www.tinc-vpn.org Git - tinc/blob - src/mingw/device.c

   1 /*
   2     device.c -- Interaction with Windows tap driver in a MinGW environment
   3     Copyright (C) 2002-2005 Ivo Timmermans,
   4                   2002-2014 Guus Sliepen <guus@tinc-vpn.org>
   5
   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.
  10
  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.
  15
  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.
  19 */
  20
  21 #include "../system.h"
  22
  23 #include <windows.h>
  24 #include <winioctl.h>
  25
  26 #include "../conf.h"
  27 #include "../device.h"
  28 #include "../logger.h"
  29 #include "../net.h"
  30 #include "../route.h"
  31 #include "../utils.h"
  32 #include "../xalloc.h"
  33
  34 #include "common.h"
  35
  36 int device_fd = -1;
  37 static HANDLE device_handle = INVALID_HANDLE_VALUE;
  38 char *device = NULL;
  39 char *iface = NULL;
  40 static char *device_info = NULL;
  41
  42 static uint64_t device_total_in = 0;
  43 static uint64_t device_total_out = 0;
  44
  45 extern char *myport;
  46
  47 static DWORD WINAPI tapreader(void *bla) {
  48         int status;
  49         DWORD len;
  50         OVERLAPPED overlapped;
  51         vpn_packet_t packet;
  52         int errors = 0;
  53
  54         logger(LOG_DEBUG, "Tap reader running");
  55
  56         /* Read from tap device and send to parent */
  57
  58         overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
  59
  60         for(;;) {
  61                 overlapped.Offset = 0;
  62                 overlapped.OffsetHigh = 0;
  63                 ResetEvent(overlapped.hEvent);
  64
  65                 status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
  66
  67                 if(!status) {
  68                         if(GetLastError() == ERROR_IO_PENDING) {
  69                                 WaitForSingleObject(overlapped.hEvent, INFINITE);
  70                                 if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
  71                                         continue;
  72                         } else {
  73                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
  74                                            device, strerror(errno));
  75                                 errors++;
  76                                 if(errors >= 10) {
  77                                         EnterCriticalSection(&mutex);
  78                                         running = false;
  79                                         LeaveCriticalSection(&mutex);
  80                                 }
  81                                 usleep(1000000);
  82                                 continue;
  83                         }
  84                 }
  85
  86                 errors = 0;
  87                 packet.len = len;
  88                 packet.priority = 0;
  89
  90                 EnterCriticalSection(&mutex);
  91                 route(myself, &packet);
  92                 LeaveCriticalSection(&mutex);
  93         }
  94
  95         return 0;
  96 }
  97
  98 static bool setup_device(void) {
  99         HKEY key, key2;
 100         int i;
 101
 102         char regpath[1024];
 103         char adapterid[1024];
 104         char adaptername[1024];
 105         char tapname[1024];
 106         DWORD len;
 107         unsigned long status;
 108
 109         bool found = false;
 110
 111         int err;
 112         HANDLE thread;
 113
 114         get_config_string(lookup_config(config_tree, "Device"), &device);
 115         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 116
 117         /* Open registry and look for network adapters */
 118
 119         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 120                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 121                 return false;
 122         }
 123
 124         for (i = 0; ; i++) {
 125                 len = sizeof(adapterid);
 126                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 127                         break;
 128
 129                 /* Find out more about this adapter */
 130
 131                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 132
 133                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 134                         continue;
 135
 136                 len = sizeof(adaptername);
 137                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 138
 139                 RegCloseKey(key2);
 140
 141                 if(err)
 142                         continue;
 143
 144                 if(device) {
 145                         if(!strcmp(device, adapterid)) {
 146                                 found = true;
 147                                 break;
 148                         } else
 149                                 continue;
 150                 }
 151
 152                 if(iface) {
 153                         if(!strcmp(iface, adaptername)) {
 154                                 found = true;
 155                                 break;
 156                         } else
 157                                 continue;
 158                 }
 159
 160                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 161                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 162                 if(device_handle != INVALID_HANDLE_VALUE) {
 163                         found = true;
 164                         break;
 165                 }
 166         }
 167
 168         RegCloseKey(key);
 169
 170         if(!found) {
 171                 logger(LOG_ERR, "No Windows tap device found!");
 172                 return false;
 173         }
 174
 175         if(!device)
 176                 device = xstrdup(adapterid);
 177
 178         if(!iface)
 179                 iface = xstrdup(adaptername);
 180
 181         /* Try to open the corresponding tap device */
 182
 183         if(device_handle == INVALID_HANDLE_VALUE) {
 184                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 185                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 186         }
 187
 188         if(device_handle == INVALID_HANDLE_VALUE) {
 189                 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 190                 return false;
 191         }
 192
 193         /* Get MAC address from tap device */
 194
 195         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
 196                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 197                 return false;
 198         }
 199
 200         if(routing_mode == RMODE_ROUTER) {
 201                 overwrite_mac = 1;
 202         }
 203
 204         /* Start the tap reader */
 205
 206         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 207
 208         if(!thread) {
 209                 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 210                 return false;
 211         }
 212
 213         /* Set media status for newer TAP-Win32 devices */
 214
 215         status = true;
 216         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 217
 218         device_info = "Windows tap device";
 219
 220         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 221
 222         return true;
 223 }
 224
 225 static void close_device(void) {
 226         CloseHandle(device_handle);
 227
 228         free(device);
 229         free(iface);
 230 }
 231
 232 static bool read_packet(vpn_packet_t *packet) {
 233         return false;
 234 }
 235
 236 static bool write_packet(vpn_packet_t *packet) {
 237         DWORD lenout;
 238         OVERLAPPED overlapped = {0};
 239
 240         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 241                            packet->len, device_info);
 242
 243         if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
 244                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 245                 return false;
 246         }
 247
 248         device_total_out += packet->len;
 249
 250         return true;
 251 }
 252
 253 static void dump_device_stats(void) {
 254         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 255         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 256         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 257 }
 258
 259 const devops_t os_devops = {
 260         .setup = setup_device,
 261         .close = close_device,
 262         .read = read_packet,
 263         .write = write_packet,
 264         .dump_stats = dump_device_stats,
 265 };