From 021c91a082ea8c5f22b368ddca3926d97101279c Mon Sep 17 00:00:00 2001
From: Brian Demsky <bdemsky@plrg.eecs.uci.edu>
Date: Fri, 22 Jul 2016 23:52:16 -0700
Subject: [PATCH] more code

---
 src/java/iotcloud/Entry.java           | 28 ++++++++++-
 src/java/iotcloud/KeyValue.java        | 29 ++++++++++-
 src/java/iotcloud/LastMessage.java     | 25 +++++++++-
 src/java/iotcloud/RejectedMessage.java | 30 +++++++++++-
 src/java/iotcloud/Slot.java            | 68 +++++++++++++++++++++++---
 src/java/iotcloud/Table.java           |  6 +++
 src/java/iotcloud/TableStatus.java     | 24 +++++++++
 src/server/iotquery.cpp                |  4 ++
 8 files changed, 202 insertions(+), 12 deletions(-)
 create mode 100644 src/java/iotcloud/Table.java
 create mode 100644 src/java/iotcloud/TableStatus.java

diff --git a/src/java/iotcloud/Entry.java b/src/java/iotcloud/Entry.java
index 0e6d43d..9f85bac 100644
--- a/src/java/iotcloud/Entry.java
+++ b/src/java/iotcloud/Entry.java
@@ -1,5 +1,29 @@
 package iotcloud;
+import java.nio.ByteBuffer;
 
-public abstract class Entry {
-	
+abstract class Entry {
+	static final byte TypeKeyValue = 1;
+	static final byte TypeLastMessage = 2;
+	static final byte TypeRejectedMessage = 3;
+	static final byte TypeTableStatus = 4;
+
+	static Entry decode(ByteBuffer bb) {
+		byte type=bb.get();
+		switch(type) {
+		case TypeKeyValue:
+			return KeyValue.decode(bb);
+		case TypeLastMessage:
+			return LastMessage.decode(bb);
+		case TypeRejectedMessage:
+			return RejectedMessage.decode(bb);
+		case TypeTableStatus:
+			return TableStatus.decode(bb);
+		default:
+			throw new Error("Unrecognized Entry Type: "+type);
+		}
+	}
+
+	abstract void encode(ByteBuffer bb);
+
+	abstract int getSize();
 }
diff --git a/src/java/iotcloud/KeyValue.java b/src/java/iotcloud/KeyValue.java
index fd74dc1..39125e2 100644
--- a/src/java/iotcloud/KeyValue.java
+++ b/src/java/iotcloud/KeyValue.java
@@ -1,6 +1,33 @@
 package iotcloud;
+import java.nio.ByteBuffer;
 
-public class KeyValue extends Entry {
+class KeyValue extends Entry {
+	byte[] key;
+	byte[] value;
+	KeyValue(byte[] _key, byte[] _value) {
+		key=_key;
+		value=_value;
+	}
 	
+	static Entry decode(ByteBuffer bb) {
+		int keylength=bb.getInt();
+		int valuelength=bb.getInt();
+		byte[] key=new byte[keylength];
+		byte[] value=new byte[valuelength];
+		bb.get(key);
+		bb.get(value);
+		return new KeyValue(key, value);
+	}
 
+	void encode(ByteBuffer bb) {
+		bb.put(Entry.TypeKeyValue);
+		bb.putInt(key.length);
+		bb.putInt(value.length);
+		bb.put(key);
+		bb.put(value);
+	}
+
+	int getSize() {
+		return 2*Integer.BYTES+key.length+value.length+Byte.BYTES;
+	}
 }
diff --git a/src/java/iotcloud/LastMessage.java b/src/java/iotcloud/LastMessage.java
index ad1f273..023608b 100644
--- a/src/java/iotcloud/LastMessage.java
+++ b/src/java/iotcloud/LastMessage.java
@@ -1,6 +1,29 @@
 package iotcloud;
 
-public class LastMessage extends Entry {
+import java.nio.ByteBuffer;
 
+class LastMessage extends Entry {
+	private long machineid;
+	private long seqnum;
+	
+	LastMessage(long _machineid, long _seqnum) {
+		machineid=_machineid;
+		seqnum=_seqnum;
+	}
 
+	static Entry decode(ByteBuffer bb) {
+		long machineid=bb.getLong();
+		long seqnum=bb.getLong();
+		return new LastMessage(machineid, seqnum);
+	}
+
+	void encode(ByteBuffer bb) {
+		bb.put(Entry.TypeLastMessage);
+		bb.putLong(machineid);
+		bb.putLong(seqnum);
+	}
+	
+	int getSize() {
+		return 2*Long.BYTES+Byte.BYTES;
+	}
 }
diff --git a/src/java/iotcloud/RejectedMessage.java b/src/java/iotcloud/RejectedMessage.java
index f74c0c1..6a080b7 100644
--- a/src/java/iotcloud/RejectedMessage.java
+++ b/src/java/iotcloud/RejectedMessage.java
@@ -1,6 +1,32 @@
 package iotcloud;
+import java.nio.ByteBuffer;
 
-public class RejectedMessage extends Entry {
-
+class RejectedMessage extends Entry {
+	private long machineid;
+	private long seqnum;
+	private boolean equalto;
 
