File: dnsbackend.hh

package info (click to toggle)
pdns-recursor 4.0.4-1+deb9u3~bpo8+1
  • links: PTS, VCS
  • area: main
  • in suites: jessie-backports
  • size: 5,484 kB
  • sloc: cpp: 36,380; sh: 11,771; makefile: 305; xml: 37
file content (435 lines) | stat: -rw-r--r-- 13,723 bytes parent folder | download | duplicates (3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#ifndef DNSBACKEND_HH
#define DNSBACKEND_HH

class DNSPacket;

#include "utility.hh"
#include <string>
#include <vector>
#include <map>
#include <sys/types.h>
#include "pdnsexception.hh"
#include <set>
#include <iostream>
#include <sys/socket.h>
#include <dirent.h>
#include "misc.hh"
#include "qtype.hh"
#include "dns.hh"
#include <vector>
#include "namespaces.hh"
#include "comment.hh"
#include "dnsname.hh"
#include "dnsrecords.hh"

class DNSBackend;  
struct DomainInfo
{
  DomainInfo() : last_check(0), backend(NULL), id(0), notified_serial(0), serial(0), kind(DomainInfo::Native) {}

  DNSName zone;
  time_t last_check;
  string account;
  vector<string> masters;
  DNSBackend *backend;

  uint32_t id;
  uint32_t notified_serial;

  uint32_t serial;
  enum DomainKind : uint8_t { Master, Slave, Native } kind;
  
  bool operator<(const DomainInfo& rhs) const
  {
    return zone < rhs.zone;
  }

  const char *getKindString() const
  {
    return DomainInfo::getKindString(kind);
  }

  static const char *getKindString(enum DomainKind kind)
  {
    const char *kinds[]={"Master", "Slave", "Native"};
    return kinds[kind];
  }

  static DomainKind stringToKind(const string& kind)
  {
    if(pdns_iequals(kind,"SLAVE"))
      return DomainInfo::Slave;
    else if(pdns_iequals(kind,"MASTER"))
      return DomainInfo::Master;
    else
      return DomainInfo::Native;
  }

};

struct TSIGKey {
   DNSName name;
   DNSName algorithm;
   std::string key;
};

class DNSPacket;

//! This virtual base class defines the interface for backends for the ahudns.
/** To create a backend, inherit from this class and implement functions for all virtual methods.
    Methods should not throw an exception if they are sure they did not find the requested data. However,
    if an error occurred which prevented them temporarily from performing a lockup, they should throw a DBException,
    which will cause the nameserver to send out a ServFail or take other evasive action. Probably only locking
    issues should lead to DBExceptions.

    More serious errors, which may indicate that the database connection is hosed, or a configuration error occurred, should
    lead to the throwing of an PDNSException. This exception will fall straight through the UeberBackend and the PacketHandler
    and be caught by the Distributor, which will delete your DNSBackend instance and spawn a new one.
*/
class DNSBackend
{
public:
  //! lookup() initiates a lookup. A lookup without results should not throw!
  virtual void lookup(const QType &qtype, const DNSName &qdomain, DNSPacket *pkt_p=0, int zoneId=-1)=0; 
  virtual bool get(DNSResourceRecord &)=0; //!< retrieves one DNSResource record, returns false if no more were available

  //! Initiates a list of the specified domain
  /** Once initiated, DNSResourceRecord objects can be retrieved using get(). Should return false
      if the backend does not consider itself responsible for the id passed.
      \param domain_id ID of which a list is requested
  */
  virtual bool list(const DNSName &target, int domain_id, bool include_disabled=false)=0;

  virtual ~DNSBackend(){};

  //! fills the soadata struct with the SOA details. Returns false if there is no SOA.
  virtual bool getSOA(const DNSName &name, SOAData &soadata, DNSPacket *p=0);

  //! Calculates a SOA serial for the zone and stores it in the third argument.
  virtual bool calculateSOASerial(const DNSName& domain, const SOAData& sd, time_t& serial);

  virtual bool replaceRRSet(uint32_t domain_id, const DNSName& qname, const QType& qt, const vector<DNSResourceRecord>& rrset)
  {
    return false;
  }

  virtual bool listSubZone(const DNSName &zone, int domain_id)
  {
    return false;
  }

