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