1 /* $NetBSD: qmgr.c,v 1.3 2020/03/18 19:05:17 christos Exp $ */
2
3 /*++
4 /* NAME
5 /* qmgr 8
6 /* SUMMARY
7 /* old Postfix queue manager
8 /* SYNOPSIS
9 /* \fBqmgr\fR [generic Postfix daemon options]
10 /* DESCRIPTION
11 /* The \fBqmgr\fR(8) daemon awaits the arrival of incoming mail
12 /* and arranges for its delivery via Postfix delivery processes.
13 /* The actual mail routing strategy is delegated to the
14 /* \fBtrivial-rewrite\fR(8) daemon.
15 /* This program expects to be run from the \fBmaster\fR(8) process
16 /* manager.
17 /*
18 /* Mail addressed to the local \fBdouble-bounce\fR address is
19 /* logged and discarded. This stops potential loops caused by
20 /* undeliverable bounce notifications.
21 /* MAIL QUEUES
22 /* .ad
23 /* .fi
24 /* The \fBqmgr\fR(8) daemon maintains the following queues:
25 /* .IP \fBincoming\fR
26 /* Inbound mail from the network, or mail picked up by the
27 /* local \fBpickup\fR(8) agent from the \fBmaildrop\fR directory.
28 /* .IP \fBactive\fR
29 /* Messages that the queue manager has opened for delivery. Only
30 /* a limited number of messages is allowed to enter the \fBactive\fR
31 /* queue (leaky bucket strategy, for a fixed delivery rate).
32 /* .IP \fBdeferred\fR
33 /* Mail that could not be delivered upon the first attempt. The queue
34 /* manager implements exponential backoff by doubling the time between
35 /* delivery attempts.
36 /* .IP \fBcorrupt\fR
37 /* Unreadable or damaged queue files are moved here for inspection.
38 /* .IP \fBhold\fR
39 /* Messages that are kept "on hold" are kept here until someone
40 /* sets them free.
41 /* DELIVERY STATUS REPORTS
42 /* .ad
43 /* .fi
44 /* The \fBqmgr\fR(8) daemon keeps an eye on per-message delivery status
45 /* reports in the following directories. Each status report file has
46 /* the same name as the corresponding message file:
47 /* .IP \fBbounce\fR
48 /* Per-recipient status information about why mail is bounced.
49 /* These files are maintained by the \fBbounce\fR(8) daemon.
50 /* .IP \fBdefer\fR
51 /* Per-recipient status information about why mail is delayed.
52 /* These files are maintained by the \fBdefer\fR(8) daemon.
53 /* .IP \fBtrace\fR
54 /* Per-recipient status information as requested with the
55 /* Postfix "\fBsendmail -v\fR" or "\fBsendmail -bv\fR" command.
56 /* These files are maintained by the \fBtrace\fR(8) daemon.
57 /* .PP
58 /* The \fBqmgr\fR(8) daemon is responsible for asking the
59 /* \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemons to
60 /* send delivery reports.
61 /* STRATEGIES
62 /* .ad
63 /* .fi
64 /* The queue manager implements a variety of strategies for
65 /* either opening queue files (input) or for message delivery (output).
66 /* .IP "\fBleaky bucket\fR"
67 /* This strategy limits the number of messages in the \fBactive\fR queue
68 /* and prevents the queue manager from running out of memory under
69 /* heavy load.
70 /* .IP \fBfairness\fR
71 /* When the \fBactive\fR queue has room, the queue manager takes one
72 /* message from the \fBincoming\fR queue and one from the \fBdeferred\fR
73 /* queue. This prevents a large mail backlog from blocking the delivery
74 /* of new mail.
75 /* .IP "\fBslow start\fR"
76 /* This strategy eliminates "thundering herd" problems by slowly
77 /* adjusting the number of parallel deliveries to the same destination.
78 /* .IP "\fBround robin\fR"
79 /* The queue manager sorts delivery requests by destination.
80 /* Round-robin selection prevents one destination from dominating
81 /* deliveries to other destinations.
82 /* .IP "\fBexponential backoff\fR"
83 /* Mail that cannot be delivered upon the first attempt is deferred.
84 /* The time interval between delivery attempts is doubled after each
85 /* attempt.
86 /* .IP "\fBdestination status cache\fR"
87 /* The queue manager avoids unnecessary delivery attempts by
88 /* maintaining a short-term, in-memory list of unreachable destinations.
89 /* TRIGGERS
90 /* .ad
91 /* .fi
92 /* On an idle system, the queue manager waits for the arrival of
93 /* trigger events, or it waits for a timer to go off. A trigger
94 /* is a one-byte message.
