FreeDATA/tnc/mesh.py
2023-05-28 16:06:07 +02:00

243 lines
9.8 KiB
Python

# -*- coding: UTF-8 -*-
"""
@author: DJ2LS
HF mesh networking prototype and testing module
import time
MeshParam.routing_table = [['AA1AA', 'direct', 0, 1.0, 25, time.time(), ], ['AA1AA', 'AA2BB', 1, 3.1, 10, time.time(), ],
['AA3CC', 'AA2BB', 5, -4.5, -3, time.time(), ]]
print(MeshParam.routing_table)
print("---------------------------------")
TODO: SIGNALLING FOR ACK/NACK:
- mesh-signalling burst is datac13
- mesh-signalling frame contains [message id, status]
- create a list for signalling frames, contains [message id, message-status, attempts, state, timestamp]
- on "IRS", send ACK/NACK 10 times on receiving beacon?
- on "ROUTER", receive ACK/NACK, and store it in table, also send it 10 times
- if sent 10 times, set ACK/NACK state to "done"
- if done already in list, don't reset retry counter
- delete ACK/NACK if "done" and timestamp older than 1day
"""
# pylint: disable=invalid-name, line-too-long, c-extension-no-member
# pylint: disable=import-outside-toplevel, attribute-defined-outside-init
from static import TNC, MeshParam, FRAME_TYPE, Station, ModemParam
from codec2 import FREEDV_MODE
import numpy as np
import time
import threading
import modem
import helpers
import structlog
from queues import MESH_RECEIVED_QUEUE
class MeshRouter():
def __init__(self):
self.log = structlog.get_logger("RF")
self.mesh_broadcasting_thread = threading.Thread(
target=self.broadcast_routing_table, name="worker thread receive", daemon=True
)
self.mesh_broadcasting_thread.start()
self.mesh_rx_dispatcher_thread = threading.Thread(
target=self.mesh_rx_dispatcher, name="worker thread receive", daemon=True
)
self.mesh_rx_dispatcher_thread.start()
def get_from_heard_stations(self):
"""
get data from heard stations
heard stations format:
[dxcallsign,dxgrid,int(time.time()),datatype,snr,offset,frequency]
TNC.heard_stations.append(
[
dxcallsign,
dxgrid,
int(time.time()),
datatype,
snr,
offset,
frequency,
]
)
"""
dxcallsign_position = 0
dxgrid_position = 1
timestamp_position = 2
type_position = 3
snr_position = 4
offset_position = 5
frequency_position = 6
try:
for item in TNC.heard_stations:
print("-----------")
print(item)
print(item[snr_position])
try:
print(item[snr_position])
snr = bytes(item[snr_position], "utf-8").split(b"/")
snr = int(float(snr[0]))
except Exception as err:
snr = int(float(item[snr_position]))
new_router = [helpers.get_crc_24(item[dxcallsign_position]), helpers.get_crc_24(b'direct'), 0, snr, snr, item[timestamp_position]]
self.add_router_to_routing_table(new_router)
except Exception as e:
self.log.warning("[MESH] error fetching data from heard station list", e=e)
def add_router_to_routing_table(self, new_router):
try:
# destination callsign # router callsign # hops # rx snr # route quality # timestamp
for _, item in enumerate(MeshParam.routing_table):
# update routing entry if exists
if new_router[0] in item[0] and new_router[1] in item[1]:
print(f"UPDATE {MeshParam.routing_table[_]} >>> {new_router}")
MeshParam.routing_table[_] = new_router
# add new routing entry if not exists
if new_router not in MeshParam.routing_table:
print(f"INSERT {new_router} >>> ROUTING TABLE")
MeshParam.routing_table.append(new_router)
except Exception as e:
self.log.warning("[MESH] error adding data to routing table", e=e, router=new_router)
def broadcast_routing_table(self, interval=40):
# enable receiving for datac4 if broadcasting
modem.RECEIVE_DATAC4 = True
while True:
try:
# wait some time until sending routing table
threading.Event().wait(interval)
# before we are transmitting, let us update our routing table
self.get_from_heard_stations()
#[b'DJ2LS-0', 'direct', 0, 9.6, 9.6, 1684912305]
mesh_broadcast_frame_header = bytearray(4)
mesh_broadcast_frame_header[:1] = bytes([FRAME_TYPE.MESH_BROADCAST.value])
