Merge #19628: change CNetAddr::ip to have flexible size

This commit is contained in:
Kittywhiskers Van Gogh 2020-08-24 21:03:31 +02:00
parent b76e7fec1f
commit 337c15ae25
7 changed files with 510 additions and 247 deletions

View File

@ -10,56 +10,87 @@
#include <utilstrencodings.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};
#include <algorithm>
#include <array>
#include <cstdint>
#include <iterator>
#include <tuple>
// 0xFD + sha256("bitcoin")[0:5]
static const unsigned char g_internal_prefix[] = { 0xFD, 0x6B, 0x88, 0xC0, 0x87, 0x24 };
constexpr size_t CNetAddr::V1_SERIALIZATION_SIZE;
bool fAllowPrivateNet = DEFAULT_ALLOWPRIVATENET;
CNetAddr::CNetAddr()
{
memset(ip, 0, sizeof(ip));
}
/**
* Construct an unspecified IPv6 network address (::/128).
*
* @note This address is considered invalid by CNetAddr::IsValid()
*/
CNetAddr::CNetAddr() {}
void CNetAddr::SetIP(const CNetAddr& ipIn)
{
// Size check.
switch (ipIn.m_net) {
case NET_IPV4:
assert(ipIn.m_addr.size() == ADDR_IPV4_SIZE);
break;
case NET_IPV6:
assert(ipIn.m_addr.size() == ADDR_IPV6_SIZE);
break;
case NET_ONION:
assert(ipIn.m_addr.size() == ADDR_TORV2_SIZE);
break;
case NET_INTERNAL:
assert(ipIn.m_addr.size() == ADDR_INTERNAL_SIZE);
break;
case NET_UNROUTABLE:
case NET_MAX:
assert(false);
} // no default case, so the compiler can warn about missing cases
m_net = ipIn.m_net;
memcpy(ip, ipIn.ip, sizeof(ip));
m_addr = ipIn.m_addr;
}
void CNetAddr::SetLegacyIPv6(const uint8_t ipv6[16])
template <typename T1, size_t PREFIX_LEN>
inline bool HasPrefix(const T1& obj, const std::array<uint8_t, PREFIX_LEN>& prefix)
{
if (memcmp(ipv6, pchIPv4, sizeof(pchIPv4)) == 0) {
return obj.size() >= PREFIX_LEN &&
std::equal(std::begin(prefix), std::end(prefix), std::begin(obj));
}
void CNetAddr::SetLegacyIPv6(Span<const uint8_t> ipv6)
{
assert(ipv6.size() == ADDR_IPV6_SIZE);
size_t skip{0};
if (HasPrefix(ipv6, IPV4_IN_IPV6_PREFIX)) {
// IPv4-in-IPv6
m_net = NET_IPV4;
} else if (memcmp(ipv6, pchOnionCat, sizeof(pchOnionCat)) == 0) {
skip = sizeof(IPV4_IN_IPV6_PREFIX);
} else if (HasPrefix(ipv6, TORV2_IN_IPV6_PREFIX)) {
// TORv2-in-IPv6
m_net = NET_ONION;
} else if (memcmp(ipv6, g_internal_prefix, sizeof(g_internal_prefix)) == 0) {
skip = sizeof(TORV2_IN_IPV6_PREFIX);
} else if (HasPrefix(ipv6, INTERNAL_IN_IPV6_PREFIX)) {
// Internal-in-IPv6
m_net = NET_INTERNAL;
skip = sizeof(INTERNAL_IN_IPV6_PREFIX);
} else {
// IPv6
m_net = NET_IPV6;
}
memcpy(ip, ipv6, 16);
}
void CNetAddr::SetRaw(Network network, const uint8_t *ip_in)
{
switch(network)
{
case NET_IPV4:
m_net = NET_IPV4;
memcpy(ip, pchIPv4, 12);
memcpy(ip+12, ip_in, 4);
break;
case NET_IPV6:
SetLegacyIPv6(ip_in);
break;
default:
assert(!"invalid network");
}
m_addr.assign(ipv6.begin() + skip, ipv6.end());
}
/**
* Create an "internal" address that represents a name or FQDN. CAddrMan uses
* these fake addresses to keep track of which DNS seeds were used.
* @returns Whether or not the operation was successful.
* @see NET_INTERNAL, INTERNAL_IN_IPV6_PREFIX, CNetAddr::IsInternal(), CNetAddr::IsRFC4193()
*/
bool CNetAddr::SetInternal(const std::string &name)
{
if (name.empty()) {
@ -68,21 +99,26 @@ bool CNetAddr::SetInternal(const std::string &name)
m_net = NET_INTERNAL;
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));
m_addr.assign(hash, hash + ADDR_INTERNAL_SIZE);
return true;
}
/**
* Parse a TORv2 address and set this object to it.
*
* @returns Whether or not the operation was successful.
*
* @see CNetAddr::IsTor()
*/
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))
if (vchAddr.size() != ADDR_TORV2_SIZE) {
return false;
}
m_net = NET_ONION;
memcpy(ip, pchOnionCat, sizeof(pchOnionCat));
for (unsigned int i=0; i<16-sizeof(pchOnionCat); i++)
