| /* |
| * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package sun.tools.attach; |
| |
| import com.sun.tools.attach.AttachOperationFailedException; |
| import com.sun.tools.attach.AgentLoadException; |
| import com.sun.tools.attach.AttachNotSupportedException; |
| import com.sun.tools.attach.spi.AttachProvider; |
| |
| import java.io.InputStream; |
| import java.io.IOException; |
| import java.io.File; |
| |
| /* |
| * Bsd implementation of HotSpotVirtualMachine |
| */ |
| public class VirtualMachineImpl extends HotSpotVirtualMachine { |
| // "tmpdir" is used as a global well-known location for the files |
| // .java_pid<pid>. and .attach_pid<pid>. It is important that this |
| // location is the same for all processes, otherwise the tools |
| // will not be able to find all Hotspot processes. |
| // This is intentionally not the same as java.io.tmpdir, since |
| // the latter can be changed by the user. |
| // Any changes to this needs to be synchronized with HotSpot. |
| private static final String tmpdir; |
| |
| // The patch to the socket file created by the target VM |
| String path; |
| |
| /** |
| * Attaches to the target VM |
| */ |
| VirtualMachineImpl(AttachProvider provider, String vmid) |
| throws AttachNotSupportedException, IOException |
| { |
| super(provider, vmid); |
| |
| // This provider only understands pids |
| int pid; |
| try { |
| pid = Integer.parseInt(vmid); |
| } catch (NumberFormatException x) { |
| throw new AttachNotSupportedException("Invalid process identifier"); |
| } |
| |
| // Find the socket file. If not found then we attempt to start the |
| // attach mechanism in the target VM by sending it a QUIT signal. |
| // Then we attempt to find the socket file again. |
| path = findSocketFile(pid); |
| if (path == null) { |
| File f = createAttachFile(pid); |
| try { |
| sendQuitTo(pid); |
| |
| // give the target VM time to start the attach mechanism |
| final int delay_step = 100; |
| final long timeout = attachTimeout(); |
| long time_spend = 0; |
| long delay = 0; |
| do { |
| // Increase timeout on each attempt to reduce polling |
| delay += delay_step; |
| try { |
| Thread.sleep(delay); |
| } catch (InterruptedException x) { } |
| path = findSocketFile(pid); |
| |
| time_spend += delay; |
| if (time_spend > timeout/2 && path == null) { |
| // Send QUIT again to give target VM the last chance to react |
| sendQuitTo(pid); |
| } |
| } while (time_spend <= timeout && path == null); |
| if (path == null) { |
| throw new AttachNotSupportedException( |
| String.format("Unable to open socket file %s: " + |
| "target process %d doesn't respond within %dms " + |
| "or HotSpot VM not loaded", f.getPath(), pid, time_spend)); |
| } |
| } finally { |
| f.delete(); |
| } |
| } |
| |
| // Check that the file owner/permission to avoid attaching to |
| // bogus process |
| checkPermissions(path); |
| |
| // Check that we can connect to the process |
| // - this ensures we throw the permission denied error now rather than |
| // later when we attempt to enqueue a command. |
| int s = socket(); |
| try { |
| connect(s, path); |
| } finally { |
| close(s); |
| } |
| } |
| |
| /** |
| * Detach from the target VM |
| */ |
| public void detach() throws IOException { |
| synchronized (this) { |
| if (this.path != null) { |
| this.path = null; |
| } |
| } |
| } |
| |
| // protocol version |
| private final static String PROTOCOL_VERSION = "1"; |
| |
| // known errors |
| private final static int ATTACH_ERROR_BADVERSION = 101; |
| |
| /** |
| * Execute the given command in the target VM. |
| */ |
| InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOException { |
| assert args.length <= 3; // includes null |
| |
| // did we detach? |
| String p; |
| synchronized (this) { |
| if (this.path == null) { |
| throw new IOException("Detached from target VM"); |
| } |
| p = this.path; |
| } |
| |
| // create UNIX socket |
| int s = socket(); |
| |
| // connect to target VM |
| try { |
| connect(s, p); |
| } catch (IOException x) { |
| close(s); |
| throw x; |
| } |
| |
| IOException ioe = null; |
| |
| // connected - write request |
