Replace last_added_nonpadding with last_had_circuits

The point of the "idle timeout" for connections is to kill the
connection a while after it has no more circuits.  But using "last
added a non-padding cell" as a proxy for that is wrong, since if the
last circuit is closed from the other side of the connection, we
will not have sent anything on that connection since well before the
last circuit closed.

This is part of fixing 6799.

When applied to 0.2.5, it is also a fix for 12023.

1 files changed, 22 insertions, 7 deletions

diff --git a/src/or/main.c b/src/or/main.c
index 8a653ca40..70b1340cb 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -1003,6 +1003,8 @@ run_connection_housekeeping(int i, time_t now)
   connection_t *conn = smartlist_get(connection_array, i);
   const or_options_t *options = get_options();
   or_connection_t *or_conn;
+  channel_t *chan = NULL;
+  int have_any_circuits;
   int past_keepalive =
     now >= conn->timestamp_lastwritten + options->KeepalivePeriod;
 
@@ -1050,8 +1052,19 @@ run_connection_housekeeping(int i, time_t now)
   tor_assert(conn->outbuf);
 #endif
 
+  chan = TLS_CHAN_TO_BASE(or_conn->chan);
+  tor_assert(chan);
+
+
+  if (channel_num_circuits(chan) != 0) {
+    have_any_circuits = 1;
+    chan->timestamp_last_had_circuits = now;
+  } else {
+    have_any_circuits = 0;
+  }
+
   if (channel_is_bad_for_new_circs(TLS_CHAN_TO_BASE(or_conn->chan)) &&
-      !connection_or_get_num_circuits(or_conn)) {
+      ! have_any_circuits) {
     /* It's bad for new circuits, and has no unmarked circuits on it:
      * mark it now. */
     log_info(LD_OR,
@@ -1070,19 +1083,21 @@ run_connection_housekeeping(int i, time_t now)
       connection_or_close_normally(TO_OR_CONN(conn), 0);
     }
   } else if (we_are_hibernating() &&
-             !connection_or_get_num_circuits(or_conn) &&
+             ! have_any_circuits &&
              !connection_get_outbuf_len(conn)) {
     /* We're hibernating, there's no circuits, and nothing to flush.*/
     log_info(LD_OR,"Expiring non-used OR connection to fd %d (%s:%d) "
              "[Hibernating or exiting].",
              (int)conn->s,conn->address, conn->port);
     connection_or_close_normally(TO_OR_CONN(conn), 1);
-  } else if (!connection_or_get_num_circuits(or_conn) &&
-             now >= or_conn->timestamp_last_added_nonpadding +
-                             or_conn->idle_timeout) {
+  } else if (!have_any_circuits &&
+             now - or_conn->idle_timeout >= chan->timestamp_last_had_circuits) {
     log_info(LD_OR,"Expiring non-used OR connection to fd %d (%s:%d) "
-             "[idle %d].", (int)conn->s,conn->address, conn->port,
-             (int)(now - or_conn->timestamp_last_added_nonpadding));
+             "[no circuits for %d; timeout %d; %scanonical].",
+             (int)conn->s, conn->address, conn->port,
+             (int)(now - chan->timestamp_last_had_circuits),
+             or_conn->idle_timeout,
+             or_conn->is_canonical ? "" : "non");
     connection_or_close_normally(TO_OR_CONN(conn), 0);
   } else if (
       now >= or_conn->timestamp_lastempty + options->KeepalivePeriod*10 &&