mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-28 00:38:51 +00:00
2c995f1f91
implementing NAT, do implement stateful firewalling with absurdly short timeouts (<60s). Keepalives are still required in IPv6. Network engineers continue to mindlessly carry forward cruft and baggage from IPv4 to IPv6.
366 lines
11 KiB
C++
366 lines
11 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_PATH_HPP
|
|
#define ZT_PATH_HPP
|
|
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
|
|
#include <stdexcept>
|
|
#include <algorithm>
|
|
|
|
#include "Constants.hpp"
|
|
#include "InetAddress.hpp"
|
|
|
|
// Note: if you change these flags check the logic below. Some of it depends
|
|
// on these bits being what they are.
|
|
|
|
/**
|
|
* Flag indicating that this path is suboptimal
|
|
*
|
|
* Clusters set this flag on remote paths if GeoIP or other routing decisions
|
|
* indicate that a peer should be handed off to another cluster member.
|
|
*/
|
|
#define ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL 0x0001
|
|
|
|
/**
|
|
* Flag indicating that this path is optimal
|
|
*
|
|
* Peers set this flag on paths that are pushed by a cluster and indicated as
|
|
* optimal. A second flag is needed since we want to prioritize cluster optimal
|
|
* paths and de-prioritize sub-optimal paths and for new paths we don't know
|
|
* which one they are. So we want a trinary state: optimal, suboptimal, unknown.
|
|
*/
|
|
#define ZT_PATH_FLAG_CLUSTER_OPTIMAL 0x0002
|
|
|
|
/**
|
|
* Maximum return value of preferenceRank()
|
|
*/
|
|
#define ZT_PATH_MAX_PREFERENCE_RANK ((ZT_INETADDRESS_MAX_SCOPE << 1) | 1)
|
|
|
|
namespace ZeroTier {
|
|
|
|
class RuntimeEnvironment;
|
|
|
|
/**
|
|
* Base class for paths
|
|
*
|
|
* The base Path class is an immutable value.
|
|
*/
|
|
class Path
|
|
{
|
|
public:
|
|
Path() :
|
|
_lastSend(0),
|
|
_lastPing(0),
|
|
_lastKeepalive(0),
|
|
_lastReceived(0),
|
|
_addr(),
|
|
_localAddress(),
|
|
_flags(0),
|
|
_ipScope(InetAddress::IP_SCOPE_NONE)
|
|
{
|
|
}
|
|
|
|
Path(const InetAddress &localAddress,const InetAddress &addr) :
|
|
_lastSend(0),
|
|
_lastPing(0),
|
|
_lastKeepalive(0),
|
|
_lastReceived(0),
|
|
_addr(addr),
|
|
_localAddress(localAddress),
|
|
_flags(0),
|
|
_ipScope(addr.ipScope())
|
|
{
|
|
}
|
|
|
|
inline Path &operator=(const Path &p)
|
|
{
|
|
if (this != &p)
|
|
memcpy(this,&p,sizeof(Path));
|
|
return *this;
|
|
}
|
|
|
|
/**
|
|
* Called when a packet is sent to this remote path
|
|
*
|
|
* This is called automatically by Path::send().
|
|
*
|
|
* @param t Time of send
|
|
*/
|
|
inline void sent(uint64_t t) { _lastSend = t; }
|
|
|
|
/**
|
|
* Called when we've sent a ping or echo
|
|
*
|
|
* @param t Time of send
|
|
*/
|
|
inline void pinged(uint64_t t) { _lastPing = t; }
|
|
|
|
/**
|
|
* Called when we send a NAT keepalive
|
|
*
|
|
* @param t Time of send
|
|
*/
|
|
inline void sentKeepalive(uint64_t t) { _lastKeepalive = t; }
|
|
|
|
/**
|
|
* Called when a packet is received from this remote path
|
|
*
|
|
* @param t Time of receive
|
|
*/
|
|
inline void received(uint64_t t)
|
|
{
|
|
_lastReceived = t;
|
|
_probation = 0;
|
|
}
|
|
|
|
/**
|
|
* @param now Current time
|
|
* @return True if this path appears active
|
|
*/
|
|
inline bool active(uint64_t now) const
|
|
{
|
|
return ( ((now - _lastReceived) < ZT_PATH_ACTIVITY_TIMEOUT) && (_probation < ZT_PEER_DEAD_PATH_DETECTION_MAX_PROBATION) );
|
|
}
|
|
|
|
/**
|
|
* Send a packet via this path
|
|
*
|
|
* @param RR Runtime environment
|
|
* @param data Packet data
|
|
* @param len Packet length
|
|
* @param now Current time
|
|
* @return True if transport reported success
|
|
*/
|
|
bool send(const RuntimeEnvironment *RR,const void *data,unsigned int len,uint64_t now);
|
|
|
|
/**
|
|
* @return Address of local side of this path or NULL if unspecified
|
|
*/
|
|
inline const InetAddress &localAddress() const throw() { return _localAddress; }
|
|
|
|
/**
|
|
* @return Time of last send to this path
|
|
*/
|
|
inline uint64_t lastSend() const throw() { return _lastSend; }
|
|
|
|
/**
|
|
* @return Time we last pinged or dead path checked this link
|
|
*/
|
|
