From 05bf4fa9056d85782dad528bba3d0fa90946d4d8 Mon Sep 17 00:00:00 2001
From: Petr Mensik <pemensik@redhat.com>
Date: Wed, 24 Apr 2019 20:09:07 +0200
Subject: [PATCH] 5200. [security] tcp-clients settings could be exceeded in
some cases, which could lead to exhaustion of file descriptors.
(CVE-2018-5743) [GL #615]
---
bin/named/client.c | 428 +++++++++++++++++++------
bin/named/include/named/client.h | 13 +-
bin/named/include/named/interfacemgr.h | 13 +-
bin/named/interfacemgr.c | 9 +-
lib/isc/include/isc/quota.h | 7 +
lib/isc/quota.c | 33 +-
6 files changed, 389 insertions(+), 114 deletions(-)
diff --git a/bin/named/client.c b/bin/named/client.c
index f014b61..0ba383b 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -234,7 +234,9 @@ static void ns_client_dumpmessage(ns_client_t *client, const char *reason);
static isc_result_t get_client(ns_clientmgr_t *manager, ns_interface_t *ifp,
dns_dispatch_t *disp, isc_boolean_t tcp);
static isc_result_t get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp,
- isc_socket_t *socket);
+ isc_socket_t *sock, ns_client_t *oldclient);
+static inline isc_boolean_t
+allowed(isc_netaddr_t *addr, dns_name_t *signer, dns_acl_t *acl);
void
ns_client_recursing(ns_client_t *client) {
@@ -280,6 +282,119 @@ ns_client_settimeout(ns_client_t *client, unsigned int seconds) {
}
}
+/*%
+ * Allocate a reference-counted object that will maintain a single pointer to
+ * the (also reference-counted) TCP client quota, shared between all the
+ * clients processing queries on a single TCP connection, so that all
+ * clients sharing the one socket will together consume only one slot in
+ * the 'tcp-clients' quota.
+ */
+static isc_result_t
+tcpconn_init(ns_client_t *client, isc_boolean_t force) {
+ isc_result_t result;
+ isc_quota_t *quota = NULL;
+ ns_tcpconn_t *tconn = NULL;
+
+ REQUIRE(client->tcpconn == NULL);
+
+ /*
+ * Try to attach to the quota first, so we won't pointlessly
+ * allocate memory for a tcpconn object if we can't get one.
+ */
+ if (force) {
+ result = isc_quota_force(&ns_g_server->tcpquota, "a);
+ } else {
+ result = isc_quota_attach(&ns_g_server->tcpquota, "a);
+ }
+ if (result != ISC_R_SUCCESS) {
+ return (result);
+ }
+
+ /*
+ * A global memory context is used for the allocation as different
+ * client structures may have different memory contexts assigned and a
+ * reference counter allocated here might need to be freed by a
+ * different client. The performance impact caused by memory context
+ * contention here is expected to be negligible, given that this code
+ * is only executed for TCP connections.
+ */
+ tconn = isc_mem_allocate(ns_g_mctx, sizeof(*tconn));
+
+ isc_refcount_init(&tconn->refs, 1);
+ tconn->tcpquota = quota;
+ quota = NULL;
+ tconn->pipelined = ISC_FALSE;
+
+ client->tcpconn = tconn;
+
+ return (ISC_R_SUCCESS);
+}
+
+/*%
+ * Increase the count of client structures sharing the TCP connection
+ * that 'source' is associated with; add a pointer to the same tcpconn
+ * to 'target', thus associating it with the same TCP connection.
+ */
+static void
+tcpconn_attach(ns_client_t *source, ns_client_t *target) {
+ int refs;
+
+ REQUIRE(source->tcpconn != NULL);
+ REQUIRE(target->tcpconn == NULL);
+ REQUIRE(source->tcpconn->pipelined);
+
+ isc_refcount_increment(&source->tcpconn->refs, &refs);
+ INSIST(refs > 1);
+ target->tcpconn = source->tcpconn;
+}
+
+/*%
+ * Decrease the count of client structures sharing the TCP connection that
+ * 'client' is associated with. If this is the last client using this TCP
+ * connection, we detach from the TCP quota and free the tcpconn
+ * object. Either way, client->tcpconn is set to NULL.
+ */
+static void
+tcpconn_detach(ns_client_t *client) {
+ ns_tcpconn_t *tconn = NULL;
+ int refs;
+
+ REQUIRE(client->tcpconn != NULL);
+
+ tconn = client->tcpconn;
+ client->tcpconn = NULL;
+
+ isc_refcount_decrement(&tconn->refs, &refs);
+ if (refs == 0) {
+ isc_quota_detach(&tconn->tcpquota);
+ isc_mem_free(ns_g_mctx, tconn);
+ }
+}
+
+/*%
+ * Mark a client as active and increment the interface's 'ntcpactive'
+ * counter, as a signal that there is at least one client servicing
+ * TCP queries for the interface. If we reach the TCP client quota at
+ * some point, this will be used to determine whether a quota overrun
+ * should be permitted.
+ *
+ * Marking the client active with the 'tcpactive' flag ensures proper
+ * accounting, by preventing us from incrementing or decrementing
+ * 'ntcpactive' more than once per client.
+ */
+static void
+mark_tcp_active(ns_client_t *client, isc_boolean_t active) {
+ if (active && !client->tcpactive) {
+ isc_atomic_xadd(&client->interface->ntcpactive, 1);
+ client->tcpactive = active;
+ } else if (!active && client->tcpactive) {
+ uint32_t old =
+ isc_atomic_xadd(&client->interface->ntcpactive, -1);
+ INSIST(old > 0);
+ client->tcpactive = active;
+ }
+}
+
/*%
* Check for a deactivation or shutdown request and take appropriate
* action. Returns ISC_TRUE if either is in progress; in this case
@@ -369,7 +484,8 @@ exit_check(ns_client_t *client) {
INSIST(client->recursionquota == NULL);
if (NS_CLIENTSTATE_READING == client->newstate) {
- if (!client->pipelined) {
+ INSIST(client->tcpconn != NULL);
+ if (!client->tcpconn->pipelined) {
client_read(client);
client->newstate = NS_CLIENTSTATE_MAX;
return (ISC_TRUE); /* We're done. */
@@ -386,10 +502,13 @@ exit_check(ns_client_t *client) {
*/
INSIST(client->recursionquota == NULL);
INSIST(client->newstate <= NS_CLIENTSTATE_READY);
- if (client->nreads > 0)
+
+ if (client->nreads > 0) {
dns_tcpmsg_cancelread(&client->tcpmsg);
- if (! client->nreads == 0) {
- /* Still waiting for read cancel completion. */
+ }
+
+ /* Still waiting for read cancel completion. */
+ if (client->nreads > 0) {
return (ISC_TRUE);
}
@@ -397,14 +516,49 @@ exit_check(ns_client_t *client) {
dns_tcpmsg_invalidate(&client->tcpmsg);
client->tcpmsg_valid = ISC_FALSE;
}
+
+ /*
+ * Soon the client will be ready to accept a new TCP
+ * connection or UDP request, but we may have enough
+ * clients doing that already. Check whether this client
+ * needs to remain active and allow it go inactive if
+ * not.
+ *
+ * UDP clients always go inactive at this point, but a TCP
+ * client may need to stay active and return to READY
+ * state if no other clients are available to listen
+ * for TCP requests on this interface.
+ *
+ * Regardless, if we're going to FREED state, that means
+ * the system is shutting down and we don't need to
+ * retain clients.
+ */
+ if (client->mortal && TCP_CLIENT(client) &&
+ client->newstate != NS_CLIENTSTATE_FREED &&
+ !ns_g_clienttest &&
+ isc_atomic_xadd(&client->interface->ntcpaccepting, 0) == 0)
+ {
+ /* Nobody else is accepting */
+ client->mortal = ISC_FALSE;
+ client->newstate = NS_CLIENTSTATE_READY;
+ }
+
+ /*
+ * Detach from TCP connection and TCP client quota,
+ * if appropriate. If this is the last reference to
+ * the TCP connection in our pipeline group, the
+ * TCP quota slot will be released.
