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/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2018 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/>.
*
* --
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial closed-source software that incorporates or links
* directly against ZeroTier software without disclosing the source code
* of your own application.
*/
#include "../version.h"
#include "Constants.hpp"
#include "Peer.hpp"
#include "Node.hpp"
#include "Switch.hpp"
#include "Network.hpp"
#include "SelfAwareness.hpp"
#include "Packet.hpp"
#include "Trace.hpp"
#include "InetAddress.hpp"
namespace ZeroTier {
Peer::Peer(const RuntimeEnvironment *renv,const Identity &myIdentity,const Identity &peerIdentity) :
RR(renv),
_lastReceive(0),
_lastNontrivialReceive(0),
_lastTriedMemorizedPath(0),
_lastDirectPathPushSent(0),
_lastDirectPathPushReceive(0),
_lastCredentialRequestSent(0),
_lastWhoisRequestReceived(0),
_lastEchoRequestReceived(0),
_lastComRequestReceived(0),
_lastComRequestSent(0),
_lastCredentialsReceived(0),
_lastTrustEstablishedPacketReceived(0),
_lastSentFullHello(0),
_vProto(0),
_vMajor(0),
_vMinor(0),
_vRevision(0),
_id(peerIdentity),
_directPathPushCutoffCount(0),
_credentialsCutoffCount(0)
{
if (!myIdentity.agree(peerIdentity,_key,ZT_PEER_SECRET_KEY_LENGTH))
throw ZT_EXCEPTION_INVALID_ARGUMENT;
}
void Peer::received(
void *tPtr,
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 networkId)
{
const int64_t now = RR->node->now();
_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) {
// If this is a direct packet (no hops), update existing paths or learn new ones
bool havePath = false;
{
Mutex::Lock _l(_paths_m);
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if (_paths[i].p == path) {
_paths[i].lr = now;
havePath = true;
break;
}
} else break;
}
}
bool attemptToContact = false;
if ((!havePath)&&(RR->node->shouldUsePathForZeroTierTraffic(tPtr,_id.address(),path->localSocket(),path->address()))) {
Mutex::Lock _l(_paths_m);
// Paths are redunant if they duplicate an alive path to the same IP or
// with the same local socket and address family.
bool redundant = false;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if ( (_paths[i].p->alive(now)) && ( ((_paths[i].p->localSocket() == path->localSocket())&&(_paths[i].p->address().ss_family == path->address().ss_family)) || (_paths[i].p->address().ipsEqual2(path->address())) ) ) {
redundant = true;
break;
}
} else break;
}
if (!redundant) {
unsigned int replacePath = ZT_MAX_PEER_NETWORK_PATHS;
int replacePathQuality = 0;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
const int q = _paths[i].p->quality(now);
if (q > replacePathQuality) {
replacePathQuality = q;
replacePath = i;
}
} else {
replacePath = i;
break;
}
}
if (replacePath != ZT_MAX_PEER_NETWORK_PATHS) {
if (verb == Packet::VERB_OK) {
RR->t->peerLearnedNewPath(tPtr,networkId,*this,path,packetId);
_paths[replacePath].lr = now;
_paths[replacePath].p = path;
_paths[replacePath].priority = 1;
} else {
attemptToContact = true;
}
}
}
}
if (attemptToContact) {
attemptToContactAt(tPtr,path->localSocket(),path->address(),now,true);
path->sent(now);
RR->t->peerConfirmingUnknownPath(tPtr,networkId,*this,path,packetId,verb);
}
}
// If we have a trust relationship periodically push a message enumerating
// all known external addresses for ourselves. We now do this even if we
// have a current path since we'll want to use new ones too.
if (this->trustEstablished(now)) {
if ((now - _lastDirectPathPushSent) >= ZT_DIRECT_PATH_PUSH_INTERVAL) {
_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);
// Do symmetric NAT prediction if we are communicating indirectly.
