Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 1 | /* |
Volker Simonis | 40728fc | 2015-03-18 09:13:11 +0100 | [diff] [blame] | 2 | * Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved. |
Goetz Lindenmaier | 3268787 | 2016-01-27 10:35:49 +0100 | [diff] [blame] | 3 | * Copyright (c) 2015 SAP SE. All rights reserved. |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 4 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 5 | * |
| 6 | * This code is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License version 2 only, as |
| 8 | * published by the Free Software Foundation. Oracle designates this |
| 9 | * particular file as subject to the "Classpath" exception as provided |
| 10 | * by Oracle in the LICENSE file that accompanied this code. |
| 11 | * |
| 12 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 13 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 14 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 15 | * version 2 for more details (a copy is included in the LICENSE file that |
| 16 | * accompanied this code). |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License version |
| 19 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 20 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 21 | * |
| 22 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| 23 | * or visit www.oracle.com if you need additional information or have any |
| 24 | * questions. |
| 25 | */ |
| 26 | package sun.tools.attach; |
| 27 | |
Volker Simonis | 40728fc | 2015-03-18 09:13:11 +0100 | [diff] [blame] | 28 | import com.sun.tools.attach.AttachOperationFailedException; |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 29 | import com.sun.tools.attach.AgentLoadException; |
| 30 | import com.sun.tools.attach.AttachNotSupportedException; |
| 31 | import com.sun.tools.attach.spi.AttachProvider; |
Volker Simonis | 40728fc | 2015-03-18 09:13:11 +0100 | [diff] [blame] | 32 | |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 33 | import java.io.InputStream; |
| 34 | import java.io.IOException; |
| 35 | import java.io.File; |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 36 | |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 37 | // Based on linux/classes/sun/tools/attach/VirtualMachineImpl.java. |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 38 | |
| 39 | /* |
| 40 | * Aix implementation of HotSpotVirtualMachine |
| 41 | */ |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 42 | public class VirtualMachineImpl extends HotSpotVirtualMachine { |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 43 | // "/tmp" is used as a global well-known location for the files |
| 44 | // .java_pid<pid>. and .attach_pid<pid>. It is important that this |
| 45 | // location is the same for all processes, otherwise the tools |
| 46 | // will not be able to find all Hotspot processes. |
| 47 | // Any changes to this needs to be synchronized with HotSpot. |
| 48 | private static final String tmpdir = "/tmp"; |
| 49 | |
| 50 | // The patch to the socket file created by the target VM |
| 51 | String path; |
| 52 | |
| 53 | /** |
| 54 | * Attaches to the target VM |
| 55 | */ |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 56 | VirtualMachineImpl(AttachProvider provider, String vmid) |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 57 | throws AttachNotSupportedException, IOException |
| 58 | { |
| 59 | super(provider, vmid); |
| 60 | |
| 61 | // This provider only understands pids |
| 62 | int pid; |
| 63 | try { |
| 64 | pid = Integer.parseInt(vmid); |
| 65 | } catch (NumberFormatException x) { |
| 66 | throw new AttachNotSupportedException("Invalid process identifier"); |
| 67 | } |
| 68 | |
| 69 | // Find the socket file. If not found then we attempt to start the |
| 70 | // attach mechanism in the target VM by sending it a QUIT signal. |
| 71 | // Then we attempt to find the socket file again. |
| 72 | path = findSocketFile(pid); |
| 73 | if (path == null) { |
| 74 | File f = createAttachFile(pid); |
| 75 | try { |
| 76 | sendQuitTo(pid); |
| 77 | |
| 78 | // give the target VM time to start the attach mechanism |
Dmitry Samersoff | b022343 | 2016-08-18 13:19:38 +0300 | [diff] [blame] | 79 | final int delay_step = 100; |
| 80 | final long timeout = attachTimeout(); |
| 81 | long time_spend = 0; |
| 82 | long delay = 0; |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 83 | do { |
