Changeset 1433

Timestamp:

10/13/09 21:33:08 (5 months ago)

Author:

ahu

Message:

add simple packetcache to recursor (thread safe)

Location:

trunk/pdns/pdns

Files:

• Makefile.am (modified) (3 diffs)
• dist-recursor (modified) (2 diffs)
• dns.cc (added)
• dns.hh (modified) (1 diff)
• pdns_recursor.cc (modified) (15 diffs)
• recpacketcache.cc (added)
• recpacketcache.hh (added)

trunk/pdns/pdns/Makefile.am

@@ -30 +30 @@
 session.cc session.hh misc.cc misc.hh receiver.cc ueberbackend.cc \
 dynlistener.cc dynlistener.hh  dynhandler.cc dynhandler.hh  \
-resolver.hh resolver.cc communicator.cc communicator.hh dnsproxy.cc \
+resolver.hh resolver.cc slavecommunicator.cc mastercommunicator.cc communicator.hh dnsproxy.cc \
 dnsproxy.hh randombackend.cc unix_utility.cc common_startup.cc \
 utility.hh iputils.hh common_startup.hh unix_semaphore.cc \
@@ -42 +42 @@
 aes/aescrypt.c aes/aes.h aes/aeskey.c aes/aes_modes.c aes/aesopt.h \
 aes/aestab.c aes/aestab.h aes/brg_endian.h aes/brg_types.h aes/dns_random.cc \
-randomhelper.cc
+randomhelper.cc 
 
 #
@@ -127 +127 @@
 rec_channel_rec.cc selectmplexer.cc epollmplexer.cc sillyrecords.cc htimer.cc htimer.hh \
 aes/dns_random.cc aes/aescrypt.c aes/aeskey.c aes/aestab.c aes/aes_modes.c \
-lua-pdns-recursor.cc lua-pdns-recursor.hh randomhelper.cc
+lua-pdns-recursor.cc lua-pdns-recursor.hh randomhelper.cc  \
+recpacketcache.cc recpacketcache.hh dns.cc
 
 if NEDMALLOC

trunk/pdns/pdns/dist-recursor

@@ -7 +7 @@
 mplexer.hh win32_mtasker.hh win32_utility.cc ntservice.hh singleton.hh \
 recursorservice.hh dns_random.hh lua-pdns-recursor.hh namespaces.hh \
-md5.hh"
+recpacketcache.hh"
 
 CFILES="syncres.cc  misc.cc unix_utility.cc qtype.cc \
@@ -16 +16 @@
 win32_mtasker.cc win32_rec_channel.cc win32_logger.cc ntservice.cc \
 recursorservice.cc sillyrecords.cc lua-pdns-recursor.cc randomhelper.cc \
-md5.cc devpollmplexer.cc"
+devpollmplexer.cc recpacketcache.cc dns.cc"
 
 cd docs

trunk/pdns/pdns/dns.hh

@@ -249 +249 @@
 #define L theL()
 extern time_t s_starttime;
-
-#endif
+std::string questionExpand(const char* packet, uint16_t len, uint16_t& type);
+#endif

trunk/pdns/pdns/pdns_recursor.cc

@@ -26 +26 @@
 
 #include <boost/foreach.hpp>
+#include "recpacketcache.hh"
 #include "utility.hh" 
 #include "dns_random.hh"
-#include "md5.hh"
 #include <iostream>
 #include <errno.h>
@@ -74 +74 @@
 bool g_logCommonErrors;
 shared_ptr<PowerDNSLua> g_pdl;
+RecursorPacketCache g_packetCache;
+
 #include "namespaces.hh"
 
@@ -80 +82 @@
 #include <semaphore.h>
 #endif
-map<string, string> g_packetCache;
+
 
 MemRecursorCache RC;
@@ -95 +97 @@
 map<int, ComboAddress> g_listenSocketsAddresses; // is shared across all threads right now
 struct DNSComboWriter {
-  DNSComboWriter(const char* data, uint16_t len, const std::string& hash, const struct timeval& now) : d_mdp(data, len), d_now(now), 
-                                                                                                       d_hash(hash), d_tcp(false), d_socket(-1)
+  DNSComboWriter(const char* data, uint16_t len, const struct timeval& now) : d_mdp(data, len), d_now(now), 
+                                                                                                        d_tcp(false), d_socket(-1)
   {}
   MOADNSParser d_mdp;
@@ -116 +118 @@
   struct timeval d_now;
   ComboAddress d_remote;
-  string d_hash;
   bool d_tcp;
   int d_socket;
@@ -603 +604 @@
        }
     }
+    uint32_t minTTL=numeric_limits<uint32_t>::max();
     if(res<0) {
       pw.getHeader()->rcode=RCode::ServFail;
@@ -622 +624 @@
       }
       
