net: move MaybeFlipIPv6toCJDNS() from net to netbase

It need not be in the `net` module and we need to call it from
`LookupSubNet()`, thus move it to `netbase`.

Author: vasild

src/net.cpp

@@ -269,22 +269,6 @@ std::optional<CService> GetLocalAddrForPeer(CNode& node)
     return std::nullopt;
 }
 
-/**
- * If an IPv6 address belongs to the address range used by the CJDNS network and
- * the CJDNS network is reachable (-cjdnsreachable config is set), then change
- * the type from NET_IPV6 to NET_CJDNS.
- * @param[in] service Address to potentially convert.
- * @return a copy of `service` either unmodified or changed to CJDNS.
- */
-CService MaybeFlipIPv6toCJDNS(const CService& service)
-{
-    CService ret{service};
-    if (ret.IsIPv6() && ret.HasCJDNSPrefix() && g_reachable_nets.Contains(NET_CJDNS)) {
-        ret.m_net = NET_CJDNS;
-    }
-    return ret;
-}
-
 // learn a new local address
 bool AddLocal(const CService& addr_, int nScore)
 {

src/net.h

@@ -166,8 +166,6 @@ void RemoveLocal(const CService& addr);
 bool SeenLocal(const CService& addr);
 bool IsLocal(const CService& addr);
 CService GetLocalAddress(const CNode& peer);
-CService MaybeFlipIPv6toCJDNS(const CService& service);
-
 
 extern bool fDiscover;
 extern bool fListen;

src/netbase.cpp

@@ -774,3 +774,12 @@ bool IsBadPort(uint16_t port)
     }
     return false;
 }
+
+CService MaybeFlipIPv6toCJDNS(const CService& service)
+{
+    CService ret{service};
+    if (ret.IsIPv6() && ret.HasCJDNSPrefix() && g_reachable_nets.Contains(NET_CJDNS)) {
+        ret.m_net = NET_CJDNS;
+    }
+    return ret;
+}

src/netbase.h

@@ -307,4 +307,13 @@ bool Socks5(const std::string& strDest, uint16_t port, const ProxyCredentials* a
  */
 bool IsBadPort(uint16_t port);
 
+/**
+ * If an IPv6 address belongs to the address range used by the CJDNS network and
+ * the CJDNS network is reachable (-cjdnsreachable config is set), then change
+ * the type from NET_IPV6 to NET_CJDNS.
+ * @param[in] service Address to potentially convert.
+ * @return a copy of `service` either unmodified or changed to CJDNS.
+ */
+CService MaybeFlipIPv6toCJDNS(const CService& service);
+
 #endif // BITCOIN_NETBASE_H