inline uint64_t lastPing() const throw() { return _lastPing; }
|
|
|
|
/**
|
|
* @return Time of last keepalive
|
|
*/
|
|
inline uint64_t lastKeepalive() const throw() { return _lastKeepalive; }
|
|
|
|
/**
|
|
* @return Time of last receive from this path
|
|
*/
|
|
inline uint64_t lastReceived() const throw() { return _lastReceived; }
|
|
|
|
/**
|
|
* @return Physical address
|
|
*/
|
|
inline const InetAddress &address() const throw() { return _addr; }
|
|
|
|
/**
|
|
* @return IP scope -- faster shortcut for address().ipScope()
|
|
*/
|
|
inline InetAddress::IpScope ipScope() const throw() { return _ipScope; }
|
|
|
|
/**
|
|
* @param f Valuve of ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL and inverse of ZT_PATH_FLAG_CLUSTER_OPTIMAL (both are changed)
|
|
*/
|
|
inline void setClusterSuboptimal(bool f)
|
|
{
|
|
if (f) {
|
|
_flags = (_flags | ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL) & ~ZT_PATH_FLAG_CLUSTER_OPTIMAL;
|
|
} else {
|
|
_flags = (_flags | ZT_PATH_FLAG_CLUSTER_OPTIMAL) & ~ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @return True if ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL is set
|
|
*/
|
|
inline bool isClusterSuboptimal() const { return ((_flags & ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL) != 0); }
|
|
|
|
/**
|
|
* @return True if ZT_PATH_FLAG_CLUSTER_OPTIMAL is set
|
|
*/
|
|
inline bool isClusterOptimal() const { return ((_flags & ZT_PATH_FLAG_CLUSTER_OPTIMAL) != 0); }
|
|
|
|
/**
|
|
* @return Preference rank, higher == better (will be less than 255)
|
|
*/
|
|
inline unsigned int preferenceRank() const throw()
|
|
{
|
|
/* First, since the scope enum values in InetAddress.hpp are in order of
|
|
* use preference rank, we take that. Then we multiple by two, yielding
|
|
* a sequence like 0, 2, 4, 6, etc. Then if it's IPv6 we add one. This
|
|
* makes IPv6 addresses of a given scope outrank IPv4 addresses of the
|
|
* same scope -- e.g. 1 outranks 0. This makes us prefer IPv6, but not
|
|
* if the address scope/class is of a fundamentally lower rank. */
|
|
return ( ((unsigned int)_ipScope << 1) | (unsigned int)(_addr.ss_family == AF_INET6) );
|
|
}
|
|
|
|
/**
|
|
* @return This path's overall quality score (higher is better)
|
|
*/
|
|
inline uint64_t score() const throw()
|
|
{
|
|
// This is a little bit convoluted because we try to be branch-free, using multiplication instead of branches for boolean flags
|
|
|
|
// Start with the last time this path was active, and add a fudge factor to prevent integer underflow if _lastReceived is 0
|
|
uint64_t score = _lastReceived + (ZT_PEER_DIRECT_PING_DELAY * (ZT_PEER_DEAD_PATH_DETECTION_MAX_PROBATION + 1));
|
|
|
|
// Increase score based on path preference rank, which is based on IP scope and address family
|
|
score += preferenceRank() * (ZT_PEER_DIRECT_PING_DELAY / ZT_PATH_MAX_PREFERENCE_RANK);
|
|
|
|
// Increase score if this is known to be an optimal path to a cluster
|
|
score += (uint64_t)(_flags & ZT_PATH_FLAG_CLUSTER_OPTIMAL) * (ZT_PEER_DIRECT_PING_DELAY / 2); // /2 because CLUSTER_OPTIMAL is flag 0x0002
|
|
|
|
// Decrease score if this is known to be a sub-optimal path to a cluster
|
|
score -= (uint64_t)(_flags & ZT_PATH_FLAG_CLUSTER_SUBOPTIMAL) * ZT_PEER_DIRECT_PING_DELAY;
|
|
|
|
// Penalize for missed ECHO tests in dead path detection
|
|
score -= (uint64_t)((ZT_PEER_DIRECT_PING_DELAY / 2) * _probation);
|
|
|
|
return score;
|
|
}
|
|
|
|
/**
|
|
* @return True if path is considered reliable (no NAT keepalives etc. are needed)
|
|
*/
|
|
inline bool reliable() const throw()
|
|
{
|
|
if ((_addr.ss_family == AF_INET)||(_addr.ss_family == AF_INET6))
|
|
return ((_ipScope != InetAddress::IP_SCOPE_GLOBAL)&&(_ipScope != InetAddress::IP_SCOPE_PSEUDOPRIVATE));
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* @return True if address is non-NULL
|
|
*/
|
|
inline operator bool() const throw() { return (_addr); }
|
|
|
|
/**
|
|
* Check whether this address is valid for a ZeroTier path
|
|
*
|
|
* This checks the address type and scope against address types and scopes
|
|
* that we currently support for ZeroTier communication.
