client quotas; added reference counting to ns_interface_t

and ns_interfacemgr_t so that they can safely hold quota information

bin/named/client.c

@@ -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) {
+	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));
@@ -875,6 +922,11 @@ 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
@@ -953,25 +1013,52 @@ ns_client_unwait(ns_client_t *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);

bin/named/include/named/client.h

@@ -21,6 +21,7 @@
 #include <isc/types.h>
 #include <isc/stdtime.h>
 #include <isc/buffer.h>
+#include <isc/quota.h>
 
 #include <dns/name.h>
 #include <dns/types.h>
@@ -69,7 +70,9 @@ struct ns_client {
 	isc_stdtime_t			now;
 	dns_name_t			signername; /* [T]SIG key name */
 	dns_name_t *			signer; /* NULL if not valid sig */
-	isc_boolean_t			oneshot;
+	isc_boolean_t			mortal; /* Die after handling request. */
+	isc_quota_t			*quota;
+	ns_interface_t			*interface;
 	ISC_LINK(struct ns_client)	link;
 };
 
@@ -118,7 +121,11 @@ ns_client_unwait(ns_client_t *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
+ns_client_replace(ns_client_t *client, isc_quota_t *quota);
 /*
  * Try to replace the current client with a new one, so that the
  * current one can go off and do some lengthy work without
@@ -136,11 +143,19 @@ 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);
+/*
+ * Create up to 'n' UDP clients listening for requests through the
+ * dispatch of interface 'ifp'.
+ */
        
 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);
+/*
+ * Create up to 'n' TCP clients accepting requests on the
+ * socket of interface 'ifp'.
+ */
 
 isc_sockaddr_t *
 ns_client_getsockaddr(ns_client_t *client);

bin/named/include/named/interfacemgr.h

@@ -56,15 +56,49 @@
 
 #include <named/types.h>
 
+/***
+ *** Types
+ ***/
+
+#define IFACE_MAGIC		0x493A2D29U	/* I:-). */	
+#define NS_INTERFACE_VALID(t)	((t) != NULL && (t)->magic == IFACE_MAGIC)
+
+struct ns_interface {
+	unsigned int		magic;		/* Magic number. */
+	ns_interfacemgr_t *	mgr;		/* Interface manager. */
+	isc_mutex_t		lock;
+	int			references;	/* Locked */
+	unsigned int		generation;     /* Generation number. */
+	isc_sockaddr_t		addr;           /* Address and port. */
+	isc_socket_t *		udpsocket; 	/* UDP socket. */
+	dns_dispatch_t *	udpdispatch;	/* UDP dispatcher. */
+	isc_socket_t *		tcpsocket;	/* TCP socket. */
+	isc_task_t *		task;
+	int			ntcptarget;	/* Desired # of TCP accepts */
+	int			ntcpcurrent;	/* Current ditto, locked */
+	ISC_LINK(ns_interface_t) link;
+};
+
 /***
  *** Functions
  ***/
 
+
 isc_result_t
 ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 		       isc_socketmgr_t *socketmgr, ns_clientmgr_t *clientmgr,
 		       ns_interfacemgr_t **mgrp);
 
+void
+ns_interfacemgr_attach(ns_interfacemgr_t *source,
+		       ns_interfacemgr_t **target);
+
+void 
+ns_interfacemgr_detach(ns_interfacemgr_t **targetp);
+
+void
+ns_interfacemgr_shutdown(ns_interfacemgr_t *mgr);
+
 void
 ns_interfacemgr_scan(ns_interfacemgr_t *mgr);
 /*
@@ -79,10 +113,12 @@ ns_interfacemgr_scan(ns_interfacemgr_t *mgr);
  * in named.conf.
  */
 
+
 void
-ns_interfacemgr_destroy(ns_interfacemgr_t **mgrp);
-/*
- * Destroy the interface manager.  
- */
+ns_interface_attach(ns_interface_t *source,
+		    ns_interface_t **target);
+
+void 
+ns_interface_detach(ns_interface_t **targetp);
 
 #endif /* NS_INTERFACEMGR_H */

bin/named/include/named/server.h

@@ -18,8 +18,9 @@
 #ifndef NS_SERVER_H
 #define NS_SERVER_H 1
 
-#include <isc/types.h>
 #include <isc/log.h>
+#include <isc/types.h>
+#include <isc/quota.h>
 
