Merge branch 'debian/experimental-2.5'

1 files changed, 1441 insertions, 0 deletions

diff --git a/src/tapctl/tap.c b/src/tapctl/tap.c
new file mode 100644
index 0000000..7cb3ded
--- /dev/null
+++ b/src/tapctl/tap.c
@@ -0,0 +1,1441 @@
+/*
+ *  tapctl -- Utility to manipulate TUN/TAP adapters on Windows
+ *            https://community.openvpn.net/openvpn/wiki/Tapctl
+ *
+ *  Copyright (C) 2018-2020 Simon Rozman <simon@rozman.si>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#elif defined(_MSC_VER)
+#include <config-msvc.h>
+#endif
+
+#include "tap.h"
+#include "error.h"
+
+#include <windows.h>
+#include <cfgmgr32.h>
+#include <objbase.h>
+#include <setupapi.h>
+#include <stdio.h>
+#include <tchar.h>
+
+#ifdef _MSC_VER
+#pragma comment(lib, "advapi32.lib")
+#pragma comment(lib, "ole32.lib")
+#pragma comment(lib, "setupapi.lib")
+#endif
+
+const static GUID GUID_DEVCLASS_NET = { 0x4d36e972L, 0xe325, 0x11ce, { 0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18 } };
+
+const static TCHAR szAdapterRegKeyPathTemplate[] = TEXT("SYSTEM\\CurrentControlSet\\Control\\Network\\%") TEXT(PRIsLPOLESTR) TEXT("\\%") TEXT(PRIsLPOLESTR) TEXT("\\Connection");
+#define ADAPTER_REGKEY_PATH_MAX (_countof(TEXT("SYSTEM\\CurrentControlSet\\Control\\Network\\")) - 1 + 38 + _countof(TEXT("\\")) - 1 + 38 + _countof(TEXT("\\Connection")))
+
+
+/**
+ * Returns length of string of strings
+ *
+ * @param szz           Pointer to a string of strings (terminated by an empty string)
+ *
+ * @return Number of characters not counting the final zero terminator
+ **/
+static inline size_t
+_tcszlen(_In_z_ LPCTSTR szz)
+{
+    LPCTSTR s;
+    for (s = szz; s[0]; s += _tcslen(s) + 1)
+    {
+    }
+    return s - szz;
+}
+
+
+/**
+ * Checks if string is contained in the string of strings. Comparison is made case-insensitive.
+ *
+ * @param szzHay        Pointer to a string of strings (terminated by an empty string) we are
+ *                      looking in
+ *
+ * @param szNeedle      The string we are searching for
+ *
+ * @return Pointer to the string in szzHay that matches szNeedle is found; NULL otherwise
+ */
+static LPCTSTR
+_tcszistr(_In_z_ LPCTSTR szzHay, _In_z_ LPCTSTR szNeedle)
+{
+    for (LPCTSTR s = szzHay; s[0]; s += _tcslen(s) + 1)
+    {
+        if (_tcsicmp(s, szNeedle) == 0)
+        {
+            return s;
+        }
+    }
+
+    return NULL;
+}
+
+
+/**
+ * Function that performs a specific task on a device
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+typedef DWORD (*devop_func_t)(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _Inout_ LPBOOL pbRebootRequired);
+
+
+/**
+ * Checks device install parameters if a system reboot is required.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+check_reboot(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    if (pbRebootRequired == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    SP_DEVINSTALL_PARAMS devinstall_params = { .cbSize = sizeof(SP_DEVINSTALL_PARAMS) };
+    if (!SetupDiGetDeviceInstallParams(
+            hDeviceInfoSet,
+            pDeviceInfoData,
+            &devinstall_params))
+    {
+        DWORD dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiGetDeviceInstallParams failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    if ((devinstall_params.Flags & (DI_NEEDREBOOT | DI_NEEDRESTART)) != 0)
+    {
+        *pbRebootRequired = TRUE;
+    }
+
+    return ERROR_SUCCESS;
+}
+
+
+/**
+ * Deletes the device.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+delete_device(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    SP_REMOVEDEVICE_PARAMS params =
+    {
+        .ClassInstallHeader =
+        {
+            .cbSize = sizeof(SP_CLASSINSTALL_HEADER),
+            .InstallFunction = DIF_REMOVE,
+        },
+        .Scope = DI_REMOVEDEVICE_GLOBAL,
+        .HwProfile = 0,
+    };
+
+    /* Set class installer parameters for DIF_REMOVE. */
+    if (!SetupDiSetClassInstallParams(
+            hDeviceInfoSet,
+            pDeviceInfoData,
+            &params.ClassInstallHeader,
+            sizeof(SP_REMOVEDEVICE_PARAMS)))
+    {
+        DWORD dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiSetClassInstallParams failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Call appropriate class installer. */
+    if (!SetupDiCallClassInstaller(
+            DIF_REMOVE,
+            hDeviceInfoSet,
+            pDeviceInfoData))
+    {
+        DWORD dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_REMOVE) failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Check if a system reboot is required. */
+    check_reboot(hDeviceInfoSet, pDeviceInfoData, pbRebootRequired);
+    return ERROR_SUCCESS;
+}
+
+
+/**
+ * Changes the device state.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param bEnable       TRUE to enable the device; FALSE to disable.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+change_device_state(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _In_ BOOL bEnable,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    SP_PROPCHANGE_PARAMS params =
+    {
+        .ClassInstallHeader =
+        {
+            .cbSize = sizeof(SP_CLASSINSTALL_HEADER),
+            .InstallFunction = DIF_PROPERTYCHANGE,
+        },
+        .StateChange = bEnable ? DICS_ENABLE : DICS_DISABLE,
+        .Scope = DICS_FLAG_GLOBAL,
+        .HwProfile = 0,
+    };
+
+    /* Set class installer parameters for DIF_PROPERTYCHANGE. */
+    if (!SetupDiSetClassInstallParams(
+            hDeviceInfoSet,
+            pDeviceInfoData,
+            &params.ClassInstallHeader,
+            sizeof(SP_PROPCHANGE_PARAMS)))
+    {
+        DWORD dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiSetClassInstallParams failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Call appropriate class installer. */
+    if (!SetupDiCallClassInstaller(
+            DIF_PROPERTYCHANGE,
+            hDeviceInfoSet,
+            pDeviceInfoData))
+    {
+        DWORD dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_PROPERTYCHANGE) failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Check if a system reboot is required. */
+    check_reboot(hDeviceInfoSet, pDeviceInfoData, pbRebootRequired);
+    return ERROR_SUCCESS;
+}
+
+
+/**
+ * Enables the device.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+enable_device(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    return change_device_state(hDeviceInfoSet, pDeviceInfoData, TRUE, pbRebootRequired);
+}
+
+
+/**
+ * Disables the device.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+disable_device(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    return change_device_state(hDeviceInfoSet, pDeviceInfoData, FALSE, pbRebootRequired);
+}
+
+
+/**
+ * Reads string value from registry key.
