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Merge pull request #245 from acehoss/feature/channel

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Channel: reliable delivery over Link
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Examples/Channel.py Normal file
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##########################################################
# This RNS example demonstrates how to set up a link to #
# a destination, and pass structured messages 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. MSGTYPEs >= 0xf000 are
# reserved for the system.
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_handler(server_message_received)
def client_disconnected(link):
RNS.log("Client disconnected")
def server_message_received(message):
"""
A message handler
@param message: An instance of a subclass of MessageBase
@return: True if message was handled
"""
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.
# In a message handler, any deserializable message
# that arrives over the link's channel will be passed
# to all message handlers, unless a preceding handler indicates it
# has handled the message.
#
#
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)
# Incoming messages are sent to each message
# handler added to the channel, in the order they
# were added.
# If any message handler returns True, the message
# is considered handled and any subsequent
# handlers are skipped.
return True
##########################################################
#### 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_handler(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()

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# MIT License
#
# Copyright (c) 2016-2023 Mark Qvist / unsigned.io and contributors.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
from __future__ import annotations
import collections
import enum
import threading
import time
from types import TracebackType
from typing import Type, Callable, TypeVar, Generic, NewType
import abc
import contextlib
import struct
import RNS
from abc import ABC, abstractmethod
TPacket = TypeVar("TPacket")
class ChannelOutletBase(ABC, Generic[TPacket]):
"""
An abstract transport layer interface used by Channel.
DEPRECATED: This was created for testing; eventually
Channel will use Link or a LinkBase interface
directly.
"""
@abstractmethod
def send(self, raw: bytes) -> TPacket:
raise NotImplemented()
@abstractmethod
def resend(self, packet: TPacket) -> TPacket:
raise NotImplemented()
@property
@abstractmethod
def mdu(self):
raise NotImplemented()
@property
@abstractmethod
def rtt(self):
raise NotImplemented()
@property
@abstractmethod
def is_usable(self):
raise NotImplemented()
@abstractmethod
def get_packet_state(self, packet: TPacket) -> MessageState:
raise NotImplemented()
@abstractmethod
def timed_out(self):
raise NotImplemented()
@abstractmethod
def __str__(self):
raise NotImplemented()
@abstractmethod
def set_packet_timeout_callback(self, packet: TPacket, callback: Callable[[TPacket], None] | None,
timeout: float | None = None):
raise NotImplemented()
@abstractmethod
def set_packet_delivered_callback(self, packet: TPacket, callback: Callable[[TPacket], None] | None):
raise NotImplemented()
@abstractmethod
def get_packet_id(self, packet: TPacket) -> any:
raise NotImplemented()
class CEType(enum.IntEnum):
"""
ChannelException type codes
"""
ME_NO_MSG_TYPE = 0
ME_INVALID_MSG_TYPE = 1
ME_NOT_REGISTERED = 2
ME_LINK_NOT_READY = 3
ME_ALREADY_SENT = 4
ME_TOO_BIG = 5
class ChannelException(Exception):
"""
An exception thrown by Channel, with a type code.
"""
def __init__(self, ce_type: CEType, *args):
super().__init__(args)
self.type = ce_type
class MessageState(enum.IntEnum):
"""
Set of possible states for a Message
"""
MSGSTATE_NEW = 0
MSGSTATE_SENT = 1
MSGSTATE_DELIVERED = 2
MSGSTATE_FAILED = 3
class MessageBase(abc.ABC):
"""
