1 /* $NetBSD: multi_server.c,v 1.1.1.1 2009/06/23 10:08:49 tron Exp $ */ 2 3 /*++ 4 /* NAME 5 /* multi_server 3 6 /* SUMMARY 7 /* skeleton multi-threaded mail subsystem 8 /* SYNOPSIS 9 /* #include <mail_server.h> 10 /* 11 /* NORETURN multi_server_main(argc, argv, service, key, value, ...) 12 /* int argc; 13 /* char **argv; 14 /* void (*service)(VSTREAM *stream, char *service_name, char **argv); 15 /* int key; 16 /* 17 /* void multi_server_disconnect(stream) 18 /* VSTREAM *stream; 19 /* 20 /* void multi_server_drain() 21 /* DESCRIPTION 22 /* This module implements a skeleton for multi-threaded 23 /* mail subsystems: mail subsystem programs that service multiple 24 /* clients at the same time. The resulting program expects to be run 25 /* from the \fBmaster\fR process. 26 /* 27 /* multi_server_main() is the skeleton entry point. It should be 28 /* called from the application main program. The skeleton does all 29 /* the generic command-line processing, initialization of 30 /* configurable parameters, and connection management. 31 /* The skeleton never returns. 32 /* 33 /* Arguments: 34 /* .IP "void (*service)(VSTREAM *stream, char *service_name, char **argv)" 35 /* A pointer to a function that is called by the skeleton each 36 /* time a client sends data to the program's service port. The 37 /* function is run after the program has optionally dropped its 38 /* privileges. This function should not attempt to preserve state 39 /* across calls. The stream initial state is non-blocking mode. 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 /* .PP 45 /* Optional arguments are specified as a null-terminated (key, value) 46 /* list. Keys and expected values are: 47 /* .IP "MAIL_SERVER_INT_TABLE (CONFIG_INT_TABLE *)" 48 /* A table with configurable parameters, to be loaded from the 49 /* global Postfix configuration file. Tables are loaded in the 50 /* order as specified, and multiple instances of the same type 51 /* are allowed. 52 /* .IP "MAIL_SERVER_STR_TABLE (CONFIG_STR_TABLE *)" 53 /* A table with configurable parameters, to be loaded from the 54 /* global Postfix configuration file. Tables are loaded in the 55 /* order as specified, and multiple instances of the same type 56 /* are allowed. 57 /* .IP "MAIL_SERVER_BOOL_TABLE (CONFIG_BOOL_TABLE *)" 58 /* A table with configurable parameters, to be loaded from the 59 /* global Postfix configuration file. Tables are loaded in the 60 /* order as specified, and multiple instances of the same type 61 /* are allowed. 62 /* .IP "MAIL_SERVER_TIME_TABLE (CONFIG_TIME_TABLE *)" 63 /* A table with configurable parameters, to be loaded from the 64 /* global Postfix configuration file. Tables are loaded in the 65 /* order as specified, and multiple instances of the same type 66 /* are allowed. 67 /* .IP "MAIL_SERVER_RAW_TABLE (CONFIG_RAW_TABLE *)" 68 /* A table with configurable parameters, to be loaded from the 69 /* global Postfix configuration file. Tables are loaded in the 70 /* order as specified, and multiple instances of the same type 71 /* are allowed. Raw parameters are not subjected to $name 72 /* evaluation. 73 /* .IP "MAIL_SERVER_NINT_TABLE (CONFIG_NINT_TABLE *)" 74 /* A table with configurable parameters, to be loaded from the 75 /* global Postfix configuration file. Tables are loaded in the 76 /* order as specified, and multiple instances of the same type 77 /* are allowed. 