scapy python 2/3

1 files changed, 1346 insertions, 0 deletions

diff --git a/scripts/external_libs/scapy-2.3.1/python2/scapy/packet.py b/scripts/external_libs/scapy-2.3.1/python2/scapy/packet.py
new file mode 100644
index 00000000..711d7032
--- /dev/null
+++ b/scripts/external_libs/scapy-2.3.1/python2/scapy/packet.py
@@ -0,0 +1,1346 @@
+## This file is part of Scapy
+## See http://www.secdev.org/projects/scapy for more informations
+## Copyright (C) Philippe Biondi <phil@secdev.org>
+## This program is published under a GPLv2 license
+
+"""
+Packet class. Binding mechanism. fuzz() method.
+"""
+
+import time,itertools,os
+import copy
+from fields import StrField,ConditionalField,Emph,PacketListField
+from config import conf
+from base_classes import BasePacket,Gen,SetGen,Packet_metaclass,NewDefaultValues
+from volatile import VolatileValue
+from utils import import_hexcap,tex_escape,colgen,get_temp_file
+from error import Scapy_Exception,log_runtime
+import subprocess
+import pprint 
+
+class CGlobal:
+       ONCE =False
+try:
+    import pyx
+except ImportError:
+    pass
+
+
+class RawVal:
+    def __init__(self, val=""):
+        self.val = val
+    def __str__(self):
+        return str(self.val)
+    def __repr__(self):
+        return "<RawVal [%r]>" % self.val
+
+class CPacketRes:
+    pass;
+
+
+class Packet(BasePacket):
+    __metaclass__ = Packet_metaclass
+    name=None
+
+    fields_desc = []
+
+    aliastypes = []
+    overload_fields = {}
+
+    underlayer = None
+
+    sent_time = None
+    payload_guess = []
+    initialized = 0
+    show_indent=1
+    explicit = 0
+    raw_packet_cache = None
+
+    @classmethod
+    def from_hexcap(cls):
+        return cls(import_hexcap())
+
+    @classmethod
+    def upper_bonds(self):
+        for fval,upper in self.payload_guess:
+            print "%-20s  %s" % (upper.__name__, ", ".join("%-12s" % ("%s=%r"%i) for i in fval.iteritems()))
+
+    @classmethod
+    def lower_bonds(self):
+        for lower,fval in self.overload_fields.iteritems():
+            print "%-20s  %s" % (lower.__name__, ", ".join("%-12s" % ("%s=%r"%i) for i in fval.iteritems()))
+
+    def __init__(self, _pkt="", post_transform=None, _internal=0, _underlayer=None, **fields):
+        self.time  = time.time()
+        self.sent_time = 0
+        if self.name is None:
+            self.name = self.__class__.__name__
+        self.aliastypes = [ self.__class__ ] + self.aliastypes
+        self.default_fields = {}
+        self.offset=0;  # offset of the object
+        self.offset_fields = {} # ofsset of each field
+        self.overloaded_fields = {}
+        self.fields={}
+        self.fieldtype={}
+        self.packetfields=[]
+        self.__dict__["payload"] = NoPayload()
+        self.init_fields()
+        self.underlayer = _underlayer
+        self.initialized = 1
+        self.original = _pkt
+        if _pkt:
+            self.dissect(_pkt)
+            if not _internal:
+                self.dissection_done(self)
+        for f in fields.keys():
+            self.fields[f] = self.get_field(f).any2i(self,fields[f])
+        if type(post_transform) is list:
+            self.post_transforms = post_transform
+        elif post_transform is None:
+            self.post_transforms = []
+        else:
+            self.post_transforms = [post_transform]
+
+
+    def init_fields(self):
+        self.do_init_fields(self.fields_desc)
+
+    def do_init_fields(self, flist):
+        for f in flist:
+            self.default_fields[f.name] = copy.deepcopy(f.default)
+            self.fieldtype[f.name] = f
+            if f.holds_packets:
+                self.packetfields.append(f)
+            
+    def dissection_done(self,pkt):
+        """DEV: will be called after a dissection is completed"""
+        self.post_dissection(pkt)
+        self.payload.dissection_done(pkt)
+        
+    def post_dissection(self, pkt):
+        """DEV: is called after the dissection of the whole packet"""
+        pass
+
+    def get_field(self, fld):
+        """DEV: returns the field instance from the name of the field"""
+        return self.fieldtype[fld]
+        
+    def add_payload(self, payload):
+        if payload is None:
+            return
+        elif not isinstance(self.payload, NoPayload):
+            self.payload.add_payload(payload)
+        else:
+            if isinstance(payload, Packet):
+                self.__dict__["payload"] = payload
+                payload.add_underlayer(self)
+                for t in self.aliastypes:
+                    if payload.overload_fields.has_key(t):
+                        self.overloaded_fields = payload.overload_fields[t]
+                        break
+            elif type(payload) is str:
+                self.__dict__["payload"] = conf.raw_layer(load=payload)
+            else:
+                raise TypeError("payload must be either 'Packet' or 'str', not [%s]" % repr(payload))
+    def remove_payload(self):
+        self.payload.remove_underlayer(self)
+        self.__dict__["payload"] = NoPayload()
+        self.overloaded_fields = {}
+    def add_underlayer(self, underlayer):
+        self.underlayer = underlayer
+    def remove_underlayer(self,other):
+        self.underlayer = None
+    def copy(self):
+        """Returns a deep copy of the instance."""
