use pmg-smtp-filter instead of 'proxprox'

[pmg-api.git] / bin / pmg-smtp-filter

#!/usr/bin/perl

use strict;
use warnings;

use Carp;
use Getopt::Long;
use Time::HiRes qw (gettimeofday tv_interval);
use POSIX qw(:sys_wait_h errno_h signal_h);

use MIME::Parser;
use File::Path;
use Net::Server::PreFork;
use Net::Server::SIG qw(register_sig check_sigs);
use Net::SMTP;

use Fcntl ':flock';
use File::Basename;
use Xdgmime;

use PVE::SafeSyslog;
use PVE::ProcFSTools;
use PVE::INotify;

use Mail::SpamAssassin;
use Mail::SpamAssassin::NetSet;

use PMG::pmgcfg;
use PMG::Utils;
use PMG::Cluster;

use PMG::DBTools;
use PMG::RuleDB;
use PMG::RuleCache;
use PMG::ModGroup;
use PMG::AtomicFile;
use PMG::LDAPSet;
use PMG::Config;
use PMG::MailQueue;
use PMG::Unpack;
use PMG::SMTP;

use PMG::Unpack;
use PMG::Statistic;

use base qw(Net::Server::PreFork);

my $opt_commandline = [$0, @ARGV];
my $opt_max_dequeue = 1;
my $opt_dequeue_time = 60*2;

my $opt_ext_port = 10024;
my $opt_int_port = 10023;
my $opt_inject_port = 10025;

my $opt_testmode;
my $opt_untrusted;
my $opt_pidfile;
my $opt_database;

my $prog_name = 'pmg-smtp-filter';

initlog($prog_name, 'mail');

if (!GetOptions ('testmode=s' => \$opt_testmode,
		 'pidfile=s' => \$opt_pidfile,
		 'untrusted' => \$opt_untrusted,
		 'database=s' => \$opt_database)) {
    die "usage error\n";
    exit (-1);
}

$opt_pidfile = "/var/run/${prog_name}.pid" if !$opt_pidfile;

my $max_servers = 1;
my $min_servers = 1;
my $min_spare_servers = 0;
my $max_spare_servers = 0;
my $max_requests = 1;

if (!$opt_testmode) {

    my $pmg_cfg = PMG::Config->new();

    my $demo = $pmg_cfg->get('administration', 'demo');

    if ($demo) {
	syslog ('info', 'demo mode detected - not starting server');
	exit (0);
    }

    $max_servers = $pmg_cfg->get('mail', 'max_filters') + 2;
    $min_servers = 2;
    $min_spare_servers = 1;
    $max_spare_servers = 4;
    $max_requests = 20;
}

$opt_max_dequeue = 0 if $opt_testmode;

my $daemonize = 1;
if (defined ($ENV{BOUND_SOCKETS})) {
    $daemonize = undef;
}

my $server_attr = {
    port => [ $opt_int_port, $opt_ext_port ],
    host => '127.0.0.1',
    min_servers => $min_servers,
    max_servers => $max_servers,
    min_spare_servers => $min_spare_servers,
    max_spare_servers => $max_spare_servers,
    max_requests => $max_requests,
    serialize => 'flock',
    max_dequeue => $opt_max_dequeue,
    check_for_dequeue => $opt_dequeue_time,
    log_level => 3,
    pid_file => $opt_pidfile,
    no_close_by_child => 1,
    no_client_stdout => 1,
    commandline => $opt_commandline,
};

$server_attr->{setsid} = $daemonize if !$opt_testmode;

my $database;

if (defined($opt_database)) {
    $database = $opt_database;
} else {
    $database = $opt_testmode ? "Proxmox_testdb" : "Proxmox_ruledb";
}

$SIG{'__WARN__'} = sub {
    my $err = $@;
    my $t = $_[0];
    chomp $t;
    syslog('warning', "WARNING: %s", $t);
    $@ = $err;
};

sub get_prox_vars {
    my ($self, $queue, $entity, $msginfo, $rule, $targets, $spaminfo) = @_;