+ *
+ * @param hKey          Handle of the registry key to read from. Must be opened with read
+ *                      access.
+ *
+ * @param szName        Name of the value to read.
+ *
+ * @param pszValue      Pointer to string to retrieve registry value. If the value type is
+ *                      REG_EXPAND_SZ the value is expanded using ExpandEnvironmentStrings().
+ *                      The string must be released with free() after use.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ */
+static DWORD
+get_reg_string(
+    _In_ HKEY hKey,
+    _In_ LPCTSTR szName,
+    _Out_ LPTSTR *pszValue)
+{
+    if (pszValue == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    DWORD dwValueType = REG_NONE, dwSize = 0;
+    DWORD dwResult = RegQueryValueEx(
+        hKey,
+        szName,
+        NULL,
+        &dwValueType,
+        NULL,
+        &dwSize);
+    if (dwResult != ERROR_SUCCESS)
+    {
+        SetLastError(dwResult); /* MSDN does not mention RegQueryValueEx() to set GetLastError(). But we do have an error code. Set last error manually. */
+        msg(M_NONFATAL | M_ERRNO, "%s: enumerating \"%" PRIsLPTSTR "\" registry value failed", __FUNCTION__, szName);
+        return dwResult;
+    }
+
+    switch (dwValueType)
+    {
+        case REG_SZ:
+        case REG_EXPAND_SZ:
+        {
+            /* Read value. */
+            LPTSTR szValue = (LPTSTR)malloc(dwSize);
+            if (szValue == NULL)
+            {
+                msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, dwSize);
+                return ERROR_OUTOFMEMORY;
+            }
+
+            dwResult = RegQueryValueEx(
+                hKey,
+                szName,
+                NULL,
+                NULL,
+                (LPBYTE)szValue,
+                &dwSize);
+            if (dwResult != ERROR_SUCCESS)
+            {
+                SetLastError(dwResult); /* MSDN does not mention RegQueryValueEx() to set GetLastError(). But we do have an error code. Set last error manually. */
+                msg(M_NONFATAL | M_ERRNO, "%s: reading \"%" PRIsLPTSTR "\" registry value failed", __FUNCTION__, szName);
+                free(szValue);
+                return dwResult;
+            }
+
+            if (dwValueType == REG_EXPAND_SZ)
+            {
+                /* Expand the environment strings. */
+                DWORD
+                    dwSizeExp = dwSize * 2,
+                    dwCountExp =
+#ifdef UNICODE
+                    dwSizeExp / sizeof(TCHAR);
+#else
+                    dwSizeExp / sizeof(TCHAR) - 1;     /* Note: ANSI version requires one extra char. */
+#endif
+                LPTSTR szValueExp = (LPTSTR)malloc(dwSizeExp);
+                if (szValueExp == NULL)
+                {
+                    free(szValue);
+                    msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, dwSizeExp);
+                    return ERROR_OUTOFMEMORY;
+                }
+
+                DWORD dwCountExpResult = ExpandEnvironmentStrings(
+                    szValue,
+                    szValueExp, dwCountExp
+                    );
+                if (dwCountExpResult == 0)
+                {
+                    msg(M_NONFATAL | M_ERRNO, "%s: expanding \"%" PRIsLPTSTR "\" registry value failed", __FUNCTION__, szName);
+                    free(szValueExp);
+                    free(szValue);
+                    return dwResult;
+                }
+                else if (dwCountExpResult <= dwCountExp)
+                {
+                    /* The buffer was big enough. */
+                    free(szValue);
+                    *pszValue = szValueExp;
+                    return ERROR_SUCCESS;
+                }
+                else
+                {
+                    /* Retry with a bigger buffer. */
+                    free(szValueExp);
+#ifdef UNICODE
+                    dwSizeExp = dwCountExpResult * sizeof(TCHAR);
+#else
+                    /* Note: ANSI version requires one extra char. */
+                    dwSizeExp = (dwCountExpResult + 1) * sizeof(TCHAR);
+#endif
+                    dwCountExp = dwCountExpResult;
+                    szValueExp = (LPTSTR)malloc(dwSizeExp);
+                    if (szValueExp == NULL)
+                    {
+                        free(szValue);
+                        msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, dwSizeExp);
+                        return ERROR_OUTOFMEMORY;
+                    }
+
+                    dwCountExpResult = ExpandEnvironmentStrings(
+                        szValue,
+                        szValueExp, dwCountExp);
+                    free(szValue);
+                    *pszValue = szValueExp;
+                    return ERROR_SUCCESS;
+                }
+            }
+            else
+            {
+                *pszValue = szValue;
+                return ERROR_SUCCESS;
+            }
+        }
+
+        default:
+            msg(M_NONFATAL, "%s: \"%" PRIsLPTSTR "\" registry value is not string (type %u)", __FUNCTION__, dwValueType);
+            return ERROR_UNSUPPORTED_TYPE;
+    }
+}
+
+
+/**
+ * Returns network adapter ID.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param iNumAttempts  After the device is created, it might take some time before the
+ *                      registry key is populated. This parameter specifies the number of
+ *                      attempts to read NetCfgInstanceId value from registry. A 1sec sleep
+ *                      is inserted between retry attempts.
