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
;
36 * Client for agents to connect to a local session daemon, using a TCP socket.
38 * @author David Goulet
40 public class LttngTcpSessiondClient
implements Runnable
{
42 private static final String SESSION_HOST
= "127.0.0.1";
43 private static final String ROOT_PORT_FILE
= "/var/run/lttng/agent.port";
44 private static final String USER_PORT_FILE
= "/.lttng/agent.port";
46 private static final int PROTOCOL_MAJOR_VERSION
= 2;
47 private static final int PROTOCOL_MINOR_VERSION
= 0;
49 /** Command header from the session deamon. */
50 private final CountDownLatch registrationLatch
= new CountDownLatch(1);
52 private Socket sessiondSock
;
53 private volatile boolean quit
= false;
55 private DataInputStream inFromSessiond
;
56 private DataOutputStream outToSessiond
;
58 private final ILttngTcpClientListener logAgent
;
59 private final int domainValue
;
60 private final boolean isRoot
;
66 * The listener this client will operate on, typically an LTTng
69 * The integer to send to the session daemon representing the
70 * tracing domain to handle.
72 * True if this client should connect to the root session daemon,
73 * false if it should connect to the user one.
75 public LttngTcpSessiondClient(ILttngTcpClientListener logAgent
, int domainValue
, boolean isRoot
) {
76 this.logAgent
= logAgent
;
77 this.domainValue
= domainValue
;
82 * Wait until this client has successfully established a connection to its
83 * target session daemon.
86 * A timeout in seconds after which this method will return
88 * @return True if the the client actually established the connection, false
89 * if we returned because the timeout has elapsed or the thread was
92 public boolean waitForConnection(int seconds
) {
94 return registrationLatch
.await(seconds
, TimeUnit
.SECONDS
);
95 } catch (InterruptedException e
) {
110 * Connect to the session daemon before anything else.
115 * Register to the session daemon as the Java component of the
118 registerToSessiond();
121 * Block on socket receive and wait for command from the
122 * session daemon. This will return if and only if there is a
123 * fatal error or the socket closes.
126 } catch (UnknownHostException uhe
) {
127 uhe
.printStackTrace();
128 } catch (IOException ioe
) {
131 } catch (InterruptedException e
) {
139 * Dispose this client and close any socket connection it may hold.
141 public void close() {
145 if (this.sessiondSock
!= null) {
146 this.sessiondSock
.close();
148 } catch (IOException e
) {
153 private void connectToSessiond() throws IOException
{
157 port
= getPortFromFile(ROOT_PORT_FILE
);
159 /* No session daemon available. Stop and retry later. */
160 throw new IOException();
163 port
= getPortFromFile(getHomePath() + USER_PORT_FILE
);
165 /* No session daemon available. Stop and retry later. */
166 throw new IOException();
170 this.sessiondSock
= new Socket(SESSION_HOST
, port
);
171 this.inFromSessiond
= new DataInputStream(sessiondSock
.getInputStream());
172 this.outToSessiond
= new DataOutputStream(sessiondSock
.getOutputStream());
175 private static String
getHomePath() {
176 return System
.getProperty("user.home");
180 * Read port number from file created by the session daemon.
182 * @return port value if found else 0.
184 private static int getPortFromFile(String path
) throws IOException
{
186 BufferedReader br
= null;
189 br
= new BufferedReader(new FileReader(path
));
190 String line
= br
.readLine();
191 port
= Integer
.parseInt(line
, 10);
192 if (port
< 0 || port
> 65535) {
193 /* Invalid value. Ignore. */
196 } catch (FileNotFoundException e
) {
197 /* No port available. */
208 private void registerToSessiond() throws IOException
{
209 byte data
[] = new byte[16];
210 ByteBuffer buf
= ByteBuffer
.wrap(data
);
211 String pid
= ManagementFactory
.getRuntimeMXBean().getName().split("@")[0];
213 buf
.putInt(domainValue
);
214 buf
.putInt(Integer
.parseInt(pid
));
215 buf
.putInt(PROTOCOL_MAJOR_VERSION
);
216 buf
.putInt(PROTOCOL_MINOR_VERSION
);
217 this.outToSessiond
.write(data
, 0, data
.length
);
218 this.outToSessiond
.flush();
222 * Handle session command from the session daemon.