 #include <dns/types.h>
 
@@ -37,6 +38,9 @@ struct ns_server {
 	dns_acl_t *		queryacl;
 	dns_acl_t *		recursionacl;
 	dns_acl_t *		transferacl;
+	isc_quota_t		xfroutquota;
+	isc_quota_t		tcpquota;
+	isc_quota_t		recursionquota;
 
 	/* Server data structures. */
 	dns_viewlist_t		viewlist;

bin/named/include/named/types.h

@@ -26,6 +26,7 @@ typedef struct ns_client		ns_client_t;
 typedef struct ns_clientmgr		ns_clientmgr_t;
 typedef struct ns_query			ns_query_t;
 typedef struct ns_server 		ns_server_t;
+typedef struct ns_interface 		ns_interface_t;
 typedef struct ns_interfacemgr		ns_interfacemgr_t;
 
 #endif /* NS_TYPES_H */

bin/named/interfacemgr.c

@@ -31,6 +31,7 @@
 #include <isc/types.h>
 #include <isc/net.h>
 #include <isc/interfaceiter.h>
+#include <isc/util.h>
 
 #include <dns/dispatch.h>
 
@@ -39,13 +40,13 @@
 #include <named/log.h>
 #include <named/interfacemgr.h>
 
-typedef struct ns_interface ns_interface_t;
-
 #define IFMGR_MAGIC		0x49464D47U	/* IFMG. */	
-#define VALID_IFMGR(t)		((t) != NULL && (t)->magic == IFMGR_MAGIC)
+#define NS_INTERFACEMGR_VALID(t) ((t) != NULL && (t)->magic == IFMGR_MAGIC)
 
 struct ns_interfacemgr {
 	unsigned int		magic;		/* Magic number. */
+	int			references;
+	isc_mutex_t		lock;
 	isc_mem_t *		mctx;		/* Memory context. */
 	isc_taskmgr_t *		taskmgr;	/* Task manager. */
 	isc_socketmgr_t *	socketmgr;	/* Socket manager. */
@@ -54,26 +55,14 @@ struct ns_interfacemgr {
 	ISC_LIST(ns_interface_t) interfaces;	/* List of interfaces. */
 };
 
-#define IFACE_MAGIC		0x493A2D29U	/* I:-). */	
-#define VALID_IFACE(t)		((t) != NULL && (t)->magic == IFACE_MAGIC)
-
-struct ns_interface {
-	unsigned int		magic;		/* Magic number. */
-	ns_interfacemgr_t *	mgr;		/* Interface manager. */
-	unsigned int		generation;     /* Generation number. */
-	isc_sockaddr_t		addr;           /* Address and port. */
-	isc_socket_t *		udpsocket; 	/* UDP socket. */
-	dns_dispatch_t *	udpdispatch;	/* UDP dispatcher. */
-	isc_socket_t *		tcpsocket;	/* TCP socket. */
-	isc_task_t *		task;
-	ISC_LINK(ns_interface_t) link;
-};
+static void purge_old_interfaces(ns_interfacemgr_t *mgr);
 
 isc_result_t
 ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 		       isc_socketmgr_t *socketmgr, ns_clientmgr_t *clientmgr,
 		       ns_interfacemgr_t **mgrp)
 {
+	isc_result_t result;
 	ns_interfacemgr_t *mgr;
 
 	REQUIRE(mctx != NULL);
@@ -84,6 +73,12 @@ ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 	if (mgr == NULL)
 		return (DNS_R_NOMEMORY);
 
+	result = isc_mutex_init(&mgr->lock);
+	if (result != ISC_R_SUCCESS) {
+		isc_mem_put(mctx, mgr, sizeof(*mgr));
+		return (result);
+	}
+
 	mgr->mctx = mctx;
 	mgr->taskmgr = taskmgr;
 	mgr->socketmgr = socketmgr;
@@ -91,25 +86,88 @@ ns_interfacemgr_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr,
 	mgr->generation = 1;
 	ISC_LIST_INIT(mgr->interfaces);
 
+	mgr->references = 1;
 	mgr->magic = IFMGR_MAGIC;
 	*mgrp = mgr;
 	return (DNS_R_SUCCESS);
 }
 