+ */
+ if (client->tcpconn) {
+ tcpconn_detach(client);
+ }
+
if (client->tcpsocket != NULL) {
CTRACE("closetcp");
isc_socket_detach(&client->tcpsocket);
+ mark_tcp_active(client, ISC_FALSE);
}
- if (client->tcpquota != NULL)
- isc_quota_detach(&client->tcpquota);
-
if (client->timerset) {
(void)isc_timer_reset(client->timer,
isc_timertype_inactive,
@@ -412,45 +566,26 @@ exit_check(ns_client_t *client) {
client->timerset = ISC_FALSE;
}
- client->pipelined = ISC_FALSE;
-
client->peeraddr_valid = ISC_FALSE;
client->state = NS_CLIENTSTATE_READY;
- INSIST(client->recursionquota == NULL);
-
- /*
- * Now the client is ready to accept a new TCP connection
- * or UDP request, but we may have enough clients doing
- * that already. Check whether this client needs to remain
- * active and force it to go inactive if not.
- *
- * UDP clients go inactive at this point, but TCP clients
- * may remain active if we have fewer active TCP client
- * objects than desired due to an earlier quota exhaustion.
- */
- if (client->mortal && TCP_CLIENT(client) && !ns_g_clienttest) {
- LOCK(&client->interface->lock);
- if (client->interface->ntcpcurrent <
- client->interface->ntcptarget)
- client->mortal = ISC_FALSE;
- UNLOCK(&client->interface->lock);
- }
/*
* We don't need the client; send it to the inactive
* queue for recycling.
*/
if (client->mortal) {
- if (client->newstate > NS_CLIENTSTATE_INACTIVE)
+ if (client->newstate > NS_CLIENTSTATE_INACTIVE) {
client->newstate = NS_CLIENTSTATE_INACTIVE;
+ }
}
if (NS_CLIENTSTATE_READY == client->newstate) {
if (TCP_CLIENT(client)) {
client_accept(client);
- } else
+ } else {
client_udprecv(client);
+ }
client->newstate = NS_CLIENTSTATE_MAX;
return (ISC_TRUE);
}
@@ -462,41 +597,51 @@ exit_check(ns_client_t *client) {
/*
* We are trying to enter the inactive state.
*/
- if (client->naccepts > 0)
+ if (client->naccepts > 0) {
isc_socket_cancel(client->tcplistener, client->task,
ISC_SOCKCANCEL_ACCEPT);
+ }
/* Still waiting for accept cancel completion. */
- if (! (client->naccepts == 0))
+ if (client->naccepts > 0) {
return (ISC_TRUE);
+ }
/* Accept cancel is complete. */
- if (client->nrecvs > 0)
+ if (client->nrecvs > 0) {
isc_socket_cancel(client->udpsocket, client->task,
ISC_SOCKCANCEL_RECV);
+ }
/* Still waiting for recv cancel completion. */
- if (! (client->nrecvs == 0))
+ if (client->nrecvs > 0) {
return (ISC_TRUE);
+ }
/* Still waiting for control event to be delivered */
- if (client->nctls > 0)
+ if (client->nctls > 0) {
return (ISC_TRUE);
-
- /* Deactivate the client. */
- if (client->interface)
- ns_interface_detach(&client->interface);
+ }
INSIST(client->naccepts == 0);
INSIST(client->recursionquota == NULL);
- if (client->tcplistener != NULL)
+ if (client->tcplistener != NULL) {
isc_socket_detach(&client->tcplistener);
+ mark_tcp_active(client, ISC_FALSE);
+ }
- if (client->udpsocket != NULL)
+ if (client->udpsocket != NULL) {
isc_socket_detach(&client->udpsocket);
+ }
- if (client->dispatch != NULL)
+ /* Deactivate the client. */
+ if (client->interface != NULL) {
+ ns_interface_detach(&client->interface);
+ }
+
+ if (client->dispatch != NULL) {
dns_dispatch_detach(&client->dispatch);
+ }
client->attributes = 0;
client->mortal = ISC_FALSE;
@@ -515,10 +660,13 @@ exit_check(ns_client_t *client) {
client->newstate = NS_CLIENTSTATE_MAX;
if (!ns_g_clienttest && manager != NULL &&
!manager->exiting)
+ {
ISC_QUEUE_PUSH(manager->inactive, client,
ilink);
- if (client->needshutdown)
+ }
