xref: /netbsd-src/external/ibm-public/postfix/dist/src/master/multi_server.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: multi_server.c,v 1.3 2020/03/18 19:05:16 christos 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 /*	Optional connection attributes are provided as a hash that
41 /*	is attached as stream context. NOTE: the attributes are
42 /*	destroyed after this function is called.
43 /*	The service name argument corresponds to the service name in the
44 /*	master.cf file.
45 /*	The argv argument specifies command-line arguments left over
46 /*	after options processing.
47 /* .PP
48 /*	Optional arguments are specified as a null-terminated list
49 /*	with macros that have zero or more arguments:
50 /* .IP "CA_MAIL_SERVER_INT_TABLE(CONFIG_INT_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_LONG_TABLE(CONFIG_LONG_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_STR_TABLE(CONFIG_STR_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_BOOL_TABLE(CONFIG_BOOL_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_TIME_TABLE(CONFIG_TIME_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.
75 /* .IP "CA_MAIL_SERVER_RAW_TABLE(CONFIG_RAW_TABLE *)"
76 /*	A table with configurable parameters, to be loaded from the
77 /*	global Postfix configuration file. Tables are loaded in the
78 /*	order as specified, and multiple instances of the same type
79 /*	are allowed. Raw parameters are not subjected to $name
80 /*	evaluation.
81 /* .IP "CA_MAIL_SERVER_NINT_TABLE(CONFIG_NINT_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_NBOOL_TABLE(CONFIG_NBOOL_TABLE *)"
87 /*	A table with configurable parameters, to be loaded from the
88 /*	global Postfix configuration file. Tables are loaded in the
89 /*	order as specified, and multiple instances of the same type
90 /*	are allowed.
91 /* .IP "CA_MAIL_SERVER_PRE_INIT(void *(char *service_name, char **argv))"
92 /*	A pointer to a function that is called once
93 /*	by the skeleton after it has read the global configuration file
94 /*	and after it has processed command-line arguments, but before
95 /*	the skeleton has optionally relinquished the process privileges.
96 /* .sp
97 /*	Only the last instance of this parameter type is remembered.
98 /* .IP "CA_MAIL_SERVER_POST_INIT(void *(char *service_name, char **argv))"
99 /*	A pointer to a function that is called once
100 /*	by the skeleton after it has optionally relinquished the process
101 /*	privileges, but before servicing client connection requests.
102 /* .sp
103 /*	Only the last instance of this parameter type is remembered.
104 /* .IP "CA_MAIL_SERVER_LOOP(int *(char *service_name, char **argv))"
105 /*	A pointer to function that is executed from
106 /*	within the event loop, whenever an I/O or timer event has happened,
107 /*	or whenever nothing has happened for a specified amount of time.
108 /*	The result value of the function specifies how long to wait until
109 /*	the next event. Specify -1 to wait for "as long as it takes".
110 /* .sp
111 /*	Only the last instance of this parameter type is remembered.
112 /* .IP "CA_MAIL_SERVER_EXIT(void *(char *service_name, char **argv))"
113 /*	A pointer to function that is executed immediately before normal
114 /*	process termination.
115 /* .IP "CA_MAIL_SERVER_PRE_ACCEPT(void *(char *service_name, char **argv))"
116 /*	Function to be executed prior to accepting a new connection.
117 /* .sp
118 /*	Only the last instance of this parameter type is remembered.
119 /* .IP "CA_MAIL_SERVER_PRE_DISCONN(VSTREAM *, char *service_name, char **argv)"
120 /*	A pointer to a function that is called
121 /*	by the multi_server_disconnect() function (see below).
122 /* .sp
123 /*	Only the last instance of this parameter type is remembered.
124 /* .IP CA_MAIL_SERVER_IN_FLOW_DELAY
125 /*	Pause $in_flow_delay seconds when no "mail flow control token"
126 /*	is available. A token is consumed for each connection request.
127 /* .IP CA_MAIL_SERVER_SOLITARY
128 /*	This service must be configured with process limit of 1.
129 /* .IP CA_MAIL_SERVER_UNLIMITED
130 /*	This service must be configured with process limit of 0.
131 /* .IP CA_MAIL_SERVER_PRIVILEGED
132 /*	This service must be configured as privileged.
