From fb4265747c9eb022d80c6f2988e574c689130348 Mon Sep 17 00:00:00 2001
From: Jon Atack <jon@atack.com>
Date: Fri, 14 Jul 2023 10:48:30 -0600
Subject: [PATCH] Add and use CNetAddr::HasCJDNSPrefix() helper

---
 src/net.cpp        | 2 +-
 src/netaddress.cpp | 3 +--
 src/netaddress.h   | 1 +
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/net.cpp b/src/net.cpp
index 654e0ac9fd..d76874b233 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -275,7 +275,7 @@ std::optional<CService> GetLocalAddrForPeer(CNode& node)
 CService MaybeFlipIPv6toCJDNS(const CService& service)
 {
     CService ret{service};
-    if (ret.m_net == NET_IPV6 && ret.m_addr[0] == 0xfc && IsReachable(NET_CJDNS)) {
+    if (ret.m_net == NET_IPV6 && ret.HasCJDNSPrefix() && IsReachable(NET_CJDNS)) {
         ret.m_net = NET_CJDNS;
     }
     return ret;
diff --git a/src/netaddress.cpp b/src/netaddress.cpp
index 4758f24680..8196a6a48c 100644
--- a/src/netaddress.cpp
+++ b/src/netaddress.cpp
@@ -450,8 +450,7 @@ bool CNetAddr::IsValid() const
         return false;
     }
 
-    // CJDNS addresses always start with 0xfc
-    if (IsCJDNS() && (m_addr[0] != 0xFC)) {
+    if (IsCJDNS() && !HasCJDNSPrefix()) {
         return false;
     }
 
diff --git a/src/netaddress.h b/src/netaddress.h
index 36dc886406..5e67d843e2 100644
--- a/src/netaddress.h
+++ b/src/netaddress.h
@@ -182,6 +182,7 @@ public:
     bool IsTor() const;
     bool IsI2P() const;
     bool IsCJDNS() const;
+    [[nodiscard]] bool HasCJDNSPrefix() const { return m_addr[0] == 0xfc; }
     bool IsLocal() const;
     bool IsRoutable() const;
     bool IsInternal() const;