first scapy version

3 files changed, 1676 insertions, 1 deletions

diff --git a/scripts/automation/trex_control_plane/client_utils/external_packages.py b/scripts/automation/trex_control_plane/client_utils/external_packages.py
index c41f8f2f..c682dc18 100755
--- a/scripts/automation/trex_control_plane/client_utils/external_packages.py
+++ b/scripts/automation/trex_control_plane/client_utils/external_packages.py
@@ -10,7 +10,8 @@ PATH_TO_PYTHON_LIB  = os.path.abspath(os.path.join(ROOT_PATH, os.pardir, os.pard
 
 CLIENT_UTILS_MODULES = ['dpkt-1.8.6',
                         'yaml-3.11',
-                        'texttable-0.8.4'
+                        'texttable-0.8.4',
+                        'scapy-2.3.1'
                         ]
 
 def import_client_utils_modules():
diff --git a/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder.py b/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder.py
new file mode 100644
index 00000000..b4bc55be
--- /dev/null
+++ b/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder.py
@@ -0,0 +1,837 @@
+import external_packages
+import random
+import string
+import struct
+import socket       
+import json
+import yaml
+import binascii
+
+
+from scapy.all import *
+
+
+
+class CTRexPacketBuildException(Exception):
+    """
+    This is the general Packet Building error exception class.
+    """
+    def __init__(self, code, message):
+        self.code = code
+        self.message = message
+
+    def __str__(self):
+        return self.__repr__()
+
+    def __repr__(self):
+        return u"[errcode:%r] %r" % (self.code, self.message)
+
+################################################################################################
+
+def ipv4_str_to_num (ipv4_buffer):
+
+    assert(type(ipv4_buffer)==str);
+    assert(len(ipv4_buffer)==4);
+    res=0;
+    shift=24
+    for i in ipv4_buffer:
+       res = res + (ord(i)<<shift);
+       shift =shift -8
+    return res
+
+
+
+def is_valid_ipv4(ip_addr):
+    """
+    return buffer in network order 
+    """
+    if  type(ip_addr)==str and len(ip_addr) == 4:
+        return ip_addr
+
+    if  type(ip_addr)==int :
+        ip_addr = socket.inet_ntoa(struct.pack("!I", ip_addr)) 
+
+    try:
+        return socket.inet_pton(socket.AF_INET, ip_addr)
+    except AttributeError:  # no inet_pton here, sorry
+        return socket.inet_aton(ip_addr)
+    except socket.error:  # not a valid address
+        raise CTRexPacketBuildException(-10,"not valid ipv4 format");
+
+
+class CTRexScriptsBase(object):
+    """
+    VM Script base class 
+    """
+    def clone (self):
+        return copy.deepcopy(self)
+
+
+class CTRexScFieldRangeBase(CTRexScriptsBase):
+
+    FILED_TYPES = ["inc","dec","rand"]  
+
+    def __init__(self, field_name,
+                       field_type
+                            ):
+        super(CTRexScFieldRangeBase, self).__init__()
+        self.field_name =field_name
+        self.field_type =field_type
+        if not self.field_type in CTRexScFieldRangeBase.FILED_TYPES :
+            raise CTRexPacketBuildException(-12,"field type should be in [inc,dec,rand] ");
+
+
+class CTRexScFieldRangeValue(CTRexScFieldRangeBase):
+    """
+    range of field value
+    """
+    def __init__(self, field_name, 
+                       field_type,
+                       min_val,
+                       max_val
+                           ):
+        super(CTRexScFieldRangeValue, self).__init__(field_name,field_type)
+        self.min_val =min_val;
+        self.max_val =max_val;
+        if min_val > max_val:
+            raise CTRexPacketBuildException(-12,"min is greater than max ");
+        if min_val == max_val:
+            raise CTRexPacketBuildException(-13,"min value is equal to max value, you can't use this type of range ");
+
+
+class CTRexScIpv4SimpleRange(CTRexScFieldRangeBase):
+    """
+    range of ipv4 ip
+    """
+    def __init__(self, field_name,field_type,min_ip, max_ip):
+        super(CTRexScIpv4SimpleRange, self).__init__(field_name,field_type)
+        self.min_ip = min_ip
+        self.max_ip = max_ip
+        mmin=ipv4_str_to_num (is_valid_ipv4(min_ip))
+        mmax=ipv4_str_to_num (is_valid_ipv4(max_ip))
+        if  mmin > mmax :
+            raise CTRexPacketBuildException(-11,"CTRexScIpv4SimpleRange m_min ip is bigger than max ");
+
+
+class CTRexScIpv4TupleGen(CTRexScriptsBase):
+    """
+    range tuple 
+    """
+    FLAGS_ULIMIT_FLOWS =1
+
+    def __init__(self, min_ipv4, max_ipv4,num_flows=100000,min_port=1025,max_port=65535,flags=0):
+        super(CTRexScIpv4TupleGen, self).__init__()
+        self.min_ip = min_ipv4
+        self.max_ip = max_ipv4
+        mmin=ipv4_str_to_num (is_valid_ipv4(min_ipv4))
+        mmax=ipv4_str_to_num (is_valid_ipv4(max_ipv4))
+        if  mmin > mmax :
+            raise CTRexPacketBuildException(-11,"CTRexScIpv4SimpleRange m_min ip is bigger than max ");
+
+        self.num_flows=num_flows;
+
+        self.min_port =min_port
+        self.max_port =max_port
+        self.flags =   flags
+
+
+class CTRexScTrimPacketSize(CTRexScriptsBase):
+    """
+    trim packet size. field type is CTRexScFieldRangeBase.FILED_TYPES = ["inc","dec","rand"]  
+    """
+    def __init__(self,field_type="rand",min_pkt_size=None, max_pkt_size=None):
+        super(CTRexScTrimPacketSize, self).__init__()
+        self.field_type = field_type
+        self.min_pkt_size = min_pkt_size
+        self.max_pkt_size = max_pkt_size
+        if max_pkt_size != None and min_pkt_size !=None :
+            if min_pkt_size == max_pkt_size:
+                raise CTRexPacketBuildException(-11,"CTRexScTrimPacketSize min_pkt_size is the same as max_pkt_size ");
+
+            if min_pkt_size > max_pkt_size:
+                raise CTRexPacketBuildException(-11,"CTRexScTrimPacketSize min_pkt_size is bigger than max_pkt_size ");
+
+class CTRexScRaw(CTRexScriptsBase):
+    """
+    raw instructions 
+    """
+    def __init__(self,list_of_commands=None):
+        super(CTRexScRaw, self).__init__()
+        if list_of_commands==None:
+            self.commands =[]
+        else:
+            self.commands = list_of_commands
+
+    def add_cmd (self,cmd):
+        self.commands.append(cmd)
+
+
+
+################################################################################################
+# VM raw instructions 
+################################################################################################
+
+class CTRexVmInsBase(object):
+    """
+    instruction base
+    """
+    def __init__(self,ins_type):
+        self.type = ins_type
+        assert(type(ins_type)==str);
+
+class CTRexVmInsFixIpv4(CTRexVmInsBase):
+    def __init__(self,offset):
