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43e5396b DG |
1 | /* |
2 | * Copyright (C) 2013 - David Goulet <dgoulet@efficios.com> | |
3 | * | |
4 | * This library is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, | |
6 | * as published by the Free Software Foundation. | |
7 | * | |
8 | * This library is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License | |
11 | * for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU Lesser General Public License | |
14 | * along with this library; if not, write to the Free Software Foundation, | |
15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
16 | */ | |
17 | ||
d60dfbe4 | 18 | package org.lttng.ust.agent.client; |
43e5396b | 19 | |
f1fa0535 | 20 | import java.io.BufferedReader; |
43e5396b | 21 | import java.io.DataInputStream; |
bc7de6d9 | 22 | import java.io.DataOutputStream; |
f1fa0535 | 23 | import java.io.FileNotFoundException; |
bc7de6d9 AM |
24 | import java.io.FileReader; |
25 | import java.io.IOException; | |
43e5396b | 26 | import java.lang.management.ManagementFactory; |
bc7de6d9 AM |
27 | import java.net.Socket; |
28 | import java.net.UnknownHostException; | |
29 | import java.nio.ByteBuffer; | |
30 | import java.nio.ByteOrder; | |
d60dfbe4 AM |
31 | import java.util.concurrent.CountDownLatch; |
32 | import java.util.concurrent.TimeUnit; | |
43e5396b | 33 | |
d60dfbe4 AM |
34 | import org.lttng.ust.agent.AbstractLttngAgent; |
35 | ||
36 | /** | |
37 | * Client for agents to connect to a local session daemon, using a TCP socket. | |
38 | * | |
39 | * @author David Goulet | |
40 | */ | |
41 | public class LttngTcpSessiondClient implements Runnable { | |
43e5396b | 42 | |
08284556 AM |
43 | private static final String SESSION_HOST = "127.0.0.1"; |
44 | private static final String ROOT_PORT_FILE = "/var/run/lttng/agent.port"; | |
45 | private static final String USER_PORT_FILE = "/.lttng/agent.port"; | |
46 | ||
d60dfbe4 AM |
47 | private static int protocolMajorVersion = 1; |
48 | private static int protocolMinorVersion = 0; | |
08284556 | 49 | |
d60dfbe4 AM |
50 | /** Command header from the session deamon. */ |
51 | private final SessiondHeaderCommand headerCmd = new SessiondHeaderCommand(); | |
52 | private final CountDownLatch registrationLatch = new CountDownLatch(1); | |
43e5396b | 53 | |
43e5396b | 54 | private Socket sessiondSock; |
501f6777 | 55 | private volatile boolean quit = false; |
43e5396b DG |
56 | |
57 | private DataInputStream inFromSessiond; | |
58 | private DataOutputStream outToSessiond; | |
59 | ||
d60dfbe4 AM |
60 | private final AbstractLttngAgent<?> logAgent; |
61 | private final boolean isRoot; | |
501f6777 | 62 | |
f1fa0535 | 63 | |
d60dfbe4 AM |
64 | /** |
65 | * Constructor | |
66 | * | |
67 | * @param logAgent | |
68 | * The logging agent this client will operate on. | |
69 | * @param isRoot | |
70 | * True if this client should connect to the root session daemon, | |
71 | * false if it should connect to the user one. | |
72 | */ | |
73 | public LttngTcpSessiondClient(AbstractLttngAgent<?> logAgent, boolean isRoot) { | |
74 | this.logAgent = logAgent; | |
75 | this.isRoot = isRoot; | |
43e5396b DG |
76 | } |
77 | ||
d60dfbe4 AM |
78 | /** |
79 | * Wait until this client has successfully established a connection to its | |
80 | * target session daemon. | |
81 | * | |
82 | * @param seconds | |
83 | * A timeout in seconds after which this method will return | |
84 | * anyway. | |
85 | * @return True if the the client actually established the connection, false | |
86 | * if we returned because the timeout has elapsed or the thread was | |
87 | * interrupted. | |
f1fa0535 | 88 | */ |
d60dfbe4 AM |
89 | public boolean waitForConnection(int seconds) { |
90 | try { | |
91 | return registrationLatch.await(seconds, TimeUnit.SECONDS); | |
92 | } catch (InterruptedException e) { | |
93 | return false; | |
f1fa0535 DG |
94 | } |
95 | } | |
96 | ||
501f6777 CB |
97 | @Override |
98 | public void run() { | |
43e5396b DG |
99 | for (;;) { |
100 | if (this.quit) { | |
101 | break; | |
102 | } | |
