# correct-addr.rc
#
# $Id: correct-addr.rc,v 1.1 2002/01/01 22:25:33 jaalto Exp $
#
#    Copyright (C) 1996 Alan K. Stebbens <aks@sgi.com>
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
# Procmail recipe file to help forward mail from an OLD address to a
# NEW address, and do some mailing list mail management.
#
# This recipe file is intended to make it easy for users to forward
# their mail from their old address to a new address, and, at the same
# time, educate their correspondants about it by CC'ing them with the
# mail.
#
# Only mail directly addressing the user at the old address will cause a
# "correction notice" to be sent.
#
# Mail *not* directly addressing the old address (eg: from a mailing list)
# is treated separately, according to the MAILLIST variable; it can be one
# or more of these values:
#
#   drop	This is the default behaviour, and is only defined to
#		explicitly acknowledge this.  In other words, "drop"
#		and "forward" are mutually exclusive, and omitting
#		"forward" implies "drop", but not vice versa.
#
#   forward	forward all mailing list mail to $NEWADDR, inserting
#		"Resent-From:" and "Resent-To:" headers.  Of course,
#		$NEWADDR must also be defined.
#
#   report	report the headers of all mailing list mail to
#		$POSTMASTER, so that the person handling this role can
#		send the appropriate unsubscription requests.
#
# *** NOT IMPLEMENTED ***
#
#   bounce	return all mailing list mail with "User has moved!" to
#		the "request" or "owner" address; great pains are taken
#		to not respond to a general distribution list address.
#		If the proper list address cannot be determined, then
#		the ultimate fallback return address is "postmaster" at
#		the originating domain.
#
#   remove	If the originating mailing list software type can be
#		determined, automatically generate an "unsubscribe"
#		address on the $OLDADDR.  Currently, the recipe
#		understands Majordomo, SmartList, and LISTSERV commands.
#		If the mailing list software cannot be determined, then
#		falls back to "report" action.
#
#   change	If the originating mailing list software type can be
#		determined, automatically generate mails to the list
#		request address to unsubscribe the old address and to
#		subscribe the new address, if given.  If the mailing
#		list software cannot be determined, then falls back
#		to "report" action.
#
# Multiple keywords can be given to accomplish several things on the
# mailing list mail.
#
# Without the "forward" keyword, mailing list mail will not ever be
# forwarded, even if NEWADDR is defined.  Therefore, to have mailing
# list mail be both forwarded and bounced, use "forward,bounce".  To
# have mailing list mail be forwarded, and have the subscription
# changed where possible, use "forward,change".
#
#
# Usage:
#
#   These variables are *optional*, with the defaults as shown:
#
#	OLDLOGIN=$LOGNAME
#		The primary old login; this will be used in the
#		correction notice sent to correspondants.
#
#	OLDUSER=$FRIENDLY (see get-from.rc}
#		The user's old real name, included in the correction
#		notice.  If not set by the user, FRIENDLY is used, which
#		is determined by the procmail recipe file "get-from.rc".
#
#	OLDLOGINS='$\LOGNAME'
#		A regexp matching the old login name(s).  If the user
#		received mail at more than one login name, this should
#		match them all.  For most users, the default is fine.
#
#	NOTLOGINS=
#		A regexp matching logins mail to which should NOT be
#		forwarded or corrected.  This can be used to form
#		a filter to correct mail addressed ambiguously.  See
#		the man page for examples.
#
# 	NOTSUBJECTS=
#		Any mail containing subjects matching this regexp does
#		not get corrected or filtered.
#
#	DOMAIN=
#		The domain in which this user resides; without this
#		definition, this script can only match on the user
#		name.
#
#	HOSTS='[^. 	]+'
#		A regexp matching the hosts at which the OLDLOGIN
#		receives mail.  This is used in conjunction with $DOMAIN
#		so don't place the domain in this regexp.
#
#	NEWADDR=
#		The address to which mail should be forwarded.  There is
#		no default, resulting in no forwarding; in this case, only
#		reply with "no such user" notices.
#
#	NEWUSER=$OLDUSER
#		The new user name, defaulting to the old user name.  This
#		is used for correction notices.
#
#	POSTMASTER=Postmaster <postmaster>
#		This is used as the From: address for both the correction
#		"no such user" notices.
#
#	MAILLIST=[keyword,...]
#		One or more keywords: forward, report, bounce, remove,
#		or change, separated by spaces or commas.  See the
#		description above for details.
#
#	INCLUDERC=correct-addr.rc
#
# Examples:
#
# a. John Carter has moved from his current location to "carter@mars.com",
#    and he wishes to have his mailing mail forwarded.
#
#	NEWADDR   =	carter@mars.com
#	MAILLIST  =	forward
#	INCLUDERC = correct-addr.rc
#
# b. Clark Kent has moved back to his hometown, and does not want his
#    mail forwarded at all, especially his mailing lists.
#
#	NEWADDR				# guarantee no NEWADDR
#	MAILLIST  =	bounce,remove
#	INCLUDERC = correct-addr.rc
#
# c. Dennis Mitchell has been receiving mail by many aliases, and, having
#    gone off to college, wishes to have all of his mail sent to his
#    new email address.
#
#       NEWADDR   =	menace@engineering.ucsb.edu
#	OLDLOGINS =	"(Dennis|D.Mitchell|Dennis.Mitchell|Menace)"
#	MAILLIST  =	forward
#	INCLUDERC = correct-addr.rc
#
# d. Lois Lane has gotten married, and wishes to have her mail forwarded
#    to her new address, with her mailing list subscriptions changed, and
#    she wishes to have any correction notices mention her new name.
#
#	NEWADDR   =	lois@smallville.ia.us
#	OLDLOGINS =	"(Lois|Lane|L.Lane|Lois[._]Lane)"
#	NEWUSER   =	"Lois Kent"
#	MAILLIST  =	forward,change
#	INCLUDERC = correct-addr.rc
#
# e. Tom, a clever system manager, has installed an automatic alias for
#    users when their logins expires (and they no longer have a home
#    directory in which to place a ~/.procmailrc file), which invokes
#    a small shell script, called "correct-mail":
#
#	olduser1: "|correct-mail olduser1"
#	olduser2: "|correct-mail olduser2"
#
#    The shell script looks like this:
#
#	#!/bin/sh
#	PATH=$PATH:/usr/local/bin ; export PATH
#	procmail -m 	LOGNAME=$1 				\
#		    	MAILLIST=bounce,report			\
#			DEFAULT=/dev/null			\
#			MAILDIR=/tmp				\
#			LOGFILE=/usr/adm/correct-mail.log	\
#			LOGABSTRACT=yes				\
#		/etc/procmailrcs/correct-addr.rc
#