+ if (client->needshutdown) {
isc_task_shutdown(client->task);
+ }
return (ISC_TRUE);
}
}
@@ -613,7 +761,7 @@ client_start(isc_task_t *task, isc_event_t *event) {
return;
if (TCP_CLIENT(client)) {
- if (client->pipelined) {
+ if (client->tcpconn != NULL) {
client_read(client);
} else {
client_accept(client);
@@ -623,7 +771,6 @@ client_start(isc_task_t *task, isc_event_t *event) {
}
}
-
/*%
* The client's task has received a shutdown event.
*/
@@ -1511,6 +1658,7 @@ client_request(isc_task_t *task, isc_event_t *event) {
client->nrecvs--;
} else {
INSIST(TCP_CLIENT(client));
+ INSIST(client->tcpconn != NULL);
REQUIRE(event->ev_type == DNS_EVENT_TCPMSG);
REQUIRE(event->ev_sender == &client->tcpmsg);
buffer = &client->tcpmsg.buffer;
@@ -1653,18 +1801,27 @@ client_request(isc_task_t *task, isc_event_t *event) {
/*
* Pipeline TCP query processing.
*/
- if (client->message->opcode != dns_opcode_query)
- client->pipelined = ISC_FALSE;
- if (TCP_CLIENT(client) && client->pipelined) {
- result = isc_quota_reserve(&ns_g_server->tcpquota);
- if (result == ISC_R_SUCCESS)
- result = ns_client_replace(client);
+ if (TCP_CLIENT(client) &&
+ client->message->opcode != dns_opcode_query)
+ {
+ client->tcpconn->pipelined = ISC_FALSE;
+ }
+ if (TCP_CLIENT(client) && client->tcpconn->pipelined) {
+ /*
+ * We're pipelining. Replace the client; the
+ * replacement can read the TCP socket looking
+ * for new messages and this one can process the
+ * current message asynchronously.
+ *
+ * There will now be at least three clients using this
+ * TCP socket - one accepting new connections,
+ * one reading an existing connection to get new
+ * messages, and one answering the message already
+ * received.
+ */
+ result = ns_client_replace(client);
if (result != ISC_R_SUCCESS) {
- ns_client_log(client, NS_LOGCATEGORY_CLIENT,
- NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
- "no more TCP clients(read): %s",
- isc_result_totext(result));
- client->pipelined = ISC_FALSE;
+ client->tcpconn->pipelined = ISC_FALSE;
}
}
@@ -2168,8 +2325,7 @@ client_create(ns_clientmgr_t *manager, ns_client_t **clientp) {
client->signer = NULL;
dns_name_init(&client->signername, NULL);
client->mortal = ISC_FALSE;
- client->pipelined = ISC_FALSE;
- client->tcpquota = NULL;
+ client->tcpconn = NULL;
client->recursionquota = NULL;
client->interface = NULL;
client->peeraddr_valid = ISC_FALSE;
@@ -2177,6 +2333,7 @@ client_create(ns_clientmgr_t *manager, ns_client_t **clientp) {
client->filter_aaaa = dns_v4_aaaa_ok;
#endif
client->needshutdown = ns_g_clienttest;
+ client->tcpactive = ISC_FALSE;
ISC_EVENT_INIT(&client->ctlevent, sizeof(client->ctlevent), 0, NULL,
NS_EVENT_CLIENTCONTROL, client_start, client, client,
@@ -2269,9 +2426,10 @@ client_read(ns_client_t *client) {
static void
client_newconn(isc_task_t *task, isc_event_t *event) {
+ isc_result_t result;
ns_client_t *client = event->ev_arg;
isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event;
- isc_result_t result;
+ uint32_t old;
REQUIRE(event->ev_type == ISC_SOCKEVENT_NEWCONN);
REQUIRE(NS_CLIENT_VALID(client));
@@ -2281,13 +2439,18 @@ client_newconn(isc_task_t *task, isc_event_t *event) {
INSIST(client->state == NS_CLIENTSTATE_READY);
+ /*
+ * The accept() was successful and we're now establishing a new
+ * connection. We need to make note of it in the client and
+ * interface objects so client objects can do the right thing
+ * when going inactive in exit_check() (see comments in
+ * client_accept() for details).
