/*++
/* NAME
/*	postsuper 1
/* SUMMARY
/*	Postfix superintendent
/* SYNOPSIS
/* .fi
/*	\fBpostsuper\fR [\fB-psSv\fR]
/*		[\fB-c \fIconfig_dir\fR] [\fB-d \fIqueue_id\fR]
/*		[\fB-e \fIqueue_id\fR] [\fB-f \fIqueue_id\fR]
/*		[\fB-h \fIqueue_id\fR] [\fB-H \fIqueue_id\fR]
/*		[\fB-r \fIqueue_id\fR] [\fIdirectory ...\fR]
/* DESCRIPTION
/*	The \fBpostsuper\fR(1) command does maintenance jobs on the Postfix
/*	queue. Use of the command is restricted to the superuser.
/*	See the \fBpostqueue\fR(1) command for unprivileged queue operations
/*	such as listing or flushing the mail queue.
/*
/*	By default, \fBpostsuper\fR(1) performs the operations
/*	requested with the
/*	\fB-s\fR and \fB-p\fR command-line options on all Postfix queue
/*	directories - this includes the \fBincoming\fR, \fBactive\fR,
/*	\fBdeferred\fR, and \fBhold\fR directories with message
/*	files and the \fBbounce\fR,
/*	\fBdefer\fR, \fBtrace\fR and \fBflush\fR directories with log files.
/*
/*	Options:
/* .IP "\fB-c \fIconfig_dir\fR"
/*	The \fBmain.cf\fR configuration file is in the named directory
/*	instead of the default configuration directory. See also the
/*	MAIL_CONFIG environment setting below.
/* .IP "\fB-d \fIqueue_id\fR"
/*	Delete one message with the named queue ID from the named
/*	mail queue(s) (default: \fBhold\fR, \fBincoming\fR, \fBactive\fR and
/*	\fBdeferred\fR).
/*
/*	To delete multiple files, specify the \fB-d\fR option multiple
/*	times, or specify a \fIqueue_id\fR of \fB-\fR to read queue IDs
/*	from standard input. For example, to delete all mail
/*	with exactly one recipient \fBuser@example.com\fR:
/* .sp
/* .nf
/*	postqueue -j | jq -r '
/*	    # See JSON OBJECT FORMAT section in the postqueue(1) manpage
/*	    select(.recipients[0].address == "user@example.com")
/*	    | select(.recipients[1].address == null)
/*	    | .queue_id
/*	 ' | postsuper -d -
/* .fi
/* .sp
/*	(note the "jq -r" option), or the historical form:
/* .sp
/* .nf
/*	mailq | tail -n +2 | grep -v '^ *(' | awk  'BEGIN { RS = "" }
/*	    # $7=sender, $8=recipient1, $9=recipient2
/*	    { if ($8 == "user@example.com" && $9 == "")
/*	          print $1 }
/*	 ' | tr -d '*!' | postsuper -d -
/* .fi
/* .sp
/*	Specify "\fB-d ALL\fR" to remove all messages; for example, specify
/*	"\fB-d ALL deferred\fR" to delete all mail in the \fBdeferred\fR queue.
/*	As a safety measure, the word \fBALL\fR must be specified in upper
/*	case.
/* .sp
/*	Warning: Postfix queue IDs are reused (always with Postfix
/*	<= 2.8; and with Postfix >= 2.9 when enable_long_queue_ids=no).
/*	There is a very small possibility that postsuper deletes the
/*	wrong message file when it is executed while the Postfix mail
/*	system is delivering mail.
/* .sp
/*	The scenario is as follows:
/* .RS
/* .IP 1)
/*	The Postfix queue manager deletes the message that \fBpostsuper\fR(1)
/*	is asked to delete, because Postfix is finished with the
/*	message (it is delivered, or it is returned to the sender).
/* .IP 2)
/*	New mail arrives, and the new message is given the same queue ID
/*	as the message that \fBpostsuper\fR(1) is supposed to delete.
/*	The probability for reusing a deleted queue ID is about 1 in 2**15
/*	(the number of different microsecond values that the system clock
/*	can distinguish within a second).
/* .IP 3)
/*	\fBpostsuper\fR(1) deletes the new message, instead of the old
/*	message that it should have deleted.
/* .RE
/* .IP "\fB-e \fIqueue_id\fR"
/* .IP "\fB-f \fIqueue_id\fR"
/*	Request forced expiration for one message with the named
/*	queue ID in the named mail queue(s) (default: \fBhold\fR,
/*	\fBincoming\fR, \fBactive\fR and \fBdeferred\fR).
/* .RS
/* .IP \(bu
/*	The message will be returned to the sender when the queue
/*	manager attempts to deliver that message (note that Postfix
/*	will never deliver messages in the \fBhold\fR queue).
/* .IP \(bu
/*	The \fB-e\fR and \fB-f\fR options both request forced
/*	expiration. The difference is that \fB-f\fR will also release
/*	a message if it is in the \fBhold\fR queue. With \fB-e\fR, such
/*	a message would not be returned to the sender until it is
/*	released with \fB-f\fR or \fB-H\fR.
/* .IP \(bu
/*	When a deferred message is force-expired, the return message
/*	will state the reason for the delay. Otherwise, the reason
/*	will be "message is administratively expired".
/* .RE
/* .IP
/*	To expire multiple files, specify the \fB-e\fR or \fB-f\fR
/*	option multiple times, or specify a \fIqueue_id\fR of \fB-\fR
/*	to read queue IDs from standard input (see the \fB-d\fR option
/*	above for an example, but be sure to replace \fB-d\fR in
/*	the example).
/* .sp
/*	Specify "\fB-e ALL\fR" or "\fB-f ALL\fR" to expire all
/*	messages; for example, specify "\fB-e ALL deferred\fR" to
/*	expire all mail in the \fBdeferred\fR queue.  As a safety
/*	measure, the word \fBALL\fR must be specified in upper case.
/* .sp
/*	These features are available in Postfix 3.5 and later.
/* .IP "\fB-h \fIqueue_id\fR"
/*	Put mail "on hold" so that no attempt is made to deliver it.
/*	Move one message with the named queue ID from the named
/*	mail queue(s) (default: \fBincoming\fR, \fBactive\fR and
/*	\fBdeferred\fR) to the \fBhold\fR queue.
/*
/*	To hold multiple files, specify the \fB-h\fR option multiple
/*	times, or specify a \fIqueue_id\fR of \fB-\fR to read queue IDs
/*	from standard input.
/* .sp
/*	Specify "\fB-h ALL\fR" to hold all messages; for example, specify
/*	"\fB-h ALL deferred\fR" to hold all mail in the \fBdeferred\fR queue.
/*	As a safety measure, the word \fBALL\fR must be specified in upper
/*	case.
/* .sp
/*	Note: while mail is "on hold" it will not expire when its
/*	time in the queue exceeds the \fBmaximal_queue_lifetime\fR
/*	or \fBbounce_queue_lifetime\fR setting. It becomes subject to
/*	expiration after it is released from "hold".
/* .sp
/*	This feature is available in Postfix 2.0 and later.
/* .IP "\fB-H \fIqueue_id\fR"
/*	Release mail that was put "on hold".
/*	Move one message with the named queue ID from the named
/*	mail queue(s) (default: \fBhold\fR) to the \fBdeferred\fR queue.
/*
/*	To release multiple files, specify the \fB-H\fR option multiple
/*	times, or specify a \fIqueue_id\fR of \fB-\fR to read queue IDs
/*	from standard input.
/* .sp
