Metadata-Version: 2.1
Name: aioax25
Version: 0.0.10
Summary: Asynchronous AX.25 interface in pure Python using asyncio
Home-page: https://github.com/sjlongland/aioax25/
Author: Stuart Longland VK4MSL
Author-email: me@vk4msl.id.au
License: GPL-2.0-or-later
Description: # `aioax25`: AX.25 and APRS library in `asyncio`
        
        [![Build Status](https://travis-ci.org/sjlongland/aioax25.svg?branch=master)](https://travis-ci.org/sjlongland/aioax25)
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        The aim of this project is to implement a simple-to-understand asynchronous
        AX.25 library built on `asyncio` and `pyserial`, implementing a AX.25 and APRS
        stack in pure Python.
        
        ## What works
        
        * We can put a Kantronics KPC-3 TNC into KISS mode automatically
        * Multi-port KISS TNCs (tested with
          [Direwolf](https://github.com/wb2osz/direwolf) and the
          [NWDR UDRC-II](https://nw-digital-radio.groups.io/g/udrc/wiki/home))
        * We can receive AX.25 UI frames
        * We can send AX.25 UI frames
        
        ## What doesn't work
        
        * Connecting to AX.25 nodes
        * Accepting connections from AX.25 nodes
        
        ## What isn't tested
        
        * Platforms other than GNU/Linux
        
        ## Current plans
        
        Right now, I intend to get enough going for APRS operation, as that is my
        immediate need now.  Hence the focus on UI frames.
        
        I intend to write a core class that will take care of some core AX.25 message
        handling work and provide the basis of what's needed to implement APRS.
        
        After that, some things I'd like to tackle in no particular order:
        
        * Connected mode operation
        * NET/ROM support
        
        Supported platforms will be GNU/Linux, and possibly BSD variants.  I don't
        have access to recent Apple hardware (my 2008-era MacBook will not run
        contemporary MacOS X) so I'm unable to test this software there, but it
        _should_ work nonetheless.
        
        It might work on Windows -- most probably using Cygwin or Subsystem for Linux.
        While I do have a Windows 7 machine handy, life's too short to muck around
        with an OS that can't decide if it's pretending to be Linux, VMS or CP/M.
        There's an abundance of AX.25 stacks and tools for that platform, I'll accept
        patches here on the proviso they don't break things or make the code
        unmaintainable.
        
        ## Usage
        
        This is a rough guide regarding how to use `aioax25` in your programs.
        
        ### Create a KISS device interface and ports
        
        Right now we only support serial KISS interfaces (patches for TCP-based
        interfaces are welcome).  Import `SerialKISSDevice` from `aioax25.kiss`, then
        create an instance as shown:
        
        ```python
            kissdev = SerialKISSDevice(
                device='/dev/ttyS4', baudrate=9600,
                log=logging.getLogger('your.kiss.log')
            )
        ```
        
        Some optional parameters:
         * `reset_on_close`: When asked to close the device, try to issue a `c0 ff c0`
           reset sequence to the TNC to put it back into CMD mode.
         * `send_block_size`, `send_block_delay`: If a KISS frame is larger than
           this size, break the transmissions out the serial port into chunks of
           the given size, and wait `send_block_delay` seconds between each chunk.
           (If your TNC has a small buffer, this may help.)
        
        This represents the KISS TNC itself, with its ports accessible using the usual
        `__getitem__` syntax:
        
        ```python
            kissport0 = kissdev[0]
            kissport1 = kissdev[1]
        ```
        
        These KISS port interfaces just spit out the content of raw AX.25 frames via
        their `received` signals and accept raw AX.25 frames via the `send` method.
        Any object passed to `send` is wrapped in a `bytes` call -- this will
        implicitly call the `__bytes__` method on the object you pass in.
        
        ### Setting up an AX.25 Interface
        
        The AX.25 interface is a logical routing and queueing layer which decodes the
        data received from a KISS port and routes it according to the destination
        call-sign.
        