+ */
INSIST(client->naccepts == 1);
client->naccepts--;
- LOCK(&client->interface->lock);
- INSIST(client->interface->ntcpcurrent > 0);
- client->interface->ntcpcurrent--;
- UNLOCK(&client->interface->lock);
+ old = isc_atomic_xadd(&client->interface->ntcpaccepting, -1);
+ INSIST(old > 0);
/*
* We must take ownership of the new socket before the exit
@@ -2320,6 +2483,7 @@ client_newconn(isc_task_t *task, isc_event_t *event) {
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"accept failed: %s",
isc_result_totext(nevent->result));
+ tcpconn_detach(client);
}
if (exit_check(client))
@@ -2357,20 +2521,13 @@ client_newconn(isc_task_t *task, isc_event_t *event) {
* telnetting to port 53 (once per CPU) will
* deny service to legitimate TCP clients.
*/
- client->pipelined = ISC_FALSE;
- result = isc_quota_attach(&ns_g_server->tcpquota,
- &client->tcpquota);
- if (result == ISC_R_SUCCESS)
- result = ns_client_replace(client);
- if (result != ISC_R_SUCCESS) {
- ns_client_log(client, NS_LOGCATEGORY_CLIENT,
- NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
- "no more TCP clients(accept): %s",
- isc_result_totext(result));
- } else if (ns_g_server->keepresporder == NULL ||
- !allowed(&netaddr, NULL, NULL, 0, NULL,
- ns_g_server->keepresporder)) {
- client->pipelined = ISC_TRUE;
+ result = ns_client_replace(client);
+ if (result == ISC_R_SUCCESS &&
+ (ns_g_server->keepresporder == NULL ||
+ !allowed(&netaddr, NULL,
+ ns_g_server->keepresporder)))
+ {
+ client->tcpconn->pipelined = ISC_TRUE;
}
client_read(client);
@@ -2386,12 +2543,66 @@ client_accept(ns_client_t *client) {
CTRACE("accept");
+ /*
+ * Set up a new TCP connection. This means try to attach to the
+ * TCP client quota (tcp-clients), but fail if we're over quota.
+ */
+ result = tcpconn_init(client, ISC_FALSE);
+ if (result != ISC_R_SUCCESS) {
+ isc_boolean_t exit;
+
+ ns_client_log(client, NS_LOGCATEGORY_CLIENT,
+ NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
+ "TCP client quota reached: %s",
+ isc_result_totext(result));
+
+ /*
+ * We have exceeded the system-wide TCP client quota. But,
+ * we can't just block this accept in all cases, because if
+ * we did, a heavy TCP load on other interfaces might cause
+ * this interface to be starved, with no clients able to
+ * accept new connections.
+ *
+ * So, we check here to see if any other clients are
+ * already servicing TCP queries on this interface (whether
+ * accepting, reading, or processing). If we find that at
+ * least one client other than this one is active, then
+ * it's okay *not* to call accept - we can let this
+ * client go inactive and another will take over when it's
+ * done.
+ *
+ * If there aren't enough active clients on the interface,
+ * then we can be a little bit flexible about the quota.
+ * We'll allow *one* extra client through to ensure we're
+ * listening on every interface; we do this by setting the
+ * 'force' option to tcpconn_init().
+ *
+ * (Note: In practice this means that the real TCP client
+ * quota is tcp-clients plus the number of listening
+ * interfaces plus 1.)
+ */
+ exit = (isc_atomic_xadd(&client->interface->ntcpactive, 0) >
+ (client->tcpactive ? 1 : 0));
+ if (exit) {
+ client->newstate = NS_CLIENTSTATE_INACTIVE;
+ (void)exit_check(client);
+ return;
+ }
+
+ result = tcpconn_init(client, ISC_TRUE);
+ RUNTIME_CHECK(result == ISC_R_SUCCESS);
+ }
+
+ /*
+ * If this client was set up using get_client() or get_worker(),
+ * then TCP is already marked active. However, if it was restarted
+ * from exit_check(), it might not be, so we take care of it now.
+ */
+ mark_tcp_active(client, ISC_TRUE);
+
result = isc_socket_accept(client->tcplistener, client->task,
client_newconn, client);
if (result != ISC_R_SUCCESS) {
- UNEXPECTED_ERROR(__FILE__, __LINE__,
- "isc_socket_accept() failed: %s",
- isc_result_totext(result));
/*
* XXXRTH What should we do? We're trying to accept but
* it didn't work. If we just give up, then TCP
@@ -2399,13 +2610,37 @@ client_accept(ns_client_t *client) {
*
* For now, we just go idle.
*/
+ UNEXPECTED_ERROR(__FILE__, __LINE__,
+ "isc_socket_accept() failed: %s",
+ isc_result_totext(result));
+
+ tcpconn_detach(client);
+ mark_tcp_active(client, ISC_FALSE);
return;
}
+
+ /*
+ * The client's 'naccepts' counter indicates that this client has
+ * called accept() and is waiting for a new connection. It should
+ * never exceed 1.
+ */
INSIST(client->naccepts == 0);
client->naccepts++;
- LOCK(&client->interface->lock);
- client->interface->ntcpcurrent++;
- UNLOCK(&client->interface->lock);
+
+ /*
+ * The interface's 'ntcpaccepting' counter is incremented when
+ * any client calls accept(), and decremented in client_newconn()
+ * once the connection is established.
+ *
+ * When the client object is shutting down after handling a TCP
+ * request (see exit_check()), if this value is at least one, that
+ * means another client has called accept() and is waiting to
+ * establish the next connection. That means the client may be
+ * be free to become inactive; otherwise it may need to start
+ * listening for connections itself to prevent the interface
+ * going dead.
+ */
+ isc_atomic_xadd(&client->interface->ntcpaccepting, 1);
}
static void
@@ -2476,15 +2711,17 @@ ns_client_replace(ns_client_t *client) {
REQUIRE(client->manager != NULL);
tcp = TCP_CLIENT(client);
- if (tcp && client->pipelined) {
+ if (tcp && client->tcpconn != NULL && client->tcpconn->pipelined) {
result = get_worker(client->manager, client->interface,
- client->tcpsocket);
+ client->tcpsocket, client);
} else {
result = get_client(client->manager, client->interface,
client->dispatch, tcp);
+
}
- if (result != ISC_R_SUCCESS)
+ if (result != ISC_R_SUCCESS) {
return (result);
+ }
/*
* The responsibility for listening for new requests is hereby
