A packet can have multiple TLVs

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>
This commit is contained in:
Yohann D'ANELLO 2020-12-21 16:04:00 +01:00
parent a796bed259
commit 9561912ac6
Signed by: ynerant
GPG Key ID: 3A75C55819C8CF85
1 changed files with 31 additions and 22 deletions

View File

@ -6,7 +6,7 @@ from argparse import ArgumentParser
from enum import Enum
from ipaddress import IPv6Address
from threading import Thread
from typing import Any, Optional, Tuple
from typing import Any, List, Optional, Tuple
class Squinnondation:
@ -50,13 +50,14 @@ class Squinnondation:
pkt = Packet()
pkt.magic = 95
pkt.version = 0
pkt.body = DataTLV()
tlv = DataTLV()
msg = f"Hello world, my name is {squirrel.nickname}!"
pkt.body.data = msg.encode("UTF-8")
pkt.body.sender_id = 42
pkt.body.nonce = 18
pkt.body.length = len(msg) + 1 + 1 + 8 + 4
pkt.body_length = pkt.body.length + 2
tlv.data = msg.encode("UTF-8")
tlv.sender_id = 42
tlv.nonce = 18
tlv.length = len(msg) + 1 + 1 + 8 + 4
pkt.body = [tlv]
pkt.body_length = tlv.length + 2
squirrel.send_packet(hazelnut, pkt)
Worm(squirrel).start()
@ -275,7 +276,7 @@ class Packet:
magic: int
version: int
body_length: int
body: TLV
body: List[TLV]
def validate_data(self) -> bool:
"""
@ -289,7 +290,7 @@ class Packet:
if not (0 <= self.body_length <= 120):
raise ValueError("The body length of the packet is negative or too high. It must be between 0 and 1020,"
"found: {:d}".format(self.body_length))
return self.body.validate_data()
return all(tlv.validate_data() for tlv in self.body)
@staticmethod
def unmarshal(data: bytes) -> "Packet":
@ -301,11 +302,17 @@ class Packet:
pkt.magic = data[0]
pkt.version = data[1]
pkt.body_length = int.from_bytes(data[2:4], byteorder="big")
pkt.body = []
read_bytes = 0
while read_bytes <= min(len(data) - 4, pkt.body_length):
tlv_type = data[4]
if not (0 <= tlv_type < len(TLV.tlv_classes())):
raise ValueError(f"TLV type is not supported: {tlv_type}")
pkt.body = TLV.tlv_classes()[tlv_type]()
pkt.body.unmarshal(data[4:4 + pkt.body_length])
tlv = TLV.tlv_classes()[tlv_type]()
tlv.unmarshal(data[4:4 + pkt.body_length])
pkt.body.append(tlv)
# Pad1TLV has no length
read_bytes += 1 if tlv_type == 0 else tlv.length + 2
pkt.validate_data()
@ -318,7 +325,7 @@ class Packet:
data = self.magic.to_bytes(1, "big")
data += self.version.to_bytes(1, "big")
data += self.body_length.to_bytes(2, "big")
data += self.body.marshal()
data += b"".join(tlv.marshal() for tlv in self.body)
return data
@ -410,15 +417,17 @@ class Worm(Thread):
except ValueError as error:
print("An error occured while receiving a packet: ", error)
else:
print(pkt.body.data.decode('UTF-8'))
print(pkt.body[0].data.decode('UTF-8'))
pkt = Packet()
pkt.magic = 95
pkt.version = 0
pkt.body = DataTLV()
pkt.body = []
tlv = DataTLV()
msg = f"Hello my dear hazelnut, I am {self.squirrel.nickname}!"
pkt.body.data = msg.encode("UTF-8")
pkt.body.sender_id = 42
pkt.body.nonce = 18
pkt.body.length = len(msg) + 1 + 1 + 8 + 4
pkt.body_length = pkt.body.length + 2
tlv.data = msg.encode("UTF-8")
tlv.sender_id = 42
tlv.nonce = 18
tlv.length = len(msg) + 1 + 1 + 8 + 4
pkt.body.append(tlv)
pkt.body_length = tlv.length + 2
self.squirrel.send_packet(hazelnut, pkt)