95 /* Depending on the message received, the queue manager performs
96 /* one of the following actions (the message is followed by the
97 /* symbolic constant used internally by the software):
98 /* .IP "\fBD (QMGR_REQ_SCAN_DEFERRED)\fR"
99 /* Start a deferred queue scan. If a deferred queue scan is already
100 /* in progress, that scan will be restarted as soon as it finishes.
101 /* .IP "\fBI (QMGR_REQ_SCAN_INCOMING)\fR"
102 /* Start an incoming queue scan. If an incoming queue scan is already
103 /* in progress, that scan will be restarted as soon as it finishes.
104 /* .IP "\fBA (QMGR_REQ_SCAN_ALL)\fR"
105 /* Ignore deferred queue file time stamps. The request affects
106 /* the next deferred queue scan.
107 /* .IP "\fBF (QMGR_REQ_FLUSH_DEAD)\fR"
108 /* Purge all information about dead transports and destinations.
109 /* .IP "\fBW (TRIGGER_REQ_WAKEUP)\fR"
110 /* Wakeup call, This is used by the master server to instantiate
111 /* servers that should not go away forever. The action is to start
112 /* an incoming queue scan.
113 /* .PP
114 /* The \fBqmgr\fR(8) daemon reads an entire buffer worth of triggers.
115 /* Multiple identical trigger requests are collapsed into one, and
116 /* trigger requests are sorted so that \fBA\fR and \fBF\fR precede
117 /* \fBD\fR and \fBI\fR. Thus, in order to force a deferred queue run,
118 /* one would request \fBA F D\fR; in order to notify the queue manager
119 /* of the arrival of new mail one would request \fBI\fR.
120 /* STANDARDS
121 /* RFC 3463 (Enhanced status codes)
122 /* RFC 3464 (Delivery status notifications)
123 /* SECURITY
124 /* .ad
125 /* .fi
126 /* The \fBqmgr\fR(8) daemon is not security sensitive. It reads
127 /* single-character messages from untrusted local users, and thus may
128 /* be susceptible to denial of service attacks. The \fBqmgr\fR(8) daemon
129 /* does not talk to the outside world, and it can be run at fixed low
130 /* privilege in a chrooted environment.
131 /* DIAGNOSTICS
132 /* Problems and transactions are logged to the \fBsyslogd\fR(8)
133 /* or \fBpostlogd\fR(8) daemon.
134 /* Corrupted message files are saved to the \fBcorrupt\fR queue
135 /* for further inspection.
136 /*
137 /* Depending on the setting of the \fBnotify_classes\fR parameter,
138 /* the postmaster is notified of bounces and of other trouble.
139 /* BUGS
140 /* A single queue manager process has to compete for disk access with
141 /* multiple front-end processes such as \fBcleanup\fR(8). A sudden burst of
142 /* inbound mail can negatively impact outbound delivery rates.
143 /* CONFIGURATION PARAMETERS
144 /* .ad
145 /* .fi
146 /* Changes to \fBmain.cf\fR are not picked up automatically,
147 /* as \fBqmgr\fR(8)
148 /* is a persistent process. Use the command "\fBpostfix reload\fR" after
149 /* a configuration change.
150 /*
151 /* The text below provides only a parameter summary. See
152 /* \fBpostconf\fR(5) for more details including examples.
153 /*
154 /* In the text below, \fItransport\fR is the first field in a
155 /* \fBmaster.cf\fR entry.
156 /* COMPATIBILITY CONTROLS
157 /* .ad
158 /* .fi
159 /* Available before Postfix version 2.5:
160 /* .IP "\fBallow_min_user (no)\fR"
161 /* Allow a sender or recipient address to have `-' as the first
162 /* character.
163 /* .PP
164 /* Available with Postfix version 2.7 and later:
165 /* .IP "\fBdefault_filter_nexthop (empty)\fR"
166 /* When a content_filter or FILTER request specifies no explicit
167 /* next-hop destination, use $default_filter_nexthop instead; when
168 /* that value is empty, use the domain in the recipient address.
169 /* ACTIVE QUEUE CONTROLS
170 /* .ad
171 /* .fi
172 /* .IP "\fBqmgr_clog_warn_time (300s)\fR"
173 /* The minimal delay between warnings that a specific destination is
174 /* clogging up the Postfix active queue.
175 /* .IP "\fBqmgr_message_active_limit (20000)\fR"
176 /* The maximal number of messages in the active queue.
177 /* .IP "\fBqmgr_message_recipient_limit (20000)\fR"
178 /* The maximal number of recipients held in memory by the Postfix
179 /* queue manager, and the maximal size of the short-term,
180 /* in-memory "dead" destination status cache.