@@ -2668,9 +2905,12 @@ get_client(ns_clientmgr_t *manager, ns_interface_t *ifp,
INSIST(client->recursionquota == NULL);
if (tcp) {
+ mark_tcp_active(client, ISC_TRUE);
+
client->attributes |= NS_CLIENTATTR_TCP;
isc_socket_attach(ifp->tcpsocket,
&client->tcplistener);
+
} else {
isc_socket_t *sock;
@@ -2688,7 +2928,8 @@ get_client(ns_clientmgr_t *manager, ns_interface_t *ifp,
}
static isc_result_t
-get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp, isc_socket_t *socket)
+get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp, isc_socket_t *sock,
+ ns_client_t *oldclient)
{
isc_result_t result = ISC_R_SUCCESS;
isc_event_t *ev;
@@ -2696,6 +2937,7 @@ get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp, isc_socket_t *socket)
MTRACE("get worker");
REQUIRE(manager != NULL);
+ REQUIRE(oldclient != NULL);
if (manager->exiting)
return (ISC_R_SHUTTINGDOWN);
@@ -2728,15 +2970,15 @@ get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp, isc_socket_t *socket)
ns_interface_attach(ifp, &client->interface);
client->newstate = client->state = NS_CLIENTSTATE_WORKING;
INSIST(client->recursionquota == NULL);
- client->tcpquota = &ns_g_server->tcpquota;
-
- client->dscp = ifp->dscp;
client->attributes |= NS_CLIENTATTR_TCP;
- client->pipelined = ISC_TRUE;
+ client->mortal = ISC_TRUE;
+
+ tcpconn_attach(oldclient, client);
+ mark_tcp_active(client, ISC_TRUE);
isc_socket_attach(ifp->tcpsocket, &client->tcplistener);
- isc_socket_attach(socket, &client->tcpsocket);
+ isc_socket_attach(sock, &client->tcpsocket);
isc_socket_setname(client->tcpsocket, "worker-tcp", NULL);
(void)isc_socket_getpeername(client->tcpsocket, &client->peeraddr);
client->peeraddr_valid = ISC_TRUE;
diff --git a/bin/named/include/named/client.h b/bin/named/include/named/client.h
index bf4d201..ef55a7a 100644
--- a/bin/named/include/named/client.h
+++ b/bin/named/include/named/client.h
@@ -15,8 +15,6 @@
* PERFORMANCE OF THIS SOFTWARE.
*/
-/* $Id$ */
-
#ifndef NAMED_CLIENT_H
#define NAMED_CLIENT_H 1
@@ -83,6 +81,13 @@
*** Types
***/
+/*% reference-counted TCP connection object */
+typedef struct ns_tcpconn {
+ isc_refcount_t refs;
+ isc_quota_t *tcpquota;
+ isc_boolean_t pipelined;
+} ns_tcpconn_t;
+
/*% nameserver client structure */
struct ns_client {
unsigned int magic;
@@ -133,8 +138,8 @@ struct ns_client {
dns_name_t signername; /*%< [T]SIG key name */
dns_name_t * signer; /*%< NULL if not valid sig */
isc_boolean_t mortal; /*%< Die after handling request */
- isc_boolean_t pipelined; /*%< TCP queries not in sequence */
- isc_quota_t *tcpquota;
+ isc_boolean_t tcpactive;
+ ns_tcpconn_t *tcpconn;
isc_quota_t *recursionquota;
ns_interface_t *interface;
isc_sockaddr_t peeraddr;
diff --git a/bin/named/include/named/interfacemgr.h b/bin/named/include/named/interfacemgr.h
index 380dbed..a342866 100644
--- a/bin/named/include/named/interfacemgr.h
+++ b/bin/named/include/named/interfacemgr.h
@@ -15,8 +15,6 @@
* PERFORMANCE OF THIS SOFTWARE.
