Changeset 699

Timestamp:

04/14/06 13:26:50 (4 years ago)

Author:

ahu

Message:

implement stunningly cool spoofing protection, plus spoofer in dnspbench

Location:

trunk/pdns/pdns

Files:

• dnsparser.cc (modified) (1 diff)
• dnspbench.cc (modified) (2 diffs)
• dnswriter.cc (modified) (1 diff)
• mtasker.cc (modified) (3 diffs)
• mtasker.hh (modified) (5 diffs)
• pdns_recursor.cc (modified) (3 diffs)
• rcpgenerator.cc (modified) (1 diff)
• syncres.hh (modified) (2 diffs)

trunk/pdns/pdns/dnsparser.cc

@@ -379 +379 @@
     }
     else {
+      // should check for . here and replace by \.
       ret.append(&content.at(frompos), &content.at(frompos+labellen));
       ret.append(1,'.');

trunk/pdns/pdns/dnspbench.cc

@@ -45 +45 @@
   reportAllTypes();
 
-#if 0
   Socket s(InterNetwork, Datagram);
+  
+  IPEndpoint rem("127.0.0.1",1232), loc("213.156.2.1", 53);
+  s.bind(loc);
 
   vector<uint8_t> vpacket;
-  string domain="www.ds9a.nl";
+  string domain="ds9a.nl";
   uint16_t type=1;
 
-  for(unsigned int n=0; n < 1000000; ++n) {
+  for(unsigned int n=0; n < 65536; ++n) {
     DNSPacketWriter pw(vpacket, domain, type);
     
     pw.getHeader()->rd=1;
+    pw.getHeader()->qr=1;
     pw.getHeader()->id=n;
+    ARecordContent arc("1.2.3.4");
+    pw.startRecord("ds9a.nl", 1, 9999, 1, DNSPacketWriter::ANSWER);
+    arc.toPacket(pw);
     pw.commit();
-    IPEndpoint rem("127.0.0.1",5300);
+
     string spacket((char*)(&*vpacket.begin()), vpacket.size());
     s.sendTo(spacket, rem);
   }
 
-
   return 0; 
-#endif
+#if 0
 
   vector<uint8_t> packet;
@@ -83 +88 @@
   shared_ptr<DNSRecordContent> regen=DNSRecordContent::unserialize(argv[1], type, record);
   cerr<<"Out: "<<argv[1]<<" IN "<<argv[2]<<" "<<regen->getZoneRepresentation()<<endl;
+#endif
 }
 catch(exception& e)

trunk/pdns/pdns/dnswriter.cc

@@ -124 +124 @@
   typedef vector<pair<unsigned int, unsigned int> > parts_t;
   parts_t parts;
-  vstringtok(parts, label, ".");
+  vstringtok(parts, label, "."); // XXX FIXME this should deal with escaped .
   
   // d_stuff is amount of stuff that is yet to be written out - the dnsrecordheader for example

trunk/pdns/pdns/mtasker.cc

@@ -159 +159 @@
 */
 
-template<class EventKey, class EventVal>int MTasker<EventKey,EventVal>::waitEvent(const EventKey &key, EventVal *val, unsigned int timeout)
+template<class EventKey, class EventVal>int MTasker<EventKey,EventVal>::waitEvent(EventKey &key, EventVal *val, unsigned int timeout)
 {
   if(d_waiters.count(key)) { // there was already an exact same waiter
@@ -181 +181 @@
     *val=d_waitval;
   d_tid=w.tid;
+  key=d_eventkey;
   return d_waitstatus;
 }
@@ -217 +218 @@
   ucontext_t *userspace=waiter->context;
   d_tid=waiter->tid;         // set tid 
-  
+  d_eventkey=waiter->key;        // pass waitEvent the exact key it was woken for
   d_waiters.erase(waiter);             // removes the waitpoint 
   if(swapcontext(&d_kernel,userspace)) { // swaps back to the above point 'A'

trunk/pdns/pdns/mtasker.hh

@@ -51 +51 @@
   std::queue<int> d_zombiesQueue;
 
