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Diffstat (limited to '')
| -rw-r--r-- | src/qmgr/qmgr.c | 822 |
1 files changed, 822 insertions, 0 deletions
diff --git a/src/qmgr/qmgr.c b/src/qmgr/qmgr.c new file mode 100644 index 0000000..a48043e --- /dev/null +++ b/src/qmgr/qmgr.c @@ -0,0 +1,822 @@ +/*++ +/* NAME +/* qmgr 8 +/* SUMMARY +/* Postfix queue manager +/* SYNOPSIS +/* \fBqmgr\fR [generic Postfix daemon options] +/* DESCRIPTION +/* The \fBqmgr\fR(8) daemon awaits the arrival of incoming mail +/* and arranges for its delivery via Postfix delivery processes. +/* The actual mail routing strategy is delegated to the +/* \fBtrivial-rewrite\fR(8) daemon. +/* This program expects to be run from the \fBmaster\fR(8) process +/* manager. +/* +/* Mail addressed to the local \fBdouble-bounce\fR address is +/* logged and discarded. This stops potential loops caused by +/* undeliverable bounce notifications. +/* MAIL QUEUES +/* .ad +/* .fi +/* The \fBqmgr\fR(8) daemon maintains the following queues: +/* .IP \fBincoming\fR +/* Inbound mail from the network, or mail picked up by the +/* local \fBpickup\fR(8) daemon from the \fBmaildrop\fR directory. +/* .IP \fBactive\fR +/* Messages that the queue manager has opened for delivery. Only +/* a limited number of messages is allowed to enter the \fBactive\fR +/* queue (leaky bucket strategy, for a fixed delivery rate). +/* .IP \fBdeferred\fR +/* Mail that could not be delivered upon the first attempt. The queue +/* manager implements exponential backoff by doubling the time between +/* delivery attempts. +/* .IP \fBcorrupt\fR +/* Unreadable or damaged queue files are moved here for inspection. +/* .IP \fBhold\fR +/* Messages that are kept "on hold" are kept here until someone +/* sets them free. +/* DELIVERY STATUS REPORTS +/* .ad +/* .fi +/* The \fBqmgr\fR(8) daemon keeps an eye on per-message delivery status +/* reports in the following directories. Each status report file has +/* the same name as the corresponding message file: +/* .IP \fBbounce\fR +/* Per-recipient status information about why mail is bounced. +/* These files are maintained by the \fBbounce\fR(8) daemon. +/* .IP \fBdefer\fR +/* Per-recipient status information about why mail is delayed. +/* These files are maintained by the \fBdefer\fR(8) daemon. +/* .IP \fBtrace\fR +/* Per-recipient status information as requested with the +/* Postfix "\fBsendmail -v\fR" or "\fBsendmail -bv\fR" command. +/* These files are maintained by the \fBtrace\fR(8) daemon. +/* .PP +/* The \fBqmgr\fR(8) daemon is responsible for asking the +/* \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemons to +/* send delivery reports. +/* STRATEGIES +/* .ad +/* .fi +/* The queue manager implements a variety of strategies for +/* either opening queue files (input) or for message delivery (output). +/* .IP "\fBleaky bucket\fR" +/* This strategy limits the number of messages in the \fBactive\fR queue +/* and prevents the queue manager from running out of memory under +/* heavy load. +/* .IP \fBfairness\fR +/* When the \fBactive\fR queue has room, the queue manager takes one +/* message from the \fBincoming\fR queue and one from the \fBdeferred\fR +/* queue. This prevents a large mail backlog from blocking the delivery +/* of new mail. +/* .IP "\fBslow start\fR" +/* This strategy eliminates "thundering herd" problems by slowly +/* adjusting the number of parallel deliveries to the same destination. +/* .IP "\fBround robin\fR" +/* The queue manager sorts delivery requests by destination. +/* Round-robin selection prevents one destination from dominating +/* deliveries to other destinations. +/* .IP "\fBexponential backoff\fR" +/* Mail that cannot be delivered upon the first attempt is deferred. +/* The time interval between delivery attempts is doubled after each +/* attempt. +/* .IP "\fBdestination status cache\fR" +/* The queue manager avoids unnecessary delivery attempts by +/* maintaining a short-term, in-memory list of unreachable destinations. +/* .IP "\fBpreemptive message scheduling\fR" +/* The queue manager attempts to minimize the average per-recipient delay +/* while still preserving the correct per-message delays, using +/* a sophisticated preemptive message scheduling. +/* TRIGGERS +/* .ad +/* .fi +/* On an idle system, the queue manager waits for the arrival of +/* trigger events, or it waits for a timer to go off. A trigger +/* is a one-byte message. +/* Depending on the message received, the queue manager performs +/* one of the following actions (the message is followed by the +/* symbolic constant used internally by the software): +/* .IP "\fBD (QMGR_REQ_SCAN_DEFERRED)\fR" +/* Start a deferred queue scan. If a deferred queue scan is already +/* in progress, that scan will be restarted as soon as it finishes. +/* .IP "\fBI (QMGR_REQ_SCAN_INCOMING)\fR" +/* Start an incoming queue scan. If an incoming queue scan is already +/* in progress, that scan will be restarted as soon as it finishes. +/* .IP "\fBA (QMGR_REQ_SCAN_ALL)\fR" +/* Ignore deferred queue file time stamps. The request affects +/* the next deferred queue scan. +/* .IP "\fBF (QMGR_REQ_FLUSH_DEAD)\fR" +/* Purge all information about dead transports and destinations. +/* .IP "\fBW (TRIGGER_REQ_WAKEUP)\fR" +/* Wakeup call, This is used by the master server to instantiate +/* servers that should not go away forever. The action is to start +/* an incoming queue scan. +/* .PP +/* The \fBqmgr\fR(8) daemon reads an entire buffer worth of triggers. +/* Multiple identical trigger requests are collapsed into one, and +/* trigger requests are sorted so that \fBA\fR and \fBF\fR precede +/* \fBD\fR and \fBI\fR. Thus, in order to force a deferred queue run, +/* one would request \fBA F D\fR; in order to notify the queue manager +/* of the arrival of new mail one would request \fBI\fR. +/* STANDARDS +/* RFC 3463 (Enhanced status codes) +/* RFC 3464 (Delivery status notifications) +/* SECURITY +/* .ad +/* .fi +/* The \fBqmgr\fR(8) daemon is not security sensitive. It reads +/* single-character messages from untrusted local users, and thus may +/* be susceptible to denial of service attacks. The \fBqmgr\fR(8) daemon +/* does not talk to the outside world, and it can be run at fixed low +/* privilege in a chrooted environment. +/* DIAGNOSTICS +/* Problems and transactions are logged to \fBsyslogd\fR(8) +/* or \fBpostlogd\fR(8). +/* Corrupted message files are saved to the \fBcorrupt\fR queue +/* for further inspection. +/* +/* Depending on the setting of the \fBnotify_classes\fR parameter, +/* the postmaster is notified of bounces and of other trouble. +/* BUGS +/* A single queue manager process has to compete for disk access with +/* multiple front-end processes such as \fBcleanup\fR(8). A sudden burst of +/* inbound mail can negatively impact outbound delivery rates. +/* CONFIGURATION PARAMETERS +/* .ad +/* .fi +/* Changes to \fBmain.cf\fR are not picked up automatically +/* as \fBqmgr\fR(8) +/* is a persistent process. Use the "\fBpostfix reload\fR" command after +/* a configuration change. +/* +/* The text below provides only a parameter summary. See +/* \fBpostconf\fR(5) for more details including examples. +/* +/* In the text below, \fItransport\fR is the first field in a +/* \fBmaster.cf\fR entry. +/* COMPATIBILITY CONTROLS +/* .ad +/* .fi +/* Available before Postfix version 2.5: +/* .IP "\fBallow_min_user (no)\fR" +/* Allow a sender or recipient address to have `-' as the first +/* character. +/* .PP +/* Available with Postfix version 2.7 and later: +/* .IP "\fBdefault_filter_nexthop (empty)\fR" +/* When a content_filter or FILTER request specifies no explicit +/* next-hop destination, use $default_filter_nexthop instead; when +/* that value is empty, use the domain in the recipient address. +/* ACTIVE QUEUE CONTROLS +/* .ad +/* .fi +/* .IP "\fBqmgr_clog_warn_time (300s)\fR" +/* The minimal delay between warnings that a specific destination is +/* clogging up the Postfix active queue. +/* .IP "\fBqmgr_message_active_limit (20000)\fR" +/* The maximal number of messages in the active queue. +/* .IP "\fBqmgr_message_recipient_limit (20000)\fR" +/* The maximal number of recipients held in memory by the Postfix +/* queue manager, and the maximal size