  // the DNSSEC related (getDomainMetadata has broader uses too)
  bool isDnssecDomainMetadata (const string& name) {
    return (name == "PRESIGNED" || name == "NSEC3PARAM" || name == "NSEC3NARROW");
  }
  virtual bool getAllDomainMetadata(const DNSName& name, std::map<std::string, std::vector<std::string> >& meta) { return false; };
  virtual bool getDomainMetadata(const DNSName& name, const std::string& kind, std::vector<std::string>& meta) { return false; }
  virtual bool getDomainMetadataOne(const DNSName& name, const std::string& kind, std::string& value)
  {
    std::vector<std::string> meta;
    if (getDomainMetadata(name, kind, meta)) {
      if(!meta.empty()) {
        value = *meta.begin();
        return true;
      }
    }
    return false;
  }

  virtual bool setDomainMetadata(const DNSName& name, const std::string& kind, const std::vector<std::string>& meta) {return false;}
  virtual bool setDomainMetadataOne(const DNSName& name, const std::string& kind, const std::string& value)
  {
    const std::vector<std::string> meta(1, value);
    return setDomainMetadata(name, kind, meta);
  }


  virtual void getAllDomains(vector<DomainInfo> *domains, bool include_disabled=false) { }

  /** Determines if we are authoritative for a zone, and at what level */
  virtual bool getAuth(DNSPacket *p, SOAData *sd, const DNSName &target);

  struct KeyData {
    std::string content;
    unsigned int id;
    unsigned int flags;
    bool active;
  };

  virtual bool getDomainKeys(const DNSName& name, unsigned int kind, std::vector<KeyData>& keys) { return false;}
  virtual bool removeDomainKey(const DNSName& name, unsigned int id) { return false; }
  virtual int addDomainKey(const DNSName& name, const KeyData& key){ return -1; }
  virtual bool activateDomainKey(const DNSName& name, unsigned int id) { return false; }
  virtual bool deactivateDomainKey(const DNSName& name, unsigned int id) { return false; }

  virtual bool getTSIGKey(const DNSName& name, DNSName* algorithm, string* content) { return false; }
  virtual bool setTSIGKey(const DNSName& name, const DNSName& algorithm, const string& content) { return false; }
  virtual bool deleteTSIGKey(const DNSName& name) { return false; }
  virtual bool getTSIGKeys(std::vector< struct TSIGKey > &keys) { return false; }

  virtual bool getBeforeAndAfterNamesAbsolute(uint32_t id, const string& qname, DNSName& unhashed, string& before, string& after)
  {
    std::cerr<<"Default beforeAndAfterAbsolute called!"<<std::endl;
    abort();
    return false;
  }

  virtual bool getBeforeAndAfterNames(uint32_t id, const DNSName& zonename, const DNSName& qname, DNSName& before, DNSName& after);

  virtual bool updateDNSSECOrderNameAndAuth(uint32_t domain_id, const DNSName& zonename, const DNSName& qname, const DNSName& ordername, bool auth, const uint16_t qtype=QType::ANY)
  {
    return false;
  }

  virtual bool updateEmptyNonTerminals(uint32_t domain_id, const DNSName& zonename, set<DNSName>& insert, set<DNSName>& erase, bool remove)
  {
    return false;
  }

  virtual bool doesDNSSEC()
  {
    return false;
  }

  // end DNSSEC

  // comments support
  virtual bool listComments(uint32_t domain_id)
  {
    return false; // unsupported by this backend
  }

  virtual bool getComment(Comment& comment)
  {
    return false;
  }

  virtual void feedComment(const Comment& comment)
  {
  }

  virtual bool replaceComments(const uint32_t domain_id, const DNSName& qname, const QType& qt, const vector<Comment>& comments)
  {
    return false;
  }

  //! returns true if master ip is master for domain name.
  virtual bool isMaster(const DNSName &name, const string &ip)
  {
    return false;
  }
  
  //! starts the transaction for updating domain qname (FIXME: what is id?)
  virtual bool startTransaction(const DNSName &qname, int id=-1)
  {
    return false;
  }

  //! commits the transaction started by startTransaction
  virtual bool commitTransaction()
  {
    return false;
  }

  //! aborts the transaction started by strartTransaction, should leave state unaltered
  virtual bool abortTransaction()
  {
    return false;
  }

  virtual void reload()
  {
  }

  virtual void rediscover(string* status=0)
  {
  }

  //! feeds a record to a zone, needs a call to startTransaction first
  virtual bool feedRecord(const DNSResourceRecord &rr, string *ordername=0)
  {
    return false; // no problem!
  }
  virtual bool feedEnts(int domain_id, map<DNSName,bool> &nonterm)
  {
    return false;
  }
  virtual bool feedEnts3(int domain_id, const DNSName &domain, map<DNSName,bool> &nonterm, const NSEC3PARAMRecordContent& ns3prc, bool narrow)
  {
    return false;
  }