    $spaminfo = {
	sa_score => $queue->{sa_score},
	sa_hits => $queue->{sa_hits},
	sa_data => $queue->{sa_data},
	sa_max => $queue->{sa_max}
    } if !$spaminfo;

    my $vars = {
	'SUBJECT' => $entity->head->get ('subject', 0) || 'No Subject',
	'RULE' => $rule->{name},
	'RULE_INFO' => $msginfo->{rule_info},
	'SENDER' => $msginfo->{sender},
	'SENDER_IP' => $msginfo->{xforward}->{addr},
	'TARGETS' => join (', ', @$targets),
	'RECEIVERS' => join (', ', @{$msginfo->{targets}}),
	'SPAMLEVEL' => $spaminfo->{sa_score},
	'SPAMSTARS' => '*' x (($spaminfo->{sa_score} || 0) > 100 ? 100 : $spaminfo->{sa_score} || 0),
	'ADMIN' =>  $self->{pmg_cfg}->get('administration', 'email'),
	'HOST' =>  $msginfo->{hostname},
	'DOMAIN' =>  $msginfo->{domain},
	'FQDN' => $msginfo->{fqdn},
	'MSGID' => $queue->{msgid},
	'VERSION' => PMG::pmgcfg::package() . "/" . PMG::pmgcfg::version() . "/" . PMG::pmgcfg::repoid(),
    };

    $vars->{__spaminfo} = $spaminfo;

    if ($opt_testmode) {
	if ($queue->{vinfo_clam}) {
	    $vars->{'VIRUS_INFO'} = "Virus Info:";
	    $vars->{'VIRUS_INFO'} .= " clam: $queue->{vinfo_clam}" if $queue->{vinfo_clam};
	} else {
	    $vars->{'VIRUS_INFO'} = '';
	}
    } else {
	if ($queue->{vinfo}) {
	    $vars->{'VIRUS_INFO'} = "Virus Info: $queue->{vinfo}\n";
	} else {
	    $vars->{'VIRUS_INFO'} = '';
	}
    }

    $vars->{'SPAM_HITS'} = $spaminfo->{sa_hits};

    $vars->{'SPAM_INFO'} = '';
    my $sscores = $spaminfo->{sa_data};

    if (defined ($sscores) && @$sscores != -1) {
	my $sa_text;
	if ($opt_testmode) {
	    $sa_text = "Spam detection results:  100\n";
	} else {
	    $sa_text = "Spam detection results:  $spaminfo->{sa_score}\n";
	}

	foreach my $s (@$sscores) {
	    if ($opt_testmode) {
		$sa_text .= sprintf ("%-22s %6s %s\n", $s->{rule},
				     1, $s->{desc} || '-');
	    } else {
		$sa_text .= sprintf ("%-22s %6s %s\n", $s->{rule},
				     $s->{score}, $s->{desc} || '-');
	    }
	}
	$vars->{'SPAM_INFO'} = $sa_text;
    }

    if ($opt_testmode) {
	delete ($vars->{'ADMIN'});
 	#delete ($vars->{'SPAM_INFO'});
    }

    return $vars;
}

sub apply_rules {
    my ($self, $queue, $msginfo, $entity, $ldap) = @_;

    my $final;
    my %rule_targets;
    my %rule_actions;
    my %rule_marks;
    my $matching_rules = [];

    my $rulecache = $self->{rulecache};
    my $rules = $rulecache->rules ();
    my $dbh = $self->{ruledb}->{dbh};

    # first, we remove all conditional written 'X-' header attributes
    foreach my $rule (@$rules) {
	next if !$rule->{active};
	next if ($rule->{direction} == 0) &&  $msginfo->{trusted};
	next if ($rule->{direction} == 1) &&  !$msginfo->{trusted};

	my $actions = $rulecache->get_actions ($rule->{id});
	if ($actions) {
	    foreach my $action (@$actions) {
		if ($action->isa ("PMG::RuleDB::ModField")) {
		    my $fname = $action->{field};
		    next if $fname !~ m/^X-/i;
		    $entity->head->delete($fname);
		}
	    }
	}
    }

    foreach my $rule (@$rules) {
	next if !$rule->{active};
	next if ($rule->{direction} == 0) &&  $msginfo->{trusted};
	next if ($rule->{direction} == 1) &&  !$msginfo->{trusted};

