#include "WinDNSHelper.hpp"
#include <comdef.h>
#include <WbemIdl.h>
#include <vector>
#include <string>
#include <sstream>
#include <strsafe.h>
#define MAX_KEY_LENGTH 255
#define MAX_VALUE_NAME 16383
namespace ZeroTier
{
BOOL RegDelnodeRecurse(HKEY hKeyRoot, LPTSTR lpSubKey)
{
LPTSTR lpEnd;
LONG lResult;
DWORD dwSize;
TCHAR szName[MAX_PATH];
HKEY hKey;
FILETIME ftWrite;
// First, see if we can delete the key without having
// to recurse.
lResult = RegDeleteKey(hKeyRoot, lpSubKey);
if (lResult == ERROR_SUCCESS)
return TRUE;
lResult = RegOpenKeyEx(hKeyRoot, lpSubKey, 0, KEY_READ, &hKey);
if (lResult != ERROR_SUCCESS)
{
if (lResult == ERROR_FILE_NOT_FOUND) {
return TRUE;
}
else {
return FALSE;
}
}
// Check for an ending slash and add one if it is missing.
lpEnd = lpSubKey + lstrlen(lpSubKey);
if (*(lpEnd - 1) != TEXT('\\'))
{
*lpEnd = TEXT('\\');
lpEnd++;
*lpEnd = TEXT('\0');
}
// Enumerate the keys
dwSize = MAX_PATH;
lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, NULL,
NULL, NULL, &ftWrite);
if (lResult == ERROR_SUCCESS)
{
do {
*lpEnd = TEXT('\0');
StringCchCat(lpSubKey, MAX_PATH * 2, szName);
if (!RegDelnodeRecurse(hKeyRoot, lpSubKey)) {
break;
}
dwSize = MAX_PATH;
lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, NULL,
NULL, NULL, &ftWrite);
} while (lResult == ERROR_SUCCESS);
}
lpEnd--;
*lpEnd = TEXT('\0');
RegCloseKey(hKey);
// Try again to delete the key.
lResult = RegDeleteKey(hKeyRoot, lpSubKey);
if (lResult == ERROR_SUCCESS)
return TRUE;
return FALSE;
}
//*************************************************************
//
// RegDelnode()
//
// Purpose: Deletes a registry key and all its subkeys / values.
//
// Parameters: hKeyRoot - Root key
// lpSubKey - SubKey to delete
//
// Return: TRUE if successful.
// FALSE if an error occurs.
//
//*************************************************************
BOOL RegDelnode(HKEY hKeyRoot, LPCTSTR lpSubKey)
{
TCHAR szDelKey[MAX_PATH * 2];
StringCchCopy(szDelKey, MAX_PATH * 2, lpSubKey);
return RegDelnodeRecurse(hKeyRoot, szDelKey);
}
std::vector<std::string> getSubKeys(const char* key)
{
std::vector<std::string> subkeys;
HKEY hKey;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,
key,
0,
KEY_READ,
&hKey) == ERROR_SUCCESS) {
TCHAR achKey[MAX_KEY_LENGTH]; // buffer for subkey name
DWORD cbName; // size of name string
TCHAR achClass[MAX_PATH] = TEXT(""); // buffer for class name
DWORD cchClassName = MAX_PATH; // size of class string
DWORD cSubKeys = 0; // number of subkeys
DWORD cbMaxSubKey; // longest subkey size
DWORD cchMaxClass; // longest class string
DWORD cValues; // number of values for key
DWORD cchMaxValue; // longest value name
DWORD cbMaxValueData; // longest value data
DWORD cbSecurityDescriptor; // size of security descriptor
FILETIME ftLastWriteTime; // last write time
DWORD i, retCode;
TCHAR achValue[MAX_VALUE_NAME];
DWORD cchValue = MAX_VALUE_NAME;
retCode = RegQueryInfoKey(
hKey, // key handle
achClass, // buffer for class name
&cchClassName, // size of class string
NULL, // reserved
&cSubKeys, // number of subkeys
&cbMaxSubKey, // longest subkey size
&cchMaxClass, // longest class string
&cValues, // number of values for this key
&cchMaxValue, // longest value name
&cbMaxValueData, // longest value data
&cbSecurityDescriptor, // security descriptor
&ftLastWriteTime); // last write time
for (i = 0; i < cSubKeys; ++i) {
cbName = MAX_KEY_LENGTH;
retCode = RegEnumKeyEx(
hKey,
i,
achKey,
&cbName,
NULL,
NULL,
NULL,
&ftLastWriteTime);
if (retCode == ERROR_SUCCESS) {
subkeys.push_back(achKey);
}
}
}
RegCloseKey(hKey);
return subkeys;
}
std::vector<std::string> getValueList(const char* key) {
std::vector<std::string> values;
HKEY hKey;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,
key,
0,
KEY_READ,
&hKey) == ERROR_SUCCESS) {
TCHAR achKey[MAX_KEY_LENGTH]; // buffer for subkey name
DWORD cbName; // size of name string
TCHAR achClass[MAX_PATH] = TEXT(""); // buffer for class name
DWORD cchClassName = MAX_PATH; // size of class string
DWORD cSubKeys = 0; // number of subkeys
DWORD cbMaxSubKey; // longest subkey size
DWORD cchMaxClass; // longest class string
DWORD cValues; // number of values for key
DWORD cchMaxValue; // longest value name
