iter_utils.c File Reference

#include "config.h"
#include "iterator/iter_utils.h"
#include "iterator/iterator.h"
#include "iterator/iter_hints.h"
#include "iterator/iter_fwd.h"
#include "iterator/iter_donotq.h"
#include "iterator/iter_delegpt.h"
#include "iterator/iter_priv.h"
#include "services/cache/infra.h"
#include "services/cache/dns.h"
#include "services/cache/rrset.h"
#include "util/net_help.h"
#include "util/module.h"
#include "util/log.h"
#include "util/config_file.h"
#include "util/regional.h"
#include "util/data/msgparse.h"
#include "util/data/dname.h"
#include "util/random.h"
#include "util/fptr_wlist.h"
#include "validator/val_anchor.h"
#include "validator/val_kcache.h"
#include "validator/val_kentry.h"
#include "validator/val_utils.h"
#include "validator/val_sigcrypt.h"
#include "sldns/sbuffer.h"
#include "sldns/str2wire.h"

Macros
#define	SUSPICION_RECENT_EXPIRY   86400
	time when nameserver glue is said to be 'recent'
#define	BLACKLIST_PENALTY   (USEFUL_SERVER_TOP_TIMEOUT*4)
	penalty to validation failed blacklisted IPs

Functions
static void	fetch_fill (struct iter_env *ie, const char *str)
	fillup fetch policy array
static int	read_fetch_policy (struct iter_env *ie, const char *str)
	Read config string that represents the target fetch policy.
static int	caps_white_apply_cfg (rbtree_type *ntree, struct config_file *cfg)
	apply config caps whitelist items to name tree
int	iter_apply_cfg (struct iter_env *iter_env, struct config_file *cfg)
	Process config options and set iterator module state. More...
static int	iter_filter_unsuitable (struct iter_env *iter_env, struct module_env *env, uint8_t *name, size_t namelen, uint16_t qtype, time_t now, struct delegpt_addr *a)
	filter out unsuitable targets More...
static int	iter_fill_rtt (struct iter_env *iter_env, struct module_env *env, uint8_t *name, size_t namelen, uint16_t qtype, time_t now, struct delegpt *dp, int *best_rtt, struct sock_list *blacklist, size_t *num_suitable_results)
	lookup RTT information, and also store fastest rtt (if any)
static int	rtt_compare (const void *x, const void *y)
	compare two rtts, return -1, 0 or 1
static int	nth_rtt (struct delegpt_addr *result_list, size_t num_results, size_t n)
	get RTT for the Nth fastest server
static int	iter_filter_order (struct iter_env *iter_env, struct module_env *env, uint8_t *name, size_t namelen, uint16_t qtype, time_t now, struct delegpt *dp, int *selected_rtt, int open_target, struct sock_list *blacklist, time_t prefetch)
	filter the address list, putting best targets at front, returns number of best targets (or 0, no suitable targets)
struct delegpt_addr *	iter_server_selection (struct iter_env *iter_env, struct module_env *env, struct delegpt *dp, uint8_t *name, size_t namelen, uint16_t qtype, int *dnssec_lame, int *chase_to_rd, int open_target, struct sock_list *blacklist, time_t prefetch)
	Select a valid, nice target to send query to. More...
struct dns_msg *	dns_alloc_msg (sldns_buffer *pkt, struct msg_parse *msg, struct regional *region)
	Allocate dns_msg from parsed msg, in regional. More...
struct dns_msg *	dns_copy_msg (struct dns_msg *from, struct regional *region)
	Copy a dns_msg to this regional. More...
void	iter_dns_store (struct module_env *env, struct query_info *msgqinf, struct reply_info *msgrep, int is_referral, time_t leeway, int pside, struct regional *region, uint16_t flags)
	Allocate a dns_msg with malloc/alloc structure and store in dns cache. More...
int	iter_ns_probability (struct ub_randstate *rnd, int n, int m)
	Select randomly with n/m probability. More...
static int	causes_cycle (struct module_qstate *qstate, uint8_t *name, size_t namelen, uint16_t t, uint16_t c)
	detect dependency cycle for query and target
void	iter_mark_cycle_targets (struct module_qstate *qstate, struct delegpt *dp)
	Mark targets that result in a dependency cycle as done, so they will not get selected as targets. More...
void	iter_mark_pside_cycle_targets (struct module_qstate *qstate, struct delegpt *dp)