Dmitry Samersoff | b022343 | 2016-08-18 13:19:38 +0300 | [diff] [blame] | 84 | // Increase timeout on each attempt to reduce polling |
| 85 | delay += delay_step; |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 86 | try { |
| 87 | Thread.sleep(delay); |
| 88 | } catch (InterruptedException x) { } |
| 89 | path = findSocketFile(pid); |
Dmitry Samersoff | b022343 | 2016-08-18 13:19:38 +0300 | [diff] [blame] | 90 | |
| 91 | time_spend += delay; |
| 92 | if (time_spend > timeout/2 && path == null) { |
| 93 | // Send QUIT again to give target VM the last chance to react |
| 94 | sendQuitTo(pid); |
| 95 | } |
| 96 | } while (time_spend <= timeout && path == null); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 97 | if (path == null) { |
| 98 | throw new AttachNotSupportedException( |
Dmitry Samersoff | b022343 | 2016-08-18 13:19:38 +0300 | [diff] [blame] | 99 | String.format("Unable to open socket file %s: " + |
| 100 | "target process %d doesn't respond within %dms " + |
| 101 | "or HotSpot VM not loaded", f.getPath(), pid, time_spend)); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 102 | } |
| 103 | } finally { |
| 104 | f.delete(); |
| 105 | } |
| 106 | } |
| 107 | |
| 108 | // Check that the file owner/permission to avoid attaching to |
| 109 | // bogus process |
| 110 | checkPermissions(path); |
| 111 | |
| 112 | // Check that we can connect to the process |
| 113 | // - this ensures we throw the permission denied error now rather than |
| 114 | // later when we attempt to enqueue a command. |
| 115 | int s = socket(); |
| 116 | try { |
| 117 | connect(s, path); |
| 118 | } finally { |
| 119 | close(s); |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | /** |
| 124 | * Detach from the target VM |
| 125 | */ |
| 126 | public void detach() throws IOException { |
| 127 | synchronized (this) { |
| 128 | if (this.path != null) { |
| 129 | this.path = null; |
| 130 | } |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | // protocol version |
| 135 | private final static String PROTOCOL_VERSION = "1"; |
| 136 | |
| 137 | // known errors |
| 138 | private final static int ATTACH_ERROR_BADVERSION = 101; |
| 139 | |
| 140 | /** |
| 141 | * Execute the given command in the target VM. |
| 142 | */ |
| 143 | InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException { |
| 144 | assert args.length <= 3; // includes null |
| 145 | |
| 146 | // did we detach? |
| 147 | String p; |
| 148 | synchronized (this) { |
| 149 | if (this.path == null) { |
| 150 | throw new IOException("Detached from target VM"); |
| 151 | } |
| 152 | p = this.path; |
| 153 | } |
| 154 | |
| 155 | // create UNIX socket |
| 156 | int s = socket(); |
| 157 | |
| 158 | // connect to target VM |
| 159 | try { |
| 160 | connect(s, p); |
| 161 | } catch (IOException x) { |
| 162 | close(s); |
| 163 | throw x; |
| 164 | } |
| 165 | |
| 166 | IOException ioe = null; |
| 167 | |
| 168 | // connected - write request |
| 169 | // <ver> <cmd> <args...> |
| 170 | try { |
| 171 | writeString(s, PROTOCOL_VERSION); |
| 172 | writeString(s, cmd); |
| 173 | |
| 174 | for (int i=0; i<3; i++) { |
| 175 | if (i < args.length && args[i] != null) { |
| 176 | writeString(s, (String)args[i]); |
| 177 | } else { |
| 178 | writeString(s, ""); |
| 179 | } |
| 180 | } |
| 181 | } catch (IOException x) { |
| 182 | ioe = x; |
| 183 | } |
| 184 | |
| 185 | |
| 186 | // Create an input stream to read reply |
| 187 | SocketInputStream sis = new SocketInputStream(s); |
| 188 | |
| 189 | // Read the command completion status |
| 190 | int completionStatus; |
| 191 | try { |
| 192 | completionStatus = readInt(sis); |
| 193 | } catch (IOException x) { |
| 194 | sis.close(); |
| 195 | if (ioe != null) { |
| 196 | throw ioe; |
| 197 | } else { |
| 198 | throw x; |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | if (completionStatus != 0) { |
Volker Simonis | 40728fc | 2015-03-18 09:13:11 +0100 | [diff] [blame] | 203 | // read from the stream and use that as the error message |
| 204 | String message = readErrorMessage(sis); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 205 | sis.close(); |
| 206 | |
| 207 | // In the event of a protocol mismatch then the target VM |
| 208 | // returns a known error so that we can throw a reasonable |
| 209 | // error. |
| 210 | if (completionStatus == ATTACH_ERROR_BADVERSION) { |
| 211 | throw new IOException("Protocol mismatch with target VM"); |
| 212 | } |
| 213 | |
| 214 | // Special-case the "load" command so that the right exception is |
