diff options
Diffstat (limited to 'scripts/automation/trex_control_plane/client_utils/packet_builder.py')
| -rw-r--r-- | scripts/automation/trex_control_plane/client_utils/packet_builder.py | 720 |
1 files changed, 720 insertions, 0 deletions
diff --git a/scripts/automation/trex_control_plane/client_utils/packet_builder.py b/scripts/automation/trex_control_plane/client_utils/packet_builder.py new file mode 100644 index 00000000..fc34d931 --- /dev/null +++ b/scripts/automation/trex_control_plane/client_utils/packet_builder.py @@ -0,0 +1,720 @@ +#!/router/bin/python + + +import outer_packages +import dpkt +import socket +import binascii +import copy +import random +import string +import struct +import re + + +class CTRexPktBuilder(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, max_pkt_size=dpkt.ethernet.ETH_LEN_MAX): + """ + Instantiate a CTRexPktBuilder object + + :parameters: + None + + """ + super(CTRexPktBuilder, self).__init__() + self._packet = None + self._pkt_by_hdr = {} + self._pkt_top_layer = None + self._max_pkt_size = max_pkt_size + self.payload_generator = CTRexPktBuilder.CTRexPayloadGen(self._packet, self._max_pkt_size) + self.vm = CTRexPktBuilder.CTRexVM() + + def add_pkt_layer(self, layer_name, pkt_layer): + """ + This method adds additional header to the already existing packet + + :parameters: + layer_name: str + a string representing the name of the layer. + Example: "l2", "l4_tcp", etc. + + pkt_layer : dpkt.Packet obj + a dpkt object, generally from higher layer, that will be added on top of existing layer. + + :raises: + + :exc:`ValueError`, in case the desired layer_name already exists. + + """ + assert isinstance(pkt_layer, dpkt.Packet) + if layer_name in self._pkt_by_hdr: + raise ValueError("Given layer name '{0}' already exists.".format(layer_name)) + else: + dup_pkt = copy.copy(pkt_layer) # using copy of layer to avoid cyclic packets that may lead to infinite loop + if not self._pkt_top_layer: # this is the first header added + self._packet = dup_pkt + else: + self._pkt_top_layer.data = dup_pkt + self._pkt_top_layer = dup_pkt + self._pkt_by_hdr[layer_name] = dup_pkt + return + + def set_ip_layer_addr(self, layer_name, attr, ip_addr, ip_type="ipv4"): + try: + layer = self._pkt_by_hdr[layer_name.lower()] + if not (isinstance(layer, dpkt.ip.IP) or isinstance(layer, dpkt.ip6.IP6)): + raise ValueError("The specified layer '{0}' is not of IPv4/IPv6 type.".format(layer_name)) + else: + decoded_ip = CTRexPktBuilder._decode_ip_addr(ip_addr, ip_type) + setattr(layer, attr, decoded_ip) + except KeyError: + raise KeyError("Specified layer '{0}' doesn't exist on packet.".format(layer_name)) + + def set_ipv6_layer_addr(self, layer_name, attr, ip_addr): + self.set_ip_layer_addr(layer_name, attr, ip_addr, ip_type="ipv6") + + def set_eth_layer_addr(self, layer_name, attr, mac_addr): + try: + layer = self._pkt_by_hdr[layer_name.lower()] + if not isinstance(layer, dpkt.ethernet.Ethernet): + raise ValueError("The specified layer '{0}' is not of Ethernet type.".format(layer_name)) + else: + decoded_mac = CTRexPktBuilder._decode_mac_addr(mac_addr) + setattr(layer, attr, decoded_mac) + except KeyError: + raise KeyError("Specified layer '{0}' doesn't exist on packet.".format(layer_name)) + + def set_layer_attr(self, layer_name, attr, val, toggle_bit=False): + """ + This method enables the user to change a value of a previously defined packet layer. + This method isn't to be used to set the data attribute of a packet with payload. + Use :func:`packet_builder.CTRexPktBuilder.set_payload` instead. + + :parameters: + layer_name: str + a string representing the name of the layer. + Example: "l2", "l4_tcp", etc. + + attr : str + a string representing the attribute to be changed on desired