133 /* .IP "CA_MAIL_SERVER_BOUNCE_INIT(const char *, const char **)"
134 /*	Initialize the DSN filter for the bounce/defer service
135 /*	clients with the specified map source and map names.
136 /* .PP
137 /*	multi_server_disconnect() should be called by the application
138 /*	to close a client connection.
139 /*
140 /*	multi_server_drain() should be called when the application
141 /*	no longer wishes to accept new client connections. Existing
142 /*	clients are handled in a background process, and the process
143 /*	terminates when the last client is disconnected. A non-zero
144 /*	result means this call should be tried again later.
145 /*
146 /*	The var_use_limit variable limits the number of clients that
147 /*	a server can service before it commits suicide.
148 /*	This value is taken from the global \fBmain.cf\fR configuration
149 /*	file. Setting \fBvar_use_limit\fR to zero disables the client limit.
150 /*
151 /*	The var_idle_limit variable limits the time that a service
152 /*	receives no client connection requests before it commits suicide.
153 /*	This value is taken from the global \fBmain.cf\fR configuration
154 /*	file. Setting \fBvar_idle_limit\fR to zero disables the idle limit.
155 /* DIAGNOSTICS
156 /*	Problems and transactions are logged to \fBsyslogd\fR(8)
157 /*	or \fBpostlogd\fR(8).
158 /* SEE ALSO
159 /*	master(8), master process
160 /*	postlogd(8), Postfix logging
161 /*	syslogd(8), system logging
162 /* LICENSE
163 /* .ad
164 /* .fi
165 /*	The Secure Mailer license must be distributed with this software.
166 /* AUTHOR(S)
167 /*	Wietse Venema
168 /*	IBM T.J. Watson Research
169 /*	P.O. Box 704
170 /*	Yorktown Heights, NY 10598, USA
171 /*
172 /*	Wietse Venema
173 /*	Google, Inc.
174 /*	111 8th Avenue
175 /*	New York, NY 10011, USA
176 /*--*/
177 
178 /* System library. */
179 
180 #include <sys_defs.h>
181 #include <sys/socket.h>
182 #include <sys/time.h>			/* select() */
183 #include <unistd.h>
184 #include <signal.h>
185 #include <stdlib.h>
186 #include <limits.h>
187 #include <string.h>
188 #include <errno.h>
189 #include <fcntl.h>
190 #include <stdarg.h>
191 #ifdef STRCASECMP_IN_STRINGS_H
192 #include <strings.h>
193 #endif
194 #include <time.h>
195 
196 #ifdef USE_SYS_SELECT_H
197 #include <sys/select.h>			/* select() */
198 #endif
199 
200 /* Utility library. */
201 
202 #include <msg.h>
203 #include <msg_vstream.h>
204 #include <chroot_uid.h>
205 #include <listen.h>
206 #include <events.h>
207 #include <vstring.h>
208 #include <vstream.h>
209 #include <msg_vstream.h>
210 #include <mymalloc.h>
211 #include <iostuff.h>
212 #include <stringops.h>
213 #include <sane_accept.h>
214 #include <myflock.h>
215 #include <safe_open.h>
216 #include <listen.h>
217 #include <watchdog.h>
218 #include <split_at.h>
219 
220 /* Global library. */
221 
222 #include <mail_task.h>
223 #include <debug_process.h>
224 #include <mail_params.h>
225 #include <mail_conf.h>
226 #include <mail_dict.h>
227 #include <timed_ipc.h>
228 #include <resolve_local.h>
229 #include <mail_flow.h>
230 #include <mail_version.h>
231 #include <bounce.h>
232 #include <maillog_client.h>
233 
234 /* Process manager. */
235 
236 #include "master_proto.h"
237 
238 /* Application-specific */
239 
240 #include "mail_server.h"
241 
242  /*
243   * Global state.
