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// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2020 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#if defined(HAVE_CONFIG_H)
#include <config/bitcoin-config.h>
#endif
#include <net.h>
#include <banman.h>
#include <clientversion.h>
#include <compat.h>
#include <consensus/consensus.h>
#include <crypto/sha256.h>
#include <i2p.h>
#include <net_permissions.h>
#include <netaddress.h>
#include <netbase.h>
#include <node/ui_interface.h>
#include <protocol.h>
#include <random.h>
#include <scheduler.h>
#include <util/sock.h>
#include <util/strencodings.h>
#include <util/thread.h>
#include <util/trace.h>
#include <util/translation.h>
#ifdef WIN32
#include <string.h>
#else
#include <fcntl.h>
#endif
#if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
#include <ifaddrs.h>
#endif
#ifdef USE_POLL
#include <poll.h>
#endif
#include <algorithm>
#include <array>
#include <cstdint>
#include <functional>
#include <optional>
#include <unordered_map>
#include <math.h>
/** Maximum number of block-relay-only anchor connections */
static constexpr size_t MAX_BLOCK_RELAY_ONLY_ANCHORS = 2;
static_assert (MAX_BLOCK_RELAY_ONLY_ANCHORS <= static_cast<size_t>(MAX_BLOCK_RELAY_ONLY_CONNECTIONS), "MAX_BLOCK_RELAY_ONLY_ANCHORS must not exceed MAX_BLOCK_RELAY_ONLY_CONNECTIONS.");
/** Anchor IP address database file name */
const char* const ANCHORS_DATABASE_FILENAME = "anchors.dat";
// How often to dump addresses to peers.dat
static constexpr std::chrono::minutes DUMP_PEERS_INTERVAL{15};
/** Number of DNS seeds to query when the number of connections is low. */
static constexpr int DNSSEEDS_TO_QUERY_AT_ONCE = 3;
/** How long to delay before querying DNS seeds
*
* If we have more than THRESHOLD entries in addrman, then it's likely
* that we got those addresses from having previously connected to the P2P
* network, and that we'll be able to successfully reconnect to the P2P
* network via contacting one of them. So if that's the case, spend a
* little longer trying to connect to known peers before querying the
* DNS seeds.
*/
static constexpr std::chrono::seconds DNSSEEDS_DELAY_FEW_PEERS{11};
static constexpr std::chrono::minutes DNSSEEDS_DELAY_MANY_PEERS{5};
static constexpr int DNSSEEDS_DELAY_PEER_THRESHOLD = 1000; // "many" vs "few" peers
/** The default timeframe for -maxuploadtarget. 1 day. */
static constexpr std::chrono::seconds MAX_UPLOAD_TIMEFRAME{60 * 60 * 24};
// We add a random period time (0 to 1 seconds) to feeler connections to prevent synchronization.
#define FEELER_SLEEP_WINDOW 1
/** Used to pass flags to the Bind() function */
enum BindFlags {
BF_NONE = 0,
BF_EXPLICIT = (1U << 0),
BF_REPORT_ERROR = (1U << 1),
/**
* Do not call AddLocal() for our special addresses, e.g., for incoming
* Tor connections, to prevent gossiping them over the network.
*/
BF_DONT_ADVERTISE = (1U << 2),
};
// The set of sockets cannot be modified while waiting
// The sleep time needs to be small to avoid new sockets stalling
static const uint64_t SELECT_TIMEOUT_MILLISECONDS = 50;
const std::string NET_MESSAGE_COMMAND_OTHER = "*other*";
static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL; // SHA256("netgroup")[0:8]
static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; // SHA256("localhostnonce")[0:8]
static const uint64_t RANDOMIZER_ID_ADDRCACHE = 0x1cf2e4ddd306dda9ULL; // SHA256("addrcache")[0:8]
//
// Global state variables
//
bool fDiscover = true;
bool fListen = true;
RecursiveMutex cs_mapLocalHost;
std::map<CNetAddr, LocalServiceInfo> mapLocalHost GUARDED_BY(cs_mapLocalHost);
static bool vfLimited[NET_MAX] GUARDED_BY(cs_mapLocalHost) = {};
std::string strSubVersion;
void CConnman::AddAddrFetch(const std::string& strDest)
{
LOCK(m_addr_fetches_mutex);
m_addr_fetches.push_back(strDest);
}
uint16_t GetListenPort()
{
return static_cast<uint16_t>(gArgs.GetArg("-port", Params().GetDefaultPort()));
}
// find 'best' local address for a particular peer
bool GetLocal(CService& addr, const CNetAddr *paddrPeer)
{
if (!fListen)
return false;
int nBestScore = -1;
int nBestReachability = -1;
{
LOCK(cs_mapLocalHost);
for (const auto& entry : mapLocalHost)
{
int nScore = entry.second.nScore;
int nReachability = entry.first.GetReachabilityFrom(paddrPeer);
if (nReachability > nBestReachability || (nReachability == nBestReachability && nScore > nBestScore))
{
addr = CService(entry.first, entry.second.nPort);
nBestReachability = nReachability;
nBestScore = nScore;
}
}
}
return nBestScore >= 0;
}
//! Convert the serialized seeds into usable address objects.
static std::vector<CAddress> ConvertSeeds(const std::vector<uint8_t> &vSeedsIn)
{
// It'll only connect to one or two seed nodes because once it connects,
// it'll get a pile of addresses with newer timestamps.
// Seed nodes are given a random 'last seen time' of between one and two
// weeks ago.
const int64_t nOneWeek = 7*24*60*60;
std::vector<CAddress> vSeedsOut;
FastRandomContext rng;
CDataStream s(vSeedsIn, SER_NETWORK, PROTOCOL_VERSION | ADDRV2_FORMAT);
while (!s.eof()) {
CService endpoint;
s >> endpoint;
CAddress addr{endpoint, GetDesirableServiceFlags(NODE_NONE)};
addr.nTime = GetTime() - rng.randrange(nOneWeek) - nOneWeek;
LogPrint(BCLog::NET, "Added hardcoded seed: %s\n", addr.ToString());
vSeedsOut.push_back(addr);
}
return vSeedsOut;
}
// get best local address for a particular peer as a CAddress
// Otherwise, return the unroutable 0.0.0.0 but filled in with
// the normal parameters, since the IP may be changed to a useful
// one by discovery.
CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices)
{
CAddress ret(CService(CNetAddr(),GetListenPort()), nLocalServices);
CService addr;
if (GetLocal(addr, paddrPeer))
{
ret = CAddress(addr, nLocalServices);
}
ret.nTime = GetAdjustedTime();
return ret;
}
static int GetnScore(const CService& addr)
{
LOCK(cs_mapLocalHost);
if (mapLocalHost.count(addr) == 0) return 0;
return mapLocalHost[addr].nScore;
}
// Is our peer's addrLocal potentially useful as an external IP source?
bool IsPeerAddrLocalGood(CNode *pnode)
{
CService addrLocal = pnode->GetAddrLocal();
return fDiscover && pnode->addr.IsRoutable() && addrLocal.IsRoutable() &&
IsReachable(addrLocal.GetNetwork());
}
std::optional<CAddress> GetLocalAddrForPeer(CNode *pnode)
{
CAddress addrLocal = GetLocalAddress(&pnode->addr, pnode->GetLocalServices());
if (gArgs.GetBoolArg("-addrmantest", false)) {
// use IPv4 loopback during addrmantest
addrLocal = CAddress(CService(LookupNumeric("127.0.0.1", GetListenPort())), pnode->GetLocalServices());
}
// If discovery is enabled, sometimes give our peer the address it
// tells us that it sees us as in case it has a better idea of our
// address than we do.
FastRandomContext rng;
if (IsPeerAddrLocalGood(pnode) && (!addrLocal.IsRoutable() ||
rng.randbits((GetnScore(addrLocal) > LOCAL_MANUAL) ? 3 : 1) == 0))
{
addrLocal.SetIP(pnode->GetAddrLocal());
}
if (addrLocal.IsRoutable() || gArgs.GetBoolArg("-addrmantest", false))
{
LogPrint(BCLog::NET, "Advertising address %s to peer=%d\n", addrLocal.ToString(), pnode->GetId());
return addrLocal;
}
// Address is unroutable. Don't advertise.
return std::nullopt;
}
// learn a new local address
bool AddLocal(const CService& addr, int nScore)
{
if (!addr.IsRoutable())
return false;
if (!fDiscover && nScore < LOCAL_MANUAL)
return false;
if (!IsReachable(addr))
return false;
LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore);
{
LOCK(cs_mapLocalHost);
bool fAlready = mapLocalHost.count(addr) > 0;
LocalServiceInfo &info = mapLocalHost[addr];
if (!fAlready || nScore >= info.nScore) {
info.nScore = nScore + (fAlready ? 1 : 0);
info.nPort = addr.GetPort();
}
}
return true;
}
bool AddLocal(const CNetAddr &addr, int nScore)
{
return AddLocal(CService(addr, GetListenPort()), nScore);
}
void RemoveLocal(const CService& addr)
{
LOCK(cs_mapLocalHost);
LogPrintf("RemoveLocal(%s)\n", addr.ToString());
mapLocalHost.erase(addr);
}
void SetReachable(enum Network net, bool reachable)
{
if (net == NET_UNROUTABLE || net == NET_INTERNAL)
return;
LOCK(cs_mapLocalHost);
vfLimited[net] = !reachable;
}
bool IsReachable(enum Network net)
{
LOCK(cs_mapLocalHost);
return !vfLimited[net];
}
bool IsReachable(const CNetAddr &addr)
{
return IsReachable(addr.GetNetwork());
}
/** vote for a local address */
bool SeenLocal(const CService& addr)
{
{
LOCK(cs_mapLocalHost);
if (mapLocalHost.count(addr) == 0)
return false;
mapLocalHost[addr].nScore++;
}
return true;
}
/** check whether a given address is potentially local */
bool IsLocal(const CService& addr)
{
LOCK(cs_mapLocalHost);
return mapLocalHost.count(addr) > 0;
}
CNode* CConnman::FindNode(const CNetAddr& ip)
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (static_cast<CNetAddr>(pnode->addr) == ip) {
return pnode;
}
}
return nullptr;
}
CNode* CConnman::FindNode(const CSubNet& subNet)
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (subNet.Match(static_cast<CNetAddr>(pnode->addr))) {
return pnode;
}
}
return nullptr;
}
CNode* CConnman::FindNode(const std::string& addrName)
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (pnode->GetAddrName() == addrName) {
return pnode;
}
}
return nullptr;
}
CNode* CConnman::FindNode(const CService& addr)
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (static_cast<CService>(pnode->addr) == addr) {
return pnode;
}
}
return nullptr;
}
bool CConnman::AlreadyConnectedToAddress(const CAddress& addr)
{
return FindNode(static_cast<CNetAddr>(addr)) || FindNode(addr.ToStringIPPort());
}
bool CConnman::CheckIncomingNonce(uint64_t nonce)
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (!pnode->fSuccessfullyConnected && !pnode->IsInboundConn() && pnode->GetLocalNonce() == nonce)
return false;
}
return true;
}
/** Get the bind address for a socket as CAddress */
static CAddress GetBindAddress(SOCKET sock)
{
CAddress addr_bind;
struct sockaddr_storage sockaddr_bind;
socklen_t sockaddr_bind_len = sizeof(sockaddr_bind);
if (sock != INVALID_SOCKET) {
if (!getsockname(sock, (struct sockaddr*)&sockaddr_bind, &sockaddr_bind_len)) {
addr_bind.SetSockAddr((const struct sockaddr*)&sockaddr_bind);
} else {
LogPrint(BCLog::NET, "Warning: getsockname failed\n");
}
}
return addr_bind;
}
CNode* CConnman::ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure, ConnectionType conn_type)
{
assert(conn_type != ConnectionType::INBOUND);
if (pszDest == nullptr) {
if (IsLocal(addrConnect))
return nullptr;
// Look for an existing connection
CNode* pnode = FindNode(static_cast<CService>(addrConnect));
if (pnode)
{
LogPrintf("Failed to open new connection, already connected\n");
return nullptr;
}
}
/// debug print
LogPrint(BCLog::NET, "trying connection %s lastseen=%.1fhrs\n",
pszDest ? pszDest : addrConnect.ToString(),
pszDest ? 0.0 : (double)(GetAdjustedTime() - addrConnect.nTime)/3600.0);
// Resolve
const uint16_t default_port{pszDest != nullptr ? Params().GetDefaultPort(pszDest) :
Params().GetDefaultPort()};
if (pszDest) {
std::vector<CService> resolved;
if (Lookup(pszDest, resolved, default_port, fNameLookup && !HaveNameProxy(), 256) && !resolved.empty()) {
addrConnect = CAddress(resolved[GetRand(resolved.size())], NODE_NONE);
if (!addrConnect.IsValid()) {
LogPrint(BCLog::NET, "Resolver returned invalid address %s for %s\n", addrConnect.ToString(), pszDest);
return nullptr;
}
// It is possible that we already have a connection to the IP/port pszDest resolved to.
// In that case, drop the connection that was just created, and return the existing CNode instead.
// Also store the name we used to connect in that CNode, so that future FindNode() calls to that
// name catch this early.
