pdns/recpacketcache.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #ifndef PDNS_RECPACKETCACHE_HH
  23 #define PDNS_RECPACKETCACHE_HH
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28 #include "rec-protobuf.hh"
  29
  30 #include <string>
  31 #include <set>
  32 #include <inttypes.h>
  33 #include "dns.hh"
  34 #include "namespaces.hh"
  35 #include <iostream>
  36 #include <boost/multi_index_container.hpp>
  37 #include <boost/multi_index/ordered_index.hpp>
  38 #include <boost/multi_index/hashed_index.hpp>
  39 #include <boost/tuple/tuple_comparison.hpp>
  40 #include <boost/multi_index/sequenced_index.hpp>
  41
  42 #include "packetcache.hh"
  43
  44
  45
  46 using namespace ::boost::multi_index;
  47
  48 //! Stores whole packets, ready for lobbing back at the client. Not threadsafe.
  49 /* Note: we store answers as value AND KEY, and with careful work, we make sure that
  50    you can use a query as a key too. But query and answer must compare as identical!
  51
  52    This precludes doing anything smart with EDNS directly from the packet */
  53 class RecursorPacketCache: public PacketCache
  54 {
  55 public:
  56   RecursorPacketCache();
  57   bool getResponsePacket(unsigned int tag, const std::string& queryPacket, time_t now, std::string* responsePacket, uint32_t* age, uint32_t* qhash);
  58   bool getResponsePacket(unsigned int tag, const std::string& queryPacket, time_t now, std::string* responsePacket, uint32_t* age, uint32_t* qhash, RecProtoBufMessage* protobufMessage);
  59   bool getResponsePacket(unsigned int tag, const std::string& queryPacket, const DNSName& qname, uint16_t qtype, uint16_t qclass, time_t now, std::string* responsePacket, uint32_t* age, uint32_t* qhash);
  60   bool getResponsePacket(unsigned int tag, const std::string& queryPacket, const DNSName& qname, uint16_t qtype, uint16_t qclass, time_t now, std::string* responsePacket, uint32_t* age, uint32_t* qhash, RecProtoBufMessage* protobufMessage);
  61   void insertResponsePacket(unsigned int tag, uint32_t qhash, const DNSName& qname, uint16_t qtype, uint16_t qclass, const std::string& responsePacket, time_t now, uint32_t ttl);
  62   void insertResponsePacket(unsigned int tag, uint32_t qhash, const DNSName& qname, uint16_t qtype, uint16_t qclass, const std::string& responsePacket, time_t now, uint32_t ttl, const RecProtoBufMessage* protobufMessage);
  63   void doPruneTo(unsigned int maxSize=250000);
  64   uint64_t doDump(int fd);
  65   int doWipePacketCache(const DNSName& name, uint16_t qtype=0xffff, bool subtree=false);
  66
  67   void prune();
  68   uint64_t d_hits, d_misses;
  69   uint64_t size();
  70   uint64_t bytes();
  71
  72 private:
  73   struct HashTag {};
  74   struct NameTag {};
  75   struct Entry
  76   {
  77     mutable time_t d_ttd;
  78     mutable time_t d_creation; // so we can 'age' our packets
  79     DNSName d_name;
  80     uint16_t d_type;
  81     uint16_t d_class;
  82     mutable std::string d_packet; // "I know what I am doing"
  83 #ifdef HAVE_PROTOBUF
  84     mutable RecProtoBufMessage d_protobufMessage;
  85 #endif
  86     uint32_t d_qhash;
  87     uint32_t d_tag;
  88     inline bool operator<(const struct Entry& rhs) const;
  89
  90     time_t getTTD() const
  91     {
  92       return d_ttd;
  93     }
  94   };
  95
  96   typedef multi_index_container<
  97     Entry,
  98     indexed_by  <
  99       hashed_non_unique<tag<HashTag>, composite_key<Entry, member<Entry,uint32_t,&Entry::d_tag>, member<Entry,uint32_t,&Entry::d_qhash> > >,
 100       sequenced<> ,
 101       ordered_non_unique<tag<NameTag>, member<Entry,DNSName,&Entry::d_name>, CanonDNSNameCompare >
 102       >
 103   > packetCache_t;
 104
 105   packetCache_t d_packetCache;
 106
 107   bool checkResponseMatches(std::pair<packetCache_t::index<HashTag>::type::iterator, packetCache_t::index<HashTag>::type::iterator> range, const std::string& queryPacket, const DNSName& qname, uint16_t qtype, uint16_t qclass, time_t now, std::string* responsePacket, uint32_t* age, RecProtoBufMessage* protobufMessage);
 108
 109 public:
 110   void preRemoval(const Entry& entry)
 111   {
 112   }
 113 };
 114
 115 #endif