Convert host to network byte order if necessary

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>
This commit is contained in:
Yohann D'ANELLO 2020-12-21 16:04:13 +01:00
parent 833c56755a
commit bda4860aca
Signed by: ynerant
GPG Key ID: 3A75C55819C8CF85
1 changed files with 34 additions and 40 deletions

View File

@ -4,6 +4,7 @@
from typing import Any, List, Optional
from ipaddress import IPv6Address
from enum import Enum
import socket
import sys
@ -53,13 +54,6 @@ class TLV:
def tlv_classes() -> list:
return [Pad1TLV, PadNTLV, HelloTLV, NeighbourTLV, DataTLV, AckTLV, GoAwayTLV, WarningTLV]
@staticmethod
def network_order() -> str:
"""
The network byte order is always inverted as the host network byte order.
"""
return "little" if sys.byteorder == "big" else "big"
class Pad1TLV(TLV):
"""
@ -77,7 +71,7 @@ class Pad1TLV(TLV):
"""
The TLV is empty.
"""
return self.type.to_bytes(1, TLV.network_order())
return self.type.to_bytes(1, sys.byteorder)
def handle(self, squirrel: Any, sender: Any) -> None:
# TODO Add some easter eggs
@ -100,7 +94,7 @@ class PadNTLV(TLV):
mbz: bytes
def validate_data(self) -> bool:
if self.mbz != int(0).to_bytes(self.length, TLV.network_order()):
if self.mbz != int(0).to_bytes(self.length, sys.byteorder):
raise ValueError("The body of a PadN TLV is not filled with zeros.")
return True
@ -116,7 +110,7 @@ class PadNTLV(TLV):
"""
Construct the byte array filled by zeros.
"""
return self.type.to_bytes(1, TLV.network_order()) + self.length.to_bytes(1, TLV.network_order()) \
return self.type.to_bytes(1, sys.byteorder) + self.length.to_bytes(1, sys.byteorder) \
+ self.mbz[:self.length]
def handle(self, squirrel: Any, sender: Any) -> None:
@ -139,15 +133,15 @@ class HelloTLV(TLV):
def unmarshal(self, raw_data: bytes) -> None:
self.type = raw_data[0]
self.length = raw_data[1]
self.source_id = int.from_bytes(raw_data[2:10], TLV.network_order())
self.source_id = int.from_bytes(raw_data[2:10], sys.byteorder)
if self.is_long:
self.dest_id = int.from_bytes(raw_data[10:18], TLV.network_order())
self.dest_id = int.from_bytes(raw_data[10:18], sys.byteorder)
def marshal(self) -> bytes:
data = self.type.to_bytes(1, TLV.network_order()) + self.length.to_bytes(1, TLV.network_order()) \
+ self.source_id.to_bytes(8, TLV.network_order())
data = self.type.to_bytes(1, sys.byteorder) + self.length.to_bytes(1, sys.byteorder) \
+ self.source_id.to_bytes(8, sys.byteorder)
if self.dest_id:
data += self.dest_id.to_bytes(8, TLV.network_order())
data += self.dest_id.to_bytes(8, sys.byteorder)
return data
def handle(self, squirrel: Any, sender: Any) -> None:
@ -170,13 +164,13 @@ class NeighbourTLV(TLV):
self.type = raw_data[0]
self.length = raw_data[1]
self.ip_address = IPv6Address(raw_data[2:18])
self.port = int.from_bytes(raw_data[18:20], TLV.network_order())
self.port = int.from_bytes(raw_data[18:20], sys.byteorder)
def marshal(self) -> bytes:
return self.type.to_bytes(1, TLV.network_order()) + \
self.length.to_bytes(1, TLV.network_order()) + \
return self.type.to_bytes(1, sys.byteorder) + \
self.length.to_bytes(1, sys.byteorder) + \
self.ip_address.packed + \
self.port.to_bytes(2, TLV.network_order())
self.port.to_bytes(2, sys.byteorder)
def handle(self, squirrel: Any, sender: Any) -> None:
# TODO Implement NeighbourTLV
@ -194,15 +188,15 @@ class DataTLV(TLV):
def unmarshal(self, raw_data: bytes) -> None:
self.type = raw_data[0]
self.length = raw_data[1]