        `AX25Interface` is found in the `aioax25.interface` package.  Import that, then
        do the following to set up your interface:
        
        ```python
           ax25int = AX25Interface(
               kissport=kissdev[0],     # or whatever port number you need
               log=logging.getLogger('your.ax25.log')
           )
        ```
        
        Some optional parameters:
         * `cts_delay`, `cts_rand`: The number of seconds to wait after making a
           transmission/receiving a transmission, before we send another transmission.
           The delay time is `cts_delay + (random.random() * cts_rand)`, the idea
           being to avoid doubling when two stations attempt transmission.
        
        The `AX25Interface` is a subclass of `Router` (see `aioax25.router`), which
        exposes the following methods and properties:
        
         * `received_msg`: This is a `Signal` object which is fired for every AX.25
           frame received.  Slots are expected to take two keyword arguments:
           `interface` (the interface that received the frame) and `frame` (the
           AX.25 frame itself).
        
         * `bind(callback, callsign, ssid=0, regex=False)`: This method allows you to
           bind a call-back function to receive AX.25 frames whose `destination` field
           is addressed to the call-sign and SSID specified.  The call-sign may be a
           regular expression if `regex=True`.  This will be compiled and matched
           against all incoming traffic.  Regardless of the value of `regex`, the
           `callsign` parameter _must_ be a string.
        
         * `unbind(callback, callsign, ssid=0, regex=False)`: This method un-binds a
           previously bound call-back method from receiving the nominated traffic.
        
        Additionally, for transmitting frames, `AX25Interface` adds the following:
        
         * `transmit(frame, callback=None)`: This method allows you to transmit
           arbitrary AX.25 frames.  They are assumed to be instances of `AX25Frame`
           (from `aioax25.frame`).  The `callback`, if given, will be called once the
           frame is sent with the following keyword arguments: `interface` (the
           `AX25Interface` that sent the frame), `frame` (the frame that was sent).
        
         * `cancel_transmit(frame)`: This cancels a pending transmission of a frame.
           If the frame has been sent, this has no effect.
        
        ## APRS Traffic handling
        
        The `AX25Interface` just deals in AX.25 traffic, and does not provide any
        special handling of APRS UI frames.  For this, one may look at `APRSInterface`.
        
        Import this from `aioax25.aprs`.  It too, is a subclass of `Router`, and so
        `bind`, `unbind` and `received_msg` are there -- the messages received will
        be instances of `APRSFrame` (see `aioax25.aprs.frame`), otherwise the behaviour
        is identical.
        
        ```python
           aprsint = APRSInterface(
               ax25int=ax25int,         # Your AX25Interface object
               mycall='VK4MSL-9',       # Your call-sign and SSID
               log=logging.getLogger('your.aprs.log')
           )
        ```
        
        Other optional parameters:
         * `retransmit_count`, `retransmit_timeout_base`, `retransmit_timeout_rand`,
           `retransmit_timeout_scale`: These control the timing of retransmissions
           when sending _confirmable_ APRS messages.  Before transmission, a time-out
           is computed as `timeout = retransmit_timeout_base + (random.random() *
           retransmit_timeout_rand)`, and a retry counter is initialised to
           `retransmit_count`.  On each re-transmission, the retry counter is
           decremented and the timeout is multiplied by `retransmit_timeout_scale`.
         * `aprs_destination`: This sets the destination call-sign used for APRS
           traffic.  Right now, we use the experimental call of `APZAIO` for all
           traffic except direct messages (which instead are sent directly to the
           station addressed).
         * `aprs_path` specifies the digipeater path to use when sending APRS traffic.
         * `listen_destinations` is a list of AX.25 destinations.  Behind the scenes,
           these are values passed to `Router.bind`, and thus are given as `dict`s of
           the form: `{callsign: "CALL", regex: True/False, ssid: None/int}`.
         * `listen_altnets` is an additional list of AX.25 destinations, given using
           the same scheme as `listen_destinations`.
         * `msgid_modulo` sets the modulo value used when generating a message ID.
           The default value (1000) results in a message ID that starts at 1 and wraps
           around at 999.
         * `deduplication_expiry` sets the number of seconds we store message hashes
           for de-duplication purposes.  The default is 28 seconds.
        
