package org.klomp.snark;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import net.i2p.I2PAppContext;
import net.i2p.data.DataHelper;
import net.i2p.util.Log;
import org.klomp.snark.bencode.BDecoder;
import org.klomp.snark.bencode.BEncoder;
import org.klomp.snark.bencode.BEValue;
import org.klomp.snark.comments.Comment;
import org.klomp.snark.comments.CommentSet;
/**
* REF: BEP 10 Extension Protocol
* @since 0.8.2
* @author zzz
*/
abstract class ExtensionHandler {
public static final int ID_HANDSHAKE = 0;
public static final int ID_METADATA = 1;
public static final String TYPE_METADATA = "ut_metadata";
public static final int ID_PEX = 2;
/** not ut_pex since the compact format is different */
public static final String TYPE_PEX = "i2p_pex";
public static final int ID_DHT = 3;
/** not using the option bit since the compact format is different */
public static final String TYPE_DHT = "i2p_dht";
/** @since 0.9.31 */
public static final int ID_COMMENT = 4;
/** @since 0.9.31 */
public static final String TYPE_COMMENT = "ut_comment";
/** Pieces * SHA1 Hash length, + 25% extra for file names, bencoding overhead, etc */
private static final int MAX_METADATA_SIZE = Storage.MAX_PIECES * 20 * 5 / 4;
private static final int PARALLEL_REQUESTS = 3;
/**
* @param metasize -1 if unknown
* @param pexAndMetadata advertise these capabilities
* @param dht advertise DHT capability
* @param comment advertise ut_comment capability
* @return bencoded outgoing handshake message
*/
public static byte[] getHandshake(int metasize, boolean pexAndMetadata, boolean dht, boolean uploadOnly, boolean comment) {
Map<String, Object> handshake = new HashMap<String, Object>();
Map<String, Integer> m = new HashMap<String, Integer>();
if (pexAndMetadata) {
m.put(TYPE_METADATA, Integer.valueOf(ID_METADATA));
m.put(TYPE_PEX, Integer.valueOf(ID_PEX));
if (metasize >= 0)
handshake.put("metadata_size", Integer.valueOf(metasize));
}
if (dht) {
m.put(TYPE_DHT, Integer.valueOf(ID_DHT));
}
if (comment) {
m.put(TYPE_COMMENT, Integer.valueOf(ID_COMMENT));
}
// include the map even if empty so the far-end doesn't NPE
handshake.put("m", m);
handshake.put("p", Integer.valueOf(TrackerClient.PORT));
handshake.put("v", "I2PSnark");
handshake.put("reqq", Integer.valueOf(5));
// BEP 21
if (uploadOnly)
handshake.put("upload_only", Integer.valueOf(1));
return BEncoder.bencode(handshake);
}
public static void handleMessage(Peer peer, PeerListener listener, int id, byte[] bs) {
Log log = I2PAppContext.getGlobalContext().logManager().getLog(ExtensionHandler.class);
if (log.shouldLog(Log.INFO))
log.info("Got extension msg " + id + " length " + bs.length + " from " + peer);
if (id == ID_HANDSHAKE)
handleHandshake(peer, listener, bs, log);
else if (id == ID_METADATA)
handleMetadata(peer, listener, bs, log);
else if (id == ID_PEX)
handlePEX(peer, listener, bs, log);
else if (id == ID_DHT)
handleDHT(peer, listener, bs, log);
else if (id == ID_COMMENT)
handleComment(peer, listener, bs, log);
else if (log.shouldLog(Log.INFO))
log.info("Unknown extension msg " + id + " from " + peer);
}
private static void handleHandshake(Peer peer, PeerListener listener, byte[] bs, Log log) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got handshake msg from " + peer);
try {
// this throws NPE on missing keys
InputStream is = new ByteArrayInputStream(bs);
BDecoder dec = new BDecoder(is);
BEValue bev = dec.bdecodeMap();
Map<String, BEValue> map = bev.getMap();
peer.setHandshakeMap(map);
Map<String, BEValue> msgmap = map.get("m").getMap();
if (log.shouldLog(Log.DEBUG))
log.debug("Peer " + peer + " supports extensions: " + msgmap.keySet());
//if (msgmap.get(TYPE_PEX) != null) {
// if (log.shouldLog(Log.DEBUG))
// log.debug("Peer supports PEX extension: " + peer);
// // peer state calls peer listener calls sendPEX()
//}
//if (msgmap.get(TYPE_DHT) != null) {
