source: trunk/src/pxeconfigd.py @ 189

# Copyright (C) 2002
#
# This file is part of the pxeconfig utils
#
# 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; either version 2, or (at your option) any
# later version.
#
# 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
#
# SVN info
#  $Id: pxeconfigd.py 189 2010-10-28 14:26:31Z bas $
"""
Author: Bas van der Vlies <basv@sara.nl>
Date  : 12 February 2002
Desc. : This script is used to control how a node is booted with PXE
        enabled network cards. The node boots and fetch a pxe
        config file which tells how the node must boot. This daemon
        enables a client to remove his/here pxe config file. With the
        next boot it will use the default one.

        command line option:
          -V/--version 
            Prints the version number and exits
          
        Note:
          This server can ONLY be started from inetd.
"""
import time
import socket
import sys
import os
import string
import syslog
import getopt

# PXE modules
from pxe_global import *

# DEBUG
#
DEBUG=1

# Some Global Constants
#
BUFSIZE=4096
STDIN=0
STDOUT=1
SHORTOPT_LIST='V'
LONGOPT_LIST=['version']

PXE_CONF_DIR = '/tftpboot/pxelinux.cfg'
VERSION = '3.1.0'

# Give the current time
#
def now():
    return time.ctime(time.time())


def remove_link(ip, arp_cmd):
        """
        This removes the pxe config filename for the host that is connected:
                ip      : ip address of the client host
                arp_cmd : For Dynamic ips, look up the mac address via arp
        """

        ## translate ip address ---> hex address 
        #
        d = string.split(ip, '.')
        haddr = '%02X%02X%02X%02X' %(int(d[0]), int(d[1]), int(d[2]), int(d[3])) 

        file = os.path.join(PXE_CONF_DIR, haddr)

        if not os.path.exists(file): 

                ##
                # No ARP command set, just return
                #
                if not arp_cmd:
                        return

                else:
                        ##
                        #  arp -n 192.168.146.112 
                        # Address          HWtype  HWaddress           Flags Mask Iface
                        # 192.168.146.112  ether   00:23:ae:fd:cf:74   C          vlan133

                        cmd = '%s %s' %(arp_cmd, ip)
                        lines = os.popen(cmd).readlines()
                        for line in lines:
                                if line.startswith(ip):
                                        t = line.split()
                                        mac_addr = t[2] 
                                        haddr = '01-%s' %(mac_addr.replace(':', '-').lower())
                                        file = os.path.join(PXE_CONF_DIR, haddr) 
                                        if not os.path.exists(file): 
                                                return

        if DEBUG:
                print 'file = %s' %file

        if os.path.islink(file): 
                try:
                        os.unlink(file)
                        syslog.openlog("pxeconfigd")
                        syslog.syslog(syslog.LOG_INFO, file)
                        syslog.closelog()
                except OSError:
                        err_msg = "No permission at directory: %s" %PXE_CONF_DIR
                        os.write(STDOUT, err_msg)
                        sys.exit(1)


# This function handles the client connection. It closes
# the connection if there is no data
#
def handleConnection(settings):
        """
        Determines which host connects to the server
        """ 
        
        # Determine client address
        # 
        try:
                client_addr = socket.fromfd(sys.stdin.fileno(), socket.AF_INET, 
                          socket.SOCK_STREAM)
                client_ip = client_addr.getpeername()[0] 
        except socket.error, detail:
                error =  "pxeconfigd can only be started from inetd!!!"
                raise PxeConfig, error 
                
        
        if DEBUG:
                print 'ip = %s' %(client_ip) 

        try:
                cmd = '%s %s' %(settings['daemon_script_hook'], client_ip)
                print cmd
                os.system(cmd)
        except KeyError:
                pass

        try:
                arp_cmd = settings['arp_command']
        except KeyError:
                arp_cmd = None

        remove_link(client_ip, arp_cmd)
        sys.exit(0)

def check_args(argv, settings):
        """
        Must we use another directory for the PXE configuration
        """
        global PXE_CONF_DIR 
        
        try:
                opts, args = getopt.getopt(argv[1:], SHORTOPT_LIST, LONGOPT_LIST)
        except getopt.error, detail:
                print __doc__
                print detail
                sys.exit(1) 
                
        for opt, value in opts:
                if opt in ['-V', '--version']:
                        print VERSION
                        sys.exit(0)

        try:
                PXE_CONF_DIR = settings['pxe_config_dir']
        except KeyError:
                pass 
                
        PXE_CONF_DIR = os.path.realpath(PXE_CONF_DIR) 
        if not os.path.isdir(PXE_CONF_DIR):
                error =  'pxeconfig directory: %s does not exists' %(PXE_CONF_DIR)
                raise PxeConfig, error

def server():
  """Start the daemon
  """
  parser_config, default_settings = ReadConfig()
  check_args(sys.argv, default_settings)
  handleConnection(default_settings)

if __name__ == '__main__':
  server()