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| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2007-03-20 16:08:19 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 05:26:46 (GMT) |
| commit | 8d13bf9a0bd4984756e234ce54299b92acefab99 (patch) | |
| tree | 3a5fa39fec52b934d0d86afe93423cb9bb5ded20 | |
| parent | b16be51b5e5d75cec71b18ebc75f15a4734c62ad (diff) | |
| download | linux-8d13bf9a0bd4984756e234ce54299b92acefab99.tar.xz | |
[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
| -rw-r--r-- | net/dccp/input.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/dccp/input.c b/net/dccp/input.c index 78b043c..a190015 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); |