4 * DNS packet definitions
6 * a Net::DNS like library for C
8 * (c) NLnet Labs, 2005-2006
10 * See the file LICENSE for the license
16 * Contains the definition of ldns_pkt and its parts, as well
17 * as functions to manipulate those.
24 #define LDNS_MAX_PACKETLEN 65535
26 /* allow flags to be given to mk_query */
27 #define LDNS_QR 1 /* QueRy - query flag */
28 #define LDNS_AA 2 /* Authoritative Answer - server flag */
29 #define LDNS_TC 4 /* TrunCated - server flag */
30 #define LDNS_RD 8 /* Recursion Desired - query flag */
31 #define LDNS_CD 16 /* Checking Disabled - query flag */
32 #define LDNS_RA 32 /* Recursion Available - server flag */
33 #define LDNS_AD 64 /* Authenticated Data - server flag */
35 #include <ldns/error.h>
36 #include <ldns/common.h>
44 /* opcodes for pkt's */
45 enum ldns_enum_pkt_opcode {
46 LDNS_PACKET_QUERY = 0,
47 LDNS_PACKET_IQUERY = 1,
48 LDNS_PACKET_STATUS = 2, /* there is no 3?? DNS is weird */
49 LDNS_PACKET_NOTIFY = 4,
50 LDNS_PACKET_UPDATE = 5
52 typedef enum ldns_enum_pkt_opcode ldns_pkt_opcode;
55 enum ldns_enum_pkt_rcode {
56 LDNS_RCODE_NOERROR = 0,
57 LDNS_RCODE_FORMERR = 1,
58 LDNS_RCODE_SERVFAIL = 2,
59 LDNS_RCODE_NXDOMAIN = 3,
60 LDNS_RCODE_NOTIMPL = 4,
61 LDNS_RCODE_REFUSED = 5,
62 LDNS_RCODE_YXDOMAIN = 6,
63 LDNS_RCODE_YXRRSET = 7,
64 LDNS_RCODE_NXRRSET = 8,
65 LDNS_RCODE_NOTAUTH = 9,
66 LDNS_RCODE_NOTZONE = 10
68 typedef enum ldns_enum_pkt_rcode ldns_pkt_rcode;
71 * Header of a dns packet
73 * Contains the information about the packet itself, as specified in RFC1035
75 4.1.1. Header section format
77 The header contains the following fields:
80 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
81 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
83 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
84 |QR| Opcode |AA|TC|RD|RA| Z | RCODE |
85 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
87 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
89 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
91 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
93 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
97 ID A 16 bit identifier assigned by the program that
98 generates any kind of query. This identifier is copied
99 the corresponding reply and can be used by the requester
100 to match up replies to outstanding queries.
102 QR A one bit field that specifies whether this message is a
103 query (0), or a response (1).
105 OPCODE A four bit field that specifies kind of query in this
106 message. This value is set by the originator of a query
107 and copied into the response. The values are:
109 0 a standard query (QUERY)
111 1 an inverse query (IQUERY)
113 2 a server status request (STATUS)
115 3-15 reserved for future use
117 AA Authoritative Answer - this bit is valid in responses,
118 and specifies that the responding name server is an
119 authority for the domain name in question section.
121 Note that the contents of the answer section may have
122 multiple owner names because of aliases. The AA bit
124 corresponds to the name which matches the query name, or
125 the first owner name in the answer section.
127 TC TrunCation - specifies that this message was truncated
128 due to length greater than that permitted on the
129 transmission channel.
131 RD Recursion Desired - this bit may be set in a query and
132 is copied into the response. If RD is set, it directs
133 the name server to pursue the query recursively.
134 Recursive query support is optional.
136 RA Recursion Available - this be is set or cleared in a
137 response, and denotes whether recursive query support is
138 available in the name server.
140 Z Reserved for future use. Must be zero in all queries
143 RCODE Response code - this 4 bit field is set as part of
144 responses. The values have the following
149 1 Format error - The name server was
150 unable to interpret the query.
152 2 Server failure - The name server was
153 unable to process this query due to a
154 problem with the name server.
156 3 Name Error - Meaningful only for
157 responses from an authoritative name
158 server, this code signifies that the
159 domain name referenced in the query does
162 4 Not Implemented - The name server does
163 not support the requested kind of query.
165 5 Refused - The name server refuses to
166 perform the specified operation for
167 policy reasons. For example, a name
168 server may not wish to provide the
169 information to the particular requester,
170 or a name server may not wish to perform
171 a particular operation (e.g., zone
173 transfer) for particular data.