+
+  typedef std::map<int, ucontext_t*> mthreads_t;
+  mthreads_t d_threads;
+  int d_tid;
+  int d_maxtid;
+  size_t d_stacksize;
+
+  EventVal d_waitval;
+  enum {Error=-1,TimeOut=0,Answer} d_waitstatus;
+
+public:
   struct Waiter
   {
@@ -58 +69 @@
     int tid;
   };
-
-  //  typedef std::map<EventKey,Waiter> waiters_t;
 
   typedef multi_index_container<
@@ -71 +80 @@
   waiters_t d_waiters;
 
-  typedef std::map<int, ucontext_t*> mthreads_t;
-  mthreads_t d_threads;
-  int d_tid;
-  int d_maxtid;
-  size_t d_stacksize;
-
-  EventVal d_waitval;
-  enum {Error=-1,TimeOut=0,Answer} d_waitstatus;
-
-public:
   //! Constructor
   /** Constructor with a small default stacksize. If any of your threads exceeds this stack, your application will crash. 
@@ -92 +91 @@
 
   typedef void tfunc_t(void *); //!< type of the pointer that starts a thread 
-  int waitEvent(const EventKey &key, EventVal *val=0, unsigned int timeout=0);
+  int waitEvent(EventKey &key, EventVal *val=0, unsigned int timeout=0);
   void yield();
   int sendEvent(const EventKey& key, const EventVal* val=0);
@@ -104 +103 @@
 private:
   static void threadWrapper(MTasker *self, tfunc_t *tf, int tid, void* val);
+  EventKey d_eventkey;   // for waitEvent, contains exact key it was awoken for
 };
 #include "mtasker.cc"

trunk/pdns/pdns/pdns_recursor.cc

@@ -128 +128 @@
 static map<int,PacketID> d_tcpclientreadsocks, d_tcpclientwritesocks;
 
-MTasker<PacketID,string>* MT;
+typedef MTasker<PacketID,string> MT_t;
+MT_t* MT;
 
 int asendtcp(const string& data, Socket* sock) 
@@ -183 +184 @@
     *d_len=packet.size();
     memcpy(data,packet.c_str(),min(len,*d_len));
+    if(pident.nearMisses > 100) {
+      L<<Logger::Error<<"Too many ("<<pident.nearMisses<<") bogus answers came in from "<<sockAddrToString((struct sockaddr_in*)toaddr, sizeof(pident.remote))<<", assuming spoof attempt."<<endl;
+      return -1;
+    }
   }
   return ret;
@@ -1000 +1005 @@
                     L<<Logger::Warning<<"Discarding unexpected packet from "<<sockAddrToString((struct sockaddr_in*) &fromaddr, addrlen)<<endl;
                   g_stats.unexpectedCount++;
+                  
+                  for(MT_t::waiters_t::iterator mthread=MT->d_waiters.begin(); mthread!=MT->d_waiters.end(); ++mthread) {
+                    if(!memcmp(&mthread->key.remote.sin_addr, &pident.remote.sin_addr, sizeof(pident.remote.sin_addr))) {
+                      mthread->key.nearMisses++;
+                    }
+                  }
                 }
               }

trunk/pdns/pdns/rcpgenerator.cc

@@ -98 +98 @@
 }
 
-
-void RecordTextReader::xfrLabel(string& val, bool)
+void RecordTextReader::xfrLabel(string& val, bool) 
 {
   skipSpaces();

trunk/pdns/pdns/syncres.hh

@@ -318 +318 @@
 struct PacketID
 {
-  PacketID() : sock(0), inNeeded(0), outPos(0)
+  PacketID() : sock(0), inNeeded(0), outPos(0), nearMisses(0)
   {}
 
@@ -330 +330 @@
   string outMSG; // the outgoing message that needs to be sent
   string::size_type outPos;    // how far we are along in the outMSG
+
+  mutable uint32_t nearMisses; // number of near misses - host correct, id wrong
 
   bool operator<(const PacketID& b) const