/*	Note: specify "\fBpostsuper -r\fR" to release mail that was kept on
/*	hold for a significant fraction of \fB$maximal_queue_lifetime\fR
/*	or \fB$bounce_queue_lifetime\fR, or longer.
/* .sp
/*	Specify "\fB-H ALL\fR" to release all mail that is "on hold".
/*	As a safety measure, the word \fBALL\fR must be specified in upper
/*	case.
/* .sp
/*	This feature is available in Postfix 2.0 and later.
/* .IP \fB-p\fR
/*	Purge old temporary files that are left over after system or
/*	software crashes.
/*	The \fB-p\fR, \fB-s\fR, and \fB-S\fR operations are done
/*	before other operations.
/* .IP "\fB-r \fIqueue_id\fR"
/*	Requeue the message with the named queue ID from the named
/*	mail queue(s) (default: \fBhold\fR, \fBincoming\fR, \fBactive\fR and
/*	\fBdeferred\fR).
/*
/*	To requeue multiple files, specify the \fB-r\fR option multiple
/*	times, or specify a \fIqueue_id\fR of \fB-\fR to read queue IDs
/*	from standard input.
/* .sp
/*	Specify "\fB-r ALL\fR" to requeue all messages. As a safety
/*	measure, the word \fBALL\fR must be specified in upper case.
/* .sp
/*	A requeued message is moved to the \fBmaildrop\fR queue,
/*	from where it is copied by the \fBpickup\fR(8) and
/*	\fBcleanup\fR(8) daemons to a new queue file. In many
/*	respects its handling differs from that of a new local
/*	submission.
/* .RS
/* .IP \(bu
/*	The message is not subjected to the smtpd_milters or
/*	non_smtpd_milters settings.  When mail has passed through
/*	an external content filter, this would produce incorrect
/*	results with Milter applications that depend on original
/*	SMTP connection state information.
/* .IP \(bu
/*	The message is subjected again to mail address rewriting
/*	and substitution.  This is useful when rewriting rules or
/*	virtual mappings have changed.
/* .sp
/*	The address rewriting context (local or remote) is the same
/*	as when the message was received.
/* .IP \(bu
/*	The message is subjected to the same content_filter settings
/*	(if any) as used for new local mail submissions.  This is
/*	useful when content_filter settings have changed.
/* .RE
/* .IP
/*	Warning: Postfix queue IDs are reused (always with Postfix
/*	<= 2.8; and with Postfix >= 2.9 when enable_long_queue_ids=no).
/*	There is a very small possibility that \fBpostsuper\fR(1) requeues
/*	the wrong message file when it is executed while the Postfix mail
/*	system is running, but no harm should be done.
/* .sp
/*	This feature is available in Postfix 1.1 and later.
/* .IP \fB-s\fR
/*	Structure check and structure repair.  This should be done once
/*	before Postfix startup.
/*	The \fB-p\fR, \fB-s\fR, and \fB-S\fR operations are done
/*	before other operations.
/* .RS
/* .IP \(bu
/*	Rename files whose name does not match the message file inode
/*	number. This operation is necessary after restoring a mail
/*	queue from a different machine or from backup, when queue
/*	files were created with Postfix <= 2.8 or with
/*	"enable_long_queue_ids = no".
/* .IP \(bu
/*	Move queue files that are in the wrong place in the file system
/*	hierarchy and remove subdirectories that are no longer needed.
/*	File position rearrangements are necessary after a change in the
/*	\fBhash_queue_names\fR and/or \fBhash_queue_depth\fR
/*	configuration parameters.
/* .IP \(bu
/*	Rename queue files created with "enable_long_queue_ids =
/*	yes" to short names, for migration to Postfix <= 2.8.  The
/*	procedure is as follows:
/* .sp
/* .nf
/* .na
/*	# postfix stop
/*	# postconf enable_long_queue_ids=no
/*	# postsuper
/* .ad
/* .fi
/* .sp
/*	Run \fBpostsuper\fR(1) repeatedly until it stops reporting
/*	file name changes.
/* .RE
/* .IP \fB-S\fR
/*	A redundant version of \fB-s\fR that requires that long
/*	file names also match the message file inode number. This
/*	option exists for testing purposes, and is available with
/*	Postfix 2.9 and later.
/*	The \fB-p\fR, \fB-s\fR, and \fB-S\fR operations are done
/*	before other operations.
/* .IP \fB-v\fR
/*	Enable verbose logging for debugging purposes. Multiple \fB-v\fR
/*	options make the software increasingly verbose.
/* DIAGNOSTICS
/*	Problems are reported to the standard error stream and to
/*	\fBsyslogd\fR(8) or \fBpostlogd\fR(8).
/*
/*	\fBpostsuper\fR(1) reports the number of messages deleted
/*	with \fB-d\fR, the number of messages expired with \fB-e\fR,
/*	the number of messages expired or released with \fB-f\fR,
/*	the number of messages held or released with \fB-h\fR or
/*	\fB-H\fR, the number of messages requeued with \fB-r\fR,
/*	and the number of messages whose queue file name was fixed
/*	with \fB-s\fR. The report is written to the standard error
/*	stream and to \fBsyslogd\fR(8) or \fBpostlogd\fR(8).
/* ENVIRONMENT
/* .ad
/* .fi
/* .IP MAIL_CONFIG
/*	Directory with the \fBmain.cf\fR file.
/* BUGS
/*	Mail that is not sanitized by Postfix (i.e. mail in the \fBmaildrop\fR
/*	queue) cannot be placed "on hold".
/* CONFIGURATION PARAMETERS
/* .ad
/* .fi
/*	The following \fBmain.cf\fR parameters are especially relevant to
/*	this program.
/*	The text below provides only a parameter summary. See
/*	\fBpostconf\fR(5) for more details including examples.
/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
/*	The default location of the Postfix main.cf and master.cf
/*	configuration files.
/* .IP "\fBhash_queue_depth (1)\fR"
/*	The number of subdirectory levels for queue directories listed with
/*	the hash_queue_names parameter.
/* .IP "\fBhash_queue_names (deferred, defer)\fR"
/*	The names of queue directories that are split across multiple
/*	subdirectory levels.
/* .IP "\fBimport_environment (see 'postconf -d' output)\fR"
/*	The list of environment variables that a privileged Postfix
/*	process will import from a non-Postfix parent process, or name=value
/*	environment overrides.
/* .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 2.9 and later:
/* .IP "\fBenable_long_queue_ids (no)\fR"
/*	Enable long, non-repeating, queue IDs (queue file names).
/* SEE ALSO
/*	sendmail(1), Sendmail-compatible user interface
/*	postqueue(1), unprivileged queue operations
/*	postlogd(8), Postfix logging
/*	syslogd(8), system logging
/* 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 <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <stdio.h>			/* remove() */
#include <utime.h>

