From: Etienne Dechamps <etienne@edechamps.fr>
Date: Sat, 19 Jul 2014 17:11:42 +0000 (+0100)
Subject: Handle TAP-Win32 immediate reads correctly.
X-Git-Tag: release-1.1pre11~56
X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=5ae1ec8d80393182b6ff235062b6816b64edfa9b

Handle TAP-Win32 immediate reads correctly.

The handling of TAP-Win32 virtual network device reads that complete
immediately (ReadFile() returns TRUE) is incorrect - instead of
starting a new read, tinc will continue listening for the overlapped
read completion event which will never fire. As a result, tinc stops
receiving packets on the interface.
---

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 2ef00641..6ee26e7b 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -49,11 +49,20 @@ static void device_issue_read() {
 	device_read_overlapped.Offset = 0;
 	device_read_overlapped.OffsetHigh = 0;
 
-	int status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, NULL, &device_read_overlapped);
+	int status;
+	for (;;) {
+		DWORD len;
+		status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped);
+		if (!status) {
+			if (GetLastError() != ERROR_IO_PENDING)
+				logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
+					   device, strerror(errno));
+			break;
+		}
 
-	if(!status && GetLastError() != ERROR_IO_PENDING) {
-		logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
-			   device, strerror(errno));
+		device_read_packet.len = len;
+		device_read_packet.priority = 0;
+		route(myself, &device_read_packet);
 	}
 }