net.i2p.data.i2np

Class I2NPMessageImpl

java.lang.Object

net.i2p.data.i2np.I2NPMessageImpl

All Implemented Interfaces:

I2NPMessage

Direct Known Subclasses:

FastI2NPMessageImpl, TunnelBuildMessageBase

public abstract class I2NPMessageImpl
extends Object
implements I2NPMessage

Defines the base message implementation. Note: No longer extends DataStructureImpl as of 0.9.48

Author:

jrandom

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	I2NPMessageImpl.Builder interface for extending the types of messages handled - unused

Field Summary

Fields

Modifier and Type	Field and Description
protected net.i2p.I2PAppContext	_context
protected long	_expiration
protected net.i2p.util.Log	_log
static int	CHECKSUM_LENGTH
static long	DEFAULT_EXPIRATION_MS
static int	HEADER_LENGTH 16

Fields inherited from interface net.i2p.data.i2np.I2NPMessage

MAX_ID_VALUE, MAX_SIZE

Constructor Summary

Constructors

Constructor and Description
I2NPMessageImpl(net.i2p.I2PAppContext context)

Method Summary

Modifier and Type	Method and Description
protected abstract int	calculateWrittenLength() calculate the message body's length (not including the header and footer
static I2NPMessage	createMessage(net.i2p.I2PAppContext context, int type) Yes, this is fairly ugly, but its the only place it ever happens.
static I2NPMessage	fromRawByteArray(net.i2p.I2PAppContext ctx, byte[] buffer, int offset, int len, I2NPMessageHandler handler) Read the message with a short 5-byte header.
static I2NPMessage	fromRawByteArrayNTCP2(net.i2p.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() How large the message is, including any checksums, i.e.
int	getRawMessageSize() The raw header consists of a one-byte type and a 4-byte expiration in seconds only.
long	getUniqueId() 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
int	readBytes(byte[] data, int type, int offset, int maxLen) Set a limit on the max to read from the data buffer, so that we can use a large buffer but prevent the reader from reading off the end.
void	readBytes(InputStream in) Deprecated. unused
void	readMessage(byte[] data, int offset, int dataSize, int type, I2NPMessageHandler handler)
static void	registerBuilder(I2NPMessageImpl.Builder builder, int type) Deprecated. unused
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()
int	toByteArray(byte[] buffer) write the message to the buffer, returning the number of bytes written.
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).
void	writeBytes(OutputStream out) Deprecated. unused
protected abstract int	writeMessageBody(byte[] out, int curIndex) write the message body to the output array, starting at the given index.

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.i2p.data.i2np.I2NPMessage

getType, readMessage

Field Detail

_log

protected final net.i2p.util.Log _log

_context

protected final net.i2p.I2PAppContext _context

_expiration

protected long _expiration

DEFAULT_EXPIRATION_MS

public static final long DEFAULT_EXPIRATION_MS

See Also:

Constant Field Values

CHECKSUM_LENGTH

public static final int CHECKSUM_LENGTH

See Also:

Constant Field Values

HEADER_LENGTH

public static final int HEADER_LENGTH

16

See Also:

Constant Field Values

Constructor Detail

I2NPMessageImpl

public I2NPMessageImpl(net.i2p.I2PAppContext context)

Method Detail

registerBuilder

@Deprecated
public static final void registerBuilder(I2NPMessageImpl.Builder builder,
                                                     int type)

Deprecated. unused

readBytes

@Deprecated
public void readBytes(InputStream in)

Deprecated. unused

Read the whole message. Unused - All transports provide encapsulation and so we have byte arrays available.

Throws:

UnsupportedOperationException - always

readBytes

public int readBytes(byte[] data,
                     int type,
                     int offset)
              throws I2NPMessageException

Read the header, then read the rest into buffer, then call readMessage in the implemented message type

  Specifically:
    1 byte type (if caller didn't read already, as specified by the type param
    4 byte ID
    8 byte expiration
    2 byte size
    1 byte checksum
    size bytes of payload (read by readMessage() in implementation)

Specified by:

readBytes in interface I2NPMessage

Parameters:

type - the message type or -1 if we should read it here

data - the data

offset - where to start starting at type if type is < 0 (16 byte header) starting at ID if type is >= 0 (15 byte header)

Returns:

total length of the message

Throws:

I2NPMessageException - if there is no valid message

readBytes

public int readBytes(byte[] data,
                     int type,
                     int offset,
                     int maxLen)
              throws I2NPMessageException

Set a limit on the max to read from the data buffer, so that we can use a large buffer but prevent the reader from reading off the end.