+        super(CTRexVmInsFixIpv4, self).__init__("fix_checksum_ipv4")
+        self.offset = offset
+        assert(type(offset)==int);
+
+
+class CTRexVmInsFlowVar(CTRexVmInsBase):
+    #TBD add more validation tests
+
+    OPERATIONS =["inc", "dec", "random"]
+    VALID_SIZES =[1,2,4,8]
+
+    def __init__(self,fv_name,size,op,init_val,min_val,max_val):
+        super(CTRexVmInsFlowVar, self).__init__("flow_var")
+        self.name =fv_name;
+        assert(type(fv_name)==str);
+        self.size =size
+        self.op =op
+        self.init_val=init_val
+        assert(type(init_val)==int);
+        self.min_val=min_val
+        assert(type(min_val)==int);
+        self.max_val=max_val
+        assert(type(max_val)==int);
+
+class CTRexVmInsWrFlowVar(CTRexVmInsBase):
+    def __init__(self,fv_name,pkt_offset,add_val=0,is_big=True):
+        super(CTRexVmInsWrFlowVar, self).__init__("write_flow_var")
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.pkt_offset =pkt_offset
+        assert(type(pkt_offset)==int);
+        self.add_val =add_val
+        assert(type(add_val)==int);
+        self.is_big =is_big;
+        assert(type(is_big)==bool);
+
+class CTRexVmInsTrimPktSize(CTRexVmInsBase):
+    def __init__(self,fv_name):
+        super(CTRexVmInsTrimPktSize, self).__init__("trim_pkt_size")
+        self.fv_name =fv_name
+        assert(type(fv_name)==str);
+
+class CTRexVmInsTupleGen(CTRexVmInsBase):
+    def __init__(self,fv_name,ip_min,ip_max,port_min,port_max,limit_flows,flags=0):
+        super(CTRexVmInsTupleGen, self).__init__("tuple_flow_var")
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.ip_min = ip_min;
+        self.ip_max = ip_max;
+        self.port_min = port_min;
+        self.port_max = port_max;
+        self.limit_flows = limit_flows;
+        self.flags       =flags;
+
+
+################################################################################################
+# 
+class CTRexVmEngine(object):
+
+       def __init__(self):
+            """
+            inlcude list of instruction
+            """
+            super(CTRexVmEngine, self).__init__()
+            self.ins=[]
+            self.split_by_var = ''
+
+       # return as json 
+       def get_json (self):
+           inst_array = [];
+           # dump it as dict
+           for obj in self.ins:
+               inst_array.append(obj.__dict__);
+
+           return {'instructions': inst_array, 'split_by_var': self.split_by_var}
+
+       def add_ins (self,ins):
+           #assert issubclass(ins, CTRexVmInsBase)
+           self.ins.append(ins);
+
+       def dump (self):
+           cnt=0;
+           for obj in self.ins:
+               print "ins",cnt
+               cnt = cnt +1
+               print obj.__dict__
+
+       def dump_bjson (self):
+          print json.dumps(self.get_json(), sort_keys=True, indent=4)
+
+       def dump_as_yaml (self):
+          print yaml.dump(self.get_json(), default_flow_style=False)
+
+
+
+################################################################################################
+
+class CTRexScapyPktUtl(object):
+
+    def __init__(self,scapy_pkt):
+        self.pkt = scapy_pkt
+
+    def pkt_iter (self):
+        p=self.pkt;
+        while True:
+            yield p
+            p=p.payload
+            if p ==None or isinstance(p,NoPayload):
+                break;
+
+    def get_list_iter (self):
+        l=list(self.pkt_iter())
+        return l
+
+
+    def get_pkt_layers (self):
+        """
+        return string 'IP:UDP:TCP'
+        """
+        l=self.get_list_iter ();
+        l1=map(lambda p: p.name,l );
+        return ":".join(l1);
+
+    def _layer_offset(self,name,cnt=0):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        save_cnt=cnt
+        for pkt in self.pkt_iter ():
+            if pkt.name == name:
+                if cnt==0:
+                    return (pkt, pkt.offset)
+                else:
+                    cnt=cnt -1
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d" % (name,save_cnt)));
+
+
+    def layer_offset(self,name,cnt=0):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        save_cnt=cnt
+        for pkt in self.pkt_iter ():
+            if pkt.name == name:
+                if cnt==0:
+                    return pkt.offset
+                else:
+                    cnt=cnt -1
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d" % (name,save_cnt)));
+
+    def get_field_offet(self,layer,layer_cnt,field_name):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        t=self._layer_offset(layer,layer_cnt);
+        l_offset=t[1];
+        layer_pkt=t[0]
+
+        #layer_pkt.dump_fields_offsets ()
+
+        for f in layer_pkt.fields_desc:
+            if f.name == field_name:
+                return (l_offset+f.offset,f.get_size_bytes ());
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d." % (name,save_cnt,field_name)));
+
+    def  get_layer_offet_by_str(self,layer_des):
+        """
+        return layer offset by string  
+
+        IP:0
+        IP:1
+        return offset
+
+        """
+        l1=layer_des.split(":")
+        layer=""
+        layer_cnt=0;
+
+        if len(l1)==1:
+            layer=l1[0];
+        else:
+            layer=l1[0];
+            layer_cnt=int(l1[1]);
+
+        return self.layer_offset(layer,layer_cnt)
+
+
+
+    def  get_field_offet_by_str(self,field_des):
+        """
+        return field_des (offset,size) layer:cnt.field 
+        for example 
+
+        IP.src
+        IP:0.src  (first IP.src like IP.src)
+        for example IP:1.src  for internal IP
+
+        return (offset, size) as tuple 
+
+        """
+
+        s=field_des.split(".");
+        if len(s)!=2:
+            raise CTRexPacketBuildException(-11,("field desription should be layer:cnt.field e.g IP.src or IP:1.src "));
+
+
+        layer_ex = s[0]
+        field = s[1]
+
+        l1=layer_ex.split(":")
+        layer=""
+        layer_cnt=0;
+
+        if len(l1)==1:
+            layer=l1[0];
+        else:
+            layer=l1[0];
+            layer_cnt=int(l1[1]);
+
+        return self.get_field_offet(layer,layer_cnt,field)
+
+    def has_IPv4 (self):
+        return self.pkt.has_layer("IP");
+
+    def has_IPv6 (self):
+        return self.pkt.has_layer("IPv6");
+
+    def has_UDP (self):
+        return self.pkt.has_layer("UDP");
+
+################################################################################################
+
+class CTRexVmDescBase(object):
+    """
+    instruction base
+    """
+    def __init__(self):
+       pass;
+
+    def get_obj (self):
+        return self;
+
+    def get_json (self):
+        return self.get_obj().__dict__
+
+    def dump_bjson (self):
