Merge bitcoin/bitcoin#23042: net: Avoid logging AlreadyHaveTx when disconnecting misbehaving peer

fa2662c net: Avoid logging AlreadyHaveTx when disconnecting misbehaving peer (MarcoFalke)

Pull request description:

  There is no need to log `AlreadyHaveTx` for an inv when a peer is marked for disconnection due to sending that inv. In fact, I find it confusing that a `block-relay-only` connection calls `AlreadyHaveTx` at all. Also there is no need to call `AddKnownTx` when the peer is marked for disconnection.

ACKs for top commit:
  naumenkogs:
    ACK fa2662c
  jnewbery:
    Code review ACK fa2662c
  dunxen:
    Concept and code review ACK fa2662c

Tree-SHA512: 9996b807a824021f992b5281d82ff0cbbe6a442c2fedf7dfd6adda64ccc5e0ef4fb0ff91ab75086f975837bbbb7a5934ac7e671a80dcababa7203c92fc0c7f84

Author: fanquake

src/net_processing.cpp

@@ -2960,16 +2960,17 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
                     best_block = &inv.hash;
                 }
             } else if (inv.IsGenTxMsg()) {
+                if (reject_tx_invs) {
+                    LogPrint(BCLog::NET, "transaction (%s) inv sent in violation of protocol, disconnecting peer=%d\n", inv.hash.ToString(), pfrom.GetId());
+                    pfrom.fDisconnect = true;
+                    return;
+                }
                 const GenTxid gtxid = ToGenTxid(inv);
                 const bool fAlreadyHave = AlreadyHaveTx(gtxid);
                 LogPrint(BCLog::NET, "got inv: %s  %s peer=%d\n", inv.ToString(), fAlreadyHave ? "have" : "new", pfrom.GetId());
 
                 pfrom.AddKnownTx(inv.hash);
-                if (reject_tx_invs) {
-                    LogPrint(BCLog::NET, "transaction (%s) inv sent in violation of protocol, disconnecting peer=%d\n", inv.hash.ToString(), pfrom.GetId());
-                    pfrom.fDisconnect = true;
-                    return;
-                } else if (!fAlreadyHave && !m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
+                if (!fAlreadyHave && !m_chainman.ActiveChainstate().IsInitialBlockDownload()) {
                     AddTxAnnouncement(pfrom, gtxid, current_time);
                 }
             } else {