AX25Stack

java.lang.Object
- org.ka2ddo.ax25.AX25Stack

All Implemented Interfaces:

java.lang.Runnable, FrameListener, DebugCtl.DbgListener
```
public class AX25Stack
extends java.lang.Object
implements FrameListener, java.lang.Runnable, DebugCtl.DbgListener
```
This class implements the internal AX.25 (v2.2) protocol stack for a TNC (layer 2), as defined in the AX.25 Link Access Protocol for Amateur Packet Radio specification. It does not implement the level 7 applications or any layer 3 protocols.

Author:

Andrew Pavlin, KA2DDO

Field Summary

Fields
Modifier and Type Field and Description

static int WAIT_FOR_ACK_T1_TIMER
Time interval (in milliseconds) to wait for an acknowledgement from the other end of a AX.25 connection.

Fields
Modifier and Type	Field and Description
`static int`	`WAIT_FOR_ACK_T1_TIMER` Time interval (in milliseconds) to wait for an acknowledgement from the other end of a AX.25 connection.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addAX25FrameListener(AX25FrameListener l)` Add a listener for incoming AX.25 frames.
`static void`	`addConnStateChangeListener(ConnStateChangeListener l)` Register a listener to be informed when AX.25 connected-mode session state changes.
`void`	`addParsedAX25MessageListener(ParsedAX25MessageListener listener)` Register an ParsedAX25MessageListener to be notified of incoming parsed level 3 protocol messages (other than APRS).
`void`	`consumeFrame(AX25Frame frame)` Queue one AX.25 frame (containing some sort of message) for parsing and processing.
`void`	`consumeFrameNow(Connector connector, AX25Frame frame)` Process an incoming AX.25 frame.
`static AX25Callsign[]`	`dupUnuseDigipeaters(AX25Callsign[] srcRelays)` Create a duplicate digipeater list from a source packet, but ensure all the has-been-repeated flags are cleared.
`void`	`fireConsumeAX25Frame(AX25Frame frame, Connector connector)` Send the specified incoming frame to all registered AX25FrameListeners.
`java.util.Map<AX25Callsign,java.util.Map<AX25Callsign,ConnState>>`	`getConnectionMap()` Get the map of all outstanding I-frame connected sessions observed by or end-pointed at this station.
`ConnectionRequestListener`	`getConnectionRequestListener()` Test if a plugin has already set the ConnectionRequestListener.
`static ConnState`	`getConnState(AX25Callsign src, AX25Callsign dst, boolean createIfNotPresent)` Get the connection state of an I-frame connection session between the specified two callsigns, optionally creating the state object if it did not previously exist.
`int`	`getCurrentBacklog()` Return the current number of backlogged frames to be processed by the AX25Stack thread.
`static java.lang.String[]`	`getDigipeaters()` Get the default list of digipeaters for this stack.
`static AX25Stack`	`getInstance()` Get a handle to the AX25Stack singleton.
`int`	`getMaxBacklog()` Return the maximum backlog ever incurred by the AX25Stack parser thread.
`int`	`getMaxQueueCapacity()` Return the maximum allowed size of the queue.
`int`	`getNumConsumedMsgs()` Return the number of AX.25 messages consumed by the AX25Stack.
`AX25Parser`	`getParser(byte pid)` Get the protocol parsing handler for the specified protocol.
`static ReschedulableTimer`	`getRetransTimer()` Get the retransmit timer for outbound AX.25 frames.