Specified by:

readBytes in interface I2NPMessage

Parameters:

type - the message type or -1 if we should read it here

maxLen - read no more than this many bytes from data starting at offset, even if it is longer This includes the type byte only if type < 0

data - the data, may or may not include the type

offset - where to start starting at type if type is < 0 (16 byte header) starting at ID if type is >= 0 (15 byte header)

Returns:

total length of the message

Throws:

I2NPMessageException - if there is no valid message

Since:

0.8.12

writeBytes

@Deprecated
public void writeBytes(OutputStream out)

Deprecated. unused

Don't do this if you need a byte array - use toByteArray()

Throws:

UnsupportedOperationException - always

getUniqueId

public long getUniqueId()

Replay resistant message Id

Specified by:

getUniqueId in interface I2NPMessage

setUniqueId

public void setUniqueId(long id)

The ID is set to a random value when written but it can be overridden here.

Specified by:

setUniqueId in interface I2NPMessage

getMessageExpiration

public long getMessageExpiration()

Date after which the message should be dropped (and the associated uniqueId forgotten)

Specified by:

getMessageExpiration in interface I2NPMessage

setMessageExpiration

public void setMessageExpiration(long exp)

The expiration is set to one minute from now in the constructor but it can be overridden here.

Specified by:

setMessageExpiration in interface I2NPMessage

getMessageSize

public int getMessageSize()

Description copied from interface: I2NPMessage

How large the message is, including any checksums, i.e. full 16 byte header

Specified by:

getMessageSize in interface I2NPMessage

getRawMessageSize

public int getRawMessageSize()

The raw header consists of a one-byte type and a 4-byte expiration in seconds only. Used by SSU only!

Specified by:

getRawMessageSize in interface I2NPMessage

toByteArray

public byte[] toByteArray()

Specified by:

toByteArray in interface I2NPMessage

toByteArray

public int toByteArray(byte[] buffer)

write the message to the buffer, returning the number of bytes written. the data is formatted so as to be self contained, with the type, size, expiration, unique id, as well as a checksum bundled along. Full 16 byte header for NTCP 1.

Specified by:

toByteArray in interface I2NPMessage

Returns:

the length written

toByteArray

public int toByteArray(byte[] buffer,
                       int off)

Write the message to the buffer, returning the new offset (NOT the length). the data is formatted so as to be self contained, with the type, size, expiration, unique id, as well as a checksum bundled along. Full 16 byte header for NTCP 1.

Specified by:

toByteArray in interface I2NPMessage

Parameters:

off - the offset to start writing at

Returns:

the new offset (NOT the length)

Since:

0.9.36 with off param

calculateWrittenLength

protected abstract int calculateWrittenLength()

calculate the message body's length (not including the header and footer

writeMessageBody

protected abstract int writeMessageBody(byte[] out,
                                        int curIndex)
                                 throws I2NPMessageException

write the message body to the output array, starting at the given index.

Returns:

the index into the array after the last byte written (NOT the length)

Throws:

I2NPMessageException

toRawByteArray

public int toRawByteArray(byte[] buffer)

Write the message with a short 5-byte header. THe header consists of a one-byte type and a 4-byte expiration in seconds only. Used by SSU only!

Specified by:

toRawByteArray in interface I2NPMessage

Returns:

the new offset (NOT the length)

toRawByteArrayNTCP2

public int toRawByteArrayNTCP2(byte[] buffer,
                               int off)

Write the message to the buffer, returning the new offset (NOT the length). the data is is not self contained - it does not include the size, unique id, or any checksum, but does include the type and expiration. Short 9 byte header for NTCP 2.

Specified by:

toRawByteArrayNTCP2 in interface I2NPMessage

Parameters:

off - the offset to start writing at

Returns:

the new offset (NOT the length)

Since:

0.9.36

readMessage

public void readMessage(byte[] data,
                        int offset,
                        int dataSize,
                        int type,
                        I2NPMessageHandler handler)
                 throws I2NPMessageException

Specified by:

readMessage in interface I2NPMessage

Throws:

I2NPMessageException

fromRawByteArray

public static I2NPMessage fromRawByteArray(net.i2p.I2PAppContext ctx,
                                           byte[] buffer,
                                           int offset,
                                           int len,
                                           I2NPMessageHandler handler)
                                    throws I2NPMessageException

Read the message with a short 5-byte header. THe header consists of a one-byte type and a 4-byte expiration in seconds only. Used by SSU only!

Throws:

I2NPMessageException

fromRawByteArrayNTCP2

public static I2NPMessage fromRawByteArrayNTCP2(net.i2p.I2PAppContext ctx,
                                                byte[] buffer,
                                                int offset,
                                                int len,
                                                I2NPMessageHandler handler)
                                         throws I2NPMessageException

Read the message with a short 9-byte header. THe header consists of a one-byte type, 4-byte ID, and a 4-byte expiration in seconds only. Used by NTCP2 only!

Throws:

I2NPMessageException

Since:

0.9.35

createMessage

public static I2NPMessage createMessage(net.i2p.I2PAppContext context,
                                        int type)
                                 throws I2NPMessageException

Yes, this is fairly ugly, but its the only place it ever happens.

Returns:

non-null, returns an UnknownI2NPMessage if unknown type

Throws:

I2NPMessageException