Reticulum/RNS/Interfaces/I2PInterface.py

# MIT License
#
# Copyright (c) 2016-2022 Mark Qvist / unsigned.io
#
# 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 .Interface import Interface
import socketserver
import threading
import platform
import socket
import time
import sys
import os
import RNS
import asyncio

class HDLC():
    FLAG              = 0x7E
    ESC               = 0x7D
    ESC_MASK          = 0x20

    @staticmethod
    def escape(data):
        data = data.replace(bytes([HDLC.ESC]), bytes([HDLC.ESC, HDLC.ESC^HDLC.ESC_MASK]))
        data = data.replace(bytes([HDLC.FLAG]), bytes([HDLC.ESC, HDLC.FLAG^HDLC.ESC_MASK]))
        return data

class KISS():
    FEND              = 0xC0
    FESC              = 0xDB
    TFEND             = 0xDC
    TFESC             = 0xDD
    CMD_DATA          = 0x00
    CMD_UNKNOWN       = 0xFE

    @staticmethod
    def escape(data):
        data = data.replace(bytes([0xdb]), bytes([0xdb, 0xdd]))
        data = data.replace(bytes([0xc0]), bytes([0xdb, 0xdc]))
        return data

# TODO: Neater shutdown of the event loop and
# better error handling is needed. Sometimes
# errors occur in I2P that leave tunnel setup
# hanging indefinitely, and right now we have
# no way of catching it. Sometimes the server
# and client tasks are also not cancelled on
# shutdown, which leads to errors dumped to
# the console. This should also be remedied.

class I2PController:
    def __init__(self, rns_storagepath):
        import RNS.vendor.i2plib as i2plib
        import RNS.vendor.i2plib.utils

        self.client_tunnels = {}
        self.server_tunnels = {}
        self.i2plib_tunnels = {}
        self.loop = None
        self.i2plib = i2plib
        self.utils = i2plib.utils
        self.sam_address = i2plib.get_sam_address()
        self.ready = False

        self.storagepath = rns_storagepath+"/i2p"
        if not os.path.isdir(self.storagepath):
            os.makedirs(self.storagepath)


    def start(self):
        asyncio.set_event_loop(asyncio.new_event_loop())
        self.loop = asyncio.get_event_loop()

        time.sleep(0.10)
        if self.loop == None:
            RNS.log(f"Could not get event loop for {self}, waiting for event loop to appear", RNS.LOG_VERBOSE)

        while self.loop == None:
            self.loop = asyncio.get_event_loop()
            sleep(0.25)

        try:
            self.ready = True
            self.loop.run_forever()
        except Exception as e:
            self.ready = False
            RNS.log(f"Exception on event loop for {self}: {e}", RNS.LOG_ERROR)
        finally:
            self.loop.close()


    def stop(self):
        for i2ptunnel in self.i2plib_tunnels:
            if hasattr(i2ptunnel, "stop") and callable(i2ptunnel.stop):
                i2ptunnel.stop()

        if hasattr(asyncio.Task, "all_tasks") and callable(asyncio.Task.all_tasks):
            for task in asyncio.Task.all_tasks(loop=self.loop):
                task.cancel()

        time.sleep(0.2)

        self.loop.stop()


    def get_free_port(self):
        return self.i2plib.utils.get_free_port()


    def stop_tunnel(self, i2ptunnel):
        if hasattr(i2ptunnel, "stop") and callable(i2ptunnel.stop):
            i2ptunnel.stop()

    def client_tunnel(self, owner, i2p_destination):
        self.client_tunnels[i2p_destination] = False
        self.i2plib_tunnels[i2p_destination] = None

        while True:
            if not self.client_tunnels[i2p_destination]:
                try:
                    async def tunnel_up():
                        RNS.log(f"Bringing up I2P tunnel to {owner}, this may take a while...", RNS.LOG_INFO)
                        tunnel = self.i2plib.ClientTunnel(i2p_destination, owner.local_addr, sam_address=self.sam_address, loop=self.loop)
                        self.i2plib_tunnels[i2p_destination] = tunnel
                        await tunnel.run()

                    self.loop.ext_owner = self
                    result = asyncio.run_coroutine_threadsafe(tunnel_up(), self.loop).result()

                    if not i2p_destination in self.i2plib_tunnels:
                        raise OSError("No tunnel control instance was created")

                    else:
                        tn = self.i2plib_tunnels[i2p_destination]
                        if tn != None and hasattr(tn, "status"):

