From e3d0ee0643fdf5edc4f576de99ad70c981349fc3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
 <marmarek@invisiblethingslab.com>
Date: Sun, 31 Mar 2019 14:22:22 +0200
Subject: [PATCH] qrexec: update protocol version negotiation for R4.1

QubesOS/qubes-issues#4909
---
 services/qrexec3.md | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/services/qrexec3.md b/services/qrexec3.md
index c6ff4449..f46227ac 100644
--- a/services/qrexec3.md
+++ b/services/qrexec3.md
@@ -464,11 +464,9 @@ When two peers establish connection, the server sends `MSG_HELLO` followed by
        uint32_t version; /* qrexec protocol version */
     };
 
-The client then should reply with its own `MSG_HELLO` and `peer_info`. If
-protocol versions don't match, the connection is closed.
-
-(*TODO: fallback for backwards compatibility, don't do handshake in the
-same domain?*)
+The client then should reply with its own `MSG_HELLO` and `peer_info`. The
+lower of two versions define protocol used for this connection. If either side
+does not support this version, the connection is closed.
 
 Details of all possible use cases and the messages involved are described below.