume 2 page 532. We avoid select() collisions with an 675 * external lock file. 676 */ 677 if (stream == 0 && !alone) { 678 lock_path = concatenate(DEF_PID_DIR, "/", transport, 679 ".", service_name, (char *) 0); 680 why = vstring_alloc(1); 681 if ((trigger_server_lock = safe_open(lock_path, O_CREAT | O_RDWR, 0600, 682 (struct stat *) 0, -1, -1, why)) == 0) 683 msg_fatal("open lock file %s: %s", lock_path, vstring_str(why)); 684 close_on_exec(vstream_fileno(trigger_server_lock), CLOSE_ON_EXEC); 685 myfree(lock_path); 686 vstring_free(why); 687 } 688 689 /* 690 * Set up call-back info. 691 */ 692 trigger_server_service = service; 693 trigger_server_name = service_name; 694 trigger_server_argv = argv + optind; 695 696 /* 697 * Run pre-jail initialization. 698 */ 699 if (chdir(var_queue_dir) < 0) 700 msg_fatal("chdir(\"%s\"): %m", var_queue_dir); 701 if (pre_init) 702 pre_init(trigger_server_name, trigger_server_argv); 703 704 /* 705 * Optionally, restrict the damage that this process can do. 706 */ 707 resolve_local_init(); 708 tzset(); 709 chroot_uid(root_dir, user_name); 710 711 /* 712 * Run post-jail initialization. 713 */ 714 if (post_init) 715 post_init(trigger_server_name, trigger_server_argv); 716 717 /* 718 * Are we running as a one-shot server with the client connection on 719 * standard input? 720 */ 721 if (stream != 0) { 722 if ((len = read(vstream_fileno(stream), buf, sizeof(buf))) <= 0) 723 msg_fatal("read: %m"); 724 service(buf, len, trigger_server_name, trigger_server_argv); 725 vstream_fflush(stream); 726 trigger_server_exit(); 727 } 728 729 /* 730 * Running as a semi-resident server. Service connection requests. 731 * Terminate when we have serviced a sufficient number of clients, when 732 * no-one has been talking to us for a configurable amount of time, or 733 * when the master process terminated abnormally. 734 */ 735 if (var_idle_limit > 0) 736 event_request_timer(trigger_server_timeout, (char *) 0, var_idle_limit); 737 for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) { 738 event_enable_read(fd, trigger_server_accept, CAST_INT_TO_CHAR_PTR(fd)); 739 close_on_exec(fd, CLOSE_ON_EXEC); 740 } 741 event_enable_read(MASTER_STATUS_FD, trigger_server_abort, (char *) 0); 742 close_on_exec(MASTER_STATUS_FD, CLOSE_ON_EXEC); 743 close_on_exec(MASTER_FLOW_READ, CLOSE_ON_EXEC); 744 close_on_exec(MASTER_FLOW_WRITE, CLOSE_ON_EXEC); 745 watchdog = watchdog_create(trigger_server_watchdog, 746 (WATCHDOG_FN) 0, (char *) 0); 747 748 /* 749 * The event loop, at last. 750 */ 751 while (var_use_limit == 0 || use_count < var_use_limit) { 752 if (trigger_server_lock != 0) { 753 watchdog_stop(watchdog); 754 if (myflock(vstream_fileno(trigger_server_lock), INTERNAL_LOCK, 755 MYFLOCK_OP_EXCLUSIVE) < 0) 756 msg_fatal("select lock: %m"); 757 } 758 watchdog_start(watchdog); 759 delay = loop ? loop(trigger_server_name, trigger_server_argv) : -1; 760 event_loop(delay); 761 } 762 trigger_server_exit(); 763 } 764