#!/usr/bin/perl -wT

# (c) 2002 Peter Palfrader <peter@palfrader.org>
# $Id: pingd,v 1.24 2002/07/10 12:42:56 weasel Exp $
#

=pod

=head1 NAME

pingd - echolot ping daemon

=head1 SYNOPSIS

=over

=item B<pingd> B<start>

=item B<pingd> B<stop>

=item B<pingd> B<process>

=item B<pingd> B<add> I<address> [I<address> ...]

=item B<pingd> B<delete> I<address> [I<address> ...]

=item B<pingd> B<set> option=value [option=value..] I<address> [I<address> ...]

=item B<pingd> B<setremailercaps> I<capsstring>

=item B<pingd> B<deleteremailercaps> I<address>

=item B<pingd> B<getkeyconf>

=item B<pingd> B<dumpconf>

=back

=head1 DESCRIPTION

pingd is a the heart of echolot. Echolot is a pinger for anonymous remailers. 

A Pinger in the context of anonymous remailers is a program that regularily
sends messages through remailers to check their reliability. It then calculates
reliability statistics which are used by remailer clients to choose the chain
of remailers to use.

Additionally it collects configuration parameters and keys of all remailers and
offers them in a format readable by remailer clients. 

When called without parameters pingd schedules tasks like sending pings,
processing incoming mail and requesting remailer-xxx data and runs them in
configurable intervalls.

=head1 COMMANDS

=over

=item B<start>

Start the ping daemon.

=item B<stop>

Send the running pingd process a SIGTERM.

=item B<process>

Sends a HUP signal to the daemon which instructs it to process the commands.

For other affects of sending the HUP Signal see the SIGNALS section below.

=item B<add> I<address> [I<address> ...]

Add I<address> to the list of remailers to query for
keys and confs.

=item B<delete> I<address> [I<address> ...]

Delete I<address> from the list of remailers to query for
keys and confs. Delete all statistics and key for that remailer.

=item B<set> option=value [option=value..] I<address> [I<address> ...]

Possible options and values:

=over

=item B<showit=>{B<on>,B<off>}

Set B<showit> (show remailer in mlist, rlist etc.) for remailer I<address> to
either B<on> or B<off>.

=item B<pingit=>{B<on>,B<off>}

Set B<pingit> (send out pings to that remailer) for remailer I<address> to
either B<on> or B<off>.

=item B<fetch=>{B<on>,B<off>}

Set B<fetch> (fetch remailer-key and remailer-conf) for remailer I<address> to
either B<on> or B<off>.

=back

=item B<setremailercaps> I<capsstring>

Some remailers (Mixmaster V2 - currently lcs and passthru2) don't return a
useable remailer-conf message. For such remailers you need to set it manually.

For instance:

    ./pingd setremailercaps '$remailer{"passthru2"} = "<mixer@immd1.informatik.uni-erlangen.de> mix middle";'
    ./pingd setremailercaps '$remailer{"lcs"} = "<mix@anon.lcs.mit.edu> mix klen1000";'

=item B<deleteremailercaps> I<address>

Delete remailer-conf data for I<address>. The config data will be reset from
the next valid remailer-conf reply by the remailer.

=item B<getkeyconf>

Send a command to immediatly request keys and configuration from remailers.

=item B<dumpconf>

Dumps the current configuration to standard output.

=back

=head1 OPTIONS

=over

=item --verbose

Verbose mode. Causes B<pingd> to print debugging messages about its progress.

=item --help

Print a short help and exit sucessfully.

=item --version

Print version number and exit sucessfully.

=item --nohup

Usefull only when passed with the B<add>, B<set>, B<setremailercaps>,
B<deleteremailercaps> or B<getkeyconf> command.

Don't send a HUP signal to the daemon which instructs it to process the
commands after adding the command to the task list.

Per default such a signal is sent.

=item --process

Usefull only when passed with the B<start> command.

Read and process the commands file on startup.

=item --detach

Usefull only when passwd with the B<start> command.

Tell B<pingd> to detach.

=back

=head1 FILES

The configuration file is searched in those places in that order:

=over   

=item the file pointed to by the B<ECHOLOT_CONF> environment variable

=item `pwd`/pingd.conf

=item $HOME/echolot/pingd.conf

=item $HOME/pingd.conf

=item $HOME/.pingd.conf

=item /etc/pingd.conf

=back

=head1 SIGNALS

On B<SIGINT>, B<SIGQUIT>, and B<SIGTERM> B<pingd> will schedule a shutdown
for as soon as the current actions are finished or immediatly if no actions are
currently beeing processed. It will then write all metadata and pingdata to
disk and close all files cleanly before exiting.

