From 41fe48585ebd005e65d191452c2860ab9c089c55 Mon Sep 17 00:00:00 2001 From: Lev Stipakov Date: Fri, 9 Aug 2024 21:22:56 +0200 Subject: [PATCH] Use a more robust way to get dco-win version The current way doesn't work if the device is already in use. Starting from 1.3.0, dco-win creates a non-exclusive control device \\.\ovpn-dco-ver which can be opened by multiple apps and supports a single IOCTL to get a version number. https://github.com/OpenVPN/ovpn-dco-win/pull/76 This will be expecially handy later when checking which features driver supports. Change-Id: Ieb6f3a9d14d76000c1caf8ee1e959c6d0de832bf Signed-off-by: Lev Stipakov Acked-by: Gert Doering Message-Id: <20240809192257.24208-1-gert@greenie.muc.de> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg29009.html Signed-off-by: Gert Doering (cherry picked from commit e5a8ea36a0228c30cdbee8791d44a1f0fbaffa9f) --- src/openvpn/dco_win.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/openvpn/dco_win.c b/src/openvpn/dco_win.c index e3ada76a8..3ec946ffb 100644 --- a/src/openvpn/dco_win.c +++ b/src/openvpn/dco_win.c @@ -389,9 +389,16 @@ dco_version_string(struct gc_arena *gc) OVPN_VERSION version; ZeroMemory(&version, sizeof(OVPN_VERSION)); - /* try to open device by symbolic name */ - HANDLE h = CreateFile("\\\\.\\ovpn-dco", GENERIC_READ | GENERIC_WRITE, - 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, NULL); + /* first, try a non-exclusive control device, available from 1.3.0 */ + HANDLE h = CreateFile("\\\\.\\ovpn-dco-ver", GENERIC_READ, + 0, NULL, OPEN_EXISTING, 0, NULL); + + if (h == INVALID_HANDLE_VALUE) + { + /* fallback to a "normal" device, this will fail if device is already in use */ + h = CreateFile("\\\\.\\ovpn-dco", GENERIC_READ, + 0, NULL, OPEN_EXISTING, 0, NULL); + } if (h == INVALID_HANDLE_VALUE) { -- 2.47.3