// Copyright (c) 2012 Pieter Wuille
// Copyright (c) 2012-2020 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 <addrman.h>
#include <clientversion.h>
#include <hash.h>
#include <logging.h>
#include <netaddress.h>
#include <serialize.h>
#include <streams.h>
#include <util/check.h>
#include <cmath>
#include <optional>
#include <unordered_map>
#include <unordered_set>
/** Over how many buckets entries with tried addresses from a single group (/16 for IPv4) are spread */
static constexpr uint32_t ADDRMAN_TRIED_BUCKETS_PER_GROUP{8};
/** Over how many buckets entries with new addresses originating from a single group are spread */
static constexpr uint32_t ADDRMAN_NEW_BUCKETS_PER_SOURCE_GROUP{64};
/** Maximum number of times an address can be added to the new table */
static constexpr int32_t ADDRMAN_NEW_BUCKETS_PER_ADDRESS{8};
/** How old addresses can maximally be */
static constexpr int64_t ADDRMAN_HORIZON_DAYS{30};
/** After how many failed attempts we give up on a new node */
static constexpr int32_t ADDRMAN_RETRIES{3};
/** How many successive failures are allowed ... */
static constexpr int32_t ADDRMAN_MAX_FAILURES{10};
/** ... in at least this many days */
static constexpr int64_t ADDRMAN_MIN_FAIL_DAYS{7};
/** How recent a successful connection should be before we allow an address to be evicted from tried */
static constexpr int64_t ADDRMAN_REPLACEMENT_HOURS{4};
/** The maximum number of tried addr collisions to store */
static constexpr size_t ADDRMAN_SET_TRIED_COLLISION_SIZE{10};
/** The maximum time we'll spend trying to resolve a tried table collision, in seconds */
static constexpr int64_t ADDRMAN_TEST_WINDOW{40*60}; // 40 minutes
int CAddrInfo::GetTriedBucket(const uint256& nKey, const std::vector<bool> &asmap) const
{
uint64_t hash1 = (CHashWriter(SER_GETHASH, 0) << nKey << GetKey()).GetCheapHash();
uint64_t hash2 = (CHashWriter(SER_GETHASH, 0) << nKey << GetGroup(asmap) << (hash1 % ADDRMAN_TRIED_BUCKETS_PER_GROUP)).GetCheapHash();
int tried_bucket = hash2 % ADDRMAN_TRIED_BUCKET_COUNT;
uint32_t mapped_as = GetMappedAS(asmap);
LogPrint(BCLog::NET, "IP %s mapped to AS%i belongs to tried bucket %i\n", ToStringIP(), mapped_as, tried_bucket);
return tried_bucket;
}
int CAddrInfo::GetNewBucket(const uint256& nKey, const CNetAddr& src, const std::vector<bool> &asmap) const
{
std::vector<unsigned char> vchSourceGroupKey = src.GetGroup(asmap);
uint64_t hash1 = (CHashWriter(SER_GETHASH, 0) << nKey << GetGroup(asmap) << vchSourceGroupKey).GetCheapHash();
uint64_t hash2 = (CHashWriter(SER_GETHASH, 0) << nKey << vchSourceGroupKey << (hash1 % ADDRMAN_NEW_BUCKETS_PER_SOURCE_GROUP)).GetCheapHash();
int new_bucket = hash2 % ADDRMAN_NEW_BUCKET_COUNT;
uint32_t mapped_as = GetMappedAS(asmap);
LogPrint(BCLog::NET, "IP %s mapped to AS%i belongs to new bucket %i\n", ToStringIP(), mapped_as, new_bucket);
return new_bucket;
}
int CAddrInfo::GetBucketPosition(const uint256 &nKey, bool fNew, int nBucket) const
{
uint64_t hash1 = (CHashWriter(SER_GETHASH, 0) << nKey << (fNew ? uint8_t{'N'} : uint8_t{'K'}) << nBucket << GetKey()).GetCheapHash();
return hash1 % ADDRMAN_BUCKET_SIZE;
}
bool CAddrInfo::IsTerrible(int64_t nNow) const
{
if (nLastTry && nLastTry >= nNow - 60) // never remove things tried in the last minute
return false;
if (nTime > nNow + 10 * 60) // came in a flying DeLorean
return true;
if (nTime == 0 || nNow - nTime > ADDRMAN_HORIZON_DAYS * 24 * 60 * 60) // not seen in recent history
return true;
if (nLastSuccess == 0 && nAttempts >= ADDRMAN_RETRIES) // tried N times and never a success
return true;
if (nNow - nLastSuccess > ADDRMAN_MIN_FAIL_DAYS * 24 * 60 * 60 && nAttempts >= ADDRMAN_MAX_FAILURES) // N successive failures in the last week
return true;
return false;
}
double CAddrInfo::GetChance(int64_t nNow) const
{
double fChance = 1.0;
int64_t nSinceLastTry = std::max<int64_t>(nNow - nLastTry, 0);
// deprioritize very recent attempts away
if (nSinceLastTry < 60 * 10)
fChance *= 0.01;
// deprioritize 66% after each failed attempt, but at most 1/28th to avoid the search taking forever or overly penalizing outages.
