Do not restart dns client service as a part of --register-dns processing

As reported and discussed on Trac #775, restarting dns service has
unwanted side effects when there are dependent services. And it
appears unnecessary to restart this service to get DNS registered
on Windows.

Resolve by removing two actions from --register-dns:
'net stop dnscache' and 'net start dnscache' run through the service
or directly.

Trac: #775

Signed-off-by: Selva Nair <selva.nair@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1480542696-7123-1-git-send-email-selva.nair@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg13331.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/Changes.rst b/Changes.rst
index 1343034e1bf92d24b9fc1d4a526e904be23534ae..abd725862532c37fa5dec7534add93cded7a752a 100644 (file)
--- a/Changes.rst
+++ b/Changes.rst
@@ -251,6 +251,10 @@ User-visible Changes
   as the VPN server, are dropped. This could be disabled with
   --allow-recursive-routing option.
 
+- on Windows, when the ``--register-dns`` option is set, OpenVPN no longer
+  restarts the ``dnscache`` service - this had unwanted side effects, and
+  seems to be no longer necessary with currently supported Windows versions.
+
 Maintainer-visible changes
 --------------------------
 - OpenVPN no longer supports building with crypto support, but without TLS

diff --git a/doc/openvpn.8 b/doc/openvpn.8
index dd09c703e7d6e685f5b97eaa2d11161322e68711..e61b6bbcd73483b4a5d11c4525ff4e811b03585e 100644 (file)
--- a/doc/openvpn.8
+++ b/doc/openvpn.8
@@ -5811,8 +5811,7 @@ above.
 .\"*********************************************************
 .TP
 .B \-\-register\-dns
-Run net stop dnscache, net start dnscache, ipconfig /flushdns
-and ipconfig /registerdns on connection initiation.
+Run ipconfig /flushdns and ipconfig /registerdns on connection initiation.
 This is known to kick Windows into
 recognizing pushed DNS servers.
 .\"*********************************************************

diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index 038fcd3820d9ae30d5bcd250c9d3e672e26e684c..47acd97c45891949ab12ced633eeb8c0d7bca656 100644 (file)
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -717,8 +717,8 @@ static const char usage_message[] =
   "--dhcp-pre-release : Ask Windows to release the previous TAP adapter lease on\n"
 "                       startup.\n"
   "--dhcp-release     : Ask Windows to release the TAP adapter lease on shutdown.\n"
-  "--register-dns  : Run net stop dnscache, net start dnscache, ipconfig /flushdns\n"
-  "                  and ipconfig /registerdns on connection initiation.\n"
+  "--register-dns  : Run ipconfig /flushdns and ipconfig /registerdns\n"
+  "                  on connection initiation.\n"
   "--tap-sleep n   : Sleep for n seconds after TAP adapter open before\n"
   "                  attempting to set adapter properties.\n"
   "--pause-exit         : When run from a console window, pause before exiting.\n"

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 560b1a8e153cb1a46b8462768c09aab487944e9c..572e168b153eb363aef812c664cf38f827116830 100644 (file)
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -4597,23 +4597,9 @@ ipconfig_register_dns (const struct env_set *es)
   bool status;
   const char err[] = "ERROR: Windows ipconfig command failed";
 
-  msg (D_TUNTAP_INFO, "Start net commands...");
+  msg (D_TUNTAP_INFO, "Start ipconfig commands for register-dns...");
   netcmd_semaphore_lock ();
 
-  argv_printf (&argv, "%s%sc stop dnscache",
-              get_win_sys_path(),
-              WIN_NET_PATH_SUFFIX);
-  argv_msg (D_TUNTAP_INFO, &argv);
-  status = openvpn_execve_check (&argv, es, 0, err);
-  argv_reset(&argv);
-
-  argv_printf (&argv, "%s%sc start dnscache",
-              get_win_sys_path(),
-              WIN_NET_PATH_SUFFIX);
-  argv_msg (D_TUNTAP_INFO, &argv);
-  status = openvpn_execve_check (&argv, es, 0, err);
-  argv_reset(&argv);
-
   argv_printf (&argv, "%s%sc /flushdns",
               get_win_sys_path(),
               WIN_IPCONFIG_PATH_SUFFIX);
@@ -4629,7 +4615,7 @@ ipconfig_register_dns (const struct env_set *es)
   argv_reset(&argv);
 
   netcmd_semaphore_release ();
-  msg (D_TUNTAP_INFO, "End net commands...");
+  msg (D_TUNTAP_INFO, "End ipconfig commands for register-dns...");
 }
 
 void

diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index 608bb0c3778b93e7f0dbb944fe6e1210143b52b7..ec54216bb44bd6c8f25639c4281801472ed1f761 100644 (file)
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -899,8 +899,7 @@ RegisterDNS (LPVOID unused)
   WCHAR sys_path[MAX_PATH];
   DWORD timeout = RDNS_TIMEOUT * 1000; /* in milliseconds */
 
-  /* default paths of net and ipconfig commands */
-  WCHAR net[MAX_PATH]   = L"C:\\Windows\\system32\\net.exe";
+  /* default path of ipconfig command */
   WCHAR ipcfg[MAX_PATH] = L"C:\\Windows\\system32\\ipconfig.exe";
 
   struct
@@ -909,8 +908,6 @@ RegisterDNS (LPVOID unused)
       WCHAR *cmdline;
       DWORD timeout;
     } cmds [] = {
-                  { net,   L"net stop dnscache",     timeout },
-                  { net,   L"net start dnscache",    timeout },
                   { ipcfg, L"ipconfig /flushdns",    timeout },
                   { ipcfg, L"ipconfig /registerdns", timeout },
                 };
@@ -920,9 +917,6 @@ RegisterDNS (LPVOID unused)
 
   if(GetSystemDirectory(sys_path, MAX_PATH))
     {
-      _snwprintf (net, MAX_PATH, L"%s\\%s", sys_path, L"net.exe");
-      net[MAX_PATH-1] = L'\0';
-
       _snwprintf (ipcfg, MAX_PATH, L"%s\\%s", sys_path, L"ipconfig.exe");
       ipcfg[MAX_PATH-1] = L'\0';
     }