diff --git a/sequence.jpg b/internetworking_ws23.zip
similarity index 52%
rename from sequence.jpg
rename to internetworking_ws23.zip
index f8af87353d2ac0fbb00998f45d8b6e89382cfcd4..01f158f5eb24e0e81a0330b0d7cd80a898c76c65 100644
Binary files a/sequence.jpg and b/internetworking_ws23.zip differ
diff --git a/src/main/java/cp/StatusCommandMessage.java b/src/main/java/cp/CPCommandMessage.java
similarity index 58%
rename from src/main/java/cp/StatusCommandMessage.java
rename to src/main/java/cp/CPCommandMessage.java
index f5bf87ff14681cfcb94d3a5880142e5a32470124..df0b58935ffe05788769cfab77e2a463166a2e23 100644
--- a/src/main/java/cp/StatusCommandMessage.java
+++ b/src/main/java/cp/CPCommandMessage.java
@@ -1,64 +1,56 @@
package cp;
-import core.Msg;
+import exceptions.IllegalCommandException;
import java.util.zip.CRC32;
import java.util.zip.Checksum;
-public class StatusCommandMessage extends CPMsg{
-
- private String cookie;
- private String command;
- private String message;
- private String data;
+public class CPCommandMessage extends CPMsg{
private static int messageIdCount = 0; //tracks the IDS
private int currentMessageId;
private static final int MAX_ID = 65535; //maximum message id according to the protocol specification.
protected static final String HEADER = "command";
- public StatusCommandMessage() {}
+ public CPCommandMessage() {}
- public StatusCommandMessage create(String cookie, String command, String message){
+ public CPCommandMessage create(String cookie, String command, String message){
+ //maybe throw an exception if the ID's run out?
if(messageIdCount < MAX_ID){
currentMessageId = messageIdCount;
messageIdCount++;
}
- this.cookie = cookie;
- this.command = command;
- this.message = message;
-
StringBuilder str = new StringBuilder();
- str.append("cp").append(' ');
str.append(HEADER).append(' ');
str.append(currentMessageId).append(' ');
str.append(cookie).append(' ');
str.append(command).append(' ');
- if(message != null && !message.isEmpty())str.append(message).append(' '); //message is optional by protocol specification
+ if(message != null && !message.isEmpty())str.append(message).append(' '); //message is optional according to protocol specification
+
+ //calls the create method of CPMsg so the header gets added
+ super.create(str.toString());
this.data = str.toString(); //builds the Frame
str.append(calcCRC(this.data)); //calculates the crc and adds it to the Frame
- this.data = str.toString();
+ this.data = str.toString(); //builds the Frame again, but with the attached checksum
+
return this;
}
- public String getData(){
- return this.data;
+ //returns the unique id of the message
+ public int getMessageId(){
+ return currentMessageId;
}
- @Override
- protected Msg parse(String sentence){
-
- String[] split = sentence.split(" ");
-
- return null;
+ public static int getMaxMessageId() {
+ return MAX_ID;
}
- private long calcCRC(String data) {
+ public static long calcCRC(String data) {
Checksum tmp = new CRC32();
tmp.update(data.getBytes());
return tmp.getValue();
diff --git a/src/main/java/cp/CPCommandResponseMessage.java b/src/main/java/cp/CPCommandResponseMessage.java
new file mode 100644
index 0000000000000000000000000000000000000000..036db6c60e4dc17f15b1efbfada848b0d98bcee6
--- /dev/null
+++ b/src/main/java/cp/CPCommandResponseMessage.java
@@ -0,0 +1,109 @@
+package cp;
+
+import core.Msg;
+import exceptions.IWProtocolException;
+import exceptions.IllegalMsgException;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class CPCommandResponseMessage extends CPMsg{
+
+ private int currentMessageId;
+ protected static final String COMRES_HEADER = "comres";
+
+ CPCommandResponseMessage(){}
+
+ public int getMessageId(){
+ return currentMessageId;
+ }
+
+ @Override
+ protected Msg parse(String sentence) throws IWProtocolException {
+
+ //dismantelts the received frame into its components
+ String[] fields = sentence.split(" ");
+ //the "actual" Message might have whitespaces in it self. so we need to put it back together later with the help of the messageLength field
+ StringBuilder reconstructedMessage = new StringBuilder();
+ int messageLength;
+
+ //first check, to see if the received frame is valid.