fChance *= pow(0.66, std::min(nAttempts, 8));
return fChance;
}
CAddrMan::CAddrMan(std::vector<bool> asmap, bool deterministic, int32_t consistency_check_ratio)
: insecure_rand{deterministic}
, nKey{deterministic ? uint256{1} : insecure_rand.rand256()}
, m_consistency_check_ratio{consistency_check_ratio}
, m_asmap{std::move(asmap)}
{
for (auto& bucket : vvNew) {
for (auto& entry : bucket) {
entry = -1;
}
}
for (auto& bucket : vvTried) {
for (auto& entry : bucket) {
entry = -1;
}
}
}
template <typename Stream>
void CAddrMan::Serialize(Stream& s_) const
{
LOCK(cs);
/**
* Serialized format.
* * format version byte (@see `Format`)
* * lowest compatible format version byte. This is used to help old software decide
* whether to parse the file. For example:
* * Bitcoin Core version N knows how to parse up to format=3. If a new format=4 is
* introduced in version N+1 that is compatible with format=3 and it is known that
* version N will be able to parse it, then version N+1 will write
* (format=4, lowest_compatible=3) in the first two bytes of the file, and so
* version N will still try to parse it.
* * Bitcoin Core version N+2 introduces a new incompatible format=5. It will write
* (format=5, lowest_compatible=5) and so any versions that do not know how to parse
* format=5 will not try to read the file.
* * nKey
* * nNew
* * nTried
* * number of "new" buckets XOR 2**30
* * all new addresses (total count: nNew)
* * all tried addresses (total count: nTried)
* * for each new bucket:
* * number of elements
* * for each element: index in the serialized "all new addresses"
* * asmap checksum
*
* 2**30 is xorred with the number of buckets to make addrman deserializer v0 detect it
* as incompatible. This is necessary because it did not check the version number on
* deserialization.
*
* vvNew, vvTried, mapInfo, mapAddr and vRandom are never encoded explicitly;
* they are instead reconstructed from the other information.
*
* This format is more complex, but significantly smaller (at most 1.5 MiB), and supports
* changes to the ADDRMAN_ parameters without breaking the on-disk structure.
*
* We don't use SERIALIZE_METHODS since the serialization and deserialization code has
* very little in common.
*/
// Always serialize in the latest version (FILE_FORMAT).
OverrideStream<Stream> s(&s_, s_.GetType(), s_.GetVersion() | ADDRV2_FORMAT);
s << static_cast<uint8_t>(FILE_FORMAT);
// Increment `lowest_compatible` iff a newly introduced format is incompatible with
// the previous one.
static constexpr uint8_t lowest_compatible = Format::V3_BIP155;
s << static_cast<uint8_t>(INCOMPATIBILITY_BASE + lowest_compatible);
s << nKey;
s << nNew;
s << nTried;
int nUBuckets = ADDRMAN_NEW_BUCKET_COUNT ^ (1 << 30);
s << nUBuckets;
std::unordered_map<int, int> mapUnkIds;
int nIds = 0;
for (const auto& entry : mapInfo) {
mapUnkIds[entry.first] = nIds;
const CAddrInfo &info = entry.second;
if (info.nRefCount) {
assert(nIds != nNew); // this means nNew was wrong, oh ow
s << info;
nIds++;
}
}
nIds = 0;
for (const auto& entry : mapInfo) {
const CAddrInfo &info = entry.second;
if (info.fInTried) {
assert(nIds != nTried); // this means nTried was wrong, oh ow
s << info;
nIds++;
}
}
for (int bucket = 0; bucket < ADDRMAN_NEW_BUCKET_COUNT; bucket++) {
int nSize = 0;
for (int i = 0; i < ADDRMAN_BUCKET_SIZE; i++) {
if (vvNew[bucket][i] != -1)
nSize++;
}
s << nSize;
for (int i = 0; i < ADDRMAN_BUCKET_SIZE; i++) {
if (vvNew[bucket][i] != -1) {
int nIndex = mapUnkIds[vvNew[bucket][i]];
s << nIndex;
}
}
}
// Store asmap checksum after bucket entries so that it
// can be ignored by older clients for backward compatibility.
