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Code Issues Releases Wiki Activity

Partially working negative caching.

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This commit is contained in:
Bob Halley
1999-10-16 00:48:34 +00:00
parent 66b2f0d4bf
commit 3706171484
1 changed files with 115 additions and 2 deletions
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117
lib/dns/resolver.c
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@@ -31,6 +31,7 @@
#include <dns/db.h>
#include <dns/events.h>
#include <dns/message.h>
#include <dns/ncache.h>
#include <dns/dispatch.h>
#include <dns/resolver.h>
#include <dns/rdata.h>
@@ -1192,6 +1193,102 @@ cache_message(fetchctx_t *fctx) {
return (result);
}
static inline isc_result_t
ncache_message(fetchctx_t *fctx, dns_rdatatype_t covers) {
isc_result_t result, eresult;
dns_name_t *name;
dns_resolver_t *res;
dns_db_t **adbp;
dns_dbnode_t *node, **anodep;
dns_rdataset_t *ardataset;
isc_boolean_t need_validation;
dns_fixedname_t foundname;
dns_name_t *fname, *aname;
dns_fetchevent_t *event;
void *data;
isc_stdtime_t now;
result = isc_stdtime_get(&now);
if (result != ISC_R_SUCCESS)
return (result);
res = fctx->res;
need_validation = ISC_FALSE;
eresult = ISC_R_SUCCESS;
name = &fctx->name;
/*
* Is DNSSEC validation required for this name?
*/
dns_fixedname_init(&foundname);
fname = dns_fixedname_name(&foundname);
data = NULL;
result = dns_rbt_findname(res->view->secroots, name, fname, &data);
if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH) {
/*
* This name is at or below one of the view's security roots,
* so DNSSEC validation is required.
*/
need_validation = ISC_TRUE;
} else if (result != ISC_R_NOTFOUND) {
/*
* Something bad happened.
*/
return (result);
}
LOCK(&res->buckets[fctx->bucketnum].lock);
adbp = NULL;
aname = NULL;
anodep = NULL;
ardataset = NULL;
event = ISC_LIST_HEAD(fctx->events);
if (event != NULL) {
adbp = &event->db;
aname = dns_fixedname_name(&event->foundname);
result = dns_name_concatenate(name, NULL, aname, NULL);
if (result != ISC_R_SUCCESS)
goto unlock;
anodep = &event->node;
ardataset = event->rdataset;
}
node = NULL;
result = dns_db_findnode(res->view->cachedb, name, ISC_TRUE,
&node);
if (result != ISC_R_SUCCESS)
goto unlock;
result = dns_ncache_add(fctx->rmessage, res->view->cachedb, node,
covers, now, ardataset);
if (result == DNS_R_UNCHANGED) {
INSIST(0);
} else if (result == ISC_R_SUCCESS) {
if (covers == dns_rdatatype_any)
eresult = DNS_R_NCACHENXDOMAIN;
else
eresult = DNS_R_NCACHENXRRSET;
} else
goto unlock;
fctx->have_answer = ISC_TRUE;
if (event != NULL) {
event->result = eresult;
dns_db_attach(res->view->cachedb, adbp);
*anodep = node;
node = NULL;
clone_results(fctx);
}
unlock:
UNLOCK(&res->buckets[fctx->bucketnum].lock);
if (node != NULL)
dns_db_detachnode(res->view->cachedb, &node);
return (result);
}
static inline void
mark_related(dns_name_t *name, dns_rdataset_t *rdataset,
isc_boolean_t external)
@@ -1467,7 +1564,7 @@ noanswer_response(fetchctx_t *fctx) {
message = fctx->rmessage;
negative_response = ISC_FALSE;
/*
* We have to figure out if this is a negative response, or a
* referral. We start by examining the rcode.
@@ -1644,6 +1741,7 @@ query_response(isc_task_t *task, isc_event_t *event) {
isc_boolean_t keep_trying, broken_server, get_nameservers;
dns_message_t *message;
fetchctx_t *fctx;
dns_rdatatype_t covers;
REQUIRE(VALID_QUERY(query));
fctx = query->fctx;
@@ -1656,6 +1754,7 @@ query_response(isc_task_t *task, isc_event_t *event) {
keep_trying = ISC_FALSE;
broken_server = ISC_FALSE;
get_nameservers = ISC_FALSE;
covers = 0;
LOCK(&fctx->res->lock);
INSIST(fctx->state == fetchstate_active);
@@ -1752,7 +1851,21 @@ query_response(isc_task_t *task, isc_event_t *event) {
*/
get_nameservers = ISC_TRUE;
keep_trying = ISC_TRUE;
} else if (result != ISC_R_SUCCESS) {
} else if (result == ISC_R_SUCCESS) {
/*
* We have a negative response.
*/
if (message->rcode == dns_rcode_nxdomain)
covers = dns_rdatatype_any;
else
covers = fctx->type;
result = ncache_message(fctx, covers);
if (result != ISC_R_SUCCESS)
goto done;
} else {
/*
* Something has gone wrong.
*/
if (result == DNS_R_FORMERR)
broken_server = ISC_TRUE;
keep_trying = ISC_TRUE;