+static void
+ns_interfacemgr_destroy(ns_interfacemgr_t *mgr)
+{
+	REQUIRE(NS_INTERFACEMGR_VALID(mgr));
+	isc_mutex_destroy(&mgr->lock);
+	mgr->magic = 0;
+	isc_mem_put(mgr->mctx, mgr, sizeof *mgr);
+}
+
+void
+ns_interfacemgr_attach(ns_interfacemgr_t *source,
+		       ns_interfacemgr_t **target)
+{
+	REQUIRE(NS_INTERFACEMGR_VALID(source));
+	LOCK(&source->lock);
+	INSIST(source->references > 0);
+	source->references++;
+	UNLOCK(&source->lock);
+	*target = source;
+}
+
+void 
+ns_interfacemgr_detach(ns_interfacemgr_t **targetp)
+{
+	isc_result_t need_destroy = ISC_FALSE;
+	ns_interfacemgr_t *target = *targetp;
+	REQUIRE(target != NULL);
+	REQUIRE(NS_INTERFACEMGR_VALID(target));
+	LOCK(&target->lock);
+	REQUIRE(target->references > 0);
+	target->references--;
+	if (target->references == 0)
+		need_destroy = ISC_TRUE;
+	UNLOCK(&target->lock);
+	if (need_destroy)
+		ns_interfacemgr_destroy(target);
+	*targetp = NULL;
+}
+
+void
+ns_interfacemgr_shutdown(ns_interfacemgr_t *mgr)
+{
+	REQUIRE(NS_INTERFACEMGR_VALID(mgr));
+
+	LOCK(&mgr->lock);
+	/*
+	 * Shut down and detach all interfaces.
+	 * By incrementing the generation count, we make purge_old_interfaces()
+	 * consider all interfaces "old".
+	 */
+	mgr->generation++;
+	purge_old_interfaces(mgr);
+	INSIST(ISC_LIST_EMPTY(mgr->interfaces));
+	UNLOCK(&mgr->lock);	
+}
+
+
 static isc_result_t
 ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
-		    isc_boolean_t udp_only, ns_interface_t **ifpret) {
+		    ns_interface_t **ifpret)
+{
         ns_interface_t *ifp;
 	isc_result_t result;
 	
-	REQUIRE(VALID_IFMGR(mgr));
+	REQUIRE(NS_INTERFACEMGR_VALID(mgr));
 	ifp = isc_mem_get(mgr->mctx, sizeof(*ifp));
 	if (ifp == NULL)
 		return (DNS_R_NOMEMORY);
-	ifp->mgr = mgr;
+	ifp->mgr = NULL;
 	ifp->generation = mgr->generation;
 	ifp->addr = *addr;
 
+	result = isc_mutex_init(&ifp->lock);
+	if (result != ISC_R_SUCCESS)
+		goto lock_create_failure;
+
 	/*
 	 * Create a task.
 	 */
@@ -122,12 +180,42 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
 		goto task_create_failure;
 	}
 
