ZeroTierOne/node/Path.hpp

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/*
* ZeroTier One - Network Virtualization Everywhere
2017-04-28 03:47:25 +00:00
* Copyright (C) 2011-2017 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/>.
2017-04-28 03:47:25 +00:00
*
* --
*
* 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.
*/
#ifndef ZT_PATH_HPP
#define ZT_PATH_HPP
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdexcept>
#include <algorithm>
#include "Constants.hpp"
#include "InetAddress.hpp"
#include "SharedPtr.hpp"
#include "AtomicCounter.hpp"
#include "NonCopyable.hpp"
#include "Utils.hpp"
/**
* Maximum return value of preferenceRank()
*/
#define ZT_PATH_MAX_PREFERENCE_RANK ((ZT_INETADDRESS_MAX_SCOPE << 1) | 1)
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/**
* Maximum distance for a path
*/
#define ZT_PATH_DISTANCE_MAX 0xffff
namespace ZeroTier {
class RuntimeEnvironment;
/**
* A path across the physical network
*/
class Path : NonCopyable
{
friend class SharedPtr<Path>;
public:
/**
* Efficient unique key for paths in a Hashtable
*/
class HashKey
{
public:
HashKey() {}
HashKey(const InetAddress &l,const InetAddress &r)
{
// This is an ad-hoc bit packing algorithm to yield unique keys for
// remote addresses and their local-side counterparts if defined.
// Portability across runtimes is not needed.
if (r.ss_family == AF_INET) {
_k[0] = (uint64_t)reinterpret_cast<const struct sockaddr_in *>(&r)->sin_addr.s_addr;
_k[1] = (uint64_t)reinterpret_cast<const struct sockaddr_in *>(&r)->sin_port;
if (l.ss_family == AF_INET) {
_k[2] = (uint64_t)reinterpret_cast<const struct sockaddr_in *>(&l)->sin_addr.s_addr;
_k[3] = (uint64_t)reinterpret_cast<const struct sockaddr_in *>(&r)->sin_port;
} else {
_k[2] = 0;
_k[3] = 0;
}
} else if (r.ss_family == AF_INET6) {
const uint8_t *a = reinterpret_cast<const uint8_t *>(reinterpret_cast<const struct sockaddr_in6 *>(&r)->sin6_addr.s6_addr);
uint8_t *b = reinterpret_cast<uint8_t *>(_k);
for(unsigned int i=0;i<16;++i) b[i] = a[i];
_k[2] = ~((uint64_t)reinterpret_cast<const struct sockaddr_in6 *>(&r)->sin6_port);
if (l.ss_family == AF_INET6) {
_k[2] ^= ((uint64_t)reinterpret_cast<const struct sockaddr_in6 *>(&r)->sin6_port) << 32;
a = reinterpret_cast<const uint8_t *>(reinterpret_cast<const struct sockaddr_in6 *>(&l)->sin6_addr.s6_addr);
b += 24;
for(unsigned int i=0;i<8;++i) b[i] = a[i];
a += 8;
for(unsigned int i=0;i<8;++i) b[i] ^= a[i];
}
} else {
_k[0] = 0;
_k[1] = 0;
_k[2] = 0;
_k[3] = 0;
}
}
inline unsigned long hashCode() const { return (unsigned long)(_k[0] + _k[1] + _k[2] + _k[3]); }
inline bool operator==(const HashKey &k) const { return ( (_k[0] == k._k[0]) && (_k[1] == k._k[1]) && (_k[2] == k._k[2]) && (_k[3] == k._k[3]) ); }
inline bool operator!=(const HashKey &k) const { return (!(*this == k)); }
private:
uint64_t _k[4];
};
Path() :
_lastOut(0),
_lastIn(0),
_lastTrustEstablishedPacketReceived(0),
_incomingLinkQualityFastLog(0xffffffffffffffffULL),
_incomingLinkQualitySlowLogPtr(0),
_incomingLinkQualitySlowLogCounter(-64), // discard first fast log
_incomingLinkQualityPreviousPacketCounter(0),
_outgoingPacketCounter(0),
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_distance(ZT_PATH_DISTANCE_MAX),
_addr(),
_localAddress(),
_ipScope(InetAddress::IP_SCOPE_NONE)
{
for(int i=0;i<(int)sizeof(_incomingLinkQualitySlowLog);++i)
_incomingLinkQualitySlowLog[i] = ZT_PATH_LINK_QUALITY_MAX;
}
Path(const InetAddress &localAddress,const InetAddress &addr) :
_lastOut(0),
_lastIn(0),
_lastTrustEstablishedPacketReceived(0),
_incomingLinkQualityFastLog(0xffffffffffffffffULL),
_incomingLinkQualitySlowLogPtr(0),
_incomingLinkQualitySlowLogCounter(-64), // discard first fast log
_incomingLinkQualityPreviousPacketCounter(0),
_outgoingPacketCounter(0),
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_distance(ZT_PATH_DISTANCE_MAX),
_addr(addr),
_localAddress(localAddress),
_ipScope(addr.ipScope())
{
for(int i=0;i<(int)sizeof(_incomingLinkQualitySlowLog);++i)
_incomingLinkQualitySlowLog[i] = ZT_PATH_LINK_QUALITY_MAX;
}
/**
* Called when a packet is received from this remote path, regardless of content
*
* @param t Time of receive
*/
inline void received(const uint64_t t) { _lastIn = t; }
/**
* Update link quality using a counter from an incoming packet (or packet head in fragmented case)
*
* @param counter Packet link quality counter (range 0 to 7, must not have other bits set)
*/
inline void updateLinkQuality(const unsigned int counter)
{
const unsigned int prev = _incomingLinkQualityPreviousPacketCounter;
_incomingLinkQualityPreviousPacketCounter = counter;
const uint64_t fl = (_incomingLinkQualityFastLog = ((_incomingLinkQualityFastLog << 1) | (uint64_t)(prev == ((counter - 1) & 0x7))));
if (++_incomingLinkQualitySlowLogCounter >= 64) {
