#!/usr/bin/perl5

# dhcp-relay.cgi
#
# To determine that dhcp_relay is currently enabled, the uncommented line
# must exist in inetd.conf and chkconfig proclaim_relayagent must be on.
#
# To enable, both the above are set, and a sig HUP is sent.
#
# To disable, the line is commented and chkconfig p... is set off and sig 
# HUP sent. 

use CGI;
require "/usr/OnRamp/lib/OnRamp.pm";

$title = "DHCP Relay Agent";

$query = new CGI;
print $query->header;

$help = $ENV{"DOCUMENT_ROOT"} . $ENV{"SCRIPT_NAME"};
$help =~ s/cgi$/hlp/;
exec $help if ($query->param('help') eq "Help");

&title_block($title);


$def_config_dir = "/var/dhcp/config";
$rly_off = system ("/etc/chkconfig", "proclaim_relayagent");
$srv_off = system ("/etc/chkconfig", "proclaim_server");
$def_rstate = "No";
if ($rly_off == 0) {
    $def_rstate = "Yes";
}
$inetd_cf = "/etc/inetd.conf";
$dummy = "/etc/inetd.conf.tmp";

# Only look at the option file name in /etc/inetd.conf if the server is
# enabled, also need to process it then.
if ($rly_off == 0) {	# chkconfig proclaim_relayagent is on
    open(INETD, $inetd_cf) || &error("Cannot open $inetd_cf");
    while (<INETD>) {
	if (/^#/) {
	    next;
	}
	# bootp dgram udp wait root /usr/etc/dhcp_relay dhcp_relay -o <file>
	if (/^bootp/) {
	    chop;
	    @entlist = split(/\s+/);
	    if (($entlist[6] eq "dhcp_relay") && ($entlist[7] eq "-o")) {
		$osf = $entlist[8];
		last;	# Break out of the while loop
	    }
	}
    }
    close(INETD);
}

if (($rly_off == 0) && $osf) {
    open(OPTIONS, $osf) || &error("Cannot open $osf");
    while(<OPTIONS>) {
	if (/^#/) {
	    next;
	}
	chop;
	@optlist = split(/\s+/);
	$i = 0;
	while ($optlist[$i]) {
	    if ($optlist[$i] eq "-c") {
		$def_config_dir = $optlist[$i+1];
		$i += 2;
		next;
	    }
	    else {
		print $err_start,
		      "Unknown Option $optlist[$i] in the <b>$osf</b> file.";
	    }
	    $i++;
	}
    }
    close(OPTIONS);
}
else {
    $osf = "/etc/config/dhcp_relay.options";
}

$srvlist_file = $def_config_dir."\/dhcp_relay.servers";

open(SRVLST, $srvlist_file) || &error("Cannot open $srvlist_file");
$i = 0;
while (<SRVLST>) {
    if (/^#/) {
	next;
    }
    chop;
    $_ =~ s/^\s+//;
    $_ =~ s/\s+$//;
    $server_list[$i] = $_;
    $i++;
}
close(SRVLST);

undef @new_list;

$addServer = 0;
$delServer = 0;

if ($query->param) {
    if ($query->param('add') eq 'Add New Server') {
	$addList = $query->param('add_list');
	&formValid_add;
	$message = qq|Click "Ok" to save changes.|;
	$query->param('add_list','');
	&generic($addList,1);
	exit 0;
    }

    if ($query->param('delete') eq 'Delete Existing Server') {
	$delList = $query->param('chosen');
	&error("To delete an existing server, first select one from
	    the list, then click the delete button.") if !$delList;
	$delList =~ /(\w+)/;
	$delList = $1;
	$message = qq|Click "Ok" to save changes.|;
	&generic($delList,2);
	exit 0;
    }

    if ($query->param('doit') eq 'Ok') {
	if ($query->param('addName')) { 
	    push(@server_list,$query->param('addName'));
	    &saveList;
	    $message = "Server added."; 
	}
	if ($query->param('delName')) {
	    $delName = $query->param('delName');
	    undef @temp_list;
	    foreach $arg (@server_list) {
		if ($arg ne $delName) { push(@temp_list,$arg); }
	    }
	    @server_list = @temp_list;
	    &saveList; 
	    $message = "Server deleted."; 
	}

	$new_rstate = $query->param(rstate);

	if ($new_rstate ne $def_rstate) {	# State Changed
	    # Need to make sure that DHCP Server is disabled
	    if ($new_rstate eq "Yes") {
		# chkconfig on, the system WILL ship with the inetd.conf entry
		# for dhcp_bootp enabled
		if ($srv_off == 0) {
		    &error("You Need to Disable the DHCP Server before you
			can enable the DHCP Relay Agent.");
		}
		system ("/etc/chkconfig", "proclaim_relayagent", "on");
		&checkForInetd;
		$message .= "  DHCP relay agent enabled.";
    	    }
	    else {
		# chkconfig off
		system ("/etc/chkconfig", "proclaim_relayagent", "off");
		&commentInetd;
		$message .= "  DHCP relay agent disabled.";
	    }
	    `/etc/killall -HUP inetd`;
	}
	if (!$message) { $message = "No changes made."; }
    }
}

