iter_resptype.c File Reference

This file defines the response type. More...

#include "config.h"
#include "iterator/iter_resptype.h"
#include "iterator/iter_delegpt.h"
#include "iterator/iterator.h"
#include "services/cache/dns.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "sldns/rrdef.h"
#include "sldns/pkthdr.h"

Functions
enum response_type	response_type_from_cache (struct dns_msg *msg, struct query_info *request)
	Classifies a response message from cache based on the current request.
enum response_type	response_type_from_server (int rdset, struct dns_msg *msg, struct query_info *request, struct delegpt *dp, int *empty_nodata_found, int msg_lame_empty, int msg_lame_referral)
	Classifies a response message (from the wire) based on the current request.

Detailed Description

This file defines the response type.

DNS Responses can be classified as one of the response types.

Function Documentation

response_type_from_cache()

enum response_type response_type_from_cache	(	struct dns_msg *	msg,
		struct query_info *	request
	)

Classifies a response message from cache based on the current request.

Note that this routine assumes that THROWAWAY or LAME responses will not occur. Also, it will not detect REFERRAL type messages, since those are (currently) automatically classified based on how they came from the cache (findDelegation() instead of lookup()).

Parameters

msg	the message from the cache.
request	the request that generated the response.

Returns

the response type (CNAME or ANSWER).

References reply_info::an_numrrsets, packed_rrset_key::dname, reply_info::flags, FLAGS_GET_RCODE, get_cname_target(), LDNS_RR_TYPE_ANY, LDNS_RR_TYPE_CNAME, query_info::qclass, query_info::qname, query_info::qname_len, query_info::qtype, query_dname_compare(), dns_msg::rep, RESPONSE_TYPE_ANSWER, RESPONSE_TYPE_CNAME, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrsets, and packed_rrset_key::type.

Referenced by processInitRequest().

response_type_from_server()

enum response_type response_type_from_server	(	int	rdset,
		struct dns_msg *	msg,
		struct query_info *	request,
		struct delegpt *	dp,
		int *	empty_nodata_found,
		int	msg_lame_empty,
		int	msg_lame_referral
	)

Classifies a response message (from the wire) based on the current request.

NOTE: currently this routine uses the AA bit in the response to help distinguish between some non-standard referrals and answers. It also relies somewhat on the originating zone to be accurate (for lameness detection, mostly).

Parameters

rdset	if RD bit was sent in query sent by unbound.
msg	the message from the cache.
request	the request that generated the response.
dp	The delegation point that was being queried when the response was returned.
empty_nodata_found	flag to keep track of empty nodata detection.
msg_lame_empty	The scrubber indicates that this empty message is lame, before it became empty.
msg_lame_referral	returned true if the reply has a referral before scrub.

Returns

the response type (CNAME or ANSWER).

References reply_info::an_numrrsets, reply_info::ar_numrrsets, BIT_AA, BIT_RA, BIT_TC, packed_rrset_key::dname, dname_strict_subdomain_c(), dname_subdomain_c(), EMPTY_NODATA_RETRY_COUNT, reply_info::flags, FLAGS_GET_RCODE, get_cname_target(), LDNS_RR_TYPE_ANY, LDNS_RR_TYPE_CNAME, LDNS_RR_TYPE_NS, LDNS_RR_TYPE_SOA, delegpt::name, reply_info::ns_numrrsets, query_info::qclass, query_info::qname, query_info::qname_len, query_info::qtype, query_dname_compare(), dns_msg::rep, RESPONSE_TYPE_ANSWER, RESPONSE_TYPE_CNAME, RESPONSE_TYPE_LAME, RESPONSE_TYPE_REC_LAME, RESPONSE_TYPE_REFERRAL, RESPONSE_TYPE_THROWAWAY, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrsets, and packed_rrset_key::type.

Referenced by processPrimeResponse(), and processQueryResponse().