ip[i + sizeof(pchOnionCat)] = vchAddr[i];
m_addr.assign(vchAddr.begin(), vchAddr.end());
return true;
}
return false;
@ -90,28 +126,23 @@ bool CNetAddr::SetSpecial(const std::string &strName)
CNetAddr::CNetAddr(const struct in_addr& ipv4Addr)
{
SetRaw(NET_IPV4, (const uint8_t*)&ipv4Addr);
m_net = NET_IPV4;
const uint8_t* ptr = reinterpret_cast<const uint8_t*>(&ipv4Addr);
m_addr.assign(ptr, ptr + ADDR_IPV4_SIZE);
}
CNetAddr::CNetAddr(const struct in6_addr& ipv6Addr, const uint32_t scope)
{
SetRaw(NET_IPV6, (const uint8_t*)&ipv6Addr);
SetLegacyIPv6(Span<const uint8_t>(reinterpret_cast<const uint8_t*>(&ipv6Addr), sizeof(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;
if (!IsIPv4() && !IsIPv6()) {
return false;
}
return true;
return std::all_of(m_addr.begin(), m_addr.end(), [](uint8_t b) { return b == 0; });
}
bool CNetAddr::IsIPv4() const { return m_net == NET_IPV4; }
@ -121,102 +152,104 @@ bool CNetAddr::IsIPv6() const { return m_net == NET_IPV6; }
bool CNetAddr::IsRFC1918() const
{
return IsIPv4() && (
GetByte(3) == 10 ||
(GetByte(3) == 192 && GetByte(2) == 168) ||
(GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31)));
m_addr[0] == 10 ||
(m_addr[0] == 192 && m_addr[1] == 168) ||
(m_addr[0] == 172 && m_addr[1] >= 16 && m_addr[1] <= 31));
}
bool CNetAddr::IsRFC2544() const
{
return IsIPv4() && GetByte(3) == 198 && (GetByte(2) == 18 || GetByte(2) == 19);
return IsIPv4() && m_addr[0] == 198 && (m_addr[1] == 18 || m_addr[1] == 19);
}
bool CNetAddr::IsRFC3927() const
{
return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254);
return IsIPv4() && HasPrefix(m_addr, std::array<uint8_t, 2>{169, 254});
}
bool CNetAddr::IsRFC6598() const
{
return IsIPv4() && GetByte(3) == 100 && GetByte(2) >= 64 && GetByte(2) <= 127;
return IsIPv4() && m_addr[0] == 100 && m_addr[1] >= 64 && m_addr[1] <= 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));
return IsIPv4() && (HasPrefix(m_addr, std::array<uint8_t, 3>{192, 0, 2}) ||
HasPrefix(m_addr, std::array<uint8_t, 3>{198, 51, 100}) ||
HasPrefix(m_addr, std::array<uint8_t, 3>{203, 0, 113}));
}
bool CNetAddr::IsRFC3849() const
{
return IsIPv6() && GetByte(15) == 0x20 && GetByte(14) == 0x01 &&
GetByte(13) == 0x0D && GetByte(12) == 0xB8;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x0D, 0xB8});
}
bool CNetAddr::IsRFC3964() const
{
return IsIPv6() && GetByte(15) == 0x20 && GetByte(14) == 0x02;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 2>{0x20, 0x02});
}
bool CNetAddr::IsRFC6052() const
{
static const unsigned char pchRFC6052[] = {0,0x64,0xFF,0x9B,0,0,0,0,0,0,0,0};
return IsIPv6() && memcmp(ip, pchRFC6052, sizeof(pchRFC6052)) == 0;
return IsIPv6() &&
HasPrefix(m_addr, std::array<uint8_t, 12>{0x00, 0x64, 0xFF, 0x9B, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
}
bool CNetAddr::IsRFC4380() const
{
return IsIPv6() && GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0 &&
GetByte(12) == 0;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x00, 0x00});
}
bool CNetAddr::IsRFC4862() const
{
static const unsigned char pchRFC4862[] = {0xFE,0x80,0,0,0,0,0,0};
return IsIPv6() && memcmp(ip, pchRFC4862, sizeof(pchRFC4862)) == 0;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 8>{0xFE, 0x80, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00});
}
bool CNetAddr::IsRFC4193() const
{
return IsIPv6() && (GetByte(15) & 0xFE) == 0xFC;
return IsIPv6() && (m_addr[0] & 0xFE) == 0xFC;
}
bool CNetAddr::IsRFC6145() const
{
static const unsigned char pchRFC6145[] = {0,0,0,0,0,0,0,0,0xFF,0xFF,0,0};
return IsIPv6() && memcmp(ip, pchRFC6145, sizeof(pchRFC6145)) == 0;
return IsIPv6() &&
HasPrefix(m_addr, std::array<uint8_t, 12>{0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00});
}
bool CNetAddr::IsRFC4843() const
{
return IsIPv6() && GetByte(15) == 0x20 && GetByte(14) == 0x01 &&
GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x10;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 3>{0x20, 0x01, 0x00}) &&
(m_addr[3] & 0xF0) == 0x10;
}
bool CNetAddr::IsRFC7343() const
{
return IsIPv6() && GetByte(15) == 0x20 && GetByte(14) == 0x01 &&
GetByte(13) == 0x00 && (GetByte(12) & 0xF0) == 0x20;
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 3>{0x20, 0x01, 0x00}) &&
(m_addr[3] & 0xF0) == 0x20;
}
bool CNetAddr::IsTor() const { return m_net == NET_ONION; }
bool CNetAddr::IsHeNet() const
{
return (GetByte(15) == 0x20 && GetByte(14) == 0x01 && GetByte(13) == 0x04 && GetByte(12) == 0x70);
return IsIPv6() && HasPrefix(m_addr, std::array<uint8_t, 4>{0x20, 0x01, 0x04, 0x70});
}
bool CNetAddr::IsLocal() const
{
// IPv4 loopback
if (IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0))
return true;
// IPv4 loopback (127.0.0.0/8 or 0.0.0.0/8)
if (IsIPv4() && (m_addr[0] == 127 || m_addr[0] == 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 (IsIPv6() && memcmp(ip, pchLocal, 16) == 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 (IsIPv6() && memcmp(m_addr.data(), pchLocal, sizeof(pchLocal)) == 0) {
return true;
}
return false;
}
@ -229,13 +262,16 @@ bool CNetAddr::IsValid() const
// 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 (IsIPv6() && memcmp(ip, pchIPv4+3, sizeof(pchIPv4)-3) == 0)
if (IsIPv6() && memcmp(m_addr.data(), IPV4_IN_IPV6_PREFIX.data() + 3,
sizeof(IPV4_IN_IPV6_PREFIX) - 3) == 0) {
return false;
}
// unspecified IPv6 address (::/128)
unsigned char ipNone6[16] = {};
if (IsIPv6() && memcmp(ip, ipNone6, 16) == 0)
if (IsIPv6() && memcmp(m_addr.data(), ipNone6, sizeof(ipNone6)) == 0) {
return false;
}
// documentation IPv6 address
if (IsRFC3849())
@ -244,17 +280,11 @@ bool CNetAddr::IsValid() const
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)
if (IsIPv4()) {
const uint32_t addr = ReadBE32(m_addr.data());
if (addr == INADDR_ANY || addr == INADDR_NONE) {
return false;
}
}
return true;
@ -269,6 +299,11 @@ bool CNetAddr::IsRoutable() const
return !(IsRFC2544() || IsRFC3927() || IsRFC4862() || IsRFC6598() || IsRFC5737() || (IsRFC4193() && !IsTor()) || IsRFC4843() || IsRFC7343() || IsLocal() || IsInternal());
}
/**
* @returns Whether or not this is a dummy address that represents a name.
*
* @see CNetAddr::SetInternal(const std::string &)
*/
bool CNetAddr::IsInternal() const
{
return m_net == NET_INTERNAL;
@ -288,9 +323,9 @@ enum Network CNetAddr::GetNetwork() const
std::string CNetAddr::ToStringIP(bool fUseGetnameinfo) const
{
if (IsTor())
return EncodeBase32(&ip[6], 10) + ".onion";
return EncodeBase32(m_addr.data(), m_addr.size()) + ".onion";
if (IsInternal())
return EncodeBase32(ip + sizeof(g_internal_prefix), sizeof(ip) - sizeof(g_internal_prefix)) + ".internal";
return EncodeBase32(m_addr.data(), m_addr.size()) + ".internal";
if (fUseGetnameinfo)
{
CService serv(*this, 0);
@ -298,18 +333,19 @@ std::string CNetAddr::ToStringIP(bool fUseGetnameinfo) const
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))
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));
return strprintf("%u.%u.%u.%u", m_addr[0], m_addr[1], m_addr[2], m_addr[3]);
assert(IsIPv6());
return strprintf("%x:%x:%x:%x:%x:%x:%x:%x",
m_addr[0] << 8 | m_addr[1], m_addr[2] << 8 | m_addr[3],
m_addr[4] << 8 | m_addr[5], m_addr[6] << 8 | m_addr[7],
m_addr[8] << 8 | m_addr[9], m_addr[10] << 8 | m_addr[11],
m_addr[12] << 8 | m_addr[13], m_addr[14] << 8 | m_addr[15]);
}
std::string CNetAddr::ToString() const
@ -319,19 +355,20 @@ std::string CNetAddr::ToString() const
bool operator==(const CNetAddr& a, const CNetAddr& b)
{
