Add platform support for the 3DS

Prevent wildcard port binding on the 3DS
Add 3DS threading logic
Add 3DS socket logic
Bump the connection timeout to 60s for the 3DS

src/ControlStream.c

@@ -1646,7 +1646,12 @@ int startControlStream(void) {
         LC_ASSERT(ControlPortNumber != 0);
 
         enet_address_set_address(&localAddress, (struct sockaddr *)&LocalAddr, AddrLen);
+#ifdef __3DS__
+        // binding to wildcard port is broken on the 3DS, so we need to define a port manually
+        enet_address_set_port(&localAddress, htons(n3ds_udp_port++));
+#else
         enet_address_set_port(&localAddress, 0); // Wildcard port
+#endif
 
         enet_address_set_address(&remoteAddress, (struct sockaddr *)&RemoteAddr, AddrLen);
         enet_address_set_port(&remoteAddress, ControlPortNumber);
@@ -1712,8 +1717,14 @@ int startControlStream(void) {
         // Ensure the connect verify ACK is sent immediately
         enet_host_flush(client);
 
+#ifdef __3DS__
+        // Set the peer timeout to 1 minute and limit backoff to 2x RTT
+        // The 3DS can take a bit longer to set up when starting fresh
+        enet_peer_timeout(peer, 2, 60000, 60000);
+#else
         // Set the peer timeout to 10 seconds and limit backoff to 2x RTT
         enet_peer_timeout(peer, 2, 10000, 10000);
+#endif
     }
     else {
         // NB: Do NOT use ControlPortNumber here. 47995 is correct for these old versions.

src/Platform.c

@@ -93,7 +93,7 @@ void* ThreadProc(void* context) {
     free(ctx);
 #endif
 
-#if defined(LC_WINDOWS) || defined(__vita__) || defined(__WIIU__)
+#if defined(LC_WINDOWS) || defined(__vita__) || defined(__WIIU__) || defined(__3DS__)
     return 0;
 #else
     return NULL;
@@ -105,6 +105,9 @@ void PltSleepMs(int ms) {
     SleepEx(ms, FALSE);
 #elif defined(__vita__)
     sceKernelDelayThread(ms * 1000);
+#elif defined(__3DS__)
+    s64 nsecs = ms * 1000000;
+    svcSleepThread(nsecs);
 #else
     useconds_t usecs = ms * 1000;
     usleep(usecs);
@@ -129,6 +132,8 @@ int PltCreateMutex(PLT_MUTEX* mutex) {
     }
 #elif defined(__WIIU__)
     OSFastMutex_Init(mutex, "");
+#elif defined(__3DS__)
+    LightLock_Init(mutex);
 #else
     int err = pthread_mutex_init(mutex, NULL);
     if (err != 0) {
@@ -145,7 +150,7 @@ void PltDeleteMutex(PLT_MUTEX* mutex) {
     // No-op to destroy a SRWLOCK
 #elif defined(__vita__)
     sceKernelDeleteMutex(*mutex);
-#elif defined(__WIIU__)
+#elif defined(__WIIU__) || defined(__3DS__)
 
 #else
     pthread_mutex_destroy(mutex);
@@ -159,6 +164,8 @@ void PltLockMutex(PLT_MUTEX* mutex) {
     sceKernelLockMutex(*mutex, 1, NULL);
 #elif defined(__WIIU__)
     OSFastMutex_Lock(mutex);
+#elif defined(__3DS__)
+    LightLock_Lock(mutex);
 #else
     pthread_mutex_lock(mutex);
 #endif
@@ -171,6 +178,8 @@ void PltUnlockMutex(PLT_MUTEX* mutex) {
     sceKernelUnlockMutex(*mutex, 1);
 #elif defined(__WIIU__)
     OSFastMutex_Unlock(mutex);
+#elif defined(__3DS__)
+    LightLock_Unlock(mutex);
 #else
     pthread_mutex_unlock(mutex);
 #endif
@@ -187,6 +196,9 @@ void PltJoinThread(PLT_THREAD* thread) {
         free(thread->context);
 #elif defined(__WIIU__)
     OSJoinThread(&thread->thread, NULL);
+#elif defined(__3DS__)
+    threadJoin(thread->thread, U64_MAX);
+    threadFree(thread->thread);
 #else
     pthread_join(thread->thread, NULL);
 #endif
@@ -265,6 +277,22 @@ int PltCreateThread(const char* name, ThreadEntry entry, void* context, PLT_THRE
 
