Version 5.1

It appears that in rare cases NAT reflection can work where real WAN traffic fails

mish/Product.wxs

@@ -14,6 +14,28 @@
     </Feature>
   </Product>
 
+  <!-- Enable the Windows Firewall service if it is disabled. Disabling the Windows Firewall service
+       will paradoxically block *all* incoming network traffic and prevent GameStream, MIST, MISS,
+       and other local servers from working at all. The proper way to disable Windows Firewall is via
+       the Windows Firewall control panel applet. -->
+  <Fragment>
+    <Property Id="MPSSVC_START">
+      <RegistrySearch Id="MpsSvcStart"
+                      Root="HKLM"
+                      Key="System\CurrentControlSet\Services\MpsSvc"
+                      Name="Start"
+                      Type="raw" />
+    </Property>
+
+    <SetProperty Id="EnableMpsSvc" Value='"[SystemFolder]sc.exe" config MpsSvc start= auto' Sequence="execute" Before="InstallInitialize"/>
+    <CustomAction Id="EnableMpsSvc" BinaryKey="WixCA" DllEntry="WixQuietExec"
+                  Execute="deferred" Return="ignore" Impersonate="no"/>
+
+    <SetProperty Id="StartMpsSvc" Value='"[SystemFolder]net.exe" start MpsSvc' Sequence="execute" Before="InstallInitialize"/>
+    <CustomAction Id="StartMpsSvc" BinaryKey="WixCA" DllEntry="WixQuietExec"
+                  Execute="deferred" Return="ignore" Impersonate="no"/>
+  </Fragment>
+  
   <Fragment>
     <Directory Id="TARGETDIR" Name="SourceDir">
       <Directory Id="ProgramFilesFolder">
@@ -69,5 +91,14 @@
         <RegistryValue Root="HKCU" Key="Software\Moonlight Internet Streaming Tester" Name="Installed" Type="integer" Value="1" KeyPath="yes" />
       </Component>
     </ComponentGroup>
+
+    <InstallExecuteSequence>
+      <Custom Action="EnableMpsSvc" Before="StartMpsSvc">
+        <![CDATA[MPSSVC_START <> "#2"]]>
+      </Custom>
+      <Custom Action="StartMpsSvc" Before="StopServices">
+        <![CDATA[MPSSVC_START <> "#2"]]>
+      </Custom>
+    </InstallExecuteSequence>
   </Fragment>
 </Wix>

mist/mist.cpp

@@ -5,15 +5,16 @@
 #include <assert.h>
 #include <shellapi.h>
 #include <objbase.h>
-#include <WinInet.h>
+#include <WinHttp.h>
 #include <wtsapi32.h>
 #include <powerbase.h>
+#include <VersionHelpers.h>
 
 #pragma comment(lib, "miniupnpc.lib")
 #pragma comment(lib, "libnatpmp.lib")
 #pragma comment(lib, "ws2_32.lib")
 #pragma comment(lib, "iphlpapi.lib")
-#pragma comment(lib, "wininet.lib")
+#pragma comment(lib, "winhttp.lib")
 #pragma comment(lib, "wtsapi32.lib")
 #pragma comment(lib, "powrprof.lib")
 
@@ -25,6 +26,8 @@
 #define NATPMP_STATICLIB
 #include <natpmp.h>
 
+#define LOOPBACK_SERVER_PORT_OFFSET -10000
+
 static struct port_entry {
     int proto;
     int port;
@@ -456,7 +459,7 @@ PortTestStatus TestPort(PSOCKADDR_STORAGE addr, int proto, int port, bool withSe
         sizeof(SOCKADDR_IN) : sizeof(SOCKADDR_IN6);
 
     RtlCopyMemory(&sin6, addr, addrLen);
-    sin6.sin6_port = htons(port);
+    sin6.sin6_port = htons(port + (isLoopbackRelay ? LOOPBACK_SERVER_PORT_OFFSET : 0));
 
     if (proto == IPPROTO_TCP) {
         err = connect(clientSock, (struct sockaddr*)&sin6, addrLen);
@@ -546,64 +549,100 @@ PortTestStatus TestPort(PSOCKADDR_STORAGE addr, int proto, int port, bool withSe
     }
 }
 
-PortTestStatus TestHttpPort(PSOCKADDR_STORAGE addr, int port)
+PortTestStatus TestHttpPort(PSOCKADDR_STORAGE addr, int port, bool isLoopbackRelay)
 {
-    HINTERNET hInternet;
+    HINTERNET hSession = nullptr;
-    HINTERNET hRequest;
+    HINTERNET hConnection = nullptr;
-    char url[1024];
+    HINTERNET hRequest = nullptr;
+    PortTestStatus result;
 
