lbrycrd/src/netaddress.cpp
Ben Woosley b748bf6f50
Fix spelling errors identified by codespell 1.15.0
After this commit, the only remaining output is:

  $ test/lint/lint-spelling.sh
  src/test/base32_tests.cpp:14: fo  ==> of, for
  src/test/base64_tests.cpp:14: fo  ==> of, for
  ^ Warning: codespell identified likely spelling errors. Any false positives? Add them to the list of ignored words in test/lint/lint-spelling.ignore-words.txt

Note:
* I ignore several valid alternative spellings
* homogenous is present in tinyformat, hence should be addressed upstream
* process' is correct only if there are plural processes
2019-06-11 17:18:16 +02:00

839 lines
24 KiB
C++

// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <netaddress.h>
#include <hash.h>
#include <util/strencodings.h>
#include <tinyformat.h>
static const unsigned char pchIPv4[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff };
static const unsigned char pchOnionCat[] = {0xFD,0x87,0xD8,0x7E,0xEB,0x43};
// 0xFD + sha256("bitcoin")[0:5]
static const unsigned char g_internal_prefix[] = { 0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 };
/**
* Construct an unspecified IPv6 network address (::/128).
*
* @note This address is considered invalid by CNetAddr::IsValid()
*/
CNetAddr::CNetAddr()
{
memset(ip, 0, sizeof(ip));
}
void CNetAddr::SetIP(const CNetAddr& ipIn)
{
memcpy(ip, ipIn.ip, sizeof(ip));
}
void CNetAddr::SetRaw(Network network, const uint8_t *ip_in)
{
switch(network)
{
case NET_IPV4:
memcpy(ip, pchIPv4, 12);
memcpy(ip+12, ip_in, 4);
break;
case NET_IPV6:
memcpy(ip, ip_in, 16);
break;
default:
assert(!"invalid network");
}
}
/**
* Try to make this a dummy address that maps the specified name into IPv6 like
* so: (0xFD + %sha256("bitcoin")[0:5]) + %sha256(name)[0:10]. Such dummy
* addresses have a prefix of fd6b:88c0:8724::/48 and are guaranteed to not be
* publicly routable as it falls under RFC4193's fc00::/7 subnet allocated to
* unique-local addresses.
*
* CAddrMan uses these fake addresses to keep track of which DNS seeds were
* used.
*
* @returns Whether or not the operation was successful.
*
* @see CNetAddr::IsInternal(), CNetAddr::IsRFC4193()
*/
bool CNetAddr::SetInternal(const std::string &name)
{
if (name.empty()) {
return false;
}
unsigned char hash[32] = {};
CSHA256().Write((const unsigned char*)name.data(), name.size()).Finalize(hash);
memcpy(ip, g_internal_prefix, sizeof(g_internal_prefix));
memcpy(ip + sizeof(g_internal_prefix), hash, sizeof(ip) - sizeof(g_internal_prefix));
return true;
}
/**
* Try to make this a dummy address that maps the specified onion address into
* IPv6 using OnionCat's range and encoding. Such dummy addresses have a prefix
* of fd87:d87e:eb43::/48 and are guaranteed to not be publicly routable as they
* fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses.
*
* @returns Whether or not the operation was successful.
