Adding upstream version 3.4.23.upstream/3.4.23upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 1310 insertions, 0 deletions

diff --git a/src/postqueue/Makefile.in b/src/postqueue/Makefile.in
new file mode 100644
index 0000000..f01c3ae
--- /dev/null
+++ b/src/postqueue/Makefile.in
@@ -0,0 +1,133 @@
+SHELL	= /bin/sh
+SRCS	= postqueue.c showq_compat.c showq_json.c
+OBJS	= postqueue.o showq_compat.o showq_json.o
+HDRS	= postqueue.h
+TESTSRC	= 
+DEFS	= -I. -I$(INC_DIR) -D$(SYSTYPE)
+CFLAGS	= $(DEBUG) $(OPT) $(DEFS)
+TESTPROG=
+PROG	= postqueue
+INC_DIR	= ../../include
+LIBS	= ../../lib/lib$(LIB_PREFIX)global$(LIB_SUFFIX) \
+	../../lib/lib$(LIB_PREFIX)util$(LIB_SUFFIX)
+
+.c.o:;	$(CC) $(CFLAGS) -c $*.c
+
+$(PROG): $(OBJS) $(LIBS)
+	$(CC) $(CFLAGS) $(SHLIB_RPATH) -o $@ $(OBJS) $(LIBS) $(SYSLIBS)
+
+$(OBJS): ../../conf/makedefs.out postqueue.h
+
+Makefile: Makefile.in
+	cat ../../conf/makedefs.out $? >$@
+
+test:	$(TESTPROG)
+
+tests:
+
+root_tests:
+
+update: ../../bin/$(PROG)
+
+../../bin/$(PROG): $(PROG)
+	cp $(PROG) ../../bin
+
+printfck: $(OBJS) $(PROG)
+	rm -rf printfck
+	mkdir printfck
+	sed '1,/^# do not edit/!d' Makefile >printfck/Makefile
+	set -e; for i in *.c; do printfck -f .printfck $$i >printfck/$$i; done
+	cd printfck; make "INC_DIR=../../../include" `cd ..; ls *.o`
+
+lint:
+	lint $(DEFS) $(SRCS) $(LINTFIX)
+
+clean:
+	rm -f *.o *core $(PROG) $(TESTPROG) junk 
+	rm -rf printfck
+
+tidy:	clean
+
+depend: $(MAKES)
+	(sed '1,/^# do not edit/!d' Makefile.in; \
+	set -e; for i in [a-z][a-z0-9]*.c; do \
+	    $(CC) -E $(DEFS) $(INCL) $$i | grep -v '[<>]' | sed -n -e '/^# *1 *"\([^"]*\)".*/{' \
+	    -e 's//'`echo $$i|sed 's/c$$/o/'`': \1/' \
+	    -e 's/o: \.\//o: /' -e p -e '}' ; \
+	done | LANG=C sort -u) | grep -v '[.][o][:][ ][/]' >$$$$ && mv $$$$ Makefile.in
+	@$(EXPORT) make -f Makefile.in Makefile 1>&2
+
+# do not edit below this line - it is generated by 'make depend'
+postqueue.o: ../../include/argv.h
+postqueue.o: ../../include/attr.h
+postqueue.o: ../../include/check_arg.h
+postqueue.o: ../../include/clean_env.h
+postqueue.o: ../../include/connect.h
+postqueue.o: ../../include/events.h
+postqueue.o: ../../include/flush_clnt.h
+postqueue.o: ../../include/htable.h
+postqueue.o: ../../include/iostuff.h
+postqueue.o: ../../include/mail_conf.h
+postqueue.o: ../../include/mail_dict.h
+postqueue.o: ../../include/mail_flush.h
+postqueue.o: ../../include/mail_params.h
+postqueue.o: ../../include/mail_parm_split.h
+postqueue.o: ../../include/mail_proto.h
+postqueue.o: ../../include/mail_queue.h
+postqueue.o: ../../include/mail_run.h
+postqueue.o: ../../include/mail_task.h
+postqueue.o: ../../include/mail_version.h
+postqueue.o: ../../include/maillog_client.h
+postqueue.o: ../../include/msg.h
+postqueue.o: ../../include/msg_vstream.h
+postqueue.o: ../../include/mymalloc.h
+postqueue.o: ../../include/nvtable.h
+postqueue.o: ../../include/safe.h
+postqueue.o: ../../include/smtp_stream.h
+postqueue.o: ../../include/stringops.h
+postqueue.o: ../../include/sys_defs.h
+postqueue.o: ../../include/user_acl.h
+postqueue.o: ../../include/valid_hostname.h
+postqueue.o: ../../include/valid_mailhost_addr.h
+postqueue.o: ../../include/vbuf.h
+postqueue.o: ../../include/vstream.h
+postqueue.o: ../../include/vstring.h
+postqueue.o: ../../include/warn_stat.h
+postqueue.o: postqueue.c
+postqueue.o: postqueue.h
+showq_compat.o: ../../include/attr.h
+showq_compat.o: ../../include/check_arg.h
+showq_compat.o: ../../include/htable.h
+showq_compat.o: ../../include/iostuff.h
+showq_compat.o: ../../include/mail_date.h
+showq_compat.o: ../../include/mail_params.h
+showq_compat.o: ../../include/mail_proto.h
+showq_compat.o: ../../include/mail_queue.h
+showq_compat.o: ../../include/msg.h
+showq_compat.o: ../../include/mymalloc.h
+showq_compat.o: ../../include/nvtable.h
+showq_compat.o: ../../include/stringops.h
+showq_compat.o: ../../include/sys_defs.h
+showq_compat.o: ../../include/vbuf.h
+showq_compat.o: ../../include/vstream.h
+showq_compat.o: ../../include/vstring.h
+showq_compat.o: postqueue.h
+showq_compat.o: showq_compat.c
+showq_json.o: ../../include/attr.h
+showq_json.o: ../../include/check_arg.h
+showq_json.o: ../../include/htable.h
+showq_json.o: ../../include/iostuff.h
+showq_json.o: ../../include/mail_date.h
+showq_json.o: ../../include/mail_params.h
+showq_json.o: ../../include/mail_proto.h
+showq_json.o: ../../include/mail_queue.h
+showq_json.o: ../../include/msg.h
+showq_json.o: ../../include/mymalloc.h
+showq_json.o: ../../include/nvtable.h