// if (log.shouldLog(Log.DEBUG))
// log.debug("Peer supports DHT extension: " + peer);
// // peer state calls peer listener calls sendDHT()
//}
MagnetState state = peer.getMagnetState();
if (msgmap.get(TYPE_METADATA) == null) {
if (log.shouldLog(Log.DEBUG))
log.debug("Peer does not support metadata extension: " + peer);
// drop if we need metainfo and we haven't found anybody yet
synchronized(state) {
if (!state.isInitialized()) {
if (log.shouldLog(Log.DEBUG))
log.debug("Dropping peer, we need metadata! " + peer);
peer.disconnect();
}
}
return;
}
BEValue msize = map.get("metadata_size");
if (msize == null) {
if (log.shouldLog(Log.DEBUG))
log.debug("Peer does not have the metainfo size yet: " + peer);
// drop if we need metainfo and we haven't found anybody yet
synchronized(state) {
if (!state.isInitialized()) {
if (log.shouldLog(Log.DEBUG))
log.debug("Dropping peer, we need metadata! " + peer);
peer.disconnect();
}
}
return;
}
int metaSize = msize.getInt();
if (log.shouldLog(Log.DEBUG))
log.debug("Got the metainfo size: " + metaSize);
int remaining;
synchronized(state) {
if (state.isComplete())
return;
if (state.isInitialized()) {
if (state.getSize() != metaSize) {
if (log.shouldLog(Log.DEBUG))
log.debug("Wrong metainfo size " + metaSize + " from: " + peer);
peer.disconnect();
return;
}
} else {
// initialize it
if (metaSize > MAX_METADATA_SIZE) {
if (log.shouldLog(Log.DEBUG))
log.debug("Huge metainfo size " + metaSize + " from: " + peer);
peer.disconnect(false);
return;
}
if (log.shouldLog(Log.INFO))
log.info("Initialized state, metadata size = " + metaSize + " from " + peer);
state.initialize(metaSize);
}
remaining = state.chunksRemaining();
}
// send requests for chunks
int count = Math.min(remaining, PARALLEL_REQUESTS);
for (int i = 0; i < count; i++) {
int chk;
synchronized(state) {
chk = state.getNextRequest();
}
if (log.shouldLog(Log.INFO))
log.info("Request chunk " + chk + " from " + peer);
sendRequest(peer, chk);
}
} catch (Exception e) {
if (log.shouldLog(Log.WARN))
log.warn("Handshake exception from " + peer, e);
}
}
private static final int TYPE_REQUEST = 0;
private static final int TYPE_DATA = 1;
private static final int TYPE_REJECT = 2;
/**
* REF: BEP 9
* @since 0.8.4
*/
private static void handleMetadata(Peer peer, PeerListener listener, byte[] bs, Log log) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got metadata msg from " + peer);
try {
InputStream is = new ByteArrayInputStream(bs);
BDecoder dec = new BDecoder(is);
BEValue bev = dec.bdecodeMap();
Map<String, BEValue> map = bev.getMap();
int type = map.get("msg_type").getInt();
int piece = map.get("piece").getInt();
MagnetState state = peer.getMagnetState();
if (type == TYPE_REQUEST) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got request for " + piece + " from: " + peer);
byte[] pc;
int totalSize;
synchronized(state) {
pc = state.getChunk(piece);
totalSize = state.getSize();
}
sendPiece(peer, piece, pc, totalSize);
// Do this here because PeerConnectionOut only reports for PIECE messages
peer.uploaded(pc.length);
listener.uploaded(peer, pc.length);
} else if (type == TYPE_DATA) {
// On close reading of BEP 9, this is the total metadata size.
// Prior to 0.9.21, we sent the piece size, so we can't count on it.
// just ignore it. The actual length will be verified in saveChunk()
//int size = map.get("total_size").getInt();
//if (log.shouldLog(Log.DEBUG))
// log.debug("Got data for " + piece + " length " + size + " from: " + peer);
boolean done;
int chk = -1;
synchronized(state) {
if (state.isComplete())
return;
int len = is.available();
peer.downloaded(len);
listener.downloaded(peer, len);
// this checks the size
done = state.saveChunk(piece, bs, bs.length - len, len);
if (log.shouldLog(Log.INFO))
log.info("Got chunk " + piece + " from " + peer);
if (!done)
chk = state.getNextRequest();
}
// out of the lock
if (done) {
// Done!