78 /* .IP "MAIL_SERVER_PRE_INIT (void *(char *service_name, char **argv))" 79 /* A pointer to a function that is called once 80 /* by the skeleton after it has read the global configuration file 81 /* and after it has processed command-line arguments, but before 82 /* the skeleton has optionally relinquished the process privileges. 83 /* .sp 84 /* Only the last instance of this parameter type is remembered. 85 /* .IP "MAIL_SERVER_POST_INIT (void *(char *service_name, char **argv))" 86 /* A pointer to a function that is called once 87 /* by the skeleton after it has optionally relinquished the process 88 /* privileges, but before servicing client connection requests. 89 /* .sp 90 /* Only the last instance of this parameter type is remembered. 91 /* .IP "MAIL_SERVER_LOOP (int *(char *service_name, char **argv))" 92 /* A pointer to function that is executed from 93 /* within the event loop, whenever an I/O or timer event has happened, 94 /* or whenever nothing has happened for a specified amount of time. 95 /* The result value of the function specifies how long to wait until 96 /* the next event. Specify -1 to wait for "as long as it takes". 97 /* .sp 98 /* Only the last instance of this parameter type is remembered. 99 /* .IP "MAIL_SERVER_EXIT (void *(char *service_name, char **argv))" 100 /* A pointer to function that is executed immediately before normal 101 /* process termination. 102 /* .IP "MAIL_SERVER_PRE_ACCEPT (void *(char *service_name, char **argv))" 103 /* Function to be executed prior to accepting a new connection. 104 /* .sp 105 /* Only the last instance of this parameter type is remembered. 106 /* .IP "MAIL_SERVER_PRE_DISCONN (VSTREAM *, char *service_name, char **argv)" 107 /* A pointer to a function that is called 108 /* by the multi_server_disconnect() function (see below). 109 /* .sp 110 /* Only the last instance of this parameter type is remembered. 111 /* .IP "MAIL_SERVER_IN_FLOW_DELAY (none)" 112 /* Pause $in_flow_delay seconds when no "mail flow control token" 113 /* is available. A token is consumed for each connection request. 114 /* .IP MAIL_SERVER_SOLITARY 115 /* This service must be configured with process limit of 1. 116 /* .IP MAIL_SERVER_UNLIMITED 117 /* This service must be configured with process limit of 0. 118 /* .IP MAIL_SERVER_PRIVILEGED 119 /* This service must be configured as privileged. 120 /* .PP 121 /* multi_server_disconnect() should be called by the application 122 /* when a client disconnects. 123 /* 124 /* multi_server_drain() should be called when the application 125 /* no longer wishes to accept new client connections. Existing 126 /* clients are handled in a background process. A non-zero 127 /* result means this call should be tried again later. 128 /* 129 /* The var_use_limit variable limits the number of clients that 130 /* a server can service before it commits suicide. 131 /* This value is taken from the global \fBmain.cf\fR configuration 132 /* file. Setting \fBvar_use_limit\fR to zero disables the client limit. 133 /* 134 /* The var_idle_limit variable limits the time that a service 135 /* receives no client connection requests before it commits suicide. 136 /* This value is taken from the global \fBmain.cf\fR configuration 137 /* file. Setting \fBvar_idle_limit\fR to zero disables the idle limit. 138 /* DIAGNOSTICS 139 /* Problems and transactions are logged to \fBsyslogd\fR(8). 140 /* SEE ALSO 141 /* master(8), master process 142 /* syslogd(8) system logging 143 /* LICENSE 144 /* .ad 145 /* .fi 146 /* The Secure Mailer license must be distributed with this software. 