if (hops > 0) {
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) {
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,tPtr,outp.data(),outp.size(),now);
}
}
}
}
}
}
SharedPtr<Path> Peer::getBestPath(int64_t now,bool includeExpired) const
{
Mutex::Lock _l(_paths_m);
unsigned int bestPath = ZT_MAX_PEER_NETWORK_PATHS;
long bestPathQuality = 2147483647;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if ((includeExpired)||((now - _paths[i].lr) < ZT_PEER_PATH_EXPIRATION)) {
const long q = _paths[i].p->quality(now) / _paths[i].priority;
if (q <= bestPathQuality) {
bestPathQuality = q;
bestPath = i;
}
}
} else break;
}
if (bestPath != ZT_MAX_PEER_NETWORK_PATHS)
return _paths[bestPath].p;
return SharedPtr<Path>();
}
void Peer::introduce(void *const tPtr,const int64_t now,const SharedPtr<Peer> &other) const
{
unsigned int myBestV4ByScope[ZT_INETADDRESS_MAX_SCOPE+1];
unsigned int myBestV6ByScope[ZT_INETADDRESS_MAX_SCOPE+1];
long myBestV4QualityByScope[ZT_INETADDRESS_MAX_SCOPE+1];
long myBestV6QualityByScope[ZT_INETADDRESS_MAX_SCOPE+1];
unsigned int theirBestV4ByScope[ZT_INETADDRESS_MAX_SCOPE+1];
unsigned int theirBestV6ByScope[ZT_INETADDRESS_MAX_SCOPE+1];
long theirBestV4QualityByScope[ZT_INETADDRESS_MAX_SCOPE+1];
long theirBestV6QualityByScope[ZT_INETADDRESS_MAX_SCOPE+1];
for(int i=0;i<=ZT_INETADDRESS_MAX_SCOPE;++i) {
myBestV4ByScope[i] = ZT_MAX_PEER_NETWORK_PATHS;
myBestV6ByScope[i] = ZT_MAX_PEER_NETWORK_PATHS;
myBestV4QualityByScope[i] = 2147483647;
myBestV6QualityByScope[i] = 2147483647;
theirBestV4ByScope[i] = ZT_MAX_PEER_NETWORK_PATHS;
theirBestV6ByScope[i] = ZT_MAX_PEER_NETWORK_PATHS;
theirBestV4QualityByScope[i] = 2147483647;
theirBestV6QualityByScope[i] = 2147483647;
}
Mutex::Lock _l1(_paths_m);
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
const long q = _paths[i].p->quality(now) / _paths[i].priority;
const unsigned int s = (unsigned int)_paths[i].p->ipScope();
switch(_paths[i].p->address().ss_family) {
case AF_INET:
if (q <= myBestV4QualityByScope[s]) {
myBestV4QualityByScope[s] = q;
myBestV4ByScope[s] = i;
}
break;
case AF_INET6:
if (q <= myBestV6QualityByScope[s]) {
myBestV6QualityByScope[s] = q;
myBestV6ByScope[s] = i;
}
break;
}
} else break;
}
Mutex::Lock _l2(other->_paths_m);
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (other->_paths[i].p) {
const long q = other->_paths[i].p->quality(now) / other->_paths[i].priority;
const unsigned int s = (unsigned int)other->_paths[i].p->ipScope();
switch(other->_paths[i].p->address().ss_family) {
case AF_INET:
if (q <= theirBestV4QualityByScope[s]) {
theirBestV4QualityByScope[s] = q;
theirBestV4ByScope[s] = i;
}
break;
case AF_INET6:
if (q <= theirBestV6QualityByScope[s]) {
theirBestV6QualityByScope[s] = q;
theirBestV6ByScope[s] = i;
}
break;
}
} else break;
}
unsigned int mine = ZT_MAX_PEER_NETWORK_PATHS;
unsigned int theirs = ZT_MAX_PEER_NETWORK_PATHS;
for(int s=ZT_INETADDRESS_MAX_SCOPE;s>=0;--s) {
if ((myBestV6ByScope[s] != ZT_MAX_PEER_NETWORK_PATHS)&&(theirBestV6ByScope[s] != ZT_MAX_PEER_NETWORK_PATHS)) {
mine = myBestV6ByScope[s];
theirs = theirBestV6ByScope[s];
break;
}
if ((myBestV4ByScope[s] != ZT_MAX_PEER_NETWORK_PATHS)&&(theirBestV4ByScope[s] != ZT_MAX_PEER_NETWORK_PATHS)) {
mine = myBestV4ByScope[s];
theirs = theirBestV4ByScope[s];
break;
}
}
if (mine != ZT_MAX_PEER_NETWORK_PATHS) {
unsigned int alt = (unsigned int)RR->node->prng() & 1; // randomize which hint we send first for black magickal NAT-t reasons