layer + + val : + value of attribute. + + toggle_bit : bool + Indicating if trying to set a specific bit of a field, such as "do not fragment" bit of IP layer. + + Default: **False** + + :raises: + + :exc:`KeyError`, in case of missing layer (the desired layer isn't part of packet) + + :exc:`ValueError`, in case invalid attribute to the specified layer. + + """ + try: + layer = self._pkt_by_hdr[layer_name.lower()] + if attr == 'data' and not isinstance(val, dpkt.Packet): + # Don't allow setting 'data' attribute + raise ValueError("Set a data attribute with object that is not dpkt.Packet is not allowed using " + "set_layer_attr method.\nUse set_payload method instead.") + if hasattr(layer, attr): + if toggle_bit: + setattr(layer, attr, val | getattr(layer, attr, 0)) + else: + setattr(layer, attr, val) + if attr == 'data': + # re-evaluate packet from the start, possible broken link between layers + self._reevaluate_packet(layer_name.lower()) + else: + raise ValueError("Given attr name '{0}' doesn't exists on specified layer ({1}).".format(layer_name, + attr)) + except KeyError: + raise KeyError("Specified layer '{0}' doesn't exist on packet.".format(layer_name)) + + def set_layer_bit_attr(self, layer_name, attr, val): + return self.set_layer_attr(layer_name, attr, val, True) + + def set_pkt_payload(self, payload): + """ + This method sets a payload to the topmost layer of the generated packet. + This method isn't to be used to set another networking layer to the packet. + Use :func:`packet_builder.CTRexPktBuilder.set_layer_attr` instead. + + + :parameters: + payload: + a payload to be added to the packet at the topmost layer. + this object cannot be of type dpkt.Packet. + + :raises: + + :exc:`AttributeError`, in case no underlying header to host the payload. + + """ + assert isinstance(payload, str) + try: + self._pkt_top_layer.data = payload + except AttributeError: + raise AttributeError("The so far built packet doesn't contain an option for payload attachment.\n" + "Make sure to set appropriate underlying header before adding payload") + + def load_packet(self, packet): + """ + This method enables the user to change a value of a previously defined packet layer. + + :parameters: + packet: dpkt.Packet obj + a dpkt object that represents a packet. + + + :raises: + + :exc:`CTRexPktBuilder.IPAddressError`, in case invalid ip type option specified. + + """ + assert isinstance(packet, dpkt.Packet) + self._packet = copy.copy(packet) + + self._pkt_by_hdr.clear() + self._pkt_top_layer = self._packet + # analyze packet to layers + tmp_layer = self._packet + while True: + if isinstance(tmp_layer, dpkt.Packet): + layer_name = self._gen_layer_name(type(tmp_layer).__name__) + self._pkt_by_hdr[layer_name] = tmp_layer + self._pkt_top_layer = tmp_layer + try: + # check existence of upper layer + tmp_layer = tmp_layer.data + except AttributeError: + # this is the most upper header + self._pkt_by_hdr['pkt_final_payload'] = tmp_layer.data + break + else: + self._pkt_by_hdr['pkt_final_payload'] = tmp_layer + break + return + + def get_packet(self, get_ptr=False): + """ + This method provides access to the built packet, as an instance or as a pointer to packet itself. + + :parameters: + get_ptr : bool + indicate whether to get a reference to packet or a copy. + Use only in advanced modes + if set to true, metadata for packet is cleared, and any further modification is not guaranteed. + + default value : False + + :return: + + the current packet built by CTRexPktBuilder object. + + None if packet is empty + + """ + if get_ptr: + self._pkt_by_hdr = {} + self._pkt_top_layer = None + return self._packet + else: + return copy.copy(self._packet) + + def get_layer(self, layer_name): + """ + This method provides access to