`static ConnState.ConnType`	`getStateOf(AX25Callsign src, AX25Callsign dst)` Get the connection state of an I-frame connection session between the specified two callsigns.
`static java.lang.String`	`getToCall()` Get the destination callsign (tocall) that should be used for messages originated by this station.
`static Transmitting`	`getTransmitting()` Get the Transmitting object that this AX25Stack will use for implicit but unrouted transmissions.
`static boolean`	`isAllowInboundConnectedMode()` Indicate whether this system accepts inbound connected-mode connection requests.
`boolean`	`isFrozen()` Report if parser thread is frozen.
`static boolean`	`isLocalDest(AX25Callsign dest)` Test if this callsign is addressed to the local station.
`static boolean`	`isLocalDest(java.lang.String destCallsign)` Test if this callsign is addressed to the local station.
`boolean`	`processIBody(AX25Frame frame, boolean isUI, Connector connector, long rcvTimestamp)` This method consumes one information frame.
`void`	`processParsedAX25Message(AX25Frame frame, AX25Message parsedMsg)` Dispatch an AX.25 frame that was parsed into a higher-level protocol to all registered listeners.
`void`	`registerProtocolParser(byte pid, AX25Parser parser)` Register another protocol parsing handler for a particular AX.25 UI/I message PID.
`void`	`removeAX25FrameListener(AX25FrameListener l)` Remove a listener for incoming AX.25 frames.
`static void`	`removeConnState(ConnState connState)` Remove the specified ConnState object from the map of ConnState maps.
`static void`	`removeConnStateChangeListener(ConnStateChangeListener l)` Unregister a listener to be informed when AX.25 connected-mode session state changes.
`void`	`removeParsedAX25MessageListener(ParsedAX25MessageListener listener)` Unregister an ParsedAX25MessageListener to be notified of incoming parsed level 3 protocol messages (other than APRS).
`static AX25Callsign[]`	`reverseDigipeaters(AX25Callsign[] srcRelays)` Reverse the order of a sequence of digipeaters (explicit and APRS aliases).
`void`	`run()` Private method to asynchronously consume AX25Frame objects for parsing.
`static void`	`setAllowInboundConnectedMode(boolean allowInboundConnects)` Specify whether this system accepts inbound connected-mode connection requests.
`void`	`setConnectionRequestListener(ConnectionRequestListener l)` Set the handler for inbound connection requests.
`void`	`setDebug(java.lang.String categoryName, boolean setting)` Specify if a specific category of debug messages should be printed out.
`static void`	`setDigipeaters(java.lang.String[] digipeaters)` Set the default list of digipeaters for this stack.
`void`	`setFrozen(boolean frozen)` Specify whether the AX.25 parser thread should be paused (frozen) to allow the user to view the output without it moving constantly
`static void`	`setToCall(java.lang.String toCall)` Set the destination callsign (tocall) that should be used for messages originated by this station.
`static void`	`setTransmitting(Transmitting transmitting)` Set the Transmitting object that this AX25Stack will use for implicit but unrouted transmissions.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - WAIT_FOR_ACK_T1_TIMER
```
public static final int WAIT_FOR_ACK_T1_TIMER
```
    Time interval (in milliseconds) to wait for an acknowledgement from the other end of a AX.25 connection.
    