	Mark targets that result in a dependency cycle as done, so they will not get selected as targets. More...
int	iter_dp_is_useless (struct query_info *qinfo, uint16_t qflags, struct delegpt *dp)
	See if delegation is useful or offers immediately no targets for further recursion. More...
int	iter_qname_indicates_dnssec (struct module_env *env, struct query_info *qinfo)
	See if qname has DNSSEC needs. More...
int	iter_indicates_dnssec (struct module_env *env, struct delegpt *dp, struct dns_msg *msg, uint16_t dclass)
	See if delegation is expected to have DNSSEC information (RRSIGs) in its answers, or not. More...
int	iter_msg_has_dnssec (struct dns_msg *msg)
	See if a message contains DNSSEC. More...
int	iter_msg_from_zone (struct dns_msg *msg, struct delegpt *dp, enum response_type type, uint16_t dclass)
	See if a message is known to be from a certain zone. More...
static int	rrset_equal (struct ub_packed_rrset_key *k1, struct ub_packed_rrset_key *k2)
	check equality of two rrsets More...
static int	rrset_canonical_sort_cmp (const void *x, const void *y)
	compare rrsets and sort canonically. More...
int	reply_equal (struct reply_info *p, struct reply_info *q, struct regional *region)
	Check if two replies are equal For fallback procedures. More...
void	caps_strip_reply (struct reply_info *rep)
	Remove unused bits from the reply if possible. More...
int	caps_failed_rcode (struct reply_info *rep)
	see if reply has a 'useful' rcode for capsforid comparison, so not SERVFAIL or REFUSED, and thus NOERROR or NXDOMAIN. More...
void	iter_store_parentside_rrset (struct module_env *env, struct ub_packed_rrset_key *rrset)
	Store parent-side rrset in separate rrset cache entries for later last-resort * lookups in case the child-side versions of this information fails. More...
static struct ub_packed_rrset_key *	reply_get_NS_rrset (struct reply_info *rep)
	fetch NS record from reply, if any
void	iter_store_parentside_NS (struct module_env *env, struct reply_info *rep)
	Store parent-side NS records from a referral message. More...
void	iter_store_parentside_neg (struct module_env *env, struct query_info *qinfo, struct reply_info *rep)
	Store parent-side negative element, the parentside rrset does not exist, creates an rrset with empty rdata in the rrset cache with PARENTSIDE flag. More...
int	iter_lookup_parent_NS_from_cache (struct module_env *env, struct delegpt *dp, struct regional *region, struct query_info *qinfo)
	Add parent NS record if that exists in the cache. More...
int	iter_lookup_parent_glue_from_cache (struct module_env *env, struct delegpt *dp, struct regional *region, struct query_info *qinfo)
	Add parent-side glue if that exists in the cache. More...
int	iter_get_next_root (struct iter_hints *hints, struct iter_forwards *fwd, uint16_t *c)
	Lookup next root-hint or root-forward entry. More...
void	iter_scrub_ds (struct dns_msg *msg, struct ub_packed_rrset_key *ns, uint8_t *z)
	Remove DS records that are inappropriate before they are cached. More...
void	iter_scrub_nxdomain (struct dns_msg *msg)
	Prepare an NXDOMAIN message to be used for a subdomain answer by removing all RRs from the ANSWER section. More...
void	iter_dec_attempts (struct delegpt *dp, int d)
	Remove query attempts from all available ips. More...
void	iter_merge_retry_counts (struct delegpt *dp, struct delegpt *old)
	Add retry counts from older delegpt to newer delegpt. More...
int	iter_ds_toolow (struct dns_msg *msg, struct delegpt *dp)
	See if a DS response (type ANSWER) is too low: a nodata answer with a SOA record in the authority section at-or-below the qchase.qname. More...
int	iter_dp_cangodown (struct query_info *qinfo, struct delegpt *dp)
	See if delegpt can go down a step to the qname or not. More...
int	iter_stub_fwd_no_cache (struct module_qstate *qstate, struct query_info *qinf)
	Lookup if no_cache is set in stub or fwd. More...

Detailed Description

This file contains functions to assist the iterator module. Configuration options. Forward zones.

