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/*
PowerDNS Versatile Database Driven Nameserver
Copyright (C) 2002-2012 PowerDNS.COM BV
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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "packetcache.hh"
#include "utility.hh"
#include "base32.hh"
#include <string>
#include <sys/types.h>
#include <boost/algorithm/string.hpp>
#include <boost/foreach.hpp>
#include "dnssecinfra.hh"
#include "dnsseckeeper.hh"
#include "dns.hh"
#include "dnsbackend.hh"
#include "ueberbackend.hh"
#include "dnspacket.hh"
#include "nameserver.hh"
#include "distributor.hh"
#include "logger.hh"
#include "arguments.hh"
#include "packethandler.hh"
#include "statbag.hh"
#include "resolver.hh"
#include "communicator.hh"
#include "dnsproxy.hh"
#include "version.hh"
#include "common_startup.hh"
#if 0
#undef DLOG
#define DLOG(x) x
#endif
AtomicCounter PacketHandler::s_count;
extern string s_programname;
PacketHandler::PacketHandler():B(s_programname)
{
++s_count;
d_doFancyRecords = (::arg()["fancy-records"]!="no");
d_doRecursion= ::arg().mustDo("recursor");
d_logDNSDetails= ::arg().mustDo("log-dns-details");
d_doIPv6AdditionalProcessing = ::arg().mustDo("do-ipv6-additional-processing");
string fname= ::arg()["lua-prequery-script"];
if(fname.empty())
{
d_pdl = NULL;
}
else
{
d_pdl = new AuthLua(fname);
}
}
DNSBackend *PacketHandler::getBackend()
{
return &B;
}
PacketHandler::~PacketHandler()
{
--s_count;
DLOG(L<<Logger::Error<<"PacketHandler destructor called - "<<s_count<<" left"<<endl);
}
void PacketHandler::addRootReferral(DNSPacket* r)
{
// nobody reads what we output, but it appears to be the magic that shuts some nameservers up
static const char*ips[]={"198.41.0.4", "192.228.79.201", "192.33.4.12", "199.7.91.13", "192.203.230.10", "192.5.5.241", "192.112.36.4", "128.63.2.53",
"192.36.148.17","192.58.128.30", "193.0.14.129", "199.7.83.42", "202.12.27.33"};
static char templ[40];
strncpy(templ,"a.root-servers.net", sizeof(templ) - 1);
// add . NS records
DNSResourceRecord rr;
rr.qtype=QType::NS;
rr.ttl=518400;
rr.d_place=DNSResourceRecord::AUTHORITY;
for(char c='a';c<='m';++c) {
*templ=c;
rr.content=templ;
r->addRecord(rr);
}
if(pdns_iequals(::arg()["send-root-referral"], "lean"))
return;
// add the additional stuff
rr.ttl=3600000;
rr.qtype=QType::A;
rr.d_place=DNSResourceRecord::ADDITIONAL;
for(char c='a';c<='m';++c) {
*templ=c;
rr.qname=templ;
rr.content=ips[c-'a'];
r->addRecord(rr);
}
}
int PacketHandler::findMboxFW(DNSPacket *p, DNSPacket *r, string &target)
{
DNSResourceRecord rr;
bool wedoforward=false;
SOAData sd;
int zoneId;
if(!getAuth(p, &sd, target, &zoneId))
return false;
B.lookup(QType(QType::MBOXFW),string("%@")+target,p, zoneId);
while(B.get(rr))
wedoforward=true;
if(wedoforward) {
r->clearRecords();
rr.content=::arg()["smtpredirector"];
rr.priority=25;
rr.ttl=7200;
rr.qtype=QType::MX;
rr.qname=target;
r->addRecord(rr);
}
return wedoforward;
}
int PacketHandler::findUrl(DNSPacket *p, DNSPacket *r, string &target)
{
DNSResourceRecord rr;
bool found=false;
B.lookup(QType(QType::URL),target,p); // search for a URL before we search for an A
while(B.get(rr)) {
if(!found)
r->clearRecords();
found=true;
DLOG(L << "Found a URL!" << endl);
rr.content=::arg()["urlredirector"];
