nak continued

src/tmtccmd/cfdp/lv.py

@@ -31,7 +31,7 @@ def unpack(cls, raw_bytes: bytearray) -> CfdpLv:
         :raise ValueError: Invalid length found
         """
         detected_len = raw_bytes[0]
-        if self.len > 255:
+        if detected_len > 255:
             LOGGER.warning('Length too large for LV field')
             raise ValueError
         return cls(

src/tmtccmd/cfdp/pdu/metadata.py

@@ -38,17 +38,13 @@ def __init__(
         self.closure_requested = closure_requested
         self.checksum_type = checksum_type
         self.file_size = file_size
-        source_file_name_as_bytes = source_file_name
-        if serialize:
-            source_file_name_as_bytes = source_file_name.encode('utf-8')
+        source_file_name_as_bytes = source_file_name.encode('utf-8')
         self.source_file_name_lv = CfdpLv(
-            serialize=serialize, value=source_file_name_as_bytes
+            value=source_file_name_as_bytes
         )
-        dest_file_name_as_bytes = dest_file_name
-        if serialize:
-            dest_file_name_as_bytes = dest_file_name.encode('utf-8')
+        dest_file_name_as_bytes = dest_file_name.encode('utf-8')
         self.dest_file_name_lv = CfdpLv(
-            serialize=serialize, value=dest_file_name_as_bytes
+            value=dest_file_name_as_bytes
         )
         self.options = options
 
@@ -58,8 +54,8 @@ def __empty(cls) -> MetadataPdu:
             closure_requested=None,
             checksum_type=None,
             file_size=None,
-            source_file_name=None,
-            dest_file_name=None,
+            source_file_name="",
+            dest_file_name="",
             direction=None,
             trans_mode=None
         )
@@ -87,8 +83,8 @@ def unpack(cls, raw_packet: bytearray) -> MetadataPdu:
         # Minimal length: 1 byte + FSS (4 byte) + 2 empty LV (1 byte)
         if not check_packet_length(len(raw_packet), metadata_pdu.pdu_file_directive.get_len() + 7):
             raise ValueError
-        self.closure_requested = raw_packet[current_idx] & 0x40
-        self.checksum_type = raw_packet[current_idx] & 0x0f
+        metadata_pdu.closure_requested = raw_packet[current_idx] & 0x40
+        metadata_pdu.checksum_type = raw_packet[current_idx] & 0x0f
         current_idx += 1
         current_idx, metadata_pdu.file_size = metadata_pdu.pdu_file_directive.parse_fss_field(
             raw_packet=raw_packet, current_idx=current_idx

src/tmtccmd/cfdp/pdu/nak.py

@@ -1,5 +1,7 @@
+from __future__ import annotations
 import enum
 import struct
+from typing import List, Tuple
 
 from tmtccmd.cfdp.pdu.file_directive import FileDirectivePduBase, DirectiveCodes, \
     ConditionCode
@@ -10,25 +12,55 @@
 class NakPdu():
     def __init__(
         self,
-        serialize: bool,
         direction: Direction,
         trans_mode: TransmissionModes,
+        start_of_scope: int,
+        end_of_scope: int,
+        segment_requests: List[Tuple[int,int]],
         crc_flag: CrcFlag = CrcFlag.GLOBAL_CONFIG,
         len_entity_id: LenInBytes = LenInBytes.NONE,
         len_transaction_seq_num=LenInBytes.NONE,
     ):
         self.pdu_file_directive = FileDirectivePduBase(
-            serialize=serialize,
             directive_code=DirectiveCodes.ACK_PDU,
             direction=direction,
             trans_mode=trans_mode,
             crc_flag=crc_flag,
             len_entity_id=len_entity_id,
             len_transaction_seq_num=len_transaction_seq_num
         )
+        self.start_of_scope = start_of_scope
+        self.end_of_scope = end_of_scope
+        self.segment_requests = segment_requests
+
+    @classmethod
+    def __empty(cls) -> NakPdu:
+        return cls(
+            direction=None,
+            trans_mode=None,
+            start_of_scope=None,
+            end_of_scope=None,
+            segment_requests=None
+        )
 
     def pack(self) -> bytearray:
-        pass
+        nak_pdu = self.pdu_file_directive.pack()
+        if not self.pdu_file_directive.pdu_header.large_file:
+            nak_pdu.extend(struct.pack('!I', self.start_of_scope))
+            nak_pdu.extend(struct.pack('!I', self.end_of_scope))
+        else:
+            nak_pdu.extend(struct.pack('!Q', self.start_of_scope))
+            nak_pdu.extend(struct.pack('!Q', self.end_of_scope))
+        for segment_request in self.segment_requests:
+            if not self.pdu_file_directive.pdu_header.large_file:
+                nak_pdu.extend(struct.pack('!I', segment_request[0]))
+                nak_pdu.extend(struct.pack('!I', segment_request[1]))
+            else:
+                nak_pdu.extend(struct.pack('!Q', segment_request[0]))
+                nak_pdu.extend(struct.pack('!Q', segment_request[1]))
 
-    def unpack(self, raw_packet: bytearray):
-        pass
+    @classmethod
+    def unpack(cls, raw_packet: bytearray) -> NakPdu:
+        nak_pdu = cls.__empty()
+        nak_pdu.pdu_file_directive = FileDirectivePduBase.unpack(raw_packet=raw_packet)
+        current_idx = nak_pdu.pdu_file_directive.get_len()

src/tmtccmd/cfdp/tlv.py

@@ -59,10 +59,10 @@ def unpack(cls, raw_bytes: bytearray) -> CfdpTlv:
             LOGGER.warning('Invalid length for TLV field, less than 2')
             raise ValueError
         try:
-            self.type = TlvTypes(raw_bytes[0])
+            type = TlvTypes(raw_bytes[0])
         except ValueError:
             LOGGER.warning(
-                f'TLV field invalid, found value {self.type} is not a possible TLV parameter'
+                f'TLV field invalid, found value {type} is not a possible TLV parameter'
             )
             raise ValueError
         value = bytearray()