TunnelGatewayMessage

net.i2p.data.i2np.TunnelGatewayMessage

All Implemented Interfaces:: I2NPMessage

public class TunnelGatewayMessageextends FastI2NPMessageImpl

Defines the message sent between one tunnel's endpoint and another's gateway. format: { tunnelId, sizeof(i2npMessage.toByteArray()), i2npMessage.toByteArray() }.

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
Modifier and Type
Field
Description
private I2NPMessage
_msg
The message carried inside.
private byte[]
_msgData
The carried message, as bytes.
private TunnelId
_tunnelId
The tunnel this message enters.
private static final int
EXPIRATION_PERIOD
If we can't deliver a tunnel message in 10s, forget it.
static final int
MESSAGE_TYPE
Message type ID for this I2NP message.
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
TunnelGatewayMessage(I2PAppContext context)
Constructor with 10-second message expiration from context clock.
Method Summary
Public Methods
Modifier and Type
Method
Description
protected int
calculateWrittenLength()
Calculate the serialized length of this message.
boolean
equals(Object object)
Two TunnelGatewayMessages are equal if they have the same tunnel ID and message content.
I2NPMessage
getMessage()
Warning, at the IBGW, where the message was read in, this will be an UnknownI2NPMessage.
TunnelId
getTunnelId()
Return the tunnel to deliver this message to.
int
getType()
Return the type.
int
hashCode()
Hash based on tunnel ID and embedded message.
void
readMessage(byte[] data, int offset, int dataSize, int type)
Read and parse the message from raw data into fields.
void
readMessage(byte[] data, int offset, int dataSize, int type, I2NPMessageHandler handler)
Note that for efficiency at the IBGW, this does not fully deserialize the included I2NP Message.
void
setMessage(I2NPMessage msg)
Embedded message; may only be set once.
void
setTunnelId(TunnelId id)
Tunnel ID for this message; may only be set once.
String
toString()
Label with message ID, tunnel ID, and embedded message for logging.
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, 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
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
- _tunnelId
  private TunnelId _tunnelId
  The tunnel this message enters.
- _msg
  private I2NPMessage _msg
  The message carried inside.
- _msgData
  private byte[] _msgData
  The carried message, as bytes.
- MESSAGE_TYPE
  public static final int MESSAGE_TYPE
  Message type ID for this I2NP message.
  See Also:
  Constant Field Values
- EXPIRATION_PERIOD
  private static final int EXPIRATION_PERIOD
  If we can't deliver a tunnel message in 10s, forget it.
  See Also:
  Constant Field Values
Constructor Details
- TunnelGatewayMessage
  public TunnelGatewayMessage(I2PAppContext context)
  Constructor with 10-second message expiration from context clock.
  Parameters:
  context - the router context whose clock timestamps this message's expiration
Method Details
- getTunnelId
  public TunnelId getTunnelId()
  Return the tunnel to deliver this message to.
  Returns:
  the ID of the tunnel to deliver to, null until setTunnelId has been called
- setTunnelId
  public void setTunnelId(TunnelId id)
  Tunnel ID for this message; may only be set once.
  Parameters:
  id - the ID of the tunnel that must deliver this message to the far endpoint
  Throws:
  IllegalStateException - if id previously set, to protect saved checksum
- getMessage
  public I2NPMessage getMessage()
  Warning, at the IBGW, where the message was read in, this will be an UnknownI2NPMessage. If you need a real message class, use UnknownI2NPMessage.convert().
  Warning, will be null after message has been written.
  Note that if you change the expiration on the embedded message it will mess up the checksum of this message, so don't do that.
  Returns:
  the message carried onward through the tunnel, held as an UnknownI2NPMessage when this instance was read at the IBGW, or null once this message has been written out
- setMessage
  public void setMessage(I2NPMessage msg)
  Embedded message; may only be set once.
  Parameters:
  msg - the message to carry onward through the tunnel, which must not be null
  Throws:
  IllegalStateException - if msg previously set, to protect saved checksum
- calculateWrittenLength
  protected int calculateWrittenLength()
  Calculate the serialized length of this message.
  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) throws I2NPMessageException
  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)
  Throws:
  I2NPMessageException - if the body cannot be serialized into out, because it is too small or a field is unserializable
- readMessage
  public void readMessage(byte[] data, int offset, int dataSize, int type) throws I2NPMessageException
  Read and parse the message from raw data into fields.
  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:
  I2NPMessageException - if the stream doesn't contain a valid message that this class can read.
- readMessage
  public void readMessage(byte[] data, int offset, int dataSize, int type, I2NPMessageHandler handler) throws I2NPMessageException
  Note that for efficiency at the IBGW, this does not fully deserialize the included I2NP Message. It just puts it in an UnknownI2NPMessage.
  Specified by:
  readMessage in interface I2NPMessage
  Overrides:
  readMessage in class I2NPMessageImpl
  Parameters:
  data - the buffer holding the message, header included
  offset - where to start in the data array
  dataSize - how long into the data to read
  type - I2NP message type
  handler - unused, may be null
  Throws:
  I2NPMessageException - if the stream doesn't contain a valid message that this class can read.
- getType
  public int getType()
  Return the type.
  Returns:
  the message type number, as defined in the I2NP spec
- hashCode
  public int hashCode()
  Hash based on tunnel ID and embedded message.
  Overrides:
  hashCode in class Object
  Returns:
  whether h code is present
- equals
  public boolean equals(Object object)
  Two TunnelGatewayMessages are equal if they have the same tunnel ID and message content.
  Overrides:
  equals in class Object
- toString
  public String toString()
  Label with message ID, tunnel ID, and embedded message for logging.
  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

_tunnelId

_msg

_msgData

MESSAGE_TYPE

EXPIRATION_PERIOD

Constructor Details

Method Details

getTunnelId

setTunnelId

getMessage

setMessage

calculateWrittenLength

writeMessageBody

readMessage

readMessage

getType

hashCode

equals

toString