/* * Copyright (c)2019 ZeroTier, Inc. * * Use of this software is governed by the Business Source License included * in the LICENSE.TXT file in the project's root directory. * * Change Date: 2023-01-01 * * On the date above, in accordance with the Business Source License, use * of this software will be governed by version 2.0 of the Apache License. */ /****/ #ifndef ZT_N_SWITCH_HPP #define ZT_N_SWITCH_HPP #include #include #include #include #include "Constants.hpp" #include "Mutex.hpp" #include "MAC.hpp" #include "Packet.hpp" #include "Utils.hpp" #include "InetAddress.hpp" #include "Topology.hpp" #include "Network.hpp" #include "SharedPtr.hpp" #include "IncomingPacket.hpp" #include "Hashtable.hpp" /* Ethernet frame types that might be relevant to us */ #define ZT_ETHERTYPE_IPV4 0x0800 #define ZT_ETHERTYPE_ARP 0x0806 #define ZT_ETHERTYPE_RARP 0x8035 #define ZT_ETHERTYPE_ATALK 0x809b #define ZT_ETHERTYPE_AARP 0x80f3 #define ZT_ETHERTYPE_IPX_A 0x8137 #define ZT_ETHERTYPE_IPX_B 0x8138 #define ZT_ETHERTYPE_IPV6 0x86dd 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 { struct ManagedQueue; struct TXQueueEntry; typedef struct { TXQueueEntry *p; bool ok_to_drop; } dqr; 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 localSocket Local I/O socket as supplied by external code * @param fromAddr Internet IP address of origin * @param data Packet data * @param len Packet length */ void onRemotePacket(void *tPtr,const int64_t localSocket,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,const MAC &from,const MAC &to,unsigned int etherType,unsigned int vlanId,const void *data,unsigned int len); /** * Determines the next drop schedule for packets in the TX queue * * @param t Current time * @param count Number of packets dropped this round */ uint64_t control_law(uint64_t t, int count); /** * Selects a packet eligible for transmission from a TX queue. According to the control law, multiple packets * may be intentionally dropped before a packet is returned to the AQM scheduler. * * @param q The TX queue that is being dequeued from * @param now Current time */ dqr dodequeue(ManagedQueue *q, uint64_t now); /** * Presents a packet to the AQM scheduler. * * @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call * @param network Network that the packet shall be sent over * @param packet Packet to be sent * @param encrypt Encrypt packet payload? (always true except for HELLO) * @param qosBucket Which bucket the rule-system determined this packet should fall into */ void aqm_enqueue(void *tPtr, const SharedPtr &network, Packet &packet,bool encrypt,int qosBucket); /** * Performs a single AQM cycle and dequeues and transmits all eligible packets on all networks * * @param tPtr Thread pointer to be handed through to any callbacks called as a result of this call */ void aqm_dequeue(void *tPtr); /** * Calls the dequeue mechanism and adjust queue state variables * * @param q The TX queue that is being dequeued from * @param isNew Whether or not this queue is in the NEW list * @param now Current time */ Switch::TXQueueEntry * CoDelDequeue(ManagedQueue *q, bool isNew, uint64_t now); /** * Removes QoS Queues and flow state variables for a specific network. These queues are created * automatically upon the transmission of the first packet from this peer to another peer on the * given network. * * The reason for existence of queues and flow state variables specific to each network is so that * each network's QoS rules function independently. * * @param nwid Network ID */ void removeNetworkQoSControlBlock(uint64_t nwid); /** * 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 now Current time * @param addr Address to look up */ void requestWhois(void *tPtr,const int64_t now,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); /** * 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,int64_t now); private: bool _shouldUnite(const int64_t now,const Address &source,const Address &destination); bool _trySend(void *tPtr,Packet &packet,bool encrypt); // packet is modified if return is true const RuntimeEnvironment *const RR; int64_t _lastBeaconResponse; volatile int64_t _lastCheckedQueues; // Time we last sent a WHOIS request for each address Hashtable< Address,int64_t > _lastSentWhoisRequest; Mutex _lastSentWhoisRequest_m; // Packets waiting for WHOIS replies or other decode info or missing fragments struct RXQueueEntry { RXQueueEntry() : timestamp(0) {} volatile int64_t timestamp; // 0 if entry is not in use volatile 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 volatile bool complete; // if true, packet is complete Mutex lock; }; RXQueueEntry _rxQueue[ZT_RX_QUEUE_SIZE]; AtomicCounter _rxQueuePtr; // Returns matching or next available RX queue entry inline RXQueueEntry *_findRXQueueEntry(uint64_t packetId) { const unsigned int current = static_cast(_rxQueuePtr.load()); for(unsigned int k=1;k<=ZT_RX_QUEUE_SIZE;++k) { RXQueueEntry *rq = &(_rxQueue[(current - k) % ZT_RX_QUEUE_SIZE]); if ((rq->packetId == packetId)&&(rq->timestamp)) return rq; } ++_rxQueuePtr; return &(_rxQueue[static_cast(current) % ZT_RX_QUEUE_SIZE]); } // Returns current entry in rx queue ring buffer and increments ring pointer inline RXQueueEntry *_nextRXQueueEntry() { return &(_rxQueue[static_cast((++_rxQueuePtr) - 1) % ZT_RX_QUEUE_SIZE]); } // 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; Mutex _aqm_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 { return ((unsigned long)x ^ (unsigned long)y); } inline bool operator==(const _LastUniteKey &k) const { 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; // Queue with additional flow state variables struct ManagedQueue { ManagedQueue(int id) : id(id), byteCredit(ZT_QOS_QUANTUM), byteLength(0), dropping(false) {} int id; int byteCredit; int byteLength; uint64_t first_above_time; uint32_t count; uint64_t drop_next; bool dropping; uint64_t drop_next_time; std::list< TXQueueEntry *> q; }; // To implement fq_codel we need to maintain a queue of queues struct NetworkQoSControlBlock { int _currEnqueuedPackets; std::vector newQueues; std::vector oldQueues; std::vector inactiveQueues; }; std::map _netQueueControlBlock; }; } // namespace ZeroTier #endif