244   */
245 static int client_count;
246 static int use_count;
247 static int socket_count = 1;
248 
249 static void (*multi_server_service) (VSTREAM *, char *, char **);
250 static char *multi_server_name;
251 static char **multi_server_argv;
252 static void (*multi_server_accept) (int, void *);
253 static void (*multi_server_onexit) (char *, char **);
254 static void (*multi_server_pre_accept) (char *, char **);
255 static VSTREAM *multi_server_lock;
256 static int multi_server_in_flow_delay;
257 static unsigned multi_server_generation;
258 static void (*multi_server_pre_disconn) (VSTREAM *, char *, char **);
259 static int multi_server_saved_flags;
260 
261 /* multi_server_exit - normal termination */
262 
263 static NORETURN multi_server_exit(void)
264 {
265     if (multi_server_onexit)
266 	multi_server_onexit(multi_server_name, multi_server_argv);
267     exit(0);
268 }
269 
270 /* multi_server_abort - terminate after abnormal master exit */
271 
272 static void multi_server_abort(int unused_event, void *unused_context)
273 {
274     if (msg_verbose)
275 	msg_info("master disconnect -- exiting");
276     multi_server_exit();
277 }
278 
279 /* multi_server_timeout - idle time exceeded */
280 
281 static void multi_server_timeout(int unused_event, void *unused_context)
282 {
283     if (msg_verbose)
284 	msg_info("idle timeout -- exiting");
285     multi_server_exit();
286 }
287 
288 /* multi_server_drain - stop accepting new clients */
289 
290 int     multi_server_drain(void)
291 {
292     const char *myname = "multi_server_drain";
293     int     fd;
294 
295     switch (fork()) {
296 	/* Try again later. */
297     case -1:
298 	return (-1);
299 	/* Finish existing clients in the background, then terminate. */
300     case 0:
301 	(void) msg_cleanup((MSG_CLEANUP_FN) 0);
302 	event_fork();
303 	for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) {
304 	    event_disable_readwrite(fd);
305 	    (void) close(fd);
306 	    /* Play safe - don't reuse this file number. */
307 	    if (DUP2(STDIN_FILENO, fd) < 0)
308 		msg_warn("%s: dup2(%d, %d): %m", myname, STDIN_FILENO, fd);
309 	}
310 	var_use_limit = 1;
311 	return (0);
312 	/* Let the master start a new process. */
313     default:
314 	exit(0);
315     }
316 }
317 
318 /* multi_server_disconnect - terminate client session */
319 
320 void    multi_server_disconnect(VSTREAM *stream)
321 {
322     if (msg_verbose)
323 	msg_info("connection closed fd %d", vstream_fileno(stream));
324     if (multi_server_pre_disconn)
325 	multi_server_pre_disconn(stream, multi_server_name, multi_server_argv);
326     event_disable_readwrite(vstream_fileno(stream));
327     (void) vstream_fclose(stream);
328     client_count--;
329     /* Avoid integer wrap-around in a persistent process.  */
330     if (use_count < INT_MAX)
331 	use_count++;
332     if (client_count == 0 && var_idle_limit > 0)
333 	event_request_timer(multi_server_timeout, (void *) 0, var_idle_limit);
334 }
335 
336 /* multi_server_execute - in case (char *) != (struct *) */
337 
338 static void multi_server_execute(int unused_event, void *context)
339 {
340     VSTREAM *stream = (VSTREAM *) context;
341     HTABLE *attr = (vstream_flags(stream) == multi_server_saved_flags ?
342 		    (HTABLE *) vstream_context(stream) : 0);
343 
344     if (multi_server_lock != 0
345 	&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
346 		   MYFLOCK_OP_NONE) < 0)
347 	msg_fatal("select unlock: %m");
348 
349     /*
350      * Do not bother the application when the client disconnected. Don't drop
351      * the already accepted client request after "postfix reload"; that would
352      * be rude.
353      */
354     if (peekfd(vstream_fileno(stream)) > 0) {
355 	if (master_notify(var_pid, multi_server_generation, MASTER_STAT_TAKEN) < 0)
356 	     /* void */ ;
357 	multi_server_service(stream, multi_server_name, multi_server_argv);
358 	if (master_notify(var_pid, multi_server_generation, MASTER_STAT_AVAIL) < 0)
359 	    multi_server_abort(EVENT_NULL_TYPE, EVENT_NULL_CONTEXT);
360     } else {
361 	multi_server_disconnect(stream);
362     }
363     if (attr)
364 	htable_free(attr, myfree);
365 }
366 
367 /* multi_server_enable_read - enable read events */
368 
369 static void multi_server_enable_read(int unused_event, void *context)
370 {
371     VSTREAM *stream = (VSTREAM *) context;
372 
373     event_enable_read(vstream_fileno(stream), multi_server_execute, (void *) stream);
374 }
375 
376 /* multi_server_wakeup - wake up application */
377 
378 static void multi_server_wakeup(int fd, HTABLE *attr)
379 {
380     VSTREAM *stream;
381     char   *tmp;
382 
383 #if defined(F_DUPFD) && (EVENTS_STYLE != EVENTS_STYLE_SELECT)
384 #ifndef THRESHOLD_FD_WORKAROUND
385 #define THRESHOLD_FD_WORKAROUND 128
386 #endif
387     int     new_fd;
388 
389     /*
390      * Leave some handles < FD_SETSIZE for DBMS libraries, in the unlikely
391      * case of a multi-server with a thousand clients.