-    hInternet = InternetOpenA("MIST", 0, nullptr, nullptr, 0);
+    hSession = WinHttpOpen(L"MIST", WINHTTP_ACCESS_TYPE_NO_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
-    if (hInternet == nullptr) {
+    if (hSession == nullptr) {
-        fprintf(LOG_OUT, "InternetOpen() failed: %d\n", GetLastError());
+        fprintf(LOG_OUT, "WinHttpOpen() failed: %d\n", GetLastError());
-        return PortTestError;
+        result = PortTestError;
+        goto Exit;
     }
 
-    char addrStr[INET6_ADDRSTRLEN + 2];
+    // WinHTTP's default timeouts are very long. Set them to something more reasonable.
+    if (!WinHttpSetTimeouts(hSession, 0, 3000, 5000, 5000)) {
+        fprintf(LOG_OUT, "WinHttpSetTimeouts() failed: %d\n", GetLastError());
+    }
+
+    // Windows 8.1 enabled TLSv1.2 for WinHTTP by default (8.0 enables it for Schannel but not WinHTTP)
+    // https://docs.microsoft.com/en-us/security/engineering/solving-tls1-problem
+    if (!IsWindows8Point1OrGreater()) {
+        DWORD protocols = WINHTTP_FLAG_SECURE_PROTOCOL_TLS1 |
+                          WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_1 |
+                          WINHTTP_FLAG_SECURE_PROTOCOL_TLS1_2;
+
+        if (!WinHttpSetOption(hSession, WINHTTP_OPTION_SECURE_PROTOCOLS, &protocols, sizeof(protocols))) {
+            fprintf(LOG_OUT, "WinHttpSetOption(WINHTTP_OPTION_SECURE_PROTOCOLS) failed: %d\n", GetLastError());
+        }
+    }
+
+    WCHAR urlEscapedAddr[INET6_ADDRSTRLEN + 2];
     if (addr->ss_family == AF_INET) {
-        inet_ntop(AF_INET, &((struct sockaddr_in*)addr)->sin_addr, addrStr, sizeof(addrStr));
+        InetNtopW(AF_INET, &((struct sockaddr_in*)addr)->sin_addr, urlEscapedAddr, ARRAYSIZE(urlEscapedAddr));
     }
     else {
         // The address string must be escaped for usage in URLs
-        addrStr[0] = '[';
+        urlEscapedAddr[0] = L'[';
-        inet_ntop(AF_INET6, &((struct sockaddr_in6*)addr)->sin6_addr, &addrStr[1], INET6_ADDRSTRLEN);
+        InetNtopW(AF_INET6, &((struct sockaddr_in6*)addr)->sin6_addr, &urlEscapedAddr[1], INET6_ADDRSTRLEN);
-        strcat_s(addrStr, "]");
+        wcscat_s(urlEscapedAddr, L"]");
     }
 
-    sprintf(url, "%s://%s:%d/",
+    hConnection = WinHttpConnect(hSession, urlEscapedAddr, port + (isLoopbackRelay ? LOOPBACK_SERVER_PORT_OFFSET : 0), NULL);
-        port == 47989 ? "http" : "https",
+    if (hConnection == nullptr) {
-        addrStr,
+        fprintf(LOG_OUT, "WinHttpConnect() failed: %d\n", GetLastError());
-        port);
+        result = PortTestError;
+        goto Exit;
+    }
 
-    hRequest = InternetOpenUrlA(hInternet, url, nullptr, 0,
+    hRequest = WinHttpOpenRequest(hConnection, L"GET", L"/", NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES,
-        INTERNET_FLAG_IGNORE_CERT_DATE_INVALID | INTERNET_FLAG_NO_UI | INTERNET_FLAG_NO_AUTH | INTERNET_FLAG_NO_COOKIES | INTERNET_FLAG_RELOAD,
+                                  port == 47984 ? WINHTTP_FLAG_SECURE : 0);
-        NULL);
+    if (hConnection == nullptr) {
-    if (hRequest == nullptr) {
+        fprintf(LOG_OUT, "WinHttpOpenRequest() failed: %d\n", GetLastError());
-        if (GetLastError() == ERROR_INTERNET_CLIENT_AUTH_CERT_NEEDED) {
+        result = PortTestError;
+        goto Exit;
+    }
+
+    if (!WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0) || !WinHttpReceiveResponse(hRequest, NULL)) {
+        if (GetLastError() == ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED) {
             // This is expected for our HTTPS connection
             fprintf(LOG_OUT, "Success\n");
+            result = PortTestOk;
         }
         else {
             // CANNOT_CONNECT is the "expected" error
-            if (GetLastError() == ERROR_INTERNET_CANNOT_CONNECT) {
+            if (GetLastError() == ERROR_WINHTTP_CANNOT_CONNECT) {
                 fprintf(LOG_OUT, "Failed\n");
             }
             else {
                 fprintf(LOG_OUT, "Failed: %d\n", GetLastError());
             }
 