181 /* DELIVERY CONCURRENCY CONTROLS
182 /* .ad
183 /* .fi
184 /* .IP "\fBqmgr_fudge_factor (100)\fR"
185 /* Obsolete feature: the percentage of delivery resources that a busy
186 /* mail system will use up for delivery of a large mailing list
187 /* message.
188 /* .IP "\fBinitial_destination_concurrency (5)\fR"
189 /* The initial per-destination concurrency level for parallel delivery
190 /* to the same destination.
191 /* .IP "\fBdefault_destination_concurrency_limit (20)\fR"
192 /* The default maximal number of parallel deliveries to the same
193 /* destination.
194 /* .IP "\fBtransport_destination_concurrency_limit ($default_destination_concurrency_limit)\fR"
195 /* A transport-specific override for the
196 /* default_destination_concurrency_limit parameter value, where
197 /* \fItransport\fR is the master.cf name of the message delivery
198 /* transport.
199 /* .PP
200 /* Available in Postfix version 2.5 and later:
201 /* .IP "\fBtransport_initial_destination_concurrency ($initial_destination_concurrency)\fR"
202 /* A transport-specific override for the initial_destination_concurrency
203 /* parameter value, where \fItransport\fR is the master.cf name of
204 /* the message delivery transport.
205 /* .IP "\fBdefault_destination_concurrency_failed_cohort_limit (1)\fR"
206 /* How many pseudo-cohorts must suffer connection or handshake
207 /* failure before a specific destination is considered unavailable
208 /* (and further delivery is suspended).
209 /* .IP "\fBtransport_destination_concurrency_failed_cohort_limit ($default_destination_concurrency_failed_cohort_limit)\fR"
210 /* A transport-specific override for the
211 /* default_destination_concurrency_failed_cohort_limit parameter value,
212 /* where \fItransport\fR is the master.cf name of the message delivery
213 /* transport.
214 /* .IP "\fBdefault_destination_concurrency_negative_feedback (1)\fR"
215 /* The per-destination amount of delivery concurrency negative
216 /* feedback, after a delivery completes with a connection or handshake
217 /* failure.
218 /* .IP "\fBtransport_destination_concurrency_negative_feedback ($default_destination_concurrency_negative_feedback)\fR"
219 /* A transport-specific override for the
220 /* default_destination_concurrency_negative_feedback parameter value,
221 /* where \fItransport\fR is the master.cf name of the message delivery
222 /* transport.
223 /* .IP "\fBdefault_destination_concurrency_positive_feedback (1)\fR"
224 /* The per-destination amount of delivery concurrency positive
225 /* feedback, after a delivery completes without connection or handshake
226 /* failure.
227 /* .IP "\fBtransport_destination_concurrency_positive_feedback ($default_destination_concurrency_positive_feedback)\fR"
228 /* A transport-specific override for the
229 /* default_destination_concurrency_positive_feedback parameter value,
230 /* where \fItransport\fR is the master.cf name of the message delivery
231 /* transport.
232 /* .IP "\fBdestination_concurrency_feedback_debug (no)\fR"
233 /* Make the queue manager's feedback algorithm verbose for performance
234 /* analysis purposes.
235 /* RECIPIENT SCHEDULING CONTROLS
236 /* .ad
237 /* .fi
238 /* .IP "\fBdefault_destination_recipient_limit (50)\fR"
239 /* The default maximal number of recipients per message delivery.
240 /* .IP "\fBtransport_destination_recipient_limit ($default_destination_recipient_limit)\fR"
241 /* A transport-specific override for the
242 /* default_destination_recipient_limit parameter value, where
243 /* \fItransport\fR is the master.cf name of the message delivery
244 /* transport.
245 /* OTHER RESOURCE AND RATE CONTROLS
246 /* .ad
247 /* .fi
248 /* .IP "\fBminimal_backoff_time (300s)\fR"
249 /* The minimal time between attempts to deliver a deferred message;
250 /* prior to Postfix 2.4 the default value was 1000s.
251 /* .IP "\fBmaximal_backoff_time (4000s)\fR"
252 /* The maximal time between attempts to deliver a deferred message.
253 /* .IP "\fBmaximal_queue_lifetime (5d)\fR"
254 /* Consider a message as undeliverable, when delivery fails with a
255 /* temporary error, and the time in the queue has reached the
256 /* maximal_queue_lifetime limit.
257 /* .IP "\fBqueue_run_delay (300s)\fR"
258 /* The time between deferred queue scans by the queue manager;
259 /* prior to Postfix 2.4 the default value was 1000s.
260 /* .IP "\fBtransport_retry_time (60s)\fR"
261 /* The time between attempts by the Postfix queue manager to contact
262 /* a malfunctioning message delivery transport.