+ *
+ * @param pguidAdapter  A pointer to GUID that receives network adapter ID.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+get_net_adapter_guid(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _In_ int iNumAttempts,
+    _Out_ LPGUID pguidAdapter)
+{
+    DWORD dwResult = ERROR_BAD_ARGUMENTS;
+
+    if (pguidAdapter == NULL || iNumAttempts < 1)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Open HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\<class>\<id> registry key. */
+    HKEY hKey = SetupDiOpenDevRegKey(
+        hDeviceInfoSet,
+        pDeviceInfoData,
+        DICS_FLAG_GLOBAL,
+        0,
+        DIREG_DRV,
+        KEY_READ);
+    if (hKey == INVALID_HANDLE_VALUE)
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiOpenDevRegKey failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    while (iNumAttempts > 0)
+    {
+        /* Query the NetCfgInstanceId value. Using get_reg_string() right on might clutter the output with error messages while the registry is still being populated. */
+        LPTSTR szCfgGuidString = NULL;
+        dwResult = RegQueryValueEx(hKey, TEXT("NetCfgInstanceId"), NULL, NULL, NULL, NULL);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            if (dwResult == ERROR_FILE_NOT_FOUND && --iNumAttempts > 0)
+            {
+                /* Wait and retry. */
+                Sleep(1000);
+                continue;
+            }
+
+            SetLastError(dwResult); /* MSDN does not mention RegQueryValueEx() to set GetLastError(). But we do have an error code. Set last error manually. */
+            msg(M_NONFATAL | M_ERRNO, "%s: querying \"NetCfgInstanceId\" registry value failed", __FUNCTION__);
+            break;
+        }
+
+        /* Read the NetCfgInstanceId value now. */
+        dwResult = get_reg_string(
+            hKey,
+            TEXT("NetCfgInstanceId"),
+            &szCfgGuidString);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            break;
+        }
+
+        dwResult = SUCCEEDED(CLSIDFromString(szCfgGuidString, (LPCLSID)pguidAdapter)) ? ERROR_SUCCESS : ERROR_INVALID_DATA;
+        free(szCfgGuidString);
+        break;
+    }
+
+    RegCloseKey(hKey);
+    return dwResult;
+}
+
+
+/**
+ * Returns a specified Plug and Play device property.
+ *
+ * @param hDeviceInfoSet  A handle to a device information set that contains a device
+ *                      information element that represents the device.
+ *
+ * @param pDeviceInfoData  A pointer to an SP_DEVINFO_DATA structure that specifies the
+ *                      device information element in hDeviceInfoSet.
+ *
+ * @param dwProperty     Specifies the property to be retrieved. See
+ *                       https://msdn.microsoft.com/en-us/library/windows/hardware/ff551967.aspx
+ *
+ * @pdwPropertyRegDataType  A pointer to a variable that receives the data type of the
+ *                       property that is being retrieved. This is one of the standard
+ *                       registry data types. This parameter is optional and can be NULL.
+ *
+ * @param ppData         A pointer to pointer to data that receives the device property. The
+ *                       data must be released with free() after use.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+get_device_reg_property(
+    _In_ HDEVINFO hDeviceInfoSet,
+    _In_ PSP_DEVINFO_DATA pDeviceInfoData,
+    _In_ DWORD dwProperty,
+    _Out_opt_ LPDWORD pdwPropertyRegDataType,
+    _Out_ LPVOID *ppData)
+{
+    DWORD dwResult = ERROR_BAD_ARGUMENTS;
+
+    if (ppData == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Try with stack buffer first. */
+    BYTE bBufStack[128];
+    DWORD dwRequiredSize = 0;
+    if (SetupDiGetDeviceRegistryProperty(
+            hDeviceInfoSet,
+            pDeviceInfoData,
+            dwProperty,
+            pdwPropertyRegDataType,
+            bBufStack,
+            sizeof(bBufStack),
+            &dwRequiredSize))
+    {
+        /* Copy from stack. */
+        *ppData = malloc(dwRequiredSize);
+        if (*ppData == NULL)
+        {
+            msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, dwRequiredSize);
+            return ERROR_OUTOFMEMORY;
+        }
+
+        memcpy(*ppData, bBufStack, dwRequiredSize);
+        return ERROR_SUCCESS;
+    }
+    else
+    {
+        dwResult = GetLastError();
+        if (dwResult == ERROR_INSUFFICIENT_BUFFER)
+        {
+            /* Allocate on heap and retry. */
+            *ppData = malloc(dwRequiredSize);
+            if (*ppData == NULL)
+            {
+                msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, dwRequiredSize);
+                return ERROR_OUTOFMEMORY;
+            }
+
+            if (SetupDiGetDeviceRegistryProperty(
+                    hDeviceInfoSet,
+                    pDeviceInfoData,
+                    dwProperty,
+                    pdwPropertyRegDataType,
+                    *ppData,
+                    dwRequiredSize,
+                    &dwRequiredSize))
+            {
+                return ERROR_SUCCESS;
+            }
+            else
+            {
+                dwResult = GetLastError();
+                msg(M_NONFATAL | M_ERRNO, "%s: SetupDiGetDeviceRegistryProperty(%u) failed", __FUNCTION__, dwProperty);
+                return dwResult;
