Initial commit.

Change-Id: If7c53df6650cbde9ce6a5be9d581a6395ece5ca9
diff --git a/omci_frame.py b/omci_frame.py
new file mode 100644
index 0000000..edff530
--- /dev/null
+++ b/omci_frame.py
@@ -0,0 +1,124 @@
+#
+# Copyright 2017 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+from scapy.fields import ByteField, PacketField, IntField
+from scapy.fields import ShortField, ConditionalField
+from scapy.packet import Packet
+
+from voltha.extensions.omci.omci_defs import FixedLenField
+from voltha.extensions.omci.omci_messages import OmciCreate, OmciDelete, \
+    OmciDeleteResponse, OmciSet, OmciSetResponse, OmciGet, OmciGetResponse, \
+    OmciGetAllAlarms, OmciGetAllAlarmsResponse, OmciGetAllAlarmsNext, \
+    OmciMibResetResponse, OmciMibReset, OmciMibUploadNextResponse, \
+    OmciMibUploadNext, OmciMibUploadResponse, OmciMibUpload, \
+    OmciGetAllAlarmsNextResponse
+from voltha.extensions.omci.omci_messages import OmciCreateResponse
+
+
+class OmciFrame(Packet):
+    name = "OmciFrame"
+    fields_desc = [
+        ShortField("transaction_id", 0),
+        ByteField("message_type", None),
+        ByteField("omci", 0x0a),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciCreate), align=36),
+            lambda pkt: pkt.message_type == OmciCreate.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciCreateResponse), align=36),
+            lambda pkt: pkt.message_type == OmciCreateResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciDelete), align=36),
+            lambda pkt: pkt.message_type == OmciDelete.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciDeleteResponse), align=36),
+            lambda pkt: pkt.message_type == OmciDeleteResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciSet), align=36),
+            lambda pkt: pkt.message_type == OmciSet.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciSetResponse), align=36),
+            lambda pkt: pkt.message_type == OmciSetResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciGet), align=36),
+            lambda pkt: pkt.message_type == OmciGet.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciGetResponse), align=36),
+            lambda pkt: pkt.message_type == OmciGetResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciGetAllAlarms), align=36),
+            lambda pkt: pkt.message_type == OmciGetAllAlarms.message_id),
+        ConditionalField(FixedLenField(
+            PacketField(
+                "omci_message", None, OmciGetAllAlarmsResponse), align=36),
+                lambda pkt:
+                pkt.message_type == OmciGetAllAlarmsResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciGetAllAlarmsNext), align=36),
+            lambda pkt: pkt.message_type == OmciGetAllAlarmsNext.message_id),
+        ConditionalField(FixedLenField(
+            PacketField(
+                "omci_message", None, OmciGetAllAlarmsNextResponse), align=36),
+                lambda pkt:
+                pkt.message_type == OmciGetAllAlarmsNextResponse.message_id),
+
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibUpload), align=36),
+            lambda pkt: pkt.message_type == OmciMibUpload.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibUploadResponse), align=36),
+            lambda pkt: pkt.message_type == OmciMibUploadResponse.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibUploadNext), align=36),
+            lambda pkt:
+                pkt.message_type == OmciMibUploadNext.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibUploadNextResponse), align=36),
+            lambda pkt: pkt.message_type == OmciMibUploadNextResponse.message_id),
+
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibReset), align=36),
+            lambda pkt: pkt.message_type == OmciMibReset.message_id),
+        ConditionalField(FixedLenField(
+            PacketField("omci_message", None, OmciMibResetResponse), align=36),
+            lambda pkt: pkt.message_type == OmciMibResetResponse.message_id),
+
+        # TODO add entries for remaining OMCI message types
+
+        IntField("omci_trailer", 0x00000028)
+    ]
+
+    # We needed to patch the do_dissect(...) method of Packet, because
+    # it wiped out already dissected conditional fields with None if they
+    # referred to the same field name. We marked the only new line of code
+    # with "Extra condition added".
+    def do_dissect(self, s):
+        raw = s
+        self.raw_packet_cache_fields = {}
+        for f in self.fields_desc:
+            if not s:
+                break
+            s, fval = f.getfield(self, s)
+            # We need to track fields with mutable values to discard
+            # .raw_packet_cache when needed.
+            if f.islist or f.holds_packets:
+                self.raw_packet_cache_fields[f.name] = f.do_copy(fval)
+            # Extra condition added
+            if fval is not None or f.name not in self.fields:
+                self.fields[f.name] = fval
+        assert(raw.endswith(s))
+        self.raw_packet_cache = raw[:-len(s)] if s else raw
+        self.explicit = 1
+        return s