263 /* .PP
264 /* Available in Postfix version 2.1 and later:
265 /* .IP "\fBbounce_queue_lifetime (5d)\fR"
266 /* Consider a bounce message as undeliverable, when delivery fails
267 /* with a temporary error, and the time in the queue has reached the
268 /* bounce_queue_lifetime limit.
269 /* .PP
270 /* Available in Postfix version 2.5 and later:
271 /* .IP "\fBdefault_destination_rate_delay (0s)\fR"
272 /* The default amount of delay that is inserted between individual
273 /* message deliveries to the same destination and over the same message
274 /* delivery transport.
275 /* .IP "\fBtransport_destination_rate_delay ($default_destination_rate_delay)\fR"
276 /* A transport-specific override for the default_destination_rate_delay
277 /* parameter value, where \fItransport\fR is the master.cf name of
278 /* the message delivery transport.
279 /* .PP
280 /* Available in Postfix version 3.1 and later:
281 /* .IP "\fBdefault_transport_rate_delay (0s)\fR"
282 /* The default amount of delay that is inserted between individual
283 /* message deliveries over the same message delivery transport,
284 /* regardless of destination.
285 /* .IP "\fBtransport_transport_rate_delay ($default_transport_rate_delay)\fR"
286 /* A transport-specific override for the default_transport_rate_delay
287 /* parameter value, where the initial \fItransport\fR in the parameter
288 /* name is the master.cf name of the message delivery transport.
289 /* SAFETY CONTROLS
290 /* .ad
291 /* .fi
292 /* .IP "\fBqmgr_daemon_timeout (1000s)\fR"
293 /* How much time a Postfix queue manager process may take to handle
294 /* a request before it is terminated by a built-in watchdog timer.
295 /* .IP "\fBqmgr_ipc_timeout (60s)\fR"
296 /* The time limit for the queue manager to send or receive information
297 /* over an internal communication channel.
298 /* .PP
299 /* Available in Postfix version 3.1 and later:
300 /* .IP "\fBaddress_verify_pending_request_limit (see 'postconf -d' output)\fR"
301 /* A safety limit that prevents address verification requests from
302 /* overwhelming the Postfix queue.
303 /* MISCELLANEOUS CONTROLS
304 /* .ad
305 /* .fi
306 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
307 /* The default location of the Postfix main.cf and master.cf
308 /* configuration files.
309 /* .IP "\fBdefer_transports (empty)\fR"
310 /* The names of message delivery transports that should not deliver mail
311 /* unless someone issues "\fBsendmail -q\fR" or equivalent.
312 /* .IP "\fBdelay_logging_resolution_limit (2)\fR"
313 /* The maximal number of digits after the decimal point when logging
314 /* sub-second delay values.
315 /* .IP "\fBhelpful_warnings (yes)\fR"
316 /* Log warnings about problematic configuration settings, and provide
317 /* helpful suggestions.
318 /* .IP "\fBprocess_id (read-only)\fR"
319 /* The process ID of a Postfix command or daemon process.
320 /* .IP "\fBprocess_name (read-only)\fR"
321 /* The process name of a Postfix command or daemon process.
322 /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR"
323 /* The location of the Postfix top-level queue directory.
324 /* .IP "\fBsyslog_facility (mail)\fR"
325 /* The syslog facility of Postfix logging.
326 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
327 /* A prefix that is prepended to the process name in syslog
328 /* records, so that, for example, "smtpd" becomes "prefix/smtpd".
329 /* .PP
330 /* Available in Postfix version 3.0 and later:
331 /* .IP "\fBconfirm_delay_cleared (no)\fR"
332 /* After sending a "your message is delayed" notification, inform
333 /* the sender when the delay clears up.
334 /* .PP
335 /* Available in Postfix 3.3 and later:
336 /* .IP "\fBservice_name (read-only)\fR"
337 /* The master.cf service name of a Postfix daemon process.
338 /* .PP
339 /* Available in Postfix 3.5 and later:
340 /* .IP "\fBinfo_log_address_format (external)\fR"
341 /* The email address form that will be used in non-debug logging
342 /* (info, warning, etc.).
343 /* FILES
344 /* /var/spool/postfix/incoming, incoming queue
345 /* /var/spool/postfix/active, active queue
346 /* /var/spool/postfix/deferred, deferred queue
347 /* /var/spool/postfix/bounce, non-delivery status
348 /* /var/spool/postfix/defer, non-delivery status
349 /* /var/spool/postfix/trace, delivery status
350 /* SEE ALSO
351 /* trivial-rewrite(8), address routing
352 /* bounce(8), delivery status reports
353 /* postconf(5), configuration parameters
354 /* master(5), generic daemon options
355 /* master(8), process manager
356 /* postlogd(8), Postfix logging
357 /* syslogd(8), system logging
358 /* README FILES
359 /* .ad
360 /* .fi
361 /* Use "\fBpostconf readme_directory\fR" or
362 /* "\fBpostconf html_directory\fR" to locate this information.
