Changeset 683

Timestamp:

04/12/06 13:32:53 (7 years ago)

Author:

ahu

Message:

fix handling of truncated packets with partial records (like emitted by powerdns hehe)
fix empty PTR, CNAME and NS records (generally a bad idea anyhow)
fix up error reporting a lot

Location:

trunk/pdns/pdns

Files:

• dnsparser.cc (modified) (4 diffs)
• dnsparser.hh (modified) (1 diff)
• dnsrecords.hh (modified) (1 diff)
• lwres.cc (modified) (1 diff)
• pdns_recursor.cc (modified) (4 diffs)
• rcpgenerator.cc (modified) (2 diffs)
• recursor_cache.cc (modified) (1 diff)

trunk/pdns/pdns/dnsparser.cc

@@ -192 +192 @@
 
   PacketReader pr(d_content);
-
+  bool validPacket=false;
   try {
     for(n=0;n < d_header.qdcount; ++n) {
@@ -202 +202 @@
     struct dnsrecordheader ah;
     vector<unsigned char> record;
-    
+    validPacket=true;
     for(n=0;n < d_header.ancount + d_header.nscount + d_header.arcount; ++n) {
-      
       DNSRecord dr;
       
@@ -223 +222 @@
       dr.d_label=label;
       dr.d_clen=ah.d_clen;
-      
+
       dr.d_content=boost::shared_ptr<DNSRecordContent>(DNSRecordContent::mastermake(dr, pr));
       d_answers.push_back(make_pair(dr, pr.d_pos));
@@ -236 +235 @@
   }
   catch(out_of_range &re) {
-    throw MOADNSException("Error parsing packet of "+lexical_cast<string>(len)+" bytes, out of bounds: "+string(re.what()));
+    if(!(validPacket && d_header.tc)) // don't sweat it over truncated packets
+      throw MOADNSException("Error parsing packet of "+lexical_cast<string>(len)+" bytes (rd="+
+                            lexical_cast<string>(d_header.rd)+
+                            "), out of bounds: "+string(re.what()));
   }
 }

trunk/pdns/pdns/dnsparser.hh

@@ -55 +55 @@
 using namespace std;
 using namespace boost;
-typedef runtime_error MOADNSException;
+
+class MOADNSException : public runtime_error
+{
+public:
+  MOADNSException(const string& str) : runtime_error(str)
+  {}
+};
 
 struct dnsrecordheader

trunk/pdns/pdns/dnsrecords.hh

@@ -299 +299 @@
   }                                                                                                \
   catch(RecordTextException& rtr) {                                                                \
-    throw MOADNSParser("Parsing record content: "+string(rtr.what()));                             \
+    throw MOADNSException("Parsing record content: "+string(rtr.what()));                          \
   }                                                                                                \
 }                                                                                                  \

trunk/pdns/pdns/lwres.cc

@@ -158 +158 @@
   catch(exception &mde) {
     if(::arg().mustDo("log-common-errors"))
-      L<<Logger::Error<<"Unable to parse packet from remote server: "<<mde.what()<<"\n";
+      L<<Logger::Error<<"Unable to parse packet from remote server: "<<mde.what()<<endl;
   }
   catch(...) {

trunk/pdns/pdns/pdns_recursor.cc

@@ -293 +293 @@
 void startDoResolve(void *p)
 {
+  DNSComboWriter* dc=(DNSComboWriter *)p;
   try {
-    DNSComboWriter* dc=(DNSComboWriter *)p;
-
     uint16_t maxudpsize=512;
     MOADNSParser::EDNSOpts edo;
@@ -347 +346 @@
         for(vector<DNSResourceRecord>::const_iterator i=ret.begin();i!=ret.end();++i) {
           pw.startRecord(i->qname, i->qtype.getCode(), i->ttl, 1, (DNSPacketWriter::Place)i->d_place);
-          shared_ptr<DNSRecordContent> drc(DNSRecordContent::mastermake(i->qtype.getCode(), 1, i->content));  
+          
+          shared_ptr<DNSRecordContent> drc(DNSRecordContent::mastermake(i->qtype.getCode(), 1, i->content));
+          
           drc->toPacket(pw);
+        
           if(!dc->d_tcp && pw.size() > maxudpsize) {
             pw.rollback();
@@ -427 +429 @@
   catch(AhuException &ae) {
     L<<Logger::Error<<"startDoResolve problem: "<<ae.reason<<endl;
+  }
+  catch(MOADNSException& e) {
+    L<<Logger::Error<<"DNS parser error: "<<dc->d_mdp.d_qname<<", "<<e.what()<<endl;
   }
   catch(exception& e) {
@@ -969 +974 @@
             try {
               DNSComboWriter* dc = new DNSComboWriter(data, d_len, now);
-
+              
               dc->setRemote((struct sockaddr *)&fromaddr, addrlen);
 

trunk/pdns/pdns/rcpgenerator.cc

@@ -102 +102 @@
 {
   skipSpaces();
-
   val.clear();
   val.reserve(d_end - d_pos);
@@ -217 +216 @@
   while(d_pos < d_end && dns_isspace(d_string[d_pos]))
     d_pos++;
-
   if(d_pos == d_end)
     throw RecordTextException("missing field at the end of record content '"+d_string+"'");

trunk/pdns/pdns/recursor_cache.cc

@@ -88 +88 @@
       rr.content.append(1,'.');
     }
+    if(rr.content.empty())
+      rr.content=".";
   }
   else {
-    shared_ptr<DNSRecordContent> regen=DNSRecordContent::unserialize(qname,qt.getCode(), serial);
+    shared_ptr<DNSRecordContent> regen=DNSRecordContent::unserialize(qname, qt.getCode(), serial);
     rr.content=regen->getZoneRepresentation();
   }
-
   //  rr.content.reserve(0);
   //  rr.qname.reserve(0);