+showq_json.o: ../../include/stringops.h
+showq_json.o: ../../include/sys_defs.h
+showq_json.o: ../../include/vbuf.h
+showq_json.o: ../../include/vstream.h
+showq_json.o: ../../include/vstring.h
+showq_json.o: postqueue.h
+showq_json.o: showq_json.c
diff --git a/src/postqueue/postqueue.c b/src/postqueue/postqueue.c
new file mode 100644
index 0000000..d838808
--- /dev/null
+++ b/src/postqueue/postqueue.c
@@ -0,0 +1,711 @@
+/*++
+/* NAME
+/*	postqueue 1
+/* SUMMARY
+/*	Postfix queue control
+/* SYNOPSIS
+/* .ti -4
+/*	\fBTo flush the mail queue\fR:
+/*
+/*	\fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-f\fR
+/*
+/*	\fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-i \fIqueue_id\fR
+/*
+/*	\fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-s \fIsite\fR
+/*
+/* .ti -4
+/*	\fBTo list the mail queue\fR:
+/*
+/*	\fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-j\fR
+/*
+/*	\fBpostqueue\fR [\fB-v\fR] [\fB-c \fIconfig_dir\fR] \fB-p\fR
+/* DESCRIPTION
+/*	The \fBpostqueue\fR(1) command implements the Postfix user interface
+/*	for queue management. It implements operations that are
+/*	traditionally available via the \fBsendmail\fR(1) command.
+/*	See the \fBpostsuper\fR(1) command for queue operations
+/*	that require super-user privileges such as deleting a message
+/*	from the queue or changing the status of a message.
+/*
+/*	The following options are recognized:
+/* .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-f\fR
+/*	Flush the queue: attempt to deliver all queued mail.
+/*
+/*	This option implements the traditional "\fBsendmail -q\fR" command,
+/*	by contacting the Postfix \fBqmgr\fR(8) daemon.
+/*
+/*	Warning: flushing undeliverable mail frequently will result in
+/*	poor delivery performance of all other mail.
+/* .IP "\fB-i \fIqueue_id\fR"
+/*	Schedule immediate delivery of deferred mail with the
+/*	specified queue ID.
+/*
+/*	This option implements the traditional \fBsendmail -qI\fR
+/*	command, by contacting the \fBflush\fR(8) server.
+/*
+/*	This feature is available with Postfix version 2.4 and later.
+/* .IP "\fB-j\fR"
+/*	Produce a queue listing in JSON format, based on output
+/*	from the showq(8) daemon.  The result is a stream of zero
+/*	or more JSON objects, one per queue file.  Each object is
+/*	followed by a newline character to support simple streaming
+/*	parsers. See "\fBJSON OBJECT FORMAT\fR" below for details.
+/*
+/*	This feature is available in Postfix 3.1 and later.
+/* .IP \fB-p\fR
+/*	Produce a traditional sendmail-style queue listing.
+/*	This option implements the traditional \fBmailq\fR command,
+/*	by contacting the Postfix \fBshowq\fR(8) daemon.
+/*
+/*	Each queue entry shows the queue file ID, message
+/*	size, arrival time, sender, and the recipients that still need to
+/*	be delivered.  If mail could not be delivered upon the last attempt,
+/*	the reason for failure is shown. The queue ID string
+/*	is followed by an optional status character:
+/* .RS
+/* .IP \fB*\fR
+/*	The message is in the \fBactive\fR queue, i.e. the message is
+/*	selected for delivery.
+/* .IP \fB!\fR
+/*	The message is in the \fBhold\fR queue, i.e. no further delivery
+/*	attempt will be made until the mail is taken off hold.
+/* .RE
+/* .IP "\fB-s \fIsite\fR"
+/*	Schedule immediate delivery of all mail that is queued for the named
+/*	\fIsite\fR. A numerical site must be specified as a valid RFC 5321
+/*	address literal enclosed in [], just like in email addresses.
+/*	The site must be eligible for the "fast flush" service.
+/*	See \fBflush\fR(8) for more information about the "fast flush"
+/*	service.
+/*
+/*	This option implements the traditional "\fBsendmail -qR\fIsite\fR"
+/*	command, by contacting the Postfix \fBflush\fR(8) daemon.
+/* .IP \fB-v\fR
+/*	Enable verbose logging for debugging purposes. Multiple \fB-v\fR
+/*	options make the software increasingly verbose. As of Postfix 2.3,
+/*	this option is available for the super-user only.
+/* JSON OBJECT FORMAT
+/* .ad
+/* .fi
+/*	Each JSON object represents one queue file; it is emitted
+/*	as a single text line followed by a newline character.
+/*
+/*	Object members have string values unless indicated otherwise.
+/*	Programs should ignore object members that are not listed
+/*	here; the list of members is expected to grow over time.
+/* .IP \fBqueue_name\fR
+/*	The name of the queue where the message was found.  Note
+/*	that the contents of the mail queue may change while it is
+/*	being listed; some messages may appear more than once, and
+/*	some messages may be missed.