LOCK(cs_vNodes);
CNode* pnode = FindNode(static_cast<CService>(addrConnect));
if (pnode)
{
pnode->MaybeSetAddrName(std::string(pszDest));
LogPrintf("Failed to open new connection, already connected\n");
return nullptr;
}
}
}
// Connect
bool connected = false;
std::unique_ptr<Sock> sock;
proxyType proxy;
CAddress addr_bind;
assert(!addr_bind.IsValid());
if (addrConnect.IsValid()) {
bool proxyConnectionFailed = false;
if (addrConnect.GetNetwork() == NET_I2P && m_i2p_sam_session.get() != nullptr) {
i2p::Connection conn;
if (m_i2p_sam_session->Connect(addrConnect, conn, proxyConnectionFailed)) {
connected = true;
sock = std::move(conn.sock);
addr_bind = CAddress{conn.me, NODE_NONE};
}
} else if (GetProxy(addrConnect.GetNetwork(), proxy)) {
sock = CreateSock(proxy.proxy);
if (!sock) {
return nullptr;
}
connected = ConnectThroughProxy(proxy, addrConnect.ToStringIP(), addrConnect.GetPort(),
*sock, nConnectTimeout, proxyConnectionFailed);
} else {
// no proxy needed (none set for target network)
sock = CreateSock(addrConnect);
if (!sock) {
return nullptr;
}
connected = ConnectSocketDirectly(addrConnect, *sock, nConnectTimeout,
conn_type == ConnectionType::MANUAL);
}
if (!proxyConnectionFailed) {
// If a connection to the node was attempted, and failure (if any) is not caused by a problem connecting to
// the proxy, mark this as an attempt.
addrman.Attempt(addrConnect, fCountFailure);
}
} else if (pszDest && GetNameProxy(proxy)) {
sock = CreateSock(proxy.proxy);
if (!sock) {
return nullptr;
}
std::string host;
uint16_t port{default_port};
SplitHostPort(std::string(pszDest), port, host);
bool proxyConnectionFailed;
connected = ConnectThroughProxy(proxy, host, port, *sock, nConnectTimeout,
proxyConnectionFailed);
}
if (!connected) {
return nullptr;
}
// Add node
NodeId id = GetNewNodeId();
uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
if (!addr_bind.IsValid()) {
addr_bind = GetBindAddress(sock->Get());
}
CNode* pnode = new CNode(id, nLocalServices, sock->Release(), addrConnect, CalculateKeyedNetGroup(addrConnect), nonce, addr_bind, pszDest ? pszDest : "", conn_type, /* inbound_onion */ false);
pnode->AddRef();
// We're making a new connection, harvest entropy from the time (and our peer count)
RandAddEvent((uint32_t)id);
return pnode;
}
void CNode::CloseSocketDisconnect()
{
fDisconnect = true;
LOCK(cs_hSocket);
if (hSocket != INVALID_SOCKET)
{
LogPrint(BCLog::NET, "disconnecting peer=%d\n", id);
CloseSocket(hSocket);
}
}
void CConnman::AddWhitelistPermissionFlags(NetPermissionFlags& flags, const CNetAddr &addr) const {
for (const auto& subnet : vWhitelistedRange) {
if (subnet.m_subnet.Match(addr)) NetPermissions::AddFlag(flags, subnet.m_flags);
}
}
std::string ConnectionTypeAsString(ConnectionType conn_type)
{
switch (conn_type) {
case ConnectionType::INBOUND:
return "inbound";
case ConnectionType::MANUAL:
return "manual";
case ConnectionType::FEELER:
return "feeler";
case ConnectionType::OUTBOUND_FULL_RELAY:
return "outbound-full-relay";
case ConnectionType::BLOCK_RELAY:
return "block-relay-only";
case ConnectionType::ADDR_FETCH:
return "addr-fetch";
} // no default case, so the compiler can warn about missing cases
assert(false);
}
std::string CNode::GetAddrName() const {
LOCK(cs_addrName);
return addrName;
}
void CNode::MaybeSetAddrName(const std::string& addrNameIn) {
LOCK(cs_addrName);
if (addrName.empty()) {
addrName = addrNameIn;
}
}
CService CNode::GetAddrLocal() const {
LOCK(cs_addrLocal);
return addrLocal;
}
void CNode::SetAddrLocal(const CService& addrLocalIn) {
LOCK(cs_addrLocal);
if (addrLocal.IsValid()) {
error("Addr local already set for node: %i. Refusing to change from %s to %s", id, addrLocal.ToString(), addrLocalIn.ToString());
} else {
addrLocal = addrLocalIn;
}
}
Network CNode::ConnectedThroughNetwork() const
{
return m_inbound_onion ? NET_ONION : addr.GetNetClass();
}
#undef X
#define X(name) stats.name = name
void CNode::copyStats(CNodeStats &stats, const std::vector<bool> &m_asmap)
{
stats.nodeid = this->GetId();
X(nServices);
X(addr);
X(addrBind);
stats.m_network = ConnectedThroughNetwork();
stats.m_mapped_as = addr.GetMappedAS(m_asmap);
if (m_tx_relay != nullptr) {
LOCK(m_tx_relay->cs_filter);
stats.fRelayTxes = m_tx_relay->fRelayTxes;
} else {
stats.fRelayTxes = false;
}
X(nLastSend);
X(nLastRecv);
X(nLastTXTime);
X(nLastBlockTime);
X(nTimeConnected);
X(nTimeOffset);
stats.addrName = GetAddrName();
X(nVersion);
{
LOCK(cs_SubVer);
X(cleanSubVer);
}
stats.fInbound = IsInboundConn();
X(m_bip152_highbandwidth_to);
X(m_bip152_highbandwidth_from);
{
LOCK(cs_vSend);
X(mapSendBytesPerMsgCmd);
X(nSendBytes);
}
{
LOCK(cs_vRecv);
X(mapRecvBytesPerMsgCmd);
X(nRecvBytes);
}
X(m_permissionFlags);
if (m_tx_relay != nullptr) {
stats.minFeeFilter = m_tx_relay->minFeeFilter;
} else {
stats.minFeeFilter = 0;
}
X(m_last_ping_time);
X(m_min_ping_time);
// Leave string empty if addrLocal invalid (not filled in yet)
CService addrLocalUnlocked = GetAddrLocal();
stats.addrLocal = addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToString() : "";
X(m_conn_type);
}
#undef X
bool CNode::ReceiveMsgBytes(Span<const uint8_t> msg_bytes, bool& complete)
{
complete = false;
const auto time = GetTime<std::chrono::microseconds>();
LOCK(cs_vRecv);
nLastRecv = std::chrono::duration_cast<std::chrono::seconds>(time).count();
nRecvBytes += msg_bytes.size();
while (msg_bytes.size() > 0) {
// absorb network data
int handled = m_deserializer->Read(msg_bytes);
if (handled < 0) {
// Serious header problem, disconnect from the peer.
return false;
}
if (m_deserializer->Complete()) {
// decompose a transport agnostic CNetMessage from the deserializer
uint32_t out_err_raw_size{0};
std::optional<CNetMessage> result{m_deserializer->GetMessage(time, out_err_raw_size)};
if (!result) {
// Message deserialization failed. Drop the message but don't disconnect the peer.
// store the size of the corrupt message
mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER)->second += out_err_raw_size;
continue;
}
//store received bytes per message command
//to prevent a memory DOS, only allow valid commands
mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(result->m_command);
if (i == mapRecvBytesPerMsgCmd.end())
i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER);
assert(i != mapRecvBytesPerMsgCmd.end());
i->second += result->m_raw_message_size;
// push the message to the process queue,
vRecvMsg.push_back(std::move(*result));
complete = true;
}
}
return true;
}
int V1TransportDeserializer::readHeader(Span<const uint8_t> msg_bytes)
{
// copy data to temporary parsing buffer
unsigned int nRemaining = CMessageHeader::HEADER_SIZE - nHdrPos;
unsigned int nCopy = std::min<unsigned int>(nRemaining, msg_bytes.size());
memcpy(&hdrbuf[nHdrPos], msg_bytes.data(), nCopy);
nHdrPos += nCopy;
// if header incomplete, exit
if (nHdrPos < CMessageHeader::HEADER_SIZE)
return nCopy;
// deserialize to CMessageHeader
try {
hdrbuf >> hdr;
}
catch (const std::exception&) {
LogPrint(BCLog::NET, "Header error: Unable to deserialize, peer=%d\n", m_node_id);
return -1;
}
// Check start string, network magic
if (memcmp(hdr.pchMessageStart, m_chain_params.MessageStart(), CMessageHeader::MESSAGE_START_SIZE) != 0) {
LogPrint(BCLog::NET, "Header error: Wrong MessageStart %s received, peer=%d\n", HexStr(hdr.pchMessageStart), m_node_id);
return -1;
}
// reject messages larger than MAX_SIZE or MAX_PROTOCOL_MESSAGE_LENGTH
if (hdr.nMessageSize > MAX_SIZE || hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) {
LogPrint(BCLog::NET, "Header error: Size too large (%s, %u bytes), peer=%d\n", SanitizeString(hdr.GetCommand()), hdr.nMessageSize, m_node_id);
return -1;
}
// switch state to reading message data
in_data = true;
return nCopy;
}
int V1TransportDeserializer::readData(Span<const uint8_t> msg_bytes)
{
unsigned int nRemaining = hdr.nMessageSize - nDataPos;
unsigned int nCopy = std::min<unsigned int>(nRemaining, msg_bytes.size());
if (vRecv.size() < nDataPos + nCopy) {
// Allocate up to 256 KiB ahead, but never more than the total message size.
vRecv.resize(std::min(hdr.nMessageSize, nDataPos + nCopy + 256 * 1024));
}
hasher.Write(msg_bytes.first(nCopy));
memcpy(&vRecv[nDataPos], msg_bytes.data(), nCopy);
nDataPos += nCopy;
return nCopy;
}
const uint256& V1TransportDeserializer::GetMessageHash() const
{
assert(Complete());
if (data_hash.IsNull())
hasher.Finalize(data_hash);
return data_hash;
}
std::optional<CNetMessage> V1TransportDeserializer::GetMessage(const std::chrono::microseconds time, uint32_t& out_err_raw_size)
{
// decompose a single CNetMessage from the TransportDeserializer
std::optional<CNetMessage> msg(std::move(vRecv));
// store command string, time, and sizes
msg->m_command = hdr.GetCommand();
msg->m_time = time;
msg->m_message_size = hdr.nMessageSize;
msg->m_raw_message_size = hdr.nMessageSize + CMessageHeader::HEADER_SIZE;
uint256 hash = GetMessageHash();
// We just received a message off the wire, harvest entropy from the time (and the message checksum)
RandAddEvent(ReadLE32(hash.begin()));
// Check checksum and header command string
if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) != 0) {
LogPrint(BCLog::NET, "Header error: Wrong checksum (%s, %u bytes), expected %s was %s, peer=%d\n",
SanitizeString(msg->m_command), msg->m_message_size,
HexStr(Span<uint8_t>(hash.begin(), hash.begin() + CMessageHeader::CHECKSUM_SIZE)),
HexStr(hdr.pchChecksum),
m_node_id);
out_err_raw_size = msg->m_raw_message_size;
msg = std::nullopt;
} else if (!hdr.IsCommandValid()) {
LogPrint(BCLog::NET, "Header error: Invalid message type (%s, %u bytes), peer=%d\n",
SanitizeString(hdr.GetCommand()), msg->m_message_size, m_node_id);
out_err_raw_size = msg->m_raw_message_size;
msg.reset();
}
// Always reset the network deserializer (prepare for the next message)
Reset();
return msg;
}
void V1TransportSerializer::prepareForTransport(CSerializedNetMsg& msg, std::vector<unsigned char>& header) {
// create dbl-sha256 checksum
uint256 hash = Hash(msg.data);
// create header
CMessageHeader hdr(Params().MessageStart(), msg.m_type.c_str(), msg.data.size());
memcpy(hdr.pchChecksum, hash.begin(), CMessageHeader::CHECKSUM_SIZE);
// serialize header
header.reserve(CMessageHeader::HEADER_SIZE);
CVectorWriter{SER_NETWORK, INIT_PROTO_VERSION, header, 0, hdr};
}
size_t CConnman::SocketSendData(CNode& node) const
{
auto it = node.vSendMsg.begin();
size_t nSentSize = 0;
while (it != node.vSendMsg.end()) {
const auto& data = *it;
assert(data.size() > node.nSendOffset);
int nBytes = 0;
{
LOCK(node.cs_hSocket);
if (node.hSocket == INVALID_SOCKET)
break;
nBytes = send(node.hSocket, reinterpret_cast<const char*>(data.data()) + node.nSendOffset, data.size() - node.nSendOffset, MSG_NOSIGNAL | MSG_DONTWAIT);
}
if (nBytes > 0) {
node.nLastSend = GetTimeSeconds();
node.nSendBytes += nBytes;
node.nSendOffset += nBytes;
nSentSize += nBytes;
if (node.nSendOffset == data.size()) {
node.nSendOffset = 0;
node.nSendSize -= data.size();
node.fPauseSend = node.nSendSize > nSendBufferMaxSize;
it++;
} else {
// could not send full message; stop sending more
break;
}
} else {
if (nBytes < 0) {
// error
int nErr = WSAGetLastError();
if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS) {
LogPrint(BCLog::NET, "socket send error for peer=%d: %s\n", node.GetId(), NetworkErrorString(nErr));
node.CloseSocketDisconnect();
}
}
// couldn't send anything at all
break;
}
}
if (it == node.vSendMsg.end()) {
assert(node.nSendOffset == 0);
assert(node.nSendSize == 0);
}
node.vSendMsg.erase(node.vSendMsg.begin(), it);
return nSentSize;
}
static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
{
return a.m_min_ping_time > b.m_min_ping_time;
}
static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
{
return a.nTimeConnected > b.nTimeConnected;
}
static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) {
return a.nKeyedNetGroup < b.nKeyedNetGroup;
}
static bool CompareNodeBlockTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
{
// There is a fall-through here because it is common for a node to have many peers which have not yet relayed a block.
if (a.nLastBlockTime != b.nLastBlockTime) return a.nLastBlockTime < b.nLastBlockTime;
if (a.fRelevantServices != b.fRelevantServices) return b.fRelevantServices;
return a.nTimeConnected > b.nTimeConnected;
}
static bool CompareNodeTXTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
{
// There is a fall-through here because it is common for a node to have more than a few peers that have not yet relayed txn.
if (a.nLastTXTime != b.nLastTXTime) return a.nLastTXTime < b.nLastTXTime;
if (a.fRelayTxes != b.fRelayTxes) return b.fRelayTxes;
if (a.fBloomFilter != b.fBloomFilter) return a.fBloomFilter;
return a.nTimeConnected > b.nTimeConnected;
}
// Pick out the potential block-relay only peers, and sort them by last block time.
static bool CompareNodeBlockRelayOnlyTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b)
{
if (a.fRelayTxes != b.fRelayTxes) return a.fRelayTxes;
if (a.nLastBlockTime != b.nLastBlockTime) return a.nLastBlockTime < b.nLastBlockTime;
if (a.fRelevantServices != b.fRelevantServices) return b.fRelevantServices;
return a.nTimeConnected > b.nTimeConnected;
}
/**
* Sort eviction candidates by network/localhost and connection uptime.
