/* This file is part of mailfrom filter 
   Copyright (C) 2005, 2006 Sergey Poznyakoff

   This file is default configuration for mailfrom in Alt Linux.
   It written by Sergey Afonin.

   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, 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., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301 USA */

#include_once <status.mfh>

#include_once <dns.mf>
#include_once <match_cidr.mf>

#require sa

#pragma regex +extended +icase

set mailfrom_address ""

/*
Enable MTA-specific functions. Values:
sendmail - can be used
meta1    - not used now
postfix  - not used now
*/
set mta ""

set graylistactive 0

set msg_header ""
set msg_header_last_received ""

set infected_received_from ""

set mail_from ""
set rcpt_to ""
set queue_id ""
set queue_id_connect ""
set helo_from_remote ""

set virusmaster ""
set callback_chk_exclude "\n"
set massallocated_chk_exclude "\n"
set graylist_exclude "\n"
set explain_msg ""

set spam_verification_needed 0
set spamreject 0
set spammaster "spamalert@localhost"
set spamd_port ""
set explain_msg_spam ""
set X_Spam_Suffix ""

set ma_check 2

set bad_mail_from ".*\\|.*"
set good_mx "^((mx|mail|mta|relay|list|smtp|srv|server|dot).*)|(.*.(google|subscribe|yahoo|hotmail|mail)\.(com|ru))$"
set not_verifiable_mx "(\.mx\.mail\.yahoo\.com|\.namaeserver\.com)$"

#include_once </etc/mailfromd/localconf.rc>
#include_once </etc/mailfromd/userfunctions.rc>

prog connect
do
    set queue_id_connect $i

    if %ma_check = 1
       and
       not match_cidr_list(${client_addr}, %massallocated_chk_exclude) = 1
       and
       not dbmap("/etc/mailfromd/whitelist.db", "massallocated:" $client_addr, 1)

	set ma_hit_num massallocated_hit(${client_ptr}, %massallocated_regexps)

	if %ma_hit_num > 0
	    echo "%queue_id_connect: client's IP [" ${client_ptr} "]. Hit to R" %ma_hit_num "."
	    reject
	fi
    fi
done

prog helo
do
    # Save the helo of host for further use
    set helo_from_remote $1
    echo "%queue_id_connect: helo=" %helo_from_remote " client_addr=" ${client_addr}
done

prog envfrom
do

    set queue_id $i

    if not %queue_id = %queue_id_connect
	echo "%queue_id_connect: new message with queue id: " %queue_id
    fi

    if %mta = "sendmail"
	access_db_check("/etc/mail/access.db", "connect:" $client_addr)
	access_db_check("/etc/mail/access.db", tolower("from:" $f))
    fi

    if dbmap("/etc/mailfromd/whitelist.db", "global:" $client_addr, 1)
       or
       dbmap("/etc/mailfromd/whitelist.db", tolower("global:" $client_addr "-" $f), 1)
       or
       dbmap("/etc/mailfromd/whitelist.db", tolower("global:" $f), 1)
	accept
    fi

    if $f matches %bad_mail_from
	echo "%queue_id: bad mail from <$f>"
	reject 550 5.1.0 "bad mail from <$f>"
    fi

    set msg_header_last_received "Received: from " %helo_from_remote " ("
	hostname(${client_addr}) " ["${client_addr}"])\r\n\t"
	"by " %ehlo_domain " (" %__package__ "/" %__version__ ") id " $i ";\r\n\t"
	strftime('%a, %d %b %Y %T %z (%Z)', time())

    set infected_received_from hostname(${client_addr}) " ["${client_addr}"]"

    set mail_from "<" $f ">"

    if %ma_check = 2
       and
       not match_cidr_list(${client_addr}, %massallocated_chk_exclude) = 1
       and
       not dbmap("/etc/mailfromd/whitelist.db", "massallocated:" $client_addr, 1)

	set ma_hit_num massallocated_hit(${client_ptr}, %massallocated_regexps)
	
	if %ma_hit_num > 0
	    reject 550 5.7.1
		"Your reverse name is " ${client_ptr}
		"\nAccess from dsl/dial-up/cable/e.t.c. relays denied, client's IP [" ${client_addr} "]. Hit to R" %ma_hit_num ". " %explain_msg
	fi

