From f34cc4f62cd6730fc315ace47b9ae90a82a07ec0 Mon Sep 17 00:00:00 2001

From: Mark Andrews <marka@isc.org>

Date: Thu, 4 Sep 2014 10:37:45 +1000

Subject: [PATCH] 3939. [func] Improve UPDATE forwarding performance by

 allowing TCP connections to be shared. [RT #37039]

(cherry picked from commit 74717eef53ba5d6aefc80eb262bbb090ff4bb3b5)

---

 lib/dns/dispatch.c             | 112 ++++++++++++++++++++++++++++++++-

 lib/dns/include/dns/dispatch.h |  15 +++++

 lib/dns/request.c              |  46 ++++++++++----

 lib/dns/win32/libdns.def       |   2 +

 4 files changed, 159 insertions(+), 16 deletions(-)

diff --git a/lib/dns/dispatch.c b/lib/dns/dispatch.c

index c93651d..ee82241 100644

--- a/lib/dns/dispatch.c

+++ b/lib/dns/dispatch.c

@@ -228,6 +228,7 @@ struct dns_dispatch {

 	isc_socket_t	       *socket;		/*%< isc socket attached to */

 	isc_sockaddr_t		local;		/*%< local address */

 	in_port_t		localport;	/*%< local UDP port */

+	isc_sockaddr_t		peer;		/*%< peer address (TCP) */

 	unsigned int		maxrequests;	/*%< max requests */

 	isc_event_t	       *ctlevent;

@@ -2327,7 +2328,6 @@ dns_dispatchmgr_destroy(dns_dispatchmgr_t **mgrp) {

 	LOCK(&mgr->lock);

 	mgr->state |= MGR_SHUTTINGDOWN;

-

 	killit = destroy_mgr_ok(mgr);

 	UNLOCK(&mgr->lock);

@@ -2601,6 +2601,7 @@ dispatch_allocate(dns_dispatchmgr_t *mgr, unsigned int maxrequests,

 	disp->refcount = 1;

 	disp->recv_pending = 0;

 	memset(&disp->local, 0, sizeof(disp->local));

+	memset(&disp->peer, 0, sizeof(disp->peer));

 	disp->localport = 0;

 	disp->shutting_down = 0;

 	disp->shutdown_out = 0;

@@ -2702,6 +2703,23 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 		       unsigned int buckets, unsigned int increment,

 		       unsigned int attributes, dns_dispatch_t **dispp)

 {

+

+	attributes |= DNS_DISPATCHATTR_PRIVATE;  /* XXXMLG */

+

+	return (dns_dispatch_createtcp2(mgr, sock, taskmgr, NULL, NULL,

+					buffersize, maxbuffers, maxrequests,

+					buckets, increment, attributes,

+					dispp));

+}

+

+isc_result_t

+dns_dispatch_createtcp2(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

+		        isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr,

+			isc_sockaddr_t *destaddr, unsigned int buffersize,

+		        unsigned int maxbuffers, unsigned int maxrequests,

+		        unsigned int buckets, unsigned int increment,

+		        unsigned int attributes, dns_dispatch_t **dispp)

+{

 	isc_result_t result;

 	dns_dispatch_t *disp;

@@ -2713,7 +2731,8 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 	REQUIRE((attributes & DNS_DISPATCHATTR_TCP) != 0);

 	REQUIRE((attributes & DNS_DISPATCHATTR_UDP) == 0);

-	attributes |= DNS_DISPATCHATTR_PRIVATE;  /* XXXMLG */

+	if (destaddr == NULL)

+		attributes |= DNS_DISPATCHATTR_PRIVATE;  /* XXXMLG */

 	LOCK(&mgr->lock);

@@ -2760,6 +2779,23 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 	disp->attributes = attributes;

+	if (localaddr == NULL) {

+		if (destaddr != NULL) {

+			switch (isc_sockaddr_pf(destaddr)) {

+			case AF_INET:

+				isc_sockaddr_any(&disp->local);

+				break;

+			case AF_INET6:

+				isc_sockaddr_any6(&disp->local);

+				break;

+			}

+		}

+	} else

+		disp->local = *localaddr;

+

+	if (destaddr != NULL)

+		disp->peer = *destaddr;

+

 	/*

 	 * Append it to the dispatcher list.

