static int Lget_nameservers(lua_State *L) {
char stack_buffer[1024]; // stack allocated buffer
IP4_ARRAY* ips = (IP4_ARRAY*) stack_buffer;
DWORD len = sizeof(stack_buffer);
DNS_STATUS status;
status = DnsQueryConfig(DnsConfigDnsServerList, FALSE, NULL, NULL, ips, &len);
if (status == 0) {
DWORD i;
lua_createtable(L, ips->AddrCount, 0);
for (i = 0; i < ips->AddrCount; i++) {
DWORD ip = ips->AddrArray[i];
char ip_str[16] = "";
sprintf_s(ip_str, sizeof(ip_str), "%d.%d.%d.%d", (ip >> 0) & 255, (ip >> 8) & 255, (ip >> 16) & 255, (ip >> 24) & 255);
lua_pushstring(L, ip_str);
lua_rawseti(L, -2, i+1);
}
return 1;
} else {
HRESULT HostDnsServiceWin::updateInfo()
{
HostDnsInformation info;
LONG lrc;
int rc;
std::string strDomain;
std::string strSearchList; /* NB: comma separated, no spaces */
/*
* We ignore "DhcpDomain" key here since it's not stable. If
* there are two active interfaces that use DHCP (in particular
* when host uses OpenVPN) then DHCP ACKs will take turns updating
* that key. Instead we call GetAdaptersAddresses() below (which
* is what ipconfig.exe seems to do).
*/
for (DWORD regIndex = 0; /**/; ++regIndex) {
char keyName[256];
DWORD cbKeyName = sizeof(keyName);
DWORD keyType = 0;
char keyData[1024];
DWORD cbKeyData = sizeof(keyData);
lrc = RegEnumValueA(m->hKeyTcpipParameters, regIndex,
keyName, &cbKeyName, 0,
&keyType, (LPBYTE)keyData, &cbKeyData);
if (lrc == ERROR_NO_MORE_ITEMS)
break;
if (lrc == ERROR_MORE_DATA) /* buffer too small; handle? */
continue;
if (lrc != ERROR_SUCCESS)
{
LogRel2(("HostDnsServiceWin: RegEnumValue error %d\n", (int)lrc));
return E_FAIL;
}
if (keyType != REG_SZ)
continue;
if (cbKeyData > 0 && keyData[cbKeyData - 1] == '\0')
--cbKeyData; /* don't count trailing NUL if present */
if (RTStrICmp("Domain", keyName) == 0)
{
strDomain.assign(keyData, cbKeyData);
LogRel2(("HostDnsServiceWin: Domain=\"%s\"\n", strDomain.c_str()));
}
else if (RTStrICmp("DhcpDomain", keyName) == 0)
{
std::string strDhcpDomain(keyData, cbKeyData);
LogRel2(("HostDnsServiceWin: DhcpDomain=\"%s\"\n", strDhcpDomain.c_str()));
}
else if (RTStrICmp("SearchList", keyName) == 0)
{
strSearchList.assign(keyData, cbKeyData);
LogRel2(("HostDnsServiceWin: SearchList=\"%s\"\n", strSearchList.c_str()));
}
}
/* statically configured domain name */
if (!strDomain.empty())
{
info.domain = strDomain;
info.searchList.push_back(strDomain);
}
/* statically configured search list */
if (!strSearchList.empty())
{
vappend(info.searchList, strSearchList, ',');
}
/*
* When name servers are configured statically it seems that the
* value of Tcpip\Parameters\NameServer is NOT set, inly interface
* specific NameServer value is (which triggers notification for
* us to pick up the change). Fortunately, DnsApi seems to do the
* right thing there.
*/
DNS_STATUS status;
PIP4_ARRAY pIp4Array = NULL;
// NB: must be set on input it seems, despite docs' claim to the contrary.
DWORD cbBuffer = sizeof(&pIp4Array);
status = DnsQueryConfig(DnsConfigDnsServerList,
DNS_CONFIG_FLAG_ALLOC, NULL, NULL,
&pIp4Array, &cbBuffer);
if (status == NO_ERROR && pIp4Array != NULL)
{
for (DWORD i = 0; i < pIp4Array->AddrCount; ++i)
{
char szAddrStr[16] = "";
RTStrPrintf(szAddrStr, sizeof(szAddrStr), "%RTnaipv4", pIp4Array->AddrArray[i]);
LogRel2(("HostDnsServiceWin: server %d: %s\n", i+1, szAddrStr));
info.servers.push_back(szAddrStr);
}
LocalFree(pIp4Array);
}
/**
* DnsQueryConfig(DnsConfigSearchList, ...) is not implemented.
