ZeroTierOne/core/SelfAwareness.hpp

/*
 * Copyright (c)2013-2020 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: 2025-01-01
 *
 * 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_SELFAWARENESS_HPP
#define ZT_SELFAWARENESS_HPP

#include "Constants.hpp"
#include "InetAddress.hpp"
#include "Containers.hpp"
#include "Address.hpp"
#include "Mutex.hpp"

namespace ZeroTier {

class Identity;

class RuntimeEnvironment;

/**
 * SelfAwareness manages awareness of this peer's external address(es) and NAT situation.
 *
 * Name aside, it shouldn't be capable of achieving sentience.
 */
class SelfAwareness
{
public:
	explicit SelfAwareness(const RuntimeEnvironment *renv);

	/**
	 * Called when a remote peer informs us of our external network address
	 *
	 * @param reporter Identity of reporting peer
	 * @param receivedOnLocalAddress Local address on which report was received
	 * @param reporterPhysicalAddress Physical address that reporting peer seems to have
	 * @param myPhysicalAddress Physical address that peer says we have
	 * @param trusted True if this peer is trusted as an authority to inform us of external address changes
	 * @param now Current time
	 */
	void iam(void *tPtr, const Identity &reporter, int64_t receivedOnLocalSocket, const InetAddress &reporterPhysicalAddress, const InetAddress &myPhysicalAddress, bool trusted, int64_t now);

	/**
	 * Clean up database periodically
	 *
	 * @param now Current time
	 */
	void clean(int64_t now);

	/**
	 * Get external address consensus, which is the statistical "mode" of external addresses.
	 *
	 * @param now Current time
	 * @return Map of count to IP/port representing how many endpoints reported each address
	 */
	MultiMap< unsigned int, InetAddress > externalAddresses(int64_t now) const;

private:
	struct p_PhySurfaceKey
	{
		Address reporter;
		int64_t receivedOnLocalSocket;
		InetAddress reporterPhysicalAddress;
		InetAddress::IpScope scope;

		ZT_INLINE p_PhySurfaceKey() noexcept
		{}

		ZT_INLINE p_PhySurfaceKey(const Address &r, const int64_t rol, const InetAddress &ra, InetAddress::IpScope s) noexcept: reporter(r), receivedOnLocalSocket(rol), reporterPhysicalAddress(ra), scope(s)
		{}

		ZT_INLINE unsigned long hashCode() const noexcept
		{ return ((unsigned long)reporter.toInt() + (unsigned long)receivedOnLocalSocket + (unsigned long)scope); }

		ZT_INLINE bool operator==(const p_PhySurfaceKey &k) const noexcept
		{ return ((reporter == k.reporter) && (receivedOnLocalSocket == k.receivedOnLocalSocket) && (reporterPhysicalAddress == k.reporterPhysicalAddress) && (scope == k.scope)); }

		ZT_INLINE bool operator!=(const p_PhySurfaceKey &k) const noexcept
		{ return (!(*this == k)); }

		ZT_INLINE bool operator<(const p_PhySurfaceKey &k) const noexcept
		{
			if (reporter < k.reporter) {
				return true;
			} else if (reporter == k.reporter) {
				if (receivedOnLocalSocket < k.receivedOnLocalSocket) {
					return true;
				} else if (receivedOnLocalSocket == k.receivedOnLocalSocket) {
					if (reporterPhysicalAddress < k.reporterPhysicalAddress) {
						return true;
					} else if (reporterPhysicalAddress == k.reporterPhysicalAddress) {
						return scope < k.scope;
					}
				}
			}
			return false;
		}
	};

	struct p_PhySurfaceEntry
	{
		InetAddress mySurface;
		int64_t ts;
		bool trusted;

		ZT_INLINE p_PhySurfaceEntry() noexcept: mySurface(), ts(0), trusted(false)
		{}

		ZT_INLINE p_PhySurfaceEntry(const InetAddress &a, const int64_t t) noexcept: mySurface(a), ts(t), trusted(false)
		{}
	};

	const RuntimeEnvironment *RR;
	Map< p_PhySurfaceKey, p_PhySurfaceEntry > m_phy;
	Mutex m_phy_l;
};

} // namespace ZeroTier

#endif