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pdns_recursor.cc
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pdns_recursor.cc
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/*
PowerDNS Versatile Database Driven Nameserver
Copyright (C) 2003 - 2014 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
Additionally, the license of this program contains a special
exception which allows to distribute the program in binary form when
it is linked against OpenSSL.
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 <netdb.h>
#include <sys/stat.h>
#include <unistd.h>
#include <boost/foreach.hpp>
#include "ws-recursor.hh"
#include <pthread.h>
#include "recpacketcache.hh"
#include "utility.hh"
#include "dns_random.hh"
#include <iostream>
#include <errno.h>
#include <boost/static_assert.hpp>
#include <map>
#include <set>
#include "recursor_cache.hh"
#include "cachecleaner.hh"
#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include "misc.hh"
#include "mtasker.hh"
#include <utility>
#include "arguments.hh"
#include "syncres.hh"
#include <fcntl.h>
#include <fstream>
#include "sstuff.hh"
#include <boost/tuple/tuple.hpp>
#include <boost/tuple/tuple_comparison.hpp>
#include <boost/shared_array.hpp>
#include <boost/lexical_cast.hpp>
#include <boost/function.hpp>
#include <boost/algorithm/string.hpp>
#include <netinet/tcp.h>
#include "dnsparser.hh"
#include "dnswriter.hh"
#include "dnsrecords.hh"
#include "zoneparser-tng.hh"
#include "rec_channel.hh"
#include "logger.hh"
#include "iputils.hh"
#include "mplexer.hh"
#include "config.h"
#include "lua-recursor.hh"
#include "version.hh"
#include "responsestats.hh"
#include "secpoll-recursor.hh"
#ifndef RECURSOR
#include "statbag.hh"
StatBag S;
#endif
__thread FDMultiplexer* t_fdm;
__thread unsigned int t_id;
unsigned int g_maxTCPPerClient;
unsigned int g_networkTimeoutMsec;
uint64_t g_latencyStatSize;
bool g_logCommonErrors;
bool g_anyToTcp;
uint16_t g_udpTruncationThreshold;
__thread shared_ptr<RecursorLua>* t_pdl;
__thread addrringbuf_t* t_remotes, *t_servfailremotes, *t_largeanswerremotes;
__thread boost::circular_buffer<pair<std::string, uint16_t> >* t_queryring, *t_servfailqueryring;
__thread shared_ptr<Regex>* t_traceRegex;
RecursorControlChannel s_rcc; // only active in thread 0
// for communicating with our threads
struct ThreadPipeSet
{
int writeToThread;
int readToThread;
int writeFromThread;
int readFromThread;
};
vector<ThreadPipeSet> g_pipes; // effectively readonly after startup
SyncRes::domainmap_t* g_initialDomainMap; // new threads needs this to be setup
#include "namespaces.hh"
__thread MemRecursorCache* t_RC;
__thread RecursorPacketCache* t_packetCache;
RecursorStats g_stats;
bool g_quiet;
bool g_weDistributeQueries; // if true, only 1 thread listens on the incoming query sockets
__thread NetmaskGroup* t_allowFrom;
static NetmaskGroup* g_initialAllowFrom; // new thread needs to be setup with this
NetmaskGroup* g_dontQuery;
string s_programname="pdns_recursor";
typedef vector<int> tcpListenSockets_t;
tcpListenSockets_t g_tcpListenSockets; // shared across threads, but this is fine, never written to from a thread. All threads listen on all sockets
int g_tcpTimeout;
unsigned int g_maxMThreads;
struct timeval g_now; // timestamp, updated (too) frequently
typedef map<int, ComboAddress> listenSocketsAddresses_t; // is shared across all threads right now
listenSocketsAddresses_t g_listenSocketsAddresses; // is shared across all threads right now
__thread MT_t* MT; // the big MTasker
unsigned int g_numThreads;