Function Documentation

iter_apply_cfg()

int iter_apply_cfg	(	struct iter_env *	iter_env,
		struct config_file *	cfg
	)

Process config options and set iterator module state.

Sets default values if no config is found.

Parameters

iter_env	iterator module state.
cfg	config options.

Returns

0 on error.

References iter_env::caps_white, caps_white_apply_cfg(), config_file::caps_whitelist, config_file::do_ip4, config_file::do_ip6, iter_env::donotq, donotq_apply_cfg(), donotq_create(), log_err(), iter_env::max_dependency_depth, name_tree_compare(), iter_env::priv, priv_apply_cfg(), priv_create(), rbtree_create(), read_fetch_policy(), iter_env::supports_ipv4, iter_env::supports_ipv6, iter_env::target_fetch_policy, config_file::target_fetch_policy, VERB_QUERY, and verbose().

Referenced by iter_init().

iter_filter_unsuitable()

static int iter_filter_unsuitable ( struct iter_env *  iter_env, struct module_env *  env, uint8_t *  name, size_t  namelen, uint16_t  qtype, time_t  now, struct delegpt_addr *  a  )

static

filter out unsuitable targets

Parameters

iter_env	iterator environment with ipv6-support flag.
env	module environment with infra cache.
name	zone name
namelen	length of name
qtype	query type (host order).
now	current time
a	address in delegation point we are examining.

Returns

an integer that signals the target suitability. as follows: -1: The address should be omitted from the list. Because: o The address is bogus (DNSSEC validation failure). o Listed as donotquery o is ipv6 but no ipv6 support (in operating system). o is ipv4 but no ipv4 support (in operating system). o is lame Otherwise, an rtt in milliseconds. 0 .. USEFUL_SERVER_TOP_TIMEOUT-1 The roundtrip time timeout estimate. less than 2 minutes. Note that util/rtt.c has a MIN_TIMEOUT of 50 msec, thus values 0 .. 49 are not used, unless that is changed. USEFUL_SERVER_TOP_TIMEOUT This value exactly is given for unresponsive blacklisted. USEFUL_SERVER_TOP_TIMEOUT+1 For non-blacklisted servers: huge timeout, but has traffic. USEFUL_SERVER_TOP_TIMEOUT*1 .. parent-side lame servers get this penalty. A dispreferential server. (lame in delegpt). USEFUL_SERVER_TOP_TIMEOUT*2 .. dnsseclame servers get penalty USEFUL_SERVER_TOP_TIMEOUT*3 .. recursion lame servers get penalty UNKNOWN_SERVER_NICENESS If no information is known about the server, this is returned. 376 msec or so. +BLACKLIST_PENALTY (of USEFUL_TOP_TIMEOUT*4) for dnssec failed IPs.

When a final value is chosen that is dnsseclame ; dnsseclameness checking is turned off (so we do not discard the reply). When a final value is chosen that is recursionlame; RD bit is set on query. Because of the numbers this means recursionlame also have dnssec lameness checking turned off.

References delegpt_addr::addr, addr_is_ip6(), delegpt_addr::addrlen, delegpt_addr::bogus, delegpt_addr::dnsseclame, iter_env::donotq, donotq_lookup(), module_env::infra_cache, infra_get_lame_rtt(), delegpt_addr::lame, log_addr(), name_tree_node::name, iter_env::supports_ipv4, iter_env::supports_ipv6, UNKNOWN_SERVER_NICENESS, USEFUL_SERVER_TOP_TIMEOUT, VERB_ALGO, and verbose().

Referenced by iter_fill_rtt().

iter_server_selection()

struct delegpt_addr* iter_server_selection	(	struct iter_env *	iter_env,
		struct module_env *	env,
		struct delegpt *	dp,
		uint8_t *	name,
		size_t	namelen,
		uint16_t	qtype,
		int *	dnssec_lame,
		int *	chase_to_rd,
		int	open_target,
		struct sock_list *	blacklist,
		time_t	prefetch
	)

Select a valid, nice target to send query to.

Sorting and removing unsuitable targets is combined.

