From 0cf09d643581aeea3f6d5949217cc8cd7b557471 Mon Sep 17 00:00:00 2001
From: Jeff Becker <jeff@i2p.rocks>
Date: Tue, 11 Jun 2019 15:42:11 -0400
Subject: [PATCH] make exits support v6 probably

---
 llarp/handlers/exit.cpp | 20 +++++++++++++++++++-
 llarp/handlers/exit.hpp |  4 ++++
 llarp/handlers/tun.cpp  | 13 ++++++++-----
 3 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/llarp/handlers/exit.cpp b/llarp/handlers/exit.cpp
index 371b88930..0470077b4 100644
--- a/llarp/handlers/exit.cpp
+++ b/llarp/handlers/exit.cpp
@@ -57,6 +57,12 @@ namespace llarp
       return obj;
     }
 
+    bool
+    ExitEndpoint::SupportsV6() const
+    {
+      return m_UseV6;
+    }
+
     bool
     ExitEndpoint::ShouldHookDNSMessage(const dns::Message &msg) const
     {
@@ -86,6 +92,7 @@ namespace llarp
     ExitEndpoint::HandleHookedDNSMessage(
         dns::Message &&msg, std::function< void(dns::Message) > reply)
     {
+     
       if(msg.questions[0].qtype == dns::qTypePTR)
       {
         huint32_t ip;
@@ -132,6 +139,7 @@ namespace llarp
               || msg.questions[0].qtype == dns::qTypeAAAA)
       {
         const bool isV6 = msg.questions[0].qtype == dns::qTypeAAAA;
+        const bool isV4 = msg.questions[0].qtype == dns::qTypeA;
         if(msg.questions[0].IsName("random.snode"))
         {
           RouterID random;
@@ -158,7 +166,11 @@ namespace llarp
         {
           huint128_t ip;
           PubKey pubKey(r);
-          if(m_SNodeKeys.find(pubKey) == m_SNodeKeys.end())
+          if(isV4 && SupportsV6())
+          {
+            msg.hdr_fields |= dns::flags_QR | dns::flags_AA | dns::flags_RA;
+          }
+          else if(m_SNodeKeys.find(pubKey) == m_SNodeKeys.end())
           {
             // we do not have it mapped
             // map it
@@ -539,8 +551,14 @@ namespace llarp
         }
         else if(m_IfAddr.FromString(host_str))
         {
+          m_UseV6 = true;
           m_OurRange.netmask_bits = netmask_ipv6_bits(m_Tun.netmask);
         }
+        else
+        {
+          LogError(Name(), " invalid ifaddr: ", v);
+          return false;
+        }
         m_OurRange.addr = m_IfAddr;
         m_NextAddr      = m_IfAddr;
         m_HigestAddr    = m_IfAddr | (~m_OurRange.netmask_bits);
diff --git a/llarp/handlers/exit.hpp b/llarp/handlers/exit.hpp
index 461a406aa..e96409468 100644
--- a/llarp/handlers/exit.hpp
+++ b/llarp/handlers/exit.hpp
@@ -32,6 +32,9 @@ namespace llarp
       util::StatusObject
       ExtractStatus() const;
 
+      bool
+      SupportsV6() const;
+
       bool
       ShouldHookDNSMessage(const dns::Message& msg) const override;
 
@@ -177,6 +180,7 @@ namespace llarp
 
       /// internet to llarp packet queue
       PacketQueue_t m_InetToNetwork;
+      bool m_UseV6;
     };
   }  // namespace handlers
 }  // namespace llarp
diff --git a/llarp/handlers/tun.cpp b/llarp/handlers/tun.cpp
index 26fd604ef..7422680a5 100644
--- a/llarp/handlers/tun.cpp
+++ b/llarp/handlers/tun.cpp
@@ -366,7 +366,8 @@ namespace llarp
       else if(msg.questions[0].qtype == dns::qTypeA
               || msg.questions[0].qtype == dns::qTypeAAAA)
       {
-        const bool isV6 = msg.questions[0].qtype == dns::qTypeAAAA && SupportsV6();
+        const bool isV6 =
+            msg.questions[0].qtype == dns::qTypeAAAA && SupportsV6();
         const bool isV4 = msg.questions[0].qtype == dns::qTypeA;
         llarp::service::Address addr;
         // on MacOS this is a typeA query
@@ -404,7 +405,7 @@ namespace llarp
           else if(HasAddress(addr))
           {
             huint128_t ip = ObtainIPForAddr(addr, false);
-            msg.AddINReply(ip, isV6); 
+            msg.AddINReply(ip, isV6);
           }
           else
           {
@@ -414,7 +415,8 @@ namespace llarp
             return EnsurePathToService(
                 addr,
                 [=](const Address &, OutboundContext *ctx) {
-                  SendDNSReply(addr, ctx, replyMsg, reply, false, isV6 || !isV4);
+                  SendDNSReply(addr, ctx, replyMsg, reply, false,
+                               isV6 || !isV4);
                 },
                 2000);
           }
@@ -778,7 +780,8 @@ namespace llarp
               {
                 return false;
               }
-              pkt.UpdateV4Address(net::IPPacket::TruncateV6(themIP), net::IPPacket::TruncateV6(usIP));
+              pkt.UpdateV4Address(net::IPPacket::TruncateV6(themIP),
+                                  net::IPPacket::TruncateV6(usIP));
             }
             else if(pkt.IsV6())
             {
@@ -871,7 +874,7 @@ namespace llarp
     void
     TunEndpoint::MarkIPActive(huint128_t ip)
     {
-      llarp::LogDebug(Name(), " address " , ip,  " is active");
+      llarp::LogDebug(Name(), " address ", ip, " is active");
       m_IPActivity[ip] = std::max(Now(), m_IPActivity[ip]);
     }