ZeroTierOne/node/Peer.hpp

439 lines
13 KiB
C++

/*
* 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/>.
*/
#ifndef ZT_PEER_HPP
#define ZT_PEER_HPP
#include <stdint.h>
#include "Constants.hpp"
#include <algorithm>
#include <utility>
#include <vector>
#include <stdexcept>
#include "../include/ZeroTierOne.h"
#include "RuntimeEnvironment.hpp"
#include "Path.hpp"
#include "Address.hpp"
#include "Utils.hpp"
#include "Identity.hpp"
#include "InetAddress.hpp"
#include "Packet.hpp"
#include "SharedPtr.hpp"
#include "AtomicCounter.hpp"
#include "Hashtable.hpp"
#include "Mutex.hpp"
#include "NonCopyable.hpp"
namespace ZeroTier {
/**
* Peer on P2P Network (virtual layer 1)
*/
class Peer : NonCopyable
{
friend class SharedPtr<Peer>;
private:
Peer() {} // disabled to prevent bugs -- should not be constructed uninitialized
public:
~Peer() { Utils::burn(_key,sizeof(_key)); }
/**
* Construct a new peer
*
* @param renv Runtime environment
* @param myIdentity Identity of THIS node (for key agreement)
* @param peerIdentity Identity of peer
* @throws std::runtime_error Key agreement with peer's identity failed
*/
Peer(const RuntimeEnvironment *renv,const Identity &myIdentity,const Identity &peerIdentity);
/**
* @return Time peer record was last used in any way
*/
inline uint64_t lastUsed() const throw() { return _lastUsed; }
/**
* Log a use of this peer record (done by Topology when peers are looked up)
*
* @param now New time of last use
*/
inline void use(uint64_t now) throw() { _lastUsed = now; }
/**
* @return This peer's ZT address (short for identity().address())
*/
inline const Address &address() const throw() { return _id.address(); }
/**
* @return This peer's identity
*/
inline const Identity &identity() const throw() { return _id; }
/**
* Log receipt of an authenticated packet
*
* This is called by the decode pipe when a packet is proven to be authentic
* and appears to be valid.
*
* @param RR Runtime environment
* @param localAddr Local address
* @param remoteAddr Internet address of sender
* @param hops ZeroTier (not IP) hops
* @param packetId Packet ID
* @param verb Packet verb
* @param inRePacketId Packet ID in reply to (default: none)
* @param inReVerb Verb in reply to (for OK/ERROR, default: VERB_NOP)
* @param trustEstablished If true, some form of non-trivial trust (like allowed in network) has been established
*/
void received(
const InetAddress &localAddr,
const InetAddress &remoteAddr,
unsigned int hops,
uint64_t packetId,
Packet::Verb verb,
uint64_t inRePacketId,
Packet::Verb inReVerb,
const bool trustEstablished);
/**
* Get the current best direct path to this peer
*
* @param now Current time
* @return Best path or NULL if there are no active direct paths
*/
inline Path *getBestPath(uint64_t now) { return _getBestPath(now); }
/**
* @param now Current time
* @param addr Remote address
* @return True if we have an active path to this destination
*/
inline bool hasActivePathTo(uint64_t now,const InetAddress &addr) const
{
for(unsigned int p=0;p<_numPaths;++p) {
if ((_paths[p].active(now))&&(_paths[p].address() == addr))
return true;
}
return false;
}
/**
* Set all paths in the same ss_family that are not this one to cluster suboptimal
*
* Addresses in other families are not affected.
*
* @param addr Address to make exclusive
*/
inline void setClusterOptimalPathForAddressFamily(const InetAddress &addr)
{
for(unsigned int p=0;p<_numPaths;++p) {
if (_paths[p].address().ss_family == addr.ss_family) {
_paths[p].setClusterSuboptimal(_paths[p].address() != addr);
}
}
}
/**
* Send via best path
*
* @param data Packet data
* @param len Packet length
* @param now Current time
* @return Path used on success or NULL on failure
*/
inline Path *send(const void *data,unsigned int len,uint64_t now)
{
Path *const bestPath = getBestPath(now);
if (bestPath) {
if (bestPath->send(RR,data,len,now))
return bestPath;
}
return (Path *)0;
}
/**
* Send a HELLO to this peer at a specified physical address
*
* This does not update any statistics. It's used to send initial HELLOs
* for NAT traversal and path verification.