                            RNS.log("Waiting for status from I2P control process", RNS.LOG_EXTREME)
                            while not tn.status["setup_ran"]:
                                time.sleep(0.1)
                            RNS.log("Got status from I2P control process", RNS.LOG_EXTREME)

                            if tn.status["setup_failed"]:
                                self.stop_tunnel(tn)
                                raise tn.status["exception"]

                            else:
                                if owner.socket != None:
                                    if hasattr(owner.socket, "close"):
                                        if callable(owner.socket.close):
                                            try:
                                                owner.socket.shutdown(socket.SHUT_RDWR)
                                            except Exception as e:
                                                RNS.log(f"Error while shutting down socket for {owner}: {e}")

                                            try:
                                                owner.socket.close()
                                            except Exception as e:
                                                RNS.log(f"Error while closing socket for {owner}: {e}")
                                self.client_tunnels[i2p_destination] = True
                                owner.awaiting_i2p_tunnel = False

                                RNS.log(f"{owner} tunnel setup complete", RNS.LOG_VERBOSE)

                        else:
                            raise OSError("Got no status response from SAM API")

                except ConnectionRefusedError as e:
                    raise e

                except ConnectionAbortedError as e:
                    raise e

                except Exception as e:
                    RNS.log(f"Unexpected error type from I2P SAM: {e}", RNS.LOG_ERROR)
                    raise e

            else:
                i2ptunnel = self.i2plib_tunnels[i2p_destination]
                if hasattr(i2ptunnel, "status"):
                    i2p_exception = i2ptunnel.status["exception"]

                    if i2ptunnel.status["setup_ran"] == False:
                        RNS.log(f"{self} I2P tunnel setup did not complete", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                    elif i2p_exception != None:
                        RNS.log(f"An error ocurred while setting up I2P tunnel to {i2p_destination}", RNS.LOG_ERROR)

                        if isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.CantReachPeer):
                            RNS.log(f"The I2P daemon can't reach peer {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.DuplicatedDest):
                            RNS.log("The I2P daemon reported that the destination is already in use", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.DuplicatedId):
                            RNS.log("The I2P daemon reported that the ID is arleady in use", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.InvalidId):
                            RNS.log("The I2P daemon reported that the stream session ID doesn't exist", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.InvalidKey):
                            RNS.log(f"The I2P daemon reported that the key for {i2p_destination} is invalid", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.KeyNotFound):
                            RNS.log(f"The I2P daemon could not find the key for {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.PeerNotFound):
                            RNS.log(f"The I2P daemon mould not find the peer {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.I2PError):
                            RNS.log("The I2P daemon experienced an unspecified error", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.Timeout):
                            RNS.log(f"I2P daemon timed out while setting up client tunnel to {i2p_destination}", RNS.LOG_ERROR)

                        RNS.log("Resetting I2P tunnel and retrying later", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                    elif i2ptunnel.status["setup_failed"] == True:
                        RNS.log(f"{self} Unspecified I2P tunnel setup error, resetting I2P tunnel", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                else:
                    RNS.log(f"{self} Got no status from SAM API, resetting I2P tunnel", RNS.LOG_ERROR)

                    self.stop_tunnel(i2ptunnel)
                    return False

            # Wait for status from I2P control process
            time.sleep(5)


    def server_tunnel(self, owner):
        while RNS.Transport.identity == None:
            time.sleep(1)

        # Old format
        i2p_dest_hash_of = RNS.Identity.full_hash(RNS.Identity.full_hash(owner.name.encode("utf-8")))
        i2p_keyfile_of   = f"{self.storagepath}/{RNS.hexrep(i2p_dest_hash_of, delimit=False)}.i2p"

        # New format
        i2p_dest_hash_nf = RNS.Identity.full_hash(RNS.Identity.full_hash(owner.name.encode("utf-8"))+RNS.Identity.full_hash(RNS.Transport.identity.hash))
        i2p_keyfile_nf   = f"{self.storagepath}/{RNS.hexrep(i2p_dest_hash_nf, delimit=False)}.i2p"