+/* .IP \fBqueue_id\fR
+/*	The queue file name. The queue_id may be reused within a
+/*	Postfix instance unless "enable_long_queue_ids = true" and
+/*	time is monotonic.  Even then, the queue_id is not expected
+/*	to be unique between different Postfix instances.  Management
+/*	tools that require a unique name should combine the queue_id
+/*	with the myhostname setting of the Postfix instance.
+/* .IP \fBarrival_time\fR
+/*	The number of seconds since the start of the UNIX epoch.
+/* .IP \fBmessage_size\fR
+/*	The number of bytes in the message header and body. This
+/*	number does not include message envelope information. It
+/*	is approximately equal to the number of bytes that would
+/*	be transmitted via SMTP including the <CR><LF> line endings.
+/* .IP \fBsender\fR
+/*	The envelope sender address.
+/* .IP \fBrecipients\fR
+/*	An array containing zero or more objects with members:
+/* .RS
+/* .IP \fBaddress\fR
+/*	One recipient address.
+/* .IP \fBdelay_reason\fR
+/*	If present, the reason for delayed delivery.  Delayed
+/*	recipients may have no delay reason, for example, while
+/*	delivery is in progress, or after the system was stopped
+/*	before it could record the reason.
+/* .RE
+/* SECURITY
+/* .ad
+/* .fi
+/*	This program is designed to run with set-group ID privileges, so
+/*	that it can connect to Postfix daemon processes.
+/* STANDARDS
+/*	RFC 7159 (JSON notation)
+/* DIAGNOSTICS
+/*	Problems are logged to \fBsyslogd\fR(8) or \fBpostlogd\fR(8),
+/*	and to the standard error stream.
+/* ENVIRONMENT
+/* .ad
+/* .fi
+/* .IP MAIL_CONFIG
+/*	Directory with the \fBmain.cf\fR file. In order to avoid exploitation
+/*	of set-group ID privileges, a non-standard directory is allowed only
+/*	if:
+/* .RS
+/* .IP \(bu
+/*	The name is listed in the standard \fBmain.cf\fR file with the
+/*	\fBalternate_config_directories\fR configuration parameter.
+/* .IP \(bu
+/*	The command is invoked by the super-user.
+/* .RE
+/* 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 "\fBalternate_config_directories (empty)\fR"
+/*	A list of non-default Postfix configuration directories that may
+/*	be specified with "-c config_directory" on the command line (in the
+/*	case of \fBsendmail\fR(1), with the "-C" option), or via the MAIL_CONFIG
+/*	environment parameter.
+/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
+/*	The default location of the Postfix main.cf and master.cf
+/*	configuration files.
+/* .IP "\fBcommand_directory (see 'postconf -d' output)\fR"
+/*	The location of all postfix administrative commands.
+/* .IP "\fBfast_flush_domains ($relay_domains)\fR"
+/*	Optional list of destinations that are eligible for per-destination
+/*	logfiles with mail that is queued to those destinations.
+/* .IP "\fBimport_environment (see 'postconf -d' output)\fR"
+/*	The list of environment parameters 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".
+/* .IP "\fBtrigger_timeout (10s)\fR"
+/*	The time limit for sending a trigger to a Postfix daemon (for
+/*	example, the \fBpickup\fR(8) or \fBqmgr\fR(8) daemon).
+/* .PP
+/*	Available in Postfix version 2.2 and later:
+/* .IP "\fBauthorized_flush_users (static:anyone)\fR"
+/*	List of users who are authorized to flush the queue.
+/* .IP "\fBauthorized_mailq_users (static:anyone)\fR"
+/*	List of users who are authorized to view the queue.
+/* FILES
+/*	/var/spool/postfix, mail queue
+/* SEE ALSO
+/*	qmgr(8), queue manager
+/*	showq(8), list mail queue
+/*	flush(8), fast flush service
+/*	sendmail(1), Sendmail-compatible user interface
+/*	postsuper(1), privileged queue operations
+/*	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
+/*	ETRN_README, Postfix ETRN howto
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* HISTORY
+/* .ad
+/* .fi
+/*	The postqueue command was introduced with Postfix version 1.1.
+/* 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 <string.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sysexits.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include <msg.h>
+#include <mymalloc.h>
+#include <clean_env.h>
+#include <vstream.h>
+#include <msg_vstream.h>
+#include <argv.h>
+#include <safe.h>
+#include <connect.h>
+#include <valid_hostname.h>
+#include <warn_stat.h>
+#include <events.h>
+#include <stringops.h>
+
+/* Global library. */
+
+#include <mail_proto.h>
+#include <mail_params.h>
+#include <mail_version.h>
+#include <mail_conf.h>
+#include <mail_task.h>
+#include <mail_run.h>
+#include <mail_flush.h>
+#include <mail_queue.h>
+#include <flush_clnt.h>
+#include <smtp_stream.h>
+#include <user_acl.h>
+#include <valid_mailhost_addr.h>
+#include <mail_dict.h>
+#include <mail_parm_split.h>
+#include <maillog_client.h>
+
+/* Application-specific. */
+
+#include <postqueue.h>
+
+ /*
+  * WARNING WARNING WARNING
+  * 
+  * This software is designed to run set-gid. In order to avoid exploitation of
+  * privilege, this software should not run any external commands, nor should
+  * it take any information from the user, unless that information can be
+  * properly sanitized. To get an idea of how much information a process can
+  * inherit from a potentially hostile user, examine all the members of the
+  * process structure (typically, in /usr/include/sys/proc.h): the current
+  * directory, open files, timers, signals, environment, command line, umask,
+  * and so on.
+  */
+
+ /*
+  * Modes of operation.
+  * 
+  * XXX To support flush by recipient domain, or for destinations that have no
+  * mapping to logfile, the server has to defend against resource exhaustion
+  * attacks. A malicious user could fork off a postqueue client that starts
+  * an expensive requests and then kills the client immediately; this way she
+  * could create a high Postfix load on the system without ever exceeding her
+  * own per-user process limit. To prevent this, either the server needs to
+  * establish frequent proof of client liveliness with challenge/response, or
+  * the client needs to restrict expensive requests to privileged users only.