+	RejectedMessage(long _machineid, long _seqnum, boolean _equalto) {
+		machineid=_machineid;
+		seqnum=_seqnum;
+		equalto=_equalto;
+	}
+	
+	static Entry decode(ByteBuffer bb) {
+		long machineid=bb.getLong();
+		long seqnum=bb.getLong();
+		byte equalto=bb.get();
+		return new RejectedMessage(machineid, seqnum, equalto==1);
+	}
+	
+	void encode(ByteBuffer bb) {
+		bb.put(Entry.TypeRejectedMessage);
+		bb.putLong(machineid);
+		bb.putLong(seqnum);
+		bb.put(equalto?(byte)1:(byte)0);
+	}
+	
+	int getSize() {
+		return 2*Long.BYTES + 2*Byte.BYTES;
+	}
 }
diff --git a/src/java/iotcloud/Slot.java b/src/java/iotcloud/Slot.java
index 33a8908..8d12fc2 100644
--- a/src/java/iotcloud/Slot.java
+++ b/src/java/iotcloud/Slot.java
@@ -1,19 +1,75 @@
 package iotcloud;
 import java.util.Vector;
+import java.nio.ByteBuffer;
+import javax.crypto.Mac;
+import java.util.Arrays;
 
 class Slot {
+	public static final int SLOT_SIZE=2048;
+	public static final int HMAC_SIZE=32;
+
 	long seqnum;
-	byte[] bytes;
+	byte[] prevhmac;
+	byte[] hmac;
+	long machineid;
 	Vector<Entry> entries;
 
-	Slot() {
-		entries=new Vector();
+	Slot(Vector _entries) {
+		entries=_entries;
+	}
+
+	Slot(long _seqnum, long _machineid, byte[] _prevhmac, byte[] _hmac, Vector<Entry> _entries) {
+		seqnum=_seqnum;
+		machineid=_machineid;
+		prevhmac=_prevhmac;
+		hmac=_hmac;
+		entries=_entries;
 	}
 	
 	Slot(long _seqnum, byte[] _bytes) {
-		this();
 		seqnum=_seqnum;
-		bytes=_bytes;
+	}
+
+	static Slot decode(byte[] array, Mac mac) {
+		mac.update(array, HMAC_SIZE, array.length-HMAC_SIZE);
+		byte[] realmac=mac.doFinal();
+
+		ByteBuffer bb=ByteBuffer.wrap(array);
+		byte[] hmac=new byte[HMAC_SIZE];
+		byte[] prevhmac=new byte[HMAC_SIZE];
+		bb.get(hmac);
+		bb.get(prevhmac);
+		if (!Arrays.equals(realmac, hmac))
+			throw new Error("Invalid HMAC!  Potential Attack!");
+
+		long seqnum=bb.getLong();
+		long machineid=bb.getLong();
+		int numentries=bb.getInt();
+		Vector<Entry> entries=new Vector();
+		for(int i=0;i<numentries;i++) {
+			entries.add(Entry.decode(bb));
+		}
+		
+		return new Slot(seqnum, machineid, prevhmac, hmac, entries);
+	}
+
+	byte[] encode(Mac mac) {
+		byte[] array=new byte[SLOT_SIZE];
+		ByteBuffer bb=ByteBuffer.wrap(array);
+		bb.position(HMAC_SIZE); //Leave space for the HMACs
+		bb.put(prevhmac);
+		bb.putLong(seqnum);
+		bb.putLong(machineid);
+		bb.putInt(entries.size());
+		for(Entry entry:entries) {
+			entry.encode(bb);
+		}
+		//Compute our HMAC
+		mac.update(array, HMAC_SIZE, array.length-HMAC_SIZE);
+		byte[] realmac=mac.doFinal();
+		bb.position(0);
+		bb.put(realmac);
+		return array;
 	}
 	
 	long getSequenceNumber() {
@@ -21,7 +77,7 @@ class Slot {
 	}
 
 	byte[] getBytes() {
-		return bytes;
+		return null;
 	}
 	
 	public String toString() {
diff --git a/src/java/iotcloud/Table.java b/src/java/iotcloud/Table.java
new file mode 100644
index 0000000..beceb7c
--- /dev/null
+++ b/src/java/iotcloud/Table.java
@@ -0,0 +1,6 @@
+package iotcloud;
+
+public class Table {
+	int tablesize;
+	
+}
diff --git a/src/java/iotcloud/TableStatus.java b/src/java/iotcloud/TableStatus.java
new file mode 100644
index 0000000..27f9017
--- /dev/null
+++ b/src/java/iotcloud/TableStatus.java
@@ -0,0 +1,24 @@
+package iotcloud;
+import java.nio.ByteBuffer;
+
+class TableStatus extends Entry {
+	int maxslots;
+	
+	TableStatus(int _maxslots) {
+		maxslots=_maxslots;
+	}
+	
+	static Entry decode(ByteBuffer bb) {
+		int maxslots=bb.getInt();
+		return new TableStatus(maxslots);
+	}
+
+	void encode(ByteBuffer bb) {
+		bb.put(Entry.TypeTableStatus);
+		bb.putInt(maxslots);
+	}
+
+	int getSize() {
+		return Integer.BYTES+Byte.BYTES;
+	}
+}
diff --git a/src/server/iotquery.cpp b/src/server/iotquery.cpp
index 9ab3f27..0dac1f7 100644
--- a/src/server/iotquery.cpp
+++ b/src/server/iotquery.cpp
@@ -75,6 +75,10 @@ void IoTQuery::decodeQuery() {
 			requestsequencenumber = strtoll(sequencenumber_str + 1, NULL, 10);
 		}
 	}
+
+	//don't allow a really old sequence number
+	if (requestsequencenumber < oldestentry)
+		requestsequencenumber = oldestentry;
 	
 	/* Update size if we get request */
 	char * numqueueentries_str = tok_ptr;
-- 
2.34.1