+	ifp->udpsocket = NULL;
+	ifp->udpdispatch = NULL;
+	
+	ifp->tcpsocket = NULL;
+	ifp->ntcptarget = ns_g_cpus;
+	ifp->ntcpcurrent = 0;
+
+	ns_interfacemgr_attach(mgr, &ifp->mgr);	
+	ISC_LIST_APPEND(mgr->interfaces, ifp, link);
+
+	ifp->references = 1;
+	ifp->magic = IFACE_MAGIC;
+	*ifpret = ifp;
+
+	return (DNS_R_SUCCESS);
+
+
+	isc_task_detach(&ifp->task);
+ task_create_failure:
+	isc_mutex_destroy(&ifp->lock);
+ lock_create_failure:
+	ifp->magic = 0;
+	isc_mem_put(mgr->mctx, ifp, sizeof(*ifp));
+
+	return (DNS_R_UNEXPECTED);
+}
+
+static isc_result_t
+ns_interface_listenudp(ns_interface_t *ifp) {
+	isc_result_t result;
+	
 	/*
 	 * Open a UDP socket.
 	 */
-	ifp->udpsocket = NULL;
-	result = isc_socket_create(mgr->socketmgr,
-				   isc_sockaddr_pf(addr),
+	result = isc_socket_create(ifp->mgr->socketmgr,
+				   isc_sockaddr_pf(&ifp->addr),
 				   isc_sockettype_udp,
 				   &ifp->udpsocket);
 	if (result != ISC_R_SUCCESS) {
@@ -148,8 +236,7 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
 	 * this UDP socket will be shared with the resolver, and if so, we
 	 * need to set the hashsize to be be something bigger than 17.
 	 */
-	ifp->udpdispatch = NULL;
-	result = dns_dispatch_create(mgr->mctx, ifp->udpsocket, ifp->task,
+	result = dns_dispatch_create(ifp->mgr->mctx, ifp->udpsocket, ifp->task,
 				     4096, 50, 50, 17, 19, NULL,
 				     &ifp->udpdispatch);
 	if (result != ISC_R_SUCCESS) {
@@ -158,22 +245,34 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
 				 isc_result_totext(result));
 		goto udp_dispatch_failure;
 	}
-	result = ns_clientmgr_addtodispatch(mgr->clientmgr, ns_g_cpus,
-					    ifp->udpdispatch);
+
+	result = ns_clientmgr_addtodispatch(ifp->mgr->clientmgr, ns_g_cpus, ifp);
 	if (result != ISC_R_SUCCESS) {
 		UNEXPECTED_ERROR(__FILE__, __LINE__,
 				 "UDP ns_clientmgr_addtodispatch(): %s",
 				 isc_result_totext(result));
 		goto addtodispatch_failure;
 	}
+	return (ISC_R_SUCCESS);
+
+ addtodispatch_failure:
+	dns_dispatch_detach(&ifp->udpdispatch);
+ udp_dispatch_failure:
+ udp_bind_failure:
+	isc_socket_detach(&ifp->udpsocket);
+ udp_socket_failure:
+	return (result);
+}
+
+static isc_result_t
+ns_interface_accepttcp(ns_interface_t *ifp) {
+	isc_result_t result;
 	
-	ifp->tcpsocket = NULL;
-	if (!udp_only) {
 	/*
 	 * Open a TCP socket.
 	 */
-		result = isc_socket_create(mgr->socketmgr,
-					   isc_sockaddr_pf(addr),
+	result = isc_socket_create(ifp->mgr->socketmgr,
+				   isc_sockaddr_pf(&ifp->addr),
 				   isc_sockettype_tcp,
 				   &ifp->tcpsocket);
 	if (result != ISC_R_SUCCESS) {
@@ -196,75 +295,112 @@ ns_interface_create(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
 				 isc_result_totext(result));
 		goto tcp_listen_failure;
 	}
-		result = ns_clientmgr_accepttcp(mgr->clientmgr, ifp->tcpsocket,
-						ns_g_cpus);
+	result = ns_clientmgr_accepttcp(ifp->mgr->clientmgr,
+					ifp->ntcptarget, ifp);
 	if (result != ISC_R_SUCCESS) {
 		UNEXPECTED_ERROR(__FILE__, __LINE__,
 				 "TCP ns_clientmgr_accepttcp(): %s",
 				 isc_result_totext(result));
 		goto accepttcp_failure;
 	}
-	}
-
-	ISC_LIST_APPEND(mgr->interfaces, ifp, link);
-
-	ifp->magic = IFACE_MAGIC;
-	*ifpret = ifp;
-
-	return (DNS_R_SUCCESS);
+	return (ISC_R_SUCCESS);
 
  accepttcp_failure:
  tcp_listen_failure:
  tcp_bind_failure:
 	isc_socket_detach(&ifp->tcpsocket);
  tcp_socket_failure:
+	return (DNS_R_SUCCESS);
+}
+
+static isc_result_t
+ns_interface_setup(ns_interfacemgr_t *mgr, isc_sockaddr_t *addr,
+		   ns_interface_t **ifpret)
+{
+	isc_result_t result;
+	ns_interface_t *ifp = NULL;
+	REQUIRE(ifpret != NULL && *ifpret == NULL);
+	
+	result = ns_interface_create(mgr, addr, &ifp);
+	if (result != DNS_R_SUCCESS)
+		return (result);
+
+	result = ns_interface_listenudp(ifp);
+	if (result != DNS_R_SUCCESS)
+		goto cleanup_interface;
+
+	result = ns_interface_accepttcp(ifp);
+	if (result != DNS_R_SUCCESS) {
 		/*
 		 * XXXRTH  We don't currently have a way to easily stop dispatch
 		 * service, so we return currently return DNS_R_SUCCESS (the UDP
 		 * stuff will work even if TCP creation failed).  This will be fixed
 		 * later.
 		 */
-	return (DNS_R_SUCCESS);
+		result = ISC_R_SUCCESS;
+	}
+	*ifpret = ifp;
+	return (ISC_R_SUCCESS);
 	
