resolver.h
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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 
144 };
146 
147 /* prototypes */
148 /* read access functions */
149 
155 uint16_t ldns_resolver_port(const ldns_resolver *r);
156 
163 
170 
176 bool ldns_resolver_debug(const ldns_resolver *r);
177 
183 uint8_t ldns_resolver_retry(const ldns_resolver *r);
184 
190 uint8_t ldns_resolver_retrans(const ldns_resolver *r);
191 
198 
204 uint8_t ldns_resolver_ip6(const ldns_resolver *r);
205 
211 uint16_t ldns_resolver_edns_udp_size(const ldns_resolver *r);
217 bool ldns_resolver_usevc(const ldns_resolver *r);
223 bool ldns_resolver_fail(const ldns_resolver *r);
235 bool ldns_resolver_dnsrch(const ldns_resolver *r);
241 bool ldns_resolver_dnssec(const ldns_resolver *r);
259 bool ldns_resolver_igntc(const ldns_resolver *r);
265 bool ldns_resolver_random(const ldns_resolver *r);
283 struct timeval ldns_resolver_timeout(const ldns_resolver *r);
302 size_t * ldns_resolver_rtt(const ldns_resolver *r);
309 size_t ldns_resolver_nameserver_rtt(const ldns_resolver *r, size_t pos);
334 
341 
342 /* write access function */
348 void ldns_resolver_set_port(ldns_resolver *r, uint16_t p);
349 
356 
363 
369 void ldns_resolver_set_debug(ldns_resolver *r, bool b);
370 
376 
382 
389 
396 
404 
410 void ldns_resolver_set_timeout(ldns_resolver *r, struct timeval timeout);
411 
418 
425 
431 void ldns_resolver_set_usevc(ldns_resolver *r, bool b);
432 
438 void ldns_resolver_set_dnsrch(ldns_resolver *r, bool b);
439 
445 void ldns_resolver_set_dnssec(ldns_resolver *r, bool b);
446 
459 
467 
473 void ldns_resolver_set_retrans(ldns_resolver *r, uint8_t re);
474 
481 void ldns_resolver_set_fallback(ldns_resolver *r, bool fallback);
482 
489 void ldns_resolver_set_retry(ldns_resolver *r, uint8_t re);
490 
496 void ldns_resolver_set_ip6(ldns_resolver *r, uint8_t i);
497 
503 void ldns_resolver_set_fail(ldns_resolver *r, bool b);
504 
510 void ldns_resolver_set_igntc(ldns_resolver *r, bool b);
511 
518 
524 void ldns_resolver_set_tsig_keyname(ldns_resolver *r, char *tsig_keyname);
525 
531 void ldns_resolver_set_tsig_algorithm(ldns_resolver *r, char *tsig_algorithm);
532 
538 void ldns_resolver_set_tsig_keydata(ldns_resolver *r, char *tsig_keydata);
539 
546 void ldns_resolver_set_rtt(ldns_resolver *r, size_t *rtt);
547 
555 void ldns_resolver_set_nameserver_rtt(ldns_resolver *r, size_t pos, size_t value);
556 
562 void ldns_resolver_set_random(ldns_resolver *r, bool b);
563 
572 
581 
589 
602 ldns_pkt* ldns_resolver_search(const ldns_resolver *r, const ldns_rdf *rdf, ldns_rr_type t, ldns_rr_class c, uint16_t flags);
603 
604 
619 
632 
644 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);
645 
653 
667 
668 
682 ldns_pkt* ldns_resolver_query(const ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t flags);
683 
684 
690 
699 
708 ldns_status ldns_resolver_new_frm_fp_l(ldns_resolver **r, FILE *fp, int *line_nr);
709 
718 ldns_status ldns_resolver_new_frm_file(ldns_resolver **r, const char *filename);
719 
725 
731 
741 
747 bool ldns_axfr_complete(const ldns_resolver *resolver);
748 
756 
762 
770 bool ldns_resolver_trusted_key(const ldns_resolver *r, ldns_rr_list * keys, ldns_rr_list * trusted_keys);
771 
772 #ifdef __cplusplus
773 }
774 #endif
775 
776 #endif /* LDNS_RESOLVER_H */
ldns_status ldns_resolver_push_nameserver(ldns_resolver *r, ldns_rdf *n)
Push a new nameserver to the resolver.
