init project 2

.gitignore

+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
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.idea/.gitignore

+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/encodings.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+  </component>
+</project>
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.idea/misc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_18" default="true" project-jdk-name="18" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.internetworking</groupId>
+    <artifactId>InternetworkingWS23</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>18</maven.compiler.source>
+        <maven.compiler.target>18</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-junit-jupiter</artifactId>
+            <version>4.6.1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-inline</artifactId>
+            <version>4.6.1</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.9.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.9.0</version>
+        </dependency>
+    </dependencies>
+
+</project>
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src/main/java/apps/CPClient.java

+package apps;
+
+import cp.*;
+import exceptions.*;
+import phy.*;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.InetAddress;
+
+public class CPClient {
+    private static final String SERVER_NAME = "localhost";
+
+
+    public static void main(String[] args) {
+        // Each client needs to start on a unique UDP port provided by the user
+        if (args.length != 1) {
+            System.out.println("Provide an address identifier (int) from range [5000:65534]");
+            return;
+        }
+        var id = Integer.parseInt(args[0]);
+        if (id < 5000 || id > 65534) {
+            System.out.println("Invalid address identifier! Range [5000:65534]");
+            return;
+        }
+
+        // Set up the virtual link protocol
+        PhyProtocol phy = new PhyProtocol(id);
+
+        // Set up command protocol
+        CPProtocol cp = null;
+        try {
+            cp = new CPProtocol(InetAddress.getByName(SERVER_NAME), CPServer.SERVER_PORT, phy);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        // Read data from user to send to server
+        BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));
+        boolean eof = false;
+        while (!eof) {
+            try {
+                String sentence = null;
+                System.out.println("Command: ");
+                sentence = inFromUser.readLine();
+                // Currently only these two commands are supported by the specification
+                if(!(sentence.equals("status") || sentence.startsWith("print")))
+                    continue;
+
+                cp.send(sentence.trim(), null);
+                System.out.println("Command sent to server ... wating for response");
+                String answer = cp.receive().getData();
+                System.out.println(answer);
+            } catch (IllegalCommandException e) {
+                System.out.println("Only these two commands are supported: status, print \"text\"");
+            } catch (IWProtocolException | IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}

src/main/java/apps/CPServer.java

+package apps;
+
+import core.Msg;
+import cp.CPProtocol;
+import exceptions.IWProtocolException;
+import phy.PhyProtocol;
+
+import java.io.IOException;
+
+public class CPServer {
+    protected static final int SERVER_PORT = 3027;
+
+    public static void main(String[] args) {
+        // Set up the virtual link protocol
+        PhyProtocol phy = new PhyProtocol(SERVER_PORT);
+
+        // Set up command protocol
+        CPProtocol cp = null;
+        try {
+            cp = new CPProtocol(phy);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        // Start server processing
+        boolean eof = false;
+        while (!eof) {
+            try {
+                Msg msg = cp.receive();
+                String sentence = msg.getData().trim();
+                System.out.println("Received message: " + sentence);
+            } catch (IOException e) {
+                e.printStackTrace();
+            }
+        }
+    }
+}
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src/main/java/core/Configuration.java

+package core;
+
+/*
+ * Abstract configuration class
+ * nextLowerProtocol attribute is currently unused (ignore)
+ */
+public class Configuration {
+	protected Protocol nextLowerProtocol;
+	
+	public Configuration(Protocol proto) {
+		this.nextLowerProtocol = proto;
+	}
+
+	public Protocol getNextLowerProtocol() {
+		return nextLowerProtocol;
+	}
+
+	private void setNextLowerProtocol(Protocol nextLowerProtocol) {
+		this.nextLowerProtocol = nextLowerProtocol;
+	}
+}

