rx: Add Karn-style backoffs to RX retransmits

[openafs.git] / src / rx / rx.c

diff --git a/src/rx/rx.c b/src/rx/rx.c
index 772e5c2..ade91cd 100644 (file)
--- a/src/rx/rx.c
+++ b/src/rx/rx.c
@@ -5919,6 +5919,7 @@ rxi_Resend(struct rxevent *event, void *arg0, void *arg1, int istack)
 {
     struct rx_call *call = arg0;
     struct rx_packet *p, *nxp;
+    struct clock maxTimeout = { 60, 0 };
 
     MUTEX_ENTER(&call->lock);
     /* Make sure that the event pointer is removed from the call
@@ -5947,6 +5948,16 @@ rxi_Resend(struct rxevent *event, void *arg0, void *arg1, int istack)
        if (!(p->flags & RX_PKTFLAG_ACKED))
            p->flags &= ~RX_PKTFLAG_SENT;
     }
+
+    /* We're resending, so we double the timeout of the call. This will be
+     * dropped back down by the first successful ACK that we receive.
+     *
+     * We apply a maximum value here of 60 second
+     */
+    clock_Add(&call->rto, &call->rto);
+    if (clock_Gt(&call->rto, &maxTimeout))
+       call->rto = maxTimeout;
+
     rxi_Start(call, istack);
 
 out: