#!/usr/bin/perl
#
# $Id: loncontrol,v 1.34.2.1 2010/01/13 19:26:54 raeburn Exp $
#
# The LearningOnline Network with CAPA
#
# Copyright Michigan State University Board of Trustees
#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#
# LON-CAPA 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.
#
# LON-CAPA 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 LON-CAPA; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# /home/httpd/html/adm/gpl.txt
#
# http://www.lon-capa.org/
#
# Startup script for the LON-CAPA network processes
#

# chkconfig: 345 95 5
# description: LON-CAPA is a "network of knowledge".  It is used to \
# distribute knowledge resources and instructional management.
# processnames: lonc, lond, lonsql, lonmaxima
# pidfiles: /home/httpd/perl/logs/lon*.pid
# config: /etc/httpd/conf/loncapa.conf
# config: /home/httpd/lonTabs/hosts.tab
# config: /home/httpd/lonTabs/spare.tab
# SuSE chkconfig/insserv info
### BEGIN INIT INFO
# Provides:       loncapa
# Required-Start: mysql apache2 $network $remote_fs
# Required-Stop:
# Default-Start:  3 4 5
# Default-Stop:
# Description:    Starts the LON-CAPA services
### END INIT INFO

use strict;
use lib '/home/httpd/lib/perl/';
use LONCAPA::Configuration;

my $command=$ARGV[0]; $command=~s/[^a-z]//g;

$ENV{'PATH'}="/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin";
$ENV{'BASH_ENV'}="";

{ # Firewall variable scoping
    # Firewall code is based on the code in FC2 /etc/init.d/ntpd
    my $fw_chain = 'RH-Firewall-1-INPUT';
    my $iptables = '/sbin/iptables';
    if (! -e $iptables) {
	$iptables = '/usr/sbin/iptables';
	if (!-e $iptables) {
	    print("Unable to find iptables command\n");
	}
    }
    my $suse_config = "/etc/sysconfig/SuSEfirewall2";
    if (-e $suse_config) {
        $fw_chain = 'input_ext';
    } else {
        if (!-e '/etc/sysconfig/iptables') {
            print("Unable to find iptables file containing static definitions\n");
        }
    }
    if (-e $iptables) {
        my $count = `$iptables -L -n 2>/dev/null |grep $fw_chain |wc -l`;
        chomp($count);
        if (!$count) {
            $fw_chain ='INPUT';
        }
    }
    my $lond_port = &get_lond_port();
    if (!$lond_port) {
        print("Unable to determine lond port number from LON-CAPA configuration.\n");
    }

sub firewall_open_port {
    return 'inactive firewall' if (! &firewall_is_active);
    return 'port number unknown' if !$lond_port;
    my @opened;
    my $suse_config = "/etc/sysconfig/SuSEfirewall2";
    if (-e $suse_config) {
        if (open(my $fh,"<$suse_config")) {
            while(<$fh>) {
                chomp();
                if (/^FW_SERVICES_EXT_TCP="([^"]+)"\s*$/) {
                    my $portstr = $1;
                    my @suseports = split(/\s+/,$portstr);
                    foreach my $port ($lond_port) {
                        if (grep/^\Q$port\E$/,@suseports) {
                            push(@opened,$port);
                        }
                    }
                }
            }
        }
    } else {
        if (! `$iptables -L -n 2>/dev/null | grep $fw_chain | wc -l`) { 
            return 'chain error';
        }
        # iptables is running with our chain
        #
        # We could restrict the servers allowed to attempt to communicate
        # here, but the logistics of updating the /home/httpd/lonTabs/host.tab
        # file are likely to be a problem
        foreach my $port ($lond_port) {
            print "Opening firewall access on port $port.\n";
            my $result;
            my $firewall_command = 
                "$iptables -I $fw_chain -p tcp -d 0/0 --dport $port -j ACCEPT";
            system($firewall_command);
            my $return_status = $?>>8;
            if ($return_status == 1) {
                # Error
                print "Error opening port.\n";
            } elsif ($return_status == 2) {
                # Bad command
                print "Bad command error opening port.  Command was\n".
                      "  ".$firewall_command."\n";
            } elsif ($return_status == 0) {
                push(@opened,$port);
            }
        }
    }
    foreach my $port ($lond_port) {
        if (!grep(/^\Q$port\E$/,@opened)) {
            return 'Required port not open: '.$port."\n";  
        }
    }
    return 'ok';
}

sub firewall_is_port_open {
    my ($port) = @_;
    # returns 1 if the firewall port is open, 0 if not.
    #
    # check if firewall is active or installed
    return if (! &firewall_is_active);
    if (`$iptables -L -n 2>/dev/null | grep "tcp dpt:$port"`) { 
        return 1;
    } else {
        return 0;
    }
}

sub firewall_is_active {
    if (-e '/proc/net/ip_tables_names') {
        return 1;
    } else {
        return 0;
    }
}

sub firewall_close_port {
    return 'inactive firewall' if (! &firewall_is_active);
    return 'port number unknown' if !$lond_port;
    my $suse_config = "/etc/sysconfig/SuSEfirewall2";
    return if (-e $suse_config);
    foreach my $port ($lond_port) {
        print "Closing firewall access on port $port\n";
        my $firewall_command = 
            "$iptables -D $fw_chain -p tcp -d 0/0 --dport $port -j ACCEPT";
        system($firewall_command);
        my $return_status = $?>>8;
        if ($return_status == 1) {
            # Error
            print "Error closing port.\n";
        } elsif ($return_status == 2) {
            # Bad command
            print "Bad command error closing port.  Command was\n".
                "  ".$firewall_command."\n";
        } else {
            print "Port closed.\n";
        }
    }
    return;
}

sub get_lond_port {
    my $perlvarref=&LONCAPA::Configuration::read_conf();
    my $lond_port;
    if (ref($perlvarref) eq 'HASH') {
        if (defined($perlvarref->{'londPort'})) {
            $lond_port = $perlvarref->{'londPort'};
        }
    }
    return $lond_port;
}

