Network packets should have network byte order

Source/engine.h

@@ -26,6 +26,40 @@
 
 DEVILUTION_BEGIN_NAMESPACE
 
+template <class T>
+T SwapLE(T in)
+{
+	static_assert((sizeof(T) == 1) || (sizeof(T) == 2) || (sizeof(T) == 4) || (sizeof(T) == 8),
+	    "SwapLE called for unsupported size");
+	switch (sizeof(T)) {
+	case 1:
+		return in;
+	case 2:
+		return static_cast<T>(SDL_SwapLE16(static_cast<Uint16>(in)));
+	case 4:
+		return static_cast<T>(SDL_SwapLE32(static_cast<Uint32>(in)));
+	case 8:
+		return static_cast<T>(SDL_SwapLE64(static_cast<Uint64>(in)));
+	}
+}
+
+template <class T>
+T SwapBE(T in)
+{
+	static_assert((sizeof(T) == 1) || (sizeof(T) == 2) || (sizeof(T) == 4) || (sizeof(T) == 8),
+	    "SwapBE called for unsupported size");
+	switch (sizeof(T)) {
+	case 1:
+		return in;
+	case 2:
+		return static_cast<T>(SDL_SwapBE16(static_cast<Uint16>(in)));
+	case 4:
+		return static_cast<T>(SDL_SwapBE32(static_cast<Uint32>(in)));
+	case 8:
+		return static_cast<T>(SDL_SwapBE64(static_cast<Uint64>(in)));
+	}
+}
+
 inline BYTE *CelGetFrameStart(BYTE *pCelBuff, int nCel)
 {
 	DWORD *pFrameTable;
@@ -105,27 +139,43 @@ struct CelOutputBuffer {
 	 *
 	 * Only use this if the buffer owns its data.
 	 */
-	void Free() {
+	void Free()
+	{
 		SDL_FreeSurface(this->surface);
 		this->surface = NULL;
 	}
 
-	int w() const { return region.w; }
-	int h() const { return region.h; }
+	int w() const
+	{
+		return region.w;
+	}
+	int h() const
+	{
+		return region.h;
+	}
 
 	BYTE *at(int x, int y) const
 	{
 		return static_cast<BYTE *>(surface->pixels) + region.x + x + surface->pitch * (region.y + y);
 	}
 
-	BYTE *begin() const { return at(0, 0); }
-	BYTE *end() const { return at(0, region.h); }
+	BYTE *begin() const
+	{
+		return at(0, 0);
+	}
+	BYTE *end() const
+	{
+		return at(0, region.h);
+	}
 
 	/**
 	 * @brief Line width of the raw underlying byte buffer.
 	 * May be wider than its logical width (for power-of-2 alignment).
 	 */
-	int pitch() { return surface->pitch; }
+	int pitch()
+	{
+		return surface->pitch;
+	}
 
 	bool in_bounds(Sint16 x, Sint16 y) const
 	{

Source/loadsave.cpp

@@ -14,36 +14,6 @@ int giNumberOfSmithPremiumItems;
 
 namespace {
 
-template <class T>
-T SwapLE(T in)
-{
-	switch (sizeof(T)) {
-	case 2:
-		return SDL_SwapLE16(in);
-	case 4:
-		return SDL_SwapLE32(in);
-	case 8:
-		return SDL_SwapLE64(in);
-	default:
-		return in;
-	}
-}
-
-template <class T>
-T SwapBE(T in)
-{
-	switch (sizeof(T)) {
-	case 2:
-		return SDL_SwapBE16(in);
-	case 4:
-		return SDL_SwapBE32(in);
-	case 8:
-		return SDL_SwapBE64(in);
-	default:
-		return in;
-	}
-}
-
 class LoadHelper {
 	Uint8 *m_buffer;
 	Uint32 m_bufferPtr = 0;

SourceX/dvlnet/packet.cpp

@@ -1,4 +1,5 @@
 #include "dvlnet/packet.h"
+#include "engine.h"
 
 namespace dvl {
 namespace net {

SourceX/dvlnet/packet.h

@@ -172,6 +172,7 @@ void packet_in::process_element(T &x)
 	if (decrypted_buffer.size() < sizeof(T))
 		throw packet_exception();
 	std::memcpy(&x, decrypted_buffer.data(), sizeof(T));
+	x = SwapBE(x);
 	decrypted_buffer.erase(decrypted_buffer.begin(),
 	    decrypted_buffer.begin() + sizeof(T));
 }
@@ -263,6 +264,7 @@ inline void packet_out::process_element(buffer_t &x)
 template <class T>
 void packet_out::process_element(T &x)
 {
+	x = SwapBE(x);
 	encrypted_buffer.insert(encrypted_buffer.end(), begin(x), end(x));
 }