2 * Copyright (C) 2015-2016 EfficiOS Inc., Alexandre Montplaisir <alexmonthy@efficios.com>
3 * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com>
5 * This library is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU Lesser General Public License, version 2.1 only,
7 * as published by the Free Software Foundation.
9 * This library is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
14 * You should have received a copy of the GNU Lesser General Public License
15 * along with this library; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 package org
.lttng
.ust
.agent
.client
;
21 import java
.io
.BufferedReader
;
22 import java
.io
.DataInputStream
;
23 import java
.io
.DataOutputStream
;
24 import java
.io
.FileNotFoundException
;
25 import java
.io
.FileReader
;
26 import java
.io
.IOException
;
27 import java
.lang
.management
.ManagementFactory
;
28 import java
.net
.Socket
;
29 import java
.net
.UnknownHostException
;
30 import java
.nio
.ByteBuffer
;
31 import java
.nio
.ByteOrder
;
32 import java
.util
.concurrent
.CountDownLatch
;
33 import java
.util
.concurrent
.TimeUnit
;
35 import org
.lttng
.ust
.agent
.utils
.LttngUstAgentLogger
;
38 * Client for agents to connect to a local session daemon, using a TCP socket.
40 * @author David Goulet
42 public class LttngTcpSessiondClient
implements Runnable
{
44 private static final String SESSION_HOST
= "127.0.0.1";
45 private static final String ROOT_PORT_FILE
= "/var/run/lttng/agent.port";
46 private static final String USER_PORT_FILE
= "/.lttng/agent.port";
48 private static final int PROTOCOL_MAJOR_VERSION
= 2;
49 private static final int PROTOCOL_MINOR_VERSION
= 0;
51 /** Command header from the session deamon. */
52 private final CountDownLatch registrationLatch
= new CountDownLatch(1);
54 private Socket sessiondSock
;
55 private volatile boolean quit
= false;
57 private DataInputStream inFromSessiond
;
58 private DataOutputStream outToSessiond
;
60 private final ILttngTcpClientListener logAgent
;
61 private final int domainValue
;
62 private final boolean isRoot
;
68 * The listener this client will operate on, typically an LTTng
71 * The integer to send to the session daemon representing the
72 * tracing domain to handle.
74 * True if this client should connect to the root session daemon,
75 * false if it should connect to the user one.
77 public LttngTcpSessiondClient(ILttngTcpClientListener logAgent
, int domainValue
, boolean isRoot
) {
78 this.logAgent
= logAgent
;
79 this.domainValue
= domainValue
;
84 * Wait until this client has successfully established a connection to its
85 * target session daemon.
88 * A timeout in seconds after which this method will return
90 * @return True if the the client actually established the connection, false
91 * if we returned because the timeout has elapsed or the thread was
94 public boolean waitForConnection(int seconds
) {
96 return registrationLatch
.await(seconds
, TimeUnit
.SECONDS
);
97 } catch (InterruptedException e
) {
112 * Connect to the session daemon before anything else.
114 LttngUstAgentLogger
.log(getClass(), "Connecting to sessiond");
118 * Register to the session daemon as the Java component of the
121 LttngUstAgentLogger
.log(getClass(), "Registering to sessiond");
122 registerToSessiond();
125 * Block on socket receive and wait for command from the
126 * session daemon. This will return if and only if there is a
127 * fatal error or the socket closes.
129 LttngUstAgentLogger
.log(getClass(), "Waiting on sessiond commands...");
131 } catch (UnknownHostException uhe
) {
132 uhe
.printStackTrace();
133 } catch (IOException ioe
) {
136 } catch (InterruptedException e
) {
144 * Dispose this client and close any socket connection it may hold.
146 public void close() {
147 LttngUstAgentLogger
.log(getClass(), "Closing client");
151 if (this.sessiondSock
!= null) {
152 this.sessiondSock
.close();
154 } catch (IOException e
) {
159 private void connectToSessiond() throws IOException
{
163 port
= getPortFromFile(ROOT_PORT_FILE
);
165 /* No session daemon available. Stop and retry later. */
166 throw new IOException();
169 port
= getPortFromFile(getHomePath() + USER_PORT_FILE
);
171 /* No session daemon available. Stop and retry later. */
172 throw new IOException();
176 this.sessiondSock
= new Socket(SESSION_HOST
, port
);
177 this.inFromSessiond
= new DataInputStream(sessiondSock
.getInputStream());
178 this.outToSessiond
= new DataOutputStream(sessiondSock
.getOutputStream());
181 private static String
getHomePath() {
182 return System
.getProperty("user.home");
186 * Read port number from file created by the session daemon.
188 * @return port value if found else 0.