rr.qtype=QType::A;
rr.qname=target;
r->addRecord(rr);
}
if(found)
return 1;
// now try CURL
B.lookup(QType(QType::CURL),target,p); // search for a URL before we search for an A
while(B.get(rr)) {
if(!found)
r->clearRecords();
found=true;
DLOG(L << "Found a CURL!" << endl);
rr.content=::arg()["urlredirector"];
rr.qtype=1; // A
rr.qname=target;
rr.ttl=300;
r->addRecord(rr);
}
if(found)
return found;
return 0;
}
/** Returns 0 if nothing was found, -1 if an error occured or 1 if the search
was satisfied */
int PacketHandler::doFancyRecords(DNSPacket *p, DNSPacket *r, string &target)
{
DNSResourceRecord rr;
if(p->qtype.getCode()==QType::MX) // check if this domain has smtp service from us
return findMboxFW(p,r,target);
if(p->qtype.getCode()==QType::A) // search for a URL record for an A
return findUrl(p,r,target);
return 0;
}
/** This adds DNSKEY records. Returns true if one was added */
bool PacketHandler::addDNSKEY(DNSPacket *p, DNSPacket *r, const SOAData& sd)
{
DNSResourceRecord rr;
bool haveOne=false;
DNSSECPrivateKey dpk;
DNSSECKeeper::keyset_t keyset = d_dk.getKeys(p->qdomain);
BOOST_FOREACH(DNSSECKeeper::keyset_t::value_type value, keyset) {
rr.qtype=QType::DNSKEY;
rr.ttl=sd.default_ttl;
rr.qname=p->qdomain;
rr.content=value.first.getDNSKEY().getZoneRepresentation();
rr.auth=true;
r->addRecord(rr);
haveOne=true;
}
if(::arg().mustDo("direct-dnskey")) {
B.lookup(QType(QType::DNSKEY), p->qdomain, p, sd.domain_id);
while(B.get(rr)) {
rr.ttl=sd.default_ttl;
r->addRecord(rr);
haveOne=true;
}
}
return haveOne;
}
/** This adds NSEC3PARAM records. Returns true if one was added */
bool PacketHandler::addNSEC3PARAM(DNSPacket *p, DNSPacket *r, const SOAData& sd)
{
DNSResourceRecord rr;
NSEC3PARAMRecordContent ns3prc;
if(d_dk.getNSEC3PARAM(p->qdomain, &ns3prc)) {
rr.qtype=QType::NSEC3PARAM;
rr.ttl=sd.default_ttl;
rr.qname=p->qdomain;
ns3prc.d_flags = 0; // the NSEC3PARAM 'flag' is defined to always be zero in RFC5155.
rr.content=ns3prc.getZoneRepresentation();
rr.auth = true;
r->addRecord(rr);
return true;
}
return false;
}
/** This catches version requests. Returns 1 if it was handled, 0 if it wasn't */
int PacketHandler::doVersionRequest(DNSPacket *p, DNSPacket *r, string &target)
{
DNSResourceRecord rr;
if(p->qclass == QClass::CHAOS && p->qtype.getCode()==QType::TXT && target=="version.bind") {// TXT
// modes: anonymous, powerdns only, full, spoofed
const static string mode=::arg()["version-string"];
if(mode.empty() || mode=="full")
rr.content=fullVersionString();
else if(mode=="anonymous") {
r->setRcode(RCode::ServFail);
return 1;
}
else if(mode=="powerdns")
rr.content="Served by PowerDNS - http://www.powerdns.com";
else
rr.content=mode;
rr.ttl=5;
rr.qname=target;
rr.qtype=QType::TXT;
rr.qclass=QClass::CHAOS;
r->addRecord(rr);
return 1;
}
return 0;
}
/** Determines if we are authoritative for a zone, and at what level */
bool PacketHandler::getAuth(DNSPacket *p, SOAData *sd, const string &target, int *zoneId)
{
bool found=false;
string subdomain(target);
do {
if( B.getSOA( subdomain, *sd, p ) ) {
sd->qname = subdomain;
if(zoneId)
*zoneId = sd->domain_id;
if(p->qtype.getCode() == QType::DS && pdns_iequals(subdomain, target)) {
// Found authoritative zone but look for parent zone with 'DS' record.
found=true;
} else
return true;
}
}
while( chopOff( subdomain ) ); // 'www.powerdns.org' -> 'powerdns.org' -> 'org' -> ''
return found;
}
vector<DNSResourceRecord> PacketHandler::getBestReferralNS(DNSPacket *p, SOAData& sd, const string &target)
{
vector<DNSResourceRecord> ret;
DNSResourceRecord rr;
string subdomain(target);
do {
if(subdomain == sd.qname) // stop at SOA
break;
B.lookup(QType(QType::NS), subdomain, p, sd.domain_id);
while(B.get(rr)) {
ret.push_back(rr); // this used to exclude auth NS records for some reason
}
if(!ret.empty())
return ret;
} while( chopOff( subdomain ) ); // 'www.powerdns.org' -> 'powerdns.org' -> 'org' -> ''
return ret;
}
// Return best matching wildcard or next closer name
bool PacketHandler::getBestWildcard(DNSPacket *p, SOAData& sd, const string &target, string &wildcard, vector<DNSResourceRecord>* ret)
{
ret->clear();
DNSResourceRecord rr;
string subdomain(target);
bool haveSomething=false;
wildcard=subdomain;
while( chopOff( subdomain ) && !haveSomething ) {
if (subdomain.empty()) {
B.lookup(QType(QType::ANY), "*", p, sd.domain_id);
} else {
B.lookup(QType(QType::ANY), "*."+subdomain, p, sd.domain_id);
}
while(B.get(rr)) {
if(rr.qtype == p->qtype || rr.qtype.getCode() == QType::CNAME || (p->qtype.getCode() == QType::ANY && rr.qtype.getCode() != QType::RRSIG))
ret->push_back(rr);
wildcard="*."+subdomain;
haveSomething=true;
}
if ( subdomain == sd.qname || haveSomething ) // stop at SOA or result
break;
B.lookup(QType(QType::ANY), subdomain, p, sd.domain_id);
if (B.get(rr)) {
DLOG(L<<"No wildcard match, ancestor exists"<<endl);
while (B.get(rr)) ;
break;
}
wildcard=subdomain;
}
return haveSomething;
}
/** dangling is declared true if we were unable to resolve everything */
int PacketHandler::doAdditionalProcessingAndDropAA(DNSPacket *p, DNSPacket *r, const SOAData& soadata)
{
DNSResourceRecord rr;
SOAData sd;
sd.db=0;
if(p->qtype.getCode()!=QType::AXFR) { // this packet needs additional processing
vector<DNSResourceRecord *> arrs=r->getAPRecords();
if(arrs.empty())
return 1;
DLOG(L<<Logger::Warning<<"This packet needs additional processing!"<<endl);
vector<DNSResourceRecord> crrs;
for(vector<DNSResourceRecord *>::const_iterator i=arrs.begin(); i!=arrs.end(); ++i)
crrs.push_back(**i);
// we now have a copy, push_back on packet might reallocate!
for(vector<DNSResourceRecord>::const_iterator i=crrs.begin(); i!=crrs.end(); ++i) {
if(r->d.aa && !i->qname.empty() && i->qtype.getCode()==QType::NS && !B.getSOA(i->qname,sd,p)) { // drop AA in case of non-SOA-level NS answer, except for root referral
r->setA(false);
// i->d_place=DNSResourceRecord::AUTHORITY; // XXX FIXME
}
string content = stripDot(i->content);
QType qtypes[2];
qtypes[0]="A"; qtypes[1]="AAAA";
for(int n=0 ; n < d_doIPv6AdditionalProcessing + 1; ++n) {
if (i->qtype.getCode()==QType::SRV) {
vector<string>parts;
stringtok(parts, content);
if (parts.size() >= 3) {
B.lookup(qtypes[n],parts[2],p);
}
else
continue;
}
else {
B.lookup(qtypes[n], content, p);
}
while(B.get(rr)) {
if(rr.domain_id!=i->domain_id && ::arg()["out-of-zone-additional-processing"]=="no") {
DLOG(L<<Logger::Warning<<"Not including out-of-zone additional processing of "<<i->qname<<" ("<<rr.qname<<")"<<endl);
continue; // not adding out-of-zone additional data
}
if(rr.auth && !endsOn(rr.qname, soadata.qname)) // don't sign out of zone data using the main key
rr.auth=false;
rr.d_place=DNSResourceRecord::ADDITIONAL;
r->addRecord(rr);
}
}
}
}
return 1;
}
void PacketHandler::emitNSEC(const std::string& begin, const std::string& end, const std::string& toNSEC, const SOAData& sd, DNSPacket *r, int mode)
{
// <<"We should emit '"<<begin<<"' - ('"<<toNSEC<<"') - '"<<end<<"'"<<endl;
NSECRecordContent nrc;
nrc.d_set.insert(QType::RRSIG);
nrc.d_set.insert(QType::NSEC);
if(pdns_iequals(sd.qname, begin))
nrc.d_set.insert(QType::DNSKEY);
DNSResourceRecord rr;
B.lookup(QType(QType::ANY), begin, NULL, sd.domain_id);
while(B.get(rr)) {
if(rr.qtype.getCode() == QType::NS || rr.auth)
nrc.d_set.insert(rr.qtype.getCode());
}
nrc.d_next=end;
rr.qname=begin;
rr.ttl = sd.default_ttl;
rr.qtype=QType::NSEC;
rr.content=nrc.getZoneRepresentation();
rr.d_place = (mode == 5 ) ? DNSResourceRecord::ANSWER: DNSResourceRecord::AUTHORITY;
rr.auth = true;
r->addRecord(rr);
}
void emitNSEC3(DNSBackend& B, const NSEC3PARAMRecordContent& ns3prc, const SOAData& sd, const std::string& unhashed, const std::string& begin, const std::string& end, const std::string& toNSEC3, DNSPacket *r, int mode)
{
// cerr<<"We should emit NSEC3 '"<<toLower(toBase32Hex(begin))<<"' - ('"<<toNSEC3<<"') - '"<<toLower(toBase32Hex(end))<<"' (unhashed: '"<<unhashed<<"')"<<endl;
NSEC3RecordContent n3rc;
n3rc.d_salt=ns3prc.d_salt;
n3rc.d_flags = ns3prc.d_flags;
n3rc.d_iterations = ns3prc.d_iterations;
n3rc.d_algorithm = 1; // SHA1, fixed in PowerDNS for now
DNSResourceRecord rr;
if(!unhashed.empty()) {
B.lookup(QType(QType::ANY), unhashed, NULL, sd.domain_id);
while(B.get(rr)) {
if(rr.qtype.getCode() && (rr.qtype.getCode() == QType::NS || rr.auth)) // skip empty non-terminals
n3rc.d_set.insert(rr.qtype.getCode());
}
if(toLower(unhashed) == toLower(sd.qname)) {
n3rc.d_set.insert(QType::NSEC3PARAM);
n3rc.d_set.insert(QType::DNSKEY);
}
}
if (n3rc.d_set.size() && !(n3rc.d_set.size() == 1 && n3rc.d_set.count(QType::NS)))
n3rc.d_set.insert(QType::RRSIG);
n3rc.d_nexthash=end;
rr.qname=dotConcat(toLower(toBase32Hex(begin)), sd.qname);
rr.ttl = sd.default_ttl;
rr.qtype=QType::NSEC3;
rr.content=n3rc.getZoneRepresentation();
rr.d_place = (mode == 5 ) ? DNSResourceRecord::ANSWER: DNSResourceRecord::AUTHORITY;
rr.auth = true;
r->addRecord(rr);
}
void PacketHandler::emitNSEC3(const NSEC3PARAMRecordContent& ns3prc, const SOAData& sd, const std::string& unhashed, const std::string& begin, const std::string& end, const std::string& toNSEC3, DNSPacket *r, int mode)
{
::emitNSEC3(B, ns3prc, sd, unhashed, begin, end, toNSEC3, r, mode);
}
/*
mode 0 = No Data Responses, QTYPE is not DS
mode 1 = No Data Responses, QTYPE is DS
mode 2 = Wildcard No Data Responses
mode 3 = Wildcard Answer Responses
mode 4 = Name Error Responses
mode 5 = Direct NSEC request
*/
void PacketHandler::addNSECX(DNSPacket *p, DNSPacket *r, const string& target, const string& wildcard, const string& auth, int mode)
{
if(!p->d_dnssecOk && mode != 5)
return;
NSEC3PARAMRecordContent ns3rc;
// cerr<<"Doing NSEC3PARAM lookup for '"<<auth<<"', "<<p->qdomain<<"|"<<p->qtype.getName()<<": ";
bool narrow;
if(d_dk.getNSEC3PARAM(auth, &ns3rc, &narrow)) {
// cerr<<"Present, narrow="<<narrow<<endl;
if (mode != 5) // no direct NSEC3 please
addNSEC3(p, r, target, wildcard, auth, ns3rc, narrow, mode);
}
else {
// cerr<<"Not present"<<endl;
addNSEC(p, r, target, wildcard, auth, mode);
}
}
static void incrementHash(std::string& raw) // I wonder if this is correct, cmouse? ;-)
{
if(raw.empty())
return;
for(string::size_type pos=raw.size(); pos; ) {
--pos;
unsigned char c = (unsigned char)raw[pos];
++c;
raw[pos] = (char) c;
if(c)
break;
}
}
static void decrementHash(std::string& raw) // I wonder if this is correct, cmouse? ;-)