On B<SIGHUP> <pingd> will execute any pending commands from the commands file
(B<commands.txt> per default).  It also closes and reopens the file 'output'
which is used for stdout and stderr in case the daemon was told to detach.
This can be used if you want to rotate that file.

=head1 AUTHOR

Peter Palfrader E<lt>peter@palfrader.orgE<gt>

=head1 BUGS

Please report them at E<lt>URL:http://savannah.gnu.org/bugs/?group=echolotE<gt>

=cut

use strict;
use Getopt::Long;
use English;
use Carp;
use lib qw{ . lib };
use Echolot::Config;
use Echolot::Globals;
use Echolot::Storage::File;
use Echolot::Scheduler;
use Echolot::Conf;
use Echolot::Mailin;
use Echolot::Pinger;
use Echolot::Stats;
use Echolot::Commands;
use Echolot::Thesaurus;

$ENV{'PATH'} = '/bin:/usr/bin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};


my $VERSION = '2.0beta1';


my $redirected_stdio = 0;

sub setSigHandlers() {
	$SIG{'HUP'} = sub {
		print "Got SIGHUP. scheduling readcommands\n";
		Echolot::Globals::get()->{'scheduler'}->schedule('readcommands', time() );
		if ($redirected_stdio) {
			close STDOUT;
			close STDERR;
			open (STDOUT, ">>output") or die ("Cannot open 'output' as STDOUT\n");
			open (STDERR, ">&STDOUT") or die ("Cannot dup STDOUT as STDERR\n");
		};
	};
	$SIG{'INT'} = sub {
		print "Got SIGINT. scheduling exit\n";
		Echolot::Globals::get()->{'scheduler'}->schedule('exit', time() );
	};
	$SIG{'QUIT'} = sub {
		print "Got SIGQUIT. scheduling exit\n";
		Echolot::Globals::get()->{'scheduler'}->schedule('exit', time() );
	};
	$SIG{'TERM'} = sub {
		print "Got SIGTERM. scheduling exit\n";
		Echolot::Globals::get()->{'scheduler'}->schedule('exit', time() );
	};
};



sub commit_prospective_address() {
	Echolot::Globals::get()->{'storage'}->commit_prospective_address();
};
sub expire() {
	Echolot::Globals::get()->{'storage'}->expire();
};





sub command_adddelete(@) {
	my $command = shift @_;
	my @argv = @_;

	die ("command_adddelete requires command\n") unless defined $command;
	die ("add requires argument <address>\n") unless scalar @argv;
	my @addresses;
	for my $address (@argv) {
		die ("argument <address> is not a valid email address\n") unless ($address =~ /^[a-zA-Z0-9+._-]+\@[a-zA-Z0-9+.-]+$/ );
		push @addresses, $address;
	};
	for my $address (@addresses) {
		Echolot::Commands::addCommand("$command $address");
	};
};

sub command_set(@) {
	my @argv = @_;

	my @settings;
	while (scalar @argv && $argv[0] =~ /^(showit|pingit|fetch)=(on|off)$/) {
		push @settings, $argv[0];
		shift @argv;
	};

	my @addresses;
	for my $address (@argv) {
		die ("argument $address is not a valid email address\n") unless ($address =~ /^[a-zA-Z0-9+._-]+\@[a-zA-Z0-9+.-]+$/ );
		push @addresses, $address;
	};

	for my $address (@argv) {
		for my $setting (@settings) {
			Echolot::Commands::addCommand("set $address $setting");
		};
	};
};

sub command_setremailercaps(@) {
	my @argv = @_;

	my @caps;
	for my $caps (@argv) {
		my ($remailer_nick, $remailer_address) = ($caps =~ /^\s*  \$remailer{"(.*)"}  \s*=\s*  "<(.*@.*)>.*";   \s*$/ix);
		die ("caps '$caps' is not a valid remailer caps line\n") unless (defined $remailer_nick && defined $remailer_address);
		push @caps, {
			address => $remailer_address,
			caps => $caps };
	};
	for my $caps (@caps) {
		Echolot::Commands::addCommand("setremailercaps ".$caps->{'address'}." ".$caps->{'caps'});
	};
};

sub command_deleteremailercaps(@) {
	my @argv = @_;

	my @addresses;
	for my $address (@argv) {
		die ("argument $address is not a valid email address\n") unless ($address =~ /^[a-zA-Z0-9+._-]+\@[a-zA-Z0-9+.-]+$/ );
		push @addresses, $address;
	};

