path: root/src/pipe/pipe.c

/*++
/* NAME
/*	pipe 8
/* SUMMARY
/*	Postfix delivery to external command
/* SYNOPSIS
/*	\fBpipe\fR [generic Postfix daemon options] command_attributes...
/* DESCRIPTION
/*	The \fBpipe\fR(8) daemon processes requests from the Postfix queue
/*	manager to deliver messages to external commands.
/*	This program expects to be run from the \fBmaster\fR(8) process
/*	manager.
/*
/*	Message attributes such as sender address, recipient address and
/*	next-hop host name can be specified as command-line macros that are
/*	expanded before the external command is executed.
/*
/*	The \fBpipe\fR(8) daemon updates queue files and marks recipients
/*	as finished, or it informs the queue manager that delivery should
/*	be tried again at a later time. Delivery status reports are sent
/*	to the \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemon as
/*	appropriate.
/* SINGLE-RECIPIENT DELIVERY
/* .ad
/* .fi
/*	Some destinations cannot handle more than one recipient per
/*	delivery request. Examples are pagers or fax machines.
/*	In addition, multi-recipient delivery is undesirable when
/*	prepending a \fBDelivered-to:\fR or \fBX-Original-To:\fR
/*	message header.
/*
/*	To prevent Postfix from sending multiple recipients per delivery
/*	request, specify
/* .sp
/* .nf
/*	    \fItransport\fB_destination_recipient_limit = 1\fR
/* .fi
/*
/*	in the Postfix \fBmain.cf\fR file, where \fItransport\fR
/*	is the name in the first column of the Postfix \fBmaster.cf\fR
/*	entry for the pipe-based delivery transport.
/* COMMAND ATTRIBUTE SYNTAX
/* .ad
/* .fi
/*	The external command attributes are given in the \fBmaster.cf\fR
/*	file at the end of a service definition.  The syntax is as follows:
/* .IP "\fBchroot=\fIpathname\fR (optional)"
/*	Change the process root directory and working directory to
/*	the named directory. This happens before switching to the
/*	privileges specified with the \fBuser\fR attribute, and
/*	before executing the optional \fBdirectory=\fIpathname\fR
/*	directive. Delivery is deferred in case of failure.
/* .sp
/*	This feature is available as of Postfix 2.3.
/* .IP "\fBdirectory=\fIpathname\fR (optional)"
/*	Change to the named directory before executing the external command.
/*	The directory must be accessible for the user specified with the
/*	\fBuser\fR attribute (see below).
/*	The default working directory is \fB$queue_directory\fR.
/*	Delivery is deferred in case of failure.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP "\fBeol=\fIstring\fR (optional, default: \fB\en\fR)"
/*	The output record delimiter. Typically one would use either
/*	\fB\er\en\fR or \fB\en\fR. The usual C-style backslash escape
/*	sequences are recognized: \fB\ea \eb \ef \en \er \et \ev
/*	\e\fIddd\fR (up to three octal digits) and \fB\e\e\fR.
/* .IP "\fBflags=BDFORXhqu.>\fR (optional)"
/*	Optional message processing flags. By default, a message is
/*	copied unchanged.
/* .RS
/* .IP \fBB\fR
/*	Append a blank line at the end of each message. This is required
/*	by some mail user agents that recognize "\fBFrom \fR" lines only
/*	when preceded by a blank line.
/* .IP \fBD\fR
/*	Prepend a "\fBDelivered-To: \fIrecipient\fR" message header with the
/*	envelope recipient address. Note: for this to work, the
/*	\fItransport\fB_destination_recipient_limit\fR must be 1
/*	(see SINGLE-RECIPIENT DELIVERY above for details).
/* .sp
/*	The \fBD\fR flag also enforces loop detection (Postfix 2.5 and later):
/*	if a message already contains a \fBDelivered-To:\fR header
/*	with the same recipient address, then the message is
/*	returned as undeliverable. The address comparison is case
/*	insensitive.
/* .sp
/*	This feature is available as of Postfix 2.0.
/* .IP \fBF\fR
/*	Prepend a "\fBFrom \fIsender time_stamp\fR" envelope header to
/*	the message content.
/*	This is expected by, for example, \fBUUCP\fR software.
/* .IP \fBO\fR
/*	Prepend an "\fBX-Original-To: \fIrecipient\fR" message header
/*	with the recipient address as given to Postfix. Note: for this to
/*	work, the \fItransport\fB_destination_recipient_limit\fR must be 1
/*	(see SINGLE-RECIPIENT DELIVERY above for details).
/* .sp
/*	This feature is available as of Postfix 2.0.
/* .IP \fBR\fR
/*	Prepend a \fBReturn-Path:\fR message header with the envelope sender
/*	address.
/* .IP \fBX\fR
/*	Indicate that the external command performs final delivery.
/*	This flag affects the status reported in "success" DSN
/*	(delivery status notification) messages, and changes it
/*	from "relayed" into "delivered".
/* .sp
/*	This feature is available as of Postfix 2.5.
/* .IP \fBh\fR
/*	Fold the command-line \fB$original_recipient\fR and
/*	\fB$recipient\fR address domain part
/*	(text to the right of the right-most \fB@\fR character) to
/*	lower case; fold the entire command-line \fB$domain\fR and
/*	\fB$nexthop\fR host or domain information to lower case.
/*	This is recommended for delivery via \fBUUCP\fR.
/* .IP \fBq\fR
/*	Quote white space and other special characters in the command-line
/*	\fB$sender\fR, \fB$original_recipient\fR and \fB$recipient\fR
/*	address localparts (text to the
/*	left of the right-most \fB@\fR character), according to an 8-bit
/*	transparent version of RFC 822.
/*	This is recommended for delivery via \fBUUCP\fR or \fBBSMTP\fR.
/* .sp
/*	The result is compatible with the address parsing of command-line
/*	recipients by the Postfix \fBsendmail\fR(1) mail submission command.
/* .sp
/*	The \fBq\fR flag affects only entire addresses, not the partial
/*	address information from the \fB$user\fR, \fB$extension\fR or
/*	\fB$mailbox\fR command-line macros.
/* .IP \fBu\fR
/*	Fold the command-line \fB$original_recipient\fR and
/*	\fB$recipient\fR address localpart (text to
/*	the left of the right-most \fB@\fR character) to lower case.
/*	This is recommended for delivery via \fBUUCP\fR.
/* .IP \fB.\fR
/*	Prepend "\fB.\fR" to lines starting with "\fB.\fR". This is needed
/*	by, for example, \fBBSMTP\fR software.
/* .IP \fB>\fR
/*	Prepend "\fB>\fR" to lines starting with "\fBFrom \fR". This is expected
/*	by, for example, \fBUUCP\fR software.
/* .RE
/* .IP "\fBnull_sender\fR=\fIreplacement\fR (default: MAILER-DAEMON)"
