/*
device.c -- Interaction with Windows tap driver in a MinGW environment
Copyright (C) 2002-2005 Ivo Timmermans,
- 2002-2011 Guus Sliepen <guus@tinc-vpn.org>
+ 2002-2014 Guus Sliepen <guus@tinc-vpn.org>
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
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#include "system.h"
+#include "../system.h"
#include <windows.h>
#include <winioctl.h>
-#include "conf.h"
-#include "device.h"
-#include "logger.h"
-#include "net.h"
-#include "route.h"
-#include "utils.h"
-#include "xalloc.h"
+#include "../conf.h"
+#include "../device.h"
+#include "../logger.h"
+#include "../names.h"
+#include "../net.h"
+#include "../route.h"
+#include "../utils.h"
+#include "../xalloc.h"
-#include "mingw/common.h"
+#include "common.h"
int device_fd = -1;
static HANDLE device_handle = INVALID_HANDLE_VALUE;
+static io_t device_read_io;
+static OVERLAPPED device_read_overlapped;
+static OVERLAPPED device_write_overlapped;
+static vpn_packet_t device_read_packet;
+static vpn_packet_t device_write_packet;
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;
-
extern char *myport;
-static DWORD WINAPI tapreader(void *bla) {
- int status;
- long len;
- OVERLAPPED overlapped;
- vpn_packet_t packet;
-
- logger(LOG_DEBUG, "Tap reader running");
-
- /* Read from tap device and send to parent */
-
- overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-
- for(;;) {
- overlapped.Offset = 0;
- overlapped.OffsetHigh = 0;
- ResetEvent(overlapped.hEvent);
+static void device_issue_read() {
+ device_read_overlapped.Offset = 0;
+ device_read_overlapped.OffsetHigh = 0;
- status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
-
- if(!status) {
- if(GetLastError() == ERROR_IO_PENDING) {
- WaitForSingleObject(overlapped.hEvent, INFINITE);
- if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
- continue;
- } else {
- logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
+ int status;
+ for (;;) {
+ DWORD len;
+ status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped);
+ if (!status) {
+ if (GetLastError() != ERROR_IO_PENDING)
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
device, strerror(errno));
- return -1;
- }
+ break;
}
- EnterCriticalSection(&mutex);
- packet.len = len;
- packet.priority = 0;
- route(myself, &packet);
- LeaveCriticalSection(&mutex);
+ device_read_packet.len = len;
+ device_read_packet.priority = 0;
+ route(myself, &device_read_packet);
+ }
+}
+
+static void device_handle_read(void *data, int flags) {
+ ResetEvent(device_read_overlapped.hEvent);
+
+ DWORD len;
+ if (!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info,
+ device, strerror(errno));
+ return;
}
+
+ device_read_packet.len = len;
+ device_read_packet.priority = 0;
+ route(myself, &device_read_packet);
+ device_issue_read();
}
static bool setup_device(void) {
char adapterid[1024];
char adaptername[1024];
char tapname[1024];
- long len;
- unsigned long status;
+ DWORD len;
bool found = false;
int err;
- HANDLE thread;
get_config_string(lookup_config(config_tree, "Device"), &device);
get_config_string(lookup_config(config_tree, "Interface"), &iface);
+ if(device && iface)
+ logger(DEBUG_ALWAYS, LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+
/* 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()));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
return false;
}
snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
- if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
+ if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
continue;
len = sizeof adaptername;
- err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
+ err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
RegCloseKey(key2);
RegCloseKey(key);
if(!found) {
- logger(LOG_ERR, "No Windows tap device found!");
+ logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
return false;
}
snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
}
-
+
if(device_handle == INVALID_HANDLE_VALUE) {
- logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
+ logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
return false;
}
+ /* Get version information from tap device */
+
+ {
+ ULONG info[3] = {0};
+ DWORD len;
+ if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof info, &info, sizeof info, &len, NULL))
+ logger(DEBUG_ALWAYS, LOG_WARNING, "Could not get version information from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
+ else {
+ logger(DEBUG_ALWAYS, LOG_INFO, "TAP-Windows driver version: %lu.%lu%s", info[0], info[1], info[2] ? " (DEBUG)" : "");
+
+ /* Warn if using >=9.21. This is because starting from 9.21, TAP-Win32 seems to use a different, less efficient write path. */
+ if(info[0] == 9 && info[1] >= 21)
+ logger(DEBUG_ALWAYS, LOG_WARNING,
+ "You are using the newer (>= 9.0.0.21, NDIS6) series of TAP-Win32 drivers. "
+ "Using these drivers with tinc is not recommanded as it can result in poor performance. "
+ "You might want to revert back to 9.0.0.9 instead.");
+ }
+ }
+
/* 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()));
+ logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
return false;
}
overwrite_mac = 1;
}
- /* Start the tap reader */
+ device_info = "Windows tap device";
- thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
+ logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
- if(!thread) {
- logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
- return false;
- }
+ return true;
+}
- /* Set media status for newer TAP-Win32 devices */
+static void enable_device(void) {
+ logger(DEBUG_ALWAYS, LOG_INFO, "Enabling %s", device_info);
- status = true;
+ ULONG status = 1;
+ DWORD len;
DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
- device_info = "Windows tap device";
+ /* We don't use the write event directly, but GetOverlappedResult() does, internally. */
- logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
+ device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+ device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
- return true;
+ io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent);
+ device_issue_read();
+}
+
+static void disable_device(void) {
+ logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
+
+ io_del(&device_read_io);
+ CancelIo(device_handle);
+
+ /* According to MSDN, CancelIo() does not necessarily wait for the operation to complete.
+ To prevent race conditions, make sure the operation is complete
+ before we close the event it's referencing. */
+
+ DWORD len;
+ if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED)
+ logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s read to cancel: %s", device_info, device, winerror(GetLastError()));
+ if(device_write_packet.len > 0 && !GetOverlappedResult(device_handle, &device_write_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED)
+ logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s write to cancel: %s", device_info, device, winerror(GetLastError()));
+ device_write_packet.len = 0;
+
+ CloseHandle(device_read_overlapped.hEvent);
+ CloseHandle(device_write_overlapped.hEvent);
+
+ ULONG status = 0;
+ DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
}
static void close_device(void) {
- CloseHandle(device_handle);
+ CloseHandle(device_handle); device_handle = INVALID_HANDLE_VALUE;
- free(device);
- free(iface);
+ free(device); device = NULL;
+ free(iface); iface = NULL;
+ device_info = NULL;
}
static bool read_packet(vpn_packet_t *packet) {
}
static bool write_packet(vpn_packet_t *packet) {
- long outlen;
- OVERLAPPED overlapped = {0};
+ DWORD outlen;
- ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
+ logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
packet->len, device_info);
- if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
- logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
- return false;
+ if(device_write_packet.len > 0) {
+ /* Make sure the previous write operation is finished before we start the next one;
+ otherwise we end up with multiple write ops referencing the same OVERLAPPED structure,
+ which according to MSDN is a no-no. */
+
+ if(!GetOverlappedResult(device_handle, &device_write_overlapped, &outlen, FALSE)) {
+ int log_level = (GetLastError() == ERROR_IO_INCOMPLETE) ? DEBUG_TRAFFIC : DEBUG_ALWAYS;
+ logger(log_level, LOG_ERR, "Error while checking previous write to %s %s: %s", device_info, device, winerror(GetLastError()));
+ return false;
+ }
}
- device_total_out += packet->len;
+ /* Copy the packet, since the write operation might still be ongoing after we return. */
- return true;
-}
+ memcpy(&device_write_packet, packet, sizeof *packet);
-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);
+ if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped))
+ device_write_packet.len = 0;
+ else if (GetLastError() != ERROR_IO_PENDING) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
+ return false;
+ }
+
+ return true;
}
const devops_t os_devops = {
.close = close_device,
.read = read_packet,
.write = write_packet,
- .dump_stats = dump_device_stats,
+ .enable = enable_device,
+ .disable = disable_device,
};
projects / tinc / blobdiff