+  * 
+  * We don't have this problem with queue listings. The showq server detects an
+  * EPIPE error after reporting a few queue entries.
+  */
+#define PQ_MODE_DEFAULT		0	/* noop */
+#define PQ_MODE_MAILQ_LIST	1	/* list mail queue */
+#define PQ_MODE_FLUSH_QUEUE	2	/* flush queue */
+#define PQ_MODE_FLUSH_SITE	3	/* flush site */
+#define PQ_MODE_FLUSH_FILE	4	/* flush message */
+#define PQ_MODE_JSON_LIST	5	/* JSON-format queue listing */
+
+ /*
+  * Silly little macros (SLMs).
+  */
+#define STR	vstring_str
+
+ /*
+  * Queue manipulation access lists.
+  */
+char   *var_flush_acl;
+char   *var_showq_acl;
+
+static const CONFIG_STR_TABLE str_table[] = {
+    VAR_FLUSH_ACL, DEF_FLUSH_ACL, &var_flush_acl, 0, 0,
+    VAR_SHOWQ_ACL, DEF_SHOWQ_ACL, &var_showq_acl, 0, 0,
+    0,
+};
+
+/* show_queue - show queue status */
+
+static void show_queue(int mode)
+{
+    const char *errstr;
+    VSTREAM *showq;
+    int     n;
+    uid_t   uid = getuid();
+
+    if (uid != 0 && uid != var_owner_uid
+	&& (errstr = check_user_acl_byuid(VAR_SHOWQ_ACL, var_showq_acl,
+					  uid)) != 0)
+	msg_fatal_status(EX_NOPERM,
+		       "User %s(%ld) is not allowed to view the mail queue",
+			 errstr, (long) uid);
+
+    /*
+     * Connect to the show queue service.
+     */
+    if ((showq = mail_connect(MAIL_CLASS_PUBLIC, var_showq_service, BLOCKING)) != 0) {
+	switch (mode) {
+	case PQ_MODE_MAILQ_LIST:
+	    showq_compat(showq);
+	    break;
+	case PQ_MODE_JSON_LIST:
+	    showq_json(showq);
+	    break;
+	default:
+	    msg_panic("show_queue: unknown mode %d", mode);
+	}
+	if (vstream_fclose(showq))
+	    msg_warn("close: %m");
+    }
+
+    /*
+     * Don't assume that the mail system is down when the user has
+     * insufficient permission to access the showq socket.
+     */
+    else if (errno == EACCES) {
+	msg_fatal_status(EX_SOFTWARE,
+			 "Connect to the %s %s service: %m",
+			 var_mail_name, var_showq_service);
+    }
+
+    /*
+     * When the mail system is down, the superuser can still access the queue
+     * directly. Just run the showq program in stand-alone mode.
+     */
+    else if (geteuid() == 0) {
+	char   *showq_path;
+	ARGV   *argv;
+	int     stat;
+
+	msg_warn("Mail system is down -- accessing queue directly");
+	showq_path = concatenate(var_daemon_dir, "/", var_showq_service,
+				 (char *) 0);
+	argv = argv_alloc(6);
+	argv_add(argv, showq_path, "-u", "-S", (char *) 0);
+	for (n = 0; n < msg_verbose; n++)
+	    argv_add(argv, "-v", (char *) 0);
+	argv_terminate(argv);
+	if ((showq = vstream_popen(O_RDONLY,
+				   CA_VSTREAM_POPEN_ARGV(argv->argv),
+				   CA_VSTREAM_POPEN_END)) == 0) {
+	    stat = -1;
+	} else {
+	    switch (mode) {
+	    case PQ_MODE_MAILQ_LIST:
+		showq_compat(showq);
+		break;
+	    case PQ_MODE_JSON_LIST:
+		showq_json(showq);
+		break;
+	    default:
+		msg_panic("show_queue: unknown mode %d", mode);
+	    }
+	    stat = vstream_pclose(showq);
+	}
+	argv_free(argv);
+	if (stat != 0)
+	    msg_fatal_status(stat < 0 ? EX_OSERR : EX_SOFTWARE,
+			     "Error running %s", showq_path);
+	myfree(showq_path);
+    }
+
+    /*
+     * When the mail system is down, unprivileged users are stuck, because by
+     * design the mail system contains no set_uid programs. The only way for
+     * an unprivileged user to cross protection boundaries is to talk to the
+     * showq daemon.
+     */
+    else {
+	msg_fatal_status(EX_UNAVAILABLE,
+			 "Queue report unavailable - mail system is down");
+    }
+}
+
+/* flush_queue - force delivery */
+
+static void flush_queue(void)
+{
+    const char *errstr;
+    uid_t   uid = getuid();
+
+    if (uid != 0 && uid != var_owner_uid
+	&& (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl,
+					  uid)) != 0)
+	msg_fatal_status(EX_NOPERM,
+		      "User %s(%ld) is not allowed to flush the mail queue",
+			 errstr, (long) uid);
+
+    /*
+     * Trigger the flush queue service.