src/main/java/core/Msg.java

+package core;
+
+import exceptions.IWProtocolException;
+
+/* 
+ * Msg base class (abstract)
+ */
+public abstract class Msg {
+	protected String data;
+	protected byte[] dataBytes;
+	protected Configuration config;
+	
+	public byte[] getDataBytes() {
+		return this.dataBytes;
+	}
+	
+	public int getLength() {
+		return this.dataBytes.length;
+	}
+	
+	public String getData() {
+		return this.data;
+	}
+	
+	public void setData(String data) {
+		this.data = data;
+	}
+	
+	public Configuration getConfiguration() {
+		return this.config;
+	}
+	public void setConfiguration(Configuration c) {this.config = c;}
+	
+	protected abstract void create(String sentence);
+	protected abstract Msg parse(String sentence) throws IWProtocolException;
+	
+	
+	public void printDataBytes() {
+		String msgString = new String(this.dataBytes);
+		System.out.println(msgString);
+	}
+}

src/main/java/core/Protocol.java

+package core;
+
+import java.io.IOException;
+
+import exceptions.IWProtocolException;
+
+/*
+ * Protocol base class (abstract)
+ */
+public abstract class Protocol {
+	public enum proto_id {
+		PHY, APP, SLP, CP
+	}
+
+	public abstract void send(String s, Configuration config) throws IOException, IWProtocolException;
+	public abstract Msg receive() throws IOException, IWProtocolException;
+
+}

src/main/java/cp/CPCookieRequestMsg.java

+package cp;
+
+import core.Msg;
+import exceptions.IllegalMsgException;
+
+class CPCookieRequestMsg extends CPMsg {
+    protected static final String CP_CREQ_HEADER = "creq";
+
+    /*
+     * Create cookie request message.
+     * The cp header is prepended in the super-class.
+     */
+    @Override
+    protected void create(String data) {
+        // prepend reg header
+        data = CP_CREQ_HEADER;
+        // super class prepends slp header
+        super.create(data);
+    }
+
+    @Override
+    protected Msg parse(String sentence) throws IllegalMsgException {
+        if (!sentence.startsWith(CP_CREQ_HEADER)) {
+            throw new IllegalMsgException();
+        }
+        return this;
+    }
+}
\ No newline at end of file

src/main/java/cp/CPCookieResponseMsg.java

+package cp;
+
+import core.Msg;
+import exceptions.IllegalMsgException;
+
+class CPCookieResponseMsg extends CPMsg {
+    protected static final String CP_CRES_HEADER = "cres";
+    private boolean success;
+
+    protected CPCookieResponseMsg() {
+
+    }
+    protected CPCookieResponseMsg(boolean s) {
+        this.success = s;
+    }
+
+    protected boolean getSuccess() {return this.success;}
+
+    /*
+     * Create cookie request message.
+     * The cp header is prepended in the super-class.
+     */
+    @Override
+    protected void create(String data) {
+        if (this.success) {
+            // prepend cres header
+            data = CP_CRES_HEADER + " ACK " + data;
+        } else {
+            data = CP_CRES_HEADER + " NAK " + data;
+        }
+        // super class prepends slp header
+        super.create(data);
+    }
+
+    protected Msg parse(String sentence) throws IllegalMsgException {
+        if (!sentence.startsWith(CP_CRES_HEADER)) {
+            throw new IllegalMsgException();
+        }
+        String[] parts = sentence.split("\\s+", 3);
+
+        if(parts[1].equals("ACK"))
+            this.success = true;
+        else
+            this.success = false;
+
+        this.data = parts[2];
+        return this;
+    }
+
+}

src/main/java/cp/CPMsg.java

+package cp;
+
+import core.Msg;
+import exceptions.IWProtocolException;
+import exceptions.IllegalMsgException;
+
+import java.util.zip.CRC32;
+import java.util.zip.Checksum;
+
+class CPMsg extends Msg {
+    protected static final String CP_HEADER = "cp";
+    @Override
+    protected void create(String sentence) {
+        this.data = sentence;
+        data = CP_HEADER + " " + sentence;
+        this.dataBytes = data.getBytes();
+    }
+
+    @Override
+    protected Msg parse(String sentence) throws IWProtocolException {
+        CPMsg parsedMsg;
+        if(!sentence.startsWith(CP_HEADER))
+            throw new IllegalMsgException();
+
+        String[] parts = sentence.split("\\s+", 2);
+        if(parts[1].startsWith(CPCookieRequestMsg.CP_CREQ_HEADER)) {
+            parsedMsg = new CPCookieRequestMsg();
+        } else if(parts[1].startsWith(CPCookieResponseMsg.CP_CRES_HEADER)) {
+            parsedMsg = new CPCookieResponseMsg();
+        } else
+            throw new IllegalMsgException();
+
+        parsedMsg = (CPMsg) parsedMsg.parse(parts[1]);
+        return parsedMsg;
+    }
+
+}