Parameters

iter_env	iterator module global state, with ip6 enabled and do-not-query-addresses.
env	environment with infra cache (lameness, rtt info).
dp	delegation point with result list.
name	zone name (for lameness check).
namelen	length of name.
qtype	query type that we want to send.
dnssec_lame	set to 1, if a known dnssec-lame server is selected these are not preferred, but are used as a last resort.
chase_to_rd	set to 1 if a known recursion lame server is selected these are not preferred, but are used as a last resort.
open_target	number of currently outstanding target queries. If we wait for these, perhaps more server addresses become available.
blacklist	the IP blacklist to use.
prefetch	if not 0, prefetch is in use for this query. This means the query can have different timing, because prefetch is not waited upon by the downstream client, and thus a good time to perform exploration of other targets.

Returns

best target or NULL if no target. if not null, that target is removed from the result list in the dp.

References delegpt_addr::attempts, BLACKLIST_PENALTY, iter_filter_order(), log_assert, delegpt_addr::next_result, module_env::now, OUTBOUND_MSG_RETRY, delegpt::result_list, module_env::rnd, ub_random_max(), USEFUL_SERVER_TOP_TIMEOUT, VERB_ALGO, and verbose().

dns_alloc_msg()

struct dns_msg* dns_alloc_msg	(	struct sldns_buffer *	pkt,
		struct msg_parse *	msg,
		struct regional *	regional
	)

Allocate dns_msg from parsed msg, in regional.

Parameters

pkt	packet.
msg	parsed message (cleaned and ready for regional allocation).
regional	regional to use for allocation.

Returns

newly allocated dns_msg, or NULL on memory error.

References log_err(), parse_create_msg(), dns_msg::qinfo, regional_alloc(), and dns_msg::rep.

dns_copy_msg()

struct dns_msg* dns_copy_msg	(	struct dns_msg *	from,
		struct regional *	regional
	)

Copy a dns_msg to this regional.

Parameters

from	dns message, also in regional.
regional	regional to use for allocation.

Returns

newly allocated dns_msg, or NULL on memory error.

References dns_msg::qinfo, query_info::qname, query_info::qname_len, regional_alloc(), regional_alloc_init(), dns_msg::rep, and reply_info_copy().

iter_dns_store()

void iter_dns_store	(	struct module_env *	env,
		struct query_info *	qinf,
		struct reply_info *	rep,
		int	is_referral,
		time_t	leeway,
		int	pside,
		struct regional *	region,
		uint16_t	flags
	)

Allocate a dns_msg with malloc/alloc structure and store in dns cache.

Parameters

env	environment, with alloc structure and dns cache.
qinf	query info, the query for which answer is stored.
rep	reply in dns_msg from dns_alloc_msg for example.
is_referral	If true, then the given message to be stored is a referral. The cache implementation may use this as a hint.
leeway	prefetch TTL leeway to expire old rrsets quicker.
pside	true if dp is parentside, thus message is 'fresh' and NS can be prefetch-updates.
region	to copy modified (cache is better) rrs back to.
flags	with BIT_CD for dns64 AAAA translated queries.

Returns

void, because we are not interested in alloc errors, the iterator and validator can operate on the results in their scratch space (the qstate.region) and are not dependent on the cache. It is useful to log the alloc failure (for the server operator), but the query resolution can continue without cache storage.

References dns_cache_store(), and log_err().

iter_ns_probability()

int iter_ns_probability	(	struct ub_randstate *	rnd,
		int	n,
		int	m
	)

Select randomly with n/m probability.

For shuffle NS records for address fetching.

Parameters

rnd	random table
n	probability.
m	divisor for probability.

Returns

true with n/m probability.

References ub_random_max().

Referenced by query_for_targets().

iter_mark_cycle_targets()

void iter_mark_cycle_targets	(	struct module_qstate *	qstate,
		struct delegpt *	dp
	)

Mark targets that result in a dependency cycle as done, so they will not get selected as targets.

Parameters

qstate	query state.
dp	delegpt to mark ns in.

References causes_cycle(), LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, log_nametypeclass(), delegpt_ns::name, delegpt_ns::namelen, delegpt_ns::next, delegpt::nslist, query_info::qclass, module_qstate::qinfo, delegpt_ns::resolved, and VERB_QUERY.

Referenced by query_for_targets().

iter_mark_pside_cycle_targets()

void iter_mark_pside_cycle_targets	(	struct module_qstate *	qstate,
		struct delegpt *	dp
	)

Mark targets that result in a dependency cycle as done, so they will not get selected as targets.

For the parent-side lookups.

