Merge remote-tracking branch 'public/ticket6799_024_v2_squashed'

Conflicts:
	src/or/channel.c
	src/or/circuitlist.c
	src/or/connection.c

Conflicts involved removal of next_circ_id and addition of
unusable-circid tracking.

1 files changed, 20 insertions, 0 deletions

diff --git a/changes/bug6799 b/changes/bug6799
new file mode 100644
index 000000000..72b6519a2
--- /dev/null
+++ b/changes/bug6799
@@ -0,0 +1,20 @@
+  o Major features:
+
+    - Increase the base amount of time that a canonical connection
+      (one that we have made to a known OR) is allowed to stay idle
+      from 3 minutes to 15 minutes.  This leaks less information
+      about when circuits have closed, and avoids unnecessary overhead
+      from renegotiating connections. Part of a fix for ticket 6799.
+
+    - Instead of closing connections after they have been idle for a
+      fixed interval, randomly add up to 50% to each connection's
+      maximum timeout. This makes it harder to tell when the last
+      circuit closed by looking at when a connection closes. Part of a
+      fix for ticket 6799.
+
+    - Base connection idleness tests on the actual time elapsed since
+      the connection last had circuits, not on the time when we last
+      added non-padding. This change also makes it harder for an
+      observer to tell when the last circuit closed by looking at when
+      a connection closes. Part of a fix for ticket 6799.
+      Incidentally fixes bug 12023; bugfix on 0.2.5.1-alpha.