resolver.h
Go to the documentation of this file.
1 /*
2  * resolver.h
3  *
4  * DNS Resolver definitions
5  *
6  * a Net::DNS like library for C
7  *
8  * (c) NLnet Labs, 2005-2006
9  *
10  * See the file LICENSE for the license
11  */
12 
20 #ifndef LDNS_RESOLVER_H
21 #define LDNS_RESOLVER_H
22 
23 #include <ldns/error.h>
24 #include <ldns/common.h>
25 #include <ldns/rr.h>
26 #include <ldns/tsig.h>
27 #include <ldns/rdata.h>
28 #include <ldns/packet.h>
29 #include <sys/time.h>
30 
31 #ifdef __cplusplus
32 extern "C" {
33 #endif
34 
36 #define LDNS_RESOLV_CONF "/etc/resolv.conf"
37 
38 #define LDNS_RESOLV_HOSTS "/etc/hosts"
39 
40 #define LDNS_RESOLV_KEYWORD -1
41 #define LDNS_RESOLV_DEFDOMAIN 0
42 #define LDNS_RESOLV_NAMESERVER 1
43 #define LDNS_RESOLV_SEARCH 2
44 #define LDNS_RESOLV_SORTLIST 3
45 #define LDNS_RESOLV_OPTIONS 4
46 #define LDNS_RESOLV_ANCHOR 5
47 #define LDNS_RESOLV_KEYWORDS 6
48 
49 #define LDNS_RESOLV_INETANY 0
50 #define LDNS_RESOLV_INET 1
51 #define LDNS_RESOLV_INET6 2
52 
53 #define LDNS_RESOLV_RTT_INF 0 /* infinity */
54 #define LDNS_RESOLV_RTT_MIN 1 /* reachable */
55 
60 {
62  uint16_t _port;
63 
67  size_t _nameserver_count; /* how many do we have */
68 
70  size_t *_rtt;
71 
73  bool _recursive;
74 
76  bool _debug;
77 
80 
83 
86 
88  uint8_t _retry;
90  uint8_t _retrans;
92  bool _fallback;
93 
95  bool _dnssec;
97  bool _dnssec_cd;
101  bool _usevc;
103  bool _igntc;
105  uint8_t _ip6;
107  bool _defnames;
109  bool _dnsrch;
111  struct timeval _timeout;
113  bool _fail;
115  bool _random;
117  int _socket;
122  /* when axfring we get complete packets from the server
123  but we want to give the caller 1 rr at a time, so
124  keep the current pkt */
128  uint16_t _axfr_i;
129  /* EDNS0 available buffer size */
130  uint16_t _edns_udp_size;
131 
132  /* Optional tsig key for signing queries,
133  outgoing messages are signed if and only if both are set
134  */
141 };
143 
144 /* prototypes */
145 /* read access functions */
146 
152 uint16_t ldns_resolver_port(const ldns_resolver *r);
153 
160 
166 bool ldns_resolver_debug(const ldns_resolver *r);
167 
173 uint8_t ldns_resolver_retry(const ldns_resolver *r);
174 
180 uint8_t ldns_resolver_retrans(const ldns_resolver *r);
181 
188 
194 uint8_t ldns_resolver_ip6(const ldns_resolver *r);
195 
201 uint16_t ldns_resolver_edns_udp_size(const ldns_resolver *r);
207 bool ldns_resolver_usevc(const ldns_resolver *r);
213 bool ldns_resolver_fail(const ldns_resolver *r);
225 bool ldns_resolver_dnsrch(const ldns_resolver *r);
231 bool ldns_resolver_dnssec(const ldns_resolver *r);
249 bool ldns_resolver_igntc(const ldns_resolver *r);
255 bool ldns_resolver_random(const ldns_resolver *r);
273 struct timeval ldns_resolver_timeout(const ldns_resolver *r);
292 size_t * ldns_resolver_rtt(const ldns_resolver *r);
299 size_t ldns_resolver_nameserver_rtt(const ldns_resolver *r, size_t pos);
324 
331 
332 /* write access function */
338 void ldns_resolver_set_port(ldns_resolver *r, uint16_t p);
339 
346 
352 void ldns_resolver_set_debug(ldns_resolver *r, bool b);
353 
359 
365 
372 
379 
387 
393 void ldns_resolver_set_timeout(ldns_resolver *r, struct timeval timeout);
394 
401 
408 
414 void ldns_resolver_set_usevc(ldns_resolver *r, bool b);
415 
421 void ldns_resolver_set_dnsrch(ldns_resolver *r, bool b);
422 
428 void ldns_resolver_set_dnssec(ldns_resolver *r, bool b);
429 
442 
450 
456 void ldns_resolver_set_retrans(ldns_resolver *r, uint8_t re);
457 
464 void ldns_resolver_set_fallback(ldns_resolver *r, bool fallback);
465 
