/* * Copyright (c)2013-2021 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: 2026-01-01 * * 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_CONSTANTS_HPP #define ZT_CONSTANTS_HPP /** * Indicates to some parts of zerotier.h that we are building the core */ #define ZT_CORE 1 #include "OS.hpp" #include "zerotier.h" #include "version.h" /** * Length of a ZeroTier address in bytes */ #define ZT_ADDRESS_LENGTH 5 /** * Length of a ZeroTier address in digits */ #define ZT_ADDRESS_LENGTH_HEX 10 /** * Addresses beginning with this byte are reserved for the joy of in-band signaling */ #define ZT_ADDRESS_RESERVED_PREFIX 0xff /** * Bit mask for addresses against a uint64_t */ #define ZT_ADDRESS_MASK 0xffffffffffULL /** * Size of an identity fingerprint hash (SHA384) in bytes */ #define ZT_FINGERPRINT_HASH_SIZE 48 /** * Default virtual network MTU (not physical) */ #define ZT_DEFAULT_MTU 2800 /** * Maximum number of packet fragments we'll support (11 is the maximum that will fit in a Buf) */ #define ZT_MAX_PACKET_FRAGMENTS 11 /** * Anti-DOS limit on the maximum incoming fragments per path */ #define ZT_MAX_INCOMING_FRAGMENTS_PER_PATH 16 /** * Sanity limit on the maximum size of a network config object */ #define ZT_MAX_NETWORK_CONFIG_BYTES 131072 /** * Length of symmetric keys */ #define ZT_SYMMETRIC_KEY_SIZE 48 /** * Time limit for ephemeral keys: 30 minutes. */ #define ZT_SYMMETRIC_KEY_TTL 1800000 /** * Maximum number of messages per symmetric key. */ #define ZT_SYMMETRIC_KEY_TTL_MESSAGES 2147483648 /** * Normal delay between processBackgroundTasks calls. */ #define ZT_TIMER_TASK_INTERVAL 2000 /** * How often most internal cleanup and housekeeping tasks are performed */ #define ZT_HOUSEKEEPING_PERIOD 300000 /** * How often network housekeeping is performed * * Note that this affects how frequently we re-request network configurations * from network controllers if we haven't received one yet. */ #define ZT_NETWORK_HOUSEKEEPING_PERIOD 30000 /** * Period between calls to update() in TrustStore */ #define ZT_TRUSTSTORE_UPDATE_PERIOD 300000 /** * Delay between WHOIS retries in ms */ #define ZT_WHOIS_RETRY_DELAY 500 /** * Maximum number of ZT hops allowed (this is not IP hops/TTL) * * The protocol allows up to 7, but we limit it to something smaller. */ #define ZT_RELAY_MAX_HOPS 4 /** * Period between keepalives sent to paths if no other traffic has been sent. * * The average NAT timeout is 60-120s, but there exist NATs in the wild with timeouts * as short as 30s. Come in just under 30s and we should be fine. */ #define ZT_PATH_KEEPALIVE_PERIOD 28000 /** * Timeout for path alive-ness (measured from last receive) */ #define ZT_PATH_ALIVE_TIMEOUT ((ZT_PATH_KEEPALIVE_PERIOD * 2) + 5000) /** * Maximum number of queued endpoints to try per "pulse." */ #define ZT_NAT_T_PORT_SCAN_MAX 16 /** * Minimum interval between attempts to reach a given physical endpoint */ #define ZT_PATH_MIN_TRY_INTERVAL ZT_PATH_KEEPALIVE_PERIOD /** * Delay between calls to the pulse() method in Peer for each peer */ #define ZT_PEER_PULSE_INTERVAL 8000 /** * Interval between HELLOs to peers. */ #define ZT_PEER_HELLO_INTERVAL 120000 /** * Timeout for peers being alive */ #define ZT_PEER_ALIVE_TIMEOUT ((ZT_PEER_HELLO_INTERVAL * 2) + 5000) /** * Global timeout for peers in milliseconds * * This is global as in "entire world," and this value is 30 days. In this * code the global timeout is used to determine when to ignore cached * peers and their identity<>address mappings. */ #define ZT_PEER_GLOBAL_TIMEOUT 2592000000LL /** * Interval between sort/prioritize of paths for a peer */ #define ZT_PEER_PRIORITIZE_PATHS_INTERVAL 5000 /** * Number of previous endpoints to cache in peer records. */ #define ZT_PEER_ENDPOINT_CACHE_SIZE 8 /** * Delay between requests for updated network autoconf information * * Don't lengthen this as it affects things like QoS / uptime monitoring * via ZeroTier Central. This is the heartbeat, basically. */ #define ZT_NETWORK_AUTOCONF_DELAY 60000 /** * Sanity limit on maximum bridge routes * * If the number of bridge routes exceeds this, we cull routes from the * bridges with the most MACs behind them until it doesn't. This is a * sanity limit to prevent memory-filling DOS attacks, nothing more. No * physical LAN has anywhere even close to this many nodes. Note that this * does not limit the size of ZT virtual LANs, only bridge routing. */ #define ZT_MAX_BRIDGE_ROUTES 16777216 /** * WHOIS rate limit (we allow these to be pretty fast) */ #define ZT_PEER_WHOIS_RATE_LIMIT 100 /** * General rate limit for other kinds of rate-limited packets (HELLO, credential request, etc.) both inbound and outbound */ #define ZT_PEER_GENERAL_RATE_LIMIT 500 /** * Rate limit for responses to short probes to prevent amplification attacks */ #define ZT_PEER_PROBE_RESPONSE_RATE_LIMIT 5000 /** * Size of a buffer to store either a C25519 or an ECC P-384 signature * * This must be large enough to hold all signature types, which right now is * Curve25519 EDDSA and NIST P-384 ECDSA. */ #define ZT_SIGNATURE_BUFFER_SIZE 96 /* Ethernet frame types that might be relevant to us */ #define ZT_ETHERTYPE_IPV4 0x0800 #define ZT_ETHERTYPE_ARP 0x0806 #define ZT_ETHERTYPE_IPV6 0x86dd #endif