// PeerState will call the listener (peer coord), who will
// check to see if the MagnetState has it
if (log.shouldLog(Log.WARN))
log.warn("Got last chunk from " + peer);
} else {
// get the next chunk
if (log.shouldLog(Log.INFO))
log.info("Request chunk " + chk + " from " + peer);
sendRequest(peer, chk);
}
} else if (type == TYPE_REJECT) {
if (log.shouldLog(Log.WARN))
log.warn("Got reject msg from " + peer);
peer.disconnect(false);
} else {
if (log.shouldLog(Log.WARN))
log.warn("Got unknown metadata msg from " + peer);
peer.disconnect(false);
}
} catch (Exception e) {
if (log.shouldLog(Log.INFO))
log.info("Metadata ext. msg. exception from " + peer, e);
// fatal ?
peer.disconnect(false);
}
}
private static void sendRequest(Peer peer, int piece) {
sendMessage(peer, TYPE_REQUEST, piece);
}
/****
private static void sendReject(Peer peer, int piece) {
sendMessage(peer, TYPE_REJECT, piece);
}
****/
/** REQUEST and REJECT are the same except for message type */
private static void sendMessage(Peer peer, int type, int piece) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("msg_type", Integer.valueOf(type));
map.put("piece", Integer.valueOf(piece));
byte[] payload = BEncoder.bencode(map);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_METADATA).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no metadata capability
//if (log.shouldLog(Log.INFO))
// log.info("Metadata send req msg exception to " + peer, e);
}
}
private static void sendPiece(Peer peer, int piece, byte[] data, int totalSize) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("msg_type", Integer.valueOf(TYPE_DATA));
map.put("piece", Integer.valueOf(piece));
// BEP 9
// "This key has the same semantics as the 'metadata_size' in the extension header"
// which apparently means the same value. Fixed in 0.9.21.
//map.put("total_size", Integer.valueOf(data.length));
map.put("total_size", Integer.valueOf(totalSize));
byte[] dict = BEncoder.bencode(map);
byte[] payload = new byte[dict.length + data.length];
System.arraycopy(dict, 0, payload, 0, dict.length);
System.arraycopy(data, 0, payload, dict.length, data.length);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_METADATA).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no metadata caps
//if (log.shouldLog(Log.INFO))
// log.info("Metadata send piece msg exception to " + peer, e);
}
}
private static final int HASH_LENGTH = 32;
/**
* Can't find a published standard for this anywhere.
* See the libtorrent code.
* Here we use the "added" key as a single string of concatenated
* 32-byte peer hashes.
* added.f and dropped unsupported
* @since 0.8.4
*/
private static void handlePEX(Peer peer, PeerListener listener, byte[] bs, Log log) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got PEX msg from " + peer);
try {
InputStream is = new ByteArrayInputStream(bs);
BDecoder dec = new BDecoder(is);
BEValue bev = dec.bdecodeMap();
Map<String, BEValue> map = bev.getMap();
bev = map.get("added");
if (bev == null)
return;
byte[] ids = bev.getBytes();
if (ids.length < HASH_LENGTH)
return;
int len = Math.min(ids.length, (I2PSnarkUtil.MAX_CONNECTIONS - 1) * HASH_LENGTH);
List<PeerID> peers = new ArrayList<PeerID>(len / HASH_LENGTH);
for (int off = 0; off < len; off += HASH_LENGTH) {
byte[] hash = new byte[HASH_LENGTH];
System.arraycopy(ids, off, hash, 0, HASH_LENGTH);
if (DataHelper.eq(hash, peer.getPeerID().getDestHash()))
continue;
PeerID pID = new PeerID(hash, listener.getUtil());
peers.add(pID);
}
// could include ourselves, listener must remove
listener.gotPeers(peer, peers);
} catch (Exception e) {
if (log.shouldLog(Log.INFO))
log.info("PEX msg exception from " + peer, e);
//peer.disconnect(false);
}
}
/**
* Receive the DHT port numbers
* @since DHT
*/
private static void handleDHT(Peer peer, PeerListener listener, byte[] bs, Log log) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got DHT msg from " + peer);
try {
InputStream is = new ByteArrayInputStream(bs);
BDecoder dec = new BDecoder(is);
BEValue bev = dec.bdecodeMap();
Map<String, BEValue> map = bev.getMap();
int qport = map.get("port").getInt();
int rport = map.get("rport").getInt();
listener.gotPort(peer, qport, rport);
} catch (Exception e) {
if (log.shouldLog(Log.INFO))
log.info("DHT msg exception from " + peer, e);
//peer.disconnect(false);
}
}
/**
* added.f and dropped unsupported
