[DCCP]: Make dccp_delta_seqno return signed numbers

[safe/jmp/linux-2.6] / net / dccp / dccp.h

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index a2c20a2..afb313f 100644 (file)
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -113,9 +113,12 @@ static inline void dccp_inc_seqno(u64 *seqno)
        *seqno = ADD48(*seqno, 1);
 }
 
-static inline u64 dccp_delta_seqno(u64 seqno1, u64 seqno2)
+/* signed mod-2^48 distance: pos. if seqno1 < seqno2, neg. if seqno1 > seqno2 */
+static inline s64 dccp_delta_seqno(const u64 seqno1, const u64 seqno2)
 {
-       return ((seqno2 << 16) - (seqno1 << 16)) >> 16;
+       u64 delta = SUB48(seqno2, seqno1);
+
+       return TO_SIGNED48(delta);
 }
 
 /* is seq1 < seq2 ? */