 	 */

@@ -2768,7 +2804,6 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 	mgr_log(mgr, LVL(90), "created TCP dispatcher %p", disp);

 	dispatch_log(disp, LVL(90), "created task %p", disp->task[0]);

-

 	*dispp = disp;

 	return (ISC_R_SUCCESS);

@@ -2788,6 +2823,77 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 	return (result);

 }

+isc_result_t

+dns_dispatch_gettcp(dns_dispatchmgr_t *mgr, isc_sockaddr_t *destaddr,

+		    isc_sockaddr_t *localaddr, dns_dispatch_t **dispp)

+{

+#ifdef BIND9

+	dns_dispatch_t *disp;

+	isc_result_t result;

+	isc_sockaddr_t peeraddr;

+	isc_sockaddr_t sockname;

+	isc_sockaddr_t any;

+	unsigned int attributes, mask;

+	isc_boolean_t match = ISC_FALSE;

+

+	REQUIRE(VALID_DISPATCHMGR(mgr));

+	REQUIRE(destaddr != NULL);

+	REQUIRE(dispp != NULL && *dispp == NULL);

+

+	attributes = DNS_DISPATCHATTR_TCP;

+	mask = DNS_DISPATCHATTR_TCP | DNS_DISPATCHATTR_PRIVATE |

+	       DNS_DISPATCHATTR_EXCLUSIVE;

+

+	if (localaddr == NULL) {

+		switch (isc_sockaddr_pf(destaddr)) {

+		case AF_INET:

+			isc_sockaddr_any(&any;;

+			break;

+		case AF_INET6:

+			isc_sockaddr_any6(&any;;

+			break;

+		default:

+			return (ISC_R_NOTFOUND);

+		}

+		localaddr = &any;

+	}

+

+	LOCK(&mgr->lock);

+	disp = ISC_LIST_HEAD(mgr->list);

+	while (disp != NULL && !match) {

+		LOCK(&disp->lock);

+		if ((disp->shutting_down == 0) &&

+		    ATTRMATCH(disp->attributes, attributes, mask) &&

+		    (localaddr == NULL ||

+		     isc_sockaddr_eqaddr(localaddr, &disp->local))) {

+			result = isc_socket_getsockname(disp->socket,

+							&sockname);

+			if (result == ISC_R_SUCCESS)

+				result = isc_socket_getpeername(disp->socket,

+								&peeraddr);

+			if (result == ISC_R_SUCCESS &&

+			    isc_sockaddr_equal(destaddr, &peeraddr) &&

+			    isc_sockaddr_eqaddr(localaddr, &sockname)) {

+				/* attach */

+				disp->refcount++;

+				*dispp = disp;

+				match = ISC_TRUE;

+			}

+		}

+		UNLOCK(&disp->lock);

+		disp = ISC_LIST_NEXT(disp, link);

+	}

+	UNLOCK(&mgr->lock);

+	return (match ? ISC_R_SUCCESS : ISC_R_NOTFOUND);

+#else

+	UNUSED(mgr);

+	UNUSED(destaddr);

+	UNUSED(localaddr);

+	UNUSED(dispp);

+	return ISC_R_NOTIMPLEMENTED;

+#endif

+}

+

 isc_result_t

 dns_dispatch_getudp_dup(dns_dispatchmgr_t *mgr, isc_socketmgr_t *sockmgr,

 		    isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr,

diff --git a/lib/dns/include/dns/dispatch.h b/lib/dns/include/dns/dispatch.h

index 1235f7c..be9cd66 100644

--- a/lib/dns/include/dns/dispatch.h

+++ b/lib/dns/include/dns/dispatch.h

@@ -298,6 +298,13 @@ dns_dispatch_createtcp(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

 		       unsigned int maxbuffers, unsigned int maxrequests,

 		       unsigned int buckets, unsigned int increment,

 		       unsigned int attributes, dns_dispatch_t **dispp);

+isc_result_t

+dns_dispatch_createtcp2(dns_dispatchmgr_t *mgr, isc_socket_t *sock,

+                        isc_taskmgr_t *taskmgr, isc_sockaddr_t *localaddr,

+                        isc_sockaddr_t *destaddr, unsigned int buffersize,

+                        unsigned int maxbuffers, unsigned int maxrequests,

+                        unsigned int buckets, unsigned int increment,

+                        unsigned int attributes, dns_dispatch_t **dispp);

 /*%<

  * Create a new dns_dispatch and attach it to the provided isc_socket_t.