175 6-15 Reserved for future use.
177 QDCOUNT an unsigned 16 bit integer specifying the number of
178 entries in the question section.
180 ANCOUNT an unsigned 16 bit integer specifying the number of
181 resource records in the answer section.
183 NSCOUNT an unsigned 16 bit integer specifying the number of name
184 server resource records in the authority records
187 ARCOUNT an unsigned 16 bit integer specifying the number of
188 resource records in the additional records section.
192 struct ldns_struct_hdr
194 /** Id of a packet */
196 /** Query bit (0=query, 1=answer) */
198 /** Authoritative answer */
200 /** Packet truncated */
202 /** Recursion desired */
204 /** Checking disabled */
206 /** Recursion available */
208 /** Authentic data */
211 ldns_pkt_opcode _opcode; /* XXX 8 bits? */
223 typedef struct ldns_struct_hdr ldns_hdr;
228 * This structure contains a complete DNS packet (either a query or an answer)
230 * It is the complete representation of what you actually send to a
231 * nameserver, and what it sends back (assuming you are the client here).
233 struct ldns_struct_pkt
235 /** Header section */
237 /* extra items needed in a packet */
238 /** The size of the wire format of the packet in octets */
239 ldns_rdf *_answerfrom;
240 /** Timestamp of the time the packet was sent or created */
241 struct timeval timestamp;
242 /** The duration of the query this packet is an answer to */
244 /** The size of the wire format of the packet in octets */
246 /** Optional tsig rr */
248 /** EDNS0 available buffer size, see RFC2671 */
249 uint16_t _edns_udp_size;
250 /** EDNS0 Extended rcode */
251 uint8_t _edns_extended_rcode;
253 uint8_t _edns_version;
254 /** Reserved EDNS data bits */
256 /** Arbitrary EDNS rdata */
257 ldns_rdf *_edns_data;
258 /** Question section */
259 ldns_rr_list *_question;
260 /** Answer section */
261 ldns_rr_list *_answer;
262 /** Authority section */
263 ldns_rr_list *_authority;
264 /** Additional section */
265 ldns_rr_list *_additional;
267 typedef struct ldns_struct_pkt ldns_pkt;
270 * The sections of a packet
272 enum ldns_enum_pkt_section {
273 LDNS_SECTION_QUESTION = 0,
274 LDNS_SECTION_ANSWER = 1,
275 LDNS_SECTION_AUTHORITY = 2,
276 LDNS_SECTION_ADDITIONAL = 3,
277 /** bogus section, if not interested */
278 LDNS_SECTION_ANY = 4,
279 /** used to get all non-question rrs from a packet */
280 LDNS_SECTION_ANY_NOQUESTION = 5
282 typedef enum ldns_enum_pkt_section ldns_pkt_section;
285 * The different types of packets
287 enum ldns_enum_pkt_type {
288 LDNS_PACKET_QUESTION,
289 LDNS_PACKET_REFERRAL,
291 LDNS_PACKET_NXDOMAIN,
295 typedef enum ldns_enum_pkt_type ldns_pkt_type;
303 * \param[in] p the packet
304 * \return the packet id
306 uint16_t ldns_pkt_id(const ldns_pkt *p);
308 * Read the packet's qr bit
309 * \param[in] p the packet
310 * \return value of the bit
312 bool ldns_pkt_qr(const ldns_pkt *p);
314 * Read the packet's aa bit
315 * \param[in] p the packet
316 * \return value of the bit
318 bool ldns_pkt_aa(const ldns_pkt *p);
320 * Read the packet's tc bit
321 * \param[in] p the packet
322 * \return value of the bit
324 bool ldns_pkt_tc(const ldns_pkt *p);
326 * Read the packet's rd bit
327 * \param[in] p the packet
328 * \return value of the bit
330 bool ldns_pkt_rd(const ldns_pkt *p);
332 * Read the packet's cd bit
333 * \param[in] p the packet
334 * \return value of the bit
336 bool ldns_pkt_cd(const ldns_pkt *p);
