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() {
183 * The environment variable LTTNG_HOME overrides HOME if
186 String homePath
= System
.getenv("LTTNG_HOME");
188 if (homePath
== null) {
189 homePath
= System
.getProperty("user.home");
195 * Read port number from file created by the session daemon.
197 * @return port value if found else 0.
199 private static int getPortFromFile(String path
) throws IOException
{
201 BufferedReader br
= null;
204 br
= new BufferedReader(new FileReader(path
));
205 String line
= br
.readLine();
206 port
= Integer
.parseInt(line
, 10);
207 if (port
< 0 || port
> 65535) {
208 /* Invalid value. Ignore. */
211 } catch (FileNotFoundException e
) {
212 /* No port available. */
223 private void registerToSessiond() throws IOException
{
224 byte data
[] = new byte[16];
225 ByteBuffer buf
= ByteBuffer
.wrap(data
);
226 String pid
= ManagementFactory
.getRuntimeMXBean().getName().split("@")[0];
228 buf
.putInt(domainValue
);
229 buf
.putInt(Integer
.parseInt(pid
));
230 buf
.putInt(PROTOCOL_MAJOR_VERSION
);
231 buf
.putInt(PROTOCOL_MINOR_VERSION
);
232 this.outToSessiond
.write(data
, 0, data
.length
);
233 this.outToSessiond
.flush();
237 * Handle session command from the session daemon.
239 private void handleSessiondCmd() throws IOException
{
240 /* Data read from the socket */
241 byte inputData
[] = null;
242 /* Reply data written to the socket, sent to the sessiond */
243 byte responseData
[] = null;
246 /* Get header from session daemon. */
247 SessiondCommandHeader cmdHeader
= recvHeader();
249 if (cmdHeader
.getDataSize() > 0) {
250 inputData
= recvPayload(cmdHeader
);
253 switch (cmdHeader
.getCommandType()) {
257 * Countdown the registration latch, meaning registration is
258 * done and we can proceed to continue tracing.
260 registrationLatch
.countDown();
262 * We don't send any reply to the registration done command.
263 * This just marks the end of the initial session setup.
265 LttngUstAgentLogger
.log(getClass(), "Registration done");
270 SessiondCommand listLoggerCmd
= new SessiondListLoggersCommand();
271 LttngAgentResponse response
= listLoggerCmd
.execute(logAgent
);
272 responseData
= response
.getBytes();
273 LttngUstAgentLogger
.log(getClass(), "Received list loggers command");
276 case CMD_EVENT_ENABLE
:
278 if (inputData
== null) {
279 /* Invalid command */
280 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
283 SessiondCommand enableEventCmd
= new SessiondEnableEventCommand(inputData
);
284 LttngAgentResponse response
= enableEventCmd
.execute(logAgent
);
285 responseData
= response
.getBytes();
286 LttngUstAgentLogger
.log(getClass(), "Received enable event command");
289 case CMD_EVENT_DISABLE
:
291 if (inputData
== null) {
292 /* Invalid command */
293 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
296 SessiondCommand disableEventCmd
= new SessiondDisableEventCommand(inputData
);
297 LttngAgentResponse response
= disableEventCmd
.execute(logAgent
);
298 responseData
= response
.getBytes();
299 LttngUstAgentLogger
.log(getClass(), "Received disable event command");
302 case CMD_APP_CTX_ENABLE
:
304 if (inputData
== null) {
305 /* This commands expects a payload, invalid command */
306 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
309 SessiondCommand enableAppCtxCmd
= new SessiondEnableAppContextCommand(inputData
);
310 LttngAgentResponse response
= enableAppCtxCmd
.execute(logAgent
);
311 responseData
= response
.getBytes();
312 LttngUstAgentLogger
.log(getClass(), "Received enable app-context command");
315 case CMD_APP_CTX_DISABLE
:
317 if (inputData
== null) {
318 /* This commands expects a payload, invalid command */
319 responseData
= LttngAgentResponse
.FAILURE_RESPONSE
.getBytes();
322 SessiondCommand disableAppCtxCmd
= new SessiondDisableAppContextCommand(inputData
);
323 LttngAgentResponse response
= disableAppCtxCmd
.execute(logAgent
);
324 responseData
= response
.getBytes();
325 LttngUstAgentLogger
.log(getClass(), "Received disable app-context command");
330 /* Unknown command, send empty reply */
331 responseData
= new byte[4];
332 ByteBuffer buf
= ByteBuffer
.wrap(responseData
);
333 buf
.order(ByteOrder
.BIG_ENDIAN
);
334 LttngUstAgentLogger
.log(getClass(), "Received unknown command, ignoring");
339 /* Send response to the session daemon. */
340 LttngUstAgentLogger
.log(getClass(), "Sending response");
341 this.outToSessiond
.write(responseData
, 0, responseData
.length
);
342 this.outToSessiond
.flush();
347 * Receive header data from the session daemon using the LTTng command
348 * static buffer of the right size.
350 private SessiondCommandHeader
recvHeader() throws IOException
{
351 byte data
[] = new byte[SessiondCommandHeader
.HEADER_SIZE
];
353 int readLen
= this.inFromSessiond
.read(data
, 0, data
.length
);
354 if (readLen
!= data
.length
) {
355 throw new IOException();
357 return new SessiondCommandHeader(data
);
361 * Receive payload from the session daemon. This MUST be done after a
362 * recvHeader() so the header value of a command are known.
364 * The caller SHOULD use isPayload() before which returns true if a payload
365 * is expected after the header.
367 private byte[] recvPayload(SessiondCommandHeader headerCmd
) throws IOException
{
368 byte payload
[] = new byte[(int) headerCmd
.getDataSize()];
370 /* Failsafe check so we don't waste our time reading 0 bytes. */
371 if (payload
.length
== 0) {
375 this.inFromSessiond
.read(payload
, 0, payload
.length
);