#!/usr/bin/perl
#
# Copyright (c) 2002 Hajimu UMEMOTO <ume@mahoroba.org>.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $Mahoroba: src/misc/adfilter,v 1.5 2002/09/12 15:46:37 ume Exp $
#
# 「電子メールによる一方的な商業広告の送りつけ（いわゆる迷惑メール）に
# 関する新たな表示義務について」で規定される「！広告！」をフィルタする。
#
# http://www.meti.go.jp/kohosys/press/0002285/0/020110syoutorihiki.pdf
#
# 「未承諾広告※」
# http://www.meti.go.jp/policy/consumer/tokusho_amend.html
# http://www.zdnet.co.jp/news/0206/26/njbt_01.html
#
# 使用法:
#
#   - 本スクリプトを /usr/local/libexec/adfilter に EUC で保存し、実行
#   権限を付ける。
#
#   - .mc ファイルに以下の定義を追加し sendmail.cf を再作成する。
#
#	LOCAL_CONFIG
#	Kadsign program /usr/local/libexec/adfilter
#
#	LOCAL_RULESETS
#	HSubject: $>CheckSubject
#
#	SCheckSubject
#	R$*			$: $(adsign $1 $)
#	R@MATCH			$#discard $: discard

use Jcode;
use strict;

my $str = $ARGV[0];

# 空白、タブ、改行は sendmail によって空白代替文字に置換されている。空
# 白代替文字は cf では confBLANK_SUB で指定され、デフォルトは「.」であ
# る。
my $s = $str;
$s =~ s/(=\?=)\.(=\?ISO-2022-JP\?B\?)/$1 $2/igo;

my $jconv = new Jcode($s);
$str = '@MATCH' if ( $jconv->mime_decode =~ /(^(！|!)広告(！|!)|未承諾広告※)/o );
print "$str";
exit 0;