Base type for any messages sent or received on a Channel.
Subclasses must define the two abstract methods as well as
the ``MSGTYPE`` class variable.
"""
# MSGTYPE must be unique within all classes sent over a
# channel. Additionally, MSGTYPE > 0xf000 are reserved.
MSGTYPE = None
"""
Defines a unique identifier for a message class.
* Must be unique within all classes registered with a ``Channel``
* Must be less than ``0xf000``. Values greater than or equal to ``0xf000`` are reserved.
"""
@abstractmethod
def pack(self) -> bytes:
"""
Create and return the binary representation of the message
:return: binary representation of message
"""
raise NotImplemented()
@abstractmethod
def unpack(self, raw: bytes):
"""
Populate message from binary representation
:param raw: binary representation
"""
raise NotImplemented()
MessageCallbackType = NewType("MessageCallbackType", Callable[[MessageBase], bool])
class Envelope:
"""
Internal wrapper used to transport messages over a channel and
track its state within the channel framework.
"""
def unpack(self, message_factories: dict[int, Type]) -> MessageBase:
msgtype, self.sequence, length = struct.unpack(">HHH", self.raw[:6])
raw = self.raw[6:]
ctor = message_factories.get(msgtype, None)
if ctor is None:
raise ChannelException(CEType.ME_NOT_REGISTERED, f"Unable to find constructor for Channel MSGTYPE {hex(msgtype)}")
message = ctor()
message.unpack(raw)
return message
def pack(self) -> bytes:
if self.message.__class__.MSGTYPE is None:
raise ChannelException(CEType.ME_NO_MSG_TYPE, f"{self.message.__class__} lacks MSGTYPE")
data = self.message.pack()
self.raw = struct.pack(">HHH", self.message.MSGTYPE, self.sequence, len(data)) + data
return self.raw
def __init__(self, outlet: ChannelOutletBase, message: MessageBase = None, raw: bytes = None, sequence: int = None):
self.ts = time.time()
self.id = id(self)
self.message = message
self.raw = raw
self.packet: TPacket = None
self.sequence = sequence
self.outlet = outlet
self.tries = 0
self.tracked = False
class Channel(contextlib.AbstractContextManager):
"""
Provides reliable delivery of messages over
a link.
``Channel`` differs from ``Request`` and
``Resource`` in some important ways:
**Continuous**
Messages can be sent or received as long as
the ``Link`` is open.
**Bi-directional**
Messages can be sent in either direction on
the ``Link``; neither end is the client or
server.
**Size-constrained**
Messages must be encoded into a single packet.
``Channel`` is similar to ``Packet``, except that it
provides reliable delivery (automatic retries) as well
as a structure for exchanging several types of
messages over the ``Link``.
``Channel`` is not instantiated directly, but rather
obtained from a ``Link`` with ``get_channel()``.
"""
def __init__(self, outlet: ChannelOutletBase):
"""
@param outlet:
"""
self._outlet = outlet
self._lock = threading.RLock()
self._tx_ring: collections.deque[Envelope] = collections.deque()
self._rx_ring: collections.deque[Envelope] = collections.deque()
self._message_callbacks: [MessageCallbackType] = []
self._next_sequence = 0
self._message_factories: dict[int, Type[MessageBase]] = {}
self._max_tries = 5
def __enter__(self) -> Channel:
return self
def __exit__(self, __exc_type: Type[BaseException] | None, __exc_value: BaseException | None,
__traceback: TracebackType | None) -> bool | None:
self._shutdown()
return False
def register_message_type(self, message_class: Type[MessageBase]):
"""
Register a message class for reception over a ``Channel``.
Message classes must extend ``MessageBase``.
:param message_class: Class to register
"""
self._register_message_type(message_class, is_system_type=False)
def _register_message_type(self, message_class: Type[MessageBase], *, is_system_type: bool = False):
with self._lock:
if not issubclass(message_class, MessageBase):
raise ChannelException(CEType.ME_INVALID_MSG_TYPE,
f"{message_class} is not a subclass of {MessageBase}.")
