Implement 32-bit DO_* for arches with alignment restrictions.

Fixes compilation for MIPS.

util.h

@@ -28,21 +28,23 @@ THE SOFTWARE.
 /* Some versions of gcc seem to be buggy, and ignore the packed attribute.
    Disable this code until the issue is clarified. */
 /* #elif defined __GNUC__*/
-#elif 0
-struct __us { unsigned short x __attribute__((packed)); };
-#define DO_NTOHS(_d, _s) \
-    do { _d = ntohs(((const struct __us*)(_s))->x); } while(0)
-#define DO_HTONS(_d, _s) \
-    do { ((struct __us*)(_d))->x = htons(_s); } while(0)
 #else
 #define DO_NTOHS(_d, _s) \
     do { short _dd; \
          memcpy(&(_dd), (_s), 2); \
          _d = ntohs(_dd); } while(0)
+#define DO_NTOHL(_d, _s) \
+    do { int _dd; \
+         memcpy(&(_dd), (_s), 4); \
+         _d = ntohl(_dd); } while(0)
 #define DO_HTONS(_d, _s) \
     do { unsigned short _dd; \
          _dd = htons(_s); \
          memcpy((_d), &(_dd), 2); } while(0)
+#define DO_HTONL(_d, _s) \
+    do { unsigned _dd; \
+         _dd = htonl(_s); \
+         memcpy((_d), &(_dd), 4); } while(0)
 #endif
 
 static inline int