*
* @see CNetAddr::IsTor(), CNetAddr::IsRFC4193()
*/
bool CNetAddr::SetSpecial(const std::string &strName)
{
if (strName.size()>6 && strName.substr(strName.size() - 6, 6) == ".onion") {
std::vector<unsigned char> vchAddr = DecodeBase32(strName.substr(0, strName.size() - 6).c_str());
if (vchAddr.size() != 16-sizeof(pchOnionCat))
return false;
memcpy(ip, pchOnionCat, sizeof(pchOnionCat));
for (unsigned int i=0; i<16-sizeof(pchOnionCat); i++)
ip[i + sizeof(pchOnionCat)] = vchAddr[i];
return true;
}
return false;
}
CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
{
SetRaw(NET_IPV4, (const uint8_t*)&ipv4Addr);
}
CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope)
{
SetRaw(NET_IPV6, (const uint8_t*)&ipv6Addr);
scopeId = scope;
}
unsigned int CNetAddr::GetByte(int n) const
{
return ip[15-n];
}
bool CNetAddr::IsBindAny() const
{
const int cmplen = IsIPv4() ? 4 : 16;
for (int i = 0; i < cmplen; ++i) {
if (GetByte(i)) return false;
}
return true;
}
bool CNetAddr::IsIPv4() const
{
return (memcmp(ip, pchIPv4, sizeof(pchIPv4)) == 0);
}
bool CNetAddr::IsIPv6() const
{
return (!IsIPv4() && !IsTor() && !IsInternal());
}
bool CNetAddr::IsRFC1918() const
{
return IsIPv4() && (
GetByte(3) == 10 ||
(GetByte(3) == 192 && GetByte(2) == 168) ||
(GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31)));
}
bool CNetAddr::IsRFC2544() const
{
return IsIPv4() && GetByte(3) == 198 && (GetByte(2) == 18 || GetByte(2) == 19);
}
bool CNetAddr::IsRFC3927() const
{
return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254);
}
bool CNetAddr::IsRFC6598() const
{
return IsIPv4() && GetByte(3) == 100 && GetByte(2) >= 64 && GetByte(2) <= 127;
}
bool CNetAddr::IsRFC5737() const
{
return IsIPv4() && ((GetByte(3) == 192 && GetByte(2) == 0 && GetByte(1) == 2) ||
(GetByte(3) == 198 && GetByte(2) == 51 && GetByte(1) == 100) ||
(GetByte(3) == 203 && GetByte(2) == 0 && GetByte(1) == 113));
}
bool CNetAddr::IsRFC3849() const
{
return GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x0D && GetByte(12) == 0xB8;
}
bool CNetAddr::IsRFC3964() const
{
return (GetByte(15) == 0x20 && GetByte(14) == 0x02);
}
bool CNetAddr::IsRFC6052() const
{
static const unsigned char pchRFC6052[] = {0,0x64,0xFF,0x9B,0,0,0,0,0,0,0,0};
return (memcmp(ip, pchRFC6052, sizeof(pchRFC6052)) == 0);
}
bool CNetAddr::IsRFC4380() const
{
return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0 && GetByte(12) == 0);
}
bool CNetAddr::IsRFC4862() const
{
static const unsigned char pchRFC4862[] = {0xFE,0x80,0,0,0,0,0,0};
return (memcmp(ip, pchRFC4862, sizeof(pchRFC4862)) == 0);
}
bool CNetAddr::IsRFC4193() const
{
return ((GetByte(15) & 0xFE) == 0xFC);
}
bool CNetAddr::IsRFC6145() const
{
static const unsigned char pchRFC6145[] = {0,0,0,0,0,0,0,0,0xFF,0xFF,0,0};
return (memcmp(ip, pchRFC6145, sizeof(pchRFC6145)) == 0);
}
bool CNetAddr::IsRFC4843() const
{
return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x10);
}
bool CNetAddr::IsRFC7343() const
{
return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x20);
}
/**
* @returns Whether or not this is a dummy address that maps an onion address
* into IPv6.
*
* @see CNetAddr::SetSpecial(const std::string &)
*/
bool CNetAddr::IsTor() const
{
return (memcmp(ip, pchOnionCat, sizeof(pchOnionCat)) == 0);
}
bool CNetAddr::IsLocal() const
{
// IPv4 loopback (127.0.0.0/8 or 0.0.0.0/8)
if (IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0))
return true;
// IPv6 loopback (::1/128)
static const unsigned char pchLocal[16] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1};
if (memcmp(ip, pchLocal, 16) == 0)
return true;
return false;
}
/**
* @returns Whether or not this network address is a valid address that @a could
* be used to refer to an actual host.
*
* @note A valid address may or may not be publicly routable on the global
* internet. As in, the set of valid addresses is a superset of the set of
* publicly routable addresses.
*
* @see CNetAddr::IsRoutable()
*/
bool CNetAddr::IsValid() const
{
// Cleanup 3-byte shifted addresses caused by garbage in size field
// of addr messages from versions before 0.2.9 checksum.
// Two consecutive addr messages look like this:
// header20 vectorlen3 addr26 addr26 addr26 header20 vectorlen3 addr26 addr26 addr26...
// so if the first length field is garbled, it reads the second batch
// of addr misaligned by 3 bytes.
if (memcmp(ip, pchIPv4+3, sizeof(pchIPv4)-3) == 0)
return false;
// unspecified IPv6 address (::/128)
unsigned char ipNone6[16] = {};
if (memcmp(ip, ipNone6, 16) == 0)
return false;
// documentation IPv6 address
if (IsRFC3849())
return false;
if (IsInternal())
return false;
if (IsIPv4())
{
// INADDR_NONE
uint32_t ipNone = INADDR_NONE;
if (memcmp(ip+12, &ipNone, 4) == 0)
return false;
// 0
ipNone = 0;
if (memcmp(ip+12, &ipNone, 4) == 0)
return false;
}
return true;
}
/**
* @returns Whether or not this network address is publicly routable on the
* global internet.
*
* @note A routable address is always valid. As in, the set of routable addresses
* is a subset of the set of valid addresses.
*
* @see CNetAddr::IsValid()
*/
bool CNetAddr::IsRoutable() const
{
return IsValid() && !(IsRFC1918() || IsRFC2544() || IsRFC3927() || IsRFC4862() || IsRFC6598() || IsRFC5737() || (IsRFC4193() && !IsTor()) || IsRFC4843() || IsRFC7343() || IsLocal() || IsInternal());
}
/**
* @returns Whether or not this is a dummy address that maps a name into IPv6.
*
* @see CNetAddr::SetInternal(const std::string &)
*/
bool CNetAddr::IsInternal() const
{
return memcmp(ip, g_internal_prefix, sizeof(g_internal_prefix)) == 0;
}
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;
}
std::string CNetAddr::ToStringIP() const
{
if (IsTor())
return EncodeBase32(&ip[6], 10) + ".onion";
if (IsInternal())
return EncodeBase32(ip + sizeof(g_internal_prefix), sizeof(ip) - sizeof(g_internal_prefix)) + ".internal";
CService serv(*this, 0);
struct sockaddr_storage sockaddr;
socklen_t socklen = sizeof(sockaddr);
if (serv.GetSockAddr((struct sockaddr*)&sockaddr, &socklen)) {
char name[1025] = "";
if (!getnameinfo((const struct sockaddr*)&sockaddr, socklen, name, sizeof(name), nullptr, 0, NI_NUMERICHOST))
return std::string(name);
}
if (IsIPv4())
return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0));
else
return strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
GetByte(15) << 8 | GetByte(14), GetByte(13) << 8 | GetByte(12),
GetByte(11) << 8 | GetByte(10), GetByte(9) << 8 | GetByte(8),
GetByte(7) << 8 | GetByte(6), GetByte(5) << 8 | GetByte(4),
GetByte(3) << 8 | GetByte(2), GetByte(1) << 8 | GetByte(0));
}
std::string CNetAddr::ToString() const
{
return ToStringIP();
}
bool operator==(const CNetAddr& a, const CNetAddr& b)
{
return (memcmp(a.ip, b.ip, 16) == 0);
}
bool operator<(const CNetAddr& a, const CNetAddr& b)
{
return (memcmp(a.ip, b.ip, 16) < 0);
}
/**
* Try to get our IPv4 address.
*
* @param[out] pipv4Addr The in_addr struct to which to copy.
*
* @returns Whether or not the operation was successful, in particular, whether
* or not our address was an IPv4 address.
*
* @see CNetAddr::IsIPv4()
*/
bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
{
if (!IsIPv4())
return false;
memcpy(pipv4Addr, ip+12, 4);
return true;
}
/**
* Try to get our IPv6 address.
*
* @param[out] pipv6Addr The in6_addr struct to which to copy.
*
* @returns Whether or not the operation was successful, in particular, whether
* or not our address was an IPv6 address.
*
* @see CNetAddr::IsIPv6()
*/
bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
{
if (!IsIPv6()) {
return false;
}
memcpy(pipv6Addr, ip, 16);
return true;
}
/**
* Get the canonical identifier of our network group
*
* The groups are assigned in a way where it should be costly for an attacker to
* obtain addresses with many different group identifiers, even if it is cheap
* to obtain addresses with the same identifier.
*
* @note No two connections will be attempted to addresses with the same network
* 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 internal-usage addresses get their own group
if (IsInternal())
{
nClass = NET_INTERNAL;
nStartByte = sizeof(g_internal_prefix);
nBits = (sizeof(ip) - sizeof(g_internal_prefix)) * 8;
}
// all other unroutable addresses belong to the same group
else 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;
}
else if (IsTor())
{
nClass = NET_ONION;
nStartByte = 6;
nBits = 4;
}
// 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);
// push our ip onto vchRet byte by byte...