if message_class.MSGTYPE is None:
raise ChannelException(CEType.ME_INVALID_MSG_TYPE,
f"{message_class} has invalid MSGTYPE class attribute.")
if message_class.MSGTYPE >= 0xf000 and not is_system_type:
raise ChannelException(CEType.ME_INVALID_MSG_TYPE,
f"{message_class} has system-reserved message type.")
try:
message_class()
except Exception as ex:
raise ChannelException(CEType.ME_INVALID_MSG_TYPE,
f"{message_class} raised an exception when constructed with no arguments: {ex}")
self._message_factories[message_class.MSGTYPE] = message_class
def add_message_handler(self, callback: MessageCallbackType):
"""
Add a handler for incoming messages. A handler
has the following signature:
``(message: MessageBase) -> bool``
Handlers are processed in the order they are
added. If any handler returns True, processing
of the message stops; handlers after the
returning handler will not be called.
:param callback: Function to call
"""
with self._lock:
if callback not in self._message_callbacks:
self._message_callbacks.append(callback)
def remove_message_handler(self, callback: MessageCallbackType):
"""
Remove a handler added with ``add_message_handler``.
:param callback: handler to remove
"""
with self._lock:
self._message_callbacks.remove(callback)
def _shutdown(self):
with self._lock:
self._message_callbacks.clear()
self._clear_rings()
def _clear_rings(self):
with self._lock:
for envelope in self._tx_ring:
if envelope.packet is not None:
self._outlet.set_packet_timeout_callback(envelope.packet, None)
self._outlet.set_packet_delivered_callback(envelope.packet, None)
self._tx_ring.clear()
self._rx_ring.clear()
def _emplace_envelope(self, envelope: Envelope, ring: collections.deque[Envelope]) -> bool:
with self._lock:
i = 0
for existing in ring:
if existing.sequence > envelope.sequence \
and not existing.sequence // 2 > envelope.sequence: # account for overflow
ring.insert(i, envelope)
return True
if existing.sequence == envelope.sequence:
RNS.log(f"Envelope: Emplacement of duplicate envelope sequence.", RNS.LOG_EXTREME)
return False
i += 1
envelope.tracked = True
ring.append(envelope)
return True
def _prune_rx_ring(self):
with self._lock:
# Implementation for fixed window = 1
stale = list(sorted(self._rx_ring, key=lambda env: env.sequence, reverse=True))[1:]
for env in stale:
env.tracked = False
self._rx_ring.remove(env)
def _run_callbacks(self, message: MessageBase):
with self._lock:
cbs = self._message_callbacks.copy()
for cb in cbs:
try:
if cb(message):
return
except Exception as ex:
RNS.log(f"Channel: Error running message callback: {ex}", RNS.LOG_ERROR)
def _receive(self, raw: bytes):
try:
envelope = Envelope(outlet=self._outlet, raw=raw)
with self._lock:
message = envelope.unpack(self._message_factories)
is_new = self._emplace_envelope(envelope, self._rx_ring)
self._prune_rx_ring()
if not is_new:
RNS.log("Channel: Duplicate message received", RNS.LOG_DEBUG)
return
RNS.log(f"Message received: {message}", RNS.LOG_DEBUG)
threading.Thread(target=self._run_callbacks, name="Message Callback", args=[message], daemon=True).start()
except Exception as ex:
RNS.log(f"Channel: Error receiving data: {ex}")
def is_ready_to_send(self) -> bool:
"""
Check if ``Channel`` is ready to send.
:return: True if ready
"""
if not self._outlet.is_usable:
RNS.log("Channel: Link is not usable.", RNS.LOG_EXTREME)
return False
with self._lock:
for envelope in self._tx_ring:
if envelope.outlet == self._outlet and (not envelope.packet
or self._outlet.get_packet_state(envelope.packet) == MessageState.MSGSTATE_SENT):
RNS.log("Channel: Link has a pending message.", RNS.LOG_EXTREME)
return False
return True
def _packet_tx_op(self, packet: TPacket, op: Callable[[TPacket], bool]):
with self._lock:
envelope = next(filter(lambda e: self._outlet.get_packet_id(e.packet) == self._outlet.get_packet_id(packet),
self._tx_ring), None)
if envelope and op(envelope):
envelope.tracked = False