|
|
*
|
|
* @param a Address to check
|
|
* @return True if address is good for ZeroTier path use
|
|
*/
|
|
static inline bool isAddressValidForPath(const InetAddress &a)
|
|
throw()
|
|
{
|
|
if ((a.ss_family == AF_INET)||(a.ss_family == AF_INET6)) {
|
|
switch(a.ipScope()) {
|
|
/* Note: we don't do link-local at the moment. Unfortunately these
|
|
* cause several issues. The first is that they usually require a
|
|
* device qualifier, which we don't handle yet and can't portably
|
|
* push in PUSH_DIRECT_PATHS. The second is that some OSes assign
|
|
* these very ephemerally or otherwise strangely. So we'll use
|
|
* private, pseudo-private, shared (e.g. carrier grade NAT), or
|
|
* global IP addresses. */
|
|
case InetAddress::IP_SCOPE_PRIVATE:
|
|
case InetAddress::IP_SCOPE_PSEUDOPRIVATE:
|
|
case InetAddress::IP_SCOPE_SHARED:
|
|
case InetAddress::IP_SCOPE_GLOBAL:
|
|
if (a.ss_family == AF_INET6) {
|
|
// TEMPORARY HACK: for now, we are going to blacklist he.net IPv6
|
|
// tunnels due to very spotty performance and low MTU issues over
|
|
// these IPv6 tunnel links.
|
|
const uint8_t *ipd = reinterpret_cast<const uint8_t *>(reinterpret_cast<const struct sockaddr_in6 *>(&a)->sin6_addr.s6_addr);
|
|
if ((ipd[0] == 0x20)&&(ipd[1] == 0x01)&&(ipd[2] == 0x04)&&(ipd[3] == 0x70))
|
|
return false;
|
|
}
|
|
return true;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* @return Current path probation count (for dead path detect)
|
|
*/
|
|
inline unsigned int probation() const { return _probation; }
|
|
|
|
/**
|
|
* Increase this path's probation violation count (for dead path detect)
|
|
*/
|
|
inline void increaseProbation() { ++_probation; }
|
|
|
|
template<unsigned int C>
|
|
inline void serialize(Buffer<C> &b) const
|
|
{
|
|
b.append((uint8_t)2); // version
|
|
b.append((uint64_t)_lastSend);
|
|
b.append((uint64_t)_lastPing);
|
|
b.append((uint64_t)_lastKeepalive);
|
|
b.append((uint64_t)_lastReceived);
|
|
_addr.serialize(b);
|
|
_localAddress.serialize(b);
|
|
b.append((uint16_t)_flags);
|
|
b.append((uint16_t)_probation);
|
|
}
|
|
|
|
template<unsigned int C>
|
|
inline unsigned int deserialize(const Buffer<C> &b,unsigned int startAt = 0)
|
|
{
|
|
unsigned int p = startAt;
|
|
if (b[p++] != 2)
|
|
throw std::invalid_argument("invalid serialized Path");
|
|
_lastSend = b.template at<uint64_t>(p); p += 8;
|
|
_lastPing = b.template at<uint64_t>(p); p += 8;
|
|
_lastKeepalive = b.template at<uint64_t>(p); p += 8;
|
|
_lastReceived = b.template at<uint64_t>(p); p += 8;
|
|
p += _addr.deserialize(b,p);
|
|
p += _localAddress.deserialize(b,p);
|
|
_flags = b.template at<uint16_t>(p); p += 2;
|
|
_probation = b.template at<uint16_t>(p); p += 2;
|
|
_ipScope = _addr.ipScope();
|
|
return (p - startAt);
|
|
}
|
|
|
|
inline bool operator==(const Path &p) const { return ((p._addr == _addr)&&(p._localAddress == _localAddress)); }
|
|
inline bool operator!=(const Path &p) const { return ((p._addr != _addr)||(p._localAddress != _localAddress)); }
|
|
|
|
private:
|
|
uint64_t _lastSend;
|
|
uint64_t _lastPing;
|
|
uint64_t _lastKeepalive;
|
|
uint64_t _lastReceived;
|
|
InetAddress _addr;
|
|
InetAddress _localAddress;
|
|
unsigned int _flags;
|
|
unsigned int _probation;
|
|
InetAddress::IpScope _ipScope; // memoize this since it's a computed value checked often
|
|
};
|
|
|
|
} // namespace ZeroTier
|
|
|
|
#endif
|