*/
-/* $Id: interfacemgr.h,v 1.35 2011/07/28 23:47:58 tbox Exp $ */
-
#ifndef NAMED_INTERFACEMGR_H
#define NAMED_INTERFACEMGR_H 1
@@ -80,9 +78,14 @@ struct ns_interface {
dns_dispatch_t * udpdispatch[MAX_UDP_DISPATCH];
/*%< UDP dispatchers. */
isc_socket_t * tcpsocket; /*%< TCP socket. */
- int ntcptarget; /*%< Desired number of concurrent
- TCP accepts */
- int ntcpcurrent; /*%< Current ditto, locked */
+ int32_t ntcpaccepting; /*%< Number of clients
+ ready to accept new
+ TCP connections on this
+ interface */
+ int32_t ntcpactive; /*%< Number of clients
+ servicing TCP queries
+ (whether accepting or
+ connected) */
int nudpdispatch; /*%< Number of UDP dispatches */
ns_clientmgr_t * clientmgr; /*%< Client manager. */
ISC_LINK(ns_interface_t) link;
diff --git a/bin/named/interfacemgr.c b/bin/named/interfacemgr.c
index 4aee47a..ebec0c4 100644
--- a/bin/named/interfacemgr.c
+++ b/bin/named/interfacemgr.c
@@ -380,8 +380,9 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
* connections will be handled in parallel even though there is
* only one client initially.
*/
- ifp->ntcptarget = 1;
- ifp->ntcpcurrent = 0;
+ ifp->ntcpaccepting = 0;
+ ifp->ntcpactive = 0;
+
ifp->nudpdispatch = 0;
ISC_LINK_INIT(ifp, link);
@@ -510,9 +511,7 @@ ns_interface_accepttcp(ns_interface_t *ifp) {
*/
(void)isc_socket_filter(ifp->tcpsocket, "dataready");
- result = ns_clientmgr_createclients(ifp->clientmgr,
- ifp->ntcptarget, ifp,
- ISC_TRUE);
+ result = ns_clientmgr_createclients(ifp->clientmgr, 1, ifp, ISC_TRUE);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"TCP ns_clientmgr_createclients(): %s",
diff --git a/lib/isc/include/isc/quota.h b/lib/isc/include/isc/quota.h
index 7b0d0d9..bb1a927 100644
--- a/lib/isc/include/isc/quota.h
+++ b/lib/isc/include/isc/quota.h
@@ -107,6 +107,13 @@ isc_quota_attach(isc_quota_t *quota, isc_quota_t **p);
* quota if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA).
*/
+isc_result_t
+isc_quota_force(isc_quota_t *quota, isc_quota_t **p);
+/*%<
+ * Like isc_quota_attach, but will attach '*p' to the quota
+ * even if the hard quota has been exceeded.
+ */
+
void
isc_quota_detach(isc_quota_t **p);
/*%<
diff --git a/lib/isc/quota.c b/lib/isc/quota.c
index 5e5c50c..ca4c478 100644
--- a/lib/isc/quota.c
+++ b/lib/isc/quota.c
@@ -81,20 +81,39 @@ isc_quota_release(isc_quota_t *quota) {
UNLOCK("a->lock);
}
-isc_result_t
-isc_quota_attach(isc_quota_t *quota, isc_quota_t **p)
-{
+static isc_result_t
+doattach(isc_quota_t *quota, isc_quota_t **p, isc_boolean_t force) {
isc_result_t result;
- INSIST(p != NULL && *p == NULL);
+ REQUIRE(p != NULL && *p == NULL);
+
result = isc_quota_reserve(quota);
- if (result == ISC_R_SUCCESS || result == ISC_R_SOFTQUOTA)
+ if (result == ISC_R_SUCCESS || result == ISC_R_SOFTQUOTA) {
+ *p = quota;
+ } else if (result == ISC_R_QUOTA && force) {
+ /* attach anyway */
+ LOCK("a->lock);
+ quota->used++;
+ UNLOCK("a->lock);
+
*p = quota;
+ result = ISC_R_SUCCESS;
+ }
+
return (result);
}
+isc_result_t
+isc_quota_attach(isc_quota_t *quota, isc_quota_t **p) {
+ return (doattach(quota, p, ISC_FALSE));
+}
+
+isc_result_t
+isc_quota_force(isc_quota_t *quota, isc_quota_t **p) {
+ return (doattach(quota, p, ISC_TRUE));
+}
+
void
-isc_quota_detach(isc_quota_t **p)
-{
+isc_quota_detach(isc_quota_t **p) {
INSIST(p != NULL && *p != NULL);
isc_quota_release(*p);
*p = NULL;
--
2.20.1