Fixed Router to actually consider hop count and hop limit.

PROTOCOL.md

@@ -91,9 +91,9 @@ MUST NOT be changed by a forwarding node.
 
 Hop Count specifies the number of nodes a message may pass. When
 creating a package, it is initialized to 0. Whenever a node forwards
-a package, it MUST increment the hop limit by one. If the hop limit
-BEFORE/AFTER? incrementing equals Hop Limit, the package MUST be
-ignored.
+a package, it MUST increment the hop limit by one. If the hop count
+after incrementing equals or is greater than Hop Limit, the package
+MUST NOT be forwarded.
 
 Length is the message size in bytes, including the header.
 

app/src/androidTest/scala/com/nutomic/ensichat/protocol/RouterTest.scala

@@ -1,9 +1,9 @@
 package com.nutomic.ensichat.protocol
 
-import java.util.GregorianCalendar
+import java.util.{Date, GregorianCalendar}
 
 import android.test.AndroidTestCase
-import com.nutomic.ensichat.protocol.body.UserName
+import com.nutomic.ensichat.protocol.body.{Text, UserName}
 import com.nutomic.ensichat.protocol.header.ContentHeader
 import junit.framework.Assert._
 
@@ -20,7 +20,6 @@ class RouterTest extends AndroidTestCase {
     var sentTo = Set[Address]()
     val router: Router = new Router(neighbors,
       (a, m) => {
-        assertEquals(msg, m)
         sentTo += a
       })
 
@@ -28,6 +27,21 @@ class RouterTest extends AndroidTestCase {
     assertEquals(neighbors(), sentTo)
   }
 
+  def testMessageSame(): Unit = {
+    val router: Router = new Router(neighbors,
+      (a, m) => {
+        assertEquals(msg.header.origin,       m.header.origin)
+        assertEquals(msg.header.target,       m.header.target)
+        assertEquals(msg.header.seqNum,       m.header.seqNum)
+        assertEquals(msg.header.protocolType, m.header.protocolType)
+        assertEquals(msg.header.hopCount + 1, m.header.hopCount)
+        assertEquals(msg.header.hopLimit,     m.header.hopLimit)
+        assertEquals(msg.body, m.body)
+        assertEquals(msg.crypto, m.crypto)
+      })
+    router.onReceive(msg)
+  }
+
   /**
    * Messages from different senders with the same sequence number should be forwarded.
    */
@@ -75,6 +89,13 @@ class RouterTest extends AndroidTestCase {
     test(ContentHeader.SeqNumRange.last / 2, 1)
   }
 
+  def testHopLimit(): Unit = Range(19, 22).foreach { i =>
+    val msg = new Message(
+      new ContentHeader(AddressTest.a1, AddressTest.a2, 1, 1, 1, new Date(), i), new Text(""))
+    val router: Router = new Router(neighbors, (a, m) => fail())
+    router.onReceive(msg)
+  }
+
   private def generateMessage(sender: Address, receiver: Address, seqNum: Int): Message = {
     val header = new ContentHeader(sender, receiver, seqNum, UserName.Type, 5,
       new GregorianCalendar(2014, 6, 10).getTime)

app/src/main/scala/com/nutomic/ensichat/protocol/Router.scala

@@ -1,6 +1,6 @@
 package com.nutomic.ensichat.protocol
 
-import com.nutomic.ensichat.protocol.header.ContentHeader
+import com.nutomic.ensichat.protocol.header.{MessageHeader, ContentHeader}
 
 /**
  * Forwards messages to all connected devices.
@@ -14,12 +14,29 @@ class Router(activeConnections: () => Set[Address], send: (Address, Message) =>
     if (messageSeen.contains(info))
       return
 
-    activeConnections().foreach(a => send(a, msg))
+    val updated = incHopCount(msg)
+    if (updated.header.hopCount >= updated.header.hopLimit)
+      return
+
+    activeConnections().foreach(a => send(a, updated))
     
     trimMessageSeen(info._1, info._2)
     messageSeen += info
   }
 
+  /**
+   * Returns msg with hop count increased by one.
+   */
+  private def incHopCount(msg: Message): Message = {
+    val updatedHeader = msg.header match {
+      case ch: ContentHeader => new ContentHeader(ch.origin, ch.target, ch.seqNum, ch.contentType,
+                                    ch.messageId, ch.time, ch.hopCount + 1, ch.hopLimit)
+      case mh: MessageHeader => new MessageHeader(mh.protocolType, mh.origin, mh.target, mh.seqNum,
+                                    mh.hopCount + 1, mh.hopLimit)
+    }
+    new Message(updatedHeader, msg.crypto, msg.body)
+  }
+
   /**
    * Removes old entries from [[messageSeen]].
    *

app/src/main/scala/com/nutomic/ensichat/protocol/header/ContentHeader.scala

@@ -45,13 +45,12 @@ case class ContentHeader(override val origin: Address,
                     contentType: Int,
                     messageId: Long,
                     time: Date,
-                    override val hopCount: Int = 0)
+                    override val hopCount: Int = 0,
+                    override val hopLimit: Int = AbstractHeader.DefaultHopLimit)
   extends AbstractHeader {
 
   override val protocolType = ContentHeader.ContentMessageType
 
-  override val hopLimit = AbstractHeader.DefaultHopLimit
-
   /**
    * Writes the header to byte array.
    */