From: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Date: Tue, 20 Mar 2007 16:03:47 +0000 (-0300)
Subject: [DCCP]: Fix for follows48
X-Git-Tag: v4.13~39401^2~242
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=b16be51b5e5d75cec71b18ebc75f15a4734c62ad;p=mirror_ubuntu-bionic-kernel.git

[DCCP]: Fix for follows48

The follows48 relation identifies whether 48-bit sequence number
x is the direct successor of y. Currently, it does not handle cases
of the following type correctly:

	follows48(0x(prefix)10000LL, 0x(prefix)0FFFFLL)

where prefix is an arbitrary hex sequence of up to 7 digits.

This is fixed by reusing the new dccp_delta_seqno function.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 1615986a8d92..c66a4581348f 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -144,9 +144,7 @@ static inline u64 max48(const u64 seq1, const u64 seq2)
 /* is seq1 next seqno after seq2 */
 static inline int follows48(const u64 seq1, const u64 seq2)
 {
-	int diff = (seq1 & 0xFFFF) - (seq2 & 0xFFFF);
-
-	return diff==1;
+	return dccp_delta_seqno(seq2, seq1) == 1;
 }
 
 enum {