simnet
Class Node

java.lang.Object
  java.lang.Thread
      simnet.Node

All Implemented Interfaces:

Pluggable, java.lang.Runnable, SimnetWindowListener

Direct Known Subclasses:

Host, Router

public abstract class Node

extends java.lang.Thread

implements SimnetWindowListener, Pluggable

The abstract base class for all Nodes.

Field Summary

(package private) java.util.Hashtable	applications A Hashtable that holds all Application objects keyed by their unique IDs
(package private) boolean	default_plugins_loaded Whether or not the default plugins have been loaded.
(package private) SimnetWindow	frame The window frame
(package private) boolean	frozen Global state variable that is set when the Node is in frozen state.
int	id The unique ID of this Node (IP address)
protected java.util.Hashtable	in_filters A Hashtable that holds all incoming IPFilters keyed by their unique IDs
protected java.util.Hashtable	in_links A Hashtable that holds all incoming Links keyed by their unique IDs
(package private) int	ipid Global counter that keeps track of the value previously used for an IP packet' s IP ID field.
boolean	isNatted
(package private) boolean	keep_going When being plugged out, this will be set to false, so that this node's thread can stop running.
java.lang.String	name The name of this Node
(package private) NATRouter	natGW
(package private) NodeStatistics	ns Tracking packet statistics
protected java.util.Hashtable	out_filters A Hashtable that holds all outgoing IPFilters keyed by their unique IDs
protected java.util.Hashtable	out_links A Hashtable that holds all outgoing Links keyed by their unique IDs
(package private) boolean	pause Global state variable that is set when the Node is in pause state.
(package private) LinkProcessor	proc This Node' s LinkProcessor.
protected java.util.Random	random A random number generator
Resolver	resolver The resolver for this node.
(package private) RoutingTable	routing_table The routing table for this node.
(package private) boolean	running Global state variable that is set when the Node is in running state.
protected Simulator	sim The Simulator (Simulator.getSim())
(package private) boolean	sleeping Global state variable that is set when the Node is in sleeping state.
(package private) java.util.Hashtable	transports A Hashtable that holds all Transport objects keyed by their unique IDs
protected UserInterface	ui The User Interface (UserInterface.getUI())
(package private) boolean	win Keeps track of whether an output window has been opened

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Node()