+            }
+        }
+        else
+        {
+            msg(M_NONFATAL | M_ERRNO, "%s: SetupDiGetDeviceRegistryProperty(%u) failed", __FUNCTION__, dwProperty);
+            return dwResult;
+        }
+    }
+}
+
+
+DWORD
+tap_create_adapter(
+    _In_opt_ HWND hwndParent,
+    _In_opt_ LPCTSTR szDeviceDescription,
+    _In_ LPCTSTR szHwId,
+    _Inout_ LPBOOL pbRebootRequired,
+    _Out_ LPGUID pguidAdapter)
+{
+    DWORD dwResult;
+
+    if (szHwId == NULL
+        || pbRebootRequired == NULL
+        || pguidAdapter == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Create an empty device info set for network adapter device class. */
+    HDEVINFO hDevInfoList = SetupDiCreateDeviceInfoList(&GUID_DEVCLASS_NET, hwndParent);
+    if (hDevInfoList == INVALID_HANDLE_VALUE)
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiCreateDeviceInfoList failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Get the device class name from GUID. */
+    TCHAR szClassName[MAX_CLASS_NAME_LEN];
+    if (!SetupDiClassNameFromGuid(
+            &GUID_DEVCLASS_NET,
+            szClassName,
+            _countof(szClassName),
+            NULL))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiClassNameFromGuid failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Create a new device info element and add it to the device info set. */
+    SP_DEVINFO_DATA devinfo_data = { .cbSize = sizeof(SP_DEVINFO_DATA) };
+    if (!SetupDiCreateDeviceInfo(
+            hDevInfoList,
+            szClassName,
+            &GUID_DEVCLASS_NET,
+            szDeviceDescription,
+            hwndParent,
+            DICD_GENERATE_ID,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiCreateDeviceInfo failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Set a device information element as the selected member of a device information set. */
+    if (!SetupDiSetSelectedDevice(
+            hDevInfoList,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiSetSelectedDevice failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Set Plug&Play device hardware ID property. */
+    if (!SetupDiSetDeviceRegistryProperty(
+            hDevInfoList,
+            &devinfo_data,
+            SPDRP_HARDWAREID,
+            (const BYTE *)szHwId, (DWORD)((_tcslen(szHwId) + 1) * sizeof(TCHAR))))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiSetDeviceRegistryProperty failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Search for the driver. */
+    if (!SetupDiBuildDriverInfoList(
+            hDevInfoList,
+            &devinfo_data,
+            SPDIT_CLASSDRIVER))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiBuildDriverInfoList failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+    DWORDLONG dwlDriverVersion = 0;
+    DWORD drvinfo_detail_data_size = sizeof(SP_DRVINFO_DETAIL_DATA) + 0x100;
+    SP_DRVINFO_DETAIL_DATA *drvinfo_detail_data = (SP_DRVINFO_DETAIL_DATA *)malloc(drvinfo_detail_data_size);
+    if (drvinfo_detail_data == NULL)
+    {
+        msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, drvinfo_detail_data_size);
+        dwResult = ERROR_OUTOFMEMORY; goto cleanup_DriverInfoList;
+    }
+
+    for (DWORD dwIndex = 0;; dwIndex++)
+    {
+        /* Get a driver from the list. */
+        SP_DRVINFO_DATA drvinfo_data = { .cbSize = sizeof(SP_DRVINFO_DATA) };
+        if (!SetupDiEnumDriverInfo(
+                hDevInfoList,
+                &devinfo_data,
+                SPDIT_CLASSDRIVER,
+                dwIndex,
+                &drvinfo_data))
+        {
+            if (GetLastError() == ERROR_NO_MORE_ITEMS)
+            {
+                break;
+            }
+            else
+            {
+                /* Something is wrong with this driver. Skip it. */
+                msg(M_WARN | M_ERRNO, "%s: SetupDiEnumDriverInfo(%u) failed", __FUNCTION__, dwIndex);
+                continue;
+            }
+        }
+
+        /* Get driver info details. */
+        DWORD dwSize;
+        drvinfo_detail_data->cbSize = sizeof(SP_DRVINFO_DETAIL_DATA);
+        if (!SetupDiGetDriverInfoDetail(
+                hDevInfoList,
+                &devinfo_data,
+                &drvinfo_data,
+                drvinfo_detail_data,
+                drvinfo_detail_data_size,
+                &dwSize))
+        {
+            if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
+            {
+                /* (Re)allocate buffer. */
+                if (drvinfo_detail_data)
+                {
+                    free(drvinfo_detail_data);
+                }
+
+                drvinfo_detail_data_size = dwSize;
+                drvinfo_detail_data = (SP_DRVINFO_DETAIL_DATA *)malloc(drvinfo_detail_data_size);
+                if (drvinfo_detail_data == NULL)
+                {
+                    msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, drvinfo_detail_data_size);
+                    dwResult = ERROR_OUTOFMEMORY; goto cleanup_DriverInfoList;
+                }
+
+                /* Re-get driver info details. */
+                drvinfo_detail_data->cbSize = sizeof(SP_DRVINFO_DETAIL_DATA);
+                if (!SetupDiGetDriverInfoDetail(
+                        hDevInfoList,
+                        &devinfo_data,
+                        &drvinfo_data,
+                        drvinfo_detail_data,
