#!/usr/bin/perl

#
# Guillaume Cottenceau (gc@mandrakesoft.com)
#
# Copyright 2000, 2001, 2002 MandrakeSoft
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2, as
# published by the Free Software Foundation.
#
# 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#

use lib qw(/usr/lib/libDrakX);

use standalone;     #- warning, standalone must be loaded very first, for 'explanations'

use common;
use detect_devices;
use interactive;
use network;
use log;
use c;
use network::netconnect;

$::isInstall and die "Not supported during install.\n";


local $_ = join '', @ARGV;

/-h/ and die "usage: drakgw [--version]\n";
/-version/ and die 'version: $Id$ '."\n";
$::Wizard_pix_up = "wiz_drakgw.png";
$::Wizard_title = _("Internet Connection Sharing");
$::direct = /-direct/;


my $sysconf_network = "/etc/sysconfig/network";
my $sysconf_dhcpd = "/etc/sysconfig/dhcpd";
my $rc_firewall_generic = "/etc/rc.d/rc.firewall";
my $rc_firewall_drakgw = "/etc/rc.d/rc.firewall.inet_sharing";
my $rc_firewall_24 = "/etc/rc.d/rc.firewall.inet_sharing-2.4";
my $dhcpd_conf = "/etc/dhcpd.conf";
my $cups_conf = "/etc/cups/cupsd.conf";
my $drakgw_setup = "/etc/sysconfig/inet_sharing";


my $in = 'interactive'->vnew('su', 'default');

!$::isEmbedded && $in->isa('interactive::gtk') and $::isWizard=1;

pur_gtk_mode() if $::isEmbedded && $in->isa('interactive::gtk');

sub sys { system(@_) == 0 or log::l("[drakgw] Warning, sys failed for $_[0]") }

sub outpend { 
    standalone::explanations("modified file $_[0]");
    my $f = shift; local *F; open F, ">>$f" or die "outpend in file $f failed: $!\n"; print F foreach @_;
}

sub start_daemons ()
{
    my $cups_used = 0;
    standalone::explanations("Starting daemons");
    if (-f "/etc/rc.d/init.d/cups") {
        if (system("/etc/rc.d/init.d/cups status >/dev/null") == 0) {
           $cups_used = 1;
           sys("/etc/rc.d/init.d/cups stop");
        }
    }
    system("/etc/rc.d/init.d/dhcpd status >/dev/null") == 0 and sys("/etc/rc.d/init.d/dhcpd stop");
    system("/etc/rc.d/init.d/named status >/dev/null 2>/dev/null") == 0 and sys("/etc/rc.d/init.d/named stop");

    my $netmon = '/usr/sbin/net_monitor';
    my $netmon_need_start;
    if (-x $netmon && `$netmon --status` eq 1) {
	$netmon_need_start = 1;
	system("$netmon --disconnect --force --quiet >/dev/null");
    }
    sys("/etc/rc.d/init.d/network restart");
    $netmon_need_start and system("$netmon --connect --force --quiet >/dev/null");

    sys("sh $rc_firewall_generic");

    sys("/etc/rc.d/init.d/$_ start"), sys("/sbin/chkconfig --level 345 $_ on") foreach 'named', 'dhcpd';
    sys("/etc/rc.d/init.d/cups start") if $cups_used;

    substInFile { s/^INET_SHARING.*\n//; $_ .= "INET_SHARING=enabled\n" if eof } $drakgw_setup;
}

sub stop_daemons ()
{
    standalone::explanations("Stopping daemons");
    system("/etc/rc.d/init.d/dhcpd status >/dev/null") == 0 and sys("/etc/rc.d/init.d/dhcpd stop");
    system("/etc/rc.d/init.d/named status >/dev/null 2>/dev/null") == 0 and sys("/etc/rc.d/init.d/named stop");
    sys("/sbin/iptables -t nat -F");
    sys("/sbin/chkconfig --level 345 $_ off") foreach 'named', 'dhcpd';

    substInFile { s/^INET_SHARING.*\n//; $_ .= "INET_SHARING=disabled\n" if eof } $drakgw_setup;
}

sub fatal_quit ($)
{
    log::l("[drakgw] FATAL: $_[0]");
    undef $wait_configuring;
    $in->ask_warn('', $_[0]);
    quit_global($in, -1);
}

my ($kernel_version) = c::kernel_version() =~ /(...)/;
log::l("[drakgw] kernel_version $kernel_version");

