/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2016 ZeroTier, Inc. https://www.zerotier.com/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "../version.h"
#include "Constants.hpp"
#include "Peer.hpp"
#include "Node.hpp"
#include "Switch.hpp"
#include "Network.hpp"
#include "SelfAwareness.hpp"
#include "Cluster.hpp"
#include "Packet.hpp"
#ifndef AF_MAX
#if AF_INET > AF_INET6
#define AF_MAX AF_INET
#else
#define AF_MAX AF_INET6
#endif
#endif
namespace ZeroTier {
// Used to send varying values for NAT keepalive
static uint32_t _natKeepaliveBuf = 0;
Peer::Peer(const RuntimeEnvironment *renv,const Identity &myIdentity,const Identity &peerIdentity) :
_lastReceive(0),
_lastNontrivialReceive(0),
_lastTriedMemorizedPath(0),
_lastDirectPathPushSent(0),
_lastDirectPathPushReceive(0),
_lastCredentialRequestSent(0),
_lastWhoisRequestReceived(0),
_lastEchoRequestReceived(0),
_lastComRequestReceived(0),
_lastComRequestSent(0),
_lastCredentialsReceived(0),
_lastTrustEstablishedPacketReceived(0),
RR(renv),
_remoteClusterOptimal4(0),
_vProto(0),
_vMajor(0),
_vMinor(0),
_vRevision(0),
_id(peerIdentity),
_numPaths(0),
_latency(0),
_directPathPushCutoffCount(0),
_credentialsCutoffCount(0)
{
memset(_remoteClusterOptimal6,0,sizeof(_remoteClusterOptimal6));
if (!myIdentity.agree(peerIdentity,_key,ZT_PEER_SECRET_KEY_LENGTH))
throw std::runtime_error("new peer identity key agreement failed");
}
void Peer::received(
const SharedPtr<Path> &path,
const unsigned int hops,
const uint64_t packetId,
const Packet::Verb verb,
const uint64_t inRePacketId,
const Packet::Verb inReVerb,
const bool trustEstablished)
{
const uint64_t now = RR->node->now();
#ifdef ZT_ENABLE_CLUSTER
bool suboptimalPath = false;
if ((RR->cluster)&&(hops == 0)) {
// Note: findBetterEndpoint() is first since we still want to check
// for a better endpoint even if we don't actually send a redirect.
InetAddress redirectTo;
if ( (verb != Packet::VERB_OK) && (verb != Packet::VERB_ERROR) && (verb != Packet::VERB_RENDEZVOUS) && (verb != Packet::VERB_PUSH_DIRECT_PATHS) && (RR->cluster->findBetterEndpoint(redirectTo,_id.address(),path->address(),false)) ) {
if (_vProto >= 5) {
// For newer peers we can send a more idiomatic verb: PUSH_DIRECT_PATHS.
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_PUSH_DIRECT_PATHS);
outp.append((uint16_t)1); // count == 1
outp.append((uint8_t)ZT_PUSH_DIRECT_PATHS_FLAG_CLUSTER_REDIRECT); // flags: cluster redirect
outp.append((uint16_t)0); // no extensions
if (redirectTo.ss_family == AF_INET) {
outp.append((uint8_t)4);
outp.append((uint8_t)6);
outp.append(redirectTo.rawIpData(),4);
} else {
outp.append((uint8_t)6);
outp.append((uint8_t)18);
outp.append(redirectTo.rawIpData(),16);
}
outp.append((uint16_t)redirectTo.port());
outp.armor(_key,true);
path->send(RR,outp.data(),outp.size(),now);
} else {
// For older peers we use RENDEZVOUS to coax them into contacting us elsewhere.