+        clone = self.__class__()
+        clone.fields = self.fields.copy()
+        for k in clone.fields:
+            clone.fields[k] = self.get_field(k).do_copy(clone.fields[k])
+        clone.default_fields = self.default_fields.copy()
+        clone.overloaded_fields = self.overloaded_fields.copy()
+        clone.overload_fields = self.overload_fields.copy()
+        clone.offset=self.offset
+        clone.underlayer = self.underlayer
+        clone.explicit = self.explicit
+        clone.raw_packet_cache = self.raw_packet_cache
+        clone.post_transforms = self.post_transforms[:]
+        clone.__dict__["payload"] = self.payload.copy()
+        clone.payload.add_underlayer(clone)
+        return clone
+
+    def dump_offsets (self):
+        print "obj-id ",id(self),
+        print self.name ,self.offset 
+        if self.payload:
+            self.payload.dump_offsets()
+
+
+
+    def getfieldval(self, attr):
+        if attr in self.fields:
+            return self.fields[attr]
+        if attr in self.overloaded_fields:
+            return self.overloaded_fields[attr]
+        if attr in self.default_fields:
+            return self.default_fields[attr]
+        return self.payload.getfieldval(attr)
+    
+    def getfield_and_val(self, attr):
+        if attr in self.fields:
+            return self.get_field(attr),self.fields[attr]
+        if attr in self.overloaded_fields:
+            return self.get_field(attr),self.overloaded_fields[attr]
+        if attr in self.default_fields:
+            return self.get_field(attr),self.default_fields[attr]
+        return self.payload.getfield_and_val(attr)
+    
+    def __getattr__(self, attr):
+        if self.initialized:
+            fld,v = self.getfield_and_val(attr)
+            if fld is not None:
+                return fld.i2h(self, v)
+            return v
+        raise AttributeError(attr)
+
+    def setfieldval(self, attr, val):
+        if self.default_fields.has_key(attr):
+            fld = self.get_field(attr)
+            if fld is None:
+                any2i = lambda x,y: y
+            else:
+                any2i = fld.any2i
+            self.fields[attr] = any2i(self, val)
+            self.explicit = 0
+            self.raw_packet_cache = None
+        elif attr == "payload":
+            self.remove_payload()
+            self.add_payload(val)
+        else:
+            self.payload.setfieldval(attr,val)
+
+    def __setattr__(self, attr, val):
+        if self.initialized:
+            try:
+                self.setfieldval(attr,val)
+            except AttributeError:
+                pass
+            else:
+                return
+        self.__dict__[attr] = val
+
+    def delfieldval(self, attr):
+        if self.fields.has_key(attr):
+            del(self.fields[attr])
+            self.explicit = 0 # in case a default value must be explicited
+            self.raw_packet_cache = None
+        elif self.default_fields.has_key(attr):
+            pass
+        elif attr == "payload":
+            self.remove_payload()
+        else:
+            self.payload.delfieldval(attr)
+
+    def __delattr__(self, attr):
+        if self.initialized:
+            try:
+                self.delfieldval(attr)
+            except AttributeError:
+                pass
+            else:
+                return
+        if self.__dict__.has_key(attr):
+            del(self.__dict__[attr])
+        else:
+            raise AttributeError(attr)
+            
+    def __repr__(self):
+        s = ""
+        ct = conf.color_theme
+        for f in self.fields_desc:
+            if isinstance(f, ConditionalField) and not f._evalcond(self):
+                continue
+            if f.name in self.fields:
+                val = f.i2repr(self, self.fields[f.name])
+            elif f.name in self.overloaded_fields:
+                val =  f.i2repr(self, self.overloaded_fields[f.name])
+            else:
+                continue
+            if isinstance(f, Emph) or f in conf.emph:
+                ncol = ct.emph_field_name
+                vcol = ct.emph_field_value
+            else:
+                ncol = ct.field_name
+                vcol = ct.field_value
+
+                
+            s += " %s%s%s" % (ncol(f.name),
+                              ct.punct("="),
+                              vcol(val))
+        return "%s%s %s %s%s%s"% (ct.punct("<"),
+                                  ct.layer_name(self.__class__.__name__),
+                                  s,
+                                  ct.punct("|"),
+                                  repr(self.payload),
+                                  ct.punct(">"))
+    def __str__(self):
+        return self.build()
+    def __div__(self, other):
+        if isinstance(other, Packet):
+            cloneA = self.copy()
+            cloneB = other.copy()
+            cloneA.add_payload(cloneB)
+            return cloneA
+        elif type(other) is str:
+            return self/conf.raw_layer(load=other)
+        else:
+            return other.__rdiv__(self)
+    __truediv__ = __div__
+    def __rdiv__(self, other):
+        if type(other) is str:
+            return conf.raw_layer(load=other)/self
+        else:
+            raise TypeError
+    __rtruediv__ = __rdiv__
+    def __mul__(self, other):
+        if type(other) is int:
+            return  [self]*other
+        else:
+            raise TypeError
+    def __rmul__(self,other):
+        return self.__mul__(other)
+    
+    def __nonzero__(self):
+        return True
+    def __len__(self):
+        return len(self.__str__())
+
+    def dump_fields_offsets (self):
+        for f in self.fields_desc:
+            print "field %-40s %02d %02d" % (f.name, f.offset,f.get_size_bytes ());
+
+
+    def self_build(self, field_pos_list=None):
+        if self.raw_packet_cache is not None:
+            return self.raw_packet_cache
+        p=""
+        for f in self.fields_desc:
+            if type(p) is tuple :
+                f.offset=len(p[0])
+            else:
+                assert(type(p)==str)
+                f.offset=len(p)
+
+            val = self.getfieldval(f.name)
+            if isinstance(val, RawVal):
+                sval = str(val)
+                p += sval
+                if field_pos_list is not None:
+                    field_pos_list.append( (f.name, sval.encode("string_escape"), len(p), len(sval) ) )
+                f.offset= val
+            else:
+                p = f.addfield(self, p, val)
+                
+        return p
+
+    def do_build_payload(self):
+        return self.payload.do_build(None)
+
+    def do_update_payload_offset(self,pkt):
+        #print "obj-id ",id(self)
+        #print "current offset ",self.name," ",self.offset
+        #print "current header size  ",len(pkt)
+        self.payload.offset = self.offset + len(pkt)
+
+    def dump_layers_offset (self):
+        p=self;
+        while True:
+            print p.name, "offset :",p.offset
+            p=p.payload
+            if p ==None or isinstance(p,NoPayload):
+                break;
+
+
+
+
+    def do_build(self,result):
+        if not self.explicit:
+            self = self.__iter__().next()
+        pkt = self.self_build()
+        for t in self.post_transforms:
+            pkt = t(pkt)
+        self.do_update_payload_offset(pkt)
+        pay = self.do_build_payload()
+        p = self.post_build(pkt,pay)
+        if result != None:
+            result.pkt = self;
+        return p
+    
+    def build_padding(self):
+        return self.payload.build_padding()
+
+    def update_build_info (self,other):
+
+        p=self;
+        o=other;
+        while True:
+            assert(p.aliastypes==o.aliastypes)
+            assert(type(p) == type(o) )
+
+            #copy
+            p.offset=o.offset
+
+            #next 
+            p=p.payload
+            o=o.payload
+            if p ==None or isinstance(p,NoPayload):
+                break;
+
+
+
+    def build(self):
+        result = CPacketRes;
+        p = self.do_build(result)
+        p += self.build_padding()
+        p = self.build_done(p)
+
+        self.update_build_info (result.pkt)
+        return p
+    
+    def post_build(self, pkt, pay):
+        """DEV: called right after the current layer is build."""