return a.m_net == b.m_net && memcmp(a.ip, b.ip, 16) == 0;
return a.m_net == b.m_net && a.m_addr == b.m_addr;
}
bool operator<(const CNetAddr& a, const CNetAddr& b)
{
return a.m_net < b.m_net || (a.m_net == b.m_net && memcmp(a.ip, b.ip, 16) < 0);
return std::tie(a.m_net, a.m_addr) < std::tie(b.m_net, b.m_addr);
}
bool CNetAddr::GetInAddr(struct in_addr* pipv4Addr) const
{
if (!IsIPv4())
return false;
memcpy(pipv4Addr, ip+12, 4);
assert(sizeof(*pipv4Addr) == m_addr.size());
memcpy(pipv4Addr, m_addr.data(), m_addr.size());
return true;
}
@ -340,7 +377,8 @@ bool CNetAddr::GetIn6Addr(struct in6_addr* pipv6Addr) const
if (!IsIPv6()) {
return false;
}
memcpy(pipv6Addr, ip, 16);
assert(sizeof(*pipv6Addr) == m_addr.size());
memcpy(pipv6Addr, m_addr.data(), m_addr.size());
return true;
}
@ -351,15 +389,17 @@ bool CNetAddr::HasLinkedIPv4() const
uint32_t CNetAddr::GetLinkedIPv4() const
{
if (IsIPv4() || IsRFC6145() || IsRFC6052()) {
// IPv4, mapped IPv4, SIIT translated IPv4: the IPv4 address is the last 4 bytes of the address
return ReadBE32(ip + 12);
if (IsIPv4()) {
return ReadBE32(m_addr.data());
} else if (IsRFC6052() || IsRFC6145()) {
// mapped IPv4, SIIT translated IPv4: the IPv4 address is the last 4 bytes of the address
return ReadBE32(MakeSpan(m_addr).last(ADDR_IPV4_SIZE).data());
} else if (IsRFC3964()) {
// 6to4 tunneled IPv4: the IPv4 address is in bytes 2-6
return ReadBE32(ip + 2);
return ReadBE32(MakeSpan(m_addr).subspan(2, ADDR_IPV4_SIZE).data());
} else if (IsRFC4380()) {
// Teredo tunneled IPv4: the IPv4 address is in the last 4 bytes of the address, but bitflipped
return ~ReadBE32(ip + 12);
return ~ReadBE32(MakeSpan(m_addr).last(ADDR_IPV4_SIZE).data());
}
assert(false);
}
@ -388,10 +428,10 @@ uint32_t CNetAddr::GetMappedAS(const std::vector<bool> &asmap) const {
}
std::vector<bool> ip_bits(128);
if (HasLinkedIPv4()) {
// For lookup, treat as if it was just an IPv4 address (pchIPv4 prefix + IPv4 bits)
// For lookup, treat as if it was just an IPv4 address (IPV4_IN_IPV6_PREFIX + IPv4 bits)
for (int8_t byte_i = 0; byte_i < 12; ++byte_i) {
for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) {
ip_bits[byte_i * 8 + bit_i] = (pchIPv4[byte_i] >> (7 - bit_i)) & 1;
ip_bits[byte_i * 8 + bit_i] = (IPV4_IN_IPV6_PREFIX[byte_i] >> (7 - bit_i)) & 1;
}
}
uint32_t ipv4 = GetLinkedIPv4();
@ -400,8 +440,9 @@ uint32_t CNetAddr::GetMappedAS(const std::vector<bool> &asmap) const {
}
} else {
// Use all 128 bits of the IPv6 address otherwise
assert(IsIPv6());
for (int8_t byte_i = 0; byte_i < 16; ++byte_i) {
uint8_t cur_byte = GetByte(15 - byte_i);
uint8_t cur_byte = m_addr[byte_i];
for (uint8_t bit_i = 0; bit_i < 8; ++bit_i) {
ip_bits[byte_i * 8 + bit_i] = (cur_byte >> (7 - bit_i)) & 1;
}
@ -437,19 +478,15 @@ std::vector<unsigned char> CNetAddr::GetGroup(const std::vector<bool> &asmap) co
}
vchRet.push_back(net_class);
int nStartByte = 0;
int nBits = 16;
int nBits{0};
if (IsLocal()) {
// all local addresses belong to the same group
nBits = 0;
} else if (IsInternal()) {
// all internal-usage addresses get their own group
nStartByte = sizeof(g_internal_prefix);
nBits = (sizeof(ip) - sizeof(g_internal_prefix)) * 8;
nBits = ADDR_INTERNAL_SIZE * 8;
} else if (!IsRoutable()) {
// all other unroutable addresses belong to the same group
nBits = 0;
} else if (HasLinkedIPv4()) {
// IPv4 addresses (and mapped IPv4 addresses) use /16 groups
uint32_t ipv4 = GetLinkedIPv4();
@ -457,7 +494,6 @@ std::vector<unsigned char> CNetAddr::GetGroup(const std::vector<bool> &asmap) co
vchRet.push_back((ipv4 >> 16) & 0xFF);
return vchRet;
} else if (IsTor()) {
nStartByte = 6;
nBits = 4;
} else if (IsHeNet()) {
// for he.net, use /36 groups
@ -467,21 +503,29 @@ std::vector<unsigned char> CNetAddr::GetGroup(const std::vector<bool> &asmap) co
