1 files changed, 76 insertions, 0 deletions
diff --git a/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/config/SubnetMatcher.java b/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/config/SubnetMatcher.java
new file mode 100644
index 00000000..602c283e
--- /dev/null
+++ b/datarouter-node/src/main/java/org/onap/dmaap/datarouter/node/config/SubnetMatcher.java
@@ -0,0 +1,76 @@
+/*******************************************************************************
+ * ============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 org.onap.dmaap.datarouter.node.config;
+
+import org.onap.dmaap.datarouter.node.utils.NodeUtils;
+
+/**
+ * Compare IP addresses as byte arrays to a subnet specified as a CIDR.
+ */
+public class SubnetMatcher {
+
+    private byte[] sn;
+    private int len;
+    private int mask;
+
+    /**
+     * Construct a subnet matcher given a CIDR.
+     *
+     * @param subnet The CIDR to match
+     */
+    public SubnetMatcher(String subnet) {
+        int index = subnet.lastIndexOf('/');
+        if (index == -1) {
+            sn = NodeUtils.getInetAddress(subnet);
+            len = sn.length;
+        } else {
+            len = Integer.parseInt(subnet.substring(index + 1));
+            sn = NodeUtils.getInetAddress(subnet.substring(0, index));
+            mask = ((0xff00) >> (len % 8)) & 0xff;
+            len /= 8;
+        }
+    }
+
+    /**
+     * Is the IP address in the CIDR.
+     *
+     * @param addr the IP address as bytes in network byte order
+     * @return true if the IP address matches.
+     */
+    public boolean matches(byte[] addr) {
+        if (addr.length != sn.length) {
+            return (false);
+        }
+        for (int i = 0; i < len; i++) {
+            if (addr[i] != sn[i]) {
+                return (false);
+            }
+        }
+        if (mask != 0 && ((addr[len] ^ sn[len]) & mask) != 0) {
+            return (false);
+        }
+        return (true);
+    }
+}