+ if(!fields[0].equals("cp") || !fields[1].equals(COMRES_HEADER)){
+ throw new IllegalMsgException();
+ }
+
+ try {
+ this.currentMessageId = Integer.parseInt(fields[2]);
+ //throws NumberFormatException, if the id couldnt get parsed for whatever reason
+
+ //throws exception if the id from the received message is too large or negative, wich it cant be according to protocol specification
+ if(currentMessageId > CPCommandMessage.getMaxMessageId() || currentMessageId < 0){
+ throw new IllegalMsgException();
+ }
+ }catch (NumberFormatException e){
+ throw new IllegalMsgException();
+ }
+
+ //sucess ok or error
+ if(!fields[3].equals("ok") && !fields[3].equals("error")){
+ throw new IllegalMsgException();
+ }
+
+ //get the length of the actual message. Again, might throw an exception if the length value is not a number for example
+ try {
+ messageLength = Integer.parseInt(fields[4]);
+ }catch (NumberFormatException e){
+ throw new IllegalMsgException();
+ }
+
+
+ /* im not proud of the following code, but it sure works :) */
+
+ //reconstructes message
+ int fieldIndex = 5;
+ int sumLen = 0;
+
+ //calculating the actual length of the message
+ for (int i = 5; i < fields.length - 1; i++) {
+
+ sumLen += fields[i].length(); //count sum of each real message field
+ sumLen++; //count whitespace between
+ }
+ sumLen--; //dont count the whitespace from the last loop iteration
+
+ //if the legth field is different from the actual message length
+ if (sumLen > 0) {
+ if(sumLen != messageLength){
+ throw new IllegalMsgException();
+ }
+ }
+
+ /* Doesnt work yet :)
+
+ //calculating and comparing crc
+ int tmpCRC;
+ int CRCLen = fields[fields.length - 1].length();
+
+
+ //get the crc
+ try {
+ tmpCRC = Integer.parseInt(fields[fields.length-1]);
+ }catch (NumberFormatException e){
+ throw new IllegalMsgException();
+ }
+
+ String calcCRC = sentence.substring(0,CRCLen);
+
+ if(tmpCRC != CPCommandMessage.calcCRC(calcCRC)){
+ throw new IllegalMsgException();
+ }*/
+
+ //sets the received message as the data, so the client can print it on the console
+ this.data = reconstructedMessage.toString();
+
+
+
+ return this;
+ }
+}
diff --git a/src/main/java/cp/CPProtocol.java b/src/main/java/cp/CPProtocol.java
index efa18e97adf33a569d72d62bde9c5d3c0f021c60..4a1c619abc0ded5cfef562b060503382603738e2 100644
--- a/src/main/java/cp/CPProtocol.java
+++ b/src/main/java/cp/CPProtocol.java
@@ -48,8 +48,11 @@ public class CPProtocol extends Protocol {
if(cookie != null) {
//1.2: 1 b
- StatusCommandMessage cmdMsg = new StatusCommandMessage();
- cmdMsg.create(cookie, s, "");
+ CPCommandMessage cmdMsg = new CPCommandMessage();
+ cmdMsg.create(cookie, s, "status");
+
+ //remembers the id of the current message, so when it's time to receive wel can check if the id's are the same
+ this.id = cmdMsg.getMessageId();
//1.2: 1 c
PhyProto.send(cmdMsg.getData(), this.PhyConfig);
@@ -64,26 +67,30 @@ public class CPProtocol extends Protocol {
boolean receving = true;
while(receving){
- in = this.PhyProto.receive(CP_TIMEOUT);
//1.2: 2 b
- CPMsg cpmsg = new StatusCommandMessage();
- cpmsg.create(in.getData());
-
- //todo: comparing ids (2. c)
+ CPMsg cpmsg = new CPCommandResponseMessage();
try {
+ in = this.PhyProto.receive(CP_TIMEOUT);
+
//1.2: 2 b
in = cpmsg.parse(in.getData());
+
} catch (Exception e) {
+ System.out.println(e.getMessage());
continue;
//Discard Message
}
-
receving = false;
}
+ //compare the id from the received message and the earlier sent message
+ if(((CPCommandResponseMessage) in).getMessageId() != this.id){
+ return null;
+ }
+
return in;
}
diff --git a/src/main/java/cp/StatusCommandResponseMessage.java b/src/main/java/cp/StatusCommandResponseMessage.java
deleted file mode 100644
index f70dfdf238b6e74f24decab2e1bf272a6dc7438d..0000000000000000000000000000000000000000
--- a/src/main/java/cp/StatusCommandResponseMessage.java
+++ /dev/null
@@ -1,4 +0,0 @@
-package cp;
-
-public class StatusCommandResponseMessage extends CPMsg{
-}