OpenVPN built from "master" fails to start

[Samuli Seppänen]

The openvpn.exe binary does not work at all if built from latest sources in openvpn.git "master" branch. Latest known-good installer is ​ this , where latest commit is e7d1ac82f. Full details are available ​ here .

Due to Windows build fixes using git-bisect is not an option. We need to manually locate the offending commit from this list:

Full list of changes since the known good version:

CommitID	Author	Description	Reverting fixed openvpn.exe?
330baf2	David Sommerseth	autotools ./configure don't like compat.h	No
032f004	David Sommerseth	Fix compilation errors on Linux platforms without SO_MARK	No
edf8bba	David Sommerseth	New Windows build fixes	Untested
a4234e1	David Sommerseth	Enable access() when building in Visual Studio	Untested
ec302f7	David Sommerseth	Move away from openvpn_basename() over to platform provided basename()	Untested
8ee5646	David Sommerseth	Fix a couple of issues in openvpn_execve()	No
9449e6a	Frederic Crozat	Add support to forward console query to systemd	No
6abb6cd	Gert Doering	Fix list-overrun checks in copy_route_[ipv6_]option_list()	No
9140223	Gert Doering	Fix build-up of duplicate IPv6 routes on reconnect.	No
1d5c443	David Sommerseth	Fix compiling with --disable-crypto and/or --disable-ssl	No
e3f1b6a	James Yonan	Allow "tap-win32 dynamic <offset>" to be used in topology subnet mode.	No
8407991	James Yonan	Fixed client issues with DHCP Router option extraction/deletion when using layer 2 with DHCP proxy:	No
ffea644	James Yonan	Added "memstats" option to maintain real-time operating stats in a memory-mapped file.	No
359adbf	James Yonan	Raised D_PID_DEBUG_LOW from level 3 to 4 to reduce replay error verbosity at level 3.	No
870cf16	David Sommerseth	Don't look for 'stdin' file when using --auth-user-pass	No(1)

(1) manual revert was necessary

[Samuli Seppänen]

This issue caused by file access checks in options.c (lines 2627-2628):

  /* Is the file itself accessible? */
  if (!errcode && (type & CHKACC_FILE) && (access (file, mode) != 0) )
      errcode = errno;

Commenting this out fixes the problem.

[Samuli Seppänen]

The above method seems fail when checking --tmp-dir, which, by default is C:\Users\<username>\ AppData? \Local\Temp . Changing --tmp-dir to something else in OpenVPN configuration does not help.

[Samuli Seppänen]

Adding #define access _access right after #define HAVE_ACCESS 1 (in win/config.h.in ) does not help. Still the same failure.

[Samuli Seppänen]

Added some related documentation to the Wiki, in case somebody wants to take a stab at debugging this further:

• Bisecting...
• Debugging on Windows...

[Samuli Seppänen]

From #openvpn-devel chatlogs (13.1.2012):

mattock: looks like it fails on line 2628 in options.c

According to dazo, this should be fixed now.