+        return pkt+pay
+
+    def build_done(self, p):
+        return self.payload.build_done(p)
+
+
+    def do_build_ps(self):
+        p=""
+        pl = []
+        q=""
+        for f in self.fields_desc:
+            if isinstance(f, ConditionalField) and not f._evalcond(self):
+                continue
+            p = f.addfield(self, p, self.getfieldval(f.name) )
+            if type(p) is str:
+                r = p[len(q):]
+                q = p
+            else:
+                r = ""
+            pl.append( (f, f.i2repr(self,self.getfieldval(f.name)), r) )
+            
+        pkt,lst = self.payload.build_ps(internal=1)
+        p += pkt
+        lst.append( (self, pl) )
+        
+        return p,lst
+    
+    def build_ps(self,internal=0):
+        p,lst = self.do_build_ps()
+#        if not internal:
+#            pkt = self
+#            while pkt.haslayer(conf.padding_layer):
+#                pkt = pkt.getlayer(conf.padding_layer)
+#                lst.append( (pkt, [ ("loakjkjd", pkt.load, pkt.load) ] ) )
+#                p += pkt.load
+#                pkt = pkt.payload
+        return p,lst
+
+
+    def psdump(self, filename=None, **kargs):
+        """psdump(filename=None, layer_shift=0, rebuild=1)
+Creates an EPS file describing a packet. If filename is not provided a temporary file is created and gs is called."""
+        canvas = self.canvas_dump(**kargs)
+        if filename is None:
+            fname = get_temp_file(autoext=".eps")
+            canvas.writeEPSfile(fname)
+            subprocess.Popen([conf.prog.psreader, fname+".eps"])
+        else:
+            canvas.writeEPSfile(filename)
+
+    def pdfdump(self, filename=None, **kargs):
+        """pdfdump(filename=None, layer_shift=0, rebuild=1)
+        Creates a PDF file describing a packet. If filename is not provided a temporary file is created and xpdf is called."""
+        canvas = self.canvas_dump(**kargs)
+        if filename is None:
+            fname = get_temp_file(autoext=".pdf")
+            canvas.writePDFfile(fname)
+            subprocess.Popen([conf.prog.pdfreader, fname+".pdf"])
+        else:
+            canvas.writePDFfile(filename)
+
+        
+    def canvas_dump(self, layer_shift=0, rebuild=1):
+        canvas = pyx.canvas.canvas()
+        if rebuild:
+            p,t = self.__class__(str(self)).build_ps()
+        else:
+            p,t = self.build_ps()
+        YTXT=len(t)
+        for n,l in t:
+            YTXT += len(l)
+        YTXT = float(YTXT)
+        YDUMP=YTXT
+
+        XSTART = 1
+        XDSTART = 10
+        y = 0.0
+        yd = 0.0
+        xd = 0 
+        XMUL= 0.55
+        YMUL = 0.4
+    
+        backcolor=colgen(0.6, 0.8, 1.0, trans=pyx.color.rgb)
+        forecolor=colgen(0.2, 0.5, 0.8, trans=pyx.color.rgb)
+#        backcolor=makecol(0.376, 0.729, 0.525, 1.0)
+        
+        
+        def hexstr(x):
+            s = []
+            for c in x:
+                s.append("%02x" % ord(c))
+            return " ".join(s)
+
+                
+        def make_dump_txt(x,y,txt):
+            return pyx.text.text(XDSTART+x*XMUL, (YDUMP-y)*YMUL, r"\tt{%s}"%hexstr(txt), [pyx.text.size.Large])
+
+        def make_box(o):
+            return pyx.box.rect(o.left(), o.bottom(), o.width(), o.height(), relcenter=(0.5,0.5))
+
+        def make_frame(lst):
+            if len(lst) == 1:
+                b = lst[0].bbox()
+                b.enlarge(pyx.unit.u_pt)
+                return b.path()
+            else:
+                fb = lst[0].bbox()
+                fb.enlarge(pyx.unit.u_pt)
+                lb = lst[-1].bbox()
+                lb.enlarge(pyx.unit.u_pt)
+                if len(lst) == 2 and fb.left() > lb.right():
+                    return pyx.path.path(pyx.path.moveto(fb.right(), fb.top()),
+                                         pyx.path.lineto(fb.left(), fb.top()),
+                                         pyx.path.lineto(fb.left(), fb.bottom()),
+                                         pyx.path.lineto(fb.right(), fb.bottom()),
+                                         pyx.path.moveto(lb.left(), lb.top()),
+                                         pyx.path.lineto(lb.right(), lb.top()),
+                                         pyx.path.lineto(lb.right(), lb.bottom()),
+                                         pyx.path.lineto(lb.left(), lb.bottom()))
+                else:
+                    # XXX
+                    gb = lst[1].bbox()
+                    if gb != lb:
+                        gb.enlarge(pyx.unit.u_pt)
+                    kb = lst[-2].bbox()
+                    if kb != gb and kb != lb:
+                        kb.enlarge(pyx.unit.u_pt)
+                    return pyx.path.path(pyx.path.moveto(fb.left(), fb.top()),
+                                         pyx.path.lineto(fb.right(), fb.top()),
+                                         pyx.path.lineto(fb.right(), kb.bottom()),
+                                         pyx.path.lineto(lb.right(), kb.bottom()),
+                                         pyx.path.lineto(lb.right(), lb.bottom()),
+                                         pyx.path.lineto(lb.left(), lb.bottom()),
+                                         pyx.path.lineto(lb.left(), gb.top()),
