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                   2002-2011 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 "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 "mingw/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         long len;
  50         OVERLAPPED overlapped;
  51         vpn_packet_t packet;
  52
  53         logger(LOG_DEBUG, "Tap reader running");
  54
  55         /* Read from tap device and send to parent */
  56
  57         overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
  58
  59         for(;;) {
  60                 overlapped.Offset = 0;
  61                 overlapped.OffsetHigh = 0;
  62                 ResetEvent(overlapped.hEvent);
  63
  64                 status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
  65
  66                 if(!status) {
  67                         if(GetLastError() == ERROR_IO_PENDING) {
  68                                 WaitForSingleObject(overlapped.hEvent, INFINITE);
  69                                 if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
  70                                         continue;
  71                         } else {
  72                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
  73                                            device, strerror(errno));
  74                                 return -1;
  75                         }
  76                 }
  77
  78                 EnterCriticalSection(&mutex);
  79                 packet.len = len;
  80                 packet.priority = 0;
  81                 route(myself, &packet);
  82                 LeaveCriticalSection(&mutex);
  83         }
  84 }
  85
  86 bool setup_device(void) {
  87         HKEY key, key2;
  88         int i;
  89
  90         char regpath[1024];
  91         char adapterid[1024];
  92         char adaptername[1024];
  93         char tapname[1024];
  94         long len;
  95         unsigned long status;
  96
  97         bool found = false;
  98
  99         int err;
 100         HANDLE thread;
 101
 102         get_config_string(lookup_config(config_tree, "Device"), &device);
 103         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 104
 105         /* Open registry and look for network adapters */
 106
 107         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 108                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 109                 return false;
 110         }
 111
 112         for (i = 0; ; i++) {
 113                 len = sizeof(adapterid);
 114                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 115                         break;
 116
 117                 /* Find out more about this adapter */
 118
 119                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 120
 121                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 122                         continue;
 123
 124                 len = sizeof(adaptername);
 125                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
 126
 127                 RegCloseKey(key2);
 128
 129                 if(err)
 130                         continue;
 131
 132                 if(device) {
 133                         if(!strcmp(device, adapterid)) {
 134                                 found = true;
 135                                 break;
 136                         } else
 137                                 continue;
 138                 }
 139
 140                 if(iface) {
 141                         if(!strcmp(iface, adaptername)) {
 142                                 found = true;
 143                                 break;
 144                         } else
 145                                 continue;
 146                 }
 147
 148                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 149                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 150                 if(device_handle != INVALID_HANDLE_VALUE) {
 151                         found = true;
 152                         break;
 153                 }
 154         }
 155
 156         RegCloseKey(key);
 157
 158         if(!found) {
 159                 logger(LOG_ERR, "No Windows tap device found!");
 160                 return false;
 161         }
 162
 163         if(!device)
 164                 device = xstrdup(adapterid);
 165
 166         if(!iface)
 167                 iface = xstrdup(adaptername);
 168
 169         /* Try to open the corresponding tap device */
 170
 171         if(device_handle == INVALID_HANDLE_VALUE) {
 172                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 173                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 174         }
 175
 176         if(device_handle == INVALID_HANDLE_VALUE) {
 177                 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 178                 return false;
 179         }
 180
 181         /* Get MAC address from tap device */
 182
 183         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
 184                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 185                 return false;
 186         }
 187
 188         if(routing_mode == RMODE_ROUTER) {
 189                 overwrite_mac = 1;
 190         }
 191
 192         /* Start the tap reader */
 193
 194         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 195
 196         if(!thread) {
 197                 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 198                 return false;
 199         }
 200
 201         /* Set media status for newer TAP-Win32 devices */
 202
 203         status = true;
 204         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 205
 206         device_info = "Windows tap device";
 207
 208         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 209
 210         return true;
 211 }
 212
 213 void close_device(void) {
 214         CloseHandle(device_handle);
 215
 216         free(device);
 217         free(iface);
 218 }
 219
 220 bool read_packet(vpn_packet_t *packet) {
 221         return false;
 222 }
 223
 224 bool write_packet(vpn_packet_t *packet) {
 225         long lenout;
 226         OVERLAPPED overlapped = {0};
 227
 228         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 229                            packet->len, device_info);
 230
 231         if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
 232                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 233                 return false;
 234         }
 235
 236         device_total_out += packet->len;
 237
 238         return true;
 239 }
 240
 241 void dump_device_stats(void) {
 242         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 243         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 244         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 245 }