Initial solution

chatnode.properties

@@ -1,3 +1,3 @@
 ip = 127.0.0.1
 port = 51966
-username = Person4
+username = Person3

src/chat_node.c

@@ -4,6 +4,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <sys/socket.h>
+#include <unistd.h>
 
 #include "debug.h"
 #include "main.h"
@@ -66,6 +67,10 @@ inline void addNode(Node **nodeList, Node *node) {
     while (curNode->nextNode != NULL) {
         // Move to next node
         curNode = curNode->nextNode;
+
+        // If node is already in the node list, do nothing
+        if (curNode == node)
+            return;
     }
 
     debug("curNode: %p", curNode);
@@ -125,6 +130,10 @@ inline void removeNode(Node **nodeList, Node *node) {
     printf("%s has left the chat room.\n", curNode->username);
 
     // Clean up old node
+    curNode->connected = false;
+    free(curNode->ip);
+    free(curNode->username);
+    close(curNode->sock);
     free(curNode);
 
     printNodeList(*nodeList);

src/main.c

@@ -82,8 +82,19 @@ void *send_handler(void *nodeListRaw) {
 
             debug("Command result action: %d", cmdResult.action);
 
-            if (cmdResult.action == ACTION_LEAVE || cmdResult.action == ACTION_SHUTDOWN)
+            if (cmdResult.action == ACTION_LEAVE) {
+                // Disconnect from all other nodes
+                Node *curNode = nodeList->initialNode ? nodeList->nextNode->nextNode : nodeList->nextNode;
+                while (curNode != NULL) {
+                    curNode->connected = false;
+                    close(curNode->sock);
+                    curNode = curNode->nextNode;
+                }
+                printNodeList(nodeList);
+            }
+            else if (cmdResult.action == ACTION_SHUTDOWN) {
                 break;
+            }
         }
     }
 
@@ -94,26 +105,43 @@ void *send_handler(void *nodeListRaw) {
 
 void *receive_handler(void *recHandlerDataRaw) {
     ReceiveHandlerData *recHandlerData = (ReceiveHandlerData *) recHandlerDataRaw;
+    Node *nodeList = recHandlerData->nodeList;
+    Node *node = recHandlerData->curNode;
 
     printNodeList(recHandlerData->nodeList);
 
     while (true) {
         Message message;
 
-        if (!recHandlerData->curNode->connected) {
+        if (!node->connected) {
+            debug("Node %p is not connected anymore!", node);
             // If no longer connected, remove the node and exit thread
-            debug("Removing node!");
-            removeNode(&recHandlerData->nodeList, recHandlerData->curNode);
+
+            // Don't remove head of node list
+            if (node != nodeList) {
+                // Don't remove 2nd node if self node is not an initial node
+                if (nodeList->initialNode || node != nodeList->nextNode) {
+                    debug("Removing node %p!", node);
+                    removeNode(&nodeList, node);
+                    break;
+                }
+            }
+
+            // For the node describing the original node to connect to, re-initialize the node for rejoining
+            node->sock = socket(AF_INET, SOCK_STREAM, 0);
+
             break;
         }
 
-        if (receiveMessage(recHandlerData->nodeList, recHandlerData->curNode, &message)) {
-            if (!handleClient(recHandlerData->nodeList, recHandlerData->curNode, message))
-                break;
+        if (receiveMessage(nodeList, node, &message)) {
+            if (!handleClient(nodeList, node, message)) {
+                exit(EXIT_SUCCESS); // Quick and dirty
+            }
         }
     }
 
     free(recHandlerData);
+    debug("Receive handler for node %p has shut down.", node);
 
     return NULL;
 }

src/message.c

@@ -228,6 +228,8 @@ inline Message deserializeMessage(Node *nodeList, uint8_t *rawMessage, size_t ra
             message.note = malloc(strlen((char *) rawMessage + 1)) + 1;
             strcpy(message.note, (char *) rawMessage + 1);
             break;
+        case MSG_LEAVE:
+            break;
         default:
             debug("Unknown message type recieved!");
             break;

src/message.h

@@ -20,6 +20,8 @@
  * 5: Flag 3
  * 6: Flag 4
  * 7: Flag 5
+ * 
+ * For use with getBit and setBit, the order is flipped!
  */
 typedef uint8_t MessageHeader;
 

src/receiver_handler.c

@@ -68,11 +68,15 @@ inline bool handleClient(Node *nodeList, Node *node, Message message) {
             break;
         case MSG_LEAVE:
             debug("Leave received!");
-            // removeNode(&nodeList, node); // TODO: Not needed?
+
             if (getBit(message.header, 0)) {
-                printf("The chat room is shutting down. Goodbye.");
+                printf("The chat room is shutting down. Goodbye.\n");
                 return false;
             }
+
+            // Disconnect from node (mark for removal); this prevents any more messages from being received
+            node->connected = false;
+
             break;
     }
 
@@ -85,18 +89,25 @@ inline bool receiveMessage(Node *nodeList, Node *node, Message *messageOut) {
     ssize_t rawMessageSize = recv(node->sock, &rawMessage, sizeof(rawMessage), 0);
 
     if (rawMessageSize == -1) {
+        if (errno == EBADF) {
+            goto SOCKET_CLOSED;
+        }
+
         debug("Error reading message?");
         return false;
     }
     else if (rawMessageSize == 0) {
-        debug("Socket closed for node %p (%s)!", node, node->username);
-        node->connected = false;
-        return false;
+        goto SOCKET_CLOSED;
     }
 
     debug("received message!");
 
     // Create message from received data
     *messageOut = deserializeMessage(nodeList, rawMessage, rawMessageSize);
     return true;
+
+SOCKET_CLOSED:
+    debug("Socket closed for node %p (%s)!", node, node->username);
+    node->connected = false;
+    return false;
 }

src/sender_handler.c

@@ -87,6 +87,7 @@ inline bool connectToNode(Node *nodeList, Node *node, bool newJoin, Message *joi
     connectSocket(nodeList, node);
 
     if (node->connected) {
+        addNode(&nodeList, node);
         debug("connectToNode(): new join: %d", newJoin);
         *joinMessageOut = createJoinMessage(nodeList->username, nodeList->port, newJoin);
         return true;
@@ -114,7 +115,7 @@ inline bool handleCommand(Node *nodeList, char *input, CommandResult *cmdResultO
         }
         else {
             if (connectToNode(nodeList, nodeList->nextNode, true, &cmdResultOut->message))
-                printf("You successfully joined %s's chat room.\n", nodeList->nextNode->username);
+                printf("You successfully the chat room.\n");
             else
                 return false;
         }