Many config-loading memory fixes and group join/leave

Makefile

@@ -6,7 +6,7 @@ all: client server
 
 client:
 	mkdir -p build
-	$(CC) $(CFLAGS) -o build/client client.c util/util.c
+	$(CC) $(CFLAGS) -o build/client client.c
 
 server:
 	mkdir -p build

client.c

@@ -116,6 +116,32 @@ static void input_loop(int server_queue_id, const char *client_id) {
       if (send(server_queue_id, &msg) == -1) {
         perror("msgsnd(/list) failed");
       }
+    } else if (strncmp(buffer, "/join ", 6) == 0) {
+      char *group_name = buffer + 6;
+      if (strlen(group_name) == 0) {
+        printf("Group name cannot be empty\n");
+        continue;
+      }
+
+      msgbuf_t msg = {.mtype = JoinGroup, .sender = ""};
+      strncpy(msg.sender, client_id, COMMAND_LENGTH);
+      strncpy(msg.command, group_name, COMMAND_LENGTH - 1);
+      if (send(server_queue_id, &msg) == -1) {
+        perror("msgsnd(/join) failed");
+      }
+    } else if (strncmp(buffer, "/leave ", 7) == 0) {
+      char *group_name = buffer + 7;
+      if (strlen(group_name) == 0) {
+        printf("Group name cannot be empty\n");
+        continue;
+      }
+
+      msgbuf_t msg = {.mtype = LeaveGroup, .sender = ""};
+      strncpy(msg.sender, client_id, COMMAND_LENGTH);
+      strncpy(msg.command, group_name, COMMAND_LENGTH - 1);
+      if (send(server_queue_id, &msg) == -1) {
+        perror("msgsnd(/leave) failed");
+      }
     } else if (strncmp(buffer, "/mute ", 6) == 0) {
       // handle mute
     } else if (strcmp(buffer, "/quit") == 0 || strcmp(buffer, "/exit") == 0 || strcmp(buffer, "/q") == 0) {
@@ -277,6 +303,26 @@ int main(int argc, char *argv[]) {
         printf("Unhandled signal - code %d.\n", incoming.stype);
       }
       break;
+    case JoinGroup:
+      if (incoming.stype == ACK_ACCEPTED) {
+        printf("Successfully joined the group.\n");
+      } else if (incoming.stype == ERR_USER_NOT_FOUND) {
+        printf("Group does not exist.\n");
+      } else if (incoming.stype == ERR_ALREADY_IN_GROUP) {
+        printf("You are already in this group.\n");
+      } else {
+        printf("Failed to join group: Unknown error (code %d).\n", incoming.stype);
+      }
+      break;
+    case LeaveGroup:
+      if (incoming.stype == ACK_ACCEPTED) {
+        printf("Successfully left the group.\n");
+      } else if (incoming.stype == ERR_USER_NOT_FOUND) {
+        printf("Group does not exist.\n");
+      } else {
+        printf("Failed to leave group: Unknown error (code %d).\n", incoming.stype);
+      }
+      break;
     default:
       printf("Received unknown command of mtype=%ld stype=%d\n", (long)incoming.mtype, incoming.stype);
       break;

commands.h

@@ -10,7 +10,8 @@ typedef enum {
   Logout,
   Hearbeat,
   List,
-  Group,
+  JoinGroup,
+  LeaveGroup,
   Mute,
   Unmute,
   Signal,
@@ -23,6 +24,7 @@ typedef enum {
   ERR_UNKNOWN_COMMAND,
   ERR_NOT_LOGGED_IN,
   ERR_ALREADY_LOGGED_IN,
+  ERR_ALREADY_IN_GROUP,
   ERR_USER_NOT_FOUND,
   ERR_USER_MUTED,
   ERR_INVALID_FORMAT

server.c

@@ -1,4 +1,3 @@
-#include "bits/types/struct_timeval.h"
 #include "sys/ipc.h"
 #include "sys/shm.h"
 #include <fcntl.h>
@@ -98,8 +97,9 @@ int main(int argc, char **argv) {
 