* Call GetAdaptersAddresses() that orders the returned list
* appropriately and collect IP_ADAPTER_ADDRESSES::DnsSuffix.
*/
do {
PIP_ADAPTER_ADDRESSES pAddrBuf = NULL;
ULONG cbAddrBuf = 8 * 1024;
bool fReallocated = false;
ULONG err;
pAddrBuf = (PIP_ADAPTER_ADDRESSES) malloc(cbAddrBuf);
if (pAddrBuf == NULL)
{
LogRel2(("HostDnsServiceWin: failed to allocate %zu bytes"
" of GetAdaptersAddresses buffer\n",
(size_t)cbAddrBuf));
break;
}
while (pAddrBuf != NULL)
{
ULONG cbAddrBufProvided = cbAddrBuf;
err = GetAdaptersAddresses(AF_UNSPEC,
GAA_FLAG_SKIP_ANYCAST
| GAA_FLAG_SKIP_MULTICAST,
NULL,
pAddrBuf, &cbAddrBuf);
if (err == NO_ERROR)
{
break;
}
else if (err == ERROR_BUFFER_OVERFLOW)
{
LogRel2(("HostDnsServiceWin: provided GetAdaptersAddresses with %zu"
" but asked again for %zu bytes\n",
(size_t)cbAddrBufProvided, (size_t)cbAddrBuf));
if (RT_UNLIKELY(fReallocated)) /* what? again?! */
{
LogRel2(("HostDnsServiceWin: ... not going to realloc again\n"));
free(pAddrBuf);
pAddrBuf = NULL;
break;
}
PIP_ADAPTER_ADDRESSES pNewBuf = (PIP_ADAPTER_ADDRESSES) realloc(pAddrBuf, cbAddrBuf);
if (pNewBuf == NULL)
{
LogRel2(("HostDnsServiceWin: failed to reallocate %zu bytes\n", (size_t)cbAddrBuf));
free(pAddrBuf);
pAddrBuf = NULL;
break;
}
/* try again */
pAddrBuf = pNewBuf; /* cbAddrBuf already updated */
fReallocated = true;
}
else
{
LogRel2(("HostDnsServiceWin: GetAdaptersAddresses error %d\n", err));
free(pAddrBuf);
pAddrBuf = NULL;
break;
}
}
if (pAddrBuf == NULL)
break;
for (PIP_ADAPTER_ADDRESSES pAdp = pAddrBuf; pAdp != NULL; pAdp = pAdp->Next)
{
LogRel2(("HostDnsServiceWin: %ls (status %u) ...\n",
pAdp->FriendlyName ? pAdp->FriendlyName : L"(null)",
pAdp->OperStatus));
if (pAdp->OperStatus != IfOperStatusUp)
continue;
if (pAdp->DnsSuffix == NULL || *pAdp->DnsSuffix == L'\0')
continue;
char *pszDnsSuffix = NULL;
rc = RTUtf16ToUtf8Ex(pAdp->DnsSuffix, RTSTR_MAX,
&pszDnsSuffix, 0, /* allocate */
NULL);
if (RT_FAILURE(rc))
{
LogRel2(("HostDnsServiceWin: failed to convert DNS suffix \"%ls\": %Rrc\n",
pAdp->DnsSuffix, rc));
continue;
}
AssertContinue(pszDnsSuffix != NULL);
AssertContinue(*pszDnsSuffix != '\0');
LogRel2(("HostDnsServiceWin: ... suffix = \"%s\"\n", pszDnsSuffix));
vappend(info.searchList, pszDnsSuffix);
RTStrFree(pszDnsSuffix);
}
free(pAddrBuf);
} while (0);
if (info.domain.empty() && !info.searchList.empty())
info.domain = info.searchList[0];
if (info.searchList.size() == 1)
info.searchList.clear();
HostDnsMonitor::setInfo(info);
return S_OK;
}
