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- fix to locate nameservers for DS lookup with NS fetches.

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git-svn-id: file:///svn/unbound/trunk@2645 be551aaa-1e26-0410-a405-d3ace91eadb9
This commit is contained in:
Wouter Wijngaards
2012-03-19 15:44:21 +00:00
parent d17f39416b
commit 0d5441bd8a
6 changed files with 302 additions and 0 deletions
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iterator/iterator.c
+103
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@@ -1526,6 +1526,60 @@ processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
/**
* Try to find the NS record set that will resolve a qtype DS query. Due
* to grandparent/grandchild reasons we did not get a proper lookup right
* away. We need to create type NS queries until we get the right parent
* for this lookup. We add labels to the delegation point - whose name is
* storage for where we are (with empty other content). Until we find an
* NS record, then we try the query again (which can result in doing this
* again). Or we go too low, it is not possible to resolve, servfail.
*
* @param qstate: query state.
* @param iq: iterator query state.
* @param id: module id.
* @return true if the event requires more immediate processing, false if
* not. This is generally only true when forwarding the request to
* the final state (i.e., on answer).
*/
static int
processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq,
int id)
{
int qlab = dname_count_labels(iq->qchase.qname);
struct module_qstate* subq = NULL;
verbose(VERB_ALGO, "processDSNSFind");
if(dname_subdomain_c(iq->dp->name, iq->qchase.qname) ||
qlab == iq->dp->namelabs+1)
/* we are too low - fail (robust check) */
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
/* dp is used for storage, this is our state */
log_assert(!iq->dp->dp_type_mlc); /* if malloced this would leak */
iq->dp->nslist = NULL;
iq->dp->target_list = NULL;
iq->dp->usable_list = NULL;
iq->dp->result_list = NULL;
iq->state = DSNS_FIND_STATE;
/* add one label to the dp */
iq->dp->name = iq->qchase.qname;
iq->dp->namelen = iq->qchase.qname_len;
/* we have qlab labels we want namelabs+1 labels */
dname_remove_labels(&iq->dp->name, &iq->dp->namelen,
qlab - (iq->dp->namelabs+1));
iq->dp->namelabs++;
/* spawn NS lookup (validation not needed, this is for DS lookup) */
log_nametypeclass(VERB_ALGO, "fetch nameservers",
iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0)) {
return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
}
return 0;
}
/**
* This is the request event state where the request will be sent to one of
* its current query targets. This state also handles issuing target lookup
@@ -1847,6 +1901,12 @@ processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
(iq->response->rep->an_numrrsets?"ANSWER":
"nodata ANSWER"));
}
/* if qtype is DS, check we have the right level of answer,
* like grandchild answer but we need the middle, reject it */
if(iq->qchase.qtype == LDNS_RR_TYPE_DS
&& iter_ds_toolow(iq->response)
&& iter_dp_cangodown(&iq->qchase, iq->dp))
return processDSNSFind(qstate, iq, id);
if(!iter_dns_store(qstate->env, &iq->response->qinfo,
iq->response->rep, 0, qstate->prefetch_leeway,
iq->dp&&iq->dp->has_parent_side_NS,
@@ -2246,6 +2306,41 @@ processTargetResponse(struct module_qstate* qstate, int id,
}
}
/**
* Process response for DS NS Find queries, that attempt to find the delegation
* point where we ask the DS query from.
*
* @param qstate: query state.
* @param id: module id.
* @param forq: super query state.
*/
static void
processDSNSResponse(struct module_qstate* qstate, int id,
struct module_qstate* forq)
{
struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
/* if the finished (iq->response) query has no NS set: continue
* down to look for the right dp; nothing to change, do DPNSstate */
if(qstate->return_rcode != LDNS_RCODE_NOERROR)
return; /* seek further */
/* find the NS RRset (without allowing CNAMEs) */
if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
qstate->qinfo.qclass)){
return; /* seek further */
}
/* else, store as DP and continue at querytargets */
foriq->state = QUERYTARGETS_STATE;
foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
if(!foriq->dp) {
log_err("out of memory in dsns dp alloc");
return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
}
/* success, go query the querytargets in the new dp (and go down) */
}
/**
* Process response for qclass=ANY queries for a particular class.
* Append to result or error-exit.
@@ -2481,6 +2576,9 @@ iter_inform_super(struct module_qstate* qstate, int id,
{
if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
processClassResponse(qstate, id, super);
else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
super->minfo[id])->state == DSNS_FIND_STATE)
processDSNSResponse(qstate, id, super);
else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
error_supers(qstate, id, super);
else if(qstate->is_priming)
@@ -2530,6 +2628,9 @@ iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
case COLLECT_CLASS_STATE:
cont = processCollectClass(qstate, id);
break;
case DSNS_FIND_STATE:
cont = processDSNSFind(qstate, iq, id);
break;
case FINISHED_STATE:
cont = processFinished(qstate, iq, id);
break;
@@ -2760,6 +2861,8 @@ iter_state_to_string(enum iter_state state)
return "PRIME RESPONSE STATE";
case COLLECT_CLASS_STATE :
return "COLLECT CLASS STATE";
case DSNS_FIND_STATE :
return "DSNS FIND STATE";
case QUERY_RESP_STATE :
return "QUERY RESPONSE STATE";
case FINISHED_STATE :