147 /* AUTHOR(S) 148 /* Wietse Venema 149 /* IBM T.J. Watson Research 150 /* P.O. Box 704 151 /* Yorktown Heights, NY 10598, USA 152 /*--*/ 153 154 /* System library. */ 155 156 #include <sys_defs.h> 157 #include <sys/socket.h> 158 #include <sys/time.h> /* select() */ 159 #include <unistd.h> 160 #include <signal.h> 161 #include <syslog.h> 162 #include <stdlib.h> 163 #include <limits.h> 164 #include <string.h> 165 #include <errno.h> 166 #include <fcntl.h> 167 #include <stdarg.h> 168 #ifdef STRCASECMP_IN_STRINGS_H 169 #include <strings.h> 170 #endif 171 #include <time.h> 172 173 #ifdef USE_SYS_SELECT_H 174 #include <sys/select.h> /* select() */ 175 #endif 176 177 /* Utility library. */ 178 179 #include <msg.h> 180 #include <msg_syslog.h> 181 #include <msg_vstream.h> 182 #include <chroot_uid.h> 183 #include <listen.h> 184 #include <events.h> 185 #include <vstring.h> 186 #include <vstream.h> 187 #include <msg_vstream.h> 188 #include <mymalloc.h> 189 #include <iostuff.h> 190 #include <stringops.h> 191 #include <sane_accept.h> 192 #include <myflock.h> 193 #include <safe_open.h> 194 #include <listen.h> 195 #include <watchdog.h> 196 #include <split_at.h> 197 198 /* Global library. */ 199 200 #include <mail_task.h> 201 #include <debug_process.h> 202 #include <mail_params.h> 203 #include <mail_conf.h> 204 #include <mail_dict.h> 205 #include <timed_ipc.h> 206 #include <resolve_local.h> 207 #include <mail_flow.h> 208 209 /* Process manager. */ 210 211 #include "master_proto.h" 212 213 /* Application-specific */ 214 215 #include "mail_server.h" 216 217 /* 218 * Global state. 219 */ 220 static int client_count; 221 static int use_count; 222 static int socket_count = 1; 223 224 static void (*multi_server_service) (VSTREAM *, char *, char **); 225 static char *multi_server_name; 226 static char **multi_server_argv; 227 static void (*multi_server_accept) (int, char *); 228 static void (*multi_server_onexit) (char *, char **); 229 static void (*multi_server_pre_accept) (char *, char **); 230 static VSTREAM *multi_server_lock; 231 static int multi_server_in_flow_delay; 232 static unsigned multi_server_generation; 233 static void (*multi_server_pre_disconn) (VSTREAM *, char *, char **); 234 235 /* multi_server_exit - normal termination */ 236 237 static NORETURN multi_server_exit(void) 238 { 239 if (multi_server_onexit) 240 multi_server_onexit(multi_server_name, multi_server_argv); 241 exit(0); 242 } 243 244 /* multi_server_abort - terminate after abnormal master exit */ 245 246 static void multi_server_abort(int unused_event, char *unused_context) 247 { 248 if (msg_verbose) 249 msg_info("master disconnect -- exiting"); 250 multi_server_exit(); 251 } 252 253 /* multi_server_timeout - idle time exceeded */ 254 255 static void multi_server_timeout(int unused_event, char *unused_context) 256 { 257 if (msg_verbose) 258 msg_info("idle timeout -- exiting"); 259 multi_server_exit(); 260 } 261 262 /* multi_server_drain - stop accepting new clients */ 263 264 int multi_server_drain(void) 265 { 266 int fd; 267 268 switch (fork()) { 269 /* Try again later. */ 270 case -1: 271 return (-1); 272 /* Finish existing clients in the background, then terminate. */ 273 case 0: 274 (void) msg_cleanup((MSG_CLEANUP_FN) 0); 275 for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) 276 event_disable_readwrite(fd); 277 var_use_limit = 1; 278 return (0); 279 /* Let the master start