/*	Replace the null sender address (typically used for delivery
/*	status notifications) with the specified text
/*	when expanding the \fB$sender\fR command-line macro, and
/*	when generating a From_ or Return-Path: message header.
/*
/*	If the null sender replacement text is a non-empty string
/*	then it is affected by the \fBq\fR flag for address quoting
/*	in command-line arguments.
/*
/*	The null sender replacement text may be empty; this form
/*	is recommended for content filters that feed mail back into
/*	Postfix. The empty sender address is not affected by the
/*	\fBq\fR flag for address quoting in command-line arguments.
/* .sp
/*	Caution: a null sender address is easily mis-parsed by
/*	naive software. For example, when the \fBpipe\fR(8) daemon
/*	executes a command such as:
/* .sp
/* .nf
/*	    \fIWrong\fR: command -f$sender -- $recipient
/* .fi
/* .IP
/*	the command will mis-parse the -f option value when the
/*	sender address is a null string.  For correct parsing,
/*	specify \fB$sender\fR as an argument by itself:
/* .sp
/* .nf
/*	    \fIRight\fR: command -f $sender -- $recipient
/* .fi
/* .IP
/*	This feature is available as of Postfix 2.3.
/* .IP "\fBsize\fR=\fIsize_limit\fR (optional)"
/*	Don't deliver messages that exceed this size limit (in
/*	bytes); return them to the sender instead.
/* .IP "\fBuser\fR=\fIusername\fR (required)"
/* .IP "\fBuser\fR=\fIusername\fR:\fIgroupname\fR"
/*	Execute the external command with the user ID and group ID of the
/*	specified \fIusername\fR.  The software refuses to execute
/*	commands with root privileges, or with the privileges of the
/*	mail system owner. If \fIgroupname\fR is specified, the
/*	corresponding group ID is used instead of the group ID of
/*	\fIusername\fR.
/* .IP "\fBargv\fR=\fIcommand\fR... (required)"
/*	The command to be executed. This must be specified as the
/*	last command attribute.
/*	The command is executed directly, i.e. without interpretation of
/*	shell meta characters by a shell command interpreter.
/* .sp
/*	Specify "{" and "}" around command arguments that contain
/*	whitespace (Postfix 3.0 and later). Whitespace
/*	after the opening "{" and before the closing "}" is ignored.
/* .sp
/*	In the command argument vector, the following macros are recognized
/*	and replaced with corresponding information from the Postfix queue
/*	manager delivery request.
/* .sp
/*	In addition to the form ${\fIname\fR}, the forms $\fIname\fR and
/*	the deprecated form $(\fIname\fR) are also recognized.
/*	Specify \fB$$\fR where a single \fB$\fR is wanted.
/* .RS
/* .IP \fB${client_address}\fR
/*	This macro expands to the remote client network address.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${client_helo}\fR
/*	This macro expands to the remote client HELO command parameter.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${client_hostname}\fR
/*	This macro expands to the remote client hostname.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${client_port}\fR
/*	This macro expands to the remote client TCP port number.
/* .sp
/*	This feature is available as of Postfix 2.5.
/* .IP \fB${client_protocol}\fR
/*	This macro expands to the remote client protocol.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${domain}\fR
/*	This macro expands to the domain portion of the recipient
/*	address.  For example, with an address \fIuser+foo@domain\fR
/*	the domain is \fIdomain\fR.
/* .sp
/*	This information is modified by the \fBh\fR flag for case folding.
/* .sp
/*	This feature is available as of Postfix 2.5.
/* .IP \fB${extension}\fR
/*	This macro expands to the extension part of a recipient address.
/*	For example, with an address \fIuser+foo@domain\fR the extension is
/*	\fIfoo\fR.
/* .sp
/*	A command-line argument that contains \fB${extension}\fR expands
/*	into as many command-line arguments as there are recipients.
/* .sp
/*	This information is modified by the \fBu\fR flag for case folding.
/* .IP \fB${mailbox}\fR
/*	This macro expands to the complete local part of a recipient address.
/*	For example, with an address \fIuser+foo@domain\fR the mailbox is
/*	\fIuser+foo\fR.
/* .sp
/*	A command-line argument that contains \fB${mailbox}\fR
/*	expands to as many command-line arguments as there are recipients.
/* .sp
/*	This information is modified by the \fBu\fR flag for case folding.
/* .IP \fB${nexthop}\fR
/*	This macro expands to the next-hop hostname.
/* .sp
/*	This information is modified by the \fBh\fR flag for case folding.
/* .IP \fB${original_recipient}\fR
/*	This macro expands to the complete recipient address before any
/*	address rewriting or aliasing.
/* .sp
/*	A command-line argument that contains
/*	\fB${original_recipient}\fR expands to as many
/*	command-line arguments as there are recipients.
/* .sp
/*	This information is modified by the \fBhqu\fR flags for quoting
/*	and case folding.
/* .sp
/*	This feature is available as of Postfix 2.5.
/* .IP \fB${queue_id}\fR
/*	This macro expands to the queue id.
/* .sp
/*	This feature is available as of Postfix 2.11.
/* .IP \fB${recipient}\fR
/*	This macro expands to the complete recipient address.
/* .sp
/*	A command-line argument that contains \fB${recipient}\fR
/*	expands to as many command-line arguments as there are recipients.
/* .sp
/*	This information is modified by the \fBhqu\fR flags for quoting
/*	and case folding.
/* .IP \fB${sasl_method}\fR
/*	This macro expands to the name of the SASL authentication
/*	mechanism in the AUTH command when the Postfix SMTP server
/*	received the message.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${sasl_sender}\fR
/*	This macro expands to the SASL sender name (i.e. the original
/*	submitter as per RFC 4954) in the MAIL FROM command when
/*	the Postfix SMTP server received the message.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${sasl_username}\fR
/*	This macro expands to the SASL user name in the AUTH command
/*	when the Postfix SMTP server received the message.
/* .sp
/*	This feature is available as of Postfix 2.2.
/* .IP \fB${sender}\fR
/*	This macro expands to the envelope sender address. By default,
/*	the null sender address expands to MAILER-DAEMON; this can
/*	be changed with the \fBnull_sender\fR attribute, as described
