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 "../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 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                 event_flush_output();
  84                 LeaveCriticalSection(&mutex);
  85         }
  86 }
  87
  88 static bool setup_device(void) {
  89         HKEY key, key2;
  90         int i;
  91
  92         char regpath[1024];
  93         char adapterid[1024];
  94         char adaptername[1024];
  95         char tapname[1024];
  96         DWORD len;
  97         unsigned long status;
  98
  99         bool found = false;
 100
 101         int err;
 102         HANDLE thread;
 103
 104         get_config_string(lookup_config(config_tree, "Device"), &device);
 105         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 106
 107         /* Open registry and look for network adapters */
 108
 109         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 110                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 111                 return false;
 112         }
 113
 114         for (i = 0; ; i++) {
 115                 len = sizeof adapterid;
 116                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 117                         break;
 118
 119                 /* Find out more about this adapter */
 120
 121                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 122
 123                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 124                         continue;
 125
 126                 len = sizeof adaptername;
 127                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 128
 129                 RegCloseKey(key2);
 130
 131                 if(err)
 132                         continue;
 133
 134                 if(device) {
 135                         if(!strcmp(device, adapterid)) {
 136                                 found = true;
 137                                 break;
 138                         } else
 139                                 continue;
 140                 }
 141
 142                 if(iface) {
 143                         if(!strcmp(iface, adaptername)) {
 144                                 found = true;
 145                                 break;
 146                         } else
 147                                 continue;
 148                 }
 149
 150                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 151                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 152                 if(device_handle != INVALID_HANDLE_VALUE) {
 153                         found = true;
 154                         break;
 155                 }
 156         }
 157
 158         RegCloseKey(key);
 159
 160         if(!found) {
 161                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 162                 return false;
 163         }
 164
 165         if(!device)
 166                 device = xstrdup(adapterid);
 167
 168         if(!iface)
 169                 iface = xstrdup(adaptername);
 170
 171         /* Try to open the corresponding tap device */
 172
 173         if(device_handle == INVALID_HANDLE_VALUE) {
 174                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 175                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 176         }
 177
 178         if(device_handle == INVALID_HANDLE_VALUE) {
 179                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 180                 return false;
 181         }
 182
 183         /* Get MAC address from tap device */
 184
 185         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 186                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 187                 return false;
 188         }
 189
 190         if(routing_mode == RMODE_ROUTER) {
 191                 overwrite_mac = 1;
 192         }
 193
 194         /* Start the tap reader */
 195
 196         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
 197
 198         if(!thread) {
 199                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
 200                 return false;
 201         }
 202
 203         /* Set media status for newer TAP-Win32 devices */
 204
 205         status = true;
 206         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 207
 208         device_info = "Windows tap device";
 209
 210         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 211
 212         return true;
 213 }
 214
 215 static void close_device(void) {
 216         CloseHandle(device_handle);
 217
 218         free(device);
 219         free(iface);
 220 }
 221
 222 static bool read_packet(vpn_packet_t *packet) {
 223         return false;
 224 }
 225
 226 static bool write_packet(vpn_packet_t *packet) {
 227         DWORD outlen;
 228         OVERLAPPED overlapped = {0};
 229
 230         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 231                            packet->len, device_info);
 232
 233         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
 234                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 235                 return false;
 236         }
 237
 238         device_total_out += packet->len;
 239
 240         return true;
 241 }
 242
 243 static void dump_device_stats(void) {
 244         logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 245         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 246         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 247 }
 248
 249 const devops_t os_devops = {
 250         .setup = setup_device,
 251         .close = close_device,
 252         .read = read_packet,
 253         .write = write_packet,
 254         .dump_stats = dump_device_stats,
 255 };