    fi

    if hostname ${client_addr} = ${client_addr}
	echo "%queue_id: relay does not have a reverse name, graylistactive set to 1."
	set graylistactive 1
    elif %helo_from_remote matches "^[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}.[0-9]{1,3}$"
       or
       not %helo_from_remote matches "\."
	echo "%queue_id: bad helo, graylistactive set to 1."
	set graylistactive 1
    fi

    if not hostname ${client_addr} matches %good_mx
	echo "%queue_id: bad reverse name for smtp relay, spam_verification_needed set to 1"
	set spam_verification_needed 1
    fi

    catch failure or temp_failure
    do
	echo "%queue_id: Caught exception " $2 ", graylistactive set to 1."
	set graylistactive 1
    done

    if $f = ""
       or
       dbmap("/etc/mailfromd/whitelist.db", "from:" $client_addr, 1)
       or
       dbmap("/etc/mailfromd/whitelist.db", tolower("from:" $client_addr "-" $f), 1)
       or
       dbmap("/etc/mailfromd/whitelist.db", tolower("from:" $f), 1)
        pass
    elif $f mx matches %not_verifiable_mx
	echo "%queue_id: mx for $f always accepts bad rcpt to, graylisted."
	set graylistactive 1
    else
	if match_cidr_list(${client_addr}, %callback_chk_exclude) = 0
    	    on poll $f do
    	    when success:
        	pass
    	    when not_found:
        	if %last_poll_recv = ""
            	    if not %cache_used
                	echo "%queue_id: last_poll_recv empty, \"" $f "\" is not in cache"
            		reject 550 5.1.0
                	    "Sender validity for <" $f "> can not be confirm by MX"
            	    else
            		reject 550 5.1.0
                	    "Sender validity for <" $f "> hasn't been confirmed by MX, data has been cached for " %n_cache_time " sec."
		    fi
        	else
            	    reject 550 5.1.0
                	"Your MX reply is \"" %last_poll_recv "\""
                	"\nSender validity for <" $f "> not confirmed by MX \"" %last_poll_host "\""
        	fi
    	    when failure:
		echo "%queue_id: last_poll_recv = " %last_poll_recv " last_poll_host = " %last_poll_host
		reject 550 5.1.0 "Sender validity for <" $f "> can not be be verified, permanent error occurred"
    	    when temp_failure:
		if %last_poll_recv = ""
		    tempfail 450 4.4.1 "Sender validity for <" $f "> not confirmed by MX, MX does not respond"
        	elif %last_poll_recv = "nothing"
            	    tempfail 450 4.4.1
                	"Your MX has not replied a some command. Possible long timeout."
                	"\nSender validity for <" $f "> not confirmed by MX \"" %last_poll_host "\""
		else
		    tempfail 450 4.7.1 
			"Your MX reply is \"" %last_poll_recv "\""
			"\nSender validity for <" $f "> not confirmed by MX \"" %last_poll_host "\""
		fi
	    done
	fi
    fi

    if rate(tolower($f "-" ${client_addr}), interval("1 hour 30 minutes")) > 100
	echo "%queue_id: WARNING: Too big rate for E-Mail:IP pair $f-${client_addr}"
/*        tempfail 450 4.7.0 "Mail sending rate exceeded. Try again later" */
    fi
done

prog envrcpt
do
    set rcpt_to %rcpt_to $1 "\r\n"
    set gltime interval("25 minutes")
    if %graylistactive = 1
       and 
       not dbmap("/etc/mailfromd/whitelist.db", "graylist:" $client_addr, 1)
       and
       not match_cidr_list(${client_addr}, %graylist_exclude) = 1
	if greylist($client_addr "-" $f "-" $rcpt_addr, %gltime)
	    if %greylist_seconds_left = %gltime
		tempfail 450 4.7.0 "You are greylisted for " %gltime " seconds"
	    else
		tempfail 450 4.7.0 "Still greylisted for " %greylist_seconds_left " seconds"
            fi
	fi
    fi
done

func log_header_line(string hdr_line)
do
    set idx index(%hdr_line, "\n")-1
    if %idx < -1
	set idx -1
    fi
    set str1 substring(%hdr_line, 0, %idx)
    if index(%hdr_line, "\n") = -1
	echo "%queue_id: " %str1
    else
	echo "%queue_id: " %str1
	set str2 substring(%hdr_line, index(%hdr_line, "\n")+1, -1)
	log_header_line(%str2)
    fi
done

