Bucket for inbound when scheduling invs to hide tx time

This commit is contained in:
Gleb 2018-05-21 12:02:40 -07:00 committed by User
parent 287e4edc2f
commit d45b344ffd
4 changed files with 45 additions and 19 deletions

View file

@ -2864,8 +2864,20 @@ bool CConnman::ForNode(NodeId id, std::function<bool(CNode* pnode)> func)
return found != nullptr && NodeFullyConnected(found) && func(found); return found != nullptr && NodeFullyConnected(found) && func(found);
} }
int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds) { int64_t CConnman::PoissonNextSendInbound(int64_t now, int average_interval_seconds)
return nNow + (int64_t)(log1p(GetRand(1ULL << 48) * -0.0000000000000035527136788 /* -1/2^48 */) * average_interval_seconds * -1000000.0 + 0.5); {
if (m_next_send_inv_to_incoming < 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_seconds);
}
return m_next_send_inv_to_incoming;
}
int64_t PoissonNextSend(int64_t now, int average_interval_seconds)
{
return now + (int64_t)(log1p(GetRand(1ULL << 48) * -0.0000000000000035527136788 /* -1/2^48 */) * average_interval_seconds * -1000000.0 + 0.5);
} }
CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const

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@ -310,6 +310,13 @@ public:
unsigned int GetReceiveFloodSize() const; unsigned int GetReceiveFloodSize() const;
void WakeMessageHandler(); void WakeMessageHandler();
/** Attempts to obfuscate tx time through exponentially distributed emitting.
Works assuming that a single interval is used.
Variable intervals will result in privacy decrease.
*/
int64_t PoissonNextSendInbound(int64_t now, int average_interval_seconds);
private: private:
struct ListenSocket { struct ListenSocket {
SOCKET socket; SOCKET socket;
@ -434,6 +441,8 @@ private:
* This takes the place of a feeler connection */ * This takes the place of a feeler connection */
std::atomic_bool m_try_another_outbound_peer; std::atomic_bool m_try_another_outbound_peer;
std::atomic<int64_t> m_next_send_inv_to_incoming;
friend struct CConnmanTest; friend struct CConnmanTest;
}; };
extern std::unique_ptr<CConnman> g_connman; extern std::unique_ptr<CConnman> g_connman;
@ -863,6 +872,6 @@ public:
/** Return a timestamp in the future (in microseconds) for exponentially distributed events. */ /** Return a timestamp in the future (in microseconds) for exponentially distributed events. */
int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds); int64_t PoissonNextSend(int64_t now, int average_interval_seconds);
#endif // BITCOIN_NET_H #endif // BITCOIN_NET_H

View file

@ -71,6 +71,21 @@ static const int STALE_RELAY_AGE_LIMIT = 30 * 24 * 60 * 60;
/// limiting block relay. Set to one week, denominated in seconds. /// limiting block relay. Set to one week, denominated in seconds.
static const int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60; static const int HISTORICAL_BLOCK_AGE = 7 * 24 * 60 * 60;
/** Average delay between local address broadcasts in seconds. */
static constexpr unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 60 * 60;
/** Average delay between peer address broadcasts in seconds. */
static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
/** Average delay between trickled inventory transmissions in seconds.
* Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
static const unsigned int INVENTORY_BROADCAST_INTERVAL = 5;
/** Maximum number of inventory items to send per transmission.
* Limits the impact of low-fee transaction floods. */
static constexpr unsigned int INVENTORY_BROADCAST_MAX = 7 * INVENTORY_BROADCAST_INTERVAL;
/** Average delay between feefilter broadcasts in seconds. */
static constexpr unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL = 10 * 60;
/** Maximum feefilter broadcast delay after significant change. */
static constexpr unsigned int MAX_FEEFILTER_CHANGE_DELAY = 5 * 60;
// Internal stuff // Internal stuff
namespace { namespace {
/** Number of nodes with fSyncStarted. */ /** Number of nodes with fSyncStarted. */
@ -3496,8 +3511,12 @@ bool PeerLogicValidation::SendMessages(CNode* pto, std::atomic<bool>& interruptM
bool fSendTrickle = pto->fWhitelisted; bool fSendTrickle = pto->fWhitelisted;
if (pto->nNextInvSend < nNow) { if (pto->nNextInvSend < nNow) {
fSendTrickle = true; fSendTrickle = true;
// Use half the delay for outbound peers, as there is less privacy concern for them. if (pto->fInbound) {
pto->nNextInvSend = PoissonNextSend(nNow, INVENTORY_BROADCAST_INTERVAL >> !pto->fInbound); pto->nNextInvSend = connman->PoissonNextSendInbound(nNow, INVENTORY_BROADCAST_INTERVAL);
} else {
// Use half the delay for outbound peers, as there is less privacy concern for them.
pto->nNextInvSend = PoissonNextSend(nNow, INVENTORY_BROADCAST_INTERVAL >> 1);
}
} }
// Time to send but the peer has requested we not relay transactions. // Time to send but the peer has requested we not relay transactions.

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@ -104,20 +104,6 @@ static const unsigned int DATABASE_WRITE_INTERVAL = 60 * 60;
static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60; static const unsigned int DATABASE_FLUSH_INTERVAL = 24 * 60 * 60;
/** Maximum length of reject messages. */ /** Maximum length of reject messages. */
static const unsigned int MAX_REJECT_MESSAGE_LENGTH = 111; static const unsigned int MAX_REJECT_MESSAGE_LENGTH = 111;
/** Average delay between local address broadcasts in seconds. */
static const unsigned int AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL = 24 * 60 * 60;
/** Average delay between peer address broadcasts in seconds. */
static const unsigned int AVG_ADDRESS_BROADCAST_INTERVAL = 30;
/** Average delay between trickled inventory transmissions in seconds.
* Blocks and whitelisted receivers bypass this, outbound peers get half this delay. */
static const unsigned int INVENTORY_BROADCAST_INTERVAL = 5;
/** Maximum number of inventory items to send per transmission.
* Limits the impact of low-fee transaction floods. */
static const unsigned int INVENTORY_BROADCAST_MAX = 7 * INVENTORY_BROADCAST_INTERVAL;
/** Average delay between feefilter broadcasts in seconds. */
static const unsigned int AVG_FEEFILTER_BROADCAST_INTERVAL = 10 * 60;
/** Maximum feefilter broadcast delay after significant change. */
static const unsigned int MAX_FEEFILTER_CHANGE_DELAY = 5 * 60;
/** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */ /** Block download timeout base, expressed in millionths of the block interval (i.e. 10 min) */
static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE = 1000000; static const int64_t BLOCK_DOWNLOAD_TIMEOUT_BASE = 1000000;
/** Additional block download timeout per parallel downloading peer (i.e. 5 min) */ /** Additional block download timeout per parallel downloading peer (i.e. 5 min) */