+       print json.dumps(self.get_json(), sort_keys=True, indent=4)
+
+    def dump_as_yaml (self):
+       print yaml.dump(self.get_json(), default_flow_style=False)
+
+
+    def get_var_name(self):
+        '''
+          virtual function return the varible name if exists
+        ''' 
+        return None
+
+    def compile(self,parent): 
+        '''
+          virtual function to take parent than has function name_to_offset
+        ''' 
+        pass;
+
+
+def valid_fv_size (size):
+    if not (size in CTRexVmInsFlowVar.VALID_SIZES):
+        raise CTRexPacketBuildException(-11,("flow var has not valid size %d ") % size  );
+
+def valid_fv_ops (op):
+    if not (op in CTRexVmInsFlowVar.OPERATIONS):
+        raise CTRexPacketBuildException(-11,("flow var does not have a valid op %s ") % op  );
+
+def convert_val (val):
+    if type(val) == int:
+        return val
+    else:
+        if type(val) == str:
+          return ipv4_str_to_num (is_valid_ipv4(val))
+        else:
+            raise CTRexPacketBuildException(-11,("init val not valid %s ") % val  );
+
+
+class CTRexVmDescFlowVar(CTRexVmDescBase):
+    def __init__(self,name,init_val=0,min_val=0,max_val=255,size=4,op="inc"):
+        super(CTRexVmDescFlowVar, self).__init__()
+        self.name = name;
+        assert(type(name)==str);
+        self.size =size
+        valid_fv_size(size)
+        self.op =op
+        valid_fv_ops (op)
+        self.init_val = convert_val (init_val)
+        self.min_val  = convert_val (min_val);
+        self.max_val  = convert_val (max_val)
+
+        if self.min_val > self.max_val :
+            raise CTRexPacketBuildException(-11,("max %d is lower than min %d ") % (self.max_val,self.min_val)  );
+
+    def get_obj (self):
+        return CTRexVmInsFlowVar(self.name,self.size,self.op,self.init_val,self.min_val,self.max_val);
+
+    def get_var_name(self):
+        return self.name
+
+
+class CTRexVmDescFixIpv4(CTRexVmDescBase):
+    def __init__(self,offset):
+        super(CTRexVmDescFixIpv4, self).__init__()
+        self.offset = offset; # could be a name of offset 
+
+    def get_obj (self):
+        return CTRexVmInsFixIpv4(self.offset);
+
+    def compile(self,parent): 
+        if type(self.offset)==str:
+            self.offset = parent._pkt_layer_offset(self.offset);
+
+class CTRexVmDescWrFlowVar(CTRexVmDescBase):
+    def __init__(self,fv_name,pkt_offset,add_val=0,is_big=True):
+        super(CTRexVmDescWrFlowVar, self).__init__()
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.pkt_offset =pkt_offset
+        self.add_val =add_val
+        assert(type(add_val)==int);
+        self.is_big =is_big;
+        assert(type(is_big)==bool);
+
+    def get_obj (self):
+            return  CTRexVmInsWrFlowVar(self.name,self.pkt_offset,self.add_val,self.is_big)
+
+    def compile(self,parent): 
+        if type(self.pkt_offset)==str:
+            t=parent._name_to_offset(self.pkt_offset)
+            self.pkt_offset = t[0]
+
+
+################################################################################################
+
+
+class CScapyTRexPktBuilder(object):
+
+    """
+    This class defines the TRex API of building a packet using dpkt package.
+    Using this class the user can also define how TRex will handle the packet by specifying the VM setting.
+    """
+    def __init__(self):
+        """
+        Instantiate a CTRexPktBuilder object
+
+        :parameters:
+             None
+
+        """
+        super(CScapyTRexPktBuilder, self).__init__()
+        self._pkt = None # scapy packet 
+        self.vm_scripts = [] # list of high level instructions
+        self.vm_low_level = None
+        self.metadata=""
+
+    def get_vm_data(self):
+        """
+        Dumps the instructions 
+
+        :parameters:
+            None
+
+        :return:
+            + json object of instructions
+
+        """
+
+        return self.vm_low_level.get_json () 
+
+    def dump_pkt(self):
+        """
+        Dumps the packet as a decimal array of bytes (each item x gets value between 0-255)
+
+        :parameters:
+            None
+
+        :return:
+            + packet representation as array of bytes
+
+        :raises:
+            + :exc:`CTRexPktBuilder.EmptyPacketError`, in case packet is empty.
+
+        """
+
+        assert(self.pkt);
+
+        pkt_in_hex = binascii.hexlify(str(self.pkt))
+        return {"binary": [int(pkt_in_hex[i:i+2], 16)
+                           for i in range(0, len(pkt_in_hex), 2)],
+                "meta": self.metadata}
+
+
+    def add_command (self,script):
+        self.vm_scripts.append(script.clone());
+
+    def dump_scripts (self):
+        self.vm_low_level.dump_as_yaml ()
+
+    def set_packet (self,pkt):
+        """
+        Scapy packet   Ether()/IP(src="16.0.0.1",dst="48.0.0.1")/UDP(dport=12,sport=1025)/IP()/"A"*10
+        """
+        self.pkt =pkt;
+
+
+    def compile (self):
+        self.vm_low_level=CTRexVmEngine()
+        assert(self.pkt);
+        self.pkt.build();
+
+        
+        for sc in self.vm_scripts:
+            if isinstance(sc, CTRexScRaw):
+                self._compile_raw (sc)
+
+        #for obj in self.vm_scripts:
+        #    # tuple gen script 
+        #    if isinstance(obj, CTRexScIpv4TupleGen)
+        #        self._add_tuple_gen(tuple_gen)
+
+    ####################################################
+    # private 
+
+    def _compile_raw (self,obj):
+
+        # make sure we have varibles once 
+        vars={};
+        for desc in obj.commands:
+            print desc.__dict__
+            var_name =  desc.get_var_name()
+            print var_name
+            if var_name :
+                if vars.has_key(var_name):
+                    raise CTRexPacketBuildException(-11,("varible %s define twice ") % (var_name)  );
+                else:
+                    vars[var_name]=1
+            desc.compile(self);
+
+        for desc in obj.commands:
+            self.vm_low_level.add_ins(desc.get_obj());
+
+
+    def _pkt_layer_offset (self,layer_name):
+        assert(self.pkt != None);
+        p_utl=CTRexScapyPktUtl(self.pkt);
+        return p_utl.get_layer_offet_by_str(layer_name)
+
+    def _name_to_offset(self,field_name):
+        assert(self.pkt != None);
+        p_utl=CTRexScapyPktUtl(self.pkt);
+        return p_utl.get_field_offet_by_str(field_name)
+
+    def  _add_tuple_gen(self,tuple_gen):
+
+        pass;
+
+
+
+################################################################################################
+# tests 
+################################################################################################
+# what should I do 
+# 1. iterator on the headers 
+# 2. do I have one IP? 