#define LOCAL_NETS "127.0.0.0/8, 10.0.0.0/8, 100.64.0.0/10, 169.254.0.0/16, 192.168.0.0/16, 172.16.0.0/12, ::1/128, fc00::/7, fe80::/10"
// Bad Nets taken from both:
// http://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml
// and
// http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.xhtml
// where such a network may not be considered a valid destination
#define BAD_NETS "0.0.0.0/8, 192.0.0.0/24, 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24, 240.0.0.0/4, ::/96, ::ffff:0:0/96, 100::/64, 2001:db8::/32"
#define DONT_QUERY LOCAL_NETS ", " BAD_NETS
//! used to send information to a newborn mthread
struct DNSComboWriter {
DNSComboWriter(const char* data, uint16_t len, const struct timeval& now) : d_mdp(data, len), d_now(now),
d_tcp(false), d_socket(-1)
{}
MOADNSParser d_mdp;
void setRemote(const ComboAddress* sa)
{
d_remote=*sa;
}
void setLocal(const ComboAddress& sa)
{
d_local=sa;
}
void setSocket(int sock)
{
d_socket=sock;
}
string getRemote() const
{
return d_remote.toString();
}
struct timeval d_now;
ComboAddress d_remote, d_local;
bool d_tcp;
int d_socket;
shared_ptr<TCPConnection> d_tcpConnection;
};
ArgvMap &arg()
{
static ArgvMap theArg;
return theArg;
}
void handleTCPClientWritable(int fd, FDMultiplexer::funcparam_t& var);
// -1 is error, 0 is timeout, 1 is success
int asendtcp(const string& data, Socket* sock)
{
PacketID pident;
pident.sock=sock;
pident.outMSG=data;
t_fdm->addWriteFD(sock->getHandle(), handleTCPClientWritable, pident);
string packet;
int ret=MT->waitEvent(pident, &packet, g_networkTimeoutMsec);
if(!ret || ret==-1) { // timeout
t_fdm->removeWriteFD(sock->getHandle());
}
else if(packet.size() !=data.size()) { // main loop tells us what it sent out, or empty in case of an error
return -1;
}
return ret;
}
void handleTCPClientReadable(int fd, FDMultiplexer::funcparam_t& var);
// -1 is error, 0 is timeout, 1 is success
int arecvtcp(string& data, int len, Socket* sock, bool incompleteOkay)
{
data.clear();
PacketID pident;
pident.sock=sock;
pident.inNeeded=len;
pident.inIncompleteOkay=incompleteOkay;
t_fdm->addReadFD(sock->getHandle(), handleTCPClientReadable, pident);
int ret=MT->waitEvent(pident,&data, g_networkTimeoutMsec);
if(!ret || ret==-1) { // timeout
t_fdm->removeReadFD(sock->getHandle());
}
else if(data.empty()) {// error, EOF or other
return -1;
}
return ret;
}
vector<ComboAddress> g_localQueryAddresses4, g_localQueryAddresses6;
const ComboAddress g_local4("0.0.0.0"), g_local6("::");
//! pick a random query local address
ComboAddress getQueryLocalAddress(int family, uint16_t port)
{
ComboAddress ret;
if(family==AF_INET) {
if(g_localQueryAddresses4.empty())
ret = g_local4;
else
ret = g_localQueryAddresses4[dns_random(g_localQueryAddresses4.size())];
ret.sin4.sin_port = htons(port);
}
else {
if(g_localQueryAddresses6.empty())
ret = g_local6;
else
ret = g_localQueryAddresses6[dns_random(g_localQueryAddresses6.size())];
ret.sin6.sin6_port = htons(port);
}
return ret;
}
void handleUDPServerResponse(int fd, FDMultiplexer::funcparam_t&);
void setSocketBuffer(int fd, int optname, uint32_t size)
{
uint32_t psize=0;
socklen_t len=sizeof(psize);
if(!getsockopt(fd, SOL_SOCKET, optname, (char*)&psize, &len) && psize > size) {
L<<Logger::Error<<"Not decreasing socket buffer size from "<<psize<<" to "<<size<<endl;
return;
}
if (setsockopt(fd, SOL_SOCKET, optname, (char*)&size, sizeof(size)) < 0 )
L<<Logger::Error<<"Warning: unable to raise socket buffer size to "<<size<<": "<<strerror(errno)<<endl;
}
static void setSocketReceiveBuffer(int fd, uint32_t size)
