diff --git a/changes/bug1184 b/changes/bug1184
new file mode 100644
index 0000000000..856cdc644d
--- /dev/null
+++ b/changes/bug1184
@@ -0,0 +1,9 @@
+ o Minor bugfixes:
+ - Never relay a cell for a circuit we have already destroyed.
+ Between marking a circuit as closeable and finally closing it,
+ it may have been possible for a few queued cells to get relayed,
+ even though they would have been immediately dropped by the next
+ OR in the circuit. Fix 1184; bugfix on 0.2.0.1-alpha.
+ - Never queue a cell for a circuit that's already been marked
+ for close.
+
diff --git a/doc/spec/tor-spec.txt b/doc/spec/tor-spec.txt
index 2b1223ba7a..91ad561b8d 100644
--- a/doc/spec/tor-spec.txt
+++ b/doc/spec/tor-spec.txt
@@ -597,6 +597,14 @@ see tor-design.pdf.
cell to the next node in the circuit, and replies to the OP with a
RELAY_TRUNCATED cell.
+ [Note: If an OR receives a TRUNCATE cell and it has any RELAY cells
+ still queued on the circuit for the next node it will drop them
+ without sending them. This is not considered conformant behavior,
+ but it probably won't get fixed until a later version of Tor. Thus,
+ clients SHOULD NOT send a TRUNCATE cell to a node running any current
+ version of Tor if a) they have sent relay cells through that node,
+ and b) they aren't sure whether those cells have been sent on yes.]
+
When an unrecoverable error occurs along one connection in a
circuit, the nodes on either side of the connection should, if they
are able, act as follows: the node closer to the OP should send a
diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c
index c581365f8b..fa800db1a4 100644
--- a/src/or/circuitlist.c
+++ b/src/or/circuitlist.c
@@ -1124,8 +1124,10 @@ _circuit_mark_for_close(circuit_t *circ, int reason, int line,
rend_client_remove_intro_point(ocirc->build_state->chosen_exit,
ocirc->rend_data);
}
- if (circ->n_conn)
+ if (circ->n_conn) {
+ circuit_clear_cell_queue(circ, circ->n_conn);
connection_or_send_destroy(circ->n_circ_id, circ->n_conn, reason);
+ }
if (! CIRCUIT_IS_ORIGIN(circ)) {
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
@@ -1149,8 +1151,10 @@ _circuit_mark_for_close(circuit_t *circ, int reason, int line,
conn->on_circuit = NULL;
}
- if (or_circ->p_conn)
+ if (or_circ->p_conn) {
+ circuit_clear_cell_queue(circ, or_circ->p_conn);
connection_or_send_destroy(or_circ->p_circ_id, or_circ->p_conn, reason);
+ }
} else {
origin_circuit_t *ocirc = TO_ORIGIN_CIRCUIT(circ);
edge_connection_t *conn;
diff --git a/src/or/connection_or.c b/src/or/connection_or.c
index 686037f2de..4d82da63e9 100644
--- a/src/or/connection_or.c
+++ b/src/or/connection_or.c
@@ -1323,10 +1323,6 @@ connection_or_send_destroy(circid_t circ_id, or_connection_t *conn, int reason)
cell.payload[0] = (uint8_t) reason;
log_debug(LD_OR,"Sending destroy (circID %d).", circ_id);
- /* XXXX It's possible that under some circumstances, we want the destroy
- * to take precedence over other data waiting on the circuit's cell queue.
- */
-
connection_or_write_cell_to_buf(&cell, conn);
return 0;
}
diff --git a/src/or/relay.c b/src/or/relay.c
index 935fad9200..a4f7718d90 100644
--- a/src/or/relay.c
+++ b/src/or/relay.c
@@ -1194,6 +1194,7 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
}
if (circ->n_conn) {
uint8_t trunc_reason = *(uint8_t*)(cell->payload + RELAY_HEADER_SIZE);
+ circuit_clear_cell_queue(circ, circ->n_conn);
connection_or_send_destroy(circ->n_circ_id, circ->n_conn,
trunc_reason);
circuit_set_n_circid_orconn(circ, 0, NULL);
@@ -2377,6 +2378,9 @@ append_cell_to_circuit_queue(circuit_t *circ, or_connection_t *orconn,
{
cell_queue_t *queue;
int streams_blocked;
+ if (circ->marked_for_close)
+ return;
+
if (direction == CELL_DIRECTION_OUT) {
queue = &circ->n_conn_cells;
streams_blocked = circ->streams_blocked_on_n_conn;
@@ -2479,6 +2483,25 @@ decode_address_from_payload(tor_addr_t *addr_out, const char *payload,
return payload + 2 + (uint8_t)payload[1];
}
+/** Remove all the cells queued on circ for orconn. */
+void
+circuit_clear_cell_queue(circuit_t *circ, or_connection_t *orconn)
+{
+ cell_queue_t *queue;
+ if (circ->n_conn == orconn) {
+ queue = &circ->n_conn_cells;
+ } else {
+ or_circuit_t *orcirc = TO_OR_CIRCUIT(circ);
+ tor_assert(orcirc->p_conn == orconn);
+ queue = &orcirc->p_conn_cells;
+ }
+
+ if (queue->n)
+ make_circuit_inactive_on_conn(circ,orconn);
+
+ cell_queue_clear(queue);
+}
+
/** Fail with an assert if the active circuits ring on orconn is
* corrupt. */
void
diff --git a/src/or/relay.h b/src/or/relay.h
index 66d17579a3..08a1ffe789 100644
--- a/src/or/relay.h
+++ b/src/or/relay.h
@@ -62,6 +62,7 @@ const char *decode_address_from_payload(tor_addr_t *addr_out,
unsigned cell_ewma_get_tick(void);
void cell_ewma_set_scale_factor(or_options_t *options,
networkstatus_t *consensus);
+void circuit_clear_cell_queue(circuit_t *circ, or_connection_t *orconn);
#endif