commit d256d4c0a6c6a258c4f6c6839dd53c7e304fa94f Author: Nick Mathewson nickm@torproject.org Date: Fri Sep 29 09:26:16 2017 -0400

Don't package cells onto marked circuits.

This caused a BUG log when we noticed that the circuit had no channel. The likeliest culprit for exposing that behavior is d769cab3e5097980, where we made circuit_mark_for_close() NULL out the n_chan and p_chan fields of the circuit.

Fixes bug 8185; bugfix on 0.2.5.4-alpha, I think. --- changes/bug8185_025 | 6 ++++++ src/or/relay.c | 11 +++++++++++ 2 files changed, 17 insertions(+)

diff --git a/changes/bug8185_025 b/changes/bug8185_025 new file mode 100644 index 000000000..1bfc12b1e --- /dev/null +++ b/changes/bug8185_025 @@ -0,0 +1,6 @@ + o Minor bugfixes (logging, relay shutdown, annoyance): + - When a circuit is marked for close, do not attempt to package any cells + for channels on that circuit. Previously, we would detect this + condition lower in the call stack, when we noticed that the circuit had + no attached channel, and log an annoying message. Fixes bug 8185; + bugfix on 0.2.5.4-alpha. diff --git a/src/or/relay.c b/src/or/relay.c index daf354c34..48c823423 100644 --- a/src/or/relay.c +++ b/src/or/relay.c @@ -390,6 +390,11 @@ circuit_package_relay_cell(cell_t *cell, circuit_t *circ, { channel_t *chan; /* where to send the cell */

+ if (circ->marked_for_close) { + /* Circuit is marked; send nothing. */ + return 0; + } + if (cell_direction == CELL_DIRECTION_OUT) { crypt_path_t *thishop; /* counter for repeated crypts */ chan = circ->n_chan; @@ -703,6 +708,12 @@ connection_edge_send_command(edge_connection_t *fromconn, return -1; }

+ if (circ->marked_for_close) { + /* The circuit has been marked, but not freed yet. When it's freed, it + * will mark this connection for close. */ + return -1; + } + return relay_send_command_from_edge(fromconn->stream_id, circ, relay_command, payload, payload_len, cpath_layer);