-            InternetCloseHandle(hInternet);
+            result = PortTestError;
-            return PortTestError;
         }
+
+        goto Exit;
     }
     else {
         fprintf(LOG_OUT, "Success\n");
-        InternetCloseHandle(hRequest);
+        result = PortTestOk;
     }
 
+Exit:
+    if (hRequest != nullptr) {
+        WinHttpCloseHandle(hRequest);
+    }
+    if (hConnection != nullptr) {
+        WinHttpCloseHandle(hConnection);
+    }
+    if (hSession != nullptr) {
+        WinHttpCloseHandle(hSession);
+    }
 
-    InternetCloseHandle(hInternet);
+    return result;
-
-    return PortTestOk;
 }
 
 bool TestAllPorts(PSOCKADDR_STORAGE addr, char* portMsg, int portMsgLen, bool isLoopbackRelay, bool consolePrint, bool* allPortsFailed = nullptr)
@@ -615,9 +654,7 @@ bool TestAllPorts(PSOCKADDR_STORAGE addr, char* portMsg, int portMsgLen, bool is
     }
 
     for (int i = 0; i < ARRAYSIZE(k_Ports); i++) {
-        fprintf(LOG_OUT, "Testing %s %d...",
+        PortTestStatus status;
-            k_Ports[i].proto == IPPROTO_TCP ? "TCP" : "UDP",
-            k_Ports[i].port);
 
         if (consolePrint) {
             fprintf(CONSOLE_OUT, "\tTesting %s %d...\n",
@@ -625,15 +662,18 @@ bool TestAllPorts(PSOCKADDR_STORAGE addr, char* portMsg, int portMsgLen, bool is
                 k_Ports[i].port);
         }
 
-        PortTestStatus status = TestPort(addr, k_Ports[i].proto, k_Ports[i].port, k_Ports[i].withServer, isLoopbackRelay);
+        if (!k_Ports[i].withServer) {
-
-        if (status != PortTestError && !k_Ports[i].withServer) {
             // Test using a real HTTP client if the port wasn't totally dead.
             // This is required to confirm functionality with the loopback relay.
-            // TestHttpPort() can take significantly longer to timeout than TestPort(),
+            assert(k_Ports[i].proto == IPPROTO_TCP);
-            // so we only do this test if we believe we're likely to get a response.
             fprintf(LOG_OUT, "Testing TCP %d with HTTP traffic...", k_Ports[i].port);
-            status = TestHttpPort(addr, k_Ports[i].port);
+            status = TestHttpPort(addr, k_Ports[i].port, isLoopbackRelay);
+        }
+        else {
+            fprintf(LOG_OUT, "Testing %s %d...",
+                k_Ports[i].proto == IPPROTO_TCP ? "TCP" : "UDP",
+                k_Ports[i].port);
+            status = TestPort(addr, k_Ports[i].proto, k_Ports[i].port, k_Ports[i].withServer, isLoopbackRelay);
         }
 
         if (status != PortTestOk) {
@@ -660,6 +700,81 @@ bool TestAllPorts(PSOCKADDR_STORAGE addr, char* portMsg, int portMsgLen, bool is
     return ret;
 }
 
