Closing active wireless sessions by updating broadcast data

README.md

@@ -196,7 +196,7 @@ Name | Return type | Description
 `isActive()` | **bool** | Returns whether the library is active or not.
 `activate()` | **bool** | Activates the library. When an adapter is connected, it changes the state to `AUTHENTICATED`. It can also be used to disconnect or reset the adapter.
 `deactivate()` | **bool** | Puts the adapter into a low consumption mode and then deactivates the library. It returns a boolean indicating whether the transition to low consumption mode was successful.
-`serve([gameName], [userName], [gameId])` | **bool** | Starts broadcasting a server and changes the state to `SERVING`. You can, optionally, provide a `gameName` (max `14` characters), a `userName` (max `8` characters), and a `gameId` *(0 ~ 0x7FFF)* that games will be able to read.
+`serve([gameName], [userName], [gameId], [isUpdate])` | **bool** | Starts broadcasting a server and changes the state to `SERVING`. You can, optionally, provide a `gameName` (max `14` characters), a `userName` (max `8` characters), and a `gameId` *(0 ~ 0x7FFF)* that games will be able to read. If `isUpdate` is true, this method only updates the broadcast data.
 `getServers(servers, [onWait])` | **bool** | Fills the `servers` array with all the currently broadcasting servers. This action takes 1 second to complete, but you can optionally provide an `onWait()` function which will be invoked each time VBlank starts.
 `getServersAsyncStart()` | **bool** | Starts looking for broadcasting servers and changes the state to `SEARCHING`. After this, call `getServersAsyncEnd(...)` 1 second later.
 `getServersAsyncEnd(servers)` | **bool** | Fills the `servers` array with all the currently broadcasting servers. Changes the state to `AUTHENTICATED` again.

docs/wireless_adapter.md

@@ -249,6 +249,8 @@ Both Pokemon games and the multiboot ROM that the adapter sends when no cartridg
 
 🆔 The **Game ID** is what games use to avoid listing servers from another game. This is done on the software layer (GBA), the adapter does not enforce this in any way, nor does gba-link-connection.
 
+🔥 This command can be called even when the server has already started with `StartHost`, and the adapter will update the broadcast data. Some games include metadata in the game/user name fields, such as the player's gender or a busy flag.
+
 #### StartHost - `0x19`
 
 *   Send length: 0, response length: 0

lib/LinkUniversal.hpp

@@ -47,6 +47,8 @@
 #define LINK_UNIVERSAL_DISCONNECTED LINK_CABLE_DISCONNECTED
 #define LINK_UNIVERSAL_NO_DATA LINK_CABLE_NO_DATA
 #define LINK_UNIVERSAL_MAX_ROOM_NUMBER 32000
+#define LINK_UNIVERSAL_FULL_ROOM_NUMBER 32001
+#define LINK_UNIVERSAL_FULL_ROOM_NUMBER_STR "32001"
 #define LINK_UNIVERSAL_INIT_WAIT_FRAMES 10
 #define LINK_UNIVERSAL_SWITCH_WAIT_FRAMES 25
 #define LINK_UNIVERSAL_SWITCH_WAIT_FRAMES_RANDOM 10
@@ -208,6 +210,15 @@ class LinkUniversal {
           }
 
           receiveWirelessMessages();
+
+          if (!linkWireless->_hasActiveAsyncCommand() &&
+              linkWireless->playerCount() == linkWireless->config.maxPlayers &&
+              !didCloseWirelessRoom) {
+            linkWireless->serve(config.gameName,
+                                LINK_UNIVERSAL_FULL_ROOM_NUMBER_STR,
+                                LINK_WIRELESS_MAX_GAME_ID, true);
+            didCloseWirelessRoom = true;
+          }
         }
 
         break;
@@ -305,6 +316,7 @@ class LinkUniversal {
   u32 switchWait = 0;
   u32 subWaitCount = 0;
   u32 serveWait = 0;
+  bool didCloseWirelessRoom = false;
   volatile bool isEnabled = false;
 
   void receiveCableMessages() {
@@ -381,12 +393,13 @@ class LinkUniversal {
       if (server.id == LINK_WIRELESS_END)
         break;
 
-      u32 randomNumber = std::stoi(server.userName);
-
-      if (server.gameName == config.gameName &&
-          randomNumber > maxRandomNumber) {
-        maxRandomNumber = randomNumber;
-        serverIndex = i;
+      if (server.gameName == config.gameName) {
+        u32 randomNumber = safeStoi(server.userName);
+        if (randomNumber > maxRandomNumber &&
+            randomNumber < LINK_UNIVERSAL_FULL_ROOM_NUMBER) {
+          maxRandomNumber = randomNumber;
+          serverIndex = i;
+        }
       }
     }
 
@@ -478,6 +491,19 @@ class LinkUniversal {
     serveWait = 0;
     for (u32 i = 0; i < LINK_UNIVERSAL_MAX_PLAYERS; i++)
       incomingMessages[i].clear();
+    didCloseWirelessRoom = false;
+  }
+
+  u32 safeStoi(const std::string& str) {
+    uint32_t num = 0;
+
+    for (char ch : str) {
+      if (ch < '0' || ch > '9')
+        return 0;
+      num = num * 10 + (ch - '0');
+    }
+
+    return num;
   }
 };
 

lib/LinkWireless.hpp

@@ -251,9 +251,10 @@ class LinkWireless {
 
   bool serve(std::string gameName = "",
              std::string userName = "",
-             u16 gameId = LINK_WIRELESS_MAX_GAME_ID) {
+             u16 gameId = LINK_WIRELESS_MAX_GAME_ID,
+             bool isUpdate = false) {
     LINK_WIRELESS_RESET_IF_NEEDED
-    if (state != AUTHENTICATED) {
+    if (state != AUTHENTICATED && (!isUpdate || state != SERVING)) {
       lastError = WRONG_STATE;
       return false;
     }
@@ -281,8 +282,13 @@ class LinkWireless {
                      buildU16(userName[1], userName[0])));
     addData(buildU32(buildU16(userName[7], userName[6]),
                      buildU16(userName[5], userName[4])));
-    bool success = sendCommand(LINK_WIRELESS_COMMAND_BROADCAST, true).success &&
-                   sendCommand(LINK_WIRELESS_COMMAND_START_HOST).success;
+
+    bool success = sendCommand(LINK_WIRELESS_COMMAND_BROADCAST, true).success;
+
+    if (!isUpdate) {
+      success =
+          success && sendCommand(LINK_WIRELESS_COMMAND_START_HOST).success;
+    }
 
     if (!success) {
       reset();
@@ -513,6 +519,7 @@ class LinkWireless {
     delete linkGPIO;
   }
 
+  bool _hasActiveAsyncCommand() { return asyncCommand.isActive; }
   bool _canSend() { return !sessionState.outgoingMessages.isFull(); }
   u32 _getPendingCount() { return sessionState.outgoingMessages.size(); }
   u32 _lastPacketId() { return sessionState.lastPacketId; }