| 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 | |
| 18 | package org.lttng.ust.agent; |
| 19 | |
| 20 | import java.io.BufferedReader; |
| 21 | import java.io.DataInputStream; |
| 22 | import java.io.DataOutputStream; |
| 23 | import java.io.FileNotFoundException; |
| 24 | import java.io.FileReader; |
| 25 | import java.io.IOException; |
| 26 | import java.lang.management.ManagementFactory; |
| 27 | import java.net.Socket; |
| 28 | import java.net.UnknownHostException; |
| 29 | import java.nio.ByteBuffer; |
| 30 | import java.nio.ByteOrder; |
| 31 | import java.util.concurrent.Semaphore; |
| 32 | |
| 33 | class LTTngTCPSessiondClient implements Runnable { |
| 34 | |
| 35 | /* Command header from the session deamon. */ |
| 36 | private LTTngSessiondCmd2_6.sessiond_hdr headerCmd = |
| 37 | new LTTngSessiondCmd2_6.sessiond_hdr(); |
| 38 | |
| 39 | private Socket sessiondSock; |
| 40 | private volatile boolean quit = false; |
| 41 | |
| 42 | private DataInputStream inFromSessiond; |
| 43 | private DataOutputStream outToSessiond; |
| 44 | |
| 45 | private LogFramework log; |
| 46 | |
| 47 | private Semaphore registerSem; |
| 48 | |
| 49 | private static final String sessiondHost = "127.0.0.1"; |
| 50 | private static final String rootPortFile = "/var/run/lttng/agent.port"; |
| 51 | private static final String userPortFile = "/.lttng/agent.port"; |
| 52 | |
| 53 | private static Integer protocolMajorVersion = 1; |
| 54 | private static Integer protocolMinorVersion = 0; |
| 55 | |
| 56 | private LTTngAgent.Domain agentDomain; |
| 57 | |
| 58 | /* Indicate if we've already release the semaphore. */ |
| 59 | private boolean sem_posted = false; |
| 60 | |
| 61 | public LTTngTCPSessiondClient(LTTngAgent.Domain domain, LogFramework log, Semaphore sem) { |
| 62 | this.agentDomain = domain; |
| 63 | this.log = log; |
| 64 | this.registerSem = sem; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * Try to release the registerSem if it's not already done. |
| 69 | */ |
| 70 | private void tryReleaseSem() |
| 71 | { |
| 72 | /* Release semaphore so we unblock the agent. */ |
| 73 | if (!this.sem_posted) { |
| 74 | this.registerSem.release(); |
| 75 | this.sem_posted = true; |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | @Override |
| 80 | public void run() { |
| 81 | for (;;) { |
| 82 | if (this.quit) { |
| 83 | break; |
| 84 | } |
| 85 | |
| 86 | /* Cleanup Agent state before trying to connect or reconnect. */ |
| 87 | this.log.reset(); |
| 88 | |
| 89 | try { |
| 90 | |
| 91 | /* |
| 92 | * Connect to the session daemon before anything else. |
| 93 | */ |
| 94 | connectToSessiond(); |
| 95 | |
| 96 | /* |
| 97 | * Register to the session daemon as the Java component of the |
| 98 | * UST application. |
| 99 | */ |
| 100 | registerToSessiond(); |
| 101 | |
| 102 | /* |
| 103 | * Block on socket receive and wait for command from the |
| 104 | * session daemon. This will return if and only if there is a |
| 105 | * fatal error or the socket closes. |
| 106 | */ |
| 107 | handleSessiondCmd(); |
| 108 | } catch (UnknownHostException uhe) { |
| 109 | tryReleaseSem(); |
| 110 | System.out.println(uhe); |
| 111 | } catch (IOException ioe) { |
| 112 | tryReleaseSem(); |
| 113 | try { |
| 114 | Thread.sleep(3000); |
| 115 | } catch (InterruptedException e) { |
| 116 | e.printStackTrace(); |
| 117 | } |
| 118 | } catch (Exception e) { |
| 119 | tryReleaseSem(); |
| 120 | e.printStackTrace(); |
| 121 | } |
| 122 | } |
| 123 | } |
| 124 | |
| 125 | public void destroy() { |
| 126 | this.quit = true; |
| 127 | |
| 128 | try { |
| 129 | if (this.sessiondSock != null) { |
| 130 | this.sessiondSock.close(); |
| 131 | } |
| 132 | } catch (Exception e) { |
| 133 | e.printStackTrace(); |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Receive header data from the session daemon using the LTTng command |
| 139 | * static buffer of the right size. |
| 140 | */ |
| 141 | private void recvHeader() throws Exception { |
| 142 | int read_len; |
| 143 | byte data[] = new byte[LTTngSessiondCmd2_6.sessiond_hdr.SIZE]; |
| 144 | |
| 145 | read_len = this.inFromSessiond.read(data, 0, data.length); |
| 146 | if (read_len != data.length) { |
| 147 | throw new IOException(); |
| 148 | } |
| 149 | this.headerCmd.populate(data); |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * Receive payload from the session daemon. This MUST be done after a |
| 154 | * recvHeader() so the header value of a command are known. |
| 155 | * |
| 156 | * The caller SHOULD use isPayload() before which returns true if a payload |
| 157 | * is expected after the header. |
| 158 | */ |
| 159 | private byte[] recvPayload() throws Exception { |
| 160 | byte payload[] = new byte[(int) this.headerCmd.data_size]; |
| 161 | |
| 162 | /* Failsafe check so we don't waste our time reading 0 bytes. */ |
| 163 | if (payload.length == 0) { |
