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#include "lua-recursor.hh"
#include "config.h"
// to avoid including all of syncres.hh
int directResolve(const std::string& qname, const QType& qtype, int qclass, vector<DNSResourceRecord>& ret);
#if !defined(HAVE_LUA)
RecursorLua::RecursorLua(const std::string &fname)
: PowerDNSLua(fname)
{
// empty
}
bool RecursorLua::nxdomain(const ComboAddress& remote,const ComboAddress& local, const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return false;
}
bool RecursorLua::nodata(const ComboAddress& remote,const ComboAddress& local, const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return false;
}
bool RecursorLua::postresolve(const ComboAddress& remote,const ComboAddress& local, const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return false;
}
bool RecursorLua::preresolve(const ComboAddress& remote, const ComboAddress& local, const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return false;
}
#else
extern "C" {
#undef L
/* Include the Lua API header files. */
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
}
#include <stdlib.h>
#include <stdio.h>
#include <string>
#include <vector>
#include <stdexcept>
#include <boost/foreach.hpp>
#include "logger.hh"
#include "namespaces.hh"
RecursorLua::RecursorLua(const std::string &fname)
: PowerDNSLua(fname)
{
// empty
}
int followCNAMERecords(vector<DNSResourceRecord>& ret, const QType& qtype)
{
vector<DNSResourceRecord> resolved;
string target;
BOOST_FOREACH(DNSResourceRecord& rr, ret) {
if(rr.qtype.getCode() == QType::CNAME) {
target=rr.content;
break;
}
}
if(target.empty())
return 0;
if(target[target.size()-1]!='.')
target.append(1, '.');
int rcode=directResolve(target, qtype, 1, resolved); // 1 == class
BOOST_FOREACH(const DNSResourceRecord& rr, resolved)
{
ret.push_back(rr);
}
return rcode;
}
int getFakeAAAARecords(const std::string& qname, const std::string& prefix, vector<DNSResourceRecord>& ret)
{
int rcode=directResolve(qname, QType(QType::A), 1, ret);
ComboAddress prefixAddress(prefix);
BOOST_FOREACH(DNSResourceRecord& rr, ret)
{
if(rr.qtype.getCode() == QType::A && rr.d_place==DNSResourceRecord::ANSWER) {
ComboAddress ipv4(rr.content);
uint32_t tmp;
memcpy((void*)&tmp, &ipv4.sin4.sin_addr.s_addr, 4);
// tmp=htonl(tmp);
memcpy(((char*)&prefixAddress.sin6.sin6_addr.s6_addr)+12, &tmp, 4);
rr.content = prefixAddress.toString();
rr.qtype = QType(QType::AAAA);
}
}
return rcode;
}
int getFakePTRRecords(const std::string& qname, const std::string& prefix, vector<DNSResourceRecord>& ret)
{
/* qname has a reverse ordered IPv6 address, need to extract the underlying IPv4 address from it
and turn it into an IPv4 in-addr.arpa query */
ret.clear();
vector<string> parts;
stringtok(parts, qname, ".");
if(parts.size() < 8)
return -1;
string newquery;
for(int n = 0; n < 4; ++n) {
newquery +=
lexical_cast<string>(strtol(parts[n*2].c_str(), 0, 16) + 16*strtol(parts[n*2+1].c_str(), 0, 16));
newquery.append(1,'.');
}
newquery += "in-addr.arpa.";
int rcode = directResolve(newquery, QType(QType::PTR), 1, ret);
BOOST_FOREACH(DNSResourceRecord& rr, ret)
{
if(rr.qtype.getCode() == QType::PTR && rr.d_place==DNSResourceRecord::ANSWER) {
rr.qname = qname;
}
}
return rcode;
}
bool RecursorLua::nxdomain(const ComboAddress& remote, const ComboAddress& local,const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return passthrough("nxdomain", remote, local, query, qtype, ret, res, variable);
}
bool RecursorLua::preresolve(const ComboAddress& remote, const ComboAddress& local,const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return passthrough("preresolve", remote, local, query, qtype, ret, res, variable);
}
bool RecursorLua::nodata(const ComboAddress& remote, const ComboAddress& local,const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return passthrough("nodata", remote, local, query, qtype, ret, res, variable);
}
bool RecursorLua::postresolve(const ComboAddress& remote, const ComboAddress& local,const string& query, const QType& qtype, vector<DNSResourceRecord>& ret, int& res, bool* variable)
{
return passthrough("postresolve", remote, local, query, qtype, ret, res, variable);
}
bool RecursorLua::passthrough(const string& func, const ComboAddress& remote, const ComboAddress& local, const string& query, const QType& qtype, vector<DNSResourceRecord>& ret,
int& res, bool* variable)
{
d_variable = false;
lua_getglobal(d_lua, func.c_str());
if(!lua_isfunction(d_lua, -1)) {
// cerr<<"No such function '"<<func<<"'\n";
lua_pop(d_lua, 1);
return false;
}
d_local = local;
/* the first argument */
lua_pushstring(d_lua, remote.toString().c_str() );
lua_pushstring(d_lua, query.c_str() );
lua_pushnumber(d_lua, qtype.getCode() );
int extraParameter = 0;
if(!strcmp(func.c_str(),"nodata")) {
pushResourceRecordsTable(d_lua, ret);
extraParameter++;
}
else if(!strcmp(func.c_str(),"postresolve")) {
pushResourceRecordsTable(d_lua, ret);
lua_pushnumber(d_lua, res);
extraParameter+=2;
}
if(lua_pcall(d_lua, 3 + extraParameter, 3, 0)) { // NOTE! Means we always get 3 stack entries back!
string error=string("lua error in '"+func+"' while processing query for '"+query+"|"+qtype.getName()+": ")+lua_tostring(d_lua, -1);
lua_pop(d_lua, 1);
throw runtime_error(error);
return false;
}
*variable |= d_variable;
if(!lua_isnumber(d_lua, 1)) {
string tocall = lua_tostring(d_lua,1);
lua_remove(d_lua, 1); // the name
ret.clear();
if(tocall == "getFakeAAAARecords") {
string luaprefix = lua_tostring(d_lua, 2);
string luaqname = lua_tostring(d_lua,1);
lua_pop(d_lua, 2);
res = getFakeAAAARecords(luaqname, luaprefix, ret);
}
else if(tocall == "getFakePTRRecords") {
string luaprefix = lua_tostring(d_lua, 2);
string luaqname = lua_tostring(d_lua,1);
lua_pop(d_lua, 2);
res = getFakePTRRecords(luaqname, luaprefix, ret);
}
else if(tocall == "followCNAMERecords") {
popResourceRecordsTable(d_lua, query, ret);
lua_pop(d_lua, 2);
res = followCNAMERecords(ret, qtype);
}
return true;
// returned a followup
}
int newres = (int)lua_tonumber(d_lua, 1); // new rcode
if(newres == -1) {
// cerr << "handler did not handle"<<endl;
lua_pop(d_lua, 3);
return false;
}
res=newres;
ret.clear();
/* 1 2 3 4 */
/* stack: boolean table key row */
popResourceRecordsTable(d_lua, query, ret); // doesn't actually pop the table itself!
lua_pop(d_lua, 3);
return true;
}
#endif
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