{
if(raw.empty())
return;
for(string::size_type pos=raw.size(); pos; ) {
--pos;
unsigned char c = (unsigned char)raw[pos];
--c;
raw[pos] = (char) c;
if(c != 0xff)
break;
}
}
bool getNSEC3Hashes(bool narrow, DNSBackend* db, int id, const std::string& hashed, bool decrement, string& unhashed, string& before, string& after, int mode)
{
bool ret;
if(narrow) { // nsec3-narrow
ret=true;
before=hashed;
if(decrement) {
decrementHash(before);
unhashed.clear();
}
after=hashed;
incrementHash(after);
}
else {
if (decrement || mode ==1)
before.clear();
else
before=' ';
ret=db->getBeforeAndAfterNamesAbsolute(id, toLower(toBase32Hex(hashed)), unhashed, before, after);
before=fromBase32Hex(before);
after=fromBase32Hex(after);
}
// cerr<<"rgetNSEC3Hashes: "<<hashed<<", "<<unhashed<<", "<<before<<", "<<after<<endl;
return ret;
}
void PacketHandler::addNSEC3(DNSPacket *p, DNSPacket *r, const string& target, const string& wildcard, const string& auth, const NSEC3PARAMRecordContent& ns3rc, bool narrow, int mode)
{
DLOG(L<<"mode="<<mode<<" target="<<target<<" wildcard="<<wildcard<<" auth="<<auth<<endl);
SOAData sd;
sd.db = (DNSBackend*)-1;
if(!B.getSOA(auth, sd)) {
// cerr<<"Could not get SOA for domain in NSEC3\n";
return;
}
bool doNextcloser = false;
string unhashed, hashed, before, after;
string closest;
if (mode == 2 || mode == 3 || mode == 4) {
closest=wildcard;
chopOff(closest);
} else
closest=target;
// add matching NSEC3 RR
// we used to skip this one for mode 3, but old BIND needs it
// see https://github.com/PowerDNS/pdns/issues/814
if (mode != 3 || g_addSuperfluousNSEC3) {
unhashed=(mode == 0 || mode == 1 || mode == 5) ? target : closest;
hashed=hashQNameWithSalt(ns3rc.d_iterations, ns3rc.d_salt, unhashed);
DLOG(L<<"1 hash: "<<toBase32Hex(hashed)<<" "<<unhashed<<endl);
getNSEC3Hashes(narrow, sd.db, sd.domain_id, hashed, false, unhashed, before, after, mode);
if (mode == 1 && (hashed != before)) {
DLOG(L<<"No matching NSEC3 for DS, do closest (provable) encloser"<<endl);
DNSResourceRecord rr;
while( chopOff( closest ) && (closest != sd.qname)) { // stop at SOA
B.lookup(QType(QType::ANY), closest, p, sd.domain_id);
if (B.get(rr)) {
while(B.get(rr));
break;
}
}
doNextcloser = true;
unhashed=closest;
hashed=hashQNameWithSalt(ns3rc.d_iterations, ns3rc.d_salt, unhashed);
DLOG(L<<"1 hash: "<<toBase32Hex(hashed)<<" "<<unhashed<<endl);
getNSEC3Hashes(narrow, sd.db, sd.domain_id, hashed, false, unhashed, before, after);
}
DLOG(L<<"Done calling for matching, hashed: '"<<toBase32Hex(hashed)<<"' before='"<<toBase32Hex(before)<<"', after='"<<toBase32Hex(after)<<"'"<<endl);
emitNSEC3(ns3rc, sd, unhashed, before, after, target, r, mode);
}
// add covering NSEC3 RR
if ((mode >= 2 && mode <= 4) || doNextcloser) {
string next(target);
do {
unhashed=next;
}
while( chopOff( next ) && !pdns_iequals(next, closest));
hashed=hashQNameWithSalt(ns3rc.d_iterations, ns3rc.d_salt, unhashed);
DLOG(L<<"2 hash: "<<toBase32Hex(hashed)<<" "<<unhashed<<endl);
getNSEC3Hashes(narrow, sd.db,sd.domain_id, hashed, true, unhashed, before, after);
DLOG(L<<"Done calling for covering, hashed: '"<<toBase32Hex(hashed)<<"' before='"<<toBase32Hex(before)<<"', after='"<<toBase32Hex(after)<<"'"<<endl);
emitNSEC3( ns3rc, sd, unhashed, before, after, target, r, mode);
}
// wildcard denial
if (mode == 2 || mode == 4) {
unhashed=dotConcat("*", closest);
hashed=hashQNameWithSalt(ns3rc.d_iterations, ns3rc.d_salt, unhashed);
DLOG(L<<"3 hash: "<<toBase32Hex(hashed)<<" "<<unhashed<<endl);