const unsigned int completed = alt + 2;
while (alt != completed) {
if ((alt & 1) == 0) {
Packet outp(_id.address(),RR->identity.address(),Packet::VERB_RENDEZVOUS);
outp.append((uint8_t)0);
other->_id.address().appendTo(outp);
outp.append((uint16_t)other->_paths[theirs].p->address().port());
if (other->_paths[theirs].p->address().ss_family == AF_INET6) {
outp.append((uint8_t)16);
outp.append(other->_paths[theirs].p->address().rawIpData(),16);
} else {
outp.append((uint8_t)4);
outp.append(other->_paths[theirs].p->address().rawIpData(),4);
}
outp.armor(_key,true);
_paths[mine].p->send(RR,tPtr,outp.data(),outp.size(),now);
} else {
Packet outp(other->_id.address(),RR->identity.address(),Packet::VERB_RENDEZVOUS);
outp.append((uint8_t)0);
_id.address().appendTo(outp);
outp.append((uint16_t)_paths[mine].p->address().port());
if (_paths[mine].p->address().ss_family == AF_INET6) {
outp.append((uint8_t)16);
outp.append(_paths[mine].p->address().rawIpData(),16);
} else {
outp.append((uint8_t)4);
outp.append(_paths[mine].p->address().rawIpData(),4);
}
outp.armor(other->_key,true);
other->_paths[theirs].p->send(RR,tPtr,outp.data(),outp.size(),now);
}
++alt;
}
}
}
void Peer::sendHELLO(void *tPtr,const int64_t localSocket,const InetAddress &atAddress,int64_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->planetWorldId());
outp.append((uint64_t)RR->topology->planetWorldTimestamp());
const unsigned int startCryptedPortionAt = outp.size();
std::vector<World> moons(RR->topology->moons());
std::vector<uint64_t> moonsWanted(RR->topology->moonsWanted());
outp.append((uint16_t)(moons.size() + moonsWanted.size()));
for(std::vector<World>::const_iterator m(moons.begin());m!=moons.end();++m) {
outp.append((uint8_t)m->type());
outp.append((uint64_t)m->id());
outp.append((uint64_t)m->timestamp());
}
for(std::vector<uint64_t>::const_iterator m(moonsWanted.begin());m!=moonsWanted.end();++m) {
outp.append((uint8_t)World::TYPE_MOON);
outp.append(*m);
outp.append((uint64_t)0);
}
outp.cryptField(_key,startCryptedPortionAt,outp.size() - startCryptedPortionAt);
RR->node->expectReplyTo(outp.packetId());
if (atAddress) {
outp.armor(_key,false); // false == don't encrypt full payload, but add MAC
RR->node->putPacket(tPtr,localSocket,atAddress,outp.data(),outp.size());
} else {
RR->sw->send(tPtr,outp,false); // false == don't encrypt full payload, but add MAC
}
}
void Peer::attemptToContactAt(void *tPtr,const int64_t localSocket,const InetAddress &atAddress,int64_t now,bool sendFullHello)
{
if ( (!sendFullHello) && (_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(tPtr,localSocket,atAddress,outp.data(),outp.size());
} else {
sendHELLO(tPtr,localSocket,atAddress,now);
}
}
void Peer::tryMemorizedPath(void *tPtr,int64_t now)
{
if ((now - _lastTriedMemorizedPath) >= ZT_TRY_MEMORIZED_PATH_INTERVAL) {
_lastTriedMemorizedPath = now;
InetAddress mp;
if (RR->node->externalPathLookup(tPtr,_id.address(),-1,mp))
attemptToContactAt(tPtr,-1,mp,now,true);
}
}
unsigned int Peer::doPingAndKeepalive(void *tPtr,int64_t now)
{
unsigned int sent = 0;
Mutex::Lock _l(_paths_m);
const bool sendFullHello = ((now - _lastSentFullHello) >= ZT_PEER_PING_PERIOD);
_lastSentFullHello = now;
// Right now we only keep pinging links that have the maximum priority. The
// priority is used to track cluster redirections, meaning that when a cluster
// redirects us its redirect target links override all other links and we
// let those old links expire.
