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Fix problem with delegation where glue has expired.

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git-svn-id: file:///svn/unbound/trunk@1837 be551aaa-1e26-0410-a405-d3ace91eadb9
This commit is contained in:
Wouter Wijngaards
2009-09-17 14:36:06 +00:00
parent 75fbd42ca3
commit c4cfcdab6b
4 changed files with 324 additions and 9 deletions
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iterator/iter_utils.c
+55 -4
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@@ -61,6 +61,9 @@
#include "util/fptr_wlist.h"
#include "validator/val_anchor.h"
/** time when nameserver glue is said to be 'recent' */
#define SUSPICION_RECENT_EXPIRY 86400
/** fillup fetch policy array */
static void
fetch_fill(struct iter_env* ie, const char* str)
@@ -402,6 +405,54 @@ iter_ns_probability(struct ub_randstate* rnd, int n, int m)
return (sel < n);
}
int iter_suspect_exists(struct query_info* qinfo, struct delegpt* dp,
struct module_env* env)
{
struct ub_packed_rrset_key* r;
if(qinfo->qtype != LDNS_RR_TYPE_A && qinfo->qtype != LDNS_RR_TYPE_AAAA)
return 0; /* not glue type */
if(!dname_subdomain_c(qinfo->qname, dp->name))
return 0; /* not in-zone */
if(!delegpt_find_ns(dp, qinfo->qname, qinfo->qname_len))
return 0; /* not glue */
/* do we suspect that it exists? lookup with time=0 */
r = rrset_cache_lookup(env->rrset_cache, qinfo->qname,
qinfo->qname_len, qinfo->qtype, qinfo->qclass, 0, 0, 0);
if(r) {
struct packed_rrset_data* d = (struct packed_rrset_data*)
r->entry.data;
/* if it is valid, no need for queries to parent zone */
if(*env->now <= d->ttl) {
lock_rw_unlock(&r->entry.lock);
return 0;
}
/* was it recently expired? */
if( (*env->now - d->ttl) <= SUSPICION_RECENT_EXPIRY) {
verbose(VERB_ALGO, "suspect glue at parent: "
"rrset recently expired");
lock_rw_unlock(&r->entry.lock);
return 1;
}
lock_rw_unlock(&r->entry.lock);
}
/* so, qinfo not there, does the other A/AAAA type exist in cache? */
r=rrset_cache_lookup(env->rrset_cache, qinfo->qname, qinfo->qname_len,
(qinfo->qtype==LDNS_RR_TYPE_A)?LDNS_RR_TYPE_AAAA:LDNS_RR_TYPE_A,
qinfo->qclass, 0, *env->now, 0);
if(r) {
/* it exists and explains why the glue is there */
lock_rw_unlock(&r->entry.lock);
return 0;
}
/* neither exist, so logically, one should exist for a nameserver */
verbose(VERB_ALGO, "suspect glue at parent: "
"neither A nor AAAA exist in cache");
return 1;
}
/** detect dependency cycle for query and target */
static int
causes_cycle(struct module_qstate* qstate, uint8_t* name, size_t namelen,
@@ -446,19 +497,19 @@ iter_dp_is_useless(struct query_info* qinfo, uint16_t qflags,
{
struct delegpt_ns* ns;
/* check:
* o RD qflag is off.
* o no addresses are provided.
* o all NS items are required glue.
* o no addresses are provided.
* o RD qflag is on.
* OR
* o RD qflag is off.
* o no addresses are provided.
* o RD qflag is on.
* o the query is for one of the nameservers in dp,
* and that nameserver is a glue-name for this dp.
*/
if(!(qflags&BIT_RD))
return 0;
/* either available or unused targets */
if(dp->usable_list || dp->result_list)
if(dp->usable_list || dp->result_list)
return 0;
/* see if query is for one of the nameservers, which is glue */