/* device.c -- Interaction with Windows tap driver in a Cygwin environment Copyright (C) 2002-2005 Ivo Timmermans, 2002-2011 Guus Sliepen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" #include #include #include "conf.h" #include "device.h" #include "logger.h" #include "net.h" #include "route.h" #include "utils.h" #include "xalloc.h" #include "mingw/common.h" int device_fd = -1; static HANDLE device_handle = INVALID_HANDLE_VALUE; char *device = NULL; char *iface = NULL; static char *device_info = NULL; static uint64_t device_total_in = 0; static uint64_t device_total_out = 0; static pid_t reader_pid; static int sp[2]; static bool setup_device(void) { HKEY key, key2; int i, err; char regpath[1024]; char adapterid[1024]; char adaptername[1024]; char tapname[1024]; char gelukt = 0; long len; bool found = false; get_config_string(lookup_config(config_tree, "Device"), &device); get_config_string(lookup_config(config_tree, "Interface"), &iface); /* Open registry and look for network adapters */ if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) { logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError())); return false; } for (i = 0; ; i++) { len = sizeof(adapterid); if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL)) break; /* Find out more about this adapter */ snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid); if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2)) continue; len = sizeof(adaptername); err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len); RegCloseKey(key2); if(err) continue; if(device) { if(!strcmp(device, adapterid)) { found = true; break; } else continue; } if(iface) { if(!strcmp(iface, adaptername)) { found = true; break; } else continue; } snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid); device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0); if(device_handle != INVALID_HANDLE_VALUE) { CloseHandle(device_handle); found = true; break; } } RegCloseKey(key); if(!found) { logger(LOG_ERR, "No Windows tap device found!"); return false; } if(!device) device = xstrdup(adapterid); if(!iface) iface = xstrdup(adaptername); snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device); /* Now we are going to open this device twice: once for reading and once for writing. We do this because apparently it isn't possible to check for activity in the select() loop. Furthermore I don't really know how to do it the "Windows" way. */ if(socketpair(AF_UNIX, SOCK_DGRAM, PF_UNIX, sp)) { logger(LOG_DEBUG, "System call `%s' failed: %s", "socketpair", strerror(errno)); return false; } /* The parent opens the tap device for writing. */ device_handle = CreateFile(tapname, GENERIC_WRITE, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM , 0); if(device_handle == INVALID_HANDLE_VALUE) { logger(LOG_ERR, "Could not open Windows tap device %s (%s) for writing: %s", device, iface, winerror(GetLastError())); return false; } device_fd = sp[0]; /* Get MAC address from tap device */ if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) { logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError())); return false; } if(routing_mode == RMODE_ROUTER) { overwrite_mac = 1; } /* Now we start the child */ reader_pid = fork(); if(reader_pid == -1) { logger(LOG_DEBUG, "System call `%s' failed: %s", "fork", strerror(errno)); return false; } if(!reader_pid) { /* The child opens the tap device for reading, blocking. It passes everything it reads to the socket. */ char buf[MTU]; long lenin; CloseHandle(device_handle); device_handle = CreateFile(tapname, GENERIC_READ, FILE_SHARE_WRITE, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0); if(device_handle == INVALID_HANDLE_VALUE) { logger(LOG_ERR, "Could not open Windows tap device %s (%s) for reading: %s", device, iface, winerror(GetLastError())); buf[0] = 0; write(sp[1], buf, 1); exit(1); } logger(LOG_DEBUG, "Tap reader forked and running."); /* Notify success */ buf[0] = 1; write(sp[1], buf, 1); /* Pass packets */ for(;;) { ReadFile(device_handle, buf, MTU, &lenin, NULL); write(sp[1], buf, lenin); } } read(device_fd, &gelukt, 1); if(gelukt != 1) { logger(LOG_DEBUG, "Tap reader failed!"); return false; } device_info = "Windows tap device"; logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info); return true; } static void close_device(void) { close(sp[0]); close(sp[1]); CloseHandle(device_handle); kill(reader_pid, SIGKILL); free(device); free(iface); } static bool read_packet(vpn_packet_t *packet) { int lenin; if((lenin = read(sp[0], packet->data, MTU)) <= 0) { logger(LOG_ERR, "Error while reading from %s %s: %s", device_info, device, strerror(errno)); return false; } packet->len = lenin; device_total_in += packet->len; ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len, device_info); return true; } static bool write_packet(vpn_packet_t *packet) { long lenout; ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s", packet->len, device_info); if(!WriteFile (device_handle, packet->data, packet->len, &lenout, NULL)) { logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError())); return false; } device_total_out += packet->len; return true; } static void dump_device_stats(void) { logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device); logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in); logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out); } const devops_t os_devops = { .setup = setup_device, .close = close_device, .read = read_packet, .write = write_packet, .dump_stats = dump_device_stats, };