+bool IsTestServerReachable(struct addrinfo* addrinfo, unsigned short port)
+{
+    SOCKET s;
+    FD_SET writeFds, exceptFds;
+    int err;
+    struct timeval tv = {};
+    SOCKADDR_STORAGE addr;
+    char testServerStr[INET6_ADDRSTRLEN];
+
+    memcpy(&addr, addrinfo->ai_addr, addrinfo->ai_addrlen);
+    ((PSOCKADDR_IN6)&addr)->sin6_port = htons(port);
+
+    if (addr.ss_family == AF_INET) {
+        inet_ntop(AF_INET, &((struct sockaddr_in*)&addr)->sin_addr, testServerStr, sizeof(testServerStr));
+    }
+    else {
+        inet_ntop(AF_INET6, &((struct sockaddr_in6*)&addr)->sin6_addr, testServerStr, sizeof(testServerStr));
+    }
+
+    fprintf(LOG_OUT, "Testing reachability of relay server %s...", testServerStr);
+
+    s = socket(addrinfo->ai_family, SOCK_STREAM, IPPROTO_TCP);
+    if (s == INVALID_SOCKET) {
+        fprintf(LOG_OUT, "socket() failed: %d\n", WSAGetLastError());
+        return false;
+    }
+
+    ULONG nbIo = 1;
+    err = ioctlsocket(s, FIONBIO, &nbIo);
+    if (err == SOCKET_ERROR) {
+        fprintf(LOG_OUT, "ioctlsocket() failed: %d\n", WSAGetLastError());
+        closesocket(s);
+        return false;
+    }
+
+    err = connect(s, (PSOCKADDR)&addr, addrinfo->ai_addrlen);
+    if (err == SOCKET_ERROR && WSAGetLastError() != WSAEWOULDBLOCK) {
+        fprintf(LOG_OUT, "Unreachable (%d)\n", WSAGetLastError());
+        closesocket(s);
+        return false;
+    }
+
+    FD_ZERO(&writeFds);
+    FD_ZERO(&exceptFds);
+
+    FD_SET(s, &writeFds);
+    FD_SET(s, &exceptFds);
+
+    tv.tv_sec = 3;
+    err = select(0, nullptr, &writeFds, &exceptFds, &tv);
+    if (err == SOCKET_ERROR) {
+        fprintf(LOG_OUT, "select() failed: %d\n", WSAGetLastError());
+        closesocket(s);
+        return false;
+    }
+    else if (err == 0) {
+        fprintf(LOG_OUT, "Unreachable (timeout)\n");
+        closesocket(s);
+        return false;
+    }
+    else {
+        int optlen = sizeof(err);
+        getsockopt(s, SOL_SOCKET, SO_ERROR, (char*)&err, &optlen);
+        closesocket(s);
+
+        if (err != 0 || FD_ISSET(s, &exceptFds)) {
+            fprintf(LOG_OUT, "Unreachable (%d)\n", err);
+            return false;
+        }
+
+        fprintf(LOG_OUT, "Reachable\n");
+        return true;
+    }
+}
+
 bool FindLocalInterfaceIPAddress(int family, PSOCKADDR_STORAGE addr)
 {
     SOCKET s;
@@ -673,9 +788,16 @@ bool FindLocalInterfaceIPAddress(int family, PSOCKADDR_STORAGE addr)
     hint.ai_socktype = SOCK_STREAM;
     hint.ai_protocol = IPPROTO_TCP;
     hint.ai_flags = AI_ADDRCONFIG;
-    err = getaddrinfo("moonlight-stream.org", "https", &hint, &result);
+    err = getaddrinfo("moonlight-stream.org", "443", &hint, &result);
     if (err != 0 || result == NULL) {
-        fprintf(LOG_OUT, "getaddrinfo() failed: %d\n", err);
+        // AI_ADDRCONFIG will mask unusable addresses, so we may get nothing
+        // We get WSANO_DATA or WSAHOST_NOT_FOUND depending on whether it's V4 or V6 :(
+        if (err == WSANO_DATA || err == WSAHOST_NOT_FOUND) {
+            fprintf(LOG_OUT, "NONE\n");
+        }
+        else {
+            fprintf(LOG_OUT, "getaddrinfo() failed: %d\n", err);
+        }
         return false;
     }
 
@@ -972,7 +1094,7 @@ bool CheckWANAccess(PSOCKADDR_IN wanAddr, PSOCKADDR_IN reportedWanAddr, bool* fo
         closenatpmp(&natpmp);
 
         if (natPmpErr == 0) {
-            char addrStr[64];
+            char addrStr[INET_ADDRSTRLEN];
             reportedWanAddr->sin_addr = response.pnu.publicaddress.addr;
             inet_ntop(AF_INET, &response.pnu.publicaddress.addr, addrStr, sizeof(addrStr));
             fprintf(LOG_OUT, "%s\n", addrStr);
@@ -999,7 +1121,7 @@ bool CheckWANAccess(PSOCKADDR_IN wanAddr, PSOCKADDR_IN reportedWanAddr, bool* fo
         return false;
     }
     else {
-        char addrStr[64];
+        char addrStr[INET_ADDRSTRLEN];
         inet_ntop(AF_INET, &wanAddr->sin_addr, addrStr, sizeof(addrStr));
         fprintf(LOG_OUT, "%s\n", addrStr);
 
@@ -1013,16 +1135,12 @@ bool CheckWANAccess(PSOCKADDR_IN wanAddr, PSOCKADDR_IN reportedWanAddr, bool* fo
     return true;
 }
 
-bool IsPossibleCGN(PSOCKADDR_IN wanAddr)
+bool IsCGN(PSOCKADDR_IN wanAddr)
 {
     DWORD addr = htonl(wanAddr->sin_addr.S_un.S_addr);
 