392      */
393     if (fd < THRESHOLD_FD_WORKAROUND) {
394 	if ((new_fd = fcntl(fd, F_DUPFD, THRESHOLD_FD_WORKAROUND)) < 0)
395 	    msg_fatal("fcntl F_DUPFD: %m");
396 	(void) close(fd);
397 	fd = new_fd;
398     }
399 #endif
400     if (msg_verbose)
401 	msg_info("connection established fd %d", fd);
402     non_blocking(fd, BLOCKING);
403     close_on_exec(fd, CLOSE_ON_EXEC);
404     client_count++;
405     stream = vstream_fdopen(fd, O_RDWR);
406     tmp = concatenate(multi_server_name, " socket", (char *) 0);
407     vstream_control(stream,
408 		    CA_VSTREAM_CTL_PATH(tmp),
409 		    CA_VSTREAM_CTL_CONTEXT((void *) attr),
410 		    CA_VSTREAM_CTL_END);
411     myfree(tmp);
412     timed_ipc_setup(stream);
413     multi_server_saved_flags = vstream_flags(stream);
414     if (multi_server_in_flow_delay && mail_flow_get(1) < 0)
415 	event_request_timer(multi_server_enable_read, (void *) stream,
416 			    var_in_flow_delay);
417     else
418 	multi_server_enable_read(0, (void *) stream);
419 }
420 
421 /* multi_server_accept_local - accept client connection request */
422 
423 static void multi_server_accept_local(int unused_event, void *context)
424 {
425     int     listen_fd = CAST_ANY_PTR_TO_INT(context);
426     int     time_left = -1;
427     int     fd;
428 
429     /*
430      * Be prepared for accept() to fail because some other process already
431      * got the connection (the number of processes competing for clients is
432      * kept small, so this is not a "thundering herd" problem). If the
433      * accept() succeeds, be sure to disable non-blocking I/O, in order to
434      * minimize confusion.
435      */
436     if (client_count == 0 && var_idle_limit > 0)
437 	time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
438 
439     if (multi_server_pre_accept)
440 	multi_server_pre_accept(multi_server_name, multi_server_argv);
441     fd = LOCAL_ACCEPT(listen_fd);
442     if (multi_server_lock != 0
443 	&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
444 		   MYFLOCK_OP_NONE) < 0)
445 	msg_fatal("select unlock: %m");
446     if (fd < 0) {
447 	if (errno != EAGAIN)
448 	    msg_error("accept connection: %m");
449 	if (time_left >= 0)
450 	    event_request_timer(multi_server_timeout, (void *) 0, time_left);
451 	return;
452     }
453     multi_server_wakeup(fd, (HTABLE *) 0);
454 }
455 
456 #ifdef MASTER_XPORT_NAME_PASS
457 
458 /* multi_server_accept_pass - accept descriptor */
459 
460 static void multi_server_accept_pass(int unused_event, void *context)
461 {
462     int     listen_fd = CAST_ANY_PTR_TO_INT(context);
463     int     time_left = -1;
464     int     fd;
465     HTABLE *attr = 0;
466 
467     /*
468      * Be prepared for accept() to fail because some other process already
469      * got the connection (the number of processes competing for clients is
470      * kept small, so this is not a "thundering herd" problem). If the
471      * accept() succeeds, be sure to disable non-blocking I/O, in order to
472      * minimize confusion.