Definition: resolver.c:288
ldns_status ldns_resolver_push_nameserver_rr(ldns_resolver *r, ldns_rr *rr)
Push a new nameserver to the resolver.
Definition: resolver.c:335
ldns_rr * ldns_axfr_next(ldns_resolver *resolver)
Get the next stream of RRs in a AXFR.
Definition: resolver.c:1274
signed char ldns_resolver_recursive(const ldns_resolver *r)
Is the resolver set to recurse.
Definition: resolver.c:66
void ldns_resolver_set_usevc(ldns_resolver *r, signed char b)
Whether the resolver uses a virtual circuit (TCP)
ldns_rdf ** ldns_resolver_searchlist(const ldns_resolver *r)
What is the searchlist as used by the resolver.
Definition: resolver.c:102
ldns_rr_list * ldns_resolver_dnssec_anchors(const ldns_resolver *r)
Get the resolver&#39;s DNSSEC anchors.
Definition: resolver.c:132
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:183
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_status ldns_resolver_prepare_query_pkt(ldns_pkt **q, ldns_resolver *r, const ldns_rdf *name, ldns_rr_type t, ldns_rr_class c, uint16_t f)
Form a query packet from a resolver and name/type/class combo.
Definition: resolver.c:1153
List or Set of Resource Records.
Definition: rr.h:327
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
ldns_rdf * ldns_resolver_source(const ldns_resolver *r)
Get the source address the resolver should use.
Definition: resolver.c:30
signed char _dnssec
Whether to do DNSSEC.
Definition: resolver.h:95
ldns_rdf ** ldns_resolver_nameservers(const ldns_resolver *r)
Return the configured nameserver ip address.
Definition: resolver.c:108
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:1097
struct timeval ldns_resolver_timeout(const ldns_resolver *r)
What is the timeout on socket connections.
Definition: resolver.c:201
ldns_status ldns_resolver_query_status(ldns_pkt **pkt, 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:1036
Defines functions for TSIG usage.
void ldns_resolver_nameservers_randomize(ldns_resolver *r)
Randomize the nameserver list in the resolver.
Definition: resolver.c:1405
void ldns_resolver_set_nameserver_count(ldns_resolver *r, size_t c)
Set the resolver&#39;s nameserver count directly.
Definition: resolver.c:458
uint16_t _edns_udp_size
Definition: resolver.h:130
ldns_status ldns_resolver_search_status(ldns_pkt **pkt, ldns_resolver *r, const ldns_rdf *rdf, 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:990
void ldns_resolver_set_dnsrch(ldns_resolver *r, signed char b)
Whether the resolver uses the searchlist.
void ldns_resolver_set_fail(ldns_resolver *r, signed char b)
Whether or not to fail after one failed query.
signed char ldns_resolver_igntc(const ldns_resolver *r)
Does the resolver ignore the TC bit (truncated)
Definition: resolver.c:165
size_t * _rtt
Round trip time; 0 -> infinity.
Definition: resolver.h:70
void ldns_resolver_incr_nameserver_count(ldns_resolver *r)
Incremental the resolver&#39;s nameserver count.
Definition: resolver.c:523
Contains the definition of ldns_rr and functions to manipulate those.
char * ldns_resolver_tsig_algorithm(const ldns_resolver *r)
Return the tsig algorithm as used by the nameserver.
Definition: resolver.c:213
void ldns_resolver_set_domain(ldns_resolver *r, ldns_rdf *rd)
Set the resolver&#39;s default domain.
Definition: resolver.c:545
ldns_rdf * ldns_resolver_pop_nameserver(ldns_resolver *r)
pop the last nameserver from the resolver.
Definition: resolver.c:250
signed char _usevc
Whether to use tcp or udp (tcp if the value is true)
Definition: resolver.h:101
Resource Record.
Definition: rr.h:299
void ldns_resolver_set_dnssec(ldns_resolver *r, signed char b)
Whether the resolver uses DNSSEC.
signed char ldns_resolver_fallback(const ldns_resolver *r)
Get the truncation fallback status.
Definition: resolver.c:54
char * _tsig_algorithm
TSIG signing algorithm.
Definition: resolver.h:140
ldns_resolver * ldns_resolver_new(void)
Create a new resolver structure.
Definition: resolver.c:608
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:1057
signed char ldns_resolver_random(const ldns_resolver *r)
Does the resolver randomize the nameserver before usage.
