pdns/dns.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 #pragma once
  23 #include <boost/multi_index_container.hpp>
  24 #include <boost/multi_index/ordered_index.hpp>
  25 #include <boost/tuple/tuple_comparison.hpp>
  26 #include <boost/multi_index/key_extractors.hpp>
  27 #include <boost/multi_index/sequenced_index.hpp>
  28 #include "qtype.hh"
  29 #include "dnsname.hh"
  30 #include <time.h>
  31 #include <sys/types.h>
  32 class DNSBackend;
  33 struct DNSRecord;
  34
  35 struct SOAData
  36 {
  37   SOAData() : ttl(0), serial(0), refresh(0), retry(0), expire(0), default_ttl(0), db(0), domain_id(-1), scopeMask(0) {};
  38
  39   DNSName qname;
  40   DNSName nameserver;
  41   DNSName hostmaster;
  42   uint32_t ttl;
  43   uint32_t serial;
  44   uint32_t refresh;
  45   uint32_t retry;
  46   uint32_t expire;
  47   uint32_t default_ttl;
  48   DNSBackend *db;
  49   int domain_id;
  50   uint8_t scopeMask;
  51 };
  52
  53 class RCode
  54 {
  55 public:
  56   enum rcodes_ { NoError=0, FormErr=1, ServFail=2, NXDomain=3, NotImp=4, Refused=5, YXDomain=6, YXRRSet=7, NXRRSet=8, NotAuth=9, NotZone=10};
  57   static std::string to_s(unsigned short rcode);
  58   static std::vector<std::string> rcodes_s;
  59 };
  60
  61 class Opcode
  62 {
  63 public:
  64   enum { Query=0, IQuery=1, Status=2, Notify=4, Update=5 };
  65 };
  66
  67 // enum for policy decisions, used by both auth and recursor. Not all values supported everywhere.
  68 namespace PolicyDecision { enum returnTypes { PASS=-1, DROP=-2, TRUNCATE=-3 }; };
  69
  70 //! This class represents a resource record
  71 class DNSResourceRecord
  72 {
  73 public:
  74   DNSResourceRecord() : last_modified(0), ttl(0), signttl(0), domain_id(-1), qclass(1), scopeMask(0), auth(1), disabled(0) {};
  75   ~DNSResourceRecord(){};
  76   static DNSResourceRecord fromWire(const DNSRecord& d);
  77
  78   enum Place : uint8_t {QUESTION=0, ANSWER=1, AUTHORITY=2, ADDITIONAL=3}; //!< Type describing the positioning within, say, a DNSPacket
  79
  80   void setContent(const string& content);
  81   string getZoneRepresentation(bool noDot=false) const;
  82
  83   // data
  84   DNSName qname; //!< the name of this record, for example: www.powerdns.com
  85   DNSName wildcardname;
  86   string content; //!< what this record points to. Example: 10.1.2.3
  87
  88   // Aligned on 8-byte boundries on systems where time_t is 8 bytes and int
  89   // is 4 bytes, aka modern linux on x86_64
  90   time_t last_modified; //!< For autocalculating SOA serial numbers - the backend needs to fill this in
  91
  92   uint32_t ttl; //!< Time To Live of this record
  93   uint32_t signttl; //!< If non-zero, use this TTL as original TTL in the RRSIG
  94
  95   int domain_id; //!< If a backend implements this, the domain_id of the zone this record is in
  96   QType qtype; //!< qtype of this record, ie A, CNAME, MX etc
  97   uint16_t qclass; //!< class of this record
  98
  99   uint8_t scopeMask;
 100   bool auth;
 101   bool disabled;
 102
 103   bool operator==(const DNSResourceRecord& rhs);
 104
 105   bool operator<(const DNSResourceRecord &b) const
 106   {
 107     if(qname < b.qname)
 108       return true;
 109     if(qname == b.qname)
 110       return(content < b.content);
 111     return false;
 112   }
 113 };
 114
 115 #define GCCPACKATTRIBUTE __attribute__((packed))
 116
 117 struct dnsrecordheader
 118 {
 119   uint16_t d_type;
 120   uint16_t d_class;
 121   uint32_t d_ttl;
 122   uint16_t d_clen;
 123 } GCCPACKATTRIBUTE;
 124
 125 struct EDNS0Record
 126 {
 127         uint8_t extRCode, version;
 128         uint16_t Z;
 129 } GCCPACKATTRIBUTE;
 130
 131 static_assert(sizeof(EDNS0Record) == 4, "EDNS0Record size must be 4");
 132
 133 #if defined(__FreeBSD__) || defined(__APPLE__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__)
 134 #include <machine/endian.h>
 135 #elif __linux__ || __GNU__
 136 # include <endian.h>
 137
 138 #else  // with thanks to <arpa/nameser.h>
 139
 140 # define LITTLE_ENDIAN   1234    /* least-significant byte first (vax, pc) */
 141 # define BIG_ENDIAN      4321    /* most-significant byte first (IBM, net) */
 142 # define PDP_ENDIAN      3412    /* LSB first in word, MSW first in long (pdp) */
 143
 144 #if defined(vax) || defined(ns32000) || defined(sun386) || defined(i386) || \
 145         defined(__i386) || defined(__ia64) || defined(__amd64) || \