+# 3. offset of the UDP/TCP?
+# offset of each field inside the packet ? 
+
+def test_vm1 ():
+    a=CTRexVmDescFlowVar(name="a",min_val=0,max_val=255,init_val=0,size=4,op="inc");
+    a.dump_as_yaml ()
+    a.dump_bjson()
+
+    a=CTRexVmDescFlowVar(name="a",min_val="10.0.0.1",max_val="10.0.0.10",init_val="10.0.0.1",size=4,op="inc");
+    a.dump_as_yaml ()
+    a.dump_bjson()
+
+    raw = CTRexScRaw()
+    raw.add_cmd( CTRexVmDescFlowVar(name="a",min_val=0,max_val=255,init_val=0,size=4,op="inc") )
+    raw.add_cmd( CTRexVmDescFixIpv4(offset = "IP") )
+    raw.add_cmd( CTRexVmDescWrFlowVar (fv_name="a",pkt_offset= "IP.src") )
+
+
+    raw1 = CTRexScRaw( [ CTRexVmDescFlowVar(name="a",min_val="16.0.0.1",max_val="16.0.0.10",init_val="16.0.0.1",size=4,op="inc"),
+                          CTRexVmDescWrFlowVar (fv_name="a",pkt_offset= "IP.src"),
+                          CTRexVmDescFixIpv4(offset = "IP")]
+                      );
+
+    pkt_builder = CScapyTRexPktBuilder();
+
+    py='5'*128
+    pkt=Ether()/ \
+             IP(src="16.0.0.1",dst="48.0.0.1")/ \
+             UDP(dport=12,sport=1025)/IP()/py
+
+    # set packet 
+    pkt_builder.set_packet(pkt);
+    pkt_builder.add_command ( raw1 )
+    pkt_builder.compile();
+
+    pkt_builder.dump_scripts ()
+
+    print pkt_builder.dump_pkt()
+    print pkt_builder.get_vm_data()
+
+    print "hey"
+
+
+
+
+
+
+
+def test_udp ():
+    py='5'*128
+    p1=Ether()/ \
+             IP(src="16.0.0.1",dst="48.0.0.1")/ \
+             UDP(dport=12,sport=1025)/IP()/py
+
+    p1.build();
+    #print p1.haslayer("UDP.tos:1");
+
+    #pkt_utl=CTRexScapyPktUtl(p1);
+    #pkt_utl.has_layer("IP");
+
+    p_utl=CTRexScapyPktUtl(p1);
+    for p in p_utl.pkt_iter():
+        print p.name,":"
+
+    print p_utl.get_pkt_layers();
+
+    print p_utl.layer_offset("IP")
+    #print p_utl.layer_offset("IP",2)
+    t=p_utl.get_field_offet("IP",0,"src")
+    print t
+    t=p_utl.get_field_offet("IP",0,"dst")
+    print t
+    t=p_utl.get_field_offet_by_str("IP:0.src")
+    print t
+
+    t=p_utl.get_field_offet_by_str("IP.src")
+    print t
+
+
+
+
+
+
+    #p1.dump_layers_offset()
+    #p1.show2();
+    #hexdump(p1);
+
+    #wrpcap("ipv4.pcap", p1);
+
+
+def test5 ():
+    # build packet
+    pass;
+
+
+def test4 ():
+    print "test4"
+    a = CScapyTRexPktBuilder()
+    a.add_command ( CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5",flags=CTRexScIpv4TupleGen.FLAGS_ULIMIT_FLOWS))
+    a.dump_scripts ()
+    a.compile()
+
+
+def convert_to_hex (buffer):
+    for i in buffer:
+         print hex(ord(i))
+
+
+def test3 ():
+
+    vm=CTRexVmEngine()
+    vm.add_ins(CTRexVmInsFixIpv4(12))
+    vm.add_ins(CTRexVmInsFixIpv4(15))
+    #vm.dump();
+    vm.dump_bjson ()
+    vm.dump_as_yaml ()
+
+
+
+def test2 ():
+   vm_ins= CTRexVmInsTupleGen("a",0x12000001,0x12000007,1025,1027,limit_flows=10000)
+   print vm_ins.__dict__
+
+
+
+def test1 ():
+    a  = CTRexScFieldRangeValue("ip.src","inc",12,14)
+    print a.__dict__
+    b  = CTRexScIpv4SimpleRange("ip.src","inc","16.0.0.1","16.0.0.254")
+    print b.__dict__
+    c= CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5");
+    print c.__dict__
+
+    d= CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5",flags=CTRexScIpv4TupleGen.FLAGS_ULIMIT_FLOWS);
+    print d.__dict__
+
+    e= CTRexScTrimPacketSize();
+    print e.__dict__
+
+    e1= CTRexScTrimPacketSize(min_pkt_size=120, max_pkt_size=130);
+    print e1.__dict__
+
+
+
+
+def main ():
+    test_vm1 ();
+    return 
+    test_udp ()
+    return 
+
+    test4 ();
+    return 
+
+    test3 ();
+    return 
+    test2 ();
+    return 
+    test1 ();
+    return
+    #a=CTRexScIpv4SimpleRange("16.0.0.1","16.0.0.16");
+    #s=is_valid_ipv4("16.0.0.1");
+    #s=is_valid_ipv4("\x16\x01\x01\x01");
+    #s=is_valid_ipv4(0x16000101);
+    print ipv4_str_to_num("\x10\x01\x01\x01")
+    return 
+
+    print ipv4_str_to_num (s)
+
+
+    print s
+    print type(s);
+    len(s);
+    for i in s:
+         print hex(ord(i))
+
+
+
+main();
+
+
diff --git a/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder_test.py b/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder_test.py
new file mode 100644
index 00000000..7894c336
--- /dev/null
+++ b/scripts/automation/trex_control_plane/client_utils/scapy_packet_builder_test.py
@@ -0,0 +1,837 @@
+#import packet_builder
+import random
+import string
+import struct
+import socket       
+import json
+import yaml
+import binascii
+
+
+from scapy.all import *
+
+
+
+class CTRexPacketBuildException(Exception):
+    """
+    This is the general Packet Building error exception class.
