/* $NetBSD: qmgr_active.c,v 1.2 2017/02/14 01:16:46 christos Exp $ */
/*++
/* NAME
/* qmgr_active 3
/* SUMMARY
/* active queue management
/* SYNOPSIS
/* #include "qmgr.h"
/*
/* void qmgr_active_feed(scan_info, queue_id)
/* QMGR_SCAN *scan_info;
/* const char *queue_id;
/*
/* void qmgr_active_drain()
/*
/* int qmgr_active_done(message)
/* QMGR_MESSAGE *message;
/* DESCRIPTION
/* These functions maintain the active message queue: the set
/* of messages that the queue manager is actually working on.
/* The active queue is limited in size. Messages are drained
/* from the active queue by allocating a delivery process and
/* by delivering mail via that process. Messages leak into the
/* active queue only when the active queue is small enough.
/* Damaged message files are saved to the "corrupt" directory.
/*
/* qmgr_active_feed() inserts the named message file into
/* the active queue. Message files with the wrong name or
/* with other wrong properties are skipped but not removed.
/* The following queue flags are recognized, other flags being
/* ignored:
/* .IP QMGR_SCAN_ALL
/* Examine all queue files. Normally, deferred queue files with
/* future time stamps are ignored, and incoming queue files with
/* future time stamps are frowned upon.
/* .PP
/* qmgr_active_drain() allocates one delivery process.
/* Process allocation is asynchronous. Once the delivery
/* process is available, an attempt is made to deliver
/* a message via it. Message delivery is asynchronous, too.
/*
/* qmgr_active_done() deals with a message after delivery
/* has been tried for all in-core recipients. If the message
/* was bounced, a bounce message is sent to the sender, or
/* to the Errors-To: address if one was specified.
/* If there are more on-file recipients, a new batch of
/* in-core recipients is read from the queue file. Otherwise,
/* if a delivery agent marked the queue file as corrupt,
/* the queue file is moved to the "corrupt" queue (surprise);
/* if at least one delivery failed, the message is moved
/* to the deferred queue. The time stamps of a deferred queue
/* file are set to the nearest wakeup time of its recipient
/* sites (if delivery failed due to a problem with a next-hop
/* host), are set into the future by the amount of time the
/* message was queued (per-message exponential backoff), or are set
/* into the future by a minimal backoff time, whichever is more.
/* The minimal_backoff_time parameter specifies the minimal
/* amount of time between delivery attempts; maximal_backoff_time
/* specifies an upper limit.
/* DIAGNOSTICS
/* Fatal: queue file access failures, out of memory.
/* Panic: interface violations, internal consistency errors.
/* Warnings: corrupt message file. A corrupt message is saved
/* to the "corrupt" queue for further inspection.
/* 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
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/stat.h>
#include <dirent.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <utime.h>
#include <errno.h>
#ifndef S_IRWXU /* What? no POSIX system? */
#define S_IRWXU 0700
#endif
/* Utility library. */
#include <msg.h>
#include <events.h>
#include <mymalloc.h>
#include <vstream.h>
#include <warn_stat.h>
/* Global library. */
#include <mail_params.h>
#include <mail_open_ok.h>
#include <mail_queue.h>
#include <recipient_list.h>
#include <bounce.h>
#include <defer.h>
#include <trace.h>
#include <abounce.h>
#include <rec_type.h>
#include <qmgr_user.h>
/* Application-specific. */
#include "qmgr.h"
/*
* A bunch of call-back routines.