/*	above.
/* .sp
/*	This information is modified by the \fBq\fR flag for quoting.
/* .IP \fB${size}\fR
/*	This macro expands to Postfix's idea of the message size, which
/*	is an approximation of the size of the message as delivered.
/* .IP \fB${user}\fR
/*	This macro expands to the username part of a recipient address.
/*	For example, with an address \fIuser+foo@domain\fR the username
/*	part is \fIuser\fR.
/* .sp
/*	A command-line argument that contains \fB${user}\fR expands
/*	into as many command-line arguments as there are recipients.
/* .sp
/*	This information is modified by the \fBu\fR flag for case folding.
/* .RE
/* STANDARDS
/*	RFC 3463 (Enhanced status codes)
/* DIAGNOSTICS
/*	Command exit status codes are expected to
/*	follow the conventions defined in <\fBsysexits.h\fR>.
/*	Exit status 0 means normal successful completion.
/*
/*	In the case of a non-zero exit status, a limited amount of
/*	command output is logged, and reported in a delivery status
/*	notification.  When the output begins with a 4.X.X or 5.X.X
/*	enhanced status code, the status code takes precedence over
/*	the non-zero exit status (Postfix version 2.3 and later).
/*
/*	After successful delivery (zero exit status) a limited
/*	amount of command output is logged, and reported in "success"
/*	delivery status notifications (Postfix 3.0 and later).
/*	This command output is not examined for the presence of an
/*	enhanced status code.
/*
/*	Problems and transactions are logged to \fBsyslogd\fR(8)
/*	or \fBpostlogd\fR(8).
/*	Corrupted message files are marked so that the queue manager
/*	can move them to the \fBcorrupt\fR queue for further inspection.
/* SECURITY
/* .fi
/* .ad
/*	This program needs a dual personality 1) to access the private
/*	Postfix queue and IPC mechanisms, and 2) to execute external
/*	commands as the specified user. It is therefore security sensitive.
/* CONFIGURATION PARAMETERS
/* .ad
/* .fi
/*	Changes to \fBmain.cf\fR are picked up automatically as \fBpipe\fR(8)
/*	processes run for only a limited amount of time. Use the command
/*	"\fBpostfix reload\fR" to speed up a change.
/*
/*	The text below provides only a parameter summary. See
/*	\fBpostconf\fR(5) for more details including examples.
/* RESOURCE AND RATE CONTROLS
/* .ad
/* .fi
/*	In the text below, \fItransport\fR is the first field in a
/*	\fBmaster.cf\fR entry.
/* .IP "\fBtransport_time_limit ($command_time_limit)\fR"
/*	A transport-specific override for the command_time_limit parameter
/*	value, where \fItransport\fR is the master.cf name of the message
/*	delivery transport.
/* .PP
/*	Implemented in the qmgr(8) daemon:
/* .IP "\fBtransport_destination_concurrency_limit ($default_destination_concurrency_limit)\fR"
/*	A transport-specific override for the
/*	default_destination_concurrency_limit parameter value, where
/*	\fItransport\fR is the master.cf name of the message delivery
/*	transport.
/* .IP "\fBtransport_destination_recipient_limit ($default_destination_recipient_limit)\fR"
/*	A transport-specific override for the
/*	default_destination_recipient_limit parameter value, where
/*	\fItransport\fR is the master.cf name of the message delivery
/*	transport.
/* MISCELLANEOUS CONTROLS
/* .ad
/* .fi
/* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
/*	The default location of the Postfix main.cf and master.cf
/*	configuration files.
/* .IP "\fBdaemon_timeout (18000s)\fR"
/*	How much time a Postfix daemon process may take to handle a
/*	request before it is terminated by a built-in watchdog timer.
/* .IP "\fBdelay_logging_resolution_limit (2)\fR"
/*	The maximal number of digits after the decimal point when logging
/*	sub-second delay values.
/* .IP "\fBexport_environment (see 'postconf -d' output)\fR"
/*	The list of environment variables that a Postfix process will export
/*	to non-Postfix processes.
/* .IP "\fBipc_timeout (3600s)\fR"
/*	The time limit for sending or receiving information over an internal
/*	communication channel.
/* .IP "\fBmail_owner (postfix)\fR"
/*	The UNIX system account that owns the Postfix queue and most Postfix
/*	daemon processes.
/* .IP "\fBmax_idle (100s)\fR"
/*	The maximum amount of time that an idle Postfix daemon process waits
/*	for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
/*	The maximal number of incoming connections that a Postfix daemon
/*	process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/*	The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/*	The process name of a Postfix command or daemon process.
/* .IP "\fBqueue_directory (see 'postconf -d' output)\fR"
/*	The location of the Postfix top-level queue directory.
/* .IP "\fBrecipient_delimiter (empty)\fR"
/*	The set of characters that can separate a user name from its
/*	extension (example: user+foo), or a .forward file name from its
/*	extension (example: .forward+foo).
/* .IP "\fBsyslog_facility (mail)\fR"
/*	The syslog facility of Postfix logging.
/* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
/*	A prefix that is prepended to the process name in syslog
/*	records, so that, for example, "smtpd" becomes "prefix/smtpd".
/* .PP
/*	Available in Postfix version 3.0 and later:
/* .IP "\fBpipe_delivery_status_filter ($default_delivery_status_filter)\fR"
/*	Optional filter for the \fBpipe\fR(8) delivery agent to change the
/*	delivery status code or explanatory text of successful or unsuccessful
/*	deliveries.
/* .PP
/*	Available in Postfix version 3.3 and later:
/* .IP "\fBenable_original_recipient (yes)\fR"
/*	Enable support for the original recipient address after an
/*	address is rewritten to a different address (for example with
/*	aliasing or with canonical mapping).
/* .IP "\fBservice_name (read-only)\fR"
/*	The master.cf service name of a Postfix daemon process.
/* SEE ALSO
/*	qmgr(8), queue manager
/*	bounce(8), delivery status reports
/*	postconf(5), configuration parameters
/*	master(5), generic daemon options
/*	master(8), process manager
/*	postlogd(8), Postfix logging
/*	syslogd(8), system logging
/* 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 <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <pwd.h>
#include <grp.h>
#include <fcntl.h>
#include <ctype.h>