{
setSocketBuffer(fd, SO_RCVBUF, size);
}
static void setSocketSendBuffer(int fd, uint32_t size)
{
setSocketBuffer(fd, SO_SNDBUF, size);
}
// you can ask this class for a UDP socket to send a query from
// this socket is not yours, don't even think about deleting it
// but after you call 'returnSocket' on it, don't assume anything anymore
class UDPClientSocks
{
unsigned int d_numsocks;
public:
UDPClientSocks() : d_numsocks(0)
{
}
typedef set<int> socks_t;
socks_t d_socks;
// returning -1 means: temporary OS error (ie, out of files), -2 means OS error
int getSocket(const ComboAddress& toaddr, int* fd)
{
*fd=makeClientSocket(toaddr.sin4.sin_family);
if(*fd < 0) // temporary error - receive exception otherwise
return -1;
if(connect(*fd, (struct sockaddr*)(&toaddr), toaddr.getSocklen()) < 0) {
int err = errno;
// returnSocket(*fd);
Utility::closesocket(*fd);
if(err==ENETUNREACH) // Seth "My Interfaces Are Like A Yo Yo" Arnold special
return -2;
return -1;
}
d_socks.insert(*fd);
d_numsocks++;
return 0;
}
void returnSocket(int fd)
{
socks_t::iterator i=d_socks.find(fd);
if(i==d_socks.end()) {
throw PDNSException("Trying to return a socket (fd="+lexical_cast<string>(fd)+") not in the pool");
}
returnSocketLocked(i);
}
// return a socket to the pool, or simply erase it
void returnSocketLocked(socks_t::iterator& i)
{
if(i==d_socks.end()) {
throw PDNSException("Trying to return a socket not in the pool");
}
try {
t_fdm->removeReadFD(*i);
}
catch(FDMultiplexerException& e) {
// we sometimes return a socket that has not yet been assigned to t_fdm
}
Utility::closesocket(*i);
d_socks.erase(i++);
--d_numsocks;
}
// returns -1 for errors which might go away, throws for ones that won't
static int makeClientSocket(int family)
{
int ret=(int)socket(family, SOCK_DGRAM, 0 ); // turns out that setting CLO_EXEC and NONBLOCK from here is not a performance win on Linux (oddly enough)
if(ret < 0 && errno==EMFILE) // this is not a catastrophic error
return ret;
if(ret<0)
throw PDNSException("Making a socket for resolver (family = "+lexical_cast<string>(family)+"): "+stringerror());
Utility::setCloseOnExec(ret);
int tries=10;
while(--tries) {
uint16_t port;
if(tries==1) // fall back to kernel 'random'
port = 0;
else
port = 1025 + dns_random(64510);
ComboAddress sin=getQueryLocalAddress(family, port); // does htons for us
if (::bind(ret, (struct sockaddr *)&sin, sin.getSocklen()) >= 0)
break;
}
if(!tries)
throw PDNSException("Resolver binding to local query client socket: "+stringerror());
Utility::setNonBlocking(ret);
return ret;
}
};
static __thread UDPClientSocks* t_udpclientsocks;
/* these two functions are used by LWRes */
// -2 is OS error, -1 is error that depends on the remote, > 0 is success
int asendto(const char *data, int len, int flags,
const ComboAddress& toaddr, uint16_t id, const string& domain, uint16_t qtype, int* fd)
{
PacketID pident;
pident.domain = domain;
pident.remote = toaddr;
pident.type = qtype;
// see if there is an existing outstanding request we can chain on to, using partial equivalence function
pair<MT_t::waiters_t::iterator, MT_t::waiters_t::iterator> chain=MT->d_waiters.equal_range(pident, PacketIDBirthdayCompare());
for(; chain.first != chain.second; chain.first++) {
if(chain.first->key.fd > -1) { // don't chain onto existing chained waiter!
/*
cerr<<"Orig: "<<pident.domain<<", "<<pident.remote.toString()<<", id="<<id<<endl;
cerr<<"Had hit: "<< chain.first->key.domain<<", "<<chain.first->key.remote.toString()<<", id="<<chain.first->key.id
<<", count="<<chain.first->key.chain.size()<<", origfd: "<<chain.first->key.fd<<endl;
*/
chain.first->key.chain.insert(id); // we can chain
*fd=-1; // gets used in waitEvent / sendEvent later on
return 1;
}
}
int ret=t_udpclientsocks->getSocket(toaddr, fd);
if(ret < 0)
return ret;
pident.fd=*fd;
pident.id=id;
t_fdm->addReadFD(*fd, handleUDPServerResponse, pident);
ret = send(*fd, data, len, 0);
int tmp = errno;
if(ret < 0)
t_udpclientsocks->returnSocket(*fd);
errno = tmp; // this is for logging purposes only
return ret;
}
// -1 is error, 0 is timeout, 1 is success
int arecvfrom(char *data, int len, int flags, const ComboAddress& fromaddr, int *d_len,
uint16_t id, const string& domain, uint16_t qtype, int fd, struct timeval* now)
{
static optional<unsigned int> nearMissLimit;
if(!nearMissLimit)
nearMissLimit=::arg().asNum("spoof-nearmiss-max");
PacketID pident;
pident.fd=fd;
pident.id=id;
pident.domain=domain;
pident.type = qtype;
pident.remote=fromaddr;
string packet;
int ret=MT->waitEvent(pident, &packet, g_networkTimeoutMsec, now);
if(ret > 0) {
if(packet.empty()) // means "error"
return -1;
*d_len=(int)packet.size();
memcpy(data,packet.c_str(),min(len,*d_len));
if(*nearMissLimit && pident.nearMisses > *nearMissLimit) {
L<<Logger::Error<<"Too many ("<<pident.nearMisses<<" > "<<*nearMissLimit<<") bogus answers for '"<<domain<<"' from "<<fromaddr.toString()<<", assuming spoof attempt."<<endl;
g_stats.spoofCount++;
return -1;
}
}
else {
if(fd >= 0)
t_udpclientsocks->returnSocket(fd);
}
return ret;
}
string s_pidfname;
static void writePid(void)
{
ofstream of(s_pidfname.c_str(), std::ios_base::app);
if(of)
of<< Utility::getpid() <<endl;
else
L<<Logger::Error<<"Requested to write pid for "<<Utility::getpid()<<" to "<<s_pidfname<<" failed: "<<strerror(errno)<<endl;
}
typedef map<ComboAddress, uint32_t, ComboAddress::addressOnlyLessThan> tcpClientCounts_t;
tcpClientCounts_t __thread* t_tcpClientCounts;
TCPConnection::TCPConnection(int fd, const ComboAddress& addr) : d_remote(addr), d_fd(fd)
{
++s_currentConnections;
(*t_tcpClientCounts)[d_remote]++;
}
TCPConnection::~TCPConnection()
{
if(Utility::closesocket(d_fd) < 0)
unixDie("closing socket for TCPConnection");
if(t_tcpClientCounts->count(d_remote) && !(*t_tcpClientCounts)[d_remote]--)
t_tcpClientCounts->erase(d_remote);
--s_currentConnections;
}
AtomicCounter TCPConnection::s_currentConnections;
void handleRunningTCPQuestion(int fd, FDMultiplexer::funcparam_t& var);
// the idea is, only do things that depend on the *response* here. Incoming accounting is on incoming.
void updateResponseStats(int res, const ComboAddress& remote, unsigned int packetsize, const std::string* query, uint16_t qtype)
{
if(packetsize > 1000 && t_largeanswerremotes)
t_largeanswerremotes->push_back(remote);
switch(res) {
case RCode::ServFail:
if(t_servfailremotes) {
t_servfailremotes->push_back(remote);
if(query) // packet cache
t_servfailqueryring->push_back(make_pair(*query, qtype));
}
g_stats.servFails++;
break;
case RCode::NXDomain:
g_stats.nxDomains++;
break;
case RCode::NoError:
g_stats.noErrors++;
break;
}
}
ResponseStats g_rs;
static string makeLoginfo(DNSComboWriter* dc)
try
{
return "("+dc->d_mdp.d_qname+"/"+DNSRecordContent::NumberToType(dc->d_mdp.d_qtype)+" from "+(dc->d_remote.toString())+")";
}
catch(...)
{
return "Exception making error message for exception";
}
void startDoResolve(void *p)
{
DNSComboWriter* dc=(DNSComboWriter *)p;
try {
t_queryring->push_back(make_pair(dc->d_mdp.d_qname, dc->d_mdp.d_qtype));
uint32_t maxanswersize= dc->d_tcp ? 65535 : min((uint16_t) 512, g_udpTruncationThreshold);
