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 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 static uint64_t device_total_in = 0;
  47 static uint64_t device_total_out = 0;
  48
  49 extern char *myport;
  50
  51 static void device_issue_read() {
  52         device_read_overlapped.Offset = 0;
  53         device_read_overlapped.OffsetHigh = 0;
  54
  55         int status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, NULL, &device_read_overlapped);
  56
  57         if(!status && GetLastError() != ERROR_IO_PENDING) {
  58                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
  59                            device, strerror(errno));
  60         }
  61 }
  62
  63 static void device_handle_read(void *data, int flags) {
  64         ResetEvent(device_read_overlapped.hEvent);
  65
  66         DWORD len;
  67         if (!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) {
  68                 logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info,
  69                            device, strerror(errno));
  70                 return;
  71         }
  72
  73         device_read_packet.len = len;
  74         device_read_packet.priority = 0;
  75         route(myself, &device_read_packet);
  76         device_issue_read();
  77 }
  78
  79 static bool setup_device(void) {
  80         HKEY key, key2;
  81         int i;
  82
  83         char regpath[1024];
  84         char adapterid[1024];
  85         char adaptername[1024];
  86         char tapname[1024];
  87         DWORD len;
  88
  89         bool found = false;
  90
  91         int err;
  92
  93         get_config_string(lookup_config(config_tree, "Device"), &device);
  94         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  95
  96         /* Open registry and look for network adapters */
  97
  98         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
  99                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 100                 return false;
 101         }
 102
 103         for (i = 0; ; i++) {
 104                 len = sizeof adapterid;
 105                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 106                         break;
 107
 108                 /* Find out more about this adapter */
 109
 110                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 111
 112                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 113                         continue;
 114
 115                 len = sizeof adaptername;
 116                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 117
 118                 RegCloseKey(key2);
 119
 120                 if(err)
 121                         continue;
 122
 123                 if(device) {
 124                         if(!strcmp(device, adapterid)) {
 125                                 found = true;
 126                                 break;
 127                         } else
 128                                 continue;
 129                 }
 130
 131                 if(iface) {
 132                         if(!strcmp(iface, adaptername)) {
 133                                 found = true;
 134                                 break;
 135                         } else
 136                                 continue;
 137                 }
 138
 139                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 140                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 141                 if(device_handle != INVALID_HANDLE_VALUE) {
 142                         found = true;
 143                         break;
 144                 }
 145         }
 146
 147         RegCloseKey(key);
 148
 149         if(!found) {
 150                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 151                 return false;
 152         }
 153
 154         if(!device)
 155                 device = xstrdup(adapterid);
 156
 157         if(!iface)
 158                 iface = xstrdup(adaptername);
 159
 160         /* Try to open the corresponding tap device */
 161
 162         if(device_handle == INVALID_HANDLE_VALUE) {
 163                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 164                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 165         }
 166
 167         if(device_handle == INVALID_HANDLE_VALUE) {
 168                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 169                 return false;
 170         }
 171
 172         /* Get MAC address from tap device */
 173
 174         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 175                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 176                 return false;
 177         }
 178
 179         if(routing_mode == RMODE_ROUTER) {
 180                 overwrite_mac = 1;
 181         }
 182
 183         /* Start the tap reader */
 184
 185         io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL));
 186         device_read_overlapped.hEvent = device_read_io.event;
 187         device_issue_read();
 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         ULONG status = 1;
 199         DWORD len;
 200         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 201 }
 202
 203 static void disable_device(void) {
 204         logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
 205         ULONG status = 0;
 206         DWORD len;
 207         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 208 }
 209
 210 static void close_device(void) {
 211         io_del(&device_read_io);
 212         CancelIo(device_handle);
 213         CloseHandle(device_read_overlapped.hEvent);
 214         CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 215
 216         free(device); device = NULL;
 217         free(iface); iface = NULL;
 218         device_info = NULL;
 219 }
 220
 221 static bool read_packet(vpn_packet_t *packet) {
 222         return false;
 223 }
 224
 225 static bool write_packet(vpn_packet_t *packet) {
 226         DWORD outlen;
 227         OVERLAPPED overlapped = {0};
 228
 229         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 230                            packet->len, device_info);
 231
 232         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
 233                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 234                 return false;
 235         }
 236
 237         device_total_out += packet->len;
 238
 239         return true;
 240 }
 241
 242 const devops_t os_devops = {
 243         .setup = setup_device,
 244         .close = close_device,
 245         .read = read_packet,
 246         .write = write_packet,
 247         .enable = enable_device,
 248         .disable = disable_device,
 249 };