#ifdef STRCASECMP_IN_STRINGS_H
#include <strings.h>
#endif

/* Utility library. */

#include <msg.h>
#include <vstream.h>
#include <vstring.h>
#include <argv.h>
#include <htable.h>
#include <dict.h>
#include <iostuff.h>
#include <mymalloc.h>
#include <mac_parse.h>
#include <set_eugid.h>
#include <split_at.h>
#include <stringops.h>

/* Global library. */

#include <recipient_list.h>
#include <deliver_request.h>
#include <mail_params.h>
#include <mail_version.h>
#include <mail_conf.h>
#include <bounce.h>
#include <defer.h>
#include <deliver_completed.h>
#include <sent.h>
#include <pipe_command.h>
#include <mail_copy.h>
#include <mail_addr.h>
#include <canon_addr.h>
#include <split_addr.h>
#include <off_cvt.h>
#include <quote_822_local.h>
#include <flush_clnt.h>
#include <dsn_util.h>
#include <dsn_buf.h>
#include <sys_exits.h>
#include <delivered_hdr.h>
#include <fold_addr.h>
#include <mail_parm_split.h>

/* Single server skeleton. */

#include <mail_server.h>

/* Application-specific. */

 /*
  * The mini symbol table name and keys used for expanding macros in
  * command-line arguments.
  * 
  * XXX Update  the parse_callback() routine when something gets added here,
  * even when the macro is not recipient dependent.
  */
#define PIPE_DICT_TABLE		"pipe_command"	/* table name */
#define PIPE_DICT_NEXTHOP	"nexthop"	/* key */
#define PIPE_DICT_RCPT		"recipient"	/* key */
#define PIPE_DICT_ORIG_RCPT	"original_recipient"	/* key */
#define PIPE_DICT_SENDER	"sender"/* key */
#define PIPE_DICT_USER		"user"	/* key */
#define PIPE_DICT_EXTENSION	"extension"	/* key */
#define PIPE_DICT_MAILBOX	"mailbox"	/* key */
#define PIPE_DICT_DOMAIN	"domain"/* key */
#define PIPE_DICT_SIZE		"size"	/* key */
#define PIPE_DICT_CLIENT_ADDR	"client_address"	/* key */
#define PIPE_DICT_CLIENT_NAME	"client_hostname"	/* key */
#define PIPE_DICT_CLIENT_PORT	"client_port"	/* key */
#define PIPE_DICT_CLIENT_PROTO	"client_protocol"	/* key */
#define PIPE_DICT_CLIENT_HELO	"client_helo"	/* key */
#define PIPE_DICT_SASL_METHOD	"sasl_method"	/* key */
#define PIPE_DICT_SASL_USERNAME	"sasl_username"	/* key */
#define PIPE_DICT_SASL_SENDER	"sasl_sender"	/* key */
#define PIPE_DICT_QUEUE_ID	"queue_id"	/* key */

 /*
  * Flags used to pass back the type of special parameter found by
  * parse_callback.
  */
#define PIPE_FLAG_RCPT		(1<<0)
#define PIPE_FLAG_USER		(1<<1)
#define PIPE_FLAG_EXTENSION	(1<<2)
#define PIPE_FLAG_MAILBOX	(1<<3)
#define PIPE_FLAG_DOMAIN	(1<<4)
#define PIPE_FLAG_ORIG_RCPT	(1<<5)

 /*
  * Additional flags. These are colocated with mail_copy() flags. Allow some
  * space for extension of the mail_copy() interface.
  */
#define PIPE_OPT_FOLD_BASE	(16)
#define PIPE_OPT_FOLD_USER	(FOLD_ADDR_USER << PIPE_OPT_FOLD_BASE)
#define PIPE_OPT_FOLD_HOST	(FOLD_ADDR_HOST << PIPE_OPT_FOLD_BASE)
#define PIPE_OPT_QUOTE_LOCAL	(1 << (PIPE_OPT_FOLD_BASE + 2))
#define PIPE_OPT_FINAL_DELIVERY	(1 << (PIPE_OPT_FOLD_BASE + 3))

#define PIPE_OPT_FOLD_ALL	(FOLD_ADDR_ALL << PIPE_OPT_FOLD_BASE)
#define PIPE_OPT_FOLD_FLAGS(f) \
	(((f) & PIPE_OPT_FOLD_ALL) >> PIPE_OPT_FOLD_BASE)

 /*
  * Tunable parameters. Values are taken from the config file, after
  * prepending the service name to _name, and so on.
  */
int     var_command_maxtime;		/* You can now leave this here. */

 /*
  * Other main.cf parameters.
  */
char   *var_pipe_dsn_filter;

 /*
  * For convenience. Instead of passing around lists of parameters, bundle
  * them up in convenient structures.
  */

 /*
  * Structure for service-specific configuration parameters.
  */
typedef struct {
    int     time_limit;			/* per-service time limit */
} PIPE_PARAMS;

 /*
  * Structure for command-line parameters.
  */
typedef struct {
    char  **command;			/* argument vector */
    uid_t   uid;			/* command privileges */
    gid_t   gid;			/* command privileges */
    int     flags;			/* mail_copy() flags */
    char   *exec_dir;			/* working directory */
    char   *chroot_dir;			/* chroot directory */
    VSTRING *eol;			/* output record delimiter */
    VSTRING *null_sender;		/* null sender expansion */
    off_t   size_limit;			/* max size in bytes we will accept */
} PIPE_ATTR;

 /*
  * Structure for command-line parameter macro expansion.
  */
typedef struct {
    const char *service;		/* for warnings */
    int     expand_flag;		/* callback result */
} PIPE_STATE;

 /*
  * Silly little macros.
  */
#define STR	vstring_str

/* parse_callback - callback for mac_parse() */

static int parse_callback(int type, VSTRING *buf, void *context)
{
    PIPE_STATE *state = (PIPE_STATE *) context;
    struct cmd_flags {
	const char *name;
	int     flags;
    };
    static struct cmd_flags cmd_flags[] = {
	PIPE_DICT_NEXTHOP, 0,
	PIPE_DICT_RCPT, PIPE_FLAG_RCPT,
	PIPE_DICT_ORIG_RCPT, PIPE_FLAG_ORIG_RCPT,
	PIPE_DICT_SENDER, 0,
	PIPE_DICT_USER, PIPE_FLAG_USER,
	PIPE_DICT_EXTENSION, PIPE_FLAG_EXTENSION,
	PIPE_DICT_MAILBOX, PIPE_FLAG_MAILBOX,
	PIPE_DICT_DOMAIN, PIPE_FLAG_DOMAIN,
	PIPE_DICT_SIZE, 0,
	PIPE_DICT_CLIENT_ADDR, 0,
	PIPE_DICT_CLIENT_NAME, 0,
	PIPE_DICT_CLIENT_PORT, 0,
	PIPE_DICT_CLIENT_PROTO, 0,
	PIPE_DICT_CLIENT_HELO, 0,
	PIPE_DICT_SASL_METHOD, 0,
	PIPE_DICT_SASL_USERNAME, 0,
	PIPE_DICT_SASL_SENDER, 0,
	PIPE_DICT_QUEUE_ID, 0,
	0, 0,
    };
    struct cmd_flags *p;