	for my $address (@argv) {
		Echolot::Commands::addCommand("deleteremailercaps $address");
	};
};


sub pid_exists() {
	return (-e Echolot::Config::get()->{'pidfile'});
};

sub daemon_run() {
	die ("Pidfile '".Echolot::Config::get()->{'pidfile'}."' exists\n")
		if pid_exists();
	open (PIDFILE, '>'.Echolot::Config::get()->{'pidfile'}) or
		croak ("Cannot open pidfile '".Echolot::Config::get()->{'pidfile'}."': $!\n");
	print PIDFILE "$PROCESS_ID ".Echolot::Globals::get()->{'hostname'}." ".time()."\n";
	close PIDFILE;

	Echolot::Globals::initStorage();
	setSigHandlers();

	Echolot::Globals::get()->{'scheduler'} = new Echolot::Scheduler;
	my $scheduler = Echolot::Globals::get()->{'scheduler'};
	$scheduler->add('exit'                ,     -1                                         , 0, 'exit' );
	$scheduler->add('readcommands'        ,     -1                                         , 0, \&Echolot::Commands::processCommands );

	$scheduler->add('processmail'         , Echolot::Config::get()->{'processmail'}        , 0, \&Echolot::Mailin::process );
	$scheduler->add('ping'                , Echolot::Config::get()->{'pinger_interval'}    , 0, \&Echolot::Pinger::send_pings );
	$scheduler->add('buildstats'          , Echolot::Config::get()->{'buildstats'}         , 0, \&Echolot::Stats::build_stats );
	$scheduler->add('buildkeys'           , Echolot::Config::get()->{'buildkeys'}          , 0, \&Echolot::Stats::build_keys );
	$scheduler->add('buildthesaurus'      , Echolot::Config::get()->{'build_thesaurus'}    , 0, \&Echolot::Thesaurus::build_thesaurus );

	$scheduler->add('commitprospectives'  , Echolot::Config::get()->{'commitprospectives'} , 0, \&commit_prospective_address );
	$scheduler->add('expire'              , Echolot::Config::get()->{'expire'}             , 0, \&expire );
	$scheduler->add('getkeyconf'          , Echolot::Config::get()->{'getkeyconf'}         , 0, \&Echolot::Conf::send_requests );
	$scheduler->add('check_resurrection'  , Echolot::Config::get()->{'check_resurrection'} , 0, \&Echolot::Conf::check_resurrection );

	Echolot::Globals::get()->{'scheduler'}->schedule('readcommands', time() )
		if ($params->{'process'});

	$scheduler->run();

	Echolot::Globals::get()->{'storage'}->commit();
	Echolot::Globals::get()->{'storage'}->finish();

	unlink (Echolot::Config::get()->{'pidfile'}) or
		cluck ("Cannot unlink pidfile ".Echolot::Config::get()->{'pidfile'});
};

sub send_sig($) {
	my ($sig) = @_;

	die ("Pidfile '".Echolot::Config::get()->{'pidfile'}."' does not exist\n")
		unless pid_exists();
	open (PIDFILE, '<'.Echolot::Config::get()->{'pidfile'}) or
		croak ("Cannot open pidfile '".Echolot::Config::get()->{'pidfile'}."': $!\n");
	my $line = <PIDFILE>;
	close PIDFILE;

	my ($pid, $host, $time) = $line =~ /^(\d+) \s+ (\S+) \s+ (\d+) \s* $/x or
		croak ("Cannot parse pidfile '$line'\n");
	my $sent = kill $sig, $pid;
	($sent == 1) or
		croak ("Did not send signal $sig to exactly one process but $sent. (pidfile reads $line)\n");
};

sub daemon_hup() {
	send_sig(1);
};

sub daemon_stop() {
	send_sig(15);
};

sub make_dirs() {
	for my $dir (
		Echolot::Config::get()->{'resultdir'},
		Echolot::Config::get()->{'thesaurusdir'},
		Echolot::Config::get()->{'private_resultdir'},
		Echolot::Config::get()->{'gnupghome'},
		Echolot::Config::get()->{'tmpdir'},
		Echolot::Config::get()->{'storage'}->{'File'}->{'basedir'}
	) {
		if ( ! -d $dir ) {
			mkdir ($dir) or
				croak ("Cannot create directory $dir: $!\n");
		};
	};
	for my $dir (
		Echolot::Config::get()->{'mailindir'},
		Echolot::Config::get()->{'mailindir'}.'/cur',
		Echolot::Config::get()->{'mailindir'}.'/tmp',
		Echolot::Config::get()->{'mailindir'}.'/new',
		Echolot::Config::get()->{'mailerrordir'},
		Echolot::Config::get()->{'mailerrordir'}.'/cur',
		Echolot::Config::get()->{'mailerrordir'}.'/tmp',
		Echolot::Config::get()->{'mailerrordir'}.'/new'
	) {
		if ( ! -d $dir ) {
			mkdir ($dir, 0700) or
				croak ("Cannot create directory $dir: $!\n");
		};
	};
};