    See Also:
    
    Constant Field Values
- Method Detail
  - getInstance
```
public static AX25Stack getInstance()
```
    Get a handle to the AX25Stack singleton.
    
    Returns:
    
    AX25Stack instance
  - getDigipeaters
```
public static java.lang.String[] getDigipeaters()
```
    Get the default list of digipeaters for this stack.
    
    Returns:
    
    array of String digipeater aliases supported by this stack
  - setDigipeaters
```
public static void setDigipeaters(java.lang.String[] digipeaters)
```
    Set the default list of digipeaters for this stack.
    
    Parameters:
    
    digipeaters - array of String digipeater aliases
  - getToCall
```
public static java.lang.String getToCall()
```
    Get the destination callsign (tocall) that should be used for messages originated by this station.
    
    Returns:
    
    destination callsign (tocall)
  - setToCall
```
public static void setToCall(java.lang.String toCall)
```
    Set the destination callsign (tocall) that should be used for messages originated by this station.
    
    Parameters:
    
    toCall - destination callsign (tocall)
  - setDebug
```
public void setDebug(java.lang.String categoryName,
                     boolean setting)
```
    Specify if a specific category of debug messages should be printed out.
    
    Specified by:
    
    setDebug in interface DebugCtl.DbgListener
    
    Parameters:
    
    categoryName - String name of category to enable debug logging for
    
    setting - boolean true or false to enable or disable debugging this category
  - getTransmitting
```
public static Transmitting getTransmitting()
```
    Get the Transmitting object that this AX25Stack will use for implicit but unrouted transmissions.
    
    Returns:
    
    Transmitting object
  - setTransmitting
```
public static void setTransmitting(Transmitting transmitting)
```
    Set the Transmitting object that this AX25Stack will use for implicit but unrouted transmissions.
    
    Parameters:
    
    transmitting - Transmitting object
  - getRetransTimer
```
public static ReschedulableTimer getRetransTimer()
```
    Get the retransmit timer for outbound AX.25 frames.
    
    Returns:
    
    ReschedulableTimer
  - isAllowInboundConnectedMode
```
public static boolean isAllowInboundConnectedMode()
```
    Indicate whether this system accepts inbound connected-mode connection requests.
    
    Returns:
    
    boolean true if inbound connection requests should be accepted
  - setAllowInboundConnectedMode
```
public static void setAllowInboundConnectedMode(boolean allowInboundConnects)
```
    Specify whether this system accepts inbound connected-mode connection requests.
    
    Parameters:
    
    allowInboundConnects - boolean true if inbound connection requests should be accepted
  - addAX25FrameListener
```
public void addAX25FrameListener(AX25FrameListener l)
```
    Add a listener for incoming AX.25 frames.
    
    Parameters:
    
    l - AX25FrameListener to register
  - removeAX25FrameListener
```
public void removeAX25FrameListener(AX25FrameListener l)
```
    Remove a listener for incoming AX.25 frames.
    
    Parameters:
    
    l - AX25FrameListener to unregister
  - getConnectionRequestListener
```
public ConnectionRequestListener getConnectionRequestListener()
```
    Test if a plugin has already set the ConnectionRequestListener.
    
    Returns:
    
    the ConnectionRequestListener set on thw AX25Stack, or null if not set
    
    Since:
    
    PROVIDER_API_VERSION == 50
  - setConnectionRequestListener
```
public void setConnectionRequestListener(ConnectionRequestListener l)
```
    Set the handler for inbound connection requests.
    
    Parameters:
    
    l - ConnectionRequestListener to register
  - registerProtocolParser
```
public void registerProtocolParser(byte pid,
                                   AX25Parser parser)
```
    Register another protocol parsing handler for a particular AX.25 UI/I message PID.
    
    Parameters:
    
    pid - pid byte code for this protocol
    
    parser - AX25Parser to handle receiving this protocol
  - getParser
```
public AX25Parser getParser(byte pid)
```
    Get the protocol parsing handler for the specified protocol.
    
    Parameters:
    
    pid - level 3 protocol ID byte (as defined by the AX.25 protocol specification)
    
    Returns:
    
    AX25Parser object, or null if no parser registered for the specified protocol
  - fireConsumeAX25Frame
```
public void fireConsumeAX25Frame(AX25Frame frame,
                                 Connector connector)
```
    Send the specified incoming frame to all registered AX25FrameListeners.
    
    Parameters:
    
    frame - AX25Frame to dispatch
    
    connector - Connector that received the frame
  - consumeFrame
```
public void consumeFrame(AX25Frame frame)
```
    Queue one AX.25 frame (containing some sort of message) for parsing and processing.
    
    Specified by:
    
    consumeFrame in interface FrameListener
    
    Parameters:
    
    frame - the AX25Frame to be processed
  - getCurrentBacklog
```
public int getCurrentBacklog()
```
    Return the current number of backlogged frames to be processed by the AX25Stack thread.
    