*
* @param localAddr Local address
* @param atAddress Destination address
* @param now Current time
* @param ttl Desired IP TTL (default: 0 to leave alone)
*/
void sendHELLO(const InetAddress &localAddr,const InetAddress &atAddress,uint64_t now,unsigned int ttl = 0);
/**
* Send pings or keepalives depending on configured timeouts
*
* @param now Current time
* @param inetAddressFamily Keep this address family alive, or 0 to simply pick current best ignoring family
* @return True if at least one direct path seems alive
*/
bool doPingAndKeepalive(uint64_t now,int inetAddressFamily);
/**
* @return All known direct paths to this peer (active or inactive)
*/
inline std::vector<Path> paths() const
{
std::vector<Path> pp;
for(unsigned int p=0,np=_numPaths;p<np;++p)
pp.push_back(_paths[p]);
return pp;
}
/**
* @return Time of last receive of anything, whether direct or relayed
*/
inline uint64_t lastReceive() const throw() { return _lastReceive; }
/**
* @return Time of most recent unicast frame received
*/
inline uint64_t lastUnicastFrame() const throw() { return _lastUnicastFrame; }
/**
* @return Time of most recent multicast frame received
*/
inline uint64_t lastMulticastFrame() const throw() { return _lastMulticastFrame; }
/**
* @return Time of most recent frame of any kind (unicast or multicast)
*/
inline uint64_t lastFrame() const throw() { return std::max(_lastUnicastFrame,_lastMulticastFrame); }
/**
* @return True if this peer has sent us real network traffic recently
*/
inline uint64_t activelyTransferringFrames(uint64_t now) const throw() { return ((now - lastFrame()) < ZT_PEER_ACTIVITY_TIMEOUT); }
/**
* @return Latency in milliseconds or 0 if unknown
*/
inline unsigned int latency() const { return _latency; }
/**
* This computes a quality score for relays and root servers
*
* If we haven't heard anything from these in ZT_PEER_ACTIVITY_TIMEOUT, they
* receive the worst possible quality (max unsigned int). Otherwise the
* quality is a product of latency and the number of potential missed
* pings. This causes roots and relays to switch over a bit faster if they
* fail.
*
* @return Relay quality score computed from latency and other factors, lower is better
*/
inline unsigned int relayQuality(const uint64_t now) const
{
const uint64_t tsr = now - _lastReceive;
if (tsr >= ZT_PEER_ACTIVITY_TIMEOUT)
return (~(unsigned int)0);
unsigned int l = _latency;
if (!l)
l = 0xffff;
return (l * (((unsigned int)tsr / (ZT_PEER_DIRECT_PING_DELAY + 1000)) + 1));
}
/**
* Update latency with a new direct measurment
*
* @param l Direct latency measurment in ms
*/
inline void addDirectLatencyMeasurment(unsigned int l)
{
unsigned int ol = _latency;
if ((ol > 0)&&(ol < 10000))
_latency = (ol + std::min(l,(unsigned int)65535)) / 2;
else _latency = std::min(l,(unsigned int)65535);
}
/**
* @param now Current time
* @return True if this peer has at least one active direct path
*/
inline bool hasActiveDirectPath(uint64_t now) const
{
for(unsigned int p=0;p<_numPaths;++p) {
if (_paths[p].active(now))
return true;
}
return false;
}
#ifdef ZT_ENABLE_CLUSTER
/**
* @param now Current time
* @return True if this peer has at least one active direct path that is not cluster-suboptimal
*/
inline bool hasClusterOptimalPath(uint64_t now) const
{
for(unsigned int p=0,np=_numPaths;p<np;++p) {
if ((_paths[p].active(now))&&(!_paths[p].isClusterSuboptimal()))
return true;
}
return false;
}
#endif
/**
* Reset paths within a given scope
*
* @param scope IP scope of paths to reset
* @param now Current time
* @return True if at least one path was forgotten
*/
bool resetWithinScope(InetAddress::IpScope scope,uint64_t now);
/**
* @return 256-bit secret symmetric encryption key
*/
inline const unsigned char *key() const throw() { return _key; }
/**
* Set the currently known remote version of this peer's client
*
* @param vproto Protocol version
* @param vmaj Major version
* @param vmin Minor version
* @param vrev Revision
*/
inline void setRemoteVersion(unsigned int vproto,unsigned int vmaj,unsigned int vmin,unsigned int vrev)
{
_vProto = (uint16_t)vproto;
_vMajor = (uint16_t)vmaj;
_vMinor = (uint16_t)vmin;
_vRevision = (uint16_t)vrev;
}
inline unsigned int remoteVersionProtocol() const throw() { return _vProto; }
inline unsigned int remoteVersionMajor() const throw() { return _vMajor; }
inline unsigned int remoteVersionMinor() const throw() { return _vMinor; }
inline unsigned int remoteVersionRevision() const throw() { return _vRevision; }
inline bool remoteVersionKnown() const throw() { return ((_vMajor > 0)||(_vMinor > 0)||(_vRevision > 0)); }
/**
* Get most recently active path addresses for IPv4 and/or IPv6
*
* Note that v4 and v6 are not modified if they are not found, so
* initialize these to a NULL address to be able to check.