+                                         pyx.path.lineto(fb.left(), gb.top()),
+                                         pyx.path.closepath(),)
+                                         
+
+        def make_dump(s, shift=0, y=0, col=None, bkcol=None, larg=16):
+            c = pyx.canvas.canvas()
+            tlist = []
+            while s:
+                dmp,s = s[:larg-shift],s[larg-shift:]
+                txt = make_dump_txt(shift, y, dmp)
+                tlist.append(txt)
+                shift += len(dmp)
+                if shift >= 16:
+                    shift = 0
+                    y += 1
+            if col is None:
+                col = pyx.color.rgb.red
+            if bkcol is None:
+                col = pyx.color.rgb.white
+            c.stroke(make_frame(tlist),[col,pyx.deco.filled([bkcol]),pyx.style.linewidth.Thick])
+            for txt in tlist:
+                c.insert(txt)
+            return c, tlist[-1].bbox(), shift, y
+                            
+
+        last_shift,last_y=0,0.0
+        while t:
+            bkcol = backcolor.next()
+            proto,fields = t.pop()
+            y += 0.5
+            pt = pyx.text.text(XSTART, (YTXT-y)*YMUL, r"\font\cmssfont=cmss10\cmssfont{%s}" % proto.name, [ pyx.text.size.Large])
+            y += 1
+            ptbb=pt.bbox()
+            ptbb.enlarge(pyx.unit.u_pt*2)
+            canvas.stroke(ptbb.path(),[pyx.color.rgb.black, pyx.deco.filled([bkcol])])
+            canvas.insert(pt)
+            for fname, fval, fdump in fields:
+                col = forecolor.next()
+                ft = pyx.text.text(XSTART, (YTXT-y)*YMUL, r"\font\cmssfont=cmss10\cmssfont{%s}" % tex_escape(fname.name))
+                if isinstance(fval, str):
+                    if len(fval) > 18:
+                        fval = fval[:18]+"[...]"
+                else:
+                    fval=""
+                vt = pyx.text.text(XSTART+3, (YTXT-y)*YMUL, r"\font\cmssfont=cmss10\cmssfont{%s}" % tex_escape(fval))
+                y += 1.0
+                if fdump:
+                    dt,target,last_shift,last_y = make_dump(fdump, last_shift, last_y, col, bkcol)
+
+                    dtb = dt.bbox()
+                    dtb=target
+                    vtb = vt.bbox()
+                    bxvt = make_box(vtb)
+                    bxdt = make_box(dtb)
+                    dtb.enlarge(pyx.unit.u_pt)
+                    try:
+                        if yd < 0:
+                            cnx = pyx.connector.curve(bxvt,bxdt,absangle1=0, absangle2=-90)
+                        else:
+                            cnx = pyx.connector.curve(bxvt,bxdt,absangle1=0, absangle2=90)
+                    except:
+                        pass
+                    else:
+                        canvas.stroke(cnx,[pyx.style.linewidth.thin,pyx.deco.earrow.small,col])
+                        
+                    canvas.insert(dt)
+                
+                canvas.insert(ft)
+                canvas.insert(vt)
+            last_y += layer_shift
+    
+        return canvas
+
+
+
+    def extract_padding(self, s):
+        """DEV: to be overloaded to extract current layer's padding. Return a couple of strings (actual layer, padding)"""
+        return s,None
+
+    def post_dissect(self, s):
+        """DEV: is called right after the current layer has been dissected"""
+        return s
+
+    def pre_dissect(self, s):
+        """DEV: is called right before the current layer is dissected"""
+        return s
+
+    def do_dissect(self, s):
+        flist = self.fields_desc[:]
+        flist.reverse()
+        raw = s
+        while s and flist:
+            f = flist.pop()
+            s,fval = f.getfield(self, s)
+            self.fields[f.name] = fval
+        assert(raw.endswith(s))
+        if s:
+            self.raw_packet_cache = raw[:-len(s)]
+        else:
+            self.raw_packet_cache = raw
+        self.explicit = 1
+        return s
+
+    def do_dissect_payload(self, s):
+        if s:
+            cls = self.guess_payload_class(s)
+            try:
+                p = cls(s, _internal=1, _underlayer=self)
+            except KeyboardInterrupt:
+                raise
+            except:
+                if conf.debug_dissector:
+                    if isinstance(cls,type) and issubclass(cls,Packet):
+                        log_runtime.error("%s dissector failed" % cls.name)
+                    else:
+                        log_runtime.error("%s.guess_payload_class() returned [%s]" % (self.__class__.__name__,repr(cls)))
+                    if cls is not None:
+                        raise
+                p = conf.raw_layer(s, _internal=1, _underlayer=self)
+            self.add_payload(p)
+
+    def dissect(self, s):
+        s = self.pre_dissect(s)
+
+        s = self.do_dissect(s)
+
+        s = self.post_dissect(s)
+            
+        payl,pad = self.extract_padding(s)
+        self.do_dissect_payload(payl)
+        if pad and conf.padding:
+            self.add_payload(conf.padding_layer(pad))
+
+
+    def guess_payload_class(self, payload):
+        """DEV: Guesses the next payload class from layer bonds. Can be overloaded to use a different mechanism."""