	# match from, when and what classes (not target dependent)
	if (!($rulecache->from_match ($rule->{id}, $msginfo->{sender}, $msginfo->{xforward}->{addr}, $ldap) &&
	      $rulecache->when_match ($rule->{id}, time))) {
	    next;
	}

	$rule_marks{$rule->{id}} =
	    $rulecache->what_match ($rule->{id}, $queue, $entity, $msginfo, $dbh);

	$rule_actions{$rule->{id}} = $rulecache->get_actions ($rule->{id});
	my $fin = $rulecache->final ($rule->{id});

	# match targets
	foreach my $target (@{$msginfo->{targets}}) {
	    next if $final->{$target};
	    next if !defined ($rule_marks{$rule->{id}});
	    next if !defined ($rule_marks{$rule->{id}}->{$target});
	    next if !defined ($rule_marks{$rule->{id}}->{$target}->{marks});
	    next if !$rulecache->to_match ($rule->{id}, $target, $ldap);

	    $final->{$target} = $fin;

	    push @{$rule_targets{$rule->{id}}}, $target;
	}
    }

    # Compute rule_info (summary about matching rule)
    # this can be used for debugging
    my $rule_info = "";
    foreach my $rule (@$rules) {
	next if !$rule_targets{$rule->{id}};

	push @$matching_rules, $rule->{id};

	$rule_info .= "Rule: $rule->{name}\n";

	foreach my $target (@{$rule_targets{$rule->{id}}}) {
	    $rule_info .= "  Receiver: $target\n";
	}
	foreach my $action (@{$rule_actions{$rule->{id}}}) {
	    $rule_info .= "  Action: " . $action->short_desc () . "\n";
	}

    }
    $msginfo->{rule_info} = $rule_info;

    if ($msginfo->{testmode}) {
	my $vars = $self->get_prox_vars ($queue, $entity, $msginfo, undef, [], undef);
	my $out = "__RULE_INFO__";
	$out = PMG::Utils::subst_values ($out, $vars);
	my $fh = $msginfo->{test_fh};
	print $fh $out;
    }

    # apply actions

    my $mod_group = PMG::ModGroup->new($entity, $msginfo->{targets});

    foreach my $rule (@$rules) {
	my $targets = $rule_targets{$rule->{id}};
	next if !$targets;

	my $spaminfo;
	foreach my $t (@$targets) {
	    if ($rule_marks{$rule->{id}}->{$t} && $rule_marks{$rule->{id}}->{$t}->{spaminfo}) {
		$spaminfo = $rule_marks{$rule->{id}}->{$t}->{spaminfo};
		# we assume spam info is the same for all matching targets
		last;
	    }
	}

	my $vars = $self->get_prox_vars ($queue, $entity, $msginfo, $rule,
					 $rule_targets{$rule->{id}}, $spaminfo);


	my @sorted_actions =
	    sort {$a->priority <=> $b->priority} @{$rule_actions{$rule->{id}}};

	foreach my $action (@sorted_actions) {
	    $action->execute ($queue, $self->{ruledb}, $mod_group,
			      $rule_targets{$rule->{id}},
			      $msginfo, $vars, $rule_marks{$rule->{id}}->{marks}, $ldap);
	    last if $action->final;
	}
    }

    # we deliver all mail not matched by any rule
    # (default action = accept)
    my $unmatched;
    foreach my $target (@{$msginfo->{targets}}) {
	next if $final->{$target};

	push @$unmatched, $target;
    }

    if ($unmatched) {
	my $accept = PMG::RuleDB::Accept->new ();
	$accept->execute ($queue, $self->{ruledb}, $mod_group, $unmatched,
			  $msginfo, undef, undef, undef);
    }

    return $matching_rules;
}

# reload ruledb and pmg config
sub load_config {
    my $self = shift;
    my $prop = $self->{server};

    if ($self->{ruledb}) {
	$self->log (0, "reloading configuration $database");
	$self->{ruledb}->close ();
    }

    $self->{pmg_cfg} = PMG::Config->new();
    $self->{cinfo} = PVE::INotify::read_file("cluster.conf");

    eval {
	my $dbh = PMG::DBTools::open_ruledb ($database);
	$self->{ruledb} = PMG::RuleDB->new ($dbh);

