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 "../names.h"
  30 #include "../net.h"
  31 #include "../route.h"
  32 #include "../utils.h"
  33 #include "../xalloc.h"
  34
  35 #include "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 extern char *myport;
  44
  45 static DWORD WINAPI tapreader(void *bla) {
  46         int status;
  47         DWORD len;
  48         OVERLAPPED overlapped;
  49         vpn_packet_t packet;
  50         int errors;
  51
  52         logger(DEBUG_ALWAYS, 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, (void *)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(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
  72                                            device, strerror(errno));
  73                                 errors++;
  74                                 if(errors >= 10) {
  75                                         EnterCriticalSection(&mutex);
  76                                         running = false;
  77                                         LeaveCriticalSection(&mutex);
  78                                 }
  79                                 usleep(1000000);
  80                                 continue;
  81                         }
  82                 }
  83
  84                 errors = 0;
  85                 packet.len = len;
  86                 packet.priority = 0;
  87
  88                 EnterCriticalSection(&mutex);
  89                 route(myself, &packet);
  90                 event_flush_output();
  91                 LeaveCriticalSection(&mutex);
  92         }
  93 }
  94
  95 static bool setup_device(void) {
  96         HKEY key, key2;
  97         int i;
  98
  99         char regpath[1024];
 100         char adapterid[1024];
 101         char adaptername[1024];
 102         char tapname[1024];
 103         DWORD len;
 104         unsigned long status;
 105
 106         bool found = false;
 107
 108         int err;
 109         HANDLE thread;
 110
 111         get_config_string(lookup_config(config_tree, "Device"), &device);
 112         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 113
 114         /* Open registry and look for network adapters */
 115
 116         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 117                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 118                 return false;
 119         }
 120
 121         for (i = 0; ; i++) {
 122                 len = sizeof adapterid;
 123                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 124                         break;
 125
 126                 /* Find out more about this adapter */
 127
 128                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 129
 130                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 131                         continue;
 132
 133                 len = sizeof adaptername;
 134                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 135
 136                 RegCloseKey(key2);
 137
 138                 if(err)
 139                         continue;
 140
 141                 if(device) {
 142                         if(!strcmp(device, adapterid)) {
 143                                 found = true;
 144                                 break;
 145                         } else
 146                                 continue;
 147                 }
 148
 149                 if(iface) {
 150                         if(!strcmp(iface, adaptername)) {
 151                                 found = true;
 152                                 break;
 153                         } else
 154                                 continue;
 155                 }
 156
 157                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 158                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 159                 if(device_handle != INVALID_HANDLE_VALUE) {
 160                         found = true;
 161                         break;
 162                 }
 163         }
 164
 165         RegCloseKey(key);
 166
 167         if(!found) {
 168                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 169                 return false;
 170         }
 171
 172         if(!device)
 173                 device = xstrdup(adapterid);
 174
 175         if(!iface)
 176                 iface = xstrdup(adaptername);
 177
 178         /* Try to open the corresponding tap device */
 179
 180         if(device_handle == INVALID_HANDLE_VALUE) {
 181                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 182                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 183         }
 184
 185         if(device_handle == INVALID_HANDLE_VALUE) {
 186                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 187                 return false;
 188         }
 189
 190         /* Get MAC address from tap device */
 191
 192         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 193                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 194                 return false;
 195         }
 196
 197         if(routing_mode == RMODE_ROUTER) {
 198                 overwrite_mac = 1;
 199         }
 200
 201         /* Start the tap reader */
 202
 203         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 204
 205         if(!thread) {
 206                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 207                 return false;
 208         }
 209
 210         /* Set media status for newer TAP-Win32 devices */
 211
 212         status = true;
 213         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 214
 215         device_info = "Windows tap device";
 216
 217         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 218
 219         return true;
 220 }
 221
 222 static void close_device(void) {
 223         CloseHandle(device_handle);
 224
 225         free(device);
 226         free(iface);
 227 }
 228
 229 static bool read_packet(vpn_packet_t *packet) {
 230         return false;
 231 }
 232
 233 static bool write_packet(vpn_packet_t *packet) {
 234         DWORD outlen;
 235         OVERLAPPED overlapped = {0};
 236
 237         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 238                            packet->len, device_info);
 239
 240         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
 241                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 242                 return false;
 243         }
 244
 245         return true;
 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 };