Definition: resolver.c:225
signed char ldns_resolver_fail(const ldns_resolver *r)
Does the resolver only try the first nameserver.
Definition: resolver.c:84
void ldns_resolver_dec_nameserver_count(ldns_resolver *r)
Decrement the resolver&#39;s nameserver count.
Definition: resolver.c:532
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.
char * ldns_resolver_tsig_keyname(const ldns_resolver *r)
Return the tsig keyname as used by the nameserver.
Definition: resolver.c:207
uint8_t _retry
Number of times to retry before giving up.
Definition: resolver.h:88
signed char 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:138
signed char _debug
Print debug information.
Definition: resolver.h:76
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:397
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_port(const ldns_resolver *r)
Get the port the resolver should use.
Definition: resolver.c:24
void ldns_resolver_set_tsig_keydata(ldns_resolver *r, char *tsig_keydata)
Set the tsig key data.
Definition: resolver.c:594
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
void ldns_resolver_set_edns_udp_size(ldns_resolver *r, uint16_t s)
Set maximum udp size.
Definition: resolver.c:373
signed char ldns_resolver_usevc(const ldns_resolver *r)
Does the resolver use tcp or udp.
Definition: resolver.c:171
ldns_status ldns_resolver_new_frm_file(ldns_resolver **r, 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:908
uint16_t _axfr_i
Counter for within the AXFR packets.
Definition: resolver.h:128
signed char _recursive
Wether or not to be recursive.
Definition: resolver.h:73
void ldns_resolver_set_igntc(ldns_resolver *r, signed char b)
Whether or not to ignore the TC bit.
signed char _defnames
If true append the default domain.
Definition: resolver.h:107
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:351
void ldns_resolver_set_retry(ldns_resolver *r, uint8_t re)
Set the number of times a resolver should retry a nameserver before the next one is tried...
Definition: resolver.c:470
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:506
uint8_t ldns_resolver_ip6(const ldns_resolver *r)
Does the resolver use ip6 or ip4.
Definition: resolver.c:60
void ldns_resolver_set_tsig_keyname(ldns_resolver *r, char *tsig_keyname)
Set the tsig key name.
Definition: resolver.c:580
DNS packet.
Definition: packet.h:233
void ldns_resolver_set_source(ldns_resolver *r, ldns_rdf *s)
Set the source rdf (address) the resolver should use.
Definition: resolver.c:244
char * _tsig_keyname
Name of the key to use with TSIG, if _tsig_keyname and _tsig_keydata both contain values...
Definition: resolver.h:136
void ldns_resolver_set_recursive(ldns_resolver *r, signed char b)
Set the resolver recursion.
void ldns_resolver_set_debug(ldns_resolver *r, signed char b)
Set the resolver debugging.
ldns_status ldns_resolver_new_frm_fp(ldns_resolver **r, FILE *fp)
Create a resolver structure from a file like /etc/resolv.conf.
Definition: resolver.c:666
uint8_t ldns_resolver_retry(const ldns_resolver *r)
Get the number of retries.
Definition: resolver.c:42
void ldns_resolver_set_tsig_algorithm(ldns_resolver *r, char *tsig_algorithm)
Set the tsig algorithm.
Definition: resolver.c:587
ldns_rdf * _domain
Default domain to add to non fully qualified domain names.
Definition: resolver.h:79
signed char ldns_resolver_debug(const ldns_resolver *r)
Get the debug status of the resolver.
Definition: resolver.c:72
enum ldns_enum_status ldns_status
Definition: error.h:131
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:551
size_t ldns_resolver_nameserver_count(const ldns_resolver *r)
How many nameserver are configured in the resolver.
Definition: resolver.c:114
void ldns_resolver_push_searchlist(ldns_resolver *r, ldns_rdf *rd)
Push a new rd to the resolver&#39;s searchlist.
Definition: resolver.c:558
signed char _igntc
Whether to ignore the tc bit.
Definition: resolver.h:103
size_t ldns_resolver_searchlist_count(const ldns_resolver *r)
Return the resolver&#39;s searchlist count.
Definition: resolver.c:231
void ldns_resolver_set_fallback(ldns_resolver *r, signed char fallback)
Set whether the resolvers truncation fallback mechanism is used when ldns_resolver_query() is called...
uint16_t ldns_resolver_edns_udp_size(const ldns_resolver *r)
Get the resolver&#39;s udp size.
