linux/include/net/mld.h
Daniel Borkmann e3f5b17047 net: ipv6: mld: get rid of MLDV2_MRC and simplify calculation
Get rid of MLDV2_MRC and use our new macros for mantisse and
exponent to calculate Maximum Response Delay out of the Maximum
Response Code.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-04 14:53:20 -04:00

110 lines
2.7 KiB
C

#ifndef LINUX_MLD_H
#define LINUX_MLD_H
#include <linux/in6.h>
#include <linux/icmpv6.h>
/* MLDv1 Query/Report/Done */
struct mld_msg {
struct icmp6hdr mld_hdr;
struct in6_addr mld_mca;
};
#define mld_type mld_hdr.icmp6_type
#define mld_code mld_hdr.icmp6_code
#define mld_cksum mld_hdr.icmp6_cksum
#define mld_maxdelay mld_hdr.icmp6_maxdelay
#define mld_reserved mld_hdr.icmp6_dataun.un_data16[1]
/* Multicast Listener Discovery version 2 headers */
/* MLDv2 Report */
struct mld2_grec {
__u8 grec_type;
__u8 grec_auxwords;
__be16 grec_nsrcs;
struct in6_addr grec_mca;
struct in6_addr grec_src[0];
};
struct mld2_report {
struct icmp6hdr mld2r_hdr;
struct mld2_grec mld2r_grec[0];
};
#define mld2r_type mld2r_hdr.icmp6_type
#define mld2r_resv1 mld2r_hdr.icmp6_code
#define mld2r_cksum mld2r_hdr.icmp6_cksum
#define mld2r_resv2 mld2r_hdr.icmp6_dataun.un_data16[0]
#define mld2r_ngrec mld2r_hdr.icmp6_dataun.un_data16[1]
/* MLDv2 Query */
struct mld2_query {
struct icmp6hdr mld2q_hdr;
struct in6_addr mld2q_mca;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 mld2q_qrv:3,
mld2q_suppress:1,
mld2q_resv2:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u8 mld2q_resv2:4,
mld2q_suppress:1,
mld2q_qrv:3;
#else
#error "Please fix <asm/byteorder.h>"
#endif
__u8 mld2q_qqic;
__be16 mld2q_nsrcs;
struct in6_addr mld2q_srcs[0];
};
#define mld2q_type mld2q_hdr.icmp6_type
#define mld2q_code mld2q_hdr.icmp6_code
#define mld2q_cksum mld2q_hdr.icmp6_cksum
#define mld2q_mrc mld2q_hdr.icmp6_maxdelay
#define mld2q_resv1 mld2q_hdr.icmp6_dataun.un_data16[1]
/* RFC3810, 5.1.3. Maximum Response Code:
*
* If Maximum Response Code >= 32768, Maximum Response Code represents a
* floating-point value as follows:
*
* 0 1 2 3 4 5 6 7 8 9 A B C D E F
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |1| exp | mant |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
#define MLDV2_MRC_EXP(value) (((value) >> 12) & 0x0007)
#define MLDV2_MRC_MAN(value) ((value) & 0x0fff)
/* RFC3810, 5.1.9. QQIC (Querier's Query Interval Code):
*
* If QQIC >= 128, QQIC represents a floating-point value as follows:
*
* 0 1 2 3 4 5 6 7
* +-+-+-+-+-+-+-+-+
* |1| exp | mant |
* +-+-+-+-+-+-+-+-+
*/
#define MLDV2_QQIC_EXP(value) (((value) >> 4) & 0x07)
#define MLDV2_QQIC_MAN(value) ((value) & 0x0f)
static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2)
{
/* RFC3810, 5.1.3. Maximum Response Code */
unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc);
if (mc_mrc < 32768) {
ret = mc_mrc;
} else {
unsigned long mc_man, mc_exp;
mc_exp = MLDV2_MRC_EXP(mc_mrc);
mc_man = MLDV2_MRC_MAN(mc_mrc);
ret = (mc_man | 0x1000) << (mc_exp + 3);
}
return ret;
}
#endif