[tor-commits] [tor/release-0.3.4] conn: Stop writing when our write bandwidth limist is exhausted

[nickm at torproject.org]

commit 2000d04cb67fa1ee88105e61666dceba40b8c368
Author: David Goulet <dgoulet at torproject.org>
Date:   Wed Oct 17 12:25:12 2018 -0400

    conn: Stop writing when our write bandwidth limist is exhausted
    
    Commit 488e2b00bf881b97bcc8e4bbe304845ff1d79a03 introduced an issue, most
    likely introduced by a bad copy paste, that made us stop reading on the
    connection if our write bandwidth limit was reached.
    
    The problem is that because "read_blocked_on_bw" was never set, the connection
    was never reenabled for reading.
    
    This is most likely the cause of #27813 where bytes were accumulating in the
    kernel TCP bufers because tor was not doing reads. Only relays with
    RelayBandwidthRate would suffer from this but affecting all relays connecting
    to them. And using that tor option is recommended and best practice so many
    many relays have it enabled.
    
    Fixes #28089.
---
 changes/ticket28089 | 6 ++++++
 src/or/connection.c | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/changes/ticket28089 b/changes/ticket28089
new file mode 100644
index 000000000..a900ec18f
--- /dev/null
+++ b/changes/ticket28089
@@ -0,0 +1,6 @@
+  o Major bugfixes (relay):
+    - When our write bandwidth limit is exhausted, stop writing on the
+      connection. Previously, we had a typo in the code that would make us stop
+      reading leading to relay connections being stuck indefinitely. Fixes bug
+      28089; bugfix on 0.3.4.1-alpha.
+
diff --git a/src/or/connection.c b/src/or/connection.c
index 7283a8104..0a2a63509 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -3111,7 +3111,7 @@ connection_write_bw_exhausted(connection_t *conn, bool is_global_bw)
 {
   (void)is_global_bw;
   conn->write_blocked_on_bw = 1;
-  connection_stop_reading(conn);
+  connection_stop_writing(conn);
   reenable_blocked_connection_schedule();
 }