// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#ifndef BITCOIN_NETADDRESS_H
#define BITCOIN_NETADDRESS_H
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <compat/compat.h>
#include <crypto/siphash.h>
#include <prevector.h>
#include <random.h>
#include <serialize.h>
#include <tinyformat.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <array>
#include <cstdint>
#include <ios>
#include <string>
#include <vector>
/**
* A flag that is ORed into the protocol version to designate that addresses
* should be serialized in (unserialized from) v2 format (BIP155).
* Make sure that this does not collide with any of the values in `version.h`
* or with `SERIALIZE_TRANSACTION_NO_WITNESS`.
*/
static constexpr int ADDRV2_FORMAT = 0x20000000;
/**
* A network type.
* @note An address may belong to more than one network, for example `10.0.0.1`
* belongs to both `NET_UNROUTABLE` and `NET_IPV4`.
* Keep these sequential starting from 0 and `NET_MAX` as the last entry.
* We have loops like `for (int i = 0; i < NET_MAX; ++i)` that expect to iterate
* over all enum values and also `GetExtNetwork()` "extends" this enum by
* introducing standalone constants starting from `NET_MAX`.
*/
enum Network {
/// Addresses from these networks are not publicly routable on the global Internet.
NET_UNROUTABLE = 0,
/// IPv4
NET_IPV4,
/// IPv6
NET_IPV6,
/// TOR (v2 or v3)
NET_ONION,
/// I2P
NET_I2P,
/// CJDNS
NET_CJDNS,
/// A set of addresses that represent the hash of a string or FQDN. We use
/// them in AddrMan to keep track of which DNS seeds were used.
NET_INTERNAL,
/// Dummy value to indicate the number of NET_* constants.
NET_MAX,
};
/// Prefix of an IPv6 address when it contains an embedded IPv4 address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
static const std::array<uint8_t, 12> IPV4_IN_IPV6_PREFIX{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF};
/// Prefix of an IPv6 address when it contains an embedded TORv2 address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they
/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses.
static const std::array<uint8_t, 6> TORV2_IN_IPV6_PREFIX{
0xFD, 0x87, 0xD8, 0x7E, 0xEB, 0x43};
/// Prefix of an IPv6 address when it contains an embedded "internal" address.
/// Used when (un)serializing addresses in ADDRv1 format (pre-BIP155).
/// The prefix comes from 0xFD + SHA256("bitcoin")[0:5].
/// Such dummy IPv6 addresses are guaranteed to not be publicly routable as they
/// fall under RFC4193's fc00::/7 subnet allocated to unique-local addresses.
static const std::array<uint8_t, 6> INTERNAL_IN_IPV6_PREFIX{
0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 // 0xFD + sha256("bitcoin")[0:5].
};
/// Size of IPv4 address (in bytes).
static constexpr size_t ADDR_IPV4_SIZE = 4;
/// Size of IPv6 address (in bytes).
static constexpr size_t ADDR_IPV6_SIZE = 16;
/// Size of TORv3 address (in bytes). This is the length of just the address
/// as used in BIP155, without the checksum and the version byte.
static constexpr size_t ADDR_TORV3_SIZE = 32;
/// Size of I2P address (in bytes).
static constexpr size_t ADDR_I2P_SIZE = 32;
/// Size of CJDNS address (in bytes).
static constexpr size_t ADDR_CJDNS_SIZE = 16;
/// Size of "internal" (NET_INTERNAL) address (in bytes).
static constexpr size_t ADDR_INTERNAL_SIZE = 10;
/// SAM 3.1 and earlier do not support specifying ports and force the port to 0.
static constexpr uint16_t I2P_SAM31_PORT{0};
std::string OnionToString(Span<const uint8_t> addr);
/**
* Network address.
*/
class CNetAddr
{
protected:
/**
* Raw representation of the network address.
* In network byte order (big endian) for IPv4 and IPv6.