- addtodispatch_failure:
-	dns_dispatch_detach(&ifp->udpdispatch);
- udp_dispatch_failure:
- udp_bind_failure:
-	isc_socket_detach(&ifp->udpsocket);
- udp_socket_failure:
-	isc_task_detach(&ifp->task);
- task_create_failure:
-	ifp->magic = 0;
-	isc_mem_put(mgr->mctx, ifp, sizeof(*ifp));
-
-	return (DNS_R_UNEXPECTED);
+ cleanup_interface:
+	ISC_LIST_UNLINK(ifp->mgr->interfaces, ifp, link);	
+	ns_interface_detach(&ifp);
+	return (result);
 }
 
-static isc_result_t
-ns_interface_destroy(ns_interface_t **ifpret) {
-        ns_interface_t *ifp;	
-	REQUIRE(ifpret != NULL);
-	REQUIRE(VALID_IFACE(*ifpret));
-	ifp = *ifpret;
-
-	ISC_LIST_UNLINK(ifp->mgr->interfaces, ifp, link);
+static void
+ns_interface_destroy(ns_interface_t *ifp) {
+	isc_mem_t *mctx = ifp->mgr->mctx;
+	REQUIRE(NS_INTERFACE_VALID(ifp));
 
+	if (ifp->udpdispatch != NULL)
 		dns_dispatch_detach(&ifp->udpdispatch);
+	if (ifp->udpsocket != NULL) {
 		isc_socket_cancel(ifp->udpsocket, NULL, ISC_SOCKCANCEL_ALL);
 		isc_socket_detach(&ifp->udpsocket);
-
+	}
 	if (ifp->tcpsocket != NULL) {
 		isc_socket_cancel(ifp->tcpsocket, NULL, ISC_SOCKCANCEL_ALL);
 		isc_socket_detach(&ifp->tcpsocket);
 	}
 
 	isc_task_detach(&ifp->task);
+	isc_mutex_destroy(&ifp->lock);
+
+	ns_interfacemgr_detach(&ifp->mgr);
 	
 	ifp->magic = 0;
-	isc_mem_put(ifp->mgr->mctx, ifp, sizeof(*ifp));
+	isc_mem_put(mctx, ifp, sizeof(*ifp));
+}
 
-	*ifpret = NULL;
-	return (DNS_R_SUCCESS);
+void
+ns_interface_attach(ns_interface_t *source,
+		    ns_interface_t **target)
+{
+	REQUIRE(NS_INTERFACE_VALID(source));
+	LOCK(&source->lock);
+	INSIST(source->references > 0);
+	source->references++;
+	UNLOCK(&source->lock);
+	*target = source;
+}
+
+void 
+ns_interface_detach(ns_interface_t **targetp)
+{
+	isc_result_t need_destroy = ISC_FALSE;
+	ns_interface_t *target = *targetp;
+	REQUIRE(target != NULL);
+	REQUIRE(NS_INTERFACE_VALID(target));
+	LOCK(&target->lock);
+	REQUIRE(target->references > 0);
+	target->references--;
+	if (target->references == 0)
+		need_destroy = ISC_TRUE;
+	UNLOCK(&target->lock);
+	if (need_destroy)
+		ns_interface_destroy(target);
+	*targetp = NULL;
 }
 
 /*
@@ -289,17 +425,17 @@ static void
 purge_old_interfaces(ns_interfacemgr_t *mgr) {
         ns_interface_t *ifp, *next;
         for (ifp = ISC_LIST_HEAD(mgr->interfaces); ifp != NULL; ifp = next) {
-		INSIST(VALID_IFACE(ifp));
+		INSIST(NS_INTERFACE_VALID(ifp));
 		next = ISC_LIST_NEXT(ifp, link);
 		if (ifp->generation != mgr->generation) {
-			isc_result_t result = ns_interface_destroy(&ifp);
-			RUNTIME_CHECK(result == DNS_R_SUCCESS);
+			ISC_LIST_UNLINK(ifp->mgr->interfaces, ifp, link);
+			ns_interface_detach(&ifp);
 		}
 	}
 }
 
 static void
-do_ipv4(ns_interfacemgr_t *mgr, isc_boolean_t udp_only) {
+do_ipv4(ns_interfacemgr_t *mgr) {
 	isc_interfaceiter_t *iter = NULL;
 	isc_result_t result;
 