103 | ||
104 | try { | |
105 | ||
106 | /* | |
107 | * Connect to the session daemon before anything else. | |
108 | */ | |
109 | connectToSessiond(); | |
110 | ||
111 | /* | |
112 | * Register to the session daemon as the Java component of the | |
113 | * UST application. | |
114 | */ | |
115 | registerToSessiond(); | |
43e5396b | 116 | |
43e5396b DG |
117 | /* |
118 | * Block on socket receive and wait for command from the | |
119 | * session daemon. This will return if and only if there is a | |
120 | * fatal error or the socket closes. | |
121 | */ | |
122 | handleSessiondCmd(); | |
123 | } catch (UnknownHostException uhe) { | |
d60dfbe4 | 124 | uhe.printStackTrace(); |
43e5396b | 125 | } catch (IOException ioe) { |
501f6777 CB |
126 | try { |
127 | Thread.sleep(3000); | |
128 | } catch (InterruptedException e) { | |
129 | e.printStackTrace(); | |
130 | } | |
43e5396b DG |
131 | } |
132 | } | |
133 | } | |
134 | ||
d60dfbe4 AM |
135 | /** |
136 | * Dispose this client and close any socket connection it may hold. | |
137 | */ | |
138 | public void close() { | |
43e5396b | 139 | this.quit = true; |
43e5396b DG |
140 | |
141 | try { | |
142 | if (this.sessiondSock != null) { | |
143 | this.sessiondSock.close(); | |
144 | } | |
d60dfbe4 | 145 | } catch (IOException e) { |
43e5396b DG |
146 | e.printStackTrace(); |
147 | } | |
148 | } | |
149 | ||
d60dfbe4 | 150 | /** |
43e5396b DG |
151 | * Receive header data from the session daemon using the LTTng command |
152 | * static buffer of the right size. | |
153 | */ | |
d60dfbe4 AM |
154 | private void recvHeader() throws IOException { |
155 | byte data[] = new byte[SessiondHeaderCommand.HEADER_SIZE]; | |
43e5396b | 156 | |
08284556 AM |
157 | int readLen = this.inFromSessiond.read(data, 0, data.length); |
158 | if (readLen != data.length) { | |
43e5396b DG |
159 | throw new IOException(); |
160 | } | |
161 | this.headerCmd.populate(data); | |
162 | } | |
163 | ||
d60dfbe4 | 164 | /** |
43e5396b DG |
165 | * Receive payload from the session daemon. This MUST be done after a |
166 | * recvHeader() so the header value of a command are known. | |
167 | * | |
168 | * The caller SHOULD use isPayload() before which returns true if a payload | |
169 | * is expected after the header. | |
170 | */ | |
d60dfbe4 AM |
171 | private byte[] recvPayload() throws IOException { |
172 | byte payload[] = new byte[(int) this.headerCmd.getDataSize()]; | |
43e5396b DG |
173 | |
174 | /* Failsafe check so we don't waste our time reading 0 bytes. */ | |
175 | if (payload.length == 0) { | |
176 | return null; | |
177 | } | |
178 | ||
179 | this.inFromSessiond.read(payload, 0, payload.length); | |
180 | return payload; | |
181 | } | |
182 | ||
d60dfbe4 | 183 | /** |
43e5396b DG |
184 | * Handle session command from the session daemon. |
185 | */ | |
d60dfbe4 | 186 | private void handleSessiondCmd() throws IOException { |
43e5396b DG |
187 | byte data[] = null; |
188 | ||
189 | while (true) { | |
190 | /* Get header from session daemon. */ | |
191 | recvHeader(); | |
192 | ||
d60dfbe4 | 193 | if (headerCmd.getDataSize() > 0) { |
43e5396b DG |
194 | data = recvPayload(); |
195 | } | |
196 | ||
d60dfbe4 AM |
197 | switch (headerCmd.getCommandType()) { |
198 | case CMD_REG_DONE: | |
199 | { | |
200 | /* | |
201 | * Countdown the registration latch, meaning registration is | |
202 | * done and we can proceed to continue tracing. | |
203 | */ | |
204 | registrationLatch.countDown(); | |
205 | /* | |
206 | * We don't send any reply to the registration done command. | |
207 | * This just marks the end of the initial session setup. | |
208 | */ | |
209 | continue; | |
210 | } | |
211 | case CMD_LIST: | |
212 | { | |
213 | SessiondListLoggersResponse listLoggerCmd = new SessiondListLoggersResponse(); | |
214 | listLoggerCmd.execute(logAgent); | |
215 | data = listLoggerCmd.getBytes(); | |
216 | break; | |
217 | } | |
218 | case CMD_ENABLE: | |
219 | { | |
220 | SessiondEnableHandler enableCmd = new SessiondEnableHandler(); | |
221 | if (data == null) { | |