nBits = 32;
}
while (nBits >= 8)
{
vchRet.push_back(GetByte(15 - nStartByte));
nStartByte++;
nBits -= 8;
// Push our address onto vchRet.
const size_t num_bytes = nBits / 8;
vchRet.insert(vchRet.end(), m_addr.begin(), m_addr.begin() + num_bytes);
nBits %= 8;
// ...for the last byte, push nBits and for the rest of the byte push 1's
if (nBits > 0) {
assert(num_bytes < m_addr.size());
vchRet.push_back(m_addr[num_bytes] | ((1 << (8 - nBits)) - 1));
}
if (nBits > 0)
vchRet.push_back(GetByte(15 - nStartByte) | ((1 << (8 - nBits)) - 1));
return vchRet;
}
std::vector<unsigned char> CNetAddr::GetAddrBytes() const
{
uint8_t serialized[V1_SERIALIZATION_SIZE];
SerializeV1Array(serialized);
return {std::begin(serialized), std::end(serialized)};
}
uint64_t CNetAddr::GetHash() const
{
uint256 hash = Hash(&ip[0], &ip[16]);
uint256 hash = Hash(m_addr);
uint64_t nRet;
memcpy(&nRet, &hash, sizeof(nRet));
return nRet;
@ -682,66 +726,31 @@ CSubNet::CSubNet():
memset(netmask, 0, sizeof(netmask));
}
CSubNet::CSubNet(const CNetAddr &addr, int32_t mask)
CSubNet::CSubNet(const CNetAddr& addr, uint8_t mask) : CSubNet()
{
valid = true;
valid = (addr.IsIPv4() && mask <= ADDR_IPV4_SIZE * 8) ||
(addr.IsIPv6() && mask <= ADDR_IPV6_SIZE * 8);
if (!valid) {
return;
}
assert(mask <= sizeof(netmask) * 8);
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;
}
bool CSubNet::Match(const CNetAddr &addr) const
{
if (!valid || !addr.IsValid() || network.m_net != addr.m_net)
return false;
for(int x=0; x<16; ++x)
if ((addr.ip[x] & netmask[x]) != network.ip[x])
return false;
return true;
uint8_t n = mask;
for (size_t i = 0; i < network.m_addr.size(); ++i) {
const uint8_t bits = n < 8 ? n : 8;
netmask[i] = (uint8_t)((uint8_t)0xFF << (8 - bits)); // Set first bits.
network.m_addr[i] &= netmask[i]; // Normalize network according to netmask.
n -= bits;
}
}
/**
* @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) {
@ -758,42 +767,78 @@ static inline int NetmaskBits(uint8_t x)
}
}
CSubNet::CSubNet(const CNetAddr& addr, const CNetAddr& mask) : CSubNet()
{
valid = (addr.IsIPv4() || addr.IsIPv6()) && addr.m_net == mask.m_net;
if (!valid) {
return;
}
// Check if `mask` contains 1-bits after 0-bits (which is an invalid netmask).
bool zeros_found = false;
for (auto b : mask.m_addr) {
const int num_bits = NetmaskBits(b);
if (num_bits == -1 || (zeros_found && num_bits != 0)) {
valid = false;
return;
}
if (num_bits < 8) {
zeros_found = true;
}
}
assert(mask.m_addr.size() <= sizeof(netmask));
memcpy(netmask, mask.m_addr.data(), mask.m_addr.size());
network = addr;
// Normalize network according to netmask
for (size_t x = 0; x < network.m_addr.size(); ++x) {
network.m_addr[x] &= netmask[x];
}
}
CSubNet::CSubNet(const CNetAddr& addr) : CSubNet()
{
valid = addr.IsIPv4() || addr.IsIPv6();
if (!valid) {
return;
}
assert(addr.m_addr.size() <= sizeof(netmask));
memset(netmask, 0xFF, addr.m_addr.size());
network = addr;
}
bool CSubNet::Match(const CNetAddr &addr) const
{
if (!valid || !addr.IsValid() || network.m_net != addr.m_net)
return false;
assert(network.m_addr.size() == addr.m_addr.size());
for (size_t x = 0; x < addr.m_addr.size(); ++x) {
if ((addr.m_addr[x] & netmask[x]) != network.m_addr[x]) {
return false;
}
}
return true;
}
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;
assert(network.m_addr.size() <= sizeof(netmask));
/* 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]);
uint8_t cidr = 0;
for (size_t i = 0; i < network.m_addr.size(); ++i) {
if (netmask[i] == 0x00) {
break;
}
cidr += NetmaskBits(netmask[i]);
}
return network.ToString() + "/" + strNetmask;
return network.ToString() + strprintf("/%u", cidr);
}
bool CSubNet::IsValid() const