473      */
474     if (client_count == 0 && var_idle_limit > 0)
475 	time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
476 
477     if (multi_server_pre_accept)
478 	multi_server_pre_accept(multi_server_name, multi_server_argv);
479     fd = pass_accept_attr(listen_fd, &attr);
480     if (multi_server_lock != 0
481 	&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
482 		   MYFLOCK_OP_NONE) < 0)
483 	msg_fatal("select unlock: %m");
484     if (fd < 0) {
485 	if (errno != EAGAIN)
486 	    msg_error("accept connection: %m");
487 	if (time_left >= 0)
488 	    event_request_timer(multi_server_timeout, (void *) 0, time_left);
489 	return;
490     }
491     multi_server_wakeup(fd, attr);
492 }
493 
494 #endif
495 
496 /* multi_server_accept_inet - accept client connection request */
497 
498 static void multi_server_accept_inet(int unused_event, void *context)
499 {
500     int     listen_fd = CAST_ANY_PTR_TO_INT(context);
501     int     time_left = -1;
502     int     fd;
503 
504     /*
505      * Be prepared for accept() to fail because some other process already
506      * got the connection (the number of processes competing for clients is
507      * kept small, so this is not a "thundering herd" problem). If the
508      * accept() succeeds, be sure to disable non-blocking I/O, in order to
509      * minimize confusion.
510      */
511     if (client_count == 0 && var_idle_limit > 0)
512 	time_left = event_cancel_timer(multi_server_timeout, (void *) 0);
513 
514     if (multi_server_pre_accept)
515 	multi_server_pre_accept(multi_server_name, multi_server_argv);
516     fd = inet_accept(listen_fd);
517     if (multi_server_lock != 0
518 	&& myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
519 		   MYFLOCK_OP_NONE) < 0)
520 	msg_fatal("select unlock: %m");
521     if (fd < 0) {
522 	if (errno != EAGAIN)
523 	    msg_error("accept connection: %m");
524 	if (time_left >= 0)
525 	    event_request_timer(multi_server_timeout, (void *) 0, time_left);
526 	return;
527     }
528     multi_server_wakeup(fd, (HTABLE *) 0);
529 }
530 
531 /* multi_server_main - the real main program */
532 
533 NORETURN multi_server_main(int argc, char **argv, MULTI_SERVER_FN service,...)
534 {
535     const char *myname = "multi_server_main";
536     VSTREAM *stream = 0;
537     char   *root_dir = 0;
538     char   *user_name = 0;
539     int     debug_me = 0;
540     int     daemon_mode = 1;
541     char   *service_name = basename(argv[0]);
542     int     delay;
543     int     c;
544     int     fd;
545     va_list ap;
546     MAIL_SERVER_INIT_FN pre_init = 0;
547     MAIL_SERVER_INIT_FN post_init = 0;
548     MAIL_SERVER_LOOP_FN loop = 0;
549     int     key;
550     char   *transport = 0;
551 
552 #if 0
553     char   *lock_path;
554     VSTRING *why;
555 
556 #endif
557     int     alone = 0;
558     int     zerolimit = 0;
559     WATCHDOG *watchdog;
560     char   *oname_val;
561     char   *oname;
562     char   *oval;
563     const char *err;
564     char   *generation;
565     int     msg_vstream_needed = 0;
566     const char *dsn_filter_title;
567     const char **dsn_filter_maps;
568 
569     /*
570      * Process environment options as early as we can.
571      */
572     if (getenv(CONF_ENV_VERB))
573 	msg_verbose = 1;
574     if (getenv(CONF_ENV_DEBUG))
575 	debug_me = 1;
576 
577     /*
578      * Don't die when a process goes away unexpectedly.
579      */
580     signal(SIGPIPE, SIG_IGN);
581 
582     /*
583      * Don't die for frivolous reasons.
584      */
585 #ifdef SIGXFSZ
586     signal(SIGXFSZ, SIG_IGN);
587 #endif
588 
589     /*
590      * May need this every now and then.
591      */
592     var_procname = mystrdup(basename(argv[0]));
593     set_mail_conf_str(VAR_PROCNAME, var_procname);
594 
595     /*
596      * Initialize logging and exit handler. Do the syslog first, so that its
597      * initialization completes before we enter the optional chroot jail.
598      */
599     maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE);
600     if (msg_verbose)
601 	msg_info("daemon started");
602 
603     /*
604      * Check the Postfix library version as soon as we enable logging.
