X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fmingw%2Fdevice.c;h=49b833abbe708f440aaf7af2307e676b22b1ffb2;hp=56203d44939b789efb4c3b5f1f4b2a0d9faac4ff;hb=72bd8dbb86edf54117c5c062cbb93f2bc1f8b729;hpb=68f4ca711593416d0defd81199b176ba604c6cb1

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 56203d44..49b833ab 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -1,7 +1,7 @@
 /*
     device.c -- Interaction with Windows tap driver in a MinGW environment
     Copyright (C) 2002-2005 Ivo Timmermans,
-                  2002-2013 Guus Sliepen <guus@tinc-vpn.org>
+                  2002-2014 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -43,44 +43,55 @@ static uint64_t device_total_in = 0;
 static uint64_t device_total_out = 0;
 
 extern char *myport;
+OVERLAPPED r_overlapped;
+OVERLAPPED w_overlapped;
 
 static DWORD WINAPI tapreader(void *bla) {
 	int status;
 	DWORD len;
-	OVERLAPPED overlapped;
 	vpn_packet_t packet;
+	int errors = 0;
 
 	logger(LOG_DEBUG, "Tap reader running");
 
 	/* Read from tap device and send to parent */
 
-	overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	r_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
 
 	for(;;) {
-		overlapped.Offset = 0;
-		overlapped.OffsetHigh = 0;
-		ResetEvent(overlapped.hEvent);
+		ResetEvent(r_overlapped.hEvent);
 
-		status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
+		status = ReadFile(device_handle, packet.data, MTU, &len, &r_overlapped);
 
 		if(!status) {
 			if(GetLastError() == ERROR_IO_PENDING) {
-				WaitForSingleObject(overlapped.hEvent, INFINITE);
-				if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
+				WaitForSingleObject(r_overlapped.hEvent, INFINITE);
+				if(!GetOverlappedResult(device_handle, &r_overlapped, &len, FALSE))
 					continue;
 			} else {
 				logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
 					   device, strerror(errno));
-				return -1;
+				errors++;
+				if(errors >= 10) {
+					EnterCriticalSection(&mutex);
+					running = false;
+					LeaveCriticalSection(&mutex);
+				}
+				usleep(1000000);
+				continue;
 			}
 		}
 
-		EnterCriticalSection(&mutex);
+		errors = 0;
 		packet.len = len;
 		packet.priority = 0;
+
+		EnterCriticalSection(&mutex);
 		route(myself, &packet);
 		LeaveCriticalSection(&mutex);
 	}
+
+	return 0;
 }
 
 static bool setup_device(void) {
@@ -189,6 +200,11 @@ static bool setup_device(void) {
 		overwrite_mac = 1;
 	}
 
+	/* Create overlapped events for tap I/O */
+
+	r_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	w_overlapped.hEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
+
 	/* Start the tap reader */
 
 	thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
@@ -223,14 +239,48 @@ static bool read_packet(vpn_packet_t *packet) {
 
 static bool write_packet(vpn_packet_t *packet) {
 	DWORD lenout;
-	OVERLAPPED overlapped = {0};
+	static vpn_packet_t queue;
 
 	ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 			   packet->len, device_info);
 
-	if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
-		logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
-		return false;
+	/* Check if there is something in progress */
+
+	if(queue.len) {
+		DWORD size;
+		BOOL success = GetOverlappedResult(device_handle, &w_overlapped, &size, FALSE);
+		if(success) {
+			ResetEvent(&w_overlapped);
+			queue.len = 0;
+		} else {
+			int err = GetLastError();
+			if(err != ERROR_IO_INCOMPLETE) {
+				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error completing previously queued write: %s", winerror(err));
+				ResetEvent(&w_overlapped);
+				queue.len = 0;
+			} else {
+				ifdebug(TRAFFIC) logger(LOG_DEBUG, "Previous overlapped write still in progress");
+				// drop this packet
+				return true;
+			}
+		}
+	}
+
+	/* Otherwise, try to write. */
+
+	memcpy(queue.data, packet->data, packet->len);
+
+	if(!WriteFile(device_handle, queue.data, packet->len, &lenout, &w_overlapped)) {
+		int err = GetLastError();
+		if(err != ERROR_IO_PENDING) {
+			logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(err));
+			return false;
+		}
+		// Write is being done asynchronously.
+		queue.len = packet->len;
+	} else {
+		// Write was completed immediately.
+		ResetEvent(&w_overlapped);
 	}
 
 	device_total_out += packet->len;