From 1d5d236d309ab90fa6aedf712f586b3595721373 Mon Sep 17 00:00:00 2001 From: YOSHIFUJI Hideaki Date: Mon, 10 Mar 2008 10:56:55 -0400 Subject: [PATCH] [IPV6]: Use bitfields for hop_limit and mcast_hops. Save some bits for future extensions. Signed-off-by: YOSHIFUJI Hideaki --- include/linux/ipv6.h | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 9b59e37afad9..87ae4e389ce1 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -274,8 +274,29 @@ struct ipv6_pinfo { __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 @@ struct ipv6_pinfo { } rxopt; /* sockopt flags */ - __u8 mc_loop:1, - recverr:1, + __u8 recverr:1, sndflow:1, pmtudisc:2, ipv6only:1; -- 2.20.1