	# load rulecache
	$self->{rulecache} = PMG::RuleCache->new ($self->{ruledb});
    };

    my $err = $@;

    if ($err) {
	sleep (10); # reduce restart rate when postgres is down
	die $err;
    }

    # create LDAP object
    $self->{ldap} = PMG::LDAPSet->new_from_pmg_cfg($self->{pmg_cfg}, 1);

    $self->{reload_config} = 0;
}

my $syslog_map = {
    0 => 'err',
    1 => 'warning',
    2 => 'notice',
    3 => 'info',
    4 => 'debug'
};

sub log {
    my ($self, $level, $msg, @therest) = @_;
    my $prop = $self->{server};

    return if $level =~ /^\d+$/ && $level > $prop->{log_level};

    $level = $syslog_map->{$level} || $level;
    if (@therest) {
        syslog($level, $msg, @therest);
    } else {
	syslog ($level, $msg);
    }
}

sub pre_loop_hook {
    my $self = shift;
    my $prop = $self->{server};

    $prop->{log_level} = 3;

    $self->log (0, "Filter daemon (re)started (max. $max_servers processes)");

    eval {  PMG::MailQueue::cleanup_active(); };
    $self->log (0, "Cleanup failures: $@") if $@;

    my $sig_set = POSIX::SigSet->new;
    $sig_set->addset (&POSIX::SIGHUP);
    $sig_set->addset (&POSIX::SIGCHLD);
    my $old_sig_set = POSIX::SigSet->new();

    sigprocmask (SIG_UNBLOCK, $sig_set, $old_sig_set);

    my ($backup_umask) = umask;

    my $pmg_cfg = PMG::Config->new();

    # Note: you need to restart the daemon when you change 'rbl_checks'
    my $rbl_checks = $pmg_cfg->get('spam', 'rbl_checks');

    $self->{sa} = Mail::SpamAssassin->new ({
	debug => 0,
	local_tests_only => $opt_testmode || !$rbl_checks,
	home_dir_for_helpers => '/root',
	userstate_dir => '/root/.spamassassin',
	dont_copy_prefs   => 1,
	stop_at_threshold => 0,
    });

    $self->{sa}->compile_now;

    alarm (0); # SA forgets to clear alarm in some cases
    umask ($backup_umask);
    initlog ($prog_name, 'mail');

    $SIG{'USR1'} = sub {
	# reloading server configuration
	if (defined $prop->{children}) {
	    foreach my $pid (keys %{$prop->{children}}) {
		kill (10, $pid); # SIGUSR1 childs
	    }
	}
    }
}

sub child_init_hook {
    my $self = shift;

    $0 = "$prog_name child";

    # $self->log (3, "init child");

    eval {
	$self->load_config ();
    };

    if ($@) {
	$self->log (0, $@);
	$self->child_finish_hook;
	exit;
    }

    $SIG{'USR1'} = sub {
	$self->{reload_config} = 1;
    }
}

sub child_finish_hook {
    my $self = shift;

    # $self->log (3, "finish child");
    $self->{ruledb}->close () if $self->{ruledb};
}

sub run_dequeue {
    my $self = shift;

    # do database maintainance here

    $self->log (2, "starting database maintainance");

    my ($csec, $usec) = gettimeofday ();

    my $cinfo = PVE::INotify::read_file("cluster.conf");

    my $dbh;

    eval {
	$dbh = PMG::DBTools::open_ruledb($database);
    };
    my $err = $@;

    if ($err) {
	$self->log (0, msgquote("ERROR: $err"));
	return;
    }

    eval {
	PMG::Statistic::update_stats($dbh, $cinfo);
    };
    $err = $@;

    my ($csec_end, $usec_end) = gettimeofday ();
    my $ptime = int (($csec_end-$csec)*1000 + ($usec_end - $usec)/1000);

    if ($err) {
	$self->log (0, msgquote($err));
    } else {
	$self->log (2, "end database maintainance ($ptime ms)");
    }

    $dbh->disconnect() if $dbh;
}


sub unpack_entity {
    my ($self, $unpack, $entity, $msginfo, $queue) = @_;

    my $magic;
    my $path;

    if (($magic = $entity->{PMX_magic_ct}) &&
	($path = $entity->{PMX_decoded_path})) {

	my $filename = basename ($path);

	if (PMG::Unpack::is_archive ($magic)) {
	    $self->log (3, "$queue->{logid}: found archive '$filename' ($magic)");

	    my $start = [gettimeofday];