_incomingLinkQualitySlowLogCounter = 0;
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_incomingLinkQualitySlowLog[_incomingLinkQualitySlowLogPtr++ % sizeof(_incomingLinkQualitySlowLog)] = (uint8_t)Utils::countBits(fl);
}
}
/**
* @return Link quality from 0 (min) to 255 (max)
*/
inline unsigned int linkQuality() const
{
unsigned long slsize = _incomingLinkQualitySlowLogPtr;
if (slsize > (unsigned long)sizeof(_incomingLinkQualitySlowLog))
slsize = (unsigned long)sizeof(_incomingLinkQualitySlowLog);
else if (!slsize)
return 255; // ZT_PATH_LINK_QUALITY_MAX
unsigned long lq = 0;
for(unsigned long i=0;i<slsize;++i)
lq += (unsigned long)_incomingLinkQualitySlowLog[i] * 4;
lq /= slsize;
return (unsigned int)((lq >= 255) ? 255 : lq);
}
/**
* Set time last trusted packet was received (done in Peer::received())
*/
inline void trustedPacketReceived(const uint64_t t) { _lastTrustEstablishedPacketReceived = t; }
/**
* Send a packet via this path (last out time is also updated)
*
* @param RR Runtime environment
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param data Packet data
* @param len Packet length
* @param now Current time
* @return True if transport reported success
*/
bool send(const RuntimeEnvironment *RR,void *tPtr,const void *data,unsigned int len,uint64_t now);
/**
* Manually update last sent time
*
* @param t Time of send
*/
inline void sent(const uint64_t t) { _lastOut = t; }
/**
* @return Address of local side of this path or NULL if unspecified
*/
inline const InetAddress &localAddress() const { return _localAddress; }
/**
* @return Physical address
*/
inline const InetAddress &address() const { return _addr; }
/**
* @return IP scope -- faster shortcut for address().ipScope()
*/
inline InetAddress::IpScope ipScope() const { return _ipScope; }
/**
* @return True if path has received a trust established packet (e.g. common network membership) in the past ZT_TRUST_EXPIRATION ms
*/
inline bool trustEstablished(const uint64_t now) const { return ((now - _lastTrustEstablishedPacketReceived) < ZT_TRUST_EXPIRATION); }
/**
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* @return Preference rank, higher == better
*/
inline unsigned int preferenceRank() const
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{
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// This causes us to rank paths in order of IP scope rank (see InetAdddress.hpp) but
// within each IP scope class to prefer IPv6 over IPv4.
return ( ((unsigned int)_ipScope << 1) | (unsigned int)(_addr.ss_family == AF_INET6) );
}
/**
* 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)
{
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 True if path appears alive
*/
inline bool alive(const uint64_t now) const { return ((now - _lastIn) <= ZT_PATH_ALIVE_TIMEOUT); }
/**
* @return True if this path needs a heartbeat
*/
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inline bool needsHeartbeat(const uint64_t now) const { return ((now - _lastOut) >= ZT_PATH_HEARTBEAT_PERIOD); }
/**
* @return Last time we sent something
*/
inline uint64_t lastOut() const { return _lastOut; }
/**
* @return Last time we received anything
*/
inline uint64_t lastIn() const { return _lastIn; }
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/**
* @return Time last trust-established packet was received
*/
inline uint64_t lastTrustEstablishedPacketReceived() const { return _lastTrustEstablishedPacketReceived; }
/**
* @return Distance (higher is further)
*/
inline unsigned int distance() const { return _distance; }
/**
* @param lo Last out send
* @param li Last in send
* @param lt Last trust established packet received
*/
inline void updateFromRemoteState(const uint64_t lo,const uint64_t li,const uint64_t lt)
{
_lastOut = lo;
_lastIn = li;
_lastTrustEstablishedPacketReceived = lt;
}
/**
* Return and increment outgoing packet counter (used with Packet::armor())
*
* @return Next value that should be used for outgoing packet counter (only least significant 3 bits are used)
*/
inline unsigned int nextOutgoingCounter() { return _outgoingPacketCounter++; }
private:
volatile uint64_t _lastOut;
volatile uint64_t _lastIn;
volatile uint64_t _lastTrustEstablishedPacketReceived;
volatile uint64_t _incomingLinkQualityFastLog;
volatile unsigned long _incomingLinkQualitySlowLogPtr;
volatile signed int _incomingLinkQualitySlowLogCounter;
volatile unsigned int _incomingLinkQualityPreviousPacketCounter;
volatile unsigned int _outgoingPacketCounter;
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volatile unsigned int _distance;
InetAddress _addr;
InetAddress _localAddress;
InetAddress::IpScope _ipScope; // memoize this since it's a computed value checked often
volatile uint8_t _incomingLinkQualitySlowLog[32];
AtomicCounter __refCount;
};
} // namespace ZeroTier
#endif