sub commentInetd {
    open(IN,"< $inetd_cf");
    open(OUT,"> $dummy");
    while(<IN>) {
	@items = split(/\s+/);
	if ($items[0] eq "bootp" && $items[6] eq "dhcp_relay") {
	    print OUT "# $_";
	} else { print OUT $_; }
    }
    close(IN);
    close(OUT);
    rename($dummy,$inetd_cf);
}    

sub checkForInetd {
    $line = "bootp\tdgram\tudp\twait\troot\t/usr/etc/dhcp_relay ".
		"dhcp_relay -o /etc/config/dhcp_relay.options";
    $rename = 0; $found = 0;
    open(IN,"< $inetd_cf");
    open(OUT,"> $dummy");
    while(<IN>) {
	@items = split(/\s+/);
	if ($items[6] eq "dhcp_relay" || $items[7] eq "dhcp_relay") {
	    $found = 1; 
	    if (substr($items[0],0,1) eq "#") {
		print OUT "$line\n";
		$rename = 1;
	    }
	} else { print OUT $_; }
    }
    if (!$found) { print OUT "$line\n"; $rename = 1; }
    close(IN);
    close(OUT);
    if ($rename) { rename($dummy,$inetd_cf); }
}

sub formValid_add {
    &error("Server name or address required.") if !$addList;
    if ($addList =~ /[^0-9.]/) {	# assume this is not an IP number 
	&error("Please input IP address in dot notation.") if $addList =~ /0x/;
	&error("Invalid hostname: $addList.") if &check_hostname($addList);
	($name, $aliases, $addrtype, $length, @addrs) = gethostbyname($addList);
	&error("Host cannot be resolved.") if !@addrs;
    } else {				# IP num
	&error("Invalid IP address.") if &check_ipaddr($addList);    
    }
}

sub saveList {
    open(SRVLST, ">$srvlist_file") ||
	&error("Cannot open file $srvlist_file for writing.");
    foreach $arg (@server_list) {
	print SRVLST "$arg\n";
    }
    close(SRVLST);
}    

&generic;

sub generic {
    &header_block($title);

    print "<i>$message</i>";

    print $query->startform;

    print "<center><table cellpadding=5 width=450>\n";

    print "<tr><th align=left>Enable DHCP relay agent:</th><th align=left>\n",
	  $query->radio_group(-name=>'rstate',
			  -values=>['Yes','No'],
			  -default=>$def_rstate),
	  "</th></tr>";

    print "<tr><th align=left>",$query->submit(-name=>'add', -value=>'Add New Server'),
	    "</th><td>",$query->textfield(-name=>'add_list', -size=>20),"</td></tr>";

    if ($_[1] == 1) {
	print "<input type=hidden name=addName value=$_[0]>"; 
	@locList = @server_list;
	push(@locList,$_[0]);
    } elsif ($_[1] == 2) {
	print "<input type=hidden name=delName value=$_[0]>"; 
	undef @locList;
	foreach $arg (@server_list) {
	    if ($arg ne $_[0]) { push(@locList,$arg); }
	}
    } else { @locList = @server_list; }

    print "<tr><th align=left valign=top>",$query->submit(-name=>'delete', 
	    -value=>'Delete Existing Server'),
	    "</th><td>",&choice_list(*locList,"chosen",20),"</td></tr>";
    
    print "</table><br>";

    &button_table($query,"doit", "Ok", "help", "Help");

    print $query->endform;
}

sub oldgeneric {
    &header_block($title);

    print "<i>$message</i>";

    print $query->startform;

    print "<center><table cellpadding=5 width=450>\n";

    print "<tr><th align=left>Enable DHCP relay agent:</th><th align=left>\n",
	  $query->radio_group(-name=>'rstate',
			  -values=>['Yes','No'],
			  -default=>$def_rstate),
	  "</th></tr>";

    print "<tr><th align=left>Directory for server configuration files:</th>",
	    "<th align=left>\n",
	  $query->textfield(-name=>'conf_dir',
			    -default=>$def_config_dir,
			    -size=>20, -maxlength=>256),
	  "</th></tr>";

    print "<tr><th align=left>List of DHCP Servers:</th><th align=left>\n",
	  $query->scrolling_list(-name=>'slist', -values=>\@server_list,
			         -size=>6, -multiple=>'true'),
	  "</th></tr>";

    print "<tr><th align=left>Delete Selected Servers from the List:</th><th align=left>\n",
	  $query->radio_group(-name=>'delstate',
			      -values=>['Yes','No'],
			      -default=>'No'),
	  "</th></tr>";

    print "<tr><th align=left>List of new DHCP Servers to Add:</th>",
	  "<th align=top>",
	  $query->textfield(-name=>'add_list',
			    -size=>20, -maxlength=>256),
	  "</th></tr>";

    print "</table></center><br>";

    &button_table($query,"doit", "Ok", "help", "Help");
    print $query->endform;

}


sub
error
{
    &error_block($_[0]);
    &generic;
    exit 0;
}