Add initial PTP support with header and message types

- Implement PTP header structure based on IEEE 1588-2008
- Implement Sync message type class

Author: satveerbrar

scapy/layers/ptp_v2.py

@@ -0,0 +1,214 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# This file is part of Scapy
+# See https://scapy.net/ for more information
+# Copyright (C) Philippe Biondi <phil@secdev.org>
+# Copyright (C) Satveer Brar
+
+"""
+PTP (Precision Time Protocol).
+References : IEEE 1588-2008
+"""
+
+from scapy.packet import Packet, bind_layers
+from scapy.fields import (
+    BitEnumField,
+    BitField,
+    ByteField,
+    IntField,
+    LongField,
+    ShortField,
+    ByteEnumField,
+    FlagsField,
+    PacketField,
+    XLongField,
+)
+from scapy.layers.inet import UDP
+
+
+#############################################################################
+#     PTPv2
+#############################################################################
+
+# IEEE 1588-2008 / Section 13.3.2.2
+
+_message_type = {
+    0x0: "Sync",
+    0x1: "Delay_Req",
+    0x2: "Pdelay_Req",
+    0x3: "Pdelay_Resp",
+    0x4: "Reserved",
+    0x5: "Reserved",
+    0x6: "Reserved",
+    0x7: "Reserved",
+    0x8: "Follow_Up",
+    0x9: "Delay_Resp",
+    0xA: "Pdelay_Resp_Follow",
+    0xB: "Announce",
+    0xC: "Signaling",
+    0xD: "Management",
+    0xE: "Reserved",
+    0xF: "Reserved"
+}
+
+_control_field = {
+    0x00: "Sync",
+    0x01: "Delay_Req",
+    0x02: "Follow_Up",
+    0x03: "Delay_Resp",
+    0x04: "Management",
+    0x05: "All others",
+}
+
+_flags = {
+    0x0001: "alternateMasterFlag",
+    0x0002: "twoStepFlag",
+    0x0004: "unicastFlag",
+    0x0010: "ptpProfileSpecific1",
+    0x0020: "ptpProfileSpecific2",
+    0x0040: "reserved",
+    0x0100: "leap61",
+    0x0200: "leap59",
+    0x0400: "currentUtcOffsetValid",
+    0x0800: "ptpTimescale",
+    0x1000: "timeTraceable",
+    0x2000: "frequencyTraceable"
+}
+
+
+class OriginTimestamp(Packet):
+    name = "originTimestamp"
+    fields_desc = [
+        BitField("seconds", 0, 48),
+        IntField("nanoseconds", 0)
+    ]
+
+
+class PTPHeader(Packet):
+    """
+    PTP Header based on IEEE 1588-2008 / Section 13.3.
+    """
+    name = "PTPHeader"
+    match_subclass = True
+    fields_desc = [
+        BitField("transportSpecific", 0, 4),
+        BitEnumField("messageType", 0x0, 4, _message_type),
+        BitField("reserved1", 0, 4),
+        BitField("version", 2, 4),
+        ShortField("messageLength", 0),
+        ByteField("domainNumber", 0),
+        ByteField("reserved2", 0),
+        FlagsField("flags", 0, 16, _flags),
+        LongField("correctionField", 0),
+        IntField("reserved3", 0),
+        XLongField("clockIdentity", 0),
+        ShortField("portNumber", 0),
+        ShortField("sequenceId", 0),
+        ByteEnumField("controlField", 0, _control_field),
+        ByteField("logMessageInterval", 0)
+    ]
+
+    def guess_payload_class(self, payload):  # type: (bytes) -> Type[Packet]
+        """
+        Guess payload class based on messageType
+        """
+
+        if self.messageType == 0x0:
+            return Sync
+        elif self.messageType == 0x1:
+            return DelayReq
+        elif self.messageType == 0x2:
+            return PDelayReq
+        elif self.messageType == 0x3:
+            return PDelayResp
+        elif self.messageType == 0x8:
+            return FollowUp
+        elif self.messageType == 0x9:
+            return DelayResp
+        elif self.messageType == 0xA:
+            return PDelayRespFollow
+        elif self.messageType == 0xB:
+            return Announce
+        elif self.messageType == 0xC:
+            return Signaling
+        elif self.messageType == 0xD:
+            return Management
+
+        return Packet.guess_payload_class(self, payload)
+
+    def post_build(self, pkt, pay):  # type: (bytes, bytes) -> bytes
+        """
+        Update the messageLength field after building the packet
+        """
+        pass
+
+
+class Sync(Packet):
+    """
+    Handle the Sync message type in PTP
+    """
+    name = "Sync"
+    fields_desc = [
+        PacketField("originTimestamp", 0, OriginTimestamp)
+    ]
+
+
+class DelayReq(Packet):
+    """
+    Handle the DelayReq message type in PTP
+    """
+
+
+class PDelayReq(Packet):
+    """
+    Handle the PDelayReq message type in PTP
+    """
+
+
+class FollowUp(Packet):
+    """
+    Handle the FollowUp message type in PTP
+    """
+
+
+class PDelayResp(Packet):
+    """
+    Handle the PDelayResp message type in PTP
+    """
+
+
+class DelayResp(Packet):
+    """
+    Handle the DelayResp message type in PTP
+    """
+
+
+class PDelayRespFollow(Packet):
+    """
+    Handle the PDelayRespFollow message type in PTP
+    """
+
+
+class Announce(Packet):
+    """
+    Handle the Announce message type in PTP
+    """
+
+
+class Signaling(Packet):
+    """
+    Handle the Signaling message type in PTP
+    """
+
+
+class Management(Packet):
+    """
+    Handle the Management message type in PTP
+    """
+
+
+##############################################################################
+#     Layer bindings
+##############################################################################
+
+bind_layers(UDP, PTPHeader, sport=319, dport=319)
+bind_layers(UDP, PTPHeader, sport=320, dport=320)