Merge branch 'feature/dhcp' of https://github.com/c0d3z3r0/impacket i…

…nto c0d3z3r0-feature/dhcp

impacket/ImpactDecoder.py

@@ -22,7 +22,7 @@
 import IP6_Extension_Headers
 from cdp import CDP
 from Dot11Crypto import RC4
-from impacket import wps, eap
+from impacket import wps, eap, dhcp
 from impacket.dot11 import Dot11WEPData
 from impacket import LOG
 
@@ -282,8 +282,12 @@ def decode(self, aBuffer):
         u = ImpactPacket.UDP(aBuffer)
         self.set_decoded_protocol( u )
         off = u.get_header_size()
-        self.data_decoder = DataDecoder()
-        packet = self.data_decoder.decode(aBuffer[off:])
+        if u.get_uh_dport() in (67, 68) and u.get_uh_sport() in (67, 68):
+            self.bootp_decoder = BootpDecoder()
+            packet = self.bootp_decoder.decode(aBuffer[off:])
+        else:
+            self.data_decoder = DataDecoder()
+            packet = self.data_decoder.decode(aBuffer[off:])
         u.contains(packet)
         return u
 
@@ -975,4 +979,26 @@ class EAPOLDecoder(BaseDecoder):
     }
     klass = eap.EAPOL
     child_key = lambda s, p: p.get_packet_type()
-
+
+class BootpDecoder(Decoder):
+    def __init__(self):
+        pass
+
+    def decode(self, aBuffer):
+        d = dhcp.BootpPacket(aBuffer)
+        self.set_decoded_protocol( d )
+        off = len(d.getData())
+        if dhcp.DhcpPacket(aBuffer[off:])['cookie'] == dhcp.DhcpPacket.MAGIC_NUMBER:
+            self.data_decoder = DHCPDecoder()
+            packet = self.data_decoder.decode(aBuffer[off:])
+            d.contains(packet)
+        return d
+
+class DHCPDecoder(Decoder):
+    def __init__(self):
+        pass
+
+    def decode(self, aBuffer):
+        d = dhcp.DhcpPacket(aBuffer)
+        self.set_decoded_protocol( d )
+        return d

impacket/dhcp.py

@@ -6,9 +6,9 @@
 #
 
 from impacket import structure
+from impacket.ImpactPacket import ProtocolPacket
 
-
-class BootpPacket(structure.Structure):
+class BootpPacket(ProtocolPacket, structure.Structure):
     commonHdr = (
             ('op','b'),
             ('htype','b=1'),    # 1 = Ether
@@ -26,13 +26,14 @@ class BootpPacket(structure.Structure):
             ('sname','64s=""'),
             ('file','128s=""'))
 
-    #def __init__(self, data = None, alignment = 0):
-    #    structure.Structure.__init__(self, data, alignment)
-        
-class DhcpPacket(BootpPacket):
+    def __init__(self, data = None, alignment = 0):
+        structure.Structure.__init__(self, data, alignment)
+
+class DhcpPacket(ProtocolPacket, structure.Structure):
     # DHCP: http://www.faqs.org/rfcs/rfc2131.html
     # DHCP Options: http://www.faqs.org/rfcs/rfc1533.html
     # good list of options: http://www.networksorcery.com/enp/protocol/bootp/options.htm
+    MAGIC_NUMBER = 0x63825363
     BOOTREQUEST = 1
     BOOTREPLY   = 2
 
@@ -140,10 +141,9 @@ class DhcpPacket(BootpPacket):
             ('cookie','!L'),
             ('_options',':=self.packOptions(options)'),
             ('options','_','self.unpackOptions(_options)'))
-
 
-    #def __init__(self, data = None, alignment = 0):
-    #    BootpPacket.__init__(self, data, alignment)
+    def __init__(self, data = None, alignment = 0):
+        structure.Structure.__init__(self, data, alignment)
 
     def packOptions(self, options):
         # options is an array of tuples: ('name',value)