src/main/java/cp/CPProtocol.java

+package cp;
+
+import core.*;
+import exceptions.*;
+import phy.*;
+
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.SocketTimeoutException;
+import java.net.UnknownHostException;
+import java.util.HashMap;
+import java.util.Random;
+
+public class CPProtocol extends Protocol {
+    private static final int CP_TIMEOUT = 2000;
+    private static final int CP_HASHMAP_SIZE = 20;
+    private String cookie;
+    private int id;
+    private PhyConfiguration PhyConfig;
+    private PhyProtocol PhyProto;
+    boolean isClient;
+    HashMap<PhyConfiguration, Integer> cookieMap;
+    Random rnd;
+
+    // Constructor for clients
+    public CPProtocol(InetAddress rname, int rp, PhyProtocol phyP) throws UnknownHostException {
+        this.PhyConfig = new PhyConfiguration(rname, rp, proto_id.CP);
+        this.PhyProto = phyP;
+        this.isClient = true;
+    }
+    // Constructor for servers
+    public CPProtocol(PhyProtocol phyP) {
+        this.PhyProto = phyP;
+        this.isClient = false;
+        this.cookieMap = new HashMap<>();
+        this.rnd = new Random();
+    }
+    @Override
+    public void send(String s, Configuration config) throws IOException, IWProtocolException {
+        if (cookie == null) {
+            // Request a new cookie from server
+            // Either updates the cookie attribute or returns with an exception
+            requestCookie(0);
+        }
+    }
+
+    @Override
+    public Msg receive() throws IOException {
+        return null;
+    }
+
+
+     public void requestCookie(int count) throws IOException, IWProtocolException {
+        if(count >= 3)
+            throw new CookieRequestException();
+        CPCookieRequestMsg reqMsg = new CPCookieRequestMsg();
+        reqMsg.create(null);
+
+        this.PhyProto.send(new String (reqMsg.getDataBytes()), this.PhyConfig);
+        Msg resMsg = new CPMsg();
+
+        try {
+            Msg in = this.PhyProto.receive(CP_TIMEOUT);
+            if (((PhyConfiguration)in.getConfiguration()).getPid() != proto_id.CP)
+                throw new IllegalMsgException();
+            resMsg = ((CPMsg) resMsg).parse(in.getData());
+        } catch (SocketTimeoutException e) {
+            requestCookie(count+1);
+        }
+
+        if(resMsg instanceof CPCookieResponseMsg && !((CPCookieResponseMsg) resMsg).getSuccess()) {
+            throw new CookieRequestException();
+        }
+        this.cookie = resMsg.getData();
+    }
+}

src/main/java/exceptions/BadChecksumException.java

+package exceptions;
+
+public class BadChecksumException extends IWProtocolException {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = -6481772554012497583L;
+
+}

src/main/java/exceptions/CookieRequestException.java

+package exceptions;
+
+public class CookieRequestException extends IWProtocolException {
+}

src/main/java/exceptions/IWProtocolException.java

+package exceptions;
+
+public abstract class IWProtocolException extends Exception {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = -7002466204521265834L;
+
+}

src/main/java/exceptions/IllegalAddrException.java

+package exceptions;
+
+import exceptions.IWProtocolException;
+
+public class IllegalAddrException extends IWProtocolException {
+
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = -2112808760774454967L;
+
+}

src/main/java/exceptions/IllegalCommandException.java

+package exceptions;
+
+public class IllegalCommandException extends IWProtocolException {
+}