a new process. */ 280 default: 281 exit(0); 282 } 283 } 284 285 /* multi_server_disconnect - terminate client session */ 286 287 void multi_server_disconnect(VSTREAM *stream) 288 { 289 if (msg_verbose) 290 msg_info("connection closed fd %d", vstream_fileno(stream)); 291 if (multi_server_pre_disconn) 292 multi_server_pre_disconn(stream, multi_server_name, multi_server_argv); 293 event_disable_readwrite(vstream_fileno(stream)); 294 (void) vstream_fclose(stream); 295 client_count--; 296 use_count++; 297 } 298 299 /* multi_server_execute - in case (char *) != (struct *) */ 300 301 static void multi_server_execute(int unused_event, char *context) 302 { 303 VSTREAM *stream = (VSTREAM *) context; 304 305 if (multi_server_lock != 0 306 && myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK, 307 MYFLOCK_OP_NONE) < 0) 308 msg_fatal("select unlock: %m"); 309 310 /* 311 * Do not bother the application when the client disconnected. Don't drop 312 * the already accepted client request after "postfix reload"; that would 313 * be rude. 314 */ 315 if (peekfd(vstream_fileno(stream)) > 0) { 316 if (master_notify(var_pid, multi_server_generation, MASTER_STAT_TAKEN) < 0) 317 /* void */ ; 318 multi_server_service(stream, multi_server_name, multi_server_argv); 319 if (master_notify(var_pid, multi_server_generation, MASTER_STAT_AVAIL) < 0) 320 multi_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT); 321 } else { 322 multi_server_disconnect(stream); 323 } 324 if (client_count == 0 && var_idle_limit > 0) 325 event_request_timer(multi_server_timeout, (char *) 0, var_idle_limit); 326 } 327 328 /* multi_server_enable_read - enable read events */ 329 330 static void multi_server_enable_read(int unused_event, char *context) 331 { 332 VSTREAM *stream = (VSTREAM *) context; 333 334 event_enable_read(vstream_fileno(stream), multi_server_execute, (char *) stream); 335 } 336 337 /* multi_server_wakeup - wake up application */ 338 339 static void multi_server_wakeup(int fd) 340 { 341 VSTREAM *stream; 342 char *tmp; 343 344 #if defined(F_DUPFD) && (EVENTS_STYLE != EVENTS_STYLE_SELECT) 345 #ifndef THRESHOLD_FD_WORKAROUND 346 #define THRESHOLD_FD_WORKAROUND 128 347 #endif 348 int new_fd; 349 350 /* 351 * Leave some handles < FD_SETSIZE for DBMS libraries, in the unlikely 352 * case of a multi-server with a thousand clients. 353 */ 354 if (fd < THRESHOLD_FD_WORKAROUND) { 355 if ((new_fd = fcntl(fd, F_DUPFD, THRESHOLD_FD_WORKAROUND)) < 0) 356 msg_fatal("fcntl F_DUPFD: %m"); 357 (void) close(fd); 358 fd = new_fd; 359 } 360 #endif 361 if (msg_verbose) 362 msg_info("connection established fd %d", fd); 363 non_blocking(fd, BLOCKING); 364 close_on_exec(fd, CLOSE_ON_EXEC); 365 client_count++; 366 stream = vstream_fdopen(fd, O_RDWR); 367 tmp = concatenate(multi_server_name, " socket", (char *) 0); 368 vstream_control(stream, VSTREAM_CTL_PATH, tmp, VSTREAM_CTL_END); 369 myfree(tmp); 370 timed_ipc_setup(stream); 371 if (multi_server_in_flow_delay && mail_flow_get(1) < 0) 372 event_request_timer(multi_server_enable_read, (char *) stream, 373 var_in_flow_delay); 374 else 375 multi_server_enable_read(0, (char *) stream); 376 } 377 378 /* multi_server_accept_local - accept client connection request */ 379 380 static void multi_server_accept_local(int unused_event, char *context) 381 { 382 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 383 int time_left = -1; 384 int fd; 385 386 /* 387 * Be prepared for accept() to fail because some other process already 388 * got the connection (the number of processes competing for clients is 389 * kept small, so this is not a "thundering herd" problem). If the 390 * accept() succeeds, be sure to disable non-blocking I/O, in order to 391 * minimize confusion. 