/*
* 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"
#include "SharedPtr.hpp"
#include "AtomicCounter.hpp"
#include "NonCopyable.hpp"
/**
* Maximum return value of preferenceRank()
*/
#define ZT_PATH_MAX_PREFERENCE_RANK ((ZT_INETADDRESS_MAX_SCOPE << 1) | 1)
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),
_addr(),
_localAddress(),
_ipScope(InetAddress::IP_SCOPE_NONE)
{
}
Path(const InetAddress &localAddress,const InetAddress &addr) :
_lastOut(0),
_lastIn(0),
_addr(addr),
_localAddress(localAddress),
_ipScope(addr.ipScope())
{
}
/**
* 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; }
/**
* Send a packet via this path (last out time is also updated)
*
* @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);
/**
* 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 Preference rank, higher == better
*/
inline unsigned int preferenceRank() const
{
// 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
*/
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; }
private:
uint64_t _lastOut;
uint64_t _lastIn;
InetAddress _addr;
InetAddress _localAddress;
InetAddress::IpScope _ipScope; // memoize this since it's a computed value checked often
AtomicCounter __refCount;
};
} // namespace ZeroTier
#endif