$kernel_version eq '2.4' or fatal_quit(_("Sorry, we support only 2.4 kernels."));


begin:

#- **********************************
#- * 0th step: verify if we are already set up

if (-f $drakgw_setup) {
    $::Wizard_no_previous = 1;

    if (grep(/enabled/, cat_($drakgw_setup))) {
	my $r = $in->ask_from_list_(_("Internet Connection Sharing currently enabled"),
_("The setup of Internet connection sharing has already been done.
It's currently enabled.

What would you like to do?"),
				   [ __("disable"), __("reconfigure"), __("dismiss") ]) or quit_global($in, 0);
	if ($r eq "disable") {
	    {
		my $wait_disabl = $in->wait_message('', _("Disabling servers..."));
		stop_daemons();
	    }
	    foreach ($dhcpd_conf, $rc_firewall_24) {
		renamef($_, "$_.drakgwdisable") or die "Could not rename $_ to $_.drakgwdisable" 
	    }
	    log::l("[drakgw] Disabled");
	    $::Wizard_finished = 1;
	    $in->ask_okcancel('', _("Internet connection sharing is now disabled."));
	    quit_global($in, 0);
	}
	if ($r eq "dismiss") {
	    quit_global($in, 0);
	}
    }
    elsif (grep(/disabled/, cat_($drakgw_setup)))
    {
	my $r = $in->ask_from_list_(_("Internet Connection Sharing currently disabled"),
_("The setup of Internet connection sharing has already been done.
It's currently disabled.

What would you like to do?"),
				   [ __("enable"), __("reconfigure"), __("dismiss") ]);
	if ($r eq "enable") {
	    foreach ($dhcpd_conf, $rc_firewall_24) {
		rename($_, "$_.old") if -f $_;
		rename("$_.drakgwdisable", $_) or die "Could not find configuration. Please reconfigure.";
	    }
	    {
		my $wait_enabl = $in->wait_message('', _("Enabling servers..."));
		start_daemons();
	    }
            log::l("[drakgw] Enabled");
	    $::Wizard_finished = 1;
	    $in->ask_okcancel('', _("Internet connection sharing is now enabled."));
	    quit_global($in, 0);
	}
	if ($r eq "dismiss") {
	    quit_global($in, 0);
	}
    }
    else {
	log::l("[drakgw] Warning, unrecognized config file, ignoring");
	renamef($drakgw_setup, "$drakgw_setup.unrecognized");
    }
}


#- **********************************
#- * 1st step: detect/setup
step_ask_confirm:

$::Wizard_no_previous = 1;
    
$::direct or $in->ask_okcancel(_("Internet Connection Sharing"),
_("You are about to configure your computer to share its Internet connection.
With that feature, other computers on your local network will be able to use this computer's Internet connection.

Note: you need a dedicated Network Adapter to set up a Local Area Network (LAN)."), 1) or quit_global($in, 0);

undef $::Wizard_no_previous;


step_detectsetup:

my @configured_devices = map { /ifcfg-(\S+)/ } glob('/etc/sysconfig/network-scripts/ifcfg*');

my %aliased_devices; 
/^\s*alias\s+(eth[0-9])\s+(\S+)/ and $aliased_devices{$1} = $2 foreach cat_("/etc/modules.conf");

my $card_netconnect = network::netconnect::get_net_device();
defined $card_netconnect and log::l("[drakgw] Information from netconnect: ignore card $card_netconnect");

my @cards = grep {
    log::l("[drakgw] Have network card: $_");
    $_ ne $card_netconnect
} detect_devices::getNet();
log::l("[drakgw] Available network cards: ", join(", ", @cards));

my $format = sub {
    $aliased_devices{$_[0]} ?
      _("Interface %s (using module %s)", $_[0], $aliased_devices{$_[0]}) :
      _("Interface %s", $_[0]);
};