  *

@@ -369,6 +376,14 @@ dns_dispatch_starttcp(dns_dispatch_t *disp);

  *\li	'disp' is valid.

  */

+isc_result_t

+dns_dispatch_gettcp(dns_dispatchmgr_t *mgr, isc_sockaddr_t *destaddr,

+                    isc_sockaddr_t *localaddr, dns_dispatch_t **dispp);

+/*

+ * Attempt to connect to a existing TCP connection.

+ */

+

+

 isc_result_t

 dns_dispatch_addresponse2(dns_dispatch_t *disp, isc_sockaddr_t *dest,

 			  isc_task_t *task, isc_taskaction_t action, void *arg,

diff --git a/lib/dns/request.c b/lib/dns/request.c

index 5c76f9a..9fb6f44 100644

--- a/lib/dns/request.c

+++ b/lib/dns/request.c

@@ -510,7 +510,8 @@ isblackholed(dns_dispatchmgr_t *dispatchmgr, isc_sockaddr_t *destaddr) {

 static isc_result_t

 create_tcp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,

-		    isc_sockaddr_t *destaddr, dns_dispatch_t **dispatchp)

+		    isc_sockaddr_t *destaddr, isc_boolean_t *connected,

+		    dns_dispatch_t **dispatchp)

 {

 	isc_result_t result;

 	isc_socket_t *socket = NULL;

@@ -518,6 +519,20 @@ create_tcp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,

 	unsigned int attrs;

 	isc_sockaddr_t bind_any;

+	*connected = ISC_FALSE;

+#ifdef BIND9

+	result = dns_dispatch_gettcp(requestmgr->dispatchmgr, destaddr,

+				     srcaddr, dispatchp);

+	if (result == ISC_R_SUCCESS) {

+		*connected = ISC_TRUE;

+		char peer[ISC_SOCKADDR_FORMATSIZE];

+		isc_sockaddr_format(destaddr, peer, sizeof(peer));

+		req_log(ISC_LOG_DEBUG(1), "attached to existing TCP "

+			"connection to %s", peer);

+		return (result);

+	}

+#endif

+

 	result = isc_socket_create(requestmgr->socketmgr,

 				   isc_sockaddr_pf(destaddr),

 				   isc_sockettype_tcp, &socket);

@@ -538,16 +553,16 @@ create_tcp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,

 #endif

 	attrs = 0;

 	attrs |= DNS_DISPATCHATTR_TCP;

-	attrs |= DNS_DISPATCHATTR_PRIVATE;

 	if (isc_sockaddr_pf(destaddr) == AF_INET)

 		attrs |= DNS_DISPATCHATTR_IPV4;

 	else

 		attrs |= DNS_DISPATCHATTR_IPV6;

 	attrs |= DNS_DISPATCHATTR_MAKEQUERY;

-	result = dns_dispatch_createtcp(requestmgr->dispatchmgr,

-					socket, requestmgr->taskmgr,

-					4096, 2, 1, 1, 3, attrs,

-					dispatchp);

+	result = dns_dispatch_createtcp2(requestmgr->dispatchmgr,

+					 socket, requestmgr->taskmgr,

+					 srcaddr, destaddr,

+					 4096, 32768, 32768, 16411, 16433,

+					 attrs, dispatchp);

 cleanup:

 	isc_socket_detach(&socket);

 	return (result);

@@ -609,12 +624,15 @@ find_udp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,

 static isc_result_t

 get_dispatch(isc_boolean_t tcp, dns_requestmgr_t *requestmgr,

 	     isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,

+	     isc_boolean_t *connected,

 	     dns_dispatch_t **dispatchp)

