Merge branch '2137-so_reuseport-doesn-t-distribute-udp-queries-to-multiple-netmgr-workers-on-macos' into 'main'

Distribute queries among threads even on platforms without SO_REUSEPORT_LB

Closes #2137

See merge request isc-projects/bind9!4459

CHANGES

@@ -1,3 +1,7 @@
+5545.	[func]		Restore reading of incoming queries by multiple netmgr
+			threads on platforms other than Linux and FreeBSD 12.
+			[GL #2137]
+
 5544.	[func]		Restore the default value of nocookie-udp-size to 4096.
 			[GL #2250]
 

doc/notes/notes-current.rst

@@ -19,11 +19,7 @@ Security Fixes
 Known Issues
 ~~~~~~~~~~~~
 
-- The ``named`` daemon uses load-balanced sockets to increase performance by
-  distributing the incoming queries among multiple threads.  Currently, the only
-  operating systems that support load-balanced sockets are Linux and FreeBSD 12,
-  thus both UDP and TCP performance is limited to a single-thread on systems
-  without load-balancing socket support. [GL #2137]
+- None.
 
 New Features
 ~~~~~~~~~~~~
@@ -70,3 +66,10 @@ Bug Fixes
 
 - Building with native PKCS#11 support for AEP Keyper has been broken
   since BIND 9.17.4. This has been fixed. [GL #2315]
+
+- The ``named`` daemon uses load-balanced sockets to increase performance by
+  distributing the incoming queries among multiple threads.  Currently, the only
+  operating systems that support load-balanced sockets are Linux and FreeBSD 12,
+  thus both UDP and TCP performance was limited to a single-thread on systems
+  without load-balancing socket support. This has been fixed on all platforms
+  except Windows. [GL #2137]

lib/isc/netmgr/netmgr-int.h

@@ -52,6 +52,10 @@
 #define ISC_NETMGR_RECVBUF_SIZE (65536)
 #endif
 
+#if defined(SO_REUSEPORT_LB) || (defined(SO_REUSEPORT) && defined(__linux__))
+#define HAVE_REUSEPORT_LB 1
+#endif
+
 /*
  * Define NETMGR_TRACE to activate tracing of handles and sockets.
  * This will impair performance but enables us to quickly determine,

lib/isc/netmgr/netmgr.c

@@ -169,22 +169,6 @@ isc__nm_in_netthread(void) {
 	return (isc__nm_tid_v >= 0);
 }
 
-static bool
-isc__nm_test_lb_socket(sa_family_t sa_family, int protocol) {
-	isc_result_t result;
-	uv_os_sock_t fd = -1;
-
-	result = isc__nm_socket(sa_family, protocol, 0, &fd);
-	REQUIRE(result == ISC_R_SUCCESS);
-
-	result = isc__nm_socket_reuse_lb(fd);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
-
-	isc__nm_closesocket(fd);
-
-	return (result == ISC_R_SUCCESS);
-}
-
 #ifdef WIN32
 static void
 isc__nm_winsock_initialize(void) {
@@ -231,14 +215,6 @@ isc_nm_start(isc_mem_t *mctx, uint32_t workers) {
 
 	isc__nm_tls_initialize();
 
-	if (!isc__nm_test_lb_socket(AF_INET, SOCK_DGRAM) ||
-	    !isc__nm_test_lb_socket(AF_INET, SOCK_STREAM) ||
-	    !isc__nm_test_lb_socket(AF_INET6, SOCK_DGRAM) ||
-	    !isc__nm_test_lb_socket(AF_INET6, SOCK_STREAM))
-	{
-		workers = 1;
-	}
-
 	mgr = isc_mem_get(mctx, sizeof(*mgr));
 	*mgr = (isc_nm_t){ .nworkers = workers };
 