     OSSetThreadDeallocator(&thread->thread, thread_deallocator);
     OSResumeThread(&thread->thread);
+#elif defined(__3DS__)
+    {
+        s32 priority = 0x30;
+        size_t stack_size = 1024 * 1024;
+        svcGetThreadPriority(&priority, CUR_THREAD_HANDLE);
+        thread->thread = threadCreate(ThreadProc,
+                                    ctx,
+                                    stack_size,
+                                    priority,
+                                    -1,
+                                    false);
+        if (thread->thread == NULL) {
+            free(ctx);
+            return -1;
+        }
+    }
 #else
     {
         int err = pthread_create(&thread->thread, NULL, ThreadProc, ctx);
@@ -351,6 +379,8 @@ int PltCreateConditionVariable(PLT_COND* cond, PLT_MUTEX* mutex) {
     }
 #elif defined(__WIIU__)
     OSFastCond_Init(cond, "");
+#elif defined(__3DS__)
+    CondVar_Init(cond);
 #else
     pthread_cond_init(cond, NULL);
 #endif
@@ -364,6 +394,8 @@ void PltDeleteConditionVariable(PLT_COND* cond) {
     sceKernelDeleteCond(*cond);
 #elif defined(__WIIU__)
     // No-op to delete an OSFastCondition
+#elif defined(__3DS__)
+    // No-op to delete CondVar
 #else
     pthread_cond_destroy(cond);
 #endif
@@ -376,6 +408,8 @@ void PltSignalConditionVariable(PLT_COND* cond) {
     sceKernelSignalCond(*cond);
 #elif defined(__WIIU__)
     OSFastCond_Signal(cond);
+#elif defined(__3DS__)
+    CondVar_Signal(cond);
 #else
     pthread_cond_signal(cond);
 #endif
@@ -388,6 +422,8 @@ void PltWaitForConditionVariable(PLT_COND* cond, PLT_MUTEX* mutex) {
     sceKernelWaitCond(*cond, NULL);
 #elif defined(__WIIU__)
     OSFastCond_Wait(cond, mutex);
+#elif defined(__3DS__)
+    CondVar_Wait(cond, mutex);
 #else
     pthread_cond_wait(cond, mutex);
 #endif
@@ -460,7 +496,7 @@ int initializePlatform(void) {
 
     enterLowLatencyMode();
 
-	return 0;
+    return 0;
 }
 
 void cleanupPlatform(void) {

src/Platform.h

@@ -32,6 +32,9 @@
 #include <coreinit/fastmutex.h>
 #include <coreinit/fastcondition.h>
 #include <fcntl.h>
+#elif defined(__3DS__)
+#include <3ds.h>
+#include <fcntl.h>
 #else
 #include <unistd.h>
 #include <pthread.h>

src/PlatformSockets.c

@@ -35,6 +35,10 @@ DWORD (WINAPI *pfnWlanSetInterface)(HANDLE hClientHandle, CONST GUID *pInterface
 
 #endif
 
+#ifdef __3DS__
+in_port_t n3ds_udp_port = 47998;
+#endif
+
 void addrToUrlSafeString(struct sockaddr_storage* addr, char* string, size_t stringLength)
 {
     char addrstr[URLSAFESTRING_LEN];
@@ -74,8 +78,8 @@ int setNonFatalRecvTimeoutMs(SOCKET s, int timeoutMs) {
     // losing some data in a very rare case is fine, especially because we get to
     // halve the number of syscalls per packet by avoiding select().
     return setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, (char*)&timeoutMs, sizeof(timeoutMs));
-#elif defined(__WIIU__)
-    // timeouts aren't supported on Wii U
+#elif defined(__WIIU__) || defined(__3DS__)
+    // timeouts aren't supported on Wii U or 3DS
     return -1;
 #else
     struct timeval val;
@@ -142,6 +146,15 @@ int pollSockets(struct pollfd* pollFds, int pollFdsCount, int timeoutMs) {
         }
     }
 
