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
  33 #undef BADSIG  // signal.h SIG_ERR
  34
  35 class DNSBackend;
  36 struct DNSRecord;
  37
  38 struct SOAData
  39 {
  40   SOAData() : ttl(0), serial(0), refresh(0), retry(0), expire(0), default_ttl(0), db(0), domain_id(-1), scopeMask(0) {};
  41
  42   DNSName qname;
  43   DNSName nameserver;
  44   DNSName hostmaster;
  45   uint32_t ttl;
  46   uint32_t serial;
  47   uint32_t refresh;
  48   uint32_t retry;
  49   uint32_t expire;
  50   uint32_t default_ttl;
  51   DNSBackend *db;
  52   int domain_id;
  53   uint8_t scopeMask;
  54 };
  55
  56 class RCode
  57 {
  58 public:
  59   enum rcodes_ { NoError=0, FormErr=1, ServFail=2, NXDomain=3, NotImp=4, Refused=5, YXDomain=6, YXRRSet=7, NXRRSet=8, NotAuth=9, NotZone=10};
  60   static std::string to_s(uint8_t rcode);
  61   static std::vector<std::string> rcodes_s;
  62 };
  63
  64 class ERCode
  65 {
  66 public:
  67   enum rcodes_ { BADVERS=16, BADSIG=16, BADKEY=17, BADTIME=18, BADMODE=19, BADNAME=20, BADALG=21, BADTRUNC=22, BADCOOKIE=23 };
  68   static std::string to_s(uint8_t rcode);
  69 };
  70
  71 class Opcode
  72 {
  73 public:
  74   enum { Query=0, IQuery=1, Status=2, Notify=4, Update=5 };
  75 };
  76
  77 // enum for policy decisions, used by both auth and recursor. Not all values supported everywhere.
  78 namespace PolicyDecision { enum returnTypes { PASS=-1, DROP=-2, TRUNCATE=-3 }; };
  79
  80 //! This class represents a resource record
  81 class DNSResourceRecord
  82 {
  83 public:
  84   DNSResourceRecord() : last_modified(0), ttl(0), signttl(0), domain_id(-1), qclass(1), scopeMask(0), auth(1), disabled(0) {};
  85   ~DNSResourceRecord(){};
  86   static DNSResourceRecord fromWire(const DNSRecord& d);
  87
  88   enum Place : uint8_t {QUESTION=0, ANSWER=1, AUTHORITY=2, ADDITIONAL=3}; //!< Type describing the positioning within, say, a DNSPacket
  89
  90   void setContent(const string& content);
  91   string getZoneRepresentation(bool noDot=false) const;
  92
  93   // data
  94   DNSName qname; //!< the name of this record, for example: www.powerdns.com
  95   DNSName wildcardname;
  96   string content; //!< what this record points to. Example: 10.1.2.3
  97
  98   // Aligned on 8-byte boundries on systems where time_t is 8 bytes and int
  99   // is 4 bytes, aka modern linux on x86_64
 100   time_t last_modified; //!< For autocalculating SOA serial numbers - the backend needs to fill this in
 101
 102   uint32_t ttl; //!< Time To Live of this record
 103   uint32_t signttl; //!< If non-zero, use this TTL as original TTL in the RRSIG
 104
 105   int domain_id; //!< If a backend implements this, the domain_id of the zone this record is in
 106   QType qtype; //!< qtype of this record, ie A, CNAME, MX etc
 107   uint16_t qclass; //!< class of this record
 108
 109   uint8_t scopeMask;
 110   bool auth;
 111   bool disabled;
 112
 113   bool operator==(const DNSResourceRecord& rhs);
 114
 115   bool operator<(const DNSResourceRecord &b) const
 116   {
 117     if(qname < b.qname)
 118       return true;
 119     if(qname == b.qname)
 120       return(content < b.content);
 121     return false;
 122   }
 123 };
 124
 125 #define GCCPACKATTRIBUTE __attribute__((packed))
 126
 127 struct dnsrecordheader
 128 {
 129   uint16_t d_type;
 130   uint16_t d_class;
 131   uint32_t d_ttl;
 132   uint16_t d_clen;
 133 } GCCPACKATTRIBUTE;
 134
 135 struct EDNS0Record
 136 {
 137         uint8_t extRCode, version;
 138         uint16_t Z;
 139 } GCCPACKATTRIBUTE;
 140
 141 static_assert(sizeof(EDNS0Record) == 4, "EDNS0Record size must be 4");
 142
 143 #if defined(__FreeBSD__) || defined(__APPLE__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__FreeBSD_kernel__) || defined(__NetBSD__)
 144 #include <machine/endian.h>
 145 #elif __linux__ || __GNU__
 146 # include <endian.h>
 147
 148 #else  // with thanks to <arpa/nameser.h>
 149
 150 # define LITTLE_ENDIAN   1234    /* least-significant byte first (vax, pc) */
 151 # define BIG_ENDIAN      4321    /* most-significant byte first (IBM, net) */
 152 # define PDP_ENDIAN      3412    /* LSB first in word, MSW first in long (pdp) */
 153
 154 #if defined(vax) || defined(ns32000) || defined(sun386) || defined(i386) || \
 155         defined(__i386) || defined(__ia64) || defined(__amd64) || \