#- setup the network interface we shall use

my $device;
if (!@cards)
{
    $in->ask_warn(_("No network adapter on your system!"), 
		  _("No ethernet network adapter has been detected on your system. Please run the hardware configuration tool."));
    quit_global($in, 0);
}
elsif (@cards == 1)
{
    $device = $cards[0];
    $in->ask_okcancel(_("Network interface"),
_("There is only one configured network adapter on your system:

%s

I am about to setup your Local Area Network with that adapter.", $format->($device)), 1) or goto step_ask_confirm;
}
else
{
    $device = $in->ask_from_listf(_("Choose the network interface"),
				    _("Please choose what network adapter will be connected to your Local Area Network."),
				     $format,
				    \@cards,
				    ) or goto step_ask_confirm;
    defined $device or quit_global($in, 0);
}
standalone::explanations("Choosing network device: $device");


my $lan_address = "192.168.0.0";
my $server_ip = "192.168.0.1";

my $reconf_dhcp_server_intf = 1;

if (grep(/$device/, @configured_devices)) {
  step_warning_already_conf:
    my $auto = _('Yes');
    my $conf = network::read_interface_conf("/etc/sysconfig/network-scripts/ifcfg-$device");
    $in->ask_from(_("Network interface already configured"),
		  _("Warning, the network adapter (%s) is already configured.

Do you want an automatic re-configuration?

You can do it manually but you need to know what you're doing.", $device),
		  [ { label => _("Automatic reconfiguration"), val => \$auto, list => [ _('Yes'), _('No (experts only)') ] },
		    { val => _("Show current interface configuration"), clicked =>
		      sub { $in->ask_warn(_('Current interface configuration'),
					  _("Current configuration of `%s':

Network: %s
IP address: %s
IP attribution: %s
Driver: %s", $device, $conf->{NETWORK}, $conf->{IPADDR}, $conf->{BOOTPROTO}, $aliased_devices{$device} || '(unknown)')) } } ]) or goto step_detectsetup;
    
    if ($auto ne _('Yes')) {
	$reconf_dhcp_server_intf = 0;
	$server_ip = $conf->{IPADDR};
	$lan_address = $conf->{NETWORK};
	$in->ask_from('',
		      _("I can keep your current configuration and assume you already set up a DHCP server; in that case please verify I correctly read the C-Class Network that you use for your local network; I will not reconfigure it and I will not touch your DHCP server configuration.

Else, I can reconfigure your interface and (re)configure a DHCP server for you.

", $device),
		      [ { label => _("C-Class Local Network"), val => \$lan_address, type => 'entry' },
			{ label => _("(This) DHCP Server IP"), val => \$server_ip, type => 'entry' },
			{ label => _("Re-configure interface and DHCP server"), val => \$reconf_dhcp_server_intf, type => 'bool' } ])
	  or goto step_warning_already_conf;
    }
}
    
if (!($lan_address =~ s/\.0$//)) {
    $in->ask_warn('', 
		  _("The Local Network did not finish with `.0', bailing out."));
    quit_global($in, 0);
}
standalone::explanations("Using LAN address <$lan_address>");


#- test for potential conflict with other networks

foreach (grep { $_ ne $device } @configured_devices)
{
    grep(/$lan_address/, cat_("/etc/sysconfig/network-scripts/ifcfg-$_")) and
      ($in->ask_warn('', _("Potential LAN address conflict found in current config of %s!\n", $_)) or goto step_detectsetup);
}