of the short-term, +/* in-memory "dead" destination status cache. +/* .IP "\fBqmgr_message_recipient_minimum (10)\fR" +/* The minimal number of in-memory recipients for any message. +/* .IP "\fBdefault_recipient_limit (20000)\fR" +/* The default per-transport upper limit on the number of in-memory +/* recipients. +/* .IP "\fBtransport_recipient_limit ($default_recipient_limit)\fR" +/* A transport-specific override for the default_recipient_limit +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_extra_recipient_limit (1000)\fR" +/* The default value for the extra per-transport limit imposed on the +/* number of in-memory recipients. +/* .IP "\fBtransport_extra_recipient_limit ($default_extra_recipient_limit)\fR" +/* A transport-specific override for the default_extra_recipient_limit +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .PP +/* Available in Postfix version 2.4 and later: +/* .IP "\fBdefault_recipient_refill_limit (100)\fR" +/* The default per-transport limit on the number of recipients refilled at +/* once. +/* .IP "\fBtransport_recipient_refill_limit ($default_recipient_refill_limit)\fR" +/* A transport-specific override for the default_recipient_refill_limit +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_recipient_refill_delay (5s)\fR" +/* The default per-transport maximum delay between recipients refills. +/* .IP "\fBtransport_recipient_refill_delay ($default_recipient_refill_delay)\fR" +/* A transport-specific override for the default_recipient_refill_delay +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* DELIVERY CONCURRENCY CONTROLS +/* .ad +/* .fi +/* .IP "\fBinitial_destination_concurrency (5)\fR" +/* The initial per-destination concurrency level for parallel delivery +/* to the same destination. +/* .IP "\fBdefault_destination_concurrency_limit (20)\fR" +/* The default maximal number of parallel deliveries to the same +/* destination. +/* .IP "\fBtransport_destination_concurrency_limit ($default_destination_concurrency_limit)\fR" +/* A transport-specific override for the +/* default_destination_concurrency_limit parameter value, where +/* \fItransport\fR is the master.cf name of the message delivery +/* transport. +/* .PP +/* Available in Postfix version 2.5 and later: +/* .IP "\fBtransport_initial_destination_concurrency ($initial_destination_concurrency)\fR" +/* A transport-specific override for the initial_destination_concurrency +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_destination_concurrency_failed_cohort_limit (1)\fR" +/* How many pseudo-cohorts must suffer connection or handshake +/* failure before a specific destination is considered unavailable +/* (and further delivery is suspended). +/* .IP "\fBtransport_destination_concurrency_failed_cohort_limit ($default_destination_concurrency_failed_cohort_limit)\fR" +/* A transport-specific override for the +/* default_destination_concurrency_failed_cohort_limit parameter value, +/* where \fItransport\fR is the master.cf name of the message delivery +/* transport. +/* .IP "\fBdefault_destination_concurrency_negative_feedback (1)\fR" +/* The per-destination amount of delivery concurrency negative +/* feedback, after a delivery completes with a connection or handshake +/* failure. +/* .IP "\fBtransport_destination_concurrency_negative_feedback ($default_destination_concurrency_negative_feedback)\fR" +/* A transport-specific override for the +/* default_destination_concurrency_negative_feedback parameter value, +/* where \fItransport\fR is the master.cf name of the message delivery +/* transport. +/* .IP "\fBdefault_destination_concurrency_positive_feedback (1)\fR" +/* The per-destination amount of delivery concurrency positive +/* feedback, after a delivery completes without connection or handshake +/* failure. +/* .IP "\fBtransport_destination_concurrency_positive_feedback ($default_destination_concurrency_positive_feedback)\fR" +/* A transport-specific override for the +/* default_destination_concurrency_positive_feedback parameter value, +/* where \fItransport\fR is the master.cf name of the message delivery +/* transport. +/* .IP "\fBdestination_concurrency_feedback_debug (no)\fR" +/* Make the queue manager's feedback algorithm verbose for performance +/* analysis purposes. +/* RECIPIENT SCHEDULING CONTROLS +/* .ad +/* .fi +/* .IP "\fBdefault_destination_recipient_limit (50)\fR" +/* The default maximal number of recipients per message delivery. +/* .IP "\fBtransport_destination_recipient_limit ($default_destination_recipient_limit)\fR" +/* A transport-specific override for the +/* default_destination_recipient_limit parameter value, where +/* \fItransport\fR is the master.cf name of the message delivery +/* transport. +/* MESSAGE SCHEDULING CONTROLS +/* .ad +/* .fi +/* .IP "\fBdefault_delivery_slot_cost (5)\fR" +/* How often the Postfix queue manager's scheduler is allowed to +/* preempt delivery of one message with another. +/* .IP "\fBtransport_delivery_slot_cost ($default_delivery_slot_cost)\fR" +/* A transport-specific override for the default_delivery_slot_cost +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_minimum_delivery_slots (3)\fR" +/* How many recipients a message must have in order to invoke the +/* Postfix queue manager's scheduling algorithm at all. +/* .IP "\fBtransport_minimum_delivery_slots ($default_minimum_delivery_slots)\fR" +/* A transport-specific override for the default_minimum_delivery_slots +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_delivery_slot_discount (50)\fR" +/* The default value for transport-specific _delivery_slot_discount +/* settings. +/* .IP "\fBtransport_delivery_slot_discount ($default_delivery_slot_discount)\fR" +/* A transport-specific override for the default_delivery_slot_discount +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .IP "\fBdefault_delivery_slot_loan (3)\fR" +/* The default value for transport-specific _delivery_slot_loan +/* settings. +/* .IP "\fBtransport_delivery_slot_loan ($default_delivery_slot_loan)\fR" +/* A transport-specific override for the default_delivery_slot_loan +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* OTHER RESOURCE AND RATE CONTROLS +/* .ad +/* .fi +/* .IP "\fBminimal_backoff_time (300s)\fR" +/* The minimal time between attempts to deliver a deferred message; +/* prior to Postfix 2.4 the default value was 1000s. +/* .IP "\fBmaximal_backoff_time (4000s)\fR" +/* The maximal time between attempts to deliver a deferred message. +/* .IP "\fBmaximal_queue_lifetime (5d)\fR" +/* Consider a message as undeliverable, when delivery fails with a +/* temporary error, and the time in the queue has reached the +/* maximal_queue_lifetime limit. +/* .IP "\fBqueue_run_delay (300s)\fR" +/* The time between deferred queue scans by the queue manager; +/* prior to Postfix 2.4 the default value was 1000s. +/* .IP "\fBtransport_retry_time (60s)\fR" +/* The time between attempts by the Postfix queue manager to contact +/* a malfunctioning message delivery transport. +/* .PP +/* Available in Postfix version 2.1 and later: +/* .IP "\fBbounce_queue_lifetime (5d)\fR" +/* Consider a bounce message as undeliverable, when delivery fails +/* with a temporary error, and the time in the queue has reached the +/* bounce_queue_lifetime limit. +/* .PP +/* Available in Postfix version 2.5 and later: +/* .IP "\fBdefault_destination_rate_delay (0s)\fR" +/* The default amount of delay that is inserted between individual +/* message deliveries to the same destination and over the same message +/* delivery transport. +/* .IP "\fBtransport_destination_rate_delay ($default_destination_rate_delay)\fR" +/* A transport-specific override for the default_destination_rate_delay +/* parameter value, where \fItransport\fR is the master.cf name of +/* the message delivery transport. +/* .PP +/* Available in Postfix version 3.1 and later: +/* .IP "\fBdefault_transport_rate_delay (0s)\fR" +/* The default amount of delay that is inserted between individual +/* message deliveries over the same message delivery transport, +/* regardless of destination. +/* .IP "\fBtransport_transport_rate_delay ($default_transport_rate_delay)\fR" +/* A transport-specific override for the default_transport_rate_delay +/* parameter value, where the initial \fItransport\fR in the parameter +/* name is the master.cf name of the message delivery transport. +/* SAFETY CONTROLS +/* .ad +/* .fi +/* .IP "\fBqmgr_daemon_timeout (1000s)\fR" +/* How much time a Postfix queue manager process may take to handle +/* a request before it is terminated by a built-in watchdog timer. +/* .IP "\fBqmgr_ipc_timeout (60s)\fR" +/* The time limit for the queue manager to send or receive information +/* over an internal communication channel. +/* .PP +/* Available in Postfix version 3.1 and later: +/* .IP "\fBaddress_verify_pending_request_limit (see 'postconf -d' output)\fR" +/* A safety limit that prevents address verification requests from +/* overwhelming the Postfix queue. +/* MISCELLANEOUS CONTROLS +/* .ad +/* .fi +/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +/* The default location of the Postfix main.cf and master.cf +/* configuration files. +/* .IP "\fBdefer_transports (empty)\fR" +/* The names of message delivery transports that should not deliver mail +/* unless someone issues "\fBsendmail -q\fR" or equivalent. +/* .IP "\fBdelay_logging_resolution_limit (2)\fR" +/* The maximal number of digits after the decimal point when logging +/* sub-second delay values. +/* .IP "\fBhelpful_warnings (yes)\fR" +/* Log warnings about problematic configuration settings, and provide +/* helpful suggestions. +/* .IP "\fBprocess_id (read-only)\fR" +/* The process ID of a Postfix command or daemon process. +/* .IP "\fBprocess_name (read-only)\fR" +/* The process name of a Postfix command or daemon process. +/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" +/* The location of the Postfix top-level queue directory. +/* .IP "\fBsyslog_facility (mail)\fR" +/* The syslog facility of Postfix logging. +/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" +/* A prefix that is prepended to the process name in syslog +/* records, so that, for example, "smtpd" becomes "prefix/smtpd". +/* .PP +/* Available in Postfix version 3.0 and later: +/* .IP "\fBconfirm_delay_cleared (no)\fR" +/* After sending a "your message is delayed" notification, inform +/* the sender when the delay clears up. +/* .PP +/* Available in Postfix 3.3 and later: +/* .IP "\fBservice_name (read-only)\fR" +/* The master.cf service name of a Postfix daemon process. +/* FILES +/* /var/spool/postfix/incoming, incoming queue +/* /var/spool/postfix/active, active queue +/* /var/spool/postfix/deferred, deferred queue +/* /var/spool/postfix/bounce, non-delivery status +/* /var/spool/postfix/defer, non-delivery status +/* /var/spool/postfix/trace, delivery status +/* SEE ALSO +/* trivial-rewrite(8), address routing +/* bounce(8), delivery status reports +/* postconf(5), configuration parameters +/* master(5), generic daemon options +/* master(8), process manager +/* postlogd(8), Postfix logging +/* syslogd(8), system logging +/* README FILES +/* .ad +/* .fi +/* Use "\fBpostconf readme_directory\fR" or +/* "\fBpostconf html_directory\fR" to locate this information. +/* .na +/* .nf +/* SCHEDULER_README, scheduling algorithm +/* QSHAPE_README, Postfix queue analysis +/* LICENSE +/* .ad +/* .fi +/* The Secure Mailer license must be distributed with this software. +/* AUTHOR(S) +/* Wietse Venema +/* IBM T.J. Watson Research +/* P.O. Box 704 +/* Yorktown Heights, NY 10598, USA +/* +/* Preemptive scheduler enhancements: +/* Patrik Rak +/* Modra 6 +/* 155 00, Prague, Czech Republic +/* +/* Wietse Venema +/* Google, Inc. +/* 111 8th Avenue +/* New York, NY 10011, USA +/*--*/ + +/* System library. */ + +#include <sys_defs.h> +#include <stdlib.h> +#include <unistd.h> +#include <ctype.h> + +/* Utility library. */ + +#include <msg.h> +#include <events.h> +#include <vstream.h> +#include <dict.h> + +/* Global library. */ + +#include <mail_queue.h> +#include <recipient_list.h> +#include <mail_conf.h> +#include <mail_params.h> +#include <mail_version.h> +#include <mail_proto.h> /* QMGR_SCAN constants */ +#include <mail_flow.h> +#include <flush_clnt.h> + +/* Master process interface */ + +#include <master_proto.h> +#include <mail_server.h> + +/* Application-specific. */ + +#include "qmgr.h" + + /* + * Tunables. + */ +int var_queue_run_delay; +int var_min_backoff_time; +int var_max_backoff_time; +int var_max_queue_time; +int var_dsn_queue_time; +int var_qmgr_active_limit; +int var_qmgr_rcpt_limit; +int var_qmgr_msg_rcpt_limit; +int var_xport_rcpt_limit; +int var_stack_rcpt_limit; +int var_xport_refill_limit; +int var_xport_refill_delay; +int var_delivery_slot_cost; +int var_delivery_slot_loan; +int var_delivery_slot_discount; +int var_min_delivery_slots; +int var_init_dest_concurrency; +int var_transport_retry_time; +int var_dest_con_limit; +int var_dest_rcpt_limit; +char *var_defer_xports; +int var_local_con_lim; +int var_local_rcpt_lim; +bool var_verp_bounce_off; +int var_qmgr_clog_warn_time; +char *var_conc_pos_feedback; +char *var_conc_neg_feedback; +int var_conc_cohort_limit; +int var_conc_feedback_debug; +int var_xport_rate_delay; +int var_dest_rate_delay; +char *var_def_filter_nexthop; +int var_qmgr_daemon_timeout; +int var_qmgr_ipc_timeout; +int var_dsn_delay_cleared; +int var_vrfy_pend_limit; + +static QMGR_SCAN *qmgr_scans[2]; + +#define QMGR_SCAN_IDX_INCOMING 0 +#define QMGR_SCAN_IDX_DEFERRED 1 +#define QMGR_SCAN_IDX_COUNT (sizeof(qmgr_scans) / sizeof(qmgr_scans[0])) + +/* qmgr_deferred_run_event - queue manager heartbeat */ + +static void qmgr_deferred_run_event(int unused_event, void *dummy) +{ + + /* + * This routine runs when it is time for another deferred queue scan. + * Make sure this routine gets called again in the future. + */ + qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_DEFERRED], QMGR_SCAN_START); + event_request_timer(qmgr_deferred_run_event, dummy, var_queue_run_delay); +} + +/* qmgr_trigger_event - respond to external trigger(s) */ + +static void qmgr_trigger_event(char *buf, ssize_t len, + char *unused_service, char **argv) +{ + int incoming_flag = 0; + int deferred_flag = 0; + int i; + + /* + * Sanity check. This service takes no command-line arguments. + */ + if (argv[0]) + msg_fatal("unexpected command-line argument: %s", argv[0]); + + /* + * Collapse identical requests that have arrived since we looked last + * time. There is no client feedback so there is no need to process each + * request in order. And as long as we don't have conflicting requests we + * are free to sort them into the most suitable order. + */ +#define QMGR_FLUSH_BEFORE (QMGR_FLUSH_ONCE | QMGR_FLUSH_DFXP) + + for (i = 0; i < len; i++) { + if (msg_verbose) + msg_info("request: %d (%c)", + buf[i], ISALNUM(buf[i]) ? buf[i] : '?'); + switch (buf[i]) { + case TRIGGER_REQ_WAKEUP: + case QMGR_REQ_SCAN_INCOMING: + incoming_flag |= QMGR_SCAN_START; + break; + case QMGR_REQ_SCAN_DEFERRED: + deferred_flag |= QMGR_SCAN_START; + break; + case QMGR_REQ_FLUSH_DEAD: + deferred_flag |= QMGR_FLUSH_BEFORE; + incoming_flag |= QMGR_FLUSH_BEFORE; + break; + case QMGR_REQ_SCAN_ALL: + deferred_flag |= QMGR_SCAN_ALL; + incoming_flag |= QMGR_SCAN_ALL; + break; + default: + if (msg_verbose) + msg_info("request ignored"); + break; + } + } + + /* + * Process each request type at most once. Modifiers take effect upon the + * next queue run. If no queue run is in progress, and a queue scan is + * requested, the request takes effect immediately. + */ + if (incoming_flag != 0) + qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_INCOMING], incoming_flag); + if (deferred_flag != 0) + qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_DEFERRED], deferred_flag); +} + +/* qmgr_loop - queue manager main loop */ + +static int qmgr_loop(char *unused_name, char **unused_argv) +{ + char *path; + ssize_t token_count; + int feed = 0; + int scan_idx; /* Priority order scan index */ + static int first_scan_idx = QMGR_SCAN_IDX_INCOMING; + int last_scan_idx = QMGR_SCAN_IDX_COUNT - 1; + int delay; + + /* + * This routine runs as part of the event handling loop, after the event + * manager has delivered a timer or I/O event (including the completion + * of a connection to a delivery process), or after it has waited for a + * specified amount of time. The result value of qmgr_loop() specifies + * how long the event manager should wait for the next event. + */ +#define DONT_WAIT 0 +#define WAIT_FOR_EVENT (-1) + + /* + * Attempt to drain the active queue by allocating a suitable delivery + * process and by delivering mail via it. Delivery process allocation and + * mail delivery are asynchronous. + */ + qmgr_active_drain(); + + /* + * Let some new blood into the active queue when the queue size is + * smaller than some configurable limit. + * + * We import one message per interrupt, to optimally tune the input count + * for the number of delivery agent protocol wait states, as explained in + * qmgr_transport.c. + */ + delay = WAIT_FOR_EVENT; + for (scan_idx = 0; qmgr_message_count < var_qmgr_active_limit + && scan_idx < QMGR_SCAN_IDX_COUNT; ++scan_idx) { + last_scan_idx = (scan_idx + first_scan_idx) % QMGR_SCAN_IDX_COUNT; + if ((path = qmgr_scan_next(qmgr_scans[last_scan_idx])) != 0) { + delay = DONT_WAIT; + if ((feed = qmgr_active_feed(qmgr_scans[last_scan_idx], path)) != 0) + break; + } + } + + /* + * Round-robin the queue scans. When the active queue becomes full, + * prefer new mail over deferred mail. + */ + if (qmgr_message_count < var_qmgr_active_limit) { + first_scan_idx = (last_scan_idx + 1) % QMGR_SCAN_IDX_COUNT; + } else if (first_scan_idx != QMGR_SCAN_IDX_INCOMING) { + first_scan_idx = QMGR_SCAN_IDX_INCOMING; + } + + /* + * Global flow control. If enabled, slow down receiving processes that + * get ahead of the queue manager, but don't block them completely. + */ + if (var_in_flow_delay > 0) { + token_count = mail_flow_count(); + if (token_count < var_proc_limit) { + if (feed != 0 && last_scan_idx == QMGR_SCAN_IDX_INCOMING) + mail_flow_put(1); + else if (qmgr_scans[QMGR_SCAN_IDX_INCOMING]->handle == 0) + mail_flow_put(var_proc_limit - token_count); + } else if (token_count > var_proc_limit) { + mail_flow_get(token_count - var_proc_limit); + } + } + return (delay); +} + +/* pre_accept - see if tables have changed */ + +static void pre_accept(char *unused_name, char **unused_argv) +{ + const char *table; + + if ((table = dict_changed_name()) != 0) { + msg_info("table %s has changed -- restarting", table); + exit(0); + } +} + +/* qmgr_pre_init - pre-jail initialization */ + +static void qmgr_pre_init(char *unused_name, char **unused_argv) +{ + flush_init(); +} + +/* qmgr_post_init - post-jail initialization */ + +static void qmgr_post_init(char *name, char **unused_argv) +{ + + /* + * Backwards compatibility. + */ + if (strcmp(var_procname, "nqmgr") == 0) { + msg_warn("please update the %s/%s file; the new queue manager", + var_config_dir, MASTER_CONF_FILE); + msg_warn("(old name: nqmgr) has become the standard queue manager (new name: qmgr)"); + msg_warn("support for the name old name (nqmgr) will be removed from Postfix"); + } + + /* + * Sanity check. + */ + if (var_qmgr_rcpt_limit < var_qmgr_active_limit) { + msg_warn("%s is smaller than %s - adjusting %s", + VAR_QMGR_RCPT_LIMIT, VAR_QMGR_ACT_LIMIT, VAR_QMGR_RCPT_LIMIT); + var_qmgr_rcpt_limit = var_qmgr_active_limit; + } + if (var_dsn_queue_time > var_max_queue_time) { + msg_warn("%s is larger than %s - adjusting %s", + VAR_DSN_QUEUE_TIME, VAR_MAX_QUEUE_TIME, VAR_DSN_QUEUE_TIME); + var_dsn_queue_time = var_max_queue_time; + } + + /* + * This routine runs after the skeleton code has entered the chroot jail. + * Prevent automatic process suicide after a limited number of client + * requests or after a limited amount of idle time. Move any left-over + * entries from the active queue to the incoming queue, and give them a + * time stamp into the future, in order to allow ongoing deliveries to + * finish first. Start scanning the incoming and deferred queues. + * Left-over active queue entries are moved to the incoming queue because + * the incoming queue has priority; moving left-overs to the deferred + * queue could cause anomalous delays when "postfix reload/start" are + * issued often. Override the IPC timeout (default 3600s) so that the + * queue manager can reset a broken IPC channel before the watchdog timer + * goes off. + */ + var_ipc_timeout = var_qmgr_ipc_timeout; + var_use_limit = 0; + var_idle_limit = 0; + qmgr_move(MAIL_QUEUE_ACTIVE, MAIL_QUEUE_INCOMING, event_time()); + qmgr_scans[QMGR_SCAN_IDX_INCOMING] = qmgr_scan_create(MAIL_QUEUE_INCOMING); + qmgr_scans[QMGR_SCAN_IDX_DEFERRED] = qmgr_scan_create(MAIL_QUEUE_DEFERRED); + qmgr_scan_request(qmgr_scans[QMGR_SCAN_IDX_INCOMING], QMGR_SCAN_START); + qmgr_deferred_run_event(0, (void *) 0); +} + +MAIL_VERSION_STAMP_DECLARE; + +/* main - the main program */ + +int main(int argc, char **argv) +{ + static const CONFIG_STR_TABLE str_table[] = { + VAR_DEFER_XPORTS, DEF_DEFER_XPORTS, &var_defer_xports, 0, 0, + VAR_CONC_POS_FDBACK, DEF_CONC_POS_FDBACK, &var_conc_pos_feedback, 1, 0, + VAR_CONC_NEG_FDBACK, DEF_CONC_NEG_FDBACK, &var_conc_neg_feedback, 1, 0, + VAR_DEF_FILTER_NEXTHOP, DEF_DEF_FILTER_NEXTHOP, &var_def_filter_nexthop, 0, 0, + 0, + }; + static const CONFIG_TIME_TABLE time_table[] = { + VAR_QUEUE_RUN_DELAY, DEF_QUEUE_RUN_DELAY, &var_queue_run_delay, 1, 0, + VAR_MIN_BACKOFF_TIME, DEF_MIN_BACKOFF_TIME, &var_min_backoff_time, 1, 0, + VAR_MAX_BACKOFF_TIME, DEF_MAX_BACKOFF_TIME, &var_max_backoff_time, 1, 0, + VAR_MAX_QUEUE_TIME, DEF_MAX_QUEUE_TIME, &var_max_queue_time, 0, 8640000, + VAR_DSN_QUEUE_TIME, DEF_DSN_QUEUE_TIME, &var_dsn_queue_time, 0, 8640000, + VAR_XPORT_RETRY_TIME, DEF_XPORT_RETRY_TIME, &var_transport_retry_time, 1, 0, + VAR_QMGR_CLOG_WARN_TIME, DEF_QMGR_CLOG_WARN_TIME, &var_qmgr_clog_warn_time, 0, 0, + VAR_XPORT_REFILL_DELAY, DEF_XPORT_REFILL_DELAY, &var_xport_refill_delay, 1, 0, + VAR_XPORT_RATE_DELAY, DEF_XPORT_RATE_DELAY, &var_xport_rate_delay, 0, 0, + VAR_DEST_RATE_DELAY, DEF_DEST_RATE_DELAY, &var_dest_rate_delay, 0, 0, + VAR_QMGR_DAEMON_TIMEOUT, DEF_QMGR_DAEMON_TIMEOUT, &var_qmgr_daemon_timeout, 1, 0, + VAR_QMGR_IPC_TIMEOUT, DEF_QMGR_IPC_TIMEOUT, &var_qmgr_ipc_timeout, 1, 0, + 0, + }; + static const CONFIG_INT_TABLE int_table[] = { + VAR_QMGR_ACT_LIMIT, DEF_QMGR_ACT_LIMIT, &var_qmgr_active_limit, 1, 0, + VAR_QMGR_RCPT_LIMIT, DEF_QMGR_RCPT_LIMIT, &var_qmgr_rcpt_limit, 1, 0, + VAR_QMGR_MSG_RCPT_LIMIT, DEF_QMGR_MSG_RCPT_LIMIT, &var_qmgr_msg_rcpt_limit, 1, 0, + VAR_XPORT_RCPT_LIMIT, DEF_XPORT_RCPT_LIMIT, &var_xport_rcpt_limit, 0, 0, + VAR_STACK_RCPT_LIMIT, DEF_STACK_RCPT_LIMIT, &var_stack_rcpt_limit, 0, 0, + VAR_XPORT_REFILL_LIMIT, DEF_XPORT_REFILL_LIMIT, &var_xport_refill_limit, 1, 0, + VAR_DELIVERY_SLOT_COST, DEF_DELIVERY_SLOT_COST, &var_delivery_slot_cost, 0, 0, + VAR_DELIVERY_SLOT_LOAN, DEF_DELIVERY_SLOT_LOAN, &var_delivery_slot_loan, 0, 0, + VAR_DELIVERY_SLOT_DISCOUNT, DEF_DELIVERY_SLOT_DISCOUNT, &var_delivery_slot_discount, 0, 100, + VAR_MIN_DELIVERY_SLOTS, DEF_MIN_DELIVERY_SLOTS, &var_min_delivery_slots, 0, 0, + VAR_INIT_DEST_CON, DEF_INIT_DEST_CON, &var_init_dest_concurrency, 1, 0, + VAR_DEST_CON_LIMIT, DEF_DEST_CON_LIMIT, &var_dest_con_limit, 0, 0, + VAR_DEST_RCPT_LIMIT, DEF_DEST_RCPT_LIMIT, &var_dest_rcpt_limit, 0, 0, + VAR_LOCAL_RCPT_LIMIT, DEF_LOCAL_RCPT_LIMIT, &var_local_rcpt_lim, 0, 0, + VAR_LOCAL_CON_LIMIT, DEF_LOCAL_CON_LIMIT, &var_local_con_lim, 0, 0, + VAR_CONC_COHORT_LIM, DEF_CONC_COHORT_LIM, &var_conc_cohort_limit, 0, 0, + VAR_VRFY_PEND_LIMIT, DEF_VRFY_PEND_LIMIT, &var_vrfy_pend_limit, 1, 0, + 0, + }; + static const CONFIG_BOOL_TABLE bool_table[] = { + VAR_VERP_BOUNCE_OFF, DEF_VERP_BOUNCE_OFF, &var_verp_bounce_off, + VAR_CONC_FDBACK_DEBUG, DEF_CONC_FDBACK_DEBUG, &var_conc_feedback_debug, + VAR_DSN_DELAY_CLEARED, DEF_DSN_DELAY_CLEARED, &var_dsn_delay_cleared, + 0, + }; + + /* + * Fingerprint executables and core dumps. + */ + MAIL_VERSION_STAMP_ALLOCATE; + + /* + * Use the trigger service skeleton, because no-one else should be + * monitoring our service port while this process runs, and because we do + * not talk back to the client. + */ + trigger_server_main(argc, argv, qmgr_trigger_event, + CA_MAIL_SERVER_INT_TABLE(int_table), + CA_MAIL_SERVER_STR_TABLE(str_table), + CA_MAIL_SERVER_BOOL_TABLE(bool_table), + CA_MAIL_SERVER_TIME_TABLE(time_table), + CA_MAIL_SERVER_PRE_INIT(qmgr_pre_init), + CA_MAIL_SERVER_POST_INIT(qmgr_post_init), + CA_MAIL_SERVER_LOOP(qmgr_loop), + CA_MAIL_SERVER_PRE_ACCEPT(pre_accept), + CA_MAIL_SERVER_SOLITARY, + CA_MAIL_SERVER_WATCHDOG(&var_qmgr_daemon_timeout), + 0); +} |