Definition: resolver.c:36
signed char ldns_resolver_defnames(const ldns_resolver *r)
Does the resolver apply default domain name.
Definition: resolver.c:90
ldns_rdf ** _searchlist
Searchlist array, add the names in this array if a query cannot be found.
Definition: resolver.h:82
ldns_rdf * ldns_resolver_domain(const ldns_resolver *r)
What is the default dname to add to relative queries.
Definition: resolver.c:96
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
void ldns_resolver_set_defnames(ldns_resolver *r, signed char b)
Whether the resolver uses the name set with _set_domain.
ldns_rdf * _source
Source address to query from.
Definition: resolver.h:143
void ldns_resolver_free(ldns_resolver *res)
Frees the allocated space for this resolver.
Definition: resolver.c:939
void ldns_resolver_set_dnssec_cd(ldns_resolver *r, signed char b)
Whether the resolver uses the checking disable bit.
Contains the definition of ldns_pkt and its parts, as well as functions to manipulate those...
Resource record data field.
Definition: rdata.h:166
uint8_t _ip6
Whether to use ip6, 0->does not matter, 1 is IPv4, 2 is IPv6.
Definition: resolver.h:105
Common definitions for LDNS.
void ldns_resolver_set_retrans(ldns_resolver *r, uint8_t re)
Set the resolver retrans timeout (in seconds)
Definition: resolver.c:476
signed char ldns_resolver_dnsrch(const ldns_resolver *r)
Does the resolver apply search list.
Definition: resolver.c:78
signed char ldns_axfr_complete(const ldns_resolver *resolver)
Returns true if the axfr transfer has completed (i.e.
Definition: resolver.c:1391
enum ldns_enum_rr_type ldns_rr_type
Definition: rr.h:236
void ldns_resolver_set_port(ldns_resolver *r, uint16_t p)
Set the port the resolver should use.
Definition: resolver.c:238
signed char _dnsrch
If true apply the search list.
Definition: resolver.h:109
char * ldns_resolver_tsig_keydata(const ldns_resolver *r)
Return the tsig keydata as used by the nameserver.
Definition: resolver.c:219
void ldns_resolver_set_nameservers(ldns_resolver *r, ldns_rdf **rd)
Set the resolver&#39;s nameserver count directly by using an rdf list.
Definition: resolver.c:488
ldns_status ldns_resolver_push_dnssec_anchor(ldns_resolver *r, ldns_rr *rr)
Push a new trust anchor to the resolver.
Definition: resolver.c:403
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:1207
int _socket
Keep some things to make AXFR possible.
Definition: resolver.h:117
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:1398
void ldns_resolver_set_rtt(ldns_resolver *r, size_t *rtt)
Set round trip time for all nameservers.
Definition: resolver.c:500
void ldns_resolver_set_random(ldns_resolver *r, signed char b)
Should the nameserver list be randomized before each use.
signed char ldns_resolver_dnssec_cd(const ldns_resolver *r)
Does the resolver set the CD bit.
Definition: resolver.c:126
signed char ldns_resolver_dnssec(const ldns_resolver *r)
Does the resolver do DNSSEC.
Definition: resolver.c:120
void ldns_resolver_deep_free(ldns_resolver *res)
Frees the allocated space for this resolver and all it&#39;s data.
Definition: resolver.c:945
char * _tsig_keydata
Secret key data to use with TSIG, if _tsig_keyname and _tsig_keydata both contain values...
Definition: resolver.h:138
uint8_t ldns_resolver_retrans(const ldns_resolver *r)
Get the retransmit interval.
Definition: resolver.c:48
ldns_status ldns_resolver_new_frm_fp_l(ldns_resolver **r, FILE *fp, int *line_nr)
Create a resolver structure from a file like /etc/resolv.conf.
Definition: resolver.c:672
size_t * ldns_resolver_rtt(const ldns_resolver *r)
Return the used round trip times for the nameservers.
Definition: resolver.c:177
ldns_pkt * ldns_resolver_search(const ldns_resolver *r, const ldns_rdf *rdf, 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:1024
signed char _fallback
Use new fallback mechanism (try EDNS, then do TCP)
Definition: resolver.h:92
void ldns_resolver_set_ip6(ldns_resolver *r, uint8_t i)
Whether the resolver uses ip6.
Definition: resolver.c:440