| 164 | return null; |
| 165 | } |
| 166 | |
| 167 | this.inFromSessiond.read(payload, 0, payload.length); |
| 168 | return payload; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * Handle session command from the session daemon. |
| 173 | */ |
| 174 | private void handleSessiondCmd() throws Exception { |
| 175 | byte data[] = null; |
| 176 | |
| 177 | while (true) { |
| 178 | /* Get header from session daemon. */ |
| 179 | recvHeader(); |
| 180 | |
| 181 | if (headerCmd.data_size > 0) { |
| 182 | data = recvPayload(); |
| 183 | } |
| 184 | |
| 185 | switch (headerCmd.cmd) { |
| 186 | case CMD_REG_DONE: |
| 187 | { |
| 188 | /* |
| 189 | * Release semaphore so meaning registration is done and we |
| 190 | * can proceed to continue tracing. |
| 191 | */ |
| 192 | tryReleaseSem(); |
| 193 | /* |
| 194 | * We don't send any reply to the registration done command. |
| 195 | * This just marks the end of the initial session setup. |
| 196 | */ |
| 197 | continue; |
| 198 | } |
| 199 | case CMD_LIST: |
| 200 | { |
| 201 | LTTngSessiondCmd2_6.sessiond_list_logger listLoggerCmd = |
| 202 | new LTTngSessiondCmd2_6.sessiond_list_logger(); |
| 203 | listLoggerCmd.execute(this.log); |
| 204 | data = listLoggerCmd.getBytes(); |
| 205 | break; |
| 206 | } |
| 207 | case CMD_ENABLE: |
| 208 | { |
| 209 | LTTngSessiondCmd2_6.sessiond_enable_handler enableCmd = |
| 210 | new LTTngSessiondCmd2_6.sessiond_enable_handler(); |
| 211 | if (data == null) { |
| 212 | enableCmd.code = LTTngSessiondCmd2_6.lttng_agent_ret_code.CODE_INVALID_CMD; |
| 213 | break; |
| 214 | } |
| 215 | enableCmd.populate(data); |
| 216 | enableCmd.execute(this.log); |
| 217 | data = enableCmd.getBytes(); |
| 218 | break; |
| 219 | } |
| 220 | case CMD_DISABLE: |
| 221 | { |
| 222 | LTTngSessiondCmd2_6.sessiond_disable_handler disableCmd = |
| 223 | new LTTngSessiondCmd2_6.sessiond_disable_handler(); |
| 224 | if (data == null) { |
| 225 | disableCmd.code = LTTngSessiondCmd2_6.lttng_agent_ret_code.CODE_INVALID_CMD; |
| 226 | break; |
| 227 | } |
| 228 | disableCmd.populate(data); |
| 229 | disableCmd.execute(this.log); |
| 230 | data = disableCmd.getBytes(); |
| 231 | break; |
| 232 | } |
| 233 | default: |
| 234 | { |
| 235 | data = new byte[4]; |
| 236 | ByteBuffer buf = ByteBuffer.wrap(data); |
| 237 | buf.order(ByteOrder.BIG_ENDIAN); |
| 238 | break; |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | /* Send payload to session daemon. */ |
| 243 | this.outToSessiond.write(data, 0, data.length); |
| 244 | this.outToSessiond.flush(); |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | private static String getHomePath() { |
| 249 | return System.getProperty("user.home"); |
| 250 | } |
| 251 | |
| 252 | /** |
| 253 | * Read port number from file created by the session daemon. |
| 254 | * |
| 255 | * @return port value if found else 0. |
| 256 | */ |
| 257 | private static int getPortFromFile(String path) throws IOException { |
| 258 | int port; |
| 259 | BufferedReader br; |
| 260 | |
| 261 | try { |
| 262 | br = new BufferedReader(new FileReader(path)); |
| 263 | String line = br.readLine(); |
| 264 | port = Integer.parseInt(line, 10); |
| 265 | if (port < 0 || port > 65535) { |
| 266 | /* Invalid value. Ignore. */ |
| 267 | port = 0; |
| 268 | } |
| 269 | br.close(); |
| 270 | } catch (FileNotFoundException e) { |
| 271 | /* No port available. */ |
| 272 | port = 0; |
| 273 | } |
| 274 | |
| 275 | return port; |
| 276 | } |
| 277 | |
| 278 | private void connectToSessiond() throws Exception { |
| 279 | int port; |
| 280 | |
| 281 | if (this.log.isRoot()) { |
| 282 | port = getPortFromFile(rootPortFile); |
| 283 | if (port == 0) { |
| 284 | /* No session daemon available. Stop and retry later. */ |
| 285 | throw new IOException(); |
| 286 | } |
| 287 | } else { |
| 288 | port = getPortFromFile(getHomePath() + userPortFile); |
| 289 | if (port == 0) { |
| 290 | /* No session daemon available. Stop and retry later. */ |
| 291 | throw new IOException(); |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | this.sessiondSock = new Socket(sessiondHost, port); |
| 296 | this.inFromSessiond = new DataInputStream( |
| 297 | sessiondSock.getInputStream()); |
| 298 | this.outToSessiond = new DataOutputStream( |
| 299 | sessiondSock.getOutputStream()); |
| 300 | } |
| 301 | |
| 302 | private void registerToSessiond() throws Exception { |
| 303 | byte data[] = new byte[16]; |
| 304 | ByteBuffer buf = ByteBuffer.wrap(data); |
| 305 | String pid = ManagementFactory.getRuntimeMXBean().getName().split("@")[0]; |
| 306 | |
| 307 | buf.putInt(this.agentDomain.value()); |
| 308 | buf.putInt(Integer.parseInt(pid)); |
| 309 | buf.putInt(protocolMajorVersion); |
| 310 | buf.putInt(protocolMinorVersion); |
| 311 | this.outToSessiond.write(data, 0, data.length); |
| 312 | this.outToSessiond.flush(); |
| 313 | } |
| 314 | } |