Mirrors
/
Reticulum
mirror of https://github.com/markqvist/Reticulum.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Added channel example

This commit is contained in:
Aaron Heise 2023-02-26 07:26:12 -06:00
parent fe3a3e22f7
commit a61b15cf6a
No known key found for this signature in database
GPG Key ID: 6BA54088C41DE8BF
1 changed files with 375 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

375
Examples/Channel.py Normal file
View File

@ -0,0 +1,375 @@
##########################################################
# This RNS example demonstrates how to set up a link to #
# a destination, and pass structuredmessages over it #
# using a channel. #
##########################################################
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"
##########################################################
#### Shared Objects ######################################
##########################################################
# Channel data must be structured in a subclass of
# MessageBase. This ensures that the channel will be able
# to serialize and deserialize the object and multiplex it
# with other objects. Both ends of a link will need the
# same object definitions to be able to communicate over
# a channel.
#
# Note: The objects we wish to use over the channel must
# be registered with the channel, and each link has a
# different channel instance. See the client_connected
# and link_established functions in this example to see
# how message types are registered.
# Let's make a simple message class called StringMessage
# that will convey a string with a timestamp.
class StringMessage(RNS.MessageBase):
# The MSGTYPE class variable needs to be assigned a
# 2 byte integer value. This identifier allows the
# channel to look up your message's constructor when a
# message arrives over the channel.
#
# MSGTYPE must be unique across all message types we
# register with the channel
MSGTYPE = 0x0101
# The constructor of our object must be callable with
# no arguments. We can have parameters, but they must
# have a default assignment.
#
# This is needed so the channel can create an empty
# version of our message into which the incoming
# message can be unpacked.
def __init__(self, data=None):
self.data = data
self.timestamp = datetime.now()
# Finally, our message needs to implement functions
# the channel can call to pack and unpack our message
# to/from the raw packet payload. We'll use the
# umsgpack package bundled with RNS. We could also use
# the struct package bundled with Python if we wanted
# more control over the structure of the packed bytes.
#
# Also note that packed message objects must fit
# entirely in one packet. The number of bytes
# available for message payloads can be queried from
# the channel using the Channel.MDU property. The
# channel MDU is slightly less than the link MDU due
# to encoding the message header.
# The pack function encodes the message contents into
# a byte stream.
def pack(self) -> bytes:
return umsgpack.packb((self.data, self.timestamp))
# And the unpack function decodes a byte stream into
# the message contents.
def unpack(self, raw):
self.data, self.timestamp = umsgpack.unpackb(raw)
##########################################################
#### Server Part #########################################
##########################################################
# A reference to the latest client link that connected
latest_client_link = 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,
"channelexample"
)
# 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_client_link = link
RNS.log("Client connected")
link.set_link_closed_callback(client_disconnected)
# Register message types and add callback to channel
channel = link.get_channel()
channel.register_message_type(StringMessage)
channel.add_message_callback(server_message_received)
def client_disconnected(link):
RNS.log("Client disconnected")
def server_message_received(message):
global latest_client_link
# When a message is received over any active link,
# the replies will all be directed to the last client
# that connected.
if isinstance(message, StringMessage):
RNS.log("Received data on the link: " + message.data + " (message created at " + str(message.timestamp) + ")")
reply_message = StringMessage("I received \""+message.data+"\" over the link")
latest_client_link.get_channel().send(reply_message)
##########################################################
#### Client Part #########################################
##########################################################
# A reference to the server link
server_link = 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,
"channelexample"
)
# And create a link
link = RNS.Link(server_destination)
# We set a callback that will get executed
# every time a packet is received over the
# link
link.set_packet_callback(client_message_received)
# 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()
# If not, send the entered text over the link
if text != "":
message = StringMessage(text)
packed_size = len(message.pack())
channel = server_link.get_channel()
if channel.is_ready_to_send():
if packed_size <= channel.MDU:
channel.send(message)
else:
RNS.log(
"Cannot send this packet, the data size of "+
str(packed_size)+" bytes exceeds the link packet MDU of "+
str(channel.MDU)+" bytes",
RNS.LOG_ERROR
)
else:
RNS.log("Channel is not ready to send, please wait for " +
"pending messages to complete.", RNS.LOG_ERROR)
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
server_link = link
# Register messages and add handler to channel
channel = link.get_channel()
channel.register_message_type(StringMessage)
channel.add_message_callback(client_message_received)
# 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 a packet is received over the link, we
# simply print out the data.
def client_message_received(message):
if isinstance(message, StringMessage):
RNS.log("Received data on the link: " + message.data + " (message created at " + str(message.timestamp) + ")")
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 link 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()