Added allowTcpFallbackRelay to local.conf, fixed logic in Binder's route enumeration

osdep/Binder.hpp

@@ -137,6 +137,7 @@ public:
 		std::map<InetAddress,std::string> localIfAddrs;
 		PhySocket *udps,*tcps;
 		Mutex::Lock _l(_lock);
+		bool interfacesEnumerated = true;
 
 #ifdef __WINDOWS__
 
@@ -167,6 +168,9 @@ public:
 				a = a->Next;
 			}
 		}
+		else {
+			interfacesEnumerated = false;
+		}
 
 #else // not __WINDOWS__
 
@@ -195,6 +199,9 @@ public:
 			}
 			fclose(procf);
 		}
+		else {
+			interfacesEnumerated = false;
+		}
 
 		// Get IPv6 addresses (and any device names we don't already know)
 		OSUtils::ztsnprintf(fn,sizeof(fn),"/proc/%lu/net/if_inet6",pid);
@@ -314,12 +321,15 @@ public:
 				}
 				freeifaddrs(ifatbl);
 			}
+			else {
+				interfacesEnumerated = false;
+			}
 		}
 
 #endif
 
 		// Default to binding to wildcard if we can't enumerate addresses
-		if (localIfAddrs.empty()) {
+		if (!interfacesEnumerated && localIfAddrs.empty()) {
 			for(int x=0;x<(int)portCount;++x) {
 				localIfAddrs.insert(std::pair<InetAddress,std::string>(InetAddress((uint32_t)0,ports[x]),std::string()));
 				localIfAddrs.insert(std::pair<InetAddress,std::string>(InetAddress((const void *)"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",16,ports[x]),std::string()));

service/OneService.cpp

@@ -398,6 +398,7 @@ public:
 	PhySocket *_localControlSocket4;
 	PhySocket *_localControlSocket6;
 	bool _updateAutoApply;
+	bool _allowTcpFallbackRelay;
 	unsigned int _primaryPort;
 	volatile unsigned int _udpPortPickerCounter;
 
@@ -1125,6 +1126,7 @@ public:
 					}
 					json &settings = res["config"]["settings"];
 					settings["primaryPort"] = OSUtils::jsonInt(settings["primaryPort"],(uint64_t)_primaryPort) & 0xffff;
+					settings["allowTcpFallbackRelay"] = OSUtils::jsonBool(settings["allowTcpFallbackRelay"],_allowTcpFallbackRelay);
 #ifdef ZT_USE_MINIUPNPC
 					settings["portMappingEnabled"] = OSUtils::jsonBool(settings["portMappingEnabled"],true);
 #else
@@ -1452,6 +1454,7 @@ public:
 		json &settings = lc["settings"];
 
 		_primaryPort = (unsigned int)OSUtils::jsonInt(settings["primaryPort"],(uint64_t)_primaryPort) & 0xffff;
+		_allowTcpFallbackRelay = OSUtils::jsonBool(settings["allowTcpFallbackRelay"],true);
 		_portMappingEnabled = OSUtils::jsonBool(settings["portMappingEnabled"],true);
 
 #ifndef ZT_SDK
@@ -2161,6 +2164,7 @@ public:
 	inline int nodeWirePacketSendFunction(const int64_t localSocket,const struct sockaddr_storage *addr,const void *data,unsigned int len,unsigned int ttl)
 	{
 #ifdef ZT_TCP_FALLBACK_RELAY
+		if(_allowTcpFallbackRelay) {
 			if (addr->ss_family == AF_INET) {
 				// TCP fallback tunnel support, currently IPv4 only
 				if ((len >= 16)&&(reinterpret_cast<const InetAddress *>(addr)->ipScope() == InetAddress::IP_SCOPE_GLOBAL)) {
@@ -2214,10 +2218,12 @@ public:
 					_lastSendToGlobalV4 = now;
 				}
 			}
+		}
+#endif // ZT_TCP_FALLBACK_RELAY
+
 		// Even when relaying we still send via UDP. This way if UDP starts
 		// working we can instantly "fail forward" to it and stop using TCP
 		// proxy fallback, which is slow.
-#endif // ZT_TCP_FALLBACK_RELAY
 
 		if ((localSocket != -1)&&(localSocket != 0)&&(_binder.isUdpSocketValid((PhySocket *)((uintptr_t)localSocket)))) {
 			if ((ttl)&&(addr->ss_family == AF_INET)) _phy.setIp4UdpTtl((PhySocket *)((uintptr_t)localSocket),ttl);
@@ -2286,7 +2292,6 @@ public:
 					return 0;
 			}
 		}
-
 		return 1;
 	}