+    """
+    def __init__(self, code, message):
+        self.code = code
+        self.message = message
+
+    def __str__(self):
+        return self.__repr__()
+
+    def __repr__(self):
+        return u"[errcode:%r] %r" % (self.code, self.message)
+
+################################################################################################
+
+def ipv4_str_to_num (ipv4_buffer):
+
+    assert(type(ipv4_buffer)==str);
+    assert(len(ipv4_buffer)==4);
+    res=0;
+    shift=24
+    for i in ipv4_buffer:
+       res = res + (ord(i)<<shift);
+       shift =shift -8
+    return res
+
+
+
+def is_valid_ipv4(ip_addr):
+    """
+    return buffer in network order 
+    """
+    if  type(ip_addr)==str and len(ip_addr) == 4:
+        return ip_addr
+
+    if  type(ip_addr)==int :
+        ip_addr = socket.inet_ntoa(struct.pack("!I", ip_addr)) 
+
+    try:
+        return socket.inet_pton(socket.AF_INET, ip_addr)
+    except AttributeError:  # no inet_pton here, sorry
+        return socket.inet_aton(ip_addr)
+    except socket.error:  # not a valid address
+        raise CTRexPacketBuildException(-10,"not valid ipv4 format");
+
+
+class CTRexScriptsBase(object):
+    """
+    VM Script base class 
+    """
+    def clone (self):
+        return copy.deepcopy(self)
+
+
+class CTRexScFieldRangeBase(CTRexScriptsBase):
+
+    FILED_TYPES = ["inc","dec","rand"]  
+
+    def __init__(self, field_name,
+                       field_type
+                            ):
+        super(CTRexScFieldRangeBase, self).__init__()
+        self.field_name =field_name
+        self.field_type =field_type
+        if not self.field_type in CTRexScFieldRangeBase.FILED_TYPES :
+            raise CTRexPacketBuildException(-12,"field type should be in [inc,dec,rand] ");
+
+
+class CTRexScFieldRangeValue(CTRexScFieldRangeBase):
+    """
+    range of field value
+    """
+    def __init__(self, field_name, 
+                       field_type,
+                       min_val,
+                       max_val
+                           ):
+        super(CTRexScFieldRangeValue, self).__init__(field_name,field_type)
+        self.min_val =min_val;
+        self.max_val =max_val;
+        if min_val > max_val:
+            raise CTRexPacketBuildException(-12,"min is greater than max ");
+        if min_val == max_val:
+            raise CTRexPacketBuildException(-13,"min value is equal to max value, you can't use this type of range ");
+
+
+class CTRexScIpv4SimpleRange(CTRexScFieldRangeBase):
+    """
+    range of ipv4 ip
+    """
+    def __init__(self, field_name,field_type,min_ip, max_ip):
+        super(CTRexScIpv4SimpleRange, self).__init__(field_name,field_type)
+        self.min_ip = min_ip
+        self.max_ip = max_ip
+        mmin=ipv4_str_to_num (is_valid_ipv4(min_ip))
+        mmax=ipv4_str_to_num (is_valid_ipv4(max_ip))
+        if  mmin > mmax :
+            raise CTRexPacketBuildException(-11,"CTRexScIpv4SimpleRange m_min ip is bigger than max ");
+
+
+class CTRexScIpv4TupleGen(CTRexScriptsBase):
+    """
+    range tuple 
+    """
+    FLAGS_ULIMIT_FLOWS =1
+
+    def __init__(self, min_ipv4, max_ipv4,num_flows=100000,min_port=1025,max_port=65535,flags=0):
+        super(CTRexScIpv4TupleGen, self).__init__()
+        self.min_ip = min_ipv4
+        self.max_ip = max_ipv4
+        mmin=ipv4_str_to_num (is_valid_ipv4(min_ipv4))
+        mmax=ipv4_str_to_num (is_valid_ipv4(max_ipv4))
+        if  mmin > mmax :
+            raise CTRexPacketBuildException(-11,"CTRexScIpv4SimpleRange m_min ip is bigger than max ");
+
+        self.num_flows=num_flows;
+
+        self.min_port =min_port
+        self.max_port =max_port
+        self.flags =   flags
+
+
+class CTRexScTrimPacketSize(CTRexScriptsBase):
+    """
+    trim packet size. field type is CTRexScFieldRangeBase.FILED_TYPES = ["inc","dec","rand"]  
+    """
+    def __init__(self,field_type="rand",min_pkt_size=None, max_pkt_size=None):
+        super(CTRexScTrimPacketSize, self).__init__()
+        self.field_type = field_type
+        self.min_pkt_size = min_pkt_size
+        self.max_pkt_size = max_pkt_size
+        if max_pkt_size != None and min_pkt_size !=None :
+            if min_pkt_size == max_pkt_size:
+                raise CTRexPacketBuildException(-11,"CTRexScTrimPacketSize min_pkt_size is the same as max_pkt_size ");
+
+            if min_pkt_size > max_pkt_size:
+                raise CTRexPacketBuildException(-11,"CTRexScTrimPacketSize min_pkt_size is bigger than max_pkt_size ");
+
+class CTRexScRaw(CTRexScriptsBase):
+    """
+    raw instructions 
+    """
+    def __init__(self,list_of_commands=None):
+        super(CTRexScRaw, self).__init__()
+        if list_of_commands==None:
+            self.commands =[]
+        else:
+            self.commands = list_of_commands
+
+    def add_cmd (self,cmd):
+        self.commands.append(cmd)
+
+
+
+################################################################################################
+# VM raw instructions 
+################################################################################################
+
+class CTRexVmInsBase(object):
+    """
+    instruction base
+    """
+    def __init__(self,ins_type):
+        self.type = ins_type
+        assert(type(ins_type)==str);
+
+class CTRexVmInsFixIpv4(CTRexVmInsBase):
+    def __init__(self,offset):
+        super(CTRexVmInsFixIpv4, self).__init__("fix_checksum_ipv4")
+        self.offset = offset
+        assert(type(offset)==int);
+
+
+class CTRexVmInsFlowVar(CTRexVmInsBase):
+    #TBD add more validation tests
+
+    OPERATIONS =["inc", "dec", "random"]
+    VALID_SIZES =[1,2,4,8]
+
+    def __init__(self,fv_name,size,op,init_val,min_val,max_val):
+        super(CTRexVmInsFlowVar, self).__init__("flow_var")
+        self.name =fv_name;
+        assert(type(fv_name)==str);
+        self.size =size
+        self.op =op
+        self.init_val=init_val
+        assert(type(init_val)==int);
+        self.min_val=min_val
+        assert(type(min_val)==int);
+        self.max_val=max_val
+        assert(type(max_val)==int);
+
+class CTRexVmInsWrFlowVar(CTRexVmInsBase):
+    def __init__(self,fv_name,pkt_offset,add_val=0,is_big=True):
+        super(CTRexVmInsWrFlowVar, self).__init__("write_flow_var")