| // <ver> <cmd> <args...> |
| try { |
| writeString(s, PROTOCOL_VERSION); |
| writeString(s, cmd); |
| |
| for (int i=0; i<3; i++) { |
| if (i < args.length && args[i] != null) { |
| writeString(s, (String)args[i]); |
| } else { |
| writeString(s, ""); |
| } |
| } |
| } catch (IOException x) { |
| ioe = x; |
| } |
| |
| |
| // Create an input stream to read reply |
| SocketInputStream sis = new SocketInputStream(s); |
| |
| // Read the command completion status |
| int completionStatus; |
| try { |
| completionStatus = readInt(sis); |
| } catch (IOException x) { |
| sis.close(); |
| if (ioe != null) { |
| throw ioe; |
| } else { |
| throw x; |
| } |
| } |
| |
| if (completionStatus != 0) { |
| // read from the stream and use that as the error message |
| String message = readErrorMessage(sis); |
| sis.close(); |
| |
| // In the event of a protocol mismatch then the target VM |
| // returns a known error so that we can throw a reasonable |
| // error. |
| if (completionStatus == ATTACH_ERROR_BADVERSION) { |
| throw new IOException("Protocol mismatch with target VM"); |
| } |
| |
| // Special-case the "load" command so that the right exception is |
| // thrown. |
| if (cmd.equals("load")) { |
| String msg = "Failed to load agent library"; |
| if (!message.isEmpty()) |
| msg += ": " + message; |
| throw new AgentLoadException(msg); |
| } else { |
| if (message.isEmpty()) |
| message = "Command failed in target VM"; |
| throw new AttachOperationFailedException(message); |
| } |
| } |
| |
| // Return the input stream so that the command output can be read |
| return sis; |
| } |
| |
| /* |
| * InputStream for the socket connection to get target VM |
| */ |
| private class SocketInputStream extends InputStream { |
| int s; |
| |
| public SocketInputStream(int s) { |
| this.s = s; |
| } |
| |
| public synchronized int read() throws IOException { |
| byte b[] = new byte[1]; |
| int n = this.read(b, 0, 1); |
| if (n == 1) { |
| return b[0] & 0xff; |
| } else { |
| return -1; |
| } |
| } |
| |
| public synchronized int read(byte[] bs, int off, int len) throws IOException { |
| if ((off < 0) || (off > bs.length) || (len < 0) || |
| ((off + len) > bs.length) || ((off + len) < 0)) { |
| throw new IndexOutOfBoundsException(); |
| } else if (len == 0) { |
| return 0; |
| } |
| |
| return VirtualMachineImpl.read(s, bs, off, len); |
| } |
| |
| public void close() throws IOException { |
| VirtualMachineImpl.close(s); |
| } |
| } |
| |
| // Return the socket file for the given process. |
| // Checks temp directory for .java_pid<pid>. |
| private String findSocketFile(int pid) { |
| String fn = ".java_pid" + pid; |
| File f = new File(tmpdir, fn); |
| return f.exists() ? f.getPath() : null; |
| } |
| |
| /* |
| * Write/sends the given to the target VM. String is transmitted in |
| * UTF-8 encoding. |
| */ |
| private void writeString(int fd, String s) throws IOException { |
| if (s.length() > 0) { |
| byte b[]; |
| try { |
| b = s.getBytes("UTF-8"); |
| } catch (java.io.UnsupportedEncodingException x) { |
| throw new InternalError(); |
| } |
| VirtualMachineImpl.write(fd, b, 0, b.length); |
| } |
| byte b[] = new byte[1]; |
| b[0] = 0; |
| write(fd, b, 0, 1); |
| } |
| |
| private File createAttachFile(int pid) throws IOException { |
| String fn = ".attach_pid" + pid; |
| File f = new File(tmpdir, fn); |
| createAttachFile0(f.getPath()); |
| return f; |
| } |
| |
| //-- native methods |
| |
| static native void sendQuitTo(int pid) throws IOException; |
| |
| static native void checkPermissions(String path) throws IOException; |
| |
| static native int socket() throws IOException; |
| |
| static native void connect(int fd, String path) throws IOException; |
| |
| static native void close(int fd) throws IOException; |
| |
| static native int read(int fd, byte buf[], int off, int bufLen) throws IOException; |
| |
| static native void write(int fd, byte buf[], int off, int bufLen) throws IOException; |
| |
| static native void createAttachFile0(String path); |
| |
| static native String getTempDir(); |
| |
| static { |
| System.loadLibrary("attach"); |
| tmpdir = getTempDir(); |
| } |
| } |