+     */
+    if (mail_flush_deferred() < 0)
+	msg_fatal_status(EX_UNAVAILABLE,
+			 "Cannot flush mail queue - mail system is down");
+    if (mail_flush_maildrop() < 0)
+	msg_fatal_status(EX_UNAVAILABLE,
+			 "Cannot flush mail queue - mail system is down");
+    event_drain(2);
+}
+
+/* flush_site - flush mail for site */
+
+static void flush_site(const char *site)
+{
+    int     status;
+    const char *errstr;
+    uid_t   uid = getuid();
+
+    if (uid != 0 && uid != var_owner_uid
+	&& (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl,
+					  uid)) != 0)
+	msg_fatal_status(EX_NOPERM,
+		      "User %s(%ld) is not allowed to flush the mail queue",
+			 errstr, (long) uid);
+
+    flush_init();
+
+    switch (status = flush_send_site(site)) {
+    case FLUSH_STAT_OK:
+	exit(0);
+    case FLUSH_STAT_BAD:
+	msg_fatal_status(EX_USAGE, "Invalid request: \"%s\"", site);
+    case FLUSH_STAT_FAIL:
+	msg_fatal_status(EX_UNAVAILABLE,
+			 "Cannot flush mail queue - mail system is down");
+    case FLUSH_STAT_DENY:
+	msg_fatal_status(EX_UNAVAILABLE,
+		   "Flush service is not configured for destination \"%s\"",
+			 site);
+    default:
+	msg_fatal_status(EX_SOFTWARE,
+			 "Unknown flush server reply status %d", status);
+    }
+}
+
+/* flush_file - flush mail with specific queue ID */
+
+static void flush_file(const char *queue_id)
+{
+    int     status;
+    const char *errstr;
+    uid_t   uid = getuid();
+
+    if (uid != 0 && uid != var_owner_uid
+	&& (errstr = check_user_acl_byuid(VAR_FLUSH_ACL, var_flush_acl,
+					  uid)) != 0)
+	msg_fatal_status(EX_NOPERM,
+		      "User %s(%ld) is not allowed to flush the mail queue",
+			 errstr, (long) uid);
+
+    switch (status = flush_send_file(queue_id)) {
+    case FLUSH_STAT_OK:
+	exit(0);
+    case FLUSH_STAT_BAD:
+	msg_fatal_status(EX_USAGE, "Invalid request: \"%s\"", queue_id);
+    case FLUSH_STAT_FAIL:
+	msg_fatal_status(EX_UNAVAILABLE,
+			 "Cannot flush mail queue - mail system is down");
+    default:
+	msg_fatal_status(EX_SOFTWARE,
+			 "Unexpected flush server reply status %d", status);
+    }
+}
+
+/* unavailable - sanitize exit status from library run-time errors */
+
+static void unavailable(void)
+{
+    exit(EX_UNAVAILABLE);
+}
+
+/* usage - scream and die */
+
+static NORETURN usage(void)
+{
+    msg_fatal_status(EX_USAGE, "usage: postqueue -f | postqueue -i queueid | postqueue -j | postqueue -p | postqueue -s site");
+}
+
+MAIL_VERSION_STAMP_DECLARE;
+
+/* main - the main program */
+
+int     main(int argc, char **argv)
+{
+    struct stat st;
+    int     c;
+    int     fd;
+    int     mode = PQ_MODE_DEFAULT;
+    char   *site_to_flush = 0;
+    char   *id_to_flush = 0;
+    ARGV   *import_env;
+    int     bad_site;
+
+    /*
+     * 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_status(EX_UNAVAILABLE, "open /dev/null: %m");
+
+    /*
+     * Initialize. Set up logging. Read the global configuration file after
+     * parsing command-line arguments. Censor the process name: it is
+     * provided by the user.
+     */
+    argv[0] = "postqueue";
+    msg_vstream_init(argv[0], VSTREAM_ERR);
+    msg_cleanup(unavailable);
+    maillog_client_init(mail_task("postqueue"), MAILLOG_CLIENT_FLAG_NONE);
+    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;
+
+    /*
+     * Parse JCL. This program is set-gid and must sanitize all command-line
+     * parameters. The configuration directory argument is validated by the
+     * mail configuration read routine. Don't do complex things until we have
+     * completed initializations.
+     */
+    while ((c = GETOPT(argc, argv, "c:fi:jps:v")) > 0) {
+	switch (c) {
+	case 'c':				/* non-default configuration */
+	    if (setenv(CONF_ENV_PATH, optarg, 1) < 0)
+		msg_fatal_status(EX_UNAVAILABLE, "out of memory");
+	    break;
+	case 'f':				/* flush queue */
+	    if (mode != PQ_MODE_DEFAULT)
+		usage();
+	    mode = PQ_MODE_FLUSH_QUEUE;
+	    break;
+	case 'i':				/* flush queue file */
+	    if (mode != PQ_MODE_DEFAULT)
+		usage();
+	    mode = PQ_MODE_FLUSH_FILE;
+	    id_to_flush = optarg;
+	    break;
+	case 'j':
+	    if (mode != PQ_MODE_DEFAULT)
+		usage();
+	    mode = PQ_MODE_JSON_LIST;
+	    break;
+	case 'p':				/* traditional mailq */
+	    if (mode != PQ_MODE_DEFAULT)
+		usage();
+	    mode = PQ_MODE_MAILQ_LIST;
+	    break;
+	case 's':				/* flush site */
+	    if (mode != PQ_MODE_DEFAULT)
+		usage();
+	    mode = PQ_MODE_FLUSH_SITE;
+	    site_to_flush = optarg;
+	    break;
+	case 'v':
+	    if (geteuid() == 0)
+		msg_verbose++;
+	    break;
+	default:
+	    usage();
+	}
+    }
+    if (argc > optind)
+	usage();
+
+    /*
+     * Further initialization...
+     */
+    mail_conf_read();
+    /* Re-evaluate mail_task() after reading main.cf. */
+    maillog_client_init(mail_task("postqueue"), MAILLOG_CLIENT_FLAG_NONE);
+    mail_dict_init();				/* proxy, sql, ldap */
+    get_mail_conf_str_table(str_table);
+
+    /*
+     * This program is designed to be set-gid, which makes it a potential
+     * target for attack. Strip and optionally override the process
+     * environment so that we don't have to trust the C library.