*/
static void qmgr_active_done_2_bounce_flush(int, void *);
static void qmgr_active_done_2_generic(QMGR_MESSAGE *);
static void qmgr_active_done_25_trace_flush(int, void *);
static void qmgr_active_done_25_generic(QMGR_MESSAGE *);
static void qmgr_active_done_3_defer_flush(int, void *);
static void qmgr_active_done_3_defer_warn(int, void *);
static void qmgr_active_done_3_generic(QMGR_MESSAGE *);
/* qmgr_active_corrupt - move corrupted file out of the way */
static void qmgr_active_corrupt(const char *queue_id)
{
const char *myname = "qmgr_active_corrupt";
if (mail_queue_rename(queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT)) {
if (errno != ENOENT)
msg_fatal("%s: save corrupt file queue %s id %s: %m",
myname, MAIL_QUEUE_ACTIVE, queue_id);
} else {
msg_warn("saving corrupt file \"%s\" from queue \"%s\" to queue \"%s\"",
queue_id, MAIL_QUEUE_ACTIVE, MAIL_QUEUE_CORRUPT);
}
}
/* qmgr_active_defer - defer queue file */
static void qmgr_active_defer(const char *queue_name, const char *queue_id,
const char *dest_queue, int delay)
{
const char *myname = "qmgr_active_defer";
const char *path;
struct utimbuf tbuf;
if (msg_verbose)
msg_info("wakeup %s after %ld secs", queue_id, (long) delay);
tbuf.actime = tbuf.modtime = event_time() + delay;
path = mail_queue_path((VSTRING *) 0, queue_name, queue_id);
if (utime(path, &tbuf) < 0 && errno != ENOENT)
msg_fatal("%s: update %s time stamps: %m", myname, path);
if (mail_queue_rename(queue_id, queue_name, dest_queue)) {
if (errno != ENOENT)
msg_fatal("%s: rename %s from %s to %s: %m", myname,
queue_id, queue_name, dest_queue);
msg_warn("%s: rename %s from %s to %s: %m", myname,
queue_id, queue_name, dest_queue);
} else if (msg_verbose) {
msg_info("%s: defer %s", myname, queue_id);
}
}
/* qmgr_active_feed - feed one message into active queue */
int qmgr_active_feed(QMGR_SCAN *scan_info, const char *queue_id)
{
const char *myname = "qmgr_active_feed";
QMGR_MESSAGE *message;
struct stat st;
const char *path;
if (strcmp(scan_info->queue, MAIL_QUEUE_ACTIVE) == 0)
msg_panic("%s: bad queue %s", myname, scan_info->queue);
if (msg_verbose)
msg_info("%s: queue %s", myname, scan_info->queue);
/*
* Make sure this is something we are willing to open.
*/
if (mail_open_ok(scan_info->queue, queue_id, &st, &path) == MAIL_OPEN_NO)
return (0);
if (msg_verbose)
msg_info("%s: %s", myname, path);
/*
* Skip files that have time stamps into the future. They need to cool
* down. Incoming and deferred files can have future time stamps.
*/
if ((scan_info->flags & QMGR_SCAN_ALL) == 0
&& st.st_mtime > time((time_t *) 0) + 1) {
if (msg_verbose)
msg_info("%s: skip %s (%ld seconds)", myname, queue_id,
(long) (st.st_mtime - event_time()));
return (0);
}
/*
* Move the message to the active queue. File access errors are fatal.
*/
if (mail_queue_rename(queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE)) {
if (errno != ENOENT)
msg_fatal("%s: %s: rename from %s to %s: %m", myname,
queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE);
msg_warn("%s: %s: rename from %s to %s: %m", myname,
queue_id, scan_info->queue, MAIL_QUEUE_ACTIVE);
return (0);
}
/*
* Extract envelope information: sender and recipients. At this point,
* mail addresses have been processed by the cleanup service so they
* should be in canonical form. Generate requests to deliver this
* message.
*
* Throwing away queue files seems bad, especially when they made it this
* far into the mail system. Therefore we save bad files to a separate
* directory for further inspection.
*
* After queue manager restart it is possible that a queue file is still
* being delivered. In that case (the file is locked), defer delivery by
* a minimal amount of time.
*/
#define QMGR_FLUSH_AFTER (QMGR_FLUSH_EACH | QMGR_FLUSH_DFXP)
if ((message = qmgr_message_alloc(MAIL_QUEUE_ACTIVE, queue_id,
(st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ?
scan_info->flags | QMGR_FLUSH_AFTER :
scan_info->flags,
(st.st_mode & MAIL_QUEUE_STAT_UNTHROTTLE) ?
st.st_mode & ~MAIL_QUEUE_STAT_UNTHROTTLE :
0)) == 0) {
qmgr_active_corrupt(queue_id);
return (0);
} else if (message == QMGR_MESSAGE_LOCKED) {
qmgr_active_defer(MAIL_QUEUE_ACTIVE, queue_id, MAIL_QUEUE_INCOMING, 60);
return (0);
} else {
/*
* Special case if all recipients were already delivered. Send any
* bounces and clean up.
*/
if (message->refcount == 0)
qmgr_active_done(message);
return (1);
}
}
/* qmgr_active_done - dispose of message after recipients have been tried */
void qmgr_active_done(QMGR_MESSAGE *message)
{
const char *myname = "qmgr_active_done";
struct stat st;
if (msg_verbose)
msg_info("%s: %s", myname, message->queue_id);
/*
* During a previous iteration, an attempt to bounce this message may
* have failed, so there may still be a bounce log lying around. XXX By
* groping around in the bounce queue, we're trespassing on the bounce
* service's territory. But doing so is more robust than depending on the
* bounce daemon to do the lookup for us, and for us to do the deleting
* after we have received a successful status from the bounce service.