* Candidates near the beginning are more likely to be evicted, and those
* near the end are more likely to be protected, e.g. less likely to be evicted.
* - First, nodes that are not `is_local` and that do not belong to `network`,
* sorted by increasing uptime (from most recently connected to connected longer).
* - Then, nodes that are `is_local` or belong to `network`, sorted by increasing uptime.
*/
struct CompareNodeNetworkTime {
const bool m_is_local;
const Network m_network;
CompareNodeNetworkTime(bool is_local, Network network) : m_is_local(is_local), m_network(network) {}
bool operator()(const NodeEvictionCandidate& a, const NodeEvictionCandidate& b) const
{
if (m_is_local && a.m_is_local != b.m_is_local) return b.m_is_local;
if ((a.m_network == m_network) != (b.m_network == m_network)) return b.m_network == m_network;
return a.nTimeConnected > b.nTimeConnected;
};
};
//! Sort an array by the specified comparator, then erase the last K elements where predicate is true.
template <typename T, typename Comparator>
static void EraseLastKElements(
std::vector<T>& elements, Comparator comparator, size_t k,
std::function<bool(const NodeEvictionCandidate&)> predicate = [](const NodeEvictionCandidate& n) { return true; })
{
std::sort(elements.begin(), elements.end(), comparator);
size_t eraseSize = std::min(k, elements.size());
elements.erase(std::remove_if(elements.end() - eraseSize, elements.end(), predicate), elements.end());
}
void ProtectEvictionCandidatesByRatio(std::vector<NodeEvictionCandidate>& eviction_candidates)
{
// Protect the half of the remaining nodes which have been connected the longest.
// This replicates the non-eviction implicit behavior, and precludes attacks that start later.
// To favorise the diversity of our peer connections, reserve up to half of these protected
// spots for Tor/onion, localhost and I2P peers, even if they're not longest uptime overall.
// This helps protect these higher-latency peers that tend to be otherwise
// disadvantaged under our eviction criteria.
const size_t initial_size = eviction_candidates.size();
const size_t total_protect_size{initial_size / 2};
// Disadvantaged networks to protect: I2P, localhost, Tor/onion. In case of equal counts, earlier
// array members have first opportunity to recover unused slots from the previous iteration.
struct Net { bool is_local; Network id; size_t count; };
std::array<Net, 3> networks{
{{false, NET_I2P, 0}, {/* localhost */ true, NET_MAX, 0}, {false, NET_ONION, 0}}};
// Count and store the number of eviction candidates per network.
for (Net& n : networks) {
n.count = std::count_if(eviction_candidates.cbegin(), eviction_candidates.cend(),
[&n](const NodeEvictionCandidate& c) {
return n.is_local ? c.m_is_local : c.m_network == n.id;
});
}
// Sort `networks` by ascending candidate count, to give networks having fewer candidates
// the first opportunity to recover unused protected slots from the previous iteration.
std::stable_sort(networks.begin(), networks.end(), [](Net a, Net b) { return a.count < b.count; });
// Protect up to 25% of the eviction candidates by disadvantaged network.
const size_t max_protect_by_network{total_protect_size / 2};
size_t num_protected{0};
while (num_protected < max_protect_by_network) {
// Count the number of disadvantaged networks from which we have peers to protect.
auto num_networks = std::count_if(networks.begin(), networks.end(), [](const Net& n) { return n.count; });
if (num_networks == 0) {
break;
}
const size_t disadvantaged_to_protect{max_protect_by_network - num_protected};
const size_t protect_per_network{std::max(disadvantaged_to_protect / num_networks, static_cast<size_t>(1))};
// Early exit flag if there are no remaining candidates by disadvantaged network.
bool protected_at_least_one{false};
for (Net& n : networks) {
if (n.count == 0) continue;
const size_t before = eviction_candidates.size();
EraseLastKElements(eviction_candidates, CompareNodeNetworkTime(n.is_local, n.id),
protect_per_network, [&n](const NodeEvictionCandidate& c) {
return n.is_local ? c.m_is_local : c.m_network == n.id;
});
const size_t after = eviction_candidates.size();
if (before > after) {
protected_at_least_one = true;
const size_t delta{before - after};
num_protected += delta;
if (num_protected >= max_protect_by_network) {
break;
}
n.count -= delta;
}
}
if (!protected_at_least_one) {
break;
}
}
// Calculate how many we removed, and update our total number of peers that
// we want to protect based on uptime accordingly.
assert(num_protected == initial_size - eviction_candidates.size());
const size_t remaining_to_protect{total_protect_size - num_protected};
EraseLastKElements(eviction_candidates, ReverseCompareNodeTimeConnected, remaining_to_protect);
}
[[nodiscard]] std::optional<NodeId> SelectNodeToEvict(std::vector<NodeEvictionCandidate>&& vEvictionCandidates)
{
// Protect connections with certain characteristics
// Deterministically select 4 peers to protect by netgroup.
// An attacker cannot predict which netgroups will be protected
EraseLastKElements(vEvictionCandidates, CompareNetGroupKeyed, 4);
// Protect the 8 nodes with the lowest minimum ping time.
// An attacker cannot manipulate this metric without physically moving nodes closer to the target.
EraseLastKElements(vEvictionCandidates, ReverseCompareNodeMinPingTime, 8);
// Protect 4 nodes that most recently sent us novel transactions accepted into our mempool.
// An attacker cannot manipulate this metric without performing useful work.
EraseLastKElements(vEvictionCandidates, CompareNodeTXTime, 4);
// Protect up to 8 non-tx-relay peers that have sent us novel blocks.
EraseLastKElements(vEvictionCandidates, CompareNodeBlockRelayOnlyTime, 8,
[](const NodeEvictionCandidate& n) { return !n.fRelayTxes && n.fRelevantServices; });
// Protect 4 nodes that most recently sent us novel blocks.
// An attacker cannot manipulate this metric without performing useful work.
EraseLastKElements(vEvictionCandidates, CompareNodeBlockTime, 4);
// Protect some of the remaining eviction candidates by ratios of desirable
// or disadvantaged characteristics.
ProtectEvictionCandidatesByRatio(vEvictionCandidates);
if (vEvictionCandidates.empty()) return std::nullopt;
// If any remaining peers are preferred for eviction consider only them.
// This happens after the other preferences since if a peer is really the best by other criteria (esp relaying blocks)
// then we probably don't want to evict it no matter what.
if (std::any_of(vEvictionCandidates.begin(),vEvictionCandidates.end(),[](NodeEvictionCandidate const &n){return n.prefer_evict;})) {
vEvictionCandidates.erase(std::remove_if(vEvictionCandidates.begin(),vEvictionCandidates.end(),
[](NodeEvictionCandidate const &n){return !n.prefer_evict;}),vEvictionCandidates.end());
}
// Identify the network group with the most connections and youngest member.
// (vEvictionCandidates is already sorted by reverse connect time)
uint64_t naMostConnections;
unsigned int nMostConnections = 0;
int64_t nMostConnectionsTime = 0;
std::map<uint64_t, std::vector<NodeEvictionCandidate> > mapNetGroupNodes;
for (const NodeEvictionCandidate &node : vEvictionCandidates) {
std::vector<NodeEvictionCandidate> &group = mapNetGroupNodes[node.nKeyedNetGroup];
group.push_back(node);
const int64_t grouptime = group[0].nTimeConnected;
if (group.size() > nMostConnections || (group.size() == nMostConnections && grouptime > nMostConnectionsTime)) {
nMostConnections = group.size();
nMostConnectionsTime = grouptime;
naMostConnections = node.nKeyedNetGroup;
}
}
// Reduce to the network group with the most connections
vEvictionCandidates = std::move(mapNetGroupNodes[naMostConnections]);
// Disconnect from the network group with the most connections
return vEvictionCandidates.front().id;
}
/** Try to find a connection to evict when the node is full.
* Extreme care must be taken to avoid opening the node to attacker
* triggered network partitioning.
* The strategy used here is to protect a small number of peers
* for each of several distinct characteristics which are difficult
* to forge. In order to partition a node the attacker must be
* simultaneously better at all of them than honest peers.
*/
bool CConnman::AttemptToEvictConnection()
{
std::vector<NodeEvictionCandidate> vEvictionCandidates;
{
LOCK(cs_vNodes);
for (const CNode* node : vNodes) {
if (node->HasPermission(NetPermissionFlags::NoBan))
continue;
if (!node->IsInboundConn())
continue;
if (node->fDisconnect)
continue;
bool peer_relay_txes = false;
bool peer_filter_not_null = false;
if (node->m_tx_relay != nullptr) {
LOCK(node->m_tx_relay->cs_filter);
peer_relay_txes = node->m_tx_relay->fRelayTxes;
peer_filter_not_null = node->m_tx_relay->pfilter != nullptr;
}
NodeEvictionCandidate candidate = {node->GetId(), node->nTimeConnected, node->m_min_ping_time,
node->nLastBlockTime, node->nLastTXTime,
HasAllDesirableServiceFlags(node->nServices),
peer_relay_txes, peer_filter_not_null, node->nKeyedNetGroup,
node->m_prefer_evict, node->addr.IsLocal(),
node->ConnectedThroughNetwork()};
vEvictionCandidates.push_back(candidate);
}
}
const std::optional<NodeId> node_id_to_evict = SelectNodeToEvict(std::move(vEvictionCandidates));
if (!node_id_to_evict) {
return false;
}
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (pnode->GetId() == *node_id_to_evict) {
LogPrint(BCLog::NET, "selected %s connection for eviction peer=%d; disconnecting\n", pnode->ConnectionTypeAsString(), pnode->GetId());
pnode->fDisconnect = true;
return true;
}
}
return false;
}
void CConnman::AcceptConnection(const ListenSocket& hListenSocket) {
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
SOCKET hSocket = accept(hListenSocket.socket, (struct sockaddr*)&sockaddr, &len);
CAddress addr;
if (hSocket == INVALID_SOCKET) {
const int nErr = WSAGetLastError();
if (nErr != WSAEWOULDBLOCK) {
LogPrintf("socket error accept failed: %s\n", NetworkErrorString(nErr));
}
return;
}
if (!addr.SetSockAddr((const struct sockaddr*)&sockaddr)) {
LogPrintf("Warning: Unknown socket family\n");
}
const CAddress addr_bind = GetBindAddress(hSocket);
NetPermissionFlags permissionFlags = NetPermissionFlags::None;
hListenSocket.AddSocketPermissionFlags(permissionFlags);
CreateNodeFromAcceptedSocket(hSocket, permissionFlags, addr_bind, addr);
}
void CConnman::CreateNodeFromAcceptedSocket(SOCKET hSocket,
NetPermissionFlags permissionFlags,
const CAddress& addr_bind,
const CAddress& addr)
{
int nInbound = 0;
int nMaxInbound = nMaxConnections - m_max_outbound;
AddWhitelistPermissionFlags(permissionFlags, addr);
if (NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::Implicit)) {
NetPermissions::ClearFlag(permissionFlags, NetPermissionFlags::Implicit);
if (gArgs.GetBoolArg("-whitelistforcerelay", DEFAULT_WHITELISTFORCERELAY)) NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::ForceRelay);
if (gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::Relay);
NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::Mempool);
NetPermissions::AddFlag(permissionFlags, NetPermissionFlags::NoBan);
}
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->IsInboundConn()) nInbound++;
}
}
if (!fNetworkActive) {
LogPrint(BCLog::NET, "connection from %s dropped: not accepting new connections\n", addr.ToString());
CloseSocket(hSocket);
return;
}
if (!IsSelectableSocket(hSocket))
{
LogPrintf("connection from %s dropped: non-selectable socket\n", addr.ToString());
CloseSocket(hSocket);
return;
}
// According to the internet TCP_NODELAY is not carried into accepted sockets
// on all platforms. Set it again here just to be sure.