DWORD cbMaxValueData; // longest value data
DWORD cbSecurityDescriptor; // size of security descriptor
FILETIME ftLastWriteTime; // last write time
DWORD i, retCode;
TCHAR achValue[MAX_VALUE_NAME];
DWORD cchValue = MAX_VALUE_NAME;
retCode = RegQueryInfoKey(
hKey, // key handle
achClass, // buffer for class name
&cchClassName, // size of class string
NULL, // reserved
&cSubKeys, // number of subkeys
&cbMaxSubKey, // longest subkey size
&cchMaxClass, // longest class string
&cValues, // number of values for this key
&cchMaxValue, // longest value name
&cbMaxValueData, // longest value data
&cbSecurityDescriptor, // security descriptor
&ftLastWriteTime); // last write time
for (i = 0, retCode = ERROR_SUCCESS; i < cValues; ++i) {
cchValue = MAX_VALUE_NAME;
achValue[0] = '\0';
retCode = RegEnumValue(
hKey,
i,
achValue,
&cchValue,
NULL,
NULL,
NULL,
NULL);
if (retCode == ERROR_SUCCESS) {
values.push_back(achValue);
}
}
}
RegCloseKey(hKey);
return values;
}
std::pair<bool, std::string> WinDNSHelper::hasDNSConfig(uint64_t nwid)
{
char networkStr[20] = { 0 };
sprintf(networkStr, "%.16llx", nwid);
const char* baseKey = "SYSTEM\\CurrentControlSet\\Services\\Dnscache\\Parameters\\DnsPolicyConfig";
auto subkeys = getSubKeys(baseKey);
for (auto it = subkeys.begin(); it != subkeys.end(); ++it) {
char sub[MAX_KEY_LENGTH] = { 0 };
sprintf(sub, "%s\\%s", baseKey, it->c_str());
auto dnsRecords = getValueList(sub);
for (auto it2 = dnsRecords.begin(); it2 != dnsRecords.end(); ++it2) {
if ((*it2) == "Comment") {
HKEY hKey;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE,
sub,
0,
KEY_READ,
&hKey) == ERROR_SUCCESS) {
char buf[16384] = { 0 };
DWORD size = sizeof(buf);
DWORD retCode = RegGetValueA(
HKEY_LOCAL_MACHINE,
sub,
it2->c_str(),
RRF_RT_REG_SZ,
NULL,
&buf,
&size);
if (retCode == ERROR_SUCCESS) {
if (std::string(networkStr) == std::string(buf)) {
RegCloseKey(hKey);
return std::make_pair(true, std::string(sub));
}
}
else {
}
}
RegCloseKey(hKey);
}
}
}
return std::make_pair(false, std::string());
}
void WinDNSHelper::setDNS(uint64_t nwid, const char* domain, const std::vector<InetAddress>& servers)
{
auto hasConfig = hasDNSConfig(nwid);
std::stringstream ss;
for (auto it = servers.begin(); it != servers.end(); ++it) {
char ipaddr[256] = { 0 };
ss << it->toIpString(ipaddr);
if ((it + 1) != servers.end()) {
ss << ";";
}
}
std::string serverValue = ss.str();
if (hasConfig.first) {
// update existing config
HKEY dnsKey;
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, hasConfig.second.c_str(), 0, KEY_READ | KEY_WRITE, &dnsKey) == ERROR_SUCCESS) {
auto retCode = RegSetKeyValueA(dnsKey, NULL, "GenericDNSServers", REG_SZ, serverValue.data(), (DWORD)serverValue.length());
if (retCode != ERROR_SUCCESS) {
fprintf(stderr, "Error writing dns servers: %d\n", retCode);
}
}
} else {
// add new config
const char* baseKey = "SYSTEM\\CurrentControlSet\\Services\\Dnscache\\Parameters\\DnsPolicyConfig";
GUID guid;
CoCreateGuid(&guid);
wchar_t guidTmp[128] = { 0 };
char guidStr[128] = { 0 };
StringFromGUID2(guid, guidTmp, 128);
wcstombs(guidStr, guidTmp, 128);
char fullKey[MAX_KEY_LENGTH] = { 0 };
sprintf(fullKey, "%s\\%s", baseKey, guidStr);
HKEY dnsKey;
RegCreateKeyA(HKEY_LOCAL_MACHINE, fullKey, &dnsKey);
if (RegOpenKeyExA(HKEY_LOCAL_MACHINE, fullKey, 0, KEY_READ | KEY_WRITE, &dnsKey) == ERROR_SUCCESS) {
char nwString[32] = { 0 };
sprintf(nwString, "%.16llx", nwid);
RegSetKeyValueA(dnsKey, NULL, "Comment", REG_SZ, nwString, strlen(nwString));
DWORD configOpts = 8;
RegSetKeyValueA(dnsKey, NULL, "ConfigOptions", REG_DWORD, &configOpts, sizeof(DWORD));
RegSetKeyValueA(dnsKey, NULL, "DisplayName", REG_SZ, "", 0);
RegSetKeyValueA(dnsKey, NULL, "GenericDNSServers", REG_SZ, serverValue.data(), serverValue.length());
RegSetKeyValueA(dnsKey, NULL, "IPSECCARestriction", REG_SZ, "", 0);
std::string d = "." + std::string(domain);
RegSetKeyValueA(dnsKey, NULL, "Name", REG_MULTI_SZ, d.data(), d.length());
DWORD version = 2;
RegSetKeyValueA(dnsKey, NULL, "Version", REG_DWORD, &version, sizeof(DWORD));
}
}
}
void WinDNSHelper::removeDNS(uint64_t nwid)
{
auto hasConfig = hasDNSConfig(nwid);
if (hasConfig.first) {
RegDelnode(HKEY_LOCAL_MACHINE, hasConfig.second.c_str());
}
}
}