        # Use old format if a key is already present
        if os.path.isfile(i2p_keyfile_of):
            i2p_keyfile = i2p_keyfile_of
        else:
            i2p_keyfile = i2p_keyfile_nf

        i2p_dest = None
        if not os.path.isfile(i2p_keyfile):
            coro = self.i2plib.new_destination(sam_address=self.sam_address, loop=self.loop)
            i2p_dest = asyncio.run_coroutine_threadsafe(coro, self.loop).result()
            key_file = open(i2p_keyfile, "w")
            key_file.write(i2p_dest.private_key.base64)
            key_file.close()
        else:
            key_file = open(i2p_keyfile)
            prvd = key_file.read()
            key_file.close()
            i2p_dest = self.i2plib.Destination(data=prvd, has_private_key=True)

        i2p_b32 = i2p_dest.base32
        owner.b32 = i2p_b32

        self.server_tunnels[i2p_b32] = False
        self.i2plib_tunnels[i2p_b32] = None

        while True:
            if self.server_tunnels[i2p_b32] == False:
                try:
                    async def tunnel_up():
                        RNS.log(f"{owner} Bringing up I2P endpoint, this may take a while...", RNS.LOG_INFO)
                        tunnel = self.i2plib.ServerTunnel((owner.bind_ip, owner.bind_port), loop=self.loop, destination=i2p_dest, sam_address=self.sam_address)
                        self.i2plib_tunnels[i2p_b32] = tunnel
                        await tunnel.run()
                        owner.online = True
                        RNS.log(f"{owner} endpoint setup complete. Now reachable at: {i2p_dest.base32}.b32.i2p", RNS.LOG_VERBOSE)

                    asyncio.run_coroutine_threadsafe(tunnel_up(), self.loop).result()
                    self.server_tunnels[i2p_b32] = True

                except Exception as e:
                    raise e

            else:
                i2ptunnel = self.i2plib_tunnels[i2p_b32]
                if hasattr(i2ptunnel, "status"):
                    i2p_exception = i2ptunnel.status["exception"]

                    if i2ptunnel.status["setup_ran"] == False:
                        RNS.log(f"{self} I2P tunnel setup did not complete", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                    elif i2p_exception != None:
                        RNS.log("An error ocurred while setting up I2P tunnel", RNS.LOG_ERROR)

                        if isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.CantReachPeer):
                            RNS.log(f"The I2P daemon can't reach peer {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.DuplicatedDest):
                            RNS.log("The I2P daemon reported that the destination is already in use", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.DuplicatedId):
                            RNS.log("The I2P daemon reported that the ID is arleady in use", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.InvalidId):
                            RNS.log("The I2P daemon reported that the stream session ID doesn't exist", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.InvalidKey):
                            RNS.log(f"The I2P daemon reported that the key for {i2p_destination} is invalid", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.KeyNotFound):
                            RNS.log(f"The I2P daemon could not find the key for {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.PeerNotFound):
                            RNS.log(f"The I2P daemon mould not find the peer {i2p_destination}", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.I2PError):
                            RNS.log("The I2P daemon experienced an unspecified error", RNS.LOG_ERROR)

                        elif isinstance(i2p_exception, RNS.vendor.i2plib.exceptions.Timeout):
                            RNS.log(f"I2P daemon timed out while setting up client tunnel to {i2p_destination}", RNS.LOG_ERROR)

                        RNS.log("Resetting I2P tunnel and retrying later", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                    elif i2ptunnel.status["setup_failed"] == True:
                        RNS.log(f"{self} Unspecified I2P tunnel setup error, resetting I2P tunnel", RNS.LOG_ERROR)

                        self.stop_tunnel(i2ptunnel)
                        return False

                else:
                    RNS.log(f"{self} Got no status from SAM API, resetting I2P tunnel", RNS.LOG_ERROR)

                    self.stop_tunnel(i2ptunnel)
                    return False

            time.sleep(5)

    def get_loop(self):
        return asyncio.get_event_loop()


class ThreadingI2PServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    pass

class I2PInterfacePeer(Interface):
    RECONNECT_WAIT = 15
    RECONNECT_MAX_TRIES = None

    # TCP socket options
    I2P_USER_TIMEOUT = 45
    I2P_PROBE_AFTER = 10
    I2P_PROBE_INTERVAL = 9
    I2P_PROBES = 5
    I2P_READ_TIMEOUT = (I2P_PROBE_INTERVAL * I2P_PROBES + I2P_PROBE_AFTER)*2

