[tor-commits] [stegotorus/master] Attempt to prevent event callbacks from firing on partially torn down circuits/connections.

[zwol at torproject.org]

commit 68d78ec5e93c2b48a3d95e9b50c0498580a1d97a
Author: Zack Weinberg <zackw at cmu.edu>
Date:   Wed Jun 20 14:41:38 2012 -0700

    Attempt to prevent event callbacks from firing on partially torn down circuits/connections.
---
 src/protocol/chop.cc |   18 ++++++++++++++++--
 src/protocol/null.cc |   15 +++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/protocol/chop.cc b/src/protocol/chop.cc
index 0d914d8..cde40b2 100644
--- a/src/protocol/chop.cc
+++ b/src/protocol/chop.cc
@@ -579,6 +579,15 @@ chop_circuit_t::chop_circuit_t()
 
 chop_circuit_t::~chop_circuit_t()
 {
+  // Attempt to prevent events from firing on partially or completely
+  // torn down circuits.  (This shouldn't happen, but it seems to.)
+  if (this->up_buffer)
+    bufferevent_disable(this->up_buffer, EV_READ|EV_WRITE);
+  if (this->flush_timer)
+    event_del(this->flush_timer);
+  if (this->axe_timer)
+    event_del(this->axe_timer);
+
   if (!sent_fin || !received_fin || !upstream_eof) {
     log_warn(this, "destroying active circuit: fin%c%c eof%c ds=%lu",
              sent_fin ? '+' : '-', received_fin ? '+' : '-',
@@ -1115,12 +1124,17 @@ chop_conn_t::chop_conn_t()
 
 chop_conn_t::~chop_conn_t()
 {
+  // Attempt to prevent events from firing on partially or completely
+  // torn down connections.  (This shouldn't happen, but it seems to.)
+  if (this->buffer)
+    bufferevent_disable(this->buffer, EV_READ|EV_WRITE);
+
+  if (this->must_send_timer)
+    event_free(this->must_send_timer);
   if (upstream)
     upstream->drop_downstream(this);
   if (steg)
     delete steg;
-  if (must_send_timer)
-    event_free(must_send_timer);
   evbuffer_free(recv_pending);
 }
 
diff --git a/src/protocol/null.cc b/src/protocol/null.cc
index 7467de1..e195cc9 100644
--- a/src/protocol/null.cc
+++ b/src/protocol/null.cc
@@ -8,6 +8,7 @@
 #include "protocol.h"
 
 #include <event2/buffer.h>
+#include <event2/event.h>
 
 namespace {
   struct null_config_t : config_t
@@ -134,6 +135,15 @@ null_circuit_t::null_circuit_t()
 
 null_circuit_t::~null_circuit_t()
 {
+  // Attempt to prevent events from firing on partially or completely
+  // torn down circuits.  (This shouldn't happen, but it seems to.)
+  if (this->up_buffer)
+    bufferevent_disable(this->up_buffer, EV_READ|EV_WRITE);
+  if (this->flush_timer)
+    event_del(this->flush_timer);
+  if (this->axe_timer)
+    event_del(this->axe_timer);
+
   if (downstream) {
     /* break the circular reference before deallocating the
        downstream connection */
@@ -232,6 +242,11 @@ null_conn_t::null_conn_t()
 
 null_conn_t::~null_conn_t()
 {
+  // Attempt to prevent events from firing on partially or completely
+  // torn down connections.  (This shouldn't happen, but it seems to.)
+  if (this->buffer)
+    bufferevent_disable(this->buffer, EV_READ|EV_WRITE);
+
   if (this->upstream)
     this->upstream->drop_downstream(this);
 }