Method Summary

void	addBPF(BPF bpf, int direction, int link_id) Adds the specified BPF rule to the IPFilter associated with the specified Link.
void	addLink(int direction, Link link) Adds the specified Link to this Node's link table.
void	addRule(Rule rule, int direction, int link_id) Adds the specified firewall rule to the IPFilter associated with the specified Link.
void	clear() Clears all of this Node' s stats
void	closeWindow() Close this node's window (if it is open).
boolean	command(java.lang.Object target, java.lang.String command, java.lang.Object[] args) Invoke the method command on the object target with the given arguments.
boolean	command(java.lang.String command, java.lang.Object[] args) Attempts to invoke the specified command with the specified arguments by searching through all this Node's Applications, Transports, Link Processor, Routing Table, Resolver, and the Node itself.
void	deleteRule(int rule_id, int direction, int link_id) Removes the specified firewall rule from the IPFilter associated with the specified Link.
boolean	empty(java.util.Hashtable link_table) Determines whether the specified Links are empty or not.
protected void	finalize() For debugging.
protected abstract void	forward(IP_Packet ip_packet) Forwards incoming IP packets to the appropriate transport protocol (after stripping the IP header).
Application	getApplication(int pid) Returns the Application with the specified (unique) Process ID.
int	getHostByName(java.lang.String host) Looks up the ip for this host using the resolver.
Link	getLink(int to_id) Returns the Link whose To node is specified by the given Node ID.
abstract int	getNodeClass() Returns the class of this Node (either Router or Host)
int	getPluginCount() Returns the number of plugins that are loaded on this node.
java.lang.String	getTitleString() Returns the title that currently describes the state of the node or application that this window is for.
Transport	getTransport(int tid) Returns the Transport with the specified unique ID.
Transport	getTransport(java.lang.String trans) Returns the Transport with the specified name.
void	initialize(int node_id, java.lang.String node_name) Initializes a new Node by setting its ID, name and a pointer to the Simulator, all to the specified values.
void	integrate() Integrate this node by enabling all of its links.
void	isolate() Isolate this node by disabling all of its links.
void	kill() Pauses this Node's thread
java.lang.String	lookup(int nid) Determines the name of the Node with the specified ID.
int	lookup(java.lang.String name) Determines the ID of the Node with the specified name.
boolean	out(int dest, Packet packet) Adds IP and Frame headers to outgoing Transport packets before enqueing them on the appropriate Link.
boolean	prePlugout(java.lang.Object replacement) To be replaced, stop our thread; to be removed, remove links and then stop the thread.
void	printout(int level, int src, java.lang.String msg) To make the old code compile (temporary)
void	printout(java.lang.String category, int level, int src, java.lang.String message) Prints the specified message if the current verbosity level is equal to or higher than the specified level and the specified category should be shown.
void	processWindowCommand(java.lang.String text) The command text has been input in the window.
void	removeBPF(BPF bpf, int direction, int link_id) Removes the specified BPF rule from the IPFilter associated with the specified Link.
boolean	removeLink(int direction, int other) Removes the specified Link in this Node's link table.
void	run() Wait for packets, and forward them.
void	setupNAT(NATRouter natGW) Set a flag so we know that we are natted, and a pointer to our gateway.
void	start() Starts this Node' s thread
void	stateful_kill() Starts this Node' s thread if it is not running.
void	stateful_start() Pauses this Node' s thread if it is running.
private java.lang.String	tabularize(java.lang.String string) Inserts tabs in a string (is this used?).
java.lang.String	toString() Returns a string with information about this Node.
java.lang.String	toString(int type) Returns a string with information about this Node The type determines the kind of information returned: 0 - all 1 - loaded plugins 2 - link information 3 - firewall rules
void	window() Starts an Individual Interface Window (IIW) associated with this node.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, stop, stop, suspend, yield

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

id

public int id

The unique ID of this Node (IP address)

name

public java.lang.String name

The name of this Node

sim

protected Simulator sim

The Simulator (Simulator.getSim())

ui

protected UserInterface ui

The User Interface (UserInterface.getUI())

in_filters

protected java.util.Hashtable in_filters

A Hashtable that holds all incoming IPFilters keyed by their unique IDs

out_filters

protected java.util.Hashtable out_filters

A Hashtable that holds all outgoing IPFilters keyed by their unique IDs

in_links

protected java.util.Hashtable in_links

A Hashtable that holds all incoming Links keyed by their unique IDs

out_links

protected java.util.Hashtable out_links

A Hashtable that holds all outgoing Links keyed by their unique IDs

proc

LinkProcessor proc

This Node' s LinkProcessor. No more default.

routing_table

RoutingTable routing_table

The routing table for this node.

resolver

public Resolver resolver

The resolver for this node.

transports

java.util.Hashtable transports

A Hashtable that holds all Transport objects keyed by their unique IDs

applications

java.util.Hashtable applications

A Hashtable that holds all Application objects keyed by their unique IDs

random

protected java.util.Random random

A random number generator

ns

NodeStatistics ns

Tracking packet statistics

running

boolean running

Global state variable that is set when the Node is in running state.

pause

boolean pause

Global state variable that is set when the Node is in pause state.

sleeping

boolean sleeping

Global state variable that is set when the Node is in sleeping state.

frozen

boolean frozen

Global state variable that is set when the Node is in frozen state.

keep_going

transient boolean keep_going

When being plugged out, this will be set to false, so that this node's thread can stop running.

ipid

int ipid

Global counter that keeps track of the value previously used for an IP packet' s IP ID field.

isNatted

public boolean isNatted

natGW

NATRouter natGW

default_plugins_loaded

boolean default_plugins_loaded

Whether or not the default plugins have been loaded. Note that they will only be loaded when a node is first plugged in, rather then each time a node is replaced.

frame

SimnetWindow frame

The window frame

win

boolean win

Keeps track of whether an output window has been opened

Constructor Detail

Node

public Node()

Method Detail

getNodeClass

public abstract int getNodeClass()

Returns the class of this Node (either Router or Host)

setupNAT

public void setupNAT(NATRouter natGW)

Set a flag so we know that we are natted, and a pointer to our gateway.