/* Utility library. */

#include <mymalloc.h>
#include <msg.h>
#include <vstream.h>
#include <msg_vstream.h>
#include <scan_dir.h>
#include <vstring.h>
#include <safe.h>
#include <set_ugid.h>
#include <argv.h>
#include <vstring_vstream.h>
#include <sane_fsops.h>
#include <myrand.h>
#include <warn_stat.h>
#include <clean_env.h>
#include <safe_open.h>
#include <name_mask.h>

/* Global library. */

#include <mail_task.h>
#include <mail_conf.h>
#include <mail_params.h>
#include <mail_version.h>
#define MAIL_QUEUE_INTERNAL
#include <mail_queue.h>
#include <mail_open_ok.h>
#include <file_id.h>
#include <mail_parm_split.h>
#include <maillog_client.h>

/* Application-specific. */

#define MAX_TEMP_AGE (7 * 60 * 60 * 24)	/* temp file maximal age */
#define STR vstring_str			/* silly little macro */

#define ACTION_STRUCT	(1<<0)		/* fix file organization */
#define ACTION_PURGE	(1<<1)		/* purge old temp files */
#define ACTION_DELETE_ONE (1<<2)	/* delete named queue file(s) */
#define ACTION_DELETE_ALL (1<<3)	/* delete all queue file(s) */
#define ACTION_REQUEUE_ONE (1<<4)	/* requeue named queue file(s) */
#define ACTION_REQUEUE_ALL (1<<5)	/* requeue all queue file(s) */
#define ACTION_HOLD_ONE	(1<<6)		/* put named queue file(s) on hold */
#define ACTION_HOLD_ALL	(1<<7)		/* put all messages on hold */
#define ACTION_RELEASE_ONE (1<<8)	/* release named queue file(s) */
#define ACTION_RELEASE_ALL (1<<9)	/* release all "on hold" mail */
#define ACTION_STRUCT_RED (1<<10)	/* fix long queue ID inode fields */
#define ACTION_EXPIRE_ONE (1<<11)	/* expire named queue file(s) */
#define ACTION_EXPIRE_ALL (1<<12)	/* expire all queue file(s) */
#define ACTION_EXP_REL_ONE (1<<13)	/* expire+release named queue file(s) */
#define ACTION_EXP_REL_ALL (1<<14)	/* expire+release all queue file(s) */

#define ACTION_DEFAULT	(ACTION_STRUCT | ACTION_PURGE)

 /*
  * Actions that operate on individually named queue files. These must never
  * be done after fixing queue file names to match their inode number because
  * the target file may have been replaced. Actions that move files are safe
  * only when queue file names match their inode number, otherwise mail can
  * be lost due to filename collisions.
  */
#define ACTIONS_BY_QUEUE_ID	(ACTION_DELETE_ONE | ACTION_REQUEUE_ONE \
				| ACTION_HOLD_ONE | ACTION_RELEASE_ONE \
				| ACTION_EXPIRE_ONE | ACTION_EXP_REL_ONE)

 /*
  * Mass actions. Actions that move files are safe only when queue file names
  * match their inode number, otherwise mail can be lost due to filename
  * collisions.
  */
#define ACTIONS_BY_WILDCARD	(ACTION_DELETE_ALL | ACTION_REQUEUE_ALL \
				| ACTION_HOLD_ALL | ACTION_RELEASE_ALL \
				| ACTION_EXPIRE_ALL | ACTION_EXP_REL_ALL)

#define ACTIONS_FOR_REPAIR	(ACTION_PURGE | ACTION_STRUCT \
				| ACTION_STRUCT_RED)

 /*
  * Information about queue directories and what we expect to do there. If a
  * file has unexpected owner permissions and is older than some threshold,
  * the file is discarded. We don't step into maildrop subdirectories - if
  * maildrop is writable, we might end up in the wrong place, deleting the
  * wrong information.
  */
struct queue_info {
    char   *name;			/* directory name */
    int     perms;			/* expected permissions */
    int     flags;			/* see below */
};

#define RECURSE		(1<<0)		/* step into subdirectories */
#define	DONT_RECURSE	0		/* don't step into directories */

static struct queue_info queue_info[] = {
    MAIL_QUEUE_MAILDROP, MAIL_QUEUE_STAT_READY, DONT_RECURSE,
    MAIL_QUEUE_INCOMING, MAIL_QUEUE_STAT_READY, RECURSE,
    MAIL_QUEUE_ACTIVE, MAIL_QUEUE_STAT_READY, RECURSE,
    MAIL_QUEUE_DEFERRED, MAIL_QUEUE_STAT_READY, RECURSE,
    MAIL_QUEUE_HOLD, MAIL_QUEUE_STAT_READY, RECURSE,
    MAIL_QUEUE_TRACE, 0600, RECURSE,
    MAIL_QUEUE_DEFER, 0600, RECURSE,
    MAIL_QUEUE_BOUNCE, 0600, RECURSE,
    MAIL_QUEUE_FLUSH, 0600, RECURSE,
    0,
};

 /*
  * Directories with per-message meta files.
  */
const char *log_queue_names[] = {
    MAIL_QUEUE_BOUNCE,
    MAIL_QUEUE_DEFER,
    MAIL_QUEUE_TRACE,
    0,
};

 /*
  * Cruft that we append to a file name when a queue ID is named after the
  * message file inode number. This cruft must not pass mail_queue_id_ok() so
  * that the queue manager will ignore it, should people be so unwise as to
  * run this operation on a live mail system.
  */
#define SUFFIX		"#FIX"
#define SUFFIX_LEN	4

 /*
  * Grr. These counters are global, because C only has clumsy ways to return
  * multiple results from a function.
  */
static int message_requeued = 0;	/* requeued messages */
static int message_held = 0;		/* messages put on hold */
static int message_released = 0;	/* messages released from hold */
static int message_deleted = 0;		/* deleted messages */
static int message_expired = 0;		/* expired messages */
static int inode_fixed = 0;		/* queue id matched to inode number */
static int inode_mismatch = 0;		/* queue id inode mismatch */
static int position_mismatch = 0;	/* file position mismatch */

 /*
  * Silly little macros. These translate arcane expressions into something
  * more at a conceptual level.
  */
#define MESSAGE_QUEUE(qp) ((qp)->perms == MAIL_QUEUE_STAT_READY)
#define READY_MESSAGE(st) (((st).st_mode & S_IRWXU) == MAIL_QUEUE_STAT_READY)

/* find_queue_info - look up expected permissions field by queue name */

static struct queue_info *find_queue_info(const char *queue_name)
{
    struct queue_info *qp;

    for (qp = queue_info; qp->name; qp++)
	if (strcmp(queue_name, qp->name) == 0)
	    return (qp);
    msg_fatal("invalid directory name: %s", queue_name);
}

/* postremove - remove file with extreme prejudice */

static int postremove(const char *path)
{
    int     ret;

    if ((ret = remove(path)) < 0) {
	if (errno != ENOENT)
	    msg_fatal("remove file %s: %m", path);
    } else {
	if (msg_verbose)
	    msg_info("removed file %s", path);
    }
    return (ret);
}

/* postexpire - expire file, setting the group execute permission */

static int postexpire(const char *path)
{
    static VSTRING *why = 0;
    VSTREAM *fp;
    struct stat st;

    /*
     * Initialize.
     */
    if (why == 0)
	why = vstring_alloc(100);