EDNSOpts edo;
if(getEDNSOpts(dc->d_mdp, &edo) && !dc->d_tcp) {
maxanswersize = min(edo.d_packetsize, g_udpTruncationThreshold);
}
ComboAddress local;
listenSocketsAddresses_t::const_iterator lociter;
vector<DNSResourceRecord> ret;
vector<uint8_t> packet;
DNSPacketWriter pw(packet, dc->d_mdp.d_qname, dc->d_mdp.d_qtype, dc->d_mdp.d_qclass);
pw.getHeader()->aa=0;
pw.getHeader()->ra=1;
pw.getHeader()->qr=1;
pw.getHeader()->tc=0;
pw.getHeader()->id=dc->d_mdp.d_header.id;
pw.getHeader()->rd=dc->d_mdp.d_header.rd;
uint32_t minTTL=std::numeric_limits<uint32_t>::max();
SyncRes sr(dc->d_now);
if(t_pdl) {
sr.setLuaEngine(*t_pdl);
sr.d_requestor=dc->d_remote;
}
bool tracedQuery=false; // we could consider letting Lua know about this too
bool variableAnswer = false;
int res;
if(dc->d_mdp.d_qtype==QType::ANY && !dc->d_tcp && g_anyToTcp) {
pw.getHeader()->tc = 1;
res = 0;
variableAnswer = true;
goto sendit;
}
if(t_traceRegex->get() && (*t_traceRegex)->match(dc->d_mdp.d_qname)) {
sr.setLogMode(SyncRes::Store);
tracedQuery=true;
}
if(!g_quiet || tracedQuery)
L<<Logger::Warning<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] " << (dc->d_tcp ? "TCP " : "") << "question for '"<<dc->d_mdp.d_qname<<"|"
<<DNSRecordContent::NumberToType(dc->d_mdp.d_qtype)<<"' from "<<dc->getRemote()<<endl;
sr.setId(MT->getTid());
if(!dc->d_mdp.d_header.rd)
sr.setCacheOnly();
local.sin4.sin_family = dc->d_remote.sin4.sin_family;
lociter = g_listenSocketsAddresses.find(dc->d_socket);
if(lociter != g_listenSocketsAddresses.end()) {
local = lociter->second;
}
else {
socklen_t len = local.getSocklen();
getsockname(dc->d_socket, (sockaddr*)&local, &len); // if this fails, we're ok with it
}
// if there is a RecursorLua active, and it 'took' the query in preResolve, we don't launch beginResolve
if(!t_pdl->get() || !(*t_pdl)->preresolve(dc->d_remote, local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer)) {
try {
res = sr.beginResolve(dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), dc->d_mdp.d_qclass, ret);
}
catch(ImmediateServFailException &e) {
if(g_logCommonErrors)
L<<Logger::Notice<<"Sending SERVFAIL to "<<dc->getRemote()<<" during resolve of '"<<dc->d_mdp.d_qname<<"' because: "<<e.reason<<endl;
res = RCode::ServFail;
}
if(t_pdl->get()) {
if(res == RCode::NoError) {
vector<DNSResourceRecord>::const_iterator i;
for(i=ret.begin(); i!=ret.end(); ++i)
if(i->qtype.getCode() == dc->d_mdp.d_qtype && i->d_place == DNSResourceRecord::ANSWER)
break;
if(i == ret.end())
(*t_pdl)->nodata(dc->d_remote,local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
}
else if(res == RCode::NXDomain)
(*t_pdl)->nxdomain(dc->d_remote,local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
(*t_pdl)->postresolve(dc->d_remote,local, dc->d_mdp.d_qname, QType(dc->d_mdp.d_qtype), ret, res, &variableAnswer);
}
}
if(res == RecursorBehaviour::DROP) {
g_stats.policyDrops++;
delete dc;
dc=0;
return;
}
if(tracedQuery || res == RecursorBehaviour::PASS || res == RCode::ServFail || pw.getHeader()->rcode == RCode::ServFail)
{
string trace(sr.getTrace());
if(!trace.empty()) {
vector<string> lines;
boost::split(lines, trace, boost::is_any_of("\n"));
BOOST_FOREACH(const string& line, lines) {
if(!line.empty())
L<<Logger::Warning<< line << endl;
}
}
}
if(res == RecursorBehaviour::PASS) {
pw.getHeader()->rcode=RCode::ServFail;
// no commit here, because no record
g_stats.servFails++;
}
else {
pw.getHeader()->rcode=res;
if(ret.size()) {
orderAndShuffle(ret);
for(vector<DNSResourceRecord>::const_iterator i=ret.begin(); i!=ret.end(); ++i) {