    TUNNEL_STATE_INIT    = 0x00
    TUNNEL_STATE_ACTIVE  = 0x01
    TUNNEL_STATE_STALE   = 0x02

    def __init__(self, parent_interface, owner, name, target_i2p_dest=None, connected_socket=None, max_reconnect_tries=None):
        super().__init__()

        self.HW_MTU = 1064

        self.IN               = True
        self.OUT              = False
        self.socket           = None
        self.parent_interface = parent_interface
        self.parent_count     = True
        self.name             = name
        self.initiator        = False
        self.reconnecting     = False
        self.never_connected  = True
        self.owner            = owner
        self.writing          = False
        self.online           = False
        self.detached         = False
        self.kiss_framing     = False
        self.i2p_tunneled     = True
        self.i2p_dest         = None
        self.i2p_tunnel_ready = False
        self.mode             = RNS.Interfaces.Interface.Interface.MODE_FULL
        self.bitrate          = I2PInterface.BITRATE_GUESS
        self.last_read        = 0
        self.last_write       = 0
        self.wd_reset         = False
        self.i2p_tunnel_state = I2PInterfacePeer.TUNNEL_STATE_INIT

        self.ifac_size = self.parent_interface.ifac_size
        self.ifac_netname = self.parent_interface.ifac_netname
        self.ifac_netkey = self.parent_interface.ifac_netkey
        if self.ifac_netname != None or self.ifac_netkey != None:
            ifac_origin = b""
            if self.ifac_netname != None:
                ifac_origin += RNS.Identity.full_hash(self.ifac_netname.encode("utf-8"))
            if self.ifac_netkey != None:
                ifac_origin += RNS.Identity.full_hash(self.ifac_netkey.encode("utf-8"))

            ifac_origin_hash = RNS.Identity.full_hash(ifac_origin)
            self.ifac_key = RNS.Cryptography.hkdf(
                length=64,
                derive_from=ifac_origin_hash,
                salt=RNS.Reticulum.IFAC_SALT,
                context=None
            )
            self.ifac_identity = RNS.Identity.from_bytes(self.ifac_key)
            self.ifac_signature = self.ifac_identity.sign(RNS.Identity.full_hash(self.ifac_key))

        self.announce_rate_target  = None
        self.announce_rate_grace   = None
        self.announce_rate_penalty = None

        if max_reconnect_tries == None:
            self.max_reconnect_tries = I2PInterfacePeer.RECONNECT_MAX_TRIES
        else:
            self.max_reconnect_tries = max_reconnect_tries

        if connected_socket != None:
            self.receives    = True
            self.target_ip   = None
            self.target_port = None
            self.socket      = connected_socket

            if platform.system() == "Linux":
                self.set_timeouts_linux()
            elif platform.system() == "Darwin":
                self.set_timeouts_osx()

        elif target_i2p_dest != None:
            self.receives    = True
            self.initiator   = True

            self.bind_ip     = "127.0.0.1"

            self.awaiting_i2p_tunnel = True

            def tunnel_job():
                while self.awaiting_i2p_tunnel:
                    try:
                        self.bind_port   = self.parent_interface.i2p.get_free_port()
                        self.local_addr  = (self.bind_ip, self.bind_port)
                        self.target_ip = self.bind_ip
                        self.target_port = self.bind_port

                        if not self.parent_interface.i2p.client_tunnel(self, target_i2p_dest):
                            RNS.log(f"{self} I2P control process experienced an error, requesting new tunnel...", RNS.LOG_ERROR)
                            self.awaiting_i2p_tunnel = True

                    except Exception as e:
                        RNS.log(f"Error while while configuring {self}: {e}", RNS.LOG_ERROR)
                        RNS.log("Check that I2P is installed and running, and that SAM is enabled. Retrying tunnel setup later.", RNS.LOG_ERROR)

                    time.sleep(8)

            thread = threading.Thread(target=tunnel_job)
            thread.daemon = True
            thread.start()

            def wait_job():
                while self.awaiting_i2p_tunnel:
                    time.sleep(0.25)
                time.sleep(2)

