dccp ccid-3: Length of loss intervals

This corrects an error in the computation of the open loss interval I_0:
  * the interval length is (highest_seqno - start_seqno) + 1
  * and not (highest_seqno - start_seqno).

This condition was not fully clear in RFC 3448, but reflects the current
revision state of rfc3448bis and is also consistent with RFC 4340, 6.1.1.

Further changes:
----------------
 * variable renamed due to line length constraints;
 * explicit typecast to `s64' to avoid implicit signed/unsigned casting.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

diff --git a/net/dccp/ccids/lib/loss_interval.c b/net/dccp/ccids/lib/loss_interval.c
index 849e181..bcd6ac4 100644 (file)
--- a/net/dccp/ccids/lib/loss_interval.c
+++ b/net/dccp/ccids/lib/loss_interval.c
@@ -90,14 +90,14 @@ u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb)
 {
        struct tfrc_loss_interval *cur = tfrc_lh_peek(lh);
        u32 old_i_mean = lh->i_mean;
-       s64 length;
+       s64 len;
 
        if (cur == NULL)                        /* not initialised */
                return 0;
 
-       length = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq);
+       len = dccp_delta_seqno(cur->li_seqno, DCCP_SKB_CB(skb)->dccpd_seq) + 1;
 
-       if (length - cur->li_length <= 0)       /* duplicate or reordered */
+       if (len - (s64)cur->li_length <= 0)     /* duplicate or reordered */
                return 0;
 
        if (SUB16(dccp_hdr(skb)->dccph_ccval, cur->li_ccval) > 4)
@@ -114,7 +114,7 @@ u8 tfrc_lh_update_i_mean(struct tfrc_loss_hist *lh, struct sk_buff *skb)
        if (tfrc_lh_length(lh) == 1)            /* due to RFC 3448, 6.3.1 */
                return 0;
 
-       cur->li_length = length;
+       cur->li_length = len;
        tfrc_lh_calc_i_mean(lh);
 
        return (lh->i_mean < old_i_mean);
@@ -159,7 +159,7 @@ int tfrc_lh_interval_add(struct tfrc_loss_hist *lh, struct tfrc_rx_hist *rh,
        else {
                cur->li_length = dccp_delta_seqno(cur->li_seqno, new->li_seqno);
                new->li_length = dccp_delta_seqno(new->li_seqno,
-                                 tfrc_rx_hist_last_rcv(rh)->tfrchrx_seqno);
+                                 tfrc_rx_hist_last_rcv(rh)->tfrchrx_seqno) + 1;
                if (lh->counter > (2*LIH_SIZE))
                        lh->counter -= LIH_SIZE;