[tor-commits] [tor/master] Check the token supply when we received a padding event, too.

[asn at torproject.org]

commit 5638d65f792393a85703342bfb14cc1a60550c18
Author: Mike Perry <mikeperry-git at torproject.org>
Date:   Wed May 15 03:43:57 2019 +0000

    Check the token supply when we received a padding event, too.
    
    We need to check here because otherwise we can try to schedule padding with no
    tokens left upon the receipt of a padding event when our bins just became
    empty.
---
 src/core/or/circuitpadding.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/core/or/circuitpadding.c b/src/core/or/circuitpadding.c
index 3124e7403..cd58a191d 100644
--- a/src/core/or/circuitpadding.c
+++ b/src/core/or/circuitpadding.c
@@ -1699,8 +1699,16 @@ void
 circpad_cell_event_padding_sent(circuit_t *on_circ)
 {
   FOR_EACH_ACTIVE_CIRCUIT_MACHINE_BEGIN(i, on_circ) {
-    circpad_machine_spec_transition(on_circ->padding_info[i],
+    /* Check to see if we've run out of tokens for this state already,
+     * and if not, check for other state transitions */
+    if (check_machine_token_supply(on_circ->padding_info[i])
+        == CIRCPAD_STATE_UNCHANGED) {
+      /* If removing a token did not cause a transition, check if
+       * non-padding sent event should */
+
+      circpad_machine_spec_transition(on_circ->padding_info[i],
                              CIRCPAD_EVENT_PADDING_SENT);
+    }
   } FOR_EACH_ACTIVE_CIRCUIT_MACHINE_END;
 }