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client quotas; added reference counting to ns_interface_t

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and ns_interfacemgr_t so that they can safely hold quota information
This commit is contained in:
Andreas Gustafsson
2000-01-11 21:18:22 +00:00
parent 5f2d1b96ac
commit 559b10cc8f
9 changed files with 487 additions and 196 deletions
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153
bin/named/client.c
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@@ -42,6 +42,7 @@
#include <named/server.h>
#include <named/update.h>
#include <named/notify.h>
#include <named/interfacemgr.h>
#define NS_CLIENT_TRACE
#ifdef NS_CLIENT_TRACE
@@ -131,6 +132,8 @@ maybe_free(ns_client_t *client) {
}
/* We have received our last event. */
ns_interface_detach(&client->interface);
ns_query_free(client);
isc_mempool_destroy(&client->sendbufs);
isc_timer_detach(&client->timer);
@@ -175,6 +178,12 @@ maybe_free(ns_client_t *client) {
UNLOCK(&manager->lock);
}
if (client->quota != NULL) {
isc_quota_release(client->quota);
client->quota = NULL;
}
CTRACE("free");
client->magic = 0;
isc_mem_put(client->mctx, client, sizeof *client);
@@ -234,20 +243,56 @@ ns_client_next(ns_client_t *client, isc_result_t result) {
client->udpsize = 512;
dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE);
if (client->oneshot) {
/* XXX should put in "idle client pool" instead. */
isc_task_shutdown(client->task);
return;
if (client->quota != NULL) {
isc_quota_release(client->quota);
client->quota = NULL;
}
if (client->mortal) {
/*
* This client object is supposed to die now, but if we
* have fewer client objects than planned due to
* quota exhaustion, don't.
*/
isc_boolean_t need_another_client = ISC_FALSE;
if (TCP_CLIENT(client)) {
LOCK(&client->interface->lock);
if (client->interface->ntcpcurrent <
client->interface->ntcptarget)
need_another_client = ISC_TRUE;
UNLOCK(&client->interface->lock);
} else {
/*
* The UDP client quota is enforced by making
* requests fail rather than by not listening
* for new ones. Therefore, there is always a
* full set of UDP clients listening.
*/
}
if (! need_another_client) {
/* XXX should put in "idle client pool" instead. */
isc_task_shutdown(client->task);
return;
}
}
if (client->dispevent != NULL) {
/*
* Give the processed dispatch event back to the dispatch.
* This tells the dispatch that we are ready to receive
* the next event.
*/
dns_dispatch_freeevent(client->dispatch, client->dispentry,
&client->dispevent);
} else if (TCP_CLIENT(client)) {
if (result == ISC_R_SUCCESS)
if (result == ISC_R_SUCCESS) {
client_read(client);
else {
} else {
/*
* There was an error processing a TCP request.
* It may have have left the connection out of
* sync. Close the connection and listen for a
* new one.
*/
if (client->tcpsocket != NULL) {
/*
* There should be no outstanding read
@@ -688,9 +733,6 @@ client_request(isc_task_t *task, isc_event_t *event) {
if (ra == ISC_TRUE)
client->attributes |= NS_CLIENTATTR_RA;
/* XXX conditionally */
(void) ns_client_replace(client);
/*
* Dispatch the request.
*/
@@ -737,7 +779,7 @@ client_timeout(isc_task_t *task, isc_event_t *event) {
static isc_result_t
client_create(ns_clientmgr_t *manager, ns_clienttype_t type,
ns_client_t **clientp)
ns_interface_t *ifp, ns_client_t **clientp)
{
ns_client_t *client;
isc_result_t result;
@@ -809,7 +851,9 @@ client_create(ns_clientmgr_t *manager, ns_clienttype_t type,
client->udpsize = 512;
client->next = NULL;
dns_name_init(&client->signername, NULL);
client->oneshot = ISC_FALSE;
client->mortal = ISC_FALSE;
client->quota = NULL;
client->interface = NULL;
ISC_LINK_INIT(client, link);
/*
@@ -821,6 +865,8 @@ client_create(ns_clientmgr_t *manager, ns_clienttype_t type,
if (result != ISC_R_SUCCESS)
goto cleanup_sendbufs;
ns_interface_attach(ifp, &client->interface);
CTRACE("create");
*clientp = client;
@@ -865,6 +911,7 @@ static void
client_newconn(isc_task_t *task, isc_event_t *event) {
ns_client_t *client = event->arg;
isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event;
isc_result_t result;
REQUIRE(event->type == ISC_SOCKEVENT_NEWCONN);
REQUIRE(NS_CLIENT_VALID(client));
@@ -874,7 +921,12 @@ client_newconn(isc_task_t *task, isc_event_t *event) {
INSIST(client->naccepts == 1);
client->naccepts--;
LOCK(&client->interface->lock);
INSIST(client->interface->ntcpcurrent > 0);
client->interface->ntcpcurrent--;
UNLOCK(&client->interface->lock);
if (client->shuttingdown) {
maybe_free(client);
} else if (nevent->result == ISC_R_SUCCESS) {
@@ -890,8 +942,13 @@ client_newconn(isc_task_t *task, isc_event_t *event) {
* telnetting to port 35 (once per CPU) will
* deny service to legititmate TCP clients.
