From 2013c7e35aeba39777f9b3eef8a70207b3931152 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 13 Jul 2008 11:51:40 +0100 Subject: dccp ccid-3: Fix error in loss detection The TFRC loss detection code used the wrong loss condition (RFC 4340, 7.7.1): * the difference between sequence numbers s1 and s2 instead of * the number of packets missing between s1 and s2 (one less than the distance). Since this condition appears in many places of the code, it has been put into a separate function, dccp_loss_free(). Further changes: ---------------- * tidied up incorrect typing (it was using `int' for u64/s64 types); * optimised conditional statements for common case of non-reordered packets; * rewrote comments/documentation to match the changes. Signed-off-by: Gerrit Renker --- net/dccp/dccp.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'net/dccp/dccp.h') diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 1b2cea244e1..32617e0576c 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -153,6 +153,21 @@ static inline u64 max48(const u64 seq1, const u64 seq2) return after48(seq1, seq2) ? seq1 : seq2; } +/** + * dccp_loss_free - Evaluates condition for data loss from RFC 4340, 7.7.1 + * @s1: start sequence number + * @s2: end sequence number + * @ndp: NDP count on packet with sequence number @s2 + * Returns true if the sequence range s1...s2 has no data loss. + */ +static inline bool dccp_loss_free(const u64 s1, const u64 s2, const u64 ndp) +{ + s64 delta = dccp_delta_seqno(s1, s2); + + BUG_TRAP(delta >= 0); + return (u64)delta <= ndp + 1; +} + enum { DCCP_MIB_NUM = 0, DCCP_MIB_ACTIVEOPENS, /* ActiveOpens */ -- cgit v1.2.3