1 files changed, 16 insertions, 1 deletions

diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index f44d492d3b74..32617e0576cb 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 */
@@ -262,7 +277,7 @@ extern int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
                                 const struct dccp_hdr *dh, const unsigned len);
 
 extern int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
-extern int dccp_destroy_sock(struct sock *sk);
+extern void dccp_destroy_sock(struct sock *sk);
 
 extern void             dccp_close(struct sock *sk, long timeout);
 extern struct sk_buff   *dccp_make_response(struct sock *sk,