Get ext. IP from UPnP, make sure addrMe IsRoutable() in version.

This fixes a potential bug where some NATs may replace the node's
interal IP with its external IP in version messages, causing
incorrect checksums when version messages begin being checksummed
on February 14, 2012.

diff --git a/src/net.cpp b/src/net.cpp
index 7642465..83e7f28 100644 (file)
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1103,6 +1103,26 @@ void ThreadMapPort2(void* parg)
     r = UPNP_GetValidIGD(devlist, &urls, &data, lanaddr, sizeof(lanaddr));
     if (r == 1)
     {
+        if (!addrLocalHost.IsRoutable())
+        {
+            char externalIPAddress[40];
+            r = UPNP_GetExternalIPAddress(urls.controlURL, data.first.servicetype, externalIPAddress);
+            if(r != UPNPCOMMAND_SUCCESS)
+                printf("UPnP: GetExternalIPAddress() returned %d\n", r);
+            else
+            {
+                if(externalIPAddress[0])
+                {
+                    printf("UPnP: ExternalIPAddress = %s\n", externalIPAddress);
+                    CAddress addrExternalFromUPnP(externalIPAddress, 0, false, nLocalServices);
+                    if (addrExternalFromUPnP.IsRoutable())
+                        addrLocalHost = addrExternalFromUPnP;
+                }
+                else
+                    printf("UPnP: GetExternalIPAddress failed.\n");
+            }
+        }
+
         string strDesc = "Bitcoin " + FormatFullVersion();
 #ifndef UPNPDISCOVER_SUCCESS
         /* miniupnpc 1.5 */

diff --git a/src/net.h b/src/net.h
index 52df06f..d8b9022 100644 (file)
--- a/src/net.h
+++ b/src/net.h
@@ -355,7 +355,7 @@ public:
         /// when NTP implemented, change to just nTime = GetAdjustedTime()
         int64 nTime = (fInbound ? GetAdjustedTime() : GetTime());
         CAddress addrYou = (fUseProxy ? CAddress("0.0.0.0") : addr);
-        CAddress addrMe = (fUseProxy ? CAddress("0.0.0.0") : addrLocalHost);
+        CAddress addrMe = (fUseProxy || !addrLocalHost.IsRoutable() ? CAddress("0.0.0.0") : addrLocalHost);
         RAND_bytes((unsigned char*)&nLocalHostNonce, sizeof(nLocalHostNonce));
         PushMessage("version", VERSION, nLocalServices, nTime, addrYou, addrMe,
                     nLocalHostNonce, std::string(pszSubVer), nBestHeight);