Reticulum/Examples/Buffer.py

323 lines
9.9 KiB
Python

##########################################################
# This RNS example demonstrates how to set up a link to #
# a destination, and pass binary data over it using a #
# using a channel buffer. #
##########################################################
from __future__ import annotations
import os
import sys
import time
import argparse
from datetime import datetime
import RNS
from RNS.vendor import umsgpack
# 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 #########################################
##########################################################
# A reference to the latest client link that connected
latest_client_link = None
# A reference to the latest buffer object
latest_buffer = None
# 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 link example
server_identity = RNS.Identity()
# We create a destination that clients can connect to. We
# want clients to create links to this destination, so we
# need to create a "single" destination type.
server_destination = RNS.Destination(
server_identity,
RNS.Destination.IN,
RNS.Destination.SINGLE,
APP_NAME,
"bufferexample"
)
# We configure a function that will get called every time
# a new client creates a link to this destination.
server_destination.set_link_established_callback(client_connected)
# Everything's ready!
# Let's Wait for client requests or user input
server_loop(server_destination)
def server_loop(destination):
# Let the user know that everything is ready
RNS.log(
"Link example "+
RNS.prettyhexrep(destination.hash)+
" running, waiting for a connection."
)
RNS.log("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))
# When a client establishes a link to our server
# destination, this function will be called with
# a reference to the link.
def client_connected(link):
global latest_client_link, latest_buffer
latest_client_link = link
RNS.log("Client connected")
link.set_link_closed_callback(client_disconnected)
# If a new connection is received, the old reader
# needs to be disconnected.
if latest_buffer:
latest_buffer.close()
# Create buffer objects.
# The stream_id parameter to these functions is
# a bit like a file descriptor, except that it
# is unique to the *receiver*.
#
# In this example, both the reader and the writer
# use stream_id = 0, but there are actually two
# separate unidirectional streams flowing in
# opposite directions.
#
channel = link.get_channel()
latest_buffer = RNS.Buffer.create_bidirectional_buffer(0, 0, channel, server_buffer_ready)
def client_disconnected(link):
RNS.log("Client disconnected")
def server_buffer_ready(ready_bytes: int):
"""
Callback from buffer when buffer has data available
:param ready_bytes: The number of bytes ready to read
"""
global latest_buffer
data = latest_buffer.read(ready_bytes)
data = data.decode("utf-8")
RNS.log("Received data on the link: " + data)
reply_message = "I received \""+data+"\" over the buffer"
reply_message = reply_message.encode("utf-8")
latest_buffer.write(reply_message)
latest_buffer.flush()
##########################################################
#### Client Part #########################################
##########################################################
# A reference to the server link
server_link = None
# A reference to the buffer object, needed to share the
# object from the link connected callback to the client
# loop.
buffer = None
# This initialisation is executed when the users chooses
# to run as a client
def client(destination_hexhash, configpath):
# We need a binary representation of the destination
# hash that was entered on the command line
try:
dest_len = (RNS.Reticulum.TRUNCATED_HASHLENGTH//8)*2
if len(destination_hexhash) != dest_len:
raise ValueError(
"Destination length is invalid, must be {hex} hexadecimal characters ({byte} bytes).".format(hex=dest_len, byte=dest_len//2)
)
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)
# Check if we know a path to the destination
if not RNS.Transport.has_path(destination_hash):
RNS.log("Destination is not yet known. Requesting path and waiting for announce to arrive...")
RNS.Transport.request_path(destination_hash)
while not RNS.Transport.has_path(destination_hash):
time.sleep(0.1)
# Recall the server identity
server_identity = RNS.Identity.recall(destination_hash)
# Inform the user that we'll begin connecting
RNS.log("Establishing link with server...")
# When the server identity is known, we set
# up a destination
server_destination = RNS.Destination(
server_identity,
RNS.Destination.OUT,
RNS.Destination.SINGLE,
APP_NAME,
"bufferexample"
)
# And create a link
link = RNS.Link(server_destination)
# We'll also set up functions to inform the
# user when the link is established or closed
link.set_link_established_callback(link_established)
link.set_link_closed_callback(link_closed)
# Everything is set up, so let's enter a loop
# for the user to interact with the example
client_loop()
def client_loop():
global server_link
# Wait for the link to become active
while not server_link:
time.sleep(0.1)
should_quit = False
while not should_quit:
try:
print("> ", end=" ")
text = input()
# Check if we should quit the example
if text == "quit" or text == "q" or text == "exit":
should_quit = True
server_link.teardown()
else:
# Otherwise, encode the text and write it to the buffer.
text = text.encode("utf-8")
buffer.write(text)
# Flush the buffer to force the data to be sent.
buffer.flush()
except Exception as e:
RNS.log("Error while sending data over the link: "+str(e))
should_quit = True
server_link.teardown()
# This function is called when a link
# has been established with the server
def link_established(link):
# We store a reference to the link
# instance for later use
global server_link, buffer
server_link = link
# Create buffer, see server_client_connected() for
# more detail about setting up the buffer.
channel = link.get_channel()
buffer = RNS.Buffer.create_bidirectional_buffer(0, 0, channel, client_buffer_ready)
# Inform the user that the server is
# connected
RNS.log("Link established with server, enter some text to send, or \"quit\" to quit")
# When a link is closed, we'll inform the
# user, and exit the program
def link_closed(link):
if link.teardown_reason == RNS.Link.TIMEOUT:
RNS.log("The link timed out, exiting now")
elif link.teardown_reason == RNS.Link.DESTINATION_CLOSED:
RNS.log("The link was closed by the server, exiting now")
else:
RNS.log("Link closed, exiting now")
RNS.Reticulum.exit_handler()
time.sleep(1.5)
os._exit(0)
# When the buffer has new data, read it and write it to the terminal.
def client_buffer_ready(ready_bytes: int):
global buffer
data = buffer.read(ready_bytes)
RNS.log("Received data on the link: " + data.decode("utf-8"))
print("> ", end=" ")
sys.stdout.flush()
##########################################################
#### Program Startup #####################################
##########################################################
# This part of the program runs at startup,
# and parses input of from the user, and then
# starts up the desired program mode.
if __name__ == "__main__":
try:
parser = argparse.ArgumentParser(description="Simple buffer example")
parser.add_argument(
"-s",
"--server",
action="store_true",
help="wait for incoming link requests from clients"
)
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.config:
configarg = args.config
else:
configarg = None
if args.server:
server(configarg)
else:
if (args.destination == None):
print("")
parser.print_help()
print("")
else:
client(args.destination, configarg)
except KeyboardInterrupt:
print("")
exit()