View File

@ -9,11 +9,14 @@
#include <config/dash-config.h>
#endif
#include <attributes.h>
#include <compat.h>
#include <prevector.h>
#include <serialize.h>
#include <span.h>
#include <stdint.h>
#include <array>
#include <cstdint>
#include <string>
#include <vector>
@ -42,28 +45,66 @@ enum Network
/// TORv2
NET_ONION,
/// A set of dummy addresses that map a name to an IPv6 address. These
/// addresses belong to RFC4193's fc00::/7 subnet (unique-local addresses).
/// We use them to map a string or FQDN to an IPv6 address in CAddrMan to
/// keep track of which DNS seeds were used.
/// A set of addresses that represent the hash of a string or FQDN. We use
/// them in CAddrMan 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 TORv2 address (in bytes).
static constexpr size_t ADDR_TORV2_SIZE = 10;
/// Size of "internal" (NET_INTERNAL) address (in bytes).
static constexpr size_t ADDR_INTERNAL_SIZE = 10;
/**
* 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};
unsigned char ip[16]; // in network byte order
uint32_t scopeId{0}; // for scoped/link-local ipv6 addresses
public:
@ -77,7 +118,7 @@ class CNetAddr
* (e.g. IPv4) disguised as IPv6. This encoding is used in the legacy
* `addr` encoding.
*/
void SetLegacyIPv6(const uint8_t ipv6[16]);
void SetLegacyIPv6(Span<const uint8_t> ipv6);
private:
/**
@ -120,7 +161,6 @@ class CNetAddr
enum Network GetNetwork() const;
std::string ToString() const;
std::string ToStringIP(bool fUseGetnameinfo = true) const;
unsigned int GetByte(int n) const;
uint64_t GetHash() const;
bool GetInAddr(struct in_addr* pipv4Addr) const;
uint32_t GetNetClass() const;
@ -135,7 +175,7 @@ class CNetAddr
// The ip->AS mapping depends on how asmap is constructed.
uint32_t GetMappedAS(const std::vector<bool> &asmap) const;
std::vector<unsigned char> GetGroup(const std::vector<bool> &asmap) const;
std::vector<unsigned char> GetAddrBytes() const { return {std::begin(ip), std::end(ip)}; }
std::vector<unsigned char> GetAddrBytes() const;
int GetReachabilityFrom(const CNetAddr *paddrPartner = nullptr) const;
explicit CNetAddr(const struct in6_addr& pipv6Addr, const uint32_t scope = 0);
@ -151,7 +191,7 @@ class CNetAddr
template <typename Stream>
void Serialize(Stream& s) const
{
s << ip;
SerializeV1Stream(s);
}
/**
@ -160,14 +200,93 @@ class CNetAddr
template <typename Stream>
void Unserialize(Stream& s)
{
unsigned char ip_temp[sizeof(ip)];
s >> ip_temp;
// 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(ip_temp);
UnserializeV1Stream(s);
}
friend class CSubNet;
private:
/**
* Size of CNetAddr when serialized as ADDRv1 (pre-BIP155) (in bytes).
*/
static constexpr size_t V1_SERIALIZATION_SIZE = ADDR_IPV6_SIZE;
/**
* Serialize in pre-ADDRv2/BIP155 format to an array.
* Some addresses (e.g. TORv3) cannot be serialized in pre-BIP155 format.
*/
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_ONION:
prefix_size = sizeof(TORV2_IN_IPV6_PREFIX);
assert(prefix_size + m_addr.size() == sizeof(arr));
memcpy(arr, TORV2_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_UNROUTABLE:
case NET_MAX:
assert(false);
} // no default case, so the compiler can warn about missing cases
assert(false);
}
public:
/**
* Serialize in pre-ADDRv2/BIP155 format to a stream.
* Some addresses (e.g. TORv3) cannot be serialized in pre-BIP155 format.
*/
template <typename Stream>
void SerializeV1Stream(Stream& s) const
{
uint8_t serialized[V1_SERIALIZATION_SIZE];
SerializeV1Array(serialized);
s << serialized;
}
/**
* Unserialize from a pre-ADDRv2/BIP155 format from an array.
*/
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);
}
};
class CSubNet
@ -182,11 +301,11 @@ class CSubNet
public:
CSubNet();
CSubNet(const CNetAddr &addr, int32_t mask);
CSubNet(const CNetAddr &addr, const CNetAddr &mask);
CSubNet(const CNetAddr& addr, uint8_t mask);
CSubNet(const CNetAddr& addr, const CNetAddr& mask);
//constructor for single ip subnet (<ipv4>/32 or <ipv6>/128)
explicit CSubNet(const CNetAddr &addr);
explicit CSubNet(const CNetAddr& addr);
bool Match(const CNetAddr &addr) const;
@ -239,7 +358,7 @@ class CService : public CNetAddr
template <typename Stream>
void Serialize(Stream& s) const
{
s << ip;
SerializeV1Stream(s);
s << WrapBigEndian(port);
}
@ -249,11 +368,7 @@ class CService : public CNetAddr
template <typename Stream>
void Unserialize(Stream& s)
{
unsigned char ip_temp[sizeof(ip)];
s >> ip_temp;
// 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(ip_temp);
UnserializeV1Stream(s);
s >> WrapBigEndian(port);
}
};