*/
prevector<ADDR_IPV6_SIZE, uint8_t> m_addr{ADDR_IPV6_SIZE, 0x0};
/**
* Network to which this address belongs.
*/
Network m_net{NET_IPV6};
/**
* Scope id if scoped/link-local IPV6 address.
* See https://tools.ietf.org/html/rfc4007
*/
uint32_t m_scope_id{0};
public:
CNetAddr();
explicit CNetAddr(const struct in_addr& ipv4Addr);
void SetIP(const CNetAddr& ip);
/**
* Set from a legacy IPv6 address.
* Legacy IPv6 address may be a normal IPv6 address, or another address
* (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy
* `addr` encoding.
*/
void SetLegacyIPv6(Span<const uint8_t> ipv6);
bool SetInternal(const std::string& name);
/**
* Parse a Tor or I2P address and set this object to it.
* @param[in] addr Address to parse, for example
* pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion or
* ukeu3k5oycgaauneqgtnvselmt4yemvoilkln7jpvamvfx7dnkdq.b32.i2p.
* @returns Whether the operation was successful.
* @see CNetAddr::IsTor(), CNetAddr::IsI2P()
*/
bool SetSpecial(const std::string& addr);
bool IsBindAny() const; // INADDR_ANY equivalent
bool IsIPv4() const; // IPv4 mapped address (::FFFF:0:0/96, 0.0.0.0/0)
bool IsIPv6() const; // IPv6 address (not mapped IPv4, not Tor)
bool IsRFC1918() const; // IPv4 private networks (10.0.0.0/8, 192.168.0.0/16, 172.16.0.0/12)
bool IsRFC2544() const; // IPv4 inter-network communications (198.18.0.0/15)
bool IsRFC6598() const; // IPv4 ISP-level NAT (100.64.0.0/10)
bool IsRFC5737() const; // IPv4 documentation addresses (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24)
bool IsRFC3849() const; // IPv6 documentation address (2001:0DB8::/32)
bool IsRFC3927() const; // IPv4 autoconfig (169.254.0.0/16)
bool IsRFC3964() const; // IPv6 6to4 tunnelling (2002::/16)
bool IsRFC4193() const; // IPv6 unique local (FC00::/7)
bool IsRFC4380() const; // IPv6 Teredo tunnelling (2001::/32)
bool IsRFC4843() const; // IPv6 ORCHID (deprecated) (2001:10::/28)
bool IsRFC7343() const; // IPv6 ORCHIDv2 (2001:20::/28)
bool IsRFC4862() const; // IPv6 autoconfig (FE80::/64)
bool IsRFC6052() const; // IPv6 well-known prefix for IPv4-embedded address (64:FF9B::/96)
bool IsRFC6145() const; // IPv6 IPv4-translated address (::FFFF:0:0:0/96) (actually defined in RFC2765)
bool IsHeNet() const; // IPv6 Hurricane Electric - https://he.net (2001:0470::/36)
bool IsTor() const;
bool IsI2P() const;
bool IsCJDNS() const;
bool IsLocal() const;
bool IsRoutable() const;
bool IsInternal() const;
bool IsValid() const;
/**
* Check if the current object can be serialized in pre-ADDRv2/BIP155 format.
*/
bool IsAddrV1Compatible() const;
enum Network GetNetwork() const;
std::string ToStringAddr() const;
bool GetInAddr(struct in_addr* pipv4Addr) const;
Network GetNetClass() const;
//! For IPv4, mapped IPv4, SIIT translated IPv4, Teredo, 6to4 tunneled addresses, return the relevant IPv4 address as a uint32.
uint32_t GetLinkedIPv4() const;
//! Whether this address has a linked IPv4 address (see GetLinkedIPv4()).
bool HasLinkedIPv4() const;
std::vector<unsigned char> GetAddrBytes() const;
int GetReachabilityFrom(const CNetAddr& paddrPartner) const;
explicit CNetAddr(const struct in6_addr& pipv6Addr, const uint32_t scope = 0);
bool GetIn6Addr(struct in6_addr* pipv6Addr) const;
friend bool operator==(const CNetAddr& a, const CNetAddr& b);
friend bool operator!=(const CNetAddr& a, const CNetAddr& b) { return !(a == b); }
friend bool operator<(const CNetAddr& a, const CNetAddr& b);
/**
* Whether this address should be relayed to other peers even if we can't reach it ourselves.