605      */
606     MAIL_VERSION_CHECK;
607 
608     /*
609      * Initialize from the configuration file. Allow command-line options to
610      * override compiled-in defaults or configured parameter values.
611      */
612     mail_conf_suck();
613 
614     /*
615      * After database open error, continue execution with reduced
616      * functionality.
617      */
618     dict_allow_surrogate = 1;
619 
620     /*
621      * Pick up policy settings from master process. Shut up error messages to
622      * stderr, because no-one is going to see them.
623      */
624     opterr = 0;
625     while ((c = GETOPT(argc, argv, "cdDi:lm:n:o:s:St:uvVz")) > 0) {
626 	switch (c) {
627 	case 'c':
628 	    root_dir = "setme";
629 	    break;
630 	case 'd':
631 	    daemon_mode = 0;
632 	    break;
633 	case 'D':
634 	    debug_me = 1;
635 	    break;
636 	case 'i':
637 	    mail_conf_update(VAR_MAX_IDLE, optarg);
638 	    break;
639 	case 'l':
640 	    alone = 1;
641 	    break;
642 	case 'm':
643 	    mail_conf_update(VAR_MAX_USE, optarg);
644 	    break;
645 	case 'n':
646 	    service_name = optarg;
647 	    break;
648 	case 'o':
649 	    oname_val = mystrdup(optarg);
650 	    if ((err = split_nameval(oname_val, &oname, &oval)) != 0)
651 		msg_fatal("invalid \"-o %s\" option value: %s", optarg, err);
652 	    mail_conf_update(oname, oval);
653 	    myfree(oname_val);
654 	    break;
655 	case 's':
656 	    if ((socket_count = atoi(optarg)) <= 0)
657 		msg_fatal("invalid socket_count: %s", optarg);
658 	    break;
659 	case 'S':
660 	    stream = VSTREAM_IN;
661 	    break;
662 	case 'u':
663 	    user_name = "setme";
664 	    break;
665 	case 't':
666 	    transport = optarg;
667 	    break;
668 	case 'v':
669 	    msg_verbose++;
670 	    break;
671 	case 'V':
672 	    if (++msg_vstream_needed == 1)
673 		msg_vstream_init(mail_task(var_procname), VSTREAM_ERR);
674 	    break;
675 	case 'z':
676 	    zerolimit = 1;
677 	    break;
678 	default:
679 	    msg_fatal("invalid option: %c", optopt);
680 	    break;
681 	}
682     }
683     set_mail_conf_str(VAR_SERVNAME, service_name);
684 
685     /*
686      * Initialize generic parameters and re-initialize logging in case of a
687      * non-default program name or logging destination.
688      */
689     mail_params_init();
690     maillog_client_init(mail_task(var_procname), MAILLOG_CLIENT_FLAG_NONE);
691 
692     /*
693      * Register higher-level dictionaries and initialize the support for
694      * dynamically-loaded dictionarles.
695      */
696     mail_dict_init();
697 
698     /*
699      * If not connected to stdin, stdin must not be a terminal.
700      */
701     if (daemon_mode && stream == 0 && isatty(STDIN_FILENO)) {
702 	msg_vstream_init(var_procname, VSTREAM_ERR);
703 	msg_fatal("do not run this command by hand");
704     }
705 
706     /*
707      * Application-specific initialization.
