Read "circwindow=x" from the consensus and use it

Tor now reads the "circwindow" parameter out of the consensus,
and uses that value for its circuit package window rather than the
default of 1000 cells. Begins the implementation of proposal 168.

1 files changed, 13 insertions, 1 deletions

diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 065559620c..e1da117168 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -361,6 +361,18 @@ circuit_purpose_to_controller_string(uint8_t purpose)
   }
 }
 
+/** Pick a reasonable package_window to start out for our circuits.
+ * Originally this was hard-coded at 1000, but now the consensus votes
+ * on the answer. See proposal 168. */
+int32_t
+circuit_initial_package_window(void)
+{
+  networkstatus_t *consensus = networkstatus_get_latest_consensus();
+  if (consensus)
+    return networkstatus_get_param(consensus, "circwindow", CIRCWINDOW_START);
+  return CIRCWINDOW_START;
+}
+
 /** Initialize the common elements in a circuit_t, and add it to the global
  * list. */
 static void
@@ -368,7 +380,7 @@ init_circuit_base(circuit_t *circ)
 {
   circ->timestamp_created = time(NULL);
 
-  circ->package_window = CIRCWINDOW_START;
+  circ->package_window = circuit_initial_package_window();
   circ->deliver_window = CIRCWINDOW_START;
 
   circuit_add(circ);