@@ -2307,6 +2283,10 @@ isc__nm_socket_dontfrag(uv_os_sock_t fd, sa_family_t sa_family) {
 #define TIMEOUT_TYPE	unsigned int
 #define TIMEOUT_DIV	1
 #define TIMEOUT_OPTNAME TCP_USER_TIMEOUT
+#elif defined(TCP_KEEPINIT)
+#define TIMEOUT_TYPE	int
+#define TIMEOUT_DIV	1000
+#define TIMEOUT_OPTNAME TCP_KEEPINIT
 #endif
 
 isc_result_t

lib/isc/netmgr/tcp.c

@@ -378,27 +378,27 @@ isc_nm_tcpconnect(isc_nm_t *mgr, isc_nmiface_t *local, isc_nmiface_t *peer,
 	return (result);
 }
 
-static isc_result_t
-isc__nm_tcp_lb_socket(sa_family_t sa_family, uv_os_sock_t *sockp) {
+static uv_os_sock_t
+isc__nm_tcp_lb_socket(sa_family_t sa_family) {
 	isc_result_t result;
 	uv_os_sock_t sock;
 
 	result = isc__nm_socket(sa_family, SOCK_STREAM, 0, &sock);
-	REQUIRE(result == ISC_R_SUCCESS);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
 	(void)isc__nm_socket_incoming_cpu(sock);
 
 	/* FIXME: set mss */
 
 	result = isc__nm_socket_reuse(sock);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
+#if HAVE_SO_REUSEPORT_LB
 	result = isc__nm_socket_reuse_lb(sock);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
+#endif
 
-	*sockp = sock;
-
-	return (result);
+	return (sock);
 }
 
 isc_result_t
@@ -410,6 +410,7 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 	isc_nmsocket_t *sock = NULL;
 	sa_family_t sa_family = iface->addr.type.sa.sa_family;
 	size_t children_size = 0;
+	uv_os_sock_t fd = -1;
 
 	REQUIRE(VALID_NM(mgr));
 
@@ -417,7 +418,11 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 	isc__nmsocket_init(sock, mgr, isc_nm_tcplistener, iface);
 
 	sock->rchildren = 0;
+#if defined(WIN32)
+	sock->nchildren = 1;
+#else
 	sock->nchildren = mgr->nworkers;
+#endif
 	children_size = sock->nchildren * sizeof(sock->children[0]);
 	sock->children = isc_mem_get(mgr->mctx, children_size);
 	memset(sock->children, 0, children_size);
@@ -426,6 +431,10 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 	sock->tid = isc_random_uniform(mgr->nworkers);
 	sock->fd = -1;
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	fd = isc__nm_tcp_lb_socket(sa_family);
+#endif
+
 	for (size_t i = 0; i < mgr->nworkers; i++) {
 		isc__netievent_tcplisten_t *ievent = NULL;
 		isc_nmsocket_t *csock = &sock->children[i];
@@ -444,9 +453,11 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 		csock->pquota = quota;
 		isc_quota_cb_init(&csock->quotacb, quota_accept_cb, csock);
 
-		result = isc__nm_tcp_lb_socket(sa_family, &csock->fd);
-		REQUIRE(result == ISC_R_SUCCESS ||
-			result == ISC_R_NOTIMPLEMENTED);
+#if HAVE_SO_REUSEPORT_LB || defined(WIN32)
+		csock->fd = isc__nm_tcp_lb_socket(sa_family);
+#else
+		csock->fd = dup(fd);
+#endif
 		REQUIRE(csock->fd >= 0);
 
 		ievent = isc__nm_get_netievent_tcplisten(mgr, csock);
@@ -454,6 +465,10 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 				       (isc__netievent_t *)ievent);
 	}
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	isc__nm_closesocket(fd);
+#endif
+
 	LOCK(&sock->lock);
 	while (sock->rchildren != mgr->nworkers) {
 		WAIT(&sock->cond, &sock->lock);
@@ -479,11 +494,12 @@ isc_nm_listentcp(isc_nm_t *mgr, isc_nmiface_t *iface,
 void
 isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	isc__netievent_tcplisten_t *ievent = (isc__netievent_tcplisten_t *)ev0;
-	isc_nmiface_t *iface;
+	isc_nmiface_t *iface = NULL;
 	sa_family_t sa_family;
 	int r;
 	int flags = 0;
 	isc_nmsocket_t *sock = NULL;
+	isc_result_t result;
 