+     */
+    import_env = mail_parm_split(VAR_IMPORT_ENVIRON, var_import_environ);
+    clean_env(import_env->argv);
+    argv_free(import_env);
+
+    if (chdir(var_queue_dir))
+	msg_fatal_status(EX_UNAVAILABLE, "chdir %s: %m", var_queue_dir);
+
+    signal(SIGPIPE, SIG_IGN);
+
+    /* End of initializations. */
+
+    /*
+     * Further input validation.
+     */
+    if (site_to_flush != 0) {
+	bad_site = 0;
+	if (*site_to_flush == '[') {
+	    bad_site = !valid_mailhost_literal(site_to_flush, DONT_GRIPE);
+	} else {
+	    bad_site = !valid_hostname(site_to_flush, DONT_GRIPE);
+	}
+	if (bad_site)
+	    msg_fatal_status(EX_USAGE,
+	      "Cannot flush mail queue - invalid destination: \"%.100s%s\"",
+		   site_to_flush, strlen(site_to_flush) > 100 ? "..." : "");
+    }
+    if (id_to_flush != 0) {
+	if (!mail_queue_id_ok(id_to_flush))
+	    msg_fatal_status(EX_USAGE,
+		       "Cannot flush queue ID - invalid name: \"%.100s%s\"",
+		       id_to_flush, strlen(id_to_flush) > 100 ? "..." : "");
+    }
+
+    /*
+     * Start processing.
+     */
+    switch (mode) {
+    default:
+	msg_panic("unknown operation mode: %d", mode);
+	/* NOTREACHED */
+    case PQ_MODE_MAILQ_LIST:
+    case PQ_MODE_JSON_LIST:
+	show_queue(mode);
+	exit(0);
+	break;
+    case PQ_MODE_FLUSH_SITE:
+	flush_site(site_to_flush);
+	exit(0);
+	break;
+    case PQ_MODE_FLUSH_FILE:
+	flush_file(id_to_flush);
+	exit(0);
+	break;
+    case PQ_MODE_FLUSH_QUEUE:
+	flush_queue();
+	exit(0);
+	break;
+    case PQ_MODE_DEFAULT:
+	usage();
+	/* NOTREACHED */
+    }
+}
diff --git a/src/postqueue/postqueue.h b/src/postqueue/postqueue.h
new file mode 100644
index 0000000..b1b7d27
--- /dev/null
+++ b/src/postqueue/postqueue.h
@@ -0,0 +1,35 @@
+/*++
+/* NAME
+/*	postqueue 5h
+/* SUMMARY
+/*	postqueue internal interfaces
+/* SYNOPSIS
+/*	#include <postqueue.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * showq_compat.c
+  */
+extern void showq_compat(VSTREAM *);
+
+ /*
+  * showq_json.c
+  */
+extern void showq_json(VSTREAM *);
+
+/* 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
+/*--*/
diff --git a/src/postqueue/showq_compat.c b/src/postqueue/showq_compat.c
new file mode 100644
index 0000000..c1868e1
--- /dev/null
+++ b/src/postqueue/showq_compat.c
@@ -0,0 +1,215 @@
+/*++
+/* NAME
+/*	showq_compat 8
+/* SUMMARY
+/*	Sendmail mailq compatibitily adapter
+/* SYNOPSIS
+/*	void	showq_compat(
+/*	VSTREAM	*showq)
+/* DESCRIPTION
+/*	This function converts a record stream from the showq(8)
+/*	daemon to of an approximation of Sendmail mailq command
+/*	output.
+/* DIAGNOSTICS
+/*	Fatal errors: out of memory, malformed showq(8) daemon output.
+/* 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 <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <string.h>
+#include <sysexits.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include <vstring.h>
+#include <vstream.h>
+#include <stringops.h>
+#include <mymalloc.h>
+#include <msg.h>
+
+/* Global library. */
+
+#include <mail_proto.h>
+#include <mail_queue.h>
+#include <mail_date.h>
+#include <mail_params.h>
+
+/* Application-specific. */
+
+#include <postqueue.h>
+
+ /*
+  * The enable_long_queue_ids parameter determines the output format.
+  * 
+  * The historical output format for short queue IDs (inode number and time in
+  * microseconds modulo 1) is not suitable for large inode numbers, but we
+  * won't change it to avoid breaking compatibility with programs that parse
+  * this output.
+  */
+#define S_STRING_FORMAT	"%-11s %7s %-20s %s\n"
+#define S_SENDER_FORMAT	"%-11s %7ld %20.20s %s\n"
+#define S_HEADINGS	"-Queue ID-", "--Size--", \
+			    "----Arrival Time----", "-Sender/Recipient-------"
+
+#define L_STRING_FORMAT	"%-17s %8s %-19s %s\n"
+#define L_SENDER_FORMAT	"%-17s %8ld %19.19s %s\n"
+#define L_HEADINGS	"----Queue ID-----", "--Size--", \
+			    "---Arrival Time----", "--Sender/Recipient------"
+
+#define STR(x)	vstring_str(x)
+
+/* showq_message - report status for one message */
+
+static unsigned long showq_message(VSTREAM *showq_stream)
+{
+    static VSTRING *queue_name = 0;
+    static VSTRING *queue_id = 0;
+    static VSTRING *id_status = 0;
+    static VSTRING *addr = 0;
+    static VSTRING *why = 0;
+    long    arrival_time;
+    long    message_size;
+    int     message_status;
+    char   *saved_reason = mystrdup("");
+    const char *show_reason;
+    int     padding;
+    int     showq_status;
+    time_t  time_t_arrival_time;
+
+    /*
+     * One-time initialization.