                if not self.kiss_framing:
                    self.wants_tunnel = True

                if not self.connect(initial=True):
                    thread = threading.Thread(target=self.reconnect)
                    thread.daemon = True
                    thread.start()
                else:
                    thread = threading.Thread(target=self.read_loop)
                    thread.daemon = True
                    thread.start()

            thread = threading.Thread(target=wait_job)
            thread.daemon = True
            thread.start()


    def set_timeouts_linux(self):
        self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_USER_TIMEOUT, int(I2PInterfacePeer.I2P_USER_TIMEOUT * 1000))
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
        self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, int(I2PInterfacePeer.I2P_PROBE_AFTER))
        self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, int(I2PInterfacePeer.I2P_PROBE_INTERVAL))
        self.socket.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, int(I2PInterfacePeer.I2P_PROBES))

    def set_timeouts_osx(self):
        if hasattr(socket, "TCP_KEEPALIVE"):
            TCP_KEEPIDLE = socket.TCP_KEEPALIVE
        else:
            TCP_KEEPIDLE = 0x10

        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
        self.socket.setsockopt(socket.IPPROTO_TCP, TCP_KEEPIDLE, int(I2PInterfacePeer.I2P_PROBE_AFTER))

    def shutdown_socket(self, target_socket):
        if callable(target_socket.close):
            try:
                if socket != None:
                    target_socket.shutdown(socket.SHUT_RDWR)
            except Exception as e:
                RNS.log(f"Error while shutting down socket for {self}: {e}")

            try:
                if socket != None:
                    target_socket.close()
            except Exception as e:
                RNS.log(f"Error while closing socket for {self}: {e}")

    def detach(self):
        RNS.log(f"Detaching {self}", RNS.LOG_DEBUG)
        if self.socket != None:
            if hasattr(self.socket, "close"):
                if callable(self.socket.close):
                    self.detached = True

                    try:
                        self.socket.shutdown(socket.SHUT_RDWR)
                    except Exception as e:
                        RNS.log(f"Error while shutting down socket for {self}: {e}")

                    try:
                        self.socket.close()
                    except Exception as e:
                        RNS.log(f"Error while closing socket for {self}: {e}")

                    self.socket = None

    def connect(self, initial=False):
        try:
            self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
            self.socket.connect((self.target_ip, self.target_port))
            self.online  = True

        except Exception as e:
            if initial:
                if not self.awaiting_i2p_tunnel:
                    RNS.log(f"Initial connection for {self} could not be established: {e}", RNS.LOG_ERROR)
                    RNS.log(f"Leaving unconnected and retrying connection in {I2PInterfacePeer.RECONNECT_WAIT} seconds.", RNS.LOG_ERROR)

                return False

            else:
                raise e

        if platform.system() == "Linux":
            self.set_timeouts_linux()
        elif platform.system() == "Darwin":
            self.set_timeouts_osx()

        self.online  = True
        self.writing = False
        self.never_connected = False

        if not self.kiss_framing and self.wants_tunnel:
            RNS.Transport.synthesize_tunnel(self)

        return True

    def reconnect(self):
        if self.initiator:
            if not self.reconnecting:
                self.reconnecting = True
                attempts = 0
                while not self.online:
                    time.sleep(I2PInterfacePeer.RECONNECT_WAIT)
                    attempts += 1

                    if self.max_reconnect_tries != None and attempts > self.max_reconnect_tries:
                        RNS.log(f"Max reconnection attempts reached for {self}", RNS.LOG_ERROR)
                        self.teardown()
                        break

                    try:
                        self.connect()

                    except Exception as e:
                        if not self.awaiting_i2p_tunnel:
                            RNS.log(f"Connection attempt for {self} failed: {e}", RNS.LOG_DEBUG)
                        else:
                            RNS.log(f"{self} still waiting for I2P tunnel to appear", RNS.LOG_VERBOSE)

                if not self.never_connected:
                    RNS.log(f"{self} Re-established connection via I2P tunnel", RNS.LOG_INFO)

                self.reconnecting = False
                thread = threading.Thread(target=self.read_loop)
                thread.daemon = True
                thread.start()
                if not self.kiss_framing:
                    RNS.Transport.synthesize_tunnel(self)

        else:
            RNS.log("Attempt to reconnect on a non-initiator I2P interface. This should not happen.", RNS.LOG_ERROR)
            raise OSError("Attempt to reconnect on a non-initiator I2P interface")