SetSocketNoDelay(hSocket);
// Don't accept connections from banned peers.
bool banned = m_banman && m_banman->IsBanned(addr);
if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::NoBan) && banned)
{
LogPrint(BCLog::NET, "connection from %s dropped (banned)\n", addr.ToString());
CloseSocket(hSocket);
return;
}
// Only accept connections from discouraged peers if our inbound slots aren't (almost) full.
bool discouraged = m_banman && m_banman->IsDiscouraged(addr);
if (!NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::NoBan) && nInbound + 1 >= nMaxInbound && discouraged)
{
LogPrint(BCLog::NET, "connection from %s dropped (discouraged)\n", addr.ToString());
CloseSocket(hSocket);
return;
}
if (nInbound >= nMaxInbound)
{
if (!AttemptToEvictConnection()) {
// No connection to evict, disconnect the new connection
LogPrint(BCLog::NET, "failed to find an eviction candidate - connection dropped (full)\n");
CloseSocket(hSocket);
return;
}
}
NodeId id = GetNewNodeId();
uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE).Write(id).Finalize();
ServiceFlags nodeServices = nLocalServices;
if (NetPermissions::HasFlag(permissionFlags, NetPermissionFlags::BloomFilter)) {
nodeServices = static_cast<ServiceFlags>(nodeServices | NODE_BLOOM);
}
const bool inbound_onion = std::find(m_onion_binds.begin(), m_onion_binds.end(), addr_bind) != m_onion_binds.end();
CNode* pnode = new CNode(id, nodeServices, hSocket, addr, CalculateKeyedNetGroup(addr), nonce, addr_bind, "", ConnectionType::INBOUND, inbound_onion);
pnode->AddRef();
pnode->m_permissionFlags = permissionFlags;
pnode->m_prefer_evict = discouraged;
m_msgproc->InitializeNode(pnode);
LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToString());
{
LOCK(cs_vNodes);
vNodes.push_back(pnode);
}
// We received a new connection, harvest entropy from the time (and our peer count)
RandAddEvent((uint32_t)id);
}
bool CConnman::AddConnection(const std::string& address, ConnectionType conn_type)
{
std::optional<int> max_connections;
switch (conn_type) {
case ConnectionType::INBOUND:
case ConnectionType::MANUAL:
case ConnectionType::FEELER:
return false;
case ConnectionType::OUTBOUND_FULL_RELAY:
max_connections = m_max_outbound_full_relay;
break;
case ConnectionType::BLOCK_RELAY:
max_connections = m_max_outbound_block_relay;
break;
// no limit for ADDR_FETCH because -seednode has no limit either
case ConnectionType::ADDR_FETCH:
break;
} // no default case, so the compiler can warn about missing cases
// Count existing connections
int existing_connections = WITH_LOCK(cs_vNodes,
return std::count_if(vNodes.begin(), vNodes.end(), [conn_type](CNode* node) { return node->m_conn_type == conn_type; }););
// Max connections of specified type already exist
if (max_connections != std::nullopt && existing_connections >= max_connections) return false;
// Max total outbound connections already exist
CSemaphoreGrant grant(*semOutbound, true);
if (!grant) return false;
OpenNetworkConnection(CAddress(), false, &grant, address.c_str(), conn_type);
return true;
}
void CConnman::DisconnectNodes()
{
{
LOCK(cs_vNodes);
if (!fNetworkActive) {
// Disconnect any connected nodes
for (CNode* pnode : vNodes) {
if (!pnode->fDisconnect) {
LogPrint(BCLog::NET, "Network not active, dropping peer=%d\n", pnode->GetId());
pnode->fDisconnect = true;
}
}
}
// Disconnect unused nodes
std::vector<CNode*> vNodesCopy = vNodes;
for (CNode* pnode : vNodesCopy)
{
if (pnode->fDisconnect)
{
// remove from vNodes
vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode), vNodes.end());
// release outbound grant (if any)
pnode->grantOutbound.Release();
// close socket and cleanup
pnode->CloseSocketDisconnect();
// hold in disconnected pool until all refs are released
pnode->Release();
vNodesDisconnected.push_back(pnode);
}
}
}
{
// Delete disconnected nodes
std::list<CNode*> vNodesDisconnectedCopy = vNodesDisconnected;
for (CNode* pnode : vNodesDisconnectedCopy)
{
// Destroy the object only after other threads have stopped using it.
if (pnode->GetRefCount() <= 0) {
vNodesDisconnected.remove(pnode);
DeleteNode(pnode);
}
}
}
}
void CConnman::NotifyNumConnectionsChanged()
{
size_t vNodesSize;
{
LOCK(cs_vNodes);
vNodesSize = vNodes.size();
}
if(vNodesSize != nPrevNodeCount) {
nPrevNodeCount = vNodesSize;
if(clientInterface)
clientInterface->NotifyNumConnectionsChanged(vNodesSize);
}
}
bool CConnman::ShouldRunInactivityChecks(const CNode& node, std::optional<int64_t> now_in) const
{
const int64_t now = now_in ? now_in.value() : GetTimeSeconds();
return node.nTimeConnected + m_peer_connect_timeout < now;
}
bool CConnman::InactivityCheck(const CNode& node) const
{
// Use non-mockable system time (otherwise these timers will pop when we
// use setmocktime in the tests).
int64_t now = GetTimeSeconds();
if (!ShouldRunInactivityChecks(node, now)) return false;
if (node.nLastRecv == 0 || node.nLastSend == 0) {
LogPrint(BCLog::NET, "socket no message in first %i seconds, %d %d peer=%d\n", m_peer_connect_timeout, node.nLastRecv != 0, node.nLastSend != 0, node.GetId());
return true;
}
if (now > node.nLastSend + TIMEOUT_INTERVAL) {
LogPrint(BCLog::NET, "socket sending timeout: %is peer=%d\n", now - node.nLastSend, node.GetId());
return true;
}
if (now > node.nLastRecv + TIMEOUT_INTERVAL) {
LogPrint(BCLog::NET, "socket receive timeout: %is peer=%d\n", now - node.nLastRecv, node.GetId());
return true;
}
if (!node.fSuccessfullyConnected) {
LogPrint(BCLog::NET, "version handshake timeout peer=%d\n", node.GetId());
return true;
}
return false;
}
bool CConnman::GenerateSelectSet(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set, std::set<SOCKET> &error_set)
{
for (const ListenSocket& hListenSocket : vhListenSocket) {
recv_set.insert(hListenSocket.socket);
}
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodes)
{
// Implement the following logic:
// * If there is data to send, select() for sending data. As this only
// happens when optimistic write failed, we choose to first drain the
// write buffer in this case before receiving more. This avoids
// needlessly queueing received data, if the remote peer is not themselves
// receiving data. This means properly utilizing TCP flow control signalling.
// * Otherwise, if there is space left in the receive buffer, select() for
// receiving data.
// * Hand off all complete messages to the processor, to be handled without
// blocking here.
bool select_recv = !pnode->fPauseRecv;
bool select_send;
{
LOCK(pnode->cs_vSend);
select_send = !pnode->vSendMsg.empty();
}
LOCK(pnode->cs_hSocket);
if (pnode->hSocket == INVALID_SOCKET)
continue;
error_set.insert(pnode->hSocket);
if (select_send) {
send_set.insert(pnode->hSocket);
continue;
}
if (select_recv) {
recv_set.insert(pnode->hSocket);
}
}
}
return !recv_set.empty() || !send_set.empty() || !error_set.empty();
}
#ifdef USE_POLL
void CConnman::SocketEvents(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set, std::set<SOCKET> &error_set)
{
std::set<SOCKET> recv_select_set, send_select_set, error_select_set;
if (!GenerateSelectSet(recv_select_set, send_select_set, error_select_set)) {
interruptNet.sleep_for(std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS));
return;
}
std::unordered_map<SOCKET, struct pollfd> pollfds;
for (SOCKET socket_id : recv_select_set) {
pollfds[socket_id].fd = socket_id;
pollfds[socket_id].events |= POLLIN;
}
for (SOCKET socket_id : send_select_set) {
pollfds[socket_id].fd = socket_id;
pollfds[socket_id].events |= POLLOUT;
}
for (SOCKET socket_id : error_select_set) {
pollfds[socket_id].fd = socket_id;
// These flags are ignored, but we set them for clarity
pollfds[socket_id].events |= POLLERR|POLLHUP;
}
std::vector<struct pollfd> vpollfds;
vpollfds.reserve(pollfds.size());
for (auto it : pollfds) {
vpollfds.push_back(std::move(it.second));
}
if (poll(vpollfds.data(), vpollfds.size(), SELECT_TIMEOUT_MILLISECONDS) < 0) return;
if (interruptNet) return;
for (struct pollfd pollfd_entry : vpollfds) {
if (pollfd_entry.revents & POLLIN) recv_set.insert(pollfd_entry.fd);
if (pollfd_entry.revents & POLLOUT) send_set.insert(pollfd_entry.fd);
if (pollfd_entry.revents & (POLLERR|POLLHUP)) error_set.insert(pollfd_entry.fd);
}
}
#else
void CConnman::SocketEvents(std::set<SOCKET> &recv_set, std::set<SOCKET> &send_set, std::set<SOCKET> &error_set)
{
std::set<SOCKET> recv_select_set, send_select_set, error_select_set;
if (!GenerateSelectSet(recv_select_set, send_select_set, error_select_set)) {
interruptNet.sleep_for(std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS));
return;
}
//
// Find which sockets have data to receive
//
struct timeval timeout;
timeout.tv_sec = 0;
timeout.tv_usec = SELECT_TIMEOUT_MILLISECONDS * 1000; // frequency to poll pnode->vSend
fd_set fdsetRecv;
fd_set fdsetSend;
fd_set fdsetError;
FD_ZERO(&fdsetRecv);
FD_ZERO(&fdsetSend);
FD_ZERO(&fdsetError);
SOCKET hSocketMax = 0;
for (SOCKET hSocket : recv_select_set) {
FD_SET(hSocket, &fdsetRecv);
hSocketMax = std::max(hSocketMax, hSocket);
}
for (SOCKET hSocket : send_select_set) {
FD_SET(hSocket, &fdsetSend);
hSocketMax = std::max(hSocketMax, hSocket);
}
for (SOCKET hSocket : error_select_set) {
FD_SET(hSocket, &fdsetError);
hSocketMax = std::max(hSocketMax, hSocket);
}
int nSelect = select(hSocketMax + 1, &fdsetRecv, &fdsetSend, &fdsetError, &timeout);
if (interruptNet)
return;
if (nSelect == SOCKET_ERROR)
{
int nErr = WSAGetLastError();
LogPrintf("socket select error %s\n", NetworkErrorString(nErr));
for (unsigned int i = 0; i <= hSocketMax; i++)
FD_SET(i, &fdsetRecv);
FD_ZERO(&fdsetSend);
FD_ZERO(&fdsetError);
if (!interruptNet.sleep_for(std::chrono::milliseconds(SELECT_TIMEOUT_MILLISECONDS)))
return;
}
for (SOCKET hSocket : recv_select_set) {
if (FD_ISSET(hSocket, &fdsetRecv)) {
recv_set.insert(hSocket);
}
}
for (SOCKET hSocket : send_select_set) {
if (FD_ISSET(hSocket, &fdsetSend)) {
send_set.insert(hSocket);
}
}
for (SOCKET hSocket : error_select_set) {
if (FD_ISSET(hSocket, &fdsetError)) {
error_set.insert(hSocket);
}
}
}
#endif
void CConnman::SocketHandler()
{
std::set<SOCKET> recv_set, send_set, error_set;
SocketEvents(recv_set, send_set, error_set);
if (interruptNet) return;
//
// Accept new connections
//
for (const ListenSocket& hListenSocket : vhListenSocket)
{
if (hListenSocket.socket != INVALID_SOCKET && recv_set.count(hListenSocket.socket) > 0)
{
AcceptConnection(hListenSocket);
}
}
//
// Service each socket
//
std::vector<CNode*> vNodesCopy;
{
LOCK(cs_vNodes);
vNodesCopy = vNodes;
for (CNode* pnode : vNodesCopy)
pnode->AddRef();
}
for (CNode* pnode : vNodesCopy)
{
if (interruptNet)
return;
//
// Receive
//
bool recvSet = false;
bool sendSet = false;
bool errorSet = false;
{
LOCK(pnode->cs_hSocket);
if (pnode->hSocket == INVALID_SOCKET)
continue;
recvSet = recv_set.count(pnode->hSocket) > 0;
sendSet = send_set.count(pnode->hSocket) > 0;
errorSet = error_set.count(pnode->hSocket) > 0;
}
if (recvSet || errorSet)
{
// typical socket buffer is 8K-64K
uint8_t pchBuf[0x10000];
int nBytes = 0;
{
LOCK(pnode->cs_hSocket);
if (pnode->hSocket == INVALID_SOCKET)
continue;
nBytes = recv(pnode->hSocket, (char*)pchBuf, sizeof(pchBuf), MSG_DONTWAIT);
}
if (nBytes > 0)
{
bool notify = false;
if (!pnode->ReceiveMsgBytes(Span<const uint8_t>(pchBuf, nBytes), notify))
pnode->CloseSocketDisconnect();
RecordBytesRecv(nBytes);
if (notify) {
size_t nSizeAdded = 0;
auto it(pnode->vRecvMsg.begin());
for (; it != pnode->vRecvMsg.end(); ++it) {
// vRecvMsg contains only completed CNetMessage
// the single possible partially deserialized message are held by TransportDeserializer
nSizeAdded += it->m_raw_message_size;
}
{
LOCK(pnode->cs_vProcessMsg);
pnode->vProcessMsg.splice(pnode->vProcessMsg.end(), pnode->vRecvMsg, pnode->vRecvMsg.begin(), it);
pnode->nProcessQueueSize += nSizeAdded;
pnode->fPauseRecv = pnode->nProcessQueueSize > nReceiveFloodSize;
}
WakeMessageHandler();
}
}
else if (nBytes == 0)
{
// socket closed gracefully
if (!pnode->fDisconnect) {
LogPrint(BCLog::NET, "socket closed for peer=%d\n", pnode->GetId());
}
pnode->CloseSocketDisconnect();
}
else if (nBytes < 0)
{
// error
int nErr = WSAGetLastError();
if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE && nErr != WSAEINTR && nErr != WSAEINPROGRESS)
{
if (!pnode->fDisconnect) {
LogPrint(BCLog::NET, "socket recv error for peer=%d: %s\n", pnode->GetId(), NetworkErrorString(nErr));
}
pnode->CloseSocketDisconnect();
}
}
}
if (sendSet) {
// Send data
size_t bytes_sent = WITH_LOCK(pnode->cs_vSend, return SocketSendData(*pnode));
if (bytes_sent) RecordBytesSent(bytes_sent);
}
if (InactivityCheck(*pnode)) pnode->fDisconnect = true;
}
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodesCopy)
pnode->Release();
}
}
void CConnman::ThreadSocketHandler()
{
while (!interruptNet)
{
DisconnectNodes();
NotifyNumConnectionsChanged();
SocketHandler();
}
}
void CConnman::WakeMessageHandler()
{
{
LOCK(mutexMsgProc);
fMsgProcWake = true;
}
condMsgProc.notify_one();
}
void CConnman::ThreadDNSAddressSeed()
{
FastRandomContext rng;
std::vector<std::string> seeds = Params().DNSSeeds();
Shuffle(seeds.begin(), seeds.end(), rng);
int seeds_right_now = 0; // Number of seeds left before testing if we have enough connections
int found = 0;
if (gArgs.GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED)) {
// When -forcednsseed is provided, query all.
