1 files changed, 215 insertions, 0 deletions

diff --git a/src/org/xbill/DNS/EDNSOption.java b/src/org/xbill/DNS/EDNSOption.java
new file mode 100644
index 0000000..a65bd19
--- /dev/null
+++ b/src/org/xbill/DNS/EDNSOption.java
@@ -0,0 +1,215 @@
+// Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org)
+package org.xbill.DNS;
+
+import java.io.*;
+import java.util.Arrays;
+
+/**
+ * DNS extension options, as described in RFC 2671.  The rdata of an OPT record
+ * is defined as a list of options; this represents a single option.
+ * 
+ * @author Brian Wellington
+ * @author Ming Zhou <mizhou@bnivideo.com>, Beaumaris Networks
+ */
+public abstract class EDNSOption {
+
+public static class Code {
+	private Code() {}
+
+	/** Name Server Identifier, RFC 5001 */
+	public final static int NSID = 3;
+
+	/** Client Subnet, defined in draft-vandergaast-edns-client-subnet-00 */
+	public final static int CLIENT_SUBNET = 20730;
+
+	private static Mnemonic codes = new Mnemonic("EDNS Option Codes",
+						     Mnemonic.CASE_UPPER);
+
+	static {
+		codes.setMaximum(0xFFFF);
+		codes.setPrefix("CODE");
+		codes.setNumericAllowed(true);
+
+		codes.add(NSID, "NSID");
+		codes.add(CLIENT_SUBNET, "CLIENT_SUBNET");
+	}
+
+	/**
+	 * Converts an EDNS Option Code into its textual representation
+	 */
+	public static String
+	string(int code) {
+		return codes.getText(code);
+	}
+
+	/**
+	 * Converts a textual representation of an EDNS Option Code into its
+	 * numeric value.
+	 * @param s The textual representation of the option code
+	 * @return The option code, or -1 on error.
+	 */
+	public static int
+	value(String s) {
+		return codes.getValue(s);
+	}
+}
+
+private final int code;
+
+/**
+ * 
+ * Creates an option with the given option code and data.
+ */
+public 
+EDNSOption(int code) {
+	this.code = Record.checkU16("code", code);
+}
+
+public String 
+toString() {
+	StringBuffer sb = new StringBuffer();
+
+	sb.append("{");
+	sb.append(EDNSOption.Code.string(code));
+	sb.append(": ");
+	sb.append(optionToString());
+	sb.append("}");
+
+	return sb.toString();
+}
+
+/**
+ * Returns the EDNS Option's code.
+ *
+ * @return the option code
+ */
+public int 
+getCode() {
+	return code;
+}
+
+/**
+ * Returns the EDNS Option's data, as a byte array.
+ * 
+ * @return the option data
+ */
+byte [] 
+getData() {
+	DNSOutput out = new DNSOutput();
+	optionToWire(out);
+	return out.toByteArray();
+}
+
+/**
+ * Converts the wire format of an EDNS Option (the option data only) into the
+ * type-specific format.
+ * @param in The input Stream.
+ */
+abstract void 
+optionFromWire(DNSInput in) throws IOException;
+
+/**
+ * Converts the wire format of an EDNS Option (including code and length) into
+ * the type-specific format.
+ * @param out The input stream.
+ */
+static EDNSOption
+fromWire(DNSInput in) throws IOException {
+	int code, length;
+
+	code = in.readU16();
+	length = in.readU16();
+	if (in.remaining() < length)
+		throw new WireParseException("truncated option");
+	int save = in.saveActive();
+	in.setActive(length);
+	EDNSOption option;
+	switch (code) {
+	case Code.NSID:
+		option = new NSIDOption();
+		break;
+	case Code.CLIENT_SUBNET:
+		option = new ClientSubnetOption();
+		break;
+	default:
+		option = new GenericEDNSOption(code);
+		break;
+	}
+	option.optionFromWire(in);
+	in.restoreActive(save);
+
+	return option;
+}
+
+/**
+ * Converts the wire format of an EDNS Option (including code and length) into
+ * the type-specific format.
+ * @return The option, in wire format.
+ */
+public static EDNSOption
+fromWire(byte [] b) throws IOException {
+	return fromWire(new DNSInput(b));
+}
+
+/**
+ * Converts an EDNS Option (the type-specific option data only) into wire format.
+ * @param out The output stream.
+ */
+abstract void 
+optionToWire(DNSOutput out);
+
+/**
+ * Converts an EDNS Option (including code and length) into wire format.
+ * @param out The output stream.
+ */
+void
+toWire(DNSOutput out) {
+	out.writeU16(code);
+	int lengthPosition = out.current();
+	out.writeU16(0); /* until we know better */
+	optionToWire(out);
+	int length = out.current() - lengthPosition - 2;
+	out.writeU16At(length, lengthPosition);
+}
+
+/**
+ * Converts an EDNS Option (including code and length) into wire format.
+ * @return The option, in wire format.
+ */
+public byte []
+toWire() throws IOException {
+	DNSOutput out = new DNSOutput();
+	toWire(out);
+	return out.toByteArray();
+}
+
+/**
+ * Determines if two EDNS Options are identical.
+ * @param arg The option to compare to
+ * @return true if the options are equal, false otherwise.
+ */
+public boolean
+equals(Object arg) {
+	if (arg == null || !(arg instanceof EDNSOption))
+		return false;
+	EDNSOption opt = (EDNSOption) arg;
+	if (code != opt.code)
+		return false;
+	return Arrays.equals(getData(), opt.getData());
+}
+
+/**
+ * Generates a hash code based on the EDNS Option's data.
+ */
+public int
+hashCode() {
+	byte [] array = getData();
+	int hashval = 0;
+	for (int i = 0; i < array.length; i++)
+		hashval += ((hashval << 3) + (array[i] & 0xFF));
+	return hashval;
+}
+
+abstract String optionToString();
+
+}