Add traceroute code for experimental double NAT handling

miss/miss.vcxproj

@@ -162,6 +162,7 @@
   </ItemDefinitionGroup>
   <ItemGroup>
     <ClCompile Include="miss.cpp" />
+    <ClCompile Include="tracer.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="miss.rc" />

miss/miss.vcxproj.filters

@@ -18,6 +18,9 @@
     <ClCompile Include="miss.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="tracer.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="miss.rc">

miss/tracer.cpp

@@ -0,0 +1,75 @@
+#define WIN32_LEAN_AND_MEAN
+#define _WINSOCK_DEPRECATED_NO_WARNINGS
+#include <Windows.h>
+
+#include <WinSock2.h>
+#include <WS2tcpip.h>
+#include <iphlpapi.h>
+#include <icmpapi.h>
+
+#include <stdio.h>
+
+bool getHopsIP4(IN_ADDR* hopAddress, int* hopAddressCount)
+{
+    HANDLE icmpFile;
+    struct hostent* host;
+    const char* requestBuffer = "Test";
+    union {
+        ICMP_ECHO_REPLY replies[ANYSIZE_ARRAY];
+        char replyBuffer[128];
+    };
+
+    host = gethostbyname("google.com");
+    if (host == nullptr) {
+        printf("gethostbyname() failed: %d\n", WSAGetLastError());
+        return false;
+    }
+
+    icmpFile = IcmpCreateFile();
+    if (icmpFile == INVALID_HANDLE_VALUE) {
+        printf("IcmpCreateFile() failed: %d\n", GetLastError());
+        return false;
+    }
+
+    int ttl = 1;
+    for (; ttl < *hopAddressCount; ttl++)
+    {
+        IP_OPTION_INFORMATION ipOptions;
+
+        ipOptions.Ttl = ttl;
+        ipOptions.Tos = 0;
+        ipOptions.Flags = 0;
+        ipOptions.OptionsSize = 0;
+
+        DWORD replyCount = IcmpSendEcho(icmpFile,
+            *(IPAddr*)host->h_addr,
+            (LPVOID)requestBuffer, sizeof(requestBuffer),
+            &ipOptions,
+            replyBuffer, sizeof(replyBuffer),
+            3000);
+        if (replyCount == 0) {
+            printf("IcmpSendEcho() failed: %d\n", GetLastError());
+            break;
+        }
+        else if (replyCount != 1) {
+            printf("Got extra replies: %d\n", replyCount);
+            break;
+        }
+
+        if (replies[0].Status == IP_TTL_EXPIRED_TRANSIT) {
+            // Get the IP address that responded to us
+            printf("Hop %d: %s\n", ttl, inet_ntoa(*(IN_ADDR*)&replies[0].Address));
+            hopAddress[ttl - 1] = *(IN_ADDR*)&replies[0].Address;
+        }
+        else {
+            // Bail on anything else
+            printf("Hop %d: %s (error %d)\n", ttl, inet_ntoa(*(IN_ADDR*)&replies[0].Address), replies[0].Status);
+            *hopAddressCount = ttl - 1;
+            break;
+        }
+    }
+
+    IcmpCloseHandle(icmpFile);
+
+    return true;
+}