	    $unpack->{mime} = {};

	    eval {
		$unpack->unpack_archive ($path, $magic);
	    };

	    $self->log (3, "$queue->{logid}: unpack failed - $@") if $@;

	    $entity->{PMX_content_types} = $unpack->{mime};

	    if ($opt_testmode) {
		my $types = join (", ", sort keys (%{$entity->{PMX_content_types}}));
		my $fh = $msginfo->{test_fh};
		$filename =~ s/\d+/X/g if $filename =~ m/^msg-\d+-\d+.msg/;
		print $fh "Types:$filename: $types\n" if $types;
	    }

	    my $elapsed = int(tv_interval ($start) * 1000);

	    $self->log (3, "$queue->{logid}: unpack archive '$filename' done ($elapsed ms)");
	}
    }

    foreach my $part ($entity->parts)  {
	$self->unpack_entity ($unpack, $part, $msginfo, $queue);
    }

}

sub handle_smtp {
    my ($self, $smtp) = @_;

    my ($csec, $usec) = gettimeofday ();

    my $queue;
    my $msginfo = {};
    my $pmg_cfg = $self->{pmg_cfg};
    my $ldap = $self->{ldap};
    my $cinfo = $self->{cinfo};
    my $lcid = $cinfo->{local}->{cid};

    $msginfo->{test_fh} = PMG::AtomicFile->new("testresult.out", "w")
	if $opt_testmode;

    $msginfo->{trusted} = $self->{trusted};


# PHASE 1 - save incoming mail (already done)
# on error: exit

    $queue = $smtp->{queue};
    $queue->{sa} = $self->{sa};

    $queue->{lic_valid} = 1;

    my $matching_rules;

    eval {
	$msginfo->{testmode} = $opt_testmode;
	$msginfo->{sender} = $smtp->{from};
	$msginfo->{xforward} = $smtp->{xforward};
	$msginfo->{targets} = $smtp->{to};

	$msginfo->{hostname} = PVE::INotify::nodename();
	my $resolv = PVE::INotify::read_file('resolvconf');

	$msginfo->{domain} = $resolv->{search};
	$msginfo->{fqdn} = "$msginfo->{hostname}.$msginfo->{domain}";
	$msginfo->{lcid} = $lcid;

	# $msginfo->{targets} is case sensitive,
	# but pmail is always lower case!

	foreach my $t (@{$msginfo->{targets}}) {
	    my $res;
	    if ($ldap && ($res = $ldap->account_info ($t))) {
		$msginfo->{pmail}->{$t} = $res->{pmail};
	    } else {
		$msginfo->{pmail}->{$t} = lc ($t);
	    }
	}

# PHASE 2 - parse mail
# on error: exit

	my $maxfiles = $pmg_cfg->get('clamav', 'archivemaxfiles');

	my $entity = $queue->parse_mail($maxfiles);

	$self->log (3, "$queue->{logid}: new mail message-id=%s", $queue->{msgid});

# PHASE 3 - run external content analyzers
# (SPAM analyzer is run on demand later)
# on error: log error messages


	# test for virus first
	$queue->{vinfo} = PMG::Utils::analyze_virus(
	    $queue, $queue->{dataname}, $pmg_cfg, $opt_testmode);

	# always add this headers to incoming mails
	# to enable user to report false negatives
	if (!$msginfo->{trusted}) {
	    if ($queue->{vinfo}) {
		$entity->head->replace('X-Proxmox-VInfo', $queue->{vinfo});
	    }
	}

	# we unpack after virus scanning, because this is more secure.
	# This way virus scanners gets the whole mail files and are able
	# to detect phishing signature for example - which would not work
	# if we decompose first and only analyze the decomposed attachments.
	# Disadvantage is that we need to unpack more than
	# once (bad performance).

