Fix warnings when compiling for Windows.

[tinc] / src / mingw / device.c

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 468ba50..bf8ae13 100644 (file)
--- 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,
-                  2002-2014 Guus Sliepen <guus@tinc-vpn.org>
+                  2002-2018 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
@@ -43,17 +43,16 @@ static vpn_packet_t device_read_packet;
 static vpn_packet_t device_write_packet;
 char *device = NULL;
 char *iface = NULL;
-static char *device_info = NULL;
+static const char *device_info = "Windows tap device";
 
 extern char *myport;
 
 static void device_issue_read() {
-       device_read_overlapped.Offset = 0;
-       device_read_overlapped.OffsetHigh = 0;
-
        int status;
 
        for(;;) {
+               ResetEvent(device_read_overlapped.hEvent);
+
                DWORD len;
                status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped);
 
@@ -72,13 +71,20 @@ static void device_issue_read() {
 }
 
 static void device_handle_read(void *data, int flags) {
-       ResetEvent(device_read_overlapped.hEvent);
+       (void)data;
+       (void)flags;
 
        DWORD len;
 
        if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) {
                logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info,
                       device, strerror(errno));
+
+               if(GetLastError() != ERROR_IO_INCOMPLETE) {
+                       /* Must reset event or it will keep firing. */
+                       ResetEvent(device_read_overlapped.hEvent);
+               }
+
                return;
        }
 
@@ -200,7 +206,7 @@ static bool setup_device(void) {
                ULONG info[3] = {0};
                DWORD len;
 
-               if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof(info), &info, sizeof info, &len, NULL)) {
+               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)" : "");
@@ -209,14 +215,14 @@ static bool setup_device(void) {
                        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. "
+                                      "Using these drivers with tinc is not recommended 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)) {
+       if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
                logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
                return false;
        }
@@ -240,7 +246,7 @@ static void enable_device(void) {
 
        ULONG status = 1;
        DWORD len;
-       DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof status, &len, NULL);
+       DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 
        /* We don't use the write event directly, but GetOverlappedResult() does, internally. */
 
@@ -255,7 +261,7 @@ static void disable_device(void) {
 
        ULONG status = 0;
        DWORD len;
-       DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof status, &len, NULL);
+       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,
@@ -297,6 +303,7 @@ static void close_device(void) {
 }
 
 static bool read_packet(vpn_packet_t *packet) {
+       (void)packet;
        return false;
 }
 
@@ -312,9 +319,13 @@ static bool write_packet(vpn_packet_t *packet) {
                   which according to MSDN is a no-no. */
 
                if(!GetOverlappedResult(device_handle, &device_write_overlapped, &outlen, FALSE)) {
-                       int log_level = (GetLastError() == ERROR_IO_INCOMPLETE) ? DEBUG_TRAFFIC : DEBUG_ALWAYS;
-                       logger(log_level, LOG_ERR, "Error while checking previous write to %s %s: %s", device_info, device, winerror(GetLastError()));
-                       return false;
+                       if(GetLastError() != ERROR_IO_INCOMPLETE) {
+                               logger(DEBUG_ALWAYS, LOG_ERR, "Error completing previously queued write to %s %s: %s", device_info, device, winerror(GetLastError()));
+                       } else {
+                               logger(DEBUG_TRAFFIC, LOG_ERR, "Previous overlapped write to %s %s still in progress", device_info, device);
+                               // drop this packet
+                               return true;
+                       }
                }
        }
 
@@ -322,10 +333,14 @@ static bool write_packet(vpn_packet_t *packet) {
 
        memcpy(&device_write_packet, packet, sizeof(*packet));
 
+       ResetEvent(device_write_overlapped.hEvent);
+
        if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped)) {
+               // Write was completed immediately.
                device_write_packet.len = 0;
        } else if(GetLastError() != ERROR_IO_PENDING) {
                logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
+               device_write_packet.len = 0;
                return false;
        }