nastools_zerotierone/node/MAC.hpp
2016-11-01 16:45:16 -07:00

265 lines
7.5 KiB
C++

/*
* ZeroTier One - Network Virtualization Everywhere
* Copyright (C) 2011-2016 ZeroTier, Inc. https://www.zerotier.com/
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef ZT_MAC_HPP
#define ZT_MAC_HPP
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include "Constants.hpp"
#include "Utils.hpp"
#include "Address.hpp"
#include "Buffer.hpp"
namespace ZeroTier {
/**
* 48-byte Ethernet MAC address
*/
class MAC
{
public:
MAC() throw() : _m(0ULL) {}
MAC(const MAC &m) throw() : _m(m._m) {}
MAC(const unsigned char a,const unsigned char b,const unsigned char c,const unsigned char d,const unsigned char e,const unsigned char f) throw() :
_m( ((((uint64_t)a) & 0xffULL) << 40) |
((((uint64_t)b) & 0xffULL) << 32) |
((((uint64_t)c) & 0xffULL) << 24) |
((((uint64_t)d) & 0xffULL) << 16) |
((((uint64_t)e) & 0xffULL) << 8) |
(((uint64_t)f) & 0xffULL) ) {}
MAC(const char *s) throw() { fromString(s); }
MAC(const std::string &s) throw() { fromString(s.c_str()); }
MAC(const void *bits,unsigned int len) throw() { setTo(bits,len); }
MAC(const Address &ztaddr,uint64_t nwid) throw() { fromAddress(ztaddr,nwid); }
MAC(const uint64_t m) throw() : _m(m & 0xffffffffffffULL) {}
/**
* @return MAC in 64-bit integer
*/
inline uint64_t toInt() const throw() { return _m; }
/**
* Set MAC to zero
*/
inline void zero() { _m = 0ULL; }
/**
* @return True if MAC is non-zero
*/
inline operator bool() const throw() { return (_m != 0ULL); }
/**
* @param bits Raw MAC in big-endian byte order
* @param len Length, must be >= 6 or result is zero
*/
inline void setTo(const void *bits,unsigned int len)
throw()
{
if (len < 6) {
_m = 0ULL;
return;
}
const unsigned char *b = (const unsigned char *)bits;
_m = ((((uint64_t)*b) & 0xff) << 40); ++b;
_m |= ((((uint64_t)*b) & 0xff) << 32); ++b;
_m |= ((((uint64_t)*b) & 0xff) << 24); ++b;
_m |= ((((uint64_t)*b) & 0xff) << 16); ++b;
_m |= ((((uint64_t)*b) & 0xff) << 8); ++b;
_m |= (((uint64_t)*b) & 0xff);
}
/**
* @param buf Destination buffer for MAC in big-endian byte order
* @param len Length of buffer, must be >= 6 or nothing is copied
*/
inline void copyTo(void *buf,unsigned int len) const
throw()
{
if (len < 6)
return;
unsigned char *b = (unsigned char *)buf;
*(b++) = (unsigned char)((_m >> 40) & 0xff);
*(b++) = (unsigned char)((_m >> 32) & 0xff);
*(b++) = (unsigned char)((_m >> 24) & 0xff);
*(b++) = (unsigned char)((_m >> 16) & 0xff);
*(b++) = (unsigned char)((_m >> 8) & 0xff);
*b = (unsigned char)(_m & 0xff);
}
/**
* Append to a buffer in big-endian byte order
*
* @param b Buffer to append to
*/
template<unsigned int C>
inline void appendTo(Buffer<C> &b) const
throw(std::out_of_range)
{
unsigned char *p = (unsigned char *)b.appendField(6);
*(p++) = (unsigned char)((_m >> 40) & 0xff);
*(p++) = (unsigned char)((_m >> 32) & 0xff);
*(p++) = (unsigned char)((_m >> 24) & 0xff);
*(p++) = (unsigned char)((_m >> 16) & 0xff);
*(p++) = (unsigned char)((_m >> 8) & 0xff);
*p = (unsigned char)(_m & 0xff);
}
/**
* @return True if this is broadcast (all 0xff)
*/
inline bool isBroadcast() const throw() { return (_m == 0xffffffffffffULL); }
/**
* @return True if this is a multicast MAC
*/
inline bool isMulticast() const throw() { return ((_m & 0x010000000000ULL) != 0ULL); }
/**
* @param True if this is a locally-administered MAC
*/
inline bool isLocallyAdministered() const throw() { return ((_m & 0x020000000000ULL) != 0ULL); }
/**
* @param s Hex MAC, with or without : delimiters
*/
inline void fromString(const char *s)
{
char tmp[8];
for(int i=0;i<6;++i)
tmp[i] = (char)0;
Utils::unhex(s,tmp,6);
setTo(tmp,6);
}
/**
* @return MAC address in standard :-delimited hex format
*/
inline std::string toString() const
{
char tmp[24];
toString(tmp,sizeof(tmp));
return std::string(tmp);
}
/**
* @param buf Buffer to contain human-readable MAC
* @param len Length of buffer
*/
inline void toString(char *buf,unsigned int len) const
{
Utils::snprintf(buf,len,"%.2x:%.2x:%.2x:%.2x:%.2x:%.2x",(int)(*this)[0],(int)(*this)[1],(int)(*this)[2],(int)(*this)[3],(int)(*this)[4],(int)(*this)[5]);
}
/**
* Set this MAC to a MAC derived from an address and a network ID
*
* @param ztaddr ZeroTier address
* @param nwid 64-bit network ID
*/
inline void fromAddress(const Address &ztaddr,uint64_t nwid)
throw()
{
uint64_t m = ((uint64_t)firstOctetForNetwork(nwid)) << 40;
m |= ztaddr.toInt(); // a is 40 bits
m ^= ((nwid >> 8) & 0xff) << 32;
m ^= ((nwid >> 16) & 0xff) << 24;
m ^= ((nwid >> 24) & 0xff) << 16;
m ^= ((nwid >> 32) & 0xff) << 8;
m ^= (nwid >> 40) & 0xff;
_m = m;
}
/**
* Get the ZeroTier address for this MAC on this network (assuming no bridging of course, basic unicast)
*
* This just XORs the next-lest-significant 5 bytes of the network ID again to unmask.
*
* @param nwid Network ID
*/
inline Address toAddress(uint64_t nwid) const
throw()
{
uint64_t a = _m & 0xffffffffffULL; // least significant 40 bits of MAC are formed from address
a ^= ((nwid >> 8) & 0xff) << 32; // ... XORed with bits 8-48 of the nwid in little-endian byte order, so unmask it
a ^= ((nwid >> 16) & 0xff) << 24;
a ^= ((nwid >> 24) & 0xff) << 16;
a ^= ((nwid >> 32) & 0xff) << 8;
a ^= (nwid >> 40) & 0xff;
return Address(a);
}
/**
* @param nwid Network ID
* @return First octet of MAC for this network
*/
static inline unsigned char firstOctetForNetwork(uint64_t nwid)
throw()
{
unsigned char a = ((unsigned char)(nwid & 0xfe) | 0x02); // locally administered, not multicast, from LSB of network ID
return ((a == 0x52) ? 0x32 : a); // blacklist 0x52 since it's used by KVM, libvirt, and other popular virtualization engines... seems de-facto standard on Linux
}
/**
* @param i Value from 0 to 5 (inclusive)
* @return Byte at said position (address interpreted in big-endian order)
*/
inline unsigned char operator[](unsigned int i) const throw() { return (unsigned char)((_m >> (40 - (i * 8))) & 0xff); }
/**
* @return 6, which is the number of bytes in a MAC, for container compliance
*/
inline unsigned int size() const throw() { return 6; }
inline unsigned long hashCode() const throw() { return (unsigned long)_m; }
inline MAC &operator=(const MAC &m)
throw()
{
_m = m._m;
return *this;
}
inline MAC &operator=(const uint64_t m)
throw()
{
_m = m;
return *this;
}
inline bool operator==(const MAC &m) const throw() { return (_m == m._m); }
inline bool operator!=(const MAC &m) const throw() { return (_m != m._m); }
inline bool operator<(const MAC &m) const throw() { return (_m < m._m); }
inline bool operator<=(const MAC &m) const throw() { return (_m <= m._m); }
inline bool operator>(const MAC &m) const throw() { return (_m > m._m); }
inline bool operator>=(const MAC &m) const throw() { return (_m >= m._m); }
private:
uint64_t _m;
};
} // namespace ZeroTier
#endif