From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yan Zheng Subject: [PATH] [MCAST] IPv6: Fix algorithm to compute Querier's Query Interval and Maximum Response Delay Date: Sat, 29 Oct 2005 00:02:32 +0800 Message-ID: <43624B98.6010405@21cn.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org Return-path: To: netdev@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 5.1.3. Maximum Response Code The Maximum Response Code field specifies the maximum time allowed before sending a responding Report. The actual time allowed, called the Maximum Response Delay, is represented in units of milliseconds, and is derived from the Maximum Response Code as follows: If Maximum Response Code < 32768, Maximum Response Delay = 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Maximum Response Delay = (mant | 0x1000) << (exp+3) 5.1.9. QQIC (Querier's Query Interval Code) The Querier's Query Interval Code field specifies the [Query Interval] used by the Querier. The actual interval, called the Querier's Query Interval (QQI), is represented in units of seconds, and is derived from the Querier's Query Interval Code as follows: If QQIC < 128, QQI = QQIC If QQIC >= 128, QQIC represents a floating-point value as follows: 0 1 2 3 4 5 6 7 +-+-+-+-+-+-+-+-+ |1| exp | mant | +-+-+-+-+-+-+-+-+ QQI = (mant | 0x10) << (exp + 3) -- rfc3810 #define MLDV2_QQIC(value) MLDV2_EXP(0x80, 4, 3, value) #define MLDV2_MRC(value) MLDV2_EXP(0x8000, 12, 3, value) Above macro are defined in mcast.c. but 1 << 4 == 0x10 and 1 << 12 == 0x1000. So the result computed by original Macro is larger. Signed-off-by: Yan Zheng Index: net/ipv6/mcast.c =================================================================== --- linux-2.6.14/net/ipv6/mcast.c 2005-10-28 08:02:08.000000000 +0800 +++ linux/net/ipv6/mcast.c 2005-10-28 23:41:18.000000000 +0800 @@ -164,7 +164,7 @@ #define MLDV2_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value)) #define MLDV2_EXP(thresh, nbmant, nbexp, value) \ ((value) < (thresh) ? (value) : \ - ((MLDV2_MASK(value, nbmant) | (1<<(nbmant+nbexp))) << \ + ((MLDV2_MASK(value, nbmant) | (1<<(nbmant))) << \ (MLDV2_MASK((value) >> (nbmant), nbexp) + (nbexp)))) #define MLDV2_QQIC(value) MLDV2_EXP(0x80, 4, 3, value)