git.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) {
  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         HANDLE thread;
  93
  94         get_config_string(lookup_config(config_tree, "Device"), &device);
  95         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  96
  97         /* Open registry and look for network adapters */
  98
  99         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
 100                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 101                 return false;
 102         }
 103
 104         for (i = 0; ; i++) {
 105                 len = sizeof adapterid;
 106                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
 107                         break;
 108
 109                 /* Find out more about this adapter */
 110
 111                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 112
 113                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
 114                         continue;
 115
 116                 len = sizeof adaptername;
 117                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 118
 119                 RegCloseKey(key2);
 120
 121                 if(err)
 122                         continue;
 123
 124                 if(device) {
 125                         if(!strcmp(device, adapterid)) {
 126                                 found = true;
 127                                 break;
 128                         } else
 129                                 continue;
 130                 }
 131
 132                 if(iface) {
 133                         if(!strcmp(iface, adaptername)) {
 134                                 found = true;
 135                                 break;
 136                         } else
 137                                 continue;
 138                 }
 139
 140                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 141                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 142                 if(device_handle != INVALID_HANDLE_VALUE) {
 143                         found = true;
 144                         break;
 145                 }
 146         }
 147
 148         RegCloseKey(key);
 149
 150         if(!found) {
 151                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 152                 return false;
 153         }
 154
 155         if(!device)
 156                 device = xstrdup(adapterid);
 157
 158         if(!iface)
 159                 iface = xstrdup(adaptername);
 160
 161         /* Try to open the corresponding tap device */
 162
 163         if(device_handle == INVALID_HANDLE_VALUE) {
 164                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 165                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 166         }
 167
 168         if(device_handle == INVALID_HANDLE_VALUE) {
 169                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 170                 return false;
 171         }
 172
 173         /* Get MAC address from tap device */
 174
 175         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
 176                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 177                 return false;
 178         }
 179
 180         if(routing_mode == RMODE_ROUTER) {
 181                 overwrite_mac = 1;
 182         }
 183
 184         /* Start the tap reader */
 185
 186         io_add_event(&device_read_io, device_handle_read, NULL, CreateEvent(NULL, TRUE, FALSE, NULL));
 187         device_read_overlapped.hEvent = device_read_io.event;
 188         device_issue_read();
 189
 190         device_info = "Windows tap device";
 191
 192         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 193
 194         return true;
 195 }
 196
 197 static void enable_device(void) {
 198         logger(DEBUG_ALWAYS, LOG_INFO, "Enabling %s", device_info);
 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
 204 static void disable_device(void) {
 205         logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
 206         ULONG status = 0;
 207         DWORD len;
 208         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
 209 }
 210
 211 static void close_device(void) {
 212         io_del(&device_read_io);
 213         CancelIo(device_handle);
 214         CloseHandle(device_read_overlapped.hEvent);
 215         CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
 216
 217         free(device); device = NULL;
 218         free(iface); iface = NULL;
 219         device_info = NULL;
 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 const devops_t os_devops = {
 244         .setup = setup_device,
 245         .close = close_device,
 246         .read = read_packet,
 247         .write = write_packet,
 248         .enable = enable_device,
 249         .disable = disable_device,
 250 };