#- test for potential conflict with previous firewall config

system('modprobe iptable_nat');
if (-f '/etc/sysconfig/iptables' || -x '/sbin/iptables' && listlength(`/sbin/iptables -t nat -nL`) > 8) {
    $in->ask_okcancel(_("Firewalling configuration detected!"),
		      _("Warning! An existing firewalling configuration has been detected. You may need some manual fix after installation.")) or goto step_detectsetup;
}


#- **********************************
#- * 2nd step: configure

$wait_configuring = $in->wait_message(_("Configuring..."), 
				      _("Configuring scripts, installing software, starting servers..."));


#- setup the /etc/sysconfig/network-script/ script

if ($reconf_dhcp_server_intf) {
    standalone::explanations("Reconfiguring network parameters of $device");
    my $network_scripts = "/etc/sysconfig/network-scripts";
    my $ifcfg = "$network_scripts/ifcfg-$device";
    renamef($ifcfg, "$network_scripts/old.ifcfg-$device");
    output($ifcfg, qq(DEVICE=$device
BOOTPROTO=static
IPADDR=$server_ip
NETMASK=255.255.255.0
NETWORK=$lan_address.0
BROADCAST=$lan_address.255
ONBOOT=yes
));
}


#- install and setup the RPM packages

my $rpms_to_install;
my %rpm2file = (iptables => '/sbin/iptables',
		 'dhcp-server' => '/usr/sbin/dhcpd',
		 bind => '/usr/sbin/named',
		 'caching-nameserver' => '/var/named/named.local');

#- first: try to install all in one step
my @needed_to_install = grep { !-e $rpm2file{$_} } keys %rpm2file;
@needed_to_install and $in->do_pkgs->install(@needed_to_install);
#- second: try one by one if failure detected
if (grep { !-e $rpm2file{$_} } keys %rpm2file) {
    foreach (keys %rpm2file) {
	-e $rpm2file{$_} or $in->do_pkgs->install($_);
	-e $rpm2file{$_} or fatal_quit(_("Problems installing package %s", $_));
    }
}


#- setup the masquerading configuration
standalone::explanations("Modifying firewalling configuration");
if (!-f $rc_firewall_generic) {
    output($rc_firewall_generic, "#!/bin/sh
#
# Automatically generated by drakgw
[ -x $rc_firewall_drakgw ] && $rc_firewall_drakgw
");
    chmod 0700, $rc_firewall_generic;
}
elsif (!grep(/drakgw/, cat_($rc_firewall_generic))) {
    outpend($rc_firewall_generic, "
# Automatically added by drakgw
[ -x $rc_firewall_drakgw ] && $rc_firewall_drakgw

");
}

output($rc_firewall_drakgw, sprintf(<<'EOF', $rc_firewall_24, $rc_firewall_24));
#!/bin/sh
KERNELMAJ=`uname -r | sed                   -e 's,\..*,,'`
KERNELMIN=`uname -r | sed -e 's,[^\.]*\.,,' -e 's,\..*,,'`

if [ "$KERNELMAJ" -eq 2 -a "$KERNELMIN" -eq 4 ]; then
    [ -x %s ] && %s
fi
EOF

chmod 0700, $rc_firewall_drakgw;


output($rc_firewall_24, qq(#!/bin/sh
# Load the NAT module (this pulls in all the others).
modprobe iptable_nat

# Turn on IP forwarding
echo 1 > /proc/sys/net/ipv4/ip_forward

# In the NAT table (-t nat), Append a rule (-A) after routing (POSTROUTING)
# which says to MASQUERADE the connection (-j MASQUERADE).
/sbin/iptables -t nat -A POSTROUTING -s $lan_address.0/24 -j MASQUERADE

# Allows forwarding specifically to our LAN
/sbin/iptables -A FORWARD -s $lan_address.0/24 -j ACCEPT

# Allow dhcp requests
/sbin/iptables -A INPUT -i $device -p udp --sport bootpc --dport bootps -j ACCEPT
/sbin/iptables -A INPUT -i $device -p tcp --sport bootpc --dport bootps -j ACCEPT
/sbin/iptables -A INPUT -i $device -p udp --sport bootps --dport bootpc -j ACCEPT
/sbin/iptables -A INPUT -i $device -p tcp --sport bootps --dport bootpc -j ACCEPT