long maxPriority = 0;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p)
maxPriority = std::max(_paths[i].priority,maxPriority);
else break;
}
unsigned int j = 0;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
// Clean expired and reduced priority paths
if ( ((now - _paths[i].lr) < ZT_PEER_PATH_EXPIRATION) && (_paths[i].priority == maxPriority) ) {
if ((sendFullHello)||(_paths[i].p->needsHeartbeat(now))) {
attemptToContactAt(tPtr,_paths[i].p->localSocket(),_paths[i].p->address(),now,sendFullHello);
_paths[i].p->sent(now);
sent |= (_paths[i].p->address().ss_family == AF_INET) ? 0x1 : 0x2;
}
if (i != j)
_paths[j] = _paths[i];
++j;
}
} else break;
}
while(j < ZT_MAX_PEER_NETWORK_PATHS) {
_paths[j].lr = 0;
_paths[j].p.zero();
_paths[j].priority = 1;
++j;
}
return sent;
}
void Peer::clusterRedirect(void *tPtr,const SharedPtr<Path> &originatingPath,const InetAddress &remoteAddress,const int64_t now)
{
SharedPtr<Path> np(RR->topology->getPath(originatingPath->localSocket(),remoteAddress));
RR->t->peerRedirected(tPtr,0,*this,np);
attemptToContactAt(tPtr,originatingPath->localSocket(),remoteAddress,now,true);
{
Mutex::Lock _l(_paths_m);
// New priority is higher than the priority of the originating path (if known)
long newPriority = 1;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if (_paths[i].p == originatingPath) {
newPriority = _paths[i].priority;
break;
}
} else break;
}
newPriority += 2;
// Erase any paths with lower priority than this one or that are duplicate
// IPs and add this path.
unsigned int j = 0;
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if ((_paths[i].priority >= newPriority)&&(!_paths[i].p->address().ipsEqual2(remoteAddress))) {
if (i != j)
_paths[j] = _paths[i];
++j;
}
}
}
if (j < ZT_MAX_PEER_NETWORK_PATHS) {
_paths[j].lr = now;
_paths[j].p = np;
_paths[j].priority = newPriority;
++j;
while (j < ZT_MAX_PEER_NETWORK_PATHS) {
_paths[j].lr = 0;
_paths[j].p.zero();
_paths[j].priority = 1;
++j;
}
}
}
}
void Peer::resetWithinScope(void *tPtr,InetAddress::IpScope scope,int inetAddressFamily,int64_t now)
{
Mutex::Lock _l(_paths_m);
for(unsigned int i=0;i<ZT_MAX_PEER_NETWORK_PATHS;++i) {
if (_paths[i].p) {
if ((_paths[i].p->address().ss_family == inetAddressFamily)&&(_paths[i].p->ipScope() == scope)) {
attemptToContactAt(tPtr,_paths[i].p->localSocket(),_paths[i].p->address(),now,false);
_paths[i].p->sent(now);
_paths[i].lr = 0; // path will not be used unless it speaks again
}
} else break;
}
}
} // namespace ZeroTier
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