222 | enableCmd.code = ISessiondResponse.LttngAgentRetCode.CODE_INVALID_CMD; | |
43e5396b DG |
223 | break; |
224 | } | |
d60dfbe4 AM |
225 | enableCmd.populate(data); |
226 | enableCmd.execute(logAgent); | |
227 | data = enableCmd.getBytes(); | |
228 | break; | |
229 | } | |
230 | case CMD_DISABLE: | |
231 | { | |
232 | SessiondDisableHandler disableCmd = new SessiondDisableHandler(); | |
233 | if (data == null) { | |
234 | disableCmd.setRetCode(ISessiondResponse.LttngAgentRetCode.CODE_INVALID_CMD); | |
43e5396b DG |
235 | break; |
236 | } | |
d60dfbe4 AM |
237 | disableCmd.populate(data); |
238 | disableCmd.execute(logAgent); | |
239 | data = disableCmd.getBytes(); | |
240 | break; | |
241 | } | |
242 | default: | |
243 | { | |
244 | data = new byte[4]; | |
245 | ByteBuffer buf = ByteBuffer.wrap(data); | |
246 | buf.order(ByteOrder.BIG_ENDIAN); | |
247 | break; | |
248 | } | |
43e5396b DG |
249 | } |
250 | ||
d60dfbe4 AM |
251 | if (data == null) { |
252 | /* | |
253 | * Simply used to silence a potential null access warning below. | |
254 | * | |
255 | * The flow analysis gets confused here and thinks "data" may be | |
256 | * null at this point. It should not happen according to program | |
257 | * logic, if it does we've done something wrong. | |
258 | */ | |
259 | throw new IllegalStateException(); | |
260 | } | |
43e5396b DG |
261 | /* Send payload to session daemon. */ |
262 | this.outToSessiond.write(data, 0, data.length); | |
263 | this.outToSessiond.flush(); | |
264 | } | |
265 | } | |
266 | ||
bc7de6d9 | 267 | private static String getHomePath() { |
f1fa0535 DG |
268 | return System.getProperty("user.home"); |
269 | } | |
270 | ||
271 | /** | |
272 | * Read port number from file created by the session daemon. | |
273 | * | |
274 | * @return port value if found else 0. | |
275 | */ | |
bc7de6d9 | 276 | private static int getPortFromFile(String path) throws IOException { |
f1fa0535 | 277 | int port; |
d60dfbe4 | 278 | BufferedReader br = null; |
f1fa0535 DG |
279 | |
280 | try { | |
281 | br = new BufferedReader(new FileReader(path)); | |
282 | String line = br.readLine(); | |
283 | port = Integer.parseInt(line, 10); | |
284 | if (port < 0 || port > 65535) { | |
285 | /* Invalid value. Ignore. */ | |
286 | port = 0; | |
287 | } | |
f1fa0535 DG |
288 | } catch (FileNotFoundException e) { |
289 | /* No port available. */ | |
290 | port = 0; | |
d60dfbe4 AM |
291 | } finally { |
292 | if (br != null) { | |
293 | br.close(); | |
294 | } | |
f1fa0535 DG |
295 | } |
296 | ||
297 | return port; | |
298 | } | |
299 | ||
d60dfbe4 | 300 | private void connectToSessiond() throws IOException { |
f1fa0535 DG |
301 | int port; |
302 | ||
d60dfbe4 | 303 | if (this.isRoot) { |
08284556 | 304 | port = getPortFromFile(ROOT_PORT_FILE); |
f1fa0535 DG |
305 | if (port == 0) { |
306 | /* No session daemon available. Stop and retry later. */ | |
307 | throw new IOException(); | |
308 | } | |
309 | } else { | |
08284556 | 310 | port = getPortFromFile(getHomePath() + USER_PORT_FILE); |
f1fa0535 DG |
311 | if (port == 0) { |
312 | /* No session daemon available. Stop and retry later. */ | |
313 | throw new IOException(); | |
314 | } | |
315 | } | |
316 | ||
08284556 AM |
317 | this.sessiondSock = new Socket(SESSION_HOST, port); |
318 | this.inFromSessiond = new DataInputStream(sessiondSock.getInputStream()); | |
319 | this.outToSessiond = new DataOutputStream(sessiondSock.getOutputStream()); | |
43e5396b DG |
320 | } |
321 | ||
d60dfbe4 | 322 | private void registerToSessiond() throws IOException { |
501f6777 | 323 | byte data[] = new byte[16]; |
43e5396b DG |
324 | ByteBuffer buf = ByteBuffer.wrap(data); |
325 | String pid = ManagementFactory.getRuntimeMXBean().getName().split("@")[0]; | |
326 | ||
d60dfbe4 | 327 | buf.putInt(logAgent.getDomain().value()); |
43e5396b | 328 | buf.putInt(Integer.parseInt(pid)); |
bc7de6d9 AM |
329 | buf.putInt(protocolMajorVersion); |
330 | buf.putInt(protocolMinorVersion); | |
43e5396b DG |
331 | this.outToSessiond.write(data, 0, data.length); |
332 | this.outToSessiond.flush(); | |
333 | } | |
334 | } |