/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2015 ZeroTier, Inc.
*
* 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/>.
*
* --
*
* ZeroTier may be used and distributed under the terms of the GPLv3, which
* are available at: http://www.gnu.org/licenses/gpl-3.0.html
*
* If you would like to embed ZeroTier into a commercial application or
* redistribute it in a modified binary form, please contact ZeroTier Networks
* LLC. Start here: http://www.zerotier.com/
*/
#include "../version.h"
#include "Constants.hpp"
#include "Peer.hpp"
#include "Node.hpp"
#include "Switch.hpp"
#include "Network.hpp"
#include "AntiRecursion.hpp"
#include "SelfAwareness.hpp"
#include "Cluster.hpp"
#include <algorithm>
#define ZT_PEER_PATH_SORT_INTERVAL 5000
namespace ZeroTier {
// Used to send varying values for NAT keepalive
static uint32_t _natKeepaliveBuf = 0;
Peer::Peer(const Identity &myIdentity,const Identity &peerIdentity)
throw(std::runtime_error) :
_lastUsed(0),
_lastReceive(0),
_lastUnicastFrame(0),
_lastMulticastFrame(0),
_lastAnnouncedTo(0),
_lastPathConfirmationSent(0),
_lastDirectPathPushSent(0),
_lastDirectPathPushReceived(0),
_lastPathSort(0),
_vProto(0),
_vMajor(0),
_vMinor(0),
_vRevision(0),
_id(peerIdentity),
_numPaths(0),
_latency(0),
_networkComs(4),
_lastPushedComs(4)
{
if (!myIdentity.agree(peerIdentity,_key,ZT_PEER_SECRET_KEY_LENGTH))
throw std::runtime_error("new peer identity key agreement failed");
}
void Peer::received(
const RuntimeEnvironment *RR,
const InetAddress &localAddr,
const InetAddress &remoteAddr,
unsigned int hops,
uint64_t packetId,
Packet::Verb verb,
uint64_t inRePacketId,
Packet::Verb inReVerb)
{
const uint64_t now = RR->node->now();
bool needMulticastGroupAnnounce = false;
{
Mutex::Lock _l(_lock);
_lastReceive = now;
if (!hops) {
bool pathIsConfirmed = false;
/* Learn new paths from direct (hops == 0) packets */
{
unsigned int np = _numPaths;
for(unsigned int p=0;p<np;++p) {
if ((_paths[p].address() == remoteAddr)&&(_paths[p].localAddress() == localAddr)) {
_paths[p].received(now);
pathIsConfirmed = true;
break;
}
}
if (!pathIsConfirmed) {
if ((verb == Packet::VERB_OK)&&((inReVerb == Packet::VERB_HELLO)||(inReVerb == Packet::VERB_ECHO))) {
// Learn paths if they've been confirmed via a HELLO or an ECHO
RemotePath *slot = (RemotePath *)0;
if (np < ZT_MAX_PEER_NETWORK_PATHS) {
slot = &(_paths[np++]);
} else {
uint64_t slotLRmin = 0xffffffffffffffffULL;
for(unsigned int p=0;p<ZT_MAX_PEER_NETWORK_PATHS;++p) {
if (_paths[p].lastReceived() <= slotLRmin) {
slotLRmin = _paths[p].lastReceived();
slot = &(_paths[p]);
}
}
}
if (slot) {
*slot = RemotePath(localAddr,remoteAddr);
slot->received(now);
_numPaths = np;
pathIsConfirmed = true;
_sortPaths(now);
}
} else {
/* If this path is not known, send a HELLO. We don't learn
* paths without confirming that a bidirectional link is in
* fact present, but any packet that decodes and authenticates
* correctly is considered valid. */
if ((now - _lastPathConfirmationSent) >= ZT_MIN_PATH_CONFIRMATION_INTERVAL) {
_lastPathConfirmationSent = now;
TRACE("got %s via unknown path %s(%s), confirming...",Packet::verbString(verb),_id.address().toString().c_str(),remoteAddr.toString().c_str());
attemptToContactAt(RR,localAddr,remoteAddr,now);
}
}
}
}
#ifdef ZT_ENABLE_CLUSTER
if ((pathIsConfirmed)&&(RR->cluster))
RR->cluster->replicateHavePeer(_id);
#endif
}
if ((now - _lastAnnouncedTo) >= ((ZT_MULTICAST_LIKE_EXPIRE / 2) - 1000)) {
_lastAnnouncedTo = now;
needMulticastGroupAnnounce = true;
}
if ((verb == Packet::VERB_FRAME)||(verb == Packet::VERB_EXT_FRAME))
_lastUnicastFrame = now;
else if (verb == Packet::VERB_MULTICAST_FRAME)
_lastMulticastFrame = now;
}
if (needMulticastGroupAnnounce) {
const std::vector< SharedPtr<Network> > networks(RR->node->allNetworks());
for(std::vector< SharedPtr<Network> >::const_iterator n(networks.begin());n!=networks.end();++n)
(*n)->tryAnnounceMulticastGroupsTo(SharedPtr<Peer>(this));
}
}
void Peer::attemptToContactAt(const RuntimeEnvironment *RR,const InetAddress &localAddr,const InetAddress &atAddress,uint64_t now)
{
// _lock not required here since _id is immutable and nothing else is accessed
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());
outp.armor(_key,false); // HELLO is sent in the clear
RR->antiRec->logOutgoingZT(outp.data(),outp.size());
RR->node->putPacket(localAddr,atAddress,outp.data(),outp.size());
}
bool Peer::doPingAndKeepalive(const RuntimeEnvironment *RR,uint64_t now,int inetAddressFamily)
{
RemotePath *p = (RemotePath *)0;
Mutex::Lock _l(_lock);
if (inetAddressFamily != 0) {
p = _getBestPath(now,inetAddressFamily);
} else {
p = _getBestPath(now);
}
if (p) {
if ((now - p->lastReceived()) >= ZT_PEER_DIRECT_PING_DELAY) {
TRACE("PING %s(%s) after %llums/%llums send/receive inactivity",_id.address().toString().c_str(),p->address().toString().c_str(),now - p->lastSend(),now - p->lastReceived());
attemptToContactAt(RR,p->localAddress(),p->address(),now);
p->sent(now);
} else if (((now - p->lastSend()) >= ZT_NAT_KEEPALIVE_DELAY)&&(!p->reliable())) {
TRACE("NAT keepalive %s(%s) after %llums/%llums send/receive inactivity",_id.address().toString().c_str(),p->address().toString().c_str(),now - p->lastSend(),now - p->lastReceived());
_natKeepaliveBuf += (uint32_t)((now * 0x9e3779b1) >> 1); // tumble this around to send constantly varying (meaningless) payloads
RR->node->putPacket(p->localAddress(),p->address(),&_natKeepaliveBuf,sizeof(_natKeepaliveBuf));
p->sent(now);
} else {
TRACE("no PING or NAT keepalive: addr==%s reliable==%d %llums/%llums send/receive inactivity",p->address().toString().c_str(),(int)p->reliable(),now - p->lastSend(),now - p->lastReceived());
}
return true;
}
return false;
}
void Peer::pushDirectPaths(const RuntimeEnvironment *RR,RemotePath *path,uint64_t now,bool force)
{
#ifdef ZT_ENABLE_CLUSTER
// Cluster mode disables normal PUSH_DIRECT_PATHS in favor of cluster-based peer redirection
if (RR->cluster)
return;
#endif
Mutex::Lock _l(_lock);
if (((now - _lastDirectPathPushSent) >= ZT_DIRECT_PATH_PUSH_INTERVAL)||(force)) {
_lastDirectPathPushSent = now;
std::vector<Path> dps(RR->node->directPaths());
if (dps.empty())
return;
#ifdef ZT_TRACE
{
std::string ps;
for(std::vector<Path>::const_iterator p(dps.begin());p!=dps.end();++p) {
if (ps.length() > 0)
ps.push_back(',');
ps.append(p->address().toString());
}
TRACE("pushing %u direct paths to %s: %s",(unsigned int)dps.size(),_id.address().toString().c_str(),ps.c_str());
}
#endif
std::vector<Path>::const_iterator p(dps.begin());