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_RENDEZVOUS);
outp.append((uint8_t)0); // no flags
RR->identity.address().appendTo(outp);
outp.append((uint16_t)redirectTo.port());
if (redirectTo.ss_family == AF_INET) {
outp.append((uint8_t)4);
outp.append(redirectTo.rawIpData(),4);
} else {
outp.append((uint8_t)16);
outp.append(redirectTo.rawIpData(),16);
}
outp.armor(_key,true);
path->send(RR,outp.data(),outp.size(),now);
}
suboptimalPath = true;
}
}
#endif
_lastReceive = now;
switch (verb) {
case Packet::VERB_FRAME:
case Packet::VERB_EXT_FRAME:
case Packet::VERB_NETWORK_CONFIG_REQUEST:
case Packet::VERB_NETWORK_CONFIG:
case Packet::VERB_MULTICAST_FRAME:
_lastNontrivialReceive = now;
break;
default: break;
}
if (trustEstablished) {
_lastTrustEstablishedPacketReceived = now;
path->trustedPacketReceived(now);
}
if (hops == 0) {
bool pathIsConfirmed = false;
{
Mutex::Lock _l(_paths_m);
for(unsigned int p=0;p<_numPaths;++p) {
if (_paths[p].path->address() == path->address()) {
_paths[p].lastReceive = now;
_paths[p].path = path; // local address may have changed!
#ifdef ZT_ENABLE_CLUSTER
_paths[p].localClusterSuboptimal = suboptimalPath;
#endif
pathIsConfirmed = true;
break;
}
}
}
if ( (!pathIsConfirmed) && (RR->node->shouldUsePathForZeroTierTraffic(_id.address(),path->localAddress(),path->address())) ) {
if (verb == Packet::VERB_OK) {
Mutex::Lock _l(_paths_m);
// Since this is a new path, figure out where to put it (possibly replacing an old/dead one)
unsigned int slot;
if (_numPaths < ZT_MAX_PEER_NETWORK_PATHS) {
slot = _numPaths++;
} else {
// First try to replace the worst within the same address family, if possible
int worstSlot = -1;
uint64_t worstScore = 0xffffffffffffffffULL;
for(unsigned int p=0;p<_numPaths;++p) {
if (_paths[p].path->address().ss_family == path->address().ss_family) {
const uint64_t s = _pathScore(p,now);
if (s < worstScore) {
worstScore = s;
worstSlot = (int)p;
}
}
}
if (worstSlot >= 0) {
slot = (unsigned int)worstSlot;
} else {
// If we can't find one with the same family, replace the worst of any family
slot = ZT_MAX_PEER_NETWORK_PATHS - 1;
for(unsigned int p=0;p<_numPaths;++p) {
const uint64_t s = _pathScore(p,now);
if (s < worstScore) {
worstScore = s;
slot = p;
}
}
}
}
_paths[slot].lastReceive = now;
_paths[slot].path = path;
#ifdef ZT_ENABLE_CLUSTER
_paths[slot].localClusterSuboptimal = suboptimalPath;
if (RR->cluster)
RR->cluster->broadcastHavePeer(_id);
#endif
} else {
TRACE("got %s via unknown path %s(%s), confirming...",Packet::verbString(verb),_id.address().toString().c_str(),path->address().toString().c_str());
attemptToContactAt(path->localAddress(),path->address(),now);
path->sent(now);
}
}
} else if (trustEstablished) {
// Send PUSH_DIRECT_PATHS if hops>0 (relayed) and we have a trust relationship (common network membership)
#ifdef ZT_ENABLE_CLUSTER
// Cluster mode disables normal PUSH_DIRECT_PATHS in favor of cluster-based peer redirection
const bool haveCluster = (RR->cluster);
#else
const bool haveCluster = false;
#endif
if ( ((now - _lastDirectPathPushSent) >= ZT_DIRECT_PATH_PUSH_INTERVAL) && (!haveCluster) ) {
_lastDirectPathPushSent = now;
std::vector<InetAddress> pathsToPush;
std::vector<InetAddress> dps(RR->node->directPaths());
for(std::vector<InetAddress>::const_iterator i(dps.begin());i!=dps.end();++i)