+        for t in self.aliastypes:
+            for fval, cls in t.payload_guess:
+                ok = 1
+                for k in fval.keys():
+                    if not hasattr(self, k) or fval[k] != self.getfieldval(k):
+                        ok = 0
+                        break
+                if ok:
+                    return cls
+        return self.default_payload_class(payload)
+    
+    def default_payload_class(self, payload):
+        """DEV: Returns the default payload class if nothing has been found by the guess_payload_class() method."""
+        return conf.raw_layer
+
+    def hide_defaults(self):
+        """Removes fields' values that are the same as default values."""
+        for k in self.fields.keys():
+            if self.default_fields.has_key(k):
+                if self.default_fields[k] == self.fields[k]:
+                    del(self.fields[k])
+        self.payload.hide_defaults()
+            
+    def clone_with(self, payload=None, **kargs):
+        pkt = self.__class__()
+        pkt.explicit = 1
+        pkt.fields = kargs
+        pkt.offset=self.offset
+        pkt.time = self.time
+        pkt.underlayer = self.underlayer
+        pkt.overload_fields = self.overload_fields.copy()
+        pkt.post_transforms = self.post_transforms
+        if payload is not None:
+            pkt.add_payload(payload)
+        return pkt
+        
+
+    def __iter__(self):
+        def loop(todo, done, self=self):
+            if todo:
+                eltname = todo.pop()
+                elt = self.getfieldval(eltname)
+                if not isinstance(elt, Gen):
+                    if self.get_field(eltname).islist:
+                        elt = SetGen([elt])
+                    else:
+                        elt = SetGen(elt)
+                for e in elt:
+                    done[eltname]=e
+                    for x in loop(todo[:], done):
+                        yield x
+            else:
+                if isinstance(self.payload,NoPayload):
+                    payloads = [None]
+                else:
+                    payloads = self.payload
+                for payl in payloads:
+                    done2=done.copy()
+                    for k in done2:
+                        if isinstance(done2[k], VolatileValue):
+                            done2[k] = done2[k]._fix()
+                    pkt = self.clone_with(payload=payl, **done2)
+                    yield pkt
+
+        if self.explicit:
+            todo = []
+            done = self.fields
+        else:
+            todo = [ k for (k,v) in itertools.chain(self.default_fields.iteritems(),
+                                                    self.overloaded_fields.iteritems())
+                     if isinstance(v, VolatileValue) ] + self.fields.keys()
+            done = {}
+        return loop(todo, done)
+
+    def __gt__(self, other):
+        """True if other is an answer from self (self ==> other)."""
+        if isinstance(other, Packet):
+            return other < self
+        elif type(other) is str:
+            return 1
+        else:
+            raise TypeError((self, other))
+    def __lt__(self, other):
+        """True if self is an answer from other (other ==> self)."""
+        if isinstance(other, Packet):
+            return self.answers(other)
+        elif type(other) is str:
+            return 1
+        else:
+            raise TypeError((self, other))
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return False
+        for f in self.fields_desc:
+            if f not in other.fields_desc:
+                return False
+            if self.getfieldval(f.name) != other.getfieldval(f.name):
+                return False
+        return self.payload == other.payload
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def hashret(self):
+        """DEV: returns a string that has the same value for a request and its answer."""
+        return self.payload.hashret()
+    def answers(self, other):
+        """DEV: true if self is an answer from other"""
+        if other.__class__ == self.__class__:
+            return self.payload.answers(other.payload)
+        return 0
+
+    def haslayer(self, cls):
+        """true if self has a layer that is an instance of cls. Superseded by "cls in self" syntax."""
+        if self.__class__ == cls or self.__class__.__name__ == cls:
+            return 1
+        for f in self.packetfields:
+            fvalue_gen = self.getfieldval(f.name)
+            if fvalue_gen is None:
+                continue
+            if not f.islist:
+                fvalue_gen = SetGen(fvalue_gen,_iterpacket=0)
+            for fvalue in fvalue_gen:
+                if isinstance(fvalue, Packet):
+                    ret = fvalue.haslayer(cls)
+                    if ret:
+                        return ret
+        return self.payload.haslayer(cls)
+
+
+    def getlayer(self, cls, nb=1, _track=None):
+        """Return the nb^th layer that is an instance of cls."""
+        if type(cls) is int:
+            nb = cls+1
+            cls = None
+        if type(cls) is str and "." in cls:
+            ccls,fld = cls.split(".",1)
+        else:
+            ccls,fld = cls,None
+        if cls is None or self.__class__ == cls or self.__class__.name == ccls:
+            if nb == 1:
+                if fld is None:
+                    return self
+                else:
+                    return self.getfieldval(fld)
+            else:
+                nb -=1
+        for f in self.packetfields:
+            fvalue_gen = self.getfieldval(f.name)
+            if fvalue_gen is None:
+                continue
+            if not f.islist:
+                fvalue_gen = SetGen(fvalue_gen,_iterpacket=0)
+            for fvalue in fvalue_gen:
+                if isinstance(fvalue, Packet):
+                    track=[]
+                    ret = fvalue.getlayer(cls, nb, _track=track)
+                    if ret is not None:
+                        return ret
+                    nb = track[0]
+        return self.payload.getlayer(cls,nb,_track=_track)
+
+    def firstlayer(self):
+        q = self
+        while q.underlayer is not None:
+            q = q.underlayer
+        return q
+
+    def __getitem__(self, cls):
+        if type(cls) is slice:
+            lname = cls.start
+            if cls.stop:
+                ret = self.getlayer(cls.start, cls.stop)
+            else:
+                ret = self.getlayer(cls.start)
+            if ret is None and cls.step is not None:
+                ret = cls.step
+        else:
+            lname=cls
+            ret = self.getlayer(cls)
+        if ret is None:
+            if type(lname) is Packet_metaclass:
+                lname = lname.__name__
+            elif type(lname) is not str:
+                lname = repr(lname)
+            raise IndexError("Layer [%s] not found" % lname)
+        return ret
+
+    def __delitem__(self, cls):
+        del(self[cls].underlayer.payload)
+
+    def __setitem__(self, cls, val):
+        self[cls].underlayer.payload = val
+    
+    def __contains__(self, cls):
+        """"cls in self" returns true if self has a layer which is an instance of cls."""
