The R13B03 release.OTP_R13B03

1 files changed, 569 insertions, 0 deletions

diff --git a/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpEpmd.java b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpEpmd.java
new file mode 100644
index 0000000000..3bb678c2cc
--- /dev/null
+++ b/lib/jinterface/java_src/com/ericsson/otp/erlang/OtpEpmd.java
@@ -0,0 +1,569 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 2000-2009. All Rights Reserved.
+ * 
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ * 
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * %CopyrightEnd%
+ */
+package com.ericsson.otp.erlang;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.Socket;
+
+/**
+ * Provides methods for registering, unregistering and looking up nodes with the
+ * Erlang portmapper daemon (Epmd). For each registered node, Epmd maintains
+ * information about the port on which incoming connections are accepted, as
+ * well as which versions of the Erlang communication protocolt the node
+ * supports.
+ * 
+ * <p>
+ * Nodes wishing to contact other nodes must first request information from Epmd
+ * before a connection can be set up, however this is done automatically by
+ * {@link OtpSelf#connect(OtpPeer) OtpSelf.connect()} when necessary.
+ * 
+ * <p>
+ * The methods {@link #publishPort(OtpLocalNode) publishPort()} and
+ * {@link #unPublishPort(OtpLocalNode) unPublishPort()} will fail if an Epmd
+ * process is not running on the localhost. Additionally
+ * {@link #lookupPort(AbstractNode) lookupPort()} will fail if there is no Epmd
+ * process running on the host where the specified node is running. See the
+ * Erlang documentation for information about starting Epmd.
+ * 
+ * <p>
+ * This class contains only static methods, there are no constructors.
+ */
+public class OtpEpmd {
+
+    private static class EpmdPort {
+	private static int epmdPort = 0;
+	
+	public static int get() {
+	    if (epmdPort == 0) {
+		String env;
+		try {
+		    env = System.getenv("ERL_EPMD_PORT");
+		} 
+		catch (java.lang.SecurityException e) {
+		    env = null;
+		}
+		epmdPort = (env != null) ? Integer.parseInt(env) : 4369;
+	    }
+	    return epmdPort;
+	}	
+	public static void set(int port) {
+	    epmdPort = port;
+	}
+    }
+    // common values
+    private static final byte stopReq = (byte) 115;
+
+    // version specific value
+    private static final byte port3req = (byte) 112;
+    private static final byte publish3req = (byte) 97;
+    private static final byte publish3ok = (byte) 89;
+
+    private static final byte port4req = (byte) 122;
+    private static final byte port4resp = (byte) 119;
+    private static final byte publish4req = (byte) 120;
+    private static final byte publish4resp = (byte) 121;
+    private static final byte names4req = (byte) 110;
+
+    private static int traceLevel = 0;
+    private static final int traceThreshold = 4;
+
+    static {
+	// debug this connection?
+	final String trace = System.getProperties().getProperty(
+		"OtpConnection.trace");
+	try {
+	    if (trace != null) {
+		traceLevel = Integer.valueOf(trace).intValue();
+	    }
+	} catch (final NumberFormatException e) {
+	    traceLevel = 0;
+	}
+    }
+
+    // only static methods: no public constructors
+    // hmm, idea: singleton constructor could spawn epmd process
+    private OtpEpmd() {
+    }
+
+
+    /**
+     * Set the port number to be used to contact the epmd process.
+     * Only needed when the default port is not desired and system environment
+     * variable ERL_EPMD_PORT can not be read (applet).
+     */
+    public static void useEpmdPort(int port) {
+	EpmdPort.set(port);
+    }
+
+    /**
+     * Determine what port a node listens for incoming connections on.
+     * 
+     * @return the listen port for the specified node, or 0 if the node was not
+     *         registered with Epmd.
+     * 
+     * @exception java.io.IOException
+     *                if there was no response from the name server.