    /*
     * We don't actually verify the file content, therefore safe_open() the
     * queue file so that we won't add group execute permission to some file
     * outside of the mail queue.
     */
    if ((fp = safe_open(path, O_RDWR, 0, &st, -1, -1, why)) == 0) {
	if (errno != ENOENT)
	    msg_warn("expire file %s: %s", path, vstring_str(why));
	return (-1);
    }
#define POSTEXPIRE_RETURN(x) do { \
	(void) vstream_fclose(fp); \
	return (x); \
    } while (0)

    if (!READY_MESSAGE(st))
	POSTEXPIRE_RETURN(-1);			/* must not expire */
    if ((st.st_mode & MAIL_QUEUE_STAT_EXPIRE) != 0)
	POSTEXPIRE_RETURN(-1);			/* already expired */
    if (fchmod(vstream_fileno(fp),
	       (st.st_mode | MAIL_QUEUE_STAT_EXPIRE) & ~S_IFMT) < 0) {
	msg_warn("expire file %s: cannot set permission: %m", path);
	POSTEXPIRE_RETURN(-1);
    }
    POSTEXPIRE_RETURN(0);
}

/* postrename - rename file with extreme prejudice */

static int postrename(const char *old, const char *new)
{
    int     ret;

    if ((ret = sane_rename(old, new)) < 0) {
	if (errno != ENOENT
	    || mail_queue_mkdirs(new) < 0
	    || (ret = sane_rename(old, new)) < 0)
	    if (errno != ENOENT)
		msg_fatal("rename file %s as %s: %m", old, new);
    } else {
	if (msg_verbose)
	    msg_info("renamed file %s as %s", old, new);
    }
    return (ret);
}

/* postrmdir - remove directory with extreme prejudice */

static int postrmdir(const char *path)
{
    int     ret;

    if ((ret = rmdir(path)) < 0) {
	if (errno != ENOENT)
	    msg_fatal("remove directory %s: %m", path);
    } else {
	if (msg_verbose)
	    msg_info("remove directory %s", path);
    }
    return (ret);
}

/* delete_one - delete one message instance and all its associated files */

static void delete_one(const char **queue_names, const char *queue_id)
{
    struct stat st;
    const char **msg_qpp;
    const char **log_qpp;
    const char *msg_path;
    VSTRING *log_path_buf;
    int     found;
    int     tries;

    /*
     * Sanity check. No early returns beyond this point.
     */
    if (!mail_queue_id_ok(queue_id)) {
	msg_warn("invalid mail queue id: %s", queue_id);
	return;
    }
    log_path_buf = vstring_alloc(100);

    /*
     * Skip meta file directories. Delete trace/defer/bounce logfiles before
     * deleting the corresponding message file, and only if the message file
     * exists. This minimizes but does not eliminate a race condition with
     * queue ID reuse which results in deleting the wrong files.
     */
    for (found = 0, tries = 0; found == 0 && tries < 2; tries++) {
	for (msg_qpp = queue_names; *msg_qpp != 0; msg_qpp++) {
	    if (!MESSAGE_QUEUE(find_queue_info(*msg_qpp)))
		continue;
	    if (mail_open_ok(*msg_qpp, queue_id, &st, &msg_path) != MAIL_OPEN_YES)
		continue;
	    for (log_qpp = log_queue_names; *log_qpp != 0; log_qpp++)
		postremove(mail_queue_path(log_path_buf, *log_qpp, queue_id));
	    if (postremove(msg_path) == 0) {
		found = 1;
		msg_info("%s: removed", queue_id);
		break;
	    }					/* else: maybe lost a race */
	}
    }
    vstring_free(log_path_buf);
    message_deleted += found;
}

/* requeue_one - requeue one message instance and delete its logfiles */

static void requeue_one(const char **queue_names, const char *queue_id)
{
    struct stat st;
    const char **msg_qpp;
    const char *old_path;
    VSTRING *new_path_buf;
    int     found;
    int     tries;
    struct utimbuf tbuf;

    /*
     * Sanity check. No early returns beyond this point.
     */
    if (!mail_queue_id_ok(queue_id)) {
	msg_warn("invalid mail queue id: %s", queue_id);
	return;
    }
    new_path_buf = vstring_alloc(100);

    /*
     * Skip meta file directories. Like the mass requeue operation, we not
     * delete defer or bounce logfiles, to avoid losing a race where the
     * queue manager decides to bounce mail after all recipients have been
     * tried.
     */
    for (found = 0, tries = 0; found == 0 && tries < 2; tries++) {
	for (msg_qpp = queue_names; *msg_qpp != 0; msg_qpp++) {
	    if (strcmp(*msg_qpp, MAIL_QUEUE_MAILDROP) == 0)
		continue;
	    if (!MESSAGE_QUEUE(find_queue_info(*msg_qpp)))
		continue;
	    if (mail_open_ok(*msg_qpp, queue_id, &st, &old_path) != MAIL_OPEN_YES)
		continue;
	    (void) mail_queue_path(new_path_buf, MAIL_QUEUE_MAILDROP, queue_id);
	    if (postrename(old_path, STR(new_path_buf)) == 0) {
		tbuf.actime = tbuf.modtime = time((time_t *) 0);
		if (utime(STR(new_path_buf), &tbuf) < 0)
		    msg_warn("%s: reset time stamps: %m", STR(new_path_buf));
		msg_info("%s: requeued", queue_id);
		found = 1;
		break;
	    }					/* else: maybe lost a race */
	}
    }
    vstring_free(new_path_buf);
    message_requeued += found;
}

/* hold_one - put "on hold" one message instance */

static void hold_one(const char **queue_names, const char *queue_id)
{
    struct stat st;
    const char **msg_qpp;
    const char *old_path;
    VSTRING *new_path_buf;
    int     found;
    int     tries;

    /*
     * Sanity check. No early returns beyond this point.
     */
    if (!mail_queue_id_ok(queue_id)) {
	msg_warn("invalid mail queue id: %s", queue_id);
	return;
    }
    new_path_buf = vstring_alloc(100);

    /*
     * Skip meta file directories. Like the mass requeue operation, we not
     * delete defer or bounce logfiles, to avoid losing a race where the
     * queue manager decides to bounce mail after all recipients have been
     * tried.
     * 
     * XXX We must not put maildrop mail on hold because that would mix already
     * sanitized mail with mail that still needs to be sanitized.
     */
    for (found = 0, tries = 0; found == 0 && tries < 2; tries++) {
	for (msg_qpp = queue_names; *msg_qpp != 0; msg_qpp++) {
	    if (strcmp(*msg_qpp, MAIL_QUEUE_MAILDROP) == 0)
		continue;
	    if (strcmp(*msg_qpp, MAIL_QUEUE_HOLD) == 0)
		continue;
	    if (!MESSAGE_QUEUE(find_queue_info(*msg_qpp)))
		continue;
	    if (mail_open_ok(*msg_qpp, queue_id, &st, &old_path) != MAIL_OPEN_YES)
		continue;
	    (void) mail_queue_path(new_path_buf, MAIL_QUEUE_HOLD, queue_id);
	    if (postrename(old_path, STR(new_path_buf)) == 0) {
		msg_info("%s: placed on hold", queue_id);
		found = 1;
		break;
	    }					/* else: maybe lost a race */
	}
    }
    vstring_free(new_path_buf);
    message_held += found;
}

/* release_one - release one message instance that was placed "on hold" */

static void release_one(const char **queue_names, const char *queue_id)
{
    struct stat st;
    const char **msg_qpp;
    const char *old_path;
    VSTRING *new_path_buf;
    int     found;

    /*
     * Sanity check. No early returns beyond this point.
     */
    if (!mail_queue_id_ok(queue_id)) {
	msg_warn("invalid mail queue id: %s", queue_id);
	return;
    }
    new_path_buf = vstring_alloc(100);

