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8001033: Refactor network address handling in virtual machine identifiers

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Reviewed-by: smarks, hawtin, mchung
This commit is contained in:
Darryl Mocek 2013-03-13 17:24:34 -07:00
parent ebbaaa0f18
commit 3cf0ad20be
1 changed files with 13 additions and 56 deletions
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69
jdk/src/share/classes/java/rmi/dgc/VMID.java
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@ -1,5 +1,5 @@
/* /*
* Copyright (c) 1996, 2011, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* *
* This code is free software; you can redistribute it and/or modify it * This code is free software; you can redistribute it and/or modify it
@ -25,10 +25,8 @@
package java.rmi.dgc; package java.rmi.dgc;
import java.io.*;
import java.net.*;
import java.rmi.server.UID; import java.rmi.server.UID;
import java.security.*; import java.security.SecureRandom;
/** /**
* A VMID is a identifier that is unique across all Java virtual * A VMID is a identifier that is unique across all Java virtual
@ -39,9 +37,8 @@ import java.security.*;
* @author Peter Jones * @author Peter Jones
*/ */
public final class VMID implements java.io.Serializable { public final class VMID implements java.io.Serializable {
/** Array of bytes uniquely identifying this host */
/** array of bytes uniquely identifying this host */ private static final byte[] randomBytes;
private static byte[] localAddr = computeAddressHash();
/** /**
* @serial array of bytes uniquely identifying host created on * @serial array of bytes uniquely identifying host created on
@ -56,6 +53,14 @@ public final class VMID implements java.io.Serializable {
/** indicate compatibility with JDK 1.1.x version of class */ /** indicate compatibility with JDK 1.1.x version of class */
private static final long serialVersionUID = -538642295484486218L; private static final long serialVersionUID = -538642295484486218L;
static {
// Generate 8 bytes of random data.
SecureRandom secureRandom = new SecureRandom();
byte bytes[] = new byte[8];
secureRandom.nextBytes(bytes);
randomBytes = bytes;
}
/** /**
* Create a new VMID. Each new VMID returned from this constructor * Create a new VMID. Each new VMID returned from this constructor
* is unique for all Java virtual machines under the following * is unique for all Java virtual machines under the following
@ -65,7 +70,7 @@ public final class VMID implements java.io.Serializable {
* for the lifetime of this object. <p> * for the lifetime of this object. <p>
*/ */
public VMID() { public VMID() {
addr = localAddr; addr = randomBytes;
uid = new UID(); uid = new UID();
} }
@ -126,52 +131,4 @@ public final class VMID implements java.io.Serializable {
result.append(uid.toString()); result.append(uid.toString());
return result.toString(); return result.toString();
} }
/**
* Compute the hash an IP address. The hash is the first 8 bytes
* of the SHA digest of the IP address.
*/
private static byte[] computeAddressHash() {
/*
* Get the local host's IP address.
*/
byte[] addr = java.security.AccessController.doPrivileged(
new PrivilegedAction<byte[]>() {
public byte[] run() {
try {
return InetAddress.getLocalHost().getAddress();
} catch (Exception e) {
}
return new byte[] { 0, 0, 0, 0 };
}
});
byte[] addrHash;
final int ADDR_HASH_LENGTH = 8;
try {
/*
* Calculate message digest of IP address using SHA.
*/
MessageDigest md = MessageDigest.getInstance("SHA");
ByteArrayOutputStream sink = new ByteArrayOutputStream(64);
DataOutputStream out = new DataOutputStream(
new DigestOutputStream(sink, md));
out.write(addr, 0, addr.length);
out.flush();
byte digest[] = md.digest();
int hashlength = Math.min(ADDR_HASH_LENGTH, digest.length);
addrHash = new byte[hashlength];
System.arraycopy(digest, 0, addrHash, 0, hashlength);
} catch (IOException ignore) {
/* can't happen, but be deterministic anyway. */
addrHash = new byte[0];
} catch (NoSuchAlgorithmException complain) {
throw new InternalError(complain.toString(), complain);
}
return addrHash;
}
} }