seeds_right_now = seeds.size();
} else if (addrman.size() == 0) {
// If we have no known peers, query all.
// This will occur on the first run, or if peers.dat has been
// deleted.
seeds_right_now = seeds.size();
}
// goal: only query DNS seed if address need is acute
// * If we have a reasonable number of peers in addrman, spend
// some time trying them first. This improves user privacy by
// creating fewer identifying DNS requests, reduces trust by
// giving seeds less influence on the network topology, and
// reduces traffic to the seeds.
// * When querying DNS seeds query a few at once, this ensures
// that we don't give DNS seeds the ability to eclipse nodes
// that query them.
// * If we continue having problems, eventually query all the
// DNS seeds, and if that fails too, also try the fixed seeds.
// (done in ThreadOpenConnections)
const std::chrono::seconds seeds_wait_time = (addrman.size() >= DNSSEEDS_DELAY_PEER_THRESHOLD ? DNSSEEDS_DELAY_MANY_PEERS : DNSSEEDS_DELAY_FEW_PEERS);
for (const std::string& seed : seeds) {
if (seeds_right_now == 0) {
seeds_right_now += DNSSEEDS_TO_QUERY_AT_ONCE;
if (addrman.size() > 0) {
LogPrintf("Waiting %d seconds before querying DNS seeds.\n", seeds_wait_time.count());
std::chrono::seconds to_wait = seeds_wait_time;
while (to_wait.count() > 0) {
// if sleeping for the MANY_PEERS interval, wake up
// early to see if we have enough peers and can stop
// this thread entirely freeing up its resources
std::chrono::seconds w = std::min(DNSSEEDS_DELAY_FEW_PEERS, to_wait);
if (!interruptNet.sleep_for(w)) return;
to_wait -= w;
int nRelevant = 0;
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->fSuccessfullyConnected && pnode->IsFullOutboundConn()) ++nRelevant;
}
}
if (nRelevant >= 2) {
if (found > 0) {
LogPrintf("%d addresses found from DNS seeds\n", found);
LogPrintf("P2P peers available. Finished DNS seeding.\n");
} else {
LogPrintf("P2P peers available. Skipped DNS seeding.\n");
}
return;
}
}
}
}
if (interruptNet) return;
// hold off on querying seeds if P2P network deactivated
if (!fNetworkActive) {
LogPrintf("Waiting for network to be reactivated before querying DNS seeds.\n");
do {
if (!interruptNet.sleep_for(std::chrono::seconds{1})) return;
} while (!fNetworkActive);
}
LogPrintf("Loading addresses from DNS seed %s\n", seed);
if (HaveNameProxy()) {
AddAddrFetch(seed);
} else {
std::vector<CNetAddr> vIPs;
std::vector<CAddress> vAdd;
ServiceFlags requiredServiceBits = GetDesirableServiceFlags(NODE_NONE);
std::string host = strprintf("x%x.%s", requiredServiceBits, seed);
CNetAddr resolveSource;
if (!resolveSource.SetInternal(host)) {
continue;
}
unsigned int nMaxIPs = 256; // Limits number of IPs learned from a DNS seed
if (LookupHost(host, vIPs, nMaxIPs, true)) {
for (const CNetAddr& ip : vIPs) {
int nOneDay = 24*3600;
CAddress addr = CAddress(CService(ip, Params().GetDefaultPort()), requiredServiceBits);
addr.nTime = GetTime() - 3*nOneDay - rng.randrange(4*nOneDay); // use a random age between 3 and 7 days old
vAdd.push_back(addr);
found++;
}
addrman.Add(vAdd, resolveSource);
} else {
// We now avoid directly using results from DNS Seeds which do not support service bit filtering,
// instead using them as a addrfetch to get nodes with our desired service bits.
AddAddrFetch(seed);
}
}
--seeds_right_now;
}
LogPrintf("%d addresses found from DNS seeds\n", found);
}
void CConnman::DumpAddresses()
{
int64_t nStart = GetTimeMillis();
CAddrDB adb;
adb.Write(addrman);
LogPrint(BCLog::NET, "Flushed %d addresses to peers.dat %dms\n",
addrman.size(), GetTimeMillis() - nStart);
}
void CConnman::ProcessAddrFetch()
{
std::string strDest;
{
LOCK(m_addr_fetches_mutex);
if (m_addr_fetches.empty())
return;
strDest = m_addr_fetches.front();
m_addr_fetches.pop_front();
}
CAddress addr;
CSemaphoreGrant grant(*semOutbound, true);
if (grant) {
OpenNetworkConnection(addr, false, &grant, strDest.c_str(), ConnectionType::ADDR_FETCH);
}
}
bool CConnman::GetTryNewOutboundPeer() const
{
return m_try_another_outbound_peer;
}
void CConnman::SetTryNewOutboundPeer(bool flag)
{
m_try_another_outbound_peer = flag;
LogPrint(BCLog::NET, "net: setting try another outbound peer=%s\n", flag ? "true" : "false");
}
// Return the number of peers we have over our outbound connection limit
// Exclude peers that are marked for disconnect, or are going to be
// disconnected soon (eg ADDR_FETCH and FEELER)
// Also exclude peers that haven't finished initial connection handshake yet
// (so that we don't decide we're over our desired connection limit, and then
// evict some peer that has finished the handshake)
int CConnman::GetExtraFullOutboundCount() const
{
int full_outbound_peers = 0;
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->fSuccessfullyConnected && !pnode->fDisconnect && pnode->IsFullOutboundConn()) {
++full_outbound_peers;
}
}
}
return std::max(full_outbound_peers - m_max_outbound_full_relay, 0);
}
int CConnman::GetExtraBlockRelayCount() const
{
int block_relay_peers = 0;
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->fSuccessfullyConnected && !pnode->fDisconnect && pnode->IsBlockOnlyConn()) {
++block_relay_peers;
}
}
}
return std::max(block_relay_peers - m_max_outbound_block_relay, 0);
}
void CConnman::ThreadOpenConnections(const std::vector<std::string> connect)
{
// Connect to specific addresses
if (!connect.empty())
{
for (int64_t nLoop = 0;; nLoop++)
{
ProcessAddrFetch();
for (const std::string& strAddr : connect)
{
CAddress addr(CService(), NODE_NONE);
OpenNetworkConnection(addr, false, nullptr, strAddr.c_str(), ConnectionType::MANUAL);
for (int i = 0; i < 10 && i < nLoop; i++)
{
if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
return;
}
}
if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
return;
}
}
// Initiate network connections
auto start = GetTime<std::chrono::microseconds>();
// Minimum time before next feeler connection (in microseconds).
auto next_feeler = PoissonNextSend(start, FEELER_INTERVAL);
auto next_extra_block_relay = PoissonNextSend(start, EXTRA_BLOCK_RELAY_ONLY_PEER_INTERVAL);
const bool dnsseed = gArgs.GetBoolArg("-dnsseed", DEFAULT_DNSSEED);
bool add_fixed_seeds = gArgs.GetBoolArg("-fixedseeds", DEFAULT_FIXEDSEEDS);
if (!add_fixed_seeds) {
LogPrintf("Fixed seeds are disabled\n");
}
while (!interruptNet)
{
ProcessAddrFetch();
if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
return;
CSemaphoreGrant grant(*semOutbound);
if (interruptNet)
return;
if (add_fixed_seeds && addrman.size() == 0) {
// When the node starts with an empty peers.dat, there are a few other sources of peers before
// we fallback on to fixed seeds: -dnsseed, -seednode, -addnode
// If none of those are available, we fallback on to fixed seeds immediately, else we allow
// 60 seconds for any of those sources to populate addrman.
bool add_fixed_seeds_now = false;
// It is cheapest to check if enough time has passed first.
if (GetTime<std::chrono::seconds>() > start + std::chrono::minutes{1}) {
add_fixed_seeds_now = true;
LogPrintf("Adding fixed seeds as 60 seconds have passed and addrman is empty\n");
}
// Checking !dnsseed is cheaper before locking 2 mutexes.
if (!add_fixed_seeds_now && !dnsseed) {
LOCK2(m_addr_fetches_mutex, cs_vAddedNodes);
if (m_addr_fetches.empty() && vAddedNodes.empty()) {
add_fixed_seeds_now = true;
LogPrintf("Adding fixed seeds as -dnsseed=0, -addnode is not provided and all -seednode(s) attempted\n");
}
}
if (add_fixed_seeds_now) {
CNetAddr local;
local.SetInternal("fixedseeds");
addrman.Add(ConvertSeeds(Params().FixedSeeds()), local);
add_fixed_seeds = false;
}
}
//
// Choose an address to connect to based on most recently seen
//
CAddress addrConnect;
// Only connect out to one peer per network group (/16 for IPv4).
int nOutboundFullRelay = 0;
int nOutboundBlockRelay = 0;
std::set<std::vector<unsigned char> > setConnected;
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->IsFullOutboundConn()) nOutboundFullRelay++;
if (pnode->IsBlockOnlyConn()) nOutboundBlockRelay++;
// Netgroups for inbound and manual peers are not excluded because our goal here
// is to not use multiple of our limited outbound slots on a single netgroup
// but inbound and manual peers do not use our outbound slots. Inbound peers
// also have the added issue that they could be attacker controlled and used
// to prevent us from connecting to particular hosts if we used them here.
switch (pnode->m_conn_type) {
case ConnectionType::INBOUND:
case ConnectionType::MANUAL:
break;
case ConnectionType::OUTBOUND_FULL_RELAY:
case ConnectionType::BLOCK_RELAY:
case ConnectionType::ADDR_FETCH:
case ConnectionType::FEELER:
setConnected.insert(pnode->addr.GetGroup(addrman.m_asmap));
} // no default case, so the compiler can warn about missing cases
}
}
ConnectionType conn_type = ConnectionType::OUTBOUND_FULL_RELAY;
auto now = GetTime<std::chrono::microseconds>();
bool anchor = false;
bool fFeeler = false;
// Determine what type of connection to open. Opening
// BLOCK_RELAY connections to addresses from anchors.dat gets the highest
// priority. Then we open OUTBOUND_FULL_RELAY priority until we
// meet our full-relay capacity. Then we open BLOCK_RELAY connection
// until we hit our block-relay-only peer limit.
// GetTryNewOutboundPeer() gets set when a stale tip is detected, so we
// try opening an additional OUTBOUND_FULL_RELAY connection. If none of
// these conditions are met, check to see if it's time to try an extra
// block-relay-only peer (to confirm our tip is current, see below) or the next_feeler
// timer to decide if we should open a FEELER.
if (!m_anchors.empty() && (nOutboundBlockRelay < m_max_outbound_block_relay)) {
conn_type = ConnectionType::BLOCK_RELAY;
anchor = true;
} else if (nOutboundFullRelay < m_max_outbound_full_relay) {
// OUTBOUND_FULL_RELAY
} else if (nOutboundBlockRelay < m_max_outbound_block_relay) {
conn_type = ConnectionType::BLOCK_RELAY;
} else if (GetTryNewOutboundPeer()) {
// OUTBOUND_FULL_RELAY
} else if (now > next_extra_block_relay && m_start_extra_block_relay_peers) {
// Periodically connect to a peer (using regular outbound selection
// methodology from addrman) and stay connected long enough to sync
// headers, but not much else.
