More threading improvements in root, more DNS TXT and multicast work (in progress)

attic/Root.hpp

@@ -0,0 +1,182 @@
+/*
+ * 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_ROOT_HPP
+#define ZT_ROOT_HPP
+
+#include "Constants.hpp"
+#include "Str.hpp"
+#include "ECC384.hpp"
+#include "Locator.hpp"
+#include "InetAddress.hpp"
+#include "Utils.hpp"
+#include "Identity.hpp"
+#include "Mutex.hpp"
+
+namespace ZeroTier {
+
+/**
+ * A root entry pointing to a node capable of global identity lookup and indirect transit
+ *
+ * Root entries point to DNS records that contain TXT entries that decode to Locator objects
+ * pointing to actual root nodes. A default root identity and static addresses can also be
+ * provided as fallback if DNS is not available.
+ *
+ * Note that root identities can change if DNS returns a different result, but that DNS entries
+ * are authenticated using their own signature scheme. This allows a root DNS name to serve
+ * up different roots based on factors like location or relative load of different roots.
+ *
+ * It's also possible to create a root with no DNS and no DNS validator public key. This root
+ * will be a static entry pointing to a single root identity and set of physical addresses.
+ */
+class Root
+{
+public:
+	ZT_ALWAYS_INLINE Root() : _dnsPublicKeySize(0) {}
+
+	/**
+	 * Create a new root entry
+	 *
+	 * @param dn DNS name
+	 * @param dnspk DNS public key for record validation
+	 * @param dnspksize Size of DNS public key (currently always the size of a NIST P-384 point compressed public key)
+	 * @param dflId Default identity if DNS is not available
+	 * @param dflAddrs Default IP addresses if DNS is not available
+	 */
+	template<typename S>
+	ZT_ALWAYS_INLINE Root(S dn,const uint8_t *const dnspk,const unsigned int dnspksize,const Identity &dflId,const std::vector<InetAddress> &dflAddrs) :
+		_defaultIdentity(dflId),
+		_defaultAddresses(dflAddrs),
+		_dnsName(dn),
+		_dnsPublicKeySize(dnspksize)
+	{
+		if (dnspksize != 0) {
+			if (dnspksize > sizeof(_dnsPublicKey))
+				throw ZT_EXCEPTION_INVALID_ARGUMENT;
+			memcpy(_dnsPublicKey,dnspk,dnspksize);
+		}
+	}
+
+	/**
+	 * @return Current identity (either default or latest locator)
+	 */
+	ZT_ALWAYS_INLINE const Identity id() const
+	{
+		if (_lastFetchedLocator.id())
+			return _lastFetchedLocator.id();
+		return _defaultIdentity;
+	}
+
+	/**
+	 * @param id Identity to check
+	 * @return True if identity equals this root's current identity
+	 */
+	ZT_ALWAYS_INLINE bool is(const Identity &id) const
+	{
+		return ((_lastFetchedLocator.id()) ? (id == _lastFetchedLocator.id()) : (id == _defaultIdentity));
+	}
+
+	/**
+	 * @return Current ZeroTier address (either default or latest locator)
+	 */
+	ZT_ALWAYS_INLINE const Address address() const
+	{
+		if (_lastFetchedLocator.id())
+			return _lastFetchedLocator.id().address();
+		return _defaultIdentity.address();
+	}
+
+	/**
+	 * @return DNS name for this root or empty string if static entry with no DNS
+	 */
+	ZT_ALWAYS_INLINE const Str dnsName() const { return _dnsName; }
+
+	/**
+	 * @return Latest locator or NIL locator object if none
+	 */
+	ZT_ALWAYS_INLINE Locator locator() const { return _lastFetchedLocator; }
+
+	/**
+	 * @return Timestamp of latest retrieved locator or 0 if none
+	 */
+	ZT_ALWAYS_INLINE int64_t locatorTimestamp() const { return _lastFetchedLocator.timestamp(); }
+
+	/**
+	 * Update locator, returning true if new locator is valid and newer than existing
+	 */
+	ZT_ALWAYS_INLINE bool updateLocator(const Locator &loc)
+	{
+		if (!loc.verify())
+			return false;
+		if ((loc.phy().size() > 0)&&(loc.timestamp() > _lastFetchedLocator.timestamp())) {
+			_lastFetchedLocator = loc;
+			return true;
+		}
+		return false;
+	}
+
+	/**
+	 * Update this root's locator from a series of TXT records
+	 */
+	template<typename I>
+	ZT_ALWAYS_INLINE bool updateLocatorFromTxt(I start,I end)
+	{
+		try {
+			if (_dnsPublicKeySize != ZT_ECC384_PUBLIC_KEY_SIZE)
+				return false;
+			Locator loc;
+			if (!loc.decodeTxtRecords(start,end,_dnsPublicKey)) // also does verify()
+				return false;
+			if ((loc.phy().size() > 0)&&(loc.timestamp() > _lastFetchedLocator.timestamp())) {
+				_lastFetchedLocator = loc;
+				return true;
+			}
+			return false;
+		} catch ( ... ) {}
+		return false;
+	}
+
+	/**
+	 * Pick a random physical IP for this root with the given address family
+	 *
+	 * @param addressFamily AF_INET or AF_INET6
+	 * @return Address or InetAddress::NIL if no addresses exist for the given family
+	 */
+	ZT_ALWAYS_INLINE const InetAddress &pickPhysical(const int addressFamily) const
+	{
+		std::vector<const InetAddress *> pickList;
+		const std::vector<InetAddress> *const av = (_lastFetchedLocator) ? &(_lastFetchedLocator.phy()) : &_defaultAddresses;
+		for(std::vector<InetAddress>::const_iterator i(av->begin());i!=av->end();++i) {
+			if (addressFamily == (int)i->ss_family) {
+				pickList.push_back(&(*i));
+			}
+		}
+		if (pickList.size() == 1)
+			return *pickList[0];
+		else if (pickList.size() > 1)
+			return *pickList[(unsigned long)Utils::random() % (unsigned long)pickList.size()];
+		return InetAddress::NIL;
+	}
+
+private:
+	Identity _defaultIdentity;
+	std::vector<InetAddress> _defaultAddresses;
+	Str _dnsName;
+	Locator _lastFetchedLocator;
+	unsigned int _dnsPublicKeySize;
+	uint8_t _dnsPublicKey[ZT_ECC384_PUBLIC_KEY_SIZE];
+};
+
+} // namespace ZeroTier
+
+#endif