    /*
     * See if this command-line argument references a special macro.
     */
    if (type == MAC_PARSE_VARNAME) {
	for (p = cmd_flags; /* see below */ ; p++) {
	    if (p->name == 0) {
		msg_warn("file %s/%s: service %s: unknown macro name: \"%s\"",
			 var_config_dir, MASTER_CONF_FILE,
			 state->service, vstring_str(buf));
		return (MAC_PARSE_ERROR);
	    } else if (strcmp(vstring_str(buf), p->name) == 0) {
		state->expand_flag |= p->flags;
		return (0);
	    }
	}
    }
    return (0);
}

/* morph_recipient - morph a recipient address */

static void morph_recipient(VSTRING *buf, const char *address, int flags)
{
    VSTRING *temp = vstring_alloc(100);

    /*
     * Quote the recipient address as appropriate.
     */
    if (flags & PIPE_OPT_QUOTE_LOCAL)
	quote_822_local(temp, address);
    else
	vstring_strcpy(temp, address);

    /*
     * Fold the recipient address as appropriate.
     */
    fold_addr(buf, STR(temp), PIPE_OPT_FOLD_FLAGS(flags));

    vstring_free(temp);
}

/* expand_argv - expand macros in the argument vector */

static ARGV *expand_argv(const char *service, char **argv,
			         RECIPIENT_LIST *rcpt_list, int flags)
{
    VSTRING *buf = vstring_alloc(100);
    ARGV   *result;
    char  **cpp;
    PIPE_STATE state;
    int     i;
    char   *ext;
    char   *dom;

    /*
     * This appears to be simple operation (replace $name by its expansion).
     * However, it becomes complex because a command-line argument that
     * references $recipient must expand to as many command-line arguments as
     * there are recipients (that's wat programs called by sendmail expect).
     * So we parse each command-line argument, and depending on what we find,
     * we either expand the argument just once, or we expand it once for each
     * recipient. In either case we end up parsing the command-line argument
     * twice. The amount of CPU time wasted will be negligible.
     * 
     * Note: we can't use recursive macro expansion here, because recursion
     * would screw up mail addresses that contain $ characters.
     */
#define NO	0
#define EARLY_RETURN(x) { argv_free(result); vstring_free(buf); return (x); }

    result = argv_alloc(1);
    for (cpp = argv; *cpp; cpp++) {
	state.service = service;
	state.expand_flag = 0;
	if (mac_parse(*cpp, parse_callback, (void *) &state) & MAC_PARSE_ERROR)
	    EARLY_RETURN(0);
	if (state.expand_flag == 0) {		/* no $recipient etc. */
	    argv_add(result, dict_eval(PIPE_DICT_TABLE, *cpp, NO), ARGV_END);
	} else {				/* contains $recipient etc. */
	    for (i = 0; i < rcpt_list->len; i++) {

		/*
		 * This argument contains $recipient.
		 */
		if (state.expand_flag & PIPE_FLAG_RCPT) {
		    morph_recipient(buf, rcpt_list->info[i].address, flags);
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_RCPT, STR(buf));
		}

		/*
		 * This argument contains $original_recipient.
		 */
		if (state.expand_flag & PIPE_FLAG_ORIG_RCPT) {
		    morph_recipient(buf, rcpt_list->info[i].orig_addr, flags);
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_ORIG_RCPT, STR(buf));
		}

		/*
		 * This argument contains $user. Extract the plain user name.
		 * Either anything to the left of the extension delimiter or,
		 * in absence of the latter, anything to the left of the
		 * rightmost @.
		 * 
		 * Beware: if the user name is blank (e.g. +user@host), the
		 * argument is suppressed. This is necessary to allow for
		 * cyrus bulletin-board (global mailbox) delivery. XXX But,
		 * skipping empty user parts will also prevent other
		 * expansions of this specific command-line argument.
		 */
		if (state.expand_flag & PIPE_FLAG_USER) {
		    morph_recipient(buf, rcpt_list->info[i].address,
				    flags & PIPE_OPT_FOLD_ALL);
		    if (split_at_right(STR(buf), '@') == 0)
			msg_warn("no @ in recipient address: %s",
				 rcpt_list->info[i].address);
		    if (*var_rcpt_delim)
			split_addr(STR(buf), var_rcpt_delim);
		    if (*STR(buf) == 0)
			continue;
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_USER, STR(buf));
		}

		/*
		 * This argument contains $extension. Extract the recipient
		 * extension: anything between the leftmost extension
		 * delimiter and the rightmost @. The extension may be blank.
		 */
		if (state.expand_flag & PIPE_FLAG_EXTENSION) {
		    morph_recipient(buf, rcpt_list->info[i].address,
				    flags & PIPE_OPT_FOLD_ALL);
		    if (split_at_right(STR(buf), '@') == 0)
			msg_warn("no @ in recipient address: %s",
				 rcpt_list->info[i].address);
		    if (*var_rcpt_delim == 0
			|| (ext = split_addr(STR(buf), var_rcpt_delim)) == 0)
			ext = "";		/* insert null arg */
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_EXTENSION, ext);
		}

		/*
		 * This argument contains $mailbox. Extract the mailbox name:
		 * anything to the left of the rightmost @.
		 */
		if (state.expand_flag & PIPE_FLAG_MAILBOX) {
		    morph_recipient(buf, rcpt_list->info[i].address,
				    flags & PIPE_OPT_FOLD_ALL);
		    if (split_at_right(STR(buf), '@') == 0)
			msg_warn("no @ in recipient address: %s",
				 rcpt_list->info[i].address);
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_MAILBOX, STR(buf));
		}

		/*
		 * This argument contains $domain. Extract the domain name:
		 * anything to the right of the rightmost @.
		 */
		if (state.expand_flag & PIPE_FLAG_DOMAIN) {
		    morph_recipient(buf, rcpt_list->info[i].address,
				    flags & PIPE_OPT_FOLD_ALL);
		    dom = split_at_right(STR(buf), '@');
		    if (dom == 0) {
			msg_warn("no @ in recipient address: %s",
				 rcpt_list->info[i].address);
			dom = "";		/* insert null arg */
		    }
		    dict_update(PIPE_DICT_TABLE, PIPE_DICT_DOMAIN, dom);
		}

		/*
		 * Done.
		 */
		argv_add(result, dict_eval(PIPE_DICT_TABLE, *cpp, NO), ARGV_END);
	    }
	}
    }
    argv_terminate(result);
    vstring_free(buf);
    return (result);
}

/* get_service_params - get service-name dependent config information */

static void get_service_params(PIPE_PARAMS *config, char *service)
{
    const char *myname = "get_service_params";

    /*
     * Figure out the command time limit for this transport.
     */
    config->time_limit =
	get_mail_conf_time2(service, _MAXTIME, var_command_maxtime, 's', 1, 0);