-    // 10.0.0.0/8 - ISPs used to use this
-    if ((addr & 0xFF000000) == 0x0A000000) {
-        return true;
-    }
     // 100.64.0.0/10 - RFC6598 official CGN address
-    else if ((addr & 0xFFC00000) == 0x64400000) {
+    if ((addr & 0xFFC00000) == 0x64400000) {
         return true;
     }
 
@@ -1202,9 +1320,24 @@ int main(int argc, char* argv[])
         }
     }
 
-    if (!FindLocalInterfaceIPAddress(AF_INET, &ss) && !FindLocalInterfaceIPAddress(AF_INET6, &ss)) {
+    bool hasV4Connectivity, hasV6Connectivity;
-        DisplayMessage("Unable to perform GameStream connectivity check. Please check your Internet connection and try again.");
+    {
-        return -1;
+        SOCKADDR_STORAGE v4, v6;
+
+        hasV4Connectivity = FindLocalInterfaceIPAddress(AF_INET, &v4);
+        hasV6Connectivity = FindLocalInterfaceIPAddress(AF_INET6, &v6);
+
+        // Prefer v4 connectivity because that's what GFE uses natively
+        if (hasV4Connectivity) {
+            ss = v4;
+        }
+        else if (hasV6Connectivity) {
+            ss = v6;
+        }
+        else {
+            DisplayMessage("Unable to perform GameStream connectivity check. Please check your Internet connection and try again.");
+            return -1;
+        }
     }
 
     fprintf(CONSOLE_OUT, "Testing GameStream connectivity on your local network...\n");
@@ -1220,7 +1353,7 @@ int main(int argc, char* argv[])
 
     bool igdDisconnected;
     SOCKADDR_IN locallyReportedWanAddr;
-    char wanAddrStr[INET_ADDRSTRLEN];
+    char wanAddrStr[INET6_ADDRSTRLEN];
 
     if (ss.ss_family == AF_INET) {
         bool rulesFound;
@@ -1231,8 +1364,6 @@ int main(int argc, char* argv[])
             return -1;
         }
 
-        fprintf(CONSOLE_OUT, "Testing GameStream connectivity over the Internet...\n");
-
         // Detect a double NAT by detecting STUN and and UPnP mismatches
         if (sin.sin_addr.S_un.S_addr != locallyReportedWanAddr.sin_addr.S_un.S_addr) {
             fprintf(LOG_OUT, "Testing GameStream ports via UPnP/NAT-PMP reported WAN address\n");
@@ -1250,101 +1381,122 @@ int main(int argc, char* argv[])
         // Go directly to the relay check if we have only IPv6 connectivity
         igdDisconnected = false;
         locallyReportedWanAddr = {};
-        goto RelayCheck;
     }
 
-    // Try to connect via WAN IPv4 address
+    struct addrinfo hint = {};
-    fprintf(LOG_OUT, "Testing GameStream ports via STUN-reported WAN address\n");
+    struct addrinfo* result;
-    if (!TestAllPorts(&ss, portMsgBuf, sizeof(portMsgBuf), false, true)) {
-    RelayCheck:
-        struct addrinfo hint = {};
-        struct addrinfo* result;
 
-        // We can get here if the router doesn't support NAT reflection.
+    hint.ai_family = AF_UNSPEC;
-        // We'll need to call out to our loopback server to get a second opinion.
+    hint.ai_flags = AI_ADDRCONFIG;
+    err = getaddrinfo("loopback-v2.moonlight-stream.org", NULL, &hint, &result);
+    if (err != 0 || result == NULL) {
+        fprintf(LOG_OUT, "getaddrinfo() failed: %d\n", err);
+    }
+    else {
+        bool testServerWasReachable = false;
+        bool allPortsFailedOnV4 = true;
 
-        hint.ai_family = AF_UNSPEC;
+        // First try the relay server over IPv4. If this passes, it's considered a full success
-        hint.ai_flags = AI_ADDRCONFIG;
+        fprintf(LOG_OUT, "Testing GameStream ports via IPv4 loopback server\n");
-        err = getaddrinfo("loopback.moonlight-stream.org", NULL, &hint, &result);
+        for (struct addrinfo* current = result; current != NULL; current = current->ai_next) {
-        if (err != 0 || result == NULL) {
+            if (current->ai_family == AF_INET) {
-            fprintf(LOG_OUT, "getaddrinfo() failed: %d\n", err);
+                fprintf(CONSOLE_OUT, "Testing GameStream connectivity over the Internet using a relay server...\n");
+
+                if (!IsTestServerReachable(current, 443)) {
+                    fprintf(CONSOLE_OUT, "Skipping unreachable relay server...\n");
+                    continue;
+                }
+
+                testServerWasReachable = true;
+
+                if (TestAllPorts((PSOCKADDR_STORAGE)current->ai_addr, portMsgBuf, sizeof(portMsgBuf), true, true, &allPortsFailedOnV4)) {
+                    freeaddrinfo(result);
+                    snprintf(msgBuf, sizeof(msgBuf), "This PC is ready to host over the Internet!\n\n"
+                        "For the easiest setup, you should pair Moonlight to your gaming PC from your home network before trying to stream over the Internet.\n\n"
+                        "If you can't, you can type the following address into Moonlight's Add PC dialog: %s", wanAddrStr);
+                    DisplayMessage(msgBuf, nullptr, MpInfo);
+                    return 0;
+                }
+                else {
+                    // Tested against a working server and it failed
+                    break;
+                }
+            }
         }
-        else {
-            bool allPortsFailedOnV4 = true;
 