392 */ 393 if (client_count == 0 && var_idle_limit > 0) 394 time_left = event_cancel_timer(multi_server_timeout, (char *) 0); 395 396 if (multi_server_pre_accept) 397 multi_server_pre_accept(multi_server_name, multi_server_argv); 398 fd = LOCAL_ACCEPT(listen_fd); 399 if (multi_server_lock != 0 400 && myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK, 401 MYFLOCK_OP_NONE) < 0) 402 msg_fatal("select unlock: %m"); 403 if (fd < 0) { 404 if (errno != EAGAIN) 405 msg_error("accept connection: %m"); 406 if (time_left >= 0) 407 event_request_timer(multi_server_timeout, (char *) 0, time_left); 408 return; 409 } 410 multi_server_wakeup(fd); 411 } 412 413 #ifdef MASTER_XPORT_NAME_PASS 414 415 /* multi_server_accept_pass - accept descriptor */ 416 417 static void multi_server_accept_pass(int unused_event, char *context) 418 { 419 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 420 int time_left = -1; 421 int fd; 422 423 /* 424 * Be prepared for accept() to fail because some other process already 425 * got the connection (the number of processes competing for clients is 426 * kept small, so this is not a "thundering herd" problem). If the 427 * accept() succeeds, be sure to disable non-blocking I/O, in order to 428 * minimize confusion. 429 */ 430 if (client_count == 0 && var_idle_limit > 0) 431 time_left = event_cancel_timer(multi_server_timeout, (char *) 0); 432 433 if (multi_server_pre_accept) 434 multi_server_pre_accept(multi_server_name, multi_server_argv); 435 fd = PASS_ACCEPT(listen_fd); 436 if (multi_server_lock != 0 437 && myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK, 438 MYFLOCK_OP_NONE) < 0) 439 msg_fatal("select unlock: %m"); 440 if (fd < 0) { 441 if (errno != EAGAIN) 442 msg_error("accept connection: %m"); 443 if (time_left >= 0) 444 event_request_timer(multi_server_timeout, (char *) 0, time_left); 445 return; 446 } 447 multi_server_wakeup(fd); 448 } 449 450 #endif 451 452 /* multi_server_accept_inet - accept client connection request */ 453 454 static void multi_server_accept_inet(int unused_event, char *context) 455 { 456 int listen_fd = CAST_CHAR_PTR_TO_INT(context); 457 int time_left = -1; 458 int fd; 459 460 /* 461 * Be prepared for accept() to fail because some other process already 462 * got the connection (the number of processes competing for clients is 463 * kept small, so this is not a "thundering herd" problem). If the 464 * accept() succeeds, be sure to disable non-blocking I/O, in order to 465 * minimize confusion. 466 */ 467 if (client_count == 0 && var_idle_limit > 0) 468 time_left = event_cancel_timer(multi_server_timeout, (char *) 0); 469 470 if (multi_server_pre_accept) 471 multi_server_pre_accept(multi_server_name, multi_server_argv); 472 fd = inet_accept(listen_fd); 473 if (multi_server_lock != 0 474 && myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK, 475 MYFLOCK_OP_NONE) < 0) 476 msg_fatal("select unlock: %m"); 477 if (fd < 0) { 478 if (errno != EAGAIN) 479 msg_error("accept connection: %m"); 480 if (time_left >= 0) 481 event_request_timer(multi_server_timeout, (char *) 0, time_left); 482 return; 483 } 484 multi_server_wakeup(fd); 485 } 486 487 /* multi_server_main - the real main program */ 488 489 NORETURN multi_server_main(int argc, char **argv, MULTI_SERVER_FN service,...) 