git.meshlink.io Git - meshlink/blob - mingw/device.c

   1 /*
   2     device.c -- Interaction with Windows tap driver in a MinGW environment
   3     Copyright (C) 2002-2005 Ivo Timmermans,
   4                   2002-2011 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 "logger.h"
  28 #include "net.h"
  29 #include "route.h"
  30 #include "utils.h"
  31 #include "xalloc.h"
  32
  33 #include "mingw/common.h"
  34
  35 int device_fd = -1;
  36 static HANDLE device_handle = INVALID_HANDLE_VALUE;
  37 char *device = NULL;
  38 char *iface = NULL;
  39 static char *device_info = NULL;
  40
  41 static uint64_t device_total_in = 0;
  42 static uint64_t device_total_out = 0;
  43
  44 extern char *myport;
  45
  46 static DWORD WINAPI tapreader(void *bla) {
  47         int status;
  48         long len;
  49         OVERLAPPED overlapped;
  50         vpn_packet_t packet;
  51
  52         logger(LOG_DEBUG, "Tap reader running");
  53
  54         /* Read from tap device and send to parent */
  55
  56         overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
  57
  58         for(;;) {
  59                 overlapped.Offset = 0;
  60                 overlapped.OffsetHigh = 0;
  61                 ResetEvent(overlapped.hEvent);
  62
  63                 status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
  64
  65                 if(!status) {
  66                         if(GetLastError() == ERROR_IO_PENDING) {
  67                                 WaitForSingleObject(overlapped.hEvent, INFINITE);
  68                                 if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
  69                                         continue;
  70                         } else {
  71                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
  72                                            device, strerror(errno));
  73                                 return -1;
  74                         }
  75                 }
  76
  77                 EnterCriticalSection(&mutex);
  78                 packet.len = len;
  79                 packet.priority = 0;
  80                 route(myself, &packet);
  81                 LeaveCriticalSection(&mutex);
  82         }
  83 }
  84
  85 bool setup_device(void) {
  86         HKEY key, key2;
  87         int i;
  88
  89         char regpath[1024];
  90         char adapterid[1024];
  91         char adaptername[1024];
  92         char tapname[1024];
  93         long len;
  94         unsigned long status;
  95
  96         bool found = false;
  97
  98         int err;
  99         HANDLE thread;
 100
 101         get_config_string(lookup_config(config_tree, "Device"), &device);
 102         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 103
 104         /* Open registry and look for network adapters */
 105
 106         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 107                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 108                 return false;
 109         }
 110
 111         for (i = 0; ; i++) {
 112                 len = sizeof adapterid;
 113                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 114                         break;
 115
 116                 /* Find out more about this adapter */
 117
 118                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 119
 120                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 121                         continue;
 122
 123                 len = sizeof adaptername;
 124                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
 125
 126                 RegCloseKey(key2);
 127
 128                 if(err)
 129                         continue;
 130
 131                 if(device) {
 132                         if(!strcmp(device, adapterid)) {
 133                                 found = true;
 134                                 break;
 135                         } else
 136                                 continue;
 137                 }
 138
 139                 if(iface) {
 140                         if(!strcmp(iface, adaptername)) {
 141                                 found = true;
 142                                 break;
 143                         } else
 144                                 continue;
 145                 }
 146
 147                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 148                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 149                 if(device_handle != INVALID_HANDLE_VALUE) {
 150                         found = true;
 151                         break;
 152                 }
 153         }
 154
 155         RegCloseKey(key);
 156
 157         if(!found) {
 158                 logger(LOG_ERR, "No Windows tap device found!");
 159                 return false;
 160         }
 161
 162         if(!device)
 163                 device = xstrdup(adapterid);
 164
 165         if(!iface)
 166                 iface = xstrdup(adaptername);
 167
 168         /* Try to open the corresponding tap device */
 169
 170         if(device_handle == INVALID_HANDLE_VALUE) {
 171                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 172                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 173         }
 174
 175         if(device_handle == INVALID_HANDLE_VALUE) {
 176                 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 177                 return false;
 178         }
 179
 180         /* Get MAC address from tap device */
 181
 182         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 183                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 184                 return false;
 185         }
 186
 187         if(routing_mode == RMODE_ROUTER) {
 188                 overwrite_mac = 1;
 189         }
 190
 191         /* Start the tap reader */
 192
 193         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 194
 195         if(!thread) {
 196                 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 197                 return false;
 198         }
 199
 200         /* Set media status for newer TAP-Win32 devices */
 201
 202         status = true;
 203         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 204
 205         device_info = "Windows tap device";
 206
 207         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 208
 209         return true;
 210 }
 211
 212 void close_device(void) {
 213         CloseHandle(device_handle);
 214
 215         free(device);
 216         free(iface);
 217 }
 218
 219 bool read_packet(vpn_packet_t *packet) {
 220         return false;
 221 }
 222
 223 bool write_packet(vpn_packet_t *packet) {
 224         long outlen;
 225         OVERLAPPED overlapped = {0};
 226
 227         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 228                            packet->len, device_info);
 229
 230         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
 231                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 232                 return false;
 233         }
 234
 235         device_total_out += packet->len;
 236
 237         return true;
 238 }
 239
 240 void dump_device_stats(void) {
 241         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 242         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 243         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 244 }