diff options
Diffstat (limited to 'src/core/or/command.c')
-rw-r--r-- | src/core/or/command.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/src/core/or/command.c b/src/core/or/command.c index 9226309ff7..a8b93dc9a0 100644 --- a/src/core/or/command.c +++ b/src/core/or/command.c @@ -629,19 +629,22 @@ command_process_destroy_cell(cell_t *cell, channel_t *chan) if (!CIRCUIT_IS_ORIGIN(circ) && chan == TO_OR_CIRCUIT(circ)->p_chan && cell->circ_id == TO_OR_CIRCUIT(circ)->p_circ_id) { - /* the destroy came from behind */ + /* The destroy came from behind so nullify its p_chan. Close the circuit + * with a DESTROYED reason so we don't propagate along the path forward the + * reason which could be used as a side channel. */ circuit_set_p_circid_chan(TO_OR_CIRCUIT(circ), 0, NULL); - circuit_mark_for_close(circ, reason|END_CIRC_REASON_FLAG_REMOTE); + circuit_mark_for_close(circ, END_CIRC_REASON_DESTROYED); } else { /* the destroy came from ahead */ circuit_set_n_circid_chan(circ, 0, NULL); if (CIRCUIT_IS_ORIGIN(circ)) { circuit_mark_for_close(circ, reason|END_CIRC_REASON_FLAG_REMOTE); } else { - char payload[1]; - log_debug(LD_OR, "Delivering 'truncated' back."); - payload[0] = (char)reason; - relay_send_command_from_edge(0, circ, RELAY_COMMAND_TRUNCATED, - payload, sizeof(payload), NULL); + /* Close the circuit so we stop queuing cells for it and propagate the + * DESTROY cell down the circuit so relays can stop queuing in-flight + * cells for this circuit which helps with memory pressure. We do NOT + * propagate the remote reason so not to create a side channel. */ + log_debug(LD_OR, "Received DESTROY cell from n_chan, closing circuit."); + circuit_mark_for_close(circ, END_CIRC_REASON_DESTROYED); } } } |