+     */
+    if (queue_name == 0) {
+	queue_name = vstring_alloc(100);
+	queue_id = vstring_alloc(100);
+	id_status = vstring_alloc(100);
+	addr = vstring_alloc(100);
+	why = vstring_alloc(100);
+    }
+
+    /*
+     * Read the message properties and sender address.
+     */
+    if (attr_scan(showq_stream, ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUE, queue_name),
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUEID, queue_id),
+		  RECV_ATTR_LONG(MAIL_ATTR_TIME, &arrival_time),
+		  RECV_ATTR_LONG(MAIL_ATTR_SIZE, &message_size),
+		  RECV_ATTR_STR(MAIL_ATTR_SENDER, addr),
+		  ATTR_TYPE_END) != 5)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+
+    /*
+     * Decorate queue file names in specific states, then print the result
+     * left-aligned, followed by other status info and the sender address
+     * which is already in externalized RFC 5321 form.
+     */
+    message_status = (strcmp(STR(queue_name), MAIL_QUEUE_ACTIVE) == 0 ? '*' :
+		 strcmp(STR(queue_name), MAIL_QUEUE_HOLD) == 0 ? '!' : ' ');
+    vstring_sprintf(id_status, "%s%c", STR(queue_id), message_status);
+    time_t_arrival_time = arrival_time;
+    vstream_printf(var_long_queue_ids ?
+		   L_SENDER_FORMAT : S_SENDER_FORMAT, STR(id_status),
+		   message_size, asctime(localtime(&time_t_arrival_time)),
+		   STR(addr));
+
+    /*
+     * Read zero or more (recipient, reason) pair(s) until attr_scan_more()
+     * consumes a terminator. If the showq daemon messes up, don't try to
+     * resynchronize.
+     */
+    while ((showq_status = attr_scan_more(showq_stream)) > 0) {
+	if (attr_scan(showq_stream, ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
+		      RECV_ATTR_STR(MAIL_ATTR_RECIP, addr),
+		      RECV_ATTR_STR(MAIL_ATTR_WHY, why),
+		      ATTR_TYPE_END) != 2)
+	    msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+
+	/*
+	 * Don't output a "(reason)" line when no recipient has a reason, or
+	 * when the previous recipient has the same (non)reason as the
+	 * current recipient. Do output a "(reason unavailable)" when the
+	 * previous recipient has a reason, and the current recipient has
+	 * none.
+	 */
+	if (strcmp(saved_reason, STR(why)) != 0) {
+	    myfree(saved_reason);
+	    saved_reason = mystrdup(STR(why));
+	    show_reason = *saved_reason ? saved_reason : "reason unavailable";
+	    if ((padding = 76 - (int) strlen(show_reason)) < 0)
+		padding = 0;
+	    vstream_printf("%*s(%s)\n", padding, "", show_reason);
+	}
+	vstream_printf(var_long_queue_ids ?
+		       L_STRING_FORMAT : S_STRING_FORMAT,
+		       "", "", "", STR(addr));
+    }
+    if (showq_status < 0)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+    myfree(saved_reason);
+    return (message_size);
+}
+
+/* showq_compat - legacy mailq-style output adapter */
+
+void    showq_compat(VSTREAM *showq_stream)
+{
+    unsigned long file_count = 0;
+    unsigned long queue_size = 0;
+    int     showq_status;
+
+    /*
+     * Process zero or more queue file objects until attr_scan_more()
+     * consumes a terminator.
+     */
+    while ((showq_status = attr_scan_more(showq_stream)) > 0) {
+	if (file_count > 0) {
+	    vstream_printf("\n");
+	} else if (var_long_queue_ids) {
+	    vstream_printf(L_STRING_FORMAT, L_HEADINGS);
+	} else {
+	    vstream_printf(S_STRING_FORMAT, S_HEADINGS);
+	}
+	queue_size += showq_message(showq_stream);
+	file_count++;
+	if (vstream_fflush(VSTREAM_OUT)) {
+	    if (errno != EPIPE)
+		msg_fatal_status(EX_IOERR, "output write error: %m");
+	    return;
+	}
+    }
+    if (showq_status < 0)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+
+    /*
+     * Print the queue summary.
+     */
+    if (file_count == 0)
+	vstream_printf("Mail queue is empty\n");
+    else {
+	vstream_printf("\n-- %lu Kbytes in %lu Request%s.\n",
+		       queue_size / 1024, file_count,
+		       file_count == 1 ? "" : "s");
+    }
+    if (vstream_fflush(VSTREAM_OUT) && errno != EPIPE)
+	msg_fatal_status(EX_IOERR, "output write error: %m");
+}
diff --git a/src/postqueue/showq_json.c b/src/postqueue/showq_json.c
new file mode 100644
index 0000000..67fbada
--- /dev/null
+++ b/src/postqueue/showq_json.c
@@ -0,0 +1,216 @@
+/*++
+/* NAME
+/*	showq_json 8
+/* SUMMARY
+/*	JSON queue status formatter
+/* SYNOPSIS
+/*	void	showq_json(
+/*	VSTREAM	*showq)
+/* DESCRIPTION
+/*	This function converts showq(8) daemon output to JSON format.
+/* DIAGNOSTICS
+/*	Fatal errors: out of memory, malformed showq(8) daemon output.
+/* 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 <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <sysexits.h>
+#include <ctype.h>
+#include <errno.h>
+
+/* Utility library. */
+
+#include <vstring.h>
+#include <vstream.h>
+#include <stringops.h>
+#include <mymalloc.h>
+#include <msg.h>
+
+/* Global library. */
+
+#include <mail_proto.h>
+#include <mail_queue.h>
+#include <mail_date.h>
+#include <mail_params.h>
+
+/* Application-specific. */
+
+#include <postqueue.h>
+
+#define STR(x)	vstring_str(x)
+#define LEN(x)	VSTRING_LEN(x)
+
+/* json_quote - quote JSON string */
+
+static char *json_quote(VSTRING *result, const char *text)
+{
+    unsigned char *cp;
+    int     ch;
+
+    /*
+     * We use short escape sequences for common control characters. Note that
+     * RFC 4627 allows "/" (0x2F) to be sent without quoting. Differences
+     * with RFC 4627: we send DEL (0x7f) as \u007F; the result remains RFC
+     * 4627 complaint.