 156         defined(MIPSEL) || defined(_MIPSEL) || defined(BIT_ZERO_ON_RIGHT) || \
 157         defined(__alpha__) || defined(__alpha) || \
 158         (defined(__Lynx__) && defined(__x86__))
 159 # define BYTE_ORDER      LITTLE_ENDIAN
 160 #endif
 161
 162 #if defined(sel) || defined(pyr) || defined(mc68000) || defined(sparc) || \
 163     defined(__sparc) || \
 164     defined(is68k) || defined(tahoe) || defined(ibm032) || defined(ibm370) || \
 165     defined(MIPSEB) || defined(_MIPSEB) || defined(_IBMR2) || defined(DGUX) ||\
 166     defined(apollo) || defined(__convex__) || defined(_CRAY) || \
 167     defined(__hppa) || defined(__hp9000) || \
 168     defined(__hp9000s300) || defined(__hp9000s700) || \
 169     defined(__hp3000s900) || defined(MPE) || \
 170     defined(BIT_ZERO_ON_LEFT) || defined(m68k) || \
 171         (defined(__Lynx__) && \
 172         (defined(__68k__) || defined(__sparc__) || defined(__powerpc__)))
 173 # define BYTE_ORDER      BIG_ENDIAN
 174 #endif
 175
 176 #endif
 177
 178 struct dnsheader {
 179         unsigned        id :16;         /* query identification number */
 180 #if BYTE_ORDER == BIG_ENDIAN
 181                         /* fields in third byte */
 182         unsigned        qr: 1;          /* response flag */
 183         unsigned        opcode: 4;      /* purpose of message */
 184         unsigned        aa: 1;          /* authoritative answer */
 185         unsigned        tc: 1;          /* truncated message */
 186         unsigned        rd: 1;          /* recursion desired */
 187                         /* fields in fourth byte */
 188         unsigned        ra: 1;          /* recursion available */
 189         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
 190         unsigned        ad: 1;          /* authentic data from named */
 191         unsigned        cd: 1;          /* checking disabled by resolver */
 192         unsigned        rcode :4;       /* response code */
 193 #elif BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
 194                         /* fields in third byte */
 195         unsigned        rd :1;          /* recursion desired */
 196         unsigned        tc :1;          /* truncated message */
 197         unsigned        aa :1;          /* authoritative answer */
 198         unsigned        opcode :4;      /* purpose of message */
 199         unsigned        qr :1;          /* response flag */
 200                         /* fields in fourth byte */
 201         unsigned        rcode :4;       /* response code */
 202         unsigned        cd: 1;          /* checking disabled by resolver */
 203         unsigned        ad: 1;          /* authentic data from named */
 204         unsigned        unused :1;      /* unused bits (MBZ as of 4.9.3a3) */
 205         unsigned        ra :1;          /* recursion available */
 206 #endif
 207                         /* remaining bytes */
 208         unsigned        qdcount :16;    /* number of question entries */
 209         unsigned        ancount :16;    /* number of answer entries */
 210         unsigned        nscount :16;    /* number of authority entries */
 211         unsigned        arcount :16;    /* number of resource entries */
 212 };
 213
 214 static_assert(sizeof(dnsheader) == 12, "dnsheader size must be 12");
 215
 216 inline uint16_t * getFlagsFromDNSHeader(struct dnsheader * dh)
 217 {
 218   return (uint16_t*) (((char *) dh) + sizeof(uint16_t));
 219 }
 220
 221 #define DNS_TYPE_SIZE (2)
 222 #define DNS_CLASS_SIZE (2)
 223 #define DNS_TTL_SIZE (4)
 224 #define DNS_RDLENGTH_SIZE (2)
 225 #define EDNS_EXTENDED_RCODE_SIZE (1)
 226 #define EDNS_VERSION_SIZE (1)
 227 #define EDNS_OPTION_CODE_SIZE (2)
 228 #define EDNS_OPTION_LENGTH_SIZE (2)
 229
 230 #if BYTE_ORDER == BIG_ENDIAN
 231 #define FLAGS_RD_OFFSET (8)
 232 #define FLAGS_CD_OFFSET (12)
 233 #elif BYTE_ORDER == LITTLE_ENDIAN || BYTE_ORDER == PDP_ENDIAN
 234 #define FLAGS_RD_OFFSET (0)
 235 #define FLAGS_CD_OFFSET (12)
 236 #endif
 237
 238 extern time_t s_starttime;
 239
 240 uint32_t hashQuestion(const char* packet, uint16_t len, uint32_t init);
 241
 242 struct TSIGTriplet
 243 {
 244   DNSName name, algo;
 245   string secret;
 246 };
 247
 248 string &attodot(string &str);  //!< for when you need to insert an email address in the SOA