+     */
+    public static int lookupPort(final AbstractNode node) throws IOException {
+	try {
+	    return r4_lookupPort(node);
+	} catch (final IOException e) {
+	    return r3_lookupPort(node);
+	}
+    }
+
+    /**
+     * Register with Epmd, so that other nodes are able to find and connect to
+     * it.
+     * 
+     * @param node
+     *            the server node that should be registered with Epmd.
+     * 
+     * @return true if the operation was successful. False if the node was
+     *         already registered.
+     * 
+     * @exception java.io.IOException
+     *                if there was no response from the name server.
+     */
+    public static boolean publishPort(final OtpLocalNode node)
+	    throws IOException {
+	Socket s = null;
+
+	try {
+	    s = r4_publish(node);
+	} catch (final IOException e) {
+	    s = r3_publish(node);
+	}
+
+	node.setEpmd(s);
+
+	return s != null;
+    }
+
+    // Ask epmd to close his end of the connection.
+    // Caller should close his epmd socket as well.
+    // This method is pretty forgiving...
+    /**
+     * Unregister from Epmd. Other nodes wishing to connect will no longer be
+     * able to.
+     * 
+     * <p>
+     * This method does not report any failures.
+     */
+    public static void unPublishPort(final OtpLocalNode node) {
+	Socket s = null;
+
+	try {
+	    s = new Socket((String) null, EpmdPort.get());
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    obuf.write2BE(node.alive().length() + 1);
+	    obuf.write1(stopReq);
+	    obuf.writeN(node.alive().getBytes());
+	    obuf.writeTo(s.getOutputStream());
+	    // don't even wait for a response (is there one?)
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("-> UNPUBLISH " + node + " port="
+			+ node.port());
+		System.out.println("<- OK (assumed)");
+	    }
+	} catch (final Exception e) {/* ignore all failures */
+	} finally {
+	    try {
+		if (s != null) {
+		    s.close();
+		}
+	    } catch (final IOException e) { /* ignore close failure */
+	    }
+	    s = null;
+	}
+    }
+
+    private static int r3_lookupPort(final AbstractNode node)
+	    throws IOException {
+	int port = 0;
+	Socket s = null;
+
+	try {
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    s = new Socket(node.host(), EpmdPort.get());
+
+	    // build and send epmd request
+	    // length[2], tag[1], alivename[n] (length = n+1)
+	    obuf.write2BE(node.alive().length() + 1);
+	    obuf.write1(port3req);
+	    obuf.writeN(node.alive().getBytes());
+
+	    // send request
+	    obuf.writeTo(s.getOutputStream());
+
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("-> LOOKUP (r3) " + node);
+	    }
+
+	    // receive and decode reply
+	    final byte[] tmpbuf = new byte[100];
+
+	    s.getInputStream().read(tmpbuf);
+	    final OtpInputStream ibuf = new OtpInputStream(tmpbuf, 0);
+
+	    port = ibuf.read2BE();
+	} catch (final IOException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (no response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when looking up " + node.alive());
+	} catch (final OtpErlangDecodeException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (invalid response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when looking up " + node.alive());
+	} finally {
+	    try {
+		if (s != null) {
+		    s.close();
+		}
+	    } catch (final IOException e) { /* ignore close errors */
+	    }
+	    s = null;
+	}
+
+	if (traceLevel >= traceThreshold) {
+	    if (port == 0) {
+		System.out.println("<- NOT FOUND");
+	    } else {
+		System.out.println("<- PORT " + port);
+	    }
+	}
+	return port;
+    }
+
+    private static int r4_lookupPort(final AbstractNode node)
+	    throws IOException {
+	int port = 0;
+	Socket s = null;
+
+	try {
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    s = new Socket(node.host(), EpmdPort.get());
+
+	    // build and send epmd request
+	    // length[2], tag[1], alivename[n] (length = n+1)
+	    obuf.write2BE(node.alive().length() + 1);