if envelope in self._tx_ring:
self._tx_ring.remove(envelope)
else:
RNS.log("Channel: Envelope not found in TX ring", RNS.LOG_DEBUG)
if not envelope:
RNS.log("Channel: Spurious message received.", RNS.LOG_EXTREME)
def _packet_delivered(self, packet: TPacket):
self._packet_tx_op(packet, lambda env: True)
def _packet_timeout(self, packet: TPacket):
def retry_envelope(envelope: Envelope) -> bool:
if envelope.tries >= self._max_tries:
RNS.log("Channel: Retry count exceeded, tearing down Link.", RNS.LOG_ERROR)
self._shutdown() # start on separate thread?
self._outlet.timed_out()
return True
envelope.tries += 1
self._outlet.resend(envelope.packet)
return False
self._packet_tx_op(packet, retry_envelope)
def send(self, message: MessageBase) -> Envelope:
"""
Send a message. If a message send is attempted and
``Channel`` is not ready, an exception is thrown.
:param message: an instance of a ``MessageBase`` subclass
"""
envelope: Envelope | None = None
with self._lock:
if not self.is_ready_to_send():
raise ChannelException(CEType.ME_LINK_NOT_READY, f"Link is not ready")
envelope = Envelope(self._outlet, message=message, sequence=self._next_sequence)
self._next_sequence = (self._next_sequence + 1) % 0x10000
self._emplace_envelope(envelope, self._tx_ring)
if envelope is None:
raise BlockingIOError()
envelope.pack()
if len(envelope.raw) > self._outlet.mdu:
raise ChannelException(CEType.ME_TOO_BIG, f"Packed message too big for packet: {len(envelope.raw)} > {self._outlet.mdu}")
envelope.packet = self._outlet.send(envelope.raw)
envelope.tries += 1
self._outlet.set_packet_delivered_callback(envelope.packet, self._packet_delivered)
self._outlet.set_packet_timeout_callback(envelope.packet, self._packet_timeout)
return envelope
@property
def MDU(self):
"""
Maximum Data Unit: the number of bytes available
for a message to consume in a single send. This
value is adjusted from the ``Link`` MDU to accommodate
message header information.
:return: number of bytes available
"""
return self._outlet.mdu - 6 # sizeof(msgtype) + sizeof(length) + sizeof(sequence)
class LinkChannelOutlet(ChannelOutletBase):
"""
An implementation of ChannelOutletBase for RNS.Link.
Allows Channel to send packets over an RNS Link with
Packets.
:param link: RNS Link to wrap
"""
def __init__(self, link: RNS.Link):
self.link = link
def send(self, raw: bytes) -> RNS.Packet:
packet = RNS.Packet(self.link, raw, context=RNS.Packet.CHANNEL)
packet.send()
return packet
def resend(self, packet: RNS.Packet) -> RNS.Packet:
if not packet.resend():
RNS.log("Failed to resend packet", RNS.LOG_ERROR)
return packet
@property
def mdu(self):
return self.link.MDU
@property
def rtt(self):
return self.link.rtt
@property
def is_usable(self):
return True # had issues looking at Link.status
def get_packet_state(self, packet: TPacket) -> MessageState:
status = packet.receipt.get_status()
if status == RNS.PacketReceipt.SENT:
return MessageState.MSGSTATE_SENT
if status == RNS.PacketReceipt.DELIVERED:
return MessageState.MSGSTATE_DELIVERED
if status == RNS.PacketReceipt.FAILED:
return MessageState.MSGSTATE_FAILED
else:
raise Exception(f"Unexpected receipt state: {status}")
def timed_out(self):
self.link.teardown()
def __str__(self):
return f"{self.__class__.__name__}({self.link})"
def set_packet_timeout_callback(self, packet: RNS.Packet, callback: Callable[[RNS.Packet], None] | None,
timeout: float | None = None):
if timeout:
packet.receipt.set_timeout(timeout)
def inner(receipt: RNS.PacketReceipt):
callback(packet)
if packet and packet.receipt:
packet.receipt.set_timeout_callback(inner if callback else None)
def set_packet_delivered_callback(self, packet: RNS.Packet, callback: Callable[[RNS.Packet], None] | None):
def inner(receipt: RNS.PacketReceipt):
callback(packet)
if packet and packet.receipt:
packet.receipt.set_delivery_callback(inner if callback else None)
def get_packet_id(self, packet: RNS.Packet) -> any:
return packet.get_hash()