    /*
     * Skip inapplicable directories. This can happen when -H is combined
     * with other operations.
     */
    found = 0;
    for (msg_qpp = queue_names; *msg_qpp != 0; msg_qpp++) {
	if (strcmp(*msg_qpp, MAIL_QUEUE_HOLD) != 0)
	    continue;
	if (mail_open_ok(*msg_qpp, queue_id, &st, &old_path) != MAIL_OPEN_YES)
	    continue;
	(void) mail_queue_path(new_path_buf, MAIL_QUEUE_DEFERRED, queue_id);
	if (postrename(old_path, STR(new_path_buf)) == 0) {
	    msg_info("%s: released from hold", queue_id);
	    found = 1;
	    break;
	}
    }
    vstring_free(new_path_buf);
    message_released += found;
}

/* expire_one - expire one message instance */

static void expire_one(const char **queue_names, const char *queue_id)
{
    struct stat st;
    const char **msg_qpp;
    const char *msg_path;
    int     found;
    int     tries;

    /*
     * Sanity check. No early returns beyond this point.
     */
    if (!mail_queue_id_ok(queue_id)) {
	msg_warn("invalid mail queue id: %s", queue_id);
	return;
    }

    /*
     * Skip meta file directories.
     */
    for (found = 0, tries = 0; found == 0 && tries < 2; tries++) {
	for (msg_qpp = queue_names; *msg_qpp != 0; msg_qpp++) {
	    if (!MESSAGE_QUEUE(find_queue_info(*msg_qpp)))
		continue;
	    if (strcmp(*msg_qpp, MAIL_QUEUE_MAILDROP) == 0)
		continue;
	    if (mail_open_ok(*msg_qpp, queue_id, &st, &msg_path) != MAIL_OPEN_YES)
		continue;
	    if (postexpire(msg_path) == 0) {
		found = 1;
		msg_info("%s: expired", queue_id);
		break;
	    }					/* else: maybe lost a race */
	}
    }
    message_expired += found;
}

/* exp_rel_one - expire or release one message instance */

static void exp_rel_one(const char **queue_names, const char *queue_id)
{
    expire_one(queue_names, queue_id);
    release_one(queue_names, queue_id);
}

/* operate_stream - operate on queue IDs given on stream */

static void operate_stream(VSTREAM *fp,
		             void (*operator) (const char **, const char *),
			           const char **queues)
{
    VSTRING *buf = vstring_alloc(20);

    while (vstring_get_nonl(buf, fp) != VSTREAM_EOF)
	operator(queues, STR(buf));

    vstring_free(buf);
}

/* fix_queue_id - make message queue ID match inode number */

static int fix_queue_id(const char *actual_path, const char *actual_queue,
			        const char *actual_id, struct stat * st)
{
    VSTRING *old_path = vstring_alloc(10);
    VSTRING *new_path = vstring_alloc(10);
    VSTRING *new_id = vstring_alloc(10);
    const char **log_qpp;
    char   *cp;
    int     ret;

    /*
     * Create the new queue ID from the existing time digits and from the new
     * inode number. Since we are renaming multiple files, the new name must
     * be deterministic so that we can recover even when the renaming
     * operation is interrupted in the middle.
     */
    if (MQID_FIND_LG_INUM_SEPARATOR(cp, actual_id) == 0) {
	/* Short->short queue ID. Replace the inode portion. */
	vstring_sprintf(new_id, "%.*s%s",
			MQID_SH_USEC_PAD, actual_id,
			get_file_id_st(st, 0));
    } else if (var_long_queue_ids) {
	/* Long->long queue ID. Replace the inode portion. */
	vstring_sprintf(new_id, "%.*s%c%s",
			(int) (cp - actual_id), actual_id, MQID_LG_INUM_SEP,
			get_file_id_st(st, 1));
    } else {
	/* Long->short queue ID. Reformat time and replace inode portion. */
	MQID_LG_GET_HEX_USEC(new_id, cp);
	vstring_strcat(new_id, get_file_id_st(st, 0));
    }

    /*
     * Rename logfiles before renaming the message file, so that we can
     * recover when a previous attempt was interrupted.
     */
    for (log_qpp = log_queue_names; *log_qpp; log_qpp++) {
	mail_queue_path(old_path, *log_qpp, actual_id);
	mail_queue_path(new_path, *log_qpp, STR(new_id));
	vstring_strcat(new_path, SUFFIX);
	postrename(STR(old_path), STR(new_path));
    }

    /*
     * Rename the message file last, so that we know that we are done with
     * this message and with all its logfiles.
     */
    mail_queue_path(new_path, actual_queue, STR(new_id));
    vstring_strcat(new_path, SUFFIX);
    ret = postrename(actual_path, STR(new_path));

    /*
     * Clean up.
     */
    vstring_free(old_path);
    vstring_free(new_path);
    vstring_free(new_id);

    return (ret);
}

/* super - check queue structure, clean up, do wild-card operations */

static void super(const char **queues, int action)
{
    ARGV   *hash_queue_names = argv_split(var_hash_queue_names, CHARS_COMMA_SP);
    VSTRING *actual_path = vstring_alloc(10);
    VSTRING *wanted_path = vstring_alloc(10);
    struct stat st;
    const char *queue_name;
    SCAN_DIR *info;
    char   *path;
    int     actual_depth;
    int     wanted_depth;
    char  **cpp;
    struct queue_info *qp;
    unsigned long inum;
    int     long_name;
    int     error;

    /*
     * This routine was originally written to do multiple mass operations in
     * one pass. However this hard-coded the order of operations which became
     * difficult to explain. As of Postfix 3.5 this routine is called for one
     * mass operation at a time, in the user-specified order. The exception
     * is that repair operations (purging stale files, queue hashing, and
     * file-inode match) are combined and done before other mass operations.
     */

    /*
     * Make sure every file is in the right place, clean out stale files, and
     * remove non-file/non-directory objects.
     */
    while ((queue_name = *queues++) != 0) {

	if (msg_verbose)
	    msg_info("queue: %s", queue_name);

	/*
	 * Look up queue-specific properties: desired hashing depth, what
	 * file permissions to look for, and whether or not it is desirable
	 * to step into subdirectories.
	 */
	qp = find_queue_info(queue_name);
	for (cpp = hash_queue_names->argv; /* void */ ; cpp++) {
	    if (*cpp == 0) {
		wanted_depth = 0;
		break;
	    }
	    if (strcmp(*cpp, queue_name) == 0) {
		wanted_depth = var_hash_queue_depth;
		break;
	    }
	}

	/*
	 * Sanity check. Some queues just cannot be recursive.
	 */
	if (wanted_depth > 0 && (qp->flags & RECURSE) == 0)
	    msg_fatal("%s queue must not be hashed", queue_name);

	/*
	 * Other per-directory initialization.
	 */
	info = scan_dir_open(queue_name);
	actual_depth = 0;

	for (;;) {

	    /*
	     * If we reach the end of a subdirectory, return to its parent.
	     * Delete subdirectories that are no longer needed.
	     */
	    if ((path = scan_dir_next(info)) == 0) {
		if (actual_depth == 0)
		    break;
		if (actual_depth > wanted_depth)
		    postrmdir(scan_dir_path(info));
		scan_dir_pop(info);
		actual_depth--;
		continue;
	    }

	    /*
	     * If we stumble upon a subdirectory, enter it, if it is
	     * considered safe to do so. Otherwise, try to remove the
	     * subdirectory at a later stage.
	     */
	    if (strlen(path) == 1 && (qp->flags & RECURSE) != 0) {
		actual_depth++;
		scan_dir_push(info, path);
		continue;
	    }