        To send APRS messages, there is `send_message` and `send_response`:
        
         * `send_message(addressee, path=None, oneshot=False, replyack=False)`:
           This sends an APRS message to the addressed station.  If `path` is `None`,
           then the `aprs_path` is used.  If `oneshot=True`, then the message is sent
           without a message ID, no ACK/REJ is expected and no retransmissions will be
           made, the method returns `None`.  Otherwise, a `APRSMessageHandler` (from
           `aioax25.aprs.message`) is returned.
           * If `replyack` is set to `True`, then the message will advertise
             [reply-ack](http://www.aprs.org/aprs11/replyacks.txt) capability to
             the recipient.  Not all APRS implementations support this.
           * If `replyack` references an incoming message which itself has `replyack`
             set (either to `True` or to a previous message ID), then the outgoing
             message will have a reply-ack suffix appended to "ack" the given message.
           * The default of `replyack=False` disables all reply-ack capability (an
             incoming reply-ack message will still be treated as an ACK however).
         * `send_response(message, ack=True)`: This is used when you have received
           a message from another station -- passing that message to this function
           will send a `ACK` or `REJ` message to that station.
        
        ### The `APRSMessageHandler` class
        
        The `APRSMessageHandler` class implements the APRS message retransmission
        logic.  The objects have a `done` signal which is emitted upon any of the
        following events:
        
         * Message time-out (no ACK/REJ received) (`state=HandlerState.TIMEOUT`)
         * Message was cancelled (via the `cancel()` method)
           (`state=HandlerState.CANCEL`)
         * An ACK or REJ frame was received (`state=HandlerState.SUCCESS` or
           `state=HandlerState.REJECT`)
        
        The signal will call call-back functions with the following keyword arguments:
         * `handler`: The `APRSMessageHandler` object emitting the signal
         * `state`: The state of the `APRSMessageHandler` object.
        
        ### APRS Digipeating
        
        `aioax25` includes a module that implements basic digipeating for APRS
        including handling of the `WIDEn-N` SSIDs.  The implementation treats `WIDE`
        like `TRACE`: inserting the station's own call-sign in the path (which I
        believe is more compliant with the [Amateur License Conditions
        Determination](https://www.legislation.gov.au/Details/F2016C00286) in that it
        ensures each digipeater "identifies" itself).
        
        The `aioax25.aprs.uidigi` module can be configured to digipeat for other
        aliases such as the legacy `WIDE` and `RELAY`, or any alias of your choosing.
        
        It is capable of handling multiple interfaces, but will repeat incoming
        messages on the interface they were received from *ONLY*.  (i.e. if you connect
        a 2m interface and a HF interface, it will *NOT* digipeat from HF to 2m).
        
        Set-up is pretty simple:
        
        ```
        from aioax25.aprs.uidigi import APRSDigipeater
        
        # Given an APRSInterface class (aprsint)
        # Create a digipeater instance
        digipeater = APRSDigipeater()
        
        # Connect your interface
        digipeater.connect(aprsint)
        
        # Optionally add any aliases you want handled
        digipeater.addaliases('WIDE', 'GATE')
        ```
        
        You're now digipeating.  The digipeater will automatically handle `WIDEn-N` and
        `TRACEn-N`, and in the above example, will also digipeat for `WIDE`, `GATE`.
        
        #### Preventing message loops on busy networks
        
        If you have a *lot* of digipeaters in close proximity (say about 6) and there's
        a lot of traffic, you can get the situation where a message queued up to be
        digipeated sits in the transmit queue longer than the 28 seconds needed for
        other digipeaters to "forget" the message.
        
        This leads to a network with the memory of an elephant, it almost never forgets
        a message because the digipeats come more than 30 seconds *after* the original.
        
        The `APRSDigipeater` class constructor can take a single parameter,
        `digipeater_timeout`, which sets an expiry (default of 5 seconds) on queued
        digipeat messages.  If a message is not sent by the time this timeout expires,
        the message is quietly dropped, preventing the memory effect.
        
Platform: UNKNOWN
Classifier: Development Status :: 2 - Pre-Alpha
Classifier: Environment :: No Input/Output (Daemon)
Classifier: Framework :: AsyncIO
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)
Classifier: Operating System :: POSIX
Classifier: Programming Language :: Python :: 3 :: Only
Classifier: Topic :: Communications :: Ham Radio
Requires: pyserial
Requires: signalslot
Description-Content-Type: text/markdown
