[DCCP] ccid3: Fix calculation of t_ipi time of scheduled transmission

Problem:

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index df88c54..fb1a5e8 100644 (file)
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -304,11 +304,19 @@ static int ccid3_hc_tx_send_packet(struct sock *sk,
                break;
        case TFRC_SSTATE_NO_FBACK:
        case TFRC_SSTATE_FBACK:
-               delay = (timeval_delta(&now, &hctx->ccid3hctx_t_nom) -
-                        hctx->ccid3hctx_delta);
-               delay /= -1000;
-               /* divide by -1000 is to convert to ms and get sign right */
-               rc = delay > 0 ? delay : 0;
+               delay = timeval_delta(&hctx->ccid3hctx_t_nom, &now);
+               /*
+                *      Scheduling of packet transmissions [RFC 3448, 4.6]
+                *
+                * if (t_now > t_nom - delta)
+                *       // send the packet now
+                * else
+                *       // send the packet in (t_nom - t_now) milliseconds.
+                */
+               if (delay < hctx->ccid3hctx_delta)
+                       rc = 0;
+               else
+                       rc = delay/1000L;
                break;
        case TFRC_SSTATE_TERM:
                DCCP_BUG("Illegal %s state TERM, sk=%p", dccp_role(sk), sk);