Backport to 0.2.0.x: Never allow a circuit to be created with the same circid as a circuit that has been marked for close. May fix 779. Needs testing.

svn:r16463

5 files changed, 16 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 87865dab95..868753b525 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,9 @@
 Changes in version 0.2.0.31 - 2008-08-??
+ o Major bugfixes:
+    - Make sure that two circuits can never exist on the same connection
+      with the same circuit ID, even if one is marked for close.  This
+      is conceivably a bugfix for bug 779; fixes a bug on 0.1.0.4-rc.
+
  o Minor bugfixes:
     - Fix a small alignment and memory-wasting bug on buffer chunks.  Spotted
       by rovv.
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index bb302836f7..3be2689995 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -99,7 +99,7 @@ get_unique_circ_id_by_conn(or_connection_t *conn)
       return 0;
     }
     test_circ_id |= high_bit;
-  } while (circuit_get_by_circid_orconn(test_circ_id, conn));
+  } while (circuit_id_in_use_on_orconn(test_circ_id, conn));
   return test_circ_id;
 }
 
diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index 7bd3829f62..adb0d7867e 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -661,6 +661,14 @@ circuit_get_by_circid_orconn(uint16_t circ_id, or_connection_t *conn)
     return circ;
 }
 
+/** Return true iff the circuit ID <b>circ_id</b> is currently used by a
+ * circuit, marked or not, on <b>conn</b>. */
+int
+circuit_id_in_use_on_orconn(uint16_t circ_id, or_connection_t *conn)
+{
+  return circuit_get_by_circid_orconn_impl(circ_id, conn) != NULL;
+}
+
 /** Return the circuit that a given edge connection is using. */
 circuit_t *
 circuit_get_by_edge_conn(edge_connection_t *conn)
diff --git a/src/or/command.c b/src/or/command.c
index 552624fb76..f125f47690 100644
--- a/src/or/command.c
+++ b/src/or/command.c
@@ -252,7 +252,7 @@ command_process_create_cell(cell_t *cell, or_connection_t *conn)
     return;
   }
 
-  if (circuit_get_by_circid_orconn(cell->circ_id, conn)) {
+  if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) {
     routerinfo_t *router = router_get_by_digest(conn->identity_digest);
     log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
            "Received CREATE cell (circID %d) for known circ. "
diff --git a/src/or/or.h b/src/or/or.h
index e1a2fe6d9e..6f7d92cabf 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -2568,6 +2568,7 @@ origin_circuit_t *origin_circuit_new(void);
 or_circuit_t *or_circuit_new(uint16_t p_circ_id, or_connection_t *p_conn);
 circuit_t *circuit_get_by_circid_orconn(uint16_t circ_id,
                                         or_connection_t *conn);
+int circuit_id_in_use_on_orconn(uint16_t circ_id, or_connection_t *conn);
 circuit_t *circuit_get_by_edge_conn(edge_connection_t *conn);
 void circuit_unlink_all_from_or_conn(or_connection_t *conn, int reason);
 origin_circuit_t *circuit_get_by_global_id(uint32_t id);