pw.startRecord(i->qname, i->qtype.getCode(), i->ttl, i->qclass, (DNSPacketWriter::Place)i->d_place);
minTTL = min(minTTL, i->ttl);
if(i->qtype.getCode() == QType::A) { // blast out A record w/o doing whole dnswriter thing
uint32_t ip=0;
IpToU32(i->content, &ip);
pw.xfr32BitInt(htonl(ip));
} else {
shared_ptr<DNSRecordContent> drc(DNSRecordContent::mastermake(i->qtype.getCode(), i->qclass, i->content));
drc->toPacket(pw);
}
if(pw.size() > maxanswersize) {
pw.rollback();
if(i->d_place==DNSResourceRecord::ANSWER) // only truncate if we actually omitted parts of the answer
{
pw.getHeader()->tc=1;
pw.truncate();
}
goto sendit; // need to jump over pw.commit
}
}
pw.commit();
}
}
sendit:;
g_rs.submitResponse(dc->d_mdp.d_qtype, packet.size(), !dc->d_tcp);
updateResponseStats(res, dc->d_remote, packet.size(), &dc->d_mdp.d_qname, dc->d_mdp.d_qtype);
if(!dc->d_tcp) {
struct msghdr msgh;
struct iovec iov;
char cbuf[256];
fillMSGHdr(&msgh, &iov, cbuf, 0, (char*)&*packet.begin(), packet.size(), &dc->d_remote);
if(dc->d_local.sin4.sin_family)
addCMsgSrcAddr(&msgh, cbuf, &dc->d_local);
sendmsg(dc->d_socket, &msgh, 0);
if(!SyncRes::s_nopacketcache && !variableAnswer ) {
t_packetCache->insertResponsePacket(string((const char*)&*packet.begin(), packet.size()),
g_now.tv_sec,
min(minTTL,
(pw.getHeader()->rcode == RCode::ServFail) ? SyncRes::s_packetcacheservfailttl : SyncRes::s_packetcachettl
)
);
}
}
else {
char buf[2];
buf[0]=packet.size()/256;
buf[1]=packet.size()%256;
Utility::iovec iov[2];
iov[0].iov_base=(void*)buf; iov[0].iov_len=2;
iov[1].iov_base=(void*)&*packet.begin(); iov[1].iov_len = packet.size();
int ret=Utility::writev(dc->d_socket, iov, 2);
bool hadError=true;
if(ret == 0)
L<<Logger::Error<<"EOF writing TCP answer to "<<dc->getRemote()<<endl;
else if(ret < 0 )
L<<Logger::Error<<"Error writing TCP answer to "<<dc->getRemote()<<": "<< strerror(errno) <<endl;
else if((unsigned int)ret != 2 + packet.size())
L<<Logger::Error<<"Oops, partial answer sent to "<<dc->getRemote()<<" for "<<dc->d_mdp.d_qname<<" (size="<< (2 + packet.size()) <<", sent "<<ret<<")"<<endl;
else
hadError=false;
// update tcp connection status, either by closing or moving to 'BYTE0'
if(hadError) {
// no need to remove us from FDM, we weren't there
dc->d_socket = -1;
}
else {
dc->d_tcpConnection->state=TCPConnection::BYTE0;
Utility::gettimeofday(&g_now, 0); // needs to be updated
t_fdm->addReadFD(dc->d_socket, handleRunningTCPQuestion, dc->d_tcpConnection);
t_fdm->setReadTTD(dc->d_socket, g_now, g_tcpTimeout);
}
}
if(!g_quiet) {
L<<Logger::Error<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] answer to "<<(dc->d_mdp.d_header.rd?"":"non-rd ")<<"question '"<<dc->d_mdp.d_qname<<"|"<<DNSRecordContent::NumberToType(dc->d_mdp.d_qtype);
L<<"': "<<ntohs(pw.getHeader()->ancount)<<" answers, "<<ntohs(pw.getHeader()->arcount)<<" additional, took "<<sr.d_outqueries<<" packets, "<<
sr.d_totUsec/1000.0<<" ms, "<<
sr.d_throttledqueries<<" throttled, "<<sr.d_timeouts<<" timeouts, "<<sr.d_tcpoutqueries<<" tcp connections, rcode="<<res<<endl;
}
sr.d_outqueries ? t_RC->cacheMisses++ : t_RC->cacheHits++;
float spent=makeFloat(sr.d_now-dc->d_now);
if(spent < 0.001)
g_stats.answers0_1++;
else if(spent < 0.010)
g_stats.answers1_10++;
else if(spent < 0.1)
g_stats.answers10_100++;
else if(spent < 1.0)
g_stats.answers100_1000++;
else
g_stats.answersSlow++;
uint64_t newLat=(uint64_t)(spent*1000000);
newLat = min(newLat,(uint64_t)(g_networkTimeoutMsec*1000)); // outliers of several minutes exist..