View File

@ -14,6 +14,8 @@
#include <utilstrencodings.h>
#include <atomic>
#include <cstdint>
#include <limits>
#ifndef WIN32
#include <fcntl.h>
@ -642,9 +644,9 @@ bool LookupSubNet(const char* pszName, CSubNet& ret)
if (slash != strSubnet.npos)
{
std::string strNetmask = strSubnet.substr(slash + 1);
int32_t n;
// IPv4 addresses start at offset 12, and first 12 bytes must match, so just offset n
if (ParseInt32(strNetmask, &n)) { // If valid number, assume /24 syntax
uint8_t n;
if (ParseUInt8(strNetmask, &n)) {
// If valid number, assume CIDR variable-length subnet masking
ret = CSubNet(network, n);
return ret.IsValid();
}

View File

@ -12,6 +12,8 @@
#include <netbase.h>
#include <chainparams.h>
#include <util.h>
#include <utilstrencodings.h>
#include <version.h>
#include <memory>
@ -203,6 +205,78 @@ BOOST_AUTO_TEST_CASE(PoissonNextSend)
g_mock_deterministic_tests = false;
}
BOOST_AUTO_TEST_CASE(cnetaddr_basic)
{
CNetAddr addr;
// IPv4, INADDR_ANY
BOOST_REQUIRE(LookupHost("0.0.0.0", addr, false));
BOOST_REQUIRE(!addr.IsValid());
BOOST_REQUIRE(addr.IsIPv4());
BOOST_CHECK(addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "0.0.0.0");
// IPv4, INADDR_NONE
BOOST_REQUIRE(LookupHost("255.255.255.255", addr, false));
BOOST_REQUIRE(!addr.IsValid());
BOOST_REQUIRE(addr.IsIPv4());
BOOST_CHECK(!addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "255.255.255.255");
// IPv4, casual
BOOST_REQUIRE(LookupHost("12.34.56.78", addr, false));
BOOST_REQUIRE(addr.IsValid());
BOOST_REQUIRE(addr.IsIPv4());
BOOST_CHECK(!addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "12.34.56.78");
// IPv6, in6addr_any
BOOST_REQUIRE(LookupHost("::", addr, false));
BOOST_REQUIRE(!addr.IsValid());
BOOST_REQUIRE(addr.IsIPv6());
BOOST_CHECK(addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "::");
// IPv6, casual
BOOST_REQUIRE(LookupHost("1122:3344:5566:7788:9900:aabb:ccdd:eeff", addr, false));
BOOST_REQUIRE(addr.IsValid());
BOOST_REQUIRE(addr.IsIPv6());
BOOST_CHECK(!addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "1122:3344:5566:7788:9900:aabb:ccdd:eeff");
// TORv2
addr.SetSpecial("6hzph5hv6337r6p2.onion");
BOOST_REQUIRE(addr.IsValid());
BOOST_REQUIRE(addr.IsTor());
BOOST_CHECK(!addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "6hzph5hv6337r6p2.onion");
// Internal
addr.SetInternal("esffpp");
BOOST_REQUIRE(!addr.IsValid()); // "internal" is considered invalid
BOOST_REQUIRE(addr.IsInternal());
BOOST_CHECK(!addr.IsBindAny());
BOOST_CHECK_EQUAL(addr.ToString(), "esffpvrt3wpeaygy.internal");
}
BOOST_AUTO_TEST_CASE(cnetaddr_serialize)
{
CNetAddr addr;
CDataStream s(SER_NETWORK, PROTOCOL_VERSION);
addr.SetInternal("a");
s << addr;
BOOST_CHECK_EQUAL(HexStr(s), "fd6b88c08724ca978112ca1bbdcafac2");
s.clear();
}
// prior to PR #14728, this test triggers an undefined behavior
BOOST_AUTO_TEST_CASE(ipv4_peer_with_ipv6_addrMe_test)
{