pathsToPush.push_back(*i);
std::vector<InetAddress> sym(RR->sa->getSymmetricNatPredictions());
for(unsigned long i=0,added=0;i<sym.size();++i) {
InetAddress tmp(sym[(unsigned long)RR->node->prng() % sym.size()]);
if (std::find(pathsToPush.begin(),pathsToPush.end(),tmp) == pathsToPush.end()) {
pathsToPush.push_back(tmp);
if (++added >= ZT_PUSH_DIRECT_PATHS_MAX_PER_SCOPE_AND_FAMILY)
break;
}
}
if (pathsToPush.size() > 0) {
#ifdef ZT_TRACE
std::string ps;
for(std::vector<InetAddress>::const_iterator p(pathsToPush.begin());p!=pathsToPush.end();++p) {
if (ps.length() > 0)
ps.push_back(',');
ps.append(p->toString());
}
TRACE("pushing %u direct paths to %s: %s",(unsigned int)pathsToPush.size(),_id.address().toString().c_str(),ps.c_str());
#endif
std::vector<InetAddress>::const_iterator p(pathsToPush.begin());
while (p != pathsToPush.end()) {
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_PUSH_DIRECT_PATHS);
outp.addSize(2); // leave room for count
unsigned int count = 0;
while ((p != pathsToPush.end())&&((outp.size() + 24) < 1200)) {
uint8_t addressType = 4;
switch(p->ss_family) {
case AF_INET:
break;
case AF_INET6:
addressType = 6;
break;
default: // we currently only push IP addresses
++p;
continue;
}
outp.append((uint8_t)0); // no flags
outp.append((uint16_t)0); // no extensions
outp.append(addressType);
outp.append((uint8_t)((addressType == 4) ? 6 : 18));
outp.append(p->rawIpData(),((addressType == 4) ? 4 : 16));
outp.append((uint16_t)p->port());
++count;
++p;
}
if (count) {
outp.setAt(ZT_PACKET_IDX_PAYLOAD,(uint16_t)count);
outp.armor(_key,true);
path->send(RR,outp.data(),outp.size(),now);
}
}
}
}
}
}
bool Peer::hasActivePathTo(uint64_t now,const InetAddress &addr) const
{
Mutex::Lock _l(_paths_m);
for(unsigned int p=0;p<_numPaths;++p) {
if ( (_paths[p].path->address() == addr) && ((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION) && (_paths[p].path->alive(now)) )
return true;
}
return false;
}
bool Peer::sendDirect(const void *data,unsigned int len,uint64_t now,bool forceEvenIfDead)
{
Mutex::Lock _l(_paths_m);
int bestp = -1;
uint64_t best = 0ULL;
for(unsigned int p=0;p<_numPaths;++p) {
if ( ((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION) && (_paths[p].path->alive(now)||(forceEvenIfDead)) ) {
const uint64_t s = _pathScore(p,now);
if (s >= best) {
best = s;
bestp = (int)p;
}
}
}
if (bestp >= 0) {
return _paths[bestp].path->send(RR,data,len,now);
} else {
return false;
}
}
SharedPtr<Path> Peer::getBestPath(uint64_t now,bool includeExpired)
{
Mutex::Lock _l(_paths_m);
int bestp = -1;
uint64_t best = 0ULL;
for(unsigned int p=0;p<_numPaths;++p) {
if ( ((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION) || (includeExpired) ) {
const uint64_t s = _pathScore(p,now);
if (s >= best) {
best = s;
bestp = (int)p;
}
}
}
if (bestp >= 0) {
return _paths[bestp].path;
} else {
return SharedPtr<Path>();
}
}
void Peer::sendHELLO(const InetAddress &localAddr,const InetAddress &atAddress,uint64_t now)
{
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_HELLO);
outp.append((unsigned char)ZT_PROTO_VERSION);
outp.append((unsigned char)ZEROTIER_ONE_VERSION_MAJOR);
outp.append((unsigned char)ZEROTIER_ONE_VERSION_MINOR);
outp.append((uint16_t)ZEROTIER_ONE_VERSION_REVISION);
outp.append(now);
RR->identity.serialize(outp,false);
atAddress.serialize(outp);
