X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fmingw%2Fdevice.c;h=b047615577d76c91c889104d410dfb8f6cf95596;hp=4b821df7378d1d8ad6c813fd0cff5a91c3b31a45;hb=491839a81aba00d4af50b66563cedaac4fa7028c;hpb=95921696a49d1eff058880c90a80efd208de959d

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 4b821df7..b0476155 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -101,6 +101,9 @@ static bool setup_device(void) {
 	get_config_string(lookup_config(config_tree, "Device"), &device);
 	get_config_string(lookup_config(config_tree, "Interface"), &iface);
 
+	if(device && iface)
+		logger(DEBUG_ALWAYS, LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+
 	/* Open registry and look for network adapters */
 
 	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
@@ -177,6 +180,25 @@ static bool setup_device(void) {
 		return false;
 	}
 
+	/* Get version information from tap device */
+
+	{
+		ULONG info[3] = {0};
+		DWORD len;
+		if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof info, &info, sizeof info, &len, NULL))
+			logger(DEBUG_ALWAYS, LOG_WARNING, "Could not get version information from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
+		else {
+			logger(DEBUG_ALWAYS, LOG_INFO, "TAP-Windows driver version: %lu.%lu%s", info[0], info[1], info[2] ? " (DEBUG)" : "");
+
+			/* Warn if using >=9.21. This is because starting from 9.21, TAP-Win32 seems to use a different, less efficient write path. */
+			if(info[0] == 9 && info[1] >= 21)
+				logger(DEBUG_ALWAYS, LOG_WARNING,
+					"You are using the newer (>= 9.0.0.21, NDIS6) series of TAP-Win32 drivers. "
+					"Using these drivers with tinc is not recommanded as it can result in poor performance. "
+					"You might want to revert back to 9.0.0.9 instead.");
+		}
+	}
+
 	/* Get MAC address from tap device */
 
 	if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {