From: Pieter Lexis <pieter.lexis@powerdns.com>
Date: Fri, 10 Mar 2017 15:46:47 +0000 (+0100)
Subject: create a doSpecialNamesResolve function
X-Git-Tag: rec-4.1.0-alpha1~174^2~19
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=db50a7f476bacb3e442f6a53febde8a72fb0a92a;p=pdns

create a doSpecialNamesResolve function
---

diff --git a/pdns/syncres.cc b/pdns/syncres.cc
index 2eb4c0b6e..fd6368094 100644
--- a/pdns/syncres.cc
+++ b/pdns/syncres.cc
@@ -127,60 +127,84 @@ int SyncRes::beginResolve(const DNSName &qname, const QType &qtype, uint16_t qcl
   d_wasVariable=false;
   d_wasOutOfBand=false;
 
+  if (doSpecialNamesResolve(qname, qtype, qclass, ret))
+    return 0;
+
   if( (qtype.getCode() == QType::AXFR))
     return -1;
 
-  static const DNSName arpa("1.0.0.127.in-addr.arpa."), localhost("localhost."), 
-    versionbind("version.bind."), idserver("id.server."), versionpdns("version.pdns.");
+  if(qclass==QClass::ANY)
+    qclass=QClass::IN;
+  else if(qclass!=QClass::IN)
+    return -1;
 
-  if( (qtype.getCode()==QType::PTR && qname==arpa) ||
-      (qtype.getCode()==QType::A && qname==localhost)) {
-    ret.clear();
-    DNSRecord dr;
-    dr.d_name=qname;
-    dr.d_place = DNSResourceRecord::ANSWER;
-    dr.d_type=qtype.getCode();
-    dr.d_class=QClass::IN;
-    dr.d_ttl=86400;
-    if(qtype.getCode()==QType::PTR)
-      dr.d_content=shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::PTR, 1, "localhost."));
+  set<GetBestNSAnswer> beenthere;
+  int res=doResolve(qname, qtype, ret, 0, beenthere);
+  return res;
+}
+
+/*! Handles all special, built-in names
+ * Fills ret with an answer and returns true if it handled the query.
+ *
+ * Handles the following queries:
+ *
+ * - localhost. IN A
+ * - localhost. IN AAAA
+ * - 1.0.0.127.in-addr.arpa. IN PTR
+ * - 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa. IN PTR
+ * - version.bind. CH TXT
+ * - version.pdns. CH TXT
+ * - id.server. CH TXT
+ *
+ * TODO handle ANY
+ */
+bool SyncRes::doSpecialNamesResolve(const DNSName &qname, const QType &qtype, const uint16_t &qclass, vector<DNSRecord> &ret)
+{
+  static const DNSName arpa("1.0.0.127.in-addr.arpa."), ip6_arpa("1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa."),
+    localhost("localhost."), versionbind("version.bind."), idserver("id.server."), versionpdns("version.pdns.");
+
+  bool handled = false;
+  string content;
+
+  if (qtype.getCode()==QType::PTR && (qname==arpa || qname==ip6_arpa)) {
+    handled = true;
+    content = "localhost.";
+  }
+
+  if (qname == localhost) {
+    handled = true;
+    if (qtype==QType::A)
+      content = "127.0.0.1";
+    if (qtype==QType::AAAA)
+      content = "::1";
+  }
+
+  if (qclass==QClass::CHAOS && qtype==QType::TXT && (qname==versionbind || qname==idserver || qname==versionpdns)) {
+    handled = true;
+    if(qname==versionbind || qname==versionpdns)
+      content = "\""+::arg()["version-string"]+"\"";
     else
-      dr.d_content=shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::A, 1, "127.0.0.1"));
-    ret.push_back(dr);
-    d_wasOutOfBand=true;
-    return 0;
+      content = "\""+s_serverID+"\"";
   }
 
-  if(qclass==QClass::CHAOS && qtype.getCode()==QType::TXT &&
-        (qname==versionbind || qname==idserver || qname==versionpdns )
-     ) {
+  if (handled && !content.empty()) {
     ret.clear();
+    d_wasOutOfBand=true;
+
     DNSRecord dr;
-    dr.d_name=qname;
-    dr.d_type=qtype.getCode();
-    dr.d_class=qclass;
-    dr.d_ttl=86400;
+    dr.d_name = qname;
     dr.d_place = DNSResourceRecord::ANSWER;
-    if(qname==versionbind  || qname==versionpdns)
-      dr.d_content=shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::TXT, 3, "\""+::arg()["version-string"]+"\""));
-    else
-      dr.d_content=shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(QType::TXT, 3, "\""+s_serverID+"\""));
-
+    dr.d_type = qtype.getCode();
+    dr.d_class = qclass;
+    dr.d_ttl = 86400;
+    dr.d_content=shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(qtype.getCode(), qclass, content));
     ret.push_back(dr);
-    d_wasOutOfBand=true;
-    return 0;
   }
 
-  if(qclass==QClass::ANY)
-    qclass=QClass::IN;
-  else if(qclass!=QClass::IN)
-    return -1;
-
-  set<GetBestNSAnswer> beenthere;
-  int res=doResolve(qname, qtype, ret, 0, beenthere);
-  return res;
+  return handled;
 }
 
+
 //! This is the 'out of band resolver', in other words, the authoritative server
 bool SyncRes::doOOBResolve(const DNSName &qname, const QType &qtype, vector<DNSRecord>&ret, unsigned int depth, int& res)
 {
diff --git a/pdns/syncres.hh b/pdns/syncres.hh
index 344ef145f..8ca201da8 100644
--- a/pdns/syncres.hh
+++ b/pdns/syncres.hh
@@ -539,7 +539,8 @@ private:
   RCode::rcodes_ updateCacheFromRecords(const std::string& prefix, LWResult& lwr, const DNSName& qname, const DNSName& auth, NsSet& nameservers, const DNSName& tns, const boost::optional<Netmask>);
   bool processRecords(const std::string& prefix, const DNSName& qname, const QType& qtype, const DNSName& auth, LWResult& lwr, const bool sendRDQuery, vector<DNSRecord>& ret, set<DNSName>& nsset, DNSName& newtarget, DNSName& newauth, bool& realreferral, bool& negindic, bool& sawDS);
 
-private:
+  bool doSpecialNamesResolve(const DNSName &qname, const QType &qtype, const uint16_t &qclass, vector<DNSRecord> &ret);
+
   ostringstream d_trace;
   shared_ptr<RecursorLua4> d_pdl;
   string d_prefix;