//
// Then disconnect the peer, if we haven't learned anything new.
//
// The idea is to make eclipse attacks very difficult to pull off,
// because every few minutes we're finding a new peer to learn headers
// from.
//
// This is similar to the logic for trying extra outbound (full-relay)
// peers, except:
// - we do this all the time on a poisson timer, rather than just when
// our tip is stale
// - we potentially disconnect our next-youngest block-relay-only peer, if our
// newest block-relay-only peer delivers a block more recently.
// See the eviction logic in net_processing.cpp.
//
// Because we can promote these connections to block-relay-only
// connections, they do not get their own ConnectionType enum
// (similar to how we deal with extra outbound peers).
next_extra_block_relay = PoissonNextSend(now, EXTRA_BLOCK_RELAY_ONLY_PEER_INTERVAL);
conn_type = ConnectionType::BLOCK_RELAY;
} else if (now > next_feeler) {
next_feeler = PoissonNextSend(now, FEELER_INTERVAL);
conn_type = ConnectionType::FEELER;
fFeeler = true;
} else {
// skip to next iteration of while loop
continue;
}
addrman.ResolveCollisions();
int64_t nANow = GetAdjustedTime();
int nTries = 0;
while (!interruptNet)
{
if (anchor && !m_anchors.empty()) {
const CAddress addr = m_anchors.back();
m_anchors.pop_back();
if (!addr.IsValid() || IsLocal(addr) || !IsReachable(addr) ||
!HasAllDesirableServiceFlags(addr.nServices) ||
setConnected.count(addr.GetGroup(addrman.m_asmap))) continue;
addrConnect = addr;
LogPrint(BCLog::NET, "Trying to make an anchor connection to %s\n", addrConnect.ToString());
break;
}
// If we didn't find an appropriate destination after trying 100 addresses fetched from addrman,
// stop this loop, and let the outer loop run again (which sleeps, adds seed nodes, recalculates
// already-connected network ranges, ...) before trying new addrman addresses.
nTries++;
if (nTries > 100)
break;
CAddrInfo addr;
if (fFeeler) {
// First, try to get a tried table collision address. This returns
// an empty (invalid) address if there are no collisions to try.
addr = addrman.SelectTriedCollision();
if (!addr.IsValid()) {
// No tried table collisions. Select a new table address
// for our feeler.
addr = addrman.Select(true);
} else if (AlreadyConnectedToAddress(addr)) {
// If test-before-evict logic would have us connect to a
// peer that we're already connected to, just mark that
// address as Good(). We won't be able to initiate the
// connection anyway, so this avoids inadvertently evicting
// a currently-connected peer.
addrman.Good(addr);
// Select a new table address for our feeler instead.
addr = addrman.Select(true);
}
} else {
// Not a feeler
addr = addrman.Select();
}
// Require outbound connections, other than feelers, to be to distinct network groups
if (!fFeeler && setConnected.count(addr.GetGroup(addrman.m_asmap))) {
break;
}
// if we selected an invalid or local address, restart
if (!addr.IsValid() || IsLocal(addr)) {
break;
}
if (!IsReachable(addr))
continue;
// only consider very recently tried nodes after 30 failed attempts
if (nANow - addr.nLastTry < 600 && nTries < 30)
continue;
// for non-feelers, require all the services we'll want,
// for feelers, only require they be a full node (only because most
// SPV clients don't have a good address DB available)
if (!fFeeler && !HasAllDesirableServiceFlags(addr.nServices)) {
continue;
} else if (fFeeler && !MayHaveUsefulAddressDB(addr.nServices)) {
continue;
}
// Do not allow non-default ports, unless after 50 invalid
// addresses selected already. This is to prevent malicious peers
// from advertising themselves as a service on another host and
// port, causing a DoS attack as nodes around the network attempt
// to connect to it fruitlessly.
if (addr.GetPort() != Params().GetDefaultPort(addr.GetNetwork()) && nTries < 50) {
continue;
}
addrConnect = addr;
break;
}
if (addrConnect.IsValid()) {
if (fFeeler) {
// Add small amount of random noise before connection to avoid synchronization.
int randsleep = GetRandInt(FEELER_SLEEP_WINDOW * 1000);
if (!interruptNet.sleep_for(std::chrono::milliseconds(randsleep)))
return;
LogPrint(BCLog::NET, "Making feeler connection to %s\n", addrConnect.ToString());
}
OpenNetworkConnection(addrConnect, (int)setConnected.size() >= std::min(nMaxConnections - 1, 2), &grant, nullptr, conn_type);
}
}
}
std::vector<CAddress> CConnman::GetCurrentBlockRelayOnlyConns() const
{
std::vector<CAddress> ret;
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->IsBlockOnlyConn()) {
ret.push_back(pnode->addr);
}
}
return ret;
}
std::vector<AddedNodeInfo> CConnman::GetAddedNodeInfo() const
{
std::vector<AddedNodeInfo> ret;
std::list<std::string> lAddresses(0);
{
LOCK(cs_vAddedNodes);
ret.reserve(vAddedNodes.size());
std::copy(vAddedNodes.cbegin(), vAddedNodes.cend(), std::back_inserter(lAddresses));
}
// Build a map of all already connected addresses (by IP:port and by name) to inbound/outbound and resolved CService
std::map<CService, bool> mapConnected;
std::map<std::string, std::pair<bool, CService>> mapConnectedByName;
{
LOCK(cs_vNodes);
for (const CNode* pnode : vNodes) {
if (pnode->addr.IsValid()) {
mapConnected[pnode->addr] = pnode->IsInboundConn();
}
std::string addrName = pnode->GetAddrName();
if (!addrName.empty()) {
mapConnectedByName[std::move(addrName)] = std::make_pair(pnode->IsInboundConn(), static_cast<const CService&>(pnode->addr));
}
}
}
for (const std::string& strAddNode : lAddresses) {
CService service(LookupNumeric(strAddNode, Params().GetDefaultPort(strAddNode)));
AddedNodeInfo addedNode{strAddNode, CService(), false, false};
if (service.IsValid()) {
// strAddNode is an IP:port
auto it = mapConnected.find(service);
if (it != mapConnected.end()) {
addedNode.resolvedAddress = service;
addedNode.fConnected = true;
addedNode.fInbound = it->second;
}
} else {
// strAddNode is a name
auto it = mapConnectedByName.find(strAddNode);
if (it != mapConnectedByName.end()) {
addedNode.resolvedAddress = it->second.second;
addedNode.fConnected = true;
addedNode.fInbound = it->second.first;
}
}
ret.emplace_back(std::move(addedNode));
}
return ret;
}
void CConnman::ThreadOpenAddedConnections()
{
while (true)
{
CSemaphoreGrant grant(*semAddnode);
std::vector<AddedNodeInfo> vInfo = GetAddedNodeInfo();
bool tried = false;
for (const AddedNodeInfo& info : vInfo) {
if (!info.fConnected) {
if (!grant.TryAcquire()) {
// If we've used up our semaphore and need a new one, let's not wait here since while we are waiting
// the addednodeinfo state might change.
break;
}
tried = true;
CAddress addr(CService(), NODE_NONE);
OpenNetworkConnection(addr, false, &grant, info.strAddedNode.c_str(), ConnectionType::MANUAL);
if (!interruptNet.sleep_for(std::chrono::milliseconds(500)))
return;
}
}
// Retry every 60 seconds if a connection was attempted, otherwise two seconds
if (!interruptNet.sleep_for(std::chrono::seconds(tried ? 60 : 2)))
return;
}
}
// if successful, this moves the passed grant to the constructed node
void CConnman::OpenNetworkConnection(const CAddress& addrConnect, bool fCountFailure, CSemaphoreGrant *grantOutbound, const char *pszDest, ConnectionType conn_type)
{
assert(conn_type != ConnectionType::INBOUND);
//
// Initiate outbound network connection
//
if (interruptNet) {
return;
}
if (!fNetworkActive) {
return;
}
if (!pszDest) {
bool banned_or_discouraged = m_banman && (m_banman->IsDiscouraged(addrConnect) || m_banman->IsBanned(addrConnect));
if (IsLocal(addrConnect) || banned_or_discouraged || AlreadyConnectedToAddress(addrConnect)) {
return;
}
} else if (FindNode(std::string(pszDest)))
return;
CNode* pnode = ConnectNode(addrConnect, pszDest, fCountFailure, conn_type);
if (!pnode)
return;
if (grantOutbound)
grantOutbound->MoveTo(pnode->grantOutbound);
m_msgproc->InitializeNode(pnode);
{
LOCK(cs_vNodes);
vNodes.push_back(pnode);
}
}
void CConnman::ThreadMessageHandler()
{
FastRandomContext rng;
while (!flagInterruptMsgProc)
{
std::vector<CNode*> vNodesCopy;
{
LOCK(cs_vNodes);
vNodesCopy = vNodes;
for (CNode* pnode : vNodesCopy) {
pnode->AddRef();
}
}
bool fMoreWork = false;
// Randomize the order in which we process messages from/to our peers.
// This prevents attacks in which an attacker exploits having multiple
// consecutive connections in the vNodes list.
Shuffle(vNodesCopy.begin(), vNodesCopy.end(), rng);
for (CNode* pnode : vNodesCopy)
{
if (pnode->fDisconnect)
continue;
// Receive messages
bool fMoreNodeWork = m_msgproc->ProcessMessages(pnode, flagInterruptMsgProc);
fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend);
if (flagInterruptMsgProc)
return;
// Send messages
{
LOCK(pnode->cs_sendProcessing);
m_msgproc->SendMessages(pnode);
}
if (flagInterruptMsgProc)
return;
}
{
LOCK(cs_vNodes);
for (CNode* pnode : vNodesCopy)
pnode->Release();
}
WAIT_LOCK(mutexMsgProc, lock);
if (!fMoreWork) {
condMsgProc.wait_until(lock, std::chrono::steady_clock::now() + std::chrono::milliseconds(100), [this]() EXCLUSIVE_LOCKS_REQUIRED(mutexMsgProc) { return fMsgProcWake; });
}
fMsgProcWake = false;
}
}
void CConnman::ThreadI2PAcceptIncoming()
{
static constexpr auto err_wait_begin = 1s;
static constexpr auto err_wait_cap = 5min;
auto err_wait = err_wait_begin;
bool advertising_listen_addr = false;
i2p::Connection conn;
while (!interruptNet) {
if (!m_i2p_sam_session->Listen(conn)) {
if (advertising_listen_addr && conn.me.IsValid()) {
RemoveLocal(conn.me);
advertising_listen_addr = false;
}
interruptNet.sleep_for(err_wait);
if (err_wait < err_wait_cap) {
err_wait *= 2;
}
continue;
}
if (!advertising_listen_addr) {
AddLocal(conn.me, LOCAL_MANUAL);
advertising_listen_addr = true;
}
if (!m_i2p_sam_session->Accept(conn)) {
continue;
}
CreateNodeFromAcceptedSocket(conn.sock->Release(), NetPermissionFlags::None,
CAddress{conn.me, NODE_NONE}, CAddress{conn.peer, NODE_NONE});
}
}
bool CConnman::BindListenPort(const CService& addrBind, bilingual_str& strError, NetPermissionFlags permissions)
{
int nOne = 1;
// Create socket for listening for incoming connections
struct sockaddr_storage sockaddr;
socklen_t len = sizeof(sockaddr);
if (!addrBind.GetSockAddr((struct sockaddr*)&sockaddr, &len))
{
strError = strprintf(Untranslated("Error: Bind address family for %s not supported"), addrBind.ToString());
LogPrintf("%s\n", strError.original);
return false;
}
std::unique_ptr<Sock> sock = CreateSock(addrBind);
if (!sock) {
strError = strprintf(Untranslated("Error: Couldn't open socket for incoming connections (socket returned error %s)"), NetworkErrorString(WSAGetLastError()));
LogPrintf("%s\n", strError.original);
return false;
}
// Allow binding if the port is still in TIME_WAIT state after
// the program was closed and restarted.
setsockopt(sock->Get(), SOL_SOCKET, SO_REUSEADDR, (sockopt_arg_type)&nOne, sizeof(int));
// some systems don't have IPV6_V6ONLY but are always v6only; others do have the option
// and enable it by default or not. Try to enable it, if possible.