uint256 asmap_checksum;
if (m_asmap.size() != 0) {
asmap_checksum = SerializeHash(m_asmap);
}
s << asmap_checksum;
}
template <typename Stream>
void CAddrMan::Unserialize(Stream& s_)
{
LOCK(cs);
assert(vRandom.empty());
Format format;
s_ >> Using<CustomUintFormatter<1>>(format);
int stream_version = s_.GetVersion();
if (format >= Format::V3_BIP155) {
// Add ADDRV2_FORMAT to the version so that the CNetAddr and CAddress
// unserialize methods know that an address in addrv2 format is coming.
stream_version |= ADDRV2_FORMAT;
}
OverrideStream<Stream> s(&s_, s_.GetType(), stream_version);
uint8_t compat;
s >> compat;
const uint8_t lowest_compatible = compat - INCOMPATIBILITY_BASE;
if (lowest_compatible > FILE_FORMAT) {
throw std::ios_base::failure(strprintf(
"Unsupported format of addrman database: %u. It is compatible with formats >=%u, "
"but the maximum supported by this version of %s is %u.",
uint8_t{format}, uint8_t{lowest_compatible}, PACKAGE_NAME, uint8_t{FILE_FORMAT}));
}
s >> nKey;
s >> nNew;
s >> nTried;
int nUBuckets = 0;
s >> nUBuckets;
if (format >= Format::V1_DETERMINISTIC) {
nUBuckets ^= (1 << 30);
}
if (nNew > ADDRMAN_NEW_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE || nNew < 0) {
throw std::ios_base::failure(
strprintf("Corrupt CAddrMan serialization: nNew=%d, should be in [0, %d]",
nNew,
ADDRMAN_NEW_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE));
}
if (nTried > ADDRMAN_TRIED_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE || nTried < 0) {
throw std::ios_base::failure(
strprintf("Corrupt CAddrMan serialization: nTried=%d, should be in [0, %d]",
nTried,
ADDRMAN_TRIED_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE));
}
// Deserialize entries from the new table.
for (int n = 0; n < nNew; n++) {
CAddrInfo &info = mapInfo[n];
s >> info;
mapAddr[info] = n;
info.nRandomPos = vRandom.size();
vRandom.push_back(n);
}
nIdCount = nNew;
// Deserialize entries from the tried table.
int nLost = 0;
for (int n = 0; n < nTried; n++) {
CAddrInfo info;
s >> info;
int nKBucket = info.GetTriedBucket(nKey, m_asmap);
int nKBucketPos = info.GetBucketPosition(nKey, false, nKBucket);
if (info.IsValid()
&& vvTried[nKBucket][nKBucketPos] == -1) {
info.nRandomPos = vRandom.size();
info.fInTried = true;
vRandom.push_back(nIdCount);
mapInfo[nIdCount] = info;
mapAddr[info] = nIdCount;
vvTried[nKBucket][nKBucketPos] = nIdCount;
nIdCount++;
} else {
nLost++;
}
}
nTried -= nLost;
// Store positions in the new table buckets to apply later (if possible).
// An entry may appear in up to ADDRMAN_NEW_BUCKETS_PER_ADDRESS buckets,
// so we store all bucket-entry_index pairs to iterate through later.
std::vector<std::pair<int, int>> bucket_entries;
for (int bucket = 0; bucket < nUBuckets; ++bucket) {
int num_entries{0};
s >> num_entries;
for (int n = 0; n < num_entries; ++n) {
int entry_index{0};
s >> entry_index;
if (entry_index >= 0 && entry_index < nNew) {
bucket_entries.emplace_back(bucket, entry_index);
}
}
}
// If the bucket count and asmap checksum haven't changed, then attempt
// to restore the entries to the buckets/positions they were in before
// serialization.
uint256 supplied_asmap_checksum;
if (m_asmap.size() != 0) {
supplied_asmap_checksum = SerializeHash(m_asmap);
}
uint256 serialized_asmap_checksum;
if (format >= Format::V2_ASMAP) {
s >> serialized_asmap_checksum;
}
const bool restore_bucketing{nUBuckets == ADDRMAN_NEW_BUCKET_COUNT &&
serialized_asmap_checksum == supplied_asmap_checksum};
if (!restore_bucketing) {
LogPrint(BCLog::ADDRMAN, "Bucketing method was updated, re-bucketing addrman entries from disk\n");
}
for (auto bucket_entry : bucket_entries) {
int bucket{bucket_entry.first};
const int entry_index{bucket_entry.second};
CAddrInfo& info = mapInfo[entry_index];
// Don't store the entry in the new bucket if it's not a valid address for our addrman
if (!info.IsValid()) continue;
// The entry shouldn't appear in more than
// ADDRMAN_NEW_BUCKETS_PER_ADDRESS. If it has already, just skip
// this bucket_entry.