    def processIncoming(self, data):
        self.rxb += len(data)
        if hasattr(self, "parent_interface") and self.parent_interface != None and self.parent_count:
            self.parent_interface.rxb += len(data)

        self.owner.inbound(data, self)

    def processOutgoing(self, data):
        if self.online:
            while self.writing:
                time.sleep(0.001)

            try:
                self.writing = True

                if self.kiss_framing:
                    data = bytes([KISS.FEND])+bytes([KISS.CMD_DATA])+KISS.escape(data)+bytes([KISS.FEND])
                else:
                    data = bytes([HDLC.FLAG])+HDLC.escape(data)+bytes([HDLC.FLAG])

                self.socket.sendall(data)
                self.writing = False
                self.txb += len(data)
                self.last_write = time.time()

                if hasattr(self, "parent_interface") and self.parent_interface != None and self.parent_count:
                    self.parent_interface.txb += len(data)

            except Exception as e:
                RNS.log(f"Exception occurred while transmitting via {self}, tearing down interface", RNS.LOG_ERROR)
                RNS.log(f"The contained exception was: {e}", RNS.LOG_ERROR)
                self.teardown()


    def read_watchdog(self):
        while self.wd_reset:
            time.sleep(0.25)

        should_run = True
        try:
            while should_run and not self.wd_reset:
                time.sleep(1)

                if (time.time()-self.last_read > I2PInterfacePeer.I2P_PROBE_AFTER*2):
                    if self.i2p_tunnel_state != I2PInterfacePeer.TUNNEL_STATE_STALE:
                        RNS.log("I2P tunnel became unresponsive", RNS.LOG_DEBUG)

                    self.i2p_tunnel_state = I2PInterfacePeer.TUNNEL_STATE_STALE
                else:
                    self.i2p_tunnel_state = I2PInterfacePeer.TUNNEL_STATE_ACTIVE

                if (time.time()-self.last_write > I2PInterfacePeer.I2P_PROBE_AFTER*1):
                    try:
                        if self.socket != None:
                            self.socket.sendall(bytes([HDLC.FLAG, HDLC.FLAG]))
                    except Exception as e:
                        RNS.log(f"An error ocurred while sending I2P keepalive. The contained exception was: {e}", RNS.LOG_ERROR)
                        self.shutdown_socket(self.socket)
                        should_run = False

                if (time.time()-self.last_read > I2PInterfacePeer.I2P_READ_TIMEOUT):
                    RNS.log("I2P socket is unresponsive, restarting...", RNS.LOG_WARNING)
                    if self.socket != None:
                        try:
                            self.socket.shutdown(socket.SHUT_RDWR)
                        except Exception as e:
                            RNS.log(f"Error while shutting down socket for {self}: {e}")

                        try:
                            self.socket.close()
                        except Exception as e:
                            RNS.log(f"Error while closing socket for {self}: {e}")

                    should_run = False

                self.wd_reset = False

        finally:
            self.wd_reset = False

    def read_loop(self):
        try:
            self.last_read  = time.time()
            self.last_write = time.time()

            wd_thread = threading.Thread(target=self.read_watchdog, daemon=True).start()

            in_frame = False
            escape = False
            data_buffer = b""
            command = KISS.CMD_UNKNOWN

            while True:
                data_in = self.socket.recv(4096)
                if len(data_in) > 0:
                    pointer = 0
                    self.last_read = time.time()
                    while pointer < len(data_in):
                        byte = data_in[pointer]
                        pointer += 1

                        if self.kiss_framing:
                            # Read loop for KISS framing
                            if (in_frame and byte == KISS.FEND and command == KISS.CMD_DATA):
                                in_frame = False
                                self.processIncoming(data_buffer)
                            elif (byte == KISS.FEND):
                                in_frame = True
                                command = KISS.CMD_UNKNOWN
                                data_buffer = b""
                            elif (in_frame and len(data_buffer) < self.HW_MTU):
                                if (len(data_buffer) == 0 and command == KISS.CMD_UNKNOWN):
                                    # We only support one HDLC port for now, so
                                    # strip off the port nibble
                                    byte = byte & 0x0F
                                    command = byte
                                elif (command == KISS.CMD_DATA):
                                    if (byte == KISS.FESC):
                                        escape = True
                                    else:
                                        if (escape):
                                            if (byte == KISS.TFEND):
                                                byte = KISS.FEND
                                            if (byte == KISS.TFESC):
                                                byte = KISS.FESC
                                            escape = False
                                        data_buffer = data_buffer+bytes([byte])