708      */
709     va_start(ap, service);
710     while ((key = va_arg(ap, int)) != 0) {
711 	switch (key) {
712 	case MAIL_SERVER_INT_TABLE:
713 	    get_mail_conf_int_table(va_arg(ap, CONFIG_INT_TABLE *));
714 	    break;
715 	case MAIL_SERVER_LONG_TABLE:
716 	    get_mail_conf_long_table(va_arg(ap, CONFIG_LONG_TABLE *));
717 	    break;
718 	case MAIL_SERVER_STR_TABLE:
719 	    get_mail_conf_str_table(va_arg(ap, CONFIG_STR_TABLE *));
720 	    break;
721 	case MAIL_SERVER_BOOL_TABLE:
722 	    get_mail_conf_bool_table(va_arg(ap, CONFIG_BOOL_TABLE *));
723 	    break;
724 	case MAIL_SERVER_TIME_TABLE:
725 	    get_mail_conf_time_table(va_arg(ap, CONFIG_TIME_TABLE *));
726 	    break;
727 	case MAIL_SERVER_RAW_TABLE:
728 	    get_mail_conf_raw_table(va_arg(ap, CONFIG_RAW_TABLE *));
729 	    break;
730 	case MAIL_SERVER_NINT_TABLE:
731 	    get_mail_conf_nint_table(va_arg(ap, CONFIG_NINT_TABLE *));
732 	    break;
733 	case MAIL_SERVER_NBOOL_TABLE:
734 	    get_mail_conf_nbool_table(va_arg(ap, CONFIG_NBOOL_TABLE *));
735 	    break;
736 	case MAIL_SERVER_PRE_INIT:
737 	    pre_init = va_arg(ap, MAIL_SERVER_INIT_FN);
738 	    break;
739 	case MAIL_SERVER_POST_INIT:
740 	    post_init = va_arg(ap, MAIL_SERVER_INIT_FN);
741 	    break;
742 	case MAIL_SERVER_LOOP:
743 	    loop = va_arg(ap, MAIL_SERVER_LOOP_FN);
744 	    break;
745 	case MAIL_SERVER_EXIT:
746 	    multi_server_onexit = va_arg(ap, MAIL_SERVER_EXIT_FN);
747 	    break;
748 	case MAIL_SERVER_PRE_ACCEPT:
749 	    multi_server_pre_accept = va_arg(ap, MAIL_SERVER_ACCEPT_FN);
750 	    break;
751 	case MAIL_SERVER_PRE_DISCONN:
752 	    multi_server_pre_disconn = va_arg(ap, MAIL_SERVER_DISCONN_FN);
753 	    break;
754 	case MAIL_SERVER_IN_FLOW_DELAY:
755 	    multi_server_in_flow_delay = 1;
756 	    break;
757 	case MAIL_SERVER_SOLITARY:
758 	    if (stream == 0 && !alone)
759 		msg_fatal("service %s requires a process limit of 1",
760 			  service_name);
761 	    break;
762 	case MAIL_SERVER_UNLIMITED:
763 	    if (stream == 0 && !zerolimit)
764 		msg_fatal("service %s requires a process limit of 0",
765 			  service_name);
766 	    break;
767 	case MAIL_SERVER_PRIVILEGED:
768 	    if (user_name)
769 		msg_fatal("service %s requires privileged operation",
770 			  service_name);
771 	    break;
772 	case MAIL_SERVER_BOUNCE_INIT:
773 	    dsn_filter_title = va_arg(ap, const char *);
774 	    dsn_filter_maps = va_arg(ap, const char **);
775 	    bounce_client_init(dsn_filter_title, *dsn_filter_maps);
776 	    break;
777 	default:
778 	    msg_panic("%s: unknown argument type: %d", myname, key);
779 	}
780     }
781     va_end(ap);
782 
783     if (root_dir)
784 	root_dir = var_queue_dir;
785     if (user_name)
786 	user_name = var_mail_owner;
787 
788     /*
789      * Can options be required?
790      */
791     if (stream == 0) {
792 	if (transport == 0)
793 	    msg_fatal("no transport type specified");
794 	if (strcasecmp(transport, MASTER_XPORT_NAME_INET) == 0)
795 	    multi_server_accept = multi_server_accept_inet;
796 	else if (strcasecmp(transport, MASTER_XPORT_NAME_UNIX) == 0)
797 	    multi_server_accept = multi_server_accept_local;
798 #ifdef MASTER_XPORT_NAME_PASS
799 	else if (strcasecmp(transport, MASTER_XPORT_NAME_PASS) == 0)
800 	    multi_server_accept = multi_server_accept_pass;
801 #endif
802 	else
803 	    msg_fatal("unsupported transport type: %s", transport);
804     }
805 
806     /*
807      * Retrieve process generation from environment.
808      */
809     if ((generation = getenv(MASTER_GEN_NAME)) != 0) {
810 	if (!alldig(generation))
811 	    msg_fatal("bad generation: %s", generation);
812 	OCTAL_TO_UNSIGNED(multi_server_generation, generation);
813 	if (msg_verbose)
814 	    msg_info("process generation: %s (%o)",
815 		     generation, multi_server_generation);
816     }
817 
818     /*
819      * Optionally start the debugger on ourself.
