Reticulum/Examples/Echo.py
2021-05-20 22:31:09 +02:00

281 lines
9.9 KiB
Python

##########################################################
# This RNS example demonstrates a simple client/server #
# echo utility. A client can send an echo request to the #
# server, and the server will respond by proving receipt #
# of the packet. #
##########################################################
import argparse
import RNS
# Let's define an app name. We'll use this for all
# destinations we create. Since this echo example
# is part of a range of example utilities, we'll put
# them all within the app namespace "example_utilities"
APP_NAME = "example_utilities"
##########################################################
#### Server Part #########################################
##########################################################
# This initialisation is executed when the users chooses
# to run as a server
def server(configpath):
# We must first initialise Reticulum
reticulum = RNS.Reticulum(configpath)
# Randomly create a new identity for our echo server
server_identity = RNS.Identity()
# We create a destination that clients can query. We want
# to be able to verify echo replies to our clients, so we
# create a "single" destination that can receive encrypted
# messages. This way the client can send a request and be
# certain that no-one else than this destination was able
# to read it.
echo_destination = RNS.Destination(
server_identity,
RNS.Destination.IN,
RNS.Destination.SINGLE,
APP_NAME,
"echo",
"request"
)
# We configure the destination to automatically prove all
# packets adressed to it. By doing this, RNS will automatically
# generate a proof for each incoming packet and transmit it
# back to the sender of that packet.
echo_destination.set_proof_strategy(RNS.Destination.PROVE_ALL)
# Tell the destination which function in our program to
# run when a packet is received. We do this so we can
# print a log message when the server receives a request
echo_destination.set_packet_callback(server_callback)
# Everything's ready!
# Let's Wait for client requests or user input
announceLoop(echo_destination)
def announceLoop(destination):
# Let the user know that everything is ready
RNS.log(
"Echo server "+
RNS.prettyhexrep(destination.hash)+
" running, hit enter to manually send an announce (Ctrl-C to quit)"
)
# We enter a loop that runs until the users exits.
# If the user hits enter, we will announce our server
# destination on the network, which will let clients
# know how to create messages directed towards it.
while True:
entered = input()
destination.announce()
RNS.log("Sent announce from "+RNS.prettyhexrep(destination.hash))
def server_callback(message, packet):
# Tell the user that we received an echo request, and
# that we are going to send a reply to the requester.
# Sending the proof is handled automatically, since we
# set up the destination to prove all incoming packets.
RNS.log("Received packet from echo client, proof sent")
##########################################################
#### Client Part #########################################
##########################################################
# This initialisation is executed when the users chooses
# to run as a client
def client(destination_hexhash, configpath, timeout=None):
# We need a binary representation of the destination
# hash that was entered on the command line
try:
if len(destination_hexhash) != 20:
raise ValueError(
"Destination length is invalid, must be 20 hexadecimal characters (10 bytes)"
)
destination_hash = bytes.fromhex(destination_hexhash)
except:
RNS.log("Invalid destination entered. Check your input!\n")
exit()
# We must first initialise Reticulum
reticulum = RNS.Reticulum(configpath)
# We override the loglevel to provide feedback when
# an announce is received
if RNS.loglevel < RNS.LOG_INFO:
RNS.loglevel = RNS.LOG_INFO
# Tell the user that the client is ready!
RNS.log(
"Echo client ready, hit enter to send echo request to "+
destination_hexhash+
" (Ctrl-C to quit)"
)
# We enter a loop that runs until the user exits.
# If the user hits enter, we will try to send an
# echo request to the destination specified on the
# command line.
while True:
input()
# Let's first check if RNS knows a path to the destination.
# If it does, we'll load the server identity and create a packet
if RNS.Transport.has_path(destination_hash):
# To address the server, we need to know it's public
# key, so we check if Reticulum knows this destination.
# This is done by calling the "recall" method of the
# Identity module. If the destination is known, it will
# return an Identity instance that can be used in
# outgoing destinations.
server_identity = RNS.Identity.recall(destination_hash)
# We got the correct identity instance from the
# recall method, so let's create an outgoing
# destination. We use the naming convention:
# example_utilities.echo.request
# This matches the naming we specified in the
# server part of the code.
request_destination = RNS.Destination(
server_identity,
RNS.Destination.OUT,
RNS.Destination.SINGLE,
APP_NAME,
"echo",
"request"
)
# The destination is ready, so let's create a packet.
# We set the destination to the request_destination
# that was just created, and the only data we add
# is a random hash.
echo_request = RNS.Packet(request_destination, RNS.Identity.get_random_hash())
# Send the packet! If the packet is successfully
# sent, it will return a PacketReceipt instance.
packet_receipt = echo_request.send()
# If the user specified a timeout, we set this
# timeout on the packet receipt, and configure
# a callback function, that will get called if
# the packet times out.
if timeout != None:
packet_receipt.set_timeout(timeout)
packet_receipt.set_timeout_callback(packet_timed_out)
# We can then set a delivery callback on the receipt.
# This will get automatically called when a proof for
# this specific packet is received from the destination.
packet_receipt.set_delivery_callback(packet_delivered)
# Tell the user that the echo request was sent
RNS.log("Sent echo request to "+RNS.prettyhexrep(request_destination.hash))
else:
# If we do not know this destination, tell the
# user to wait for an announce to arrive.
RNS.log("Destination is not yet known. Requesting path...")
RNS.Transport.request_path(destination_hash)
# This function is called when our reply destination
# receives a proof packet.
def packet_delivered(receipt):
if receipt.status == RNS.PacketReceipt.DELIVERED:
rtt = receipt.get_rtt()
if (rtt >= 1):
rtt = round(rtt, 3)
rttstring = str(rtt)+" seconds"
else:
rtt = round(rtt*1000, 3)
rttstring = str(rtt)+" milliseconds"
RNS.log(
"Valid reply received from "+
RNS.prettyhexrep(receipt.destination.hash)+
", round-trip time is "+rttstring
)
# This function is called if a packet times out.
def packet_timed_out(receipt):
if receipt.status == RNS.PacketReceipt.FAILED:
RNS.log("Packet "+RNS.prettyhexrep(receipt.hash)+" timed out")
##########################################################
#### Program Startup #####################################
##########################################################
# This part of the program gets run at startup,
# and parses input from the user, and then starts
# the desired program mode.
if __name__ == "__main__":
try:
parser = argparse.ArgumentParser(description="Simple echo server and client utility")
parser.add_argument(
"-s",
"--server",
action="store_true",
help="wait for incoming packets from clients"
)
parser.add_argument(
"-t",
"--timeout",
action="store",
metavar="s",
default=None,
help="set a reply timeout in seconds",
type=float
)
parser.add_argument("--config",
action="store",
default=None,
help="path to alternative Reticulum config directory",
type=str
)
parser.add_argument(
"destination",
nargs="?",
default=None,
help="hexadecimal hash of the server destination",
type=str
)
args = parser.parse_args()
if args.server:
configarg=None
if args.config:
configarg = args.config
server(configarg)
else:
if args.config:
configarg = args.config
else:
configarg = None
if args.timeout:
timeoutarg = float(args.timeout)
else:
timeoutarg = None
if (args.destination == None):
print("")
parser.print_help()
print("")
else:
client(args.destination, configarg, timeout=timeoutarg)
except KeyboardInterrupt:
print("")
exit()