-            // First try the relay server over IPv4. If this passes, it's considered a full success
+        // If that fails, try the relay server over IPv6. If this passes, it will be a partial success
-            fprintf(LOG_OUT, "Testing GameStream ports via IPv4 loopback server\n");
+        fprintf(LOG_OUT, "Testing GameStream ports via IPv6 loopback server\n");
-            for (struct addrinfo* current = result; current != NULL; current = current->ai_next) {
+        for (struct addrinfo* current = result; current != NULL; current = current->ai_next) {
-                if (current->ai_family == AF_INET) {
+            if (current->ai_family == AF_INET6) {
-                    fprintf(CONSOLE_OUT, "Testing GameStream connectivity over the Internet using a relay server...\n");
+                fprintf(CONSOLE_OUT, "Testing GameStream connectivity over the Internet using an IPv6 relay server...\n");
-                    if (TestAllPorts((PSOCKADDR_STORAGE)current->ai_addr, portMsgBuf, sizeof(portMsgBuf), true, true, &allPortsFailedOnV4)) {
+
+                if (!IsTestServerReachable(current, 443)) {
+                    fprintf(CONSOLE_OUT, "Skipping unreachable IPv6 relay server...\n");
+                    continue;
+                }
+
+                testServerWasReachable = true;
+
+                // Pass the portMsgBuf only if we've detected an IPv6-only setup. Otherwise, we want to preserve
+                // the failing ports from the IPv4 to display in the error dialog.
+                if (TestAllPorts((PSOCKADDR_STORAGE)current->ai_addr,
+                                    ss.ss_family == AF_INET6 ? portMsgBuf : NULL,
+                                    ss.ss_family == AF_INET6 ? sizeof(portMsgBuf) : 0, true, true)) {
+                    // We will terminate the test at the IPv6 limited connectivity warning in the following cases:
+                    // 1) Double-NAT/CGN - indicates the connection is fundamentally limited to IPv6 for end-to-end connectivity
+                    // 2) IPv6-only - indicates the connection is fundamentally limited to IPv6 for all connectivity
+                    // 3) All ports failed the test with our IPv4 relay - This is one final heuristic to weed out IPv4 misconfigurations. If we have some ports open,
+                    //                                                    it clearly indicates IPv4 support is possible, just currently misconfigured.
+                    //
+                    // Our last (implicit) heuristic is that we actually managed to establish an IPv6 connection. This means that there was either
+                    // no IPv6 firewall (hopefully not) or that we were able to talk to a PCP/IGDv6 gateway to allow us through. Hopefully if we have
+                    // a gateway that is unresponsive to UPnP/NAT-PMP, we wouldn't even be able to establish this connection so we would inherently fall
+                    // to the checks below for IPv4 issues.
+                    if (IsDoubleNAT(&locallyReportedWanAddr) || igdDisconnected || IsCGN(&locallyReportedWanAddr) || ss.ss_family == AF_INET6 || allPortsFailedOnV4) {
+                        snprintf(msgBuf, sizeof(msgBuf), "This PC has limited connectivity for Internet hosting. It will work only for clients on certain networks.\n\n"
+                            "If you want to try streaming with this configuration, you must pair Moonlight to your gaming PC from your home network before trying to stream over the Internet.\n\n"
+                            "To get full connectivity, please contact your ISP and ask for a \"public IPv4 address\" which they may offer for free upon request. For more information and workarounds, click the Help button.");
+                        DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#limited-connectivity-for-hosting-error", MpWarn);
                         freeaddrinfo(result);
-                        goto AllTestsPassed;
+                        return 0;
                     }
                 }
-            }
+                else {
-
+                    // Tested against a working server and it failed
-            // If that fails, try the relay server over IPv6. If this passes, it will be a partial success
+                    break;
-            fprintf(LOG_OUT, "Testing GameStream ports via IPv6 loopback server\n");
-            for (struct addrinfo* current = result; current != NULL; current = current->ai_next) {
-                if (current->ai_family == AF_INET6) {
-                    fprintf(CONSOLE_OUT, "Testing GameStream connectivity over the Internet using an IPv6 relay server...\n");
-                    // Pass the portMsgBuf only if we've detected an IPv6-only setup. Otherwise, we want to preserve
-                    // the failing ports from the IPv4 to display in the error dialog.
-                    if (TestAllPorts((PSOCKADDR_STORAGE)current->ai_addr,
-                                     ss.ss_family == AF_INET6 ? portMsgBuf : NULL,
-                                     ss.ss_family == AF_INET6 ? sizeof(portMsgBuf) : 0, true, true)) {
-                        // We will terminate the test at the IPv6 limited connectivity warning in the following cases:
-                        // 1) Double-NAT/CGN - indicates the connection is fundamentally limited to IPv6 for end-to-end connectivity
-                        // 2) IPv6-only - indicates the connection is fundamentally limited to IPv6 for all connectivity
-                        // 3) All ports failed the test with our IPv4 relay - This is one final heuristic to weed out IPv4 misconfigurations. If we have some ports open,
-                        //                                                    it clearly indicates IPv4 support is possible, just currently misconfigured.
-                        //
-                        // Our last (implicit) heuristic is that we actually managed to establish an IPv6 connection. This means that there was either
-                        // no IPv6 firewall (hopefully not) or that we were able to talk to a PCP/IGDv6 gateway to allow us through. Hopefully if we have
-                        // a gateway that is unresponsive to UPnP/NAT-PMP, we wouldn't even be able to establish this connection so we would inherently fall
-                        // to the checks below for IPv4 issues.
-                        if (IsDoubleNAT(&locallyReportedWanAddr) || igdDisconnected || IsPossibleCGN(&locallyReportedWanAddr) || ss.ss_family == AF_INET6 || allPortsFailedOnV4) {
-                            snprintf(msgBuf, sizeof(msgBuf), "This PC has limited connectivity for Internet hosting. It will work only for clients on certain networks.\n\n"
-                                "If you want to try streaming with this configuration, you must pair Moonlight to your gaming PC from your home network before trying to stream over the Internet.\n\n"
-                                "To get full connectivity, please contact your ISP and ask for a \"public IP address\" which they may offer for free upon request. For more information and workarounds, click the Help button.");
-                            DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#limited-connectivity-for-hosting-error", MpWarn);
-                            freeaddrinfo(result);
-                            return 0;
-                        }
-                    }
                 }
             }
-
-            freeaddrinfo(result);
         }
 