if (info.nRefCount >= ADDRMAN_NEW_BUCKETS_PER_ADDRESS) continue;
int bucket_position = info.GetBucketPosition(nKey, true, bucket);
if (restore_bucketing && vvNew[bucket][bucket_position] == -1) {
// Bucketing has not changed, using existing bucket positions for the new table
vvNew[bucket][bucket_position] = entry_index;
++info.nRefCount;
} else {
// In case the new table data cannot be used (bucket count wrong or new asmap),
// try to give them a reference based on their primary source address.
bucket = info.GetNewBucket(nKey, m_asmap);
bucket_position = info.GetBucketPosition(nKey, true, bucket);
if (vvNew[bucket][bucket_position] == -1) {
vvNew[bucket][bucket_position] = entry_index;
++info.nRefCount;
}
}
}
// Prune new entries with refcount 0 (as a result of collisions or invalid address).
int nLostUnk = 0;
for (auto it = mapInfo.cbegin(); it != mapInfo.cend(); ) {
if (it->second.fInTried == false && it->second.nRefCount == 0) {
const auto itCopy = it++;
Delete(itCopy->first);
++nLostUnk;
} else {
++it;
}
}
if (nLost + nLostUnk > 0) {
LogPrint(BCLog::ADDRMAN, "addrman lost %i new and %i tried addresses due to collisions or invalid addresses\n", nLostUnk, nLost);
}
const int check_code{ForceCheckAddrman()};
if (check_code != 0) {
throw std::ios_base::failure(strprintf(
"Corrupt data. Consistency check failed with code %s",
check_code));
}
}
// explicit instantiation
template void CAddrMan::Serialize(CHashWriter& s) const;
template void CAddrMan::Serialize(CAutoFile& s) const;
template void CAddrMan::Serialize(CDataStream& s) const;
template void CAddrMan::Unserialize(CAutoFile& s);
template void CAddrMan::Unserialize(CHashVerifier<CAutoFile>& s);
template void CAddrMan::Unserialize(CDataStream& s);
template void CAddrMan::Unserialize(CHashVerifier<CDataStream>& s);
CAddrInfo* CAddrMan::Find(const CNetAddr& addr, int* pnId)
{
AssertLockHeld(cs);
const auto it = mapAddr.find(addr);
if (it == mapAddr.end())
return nullptr;
if (pnId)
*pnId = (*it).second;
const auto it2 = mapInfo.find((*it).second);
if (it2 != mapInfo.end())
return &(*it2).second;
return nullptr;
}
CAddrInfo* CAddrMan::Create(const CAddress& addr, const CNetAddr& addrSource, int* pnId)
{
AssertLockHeld(cs);
int nId = nIdCount++;
mapInfo[nId] = CAddrInfo(addr, addrSource);
mapAddr[addr] = nId;
mapInfo[nId].nRandomPos = vRandom.size();
vRandom.push_back(nId);
if (pnId)
*pnId = nId;
return &mapInfo[nId];
}
void CAddrMan::SwapRandom(unsigned int nRndPos1, unsigned int nRndPos2) const
{
AssertLockHeld(cs);
if (nRndPos1 == nRndPos2)
return;
assert(nRndPos1 < vRandom.size() && nRndPos2 < vRandom.size());
int nId1 = vRandom[nRndPos1];
int nId2 = vRandom[nRndPos2];
const auto it_1{mapInfo.find(nId1)};
const auto it_2{mapInfo.find(nId2)};
assert(it_1 != mapInfo.end());
assert(it_2 != mapInfo.end());
it_1->second.nRandomPos = nRndPos2;
it_2->second.nRandomPos = nRndPos1;
vRandom[nRndPos1] = nId2;
vRandom[nRndPos2] = nId1;
}
void CAddrMan::Delete(int nId)
{
AssertLockHeld(cs);
assert(mapInfo.count(nId) != 0);
CAddrInfo& info = mapInfo[nId];
assert(!info.fInTried);
assert(info.nRefCount == 0);
SwapRandom(info.nRandomPos, vRandom.size() - 1);
vRandom.pop_back();
mapAddr.erase(info);
mapInfo.erase(nId);
nNew--;
}
void CAddrMan::ClearNew(int nUBucket, int nUBucketPos)
{
AssertLockHeld(cs);
// if there is an entry in the specified bucket, delete it.
