Improve DSU joystick cross-platform socket support

Disabled DSU joystick on Emscripten due to lack of UDP socket support. Updated socket initialization to use ioctl with FIONBIO for better compatibility on Unix-like systems. Refactored header includes and comments for clarity and platform correctness. Fixed variable naming in DSU data packet handling and removed unnecessary 'static' from inline functions in header.

Author: danprice142

CMakeLists.txt

@@ -1378,19 +1378,29 @@ if(SDL_JOYSTICK)
 
   # DSU (DualShock UDP) client support
   if(SDL_DSU_JOYSTICK)
-    set(SDL_JOYSTICK_DSU 1)
-    sdl_glob_sources(
-      "${SDL3_SOURCE_DIR}/src/joystick/dsu/*.c"
-      "${SDL3_SOURCE_DIR}/src/joystick/dsu/*.h"
-    )
-    
-    # DSU requires network libraries
-    if(WIN32)
-      list(APPEND SDL3_EXTRA_LIBS ws2_32)
-    elseif(UNIX AND NOT APPLE AND NOT ANDROID AND NOT HAIKU)
-      # Unix systems typically have sockets built-in
-    elseif(HAIKU)
-      list(APPEND SDL3_EXTRA_LIBS network)
+    # Disable DSU for platforms that don't support UDP sockets
+    if(EMSCRIPTEN)
+      message(STATUS "DSU joystick disabled on Emscripten (no UDP socket support)")
+      set(SDL_DSU_JOYSTICK OFF)
+    else()
+      set(SDL_JOYSTICK_DSU 1)
+      sdl_glob_sources(
+        "${SDL3_SOURCE_DIR}/src/joystick/dsu/*.c"
+        "${SDL3_SOURCE_DIR}/src/joystick/dsu/*.h"
+      )
+      
+      # DSU requires network libraries
+      if(WIN32)
+        sdl_link_dependency(dsu LIBS ws2_32)
+      elseif(HAIKU)
+        sdl_link_dependency(dsu LIBS network)
+      elseif(APPLE)
+        # macOS/iOS have sockets built-in, no extra linking needed
+      elseif(ANDROID)
+        # Android has sockets built-in, no extra linking needed
+      elseif(UNIX)
+        # Other Unix systems typically have sockets built-in
+      endif()
     endif()
   endif()
 endif()

src/joystick/dsu/SDL_dsujoystick.c

@@ -61,6 +61,10 @@ typedef int socklen_t;
     #include <fcntl.h>
     #include <unistd.h>
     #include <errno.h>
+    #include <sys/ioctl.h>  /* Required for ioctl on Unix-like systems including Haiku */
+    #ifdef __sun
+        #include <sys/filio.h>  /* FIONBIO on Solaris */
+    #endif
     #define closesocket close
 #endif
 
@@ -121,8 +125,15 @@ dsu_socket_t DSU_CreateSocket(Uint16 port)
 #ifdef _WIN32
     ioctlsocket(sock, FIONBIO, &mode);
 #else
-    flags = fcntl(sock, F_GETFL, 0);
-    fcntl(sock, F_SETFL, flags | O_NONBLOCK);
+    /* Use ioctl with FIONBIO for better compatibility across Unix-like systems */
+    #ifdef FIONBIO
+        int mode_unix = 1;
+        ioctl(sock, FIONBIO, &mode_unix);
+    #else
+        /* Fallback to fcntl if FIONBIO is not available */
+        flags = fcntl(sock, F_GETFL, 0);
+        fcntl(sock, F_SETFL, flags | O_NONBLOCK);
+    #endif
 #endif
 
     /* Bind to client port if specified */
@@ -499,9 +510,9 @@ int SDLCALL DSU_ReceiverThread(void *data)
                     case DSU_MSG_DATA:
                         /* Controller data */
                         if (received >= (int)sizeof(DSU_ControllerData)) {
-                            DSU_ControllerData *data = (DSU_ControllerData *)buffer;
-                            SDL_Log("DSU: Data packet received for slot %d\n", data->info.slot);
-                            DSU_ProcessControllerData(ctx, data);
+                            DSU_ControllerData *packet = (DSU_ControllerData *)buffer;
+                            SDL_Log("DSU: Data packet received for slot %d\n", packet->info.slot);
+                            DSU_ProcessControllerData(ctx, packet);
                         }
                         break;
 

src/joystick/dsu/SDL_dsujoystick_c.h

@@ -122,9 +122,9 @@ extern DSU_Context *s_dsu_ctx;
 extern "C" {
 #endif
 
-static SDL_FORCE_INLINE Uint16 DSU_htons(Uint16 x) { return SDL_Swap16BE(x); }
-static SDL_FORCE_INLINE Uint32 DSU_htonl(Uint32 x) { return SDL_Swap32BE(x); }
-static SDL_FORCE_INLINE Uint32 DSU_ipv4_addr(const char *ip)
+ SDL_FORCE_INLINE Uint16 DSU_htons(Uint16 x) { return SDL_Swap16BE(x); }
+ SDL_FORCE_INLINE Uint32 DSU_htonl(Uint32 x) { return SDL_Swap32BE(x); }
+ SDL_FORCE_INLINE Uint32 DSU_ipv4_addr(const char *ip)
 {
     unsigned int a, b, c, d;
     if (SDL_sscanf(ip, "%u.%u.%u.%u", &a, &b, &c, &d) == 4) {

src/joystick/dsu/SDL_dsujoystick_driver.c

@@ -19,14 +19,21 @@
   3. This notice may not be removed or altered from any source distribution.
 */
 
-/* Include Windows socket headers before SDL to avoid macro conflicts */
+/* Include socket headers before SDL to avoid macro conflicts */
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <winsock2.h>
 #include <ws2tcpip.h>
 #ifdef _MSC_VER
 #pragma comment(lib, "ws2_32.lib")
 #endif
+#else
+/* Unix-like systems including Haiku */
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <errno.h>
 #endif
 
 #include "SDL_internal.h"