+                        drvinfo_detail_data_size,
+                        &dwSize))
+                {
+                    /* Something is wrong with this driver. Skip it. */
+                    continue;
+                }
+            }
+            else
+            {
+                /* Something is wrong with this driver. Skip it. */
+                msg(M_WARN | M_ERRNO, "%s: SetupDiGetDriverInfoDetail(\"%hs\") failed", __FUNCTION__, drvinfo_data.Description);
+                continue;
+            }
+        }
+
+        /* Check the driver version and hardware ID. */
+        if (dwlDriverVersion < drvinfo_data.DriverVersion
+            && drvinfo_detail_data->HardwareID
+            && _tcszistr(drvinfo_detail_data->HardwareID, szHwId))
+        {
+            /* Newer version and matching hardware ID found. Select the driver. */
+            if (!SetupDiSetSelectedDriver(
+                    hDevInfoList,
+                    &devinfo_data,
+                    &drvinfo_data))
+            {
+                /* Something is wrong with this driver. Skip it. */
+                msg(M_WARN | M_ERRNO, "%s: SetupDiSetSelectedDriver(\"%hs\") failed", __FUNCTION__, drvinfo_data.Description);
+                continue;
+            }
+
+            dwlDriverVersion = drvinfo_data.DriverVersion;
+        }
+    }
+    if (drvinfo_detail_data)
+    {
+        free(drvinfo_detail_data);
+    }
+
+    if (dwlDriverVersion == 0)
+    {
+        dwResult = ERROR_NOT_FOUND;
+        msg(M_NONFATAL, "%s: No driver for device \"%" PRIsLPTSTR "\" installed.", __FUNCTION__, szHwId);
+        goto cleanup_DriverInfoList;
+    }
+
+    /* Call appropriate class installer. */
+    if (!SetupDiCallClassInstaller(
+            DIF_REGISTERDEVICE,
+            hDevInfoList,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiCallClassInstaller(DIF_REGISTERDEVICE) failed", __FUNCTION__);
+        goto cleanup_DriverInfoList;
+    }
+
+    /* Register device co-installers if any. */
+    if (!SetupDiCallClassInstaller(
+            DIF_REGISTER_COINSTALLERS,
+            hDevInfoList,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_WARN | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_REGISTER_COINSTALLERS) failed", __FUNCTION__);
+    }
+
+    /* Install adapters if any. */
+    if (!SetupDiCallClassInstaller(
+            DIF_INSTALLINTERFACES,
+            hDevInfoList,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_WARN | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_INSTALLINTERFACES) failed", __FUNCTION__);
+    }
+
+    /* Install the device. */
+    if (!SetupDiCallClassInstaller(
+            DIF_INSTALLDEVICE,
+            hDevInfoList,
+            &devinfo_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_INSTALLDEVICE) failed", __FUNCTION__);
+        goto cleanup_remove_device;
+    }
+
+    /* Check if a system reboot is required. (Ignore errors) */
+    check_reboot(hDevInfoList, &devinfo_data, pbRebootRequired);
+
+    /* Get network adapter ID from registry. Retry for max 30sec. */
+    dwResult = get_net_adapter_guid(hDevInfoList, &devinfo_data, 30, pguidAdapter);
+
+cleanup_remove_device:
+    if (dwResult != ERROR_SUCCESS)
+    {
+        /* The adapter was installed. But, the adapter ID was unobtainable. Clean-up. */
+        SP_REMOVEDEVICE_PARAMS removedevice_params =
+        {
+            .ClassInstallHeader =
+            {
+                .cbSize = sizeof(SP_CLASSINSTALL_HEADER),
+                .InstallFunction = DIF_REMOVE,
+            },
+            .Scope = DI_REMOVEDEVICE_GLOBAL,
+            .HwProfile = 0,
+        };
+
+        /* Set class installer parameters for DIF_REMOVE. */
+        if (SetupDiSetClassInstallParams(
+                hDevInfoList,
+                &devinfo_data,
+                &removedevice_params.ClassInstallHeader,
+                sizeof(SP_REMOVEDEVICE_PARAMS)))
+        {
+            /* Call appropriate class installer. */
+            if (SetupDiCallClassInstaller(
+                    DIF_REMOVE,
+                    hDevInfoList,
+                    &devinfo_data))
+            {
+                /* Check if a system reboot is required. */
+                check_reboot(hDevInfoList, &devinfo_data, pbRebootRequired);
+            }
+            else
+            {
+                msg(M_NONFATAL | M_ERRNO, "%s: SetupDiCallClassInstaller(DIF_REMOVE) failed", __FUNCTION__);
+            }
+        }
+        else
+        {
+            msg(M_NONFATAL | M_ERRNO, "%s: SetupDiSetClassInstallParams failed", __FUNCTION__);
+        }
+    }
+
+cleanup_DriverInfoList:
+    SetupDiDestroyDriverInfoList(
+        hDevInfoList,
+        &devinfo_data,
+        SPDIT_CLASSDRIVER);
+
+cleanup_hDevInfoList:
+    SetupDiDestroyDeviceInfoList(hDevInfoList);
+    return dwResult;
+}
+
+
+/**
+ * Performs a given task on an adapter.
+ *
+ * @param hwndParent    A handle to the top-level window to use for any user adapter that is
+ *                      related to non-device-specific actions (such as a select-device dialog
+ *                      box that uses the global class driver list). This handle is optional
+ *                      and can be NULL. If a specific top-level window is not required, set
+ *                      hwndParent to NULL.