Parameters

qstate	query state.
dp	delegpt to mark ns in.

References causes_cycle(), delegpt_ns::done_pside4, delegpt_ns::done_pside6, LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, log_nametypeclass(), delegpt_ns::name, delegpt_ns::namelen, delegpt_ns::next, delegpt::nslist, query_info::qclass, module_qstate::qinfo, and VERB_QUERY.

iter_dp_is_useless()

int iter_dp_is_useless	(	struct query_info *	qinfo,
		uint16_t	qflags,
		struct delegpt *	dp
	)

See if delegation is useful or offers immediately no targets for further recursion.

Parameters

qinfo	query name and type
qflags	query flags with RD flag
dp	delegpt to check.

Returns

true if dp is useless.

References BIT_RD, delegpt_find_ns(), dname_subdomain_c(), LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, delegpt::name, delegpt_ns::name, delegpt_ns::next, delegpt::nslist, query_info::qname, query_info::qname_len, query_info::qtype, delegpt_ns::resolved, delegpt::result_list, and delegpt::usable_list.

iter_qname_indicates_dnssec()

int iter_qname_indicates_dnssec	(	struct module_env *	env,
		struct query_info *	qinfo
	)

See if qname has DNSSEC needs.

This is true if there is a trust anchor above it. Whether there is an insecure delegation to the data is unknown.

Parameters

env	environment with anchors.
qinfo	query name and class.

Returns

true if trust anchor above qname, false if no anchor or insecure point above qname.

References module_env::anchors, anchors_lookup(), trust_anchor::lock, trust_anchor::numDNSKEY, trust_anchor::numDS, query_info::qclass, query_info::qname, and query_info::qname_len.

iter_indicates_dnssec()

int iter_indicates_dnssec	(	struct module_env *	env,
		struct delegpt *	dp,
		struct dns_msg *	msg,
		uint16_t	dclass
	)

See if delegation is expected to have DNSSEC information (RRSIGs) in its answers, or not.

Inspects delegation point (name), trust anchors, and delegation message (DS RRset) to determine this.

Parameters

env	module env with trust anchors.
dp	delegation point.
msg	delegation message, with DS if a secure referral.
dclass	class of query.

Returns

1 if dnssec is expected, 0 if not or insecure point above qname.

References anchor_find(), module_env::anchors, trust_anchor::dclass, module_env::key_cache, key_cache_obtain(), key_entry_isbad(), key_entry_isgood(), key_entry_isnull(), LDNS_RR_TYPE_DS, trust_anchor::lock, delegpt::name, key_entry_key::name, delegpt::namelabs, delegpt::namelen, module_env::now, trust_anchor::numDNSKEY, trust_anchor::numDS, query_dname_compare(), regional_free_all(), dns_msg::rep, reply_find_rrset_section_ns(), and module_env::scratch.

Referenced by generate_parentside_target_query(), prime_root(), and processInitRequest3().

iter_msg_has_dnssec()

int iter_msg_has_dnssec

(

struct dns_msg *

msg

)

See if a message contains DNSSEC.

This is examined by looking for RRSIGs. With DNSSEC a valid answer, nxdomain, nodata, referral or cname reply has RRSIGs in answer or auth sections, sigs on answer data, SOA, DS, or NSEC/NSEC3 records.

Parameters

msg	message to examine.

Returns

true if DNSSEC information was found.

References reply_info::an_numrrsets, reply_info::ns_numrrsets, dns_msg::rep, and reply_info::rrsets.

Referenced by processQueryResponse().

iter_msg_from_zone()

int iter_msg_from_zone	(	struct dns_msg *	msg,
		struct delegpt *	dp,
		enum response_type	type,
		uint16_t	dclass
	)

See if a message is known to be from a certain zone.

This looks for SOA or NS rrsets, for answers. For referrals, when one label is delegated, the zone is detected. Does not look at signatures.

Parameters

msg	the message to inspect.
dp	delegation point with zone name to look for.
type	type of message.
dclass	class of query.

Returns

true if message is certain to be from zone in dp->name. false if not sure (empty msg), or not from the zone.