| 215 | // thrown. |
| 216 | if (cmd.equals("load")) { |
Alan Bateman | 4c0e26e | 2017-05-04 07:26:55 +0000 | [diff] [blame] | 217 | String msg = "Failed to load agent library"; |
| 218 | if (!message.isEmpty()) |
| 219 | msg += ": " + message; |
| 220 | throw new AgentLoadException(msg); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 221 | } else { |
Alan Bateman | 4c0e26e | 2017-05-04 07:26:55 +0000 | [diff] [blame] | 222 | if (message.isEmpty()) |
| 223 | message = "Command failed in target VM"; |
| 224 | throw new AttachOperationFailedException(message); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 225 | } |
| 226 | } |
| 227 | |
| 228 | // Return the input stream so that the command output can be read |
| 229 | return sis; |
| 230 | } |
| 231 | |
| 232 | /* |
| 233 | * InputStream for the socket connection to get target VM |
| 234 | */ |
| 235 | private class SocketInputStream extends InputStream { |
| 236 | int s; |
| 237 | |
| 238 | public SocketInputStream(int s) { |
| 239 | this.s = s; |
| 240 | } |
| 241 | |
| 242 | public synchronized int read() throws IOException { |
| 243 | byte b[] = new byte[1]; |
| 244 | int n = this.read(b, 0, 1); |
| 245 | if (n == 1) { |
| 246 | return b[0] & 0xff; |
| 247 | } else { |
| 248 | return -1; |
| 249 | } |
| 250 | } |
| 251 | |
| 252 | public synchronized int read(byte[] bs, int off, int len) throws IOException { |
| 253 | if ((off < 0) || (off > bs.length) || (len < 0) || |
| 254 | ((off + len) > bs.length) || ((off + len) < 0)) { |
| 255 | throw new IndexOutOfBoundsException(); |
| 256 | } else if (len == 0) |
| 257 | return 0; |
| 258 | |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 259 | return VirtualMachineImpl.read(s, bs, off, len); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | public void close() throws IOException { |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 263 | VirtualMachineImpl.close(s); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 264 | } |
| 265 | } |
| 266 | |
| 267 | // Return the socket file for the given process. |
| 268 | private String findSocketFile(int pid) { |
| 269 | File f = new File(tmpdir, ".java_pid" + pid); |
| 270 | if (!f.exists()) { |
| 271 | return null; |
| 272 | } |
| 273 | return f.getPath(); |
| 274 | } |
| 275 | |
| 276 | // On Solaris/Linux/Aix a simple handshake is used to start the attach mechanism |
| 277 | // if not already started. The client creates a .attach_pid<pid> file in the |
| 278 | // target VM's working directory (or temp directory), and the SIGQUIT handler |
| 279 | // checks for the file. |
| 280 | private File createAttachFile(int pid) throws IOException { |
| 281 | String fn = ".attach_pid" + pid; |
| 282 | String path = "/proc/" + pid + "/cwd/" + fn; |
| 283 | File f = new File(path); |
| 284 | try { |
| 285 | f.createNewFile(); |
| 286 | } catch (IOException x) { |
| 287 | f = new File(tmpdir, fn); |
| 288 | f.createNewFile(); |
| 289 | } |
| 290 | return f; |
| 291 | } |
| 292 | |
| 293 | /* |
| 294 | * Write/sends the given to the target VM. String is transmitted in |
| 295 | * UTF-8 encoding. |
| 296 | */ |
| 297 | private void writeString(int fd, String s) throws IOException { |
| 298 | if (s.length() > 0) { |
| 299 | byte b[]; |
| 300 | try { |
| 301 | b = s.getBytes("UTF-8"); |
| 302 | } catch (java.io.UnsupportedEncodingException x) { |
| 303 | throw new InternalError(x); |
| 304 | } |
Mandy Chung | 6533d2d | 2014-08-26 14:35:33 -0700 | [diff] [blame] | 305 | VirtualMachineImpl.write(fd, b, 0, b.length); |
Jonathan Lu | 780a134 | 2013-11-26 16:40:31 +0100 | [diff] [blame] | 306 | } |
| 307 | byte b[] = new byte[1]; |
| 308 | b[0] = 0; |
| 309 | write(fd, b, 0, 1); |
| 310 | } |
| 311 | |
| 312 | |
| 313 | //-- native methods |
| 314 | |
| 315 | static native void sendQuitTo(int pid) throws IOException; |
| 316 | |
| 317 | static native void checkPermissions(String path) throws IOException; |
| 318 | |
| 319 | static native int socket() throws IOException; |
| 320 | |
| 321 | static native void connect(int fd, String path) throws IOException; |
| 322 | |
| 323 | static native void close(int fd) throws IOException; |
| 324 | |
| 325 | static native int read(int fd, byte buf[], int off, int bufLen) throws IOException; |
| 326 | |
| 327 | static native void write(int fd, byte buf[], int off, int bufLen) throws IOException; |
| 328 | |
| 329 | static { |
| 330 | System.loadLibrary("attach"); |
| 331 | } |
| 332 | } |