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 static io_t device_read_io;
  40 static OVERLAPPED device_read_overlapped;
  41 static vpn_packet_t device_read_packet;
  42 char *device = NULL;
  43 char *iface = NULL;
  44 static char *device_info = NULL;
  45
  46 extern char *myport;
  47
  48 static void device_issue_read() {
  49         device_read_overlapped.Offset = 0;
  50         device_read_overlapped.OffsetHigh = 0;
  51
  52         int status;
  53         for (;;) {
  54                 DWORD len;
  55                 status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped);
  56                 if (!status) {
  57                         if (GetLastError() != ERROR_IO_PENDING)
  58                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
  59                                            device, strerror(errno));
  60                         break;
  61                 }
  62
  63                 device_read_packet.len = len;
  64                 device_read_packet.priority = 0;
  65                 route(myself, &device_read_packet);
  66         }
  67 }
  68
  69 static void device_handle_read(void *data, int flags) {
  70         ResetEvent(device_read_overlapped.hEvent);
  71
  72         DWORD len;
  73         if (!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) {
  74                 logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info,
  75                            device, strerror(errno));
  76                 return;
  77         }
  78
  79         device_read_packet.len = len;
  80         device_read_packet.priority = 0;
  81         route(myself, &device_read_packet);
  82         device_issue_read();
  83 }
  84
  85 static bool setup_device(void) {
  86         HKEY key, key2;
  87         int i;
  88
  89         char regpath[1024];
  90         char adapterid[1024];
  91         char adaptername[1024];
  92         char tapname[1024];
  93         DWORD len;
  94
  95         bool found = false;
  96
  97         int err;
  98
  99         get_config_string(lookup_config(config_tree, "Device"), &device);
 100         get_config_string(lookup_config(config_tree, "Interface"), &iface);
 101
 102         /* Open registry and look for network adapters */
 103
 104         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 105                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 106                 return false;
 107         }
 108
 109         for (i = 0; ; i++) {
 110                 len = sizeof adapterid;
 111                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 112                         break;
 113
 114                 /* Find out more about this adapter */
 115
 116                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 117
 118                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 119                         continue;
 120
 121                 len = sizeof adaptername;
 122                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 123
 124                 RegCloseKey(key2);
 125
 126                 if(err)
 127                         continue;
 128
 129                 if(device) {
 130                         if(!strcmp(device, adapterid)) {
 131                                 found = true;
 132                                 break;
 133                         } else
 134                                 continue;
 135                 }
 136
 137                 if(iface) {
 138                         if(!strcmp(iface, adaptername)) {
 139                                 found = true;
 140                                 break;
 141                         } else
 142                                 continue;
 143                 }
 144
 145                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 146                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 147                 if(device_handle != INVALID_HANDLE_VALUE) {
 148                         found = true;
 149                         break;
 150                 }
 151         }
 152
 153         RegCloseKey(key);
 154
 155         if(!found) {
 156                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 157                 return false;
 158         }
 159
 160         if(!device)
 161                 device = xstrdup(adapterid);
 162
 163         if(!iface)
 164                 iface = xstrdup(adaptername);
 165
 166         /* Try to open the corresponding tap device */
 167
 168         if(device_handle == INVALID_HANDLE_VALUE) {
 169                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 170                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 171         }
 172
 173         if(device_handle == INVALID_HANDLE_VALUE) {
 174                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 175                 return false;
 176         }
 177
 178         /* Get MAC address from tap device */
 179
 180         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 181                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 182                 return false;
 183         }
 184
 185         if(routing_mode == RMODE_ROUTER) {
 186                 overwrite_mac = 1;
 187         }
 188
 189         device_info = "Windows tap device";
 190
 191         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 192
 193         return true;
 194 }
 195
 196 static void enable_device(void) {
 197         logger(DEBUG_ALWAYS, LOG_INFO, "Enabling %s", device_info);
 198
 199         ULONG status = 1;
 200         DWORD len;
 201         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 202
 203         io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL));
 204         device_read_overlapped.hEvent = device_read_io.event;
 205         device_issue_read();
 206 }
 207
 208 static void disable_device(void) {
 209         logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
 210
 211         io_del(&device_read_io);
 212         CancelIo(device_handle);
 213         CloseHandle(device_read_overlapped.hEvent);
 214
 215         ULONG status = 0;
 216         DWORD len;
 217         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 218 }
 219
 220 static void close_device(void) {
 221         CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 222
 223         free(device); device = NULL;
 224         free(iface); iface = NULL;
 225         device_info = NULL;
 226 }
 227
 228 static bool read_packet(vpn_packet_t *packet) {
 229         return false;
 230 }
 231
 232 static bool write_packet(vpn_packet_t *packet) {
 233         DWORD outlen;
 234         OVERLAPPED overlapped = {0};
 235
 236         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 237                            packet->len, device_info);
 238
 239         if(!WriteFile(device_handle, DATA(packet), packet->len, &outlen, &overlapped)) {
 240                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 241                 return false;
 242         }
 243
 244         return true;
 245 }
 246
 247 const devops_t os_devops = {
 248         .setup = setup_device,
 249         .close = close_device,
 250         .read = read_packet,
 251         .write = write_packet,
 252         .enable = enable_device,
 253         .disable = disable_device,
 254 };