	    /*
	     * From here on we need to keep track of operations that
	     * invalidate or revalidate the actual_path and path variables,
	     * otherwise we can hit the wrong files.
	     */
	    vstring_sprintf(actual_path, "%s/%s", scan_dir_path(info), path);
	    if (lstat(STR(actual_path), &st) < 0)
		continue;

	    /*
	     * Remove alien directories. If maildrop is compromised, then we
	     * cannot abort just because we cannot remove someone's
	     * directory.
	     */
	    if (S_ISDIR(st.st_mode)) {
		if (rmdir(STR(actual_path)) < 0) {
		    if (errno != ENOENT)
			msg_warn("remove subdirectory %s: %m", STR(actual_path));
		} else {
		    if (msg_verbose)
			msg_info("remove subdirectory %s", STR(actual_path));
		}
		/* No further work on this object is possible. */
		continue;
	    }

	    /*
	     * Mass deletion. We count the deletion of mail that this system
	     * has taken responsibility for. XXX This option does not use
	     * mail_queue_remove(), so that it can avoid having to first move
	     * queue files to the "right" subdirectory level.
	     */
	    if (action & ACTION_DELETE_ALL) {
		if (postremove(STR(actual_path)) == 0)
		    if (MESSAGE_QUEUE(qp) && READY_MESSAGE(st))
			message_deleted++;
		/* No further work on this object is possible. */
		continue;
	    }

	    /*
	     * Remove non-file objects and old temporary files. Be careful
	     * not to delete bounce or defer logs just because they are more
	     * than a couple days old.
	     */
	    if (!S_ISREG(st.st_mode)
		|| ((action & ACTION_PURGE) != 0
		    && MESSAGE_QUEUE(qp)
		    && !READY_MESSAGE(st)
		    && time((time_t *) 0) > st.st_mtime + MAX_TEMP_AGE)) {
		(void) postremove(STR(actual_path));
		/* No further work on this object is possible. */
		continue;
	    }

	    /*
	     * Fix queueid#FIX names that were left from a previous pass over
	     * the queue where message queue file names were matched to their
	     * inode number. We strip the suffix and move the file into the
	     * proper subdirectory level. Make sure that the name minus
	     * suffix is well formed and that the name matches the file inode
	     * number.
	     */
	    if ((action & ACTION_STRUCT)
		&& strcmp(path + (strlen(path) - SUFFIX_LEN), SUFFIX) == 0) {
		path[strlen(path) - SUFFIX_LEN] = 0;	/* XXX */
		if (!mail_queue_id_ok(path)) {
		    msg_warn("bogus file name: %s", STR(actual_path));
		    continue;
		}
		if (MESSAGE_QUEUE(qp)) {
		    MQID_GET_INUM(path, inum, long_name, error);
		    if (error) {
			msg_warn("bogus file name: %s", STR(actual_path));
			continue;
		    }
		    if (inum != (unsigned long) st.st_ino) {
			msg_warn("name/inode mismatch: %s", STR(actual_path));
			continue;
		    }
		}
		(void) mail_queue_path(wanted_path, queue_name, path);
		if (postrename(STR(actual_path), STR(wanted_path)) < 0) {
		    /* No further work on this object is possible. */
		    continue;
		} else {
		    if (MESSAGE_QUEUE(qp))
			inode_fixed++;
		    vstring_strcpy(actual_path, STR(wanted_path));
		    /* At this point, path and actual_path are revalidated. */
		}
	    }

	    /*
	     * Skip over files with illegal names. The library routines
	     * refuse to operate on them.
	     */
	    if (!mail_queue_id_ok(path)) {
		msg_warn("bogus file name: %s", STR(actual_path));
		continue;
	    }

	    /*
	     * See if the file name matches the file inode number. Skip meta
	     * file directories. This option requires that meta files be put
	     * into their proper place before queue files, so that we can
	     * rename queue files and meta files at the same time. Mis-named
	     * files are renamed to newqueueid#FIX on the first pass, and
	     * upon the second pass the #FIX is stripped off the name. Of
	     * course we have to be prepared that the program is interrupted
	     * before it completes, so any left-over newqueueid#FIX files
	     * have to be handled properly. XXX This option cannot use
	     * mail_queue_rename(), because the queue file name violates
	     * normal queue file syntax.
	     * 
	     * By design there is no need to "fix" non-repeating names. What
	     * follows is applicable only when reverting from long names to
	     * short names, or when migrating short names from one queue to
	     * another.
	     */
	    if ((action & ACTION_STRUCT) != 0 && MESSAGE_QUEUE(qp)) {
		MQID_GET_INUM(path, inum, long_name, error);
		if (error) {
		    msg_warn("bogus file name: %s", STR(actual_path));
		    continue;
		}
		if ((long_name != 0 && var_long_queue_ids == 0)
		    || (inum != (unsigned long) st.st_ino
		     && (long_name == 0 || (action & ACTION_STRUCT_RED)))) {
		    inode_mismatch++;		/* before we fix */
		    action &= ~ACTIONS_BY_WILDCARD;
		    fix_queue_id(STR(actual_path), queue_name, path, &st);
		    /* At this point, path and actual_path are invalidated. */
		    continue;
		}
	    }

	    /*
	     * Mass requeuing. The pickup daemon will copy requeued mail to a
	     * new queue file, so that address rewriting is applied again.
	     * XXX This option does not use mail_queue_rename(), so that it
	     * can avoid having to first move queue files to the "right"
	     * subdirectory level. Like the requeue_one() routine, this code
	     * does not touch logfiles.
	     */
	    if ((action & ACTION_REQUEUE_ALL)
		&& MESSAGE_QUEUE(qp)
		&& strcmp(queue_name, MAIL_QUEUE_MAILDROP) != 0) {
		(void) mail_queue_path(wanted_path, MAIL_QUEUE_MAILDROP, path);
		if (postrename(STR(actual_path), STR(wanted_path)) == 0)
		    message_requeued++;
		/* At this point, path and actual_path are invalidated. */
		continue;
	    }

	    /*
	     * Many of the following actions may move queue files. To avoid
	     * loss of email due to file name collisions. we should do such
	     * actions only when the queue file names are known to match
	     * their inode number. Even with non-repeating queue IDs a name
	     * collision may happen when different queues are merged.
	     */

	    /*
	     * Mass expiration. We count the expiration of mail that this
	     * system has taken responsibility for.
	     */
	    if ((action & (ACTION_EXPIRE_ALL | ACTION_EXP_REL_ALL))
		&& MESSAGE_QUEUE(qp) && READY_MESSAGE(st)
		&& strcmp(queue_name, MAIL_QUEUE_MAILDROP) != 0
		&& postexpire(STR(actual_path)) == 0)
		message_expired++;

	    /*
	     * Mass renaming to the "on hold" queue. XXX This option does not
	     * use mail_queue_rename(), so that it can avoid having to first
	     * move queue files to the "right" subdirectory level. Like the
	     * hold_one() routine, this code does not touch logfiles, and
	     * must not touch files in the maildrop queue, because maildrop
	     * files contain data that has not yet been sanitized and
	     * therefore must not be mixed with already sanitized mail.
	     */
	    if ((action & ACTION_HOLD_ALL)
		&& MESSAGE_QUEUE(qp)
		&& strcmp(queue_name, MAIL_QUEUE_MAILDROP) != 0
		&& strcmp(queue_name, MAIL_QUEUE_HOLD) != 0) {
		(void) mail_queue_path(wanted_path, MAIL_QUEUE_HOLD, path);
		if (postrename(STR(actual_path), STR(wanted_path)) == 0)
		    message_held++;
		/* At this point, path and actual_path are invalidated. */
		continue;
	    }