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.pkt_offset =pkt_offset
+        assert(type(pkt_offset)==int);
+        self.add_val =add_val
+        assert(type(add_val)==int);
+        self.is_big =is_big;
+        assert(type(is_big)==bool);
+
+class CTRexVmInsTrimPktSize(CTRexVmInsBase):
+    def __init__(self,fv_name):
+        super(CTRexVmInsTrimPktSize, self).__init__("trim_pkt_size")
+        self.fv_name =fv_name
+        assert(type(fv_name)==str);
+
+class CTRexVmInsTupleGen(CTRexVmInsBase):
+    def __init__(self,fv_name,ip_min,ip_max,port_min,port_max,limit_flows,flags=0):
+        super(CTRexVmInsTupleGen, self).__init__("tuple_flow_var")
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.ip_min = ip_min;
+        self.ip_max = ip_max;
+        self.port_min = port_min;
+        self.port_max = port_max;
+        self.limit_flows = limit_flows;
+        self.flags       =flags;
+
+
+################################################################################################
+# 
+class CTRexVmEngine(object):
+
+       def __init__(self):
+            """
+            inlcude list of instruction
+            """
+            super(CTRexVmEngine, self).__init__()
+            self.ins=[]
+            self.split_by_var = ''
+
+       # return as json 
+       def get_json (self):
+           inst_array = [];
+           # dump it as dict
+           for obj in self.ins:
+               inst_array.append(obj.__dict__);
+
+           return {'instructions': inst_array, 'split_by_var': self.split_by_var}
+
+       def add_ins (self,ins):
+           #assert issubclass(ins, CTRexVmInsBase)
+           self.ins.append(ins);
+
+       def dump (self):
+           cnt=0;
+           for obj in self.ins:
+               print "ins",cnt
+               cnt = cnt +1
+               print obj.__dict__
+
+       def dump_bjson (self):
+          print json.dumps(self.get_json(), sort_keys=True, indent=4)
+
+       def dump_as_yaml (self):
+          print yaml.dump(self.get_json(), default_flow_style=False)
+
+
+
+################################################################################################
+
+class CTRexScapyPktUtl(object):
+
+    def __init__(self,scapy_pkt):
+        self.pkt = scapy_pkt
+
+    def pkt_iter (self):
+        p=self.pkt;
+        while True:
+            yield p
+            p=p.payload
+            if p ==None or isinstance(p,NoPayload):
+                break;
+
+    def get_list_iter (self):
+        l=list(self.pkt_iter())
+        return l
+
+
+    def get_pkt_layers (self):
+        """
+        return string 'IP:UDP:TCP'
+        """
+        l=self.get_list_iter ();
+        l1=map(lambda p: p.name,l );
+        return ":".join(l1);
+
+    def _layer_offset(self,name,cnt=0):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        save_cnt=cnt
+        for pkt in self.pkt_iter ():
+            if pkt.name == name:
+                if cnt==0:
+                    return (pkt, pkt.offset)
+                else:
+                    cnt=cnt -1
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d" % (name,save_cnt)));
+
+
+    def layer_offset(self,name,cnt=0):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        save_cnt=cnt
+        for pkt in self.pkt_iter ():
+            if pkt.name == name:
+                if cnt==0:
+                    return pkt.offset
+                else:
+                    cnt=cnt -1
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d" % (name,save_cnt)));
+
+    def get_field_offet(self,layer,layer_cnt,field_name):
+        """
+        return offset of layer e.g 'IP',1 will return offfset of layer ip:1 
+        """
+        t=self._layer_offset(layer,layer_cnt);
+        l_offset=t[1];
+        layer_pkt=t[0]
+
+        #layer_pkt.dump_fields_offsets ()
+
+        for f in layer_pkt.fields_desc:
+            if f.name == field_name:
+                return (l_offset+f.offset,f.get_size_bytes ());
+
+        raise CTRexPacketBuildException(-11,("no layer %s-%d." % (name,save_cnt,field_name)));
+
+    def  get_layer_offet_by_str(self,layer_des):
+        """
+        return layer offset by string  
+
+        IP:0
+        IP:1
+        return offset
+
+        """
+        l1=layer_des.split(":")
+        layer=""
+        layer_cnt=0;
+
+        if len(l1)==1:
+            layer=l1[0];
+        else:
+            layer=l1[0];
+            layer_cnt=int(l1[1]);
+
+        return self.layer_offset(layer,layer_cnt)
+
+
+
+    def  get_field_offet_by_str(self,field_des):
+        """
+        return field_des (offset,size) layer:cnt.field 
+        for example 
+
+        IP.src
+        IP:0.src  (first IP.src like IP.src)
+        for example IP:1.src  for internal IP
+
+        return (offset, size) as tuple 
+
+        """
+
+        s=field_des.split(".");
+        if len(s)!=2:
+            raise CTRexPacketBuildException(-11,("field desription should be layer:cnt.field e.g IP.src or IP:1.src "));
+
+
+        layer_ex = s[0]
+        field = s[1]
+
+        l1=layer_ex.split(":")
+        layer=""
+        layer_cnt=0;
+
+        if len(l1)==1:
+            layer=l1[0];
+        else:
+            layer=l1[0];
+            layer_cnt=int(l1[1]);
+
+        return self.get_field_offet(layer,layer_cnt,field)
+
+    def has_IPv4 (self):
+        return self.pkt.has_layer("IP");
+
+    def has_IPv6 (self):
+        return self.pkt.has_layer("IPv6");
+
+    def has_UDP (self):
+        return self.pkt.has_layer("UDP");
+
+################################################################################################
+
+class CTRexVmDescBase(object):
+    """
+    instruction base
+    """
+    def __init__(self):
+       pass;
+
+    def get_obj (self):
+        return self;
+
+    def get_json (self):
+        return self.get_obj().__dict__
+
+    def dump_bjson (self):
+       print json.dumps(self.get_json(), sort_keys=True, indent=4)
+
+    def dump_as_yaml (self):
+       print yaml.dump(self.get_json(), default_flow_style=False)
+
+
+    def get_var_name(self):
+        '''
+          virtual function return the varible name if exists
+        ''' 
+        return None
+
+    def compile(self,parent): 
+        '''
+          virtual function to take parent than has function name_to_offset
+        ''' 