+        return self.haslayer(cls)
+
+    def route(self):
+        return (None,None,None)
+
+    def fragment(self, *args, **kargs):
+        return self.payload.fragment(*args, **kargs)
+    
+
+    def display(self,*args,**kargs):  # Deprecated. Use show()
+        """Deprecated. Use show() method."""
+        self.show(*args,**kargs)
+    def show(self, indent=3, lvl="", label_lvl=""):
+        """Prints a hierarchical view of the packet. "indent" gives the size of indentation for each layer."""
+        ct = conf.color_theme
+        print "%s%s %s %s" % (label_lvl,
+                              ct.punct("###["),
+                              ct.layer_name(self.name),
+                              ct.punct("]###"))
+        for f in self.fields_desc:
+            if isinstance(f, ConditionalField) and not f._evalcond(self):
+                continue
+            if isinstance(f, Emph) or f in conf.emph:
+                ncol = ct.emph_field_name
+                vcol = ct.emph_field_value
+            else:
+                ncol = ct.field_name
+                vcol = ct.field_value
+            fvalue = self.getfieldval(f.name)
+            if isinstance(fvalue, Packet) or (f.islist and f.holds_packets and type(fvalue) is list):
+                print "%s  \\%-10s\\" % (label_lvl+lvl, ncol(f.name))
+                fvalue_gen = SetGen(fvalue,_iterpacket=0)
+                for fvalue in fvalue_gen:
+                    fvalue.show(indent=indent, label_lvl=label_lvl+lvl+"   |")
+            else:
+                begn = "%s  %-10s%s " % (label_lvl+lvl,
+                                        ncol(f.name),
+                                        ct.punct("="),)
+                reprval = f.i2repr(self,fvalue)
+                if type(reprval) is str:
+                    reprval = reprval.replace("\n", "\n"+" "*(len(label_lvl)
+                                                              +len(lvl)
+                                                              +len(f.name)
+                                                              +4))
+                print "%s%s" % (begn,vcol(reprval))
+        self.payload.show(indent=indent, lvl=lvl+(" "*indent*self.show_indent), label_lvl=label_lvl)
+    def show2(self):
+        """Prints a hierarchical view of an assembled version of the packet, so that automatic fields are calculated (checksums, etc.)"""
+        self.__class__(str(self)).show()
+
+    def sprintf(self, fmt, relax=1):
+        """sprintf(format, [relax=1]) -> str
+where format is a string that can include directives. A directive begins and
+ends by % and has the following format %[fmt[r],][cls[:nb].]field%.
+
+fmt is a classic printf directive, "r" can be appended for raw substitution
+(ex: IP.flags=0x18 instead of SA), nb is the number of the layer we want
+(ex: for IP/IP packets, IP:2.src is the src of the upper IP layer).
+Special case : "%.time%" is the creation time.
+Ex : p.sprintf("%.time% %-15s,IP.src% -> %-15s,IP.dst% %IP.chksum% "
+               "%03xr,IP.proto% %r,TCP.flags%")
+
+Moreover, the format string can include conditionnal statements. A conditionnal
+statement looks like : {layer:string} where layer is a layer name, and string
+is the string to insert in place of the condition if it is true, i.e. if layer
+is present. If layer is preceded by a "!", the result si inverted. Conditions
+can be imbricated. A valid statement can be :
+  p.sprintf("This is a{TCP: TCP}{UDP: UDP}{ICMP:n ICMP} packet")
+  p.sprintf("{IP:%IP.dst% {ICMP:%ICMP.type%}{TCP:%TCP.dport%}}")
+
+A side effect is that, to obtain "{" and "}" characters, you must use
+"%(" and "%)".
+"""
+
+        escape = { "%": "%",
+                   "(": "{",
+                   ")": "}" }
+
+
+        # Evaluate conditions 
+        while "{" in fmt:
+            i = fmt.rindex("{")
+            j = fmt[i+1:].index("}")
+            cond = fmt[i+1:i+j+1]
+            k = cond.find(":")
+            if k < 0:
+                raise Scapy_Exception("Bad condition in format string: [%s] (read sprintf doc!)"%cond)
+            cond,format = cond[:k],cond[k+1:]
+            res = False
+            if cond[0] == "!":
+                res = True
+                cond = cond[1:]
+            if self.haslayer(cond):
+                res = not res
+            if not res:
+                format = ""
+            fmt = fmt[:i]+format+fmt[i+j+2:]
+
+        # Evaluate directives
+        s = ""
+        while "%" in fmt:
+            i = fmt.index("%")
+            s += fmt[:i]
+            fmt = fmt[i+1:]
+            if fmt and fmt[0] in escape:
+                s += escape[fmt[0]]
+                fmt = fmt[1:]
+                continue
+            try:
+                i = fmt.index("%")
+                sfclsfld = fmt[:i]
+                fclsfld = sfclsfld.split(",")
+                if len(fclsfld) == 1:
+                    f = "s"
+                    clsfld = fclsfld[0]
+                elif len(fclsfld) == 2:
+                    f,clsfld = fclsfld
+                else:
+                    raise Scapy_Exception
+                if "." in clsfld:
+                    cls,fld = clsfld.split(".")