471 void ldns_resolver_set_retry(ldns_resolver *r, uint8_t re);
472 
478 void ldns_resolver_set_ip6(ldns_resolver *r, uint8_t i);
479 
485 void ldns_resolver_set_fail(ldns_resolver *r, bool b);
486 
492 void ldns_resolver_set_igntc(ldns_resolver *r, bool b);
493 
500 
506 void ldns_resolver_set_tsig_keyname(ldns_resolver *r, char *tsig_keyname);
507 
513 void ldns_resolver_set_tsig_algorithm(ldns_resolver *r, char *tsig_algorithm);
514 
520 void ldns_resolver_set_tsig_keydata(ldns_resolver *r, char *tsig_keydata);
521 
528 void ldns_resolver_set_rtt(ldns_resolver *r, size_t *rtt);
529 
537 void ldns_resolver_set_nameserver_rtt(ldns_resolver *r, size_t pos, size_t value);
538 
544 void ldns_resolver_set_random(ldns_resolver *r, bool b);
545 
554 
563 
571 
584 ldns_pkt* ldns_resolver_search(const ldns_resolver *r, const ldns_rdf *rdf, ldns_rr_type t, ldns_rr_class c, uint16_t flags);
585 
598 
610 ldns_status ldns_resolver_send(ldns_pkt **answer, ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags);
611 
619 
631 ldns_pkt* ldns_resolver_query(const ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags);
632 
633 
639 
648 
657 ldns_status ldns_resolver_new_frm_fp_l(ldns_resolver **r, FILE *fp, int *line_nr);
658 
667 ldns_status ldns_resolver_new_frm_file(ldns_resolver **r, const char *filename);
668 
674 
680 
690 
696 bool ldns_axfr_complete(const ldns_resolver *resolver);
697 
705 
711 
719 bool ldns_resolver_trusted_key(const ldns_resolver *r, ldns_rr_list * keys, ldns_rr_list * trusted_keys);
720 
721 #ifdef __cplusplus
722 }
723 #endif
724 
725 #endif /* LDNS_RESOLVER_H */
uint8_t ldns_resolver_ip6(const ldns_resolver *r)
Does the resolver use ip6 or ip4.
Definition: resolver.c:54
void ldns_resolver_free(ldns_resolver *res)
Frees the allocated space for this resolver.
Definition: resolver.c:906
void ldns_resolver_set_domain(ldns_resolver *r, ldns_rdf *d)
Set the resolver&#39;s default domain.
Definition: resolver.c:533
bool ldns_resolver_dnsrch(const ldns_resolver *r)
Does the resolver apply search list.
Definition: resolver.c:72
char * ldns_resolver_tsig_algorithm(const ldns_resolver *r)
Return the tsig algorithm as used by the nameserver.
Definition: resolver.c:207
uint8_t ldns_resolver_retry(const ldns_resolver *r)
Get the number of retries.
Definition: resolver.c:36
ldns_status ldns_resolver_prepare_query_pkt(ldns_pkt **query_pkt, ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags)
Form a query packet from a resolver and name/type/class combo.
Definition: resolver.c:1124
ldns_rr_list * _dnssec_anchors
Optional trust anchors for complete DNSSEC validation.
Definition: resolver.h:99
DNS stub resolver structure.
Definition: resolver.h:59
Defines ldns_rdf and functions to manipulate those.
signed char _fail
Only try the first nameserver, and return with an error directly if it fails.
Definition: resolver.h:113
uint16_t _port
Port to send queries to.
Definition: resolver.h:62
enum ldns_enum_rr_class ldns_rr_class
Definition: rr.h:64
ldns_pkt * ldns_resolver_query(const ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags)
Send a query to a nameserver.
Definition: resolver.c:990
size_t ldns_resolver_searchlist_count(const ldns_resolver *r)
Return the resolver&#39;s searchlist count.
Definition: resolver.c:225
List or Set of Resource Records.
Definition: rr.h:306
void ldns_resolver_set_rtt(ldns_resolver *r, size_t *rtt)
Set round trip time for all nameservers.
Definition: resolver.c:488
size_t _searchlist_count
Number of entries in the searchlist array.
Definition: resolver.h:85
uint8_t _retrans
Time to wait before retrying.