	    /*
	     * Mass release from the "on hold" queue. XXX This option does
	     * not use mail_queue_rename(), so that it can avoid having to
	     * first move queue files to the "right" subdirectory level. Like
	     * the release_one() routine, this code must not touch logfiles.
	     */
	    if ((action & (ACTION_RELEASE_ALL | ACTION_EXP_REL_ALL))
		&& strcmp(queue_name, MAIL_QUEUE_HOLD) == 0) {
		(void) mail_queue_path(wanted_path, MAIL_QUEUE_DEFERRED, path);
		if (postrename(STR(actual_path), STR(wanted_path)) == 0)
		    message_released++;
		/* At this point, path and actual_path are invalidated. */
		continue;
	    }

	    /*
	     * See if this file sits in the right place in the file system
	     * hierarchy. Its place may be wrong after a change to the
	     * hash_queue_{names,depth} parameter settings. This requires
	     * that the bounce/defer logfiles be at the right subdirectory
	     * level first, otherwise we would fail to properly rename
	     * bounce/defer logfiles.
	     */
	    if (action & ACTION_STRUCT) {
		(void) mail_queue_path(wanted_path, queue_name, path);
		if (strcmp(STR(actual_path), STR(wanted_path)) != 0) {
		    position_mismatch++;	/* before we fix */
		    (void) postrename(STR(actual_path), STR(wanted_path));
		    /* At this point, path and actual_path are invalidated. */
		    continue;
		}
	    }
	}
	scan_dir_close(info);
    }

    /*
     * Clean up.
     */
    vstring_free(wanted_path);
    vstring_free(actual_path);
    argv_free(hash_queue_names);
}

/* interrupted - signal handler */

static void interrupted(int sig)
{

    /*
     * This commands requires root privileges. We therefore do not worry
     * about hostile signals, and report problems via msg_warn().
     * 
     * We use the in-kernel SIGINT handler address as an atomic variable to
     * prevent nested interrupted() calls. For this reason, main() must
     * configure interrupted() as SIGINT handler before other signal handlers
     * are allowed to invoke interrupted(). See also similar code in
     * postdrop.
     */
    if (signal(SIGINT, SIG_IGN) != SIG_IGN) {
	(void) signal(SIGQUIT, SIG_IGN);
	(void) signal(SIGTERM, SIG_IGN);
	(void) signal(SIGHUP, SIG_IGN);
	if (inode_mismatch > 0 || inode_fixed > 0 || position_mismatch > 0)
	    msg_warn("OPERATION INCOMPLETE -- RERUN COMMAND TO FIX THE QUEUE FIRST");
	if (sig)
	    _exit(sig);
    }
}

/* fatal_warning - print warning if queue fix is incomplete */

static void fatal_warning(void)
{
    interrupted(0);
}

MAIL_VERSION_STAMP_DECLARE;

int     main(int argc, char **argv)
{
    int     fd;
    struct stat st;
    char   *slash;
    int     action = 0;
    const char **queues;
    int     c;
    ARGV   *import_env;
    int     saved_optind;

    /*
     * Defaults. The structural checks must fix the directory levels of "log
     * file" directories (bounce, defer) before doing structural checks on
     * the "message file" directories, so that we can find the logfiles in
     * the right place when message files need to be renamed to match their
     * inode number.
     */
    static char *default_queues[] = {
	MAIL_QUEUE_DEFER,		/* before message directories */
	MAIL_QUEUE_BOUNCE,		/* before message directories */
	MAIL_QUEUE_MAILDROP,
	MAIL_QUEUE_INCOMING,
	MAIL_QUEUE_ACTIVE,
	MAIL_QUEUE_DEFERRED,
	MAIL_QUEUE_HOLD,
	MAIL_QUEUE_FLUSH,
	0,
    };

    /*
     * Fingerprint executables and core dumps.
     */
    MAIL_VERSION_STAMP_ALLOCATE;

    /*
     * Be consistent with file permissions.
     */
    umask(022);

    /*
     * To minimize confusion, make sure that the standard file descriptors
     * are open before opening anything else. XXX Work around for 44BSD where
     * fstat can return EBADF on an open file descriptor.
     */
    for (fd = 0; fd < 3; fd++)
	if (fstat(fd, &st) == -1
	    && (close(fd), open("/dev/null", O_RDWR, 0)) != fd)
	    msg_fatal("open /dev/null: %m");

    /*
     * Process this environment option as early as we can, to aid debugging.
     */
    if (safe_getenv(CONF_ENV_VERB))
	msg_verbose = 1;

    /*
     * Initialize logging.
     */
    if ((slash = strrchr(argv[0], '/')) != 0 && slash[1])
	argv[0] = slash + 1;
    msg_vstream_init(argv[0], VSTREAM_ERR);
    maillog_client_init(mail_task(argv[0]),
			MAILLOG_CLIENT_FLAG_LOGWRITER_FALLBACK);
    set_mail_conf_str(VAR_PROCNAME, var_procname = mystrdup(argv[0]));

    /*
     * Check the Postfix library version as soon as we enable logging.
     */
    MAIL_VERSION_CHECK;

    /*
     * Disallow unsafe practices, and refuse to run set-uid (or as the child
     * of a set-uid process). Whenever a privileged wrapper program is
     * needed, it must properly sanitize the real/effective/saved UID/GID,
     * the secondary groups, the process environment, and so on. Otherwise,
     * accidents can happen. If not with Postfix, then with other software.
     */
    if (unsafe() != 0)
	msg_fatal("this postfix command must not run as a set-uid process");
    if (getuid())
	msg_fatal("use of this command is reserved for the superuser");

    /*
     * Parse JCL.
     * 
     * First, find out what kind of actions are requested, without executing
     * them. Later, we execute actions in mostly user-specified order.
     */
#define GETOPT_LIST "c:d:e:f:h:H:pr:sSv"

    saved_optind = optind;
    while ((c = GETOPT(argc, argv, GETOPT_LIST)) > 0) {
	switch (c) {
	default:
	    msg_fatal("usage: %s "
		      "[-c config_dir] "
		      "[-d queue_id (delete)] "
		      "[-e queue_id (expire)] "
		      "[-f queue_id (expire and/or un-hold)] "
		      "[-h queue_id (hold)] [-H queue_id (un-hold)] "
		      "[-p (purge temporary files)] [-r queue_id (requeue)] "
		      "[-s (structure fix)] [-S (redundant structure fix)]"
		      "[-v (verbose)] [queue...]", argv[0]);
	case 'c':
	    if (*optarg != '/')
		msg_fatal("-c requires absolute pathname");
	    if (setenv(CONF_ENV_PATH, optarg, 1) < 0)
		msg_fatal("setenv: %m");
	    break;
	case 'd':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_DELETE_ALL : ACTION_DELETE_ONE);
	    break;
	case 'e':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_EXPIRE_ALL : ACTION_EXPIRE_ONE);
	    break;
	case 'f':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_EXP_REL_ALL : ACTION_EXP_REL_ONE);
	    break;
	case 'h':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_HOLD_ALL : ACTION_HOLD_ONE);
	    break;
	case 'H':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_RELEASE_ALL : ACTION_RELEASE_ONE);
	    break;
	case 'p':
	    action |= ACTION_PURGE;
	    break;
	case 'r':
	    action |= (strcmp(optarg, "ALL") == 0 ?
		       ACTION_REQUEUE_ALL : ACTION_REQUEUE_ONE);
	    break;
	case 'S':
	    action |= ACTION_STRUCT_RED;
	    /* FALLTHROUGH */
	case 's':
	    action |= ACTION_STRUCT;
	    break;
	case 'v':
	    msg_verbose++;
	    break;
	}
    }