    Returns:
    
    current queue size
  - getMaxBacklog
```
public int getMaxBacklog()
```
    Return the maximum backlog ever incurred by the AX25Stack parser thread.
    
    Returns:
    
    maximum queue backlog
  - getMaxQueueCapacity
```
public int getMaxQueueCapacity()
```
    Return the maximum allowed size of the queue.
    
    Returns:
    
    total capacity of the backlog queue
  - getNumConsumedMsgs
```
public int getNumConsumedMsgs()
```
    Return the number of AX.25 messages consumed by the AX25Stack.
    
    Returns:
    
    count of messages consumed
  - run
```
public void run()
```
    Private method to asynchronously consume AX25Frame objects for parsing. This tries to prevent back-pressuring any sources (particularly fast-moving TCP connections to APRS-IS servers). Can only be executed from the singleton thread created by this class.
    
    Specified by:
    
    run in interface java.lang.Runnable
  - isFrozen
```
public boolean isFrozen()
```
    Report if parser thread is frozen.
    
    Returns:
    
    boolean true if parser thread is stopped
  - setFrozen
```
public void setFrozen(boolean frozen)
```
    Specify whether the AX.25 parser thread should be paused (frozen) to allow the user to view the output without it moving constantly
    
    Parameters:
    
    frozen - boolean true to freeze the parser thread, or false to resume execution
  - consumeFrameNow
```
public void consumeFrameNow(Connector connector,
                            AX25Frame frame)
```
    Process an incoming AX.25 frame.
    
    Parameters:
    
    connector - Connector that received the frame
    
    frame - AX25Frame to process
  - getConnectionMap
```
public java.util.Map<AX25Callsign,java.util.Map<AX25Callsign,ConnState>> getConnectionMap()
```
    Get the map of all outstanding I-frame connected sessions observed by or end-pointed at this station.
    
    Returns:
    
    Map by initiating callsign of Maps by destination callsign of connection states
  - getStateOf
```
public static ConnState.ConnType getStateOf(AX25Callsign src,
                                            AX25Callsign dst)
```
    Get the connection state of an I-frame connection session between the specified two callsigns.
    
    Parameters:
    
    src - AX25Callsign of originating end of session
    
    dst - AX25Callsign of receiving end of session
    
    Returns:
    
    ConnType of the session, or ConnType.NONE if there is no such connection session known to this protocol stack
  - getConnState
```
public static ConnState getConnState(AX25Callsign src,
                                     AX25Callsign dst,
                                     boolean createIfNotPresent)
```
    Get the connection state of an I-frame connection session between the specified two callsigns, optionally creating the state object if it did not previously exist.
    
    Parameters:
    
    src - AX25Callsign of originating end of session
    
    dst - AX25Callsign of receiving end of session
    
    createIfNotPresent - boolean true if a new ConnState object should be created and registered if it does not already exist
    
    Returns:
    
    ConnState object for the requested session, or null if no such session exists and the caller did not request creating one
  - removeConnState
```
public static void removeConnState(ConnState connState)
```
    Remove the specified ConnState object from the map of ConnState maps. Usually done when a connection is closed.
    
    Parameters:
    
    connState - ConnState object to remove from map
  - dupUnuseDigipeaters
```
public static AX25Callsign[] dupUnuseDigipeaters(AX25Callsign[] srcRelays)
```
    Create a duplicate digipeater list from a source packet, but ensure all the has-been-repeated flags are cleared.
    
    Parameters:
    
    srcRelays - array of digipeater callsign-SSID's to clone, or null if none
    
    Returns:
    
    array of duplicated AX25Callsigns with all has-been-repeated flags cleared, or null if the source array was null or empty
  - reverseDigipeaters
```
public static AX25Callsign[] reverseDigipeaters(AX25Callsign[] srcRelays)
```
    Reverse the order of a sequence of digipeaters (explicit and APRS aliases).
    