                        else:
                            # Read loop for HDLC framing
                            if (in_frame and byte == HDLC.FLAG):
                                in_frame = False
                                self.processIncoming(data_buffer)
                            elif (byte == HDLC.FLAG):
                                in_frame = True
                                data_buffer = b""
                            elif (in_frame and len(data_buffer) < self.HW_MTU):
                                if (byte == HDLC.ESC):
                                    escape = True
                                else:
                                    if (escape):
                                        if (byte == HDLC.FLAG ^ HDLC.ESC_MASK):
                                            byte = HDLC.FLAG
                                        if (byte == HDLC.ESC  ^ HDLC.ESC_MASK):
                                            byte = HDLC.ESC
                                        escape = False
                                    data_buffer = data_buffer+bytes([byte])
                else:
                    self.online = False

                    self.wd_reset = True
                    time.sleep(2)
                    self.wd_reset = False

                    if self.initiator and not self.detached:
                        RNS.log(f"Socket for {self} was closed, attempting to reconnect...", RNS.LOG_WARNING)
                        self.reconnect()
                    else:
                        RNS.log(f"Socket for remote client {self} was closed.", RNS.LOG_VERBOSE)
                        self.teardown()

                    break


        except Exception as e:
            self.online = False
            RNS.log(f"An interface error occurred for {self}, the contained exception was: {e}", RNS.LOG_WARNING)

            if self.initiator:
                RNS.log("Attempting to reconnect...", RNS.LOG_WARNING)
                self.reconnect()
            else:
                self.teardown()

    def teardown(self):
        if self.initiator and not self.detached:
            RNS.log(f"The interface {self} experienced an unrecoverable error and is being torn down. Restart Reticulum to attempt to open this interface again.", RNS.LOG_ERROR)
            if RNS.Reticulum.panic_on_interface_error:
                RNS.panic()

        else:
            RNS.log(f"The interface {self} is being torn down.", RNS.LOG_VERBOSE)

        self.online = False
        self.OUT = False
        self.IN = False

        if hasattr(self, "parent_interface") and self.parent_interface != None:
            if self.parent_interface.clients > 0:
                self.parent_interface.clients -= 1

        if self in RNS.Transport.interfaces:
            if not self.initiator:
                RNS.Transport.interfaces.remove(self)


    def __str__(self):
        return f"I2PInterfacePeer[{self.name}]"


class I2PInterface(Interface):
    BITRATE_GUESS      = 256*1000

    def __init__(self, owner, name, rns_storagepath, peers, connectable = False, ifac_size = 16, ifac_netname = None, ifac_netkey = None):
        super().__init__()

        self.HW_MTU = 1064

        self.online = False
        self.clients = 0
        self.owner = owner
        self.connectable = connectable
        self.i2p_tunneled = True
        self.mode = RNS.Interfaces.Interface.Interface.MODE_FULL

        self.b32 = None
        self.i2p = I2PController(rns_storagepath)

        self.IN  = True
        self.OUT = False
        self.name = name


        self.receives = True
        self.bind_ip     = "127.0.0.1"
        self.bind_port   = self.i2p.get_free_port()
        self.address = (self.bind_ip, self.bind_port)
        self.bitrate = I2PInterface.BITRATE_GUESS
        self.ifac_size = ifac_size
        self.ifac_netname = ifac_netname
        self.ifac_netkey = ifac_netkey

        self.online = False

        i2p_thread = threading.Thread(target=self.i2p.start)
        i2p_thread.daemon = True
        i2p_thread.start()

        i2p_notready_warning = False
        time.sleep(0.25)

        if not self.i2p.ready:
            RNS.log("I2P controller did not become available in time, waiting for controller", RNS.LOG_VERBOSE)
            i2p_notready_warning = True

        while not self.i2p.ready:
            time.sleep(0.25)

        if i2p_notready_warning == True:
            RNS.log("I2P controller ready, continuing setup", RNS.LOG_VERBOSE)

        def handlerFactory(callback):
            def createHandler(*args, **keys):
                return I2PInterfaceHandler(callback, *args, **keys)
            return createHandler