    /*
     * Give the poor tester a clue of what is going on.
     */
    if (msg_verbose)
	msg_info("%s: time_limit %d", myname, config->time_limit);
}

/* get_service_attr - get command-line attributes */

static void get_service_attr(PIPE_ATTR *attr, char **argv)
{
    const char *myname = "get_service_attr";
    struct passwd *pwd;
    struct group *grp;
    char   *user;			/* user name */
    char   *group;			/* group name */
    char   *size;			/* max message size */
    char   *cp;

    /*
     * Initialize.
     */
    user = 0;
    group = 0;
    attr->command = 0;
    attr->flags = 0;
    attr->exec_dir = 0;
    attr->chroot_dir = 0;
    attr->eol = vstring_strcpy(vstring_alloc(1), "\n");
    attr->null_sender = vstring_strcpy(vstring_alloc(1), MAIL_ADDR_MAIL_DAEMON);
    attr->size_limit = 0;

    /*
     * Iterate over the command-line attribute list.
     */
    for ( /* void */ ; *argv != 0; argv++) {

	/*
	 * flags=stuff
	 */
	if (strncasecmp("flags=", *argv, sizeof("flags=") - 1) == 0) {
	    for (cp = *argv + sizeof("flags=") - 1; *cp; cp++) {
		switch (*cp) {
		case 'B':
		    attr->flags |= MAIL_COPY_BLANK;
		    break;
		case 'D':
		    attr->flags |= MAIL_COPY_DELIVERED;
		    break;
		case 'F':
		    attr->flags |= MAIL_COPY_FROM;
		    break;
		case 'O':
		    attr->flags |= MAIL_COPY_ORIG_RCPT;
		    break;
		case 'R':
		    attr->flags |= MAIL_COPY_RETURN_PATH;
		    break;
		case 'X':
		    attr->flags |= PIPE_OPT_FINAL_DELIVERY;
		    break;
		case '.':
		    attr->flags |= MAIL_COPY_DOT;
		    break;
		case '>':
		    attr->flags |= MAIL_COPY_QUOTE;
		    break;
		case 'h':
		    attr->flags |= PIPE_OPT_FOLD_HOST;
		    break;
		case 'q':
		    attr->flags |= PIPE_OPT_QUOTE_LOCAL;
		    break;
		case 'u':
		    attr->flags |= PIPE_OPT_FOLD_USER;
		    break;
		default:
		    msg_fatal("unknown flag: %c (ignored)", *cp);
		    break;
		}
	    }
	}

	/*
	 * user=username[:groupname]
	 */
	else if (strncasecmp("user=", *argv, sizeof("user=") - 1) == 0) {
	    user = *argv + sizeof("user=") - 1;
	    if ((group = split_at(user, ':')) != 0)	/* XXX clobbers argv */
		if (*group == 0)
		    group = 0;
	    if ((pwd = getpwnam(user)) == 0)
		msg_fatal("%s: unknown username: %s", myname, user);
	    attr->uid = pwd->pw_uid;
	    if (group != 0) {
		if ((grp = getgrnam(group)) == 0)
		    msg_fatal("%s: unknown group: %s", myname, group);
		attr->gid = grp->gr_gid;
	    } else {
		attr->gid = pwd->pw_gid;
	    }
	}

	/*
	 * directory=string
	 */
	else if (strncasecmp("directory=", *argv, sizeof("directory=") - 1) == 0) {
	    attr->exec_dir = mystrdup(*argv + sizeof("directory=") - 1);
	}

	/*
	 * chroot=string
	 */
	else if (strncasecmp("chroot=", *argv, sizeof("chroot=") - 1) == 0) {
	    attr->chroot_dir = mystrdup(*argv + sizeof("chroot=") - 1);
	}

	/*
	 * eol=string
	 */
	else if (strncasecmp("eol=", *argv, sizeof("eol=") - 1) == 0) {
	    unescape(attr->eol, *argv + sizeof("eol=") - 1);
	}

	/*
	 * null_sender=string
	 */
	else if (strncasecmp("null_sender=", *argv, sizeof("null_sender=") - 1) == 0) {
	    vstring_strcpy(attr->null_sender, *argv + sizeof("null_sender=") - 1);
	}

	/*
	 * size=max_message_size (in bytes)
	 */
	else if (strncasecmp("size=", *argv, sizeof("size=") - 1) == 0) {
	    size = *argv + sizeof("size=") - 1;
	    if ((attr->size_limit = off_cvt_string(size)) < 0)
		msg_fatal("%s: bad size= value: %s", myname, size);
	}

	/*
	 * argv=command...
	 */
	else if (strncasecmp("argv=", *argv, sizeof("argv=") - 1) == 0) {
	    *argv += sizeof("argv=") - 1;	/* XXX clobbers argv */
	    attr->command = argv;
	    break;
	}

	/*
	 * Bad.
	 */
	else
	    msg_fatal("unknown attribute name: %s", *argv);
    }

    /*
     * Sanity checks. Verify that every member has an acceptable value.
     */
    if (user == 0)
	msg_fatal("missing user= command-line attribute");
    if (attr->command == 0)
	msg_fatal("missing argv= command-line attribute");
    if (attr->uid == 0)
	msg_fatal("user= command-line attribute specifies root privileges");
    if (attr->uid == var_owner_uid)
	msg_fatal("user= command-line attribute specifies mail system owner %s",
		  var_mail_owner);
    if (attr->gid == 0)
	msg_fatal("user= command-line attribute specifies privileged group id 0");
    if (attr->gid == var_owner_gid)
	msg_fatal("user= command-line attribute specifies mail system owner %s group id %ld",
		  var_mail_owner, (long) attr->gid);
    if (attr->gid == var_sgid_gid)
	msg_fatal("user= command-line attribute specifies mail system %s group id %ld",
		  var_sgid_group, (long) attr->gid);

    /*
     * Give the poor tester a clue of what is going on.
     */
    if (msg_verbose)
	msg_info("%s: uid %ld, gid %ld, flags %d, size %ld",
		 myname, (long) attr->uid, (long) attr->gid,
		 attr->flags, (long) attr->size_limit);
}

/* eval_command_status - do something with command completion status */

static int eval_command_status(int command_status, char *service,
			          DELIVER_REQUEST *request, PIPE_ATTR *attr,
			               DSN_BUF *why)
{
    RECIPIENT *rcpt;
    int     status;
    int     result = 0;
    int     n;
    char   *saved_text;