# Allow dns requests
/sbin/iptables -A INPUT -i $device -p udp --dport domain -j ACCEPT
/sbin/iptables -A INPUT -i $device -p tcp --dport domain -j ACCEPT
));
chmod 0700, $rc_firewall_24;


#- be sure that FORWARD_IPV4 is enabled in /etc/sysconfig/network

substInFile { s/^FORWARD_IPV4.*\n//; $_ .= "FORWARD_IPV4=true\n" if eof } $sysconf_network;


#- setup the DHCP server

if ($reconf_dhcp_server_intf) {
    standalone::explanations("Configuring a DHCP server on $lan_address.0");
    renamef($dhcpd_conf, "$dhcpd_conf.old");
    output($dhcpd_conf, qq(subnet $lan_address.0 netmask 255.255.255.0 {
	# default gateway
	option routers $server_ip;
	option subnet-mask 255.255.255.0;

	option domain-name "homelan.org";
	option domain-name-servers $server_ip;

	range dynamic-bootp $lan_address.16 $lan_address.253;
	default-lease-time 21600;
	max-lease-time 43200;
}
));
}

my $update_dhcp = '/usr/sbin/update_dhcp.pl';
-e $update_dhcp and system($update_dhcp);


#- put the interface for the dhcp server in the sysconfig-dhcp config, for the /etc/init.d script of dhcpd

substInFile { s/^INTERFACES\n//; $_ .= "INTERFACES=\"$device\"\n" if eof } $sysconf_dhcpd;


#- Set up /etc/cups/cupsd.conf to make the broadcasting of the printer info
#- working correctly: 
#- 
#-  1. ServerName <server's IP address>  # because clients do necessarily 
#-                                       # know the server's name
#-
#-  2. BrowseAddress <server's Broadcast IP> # broadcast printer info into
#-                                           # the local network.
#-
#-  3. BrowseOrder Deny,Allow
#-     BrowseDeny All
#-     BrowseAllow <IP mask for local net> # Only accept broadcast signals 
#-                                         # coming from local network
#-
#-  4. <Location />
#-     Order Deny,Allow
#-     Deny From All
#-     Allow From <IP mask for local net> # Allow only machines of local 
#-     </Location>                        # network to access the server
#-     
#- These steps are only done when the CUPS package is installed.

#- Modify the root location block in /etc/cups/cupsd.conf

if (-f $cups_conf) {
    standalone::explanations("Updating CUPS configuration accordingly");

    substInFile {
        s/^ServerName[^:].*\n//; $_ .= "ServerName $server_ip\n" if eof;
        s/^BrowseAddress.*\n//; $_ .= "BrowseAddress $lan_address.255\n" if eof;
        s/^BrowseOrder.*\n//; $_ .= "BrowseOrder Deny,Allow\n" if eof;
        s/^BrowseDeny.*\n//; $_ .= "BrowseDeny All\n" if eof;
        s/^BrowseAllow.*\n//; $_ .= "BrowseAllow $lan_address.*\n" if eof;
    } $cups_conf;

    my @cups_conf_content = cat_($cups_conf);
    my @root_location; my $root_location_start; my $root_location_end;

    # Cut out the root location block so that it can be treated seperately
    # without affecting the rest of the file
    if (grep(m|^\s*<Location\s+/\s*>|, @cups_conf_content)) {
	$root_location_start = -1;
	$root_location_end = -1;
	# Go through all the lines, bail out when start and end line found
	for (my $i = 0; $i < @cups_conf_content && $root_location_end == -1; $i++) {
	    if ($cups_conf_content[$i] =~ m|^\s*<\s*Location\s+/\s*>|) {
		$root_location_start = $i;
	    } elsif (($cups_conf_content[$i] =~ m|^\s*<\s*/Location\s*>|) && ($root_location_start != -1)) {
		$root_location_end = $i;
	    }
	}
	# Rip out the block and store it seperately
	@root_location = splice(@cups_conf_content, $root_location_start, $root_location_end - $root_location_start + 1);
    } else {
	# If there is no root location block, create one
	$root_location_start = @cups_conf_content;
	@root_location = ("<Location />\n", "</Location>\n");
    }
 