a specific layer of the packet, as a **copy of the layer instance**. + + :parameters: + layer_name : str + the name given to desired layer + + :return: + + a copy of the desired layer of the current packet if exists. + + None if no such layer + + """ + layer = self._pkt_by_hdr.get(layer_name) + return copy.copy(layer) if layer else None + + # VM access methods + def set_vm_ip_range(self, ip_start, ip_end, ip_type="ipv4"): + pass + + def set_vm_range_type(self, ip_type): + pass + + def set_vm_core_mask(self, ip_type): + pass + + def get_vm_data(self): + pass + + 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. + + """ + if self._packet is None: + raise CTRexPktBuilder.EmptyPacketError() + pkt_in_hex = binascii.hexlify(str(self._packet)) + return [int(pkt_in_hex[i:i+2], 16) + for i in range(0, len(pkt_in_hex), 2)] + # return [pkt_in_hex[i:i+2] for i in range(0, len(pkt_in_hex), 2)] + + def dump_pkt_to_pcap(self, file_path, ts=None): + """ + Dumps the packet as a decimal array of bytes (each item x gets value between 0-255) + + :parameters: + file_path : str + a path (including filename) to which to write to pcap file to. + + ts : int + a timestamp to attach to the packet when dumped to pcap file. + if ts in None, then time.time() is used to set the timestamp. + + Default: **None** + + :return: + None + + :raises: + + :exc:`CTRexPktBuilder.EmptyPacketError`, in case packet is empty. + + """ + if self._packet is None: + raise CTRexPktBuilder.EmptyPacketError() + try: + with open(file_path, 'wb') as f: + pcap_wr = dpkt.pcap.Writer(f) + pcap_wr.writepkt(self._packet, ts) + return + except IOError: + raise IOError(2, "The provided path could not be accessed") + + + # ----- useful shortcut methods ----- # + def gen_dns_packet(self): + pass + + # ----- internal methods ----- # + def _reevaluate_packet(self, layer_name): + cur_layer = self._packet + known_layers = set(self._pkt_by_hdr.keys()) + found_layers = set() + while True: + pointing_layer_name = self._find_pointing_layer(known_layers, cur_layer) + found_layers.add(pointing_layer_name) + if self._pkt_by_hdr[layer_name] is cur_layer: + self._pkt_top_layer = cur_layer + disconnected_layers = known_layers.difference(found_layers) + # remove disconnected layers + for layer in disconnected_layers: + self._pkt_by_hdr.pop(layer) + break + else: + cur_layer = cur_layer.data + + def _gen_layer_name(self, layer_class_name): + assert isinstance(layer_class_name, str) + layer_name = layer_class_name.lower() + idx = 1 + while True: + tmp_name = "{name}_{id}".format(name=layer_name, id=idx) + if tmp_name not in self._pkt_by_hdr: + return tmp_name + else: + idx += 1 + + def _find_pointing_layer(self, known_layers, layer_obj): + assert isinstance(known_layers, set) + for layer in known_layers: + if self._pkt_by_hdr[layer] is layer_obj: + return layer + + @staticmethod + def _decode_mac_addr(mac_addr): + """ + Static method to test for MAC address validity. + + :parameters: + mac_addr : str + a string representing an MAC address, separated by ':' or '-'. + + examples: '00:de:34:ef:2e:f4', '00-de-34-ef-2e-f4 + + :return: + + an hex-string representation of the MAC address. + for example, ip 00:de:34:ef:2e:f4 will return '\x00\xdeU\xef.