22
RNS/Link.py
View File

@ -22,6 +22,7 @@
from RNS.Cryptography import X25519PrivateKey, X25519PublicKey, Ed25519PrivateKey, Ed25519PublicKey
from RNS.Cryptography import Fernet
from RNS.Channel import Channel, LinkChannelOutlet
from time import sleep
from .vendor import umsgpack as umsgpack
@ -163,6 +164,7 @@ class Link:
self.destination = destination
self.attached_interface = None
self.__remote_identity = None
self._channel = None
if self.destination == None:
self.initiator = False
self.prv = X25519PrivateKey.generate()
@ -462,6 +464,8 @@ class Link:
resource.cancel()
for resource in self.outgoing_resources:
resource.cancel()
if self._channel:
self._channel._shutdown()
self.prv = None
self.pub = None
@ -642,6 +646,16 @@ class Link:
if pending_request.request_id == resource.request_id:
pending_request.request_timed_out(None)
def get_channel(self):
"""
Get the ``Channel`` for this link.
:return: ``Channel`` object
"""
if self._channel is None:
self._channel = Channel(LinkChannelOutlet(self))
return self._channel
def receive(self, packet):
self.watchdog_lock = True
if not self.status == Link.CLOSED and not (self.initiator and packet.context == RNS.Packet.KEEPALIVE and packet.data == bytes([0xFF])):
@ -788,6 +802,14 @@ class Link:
for resource in self.incoming_resources:
resource.receive_part(packet)
elif packet.context == RNS.Packet.CHANNEL:
if not self._channel:
RNS.log(f"Channel data received without open channel", RNS.LOG_DEBUG)
else:
plaintext = self.decrypt(packet.data)
self._channel._receive(plaintext)
packet.prove()
elif packet.packet_type == RNS.Packet.PROOF:
if packet.context == RNS.Packet.RESOURCE_PRF:
resource_hash = packet.data[0:RNS.Identity.HASHLENGTH//8]

1
RNS/Packet.py
View File

@ -75,6 +75,7 @@ class Packet:
PATH_RESPONSE = 0x0B # Packet is a response to a path request
COMMAND = 0x0C # Packet is a command
COMMAND_STATUS = 0x0D # Packet is a status of an executed command
CHANNEL = 0x0E # Packet contains link channel data
KEEPALIVE = 0xFA # Packet is a keepalive packet
LINKIDENTIFY = 0xFB # Packet is a link peer identification proof
LINKCLOSE = 0xFC # Packet is a link close message

1
RNS/__init__.py
View File

@ -32,6 +32,7 @@ from ._version import __version__
from .Reticulum import Reticulum
from .Identity import Identity
from .Link import Link, RequestReceipt
from .Channel import MessageBase
from .Transport import Transport
from .Destination import Destination
from .Packet import Packet

12
docs/source/examples.rst
View File

@ -92,6 +92,18 @@ The *Request* example explores sendig requests and receiving responses.
This example can also be found at `<https://github.com/markqvist/Reticulum/blob/master/Examples/Request.py>`_.
.. _example-channel:
Channel
====
The *Channel* example explores using a ``Channel`` to send structured
data between peers of a ``Link``.
.. literalinclude:: ../../Examples/Channel.py
This example can also be found at `<https://github.com/markqvist/Reticulum/blob/master/Examples/Channel.py>`_.
.. _example-filetransfer:
Filetransfer

28
docs/source/reference.rst
View File

@ -121,6 +121,34 @@ This chapter lists and explains all classes exposed by the Reticulum Network Sta
.. autoclass:: RNS.Resource(data, link, advertise=True, auto_compress=True, callback=None, progress_callback=None, timeout=None)
:members:
.. _api-channel:
.. only:: html
|start-h3| Channel |end-h3|
.. only:: latex
Channel
------
.. autoclass:: RNS.Channel.Channel()
:members:
.. _api-messsagebase:
.. only:: html
|start-h3| MessageBase |end-h3|
.. only:: latex
MessageBase
------
.. autoclass:: RNS.MessageBase()
:members:
.. _api-transport:
.. only:: html

1
tests/all.py
View File

@ -4,6 +4,7 @@ from .hashes import TestSHA256
from .hashes import TestSHA512
from .identity import TestIdentity
from .link import TestLink
from .channel import TestChannel
if __name__ == '__main__':
unittest.main(verbosity=2)