outp.append((uint64_t)RR->topology->worldId());
outp.append((uint64_t)RR->topology->worldTimestamp());
RR->node->expectReplyTo(outp.packetId());
outp.armor(_key,false); // HELLO is sent in the clear
RR->node->putPacket(localAddr,atAddress,outp.data(),outp.size());
}
void Peer::attemptToContactAt(const InetAddress &localAddr,const InetAddress &atAddress,uint64_t now)
{
if ( (_vProto >= 5) && ( !((_vMajor == 1)&&(_vMinor == 1)&&(_vRevision == 0)) ) ) {
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_ECHO);
RR->node->expectReplyTo(outp.packetId());
outp.armor(_key,true);
RR->node->putPacket(localAddr,atAddress,outp.data(),outp.size());
} else {
sendHELLO(localAddr,atAddress,now);
}
}
void Peer::tryMemorizedPath(uint64_t now)
{
if ((now - _lastTriedMemorizedPath) >= ZT_TRY_MEMORIZED_PATH_INTERVAL) {
_lastTriedMemorizedPath = now;
InetAddress mp;
if (RR->node->externalPathLookup(_id.address(),-1,mp))
attemptToContactAt(InetAddress(),mp,now);
}
}
bool Peer::doPingAndKeepalive(uint64_t now,int inetAddressFamily)
{
Mutex::Lock _l(_paths_m);
int bestp = -1;
uint64_t best = 0ULL;
for(unsigned int p=0;p<_numPaths;++p) {
if ( ((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION) && ((inetAddressFamily < 0)||((int)_paths[p].path->address().ss_family == inetAddressFamily)) ) {
const uint64_t s = _pathScore(p,now);
if (s >= best) {
best = s;
bestp = (int)p;
}
}
}
if (bestp >= 0) {
if ((now - _paths[bestp].lastReceive) >= ZT_PEER_PING_PERIOD) {
attemptToContactAt(_paths[bestp].path->localAddress(),_paths[bestp].path->address(),now);
_paths[bestp].path->sent(now);
} else if (_paths[bestp].path->needsHeartbeat(now)) {
_natKeepaliveBuf += (uint32_t)((now * 0x9e3779b1) >> 1); // tumble this around to send constantly varying (meaningless) payloads
_paths[bestp].path->send(RR,&_natKeepaliveBuf,sizeof(_natKeepaliveBuf),now);
}
return true;
} else {
return false;
}
}
bool Peer::hasActiveDirectPath(uint64_t now) const
{
Mutex::Lock _l(_paths_m);
for(unsigned int p=0;p<_numPaths;++p) {
if (((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION)&&(_paths[p].path->alive(now)))
return true;
}
return false;
}
void Peer::resetWithinScope(InetAddress::IpScope scope,int inetAddressFamily,uint64_t now)
{
Mutex::Lock _l(_paths_m);
for(unsigned int p=0;p<_numPaths;++p) {
if ( (_paths[p].path->address().ss_family == inetAddressFamily) && (_paths[p].path->address().ipScope() == scope) ) {
attemptToContactAt(_paths[p].path->localAddress(),_paths[p].path->address(),now);
_paths[p].path->sent(now);
_paths[p].lastReceive = 0; // path will not be used unless it speaks again
}
}
}
void Peer::getBestActiveAddresses(uint64_t now,InetAddress &v4,InetAddress &v6) const
{
Mutex::Lock _l(_paths_m);
int bestp4 = -1,bestp6 = -1;
uint64_t best4 = 0ULL,best6 = 0ULL;
for(unsigned int p=0;p<_numPaths;++p) {
if ( ((now - _paths[p].lastReceive) <= ZT_PEER_PATH_EXPIRATION) && (_paths[p].path->alive(now)) ) {
if (_paths[p].path->address().ss_family == AF_INET) {
const uint64_t s = _pathScore(p,now);
if (s >= best4) {
best4 = s;
bestp4 = (int)p;
}
} else if (_paths[p].path->address().ss_family == AF_INET6) {
const uint64_t s = _pathScore(p,now);
if (s >= best6) {
best6 = s;
bestp6 = (int)p;
}
}
}
}
if (bestp4 >= 0)
v4 = _paths[bestp4].path->address();
if (bestp6 >= 0)
v6 = _paths[bestp6].path->address();
}
} // namespace ZeroTier