#!/usr/bin/perl
=for comment

  Part of AREDN -- Used for creating Amateur Radio Emergency Data Networks
  Copyright (c) 2015 Darryl Quinn
  See Contributors file for additional contributors

  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 version 3 of the License.

  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, see <http://www.gnu.org/licenses/>.

  Additional Terms:

  Additional use restrictions exist on the AREDN(TM) trademark and logo.
    See AREDNLicense.txt for more info.

  Attributions to the AREDN Project must be retained in the source code.
  If importing this code into a new or existing project attribution
  to the AREDN project must be added to the source code.

  You must not misrepresent the origin of the material conained within.

  Modified versions must be modified to attribute to the original source
  and be marked in reasonable ways as differentiate it from the original
  version.

=cut
$debug = 0;
BEGIN {push @INC, '/www/cgi-bin'};
use perlfunc;
use ucifunc;
use tunfunc;

$VPNVER="1.0";
$config = nvram_get("config");
$node = nvram_get("node");
$node = "NOCALL" if $node eq "";
$unode = uc $node;   # UPPER CASE NODENAME
#$vpnconnfile = "/etc/vtun.connections";
#$tmpdir = "/tmp/web/vpn";
#$tmpvtundconf = "${tmpdir}/vtund.conf.tmp";
#$tmpvtundservice = "${tmpdir}/vtund.service.tmp";  # contains connection rows
#$tmpvtund = "${tmpdir}/vtund.tmp";
#$tmpconnfile = "${tmpdir}/vpnconnections";

read_postdata();
@active_tun=&get_active_tun();

#################
# page checks
#################
if($parms{button_reboot})
{
    system "/sbin/reboot";
} 

if($parms{button_install})
{
    install_vtun();
} 

reboot_required() if($config eq "" or -e "/tmp/reboot-required");
&vpn_setup_required("vpnc") unless(-e "/usr/sbin/vtund" );
 
#################
# If RESET or FIRST TIME, load servers into parms
#################

if($parms{button_reset} or not $parms{reload})
{
    # load connections from UCI
    &get_connection_info();
    
    # initialize the "add" entries to clear them
    foreach $var (qw(conn_add_enabled conn_add_host conn_add_passwd conn_add_netip))
    {
        $parms{$var} = "";
        $parms{$var} = "0" if($var eq 'conn_add_enabled');
    }
}

#################
# load connections from FORM and validate
#################
for($i =1 , @list = (); $i <= $parms{conn_num}; ++$i) { push @list, $i }
push @list, "_add";
$conn_num = 0;

foreach $val (@list)
{
    foreach $var (qw(enabled host passwd netip))
    {
        $varname = "conn${val}_$var";
        $parms{$varname} = "0" if($val eq "enabled" and $parms{$varname} eq "");
        $parms{$varname} = "" unless $parms{$varname};
        $parms{$varname} =~ s/^\s+//;
        $parms{$varname} =~ s/\s+$//;
        if($val ne "_add")
        {
            if($parms{$varname} eq "" and ($var eq "enabled"))
            {
                $parms{$varname} = "0"; 
            }
        }
        eval sprintf("\$%s = \$parms{%s}", $var, $varname);
    }


    # Validate ADDed values    
    if($val eq "_add")  { next unless ($enabled or $host or $passwd or $netip) and ($parms{conn_add} or $parms{button_save}) }
    else                { next if $parms{"conn${val}_del"} }

    # Validate password is vtun compliant
    # TODO

    if($val eq "_add" and $parm{button_save})
    {
        push @conn_err, "$val this connection must be added or cleared out before saving changes";
        next;
    }

    push @conn_err, "A connection server is required" if($host eq "");
    push @conn_err, "A connection password is required" if($passwd eq "");

    next if $val eq "_add" and @cli_err and $cli_err[-1] =~ /^$val /;

    # Commit the data for this connection
    ++$conn_num;

    $parms{"conn${conn_num}_enabled"} = $enabled;
    $parms{"conn${conn_num}_host"} = $host;
    $parms{"conn${conn_num}_passwd"} = $passwd;
    $parms{"conn${conn_num}_netip"} = $netip;

    # Clear out the ADD values
    if($val eq "_add")
    {
        foreach $var (qw(enabled host passwd netip))
            {
                $parms{"conn_add_${var}"} = "";
            }   
    }
}