-        // Many UPnP devices report IGD disconnected when double-NATed. If it was really offline,
+        freeaddrinfo(result);
-        // we probably would not have even gotten past STUN.
-        if (IsDoubleNAT(&locallyReportedWanAddr) || igdDisconnected) {
-            snprintf(msgBuf, sizeof(msgBuf), "Your router appears be connected to the Internet through another router. Click the Help button for guidance on fixing this issue.");
-            DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#connected-through-another-router-error");
-        }
-        else if (IsPossibleCGN(&locallyReportedWanAddr)) {
-            snprintf(msgBuf, sizeof(msgBuf), "Your ISP is running a Carrier-Grade NAT that is preventing you from hosting services like Moonlight on the Internet.\n\n"
-                "Ask your ISP for a \"public IP address\" which they may offer for free upon request. For more information and workarounds, click the Help button.");
-            DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#carrier-grade-nat-error");
-        }
-        else {
-            snprintf(msgBuf, sizeof(msgBuf), "Internet GameStream connectivity check failed.\n\n"
-                "First, try restarting your router. If that fails, check that UPnP is enabled in your router settings. For more information and workarounds, click the Help button.\n\n"
-                "The following ports were not forwarded properly:\n%s", portMsgBuf);
-            DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#internet-gamestream-connectivity-check-error");
-        }
 