   for (int i = 0; i < group_count; i++) {
     strncpy(groups[i].name, config.groups[i].name, COMMAND_LENGTH - 2);
-    groups[i].client_count = config.groups[i].member_count;
+    // Allocate space for all clients to be able to join, not just initial members
-    groups[i].members = malloc(sizeof(Client_t *) * config.groups[i].member_count);
+    groups[i].client_count = client_count;
+    groups[i].members = calloc(client_count, sizeof(Client_t *));
     for (int j = 0; j < config.groups[i].member_count; j++) {
       // Find the client with the given id
       for (int k = 0; k < client_count; k++) {
@@ -236,12 +236,14 @@ int main(int argc, char **argv) {
       // Now we have to decode if we are to forward this message to a user or a
       // group. A group is indicated by a #  at the start of the command
       char target_type = msgbuf.command[0];
-      Client_t **recipients = malloc(sizeof(Client_t *) * client_count - 1); // We won't send to ourselves so one less
+      Client_t **recipients = malloc(sizeof(Client_t *) * (client_count - 1)); // We won't send to ourselves so one less
 
       if (target_type != '#') {
+        recipients[0] = NULL; // Initialize to NULL in case no match is found
         for (int i = 0; i < client_count; i++) {
           if (strncmp(clients[i].nickname, msgbuf.command, COMMAND_LENGTH) == 0) {
             recipients[0] = &clients[i];
+            recipients[1] = NULL; // Mark end of list
             break;
           }
         }
@@ -263,6 +265,7 @@ int main(int argc, char **argv) {
               .stype = ERR_USER_NOT_FOUND,
           };
           send(client->queue_id, &response);
+          free(recipients);
           continue;
         }
 
@@ -280,6 +283,18 @@ int main(int argc, char **argv) {
         }
       }
 
+      // Check if we found any recipients
+      if (recipients[0] == NULL) {
+        printf("Target user %s not found\n", msgbuf.command);
+        msgbuf_t response = {
+            .mtype = Signal,
+            .stype = ERR_USER_NOT_FOUND,
+        };
+        send(client->queue_id, &response);
+        free(recipients);
+        continue;
+      }
+
       // Now forward the message to all recipients
       for (int i = 0; i < client_count - 1; i++) {
         Client_t *target_client = recipients[i];
@@ -329,6 +344,7 @@ int main(int argc, char **argv) {
 
