From 5d1b8f1725f5c65a170feb44d182f9016caa9709 Mon Sep 17 00:00:00 2001
From: Gregory Maxwell <greg@xiph.org>
Date: Wed, 1 Feb 2012 18:08:03 -0500
Subject: [PATCH] Avoid advertising the node's address when it is not listening
 or IsInitialBlockDownload().
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This also avoids flushing setAddrKnown until 24 hours has passed,
and avoids contacting the external IP services when not listening.

Advertising non-listening nodes is just addr message spam.
It doesn't help the network, in fact it hurts the network,
and it also hurts user's privacy.

Advertising far out of sync nodes doesn't help the network—
they can't even forward (most) transactions and wastes nodes
outbound slots.
---
 src/main.cpp | 12 +++++++-----
 src/net.cpp  |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index 60374c0408..f0e5183e98 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2107,7 +2107,8 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
         if (!pfrom->fInbound)
         {
             // Advertise our address
-            if (addrLocalHost.IsRoutable() && !fUseProxy)
+            if (!fNoListen && !fUseProxy && addrLocalHost.IsRoutable() &&
+                !IsInitialBlockDownload())
             {
                 CAddress addr(addrLocalHost);
                 addr.nTime = GetAdjustedTime();
@@ -2703,18 +2704,18 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
 
         // Address refresh broadcast
         static int64 nLastRebroadcast;
-        if (GetTime() - nLastRebroadcast > 24 * 60 * 60)
+        if (!IsInitialBlockDownload() && (GetTime() - nLastRebroadcast > 24 * 60 * 60))
         {
-            nLastRebroadcast = GetTime();
             CRITICAL_BLOCK(cs_vNodes)
             {
                 BOOST_FOREACH(CNode* pnode, vNodes)
                 {
                     // Periodically clear setAddrKnown to allow refresh broadcasts
-                    pnode->setAddrKnown.clear();
+                    if (nLastRebroadcast)
+                        pnode->setAddrKnown.clear();
 
                     // Rebroadcast our address
-                    if (addrLocalHost.IsRoutable() && !fUseProxy)
+                    if (!fNoListen && !fUseProxy && addrLocalHost.IsRoutable())
                     {
                         CAddress addr(addrLocalHost);
                         addr.nTime = GetAdjustedTime();
@@ -2722,6 +2723,7 @@ bool SendMessages(CNode* pto, bool fSendTrickle)
                     }
                 }
             }
+            nLastRebroadcast = GetTime();
         }
 
         // Clear out old addresses periodically so it's not too much work at once
diff --git a/src/net.cpp b/src/net.cpp
index 66c9218cd0..a7eaaaceb6 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -141,7 +141,7 @@ bool GetMyExternalIP(CNetAddr& ipRet)
     const char* pszGet;
     const char* pszKeyword;
 
-    if (fUseProxy)
+    if (fNoListen||fUseProxy)
         return false;
 
     for (int nLookup = 0; nLookup <= 1; nLookup++)