@@ -346,14 +482,15 @@ do_ipv4(ns_interfacemgr_t *mgr, isc_boolean_t udp_only) {
 				      interface.name, addrstr,
 				      ntohs(listen_addr.type.sin.sin_port));
 		
-			result = ns_interface_create(mgr, &listen_addr,
-						     udp_only, &ifp);
+			result = ns_interface_setup(mgr, &listen_addr, &ifp);
 			if (result != DNS_R_SUCCESS) {
 				UNEXPECTED_ERROR(__FILE__, __LINE__,
-					 "listening on IPv4 interface %s"
-					 " failed; interface ignored",
+					 "creating IPv4 interface %s "
+					 "failed; interface ignored",
 					 interface.name);
+				/* Continue. */
 			}
+
 		}
 		result = isc_interfaceiter_next(iter);
 	}
@@ -383,31 +520,30 @@ do_ipv6(ns_interfacemgr_t *mgr) {
 			      NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
 			      "listening on IPv6 interfaces, port %u",
 			      ns_g_port);
-		result = ns_interface_create(mgr, &listen_addr, ISC_FALSE,
-					     &ifp);
-		if (result != DNS_R_SUCCESS)
+		result = ns_interface_setup(mgr, &listen_addr, &ifp);
+		if (result != DNS_R_SUCCESS) {
 			UNEXPECTED_ERROR(__FILE__, __LINE__,
 				 "listening on IPv6 interfaces failed");
+			/* Continue. */
+		}
 	}
 }
 
 void
 ns_interfacemgr_scan(ns_interfacemgr_t *mgr) {
-	isc_boolean_t udp_only = ISC_FALSE;
 
-	REQUIRE(VALID_IFMGR(mgr));
+	REQUIRE(NS_INTERFACEMGR_VALID(mgr));
 
 	mgr->generation++;	/* Increment the generation count. */ 
 
 	if (isc_net_probeipv6() == ISC_R_SUCCESS) {
 		do_ipv6(mgr);
-		udp_only = ISC_TRUE;
 	} else
 		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
 			      NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
 			      "no IPv6 interfaces found");
 	if (isc_net_probeipv4() == ISC_R_SUCCESS)
-		do_ipv4(mgr, udp_only);
+		do_ipv4(mgr);
 	else
 		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_NETWORK,
 			      NS_LOGMODULE_INTERFACEMGR, ISC_LOG_INFO,
@@ -430,26 +566,3 @@ ns_interfacemgr_scan(ns_interfacemgr_t *mgr) {
 		 */
 	}
 }
-
-void
-ns_interfacemgr_destroy(ns_interfacemgr_t **mgrp)
-{
-	ns_interfacemgr_t *mgr;
-
-	REQUIRE(mgrp != NULL);
-	mgr = *mgrp;
-	REQUIRE(VALID_IFMGR(mgr));
-
-	/*
-	 * Destroy all interfaces.  By incrementing the generation count,
-	 * we make purge_old_interfaces() consider all interfaces "old"
-	 * and destroy all of them.
-	 */
-	mgr->generation++;
-	purge_old_interfaces(mgr);
-	INSIST(ISC_LIST_EMPTY(mgr->interfaces));
-
-	mgr->magic = 0;
-	isc_mem_put(mgr->mctx, mgr, sizeof *mgr);
-	*mgrp = NULL;
-}

bin/named/query.c

@@ -1693,10 +1693,23 @@ query_recurse(ns_client_t *client, dns_rdatatype_t qtype, dns_name_t *qdomain,
 	dns_rdataset_t *rdataset, *sigrdataset;
 	unsigned int options = 0;
 