363 /* .na
364 /* .nf
365 /* QSHAPE_README, Postfix queue analysis
366 /* LICENSE
367 /* .ad
368 /* .fi
369 /* The Secure Mailer license must be distributed with this software.
370 /* AUTHOR(S)
371 /* Wietse Venema
372 /* IBM T.J. Watson Research
373 /* P.O. Box 704
374 /* Yorktown Heights, NY 10598, USA
375 /*
376 /* Wietse Venema
377 /* Google, Inc.
378 /* 111 8th Avenue
379 /* New York, NY 10011, USA
380 /*--*/
381
382 /* System library. */
383
384 #include <sys_defs.h>
385 #include <stdlib.h>
386 #include <unistd.h>
387 #include <ctype.h>
388
389 /* Utility library. */
390
391 #include <msg.h>
392 #include <events.h>
393 #include <vstream.h>
394 #include <dict.h>
395
396 /* Global library. */
397
398 #include <mail_queue.h>
399 #include <recipient_list.h>
400 #include <mail_conf.h>
401 #include <mail_params.h>
402 #include <mail_version.h>
403 #include <mail_proto.h> /* QMGR_SCAN constants */
404 #include <mail_flow.h>
405 #include <flush_clnt.h>
406
407 /* Master process interface */
408
409 #include <master_proto.h>
410 #include <mail_server.h>
411
412 /* Application-specific. */
413
414 #include "qmgr.h"
415
416 /*
417 * Tunables.
418 */
419 int var_queue_run_delay;
420 int var_min_backoff_time;
421 int var_max_backoff_time;
422 int var_max_queue_time;
423 int var_dsn_queue_time;
424 int var_qmgr_active_limit;
425 int var_qmgr_rcpt_limit;
426 int var_init_dest_concurrency;
427 int var_transport_retry_time;
428 int var_dest_con_limit;
429 int var_dest_rcpt_limit;
430 char *var_defer_xports;
431 int var_qmgr_fudge;
432 int var_local_rcpt_lim; /* XXX */
433 int var_local_con_lim; /* XXX */
434 bool var_verp_bounce_off;
435 int var_qmgr_clog_warn_time;
436 char *var_conc_pos_feedback;
437 char *var_conc_neg_feedback;
438 int var_conc_cohort_limit;
439 int var_conc_feedback_debug;
440 int var_xport_rate_delay;
441 int var_dest_rate_delay;
442 char *var_def_filter_nexthop;
443 int var_qmgr_daemon_timeout;
444 int var_qmgr_ipc_timeout;
445 int var_dsn_delay_cleared;
446 int var_vrfy_pend_limit;
447
448 static QMGR_SCAN *qmgr_scans[2];
449
450 #define QMGR_SCAN_IDX_INCOMING 0
451 #define QMGR_SCAN_IDX_DEFERRED 1
452 #define QMGR_SCAN_IDX_COUNT (sizeof(qmgr_scans) / sizeof(qmgr_scans[0]))
453
454 /* qmgr_deferred_run_event - queue manager heartbeat */
455
qmgr_deferred_run_event(int unused_event,void * dummy)456 static void qmgr_deferred_run_event(int unused_event, void *dummy)
457 {
458
459 /*
460 * This routine runs when it is time for another deferred queue scan.
461 * Make sure this routine gets called again in the future.
462 */
463 qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_DEFERRED], QMGR_SCAN_START);
464 event_request_timer(qmgr_deferred_run_event, dummy, var_queue_run_delay);
465 }
466
467 /* qmgr_trigger_event - respond to external trigger(s) */
468
qmgr_trigger_event(char * buf,ssize_t len,char * unused_service,char ** argv)469 static void qmgr_trigger_event(char *buf, ssize_t len,
470 char *unused_service, char **argv)
471 {
472 int incoming_flag = 0;
473 int deferred_flag = 0;
474 int i;
475
476 /*
477 * Sanity check. This service takes no command-line arguments.
478 */
479 if (argv[0])
480 msg_fatal("unexpected command-line argument: %s", argv[0]);
481
482 /*
483 * Collapse identical requests that have arrived since we looked last
484 * time. There is no client feedback so there is no need to process each
485 * request in order. And as long as we don't have conflicting requests we
486 * are free to sort them into the most suitable order.