	# should we scan content types inside archives

	my $rulecache = $self->{rulecache};

	my $scan_archives = 0;

	if (($rulecache->{archivefilter_in} && !$msginfo->{trusted}) ||
	    ($rulecache->{archivefilter_out} && $msginfo->{trusted})) {
	    $scan_archives = 1;
	}

	if ($scan_archives && !$queue->{vinfo}) {

	    # unpack all archives - determine contained content types

	    my $decdir = $queue->{dumpdir} . "/__decoded_archives";
	    mkdir $decdir;

	    my $start = [gettimeofday];

	    my $unpack;
	    eval {

		# limits: We use clamav limit for maxfiles, and scan
		# only 4 levels, timeout of 30 seconds

		$unpack = PMG::Unpack->new (
		    tmpdir => $decdir,
		    timeout => 30,
		    ctonly => 1, # only detect CTs
		    maxrec => -4,
		    maxfiles => $maxfiles);

		$self->unpack_entity ($unpack, $entity, $msginfo, $queue);
	    };

	    my $err = $@;

	    $unpack->cleanup() if $unpack;

	    my $elapsed = int(tv_interval ($start) * 1000);

	    if ($err) {
		$self->log (3, "$queue->{logid}: unpack archive failed ($elapsed ms) - $err");
	    }
	}

# PHASE 4 - apply rules
# on error: exit (cleanup process should do the rest)
	$msginfo->{maxspamsize} = $pmg_cfg->get('spam', 'maxspamsize');
	if ($msginfo->{maxspamsize} <= 1024*64) {
	    $msginfo->{maxspamsize} = 1024*64;
	}

	if ($msginfo->{trusted}) {
	    my $hide = $pmg_cfg->get('mail', 'hide_received');
	    $entity->head->delete("Received") if $hide;
	}

	$matching_rules = $self->apply_rules($queue, $msginfo, $entity, $ldap);
    };

    my $err = $@;

    $self->{errors} = $queue->{errors};

    # restart on error
    $self->{errors} = 1 if $err;

    $queue->close ();

    die $err if $err;

    my ($csec_end, $usec_end) = gettimeofday ();
    my $time_total =
	int (($csec_end-$csec)*1000 + ($usec_end - $usec)/1000);

# PHASE 5 - log statistics
# on error: log error messages

    eval {
	my $dbh = $self->{ruledb}->{dbh};
	my $where = "";
	foreach my $rid (@$matching_rules) {
	    $where .= $where ? " OR ID = $rid" : "ID = $rid";
	}
	if ($where) {
	    $dbh->do ("UPDATE Rule " .
		      "SET Count = Count + 1 " .
		      "WHERE $where");
	}

	my $insert_cmds = "SELECT nextval ('cstatistic_id_seq');INSERT INTO CStatistic " .
	    "(CID, RID, ID, Time, Bytes, Direction, Spamlevel, VirusInfo, PTime, Sender) VALUES (" .
	    "$lcid, currval ('cstatistic_id_seq'), currval ('cstatistic_id_seq'),";

	$insert_cmds .= $queue->{rtime} . ',';
	$insert_cmds .= $queue->{bytes} . ',';
	$insert_cmds .= $dbh->quote ($msginfo->{trusted} ? 0 : 1) . ',';
	$insert_cmds .= ($queue->{sa_score} || 0) . ',';
	$insert_cmds .= $dbh->quote ($queue->{vinfo}) . ',';
	$insert_cmds .= $time_total . ',';
	$insert_cmds .= $dbh->quote ($msginfo->{sender}) . ');';

	foreach my $r (@{$msginfo->{targets}}) {
	    my $tmp = $dbh->quote ($r);
	    my $blocked = $queue->{status}->{$r} eq 'blocked' ? 1 : 0;
	    $insert_cmds .= "INSERT INTO CReceivers (CStatistic_CID, CStatistic_RID, Receiver, Blocked) " .
		"VALUES ($lcid, currval ('cstatistic_id_seq'), $tmp, '$blocked'); ";
	}

	$dbh->do ($insert_cmds);
    };

    # save $err (because log clears $@)
    $err = $@;

    $time_total = $time_total/1000;

    my $ptspam = ($queue->{ptime_spam} || 0)/1000;
    my $ptclam = ($queue->{ptime_clam} || 0)/1000;

    $self->log (3, "$queue->{logid}: processing time: ${time_total} seconds ($ptspam, $ptclam)");