    /*
     * Depending on the result, bounce or defer the message, and mark the
     * recipient as done where appropriate.
     */
    switch (command_status) {
    case PIPE_STAT_OK:
	/* Save the command output before dsb_update() clobbers it. */
	vstring_truncate(why->reason, trimblanks(STR(why->reason),
			      VSTRING_LEN(why->reason)) - STR(why->reason));
	if (VSTRING_LEN(why->reason) > 0) {
	    VSTRING_TERMINATE(why->reason);
	    saved_text =
		vstring_export(vstring_sprintf(
				    vstring_alloc(VSTRING_LEN(why->reason)),
					    " (%.100s)", STR(why->reason)));
	} else
	    saved_text = mystrdup("");		/* uses shared R/O storage */
	dsb_update(why, "2.0.0", (attr->flags & PIPE_OPT_FINAL_DELIVERY) ?
		   "delivered" : "relayed", DSB_SKIP_RMTA, DSB_SKIP_REPLY,
		   "delivered via %s service%s", service, saved_text);
	myfree(saved_text);
	(void) DSN_FROM_DSN_BUF(why);
	for (n = 0; n < request->rcpt_list.len; n++) {
	    rcpt = request->rcpt_list.info + n;
	    status = sent(DEL_REQ_TRACE_FLAGS(request->flags),
			  request->queue_id, &request->msg_stats, rcpt,
			  service, &why->dsn);
	    if (status == 0 && (request->flags & DEL_REQ_FLAG_SUCCESS))
		deliver_completed(request->fp, rcpt->offset);
	    result |= status;
	}
	break;
    case PIPE_STAT_BOUNCE:
    case PIPE_STAT_DEFER:
	(void) DSN_FROM_DSN_BUF(why);
	for (n = 0; n < request->rcpt_list.len; n++) {
	    rcpt = request->rcpt_list.info + n;
	    /* XXX Maybe encapsulate this with ndr_append(). */
	    status = (STR(why->status)[0] != '4' ?
		      bounce_append : defer_append)
		(DEL_REQ_TRACE_FLAGS(request->flags),
		 request->queue_id,
		 &request->msg_stats, rcpt,
		 service, &why->dsn);
	    if (status == 0)
		deliver_completed(request->fp, rcpt->offset);
	    result |= status;
	}
	break;
    case PIPE_STAT_CORRUPT:
	/* XXX DSN should we send something? */
	result |= DEL_STAT_DEFER;
	break;
    default:
	msg_panic("eval_command_status: bad status %d", command_status);
	/* NOTREACHED */
    }

    return (result);
}

/* deliver_message - deliver message with extreme prejudice */

static int deliver_message(DELIVER_REQUEST *request, char *service, char **argv)
{
    const char *myname = "deliver_message";
    static PIPE_PARAMS conf;
    static PIPE_ATTR attr;
    RECIPIENT_LIST *rcpt_list = &request->rcpt_list;
    DSN_BUF *why = dsb_create();
    VSTRING *buf;
    ARGV   *expanded_argv = 0;
    int     deliver_status;
    int     command_status;
    ARGV   *export_env;
    const char *sender;

#define DELIVER_MSG_CLEANUP() { \
	dsb_free(why); \
	if (expanded_argv) argv_free(expanded_argv); \
    }

    if (msg_verbose)
	msg_info("%s: from <%s>", myname, request->sender);

    /*
     * Sanity checks. The get_service_params() and get_service_attr()
     * routines also do some sanity checks. Look up service attributes and
     * config information only once. This is safe since the information comes
     * from a trusted source, not from the delivery request.
     */
    if (request->nexthop[0] == 0)
	msg_fatal("empty nexthop hostname");
    if (rcpt_list->len <= 0)
	msg_fatal("recipient count: %d", rcpt_list->len);
    if (attr.command == 0) {
	get_service_params(&conf, service);
	get_service_attr(&attr, argv);
    }

    /*
     * The D flag cannot be specified for multi-recipient deliveries.
     */
    if ((attr.flags & MAIL_COPY_DELIVERED) && (rcpt_list->len > 1)) {
	dsb_simple(why, "4.3.5", "mail system configuration error");
	deliver_status = eval_command_status(PIPE_STAT_DEFER, service,
					     request, &attr, why);
	msg_warn("pipe flag `D' requires %s_destination_recipient_limit = 1",
		 service);
	DELIVER_MSG_CLEANUP();
	return (deliver_status);
    }

    /*
     * The O flag cannot be specified for multi-recipient deliveries.
     */
    if ((attr.flags & MAIL_COPY_ORIG_RCPT) && (rcpt_list->len > 1)) {
	dsb_simple(why, "4.3.5", "mail system configuration error");
	deliver_status = eval_command_status(PIPE_STAT_DEFER, service,
					     request, &attr, why);
	msg_warn("pipe flag `O' requires %s_destination_recipient_limit = 1",
		 service);
	DELIVER_MSG_CLEANUP();
	return (deliver_status);
    }

    /*
     * Check that this agent accepts messages this large.
     */
    if (attr.size_limit != 0 && request->data_size > attr.size_limit) {
	if (msg_verbose)
	    msg_info("%s: too big: size_limit = %ld, request->data_size = %ld",
		     myname, (long) attr.size_limit, request->data_size);
	dsb_simple(why, "5.2.3", "message too large");
	deliver_status = eval_command_status(PIPE_STAT_BOUNCE, service,
					     request, &attr, why);
	DELIVER_MSG_CLEANUP();
	return (deliver_status);
    }

    /*
     * Don't deliver a trace-only request.
     */
    if (DEL_REQ_TRACE_ONLY(request->flags)) {
	RECIPIENT *rcpt;
	int     status;
	int     n;

	deliver_status = 0;
	dsb_simple(why, "2.0.0", "delivers to command: %s", attr.command[0]);
	(void) DSN_FROM_DSN_BUF(why);
	for (n = 0; n < request->rcpt_list.len; n++) {
	    rcpt = request->rcpt_list.info + n;
	    status = sent(DEL_REQ_TRACE_FLAGS(request->flags),
			  request->queue_id, &request->msg_stats,
			  rcpt, service, &why->dsn);
	    if (status == 0 && (request->flags & DEL_REQ_FLAG_SUCCESS))
		deliver_completed(request->fp, rcpt->offset);
	    deliver_status |= status;
	}
	DELIVER_MSG_CLEANUP();
	return (deliver_status);
    }

