From 8d13bf9a0bd4984756e234ce54299b92acefab99 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 20 Mar 2007 13:08:19 -0300 Subject: [PATCH] [DCCP]: Remove ambiguity in the way before48 is used This removes two ambiguities in employing the new definition of before48, following the analysis on http://www.mail-archive.com/dccp@vger.kernel.org/msg01295.html (1) Updating GSR when P.seqno >= S.SWL With the old definition we did not update when P.seqno and S.SWL are 2^47 apart. To ensure the same behaviour as with the old definition, this is replaced with the equivalent condition dccp_delta_seqno(S.SWL, P.seqno) >= 0 (2) Sending SYNC when P.seqno >= S.OSR Here it is debatable whether the new definition causes an ambiguity: the case is similar to (1); and to have consistency with the case (1), we use the equivalent condition dccp_delta_seqno(S.OSR, P.seqno) >= 0 Detailed Justification --- net/dccp/input.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/dccp/input.c b/net/dccp/input.c index 78b043c458bf..a1900157e2d7 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -86,7 +86,8 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) dh->dccph_type == DCCP_PKT_SYNCACK) { if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, dp->dccps_awl, dp->dccps_awh) && - !before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_swl)) + dccp_delta_seqno(dp->dccps_swl, + DCCP_SKB_CB(skb)->dccpd_seq) >= 0) dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq); else return -1; @@ -203,7 +204,8 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, if (dp->dccps_role != DCCP_ROLE_CLIENT) goto send_sync; check_seq: - if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) { + if (dccp_delta_seqno(dp->dccps_osr, + DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { send_sync: dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); -- 2.20.1