if (vvNew[nUBucket][nUBucketPos] != -1) {
int nIdDelete = vvNew[nUBucket][nUBucketPos];
CAddrInfo& infoDelete = mapInfo[nIdDelete];
assert(infoDelete.nRefCount > 0);
infoDelete.nRefCount--;
vvNew[nUBucket][nUBucketPos] = -1;
if (infoDelete.nRefCount == 0) {
Delete(nIdDelete);
}
}
}
void CAddrMan::MakeTried(CAddrInfo& info, int nId)
{
AssertLockHeld(cs);
// remove the entry from all new buckets
const int start_bucket{info.GetNewBucket(nKey, m_asmap)};
for (int n = 0; n < ADDRMAN_NEW_BUCKET_COUNT; ++n) {
const int bucket{(start_bucket + n) % ADDRMAN_NEW_BUCKET_COUNT};
const int pos{info.GetBucketPosition(nKey, true, bucket)};
if (vvNew[bucket][pos] == nId) {
vvNew[bucket][pos] = -1;
info.nRefCount--;
if (info.nRefCount == 0) break;
}
}
nNew--;
assert(info.nRefCount == 0);
// which tried bucket to move the entry to
int nKBucket = info.GetTriedBucket(nKey, m_asmap);
int nKBucketPos = info.GetBucketPosition(nKey, false, nKBucket);
// first make space to add it (the existing tried entry there is moved to new, deleting whatever is there).
if (vvTried[nKBucket][nKBucketPos] != -1) {
// find an item to evict
int nIdEvict = vvTried[nKBucket][nKBucketPos];
assert(mapInfo.count(nIdEvict) == 1);
CAddrInfo& infoOld = mapInfo[nIdEvict];
// Remove the to-be-evicted item from the tried set.
infoOld.fInTried = false;
vvTried[nKBucket][nKBucketPos] = -1;
nTried--;
// find which new bucket it belongs to
int nUBucket = infoOld.GetNewBucket(nKey, m_asmap);
int nUBucketPos = infoOld.GetBucketPosition(nKey, true, nUBucket);
ClearNew(nUBucket, nUBucketPos);
assert(vvNew[nUBucket][nUBucketPos] == -1);
// Enter it into the new set again.
infoOld.nRefCount = 1;
vvNew[nUBucket][nUBucketPos] = nIdEvict;
nNew++;
}
assert(vvTried[nKBucket][nKBucketPos] == -1);
vvTried[nKBucket][nKBucketPos] = nId;
nTried++;
info.fInTried = true;
}
void CAddrMan::Good_(const CService& addr, bool test_before_evict, int64_t nTime)
{
AssertLockHeld(cs);
int nId;
nLastGood = nTime;
CAddrInfo* pinfo = Find(addr, &nId);
// if not found, bail out
if (!pinfo)
return;
CAddrInfo& info = *pinfo;
// check whether we are talking about the exact same CService (including same port)
if (info != addr)
return;
// update info
info.nLastSuccess = nTime;
info.nLastTry = nTime;
info.nAttempts = 0;
// nTime is not updated here, to avoid leaking information about
// currently-connected peers.
// if it is already in the tried set, don't do anything else
if (info.fInTried)
return;
// if it is not in new, something bad happened
if (!Assume(info.nRefCount > 0)) {
return;
}
// which tried bucket to move the entry to
int tried_bucket = info.GetTriedBucket(nKey, m_asmap);
int tried_bucket_pos = info.GetBucketPosition(nKey, false, tried_bucket);
// Will moving this address into tried evict another entry?
if (test_before_evict && (vvTried[tried_bucket][tried_bucket_pos] != -1)) {
// Output the entry we'd be colliding with, for debugging purposes
auto colliding_entry = mapInfo.find(vvTried[tried_bucket][tried_bucket_pos]);
LogPrint(BCLog::ADDRMAN, "Collision inserting element into tried table (%s), moving %s to m_tried_collisions=%d\n", colliding_entry != mapInfo.end() ? colliding_entry->second.ToString() : "", addr.ToString(), m_tried_collisions.size());
if (m_tried_collisions.size() < ADDRMAN_SET_TRIED_COLLISION_SIZE) {
m_tried_collisions.insert(nId);
}
} else {
LogPrint(BCLog::ADDRMAN, "Moving %s to tried\n", addr.ToString());
// move nId to the tried tables
MakeTried(info, nId);
}
}
bool CAddrMan::Add_(const CAddress& addr, const CNetAddr& source, int64_t nTimePenalty)
{
AssertLockHeld(cs);
if (!addr.IsRoutable())
return false;
bool fNew = false;
int nId;
CAddrInfo* pinfo = Find(addr, &nId);