-        return -1;
+        if (!testServerWasReachable) {
+            snprintf(msgBuf, sizeof(msgBuf), "None of Moonlight's connection testing servers were reachable from your PC. Check your Internet connection and try again later.");
+            DisplayMessage(msgBuf);
+            return 0;
+        }
+    }
+    // Many UPnP devices report IGD disconnected when double-NATed. If it was really offline,
+    // we probably would not have even gotten past STUN.
+    //
+    // We try to tell double-NAT from CGN by checking if IPv6 connectivity is available. If it
+    // is, we assume we're in a DS-Lite or similar configuration. If not, we'll assume it's a
+    // real double-NAT setup.
+    if (IsCGN(&locallyReportedWanAddr) || ((IsDoubleNAT(&locallyReportedWanAddr) || igdDisconnected) && hasV6Connectivity)) {
+        snprintf(msgBuf, sizeof(msgBuf), "Your ISP is running a Carrier-Grade NAT that is preventing you from hosting services like Moonlight on the Internet.\n\n"
+            "Ask your ISP for a \"public IPv4 address\" which they may offer for free upon request. For more information and workarounds, click the Help button.");
+        DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#carrier-grade-nat-error");
+    }
+    else if ((IsDoubleNAT(&locallyReportedWanAddr) || igdDisconnected) /* && !hasV6Connectivity */) {
+        snprintf(msgBuf, sizeof(msgBuf), "Your router appears be connected to the Internet through another router. Click the Help button for guidance on fixing this issue.");
+        DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#connected-through-another-router-error");
+    }
+    else {
+        snprintf(msgBuf, sizeof(msgBuf), "Internet GameStream connectivity check failed.\n\n"
+            "First, try restarting your router. If that fails, check that UPnP is enabled in your router settings. For more information and workarounds, click the Help button.\n\n"
+            "The following ports were not forwarded properly:\n%s", portMsgBuf);
+        DisplayMessage(msgBuf, "https://github.com/moonlight-stream/moonlight-docs/wiki/Internet-Streaming-Errors#internet-gamestream-connectivity-check-error");
     }
 
-AllTestsPassed:
+    return -1;
-    snprintf(msgBuf, sizeof(msgBuf), "This PC is ready to host over the Internet!\n\n"
-        "For the easiest setup, you should pair Moonlight to your gaming PC from your home network before trying to stream over the Internet.\n\n"
-        "If you can't, you can type the following address into Moonlight's Add PC dialog: %s", wanAddrStr);
-    DisplayMessage(msgBuf, nullptr, MpInfo);
-
-    return 0;
 }

mist/mist.exe.manifest

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv3="urn:schemas-microsoft-com:asm.v3" manifestVersion="1.0">
+    <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+        <application>
+            <!-- Windows 10 -->
+            <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}"/>
+            <!-- Windows 8.1 -->
+            <supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}"/>
+            <!-- Windows 8 -->
+            <supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}"/>
+            <!-- Windows 7 -->
+            <supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>
+            <!-- Windows Vista -->
+            <supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}"/>
+        </application> 
+    </compatibility>
+</assembly>

mist/mist.vcxproj

@@ -100,6 +100,9 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <AdditionalLibraryDirectories>..\libs\x86\Debug;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
     </Link>
+    <Manifest>
+      <AdditionalManifestFiles>mist.exe.manifest</AdditionalManifestFiles>
+    </Manifest>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <ClCompile>
@@ -115,6 +118,9 @@
       <SubSystem>Console</SubSystem>
       <GenerateDebugInformation>true</GenerateDebugInformation>
     </Link>
+    <Manifest>
+      <AdditionalManifestFiles>mist.exe.manifest</AdditionalManifestFiles>
+    </Manifest>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
@@ -138,6 +144,9 @@
       <GenerateDebugInformation>true</GenerateDebugInformation>
       <AdditionalLibraryDirectories>..\libs\x86\Release;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
     </Link>
+    <Manifest>
+      <AdditionalManifestFiles>mist.exe.manifest</AdditionalManifestFiles>
+    </Manifest>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
     <ClCompile>
@@ -157,6 +166,9 @@
       <OptimizeReferences>true</OptimizeReferences>
       <GenerateDebugInformation>true</GenerateDebugInformation>
     </Link>
+    <Manifest>
+      <AdditionalManifestFiles>mist.exe.manifest</AdditionalManifestFiles>
+    </Manifest>
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="mist.cpp" />
@@ -169,6 +181,9 @@
     <ClInclude Include="..\version.h" />
     <ClInclude Include="mist.h" />
   </ItemGroup>
+  <ItemGroup>
+    <Manifest Include="mist.exe.manifest" />
+  </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>

mist/mist.vcxproj.filters

@@ -35,4 +35,9 @@
       <Filter>Source Files</Filter>
     </ResourceCompile>
   </ItemGroup>
+  <ItemGroup>
+    <Manifest Include="mist.exe.manifest">
+      <Filter>Resource Files</Filter>
+    </Manifest>
+  </ItemGroup>
 </Project>

version.h

@@ -1,7 +1,7 @@
 #pragma once
 
-#define VER_VERSION                 4,4,0,0
+#define VER_VERSION                 5,1,0,0
-#define VER_VERSION_STR             "4.4.0.0"
+#define VER_VERSION_STR             "5.1.0.0"
 
 #define VER_COMPANYNAME_STR         "Moonlight Game Streaming Project"
 #define VER_PRODUCTNAME_STR         "Moonlight Internet Hosting Tool"