    Parameters:
    
    srcRelays - array of AX25Callsign indicating the path used to get from sender to recipient
    
    Returns:
    
    array of AX25Callsigns needed to go from recipient back to sender
  - processIBody
```
public boolean processIBody(AX25Frame frame,
                            boolean isUI,
                            Connector connector,
                            long rcvTimestamp)
```
    This method consumes one information frame. The caller handles any flow control issues for I (versus UI) frames.
    
    Parameters:
    
    frame - AX25Frame to be decoded
    
    isUI - where frame was received in a UI AX.25 frame instead of an I frame
    
    connector - PortConnector over which message arrived, or null for file playback
    
    rcvTimestamp - time (in Java-standard milliseconds since Jan 1 1970 UTC) that message was received
    
    Returns:
    
    boolean true if message has already been reported to listeners
  - processParsedAX25Message
```
public void processParsedAX25Message(AX25Frame frame,
                                     AX25Message parsedMsg)
```
    Dispatch an AX.25 frame that was parsed into a higher-level protocol to all registered listeners.
    
    Parameters:
    
    frame - AX25Frame of incoming message
    
    parsedMsg - AX25Message subclass containing protocol decoding of message
  - addParsedAX25MessageListener
```
public void addParsedAX25MessageListener(ParsedAX25MessageListener listener)
```
    Register an ParsedAX25MessageListener to be notified of incoming parsed level 3 protocol messages (other than APRS).
    
    Parameters:
    
    listener - ParsedAX25MessageListener to register
  - removeParsedAX25MessageListener
```
public void removeParsedAX25MessageListener(ParsedAX25MessageListener listener)
```
    Unregister an ParsedAX25MessageListener to be notified of incoming parsed level 3 protocol messages (other than APRS).
    
    Parameters:
    
    listener - ParsedAX25MessageListener to unregister
  - isLocalDest
```
public static boolean isLocalDest(AX25Callsign dest)
```
    Test if this callsign is addressed to the local station.
    
    Parameters:
    
    dest - AX25Callsign to test as a destination
    
    Returns:
    
    boolean true if this callsign is for the local station
  - isLocalDest
```
public static boolean isLocalDest(java.lang.String destCallsign)
```
    Test if this callsign is addressed to the local station.
    
    Parameters:
    
    destCallsign - String of AX.25 callsign-SSID to test as a destination
    
    Returns:
    
    boolean true if this callsign is for the local station
  - addConnStateChangeListener
```
public static void addConnStateChangeListener(ConnStateChangeListener l)
```
    Register a listener to be informed when AX.25 connected-mode session state changes.
    
    Parameters:
    
    l - ConnStateChangeListener to register
  - removeConnStateChangeListener
```
public static void removeConnStateChangeListener(ConnStateChangeListener l)
```
    Unregister a listener to be informed when AX.25 connected-mode session state changes.
    
    Parameters:
    
    l - ConnStateChangeListener to unregister

Class AX25Stack

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

WAIT_FOR_ACK_T1_TIMER

Method Detail

getInstance

getDigipeaters

setDigipeaters

getToCall

setToCall

setDebug

getTransmitting

setTransmitting

getRetransTimer

isAllowInboundConnectedMode

setAllowInboundConnectedMode

addAX25FrameListener

removeAX25FrameListener

getConnectionRequestListener

setConnectionRequestListener

registerProtocolParser

getParser

fireConsumeAX25Frame

consumeFrame

getCurrentBacklog

getMaxBacklog

getMaxQueueCapacity

getNumConsumedMsgs

run

isFrozen

setFrozen

consumeFrameNow

getConnectionMap

getStateOf

getConnState

removeConnState

dupUnuseDigipeaters

reverseDigipeaters

processIBody

processParsedAX25Message

addParsedAX25MessageListener

removeParsedAX25MessageListener

isLocalDest

isLocalDest

addConnStateChangeListener

removeConnStateChangeListener