www.tinc-vpn.org Git - tinc/blob - src/cygwin/device.c

   1 /*
   2     device.c -- Interaction with Windows tap driver in a Cygwin environment
   3     Copyright (C) 2002-2005 Ivo Timmermans,
   4                   2002-2009 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 <w32api/windows.h>
  24 #include <w32api/winioctl.h>
  25
  26 #include "conf.h"
  27 #include "logger.h"
  28 #include "net.h"
  29 #include "route.h"
  30 #include "utils.h"
  31 #include "xalloc.h"
  32
  33 #include "mingw/common.h"
  34
  35 int device_fd = -1;
  36 static HANDLE device_handle = INVALID_HANDLE_VALUE;
  37 char *device = NULL;
  38 char *iface = NULL;
  39 static char *device_info = NULL;
  40
  41 static int device_total_in = 0;
  42 static int device_total_out = 0;
  43
  44 static pid_t reader_pid;
  45 static int sp[2];
  46
  47 bool setup_device(void) {
  48         HKEY key, key2;
  49         int i, err;
  50
  51         char regpath[1024];
  52         char adapterid[1024];
  53         char adaptername[1024];
  54         char tapname[1024];
  55         char gelukt = 0;
  56         long len;
  57
  58         bool found = false;
  59
  60         get_config_string(lookup_config(config_tree, "Device"), &device);
  61         get_config_string(lookup_config(config_tree, "Interface"), &iface);
  62
  63         /* Open registry and look for network adapters */
  64
  65         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
  66                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
  67                 return false;
  68         }
  69
  70         for (i = 0; ; i++) {
  71                 len = sizeof(adapterid);
  72                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
  73                         break;
  74
  75                 /* Find out more about this adapter */
  76
  77                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
  78
  79                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
  80                         continue;
  81
  82                 len = sizeof(adaptername);
  83                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
  84
  85                 RegCloseKey(key2);
  86
  87                 if(err)
  88                         continue;
  89
  90                 if(device) {
  91                         if(!strcmp(device, adapterid)) {
  92                                 found = true;
  93                                 break;
  94                         } else
  95                                 continue;
  96                 }
  97
  98                 if(iface) {
  99                         if(!strcmp(iface, adaptername)) {
 100                                 found = true;
 101                                 break;
 102                         } else
 103                                 continue;
 104                 }
 105
 106                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 107                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
 108                 if(device_handle != INVALID_HANDLE_VALUE) {
 109                         CloseHandle(device_handle);
 110                         found = true;
 111                         break;
 112                 }
 113         }
 114
 115         RegCloseKey(key);
 116
 117         if(!found) {
 118                 logger(LOG_ERR, "No Windows tap device found!");
 119                 return false;
 120         }
 121
 122         if(!device)
 123                 device = xstrdup(adapterid);
 124
 125         if(!iface)
 126                 iface = xstrdup(adaptername);
 127
 128         snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 129
 130         /* Now we are going to open this device twice: once for reading and once for writing.
 131            We do this because apparently it isn't possible to check for activity in the select() loop.
 132            Furthermore I don't really know how to do it the "Windows" way. */
 133
 134         if(socketpair(AF_UNIX, SOCK_DGRAM, PF_UNIX, sp)) {
 135                 logger(LOG_DEBUG, "System call `%s' failed: %s", "socketpair", strerror(errno));
 136                 return false;
 137         }
 138
 139         /* The parent opens the tap device for writing. */
 140
 141         device_handle = CreateFile(tapname, GENERIC_WRITE,  FILE_SHARE_READ,  0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM , 0);
 142
 143         if(device_handle == INVALID_HANDLE_VALUE) {
 144                 logger(LOG_ERR, "Could not open Windows tap device %s (%s) for writing: %s", device, iface, winerror(GetLastError()));
 145                 return false;
 146         }
 147
 148         device_fd = sp[0];
 149
 150         /* Get MAC address from tap device */
 151
 152         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
 153                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 154                 return false;
 155         }
 156
 157         if(routing_mode == RMODE_ROUTER) {
 158                 overwrite_mac = 1;
 159         }
 160
 161         /* Now we start the child */
 162
 163         reader_pid = fork();
 164
 165         if(reader_pid == -1) {
 166                 logger(LOG_DEBUG, "System call `%s' failed: %s", "fork", strerror(errno));
 167                 return false;
 168         }
 169
 170         if(!reader_pid) {
 171                 /* The child opens the tap device for reading, blocking.
 172                    It passes everything it reads to the socket. */
 173
 174                 char buf[MTU];
 175                 long lenin;
 176
 177                 CloseHandle(device_handle);
 178
 179                 device_handle = CreateFile(tapname, GENERIC_READ, FILE_SHARE_WRITE, 0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
 180
 181                 if(device_handle == INVALID_HANDLE_VALUE) {
 182                         logger(LOG_ERR, "Could not open Windows tap device %s (%s) for reading: %s", device, iface, winerror(GetLastError()));
 183                         buf[0] = 0;
 184                         write(sp[1], buf, 1);
 185                         exit(1);
 186                 }
 187
 188                 logger(LOG_DEBUG, "Tap reader forked and running.");
 189
 190                 /* Notify success */
 191
 192                 buf[0] = 1;
 193                 write(sp[1], buf, 1);
 194
 195                 /* Pass packets */
 196
 197                 for(;;) {
 198                         ReadFile(device_handle, buf, MTU, &lenin, NULL);
 199                         write(sp[1], buf, lenin);
 200                 }
 201         }
 202
 203         read(device_fd, &gelukt, 1);
 204         if(gelukt != 1) {
 205                 logger(LOG_DEBUG, "Tap reader failed!");
 206                 return false;
 207         }
 208
 209         device_info = "Windows tap device";
 210
 211         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 212
 213         return true;
 214 }
 215
 216 void close_device(void) {
 217         close(sp[0]);
 218         close(sp[1]);
 219         CloseHandle(device_handle);
 220
 221         kill(reader_pid, SIGKILL);
 222
 223         free(device);
 224         free(iface);
 225 }
 226
 227 bool read_packet(vpn_packet_t *packet) {
 228         int lenin;
 229
 230         if((lenin = read(sp[0], packet->data, MTU)) <= 0) {
 231                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
 232                            device, strerror(errno));
 233                 return false;
 234         }
 235
 236         packet->len = lenin;
 237
 238         device_total_in += packet->len;
 239
 240         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
 241                            device_info);
 242
 243         return true;
 244 }
 245
 246 bool write_packet(vpn_packet_t *packet) {
 247         long lenout;
 248
 249         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
 250                            packet->len, device_info);
 251
 252         if(!WriteFile (device_handle, packet->data, packet->len, &lenout, NULL)) {
 253                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
 254                 return false;
 255         }
 256
 257         device_total_out += packet->len;
 258
 259         return true;
 260 }
 261
 262 void dump_device_stats(void) {
 263         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 264         logger(LOG_DEBUG, " total bytes in:  %10d", device_total_in);
 265         logger(LOG_DEBUG, " total bytes out: %10d", device_total_out);
 266 }