prog header
do
    set msg_header %msg_header $1 ": " $2 "\r\n"
    set full_header_line $1 ": " $2
    log_header_line(%full_header_line)

    catch failure
    do
	echo "%queue_id: error decoding string of header, caught exception: $2"
	# reject 554 5.7.0 "error decoding string of header; input string is not RFC 2047 encoded"
	continue
    done

    if message_header_decode($2, "KOI-8R") matches "ò A ó ó ù ì ï þ ë é"
	reject 554 5.7.0 "Spam messages rejected"
    fi
done

prog eom
do

    catch failure
    do
	echo "%queue_id: ERROR: mailfromd can not access to clamd, caught exception: $2"
	tempfail 451 4.3.0 "mailfromd can not access to clamd; please try again later"
    done

    if clamav(%clamd_port)
	set message <<- EOT
	    Subject: Virus intercepted
	    To: <%virusmaster>
	    From: <MAILER-DAEMON@%ehlo_domain>
	    MIME-Version: 1.0
	    Content-Type: text/plain; charset="us-ascii"
	    Content-Transfer-Encoding: 7bit
	    X-Agent: %__package__ (%__version__)
	    X-Infected-Received-From: %infected_received_from

	    The message %queue_id that sent from %mail_from to

	    %rcpt_to
	    contained a virus "%clamav_virus_name"
	    and has not been delivered.

	    Message tested by ClamAV: http://www.clamav.net

	    ----- The original (infected) message headers here:

	    %msg_header_last_received
	    %msg_header
	EOT

	echo "%queue_id: Virus founded: %clamav_virus_name from ${client_addr}"

	catch *
	do
	    echo "%queue_id: WARNING: message from daemon was not been sent to administrator, caught exception: $2"
	    reject 554 5.7.0 "virus %clamav_virus_name detected by ClamAV - http://www.clamav.net"
	done

	send_mail(%message, %virusmaster)
	reject 554 5.7.0 "virus %clamav_virus_name detected by ClamAV - http://www.clamav.net"
    fi

    if %spam_verification_needed = 1
       and
       not %spamd_port = ""
	set prec 3
	catch failure
	do
	    echo "%queue_id: ERROR: mailfromd can not access to Spamassasin, caught exception: $2"
	    tempfail 451 4.3.0 "mailfromd can not access to Spamassasin; please try again later"
	done
	if sa(%spamd_port,%prec,1)
	    if %spamreject = 1
		set message <<- EOT
		    Subject: spam blocked
		    To: <%spammaster>
		    From: <MAILER-DAEMON@%ehlo_domain>
		    MIME-Version: 1.0
		    Content-Type: text/plain; charset="us-ascii"
		    Content-Transfer-Encoding: 7bit
		    X-Agent: %__package__ (%__version__)
		    X-Infected-Received-From: %infected_received_from

		    The message %queue_id that sent from %mail_from to

		    %rcpt_to
		    detected as spam and blocked.

		    ----- The original (infected) message headers here:

		    %msg_header_last_received
		    %msg_header
		EOT

		catch *
		do
		    echo "%queue_id: WARNING: message from daemon was not been sent to administrator, caught exception: $2"
		    reject 554 5.7.0 "Spam detected by Spamassassin." %explain_msg_spam
		done

		send_mail(%message, %spammaster)
		reject 554 5.7.0 "Spam detected by Spamassassin." %explain_msg_spam
	    else
		if %mta = "sendmail"
		    header_add("X-Spamd-Flag" %X_Spam_Suffix, "YES")
		fi
	    fi
	fi
	echo "%queue_id: INFO: message processed by Spamassassin, sa_score=" %sa_score " sa_threshold=" %sa_threshold
	if %mta = "sendmail"
	    header_add("X-Spamd-Score" %X_Spam_Suffix, to_double_str(%sa_score, %prec))
	    header_add("X-Spamd-Threshold" %X_Spam_Suffix, to_double_str(%sa_threshold, %prec))
	    header_add("X-Spamd-Keywords" %X_Spam_Suffix, sa_format_report_header(%sa_keywords))
	fi
    fi

done