375
tests/channel.py Normal file
View File

@ -0,0 +1,375 @@
from __future__ import annotations
import threading
import RNS
from RNS.Channel import MessageState, ChannelOutletBase, Channel, MessageBase
from RNS.vendor import umsgpack
from typing import Callable
import contextlib
import typing
import types
import time
import uuid
import unittest
class Packet:
timeout = 1.0
def __init__(self, raw: bytes):
self.state = MessageState.MSGSTATE_NEW
self.raw = raw
self.packet_id = uuid.uuid4()
self.tries = 0
self.timeout_id = None
self.lock = threading.RLock()
self.instances = 0
self.timeout_callback: Callable[[Packet], None] | None = None
self.delivered_callback: Callable[[Packet], None] | None = None
def set_timeout(self, callback: Callable[[Packet], None] | None, timeout: float):
with self.lock:
if timeout is not None:
self.timeout = timeout
self.timeout_callback = callback
def send(self):
self.tries += 1
self.state = MessageState.MSGSTATE_SENT
def elapsed(timeout: float, timeout_id: uuid.uuid4):
with self.lock:
self.instances += 1
try:
time.sleep(timeout)
with self.lock:
if self.timeout_id == timeout_id:
self.timeout_id = None
self.state = MessageState.MSGSTATE_FAILED
if self.timeout_callback:
self.timeout_callback(self)
finally:
with self.lock:
self.instances -= 1
self.timeout_id = uuid.uuid4()
threading.Thread(target=elapsed, name="Packet Timeout", args=[self.timeout, self.timeout_id],
daemon=True).start()
def clear_timeout(self):
self.timeout_id = None
def set_delivered_callback(self, callback: Callable[[Packet], None]):
self.delivered_callback = callback
def delivered(self):
with self.lock:
self.state = MessageState.MSGSTATE_DELIVERED
self.timeout_id = None
if self.delivered_callback:
self.delivered_callback(self)
class ChannelOutletTest(ChannelOutletBase):
def get_packet_state(self, packet: Packet) -> MessageState:
return packet.state
def set_packet_timeout_callback(self, packet: Packet, callback: Callable[[Packet], None] | None,
timeout: float | None = None):
packet.set_timeout(callback, timeout)
def set_packet_delivered_callback(self, packet: Packet, callback: Callable[[Packet], None] | None):
packet.set_delivered_callback(callback)
def get_packet_id(self, packet: Packet) -> any:
return packet.packet_id
def __init__(self, mdu: int, rtt: float):
self.link_id = uuid.uuid4()
self.timeout_callbacks = 0
self._mdu = mdu
self._rtt = rtt
self._usable = True
self.packets = []
self.packet_callback: Callable[[ChannelOutletBase, bytes], None] | None = None
def send(self, raw: bytes) -> Packet:
packet = Packet(raw)
packet.send()
self.packets.append(packet)
return packet
def resend(self, packet: Packet) -> Packet:
packet.send()
return packet
@property
def mdu(self):
return self._mdu
@property
def rtt(self):
return self._rtt
@property
def is_usable(self):
return self._usable
def timed_out(self):
self.timeout_callbacks += 1
def __str__(self):
return str(self.link_id)
class MessageTest(MessageBase):
MSGTYPE = 0xabcd
def __init__(self):
self.id = str(uuid.uuid4())
self.data = "test"
self.not_serialized = str(uuid.uuid4())
def pack(self) -> bytes:
return umsgpack.packb((self.id, self.data))
def unpack(self, raw):
self.id, self.data = umsgpack.unpackb(raw)
class SystemMessage(MessageBase):
MSGTYPE = 0xf000
def pack(self) -> bytes:
return bytes()
def unpack(self, raw):
pass
class ProtocolHarness(contextlib.AbstractContextManager):
def __init__(self, rtt: float):
self.outlet = ChannelOutletTest(mdu=500, rtt=rtt)
self.channel = Channel(self.outlet)
def cleanup(self):
self.channel._shutdown()
def __exit__(self, __exc_type: typing.Type[BaseException], __exc_value: BaseException,
__traceback: types.TracebackType) -> bool:
# self._log.debug(f"__exit__({__exc_type}, {__exc_value}, {__traceback})")
self.cleanup()
return False
class TestChannel(unittest.TestCase):
def setUp(self) -> None:
print("")
self.rtt = 0.001
self.retry_interval = self.rtt * 150
Packet.timeout = self.retry_interval
self.h = ProtocolHarness(self.rtt)
def tearDown(self) -> None:
self.h.cleanup()
def test_send_one_retry(self):
print("Channel test one retry")
message = MessageTest()
self.assertEqual(0, len(self.h.outlet.packets))
envelope = self.h.channel.send(message)
self.assertIsNotNone(envelope)
self.assertIsNotNone(envelope.raw)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertIsNotNone(envelope.packet)
self.assertTrue(envelope in self.h.channel._tx_ring)
self.assertTrue(envelope.tracked)
packet = self.h.outlet.packets[0]
self.assertEqual(envelope.packet, packet)
self.assertEqual(1, envelope.tries)
self.assertEqual(1, packet.tries)
self.assertEqual(1, packet.instances)
self.assertEqual(MessageState.MSGSTATE_SENT, packet.state)
self.assertEqual(envelope.raw, packet.raw)
time.sleep(self.retry_interval * 1.5)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertEqual(2, envelope.tries)
self.assertEqual(2, packet.tries)
self.assertEqual(1, packet.instances)