while (nBits >= 8)
{
vchRet.push_back(GetByte(15 - nStartByte));
nStartByte++;
nBits -= 8;
}
// ...for the last byte, push nBits and for the rest of the byte push 1's
if (nBits > 0)
vchRet.push_back(GetByte(15 - nStartByte) | ((1 << (8 - nBits)) - 1));
return vchRet;
}
uint64_t CNetAddr::GetHash() const
{
uint256 hash = Hash(&ip[0], &ip[16]);
uint64_t nRet;
memcpy(&nRet, &hash, sizeof(nRet));
return nRet;
}
// private extensions to enum Network, only returned by GetExtNetwork,
// and only used in GetReachabilityFrom
static const int NET_UNKNOWN = NET_MAX + 0;
static const int NET_TEREDO = NET_MAX + 1;
int static GetExtNetwork(const CNetAddr *addr)
{
if (addr == nullptr)
return NET_UNKNOWN;
if (addr->IsRFC4380())
return NET_TEREDO;
return addr->GetNetwork();
}
/** 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() || IsInternal())
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_ONION:
switch(ourNet) {
default: return REACH_DEFAULT;
case NET_IPV4: return REACH_IPV4; // Tor users can connect to IPv4 as well
case NET_ONION: 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_ONION: return REACH_PRIVATE; // either from Tor, or don't care about our address
}
}
}
CService::CService() : port(0)
{
}
CService::CService(const CNetAddr& cip, unsigned short portIn) : CNetAddr(cip), port(portIn)
{
}
CService::CService(const struct in_addr& ipv4Addr, unsigned short portIn) : CNetAddr(ipv4Addr), port(portIn)
{
}
CService::CService(const struct in6_addr& ipv6Addr, unsigned short portIn) : CNetAddr(ipv6Addr), port(portIn)
{
}
CService::CService(const struct sockaddr_in& addr) : CNetAddr(addr.sin_addr), port(ntohs(addr.sin_port))
{
assert(addr.sin_family == AF_INET);
}
CService::CService(const struct sockaddr_in6 &addr) : CNetAddr(addr.sin6_addr, addr.sin6_scope_id), port(ntohs(addr.sin6_port))
{
assert(addr.sin6_family == AF_INET6);
}
bool CService::SetSockAddr(const struct sockaddr *paddr)
{
switch (paddr->sa_family) {
case AF_INET:
*this = CService(*(const struct sockaddr_in*)paddr);
return true;
case AF_INET6:
*this = CService(*(const struct sockaddr_in6*)paddr);
return true;
default:
return false;
}
}
unsigned short CService::GetPort() const
{
return port;
}
bool operator==(const CService& a, const CService& b)
{
return static_cast<CNetAddr>(a) == static_cast<CNetAddr>(b) && a.port == b.port;
}
bool operator<(const CService& a, const CService& b)
{
return static_cast<CNetAddr>(a) < static_cast<CNetAddr>(b) || (static_cast<CNetAddr>(a) == static_cast<CNetAddr>(b) && a.port < b.port);
}
/**
* Obtain the IPv4/6 socket address this represents.
*
* @param[out] paddr The obtained socket address.
* @param[in,out] addrlen The size, in bytes, of the address structure pointed
* to by paddr. The value that's pointed to by this
* parameter might change after calling this function if
* the size of the corresponding address structure
* changed.
*
* @returns Whether or not the operation was successful.
*/
bool CService::GetSockAddr(struct sockaddr* paddr, socklen_t *addrlen) const
{
if (IsIPv4()) {
if (*addrlen < (socklen_t)sizeof(struct sockaddr_in))
return false;
*addrlen = sizeof(struct sockaddr_in);
struct sockaddr_in *paddrin = (struct sockaddr_in*)paddr;
memset(paddrin, 0, *addrlen);
if (!GetInAddr(&paddrin->sin_addr))
return false;
paddrin->sin_family = AF_INET;
paddrin->sin_port = htons(port);
return true;
}
if (IsIPv6()) {
if (*addrlen < (socklen_t)sizeof(struct sockaddr_in6))
return false;
*addrlen = sizeof(struct sockaddr_in6);
struct sockaddr_in6 *paddrin6 = (struct sockaddr_in6*)paddr;
memset(paddrin6, 0, *addrlen);
if (!GetIn6Addr(&paddrin6->sin6_addr))
return false;
paddrin6->sin6_scope_id = scopeId;
paddrin6->sin6_family = AF_INET6;
paddrin6->sin6_port = htons(port);
return true;
}
return false;
}
/**
* @returns An identifier unique to this service's address and port number.