+	/*
+	 * Set up a new client object to handle incoming queries while
+	 * this one is being resolved.
+	 */
+	result = ns_client_replace(client, &ns_g_server->recursionquota);
+	if (result != ISC_R_SUCCESS) {
+		/* Most likely the quota was full. */
+		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_CLIENT,
+			      NS_LOGMODULE_QUERY, ISC_LOG_WARNING,
+			      "no more recursive clients: %s",
+			      isc_result_totext(result));
+		return (result); 
+	}
+
 	/*
 	 * Invoke the resolver.
 	 */
-
 	REQUIRE(nameservers->type == dns_rdatatype_ns);
 	REQUIRE(client->query.fetch == NULL);
 

bin/named/server.c

@@ -646,11 +646,14 @@ ns_server_create(isc_mem_t *mctx, ns_server_t **serverp) {
 	server->recursionacl = NULL;
 	server->transferacl = NULL;
 
+	/* XXX these values are for debugging only */
+	RUNTIME_CHECK(isc_quota_init(&server->xfroutquota, 1) == ISC_R_SUCCESS); 
+	RUNTIME_CHECK(isc_quota_init(&server->tcpquota, 3) == ISC_R_SUCCESS);
+	RUNTIME_CHECK(isc_quota_init(&server->recursionquota, 1) == ISC_R_SUCCESS);
+	
 	/* Initialize server data structures. */
 	ISC_LIST_INIT(server->viewlist);
-	result = isc_rwlock_init(&server->viewlock, 0, 0);
-	if (result != ISC_R_SUCCESS)
-		return (result);
+	RUNTIME_CHECK(isc_rwlock_init(&server->viewlock, 0, 0) == ISC_R_SUCCESS);
 
 	server->interfacemgr = NULL;
 	result = ns_interfacemgr_create(ns_g_mctx, ns_g_taskmgr,
@@ -658,8 +661,9 @@ ns_server_create(isc_mem_t *mctx, ns_server_t **serverp) {
 					&server->interfacemgr);
 	if (result != ISC_R_SUCCESS) {
 		UNEXPECTED_ERROR(__FILE__, __LINE__,
-				 "ns_interfacemgr_create() failed: %s\n",
+				 "ns_interfacemgr_create() failed: %s",
 				 isc_result_totext(result));
+		/* XXX cleanup */
 		return (ISC_R_UNEXPECTED);
 	}
 
@@ -677,7 +681,8 @@ ns_server_destroy(ns_server_t **serverp) {
 	 * The interface manager owns tasks, so we have to destroy it before
 	 * we destroy the task manager.
 	 */
-	ns_interfacemgr_destroy(&server->interfacemgr);
+	ns_interfacemgr_shutdown(server->interfacemgr);
+	ns_interfacemgr_detach(&server->interfacemgr);	
 
 	INSIST(ISC_LIST_EMPTY(server->viewlist));
 	isc_rwlock_destroy(&server->viewlock);
@@ -689,6 +694,10 @@ ns_server_destroy(ns_server_t **serverp) {
 	if (server->transferacl != NULL)
 		dns_acl_detach(&server->transferacl);
 
+	isc_quota_destroy(&server->recursionquota);
+	isc_quota_destroy(&server->tcpquota);
+	isc_quota_destroy(&server->xfroutquota);
+	
 	server->magic = 0;
 	isc_mem_put(server->mctx, server, sizeof(*server));
 }

bin/named/xfrout.c

@@ -15,7 +15,7 @@
  * SOFTWARE.
  */
 
- /* $Id: xfrout.c,v 1.33 1999/12/23 00:08:23 explorer Exp $ */
+ /* $Id: xfrout.c,v 1.34 2000/01/11 21:18:21 gson Exp $ */
 
 #include <config.h>
 
@@ -805,6 +805,17 @@ ns_xfr_start(ns_client_t *client, dns_rdatatype_t reqtype)
 	
 	isc_log_write(XFROUT_DEBUG_LOGARGS(6), "got %s request", mnemonic);
 
+	/*
+	 * Apply quotas.
+	 */
+	result = ns_client_getquota(client, &ns_g_server->xfroutquota);
+	if (result != DNS_R_SUCCESS) {
+		isc_log_write(XFROUT_COMMON_LOGARGS, ISC_LOG_WARNING,
+			      "zone transfer request denied: %s",
+			      isc_result_totext(result));
+		goto failure;
+	}
+
 	/*
 	 * Interpret the question section.
 	 */