getNSEC3Hashes(narrow, sd.db, sd.domain_id, hashed, (mode != 2), unhashed, before, after);
DLOG(L<<"Done calling for '*', hashed: '"<<toBase32Hex(hashed)<<"' before='"<<toBase32Hex(before)<<"', after='"<<toBase32Hex(after)<<"'"<<endl);
emitNSEC3( ns3rc, sd, unhashed, before, after, target, r, mode);
}
}
void PacketHandler::addNSEC(DNSPacket *p, DNSPacket *r, const string& target, const string& wildcard, const string& auth, int mode)
{
DLOG(L<<"Should add NSEC covering '"<<target<<"' from zone '"<<auth<<"', mode = "<<mode<<endl);
SOAData sd;
if(auth.empty()) {
getAuth(p, &sd, target, 0);
}
sd.db=(DNSBackend *)-1; // force uncached answer
if(!B.getSOA(auth, sd)) {
DLOG(L<<"Could not get SOA for domain"<<endl);
return;
}
string before,after;
sd.db->getBeforeAndAfterNames(sd.domain_id, auth, target, before, after);
emitNSEC(before, after, target, sd, r, mode);
if (mode == 2 || mode == 4) {
// wildcard NO-DATA or wildcard denial
before.clear();
string closest(wildcard);
if (mode == 4) {
(void) chopOff(closest);
closest=dotConcat("*", closest);
}
sd.db->getBeforeAndAfterNames(sd.domain_id, auth, closest, before, after);
emitNSEC(before, after, target, sd, r, mode);
}
return;
}
/* Semantics:
- only one backend owns the SOA of a zone
- only one AXFR per zone at a time - double startTransaction should fail
- backends need to implement transaction semantics
How BindBackend would implement this:
startTransaction makes a file
feedRecord sends everything to that file
commitTransaction moves that file atomically over the regular file, and triggers a reload
rollbackTransaction removes the file
How PostgreSQLBackend would implement this:
startTransaction starts a sql transaction, which also deletes all records
feedRecord is an insert statement
commitTransaction commits the transaction
rollbackTransaction aborts it
How MySQLBackend would implement this:
(good question!)
*/
int PacketHandler::trySuperMaster(DNSPacket *p)
{
if(p->d_tcp)
{
// do it right now if the client is TCP
// rarely happens
return trySuperMasterSynchronous(p);
}
else
{
// queue it if the client is on UDP
Communicator.addTrySuperMasterRequest(p);
return 0;
}
}
int PacketHandler::trySuperMasterSynchronous(DNSPacket *p)
{
Resolver::res_t nsset;
try {
Resolver resolver;
uint32_t theirserial;
resolver.getSoaSerial(p->getRemote(),p->qdomain, &theirserial);
resolver.resolve(p->getRemote(), p->qdomain.c_str(), QType::NS, &nsset);
}
catch(ResolverException &re) {
L<<Logger::Error<<"Error resolving SOA or NS for "<<p->qdomain<<" at: "<< p->getRemote() <<": "<<re.reason<<endl;
return RCode::ServFail;
}
string account;
DNSBackend *db;
if(!B.superMasterBackend(p->getRemote(), p->qdomain, nsset, &account, &db)) {
L<<Logger::Error<<"Unable to find backend willing to host "<<p->qdomain<<" for potential supermaster "<<p->getRemote()<<". "<<nsset.size()<<" remote nameservers: "<<endl;
BOOST_FOREACH(class DNSResourceRecord& rr, nsset) {
L<<Logger::Error<<rr.content<<endl;
}
return RCode::Refused;
}
try {
db->createSlaveDomain(p->getRemote(),p->qdomain,account);
}
catch(AhuException& ae) {
L<<Logger::Error<<"Database error trying to create "<<p->qdomain<<" for potential supermaster "<<p->getRemote()<<": "<<ae.reason<<endl;
return RCode::ServFail;
}
Communicator.addSuckRequest(p->qdomain, p->getRemote());
L<<Logger::Warning<<"Created new slave zone '"<<p->qdomain<<"' from supermaster "<<p->getRemote()<<", queued axfr"<<endl;
return RCode::NoError;
}
int PacketHandler::processNotify(DNSPacket *p)
{
/* now what?
was this notification from an approved address?
