From: Guus Sliepen <guus@tinc-vpn.org>
Date: Mon, 20 Mar 2017 21:33:18 +0000 (+0100)
Subject: Merge remote-tracking branch 'dechamps/sleep' into 1.1
X-Git-Tag: release-1.1pre15~40
X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=aebaaa8db80ec3931346af710f2182d129c74c41;hp=2c333f0f45f445d0811a364817d03df0c8cf2d2f

Merge remote-tracking branch 'dechamps/sleep' into 1.1
---

diff --git a/src/event.c b/src/event.c
index 59b96e37..858e1d9d 100644
--- a/src/event.c
+++ b/src/event.c
@@ -357,10 +357,13 @@ bool event_loop(void) {
 			WSANETWORKEVENTS network_events;
 			if (WSAEnumNetworkEvents(io->fd, io->event, &network_events) != 0)
 				return false;
-			if (network_events.lNetworkEvents & WRITE_EVENTS)
-				io->cb(io->data, IO_WRITE);
 			if (network_events.lNetworkEvents & READ_EVENTS)
 				io->cb(io->data, IO_READ);
+			/*
+			    The fd might be available for write too. However, if we already fired the read callback, that
+			    callback might have deleted the io (e.g. through terminate_connection()), so we can't fire the
+			    write callback here. Instead, we loop back and let the writable io loop above handle it.
+			 */
 		}
 	}
 #endif
diff --git a/src/mingw/device.c b/src/mingw/device.c
index b0476155..dfdb9641 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -214,6 +214,9 @@ static bool setup_device(void) {
 
 	logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 
+	device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+
 	return true;
 }
 
@@ -226,9 +229,6 @@ static void enable_device(void) {
 
 	/* We don't use the write event directly, but GetOverlappedResult() does, internally. */
 
-	device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-	device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-
 	io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent);
 	device_issue_read();
 }
@@ -237,6 +237,19 @@ static void disable_device(void) {
 	logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
 
 	io_del(&device_read_io);
+
+	ULONG status = 0;
+	DWORD len;
+	DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
+
+	/* Note that we don't try to cancel ongoing I/O here - we just stop listening.
+	   This is because some TAP-Win32 drivers don't seem to handle cancellation very well,
+	   especially when combined with other events such as the computer going to sleep - cases
+	   were observed where the GetOverlappedResult() would just block indefinitely and never
+	   return in that case. */
+}
+
+static void close_device(void) {
 	CancelIo(device_handle);
 
 	/* According to MSDN, CancelIo() does not necessarily wait for the operation to complete.
@@ -253,11 +266,6 @@ static void disable_device(void) {
 	CloseHandle(device_read_overlapped.hEvent);
 	CloseHandle(device_write_overlapped.hEvent);
 
-	ULONG status = 0;
-	DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
-}
-
-static void close_device(void) {
 	CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 
 	free(device); device = NULL;