+	    obuf.write1(port4req);
+	    obuf.writeN(node.alive().getBytes());
+
+	    // send request
+	    obuf.writeTo(s.getOutputStream());
+
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("-> LOOKUP (r4) " + node);
+	    }
+
+	    // receive and decode reply
+	    // resptag[1], result[1], port[2], ntype[1], proto[1],
+	    // disthigh[2], distlow[2], nlen[2], alivename[n],
+	    // elen[2], edata[m]
+	    final byte[] tmpbuf = new byte[100];
+
+	    final int n = s.getInputStream().read(tmpbuf);
+
+	    if (n < 0) {
+		// this was an r3 node => not a failure (yet)
+
+		s.close();
+		throw new IOException("Nameserver not responding on "
+			+ node.host() + " when looking up " + node.alive());
+	    }
+
+	    final OtpInputStream ibuf = new OtpInputStream(tmpbuf, 0);
+
+	    final int response = ibuf.read1();
+	    if (response == port4resp) {
+		final int result = ibuf.read1();
+		if (result == 0) {
+		    port = ibuf.read2BE();
+
+		    node.ntype = ibuf.read1();
+		    node.proto = ibuf.read1();
+		    node.distHigh = ibuf.read2BE();
+		    node.distLow = ibuf.read2BE();
+		    // ignore rest of fields
+		}
+	    }
+	} catch (final IOException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (no response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when looking up " + node.alive());
+	} catch (final OtpErlangDecodeException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (invalid response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when looking up " + node.alive());
+	} finally {
+	    try {
+		if (s != null) {
+		    s.close();
+		}
+	    } catch (final IOException e) { /* ignore close errors */
+	    }
+	    s = null;
+	}
+
+	if (traceLevel >= traceThreshold) {
+	    if (port == 0) {
+		System.out.println("<- NOT FOUND");
+	    } else {
+		System.out.println("<- PORT " + port);
+	    }
+	}
+	return port;
+    }
+
+    private static Socket r3_publish(final OtpLocalNode node)
+	    throws IOException {
+	Socket s = null;
+
+	try {
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    s = new Socket((String) null, EpmdPort.get());
+
+	    obuf.write2BE(node.alive().length() + 3);
+
+	    obuf.write1(publish3req);
+	    obuf.write2BE(node.port());
+	    obuf.writeN(node.alive().getBytes());
+
+	    // send request
+	    obuf.writeTo(s.getOutputStream());
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("-> PUBLISH (r3) " + node + " port="
+			+ node.port());
+	    }
+
+	    final byte[] tmpbuf = new byte[100];
+
+	    final int n = s.getInputStream().read(tmpbuf);
+
+	    if (n < 0) {
+		s.close();
+		if (traceLevel >= traceThreshold) {
+		    System.out.println("<- (no response)");
+		}
+		return null;
+	    }
+
+	    final OtpInputStream ibuf = new OtpInputStream(tmpbuf, 0);
+
+	    if (ibuf.read1() == publish3ok) {
+		node.creation = ibuf.read2BE();
+		if (traceLevel >= traceThreshold) {
+		    System.out.println("<- OK");
+		}
+		return s; // success - don't close socket
+	    }
+	} catch (final IOException e) {
+	    // epmd closed the connection = fail
+	    if (s != null) {
+		s.close();
+	    }
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (no response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when publishing " + node.alive());
+	} catch (final OtpErlangDecodeException e) {
+	    if (s != null) {
+		s.close();
+	    }
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (invalid response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when publishing " + node.alive());
+	}
+
+	if (s != null) {
+	    s.close();
+	}
+	return null; // failure
+    }
+
+    /*
+     * this function will get an exception if it tries to talk to an r3 epmd, or
+     * if something else happens that it cannot forsee. In both cases we return
+     * an exception (and the caller should try again, using the r3 protocol). If
+     * we manage to successfully communicate with an r4 epmd, we return either
+     * the socket, or null, depending on the result.
+     */
+    private static Socket r4_publish(final OtpLocalNode node)
+	    throws IOException {
+	Socket s = null;
+
+	try {
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    s = new Socket((String) null, EpmdPort.get());
+
+	    obuf.write2BE(node.alive().length() + 13);
+
+	    obuf.write1(publish4req);
+	    obuf.write2BE(node.port());
+
+	    obuf.write1(node.type());
+
+	    obuf.write1(node.proto());
+	    obuf.write2BE(node.distHigh());
+	    obuf.write2BE(node.distLow());
+
+	    obuf.write2BE(node.alive().length());
+	    obuf.writeN(node.alive().getBytes());
+	    obuf.write2BE(0); // No extra
+
+	    // send request
+	    obuf.writeTo(s.getOutputStream());
+
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("-> PUBLISH (r4) " + node + " port="
+			+ node.port());
+	    }
+
+	    // get reply
+	    final byte[] tmpbuf = new byte[100];
+	    final int n = s.getInputStream().read(tmpbuf);
+
+	    if (n < 0) {
+		// this was an r3 node => not a failure (yet)
+		if (s != null) {
+		    s.close();
+		}
+		throw new IOException("Nameserver not responding on "
+			+ node.host() + " when publishing " + node.alive());
+	    }
+
+	    final OtpInputStream ibuf = new OtpInputStream(tmpbuf, 0);
+
+	    final int response = ibuf.read1();
+	    if (response == publish4resp) {
+		final int result = ibuf.read1();
+		if (result == 0) {
+		    node.creation = ibuf.read2BE();
+		    if (traceLevel >= traceThreshold) {
+			System.out.println("<- OK");
+		    }
+		    return s; // success
+		}
+	    }
+	} catch (final IOException e) {
+	    // epmd closed the connection = fail
+	    if (s != null) {
+		s.close();
+	    }
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (no response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when publishing " + node.alive());
+	} catch (final OtpErlangDecodeException e) {
+	    if (s != null) {
+		s.close();
+	    }
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (invalid response)");
+	    }
+	    throw new IOException("Nameserver not responding on " + node.host()
+		    + " when publishing " + node.alive());
+	}
+
+	if (s != null) {
+	    s.close();
+	}
+	return null;
+    }
+
+    public static String[] lookupNames() throws IOException {
+	return lookupNames(InetAddress.getLocalHost());
+    }
+
+    public static String[] lookupNames(final InetAddress address)
+	    throws IOException {
+	Socket s = null;
+
+	try {
+	    final OtpOutputStream obuf = new OtpOutputStream();
+	    try {
+		s = new Socket(address, EpmdPort.get());
+
+		obuf.write2BE(1);
+		obuf.write1(names4req);
+		// send request
+		obuf.writeTo(s.getOutputStream());
+
+		if (traceLevel >= traceThreshold) {
+		    System.out.println("-> NAMES (r4) ");
+		}
+
+		// get reply
+		final byte[] buffer = new byte[256];
+		final ByteArrayOutputStream out = new ByteArrayOutputStream(256);
+		while (true) {
+		    final int bytesRead = s.getInputStream().read(buffer);
+		    if (bytesRead == -1) {
+			break;
+		    }
+		    out.write(buffer, 0, bytesRead);
+		}
+		final byte[] tmpbuf = out.toByteArray();
+		final OtpInputStream ibuf = new OtpInputStream(tmpbuf, 0);
+		ibuf.read4BE(); // read port int
+		// final int port = ibuf.read4BE();
+		// check if port = epmdPort
+
+		final int n = tmpbuf.length;
+		final byte[] buf = new byte[n - 4];
+		System.arraycopy(tmpbuf, 4, buf, 0, n - 4);
+		final String all = OtpErlangString.newString(buf);
+		return all.split("\n");
+	    } finally {
+		if (s != null) {
+		    s.close();
+		}
+	    }
+
+	} catch (final IOException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (no response)");
+	    }
+	    throw new IOException(
+		    "Nameserver not responding when requesting names");
+	} catch (final OtpErlangDecodeException e) {
+	    if (traceLevel >= traceThreshold) {
+		System.out.println("<- (invalid response)");
+	    }
+	    throw new IOException(
+		    "Nameserver not responding when requesting names");
+	}
+    }
+
+}