We determine our internal SOA id (via UeberBackend)
We determine the SOA at our (known) master
if master is higher -> do stuff
*/
if(!::arg().mustDo("slave")) {
L<<Logger::Error<<"Received NOTIFY for "<<p->qdomain<<" from "<<p->getRemote()<<" but slave support is disabled in the configuration"<<endl;
return RCode::NotImp;
}
DNSBackend *db=0;
DomainInfo di;
di.serial = 0;
if(!B.getDomainInfo(p->qdomain, di) || !(db=di.backend)) {
L<<Logger::Error<<"Received NOTIFY for "<<p->qdomain<<" from "<<p->getRemote()<<" for which we are not authoritative"<<endl;
return trySuperMaster(p);
}
if(::arg().contains("trusted-notification-proxy", p->getRemote())) {
L<<Logger::Error<<"Received NOTIFY for "<<p->qdomain<<" from trusted-notification-proxy "<< p->getRemote()<<endl;
if(di.masters.empty()) {
L<<Logger::Error<<"However, "<<p->qdomain<<" does not have any masters defined"<<endl;
return RCode::Refused;
}
}
else if(!db->isMaster(p->qdomain, p->getRemote())) {
L<<Logger::Error<<"Received NOTIFY for "<<p->qdomain<<" from "<<p->getRemote()<<" which is not a master"<<endl;
return RCode::Refused;
}
// ok, we've done our checks
di.backend = 0;
Communicator.addSlaveCheckRequest(di, p->d_remote);
return 0;
}
bool validDNSName(const string &name)
{
string::size_type pos, length=name.length();
char c;
for(pos=0; pos < length; ++pos) {
c=name[pos];
if(!((c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c =='-' || c == '_' || c=='*' || c=='.' || c=='/' || c=='@' || c==' ' || c=='\\' || c==':'))
return false;
}
return true;
}
DNSPacket *PacketHandler::question(DNSPacket *p)
{
DNSPacket *ret;
if(d_pdl)
{
ret=d_pdl->prequery(p);
if(ret)
return ret;
}
bool shouldRecurse=false;
ret=questionOrRecurse(p, &shouldRecurse);
if(shouldRecurse) {
DP->sendPacket(p);
}
return ret;
}
void PacketHandler::synthesiseRRSIGs(DNSPacket* p, DNSPacket* r)
{
DLOG(L<<"Need to synthesise the RRSIGs if someone asked for them explicitly"<<endl);
typedef map<uint16_t, vector<shared_ptr<DNSRecordContent> > > records_t;
typedef map<uint16_t, uint32_t> ttls_t;
records_t records;
ttls_t ttls;
NSECRecordContent nrc;
NSEC3RecordContent n3rc;
nrc.d_set.insert(QType::RRSIG);
DNSResourceRecord rr;
SOAData sd;
sd.db=(DNSBackend *)-1; // force uncached answer
getAuth(p, &sd, p->qdomain, 0);
bool narrow;
NSEC3PARAMRecordContent ns3pr;
bool doNSEC3= d_dk.getNSEC3PARAM(sd.qname, &ns3pr, &narrow);
B.lookup(QType(QType::ANY), p->qdomain, p);
bool haveone=false;
while(B.get(rr)) {
haveone=true;
if(!((rr.auth && rr.qtype.getCode()) || (!(doNSEC3 && ns3pr.d_flags) && rr.qtype.getCode() == QType::NS)))
continue;
// make sure all fields are present in the SOA content
if(rr.qtype.getCode() == QType::SOA) {
rr.content = serializeSOAData(sd);
}
// this deals with the 'prio' mismatch!