487 */
488 #define QMGR_FLUSH_BEFORE (QMGR_FLUSH_ONCE | QMGR_FLUSH_DFXP)
489
490 for (i = 0; i < len; i++) {
491 if (msg_verbose)
492 msg_info("request: %d (%c)",
493 buf[i], ISALNUM(buf[i]) ? buf[i] : '?');
494 switch (buf[i]) {
495 case TRIGGER_REQ_WAKEUP:
496 case QMGR_REQ_SCAN_INCOMING:
497 incoming_flag |= QMGR_SCAN_START;
498 break;
499 case QMGR_REQ_SCAN_DEFERRED:
500 deferred_flag |= QMGR_SCAN_START;
501 break;
502 case QMGR_REQ_FLUSH_DEAD:
503 deferred_flag |= QMGR_FLUSH_BEFORE;
504 incoming_flag |= QMGR_FLUSH_BEFORE;
505 break;
506 case QMGR_REQ_SCAN_ALL:
507 deferred_flag |= QMGR_SCAN_ALL;
508 incoming_flag |= QMGR_SCAN_ALL;
509 break;
510 default:
511 if (msg_verbose)
512 msg_info("request ignored");
513 break;
514 }
515 }
516
517 /*
518 * Process each request type at most once. Modifiers take effect upon the
519 * next queue run. If no queue run is in progress, and a queue scan is
520 * requested, the request takes effect immediately.
521 */
522 if (incoming_flag != 0)
523 qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_INCOMING], incoming_flag);
524 if (deferred_flag != 0)
525 qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_DEFERRED], deferred_flag);
526 }
527
528 /* qmgr_loop - queue manager main loop */
529
qmgr_loop(char * unused_name,char ** unused_argv)530 static int qmgr_loop(char *unused_name, char **unused_argv)
531 {
532 char *path;
533 ssize_t token_count;
534 int feed = 0;
535 int scan_idx; /* Priority order scan index */
536 static int first_scan_idx = QMGR_SCAN_IDX_INCOMING;
537 int last_scan_idx = QMGR_SCAN_IDX_COUNT - 1;
538 int delay;
539
540 /*
541 * This routine runs as part of the event handling loop, after the event
542 * manager has delivered a timer or I/O event (including the completion
543 * of a connection to a delivery process), or after it has waited for a
544 * specified amount of time. The result value of qmgr_loop() specifies
545 * how long the event manager should wait for the next event.
546 */
547 #define DONT_WAIT 0
548 #define WAIT_FOR_EVENT (-1)
549
550 /*
551 * Attempt to drain the active queue by allocating a suitable delivery
552 * process and by delivering mail via it. Delivery process allocation and
553 * mail delivery are asynchronous.
554 */
555 qmgr_active_drain();
556
557 /*
558 * Let some new blood into the active queue when the queue size is
559 * smaller than some configurable limit, and when the number of in-core
560 * recipients does not exceed some configurable limit.
561 *
562 * We import one message per interrupt, to optimally tune the input count
563 * for the number of delivery agent protocol wait states, as explained in
564 * qmgr_transport.c.
565 */
566 delay = WAIT_FOR_EVENT;
567 for (scan_idx = 0; qmgr_message_count < var_qmgr_active_limit
568 && qmgr_recipient_count < var_qmgr_rcpt_limit
569 && scan_idx < QMGR_SCAN_IDX_COUNT; ++scan_idx) {
570 last_scan_idx = (scan_idx + first_scan_idx) % QMGR_SCAN_IDX_COUNT;
571 if ((path = qmgr_scan_next(qmgr_scans[last_scan_idx])) != 0) {
572 delay = DONT_WAIT;
573 if ((feed = qmgr_active_feed(qmgr_scans[last_scan_idx], path)) != 0)
574 break;
575 }
576 }
577
578 /*
579 * Round-robin the queue scans. When the active queue becomes full,
580 * prefer new mail over deferred mail.
581 */
582 if (qmgr_message_count < var_qmgr_active_limit
583 && qmgr_recipient_count < var_qmgr_rcpt_limit) {
584 first_scan_idx = (last_scan_idx + 1) % QMGR_SCAN_IDX_COUNT;
585 } else if (first_scan_idx != QMGR_SCAN_IDX_INCOMING) {
586 first_scan_idx = QMGR_SCAN_IDX_INCOMING;
587 }
588
589 /*
590 * Global flow control. If enabled, slow down receiving processes that
591 * get ahead of the queue manager, but don't block them completely.