#################
# SAVE the clients the UCI vtun file
#################
$parms{conn_num} = $conn_num;

if($parms{button_save} and not (@conn_err or @serv_err))
{
    # ADD/SET all server type entries
    for($i=1; $i<=$conn_num; $i++)
    {
        foreach $var (qw(enabled host passwd netip)) 
        {
            eval sprintf("\$val = \$parms{conn%s_%s}",$i,$var);
            $idx=$i*(-1);
            push(@errors,"Problem adding server entry into config file") if &uci_set_indexed_option("vtun","server",$idx,$var,$val);
        }
        # TODO: calculate clientip and serverip
        #
        # TODO: uci_set_indexed_option("vtun","server",-1,"clientip",$clientip);
        # TODO: uci_set_indexed_option("vtun","server",-1,"clientip",$serverip);
        # TODO: uci_set_indexed_option("vtun","server",-1,"node",$nodename)
    }

    push(@errors,"Problem committing server entry into config file") if system "uci commit vtun > /dev/null 2>&1";

    # COPY /etc/config/vtun to /etc/config.mesh/vtun (to workaround node-setup script issues)
    system "cp /etc/config/vtun /etc/config.mesh/vtun";

    # STOP vtun clients
    system "/etc/init.d/vtund stop > /dev/null 2>&1";
    
    # START VTUND  /etc/init.d/vtund start
    unless($debug == 3)
    {
        push(@errors,"Problem starting vtund") if system "/etc/init.d/vtund start > /dev/null 2>&1";
    }
}


######################################################################################
# generate the page
######################################################################################
http_header() unless $debug == 2;
html_header("$node setup", 1);

print "<body><center>\n";
print "<form method=post action=/cgi-bin/vpnc enctype='multipart/form-data'>\n" unless $debug == 2;
print "<form method=post action=test>\n" if $debug == 2;
print "<table width=790>\n";

#################
# Navigation bar
#################
print "<tr><td>\n";
navbar("vpnc");
print "</td></tr>\n";

#################
# control buttons
#################
print "<tr><td align=center>";
print "<a href='/help.html#vpn' target='_blank'>Help</a>";
print "&nbsp;&nbsp;&nbsp;\n";
print "<input type=submit name=button_save value='Save Changes' title='Save and use these settings now (takes about 20 seconds)'>&nbsp;\n";
print "<input type=submit name=button_reset value='Reset Values' title='Revert to the last saved settings'>&nbsp;\n";
print "<input type=submit name=button_refresh value='Refresh' title='Refresh this page'>&nbsp;\n";
print "<tr><td>&nbsp;</td></tr>\n";
push @hidden, "<input type=hidden name=reload value=1></td></tr>";

#################
# messages
#################
if(@cli_err)
{
    print "<tr><td align=center><b>ERROR:<br>";
    foreach(@conn_err) { print "$_<br>" }
    print "</b></td></tr>\n";
}

if($parms{button_save})
{
    if(@cli_err)
    {
	print "<tr><td align=center><b>Configuration NOT saved!</b></td></tr>\n";
    }
    elsif(@errors)
    {
	print "<tr><td align=center><b>Configuration saved, however:<br>";
	foreach(@errors) { print "$_<br>" }
	print "</b></td></tr>\n";
    }
    else
    {
	print "<tr><td align=center><b>Configuration saved and is now active.</b></td></tr>\n";
    }

    print "<tr><td>&nbsp;</td></tr>\n";
}

#################
# everything else
#################
if($config eq "mesh")
{
    print "<tr><td align=center valign=top>\n";
    &print_vpn_connections();
    print "</td></tr>\n";
    
    print "<tr><td><hr></td></tr>\n";
}
print "</table>\n";
print "<p style='font-size:8px'>VPN v${VPNVER}</p>";
push @hidden, "<input type=hidden name=conn_num value=$parms{conn_num}>";

#################
# add hidden form fields
#################
foreach(@hidden) { print "$_\n" }

#################
# close the form
#################
print "</form></center>\n";
show_debug_info();

#################
# close the html
#################
print "</body></html>\n";
exit;


##################
# page subsections
##################


######################################################
# List the connections to be made from this client
######################################################
sub print_vpn_connections()
{
    print "<table id=connection_section cellpadding=0 cellspacing=0>";
    print "<tr><th colspan=6>Connect this node to the following servers:</th></tr>";
    print "<tr><th colspan=6><hr></th></tr>\n";
    print "<tr><th>Enabled?</th><th>Server</th><th>Pwd</th><th>Network</th><th>Active&nbsp;</th><th>Action</th></tr>\n";

    for($i = 1, @list = (); $i <= $parms{conn_num}; ++$i) { push @list, $i };

    push @list, "_add" unless($parms{conn_num} > 9);

    $cnum=0;
    foreach $val (@list)
    {
        foreach $var (qw(enabled host passwd netip))
        {
            eval sprintf("\$%s = \$parms{conn%s_%s}", $var, $val, $var);
        }

        print "<tr><td height=10></td></tr>\n" if $val eq "_add" and scalar(@list) > 1;
        print "<tr>";
        print "<td>";