 	REQUIRE(VALID_NMSOCK(ievent->sock));
 	REQUIRE(ievent->sock->tid == isc_nm_tid());
@@ -502,14 +518,18 @@ isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	r = uv_tcp_init(&worker->loop, &sock->uv_handle.tcp);
 	RUNTIME_CHECK(r == 0);
+
 	uv_handle_set_data(&sock->uv_handle.handle, sock);
 	/* This keeps the socket alive after everything else is gone */
 	isc__nmsocket_attach(sock, &(isc_nmsocket_t *){ NULL });
 
 	r = uv_timer_init(&worker->loop, &sock->timer);
 	RUNTIME_CHECK(r == 0);
+
 	uv_handle_set_data((uv_handle_t *)&sock->timer, sock);
 
+	LOCK(&sock->parent->lock);
+
 	r = uv_tcp_open(&sock->uv_handle.tcp, sock->fd);
 	if (r < 0) {
 		isc__nm_closesocket(sock->fd);
@@ -522,12 +542,29 @@ isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 		flags = UV_TCP_IPV6ONLY;
 	}
 
+#if HAVE_SO_REUSEPORT_LB || defined(WIN32)
 	r = isc_uv_tcp_freebind(&sock->uv_handle.tcp,
 				&sock->iface->addr.type.sa, flags);
-	if (r < 0 && r != UV_EINVAL) {
+	if (r < 0) {
 		isc__nm_incstats(sock->mgr, sock->statsindex[STATID_BINDFAIL]);
 		goto failure;
 	}
+#else
+	if (sock->parent->fd == -1) {
+		r = isc_uv_tcp_freebind(&sock->uv_handle.tcp,
+					&sock->iface->addr.type.sa, flags);
+		if (r < 0) {
+			isc__nm_incstats(sock->mgr,
+					 sock->statsindex[STATID_BINDFAIL]);
+			goto failure;
+		}
+		sock->parent->uv_handle.tcp.flags = sock->uv_handle.tcp.flags;
+		sock->parent->fd = sock->fd;
+	} else {
+		/* The socket is already bound, just copy the flags */
+		sock->uv_handle.tcp.flags = sock->parent->uv_handle.tcp.flags;
+	}
+#endif
 
 	/*
 	 * The callback will run in the same thread uv_listen() was called
@@ -535,7 +572,7 @@ isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	 */
 	r = uv_listen((uv_stream_t *)&sock->uv_handle.tcp, sock->backlog,
 		      tcp_connection_cb);
-	if (r < 0) {
+	if (r != 0) {
 		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
 			      ISC_LOGMODULE_NETMGR, ISC_LOG_ERROR,
 			      "uv_listen failed: %s",
@@ -546,27 +583,15 @@ isc__nm_async_tcplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	atomic_store(&sock->listening, true);
 
-	LOCK(&sock->parent->lock);
-	sock->parent->rchildren += 1;
-	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = ISC_R_SUCCESS;
-	}
-	SIGNAL(&sock->parent->cond);
-	if (!atomic_load(&sock->parent->active)) {
-		WAIT(&sock->parent->scond, &sock->parent->lock);
-	}
-	INSIST(atomic_load(&sock->parent->active));
-	UNLOCK(&sock->parent->lock);
-
-	return;
-
 failure:
-	sock->pquota = NULL;
+	result = isc__nm_uverr2result(r);
+	if (result != ISC_R_SUCCESS) {
+		sock->pquota = NULL;
+	}
 
-	LOCK(&sock->parent->lock);
 	sock->parent->rchildren += 1;
 	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = isc__nm_uverr2result(r);
+		sock->parent->result = result;
 	}
 	SIGNAL(&sock->parent->cond);
 	if (!atomic_load(&sock->parent->active)) {
@@ -926,7 +951,7 @@ isc__nm_tcp_resumeread(isc_nmhandle_t *handle) {
 static void
 read_cb(uv_stream_t *stream, ssize_t nread, const uv_buf_t *buf) {
 	isc_nmsocket_t *sock = uv_handle_get_data((uv_handle_t *)stream);
-	isc__nm_uvreq_t *req;
+	isc__nm_uvreq_t *req = NULL;
 