    $msginfo->{test_fh}->close if $opt_testmode;

    die $err if ($err);
}


sub process_request {
  my $self = shift;
  my $prop = $self->{server};
  my $sock = $prop->{client};

  eval {

      # make sure the ldap cache is up to date
      $self->{ldap}->update (1);

      $self->load_config() if $self->{reload_config};

      $self->{trusted} = 0;
      if ($prop->{sockport} == $opt_int_port && !$opt_untrusted) {
	  $self->{trusted} = 1;
      }

      my $smtp = PMG::SMTP->new ($sock);

      my $maxcount = $max_requests - $prop->{requests};

      my $count = $smtp->loop (\&handle_smtp, $self, $maxcount);
      if ($count > 1) {
	  $prop->{requests} += $count - 1;
      }
  };

  my $err = $@;

  $self->log (0, $err) if $err;

  kill (15, $prop->{ppid}) if $opt_testmode;

  my $mem = PVE::ProcFSTools::read_memory_usage();

  if ($opt_testmode) {
      $self->log (0, "memory usage: $mem->{size} bytes");
  } else {
      if ($self->{errors}) {
	  $self->log (0, "fast exit because of errors (free $mem->{size} bytes)");
	  $self->done (1);
      } elsif ($mem->{size} > (300*1024*1024)) {
	  $self->log (0, "fast exit to reduce server load (free $mem->{size} bytes)");
	  $self->done (1);
     }
  }

  $self->done (1) if $err;
}

# test sig_hup with: for ((;;)) ;do kill -HUP  `cat /var/run/${prog_name}.pid`; done;
# wrapper to avoid multiple calls to sig_hup
sub sig_hup {
  my $self = shift;
  my $prop = $self->{server};

  return if defined ($prop->{_HUP}); # do not call twice

  $self->SUPER::sig_hup();
}

sub restart_close_hook {
  my $self = shift;

  my $sig_set = POSIX::SigSet->new;
  $sig_set->addset (&POSIX::SIGHUP);
  $sig_set->addset (&POSIX::SIGCHLD); # to avoid zombies
  my $old_sig_set = POSIX::SigSet->new();

  sigprocmask (SIG_BLOCK, $sig_set, $old_sig_set);
}

sub pre_server_close_hook {
    my $self = shift;
    my $prop = $self->{server};

    if (defined $prop->{_HUP}) {
	undef $prop->{pid_file_unlink};
    }

    if (defined $prop->{children}) {
	foreach my $pid (keys %{$prop->{children}}) {
	    kill (1, $pid); # HUP childs
	}
    }

    # nicely shutdown childs (give them max 30 seconds to shut down)
    my $previous_alarm = alarm (30);
    eval {
	local $SIG{ALRM} = sub { die "Timed Out!\n" };

	my $pid;
	1 while ((($pid = waitpid (-1, 0)) > 0) || ($! == EINTR));
    };
    alarm ($previous_alarm);
}

# initialize mime system before fork
xdg_mime_get_mime_type_for_file ($0);

my $server = bless {
    server => $server_attr,
};

if (!$opt_testmode) {
    $server->run ();
} else {
    if (fork) {
	$server->run ();
    } else {
	sleep (1);
	my $sender ='sender@proxtest.com';
	my $targets = ['target1@proxtest.com',
		       'target2@proxtest.com',
		       'target3@proxtest.com'];

	my $smtp = Net::SMTP->new ('127.0.0.1', Port => 10023);

	die "unable to connect $!" if !$smtp;

	# syslog ('info', "connected to " . $smtp->domain);

	$smtp->mail ($sender);
	$smtp->to (@$targets);

	$smtp->data();

	open (TMP, $opt_testmode) ||
	    die "unable to upen file '$opt_testmode' - $! :ERROR";
	while (<TMP>) {
	    $smtp->datasend ($_);
	}
	close TMP;

	$smtp->datasend ("\n");
	$smtp->dataend ();

	$smtp->quit;
    }
}

exit (0);

__END__

=head1 NAME

pmg-smtp-filter - the Proxmox mail filter

=head1 SYNOPSIS

pmg-smtp-filter [-u] [-t testfile]

=head1 DESCRIPTION

Documentation is available at www.proxmox.com