Do not answer GETDATA for to-be-announced tx

sipa · sipa · commit 2896c412fadb · 2020-05-12T15:33:18.000-07:00
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
@@ -1609,8 +1609,16 @@ void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, c
 }
 
 //! Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed).
-CTransactionRef static FindTxForGetData(const uint256& txid, const std::chrono::seconds mempool_req, const std::chrono::seconds longlived_mempool_time) LOCKS_EXCLUDED(cs_main)
+CTransactionRef static FindTxForGetData(CNode* peer, const uint256& txid, const std::chrono::seconds mempool_req, const std::chrono::seconds longlived_mempool_time) LOCKS_EXCLUDED(cs_main)
 {
+    // Check if the requested transaction is so recent that we're just
+    // about to announce it to the peer; if so, they certainly shouldn't
+    // know we already have it.
+    {
+        LOCK(peer->m_tx_relay->cs_tx_inventory);
+        if (peer->m_tx_relay->setInventoryTxToSend.count(txid)) return {};
+    }
+
     {
         LOCK(cs_main);
         // Look up transaction in relay pool
@@ -1661,7 +1669,7 @@ void static ProcessGetData(CNode* pfrom, const CChainParams& chainparams, CConnm
             continue;
         }
 
-        CTransactionRef tx = FindTxForGetData(inv.hash, mempool_req, longlived_mempool_time);
+        CTransactionRef tx = FindTxForGetData(pfrom, inv.hash, mempool_req, longlived_mempool_time);
         if (tx) {
             int nSendFlags = (inv.type == MSG_TX ? SERIALIZE_TRANSACTION_NO_WITNESS : 0);
             connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *tx));

Original file line number	Diff line number	Diff line change
`@@ -1609,8 +1609,16 @@ void static ProcessGetBlockData(CNode* pfrom, const CChainParams& chainparams, c`
`1609`	`1609`	`}`
`1610`	`1610`
`1611`	`1611`	`//! Determine whether or not a peer can request a transaction, and return it (or nullptr if not found or not allowed).`
`1612`		`-CTransactionRef static FindTxForGetData(const uint256& txid, const std::chrono::seconds mempool_req, const std::chrono::seconds longlived_mempool_time) LOCKS_EXCLUDED(cs_main)`
	`1612`	`+CTransactionRef static FindTxForGetData(CNode* peer, const uint256& txid, const std::chrono::seconds mempool_req, const std::chrono::seconds longlived_mempool_time) LOCKS_EXCLUDED(cs_main)`
`1613`	`1613`	`{`
	`1614`	`+ // Check if the requested transaction is so recent that we're just`
	`1615`	`+ // about to announce it to the peer; if so, they certainly shouldn't`
	`1616`	`+ // know we already have it.`
	`1617`	`+ {`
	`1618`	`+ LOCK(peer->m_tx_relay->cs_tx_inventory);`
	`1619`	`+ if (peer->m_tx_relay->setInventoryTxToSend.count(txid)) return {};`
	`1620`	`+ }`
	`1621`	`+`
`1614`	`1622`	`{`
`1615`	`1623`	`LOCK(cs_main);`
`1616`	`1624`	`// Look up transaction in relay pool`
`@@ -1661,7 +1669,7 @@ void static ProcessGetData(CNode* pfrom, const CChainParams& chainparams, CConnm`
`1661`	`1669`	`continue;`
`1662`	`1670`	`}`
`1663`	`1671`
`1664`		`- CTransactionRef tx = FindTxForGetData(inv.hash, mempool_req, longlived_mempool_time);`
	`1672`	`+ CTransactionRef tx = FindTxForGetData(pfrom, inv.hash, mempool_req, longlived_mempool_time);`
`1665`	`1673`	`if (tx) {`
`1666`	`1674`	`int nSendFlags = (inv.type == MSG_TX ? SERIALIZE_TRANSACTION_NO_WITNESS : 0);`
`1667`	`1675`	`connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::TX, *tx));`