Limited relaying/storing of foreign addresses

Introduce a boolean variable for each "network" (ipv4, ipv6, tor, i2p),
and track whether we are likely to able to connect to it. Addresses in
"addr" messages outside of our network get limited relaying and are not
stored in addrman.

1 files changed, 12 insertions, 2 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 75c8bbaba..d407e6642 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -45,8 +45,9 @@ bool OpenNetworkConnection(const CAddress& addrConnect, const char *strDest = NU
 bool fClient = false;
 static bool fUseUPnP = false;
 uint64 nLocalServices = (fClient ? 0 : NODE_NETWORK);
-CCriticalSection cs_mapLocalHost;
-map<CNetAddr, int> mapLocalHost;
+static CCriticalSection cs_mapLocalHost;
+static map<CNetAddr, int> mapLocalHost;
+static bool vfReachable[NET_MAX] = {};
 static CNode* pnodeLocalHost = NULL;
 uint64 nLocalHostNonce = 0;
 array<int, THREAD_MAX> vnThreadsRunning;
@@ -214,6 +215,9 @@ bool AddLocal(const CNetAddr& addr, int nScore)
     {
         LOCK(cs_mapLocalHost);
         mapLocalHost[addr] = std::max(nScore, mapLocalHost[addr]) + (mapLocalHost.count(addr) ? 1 : 0);
+        enum Network net = addr.GetNetwork();
+        vfReachable[net] = true;
+        if (net == NET_IPV6) vfReachable[NET_IPV4] = true;
     }
 
     AdvertizeLocal();
@@ -243,6 +247,12 @@ bool IsLocal(const CNetAddr& addr)
     return mapLocalHost.count(addr) > 0;
 }
 
+// check whether a given address is in a network we can probably connect to
+bool IsReachable(const CNetAddr& addr)
+{
+    LOCK(cs_mapLocalHost);
+    return vfReachable[addr.GetNetwork()];
+}
 
 bool GetMyExternalIP2(const CService& addrConnect, const char* pszGet, const char* pszKeyword, CNetAddr& ipRet)
 {