+        pass;
+
+
+def valid_fv_size (size):
+    if not (size in CTRexVmInsFlowVar.VALID_SIZES):
+        raise CTRexPacketBuildException(-11,("flow var has not valid size %d ") % size  );
+
+def valid_fv_ops (op):
+    if not (op in CTRexVmInsFlowVar.OPERATIONS):
+        raise CTRexPacketBuildException(-11,("flow var does not have a valid op %s ") % op  );
+
+def convert_val (val):
+    if type(val) == int:
+        return val
+    else:
+        if type(val) == str:
+          return ipv4_str_to_num (is_valid_ipv4(val))
+        else:
+            raise CTRexPacketBuildException(-11,("init val not valid %s ") % val  );
+
+
+class CTRexVmDescFlowVar(CTRexVmDescBase):
+    def __init__(self,name,init_val=0,min_val=0,max_val=255,size=4,op="inc"):
+        super(CTRexVmDescFlowVar, self).__init__()
+        self.name = name;
+        assert(type(name)==str);
+        self.size =size
+        valid_fv_size(size)
+        self.op =op
+        valid_fv_ops (op)
+        self.init_val = convert_val (init_val)
+        self.min_val  = convert_val (min_val);
+        self.max_val  = convert_val (max_val)
+
+        if self.min_val > self.max_val :
+            raise CTRexPacketBuildException(-11,("max %d is lower than min %d ") % (self.max_val,self.min_val)  );
+
+    def get_obj (self):
+        return CTRexVmInsFlowVar(self.name,self.size,self.op,self.init_val,self.min_val,self.max_val);
+
+    def get_var_name(self):
+        return self.name
+
+
+class CTRexVmDescFixIpv4(CTRexVmDescBase):
+    def __init__(self,offset):
+        super(CTRexVmDescFixIpv4, self).__init__()
+        self.offset = offset; # could be a name of offset 
+
+    def get_obj (self):
+        return CTRexVmInsFixIpv4(self.offset);
+
+    def compile(self,parent): 
+        if type(self.offset)==str:
+            self.offset = parent._pkt_layer_offset(self.offset);
+
+class CTRexVmDescWrFlowVar(CTRexVmDescBase):
+    def __init__(self,fv_name,pkt_offset,add_val=0,is_big=True):
+        super(CTRexVmDescWrFlowVar, self).__init__()
+        self.name =fv_name
+        assert(type(fv_name)==str);
+        self.pkt_offset =pkt_offset
+        self.add_val =add_val
+        assert(type(add_val)==int);
+        self.is_big =is_big;
+        assert(type(is_big)==bool);
+
+    def get_obj (self):
+            return  CTRexVmInsWrFlowVar(self.name,self.pkt_offset,self.add_val,self.is_big)
+
+    def compile(self,parent): 
+        if type(self.pkt_offset)==str:
+            t=parent._name_to_offset(self.pkt_offset)
+            self.pkt_offset = t[0]
+
+
+################################################################################################
+
+
+class CScapyTRexPktBuilder(object):
+
+    """
+    This class defines the TRex API of building a packet using dpkt package.
+    Using this class the user can also define how TRex will handle the packet by specifying the VM setting.
+    """
+    def __init__(self):
+        """
+        Instantiate a CTRexPktBuilder object
+
+        :parameters:
+             None
+
+        """
+        super(CScapyTRexPktBuilder, self).__init__()
+        self._pkt = None # scapy packet 
+        self.vm_scripts = [] # list of high level instructions
+        self.vm_low_level = None
+        self.metadata=""
+
+    def get_vm_data(self):
+        """
+        Dumps the instructions 
+
+        :parameters:
+            None
+
+        :return:
+            + json object of instructions
+
+        """
+
+        return self.vm_low_level.get_json () 
+
+    def dump_pkt(self):
+        """
+        Dumps the packet as a decimal array of bytes (each item x gets value between 0-255)
+
+        :parameters:
+            None
+
+        :return:
+            + packet representation as array of bytes
+
+        :raises:
+            + :exc:`CTRexPktBuilder.EmptyPacketError`, in case packet is empty.
+
+        """
+
+        assert(self.pkt);
+
+        pkt_in_hex = binascii.hexlify(str(self.pkt))
+        return {"binary": [int(pkt_in_hex[i:i+2], 16)
+                           for i in range(0, len(pkt_in_hex), 2)],
+                "meta": self.metadata}
+
+
+    def add_command (self,script):
+        self.vm_scripts.append(script.clone());
+
+    def dump_scripts (self):
+        self.vm_low_level.dump_as_yaml ()
+
+    def set_packet (self,pkt):
+        """
+        Scapy packet   Ether()/IP(src="16.0.0.1",dst="48.0.0.1")/UDP(dport=12,sport=1025)/IP()/"A"*10
+        """
+        self.pkt =pkt;
+
+
+    def compile (self):
+        self.vm_low_level=CTRexVmEngine()
+        assert(self.pkt);
+        self.pkt.build();
+
+        
+        for sc in self.vm_scripts:
+            if isinstance(sc, CTRexScRaw):
+                self._compile_raw (sc)
+
+        #for obj in self.vm_scripts:
+        #    # tuple gen script 
+        #    if isinstance(obj, CTRexScIpv4TupleGen)
+        #        self._add_tuple_gen(tuple_gen)
+
+    ####################################################
+    # private 
+
+    def _compile_raw (self,obj):
+
+        # make sure we have varibles once 
+        vars={};
+        for desc in obj.commands:
+            print desc.__dict__
+            var_name =  desc.get_var_name()
+            print var_name
+            if var_name :
+                if vars.has_key(var_name):
+                    raise CTRexPacketBuildException(-11,("varible %s define twice ") % (var_name)  );
+                else:
+                    vars[var_name]=1
+            desc.compile(self);
+
+        for desc in obj.commands:
+            self.vm_low_level.add_ins(desc.get_obj());
+
+
+    def _pkt_layer_offset (self,layer_name):
+        assert(self.pkt != None);
+        p_utl=CTRexScapyPktUtl(self.pkt);
+        return p_utl.get_layer_offet_by_str(layer_name)
+
+    def _name_to_offset(self,field_name):
+        assert(self.pkt != None);
+        p_utl=CTRexScapyPktUtl(self.pkt);
+        return p_utl.get_field_offet_by_str(field_name)
+
+    def  _add_tuple_gen(self,tuple_gen):
+
+        pass;
+
+
+
+################################################################################################
+# tests 
+################################################################################################
+# what should I do 
+# 1. iterator on the headers 
+# 2. do I have one IP? 