} # End firewall variable scope

sub stop_daemon {
    my ($daemon,$killallname)=@_;
    my $pidfile="/home/httpd/perl/logs/$daemon.pid";
    
    printf("%-15s ",$daemon);
    if (-e $pidfile) {
	open(PIDFILE,$pidfile);
	my $daemonpid=<PIDFILE>;
	chomp($daemonpid);
	kill TERM => $daemonpid;
	my $count=0;
	while ($count++ < 5 && kill(0 => $daemonpid)) {
	    sleep 1;
	}
	if (kill 0 => $daemonpid) {
	    kill KILL => $daemonpid;
	    sleep 1;
	    if (kill 0 => $daemonpid) {
		print("failed to kill");
	    } else {
		print("killed");
	    }
	} else {
	    print("stopped");
	}
    } else {
	print("not running");
    }
    system("killall -q -0 $killallname");
    if ($? == 0) {
	system("killall -q $killallname");
	print(", killed off extraneous processes");
    }
    unlink($pidfile);
    print("\n");
}

sub clean_sockets {
    opendir(SOCKETS,"/home/httpd/sockets/");
    my $perlvarref=&LONCAPA::Configuration::read_conf();
    return if (ref($perlvarref) ne 'HASH');
    while (my $fname=readdir(SOCKETS)) {
	next if (-d $fname
		 || $fname=~/(mysqlsock|maximasock|\Q$perlvarref->{'lonSockDir'}\E)/);
	unlink("/home/httpd/sockets/$fname");
    }
}

if ($command eq "restart") {
    print 'Restarting LON-CAPA'."\n";
    print 'Ending LON-CAPA client and daemon processes'."\n";
    foreach my $daemon ('lonsql','lond','lonc','lonmemcached','lonmaxima') {
	my $killallname=$daemon;
	if ($daemon eq 'lonc') { $killallname='loncnew'; }
	&stop_daemon($daemon,$killallname);
    }
    print 'Starting LON-CAPA client and daemon processes (please be patient)'.
	"\n";
    system("su www -c '/home/httpd/perl/loncron --justcheckdaemons'");
} elsif ($command eq "stop") {
    print 'Stopping LON-CAPA'."\n";
    foreach my $daemon ('lonsql','lond','lonc','lonmemcached','lonmaxima') {
	my $killallname=$daemon;
	if ($daemon eq 'lonc') { $killallname='loncnew'; }
	&stop_daemon($daemon,$killallname);
    }
    my $firewall_result = &firewall_close_port();
    if ($firewall_result) {
        print "$firewall_result\n";
    }
    &clean_sockets();
} elsif ($command eq "start") {
    my $firewall_result = &firewall_open_port();
    if (($firewall_result eq 'ok') || ($firewall_result eq 'inactive firewall')) {
        if ($firewall_result eq 'inactive firewall') {
            print "WARNING: iptables firewall is currently inactive\n";
        }
        print 'Starting LON-CAPA'."\n";
        print 'Starting LON-CAPA client and daemon processes (please be patient)'.
	      "\n";
        system("su www -c '/home/httpd/perl/loncron --justcheckdaemons'");
    } else {
        print "Not starting LON-CAPA\n";
        if ($firewall_result eq 'port number unknown') {
            print "Could not check for status of LON-CAPA port in running firewall - port number unknown.  \n";
        } elsif ($firewall_result) {
            print "$firewall_result\n";
        }
    }
} elsif ($command eq "reload") {
    print 'Reload LON-CAPA config files'."\n";
    system("su www -c '/home/httpd/perl/loncron --justreload'");
} elsif ($command eq "status") {
    my $lond_port = &get_lond_port();
    my $response=`/bin/cat /home/httpd/perl/logs/*.pid 2>&1`;
    if ($response=~/No such file or directory/) {
	print 'LON-CAPA is not running.'."\n";
    } else {
	print 'LON-CAPA is running.'."\n";
	system("su www -c '/home/httpd/perl/loncron --justcheckconnections'");
    }
    if (! &firewall_is_active) {
        print 'The iptables firewall is not active'."\n";
    }
    my $lond_port = &get_lond_port();
    if ($lond_port) {
        if (&firewall_is_port_open($lond_port)) {
            print "The LON-CAPA port ($lond_port) is open in firewall.\n";
        } elsif (&firewall_is_active) {
            print "The LON-CAPA port ($lond_port) is NOT open in running firewall!\n";
        }
    } else {
        if (&firewall_is_active) {
            print "Could not check for status of LON-CAPA port in running firewall - port number unknown.\n";
        } else {
            print "LON-CAPA port number is unknown, and firewall is not running.\n";
        }
    }
} else {
    print "You need to specify one of restart|stop|start|status on the command line.\n";
}