Definition: resolver.h:90
void ldns_resolver_deep_free(ldns_resolver *res)
Frees the allocated space for this resolver and all it&#39;s data.
Definition: resolver.c:912
signed char _dnssec
Whether to do DNSSEC.
Definition: resolver.h:95
bool ldns_resolver_dnssec(const ldns_resolver *r)
Does the resolver do DNSSEC.
Definition: resolver.c:114
ldns_status ldns_resolver_push_nameserver_rr_list(ldns_resolver *r, ldns_rr_list *rrlist)
Push a new nameserver rr_list to the resolver.
Definition: resolver.c:339
void ldns_resolver_set_nameserver_rtt(ldns_resolver *r, size_t pos, size_t value)
Set round trip time for a specific nameserver.
Definition: resolver.c:494
void ldns_resolver_set_tsig_keyname(ldns_resolver *r, char *tsig_keyname)
Set the tsig key name.
Definition: resolver.c:568
void ldns_resolver_set_nameservers(ldns_resolver *r, ldns_rdf **n)
Set the resolver&#39;s nameserver count directly by using an rdf list.
Definition: resolver.c:476
void ldns_resolver_push_searchlist(ldns_resolver *r, ldns_rdf *d)
Push a new rd to the resolver&#39;s searchlist.
Definition: resolver.c:546
Defines functions for TSIG usage.
uint16_t _edns_udp_size
Definition: resolver.h:130
void ldns_resolver_set_tsig_algorithm(ldns_resolver *r, char *tsig_algorithm)
Set the tsig algorithm.
Definition: resolver.c:575
size_t * _rtt
Round trip time; 0 -&gt; infinity.
Definition: resolver.h:70
void ldns_resolver_set_timeout(ldns_resolver *r, struct timeval timeout)
Set the resolver&#39;s socket time out when talking to remote hosts.
Definition: resolver.c:539
Contains the definition of ldns_rr and functions to manipulate those.
uint16_t ldns_resolver_port(const ldns_resolver *r)
Get the port the resolver should use.
Definition: resolver.c:24
ldns_rdf ** ldns_resolver_searchlist(const ldns_resolver *r)
What is the searchlist as used by the resolver.
Definition: resolver.c:96
ldns_status ldns_resolver_push_dnssec_anchor(ldns_resolver *r, ldns_rr *rr)
Push a new trust anchor to the resolver.
Definition: resolver.c:391
ldns_rr_list * ldns_resolver_dnssec_anchors(const ldns_resolver *r)
Get the resolver&#39;s DNSSEC anchors.
Definition: resolver.c:126
bool ldns_resolver_dnssec_cd(const ldns_resolver *r)
Does the resolver set the CD bit.
Definition: resolver.c:120
ldns_pkt * ldns_axfr_last_pkt(const ldns_resolver *res)
Returns a pointer to the last ldns_pkt that was sent by the server in the AXFR transfer uasable for i...
Definition: resolver.c:1340
bool ldns_resolver_igntc(const ldns_resolver *r)
Does the resolver ignore the TC bit (truncated)
Definition: resolver.c:159
void ldns_resolver_set_igntc(ldns_resolver *r, bool i)
Definition: resolver.c:410
signed char _usevc
Whether to use tcp or udp (tcp if the value is true)
Definition: resolver.h:101
bool ldns_axfr_complete(const ldns_resolver *res)
Returns true if the axfr transfer has completed (i.e.
Definition: resolver.c:1333
size_t ldns_resolver_nameserver_rtt(const ldns_resolver *r, size_t pos)
Return the used round trip time for a specific nameserver.
Definition: resolver.c:177
Resource Record.
Definition: rr.h:278
char * _tsig_algorithm
TSIG signing algorithm.
Definition: resolver.h:140
void ldns_resolver_set_dnssec(ldns_resolver *r, bool d)
Definition: resolver.c:373
bool ldns_resolver_defnames(const ldns_resolver *r)
Does the resolver apply default domain name.
Definition: resolver.c:84
bool ldns_resolver_fallback(const ldns_resolver *r)
Get the truncation fallback status.
Definition: resolver.c:48
size_t _nameserver_count
Number of nameservers in _nameservers.
Definition: resolver.h:67
Defines error numbers and functions to translate those to a readable string.
uint8_t _retry
Number of times to retry before giving up.
Definition: resolver.h:88
void ldns_resolver_set_recursive(ldns_resolver *r, bool re)
Definition: resolver.c:367
signed char _debug
Print debug information.