g_stats.avgLatencyUsec=(1-1.0/g_latencyStatSize)*g_stats.avgLatencyUsec + (float)newLat/g_latencyStatSize;
// no worries, we do this for packet cache hits elsewhere
// cout<<dc->d_mdp.d_qname<<"\t"<<MT->getUsec()<<"\t"<<sr.d_outqueries<<endl;
delete dc;
dc=0;
}
catch(PDNSException &ae) {
L<<Logger::Error<<"startDoResolve problem "<<makeLoginfo(dc)<<": "<<ae.reason<<endl;
delete dc;
}
catch(MOADNSException& e) {
L<<Logger::Error<<"DNS parser error "<<makeLoginfo(dc) <<": "<<dc->d_mdp.d_qname<<", "<<e.what()<<endl;
delete dc;
}
catch(std::exception& e) {
L<<Logger::Error<<"STL error "<< makeLoginfo(dc)<<": "<<e.what()<<endl;
delete dc;
}
catch(...) {
L<<Logger::Error<<"Any other exception in a resolver context "<< makeLoginfo(dc) <<endl;
}
g_stats.maxMThreadStackUsage = max(MT->getMaxStackUsage(), g_stats.maxMThreadStackUsage);
}
void makeControlChannelSocket(int processNum=-1)
{
string sockname=::arg()["socket-dir"]+"/"+s_programname;
if(processNum >= 0)
sockname += "."+lexical_cast<string>(processNum);
sockname+=".controlsocket";
s_rcc.listen(sockname);
int sockowner = -1;
int sockgroup = -1;
if (!::arg().isEmpty("socket-group"))
sockgroup=::arg().asGid("socket-group");
if (!::arg().isEmpty("socket-owner"))
sockowner=::arg().asUid("socket-owner");
if (sockgroup > -1 || sockowner > -1) {
if(chown(sockname.c_str(), sockowner, sockgroup) < 0) {
unixDie("Failed to chown control socket");
}
}
// do mode change if socket-mode is given
if(!::arg().isEmpty("socket-mode")) {
mode_t sockmode=::arg().asMode("socket-mode");
chmod(sockname.c_str(), sockmode);
}
}
void handleRunningTCPQuestion(int fd, FDMultiplexer::funcparam_t& var)
{
shared_ptr<TCPConnection> conn=any_cast<shared_ptr<TCPConnection> >(var);
if(conn->state==TCPConnection::BYTE0) {
int bytes=recv(conn->getFD(), conn->data, 2, 0);
if(bytes==1)
conn->state=TCPConnection::BYTE1;
if(bytes==2) {
conn->qlen=(((unsigned char)conn->data[0]) << 8)+ (unsigned char)conn->data[1];
conn->bytesread=0;
conn->state=TCPConnection::GETQUESTION;
}
if(!bytes || bytes < 0) {
t_fdm->removeReadFD(fd);
return;
}
}
else if(conn->state==TCPConnection::BYTE1) {
int bytes=recv(conn->getFD(), conn->data+1, 1, 0);
if(bytes==1) {
conn->state=TCPConnection::GETQUESTION;
conn->qlen=(((unsigned char)conn->data[0]) << 8)+ (unsigned char)conn->data[1];
conn->bytesread=0;
}
if(!bytes || bytes < 0) {
if(g_logCommonErrors)
L<<Logger::Error<<"TCP client "<< conn->d_remote.toString() <<" disconnected after first byte"<<endl;
t_fdm->removeReadFD(fd);
return;
}
}
else if(conn->state==TCPConnection::GETQUESTION) {
int bytes=recv(conn->getFD(), conn->data + conn->bytesread, conn->qlen - conn->bytesread, 0);
if(!bytes || bytes < 0) {
L<<Logger::Error<<"TCP client "<< conn->d_remote.toString() <<" disconnected while reading question body"<<endl;
t_fdm->removeReadFD(fd);
return;
}
conn->bytesread+=bytes;
if(conn->bytesread==conn->qlen) {
t_fdm->removeReadFD(fd); // should no longer awake ourselves when there is data to read
DNSComboWriter* dc=0;
try {
dc=new DNSComboWriter(conn->data, conn->qlen, g_now);
}
catch(MOADNSException &mde) {
g_stats.clientParseError++;
if(g_logCommonErrors)
L<<Logger::Error<<"Unable to parse packet from TCP client "<< conn->d_remote.toString() <<endl;
return;
}
dc->d_tcpConnection = conn; // carry the torch
dc->setSocket(conn->getFD()); // this is the only time a copy is made of the actual fd
dc->d_tcp=true;
dc->setRemote(&conn->d_remote);
if(dc->d_mdp.d_header.qr) {
delete dc;
L<<Logger::Error<<"Ignoring answer on server socket!"<<endl;
return;
}
if(dc->d_mdp.d_header.opcode) {
delete dc;
L<<Logger::Error<<"Ignoring non-query opcode on server socket!"<<endl;
return;
}
else {
++g_stats.qcounter;
++g_stats.tcpqcounter;
MT->makeThread(startDoResolve, dc); // deletes dc, will set state to BYTE0 again
return;
}
}
}
}
//! Handle new incoming TCP connection
void handleNewTCPQuestion(int fd, FDMultiplexer::funcparam_t& )
{
ComboAddress addr;
socklen_t addrlen=sizeof(addr);
int newsock=(int)accept(fd, (struct sockaddr*)&addr, &addrlen);
if(newsock>0) {
if(MT->numProcesses() > g_maxMThreads) {
g_stats.overCapacityDrops++;
Utility::closesocket(newsock);
return;
}
if(t_remotes)
t_remotes->push_back(addr);
if(t_allowFrom && !t_allowFrom->match(&addr)) {
if(!g_quiet)
L<<Logger::Error<<"["<<MT->getTid()<<"] dropping TCP query from "<<addr.toString()<<", address not matched by allow-from"<<endl;
g_stats.unauthorizedTCP++;
Utility::closesocket(newsock);
return;
}
if(g_maxTCPPerClient && t_tcpClientCounts->count(addr) && (*t_tcpClientCounts)[addr] >= g_maxTCPPerClient) {
g_stats.tcpClientOverflow++;
Utility::closesocket(newsock); // don't call TCPConnection::closeAndCleanup here - did not enter it in the counts yet!