+                else:
+                    cls = self.__class__.__name__
+                    fld = clsfld
+                num = 1
+                if ":" in cls:
+                    cls,num = cls.split(":")
+                    num = int(num)
+                fmt = fmt[i+1:]
+            except:
+                raise Scapy_Exception("Bad format string [%%%s%s]" % (fmt[:25], fmt[25:] and "..."))
+            else:
+                if fld == "time":
+                    val = time.strftime("%H:%M:%S.%%06i", time.localtime(self.time)) % int((self.time-int(self.time))*1000000)
+                elif cls == self.__class__.__name__ and hasattr(self, fld):
+                    if num > 1:
+                        val = self.payload.sprintf("%%%s,%s:%s.%s%%" % (f,cls,num-1,fld), relax)
+                        f = "s"
+                    elif f[-1] == "r":  # Raw field value
+                        val = getattr(self,fld)
+                        f = f[:-1]
+                        if not f:
+                            f = "s"
+                    else:
+                        val = getattr(self,fld)
+                        if fld in self.fieldtype:
+                            val = self.fieldtype[fld].i2repr(self,val)
+                else:
+                    val = self.payload.sprintf("%%%s%%" % sfclsfld, relax)
+                    f = "s"
+                s += ("%"+f) % val
+            
+        s += fmt
+        return s
+
+    def mysummary(self):
+        """DEV: can be overloaded to return a string that summarizes the layer.
+           Only one mysummary() is used in a whole packet summary: the one of the upper layer,
+           except if a mysummary() also returns (as a couple) a list of layers whose
+           mysummary() must be called if they are present."""
+        return ""
+
+    def _do_summary(self):
+        found,s,needed = self.payload._do_summary()
+        if s:
+            s = " / "+s
+        ret = ""
+        if not found or self.__class__ in needed:
+            ret = self.mysummary()
+            if type(ret) is tuple:
+                ret,n = ret
+                needed += n
+        if ret or needed:
+            found = 1
+        if not ret:
+            ret = self.__class__.__name__
+        if self.__class__ in conf.emph:
+            impf = []
+            for f in self.fields_desc:
+                if f in conf.emph:
+                    impf.append("%s=%s" % (f.name, f.i2repr(self, self.getfieldval(f.name))))
+            ret = "%s [%s]" % (ret," ".join(impf))
+        ret = "%s%s" % (ret,s)
+        return found,ret,needed
+
+    def summary(self, intern=0):
+        """Prints a one line summary of a packet."""
+        found,s,needed = self._do_summary()
+        return s
+
+    
+    def lastlayer(self,layer=None):
+        """Returns the uppest layer of the packet"""
+        return self.payload.lastlayer(self)
+
+    def decode_payload_as(self,cls):
+        """Reassembles the payload and decode it using another packet class"""
+        s = str(self.payload)
+        self.payload = cls(s, _internal=1, _underlayer=self)
+        pp = self
+        while pp.underlayer is not None:
+            pp = pp.underlayer
+        self.payload.dissection_done(pp)
+
+    def libnet(self):
+        """Not ready yet. Should give the necessary C code that interfaces with libnet to recreate the packet"""
+        print "libnet_build_%s(" % self.__class__.name.lower()
+        det = self.__class__(str(self))
+        for f in self.fields_desc:
+            val = det.getfieldval(f.name)
+            if val is None:
+                val = 0
+            elif type(val) is int:
+                val = str(val)
+            else:
+                val = '"%s"' % str(val)
+            print "\t%s, \t\t/* %s */" % (val,f.name)
+        print ");"
+    def command(self):
+        """Returns a string representing the command you have to type to obtain the same packet"""
+        f = []
+        for fn,fv in self.fields.items():
+            fld = self.get_field(fn)
+            if isinstance(fv, Packet):
+                fv = fv.command()
+            elif fld.islist and fld.holds_packets and type(fv) is list:
+                fv = "[%s]" % ",".join( map(Packet.command, fv))
+            else:
+                fv = repr(fv)
+            f.append("%s=%s" % (fn, fv))
+        c = "%s(%s)" % (self.__class__.__name__, ", ".join(f))
+        pc = self.payload.command()
+        if pc:
+            c += "/"+pc
+        return c                    
+
+class NoPayload(Packet):
+    def __new__(cls, *args, **kargs):
+        singl = cls.__dict__.get("__singl__")
+        if singl is None:
+            cls.__singl__ = singl = Packet.__new__(cls)
+            Packet.__init__(singl)
+        return singl
+    def __init__(self, *args, **kargs):
+        pass
+    def dissection_done(self,pkt):
+        return
+    def add_payload(self, payload):
+        raise Scapy_Exception("Can't add payload to NoPayload instance")
+    def remove_payload(self):
+        pass
+    def add_underlayer(self,underlayer):
+        pass
+    def remove_underlayer(self,other):
+        pass
+    def copy(self):
+        return self
+    def __repr__(self):
+        return ""
+    def __str__(self):
+        return ""
+    def __nonzero__(self):
+        return False
+    def do_build(self,result):
+        return ""
+    def build(self):
+        return ""
+    def build_padding(self):
+        return ""
+    def build_done(self, p):
+        return p
+    def build_ps(self, internal=0):
+        return "",[]
+    def getfieldval(self, attr):
+        raise AttributeError(attr)
+    def getfield_and_val(self, attr):
+        raise AttributeError(attr)
+    def setfieldval(self, attr, val):
+        raise AttributeError(attr)
+    def delfieldval(self, attr):
+        raise AttributeError(attr)
+    def __getattr__(self, attr):
+        if attr in self.__dict__:
+            return self.__dict__[attr]
+        elif attr in self.__class__.__dict__:
+            return self.__class__.__dict__[attr]
+        else:
+            raise AttributeError, attr
+    def hide_defaults(self):
+        pass
+    def __iter__(self):
+        return iter([])
+    def __eq__(self, other):
+        if isinstance(other, NoPayload):
+            return True
+        return False
+    def hashret(self):
+        return ""
+    def answers(self, other):
+        return isinstance(other, NoPayload) or isinstance(other, conf.padding_layer)
+    def haslayer(self, cls):
+        return 0
+    def getlayer(self, cls, nb=1, _track=None):
+        if _track is not None:
+            _track.append(nb)
+        return None
+    def fragment(self, *args, **kargs):
+        raise Scapy_Exception("cannot fragment this packet")        
+    def show(self, indent=3, lvl="", label_lvl=""):
+        pass
+    def sprintf(self, fmt, relax):
+        if relax:
+            return "??"
