package net.i2p.data.i2np;
/*
* free (adj.): unencumbered; not under the control of others
* Written by jrandom in 2003 and released into the public domain
* with no warranty of any kind, either expressed or implied.
* It probably won't make your computer catch on fire, or eat
* your children, but it might. Use at your own risk.
*
*/
import java.io.IOException;
import java.io.InputStream;
import net.i2p.data.DataStructure;
/**
* Base interface for all I2NP messages
*
* @author jrandom
*/
public interface I2NPMessage extends DataStructure {
/** 4 bytes unsigned */
public static final long MAX_ID_VALUE = (1l << 32) - 1l;
/**
* Nominal limit, actual max is much less.
* See website docs for further restrictions due to
* various overhead and limitations in encryption,
* fragmentation, and the transports.
*/
public static final int MAX_SIZE = 64*1024;
/**
* Read the body into the data structures, after the initial type byte, using
* the current class's format as defined by the I2NP specification
*
* Unused - All transports provide encapsulation and so we have byte arrays available.
*
* @param in stream to read from
* starting at type if type is < 0 (16 byte header)
* starting at ID if type is >= 0 (15 byte header)
* @param type I2NP message type. If less than zero, read the type from data
* @param buffer scratch buffer to be used when reading and parsing
* @return size of the message read (including headers)
* @throws I2NPMessageException if the stream doesn't contain a valid message
* that this class can read.
* @throws IOException if there is a problem reading from the stream
* @deprecated unused
*/
@Deprecated
public int readBytes(InputStream in, int type, byte buffer[]) throws I2NPMessageException, IOException;
/**
* Read the body into the data structures, after the initial type byte, using
* the current class's format as defined by the I2NP specification
*
* @param data the data
* @param type I2NP message type. If less than zero, read the type from data
* @param offset where to start
* starting at type if type is < 0 (16 byte header)
* starting at ID if type is >= 0 (15 byte header)
* @return size of the message read (including headers)
* @throws I2NPMessageException if there is no valid message
*/
public int readBytes(byte data[], int type, int offset) throws I2NPMessageException;
/**
* Read the body into the data structures, after the initial type byte, using
* the current class's format as defined by the I2NP specification
*
* @param data the data, may or may not include the type
* @param type I2NP message type. If less than zero, read the type from data
* @param offset where to start
* starting at type if type is < 0 (16 byte header)
* starting at ID if type is >= 0 (15 byte header)
* @param 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
* @return size of the message read (including headers)
* @throws I2NPMessageException if there is no valid message
* @since 0.8.12
*/
public int readBytes(byte data[], int type, int offset, int maxLen) throws I2NPMessageException;
/**
* Read the body into the data structures, after the initial type byte and
* the uniqueId / expiration, using the current class's format as defined by
* the I2NP specification
*
* @param data data to read from
* @param offset where to start in the data array
* @param dataSize how long into the data to read
* @param type I2NP message type
* @throws I2NPMessageException if the stream doesn't contain a valid message
* that this class can read.
*/
public void readMessage(byte data[], int offset, int dataSize, int type) throws I2NPMessageException;
public void readMessage(byte data[], int offset, int dataSize, int type, I2NPMessageHandler handler) throws I2NPMessageException;
/**
* Return the unique identifier for this type of I2NP message, as defined in
* the I2NP spec
*/
public int getType();
/**
* Replay resistant message ID
*/
public long getUniqueId();
public void setUniqueId(long id);
/**
* Date after which the message should be dropped (and the associated uniqueId forgotten)
*
*/
public long getMessageExpiration();
public void setMessageExpiration(long exp);
/** How large the message is, including any checksums, i.e. full 16 byte header */
public int getMessageSize();
/** How large the raw message is with the short 5 byte header */
public int getRawMessageSize();
/**
* 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.
*/
public int toByteArray(byte buffer[]);
/**
* write the message to the buffer, returning the number of bytes written.
* 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 5 byte header.
*/
public int toRawByteArray(byte buffer[]);
}