+# 3. offset of the UDP/TCP?
+# offset of each field inside the packet ? 
+
+def test_vm1 ():
+    a=CTRexVmDescFlowVar(name="a",min_val=0,max_val=255,init_val=0,size=4,op="inc");
+    a.dump_as_yaml ()
+    a.dump_bjson()
+
+    a=CTRexVmDescFlowVar(name="a",min_val="10.0.0.1",max_val="10.0.0.10",init_val="10.0.0.1",size=4,op="inc");
+    a.dump_as_yaml ()
+    a.dump_bjson()
+
+    raw = CTRexScRaw()
+    raw.add_cmd( CTRexVmDescFlowVar(name="a",min_val=0,max_val=255,init_val=0,size=4,op="inc") )
+    raw.add_cmd( CTRexVmDescFixIpv4(offset = "IP") )
+    raw.add_cmd( CTRexVmDescWrFlowVar (fv_name="a",pkt_offset= "IP.src") )
+
+
+    raw1 = CTRexScRaw( [ CTRexVmDescFlowVar(name="a",min_val="16.0.0.1",max_val="16.0.0.10",init_val="16.0.0.1",size=4,op="inc"),
+                          CTRexVmDescWrFlowVar (fv_name="a",pkt_offset= "IP.src"),
+                          CTRexVmDescFixIpv4(offset = "IP")]
+                      );
+
+    pkt_builder = CScapyTRexPktBuilder();
+
+    py='5'*128
+    pkt=Ether()/ \
+             IP(src="16.0.0.1",dst="48.0.0.1")/ \
+             UDP(dport=12,sport=1025)/IP()/py
+
+    # set packet 
+    pkt_builder.set_packet(pkt);
+    pkt_builder.add_command ( raw1 )
+    pkt_builder.compile();
+
+    pkt_builder.dump_scripts ()
+
+    print pkt_builder.dump_pkt()
+    print pkt_builder.get_vm_data()
+
+    print "hey"
+
+
+
+
+
+
+
+def test_udp ():
+    py='5'*128
+    p1=Ether()/ \
+             IP(src="16.0.0.1",dst="48.0.0.1")/ \
+             UDP(dport=12,sport=1025)/IP()/py
+
+    p1.build();
+    #print p1.haslayer("UDP.tos:1");
+
+    #pkt_utl=CTRexScapyPktUtl(p1);
+    #pkt_utl.has_layer("IP");
+
+    p_utl=CTRexScapyPktUtl(p1);
+    for p in p_utl.pkt_iter():
+        print p.name,":"
+
+    print p_utl.get_pkt_layers();
+
+    print p_utl.layer_offset("IP")
+    #print p_utl.layer_offset("IP",2)
+    t=p_utl.get_field_offet("IP",0,"src")
+    print t
+    t=p_utl.get_field_offet("IP",0,"dst")
+    print t
+    t=p_utl.get_field_offet_by_str("IP:0.src")
+    print t
+
+    t=p_utl.get_field_offet_by_str("IP.src")
+    print t
+
+
+
+
+
+
+    #p1.dump_layers_offset()
+    #p1.show2();
+    #hexdump(p1);
+
+    #wrpcap("ipv4.pcap", p1);
+
+
+def test5 ():
+    # build packet
+    pass;
+
+
+def test4 ():
+    print "test4"
+    a = CScapyTRexPktBuilder()
+    a.add_command ( CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5",flags=CTRexScIpv4TupleGen.FLAGS_ULIMIT_FLOWS))
+    a.dump_scripts ()
+    a.compile()
+
+
+def convert_to_hex (buffer):
+    for i in buffer:
+         print hex(ord(i))
+
+
+def test3 ():
+
+    vm=CTRexVmEngine()
+    vm.add_ins(CTRexVmInsFixIpv4(12))
+    vm.add_ins(CTRexVmInsFixIpv4(15))
+    #vm.dump();
+    vm.dump_bjson ()
+    vm.dump_as_yaml ()
+
+
+
+def test2 ():
+   vm_ins= CTRexVmInsTupleGen("a",0x12000001,0x12000007,1025,1027,limit_flows=10000)
+   print vm_ins.__dict__
+
+
+
+def test1 ():
+    a  = CTRexScFieldRangeValue("ip.src","inc",12,14)
+    print a.__dict__
+    b  = CTRexScIpv4SimpleRange("ip.src","inc","16.0.0.1","16.0.0.254")
+    print b.__dict__
+    c= CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5");
+    print c.__dict__
+
+    d= CTRexScIpv4TupleGen("16.0.0.1","16.0.0.5",flags=CTRexScIpv4TupleGen.FLAGS_ULIMIT_FLOWS);
+    print d.__dict__
+
+    e= CTRexScTrimPacketSize();
+    print e.__dict__
+
+    e1= CTRexScTrimPacketSize(min_pkt_size=120, max_pkt_size=130);
+    print e1.__dict__
+
+
+
+
+def main ():
+    test_vm1 ();
+    return 
+    test_udp ()
+    return 
+
+    test4 ();
+    return 
+
+    test3 ();
+    return 
+    test2 ();
+    return 
+    test1 ();
+    return
+    #a=CTRexScIpv4SimpleRange("16.0.0.1","16.0.0.16");
+    #s=is_valid_ipv4("16.0.0.1");
+    #s=is_valid_ipv4("\x16\x01\x01\x01");
+    #s=is_valid_ipv4(0x16000101);
+    print ipv4_str_to_num("\x10\x01\x01\x01")
+    return 
+
+    print ipv4_str_to_num (s)
+
+
+    print s
+    print type(s);
+    len(s);
+    for i in s:
+         print hex(ord(i))
+
+
+
+main();
+
+