time.sleep(self.retry_interval)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertEqual(self.h.outlet.packets[0], packet)
self.assertEqual(3, envelope.tries)
self.assertEqual(3, packet.tries)
self.assertEqual(1, packet.instances)
self.assertEqual(MessageState.MSGSTATE_SENT, packet.state)
packet.delivered()
self.assertEqual(MessageState.MSGSTATE_DELIVERED, packet.state)
time.sleep(self.retry_interval)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertEqual(3, envelope.tries)
self.assertEqual(3, packet.tries)
self.assertEqual(0, packet.instances)
self.assertFalse(envelope.tracked)
def test_send_timeout(self):
print("Channel test retry count exceeded")
message = MessageTest()
self.assertEqual(0, len(self.h.outlet.packets))
envelope = self.h.channel.send(message)
self.assertIsNotNone(envelope)
self.assertIsNotNone(envelope.raw)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertIsNotNone(envelope.packet)
self.assertTrue(envelope in self.h.channel._tx_ring)
self.assertTrue(envelope.tracked)
packet = self.h.outlet.packets[0]
self.assertEqual(envelope.packet, packet)
self.assertEqual(1, envelope.tries)
self.assertEqual(1, packet.tries)
self.assertEqual(1, packet.instances)
self.assertEqual(MessageState.MSGSTATE_SENT, packet.state)
self.assertEqual(envelope.raw, packet.raw)
time.sleep(self.retry_interval * 7.5)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertEqual(5, envelope.tries)
self.assertEqual(5, packet.tries)
self.assertEqual(0, packet.instances)
self.assertEqual(MessageState.MSGSTATE_FAILED, packet.state)
self.assertFalse(envelope.tracked)
def test_multiple_handler(self):
print("Channel test multiple handler short circuit")
handler1_called = 0
handler1_return = True
handler2_called = 0
def handler1(msg: MessageBase):
nonlocal handler1_called, handler1_return
self.assertIsInstance(msg, MessageTest)
handler1_called += 1
return handler1_return
def handler2(msg: MessageBase):
nonlocal handler2_called
self.assertIsInstance(msg, MessageTest)
handler2_called += 1
message = MessageTest()
self.h.channel.register_message_type(MessageTest)
self.h.channel.add_message_handler(handler1)
self.h.channel.add_message_handler(handler2)
envelope = RNS.Channel.Envelope(self.h.outlet, message, sequence=0)
raw = envelope.pack()
self.h.channel._receive(raw)
self.assertEqual(1, handler1_called)
self.assertEqual(0, handler2_called)
handler1_return = False
envelope = RNS.Channel.Envelope(self.h.outlet, message, sequence=1)
raw = envelope.pack()
self.h.channel._receive(raw)
self.assertEqual(2, handler1_called)
self.assertEqual(1, handler2_called)
def test_system_message_check(self):
print("Channel test register system message")
with self.assertRaises(RNS.Channel.ChannelException):
self.h.channel.register_message_type(SystemMessage)
self.h.channel._register_message_type(SystemMessage, is_system_type=True)
def eat_own_dog_food(self, message: MessageBase, checker: typing.Callable[[MessageBase], None]):
decoded: [MessageBase] = []
def handle_message(message: MessageBase):
decoded.append(message)
self.h.channel.register_message_type(message.__class__)
self.h.channel.add_message_handler(handle_message)
self.assertEqual(len(self.h.outlet.packets), 0)
envelope = self.h.channel.send(message)
time.sleep(self.retry_interval * 0.5)
self.assertIsNotNone(envelope)
self.assertIsNotNone(envelope.raw)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertIsNotNone(envelope.packet)
self.assertTrue(envelope in self.h.channel._tx_ring)
self.assertTrue(envelope.tracked)
packet = self.h.outlet.packets[0]
self.assertEqual(envelope.packet, packet)
self.assertEqual(1, envelope.tries)
self.assertEqual(1, packet.tries)
self.assertEqual(1, packet.instances)
self.assertEqual(MessageState.MSGSTATE_SENT, packet.state)
self.assertEqual(envelope.raw, packet.raw)
packet.delivered()
self.assertEqual(MessageState.MSGSTATE_DELIVERED, packet.state)
time.sleep(self.retry_interval * 2)
self.assertEqual(1, len(self.h.outlet.packets))
self.assertEqual(1, envelope.tries)
self.assertEqual(1, packet.tries)
self.assertEqual(0, packet.instances)
self.assertFalse(envelope.tracked)
self.assertEqual(len(self.h.outlet.packets), 1)
self.assertEqual(MessageState.MSGSTATE_DELIVERED, packet.state)
self.assertFalse(envelope.tracked)
self.assertEqual(0, len(decoded))
self.h.channel._receive(packet.raw)
self.assertEqual(1, len(decoded))
rx_message = decoded[0]
self.assertIsNotNone(rx_message)
self.assertIsInstance(rx_message, message.__class__)
checker(rx_message)
def test_send_receive_message_test(self):
print("Channel test send and receive message")
message = MessageTest()
def check(rx_message: MessageBase):
self.assertIsInstance(rx_message, message.__class__)
self.assertEqual(message.id, rx_message.id)
self.assertEqual(message.data, rx_message.data)
self.assertNotEqual(message.not_serialized, rx_message.not_serialized)
self.eat_own_dog_food(message, check)
if __name__ == '__main__':
unittest.main(verbosity=2)