*/
std::vector<unsigned char> CService::GetKey() const
{
std::vector<unsigned char> vKey;
vKey.resize(18);
memcpy(vKey.data(), ip, 16);
vKey[16] = port / 0x100; // most significant byte of our port
vKey[17] = port & 0x0FF; // least significant byte of our port
return vKey;
}
std::string CService::ToStringPort() const
{
return strprintf("%u", port);
}
std::string CService::ToStringIPPort() const
{
if (IsIPv4() || IsTor() || IsInternal()) {
return ToStringIP() + ":" + ToStringPort();
} else {
return "[" + ToStringIP() + "]:" + ToStringPort();
}
}
std::string CService::ToString() const
{
return ToStringIPPort();
}
CSubNet::CSubNet():
valid(false)
{
memset(netmask, 0, sizeof(netmask));
}
CSubNet::CSubNet(const CNetAddr &addr, int32_t mask)
{
valid = true;
network = addr;
// Default to /32 (IPv4) or /128 (IPv6), i.e. match single address
memset(netmask, 255, sizeof(netmask));
// IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
const int astartofs = network.IsIPv4() ? 12 : 0;
int32_t n = mask;
if(n >= 0 && n <= (128 - astartofs*8)) // Only valid if in range of bits of address
{
n += astartofs*8;
// Clear bits [n..127]
for (; n < 128; ++n)
netmask[n>>3] &= ~(1<<(7-(n&7)));
} else
valid = false;
// Normalize network according to netmask
for(int x=0; x<16; ++x)
network.ip[x] &= netmask[x];
}
CSubNet::CSubNet(const CNetAddr &addr, const CNetAddr &mask)
{
valid = true;
network = addr;
// Default to /32 (IPv4) or /128 (IPv6), i.e. match single address
memset(netmask, 255, sizeof(netmask));
// IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
const int astartofs = network.IsIPv4() ? 12 : 0;
for(int x=astartofs; x<16; ++x)
netmask[x] = mask.ip[x];
// Normalize network according to netmask
for(int x=0; x<16; ++x)
network.ip[x] &= netmask[x];
}
CSubNet::CSubNet(const CNetAddr &addr):
valid(addr.IsValid())
{
memset(netmask, 255, sizeof(netmask));
network = addr;
}
/**
* @returns True if this subnet is valid, the specified address is valid, and
* the specified address belongs in this subnet.
*/
bool CSubNet::Match(const CNetAddr &addr) const
{
if (!valid || !addr.IsValid())
return false;
for(int x=0; x<16; ++x)
if ((addr.ip[x] & netmask[x]) != network.ip[x])
return false;
return true;
}
/**
* @returns The number of 1-bits in the prefix of the specified subnet mask. If
* the specified subnet mask is not a valid one, -1.
*/
static inline int NetmaskBits(uint8_t x)
{
switch(x) {
case 0x00: return 0;
case 0x80: return 1;
case 0xc0: return 2;
case 0xe0: return 3;
case 0xf0: return 4;
case 0xf8: return 5;
case 0xfc: return 6;
case 0xfe: return 7;
case 0xff: return 8;
default: return -1;
}
}
std::string CSubNet::ToString() const
{
/* Parse binary 1{n}0{N-n} to see if mask can be represented as /n */
int cidr = 0;
bool valid_cidr = true;
int n = network.IsIPv4() ? 12 : 0;
for (; n < 16 && netmask[n] == 0xff; ++n)
cidr += 8;
if (n < 16) {
int bits = NetmaskBits(netmask[n]);
if (bits < 0)
valid_cidr = false;
else
cidr += bits;
++n;
}
for (; n < 16 && valid_cidr; ++n)
if (netmask[n] != 0x00)
valid_cidr = false;
/* Format output */
std::string strNetmask;
if (valid_cidr) {
strNetmask = strprintf("%u", cidr);
} else {
if (network.IsIPv4())
strNetmask = strprintf("%u.%u.%u.%u", netmask[12], netmask[13], netmask[14], netmask[15]);
else
strNetmask = strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
netmask[0] << 8 | netmask[1], netmask[2] << 8 | netmask[3],
netmask[4] << 8 | netmask[5], netmask[6] << 8 | netmask[7],
netmask[8] << 8 | netmask[9], netmask[10] << 8 | netmask[11],
netmask[12] << 8 | netmask[13], netmask[14] << 8 | netmask[15]);
}
return network.ToString() + "/" + strNetmask;
}
bool CSubNet::IsValid() const
{
return valid;
}
bool operator==(const CSubNet& a, const CSubNet& b)
{
return a.valid == b.valid && a.network == b.network && !memcmp(a.netmask, b.netmask, 16);
}
bool operator<(const CSubNet& a, const CSubNet& b)
{
return (a.network < b.network || (a.network == b.network && memcmp(a.netmask, b.netmask, 16) < 0));
}