1 files changed, 607 insertions, 0 deletions

diff --git a/src/qmgr/qmgr_active.c b/src/qmgr/qmgr_active.c
new file mode 100644
index 0000000..b1c1a4a
--- /dev/null
+++ b/src/qmgr/qmgr_active.c
@@ -0,0 +1,607 @@
+/*++
+/* 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
+/*
+/*	Wietse Venema
+/*	Google, Inc.
+/*	111 8th Avenue
+/*	New York, NY 10011, 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>
+#include <info_log_addr_form.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)
+#define MAYBE_FLUSH_AFTER(mode) \
+	(((mode) & MAIL_QUEUE_STAT_UNTHROTTLE) ? QMGR_FLUSH_AFTER : 0) 
+#define MAYBE_FORCE_EXPIRE(mode) \
+	(((mode) & MAIL_QUEUE_STAT_EXPIRE) ? QMGR_FORCE_EXPIRE : 0)
+#define MAYBE_UPDATE_MODE(mode) \
+	(((mode) & MAIL_QUEUE_STAT_UNTHROTTLE) ? \
+	(mode) & ~MAIL_QUEUE_STAT_UNTHROTTLE : 0)
+
+    if ((message = qmgr_message_alloc(MAIL_QUEUE_ACTIVE, queue_id,
+				      scan_info->flags
+				      | MAYBE_FLUSH_AFTER(st.st_mode)
+				      | MAYBE_FORCE_EXPIRE(st.st_mode),
+				      MAYBE_UPDATE_MODE(st.st_mode))) == 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";
+    const char *expire_status = 0;
+
+    /*
+     * 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 ((message->qflags & QMGR_FORCE_EXPIRE) != 0) {
+	    expire_status = "force-expired";
+	} else if (event_time() >= message->create_time +
+	     (*message->sender ? var_max_queue_time : var_dsn_queue_time)) {
+	    expire_status = "expired";
+	} else {
+	    expire_status = 0;
+	}
+	if (expire_status != 0) {
+	    msg_info("%s: from=<%s>, status=%s, returned to sender",
+	      message->queue_id, info_log_addr_form_sender(message->sender),
+		     expire_status);
+	    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);
+    }
+}