Definition: resolver.h:76
void ldns_resolver_set_defnames(ldns_resolver *r, bool d)
Definition: resolver.c:482
ldns_rr * ldns_axfr_next(ldns_resolver *resolver)
Get the next stream of RRs in a AXFR.
Definition: resolver.c:1240
bool ldns_resolver_trusted_key(const ldns_resolver *r, ldns_rr_list *keys, ldns_rr_list *trusted_keys)
Returns true if at least one of the provided keys is a trust anchor.
Definition: resolver.c:132
void ldns_resolver_nameservers_randomize(ldns_resolver *r)
Randomize the nameserver list in the resolver.
Definition: resolver.c:1347
void ldns_resolver_set_nameserver_count(ldns_resolver *r, size_t c)
Set the resolver&#39;s nameserver count directly.
Definition: resolver.c:446
void ldns_resolver_set_fallback(ldns_resolver *r, bool fallback)
Definition: resolver.c:470
bool ldns_resolver_usevc(const ldns_resolver *r)
Does the resolver use tcp or udp.
Definition: resolver.c:165
ldns_pkt * ldns_resolver_search(const ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags)
Send the query for using the resolver and take the search list into account The search algorithm is a...
Definition: resolver.c:957
size_t ldns_resolver_nameserver_count(const ldns_resolver *r)
How many nameserver are configured in the resolver.
Definition: resolver.c:108
ldns_status ldns_resolver_send(ldns_pkt **answer, ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags)
Send the query for name as-is.
Definition: resolver.c:1173
int _axfr_soa_count
Count the number of LDNS_RR_TYPE_SOA RRs we have seen so far (the second one signifies the end of the...
Definition: resolver.h:121
uint16_t ldns_resolver_edns_udp_size(const ldns_resolver *r)
Get the resolver&#39;s udp size.
Definition: resolver.c:30
void ldns_resolver_incr_nameserver_count(ldns_resolver *r)
Incremental the resolver&#39;s nameserver count.
Definition: resolver.c:511
void ldns_resolver_set_random(ldns_resolver *r, bool b)
Definition: resolver.c:589
ldns_pkt * _cur_axfr_pkt
Packet currently handled when doing part of an AXFR.
Definition: resolver.h:126
struct timeval _timeout
Timeout for socket connections.
Definition: resolver.h:111
ldns_rdf ** _nameservers
Array of nameservers to query (IP addresses or dnames)
Definition: resolver.h:65
dsa q
Definition: keys.c:693
void ldns_resolver_set_fail(ldns_resolver *r, bool f)
Definition: resolver.c:434
uint16_t _axfr_i
Counter for within the AXFR packets.
Definition: resolver.h:128
ldns_resolver * ldns_resolver_new(void)
Create a new resolver structure.
Definition: resolver.c:596
bool ldns_resolver_debug(const ldns_resolver *r)
Get the debug status of the resolver.
Definition: resolver.c:66
signed char _recursive
Wether or not to be recursive.
Definition: resolver.h:73
signed char _defnames
If true append the default domain.
Definition: resolver.h:107
ldns_status ldns_resolver_push_nameserver_rr(ldns_resolver *r, ldns_rr *rr)
Push a new nameserver to the resolver.
Definition: resolver.c:323
DNS packet.
Definition: packet.h:233
void ldns_resolver_set_port(ldns_resolver *r, uint16_t p)
Set the port the resolver should use.
Definition: resolver.c:232
char * _tsig_keyname
Name of the key to use with TSIG, if _tsig_keyname and _tsig_keydata both contain values...
Definition: resolver.h:136
char * ldns_resolver_tsig_keydata(const ldns_resolver *r)
Return the tsig keydata as used by the nameserver.
Definition: resolver.c:213
bool ldns_resolver_random(const ldns_resolver *r)
Does the resolver randomize the nameserver before usage.
Definition: resolver.c:219
ldns_rdf * _domain
Default domain to add to non fully qualified domain names.
Definition: resolver.h:79
enum ldns_enum_status ldns_status
Definition: error.h:122
ldns_status ldns_resolver_new_frm_file(ldns_resolver **res, const char *filename)
Configure a resolver by means of a resolv.conf file The file may be NULL in which case there will be ...
Definition: resolver.c:875
ldns_status ldns_resolver_new_frm_fp_l(ldns_resolver **res, FILE *fp, int *line_nr)
Create a resolver structure from a file like /etc/resolv.conf.
Definition: resolver.c:659
uint8_t ldns_resolver_retrans(const ldns_resolver *r)
Get the retransmit interval.
Definition: resolver.c:42
signed char _igntc
Whether to ignore the tc bit.
