From 7eafc52fef02ca87b5564de584d672aa51eac2a4 Mon Sep 17 00:00:00 2001
From: bert hubert <bert.hubert@netherlabs.nl>
Date: Mon, 11 Jan 2016 13:59:35 +0100
Subject: [PATCH] implement ixfr-falls-back-to-axfr support

---
 pdns/filterpo.cc | 10 ++++++++++
 pdns/ixfr.cc     | 10 ++++++++--
 pdns/ixplore.cc  | 12 ++++++++++--
 pdns/reczones.cc |  5 ++++-
 4 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/pdns/filterpo.cc b/pdns/filterpo.cc
index c50f7e55c..19b0210b7 100644
--- a/pdns/filterpo.cc
+++ b/pdns/filterpo.cc
@@ -101,6 +101,16 @@ void DNSFilterEngine::assureZones(int zone)
     d_zones.resize(zone+1);
 }
 
+void DNSFilterEngine::clear(int zone)
+{
+  assureZones(zone);
+  auto& z = d_zones[zone];
+  z.qpolAddr.clear();
+  z.postpolAddr.clear();
+  z.propolName.clear();
+  z.qpolName.clear();
+}
+
 void DNSFilterEngine::addClientTrigger(const Netmask& nm, Policy pol, int zone)
 {
   assureZones(zone);
diff --git a/pdns/ixfr.cc b/pdns/ixfr.cc
index c9bb5e48f..ad4ef2d6d 100644
--- a/pdns/ixfr.cc
+++ b/pdns/ixfr.cc
@@ -4,7 +4,9 @@
 #include "dnsrecords.hh"
 #include "dnssecinfra.hh"
 
-vector<pair<vector<DNSRecord>, vector<DNSRecord> > >   getIXFRDeltas(const ComboAddress& master, const DNSName& zone, const DNSRecord& oursr, const TSIGTriplet& tt)
+
+// if you the remove,add pairs always remove a SOA and add a new one. If you get an empty remove, it means you got an AXFR!
+vector<pair<vector<DNSRecord>, vector<DNSRecord> > > getIXFRDeltas(const ComboAddress& master, const DNSName& zone, const DNSRecord& oursr, const TSIGTriplet& tt)
 {
   vector<pair<vector<DNSRecord>, vector<DNSRecord> > >  ret;
   vector<uint8_t> packet;
@@ -82,10 +84,14 @@ vector<pair<vector<DNSRecord>, vector<DNSRecord> > >   getIXFRDeltas(const Combo
  done:;
   for(unsigned int pos = 1;pos < records.size();) {
     auto sr = std::dynamic_pointer_cast<SOARecordContent>(records[pos].d_content);
+    vector<DNSRecord> remove, add;
+    if(!sr) { // this is an actual AXFR!
+      return {{remove, records}};
+    }
     if(sr->d_st.serial == masterSOA->d_st.serial)
       break;
     
-    vector<DNSRecord> remove, add;
+
     remove.push_back(records[pos]); // this adds the SOA
     for(pos++; pos < records.size() && records[pos].d_type != QType::SOA; ++pos) {
       remove.push_back(records[pos]);
diff --git a/pdns/ixplore.cc b/pdns/ixplore.cc
index ca663495e..be45c1694 100644
--- a/pdns/ixplore.cc
+++ b/pdns/ixplore.cc
@@ -300,6 +300,7 @@ try
     cout<<"Got "<<deltas.size()<<" deltas, applying.."<<endl;
 
     for(const auto& delta : deltas) {
+    
       const auto& remove = delta.first;
       const auto& add = delta.second;
 
@@ -310,9 +311,17 @@ try
 	  newserial=std::dynamic_pointer_cast<SOARecordContent>(rr.d_content)->d_st.serial;
 	}
       }
+
       cout<<"This delta ("<<ourSerial<<" - "<<newserial<<") has "<<remove.size()<<" removals, "<<add.size()<<" additions"<<endl;
+      ofstream report(directory +"/delta."+std::to_string(ourSerial)+"-"+std::to_string(newserial));      
+      if(remove.empty()) {
+        cout<<"This delta is a whole new zone"<<endl;
+        report<<"- everything, whole new zone update follow"<<endl;
+        records.clear();
+      }
+
       bool stop=false;
-      ofstream report(directory +"/delta."+std::to_string(ourSerial)+"-"+std::to_string(newserial));
+
       for(const auto& rr : remove) {
 	report<<'-'<< (rr.d_name+zone) <<" IN "<<DNSRecordContent::NumberToType(rr.d_type)<<" "<<rr.d_content->getZoneRepresentation()<<endl;
 	auto range = records.equal_range(tie(rr.d_name, rr.d_type, rr.d_class, rr.d_content));
@@ -322,7 +331,6 @@ try
 	  report.flush();
 	}
 	records.erase(range.first, range.second);
-
       }
 
       for(const auto& rr : add) {
diff --git a/pdns/reczones.cc b/pdns/reczones.cc
index 9861a7183..698aecf5c 100644
--- a/pdns/reczones.cc
+++ b/pdns/reczones.cc
@@ -338,7 +338,10 @@ void RPZIXFRTracker(const ComboAddress& master, const DNSName& zone, const TSIGT
     for(const auto& delta : deltas) {
       const auto& remove = delta.first;
       const auto& add = delta.second;
-      
+      if(remove.empty()) {
+        L<<Logger::Warning<<"IXFR update is a whole new zone"<<endl;
+        luaconfsCopy.dfe.clear(0);
+      }
       for(const auto& rr : remove) { // should always contain the SOA
 	totremove++;
 	if(rr.d_type == QType::SOA) {
-- 
2.40.0