Parameters:

natGW - The node who assigned us an ip.

initialize

public void initialize(int node_id,
                       java.lang.String node_name)

Initializes a new Node by setting its ID, name and a pointer to the Simulator, all to the specified values.

Parameters:

node_id - this Node's unique ID

node_name - this Node' s name

start

public void start()

Starts this Node' s thread

run

public void run()

Wait for packets, and forward them.

Specified by:

run in interface java.lang.Runnable

forward

protected abstract void forward(IP_Packet ip_packet)

Forwards incoming IP packets to the appropriate transport protocol (after stripping the IP header). This is an abstract class that must be implemented by every Host and Router.

Parameters:

ip_packet - incoming IP packet to be forwarded

getHostByName

public int getHostByName(java.lang.String host)

Looks up the ip for this host using the resolver. If no resolver is loaded, a timeout error is returned (but without the wait).

kill

public void kill()

Pauses this Node's thread

out

public boolean out(int dest,
                   Packet packet)

Adds IP and Frame headers to outgoing Transport packets before enqueing them on the appropriate Link.

Parameters:

dest - destination Node

packet - outgoing Transport packet

addLink

public void addLink(int direction,
                    Link link)

Adds the specified Link to this Node's link table.

Parameters:

direction - specifies whether the Link should be added to the incoming link table (Simnet.IN) or the outgoing link table (Simnet.OUT)

link - the Link object to add

removeLink

public boolean removeLink(int direction,
                          int other)

Removes the specified Link in this Node's link table.

Parameters:

direction - specifies whether the Link should be added to the incoming link table (Simnet.IN) or the outgoing link table (Simnet.OUT)

other - the id (IP) of the other end of the link to remove

Returns:

If the link was sucessfully removed (if the link did not exist, true is returned)

isolate

public void isolate()

Isolate this node by disabling all of its links.

integrate

public void integrate()

Integrate this node by enabling all of its links.

addRule

public void addRule(Rule rule,
                    int direction,
                    int link_id)

Adds the specified firewall rule to the IPFilter associated with the specified Link.

Parameters:

rule - the firewall rule to add

direction - specifies whether the link is incoming (Simnet.IN) or outgoing (Simnet.OUT)

link_id - specifies the ID of the Link to which the rule should be added

deleteRule

public void deleteRule(int rule_id,
                       int direction,
                       int link_id)

Removes the specified firewall rule from the IPFilter associated with the specified Link.

Parameters:

rule_id - the ID of the firewall rule to remove

direction - specifies whether the link is incoming (Simnet.IN) or outgoing (Simnet.OUT)

link_id - specifies the ID of the Link from which the rule should be removed

addBPF

public void addBPF(BPF bpf,
                   int direction,
                   int link_id)

Adds the specified BPF rule to the IPFilter associated with the specified Link.

Parameters:

bpf - the bpf rule to add

direction - specifies whether the link is incoming (Simnet.IN) or outgoing (Simnet.OUT)

link_id - the ID of the Link. Here the ID of the Link really refers to the ID of the Node it connects to (on the other end). This is confusing since Links actually have their own IDs...

removeBPF

public void removeBPF(BPF bpf,
                      int direction,
                      int link_id)

Removes the specified BPF rule from the IPFilter associated with the specified Link.

Parameters:

bpf - the ID of the firewall rule to remove

direction - specifies whether the link is incoming (Simnet.IN) or outgoing (Simnet.OUT)

link_id - ...

stateful_kill

public void stateful_kill()

Starts this Node' s thread if it is not running. When used in conjunction with stateful_start() the two methods will return the Node to its original pause/running state.

stateful_start

public void stateful_start()

Pauses this Node' s thread if it is running. When used in conjunction with stateful_start() the two methods will return the Node to its original pause/running state.

command

public boolean command(java.lang.String command,
                       java.lang.Object[] args)

Attempts to invoke the specified command with the specified arguments by searching through all this Node's Applications, Transports, Link Processor, Routing Table, Resolver, and the Node itself. A command in the form "xxx.command" will only invoke the command on the application with process id = xxx.

Parameters:

command - the command to invoke

args - the command' s arguments

Returns:

TRUE if the command was found and invoked; false otherwise

command

public boolean command(java.lang.Object target,
                       java.lang.String command,
                       java.lang.Object[] args)

Invoke the method command on the object target with the given arguments.

Returns:

true if the invocation was sucessful, false otherwise

getTransport

public Transport getTransport(int tid)

Returns the Transport with the specified unique ID.

Parameters:

tid - the Transport' s ID

Returns:

the Transport with the specified ID; null if it does not exist

getTransport

public Transport getTransport(java.lang.String trans)

Returns the Transport with the specified name.

Parameters:

trans - the Transport' s name

Returns:

the Transport with the specified name; null if it does not exist

getApplication

public Application getApplication(int pid)

Returns the Application with the specified (unique) Process ID.

Parameters:

pid - the Application's Process ID

Returns:

the Application with the specified PID; null if it does not exist

getLink

public Link getLink(int to_id)

Returns the Link whose To node is specified by the given Node ID.

Parameters:

to_id - the ID of the Link' s To Node

Returns:

the Link whose To node has the specified ID

lookup

public java.lang.String lookup(int nid)

Determines the name of the Node with the specified ID.

Parameters:

nid - the Node' s ID

Returns:

the name of the specified Node; null if it does not exist

lookup

public int lookup(java.lang.String name)

Determines the ID of the Node with the specified name.

Parameters:

name - the Node' s name

Returns:

the ID of the specified node; -1 if it does not exist.

clear

public void clear()

Clears all of this Node' s stats

empty

public boolean empty(java.util.Hashtable link_table)

Determines whether the specified Links are empty or not.

Parameters:

link_table - a link table

Returns:

TRUE if all Links in the specified table are empty; FALSE otherwise

window

public void window()

Starts an Individual Interface Window (IIW) associated with this node.

getTitleString

public java.lang.String getTitleString()

Returns the title that currently describes the state of the node or application that this window is for.

Specified by:

getTitleString in interface SimnetWindowListener

closeWindow

public void closeWindow()

Close this node's window (if it is open).

Specified by:

closeWindow in interface SimnetWindowListener

processWindowCommand

public void processWindowCommand(java.lang.String text)

The command text has been input in the window.

Specified by:

processWindowCommand in interface SimnetWindowListener

printout

public void printout(java.lang.String category,
                     int level,
                     int src,
                     java.lang.String message)

Prints the specified message if the current verbosity level is equal to or higher than the specified level and the specified category should be shown. If an IIW has been opened the message is output to the window, if not it is output to the UI.

Parameters:

category - the category of the message

level - the verbosity level of the message

src - the ID of the source Node of the message

message - the error message

printout

public void printout(int level,
                     int src,
                     java.lang.String msg)

To make the old code compile (temporary)

toString

public java.lang.String toString()

Returns a string with information about this Node. Same as toString(0);

Returns:

the complete string representation for this node

toString

public java.lang.String toString(int type)

Returns a string with information about this Node The type determines the kind of information returned: 0 - all 1 - loaded plugins 2 - link information 3 - firewall rules

Parameters:

type - determines the kind of information to return

Returns:

specific information about this node

tabularize

private java.lang.String tabularize(java.lang.String string)

Inserts tabs in a string (is this used?).

Parameters:

string - string to format

Returns:

a new string with tabs

getPluginCount

public int getPluginCount()

Returns the number of plugins that are loaded on this node.

prePlugout

public boolean prePlugout(java.lang.Object replacement)

To be replaced, stop our thread; to be removed, remove links and then stop the thread.

Specified by:

prePlugout in interface Pluggable

Returns:

if this object can now be removed (was the operation sucessful)

finalize

protected void finalize()

For debugging.