*/
bool IsRelayable() const
{
return IsIPv4() || IsIPv6() || IsTor() || IsI2P() || IsCJDNS();
}
/**
* Serialize to a stream.
*/
template <typename Stream>
void Serialize(Stream& s) const
{
if (s.GetVersion() & ADDRV2_FORMAT) {
SerializeV2Stream(s);
} else {
SerializeV1Stream(s);
}
}
/**
* Unserialize from a stream.
*/
template <typename Stream>
void Unserialize(Stream& s)
{
if (s.GetVersion() & ADDRV2_FORMAT) {
UnserializeV2Stream(s);
} else {
UnserializeV1Stream(s);
}
}
friend class CSubNet;
private:
/**
* Parse a Tor address and set this object to it.
* @param[in] addr Address to parse, must be a valid C string, for example
* pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion.
* @returns Whether the operation was successful.
* @see CNetAddr::IsTor()
*/
bool SetTor(const std::string& addr);
/**
* Parse an I2P address and set this object to it.
* @param[in] addr Address to parse, must be a valid C string, for example
* ukeu3k5oycgaauneqgtnvselmt4yemvoilkln7jpvamvfx7dnkdq.b32.i2p.
* @returns Whether the operation was successful.
* @see CNetAddr::IsI2P()
*/
bool SetI2P(const std::string& addr);
/**
* BIP155 network ids recognized by this software.
*/
enum BIP155Network : uint8_t {
IPV4 = 1,
IPV6 = 2,
TORV2 = 3,
TORV3 = 4,
I2P = 5,
CJDNS = 6,
};
/**
* Size of CNetAddr when serialized as ADDRv1 (pre-BIP155) (in bytes).
*/
static constexpr size_t V1_SERIALIZATION_SIZE = ADDR_IPV6_SIZE;
/**
* Maximum size of an address as defined in BIP155 (in bytes).
* This is only the size of the address, not the entire CNetAddr object
* when serialized.
*/
static constexpr size_t MAX_ADDRV2_SIZE = 512;
/**
* Get the BIP155 network id of this address.
* Must not be called for IsInternal() objects.
* @returns BIP155 network id, except TORV2 which is no longer supported.
*/
BIP155Network GetBIP155Network() const;
/**
* Set `m_net` from the provided BIP155 network id and size after validation.
* @retval true the network was recognized, is valid and `m_net` was set
* @retval false not recognised (from future?) and should be silently ignored
* @throws std::ios_base::failure if the network is one of the BIP155 founding
* networks (id 1..6) with wrong address size.
*/
bool SetNetFromBIP155Network(uint8_t possible_bip155_net, size_t address_size);
/**
* Serialize in pre-ADDRv2/BIP155 format to an array.
*/
void SerializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE]) const
{
size_t prefix_size;
switch (m_net) {
case NET_IPV6:
assert(m_addr.size() == sizeof(arr));
memcpy(arr, m_addr.data(), m_addr.size());
return;
case NET_IPV4:
prefix_size = sizeof(IPV4_IN_IPV6_PREFIX);
assert(prefix_size + m_addr.size() == sizeof(arr));
memcpy(arr, IPV4_IN_IPV6_PREFIX.data(), prefix_size);
memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
return;
case NET_INTERNAL:
prefix_size = sizeof(INTERNAL_IN_IPV6_PREFIX);
assert(prefix_size + m_addr.size() == sizeof(arr));
memcpy(arr, INTERNAL_IN_IPV6_PREFIX.data(), prefix_size);
memcpy(arr + prefix_size, m_addr.data(), m_addr.size());
return;
case NET_ONION:
case NET_I2P:
case NET_CJDNS:
break;
case NET_UNROUTABLE:
case NET_MAX:
assert(false);
} // no default case, so the compiler can warn about missing cases
// Serialize ONION, I2P and CJDNS as all-zeros.
memset(arr, 0x0, V1_SERIALIZATION_SIZE);
}
/**
* Serialize in pre-ADDRv2/BIP155 format to a stream.