        ThreadingI2PServer.allow_reuse_address = True
        self.server = ThreadingI2PServer(self.address, handlerFactory(self.incoming_connection))

        thread = threading.Thread(target=self.server.serve_forever)
        thread.daemon = True
        thread.start()

        if self.connectable:
            def tunnel_job():
                while True:
                    try:
                        if not self.i2p.server_tunnel(self):
                            RNS.log(f"{self} I2P control process experienced an error, requesting new tunnel...", RNS.LOG_ERROR)
                            self.online = False

                    except Exception as e:
                        RNS.log(f"Error while while configuring {self}: {e}", RNS.LOG_ERROR)
                        RNS.log("Check that I2P is installed and running, and that SAM is enabled. Retrying tunnel setup later.", RNS.LOG_ERROR)

                    time.sleep(15)


            thread = threading.Thread(target=tunnel_job)
            thread.daemon = True
            thread.start()

        if peers != None:
            for peer_addr in peers:
                interface_name = f"{self.name} to {peer_addr}"
                peer_interface = I2PInterfacePeer(self, self.owner, interface_name, peer_addr)
                peer_interface.OUT = True
                peer_interface.IN  = True
                peer_interface.parent_interface = self
                peer_interface.parent_count = False
                RNS.Transport.interfaces.append(peer_interface)

    def incoming_connection(self, handler):
        RNS.log("Accepting incoming I2P connection", RNS.LOG_VERBOSE)
        interface_name = f"Connected peer on {self.name}"
        spawned_interface = I2PInterfacePeer(self, self.owner, interface_name, connected_socket=handler.request)
        spawned_interface.OUT = True
        spawned_interface.IN  = True
        spawned_interface.parent_interface = self
        spawned_interface.online = True
        spawned_interface.bitrate = self.bitrate

        spawned_interface.ifac_size = self.ifac_size
        spawned_interface.ifac_netname = self.ifac_netname
        spawned_interface.ifac_netkey = self.ifac_netkey
        if spawned_interface.ifac_netname != None or spawned_interface.ifac_netkey != None:
            ifac_origin = b""
            if spawned_interface.ifac_netname != None:
                ifac_origin += RNS.Identity.full_hash(spawned_interface.ifac_netname.encode("utf-8"))
            if spawned_interface.ifac_netkey != None:
                ifac_origin += RNS.Identity.full_hash(spawned_interface.ifac_netkey.encode("utf-8"))

            ifac_origin_hash = RNS.Identity.full_hash(ifac_origin)
            spawned_interface.ifac_key = RNS.Cryptography.hkdf(
                length=64,
                derive_from=ifac_origin_hash,
                salt=RNS.Reticulum.IFAC_SALT,
                context=None
            )
            spawned_interface.ifac_identity = RNS.Identity.from_bytes(spawned_interface.ifac_key)
            spawned_interface.ifac_signature = spawned_interface.ifac_identity.sign(RNS.Identity.full_hash(spawned_interface.ifac_key))

        spawned_interface.announce_rate_target = self.announce_rate_target
        spawned_interface.announce_rate_grace = self.announce_rate_grace
        spawned_interface.announce_rate_penalty = self.announce_rate_penalty
        spawned_interface.mode = self.mode
        spawned_interface.HW_MTU = self.HW_MTU
        RNS.log(f"Spawned new I2PInterface Peer: {spawned_interface}", RNS.LOG_VERBOSE)
        RNS.Transport.interfaces.append(spawned_interface)
        self.clients += 1
        spawned_interface.read_loop()

    def processOutgoing(self, data):
        pass

    def received_announce(self, from_spawned=False):
        if from_spawned: self.ia_freq_deque.append(time.time())

    def sent_announce(self, from_spawned=False):
        if from_spawned: self.oa_freq_deque.append(time.time())

    def detach(self):
        RNS.log(f"Detaching {self}", RNS.LOG_DEBUG)
        self.i2p.stop()

    def __str__(self):
        return f"I2PInterface[{self.name}]"

class I2PInterfaceHandler(socketserver.BaseRequestHandler):
    def __init__(self, callback, *args, **keys):
        self.callback = callback
        socketserver.BaseRequestHandler.__init__(self, *args, **keys)

    def handle(self):
        self.callback(handler=self)