490 { 491 const char *myname = "multi_server_main"; 492 VSTREAM *stream = 0; 493 char *root_dir = 0; 494 char *user_name = 0; 495 int debug_me = 0; 496 int daemon_mode = 1; 497 char *service_name = basename(argv[0]); 498 int delay; 499 int c; 500 int fd; 501 va_list ap; 502 MAIL_SERVER_INIT_FN pre_init = 0; 503 MAIL_SERVER_INIT_FN post_init = 0; 504 MAIL_SERVER_LOOP_FN loop = 0; 505 int key; 506 char *transport = 0; 507 508 #if 0 509 char *lock_path; 510 VSTRING *why; 511 512 #endif 513 int alone = 0; 514 int zerolimit = 0; 515 WATCHDOG *watchdog; 516 char *oname; 517 char *oval; 518 char *generation; 519 int msg_vstream_needed = 0; 520 int redo_syslog_init = 0; 521 522 /* 523 * Process environment options as early as we can. 524 */ 525 if (getenv(CONF_ENV_VERB)) 526 msg_verbose = 1; 527 if (getenv(CONF_ENV_DEBUG)) 528 debug_me = 1; 529 530 /* 531 * Don't die when a process goes away unexpectedly. 532 */ 533 signal(SIGPIPE, SIG_IGN); 534 535 /* 536 * Don't die for frivolous reasons. 537 */ 538 #ifdef SIGXFSZ 539 signal(SIGXFSZ, SIG_IGN); 540 #endif 541 542 /* 543 * May need this every now and then. 544 */ 545 var_procname = mystrdup(basename(argv[0])); 546 set_mail_conf_str(VAR_PROCNAME, var_procname); 547 548 /* 549 * Initialize logging and exit handler. Do the syslog first, so that its 550 * initialization completes before we enter the optional chroot jail. 551 */ 552 msg_syslog_init(mail_task(var_procname), LOG_PID, LOG_FACILITY); 553 if (msg_verbose) 554 msg_info("daemon started"); 555 556 /* 557 * Initialize from the configuration file. Allow command-line options to 558 * override compiled-in defaults or configured parameter values. 559 */ 560 mail_conf_suck(); 561 562 /* 563 * Register dictionaries that use higher-level interfaces and protocols. 564 */ 565 mail_dict_init(); 566 567 /* 568 * Pick up policy settings from master process. Shut up error messages to 569 * stderr, because no-one is going to see them. 570 */ 571 opterr = 0; 572 while ((c = GETOPT(argc, argv, "cdDi:lm:n:o:s:St:uvVz")) > 0) { 573 switch (c) { 574 case 'c': 575 root_dir = "setme"; 576 break; 577 case 'd': 578 daemon_mode = 0; 579 break; 580 case 'D': 581 debug_me = 1; 582 break; 583 case 'i': 584 mail_conf_update(VAR_MAX_IDLE, optarg); 585 break; 586 case 'l': 587 alone = 1; 588 break; 589 case 'm': 590 mail_conf_update(VAR_MAX_USE, optarg); 591 break; 592 case 'n': 593 service_name = optarg; 594 break; 595 case 'o': 596 /* XXX Use split_nameval() */ 597 oname = mystrdup(optarg); 598 if ((oval = split_at(oname, '=')) == 0) 599 oval = ""; 600 mail_conf_update(oname, oval); 601 if (strcmp(oname, VAR_SYSLOG_NAME) == 0) 602 redo_syslog_init = 1; 603 break; 604 case 's': 605 if ((socket_count = atoi(optarg)) <= 0) 606 msg_fatal("invalid socket_count: %s", optarg); 607 break; 608 case 'S': 609 stream = VSTREAM_IN; 610 break; 611 case 'u': 612 user_name = "setme"; 613 break; 614 case 't': 615 transport = optarg; 616 break; 617 case 'v': 618 msg_verbose++; 619 break; 620 case 'V': 621 if (++msg_vstream_needed == 1) 622 msg_vstream_init(mail_task(var_procname), VSTREAM_ERR); 623 break; 624 case 'z': 625 zerolimit = 1; 626 break; 627 default: 628 msg_fatal("invalid option: %c", c); 629 break; 630 } 631 } 632 633 /* 634 * Initialize generic parameters. 