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

Problem:

1 files changed, 13 insertions, 5 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index df88c54b2ec5..fb1a5e89c023 100644
--- 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);