[IPV6]: Use bitfields for hop_limit and mcast_hops.
Save some bits for future extensions.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 9b59e37..87ae4e3 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -274,8 +274,29 @@
__be32 flow_label;
__u32 frag_size;
- __s16 hop_limit;
- __s16 mcast_hops;
+
+ /*
+ * Packed in 16bits.
+ * Omit one shift by by putting the signed field at MSB.
+ */
+#if defined(__BIG_ENDIAN_BITFIELD)
+ __s16 hop_limit:9;
+ __u16 __unused_1:7;
+#else
+ __u16 __unused_1:7;
+ __s16 hop_limit:9;
+#endif
+
+#if defined(__BIG_ENDIAN_BITFIELD)
+ /* Packed in 16bits. */
+ __s16 mcast_hops:9;
+ __u16 __unused_2:6,
+ mc_loop:1;
+#else
+ __u16 mc_loop:1,
+ __unused_2:6;
+ __s16 mcast_hops:9;
+#endif
int mcast_oif;
/* pktoption flags */
@@ -298,8 +319,7 @@
} rxopt;
/* sockopt flags */
- __u8 mc_loop:1,
- recverr:1,
+ __u8 recverr:1,
sndflow:1,
pmtudisc:2,
ipv6only:1;