         printf("Forwarding message: %s\n", msgbuf.message);
       }
+      free(recipients);
       break;
     }
     case Logout: {
@@ -381,7 +397,7 @@ int main(int argc, char **argv) {
         for (int i = 0; i < group_count; i++) {
           bool isMember = false;
           for (int j = 0; j < groups[i].client_count; j++) {
-            if (strncmp(groups[i].members[j]->id, client->id, COMMAND_LENGTH) == 0) {
+            if (groups[i].members[j] != NULL && strncmp(groups[i].members[j]->id, client->id, COMMAND_LENGTH) == 0) {
               isMember = true;
               break;
             }
@@ -487,7 +503,152 @@ int main(int argc, char **argv) {
       client->saved_message_count = 0;
       break;
     }
+    // Command field contains the group name
+    case JoinGroup: {
+      Client_t *client = NULL;
+      for (int i = 0; i < client_count; i++) {
+        if (strncmp(clients[i].id, msgbuf.sender, COMMAND_LENGTH) == 0) {
+          client = &clients[i];
+          break;
+        }
+      }
+
+      if (client == NULL || !client->logged_in)
+        continue;
+
+      printf("Request to join for group: %s\n", msgbuf.command);
+
+      Group_t *target_group = NULL;
+      for (int i = 0; i < group_count; i++) {
+        printf("Comparing group[%d].name='%s' (len=%zu) with command='%s' (len=%zu)\n", i, groups[i].name,
+               strlen(groups[i].name), msgbuf.command, strlen(msgbuf.command));
+        if (strcmp(groups[i].name, msgbuf.command) == 0) {
+          target_group = &groups[i];
+          printf("Group match found!\n");
+          break;
+        }
+      }
+
+      // Target group not found
+      if (target_group == NULL) {
+        printf("Target group %s not found\n", msgbuf.command);
+        msgbuf_t response = {
+            .mtype = JoinGroup,
+            .stype = ERR_USER_NOT_FOUND,
+        };
+        send(client->queue_id, &response);
+        continue;
+      }
+
+      // Check if user is already in the group
+      bool is_in_group = false;
+      printf("Group '%s' has %d member slots\n", target_group->name, target_group->client_count);
+      for (int i = 0; i < target_group->client_count; i++) {
+        if (target_group->members[i] != NULL) {
+          printf("  Slot %d: %s\n", i, target_group->members[i]->id);
+          if (strncmp(client->id, target_group->members[i]->id, COMMAND_LENGTH) == 0) {
+            is_in_group = true;
+            break;
+          }
+        } else {
+          printf("  Slot %d: NULL\n", i);
+        }
+      }
+
+      if (is_in_group) {
+        msgbuf_t response = {.mtype = JoinGroup, .stype = ERR_ALREADY_IN_GROUP};
+        send(client->queue_id, &response);
+        continue;
+      }
+
+      // Only after we know that the user isn't in the group, by going over the whole list, we can add them
+      // We could do that in the loop above, if there was a guarantee of there not being gaps in the array
+      // This should be a linked list... well it's too late now...
+      bool added = false;
+      for (int i = 0; i < target_group->client_count; i++) {
+        if (target_group->members[i] == NULL) {
+          target_group->members[i] = client;
+          msgbuf_t response = {
+              .mtype = JoinGroup,
+              .stype = ACK_ACCEPTED,
+          };
+          send(client->queue_id, &response);
+          printf("Client %s joined group %s\n", client->id, target_group->name);
+          added = true;
+          break;
+        }
+      }
+
+      if (!added) {
+        msgbuf_t response = {
+            .mtype = JoinGroup,
+            .stype = ERR_USER_NOT_FOUND, // Reusing errors, why not
+        };
+        send(client->queue_id, &response);
+      }
+      break;
+    }
+    case LeaveGroup: {
+      Client_t *client = NULL;
+      for (int i = 0; i < client_count; i++) {
+        if (strncmp(clients[i].id, msgbuf.sender, COMMAND_LENGTH) == 0) {
+          client = &clients[i];
+          break;
+        }
+      }
+
+      if (client == NULL || !client->logged_in)
+        continue;
+
+      printf("Request to leave group: %s\n", msgbuf.command);
+
+      Group_t *target_group = NULL;
+      for (int i = 0; i < group_count; i++) {
+        printf("Comparing group[%d].name='%s' with command='%s'\n", i, groups[i].name, msgbuf.command);
+        if (strcmp(groups[i].name, msgbuf.command) == 0) {
+          target_group = &groups[i];
+          break;
+        }
+      }
+
+      // Target group not found
+      if (target_group == NULL) {
+        printf("Target group %s not found\n", msgbuf.command);
+        msgbuf_t response = {
+            .mtype = LeaveGroup,
+            .stype = ERR_USER_NOT_FOUND,
+        };
+        send(client->queue_id, &response);
+        continue;
+      }
+
+      bool was_in_group = false;
+      for (int i = 0; i < target_group->client_count; i++) {
+        if (target_group->members[i] != NULL &&
+            strncmp(client->id, target_group->members[i]->id, COMMAND_LENGTH) == 0) {
+          target_group->members[i] = NULL;
+          msgbuf_t response = {
+              .mtype = LeaveGroup,
+              .stype = ACK_ACCEPTED,
+          };
+          send(client->queue_id, &response);
+          printf("Client %s left group %s\n", client->id, target_group->name);
+          was_in_group = true;
+          break;
+        }
+      }
+
+      if (!was_in_group) {
+        msgbuf_t response = {
+            .mtype = LeaveGroup,
+            .stype = ERR_USER_NOT_FOUND, // Could add ERR_NOT_IN_GROUP error code
+        };
+        send(client->queue_id, &response);
+      }
+      break;
+    }
     case Mute:
+
     case Unmute:
       break;
     case Signal: