#!/usr/bin/perl
# IBM(c) 2007 EPL license http://www.eclipse.org/legal/epl-v10.html
#(C)IBM Corp

#

#-----------------------------------------------------------------------------

=head1   aixremoteshell 

   This sets up the remote shell for root on the AIX node,such that root can
   login with no password. The default is /bin/rsh and
   /bin/rcp but can be overriden by setting the useSSHonAIX attribute in the 
   site table to yes, in which case we will use ssh/scp.
=cut

#-----------------------------------------------------------------------------

#
#  If USESSHONAIX does not exist or is no or 0 then
#     setup .rhosts on the node
#  else (ssh)
#     setup the ssh keys on the node
#  end

# MAIN
use strict;
use IO::Socket;
my $useSocketSSL=eval { require IO::Socket::SSL; };
if ($useSocketSSL) {
        require IO::Socket::SSL;
}

my $rc = 0;

# Override from site table
my $usesshonaix = $ENV{'USESSHONAIX'};
my $master      = $ENV{'MASTER'};
my $node        = $ENV{'NODE'};
my $nodetype     = $ENV{'NTYPE'};
my $enablesshbetweennodes  = $ENV{'ENABLESSHBETWEENNODES'};
my $msg;
my $home;
my $cmd;
my $username = "root";
my @root = split ':', (`/bin/grep ^$username /etc/passwd 2>&1`);
$home = $root[5];
#  root home directory must be root system 
$rc = &runcmd("chown root $home");
if ($rc != 0)
{
   my $msg = "It fails to chown root $home";
   `logger -t xcat -p local4.err $msg`;
   exit 1;
}
$rc = &runcmd("chgrp system $home");
if ($rc != 0)
{
   my $msg = "It fails to chgrp system $home";
   `logger -t xcat  -p local4.err $msg`;
   exit 1;
}

$usesshonaix =~ tr/a-z/A-Z/;    # convert to upper
if ((!defined($usesshonaix)) || ($usesshonaix eq "0") || ($usesshonaix eq "NO"))
{   # setting up rsh
    # setup .rhosts if not already setup
    $cmd = "/bin/grep \"^$master root\" /.rhosts";
    `$cmd 2>&1`;
    my $rc = $? >> 8;
    if ($rc)
    {    # if not found, then add entry in .rhosts
        &runcmd("/bin/echo $master root >> /.rhosts");
        chmod 0600, "/.rhosts";
    }

}
else
{    
	# setting up ssh
	if (&setupSSH != 0) {
		my $msg = "Failed to setup ssh on $node.\n";
		`logger -t xcat  -p local4.err  $msg`;
#	print $msg;
		exit 0;
	}
}

exit 0;

#
# Subroutines
#

sub setupSSH
{
    my $sshdconfig = "/etc/ssh/sshd_config";
    my $sshconfig  = "/etc/ssh/ssh_config";

    if (-e $sshdconfig)
    {   # ssh installed
        my $tmp="$sshdconfig.ORIG";
        if (!(-e "$sshdconfig.ORIG"))
        {
            &runcmd("cp $sshdconfig $sshdconfig.ORIG");
        }
        &runcmd("echo \"KeyRegenerationInterval 0\" >>$sshdconfig");
        &runcmd("echo \"X11Forwarding yes\" >>$sshdconfig");
        &runcmd("echo \"MaxStartups 1024\" >>$sshdconfig");
        &runcmd("echo \"ListenAddress ::\" >>$sshdconfig");
        &runcmd("echo \"ListenAddress 0.0.0.0\" >>$sshdconfig");
        #&runcmd("echo \"PasswordAuthentication no\" >>$sshdconfig");
        if (!(-e "$sshconfig.ORIG"))
        {
            &runcmd("cp $sshconfig $sshconfig.ORIG");
        }
        &runcmd("echo \"StrictHostKeyChecking no\" >>$sshconfig");
    }
    else
    {    # ssh not installed
        my $msg = "Failed to setup ssh on $node, ssh not installed. \n";
        `logger -t xcat -p local4.err  $msg`;
        exit 0;
    }

    if (-e "/xcatpost/_ssh")
    {    # ssh public key available
        $rc = &runcmd("mkdir -p /.ssh");
        if ($rc == 0)
        {
            $rc = &runcmd("cp -fp /xcatpost/_ssh/* /.ssh");
            if ($rc == 0)
            {
                $rc = &runcmd("chmod 0700 /.ssh");
                $rc = &runcmd("chmod 0600 /.ssh/*");
            }
        }
    }
    else
    {    # ssh keys not available
        my $msg = "Failed to setup ssh on $node, ssh keys not available. \n";
        `logger -t xcat  -p local4.err $msg`;
        exit 0;
    }

    #  get the name of my service node/NIM master from /etc/xcatinfo 
	#  ! use value of MASTER env variable instead
	$::servnode = $master;

	my $response=&getresponse("ssh_dsa_hostkey");
	if (defined ($response) ) {
		my $fd;
		my $filename = "/etc/ssh/ssh_host_dsa_key";
		&runcmd("mkdir -p /etc/ssh");		
		open($fd, '>',$filename);
		print $fd $response;
		close($fd);
		
		# set the permissions
		my $cmd = "chmod 600 $filename > /dev/null 2>&1";
		&runcmd($cmd);
	}
	else {
        $msg = "aixremoteshell: Could not get ssh_host_dsa_key file.\n";
        `logger -t xcat  -p local4.err  $msg`;
    }

	my $response=&getresponse("ssh_rsa_hostkey");
	if (defined ($response) ) {
		my $fd;
		my $filename = "/etc/ssh/ssh_host_rsa_key";
		&runcmd("mkdir -p /etc/ssh");
		open($fd, '>',$filename);
		print $fd $response;
		close($fd);

		# set the permissions
		my $cmd = "chmod 600 $filename > /dev/null 2>&1";
		&runcmd($cmd);
	}
	else {
        $msg = "aixremoteshell: Could not get ssh_host_rsa_key file.\n";
        `logger -t xcat  -p local4.err $msg`;
    }
        if ( $nodetype eq "service") {
		&runcmd("mkdir -p /etc/xcat/hostkeys; cp /etc/ssh/ssh* /etc/xcat/hostkeys/. > /dev/null 2>&1");
	}
        # Decide whether to enable ssh between the nodes
        if ($enablesshbetweennodes eq "YES") {
	  my $response=&getresponse("ssh_root_key");
	  if (defined ($response) ) {
		my $fd;
		my $filename = "/.ssh/id_rsa";
		&runcmd("mkdir -p /.ssh");
		open($fd, '>',$filename);
		print $fd $response;
		close($fd);

		# set the permissions
#TODO - what perms are needed???
		my $cmd = "chmod 600 $filename > /dev/null 2>&1";
		&runcmd($cmd);

		if ( -f "/.ssh/id_rsa" ) {
			&runcmd("ssh-keygen -y -f /.ssh/id_rsa > /.ssh/id_rsa.pub");
		}
	  }
	  else {
            $msg = "aixremoteshell: Could not get id_rsa file.\n";
            `logger -t xcat  -p local4.err  $msg`;
          }
        }

	return 0;
}

#####################################################
#
#  getresponse
#       Request info from xcatd on the management node
#
#	- uses SSL socket on port 3001 to connect to MN xcatd
#		to make the request for info
#
#####################################################
sub getresponse
{
	my ($req) = @_;

	my $port = "3001";

	# open listener connection to wait for check from management node
	my $lpid = &openlistener();

	# open a socket to request credentials
	my $sock = IO::Socket::SSL->new(
		PeerAddr => $::servnode,
		PeerPort  => $port,
		Proto    => 'tcp',
	);

	unless ($sock) {
		my $msg = "aixremoteshell: Cannot connect to host \'$::servnode\'\n";
		`logger -t xcat  -p local4.err  $msg`;
		#print $msg;
		kill 2, $lpid;
		return undef;
	}

	# request must be in XML format
	print $sock "<xcatrequest>\n";
	print $sock "   <command>getcredentials</command>\n";
	print $sock "   <arg>$req</arg>\n";
	print $sock "   <callback_port>300</callback_port>\n";
	print $sock "</xcatrequest>\n";

#TODO - do we have to try again after waiting for a bit????
	my $response='';
	my $line;
	while (defined ($line = <$sock>)) {
		# skip xml tags
		next if ($line =~ /^\s*</);

		# once we get to serverdone we have the whole response
		if ($line =~ m/<\/serverdone>/) {
			last:
		}
		$response .= $line;
	}

	close ($sock);

	kill 2, $lpid;
	if ($response) {
		return $response;
	}
	return undef;
}

#####################################################
#
#  openlistener
#   - fork a child process to respond to a check from the MN
#
#####################################################
sub openlistener
{
	my $node = $ENV{'NODE'};

	# fork a child process to open a socket to listen for communication 
	#	from the server
	my $pid = fork;
	unless (defined $pid) {
		# fork failed
		$msg = "aixremoteshell: Could not fork process.\n";
		`logger -t xcat  -p local4.err  $msg`;
		print $msg;
		return undef;
	}

	if ($pid != 0) {
        # This is the parent process, just return 
        return $pid;
    }

	my $listener = IO::Socket::INET->new(
		LocalPort  => '300',
		Proto    => 'tcp',
		Listen  => '64',
		Reuse => 1
	);

	unless ($listener) {
       	my $msg = "aixremoteshell: Cannot open socket on \'$node\'\n";
   		`logger -t xcat  -p local4.err $msg`;
		print $msg;
       	exit 1;
   	}

	#	xcatd sends a quick req to see if we are really asking
	#  	for info - this listener checks for the req and says ok
	my $client;
	while ($client = $listener->accept()) {
		# $client is the new connection   
		my $text=<$client>;

    	#  see if we got "CREDOKBYYOU?"
		if ($text =~ /CREDOKBYYOU?/) {
			print $client "CREDOKBYME";
			close($client);
			close($listener); 
			exit 0;
		}
		close($client);
	}
	close($client);
	close($listener);
	exit 0;
}

#
# run the command
#
sub runcmd
{
    my ($cmd) = @_;
    my $rc = 0;
    $cmd .= ' 2>&1';
	$::outref = `$cmd`;
    if ($?)
    {
        $rc = $? >> 8;
        if ($rc > 0)
        {
            my $msg = "$cmd returned rc=$rc @$::outref\n";
            `logger -t xcat  -p local4.info $msg`;
#			print $msg;
        }
    }
    return 0;
}