if(rr.qtype.getCode()==QType::MX || rr.qtype.getCode() == QType::SRV) {
rr.content = lexical_cast<string>(rr.priority) + " " + rr.content;
}
// fix direct DNSKEY ttl
if(::arg().mustDo("direct-dnskey") && rr.qtype.getCode() == QType::DNSKEY) {
rr.ttl = sd.default_ttl;
}
if(!rr.content.empty() && rr.qtype.getCode()==QType::TXT && rr.content[0]!='"') {
rr.content="\""+rr.content+"\"";
}
if(rr.content.empty()) // empty contents confuse the MOADNS setup
rr.content=".";
shared_ptr<DNSRecordContent> drc(DNSRecordContent::mastermake(rr.qtype.getCode(), 1, rr.content));
records[rr.qtype.getCode()].push_back(drc);
ttls[rr.qtype.getCode()]=rr.ttl;
nrc.d_set.insert(rr.qtype.getCode());
}
if(records.empty()) {
if (haveone)
makeNOError(p, r, p->qdomain, "", sd, 0);
return;
}
if(pdns_iequals(p->qdomain, sd.qname)) { // Add DNSKEYs at apex
DNSSECPrivateKey dpk;
DNSSECKeeper::keyset_t keyset = d_dk.getKeys(p->qdomain);
BOOST_FOREACH(DNSSECKeeper::keyset_t::value_type value, keyset) {
records[QType::DNSKEY].push_back(shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::DNSKEY, 1, value.first.getDNSKEY().getZoneRepresentation())));
ttls[QType::DNSKEY]=sd.default_ttl;
nrc.d_set.insert(QType::DNSKEY);
}
}
string before,after;
string unhashed(p->qdomain);
if(doNSEC3) {
// now get the NSEC3 and NSEC3PARAM
string hashed=hashQNameWithSalt(ns3pr.d_iterations, ns3pr.d_salt, unhashed);
getNSEC3Hashes(narrow, sd.db, sd.domain_id, hashed, false, unhashed, before, after);
unhashed=dotConcat(toLower(toBase32Hex(before)), sd.qname);
n3rc.d_set=nrc.d_set; // Copy d_set from NSEC
n3rc.d_algorithm=ns3pr.d_algorithm;
n3rc.d_flags=ns3pr.d_flags;
n3rc.d_iterations=ns3pr.d_iterations;
n3rc.d_salt=ns3pr.d_salt;
n3rc.d_nexthash=after;
if(pdns_iequals(p->qdomain, sd.qname)) {
ns3pr.d_flags = 0; // the NSEC3PARAM 'flag' is defined to always be zero in RFC5155.
records[QType::NSEC3PARAM].push_back(shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::NSEC3PARAM, 1, ns3pr.getZoneRepresentation())));
ttls[QType::NSEC3PARAM]=sd.default_ttl;
n3rc.d_set.insert(QType::NSEC3PARAM);
}
// ok, the NSEC3PARAM is in..
}
else {
// now get the NSEC too (since we must sign it!)
sd.db->getBeforeAndAfterNames(sd.domain_id, sd.qname, p->qdomain, before, after);
nrc.d_set.insert(QType::NSEC);
nrc.d_next=after;
records[QType::NSEC].push_back(shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::NSEC, 1, nrc.getZoneRepresentation())));
ttls[QType::NSEC]=sd.default_ttl;
// ok, the NSEC is in..
}
DLOG(L<<"Have "<<records.size()<<" rrsets to sign"<<endl);
rr.auth = 0; // please don't sign this!
rr.d_place = DNSResourceRecord::ANSWER;
rr.qtype = QType::RRSIG;
vector<DNSResourceRecord> rrsigs;
BOOST_FOREACH(records_t::value_type& iter, records) {
rr.qname=(doNSEC3 && iter.first == QType::NSEC3) ? unhashed : p->qdomain;
rr.ttl=ttls[iter.first];
addSignature(d_dk, B, sd.qname, rr.qname, rr.qname, iter.first, rr.ttl, DNSPacketWriter::ANSWER, iter.second, rrsigs, rr.ttl);
}
BOOST_FOREACH(DNSResourceRecord& rr, rrsigs)
r->addRecord(rr);
}
void PacketHandler::makeNXDomain(DNSPacket* p, DNSPacket* r, const std::string& target, const std::string& wildcard, SOAData& sd)
{
DNSResourceRecord rr;
rr.qname=sd.qname;
rr.qtype=QType::SOA;
rr.content=serializeSOAData(sd);
rr.ttl=min(sd.ttl, sd.default_ttl);
rr.signttl=sd.ttl;
rr.domain_id=sd.domain_id;
rr.d_place=DNSResourceRecord::AUTHORITY;
rr.auth = 1;
rr.scopeMask = sd.scopeMask;
r->addRecord(rr);
if(d_dk.isSecuredZone(sd.qname))
addNSECX(p, r, target, wildcard, sd.qname, 4);
r->setRcode(RCode::NXDomain);
S.ringAccount("nxdomain-queries",p->qdomain+"/"+p->qtype.getName());
}
void PacketHandler::makeNOError(DNSPacket* p, DNSPacket* r, const std::string& target, const std::string& wildcard, SOAData& sd, int mode)
{
DNSResourceRecord rr;
rr.qname=sd.qname;
rr.qtype=QType::SOA;
rr.content=serializeSOAData(sd);