    /*
     * Read the global configuration file and extract configuration
     * information. The -c command option can override the default
     * configuration directory location.
     */
    mail_conf_read();
    /* Enforce consistent operation of different Postfix parts. */
    import_env = mail_parm_split(VAR_IMPORT_ENVIRON, var_import_environ);
    update_env(import_env->argv);
    argv_free(import_env);
    /* Re-evaluate mail_task() after reading main.cf. */
    maillog_client_init(mail_task(argv[0]),
			MAILLOG_CLIENT_FLAG_LOGWRITER_FALLBACK);
    if (chdir(var_queue_dir))
	msg_fatal("chdir %s: %m", var_queue_dir);

    /*
     * All file/directory updates must be done as the mail system owner. This
     * is because Postfix daemons manipulate the queue with those same
     * privileges, so directories must be created with the right ownership.
     * 
     * Running as a non-root user is also required for security reasons. When
     * the Postfix queue hierarchy is compromised, an attacker could trick us
     * into entering other file hierarchies and afflicting damage. Running as
     * a non-root user limits the damage to the already compromised mail
     * owner.
     */
    set_ugid(var_owner_uid, var_owner_gid);

    /*
     * Be sure to log a warning if we do not finish structural repair. Maybe
     * we should have an fsck-style "clean" flag so Postfix will not start
     * with a broken queue.
     * 
     * Set up signal handlers after permanently dropping super-user privileges,
     * so that signal handlers will always run with the correct privileges.
     * 
     * XXX Don't enable SIGHUP or SIGTERM if it was ignored by the parent.
     * 
     * interrupted() uses the in-kernel SIGINT handler address as an atomic
     * variable to prevent nested interrupted() calls. For this reason, the
     * SIGINT handler must be configured before other signal handlers are
     * allowed to invoke interrupted(). See also similar code in postdrop.
     */
    signal(SIGINT, interrupted);
    signal(SIGQUIT, interrupted);
    if (signal(SIGTERM, SIG_IGN) == SIG_DFL)
	signal(SIGTERM, interrupted);
    if (signal(SIGHUP, SIG_IGN) == SIG_DFL)
	signal(SIGHUP, interrupted);
    msg_cleanup(fatal_warning);

    /*
     * Execute the explicitly specified (or default) action, on the
     * explicitly specified (or default) queues.
     * 
     * XXX Work around gcc const brain damage.
     * 
     * XXX The file name/inode number fix should always run over all message
     * file directories, and should always be preceded by a subdirectory
     * level check of the bounce and defer logfile directories.
     */
    if (action == 0)
	action = ACTION_DEFAULT;
    if (argv[optind] != 0)
	queues = (const char **) argv + optind;
    else
	queues = (const char **) default_queues;

    /*
     * Basic queue maintenance, including mass name-to-inode fixing. This
     * ensures that queue files are in the right place before any other
     * operations are done.
     */
    if (action & ACTIONS_FOR_REPAIR)
	super(queues, action & ACTIONS_FOR_REPAIR);

    /*
     * If any file names needed changing to match the message file inode
     * number, those files were named newqeueid#FIX. We need a second pass to
     * strip the suffix from the new queue ID, and to complete any requested
     * operations that had to be skipped in the first pass.
     */
    if (inode_mismatch > 0)
	super(queues, action & ACTIONS_FOR_REPAIR);

    /*
     * Don't do actions by queue file name if any queue files changed name
     * because they did not match the queue file inode number. We could be
     * acting on the wrong queue file and lose mail.
     */
    if ((action & ACTIONS_BY_QUEUE_ID)
	&& (inode_mismatch > 0 || inode_fixed > 0)) {
	msg_error("QUEUE FILE NAMES WERE CHANGED TO MATCH INODE NUMBERS");
	msg_fatal("CHECK YOUR QUEUE IDS AND RE-ISSUE THE COMMAND");
    }

    /*
     * Execute actions by queue ID and by wildcard in the user-specified
     * order.
     */
    optind = saved_optind;
    while ((c = GETOPT(argc, argv, GETOPT_LIST)) > 0) {
	switch (c) {
	default:
	    msg_panic("%s: unexpected option: %c", argv[0], c);
	case 'c':
	case 'p':
	case 'S':
	case 's':
	case 'v':
	    /* Already handled. */
	    break;
	case 'd':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_DELETE_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, delete_one, queues);
	    else
		delete_one(queues, optarg);
	    break;
	case 'e':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_EXPIRE_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, expire_one, queues);
	    else
		expire_one(queues, optarg);
	    break;
	case 'f':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_EXP_REL_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, exp_rel_one, queues);
	    else
		exp_rel_one(queues, optarg);
	    break;
	case 'h':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_HOLD_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, hold_one, queues);
	    else
		hold_one(queues, optarg);
	    break;
	case 'H':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_RELEASE_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, release_one, queues);
	    else
		release_one(queues, optarg);
	    break;
	case 'r':
	    if (strcmp(optarg, "ALL") == 0)
		super(queues, ACTION_REQUEUE_ALL);
	    else if (strcmp(optarg, "-") == 0)
		operate_stream(VSTREAM_IN, requeue_one, queues);
	    else
		requeue_one(queues, optarg);
	    break;
	}
    }

    /*
     * Report.
     */
    if (action & (ACTION_REQUEUE_ONE | ACTION_REQUEUE_ALL))
	msg_info("Requeued: %d message%s", message_requeued,
		 message_requeued != 1 ? "s" : "");
    if (action & (ACTION_DELETE_ONE | ACTION_DELETE_ALL))
	msg_info("Deleted: %d message%s", message_deleted,
		 message_deleted != 1 ? "s" : "");
    if (action & (ACTION_EXPIRE_ONE | ACTION_EXPIRE_ALL
		  | ACTION_EXP_REL_ONE | ACTION_EXP_REL_ALL))
	msg_info("Force-expired: %d message%s", message_expired,
		 message_expired != 1 ? "s" : "");
    if (action & (ACTION_HOLD_ONE | ACTION_HOLD_ALL))
	msg_info("Placed on hold: %d message%s",
		 message_held, message_held != 1 ? "s" : "");
    if (action & (ACTION_RELEASE_ONE | ACTION_RELEASE_ALL
		  | ACTION_EXP_REL_ONE | ACTION_EXP_REL_ALL))
	msg_info("Released from hold: %d message%s",
		 message_released, message_released != 1 ? "s" : "");
    if (inode_fixed > 0)
	msg_info("Renamed to match inode number: %d message%s", inode_fixed,
		 inode_fixed != 1 ? "s" : "");
    if (inode_mismatch > 0 || inode_fixed > 0)
	msg_warn("QUEUE FILE NAMES WERE CHANGED TO MATCH INODE NUMBERS");

    exit(0);
}
