1 files changed, 82 insertions, 0 deletions
diff --git a/datarouter-node/src/main/java/com/att/research/datarouter/node/IsFrom.java b/datarouter-node/src/main/java/com/att/research/datarouter/node/IsFrom.java
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+++ b/datarouter-node/src/main/java/com/att/research/datarouter/node/IsFrom.java
@@ -0,0 +1,82 @@
+/*******************************************************************************
+ * ============LICENSE_START==================================================
+ * * org.onap.dmaap
+ * * ===========================================================================
+ * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ * * ===========================================================================
+ * * Licensed under the Apache License, Version 2.0 (the "License");
+ * * you may not use this file except in compliance with the License.
+ * * You may obtain a copy of the License at
+ * * 
+ *  *      http://www.apache.org/licenses/LICENSE-2.0
+ * * 
+ *  * Unless required by applicable law or agreed to in writing, software
+ * * distributed under the License is distributed on an "AS IS" BASIS,
+ * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * * See the License for the specific language governing permissions and
+ * * limitations under the License.
+ * * ============LICENSE_END====================================================
+ * *
+ * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ * *
+ ******************************************************************************/
+
+
+package com.att.research.datarouter.node;
+
+import java.util.*;
+import java.net.*;
+
+/**
+ *	Determine if an IP address is from a machine
+ */
+public class IsFrom	{
+	private long	nextcheck;
+	private String[] ips;
+	private String	fqdn;
+	/**
+	 *	Configure the JVM DNS cache to have a 10 second TTL.  This needs to be called very very early or it won't have any effect.
+	 */
+	public static void setDNSCache() {
+		java.security.Security.setProperty("networkaddress.cache.ttl", "10");
+	}
+	/**
+	 *	Create an IsFrom for the specified fully qualified domain name.
+	 */
+	public IsFrom(String fqdn) {
+		this.fqdn = fqdn;
+	}
+	/**
+	 *	Check if an IP address matches.  If it has been more than
+	 *	10 seconds since DNS was last checked for changes to the
+	 *	IP address(es) of this FQDN, check again.  Then check
+	 *	if the specified IP address belongs to the FQDN.
+	 */
+	public synchronized boolean isFrom(String ip) {
+		long now = System.currentTimeMillis();
+		if (now > nextcheck) {
+			nextcheck = now + 10000;
+			Vector<String> v = new Vector<String>();
+			try {
+				InetAddress[] addrs = InetAddress.getAllByName(fqdn);
+				for (InetAddress a: addrs) {
+					v.add(a.getHostAddress());
+				}
+			} catch (Exception e) {
+			}
+			ips = v.toArray(new String[v.size()]);
+		}
+		for (String s: ips) {
+			if (s.equals(ip)) {
+				return(true);
+			}
+		}
+		return(false);
+	}
+	/**
+	 *	Return the fully qualified domain name
+	 */
+	public String toString() {
+		return(fqdn);
+	}
+}