338 * Read the packet's ra bit
339 * \param[in] p the packet
340 * \return value of the bit
342 bool ldns_pkt_ra(const ldns_pkt *p);
344 * Read the packet's ad bit
345 * \param[in] p the packet
346 * \return value of the bit
348 bool ldns_pkt_ad(const ldns_pkt *p);
350 * Read the packet's code
351 * \param[in] p the packet
354 ldns_pkt_opcode ldns_pkt_get_opcode(const ldns_pkt *p);
356 * Return the packet's respons code
357 * \param[in] p the packet
358 * \return the respons code
360 ldns_pkt_rcode ldns_pkt_get_rcode(const ldns_pkt *p);
362 * Return the packet's qd count
363 * \param[in] p the packet
364 * \return the qd count
366 uint16_t ldns_pkt_qdcount(const ldns_pkt *p);
368 * Return the packet's an count
369 * \param[in] p the packet
370 * \return the an count
372 uint16_t ldns_pkt_ancount(const ldns_pkt *p);
374 * Return the packet's ns count
375 * \param[in] p the packet
376 * \return the ns count
378 uint16_t ldns_pkt_nscount(const ldns_pkt *p);
380 * Return the packet's ar count
381 * \param[in] p the packet
382 * \return the ar count
384 uint16_t ldns_pkt_arcount(const ldns_pkt *p);
387 * Return the packet's answerfrom
388 * \param[in] p packet
389 * \return the name of the server
391 ldns_rdf *ldns_pkt_answerfrom(const ldns_pkt *p);
394 * Return the packet's timestamp
395 * \param[in] p the packet
396 * \return the timestamp
398 struct timeval ldns_pkt_timestamp(const ldns_pkt *p);
400 * Return the packet's querytime
401 * \param[in] p the packet
402 * \return the querytime
404 uint32_t ldns_pkt_querytime(const ldns_pkt *p);
407 * Return the packet's size in bytes
408 * \param[in] p the packet
411 size_t ldns_pkt_size(const ldns_pkt *p);
414 * Return the number of RRs in the given section.
415 * Returns the sum of all RRs when LDNS_SECTION_ANY is given.
416 * Returns the sum of all non-question RRs when LDNS_SECTION_ANY_NOQUESTION
418 * \param[in] p the packet
419 * \param[in] s the section
420 * \return the number of RRs in the given section
422 uint16_t ldns_pkt_section_count(const ldns_pkt *p, ldns_pkt_section s);
425 * Return the packet's tsig pseudo rr's
426 * \param[in] p the packet
427 * \return the tsig rr
429 ldns_rr *ldns_pkt_tsig(const ldns_pkt *p);
432 * Return the packet's question section
433 * \param[in] p the packet
434 * \return the section
436 ldns_rr_list *ldns_pkt_question(const ldns_pkt *p);
438 * Return the packet's answer section
439 * \param[in] p the packet
440 * \return the section
442 ldns_rr_list *ldns_pkt_answer(const ldns_pkt *p);
444 * Return the packet's authority section
445 * \param[in] p the packet
446 * \return the section
448 ldns_rr_list *ldns_pkt_authority(const ldns_pkt *p);
450 * Return the packet's additional section
451 * \param[in] p the packet
452 * \return the section
454 ldns_rr_list *ldns_pkt_additional(const ldns_pkt *p);
456 * Return the packet's question, answer, authority and additional sections
457 * concatenated, in a new rr_list clone.
458 * \param[in] p the packet
461 ldns_rr_list *ldns_pkt_all(const ldns_pkt *p);
463 * Return the packet's answer, authority and additional sections concatenated,
464 * in a new rr_list clone. Like ldns_pkt_all but without the questions.
465 * \param[in] p the packet
466 * \return the rrs except the question rrs
468 ldns_rr_list *ldns_pkt_all_noquestion(const ldns_pkt *p);
471 * return all the rr_list's in the packet. Clone the lists, instead
472 * of returning pointers.