return;
}
Utility::setNonBlocking(newsock);
shared_ptr<TCPConnection> tc(new TCPConnection(newsock, addr));
tc->state=TCPConnection::BYTE0;
t_fdm->addReadFD(tc->getFD(), handleRunningTCPQuestion, tc);
struct timeval now;
Utility::gettimeofday(&now, 0);
t_fdm->setReadTTD(tc->getFD(), now, g_tcpTimeout);
}
}
string* doProcessUDPQuestion(const std::string& question, const ComboAddress& fromaddr, const ComboAddress& destaddr, struct timeval tv, int fd)
{
struct timeval diff = g_now - tv;
double delta=(diff.tv_sec*1000 + diff.tv_usec/1000.0);
if(delta > 1000.0) {
g_stats.tooOldDrops++;
return 0;
}
++g_stats.qcounter;
if(fromaddr.sin4.sin_family==AF_INET6)
g_stats.ipv6qcounter++;
string response;
try {
uint32_t age;
if(!SyncRes::s_nopacketcache && t_packetCache->getResponsePacket(question, g_now.tv_sec, &response, &age)) {
if(!g_quiet)
L<<Logger::Notice<<t_id<< " question answered from packet cache from "<<fromaddr.toString()<<endl;
// t_queryring->push_back("packetcached");
g_stats.packetCacheHits++;
SyncRes::s_queries++;
ageDNSPacket(response, age);
struct msghdr msgh;
struct iovec iov;
char cbuf[256];
fillMSGHdr(&msgh, &iov, cbuf, 0, (char*)response.c_str(), response.length(), const_cast<ComboAddress*>(&fromaddr));
if(destaddr.sin4.sin_family) {
addCMsgSrcAddr(&msgh, cbuf, &destaddr);
}
sendmsg(fd, &msgh, 0);
if(response.length() >= sizeof(struct dnsheader)) {
struct dnsheader dh;
memcpy(&dh, response.c_str(), sizeof(dh));
updateResponseStats(dh.rcode, fromaddr, response.length(), 0, 0);
}
g_stats.avgLatencyUsec=(1-1.0/g_latencyStatSize)*g_stats.avgLatencyUsec + 0.0; // we assume 0 usec
return 0;
}
}
catch(std::exception& e) {
L<<Logger::Error<<"Error processing or aging answer packet: "<<e.what()<<endl;
return 0;
}
if(t_pdl->get()) {
if((*t_pdl)->ipfilter(fromaddr, destaddr)) {
if(!g_quiet)
L<<Logger::Notice<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] DROPPED question from "<<fromaddr.toStringWithPort()<<" based on policy"<<endl;
g_stats.policyDrops++;
return 0;
}
}
if(MT->numProcesses() > g_maxMThreads) {
if(!g_quiet)
L<<Logger::Notice<<t_id<<" ["<<MT->getTid()<<"/"<<MT->numProcesses()<<"] DROPPED question from "<<fromaddr.toStringWithPort()<<", over capacity"<<endl;
g_stats.overCapacityDrops++;
return 0;
}
DNSComboWriter* dc = new DNSComboWriter(question.c_str(), question.size(), g_now);
dc->setSocket(fd);
dc->setRemote(&fromaddr);
dc->setLocal(destaddr);