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Code Issues Releases Wiki Activity

snapshot; start noting negative cache ttls

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This commit is contained in:
Michael Graff
1999-11-04 06:46:05 +00:00
parent a7c6cb0a8c
commit 3d12fa7e76
1 changed files with 57 additions and 107 deletions
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164
lib/dns/adb.c
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@@ -319,6 +319,8 @@ static isc_result_t dbfind_a6(dns_adbname_t *, isc_stdtime_t, isc_boolean_t);
#define NAME_FETCH_V6(n) (NAME_FETCH_AAAA(n) || NAME_FETCH_A6(n))
#define NAME_FETCH(n) (NAME_FETCH_V4(n) || NAME_FETCH_V6(n))
#define EXPIRE_OK(exp, now) ((exp == INT_MAX) || (exp < now))
#define ENTER_LEVEL 50
#define EXIT_LEVEL ENTER_LEVEL
#define CLEAN_LEVEL 100
@@ -585,19 +587,20 @@ check_expire_namehooks(dns_adbname_t *name, isc_stdtime_t now)
/*
* Check to see if we need to remove the v4 addresses
*/
if (!NAME_FETCH_V4(name) && (name->expire_v4 < now)) {
if (!NAME_FETCH_V4(name) && EXPIRE_OK(name->expire_v4, now)) {
DP(DEF_LEVEL, "expiring v4 for name %p", name);
clean_namehooks(adb, &name->v4);
name->expire_v4 = INT_MAX;
name->partial_result &= ~DNS_ADBFIND_INET;
}
/*
* Check to see if we need to remove the v6 addresses
*/
if (!NAME_FETCH_V6(name) && (name->expire_v6 < now)) {
if (!NAME_FETCH_V6(name) && EXPIRE_OK(name->expire_v6, now)) {
DP(DEF_LEVEL, "expiring v6 for name %p", name);
clean_namehooks(adb, &name->v6);
name->expire_v6 = INT_MAX;
name->partial_result &= ~DNS_ADBFIND_INET6;
}
}
@@ -1656,7 +1659,7 @@ shutdown_task(isc_task_t *task, isc_event_t *ev)
* name bucket must be locked; adb may be locked; no other locks held.
*/
static void
check_expire_name(dns_adbname_t **namep)
check_expire_name(dns_adbname_t **namep, isc_stdtime_t now)
{
dns_adbname_t *name;
@@ -1668,6 +1671,10 @@ check_expire_name(dns_adbname_t **namep)
return;
if (NAME_FETCH(name))
return;
if (!EXPIRE_OK(name->expire_v4, now))
return;
if (!EXPIRE_OK(name->expire_v6, now))
return;
/*
* The name is empty. Delete it.
@@ -1695,7 +1702,7 @@ cleanup_names(dns_adb_t *adb, int bucket, isc_stdtime_t now)
while (name != NULL) {
next_name = ISC_LIST_NEXT(name, plink);
check_expire_namehooks(name, now);
check_expire_name(&name);
check_expire_name(&name, now);
name = next_name;
}
UNLOCK(&adb->namelocks[bucket]);
@@ -2074,6 +2081,7 @@ dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
* start fetches.
*/
if (!HAVE_INET(adbname) && !NAME_FETCH_V4(adbname)
&& EXPIRE_OK(adbname->expire_v4, now)
&& WANT_INET(wanted_addresses)) {
result = dbfind_name(adbname, now, use_hints, dns_rdatatype_a);
if (result == ISC_R_SUCCESS) {
@@ -2097,6 +2105,7 @@ dns_adb_createfind(dns_adb_t *adb, isc_task_t *task, isc_taskaction_t action,
v6:
if (!HAVE_INET6(adbname) && !NAME_FETCH_V6(adbname)
&& EXPIRE_OK(adbname->expire_v6, now)
&& WANT_INET6(wanted_addresses)) {
result = dbfind_a6(adbname, now, use_hints);
if (result == ISC_R_SUCCESS) {
@@ -2770,6 +2779,21 @@ dbfind_name(dns_adbname_t *adbname, isc_stdtime_t now,
*/
result = import_rdataset(adbname, &rdataset, now);
break;
case DNS_R_NCACHENXDOMAIN:
case DNS_R_NCACHENXRRSET:
/*
* We found a negative cache entry. Pull the TTL from it
* so we won't ask again for a while.
*/
if (rdtype == dns_rdatatype_a) {
DP(1, "adb name %p: Caching negative entry for A",
adbname);
adbname->expire_v4 = rdataset.ttl + now;
} else {
DP(1, "adb name %p: Caching negative entry for AAAA",
adbname);
adbname->expire_v6 = rdataset.ttl + now;
}
}
/* Need to handle "no such name" XXXMLG */
@@ -2816,6 +2840,13 @@ dbfind_a6(dns_adbname_t *adbname, isc_stdtime_t now, isc_boolean_t use_hints)
(void)dns_a6_foreach(&a6ctx, &rdataset);
result = ISC_R_SUCCESS;
break;
case DNS_R_NCACHENXDOMAIN:
case DNS_R_NCACHENXRRSET:
/*
* We found a negative cache entry. Pull the TTL from it
* so we won't ask again for a while.
