+++ /dev/null
-# Anemon Dhcp
-# Copyright (C) 2005 Mathieu Ignacio -- mignacio@april.org
-#
-# 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 of the License, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
-
-import operator
-from struct import unpack
-from struct import pack
-from dhcp_constants import *
-
-# DhcpPacket : base class to encode/decode dhcp packets.
-
-
-class DhcpBasicPacket:
- def __init__(self):
- self.packet_data = [0]*240
- self.options_data = {}
- self.packet_data[236:240] = MagicCookie
-
- def IsDhcpPacket(self):
- if self.packet_data[236:240] != MagicCookie : return False
- return True
-
- # Check if variable is a list with int between 0 and 255
- def CheckType(self,variable):
- if type(variable) == list :
- for each in variable :
- if (type(each) != int) or (each < 0) or (each > 255) :
- return False
- return True
- else : return False
-
-
- def DeleteOption(self,name):
- # if name is a standard dhcp field
- # Set field to 0
- if DhcpFields.has_key(name) :
- begin = DhcpFields[name][0]
- end = DhcpFields[name][0]+DhcpFields[name][1]
- self.packet_data[begin:end] = [0]*DhcpFields[name][1]
- return True
-
- # if name is a dhcp option
- # delete option from self.option_data
- elif self.options_data.has_key(name) :
- # forget how to remove a key... try delete
- self.options_data.__delitem__(name)
- return True
-
- return False
-
- def GetOption(self,name):
- if DhcpFields.has_key(name) :
- option_info = DhcpFields[name]
- return self.packet_data[option_info[0]:option_info[0]+option_info[1]]
-
- elif self.options_data.has_key(name) :
- return self.options_data[name]
-
- return []
-
-
- def SetOption(self,name,value):
-
- # Basic vlue checking :
- # has value list a correct length
-
- # if name is a standard dhcp field
- if DhcpFields.has_key(name) :
- if len(value) != DhcpFields[name][1] :
- print "Error, bad option length (a): ", name
- return False
- begin = DhcpFields[name][0]
- end = DhcpFields[name][0]+DhcpFields[name][1]
- self.packet_data[begin:end] = value
- return True
-
- # if name is a dhcp option
- elif DhcpOptions.has_key(name) :
-
- # fields_specs : {'option_code',fixed_length,minimum_length,multiple}
- # if fixed_length == 0 : minimum_length and multiple apply
- # else : forget minimum_length and multiple
- # multiple : length MUST be a multiple of 'multiple'
- fields_specs = { "ipv4":[4,0,1], "ipv4+":[0,4,4],
- "string":[0,0,1], "bool":[1,0,1],
- "char":[1,0,1], "16-bits":[2,0,1],
- "32-bits":[4,0,1], "identifier":[0,2,1]}
-
- specs = fields_specs[DhcpOptionsTypes[DhcpOptions[name]]]
- length = len(value)
- if (specs[0]!=0 and specs==length) or (specs[1]<=length and length%specs[2]==0):
- self.options_data[name] = value
- return True
- else :
- return False
-
- print "Error, unknown option : ", name, value
- return False
-
-
-
- def IsOption(self,name):
- if self.options_data.has_key(name) : return True
- elif DhcpFields.has_key(name) : return True
- else : return False
-
-
- # Encode Packet and return it
- def EncodePacket(self):
- options = []
-
-
- for each in self.options_data.keys() :
- options.append(DhcpOptions[each])
- options.append(len(self.options_data[each]))
- options += self.options_data[each]
-
- packet = self.packet_data[:240] + options
- packet.append(255) # add end option
- pack_fmt = str(len(packet))+"c"
-
- packet = map(chr,packet)
-
- return pack(pack_fmt,*packet)
-
-
- # Insert packet in the object
- def DecodePacket(self,data,debug=False):
- self.packet_data = []
- self.options_data = {}
-
- if (not data) : return False
- # we transform all data to int list
- unpack_fmt = str(len(data)) + "c"
- for i in unpack(unpack_fmt,data):
- self.packet_data.append(ord(i))
- if ( debug ) : print "Packet length : ",len(self.packet_data)
-
-
- # Some servers or clients don't place magic cookie immediately
- # after headers and begin options fields only after magic.
- # These 4 lines search magic cookie and begin iterator after.
- iterator = 236
- end_iterator = len(self.packet_data)
- while ( self.packet_data[iterator:iterator+4] != MagicCookie and iterator < end_iterator) :
- iterator += 1
- iterator += 4
-
- # parse extended options
- if ( debug ) : print "Debug : ", self.packet_data[iterator:-1]
-
-
- while iterator < end_iterator :
- if ( debug ) :
- print "Debug Option : ", iterator , self.packet_data[iterator]," : ",DhcpOptionsList[self.packet_data[iterator]]
- if self.packet_data[iterator] == 0 : # pad option
- opt_first = iterator+1
- iterator += 1
-
- elif self.packet_data[iterator] == 255 :
- self.packet_data = self.packet_data[:240] # base packet length without magic cookie
- return
-
- elif DhcpOptionsTypes.has_key(self.packet_data[iterator]) and self.packet_data[iterator]!= 255:
- opt_len = self.packet_data[iterator+1]
- opt_first = iterator+1
- self.options_data[DhcpOptionsList[self.packet_data[iterator]]] = self.packet_data[opt_first+1:opt_len+opt_first+1]
- iterator += self.packet_data[opt_first] + 2
- else :
- opt_first = iterator+1
- iterator += self.packet_data[opt_first] + 2
-
- # cut packet_data to remove options
-
- self.packet_data = self.packet_data[:240] # base packet length with magic cookie
projects / invirt/packages/invirt-dhcp.git / blobdiff