473 * \param[in] p the packet to look in
474 * \param[in] s what section(s) to return
475 * \return ldns_rr_list with the rr's or NULL if none were found
477 ldns_rr_list *ldns_pkt_get_section_clone(const ldns_pkt *p, ldns_pkt_section s);
480 * return all the rr with a specific name from a packet. Optionally
481 * specify from which section in the packet
482 * \param[in] p the packet
483 * \param[in] r the name
484 * \param[in] s the packet's section
485 * \return a list with the rr's or NULL if none were found
487 ldns_rr_list *ldns_pkt_rr_list_by_name(ldns_pkt *p, ldns_rdf *r, ldns_pkt_section s);
489 * return all the rr with a specific type from a packet. Optionally
490 * specify from which section in the packet
491 * \param[in] p the packet
492 * \param[in] t the type
493 * \param[in] s the packet's section
494 * \return a list with the rr's or NULL if none were found
496 ldns_rr_list *ldns_pkt_rr_list_by_type(const ldns_pkt *p, ldns_rr_type t, ldns_pkt_section s);
498 * return all the rr with a specific type and type from a packet. Optionally
499 * specify from which section in the packet
500 * \param[in] packet the packet
501 * \param[in] ownername the name
502 * \param[in] type the type
503 * \param[in] sec the packet's section
504 * \return a list with the rr's or NULL if none were found
506 ldns_rr_list *ldns_pkt_rr_list_by_name_and_type(const ldns_pkt *packet, const ldns_rdf *ownername, ldns_rr_type type, ldns_pkt_section sec);
510 * check to see if an rr exist in the packet
511 * \param[in] pkt the packet to examine
512 * \param[in] sec in which section to look
513 * \param[in] rr the rr to look for
515 bool ldns_pkt_rr(ldns_pkt *pkt, ldns_pkt_section sec, ldns_rr *rr);
519 * sets the flags in a packet.
520 * \param[in] pkt the packet to operate on
521 * \param[in] flags ORed values: LDNS_QR| LDNS_AR for instance
522 * \return true on success otherwise false
524 bool ldns_pkt_set_flags(ldns_pkt *pkt, uint16_t flags);
527 * Set the packet's id
528 * \param[in] p the packet
529 * \param[in] id the id to set
531 void ldns_pkt_set_id(ldns_pkt *p, uint16_t id);
533 * Set the packet's id to a random value
534 * \param[in] p the packet
536 void ldns_pkt_set_random_id(ldns_pkt *p);
538 * Set the packet's qr bit
539 * \param[in] p the packet
540 * \param[in] b the value to set (boolean)
542 void ldns_pkt_set_qr(ldns_pkt *p, bool b);
544 * Set the packet's aa bit
545 * \param[in] p the packet
546 * \param[in] b the value to set (boolean)
548 void ldns_pkt_set_aa(ldns_pkt *p, bool b);
550 * Set the packet's tc bit
551 * \param[in] p the packet
552 * \param[in] b the value to set (boolean)
554 void ldns_pkt_set_tc(ldns_pkt *p, bool b);
556 * Set the packet's rd bit
557 * \param[in] p the packet
558 * \param[in] b the value to set (boolean)
560 void ldns_pkt_set_rd(ldns_pkt *p, bool b);
562 * Set the packet's cd bit
563 * \param[in] p the packet
564 * \param[in] b the value to set (boolean)
566 void ldns_pkt_set_cd(ldns_pkt *p, bool b);
568 * Set the packet's ra bit
569 * \param[in] p the packet
570 * \param[in] b the value to set (boolean)
572 void ldns_pkt_set_ra(ldns_pkt *p, bool b);
574 * Set the packet's ad bit
575 * \param[in] p the packet
576 * \param[in] b the value to set (boolean)
578 void ldns_pkt_set_ad(ldns_pkt *p, bool b);
581 * Set the packet's opcode
582 * \param[in] p the packet
583 * \param[in] c the opcode
585 void ldns_pkt_set_opcode(ldns_pkt *p, ldns_pkt_opcode c);
587 * Set the packet's respons code
588 * \param[in] p the packet
589 * \param[in] c the rcode
591 void ldns_pkt_set_rcode(ldns_pkt *p, uint8_t c);
593 * Set the packet's qd count
594 * \param[in] p the packet
595 * \param[in] c the count
597 void ldns_pkt_set_qdcount(ldns_pkt *p, uint16_t c);
599 * Set the packet's an count
600 * \param[in] p the packet
601 * \param[in] c the count
603 void ldns_pkt_set_ancount(ldns_pkt *p, uint16_t c);
605 * Set the packet's ns count
606 * \param[in] p the packet
607 * \param[in] c the count
609 void ldns_pkt_set_nscount(ldns_pkt *p, uint16_t c);
611 * Set the packet's arcount
612 * \param[in] p the packet
613 * \param[in] c the count
615 void ldns_pkt_set_arcount(ldns_pkt *p, uint16_t c);
617 * Set the packet's answering server
618 * \param[in] p the packet
619 * \param[in] r the address
621 void ldns_pkt_set_answerfrom(ldns_pkt *p, ldns_rdf *r);
623 * Set the packet's query time
624 * \param[in] p the packet
625 * \param[in] t the querytime in msec
627 void ldns_pkt_set_querytime(ldns_pkt *p, uint32_t t);
629 * Set the packet's size
630 * \param[in] p the packet
631 * \param[in] s the size
633 void ldns_pkt_set_size(ldns_pkt *p, size_t s);
636 * Set the packet's timestamp
637 * \param[in] p the packet
638 * \param[in] timeval the timestamp
640 void ldns_pkt_set_timestamp(ldns_pkt *p, struct timeval timeval);
642 * Set a packet's section count to x
643 * \param[in] p the packet
644 * \param[in] s the section
645 * \param[in] x the section count
647 void ldns_pkt_set_section_count(ldns_pkt *p, ldns_pkt_section s, uint16_t x);
649 * Set the packet's tsig rr
650 * \param[in] p the packet
651 * \param[in] t the tsig rr
653 void ldns_pkt_set_tsig(ldns_pkt *p, ldns_rr *t);
656 * looks inside the packet to determine
657 * what kind of packet it is, AUTH, NXDOMAIN, REFERRAL, etc.