 	REQUIRE(VALID_NMSOCK(sock));
 	REQUIRE(sock->tid == isc_nm_tid());
@@ -1027,7 +1052,7 @@ accept_connection(isc_nmsocket_t *ssock, isc_quota_t *quota) {
 	isc_result_t result;
 	struct sockaddr_storage ss;
 	isc_sockaddr_t local;
-	isc_nmhandle_t *handle;
+	isc_nmhandle_t *handle = NULL;
 
 	REQUIRE(VALID_NMSOCK(ssock));
 	REQUIRE(ssock->tid == isc_nm_tid());

lib/isc/netmgr/tcpdns.c

@@ -421,27 +421,27 @@ isc_nm_tcpdnsconnect(isc_nm_t *mgr, isc_nmiface_t *local, isc_nmiface_t *peer,
 	return (result);
 }
 
-static isc_result_t
-isc__nm_tcpdns_lb_socket(sa_family_t sa_family, uv_os_sock_t *sockp) {
+static uv_os_sock_t
+isc__nm_tcpdns_lb_socket(sa_family_t sa_family) {
 	isc_result_t result;
 	uv_os_sock_t sock;
 
 	result = isc__nm_socket(sa_family, SOCK_STREAM, 0, &sock);
-	REQUIRE(result == ISC_R_SUCCESS);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
 	(void)isc__nm_socket_incoming_cpu(sock);
 
 	/* FIXME: set mss */
 
 	result = isc__nm_socket_reuse(sock);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
+#if HAVE_SO_REUSEPORT_LB
 	result = isc__nm_socket_reuse_lb(sock);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
+#endif
 
-	*sockp = sock;
-
-	return (result);
+	return (sock);
 }
 
 isc_result_t
@@ -454,6 +454,7 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface,
 	isc_nmsocket_t *sock = NULL;
 	sa_family_t sa_family = iface->addr.type.sa.sa_family;
 	size_t children_size = 0;
+	uv_os_sock_t fd = -1;
 
 	REQUIRE(VALID_NM(mgr));
 
@@ -461,7 +462,11 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface,
 	isc__nmsocket_init(sock, mgr, isc_nm_tcpdnslistener, iface);
 
 	sock->rchildren = 0;
+#if defined(WIN32)
+	sock->nchildren = 1;
+#else
 	sock->nchildren = mgr->nworkers;
+#endif
 	children_size = sock->nchildren * sizeof(sock->children[0]);
 	sock->children = isc_mem_get(mgr->mctx, children_size);
 	memset(sock->children, 0, children_size);
@@ -470,6 +475,10 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface,
 	sock->tid = isc_random_uniform(mgr->nworkers);
 	sock->fd = -1;
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	fd = isc__nm_tcpdns_lb_socket(sa_family);
+#endif
+
 	for (size_t i = 0; i < mgr->nworkers; i++) {
 		isc__netievent_tcpdnslisten_t *ievent = NULL;
 		isc_nmsocket_t *csock = &sock->children[i];
@@ -490,9 +499,11 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface,
 		csock->pquota = quota;
 		isc_quota_cb_init(&csock->quotacb, quota_accept_cb, csock);
 
-		result = isc__nm_tcpdns_lb_socket(sa_family, &csock->fd);
-		REQUIRE(result == ISC_R_SUCCESS ||
-			result == ISC_R_NOTIMPLEMENTED);
+#if HAVE_SO_REUSEPORT_LB || defined(WIN32)
+		csock->fd = isc__nm_tcpdns_lb_socket(sa_family);
+#else
+		csock->fd = dup(fd);
+#endif
 		REQUIRE(csock->fd >= 0);
 
 		ievent = isc__nm_get_netievent_tcpdnslisten(mgr, csock);
@@ -500,6 +511,10 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface,
 				       (isc__netievent_t *)ievent);
 	}
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	isc__nm_closesocket(fd);
+#endif
+
 	LOCK(&sock->lock);
 	while (sock->rchildren != mgr->nworkers) {
 		WAIT(&sock->cond, &sock->lock);
@@ -526,11 +541,12 @@ void
 isc__nm_async_tcpdnslisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	isc__netievent_tcpdnslisten_t *ievent =
 		(isc__netievent_tcpdnslisten_t *)ev0;
-	isc_nmiface_t *iface;
+	isc_nmiface_t *iface = NULL;
 	sa_family_t sa_family;
 	int r;
 	int flags = 0;
 	isc_nmsocket_t *sock = NULL;
+	isc_result_t result = ISC_R_DEFAULT;
 