// Do not set a penalty for a source's self-announcement
if (addr == source) {
nTimePenalty = 0;
}
if (pinfo) {
// periodically update nTime
bool fCurrentlyOnline = (GetAdjustedTime() - addr.nTime < 24 * 60 * 60);
int64_t nUpdateInterval = (fCurrentlyOnline ? 60 * 60 : 24 * 60 * 60);
if (addr.nTime && (!pinfo->nTime || pinfo->nTime < addr.nTime - nUpdateInterval - nTimePenalty))
pinfo->nTime = std::max((int64_t)0, addr.nTime - nTimePenalty);
// add services
pinfo->nServices = ServiceFlags(pinfo->nServices | addr.nServices);
// do not update if no new information is present
if (!addr.nTime || (pinfo->nTime && addr.nTime <= pinfo->nTime))
return false;
// do not update if the entry was already in the "tried" table
if (pinfo->fInTried)
return false;
// do not update if the max reference count is reached
if (pinfo->nRefCount == ADDRMAN_NEW_BUCKETS_PER_ADDRESS)
return false;
// stochastic test: previous nRefCount == N: 2^N times harder to increase it
int nFactor = 1;
for (int n = 0; n < pinfo->nRefCount; n++)
nFactor *= 2;
if (nFactor > 1 && (insecure_rand.randrange(nFactor) != 0))
return false;
} else {
pinfo = Create(addr, source, &nId);
pinfo->nTime = std::max((int64_t)0, (int64_t)pinfo->nTime - nTimePenalty);
nNew++;
fNew = true;
}
int nUBucket = pinfo->GetNewBucket(nKey, source, m_asmap);
int nUBucketPos = pinfo->GetBucketPosition(nKey, true, nUBucket);
if (vvNew[nUBucket][nUBucketPos] != nId) {
bool fInsert = vvNew[nUBucket][nUBucketPos] == -1;
if (!fInsert) {
CAddrInfo& infoExisting = mapInfo[vvNew[nUBucket][nUBucketPos]];
if (infoExisting.IsTerrible() || (infoExisting.nRefCount > 1 && pinfo->nRefCount == 0)) {
// Overwrite the existing new table entry.
fInsert = true;
}
}
if (fInsert) {
ClearNew(nUBucket, nUBucketPos);
pinfo->nRefCount++;
vvNew[nUBucket][nUBucketPos] = nId;
} else {
if (pinfo->nRefCount == 0) {
Delete(nId);
}
}
}
return fNew;
}
void CAddrMan::Attempt_(const CService& addr, bool fCountFailure, int64_t nTime)
{
AssertLockHeld(cs);
CAddrInfo* pinfo = Find(addr);
// if not found, bail out
if (!pinfo)
return;
CAddrInfo& info = *pinfo;
// check whether we are talking about the exact same CService (including same port)
if (info != addr)
return;
// update info
info.nLastTry = nTime;
if (fCountFailure && info.nLastCountAttempt < nLastGood) {
info.nLastCountAttempt = nTime;
info.nAttempts++;
}
}
CAddrInfo CAddrMan::Select_(bool newOnly) const
{
AssertLockHeld(cs);
if (vRandom.empty())
return CAddrInfo();
if (newOnly && nNew == 0)
return CAddrInfo();
// Use a 50% chance for choosing between tried and new table entries.
if (!newOnly &&
(nTried > 0 && (nNew == 0 || insecure_rand.randbool() == 0))) {
// use a tried node
double fChanceFactor = 1.0;
while (1) {
int nKBucket = insecure_rand.randrange(ADDRMAN_TRIED_BUCKET_COUNT);
int nKBucketPos = insecure_rand.randrange(ADDRMAN_BUCKET_SIZE);
while (vvTried[nKBucket][nKBucketPos] == -1) {
nKBucket = (nKBucket + insecure_rand.randbits(ADDRMAN_TRIED_BUCKET_COUNT_LOG2)) % ADDRMAN_TRIED_BUCKET_COUNT;
nKBucketPos = (nKBucketPos + insecure_rand.randbits(ADDRMAN_BUCKET_SIZE_LOG2)) % ADDRMAN_BUCKET_SIZE;
}
int nId = vvTried[nKBucket][nKBucketPos];
const auto it_found{mapInfo.find(nId)};
assert(it_found != mapInfo.end());
const CAddrInfo& info{it_found->second};
if (insecure_rand.randbits(30) < fChanceFactor * info.GetChance() * (1 << 30))
return info;
fChanceFactor *= 1.2;
}
} else {
// use a new node
double fChanceFactor = 1.0;
while (1) {
int nUBucket = insecure_rand.randrange(ADDRMAN_NEW_BUCKET_COUNT);
int nUBucketPos = insecure_rand.randrange(ADDRMAN_BUCKET_SIZE);
while (vvNew[nUBucket][nUBucketPos] == -1) {
nUBucket = (nUBucket + insecure_rand.randbits(ADDRMAN_NEW_BUCKET_COUNT_LOG2)) % ADDRMAN_NEW_BUCKET_COUNT;