View File

@ -183,6 +183,7 @@ BOOST_AUTO_TEST_CASE(subnet_test)
BOOST_CHECK(!ResolveSubNet("1.2.3.0/-1").IsValid());
BOOST_CHECK(ResolveSubNet("1.2.3.0/32").IsValid());
BOOST_CHECK(!ResolveSubNet("1.2.3.0/33").IsValid());
BOOST_CHECK(!ResolveSubNet("1.2.3.0/300").IsValid());
BOOST_CHECK(ResolveSubNet("1:2:3:4:5:6:7:8/0").IsValid());
BOOST_CHECK(ResolveSubNet("1:2:3:4:5:6:7:8/33").IsValid());
BOOST_CHECK(!ResolveSubNet("1:2:3:4:5:6:7:8/-1").IsValid());
@ -214,6 +215,11 @@ BOOST_AUTO_TEST_CASE(subnet_test)
BOOST_CHECK(CSubNet(ResolveIP("1:2:3:4:5:6:7:8")).Match(ResolveIP("1:2:3:4:5:6:7:8")));
BOOST_CHECK(!CSubNet(ResolveIP("1:2:3:4:5:6:7:8")).Match(ResolveIP("1:2:3:4:5:6:7:9")));
BOOST_CHECK(CSubNet(ResolveIP("1:2:3:4:5:6:7:8")).ToString() == "1:2:3:4:5:6:7:8/128");
// IPv4 address with IPv6 netmask or the other way around.
BOOST_CHECK(!CSubNet(ResolveIP("1.1.1.1"), ResolveIP("ffff::")).IsValid());
BOOST_CHECK(!CSubNet(ResolveIP("::1"), ResolveIP("255.0.0.0")).IsValid());
// Can't subnet TOR (or any other non-IPv4 and non-IPv6 network).
BOOST_CHECK(!CSubNet(ResolveIP("5wyqrzbvrdsumnok.onion"), ResolveIP("255.0.0.0")).IsValid());
subnet = ResolveSubNet("1.2.3.4/255.255.255.255");
BOOST_CHECK_EQUAL(subnet.ToString(), "1.2.3.4/32");
@ -288,11 +294,13 @@ BOOST_AUTO_TEST_CASE(subnet_test)
BOOST_CHECK_EQUAL(subnet.ToString(), "1::/16");
subnet = ResolveSubNet("1:2:3:4:5:6:7:8/0000:0000:0000:0000:0000:0000:0000:0000");
BOOST_CHECK_EQUAL(subnet.ToString(), "::/0");
// Invalid netmasks (with 1-bits after 0-bits)
subnet = ResolveSubNet("1.2.3.4/255.255.232.0");
BOOST_CHECK_EQUAL(subnet.ToString(), "1.2.0.0/255.255.232.0");
BOOST_CHECK(!subnet.IsValid());
subnet = ResolveSubNet("1.2.3.4/255.0.255.255");
BOOST_CHECK(!subnet.IsValid());
subnet = ResolveSubNet("1:2:3:4:5:6:7:8/ffff:ffff:ffff:fffe:ffff:ffff:ffff:ff0f");
BOOST_CHECK_EQUAL(subnet.ToString(), "1:2:3:4:5:6:7:8/ffff:ffff:ffff:fffe:ffff:ffff:ffff:ff0f");
BOOST_CHECK(!subnet.IsValid());
}
BOOST_AUTO_TEST_CASE(netbase_getgroup)

View File

@ -303,6 +303,18 @@ bool ParseInt64(const std::string& str, int64_t *out)
n <= std::numeric_limits<int64_t>::max();
}
bool ParseUInt8(const std::string& str, uint8_t *out)
{
uint32_t u32;
if (!ParseUInt32(str, &u32) || u32 > std::numeric_limits<uint8_t>::max()) {
return false;
}
if (out != nullptr) {
*out = static_cast<uint8_t>(u32);
}
return true;
}
bool ParseUInt32(const std::string& str, uint32_t *out)
{
if (!ParsePrechecks(str))

View File

@ -88,6 +88,13 @@ NODISCARD bool ParseInt32(const std::string& str, int32_t *out);
*/
NODISCARD bool ParseInt64(const std::string& str, int64_t *out);
/**
* Convert decimal string to unsigned 8-bit integer with strict parse error feedback.
* @returns true if the entire string could be parsed as valid integer,
* false if not the entire string could be parsed or when overflow or underflow occurred.
*/
NODISCARD bool ParseUInt8(const std::string& str, uint8_t *out);
/**
* Convert decimal string to unsigned 32-bit integer with strict parse error feedback.
* @returns true if the entire string could be parsed as valid integer,