git.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                   2002-2013 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 "../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;
  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
  96 static bool setup_device(void) {
  97         HKEY key, key2;
  98         int i;
  99
 100         char regpath[1024];
 101         char adapterid[1024];
 102         char adaptername[1024];
 103         char tapname[1024];
 104         DWORD len;
 105         unsigned long status;
 106
 107         bool found = false;
 108
 109         int err;
 110         HANDLE thread;
 111
 112         get_config_string(lookup_config(config_tree, "Device"), &device);
 113         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 114
 115         /* Open registry and look for network adapters */
 116
 117         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 118                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 119                 return false;
 120         }
 121
 122         for (i = 0; ; i++) {
 123                 len = sizeof(adapterid);
 124                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 125                         break;
 126
 127                 /* Find out more about this adapter */
 128
 129                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 130
 131                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 132                         continue;
 133
 134                 len = sizeof(adaptername);
 135                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 136
 137                 RegCloseKey(key2);
 138
 139                 if(err)
 140                         continue;
 141
 142                 if(device) {
 143                         if(!strcmp(device, adapterid)) {
 144                                 found = true;
 145                                 break;
 146                         } else
 147                                 continue;
 148                 }
 149
 150                 if(iface) {
 151                         if(!strcmp(iface, adaptername)) {
 152                                 found = true;
 153                                 break;
 154                         } else
 155                                 continue;
 156                 }
 157
 158                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 159                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 160                 if(device_handle != INVALID_HANDLE_VALUE) {
 161                         found = true;
 162                         break;
 163                 }
 164         }
 165
 166         RegCloseKey(key);
 167
 168         if(!found) {
 169                 logger(LOG_ERR, "No Windows tap device found!");
 170                 return false;
 171         }
 172
 173         if(!device)
 174                 device = xstrdup(adapterid);
 175
 176         if(!iface)
 177                 iface = xstrdup(adaptername);
 178
 179         /* Try to open the corresponding tap device */
 180
 181         if(device_handle == INVALID_HANDLE_VALUE) {
 182                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 183                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 184         }
 185
 186         if(device_handle == INVALID_HANDLE_VALUE) {
 187                 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 188                 return false;
 189         }
 190
 191         /* Get MAC address from tap device */
 192
 193         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
 194                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 195                 return false;
 196         }
 197
 198         if(routing_mode == RMODE_ROUTER) {
 199                 overwrite_mac = 1;
 200         }
 201
 202         /* Start the tap reader */
 203
 204         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 205
 206         if(!thread) {
 207                 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 208                 return false;
 209         }
 210
 211         /* Set media status for newer TAP-Win32 devices */
 212
 213         status = true;
 214         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 215
 216         device_info = "Windows tap device";
 217
 218         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 219
 220         return true;
 221 }
 222
 223 static void close_device(void) {
 224         CloseHandle(device_handle);
 225
 226         free(device);
 227         free(iface);
 228 }
 229
 230 static bool read_packet(vpn_packet_t *packet) {
 231         return false;
 232 }
 233
 234 static bool write_packet(vpn_packet_t *packet) {
 235         DWORD lenout;
 236         OVERLAPPED overlapped = {0};
 237
 238         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 239                            packet->len, device_info);
 240
 241         if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
 242                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 243                 return false;
 244         }
 245
 246         device_total_out += packet->len;
 247
 248         return true;
 249 }
 250
 251 static void dump_device_stats(void) {
 252         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 253         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 254         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 255 }
 256
 257 const devops_t os_devops = {
 258         .setup = setup_device,
 259         .close = close_device,
 260         .read = read_packet,
 261         .write = write_packet,
 262         .dump_stats = dump_device_stats,
 263 };