    # Delete all former "Order", "Allow", and "Deny" lines from the root location block
    s/^\s*Order.*//, s/^\s*Allow.*//, s/^\s*Deny.*// foreach @root_location;
 
    # Add the new "Order" and "Deny" lines, add an "Allow" line for the local network
    splice(@root_location, -1, 0, $_) foreach ("Order Deny,Allow\n", "Deny From All\n", "Allow From 127.0.0.1\n",
					       "Allow From $lan_address.*\n");
 
    # Put the changed root location block back into the file
    splice(@cups_conf_content, $root_location_start, 0, @root_location);
 
    output $cups_conf, @cups_conf_content;
}


#- start the daemons

substInFile { s/^INTERFACE.*\n//; $_ .= "INTERFACE=$device\n" if eof } $drakgw_setup;
start_daemons();


#- bye-bye message

undef $wait_configuring;

$::Wizard_no_previous = 1;
$::Wizard_finished = 1;

$in->ask_okcancel(_("Congratulations!"), 
_("Everything has been configured.
You may now share Internet connection with other computers on your Local Area Network, using automatic network configuration (DHCP)."));


log::l("[drakgw] Installation complete, exiting");
quit_global($in, 0);

sub quit_global {
    my ($in, $exitcode) = @_;
    $in->exit($exitcode);
    goto begin
}

sub pur_gtk_mode
{
    require Gtk;
    init Gtk;
    my $setup_state = grep(/disabled/, cat_($drakgw_setup)) ? _("The setup has already been done, but it's currently disabled.") :
                      grep(/enabled/, cat_($drakgw_setup))  ? _("The setup has already been done, and it's currently enabled.") :
                      _("No Internet Connection Sharing has ever been configured.");
    
    my $window1 = $::isEmbedded ? new Gtk::Plug ($::XID) : new Gtk::Window -toplevel;
    $window1->signal_connect(delete_event => sub { Gtk->exit(0) });
    $window1->set_position(1);
    $window1->set_title(_("Internet connection sharing configuration"));
    $window1->border_width(10);
    my $vbox1 = new Gtk::VBox(0,0);
    $window1->add($vbox1);
    my $hbox1 = new Gtk::HBox(0,0);
    $vbox1->pack_start($hbox1,1,1,0);
    my $label1 = new Gtk::Label(
_("Welcome to the Internet Connection Sharing utility!

%s

Click on Configure to launch the setup wizard.", $setup_state));
    $hbox1->pack_start($label1,1,1,0);
    my $hbox2 = new Gtk::HBox(0,0);
    $vbox1->pack_start($hbox2,1,1,0);
    
    my $bbox1 = new Gtk::HButtonBox;
    $vbox1->pack_start($bbox1,0,0,0);
    $bbox1->set_layout(-end);
    my $button_conf = new Gtk::Button _("Configure");
    $button_conf->signal_connect(clicked => sub {
				       system("/usr/sbin/drakgw --wizard");
				       kill(USR1, $::CCPID);
				   });
    $bbox1->add($button_conf);
    my $button_cancel = new Gtk::Button _("Cancel");
    $button_cancel->signal_connect(clicked => sub {
					 kill(USR1, $::CCPID);
				     });
    $bbox1->add($button_cancel);
    $window1->show_all();
    Gtk->main_iteration while Gtk->events_pending;
    $::isEmbedded and kill USR2, $::CCPID;
    Gtk->main;
    Gtk->exit(0);
    
}