224 private void handleSessiondCmd() throws IOException
{
225 /* Data read from the socket */
226 byte inputData
[] = null;
227 /* Reply data written to the socket, sent to the sessiond */
228 byte responseData
[] = null;
231 /* Get header from session daemon. */
232 SessiondCommandHeader cmdHeader
= recvHeader();
234 if (cmdHeader
.getDataSize() > 0) {
235 inputData
= recvPayload(cmdHeader
);
238 switch (cmdHeader
.getCommandType()) {
242 * Countdown the registration latch, meaning registration is
243 * done and we can proceed to continue tracing.
245 registrationLatch
.countDown();
247 * We don't send any reply to the registration done command.
248 * This just marks the end of the initial session setup.
254 SessiondCommand listLoggerCmd
= new SessiondListLoggersCommand();
255 LttngAgentResponse response
= listLoggerCmd
.execute(logAgent
);
256 responseData
= response
.getBytes();
259 case CMD_EVENT_ENABLE
:
261 if (inputData
== null) {
262 /* Invalid command */
263 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
266 SessiondCommand enableEventCmd
= new SessiondEnableEventCommand(inputData
);
267 LttngAgentResponse response
= enableEventCmd
.execute(logAgent
);
268 responseData
= response
.getBytes();
271 case CMD_EVENT_DISABLE
:
273 if (inputData
== null) {
274 /* Invalid command */
275 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
278 SessiondCommand disableEventCmd
= new SessiondDisableEventCommand(inputData
);
279 LttngAgentResponse response
= disableEventCmd
.execute(logAgent
);
280 responseData
= response
.getBytes();
283 case CMD_APP_CTX_ENABLE
:
285 if (inputData
== null) {
286 /* This commands expects a payload, invalid command */
287 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
290 SessiondCommand enableAppCtxCmd
= new SessiondEnableAppContextCommand(inputData
);
291 LttngAgentResponse response
= enableAppCtxCmd
.execute(logAgent
);
292 responseData
= response
.getBytes();
295 case CMD_APP_CTX_DISABLE
:
297 if (inputData
== null) {
298 /* This commands expects a payload, invalid command */
299 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
302 SessiondCommand disableAppCtxCmd
= new SessiondDisableAppContextCommand(inputData
);
303 LttngAgentResponse response
= disableAppCtxCmd
.execute(logAgent
);
304 responseData
= response
.getBytes();
309 /* Unknown command, send empty reply */
310 responseData
= new byte[4];
311 ByteBuffer buf
= ByteBuffer
.wrap(responseData
);
312 buf
.order(ByteOrder
.BIG_ENDIAN
);
317 /* Send response to the session daemon. */
318 this.outToSessiond
.write(responseData
, 0, responseData
.length
);
319 this.outToSessiond
.flush();
324 * Receive header data from the session daemon using the LTTng command
325 * static buffer of the right size.
327 private SessiondCommandHeader
recvHeader() throws IOException
{
328 byte data
[] = new byte[SessiondCommandHeader
.HEADER_SIZE
];
330 int readLen
= this.inFromSessiond
.read(data
, 0, data
.length
);
331 if (readLen
!= data
.length
) {
332 throw new IOException();
334 return new SessiondCommandHeader(data
);
338 * Receive payload from the session daemon. This MUST be done after a
339 * recvHeader() so the header value of a command are known.
341 * The caller SHOULD use isPayload() before which returns true if a payload
342 * is expected after the header.
344 private byte[] recvPayload(SessiondCommandHeader headerCmd
) throws IOException
{
345 byte payload
[] = new byte[(int) headerCmd
.getDataSize()];
347 /* Failsafe check so we don't waste our time reading 0 bytes. */
348 if (payload
.length
== 0) {
352 this.inFromSessiond
.read(payload
, 0, payload
.length
);