    /*
     * Report mail delivery loops. By definition, this requires
     * single-recipient delivery. Don't silently lose recipients.
     */
    if (attr.flags & MAIL_COPY_DELIVERED) {
	DELIVERED_HDR_INFO *info;
	RECIPIENT *rcpt;
	int     loop_found;

	if (request->rcpt_list.len > 1)
	    msg_panic("%s: delivered-to enabled with multi-recipient request",
		      myname);
	info = delivered_hdr_init(request->fp, request->data_offset,
				  FOLD_ADDR_ALL);
	rcpt = request->rcpt_list.info;
	loop_found = delivered_hdr_find(info, rcpt->address);
	delivered_hdr_free(info);
	if (loop_found) {
	    dsb_simple(why, "5.4.6", "mail forwarding loop for %s",
		       rcpt->address);
	    deliver_status = eval_command_status(PIPE_STAT_BOUNCE, service,
						 request, &attr, why);
	    DELIVER_MSG_CLEANUP();
	    return (deliver_status);
	}
    }

    /*
     * Deliver. Set the nexthop and sender variables, and expand the command
     * argument vector. Recipients will be expanded on the fly. XXX Rewrite
     * envelope and header addresses according to transport-specific
     * rewriting rules.
     */
    if (vstream_fseek(request->fp, request->data_offset, SEEK_SET) < 0)
	msg_fatal("seek queue file %s: %m", VSTREAM_PATH(request->fp));

    /*
     * A non-empty null sender replacement is subject to the 'q' flag.
     */
    buf = vstring_alloc(10);
    sender = *request->sender ? request->sender : STR(attr.null_sender);
    if (*sender && (attr.flags & PIPE_OPT_QUOTE_LOCAL)) {
	quote_822_local(buf, sender);
	dict_update(PIPE_DICT_TABLE, PIPE_DICT_SENDER, STR(buf));
    } else
	dict_update(PIPE_DICT_TABLE, PIPE_DICT_SENDER, sender);
    if (attr.flags & PIPE_OPT_FOLD_HOST) {
	casefold(buf, request->nexthop);
	dict_update(PIPE_DICT_TABLE, PIPE_DICT_NEXTHOP, STR(buf));
    } else
	dict_update(PIPE_DICT_TABLE, PIPE_DICT_NEXTHOP, request->nexthop);
    vstring_sprintf(buf, "%ld", (long) request->data_size);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_SIZE, STR(buf));
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_CLIENT_ADDR,
		request->client_addr);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_CLIENT_HELO,
		request->client_helo);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_CLIENT_NAME,
		request->client_name);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_CLIENT_PORT,
		request->client_port);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_CLIENT_PROTO,
		request->client_proto);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_SASL_METHOD,
		request->sasl_method);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_SASL_USERNAME,
		request->sasl_username);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_SASL_SENDER,
		request->sasl_sender);
    dict_update(PIPE_DICT_TABLE, PIPE_DICT_QUEUE_ID,
		request->queue_id);
    vstring_free(buf);

    if ((expanded_argv = expand_argv(service, attr.command,
				     rcpt_list, attr.flags)) == 0) {
	dsb_simple(why, "4.3.5", "mail system configuration error");
	deliver_status = eval_command_status(PIPE_STAT_DEFER, service,
					     request, &attr, why);
	DELIVER_MSG_CLEANUP();
	return (deliver_status);
    }
    export_env = mail_parm_split(VAR_EXPORT_ENVIRON, var_export_environ);

    command_status = pipe_command(request->fp, why,
				  CA_PIPE_CMD_UID(attr.uid),
				  CA_PIPE_CMD_GID(attr.gid),
				  CA_PIPE_CMD_SENDER(sender),
				  CA_PIPE_CMD_COPY_FLAGS(attr.flags),
				  CA_PIPE_CMD_ARGV(expanded_argv->argv),
				  CA_PIPE_CMD_TIME_LIMIT(conf.time_limit),
				  CA_PIPE_CMD_EOL(STR(attr.eol)),
				  CA_PIPE_CMD_EXPORT(export_env->argv),
				  CA_PIPE_CMD_CWD(attr.exec_dir),
				  CA_PIPE_CMD_CHROOT(attr.chroot_dir),
			CA_PIPE_CMD_ORIG_RCPT(rcpt_list->info[0].orig_addr),
			  CA_PIPE_CMD_DELIVERED(rcpt_list->info[0].address),
				  CA_PIPE_CMD_END);
    argv_free(export_env);

    deliver_status = eval_command_status(command_status, service, request,
					 &attr, why);

    /*
     * Clean up.
     */
    DELIVER_MSG_CLEANUP();

    return (deliver_status);
}

/* pipe_service - perform service for client */

static void pipe_service(VSTREAM *client_stream, char *service, char **argv)
{
    DELIVER_REQUEST *request;
    int     status;

    /*
     * This routine runs whenever a client connects to the UNIX-domain socket
     * dedicated to delivery via external command. What we see below is a
     * little protocol to (1) tell the queue manager that we are ready, (2)
     * read a request from the queue manager, and (3) report the completion
     * status of that request. All connection-management stuff is handled by
     * the common code in single_server.c.
     */
    if ((request = deliver_request_read(client_stream)) != 0) {
	status = deliver_message(request, service, argv);
	deliver_request_done(client_stream, request, status);
    }
}

/* pre_accept - see if tables have changed */

static void pre_accept(char *unused_name, char **unused_argv)
{
    const char *table;

    if ((table = dict_changed_name()) != 0) {
	msg_info("table %s has changed -- restarting", table);
	exit(0);
    }
}

/* drop_privileges - drop privileges most of the time */

static void drop_privileges(char *unused_name, char **unused_argv)
{
    set_eugid(var_owner_uid, var_owner_gid);
}

/* pre_init - initialize */

static void pre_init(char *unused_name, char **unused_argv)
{
    flush_init();
}

MAIL_VERSION_STAMP_DECLARE;

/* main - pass control to the single-threaded skeleton */

int     main(int argc, char **argv)
{
    static const CONFIG_TIME_TABLE time_table[] = {
	VAR_COMMAND_MAXTIME, DEF_COMMAND_MAXTIME, &var_command_maxtime, 1, 0,
	0,
    };
    static const CONFIG_STR_TABLE str_table[] = {
	VAR_PIPE_DSN_FILTER, DEF_PIPE_DSN_FILTER, &var_pipe_dsn_filter, 0, 0,
	0,
    };

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

    single_server_main(argc, argv, pipe_service,
		       CA_MAIL_SERVER_TIME_TABLE(time_table),
		       CA_MAIL_SERVER_STR_TABLE(str_table),
		       CA_MAIL_SERVER_PRE_INIT(pre_init),
		       CA_MAIL_SERVER_POST_INIT(drop_privileges),
		       CA_MAIL_SERVER_PRE_ACCEPT(pre_accept),
		       CA_MAIL_SERVER_PRIVILEGED,
		       CA_MAIL_SERVER_BOUNCE_INIT(VAR_PIPE_DSN_FILTER,
						  &var_pipe_dsn_filter),
		       0);
}