if (addrBind.IsIPv6()) {
#ifdef IPV6_V6ONLY
setsockopt(sock->Get(), IPPROTO_IPV6, IPV6_V6ONLY, (sockopt_arg_type)&nOne, sizeof(int));
#endif
#ifdef WIN32
int nProtLevel = PROTECTION_LEVEL_UNRESTRICTED;
setsockopt(sock->Get(), IPPROTO_IPV6, IPV6_PROTECTION_LEVEL, (const char*)&nProtLevel, sizeof(int));
#endif
}
if (::bind(sock->Get(), (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
{
int nErr = WSAGetLastError();
if (nErr == WSAEADDRINUSE)
strError = strprintf(_("Unable to bind to %s on this computer. %s is probably already running."), addrBind.ToString(), PACKAGE_NAME);
else
strError = strprintf(_("Unable to bind to %s on this computer (bind returned error %s)"), addrBind.ToString(), NetworkErrorString(nErr));
LogPrintf("%s\n", strError.original);
return false;
}
LogPrintf("Bound to %s\n", addrBind.ToString());
// Listen for incoming connections
if (listen(sock->Get(), SOMAXCONN) == SOCKET_ERROR)
{
strError = strprintf(_("Error: Listening for incoming connections failed (listen returned error %s)"), NetworkErrorString(WSAGetLastError()));
LogPrintf("%s\n", strError.original);
return false;
}
vhListenSocket.push_back(ListenSocket(sock->Release(), permissions));
return true;
}
void Discover()
{
if (!fDiscover)
return;
#ifdef WIN32
// Get local host IP
char pszHostName[256] = "";
if (gethostname(pszHostName, sizeof(pszHostName)) != SOCKET_ERROR)
{
std::vector<CNetAddr> vaddr;
if (LookupHost(pszHostName, vaddr, 0, true))
{
for (const CNetAddr &addr : vaddr)
{
if (AddLocal(addr, LOCAL_IF))
LogPrintf("%s: %s - %s\n", __func__, pszHostName, addr.ToString());
}
}
}
#elif (HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS)
// Get local host ip
struct ifaddrs* myaddrs;
if (getifaddrs(&myaddrs) == 0)
{
for (struct ifaddrs* ifa = myaddrs; ifa != nullptr; ifa = ifa->ifa_next)
{
if (ifa->ifa_addr == nullptr) continue;
if ((ifa->ifa_flags & IFF_UP) == 0) continue;
if (strcmp(ifa->ifa_name, "lo") == 0) continue;
if (strcmp(ifa->ifa_name, "lo0") == 0) continue;
if (ifa->ifa_addr->sa_family == AF_INET)
{
struct sockaddr_in* s4 = (struct sockaddr_in*)(ifa->ifa_addr);
CNetAddr addr(s4->sin_addr);
if (AddLocal(addr, LOCAL_IF))
LogPrintf("%s: IPv4 %s: %s\n", __func__, ifa->ifa_name, addr.ToString());
}
else if (ifa->ifa_addr->sa_family == AF_INET6)
{
struct sockaddr_in6* s6 = (struct sockaddr_in6*)(ifa->ifa_addr);
CNetAddr addr(s6->sin6_addr);
if (AddLocal(addr, LOCAL_IF))
LogPrintf("%s: IPv6 %s: %s\n", __func__, ifa->ifa_name, addr.ToString());
}
}
freeifaddrs(myaddrs);
}
#endif
}
void CConnman::SetNetworkActive(bool active)
{
LogPrintf("%s: %s\n", __func__, active);
if (fNetworkActive == active) {
return;
}
fNetworkActive = active;
uiInterface.NotifyNetworkActiveChanged(fNetworkActive);
}
CConnman::CConnman(uint64_t nSeed0In, uint64_t nSeed1In, CAddrMan& addrman_in, bool network_active)
: addrman(addrman_in), nSeed0(nSeed0In), nSeed1(nSeed1In)
{
SetTryNewOutboundPeer(false);
Options connOptions;
Init(connOptions);
SetNetworkActive(network_active);
}
NodeId CConnman::GetNewNodeId()
{
return nLastNodeId.fetch_add(1, std::memory_order_relaxed);
}
bool CConnman::Bind(const CService &addr, unsigned int flags, NetPermissionFlags permissions) {
if (!(flags & BF_EXPLICIT) && !IsReachable(addr)) {
return false;
}
bilingual_str strError;
if (!BindListenPort(addr, strError, permissions)) {
if ((flags & BF_REPORT_ERROR) && clientInterface) {
clientInterface->ThreadSafeMessageBox(strError, "", CClientUIInterface::MSG_ERROR);
}
return false;
}
if (addr.IsRoutable() && fDiscover && !(flags & BF_DONT_ADVERTISE) && !NetPermissions::HasFlag(permissions, NetPermissionFlags::NoBan)) {
AddLocal(addr, LOCAL_BIND);
}
return true;
}
bool CConnman::InitBinds(const Options& options)
{
bool fBound = false;
for (const auto& addrBind : options.vBinds) {
fBound |= Bind(addrBind, (BF_EXPLICIT | BF_REPORT_ERROR), NetPermissionFlags::None);
}
for (const auto& addrBind : options.vWhiteBinds) {
fBound |= Bind(addrBind.m_service, (BF_EXPLICIT | BF_REPORT_ERROR), addrBind.m_flags);
}
for (const auto& addr_bind : options.onion_binds) {
fBound |= Bind(addr_bind, BF_EXPLICIT | BF_DONT_ADVERTISE, NetPermissionFlags::None);
}
if (options.bind_on_any) {
struct in_addr inaddr_any;
inaddr_any.s_addr = htonl(INADDR_ANY);
struct in6_addr inaddr6_any = IN6ADDR_ANY_INIT;
fBound |= Bind(CService(inaddr6_any, GetListenPort()), BF_NONE, NetPermissionFlags::None);
fBound |= Bind(CService(inaddr_any, GetListenPort()), !fBound ? BF_REPORT_ERROR : BF_NONE, NetPermissionFlags::None);
}
return fBound;
}
bool CConnman::Start(CScheduler& scheduler, const Options& connOptions)
{
Init(connOptions);
if (fListen && !InitBinds(connOptions)) {
if (clientInterface) {
clientInterface->ThreadSafeMessageBox(
_("Failed to listen on any port. Use -listen=0 if you want this."),
"", CClientUIInterface::MSG_ERROR);
}
return false;
}
proxyType i2p_sam;
if (GetProxy(NET_I2P, i2p_sam)) {
m_i2p_sam_session = std::make_unique<i2p::sam::Session>(gArgs.GetDataDirNet() / "i2p_private_key",
i2p_sam.proxy, &interruptNet);
}
for (const auto& strDest : connOptions.vSeedNodes) {
AddAddrFetch(strDest);
}
if (clientInterface) {
clientInterface->InitMessage(_("Loading P2P addresses…").translated);
}
// Load addresses from peers.dat
int64_t nStart = GetTimeMillis();
{
CAddrDB adb;
if (adb.Read(addrman))
LogPrintf("Loaded %i addresses from peers.dat %dms\n", addrman.size(), GetTimeMillis() - nStart);
else {
addrman.Clear(); // Addrman can be in an inconsistent state after failure, reset it
LogPrintf("Recreating peers.dat\n");
DumpAddresses();
}
}
if (m_use_addrman_outgoing) {
// Load addresses from anchors.dat
m_anchors = ReadAnchors(gArgs.GetDataDirNet() / ANCHORS_DATABASE_FILENAME);
if (m_anchors.size() > MAX_BLOCK_RELAY_ONLY_ANCHORS) {
m_anchors.resize(MAX_BLOCK_RELAY_ONLY_ANCHORS);
}
LogPrintf("%i block-relay-only anchors will be tried for connections.\n", m_anchors.size());
}
uiInterface.InitMessage(_("Starting network threads…").translated);
fAddressesInitialized = true;
if (semOutbound == nullptr) {
// initialize semaphore
semOutbound = std::make_unique<CSemaphore>(std::min(m_max_outbound, nMaxConnections));
}
if (semAddnode == nullptr) {
// initialize semaphore
semAddnode = std::make_unique<CSemaphore>(nMaxAddnode);
}
//
// Start threads
//
assert(m_msgproc);
InterruptSocks5(false);
interruptNet.reset();
flagInterruptMsgProc = false;
{
LOCK(mutexMsgProc);
fMsgProcWake = false;
}
// Send and receive from sockets, accept connections
threadSocketHandler = std::thread(&util::TraceThread, "net", [this] { ThreadSocketHandler(); });
if (!gArgs.GetBoolArg("-dnsseed", DEFAULT_DNSSEED))
LogPrintf("DNS seeding disabled\n");
else
threadDNSAddressSeed = std::thread(&util::TraceThread, "dnsseed", [this] { ThreadDNSAddressSeed(); });
// Initiate manual connections
threadOpenAddedConnections = std::thread(&util::TraceThread, "addcon", [this] { ThreadOpenAddedConnections(); });
if (connOptions.m_use_addrman_outgoing && !connOptions.m_specified_outgoing.empty()) {
if (clientInterface) {
clientInterface->ThreadSafeMessageBox(
_("Cannot provide specific connections and have addrman find outgoing connections at the same."),
"", CClientUIInterface::MSG_ERROR);
}
return false;
}
if (connOptions.m_use_addrman_outgoing || !connOptions.m_specified_outgoing.empty()) {
threadOpenConnections = std::thread(
&util::TraceThread, "opencon",
[this, connect = connOptions.m_specified_outgoing] { ThreadOpenConnections(connect); });
}
// Process messages
threadMessageHandler = std::thread(&util::TraceThread, "msghand", [this] { ThreadMessageHandler(); });
if (connOptions.m_i2p_accept_incoming && m_i2p_sam_session.get() != nullptr) {
threadI2PAcceptIncoming =
std::thread(&util::TraceThread, "i2paccept", [this] { ThreadI2PAcceptIncoming(); });
}
// Dump network addresses
scheduler.scheduleEvery([this] { DumpAddresses(); }, DUMP_PEERS_INTERVAL);
return true;
}
class CNetCleanup
{
public:
CNetCleanup() {}
~CNetCleanup()
{
#ifdef WIN32
// Shutdown Windows Sockets
WSACleanup();
#endif
}
};
static CNetCleanup instance_of_cnetcleanup;
void CConnman::Interrupt()
{
{
LOCK(mutexMsgProc);
flagInterruptMsgProc = true;
}
condMsgProc.notify_all();
interruptNet();
InterruptSocks5(true);
if (semOutbound) {
for (int i=0; i<m_max_outbound; i++) {
semOutbound->post();
}
}
if (semAddnode) {
for (int i=0; i<nMaxAddnode; i++) {
semAddnode->post();
}
}
}
void CConnman::StopThreads()
{
if (threadI2PAcceptIncoming.joinable()) {
threadI2PAcceptIncoming.join();
}
if (threadMessageHandler.joinable())
threadMessageHandler.join();
if (threadOpenConnections.joinable())
threadOpenConnections.join();
if (threadOpenAddedConnections.joinable())
threadOpenAddedConnections.join();
if (threadDNSAddressSeed.joinable())
threadDNSAddressSeed.join();
if (threadSocketHandler.joinable())
threadSocketHandler.join();
}
void CConnman::StopNodes()
{
if (fAddressesInitialized) {
DumpAddresses();
fAddressesInitialized = false;
if (m_use_addrman_outgoing) {
// Anchor connections are only dumped during clean shutdown.
std::vector<CAddress> anchors_to_dump = GetCurrentBlockRelayOnlyConns();
if (anchors_to_dump.size() > MAX_BLOCK_RELAY_ONLY_ANCHORS) {
anchors_to_dump.resize(MAX_BLOCK_RELAY_ONLY_ANCHORS);
}
DumpAnchors(gArgs.GetDataDirNet() / ANCHORS_DATABASE_FILENAME, anchors_to_dump);
}
}
// Delete peer connections.
std::vector<CNode*> nodes;
WITH_LOCK(cs_vNodes, nodes.swap(vNodes));
for (CNode* pnode : nodes) {
pnode->CloseSocketDisconnect();
DeleteNode(pnode);
}
// Close listening sockets.
for (ListenSocket& hListenSocket : vhListenSocket) {
if (hListenSocket.socket != INVALID_SOCKET) {
if (!CloseSocket(hListenSocket.socket)) {
LogPrintf("CloseSocket(hListenSocket) failed with error %s\n", NetworkErrorString(WSAGetLastError()));
}
}
}
for (CNode* pnode : vNodesDisconnected) {
DeleteNode(pnode);
}
vNodesDisconnected.clear();
vhListenSocket.clear();
semOutbound.reset();
semAddnode.reset();
}
void CConnman::DeleteNode(CNode* pnode)
{
assert(pnode);
m_msgproc->FinalizeNode(*pnode);
delete pnode;
}
CConnman::~CConnman()
{
Interrupt();
Stop();
}
std::vector<CAddress> CConnman::GetAddresses(size_t max_addresses, size_t max_pct, std::optional<Network> network) const
{
std::vector<CAddress> addresses = addrman.GetAddr(max_addresses, max_pct, network);
if (m_banman) {
addresses.erase(std::remove_if(addresses.begin(), addresses.end(),
[this](const CAddress& addr){return m_banman->IsDiscouraged(addr) || m_banman->IsBanned(addr);}),
addresses.end());
}
return addresses;
}
std::vector<CAddress> CConnman::GetAddresses(CNode& requestor, size_t max_addresses, size_t max_pct)
{
auto local_socket_bytes = requestor.addrBind.GetAddrBytes();
uint64_t cache_id = GetDeterministicRandomizer(RANDOMIZER_ID_ADDRCACHE)
.Write(requestor.addr.GetNetwork())
.Write(local_socket_bytes.data(), local_socket_bytes.size())
.Finalize();
const auto current_time = GetTime<std::chrono::microseconds>();
auto r = m_addr_response_caches.emplace(cache_id, CachedAddrResponse{});
CachedAddrResponse& cache_entry = r.first->second;
if (cache_entry.m_cache_entry_expiration < current_time) { // If emplace() added new one it has expiration 0.
cache_entry.m_addrs_response_cache = GetAddresses(max_addresses, max_pct, /* network */ std::nullopt);
// Choosing a proper cache lifetime is a trade-off between the privacy leak minimization
// and the usefulness of ADDR responses to honest users.