self.sender_id = int.from_bytes(raw_data[2:10], TLV.network_order())
self.nonce = int.from_bytes(raw_data[10:14], TLV.network_order())
self.sender_id = int.from_bytes(raw_data[2:10], sys.byteorder)
self.nonce = socket.ntohl(int.from_bytes(raw_data[10:14], sys.byteorder))
self.data = raw_data[14:self.tlv_length]
def marshal(self) -> bytes:
return self.type.to_bytes(1, TLV.network_order()) + \
self.length.to_bytes(1, TLV.network_order()) + \
self.sender_id.to_bytes(8, TLV.network_order()) + \
self.nonce.to_bytes(4, TLV.network_order()) + \
return self.type.to_bytes(1, sys.byteorder) + \
self.length.to_bytes(1, sys.byteorder) + \
self.sender_id.to_bytes(8, sys.byteorder) + \
socket.htonl(self.nonce).to_bytes(4, sys.byteorder) + \
self.data
def handle(self, squirrel: Any, sender: Any) -> None:
@ -232,14 +226,14 @@ class AckTLV(TLV):
def unmarshal(self, raw_data: bytes) -> None:
self.type = raw_data[0]
self.length = raw_data[1]
self.sender_id = int.from_bytes(raw_data[2:10], TLV.network_order())
self.nonce = int.from_bytes(raw_data[10:14], TLV.network_order())
self.sender_id = int.from_bytes(raw_data[2:10], sys.byteorder)
self.nonce = socket.ntohl(int.from_bytes(raw_data[10:14], sys.byteorder))
def marshal(self) -> bytes:
return self.type.to_bytes(1, TLV.network_order()) + \
self.length.to_bytes(1, TLV.network_order()) + \
self.sender_id.to_bytes(8, TLV.network_order()) + \
self.nonce.to_bytes(4, TLV.network_order())
return self.type.to_bytes(1, sys.byteorder) + \
self.length.to_bytes(1, sys.byteorder) + \
self.sender_id.to_bytes(8, sys.byteorder) + \
socket.htonl(self.nonce).to_bytes(4, sys.byteorder)
def handle(self, squirrel: Any, sender: Any) -> None:
# TODO Implement AckTLV
@ -265,9 +259,9 @@ class GoAwayTLV(TLV):
self.message = raw_data[3:self.length - 1].decode("UTF-8")
def marshal(self) -> bytes:
return self.type.to_bytes(1, TLV.network_order()) + \
self.length.to_bytes(1, TLV.network_order()) + \
self.code.value.to_bytes(1, TLV.network_order()) + \
return self.type.to_bytes(1, sys.byteorder) + \
self.length.to_bytes(1, sys.byteorder) + \
self.code.value.to_bytes(1, sys.byteorder) + \
self.message.encode("UTF-8")[:self.length - 1]
def handle(self, squirrel: Any, sender: Any) -> None:
@ -287,8 +281,8 @@ class WarningTLV(TLV):
self.message = raw_data[2:self.length].decode("UTF-8")
def marshal(self) -> bytes:
return self.type.to_bytes(1, TLV.network_order()) + \
self.length.to_bytes(1, TLV.network_order()) + \
return self.type.to_bytes(1, sys.byteorder) + \
self.length.to_bytes(1, sys.byteorder) + \
self.message.encode("UTF-8")[:self.length]
def handle(self, squirrel: Any, sender: Any) -> None:
@ -327,7 +321,7 @@ class Packet:
pkt = Packet()
pkt.magic = data[0]
pkt.version = data[1]
pkt.body_length = int.from_bytes(data[2:4], byteorder=TLV.network_order())
pkt.body_length = socket.ntohs(int.from_bytes(data[2:4], sys.byteorder))
pkt.body = []
read_bytes = 0
while read_bytes <= min(len(data) - 4, pkt.body_length):
@ -347,9 +341,9 @@ class Packet:
"""
Compute the byte array data associated to the packet.
"""
data = self.magic.to_bytes(1, TLV.network_order())
data += self.version.to_bytes(1, TLV.network_order())
data += self.body_length.to_bytes(2, TLV.network_order())
data = self.magic.to_bytes(1, sys.byteorder)
data += self.version.to_bytes(1, sys.byteorder)
data += socket.htons(self.body_length).to_bytes(2, sys.byteorder)
data += b"".join(tlv.marshal() for tlv in self.body)
return data