From: Roger Dingledine <arma@torproject.org>
Date: Tue, 16 Jan 2018 03:33:40 +0000 (-0500)
Subject: Remove false positives from channel_is_client()
X-Git-Tag: tor-0.3.1.10~25^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=af8cadf3a9febe3dbe22899b828f9f7946a82cef;p=thirdparty%2Ftor.git

Remove false positives from channel_is_client()

Fix a set of false positives where relays would consider connections
to other relays as being client-only connections (and thus e.g.
deserving different link padding schemes) if those relays fell out
of the consensus briefly.

Now we look only at the initial handshake and whether the connection
authenticated as a relay.

Fixes bug 24898; bugfix on 0.3.1.1-alpha.
---

diff --git a/changes/bug24898 b/changes/bug24898
new file mode 100644
index 0000000000..f64340d71b
--- /dev/null
+++ b/changes/bug24898
@@ -0,0 +1,8 @@
+  o Major bugfixes (relays):
+    - Fix a set of false positives where relays would consider connections
+      to other relays as being client-only connections (and thus e.g.
+      deserving different link padding schemes) if those relays fell out
+      of the consensus briefly. Now we look only at the initial handshake
+      and whether the connection authenticated as a relay. Fixes bug
+      24898; bugfix on 0.3.1.1-alpha.
+
diff --git a/src/or/command.c b/src/or/command.c
index c667cbbe52..894483e001 100644
--- a/src/or/command.c
+++ b/src/or/command.c
@@ -328,12 +328,6 @@ command_process_create_cell(cell_t *cell, channel_t *chan)
 
   if (connection_or_digest_is_known_relay(chan->identity_digest)) {
     rep_hist_note_circuit_handshake_requested(create_cell->handshake_type);
-    // Needed for chutney: Sometimes relays aren't in the consensus yet, and
-    // get marked as clients. This resets their channels once they appear.
-    // Probably useful for normal operation wrt relay flapping, too.
-    chan->is_client = 0;
-  } else {
-    channel_mark_client(chan);
   }
 
   if (create_cell->handshake_type != ONION_HANDSHAKE_TYPE_FAST) {
diff --git a/src/or/connection_or.c b/src/or/connection_or.c
index 59a9bdffda..fcd281da26 100644
--- a/src/or/connection_or.c
+++ b/src/or/connection_or.c
@@ -1952,6 +1952,12 @@ connection_or_set_state_open(or_connection_t *conn)
   connection_or_change_state(conn, OR_CONN_STATE_OPEN);
   control_event_or_conn_status(conn, OR_CONN_EVENT_CONNECTED, 0);
 
+  /* Link protocol 3 appeared in Tor 0.2.3.6-alpha, so any connection
+   * that uses an earlier link protocol should not be treated as a relay. */
+  if (conn->link_proto < 3) {
+    channel_mark_client(TLS_CHAN_TO_BASE(conn->chan));
+  }
+
   or_handshake_state_free(conn->handshake_state);
   conn->handshake_state = NULL;
   connection_start_reading(TO_CONN(conn));