//
// Longer cache lifetime makes it more difficult for an attacker to scrape
// enough AddrMan data to maliciously infer something useful.
// By the time an attacker scraped enough AddrMan records, most of
// the records should be old enough to not leak topology info by
// e.g. analyzing real-time changes in timestamps.
//
// It takes only several hundred requests to scrape everything from an AddrMan containing 100,000 nodes,
// so ~24 hours of cache lifetime indeed makes the data less inferable by the time
// most of it could be scraped (considering that timestamps are updated via
// ADDR self-announcements and when nodes communicate).
// We also should be robust to those attacks which may not require scraping *full* victim's AddrMan
// (because even several timestamps of the same handful of nodes may leak privacy).
//
// On the other hand, longer cache lifetime makes ADDR responses
// outdated and less useful for an honest requestor, e.g. if most nodes
// in the ADDR response are no longer active.
//
// However, the churn in the network is known to be rather low. Since we consider
// nodes to be "terrible" (see IsTerrible()) if the timestamps are older than 30 days,
// max. 24 hours of "penalty" due to cache shouldn't make any meaningful difference
// in terms of the freshness of the response.
cache_entry.m_cache_entry_expiration = current_time + std::chrono::hours(21) + GetRandMillis(std::chrono::hours(6));
}
return cache_entry.m_addrs_response_cache;
}
bool CConnman::AddNode(const std::string& strNode)
{
LOCK(cs_vAddedNodes);
for (const std::string& it : vAddedNodes) {
if (strNode == it) return false;
}
vAddedNodes.push_back(strNode);
return true;
}
bool CConnman::RemoveAddedNode(const std::string& strNode)
{
LOCK(cs_vAddedNodes);
for(std::vector<std::string>::iterator it = vAddedNodes.begin(); it != vAddedNodes.end(); ++it) {
if (strNode == *it) {
vAddedNodes.erase(it);
return true;
}
}
return false;
}
size_t CConnman::GetNodeCount(ConnectionDirection flags) const
{
LOCK(cs_vNodes);
if (flags == ConnectionDirection::Both) // Shortcut if we want total
return vNodes.size();
int nNum = 0;
for (const auto& pnode : vNodes) {
if (flags & (pnode->IsInboundConn() ? ConnectionDirection::In : ConnectionDirection::Out)) {
nNum++;
}
}
return nNum;
}
void CConnman::GetNodeStats(std::vector<CNodeStats>& vstats) const
{
vstats.clear();
LOCK(cs_vNodes);
vstats.reserve(vNodes.size());
for (CNode* pnode : vNodes) {
vstats.emplace_back();
pnode->copyStats(vstats.back(), addrman.m_asmap);
}
}
bool CConnman::DisconnectNode(const std::string& strNode)
{
LOCK(cs_vNodes);
if (CNode* pnode = FindNode(strNode)) {
LogPrint(BCLog::NET, "disconnect by address%s matched peer=%d; disconnecting\n", (fLogIPs ? strprintf("=%s", strNode) : ""), pnode->GetId());
pnode->fDisconnect = true;
return true;
}
return false;
}
bool CConnman::DisconnectNode(const CSubNet& subnet)
{
bool disconnected = false;
LOCK(cs_vNodes);
for (CNode* pnode : vNodes) {
if (subnet.Match(pnode->addr)) {
LogPrint(BCLog::NET, "disconnect by subnet%s matched peer=%d; disconnecting\n", (fLogIPs ? strprintf("=%s", subnet.ToString()) : ""), pnode->GetId());
pnode->fDisconnect = true;
disconnected = true;
}
}
return disconnected;
}
bool CConnman::DisconnectNode(const CNetAddr& addr)
{
return DisconnectNode(CSubNet(addr));
}
bool CConnman::DisconnectNode(NodeId id)
{
LOCK(cs_vNodes);
for(CNode* pnode : vNodes) {
if (id == pnode->GetId()) {
LogPrint(BCLog::NET, "disconnect by id peer=%d; disconnecting\n", pnode->GetId());
pnode->fDisconnect = true;
return true;
}
}
return false;
}
void CConnman::RecordBytesRecv(uint64_t bytes)
{
LOCK(cs_totalBytesRecv);
nTotalBytesRecv += bytes;
}
void CConnman::RecordBytesSent(uint64_t bytes)
{
LOCK(cs_totalBytesSent);
nTotalBytesSent += bytes;
const auto now = GetTime<std::chrono::seconds>();
if (nMaxOutboundCycleStartTime + MAX_UPLOAD_TIMEFRAME < now)
{
// timeframe expired, reset cycle
nMaxOutboundCycleStartTime = now;
nMaxOutboundTotalBytesSentInCycle = 0;
}
// TODO, exclude peers with download permission
nMaxOutboundTotalBytesSentInCycle += bytes;
}
uint64_t CConnman::GetMaxOutboundTarget() const
{
LOCK(cs_totalBytesSent);
return nMaxOutboundLimit;
}
std::chrono::seconds CConnman::GetMaxOutboundTimeframe() const
{
return MAX_UPLOAD_TIMEFRAME;
}
std::chrono::seconds CConnman::GetMaxOutboundTimeLeftInCycle() const
{
LOCK(cs_totalBytesSent);
if (nMaxOutboundLimit == 0)
return 0s;
if (nMaxOutboundCycleStartTime.count() == 0)
return MAX_UPLOAD_TIMEFRAME;
const std::chrono::seconds cycleEndTime = nMaxOutboundCycleStartTime + MAX_UPLOAD_TIMEFRAME;
const auto now = GetTime<std::chrono::seconds>();
return (cycleEndTime < now) ? 0s : cycleEndTime - now;
}
bool CConnman::OutboundTargetReached(bool historicalBlockServingLimit) const
{
LOCK(cs_totalBytesSent);
if (nMaxOutboundLimit == 0)
return false;
if (historicalBlockServingLimit)
{
// keep a large enough buffer to at least relay each block once
const std::chrono::seconds timeLeftInCycle = GetMaxOutboundTimeLeftInCycle();
const uint64_t buffer = timeLeftInCycle / std::chrono::minutes{10} * MAX_BLOCK_SERIALIZED_SIZE;
if (buffer >= nMaxOutboundLimit || nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit - buffer)
return true;
}
else if (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit)
return true;
return false;
}
uint64_t CConnman::GetOutboundTargetBytesLeft() const
{
LOCK(cs_totalBytesSent);
if (nMaxOutboundLimit == 0)
return 0;
return (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) ? 0 : nMaxOutboundLimit - nMaxOutboundTotalBytesSentInCycle;
}
uint64_t CConnman::GetTotalBytesRecv() const
{
LOCK(cs_totalBytesRecv);
return nTotalBytesRecv;
}
uint64_t CConnman::GetTotalBytesSent() const
{
LOCK(cs_totalBytesSent);
return nTotalBytesSent;
}
ServiceFlags CConnman::GetLocalServices() const
{
return nLocalServices;
}
unsigned int CConnman::GetReceiveFloodSize() const { return nReceiveFloodSize; }
CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, SOCKET hSocketIn, const CAddress& addrIn, uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn, const CAddress& addrBindIn, const std::string& addrNameIn, ConnectionType conn_type_in, bool inbound_onion)
: nTimeConnected(GetTimeSeconds()),
addr(addrIn),
addrBind(addrBindIn),
m_inbound_onion(inbound_onion),
nKeyedNetGroup(nKeyedNetGroupIn),
id(idIn),
nLocalHostNonce(nLocalHostNonceIn),
m_conn_type(conn_type_in),
nLocalServices(nLocalServicesIn)
{
if (inbound_onion) assert(conn_type_in == ConnectionType::INBOUND);
hSocket = hSocketIn;
addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
if (conn_type_in != ConnectionType::BLOCK_RELAY) {
m_tx_relay = std::make_unique<TxRelay>();
}
for (const std::string &msg : getAllNetMessageTypes())
mapRecvBytesPerMsgCmd[msg] = 0;
mapRecvBytesPerMsgCmd[NET_MESSAGE_COMMAND_OTHER] = 0;
if (fLogIPs) {
LogPrint(BCLog::NET, "Added connection to %s peer=%d\n", addrName, id);
} else {
LogPrint(BCLog::NET, "Added connection peer=%d\n", id);
}
m_deserializer = std::make_unique<V1TransportDeserializer>(V1TransportDeserializer(Params(), GetId(), SER_NETWORK, INIT_PROTO_VERSION));
m_serializer = std::make_unique<V1TransportSerializer>(V1TransportSerializer());
}
CNode::~CNode()
{
CloseSocket(hSocket);
}
bool CConnman::NodeFullyConnected(const CNode* pnode)
{
return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect;
}
void CConnman::PushMessage(CNode* pnode, CSerializedNetMsg&& msg)
{
size_t nMessageSize = msg.data.size();
LogPrint(BCLog::NET, "sending %s (%d bytes) peer=%d\n", msg.m_type, nMessageSize, pnode->GetId());
if (gArgs.GetBoolArg("-capturemessages", false)) {
CaptureMessage(pnode->addr, msg.m_type, msg.data, /* incoming */ false);
}
TRACE6(net, outbound_message,
pnode->GetId(),
pnode->GetAddrName().c_str(),
pnode->ConnectionTypeAsString().c_str(),
msg.m_type.c_str(),
msg.data.size(),
msg.data.data()
);
// make sure we use the appropriate network transport format
std::vector<unsigned char> serializedHeader;
pnode->m_serializer->prepareForTransport(msg, serializedHeader);
size_t nTotalSize = nMessageSize + serializedHeader.size();
size_t nBytesSent = 0;
{
LOCK(pnode->cs_vSend);
bool optimisticSend(pnode->vSendMsg.empty());
//log total amount of bytes per message type
pnode->mapSendBytesPerMsgCmd[msg.m_type] += nTotalSize;
pnode->nSendSize += nTotalSize;
if (pnode->nSendSize > nSendBufferMaxSize) pnode->fPauseSend = true;
pnode->vSendMsg.push_back(std::move(serializedHeader));
if (nMessageSize) pnode->vSendMsg.push_back(std::move(msg.data));
// If write queue empty, attempt "optimistic write"
if (optimisticSend) nBytesSent = SocketSendData(*pnode);
}
if (nBytesSent) RecordBytesSent(nBytesSent);
}
bool CConnman::ForNode(NodeId id, std::function<bool(CNode* pnode)> func)
{
CNode* found = nullptr;
LOCK(cs_vNodes);
for (auto&& pnode : vNodes) {
if(pnode->GetId() == id) {
found = pnode;
break;
}
}
return found != nullptr && NodeFullyConnected(found) && func(found);
}
std::chrono::microseconds CConnman::PoissonNextSendInbound(std::chrono::microseconds now, std::chrono::seconds average_interval)
{
if (m_next_send_inv_to_incoming.load() < now) {
// If this function were called from multiple threads simultaneously
// it would possible that both update the next send variable, and return a different result to their caller.
// This is not possible in practice as only the net processing thread invokes this function.
m_next_send_inv_to_incoming = PoissonNextSend(now, average_interval);
}
return m_next_send_inv_to_incoming;
}
std::chrono::microseconds PoissonNextSend(std::chrono::microseconds now, std::chrono::seconds average_interval)
{
double unscaled = -log1p(GetRand(1ULL << 48) * -0.0000000000000035527136788 /* -1/2^48 */);
return now + std::chrono::duration_cast<std::chrono::microseconds>(unscaled * average_interval + 0.5us);
}
CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const
{
return CSipHasher(nSeed0, nSeed1).Write(id);
}
uint64_t CConnman::CalculateKeyedNetGroup(const CAddress& ad) const
{
std::vector<unsigned char> vchNetGroup(ad.GetGroup(addrman.m_asmap));
return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP).Write(vchNetGroup.data(), vchNetGroup.size()).Finalize();
}
void CaptureMessage(const CAddress& addr, const std::string& msg_type, const Span<const unsigned char>& data, bool is_incoming)
{
// Note: This function captures the message at the time of processing,
// not at socket receive/send time.
// This ensures that the messages are always in order from an application
// layer (processing) perspective.
auto now = GetTime<std::chrono::microseconds>();
// Windows folder names can not include a colon
std::string clean_addr = addr.ToString();
std::replace(clean_addr.begin(), clean_addr.end(), ':', '_');
fs::path base_path = gArgs.GetDataDirNet() / "message_capture" / clean_addr;
fs::create_directories(base_path);
fs::path path = base_path / (is_incoming ? "msgs_recv.dat" : "msgs_sent.dat");
CAutoFile f(fsbridge::fopen(path, "ab"), SER_DISK, CLIENT_VERSION);
ser_writedata64(f, now.count());
f.write(msg_type.data(), msg_type.length());
for (auto i = msg_type.length(); i < CMessageHeader::COMMAND_SIZE; ++i) {
f << uint8_t{'\0'};
}
uint32_t size = data.size();
ser_writedata32(f, size);
f.write((const char*)data.data(), data.size());
}