# First let's do some optional logging
# If the file "correct-addr.rc.log" exists, we log extensively
# to it.

:0
* ? test -f correct-addr.rc.log
{ CA_LOGFILE=$LOGFILE
  CA_LOGABSTRACT=$LOGABSTRACT
  CA_VERBOSE=$VERBOSE
  LOGFILE=correct-addr.rc.log
  LOGABSTRACT=all
  VERBOSE=yes
}

# A temporary file used to hold mail being reported to the postmaster
REPORTMAIL=tmp.ca-mail.$LOGNAME

# Make sure variables have default settings

OLDLOGIN=${OLDLOGIN:-$LOGNAME}
HOSTS=${HOSTS:-'[^. 	>(),;]+'}
POSTMASTER="${POSTMASTER:-\"Postmaster <postmaster>\"}"
MAILLIST=${MAILLIST:-forward}

DOMAIN="`echo \"$DOMAIN\" | sed -e 's/\\./\\\\./'`"

# HOSTPART matches the entire hostname part of an address
HOSTPART="(@($HOSTS(\.$DOMAIN)?|$DOMAIN))?([,();>	 ]|$)"

# Define a regexp matching the old addresses
:0
* OLDLOGINS ?? .
{ OLDADDRS="($OLDLOGIN|$OLDLOGINS)$HOSTPART" }

# There isn't a set of other logins
:0 E
{ OLDADDRS="$OLDLOGIN$HOSTPART" }

# Okay -- now begin the basic tests.

# Be sure we don't loop
:0
* $ ^X-Loop: $LOGNAME@$HOST
{ }

# Make sure that the negative filters do not apply

# If there is a NOTLOGINS defined, and it matches the addressee
# then don't correct/forward
:0 E
* NOTLOGINS ?? .
* $ ! ^TO$NOTLOGINS$HOSTPART
{ }

# If there is a NOTSUBJECTS defined, and it matches the subject
# then don't correct or forward
:0 E
* NOTSUBJECTS ?? .
* $ ! ^Subject: *$NOTSUBJECTS
{ }

# Else, if the mail matches the OLDLOGINS, then correct and forward
:0 E
* $ ^TO$OLDADDRS
{
  # Begin the correction and forwarding part
  OLDADDR=$MATCH

