diff mbox series

[Openvpn-devel,v1] Use a more robust way to get dco-win version

Message ID 20240809192257.24208-1-gert@greenie.muc.de
State Accepted
Headers show
Series [Openvpn-devel,v1] Use a more robust way to get dco-win version | expand

Commit Message

Gert Doering Aug. 9, 2024, 7:22 p.m. UTC 
From: Lev Stipakov <lev@openvpn.net>

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 <lev@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
---

This change was reviewed on Gerrit and approved by at least one
developer. I request to merge it to master.

Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/723
This mail reflects revision 1 of this Change.

Acked-by according to Gerrit (reflected above):
Gert Doering <gert@greenie.muc.de>

Comments

Gert Doering Aug. 13, 2024, 6:55 a.m. UTC | #1 
Stared at code here and on the driver side, looks very reasonable and
also backward-compatible in both directions.

Not actually tested, just test compiled via GHA.

Your patch has been applied to the master and release/2.6 branch
(long-term compat).

commit e5a8ea36a0228c30cdbee8791d44a1f0fbaffa9f (master)
commit 41fe48585ebd005e65d191452c2860ab9c089c55 (release/2.6)
Author: Lev Stipakov
Date:   Fri Aug 9 21:22:56 2024 +0200

     Use a more robust way to get dco-win version

     Signed-off-by: Lev Stipakov <lev@openvpn.net>
     Acked-by: Gert Doering <gert@greenie.muc.de>
     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 <gert@greenie.muc.de>


--
kind regards,

Gert Doering
diff mbox series

Patch

diff --git a/src/openvpn/dco_win.c b/src/openvpn/dco_win.c
index e3ada76..3ec946f 100644
--- a/src/openvpn/dco_win.c
+++ b/src/openvpn/dco_win.c
@@ -389,9 +389,16 @@ 
     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)
     {