Definition: resolver.h:103
ldns_rdf * ldns_resolver_pop_nameserver(ldns_resolver *r)
pop the last nameserver from the resolver.
Definition: resolver.c:238
void ldns_resolver_set_debug(ldns_resolver *r, bool d)
Definition: resolver.c:422
size_t * ldns_resolver_rtt(const ldns_resolver *r)
Return the used round trip times for the nameservers.
Definition: resolver.c:171
void ldns_resolver_set_usevc(ldns_resolver *r, bool vc)
Definition: resolver.c:416
bool ldns_resolver_fail(const ldns_resolver *r)
Does the resolver only try the first nameserver.
Definition: resolver.c:78
ldns_rdf ** _searchlist
Searchlist array, add the names in this array if a query cannot be found.
Definition: resolver.h:82
void ldns_resolver_set_edns_udp_size(ldns_resolver *r, uint16_t s)
Set maximum udp size.
Definition: resolver.c:361
signed char _dnssec_cd
Whether to set the CD bit on DNSSEC requests.
Definition: resolver.h:97
signed char _random
Randomly choose a nameserver.
Definition: resolver.h:115
ldns_status ldns_resolver_push_nameserver(ldns_resolver *r, ldns_rdf *n)
Push a new nameserver to the resolver.
Definition: resolver.c:276
ldns_rdf ** ldns_resolver_nameservers(const ldns_resolver *r)
Return the configured nameserver ip address.
Definition: resolver.c:102
ldns_status ldns_resolver_send_pkt(ldns_pkt **answer, ldns_resolver *r, ldns_pkt *query_pkt)
Send the given packet to a nameserver.
Definition: resolver.c:1068
char * ldns_resolver_tsig_keyname(const ldns_resolver *r)
Return the tsig keyname as used by the nameserver.
Definition: resolver.c:201
Contains the definition of ldns_pkt and its parts, as well as functions to manipulate those...
Resource record data field.
Definition: rdata.h:138
uint8_t _ip6
Whether to use ip6, 0-&gt;does not matter, 1 is IPv4, 2 is IPv6.
Definition: resolver.h:105
Common definitions for LDNS.
void ldns_resolver_set_retry(ldns_resolver *r, uint8_t retry)
Set the resolver retry interval (in seconds)
Definition: resolver.c:458
void ldns_resolver_set_dnssec_anchors(ldns_resolver *r, ldns_rr_list *l)
Set the resolver&#39;s DNSSEC anchor list directly.
Definition: resolver.c:385
enum ldns_enum_rr_type ldns_rr_type
Definition: rr.h:215
void ldns_resolver_set_retrans(ldns_resolver *r, uint8_t retrans)
Set the resolver retrans timeout (in seconds)
Definition: resolver.c:464
signed char _dnsrch
If true apply the search list.
Definition: resolver.h:109
bool ldns_resolver_recursive(const ldns_resolver *r)
Is the resolver set to recurse.
Definition: resolver.c:60
void ldns_resolver_set_ip6(ldns_resolver *r, uint8_t ip6)
Whether the resolver uses ip6.
Definition: resolver.c:428
void ldns_resolver_set_dnssec_cd(ldns_resolver *r, bool d)
Definition: resolver.c:379
ldns_status ldns_resolver_new_frm_fp(ldns_resolver **res, FILE *fp)
Create a resolver structure from a file like /etc/resolv.conf.
Definition: resolver.c:653
int _socket
Keep some things to make AXFR possible.
Definition: resolver.h:117
void ldns_resolver_set_dnsrch(ldns_resolver *r, bool d)
Definition: resolver.c:452
void ldns_resolver_set_tsig_keydata(ldns_resolver *r, char *tsig_keydata)
Set the tsig key data.
Definition: resolver.c:582
char * _tsig_keydata
Secret key data to use with TSIG, if _tsig_keyname and _tsig_keydata both contain values...
Definition: resolver.h:138
dsa p
Definition: keys.c:683
void ldns_resolver_dec_nameserver_count(ldns_resolver *r)
Decrement the resolver&#39;s nameserver count.
Definition: resolver.c:520
ldns_rdf * ldns_resolver_domain(const ldns_resolver *r)
What is the default dname to add to relative queries.
Definition: resolver.c:90
i
Definition: keys.c:681
struct timeval ldns_resolver_timeout(const ldns_resolver *r)
What is the timeout on socket connections.
Definition: resolver.c:195
signed char _fallback
Use new fallback mechanism (try EDNS, then do TCP)
Definition: resolver.h:92