Introduce a notion of 'internal' circs, which are chosen without regard

to the exit policy of the last hop. Intro and rendezvous circs must
be internal circs, to avoid leaking information. Resolve and connect
streams can use internal circs if they want.

New circuit pooling algorithm: make sure to have enough circs around
to satisfy any predicted ports, and also make sure to have 2 internal
circs around if we've required internal circs lately (with high uptime
if we've seen that lately).

Split NewCircuitPeriod config option into NewCircuitPeriod (30 secs),
which describes how often we retry making new circuits if current ones
are dirty, and MaxCircuitDirtiness (10 mins), which describes how long
we're willing to make use of an already-dirty circuit.

Once rendezvous circuits are established, keep using the same circuit as
long as you attach a new stream to it at least every 10 minutes. (So web
browsing doesn't require you to build new rend circs every 30 seconds.)

Cannibalize GENERAL circs to be C_REND, C_INTRO, S_INTRO, and S_REND
circ as necessary, if there are any completed ones lying around when
we try to launch one.

Re-instate the ifdef's to use version-0 style introduce cells, since
there was yet another bug in handling version-1 style. We'll try switching
over again after 0.0.9 is obsolete.

Bugfix: when choosing an exit node for a new non-internal circ, don't take
into account whether it'll be useful for any pending x.onion addresses --
it won't.

Bugfix: we weren't actually publishing the hidden service descriptor when
it became dirty. So we only published it every 20 minutes or so, which
means when you first start your Tor, the hidden service will seem broken.


svn:r3360

1 files changed, 13 insertions, 25 deletions

diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 11c7be3e80..643e360c35 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -292,41 +292,29 @@ circuit_t *circuit_get_rendezvous(const char *cookie)
   return NULL;
 }
 
-/** Count the number of circs originating here that aren't open, and
- * that have the specified <b>purpose</b>. */
-int circuit_count_building(uint8_t purpose) {
-  circuit_t *circ;
-  int num=0;
-
-  for (circ=global_circuitlist;circ;circ = circ->next) {
-    if (CIRCUIT_IS_ORIGIN(circ) &&
-       circ->state != CIRCUIT_STATE_OPEN &&
-       circ->purpose == purpose &&
-       !circ->marked_for_close)
-      num++;
-  }
-  return num;
-}
-
-/** Return the circuit that is open, has specified <b>purpose</b>,
- * has a timestamp_dirty value of 0, and was created most recently,
- * or NULL if no circuit fits this description.
+/** Return a circuit that is open, has specified <b>purpose</b>,
+ * has a timestamp_dirty value of 0, and is uptime/capacity/internal
+ * if required; or NULL if no circuit fits this description.
  */
 circuit_t *
-circuit_get_youngest_clean_open(uint8_t purpose) {
+circuit_get_clean_open(uint8_t purpose, int need_uptime,
+                       int need_capacity, int internal) {
   circuit_t *circ;
-  circuit_t *youngest=NULL;
 
-  for (circ=global_circuitlist;circ;circ = circ->next) {
+  log_fn(LOG_DEBUG,"Hunting for a circ to cannibalize: purpose %d, uptime %d, capacity %d, internal %d", purpose, need_uptime, need_capacity, internal);
+
+  for (circ=global_circuitlist; circ; circ = circ->next) {
     if (CIRCUIT_IS_ORIGIN(circ) &&
         circ->state == CIRCUIT_STATE_OPEN &&
         !circ->marked_for_close &&
         circ->purpose == purpose &&
         !circ->timestamp_dirty &&
-        (!youngest || youngest->timestamp_created < circ->timestamp_created))
-      youngest = circ;
+        (!need_uptime || circ->build_state->need_uptime) &&
+        (!need_capacity || circ->build_state->need_capacity) &&
+        (!internal || circ->build_state->is_internal))
+      return circ;
   }
-  return youngest;
+  return NULL;
 }
 
 /** Mark <b>circ</b> to be closed next time we call