*/
template <typename Stream>
void SerializeV1Stream(Stream& s) const
{
uint8_t serialized[V1_SERIALIZATION_SIZE];
SerializeV1Array(serialized);
s << serialized;
}
/**
* Serialize as ADDRv2 / BIP155.
*/
template <typename Stream>
void SerializeV2Stream(Stream& s) const
{
if (IsInternal()) {
// Serialize NET_INTERNAL as embedded in IPv6. We need to
// serialize such addresses from addrman.
s << static_cast<uint8_t>(BIP155Network::IPV6);
s << COMPACTSIZE(ADDR_IPV6_SIZE);
SerializeV1Stream(s);
return;
}
s << static_cast<uint8_t>(GetBIP155Network());
s << m_addr;
}
/**
* Unserialize from a pre-ADDRv2/BIP155 format from an array.
*
* This function is only called from UnserializeV1Stream() and is a wrapper
* for SetLegacyIPv6(); however, we keep it for symmetry with
* SerializeV1Array() to have pairs of ser/unser functions and to make clear
* that if one is altered, a corresponding reverse modification should be
* applied to the other.
*/
void UnserializeV1Array(uint8_t (&arr)[V1_SERIALIZATION_SIZE])
{
// Use SetLegacyIPv6() so that m_net is set correctly. For example
// ::FFFF:0102:0304 should be set as m_net=NET_IPV4 (1.2.3.4).
SetLegacyIPv6(arr);
}
/**
* Unserialize from a pre-ADDRv2/BIP155 format from a stream.
*/
template <typename Stream>
void UnserializeV1Stream(Stream& s)
{
uint8_t serialized[V1_SERIALIZATION_SIZE];
s >> serialized;
UnserializeV1Array(serialized);
}
/**
* Unserialize from a ADDRv2 / BIP155 format.
*/
template <typename Stream>
void UnserializeV2Stream(Stream& s)
{
uint8_t bip155_net;
s >> bip155_net;
size_t address_size;
s >> COMPACTSIZE(address_size);
if (address_size > MAX_ADDRV2_SIZE) {
throw std::ios_base::failure(strprintf(
"Address too long: %u > %u", address_size, MAX_ADDRV2_SIZE));
}
m_scope_id = 0;
if (SetNetFromBIP155Network(bip155_net, address_size)) {
m_addr.resize(address_size);
s >> Span{m_addr};
if (m_net != NET_IPV6) {
return;
}
// Do some special checks on IPv6 addresses.
// Recognize NET_INTERNAL embedded in IPv6, such addresses are not
// gossiped but could be coming from addrman, when unserializing from
// disk.
if (HasPrefix(m_addr, INTERNAL_IN_IPV6_PREFIX)) {
m_net = NET_INTERNAL;
memmove(m_addr.data(), m_addr.data() + INTERNAL_IN_IPV6_PREFIX.size(),
ADDR_INTERNAL_SIZE);
m_addr.resize(ADDR_INTERNAL_SIZE);
return;
}
if (!HasPrefix(m_addr, IPV4_IN_IPV6_PREFIX) &&
!HasPrefix(m_addr, TORV2_IN_IPV6_PREFIX)) {
return;
}
// IPv4 and TORv2 are not supposed to be embedded in IPv6 (like in V1
// encoding). Unserialize as !IsValid(), thus ignoring them.