 146         defined(MIPSEL) || defined(_MIPSEL) || defined(BIT_ZERO_ON_RIGHT) || \
 147         defined(__alpha__) || defined(__alpha) || \
 148         (defined(__Lynx__) && defined(__x86__))
 149 # define BYTE_ORDER      LITTLE_ENDIAN
 150 #endif
 151
 152 #if defined(sel) || defined(pyr) || defined(mc68000) || defined(sparc) || \
 153     defined(__sparc) || \
 154     defined(is68k) || defined(tahoe) || defined(ibm032) || defined(ibm370) || \
 155     defined(MIPSEB) || defined(_MIPSEB) || defined(_IBMR2) || defined(DGUX) ||\
 156     defined(apollo) || defined(__convex__) || defined(_CRAY) || \
 157     defined(__hppa) || defined(__hp9000) || \
 158     defined(__hp9000s300) || defined(__hp9000s700) || \
 159     defined(__hp3000s900) || defined(MPE) || \
 160     defined(BIT_ZERO_ON_LEFT) || defined(m68k) || \
 161         (defined(__Lynx__) && \
 162         (defined(__68k__) || defined(__sparc__) || defined(__powerpc__)))
 163 # define BYTE_ORDER      BIG_ENDIAN
 164 #endif
 165
 166 #endif
 167
 168 struct dnsheader {
 169         unsigned        id :16;         /* query identification number */
 170 #if BYTE_ORDER == BIG_ENDIAN
 171                         /* fields in third byte */
 172         unsigned        qr: 1;          /* response flag */
 173         unsigned        opcode: 4;      /* purpose of message */
 174         unsigned        aa: 1;          /* authoritative answer */
 175         unsigned        tc: 1;          /* truncated message */
 176         unsigned        rd: 1;          /* recursion desired */
 177                         /* fields in fourth byte */
 178         unsigned        ra: 1;          /* recursion available */
 179         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
 180         unsigned        ad: 1;          /* authentic data from named */
 181         unsigned        cd: 1;          /* checking disabled by resolver */
 182         unsigned        rcode :4;       /* response code */
 183 #elif BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
 184                         /* fields in third byte */
 185         unsigned        rd :1;          /* recursion desired */
 186         unsigned        tc :1;          /* truncated message */
 187         unsigned        aa :1;          /* authoritative answer */
 188         unsigned        opcode :4;      /* purpose of message */
 189         unsigned        qr :1;          /* response flag */
 190                         /* fields in fourth byte */
 191         unsigned        rcode :4;       /* response code */
 192         unsigned        cd: 1;          /* checking disabled by resolver */
 193         unsigned        ad: 1;          /* authentic data from named */
 194         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
 195         unsigned        ra :1;          /* recursion available */
 196 #endif
 197                         /* remaining bytes */
 198         unsigned        qdcount :16;    /* number of question entries */
 199         unsigned        ancount :16;    /* number of answer entries */
 200         unsigned        nscount :16;    /* number of authority entries */
 201         unsigned        arcount :16;    /* number of resource entries */
 202 };
 203
 204 static_assert(sizeof(dnsheader) == 12, "dnsheader size must be 12");
 205
 206 inline uint16_t * getFlagsFromDNSHeader(struct dnsheader * dh)
 207 {
 208   return (uint16_t*) (((char *) dh) + sizeof(uint16_t));
 209 }
 210
 211 #define DNS_TYPE_SIZE (2)
 212 #define DNS_CLASS_SIZE (2)
 213 #define DNS_TTL_SIZE (4)
 214 #define DNS_RDLENGTH_SIZE (2)
 215 #define EDNS_EXTENDED_RCODE_SIZE (1)
 216 #define EDNS_VERSION_SIZE (1)
 217 #define EDNS_OPTION_CODE_SIZE (2)
 218 #define EDNS_OPTION_LENGTH_SIZE (2)
 219
 220 #if BYTE_ORDER == BIG_ENDIAN
 221 #define FLAGS_RD_OFFSET (8)
 222 #define FLAGS_CD_OFFSET (12)
 223 #elif BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
 224 #define FLAGS_RD_OFFSET (0)
 225 #define FLAGS_CD_OFFSET (12)
 226 #endif
 227
 228 #define L theL()
 229 extern time_t s_starttime;
 230
 231 uint32_t hashQuestion(const char* packet, uint16_t len, uint32_t init);
 232
 233 struct TSIGTriplet
 234 {
 235   DNSName name, algo;
 236   string secret;
 237 };
 238
 239 /** for use by DNSPacket, converts a SOAData class to a ascii line again */
 240 string serializeSOAData(const SOAData &data);
 241 string &attodot(string &str);  //!< for when you need to insert an email address in the SOA