635 */ 636 mail_params_init(); 637 if (redo_syslog_init) 638 msg_syslog_init(mail_task(var_procname), LOG_PID, LOG_FACILITY); 639 640 /* 641 * If not connected to stdin, stdin must not be a terminal. 642 */ 643 if (daemon_mode && stream == 0 && isatty(STDIN_FILENO)) { 644 msg_vstream_init(var_procname, VSTREAM_ERR); 645 msg_fatal("do not run this command by hand"); 646 } 647 648 /* 649 * Application-specific initialization. 650 */ 651 va_start(ap, service); 652 while ((key = va_arg(ap, int)) != 0) { 653 switch (key) { 654 case MAIL_SERVER_INT_TABLE: 655 get_mail_conf_int_table(va_arg(ap, CONFIG_INT_TABLE *)); 656 break; 657 case MAIL_SERVER_STR_TABLE: 658 get_mail_conf_str_table(va_arg(ap, CONFIG_STR_TABLE *)); 659 break; 660 case MAIL_SERVER_BOOL_TABLE: 661 get_mail_conf_bool_table(va_arg(ap, CONFIG_BOOL_TABLE *)); 662 break; 663 case MAIL_SERVER_TIME_TABLE: 664 get_mail_conf_time_table(va_arg(ap, CONFIG_TIME_TABLE *)); 665 break; 666 case MAIL_SERVER_RAW_TABLE: 667 get_mail_conf_raw_table(va_arg(ap, CONFIG_RAW_TABLE *)); 668 break; 669 case MAIL_SERVER_NINT_TABLE: 670 get_mail_conf_nint_table(va_arg(ap, CONFIG_NINT_TABLE *)); 671 break; 672 case MAIL_SERVER_PRE_INIT: 673 pre_init = va_arg(ap, MAIL_SERVER_INIT_FN); 674 break; 675 case MAIL_SERVER_POST_INIT: 676 post_init = va_arg(ap, MAIL_SERVER_INIT_FN); 677 break; 678 case MAIL_SERVER_LOOP: 679 loop = va_arg(ap, MAIL_SERVER_LOOP_FN); 680 break; 681 case MAIL_SERVER_EXIT: 682 multi_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN); 683 break; 684 case MAIL_SERVER_PRE_ACCEPT: 685 multi_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN); 686 break; 687 case MAIL_SERVER_PRE_DISCONN: 688 multi_server_pre_disconn = va_arg(ap, MAIL_SERVER_DISCONN_FN); 689 break; 690 case MAIL_SERVER_IN_FLOW_DELAY: 691 multi_server_in_flow_delay = 1; 692 break; 693 case MAIL_SERVER_SOLITARY: 694 if (stream == 0 && !alone) 695 msg_fatal("service %s requires a process limit of 1", 696 service_name); 697 break; 698 case MAIL_SERVER_UNLIMITED: 699 if (stream == 0 && !zerolimit) 700 msg_fatal("service %s requires a process limit of 0", 701 service_name); 702 break; 703 case MAIL_SERVER_PRIVILEGED: 704 if (user_name) 705 msg_fatal("service %s requires privileged operation", 706 service_name); 707 break; 708 default: 709 msg_panic("%s: unknown argument type: %d", myname, key); 710 } 711 } 712 va_end(ap); 713 714 if (root_dir) 715 root_dir = var_queue_dir; 716 if (user_name) 717 user_name = var_mail_owner; 718 719 /* 720 * Can options be required? 721 */ 722 if (stream == 0) { 723 if (transport == 0) 724 msg_fatal("no transport type specified"); 725 if (strcasecmp(transport, MASTER_XPORT_NAME_INET) == 0) 726 multi_server_accept = multi_server_accept_inet; 727 else if (strcasecmp(transport, MASTER_XPORT_NAME_UNIX) == 0) 728 multi_server_accept = multi_server_accept_local; 729 #ifdef MASTER_XPORT_NAME_PASS 730 else if (strcasecmp(transport, MASTER_XPORT_NAME_PASS) == 0) 731 multi_server_accept = multi_server_accept_pass; 732 #endif 733 else 734 msg_fatal("unsupported transport type: %s", transport); 735 } 736 737 /* 738 * Retrieve process generation from environment. 739 */ 740 if ((generation = getenv(MASTER_GEN_NAME)) != 0) { 741 if (!alldig(generation)) 742 msg_fatal("bad generation: %s", generation); 743 OCTAL_TO_UNSIGNED(multi_server_generation, generation); 744 if (msg_verbose) 745 msg_info("process generation: %s (%o)", 746 generation, multi_server_generation); 747 } 748 749 /* 750 * Optionally start the debugger on ourself. 