UnknownI2NPMessage

net.i2p.data.i2np.UnknownI2NPMessage

All Implemented Interfaces:: I2NPMessage

public class UnknownI2NPMessageextends FastI2NPMessageImpl

This is similar to DataMessage or GarlicMessage but with a variable message type. This is defined so routers can route messages they don't know about. We don't extend those classes so that any code that does (instanceof foo) won't return true for this type. Load tests use DataMessage, for example. Also, those classes include an additional length field that we can't use here. See InboundMessageDistributor.

There is no setData() method, the only way to create one of these is to read it with readMessage(byte[], int, int, int) (i.e., it came from some other router)

As of 0.8.12 this class is working. It is used at the IBGW to reduce the processing required. For zero-hop IB tunnels, the convert() method is used to reconstitute a standard message class.

Nested Class Summary
Nested classes/interfaces inherited from class I2NPMessageImpl
I2NPMessageImpl.Builder
Modifier and Type
Class
Description
static interface
I2NPMessageImpl.Builder
Interface for extending the types of messages handled - unused.
Field Summary
Fields
Modifier and Type
Field
Description
private byte[]
_data
The message contents, as read from the wire.
private final int
_type
The message type number.
Fields inherited from class FastI2NPMessageImpl
_checksum, _hasChecksum
Modifier and Type
Field
Description
protected byte
_checksum
One-byte checksum.
protected boolean
_hasChecksum
Whether the message includes a checksum.
Fields inherited from class I2NPMessageImpl
_context, _expiration, _log, CHECKSUM_LENGTH, DEFAULT_EXPIRATION_MS, HEADER_LENGTH
Modifier and Type
Field
Description
protected final I2PAppContext
_context
Application context this message belongs to.
protected long
_expiration
Expiration time in milliseconds since the epoch, as an I2P Date.
protected final Log
_log
Log for the message class, taken from the context's log manager.
static final int
CHECKSUM_LENGTH
Number of checksum bytes the message header carries.
static final long
DEFAULT_EXPIRATION_MS
Default lifetime of an unsent message, one minute in milliseconds.
static final int
HEADER_LENGTH
I2NP message header size in bytes.
Fields inherited from interface I2NPMessage
MAX_ID_VALUE, MAX_SIZE
Modifier and Type
Field
Description
static final long
MAX_ID_VALUE
4 bytes unsigned.
static final int
MAX_SIZE
Nominal limit, actual max is much less.
Constructor Summary
Constructors
Constructor
Description
UnknownI2NPMessage(I2PAppContext context, int type)
Message with the given type, unknown to the router.
Method Summary
Public Methods
Modifier and Type
Method
Description
protected int
calculateWrittenLength()
Calculate the message body's length (not including the header and footer).
I2NPMessage
convert()
Attempt to convert this message to a known message class.
boolean
equals(Object object)

int
getType()
Note that this returns the "true" type, so that the IBGW can correctly make drop decisions.
int
hashCode()

void
readMessage(byte[] data, int offset, int dataSize, int type)
Raw message data; may only be set once.
String
toString()

protected int
writeMessageBody(byte[] out, int curIndex)
Write the message body to the output array, starting at the given index.
Methods inherited from class FastI2NPMessageImpl
readBytes, toByteArray, toByteArrayWithSavedChecksum
Modifier and Type
Method
Description
int
readBytes(byte[] data, int type, int offset, int maxLen)
Ignore, but save, the checksum, to be used later if necessary.
int
toByteArray(byte[] buffer)
If available, use the previously-computed or previously-read checksum for speed.
protected int
toByteArrayWithSavedChecksum(byte[] buffer)
Use a previously-computed checksum for speed.
Methods inherited from class I2NPMessageImpl
createMessage, fromRawByteArray, fromRawByteArrayNTCP2, getMessageExpiration, getMessageSize, getRawMessageSize, getUniqueId, getUniqueId, readBytes, readMessage, setMessageExpiration, setUniqueId, toByteArray, toByteArray, toRawByteArray, toRawByteArrayNTCP2
Modifier and Type
Method
Description
static I2NPMessage
createMessage(I2PAppContext context, int type)
Yes, this is fairly ugly, but its the only place it ever happens.
static I2NPMessage
fromRawByteArray(I2PAppContext ctx, byte[] buffer, int offset, int len, I2NPMessageHandler handler)
Read the message with a short 5-byte header.
static I2NPMessage
fromRawByteArrayNTCP2(I2PAppContext ctx, byte[] buffer, int offset, int len, I2NPMessageHandler handler)
Read the message with a short 9-byte header.
long
getMessageExpiration()
Date after which the message should be dropped (and the associated uniqueId forgotten).
int
getMessageSize()
Serialized message size, including the 16-byte header.
int
getRawMessageSize()
The raw header consists of a one-byte type and a 4-byte expiration in seconds only.
long
getUniqueId()
Unique id for this message, lazily initialized when negative.
long
getUniqueId(long msgIDBloomXor)
Replay resistant message Id.
int
readBytes(byte[] data, int type, int offset)
Read the header, then read the rest into buffer, then call readMessage in the implemented message type.
void
readMessage(byte[] data, int offset, int dataSize, int type, I2NPMessageHandler handler)
Read the message fields from the byte array, ignoring the handler.
void
setMessageExpiration(long exp)
The expiration is set to one minute from now in the constructor but it can be overridden here.
void
setUniqueId(long id)
The ID is set to a random value when written but it can be overridden here.
byte[]
toByteArray()
The message serialized into a new byte array.
int
toByteArray(byte[] buffer, int off)
Write the message to the buffer, returning the new offset (NOT the length).
int
toRawByteArray(byte[] buffer)
Write the message with a short 5-byte header.
int
toRawByteArrayNTCP2(byte[] buffer, int off)
Write the message to the buffer, returning the new offset (NOT the length).
Methods inherited from class Object
clone, getClass, notify, notifyAll, wait, wait, wait

Field Details
- _data
  private byte[] _data
  The message contents, as read from the wire.
- _type
  private final int _type
  The message type number.
Constructor Details
- UnknownI2NPMessage
  public UnknownI2NPMessage(I2PAppContext context, int type)
  Message with the given type, unknown to the router.
  Parameters:
  context - the app context for the message
  type - 0-255
Method Details
- readMessage
  public void readMessage(byte[] data, int offset, int dataSize, int type) throws I2NPMessageException
  Raw message data; may only be set once.
  Parameters:
  data - data to read from
  offset - where to start in the data array
  dataSize - how long into the data to read
  type - I2NP message type
  Throws:
  IllegalStateException - if data previously set, to protect saved checksum
  I2NPMessageException - if the stream doesn't contain a valid message that this class can read.
- calculateWrittenLength
  protected int calculateWrittenLength()
  Calculate the message body's length (not including the header and footer).
  Specified by:
  calculateWrittenLength in class I2NPMessageImpl
  Returns:
  the number of bytes the body will occupy once serialized
- writeMessageBody
  protected int writeMessageBody(byte[] out, int curIndex)
  Write the message body to the output array, starting at the given index.
  Specified by:
  writeMessageBody in class I2NPMessageImpl
  Parameters:
  out - the buffer to serialize the body into
  curIndex - the offset into out at which to begin writing; leave room for the signature where the header format calls for one
  Returns:
  the index into the array after the last byte written (NOT the length)
- getType
  public int getType()
  Note that this returns the "true" type, so that the IBGW can correctly make drop decisions.
  Returns:
  0-255
- convert
  public I2NPMessage convert() throws I2NPMessageException
  Attempt to convert this message to a known message class. This does the delayed verification using the saved checksum.
  Used by TunnelGatewayZeroHop.
  Returns:
  the message as its known subclass, verified against the saved checksum
  Throws:
  I2NPMessageException - if the conversion fails
- hashCode
  public int hashCode()
  Overrides:
  hashCode in class Object
- equals
  public boolean equals(Object object)
  Overrides:
  equals in class Object
- toString
  public String toString()
  Overrides:
  toString in class Object

Nested Class Summary

Nested classes/interfaces inherited from class I2NPMessageImpl

Field Summary

Fields inherited from class FastI2NPMessageImpl

Fields inherited from class I2NPMessageImpl

Fields inherited from interface I2NPMessage

Constructor Summary

Method Summary

Methods inherited from class FastI2NPMessageImpl

Methods inherited from class I2NPMessageImpl

Methods inherited from class Object

Field Details

_data

_type

Constructor Details

Method Details

readMessage

calculateWrittenLength

writeMessageBody

getType

convert

hashCode

equals

toString