git.meshlink.io Git - meshlink/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                   2002-2013 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 "names.h"
  30 #include "net.h"
  31 #include "route.h"
  32 #include "utils.h"
  33 #include "xalloc.h"
  34
  35 #include "mingw/common.h"
  36
  37 int device_fd = -1;
  38 static HANDLE device_handle = INVALID_HANDLE_VALUE;
  39 char *device = NULL;
  40 char *iface = NULL;
  41 static char *device_info = NULL;
  42
  43 static uint64_t device_total_in = 0;
  44 static uint64_t device_total_out = 0;
  45
  46 extern char *myport;
  47
  48 static DWORD WINAPI tapreader(void *bla) {
  49         int status;
  50         DWORD len;
  51         OVERLAPPED overlapped;
  52         vpn_packet_t packet;
  53
  54         logger(DEBUG_ALWAYS, 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, (void *)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(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
  74                                            device, strerror(errno));
  75                                 return -1;
  76                         }
  77                 }
  78
  79                 EnterCriticalSection(&mutex);
  80                 packet.len = len;
  81                 packet.priority = 0;
  82                 route(myself, &packet);
  83                 LeaveCriticalSection(&mutex);
  84         }
  85 }
  86
  87 static bool setup_device(void) {
  88         HKEY key, key2;
  89         int i;
  90
  91         char regpath[1024];
  92         char adapterid[1024];
  93         char adaptername[1024];
  94         char tapname[1024];
  95         DWORD len;
  96         unsigned long status;
  97
  98         bool found = false;
  99
 100         int err;
 101         HANDLE thread;
 102
 103         get_config_string(lookup_config(config_tree, "Device"), &device);
 104         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 105
 106         /* Open registry and look for network adapters */
 107
 108         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 109                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 110                 return false;
 111         }
 112
 113         for (i = 0; ; i++) {
 114                 len = sizeof adapterid;
 115                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 116                         break;
 117
 118                 /* Find out more about this adapter */
 119
 120                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 121
 122                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 123                         continue;
 124
 125                 len = sizeof adaptername;
 126                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 127
 128                 RegCloseKey(key2);
 129
 130                 if(err)
 131                         continue;
 132
 133                 if(device) {
 134                         if(!strcmp(device, adapterid)) {
 135                                 found = true;
 136                                 break;
 137                         } else
 138                                 continue;
 139                 }
 140
 141                 if(iface) {
 142                         if(!strcmp(iface, adaptername)) {
 143                                 found = true;
 144                                 break;
 145                         } else
 146                                 continue;
 147                 }
 148
 149                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 150                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 151                 if(device_handle != INVALID_HANDLE_VALUE) {
 152                         found = true;
 153                         break;
 154                 }
 155         }
 156
 157         RegCloseKey(key);
 158
 159         if(!found) {
 160                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 161                 return false;
 162         }
 163
 164         if(!device)
 165                 device = xstrdup(adapterid);
 166
 167         if(!iface)
 168                 iface = xstrdup(adaptername);
 169
 170         /* Try to open the corresponding tap device */
 171
 172         if(device_handle == INVALID_HANDLE_VALUE) {
 173                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 174                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 175         }
 176
 177         if(device_handle == INVALID_HANDLE_VALUE) {
 178                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 179                 return false;
 180         }
 181
 182         /* Get MAC address from tap device */
 183
 184         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 185                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 186                 return false;
 187         }
 188
 189         if(routing_mode == RMODE_ROUTER) {
 190                 overwrite_mac = 1;
 191         }
 192
 193         /* Start the tap reader */
 194
 195         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 196
 197         if(!thread) {
 198                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 199                 return false;
 200         }
 201
 202         /* Set media status for newer TAP-Win32 devices */
 203
 204         status = true;
 205         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 206
 207         device_info = "Windows tap device";
 208
 209         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 210
 211         return true;
 212 }
 213
 214 static void close_device(void) {
 215         CloseHandle(device_handle);
 216
 217         free(device);
 218         free(iface);
 219 }
 220
 221 static bool read_packet(vpn_packet_t *packet) {
 222         return false;
 223 }
 224
 225 static bool write_packet(vpn_packet_t *packet) {
 226         DWORD outlen;
 227         OVERLAPPED overlapped = {0};
 228
 229         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 230                            packet->len, device_info);
 231
 232         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
 233                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 234                 return false;
 235         }
 236
 237         device_total_out += packet->len;
 238
 239         return true;
 240 }
 241
 242 static void dump_device_stats(void) {
 243         logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 244         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 245         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 246 }
 247
 248 const devops_t os_devops = {
 249         .setup = setup_device,
 250         .close = close_device,
 251         .read = read_packet,
 252         .write = write_packet,
 253         .dump_stats = dump_device_stats,
 254 };