751 */ 752 if (debug_me) 753 debug_process(); 754 755 /* 756 * Traditionally, BSD select() can't handle multiple processes selecting 757 * on the same socket, and wakes up every process in select(). See TCP/IP 758 * Illustrated volume 2 page 532. We avoid select() collisions with an 759 * external lock file. 760 */ 761 762 /* 763 * XXX Can't compete for exclusive access to the listen socket because we 764 * also have to monitor existing client connections for service requests. 765 */ 766 #if 0 767 if (stream == 0 && !alone) { 768 lock_path = concatenate(DEF_PID_DIR, "/", transport, 769 ".", service_name, (char *) 0); 770 why = vstring_alloc(1); 771 if ((multi_server_lock = safe_open(lock_path, O_CREAT | O_RDWR, 0600, 772 (struct stat *) 0, -1, -1, why)) == 0) 773 msg_fatal("open lock file %s: %s", lock_path, vstring_str(why)); 774 close_on_exec(vstream_fileno(multi_server_lock), CLOSE_ON_EXEC); 775 myfree(lock_path); 776 vstring_free(why); 777 } 778 #endif 779 780 /* 781 * Set up call-back info. 782 */ 783 multi_server_service = service; 784 multi_server_name = service_name; 785 multi_server_argv = argv + optind; 786 787 /* 788 * Run pre-jail initialization. 789 */ 790 if (chdir(var_queue_dir) < 0) 791 msg_fatal("chdir(\"%s\"): %m", var_queue_dir); 792 if (pre_init) 793 pre_init(multi_server_name, multi_server_argv); 794 795 /* 796 * Optionally, restrict the damage that this process can do. 797 */ 798 resolve_local_init(); 799 tzset(); 800 chroot_uid(root_dir, user_name); 801 802 /* 803 * Run post-jail initialization. 804 */ 805 if (post_init) 806 post_init(multi_server_name, multi_server_argv); 807 808 /* 809 * Are we running as a one-shot server with the client connection on 810 * standard input? If so, make sure the output is written to stdout so as 811 * to satisfy common expectation. 812 */ 813 if (stream != 0) { 814 vstream_control(stream, 815 VSTREAM_CTL_DOUBLE, 816 VSTREAM_CTL_WRITE_FD, STDOUT_FILENO, 817 VSTREAM_CTL_END); 818 service(stream, multi_server_name, multi_server_argv); 819 vstream_fflush(stream); 820 multi_server_exit(); 821 } 822 823 /* 824 * Running as a semi-resident server. Service connection requests. 825 * Terminate when we have serviced a sufficient number of clients, when 826 * no-one has been talking to us for a configurable amount of time, or 827 * when the master process terminated abnormally. 828 */ 829 if (var_idle_limit > 0) 830 event_request_timer(multi_server_timeout, (char *) 0, var_idle_limit); 831 for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) { 832 event_enable_read(fd, multi_server_accept, CAST_INT_TO_CHAR_PTR(fd)); 833 close_on_exec(fd, CLOSE_ON_EXEC); 834 } 835 event_enable_read(MASTER_STATUS_FD, multi_server_abort, (char *) 0); 836 close_on_exec(MASTER_STATUS_FD, CLOSE_ON_EXEC); 837 close_on_exec(MASTER_FLOW_READ, CLOSE_ON_EXEC); 838 close_on_exec(MASTER_FLOW_WRITE, CLOSE_ON_EXEC); 839 watchdog = watchdog_create(var_daemon_timeout, (WATCHDOG_FN) 0, (char *) 0); 840 841 /* 842 * The event loop, at last. 843 */ 844 while (var_use_limit == 0 || use_count < var_use_limit || client_count > 0) { 845 if (multi_server_lock != 0) { 846 watchdog_stop(watchdog); 847 if (myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK, 848 MYFLOCK_OP_EXCLUSIVE) < 0) 849 msg_fatal("select lock: %m"); 850 } 851 watchdog_start(watchdog); 852 delay = loop ? loop(multi_server_name, multi_server_argv) : -1; 853 event_loop(delay); 854 } 855 multi_server_exit(); 856 } 857