592 */
593 if (var_in_flow_delay > 0) {
594 token_count = mail_flow_count();
595 if (token_count < var_proc_limit) {
596 if (feed != 0 && last_scan_idx == QMGR_SCAN_IDX_INCOMING)
597 mail_flow_put(1);
598 else if (qmgr_scans[QMGR_SCAN_IDX_INCOMING]->handle == 0)
599 mail_flow_put(var_proc_limit - token_count);
600 } else if (token_count > var_proc_limit) {
601 mail_flow_get(token_count - var_proc_limit);
602 }
603 }
604 return (delay);
605 }
606
607 /* pre_accept - see if tables have changed */
608
pre_accept(char * unused_name,char ** unused_argv)609 static void pre_accept(char *unused_name, char **unused_argv)
610 {
611 const char *table;
612
613 if ((table = dict_changed_name()) != 0) {
614 msg_info("table %s has changed -- restarting", table);
615 exit(0);
616 }
617 }
618
619 /* qmgr_pre_init - pre-jail initialization */
620
qmgr_pre_init(char * unused_name,char ** unused_argv)621 static void qmgr_pre_init(char *unused_name, char **unused_argv)
622 {
623 flush_init();
624 }
625
626 /* qmgr_post_init - post-jail initialization */
627
qmgr_post_init(char * unused_name,char ** unused_argv)628 static void qmgr_post_init(char *unused_name, char **unused_argv)
629 {
630
631 /*
632 * Sanity check.
633 */
634 if (var_qmgr_rcpt_limit < var_qmgr_active_limit) {
635 msg_warn("%s is smaller than %s - adjusting %s",
636 VAR_QMGR_RCPT_LIMIT, VAR_QMGR_ACT_LIMIT, VAR_QMGR_RCPT_LIMIT);
637 var_qmgr_rcpt_limit = var_qmgr_active_limit;
638 }
639 if (var_dsn_queue_time > var_max_queue_time) {
640 msg_warn("%s is larger than %s - adjusting %s",
641 VAR_DSN_QUEUE_TIME, VAR_MAX_QUEUE_TIME, VAR_DSN_QUEUE_TIME);
642 var_dsn_queue_time = var_max_queue_time;
643 }
644
645 /*
646 * This routine runs after the skeleton code has entered the chroot jail.
647 * Prevent automatic process suicide after a limited number of client
648 * requests or after a limited amount of idle time. Move any left-over
649 * entries from the active queue to the incoming queue, and give them a
650 * time stamp into the future, in order to allow ongoing deliveries to
651 * finish first. Start scanning the incoming and deferred queues.
652 * Left-over active queue entries are moved to the incoming queue because
653 * the incoming queue has priority; moving left-overs to the deferred
654 * queue could cause anomalous delays when "postfix reload/start" are
655 * issued often. Override the IPC timeout (default 3600s) so that the
656 * queue manager can reset a broken IPC channel before the watchdog timer
657 * goes off.
658 */
659 var_ipc_timeout = var_qmgr_ipc_timeout;
660 var_use_limit = 0;
661 var_idle_limit = 0;
662 qmgr_move(MAIL_QUEUE_ACTIVE, MAIL_QUEUE_INCOMING, event_time());
663 qmgr_scans[QMGR_SCAN_IDX_INCOMING] = qmgr_scan_create(MAIL_QUEUE_INCOMING);
664 qmgr_scans[QMGR_SCAN_IDX_DEFERRED] = qmgr_scan_create(MAIL_QUEUE_DEFERRED);
665 qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_INCOMING], QMGR_SCAN_START);
666 qmgr_deferred_run_event(0, (void *) 0);
667 }
668
669 MAIL_VERSION_STAMP_DECLARE;
670
671 /* main - the main program */
672
main(int argc,char ** argv)673 int main(int argc, char **argv)
674 {
