// get canonical identifier of an address' group
// no two connections will be attempted to addresses with the same group
std::vector<unsigned char> CNetAddr::GetGroup() const
{
std::vector<unsigned char> vchRet;
int nClass = NET_IPV6;
int nStartByte = 0;
int nBits = 16;
// all local addresses belong to the same group
if (IsLocal())
{
nClass = 255;
nBits = 0;
}
// all unroutable addresses belong to the same group
if (!IsRoutable())
{
nClass = NET_UNROUTABLE;
nBits = 0;
}
// for IPv4 addresses, '1' + the 16 higher-order bits of the IP
// includes mapped IPv4, SIIT translated IPv4, and the well-known prefix
else if (IsIPv4() || IsRFC6145() || IsRFC6052())
{
nClass = NET_IPV4;
nStartByte = 12;
}
// for 6to4 tunnelled addresses, use the encapsulated IPv4 address
else if (IsRFC3964())
{
nClass = NET_IPV4;
nStartByte = 2;
}
// for Teredo-tunnelled IPv6 addresses, use the encapsulated IPv4 address
else if (IsRFC4380())
{
vchRet.push_back(NET_IPV4);
vchRet.push_back(GetByte(3) ^ 0xFF);
vchRet.push_back(GetByte(2) ^ 0xFF);
return vchRet;
}
// for he.net, use /36 groups
else if (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70)
nBits = 36;
// for the rest of the IPv6 network, use /32 groups
else
nBits = 32;
vchRet.push_back(nClass);
while (nBits >= 8)
{
vchRet.push_back(GetByte(15 - nStartByte));
nStartByte++;
nBits -= 8;
}
if (nBits > 0)
vchRet.push_back(GetByte(15 - nStartByte) | ((1 << nBits) - 1));
return vchRet;
}
/** Calculates a metric for how reachable (*this) is from a given partner */
int CNetAddr::GetReachabilityFrom(const CNetAddr *paddrPartner) const
{
enum Reachability {
REACH_UNREACHABLE,
REACH_DEFAULT,
REACH_TEREDO,
REACH_IPV6_WEAK,
REACH_IPV4,
REACH_IPV6_STRONG,
REACH_PRIVATE
};
if (!IsRoutable())
return REACH_UNREACHABLE;
int ourNet = GetExtNetwork(this);
int theirNet = GetExtNetwork(paddrPartner);
bool fTunnel = IsRFC3964() || IsRFC6052() || IsRFC6145();
switch(theirNet) {
case NET_IPV4:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_IPV4: return REACH_IPV4;
}
case NET_IPV6:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_TEREDO: return REACH_TEREDO;
case NET_IPV4: return REACH_IPV4;
case NET_IPV6: return fTunnel ? REACH_IPV6_WEAK : REACH_IPV6_STRONG; // only prefer giving our IPv6 address if it's not tunnelled
}
case NET_TOR:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_IPV4: return REACH_IPV4; // Tor users can connect to IPv4 as well
case NET_TOR: return REACH_PRIVATE;
}
case NET_TEREDO:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_TEREDO: return REACH_TEREDO;
case NET_IPV6: return REACH_IPV6_WEAK;
case NET_IPV4: return REACH_IPV4;
}
case NET_UNKNOWN:
case NET_UNROUTABLE:
default:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_TEREDO: return REACH_TEREDO;
case NET_IPV6: return REACH_IPV6_WEAK;
case NET_IPV4: return REACH_IPV4;
case NET_TOR: return REACH_PRIVATE; // either from Tor, or don't care about our address
}
}
}
enum Network CNetAddr::GetNetwork() const
{
if (!IsRoutable())
return NET_UNROUTABLE;
if (IsIPv4())
return NET_IPV4;
return NET_IPV6;
}
enum Network CNetAddr::GetNetwork() const
{
if (IsInternal())
return NET_INTERNAL;
if (!IsRoutable())
return NET_UNROUTABLE;
if (IsIPv4())
return NET_IPV4;
if (IsTor())
return NET_ONION;
return NET_IPV6;
}
