2 device.c -- Interaction with Windows tap driver in a MinGW environment
3 Copyright (C) 2002-2005 Ivo Timmermans,
4 2002-2016 Guus Sliepen <guus@tinc-vpn.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 #include "../system.h"
27 #include "../device.h"
28 #include "../logger.h"
32 #include "../xalloc.h"
37 static HANDLE device_handle = INVALID_HANDLE_VALUE;
40 static char *device_info = NULL;
42 static uint64_t device_total_in = 0;
43 static uint64_t device_total_out = 0;
46 OVERLAPPED r_overlapped;
47 OVERLAPPED w_overlapped;
49 static DWORD WINAPI tapreader(void *bla) {
55 logger(LOG_DEBUG, "Tap reader running");
57 /* Read from tap device and send to parent */
59 r_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
62 ResetEvent(r_overlapped.hEvent);
64 status = ReadFile(device_handle, packet.data, MTU, &len, &r_overlapped);
67 if(GetLastError() == ERROR_IO_PENDING) {
68 WaitForSingleObject(r_overlapped.hEvent, INFINITE);
70 if(!GetOverlappedResult(device_handle, &r_overlapped, &len, FALSE)) {
74 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
75 device, strerror(errno));
79 EnterCriticalSection(&mutex);
81 LeaveCriticalSection(&mutex);
93 EnterCriticalSection(&mutex);
94 route(myself, &packet);
95 LeaveCriticalSection(&mutex);
101 static bool setup_device(void) {
106 char adapterid[1024];
107 char adaptername[1024];
110 unsigned long status;
117 get_config_string(lookup_config(config_tree, "Device"), &device);
118 get_config_string(lookup_config(config_tree, "Interface"), &iface);
120 if(device && iface) {
121 logger(LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
124 /* Open registry and look for network adapters */
126 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
127 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
132 len = sizeof(adapterid);
134 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL)) {
138 /* Find out more about this adapter */
140 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
142 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2)) {
146 len = sizeof(adaptername);
147 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
156 if(!strcmp(device, adapterid)) {
165 if(!strcmp(iface, adaptername)) {
173 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
174 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
176 if(device_handle != INVALID_HANDLE_VALUE) {
185 logger(LOG_ERR, "No Windows tap device found!");
190 device = xstrdup(adapterid);
194 iface = xstrdup(adaptername);
197 /* Try to open the corresponding tap device */
199 if(device_handle == INVALID_HANDLE_VALUE) {
200 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
201 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
204 if(device_handle == INVALID_HANDLE_VALUE) {
205 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
209 /* Get MAC address from tap device */
211 if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
212 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
216 if(routing_mode == RMODE_ROUTER) {
220 /* Create overlapped events for tap I/O */
222 r_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
223 w_overlapped.hEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
225 /* Start the tap reader */
227 thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
230 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
234 /* Set media status for newer TAP-Win32 devices */
237 DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
239 device_info = "Windows tap device";
241 logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
246 static void close_device(void) {
247 CloseHandle(device_handle);
253 static bool read_packet(vpn_packet_t *packet) {
257 static bool write_packet(vpn_packet_t *packet) {
259 static vpn_packet_t queue;
261 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
262 packet->len, device_info);
264 /* Check if there is something in progress */
268 BOOL success = GetOverlappedResult(device_handle, &w_overlapped, &size, FALSE);
271 ResetEvent(&w_overlapped);
274 int err = GetLastError();
276 if(err != ERROR_IO_INCOMPLETE) {
277 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Error completing previously queued write: %s", winerror(err));
278 ResetEvent(&w_overlapped);
281 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Previous overlapped write still in progress");
288 /* Otherwise, try to write. */
290 memcpy(queue.data, packet->data, packet->len);
292 if(!WriteFile(device_handle, queue.data, packet->len, &lenout, &w_overlapped)) {
293 int err = GetLastError();
295 if(err != ERROR_IO_PENDING) {
296 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(err));
300 // Write is being done asynchronously.
301 queue.len = packet->len;
303 // Write was completed immediately.
304 ResetEvent(&w_overlapped);
307 device_total_out += packet->len;
312 static void dump_device_stats(void) {
313 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
314 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
315 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
318 const devops_t os_devops = {
319 .setup = setup_device,
320 .close = close_device,
322 .write = write_packet,
323 .dump_stats = dump_device_stats,