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/*
* 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_N_SWITCH_HPP
#define ZT_N_SWITCH_HPP
#include <map>
#include <set>
#include <vector>
#include <list>
#include "Constants.hpp"
#include "Mutex.hpp"
#include "MAC.hpp"
#include "NonCopyable.hpp"
#include "Packet.hpp"
#include "Utils.hpp"
#include "InetAddress.hpp"
#include "Topology.hpp"
#include "Array.hpp"
#include "Network.hpp"
#include "SharedPtr.hpp"
#include "IncomingPacket.hpp"
#include "Hashtable.hpp"
namespace ZeroTier {
class RuntimeEnvironment;
class Peer;
/**
* Core of the distributed Ethernet switch and protocol implementation
*
* This class is perhaps a bit misnamed, but it's basically where everything
* meets. Transport-layer ZT packets come in here, as do virtual network
* packets from tap devices, and this sends them where they need to go and
* wraps/unwraps accordingly. It also handles queues and timeouts and such.
*/
class Switch : NonCopyable
{
public:
Switch(const RuntimeEnvironment *renv);
/**
* Called when a packet is received from the real network
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param localAddr Local interface address
* @param fromAddr Internet IP address of origin
* @param data Packet data
* @param len Packet length
*/
void onRemotePacket(void *tPtr,const InetAddress &localAddr,const InetAddress &fromAddr,const void *data,unsigned int len);
/**
* Called when a packet comes from a local Ethernet tap
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param network Which network's TAP did this packet come from?
* @param from Originating MAC address
* @param to Destination MAC address
* @param etherType Ethernet packet type
* @param vlanId VLAN ID or 0 if none
* @param data Ethernet payload
* @param len Frame length
*/
void onLocalEthernet(void *tPtr,const SharedPtr<Network> &network,const MAC &from,const MAC &to,unsigned int etherType,unsigned int vlanId,const void *data,unsigned int len);
/**
* Send a packet to a ZeroTier address (destination in packet)
*
* The packet must be fully composed with source and destination but not
* yet encrypted. If the destination peer is known the packet
* is sent immediately. Otherwise it is queued and a WHOIS is dispatched.
*
* The packet may be compressed. Compression isn't done here.
*
* Needless to say, the packet's source must be this node. Otherwise it
* won't be encrypted right. (This is not used for relaying.)
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param packet Packet to send (buffer may be modified)
* @param encrypt Encrypt packet payload? (always true except for HELLO)
*/
void send(void *tPtr,Packet &packet,bool encrypt);
/**
* Request WHOIS on a given address
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param addr Address to look up
*/
void requestWhois(void *tPtr,const Address &addr);
/**
* Run any processes that are waiting for this peer's identity
*
* Called when we learn of a peer's identity from HELLO, OK(WHOIS), etc.
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param peer New peer
*/
void doAnythingWaitingForPeer(void *tPtr,const SharedPtr<Peer> &peer);
/**
* Perform retries and other periodic timer tasks
*
* This can return a very long delay if there are no pending timer
* tasks. The caller should cap this comparatively vs. other values.
*
* @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call
* @param now Current time
* @return Number of milliseconds until doTimerTasks() should be run again
*/
unsigned long doTimerTasks(void *tPtr,uint64_t now);
private:
bool _shouldUnite(const uint64_t now,const Address &source,const Address &destination);
Address _sendWhoisRequest(void *tPtr,const Address &addr,const Address *peersAlreadyConsulted,unsigned int numPeersAlreadyConsulted);
bool _trySend(void *tPtr,Packet &packet,bool encrypt); // packet is modified if return is true
const RuntimeEnvironment *const RR;
uint64_t _lastBeaconResponse;
// Outstanding WHOIS requests and how many retries they've undergone
struct WhoisRequest
{
WhoisRequest() : lastSent(0),retries(0) {}
uint64_t lastSent;
Address peersConsulted[ZT_MAX_WHOIS_RETRIES]; // by retry
unsigned int retries; // 0..ZT_MAX_WHOIS_RETRIES
};
Hashtable< Address,WhoisRequest > _outstandingWhoisRequests;
Mutex _outstandingWhoisRequests_m;
// Packets waiting for WHOIS replies or other decode info or missing fragments
struct RXQueueEntry
{
RXQueueEntry() : timestamp(0) {}
uint64_t timestamp; // 0 if entry is not in use
uint64_t packetId;
IncomingPacket frag0; // head of packet
Packet::Fragment frags[ZT_MAX_PACKET_FRAGMENTS - 1]; // later fragments (if any)
unsigned int totalFragments; // 0 if only frag0 received, waiting for frags
uint32_t haveFragments; // bit mask, LSB to MSB
bool complete; // if true, packet is complete
};
RXQueueEntry _rxQueue[ZT_RX_QUEUE_SIZE];
Mutex _rxQueue_m;
/* Returns the matching or oldest entry. Caller must check timestamp and
* packet ID to determine which. */
inline RXQueueEntry *_findRXQueueEntry(uint64_t now,uint64_t packetId)
{
RXQueueEntry *rq;
RXQueueEntry *oldest = &(_rxQueue[ZT_RX_QUEUE_SIZE - 1]);
unsigned long i = ZT_RX_QUEUE_SIZE;
while (i) {
rq = &(_rxQueue[--i]);
if ((rq->packetId == packetId)&&(rq->timestamp))
return rq;
if ((now - rq->timestamp) >= ZT_RX_QUEUE_EXPIRE)
rq->timestamp = 0;
if (rq->timestamp < oldest->timestamp)
oldest = rq;
}
return oldest;
}
// ZeroTier-layer TX queue entry
struct TXQueueEntry
{
TXQueueEntry() {}
TXQueueEntry(Address d,uint64_t ct,const Packet &p,bool enc) :
dest(d),
creationTime(ct),
packet(p),
encrypt(enc) {}
Address dest;
uint64_t creationTime;
Packet packet; // unencrypted/unMAC'd packet -- this is done at send time
bool encrypt;
};
std::list< TXQueueEntry > _txQueue;
Mutex _txQueue_m;
// Tracks sending of VERB_RENDEZVOUS to relaying peers
struct _LastUniteKey
{
_LastUniteKey() : x(0),y(0) {}
_LastUniteKey(const Address &a1,const Address &a2)
{
if (a1 > a2) {
x = a2.toInt();
y = a1.toInt();
} else {
x = a1.toInt();
y = a2.toInt();
}
}
inline unsigned long hashCode() const throw() { return ((unsigned long)x ^ (unsigned long)y); }
inline bool operator==(const _LastUniteKey &k) const throw() { return ((x == k.x)&&(y == k.y)); }
uint64_t x,y;
};
Hashtable< _LastUniteKey,uint64_t > _lastUniteAttempt; // key is always sorted in ascending order, for set-like behavior
Mutex _lastUniteAttempt_m;
};
} // namespace ZeroTier
#endif
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