190 private static int getPortFromFile(String path
) throws IOException
{
192 BufferedReader br
= null;
195 br
= new BufferedReader(new FileReader(path
));
196 String line
= br
.readLine();
197 port
= Integer
.parseInt(line
, 10);
198 if (port
< 0 || port
> 65535) {
199 /* Invalid value. Ignore. */
202 } catch (FileNotFoundException e
) {
203 /* No port available. */
214 private void registerToSessiond() throws IOException
{
215 byte data
[] = new byte[16];
216 ByteBuffer buf
= ByteBuffer
.wrap(data
);
217 String pid
= ManagementFactory
.getRuntimeMXBean().getName().split("@")[0];
219 buf
.putInt(domainValue
);
220 buf
.putInt(Integer
.parseInt(pid
));
221 buf
.putInt(PROTOCOL_MAJOR_VERSION
);
222 buf
.putInt(PROTOCOL_MINOR_VERSION
);
223 this.outToSessiond
.write(data
, 0, data
.length
);
224 this.outToSessiond
.flush();
228 * Handle session command from the session daemon.
230 private void handleSessiondCmd() throws IOException
{
231 /* Data read from the socket */
232 byte inputData
[] = null;
233 /* Reply data written to the socket, sent to the sessiond */
234 byte responseData
[] = null;
237 /* Get header from session daemon. */
238 SessiondCommandHeader cmdHeader
= recvHeader();
240 if (cmdHeader
.getDataSize() > 0) {
241 inputData
= recvPayload(cmdHeader
);
244 switch (cmdHeader
.getCommandType()) {
248 * Countdown the registration latch, meaning registration is
249 * done and we can proceed to continue tracing.
251 registrationLatch
.countDown();
253 * We don't send any reply to the registration done command.
254 * This just marks the end of the initial session setup.
256 LttngUstAgentLogger
.log(getClass(), "Registration done");
261 SessiondCommand listLoggerCmd
= new SessiondListLoggersCommand();
262 LttngAgentResponse response
= listLoggerCmd
.execute(logAgent
);
263 responseData
= response
.getBytes();
264 LttngUstAgentLogger
.log(getClass(), "Received list loggers command");
267 case CMD_EVENT_ENABLE
:
269 if (inputData
== null) {
270 /* Invalid command */
271 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
274 SessiondCommand enableEventCmd
= new SessiondEnableEventCommand(inputData
);
275 LttngAgentResponse response
= enableEventCmd
.execute(logAgent
);
276 responseData
= response
.getBytes();
277 LttngUstAgentLogger
.log(getClass(), "Received enable event command");
280 case CMD_EVENT_DISABLE
:
282 if (inputData
== null) {
283 /* Invalid command */
284 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
287 SessiondCommand disableEventCmd
= new SessiondDisableEventCommand(inputData
);
288 LttngAgentResponse response
= disableEventCmd
.execute(logAgent
);
289 responseData
= response
.getBytes();
290 LttngUstAgentLogger
.log(getClass(), "Received disable event command");
293 case CMD_APP_CTX_ENABLE
:
295 if (inputData
== null) {
296 /* This commands expects a payload, invalid command */
297 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
300 SessiondCommand enableAppCtxCmd
= new SessiondEnableAppContextCommand(inputData
);
301 LttngAgentResponse response
= enableAppCtxCmd
.execute(logAgent
);
302 responseData
= response
.getBytes();
303 LttngUstAgentLogger
.log(getClass(), "Received enable app-context command");
306 case CMD_APP_CTX_DISABLE
:
308 if (inputData
== null) {
309 /* This commands expects a payload, invalid command */
310 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
313 SessiondCommand disableAppCtxCmd
= new SessiondDisableAppContextCommand(inputData
);
314 LttngAgentResponse response
= disableAppCtxCmd
.execute(logAgent
);
315 responseData
= response
.getBytes();
316 LttngUstAgentLogger
.log(getClass(), "Received disable app-context command");
321 /* Unknown command, send empty reply */
322 responseData
= new byte[4];
323 ByteBuffer buf
= ByteBuffer
.wrap(responseData
);
324 buf
.order(ByteOrder
.BIG_ENDIAN
);
325 LttngUstAgentLogger
.log(getClass(), "Received unknown command, ignoring");
330 /* Send response to the session daemon. */
331 LttngUstAgentLogger
.log(getClass(), "Sending response");
332 this.outToSessiond
.write(responseData
, 0, responseData
.length
);
333 this.outToSessiond
.flush();
338 * Receive header data from the session daemon using the LTTng command
339 * static buffer of the right size.
341 private SessiondCommandHeader
recvHeader() throws IOException
{
342 byte data
[] = new byte[SessiondCommandHeader
.HEADER_SIZE
];
344 int readLen
= this.inFromSessiond
.read(data
, 0, data
.length
);
345 if (readLen
!= data
.length
) {
346 throw new IOException();
348 return new SessiondCommandHeader(data
);
352 * Receive payload from the session daemon. This MUST be done after a
353 * recvHeader() so the header value of a command are known.
355 * The caller SHOULD use isPayload() before which returns true if a payload
356 * is expected after the header.
358 private byte[] recvPayload(SessiondCommandHeader headerCmd
) throws IOException
{
359 byte payload
[] = new byte[(int) headerCmd
.getDataSize()];
361 /* Failsafe check so we don't waste our time reading 0 bytes. */
362 if (payload
.length
== 0) {
366 this.inFromSessiond
.read(payload
, 0, payload
.length
);