References reply_info::an_numrrsets, packed_rrset_key::dname, dname_count_labels(), dname_strict_subdomain(), LDNS_RR_TYPE_NS, LDNS_RR_TYPE_SOA, log_assert, delegpt::name, delegpt::namelabs, delegpt::namelen, reply_info::ns_numrrsets, dns_msg::rep, reply_find_rrset_section_an(), reply_find_rrset_section_ns(), RESPONSE_TYPE_ANSWER, RESPONSE_TYPE_CNAME, RESPONSE_TYPE_REFERRAL, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrsets, and packed_rrset_key::type.

Referenced by processQueryResponse().

rrset_equal()

static int rrset_equal ( struct ub_packed_rrset_key *  k1, struct ub_packed_rrset_key *  k2  )

static

check equality of two rrsets

Parameters

k1	rrset
k2	rrset

Returns

true if equal

References packed_rrset_data::count, lruhash_entry::data, packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, packed_rrset_key::flags, query_dname_compare(), ub_packed_rrset_key::rk, packed_rrset_data::rr_data, packed_rrset_data::rr_len, packed_rrset_key::rrset_class, packed_rrset_data::rrsig_count, packed_rrset_data::security, packed_rrset_data::trust, and packed_rrset_key::type.

Referenced by reply_equal().

rrset_canonical_sort_cmp()

static int rrset_canonical_sort_cmp ( const void *  x, const void *  y  )

static

compare rrsets and sort canonically.

Compares rrset name, type, class. return 0 if equal, +1 if x > y, and -1 if x < y.

References packed_rrset_key::dname, dname_canonical_compare(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, and packed_rrset_key::type.

Referenced by reply_equal().

reply_equal()

int reply_equal	(	struct reply_info *	p,
		struct reply_info *	q,
		struct regional *	region
	)

Check if two replies are equal For fallback procedures.

Parameters

p	reply one. The reply has rrset data pointers in region. Does not check rrset-IDs
q	reply two
region	scratch buffer.

Returns

if one and two are equal.

References reply_info::an_numrrsets, reply_info::ar_numrrsets, reply_info::flags, log_assert, reply_info::ns_numrrsets, reply_info::qdcount, regional_alloc_init(), regional_free_all(), rrset_canonical_equal(), rrset_canonical_sort_cmp(), reply_info::rrset_count, rrset_equal(), reply_info::rrsets, and reply_info::security.

caps_strip_reply()

void caps_strip_reply

(

struct reply_info *

rep

)

Remove unused bits from the reply if possible.

So that caps-for-id (0x20) fallback is more likely to be successful. This removes like, the additional section, and NS record in the authority section if those records are gratuitous (not for a referral).

Parameters

rep	the reply to strip stuff out of.

References reply_info::an_numrrsets, reply_info::ar_numrrsets, BIT_AA, reply_info::flags, LDNS_RR_TYPE_NS, reply_info::ns_numrrsets, ub_packed_rrset_key::rk, reply_info::rrset_count, reply_info::rrsets, packed_rrset_key::type, VERB_ALGO, and verbose().

caps_failed_rcode()

int caps_failed_rcode

(

struct reply_info *

rep

)

see if reply has a 'useful' rcode for capsforid comparison, so not SERVFAIL or REFUSED, and thus NOERROR or NXDOMAIN.

Parameters

rep	reply to check.

Returns

true if the rcode is a bad type of message.

References reply_info::flags, and FLAGS_GET_RCODE.

iter_store_parentside_rrset()

void iter_store_parentside_rrset	(	struct module_env *	env,
		struct ub_packed_rrset_key *	rrset
	)

Store parent-side rrset in separate rrset cache entries for later last-resort * lookups in case the child-side versions of this information fails.

Parameters

env	environment with cache, time, ...
rrset	the rrset to store (copied). Failure to store is logged, but otherwise ignored.

References module_env::alloc, rrset_ref::id, rrset_ref::key, log_err(), module_env::now, packed_rrset_copy_alloc(), PACKED_RRSET_PARENT_SIDE, module_env::rrset_cache, rrset_cache_update(), and rrset_key_hash().

Referenced by iter_store_parentside_NS().

iter_store_parentside_NS()

void iter_store_parentside_NS	(	struct module_env *	env,
		struct reply_info *	rep
	)

Store parent-side NS records from a referral message.

Parameters

env	environment with cache, time, ...
rep	response with NS rrset. Failure to store is logged, but otherwise ignored.