 	REQUIRE(VALID_NMSOCK(ievent->sock));
 	REQUIRE(ievent->sock->tid == isc_nm_tid());
@@ -557,6 +573,8 @@ isc__nm_async_tcpdnslisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	RUNTIME_CHECK(r == 0);
 	uv_handle_set_data((uv_handle_t *)&sock->timer, sock);
 
+	LOCK(&sock->parent->lock);
+
 	r = uv_tcp_open(&sock->uv_handle.tcp, sock->fd);
 	if (r < 0) {
 		isc__nm_closesocket(sock->fd);
@@ -569,12 +587,29 @@ isc__nm_async_tcpdnslisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 		flags = UV_TCP_IPV6ONLY;
 	}
 
+#if HAVE_SO_REUSEPORT_LB || defined(WIN32)
 	r = isc_uv_tcp_freebind(&sock->uv_handle.tcp,
 				&sock->iface->addr.type.sa, flags);
-	if (r < 0 && r != UV_EINVAL) {
+	if (r < 0) {
 		isc__nm_incstats(sock->mgr, sock->statsindex[STATID_BINDFAIL]);
 		goto failure;
 	}
+#else
+	if (sock->parent->fd == -1) {
+		r = isc_uv_tcp_freebind(&sock->uv_handle.tcp,
+					&sock->iface->addr.type.sa, flags);
+		if (r < 0) {
+			isc__nm_incstats(sock->mgr,
+					 sock->statsindex[STATID_BINDFAIL]);
+			goto failure;
+		}
+		sock->parent->uv_handle.tcp.flags = sock->uv_handle.tcp.flags;
+		sock->parent->fd = sock->fd;
+	} else {
+		/* The socket is already bound, just copy the flags */
+		sock->uv_handle.tcp.flags = sock->parent->uv_handle.tcp.flags;
+	}
+#endif
 
 	/*
 	 * The callback will run in the same thread uv_listen() was called
@@ -582,7 +617,7 @@ isc__nm_async_tcpdnslisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	 */
 	r = uv_listen((uv_stream_t *)&sock->uv_handle.tcp, sock->backlog,
 		      tcpdns_connection_cb);
-	if (r < 0) {
+	if (r != 0) {
 		isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
 			      ISC_LOGMODULE_NETMGR, ISC_LOG_ERROR,
 			      "uv_listen failed: %s",
@@ -593,27 +628,15 @@ isc__nm_async_tcpdnslisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	atomic_store(&sock->listening, true);
 
-	LOCK(&sock->parent->lock);
-	sock->parent->rchildren += 1;
-	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = ISC_R_SUCCESS;
-	}
-	SIGNAL(&sock->parent->cond);
-	if (!atomic_load(&sock->parent->active)) {
-		WAIT(&sock->parent->scond, &sock->parent->lock);
-	}
-	INSIST(atomic_load(&sock->parent->active));
-	UNLOCK(&sock->parent->lock);
-
-	return;
-
 failure:
-	sock->pquota = NULL;
+	result = isc__nm_uverr2result(r);
+	if (result != ISC_R_SUCCESS) {
+		sock->pquota = NULL;
+	}
 
-	LOCK(&sock->parent->lock);
 	sock->parent->rchildren += 1;
 	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = isc__nm_uverr2result(r);
+		sock->parent->result = result;
 	}
 	SIGNAL(&sock->parent->cond);
 	if (!atomic_load(&sock->parent->active)) {
@@ -921,7 +944,7 @@ isc__nm_async_tcpdnsread(isc__networker_t *worker, isc__netievent_t *ev0) {
 static isc_result_t
 processbuffer(isc_nmsocket_t *sock) {
 	size_t len;
-	isc__nm_uvreq_t *req;
+	isc__nm_uvreq_t *req = NULL;
 	isc_nmhandle_t *handle = NULL;
 