*
* @param now Current time
* @param v4 Result parameter to receive active IPv4 address, if any
* @param v6 Result parameter to receive active IPv6 address, if any
*/
void getBestActiveAddresses(uint64_t now,InetAddress &v4,InetAddress &v6) const;
/**
* Perform periodic cleaning operations
*
* @param now Current time
*/
void clean(uint64_t now);
/**
* Update direct path push stats and return true if we should respond
*
* This is a circuit breaker to make VERB_PUSH_DIRECT_PATHS not particularly
* useful as a DDOS amplification attack vector. Otherwise a malicious peer
* could send loads of these and cause others to bombard arbitrary IPs with
* traffic.
*
* @param now Current time
* @return True if we should respond
*/
inline bool shouldRespondToDirectPathPush(const uint64_t now)
{
if ((now - _lastDirectPathPushReceive) <= ZT_PUSH_DIRECT_PATHS_CUTOFF_TIME)
++_directPathPushCutoffCount;
else _directPathPushCutoffCount = 0;
_lastDirectPathPushReceive = now;
return (_directPathPushCutoffCount < ZT_PUSH_DIRECT_PATHS_CUTOFF_LIMIT);
}
/**
* Find a common set of addresses by which two peers can link, if any
*
* @param a Peer A
* @param b Peer B
* @param now Current time
* @return Pair: B's address (to send to A), A's address (to send to B)
*/
static inline std::pair<InetAddress,InetAddress> findCommonGround(const Peer &a,const Peer &b,uint64_t now)
{
std::pair<InetAddress,InetAddress> v4,v6;
b.getBestActiveAddresses(now,v4.first,v6.first);
a.getBestActiveAddresses(now,v4.second,v6.second);
if ((v6.first)&&(v6.second)) // prefer IPv6 if both have it since NAT-t is (almost) unnecessary
return v6;
else if ((v4.first)&&(v4.second))
return v4;
else return std::pair<InetAddress,InetAddress>();
}
private:
void _doDeadPathDetection(Path &p,const uint64_t now);
Path *_getBestPath(const uint64_t now);
Path *_getBestPath(const uint64_t now,int inetAddressFamily);
bool _pushDirectPaths(const InetAddress &localAddr,const InetAddress &toAddress,uint64_t now);
unsigned char _key[ZT_PEER_SECRET_KEY_LENGTH];
const RuntimeEnvironment *RR;
uint64_t _lastUsed;
uint64_t _lastReceive; // direct or indirect
uint64_t _lastUnicastFrame;
uint64_t _lastMulticastFrame;
uint64_t _lastAnnouncedTo;
uint64_t _lastDirectPathPushSent;
uint64_t _lastDirectPathPushReceive;
uint64_t _lastPathSort;
uint16_t _vProto;
uint16_t _vMajor;
uint16_t _vMinor;
uint16_t _vRevision;
Identity _id;
Path _paths[ZT_MAX_PEER_NETWORK_PATHS];
unsigned int _numPaths;
unsigned int _latency;
unsigned int _directPathPushCutoffCount;
AtomicCounter __refCount;
};
} // namespace ZeroTier
// Add a swap() for shared ptr's to peers to speed up peer sorts
namespace std {
template<>
inline void swap(ZeroTier::SharedPtr<ZeroTier::Peer> &a,ZeroTier::SharedPtr<ZeroTier::Peer> &b)
{
a.swap(b);
}
}
#endif