diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/mld.h | 66 |
1 files changed, 57 insertions, 9 deletions
diff --git a/include/net/mld.h b/include/net/mld.h index c07359808493..10e402e0fe08 100644 --- a/include/net/mld.h +++ b/include/net/mld.h @@ -89,29 +89,77 @@ struct mld2_query { #define MLDV2_QQIC_EXP(value) (((value) >> 4) & 0x07) #define MLDV2_QQIC_MAN(value) ((value) & 0x0f) -#define MLD_EXP_MIN_LIMIT 32768UL -#define MLDV1_MRD_MAX_COMPAT (MLD_EXP_MIN_LIMIT - 1) +/* MLDv2 QQIC floating-point exponential field min threshold */ +#define MLD_QQIC_MIN_THRESHOLD 128 +/* MLDv2 MRC floating-point exponential field min threshold */ +#define MLD_MRC_MIN_THRESHOLD 32768UL +#define MLDV1_MRD_MAX_COMPAT (MLD_MRC_MIN_THRESHOLD - 1) #define MLD_MAX_QUEUE 8 #define MLD_MAX_SKBS 32 -static inline unsigned long mldv2_mrc(const struct mld2_query *mlh2) +/* V2 exponential field decoding */ + +/* Calculate Maximum Response Delay from Maximum Response Code + * + * RFC3810, relevant sections: + * - 5.1.3. Maximum Response Code defines the decoding formula: + * 0 1 2 3 4 5 6 7 8 9 A B C D E F + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |1| exp | mant | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * Maximum Response Delay = (mant | 0x1000) << (exp+3) + * - 9.3. Query Response Interval + * + * After decode, MRC represents the Maximum Response Delay (MRD) in + * units of milliseconds. + */ +static inline unsigned long mldv2_mrd(const struct mld2_query *mlh2) { - /* RFC3810, 5.1.3. Maximum Response Code */ - unsigned long ret, mc_mrc = ntohs(mlh2->mld2q_mrc); + unsigned long mc_mrc = ntohs(mlh2->mld2q_mrc); - if (mc_mrc < MLD_EXP_MIN_LIMIT) { - ret = mc_mrc; + if (mc_mrc < MLD_MRC_MIN_THRESHOLD) { + return 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 (mc_man | 0x1000) << (mc_exp + 3); } +} - return ret; +/* Calculate Querier's Query Interval from Querier's Query Interval Code + * + * RFC3810, relevant sections: + * - 5.1.9. QQIC (Querier's Query Interval Code) defines the decoding formula: + * 0 1 2 3 4 5 6 7 + * +-+-+-+-+-+-+-+-+ + * |1| exp | mant | + * +-+-+-+-+-+-+-+-+ + * QQI = (mant | 0x10) << (exp + 3) + * - 9.2. Query Interval + * - 9.12. Older Version Querier Present Timeout + * (the [Query Interval] in the last Query received) + * + * After decode, QQIC represents the Querier's Query Interval in units + * of seconds. + */ +static inline unsigned long mldv2_qqi(const struct mld2_query *mlh2) +{ + unsigned long qqic = mlh2->mld2q_qqic; + + if (qqic < MLD_QQIC_MIN_THRESHOLD) { + return qqic; + } else { + unsigned long mc_man, mc_exp; + + mc_exp = MLDV2_QQIC_EXP(qqic); + mc_man = MLDV2_QQIC_MAN(qqic); + + return (mc_man | 0x10) << (mc_exp + 3); + } } #endif |