820      */
821     if (debug_me)
822 	debug_process();
823 
824     /*
825      * Traditionally, BSD select() can't handle multiple processes selecting
826      * on the same socket, and wakes up every process in select(). See TCP/IP
827      * Illustrated volume 2 page 532. We avoid select() collisions with an
828      * external lock file.
829      */
830 
831     /*
832      * XXX Can't compete for exclusive access to the listen socket because we
833      * also have to monitor existing client connections for service requests.
834      */
835 #if 0
836     if (stream == 0 && !alone) {
837 	lock_path = concatenate(DEF_PID_DIR, "/", transport,
838 				".", service_name, (char *) 0);
839 	why = vstring_alloc(1);
840 	if ((multi_server_lock = safe_open(lock_path, O_CREAT | O_RDWR, 0600,
841 				      (struct stat *) 0, -1, -1, why)) == 0)
842 	    msg_fatal("open lock file %s: %s", lock_path, vstring_str(why));
843 	close_on_exec(vstream_fileno(multi_server_lock), CLOSE_ON_EXEC);
844 	myfree(lock_path);
845 	vstring_free(why);
846     }
847 #endif
848 
849     /*
850      * Set up call-back info.
851      */
852     multi_server_service = service;
853     multi_server_name = service_name;
854     multi_server_argv = argv + optind;
855 
856     /*
857      * Run pre-jail initialization.
858      */
859     if (chdir(var_queue_dir) < 0)
860 	msg_fatal("chdir(\"%s\"): %m", var_queue_dir);
861     if (pre_init)
862 	pre_init(multi_server_name, multi_server_argv);
863 
864     /*
865      * Optionally, restrict the damage that this process can do.
866      */
867     resolve_local_init();
868     tzset();
869     chroot_uid(root_dir, user_name);
870 
871     /*
872      * Run post-jail initialization.
873      */
874     if (post_init)
875 	post_init(multi_server_name, multi_server_argv);
876 
877     /*
878      * Are we running as a one-shot server with the client connection on
879      * standard input? If so, make sure the output is written to stdout so as
880      * to satisfy common expectation.
881      */
882     if (stream != 0) {
883 	vstream_control(stream,
884 			CA_VSTREAM_CTL_DOUBLE,
885 			CA_VSTREAM_CTL_WRITE_FD(STDOUT_FILENO),
886 			CA_VSTREAM_CTL_END);
887 	service(stream, multi_server_name, multi_server_argv);
888 	vstream_fflush(stream);
889 	multi_server_exit();
890     }
891 
892     /*
893      * Running as a semi-resident server. Service connection requests.
894      * Terminate when we have serviced a sufficient number of clients, when
895      * no-one has been talking to us for a configurable amount of time, or
896      * when the master process terminated abnormally.
897      */
898     if (var_idle_limit > 0)
899 	event_request_timer(multi_server_timeout, (void *) 0, var_idle_limit);
900     for (fd = MASTER_LISTEN_FD; fd < MASTER_LISTEN_FD + socket_count; fd++) {
901 	event_enable_read(fd, multi_server_accept, CAST_INT_TO_VOID_PTR(fd));
902 	close_on_exec(fd, CLOSE_ON_EXEC);
903     }
904     event_enable_read(MASTER_STATUS_FD, multi_server_abort, (void *) 0);
905     close_on_exec(MASTER_STATUS_FD, CLOSE_ON_EXEC);
906     close_on_exec(MASTER_FLOW_READ, CLOSE_ON_EXEC);
907     close_on_exec(MASTER_FLOW_WRITE, CLOSE_ON_EXEC);
908     watchdog = watchdog_create(var_daemon_timeout, (WATCHDOG_FN) 0, (void *) 0);
909 
910     /*
911      * The event loop, at last.
912      */
913     while (var_use_limit == 0 || use_count < var_use_limit || client_count > 0) {
914 	if (multi_server_lock != 0) {
915 	    watchdog_stop(watchdog);
916 	    if (myflock(vstream_fileno(multi_server_lock), INTERNAL_LOCK,
917 			MYFLOCK_OP_EXCLUSIVE) < 0)
918 		msg_fatal("select lock: %m");
919 	}
920 	watchdog_start(watchdog);
921 	delay = loop ? loop(multi_server_name, multi_server_argv) : -1;
922 	event_loop(delay);
923     }
924     multi_server_exit();
925 }
926