  //! if this returns true, DomainInfo di contains information about the domain
  virtual bool getDomainInfo(const DNSName &domain, DomainInfo &di)
  {
    return false;
  }
  //! slave capable backends should return a list of slaves that should be rechecked for staleness
  virtual void getUnfreshSlaveInfos(vector<DomainInfo>* domains)
  {
  }

  //! get a list of IP addresses that should also be notified for a domain
  virtual void alsoNotifies(const DNSName &domain, set<string> *ips)
  {
  }

  //! get list of domains that have been changed since their last notification to slaves
  virtual void getUpdatedMasters(vector<DomainInfo>* domains)
  {
  }
  
  //! Called by PowerDNS to inform a backend that a domain has been checked for freshness
  virtual void setFresh(uint32_t domain_id)
  {

  }
  //! Called by PowerDNS to inform a backend that the changes in the domain have been reported to slaves
  virtual void setNotified(uint32_t id, uint32_t serial)
  {
  }

  //! Called when the Master of a domain should be changed
  virtual bool setMaster(const DNSName &domain, const string &ip)
  {
    return false;
  }

  //! Called when the Kind of a domain should be changed (master -> native and similar)
  virtual bool setKind(const DNSName &domain, const DomainInfo::DomainKind kind)
  {
    return false;
  }

  //! Called when the Account of a domain should be changed
  virtual bool setAccount(const DNSName &domain, const string &account)
  {
    return false;
  }

  //! Can be called to seed the getArg() function with a prefix
  void setArgPrefix(const string &prefix);

  //! determine if ip is a supermaster or a domain
  virtual bool superMasterBackend(const string &ip, const DNSName &domain, const vector<DNSResourceRecord>&nsset, string *nameserver, string *account, DNSBackend **db)
  {
    return false;
  }

  //! called by PowerDNS to create a new domain
  virtual bool createDomain(const DNSName &domain)
  {
    return false;
  }

  //! called by PowerDNS to create a slave record for a superMaster
  virtual bool createSlaveDomain(const string &ip, const DNSName &domain, const string &nameserver, const string &account)
  {
    return false;
  }

  //! called to delete a domain, incl. all metadata, zone contents, etc.
  virtual bool deleteDomain(const DNSName &domain)
  {
    return false;
  }

  virtual string directBackendCmd(const string &query)
  {
    return "directBackendCmd not supported for this backend\n";
  }

  //! Search for records, returns true if search was done successfully.
  virtual bool searchRecords(const string &pattern, int maxResults, vector<DNSResourceRecord>& result)
  {
    return false;
  }

  //! Search for comments, returns true if search was done successfully.
  virtual bool searchComments(const string &pattern, int maxResults, vector<Comment>& result)
  {
    return false;
  }

  const string& getPrefix() { return d_prefix; };
protected:
  bool mustDo(const string &key);
  const string &getArg(const string &key);
  int getArgAsNum(const string &key);

private:
  string d_prefix;
};

class BackendFactory
{
public:
  BackendFactory(const string &name) : d_name(name) {}
  virtual ~BackendFactory(){}
  virtual DNSBackend *make(const string &suffix)=0;
  virtual DNSBackend *makeMetadataOnly(const string &suffix)
  {
    return this->make(suffix);
  }
  virtual void declareArguments(const string &suffix=""){}
  const string &getName() const;
  
protected:
  void declare(const string &suffix, const string &param, const string &explanation, const string &value);

private:
  const string d_name;
};

class BackendMakerClass
{
public:
  void report(BackendFactory *bf);
  void launch(const string &instr);
  vector<DNSBackend *>all(bool skipBIND=false);
  void load(const string &module);
  int numLauncheable();
  vector<string> getModules();

private:
  void load_all();
  typedef map<string,BackendFactory *>d_repository_t;
  d_repository_t d_repository;
  vector<pair<string,string> >d_instances;
};

extern BackendMakerClass &BackendMakers();

//! Exception that can be thrown by a DNSBackend to indicate a failure
class DBException : public PDNSException
{
public:
  DBException(const string &reason) : PDNSException(reason){}
};

/** helper function for both DNSPacket and addSOARecord() - converts a line into a struct, for easier parsing */
void fillSOAData(const string &content, SOAData &data);


#endif