References iter_store_parentside_rrset(), log_rrset_key(), reply_get_NS_rrset(), and VERB_ALGO.

iter_store_parentside_neg()

void iter_store_parentside_neg	(	struct module_env *	env,
		struct query_info *	qinfo,
		struct reply_info *	rep
	)

Store parent-side negative element, the parentside rrset does not exist, creates an rrset with empty rdata in the rrset cache with PARENTSIDE flag.

Parameters

env	environment with cache, time, ...
qinfo	the identity of the rrset that is missing.
rep	delegation response or answer response, to glean TTL from. (malloc) failure is logged but otherwise ignored.

References packed_rrset_data::count, lruhash_entry::data, packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, packed_rrset_key::flags, lruhash_entry::hash, lruhash_entry::key, log_err(), NORR_TTL, packed_rrset_ptr_fixup(), query_info::qclass, query_info::qname, query_info::qname_len, query_info::qtype, regional_alloc(), regional_alloc_init(), regional_alloc_zero(), reply_get_NS_rrset(), ub_packed_rrset_key::rk, packed_rrset_data::rr_len, packed_rrset_data::rr_ttl, packed_rrset_key::rrset_class, reply_info::rrset_count, rrset_key_hash(), rrset_trust_ans_noAA, reply_info::rrsets, packed_rrset_data::rrsig_count, module_env::scratch, packed_rrset_data::trust, packed_rrset_data::ttl, packed_rrset_key::type, and ub_packed_rrset_ttl().

Referenced by processFinished().

iter_lookup_parent_NS_from_cache()

int iter_lookup_parent_NS_from_cache	(	struct module_env *	env,
		struct delegpt *	dp,
		struct regional *	region,
		struct query_info *	qinfo
	)

Add parent NS record if that exists in the cache.

This is both new information and acts like a timeout throttle on retries.

Parameters

env	query env with rrset cache and time.
dp	delegation point to store result in. Also this dp is used to see which NS name is needed.
region	region to alloc result in.
qinfo	pertinent information, the qclass.

Returns

false on malloc failure. if true, the routine worked and if such cached information existed dp->has_parent_side_NS is set true.

References delegpt_rrset_add_ns(), ub_packed_rrset_key::entry, delegpt::has_parent_side_NS, LDNS_RR_TYPE_NS, lruhash_entry::lock, log_rrset_key(), delegpt::name, delegpt::namelen, module_env::now, PACKED_RRSET_PARENT_SIDE, query_info::qclass, module_env::rrset_cache, rrset_cache_lookup(), and VERB_ALGO.

iter_lookup_parent_glue_from_cache()

int iter_lookup_parent_glue_from_cache	(	struct module_env *	env,
		struct delegpt *	dp,
		struct regional *	region,
		struct query_info *	qinfo
	)

Add parent-side glue if that exists in the cache.

This is both new information and acts like a timeout throttle on retries to fetch them.

Parameters

env	query env with rrset cache and time.
dp	delegation point to store result in. Also this dp is used to see which NS name is needed.
region	region to alloc result in.
qinfo	pertinent information, the qclass.

Returns

: true, it worked, no malloc failures, and new addresses (lame) have been added, giving extra options as query targets.

References delegpt_add_rrset_A(), delegpt_add_rrset_AAAA(), delegpt_count_targets(), delegpt_ns::done_pside4, delegpt_ns::done_pside6, ub_packed_rrset_key::entry, LDNS_RR_TYPE_A, LDNS_RR_TYPE_AAAA, lruhash_entry::lock, log_err(), log_rrset_key(), delegpt_ns::name, delegpt_ns::namelen, delegpt_ns::next, module_env::now, delegpt::nslist, PACKED_RRSET_PARENT_SIDE, query_info::qclass, module_env::rrset_cache, rrset_cache_lookup(), and VERB_ALGO.

iter_get_next_root()

int iter_get_next_root	(	struct iter_hints *	hints,
		struct iter_forwards *	fwd,
		uint16_t *	c
	)

Lookup next root-hint or root-forward entry.

Parameters

hints	the hints.
fwd	the forwards.
c	the class to start searching at. 0 means find first one.

Returns

false if no classes found, true if found and returned in c.

References forwards_next_root(), and hints_next_root().