while (p != dps.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 != dps.end())&&((outp.size() + 24) < ZT_PROTO_MAX_PACKET_LENGTH)) {
uint8_t addressType = 4;
switch(p->address().ss_family) {
case AF_INET:
break;
case AF_INET6:
addressType = 6;
break;
default: // we currently only push IP addresses
++p;
continue;
}
uint8_t flags = 0;
switch(p->trust()) {
default:
break;
case Path::TRUST_PRIVACY:
flags |= 0x04; // no encryption
break;
case Path::TRUST_ULTIMATE:
flags |= (0x04 | 0x08); // no encryption, no authentication (redundant but go ahead and set both)
break;
}
outp.append(flags);
outp.append((uint16_t)0); // no extensions
outp.append(addressType);
outp.append((uint8_t)((addressType == 4) ? 6 : 18));
outp.append(p->address().rawIpData(),((addressType == 4) ? 4 : 16));
outp.append((uint16_t)p->address().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::resetWithinScope(const RuntimeEnvironment *RR,InetAddress::IpScope scope,uint64_t now)
{
Mutex::Lock _l(_lock);
unsigned int np = _numPaths;
unsigned int x = 0;
unsigned int y = 0;
while (x < np) {
if (_paths[x].address().ipScope() == scope) {
attemptToContactAt(RR,_paths[x].localAddress(),_paths[x].address(),now);
} else {
_paths[y++] = _paths[x];
}
++x;
}
_numPaths = y;
_sortPaths(now);
return (y < np);
}
void Peer::getBestActiveAddresses(uint64_t now,InetAddress &v4,InetAddress &v6) const
{
Mutex::Lock _l(_lock);
uint64_t bestV4 = 0,bestV6 = 0;
for(unsigned int p=0,np=_numPaths;p<np;++p) {
if (_paths[p].active(now)) {
uint64_t lr = _paths[p].lastReceived();
if (lr) {
if (_paths[p].address().isV4()) {
if (lr >= bestV4) {
bestV4 = lr;
v4 = _paths[p].address();
}
} else if (_paths[p].address().isV6()) {
if (lr >= bestV6) {
bestV6 = lr;
v6 = _paths[p].address();
}
}
}
}
}
}
bool Peer::networkMembershipCertificatesAgree(uint64_t nwid,const CertificateOfMembership &com) const
{
Mutex::Lock _l(_lock);
const _NetworkCom *ourCom = _networkComs.get(nwid);
if (ourCom)
return ourCom->com.agreesWith(com);
return false;
}
bool Peer::validateAndSetNetworkMembershipCertificate(const RuntimeEnvironment *RR,uint64_t nwid,const CertificateOfMembership &com)
{
// Sanity checks
if ((!com)||(com.issuedTo() != _id.address()))
return false;
// Return true if we already have this *exact* COM
{
Mutex::Lock _l(_lock);
_NetworkCom *ourCom = _networkComs.get(nwid);
if ((ourCom)&&(ourCom->com == com))
return true;
}
// Check signature, log and return if cert is invalid
if (com.signedBy() != Network::controllerFor(nwid)) {
TRACE("rejected network membership certificate for %.16llx signed by %s: signer not a controller of this network",(unsigned long long)_id,com.signedBy().toString().c_str());
return false; // invalid signer
}
if (com.signedBy() == RR->identity.address()) {
// We are the controller: RR->identity.address() == controller() == cert.signedBy()
// So, verify that we signed th cert ourself
if (!com.verify(RR->identity)) {
TRACE("rejected network membership certificate for %.16llx self signed by %s: signature check failed",(unsigned long long)_id,com.signedBy().toString().c_str());
return false; // invalid signature
}
} else {
SharedPtr<Peer> signer(RR->topology->getPeer(com.signedBy()));
if (!signer) {
// This would be rather odd, since this is our controller... could happen
// if we get packets before we've gotten config.
RR->sw->requestWhois(com.signedBy());
return false; // signer unknown
}
if (!com.verify(signer->identity())) {
TRACE("rejected network membership certificate for %.16llx signed by %s: signature check failed",(unsigned long long)_id,com.signedBy().toString().c_str());
return false; // invalid signature
}
}
// If we made it past all those checks, add or update cert in our cert info store
{
Mutex::Lock _l(_lock);
_networkComs.set(nwid,_NetworkCom(RR->node->now(),com));
}
return true;
}
bool Peer::needsOurNetworkMembershipCertificate(uint64_t nwid,uint64_t now,bool updateLastPushedTime)
{
Mutex::Lock _l(_lock);
uint64_t &lastPushed = _lastPushedComs[nwid];
const uint64_t tmp = lastPushed;
if (updateLastPushedTime)
lastPushed = now;
return ((now - tmp) >= (ZT_NETWORK_AUTOCONF_DELAY / 2));
}
void Peer::clean(const RuntimeEnvironment *RR,uint64_t now)
{
Mutex::Lock _l(_lock);
{
unsigned int np = _numPaths;
unsigned int x = 0;
unsigned int y = 0;
while (x < np) {
if (_paths[x].active(now))
_paths[y++] = _paths[x];
++x;
}
_numPaths = y;
}
{
uint64_t *k = (uint64_t *)0;
_NetworkCom *v = (_NetworkCom *)0;
Hashtable< uint64_t,_NetworkCom >::Iterator i(_networkComs);
while (i.next(k,v)) {
if ( (!RR->node->belongsToNetwork(*k)) && ((now - v->ts) >= ZT_PEER_NETWORK_COM_EXPIRATION) )
_networkComs.erase(*k);
}
}
{
uint64_t *k = (uint64_t *)0;
uint64_t *v = (uint64_t *)0;
Hashtable< uint64_t,uint64_t >::Iterator i(_lastPushedComs);
while (i.next(k,v)) {
if ((now - *v) > (ZT_NETWORK_AUTOCONF_DELAY * 2))
_lastPushedComs.erase(*k);
}
}
}
struct _SortPathsByQuality
{
uint64_t _now;
_SortPathsByQuality(const uint64_t now) : _now(now) {}
inline bool operator()(const RemotePath &a,const RemotePath &b) const
{
const uint64_t qa = (
((uint64_t)a.active(_now) << 63) |
(((uint64_t)(a.preferenceRank() & 0xfff)) << 51) |
((uint64_t)a.lastReceived() & 0x7ffffffffffffULL) );
const uint64_t qb = (
((uint64_t)b.active(_now) << 63) |
(((uint64_t)(b.preferenceRank() & 0xfff)) << 51) |
((uint64_t)b.lastReceived() & 0x7ffffffffffffULL) );
return (qb < qa); // invert sense to sort in descending order
}
};
void Peer::_sortPaths(const uint64_t now)
{
// assumes _lock is locked
_lastPathSort = now;
std::sort(&(_paths[0]),&(_paths[_numPaths]),_SortPathsByQuality(now));
}
RemotePath *Peer::_getBestPath(const uint64_t now)
{
// assumes _lock is locked
if ((now - _lastPathSort) >= ZT_PEER_PATH_SORT_INTERVAL)
_sortPaths(now);
if (_paths[0].active(now)) {
return &(_paths[0]);
} else {
_sortPaths(now);
if (_paths[0].active(now))
return &(_paths[0]);
}
return (RemotePath *)0;
}
RemotePath *Peer::_getBestPath(const uint64_t now,int inetAddressFamily)
{
// assumes _lock is locked
if ((now - _lastPathSort) >= ZT_PEER_PATH_SORT_INTERVAL)
_sortPaths(now);
for(int k=0;k<2;++k) { // try once, and if it fails sort and try one more time
for(unsigned int i=0;i<_numPaths;++i) {
if ((_paths[i].active(now))&&((int)_paths[i].address().ss_family == inetAddressFamily))
return &(_paths[i]);
}
_sortPaths(now);
}
return (RemotePath *)0;
}
} // namespace ZeroTier