658 * \param[in] p the packet to examine
659 * \return the type of packet
661 ldns_pkt_type ldns_pkt_reply_type(ldns_pkt *p);
664 * return the packet's edns udp size
665 * \param[in] packet the packet
668 uint16_t ldns_pkt_edns_udp_size(const ldns_pkt *packet);
670 * return the packet's edns extended rcode
671 * \param[in] packet the packet
674 uint8_t ldns_pkt_edns_extended_rcode(const ldns_pkt *packet);
676 * return the packet's edns version
677 * \param[in] packet the packet
678 * \return the version
680 uint8_t ldns_pkt_edns_version(const ldns_pkt *packet);
682 * return the packet's edns z value
683 * \param[in] packet the packet
684 * \return the z value
686 uint16_t ldns_pkt_edns_z(const ldns_pkt *packet);
688 * return the packet's edns data
689 * \param[in] packet the packet
692 ldns_rdf *ldns_pkt_edns_data(const ldns_pkt *packet);
695 * return the packet's edns do bit
696 * \param[in] packet the packet
697 * \return the bit's value
699 bool ldns_pkt_edns_do(const ldns_pkt *packet);
701 * Set the packet's edns do bit
702 * \param[in] packet the packet
703 * \param[in] value the bit's new value
705 void ldns_pkt_set_edns_do(ldns_pkt *packet, bool value);
708 * returns true if this packet needs and EDNS rr to be sent.
709 * At the moment the only reason is an expected packet
710 * size larger than 512 bytes, but for instance dnssec would
711 * be a good reason too.
713 * \param[in] packet the packet to check
714 * \return true if packet needs edns rr
716 bool ldns_pkt_edns(const ldns_pkt *packet);
719 * Set the packet's edns udp size
720 * \param[in] packet the packet
721 * \param[in] s the size
723 void ldns_pkt_set_edns_udp_size(ldns_pkt *packet, uint16_t s);
725 * Set the packet's edns extended rcode
726 * \param[in] packet the packet
727 * \param[in] c the code
729 void ldns_pkt_set_edns_extended_rcode(ldns_pkt *packet, uint8_t c);
731 * Set the packet's edns version
732 * \param[in] packet the packet
733 * \param[in] v the version
735 void ldns_pkt_set_edns_version(ldns_pkt *packet, uint8_t v);
737 * Set the packet's edns z value
738 * \param[in] packet the packet
739 * \param[in] z the value
741 void ldns_pkt_set_edns_z(ldns_pkt *packet, uint16_t z);
743 * Set the packet's edns data
744 * \param[in] packet the packet
745 * \param[in] data the data
747 void ldns_pkt_set_edns_data(ldns_pkt *packet, ldns_rdf *data);
750 * allocates and initializes a ldns_pkt structure.
751 * \return pointer to the new packet
753 ldns_pkt *ldns_pkt_new(void);
756 * frees the packet structure and all data that it contains.
757 * \param[in] packet The packet structure to free
760 void ldns_pkt_free(ldns_pkt *packet);
763 * creates a query packet for the given name, type, class.
764 * \param[out] p the packet to be returned
765 * \param[in] rr_name the name to query for (as string)
766 * \param[in] rr_type the type to query for
767 * \param[in] rr_class the class to query for
768 * \param[in] flags packet flags
769 * \return LDNS_STATUS_OK or a ldns_status mesg with the error
771 ldns_status ldns_pkt_query_new_frm_str(ldns_pkt **p, const char *rr_name, ldns_rr_type rr_type, ldns_rr_class rr_class , uint16_t flags);
774 * creates an IXFR request packet for the given name, class.