+        else:
+            raise Scapy_Exception("Format not found [%s]"%fmt)
+    def _do_summary(self):
+        return 0,"",[]
+    def lastlayer(self,layer):
+        return layer
+    def command(self):
+        return ""
+    
+####################
+## packet classes ##
+####################
+
+            
+class Raw(Packet):
+    name = "Raw"
+    fields_desc = [ StrField("load", "") ]
+    def answers(self, other):
+        return 1
+#        s = str(other)
+#        t = self.load
+#        l = min(len(s), len(t))
+#        return  s[:l] == t[:l]
+    def mysummary(self):
+        cs = conf.raw_summary
+        if cs:
+            if callable(cs):
+                return "Raw %s" % cs(self.load)
+            else:
+                return "Raw %r" % self.load
+        return Packet.mysummary(self)
+        
+class Padding(Raw):
+    name = "Padding"
+    def self_build(self):
+        return ""
+    def build_padding(self):
+        return (self.load if self.raw_packet_cache is None
+                else self.raw_packet_cache) + self.payload.build_padding()
+
+conf.raw_layer = Raw
+conf.padding_layer = Padding
+if conf.default_l2 is None:
+    conf.default_l2 = Raw
+
+#################
+## Bind layers ##
+#################
+
+
+def bind_bottom_up(lower, upper, __fval=None, **fval):
+    if __fval is not None:
+        fval.update(__fval)
+    lower.payload_guess = lower.payload_guess[:]
+    lower.payload_guess.append((fval, upper))
+    
+
+def bind_top_down(lower, upper, __fval=None, **fval):
+    if __fval is not None:
+        fval.update(__fval)
+    upper.overload_fields = upper.overload_fields.copy()
+    upper.overload_fields[lower] = fval
+    
+@conf.commands.register
+def bind_layers(lower, upper, __fval=None, **fval):
+    """Bind 2 layers on some specific fields' values"""
+    if __fval is not None:
+        fval.update(__fval)
+    bind_top_down(lower, upper, **fval)
+    bind_bottom_up(lower, upper, **fval)
+
+def split_bottom_up(lower, upper, __fval=None, **fval):
+    if __fval is not None:
+        fval.update(__fval)
+    def do_filter((f,u),upper=upper,fval=fval):
+        if u != upper:
+            return True
+        for k in fval:
+            if k not in f or f[k] != fval[k]:
+                return True
+        return False
+    lower.payload_guess = filter(do_filter, lower.payload_guess)
+        
+def split_top_down(lower, upper, __fval=None, **fval):
+    if __fval is not None:
+        fval.update(__fval)
+    if lower in upper.overload_fields:
+        ofval = upper.overload_fields[lower]
+        for k in fval:
+            if k not in ofval or ofval[k] != fval[k]:
+                return
+        upper.overload_fields = upper.overload_fields.copy()
+        del(upper.overload_fields[lower])
+
+@conf.commands.register
+def split_layers(lower, upper, __fval=None, **fval):
+    """Split 2 layers previously bound"""
+    if __fval is not None:
+        fval.update(__fval)
+    split_bottom_up(lower, upper, **fval)
+    split_top_down(lower, upper, **fval)
+
+
+@conf.commands.register
+def ls(obj=None):
+    """List  available layers, or infos on a given layer"""
+    if obj is None:
+        
+        import __builtin__
+        all = __builtin__.__dict__.copy()
+        all.update(globals())
+        objlst = sorted(conf.layers, key=lambda x:x.__name__)
+        for o in objlst:
+            print "%-10s : %s" %(o.__name__,o.name)
+    else:
+        if isinstance(obj, type) and issubclass(obj, Packet):
+            for f in obj.fields_desc:
+                print "%-10s : %-20s = (%s)" % (f.name, f.__class__.__name__,  repr(f.default))
+        elif isinstance(obj, Packet):
+            for f in obj.fields_desc:
+                print "%-10s : %-20s = %-15s (%s)" % (f.name, f.__class__.__name__, repr(getattr(obj,f.name)), repr(f.default))
+            if not isinstance(obj.payload, NoPayload):
+                print "--"
+                ls(obj.payload)
+                
+
+        else:
+            print "Not a packet class. Type 'ls()' to list packet classes."
+
+
+    
+#############
+## Fuzzing ##
+#############
+
+@conf.commands.register
+def fuzz(p, _inplace=0):
+    """Transform a layer into a fuzzy layer by replacing some default values by random objects"""
+    if not _inplace:
+        p = p.copy()
+    q = p
+    while not isinstance(q, NoPayload):
+        for f in q.fields_desc:
+            if isinstance(f, PacketListField):
+                for r in getattr(q, f.name):
+                    print "fuzzing", repr(r)
+                    fuzz(r, _inplace=1)
+            elif f.default is not None:
+                rnd = f.randval()
+                if rnd is not None:
+                    q.default_fields[f.name] = rnd
+        q = q.payload
+    return p
+
+
+