 	REQUIRE(VALID_NMSOCK(sock));
@@ -1049,14 +1072,15 @@ free:
 static void
 quota_accept_cb(isc_quota_t *quota, void *sock0) {
 	isc_nmsocket_t *sock = (isc_nmsocket_t *)sock0;
-	isc__netievent_tcpdnsaccept_t *ievent = NULL;
 
 	REQUIRE(VALID_NMSOCK(sock));
 
 	/*
 	 * Create a tcpdnsaccept event and pass it using the async channel.
 	 */
-	ievent = isc__nm_get_netievent_tcpdnsaccept(sock->mgr, sock, quota);
+
+	isc__netievent_tcpdnsaccept_t *ievent =
+		isc__nm_get_netievent_tcpdnsaccept(sock->mgr, sock, quota);
 	isc__nm_maybe_enqueue_ievent(&sock->mgr->workers[sock->tid],
 				     (isc__netievent_t *)ievent);
 }
@@ -1068,15 +1092,14 @@ void
 isc__nm_async_tcpdnsaccept(isc__networker_t *worker, isc__netievent_t *ev0) {
 	isc__netievent_tcpdnsaccept_t *ievent =
 		(isc__netievent_tcpdnsaccept_t *)ev0;
-	isc_nmsocket_t *sock = ievent->sock;
 	isc_result_t result;
 
 	UNUSED(worker);
 
-	REQUIRE(VALID_NMSOCK(sock));
-	REQUIRE(sock->tid == isc_nm_tid());
+	REQUIRE(VALID_NMSOCK(ievent->sock));
+	REQUIRE(ievent->sock->tid == isc_nm_tid());
 
-	result = accept_connection(sock, ievent->quota);
+	result = accept_connection(ievent->sock, ievent->quota);
 	if (result != ISC_R_SUCCESS && result != ISC_R_NOCONN) {
 		if ((result != ISC_R_QUOTA && result != ISC_R_SOFTQUOTA) ||
 		    can_log_tcpdns_quota())
@@ -1098,7 +1121,7 @@ accept_connection(isc_nmsocket_t *ssock, isc_quota_t *quota) {
 	struct sockaddr_storage peer_ss;
 	struct sockaddr_storage local_ss;
 	isc_sockaddr_t local;
-	isc_nmhandle_t *handle;
+	isc_nmhandle_t *handle = NULL;
 
 	REQUIRE(VALID_NMSOCK(ssock));
 	REQUIRE(ssock->tid == isc_nm_tid());

lib/isc/netmgr/udp.c

@@ -77,27 +77,26 @@ inactive(isc_nmsocket_t *sock) {
 		(sock->server != NULL && !isc__nmsocket_active(sock->server)));
 }
 
-static isc_result_t
-isc__nm_udp_lb_socket(sa_family_t sa_family, uv_os_sock_t *sockp) {
+static uv_os_sock_t
+isc__nm_udp_lb_socket(sa_family_t sa_family) {
 	isc_result_t result;
 	uv_os_sock_t sock;
 
 	result = isc__nm_socket(sa_family, SOCK_DGRAM, 0, &sock);
-	REQUIRE(result == ISC_R_SUCCESS);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
 	(void)isc__nm_socket_incoming_cpu(sock);
-
 	(void)isc__nm_socket_dontfrag(sock, sa_family);
 
 	result = isc__nm_socket_reuse(sock);
-	REQUIRE(result == ISC_R_SUCCESS);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
+#if HAVE_SO_REUSEPORT_LB
 	result = isc__nm_socket_reuse_lb(sock);
-	REQUIRE(result == ISC_R_SUCCESS || result == ISC_R_NOTIMPLEMENTED);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS);
+#endif
 
-	*sockp = sock;
-
-	return (result);
+	return (sock);
 }
 
 isc_result_t
@@ -107,6 +106,7 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 	isc_nmsocket_t *sock = NULL;
 	sa_family_t sa_family = iface->addr.type.sa.sa_family;
 	size_t children_size = 0;
+	uv_os_sock_t fd = -1;
 
 	REQUIRE(VALID_NM(mgr));
 