775 * adds the SOA record to the authority section.
776 * \param[out] p the packet to be returned
777 * \param[in] rr_name the name to query for (as string)
778 * \param[in] rr_class the class to query for
779 * \param[in] flags packet flags
780 * \param[in] soa soa record to be added to the authority section
781 * \return LDNS_STATUS_OK or a ldns_status mesg with the error
783 ldns_status ldns_pkt_ixfr_request_new_frm_str(ldns_pkt **p, const char *rr_name, ldns_rr_class rr_class, uint16_t flags, ldns_rr* soa);
786 * creates a packet with a query in it for the given name, type and class.
787 * \param[in] rr_name the name to query for
788 * \param[in] rr_type the type to query for
789 * \param[in] rr_class the class to query for
790 * \param[in] flags packet flags
791 * \return ldns_pkt* a pointer to the new pkt
793 ldns_pkt *ldns_pkt_query_new(ldns_rdf *rr_name, ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags);
796 * creates an IXFR request packet for the given name, type and class.
797 * adds the SOA record to the authority section.
798 * \param[in] rr_name the name to query for
799 * \param[in] rr_class the class to query for
800 * \param[in] flags packet flags
801 * \param[in] soa soa record to be added to the authority section
802 * \return ldns_pkt* a pointer to the new pkt
804 ldns_pkt *ldns_pkt_ixfr_request_new(ldns_rdf *rr_name, ldns_rr_class rr_class, uint16_t flags, ldns_rr* soa);
807 * clones the given packet, creating a fully allocated copy
809 * \param[in] pkt the packet to clone
810 * \return ldns_pkt* pointer to the new packet
812 ldns_pkt *ldns_pkt_clone(ldns_pkt *pkt);
815 * directly set the additional section
816 * \param[in] p packet to operate on
817 * \param[in] rr rrlist to set
819 void ldns_pkt_set_additional(ldns_pkt *p, ldns_rr_list *rr);
822 * directly set the answer section
823 * \param[in] p packet to operate on
824 * \param[in] rr rrlist to set
826 void ldns_pkt_set_answer(ldns_pkt *p, ldns_rr_list *rr);
829 * directly set the question section
830 * \param[in] p packet to operate on
831 * \param[in] rr rrlist to set
833 void ldns_pkt_set_question(ldns_pkt *p, ldns_rr_list *rr);
836 * directly set the auhority section
837 * \param[in] p packet to operate on
838 * \param[in] rr rrlist to set
840 void ldns_pkt_set_authority(ldns_pkt *p, ldns_rr_list *rr);
843 * push an rr on a packet
844 * \param[in] packet packet to operate on
845 * \param[in] section where to put it
846 * \param[in] rr rr to push
847 * \return a boolean which is true when the rr was added
849 bool ldns_pkt_push_rr(ldns_pkt *packet, ldns_pkt_section section, ldns_rr *rr);
852 * push an rr on a packet, provided the RR is not there.
853 * \param[in] pkt packet to operate on
854 * \param[in] sec where to put it
855 * \param[in] rr rr to push
856 * \return a boolean which is true when the rr was added
858 bool ldns_pkt_safe_push_rr(ldns_pkt *pkt, ldns_pkt_section sec, ldns_rr *rr);
861 * push a rr_list on a packet
862 * \param[in] packet packet to operate on
863 * \param[in] section where to put it
864 * \param[in] list the rr_list to push
865 * \return a boolean which is true when the rr was added
867 bool ldns_pkt_push_rr_list(ldns_pkt *packet, ldns_pkt_section section, ldns_rr_list *list);
870 * push an rr_list to a packet, provided the RRs are not already there.
871 * \param[in] pkt packet to operate on
872 * \param[in] sec where to put it
873 * \param[in] list the rr_list to push
874 * \return a boolean which is true when the rr was added
876 bool ldns_pkt_safe_push_rr_list(ldns_pkt *pkt, ldns_pkt_section sec, ldns_rr_list *list);
879 * check if a packet is empty
880 * \param[in] p packet
881 * \return true: empty, false: not empty
883 bool ldns_pkt_empty(ldns_pkt *p);
889 #endif /* LDNS_PACKET_H */