tor

commit 74c059596527af67f5df38847e86179852bc7005
parent 1d6054f75065214c55d17796cf1587692fbb5cea
Author: George Kadianakis <desnacked@riseup.net>
Date:   Mon,  5 Aug 2019 13:47:07 +0300

Ignore regular cells in padding circuits.

Padding circuits were regular cells that got closed before their padding
machine could finish. This means that they can still receive regular cells from
their past life, but they have no way or reason to answer them anymore. Hence
let's ignore them before they even get to the proper subsystems.

Diffstat:
A
changes/bug30942
 | 
5
+++++
M
src/core/or/relay.c
 | 
11
+++++++++++

2 files changed, 16 insertions(+), 0 deletions(-)
diff --git a/changes/bug30942 b/changes/bug30942
@@ -0,0 +1,4 @@
+  o Minor bugfixes (circuit padding):
+    - Ignore non-padding cells on padding circuits. This addresses various
+      warning messages from subsystems that were not expecting padding
+      circuits. Fixes bug 30942; bugfix on 0.4.1.1-alpha.
+\ No newline at end of file
diff --git a/src/core/or/relay.c b/src/core/or/relay.c
@@ -1663,6 +1663,17 @@ connection_edge_process_relay_cell(cell_t *cell, circuit_t *circ,
       if (circpad_handle_padding_negotiated(circ, cell, layer_hint) == 0)
         circuit_read_valid_data(TO_ORIGIN_CIRCUIT(circ), rh.length);
       return 0;
+  }
+
+  /* If this is a padding circuit we don't need to parse any other commands
+   * than the padding ones. Just drop them to the floor. */
+  if (circ->purpose == CIRCUIT_PURPOSE_C_CIRCUIT_PADDING) {
+    log_info(domain, "Ignored cell (%d) that arrived in padding circuit.",
+             rh.command);
+    return 0;
+  }
+
+  switch (rh.command) {
     case RELAY_COMMAND_BEGIN:
     case RELAY_COMMAND_BEGIN_DIR:
       if (layer_hint &&