@@ -118,7 +118,12 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 	isc__nmsocket_init(sock, mgr, isc_nm_udplistener, iface);
 
 	sock->rchildren = 0;
+#if defined(WIN32)
+	sock->nchildren = 1;
+#else
 	sock->nchildren = mgr->nworkers;
+#endif
+
 	children_size = sock->nchildren * sizeof(sock->children[0]);
 	sock->children = isc_mem_get(mgr->mctx, children_size);
 	memset(sock->children, 0, children_size);
@@ -130,6 +135,10 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 	sock->tid = isc_random_uniform(mgr->nworkers);
 	sock->fd = -1;
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	fd = isc__nm_udp_lb_socket(sa_family);
+#endif
+
 	for (size_t i = 0; i < mgr->nworkers; i++) {
 		isc__netievent_udplisten_t *ievent = NULL;
 		isc_nmsocket_t *csock = &sock->children[i];
@@ -143,7 +152,11 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 		csock->extrahandlesize = sock->extrahandlesize;
 		csock->tid = i;
 
-		(void)isc__nm_udp_lb_socket(sa_family, &csock->fd);
+#if HAVE_SO_REUSEPORT_LB || defined(WIN32)
+		csock->fd = isc__nm_udp_lb_socket(sa_family);
+#else
+		csock->fd = dup(fd);
+#endif
 		REQUIRE(csock->fd >= 0);
 
 		ievent = isc__nm_get_netievent_udplisten(mgr, csock);
@@ -151,6 +164,10 @@ isc_nm_listenudp(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
 				       (isc__netievent_t *)ievent);
 	}
 
+#if !HAVE_SO_REUSEPORT_LB && !defined(WIN32)
+	isc__nm_closesocket(fd);
+#endif
+
 	LOCK(&sock->lock);
 	while (sock->rchildren != mgr->nworkers) {
 		WAIT(&sock->cond, &sock->lock);
@@ -205,11 +222,12 @@ udp_alloc_cb(uv_handle_t *handle, size_t size, uv_buf_t *buf) {
 void
 isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	isc__netievent_udplisten_t *ievent = (isc__netievent_udplisten_t *)ev0;
-	isc_nmiface_t *iface;
+	isc_nmiface_t *iface = NULL;
 	isc_nmsocket_t *sock = NULL;
 	int r, uv_bind_flags = 0;
 	int uv_init_flags = 0;
 	sa_family_t sa_family;
+	isc_result_t result = ISC_R_DEFAULT;
 
 	REQUIRE(VALID_NMSOCK(ievent->sock));
 	REQUIRE(ievent->sock->tid == isc_nm_tid());
@@ -237,6 +255,8 @@ isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 	RUNTIME_CHECK(r == 0);
 	uv_handle_set_data((uv_handle_t *)&sock->timer, sock);
 
+	LOCK(&sock->parent->lock);
+
 	r = uv_udp_open(&sock->uv_handle.udp, sock->fd);
 	if (r < 0) {
 		isc__nm_closesocket(sock->fd);
@@ -249,13 +269,33 @@ isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 		uv_bind_flags |= UV_UDP_IPV6ONLY;
 	}
 
+#if HAVE_SO_REUSEPORT_LB || WIN32
 	r = isc_uv_udp_freebind(&sock->uv_handle.udp,
 				&sock->parent->iface->addr.type.sa,
 				uv_bind_flags);
-	if (r < 0 && r != UV_EINVAL) {
+	if (r < 0) {
 		isc__nm_incstats(sock->mgr, sock->statsindex[STATID_BINDFAIL]);
 		goto failure;
 	}
+#else
+	if (sock->parent->fd == -1) {
+		/* This thread is first, bind the socket */
+		r = isc_uv_udp_freebind(&sock->uv_handle.udp,
+					&sock->parent->iface->addr.type.sa,
+					uv_bind_flags);
+		if (r < 0) {
+			isc__nm_incstats(sock->mgr,
+					 sock->statsindex[STATID_BINDFAIL]);
+			goto failure;
+		}
+		sock->parent->uv_handle.udp.flags = sock->uv_handle.udp.flags;
+		sock->parent->fd = sock->fd;
+	} else {
+		/* The socket is already bound, just copy the flags */
+		sock->uv_handle.udp.flags = sock->parent->uv_handle.udp.flags;
+	}
+#endif
+
 #ifdef ISC_RECV_BUFFER_SIZE
 	uv_recv_buffer_size(&sock->uv_handle.handle,
 			    &(int){ ISC_RECV_BUFFER_SIZE });
@@ -272,24 +312,11 @@ isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
 
 	atomic_store(&sock->listening, true);
 