Referenced by processCollectClass().

iter_scrub_ds()

void iter_scrub_ds	(	struct dns_msg *	msg,
		struct ub_packed_rrset_key *	ns,
		uint8_t *	z
	)

Remove DS records that are inappropriate before they are cached.

Parameters

msg	the response to scrub.
ns	RRSET that is the NS record for the referral. if NULL, then all DS records are removed from the authority section.
z	zone name that the response is from.

References reply_info::an_numrrsets, packed_rrset_key::dname, dname_subdomain_c(), LDNS_RR_TYPE_DS, log_nametypeclass(), reply_info::ns_numrrsets, query_dname_compare(), dns_msg::rep, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrset_count, reply_info::rrsets, packed_rrset_key::type, and VERB_ALGO.

Referenced by processQueryResponse().

iter_scrub_nxdomain()

void iter_scrub_nxdomain

(

struct dns_msg *

msg

)

Prepare an NXDOMAIN message to be used for a subdomain answer by removing all RRs from the ANSWER section.

Parameters

msg	the response to scrub.

References reply_info::an_numrrsets, dns_msg::rep, reply_info::rrset_count, and reply_info::rrsets.

iter_dec_attempts()

void iter_dec_attempts	(	struct delegpt *	dp,
		int	d
	)

Remove query attempts from all available ips.

For 0x20.

Parameters

dp	delegpt.
d	decrease.

References delegpt_addr::attempts, delegpt_addr::next_result, delegpt_addr::next_target, OUTBOUND_MSG_RETRY, delegpt::result_list, and delegpt::target_list.

Referenced by process_response().

iter_merge_retry_counts()

void iter_merge_retry_counts	(	struct delegpt *	dp,
		struct delegpt *	old
	)

Add retry counts from older delegpt to newer delegpt.

Does not waste time on timeout'd (or other failing) addresses.

Parameters

dp	new delegationpoint.
old	old delegationpoint.

References delegpt_addr::addr, delegpt_addr::addrlen, delegpt_addr::attempts, delegpt_find_addr(), log_addr(), delegpt_addr::next_target, delegpt_addr::next_usable, OUTBOUND_MSG_RETRY, delegpt::target_list, delegpt::usable_list, and VERB_ALGO.

iter_ds_toolow()

int iter_ds_toolow	(	struct dns_msg *	msg,
		struct delegpt *	dp
	)

See if a DS response (type ANSWER) is too low: a nodata answer with a SOA record in the authority section at-or-below the qchase.qname.

Also returns true if we are not sure (i.e. empty message, CNAME nosig).

Parameters

msg	the response.
dp	the dp name is used to check if the RRSIG gives a clue that it was originated from the correct nameserver.

Returns

true if too low.

References reply_info::an_numrrsets, packed_rrset_key::dname, dname_subdomain_c(), LDNS_RR_TYPE_CNAME, LDNS_RR_TYPE_DNAME, LDNS_RR_TYPE_DS, LDNS_RR_TYPE_SOA, delegpt::name, reply_info::ns_numrrsets, dns_msg::qinfo, query_info::qname, query_dname_compare(), dns_msg::rep, ub_packed_rrset_key::rk, reply_info::rrsets, packed_rrset_key::type, and val_find_rrset_signer().

iter_dp_cangodown()

int iter_dp_cangodown	(	struct query_info *	qinfo,
		struct delegpt *	dp
	)

See if delegpt can go down a step to the qname or not.

Parameters

qinfo	the query name looked up.
dp	checked if the name can go lower to the qname

Returns

true if can go down, false if that would not be possible. the current response seems to be the one and only, best possible, response.

References dname_count_labels(), delegpt::name, delegpt::namelabs, query_info::qname, and query_dname_compare().

iter_stub_fwd_no_cache()

int iter_stub_fwd_no_cache	(	struct module_qstate *	qstate,
		struct query_info *	qinf
	)

Lookup if no_cache is set in stub or fwd.

Parameters

qstate	query state with env with hints and fwds.
qinf	query name to lookup for.

Returns

true if no_cache is set in stub or fwd.

References dname_str(), dname_strict_subdomain(), iter_hints_stub::dp, module_qstate::env, forwards_lookup(), module_env::fwds, module_env::hints, hints_lookup_stub(), delegpt::name, delegpt::namelabs, query_info::qclass, query_info::qname, VERB_ALGO, and verbose().