net/byteorder: fix 64 bit ntohq and htonq on big endian machines

Uses predefined GNU preprocessor macros to detect endianness. This seems portable enough for now. htonq calls ntohq since they have identical implementations. Message-Id: <[email protected]>
spurnaye · Sep 6, 2017 · 31b925d · 31b925d
1 parent 1012a6c
commit 31b925d
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/net/byteorder.hh b/net/byteorder.hh
@@ -31,10 +31,17 @@
 namespace seastar {
 
 inline uint64_t ntohq(uint64_t v) {
+#if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+    // big endian, nothing to do
+    return v;
+#else
+    // little endian, reverse bytes
     return __builtin_bswap64(v);
+#endif
 }
 inline uint64_t htonq(uint64_t v) {
-    return __builtin_bswap64(v);
+    // htonq and ntohq have identical implementations
+    return ntohq(v);
 }
 
 namespace net {