-	LOCK(&sock->parent->lock);
-	sock->parent->rchildren += 1;
-	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = ISC_R_SUCCESS;
-	}
-	SIGNAL(&sock->parent->cond);
-	if (!atomic_load(&sock->parent->active)) {
-		WAIT(&sock->parent->scond, &sock->parent->lock);
-	}
-	INSIST(atomic_load(&sock->parent->active));
-	UNLOCK(&sock->parent->lock);
-
-	return;
 failure:
-	LOCK(&sock->parent->lock);
+	result = isc__nm_uverr2result(r);
 	sock->parent->rchildren += 1;
 	if (sock->parent->result == ISC_R_DEFAULT) {
-		sock->parent->result = isc__nm_uverr2result(r);
+		sock->parent->result = result;
 	}
 	SIGNAL(&sock->parent->cond);
 	if (!atomic_load(&sock->parent->active)) {
@@ -359,7 +386,7 @@ static void
 udp_recv_cb(uv_udp_t *handle, ssize_t nrecv, const uv_buf_t *buf,
 	    const struct sockaddr *addr, unsigned flags) {
 	isc_nmsocket_t *sock = uv_handle_get_data((uv_handle_t *)handle);
-	isc__nm_uvreq_t *req;
+	isc__nm_uvreq_t *req = NULL;
 	uint32_t maxudp;
 	bool free_buf;
 	isc_sockaddr_t sockaddr;
@@ -1224,7 +1251,7 @@ isc__nm_udp_cancelread(isc_nmhandle_t *handle) {
 void
 isc__nm_async_udpcancel(isc__networker_t *worker, isc__netievent_t *ev0) {
 	isc__netievent_udpcancel_t *ievent = (isc__netievent_udpcancel_t *)ev0;
-	isc_nmsocket_t *sock;
+	isc_nmsocket_t *sock = NULL;
 
 	UNUSED(worker);
 

lib/isc/netmgr/uverr2result.c

@@ -29,6 +29,8 @@ isc_result_t
 isc___nm_uverr2result(int uverr, bool dolog, const char *file,
 		      unsigned int line, const char *func) {
 	switch (uverr) {
+	case 0:
+		return (ISC_R_SUCCESS);
 	case UV_ENOTDIR:
 	case UV_ELOOP:
 	case UV_EINVAL: /* XXX sometimes this is not for files */

lib/isc/tests/tcp_quota_test.c

@@ -9,7 +9,7 @@
  * information regarding copyright ownership.
  */
 
-#if HAVE_CMOCKA && defined(__linux__)
+#if HAVE_CMOCKA
 #include <sched.h> /* IWYU pragma: keep */
 #include <setjmp.h>
 #include <stdarg.h>

lib/isc/tests/tcp_test.c

@@ -9,7 +9,7 @@
  * information regarding copyright ownership.
  */
 
-#if HAVE_CMOCKA && defined(__linux__)
+#if HAVE_CMOCKA
 #include <sched.h> /* IWYU pragma: keep */
 #include <setjmp.h>
 #include <stdarg.h>

lib/isc/tests/tcpdns_test.c

@@ -9,7 +9,7 @@
  * information regarding copyright ownership.
  */
 
-#if HAVE_CMOCKA && defined(__linux__)
+#if HAVE_CMOCKA
 #include <sched.h> /* IWYU pragma: keep */
 #include <setjmp.h>
 #include <stdarg.h>

lib/isc/tests/udp_test.c

@@ -9,7 +9,7 @@
  * information regarding copyright ownership.
  */
 
-#if HAVE_CMOCKA && defined(__linux__)
+#if HAVE_CMOCKA
 #include <sched.h> /* IWYU pragma: keep */
 #include <setjmp.h>
 #include <stdarg.h>