+
       if(ret.size()) {
         shuffle(ret);
@@ -628 +631 @@
         for(vector<DNSResourceRecord>::const_iterator i=ret.begin(); i!=ret.end(); ++i) {
           pw.startRecord(i->qname, i->qtype.getCode(), i->ttl, i->qclass, (DNSPacketWriter::Place)i->d_place); 
-          
+          minTTL = min(minTTL, i->ttl);
           if(i->qtype.getCode() == QType::A) { // blast out A record w/o doing whole dnswriter thing
             uint32_t ip=0;
@@ -651 +654 @@
     if(!dc->d_tcp) {
       sendto(dc->d_socket, (const char*)&*packet.begin(), packet.size(), 0, (struct sockaddr *)(&dc->d_remote), dc->d_remote.getSocklen());
-      if(pw.getHeader()->rcode==RCode::NoError || pw.getHeader()->rcode==RCode::NXDomain )
-        g_packetCache[dc->d_hash]=string((const char*)&*packet.begin(), packet.size());
-      else 
-        ; //    cerr<<"rcode:" <<(int)pw.getHeader()->rcode<<endl;
+      g_packetCache.insertResponsePacket(string((const char*)&*packet.begin(), packet.size()), g_now.tv_sec, 
+                                         min(minTTL, 
+                                             pw.getHeader()->rcode == RCode::ServFail ? (uint32_t)60 : (uint32_t) 3600
+                                             )
+                                         );
     }
     else {
@@ -800 +804 @@
       DNSComboWriter* dc=0;
       try {
-        dc=new DNSComboWriter(tconn.data, tconn.qlen, string(), g_now);
+        dc=new DNSComboWriter(tconn.data, tconn.qlen, g_now);
       }
       catch(MOADNSException &mde) {
@@ -867 +871 @@
 }
  
-void questionExpand(const char* packet, uint16_t len, char* qname, int maxlen, uint16_t& type)
-{
-  type=0;
-  const unsigned char* end=(const unsigned char*)packet+len;
-  unsigned char* lbegin=(unsigned char*)packet+12;
-  unsigned char* pos=lbegin;
-  unsigned char labellen;
-
-  // 3www4ds9a2nl0
-  char *dst=qname;
-  char* lend=dst + maxlen;
-  
-  if(!*pos)
-    *dst++='.';
-
-  while((labellen=*pos++) && pos < end) { // "scan and copy"
-    if(dst >= lend)
-      throw runtime_error("Label length exceeded destination length");
-    for(;labellen;--labellen)
-      *dst++ = *pos++;
-    *dst++='.';
-  }
-  *dst=0;
-
-  if(pos + labellen + 2 <= end)  // is this correct XXX FIXME?
-    type=(*pos)*256 + *(pos+1);
-
-
-  //  cerr<<"Returning: '"<< string(tmp+1, pos) <<"'\n";
-}
-
-string questionExpand(const char* packet, uint16_t len, uint16_t& type)
-{
-  char tmp[512];
-  questionExpand(packet, len, tmp, sizeof(tmp), type);
-  return tmp;
-}
 
 
@@ -936 +903 @@
       else {
         ++g_stats.qcounter;
-        uint16_t tmp = dh->id;
-        dh->id=0;
-        
-        MD5Summer md5s;
-        md5s.feed(data, len);
-        string hash = md5s.get();
-        //      cerr<<"hash: "<<makeHexDump(hash)<<endl;
-        dh->id=tmp;
-
-        if(g_packetCache.count(hash)) {
+
+        string response;
+        if(g_packetCache.getResponsePacket(string(data, len), g_now.tv_sec, &response)) {
           g_stats.packetCacheHits++;
           SyncRes::s_queries++;
-          string reply=g_packetCache[hash]; 
-          ((struct dnsheader*)reply.c_str())->id=tmp;
-          sendto(fd, reply.c_str(), reply.length(), 0, (struct sockaddr*) &fromaddr, fromaddr.getSocklen());
+          sendto(fd, response.c_str(), response.length(), 0, (struct sockaddr*) &fromaddr, fromaddr.getSocklen());
           return;
         }
 
-        DNSComboWriter* dc = new DNSComboWriter(data, len, hash, g_now);
+        DNSComboWriter* dc = new DNSComboWriter(data, len, g_now);
         dc->setSocket(fd);
         dc->setRemote(&fromaddr);
@@ -1658 +1616 @@
   if(::arg().mustDo("export-etc-hosts")) {
     string line;
-    string fname;
-    
-    ifstream ifs("/etc/hosts");
+    string fname=::arg()["etc-hosts-file"];
+    
+    ifstream ifs(fname.c_str());
     if(!ifs) {
       L<<Logger::Warning<<"Could not open /etc/hosts for reading"<<endl;
@@ -2015 +1973 @@
     Utility::gettimeofday(&g_now, 0);
     t_fdm->run(&g_now);
-    Utility::gettimeofday(&g_now, 0);
+    // 'run' updates g_now for us
 
     if(listenOnTCP) {
@@ -2140 +2098 @@
     ::arg().set("forward-zones-file", "File with domain=ip pairs for forwarding")="";
     ::arg().set("export-etc-hosts", "If we should serve up contents from /etc/hosts")="off";
+    ::arg().set("etc-hosts-file", "Path to 'hosts' file")="/etc/hosts";
     ::arg().set("serve-rfc1918", "If we should be authoritative for RFC 1918 private IP space")="";
     ::arg().set("auth-can-lower-ttl", "If we follow RFC 2181 to the letter, an authoritative server can lower the TTL of NS records")="off";