nUBucketPos = (nUBucketPos + insecure_rand.randbits(ADDRMAN_BUCKET_SIZE_LOG2)) % ADDRMAN_BUCKET_SIZE;
}
int nId = vvNew[nUBucket][nUBucketPos];
const auto it_found{mapInfo.find(nId)};
assert(it_found != mapInfo.end());
const CAddrInfo& info{it_found->second};
if (insecure_rand.randbits(30) < fChanceFactor * info.GetChance() * (1 << 30))
return info;
fChanceFactor *= 1.2;
}
}
}
void CAddrMan::Check() const
{
AssertLockHeld(cs);
// Run consistency checks 1 in m_consistency_check_ratio times if enabled
if (m_consistency_check_ratio == 0) return;
if (insecure_rand.randrange(m_consistency_check_ratio) >= 1) return;
const int err{ForceCheckAddrman()};
if (err) {
LogPrintf("ADDRMAN CONSISTENCY CHECK FAILED!!! err=%i\n", err);
assert(false);
}
}
int CAddrMan::ForceCheckAddrman() const
{
AssertLockHeld(cs);
LogPrint(BCLog::ADDRMAN, "Addrman checks started: new %i, tried %i, total %u\n", nNew, nTried, vRandom.size());
std::unordered_set<int> setTried;
std::unordered_map<int, int> mapNew;
if (vRandom.size() != (size_t)(nTried + nNew))
return -7;
for (const auto& entry : mapInfo) {
int n = entry.first;
const CAddrInfo& info = entry.second;
if (info.fInTried) {
if (!info.nLastSuccess)
return -1;
if (info.nRefCount)
return -2;
setTried.insert(n);
} else {
if (info.nRefCount < 0 || info.nRefCount > ADDRMAN_NEW_BUCKETS_PER_ADDRESS)
return -3;
if (!info.nRefCount)
return -4;
mapNew[n] = info.nRefCount;
}
const auto it{mapAddr.find(info)};
if (it == mapAddr.end() || it->second != n) {
return -5;
}
if (info.nRandomPos < 0 || (size_t)info.nRandomPos >= vRandom.size() || vRandom[info.nRandomPos] != n)
return -14;
if (info.nLastTry < 0)
return -6;
if (info.nLastSuccess < 0)
return -8;
}
if (setTried.size() != (size_t)nTried)
return -9;
if (mapNew.size() != (size_t)nNew)
return -10;
for (int n = 0; n < ADDRMAN_TRIED_BUCKET_COUNT; n++) {
for (int i = 0; i < ADDRMAN_BUCKET_SIZE; i++) {
if (vvTried[n][i] != -1) {
if (!setTried.count(vvTried[n][i]))
return -11;
const auto it{mapInfo.find(vvTried[n][i])};
if (it == mapInfo.end() || it->second.GetTriedBucket(nKey, m_asmap) != n) {
return -17;
}
if (it->second.GetBucketPosition(nKey, false, n) != i) {
return -18;
}
setTried.erase(vvTried[n][i]);
}
}
}
for (int n = 0; n < ADDRMAN_NEW_BUCKET_COUNT; n++) {
for (int i = 0; i < ADDRMAN_BUCKET_SIZE; i++) {
if (vvNew[n][i] != -1) {
if (!mapNew.count(vvNew[n][i]))
return -12;
const auto it{mapInfo.find(vvNew[n][i])};
if (it == mapInfo.end() || it->second.GetBucketPosition(nKey, true, n) != i) {
return -19;
}
if (--mapNew[vvNew[n][i]] == 0)
mapNew.erase(vvNew[n][i]);
}
}
}
if (setTried.size())
return -13;
if (mapNew.size())
return -15;
if (nKey.IsNull())
return -16;
LogPrint(BCLog::ADDRMAN, "Addrman checks completed successfully\n");
return 0;
}
void CAddrMan::GetAddr_(std::vector<CAddress>& vAddr, size_t max_addresses, size_t max_pct, std::optional<Network> network) const
{
AssertLockHeld(cs);
size_t nNodes = vRandom.size();
if (max_pct != 0) {
nNodes = max_pct * nNodes / 100;
}
if (max_addresses != 0) {
nNodes = std::min(nNodes, max_addresses);
}
// gather a list of random nodes, skipping those of low quality
const int64_t now{GetAdjustedTime()};
for (unsigned int n = 0; n < vRandom.size(); n++) {
if (vAddr.size() >= nNodes)
break;
int nRndPos = insecure_rand.randrange(vRandom.size() - n) + n;
SwapRandom(n, nRndPos);
const auto it{mapInfo.find(vRandom[n])};
assert(it != mapInfo.end());
const CAddrInfo& ai{it->second};
// Filter by network (optional)
if (network != std::nullopt && ai.GetNetClass() != network) continue;
// Filter for quality
if (ai.IsTerrible(now)) continue;
vAddr.push_back(ai);
}
}
void CAddrMan::Connected_(const CService& addr, int64_t nTime)
