Be more proactive about closing unused circuits.

We need to ensure that we close timeout measurement circuits. While
we're at it, we should close really old circuits of certain types that
aren't in use, and log really old circuits of other types.

src/or/circuituse.c

@@ -717,17 +717,27 @@ circuit_expire_old_circuits_clientside(time_t now)
                 circ->n_circ_id, (int)(now - circ->timestamp_dirty),
                 circ->purpose);
       circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
-    // XXX: Do we ever mark non-dirty odd-purpose circuits for close?
-    // XXX: See irc backlog. Want to log for those circuits not mentioned.
-    //      But remember to add flag. this is called 1x/sec
-    } else if (!circ->timestamp_dirty &&
-               circ->state == CIRCUIT_STATE_OPEN &&
-               circ->purpose == CIRCUIT_PURPOSE_C_GENERAL) {
+    } else if (!circ->timestamp_dirty && circ->state == CIRCUIT_STATE_OPEN) {
       if (circ->timestamp_created < cutoff) {
-        log_debug(LD_CIRC,
-                  "Closing circuit that has been unused for %d seconds.",
-                  (int)(now - circ->timestamp_created));
-        circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+        if (circ->purpose == CIRCUIT_PURPOSE_C_GENERAL ||
+                circ->purpose == CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT ||
+                circ->purpose == CIRCUIT_PURPOSE_S_ESTABLISH_INTRO ||
+                circ->purpose == CIRCUIT_PURPOSE_TESTING ||
+                (circ->purpose >= CIRCUIT_PURPOSE_C_INTRODUCING &&
+                circ->purpose <= CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED) ||
+                circ->purpose == CIRCUIT_PURPOSE_S_CONNECT_REND) {
+          log_debug(LD_CIRC,
+                    "Closing circuit that has been unused for %d seconds.",
+                    (int)(now - circ->timestamp_created));
+          circuit_mark_for_close(circ, END_CIRC_REASON_FINISHED);
+        } else if (!TO_ORIGIN_CIRCUIT(circ)->is_ancient) {
+          log_notice(LD_CIRC,
+                     "Ancient non-dirty circuit %d is still around after "
+                     "%ld seconds.",
+                     TO_ORIGIN_CIRCUIT(circ)->global_identifier,
+                     now - circ->timestamp_created);
+          TO_ORIGIN_CIRCUIT(circ)->is_ancient = 1;
+        }
       }
     }
   }

src/or/or.h

@@ -2157,6 +2157,9 @@ typedef struct origin_circuit_t {
    * to the specification? */
   unsigned int remaining_relay_early_cells : 4;
 
+  /** Set if this circuit insanely old and if we already informed the user */
+  unsigned int is_ancient : 1;
+
   /** What commands were sent over this circuit that decremented the
    * RELAY_EARLY counter? This is for debugging task 878. */
   uint8_t relay_early_commands[MAX_RELAY_EARLY_CELLS_PER_CIRCUIT];