} else {
// If we receive an unknown BIP155 network id (from the future?) then
// ignore the address - unserialize as !IsValid().
s.ignore(address_size);
}
// Mimic a default-constructed CNetAddr object which is !IsValid() and thus
// will not be gossiped, but continue reading next addresses from the stream.
m_net = NET_IPV6;
m_addr.assign(ADDR_IPV6_SIZE, 0x0);
}
};
class CSubNet
{
protected:
/// Network (base) address
CNetAddr network;
/// Netmask, in network byte order
uint8_t netmask[16];
/// Is this value valid? (only used to signal parse errors)
bool valid;
public:
/**
* Construct an invalid subnet (empty, `Match()` always returns false).
*/
CSubNet();
/**
* Construct from a given network start and number of bits (CIDR mask).
* @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is
* created.
* @param[in] mask CIDR mask, must be in [0, 32] for IPv4 addresses and in [0, 128] for
* IPv6 addresses. Otherwise an invalid subnet is created.
*/
CSubNet(const CNetAddr& addr, uint8_t mask);
/**
* Construct from a given network start and mask.
* @param[in] addr Network start. Must be IPv4 or IPv6, otherwise an invalid subnet is
* created.
* @param[in] mask Network mask, must be of the same type as `addr` and not contain 0-bits
* followed by 1-bits. Otherwise an invalid subnet is created.
*/
CSubNet(const CNetAddr& addr, const CNetAddr& mask);
/**
* Construct a single-host subnet.
* @param[in] addr The sole address to be contained in the subnet, can also be non-IPv[46].
*/
explicit CSubNet(const CNetAddr& addr);
bool Match(const CNetAddr& addr) const;
std::string ToString() const;
bool IsValid() const;
friend bool operator==(const CSubNet& a, const CSubNet& b);
friend bool operator!=(const CSubNet& a, const CSubNet& b) { return !(a == b); }
friend bool operator<(const CSubNet& a, const CSubNet& b);
};
/** A combination of a network address (CNetAddr) and a (TCP) port */
class CService : public CNetAddr
{
protected:
uint16_t port; // host order
public:
CService();
CService(const CNetAddr& ip, uint16_t port);
CService(const struct in_addr& ipv4Addr, uint16_t port);
explicit CService(const struct sockaddr_in& addr);
uint16_t GetPort() const;
bool GetSockAddr(struct sockaddr* paddr, socklen_t* addrlen) const;
bool SetSockAddr(const struct sockaddr* paddr);
friend bool operator==(const CService& a, const CService& b);
friend bool operator!=(const CService& a, const CService& b) { return !(a == b); }
friend bool operator<(const CService& a, const CService& b);
std::vector<unsigned char> GetKey() const;
std::string ToStringAddrPort() const;
CService(const struct in6_addr& ipv6Addr, uint16_t port);
explicit CService(const struct sockaddr_in6& addr);
SERIALIZE_METHODS(CService, obj)
{
READWRITEAS(CNetAddr, obj);
READWRITE(Using<BigEndianFormatter<2>>(obj.port));
}
friend class CServiceHash;
friend CService MaybeFlipIPv6toCJDNS(const CService& service);
};
class CServiceHash
{
public:
CServiceHash()
: m_salt_k0{GetRand<uint64_t>()},
m_salt_k1{GetRand<uint64_t>()}
{
}
CServiceHash(uint64_t salt_k0, uint64_t salt_k1) : m_salt_k0{salt_k0}, m_salt_k1{salt_k1} {}
size_t operator()(const CService& a) const noexcept
{
CSipHasher hasher(m_salt_k0, m_salt_k1);
hasher.Write(a.m_net);
hasher.Write(a.port);
hasher.Write(a.m_addr);
return static_cast<size_t>(hasher.Finalize());
}
private:
const uint64_t m_salt_k0;
const uint64_t m_salt_k1;
};
#endif // BITCOIN_NETADDRESS_H