        # Required to be first, so, if the checkbox is cleared, a value will still POST
        print "<input type='hidden' name='conn${val}_enabled' value='0'>" unless($val eq "_add");
        print "<input type='checkbox' name='conn${val}_enabled' value='1'";
        print " onChange='form.submit()'" unless $val eq "_add";
        print " checked='checked'" if $enabled;
        #print " disabled" unless $val eq "_add";
        print " title='enable this connection'></td>";
 
        print "<td><input type=text size=25 name=conn${val}_host value='$host'";
        print " onChange='form.submit()'" unless $val eq "_add";
        # print " disabled" unless $val eq "_add";
        print " title='connection name'></td>";

        print "<td>&nbsp;&nbsp;<input type=text size=20 name=conn${val}_passwd value='$passwd' ";
        print " onChange='form.submit()'" unless $val eq "_add";
        print " title='connection password'";
        #print " disabled" unless $val eq "_add";
        print "></td>";

        print "<td>&nbsp;&nbsp;<input type=text size=14 name=conn${val}_netip value='$netip'";
        print " onChange='form.submit()'" unless $val eq "_add";
        # print " disabled" unless $val eq "_add";
        print " title='connection network'></td>";

        #if($val eq "_add") { print @netw[3]+(($net) * 4); }
        #else { print @netw[3]+($net * 4); }
        
        #print @netw[3]+($net * 4) unless $val eq "_add";
        print "</td>";
        print "<td>&nbsp;";
        #print "<img src='/dot.png'/>" if(@active_tun[$cnum]);  
        print "<img src='/dot.png'/>" if((&is_tunnel_active($netip, @active_tun)) && ($val ne "_add"));
        print "</td>";
        print "<td>&nbsp;";    

        print "<input type=submit name=";
        if($val eq "_add")  { print "conn_add value=Add title='Add this connection'" }
        else                { print "conn${val}_del value=Del title='Delete this connection'" }
        print "></td></tr>\n";

        # display any errors
        while(@conn_err and $conn_err[0] =~ /^$val /)
        {
            $err = shift @conn_err;
            $err =~ s/^\S+ //;
            print "<tr><th colspan=4>$err</th></tr>\n";
        }

        #push @hidden, "<input type='hidden' name='client${val}_enable' value='0'>" unless($val eq "_add");
        
        print "<tr><td colspan=6 height=4></td></tr>\n";
        $cnum++;
    }
    print "</table>\n";
}


#################################
# generate the UCI file
#################################
sub build_uci()
{
    
    # loop over each connection
    #$cnum=0;
    foreach(`cat $vpnconnfile 2>/dev/null`)
    {
        next if /^\s*#/;   ## ignore lines that start with '#'
        next if /^\s*$/;   ## ignore lines that start with '$'
        chomp;

        @parts = split /\|/, $_;
        
        next unless scalar(@parts) == 4;

        $enable = @parts[0];
        $server = @parts[1];
        $pass = @parts[2];
        $net = @parts[3];

        @netw=split /\./, $net;

        unless($enable)
        {
            # $cnum++;    ## to make sure the tun and ip addresses remain constant
            next;
        }
        $clientname=sprintf("%s-%d-%d-%d-%d",$unode,@netw[0],@netw[1],@netw[2],@netw[3]);
        $net3=@netw[2];
        #$net4=@netw[3]+($cnum*4);
        $net4=@netw[3];
        $netnet=sprintf("%d.%d.%d.%d",@netw[0],@netw[1],$net3,$net4);
        $netcli=sprintf("%d.%d.%d.%d",@netw[0],@netw[1],$net3,$net4+1);
        $netserv=sprintf("%d.%d.%d.%d",@netw[0],@netw[1],$net3,$net4+2);

        # uci set vtun.@server[-1].host
        # uci set vtun.@server[-1].node
        # uci set vtun.@server[-1].passwd
        # uci set vtun.@server[-1].netip
        # uci commit vtun

        $cnum++;
    }    
}

#################################
# load server connection info from UCI
#################################
sub get_connection_info()
{
    my @connections=&uci_get_all_by_sectiontype("vtun","server");
    foreach $c (0..@connections-1)
    {
        foreach $var (qw(enabled host passwd netip))
        {
            $parms{"conn${c}_$var"} = @connections[$c]->{$var};
            $parms{"conn${c}_$var"} = "0" if($parms{"conn${c}_$var"} eq "");
        }
    }

    $parms{conn_num} = scalar(@connections);
}


sub DEBUGEXIT()
{
    my ($text) = @_;
    http_header();
    html_header("$node setup", 1);
    print "DEBUG[";
    print $text;
    print "]</body>";
    exit;
}