Socket: Fix some errors related to non-blocking connect

Source/Core/Core/IOS/Network/Socket.cpp

@@ -575,6 +575,16 @@ void WiiSocket::Update(bool read, bool write, bool except)
         {
         case IOCTLV_SO_SENDTO:
         {
+          // The Wii allows a socket with a connection in progress to use
+          // sendto(). This might not be supported by the operating system.
+          // We have to enforce it manually.
+          connecting_state = GetConnectingState();
+          if (nonBlock && IsTCP() && connecting_state == ConnectingState::Connecting)
+          {
+            ReturnValue = -SO_EAGAIN;
+            break;
+          }
+
           u32 flags = Memory::Read_U32(BufferIn2 + 0x04);
           u32 has_destaddr = Memory::Read_U32(BufferIn2 + 0x08);
 
@@ -612,6 +622,16 @@ void WiiSocket::Update(bool read, bool write, bool except)
         }
         case IOCTLV_SO_RECVFROM:
         {
+          // The Wii allows a socket with a connection in progress to use
+          // recvfrom(). This might not be supported by the operating system.
+          // We have to enforce it manually.
+          connecting_state = GetConnectingState();
+          if (nonBlock && IsTCP() && connecting_state == ConnectingState::Connecting)
+          {
+            ReturnValue = -SO_EAGAIN;
+            break;
+          }
+
           u32 flags = Memory::Read_U32(BufferIn + 0x04);
           // Not a string, Windows requires a char* for recvfrom
           char* data = (char*)Memory::GetPointer(BufferOut);
@@ -791,6 +811,18 @@ WiiSocket::ConnectingState WiiSocket::GetConnectingState() const
   return connecting_state;
 }
 
+bool WiiSocket::IsTCP() const
+{
+  const auto state = Common::SaveNetworkErrorState();
+  Common::ScopeGuard guard([&state] { Common::RestoreNetworkErrorState(state); });
+
+  int socket_type;
+  socklen_t option_length = sizeof(socket_type);
+  return getsockopt(fd, SOL_SOCKET, SO_TYPE, reinterpret_cast<char*>(&socket_type),
+                    &option_length) == 0 &&
+         socket_type == SOCK_STREAM;
+}
+
 const WiiSocket::Timeout& WiiSocket::GetTimeout()
 {
   if (!timeout.has_value())

Source/Core/Core/IOS/Network/Socket.h

@@ -223,6 +223,7 @@ private:
   void UpdateConnectingState(s32 connect_rv);
   ConnectingState GetConnectingState() const;
   bool IsValid() const { return fd >= 0; }
+  bool IsTCP() const;
 
   s32 fd = -1;
   s32 wii_fd = -1;