*/
adbname->expire_v6 = rdataset.ttl + now;
}
/* Need to handle "no such name" XXXMLG */
@@ -2826,7 +2857,7 @@ dbfind_a6(dns_adbname_t *adbname, isc_stdtime_t now, isc_boolean_t use_hints)
}
static void
fetch_callback_v4(isc_task_t *task, isc_event_t *ev)
fetch_callback(isc_task_t *task, isc_event_t *ev)
{
dns_fetchevent_t *dev;
dns_adbname_t *name;
@@ -2836,6 +2867,7 @@ fetch_callback_v4(isc_task_t *task, isc_event_t *ev)
isc_eventtype_t ev_status;
isc_stdtime_t now;
isc_result_t result;
unsigned int address_type;
(void)task;
@@ -2849,10 +2881,22 @@ fetch_callback_v4(isc_task_t *task, isc_event_t *ev)
bucket = name->lock_bucket;
LOCK(&adb->namelocks[bucket]);
INSIST(NAME_FETCH_A(name));
fetch = name->fetch_a;
name->fetch_a = NULL;
INSIST(fetch->fetch == dev->fetch);
INSIST(name->fetch_a != NULL || name->fetch_aaaa != NULL);
address_type = 0;
if (NAME_FETCH_A(name)) {
if (name->fetch_a->fetch == dev->fetch) {
address_type = DNS_ADBFIND_INET;
fetch = name->fetch_a;
name->fetch_a = NULL;
}
} else if (NAME_FETCH_AAAA(name)) {
if (name->fetch_aaaa->fetch == dev->fetch) {
address_type = DNS_ADBFIND_INET6;
fetch = name->fetch_aaaa;
name->fetch_aaaa = NULL;
}
}
INSIST(address_type != 0);
dns_resolver_destroyfetch(adb->view->resolver, &fetch->fetch);
dev->fetch = NULL;
@@ -2911,101 +2955,7 @@ fetch_callback_v4(isc_task_t *task, isc_event_t *ev)
free_adbfetch(adb, &fetch);
isc_event_free(&ev);
clean_finds_at_name(name, ev_status, DNS_ADBFIND_INET);
UNLOCK(&adb->namelocks[bucket]);
return;
}
static void
fetch_callback_aaaa(isc_task_t *task, isc_event_t *ev)
{
dns_fetchevent_t *dev;
dns_adbname_t *name;
dns_adb_t *adb;
dns_adbfetch_t *fetch;
int bucket;
isc_eventtype_t ev_status;
isc_stdtime_t now;
isc_result_t result;
(void)task;
INSIST(ev->type == DNS_EVENT_FETCHDONE);
dev = (dns_fetchevent_t *)ev;
name = ev->arg;
INSIST(DNS_ADBNAME_VALID(name));
adb = name->adb;
INSIST(DNS_ADB_VALID(adb));
bucket = name->lock_bucket;
LOCK(&adb->namelocks[bucket]);
INSIST(NAME_FETCH_AAAA(name));
fetch = name->fetch_aaaa;
name->fetch_aaaa = NULL;
INSIST(fetch->fetch == dev->fetch);
dns_resolver_destroyfetch(adb->view->resolver, &fetch->fetch);
dev->fetch = NULL;
ev_status = DNS_EVENT_ADBNOMOREADDRESSES;
/*
* Cleanup things we don't care about.
*/
if (dev->node != NULL)
dns_db_detachnode(dev->db, &dev->node);
if (dev->db != NULL)
dns_db_detach(&dev->db);
/*
* If this name is marked as dead, clean up, throwing away
* potentially good data.
*/
if (NAME_DEAD(name)) {
isc_boolean_t decr_adbrefcnt;
free_adbfetch(adb, &fetch);
isc_event_free(&ev);
kill_name(&name, DNS_EVENT_ADBCANCELED);
decr_adbrefcnt = ISC_FALSE;
if (adb->name_sd[bucket] && (adb->name_refcnt[bucket] == 0))
decr_adbrefcnt = ISC_TRUE;
UNLOCK(&adb->namelocks[bucket]);
if (decr_adbrefcnt)
dec_adb_irefcnt(adb, ISC_TRUE);
return;
}
/*
* Did we get back junk? If so, and there are no more fetches
* sitting out there, tell all the finds about it.
*/
if (dev->result != ISC_R_SUCCESS)
goto out;
/*
* We got something potentially useful.
*/
result = isc_stdtime_get(&now);
if (result == ISC_R_SUCCESS)
result = import_rdataset(name, &fetch->rdataset, now);
if (result == ISC_R_SUCCESS)
ev_status = DNS_EVENT_ADBMOREADDRESSES;
out:
free_adbfetch(adb, &fetch);
isc_event_free(&ev);
clean_finds_at_name(name, ev_status, DNS_ADBFIND_INET6);
clean_finds_at_name(name, ev_status, address_type);
UNLOCK(&adb->namelocks[bucket]);
@@ -3202,7 +3152,7 @@ fetch_name_v4(dns_adbname_t *adbname, isc_stdtime_t now)
result = dns_resolver_createfetch(adb->view->resolver, &adbname->name,
dns_rdatatype_a, &fname,
&nameservers, NULL, 0,
adb->task, fetch_callback_v4,
adb->task, fetch_callback,
adbname, &fetch->rdataset, NULL,
&fetch->fetch);
if (result != ISC_R_SUCCESS)
@@ -3259,7 +3209,7 @@ fetch_name_aaaa(dns_adbname_t *adbname, isc_stdtime_t now)
result = dns_resolver_createfetch(adb->view->resolver, &adbname->name,
dns_rdatatype_aaaa, &fname,
&nameservers, NULL, 0,
adb->task, fetch_callback_aaaa,
adb->task, fetch_callback,
adbname, &fetch->rdataset, NULL,
&fetch->fetch);
if (result != ISC_R_SUCCESS)