*/
(void) ns_client_replace(client);
result = ns_client_replace(client, &ns_g_server->tcpquota);
if (result != ISC_R_SUCCESS) {
isc_log_write(ns_g_lctx, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
"no more TCP clients: %s",
isc_result_totext(result));
}
client_read(client);
} else {
/*
@@ -931,6 +988,9 @@ client_accept(ns_client_t *client) {
}
INSIST(client->naccepts == 0);
client->naccepts++;
LOCK(&client->interface->lock);
client->interface->ntcpcurrent++;
UNLOCK(&client->interface->lock);
}
void
@@ -951,27 +1011,54 @@ ns_client_unwait(ns_client_t *client) {
maybe_free(client);
}
isc_result_t
ns_client_replace(ns_client_t *client) {
ns_client_getquota(ns_client_t *client, isc_quota_t *quota) {
isc_result_t result;
/*
* A client can only use one quota at a time.
* If we are already using a quota, release it.
*/
if (client->quota != NULL) {
isc_quota_release(client->quota);
client->quota = NULL;
}
result = isc_quota_reserve(quota);
if (result == ISC_R_SUCCESS) {
client->quota = quota;
} else {
return (result);
}
return (ISC_R_SUCCESS);
}
isc_result_t
ns_client_replace(ns_client_t *client, isc_quota_t *quota) {
isc_result_t result;
CTRACE("replace");
/* XXX Check quota here. */
if (quota != NULL) {
result = ns_client_getquota(client, quota);
if (result != DNS_R_SUCCESS)
return (result);
}
if (TCP_CLIENT(client)) {
result = ns_clientmgr_accepttcp(client->manager, client->tcplistener, 1);
result = ns_clientmgr_accepttcp(client->manager,
1, client->interface);
} else {
result = ns_clientmgr_addtodispatch(client->manager, 1, client->dispatch);
result = ns_clientmgr_addtodispatch(client->manager,
1, client->interface);
}
if (result != ISC_R_SUCCESS)
return (result);
/*
* The new client is ready to listen for new requests, so we
* should refrain from doing so.
* The new client is ready to listen for new requests, therefore we
* should refrain from listening from any more requests when we are
* done with this one.
*/
client->oneshot = ISC_TRUE;
client->mortal = ISC_TRUE;
return (ISC_R_SUCCESS);
}
@@ -1060,7 +1147,7 @@ ns_clientmgr_destroy(ns_clientmgr_t **managerp) {
isc_result_t
ns_clientmgr_addtodispatch(ns_clientmgr_t *manager, unsigned int n,
dns_dispatch_t *dispatch)
ns_interface_t *ifp)
{
isc_result_t result = ISC_R_SUCCESS;
unsigned int i;
@@ -1082,11 +1169,12 @@ ns_clientmgr_addtodispatch(ns_clientmgr_t *manager, unsigned int n,
for (i = 0; i < n; i++) {
client = NULL;
result = client_create(manager, ns_clienttype_basic,
&client);
ifp, &client);
if (result != ISC_R_SUCCESS)
break;
dns_dispatch_attach(dispatch, &client->dispatch);
result = dns_dispatch_addrequest(dispatch, client->task,
dns_dispatch_attach(ifp->udpdispatch, &client->dispatch);
result = dns_dispatch_addrequest(client->dispatch,
client->task,
client_request,
client, &client->dispentry);
if (result != ISC_R_SUCCESS) {
@@ -1112,8 +1200,8 @@ ns_clientmgr_addtodispatch(ns_clientmgr_t *manager, unsigned int n,
}
isc_result_t
ns_clientmgr_accepttcp(ns_clientmgr_t *manager, isc_socket_t *socket,
unsigned int n)
ns_clientmgr_accepttcp(ns_clientmgr_t *manager, unsigned int n,
ns_interface_t *ifp)
{
isc_result_t result = ISC_R_SUCCESS;
unsigned int i;
@@ -1145,11 +1233,12 @@ ns_clientmgr_accepttcp(ns_clientmgr_t *manager, isc_socket_t *socket,
for (i = 0; i < n; i++) {
client = NULL;
result = client_create(manager, ns_clienttype_tcp, &client);
result = client_create(manager, ns_clienttype_tcp,
ifp, &client);
if (result != ISC_R_SUCCESS)
break;
client->attributes |= NS_CLIENTATTR_TCP;
isc_socket_attach(socket, &client->tcplistener);
isc_socket_attach(ifp->tcpsocket, &client->tcplistener);
client_accept(client);
client->manager = manager;
ISC_LIST_APPEND(manager->clients, client, link);