{
AssertLockHeld(cs);
CAddrInfo* pinfo = Find(addr);
// if not found, bail out
if (!pinfo)
return;
CAddrInfo& info = *pinfo;
// check whether we are talking about the exact same CService (including same port)
if (info != addr)
return;
// update info
int64_t nUpdateInterval = 20 * 60;
if (nTime - info.nTime > nUpdateInterval)
info.nTime = nTime;
}
void CAddrMan::SetServices_(const CService& addr, ServiceFlags nServices)
{
AssertLockHeld(cs);
CAddrInfo* pinfo = Find(addr);
// if not found, bail out
if (!pinfo)
return;
CAddrInfo& info = *pinfo;
// check whether we are talking about the exact same CService (including same port)
if (info != addr)
return;
// update info
info.nServices = nServices;
}
void CAddrMan::ResolveCollisions_()
{
AssertLockHeld(cs);
for (std::set<int>::iterator it = m_tried_collisions.begin(); it != m_tried_collisions.end();) {
int id_new = *it;
bool erase_collision = false;
// If id_new not found in mapInfo remove it from m_tried_collisions
if (mapInfo.count(id_new) != 1) {
erase_collision = true;
} else {
CAddrInfo& info_new = mapInfo[id_new];
// Which tried bucket to move the entry to.
int tried_bucket = info_new.GetTriedBucket(nKey, m_asmap);
int tried_bucket_pos = info_new.GetBucketPosition(nKey, false, tried_bucket);
if (!info_new.IsValid()) { // id_new may no longer map to a valid address
erase_collision = true;
} else if (vvTried[tried_bucket][tried_bucket_pos] != -1) { // The position in the tried bucket is not empty
// Get the to-be-evicted address that is being tested
int id_old = vvTried[tried_bucket][tried_bucket_pos];
CAddrInfo& info_old = mapInfo[id_old];
// Has successfully connected in last X hours
if (GetAdjustedTime() - info_old.nLastSuccess < ADDRMAN_REPLACEMENT_HOURS*(60*60)) {
erase_collision = true;
} else if (GetAdjustedTime() - info_old.nLastTry < ADDRMAN_REPLACEMENT_HOURS*(60*60)) { // attempted to connect and failed in last X hours
// Give address at least 60 seconds to successfully connect
if (GetAdjustedTime() - info_old.nLastTry > 60) {
LogPrint(BCLog::ADDRMAN, "Replacing %s with %s in tried table\n", info_old.ToString(), info_new.ToString());
// Replaces an existing address already in the tried table with the new address
Good_(info_new, false, GetAdjustedTime());
erase_collision = true;
}
} else if (GetAdjustedTime() - info_new.nLastSuccess > ADDRMAN_TEST_WINDOW) {
// If the collision hasn't resolved in some reasonable amount of time,
// just evict the old entry -- we must not be able to
// connect to it for some reason.
LogPrint(BCLog::ADDRMAN, "Unable to test; replacing %s with %s in tried table anyway\n", info_old.ToString(), info_new.ToString());
Good_(info_new, false, GetAdjustedTime());
erase_collision = true;
}
} else { // Collision is not actually a collision anymore
Good_(info_new, false, GetAdjustedTime());
erase_collision = true;
}
}
if (erase_collision) {
m_tried_collisions.erase(it++);
} else {
it++;
}
}
}
CAddrInfo CAddrMan::SelectTriedCollision_()
{
AssertLockHeld(cs);
if (m_tried_collisions.size() == 0) return CAddrInfo();
std::set<int>::iterator it = m_tried_collisions.begin();
// Selects a random element from m_tried_collisions
std::advance(it, insecure_rand.randrange(m_tried_collisions.size()));
int id_new = *it;
// If id_new not found in mapInfo remove it from m_tried_collisions
if (mapInfo.count(id_new) != 1) {
m_tried_collisions.erase(it);
return CAddrInfo();
}
const CAddrInfo& newInfo = mapInfo[id_new];
// which tried bucket to move the entry to
int tried_bucket = newInfo.GetTriedBucket(nKey, m_asmap);
int tried_bucket_pos = newInfo.GetBucketPosition(nKey, false, tried_bucket);
int id_old = vvTried[tried_bucket][tried_bucket_pos];
return mapInfo[id_old];
}