+ *
+ * @param pguidAdapter  A pointer to GUID that contains network adapter ID.
+ *
+ * @param funcOperation  A pointer for the function to perform specific task on the adapter.
+ *
+ * @param pbRebootRequired  A pointer to a BOOL flag. If the device requires a system restart,
+ *                      this flag is set to TRUE. Otherwise, the flag is left unmodified. This
+ *                      allows the flag to be globally initialized to FALSE and reused for multiple
+ *                      adapter manipulations.
+ *
+ * @return ERROR_SUCCESS on success; Win32 error code otherwise
+ **/
+static DWORD
+execute_on_first_adapter(
+    _In_opt_ HWND hwndParent,
+    _In_ LPCGUID pguidAdapter,
+    _In_ devop_func_t funcOperation,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    DWORD dwResult;
+
+    if (pguidAdapter == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Create a list of network devices. */
+    HDEVINFO hDevInfoList = SetupDiGetClassDevsEx(
+        &GUID_DEVCLASS_NET,
+        NULL,
+        hwndParent,
+        DIGCF_PRESENT,
+        NULL,
+        NULL,
+        NULL);
+    if (hDevInfoList == INVALID_HANDLE_VALUE)
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiGetClassDevsEx failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Retrieve information associated with a device information set. */
+    SP_DEVINFO_LIST_DETAIL_DATA devinfo_list_detail_data = { .cbSize = sizeof(SP_DEVINFO_LIST_DETAIL_DATA) };
+    if (!SetupDiGetDeviceInfoListDetail(hDevInfoList, &devinfo_list_detail_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiGetDeviceInfoListDetail failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Iterate. */
+    for (DWORD dwIndex = 0;; dwIndex++)
+    {
+        /* Get the device from the list. */
+        SP_DEVINFO_DATA devinfo_data = { .cbSize = sizeof(SP_DEVINFO_DATA) };
+        if (!SetupDiEnumDeviceInfo(
+                hDevInfoList,
+                dwIndex,
+                &devinfo_data))
+        {
+            if (GetLastError() == ERROR_NO_MORE_ITEMS)
+            {
+                LPOLESTR szAdapterId = NULL;
+                StringFromIID((REFIID)pguidAdapter, &szAdapterId);
+                msg(M_NONFATAL, "%s: Adapter %" PRIsLPOLESTR " not found", __FUNCTION__, szAdapterId);
+                CoTaskMemFree(szAdapterId);
+                dwResult = ERROR_FILE_NOT_FOUND;
+                goto cleanup_hDevInfoList;
+            }
+            else
+            {
+                /* Something is wrong with this device. Skip it. */
+                msg(M_WARN | M_ERRNO, "%s: SetupDiEnumDeviceInfo(%u) failed", __FUNCTION__, dwIndex);
+                continue;
+            }
+        }
+
+        /* Get adapter GUID. */
+        GUID guidAdapter;
+        dwResult = get_net_adapter_guid(hDevInfoList, &devinfo_data, 1, &guidAdapter);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            /* Something is wrong with this device. Skip it. */
+            continue;
+        }
+
+        /* Compare GUIDs. */
+        if (memcmp(pguidAdapter, &guidAdapter, sizeof(GUID)) == 0)
+        {
+            dwResult = funcOperation(hDevInfoList, &devinfo_data, pbRebootRequired);
+            break;
+        }
+    }
+
+cleanup_hDevInfoList:
+    SetupDiDestroyDeviceInfoList(hDevInfoList);
+    return dwResult;
+}
+
+
+DWORD
+tap_delete_adapter(
+    _In_opt_ HWND hwndParent,
+    _In_ LPCGUID pguidAdapter,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    return execute_on_first_adapter(hwndParent, pguidAdapter, delete_device, pbRebootRequired);
+}
+
+
+DWORD
+tap_enable_adapter(
+    _In_opt_ HWND hwndParent,
+    _In_ LPCGUID pguidAdapter,
+    _In_ BOOL bEnable,
+    _Inout_ LPBOOL pbRebootRequired)
+{
+    return execute_on_first_adapter(hwndParent, pguidAdapter, bEnable ? enable_device : disable_device, pbRebootRequired);
+}
+
+/* stripped version of ExecCommand in interactive.c */
+static DWORD
+ExecCommand(const WCHAR* cmdline)
+{
+    DWORD exit_code;
+    STARTUPINFOW si;
+    PROCESS_INFORMATION pi;
+    DWORD proc_flags = CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT;
+    WCHAR* cmdline_dup = NULL;
+
+    ZeroMemory(&si, sizeof(si));
+    ZeroMemory(&pi, sizeof(pi));
+
+    si.cb = sizeof(si);
+
+    /* CreateProcess needs a modifiable cmdline: make a copy */
+    cmdline_dup = _wcsdup(cmdline);
+    if (cmdline_dup && CreateProcessW(NULL, cmdline_dup, NULL, NULL, FALSE,
+        proc_flags, NULL, NULL, &si, &pi))
+    {
+        WaitForSingleObject(pi.hProcess, INFINITE);
+        if (!GetExitCodeProcess(pi.hProcess, &exit_code))
+        {
+            exit_code = GetLastError();
+        }
+
+        CloseHandle(pi.hProcess);
+        CloseHandle(pi.hThread);
+    }
+    else
+    {
+        exit_code = GetLastError();
+    }
+
+    free(cmdline_dup);
+    return exit_code;
+}
+
+DWORD
+tap_set_adapter_name(
+    _In_ LPCGUID pguidAdapter,
+    _In_ LPCTSTR szName)
+{
+    DWORD dwResult;
+
+    if (pguidAdapter == NULL || szName == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Get the device class GUID as string. */
+    LPOLESTR szDevClassNetId = NULL;
+    StringFromIID((REFIID)&GUID_DEVCLASS_NET, &szDevClassNetId);
+
+    /* Get the adapter GUID as string. */
+    LPOLESTR szAdapterId = NULL;
+    StringFromIID((REFIID)pguidAdapter, &szAdapterId);
+
+    /* Render registry key path. */
+    TCHAR szRegKey[ADAPTER_REGKEY_PATH_MAX];
+    _stprintf_s(
+        szRegKey, _countof(szRegKey),
+        szAdapterRegKeyPathTemplate,
+        szDevClassNetId,
+        szAdapterId);
+
+    /* Open network adapter registry key. */
+    HKEY hKey = NULL;
+    dwResult = RegOpenKeyEx(
+        HKEY_LOCAL_MACHINE,
+        szRegKey,
+        0,
+        KEY_QUERY_VALUE,
+        &hKey);
+    if (dwResult != ERROR_SUCCESS)
+    {
+        SetLastError(dwResult); /* MSDN does not mention RegOpenKeyEx() to set GetLastError(). But we do have an error code. Set last error manually. */
+        msg(M_NONFATAL | M_ERRNO, "%s: RegOpenKeyEx(HKLM, \"%" PRIsLPTSTR "\") failed", __FUNCTION__, szRegKey);
+        goto cleanup_szAdapterId;
+    }
+
+    LPTSTR szOldName = NULL;
+    dwResult = get_reg_string(hKey, TEXT("Name"), &szOldName);
+    if (dwResult != ERROR_SUCCESS)
+    {
+        SetLastError(dwResult);
+        msg(M_NONFATAL | M_ERRNO, "%s: Error reading adapter name", __FUNCTION__);
+        goto cleanup_hKey;
+    }
+
+    /* rename adapter via netsh call */
+    const TCHAR* szFmt = _T("netsh interface set interface name=\"%s\" newname=\"%s\"");
+    size_t ncmdline = _tcslen(szFmt) + _tcslen(szOldName) + _tcslen(szName) + 1;
+    WCHAR* szCmdLine = malloc(ncmdline * sizeof(TCHAR));
+    _stprintf_s(szCmdLine, ncmdline, szFmt, szOldName, szName);
+
+    free(szOldName);
+
+    dwResult = ExecCommand(szCmdLine);
+    free(szCmdLine);
+
+    if (dwResult != ERROR_SUCCESS)
+    {
+        SetLastError(dwResult);
+        msg(M_NONFATAL | M_ERRNO, "%s: Error renaming adapter", __FUNCTION__);
+        goto cleanup_hKey;
+    }
+
+cleanup_hKey:
+    RegCloseKey(hKey);
+cleanup_szAdapterId:
+    CoTaskMemFree(szAdapterId);
+    CoTaskMemFree(szDevClassNetId);
+    return dwResult;
+}
+
+
+DWORD
+tap_list_adapters(
+    _In_opt_ HWND hwndParent,
+    _In_opt_ LPCTSTR szzHwIDs,
+    _Out_ struct tap_adapter_node **ppAdapter)
+{
+    DWORD dwResult;
+
+    if (ppAdapter == NULL)
+    {
+        return ERROR_BAD_ARGUMENTS;
+    }
+
+    /* Create a list of network devices. */
+    HDEVINFO hDevInfoList = SetupDiGetClassDevsEx(
+        &GUID_DEVCLASS_NET,
+        NULL,
+        hwndParent,
+        DIGCF_PRESENT,
+        NULL,
+        NULL,
+        NULL);
+    if (hDevInfoList == INVALID_HANDLE_VALUE)
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiGetClassDevsEx failed", __FUNCTION__);
+        return dwResult;
+    }
+
+    /* Retrieve information associated with a device information set. */
+    SP_DEVINFO_LIST_DETAIL_DATA devinfo_list_detail_data = { .cbSize = sizeof(SP_DEVINFO_LIST_DETAIL_DATA) };
+    if (!SetupDiGetDeviceInfoListDetail(hDevInfoList, &devinfo_list_detail_data))
+    {
+        dwResult = GetLastError();
+        msg(M_NONFATAL, "%s: SetupDiGetDeviceInfoListDetail failed", __FUNCTION__);
+        goto cleanup_hDevInfoList;
+    }
+
+    /* Get the device class GUID as string. */
+    LPOLESTR szDevClassNetId = NULL;
+    StringFromIID((REFIID)&GUID_DEVCLASS_NET, &szDevClassNetId);
+
+    /* Iterate. */
+    *ppAdapter = NULL;
+    struct tap_adapter_node *pAdapterTail = NULL;
+    for (DWORD dwIndex = 0;; dwIndex++)
+    {
+        /* Get the device from the list. */
+        SP_DEVINFO_DATA devinfo_data = { .cbSize = sizeof(SP_DEVINFO_DATA) };
+        if (!SetupDiEnumDeviceInfo(
+                hDevInfoList,
+                dwIndex,
+                &devinfo_data))
+        {
+            if (GetLastError() == ERROR_NO_MORE_ITEMS)
+            {
+                break;
+            }
+            else
+            {
+                /* Something is wrong with this device. Skip it. */
+                msg(M_WARN | M_ERRNO, "%s: SetupDiEnumDeviceInfo(%u) failed", __FUNCTION__, dwIndex);
+                continue;
+            }
+        }
+
+        /* Get device hardware ID(s). */
+        DWORD dwDataType = REG_NONE;
+        LPTSTR szzDeviceHardwareIDs = NULL;
+        dwResult = get_device_reg_property(
+            hDevInfoList,
+            &devinfo_data,
+            SPDRP_HARDWAREID,
+            &dwDataType,
+            (LPVOID)&szzDeviceHardwareIDs);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            /* Something is wrong with this device. Skip it. */
