From 2b2e0007faa41d104b3bc16561d7d8b2ee6d7d2c Mon Sep 17 00:00:00 2001
From: Ryan Tharp <neuro@interx.net>
Date: Sat, 22 Sep 2018 03:25:16 -0700
Subject: [PATCH] active DNS relay (server/client) in tun interface

---
 include/llarp/handlers/tun.hpp |  9 +++++++++
 llarp/handlers/tun.cpp         | 33 ++++++++++++++++++++++++++++++---
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/include/llarp/handlers/tun.hpp b/include/llarp/handlers/tun.hpp
index 795b0509d..8d3a9ed42 100644
--- a/include/llarp/handlers/tun.hpp
+++ b/include/llarp/handlers/tun.hpp
@@ -5,6 +5,9 @@
 #include <llarp/ip.hpp>
 #include <llarp/service/endpoint.hpp>
 #include <llarp/threading.hpp>
+#include "dnsd.hpp"
+#include "dns_dotlokilookup.hpp"
+#include "dns_iptracker.hpp"
 
 namespace llarp
 {
@@ -110,6 +113,12 @@ namespace llarp
       /// up interface
       std::promise< bool > m_TunSetupResult;
 #endif
+      /// DNS server per tun
+      struct dnsd_context dnsd;
+      /// DNS loki lookup subsystem configuration (also holds optional iptracker
+      /// for netns)
+      struct dotLokiLookup dll;
+
       /// maps ip to service address
       std::unordered_map< uint32_t, service::Address > m_IPToAddr;
       /// maps service address to ip
diff --git a/llarp/handlers/tun.cpp b/llarp/handlers/tun.cpp
index ee6a13b98..fda84b15a 100644
--- a/llarp/handlers/tun.cpp
+++ b/llarp/handlers/tun.cpp
@@ -2,6 +2,8 @@
 #define __USE_MINGW_ANSI_STDIO 1
 #include <llarp/handlers/tun.hpp>
 #include "router.hpp"
+#include "dns_iptracker.hpp"
+#include "dns_dotlokilookup.hpp"
 
 namespace llarp
 {
@@ -16,9 +18,12 @@ namespace llarp
       tunif.netmask = DefaultTunNetmask;
       strncpy(tunif.ifaddr, DefaultTunSrcAddr, sizeof(tunif.ifaddr) - 1);
       strncpy(tunif.ifname, DefaultTunIfname, sizeof(tunif.ifname) - 1);
-      tunif.tick         = nullptr;
-      tunif.before_write = &tunifBeforeWrite;
-      tunif.recvpkt      = &tunifRecvPkt;
+      tunif.tick           = nullptr;
+      tunif.before_write   = &tunifBeforeWrite;
+      tunif.recvpkt        = &tunifRecvPkt;
+      this->dll.ip_tracker = nullptr;
+      this->dll.user       = this;
+      // this->dll.callback = std::bind(&TunEndpoint::MapAddress, this);
     }
 
     bool
@@ -82,6 +87,10 @@ namespace llarp
         llarp::LogInfo(Name() + " set ifaddr to ", addr, " with netmask ",
                        tunif.netmask);
         strncpy(tunif.ifaddr, addr.c_str(), sizeof(tunif.ifaddr) - 1);
+
+        // set up address in dotLokiLookup
+        // llarp::Addr tunIp;
+        // dns_iptracker_setup_dotLokiLookup(&this->dll, tunIp);
         return true;
       }
       return Endpoint::SetOption(k, v);
@@ -119,6 +128,15 @@ namespace llarp
         // set up networking in currrent thread if we are not isolated
         if(!SetupNetworking())
           return false;
+
+        llarp::LogInfo("Setting up global DNS IP tracker");
+        llarp::Addr tunIp;
+        dns_iptracker_setup_dotLokiLookup(&this->dll, tunIp);
+      }
+      else
+      {
+        llarp::LogInfo("Setting up per netns DNS IP tracker");
+        this->dll.ip_tracker = new dns_iptracker;
       }
       // wait for result for network setup
       llarp::LogInfo("waiting for tun interface...");
@@ -165,6 +183,15 @@ namespace llarp
 #ifndef _WIN32
       m_TunSetupResult.set_value(result);
 #endif
+      if(!llarp_dnsd_init(&this->dnsd, EndpointLogic(), EndpointNetLoop(),
+                          tunif.ifname, 53, "8.8.8.8", 53))
+      {
+        llarp::LogError("Couldnt init dns daemon");
+      }
+      // configure hook
+      dnsd.intercept = &llarp_dotlokilookup_handler;
+      // set dotLokiLookup (this->dll)
+      dnsd.user = &this->dll;
       return result;
     }