mesh_broadcast_frame_header[1:4] = helpers.get_crc_24(Station.mycallsign)
# callsign(6), router(6), hops(1), path_score(1) == 14 ==> 14 28 42 ==> 3 mesh routing entries
# callsign_crc(3), router_crc(3), hops(1), path_score(1) == 8 --> 6
# callsign_crc(3), hops(1), path_score(1) == 5 --> 10
# Create a new bytearray with a fixed length of 50
result = bytearray(50)
# Iterate over the route subarrays and add the selected entries to the result bytearray
index = 0
for route_id, route in enumerate(MeshParam.routing_table):
# the value 5 is the length of crc24 + hops + score
dxcall = MeshParam.routing_table[route_id][0]
# router = MeshParam.routing_table[i][1]
hops = MeshParam.routing_table[route_id][2]
# snr = MeshParam.routing_table[i][3]
route_score = np.clip(MeshParam.routing_table[route_id][4], 0, 254)
# timestamp = MeshParam.routing_table[i][5]
result[index:index + 5] = dxcall + bytes([hops]) + bytes([route_score])
index += 5
print(len(result))
# Split the result bytearray into a list of fixed-length bytearrays
split_result = [result[i:i + 50] for i in range(0, len(result), 50)]
print(len(split_result))
frame_list = []
for _ in split_result:
# make sure payload is always 50
_[len(_):] = bytes(50 - len(_))
#print(len(_))
frame_list.append(mesh_broadcast_frame_header + _)
print(frame_list)
TNC.transmitting = True
c2_mode = FREEDV_MODE.datac4.value
modem.MODEM_TRANSMIT_QUEUE.put([c2_mode, 1, 0, frame_list])
# Wait while transmitting
while TNC.transmitting:
threading.Event().wait(0.01)
except Exception as e:
self.log.warning("[MESH] broadcasting routing table", e=e)
def mesh_rx_dispatcher(self):
while True:
data_in = MESH_RECEIVED_QUEUE.get()
if int.from_bytes(data_in[:1], "big") in [FRAME_TYPE.MESH_BROADCAST.value]:
self.received_routing_table(data_in[:-2])
else:
print("wrong mesh data received")
print(data_in)
def received_routing_table(self, data_in):
try:
print("data received........")
print(data_in)
router = data_in[1:4] # Extract the first 4 bytes (header)
payload = data_in[4:] # Extract the payload (excluding the header)
print("Router:", router) # Output the header bytes
for i in range(0, len(payload)-1, 5):
callsign_checksum = payload[i:i + 3] # First 3 bytes of the information (callsign_checksum)
hops = int.from_bytes(payload[i+3:i + 4], "big") # Fourth byte of the information (hops)
score = int.from_bytes(payload[i+4:i + 5], "big") # Fifth byte of the information (score)
timestamp = int(time.time())
snr = int(ModemParam.snr)
# use case 1: add new router to table only if callsign not empty
_use_case1 = callsign_checksum.startswith(b'\x00')
# use case 2: add new router to table only if not own callsign
_use_case2 = callsign_checksum not in [helpers.get_crc_24(Station.mycallsign)]
# use case 3: increment hop if router not direct
if router not in [helpers.get_crc_24(b'direct')] and hops == 0:
hops += 1
# use case 4: if callsign is directly available skip route for only keeping shortest way in db
_use_case4 = False
for _, call in enumerate(MeshParam.routing_table):
# check if callsign already in routing table and is direct connection
if callsign_checksum in [MeshParam.routing_table[_][0]] and MeshParam.routing_table[_][1] in [helpers.get_crc_24(b'direct')]:
_use_case4 = True
# use case N: calculate score
# TODO...
if not _use_case1 \
and _use_case2\
and not _use_case4:
print("Callsign Checksum:", callsign_checksum)
print("Hops:", hops)
print("Score:", score)
new_router = [callsign_checksum, router, hops, snr, score, timestamp]
print(new_router)
self.add_router_to_routing_table(new_router)
print("-------------------------")
for _, item in enumerate(MeshParam.routing_table):
print(MeshParam.routing_table[_])
print("-------------------------")
except Exception as e:
self.log.warning("[MESH] error processing received routing broadcast", e=e)