/**
* 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);
}
}
/**
* 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);
}
}