+     */
+    VSTRING_RESET(result);
+    for (cp = (unsigned char *) text; (ch = *cp) != 0; cp++) {
+	if (UNEXPECTED(ISCNTRL(ch))) {
+	    switch (ch) {
+	    case '\b':
+		VSTRING_ADDCH(result, '\\');
+		VSTRING_ADDCH(result, 'b');
+		break;
+	    case '\f':
+		VSTRING_ADDCH(result, '\\');
+		VSTRING_ADDCH(result, 'f');
+		break;
+	    case '\n':
+		VSTRING_ADDCH(result, '\\');
+		VSTRING_ADDCH(result, 'n');
+		break;
+	    case '\r':
+		VSTRING_ADDCH(result, '\\');
+		VSTRING_ADDCH(result, 'r');
+		break;
+	    case '\t':
+		VSTRING_ADDCH(result, '\\');
+		VSTRING_ADDCH(result, 't');
+		break;
+	    default:
+		vstring_sprintf(result, "\\u%04X", ch);
+		break;
+	    }
+	} else {
+	    switch (ch) {
+	    case '\\':
+	    case '"':
+		VSTRING_ADDCH(result, '\\');
+		/* FALLTHROUGH */
+	    default:
+		VSTRING_ADDCH(result, ch);
+		break;
+	    }
+	}
+    }
+    VSTRING_TERMINATE(result);
+
+    /*
+     * Force the result to be UTF-8 (with SMTPUTF8 enabled) or ASCII (with
+     * SMTPUTF8 disabled).
+     */
+    printable(STR(result), '?');
+    return (STR(result));
+}
+
+/* json_message - report status for one message */
+
+static void format_json(VSTREAM *showq_stream)
+{
+    static VSTRING *queue_name = 0;
+    static VSTRING *queue_id = 0;
+    static VSTRING *addr = 0;
+    static VSTRING *why = 0;
+    static VSTRING *quote_buf = 0;
+    long    arrival_time;
+    long    message_size;
+    int     showq_status;
+    int     rcpt_count = 0;
+
+    /*
+     * One-time initialization.
+     */
+    if (queue_name == 0) {
+	queue_name = vstring_alloc(100);
+	queue_id = vstring_alloc(100);
+	addr = vstring_alloc(100);
+	why = vstring_alloc(100);
+	quote_buf = vstring_alloc(100);
+    }
+
+    /*
+     * Read the message properties and sender address.
+     */
+    if (attr_scan(showq_stream, ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUE, queue_name),
+		  RECV_ATTR_STR(MAIL_ATTR_QUEUEID, queue_id),
+		  RECV_ATTR_LONG(MAIL_ATTR_TIME, &arrival_time),
+		  RECV_ATTR_LONG(MAIL_ATTR_SIZE, &message_size),
+		  RECV_ATTR_STR(MAIL_ATTR_SENDER, addr),
+		  ATTR_TYPE_END) != 5)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+    vstream_printf("{");
+    vstream_printf("\"queue_name\": \"%s\", ",
+		   json_quote(quote_buf, STR(queue_name)));
+    vstream_printf("\"queue_id\": \"%s\", ",
+		   json_quote(quote_buf, STR(queue_id)));
+    vstream_printf("\"arrival_time\": %ld, ", arrival_time);
+    vstream_printf("\"message_size\": %ld, ", message_size);
+    vstream_printf("\"sender\": \"%s\", ",
+		   json_quote(quote_buf, STR(addr)));
+
+    /*
+     * Read zero or more (recipient, reason) pair(s) until attr_scan_more()
+     * consumes a terminator. If the showq daemon messes up, don't try to
+     * resynchronize.
+     */
+    vstream_printf("\"recipients\": [");
+    for (rcpt_count = 0; (showq_status = attr_scan_more(showq_stream)) > 0; rcpt_count++) {
+	if (rcpt_count > 0)
+	    vstream_printf(", ");
+	vstream_printf("{");
+	if (attr_scan(showq_stream, ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
+		      RECV_ATTR_STR(MAIL_ATTR_RECIP, addr),
+		      RECV_ATTR_STR(MAIL_ATTR_WHY, why),
+		      ATTR_TYPE_END) != 2)
+	    msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+	vstream_printf("\"address\": \"%s\"",
+		       json_quote(quote_buf, STR(addr)));
+	if (LEN(why) > 0)
+	    vstream_printf(", \"delay_reason\": \"%s\"",
+			   json_quote(quote_buf, STR(why)));
+	vstream_printf("}");
+    }
+    vstream_printf("]");
+    if (showq_status < 0)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+    vstream_printf("}\n");
+    if (vstream_fflush(VSTREAM_OUT) && errno != EPIPE)
+	msg_fatal_status(EX_IOERR, "output write error: %m");
+}
+
+/* showq_json - streaming JSON-format output adapter */
+
+void    showq_json(VSTREAM *showq_stream)
+{
+    int     showq_status;
+
+    /*
+     * Emit zero or more queue file objects until attr_scan_more() consumes a
+     * terminator.
+     */
+    while ((showq_status = attr_scan_more(showq_stream)) > 0
+	   && vstream_ferror(VSTREAM_OUT) == 0) {
+	format_json(showq_stream);
+    }
+    if (showq_status < 0)
+	msg_fatal_status(EX_SOFTWARE, "malformed showq server response");
+}