\xf4' + + :raises: + + :exc:`CTRexPktBuilder.MACAddressError`, in case invalid ip type option specified. + + """ + tmp_mac = mac_addr.lower().replace('-', ':') + if re.match("[0-9a-f]{2}([-:])[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$", tmp_mac): + return binascii.unhexlify(tmp_mac.replace(':', '')) + # another option for both Python 2 and 3: + # codecs.decode(tmp_mac.replace(':', ''), 'hex') + else: + raise CTRexPktBuilder.MACAddressError() + + @staticmethod + def _decode_ip_addr(ip_addr, ip_type): + """ + Static method to test for IPv4/IPv6 address validity. + + :parameters: + ip_addr : str + a string representing an IP address (IPv4/IPv6) + + ip_type : str + The type of IP to be checked. + Valid types: "ipv4", "ipv6". + + :return: + + an hex-string representation of the ip address. + for example, ip 1.2.3.4 will return '\x01\x02\x03\x04' + + :raises: + + :exc:`CTRexPktBuilder.IPAddressError`, in case invalid ip type option specified. + + """ + if ip_type == "ipv4": + try: + return socket.inet_pton(socket.AF_INET, ip_addr) + except AttributeError: # no inet_pton here, sorry + # try: + return socket.inet_aton(ip_addr) + # except socket.error: + # return False + # return ip_addr.count('.') == 3 + except socket.error: # not a valid address + raise CTRexPktBuilder.IPAddressError() + elif ip_type == "ipv6": + try: + return socket.inet_pton(socket.AF_INET6, ip_addr) + except socket.error: # not a valid address + raise CTRexPktBuilder.IPAddressError() + else: + raise CTRexPktBuilder.IPAddressError() + + # ------ private classes ------ # + class CTRexPayloadGen(object): + + def __init__(self, packet_ref, max_pkt_size): + self._pkt_ref = packet_ref + self._max_pkt_size = max_pkt_size + + def gen_random_str(self): + gen_length = self._calc_gen_length() + # return a string of size gen_length bytes, to pad the packet to its max_size + return ''.join(random.SystemRandom().choice(string.ascii_letters + string.digits) + for _ in range(gen_length)) + + def gen_repeat_ptrn(self, ptrn_to_repeat): + gen_length = self._calc_gen_length() + if isinstance(ptrn_to_repeat, str): + # generate repeated string + return (ptrn_to_repeat * (gen_length/len(ptrn_to_repeat) + 1))[:gen_length] + elif isinstance(ptrn_to_repeat, int): + ptrn = binascii.unhexlify(hex(ptrn_to_repeat)[2:]) + return (ptrn * (gen_length/len(ptrn) + 1))[:gen_length] + elif isinstance(ptrn_to_repeat, tuple): + if not all((isinstance(x, int) and (x < 255) and (x >= 0)) + for x in ptrn_to_repeat): + raise ValueError("All numbers in tuple must be in range 0 <= number <= 255 ") + # generate repeated sequence + to_pack = (ptrn_to_repeat * (gen_length/len(ptrn_to_repeat) + 1))[:gen_length] + return struct.pack('B'*gen_length, *to_pack) + else: + raise ValueError("Given ptrn_to_repeat argument type ({0}) is illegal.". + format(type(ptrn_to_repeat))) + + def _calc_gen_length(self): + return self._max_pkt_size - len(self._pkt_ref) + + class CTRexVM(object): + """ + This class defines the TRex VM which represents how TRex will regenerate packets. + The packets will be regenerated based on the built packet containing this class. + """ + def __init__(self): + """ + Instantiate a CTRexVM object + + :parameters: + None + """ + super(CTRexPktBuilder.CTRexVM, self).__init__() + self.vm_variables = {} + + def set_vm_var_field(self, var_name, field_name, val): + """ + Set VM variable field. Only existing variables are allowed to be changed. + + :parameters: + var_name : str + a string representing the name of the VM variable to be changed. + field_name : str + a string representing the field name of the VM variable to be changed. + val : + a value to be applied to field_name field of the var_name VM variable. + + :raises: + + :exc:`KeyError`, in case invalid var_name has been specified. + + :exc:`CTRexPktBuilder.VMVarFieldTypeError`, in case mismatch between `val` and allowed type. + + :exc:`CTRexPktBuilder.VMVarValueError`, in case val isn't one of allowed options of field_name. + + """ + return self.vm_variables[var_name].set_field(field_name, val) + + def add_flow_man_simple(self, name, **kwargs): + """ + Adds a new flow manipulation object to the VM instance. + + :parameters: + name : str + name of the manipulation, must be distinct. + Example: 'source_ip_change' + + **kwargs : dict + optional, set flow_man fields on initialization (key = field_name, val = field_val). + Must be used with legit fields, see :func:`CTRexPktBuilder.CTRexVM.CTRexVMVariable.set_field`. + + :return: + None + + :raises: + + :exc:`CTRexPktBuilder.VMVarNameExistsError`, in case of desired flow_man name already taken. + + Exceptions from :func:`CTRexPktBuilder.CTRexVM.CTRexVMVariable.set_field` method. + Will rise when VM variables were misconfiguration. + """ + if name not in self.vm_variables.keys(): + self.vm_variables[name] = self.CTRexVMVariable(name) + # try configuring VM var attributes + for (field, value) in kwargs.items(): + self.vm_variables[name].set_field(field, value) + else: + raise CTRexPktBuilder.VMVarNameExistsError(name) + + def load_flow_man(self, flow_obj): + """ + Loads an outer VM variable (instruction) into current VM. + The outer VM variable must contain different name than existing VM variables currently registered on VM. + + :parameters: + flow_obj : CTRexVMVariable + a CTRexVMVariable to be loaded into VM variable sets. + + :return: + list holds variables data of VM + + """ + assert isinstance(flow_obj, CTRexPktBuilder.CTRexVM.CTRexVMVariable) + if flow_obj.name not in self.vm_variables.keys(): + self.vm_variables[flow_obj.name] = flow_obj + else: + raise CTRexPktBuilder.VMVarNameExistsError(flow_obj.name) + + def dump(self): + """ + dumps a VM variables (instructions) into an list data structure. + + :parameters: + None + + :return: + list holds variables data of VM + + """ + return [var.dump() + for key, var in self.vm_variables.items()] + + class CTRexVMVariable(object): + """ + This class defines a single VM variable to be used as part of CTRexVar object. + """ + VALID_SIZE = [1, 2, 4, 8] + VALID_OPERATION = ["inc", "dec", "random"] + + def __init__(self, name): + """ + Instantiate a CTRexVMVariable object + + :parameters: + name : str + a string representing the name of the VM variable. + """ + super(CTRexPktBuilder.CTRexVM.CTRexVMVariable, self).__init__() + self.name = name + self.size = 4 + self.big_endian = True + self.operation = "inc" + self.split_by_core = False + self.init_value = 1 + self.min_value = self.init_value + self.max_value = self.init_value + + def set_field(self, field_name, val): + """ + Set VM variable field. Only existing variables are allowed to be changed. + + :parameters: + field_name : str + a string representing the field name of the VM variable to be changed. + val : + a value to be applied to field_name field of the var_name VM variable. + + :return: + None + + :raises: + + :exc:`CTRexPktBuilder.VMVarNameError`, in case of illegal field name. + + :exc:`CTRexPktBuilder.VMVarFieldTypeError`, in case mismatch between `val` and allowed type. + + :exc:`CTRexPktBuilder.VMVarValueError`, in case val isn't one of allowed options of field_name. + + """ + if not hasattr(self, field_name): + raise CTRexPktBuilder.VMVarNameError(field_name) + elif field_name == "size": + if type(val) != int: + raise CTRexPktBuilder.VMVarFieldTypeError("size", int) + elif val not in self.VALID_SIZE: + raise CTRexPktBuilder.VMVarValueError("size", self.VALID_SIZE) + elif field_name == "init_value": + if type(val) != int: + raise CTRexPktBuilder.VMVarFieldTypeError("init_value", int) + elif field_name == "operation": + if type(val) != str: + raise CTRexPktBuilder.VMVarFieldTypeError("operation", str) + elif val not in self.VALID_OPERATION: + raise CTRexPktBuilder.VMVarValueError("operation", self.VALID_OPERATION) + elif field_name == "split_by_core": + val = bool(val) + # update field value on success + setattr(self, field_name, val) + + def is_valid(self): + if self.size not in self.VALID_SIZE: + return False + if self.type not in self.VALID_OPERATION: + return False + return True + + def dump(self): + """ + dumps a variable fields in a dictionary data structure. + + :parameters: + None + + :return: + dictionary holds variable data of VM variable + + """ + return {"ins_name": "flow_man_simple", # VM variable dump always refers to manipulate instruction. + "flow_variable_name": self.name, + "object_size": self.size, + # "big_endian": self.big_endian, + "Operation": self.operation, + "split_by_core": self.split_by_core, + "init_value": self.init_value, + "min_value": self.min_value, + "max_value": self.max_value} + + class CPacketBuildException(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) + + class EmptyPacketError(CPacketBuildException): + """ + This exception is used to indicate an error caused by operation performed on an empty packet. + """ + def __init__(self, message=''): + self._default_message = 'Illegal operation on empty packet.' + self.message = message or self._default_message + super(CTRexPktBuilder.EmptyPacketError, self).__init__(-10, self.message) + + class IPAddressError(CPacketBuildException): + """ + This exception is used to indicate an error on the IP addressing part of the packet. + """ + def __init__(self, message=''): + self._default_message = 'Illegal type or value of IP address has been provided.' + self.message = message or self._default_message + super(CTRexPktBuilder.IPAddressError, self).__init__(-11, self.message) + + class MACAddressError(CPacketBuildException): + """ + This exception is used to indicate an error on the MAC addressing part of the packet. + """ + def __init__(self, message=''): + self._default_message = 'Illegal MAC address has been provided.' + self.message = message or self._default_message + super(CTRexPktBuilder.MACAddressError, self).__init__(-11, self.message) + + class VMVarNameExistsError(CPacketBuildException): + """ + This exception is used to indicate a duplicate usage of VM variable. + """ + def __init__(self, name, message=''): + self._default_message = 'The given VM name ({0}) already exists as part of the stream.'.format(name) + self.message = message or self._default_message + super(CTRexPktBuilder.VMVarNameExistsError, self).__init__(-21, self.message) + + class VMVarNameError(CPacketBuildException): + """ + This exception is used to indicate that an undefined VM var field name has been accessed. + """ + def __init__(self, name, message=''): + self._default_message = "The given VM field name ({0}) is not defined and isn't legal.".format(name) + self.message = message or self._default_message + super(CTRexPktBuilder.VMVarNameError, self).__init__(-22, self.message) + + class VMVarFieldTypeError(CPacketBuildException): + """ + This exception is used to indicate an illegal value has type has been given to VM variable field. + """ + def __init__(self, name, ok_type, message=''): + self._default_message = 'The desired value of field {field_name} is of type {field_type}, \ + and not of the allowed {allowed_type}.'.format(field_name=name, + field_type=type(name).__name__, + allowed_type=ok_type.__name__) + self.message = message or self._default_message + super(CTRexPktBuilder.VMVarFieldTypeError, self).__init__(-31, self.message) + + class VMVarValueError(CPacketBuildException): + """ + This exception is used to indicate an error an illegal value has been assigned to VM variable field. + """ + def __init__(self, name, ok_opts, message=''): + self._default_message = 'The desired value of field {field_name} is illegal.\n \ + The only allowed options are: {allowed_opts}.'.format(field_name=name, + allowed_opts=ok_opts) + self.message = message or self._default_message + super(CTRexPktBuilder.VMVarValueError, self).__init__(-32, self.message) + + +if __name__ == "__main__": + pass |