+            continue;
+        }
+
+        /* Check that hardware ID is REG_SZ/REG_MULTI_SZ, and optionally if it matches ours. */
+        if (dwDataType == REG_SZ)
+        {
+            if (szzHwIDs && !_tcszistr(szzHwIDs, szzDeviceHardwareIDs))
+            {
+                /* This is not our device. Skip it. */
+                goto cleanup_szzDeviceHardwareIDs;
+            }
+        }
+        else if (dwDataType == REG_MULTI_SZ)
+        {
+            if (szzHwIDs)
+            {
+                for (LPTSTR s = szzDeviceHardwareIDs;; s += _tcslen(s) + 1)
+                {
+                    if (s[0] == 0)
+                    {
+                        /* This is not our device. Skip it. */
+                        goto cleanup_szzDeviceHardwareIDs;
+                    }
+                    else if (_tcszistr(szzHwIDs, s))
+                    {
+                        /* This is our device. */
+                        break;
+                    }
+                }
+            }
+        }
+        else
+        {
+            /* Unexpected hardware ID format. Skip device. */
+            goto cleanup_szzDeviceHardwareIDs;
+        }
+
+        /* Get adapter GUID. */
+        GUID guidAdapter;
+        dwResult = get_net_adapter_guid(hDevInfoList, &devinfo_data, 1, &guidAdapter);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            /* Something is wrong with this device. Skip it. */
+            goto cleanup_szzDeviceHardwareIDs;
+        }
+
+        /* Get the adapter GUID as string. */
+        LPOLESTR szAdapterId = NULL;
+        StringFromIID((REFIID)&guidAdapter, &szAdapterId);
+
+        /* Render registry key path. */
+        TCHAR szRegKey[ADAPTER_REGKEY_PATH_MAX];
+        _stprintf_s(
+            szRegKey, _countof(szRegKey),
+            szAdapterRegKeyPathTemplate,
+            szDevClassNetId,
+            szAdapterId);
+
+        /* Open network adapter registry key. */
+        HKEY hKey = NULL;
+        dwResult = RegOpenKeyEx(
+            HKEY_LOCAL_MACHINE,
+            szRegKey,
+            0,
+            KEY_READ,
+            &hKey);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            SetLastError(dwResult); /* MSDN does not mention RegOpenKeyEx() to set GetLastError(). But we do have an error code. Set last error manually. */
+            msg(M_WARN | M_ERRNO, "%s: RegOpenKeyEx(HKLM, \"%" PRIsLPTSTR "\") failed", __FUNCTION__, szRegKey);
+            goto cleanup_szAdapterId;
+        }
+
+        /* Read adapter name. */
+        LPTSTR szName = NULL;
+        dwResult = get_reg_string(
+            hKey,
+            TEXT("Name"),
+            &szName);
+        if (dwResult != ERROR_SUCCESS)
+        {
+            SetLastError(dwResult);
+            msg(M_WARN | M_ERRNO, "%s: Cannot determine %" PRIsLPOLESTR " adapter name", __FUNCTION__, szAdapterId);
+            goto cleanup_hKey;
+        }
+
+        /* Append to the list. */
+        size_t hwid_size = (_tcszlen(szzDeviceHardwareIDs) + 1) * sizeof(TCHAR);
+        size_t name_size = (_tcslen(szName) + 1) * sizeof(TCHAR);
+        struct tap_adapter_node *node = (struct tap_adapter_node *)malloc(sizeof(struct tap_adapter_node) + hwid_size + name_size);
+        if (node == NULL)
+        {
+            msg(M_FATAL, "%s: malloc(%u) failed", __FUNCTION__, sizeof(struct tap_adapter_node) + hwid_size + name_size);
+            dwResult = ERROR_OUTOFMEMORY; goto cleanup_szName;
+        }
+
+        memcpy(&node->guid, &guidAdapter, sizeof(GUID));
+        node->szzHardwareIDs = (LPTSTR)(node + 1);
+        memcpy(node->szzHardwareIDs, szzDeviceHardwareIDs, hwid_size);
+        node->szName = (LPTSTR)((LPBYTE)node->szzHardwareIDs + hwid_size);
+        memcpy(node->szName, szName, name_size);
+        node->pNext = NULL;
+        if (pAdapterTail)
+        {
+            pAdapterTail->pNext = node;
+            pAdapterTail = node;
+        }
+        else
+        {
+            *ppAdapter = pAdapterTail = node;
+        }
+
+cleanup_szName:
+        free(szName);
+cleanup_hKey:
+        RegCloseKey(hKey);
+cleanup_szAdapterId:
+        CoTaskMemFree(szAdapterId);
+cleanup_szzDeviceHardwareIDs:
+        free(szzDeviceHardwareIDs);
+    }
+
+    dwResult = ERROR_SUCCESS;
+
+    CoTaskMemFree(szDevClassNetId);
+cleanup_hDevInfoList:
+    SetupDiDestroyDeviceInfoList(hDevInfoList);
+    return dwResult;
+}
+
+
+void
+tap_free_adapter_list(
+    _In_ struct tap_adapter_node *pAdapterList)
+{
+    /* Iterate over all nodes of the list. */
+    while (pAdapterList)
+    {
+        struct tap_adapter_node *node = pAdapterList;
+        pAdapterList = pAdapterList->pNext;
+
+        /* Free the adapter node. */
+        free(node);
+    }
+}