  :0
  * OLDADDR ?? [,(); 	>]$
  { OLDADDR="`echo \"$OLDADDR\" | sed -e 's/[,(); 	>]$//'`" }

  # First, save a copy
  LOCKFILE=$REPORTMAIL.lock

  :0 c
  $REPORTMAIL

  # Set OLDUSER to FRIENDLY if not already set
  :0
  * ! OLDUSER ?? .
  { INCLUDERC=get-from.rc
    OLDUSER=$FRIENDLY }

  # Generate a new header
  :0 fhw
  | formail -rt   -I"From: $POSTMASTER" \
		  -I"Subject: Your mail to $OLDADDR" \
		  -I"X-Loop: $LOGNAME@$HOST"

  # Is there a new address for forwarding?
  :0 a
  * NEWADDR ?? .
  {
    # Be sure NEWUSER is set
    NEWUSER=${NEWUSER:-$OLDUSER}

    # Make sure the new user gets a copy of the correction notice
    :0 afhw
    | formail -A"Cc: $NEWADDR ($NEWUSER)"

    :0 afbi
    | echo "Your mail to $OLDUSER at:" ;	\
      echo "" ;					\
      echo "	$OLDADDR" ;			\
      echo "" ;					\
      echo "is no longer correct; ${NEWUSER} now receives mail at:" ; \
      echo "" ;					\
      echo "	$NEWADDR" ;			\
      echo "" ;					\
      echo "This message, with your original mail, is also being forwarded" ; \
      echo "to the new address." ; 		\
      echo "" ;					\
      echo "Please remember to update the address you have for $NEWUSER in" ; \
      echo "any mail address database you may use."
  }

  # If NEWADDR is not set, just tell the sender that this address
  # is no longer valid
  :0 Efbi
  | echo "Your mail to $OLDUSER at:" ;	\
    echo "" ; 				\
    echo "	$OLDADDR" ;		\
    echo "" ;				\
    echo "is being returned because this user is no longer at this address" ; \
    echo "and no forwarding address has been provided."

  # Append the signature and the original mail, and send it
  :0 fb
  | cat ;					\
    echo "" ;					\
    echo "Regards, the $POSTMASTER" ;		\
    echo "" ;					\
    echo "Your original mail follows:" ;	\
    echo "------------------------------------------------------------" ; \
    formail <$REPORTMAIL

  JUNK=`rm -f $REPORTMAIL`

  LOCKFILE

  # Now ship off the mail to sendmail
  :0
  ! -oi -t
}

# If the mail wasn't directly to $OLDLOGIN, it is mail from a
# mailing list, so don't send a correction notice,

#### Mailing list mail ####

:0 E
* MAILLIST ?? (forward|report|bounce|remove|change)
* $!^X-Loop: $LOGNAME@$HOST
{

  # Both change and remove require some mailing list heuristics
  # Use common code for this
  :0
  * MAILLIST ?? (change|remove)
  {
    # get common header definitions
    INCLUDERC=headers.rc

    # Try to determine the mailer address
    INCLUDERC=list-addr.rc

    # ***** NOT YET IMPLEMENTED *****

  }

  :0c
  * MAILLIST ?? report
  {
    LOCKFILE=tmp.mail.lock
    :0 chw			# save a copy of the headers
    | sed -en '1,/^[	 ]*$/s/^/    /p' >tmp.mail

    :0 fhw			# generate report header to Postmaster
    | formail   -I"From:    Mailer-Daemon <mailer-daemon>"	         \
		-I"To:      $POSTMASTER"			         \
		-I"Subject: Mailing list mail to old address: $OLDLOGIN" \
		-I"X-Loop: $LOGNAME@$HOST"

    :0 afbwi			# make a report
    | echo "Mail is still being sent to $OLDLOGIN indirectly, possibly" ;     \
      echo "through a mailing list.  The headers of the mail are supplied " ; \
      echo "below." ;							      \
      echo "" ; 							      \
      echo "------------------- Original mail headers ------------------" ;   \
      cat tmp.mail

    LOCKFILE

    :0 aw			# file the report
    ! -oi -t
  }

  # forward it if NEWADDR defined, and MAILLIST includes "forward"
  :0
  * MAILLIST ?? forward
  * NEWADDR ?? .
  { # Add new headers indicating the forwarding
    :0 fhw
    | formail	-A"X-Loop: $LOGNAME@$HOST" 	\
		-i"Resent-From: $OLDADDR"	\
		-i"Resent-To:   $NEWADDR"
    :0 aw
    ! $NEWADDR
  }

  # Otherwise, assume a drop
  :0
  /dev/null

}