+    return err;
+#elif defined(__3DS__)
+    int err;
+    for (int i = 0; i < timeoutMs; i++) {
+        err = poll(pollFds, pollFdsCount, 1); // need to do this on 3ds since poll will block even if socket is ready before
+        if (err) {
+            break;
+        }
+    }
     return err;
 #else
     return poll(pollFds, pollFdsCount, timeoutMs);
@@ -251,6 +264,11 @@ SOCKET bindUdpSocket(int addressFamily, struct sockaddr_storage* localAddr, SOCK
 #endif
     }
 
+#ifdef __3DS__
+    // binding to wildcard port is broken on the 3DS, so we need to define a port manually
+    struct sockaddr_in *n3ds_addr = &bindAddr;
+    n3ds_addr->sin_port = htons(n3ds_udp_port++);
+#endif
     if (bind(s, (struct sockaddr*) &bindAddr, addrLen) == SOCKET_ERROR) {
         err = LastSocketError();
         Limelog("bind() failed: %d\n", err);
@@ -353,6 +371,9 @@ SOCKET createSocket(int addressFamily, int socketType, int protocol, bool nonBlo
         setsockopt(s, SOL_SOCKET, SO_NOSIGPIPE, (char*)&val, sizeof(val));
     }
 #endif
+#ifdef __3DS__
+    SOCU_AddGlobalSocket(s);
+#endif
 
     if (nonBlocking) {
         setSocketNonBlocking(s, true);
@@ -446,6 +467,17 @@ SOCKET connectTcpSocket(struct sockaddr_storage* dstaddr, SOCKADDR_LEN addrlen,
         SetLastSocketError(ETIMEDOUT);
         return INVALID_SOCKET;
     }
+#ifdef __3DS__ //SO_ERROR is unreliable on 3DS
+    else {
+        char test_buffer[1];
+        err = (int)recv(s, test_buffer, 1, MSG_PEEK);
+        if (err < 0 &&
+            (LastSocketError() == EWOULDBLOCK ||
+            LastSocketError() == EAGAIN)) {
+            err = 0;
+        }
+    }
+#else
     else {
         // The socket was signalled
         SOCKADDR_LEN len = sizeof(err);
@@ -455,6 +487,7 @@ SOCKET connectTcpSocket(struct sockaddr_storage* dstaddr, SOCKADDR_LEN addrlen,
             err = (err != 0) ? err : LastSocketFail();
         }
     }
+#endif
 
     // Disable non-blocking I/O now that the connection is established
     setSocketNonBlocking(s, false);
@@ -723,7 +756,7 @@ int initializePlatformSockets(void) {
 #if defined(LC_WINDOWS)
     WSADATA data;
     return WSAStartup(MAKEWORD(2, 0), &data);
-#elif defined(__vita__) || defined(__WIIU__)
+#elif defined(__vita__) || defined(__WIIU__) || defined(__3DS__)
     return 0; // already initialized
 #elif defined(LC_POSIX) && !defined(LC_CHROME)
     // Disable SIGPIPE signals to avoid us getting

src/PlatformSockets.h

@@ -2,6 +2,15 @@
 
 #include "Limelight.h"
 #include "Platform.h"
+#ifdef __3DS__
+#include <netinet/in.h>
+
+#ifdef AF_INET6
+#undef AF_INET6
+#endif
+
+extern in_port_t n3ds_udp_port;
+#endif
 
 #ifdef _WIN32
 #define WIN32_LEAN_AND_MEAN

src/PlatformThreads.h

@@ -28,6 +28,13 @@ typedef struct _PLT_THREAD {
     OSThread thread;
     int cancelled;
 } PLT_THREAD;
+#elif defined(__3DS__)
+typedef LightLock PLT_MUTEX;
+typedef CondVar PLT_COND;
+typedef struct _PLT_THREAD {
+    Thread thread;
+    bool cancelled;
+} PLT_THREAD;
 #elif defined (LC_POSIX)
 typedef pthread_mutex_t PLT_MUTEX;
 typedef pthread_cond_t PLT_COND;