* The bounce queue directory blocks are most likely in memory anyway. If
* these lookups become a performance problem we will have to build an
* in-core cache into the bounce daemon.
*
* Don't bounce when the bounce log is empty. The bounce process obviously
* failed, and the delivery agent will have requested that the message be
* deferred.
*
* Bounces are sent asynchronously to avoid stalling while the cleanup
* daemon waits for the qmgr to accept the "new mail" trigger.
*
* See also code in cleanup_bounce.c.
*/
if (stat(mail_queue_path((VSTRING *) 0, MAIL_QUEUE_BOUNCE, message->queue_id), &st) == 0) {
if (st.st_size == 0) {
if (mail_queue_remove(MAIL_QUEUE_BOUNCE, message->queue_id))
msg_fatal("remove %s %s: %m",
MAIL_QUEUE_BOUNCE, message->queue_id);
} else {
if (msg_verbose)
msg_info("%s: bounce %s", myname, message->queue_id);
if (message->verp_delims == 0 || var_verp_bounce_off)
abounce_flush(BOUNCE_FLAG_KEEP,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
qmgr_active_done_2_bounce_flush,
(void *) message);
else
abounce_flush_verp(BOUNCE_FLAG_KEEP,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
message->verp_delims,
qmgr_active_done_2_bounce_flush,
(void *) message);
return;
}
}
/*
* Asynchronous processing does not reach this point.
*/
qmgr_active_done_2_generic(message);
}
/* qmgr_active_done_2_bounce_flush - process abounce_flush() status */
static void qmgr_active_done_2_bounce_flush(int status, void *context)
{
QMGR_MESSAGE *message = (QMGR_MESSAGE *) context;
/*
* Process abounce_flush() status and continue processing.
*/
message->flags |= status;
qmgr_active_done_2_generic(message);
}
/* qmgr_active_done_2_generic - continue processing */
static void qmgr_active_done_2_generic(QMGR_MESSAGE *message)
{
const char *path;
struct stat st;
/*
* A delivery agent marks a queue file as corrupt by changing its
* attributes, and by pretending that delivery was deferred.
*/
if (message->flags
&& mail_open_ok(MAIL_QUEUE_ACTIVE, message->queue_id, &st, &path) == MAIL_OPEN_NO) {
qmgr_active_corrupt(message->queue_id);
qmgr_message_free(message);
return;
}
/*
* If we did not read all recipients from this file, go read some more,
* but remember whether some recipients have to be tried again.
*
* Throwing away queue files seems bad, especially when they made it this
* far into the mail system. Therefore we save bad files to a separate
* directory for further inspection by a human being.
*/
if (message->rcpt_offset > 0) {
if (qmgr_message_realloc(message) == 0) {
qmgr_active_corrupt(message->queue_id);
qmgr_message_free(message);
} else {
if (message->refcount == 0)
qmgr_active_done(message); /* recurse for consistency */
}
return;
}
/*
* XXX With multi-recipient mail, some recipients may have NOTIFY=SUCCESS
* and others not. Depending on what subset of recipients are delivered,
* a trace file may or may not be created. Even when the last partial
* delivery attempt had no NOTIFY=SUCCESS recipients, a trace file may
* still exist from a previous partial delivery attempt. So as long as
* any recipient has NOTIFY=SUCCESS we have to always look for the trace
* file and be prepared for the file not to exist.
*
* See also comments in bounce/bounce_notify_util.c.
*/
if ((message->tflags & (DEL_REQ_FLAG_USR_VRFY | DEL_REQ_FLAG_RECORD
| DEL_REQ_FLAG_REC_DLY_SENT))
|| (message->rflags & QMGR_READ_FLAG_NOTIFY_SUCCESS)) {
atrace_flush(message->tflags,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
qmgr_active_done_25_trace_flush,
(void *) message);
return;
}
/*
* Asynchronous processing does not reach this point.
*/
qmgr_active_done_25_generic(message);
}
/* qmgr_active_done_25_trace_flush - continue after atrace_flush() completion */
static void qmgr_active_done_25_trace_flush(int status, void *context)
{
QMGR_MESSAGE *message = (QMGR_MESSAGE *) context;
/*
* Process atrace_flush() status and continue processing.
*/
if (status == 0 && message->tflags_offset)
qmgr_message_kill_record(message, message->tflags_offset);
message->flags |= status;
qmgr_active_done_25_generic(message);
}
/* qmgr_active_done_25_generic - continue processing */
static void qmgr_active_done_25_generic(QMGR_MESSAGE *message)
{
const char *myname = "qmgr_active_done_25_generic";
/*
* If we get to this point we have tried all recipients for this message.
* If the message is too old, try to bounce it.
*
* Bounces are sent asynchronously to avoid stalling while the cleanup
* daemon waits for the qmgr to accept the "new mail" trigger.
*/
if (message->flags) {
if (event_time() >= message->create_time +
(*message->sender ? var_max_queue_time : var_dsn_queue_time)) {
msg_info("%s: from=<%s>, status=expired, returned to sender",
message->queue_id, message->sender);
if (message->verp_delims == 0 || var_verp_bounce_off)
adefer_flush(BOUNCE_FLAG_KEEP,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
qmgr_active_done_3_defer_flush,
(void *) message);
else
adefer_flush_verp(BOUNCE_FLAG_KEEP,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
message->verp_delims,
qmgr_active_done_3_defer_flush,
(void *) message);
return;
} else if (message->warn_time > 0
&& event_time() >= message->warn_time - 1) {
if (msg_verbose)
msg_info("%s: sending defer warning for %s", myname, message->queue_id);
adefer_warn(BOUNCE_FLAG_KEEP,
message->queue_name,
message->queue_id,
message->encoding,
message->smtputf8,
message->sender,
message->dsn_envid,
message->dsn_ret,
qmgr_active_done_3_defer_warn,
(void *) message);
return;
}
}
/*
* Asynchronous processing does not reach this point.
*/
qmgr_active_done_3_generic(message);
}
/* qmgr_active_done_3_defer_warn - continue after adefer_warn() completion */
static void qmgr_active_done_3_defer_warn(int status, void *context)
{
QMGR_MESSAGE *message = (QMGR_MESSAGE *) context;
/*
* Process adefer_warn() completion status and continue processing.
*/
if (status == 0)
qmgr_message_update_warn(message);
qmgr_active_done_3_generic(message);
}
/* qmgr_active_done_3_defer_flush - continue after adefer_flush() completion */
static void qmgr_active_done_3_defer_flush(int status, void *context)
{
QMGR_MESSAGE *message = (QMGR_MESSAGE *) context;
/*
* Process adefer_flush() status and continue processing.
*/
message->flags = status;
qmgr_active_done_3_generic(message);
}
/* qmgr_active_done_3_generic - continue processing */
static void qmgr_active_done_3_generic(QMGR_MESSAGE *message)
{
const char *myname = "qmgr_active_done_3_generic";
int delay;
/*
* Some recipients need to be tried again. Move the queue file time
* stamps into the future by the amount of time that the message is
* delayed, and move the message to the deferred queue. Impose minimal
* and maximal backoff times.
*
* Since we look at actual time in queue, not time since last delivery
* attempt, backoff times will be distributed. However, we can still see
* spikes in delivery activity because the interval between deferred
* queue scans is finite.
*/
if (message->flags) {
if (message->create_time > 0) {
delay = event_time() - message->create_time;
if (delay > var_max_backoff_time)
delay = var_max_backoff_time;
if (delay < var_min_backoff_time)
delay = var_min_backoff_time;
} else {
delay = var_min_backoff_time;
}
qmgr_active_defer(message->queue_name, message->queue_id,
MAIL_QUEUE_DEFERRED, delay);
}
/*
* All recipients done. Remove the queue file.
*/
else {
if (mail_queue_remove(message->queue_name, message->queue_id)) {
if (errno != ENOENT)
msg_fatal("%s: remove %s from %s: %m", myname,
message->queue_id, message->queue_name);
msg_warn("%s: remove %s from %s: %m", myname,
message->queue_id, message->queue_name);
} else {
/* Same format as logged by postsuper. */
msg_info("%s: removed", message->queue_id);
}
}
/*
* Finally, delete the in-core message structure.
*/
qmgr_message_free(message);
}
/* qmgr_active_drain - drain active queue by allocating a delivery process */
void qmgr_active_drain(void)
{
QMGR_TRANSPORT *transport;
/*
* Allocate one delivery process for every transport with pending mail.
* The process allocation completes asynchronously.
*/
while ((transport = qmgr_transport_select()) != 0) {
if (msg_verbose)
msg_info("qmgr_active_drain: allocate %s", transport->name);
qmgr_transport_alloc(transport, qmgr_deliver);
}
}