openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

[IPV6]: Use bitfields for hop_limit and mcast_hops. 

Save some bits for future extensions.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
This commit is contained in:
YOSHIFUJI Hideaki 2008-03-10 10:56:55 -04:00
parent 6b75d09081
commit 1d5d236d30
1 changed files with 24 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
include/linux/ipv6.h
View File

@ -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;