/*
* Copyright (c) 2010 Yahoo! Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific
* language governing permissions and limitations under the
* License. See accompanying LICENSE file.
*/
package io.s4.client;
import io.s4.client.ClientStub.Info;
import io.s4.util.ByteArrayIOChannel;
import java.io.IOException;
import java.net.Socket;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;
import org.apache.log4j.Logger;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.google.gson.Gson;
public class Handshake {
private final ClientStub clientStub;
protected static final Logger logger = Logger.getLogger("adapter");
protected final Gson gson = new Gson();
public Handshake(ClientStub clientStub) {
this.clientStub = clientStub;
}
// execute handshake with client.
// 1. discovery: issue uuid;
// 2. main connect: create connection
public ClientConnection execute(Socket s) {
byte[] v;
try {
ClientConnection conn = null;
ByteArrayIOChannel io = new ByteArrayIOChannel(s);
v = io.recv();
if (v == null || v.length == 0) {
// no information => client initialization
clientInit(io);
} else {
// some data => client connect
conn = clientConnect(v, io, s);
}
if (conn == null)
s.close();
return conn;
} catch (IOException e) {
logger.error("exception during handshake", e);
try {
s.close();
return null;
} catch (IOException ee) {
throw new RuntimeException("failed to close socket after failed handshake",
ee);
}
}
}
private ClientConnection clientConnect(byte[] v, ByteArrayIOChannel io,
Socket sock) throws IOException {
List<String> reason = new ArrayList<String>(1);
ClientConnection conn = clientConnectCreate(v, io, sock, reason);
String message = null;
try {
JSONObject resp = new JSONObject();
resp.put("status", (conn != null ? "ok" : "failed"));
if (conn == null && !reason.isEmpty()) {
resp.put("reason", reason.get(0));
}
message = resp.toString();
} catch (JSONException e) {
logger.error("error creating response during connect.", e);
return null;
}
io.send(message.getBytes());
return conn;
}
private ClientConnection clientConnectCreate(byte[] v,
ByteArrayIOChannel io,
Socket sock,
List<String> reason)
throws IOException {
try {
JSONObject cInfo = new JSONObject(new String(v));
String s = cInfo.optString("uuid", "");
if (s.isEmpty()) {
logger.error("missing client identifier during handshake.");
reason.add("missing UUID");
return null;
}
UUID u = UUID.fromString(s);
logger.info("connecting to client " + u);
s = cInfo.optString("readMode", "Private");
ClientReadMode rmode = ClientReadMode.fromString(s);
if (rmode == null) {
logger.error(u + ": unknown readMode " + s);
reason.add("unknown readMode " + s);
return null;
}
s = cInfo.optString("writeMode", "Enabled");
ClientWriteMode wmode = ClientWriteMode.fromString(s);
if (wmode == null) {
logger.error(u + ": unknown writeMode " + s);
reason.add("unknown writeMode " + s);
return null;
}
logger.info(u + " read=" + rmode + " write=" + wmode);
if (rmode == ClientReadMode.None
&& wmode == ClientWriteMode.Disabled) {
// client cannot disable read AND write...
logger.error("client neither reads nor writes.");
reason.add("read and write disabled");
return null;
}
ClientConnection conn = new ClientConnection(clientStub, sock, u, rmode, wmode);
if (rmode == ClientReadMode.Select) {
JSONArray incl = cInfo.optJSONArray("readInclude");
JSONArray excl = cInfo.optJSONArray("readExclude");
if (incl == null && excl == null) {
logger.error(u + ": missing stream selection information");
reason.add("missing readInclude and readExclude");
return null;
}
if (incl != null) {
List<String> streams = new ArrayList<String>(incl.length());
for (int i = 0; i < incl.length(); ++i)
streams.add(incl.getString(i));
conn.includeStreams(streams);
}
if (excl != null) {
List<String> streams = new ArrayList<String>(excl.length());
for (int i = 0; i < excl.length(); ++i)
streams.add(excl.getString(i));
conn.excludeStreams(streams);
}
}
return conn;
} catch (JSONException e) {
logger.error("malformed JSON from client during handshake", e);
reason.add("malformed JSON");
} catch (NumberFormatException e) {
logger.error("received malformed UUID", e);
reason.add("malformed UUID");
} catch (IllegalArgumentException e) {
logger.error("received malformed UUID", e);
reason.add("malformed UUID");
}
return null;
}
private void clientInit(ByteArrayIOChannel io) throws IOException {
String uuid = UUID.randomUUID().toString();
Info proto = clientStub.getProtocolInfo();
HashMap<String, Object> info = new HashMap<String, Object>();
info.put("uuid", uuid);
info.put("protocol", proto);
String response = gson.toJson(info) + "\n";
io.send(response.getBytes());
}
}