mirror of
https://github.com/zerotier/ZeroTierOne.git
synced 2024-12-27 00:21:05 +00:00
114 lines
3.3 KiB
C++
114 lines
3.3 KiB
C++
/*
|
|
* 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: 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_MULTICASTGROUP_HPP
|
|
#define ZT_MULTICASTGROUP_HPP
|
|
|
|
#include <stdint.h>
|
|
|
|
#include "MAC.hpp"
|
|
#include "InetAddress.hpp"
|
|
|
|
namespace ZeroTier {
|
|
|
|
/**
|
|
* A multicast group composed of a multicast MAC and a 32-bit ADI field
|
|
*
|
|
* ADI stands for additional distinguishing information. ADI is primarily for
|
|
* adding additional information to broadcast (ff:ff:ff:ff:ff:ff) memberships,
|
|
* since straight-up broadcast won't scale. Right now it's zero except for
|
|
* IPv4 ARP, where it holds the IPv4 address itself to make ARP into a
|
|
* selective multicast query that can scale.
|
|
*
|
|
* In the future we might add some kind of plugin architecture that can add
|
|
* ADI for things like mDNS (multicast DNS) to improve the selectivity of
|
|
* those protocols.
|
|
*
|
|
* MulticastGroup behaves as an immutable value object.
|
|
*/
|
|
class MulticastGroup
|
|
{
|
|
public:
|
|
MulticastGroup() :
|
|
_mac(),
|
|
_adi(0)
|
|
{
|
|
}
|
|
|
|
MulticastGroup(const MAC &m,uint32_t a) :
|
|
_mac(m),
|
|
_adi(a)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Derive the multicast group used for address resolution (ARP/NDP) for an IP
|
|
*
|
|
* @param ip IP address (port field is ignored)
|
|
* @return Multicast group for ARP/NDP
|
|
*/
|
|
static inline MulticastGroup deriveMulticastGroupForAddressResolution(const InetAddress &ip)
|
|
{
|
|
if (ip.isV4()) {
|
|
// IPv4 wants broadcast MACs, so we shove the V4 address itself into
|
|
// the Multicast Group ADI field. Making V4 ARP work is basically why
|
|
// ADI was added, as well as handling other things that want mindless
|
|
// Ethernet broadcast to all.
|
|
return MulticastGroup(MAC(0xffffffffffffULL),Utils::ntoh(*((const uint32_t *)ip.rawIpData())));
|
|
} else if (ip.isV6()) {
|
|
// IPv6 is better designed in this respect. We can compute the IPv6
|
|
// multicast address directly from the IP address, and it gives us
|
|
// 24 bits of uniqueness. Collisions aren't likely to be common enough
|
|
// to care about.
|
|
const unsigned char *a = (const unsigned char *)ip.rawIpData();
|
|
return MulticastGroup(MAC(0x33,0x33,0xff,a[13],a[14],a[15]),0);
|
|
}
|
|
return MulticastGroup();
|
|
}
|
|
|
|
/**
|
|
* @return Multicast address
|
|
*/
|
|
inline const MAC &mac() const { return _mac; }
|
|
|
|
/**
|
|
* @return Additional distinguishing information
|
|
*/
|
|
inline uint32_t adi() const { return _adi; }
|
|
|
|
inline unsigned long hashCode() const { return (_mac.hashCode() ^ (unsigned long)_adi); }
|
|
|
|
inline bool operator==(const MulticastGroup &g) const { return ((_mac == g._mac)&&(_adi == g._adi)); }
|
|
inline bool operator!=(const MulticastGroup &g) const { return ((_mac != g._mac)||(_adi != g._adi)); }
|
|
inline bool operator<(const MulticastGroup &g) const
|
|
{
|
|
if (_mac < g._mac) {
|
|
return true;
|
|
} else if (_mac == g._mac) {
|
|
return (_adi < g._adi);
|
|
}
|
|
return false;
|
|
}
|
|
inline bool operator>(const MulticastGroup &g) const { return (g < *this); }
|
|
inline bool operator<=(const MulticastGroup &g) const { return !(g < *this); }
|
|
inline bool operator>=(const MulticastGroup &g) const { return !(*this < g); }
|
|
|
|
private:
|
|
MAC _mac;
|
|
uint32_t _adi;
|
|
};
|
|
|
|
} // namespace ZeroTier
|
|
|
|
#endif
|