675 static const CONFIG_STR_TABLE str_table[] = {
676 VAR_DEFER_XPORTS, DEF_DEFER_XPORTS, &var_defer_xports, 0, 0,
677 VAR_CONC_POS_FDBACK, DEF_CONC_POS_FDBACK, &var_conc_pos_feedback, 1, 0,
678 VAR_CONC_NEG_FDBACK, DEF_CONC_NEG_FDBACK, &var_conc_neg_feedback, 1, 0,
679 VAR_DEF_FILTER_NEXTHOP, DEF_DEF_FILTER_NEXTHOP, &var_def_filter_nexthop, 0, 0,
680 0,
681 };
682 static const CONFIG_TIME_TABLE time_table[] = {
683 VAR_QUEUE_RUN_DELAY, DEF_QUEUE_RUN_DELAY, &var_queue_run_delay, 1, 0,
684 VAR_MIN_BACKOFF_TIME, DEF_MIN_BACKOFF_TIME, &var_min_backoff_time, 1, 0,
685 VAR_MAX_BACKOFF_TIME, DEF_MAX_BACKOFF_TIME, &var_max_backoff_time, 1, 0,
686 VAR_MAX_QUEUE_TIME, DEF_MAX_QUEUE_TIME, &var_max_queue_time, 0, 8640000,
687 VAR_DSN_QUEUE_TIME, DEF_DSN_QUEUE_TIME, &var_dsn_queue_time, 0, 8640000,
688 VAR_XPORT_RETRY_TIME, DEF_XPORT_RETRY_TIME, &var_transport_retry_time, 1, 0,
689 VAR_QMGR_CLOG_WARN_TIME, DEF_QMGR_CLOG_WARN_TIME, &var_qmgr_clog_warn_time, 0, 0,
690 VAR_XPORT_RATE_DELAY, DEF_XPORT_RATE_DELAY, &var_xport_rate_delay, 0, 0,
691 VAR_DEST_RATE_DELAY, DEF_DEST_RATE_DELAY, &var_dest_rate_delay, 0, 0,
692 VAR_QMGR_DAEMON_TIMEOUT, DEF_QMGR_DAEMON_TIMEOUT, &var_qmgr_daemon_timeout, 1, 0,
693 VAR_QMGR_IPC_TIMEOUT, DEF_QMGR_IPC_TIMEOUT, &var_qmgr_ipc_timeout, 1, 0,
694 0,
695 };
696 static const CONFIG_INT_TABLE int_table[] = {
697 VAR_QMGR_ACT_LIMIT, DEF_QMGR_ACT_LIMIT, &var_qmgr_active_limit, 1, 0,
698 VAR_QMGR_RCPT_LIMIT, DEF_QMGR_RCPT_LIMIT, &var_qmgr_rcpt_limit, 1, 0,
699 VAR_INIT_DEST_CON, DEF_INIT_DEST_CON, &var_init_dest_concurrency, 1, 0,
700 VAR_DEST_CON_LIMIT, DEF_DEST_CON_LIMIT, &var_dest_con_limit, 0, 0,
701 VAR_DEST_RCPT_LIMIT, DEF_DEST_RCPT_LIMIT, &var_dest_rcpt_limit, 0, 0,
702 VAR_QMGR_FUDGE, DEF_QMGR_FUDGE, &var_qmgr_fudge, 10, 100,
703 VAR_LOCAL_RCPT_LIMIT, DEF_LOCAL_RCPT_LIMIT, &var_local_rcpt_lim, 0, 0,
704 VAR_LOCAL_CON_LIMIT, DEF_LOCAL_CON_LIMIT, &var_local_con_lim, 0, 0,
705 VAR_CONC_COHORT_LIM, DEF_CONC_COHORT_LIM, &var_conc_cohort_limit, 0, 0,
706 VAR_VRFY_PEND_LIMIT, DEF_VRFY_PEND_LIMIT, &var_vrfy_pend_limit, 1, 0,
707 0,
708 };
709 static const CONFIG_BOOL_TABLE bool_table[] = {
710 VAR_VERP_BOUNCE_OFF, DEF_VERP_BOUNCE_OFF, &var_verp_bounce_off,
711 VAR_CONC_FDBACK_DEBUG, DEF_CONC_FDBACK_DEBUG, &var_conc_feedback_debug,
712 VAR_DSN_DELAY_CLEARED, DEF_DSN_DELAY_CLEARED, &var_dsn_delay_cleared,
713 0,
714 };
715
716 /*
717 * Fingerprint executables and core dumps.
718 */
719 MAIL_VERSION_STAMP_ALLOCATE;
720
721 /*
722 * Use the trigger service skeleton, because no-one else should be
723 * monitoring our service port while this process runs, and because we do
724 * not talk back to the client.
725 */
726 trigger_server_main(argc, argv, qmgr_trigger_event,
727 CA_MAIL_SERVER_INT_TABLE(int_table),
728 CA_MAIL_SERVER_STR_TABLE(str_table),
729 CA_MAIL_SERVER_BOOL_TABLE(bool_table),
730 CA_MAIL_SERVER_TIME_TABLE(time_table),
731 CA_MAIL_SERVER_PRE_INIT(qmgr_pre_init),
732 CA_MAIL_SERVER_POST_INIT(qmgr_post_init),
733 CA_MAIL_SERVER_LOOP(qmgr_loop),
734 CA_MAIL_SERVER_PRE_ACCEPT(pre_accept),
735 CA_MAIL_SERVER_SOLITARY,
736 CA_MAIL_SERVER_WATCHDOG(&var_qmgr_daemon_timeout),
737 0);
738 }
739