57
tests/link.py
View File

@ -6,6 +6,8 @@ import threading
import time
import RNS
import os
from tests.channel import MessageTest
from RNS.Channel import MessageBase
APP_NAME = "rns_unit_tests"
@ -346,6 +348,54 @@ class TestLink(unittest.TestCase):
time.sleep(0.5)
self.assertEqual(l1.status, RNS.Link.CLOSED)
def test_10_channel_round_trip(self):
global c_rns
init_rns(self)
print("")
print("Channel round trip test")
# TODO: Load this from public bytes only
id1 = RNS.Identity.from_bytes(bytes.fromhex(fixed_keys[0][0]))
self.assertEqual(id1.hash, bytes.fromhex(fixed_keys[0][1]))
dest = RNS.Destination(id1, RNS.Destination.OUT, RNS.Destination.SINGLE, APP_NAME, "link", "establish")
self.assertEqual(dest.hash, bytes.fromhex("fb48da0e82e6e01ba0c014513f74540d"))
l1 = RNS.Link(dest)
time.sleep(1)
self.assertEqual(l1.status, RNS.Link.ACTIVE)
received = []
def handle_message(message: MessageBase):
received.append(message)
test_message = MessageTest()
test_message.data = "Hello"
channel = l1.get_channel()
channel.register_message_type(MessageTest)
channel.add_message_handler(handle_message)
channel.send(test_message)
time.sleep(0.5)
self.assertEqual(1, len(received))
rx_message = received[0]
self.assertIsInstance(rx_message, MessageTest)
self.assertEqual("Hello back", rx_message.data)
self.assertEqual(test_message.id, rx_message.id)
self.assertNotEqual(test_message.not_serialized, rx_message.not_serialized)
self.assertEqual(1, len(l1._channel._rx_ring))
l1.teardown()
time.sleep(0.5)
self.assertEqual(l1.status, RNS.Link.CLOSED)
self.assertEqual(0, len(l1._channel._rx_ring))
def size_str(self, num, suffix='B'):
units = ['','K','M','G','T','P','E','Z']
@ -404,6 +454,13 @@ def targets(yp=False):
link.set_resource_strategy(RNS.Link.ACCEPT_ALL)
link.set_resource_started_callback(resource_started)
link.set_resource_concluded_callback(resource_concluded)
channel = link.get_channel()
def handle_message(message):
message.data = message.data + " back"
channel.send(message)
channel.register_message_type(MessageTest)
channel.add_message_handler(handle_message)
m_rns = RNS.Reticulum("./tests/rnsconfig")
id1 = RNS.Identity.from_bytes(bytes.fromhex(fixed_keys[0][0]))