 {

 	isc_result_t result;

+

 	if (tcp)

 		result = create_tcp_dispatch(requestmgr, srcaddr,

-					     destaddr, dispatchp);

+					     destaddr, connected,

+					     dispatchp);

 	else

 		result = find_udp_dispatch(requestmgr, srcaddr,

 					   destaddr, dispatchp);

@@ -686,6 +704,7 @@ dns_request_createraw3(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,

 	dns_messageid_t	id;

 	isc_boolean_t tcp = ISC_FALSE;

 	isc_region_t r;

+	isc_boolean_t connected = ISC_FALSE;

 	REQUIRE(VALID_REQUESTMGR(requestmgr));

 	REQUIRE(msgbuf != NULL);

@@ -747,7 +766,7 @@ dns_request_createraw3(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,

 		tcp = ISC_TRUE;

 	result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,

-			      &request->dispatch);

+			      &connected, &request->dispatch);

 	if (result != ISC_R_SUCCESS)

 		goto cleanup;

@@ -794,14 +813,14 @@ dns_request_createraw3(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,

 		goto unlink;

 	request->destaddr = *destaddr;

-	if (tcp) {

+	if (tcp && !connected) {

 		result = isc_socket_connect(socket, destaddr, task,

 					    req_connected, request);

 		if (result != ISC_R_SUCCESS)

 			goto unlink;

 		request->flags |= DNS_REQUEST_F_CONNECTING|DNS_REQUEST_F_TCP;

 	} else {

-		result = req_send(request, task, destaddr);

+		result = req_send(request, task, connected ? NULL : destaddr);

 		if (result != ISC_R_SUCCESS)

 			goto unlink;

 	}

@@ -886,6 +905,7 @@ dns_request_createvia3(dns_requestmgr_t *requestmgr, dns_message_t *message,

 	dns_messageid_t	id;

 	isc_boolean_t tcp;

 	isc_boolean_t setkey = ISC_TRUE;

+	isc_boolean_t connected = ISC_FALSE;

 	REQUIRE(VALID_REQUESTMGR(requestmgr));

 	REQUIRE(message != NULL);

@@ -944,7 +964,7 @@ dns_request_createvia3(dns_requestmgr_t *requestmgr, dns_message_t *message,

  use_tcp:

 	tcp = ISC_TF((options & DNS_REQUESTOPT_TCP) != 0);

 	result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,

-			      &request->dispatch);

+			      &connected, &request->dispatch);

 	if (result != ISC_R_SUCCESS)

 		goto cleanup;

@@ -1000,14 +1020,14 @@ dns_request_createvia3(dns_requestmgr_t *requestmgr, dns_message_t *message,

 		goto unlink;

 	request->destaddr = *destaddr;

-	if (tcp) {

+	if (tcp && !connected) {

 		result = isc_socket_connect(socket, destaddr, task,

 					    req_connected, request);

 		if (result != ISC_R_SUCCESS)

 			goto unlink;

 		request->flags |= DNS_REQUEST_F_CONNECTING|DNS_REQUEST_F_TCP;

 	} else {

-		result = req_send(request, task, destaddr);

+		result = req_send(request, task, connected ? NULL : destaddr);

 		if (result != ISC_R_SUCCESS)

 			goto unlink;

 	}

diff --git a/lib/dns/win32/libdns.def b/lib/dns/win32/libdns.def

index 5e20491..9aebe16 100644

--- a/lib/dns/win32/libdns.def

+++ b/lib/dns/win32/libdns.def

@@ -176,9 +176,11 @@ dns_dispatch_attach

 dns_dispatch_cancel

 dns_dispatch_changeattributes

 dns_dispatch_createtcp

+dns_dispatch_createtcp2

 dns_dispatch_detach

 dns_dispatch_getlocaladdress

 dns_dispatch_getsocket

+dns_dispatch_gettcp

 dns_dispatch_getudp

 dns_dispatch_getudp_dup

 dns_dispatch_importrecv

-- 

2.20.1