* @param pList non-null
* @since 0.8.4
*/
public static void sendPEX(Peer peer, List<Peer> pList) {
if (pList.isEmpty())
return;
Map<String, Object> map = new HashMap<String, Object>();
byte[] peers = new byte[HASH_LENGTH * pList.size()];
int off = 0;
for (Peer p : pList) {
System.arraycopy(p.getPeerID().getDestHash(), 0, peers, off, HASH_LENGTH);
off += HASH_LENGTH;
}
map.put("added", peers);
byte[] payload = BEncoder.bencode(map);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_PEX).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no PEX caps
//if (log.shouldLog(Log.INFO))
// log.info("PEX msg exception to " + peer, e);
}
}
/**
* Send the DHT port numbers
* @since DHT
*/
public static void sendDHT(Peer peer, int qport, int rport) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("port", Integer.valueOf(qport));
map.put("rport", Integer.valueOf(rport));
byte[] payload = BEncoder.bencode(map);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_DHT).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no DHT caps
//if (log.shouldLog(Log.INFO))
// log.info("DHT msg exception to " + peer, e);
}
}
/**
* Handle comment request and response
*
* Ref: https://blinkenlights.ch/ccms/software/bittorrent.html
* Ref: https://github.com/adrian-bl/bitflu/blob/3cb7fe887dbdea8132e4fa36fbbf5f26cf992db3/plugins/Bitflu/20_DownloadBitTorrent.pm#L3403
* @since 0.9.31
*/
private static void handleComment(Peer peer, PeerListener listener, byte[] bs, Log log) {
if (log.shouldLog(Log.DEBUG))
log.debug("Got comment msg from " + peer);
try {
InputStream is = new ByteArrayInputStream(bs);
BDecoder dec = new BDecoder(is);
BEValue bev = dec.bdecodeMap();
Map<String, BEValue> map = bev.getMap();
int type = map.get("msg_type").getInt();
if (type == 0) {
// request
int num = 20;
BEValue b = map.get("num");
if (b != null)
num = b.getInt();
listener.gotCommentReq(peer, num);
} else if (type == 1) {
// response
List<BEValue> list = map.get("comments").getList();
if (list.isEmpty())
return;
List<Comment> comments = new ArrayList<Comment>(list.size());
long now = I2PAppContext.getGlobalContext().clock().now();
for (BEValue li : list) {
Map<String, BEValue> m = li.getMap();
String owner = m.get("owner").getString();
String text = m.get("text").getString();
int rating = m.get("like").getInt();
long time = now - (Math.max(0, m.get("timestamp").getInt()) * 1000L);
Comment c = new Comment(text, owner, rating, time, false);
comments.add(c);
}
listener.gotComments(peer, comments);
} else {
if (log.shouldLog(Log.INFO))
log.info("Unknown comment msg type " + type + " from " + peer);
}
} catch (Exception e) {
if (log.shouldLog(Log.INFO))
log.info("Comment msg exception from " + peer, e);
//peer.disconnect(false);
}
}
private static final byte[] COMMENTS_FILTER = new byte[64];
/**
* Send comment request
* @since 0.9.31
*/
public static void sendCommentReq(Peer peer, int num) {
Map<String, Object> map = new HashMap<String, Object>();
map.put("msg_type", Integer.valueOf(0));
map.put("num", Integer.valueOf(num));
map.put("filter", COMMENTS_FILTER);
byte[] payload = BEncoder.bencode(map);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_COMMENT).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no caps
}
}
/**
* Send comments
* Caller must sync on comments
* @param num max to send
* @param comments non-null
* @since 0.9.31
*/
public static void locked_sendComments(Peer peer, int num, CommentSet comments) {
int toSend = Math.min(num, comments.size());
if (toSend <= 0)
return;
Map<String, Object> map = new HashMap<String, Object>();
map.put("msg_type", Integer.valueOf(1));
List<Object> lc = new ArrayList<Object>(toSend);
long now = I2PAppContext.getGlobalContext().clock().now();
int i = 0;
for (Comment c : comments) {
if (i++ >= toSend)
break;
Map<String, Object> mc = new HashMap<String, Object>();
String s = c.getName();
mc.put("owner", s != null ? s : "");
s = c.getText();
mc.put("text", s != null ? s : "");
mc.put("like", Integer.valueOf(c.getRating()));
mc.put("timestamp", Long.valueOf((now - c.getTime()) / 1000L));
lc.add(mc);
}
map.put("comments", lc);
byte[] payload = BEncoder.bencode(map);
try {
int hisMsgCode = peer.getHandshakeMap().get("m").getMap().get(TYPE_COMMENT).getInt();
peer.sendExtension(hisMsgCode, payload);
} catch (Exception e) {
// NPE, no caps
}
}
}