my $params;
Getopt::Long::config('bundling');
if (!GetOptions (
	'help'    =>  \$params->{'help'},
	'version' =>  \$params->{'version'},
	'verbose' =>  \$params->{'verbose'},
	'nohup'   =>  \$params->{'nohup'},
	'detach'  =>  \$params->{'detach'},
	'process' =>  \$params->{'process'},
	)) {
	die ("$PROGRAM_NAME: Usage: $PROGRAM_NAME [-fwhv]\n");
};
if ($params->{'help'}) {
    print ("Usage: $PROGRAM_NAME [options] command\n");
    print ("See man pingd or perldoc pingd for more info.\n");
    print ("echolot $VERSION - (c) 2002 Peter Palfrader <peter\@palfrader.org>\n");
    print ("http://savannah.gnu.org/projects/echolot/\n");
    exit 0;
};
if ($params->{'version'}) {
    print ("echolot $VERSION\n");
    print ("(c) 2002 Peter Palfrader <peter\@palfrader.org>\n");
    print ("http://savannah.gnu.org/projects/echolot/\n");
    exit 0;
};

my $COMMAND = shift @ARGV;
die ("command required\n") unless defined $COMMAND;


Echolot::Config::init( $params );
chdir( Echolot::Config::get()->{'homedir'} );
Echolot::Globals::init();


if ($COMMAND eq 'add' || $COMMAND eq 'delete') {
	command_adddelete($COMMAND, @ARGV);
	if (!$params->{'nohup'} && pid_exists()) {
		daemon_hup()
	} else {
		print "Don't forget to run $PROGRAM_NAME process.\n";
	};
} elsif ($COMMAND eq 'set') {
	command_set(@ARGV);
	if (!$params->{'nohup'} && pid_exists()) {
		daemon_hup()
	} else {
		print "Don't forget to run $PROGRAM_NAME process.\n";
	};
} elsif ($COMMAND eq 'setremailercaps') {
	command_setremailercaps(@ARGV);
	if (!$params->{'nohup'} && pid_exists()) {
		daemon_hup()
	} else {
		print "Don't forget to run $PROGRAM_NAME process.\n";
	};
} elsif ($COMMAND eq 'deleteremailercaps') {
	command_deleteremailercaps(@ARGV);
	if (!$params->{'nohup'} && pid_exists()) {
		daemon_hup()
	} else {
		print "Don't forget to run $PROGRAM_NAME process.\n";
	};
} elsif ($COMMAND eq 'getkeyconf') {
	Echolot::Commands::addCommand("getkeyconf");
	if (!$params->{'nohup'} && pid_exists()) {
		daemon_hup()
	} else {
		print "Don't forget to run $PROGRAM_NAME process.\n";
	};
} elsif ($COMMAND eq 'process') {
	daemon_hup();
} elsif ($COMMAND eq 'stop') {
	daemon_stop();
} elsif ($COMMAND eq 'start') {
	die ("Pidfile '".Echolot::Config::get()->{'pidfile'}."' exists\n")
		if pid_exists();
	make_dirs();
	if ($params->{'detach'}) {
		print "Detaching.\n";
		unless (fork()) {
			close STDOUT;
			close STDERR;
			open (STDOUT, ">>output") or die ("Cannot open 'output' as STDOUT\n");
			open (STDERR, ">&STDOUT") or die ("Cannot dup STDOUT as STDERR\n");
			close STDIN;
			$redirected_stdio = 1;
			print "Startup at ".scalar localtime().".\n";
			daemon_run();
			print "done at ".scalar localtime().".\n";
		};
	} else {
		daemon_run();
	};
} elsif ($COMMAND eq 'dumpconf') {
	Echolot::Config::dump();
} elsif ($COMMAND eq 'convert') {
	Echolot::Globals::initStorage();
	setSigHandlers();

	Echolot::Globals::get()->{'storage'}->convert();

	Echolot::Globals::get()->{'storage'}->commit();
	Echolot::Globals::get()->{'storage'}->finish();
} else {
	die ("Command $COMMAND unknown");
};

exit 0;

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