dns.h File Reference

This file contains the DNS cache. More...

#include "util/storage/lruhash.h"
#include "util/data/msgreply.h"

Data Structures

struct  dns_msg
 Region allocated message reply. More...

Functions

int dns_cache_store (struct module_env *env, struct query_info *qinf, struct reply_info *rep, int is_referral)
 Allocate a dns_msg with malloc/alloc structure and store in dns cache.
void dns_cache_store_msg (struct module_env *env, struct query_info *qinfo, hashvalue_t hash, struct reply_info *rep)
 Store message in the cache.
struct delegptdns_cache_find_delegation (struct module_env *env, uint8_t *qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, struct regional *region, struct dns_msg **msg, uint32_t timenow)
 Find a delegation from the cache.
struct dns_msgdns_cache_lookup (struct module_env *env, uint8_t *qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, struct regional *region, struct regional *scratch)
 Find cached message.
int cache_fill_missing (struct module_env *env, uint16_t qclass, struct regional *region, struct delegpt *dp)
 find and add A and AAAA records for missing nameservers in delegpt


Detailed Description

This file contains the DNS cache.


Function Documentation

int dns_cache_store ( struct module_env env,
struct query_info qinf,
struct reply_info rep,
int  is_referral 
)

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. this is allocated in a region, and will be copied to malloc area before insertion.
rep,: reply in dns_msg from dns_alloc_msg for example. this is allocated in a region, and will be copied to malloc area before insertion.
is_referral,: If true, then the given message to be stored is a referral. The cache implementation may use this as a hint. It will store only the RRsets, not the message.
Returns:
0 on alloc error (out of memory).

References module_env::alloc, BIT_AA, BIT_CD, BIT_QR, BIT_RA, lruhash_entry::data, dns_cache_store_msg(), ub_packed_rrset_key::entry, reply_info::flags, ub_packed_rrset_key::id, rrset_ref::id, rrset_ref::key, memdup(), module_env::now, packed_rrset_ttl_add(), query_info::qname, query_info::qname_len, query_info_hash(), reply_info_copy(), reply_info_parsedelete(), module_env::rrset_cache, rrset_cache_update(), reply_info::rrset_count, and reply_info::rrsets.

Referenced by iter_dns_store(), and processFinished().

void dns_cache_store_msg ( struct module_env env,
struct query_info qinfo,
hashvalue_t  hash,
struct reply_info rep 
)

Store message in the cache.

Stores in message cache and rrset cache. Both qinfo and rep should be malloced and are put in the cache. They should not be used after this call, as they are then in shared cache. Does not return errors, they are logged and only lead to less cache.

Parameters:
env,: module environment with the DNS cache.
qinfo,: query info
hash,: hash over qinfo.
rep,: reply info, together with qinfo makes up the message. Adjusts the reply info TTLs to absolute time.

References module_env::alloc, msgreply_entry::entry, ub_packed_rrset_key::id, rrset_ref::id, rrset_ref::key, log_err(), module_env::msg_cache, module_env::now, query_info_entrysetup(), reply_info::ref, reply_info_set_ttls(), reply_info_sortref(), reply_info::rrset_count, reply_info::rrsets, slabhash_insert(), store_rrsets(), reply_info::ttl, VERB_ALGO, and verbose().

Referenced by dns_cache_store().

struct delegpt* dns_cache_find_delegation ( struct module_env env,
uint8_t *  qname,
size_t  qnamelen,
uint16_t  qtype,
uint16_t  qclass,
struct regional region,
struct dns_msg **  msg,
uint32_t  timenow 
) [read]

Find a delegation from the cache.

Parameters:
env,: module environment with the DNS cache.
qname,: query name.
qnamelen,: length of qname.
qtype,: query type.
qclass,: query class.
region,: where to allocate result delegation.
msg,: if not NULL, delegation message is returned here, synthesized from the cache.
timenow,: the time now, for checking if TTL on cache entries is OK.
Returns:
new delegation or NULL on error or if not found in cache.

References create_msg(), lruhash_entry::data, delegpt_create(), delegpt_rrset_add_ns(), delegpt_set_name(), packed_rrset_key::dname, ub_packed_rrset_key::entry, find_add_addrs(), find_add_ds(), find_closest_of_type(), lruhash_entry::lock, log_err(), and ub_packed_rrset_key::rk.

Referenced by answer_norec_from_cache(), and processInitRequest().

struct dns_msg* dns_cache_lookup ( struct module_env env,
uint8_t *  qname,
size_t  qnamelen,
uint16_t  qtype,
uint16_t  qclass,
struct regional region,
struct regional scratch 
) [read]

Find cached message.

Parameters:
env,: module environment with the DNS cache.
qname,: query name.
qnamelen,: length of qname.
qtype,: query type.
qclass,: query class.
region,: where to allocate result.
scratch,: where to allocate temporary data.
Returns:
new response message (alloced in region, rrsets do not have IDs). or NULL on error or if not found in cache. TTLs are made relative to the current time.

References lruhash_entry::data, ub_packed_rrset_key::entry, find_closest_of_type(), lruhash_entry::key, msgreply_entry::key, lruhash_entry::lock, module_env::msg_cache, module_env::now, query_info::qclass, query_info::qname, query_info::qname_len, query_info::qtype, query_info_hash(), module_env::rrset_cache, rrset_cache_lookup(), rrset_msg(), rrset_trust_add_AA, rrset_trust_add_noAA, slabhash_lookup(), synth_dname_msg(), tomsg(), and packed_rrset_data::trust.

Referenced by processInitRequest().

int cache_fill_missing ( struct module_env env,
uint16_t  qclass,
struct regional region,
struct delegpt dp 
)

find and add A and AAAA records for missing nameservers in delegpt

Parameters:
env,: module environment with rrset cache
qclass,: which class to look in.
region,: where to store new dp info.
dp,: delegation point to fill missing entries.
Returns:
false on alloc failure.

References delegpt_add_rrset_A(), delegpt_add_rrset_AAAA(), ub_packed_rrset_key::entry, lruhash_entry::lock, log_nametypeclass(), delegpt_ns::name, delegpt_ns::namelen, delegpt_ns::next, module_env::now, delegpt::nslist, delegpt_ns::resolved, module_env::rrset_cache, rrset_cache_lookup(), and VERB_ALGO.

Referenced by processQueryResponse().


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