From 83f8821a6f41854edd5c0b11deabba658890cde1 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Tue, 15 Dec 2020 09:56:53 -0800
Subject: [PATCH 1/2] refactor: add IsAddrCompatible() to CNode

---
 src/net.h | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/net.h b/src/net.h
index 20e356562b..d7415d3f9f 100644
--- a/src/net.h
+++ b/src/net.h
@@ -1176,18 +1176,23 @@ public:
         m_addr_known->insert(_addr.GetKey());
     }
 
+    /**
+     * Whether the peer supports the address. For example, a peer that does not
+     * implement BIP155 cannot receive Tor v3 addresses because it requires
+     * ADDRv2 (BIP155) encoding.
+     */
+    bool IsAddrCompatible(const CAddress& addr) const
+    {
+        return m_wants_addrv2 || addr.IsAddrV1Compatible();
+    }
+
     void PushAddress(const CAddress& _addr, FastRandomContext &insecure_rand)
     {
-        // Whether the peer supports the address in `_addr`. For example,
-        // nodes that do not implement BIP155 cannot receive Tor v3 addresses
-        // because they require ADDRv2 (BIP155) encoding.
-        const bool addr_format_supported = m_wants_addrv2 || _addr.IsAddrV1Compatible();
-
         // Known checking here is only to save space from duplicates.
         // SendMessages will filter it again for knowns that were added
         // after addresses were pushed.
         assert(m_addr_known);
-        if (_addr.IsValid() && !m_addr_known->contains(_addr.GetKey()) && addr_format_supported) {
+        if (_addr.IsValid() && !m_addr_known->contains(_addr.GetKey()) && IsAddrCompatible(_addr)) {
             if (vAddrToSend.size() >= MAX_ADDR_TO_SEND) {
                 vAddrToSend[insecure_rand.randrange(vAddrToSend.size())] = _addr;
             } else {

From 37fe80e6267094f6051ccf9bec0c7f1a6b9e15da Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Tue, 15 Dec 2020 09:57:23 -0800
Subject: [PATCH 2/2] Only consider addrv2 peers for relay of non-addrv1
 addresses

---
 src/net_processing.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 05e5681df3..a33c4a0bd4 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1443,8 +1443,8 @@ static void RelayAddress(const CNode& originator,
     std::array<std::pair<uint64_t, CNode*>,2> best{{{0, nullptr}, {0, nullptr}}};
     assert(nRelayNodes <= best.size());
 
-    auto sortfunc = [&best, &hasher, nRelayNodes, &originator](CNode* pnode) {
-        if (pnode->RelayAddrsWithConn() && pnode != &originator) {
+    auto sortfunc = [&best, &hasher, nRelayNodes, &originator, &addr](CNode* pnode) {
+        if (pnode->RelayAddrsWithConn() && pnode != &originator && pnode->IsAddrCompatible(addr)) {
             uint64_t hashKey = CSipHasher(hasher).Write(pnode->GetId()).Finalize();
             for (unsigned int i = 0; i < nRelayNodes; i++) {
                  if (hashKey > best[i].first) {